221 files changed, 188809 insertions, 0 deletions

diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
new file mode 100644
index 000000000..5646dc624
--- /dev/null
+++ b/drivers/tty/Kconfig
@@ -0,0 +1,417 @@
+# SPDX-License-Identifier: GPL-2.0
+config TTY
+	bool "Enable TTY" if EXPERT
+	default y
+	help
+	  Allows you to remove TTY support which can save space, and
+	  blocks features that require TTY from inclusion in the kernel.
+	  TTY is required for any text terminals or serial port
+	  communication. Most users should leave this enabled.
+
+if TTY
+
+config VT
+	bool "Virtual terminal" if EXPERT
+	select INPUT
+	default y if !UML
+	help
+	  If you say Y here, you will get support for terminal devices with
+	  display and keyboard devices. These are called "virtual" because you
+	  can run several virtual terminals (also called virtual consoles) on
+	  one physical terminal. This is rather useful, for example one
+	  virtual terminal can collect system messages and warnings, another
+	  one can be used for a text-mode user session, and a third could run
+	  an X session, all in parallel. Switching between virtual terminals
+	  is done with certain key combinations, usually Alt-<function key>.
+
+	  The setterm command ("man setterm") can be used to change the
+	  properties (such as colors or beeping) of a virtual terminal. The
+	  man page console_codes(4) ("man console_codes") contains the special
+	  character sequences that can be used to change those properties
+	  directly. The fonts used on virtual terminals can be changed with
+	  the setfont ("man setfont") command and the key bindings are defined
+	  with the loadkeys ("man loadkeys") command.
+
+	  You need at least one virtual terminal device in order to make use
+	  of your keyboard and monitor. Therefore, only people configuring an
+	  embedded system would want to say N here in order to save some
+	  memory; the only way to log into such a system is then via a serial
+	  or network connection.
+
+	  If unsure, say Y, or else you won't be able to do much with your new
+	  shiny Linux system :-)
+
+config CONSOLE_TRANSLATIONS
+	depends on VT
+	default y
+	bool "Enable character translations in console" if EXPERT
+	help
+	  This enables support for font mapping and Unicode translation
+	  on virtual consoles.
+
+config VT_CONSOLE
+	bool "Support for console on virtual terminal" if EXPERT
+	depends on VT
+	default y
+	help
+	  The system console is the device which receives all kernel messages
+	  and warnings and which allows logins in single user mode. If you
+	  answer Y here, a virtual terminal (the device used to interact with
+	  a physical terminal) can be used as system console. This is the most
+	  common mode of operations, so you should say Y here unless you want
+	  the kernel messages be output only to a serial port (in which case
+	  you should say Y to "Console on serial port", below).
+
+	  If you do say Y here, by default the currently visible virtual
+	  terminal (/dev/tty0) will be used as system console. You can change
+	  that with a kernel command line option such as "console=tty3" which
+	  would use the third virtual terminal as system console. (Try "man
+	  bootparam" or see the documentation of your boot loader (lilo or
+	  loadlin) about how to pass options to the kernel at boot time.)
+
+	  If unsure, say Y.
+
+config VT_CONSOLE_SLEEP
+	def_bool y
+	depends on VT_CONSOLE && PM_SLEEP
+
+config HW_CONSOLE
+	bool
+	depends on VT
+	default y
+
+config VT_HW_CONSOLE_BINDING
+	bool "Support for binding and unbinding console drivers"
+	depends on HW_CONSOLE
+	help
+	  The virtual terminal is the device that interacts with the physical
+	  terminal through console drivers. On these systems, at least one
+	  console driver is loaded. In other configurations, additional console
+	  drivers may be enabled, such as the framebuffer console. If more than
+	  1 console driver is enabled, setting this to 'y' will allow you to
+	  select the console driver that will serve as the backend for the
+	  virtual terminals.
+
+	  See <file:Documentation/driver-api/console.rst> for more
+	  information. For framebuffer console users, please refer to
+	  <file:Documentation/fb/fbcon.rst>.
+
+config UNIX98_PTYS
+	bool "Unix98 PTY support" if EXPERT
+	default y
+	help
+	  A pseudo terminal (PTY) is a software device consisting of two
+	  halves: a master and a slave. The slave device behaves identical to
+	  a physical terminal; the master device is used by a process to
+	  read data from and write data to the slave, thereby emulating a
+	  terminal. Typical programs for the master side are telnet servers
+	  and xterms.
+
+	  Linux has traditionally used the BSD-like names /dev/ptyxx for
+	  masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
+	  has a number of problems. The GNU C library glibc 2.1 and later,
+	  however, supports the Unix98 naming standard: in order to acquire a
+	  pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
+	  terminal is then made available to the process and the pseudo
+	  terminal slave can be accessed as /dev/pts/<number>. What was
+	  traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
+
+	  All modern Linux systems use the Unix98 ptys.  Say Y unless
+	  you're on an embedded system and want to conserve memory.
+
+config LEGACY_PTYS
+	bool "Legacy (BSD) PTY support"
+	default y
+	help
+	  A pseudo terminal (PTY) is a software device consisting of two
+	  halves: a master and a slave. The slave device behaves identical to
+	  a physical terminal; the master device is used by a process to
+	  read data from and write data to the slave, thereby emulating a
+	  terminal. Typical programs for the master side are telnet servers
+	  and xterms.
+
+	  Linux has traditionally used the BSD-like names /dev/ptyxx
+	  for masters and /dev/ttyxx for slaves of pseudo
+	  terminals. This scheme has a number of problems, including
+	  security.  This option enables these legacy devices; on most
+	  systems, it is safe to say N.
+
+config LEGACY_PTY_COUNT
+	int "Maximum number of legacy PTY in use"
+	depends on LEGACY_PTYS
+	range 0 256
+	default "256"
+	help
+	  The maximum number of legacy PTYs that can be used at any one time.
+	  The default is 256, and should be more than enough.  Embedded
+	  systems may want to reduce this to save memory.
+
+	  When not in use, each legacy PTY occupies 12 bytes on 32-bit
+	  architectures and 24 bytes on 64-bit architectures.
+
+config LEGACY_TIOCSTI
+	bool "Allow legacy TIOCSTI usage"
+	default y
+	help
+	  Historically the kernel has allowed TIOCSTI, which will push
+	  characters into a controlling TTY. This continues to be used
+	  as a malicious privilege escalation mechanism, and provides no
+	  meaningful real-world utility any more. Its use is considered
+	  a dangerous legacy operation, and can be disabled on most
+	  systems.
+
+	  Say Y here only if you have confirmed that your system's
+	  userspace depends on this functionality to continue operating
+	  normally.
+
+	  Processes which run with CAP_SYS_ADMIN, such as BRLTTY, can
+	  use TIOCSTI even when this is set to N.
+
+	  This functionality can be changed at runtime with the
+	  dev.tty.legacy_tiocsti sysctl. This configuration option sets
+	  the default value of the sysctl.
+
+config LDISC_AUTOLOAD
+	bool "Automatically load TTY Line Disciplines"
+	default y
+	help
+	  Historically the kernel has always automatically loaded any
+	  line discipline that is in a kernel module when a user asks
+	  for it to be loaded with the TIOCSETD ioctl, or through other
+	  means.  This is not always the best thing to do on systems
+	  where you know you will not be using some of the more
+	  "ancient" line disciplines, so prevent the kernel from doing
+	  this unless the request is coming from a process with the
+	  CAP_SYS_MODULE permissions.
+
+	  Say 'Y' here if you trust your userspace users to do the right
+	  thing, or if you have only provided the line disciplines that
+	  you know you will be using, or if you wish to continue to use
+	  the traditional method of on-demand loading of these modules
+	  by any user.
+
+	  This functionality can be changed at runtime with the
+	  dev.tty.ldisc_autoload sysctl, this configuration option will
+	  only set the default value of this functionality.
+
+source "drivers/tty/serial/Kconfig"
+
+config SERIAL_NONSTANDARD
+	bool "Non-standard serial port support"
+	depends on HAS_IOMEM
+	help
+	  Say Y here if you have any non-standard serial boards -- boards
+	  which aren't supported using the standard "dumb" serial driver.
+	  This includes intelligent serial boards such as
+	  Digiboards, etc. These are usually used for systems that need many
+	  serial ports because they serve many terminals or dial-in
+	  connections.
+
+	  Note that the answer to this question won't directly affect the
+	  kernel: saying N will just cause the configurator to skip all
+	  the questions about non-standard serial boards.
+
+	  Most people can say N here.
+
+config MOXA_INTELLIO
+	tristate "Moxa Intellio support"
+	depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
+	select FW_LOADER
+	help
+	  Say Y here if you have a Moxa Intellio multiport serial card.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called moxa.
+
+config MOXA_SMARTIO
+	tristate "Moxa SmartIO support v. 2.0"
+	depends on SERIAL_NONSTANDARD && PCI
+	help
+	  Say Y here if you have a Moxa SmartIO multiport serial card and/or
+	  want to help develop a new version of this driver.
+
+	  This is upgraded (1.9.1) driver from original Moxa drivers with
+	  changes finally resulting in PCI probing.
+
+	  This driver can also be built as a module. The module will be called
+	  mxser. If you want to do that, say M here.
+
+config SYNCLINK_GT
+	tristate "SyncLink GT/AC support"
+	depends on SERIAL_NONSTANDARD && PCI
+	depends on BROKEN
+	help
+	  Support for SyncLink GT and SyncLink AC families of
+	  synchronous and asynchronous serial adapters
+	  manufactured by Microgate Systems, Ltd. (www.microgate.com)
+
+config N_HDLC
+	tristate "HDLC line discipline support"
+	depends on SERIAL_NONSTANDARD
+	help
+	  Allows synchronous HDLC communications with tty device drivers that
+	  support synchronous HDLC such as the Microgate SyncLink adapter.
+
+	  This driver can be built as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want).
+	  The module will be called n_hdlc. If you want to do that, say M
+	  here.
+
+config PPC_EPAPR_HV_BYTECHAN
+	bool "ePAPR hypervisor byte channel driver"
+	depends on PPC
+	select EPAPR_PARAVIRT
+	help
+	  This driver creates /dev entries for each ePAPR hypervisor byte
+	  channel, thereby allowing applications to communicate with byte
+	  channels as if they were serial ports.
+
+config PPC_EARLY_DEBUG_EHV_BC
+	bool "Early console (udbg) support for ePAPR hypervisors"
+	depends on PPC_EPAPR_HV_BYTECHAN=y
+	help
+	  Select this option to enable early console (a.k.a. "udbg") support
+	  via an ePAPR byte channel.  You also need to choose the byte channel
+	  handle below.
+
+config PPC_EARLY_DEBUG_EHV_BC_HANDLE
+	int "Byte channel handle for early console (udbg)"
+	depends on PPC_EARLY_DEBUG_EHV_BC
+	default 0
+	help
+	  If you want early console (udbg) output through a byte channel,
+	  specify the handle of the byte channel to use.
+
+	  For this to work, the byte channel driver must be compiled
+	  in-kernel, not as a module.
+
+	  Note that only one early console driver can be enabled, so don't
+	  enable any others if you enable this one.
+
+	  If the number you specify is not a valid byte channel handle, then
+	  there simply will be no early console output.  This is true also
+	  if you don't boot under a hypervisor at all.
+
+config GOLDFISH_TTY
+	tristate "Goldfish TTY Driver"
+	depends on GOLDFISH
+	select SERIAL_CORE
+	select SERIAL_CORE_CONSOLE
+	help
+	  Console and system TTY driver for the Goldfish virtual platform.
+
+config GOLDFISH_TTY_EARLY_CONSOLE
+	bool
+	default y if GOLDFISH_TTY=y
+	select SERIAL_EARLYCON
+
+config IPWIRELESS
+	tristate "IPWireless 3G UMTS PCMCIA card support"
+	depends on PCMCIA && NETDEVICES
+	select PPP
+	help
+	  This is a driver for 3G UMTS PCMCIA card from IPWireless company. In
+	  some countries (for example Czech Republic, T-Mobile ISP) this card
+	  is shipped for service called UMTS 4G.
+
+config N_GSM
+	tristate "GSM MUX line discipline support (EXPERIMENTAL)"
+	depends on NET
+	help
+	  This line discipline provides support for the GSM MUX protocol and
+	  presents the mux as a set of 61 individual tty devices.
+
+config NOZOMI
+	tristate "HSDPA Broadband Wireless Data Card - Globe Trotter"
+	depends on PCI
+	help
+	  If you have a HSDPA driver Broadband Wireless Data Card -
+	  Globe Trotter PCMCIA card, say Y here.
+
+	  To compile this driver as a module, choose M here, the module
+	  will be called nozomi.
+
+config MIPS_EJTAG_FDC_TTY
+	bool "MIPS EJTAG Fast Debug Channel TTY"
+	depends on MIPS_CDMM
+	help
+	  This enables a TTY and console on the MIPS EJTAG Fast Debug Channels,
+	  if they are present. This can be useful when working with an EJTAG
+	  probe which supports it, to get console output and a login prompt via
+	  EJTAG without needing to connect a serial cable.
+
+	  TTY devices are named e.g. ttyFDC3c2 (for FDC channel 2 of the FDC on
+	  CPU3).
+
+	  The console can be enabled with console=fdc1 (for FDC channel 1 on all
+	  CPUs). Do not use the console unless there is a debug probe attached
+	  to drain the FDC TX FIFO.
+
+	  If unsure, say N.
+
+config MIPS_EJTAG_FDC_EARLYCON
+	bool "Early FDC console"
+	depends on MIPS_EJTAG_FDC_TTY
+	help
+	  This registers a console on FDC channel 1 very early during boot (from
+	  MIPS arch code). This is useful for bring-up and debugging early boot
+	  issues.
+
+	  Do not enable unless there is a debug probe attached to drain the FDC
+	  TX FIFO.
+
+	  If unsure, say N.
+
+config MIPS_EJTAG_FDC_KGDB
+	bool "Use KGDB over an FDC channel"
+	depends on MIPS_EJTAG_FDC_TTY && KGDB
+	default y
+	help
+	  This enables the use of KGDB over an FDC channel, allowing KGDB to be
+	  used remotely or when a serial port isn't available.
+
+config MIPS_EJTAG_FDC_KGDB_CHAN
+	int "KGDB FDC channel"
+	depends on MIPS_EJTAG_FDC_KGDB
+	range 2 15
+	default 3
+	help
+	  FDC channel number to use for KGDB.
+
+config NULL_TTY
+	tristate "NULL TTY driver"
+	help
+	  Say Y here if you want a NULL TTY which simply discards messages.
+
+	  This is useful to allow userspace applications which expect a console
+	  device to work without modifications even when no console is
+	  available or desired.
+
+	  In order to use this driver, you should redirect the console to this
+	  TTY, or boot the kernel with console=ttynull.
+
+	  If unsure, say N.
+
+config VCC
+	tristate "Sun Virtual Console Concentrator"
+	depends on SUN_LDOMS
+	help
+	  Support for Sun logical domain consoles.
+
+source "drivers/tty/hvc/Kconfig"
+
+config RPMSG_TTY
+	tristate "RPMSG tty driver"
+	depends on RPMSG
+	help
+	  Say y here to export rpmsg endpoints as tty devices, usually found
+	  in /dev/ttyRPMSGx.
+	  This makes it possible for user-space programs to send and receive
+	  rpmsg messages as a standard tty protocol.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called rpmsg_tty.
+
+endif # TTY
+
+source "drivers/tty/serdev/Kconfig"
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
new file mode 100644
index 000000000..07aca5184
--- /dev/null
+++ b/drivers/tty/Makefile
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_TTY)		+= tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o \
+				   tty_buffer.o tty_port.o tty_mutex.o \
+				   tty_ldsem.o tty_baudrate.o tty_jobctrl.o \
+				   n_null.o
+obj-$(CONFIG_LEGACY_PTYS)	+= pty.o
+obj-$(CONFIG_UNIX98_PTYS)	+= pty.o
+obj-$(CONFIG_AUDIT)		+= tty_audit.o
+obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o
+obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
+obj-$(CONFIG_N_GSM)		+= n_gsm.o
+
+obj-y				+= vt/
+obj-$(CONFIG_HVC_DRIVER)	+= hvc/
+obj-y				+= serial/
+obj-$(CONFIG_SERIAL_DEV_BUS)	+= serdev/
+
+# tty drivers
+obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
+obj-$(CONFIG_MOXA_INTELLIO)	+= moxa.o
+obj-$(CONFIG_MOXA_SMARTIO)	+= mxser.o
+obj-$(CONFIG_NOZOMI)		+= nozomi.o
+obj-$(CONFIG_NULL_TTY)	        += ttynull.o
+obj-$(CONFIG_SYNCLINK_GT)	+= synclink_gt.o
+obj-$(CONFIG_PPC_EPAPR_HV_BYTECHAN) += ehv_bytechan.o
+obj-$(CONFIG_GOLDFISH_TTY)	+= goldfish.o
+obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o
+obj-$(CONFIG_VCC)		+= vcc.o
+obj-$(CONFIG_RPMSG_TTY)		+= rpmsg_tty.o
+
+obj-y += ipwireless/
diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
new file mode 100644
index 000000000..785558c65
--- /dev/null
+++ b/drivers/tty/amiserial.c
@@ -0,0 +1,1662 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Serial driver for the amiga builtin port.
+ *
+ * This code was created by taking serial.c version 4.30 from kernel
+ * release 2.3.22, replacing all hardware related stuff with the
+ * corresponding amiga hardware actions, and removing all irrelevant
+ * code. As a consequence, it uses many of the constants and names
+ * associated with the registers and bits of 16550 compatible UARTS -
+ * but only to keep track of status, etc in the state variables. It
+ * was done this was to make it easier to keep the code in line with
+ * (non hardware specific) changes to serial.c.
+ *
+ * The port is registered with the tty driver as minor device 64, and
+ * therefore other ports should only use 65 upwards.
+ *
+ * Richard Lucock 28/12/99
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 
+ * 		1998, 1999  Theodore Ts'o
+ *
+ */
+
+/* Set of debugging defines */
+
+#undef SERIAL_DEBUG_INTR
+#undef SERIAL_DEBUG_OPEN
+#undef SERIAL_DEBUG_FLOW
+#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+
+/*
+ * End of serial driver configuration section.
+ */
+
+#include <linux/bitops.h>
+#include <linux/circ_buf.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/ptrace.h>
+#include <linux/seq_file.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/serial_core.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/tty_flip.h>
+#include <linux/tty.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+#include <asm/irq.h>
+#include <asm/setup.h>
+
+struct serial_state {
+	struct tty_port		tport;
+	struct circ_buf		xmit;
+	struct async_icount	icount;
+
+	unsigned long		port;
+	int			baud_base;
+	int			custom_divisor;
+	int			read_status_mask;
+	int			ignore_status_mask;
+	int			timeout;
+	int			quot;
+	int			IER; 	/* Interrupt Enable Register */
+	int			MCR; 	/* Modem control register */
+	int			x_char;	/* xon/xoff character */
+};
+
+static struct tty_driver *serial_driver;
+
+/* number of characters left in xmit buffer before we ask for more */
+#define WAKEUP_CHARS 256
+
+#define XMIT_FIFO_SIZE 1
+
+static unsigned char current_ctl_bits;
+
+static void change_speed(struct tty_struct *tty, struct serial_state *info,
+			 const struct ktermios *old);
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
+
+
+static struct serial_state serial_state;
+
+/* some serial hardware definitions */
+#define SDR_OVRUN   (1<<15)
+#define SDR_RBF     (1<<14)
+#define SDR_TBE     (1<<13)
+#define SDR_TSRE    (1<<12)
+
+#define SERPER_PARENB    (1<<15)
+
+#define AC_SETCLR   (1<<15)
+#define AC_UARTBRK  (1<<11)
+
+#define SER_DTR     (1<<7)
+#define SER_RTS     (1<<6)
+#define SER_DCD     (1<<5)
+#define SER_CTS     (1<<4)
+#define SER_DSR     (1<<3)
+
+static __inline__ void rtsdtr_ctrl(int bits)
+{
+    ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_stop() and rs_start()
+ *
+ * This routines are called before setting or resetting tty->flow.stopped.
+ * They enable or disable transmitter interrupts, as necessary.
+ * ------------------------------------------------------------
+ */
+static void rs_stop(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (info->IER & UART_IER_THRI) {
+		info->IER &= ~UART_IER_THRI;
+		/* disable Tx interrupt and remove any pending interrupts */
+		amiga_custom.intena = IF_TBE;
+		mb();
+		amiga_custom.intreq = IF_TBE;
+		mb();
+	}
+	local_irq_restore(flags);
+}
+
+static void rs_start(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (info->xmit.head != info->xmit.tail
+	    && info->xmit.buf
+	    && !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		amiga_custom.intena = IF_SETCLR | IF_TBE;
+		mb();
+		/* set a pending Tx Interrupt, transmitter should restart now */
+		amiga_custom.intreq = IF_SETCLR | IF_TBE;
+		mb();
+	}
+	local_irq_restore(flags);
+}
+
+/*
+ * ----------------------------------------------------------------------
+ *
+ * Here start the interrupt handling routines.
+ *
+ * -----------------------------------------------------------------------
+ */
+
+static void receive_chars(struct serial_state *info)
+{
+        int status;
+	int serdatr;
+	unsigned char ch, flag;
+	struct	async_icount *icount;
+	int oe = 0;
+
+	icount = &info->icount;
+
+	status = UART_LSR_DR; /* We obviously have a character! */
+	serdatr = amiga_custom.serdatr;
+	mb();
+	amiga_custom.intreq = IF_RBF;
+	mb();
+
+	if((serdatr & 0x1ff) == 0)
+	    status |= UART_LSR_BI;
+	if(serdatr & SDR_OVRUN)
+	    status |= UART_LSR_OE;
+
+	ch = serdatr & 0xff;
+	icount->rx++;
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("DR%02x:%02x...", ch, status);
+#endif
+	flag = TTY_NORMAL;
+
+	/*
+	 * We don't handle parity or frame errors - but I have left
+	 * the code in, since I'm not sure that the errors can't be
+	 * detected.
+	 */
+
+	if (status & (UART_LSR_BI | UART_LSR_PE |
+		      UART_LSR_FE | UART_LSR_OE)) {
+	  /*
+	   * For statistics only
+	   */
+	  if (status & UART_LSR_BI) {
+	    status &= ~(UART_LSR_FE | UART_LSR_PE);
+	    icount->brk++;
+	  } else if (status & UART_LSR_PE)
+	    icount->parity++;
+	  else if (status & UART_LSR_FE)
+	    icount->frame++;
+	  if (status & UART_LSR_OE)
+	    icount->overrun++;
+
+	  /*
+	   * Now check to see if character should be
+	   * ignored, and mask off conditions which
+	   * should be ignored.
+	   */
+	  if (status & info->ignore_status_mask)
+	    goto out;
+
+	  status &= info->read_status_mask;
+
+	  if (status & (UART_LSR_BI)) {
+#ifdef SERIAL_DEBUG_INTR
+	    printk("handling break....");
+#endif
+	    flag = TTY_BREAK;
+	    if (info->tport.flags & ASYNC_SAK)
+	      do_SAK(info->tport.tty);
+	  } else if (status & UART_LSR_PE)
+	    flag = TTY_PARITY;
+	  else if (status & UART_LSR_FE)
+	    flag = TTY_FRAME;
+	  if (status & UART_LSR_OE) {
+	    /*
+	     * Overrun is special, since it's
+	     * reported immediately, and doesn't
+	     * affect the current character
+	     */
+	     oe = 1;
+	  }
+	}
+	tty_insert_flip_char(&info->tport, ch, flag);
+	if (oe == 1)
+		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
+	tty_flip_buffer_push(&info->tport);
+out:
+	return;
+}
+
+static void transmit_chars(struct serial_state *info)
+{
+	amiga_custom.intreq = IF_TBE;
+	mb();
+	if (info->x_char) {
+	        amiga_custom.serdat = info->x_char | 0x100;
+		mb();
+		info->icount.tx++;
+		info->x_char = 0;
+		return;
+	}
+	if (info->xmit.head == info->xmit.tail
+	    || info->tport.tty->flow.stopped
+	    || info->tport.tty->hw_stopped) {
+		info->IER &= ~UART_IER_THRI;
+	        amiga_custom.intena = IF_TBE;
+		mb();
+		return;
+	}
+
+	amiga_custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
+	mb();
+	info->xmit.tail = info->xmit.tail & (UART_XMIT_SIZE - 1);
+	info->icount.tx++;
+
+	if (CIRC_CNT(info->xmit.head,
+		     info->xmit.tail,
+		     UART_XMIT_SIZE) < WAKEUP_CHARS)
+		tty_wakeup(info->tport.tty);
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("THRE...");
+#endif
+	if (info->xmit.head == info->xmit.tail) {
+	        amiga_custom.intena = IF_TBE;
+		mb();
+		info->IER &= ~UART_IER_THRI;
+	}
+}
+
+static void check_modem_status(struct serial_state *info)
+{
+	struct tty_port *port = &info->tport;
+	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
+	unsigned char dstatus;
+	struct	async_icount *icount;
+
+	/* Determine bits that have changed */
+	dstatus = status ^ current_ctl_bits;
+	current_ctl_bits = status;
+
+	if (dstatus) {
+		icount = &info->icount;
+		/* update input line counters */
+		if (dstatus & SER_DSR)
+			icount->dsr++;
+		if (dstatus & SER_DCD) {
+			icount->dcd++;
+		}
+		if (dstatus & SER_CTS)
+			icount->cts++;
+		wake_up_interruptible(&port->delta_msr_wait);
+	}
+
+	if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
+#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
+		printk("ttyS%d CD now %s...", info->line,
+		       (!(status & SER_DCD)) ? "on" : "off");
+#endif
+		if (!(status & SER_DCD))
+			wake_up_interruptible(&port->open_wait);
+		else {
+#ifdef SERIAL_DEBUG_OPEN
+			printk("doing serial hangup...");
+#endif
+			if (port->tty)
+				tty_hangup(port->tty);
+		}
+	}
+	if (tty_port_cts_enabled(port)) {
+		if (port->tty->hw_stopped) {
+			if (!(status & SER_CTS)) {
+#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
+				printk("CTS tx start...");
+#endif
+				port->tty->hw_stopped = false;
+				info->IER |= UART_IER_THRI;
+				amiga_custom.intena = IF_SETCLR | IF_TBE;
+				mb();
+				/* set a pending Tx Interrupt, transmitter should restart now */
+				amiga_custom.intreq = IF_SETCLR | IF_TBE;
+				mb();
+				tty_wakeup(port->tty);
+				return;
+			}
+		} else {
+			if ((status & SER_CTS)) {
+#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
+				printk("CTS tx stop...");
+#endif
+				port->tty->hw_stopped = true;
+				info->IER &= ~UART_IER_THRI;
+				/* disable Tx interrupt and remove any pending interrupts */
+				amiga_custom.intena = IF_TBE;
+				mb();
+				amiga_custom.intreq = IF_TBE;
+				mb();
+			}
+		}
+	}
+}
+
+static irqreturn_t ser_vbl_int( int irq, void *data)
+{
+        /* vbl is just a periodic interrupt we tie into to update modem status */
+	struct serial_state *info = data;
+	/*
+	 * TBD - is it better to unregister from this interrupt or to
+	 * ignore it if MSI is clear ?
+	 */
+	if(info->IER & UART_IER_MSI)
+	  check_modem_status(info);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ser_rx_int(int irq, void *dev_id)
+{
+	struct serial_state *info = dev_id;
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("ser_rx_int...");
+#endif
+
+	if (!info->tport.tty)
+		return IRQ_NONE;
+
+	receive_chars(info);
+#ifdef SERIAL_DEBUG_INTR
+	printk("end.\n");
+#endif
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ser_tx_int(int irq, void *dev_id)
+{
+	struct serial_state *info = dev_id;
+
+	if (amiga_custom.serdatr & SDR_TBE) {
+#ifdef SERIAL_DEBUG_INTR
+	  printk("ser_tx_int...");
+#endif
+
+	  if (!info->tport.tty)
+		return IRQ_NONE;
+
+	  transmit_chars(info);
+#ifdef SERIAL_DEBUG_INTR
+	  printk("end.\n");
+#endif
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the serial interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+/*
+ * ---------------------------------------------------------------
+ * Low level utility subroutines for the serial driver:  routines to
+ * figure out the appropriate timeout for an interrupt chain, routines
+ * to initialize and startup a serial port, and routines to shutdown a
+ * serial port.  Useful stuff like that.
+ * ---------------------------------------------------------------
+ */
+
+static int startup(struct tty_struct *tty, struct serial_state *info)
+{
+	struct tty_port *port = &info->tport;
+	unsigned long flags;
+	int	retval=0;
+	unsigned long page;
+
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	local_irq_save(flags);
+
+	if (tty_port_initialized(port)) {
+		free_page(page);
+		goto errout;
+	}
+
+	if (info->xmit.buf)
+		free_page(page);
+	else
+		info->xmit.buf = (unsigned char *) page;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("starting up ttys%d ...", info->line);
+#endif
+
+	/* Clear anything in the input buffer */
+
+	amiga_custom.intreq = IF_RBF;
+	mb();
+
+	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
+	if (retval) {
+		if (capable(CAP_SYS_ADMIN)) {
+			set_bit(TTY_IO_ERROR, &tty->flags);
+			retval = 0;
+		}
+		goto errout;
+	}
+
+	/* enable both Rx and Tx interrupts */
+	amiga_custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
+	mb();
+	info->IER = UART_IER_MSI;
+
+	/* remember current state of the DCD and CTS bits */
+	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
+
+	info->MCR = 0;
+	if (C_BAUD(tty))
+	  info->MCR = SER_DTR | SER_RTS;
+	rtsdtr_ctrl(info->MCR);
+
+	clear_bit(TTY_IO_ERROR, &tty->flags);
+	info->xmit.head = info->xmit.tail = 0;
+
+	/*
+	 * and set the speed of the serial port
+	 */
+	change_speed(tty, info, NULL);
+
+	tty_port_set_initialized(port, true);
+	local_irq_restore(flags);
+	return 0;
+
+errout:
+	local_irq_restore(flags);
+	return retval;
+}
+
+/*
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.
+ */
+static void shutdown(struct tty_struct *tty, struct serial_state *info)
+{
+	unsigned long	flags;
+
+	if (!tty_port_initialized(&info->tport))
+		return;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("Shutting down serial port %d ....\n", info->line);
+#endif
+
+	local_irq_save(flags); /* Disable interrupts */
+
+	/*
+	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
+	 * here so the queue might never be waken up
+	 */
+	wake_up_interruptible(&info->tport.delta_msr_wait);
+
+	/*
+	 * Free the IRQ, if necessary
+	 */
+	free_irq(IRQ_AMIGA_VERTB, info);
+
+	free_page((unsigned long)info->xmit.buf);
+	info->xmit.buf = NULL;
+
+	info->IER = 0;
+	amiga_custom.intena = IF_RBF | IF_TBE;
+	mb();
+
+	/* disable break condition */
+	amiga_custom.adkcon = AC_UARTBRK;
+	mb();
+
+	if (C_HUPCL(tty))
+		info->MCR &= ~(SER_DTR|SER_RTS);
+	rtsdtr_ctrl(info->MCR);
+
+	set_bit(TTY_IO_ERROR, &tty->flags);
+
+	tty_port_set_initialized(&info->tport, false);
+	local_irq_restore(flags);
+}
+
+
+/*
+ * This routine is called to set the UART divisor registers to match
+ * the specified baud rate for a serial port.
+ */
+static void change_speed(struct tty_struct *tty, struct serial_state *info,
+			 const struct ktermios *old_termios)
+{
+	struct tty_port *port = &info->tport;
+	int	quot = 0, baud_base, baud;
+	unsigned cflag, cval = 0;
+	int	bits;
+	unsigned long	flags;
+
+	cflag = tty->termios.c_cflag;
+
+	/* Byte size is always 8 bits plus parity bit if requested */
+
+	cval = 3; bits = 10;
+	if (cflag & CSTOPB) {
+		cval |= 0x04;
+		bits++;
+	}
+	if (cflag & PARENB) {
+		cval |= UART_LCR_PARITY;
+		bits++;
+	}
+	if (!(cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	if (cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+
+	/* Determine divisor based on baud rate */
+	baud = tty_get_baud_rate(tty);
+	if (!baud)
+		baud = 9600;	/* B0 transition handled in rs_set_termios */
+	baud_base = info->baud_base;
+	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
+		quot = info->custom_divisor;
+	else {
+		if (baud == 134)
+			/* Special case since 134 is really 134.5 */
+			quot = (2*baud_base / 269);
+		else if (baud)
+			quot = baud_base / baud;
+	}
+	/* If the quotient is zero refuse the change */
+	if (!quot && old_termios) {
+		/* FIXME: Will need updating for new tty in the end */
+		tty->termios.c_cflag &= ~CBAUD;
+		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
+		baud = tty_get_baud_rate(tty);
+		if (!baud)
+			baud = 9600;
+		if (baud == 38400 &&
+		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
+			quot = info->custom_divisor;
+		else {
+			if (baud == 134)
+				/* Special case since 134 is really 134.5 */
+				quot = (2*baud_base / 269);
+			else if (baud)
+				quot = baud_base / baud;
+		}
+	}
+	/* As a last resort, if the quotient is zero, default to 9600 bps */
+	if (!quot)
+		quot = baud_base / 9600;
+	info->quot = quot;
+	info->timeout = (XMIT_FIFO_SIZE*HZ*bits*quot) / baud_base;
+	info->timeout += HZ/50;		/* Add .02 seconds of slop */
+
+	/* CTS flow control flag and modem status interrupts */
+	info->IER &= ~UART_IER_MSI;
+	if (port->flags & ASYNC_HARDPPS_CD)
+		info->IER |= UART_IER_MSI;
+	tty_port_set_cts_flow(port, cflag & CRTSCTS);
+	if (cflag & CRTSCTS)
+		info->IER |= UART_IER_MSI;
+	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
+	if (~cflag & CLOCAL)
+		info->IER |= UART_IER_MSI;
+	/* TBD:
+	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
+	 */
+
+	/*
+	 * Set up parity check flag
+	 */
+
+	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
+	if (I_INPCK(tty))
+		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (I_BRKINT(tty) || I_PARMRK(tty))
+		info->read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	info->ignore_status_mask = 0;
+	if (I_IGNPAR(tty))
+		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (I_IGNBRK(tty)) {
+		info->ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignore parity and break indicators, ignore 
+		 * overruns too.  (For real raw support).
+		 */
+		if (I_IGNPAR(tty))
+			info->ignore_status_mask |= UART_LSR_OE;
+	}
+	/*
+	 * !!! ignore all characters if CREAD is not set
+	 */
+	if ((cflag & CREAD) == 0)
+		info->ignore_status_mask |= UART_LSR_DR;
+	local_irq_save(flags);
+
+	{
+	  short serper;
+
+	/* Set up the baud rate */
+	  serper = quot - 1;
+
+	/* Enable or disable parity bit */
+
+	if(cval & UART_LCR_PARITY)
+	  serper |= (SERPER_PARENB);
+
+	amiga_custom.serper = serper;
+	mb();
+	}
+
+	local_irq_restore(flags);
+}
+
+static int rs_put_char(struct tty_struct *tty, u8 ch)
+{
+	struct serial_state *info;
+	unsigned long flags;
+
+	info = tty->driver_data;
+
+	if (!info->xmit.buf)
+		return 0;
+
+	local_irq_save(flags);
+	if (CIRC_SPACE(info->xmit.head,
+		       info->xmit.tail,
+		       UART_XMIT_SIZE) == 0) {
+		local_irq_restore(flags);
+		return 0;
+	}
+
+	info->xmit.buf[info->xmit.head++] = ch;
+	info->xmit.head &= UART_XMIT_SIZE - 1;
+	local_irq_restore(flags);
+	return 1;
+}
+
+static void rs_flush_chars(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	if (info->xmit.head == info->xmit.tail
+	    || tty->flow.stopped
+	    || tty->hw_stopped
+	    || !info->xmit.buf)
+		return;
+
+	local_irq_save(flags);
+	info->IER |= UART_IER_THRI;
+	amiga_custom.intena = IF_SETCLR | IF_TBE;
+	mb();
+	/* set a pending Tx Interrupt, transmitter should restart now */
+	amiga_custom.intreq = IF_SETCLR | IF_TBE;
+	mb();
+	local_irq_restore(flags);
+}
+
+static ssize_t rs_write(struct tty_struct * tty, const u8 *buf, size_t count)
+{
+	int	c, ret = 0;
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	if (!info->xmit.buf)
+		return 0;
+
+	local_irq_save(flags);
+	while (1) {
+		c = CIRC_SPACE_TO_END(info->xmit.head,
+				      info->xmit.tail,
+				      UART_XMIT_SIZE);
+		if (count < c)
+			c = count;
+		if (c <= 0) {
+			break;
+		}
+		memcpy(info->xmit.buf + info->xmit.head, buf, c);
+		info->xmit.head = (info->xmit.head + c) & (UART_XMIT_SIZE - 1);
+		buf += c;
+		count -= c;
+		ret += c;
+	}
+	local_irq_restore(flags);
+
+	if (info->xmit.head != info->xmit.tail
+	    && !tty->flow.stopped
+	    && !tty->hw_stopped
+	    && !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		local_irq_disable();
+		amiga_custom.intena = IF_SETCLR | IF_TBE;
+		mb();
+		/* set a pending Tx Interrupt, transmitter should restart now */
+		amiga_custom.intreq = IF_SETCLR | IF_TBE;
+		mb();
+		local_irq_restore(flags);
+	}
+	return ret;
+}
+
+static unsigned int rs_write_room(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	return CIRC_SPACE(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
+}
+
+static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	return CIRC_CNT(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
+}
+
+static void rs_flush_buffer(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	info->xmit.head = info->xmit.tail = 0;
+	local_irq_restore(flags);
+	tty_wakeup(tty);
+}
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ */
+static void rs_send_xchar(struct tty_struct *tty, char ch)
+{
+	struct serial_state *info = tty->driver_data;
+        unsigned long flags;
+
+	info->x_char = ch;
+	if (ch) {
+		/* Make sure transmit interrupts are on */
+
+	        /* Check this ! */
+	        local_irq_save(flags);
+		if(!(amiga_custom.intenar & IF_TBE)) {
+		    amiga_custom.intena = IF_SETCLR | IF_TBE;
+		    mb();
+		    /* set a pending Tx Interrupt, transmitter should restart now */
+		    amiga_custom.intreq = IF_SETCLR | IF_TBE;
+		    mb();
+		}
+		local_irq_restore(flags);
+
+		info->IER |= UART_IER_THRI;
+	}
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_throttle()
+ * 
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ * ------------------------------------------------------------
+ */
+static void rs_throttle(struct tty_struct * tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+#ifdef SERIAL_DEBUG_THROTTLE
+	printk("throttle %s ....\n", tty_name(tty));
+#endif
+
+	if (I_IXOFF(tty))
+		rs_send_xchar(tty, STOP_CHAR(tty));
+
+	if (C_CRTSCTS(tty))
+		info->MCR &= ~SER_RTS;
+
+	local_irq_save(flags);
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+}
+
+static void rs_unthrottle(struct tty_struct * tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+#ifdef SERIAL_DEBUG_THROTTLE
+	printk("unthrottle %s ....\n", tty_name(tty));
+#endif
+
+	if (I_IXOFF(tty)) {
+		if (info->x_char)
+			info->x_char = 0;
+		else
+			rs_send_xchar(tty, START_CHAR(tty));
+	}
+	if (C_CRTSCTS(tty))
+		info->MCR |= SER_RTS;
+	local_irq_save(flags);
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_ioctl() and friends
+ * ------------------------------------------------------------
+ */
+
+static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
+{
+	struct serial_state *state = tty->driver_data;
+	unsigned int close_delay, closing_wait;
+
+	tty_lock(tty);
+	close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
+	closing_wait = state->tport.closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = jiffies_to_msecs(closing_wait) / 10;
+
+	ss->line = tty->index;
+	ss->port = state->port;
+	ss->flags = state->tport.flags;
+	ss->xmit_fifo_size = XMIT_FIFO_SIZE;
+	ss->baud_base = state->baud_base;
+	ss->close_delay = close_delay;
+	ss->closing_wait = closing_wait;
+	ss->custom_divisor = state->custom_divisor;
+	tty_unlock(tty);
+	return 0;
+}
+
+static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
+{
+	struct serial_state *state = tty->driver_data;
+	struct tty_port *port = &state->tport;
+	bool change_spd;
+	int 			retval = 0;
+	unsigned int close_delay, closing_wait;
+
+	tty_lock(tty);
+	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
+		ss->custom_divisor != state->custom_divisor;
+	if (ss->irq || ss->port != state->port ||
+			ss->xmit_fifo_size != XMIT_FIFO_SIZE) {
+		tty_unlock(tty);
+		return -EINVAL;
+	}
+
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
+	closing_wait = ss->closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = msecs_to_jiffies(closing_wait * 10);
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		if ((ss->baud_base != state->baud_base) ||
+		    (close_delay != port->close_delay) ||
+		    (closing_wait != port->closing_wait) ||
+		    ((ss->flags & ~ASYNC_USR_MASK) !=
+		     (port->flags & ~ASYNC_USR_MASK))) {
+			tty_unlock(tty);
+			return -EPERM;
+		}
+		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
+			       (ss->flags & ASYNC_USR_MASK));
+		state->custom_divisor = ss->custom_divisor;
+		goto check_and_exit;
+	}
+
+	if (ss->baud_base < 9600) {
+		tty_unlock(tty);
+		return -EINVAL;
+	}
+
+	/*
+	 * OK, past this point, all the error checking has been done.
+	 * At this point, we start making changes.....
+	 */
+
+	state->baud_base = ss->baud_base;
+	port->flags = ((port->flags & ~ASYNC_FLAGS) |
+			(ss->flags & ASYNC_FLAGS));
+	state->custom_divisor = ss->custom_divisor;
+	port->close_delay = close_delay;
+	port->closing_wait = closing_wait;
+
+check_and_exit:
+	if (tty_port_initialized(port)) {
+		if (change_spd) {
+			/* warn about deprecation unless clearing */
+			if (ss->flags & ASYNC_SPD_MASK)
+				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
+			change_speed(tty, state, NULL);
+		}
+	} else
+		retval = startup(tty, state);
+	tty_unlock(tty);
+	return retval;
+}
+
+/*
+ * get_lsr_info - get line status register info
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ * 	    is emptied.  On bus types like RS485, the transmitter must
+ * 	    release the bus after transmitting. This must be done when
+ * 	    the transmit shift register is empty, not be done when the
+ * 	    transmit holding register is empty.  This functionality
+ * 	    allows an RS485 driver to be written in user space. 
+ */
+static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
+{
+	unsigned char status;
+	unsigned int result;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	status = amiga_custom.serdatr;
+	mb();
+	local_irq_restore(flags);
+	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+
+static int rs_tiocmget(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned char control, status;
+	unsigned long flags;
+
+	if (tty_io_error(tty))
+		return -EIO;
+
+	control = info->MCR;
+	local_irq_save(flags);
+	status = ciab.pra;
+	local_irq_restore(flags);
+	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
+		| ((control & SER_DTR) ? TIOCM_DTR : 0)
+		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
+		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
+		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
+}
+
+static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
+						unsigned int clear)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	if (tty_io_error(tty))
+		return -EIO;
+
+	local_irq_save(flags);
+	if (set & TIOCM_RTS)
+		info->MCR |= SER_RTS;
+	if (set & TIOCM_DTR)
+		info->MCR |= SER_DTR;
+	if (clear & TIOCM_RTS)
+		info->MCR &= ~SER_RTS;
+	if (clear & TIOCM_DTR)
+		info->MCR &= ~SER_DTR;
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+	return 0;
+}
+
+/*
+ * rs_break() --- routine which turns the break handling on or off
+ */
+static int rs_break(struct tty_struct *tty, int break_state)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (break_state == -1)
+	  amiga_custom.adkcon = AC_SETCLR | AC_UARTBRK;
+	else
+	  amiga_custom.adkcon = AC_UARTBRK;
+	mb();
+	local_irq_restore(flags);
+	return 0;
+}
+
+/*
+ * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
+ * Return: write counters to the user passed counter struct
+ * NB: both 1->0 and 0->1 transitions are counted except for
+ *     RI where only 0->1 is counted.
+ */
+static int rs_get_icount(struct tty_struct *tty,
+				struct serial_icounter_struct *icount)
+{
+	struct serial_state *info = tty->driver_data;
+	struct async_icount cnow;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	cnow = info->icount;
+	local_irq_restore(flags);
+	icount->cts = cnow.cts;
+	icount->dsr = cnow.dsr;
+	icount->rng = cnow.rng;
+	icount->dcd = cnow.dcd;
+	icount->rx = cnow.rx;
+	icount->tx = cnow.tx;
+	icount->frame = cnow.frame;
+	icount->overrun = cnow.overrun;
+	icount->parity = cnow.parity;
+	icount->brk = cnow.brk;
+	icount->buf_overrun = cnow.buf_overrun;
+
+	return 0;
+}
+
+static int rs_ioctl(struct tty_struct *tty,
+		    unsigned int cmd, unsigned long arg)
+{
+	struct serial_state *info = tty->driver_data;
+	struct async_icount cprev, cnow;	/* kernel counter temps */
+	void __user *argp = (void __user *)arg;
+	unsigned long flags;
+	DEFINE_WAIT(wait);
+	int ret;
+
+	if ((cmd != TIOCSERCONFIG) &&
+	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
+		if (tty_io_error(tty))
+		    return -EIO;
+	}
+
+	switch (cmd) {
+		case TIOCSERCONFIG:
+			return 0;
+
+		case TIOCSERGETLSR: /* Get line status register */
+			return get_lsr_info(info, argp);
+
+		/*
+		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
+		 * - mask passed in arg for lines of interest
+ 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
+		 * Caller should use TIOCGICOUNT to see which one it was
+		 */
+		case TIOCMIWAIT:
+			local_irq_save(flags);
+			/* note the counters on entry */
+			cprev = info->icount;
+			local_irq_restore(flags);
+			while (1) {
+				prepare_to_wait(&info->tport.delta_msr_wait,
+						&wait, TASK_INTERRUPTIBLE);
+				local_irq_save(flags);
+				cnow = info->icount; /* atomic copy */
+				local_irq_restore(flags);
+				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
+				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
+					ret = -EIO; /* no change => error */
+					break;
+				}
+				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
+				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
+					ret = 0;
+					break;
+				}
+				schedule();
+				/* see if a signal did it */
+				if (signal_pending(current)) {
+					ret = -ERESTARTSYS;
+					break;
+				}
+				cprev = cnow;
+			}
+			finish_wait(&info->tport.delta_msr_wait, &wait);
+			return ret;
+
+		default:
+			return -ENOIOCTLCMD;
+		}
+	return 0;
+}
+
+static void rs_set_termios(struct tty_struct *tty, const struct ktermios *old_termios)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+	unsigned int cflag = tty->termios.c_cflag;
+
+	change_speed(tty, info, old_termios);
+
+	/* Handle transition to B0 status */
+	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
+		info->MCR &= ~(SER_DTR|SER_RTS);
+		local_irq_save(flags);
+		rtsdtr_ctrl(info->MCR);
+		local_irq_restore(flags);
+	}
+
+	/* Handle transition away from B0 status */
+	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
+		info->MCR |= SER_DTR;
+		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
+			info->MCR |= SER_RTS;
+		local_irq_save(flags);
+		rtsdtr_ctrl(info->MCR);
+		local_irq_restore(flags);
+	}
+
+	/* Handle turning off CRTSCTS */
+	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
+		tty->hw_stopped = false;
+		rs_start(tty);
+	}
+
+#if 0
+	/*
+	 * No need to wake up processes in open wait, since they
+	 * sample the CLOCAL flag once, and don't recheck it.
+	 * XXX  It's not clear whether the current behavior is correct
+	 * or not.  Hence, this may change.....
+	 */
+	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
+		wake_up_interruptible(&info->open_wait);
+#endif
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_close()
+ * 
+ * This routine is called when the serial port gets closed.  First, we
+ * wait for the last remaining data to be sent.  Then, we unlink its
+ * async structure from the interrupt chain if necessary, and we free
+ * that IRQ if nothing is left in the chain.
+ * ------------------------------------------------------------
+ */
+static void rs_close(struct tty_struct *tty, struct file * filp)
+{
+	struct serial_state *state = tty->driver_data;
+	struct tty_port *port = &state->tport;
+
+	if (tty_port_close_start(port, tty, filp) == 0)
+		return;
+
+	/*
+	 * At this point we stop accepting input.  To do this, we
+	 * disable the receive line status interrupts, and tell the
+	 * interrupt driver to stop checking the data ready bit in the
+	 * line status register.
+	 */
+	state->read_status_mask &= ~UART_LSR_DR;
+	if (tty_port_initialized(port)) {
+	        /* disable receive interrupts */
+	        amiga_custom.intena = IF_RBF;
+		mb();
+		/* clear any pending receive interrupt */
+		amiga_custom.intreq = IF_RBF;
+		mb();
+
+		/*
+		 * Before we drop DTR, make sure the UART transmitter
+		 * has completely drained; this is especially
+		 * important if there is a transmit FIFO!
+		 */
+		rs_wait_until_sent(tty, state->timeout);
+	}
+	shutdown(tty, state);
+	rs_flush_buffer(tty);
+		
+	tty_ldisc_flush(tty);
+	port->tty = NULL;
+
+	tty_port_close_end(port, tty);
+}
+
+/*
+ * rs_wait_until_sent() --- wait until the transmitter is empty
+ */
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long orig_jiffies, char_time;
+	int lsr;
+
+	orig_jiffies = jiffies;
+
+	/*
+	 * Set the check interval to be 1/5 of the estimated time to
+	 * send a single character, and make it at least 1.  The check
+	 * interval should also be less than the timeout.
+	 * 
+	 * Note: we have to use pretty tight timings here to satisfy
+	 * the NIST-PCTS.
+	 */
+	char_time = (info->timeout - HZ/50) / XMIT_FIFO_SIZE;
+	char_time = char_time / 5;
+	if (char_time == 0)
+		char_time = 1;
+	if (timeout)
+	  char_time = min_t(unsigned long, char_time, timeout);
+	/*
+	 * If the transmitter hasn't cleared in twice the approximate
+	 * amount of time to send the entire FIFO, it probably won't
+	 * ever clear.  This assumes the UART isn't doing flow
+	 * control, which is currently the case.  Hence, if it ever
+	 * takes longer than info->timeout, this is probably due to a
+	 * UART bug of some kind.  So, we clamp the timeout parameter at
+	 * 2*info->timeout.
+	 */
+	if (!timeout || timeout > 2*info->timeout)
+		timeout = 2*info->timeout;
+#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
+	printk("jiff=%lu...", jiffies);
+#endif
+	while(!((lsr = amiga_custom.serdatr) & SDR_TSRE)) {
+#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
+#endif
+		msleep_interruptible(jiffies_to_msecs(char_time));
+		if (signal_pending(current))
+			break;
+		if (timeout && time_after(jiffies, orig_jiffies + timeout))
+			break;
+	}
+	__set_current_state(TASK_RUNNING);
+
+#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
+#endif
+}
+
+/*
+ * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
+ */
+static void rs_hangup(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	rs_flush_buffer(tty);
+	shutdown(tty, info);
+	info->tport.count = 0;
+	tty_port_set_active(&info->tport, false);
+	info->tport.tty = NULL;
+	wake_up_interruptible(&info->tport.open_wait);
+}
+
+/*
+ * This routine is called whenever a serial port is opened.  It
+ * enables interrupts for a serial port, linking in its async structure into
+ * the IRQ chain.   It also performs the serial-specific
+ * initialization for the tty structure.
+ */
+static int rs_open(struct tty_struct *tty, struct file * filp)
+{
+	struct tty_port *port = tty->port;
+	struct serial_state *info = container_of(port, struct serial_state,
+			tport);
+	int retval;
+
+	port->count++;
+	port->tty = tty;
+	tty->driver_data = info;
+
+	retval = startup(tty, info);
+	if (retval) {
+		return retval;
+	}
+
+	return tty_port_block_til_ready(port, tty, filp);
+}
+
+/*
+ * /proc fs routines....
+ */
+
+static inline void line_info(struct seq_file *m, int line,
+		struct serial_state *state)
+{
+	char	stat_buf[30], control, status;
+	unsigned long flags;
+
+	seq_printf(m, "%d: uart:amiga_builtin", line);
+
+	local_irq_save(flags);
+	status = ciab.pra;
+	control = tty_port_initialized(&state->tport) ? state->MCR : status;
+	local_irq_restore(flags);
+
+	stat_buf[0] = 0;
+	stat_buf[1] = 0;
+	if(!(control & SER_RTS))
+		strcat(stat_buf, "|RTS");
+	if(!(status & SER_CTS))
+		strcat(stat_buf, "|CTS");
+	if(!(control & SER_DTR))
+		strcat(stat_buf, "|DTR");
+	if(!(status & SER_DSR))
+		strcat(stat_buf, "|DSR");
+	if(!(status & SER_DCD))
+		strcat(stat_buf, "|CD");
+
+	if (state->quot)
+		seq_printf(m, " baud:%d", state->baud_base / state->quot);
+
+	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
+
+	if (state->icount.frame)
+		seq_printf(m, " fe:%d", state->icount.frame);
+
+	if (state->icount.parity)
+		seq_printf(m, " pe:%d", state->icount.parity);
+
+	if (state->icount.brk)
+		seq_printf(m, " brk:%d", state->icount.brk);
+
+	if (state->icount.overrun)
+		seq_printf(m, " oe:%d", state->icount.overrun);
+
+	/*
+	 * Last thing is the RS-232 status lines
+	 */
+	seq_printf(m, " %s\n", stat_buf+1);
+}
+
+static int rs_proc_show(struct seq_file *m, void *v)
+{
+	seq_printf(m, "serinfo:1.0 driver:4.30\n");
+	line_info(m, 0, &serial_state);
+	return 0;
+}
+
+/*
+ * ---------------------------------------------------------------------
+ * rs_init() and friends
+ *
+ * rs_init() is called at boot-time to initialize the serial driver.
+ * ---------------------------------------------------------------------
+ */
+
+static const struct tty_operations serial_ops = {
+	.open = rs_open,
+	.close = rs_close,
+	.write = rs_write,
+	.put_char = rs_put_char,
+	.flush_chars = rs_flush_chars,
+	.write_room = rs_write_room,
+	.chars_in_buffer = rs_chars_in_buffer,
+	.flush_buffer = rs_flush_buffer,
+	.ioctl = rs_ioctl,
+	.throttle = rs_throttle,
+	.unthrottle = rs_unthrottle,
+	.set_termios = rs_set_termios,
+	.stop = rs_stop,
+	.start = rs_start,
+	.hangup = rs_hangup,
+	.break_ctl = rs_break,
+	.send_xchar = rs_send_xchar,
+	.wait_until_sent = rs_wait_until_sent,
+	.tiocmget = rs_tiocmget,
+	.tiocmset = rs_tiocmset,
+	.get_icount = rs_get_icount,
+	.set_serial = set_serial_info,
+	.get_serial = get_serial_info,
+	.proc_show = rs_proc_show,
+};
+
+static bool amiga_carrier_raised(struct tty_port *port)
+{
+	return !(ciab.pra & SER_DCD);
+}
+
+static void amiga_dtr_rts(struct tty_port *port, bool active)
+{
+	struct serial_state *info = container_of(port, struct serial_state,
+			tport);
+	unsigned long flags;
+
+	if (active)
+		info->MCR |= SER_DTR|SER_RTS;
+	else
+		info->MCR &= ~(SER_DTR|SER_RTS);
+
+	local_irq_save(flags);
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+}
+
+static const struct tty_port_operations amiga_port_ops = {
+	.carrier_raised = amiga_carrier_raised,
+	.dtr_rts = amiga_dtr_rts,
+};
+
+/*
+ * The serial driver boot-time initialization code!
+ */
+static int __init amiga_serial_probe(struct platform_device *pdev)
+{
+	struct serial_state *state = &serial_state;
+	struct tty_driver *driver;
+	unsigned long flags;
+	int error;
+
+	driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
+
+	/* Initialize the tty_driver structure */
+
+	driver->driver_name = "amiserial";
+	driver->name = "ttyS";
+	driver->major = TTY_MAJOR;
+	driver->minor_start = 64;
+	driver->type = TTY_DRIVER_TYPE_SERIAL;
+	driver->subtype = SERIAL_TYPE_NORMAL;
+	driver->init_termios = tty_std_termios;
+	driver->init_termios.c_cflag =
+		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	tty_set_operations(driver, &serial_ops);
+
+	memset(state, 0, sizeof(*state));
+	state->port = (int)&amiga_custom.serdatr; /* Just to give it a value */
+	tty_port_init(&state->tport);
+	state->tport.ops = &amiga_port_ops;
+	tty_port_link_device(&state->tport, driver, 0);
+
+	error = tty_register_driver(driver);
+	if (error)
+		goto fail_tty_driver_kref_put;
+
+	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
+
+	/* Hardware set up */
+
+	state->baud_base = amiga_colorclock;
+
+	/* set ISRs, and then disable the rx interrupts */
+	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
+	if (error)
+		goto fail_unregister;
+
+	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
+			    "serial RX", state);
+	if (error)
+		goto fail_free_irq;
+
+	local_irq_save(flags);
+
+	/* turn off Rx and Tx interrupts */
+	amiga_custom.intena = IF_RBF | IF_TBE;
+	mb();
+
+	/* clear any pending interrupt */
+	amiga_custom.intreq = IF_RBF | IF_TBE;
+	mb();
+
+	local_irq_restore(flags);
+
+	/*
+	 * set the appropriate directions for the modem control flags,
+	 * and clear RTS and DTR
+	 */
+	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
+	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
+
+	platform_set_drvdata(pdev, state);
+
+	serial_driver = driver;
+
+	return 0;
+
+fail_free_irq:
+	free_irq(IRQ_AMIGA_TBE, state);
+fail_unregister:
+	tty_unregister_driver(driver);
+fail_tty_driver_kref_put:
+	tty_port_destroy(&state->tport);
+	tty_driver_kref_put(driver);
+	return error;
+}
+
+static int __exit amiga_serial_remove(struct platform_device *pdev)
+{
+	struct serial_state *state = platform_get_drvdata(pdev);
+
+	tty_unregister_driver(serial_driver);
+	tty_driver_kref_put(serial_driver);
+	tty_port_destroy(&state->tport);
+
+	free_irq(IRQ_AMIGA_TBE, state);
+	free_irq(IRQ_AMIGA_RBF, state);
+
+	return 0;
+}
+
+static struct platform_driver amiga_serial_driver = {
+	.remove = __exit_p(amiga_serial_remove),
+	.driver   = {
+		.name	= "amiga-serial",
+	},
+};
+
+module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
+
+
+#if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
+
+/*
+ * ------------------------------------------------------------
+ * Serial console driver
+ * ------------------------------------------------------------
+ */
+
+static void amiga_serial_putc(char c)
+{
+	amiga_custom.serdat = (unsigned char)c | 0x100;
+	while (!(amiga_custom.serdatr & 0x2000))
+		barrier();
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console must be locked when we get here.
+ */
+static void serial_console_write(struct console *co, const char *s,
+				unsigned count)
+{
+	unsigned short intena = amiga_custom.intenar;
+
+	amiga_custom.intena = IF_TBE;
+
+	while (count--) {
+		if (*s == '\n')
+			amiga_serial_putc('\r');
+		amiga_serial_putc(*s++);
+	}
+
+	amiga_custom.intena = IF_SETCLR | (intena & IF_TBE);
+}
+
+static struct tty_driver *serial_console_device(struct console *c, int *index)
+{
+	*index = 0;
+	return serial_driver;
+}
+
+static struct console sercons = {
+	.name =		"ttyS",
+	.write =	serial_console_write,
+	.device =	serial_console_device,
+	.flags =	CON_PRINTBUFFER,
+	.index =	-1,
+};
+
+/*
+ *	Register console.
+ */
+static int __init amiserial_console_init(void)
+{
+	if (!MACH_IS_AMIGA)
+		return -ENODEV;
+
+	register_console(&sercons);
+	return 0;
+}
+console_initcall(amiserial_console_init);
+
+#endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:amiga-serial");
diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c
new file mode 100644
index 000000000..a067628e0
--- /dev/null
+++ b/drivers/tty/ehv_bytechan.c
@@ -0,0 +1,818 @@
+// SPDX-License-Identifier: GPL-2.0
+/* ePAPR hypervisor byte channel device driver
+ *
+ * Copyright 2009-2011 Freescale Semiconductor, Inc.
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * This driver support three distinct interfaces, all of which are related to
+ * ePAPR hypervisor byte channels.
+ *
+ * 1) An early-console (udbg) driver.  This provides early console output
+ * through a byte channel.  The byte channel handle must be specified in a
+ * Kconfig option.
+ *
+ * 2) A normal console driver.  Output is sent to the byte channel designated
+ * for stdout in the device tree.  The console driver is for handling kernel
+ * printk calls.
+ *
+ * 3) A tty driver, which is used to handle user-space input and output.  The
+ * byte channel used for the console is designated as the default tty.
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <asm/epapr_hcalls.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/cdev.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/circ_buf.h>
+#include <asm/udbg.h>
+
+/* The size of the transmit circular buffer.  This must be a power of two. */
+#define BUF_SIZE	2048
+
+/* Per-byte channel private data */
+struct ehv_bc_data {
+	struct device *dev;
+	struct tty_port port;
+	uint32_t handle;
+	unsigned int rx_irq;
+	unsigned int tx_irq;
+
+	spinlock_t lock;	/* lock for transmit buffer */
+	unsigned char buf[BUF_SIZE];	/* transmit circular buffer */
+	unsigned int head;	/* circular buffer head */
+	unsigned int tail;	/* circular buffer tail */
+
+	int tx_irq_enabled;	/* true == TX interrupt is enabled */
+};
+
+/* Array of byte channel objects */
+static struct ehv_bc_data *bcs;
+
+/* Byte channel handle for stdout (and stdin), taken from device tree */
+static unsigned int stdout_bc;
+
+/* Virtual IRQ for the byte channel handle for stdin, taken from device tree */
+static unsigned int stdout_irq;
+
+/**************************** SUPPORT FUNCTIONS ****************************/
+
+/*
+ * Enable the transmit interrupt
+ *
+ * Unlike a serial device, byte channels have no mechanism for disabling their
+ * own receive or transmit interrupts.  To emulate that feature, we toggle
+ * the IRQ in the kernel.
+ *
+ * We cannot just blindly call enable_irq() or disable_irq(), because these
+ * calls are reference counted.  This means that we cannot call enable_irq()
+ * if interrupts are already enabled.  This can happen in two situations:
+ *
+ * 1. The tty layer makes two back-to-back calls to ehv_bc_tty_write()
+ * 2. A transmit interrupt occurs while executing ehv_bc_tx_dequeue()
+ *
+ * To work around this, we keep a flag to tell us if the IRQ is enabled or not.
+ */
+static void enable_tx_interrupt(struct ehv_bc_data *bc)
+{
+	if (!bc->tx_irq_enabled) {
+		enable_irq(bc->tx_irq);
+		bc->tx_irq_enabled = 1;
+	}
+}
+
+static void disable_tx_interrupt(struct ehv_bc_data *bc)
+{
+	if (bc->tx_irq_enabled) {
+		disable_irq_nosync(bc->tx_irq);
+		bc->tx_irq_enabled = 0;
+	}
+}
+
+/*
+ * find the byte channel handle to use for the console
+ *
+ * The byte channel to be used for the console is specified via a "stdout"
+ * property in the /chosen node.
+ */
+static int find_console_handle(void)
+{
+	struct device_node *np = of_stdout;
+	const uint32_t *iprop;
+
+	/* We don't care what the aliased node is actually called.  We only
+	 * care if it's compatible with "epapr,hv-byte-channel", because that
+	 * indicates that it's a byte channel node.
+	 */
+	if (!np || !of_device_is_compatible(np, "epapr,hv-byte-channel"))
+		return 0;
+
+	stdout_irq = irq_of_parse_and_map(np, 0);
+	if (!stdout_irq) {
+		pr_err("ehv-bc: no 'interrupts' property in %pOF node\n", np);
+		return 0;
+	}
+
+	/*
+	 * The 'hv-handle' property contains the handle for this byte channel.
+	 */
+	iprop = of_get_property(np, "hv-handle", NULL);
+	if (!iprop) {
+		pr_err("ehv-bc: no 'hv-handle' property in %pOFn node\n",
+		       np);
+		return 0;
+	}
+	stdout_bc = be32_to_cpu(*iprop);
+	return 1;
+}
+
+static unsigned int local_ev_byte_channel_send(unsigned int handle,
+					       unsigned int *count,
+					       const char *p)
+{
+	char buffer[EV_BYTE_CHANNEL_MAX_BYTES];
+	unsigned int c = *count;
+
+	if (c < sizeof(buffer)) {
+		memcpy(buffer, p, c);
+		memset(&buffer[c], 0, sizeof(buffer) - c);
+		p = buffer;
+	}
+	return ev_byte_channel_send(handle, count, p);
+}
+
+/*************************** EARLY CONSOLE DRIVER ***************************/
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_EHV_BC
+
+/*
+ * send a byte to a byte channel, wait if necessary
+ *
+ * This function sends a byte to a byte channel, and it waits and
+ * retries if the byte channel is full.  It returns if the character
+ * has been sent, or if some error has occurred.
+ *
+ */
+static void byte_channel_spin_send(const char data)
+{
+	int ret, count;
+
+	do {
+		count = 1;
+		ret = local_ev_byte_channel_send(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE,
+					   &count, &data);
+	} while (ret == EV_EAGAIN);
+}
+
+/*
+ * The udbg subsystem calls this function to display a single character.
+ * We convert CR to a CR/LF.
+ */
+static void ehv_bc_udbg_putc(char c)
+{
+	if (c == '\n')
+		byte_channel_spin_send('\r');
+
+	byte_channel_spin_send(c);
+}
+
+/*
+ * early console initialization
+ *
+ * PowerPC kernels support an early printk console, also known as udbg.
+ * This function must be called via the ppc_md.init_early function pointer.
+ * At this point, the device tree has been unflattened, so we can obtain the
+ * byte channel handle for stdout.
+ *
+ * We only support displaying of characters (putc).  We do not support
+ * keyboard input.
+ */
+void __init udbg_init_ehv_bc(void)
+{
+	unsigned int rx_count, tx_count;
+	unsigned int ret;
+
+	/* Verify the byte channel handle */
+	ret = ev_byte_channel_poll(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE,
+				   &rx_count, &tx_count);
+	if (ret)
+		return;
+
+	udbg_putc = ehv_bc_udbg_putc;
+	register_early_udbg_console();
+
+	udbg_printf("ehv-bc: early console using byte channel handle %u\n",
+		    CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE);
+}
+
+#endif
+
+/****************************** CONSOLE DRIVER ******************************/
+
+static struct tty_driver *ehv_bc_driver;
+
+/*
+ * Byte channel console sending worker function.
+ *
+ * For consoles, if the output buffer is full, we should just spin until it
+ * clears.
+ */
+static int ehv_bc_console_byte_channel_send(unsigned int handle, const char *s,
+			     unsigned int count)
+{
+	unsigned int len;
+	int ret = 0;
+
+	while (count) {
+		len = min_t(unsigned int, count, EV_BYTE_CHANNEL_MAX_BYTES);
+		do {
+			ret = local_ev_byte_channel_send(handle, &len, s);
+		} while (ret == EV_EAGAIN);
+		count -= len;
+		s += len;
+	}
+
+	return ret;
+}
+
+/*
+ * write a string to the console
+ *
+ * This function gets called to write a string from the kernel, typically from
+ * a printk().  This function spins until all data is written.
+ *
+ * We copy the data to a temporary buffer because we need to insert a \r in
+ * front of every \n.  It's more efficient to copy the data to the buffer than
+ * it is to make multiple hcalls for each character or each newline.
+ */
+static void ehv_bc_console_write(struct console *co, const char *s,
+				 unsigned int count)
+{
+	char s2[EV_BYTE_CHANNEL_MAX_BYTES];
+	unsigned int i, j = 0;
+	char c;
+
+	for (i = 0; i < count; i++) {
+		c = *s++;
+
+		if (c == '\n')
+			s2[j++] = '\r';
+
+		s2[j++] = c;
+		if (j >= (EV_BYTE_CHANNEL_MAX_BYTES - 1)) {
+			if (ehv_bc_console_byte_channel_send(stdout_bc, s2, j))
+				return;
+			j = 0;
+		}
+	}
+
+	if (j)
+		ehv_bc_console_byte_channel_send(stdout_bc, s2, j);
+}
+
+/*
+ * When /dev/console is opened, the kernel iterates the console list looking
+ * for one with ->device and then calls that method. On success, it expects
+ * the passed-in int* to contain the minor number to use.
+ */
+static struct tty_driver *ehv_bc_console_device(struct console *co, int *index)
+{
+	*index = co->index;
+
+	return ehv_bc_driver;
+}
+
+static struct console ehv_bc_console = {
+	.name		= "ttyEHV",
+	.write		= ehv_bc_console_write,
+	.device		= ehv_bc_console_device,
+	.flags		= CON_PRINTBUFFER | CON_ENABLED,
+};
+
+/*
+ * Console initialization
+ *
+ * This is the first function that is called after the device tree is
+ * available, so here is where we determine the byte channel handle and IRQ for
+ * stdout/stdin, even though that information is used by the tty and character
+ * drivers.
+ */
+static int __init ehv_bc_console_init(void)
+{
+	if (!find_console_handle()) {
+		pr_debug("ehv-bc: stdout is not a byte channel\n");
+		return -ENODEV;
+	}
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_EHV_BC
+	/* Print a friendly warning if the user chose the wrong byte channel
+	 * handle for udbg.
+	 */
+	if (stdout_bc != CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE)
+		pr_warn("ehv-bc: udbg handle %u is not the stdout handle\n",
+			CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE);
+#endif
+
+	/* add_preferred_console() must be called before register_console(),
+	   otherwise it won't work.  However, we don't want to enumerate all the
+	   byte channels here, either, since we only care about one. */
+
+	add_preferred_console(ehv_bc_console.name, ehv_bc_console.index, NULL);
+	register_console(&ehv_bc_console);
+
+	pr_info("ehv-bc: registered console driver for byte channel %u\n",
+		stdout_bc);
+
+	return 0;
+}
+console_initcall(ehv_bc_console_init);
+
+/******************************** TTY DRIVER ********************************/
+
+/*
+ * byte channel receive interrupt handler
+ *
+ * This ISR is called whenever data is available on a byte channel.
+ */
+static irqreturn_t ehv_bc_tty_rx_isr(int irq, void *data)
+{
+	struct ehv_bc_data *bc = data;
+	unsigned int rx_count, tx_count, len;
+	int count;
+	char buffer[EV_BYTE_CHANNEL_MAX_BYTES];
+	int ret;
+
+	/* Find out how much data needs to be read, and then ask the TTY layer
+	 * if it can handle that much.  We want to ensure that every byte we
+	 * read from the byte channel will be accepted by the TTY layer.
+	 */
+	ev_byte_channel_poll(bc->handle, &rx_count, &tx_count);
+	count = tty_buffer_request_room(&bc->port, rx_count);
+
+	/* 'count' is the maximum amount of data the TTY layer can accept at
+	 * this time.  However, during testing, I was never able to get 'count'
+	 * to be less than 'rx_count'.  I'm not sure whether I'm calling it
+	 * correctly.
+	 */
+
+	while (count > 0) {
+		len = min_t(unsigned int, count, sizeof(buffer));
+
+		/* Read some data from the byte channel.  This function will
+		 * never return more than EV_BYTE_CHANNEL_MAX_BYTES bytes.
+		 */
+		ev_byte_channel_receive(bc->handle, &len, buffer);
+
+		/* 'len' is now the amount of data that's been received. 'len'
+		 * can't be zero, and most likely it's equal to one.
+		 */
+
+		/* Pass the received data to the tty layer. */
+		ret = tty_insert_flip_string(&bc->port, buffer, len);
+
+		/* 'ret' is the number of bytes that the TTY layer accepted.
+		 * If it's not equal to 'len', then it means the buffer is
+		 * full, which should never happen.  If it does happen, we can
+		 * exit gracefully, but we drop the last 'len - ret' characters
+		 * that we read from the byte channel.
+		 */
+		if (ret != len)
+			break;
+
+		count -= len;
+	}
+
+	/* Tell the tty layer that we're done. */
+	tty_flip_buffer_push(&bc->port);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * dequeue the transmit buffer to the hypervisor
+ *
+ * This function, which can be called in interrupt context, dequeues as much
+ * data as possible from the transmit buffer to the byte channel.
+ */
+static void ehv_bc_tx_dequeue(struct ehv_bc_data *bc)
+{
+	unsigned int count;
+	unsigned int len, ret;
+	unsigned long flags;
+
+	do {
+		spin_lock_irqsave(&bc->lock, flags);
+		len = min_t(unsigned int,
+			    CIRC_CNT_TO_END(bc->head, bc->tail, BUF_SIZE),
+			    EV_BYTE_CHANNEL_MAX_BYTES);
+
+		ret = local_ev_byte_channel_send(bc->handle, &len, bc->buf + bc->tail);
+
+		/* 'len' is valid only if the return code is 0 or EV_EAGAIN */
+		if (!ret || (ret == EV_EAGAIN))
+			bc->tail = (bc->tail + len) & (BUF_SIZE - 1);
+
+		count = CIRC_CNT(bc->head, bc->tail, BUF_SIZE);
+		spin_unlock_irqrestore(&bc->lock, flags);
+	} while (count && !ret);
+
+	spin_lock_irqsave(&bc->lock, flags);
+	if (CIRC_CNT(bc->head, bc->tail, BUF_SIZE))
+		/*
+		 * If we haven't emptied the buffer, then enable the TX IRQ.
+		 * We'll get an interrupt when there's more room in the
+		 * hypervisor's output buffer.
+		 */
+		enable_tx_interrupt(bc);
+	else
+		disable_tx_interrupt(bc);
+	spin_unlock_irqrestore(&bc->lock, flags);
+}
+
+/*
+ * byte channel transmit interrupt handler
+ *
+ * This ISR is called whenever space becomes available for transmitting
+ * characters on a byte channel.
+ */
+static irqreturn_t ehv_bc_tty_tx_isr(int irq, void *data)
+{
+	struct ehv_bc_data *bc = data;
+
+	ehv_bc_tx_dequeue(bc);
+	tty_port_tty_wakeup(&bc->port);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * This function is called when the tty layer has data for us send.  We store
+ * the data first in a circular buffer, and then dequeue as much of that data
+ * as possible.
+ *
+ * We don't need to worry about whether there is enough room in the buffer for
+ * all the data.  The purpose of ehv_bc_tty_write_room() is to tell the tty
+ * layer how much data it can safely send to us.  We guarantee that
+ * ehv_bc_tty_write_room() will never lie, so the tty layer will never send us
+ * too much data.
+ */
+static ssize_t ehv_bc_tty_write(struct tty_struct *ttys, const u8 *s,
+				size_t count)
+{
+	struct ehv_bc_data *bc = ttys->driver_data;
+	unsigned long flags;
+	unsigned int len;
+	unsigned int written = 0;
+
+	while (1) {
+		spin_lock_irqsave(&bc->lock, flags);
+		len = CIRC_SPACE_TO_END(bc->head, bc->tail, BUF_SIZE);
+		if (count < len)
+			len = count;
+		if (len) {
+			memcpy(bc->buf + bc->head, s, len);
+			bc->head = (bc->head + len) & (BUF_SIZE - 1);
+		}
+		spin_unlock_irqrestore(&bc->lock, flags);
+		if (!len)
+			break;
+
+		s += len;
+		count -= len;
+		written += len;
+	}
+
+	ehv_bc_tx_dequeue(bc);
+
+	return written;
+}
+
+/*
+ * This function can be called multiple times for a given tty_struct, which is
+ * why we initialize bc->ttys in ehv_bc_tty_port_activate() instead.
+ *
+ * The tty layer will still call this function even if the device was not
+ * registered (i.e. tty_register_device() was not called).  This happens
+ * because tty_register_device() is optional and some legacy drivers don't
+ * use it.  So we need to check for that.
+ */
+static int ehv_bc_tty_open(struct tty_struct *ttys, struct file *filp)
+{
+	struct ehv_bc_data *bc = &bcs[ttys->index];
+
+	if (!bc->dev)
+		return -ENODEV;
+
+	return tty_port_open(&bc->port, ttys, filp);
+}
+
+/*
+ * Amazingly, if ehv_bc_tty_open() returns an error code, the tty layer will
+ * still call this function to close the tty device.  So we can't assume that
+ * the tty port has been initialized.
+ */
+static void ehv_bc_tty_close(struct tty_struct *ttys, struct file *filp)
+{
+	struct ehv_bc_data *bc = &bcs[ttys->index];
+
+	if (bc->dev)
+		tty_port_close(&bc->port, ttys, filp);
+}
+
+/*
+ * Return the amount of space in the output buffer
+ *
+ * This is actually a contract between the driver and the tty layer outlining
+ * how much write room the driver can guarantee will be sent OR BUFFERED.  This
+ * driver MUST honor the return value.
+ */
+static unsigned int ehv_bc_tty_write_room(struct tty_struct *ttys)
+{
+	struct ehv_bc_data *bc = ttys->driver_data;
+	unsigned long flags;
+	unsigned int count;
+
+	spin_lock_irqsave(&bc->lock, flags);
+	count = CIRC_SPACE(bc->head, bc->tail, BUF_SIZE);
+	spin_unlock_irqrestore(&bc->lock, flags);
+
+	return count;
+}
+
+/*
+ * Stop sending data to the tty layer
+ *
+ * This function is called when the tty layer's input buffers are getting full,
+ * so the driver should stop sending it data.  The easiest way to do this is to
+ * disable the RX IRQ, which will prevent ehv_bc_tty_rx_isr() from being
+ * called.
+ *
+ * The hypervisor will continue to queue up any incoming data.  If there is any
+ * data in the queue when the RX interrupt is enabled, we'll immediately get an
+ * RX interrupt.
+ */
+static void ehv_bc_tty_throttle(struct tty_struct *ttys)
+{
+	struct ehv_bc_data *bc = ttys->driver_data;
+
+	disable_irq(bc->rx_irq);
+}
+
+/*
+ * Resume sending data to the tty layer
+ *
+ * This function is called after previously calling ehv_bc_tty_throttle().  The
+ * tty layer's input buffers now have more room, so the driver can resume
+ * sending it data.
+ */
+static void ehv_bc_tty_unthrottle(struct tty_struct *ttys)
+{
+	struct ehv_bc_data *bc = ttys->driver_data;
+
+	/* If there is any data in the queue when the RX interrupt is enabled,
+	 * we'll immediately get an RX interrupt.
+	 */
+	enable_irq(bc->rx_irq);
+}
+
+static void ehv_bc_tty_hangup(struct tty_struct *ttys)
+{
+	struct ehv_bc_data *bc = ttys->driver_data;
+
+	ehv_bc_tx_dequeue(bc);
+	tty_port_hangup(&bc->port);
+}
+
+/*
+ * TTY driver operations
+ *
+ * If we could ask the hypervisor how much data is still in the TX buffer, or
+ * at least how big the TX buffers are, then we could implement the
+ * .wait_until_sent and .chars_in_buffer functions.
+ */
+static const struct tty_operations ehv_bc_ops = {
+	.open		= ehv_bc_tty_open,
+	.close		= ehv_bc_tty_close,
+	.write		= ehv_bc_tty_write,
+	.write_room	= ehv_bc_tty_write_room,
+	.throttle	= ehv_bc_tty_throttle,
+	.unthrottle	= ehv_bc_tty_unthrottle,
+	.hangup		= ehv_bc_tty_hangup,
+};
+
+/*
+ * initialize the TTY port
+ *
+ * This function will only be called once, no matter how many times
+ * ehv_bc_tty_open() is called.  That's why we register the ISR here, and also
+ * why we initialize tty_struct-related variables here.
+ */
+static int ehv_bc_tty_port_activate(struct tty_port *port,
+				    struct tty_struct *ttys)
+{
+	struct ehv_bc_data *bc = container_of(port, struct ehv_bc_data, port);
+	int ret;
+
+	ttys->driver_data = bc;
+
+	ret = request_irq(bc->rx_irq, ehv_bc_tty_rx_isr, 0, "ehv-bc", bc);
+	if (ret < 0) {
+		dev_err(bc->dev, "could not request rx irq %u (ret=%i)\n",
+		       bc->rx_irq, ret);
+		return ret;
+	}
+
+	/* request_irq also enables the IRQ */
+	bc->tx_irq_enabled = 1;
+
+	ret = request_irq(bc->tx_irq, ehv_bc_tty_tx_isr, 0, "ehv-bc", bc);
+	if (ret < 0) {
+		dev_err(bc->dev, "could not request tx irq %u (ret=%i)\n",
+		       bc->tx_irq, ret);
+		free_irq(bc->rx_irq, bc);
+		return ret;
+	}
+
+	/* The TX IRQ is enabled only when we can't write all the data to the
+	 * byte channel at once, so by default it's disabled.
+	 */
+	disable_tx_interrupt(bc);
+
+	return 0;
+}
+
+static void ehv_bc_tty_port_shutdown(struct tty_port *port)
+{
+	struct ehv_bc_data *bc = container_of(port, struct ehv_bc_data, port);
+
+	free_irq(bc->tx_irq, bc);
+	free_irq(bc->rx_irq, bc);
+}
+
+static const struct tty_port_operations ehv_bc_tty_port_ops = {
+	.activate = ehv_bc_tty_port_activate,
+	.shutdown = ehv_bc_tty_port_shutdown,
+};
+
+static int ehv_bc_tty_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct ehv_bc_data *bc;
+	const uint32_t *iprop;
+	unsigned int handle;
+	int ret;
+	static unsigned int index = 1;
+	unsigned int i;
+
+	iprop = of_get_property(np, "hv-handle", NULL);
+	if (!iprop) {
+		dev_err(&pdev->dev, "no 'hv-handle' property in %pOFn node\n",
+			np);
+		return -ENODEV;
+	}
+
+	/* We already told the console layer that the index for the console
+	 * device is zero, so we need to make sure that we use that index when
+	 * we probe the console byte channel node.
+	 */
+	handle = be32_to_cpu(*iprop);
+	i = (handle == stdout_bc) ? 0 : index++;
+	bc = &bcs[i];
+
+	bc->handle = handle;
+	bc->head = 0;
+	bc->tail = 0;
+	spin_lock_init(&bc->lock);
+
+	bc->rx_irq = irq_of_parse_and_map(np, 0);
+	bc->tx_irq = irq_of_parse_and_map(np, 1);
+	if (!bc->rx_irq || !bc->tx_irq) {
+		dev_err(&pdev->dev, "no 'interrupts' property in %pOFn node\n",
+			np);
+		ret = -ENODEV;
+		goto error;
+	}
+
+	tty_port_init(&bc->port);
+	bc->port.ops = &ehv_bc_tty_port_ops;
+
+	bc->dev = tty_port_register_device(&bc->port, ehv_bc_driver, i,
+			&pdev->dev);
+	if (IS_ERR(bc->dev)) {
+		ret = PTR_ERR(bc->dev);
+		dev_err(&pdev->dev, "could not register tty (ret=%i)\n", ret);
+		goto error;
+	}
+
+	dev_set_drvdata(&pdev->dev, bc);
+
+	dev_info(&pdev->dev, "registered /dev/%s%u for byte channel %u\n",
+		ehv_bc_driver->name, i, bc->handle);
+
+	return 0;
+
+error:
+	tty_port_destroy(&bc->port);
+	irq_dispose_mapping(bc->tx_irq);
+	irq_dispose_mapping(bc->rx_irq);
+
+	memset(bc, 0, sizeof(struct ehv_bc_data));
+	return ret;
+}
+
+static const struct of_device_id ehv_bc_tty_of_ids[] = {
+	{ .compatible = "epapr,hv-byte-channel" },
+	{}
+};
+
+static struct platform_driver ehv_bc_tty_driver = {
+	.driver = {
+		.name = "ehv-bc",
+		.of_match_table = ehv_bc_tty_of_ids,
+		.suppress_bind_attrs = true,
+	},
+	.probe		= ehv_bc_tty_probe,
+};
+
+/**
+ * ehv_bc_init - ePAPR hypervisor byte channel driver initialization
+ *
+ * This function is called when this driver is loaded.
+ */
+static int __init ehv_bc_init(void)
+{
+	struct tty_driver *driver;
+	struct device_node *np;
+	unsigned int count = 0; /* Number of elements in bcs[] */
+	int ret;
+
+	pr_info("ePAPR hypervisor byte channel driver\n");
+
+	/* Count the number of byte channels */
+	for_each_compatible_node(np, NULL, "epapr,hv-byte-channel")
+		count++;
+
+	if (!count)
+		return -ENODEV;
+
+	/* The array index of an element in bcs[] is the same as the tty index
+	 * for that element.  If you know the address of an element in the
+	 * array, then you can use pointer math (e.g. "bc - bcs") to get its
+	 * tty index.
+	 */
+	bcs = kcalloc(count, sizeof(struct ehv_bc_data), GFP_KERNEL);
+	if (!bcs)
+		return -ENOMEM;
+
+	driver = tty_alloc_driver(count, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(driver)) {
+		ret = PTR_ERR(driver);
+		goto err_free_bcs;
+	}
+
+	driver->driver_name = "ehv-bc";
+	driver->name = ehv_bc_console.name;
+	driver->type = TTY_DRIVER_TYPE_CONSOLE;
+	driver->subtype = SYSTEM_TYPE_CONSOLE;
+	driver->init_termios = tty_std_termios;
+	tty_set_operations(driver, &ehv_bc_ops);
+
+	ret = tty_register_driver(driver);
+	if (ret) {
+		pr_err("ehv-bc: could not register tty driver (ret=%i)\n", ret);
+		goto err_tty_driver_kref_put;
+	}
+
+	ehv_bc_driver = driver;
+
+	ret = platform_driver_register(&ehv_bc_tty_driver);
+	if (ret) {
+		pr_err("ehv-bc: could not register platform driver (ret=%i)\n",
+		       ret);
+		goto err_deregister_tty_driver;
+	}
+
+	return 0;
+
+err_deregister_tty_driver:
+	ehv_bc_driver = NULL;
+	tty_unregister_driver(driver);
+err_tty_driver_kref_put:
+	tty_driver_kref_put(driver);
+err_free_bcs:
+	kfree(bcs);
+
+	return ret;
+}
+device_initcall(ehv_bc_init);
diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c
new file mode 100644
index 000000000..4591f940b
--- /dev/null
+++ b/drivers/tty/goldfish.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (C) 2012 Intel, Inc.
+ * Copyright (C) 2017 Imagination Technologies Ltd.
+ */
+
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/goldfish.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/serial_core.h>
+
+/* Goldfish tty register's offsets */
+#define	GOLDFISH_TTY_REG_BYTES_READY	0x04
+#define	GOLDFISH_TTY_REG_CMD		0x08
+#define	GOLDFISH_TTY_REG_DATA_PTR	0x10
+#define	GOLDFISH_TTY_REG_DATA_LEN	0x14
+#define	GOLDFISH_TTY_REG_DATA_PTR_HIGH	0x18
+#define	GOLDFISH_TTY_REG_VERSION	0x20
+
+/* Goldfish tty commands */
+#define	GOLDFISH_TTY_CMD_INT_DISABLE	0
+#define	GOLDFISH_TTY_CMD_INT_ENABLE	1
+#define	GOLDFISH_TTY_CMD_WRITE_BUFFER	2
+#define	GOLDFISH_TTY_CMD_READ_BUFFER	3
+
+struct goldfish_tty {
+	struct tty_port port;
+	spinlock_t lock;
+	void __iomem *base;
+	u32 irq;
+	int opencount;
+	struct console console;
+	u32 version;
+	struct device *dev;
+};
+
+static DEFINE_MUTEX(goldfish_tty_lock);
+static struct tty_driver *goldfish_tty_driver;
+static u32 goldfish_tty_line_count = 8;
+static u32 goldfish_tty_current_line_count;
+static struct goldfish_tty *goldfish_ttys;
+
+static void do_rw_io(struct goldfish_tty *qtty,
+		     unsigned long address,
+		     unsigned int count,
+		     int is_write)
+{
+	unsigned long irq_flags;
+	void __iomem *base = qtty->base;
+
+	spin_lock_irqsave(&qtty->lock, irq_flags);
+	gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
+		     base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
+	gf_iowrite32(count, base + GOLDFISH_TTY_REG_DATA_LEN);
+
+	if (is_write)
+		gf_iowrite32(GOLDFISH_TTY_CMD_WRITE_BUFFER,
+		       base + GOLDFISH_TTY_REG_CMD);
+	else
+		gf_iowrite32(GOLDFISH_TTY_CMD_READ_BUFFER,
+		       base + GOLDFISH_TTY_REG_CMD);
+
+	spin_unlock_irqrestore(&qtty->lock, irq_flags);
+}
+
+static void goldfish_tty_rw(struct goldfish_tty *qtty,
+			    unsigned long addr,
+			    unsigned int count,
+			    int is_write)
+{
+	dma_addr_t dma_handle;
+	enum dma_data_direction dma_dir;
+
+	dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+	if (qtty->version > 0) {
+		/*
+		 * Goldfish TTY for Ranchu platform uses
+		 * physical addresses and DMA for read/write operations
+		 */
+		unsigned long addr_end = addr + count;
+
+		while (addr < addr_end) {
+			unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE;
+			unsigned long next =
+					pg_end < addr_end ? pg_end : addr_end;
+			unsigned long avail = next - addr;
+
+			/*
+			 * Map the buffer's virtual address to the DMA address
+			 * so the buffer can be accessed by the device.
+			 */
+			dma_handle = dma_map_single(qtty->dev, (void *)addr,
+						    avail, dma_dir);
+
+			if (dma_mapping_error(qtty->dev, dma_handle)) {
+				dev_err(qtty->dev, "tty: DMA mapping error.\n");
+				return;
+			}
+			do_rw_io(qtty, dma_handle, avail, is_write);
+
+			/*
+			 * Unmap the previously mapped region after
+			 * the completion of the read/write operation.
+			 */
+			dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);
+
+			addr += avail;
+		}
+	} else {
+		/*
+		 * Old style Goldfish TTY used on the Goldfish platform
+		 * uses virtual addresses.
+		 */
+		do_rw_io(qtty, addr, count, is_write);
+	}
+}
+
+static void goldfish_tty_do_write(int line, const u8 *buf, unsigned int count)
+{
+	struct goldfish_tty *qtty = &goldfish_ttys[line];
+	unsigned long address = (unsigned long)(void *)buf;
+
+	goldfish_tty_rw(qtty, address, count, 1);
+}
+
+static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
+{
+	struct goldfish_tty *qtty = dev_id;
+	void __iomem *base = qtty->base;
+	unsigned long address;
+	unsigned char *buf;
+	u32 count;
+
+	count = gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
+	if (count == 0)
+		return IRQ_NONE;
+
+	count = tty_prepare_flip_string(&qtty->port, &buf, count);
+
+	address = (unsigned long)(void *)buf;
+	goldfish_tty_rw(qtty, address, count, 0);
+
+	tty_flip_buffer_push(&qtty->port);
+	return IRQ_HANDLED;
+}
+
+static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
+									port);
+	gf_iowrite32(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
+	return 0;
+}
+
+static void goldfish_tty_shutdown(struct tty_port *port)
+{
+	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
+									port);
+	gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
+}
+
+static int goldfish_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
+	return tty_port_open(&qtty->port, tty, filp);
+}
+
+static void goldfish_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	tty_port_close(tty->port, tty, filp);
+}
+
+static void goldfish_tty_hangup(struct tty_struct *tty)
+{
+	tty_port_hangup(tty->port);
+}
+
+static ssize_t goldfish_tty_write(struct tty_struct *tty, const u8 *buf,
+				  size_t count)
+{
+	goldfish_tty_do_write(tty->index, buf, count);
+	return count;
+}
+
+static unsigned int goldfish_tty_write_room(struct tty_struct *tty)
+{
+	return 0x10000;
+}
+
+static unsigned int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
+	void __iomem *base = qtty->base;
+	return gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
+}
+
+static void goldfish_tty_console_write(struct console *co, const char *b,
+								unsigned count)
+{
+	goldfish_tty_do_write(co->index, b, count);
+}
+
+static struct tty_driver *goldfish_tty_console_device(struct console *c,
+								int *index)
+{
+	*index = c->index;
+	return goldfish_tty_driver;
+}
+
+static int goldfish_tty_console_setup(struct console *co, char *options)
+{
+	if ((unsigned)co->index >= goldfish_tty_line_count)
+		return -ENODEV;
+	if (!goldfish_ttys[co->index].base)
+		return -ENODEV;
+	return 0;
+}
+
+static const struct tty_port_operations goldfish_port_ops = {
+	.activate = goldfish_tty_activate,
+	.shutdown = goldfish_tty_shutdown
+};
+
+static const struct tty_operations goldfish_tty_ops = {
+	.open = goldfish_tty_open,
+	.close = goldfish_tty_close,
+	.hangup = goldfish_tty_hangup,
+	.write = goldfish_tty_write,
+	.write_room = goldfish_tty_write_room,
+	.chars_in_buffer = goldfish_tty_chars_in_buffer,
+};
+
+static int goldfish_tty_create_driver(void)
+{
+	int ret;
+	struct tty_driver *tty;
+
+	goldfish_ttys = kcalloc(goldfish_tty_line_count,
+				sizeof(*goldfish_ttys),
+				GFP_KERNEL);
+	if (goldfish_ttys == NULL) {
+		ret = -ENOMEM;
+		goto err_alloc_goldfish_ttys_failed;
+	}
+	tty = tty_alloc_driver(goldfish_tty_line_count,
+			TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(tty)) {
+		ret = PTR_ERR(tty);
+		goto err_tty_alloc_driver_failed;
+	}
+	tty->driver_name = "goldfish";
+	tty->name = "ttyGF";
+	tty->type = TTY_DRIVER_TYPE_SERIAL;
+	tty->subtype = SERIAL_TYPE_NORMAL;
+	tty->init_termios = tty_std_termios;
+	tty_set_operations(tty, &goldfish_tty_ops);
+	ret = tty_register_driver(tty);
+	if (ret)
+		goto err_tty_register_driver_failed;
+
+	goldfish_tty_driver = tty;
+	return 0;
+
+err_tty_register_driver_failed:
+	tty_driver_kref_put(tty);
+err_tty_alloc_driver_failed:
+	kfree(goldfish_ttys);
+	goldfish_ttys = NULL;
+err_alloc_goldfish_ttys_failed:
+	return ret;
+}
+
+static void goldfish_tty_delete_driver(void)
+{
+	tty_unregister_driver(goldfish_tty_driver);
+	tty_driver_kref_put(goldfish_tty_driver);
+	goldfish_tty_driver = NULL;
+	kfree(goldfish_ttys);
+	goldfish_ttys = NULL;
+}
+
+static int goldfish_tty_probe(struct platform_device *pdev)
+{
+	struct goldfish_tty *qtty;
+	int ret = -ENODEV;
+	struct resource *r;
+	struct device *ttydev;
+	void __iomem *base;
+	int irq;
+	unsigned int line;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		pr_err("goldfish_tty: No MEM resource available!\n");
+		return -ENOMEM;
+	}
+
+	base = ioremap(r->start, 0x1000);
+	if (!base) {
+		pr_err("goldfish_tty: Unable to ioremap base!\n");
+		return -ENOMEM;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = irq;
+		goto err_unmap;
+	}
+
+	mutex_lock(&goldfish_tty_lock);
+
+	if (pdev->id == PLATFORM_DEVID_NONE)
+		line = goldfish_tty_current_line_count;
+	else
+		line = pdev->id;
+
+	if (line >= goldfish_tty_line_count) {
+		pr_err("goldfish_tty: Reached maximum tty number of %d.\n",
+		       goldfish_tty_current_line_count);
+		ret = -ENOMEM;
+		goto err_unlock;
+	}
+
+	if (goldfish_tty_current_line_count == 0) {
+		ret = goldfish_tty_create_driver();
+		if (ret)
+			goto err_unlock;
+	}
+	goldfish_tty_current_line_count++;
+
+	qtty = &goldfish_ttys[line];
+	spin_lock_init(&qtty->lock);
+	tty_port_init(&qtty->port);
+	qtty->port.ops = &goldfish_port_ops;
+	qtty->base = base;
+	qtty->irq = irq;
+	qtty->dev = &pdev->dev;
+
+	/*
+	 * Goldfish TTY device used by the Goldfish emulator
+	 * should identify itself with 0, forcing the driver
+	 * to use virtual addresses. Goldfish TTY device
+	 * on Ranchu emulator (qemu2) returns 1 here and
+	 * driver will use physical addresses.
+	 */
+	qtty->version = gf_ioread32(base + GOLDFISH_TTY_REG_VERSION);
+
+	/*
+	 * Goldfish TTY device on Ranchu emulator (qemu2)
+	 * will use DMA for read/write IO operations.
+	 */
+	if (qtty->version > 0) {
+		/*
+		 * Initialize dma_mask to 32-bits.
+		 */
+		if (!pdev->dev.dma_mask)
+			pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+		ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+		if (ret) {
+			dev_err(&pdev->dev, "No suitable DMA available.\n");
+			goto err_dec_line_count;
+		}
+	}
+
+	gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
+
+	ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
+			  "goldfish_tty", qtty);
+	if (ret) {
+		pr_err("goldfish_tty: No IRQ available!\n");
+		goto err_dec_line_count;
+	}
+
+	ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
+					  line, &pdev->dev);
+	if (IS_ERR(ttydev)) {
+		ret = PTR_ERR(ttydev);
+		goto err_tty_register_device_failed;
+	}
+
+	strcpy(qtty->console.name, "ttyGF");
+	qtty->console.write = goldfish_tty_console_write;
+	qtty->console.device = goldfish_tty_console_device;
+	qtty->console.setup = goldfish_tty_console_setup;
+	qtty->console.flags = CON_PRINTBUFFER;
+	qtty->console.index = line;
+	register_console(&qtty->console);
+	platform_set_drvdata(pdev, qtty);
+
+	mutex_unlock(&goldfish_tty_lock);
+	return 0;
+
+err_tty_register_device_failed:
+	free_irq(irq, qtty);
+err_dec_line_count:
+	tty_port_destroy(&qtty->port);
+	goldfish_tty_current_line_count--;
+	if (goldfish_tty_current_line_count == 0)
+		goldfish_tty_delete_driver();
+err_unlock:
+	mutex_unlock(&goldfish_tty_lock);
+err_unmap:
+	iounmap(base);
+	return ret;
+}
+
+static int goldfish_tty_remove(struct platform_device *pdev)
+{
+	struct goldfish_tty *qtty = platform_get_drvdata(pdev);
+
+	mutex_lock(&goldfish_tty_lock);
+
+	unregister_console(&qtty->console);
+	tty_unregister_device(goldfish_tty_driver, qtty->console.index);
+	iounmap(qtty->base);
+	qtty->base = NULL;
+	free_irq(qtty->irq, qtty);
+	tty_port_destroy(&qtty->port);
+	goldfish_tty_current_line_count--;
+	if (goldfish_tty_current_line_count == 0)
+		goldfish_tty_delete_driver();
+	mutex_unlock(&goldfish_tty_lock);
+	return 0;
+}
+
+#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
+static void gf_early_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	gf_iowrite32(ch, port->membase);
+}
+
+static void gf_early_write(struct console *con, const char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, gf_early_console_putchar);
+}
+
+static int __init gf_earlycon_setup(struct earlycon_device *device,
+				    const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = gf_early_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
+#endif
+
+static const struct of_device_id goldfish_tty_of_match[] = {
+	{ .compatible = "google,goldfish-tty", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
+
+static struct platform_driver goldfish_tty_platform_driver = {
+	.probe = goldfish_tty_probe,
+	.remove = goldfish_tty_remove,
+	.driver = {
+		.name = "goldfish_tty",
+		.of_match_table = goldfish_tty_of_match,
+	}
+};
+
+module_platform_driver(goldfish_tty_platform_driver);
+
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
new file mode 100644
index 000000000..4f9264d00
--- /dev/null
+++ b/drivers/tty/hvc/Kconfig
@@ -0,0 +1,134 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config HVC_DRIVER
+	bool
+	help
+	  Generic "hypervisor virtual console" infrastructure for various
+	  hypervisors (pSeries, iSeries, Xen).
+	  It will automatically be selected if one of the back-end console drivers
+	  is selected.
+
+config HVC_IRQ
+	bool
+
+config HVC_CONSOLE
+	bool "pSeries Hypervisor Virtual Console support"
+	depends on PPC_PSERIES
+	select HVC_DRIVER
+	select HVC_IRQ
+	help
+	  pSeries machines when partitioned support a hypervisor virtual
+	  console. This driver allows each pSeries partition to have a console
+	  which is accessed via the HMC.
+
+config HVC_OLD_HVSI
+	bool "Old driver for pSeries serial port (/dev/hvsi*)"
+	depends on HVC_CONSOLE
+
+config HVC_OPAL
+	bool "OPAL Console support"
+	depends on PPC_POWERNV
+	select HVC_DRIVER
+	select HVC_IRQ
+	default y
+	help
+	  PowerNV machines running under OPAL need that driver to get a console
+
+config HVC_RTAS
+	bool "IBM RTAS Console support"
+	depends on PPC_RTAS
+	select HVC_DRIVER
+	help
+	  IBM Console device driver which makes use of RTAS
+
+config HVC_IUCV
+	bool "z/VM IUCV Hypervisor console support (VM only)"
+	depends on S390 && NET
+	select HVC_DRIVER
+	select IUCV
+	default y
+	help
+	  This driver provides a Hypervisor console (HVC) back-end to access
+	  a Linux (console) terminal via a z/VM IUCV communication path.
+
+config HVC_XEN
+	bool "Xen Hypervisor Console support"
+	depends on XEN
+	select HVC_DRIVER
+	select HVC_IRQ
+	default y
+	help
+	  Xen virtual console device driver
+
+config HVC_XEN_FRONTEND
+	bool "Xen Hypervisor Multiple Consoles support"
+	depends on HVC_XEN
+	select XEN_XENBUS_FRONTEND
+	default y
+	help
+	  Xen driver for secondary virtual consoles
+
+config HVC_UDBG
+	bool "udbg based fake hypervisor console"
+	depends on PPC
+	select HVC_DRIVER
+	help
+	  This is meant to be used during HW bring up or debugging when
+	  no other console mechanism exist but udbg, to get you a quick
+	  console for userspace. Do NOT enable in production kernels.
+
+config HVC_DCC
+	bool "ARM JTAG DCC console"
+	depends on ARM || ARM64
+	select HVC_DRIVER
+	select SERIAL_CORE_CONSOLE
+	help
+	  This console uses the JTAG DCC on ARM to create a console under the HVC
+	  driver. This console is used through a JTAG only on ARM. If you don't have
+	  a JTAG then you probably don't want this option.
+
+config HVC_DCC_SERIALIZE_SMP
+	bool "Use DCC only on CPU core 0"
+	depends on SMP && HVC_DCC
+	help
+	  This is a DEBUG option to serialize all console input and output to CPU 0.
+	  Some external debuggers, do not handle reads/writes from/to DCC on more
+	  than one CPU core. Each core has its own DCC device registers, so when a
+	  CPU core reads or writes from/to DCC, it only accesses its own DCC device.
+	  Since kernel code can run on any CPU core, every time the kernel wants to
+	  write to the console, it might write to a different DCC.
+
+	  In SMP mode, external debuggers create multiple windows, and each window
+	  shows the DCC output only from that core's DCC. The result is that
+	  console output is either lost or scattered across windows.
+
+	  Enable this option only if you are sure that you do not need features like
+	  CPU hotplug to work. For example, during early chipset bringups without
+	  debug serial console support. If unsure, say N.
+
+config HVC_RISCV_SBI
+	bool "RISC-V SBI console support"
+	depends on RISCV_SBI_V01
+	select HVC_DRIVER
+	help
+	  This enables support for console output via RISC-V SBI calls, which
+	  is normally used only during boot to output printk.
+
+	  If you don't know what do to here, say Y.
+
+config HVCS
+	tristate "IBM Hypervisor Virtual Console Server support"
+	depends on PPC_PSERIES && HVC_CONSOLE
+	help
+	  Partitionable IBM Power5 ppc64 machines allow hosting of
+	  firmware virtual consoles from one Linux partition by
+	  another Linux partition.  This driver allows console data
+	  from Linux partitions to be accessed through TTY device
+	  interfaces in the device tree of a Linux partition running
+	  this driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hvcs.  Additionally, this module
+	  will depend on arch specific APIs exported from hvcserver.ko
+	  which will also be compiled when this driver is built as a
+	  module.
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile
new file mode 100644
index 000000000..98880e357
--- /dev/null
+++ b/drivers/tty/hvc/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_HVC_CONSOLE)	+= hvc_vio.o hvsi_lib.o
+obj-$(CONFIG_HVC_OPAL)		+= hvc_opal.o hvsi_lib.o
+obj-$(CONFIG_HVC_OLD_HVSI)	+= hvsi.o
+obj-$(CONFIG_HVC_RTAS)		+= hvc_rtas.o
+obj-$(CONFIG_HVC_DCC)		+= hvc_dcc.o
+obj-$(CONFIG_HVC_DRIVER)	+= hvc_console.o
+obj-$(CONFIG_HVC_IRQ)		+= hvc_irq.o
+obj-$(CONFIG_HVC_XEN)		+= hvc_xen.o
+obj-$(CONFIG_HVC_IUCV)		+= hvc_iucv.o
+obj-$(CONFIG_HVC_UDBG)		+= hvc_udbg.o
+obj-$(CONFIG_HVC_RISCV_SBI)	+= hvc_riscv_sbi.o
+obj-$(CONFIG_HVCS)		+= hvcs.o
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
new file mode 100644
index 000000000..959fae54c
--- /dev/null
+++ b/drivers/tty/hvc/hvc_console.c
@@ -0,0 +1,1069 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ *  Ryan S. Arnold <rsa@us.ibm.com>
+ */
+
+#include <linux/console.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/kbd_kern.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/major.h>
+#include <linux/atomic.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/slab.h>
+#include <linux/serial_core.h>
+
+#include <linux/uaccess.h>
+
+#include "hvc_console.h"
+
+#define HVC_MAJOR	229
+#define HVC_MINOR	0
+
+/*
+ * Wait this long per iteration while trying to push buffered data to the
+ * hypervisor before allowing the tty to complete a close operation.
+ */
+#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
+
+/*
+ * These sizes are most efficient for vio, because they are the
+ * native transfer size. We could make them selectable in the
+ * future to better deal with backends that want other buffer sizes.
+ */
+#define N_OUTBUF	16
+#define N_INBUF		16
+
+#define __ALIGNED__ __attribute__((__aligned__(L1_CACHE_BYTES)))
+
+static struct tty_driver *hvc_driver;
+static struct task_struct *hvc_task;
+
+/* Picks up late kicks after list walk but before schedule() */
+static int hvc_kicked;
+
+/* hvc_init is triggered from hvc_alloc, i.e. only when actually used */
+static atomic_t hvc_needs_init __read_mostly = ATOMIC_INIT(-1);
+
+static int hvc_init(void);
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static int sysrq_pressed;
+#endif
+
+/* dynamic list of hvc_struct instances */
+static LIST_HEAD(hvc_structs);
+
+/*
+ * Protect the list of hvc_struct instances from inserts and removals during
+ * list traversal.
+ */
+static DEFINE_MUTEX(hvc_structs_mutex);
+
+/*
+ * This value is used to assign a tty->index value to a hvc_struct based
+ * upon order of exposure via hvc_probe(), when we can not match it to
+ * a console candidate registered with hvc_instantiate().
+ */
+static int last_hvc = -1;
+
+/*
+ * Do not call this function with either the hvc_structs_mutex or the hvc_struct
+ * lock held.  If successful, this function increments the kref reference
+ * count against the target hvc_struct so it should be released when finished.
+ */
+static struct hvc_struct *hvc_get_by_index(int index)
+{
+	struct hvc_struct *hp;
+	unsigned long flags;
+
+	mutex_lock(&hvc_structs_mutex);
+
+	list_for_each_entry(hp, &hvc_structs, next) {
+		spin_lock_irqsave(&hp->lock, flags);
+		if (hp->index == index) {
+			tty_port_get(&hp->port);
+			spin_unlock_irqrestore(&hp->lock, flags);
+			mutex_unlock(&hvc_structs_mutex);
+			return hp;
+		}
+		spin_unlock_irqrestore(&hp->lock, flags);
+	}
+	hp = NULL;
+	mutex_unlock(&hvc_structs_mutex);
+
+	return hp;
+}
+
+static int __hvc_flush(const struct hv_ops *ops, uint32_t vtermno, bool wait)
+{
+	if (wait)
+		might_sleep();
+
+	if (ops->flush)
+		return ops->flush(vtermno, wait);
+	return 0;
+}
+
+static int hvc_console_flush(const struct hv_ops *ops, uint32_t vtermno)
+{
+	return __hvc_flush(ops, vtermno, false);
+}
+
+/*
+ * Wait for the console to flush before writing more to it. This sleeps.
+ */
+static int hvc_flush(struct hvc_struct *hp)
+{
+	return __hvc_flush(hp->ops, hp->vtermno, true);
+}
+
+/*
+ * Initial console vtermnos for console API usage prior to full console
+ * initialization.  Any vty adapter outside this range will not have usable
+ * console interfaces but can still be used as a tty device.  This has to be
+ * static because kmalloc will not work during early console init.
+ */
+static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
+static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
+	{[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
+
+/*
+ * Console APIs, NOT TTY.  These APIs are available immediately when
+ * hvc_console_setup() finds adapters.
+ */
+
+static void hvc_console_print(struct console *co, const char *b,
+			      unsigned count)
+{
+	char c[N_OUTBUF] __ALIGNED__;
+	unsigned i = 0, n = 0;
+	int r, donecr = 0, index = co->index;
+
+	/* Console access attempt outside of acceptable console range. */
+	if (index >= MAX_NR_HVC_CONSOLES)
+		return;
+
+	/* This console adapter was removed so it is not usable. */
+	if (vtermnos[index] == -1)
+		return;
+
+	while (count > 0 || i > 0) {
+		if (count > 0 && i < sizeof(c)) {
+			if (b[n] == '\n' && !donecr) {
+				c[i++] = '\r';
+				donecr = 1;
+			} else {
+				c[i++] = b[n++];
+				donecr = 0;
+				--count;
+			}
+		} else {
+			r = cons_ops[index]->put_chars(vtermnos[index], c, i);
+			if (r <= 0) {
+				/* throw away characters on error
+				 * but spin in case of -EAGAIN */
+				if (r != -EAGAIN) {
+					i = 0;
+				} else {
+					hvc_console_flush(cons_ops[index],
+						      vtermnos[index]);
+				}
+			} else if (r > 0) {
+				i -= r;
+				if (i > 0)
+					memmove(c, c+r, i);
+			}
+		}
+	}
+	hvc_console_flush(cons_ops[index], vtermnos[index]);
+}
+
+static struct tty_driver *hvc_console_device(struct console *c, int *index)
+{
+	if (vtermnos[c->index] == -1)
+		return NULL;
+
+	*index = c->index;
+	return hvc_driver;
+}
+
+static int hvc_console_setup(struct console *co, char *options)
+{	
+	if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES)
+		return -ENODEV;
+
+	if (vtermnos[co->index] == -1)
+		return -ENODEV;
+
+	return 0;
+}
+
+static struct console hvc_console = {
+	.name		= "hvc",
+	.write		= hvc_console_print,
+	.device		= hvc_console_device,
+	.setup		= hvc_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+
+/*
+ * Early console initialization.  Precedes driver initialization.
+ *
+ * (1) we are first, and the user specified another driver
+ * -- index will remain -1
+ * (2) we are first and the user specified no driver
+ * -- index will be set to 0, then we will fail setup.
+ * (3)  we are first and the user specified our driver
+ * -- index will be set to user specified driver, and we will fail
+ * (4) we are after driver, and this initcall will register us
+ * -- if the user didn't specify a driver then the console will match
+ *
+ * Note that for cases 2 and 3, we will match later when the io driver
+ * calls hvc_instantiate() and call register again.
+ */
+static int __init hvc_console_init(void)
+{
+	register_console(&hvc_console);
+	return 0;
+}
+console_initcall(hvc_console_init);
+
+/* callback when the kboject ref count reaches zero. */
+static void hvc_port_destruct(struct tty_port *port)
+{
+	struct hvc_struct *hp = container_of(port, struct hvc_struct, port);
+	unsigned long flags;
+
+	mutex_lock(&hvc_structs_mutex);
+
+	spin_lock_irqsave(&hp->lock, flags);
+	list_del(&(hp->next));
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+	mutex_unlock(&hvc_structs_mutex);
+
+	kfree(hp);
+}
+
+static void hvc_check_console(int index)
+{
+	/* Already registered, bail out */
+	if (console_is_registered(&hvc_console))
+		return;
+
+ 	/* If this index is what the user requested, then register
+	 * now (setup won't fail at this point).  It's ok to just
+	 * call register again if previously .setup failed.
+	 */
+	if (index == hvc_console.index)
+		register_console(&hvc_console);
+}
+
+/*
+ * hvc_instantiate() is an early console discovery method which locates
+ * consoles * prior to the vio subsystem discovering them.  Hotplugged
+ * vty adapters do NOT get an hvc_instantiate() callback since they
+ * appear after early console init.
+ */
+int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops)
+{
+	struct hvc_struct *hp;
+
+	if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
+		return -1;
+
+	if (vtermnos[index] != -1)
+		return -1;
+
+	/* make sure no tty has been registered in this index */
+	hp = hvc_get_by_index(index);
+	if (hp) {
+		tty_port_put(&hp->port);
+		return -1;
+	}
+
+	vtermnos[index] = vtermno;
+	cons_ops[index] = ops;
+
+	/* check if we need to re-register the kernel console */
+	hvc_check_console(index);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hvc_instantiate);
+
+/* Wake the sleeping khvcd */
+void hvc_kick(void)
+{
+	hvc_kicked = 1;
+	wake_up_process(hvc_task);
+}
+EXPORT_SYMBOL_GPL(hvc_kick);
+
+static void hvc_unthrottle(struct tty_struct *tty)
+{
+	hvc_kick();
+}
+
+static int hvc_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct hvc_struct *hp;
+	int rc;
+
+	/* Auto increments kref reference if found. */
+	hp = hvc_get_by_index(tty->index);
+	if (!hp)
+		return -ENODEV;
+
+	tty->driver_data = hp;
+
+	rc = tty_port_install(&hp->port, driver, tty);
+	if (rc)
+		tty_port_put(&hp->port);
+	return rc;
+}
+
+/*
+ * The TTY interface won't be used until after the vio layer has exposed the vty
+ * adapter to the kernel.
+ */
+static int hvc_open(struct tty_struct *tty, struct file * filp)
+{
+	struct hvc_struct *hp = tty->driver_data;
+	unsigned long flags;
+	int rc = 0;
+
+	spin_lock_irqsave(&hp->port.lock, flags);
+	/* Check and then increment for fast path open. */
+	if (hp->port.count++ > 0) {
+		spin_unlock_irqrestore(&hp->port.lock, flags);
+		hvc_kick();
+		return 0;
+	} /* else count == 0 */
+	spin_unlock_irqrestore(&hp->port.lock, flags);
+
+	tty_port_tty_set(&hp->port, tty);
+
+	if (hp->ops->notifier_add)
+		rc = hp->ops->notifier_add(hp, hp->data);
+
+	/*
+	 * If the notifier fails we return an error.  The tty layer
+	 * will call hvc_close() after a failed open but we don't want to clean
+	 * up there so we'll clean up here and clear out the previously set
+	 * tty fields and return the kref reference.
+	 */
+	if (rc) {
+		printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
+	} else {
+		/* We are ready... raise DTR/RTS */
+		if (C_BAUD(tty))
+			if (hp->ops->dtr_rts)
+				hp->ops->dtr_rts(hp, true);
+		tty_port_set_initialized(&hp->port, true);
+	}
+
+	/* Force wakeup of the polling thread */
+	hvc_kick();
+
+	return rc;
+}
+
+static void hvc_close(struct tty_struct *tty, struct file * filp)
+{
+	struct hvc_struct *hp = tty->driver_data;
+	unsigned long flags;
+
+	if (tty_hung_up_p(filp))
+		return;
+
+	spin_lock_irqsave(&hp->port.lock, flags);
+
+	if (--hp->port.count == 0) {
+		spin_unlock_irqrestore(&hp->port.lock, flags);
+		/* We are done with the tty pointer now. */
+		tty_port_tty_set(&hp->port, NULL);
+
+		if (!tty_port_initialized(&hp->port))
+			return;
+
+		if (C_HUPCL(tty))
+			if (hp->ops->dtr_rts)
+				hp->ops->dtr_rts(hp, false);
+
+		if (hp->ops->notifier_del)
+			hp->ops->notifier_del(hp, hp->data);
+
+		/* cancel pending tty resize work */
+		cancel_work_sync(&hp->tty_resize);
+
+		/*
+		 * Chain calls chars_in_buffer() and returns immediately if
+		 * there is no buffered data otherwise sleeps on a wait queue
+		 * waking periodically to check chars_in_buffer().
+		 */
+		tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
+		tty_port_set_initialized(&hp->port, false);
+	} else {
+		if (hp->port.count < 0)
+			printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
+				hp->vtermno, hp->port.count);
+		spin_unlock_irqrestore(&hp->port.lock, flags);
+	}
+}
+
+static void hvc_cleanup(struct tty_struct *tty)
+{
+	struct hvc_struct *hp = tty->driver_data;
+
+	tty_port_put(&hp->port);
+}
+
+static void hvc_hangup(struct tty_struct *tty)
+{
+	struct hvc_struct *hp = tty->driver_data;
+	unsigned long flags;
+
+	if (!hp)
+		return;
+
+	/* cancel pending tty resize work */
+	cancel_work_sync(&hp->tty_resize);
+
+	spin_lock_irqsave(&hp->port.lock, flags);
+
+	/*
+	 * The N_TTY line discipline has problems such that in a close vs
+	 * open->hangup case this can be called after the final close so prevent
+	 * that from happening for now.
+	 */
+	if (hp->port.count <= 0) {
+		spin_unlock_irqrestore(&hp->port.lock, flags);
+		return;
+	}
+
+	hp->port.count = 0;
+	spin_unlock_irqrestore(&hp->port.lock, flags);
+	tty_port_tty_set(&hp->port, NULL);
+
+	hp->n_outbuf = 0;
+
+	if (hp->ops->notifier_hangup)
+		hp->ops->notifier_hangup(hp, hp->data);
+}
+
+/*
+ * Push buffered characters whether they were just recently buffered or waiting
+ * on a blocked hypervisor.  Call this function with hp->lock held.
+ */
+static int hvc_push(struct hvc_struct *hp)
+{
+	int n;
+
+	n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
+	if (n <= 0) {
+		if (n == 0 || n == -EAGAIN) {
+			hp->do_wakeup = 1;
+			return 0;
+		}
+		/* throw away output on error; this happens when
+		   there is no session connected to the vterm. */
+		hp->n_outbuf = 0;
+	} else
+		hp->n_outbuf -= n;
+	if (hp->n_outbuf > 0)
+		memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);
+	else
+		hp->do_wakeup = 1;
+
+	return n;
+}
+
+static ssize_t hvc_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct hvc_struct *hp = tty->driver_data;
+	unsigned long flags;
+	size_t rsize, written = 0;
+
+	/* This write was probably executed during a tty close. */
+	if (!hp)
+		return -EPIPE;
+
+	/* FIXME what's this (unprotected) check for? */
+	if (hp->port.count <= 0)
+		return -EIO;
+
+	while (count > 0) {
+		int ret = 0;
+
+		spin_lock_irqsave(&hp->lock, flags);
+
+		rsize = hp->outbuf_size - hp->n_outbuf;
+
+		if (rsize) {
+			if (rsize > count)
+				rsize = count;
+			memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
+			count -= rsize;
+			buf += rsize;
+			hp->n_outbuf += rsize;
+			written += rsize;
+		}
+
+		if (hp->n_outbuf > 0)
+			ret = hvc_push(hp);
+
+		spin_unlock_irqrestore(&hp->lock, flags);
+
+		if (!ret)
+			break;
+
+		if (count) {
+			if (hp->n_outbuf > 0)
+				hvc_flush(hp);
+			cond_resched();
+		}
+	}
+
+	/*
+	 * Racy, but harmless, kick thread if there is still pending data.
+	 */
+	if (hp->n_outbuf)
+		hvc_kick();
+
+	return written;
+}
+
+/**
+ * hvc_set_winsz() - Resize the hvc tty terminal window.
+ * @work:	work structure.
+ *
+ * The routine shall not be called within an atomic context because it
+ * might sleep.
+ *
+ * Locking:	hp->lock
+ */
+static void hvc_set_winsz(struct work_struct *work)
+{
+	struct hvc_struct *hp;
+	unsigned long hvc_flags;
+	struct tty_struct *tty;
+	struct winsize ws;
+
+	hp = container_of(work, struct hvc_struct, tty_resize);
+
+	tty = tty_port_tty_get(&hp->port);
+	if (!tty)
+		return;
+
+	spin_lock_irqsave(&hp->lock, hvc_flags);
+	ws = hp->ws;
+	spin_unlock_irqrestore(&hp->lock, hvc_flags);
+
+	tty_do_resize(tty, &ws);
+	tty_kref_put(tty);
+}
+
+/*
+ * This is actually a contract between the driver and the tty layer outlining
+ * how much write room the driver can guarantee will be sent OR BUFFERED.  This
+ * driver MUST honor the return value.
+ */
+static unsigned int hvc_write_room(struct tty_struct *tty)
+{
+	struct hvc_struct *hp = tty->driver_data;
+
+	if (!hp)
+		return 0;
+
+	return hp->outbuf_size - hp->n_outbuf;
+}
+
+static unsigned int hvc_chars_in_buffer(struct tty_struct *tty)
+{
+	struct hvc_struct *hp = tty->driver_data;
+
+	if (!hp)
+		return 0;
+	return hp->n_outbuf;
+}
+
+/*
+ * timeout will vary between the MIN and MAX values defined here.  By default
+ * and during console activity we will use a default MIN_TIMEOUT of 10.  When
+ * the console is idle, we increase the timeout value on each pass through
+ * msleep until we reach the max.  This may be noticeable as a brief (average
+ * one second) delay on the console before the console responds to input when
+ * there has been no input for some time.
+ */
+#define MIN_TIMEOUT		(10)
+#define MAX_TIMEOUT		(2000)
+static u32 timeout = MIN_TIMEOUT;
+
+/*
+ * Maximum number of bytes to get from the console driver if hvc_poll is
+ * called from driver (and can't sleep). Any more than this and we break
+ * and start polling with khvcd. This value was derived from an OpenBMC
+ * console with the OPAL driver that results in about 0.25ms interrupts off
+ * latency.
+ */
+#define HVC_ATOMIC_READ_MAX	128
+
+#define HVC_POLL_READ	0x00000001
+#define HVC_POLL_WRITE	0x00000002
+
+static int __hvc_poll(struct hvc_struct *hp, bool may_sleep)
+{
+	struct tty_struct *tty;
+	int i, n, count, poll_mask = 0;
+	char buf[N_INBUF] __ALIGNED__;
+	unsigned long flags;
+	int read_total = 0;
+	int written_total = 0;
+
+	spin_lock_irqsave(&hp->lock, flags);
+
+	/* Push pending writes */
+	if (hp->n_outbuf > 0)
+		written_total = hvc_push(hp);
+
+	/* Reschedule us if still some write pending */
+	if (hp->n_outbuf > 0) {
+		poll_mask |= HVC_POLL_WRITE;
+		/* If hvc_push() was not able to write, sleep a few msecs */
+		timeout = (written_total) ? 0 : MIN_TIMEOUT;
+	}
+
+	if (may_sleep) {
+		spin_unlock_irqrestore(&hp->lock, flags);
+		cond_resched();
+		spin_lock_irqsave(&hp->lock, flags);
+	}
+
+	/* No tty attached, just skip */
+	tty = tty_port_tty_get(&hp->port);
+	if (tty == NULL)
+		goto bail;
+
+	/* Now check if we can get data (are we throttled ?) */
+	if (tty_throttled(tty))
+		goto out;
+
+	/* If we aren't notifier driven and aren't throttled, we always
+	 * request a reschedule
+	 */
+	if (!hp->irq_requested)
+		poll_mask |= HVC_POLL_READ;
+
+ read_again:
+	/* Read data if any */
+	count = tty_buffer_request_room(&hp->port, N_INBUF);
+
+	/* If flip is full, just reschedule a later read */
+	if (count == 0) {
+		poll_mask |= HVC_POLL_READ;
+		goto out;
+	}
+
+	n = hp->ops->get_chars(hp->vtermno, buf, count);
+	if (n <= 0) {
+		/* Hangup the tty when disconnected from host */
+		if (n == -EPIPE) {
+			spin_unlock_irqrestore(&hp->lock, flags);
+			tty_hangup(tty);
+			spin_lock_irqsave(&hp->lock, flags);
+		} else if ( n == -EAGAIN ) {
+			/*
+			 * Some back-ends can only ensure a certain min
+			 * num of bytes read, which may be > 'count'.
+			 * Let the tty clear the flip buff to make room.
+			 */
+			poll_mask |= HVC_POLL_READ;
+		}
+		goto out;
+	}
+
+	for (i = 0; i < n; ++i) {
+#ifdef CONFIG_MAGIC_SYSRQ
+		if (hp->index == hvc_console.index) {
+			/* Handle the SysRq Hack */
+			/* XXX should support a sequence */
+			if (buf[i] == '\x0f') {	/* ^O */
+				/* if ^O is pressed again, reset
+				 * sysrq_pressed and flip ^O char */
+				sysrq_pressed = !sysrq_pressed;
+				if (sysrq_pressed)
+					continue;
+			} else if (sysrq_pressed) {
+				handle_sysrq(buf[i]);
+				sysrq_pressed = 0;
+				continue;
+			}
+		}
+#endif /* CONFIG_MAGIC_SYSRQ */
+		tty_insert_flip_char(&hp->port, buf[i], 0);
+	}
+	read_total += n;
+
+	if (may_sleep) {
+		/* Keep going until the flip is full */
+		spin_unlock_irqrestore(&hp->lock, flags);
+		cond_resched();
+		spin_lock_irqsave(&hp->lock, flags);
+		goto read_again;
+	} else if (read_total < HVC_ATOMIC_READ_MAX) {
+		/* Break and defer if it's a large read in atomic */
+		goto read_again;
+	}
+
+	/*
+	 * Latency break, schedule another poll immediately.
+	 */
+	poll_mask |= HVC_POLL_READ;
+
+ out:
+	/* Wakeup write queue if necessary */
+	if (hp->do_wakeup) {
+		hp->do_wakeup = 0;
+		tty_wakeup(tty);
+	}
+ bail:
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+	if (read_total) {
+		/* Activity is occurring, so reset the polling backoff value to
+		   a minimum for performance. */
+		timeout = MIN_TIMEOUT;
+
+		tty_flip_buffer_push(&hp->port);
+	}
+	tty_kref_put(tty);
+
+	return poll_mask;
+}
+
+int hvc_poll(struct hvc_struct *hp)
+{
+	return __hvc_poll(hp, false);
+}
+EXPORT_SYMBOL_GPL(hvc_poll);
+
+/**
+ * __hvc_resize() - Update terminal window size information.
+ * @hp:		HVC console pointer
+ * @ws:		Terminal window size structure
+ *
+ * Stores the specified window size information in the hvc structure of @hp.
+ * The function schedule the tty resize update.
+ *
+ * Locking:	Locking free; the function MUST be called holding hp->lock
+ */
+void __hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+	hp->ws = ws;
+	schedule_work(&hp->tty_resize);
+}
+EXPORT_SYMBOL_GPL(__hvc_resize);
+
+/*
+ * This kthread is either polling or interrupt driven.  This is determined by
+ * calling hvc_poll() who determines whether a console adapter support
+ * interrupts.
+ */
+static int khvcd(void *unused)
+{
+	int poll_mask;
+	struct hvc_struct *hp;
+
+	set_freezable();
+	do {
+		poll_mask = 0;
+		hvc_kicked = 0;
+		try_to_freeze();
+		wmb();
+		if (!cpus_are_in_xmon()) {
+			mutex_lock(&hvc_structs_mutex);
+			list_for_each_entry(hp, &hvc_structs, next) {
+				poll_mask |= __hvc_poll(hp, true);
+				cond_resched();
+			}
+			mutex_unlock(&hvc_structs_mutex);
+		} else
+			poll_mask |= HVC_POLL_READ;
+		if (hvc_kicked)
+			continue;
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!hvc_kicked) {
+			if (poll_mask == 0)
+				schedule();
+			else {
+				unsigned long j_timeout;
+
+				if (timeout < MAX_TIMEOUT)
+					timeout += (timeout >> 6) + 1;
+
+				/*
+				 * We don't use msleep_interruptible otherwise
+				 * "kick" will fail to wake us up
+				 */
+				j_timeout = msecs_to_jiffies(timeout) + 1;
+				schedule_timeout_interruptible(j_timeout);
+			}
+		}
+		__set_current_state(TASK_RUNNING);
+	} while (!kthread_should_stop());
+
+	return 0;
+}
+
+static int hvc_tiocmget(struct tty_struct *tty)
+{
+	struct hvc_struct *hp = tty->driver_data;
+
+	if (!hp || !hp->ops->tiocmget)
+		return -EINVAL;
+	return hp->ops->tiocmget(hp);
+}
+
+static int hvc_tiocmset(struct tty_struct *tty,
+			unsigned int set, unsigned int clear)
+{
+	struct hvc_struct *hp = tty->driver_data;
+
+	if (!hp || !hp->ops->tiocmset)
+		return -EINVAL;
+	return hp->ops->tiocmset(hp, set, clear);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int hvc_poll_init(struct tty_driver *driver, int line, char *options)
+{
+	return 0;
+}
+
+static int hvc_poll_get_char(struct tty_driver *driver, int line)
+{
+	struct tty_struct *tty = driver->ttys[0];
+	struct hvc_struct *hp = tty->driver_data;
+	int n;
+	char ch;
+
+	n = hp->ops->get_chars(hp->vtermno, &ch, 1);
+
+	if (n <= 0)
+		return NO_POLL_CHAR;
+
+	return ch;
+}
+
+static void hvc_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+	struct tty_struct *tty = driver->ttys[0];
+	struct hvc_struct *hp = tty->driver_data;
+	int n;
+
+	do {
+		n = hp->ops->put_chars(hp->vtermno, &ch, 1);
+	} while (n <= 0);
+}
+#endif
+
+static const struct tty_operations hvc_ops = {
+	.install = hvc_install,
+	.open = hvc_open,
+	.close = hvc_close,
+	.cleanup = hvc_cleanup,
+	.write = hvc_write,
+	.hangup = hvc_hangup,
+	.unthrottle = hvc_unthrottle,
+	.write_room = hvc_write_room,
+	.chars_in_buffer = hvc_chars_in_buffer,
+	.tiocmget = hvc_tiocmget,
+	.tiocmset = hvc_tiocmset,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init = hvc_poll_init,
+	.poll_get_char = hvc_poll_get_char,
+	.poll_put_char = hvc_poll_put_char,
+#endif
+};
+
+static const struct tty_port_operations hvc_port_ops = {
+	.destruct = hvc_port_destruct,
+};
+
+struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
+			     const struct hv_ops *ops,
+			     int outbuf_size)
+{
+	struct hvc_struct *hp;
+	int i;
+
+	/* We wait until a driver actually comes along */
+	if (atomic_inc_not_zero(&hvc_needs_init)) {
+		int err = hvc_init();
+		if (err)
+			return ERR_PTR(err);
+	}
+
+	hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
+			GFP_KERNEL);
+	if (!hp)
+		return ERR_PTR(-ENOMEM);
+
+	hp->vtermno = vtermno;
+	hp->data = data;
+	hp->ops = ops;
+	hp->outbuf_size = outbuf_size;
+	hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))];
+
+	tty_port_init(&hp->port);
+	hp->port.ops = &hvc_port_ops;
+
+	INIT_WORK(&hp->tty_resize, hvc_set_winsz);
+	spin_lock_init(&hp->lock);
+	mutex_lock(&hvc_structs_mutex);
+
+	/*
+	 * find index to use:
+	 * see if this vterm id matches one registered for console.
+	 */
+	for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
+		if (vtermnos[i] == hp->vtermno &&
+		    cons_ops[i] == hp->ops)
+			break;
+
+	if (i >= MAX_NR_HVC_CONSOLES) {
+
+		/* find 'empty' slot for console */
+		for (i = 0; i < MAX_NR_HVC_CONSOLES && vtermnos[i] != -1; i++) {
+		}
+
+		/* no matching slot, just use a counter */
+		if (i == MAX_NR_HVC_CONSOLES)
+			i = ++last_hvc + MAX_NR_HVC_CONSOLES;
+	}
+
+	hp->index = i;
+	if (i < MAX_NR_HVC_CONSOLES) {
+		cons_ops[i] = ops;
+		vtermnos[i] = vtermno;
+	}
+
+	list_add_tail(&(hp->next), &hvc_structs);
+	mutex_unlock(&hvc_structs_mutex);
+
+	/* check if we need to re-register the kernel console */
+	hvc_check_console(i);
+
+	return hp;
+}
+EXPORT_SYMBOL_GPL(hvc_alloc);
+
+int hvc_remove(struct hvc_struct *hp)
+{
+	unsigned long flags;
+	struct tty_struct *tty;
+
+	tty = tty_port_tty_get(&hp->port);
+
+	console_lock();
+	spin_lock_irqsave(&hp->lock, flags);
+	if (hp->index < MAX_NR_HVC_CONSOLES) {
+		vtermnos[hp->index] = -1;
+		cons_ops[hp->index] = NULL;
+	}
+
+	/* Don't whack hp->irq because tty_hangup() will need to free the irq. */
+
+	spin_unlock_irqrestore(&hp->lock, flags);
+	console_unlock();
+
+	/*
+	 * We 'put' the instance that was grabbed when the kref instance
+	 * was initialized using kref_init().  Let the last holder of this
+	 * kref cause it to be removed, which will probably be the tty_vhangup
+	 * below.
+	 */
+	tty_port_put(&hp->port);
+
+	/*
+	 * This function call will auto chain call hvc_hangup.
+	 */
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hvc_remove);
+
+/* Driver initialization: called as soon as someone uses hvc_alloc(). */
+static int hvc_init(void)
+{
+	struct tty_driver *drv;
+	int err;
+
+	/* We need more than hvc_count adapters due to hotplug additions. */
+	drv = tty_alloc_driver(HVC_ALLOC_TTY_ADAPTERS, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_RESET_TERMIOS);
+	if (IS_ERR(drv)) {
+		err = PTR_ERR(drv);
+		goto out;
+	}
+
+	drv->driver_name = "hvc";
+	drv->name = "hvc";
+	drv->major = HVC_MAJOR;
+	drv->minor_start = HVC_MINOR;
+	drv->type = TTY_DRIVER_TYPE_SYSTEM;
+	drv->init_termios = tty_std_termios;
+	tty_set_operations(drv, &hvc_ops);
+
+	/* Always start the kthread because there can be hotplug vty adapters
+	 * added later. */
+	hvc_task = kthread_run(khvcd, NULL, "khvcd");
+	if (IS_ERR(hvc_task)) {
+		printk(KERN_ERR "Couldn't create kthread for console.\n");
+		err = PTR_ERR(hvc_task);
+		goto put_tty;
+	}
+
+	err = tty_register_driver(drv);
+	if (err) {
+		printk(KERN_ERR "Couldn't register hvc console driver\n");
+		goto stop_thread;
+	}
+
+	/*
+	 * Make sure tty is fully registered before allowing it to be
+	 * found by hvc_console_device.
+	 */
+	smp_mb();
+	hvc_driver = drv;
+	return 0;
+
+stop_thread:
+	kthread_stop(hvc_task);
+	hvc_task = NULL;
+put_tty:
+	tty_driver_kref_put(drv);
+out:
+	return err;
+}
diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h
new file mode 100644
index 000000000..9668f821d
--- /dev/null
+++ b/drivers/tty/hvc/hvc_console.h
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * hvc_console.h
+ * Copyright (C) 2005 IBM Corporation
+ *
+ * Author(s):
+ * 	Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * hvc_console header information:
+ *      moved here from arch/powerpc/include/asm/hvconsole.h
+ *      and drivers/char/hvc_console.c
+ */
+
+#ifndef HVC_CONSOLE_H
+#define HVC_CONSOLE_H
+#include <linux/kref.h>
+#include <linux/tty.h>
+#include <linux/spinlock.h>
+
+/*
+ * This is the max number of console adapters that can/will be found as
+ * console devices on first stage console init.  Any number beyond this range
+ * can't be used as a console device but is still a valid tty device.
+ */
+#define MAX_NR_HVC_CONSOLES	16
+
+/*
+ * The Linux TTY code does not support dynamic addition of tty derived devices
+ * so we need to know how many tty devices we might need when space is allocated
+ * for the tty device.  Since this driver supports hotplug of vty adapters we
+ * need to make sure we have enough allocated.
+ */
+#define HVC_ALLOC_TTY_ADAPTERS	8
+
+struct hvc_struct {
+	struct tty_port port;
+	spinlock_t lock;
+	int index;
+	int do_wakeup;
+	char *outbuf;
+	int outbuf_size;
+	int n_outbuf;
+	uint32_t vtermno;
+	const struct hv_ops *ops;
+	int irq_requested;
+	int data;
+	struct winsize ws;
+	struct work_struct tty_resize;
+	struct list_head next;
+	unsigned long flags;
+};
+
+/* implemented by a low level driver */
+struct hv_ops {
+	int (*get_chars)(uint32_t vtermno, char *buf, int count);
+	int (*put_chars)(uint32_t vtermno, const char *buf, int count);
+	int (*flush)(uint32_t vtermno, bool wait);
+
+	/* Callbacks for notification. Called in open, close and hangup */
+	int (*notifier_add)(struct hvc_struct *hp, int irq);
+	void (*notifier_del)(struct hvc_struct *hp, int irq);
+	void (*notifier_hangup)(struct hvc_struct *hp, int irq);
+
+	/* tiocmget/set implementation */
+	int (*tiocmget)(struct hvc_struct *hp);
+	int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
+
+	/* Callbacks to handle tty ports */
+	void (*dtr_rts)(struct hvc_struct *hp, bool active);
+};
+
+/* Register a vterm and a slot index for use as a console (console_init) */
+extern int hvc_instantiate(uint32_t vtermno, int index,
+			   const struct hv_ops *ops);
+
+/* register a vterm for hvc tty operation (module_init or hotplug add) */
+extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
+				     const struct hv_ops *ops, int outbuf_size);
+/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
+extern int hvc_remove(struct hvc_struct *hp);
+
+/* data available */
+int hvc_poll(struct hvc_struct *hp);
+void hvc_kick(void);
+
+/* Resize hvc tty terminal window */
+extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
+
+static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&hp->lock, flags);
+	__hvc_resize(hp, ws);
+	spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+/* default notifier for irq based notification */
+extern int notifier_add_irq(struct hvc_struct *hp, int data);
+extern void notifier_del_irq(struct hvc_struct *hp, int data);
+extern void notifier_hangup_irq(struct hvc_struct *hp, int data);
+
+
+#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
+#include <asm/xmon.h>
+#else
+static inline int cpus_are_in_xmon(void)
+{
+	return 0;
+}
+#endif
+
+#endif // HVC_CONSOLE_H
diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
new file mode 100644
index 000000000..1751108cf
--- /dev/null
+++ b/drivers/tty/hvc/hvc_dcc.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2010, 2014, 2022 The Linux Foundation. All rights reserved.  */
+
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/kfifo.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+
+#include <asm/dcc.h>
+#include <asm/processor.h>
+
+#include "hvc_console.h"
+
+/* DCC Status Bits */
+#define DCC_STATUS_RX		(1 << 30)
+#define DCC_STATUS_TX		(1 << 29)
+
+#define DCC_INBUF_SIZE		128
+#define DCC_OUTBUF_SIZE		1024
+
+/* Lock to serialize access to DCC fifo */
+static DEFINE_SPINLOCK(dcc_lock);
+
+static DEFINE_KFIFO(inbuf, unsigned char, DCC_INBUF_SIZE);
+static DEFINE_KFIFO(outbuf, unsigned char, DCC_OUTBUF_SIZE);
+
+static void dcc_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (__dcc_getstatus() & DCC_STATUS_TX)
+		cpu_relax();
+
+	__dcc_putchar(ch);
+}
+
+static void dcc_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, dcc_uart_console_putchar);
+}
+
+static int __init dcc_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	device->con->write = dcc_early_write;
+
+	return 0;
+}
+
+EARLYCON_DECLARE(dcc, dcc_early_console_setup);
+
+static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		while (__dcc_getstatus() & DCC_STATUS_TX)
+			cpu_relax();
+
+		__dcc_putchar(buf[i]);
+	}
+
+	return count;
+}
+
+static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count)
+{
+	int i;
+
+	for (i = 0; i < count; ++i)
+		if (__dcc_getstatus() & DCC_STATUS_RX)
+			buf[i] = __dcc_getchar();
+		else
+			break;
+
+	return i;
+}
+
+/*
+ * Check if the DCC is enabled. If CONFIG_HVC_DCC_SERIALIZE_SMP is enabled,
+ * then we assume then this function will be called first on core0. That way,
+ * dcc_core0_available will be true only if it's available on core0.
+ */
+static bool hvc_dcc_check(void)
+{
+	unsigned long time = jiffies + (HZ / 10);
+	static bool dcc_core0_available;
+
+	/*
+	 * If we're not on core 0, but we previously confirmed that DCC is
+	 * active, then just return true.
+	 */
+	int cpu = get_cpu();
+
+	if (IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP) && cpu && dcc_core0_available) {
+		put_cpu();
+		return true;
+	}
+
+	put_cpu();
+
+	/* Write a test character to check if it is handled */
+	__dcc_putchar('\n');
+
+	while (time_is_after_jiffies(time)) {
+		if (!(__dcc_getstatus() & DCC_STATUS_TX)) {
+			dcc_core0_available = true;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/*
+ * Workqueue function that writes the output FIFO to the DCC on core 0.
+ */
+static void dcc_put_work(struct work_struct *work)
+{
+	unsigned char ch;
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&dcc_lock, irqflags);
+
+	/* While there's data in the output FIFO, write it to the DCC */
+	while (kfifo_get(&outbuf, &ch))
+		hvc_dcc_put_chars(0, &ch, 1);
+
+	/* While we're at it, check for any input characters */
+	while (!kfifo_is_full(&inbuf)) {
+		if (!hvc_dcc_get_chars(0, &ch, 1))
+			break;
+		kfifo_put(&inbuf, ch);
+	}
+
+	spin_unlock_irqrestore(&dcc_lock, irqflags);
+}
+
+static DECLARE_WORK(dcc_pwork, dcc_put_work);
+
+/*
+ * Workqueue function that reads characters from DCC and puts them into the
+ * input FIFO.
+ */
+static void dcc_get_work(struct work_struct *work)
+{
+	unsigned char ch;
+	unsigned long irqflags;
+
+	/*
+	 * Read characters from DCC and put them into the input FIFO, as
+	 * long as there is room and we have characters to read.
+	 */
+	spin_lock_irqsave(&dcc_lock, irqflags);
+
+	while (!kfifo_is_full(&inbuf)) {
+		if (!hvc_dcc_get_chars(0, &ch, 1))
+			break;
+		kfifo_put(&inbuf, ch);
+	}
+	spin_unlock_irqrestore(&dcc_lock, irqflags);
+}
+
+static DECLARE_WORK(dcc_gwork, dcc_get_work);
+
+/*
+ * Write characters directly to the DCC if we're on core 0 and the FIFO
+ * is empty, or write them to the FIFO if we're not.
+ */
+static int hvc_dcc0_put_chars(u32 vt, const char *buf, int count)
+{
+	int len;
+	unsigned long irqflags;
+
+	if (!IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP))
+		return hvc_dcc_put_chars(vt, buf, count);
+
+	spin_lock_irqsave(&dcc_lock, irqflags);
+	if (smp_processor_id() || (!kfifo_is_empty(&outbuf))) {
+		len = kfifo_in(&outbuf, buf, count);
+		spin_unlock_irqrestore(&dcc_lock, irqflags);
+
+		/*
+		 * We just push data to the output FIFO, so schedule the
+		 * workqueue that will actually write that data to DCC.
+		 * CPU hotplug is disabled in dcc_init so CPU0 cannot be
+		 * offlined after the cpu online check.
+		 */
+		if (cpu_online(0))
+			schedule_work_on(0, &dcc_pwork);
+
+		return len;
+	}
+
+	/*
+	 * If we're already on core 0, and the FIFO is empty, then just
+	 * write the data to DCC.
+	 */
+	len = hvc_dcc_put_chars(vt, buf, count);
+	spin_unlock_irqrestore(&dcc_lock, irqflags);
+
+	return len;
+}
+
+/*
+ * Read characters directly from the DCC if we're on core 0 and the FIFO
+ * is empty, or read them from the FIFO if we're not.
+ */
+static int hvc_dcc0_get_chars(u32 vt, char *buf, int count)
+{
+	int len;
+	unsigned long irqflags;
+
+	if (!IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP))
+		return hvc_dcc_get_chars(vt, buf, count);
+
+	spin_lock_irqsave(&dcc_lock, irqflags);
+
+	if (smp_processor_id() || (!kfifo_is_empty(&inbuf))) {
+		len = kfifo_out(&inbuf, buf, count);
+		spin_unlock_irqrestore(&dcc_lock, irqflags);
+
+		/*
+		 * If the FIFO was empty, there may be characters in the DCC
+		 * that we haven't read yet.  Schedule a workqueue to fill
+		 * the input FIFO, so that the next time this function is
+		 * called, we'll have data. CPU hotplug is disabled in dcc_init
+		 * so CPU0 cannot be offlined after the cpu online check.
+		 */
+		if (!len && cpu_online(0))
+			schedule_work_on(0, &dcc_gwork);
+
+		return len;
+	}
+
+	/*
+	 * If we're already on core 0, and the FIFO is empty, then just
+	 * read the data from DCC.
+	 */
+	len = hvc_dcc_get_chars(vt, buf, count);
+	spin_unlock_irqrestore(&dcc_lock, irqflags);
+
+	return len;
+}
+
+static const struct hv_ops hvc_dcc_get_put_ops = {
+	.get_chars = hvc_dcc0_get_chars,
+	.put_chars = hvc_dcc0_put_chars,
+};
+
+static int __init hvc_dcc_console_init(void)
+{
+	int ret;
+
+	if (!hvc_dcc_check())
+		return -ENODEV;
+
+	/* Returns -1 if error */
+	ret = hvc_instantiate(0, 0, &hvc_dcc_get_put_ops);
+
+	return ret < 0 ? -ENODEV : 0;
+}
+console_initcall(hvc_dcc_console_init);
+
+static int __init hvc_dcc_init(void)
+{
+	struct hvc_struct *p;
+
+	if (!hvc_dcc_check())
+		return -ENODEV;
+
+	if (IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP)) {
+		pr_warn("\n");
+		pr_warn("********************************************************************\n");
+		pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
+		pr_warn("**                                                                **\n");
+		pr_warn("**  HVC_DCC_SERIALIZE_SMP SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
+		pr_warn("**                                                                **\n");
+		pr_warn("** This means that this is a DEBUG kernel and unsafe for          **\n");
+		pr_warn("** production use and has important feature like CPU hotplug      **\n");
+		pr_warn("** disabled.                                                      **\n");
+		pr_warn("**                                                                **\n");
+		pr_warn("** If you see this message and you are not debugging the          **\n");
+		pr_warn("** kernel, report this immediately to your vendor!                **\n");
+		pr_warn("**                                                                **\n");
+		pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
+		pr_warn("********************************************************************\n");
+
+		cpu_hotplug_disable();
+	}
+
+	p = hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128);
+
+	return PTR_ERR_OR_ZERO(p);
+}
+device_initcall(hvc_dcc_init);
diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c
new file mode 100644
index 000000000..4b255dfef
--- /dev/null
+++ b/drivers/tty/hvc/hvc_irq.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2001,2008
+ *
+ * This file contains the IRQ specific code for hvc_console
+ *
+ */
+
+#include <linux/interrupt.h>
+
+#include "hvc_console.h"
+
+static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
+{
+	/* if hvc_poll request a repoll, then kick the hvcd thread */
+	if (hvc_poll(dev_instance))
+		hvc_kick();
+
+	/*
+	 * We're safe to always return IRQ_HANDLED as the hvcd thread will
+	 * iterate through each hvc_struct.
+	 */
+	return IRQ_HANDLED;
+}
+
+/*
+ * For IRQ based systems these callbacks can be used
+ */
+int notifier_add_irq(struct hvc_struct *hp, int irq)
+{
+	int rc;
+
+	if (!irq) {
+		hp->irq_requested = 0;
+		return 0;
+	}
+	rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
+			"hvc_console", hp);
+	if (!rc)
+		hp->irq_requested = 1;
+	return rc;
+}
+
+void notifier_del_irq(struct hvc_struct *hp, int irq)
+{
+	if (!hp->irq_requested)
+		return;
+	free_irq(irq, hp);
+	hp->irq_requested = 0;
+}
+
+void notifier_hangup_irq(struct hvc_struct *hp, int irq)
+{
+	notifier_del_irq(hp, irq);
+}
diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
new file mode 100644
index 000000000..543f35ddf
--- /dev/null
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -0,0 +1,1427 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * z/VM IUCV hypervisor console (HVC) device driver
+ *
+ * This HVC device driver provides terminal access using
+ * z/VM IUCV communication paths.
+ *
+ * Copyright IBM Corp. 2008, 2013
+ *
+ * Author(s):	Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ */
+#define KMSG_COMPONENT		"hvc_iucv"
+#define pr_fmt(fmt)		KMSG_COMPONENT ": " fmt
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <asm/ebcdic.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/mempool.h>
+#include <linux/moduleparam.h>
+#include <linux/tty.h>
+#include <linux/wait.h>
+#include <net/iucv/iucv.h>
+
+#include "hvc_console.h"
+
+
+/* General device driver settings */
+#define MAX_HVC_IUCV_LINES	HVC_ALLOC_TTY_ADAPTERS
+#define MEMPOOL_MIN_NR		(PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4)
+
+/* IUCV TTY message  */
+#define MSG_VERSION		0x02	/* Message version */
+#define MSG_TYPE_ERROR		0x01	/* Error message */
+#define MSG_TYPE_TERMENV	0x02	/* Terminal environment variable */
+#define MSG_TYPE_TERMIOS	0x04	/* Terminal IO struct update */
+#define MSG_TYPE_WINSIZE	0x08	/* Terminal window size update */
+#define MSG_TYPE_DATA		0x10	/* Terminal data */
+
+struct iucv_tty_msg {
+	u8	version;		/* Message version */
+	u8	type;			/* Message type */
+#define MSG_MAX_DATALEN		((u16)(~0))
+	u16	datalen;		/* Payload length */
+	u8	data[];			/* Payload buffer */
+} __attribute__((packed));
+#define MSG_SIZE(s)		((s) + offsetof(struct iucv_tty_msg, data))
+
+enum iucv_state_t {
+	IUCV_DISCONN	= 0,
+	IUCV_CONNECTED	= 1,
+	IUCV_SEVERED	= 2,
+};
+
+enum tty_state_t {
+	TTY_CLOSED	= 0,
+	TTY_OPENED	= 1,
+};
+
+struct hvc_iucv_private {
+	struct hvc_struct	*hvc;		/* HVC struct reference */
+	u8			srv_name[8];	/* IUCV service name (ebcdic) */
+	unsigned char		is_console;	/* Linux console usage flag */
+	enum iucv_state_t	iucv_state;	/* IUCV connection status */
+	enum tty_state_t	tty_state;	/* TTY status */
+	struct iucv_path	*path;		/* IUCV path pointer */
+	spinlock_t		lock;		/* hvc_iucv_private lock */
+#define SNDBUF_SIZE		(PAGE_SIZE)	/* must be < MSG_MAX_DATALEN */
+	void			*sndbuf;	/* send buffer		  */
+	size_t			sndbuf_len;	/* length of send buffer  */
+#define QUEUE_SNDBUF_DELAY	(HZ / 25)
+	struct delayed_work	sndbuf_work;	/* work: send iucv msg(s) */
+	wait_queue_head_t	sndbuf_waitq;	/* wait for send completion */
+	struct list_head	tty_outqueue;	/* outgoing IUCV messages */
+	struct list_head	tty_inqueue;	/* incoming IUCV messages */
+	struct device		*dev;		/* device structure */
+	u8			info_path[16];	/* IUCV path info (dev attr) */
+};
+
+struct iucv_tty_buffer {
+	struct list_head	list;	/* list pointer */
+	struct iucv_message	msg;	/* store an IUCV message */
+	size_t			offset;	/* data buffer offset */
+	struct iucv_tty_msg	*mbuf;	/* buffer to store input/output data */
+};
+
+/* IUCV callback handler */
+static	int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *);
+static void hvc_iucv_path_severed(struct iucv_path *, u8 *);
+static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *);
+static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *);
+
+
+/* Kernel module parameter: use one terminal device as default */
+static unsigned long hvc_iucv_devices = 1;
+
+/* Array of allocated hvc iucv tty lines... */
+static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];
+#define IUCV_HVC_CON_IDX	(0)
+/* List of z/VM user ID filter entries (struct iucv_vmid_filter) */
+#define MAX_VMID_FILTER		(500)
+#define FILTER_WILDCARD_CHAR	'*'
+static size_t hvc_iucv_filter_size;
+static void *hvc_iucv_filter;
+static const char *hvc_iucv_filter_string;
+static DEFINE_RWLOCK(hvc_iucv_filter_lock);
+
+/* Kmem cache and mempool for iucv_tty_buffer elements */
+static struct kmem_cache *hvc_iucv_buffer_cache;
+static mempool_t *hvc_iucv_mempool;
+
+/* IUCV handler callback functions */
+static struct iucv_handler hvc_iucv_handler = {
+	.path_pending  = hvc_iucv_path_pending,
+	.path_severed  = hvc_iucv_path_severed,
+	.message_complete = hvc_iucv_msg_complete,
+	.message_pending  = hvc_iucv_msg_pending,
+};
+
+
+/**
+ * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance.
+ * @num:	The HVC virtual terminal number (vtermno)
+ *
+ * This function returns the struct hvc_iucv_private instance that corresponds
+ * to the HVC virtual terminal number specified as parameter @num.
+ */
+static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
+{
+	if (num > hvc_iucv_devices)
+		return NULL;
+	return hvc_iucv_table[num];
+}
+
+/**
+ * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element.
+ * @size:	Size of the internal buffer used to store data.
+ * @flags:	Memory allocation flags passed to mempool.
+ *
+ * This function allocates a new struct iucv_tty_buffer element and, optionally,
+ * allocates an internal data buffer with the specified size @size.
+ * The internal data buffer is always allocated with GFP_DMA which is
+ * required for receiving and sending data with IUCV.
+ * Note: The total message size arises from the internal buffer size and the
+ *	 members of the iucv_tty_msg structure.
+ * The function returns NULL if memory allocation has failed.
+ */
+static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags)
+{
+	struct iucv_tty_buffer *bufp;
+
+	bufp = mempool_alloc(hvc_iucv_mempool, flags);
+	if (!bufp)
+		return NULL;
+	memset(bufp, 0, sizeof(*bufp));
+
+	if (size > 0) {
+		bufp->msg.length = MSG_SIZE(size);
+		bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA);
+		if (!bufp->mbuf) {
+			mempool_free(bufp, hvc_iucv_mempool);
+			return NULL;
+		}
+		bufp->mbuf->version = MSG_VERSION;
+		bufp->mbuf->type    = MSG_TYPE_DATA;
+		bufp->mbuf->datalen = (u16) size;
+	}
+	return bufp;
+}
+
+/**
+ * destroy_tty_buffer() - destroy struct iucv_tty_buffer element.
+ * @bufp:	Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL.
+ */
+static void destroy_tty_buffer(struct iucv_tty_buffer *bufp)
+{
+	kfree(bufp->mbuf);
+	mempool_free(bufp, hvc_iucv_mempool);
+}
+
+/**
+ * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element.
+ * @list:	List containing struct iucv_tty_buffer elements.
+ */
+static void destroy_tty_buffer_list(struct list_head *list)
+{
+	struct iucv_tty_buffer *ent, *next;
+
+	list_for_each_entry_safe(ent, next, list, list) {
+		list_del(&ent->list);
+		destroy_tty_buffer(ent);
+	}
+}
+
+/**
+ * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer.
+ * @priv:		Pointer to struct hvc_iucv_private
+ * @buf:		HVC buffer for writing received terminal data.
+ * @count:		HVC buffer size.
+ * @has_more_data:	Pointer to an int variable.
+ *
+ * The function picks up pending messages from the input queue and receives
+ * the message data that is then written to the specified buffer @buf.
+ * If the buffer size @count is less than the data message size, the
+ * message is kept on the input queue and @has_more_data is set to 1.
+ * If all message data has been written, the message is removed from
+ * the input queue.
+ *
+ * The function returns the number of bytes written to the terminal, zero if
+ * there are no pending data messages available or if there is no established
+ * IUCV path.
+ * If the IUCV path has been severed, then -EPIPE is returned to cause a
+ * hang up (that is issued by the HVC layer).
+ */
+static int hvc_iucv_write(struct hvc_iucv_private *priv,
+			  char *buf, int count, int *has_more_data)
+{
+	struct iucv_tty_buffer *rb;
+	int written;
+	int rc;
+
+	/* immediately return if there is no IUCV connection */
+	if (priv->iucv_state == IUCV_DISCONN)
+		return 0;
+
+	/* if the IUCV path has been severed, return -EPIPE to inform the
+	 * HVC layer to hang up the tty device. */
+	if (priv->iucv_state == IUCV_SEVERED)
+		return -EPIPE;
+
+	/* check if there are pending messages */
+	if (list_empty(&priv->tty_inqueue))
+		return 0;
+
+	/* receive an iucv message and flip data to the tty (ldisc) */
+	rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list);
+
+	written = 0;
+	if (!rb->mbuf) { /* message not yet received ... */
+		/* allocate mem to store msg data; if no memory is available
+		 * then leave the buffer on the list and re-try later */
+		rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA);
+		if (!rb->mbuf)
+			return -ENOMEM;
+
+		rc = __iucv_message_receive(priv->path, &rb->msg, 0,
+					    rb->mbuf, rb->msg.length, NULL);
+		switch (rc) {
+		case 0: /* Successful	    */
+			break;
+		case 2:	/* No message found */
+		case 9: /* Message purged   */
+			break;
+		default:
+			written = -EIO;
+		}
+		/* remove buffer if an error has occurred or received data
+		 * is not correct */
+		if (rc || (rb->mbuf->version != MSG_VERSION) ||
+			  (rb->msg.length    != MSG_SIZE(rb->mbuf->datalen)))
+			goto out_remove_buffer;
+	}
+
+	switch (rb->mbuf->type) {
+	case MSG_TYPE_DATA:
+		written = min_t(int, rb->mbuf->datalen - rb->offset, count);
+		memcpy(buf, rb->mbuf->data + rb->offset, written);
+		if (written < (rb->mbuf->datalen - rb->offset)) {
+			rb->offset += written;
+			*has_more_data = 1;
+			goto out_written;
+		}
+		break;
+
+	case MSG_TYPE_WINSIZE:
+		if (rb->mbuf->datalen != sizeof(struct winsize))
+			break;
+		/* The caller must ensure that the hvc is locked, which
+		 * is the case when called from hvc_iucv_get_chars() */
+		__hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
+		break;
+
+	case MSG_TYPE_ERROR:	/* ignored ... */
+	case MSG_TYPE_TERMENV:	/* ignored ... */
+	case MSG_TYPE_TERMIOS:	/* ignored ... */
+		break;
+	}
+
+out_remove_buffer:
+	list_del(&rb->list);
+	destroy_tty_buffer(rb);
+	*has_more_data = !list_empty(&priv->tty_inqueue);
+
+out_written:
+	return written;
+}
+
+/**
+ * hvc_iucv_get_chars() - HVC get_chars operation.
+ * @vtermno:	HVC virtual terminal number.
+ * @buf:	Pointer to a buffer to store data
+ * @count:	Size of buffer available for writing
+ *
+ * The HVC thread calls this method to read characters from the back-end.
+ * If an IUCV communication path has been established, pending IUCV messages
+ * are received and data is copied into buffer @buf up to @count bytes.
+ *
+ * Locking:	The routine gets called under an irqsave() spinlock; and
+ *		the routine locks the struct hvc_iucv_private->lock to call
+ *		helper functions.
+ */
+static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
+	int written;
+	int has_more_data;
+
+	if (count <= 0)
+		return 0;
+
+	if (!priv)
+		return -ENODEV;
+
+	spin_lock(&priv->lock);
+	has_more_data = 0;
+	written = hvc_iucv_write(priv, buf, count, &has_more_data);
+	spin_unlock(&priv->lock);
+
+	/* if there are still messages on the queue... schedule another run */
+	if (has_more_data)
+		hvc_kick();
+
+	return written;
+}
+
+/**
+ * hvc_iucv_queue() - Buffer terminal data for sending.
+ * @priv:	Pointer to struct hvc_iucv_private instance.
+ * @buf:	Buffer containing data to send.
+ * @count:	Size of buffer and amount of data to send.
+ *
+ * The function queues data for sending. To actually send the buffered data,
+ * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY).
+ * The function returns the number of data bytes that has been buffered.
+ *
+ * If the device is not connected, data is ignored and the function returns
+ * @count.
+ * If the buffer is full, the function returns 0.
+ * If an existing IUCV communicaton path has been severed, -EPIPE is returned
+ * (that can be passed to HVC layer to cause a tty hangup).
+ */
+static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf,
+			  int count)
+{
+	size_t len;
+
+	if (priv->iucv_state == IUCV_DISCONN)
+		return count;			/* ignore data */
+
+	if (priv->iucv_state == IUCV_SEVERED)
+		return -EPIPE;
+
+	len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len);
+	if (!len)
+		return 0;
+
+	memcpy(priv->sndbuf + priv->sndbuf_len, buf, len);
+	priv->sndbuf_len += len;
+
+	if (priv->iucv_state == IUCV_CONNECTED)
+		schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY);
+
+	return len;
+}
+
+/**
+ * hvc_iucv_send() - Send an IUCV message containing terminal data.
+ * @priv:	Pointer to struct hvc_iucv_private instance.
+ *
+ * If an IUCV communication path has been established, the buffered output data
+ * is sent via an IUCV message and the number of bytes sent is returned.
+ * Returns 0 if there is no established IUCV communication path or
+ * -EPIPE if an existing IUCV communicaton path has been severed.
+ */
+static int hvc_iucv_send(struct hvc_iucv_private *priv)
+{
+	struct iucv_tty_buffer *sb;
+	int rc, len;
+
+	if (priv->iucv_state == IUCV_SEVERED)
+		return -EPIPE;
+
+	if (priv->iucv_state == IUCV_DISCONN)
+		return -EIO;
+
+	if (!priv->sndbuf_len)
+		return 0;
+
+	/* allocate internal buffer to store msg data and also compute total
+	 * message length */
+	sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC);
+	if (!sb)
+		return -ENOMEM;
+
+	memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len);
+	sb->mbuf->datalen = (u16) priv->sndbuf_len;
+	sb->msg.length = MSG_SIZE(sb->mbuf->datalen);
+
+	list_add_tail(&sb->list, &priv->tty_outqueue);
+
+	rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
+				 (void *) sb->mbuf, sb->msg.length);
+	if (rc) {
+		/* drop the message here; however we might want to handle
+		 * 0x03 (msg limit reached) by trying again... */
+		list_del(&sb->list);
+		destroy_tty_buffer(sb);
+	}
+	len = priv->sndbuf_len;
+	priv->sndbuf_len = 0;
+
+	return len;
+}
+
+/**
+ * hvc_iucv_sndbuf_work() - Send buffered data over IUCV
+ * @work:	Work structure.
+ *
+ * This work queue function sends buffered output data over IUCV and,
+ * if not all buffered data could be sent, reschedules itself.
+ */
+static void hvc_iucv_sndbuf_work(struct work_struct *work)
+{
+	struct hvc_iucv_private *priv;
+
+	priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);
+
+	spin_lock_bh(&priv->lock);
+	hvc_iucv_send(priv);
+	spin_unlock_bh(&priv->lock);
+}
+
+/**
+ * hvc_iucv_put_chars() - HVC put_chars operation.
+ * @vtermno:	HVC virtual terminal number.
+ * @buf:	Pointer to an buffer to read data from
+ * @count:	Size of buffer available for reading
+ *
+ * The HVC thread calls this method to write characters to the back-end.
+ * The function calls hvc_iucv_queue() to queue terminal data for sending.
+ *
+ * Locking:	The method gets called under an irqsave() spinlock; and
+ *		locks struct hvc_iucv_private->lock.
+ */
+static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
+	int queued;
+
+	if (count <= 0)
+		return 0;
+
+	if (!priv)
+		return -ENODEV;
+
+	spin_lock(&priv->lock);
+	queued = hvc_iucv_queue(priv, buf, count);
+	spin_unlock(&priv->lock);
+
+	return queued;
+}
+
+/**
+ * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.
+ * @hp:	Pointer to the HVC device (struct hvc_struct)
+ * @id:	Additional data (originally passed to hvc_alloc): the index of an struct
+ *	hvc_iucv_private instance.
+ *
+ * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private
+ * instance that is derived from @id. Always returns 0.
+ *
+ * Locking:	struct hvc_iucv_private->lock, spin_lock_bh
+ */
+static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)
+{
+	struct hvc_iucv_private *priv;
+
+	priv = hvc_iucv_get_private(id);
+	if (!priv)
+		return 0;
+
+	spin_lock_bh(&priv->lock);
+	priv->tty_state = TTY_OPENED;
+	spin_unlock_bh(&priv->lock);
+
+	return 0;
+}
+
+/**
+ * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.
+ * @priv:	Pointer to the struct hvc_iucv_private instance.
+ */
+static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
+{
+	destroy_tty_buffer_list(&priv->tty_outqueue);
+	destroy_tty_buffer_list(&priv->tty_inqueue);
+
+	priv->tty_state = TTY_CLOSED;
+	priv->iucv_state = IUCV_DISCONN;
+
+	priv->sndbuf_len = 0;
+}
+
+/**
+ * tty_outqueue_empty() - Test if the tty outq is empty
+ * @priv:	Pointer to struct hvc_iucv_private instance.
+ */
+static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)
+{
+	int rc;
+
+	spin_lock_bh(&priv->lock);
+	rc = list_empty(&priv->tty_outqueue);
+	spin_unlock_bh(&priv->lock);
+
+	return rc;
+}
+
+/**
+ * flush_sndbuf_sync() - Flush send buffer and wait for completion
+ * @priv:	Pointer to struct hvc_iucv_private instance.
+ *
+ * The routine cancels a pending sndbuf work, calls hvc_iucv_send()
+ * to flush any buffered terminal output data and waits for completion.
+ */
+static void flush_sndbuf_sync(struct hvc_iucv_private *priv)
+{
+	int sync_wait;
+
+	cancel_delayed_work_sync(&priv->sndbuf_work);
+
+	spin_lock_bh(&priv->lock);
+	hvc_iucv_send(priv);		/* force sending buffered data */
+	sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */
+	spin_unlock_bh(&priv->lock);
+
+	if (sync_wait)
+		wait_event_timeout(priv->sndbuf_waitq,
+				   tty_outqueue_empty(priv), HZ/10);
+}
+
+/**
+ * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
+ * @priv:	Pointer to hvc_iucv_private structure
+ *
+ * This routine severs an existing IUCV communication path and hangs
+ * up the underlying HVC terminal device.
+ * The hang-up occurs only if an IUCV communication path is established;
+ * otherwise there is no need to hang up the terminal device.
+ *
+ * The IUCV HVC hang-up is separated into two steps:
+ * 1. After the IUCV path has been severed, the iucv_state is set to
+ *    IUCV_SEVERED.
+ * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
+ *    IUCV_SEVERED state causes the tty hang-up in the HVC layer.
+ *
+ * If the tty has not yet been opened, clean up the hvc_iucv_private
+ * structure to allow re-connects.
+ * If the tty has been opened, let get_chars() return -EPIPE to signal
+ * the HVC layer to hang up the tty and, if so, wake up the HVC thread
+ * to call get_chars()...
+ *
+ * Special notes on hanging up a HVC terminal instantiated as console:
+ * Hang-up:	1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
+ *		2. do_tty_hangup() calls tty->ops->close() for console_filp
+ *			=> no hangup notifier is called by HVC (default)
+ *		2. hvc_close() returns because of tty_hung_up_p(filp)
+ *			=> no delete notifier is called!
+ * Finally, the back-end is not being notified, thus, the tty session is
+ * kept active (TTY_OPEN) to be ready for re-connects.
+ *
+ * Locking:	spin_lock(&priv->lock) w/o disabling bh
+ */
+static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
+{
+	struct iucv_path *path;
+
+	path = NULL;
+	spin_lock(&priv->lock);
+	if (priv->iucv_state == IUCV_CONNECTED) {
+		path = priv->path;
+		priv->path = NULL;
+		priv->iucv_state = IUCV_SEVERED;
+		if (priv->tty_state == TTY_CLOSED)
+			hvc_iucv_cleanup(priv);
+		else
+			/* console is special (see above) */
+			if (priv->is_console) {
+				hvc_iucv_cleanup(priv);
+				priv->tty_state = TTY_OPENED;
+			} else
+				hvc_kick();
+	}
+	spin_unlock(&priv->lock);
+
+	/* finally sever path (outside of priv->lock due to lock ordering) */
+	if (path) {
+		iucv_path_sever(path, NULL);
+		iucv_path_free(path);
+	}
+}
+
+/**
+ * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.
+ * @hp:		Pointer to the HVC device (struct hvc_struct)
+ * @id:		Additional data (originally passed to hvc_alloc):
+ *		the index of an struct hvc_iucv_private instance.
+ *
+ * This routine notifies the HVC back-end that a tty hangup (carrier loss,
+ * virtual or otherwise) has occurred.
+ * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())
+ * to keep an existing IUCV communication path established.
+ * (Background: vhangup() is called from user space (by getty or login) to
+ *		disable writing to the tty by other applications).
+ * If the tty has been opened and an established IUCV path has been severed
+ * (we caused the tty hangup), the function calls hvc_iucv_cleanup().
+ *
+ * Locking:	struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
+{
+	struct hvc_iucv_private *priv;
+
+	priv = hvc_iucv_get_private(id);
+	if (!priv)
+		return;
+
+	flush_sndbuf_sync(priv);
+
+	spin_lock_bh(&priv->lock);
+	/* NOTE: If the hangup was scheduled by ourself (from the iucv
+	 *	 path_servered callback [IUCV_SEVERED]), we have to clean up
+	 *	 our structure and to set state to TTY_CLOSED.
+	 *	 If the tty was hung up otherwise (e.g. vhangup()), then we
+	 *	 ignore this hangup and keep an established IUCV path open...
+	 *	 (...the reason is that we are not able to connect back to the
+	 *	 client if we disconnect on hang up) */
+	priv->tty_state = TTY_CLOSED;
+
+	if (priv->iucv_state == IUCV_SEVERED)
+		hvc_iucv_cleanup(priv);
+	spin_unlock_bh(&priv->lock);
+}
+
+/**
+ * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS
+ * @hp:		Pointer the HVC device (struct hvc_struct)
+ * @active:	True to raise or false to lower DTR/RTS lines
+ *
+ * This routine notifies the HVC back-end to raise or lower DTR/RTS
+ * lines.  Raising DTR/RTS is ignored.  Lowering DTR/RTS indicates to
+ * drop the IUCV connection (similar to hang up the modem).
+ */
+static void hvc_iucv_dtr_rts(struct hvc_struct *hp, bool active)
+{
+	struct hvc_iucv_private *priv;
+	struct iucv_path        *path;
+
+	/* Raising the DTR/RTS is ignored as IUCV connections can be
+	 * established at any times.
+	 */
+	if (active)
+		return;
+
+	priv = hvc_iucv_get_private(hp->vtermno);
+	if (!priv)
+		return;
+
+	/* Lowering the DTR/RTS lines disconnects an established IUCV
+	 * connection.
+	 */
+	flush_sndbuf_sync(priv);
+
+	spin_lock_bh(&priv->lock);
+	path = priv->path;		/* save reference to IUCV path */
+	priv->path = NULL;
+	priv->iucv_state = IUCV_DISCONN;
+	spin_unlock_bh(&priv->lock);
+
+	/* Sever IUCV path outside of priv->lock due to lock ordering of:
+	 * priv->lock <--> iucv_table_lock */
+	if (path) {
+		iucv_path_sever(path, NULL);
+		iucv_path_free(path);
+	}
+}
+
+/**
+ * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
+ * @hp:		Pointer to the HVC device (struct hvc_struct)
+ * @id:		Additional data (originally passed to hvc_alloc):
+ *		the index of an struct hvc_iucv_private instance.
+ *
+ * This routine notifies the HVC back-end that the last tty device fd has been
+ * closed.  The function cleans up tty resources.  The clean-up of the IUCV
+ * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios
+ * control setting.
+ *
+ * Locking:	struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
+{
+	struct hvc_iucv_private *priv;
+
+	priv = hvc_iucv_get_private(id);
+	if (!priv)
+		return;
+
+	flush_sndbuf_sync(priv);
+
+	spin_lock_bh(&priv->lock);
+	destroy_tty_buffer_list(&priv->tty_outqueue);
+	destroy_tty_buffer_list(&priv->tty_inqueue);
+	priv->tty_state = TTY_CLOSED;
+	priv->sndbuf_len = 0;
+	spin_unlock_bh(&priv->lock);
+}
+
+/**
+ * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
+ * @ipvmid:	Originating z/VM user ID (right padded with blanks)
+ *
+ * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to
+ * connect, otherwise non-zero.
+ */
+static int hvc_iucv_filter_connreq(u8 ipvmid[8])
+{
+	const char *wildcard, *filter_entry;
+	size_t i, len;
+
+	/* Note: default policy is ACCEPT if no filter is set */
+	if (!hvc_iucv_filter_size)
+		return 0;
+
+	for (i = 0; i < hvc_iucv_filter_size; i++) {
+		filter_entry = hvc_iucv_filter + (8 * i);
+
+		/* If a filter entry contains the filter wildcard character,
+		 * reduce the length to match the leading portion of the user
+		 * ID only (wildcard match).  Characters following the wildcard
+		 * are ignored.
+		 */
+		wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR);
+		len = (wildcard) ? wildcard - filter_entry : 8;
+		if (0 == memcmp(ipvmid, filter_entry, len))
+			return 0;
+	}
+	return 1;
+}
+
+/**
+ * hvc_iucv_path_pending() - IUCV handler to process a connection request.
+ * @path:	Pending path (struct iucv_path)
+ * @ipvmid:	z/VM system identifier of originator
+ * @ipuser:	User specified data for this path
+ *		(AF_IUCV: port/service name and originator port)
+ *
+ * The function uses the @ipuser data to determine if the pending path belongs
+ * to a terminal managed by this device driver.
+ * If the path belongs to this driver, ensure that the terminal is not accessed
+ * multiple times (only one connection to a terminal is allowed).
+ * If the terminal is not yet connected, the pending path is accepted and is
+ * associated to the appropriate struct hvc_iucv_private instance.
+ *
+ * Returns 0 if @path belongs to a terminal managed by the this device driver;
+ * otherwise returns -ENODEV in order to dispatch this path to other handlers.
+ *
+ * Locking:	struct hvc_iucv_private->lock
+ */
+static	int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid,
+				  u8 *ipuser)
+{
+	struct hvc_iucv_private *priv, *tmp;
+	u8 wildcard[9] = "lnxhvc  ";
+	int i, rc, find_unused;
+	u8 nuser_data[16];
+	u8 vm_user_id[9];
+
+	ASCEBC(wildcard, sizeof(wildcard));
+	find_unused = !memcmp(wildcard, ipuser, 8);
+
+	/* First, check if the pending path request is managed by this
+	 * IUCV handler:
+	 * - find a disconnected device if ipuser contains the wildcard
+	 * - find the device that matches the terminal ID in ipuser
+	 */
+	priv = NULL;
+	for (i = 0; i < hvc_iucv_devices; i++) {
+		tmp = hvc_iucv_table[i];
+		if (!tmp)
+			continue;
+
+		if (find_unused) {
+			spin_lock(&tmp->lock);
+			if (tmp->iucv_state == IUCV_DISCONN)
+				priv = tmp;
+			spin_unlock(&tmp->lock);
+
+		} else if (!memcmp(tmp->srv_name, ipuser, 8))
+				priv = tmp;
+		if (priv)
+			break;
+	}
+	if (!priv)
+		return -ENODEV;
+
+	/* Enforce that ipvmid is allowed to connect to us */
+	read_lock(&hvc_iucv_filter_lock);
+	rc = hvc_iucv_filter_connreq(ipvmid);
+	read_unlock(&hvc_iucv_filter_lock);
+	if (rc) {
+		iucv_path_sever(path, ipuser);
+		iucv_path_free(path);
+		memcpy(vm_user_id, ipvmid, 8);
+		vm_user_id[8] = 0;
+		pr_info("A connection request from z/VM user ID %s "
+			"was refused\n", vm_user_id);
+		return 0;
+	}
+
+	spin_lock(&priv->lock);
+
+	/* If the terminal is already connected or being severed, then sever
+	 * this path to enforce that there is only ONE established communication
+	 * path per terminal. */
+	if (priv->iucv_state != IUCV_DISCONN) {
+		iucv_path_sever(path, ipuser);
+		iucv_path_free(path);
+		goto out_path_handled;
+	}
+
+	/* accept path */
+	memcpy(nuser_data, ipuser + 8, 8);  /* remote service (for af_iucv) */
+	memcpy(nuser_data + 8, ipuser, 8);  /* local service  (for af_iucv) */
+	path->msglim = 0xffff;		    /* IUCV MSGLIMIT */
+	path->flags &= ~IUCV_IPRMDATA;	    /* TODO: use IUCV_IPRMDATA */
+	rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);
+	if (rc) {
+		iucv_path_sever(path, ipuser);
+		iucv_path_free(path);
+		goto out_path_handled;
+	}
+	priv->path = path;
+	priv->iucv_state = IUCV_CONNECTED;
+
+	/* store path information */
+	memcpy(priv->info_path, ipvmid, 8);
+	memcpy(priv->info_path + 8, ipuser + 8, 8);
+
+	/* flush buffered output data... */
+	schedule_delayed_work(&priv->sndbuf_work, 5);
+
+out_path_handled:
+	spin_unlock(&priv->lock);
+	return 0;
+}
+
+/**
+ * hvc_iucv_path_severed() - IUCV handler to process a path sever.
+ * @path:	Pending path (struct iucv_path)
+ * @ipuser:	User specified data for this path
+ *		(AF_IUCV: port/service name and originator port)
+ *
+ * This function calls the hvc_iucv_hangup() function for the
+ * respective IUCV HVC terminal.
+ *
+ * Locking:	struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser)
+{
+	struct hvc_iucv_private *priv = path->private;
+
+	hvc_iucv_hangup(priv);
+}
+
+/**
+ * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.
+ * @path:	Pending path (struct iucv_path)
+ * @msg:	Pointer to the IUCV message
+ *
+ * The function puts an incoming message on the input queue for later
+ * processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
+ * If the tty has not yet been opened, the message is rejected.
+ *
+ * Locking:	struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_msg_pending(struct iucv_path *path,
+				 struct iucv_message *msg)
+{
+	struct hvc_iucv_private *priv = path->private;
+	struct iucv_tty_buffer *rb;
+
+	/* reject messages that exceed max size of iucv_tty_msg->datalen */
+	if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {
+		iucv_message_reject(path, msg);
+		return;
+	}
+
+	spin_lock(&priv->lock);
+
+	/* reject messages if tty has not yet been opened */
+	if (priv->tty_state == TTY_CLOSED) {
+		iucv_message_reject(path, msg);
+		goto unlock_return;
+	}
+
+	/* allocate tty buffer to save iucv msg only */
+	rb = alloc_tty_buffer(0, GFP_ATOMIC);
+	if (!rb) {
+		iucv_message_reject(path, msg);
+		goto unlock_return;	/* -ENOMEM */
+	}
+	rb->msg = *msg;
+
+	list_add_tail(&rb->list, &priv->tty_inqueue);
+
+	hvc_kick();	/* wake up hvc thread */
+
+unlock_return:
+	spin_unlock(&priv->lock);
+}
+
+/**
+ * hvc_iucv_msg_complete() - IUCV handler to process message completion
+ * @path:	Pending path (struct iucv_path)
+ * @msg:	Pointer to the IUCV message
+ *
+ * The function is called upon completion of message delivery to remove the
+ * message from the outqueue. Additional delivery information can be found
+ * msg->audit: rejected messages (0x040000 (IPADRJCT)), and
+ *	       purged messages	 (0x010000 (IPADPGNR)).
+ *
+ * Locking:	struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_msg_complete(struct iucv_path *path,
+				  struct iucv_message *msg)
+{
+	struct hvc_iucv_private *priv = path->private;
+	struct iucv_tty_buffer	*ent, *next;
+	LIST_HEAD(list_remove);
+
+	spin_lock(&priv->lock);
+	list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)
+		if (ent->msg.id == msg->id) {
+			list_move(&ent->list, &list_remove);
+			break;
+		}
+	wake_up(&priv->sndbuf_waitq);
+	spin_unlock(&priv->lock);
+	destroy_tty_buffer_list(&list_remove);
+}
+
+static ssize_t hvc_iucv_dev_termid_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+	size_t len;
+
+	len = sizeof(priv->srv_name);
+	memcpy(buf, priv->srv_name, len);
+	EBCASC(buf, len);
+	buf[len++] = '\n';
+	return len;
+}
+
+static ssize_t hvc_iucv_dev_state_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+	return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state);
+}
+
+static ssize_t hvc_iucv_dev_peer_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+	char vmid[9], ipuser[9];
+
+	memset(vmid, 0, sizeof(vmid));
+	memset(ipuser, 0, sizeof(ipuser));
+
+	spin_lock_bh(&priv->lock);
+	if (priv->iucv_state == IUCV_CONNECTED) {
+		memcpy(vmid, priv->info_path, 8);
+		memcpy(ipuser, priv->info_path + 8, 8);
+	}
+	spin_unlock_bh(&priv->lock);
+	EBCASC(ipuser, 8);
+
+	return sprintf(buf, "%s:%s\n", vmid, ipuser);
+}
+
+
+/* HVC operations */
+static const struct hv_ops hvc_iucv_ops = {
+	.get_chars = hvc_iucv_get_chars,
+	.put_chars = hvc_iucv_put_chars,
+	.notifier_add = hvc_iucv_notifier_add,
+	.notifier_del = hvc_iucv_notifier_del,
+	.notifier_hangup = hvc_iucv_notifier_hangup,
+	.dtr_rts = hvc_iucv_dtr_rts,
+};
+
+/* IUCV HVC device attributes */
+static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL);
+static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL);
+static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL);
+static struct attribute *hvc_iucv_dev_attrs[] = {
+	&dev_attr_termid.attr,
+	&dev_attr_state.attr,
+	&dev_attr_peer.attr,
+	NULL,
+};
+static struct attribute_group hvc_iucv_dev_attr_group = {
+	.attrs = hvc_iucv_dev_attrs,
+};
+static const struct attribute_group *hvc_iucv_dev_attr_groups[] = {
+	&hvc_iucv_dev_attr_group,
+	NULL,
+};
+
+
+/**
+ * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
+ * @id:			hvc_iucv_table index
+ * @is_console:		Flag if the instance is used as Linux console
+ *
+ * This function allocates a new hvc_iucv_private structure and stores
+ * the instance in hvc_iucv_table at index @id.
+ * Returns 0 on success; otherwise non-zero.
+ */
+static int __init hvc_iucv_alloc(int id, unsigned int is_console)
+{
+	struct hvc_iucv_private *priv;
+	char name[9];
+	int rc;
+
+	priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->lock);
+	INIT_LIST_HEAD(&priv->tty_outqueue);
+	INIT_LIST_HEAD(&priv->tty_inqueue);
+	INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);
+	init_waitqueue_head(&priv->sndbuf_waitq);
+
+	priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);
+	if (!priv->sndbuf) {
+		kfree(priv);
+		return -ENOMEM;
+	}
+
+	/* set console flag */
+	priv->is_console = is_console;
+
+	/* allocate hvc device */
+	priv->hvc = hvc_alloc(id, /*		 PAGE_SIZE */
+			      id, &hvc_iucv_ops, 256);
+	if (IS_ERR(priv->hvc)) {
+		rc = PTR_ERR(priv->hvc);
+		goto out_error_hvc;
+	}
+
+	/* notify HVC thread instead of using polling */
+	priv->hvc->irq_requested = 1;
+
+	/* setup iucv related information */
+	snprintf(name, 9, "lnxhvc%-2d", id);
+	memcpy(priv->srv_name, name, 8);
+	ASCEBC(priv->srv_name, 8);
+
+	/* create and setup device */
+	priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
+	if (!priv->dev) {
+		rc = -ENOMEM;
+		goto out_error_dev;
+	}
+	dev_set_name(priv->dev, "hvc_iucv%d", id);
+	dev_set_drvdata(priv->dev, priv);
+	priv->dev->bus = &iucv_bus;
+	priv->dev->parent = iucv_root;
+	priv->dev->groups = hvc_iucv_dev_attr_groups;
+	priv->dev->release = (void (*)(struct device *)) kfree;
+	rc = device_register(priv->dev);
+	if (rc) {
+		put_device(priv->dev);
+		goto out_error_dev;
+	}
+
+	hvc_iucv_table[id] = priv;
+	return 0;
+
+out_error_dev:
+	hvc_remove(priv->hvc);
+out_error_hvc:
+	free_page((unsigned long) priv->sndbuf);
+	kfree(priv);
+
+	return rc;
+}
+
+/**
+ * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
+ */
+static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
+{
+	hvc_remove(priv->hvc);
+	device_unregister(priv->dev);
+	free_page((unsigned long) priv->sndbuf);
+	kfree(priv);
+}
+
+/**
+ * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
+ * @filter:	String containing a comma-separated list of z/VM user IDs
+ * @dest:	Location where to store the parsed z/VM user ID
+ */
+static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
+{
+	const char *nextdelim, *residual;
+	size_t len;
+
+	nextdelim = strchr(filter, ',');
+	if (nextdelim) {
+		len = nextdelim - filter;
+		residual = nextdelim + 1;
+	} else {
+		len = strlen(filter);
+		residual = filter + len;
+	}
+
+	if (len == 0)
+		return ERR_PTR(-EINVAL);
+
+	/* check for '\n' (if called from sysfs) */
+	if (filter[len - 1] == '\n')
+		len--;
+
+	/* prohibit filter entries containing the wildcard character only */
+	if (len == 1 && *filter == FILTER_WILDCARD_CHAR)
+		return ERR_PTR(-EINVAL);
+
+	if (len > 8)
+		return ERR_PTR(-EINVAL);
+
+	/* pad with blanks and save upper case version of user ID */
+	memset(dest, ' ', 8);
+	while (len--)
+		dest[len] = toupper(filter[len]);
+	return residual;
+}
+
+/**
+ * hvc_iucv_setup_filter() - Set up z/VM user ID filter
+ * @filter:	String consisting of a comma-separated list of z/VM user IDs
+ *
+ * The function parses the @filter string and creates an array containing
+ * the list of z/VM user ID filter entries.
+ * Return code 0 means success, -EINVAL if the filter is syntactically
+ * incorrect, -ENOMEM if there was not enough memory to allocate the
+ * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.
+ */
+static int hvc_iucv_setup_filter(const char *val)
+{
+	const char *residual;
+	int err;
+	size_t size, count;
+	void *array, *old_filter;
+
+	count = strlen(val);
+	if (count == 0 || (count == 1 && val[0] == '\n')) {
+		size  = 0;
+		array = NULL;
+		goto out_replace_filter;	/* clear filter */
+	}
+
+	/* count user IDs in order to allocate sufficient memory */
+	size = 1;
+	residual = val;
+	while ((residual = strchr(residual, ',')) != NULL) {
+		residual++;
+		size++;
+	}
+
+	/* check if the specified list exceeds the filter limit */
+	if (size > MAX_VMID_FILTER)
+		return -ENOSPC;
+
+	array = kcalloc(size, 8, GFP_KERNEL);
+	if (!array)
+		return -ENOMEM;
+
+	count = size;
+	residual = val;
+	while (*residual && count) {
+		residual = hvc_iucv_parse_filter(residual,
+						 array + ((size - count) * 8));
+		if (IS_ERR(residual)) {
+			err = PTR_ERR(residual);
+			kfree(array);
+			goto out_err;
+		}
+		count--;
+	}
+
+out_replace_filter:
+	write_lock_bh(&hvc_iucv_filter_lock);
+	old_filter = hvc_iucv_filter;
+	hvc_iucv_filter_size = size;
+	hvc_iucv_filter = array;
+	write_unlock_bh(&hvc_iucv_filter_lock);
+	kfree(old_filter);
+
+	err = 0;
+out_err:
+	return err;
+}
+
+/**
+ * param_set_vmidfilter() - Set z/VM user ID filter parameter
+ * @val:	String consisting of a comma-separated list of z/VM user IDs
+ * @kp:		Kernel parameter pointing to hvc_iucv_filter array
+ *
+ * The function sets up the z/VM user ID filter specified as comma-separated
+ * list of user IDs in @val.
+ * Note: If it is called early in the boot process, @val is stored and
+ *	 parsed later in hvc_iucv_init().
+ */
+static int param_set_vmidfilter(const char *val, const struct kernel_param *kp)
+{
+	int rc;
+
+	if (!MACHINE_IS_VM || !hvc_iucv_devices)
+		return -ENODEV;
+
+	if (!val)
+		return -EINVAL;
+
+	rc = 0;
+	if (slab_is_available())
+		rc = hvc_iucv_setup_filter(val);
+	else
+		hvc_iucv_filter_string = val;	/* defer... */
+	return rc;
+}
+
+/**
+ * param_get_vmidfilter() - Get z/VM user ID filter
+ * @buffer:	Buffer to store z/VM user ID filter,
+ *		(buffer size assumption PAGE_SIZE)
+ * @kp:		Kernel parameter pointing to the hvc_iucv_filter array
+ *
+ * The function stores the filter as a comma-separated list of z/VM user IDs
+ * in @buffer. Typically, sysfs routines call this function for attr show.
+ */
+static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp)
+{
+	int rc;
+	size_t index, len;
+	void *start, *end;
+
+	if (!MACHINE_IS_VM || !hvc_iucv_devices)
+		return -ENODEV;
+
+	rc = 0;
+	read_lock_bh(&hvc_iucv_filter_lock);
+	for (index = 0; index < hvc_iucv_filter_size; index++) {
+		start = hvc_iucv_filter + (8 * index);
+		end   = memchr(start, ' ', 8);
+		len   = (end) ? end - start : 8;
+		memcpy(buffer + rc, start, len);
+		rc += len;
+		buffer[rc++] = ',';
+	}
+	read_unlock_bh(&hvc_iucv_filter_lock);
+	if (rc)
+		buffer[--rc] = '\0';	/* replace last comma and update rc */
+	return rc;
+}
+
+#define param_check_vmidfilter(name, p) __param_check(name, p, void)
+
+static const struct kernel_param_ops param_ops_vmidfilter = {
+	.set = param_set_vmidfilter,
+	.get = param_get_vmidfilter,
+};
+
+/**
+ * hvc_iucv_init() - z/VM IUCV HVC device driver initialization
+ */
+static int __init hvc_iucv_init(void)
+{
+	int rc;
+	unsigned int i;
+
+	if (!hvc_iucv_devices)
+		return -ENODEV;
+
+	if (!MACHINE_IS_VM) {
+		pr_notice("The z/VM IUCV HVC device driver cannot "
+			   "be used without z/VM\n");
+		rc = -ENODEV;
+		goto out_error;
+	}
+
+	if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {
+		pr_err("%lu is not a valid value for the hvc_iucv= "
+			"kernel parameter\n", hvc_iucv_devices);
+		rc = -EINVAL;
+		goto out_error;
+	}
+
+	/* parse hvc_iucv_allow string and create z/VM user ID filter list */
+	if (hvc_iucv_filter_string) {
+		rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
+		switch (rc) {
+		case 0:
+			break;
+		case -ENOMEM:
+			pr_err("Allocating memory failed with "
+				"reason code=%d\n", 3);
+			goto out_error;
+		case -EINVAL:
+			pr_err("hvc_iucv_allow= does not specify a valid "
+				"z/VM user ID list\n");
+			goto out_error;
+		case -ENOSPC:
+			pr_err("hvc_iucv_allow= specifies too many "
+				"z/VM user IDs\n");
+			goto out_error;
+		default:
+			goto out_error;
+		}
+	}
+
+	hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
+					   sizeof(struct iucv_tty_buffer),
+					   0, 0, NULL);
+	if (!hvc_iucv_buffer_cache) {
+		pr_err("Allocating memory failed with reason code=%d\n", 1);
+		rc = -ENOMEM;
+		goto out_error;
+	}
+
+	hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
+						    hvc_iucv_buffer_cache);
+	if (!hvc_iucv_mempool) {
+		pr_err("Allocating memory failed with reason code=%d\n", 2);
+		kmem_cache_destroy(hvc_iucv_buffer_cache);
+		rc = -ENOMEM;
+		goto out_error;
+	}
+
+	/* register the first terminal device as console
+	 * (must be done before allocating hvc terminal devices) */
+	rc = hvc_instantiate(0, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
+	if (rc) {
+		pr_err("Registering HVC terminal device as "
+		       "Linux console failed\n");
+		goto out_error_memory;
+	}
+
+	/* allocate hvc_iucv_private structs */
+	for (i = 0; i < hvc_iucv_devices; i++) {
+		rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);
+		if (rc) {
+			pr_err("Creating a new HVC terminal device "
+				"failed with error code=%d\n", rc);
+			goto out_error_hvc;
+		}
+	}
+
+	/* register IUCV callback handler */
+	rc = iucv_register(&hvc_iucv_handler, 0);
+	if (rc) {
+		pr_err("Registering IUCV handlers failed with error code=%d\n",
+			rc);
+		goto out_error_hvc;
+	}
+
+	return 0;
+
+out_error_hvc:
+	for (i = 0; i < hvc_iucv_devices; i++)
+		if (hvc_iucv_table[i])
+			hvc_iucv_destroy(hvc_iucv_table[i]);
+out_error_memory:
+	mempool_destroy(hvc_iucv_mempool);
+	kmem_cache_destroy(hvc_iucv_buffer_cache);
+out_error:
+	kfree(hvc_iucv_filter);
+	hvc_iucv_devices = 0; /* ensure that we do not provide any device */
+	return rc;
+}
+
+/**
+ * hvc_iucv_config() - Parsing of hvc_iucv=  kernel command line parameter
+ * @val:	Parameter value (numeric)
+ */
+static	int __init hvc_iucv_config(char *val)
+{
+	if (kstrtoul(val, 10, &hvc_iucv_devices))
+		pr_warn("hvc_iucv= invalid parameter value '%s'\n", val);
+	return 1;
+}
+
+
+device_initcall(hvc_iucv_init);
+__setup("hvc_iucv=", hvc_iucv_config);
+core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);
diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
new file mode 100644
index 000000000..992e199e0
--- /dev/null
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * opal driver interface to hvc_console.c
+ *
+ * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+
+#include <asm/hvconsole.h>
+#include <asm/firmware.h>
+#include <asm/hvsi.h>
+#include <asm/udbg.h>
+#include <asm/opal.h>
+
+#include "hvc_console.h"
+
+static const char hvc_opal_name[] = "hvc_opal";
+
+static const struct of_device_id hvc_opal_match[] = {
+	{ .name = "serial", .compatible = "ibm,opal-console-raw" },
+	{ .name = "serial", .compatible = "ibm,opal-console-hvsi" },
+	{ },
+};
+
+typedef enum hv_protocol {
+	HV_PROTOCOL_RAW,
+	HV_PROTOCOL_HVSI
+} hv_protocol_t;
+
+struct hvc_opal_priv {
+	hv_protocol_t		proto;	/* Raw data or HVSI packets */
+	struct hvsi_priv	hvsi;	/* HVSI specific data */
+};
+static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
+
+/* For early boot console */
+static struct hvc_opal_priv hvc_opal_boot_priv;
+static u32 hvc_opal_boot_termno;
+
+static const struct hv_ops hvc_opal_raw_ops = {
+	.get_chars = opal_get_chars,
+	.put_chars = opal_put_chars,
+	.flush = opal_flush_chars,
+	.notifier_add = notifier_add_irq,
+	.notifier_del = notifier_del_irq,
+	.notifier_hangup = notifier_hangup_irq,
+};
+
+static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return -ENODEV;
+
+	return hvsilib_get_chars(&pv->hvsi, buf, count);
+}
+
+static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return -ENODEV;
+
+	return hvsilib_put_chars(&pv->hvsi, buf, count);
+}
+
+static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+	int rc;
+
+	pr_devel("HVSI@%x: do open !\n", hp->vtermno);
+
+	rc = notifier_add_irq(hp, data);
+	if (rc)
+		return rc;
+
+	return hvsilib_open(&pv->hvsi, hp);
+}
+
+static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: do close !\n", hp->vtermno);
+
+	hvsilib_close(&pv->hvsi, hp);
+
+	notifier_del_irq(hp, data);
+}
+
+static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
+
+	hvsilib_close(&pv->hvsi, hp);
+
+	notifier_hangup_irq(hp, data);
+}
+
+static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+	if (!pv)
+		return -EINVAL;
+	return pv->hvsi.mctrl;
+}
+
+static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
+				unsigned int clear)
+{
+	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
+		 hp->vtermno, set, clear);
+
+	if (set & TIOCM_DTR)
+		hvsilib_write_mctrl(&pv->hvsi, 1);
+	else if (clear & TIOCM_DTR)
+		hvsilib_write_mctrl(&pv->hvsi, 0);
+
+	return 0;
+}
+
+static const struct hv_ops hvc_opal_hvsi_ops = {
+	.get_chars = hvc_opal_hvsi_get_chars,
+	.put_chars = hvc_opal_hvsi_put_chars,
+	.flush = opal_flush_chars,
+	.notifier_add = hvc_opal_hvsi_open,
+	.notifier_del = hvc_opal_hvsi_close,
+	.notifier_hangup = hvc_opal_hvsi_hangup,
+	.tiocmget = hvc_opal_hvsi_tiocmget,
+	.tiocmset = hvc_opal_hvsi_tiocmset,
+};
+
+static int hvc_opal_probe(struct platform_device *dev)
+{
+	const struct hv_ops *ops;
+	struct hvc_struct *hp;
+	struct hvc_opal_priv *pv;
+	hv_protocol_t proto;
+	unsigned int termno, irq, boot = 0;
+	const __be32 *reg;
+
+	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
+		proto = HV_PROTOCOL_RAW;
+		ops = &hvc_opal_raw_ops;
+	} else if (of_device_is_compatible(dev->dev.of_node,
+					   "ibm,opal-console-hvsi")) {
+		proto = HV_PROTOCOL_HVSI;
+		ops = &hvc_opal_hvsi_ops;
+	} else {
+		pr_err("hvc_opal: Unknown protocol for %pOF\n",
+		       dev->dev.of_node);
+		return -ENXIO;
+	}
+
+	reg = of_get_property(dev->dev.of_node, "reg", NULL);
+	termno = reg ? be32_to_cpup(reg) : 0;
+
+	/* Is it our boot one ? */
+	if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
+		pv = hvc_opal_privs[termno];
+		boot = 1;
+	} else if (hvc_opal_privs[termno] == NULL) {
+		pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
+		if (!pv)
+			return -ENOMEM;
+		pv->proto = proto;
+		hvc_opal_privs[termno] = pv;
+		if (proto == HV_PROTOCOL_HVSI) {
+			/*
+			 * We want put_chars to be atomic to avoid mangling of
+			 * hvsi packets.
+			 */
+			hvsilib_init(&pv->hvsi,
+				     opal_get_chars, opal_put_chars_atomic,
+				     termno, 0);
+		}
+
+		/* Instanciate now to establish a mapping index==vtermno */
+		hvc_instantiate(termno, termno, ops);
+	} else {
+		pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
+		       dev->dev.of_node, termno);
+		return -ENXIO;
+	}
+
+	pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
+		proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
+		dev->dev.of_node,
+		boot ? " (boot console)" : "");
+
+	irq = irq_of_parse_and_map(dev->dev.of_node, 0);
+	if (!irq) {
+		pr_info("hvc%d: No interrupts property, using OPAL event\n",
+				termno);
+		irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
+	}
+
+	if (!irq) {
+		pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
+			dev->dev.of_node);
+		return irq;
+	}
+
+	hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
+	if (IS_ERR(hp))
+		return PTR_ERR(hp);
+
+	/* hvc consoles on powernv may need to share a single irq */
+	hp->flags = IRQF_SHARED;
+	dev_set_drvdata(&dev->dev, hp);
+
+	return 0;
+}
+
+static int hvc_opal_remove(struct platform_device *dev)
+{
+	struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
+	int rc, termno;
+
+	termno = hp->vtermno;
+	rc = hvc_remove(hp);
+	if (rc == 0) {
+		if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
+			kfree(hvc_opal_privs[termno]);
+		hvc_opal_privs[termno] = NULL;
+	}
+	return rc;
+}
+
+static struct platform_driver hvc_opal_driver = {
+	.probe		= hvc_opal_probe,
+	.remove		= hvc_opal_remove,
+	.driver		= {
+		.name	= hvc_opal_name,
+		.of_match_table	= hvc_opal_match,
+	}
+};
+
+static int __init hvc_opal_init(void)
+{
+	if (!firmware_has_feature(FW_FEATURE_OPAL))
+		return -ENODEV;
+
+	/* Register as a vio device to receive callbacks */
+	return platform_driver_register(&hvc_opal_driver);
+}
+device_initcall(hvc_opal_init);
+
+static void udbg_opal_putc(char c)
+{
+	unsigned int termno = hvc_opal_boot_termno;
+	int count = -1;
+
+	if (c == '\n')
+		udbg_opal_putc('\r');
+
+	do {
+		switch(hvc_opal_boot_priv.proto) {
+		case HV_PROTOCOL_RAW:
+			count = opal_put_chars(termno, &c, 1);
+			break;
+		case HV_PROTOCOL_HVSI:
+			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
+			break;
+		}
+
+		/* This is needed for the cosole to flush
+		 * when there aren't any interrupts.
+		 */
+		opal_flush_console(termno);
+	} while(count == 0 || count == -EAGAIN);
+}
+
+static int udbg_opal_getc_poll(void)
+{
+	unsigned int termno = hvc_opal_boot_termno;
+	int rc = 0;
+	char c;
+
+	switch(hvc_opal_boot_priv.proto) {
+	case HV_PROTOCOL_RAW:
+		rc = opal_get_chars(termno, &c, 1);
+		break;
+	case HV_PROTOCOL_HVSI:
+		rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
+		break;
+	}
+	if (!rc)
+		return -1;
+	return c;
+}
+
+static int udbg_opal_getc(void)
+{
+	int ch;
+	for (;;) {
+		ch = udbg_opal_getc_poll();
+		if (ch != -1)
+			return ch;
+	}
+}
+
+static void udbg_init_opal_common(void)
+{
+	udbg_putc = udbg_opal_putc;
+	udbg_getc = udbg_opal_getc;
+	udbg_getc_poll = udbg_opal_getc_poll;
+}
+
+void __init hvc_opal_init_early(void)
+{
+	struct device_node *stdout_node = of_node_get(of_stdout);
+	const __be32 *termno;
+	const struct hv_ops *ops;
+	u32 index;
+
+	/* If the console wasn't in /chosen, try /ibm,opal */
+	if (!stdout_node) {
+		struct device_node *opal, *np;
+
+		/* Current OPAL takeover doesn't provide the stdout
+		 * path, so we hard wire it
+		 */
+		opal = of_find_node_by_path("/ibm,opal/consoles");
+		if (opal) {
+			pr_devel("hvc_opal: Found consoles in new location\n");
+		} else {
+			opal = of_find_node_by_path("/ibm,opal");
+			if (opal)
+				pr_devel("hvc_opal: "
+					 "Found consoles in old location\n");
+		}
+		if (!opal)
+			return;
+		for_each_child_of_node(opal, np) {
+			if (of_node_name_eq(np, "serial")) {
+				stdout_node = np;
+				break;
+			}
+		}
+		of_node_put(opal);
+	}
+	if (!stdout_node)
+		return;
+	termno = of_get_property(stdout_node, "reg", NULL);
+	index = termno ? be32_to_cpup(termno) : 0;
+	if (index >= MAX_NR_HVC_CONSOLES)
+		return;
+	hvc_opal_privs[index] = &hvc_opal_boot_priv;
+
+	/* Check the protocol */
+	if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
+		hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
+		ops = &hvc_opal_raw_ops;
+		pr_devel("hvc_opal: Found RAW console\n");
+	}
+	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
+		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
+		ops = &hvc_opal_hvsi_ops;
+		hvsilib_init(&hvc_opal_boot_priv.hvsi,
+			     opal_get_chars, opal_put_chars_atomic,
+			     index, 1);
+		/* HVSI, perform the handshake now */
+		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
+		pr_devel("hvc_opal: Found HVSI console\n");
+	} else
+		goto out;
+	hvc_opal_boot_termno = index;
+	udbg_init_opal_common();
+	add_preferred_console("hvc", index, NULL);
+	hvc_instantiate(index, index, ops);
+out:
+	of_node_put(stdout_node);
+}
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
+void __init udbg_init_debug_opal_raw(void)
+{
+	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
+	hvc_opal_privs[index] = &hvc_opal_boot_priv;
+	hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
+	hvc_opal_boot_termno = index;
+	udbg_init_opal_common();
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
+void __init udbg_init_debug_opal_hvsi(void)
+{
+	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
+	hvc_opal_privs[index] = &hvc_opal_boot_priv;
+	hvc_opal_boot_termno = index;
+	udbg_init_opal_common();
+	hvsilib_init(&hvc_opal_boot_priv.hvsi,
+		     opal_get_chars, opal_put_chars_atomic,
+		     index, 1);
+	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
new file mode 100644
index 000000000..31f53fa77
--- /dev/null
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2008 David Gibson, IBM Corporation
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ */
+
+#include <linux/console.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+
+#include <asm/sbi.h>
+
+#include "hvc_console.h"
+
+static int hvc_sbi_tty_put(uint32_t vtermno, const char *buf, int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++)
+		sbi_console_putchar(buf[i]);
+
+	return i;
+}
+
+static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count)
+{
+	int i, c;
+
+	for (i = 0; i < count; i++) {
+		c = sbi_console_getchar();
+		if (c < 0)
+			break;
+		buf[i] = c;
+	}
+
+	return i;
+}
+
+static const struct hv_ops hvc_sbi_ops = {
+	.get_chars = hvc_sbi_tty_get,
+	.put_chars = hvc_sbi_tty_put,
+};
+
+static int __init hvc_sbi_init(void)
+{
+	return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16));
+}
+device_initcall(hvc_sbi_init);
+
+static int __init hvc_sbi_console_init(void)
+{
+	hvc_instantiate(0, 0, &hvc_sbi_ops);
+
+	return 0;
+}
+console_initcall(hvc_sbi_console_init);
diff --git a/drivers/tty/hvc/hvc_rtas.c b/drivers/tty/hvc/hvc_rtas.c
new file mode 100644
index 000000000..184d325ab
--- /dev/null
+++ b/drivers/tty/hvc/hvc_rtas.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IBM RTAS driver interface to hvc_console.c
+ *
+ * (C) Copyright IBM Corporation 2001-2005
+ * (C) Copyright Red Hat, Inc. 2005
+ *
+ * Author(s): Maximino Augilar <IBM STI Design Center>
+ *	    : Ryan S. Arnold <rsa@us.ibm.com>
+ *	    : Utz Bacher <utz.bacher@de.ibm.com>
+ *	    : David Woodhouse <dwmw2@infradead.org>
+ *
+ *    inspired by drivers/char/hvc_console.c
+ *    written by Anton Blanchard and Paul Mackerras
+ */
+
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+
+#include <asm/irq.h>
+#include <asm/rtas.h>
+#include "hvc_console.h"
+
+#define hvc_rtas_cookie 0x67781e15
+static struct hvc_struct *hvc_rtas_dev;
+
+static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
+static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
+
+static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf,
+		int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
+			break;
+	}
+
+	return i;
+}
+
+static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
+{
+	int i, c;
+
+	for (i = 0; i < count; i++) {
+		if (rtas_call(rtascons_get_char_token, 0, 2, &c))
+			break;
+
+		buf[i] = c;
+	}
+
+	return i;
+}
+
+static const struct hv_ops hvc_rtas_get_put_ops = {
+	.get_chars = hvc_rtas_read_console,
+	.put_chars = hvc_rtas_write_console,
+};
+
+static int __init hvc_rtas_init(void)
+{
+	struct hvc_struct *hp;
+
+	if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
+		rtascons_put_char_token = rtas_token("put-term-char");
+	if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
+		return -EIO;
+
+	if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
+		rtascons_get_char_token = rtas_token("get-term-char");
+	if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
+		return -EIO;
+
+	BUG_ON(hvc_rtas_dev);
+
+	/* Allocate an hvc_struct for the console device we instantiated
+	 * earlier.  Save off hp so that we can return it on exit */
+	hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16);
+	if (IS_ERR(hp))
+		return PTR_ERR(hp);
+
+	hvc_rtas_dev = hp;
+
+	return 0;
+}
+device_initcall(hvc_rtas_init);
+
+/* This will happen prior to module init.  There is no tty at this time? */
+static int __init hvc_rtas_console_init(void)
+{
+	rtascons_put_char_token = rtas_token("put-term-char");
+	if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
+		return -EIO;
+
+	rtascons_get_char_token = rtas_token("get-term-char");
+	if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
+		return -EIO;
+
+	hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
+	add_preferred_console("hvc", 0, NULL);
+
+	return 0;
+}
+console_initcall(hvc_rtas_console_init);
diff --git a/drivers/tty/hvc/hvc_udbg.c b/drivers/tty/hvc/hvc_udbg.c
new file mode 100644
index 000000000..ff0dcc564
--- /dev/null
+++ b/drivers/tty/hvc/hvc_udbg.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * udbg interface to hvc_console.c
+ *
+ * (C) Copyright David Gibson, IBM Corporation 2008.
+ */
+
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/irq.h>
+
+#include <asm/udbg.h>
+
+#include "hvc_console.h"
+
+static struct hvc_struct *hvc_udbg_dev;
+
+static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
+{
+	int i;
+
+	for (i = 0; i < count && udbg_putc; i++)
+		udbg_putc(buf[i]);
+
+	return i;
+}
+
+static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
+{
+	int i, c;
+
+	if (!udbg_getc_poll)
+		return 0;
+
+	for (i = 0; i < count; i++) {
+		if ((c = udbg_getc_poll()) == -1)
+			break;
+		buf[i] = c;
+	}
+
+	return i;
+}
+
+static const struct hv_ops hvc_udbg_ops = {
+	.get_chars = hvc_udbg_get,
+	.put_chars = hvc_udbg_put,
+};
+
+static int __init hvc_udbg_init(void)
+{
+	struct hvc_struct *hp;
+
+	if (!udbg_putc)
+		return -ENODEV;
+
+	BUG_ON(hvc_udbg_dev);
+
+	hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
+	if (IS_ERR(hp))
+		return PTR_ERR(hp);
+
+	hvc_udbg_dev = hp;
+
+	return 0;
+}
+device_initcall(hvc_udbg_init);
+
+static int __init hvc_udbg_console_init(void)
+{
+	if (!udbg_putc)
+		return -ENODEV;
+
+	hvc_instantiate(0, 0, &hvc_udbg_ops);
+	add_preferred_console("hvc", 0, NULL);
+
+	return 0;
+}
+console_initcall(hvc_udbg_console_init);
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
new file mode 100644
index 000000000..736b230f5
--- /dev/null
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vio driver interface to hvc_console.c
+ *
+ * This code was moved here to allow the remaining code to be reused as a
+ * generic polling mode with semi-reliable transport driver core to the
+ * console and tty subsystems.
+ *
+ *
+ * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ *  Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * TODO:
+ *
+ *   - handle error in sending hvsi protocol packets
+ *   - retry nego on subsequent sends ?
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+#include <linux/of.h>
+
+#include <asm/hvconsole.h>
+#include <asm/vio.h>
+#include <asm/hvsi.h>
+#include <asm/udbg.h>
+#include <asm/machdep.h>
+
+#include "hvc_console.h"
+
+static const char hvc_driver_name[] = "hvc_console";
+
+static const struct vio_device_id hvc_driver_table[] = {
+	{"serial", "hvterm1"},
+#ifndef HVC_OLD_HVSI
+	{"serial", "hvterm-protocol"},
+#endif
+	{ "", "" }
+};
+
+typedef enum hv_protocol {
+	HV_PROTOCOL_RAW,
+	HV_PROTOCOL_HVSI
+} hv_protocol_t;
+
+struct hvterm_priv {
+	u32			termno;	/* HV term number */
+	hv_protocol_t		proto;	/* Raw data or HVSI packets */
+	struct hvsi_priv	hvsi;	/* HVSI specific data */
+	spinlock_t		buf_lock;
+	char			buf[SIZE_VIO_GET_CHARS];
+	int			left;
+	int			offset;
+};
+static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
+/* For early boot console */
+static struct hvterm_priv hvterm_priv0;
+
+static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+	unsigned long i;
+	unsigned long flags;
+	int got;
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	spin_lock_irqsave(&pv->buf_lock, flags);
+
+	if (pv->left == 0) {
+		pv->offset = 0;
+		pv->left = hvc_get_chars(pv->termno, pv->buf, count);
+
+		/*
+		 * Work around a HV bug where it gives us a null
+		 * after every \r.  -- paulus
+		 */
+		for (i = 1; i < pv->left; ++i) {
+			if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
+				--pv->left;
+				if (i < pv->left) {
+					memmove(&pv->buf[i], &pv->buf[i+1],
+						pv->left - i);
+				}
+			}
+		}
+	}
+
+	got = min(count, pv->left);
+	memcpy(buf, &pv->buf[pv->offset], got);
+	pv->offset += got;
+	pv->left -= got;
+
+	spin_unlock_irqrestore(&pv->buf_lock, flags);
+
+	return got;
+}
+
+/**
+ * hvterm_raw_put_chars: send characters to firmware for given vterm adapter
+ * @vtermno: The virtual terminal number.
+ * @buf: The characters to send. Because of the underlying hypercall in
+ *       hvc_put_chars(), this buffer must be at least 16 bytes long, even if
+ *       you are sending fewer chars.
+ * @count: number of chars to send.
+ */
+static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvc_put_chars(pv->termno, buf, count);
+}
+
+static const struct hv_ops hvterm_raw_ops = {
+	.get_chars = hvterm_raw_get_chars,
+	.put_chars = hvterm_raw_put_chars,
+	.notifier_add = notifier_add_irq,
+	.notifier_del = notifier_del_irq,
+	.notifier_hangup = notifier_hangup_irq,
+};
+
+static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvsilib_get_chars(&pv->hvsi, buf, count);
+}
+
+static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvsilib_put_chars(&pv->hvsi, buf, count);
+}
+
+static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+	int rc;
+
+	pr_devel("HVSI@%x: open !\n", pv->termno);
+
+	rc = notifier_add_irq(hp, data);
+	if (rc)
+		return rc;
+
+	return hvsilib_open(&pv->hvsi, hp);
+}
+
+static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: do close !\n", pv->termno);
+
+	hvsilib_close(&pv->hvsi, hp);
+
+	notifier_del_irq(hp, data);
+}
+
+static void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: do hangup !\n", pv->termno);
+
+	hvsilib_close(&pv->hvsi, hp);
+
+	notifier_hangup_irq(hp, data);
+}
+
+static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	if (!pv)
+		return -EINVAL;
+	return pv->hvsi.mctrl;
+}
+
+static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
+				unsigned int clear)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
+		 pv->termno, set, clear);
+
+	if (set & TIOCM_DTR)
+		hvsilib_write_mctrl(&pv->hvsi, 1);
+	else if (clear & TIOCM_DTR)
+		hvsilib_write_mctrl(&pv->hvsi, 0);
+
+	return 0;
+}
+
+static const struct hv_ops hvterm_hvsi_ops = {
+	.get_chars = hvterm_hvsi_get_chars,
+	.put_chars = hvterm_hvsi_put_chars,
+	.notifier_add = hvterm_hvsi_open,
+	.notifier_del = hvterm_hvsi_close,
+	.notifier_hangup = hvterm_hvsi_hangup,
+	.tiocmget = hvterm_hvsi_tiocmget,
+	.tiocmset = hvterm_hvsi_tiocmset,
+};
+
+static void udbg_hvc_putc(char c)
+{
+	int count = -1;
+	unsigned char bounce_buffer[16];
+
+	if (!hvterm_privs[0])
+		return;
+
+	if (c == '\n')
+		udbg_hvc_putc('\r');
+
+	do {
+		switch(hvterm_privs[0]->proto) {
+		case HV_PROTOCOL_RAW:
+			/*
+			 * hvterm_raw_put_chars requires at least a 16-byte
+			 * buffer, so go via the bounce buffer
+			 */
+			bounce_buffer[0] = c;
+			count = hvterm_raw_put_chars(0, bounce_buffer, 1);
+			break;
+		case HV_PROTOCOL_HVSI:
+			count = hvterm_hvsi_put_chars(0, &c, 1);
+			break;
+		}
+	} while (count == 0 || count == -EAGAIN);
+}
+
+static int udbg_hvc_getc_poll(void)
+{
+	int rc = 0;
+	char c;
+
+	if (!hvterm_privs[0])
+		return -1;
+
+	switch(hvterm_privs[0]->proto) {
+	case HV_PROTOCOL_RAW:
+		rc = hvterm_raw_get_chars(0, &c, 1);
+		break;
+	case HV_PROTOCOL_HVSI:
+		rc = hvterm_hvsi_get_chars(0, &c, 1);
+		break;
+	}
+	if (!rc)
+		return -1;
+	return c;
+}
+
+static int udbg_hvc_getc(void)
+{
+	int ch;
+
+	if (!hvterm_privs[0])
+		return -1;
+
+	for (;;) {
+		ch = udbg_hvc_getc_poll();
+		if (ch == -1) {
+			/* This shouldn't be needed...but... */
+			volatile unsigned long delay;
+			for (delay=0; delay < 2000000; delay++)
+				;
+		} else {
+			return ch;
+		}
+	}
+}
+
+static int hvc_vio_probe(struct vio_dev *vdev,
+				   const struct vio_device_id *id)
+{
+	const struct hv_ops *ops;
+	struct hvc_struct *hp;
+	struct hvterm_priv *pv;
+	hv_protocol_t proto;
+	int i, termno = -1;
+
+	/* probed with invalid parameters. */
+	if (!vdev || !id)
+		return -EPERM;
+
+	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
+		proto = HV_PROTOCOL_RAW;
+		ops = &hvterm_raw_ops;
+	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
+		proto = HV_PROTOCOL_HVSI;
+		ops = &hvterm_hvsi_ops;
+	} else {
+		pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node);
+		return -ENXIO;
+	}
+
+	pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n",
+		 vdev->dev.of_node,
+		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
+
+	/* Is it our boot one ? */
+	if (hvterm_privs[0] == &hvterm_priv0 &&
+	    vdev->unit_address == hvterm_priv0.termno) {
+		pv = hvterm_privs[0];
+		termno = 0;
+		pr_devel("->boot console, using termno 0\n");
+	}
+	/* nope, allocate a new one */
+	else {
+		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
+			if (!hvterm_privs[i])
+				termno = i;
+		pr_devel("->non-boot console, using termno %d\n", termno);
+		if (termno < 0)
+			return -ENODEV;
+		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
+		if (!pv)
+			return -ENOMEM;
+		pv->termno = vdev->unit_address;
+		pv->proto = proto;
+		spin_lock_init(&pv->buf_lock);
+		hvterm_privs[termno] = pv;
+		hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
+			     pv->termno, 0);
+	}
+
+	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
+	if (IS_ERR(hp))
+		return PTR_ERR(hp);
+	dev_set_drvdata(&vdev->dev, hp);
+
+	/* register udbg if it's not there already for console 0 */
+	if (hp->index == 0 && !udbg_putc) {
+		udbg_putc = udbg_hvc_putc;
+		udbg_getc = udbg_hvc_getc;
+		udbg_getc_poll = udbg_hvc_getc_poll;
+	}
+
+	return 0;
+}
+
+static struct vio_driver hvc_vio_driver = {
+	.id_table	= hvc_driver_table,
+	.probe		= hvc_vio_probe,
+	.name		= hvc_driver_name,
+	.driver = {
+		.suppress_bind_attrs	= true,
+	},
+};
+
+static int __init hvc_vio_init(void)
+{
+	int rc;
+
+	/* Register as a vio device to receive callbacks */
+	rc = vio_register_driver(&hvc_vio_driver);
+
+	return rc;
+}
+device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
+
+void __init hvc_vio_init_early(void)
+{
+	const __be32 *termno;
+	const struct hv_ops *ops;
+
+	/* find the boot console from /chosen/stdout */
+	/* Check if it's a virtual terminal */
+	if (!of_node_name_prefix(of_stdout, "vty"))
+		return;
+	termno = of_get_property(of_stdout, "reg", NULL);
+	if (termno == NULL)
+		return;
+	hvterm_priv0.termno = of_read_number(termno, 1);
+	spin_lock_init(&hvterm_priv0.buf_lock);
+	hvterm_privs[0] = &hvterm_priv0;
+
+	/* Check the protocol */
+	if (of_device_is_compatible(of_stdout, "hvterm1")) {
+		hvterm_priv0.proto = HV_PROTOCOL_RAW;
+		ops = &hvterm_raw_ops;
+	}
+	else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
+		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+		ops = &hvterm_hvsi_ops;
+		hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
+			     hvterm_priv0.termno, 1);
+		/* HVSI, perform the handshake now */
+		hvsilib_establish(&hvterm_priv0.hvsi);
+	} else
+		return;
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+#ifdef HVC_OLD_HVSI
+	/* When using the old HVSI driver don't register the HVC
+	 * backend for HVSI, only do udbg
+	 */
+	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
+		return;
+#endif
+	/* Check whether the user has requested a different console. */
+	if (!strstr(boot_command_line, "console="))
+		add_preferred_console("hvc", 0, NULL);
+	hvc_instantiate(0, 0, ops);
+}
+
+/* call this from early_init() for a working debug console on
+ * vterm capable LPAR machines
+ */
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
+void __init udbg_init_debug_lpar(void)
+{
+	/*
+	 * If we're running as a hypervisor then we definitely can't call the
+	 * hypervisor to print debug output (we *are* the hypervisor), so don't
+	 * register if we detect that MSR_HV=1.
+	 */
+	if (mfmsr() & MSR_HV)
+		return;
+
+	hvterm_privs[0] = &hvterm_priv0;
+	hvterm_priv0.termno = 0;
+	hvterm_priv0.proto = HV_PROTOCOL_RAW;
+	spin_lock_init(&hvterm_priv0.buf_lock);
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
+void __init udbg_init_debug_lpar_hvsi(void)
+{
+	/* See comment above in udbg_init_debug_lpar() */
+	if (mfmsr() & MSR_HV)
+		return;
+
+	hvterm_privs[0] = &hvterm_priv0;
+	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
+	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+	spin_lock_init(&hvterm_priv0.buf_lock);
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+	hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
+		     hvterm_priv0.termno, 1);
+	hvsilib_establish(&hvterm_priv0.hvsi);
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
new file mode 100644
index 000000000..34c01874f
--- /dev/null
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -0,0 +1,771 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * xen console driver interface to hvc_console.c
+ *
+ * (c) 2007 Gerd Hoffmann <kraxel@suse.de>
+ */
+
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/serial_core.h>
+
+#include <asm/io.h>
+#include <asm/xen/hypervisor.h>
+
+#include <xen/xen.h>
+#include <xen/interface/xen.h>
+#include <xen/hvm.h>
+#include <xen/grant_table.h>
+#include <xen/page.h>
+#include <xen/events.h>
+#include <xen/interface/io/console.h>
+#include <xen/interface/sched.h>
+#include <xen/hvc-console.h>
+#include <xen/xenbus.h>
+
+#include "hvc_console.h"
+
+#define HVC_COOKIE   0x58656e /* "Xen" in hex */
+
+struct xencons_info {
+	struct list_head list;
+	struct xenbus_device *xbdev;
+	struct xencons_interface *intf;
+	unsigned int evtchn;
+	XENCONS_RING_IDX out_cons;
+	unsigned int out_cons_same;
+	struct hvc_struct *hvc;
+	int irq;
+	int vtermno;
+	grant_ref_t gntref;
+	spinlock_t ring_lock;
+};
+
+static LIST_HEAD(xenconsoles);
+static DEFINE_SPINLOCK(xencons_lock);
+
+/* ------------------------------------------------------------------ */
+
+static struct xencons_info *vtermno_to_xencons(int vtermno)
+{
+	struct xencons_info *entry, *ret = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&xencons_lock, flags);
+	if (list_empty(&xenconsoles)) {
+		spin_unlock_irqrestore(&xencons_lock, flags);
+		return NULL;
+	}
+
+	list_for_each_entry(entry, &xenconsoles, list) {
+		if (entry->vtermno == vtermno) {
+			ret  = entry;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&xencons_lock, flags);
+
+	return ret;
+}
+
+static inline int xenbus_devid_to_vtermno(int devid)
+{
+	return devid + HVC_COOKIE;
+}
+
+static inline void notify_daemon(struct xencons_info *cons)
+{
+	/* Use evtchn: this is called early, before irq is set up. */
+	notify_remote_via_evtchn(cons->evtchn);
+}
+
+static int __write_console(struct xencons_info *xencons,
+		const char *data, int len)
+{
+	XENCONS_RING_IDX cons, prod;
+	struct xencons_interface *intf = xencons->intf;
+	int sent = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&xencons->ring_lock, flags);
+	cons = intf->out_cons;
+	prod = intf->out_prod;
+	mb();			/* update queue values before going on */
+
+	if ((prod - cons) > sizeof(intf->out)) {
+		spin_unlock_irqrestore(&xencons->ring_lock, flags);
+		pr_err_once("xencons: Illegal ring page indices");
+		return -EINVAL;
+	}
+
+	while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
+		intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
+
+	wmb();			/* write ring before updating pointer */
+	intf->out_prod = prod;
+	spin_unlock_irqrestore(&xencons->ring_lock, flags);
+
+	if (sent)
+		notify_daemon(xencons);
+	return sent;
+}
+
+static int domU_write_console(uint32_t vtermno, const char *data, int len)
+{
+	int ret = len;
+	struct xencons_info *cons = vtermno_to_xencons(vtermno);
+	if (cons == NULL)
+		return -EINVAL;
+
+	/*
+	 * Make sure the whole buffer is emitted, polling if
+	 * necessary.  We don't ever want to rely on the hvc daemon
+	 * because the most interesting console output is when the
+	 * kernel is crippled.
+	 */
+	while (len) {
+		int sent = __write_console(cons, data, len);
+
+		if (sent < 0)
+			return sent;
+
+		data += sent;
+		len -= sent;
+
+		if (unlikely(len))
+			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
+	}
+
+	return ret;
+}
+
+static int domU_read_console(uint32_t vtermno, char *buf, int len)
+{
+	struct xencons_interface *intf;
+	XENCONS_RING_IDX cons, prod;
+	int recv = 0;
+	struct xencons_info *xencons = vtermno_to_xencons(vtermno);
+	unsigned int eoiflag = 0;
+	unsigned long flags;
+
+	if (xencons == NULL)
+		return -EINVAL;
+	intf = xencons->intf;
+
+	spin_lock_irqsave(&xencons->ring_lock, flags);
+	cons = intf->in_cons;
+	prod = intf->in_prod;
+	mb();			/* get pointers before reading ring */
+
+	if ((prod - cons) > sizeof(intf->in)) {
+		spin_unlock_irqrestore(&xencons->ring_lock, flags);
+		pr_err_once("xencons: Illegal ring page indices");
+		return -EINVAL;
+	}
+
+	while (cons != prod && recv < len)
+		buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
+
+	mb();			/* read ring before consuming */
+	intf->in_cons = cons;
+
+	/*
+	 * When to mark interrupt having been spurious:
+	 * - there was no new data to be read, and
+	 * - the backend did not consume some output bytes, and
+	 * - the previous round with no read data didn't see consumed bytes
+	 *   (we might have a race with an interrupt being in flight while
+	 *   updating xencons->out_cons, so account for that by allowing one
+	 *   round without any visible reason)
+	 */
+	if (intf->out_cons != xencons->out_cons) {
+		xencons->out_cons = intf->out_cons;
+		xencons->out_cons_same = 0;
+	}
+	if (!recv && xencons->out_cons_same++ > 1) {
+		eoiflag = XEN_EOI_FLAG_SPURIOUS;
+	}
+	spin_unlock_irqrestore(&xencons->ring_lock, flags);
+
+	if (recv) {
+		notify_daemon(xencons);
+	}
+
+	xen_irq_lateeoi(xencons->irq, eoiflag);
+
+	return recv;
+}
+
+static const struct hv_ops domU_hvc_ops = {
+	.get_chars = domU_read_console,
+	.put_chars = domU_write_console,
+	.notifier_add = notifier_add_irq,
+	.notifier_del = notifier_del_irq,
+	.notifier_hangup = notifier_hangup_irq,
+};
+
+static int dom0_read_console(uint32_t vtermno, char *buf, int len)
+{
+	return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
+}
+
+/*
+ * Either for a dom0 to write to the system console, or a domU with a
+ * debug version of Xen
+ */
+static int dom0_write_console(uint32_t vtermno, const char *str, int len)
+{
+	int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
+	if (rc < 0)
+		return rc;
+
+	return len;
+}
+
+static const struct hv_ops dom0_hvc_ops = {
+	.get_chars = dom0_read_console,
+	.put_chars = dom0_write_console,
+	.notifier_add = notifier_add_irq,
+	.notifier_del = notifier_del_irq,
+	.notifier_hangup = notifier_hangup_irq,
+};
+
+static int xen_hvm_console_init(void)
+{
+	int r;
+	uint64_t v = 0;
+	unsigned long gfn, flags;
+	struct xencons_info *info;
+
+	if (!xen_hvm_domain())
+		return -ENODEV;
+
+	info = vtermno_to_xencons(HVC_COOKIE);
+	if (!info) {
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+		if (!info)
+			return -ENOMEM;
+		spin_lock_init(&info->ring_lock);
+	} else if (info->intf != NULL) {
+		/* already configured */
+		return 0;
+	}
+	/*
+	 * If the toolstack (or the hypervisor) hasn't set these values, the
+	 * default value is 0. Even though gfn = 0 and evtchn = 0 are
+	 * theoretically correct values, in practice they never are and they
+	 * mean that a legacy toolstack hasn't initialized the pv console correctly.
+	 */
+	r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
+	if (r < 0 || v == 0)
+		goto err;
+	info->evtchn = v;
+	v = 0;
+	r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
+	if (r < 0 || v == 0)
+		goto err;
+	gfn = v;
+	info->intf = memremap(gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, MEMREMAP_WB);
+	if (info->intf == NULL)
+		goto err;
+	info->vtermno = HVC_COOKIE;
+
+	spin_lock_irqsave(&xencons_lock, flags);
+	list_add_tail(&info->list, &xenconsoles);
+	spin_unlock_irqrestore(&xencons_lock, flags);
+
+	return 0;
+err:
+	kfree(info);
+	return -ENODEV;
+}
+
+static int xencons_info_pv_init(struct xencons_info *info, int vtermno)
+{
+	spin_lock_init(&info->ring_lock);
+	info->evtchn = xen_start_info->console.domU.evtchn;
+	/* GFN == MFN for PV guest */
+	info->intf = gfn_to_virt(xen_start_info->console.domU.mfn);
+	info->vtermno = vtermno;
+
+	list_add_tail(&info->list, &xenconsoles);
+
+	return 0;
+}
+
+static int xen_pv_console_init(void)
+{
+	struct xencons_info *info;
+	unsigned long flags;
+
+	if (!xen_pv_domain())
+		return -ENODEV;
+
+	if (!xen_start_info->console.domU.evtchn)
+		return -ENODEV;
+
+	info = vtermno_to_xencons(HVC_COOKIE);
+	if (!info) {
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+		if (!info)
+			return -ENOMEM;
+	} else if (info->intf != NULL) {
+		/* already configured */
+		return 0;
+	}
+	spin_lock_irqsave(&xencons_lock, flags);
+	xencons_info_pv_init(info, HVC_COOKIE);
+	spin_unlock_irqrestore(&xencons_lock, flags);
+
+	return 0;
+}
+
+static int xen_initial_domain_console_init(void)
+{
+	struct xencons_info *info;
+	unsigned long flags;
+
+	if (!xen_initial_domain())
+		return -ENODEV;
+
+	info = vtermno_to_xencons(HVC_COOKIE);
+	if (!info) {
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+		if (!info)
+			return -ENOMEM;
+		spin_lock_init(&info->ring_lock);
+	}
+
+	info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false);
+	info->vtermno = HVC_COOKIE;
+
+	spin_lock_irqsave(&xencons_lock, flags);
+	list_add_tail(&info->list, &xenconsoles);
+	spin_unlock_irqrestore(&xencons_lock, flags);
+
+	return 0;
+}
+
+static void xen_console_update_evtchn(struct xencons_info *info)
+{
+	if (xen_hvm_domain()) {
+		uint64_t v = 0;
+		int err;
+
+		err = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
+		if (!err && v)
+			info->evtchn = v;
+	} else
+		info->evtchn = xen_start_info->console.domU.evtchn;
+}
+
+void xen_console_resume(void)
+{
+	struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
+	if (info != NULL && info->irq) {
+		if (!xen_initial_domain())
+			xen_console_update_evtchn(info);
+		rebind_evtchn_irq(info->evtchn, info->irq);
+	}
+}
+
+#ifdef CONFIG_HVC_XEN_FRONTEND
+static void xencons_disconnect_backend(struct xencons_info *info)
+{
+	if (info->hvc != NULL)
+		hvc_remove(info->hvc);
+	info->hvc = NULL;
+	if (info->irq > 0) {
+		evtchn_put(info->evtchn);
+		info->irq = 0;
+		info->evtchn = 0;
+	}
+	/* evtchn_put() will also close it so this is only an error path */
+	if (info->evtchn > 0)
+		xenbus_free_evtchn(info->xbdev, info->evtchn);
+	info->evtchn = 0;
+	if (info->gntref > 0)
+		gnttab_free_grant_references(info->gntref);
+	info->gntref = 0;
+}
+
+static void xencons_free(struct xencons_info *info)
+{
+	free_page((unsigned long)info->intf);
+	info->intf = NULL;
+	info->vtermno = 0;
+	kfree(info);
+}
+
+static int xen_console_remove(struct xencons_info *info)
+{
+	unsigned long flags;
+
+	xencons_disconnect_backend(info);
+	spin_lock_irqsave(&xencons_lock, flags);
+	list_del(&info->list);
+	spin_unlock_irqrestore(&xencons_lock, flags);
+	if (info->xbdev != NULL)
+		xencons_free(info);
+	else {
+		if (xen_hvm_domain())
+			iounmap(info->intf);
+		kfree(info);
+	}
+	return 0;
+}
+
+static void xencons_remove(struct xenbus_device *dev)
+{
+	xen_console_remove(dev_get_drvdata(&dev->dev));
+}
+
+static int xencons_connect_backend(struct xenbus_device *dev,
+				  struct xencons_info *info)
+{
+	int ret, evtchn, devid, ref, irq;
+	struct xenbus_transaction xbt;
+	grant_ref_t gref_head;
+
+	ret = xenbus_alloc_evtchn(dev, &evtchn);
+	if (ret)
+		return ret;
+	info->evtchn = evtchn;
+	irq = bind_evtchn_to_irq_lateeoi(evtchn);
+	if (irq < 0)
+		return irq;
+	info->irq = irq;
+	devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
+	info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
+			irq, &domU_hvc_ops, 256);
+	if (IS_ERR(info->hvc))
+		return PTR_ERR(info->hvc);
+	ret = gnttab_alloc_grant_references(1, &gref_head);
+	if (ret < 0)
+		return ret;
+	info->gntref = gref_head;
+	ref = gnttab_claim_grant_reference(&gref_head);
+	if (ref < 0)
+		return ref;
+	gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
+					virt_to_gfn(info->intf), 0);
+
+ again:
+	ret = xenbus_transaction_start(&xbt);
+	if (ret) {
+		xenbus_dev_fatal(dev, ret, "starting transaction");
+		return ret;
+	}
+	ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref);
+	if (ret)
+		goto error_xenbus;
+	ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
+			    evtchn);
+	if (ret)
+		goto error_xenbus;
+	ret = xenbus_transaction_end(xbt, 0);
+	if (ret) {
+		if (ret == -EAGAIN)
+			goto again;
+		xenbus_dev_fatal(dev, ret, "completing transaction");
+		return ret;
+	}
+
+	xenbus_switch_state(dev, XenbusStateInitialised);
+	return 0;
+
+ error_xenbus:
+	xenbus_transaction_end(xbt, 1);
+	xenbus_dev_fatal(dev, ret, "writing xenstore");
+	return ret;
+}
+
+static int xencons_probe(struct xenbus_device *dev,
+				  const struct xenbus_device_id *id)
+{
+	int ret, devid;
+	struct xencons_info *info;
+	unsigned long flags;
+
+	devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
+	if (devid == 0)
+		return -ENODEV;
+
+	info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+	spin_lock_init(&info->ring_lock);
+	dev_set_drvdata(&dev->dev, info);
+	info->xbdev = dev;
+	info->vtermno = xenbus_devid_to_vtermno(devid);
+	info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+	if (!info->intf)
+		goto error_nomem;
+
+	ret = xencons_connect_backend(dev, info);
+	if (ret < 0)
+		goto error;
+	spin_lock_irqsave(&xencons_lock, flags);
+	list_add_tail(&info->list, &xenconsoles);
+	spin_unlock_irqrestore(&xencons_lock, flags);
+
+	return 0;
+
+ error_nomem:
+	ret = -ENOMEM;
+	xenbus_dev_fatal(dev, ret, "allocating device memory");
+ error:
+	xencons_disconnect_backend(info);
+	xencons_free(info);
+	return ret;
+}
+
+static int xencons_resume(struct xenbus_device *dev)
+{
+	struct xencons_info *info = dev_get_drvdata(&dev->dev);
+
+	xencons_disconnect_backend(info);
+	memset(info->intf, 0, XEN_PAGE_SIZE);
+	return xencons_connect_backend(dev, info);
+}
+
+static void xencons_backend_changed(struct xenbus_device *dev,
+				   enum xenbus_state backend_state)
+{
+	switch (backend_state) {
+	case XenbusStateReconfiguring:
+	case XenbusStateReconfigured:
+	case XenbusStateInitialising:
+	case XenbusStateInitialised:
+	case XenbusStateUnknown:
+		break;
+
+	case XenbusStateInitWait:
+		break;
+
+	case XenbusStateConnected:
+		xenbus_switch_state(dev, XenbusStateConnected);
+		break;
+
+	case XenbusStateClosed:
+		if (dev->state == XenbusStateClosed)
+			break;
+		fallthrough;	/* Missed the backend's CLOSING state */
+	case XenbusStateClosing: {
+		struct xencons_info *info = dev_get_drvdata(&dev->dev);;
+
+		/*
+		 * Don't tear down the evtchn and grant ref before the other
+		 * end has disconnected, but do stop userspace from trying
+		 * to use the device before we allow the backend to close.
+		 */
+		if (info->hvc) {
+			hvc_remove(info->hvc);
+			info->hvc = NULL;
+		}
+
+		xenbus_frontend_closed(dev);
+		break;
+	}
+	}
+}
+
+static const struct xenbus_device_id xencons_ids[] = {
+	{ "console" },
+	{ "" }
+};
+
+static struct xenbus_driver xencons_driver = {
+	.name = "xenconsole",
+	.ids = xencons_ids,
+	.probe = xencons_probe,
+	.remove = xencons_remove,
+	.resume = xencons_resume,
+	.otherend_changed = xencons_backend_changed,
+	.not_essential = true,
+};
+#endif /* CONFIG_HVC_XEN_FRONTEND */
+
+static int __init xen_hvc_init(void)
+{
+	int r;
+	struct xencons_info *info;
+	const struct hv_ops *ops;
+
+	if (!xen_domain())
+		return -ENODEV;
+
+	if (xen_initial_domain()) {
+		ops = &dom0_hvc_ops;
+		r = xen_initial_domain_console_init();
+		if (r < 0)
+			goto register_fe;
+		info = vtermno_to_xencons(HVC_COOKIE);
+	} else {
+		ops = &domU_hvc_ops;
+		if (xen_hvm_domain())
+			r = xen_hvm_console_init();
+		else
+			r = xen_pv_console_init();
+		if (r < 0)
+			goto register_fe;
+
+		info = vtermno_to_xencons(HVC_COOKIE);
+		info->irq = bind_evtchn_to_irq_lateeoi(info->evtchn);
+	}
+	if (info->irq < 0)
+		info->irq = 0; /* NO_IRQ */
+	else
+		irq_set_noprobe(info->irq);
+
+	info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
+	if (IS_ERR(info->hvc)) {
+		unsigned long flags;
+
+		r = PTR_ERR(info->hvc);
+		spin_lock_irqsave(&xencons_lock, flags);
+		list_del(&info->list);
+		spin_unlock_irqrestore(&xencons_lock, flags);
+		if (info->irq)
+			evtchn_put(info->evtchn);
+		kfree(info);
+		return r;
+	}
+
+	r = 0;
+ register_fe:
+#ifdef CONFIG_HVC_XEN_FRONTEND
+	r = xenbus_register_frontend(&xencons_driver);
+#endif
+	return r;
+}
+device_initcall(xen_hvc_init);
+
+static int xen_cons_init(void)
+{
+	const struct hv_ops *ops;
+
+	if (!xen_domain())
+		return 0;
+
+	if (xen_initial_domain())
+		ops = &dom0_hvc_ops;
+	else {
+		int r;
+		ops = &domU_hvc_ops;
+
+		if (xen_hvm_domain())
+			r = xen_hvm_console_init();
+		else
+			r = xen_pv_console_init();
+		if (r < 0)
+			return r;
+	}
+
+	hvc_instantiate(HVC_COOKIE, 0, ops);
+	return 0;
+}
+console_initcall(xen_cons_init);
+
+#ifdef CONFIG_X86
+static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len)
+{
+	if (xen_cpuid_base())
+		outsb(0xe9, str, len);
+}
+#else
+static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) { }
+#endif
+
+#ifdef CONFIG_EARLY_PRINTK
+static int __init xenboot_console_setup(struct console *console, char *string)
+{
+	static struct xencons_info xenboot;
+
+	if (xen_initial_domain() || !xen_pv_domain())
+		return 0;
+
+	return xencons_info_pv_init(&xenboot, 0);
+}
+
+static void xenboot_write_console(struct console *console, const char *string,
+				  unsigned len)
+{
+	unsigned int linelen, off = 0;
+	const char *pos;
+
+	if (dom0_write_console(0, string, len) >= 0)
+		return;
+
+	if (!xen_pv_domain()) {
+		xen_hvm_early_write(0, string, len);
+		return;
+	}
+
+	if (domU_write_console(0, "(early) ", 8) < 0)
+		return;
+	while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
+		linelen = pos-string+off;
+		if (off + linelen > len)
+			break;
+		domU_write_console(0, string+off, linelen);
+		domU_write_console(0, "\r\n", 2);
+		off += linelen + 1;
+	}
+	if (off < len)
+		domU_write_console(0, string+off, len-off);
+}
+
+struct console xenboot_console = {
+	.name		= "xenboot",
+	.write		= xenboot_write_console,
+	.setup		= xenboot_console_setup,
+	.flags		= CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
+	.index		= -1,
+};
+#endif	/* CONFIG_EARLY_PRINTK */
+
+void xen_raw_console_write(const char *str)
+{
+	ssize_t len = strlen(str);
+	int rc = 0;
+
+	if (xen_domain()) {
+		rc = dom0_write_console(0, str, len);
+		if (rc != -ENOSYS || !xen_hvm_domain())
+			return;
+	}
+	xen_hvm_early_write(0, str, len);
+}
+
+void xen_raw_printk(const char *fmt, ...)
+{
+	static char buf[512];
+	va_list ap;
+
+	va_start(ap, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+
+	xen_raw_console_write(buf);
+}
+
+static void xenboot_earlycon_write(struct console *console,
+				  const char *string,
+				  unsigned len)
+{
+	dom0_write_console(0, string, len);
+}
+
+static int __init xenboot_earlycon_setup(struct earlycon_device *device,
+					    const char *opt)
+{
+	device->con->write = xenboot_earlycon_write;
+	return 0;
+}
+EARLYCON_DECLARE(xenboot, xenboot_earlycon_setup);
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
new file mode 100644
index 000000000..d29fdfe9d
--- /dev/null
+++ b/drivers/tty/hvc/hvcs.c
@@ -0,0 +1,1548 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IBM eServer Hypervisor Virtual Console Server Device Driver
+ * Copyright (C) 2003, 2004 IBM Corp.
+ *  Ryan S. Arnold (rsa@us.ibm.com)
+ *
+ * Author(s) :  Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * This is the device driver for the IBM Hypervisor Virtual Console Server,
+ * "hvcs".  The IBM hvcs provides a tty driver interface to allow Linux
+ * user space applications access to the system consoles of logically
+ * partitioned operating systems, e.g. Linux, running on the same partitioned
+ * Power5 ppc64 system.  Physical hardware consoles per partition are not
+ * practical on this hardware so system consoles are accessed by this driver
+ * using inter-partition firmware interfaces to virtual terminal devices.
+ *
+ * A vty is known to the HMC as a "virtual serial server adapter".  It is a
+ * virtual terminal device that is created by firmware upon partition creation
+ * to act as a partitioned OS's console device.
+ *
+ * Firmware dynamically (via hotplug) exposes vty-servers to a running ppc64
+ * Linux system upon their creation by the HMC or their exposure during boot.
+ * The non-user interactive backend of this driver is implemented as a vio
+ * device driver so that it can receive notification of vty-server lifetimes
+ * after it registers with the vio bus to handle vty-server probe and remove
+ * callbacks.
+ *
+ * Many vty-servers can be configured to connect to one vty, but a vty can
+ * only be actively connected to by a single vty-server, in any manner, at one
+ * time.  If the HMC is currently hosting the console for a target Linux
+ * partition; attempts to open the tty device to the partition's console using
+ * the hvcs on any partition will return -EBUSY with every open attempt until
+ * the HMC frees the connection between its vty-server and the desired
+ * partition's vty device.  Conversely, a vty-server may only be connected to
+ * a single vty at one time even though it may have several configured vty
+ * partner possibilities.
+ *
+ * Firmware does not provide notification of vty partner changes to this
+ * driver.  This means that an HMC Super Admin may add or remove partner vtys
+ * from a vty-server's partner list but the changes will not be signaled to
+ * the vty-server.  Firmware only notifies the driver when a vty-server is
+ * added or removed from the system.  To compensate for this deficiency, this
+ * driver implements a sysfs update attribute which provides a method for
+ * rescanning partner information upon a user's request.
+ *
+ * Each vty-server, prior to being exposed to this driver is reference counted
+ * using the 2.6 Linux kernel kref construct.
+ *
+ * For direction on installation and usage of this driver please reference
+ * Documentation/powerpc/hvcs.rst.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/major.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stat.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <asm/hvconsole.h>
+#include <asm/hvcserver.h>
+#include <linux/uaccess.h>
+#include <linux/termios_internal.h>
+#include <asm/vio.h>
+
+/*
+ * 1.3.0 -> 1.3.1 In hvcs_open memset(..,0x00,..) instead of memset(..,0x3F,00).
+ * Removed braces around single statements following conditionals.  Removed '=
+ * 0' after static int declarations since these default to zero.  Removed
+ * list_for_each_safe() and replaced with list_for_each_entry() in
+ * hvcs_get_by_index().  The 'safe' version is un-needed now that the driver is
+ * using spinlocks.  Changed spin_lock_irqsave() to spin_lock() when locking
+ * hvcs_structs_lock and hvcs_pi_lock since these are not touched in an int
+ * handler.  Initialized hvcs_structs_lock and hvcs_pi_lock to
+ * SPIN_LOCK_UNLOCKED at declaration time rather than in hvcs_module_init().
+ * Added spin_lock around list_del() in destroy_hvcs_struct() to protect the
+ * list traversals from a deletion.  Removed '= NULL' from pointer declaration
+ * statements since they are initialized NULL by default.  Removed wmb()
+ * instances from hvcs_try_write().  They probably aren't needed with locking in
+ * place.  Added check and cleanup for hvcs_pi_buff = kmalloc() in
+ * hvcs_module_init().  Exposed hvcs_struct.index via a sysfs attribute so that
+ * the coupling between /dev/hvcs* and a vty-server can be automatically
+ * determined.  Moved kobject_put() in hvcs_open outside of the
+ * spin_unlock_irqrestore().
+ *
+ * 1.3.1 -> 1.3.2 Changed method for determining hvcs_struct->index and had it
+ * align with how the tty layer always assigns the lowest index available.  This
+ * change resulted in a list of ints that denotes which indexes are available.
+ * Device additions and removals use the new hvcs_get_index() and
+ * hvcs_return_index() helper functions.  The list is created with
+ * hvsc_alloc_index_list() and it is destroyed with hvcs_free_index_list().
+ * Without these fixes hotplug vty-server adapter support goes crazy with this
+ * driver if the user removes a vty-server adapter.  Moved free_irq() outside of
+ * the hvcs_final_close() function in order to get it out of the spinlock.
+ * Rearranged hvcs_close().  Cleaned up some printks and did some housekeeping
+ * on the changelog.  Removed local CLC_LENGTH and used HVCS_CLC_LENGTH from
+ * arch/powerepc/include/asm/hvcserver.h
+ *
+ * 1.3.2 -> 1.3.3 Replaced yield() in hvcs_close() with tty_wait_until_sent() to
+ * prevent possible lockup with realtime scheduling as similarly pointed out by
+ * akpm in hvc_console.  Changed resulted in the removal of hvcs_final_close()
+ * to reorder cleanup operations and prevent discarding of pending data during
+ * an hvcs_close().  Removed spinlock protection of hvcs_struct data members in
+ * hvcs_write_room() and hvcs_chars_in_buffer() because they aren't needed.
+ */
+
+#define HVCS_DRIVER_VERSION "1.3.3"
+
+MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
+MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HVCS_DRIVER_VERSION);
+
+/*
+ * Wait this long per iteration while trying to push buffered data to the
+ * hypervisor before allowing the tty to complete a close operation.
+ */
+#define HVCS_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
+
+/*
+ * Since the Linux TTY code does not currently (2-04-2004) support dynamic
+ * addition of tty derived devices and we shouldn't allocate thousands of
+ * tty_device pointers when the number of vty-server & vty partner connections
+ * will most often be much lower than this, we'll arbitrarily allocate
+ * HVCS_DEFAULT_SERVER_ADAPTERS tty_structs and cdev's by default when we
+ * register the tty_driver. This can be overridden using an insmod parameter.
+ */
+#define HVCS_DEFAULT_SERVER_ADAPTERS	64
+
+/*
+ * The user can't insmod with more than HVCS_MAX_SERVER_ADAPTERS hvcs device
+ * nodes as a sanity check.  Theoretically there can be over 1 Billion
+ * vty-server & vty partner connections.
+ */
+#define HVCS_MAX_SERVER_ADAPTERS	1024
+
+/*
+ * We let Linux assign us a major number and we start the minors at zero.  There
+ * is no intuitive mapping between minor number and the target vty-server
+ * adapter except that each new vty-server adapter is always assigned to the
+ * smallest minor number available.
+ */
+#define HVCS_MINOR_START	0
+
+/*
+ * The hcall interface involves putting 8 chars into each of two registers.
+ * We load up those 2 registers (in arch/powerpc/platforms/pseries/hvconsole.c)
+ * by casting char[16] to long[2].  It would work without __ALIGNED__, but a 
+ * little (tiny) bit slower because an unaligned load is slower than aligned 
+ * load.
+ */
+#define __ALIGNED__	__attribute__((__aligned__(8)))
+
+/*
+ * How much data can firmware send with each hvc_put_chars()?  Maybe this
+ * should be moved into an architecture specific area.
+ */
+#define HVCS_BUFF_LEN	16
+
+/*
+ * This is the maximum amount of data we'll let the user send us (hvcs_write) at
+ * once in a chunk as a sanity check.
+ */
+#define HVCS_MAX_FROM_USER	4096
+
+/*
+ * Be careful when adding flags to this line discipline.  Don't add anything
+ * that will cause echoing or we'll go into recursive loop echoing chars back
+ * and forth with the console drivers.
+ */
+static const struct ktermios hvcs_tty_termios = {
+	.c_iflag = IGNBRK | IGNPAR,
+	.c_oflag = OPOST,
+	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
+	.c_cc = INIT_C_CC,
+	.c_ispeed = 38400,
+	.c_ospeed = 38400
+};
+
+/*
+ * This value is used to take the place of a command line parameter when the
+ * module is inserted.  It starts as -1 and stays as such if the user doesn't
+ * specify a module insmod parameter.  If they DO specify one then it is set to
+ * the value of the integer passed in.
+ */
+static int hvcs_parm_num_devs = -1;
+module_param(hvcs_parm_num_devs, int, 0);
+
+static const char hvcs_driver_name[] = "hvcs";
+static const char hvcs_device_node[] = "hvcs";
+
+/* Status of partner info rescan triggered via sysfs. */
+static int hvcs_rescan_status;
+
+static struct tty_driver *hvcs_tty_driver;
+
+/*
+ * In order to be somewhat sane this driver always associates the hvcs_struct
+ * index element with the numerically equal tty->index.  This means that a
+ * hotplugged vty-server adapter will always map to the lowest index valued
+ * device node.  If vty-servers were hotplug removed from the system and then
+ * new ones added the new vty-server may have the largest slot number of all
+ * the vty-server adapters in the partition but it may have the lowest dev node
+ * index of all the adapters due to the hole left by the hotplug removed
+ * adapter.  There are a set of functions provided to get the lowest index for
+ * a new device as well as return the index to the list.  This list is allocated
+ * with a number of elements equal to the number of device nodes requested when
+ * the module was inserted.
+ */
+static int *hvcs_index_list;
+
+/*
+ * How large is the list?  This is kept for traversal since the list is
+ * dynamically created.
+ */
+static int hvcs_index_count;
+
+/*
+ * Used by the khvcsd to pick up I/O operations when the kernel_thread is
+ * already awake but potentially shifted to TASK_INTERRUPTIBLE state.
+ */
+static int hvcs_kicked;
+
+/*
+ * Use by the kthread construct for task operations like waking the sleeping
+ * thread and stopping the kthread.
+ */
+static struct task_struct *hvcs_task;
+
+/*
+ * We allocate this for the use of all of the hvcs_structs when they fetch
+ * partner info.
+ */
+static unsigned long *hvcs_pi_buff;
+
+/* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */
+static DEFINE_SPINLOCK(hvcs_pi_lock);
+
+/* One vty-server per hvcs_struct */
+struct hvcs_struct {
+	struct tty_port port;
+	spinlock_t lock;
+
+	/*
+	 * This index identifies this hvcs device as the complement to a
+	 * specific tty index.
+	 */
+	unsigned int index;
+
+	/*
+	 * Used to tell the driver kernel_thread what operations need to take
+	 * place upon this hvcs_struct instance.
+	 */
+	int todo_mask;
+
+	/*
+	 * This buffer is required so that when hvcs_write_room() reports that
+	 * it can send HVCS_BUFF_LEN characters that it will buffer the full
+	 * HVCS_BUFF_LEN characters if need be.  This is essential for opost
+	 * writes since they do not do high level buffering and expect to be
+	 * able to send what the driver commits to sending buffering
+	 * [e.g. tab to space conversions in n_tty.c opost()].
+	 */
+	char buffer[HVCS_BUFF_LEN];
+	int chars_in_buffer;
+
+	/*
+	 * Any variable below is valid before a tty is connected and
+	 * stays valid after the tty is disconnected.  These shouldn't be
+	 * whacked until the kobject refcount reaches zero though some entries
+	 * may be changed via sysfs initiatives.
+	 */
+	int connected; /* is the vty-server currently connected to a vty? */
+	uint32_t p_unit_address; /* partner unit address */
+	uint32_t p_partition_ID; /* partner partition ID */
+	char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */
+	struct list_head next; /* list management */
+	struct vio_dev *vdev;
+	struct completion *destroyed;
+};
+
+static LIST_HEAD(hvcs_structs);
+static DEFINE_SPINLOCK(hvcs_structs_lock);
+static DEFINE_MUTEX(hvcs_init_mutex);
+
+static int hvcs_get_pi(struct hvcs_struct *hvcsd);
+static int hvcs_rescan_devices_list(void);
+
+static void hvcs_partner_free(struct hvcs_struct *hvcsd);
+
+static int hvcs_initialize(void);
+
+#define HVCS_SCHED_READ	0x00000001
+#define HVCS_QUICK_READ	0x00000002
+#define HVCS_TRY_WRITE	0x00000004
+#define HVCS_READ_MASK	(HVCS_SCHED_READ | HVCS_QUICK_READ)
+
+static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod)
+{
+	return dev_get_drvdata(&viod->dev);
+}
+/* The sysfs interface for the driver and devices */
+
+static ssize_t hvcs_partner_vtys_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct vio_dev *viod = to_vio_dev(dev);
+	struct hvcs_struct *hvcsd = from_vio_dev(viod);
+	unsigned long flags;
+	int retval;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	retval = sprintf(buf, "%X\n", hvcsd->p_unit_address);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return retval;
+}
+static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL);
+
+static ssize_t hvcs_partner_clcs_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct vio_dev *viod = to_vio_dev(dev);
+	struct hvcs_struct *hvcsd = from_vio_dev(viod);
+	unsigned long flags;
+	int retval;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return retval;
+}
+static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL);
+
+static ssize_t hvcs_current_vty_store(struct device *dev, struct device_attribute *attr, const char * buf,
+		size_t count)
+{
+	/*
+	 * Don't need this feature at the present time because firmware doesn't
+	 * yet support multiple partners.
+	 */
+	printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n");
+	return -EPERM;
+}
+
+static ssize_t hvcs_current_vty_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct vio_dev *viod = to_vio_dev(dev);
+	struct hvcs_struct *hvcsd = from_vio_dev(viod);
+	unsigned long flags;
+	int retval;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return retval;
+}
+
+static DEVICE_ATTR(current_vty,
+	S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store);
+
+static ssize_t hvcs_vterm_state_store(struct device *dev, struct device_attribute *attr, const char *buf,
+		size_t count)
+{
+	struct vio_dev *viod = to_vio_dev(dev);
+	struct hvcs_struct *hvcsd = from_vio_dev(viod);
+	unsigned long flags;
+
+	/* writing a '0' to this sysfs entry will result in the disconnect. */
+	if (simple_strtol(buf, NULL, 0) != 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	if (hvcsd->port.count > 0) {
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+		printk(KERN_INFO "HVCS: vterm state unchanged.  "
+				"The hvcs device node is still in use.\n");
+		return -EPERM;
+	}
+
+	if (hvcsd->connected == 0) {
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+		printk(KERN_INFO "HVCS: vterm state unchanged. The"
+				" vty-server is not connected to a vty.\n");
+		return -EPERM;
+	}
+
+	hvcs_partner_free(hvcsd);
+	printk(KERN_INFO "HVCS: Closed vty-server@%X and"
+			" partner vty@%X:%d connection.\n",
+			hvcsd->vdev->unit_address,
+			hvcsd->p_unit_address,
+			(uint32_t)hvcsd->p_partition_ID);
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return count;
+}
+
+static ssize_t hvcs_vterm_state_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct vio_dev *viod = to_vio_dev(dev);
+	struct hvcs_struct *hvcsd = from_vio_dev(viod);
+	unsigned long flags;
+	int retval;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	retval = sprintf(buf, "%d\n", hvcsd->connected);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return retval;
+}
+static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR,
+		hvcs_vterm_state_show, hvcs_vterm_state_store);
+
+static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct vio_dev *viod = to_vio_dev(dev);
+	struct hvcs_struct *hvcsd = from_vio_dev(viod);
+	unsigned long flags;
+	int retval;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	retval = sprintf(buf, "%d\n", hvcsd->index);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return retval;
+}
+
+static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL);
+
+static struct attribute *hvcs_dev_attrs[] = {
+	&dev_attr_partner_vtys.attr,
+	&dev_attr_partner_clcs.attr,
+	&dev_attr_current_vty.attr,
+	&dev_attr_vterm_state.attr,
+	&dev_attr_index.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(hvcs_dev);
+
+static ssize_t rescan_show(struct device_driver *ddp, char *buf)
+{
+	/* A 1 means it is updating, a 0 means it is done updating */
+	return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status);
+}
+
+static ssize_t rescan_store(struct device_driver *ddp, const char * buf,
+		size_t count)
+{
+	if ((simple_strtol(buf, NULL, 0) != 1)
+		&& (hvcs_rescan_status != 0))
+		return -EINVAL;
+
+	hvcs_rescan_status = 1;
+	printk(KERN_INFO "HVCS: rescanning partner info for all"
+		" vty-servers.\n");
+	hvcs_rescan_devices_list();
+	hvcs_rescan_status = 0;
+	return count;
+}
+
+static DRIVER_ATTR_RW(rescan);
+
+static struct attribute *hvcs_attrs[] = {
+	&driver_attr_rescan.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(hvcs);
+
+static void hvcs_kick(void)
+{
+	hvcs_kicked = 1;
+	wmb();
+	wake_up_process(hvcs_task);
+}
+
+static void hvcs_unthrottle(struct tty_struct *tty)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	hvcsd->todo_mask |= HVCS_SCHED_READ;
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	hvcs_kick();
+}
+
+static void hvcs_throttle(struct tty_struct *tty)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	vio_disable_interrupts(hvcsd->vdev);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+}
+
+/*
+ * If the device is being removed we don't have to worry about this interrupt
+ * handler taking any further interrupts because they are disabled which means
+ * the hvcs_struct will always be valid in this handler.
+ */
+static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance)
+{
+	struct hvcs_struct *hvcsd = dev_instance;
+
+	spin_lock(&hvcsd->lock);
+	vio_disable_interrupts(hvcsd->vdev);
+	hvcsd->todo_mask |= HVCS_SCHED_READ;
+	spin_unlock(&hvcsd->lock);
+	hvcs_kick();
+
+	return IRQ_HANDLED;
+}
+
+/* This function must be called with the hvcsd->lock held */
+static void hvcs_try_write(struct hvcs_struct *hvcsd)
+{
+	uint32_t unit_address = hvcsd->vdev->unit_address;
+	struct tty_struct *tty = hvcsd->port.tty;
+	int sent;
+
+	if (hvcsd->todo_mask & HVCS_TRY_WRITE) {
+		/* won't send partial writes */
+		sent = hvc_put_chars(unit_address,
+				&hvcsd->buffer[0],
+				hvcsd->chars_in_buffer );
+		if (sent > 0) {
+			hvcsd->chars_in_buffer = 0;
+			/* wmb(); */
+			hvcsd->todo_mask &= ~(HVCS_TRY_WRITE);
+			/* wmb(); */
+
+			/*
+			 * We are still obligated to deliver the data to the
+			 * hypervisor even if the tty has been closed because
+			 * we committed to delivering it.  But don't try to wake
+			 * a non-existent tty.
+			 */
+			if (tty) {
+				tty_wakeup(tty);
+			}
+		}
+	}
+}
+
+static int hvcs_io(struct hvcs_struct *hvcsd)
+{
+	uint32_t unit_address;
+	struct tty_struct *tty;
+	char buf[HVCS_BUFF_LEN] __ALIGNED__;
+	unsigned long flags;
+	int got = 0;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	unit_address = hvcsd->vdev->unit_address;
+	tty = hvcsd->port.tty;
+
+	hvcs_try_write(hvcsd);
+
+	if (!tty || tty_throttled(tty)) {
+		hvcsd->todo_mask &= ~(HVCS_READ_MASK);
+		goto bail;
+	} else if (!(hvcsd->todo_mask & (HVCS_READ_MASK)))
+		goto bail;
+
+	/* remove the read masks */
+	hvcsd->todo_mask &= ~(HVCS_READ_MASK);
+
+	if (tty_buffer_request_room(&hvcsd->port, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) {
+		got = hvc_get_chars(unit_address,
+				&buf[0],
+				HVCS_BUFF_LEN);
+		tty_insert_flip_string(&hvcsd->port, buf, got);
+	}
+
+	/* Give the TTY time to process the data we just sent. */
+	if (got)
+		hvcsd->todo_mask |= HVCS_QUICK_READ;
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	/* This is synch -- FIXME :js: it is not! */
+	if (got)
+		tty_flip_buffer_push(&hvcsd->port);
+	else {
+		/* Do this _after_ the flip_buffer_push */
+		spin_lock_irqsave(&hvcsd->lock, flags);
+		vio_enable_interrupts(hvcsd->vdev);
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+	}
+
+	return hvcsd->todo_mask;
+
+ bail:
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	return hvcsd->todo_mask;
+}
+
+static int khvcsd(void *unused)
+{
+	struct hvcs_struct *hvcsd;
+	int hvcs_todo_mask;
+
+	__set_current_state(TASK_RUNNING);
+
+	do {
+		hvcs_todo_mask = 0;
+		hvcs_kicked = 0;
+		wmb();
+
+		spin_lock(&hvcs_structs_lock);
+		list_for_each_entry(hvcsd, &hvcs_structs, next) {
+			hvcs_todo_mask |= hvcs_io(hvcsd);
+		}
+		spin_unlock(&hvcs_structs_lock);
+
+		/*
+		 * If any of the hvcs adapters want to try a write or quick read
+		 * don't schedule(), yield a smidgen then execute the hvcs_io
+		 * thread again for those that want the write.
+		 */
+		 if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) {
+			yield();
+			continue;
+		}
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!hvcs_kicked)
+			schedule();
+		__set_current_state(TASK_RUNNING);
+	} while (!kthread_should_stop());
+
+	return 0;
+}
+
+static const struct vio_device_id hvcs_driver_table[] = {
+	{"serial-server", "hvterm2"},
+	{ "", "" }
+};
+MODULE_DEVICE_TABLE(vio, hvcs_driver_table);
+
+static void hvcs_return_index(int index)
+{
+	/* Paranoia check */
+	if (!hvcs_index_list)
+		return;
+	if (index < 0 || index >= hvcs_index_count)
+		return;
+	if (hvcs_index_list[index] == -1)
+		return;
+	else
+		hvcs_index_list[index] = -1;
+}
+
+static void hvcs_destruct_port(struct tty_port *p)
+{
+	struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port);
+	struct vio_dev *vdev;
+	struct completion *comp;
+	unsigned long flags;
+
+	spin_lock(&hvcs_structs_lock);
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	comp = hvcsd->destroyed;
+	/* the list_del poisons the pointers */
+	list_del(&(hvcsd->next));
+
+	if (hvcsd->connected == 1) {
+		hvcs_partner_free(hvcsd);
+		printk(KERN_INFO "HVCS: Closed vty-server@%X and"
+				" partner vty@%X:%d connection.\n",
+				hvcsd->vdev->unit_address,
+				hvcsd->p_unit_address,
+				(uint32_t)hvcsd->p_partition_ID);
+	}
+	printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n",
+			hvcsd->vdev->unit_address);
+
+	vdev = hvcsd->vdev;
+	hvcsd->vdev = NULL;
+
+	hvcsd->p_unit_address = 0;
+	hvcsd->p_partition_ID = 0;
+	hvcsd->destroyed = NULL;
+	hvcs_return_index(hvcsd->index);
+	memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1);
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	spin_unlock(&hvcs_structs_lock);
+
+	kfree(hvcsd);
+	if (comp)
+		complete(comp);
+}
+
+static const struct tty_port_operations hvcs_port_ops = {
+	.destruct = hvcs_destruct_port,
+};
+
+static int hvcs_get_index(void)
+{
+	int i;
+	/* Paranoia check */
+	if (!hvcs_index_list) {
+		printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n");
+		return -EFAULT;
+	}
+	/* Find the numerically lowest first free index. */
+	for(i = 0; i < hvcs_index_count; i++) {
+		if (hvcs_index_list[i] == -1) {
+			hvcs_index_list[i] = 0;
+			return i;
+		}
+	}
+	return -1;
+}
+
+static int hvcs_probe(
+	struct vio_dev *dev,
+	const struct vio_device_id *id)
+{
+	struct hvcs_struct *hvcsd;
+	int index, rc;
+
+	if (!dev || !id) {
+		printk(KERN_ERR "HVCS: probed with invalid parameter.\n");
+		return -EPERM;
+	}
+
+	/* Make sure we are properly initialized */
+	rc = hvcs_initialize();
+	if (rc) {
+		pr_err("HVCS: Failed to initialize core driver.\n");
+		return rc;
+	}
+
+	/* early to avoid cleanup on failure */
+	index = hvcs_get_index();
+	if (index < 0) {
+		return -EFAULT;
+	}
+
+	hvcsd = kzalloc(sizeof(*hvcsd), GFP_KERNEL);
+	if (!hvcsd)
+		return -ENODEV;
+
+	tty_port_init(&hvcsd->port);
+	hvcsd->port.ops = &hvcs_port_ops;
+	spin_lock_init(&hvcsd->lock);
+
+	hvcsd->vdev = dev;
+	dev_set_drvdata(&dev->dev, hvcsd);
+
+	hvcsd->index = index;
+
+	/* hvcsd->index = ++hvcs_struct_count; */
+	hvcsd->chars_in_buffer = 0;
+	hvcsd->todo_mask = 0;
+	hvcsd->connected = 0;
+
+	/*
+	 * This will populate the hvcs_struct's partner info fields for the
+	 * first time.
+	 */
+	if (hvcs_get_pi(hvcsd)) {
+		printk(KERN_ERR "HVCS: Failed to fetch partner"
+			" info for vty-server@%X on device probe.\n",
+			hvcsd->vdev->unit_address);
+	}
+
+	/*
+	 * If a user app opens a tty that corresponds to this vty-server before
+	 * the hvcs_struct has been added to the devices list then the user app
+	 * will get -ENODEV.
+	 */
+	spin_lock(&hvcs_structs_lock);
+	list_add_tail(&(hvcsd->next), &hvcs_structs);
+	spin_unlock(&hvcs_structs_lock);
+
+	printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address);
+
+	/*
+	 * DON'T enable interrupts here because there is no user to receive the
+	 * data.
+	 */
+	return 0;
+}
+
+static void hvcs_remove(struct vio_dev *dev)
+{
+	struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev);
+	DECLARE_COMPLETION_ONSTACK(comp);
+	unsigned long flags;
+	struct tty_struct *tty;
+
+	/* By this time the vty-server won't be getting any more interrupts */
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	hvcsd->destroyed = &comp;
+	tty = tty_port_tty_get(&hvcsd->port);
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+	/*
+	 * The tty should always be valid at this time unless a
+	 * simultaneous tty close already cleaned up the hvcs_struct.
+	 */
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+
+	tty_port_put(&hvcsd->port);
+	wait_for_completion(&comp);
+	printk(KERN_INFO "HVCS: vty-server@%X removed from the"
+			" vio bus.\n", dev->unit_address);
+};
+
+static struct vio_driver hvcs_vio_driver = {
+	.id_table	= hvcs_driver_table,
+	.probe		= hvcs_probe,
+	.remove		= hvcs_remove,
+	.name		= hvcs_driver_name,
+	.driver = {
+		.groups = hvcs_groups,
+		.dev_groups = hvcs_dev_groups,
+	},
+};
+
+/* Only called from hvcs_get_pi please */
+static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd)
+{
+	hvcsd->p_unit_address = pi->unit_address;
+	hvcsd->p_partition_ID  = pi->partition_ID;
+
+	/* copy the null-term char too */
+	strscpy(hvcsd->p_location_code, pi->location_code,
+		sizeof(hvcsd->p_location_code));
+}
+
+/*
+ * Traverse the list and add the partner info that is found to the hvcs_struct
+ * struct entry. NOTE: At this time I know that partner info will return a
+ * single entry but in the future there may be multiple partner info entries per
+ * vty-server and you'll want to zero out that list and reset it.  If for some
+ * reason you have an old version of this driver but there IS more than one
+ * partner info then hvcsd->p_* will hold the last partner info data from the
+ * firmware query.  A good way to update this code would be to replace the three
+ * partner info fields in hvcs_struct with a list of hvcs_partner_info
+ * instances.
+ *
+ * This function must be called with the hvcsd->lock held.
+ */
+static int hvcs_get_pi(struct hvcs_struct *hvcsd)
+{
+	struct hvcs_partner_info *pi;
+	uint32_t unit_address = hvcsd->vdev->unit_address;
+	struct list_head head;
+	int retval;
+
+	spin_lock(&hvcs_pi_lock);
+	if (!hvcs_pi_buff) {
+		spin_unlock(&hvcs_pi_lock);
+		return -EFAULT;
+	}
+	retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff);
+	spin_unlock(&hvcs_pi_lock);
+	if (retval) {
+		printk(KERN_ERR "HVCS: Failed to fetch partner"
+			" info for vty-server@%x.\n", unit_address);
+		return retval;
+	}
+
+	/* nixes the values if the partner vty went away */
+	hvcsd->p_unit_address = 0;
+	hvcsd->p_partition_ID = 0;
+
+	list_for_each_entry(pi, &head, node)
+		hvcs_set_pi(pi, hvcsd);
+
+	hvcs_free_partner_info(&head);
+	return 0;
+}
+
+/*
+ * This function is executed by the driver "rescan" sysfs entry.  It shouldn't
+ * be executed elsewhere, in order to prevent deadlock issues.
+ */
+static int hvcs_rescan_devices_list(void)
+{
+	struct hvcs_struct *hvcsd;
+	unsigned long flags;
+
+	spin_lock(&hvcs_structs_lock);
+
+	list_for_each_entry(hvcsd, &hvcs_structs, next) {
+		spin_lock_irqsave(&hvcsd->lock, flags);
+		hvcs_get_pi(hvcsd);
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+	}
+
+	spin_unlock(&hvcs_structs_lock);
+
+	return 0;
+}
+
+/*
+ * Farm this off into its own function because it could be more complex once
+ * multiple partners support is added. This function should be called with
+ * the hvcsd->lock held.
+ */
+static int hvcs_has_pi(struct hvcs_struct *hvcsd)
+{
+	if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID))
+		return 0;
+	return 1;
+}
+
+/*
+ * NOTE: It is possible that the super admin removed a partner vty and then
+ * added a different vty as the new partner.
+ *
+ * This function must be called with the hvcsd->lock held.
+ */
+static int hvcs_partner_connect(struct hvcs_struct *hvcsd)
+{
+	int retval;
+	unsigned int unit_address = hvcsd->vdev->unit_address;
+
+	/*
+	 * If there wasn't any pi when the device was added it doesn't meant
+	 * there isn't any now.  This driver isn't notified when a new partner
+	 * vty is added to a vty-server so we discover changes on our own.
+	 * Please see comments in hvcs_register_connection() for justification
+	 * of this bizarre code.
+	 */
+	retval = hvcs_register_connection(unit_address,
+			hvcsd->p_partition_ID,
+			hvcsd->p_unit_address);
+	if (!retval) {
+		hvcsd->connected = 1;
+		return 0;
+	} else if (retval != -EINVAL)
+		return retval;
+
+	/*
+	 * As per the spec re-get the pi and try again if -EINVAL after the
+	 * first connection attempt.
+	 */
+	if (hvcs_get_pi(hvcsd))
+		return -ENOMEM;
+
+	if (!hvcs_has_pi(hvcsd))
+		return -ENODEV;
+
+	retval = hvcs_register_connection(unit_address,
+			hvcsd->p_partition_ID,
+			hvcsd->p_unit_address);
+	if (retval != -EINVAL) {
+		hvcsd->connected = 1;
+		return retval;
+	}
+
+	/*
+	 * EBUSY is the most likely scenario though the vty could have been
+	 * removed or there really could be an hcall error due to the parameter
+	 * data but thanks to ambiguous firmware return codes we can't really
+	 * tell.
+	 */
+	printk(KERN_INFO "HVCS: vty-server or partner"
+			" vty is busy.  Try again later.\n");
+	return -EBUSY;
+}
+
+/* This function must be called with the hvcsd->lock held */
+static void hvcs_partner_free(struct hvcs_struct *hvcsd)
+{
+	int retval;
+	do {
+		retval = hvcs_free_connection(hvcsd->vdev->unit_address);
+	} while (retval == -EBUSY);
+	hvcsd->connected = 0;
+}
+
+/* This helper function must be called WITHOUT the hvcsd->lock held */
+static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address,
+		unsigned int irq, struct vio_dev *vdev)
+{
+	unsigned long flags;
+	int rc;
+
+	/*
+	 * It is possible that the vty-server was removed between the time that
+	 * the conn was registered and now.
+	 */
+	rc = request_irq(irq, &hvcs_handle_interrupt, 0, "ibmhvcs", hvcsd);
+	if (!rc) {
+		/*
+		 * It is possible the vty-server was removed after the irq was
+		 * requested but before we have time to enable interrupts.
+		 */
+		if (vio_enable_interrupts(vdev) == H_SUCCESS)
+			return 0;
+		else {
+			printk(KERN_ERR "HVCS: int enable failed for"
+					" vty-server@%X.\n", unit_address);
+			free_irq(irq, hvcsd);
+		}
+	} else
+		printk(KERN_ERR "HVCS: irq req failed for"
+				" vty-server@%X.\n", unit_address);
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	hvcs_partner_free(hvcsd);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+	return rc;
+
+}
+
+/*
+ * This always increments the kref ref count if the call is successful.
+ * Please remember to dec when you are done with the instance.
+ *
+ * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when
+ * calling this function or you will get deadlock.
+ */
+static struct hvcs_struct *hvcs_get_by_index(int index)
+{
+	struct hvcs_struct *hvcsd;
+	unsigned long flags;
+
+	spin_lock(&hvcs_structs_lock);
+	list_for_each_entry(hvcsd, &hvcs_structs, next) {
+		spin_lock_irqsave(&hvcsd->lock, flags);
+		if (hvcsd->index == index) {
+			tty_port_get(&hvcsd->port);
+			spin_unlock_irqrestore(&hvcsd->lock, flags);
+			spin_unlock(&hvcs_structs_lock);
+			return hvcsd;
+		}
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+	}
+	spin_unlock(&hvcs_structs_lock);
+
+	return NULL;
+}
+
+static int hvcs_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct hvcs_struct *hvcsd;
+	struct vio_dev *vdev;
+	unsigned long unit_address, flags;
+	unsigned int irq;
+	int retval;
+
+	/*
+	 * Is there a vty-server that shares the same index?
+	 * This function increments the kref index.
+	 */
+	hvcsd = hvcs_get_by_index(tty->index);
+	if (!hvcsd) {
+		printk(KERN_WARNING "HVCS: open failed, no device associated"
+				" with tty->index %d.\n", tty->index);
+		return -ENODEV;
+	}
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	if (hvcsd->connected == 0) {
+		retval = hvcs_partner_connect(hvcsd);
+		if (retval) {
+			spin_unlock_irqrestore(&hvcsd->lock, flags);
+			printk(KERN_WARNING "HVCS: partner connect failed.\n");
+			goto err_put;
+		}
+	}
+
+	hvcsd->port.count = 0;
+	hvcsd->port.tty = tty;
+	tty->driver_data = hvcsd;
+
+	memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN);
+
+	/*
+	 * Save these in the spinlock for the enable operations that need them
+	 * outside of the spinlock.
+	 */
+	irq = hvcsd->vdev->irq;
+	vdev = hvcsd->vdev;
+	unit_address = hvcsd->vdev->unit_address;
+
+	hvcsd->todo_mask |= HVCS_SCHED_READ;
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+	/*
+	 * This must be done outside of the spinlock because it requests irqs
+	 * and will grab the spinlock and free the connection if it fails.
+	 */
+	retval = hvcs_enable_device(hvcsd, unit_address, irq, vdev);
+	if (retval) {
+		printk(KERN_WARNING "HVCS: enable device failed.\n");
+		goto err_put;
+	}
+
+	retval = tty_port_install(&hvcsd->port, driver, tty);
+	if (retval)
+		goto err_irq;
+
+	return 0;
+err_irq:
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	vio_disable_interrupts(hvcsd->vdev);
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+	free_irq(irq, hvcsd);
+err_put:
+	tty_port_put(&hvcsd->port);
+
+	return retval;
+}
+
+/*
+ * This is invoked via the tty_open interface when a user app connects to the
+ * /dev node.
+ */
+static int hvcs_open(struct tty_struct *tty, struct file *filp)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	hvcsd->port.count++;
+	hvcsd->todo_mask |= HVCS_SCHED_READ;
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+	hvcs_kick();
+
+	printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n",
+		hvcsd->vdev->unit_address );
+
+	return 0;
+}
+
+static void hvcs_close(struct tty_struct *tty, struct file *filp)
+{
+	struct hvcs_struct *hvcsd;
+	unsigned long flags;
+	int irq;
+
+	/*
+	 * Is someone trying to close the file associated with this device after
+	 * we have hung up?  If so tty->driver_data wouldn't be valid.
+	 */
+	if (tty_hung_up_p(filp))
+		return;
+
+	/*
+	 * No driver_data means that this close was probably issued after a
+	 * failed hvcs_open by the tty layer's release_dev() api and we can just
+	 * exit cleanly.
+	 */
+	if (!tty->driver_data)
+		return;
+
+	hvcsd = tty->driver_data;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+	if (hvcsd->port.count == 0) {
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+		return;
+	} else if (--hvcsd->port.count == 0) {
+
+		vio_disable_interrupts(hvcsd->vdev);
+
+		/*
+		 * NULL this early so that the kernel_thread doesn't try to
+		 * execute any operations on the TTY even though it is obligated
+		 * to deliver any pending I/O to the hypervisor.
+		 */
+		hvcsd->port.tty = NULL;
+
+		irq = hvcsd->vdev->irq;
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+		tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
+
+		free_irq(irq, hvcsd);
+		return;
+	} else if (hvcsd->port.count < 0) {
+		printk(KERN_ERR "HVCS: vty-server@%X open_count: %d is mismanaged.\n",
+		hvcsd->vdev->unit_address, hvcsd->port.count);
+	}
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+}
+
+static void hvcs_cleanup(struct tty_struct * tty)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+
+	/*
+	 * This line is important because it tells hvcs_open that this
+	 * device needs to be re-configured the next time hvcs_open is
+	 * called.
+	 */
+	tty->driver_data = NULL;
+
+	tty_port_put(&hvcsd->port);
+}
+
+static void hvcs_hangup(struct tty_struct * tty)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+	unsigned long flags;
+	int irq;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	/*
+	 * Don't kref put inside the spinlock because the destruction
+	 * callback may use the spinlock and it may get called before the
+	 * spinlock has been released.
+	 */
+	vio_disable_interrupts(hvcsd->vdev);
+
+	hvcsd->todo_mask = 0;
+	hvcsd->port.tty = NULL;
+	hvcsd->port.count = 0;
+
+	/* This will drop any buffered data on the floor which is OK in a hangup
+	 * scenario. */
+	memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN);
+	hvcsd->chars_in_buffer = 0;
+
+	irq = hvcsd->vdev->irq;
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+	free_irq(irq, hvcsd);
+}
+
+/*
+ * NOTE: This is almost always from_user since user level apps interact with the
+ * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by
+ * hvcs_remove (which removes the target device and executes tty_hangup()) that
+ * tty_hangup will allow hvcs_write time to complete execution before it
+ * terminates our device.
+ */
+static ssize_t hvcs_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+	unsigned int unit_address;
+	const unsigned char *charbuf;
+	unsigned long flags;
+	size_t total_sent = 0;
+	size_t tosend = 0;
+	int result = 0;
+
+	/*
+	 * If they don't check the return code off of their open they may
+	 * attempt this even if there is no connected device.
+	 */
+	if (!hvcsd)
+		return -ENODEV;
+
+	/* Reasonable size to prevent user level flooding */
+	if (count > HVCS_MAX_FROM_USER) {
+		printk(KERN_WARNING "HVCS write: count being truncated to"
+				" HVCS_MAX_FROM_USER.\n");
+		count = HVCS_MAX_FROM_USER;
+	}
+
+	charbuf = buf;
+
+	spin_lock_irqsave(&hvcsd->lock, flags);
+
+	/*
+	 * Somehow an open succeeded but the device was removed or the
+	 * connection terminated between the vty-server and partner vty during
+	 * the middle of a write operation?  This is a crummy place to do this
+	 * but we want to keep it all in the spinlock.
+	 */
+	if (hvcsd->port.count <= 0) {
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+		return -ENODEV;
+	}
+
+	unit_address = hvcsd->vdev->unit_address;
+
+	while (count > 0) {
+		tosend = min_t(size_t, count,
+			       (HVCS_BUFF_LEN - hvcsd->chars_in_buffer));
+		/*
+		 * No more space, this probably means that the last call to
+		 * hvcs_write() didn't succeed and the buffer was filled up.
+		 */
+		if (!tosend)
+			break;
+
+		memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer],
+				&charbuf[total_sent],
+				tosend);
+
+		hvcsd->chars_in_buffer += tosend;
+
+		result = 0;
+
+		/*
+		 * If this is true then we don't want to try writing to the
+		 * hypervisor because that is the kernel_threads job now.  We'll
+		 * just add to the buffer.
+		 */
+		if (!(hvcsd->todo_mask & HVCS_TRY_WRITE))
+			/* won't send partial writes */
+			result = hvc_put_chars(unit_address,
+					&hvcsd->buffer[0],
+					hvcsd->chars_in_buffer);
+
+		/*
+		 * Since we know we have enough room in hvcsd->buffer for
+		 * tosend we record that it was sent regardless of whether the
+		 * hypervisor actually took it because we have it buffered.
+		 */
+		total_sent+=tosend;
+		count-=tosend;
+		if (result == 0) {
+			hvcsd->todo_mask |= HVCS_TRY_WRITE;
+			hvcs_kick();
+			break;
+		}
+
+		hvcsd->chars_in_buffer = 0;
+		/*
+		 * Test after the chars_in_buffer reset otherwise this could
+		 * deadlock our writes if hvc_put_chars fails.
+		 */
+		if (result < 0)
+			break;
+	}
+
+	spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+	if (result == -1)
+		return -EIO;
+	else
+		return total_sent;
+}
+
+/*
+ * This is really asking how much can we guarantee that we can send or that we
+ * absolutely WILL BUFFER if we can't send it.  This driver MUST honor the
+ * return value, hence the reason for hvcs_struct buffering.
+ */
+static unsigned int hvcs_write_room(struct tty_struct *tty)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+
+	if (!hvcsd || hvcsd->port.count <= 0)
+		return 0;
+
+	return HVCS_BUFF_LEN - hvcsd->chars_in_buffer;
+}
+
+static unsigned int hvcs_chars_in_buffer(struct tty_struct *tty)
+{
+	struct hvcs_struct *hvcsd = tty->driver_data;
+
+	return hvcsd->chars_in_buffer;
+}
+
+static const struct tty_operations hvcs_ops = {
+	.install = hvcs_install,
+	.open = hvcs_open,
+	.close = hvcs_close,
+	.cleanup = hvcs_cleanup,
+	.hangup = hvcs_hangup,
+	.write = hvcs_write,
+	.write_room = hvcs_write_room,
+	.chars_in_buffer = hvcs_chars_in_buffer,
+	.unthrottle = hvcs_unthrottle,
+	.throttle = hvcs_throttle,
+};
+
+static int hvcs_alloc_index_list(int n)
+{
+	int i;
+
+	hvcs_index_list = kmalloc_array(n, sizeof(hvcs_index_count),
+					GFP_KERNEL);
+	if (!hvcs_index_list)
+		return -ENOMEM;
+	hvcs_index_count = n;
+	for (i = 0; i < hvcs_index_count; i++)
+		hvcs_index_list[i] = -1;
+	return 0;
+}
+
+static void hvcs_free_index_list(void)
+{
+	/* Paranoia check to be thorough. */
+	kfree(hvcs_index_list);
+	hvcs_index_list = NULL;
+	hvcs_index_count = 0;
+}
+
+static int hvcs_initialize(void)
+{
+	int rc, num_ttys_to_alloc;
+
+	mutex_lock(&hvcs_init_mutex);
+	if (hvcs_task) {
+		mutex_unlock(&hvcs_init_mutex);
+		return 0;
+	}
+
+	/* Has the user specified an overload with an insmod param? */
+	if (hvcs_parm_num_devs <= 0 ||
+		(hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) {
+		num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS;
+	} else
+		num_ttys_to_alloc = hvcs_parm_num_devs;
+
+	hvcs_tty_driver = tty_alloc_driver(num_ttys_to_alloc,
+			TTY_DRIVER_REAL_RAW);
+	if (IS_ERR(hvcs_tty_driver)) {
+		mutex_unlock(&hvcs_init_mutex);
+		return PTR_ERR(hvcs_tty_driver);
+	}
+
+	if (hvcs_alloc_index_list(num_ttys_to_alloc)) {
+		rc = -ENOMEM;
+		goto index_fail;
+	}
+
+	hvcs_tty_driver->driver_name = hvcs_driver_name;
+	hvcs_tty_driver->name = hvcs_device_node;
+
+	/*
+	 * We'll let the system assign us a major number, indicated by leaving
+	 * it blank.
+	 */
+
+	hvcs_tty_driver->minor_start = HVCS_MINOR_START;
+	hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
+
+	/*
+	 * We role our own so that we DONT ECHO.  We can't echo because the
+	 * device we are connecting to already echoes by default and this would
+	 * throw us into a horrible recursive echo-echo-echo loop.
+	 */
+	hvcs_tty_driver->init_termios = hvcs_tty_termios;
+
+	tty_set_operations(hvcs_tty_driver, &hvcs_ops);
+
+	/*
+	 * The following call will result in sysfs entries that denote the
+	 * dynamically assigned major and minor numbers for our devices.
+	 */
+	if (tty_register_driver(hvcs_tty_driver)) {
+		printk(KERN_ERR "HVCS: registration as a tty driver failed.\n");
+		rc = -EIO;
+		goto register_fail;
+	}
+
+	hvcs_pi_buff = (unsigned long *) __get_free_page(GFP_KERNEL);
+	if (!hvcs_pi_buff) {
+		rc = -ENOMEM;
+		goto buff_alloc_fail;
+	}
+
+	hvcs_task = kthread_run(khvcsd, NULL, "khvcsd");
+	if (IS_ERR(hvcs_task)) {
+		printk(KERN_ERR "HVCS: khvcsd creation failed.\n");
+		rc = -EIO;
+		goto kthread_fail;
+	}
+	mutex_unlock(&hvcs_init_mutex);
+	return 0;
+
+kthread_fail:
+	free_page((unsigned long)hvcs_pi_buff);
+buff_alloc_fail:
+	tty_unregister_driver(hvcs_tty_driver);
+register_fail:
+	hvcs_free_index_list();
+index_fail:
+	tty_driver_kref_put(hvcs_tty_driver);
+	hvcs_tty_driver = NULL;
+	mutex_unlock(&hvcs_init_mutex);
+	return rc;
+}
+
+static int __init hvcs_module_init(void)
+{
+	int rc = vio_register_driver(&hvcs_vio_driver);
+	if (rc) {
+		printk(KERN_ERR "HVCS: can't register vio driver\n");
+		return rc;
+	}
+
+	pr_info("HVCS: Driver registered.\n");
+
+	return 0;
+}
+
+static void __exit hvcs_module_exit(void)
+{
+	/*
+	 * This driver receives hvcs_remove callbacks for each device upon
+	 * module removal.
+	 */
+	vio_unregister_driver(&hvcs_vio_driver);
+	if (!hvcs_task)
+		return;
+
+	/*
+	 * This synchronous operation  will wake the khvcsd kthread if it is
+	 * asleep and will return when khvcsd has terminated.
+	 */
+	kthread_stop(hvcs_task);
+
+	spin_lock(&hvcs_pi_lock);
+	free_page((unsigned long)hvcs_pi_buff);
+	hvcs_pi_buff = NULL;
+	spin_unlock(&hvcs_pi_lock);
+
+	tty_unregister_driver(hvcs_tty_driver);
+
+	hvcs_free_index_list();
+
+	tty_driver_kref_put(hvcs_tty_driver);
+
+	printk(KERN_INFO "HVCS: driver module removed.\n");
+}
+
+module_init(hvcs_module_init);
+module_exit(hvcs_module_exit);
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
new file mode 100644
index 000000000..a94068bce
--- /dev/null
+++ b/drivers/tty/hvc/hvsi.c
@@ -0,0 +1,1224 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM
+ */
+
+/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS
+ * and the service processor on IBM pSeries servers. On these servers, there
+ * are no serial ports under the OS's control, and sometimes there is no other
+ * console available either. However, the service processor has two standard
+ * serial ports, so this over-complicated protocol allows the OS to control
+ * those ports by proxy.
+ *
+ * Besides data, the procotol supports the reading/writing of the serial
+ * port's DTR line, and the reading of the CD line. This is to allow the OS to
+ * control a modem attached to the service processor's serial port. Note that
+ * the OS cannot change the speed of the port through this protocol.
+ */
+
+#undef DEBUG
+
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/major.h>
+#include <linux/kernel.h>
+#include <linux/of_irq.h>
+#include <linux/spinlock.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <asm/hvcall.h>
+#include <asm/hvconsole.h>
+#include <linux/uaccess.h>
+#include <asm/vio.h>
+#include <asm/param.h>
+#include <asm/hvsi.h>
+
+#define HVSI_MAJOR	229
+#define HVSI_MINOR	128
+#define MAX_NR_HVSI_CONSOLES 4
+
+#define HVSI_TIMEOUT (5*HZ)
+#define HVSI_VERSION 1
+#define HVSI_MAX_PACKET 256
+#define HVSI_MAX_READ 16
+#define HVSI_MAX_OUTGOING_DATA 12
+#define N_OUTBUF 12
+
+/*
+ * we pass data via two 8-byte registers, so we would like our char arrays
+ * properly aligned for those loads.
+ */
+#define __ALIGNED__	__attribute__((__aligned__(sizeof(long))))
+
+struct hvsi_struct {
+	struct tty_port port;
+	struct delayed_work writer;
+	struct work_struct handshaker;
+	wait_queue_head_t emptyq; /* woken when outbuf is emptied */
+	wait_queue_head_t stateq; /* woken when HVSI state changes */
+	spinlock_t lock;
+	int index;
+	uint8_t throttle_buf[128];
+	uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
+	/* inbuf is for packet reassembly. leave a little room for leftovers. */
+	uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
+	uint8_t *inbuf_end;
+	int n_throttle;
+	int n_outbuf;
+	uint32_t vtermno;
+	uint32_t virq;
+	atomic_t seqno; /* HVSI packet sequence number */
+	uint16_t mctrl;
+	uint8_t state;  /* HVSI protocol state */
+	uint8_t flags;
+#ifdef CONFIG_MAGIC_SYSRQ
+	uint8_t sysrq;
+#endif /* CONFIG_MAGIC_SYSRQ */
+};
+static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
+
+static struct tty_driver *hvsi_driver;
+static int hvsi_count;
+static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
+
+enum HVSI_PROTOCOL_STATE {
+	HVSI_CLOSED,
+	HVSI_WAIT_FOR_VER_RESPONSE,
+	HVSI_WAIT_FOR_VER_QUERY,
+	HVSI_OPEN,
+	HVSI_WAIT_FOR_MCTRL_RESPONSE,
+	HVSI_FSP_DIED,
+};
+#define HVSI_CONSOLE 0x1
+
+static inline int is_console(struct hvsi_struct *hp)
+{
+	return hp->flags & HVSI_CONSOLE;
+}
+
+static inline int is_open(struct hvsi_struct *hp)
+{
+	/* if we're waiting for an mctrl then we're already open */
+	return (hp->state == HVSI_OPEN)
+			|| (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
+}
+
+static inline void print_state(struct hvsi_struct *hp)
+{
+#ifdef DEBUG
+	static const char *state_names[] = {
+		"HVSI_CLOSED",
+		"HVSI_WAIT_FOR_VER_RESPONSE",
+		"HVSI_WAIT_FOR_VER_QUERY",
+		"HVSI_OPEN",
+		"HVSI_WAIT_FOR_MCTRL_RESPONSE",
+		"HVSI_FSP_DIED",
+	};
+	const char *name = (hp->state < ARRAY_SIZE(state_names))
+		? state_names[hp->state] : "UNKNOWN";
+
+	pr_debug("hvsi%i: state = %s\n", hp->index, name);
+#endif /* DEBUG */
+}
+
+static inline void __set_state(struct hvsi_struct *hp, int state)
+{
+	hp->state = state;
+	print_state(hp);
+	wake_up_all(&hp->stateq);
+}
+
+static inline void set_state(struct hvsi_struct *hp, int state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&hp->lock, flags);
+	__set_state(hp, state);
+	spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+static inline int len_packet(const uint8_t *packet)
+{
+	return (int)((struct hvsi_header *)packet)->len;
+}
+
+static inline int is_header(const uint8_t *packet)
+{
+	struct hvsi_header *header = (struct hvsi_header *)packet;
+	return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
+}
+
+static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
+{
+	if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
+		return 0; /* don't even have the packet header */
+
+	if (hp->inbuf_end < (packet + len_packet(packet)))
+		return 0; /* don't have the rest of the packet */
+
+	return 1;
+}
+
+/* shift remaining bytes in packetbuf down */
+static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
+{
+	int remaining = (int)(hp->inbuf_end - read_to);
+
+	pr_debug("%s: %i chars remain\n", __func__, remaining);
+
+	if (read_to != hp->inbuf)
+		memmove(hp->inbuf, read_to, remaining);
+
+	hp->inbuf_end = hp->inbuf + remaining;
+}
+
+#ifdef DEBUG
+#define dbg_dump_packet(packet) dump_packet(packet)
+#define dbg_dump_hex(data, len) dump_hex(data, len)
+#else
+#define dbg_dump_packet(packet) do { } while (0)
+#define dbg_dump_hex(data, len) do { } while (0)
+#endif
+
+static void dump_hex(const uint8_t *data, int len)
+{
+	int i;
+
+	printk("    ");
+	for (i=0; i < len; i++)
+		printk("%.2x", data[i]);
+
+	printk("\n    ");
+	for (i=0; i < len; i++) {
+		if (isprint(data[i]))
+			printk("%c", data[i]);
+		else
+			printk(".");
+	}
+	printk("\n");
+}
+
+static void dump_packet(uint8_t *packet)
+{
+	struct hvsi_header *header = (struct hvsi_header *)packet;
+
+	printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
+			header->seqno);
+
+	dump_hex(packet, header->len);
+}
+
+static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
+{
+	unsigned long got;
+
+	got = hvc_get_chars(hp->vtermno, buf, count);
+
+	return got;
+}
+
+static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
+	struct tty_struct *tty, struct hvsi_struct **to_handshake)
+{
+	struct hvsi_control *header = (struct hvsi_control *)packet;
+
+	switch (be16_to_cpu(header->verb)) {
+		case VSV_MODEM_CTL_UPDATE:
+			if ((be32_to_cpu(header->word) & HVSI_TSCD) == 0) {
+				/* CD went away; no more connection */
+				pr_debug("hvsi%i: CD dropped\n", hp->index);
+				hp->mctrl &= TIOCM_CD;
+				if (tty && !C_CLOCAL(tty))
+					tty_hangup(tty);
+			}
+			break;
+		case VSV_CLOSE_PROTOCOL:
+			pr_debug("hvsi%i: service processor came back\n", hp->index);
+			if (hp->state != HVSI_CLOSED) {
+				*to_handshake = hp;
+			}
+			break;
+		default:
+			printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
+				hp->index);
+			dump_packet(packet);
+			break;
+	}
+}
+
+static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
+{
+	struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
+	uint32_t mctrl_word;
+
+	switch (hp->state) {
+		case HVSI_WAIT_FOR_VER_RESPONSE:
+			__set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
+			break;
+		case HVSI_WAIT_FOR_MCTRL_RESPONSE:
+			hp->mctrl = 0;
+			mctrl_word = be32_to_cpu(resp->u.mctrl_word);
+			if (mctrl_word & HVSI_TSDTR)
+				hp->mctrl |= TIOCM_DTR;
+			if (mctrl_word & HVSI_TSCD)
+				hp->mctrl |= TIOCM_CD;
+			__set_state(hp, HVSI_OPEN);
+			break;
+		default:
+			printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
+			dump_packet(packet);
+			break;
+	}
+}
+
+/* respond to service processor's version query */
+static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
+{
+	struct hvsi_query_response packet __ALIGNED__;
+	int wrote;
+
+	packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
+	packet.hdr.len = sizeof(struct hvsi_query_response);
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
+	packet.u.version = HVSI_VERSION;
+	packet.query_seqno = cpu_to_be16(query_seqno+1);
+
+	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+	wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+	if (wrote != packet.hdr.len) {
+		printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
+			hp->index);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
+{
+	struct hvsi_query *query = (struct hvsi_query *)packet;
+
+	switch (hp->state) {
+		case HVSI_WAIT_FOR_VER_QUERY:
+			hvsi_version_respond(hp, be16_to_cpu(query->hdr.seqno));
+			__set_state(hp, HVSI_OPEN);
+			break;
+		default:
+			printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
+			dump_packet(packet);
+			break;
+	}
+}
+
+static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
+{
+	int i;
+
+	for (i=0; i < len; i++) {
+		char c = buf[i];
+#ifdef CONFIG_MAGIC_SYSRQ
+		if (c == '\0') {
+			hp->sysrq = 1;
+			continue;
+		} else if (hp->sysrq) {
+			handle_sysrq(c);
+			hp->sysrq = 0;
+			continue;
+		}
+#endif /* CONFIG_MAGIC_SYSRQ */
+		tty_insert_flip_char(&hp->port, c, 0);
+	}
+}
+
+/*
+ * We could get 252 bytes of data at once here. But the tty layer only
+ * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
+ * it. Accordingly we won't send more than 128 bytes at a time to the flip
+ * buffer, which will give the tty buffer a chance to throttle us. Should the
+ * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
+ * revisited.
+ */
+#define TTY_THRESHOLD_THROTTLE 128
+static bool hvsi_recv_data(struct hvsi_struct *hp, const uint8_t *packet)
+{
+	const struct hvsi_header *header = (const struct hvsi_header *)packet;
+	const uint8_t *data = packet + sizeof(struct hvsi_header);
+	int datalen = header->len - sizeof(struct hvsi_header);
+	int overflow = datalen - TTY_THRESHOLD_THROTTLE;
+
+	pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
+
+	if (datalen == 0)
+		return false;
+
+	if (overflow > 0) {
+		pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
+		datalen = TTY_THRESHOLD_THROTTLE;
+	}
+
+	hvsi_insert_chars(hp, data, datalen);
+
+	if (overflow > 0) {
+		/*
+		 * we still have more data to deliver, so we need to save off the
+		 * overflow and send it later
+		 */
+		pr_debug("%s: deferring overflow\n", __func__);
+		memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
+		hp->n_throttle = overflow;
+	}
+
+	return true;
+}
+
+/*
+ * Returns true/false indicating data successfully read from hypervisor.
+ * Used both to get packets for tty connections and to advance the state
+ * machine during console handshaking (in which case tty = NULL and we ignore
+ * incoming data).
+ */
+static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct *tty,
+		struct hvsi_struct **handshake)
+{
+	uint8_t *packet = hp->inbuf;
+	int chunklen;
+	bool flip = false;
+
+	*handshake = NULL;
+
+	chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
+	if (chunklen == 0) {
+		pr_debug("%s: 0-length read\n", __func__);
+		return 0;
+	}
+
+	pr_debug("%s: got %i bytes\n", __func__, chunklen);
+	dbg_dump_hex(hp->inbuf_end, chunklen);
+
+	hp->inbuf_end += chunklen;
+
+	/* handle all completed packets */
+	while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
+		struct hvsi_header *header = (struct hvsi_header *)packet;
+
+		if (!is_header(packet)) {
+			printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
+			/* skip bytes until we find a header or run out of data */
+			while ((packet < hp->inbuf_end) && (!is_header(packet)))
+				packet++;
+			continue;
+		}
+
+		pr_debug("%s: handling %i-byte packet\n", __func__,
+				len_packet(packet));
+		dbg_dump_packet(packet);
+
+		switch (header->type) {
+			case VS_DATA_PACKET_HEADER:
+				if (!is_open(hp))
+					break;
+				flip = hvsi_recv_data(hp, packet);
+				break;
+			case VS_CONTROL_PACKET_HEADER:
+				hvsi_recv_control(hp, packet, tty, handshake);
+				break;
+			case VS_QUERY_RESPONSE_PACKET_HEADER:
+				hvsi_recv_response(hp, packet);
+				break;
+			case VS_QUERY_PACKET_HEADER:
+				hvsi_recv_query(hp, packet);
+				break;
+			default:
+				printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
+						hp->index, header->type);
+				dump_packet(packet);
+				break;
+		}
+
+		packet += len_packet(packet);
+
+		if (*handshake) {
+			pr_debug("%s: handshake\n", __func__);
+			break;
+		}
+	}
+
+	compact_inbuf(hp, packet);
+
+	if (flip)
+		tty_flip_buffer_push(&hp->port);
+
+	return 1;
+}
+
+static void hvsi_send_overflow(struct hvsi_struct *hp)
+{
+	pr_debug("%s: delivering %i bytes overflow\n", __func__,
+			hp->n_throttle);
+
+	hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
+	hp->n_throttle = 0;
+}
+
+/*
+ * must get all pending data because we only get an irq on empty->non-empty
+ * transition
+ */
+static irqreturn_t hvsi_interrupt(int irq, void *arg)
+{
+	struct hvsi_struct *hp = (struct hvsi_struct *)arg;
+	struct hvsi_struct *handshake;
+	struct tty_struct *tty;
+	unsigned long flags;
+	int again = 1;
+
+	pr_debug("%s\n", __func__);
+
+	tty = tty_port_tty_get(&hp->port);
+
+	while (again) {
+		spin_lock_irqsave(&hp->lock, flags);
+		again = hvsi_load_chunk(hp, tty, &handshake);
+		spin_unlock_irqrestore(&hp->lock, flags);
+
+		if (handshake) {
+			pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
+			schedule_work(&handshake->handshaker);
+		}
+	}
+
+	spin_lock_irqsave(&hp->lock, flags);
+	if (tty && hp->n_throttle && !tty_throttled(tty)) {
+		/* we weren't hung up and we weren't throttled, so we can
+		 * deliver the rest now */
+		hvsi_send_overflow(hp);
+		tty_flip_buffer_push(&hp->port);
+	}
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+	tty_kref_put(tty);
+
+	return IRQ_HANDLED;
+}
+
+/* for boot console, before the irq handler is running */
+static int __init poll_for_state(struct hvsi_struct *hp, int state)
+{
+	unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
+
+	for (;;) {
+		hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */
+
+		if (hp->state == state)
+			return 0;
+
+		mdelay(5);
+		if (time_after(jiffies, end_jiffies))
+			return -EIO;
+	}
+}
+
+/* wait for irq handler to change our state */
+static int wait_for_state(struct hvsi_struct *hp, int state)
+{
+	int ret = 0;
+
+	if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
+		ret = -EIO;
+
+	return ret;
+}
+
+static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
+{
+	struct hvsi_query packet __ALIGNED__;
+	int wrote;
+
+	packet.hdr.type = VS_QUERY_PACKET_HEADER;
+	packet.hdr.len = sizeof(struct hvsi_query);
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.verb = cpu_to_be16(verb);
+
+	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+	wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+	if (wrote != packet.hdr.len) {
+		printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
+			wrote);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int hvsi_get_mctrl(struct hvsi_struct *hp)
+{
+	int ret;
+
+	set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
+	hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
+
+	ret = hvsi_wait(hp, HVSI_OPEN);
+	if (ret < 0) {
+		printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
+		set_state(hp, HVSI_OPEN);
+		return ret;
+	}
+
+	pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl);
+
+	return 0;
+}
+
+/* note that we can only set DTR */
+static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
+{
+	struct hvsi_control packet __ALIGNED__;
+	int wrote;
+
+	packet.hdr.type = VS_CONTROL_PACKET_HEADER;
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.hdr.len = sizeof(struct hvsi_control);
+	packet.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
+	packet.mask = cpu_to_be32(HVSI_TSDTR);
+
+	if (mctrl & TIOCM_DTR)
+		packet.word = cpu_to_be32(HVSI_TSDTR);
+
+	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+	wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+	if (wrote != packet.hdr.len) {
+		printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void hvsi_drain_input(struct hvsi_struct *hp)
+{
+	uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
+	unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
+
+	while (time_before(end_jiffies, jiffies))
+		if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
+			break;
+}
+
+static int hvsi_handshake(struct hvsi_struct *hp)
+{
+	int ret;
+
+	/*
+	 * We could have a CLOSE or other data waiting for us before we even try
+	 * to open; try to throw it all away so we don't get confused. (CLOSE
+	 * is the first message sent up the pipe when the FSP comes online. We
+	 * need to distinguish between "it came up a while ago and we're the first
+	 * user" and "it was just reset before it saw our handshake packet".)
+	 */
+	hvsi_drain_input(hp);
+
+	set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
+	ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
+	if (ret < 0) {
+		printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
+		return ret;
+	}
+
+	ret = hvsi_wait(hp, HVSI_OPEN);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void hvsi_handshaker(struct work_struct *work)
+{
+	struct hvsi_struct *hp =
+		container_of(work, struct hvsi_struct, handshaker);
+
+	if (hvsi_handshake(hp) >= 0)
+		return;
+
+	printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
+	if (is_console(hp)) {
+		/*
+		 * ttys will re-attempt the handshake via hvsi_open, but
+		 * the console will not.
+		 */
+		printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
+	}
+}
+
+static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
+{
+	struct hvsi_data packet __ALIGNED__;
+	int ret;
+
+	BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
+
+	packet.hdr.type = VS_DATA_PACKET_HEADER;
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.hdr.len = count + sizeof(struct hvsi_header);
+	memcpy(&packet.data, buf, count);
+
+	ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+	if (ret == packet.hdr.len) {
+		/* return the number of chars written, not the packet length */
+		return count;
+	}
+	return ret; /* return any errors */
+}
+
+static void hvsi_close_protocol(struct hvsi_struct *hp)
+{
+	struct hvsi_control packet __ALIGNED__;
+
+	packet.hdr.type = VS_CONTROL_PACKET_HEADER;
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.hdr.len = 6;
+	packet.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL);
+
+	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+	hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+}
+
+static int hvsi_open(struct tty_struct *tty, struct file *filp)
+{
+	struct hvsi_struct *hp;
+	unsigned long flags;
+	int ret;
+
+	pr_debug("%s\n", __func__);
+
+	hp = &hvsi_ports[tty->index];
+
+	tty->driver_data = hp;
+
+	mb();
+	if (hp->state == HVSI_FSP_DIED)
+		return -EIO;
+
+	tty_port_tty_set(&hp->port, tty);
+	spin_lock_irqsave(&hp->lock, flags);
+	hp->port.count++;
+	atomic_set(&hp->seqno, 0);
+	h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+	if (is_console(hp))
+		return 0; /* this has already been handshaked as the console */
+
+	ret = hvsi_handshake(hp);
+	if (ret < 0) {
+		printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
+		return ret;
+	}
+
+	ret = hvsi_get_mctrl(hp);
+	if (ret < 0) {
+		printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
+		return ret;
+	}
+
+	ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
+	if (ret < 0) {
+		printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
+		return ret;
+	}
+
+	return 0;
+}
+
+/* wait for hvsi_write_worker to empty hp->outbuf */
+static void hvsi_flush_output(struct hvsi_struct *hp)
+{
+	wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
+
+	/* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
+	cancel_delayed_work_sync(&hp->writer);
+	flush_work(&hp->handshaker);
+
+	/*
+	 * it's also possible that our timeout expired and hvsi_write_worker
+	 * didn't manage to push outbuf. poof.
+	 */
+	hp->n_outbuf = 0;
+}
+
+static void hvsi_close(struct tty_struct *tty, struct file *filp)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+	unsigned long flags;
+
+	pr_debug("%s\n", __func__);
+
+	if (tty_hung_up_p(filp))
+		return;
+
+	spin_lock_irqsave(&hp->lock, flags);
+
+	if (--hp->port.count == 0) {
+		tty_port_tty_set(&hp->port, NULL);
+		hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
+
+		/* only close down connection if it is not the console */
+		if (!is_console(hp)) {
+			h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
+			__set_state(hp, HVSI_CLOSED);
+			/*
+			 * any data delivered to the tty layer after this will be
+			 * discarded (except for XON/XOFF)
+			 */
+			tty->closing = 1;
+
+			spin_unlock_irqrestore(&hp->lock, flags);
+
+			/* let any existing irq handlers finish. no more will start. */
+			synchronize_irq(hp->virq);
+
+			/* hvsi_write_worker will re-schedule until outbuf is empty. */
+			hvsi_flush_output(hp);
+
+			/* tell FSP to stop sending data */
+			hvsi_close_protocol(hp);
+
+			/*
+			 * drain anything FSP is still in the middle of sending, and let
+			 * hvsi_handshake drain the rest on the next open.
+			 */
+			hvsi_drain_input(hp);
+
+			spin_lock_irqsave(&hp->lock, flags);
+		}
+	} else if (hp->port.count < 0)
+		printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
+		       hp - hvsi_ports, hp->port.count);
+
+	spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+static void hvsi_hangup(struct tty_struct *tty)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+	unsigned long flags;
+
+	pr_debug("%s\n", __func__);
+
+	tty_port_tty_set(&hp->port, NULL);
+
+	spin_lock_irqsave(&hp->lock, flags);
+	hp->port.count = 0;
+	hp->n_outbuf = 0;
+	spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+/* called with hp->lock held */
+static void hvsi_push(struct hvsi_struct *hp)
+{
+	int n;
+
+	if (hp->n_outbuf <= 0)
+		return;
+
+	n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
+	if (n > 0) {
+		/* success */
+		pr_debug("%s: wrote %i chars\n", __func__, n);
+		hp->n_outbuf = 0;
+	} else if (n == -EIO) {
+		__set_state(hp, HVSI_FSP_DIED);
+		printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
+	}
+}
+
+/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
+static void hvsi_write_worker(struct work_struct *work)
+{
+	struct hvsi_struct *hp =
+		container_of(work, struct hvsi_struct, writer.work);
+	unsigned long flags;
+#ifdef DEBUG
+	static long start_j = 0;
+
+	if (start_j == 0)
+		start_j = jiffies;
+#endif /* DEBUG */
+
+	spin_lock_irqsave(&hp->lock, flags);
+
+	pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
+
+	if (!is_open(hp)) {
+		/*
+		 * We could have a non-open connection if the service processor died
+		 * while we were busily scheduling ourselves. In that case, it could
+		 * be minutes before the service processor comes back, so only try
+		 * again once a second.
+		 */
+		schedule_delayed_work(&hp->writer, HZ);
+		goto out;
+	}
+
+	hvsi_push(hp);
+	if (hp->n_outbuf > 0)
+		schedule_delayed_work(&hp->writer, 10);
+	else {
+#ifdef DEBUG
+		pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
+				jiffies - start_j);
+		start_j = 0;
+#endif /* DEBUG */
+		wake_up_all(&hp->emptyq);
+		tty_port_tty_wakeup(&hp->port);
+	}
+
+out:
+	spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+static unsigned int hvsi_write_room(struct tty_struct *tty)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+
+	return N_OUTBUF - hp->n_outbuf;
+}
+
+static unsigned int hvsi_chars_in_buffer(struct tty_struct *tty)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+
+	return hp->n_outbuf;
+}
+
+static ssize_t hvsi_write(struct tty_struct *tty, const u8 *source,
+			  size_t count)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+	unsigned long flags;
+	size_t total = 0;
+	size_t origcount = count;
+
+	spin_lock_irqsave(&hp->lock, flags);
+
+	pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
+
+	if (!is_open(hp)) {
+		/* we're either closing or not yet open; don't accept data */
+		pr_debug("%s: not open\n", __func__);
+		goto out;
+	}
+
+	/*
+	 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
+	 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
+	 * will see there is no room in outbuf and return.
+	 */
+	while ((count > 0) && (hvsi_write_room(tty) > 0)) {
+		size_t chunksize = min_t(size_t, count, hvsi_write_room(tty));
+
+		BUG_ON(hp->n_outbuf < 0);
+		memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
+		hp->n_outbuf += chunksize;
+
+		total += chunksize;
+		source += chunksize;
+		count -= chunksize;
+		hvsi_push(hp);
+	}
+
+	if (hp->n_outbuf > 0) {
+		/*
+		 * we weren't able to write it all to the hypervisor.
+		 * schedule another push attempt.
+		 */
+		schedule_delayed_work(&hp->writer, 10);
+	}
+
+out:
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+	if (total != origcount)
+		pr_debug("%s: wanted %zu, only wrote %zu\n", __func__,
+			 origcount, total);
+
+	return total;
+}
+
+/*
+ * I have never seen throttle or unthrottle called, so this little throttle
+ * buffering scheme may or may not work.
+ */
+static void hvsi_throttle(struct tty_struct *tty)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+
+	pr_debug("%s\n", __func__);
+
+	h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
+}
+
+static void hvsi_unthrottle(struct tty_struct *tty)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+	unsigned long flags;
+
+	pr_debug("%s\n", __func__);
+
+	spin_lock_irqsave(&hp->lock, flags);
+	if (hp->n_throttle) {
+		hvsi_send_overflow(hp);
+		tty_flip_buffer_push(&hp->port);
+	}
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+
+	h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
+}
+
+static int hvsi_tiocmget(struct tty_struct *tty)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+
+	hvsi_get_mctrl(hp);
+	return hp->mctrl;
+}
+
+static int hvsi_tiocmset(struct tty_struct *tty,
+				unsigned int set, unsigned int clear)
+{
+	struct hvsi_struct *hp = tty->driver_data;
+	unsigned long flags;
+	uint16_t new_mctrl;
+
+	/* we can only alter DTR */
+	clear &= TIOCM_DTR;
+	set &= TIOCM_DTR;
+
+	spin_lock_irqsave(&hp->lock, flags);
+
+	new_mctrl = (hp->mctrl & ~clear) | set;
+
+	if (hp->mctrl != new_mctrl) {
+		hvsi_set_mctrl(hp, new_mctrl);
+		hp->mctrl = new_mctrl;
+	}
+	spin_unlock_irqrestore(&hp->lock, flags);
+
+	return 0;
+}
+
+
+static const struct tty_operations hvsi_ops = {
+	.open = hvsi_open,
+	.close = hvsi_close,
+	.write = hvsi_write,
+	.hangup = hvsi_hangup,
+	.write_room = hvsi_write_room,
+	.chars_in_buffer = hvsi_chars_in_buffer,
+	.throttle = hvsi_throttle,
+	.unthrottle = hvsi_unthrottle,
+	.tiocmget = hvsi_tiocmget,
+	.tiocmset = hvsi_tiocmset,
+};
+
+static int __init hvsi_init(void)
+{
+	struct tty_driver *driver;
+	int i, ret;
+
+	driver = tty_alloc_driver(hvsi_count, TTY_DRIVER_REAL_RAW);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
+
+	driver->driver_name = "hvsi";
+	driver->name = "hvsi";
+	driver->major = HVSI_MAJOR;
+	driver->minor_start = HVSI_MINOR;
+	driver->type = TTY_DRIVER_TYPE_SYSTEM;
+	driver->init_termios = tty_std_termios;
+	driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
+	driver->init_termios.c_ispeed = 9600;
+	driver->init_termios.c_ospeed = 9600;
+	tty_set_operations(driver, &hvsi_ops);
+
+	for (i=0; i < hvsi_count; i++) {
+		struct hvsi_struct *hp = &hvsi_ports[i];
+		int ret = 1;
+
+		tty_port_link_device(&hp->port, driver, i);
+
+		ret = request_irq(hp->virq, hvsi_interrupt, 0, "hvsi", hp);
+		if (ret)
+			printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
+				hp->virq, ret);
+	}
+	hvsi_wait = wait_for_state; /* irqs active now */
+
+	ret = tty_register_driver(driver);
+	if (ret) {
+		pr_err("Couldn't register hvsi console driver\n");
+		goto err_free_irq;
+	}
+
+	hvsi_driver = driver;
+
+	printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
+
+	return 0;
+err_free_irq:
+	hvsi_wait = poll_for_state;
+	for (i = 0; i < hvsi_count; i++) {
+		struct hvsi_struct *hp = &hvsi_ports[i];
+
+		free_irq(hp->virq, hp);
+	}
+	tty_driver_kref_put(driver);
+
+	return ret;
+}
+device_initcall(hvsi_init);
+
+/***** console (not tty) code: *****/
+
+static void hvsi_console_print(struct console *console, const char *buf,
+		unsigned int count)
+{
+	struct hvsi_struct *hp = &hvsi_ports[console->index];
+	char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
+	unsigned int i = 0, n = 0;
+	int ret, donecr = 0;
+
+	mb();
+	if (!is_open(hp))
+		return;
+
+	/*
+	 * ugh, we have to translate LF -> CRLF ourselves, in place.
+	 * copied from hvc_console.c:
+	 */
+	while (count > 0 || i > 0) {
+		if (count > 0 && i < sizeof(c)) {
+			if (buf[n] == '\n' && !donecr) {
+				c[i++] = '\r';
+				donecr = 1;
+			} else {
+				c[i++] = buf[n++];
+				donecr = 0;
+				--count;
+			}
+		} else {
+			ret = hvsi_put_chars(hp, c, i);
+			if (ret < 0)
+				i = 0;
+			i -= ret;
+		}
+	}
+}
+
+static struct tty_driver *hvsi_console_device(struct console *console,
+	int *index)
+{
+	*index = console->index;
+	return hvsi_driver;
+}
+
+static int __init hvsi_console_setup(struct console *console, char *options)
+{
+	struct hvsi_struct *hp;
+	int ret;
+
+	if (console->index < 0 || console->index >= hvsi_count)
+		return -EINVAL;
+	hp = &hvsi_ports[console->index];
+
+	/* give the FSP a chance to change the baud rate when we re-open */
+	hvsi_close_protocol(hp);
+
+	ret = hvsi_handshake(hp);
+	if (ret < 0)
+		return ret;
+
+	ret = hvsi_get_mctrl(hp);
+	if (ret < 0)
+		return ret;
+
+	ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
+	if (ret < 0)
+		return ret;
+
+	hp->flags |= HVSI_CONSOLE;
+
+	return 0;
+}
+
+static struct console hvsi_console = {
+	.name		= "hvsi",
+	.write		= hvsi_console_print,
+	.device		= hvsi_console_device,
+	.setup		= hvsi_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+
+static int __init hvsi_console_init(void)
+{
+	struct device_node *vty;
+
+	hvsi_wait = poll_for_state; /* no irqs yet; must poll */
+
+	/* search device tree for vty nodes */
+	for_each_compatible_node(vty, "serial", "hvterm-protocol") {
+		struct hvsi_struct *hp;
+		const __be32 *vtermno, *irq;
+
+		vtermno = of_get_property(vty, "reg", NULL);
+		irq = of_get_property(vty, "interrupts", NULL);
+		if (!vtermno || !irq)
+			continue;
+
+		if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
+			of_node_put(vty);
+			break;
+		}
+
+		hp = &hvsi_ports[hvsi_count];
+		INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker);
+		INIT_WORK(&hp->handshaker, hvsi_handshaker);
+		init_waitqueue_head(&hp->emptyq);
+		init_waitqueue_head(&hp->stateq);
+		spin_lock_init(&hp->lock);
+		tty_port_init(&hp->port);
+		hp->index = hvsi_count;
+		hp->inbuf_end = hp->inbuf;
+		hp->state = HVSI_CLOSED;
+		hp->vtermno = be32_to_cpup(vtermno);
+		hp->virq = irq_create_mapping(NULL, be32_to_cpup(irq));
+		if (hp->virq == 0) {
+			printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
+			       __func__, be32_to_cpup(irq));
+			tty_port_destroy(&hp->port);
+			continue;
+		}
+
+		hvsi_count++;
+	}
+
+	if (hvsi_count)
+		register_console(&hvsi_console);
+	return 0;
+}
+console_initcall(hvsi_console_init);
diff --git a/drivers/tty/hvc/hvsi_lib.c b/drivers/tty/hvc/hvsi_lib.c
new file mode 100644
index 000000000..09289c815
--- /dev/null
+++ b/drivers/tty/hvc/hvsi_lib.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+#include <asm/hvsi.h>
+
+#include "hvc_console.h"
+
+static int hvsi_send_packet(struct hvsi_priv *pv, struct hvsi_header *packet)
+{
+	packet->seqno = cpu_to_be16(atomic_inc_return(&pv->seqno));
+
+	/* Assumes that always succeeds, works in practice */
+	return pv->put_chars(pv->termno, (char *)packet, packet->len);
+}
+
+static void hvsi_start_handshake(struct hvsi_priv *pv)
+{
+	struct hvsi_query q;
+
+	/* Reset state */
+	pv->established = 0;
+	atomic_set(&pv->seqno, 0);
+
+	pr_devel("HVSI@%x: Handshaking started\n", pv->termno);
+
+	/* Send version query */
+	q.hdr.type = VS_QUERY_PACKET_HEADER;
+	q.hdr.len = sizeof(struct hvsi_query);
+	q.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
+	hvsi_send_packet(pv, &q.hdr);
+}
+
+static int hvsi_send_close(struct hvsi_priv *pv)
+{
+	struct hvsi_control ctrl;
+
+	pv->established = 0;
+
+	ctrl.hdr.type = VS_CONTROL_PACKET_HEADER;
+	ctrl.hdr.len = sizeof(struct hvsi_control);
+	ctrl.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL);
+	return hvsi_send_packet(pv, &ctrl.hdr);
+}
+
+static void hvsi_cd_change(struct hvsi_priv *pv, int cd)
+{
+	if (cd)
+		pv->mctrl |= TIOCM_CD;
+	else {
+		pv->mctrl &= ~TIOCM_CD;
+
+		/* We copy the existing hvsi driver semantics
+		 * here which are to trigger a hangup when
+		 * we get a carrier loss.
+		 * Closing our connection to the server will
+		 * do just that.
+		 */
+		if (!pv->is_console && pv->opened) {
+			pr_devel("HVSI@%x Carrier lost, hanging up !\n",
+				 pv->termno);
+			hvsi_send_close(pv);
+		}
+	}
+}
+
+static void hvsi_got_control(struct hvsi_priv *pv)
+{
+	struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf;
+
+	switch (be16_to_cpu(pkt->verb)) {
+	case VSV_CLOSE_PROTOCOL:
+		/* We restart the handshaking */
+		hvsi_start_handshake(pv);
+		break;
+	case VSV_MODEM_CTL_UPDATE:
+		/* Transition of carrier detect */
+		hvsi_cd_change(pv, be32_to_cpu(pkt->word) & HVSI_TSCD);
+		break;
+	}
+}
+
+static void hvsi_got_query(struct hvsi_priv *pv)
+{
+	struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf;
+	struct hvsi_query_response r;
+
+	/* We only handle version queries */
+	if (be16_to_cpu(pkt->verb) != VSV_SEND_VERSION_NUMBER)
+		return;
+
+	pr_devel("HVSI@%x: Got version query, sending response...\n",
+		 pv->termno);
+
+	/* Send version response */
+	r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
+	r.hdr.len = sizeof(struct hvsi_query_response);
+	r.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
+	r.u.version = HVSI_VERSION;
+	r.query_seqno = pkt->hdr.seqno;
+	hvsi_send_packet(pv, &r.hdr);
+
+	/* Assume protocol is open now */
+	pv->established = 1;
+}
+
+static void hvsi_got_response(struct hvsi_priv *pv)
+{
+	struct hvsi_query_response *r =
+		(struct hvsi_query_response *)pv->inbuf;
+
+	switch(r->verb) {
+	case VSV_SEND_MODEM_CTL_STATUS:
+		hvsi_cd_change(pv, be32_to_cpu(r->u.mctrl_word) & HVSI_TSCD);
+		pv->mctrl_update = 1;
+		break;
+	}
+}
+
+static int hvsi_check_packet(struct hvsi_priv *pv)
+{
+	u8 len, type;
+
+	/* Check header validity. If it's invalid, we ditch
+	 * the whole buffer and hope we eventually resync
+	 */
+	if (pv->inbuf[0] < 0xfc) {
+		pv->inbuf_len = pv->inbuf_pktlen = 0;
+		return 0;
+	}
+	type = pv->inbuf[0];
+	len = pv->inbuf[1];
+
+	/* Packet incomplete ? */
+	if (pv->inbuf_len < len)
+		return 0;
+
+	pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n",
+		 pv->termno, type, len);
+
+	/* We have a packet, yay ! Handle it */
+	switch(type) {
+	case VS_DATA_PACKET_HEADER:
+		pv->inbuf_pktlen = len - 4;
+		pv->inbuf_cur = 4;
+		return 1;
+	case VS_CONTROL_PACKET_HEADER:
+		hvsi_got_control(pv);
+		break;
+	case VS_QUERY_PACKET_HEADER:
+		hvsi_got_query(pv);
+		break;
+	case VS_QUERY_RESPONSE_PACKET_HEADER:
+		hvsi_got_response(pv);
+		break;
+	}
+
+	/* Swallow packet and retry */
+	pv->inbuf_len -= len;
+	memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len);
+	return 1;
+}
+
+static int hvsi_get_packet(struct hvsi_priv *pv)
+{
+	/* If we have room in the buffer, ask HV for more */
+	if (pv->inbuf_len < HVSI_INBUF_SIZE)
+		pv->inbuf_len += pv->get_chars(pv->termno,
+					     &pv->inbuf[pv->inbuf_len],
+					     HVSI_INBUF_SIZE - pv->inbuf_len);
+	/*
+	 * If we have at least 4 bytes in the buffer, check for
+	 * a full packet and retry
+	 */
+	if (pv->inbuf_len >= 4)
+		return hvsi_check_packet(pv);
+	return 0;
+}
+
+int hvsilib_get_chars(struct hvsi_priv *pv, char *buf, int count)
+{
+	unsigned int tries, read = 0;
+
+	if (WARN_ON(!pv))
+		return -ENXIO;
+
+	/* If we aren't open, don't do anything in order to avoid races
+	 * with connection establishment. The hvc core will call this
+	 * before we have returned from notifier_add(), and we need to
+	 * avoid multiple users playing with the receive buffer
+	 */
+	if (!pv->opened)
+		return 0;
+
+	/* We try twice, once with what data we have and once more
+	 * after we try to fetch some more from the hypervisor
+	 */
+	for (tries = 1; count && tries < 2; tries++) {
+		/* Consume existing data packet */
+		if (pv->inbuf_pktlen) {
+			unsigned int l = min(count, (int)pv->inbuf_pktlen);
+			memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l);
+			pv->inbuf_cur += l;
+			pv->inbuf_pktlen -= l;
+			count -= l;
+			read += l;
+		}
+		if (count == 0)
+			break;
+
+		/* Data packet fully consumed, move down remaning data */
+		if (pv->inbuf_cur) {
+			pv->inbuf_len -= pv->inbuf_cur;
+			memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur],
+				pv->inbuf_len);
+			pv->inbuf_cur = 0;
+		}
+
+		/* Try to get another packet */
+		if (hvsi_get_packet(pv))
+			tries--;
+	}
+	if (!pv->established) {
+		pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno);
+		return -EPIPE;
+	}
+	return read;
+}
+
+int hvsilib_put_chars(struct hvsi_priv *pv, const char *buf, int count)
+{
+	struct hvsi_data dp;
+	int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA);
+
+	if (WARN_ON(!pv))
+		return -ENODEV;
+
+	dp.hdr.type = VS_DATA_PACKET_HEADER;
+	dp.hdr.len = adjcount + sizeof(struct hvsi_header);
+	memcpy(dp.data, buf, adjcount);
+	rc = hvsi_send_packet(pv, &dp.hdr);
+	if (rc <= 0)
+		return rc;
+	return adjcount;
+}
+
+static void maybe_msleep(unsigned long ms)
+{
+	/* During early boot, IRQs are disabled, use mdelay */
+	if (irqs_disabled())
+		mdelay(ms);
+	else
+		msleep(ms);
+}
+
+int hvsilib_read_mctrl(struct hvsi_priv *pv)
+{
+	struct hvsi_query q;
+	int rc, timeout;
+
+	pr_devel("HVSI@%x: Querying modem control status...\n",
+		 pv->termno);
+
+	pv->mctrl_update = 0;
+	q.hdr.type = VS_QUERY_PACKET_HEADER;
+	q.hdr.len = sizeof(struct hvsi_query);
+	q.verb = cpu_to_be16(VSV_SEND_MODEM_CTL_STATUS);
+	rc = hvsi_send_packet(pv, &q.hdr);
+	if (rc <= 0) {
+		pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc);
+		return rc;
+	}
+
+	/* Try for up to 200ms */
+	for (timeout = 0; timeout < 20; timeout++) {
+		if (!pv->established)
+			return -ENXIO;
+		if (pv->mctrl_update)
+			return 0;
+		if (!hvsi_get_packet(pv))
+			maybe_msleep(10);
+	}
+	return -EIO;
+}
+
+int hvsilib_write_mctrl(struct hvsi_priv *pv, int dtr)
+{
+	struct hvsi_control ctrl;
+	unsigned short mctrl;
+
+	mctrl = pv->mctrl;
+	if (dtr)
+		mctrl |= TIOCM_DTR;
+	else
+		mctrl &= ~TIOCM_DTR;
+	if (mctrl == pv->mctrl)
+		return 0;
+	pv->mctrl = mctrl;
+
+	pr_devel("HVSI@%x: %s DTR...\n", pv->termno,
+		 dtr ? "Setting" : "Clearing");
+
+	ctrl.hdr.type = VS_CONTROL_PACKET_HEADER,
+	ctrl.hdr.len = sizeof(struct hvsi_control);
+	ctrl.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
+	ctrl.mask = cpu_to_be32(HVSI_TSDTR);
+	ctrl.word = cpu_to_be32(dtr ? HVSI_TSDTR : 0);
+	return hvsi_send_packet(pv, &ctrl.hdr);
+}
+
+void hvsilib_establish(struct hvsi_priv *pv)
+{
+	int timeout;
+
+	pr_devel("HVSI@%x: Establishing...\n", pv->termno);
+
+	/* Try for up to 200ms, there can be a packet to
+	 * start the process waiting for us...
+	 */
+	for (timeout = 0; timeout < 20; timeout++) {
+		if (pv->established)
+			goto established;
+		if (!hvsi_get_packet(pv))
+			maybe_msleep(10);
+	}
+
+	/* Failed, send a close connection packet just
+	 * in case
+	 */
+	pr_devel("HVSI@%x:   ... sending close\n", pv->termno);
+
+	hvsi_send_close(pv);
+
+	/* Then restart handshake */
+
+	pr_devel("HVSI@%x:   ... restarting handshake\n", pv->termno);
+
+	hvsi_start_handshake(pv);
+
+	pr_devel("HVSI@%x:   ... waiting handshake\n", pv->termno);
+
+	/* Try for up to 400ms */
+	for (timeout = 0; timeout < 40; timeout++) {
+		if (pv->established)
+			goto established;
+		if (!hvsi_get_packet(pv))
+			maybe_msleep(10);
+	}
+
+	if (!pv->established) {
+		pr_devel("HVSI@%x: Timeout handshaking, giving up !\n",
+			 pv->termno);
+		return;
+	}
+ established:
+	/* Query modem control lines */
+
+	pr_devel("HVSI@%x:   ... established, reading mctrl\n", pv->termno);
+
+	hvsilib_read_mctrl(pv);
+
+	/* Set our own DTR */
+
+	pr_devel("HVSI@%x:   ... setting mctrl\n", pv->termno);
+
+	hvsilib_write_mctrl(pv, 1);
+
+	/* Set the opened flag so reads are allowed */
+	wmb();
+	pv->opened = 1;
+}
+
+int hvsilib_open(struct hvsi_priv *pv, struct hvc_struct *hp)
+{
+	pr_devel("HVSI@%x: open !\n", pv->termno);
+
+	/* Keep track of the tty data structure */
+	pv->tty = tty_port_tty_get(&hp->port);
+
+	hvsilib_establish(pv);
+
+	return 0;
+}
+
+void hvsilib_close(struct hvsi_priv *pv, struct hvc_struct *hp)
+{
+	unsigned long flags;
+
+	pr_devel("HVSI@%x: close !\n", pv->termno);
+
+	if (!pv->is_console) {
+		pr_devel("HVSI@%x: Not a console, tearing down\n",
+			 pv->termno);
+
+		/* Clear opened, synchronize with khvcd */
+		spin_lock_irqsave(&hp->lock, flags);
+		pv->opened = 0;
+		spin_unlock_irqrestore(&hp->lock, flags);
+
+		/* Clear our own DTR */
+		if (!pv->tty || (pv->tty->termios.c_cflag & HUPCL))
+			hvsilib_write_mctrl(pv, 0);
+
+		/* Tear down the connection */
+		hvsi_send_close(pv);
+	}
+
+	tty_kref_put(pv->tty);
+	pv->tty = NULL;
+}
+
+void hvsilib_init(struct hvsi_priv *pv,
+		  int (*get_chars)(uint32_t termno, char *buf, int count),
+		  int (*put_chars)(uint32_t termno, const char *buf,
+				   int count),
+		  int termno, int is_console)
+{
+	memset(pv, 0, sizeof(*pv));
+	pv->get_chars = get_chars;
+	pv->put_chars = put_chars;
+	pv->termno = termno;
+	pv->is_console = is_console;
+}
diff --git a/drivers/tty/ipwireless/Makefile b/drivers/tty/ipwireless/Makefile
new file mode 100644
index 000000000..a665d021e
--- /dev/null
+++ b/drivers/tty/ipwireless/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the IPWireless driver
+#
+
+obj-$(CONFIG_IPWIRELESS) += ipwireless.o
+
+ipwireless-y := hardware.o main.o network.o tty.o
+
diff --git a/drivers/tty/ipwireless/hardware.c b/drivers/tty/ipwireless/hardware.c
new file mode 100644
index 000000000..001ec318a
--- /dev/null
+++ b/drivers/tty/ipwireless/hardware.c
@@ -0,0 +1,1770 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "hardware.h"
+#include "setup_protocol.h"
+#include "network.h"
+#include "main.h"
+
+static void ipw_send_setup_packet(struct ipw_hardware *hw);
+static void handle_received_SETUP_packet(struct ipw_hardware *ipw,
+					 unsigned int address,
+					 const unsigned char *data, int len,
+					 int is_last);
+static void ipwireless_setup_timer(struct timer_list *t);
+static void handle_received_CTRL_packet(struct ipw_hardware *hw,
+		unsigned int channel_idx, const unsigned char *data, int len);
+
+/*#define TIMING_DIAGNOSTICS*/
+
+#ifdef TIMING_DIAGNOSTICS
+
+static struct timing_stats {
+	unsigned long last_report_time;
+	unsigned long read_time;
+	unsigned long write_time;
+	unsigned long read_bytes;
+	unsigned long write_bytes;
+	unsigned long start_time;
+};
+
+static void start_timing(void)
+{
+	timing_stats.start_time = jiffies;
+}
+
+static void end_read_timing(unsigned length)
+{
+	timing_stats.read_time += (jiffies - start_time);
+	timing_stats.read_bytes += length + 2;
+	report_timing();
+}
+
+static void end_write_timing(unsigned length)
+{
+	timing_stats.write_time += (jiffies - start_time);
+	timing_stats.write_bytes += length + 2;
+	report_timing();
+}
+
+static void report_timing(void)
+{
+	unsigned long since = jiffies - timing_stats.last_report_time;
+
+	/* If it's been more than one second... */
+	if (since >= HZ) {
+		int first = (timing_stats.last_report_time == 0);
+
+		timing_stats.last_report_time = jiffies;
+		if (!first)
+			printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+			       ": %u us elapsed - read %lu bytes in %u us, wrote %lu bytes in %u us\n",
+			       jiffies_to_usecs(since),
+			       timing_stats.read_bytes,
+			       jiffies_to_usecs(timing_stats.read_time),
+			       timing_stats.write_bytes,
+			       jiffies_to_usecs(timing_stats.write_time));
+
+		timing_stats.read_time = 0;
+		timing_stats.write_time = 0;
+		timing_stats.read_bytes = 0;
+		timing_stats.write_bytes = 0;
+	}
+}
+#else
+static void start_timing(void) { }
+static void end_read_timing(unsigned length) { }
+static void end_write_timing(unsigned length) { }
+#endif
+
+/* Imported IPW definitions */
+
+#define LL_MTU_V1 318
+#define LL_MTU_V2 250
+#define LL_MTU_MAX (LL_MTU_V1 > LL_MTU_V2 ? LL_MTU_V1 : LL_MTU_V2)
+
+#define PRIO_DATA  2
+#define PRIO_CTRL  1
+#define PRIO_SETUP 0
+
+/* Addresses */
+#define ADDR_SETUP_PROT 0
+
+/* Protocol ids */
+enum {
+	/* Identifier for the Com Data protocol */
+	TL_PROTOCOLID_COM_DATA = 0,
+
+	/* Identifier for the Com Control protocol */
+	TL_PROTOCOLID_COM_CTRL = 1,
+
+	/* Identifier for the Setup protocol */
+	TL_PROTOCOLID_SETUP = 2
+};
+
+/* Number of bytes in NL packet header (cannot do
+ * sizeof(nl_packet_header) since it's a bitfield) */
+#define NL_FIRST_PACKET_HEADER_SIZE        3
+
+/* Number of bytes in NL packet header (cannot do
+ * sizeof(nl_packet_header) since it's a bitfield) */
+#define NL_FOLLOWING_PACKET_HEADER_SIZE    1
+
+struct nl_first_packet_header {
+	unsigned char protocol:3;
+	unsigned char address:3;
+	unsigned char packet_rank:2;
+	unsigned char length_lsb;
+	unsigned char length_msb;
+};
+
+struct nl_packet_header {
+	unsigned char protocol:3;
+	unsigned char address:3;
+	unsigned char packet_rank:2;
+};
+
+/* Value of 'packet_rank' above */
+#define NL_INTERMEDIATE_PACKET    0x0
+#define NL_LAST_PACKET            0x1
+#define NL_FIRST_PACKET           0x2
+
+union nl_packet {
+	/* Network packet header of the first packet (a special case) */
+	struct nl_first_packet_header hdr_first;
+	/* Network packet header of the following packets (if any) */
+	struct nl_packet_header hdr;
+	/* Complete network packet (header + data) */
+	unsigned char rawpkt[LL_MTU_MAX];
+} __attribute__ ((__packed__));
+
+#define HW_VERSION_UNKNOWN -1
+#define HW_VERSION_1 1
+#define HW_VERSION_2 2
+
+/* IPW I/O ports */
+#define IOIER 0x00		/* Interrupt Enable Register */
+#define IOIR  0x02		/* Interrupt Source/ACK register */
+#define IODCR 0x04		/* Data Control Register */
+#define IODRR 0x06		/* Data Read Register */
+#define IODWR 0x08		/* Data Write Register */
+#define IOESR 0x0A		/* Embedded Driver Status Register */
+#define IORXR 0x0C		/* Rx Fifo Register (Host to Embedded) */
+#define IOTXR 0x0E		/* Tx Fifo Register (Embedded to Host) */
+
+/* I/O ports and bit definitions for version 1 of the hardware */
+
+/* IER bits*/
+#define IER_RXENABLED   0x1
+#define IER_TXENABLED   0x2
+
+/* ISR bits */
+#define IR_RXINTR       0x1
+#define IR_TXINTR       0x2
+
+/* DCR bits */
+#define DCR_RXDONE      0x1
+#define DCR_TXDONE      0x2
+#define DCR_RXRESET     0x4
+#define DCR_TXRESET     0x8
+
+/* I/O ports and bit definitions for version 2 of the hardware */
+
+struct MEMCCR {
+	unsigned short reg_config_option;	/* PCCOR: Configuration Option Register */
+	unsigned short reg_config_and_status;	/* PCCSR: Configuration and Status Register */
+	unsigned short reg_pin_replacement;	/* PCPRR: Pin Replacemant Register */
+	unsigned short reg_socket_and_copy;	/* PCSCR: Socket and Copy Register */
+	unsigned short reg_ext_status;		/* PCESR: Extendend Status Register */
+	unsigned short reg_io_base;		/* PCIOB: I/O Base Register */
+};
+
+struct MEMINFREG {
+	unsigned short memreg_tx_old;	/* TX Register (R/W) */
+	unsigned short pad1;
+	unsigned short memreg_rx_done;	/* RXDone Register (R/W) */
+	unsigned short pad2;
+	unsigned short memreg_rx;	/* RX Register (R/W) */
+	unsigned short pad3;
+	unsigned short memreg_pc_interrupt_ack;	/* PC intr Ack Register (W) */
+	unsigned short pad4;
+	unsigned long memreg_card_present;/* Mask for Host to check (R) for
+					   * CARD_PRESENT_VALUE */
+	unsigned short memreg_tx_new;	/* TX2 (new) Register (R/W) */
+};
+
+#define CARD_PRESENT_VALUE (0xBEEFCAFEUL)
+
+#define MEMTX_TX                       0x0001
+#define MEMRX_RX                       0x0001
+#define MEMRX_RX_DONE                  0x0001
+#define MEMRX_PCINTACKK                0x0001
+
+#define NL_NUM_OF_PRIORITIES       3
+#define NL_NUM_OF_PROTOCOLS        3
+#define NL_NUM_OF_ADDRESSES        NO_OF_IPW_CHANNELS
+
+struct ipw_hardware {
+	unsigned int base_port;
+	short hw_version;
+	unsigned short ll_mtu;
+	spinlock_t lock;
+
+	int initializing;
+	int init_loops;
+	struct timer_list setup_timer;
+
+	/* Flag if hw is ready to send next packet */
+	int tx_ready;
+	/* Count of pending packets to be sent */
+	int tx_queued;
+	struct list_head tx_queue[NL_NUM_OF_PRIORITIES];
+
+	int rx_bytes_queued;
+	struct list_head rx_queue;
+	/* Pool of rx_packet structures that are not currently used. */
+	struct list_head rx_pool;
+	int rx_pool_size;
+	/* True if reception of data is blocked while userspace processes it. */
+	int blocking_rx;
+	/* True if there is RX data ready on the hardware. */
+	int rx_ready;
+	unsigned short last_memtx_serial;
+	/*
+	 * Newer versions of the V2 card firmware send serial numbers in the
+	 * MemTX register. 'serial_number_detected' is set true when we detect
+	 * a non-zero serial number (indicating the new firmware).  Thereafter,
+	 * the driver can safely ignore the Timer Recovery re-sends to avoid
+	 * out-of-sync problems.
+	 */
+	int serial_number_detected;
+	struct work_struct work_rx;
+
+	/* True if we are to send the set-up data to the hardware. */
+	int to_setup;
+
+	/* Card has been removed */
+	int removed;
+	/* Saved irq value when we disable the interrupt. */
+	int irq;
+	/* True if this driver is shutting down. */
+	int shutting_down;
+	/* Modem control lines */
+	unsigned int control_lines[NL_NUM_OF_ADDRESSES];
+	struct ipw_rx_packet *packet_assembler[NL_NUM_OF_ADDRESSES];
+
+	struct tasklet_struct tasklet;
+
+	/* The handle for the network layer, for the sending of events to it. */
+	struct ipw_network *network;
+	struct MEMINFREG __iomem *memory_info_regs;
+	struct MEMCCR __iomem *memregs_CCR;
+	void (*reboot_callback) (void *data);
+	void *reboot_callback_data;
+
+	unsigned short __iomem *memreg_tx;
+};
+
+/*
+ * Packet info structure for tx packets.
+ * Note: not all the fields defined here are required for all protocols
+ */
+struct ipw_tx_packet {
+	struct list_head queue;
+	/* channel idx + 1 */
+	unsigned char dest_addr;
+	/* SETUP, CTRL or DATA */
+	unsigned char protocol;
+	/* Length of data block, which starts at the end of this structure */
+	unsigned short length;
+	/* Sending state */
+	/* Offset of where we've sent up to so far */
+	unsigned long offset;
+	/* Count of packet fragments, starting at 0 */
+	int fragment_count;
+
+	/* Called after packet is sent and before is freed */
+	void (*packet_callback) (void *cb_data, unsigned int packet_length);
+	void *callback_data;
+};
+
+/* Signals from DTE */
+#define COMCTRL_RTS	0
+#define COMCTRL_DTR	1
+
+/* Signals from DCE */
+#define COMCTRL_CTS	2
+#define COMCTRL_DCD	3
+#define COMCTRL_DSR	4
+#define COMCTRL_RI	5
+
+struct ipw_control_packet_body {
+	/* DTE signal or DCE signal */
+	unsigned char sig_no;
+	/* 0: set signal, 1: clear signal */
+	unsigned char value;
+} __attribute__ ((__packed__));
+
+struct ipw_control_packet {
+	struct ipw_tx_packet header;
+	struct ipw_control_packet_body body;
+};
+
+struct ipw_rx_packet {
+	struct list_head queue;
+	unsigned int capacity;
+	unsigned int length;
+	unsigned int protocol;
+	unsigned int channel_idx;
+};
+
+static char *data_type(const unsigned char *buf, unsigned length)
+{
+	struct nl_packet_header *hdr = (struct nl_packet_header *) buf;
+
+	if (length == 0)
+		return "     ";
+
+	if (hdr->packet_rank & NL_FIRST_PACKET) {
+		switch (hdr->protocol) {
+		case TL_PROTOCOLID_COM_DATA:	return "DATA ";
+		case TL_PROTOCOLID_COM_CTRL:	return "CTRL ";
+		case TL_PROTOCOLID_SETUP:	return "SETUP";
+		default: return "???? ";
+		}
+	} else
+		return "     ";
+}
+
+#define DUMP_MAX_BYTES 64
+
+static void dump_data_bytes(const char *type, const unsigned char *data,
+			    unsigned length)
+{
+	char prefix[56];
+
+	sprintf(prefix, IPWIRELESS_PCCARD_NAME ": %s %s ",
+			type, data_type(data, length));
+	print_hex_dump_bytes(prefix, 0, (void *)data,
+			length < DUMP_MAX_BYTES ? length : DUMP_MAX_BYTES);
+}
+
+static void swap_packet_bitfield_to_le(unsigned char *data)
+{
+#ifdef __BIG_ENDIAN_BITFIELD
+	unsigned char tmp = *data, ret = 0;
+
+	/*
+	 * transform bits from aa.bbb.ccc to ccc.bbb.aa
+	 */
+	ret |= (tmp & 0xc0) >> 6;
+	ret |= (tmp & 0x38) >> 1;
+	ret |= (tmp & 0x07) << 5;
+	*data = ret & 0xff;
+#endif
+}
+
+static void swap_packet_bitfield_from_le(unsigned char *data)
+{
+#ifdef __BIG_ENDIAN_BITFIELD
+	unsigned char tmp = *data, ret = 0;
+
+	/*
+	 * transform bits from ccc.bbb.aa to aa.bbb.ccc
+	 */
+	ret |= (tmp & 0xe0) >> 5;
+	ret |= (tmp & 0x1c) << 1;
+	ret |= (tmp & 0x03) << 6;
+	*data = ret & 0xff;
+#endif
+}
+
+static void do_send_fragment(struct ipw_hardware *hw, unsigned char *data,
+			    unsigned length)
+{
+	unsigned i;
+	unsigned long flags;
+
+	start_timing();
+	BUG_ON(length > hw->ll_mtu);
+
+	if (ipwireless_debug)
+		dump_data_bytes("send", data, length);
+
+	spin_lock_irqsave(&hw->lock, flags);
+
+	hw->tx_ready = 0;
+	swap_packet_bitfield_to_le(data);
+
+	if (hw->hw_version == HW_VERSION_1) {
+		outw((unsigned short) length, hw->base_port + IODWR);
+
+		for (i = 0; i < length; i += 2) {
+			unsigned short d = data[i];
+			__le16 raw_data;
+
+			if (i + 1 < length)
+				d |= data[i + 1] << 8;
+			raw_data = cpu_to_le16(d);
+			outw(raw_data, hw->base_port + IODWR);
+		}
+
+		outw(DCR_TXDONE, hw->base_port + IODCR);
+	} else if (hw->hw_version == HW_VERSION_2) {
+		outw((unsigned short) length, hw->base_port);
+
+		for (i = 0; i < length; i += 2) {
+			unsigned short d = data[i];
+			__le16 raw_data;
+
+			if (i + 1 < length)
+				d |= data[i + 1] << 8;
+			raw_data = cpu_to_le16(d);
+			outw(raw_data, hw->base_port);
+		}
+		while ((i & 3) != 2) {
+			outw((unsigned short) 0xDEAD, hw->base_port);
+			i += 2;
+		}
+		writew(MEMRX_RX, &hw->memory_info_regs->memreg_rx);
+	}
+
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+	end_write_timing(length);
+}
+
+static void do_send_packet(struct ipw_hardware *hw, struct ipw_tx_packet *packet)
+{
+	unsigned short fragment_data_len;
+	unsigned short data_left = packet->length - packet->offset;
+	unsigned short header_size;
+	union nl_packet pkt;
+
+	header_size =
+	    (packet->fragment_count == 0)
+	    ? NL_FIRST_PACKET_HEADER_SIZE
+	    : NL_FOLLOWING_PACKET_HEADER_SIZE;
+	fragment_data_len = hw->ll_mtu - header_size;
+	if (data_left < fragment_data_len)
+		fragment_data_len = data_left;
+
+	/*
+	 * hdr_first is now in machine bitfield order, which will be swapped
+	 * to le just before it goes to hw
+	 */
+	pkt.hdr_first.protocol = packet->protocol;
+	pkt.hdr_first.address = packet->dest_addr;
+	pkt.hdr_first.packet_rank = 0;
+
+	/* First packet? */
+	if (packet->fragment_count == 0) {
+		pkt.hdr_first.packet_rank |= NL_FIRST_PACKET;
+		pkt.hdr_first.length_lsb = (unsigned char) packet->length;
+		pkt.hdr_first.length_msb =
+			(unsigned char) (packet->length >> 8);
+	}
+
+	memcpy(pkt.rawpkt + header_size,
+	       ((unsigned char *) packet) + sizeof(struct ipw_tx_packet) +
+	       packet->offset, fragment_data_len);
+	packet->offset += fragment_data_len;
+	packet->fragment_count++;
+
+	/* Last packet? (May also be first packet.) */
+	if (packet->offset == packet->length)
+		pkt.hdr_first.packet_rank |= NL_LAST_PACKET;
+	do_send_fragment(hw, pkt.rawpkt, header_size + fragment_data_len);
+
+	/* If this packet has unsent data, then re-queue it. */
+	if (packet->offset < packet->length) {
+		/*
+		 * Re-queue it at the head of the highest priority queue so
+		 * it goes before all other packets
+		 */
+		unsigned long flags;
+
+		spin_lock_irqsave(&hw->lock, flags);
+		list_add(&packet->queue, &hw->tx_queue[0]);
+		hw->tx_queued++;
+		spin_unlock_irqrestore(&hw->lock, flags);
+	} else {
+		if (packet->packet_callback)
+			packet->packet_callback(packet->callback_data,
+					packet->length);
+		kfree(packet);
+	}
+}
+
+static void ipw_setup_hardware(struct ipw_hardware *hw)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	if (hw->hw_version == HW_VERSION_1) {
+		/* Reset RX FIFO */
+		outw(DCR_RXRESET, hw->base_port + IODCR);
+		/* SB: Reset TX FIFO */
+		outw(DCR_TXRESET, hw->base_port + IODCR);
+
+		/* Enable TX and RX interrupts. */
+		outw(IER_TXENABLED | IER_RXENABLED, hw->base_port + IOIER);
+	} else {
+		/*
+		 * Set INTRACK bit (bit 0), which means we must explicitly
+		 * acknowledge interrupts by clearing bit 2 of reg_config_and_status.
+		 */
+		unsigned short csr = readw(&hw->memregs_CCR->reg_config_and_status);
+
+		csr |= 1;
+		writew(csr, &hw->memregs_CCR->reg_config_and_status);
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+}
+
+/*
+ * If 'packet' is NULL, then this function allocates a new packet, setting its
+ * length to 0 and ensuring it has the specified minimum amount of free space.
+ *
+ * If 'packet' is not NULL, then this function enlarges it if it doesn't
+ * have the specified minimum amount of free space.
+ *
+ */
+static struct ipw_rx_packet *pool_allocate(struct ipw_hardware *hw,
+					   struct ipw_rx_packet *packet,
+					   int minimum_free_space)
+{
+
+	if (!packet) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&hw->lock, flags);
+		if (!list_empty(&hw->rx_pool)) {
+			packet = list_first_entry(&hw->rx_pool,
+					struct ipw_rx_packet, queue);
+			hw->rx_pool_size--;
+			spin_unlock_irqrestore(&hw->lock, flags);
+			list_del(&packet->queue);
+		} else {
+			const int min_capacity =
+				ipwireless_ppp_mru(hw->network) + 2;
+			int new_capacity;
+
+			spin_unlock_irqrestore(&hw->lock, flags);
+			new_capacity =
+				(minimum_free_space > min_capacity
+				 ? minimum_free_space
+				 : min_capacity);
+			packet = kmalloc(sizeof(struct ipw_rx_packet)
+					+ new_capacity, GFP_ATOMIC);
+			if (!packet)
+				return NULL;
+			packet->capacity = new_capacity;
+		}
+		packet->length = 0;
+	}
+
+	if (packet->length + minimum_free_space > packet->capacity) {
+		struct ipw_rx_packet *old_packet = packet;
+
+		packet = kmalloc(sizeof(struct ipw_rx_packet) +
+				old_packet->length + minimum_free_space,
+				GFP_ATOMIC);
+		if (!packet) {
+			kfree(old_packet);
+			return NULL;
+		}
+		memcpy(packet, old_packet,
+				sizeof(struct ipw_rx_packet)
+					+ old_packet->length);
+		packet->capacity = old_packet->length + minimum_free_space;
+		kfree(old_packet);
+	}
+
+	return packet;
+}
+
+static void pool_free(struct ipw_hardware *hw, struct ipw_rx_packet *packet)
+{
+	if (hw->rx_pool_size > 6)
+		kfree(packet);
+	else {
+		hw->rx_pool_size++;
+		list_add(&packet->queue, &hw->rx_pool);
+	}
+}
+
+static void queue_received_packet(struct ipw_hardware *hw,
+				  unsigned int protocol,
+				  unsigned int address,
+				  const unsigned char *data, int length,
+				  int is_last)
+{
+	unsigned int channel_idx = address - 1;
+	struct ipw_rx_packet *packet = NULL;
+	unsigned long flags;
+
+	/* Discard packet if channel index is out of range. */
+	if (channel_idx >= NL_NUM_OF_ADDRESSES) {
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		       ": data packet has bad address %u\n", address);
+		return;
+	}
+
+	/*
+	 * ->packet_assembler is safe to touch unlocked, this is the only place
+	 */
+	if (protocol == TL_PROTOCOLID_COM_DATA) {
+		struct ipw_rx_packet **assem =
+			&hw->packet_assembler[channel_idx];
+
+		/*
+		 * Create a new packet, or assembler already contains one
+		 * enlarge it by 'length' bytes.
+		 */
+		(*assem) = pool_allocate(hw, *assem, length);
+		if (!(*assem)) {
+			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+				": no memory for incoming data packet, dropped!\n");
+			return;
+		}
+		(*assem)->protocol = protocol;
+		(*assem)->channel_idx = channel_idx;
+
+		/* Append this packet data onto existing data. */
+		memcpy((unsigned char *)(*assem) +
+			       sizeof(struct ipw_rx_packet)
+				+ (*assem)->length, data, length);
+		(*assem)->length += length;
+		if (is_last) {
+			packet = *assem;
+			*assem = NULL;
+			/* Count queued DATA bytes only */
+			spin_lock_irqsave(&hw->lock, flags);
+			hw->rx_bytes_queued += packet->length;
+			spin_unlock_irqrestore(&hw->lock, flags);
+		}
+	} else {
+		/* If it's a CTRL packet, don't assemble, just queue it. */
+		packet = pool_allocate(hw, NULL, length);
+		if (!packet) {
+			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+				": no memory for incoming ctrl packet, dropped!\n");
+			return;
+		}
+		packet->protocol = protocol;
+		packet->channel_idx = channel_idx;
+		memcpy((unsigned char *)packet + sizeof(struct ipw_rx_packet),
+				data, length);
+		packet->length = length;
+	}
+
+	/*
+	 * If this is the last packet, then send the assembled packet on to the
+	 * network layer.
+	 */
+	if (packet) {
+		spin_lock_irqsave(&hw->lock, flags);
+		list_add_tail(&packet->queue, &hw->rx_queue);
+		/* Block reception of incoming packets if queue is full. */
+		hw->blocking_rx =
+			(hw->rx_bytes_queued >= IPWIRELESS_RX_QUEUE_SIZE);
+
+		spin_unlock_irqrestore(&hw->lock, flags);
+		schedule_work(&hw->work_rx);
+	}
+}
+
+/*
+ * Workqueue callback
+ */
+static void ipw_receive_data_work(struct work_struct *work_rx)
+{
+	struct ipw_hardware *hw =
+	    container_of(work_rx, struct ipw_hardware, work_rx);
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	while (!list_empty(&hw->rx_queue)) {
+		struct ipw_rx_packet *packet =
+			list_first_entry(&hw->rx_queue,
+					struct ipw_rx_packet, queue);
+
+		if (hw->shutting_down)
+			break;
+		list_del(&packet->queue);
+
+		/*
+		 * Note: ipwireless_network_packet_received must be called in a
+		 * process context (i.e. via schedule_work) because the tty
+		 * output code can sleep in the tty_flip_buffer_push call.
+		 */
+		if (packet->protocol == TL_PROTOCOLID_COM_DATA) {
+			if (hw->network != NULL) {
+				/* If the network hasn't been disconnected. */
+				spin_unlock_irqrestore(&hw->lock, flags);
+				/*
+				 * This must run unlocked due to tty processing
+				 * and mutex locking
+				 */
+				ipwireless_network_packet_received(
+						hw->network,
+						packet->channel_idx,
+						(unsigned char *)packet
+						+ sizeof(struct ipw_rx_packet),
+						packet->length);
+				spin_lock_irqsave(&hw->lock, flags);
+			}
+			/* Count queued DATA bytes only */
+			hw->rx_bytes_queued -= packet->length;
+		} else {
+			/*
+			 * This is safe to be called locked, callchain does
+			 * not block
+			 */
+			handle_received_CTRL_packet(hw, packet->channel_idx,
+					(unsigned char *)packet
+					+ sizeof(struct ipw_rx_packet),
+					packet->length);
+		}
+		pool_free(hw, packet);
+		/*
+		 * Unblock reception of incoming packets if queue is no longer
+		 * full.
+		 */
+		hw->blocking_rx =
+			hw->rx_bytes_queued >= IPWIRELESS_RX_QUEUE_SIZE;
+		if (hw->shutting_down)
+			break;
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+}
+
+static void handle_received_CTRL_packet(struct ipw_hardware *hw,
+					unsigned int channel_idx,
+					const unsigned char *data, int len)
+{
+	const struct ipw_control_packet_body *body =
+		(const struct ipw_control_packet_body *) data;
+	unsigned int changed_mask;
+
+	if (len != sizeof(struct ipw_control_packet_body)) {
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		       ": control packet was %d bytes - wrong size!\n",
+		       len);
+		return;
+	}
+
+	switch (body->sig_no) {
+	case COMCTRL_CTS:
+		changed_mask = IPW_CONTROL_LINE_CTS;
+		break;
+	case COMCTRL_DCD:
+		changed_mask = IPW_CONTROL_LINE_DCD;
+		break;
+	case COMCTRL_DSR:
+		changed_mask = IPW_CONTROL_LINE_DSR;
+		break;
+	case COMCTRL_RI:
+		changed_mask = IPW_CONTROL_LINE_RI;
+		break;
+	default:
+		changed_mask = 0;
+	}
+
+	if (changed_mask != 0) {
+		if (body->value)
+			hw->control_lines[channel_idx] |= changed_mask;
+		else
+			hw->control_lines[channel_idx] &= ~changed_mask;
+		if (hw->network)
+			ipwireless_network_notify_control_line_change(
+					hw->network,
+					channel_idx,
+					hw->control_lines[channel_idx],
+					changed_mask);
+	}
+}
+
+static void handle_received_packet(struct ipw_hardware *hw,
+				   const union nl_packet *packet,
+				   unsigned short len)
+{
+	unsigned int protocol = packet->hdr.protocol;
+	unsigned int address = packet->hdr.address;
+	unsigned int header_length;
+	const unsigned char *data;
+	unsigned int data_len;
+	int is_last = packet->hdr.packet_rank & NL_LAST_PACKET;
+
+	if (packet->hdr.packet_rank & NL_FIRST_PACKET)
+		header_length = NL_FIRST_PACKET_HEADER_SIZE;
+	else
+		header_length = NL_FOLLOWING_PACKET_HEADER_SIZE;
+
+	data = packet->rawpkt + header_length;
+	data_len = len - header_length;
+	switch (protocol) {
+	case TL_PROTOCOLID_COM_DATA:
+	case TL_PROTOCOLID_COM_CTRL:
+		queue_received_packet(hw, protocol, address, data, data_len,
+				is_last);
+		break;
+	case TL_PROTOCOLID_SETUP:
+		handle_received_SETUP_packet(hw, address, data, data_len,
+				is_last);
+		break;
+	}
+}
+
+static void acknowledge_data_read(struct ipw_hardware *hw)
+{
+	if (hw->hw_version == HW_VERSION_1)
+		outw(DCR_RXDONE, hw->base_port + IODCR);
+	else
+		writew(MEMRX_PCINTACKK,
+				&hw->memory_info_regs->memreg_pc_interrupt_ack);
+}
+
+/*
+ * Retrieve a packet from the IPW hardware.
+ */
+static void do_receive_packet(struct ipw_hardware *hw)
+{
+	unsigned len;
+	unsigned i;
+	unsigned char pkt[LL_MTU_MAX];
+
+	start_timing();
+
+	if (hw->hw_version == HW_VERSION_1) {
+		len = inw(hw->base_port + IODRR);
+		if (len > hw->ll_mtu) {
+			printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+			       ": received a packet of %u bytes - longer than the MTU!\n", len);
+			outw(DCR_RXDONE | DCR_RXRESET, hw->base_port + IODCR);
+			return;
+		}
+
+		for (i = 0; i < len; i += 2) {
+			__le16 raw_data = inw(hw->base_port + IODRR);
+			unsigned short data = le16_to_cpu(raw_data);
+
+			pkt[i] = (unsigned char) data;
+			pkt[i + 1] = (unsigned char) (data >> 8);
+		}
+	} else {
+		len = inw(hw->base_port);
+		if (len > hw->ll_mtu) {
+			printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+			       ": received a packet of %u bytes - longer than the MTU!\n", len);
+			writew(MEMRX_PCINTACKK,
+				&hw->memory_info_regs->memreg_pc_interrupt_ack);
+			return;
+		}
+
+		for (i = 0; i < len; i += 2) {
+			__le16 raw_data = inw(hw->base_port);
+			unsigned short data = le16_to_cpu(raw_data);
+
+			pkt[i] = (unsigned char) data;
+			pkt[i + 1] = (unsigned char) (data >> 8);
+		}
+
+		while ((i & 3) != 2) {
+			inw(hw->base_port);
+			i += 2;
+		}
+	}
+
+	acknowledge_data_read(hw);
+
+	swap_packet_bitfield_from_le(pkt);
+
+	if (ipwireless_debug)
+		dump_data_bytes("recv", pkt, len);
+
+	handle_received_packet(hw, (union nl_packet *) pkt, len);
+
+	end_read_timing(len);
+}
+
+static int get_current_packet_priority(struct ipw_hardware *hw)
+{
+	/*
+	 * If we're initializing, don't send anything of higher priority than
+	 * PRIO_SETUP.  The network layer therefore need not care about
+	 * hardware initialization - any of its stuff will simply be queued
+	 * until setup is complete.
+	 */
+	return (hw->to_setup || hw->initializing
+			? PRIO_SETUP + 1 : NL_NUM_OF_PRIORITIES);
+}
+
+/*
+ * return 1 if something has been received from hw
+ */
+static int get_packets_from_hw(struct ipw_hardware *hw)
+{
+	int received = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	while (hw->rx_ready && !hw->blocking_rx) {
+		received = 1;
+		hw->rx_ready--;
+		spin_unlock_irqrestore(&hw->lock, flags);
+
+		do_receive_packet(hw);
+
+		spin_lock_irqsave(&hw->lock, flags);
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+	return received;
+}
+
+/*
+ * Send pending packet up to given priority, prioritize SETUP data until
+ * hardware is fully setup.
+ *
+ * return 1 if more packets can be sent
+ */
+static int send_pending_packet(struct ipw_hardware *hw, int priority_limit)
+{
+	int more_to_send = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	if (hw->tx_queued && hw->tx_ready) {
+		int priority;
+		struct ipw_tx_packet *packet = NULL;
+
+		/* Pick a packet */
+		for (priority = 0; priority < priority_limit; priority++) {
+			if (!list_empty(&hw->tx_queue[priority])) {
+				packet = list_first_entry(
+						&hw->tx_queue[priority],
+						struct ipw_tx_packet,
+						queue);
+
+				hw->tx_queued--;
+				list_del(&packet->queue);
+
+				break;
+			}
+		}
+		if (!packet) {
+			hw->tx_queued = 0;
+			spin_unlock_irqrestore(&hw->lock, flags);
+			return 0;
+		}
+
+		spin_unlock_irqrestore(&hw->lock, flags);
+
+		/* Send */
+		do_send_packet(hw, packet);
+
+		/* Check if more to send */
+		spin_lock_irqsave(&hw->lock, flags);
+		for (priority = 0; priority < priority_limit; priority++)
+			if (!list_empty(&hw->tx_queue[priority])) {
+				more_to_send = 1;
+				break;
+			}
+
+		if (!more_to_send)
+			hw->tx_queued = 0;
+	}
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+	return more_to_send;
+}
+
+/*
+ * Send and receive all queued packets.
+ */
+static void ipwireless_do_tasklet(struct tasklet_struct *t)
+{
+	struct ipw_hardware *hw = from_tasklet(hw, t, tasklet);
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	if (hw->shutting_down) {
+		spin_unlock_irqrestore(&hw->lock, flags);
+		return;
+	}
+
+	if (hw->to_setup == 1) {
+		/*
+		 * Initial setup data sent to hardware
+		 */
+		hw->to_setup = 2;
+		spin_unlock_irqrestore(&hw->lock, flags);
+
+		ipw_setup_hardware(hw);
+		ipw_send_setup_packet(hw);
+
+		send_pending_packet(hw, PRIO_SETUP + 1);
+		get_packets_from_hw(hw);
+	} else {
+		int priority_limit = get_current_packet_priority(hw);
+		int again;
+
+		spin_unlock_irqrestore(&hw->lock, flags);
+
+		do {
+			again = send_pending_packet(hw, priority_limit);
+			again |= get_packets_from_hw(hw);
+		} while (again);
+	}
+}
+
+/*
+ * return true if the card is physically present.
+ */
+static int is_card_present(struct ipw_hardware *hw)
+{
+	if (hw->hw_version == HW_VERSION_1)
+		return inw(hw->base_port + IOIR) != 0xFFFF;
+	else
+		return readl(&hw->memory_info_regs->memreg_card_present) ==
+		    CARD_PRESENT_VALUE;
+}
+
+static irqreturn_t ipwireless_handle_v1_interrupt(int irq,
+						  struct ipw_hardware *hw)
+{
+	unsigned short irqn;
+
+	irqn = inw(hw->base_port + IOIR);
+
+	/* Check if card is present */
+	if (irqn == 0xFFFF)
+		return IRQ_NONE;
+	else if (irqn != 0) {
+		unsigned short ack = 0;
+		unsigned long flags;
+
+		/* Transmit complete. */
+		if (irqn & IR_TXINTR) {
+			ack |= IR_TXINTR;
+			spin_lock_irqsave(&hw->lock, flags);
+			hw->tx_ready = 1;
+			spin_unlock_irqrestore(&hw->lock, flags);
+		}
+		/* Received data */
+		if (irqn & IR_RXINTR) {
+			ack |= IR_RXINTR;
+			spin_lock_irqsave(&hw->lock, flags);
+			hw->rx_ready++;
+			spin_unlock_irqrestore(&hw->lock, flags);
+		}
+		if (ack != 0) {
+			outw(ack, hw->base_port + IOIR);
+			tasklet_schedule(&hw->tasklet);
+		}
+		return IRQ_HANDLED;
+	}
+	return IRQ_NONE;
+}
+
+static void acknowledge_pcmcia_interrupt(struct ipw_hardware *hw)
+{
+	unsigned short csr = readw(&hw->memregs_CCR->reg_config_and_status);
+
+	csr &= 0xfffd;
+	writew(csr, &hw->memregs_CCR->reg_config_and_status);
+}
+
+static irqreturn_t ipwireless_handle_v2_v3_interrupt(int irq,
+						     struct ipw_hardware *hw)
+{
+	int tx = 0;
+	int rx = 0;
+	int rx_repeat = 0;
+	int try_mem_tx_old;
+	unsigned long flags;
+
+	do {
+
+	unsigned short memtx = readw(hw->memreg_tx);
+	unsigned short memtx_serial;
+	unsigned short memrxdone =
+		readw(&hw->memory_info_regs->memreg_rx_done);
+
+	try_mem_tx_old = 0;
+
+	/* check whether the interrupt was generated by ipwireless card */
+	if (!(memtx & MEMTX_TX) && !(memrxdone & MEMRX_RX_DONE)) {
+
+		/* check if the card uses memreg_tx_old register */
+		if (hw->memreg_tx == &hw->memory_info_regs->memreg_tx_new) {
+			memtx = readw(&hw->memory_info_regs->memreg_tx_old);
+			if (memtx & MEMTX_TX) {
+				printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+					": Using memreg_tx_old\n");
+				hw->memreg_tx =
+					&hw->memory_info_regs->memreg_tx_old;
+			} else {
+				return IRQ_NONE;
+			}
+		} else
+			return IRQ_NONE;
+	}
+
+	/*
+	 * See if the card is physically present. Note that while it is
+	 * powering up, it appears not to be present.
+	 */
+	if (!is_card_present(hw)) {
+		acknowledge_pcmcia_interrupt(hw);
+		return IRQ_HANDLED;
+	}
+
+	memtx_serial = memtx & (unsigned short) 0xff00;
+	if (memtx & MEMTX_TX) {
+		writew(memtx_serial, hw->memreg_tx);
+
+		if (hw->serial_number_detected) {
+			if (memtx_serial != hw->last_memtx_serial) {
+				hw->last_memtx_serial = memtx_serial;
+				spin_lock_irqsave(&hw->lock, flags);
+				hw->rx_ready++;
+				spin_unlock_irqrestore(&hw->lock, flags);
+				rx = 1;
+			} else
+				/* Ignore 'Timer Recovery' duplicates. */
+				rx_repeat = 1;
+		} else {
+			/*
+			 * If a non-zero serial number is seen, then enable
+			 * serial number checking.
+			 */
+			if (memtx_serial != 0) {
+				hw->serial_number_detected = 1;
+				printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
+					": memreg_tx serial num detected\n");
+
+				spin_lock_irqsave(&hw->lock, flags);
+				hw->rx_ready++;
+				spin_unlock_irqrestore(&hw->lock, flags);
+			}
+			rx = 1;
+		}
+	}
+	if (memrxdone & MEMRX_RX_DONE) {
+		writew(0, &hw->memory_info_regs->memreg_rx_done);
+		spin_lock_irqsave(&hw->lock, flags);
+		hw->tx_ready = 1;
+		spin_unlock_irqrestore(&hw->lock, flags);
+		tx = 1;
+	}
+	if (tx)
+		writew(MEMRX_PCINTACKK,
+				&hw->memory_info_regs->memreg_pc_interrupt_ack);
+
+	acknowledge_pcmcia_interrupt(hw);
+
+	if (tx || rx)
+		tasklet_schedule(&hw->tasklet);
+	else if (!rx_repeat) {
+		if (hw->memreg_tx == &hw->memory_info_regs->memreg_tx_new) {
+			if (hw->serial_number_detected)
+				printk(KERN_WARNING IPWIRELESS_PCCARD_NAME
+					": spurious interrupt - new_tx mode\n");
+			else {
+				printk(KERN_WARNING IPWIRELESS_PCCARD_NAME
+					": no valid memreg_tx value - switching to the old memreg_tx\n");
+				hw->memreg_tx =
+					&hw->memory_info_regs->memreg_tx_old;
+				try_mem_tx_old = 1;
+			}
+		} else
+			printk(KERN_WARNING IPWIRELESS_PCCARD_NAME
+					": spurious interrupt - old_tx mode\n");
+	}
+
+	} while (try_mem_tx_old == 1);
+
+	return IRQ_HANDLED;
+}
+
+irqreturn_t ipwireless_interrupt(int irq, void *dev_id)
+{
+	struct ipw_dev *ipw = dev_id;
+
+	if (ipw->hardware->hw_version == HW_VERSION_1)
+		return ipwireless_handle_v1_interrupt(irq, ipw->hardware);
+	else
+		return ipwireless_handle_v2_v3_interrupt(irq, ipw->hardware);
+}
+
+static void flush_packets_to_hw(struct ipw_hardware *hw)
+{
+	int priority_limit;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	priority_limit = get_current_packet_priority(hw);
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+	while (send_pending_packet(hw, priority_limit));
+}
+
+static void send_packet(struct ipw_hardware *hw, int priority,
+			struct ipw_tx_packet *packet)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&hw->lock, flags);
+	list_add_tail(&packet->queue, &hw->tx_queue[priority]);
+	hw->tx_queued++;
+	spin_unlock_irqrestore(&hw->lock, flags);
+
+	flush_packets_to_hw(hw);
+}
+
+/* Create data packet, non-atomic allocation */
+static void *alloc_data_packet(int data_size,
+				unsigned char dest_addr,
+				unsigned char protocol)
+{
+	struct ipw_tx_packet *packet = kzalloc(
+			sizeof(struct ipw_tx_packet) + data_size,
+			GFP_ATOMIC);
+
+	if (!packet)
+		return NULL;
+
+	INIT_LIST_HEAD(&packet->queue);
+	packet->dest_addr = dest_addr;
+	packet->protocol = protocol;
+	packet->length = data_size;
+
+	return packet;
+}
+
+static void *alloc_ctrl_packet(int header_size,
+			       unsigned char dest_addr,
+			       unsigned char protocol,
+			       unsigned char sig_no)
+{
+	/*
+	 * sig_no is located right after ipw_tx_packet struct in every
+	 * CTRL or SETUP packets, we can use ipw_control_packet as a
+	 * common struct
+	 */
+	struct ipw_control_packet *packet = kzalloc(header_size, GFP_ATOMIC);
+
+	if (!packet)
+		return NULL;
+
+	INIT_LIST_HEAD(&packet->header.queue);
+	packet->header.dest_addr = dest_addr;
+	packet->header.protocol = protocol;
+	packet->header.length = header_size - sizeof(struct ipw_tx_packet);
+	packet->body.sig_no = sig_no;
+
+	return packet;
+}
+
+int ipwireless_send_packet(struct ipw_hardware *hw, unsigned int channel_idx,
+			    const u8 *data, unsigned int length,
+			    void (*callback) (void *cb, unsigned int length),
+			    void *callback_data)
+{
+	struct ipw_tx_packet *packet;
+
+	packet = alloc_data_packet(length, (channel_idx + 1),
+			TL_PROTOCOLID_COM_DATA);
+	if (!packet)
+		return -ENOMEM;
+	packet->packet_callback = callback;
+	packet->callback_data = callback_data;
+	memcpy((unsigned char *) packet + sizeof(struct ipw_tx_packet), data,
+			length);
+
+	send_packet(hw, PRIO_DATA, packet);
+	return 0;
+}
+
+static int set_control_line(struct ipw_hardware *hw, int prio,
+			   unsigned int channel_idx, int line, int state)
+{
+	struct ipw_control_packet *packet;
+	int protocolid = TL_PROTOCOLID_COM_CTRL;
+
+	if (prio == PRIO_SETUP)
+		protocolid = TL_PROTOCOLID_SETUP;
+
+	packet = alloc_ctrl_packet(sizeof(struct ipw_control_packet),
+			(channel_idx + 1), protocolid, line);
+	if (!packet)
+		return -ENOMEM;
+	packet->header.length = sizeof(struct ipw_control_packet_body);
+	packet->body.value = (state == 0 ? 0 : 1);
+	send_packet(hw, prio, &packet->header);
+	return 0;
+}
+
+
+static int set_DTR(struct ipw_hardware *hw, int priority,
+		   unsigned int channel_idx, int state)
+{
+	if (state != 0)
+		hw->control_lines[channel_idx] |= IPW_CONTROL_LINE_DTR;
+	else
+		hw->control_lines[channel_idx] &= ~IPW_CONTROL_LINE_DTR;
+
+	return set_control_line(hw, priority, channel_idx, COMCTRL_DTR, state);
+}
+
+static int set_RTS(struct ipw_hardware *hw, int priority,
+		   unsigned int channel_idx, int state)
+{
+	if (state != 0)
+		hw->control_lines[channel_idx] |= IPW_CONTROL_LINE_RTS;
+	else
+		hw->control_lines[channel_idx] &= ~IPW_CONTROL_LINE_RTS;
+
+	return set_control_line(hw, priority, channel_idx, COMCTRL_RTS, state);
+}
+
+int ipwireless_set_DTR(struct ipw_hardware *hw, unsigned int channel_idx,
+		       int state)
+{
+	return set_DTR(hw, PRIO_CTRL, channel_idx, state);
+}
+
+int ipwireless_set_RTS(struct ipw_hardware *hw, unsigned int channel_idx,
+		       int state)
+{
+	return set_RTS(hw, PRIO_CTRL, channel_idx, state);
+}
+
+struct ipw_setup_get_version_query_packet {
+	struct ipw_tx_packet header;
+	struct tl_setup_get_version_qry body;
+};
+
+struct ipw_setup_config_packet {
+	struct ipw_tx_packet header;
+	struct tl_setup_config_msg body;
+};
+
+struct ipw_setup_config_done_packet {
+	struct ipw_tx_packet header;
+	struct tl_setup_config_done_msg body;
+};
+
+struct ipw_setup_open_packet {
+	struct ipw_tx_packet header;
+	struct tl_setup_open_msg body;
+};
+
+struct ipw_setup_info_packet {
+	struct ipw_tx_packet header;
+	struct tl_setup_info_msg body;
+};
+
+struct ipw_setup_reboot_msg_ack {
+	struct ipw_tx_packet header;
+	struct TlSetupRebootMsgAck body;
+};
+
+/* This handles the actual initialization of the card */
+static void __handle_setup_get_version_rsp(struct ipw_hardware *hw)
+{
+	struct ipw_setup_config_packet *config_packet;
+	struct ipw_setup_config_done_packet *config_done_packet;
+	struct ipw_setup_open_packet *open_packet;
+	struct ipw_setup_info_packet *info_packet;
+	int port;
+	unsigned int channel_idx;
+
+	/* generate config packet */
+	for (port = 1; port <= NL_NUM_OF_ADDRESSES; port++) {
+		config_packet = alloc_ctrl_packet(
+				sizeof(struct ipw_setup_config_packet),
+				ADDR_SETUP_PROT,
+				TL_PROTOCOLID_SETUP,
+				TL_SETUP_SIGNO_CONFIG_MSG);
+		if (!config_packet)
+			goto exit_nomem;
+		config_packet->header.length = sizeof(struct tl_setup_config_msg);
+		config_packet->body.port_no = port;
+		config_packet->body.prio_data = PRIO_DATA;
+		config_packet->body.prio_ctrl = PRIO_CTRL;
+		send_packet(hw, PRIO_SETUP, &config_packet->header);
+	}
+	config_done_packet = alloc_ctrl_packet(
+			sizeof(struct ipw_setup_config_done_packet),
+			ADDR_SETUP_PROT,
+			TL_PROTOCOLID_SETUP,
+			TL_SETUP_SIGNO_CONFIG_DONE_MSG);
+	if (!config_done_packet)
+		goto exit_nomem;
+	config_done_packet->header.length = sizeof(struct tl_setup_config_done_msg);
+	send_packet(hw, PRIO_SETUP, &config_done_packet->header);
+
+	/* generate open packet */
+	for (port = 1; port <= NL_NUM_OF_ADDRESSES; port++) {
+		open_packet = alloc_ctrl_packet(
+				sizeof(struct ipw_setup_open_packet),
+				ADDR_SETUP_PROT,
+				TL_PROTOCOLID_SETUP,
+				TL_SETUP_SIGNO_OPEN_MSG);
+		if (!open_packet)
+			goto exit_nomem;
+		open_packet->header.length = sizeof(struct tl_setup_open_msg);
+		open_packet->body.port_no = port;
+		send_packet(hw, PRIO_SETUP, &open_packet->header);
+	}
+	for (channel_idx = 0;
+			channel_idx < NL_NUM_OF_ADDRESSES; channel_idx++) {
+		int ret;
+
+		ret = set_DTR(hw, PRIO_SETUP, channel_idx,
+			(hw->control_lines[channel_idx] &
+			 IPW_CONTROL_LINE_DTR) != 0);
+		if (ret) {
+			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+					": error setting DTR (%d)\n", ret);
+			return;
+		}
+
+		ret = set_RTS(hw, PRIO_SETUP, channel_idx,
+			(hw->control_lines [channel_idx] &
+			 IPW_CONTROL_LINE_RTS) != 0);
+		if (ret) {
+			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+					": error setting RTS (%d)\n", ret);
+			return;
+		}
+	}
+	/*
+	 * For NDIS we assume that we are using sync PPP frames, for COM async.
+	 * This driver uses NDIS mode too. We don't bother with translation
+	 * from async -> sync PPP.
+	 */
+	info_packet = alloc_ctrl_packet(sizeof(struct ipw_setup_info_packet),
+			ADDR_SETUP_PROT,
+			TL_PROTOCOLID_SETUP,
+			TL_SETUP_SIGNO_INFO_MSG);
+	if (!info_packet)
+		goto exit_nomem;
+	info_packet->header.length = sizeof(struct tl_setup_info_msg);
+	info_packet->body.driver_type = NDISWAN_DRIVER;
+	info_packet->body.major_version = NDISWAN_DRIVER_MAJOR_VERSION;
+	info_packet->body.minor_version = NDISWAN_DRIVER_MINOR_VERSION;
+	send_packet(hw, PRIO_SETUP, &info_packet->header);
+
+	/* Initialization is now complete, so we clear the 'to_setup' flag */
+	hw->to_setup = 0;
+
+	return;
+
+exit_nomem:
+	printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+			": not enough memory to alloc control packet\n");
+	hw->to_setup = -1;
+}
+
+static void handle_setup_get_version_rsp(struct ipw_hardware *hw,
+		unsigned char vers_no)
+{
+	del_timer(&hw->setup_timer);
+	hw->initializing = 0;
+	printk(KERN_INFO IPWIRELESS_PCCARD_NAME ": card is ready.\n");
+
+	if (vers_no == TL_SETUP_VERSION)
+		__handle_setup_get_version_rsp(hw);
+	else
+		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+				": invalid hardware version no %u\n",
+				(unsigned int) vers_no);
+}
+
+static void ipw_send_setup_packet(struct ipw_hardware *hw)
+{
+	struct ipw_setup_get_version_query_packet *ver_packet;
+
+	ver_packet = alloc_ctrl_packet(
+			sizeof(struct ipw_setup_get_version_query_packet),
+			ADDR_SETUP_PROT, TL_PROTOCOLID_SETUP,
+			TL_SETUP_SIGNO_GET_VERSION_QRY);
+	if (!ver_packet)
+		return;
+	ver_packet->header.length = sizeof(struct tl_setup_get_version_qry);
+
+	/*
+	 * Response is handled in handle_received_SETUP_packet
+	 */
+	send_packet(hw, PRIO_SETUP, &ver_packet->header);
+}
+
+static void handle_received_SETUP_packet(struct ipw_hardware *hw,
+					 unsigned int address,
+					 const unsigned char *data, int len,
+					 int is_last)
+{
+	const union ipw_setup_rx_msg *rx_msg = (const union ipw_setup_rx_msg *) data;
+
+	if (address != ADDR_SETUP_PROT) {
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		       ": setup packet has bad address %d\n", address);
+		return;
+	}
+
+	switch (rx_msg->sig_no) {
+	case TL_SETUP_SIGNO_GET_VERSION_RSP:
+		if (hw->to_setup)
+			handle_setup_get_version_rsp(hw,
+					rx_msg->version_rsp_msg.version);
+		break;
+
+	case TL_SETUP_SIGNO_OPEN_MSG:
+		if (ipwireless_debug) {
+			unsigned int channel_idx = rx_msg->open_msg.port_no - 1;
+
+			printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+			       ": OPEN_MSG [channel %u] reply received\n",
+			       channel_idx);
+		}
+		break;
+
+	case TL_SETUP_SIGNO_INFO_MSG_ACK:
+		if (ipwireless_debug)
+			printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
+			       ": card successfully configured as NDISWAN\n");
+		break;
+
+	case TL_SETUP_SIGNO_REBOOT_MSG:
+		if (hw->to_setup)
+			printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
+			       ": Setup not completed - ignoring reboot msg\n");
+		else {
+			struct ipw_setup_reboot_msg_ack *packet;
+
+			printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
+			       ": Acknowledging REBOOT message\n");
+			packet = alloc_ctrl_packet(
+					sizeof(struct ipw_setup_reboot_msg_ack),
+					ADDR_SETUP_PROT, TL_PROTOCOLID_SETUP,
+					TL_SETUP_SIGNO_REBOOT_MSG_ACK);
+			if (!packet) {
+				pr_err(IPWIRELESS_PCCARD_NAME
+				       ": Not enough memory to send reboot packet");
+				break;
+			}
+			packet->header.length =
+				sizeof(struct TlSetupRebootMsgAck);
+			send_packet(hw, PRIO_SETUP, &packet->header);
+			if (hw->reboot_callback)
+				hw->reboot_callback(hw->reboot_callback_data);
+		}
+		break;
+
+	default:
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		       ": unknown setup message %u received\n",
+		       (unsigned int) rx_msg->sig_no);
+	}
+}
+
+static void do_close_hardware(struct ipw_hardware *hw)
+{
+	unsigned int irqn;
+
+	if (hw->hw_version == HW_VERSION_1) {
+		/* Disable TX and RX interrupts. */
+		outw(0, hw->base_port + IOIER);
+
+		/* Acknowledge any outstanding interrupt requests */
+		irqn = inw(hw->base_port + IOIR);
+		if (irqn & IR_TXINTR)
+			outw(IR_TXINTR, hw->base_port + IOIR);
+		if (irqn & IR_RXINTR)
+			outw(IR_RXINTR, hw->base_port + IOIR);
+
+		synchronize_irq(hw->irq);
+	}
+}
+
+struct ipw_hardware *ipwireless_hardware_create(void)
+{
+	int i;
+	struct ipw_hardware *hw =
+		kzalloc(sizeof(struct ipw_hardware), GFP_KERNEL);
+
+	if (!hw)
+		return NULL;
+
+	hw->irq = -1;
+	hw->initializing = 1;
+	hw->tx_ready = 1;
+	hw->rx_bytes_queued = 0;
+	hw->rx_pool_size = 0;
+	hw->last_memtx_serial = (unsigned short) 0xffff;
+	for (i = 0; i < NL_NUM_OF_PRIORITIES; i++)
+		INIT_LIST_HEAD(&hw->tx_queue[i]);
+
+	INIT_LIST_HEAD(&hw->rx_queue);
+	INIT_LIST_HEAD(&hw->rx_pool);
+	spin_lock_init(&hw->lock);
+	tasklet_setup(&hw->tasklet, ipwireless_do_tasklet);
+	INIT_WORK(&hw->work_rx, ipw_receive_data_work);
+	timer_setup(&hw->setup_timer, ipwireless_setup_timer, 0);
+
+	return hw;
+}
+
+void ipwireless_init_hardware_v1(struct ipw_hardware *hw,
+		unsigned int base_port,
+		void __iomem *attr_memory,
+		void __iomem *common_memory,
+		int is_v2_card,
+		void (*reboot_callback) (void *data),
+		void *reboot_callback_data)
+{
+	if (hw->removed) {
+		hw->removed = 0;
+		enable_irq(hw->irq);
+	}
+	hw->base_port = base_port;
+	hw->hw_version = (is_v2_card ? HW_VERSION_2 : HW_VERSION_1);
+	hw->ll_mtu = (hw->hw_version == HW_VERSION_1 ? LL_MTU_V1 : LL_MTU_V2);
+	hw->memregs_CCR = (struct MEMCCR __iomem *)
+			((unsigned short __iomem *) attr_memory + 0x200);
+	hw->memory_info_regs = (struct MEMINFREG __iomem *) common_memory;
+	hw->memreg_tx = &hw->memory_info_regs->memreg_tx_new;
+	hw->reboot_callback = reboot_callback;
+	hw->reboot_callback_data = reboot_callback_data;
+}
+
+void ipwireless_init_hardware_v2_v3(struct ipw_hardware *hw)
+{
+	hw->initializing = 1;
+	hw->init_loops = 0;
+	printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+	       ": waiting for card to start up...\n");
+	ipwireless_setup_timer(&hw->setup_timer);
+}
+
+static void ipwireless_setup_timer(struct timer_list *t)
+{
+	struct ipw_hardware *hw = from_timer(hw, t, setup_timer);
+
+	hw->init_loops++;
+
+	if (hw->init_loops == TL_SETUP_MAX_VERSION_QRY &&
+			hw->hw_version == HW_VERSION_2 &&
+			hw->memreg_tx == &hw->memory_info_regs->memreg_tx_new) {
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+				": failed to startup using TX2, trying TX\n");
+
+		hw->memreg_tx = &hw->memory_info_regs->memreg_tx_old;
+		hw->init_loops = 0;
+	}
+	/* Give up after a certain number of retries */
+	if (hw->init_loops == TL_SETUP_MAX_VERSION_QRY) {
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		       ": card failed to start up!\n");
+		hw->initializing = 0;
+	} else {
+		/* Do not attempt to write to the board if it is not present. */
+		if (is_card_present(hw)) {
+			unsigned long flags;
+
+			spin_lock_irqsave(&hw->lock, flags);
+			hw->to_setup = 1;
+			hw->tx_ready = 1;
+			spin_unlock_irqrestore(&hw->lock, flags);
+			tasklet_schedule(&hw->tasklet);
+		}
+
+		mod_timer(&hw->setup_timer,
+			jiffies + msecs_to_jiffies(TL_SETUP_VERSION_QRY_TMO));
+	}
+}
+
+/*
+ * Stop any interrupts from executing so that, once this function returns,
+ * other layers of the driver can be sure they won't get any more callbacks.
+ * Thus must be called on a proper process context.
+ */
+void ipwireless_stop_interrupts(struct ipw_hardware *hw)
+{
+	if (!hw->shutting_down) {
+		/* Tell everyone we are going down. */
+		hw->shutting_down = 1;
+		del_timer(&hw->setup_timer);
+
+		/* Prevent the hardware from sending any more interrupts */
+		do_close_hardware(hw);
+	}
+}
+
+void ipwireless_hardware_free(struct ipw_hardware *hw)
+{
+	int i;
+	struct ipw_rx_packet *rp, *rq;
+	struct ipw_tx_packet *tp, *tq;
+
+	ipwireless_stop_interrupts(hw);
+
+	flush_work(&hw->work_rx);
+
+	for (i = 0; i < NL_NUM_OF_ADDRESSES; i++)
+		kfree(hw->packet_assembler[i]);
+
+	for (i = 0; i < NL_NUM_OF_PRIORITIES; i++)
+		list_for_each_entry_safe(tp, tq, &hw->tx_queue[i], queue) {
+			list_del(&tp->queue);
+			kfree(tp);
+		}
+
+	list_for_each_entry_safe(rp, rq, &hw->rx_queue, queue) {
+		list_del(&rp->queue);
+		kfree(rp);
+	}
+
+	list_for_each_entry_safe(rp, rq, &hw->rx_pool, queue) {
+		list_del(&rp->queue);
+		kfree(rp);
+	}
+	kfree(hw);
+}
+
+/*
+ * Associate the specified network with this hardware, so it will receive events
+ * from it.
+ */
+void ipwireless_associate_network(struct ipw_hardware *hw,
+				  struct ipw_network *network)
+{
+	hw->network = network;
+}
diff --git a/drivers/tty/ipwireless/hardware.h b/drivers/tty/ipwireless/hardware.h
new file mode 100644
index 000000000..e524a8fcc
--- /dev/null
+++ b/drivers/tty/ipwireless/hardware.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#ifndef _IPWIRELESS_CS_HARDWARE_H_
+#define _IPWIRELESS_CS_HARDWARE_H_
+
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+
+#define IPW_CONTROL_LINE_CTS 0x0001
+#define IPW_CONTROL_LINE_DCD 0x0002
+#define IPW_CONTROL_LINE_DSR 0x0004
+#define IPW_CONTROL_LINE_RI  0x0008
+#define IPW_CONTROL_LINE_DTR 0x0010
+#define IPW_CONTROL_LINE_RTS 0x0020
+
+struct ipw_hardware;
+struct ipw_network;
+
+struct ipw_hardware *ipwireless_hardware_create(void);
+void ipwireless_hardware_free(struct ipw_hardware *hw);
+irqreturn_t ipwireless_interrupt(int irq, void *dev_id);
+int ipwireless_set_DTR(struct ipw_hardware *hw, unsigned int channel_idx,
+		int state);
+int ipwireless_set_RTS(struct ipw_hardware *hw, unsigned int channel_idx,
+		int state);
+int ipwireless_send_packet(struct ipw_hardware *hw,
+			    unsigned int channel_idx,
+			    const unsigned char *data,
+			    unsigned int length,
+			    void (*packet_sent_callback) (void *cb,
+							  unsigned int length),
+			    void *sent_cb_data);
+void ipwireless_associate_network(struct ipw_hardware *hw,
+		struct ipw_network *net);
+void ipwireless_stop_interrupts(struct ipw_hardware *hw);
+void ipwireless_init_hardware_v1(struct ipw_hardware *hw,
+				 unsigned int base_port,
+				 void __iomem *attr_memory,
+				 void __iomem *common_memory,
+				 int is_v2_card,
+				 void (*reboot_cb) (void *data),
+				 void *reboot_cb_data);
+void ipwireless_init_hardware_v2_v3(struct ipw_hardware *hw);
+void ipwireless_sleep(unsigned int tenths);
+
+#endif
diff --git a/drivers/tty/ipwireless/main.c b/drivers/tty/ipwireless/main.c
new file mode 100644
index 000000000..4c18bbfe1
--- /dev/null
+++ b/drivers/tty/ipwireless/main.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#include "hardware.h"
+#include "network.h"
+#include "main.h"
+#include "tty.h"
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <pcmcia/cisreg.h>
+#include <pcmcia/device_id.h>
+#include <pcmcia/ss.h>
+#include <pcmcia/ds.h>
+
+static const struct pcmcia_device_id ipw_ids[] = {
+	PCMCIA_DEVICE_MANF_CARD(0x02f2, 0x0100),
+	PCMCIA_DEVICE_MANF_CARD(0x02f2, 0x0200),
+	PCMCIA_DEVICE_NULL
+};
+MODULE_DEVICE_TABLE(pcmcia, ipw_ids);
+
+static void ipwireless_detach(struct pcmcia_device *link);
+
+/*
+ * Module params
+ */
+/* Debug mode: more verbose, print sent/recv bytes */
+int ipwireless_debug;
+int ipwireless_loopback;
+int ipwireless_out_queue = 10;
+
+module_param_named(debug, ipwireless_debug, int, 0);
+module_param_named(loopback, ipwireless_loopback, int, 0);
+module_param_named(out_queue, ipwireless_out_queue, int, 0);
+MODULE_PARM_DESC(debug, "switch on debug messages [0]");
+MODULE_PARM_DESC(loopback,
+		"debug: enable ras_raw channel [0]");
+MODULE_PARM_DESC(out_queue, "debug: set size of outgoing PPP queue [10]");
+
+/* Executes in process context. */
+static void signalled_reboot_work(struct work_struct *work_reboot)
+{
+	struct ipw_dev *ipw = container_of(work_reboot, struct ipw_dev,
+			work_reboot);
+	struct pcmcia_device *link = ipw->link;
+	pcmcia_reset_card(link->socket);
+}
+
+static void signalled_reboot_callback(void *callback_data)
+{
+	struct ipw_dev *ipw = (struct ipw_dev *) callback_data;
+
+	/* Delegate to process context. */
+	schedule_work(&ipw->work_reboot);
+}
+
+static int ipwireless_probe(struct pcmcia_device *p_dev, void *priv_data)
+{
+	struct ipw_dev *ipw = priv_data;
+	int ret;
+
+	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
+	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_AUTO;
+
+	/* 0x40 causes it to generate level mode interrupts. */
+	/* 0x04 enables IREQ pin. */
+	p_dev->config_index |= 0x44;
+	p_dev->io_lines = 16;
+	ret = pcmcia_request_io(p_dev);
+	if (ret)
+		return ret;
+
+	if (!request_region(p_dev->resource[0]->start,
+			    resource_size(p_dev->resource[0]),
+			    IPWIRELESS_PCCARD_NAME)) {
+		ret = -EBUSY;
+		goto exit;
+	}
+
+	p_dev->resource[2]->flags |=
+		WIN_DATA_WIDTH_16 | WIN_MEMORY_TYPE_CM | WIN_ENABLE;
+
+	ret = pcmcia_request_window(p_dev, p_dev->resource[2], 0);
+	if (ret != 0)
+		goto exit1;
+
+	ret = pcmcia_map_mem_page(p_dev, p_dev->resource[2], p_dev->card_addr);
+	if (ret != 0)
+		goto exit1;
+
+	ipw->is_v2_card = resource_size(p_dev->resource[2]) == 0x100;
+
+	ipw->common_memory = ioremap(p_dev->resource[2]->start,
+				resource_size(p_dev->resource[2]));
+	if (!ipw->common_memory) {
+		ret = -ENOMEM;
+		goto exit1;
+	}
+	if (!request_mem_region(p_dev->resource[2]->start,
+				resource_size(p_dev->resource[2]),
+				IPWIRELESS_PCCARD_NAME)) {
+		ret = -EBUSY;
+		goto exit2;
+	}
+
+	p_dev->resource[3]->flags |= WIN_DATA_WIDTH_16 | WIN_MEMORY_TYPE_AM |
+					WIN_ENABLE;
+	p_dev->resource[3]->end = 0; /* this used to be 0x1000 */
+	ret = pcmcia_request_window(p_dev, p_dev->resource[3], 0);
+	if (ret != 0)
+		goto exit3;
+
+	ret = pcmcia_map_mem_page(p_dev, p_dev->resource[3], 0);
+	if (ret != 0)
+		goto exit3;
+
+	ipw->attr_memory = ioremap(p_dev->resource[3]->start,
+				resource_size(p_dev->resource[3]));
+	if (!ipw->attr_memory) {
+		ret = -ENOMEM;
+		goto exit3;
+	}
+	if (!request_mem_region(p_dev->resource[3]->start,
+				resource_size(p_dev->resource[3]),
+				IPWIRELESS_PCCARD_NAME)) {
+		ret = -EBUSY;
+		goto exit4;
+	}
+
+	return 0;
+
+exit4:
+	iounmap(ipw->attr_memory);
+exit3:
+	release_mem_region(p_dev->resource[2]->start,
+			resource_size(p_dev->resource[2]));
+exit2:
+	iounmap(ipw->common_memory);
+exit1:
+	release_region(p_dev->resource[0]->start,
+		       resource_size(p_dev->resource[0]));
+exit:
+	pcmcia_disable_device(p_dev);
+	return ret;
+}
+
+static int config_ipwireless(struct ipw_dev *ipw)
+{
+	struct pcmcia_device *link = ipw->link;
+	int ret = 0;
+
+	ipw->is_v2_card = 0;
+	link->config_flags |= CONF_AUTO_SET_IO | CONF_AUTO_SET_IOMEM |
+		CONF_ENABLE_IRQ;
+
+	ret = pcmcia_loop_config(link, ipwireless_probe, ipw);
+	if (ret != 0)
+		return ret;
+
+	INIT_WORK(&ipw->work_reboot, signalled_reboot_work);
+
+	ipwireless_init_hardware_v1(ipw->hardware, link->resource[0]->start,
+				    ipw->attr_memory, ipw->common_memory,
+				    ipw->is_v2_card, signalled_reboot_callback,
+				    ipw);
+
+	ret = pcmcia_request_irq(link, ipwireless_interrupt);
+	if (ret != 0)
+		goto exit;
+
+	printk(KERN_INFO IPWIRELESS_PCCARD_NAME ": Card type %s\n",
+			ipw->is_v2_card ? "V2/V3" : "V1");
+	printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		": I/O ports %pR, irq %d\n", link->resource[0],
+			(unsigned int) link->irq);
+	if (ipw->attr_memory && ipw->common_memory)
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+			": attr memory %pR, common memory %pR\n",
+			link->resource[3],
+			link->resource[2]);
+
+	ipw->network = ipwireless_network_create(ipw->hardware);
+	if (!ipw->network)
+		goto exit;
+
+	ipw->tty = ipwireless_tty_create(ipw->hardware, ipw->network);
+	if (!ipw->tty)
+		goto exit;
+
+	ipwireless_init_hardware_v2_v3(ipw->hardware);
+
+	/*
+	 * Do the RequestConfiguration last, because it enables interrupts.
+	 * Then we don't get any interrupts before we're ready for them.
+	 */
+	ret = pcmcia_enable_device(link);
+	if (ret != 0)
+		goto exit;
+
+	return 0;
+
+exit:
+	if (ipw->common_memory) {
+		release_mem_region(link->resource[2]->start,
+				resource_size(link->resource[2]));
+		iounmap(ipw->common_memory);
+	}
+	if (ipw->attr_memory) {
+		release_mem_region(link->resource[3]->start,
+				resource_size(link->resource[3]));
+		iounmap(ipw->attr_memory);
+	}
+	pcmcia_disable_device(link);
+	return -1;
+}
+
+static void release_ipwireless(struct ipw_dev *ipw)
+{
+	release_region(ipw->link->resource[0]->start,
+		       resource_size(ipw->link->resource[0]));
+	if (ipw->common_memory) {
+		release_mem_region(ipw->link->resource[2]->start,
+				resource_size(ipw->link->resource[2]));
+		iounmap(ipw->common_memory);
+	}
+	if (ipw->attr_memory) {
+		release_mem_region(ipw->link->resource[3]->start,
+				resource_size(ipw->link->resource[3]));
+		iounmap(ipw->attr_memory);
+	}
+	pcmcia_disable_device(ipw->link);
+}
+
+/*
+ * ipwireless_attach() creates an "instance" of the driver, allocating
+ * local data structures for one device (one interface).  The device
+ * is registered with Card Services.
+ *
+ * The pcmcia_device structure is initialized, but we don't actually
+ * configure the card at this point -- we wait until we receive a
+ * card insertion event.
+ */
+static int ipwireless_attach(struct pcmcia_device *link)
+{
+	struct ipw_dev *ipw;
+	int ret;
+
+	ipw = kzalloc(sizeof(struct ipw_dev), GFP_KERNEL);
+	if (!ipw)
+		return -ENOMEM;
+
+	ipw->link = link;
+	link->priv = ipw;
+
+	ipw->hardware = ipwireless_hardware_create();
+	if (!ipw->hardware) {
+		kfree(ipw);
+		return -ENOMEM;
+	}
+	/* RegisterClient will call config_ipwireless */
+
+	ret = config_ipwireless(ipw);
+
+	if (ret != 0) {
+		ipwireless_detach(link);
+		return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * This deletes a driver "instance".  The device is de-registered with
+ * Card Services.  If it has been released, all local data structures
+ * are freed.  Otherwise, the structures will be freed when the device
+ * is released.
+ */
+static void ipwireless_detach(struct pcmcia_device *link)
+{
+	struct ipw_dev *ipw = link->priv;
+
+	release_ipwireless(ipw);
+
+	if (ipw->tty != NULL)
+		ipwireless_tty_free(ipw->tty);
+	if (ipw->network != NULL)
+		ipwireless_network_free(ipw->network);
+	if (ipw->hardware != NULL)
+		ipwireless_hardware_free(ipw->hardware);
+	kfree(ipw);
+}
+
+static struct pcmcia_driver me = {
+	.owner		= THIS_MODULE,
+	.probe          = ipwireless_attach,
+	.remove         = ipwireless_detach,
+	.name		= IPWIRELESS_PCCARD_NAME,
+	.id_table       = ipw_ids
+};
+
+/*
+ * Module insertion : initialisation of the module.
+ * Register the card with cardmgr...
+ */
+static int __init init_ipwireless(void)
+{
+	int ret;
+
+	ret = ipwireless_tty_init();
+	if (ret != 0)
+		return ret;
+
+	ret = pcmcia_register_driver(&me);
+	if (ret != 0)
+		ipwireless_tty_release();
+
+	return ret;
+}
+
+/*
+ * Module removal
+ */
+static void __exit exit_ipwireless(void)
+{
+	pcmcia_unregister_driver(&me);
+	ipwireless_tty_release();
+}
+
+module_init(init_ipwireless);
+module_exit(exit_ipwireless);
+
+MODULE_AUTHOR(IPWIRELESS_PCMCIA_AUTHOR);
+MODULE_DESCRIPTION(IPWIRELESS_PCCARD_NAME " " IPWIRELESS_PCMCIA_VERSION);
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/ipwireless/main.h b/drivers/tty/ipwireless/main.h
new file mode 100644
index 000000000..73818bb64
--- /dev/null
+++ b/drivers/tty/ipwireless/main.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#ifndef _IPWIRELESS_CS_H_
+#define _IPWIRELESS_CS_H_
+
+#include <linux/sched.h>
+#include <linux/types.h>
+
+#include <pcmcia/cistpl.h>
+#include <pcmcia/ds.h>
+
+#include "hardware.h"
+
+#define IPWIRELESS_PCCARD_NAME		"ipwireless"
+#define IPWIRELESS_PCMCIA_VERSION	"1.1"
+#define IPWIRELESS_PCMCIA_AUTHOR        \
+	"Stephen Blackheath, Ben Martel, Jiri Kosina and David Sterba"
+
+#define IPWIRELESS_TX_QUEUE_SIZE  262144
+#define IPWIRELESS_RX_QUEUE_SIZE  262144
+
+#define IPWIRELESS_STATE_DEBUG
+
+struct ipw_hardware;
+struct ipw_network;
+struct ipw_tty;
+
+struct ipw_dev {
+	struct pcmcia_device *link;
+	int is_v2_card;
+
+	void __iomem *attr_memory;
+
+	void __iomem *common_memory;
+
+	/* Reference to attribute memory, containing CIS data */
+	void *attribute_memory;
+
+	/* Hardware context */
+	struct ipw_hardware *hardware;
+	/* Network layer context */
+	struct ipw_network *network;
+	/* TTY device context */
+	struct ipw_tty *tty;
+	struct work_struct work_reboot;
+};
+
+/* Module parametres */
+extern int ipwireless_debug;
+extern int ipwireless_loopback;
+extern int ipwireless_out_queue;
+
+#endif
diff --git a/drivers/tty/ipwireless/network.c b/drivers/tty/ipwireless/network.c
new file mode 100644
index 000000000..fe569f629
--- /dev/null
+++ b/drivers/tty/ipwireless/network.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/ppp_channel.h>
+#include <linux/ppp_defs.h>
+#include <linux/slab.h>
+#include <linux/ppp-ioctl.h>
+#include <linux/skbuff.h>
+
+#include "network.h"
+#include "hardware.h"
+#include "main.h"
+#include "tty.h"
+
+#define MAX_ASSOCIATED_TTYS 2
+
+#define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
+
+struct ipw_network {
+	/* Hardware context, used for calls to hardware layer. */
+	struct ipw_hardware *hardware;
+	/* Context for kernel 'generic_ppp' functionality */
+	struct ppp_channel *ppp_channel;
+	/* tty context connected with IPW console */
+	struct ipw_tty *associated_ttys[NO_OF_IPW_CHANNELS][MAX_ASSOCIATED_TTYS];
+	/* True if ppp needs waking up once we're ready to xmit */
+	int ppp_blocked;
+	/* Number of packets queued up in hardware module. */
+	int outgoing_packets_queued;
+	/* Spinlock to avoid interrupts during shutdown */
+	spinlock_t lock;
+	struct mutex close_lock;
+
+	/* PPP ioctl data, not actually used anywere */
+	unsigned int flags;
+	unsigned int rbits;
+	u32 xaccm[8];
+	u32 raccm;
+	int mru;
+
+	int shutting_down;
+	unsigned int ras_control_lines;
+
+	struct work_struct work_go_online;
+	struct work_struct work_go_offline;
+};
+
+static void notify_packet_sent(void *callback_data, unsigned int packet_length)
+{
+	struct ipw_network *network = callback_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&network->lock, flags);
+	network->outgoing_packets_queued--;
+	if (network->ppp_channel != NULL) {
+		if (network->ppp_blocked) {
+			network->ppp_blocked = 0;
+			spin_unlock_irqrestore(&network->lock, flags);
+			ppp_output_wakeup(network->ppp_channel);
+			if (ipwireless_debug)
+				printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
+				       ": ppp unblocked\n");
+		} else
+			spin_unlock_irqrestore(&network->lock, flags);
+	} else
+		spin_unlock_irqrestore(&network->lock, flags);
+}
+
+/*
+ * Called by the ppp system when it has a packet to send to the hardware.
+ */
+static int ipwireless_ppp_start_xmit(struct ppp_channel *ppp_channel,
+				     struct sk_buff *skb)
+{
+	struct ipw_network *network = ppp_channel->private;
+	unsigned long flags;
+
+	spin_lock_irqsave(&network->lock, flags);
+	if (network->outgoing_packets_queued < ipwireless_out_queue) {
+		unsigned char *buf;
+		static unsigned char header[] = {
+			PPP_ALLSTATIONS, /* 0xff */
+			PPP_UI,		 /* 0x03 */
+		};
+		int ret;
+
+		network->outgoing_packets_queued++;
+		spin_unlock_irqrestore(&network->lock, flags);
+
+		/*
+		 * If we have the requested amount of headroom in the skb we
+		 * were handed, then we can add the header efficiently.
+		 */
+		if (skb_headroom(skb) >= 2) {
+			memcpy(skb_push(skb, 2), header, 2);
+			ret = ipwireless_send_packet(network->hardware,
+					       IPW_CHANNEL_RAS, skb->data,
+					       skb->len,
+					       notify_packet_sent,
+					       network);
+			if (ret < 0) {
+				skb_pull(skb, 2);
+				return 0;
+			}
+		} else {
+			/* Otherwise (rarely) we do it inefficiently. */
+			buf = kmalloc(skb->len + 2, GFP_ATOMIC);
+			if (!buf)
+				return 0;
+			memcpy(buf + 2, skb->data, skb->len);
+			memcpy(buf, header, 2);
+			ret = ipwireless_send_packet(network->hardware,
+					       IPW_CHANNEL_RAS, buf,
+					       skb->len + 2,
+					       notify_packet_sent,
+					       network);
+			kfree(buf);
+			if (ret < 0)
+				return 0;
+		}
+		kfree_skb(skb);
+		return 1;
+	} else {
+		/*
+		 * Otherwise reject the packet, and flag that the ppp system
+		 * needs to be unblocked once we are ready to send.
+		 */
+		network->ppp_blocked = 1;
+		spin_unlock_irqrestore(&network->lock, flags);
+		if (ipwireless_debug)
+			printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": ppp blocked\n");
+		return 0;
+	}
+}
+
+/* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
+static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
+				unsigned int cmd, unsigned long arg)
+{
+	struct ipw_network *network = ppp_channel->private;
+	int err, val;
+	u32 accm[8];
+	int __user *user_arg = (int __user *) arg;
+
+	err = -EFAULT;
+	switch (cmd) {
+	case PPPIOCGFLAGS:
+		val = network->flags | network->rbits;
+		if (put_user(val, user_arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCSFLAGS:
+		if (get_user(val, user_arg))
+			break;
+		network->flags = val & ~SC_RCV_BITS;
+		network->rbits = val & SC_RCV_BITS;
+		err = 0;
+		break;
+
+	case PPPIOCGASYNCMAP:
+		if (put_user(network->xaccm[0], user_arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCSASYNCMAP:
+		if (get_user(network->xaccm[0], user_arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCGRASYNCMAP:
+		if (put_user(network->raccm, user_arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCSRASYNCMAP:
+		if (get_user(network->raccm, user_arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCGXASYNCMAP:
+		if (copy_to_user((void __user *) arg, network->xaccm,
+					sizeof(network->xaccm)))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCSXASYNCMAP:
+		if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
+			break;
+		accm[2] &= ~0x40000000U;	/* can't escape 0x5e */
+		accm[3] |= 0x60000000U;	/* must escape 0x7d, 0x7e */
+		memcpy(network->xaccm, accm, sizeof(network->xaccm));
+		err = 0;
+		break;
+
+	case PPPIOCGMRU:
+		if (put_user(network->mru, user_arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCSMRU:
+		if (get_user(val, user_arg))
+			break;
+		if (val < PPP_MRU)
+			val = PPP_MRU;
+		network->mru = val;
+		err = 0;
+		break;
+
+	default:
+		err = -ENOTTY;
+	}
+
+	return err;
+}
+
+static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
+	.start_xmit = ipwireless_ppp_start_xmit,
+	.ioctl      = ipwireless_ppp_ioctl
+};
+
+static void do_go_online(struct work_struct *work_go_online)
+{
+	struct ipw_network *network =
+		container_of(work_go_online, struct ipw_network,
+				work_go_online);
+	unsigned long flags;
+
+	spin_lock_irqsave(&network->lock, flags);
+	if (!network->ppp_channel) {
+		struct ppp_channel *channel;
+
+		spin_unlock_irqrestore(&network->lock, flags);
+		channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
+		if (!channel) {
+			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+					": unable to allocate PPP channel\n");
+			return;
+		}
+		channel->private = network;
+		channel->mtu = 16384;	/* Wild guess */
+		channel->hdrlen = 2;
+		channel->ops = &ipwireless_ppp_channel_ops;
+
+		network->flags = 0;
+		network->rbits = 0;
+		network->mru = PPP_MRU;
+		memset(network->xaccm, 0, sizeof(network->xaccm));
+		network->xaccm[0] = ~0U;
+		network->xaccm[3] = 0x60000000U;
+		network->raccm = ~0U;
+		if (ppp_register_channel(channel) < 0) {
+			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+					": unable to register PPP channel\n");
+			kfree(channel);
+			return;
+		}
+		spin_lock_irqsave(&network->lock, flags);
+		network->ppp_channel = channel;
+	}
+	spin_unlock_irqrestore(&network->lock, flags);
+}
+
+static void do_go_offline(struct work_struct *work_go_offline)
+{
+	struct ipw_network *network =
+		container_of(work_go_offline, struct ipw_network,
+				work_go_offline);
+	unsigned long flags;
+
+	mutex_lock(&network->close_lock);
+	spin_lock_irqsave(&network->lock, flags);
+	if (network->ppp_channel != NULL) {
+		struct ppp_channel *channel = network->ppp_channel;
+
+		network->ppp_channel = NULL;
+		spin_unlock_irqrestore(&network->lock, flags);
+		mutex_unlock(&network->close_lock);
+		ppp_unregister_channel(channel);
+	} else {
+		spin_unlock_irqrestore(&network->lock, flags);
+		mutex_unlock(&network->close_lock);
+	}
+}
+
+void ipwireless_network_notify_control_line_change(struct ipw_network *network,
+						   unsigned int channel_idx,
+						   unsigned int control_lines,
+						   unsigned int changed_mask)
+{
+	int i;
+
+	if (channel_idx == IPW_CHANNEL_RAS)
+		network->ras_control_lines = control_lines;
+
+	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
+		struct ipw_tty *tty =
+			network->associated_ttys[channel_idx][i];
+
+		/*
+		 * If it's associated with a tty (other than the RAS channel
+		 * when we're online), then send the data to that tty.  The RAS
+		 * channel's data is handled above - it always goes through
+		 * ppp_generic.
+		 */
+		if (tty)
+			ipwireless_tty_notify_control_line_change(tty,
+								  channel_idx,
+								  control_lines,
+								  changed_mask);
+	}
+}
+
+/*
+ * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
+ * bytes, which are required on sent packet, but not always present on received
+ * packets
+ */
+static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
+					       unsigned int length)
+{
+	struct sk_buff *skb;
+
+	if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
+		length -= 2;
+		data += 2;
+	}
+
+	skb = dev_alloc_skb(length + 4);
+	if (skb == NULL)
+		return NULL;
+	skb_reserve(skb, 2);
+	skb_put_data(skb, data, length);
+
+	return skb;
+}
+
+void ipwireless_network_packet_received(struct ipw_network *network,
+					unsigned int channel_idx,
+					unsigned char *data,
+					unsigned int length)
+{
+	int i;
+	unsigned long flags;
+
+	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
+		struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
+
+		if (!tty)
+			continue;
+
+		/*
+		 * If it's associated with a tty (other than the RAS channel
+		 * when we're online), then send the data to that tty.  The RAS
+		 * channel's data is handled above - it always goes through
+		 * ppp_generic.
+		 */
+		if (channel_idx == IPW_CHANNEL_RAS
+				&& (network->ras_control_lines &
+					IPW_CONTROL_LINE_DCD) != 0
+				&& ipwireless_tty_is_modem(tty)) {
+			/*
+			 * If data came in on the RAS channel and this tty is
+			 * the modem tty, and we are online, then we send it to
+			 * the PPP layer.
+			 */
+			mutex_lock(&network->close_lock);
+			spin_lock_irqsave(&network->lock, flags);
+			if (network->ppp_channel != NULL) {
+				struct sk_buff *skb;
+
+				spin_unlock_irqrestore(&network->lock,
+						flags);
+
+				/* Send the data to the ppp_generic module. */
+				skb = ipw_packet_received_skb(data, length);
+				if (skb)
+					ppp_input(network->ppp_channel, skb);
+			} else
+				spin_unlock_irqrestore(&network->lock,
+						flags);
+			mutex_unlock(&network->close_lock);
+		}
+		/* Otherwise we send it out the tty. */
+		else
+			ipwireless_tty_received(tty, data, length);
+	}
+}
+
+struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
+{
+	struct ipw_network *network =
+		kzalloc(sizeof(struct ipw_network), GFP_KERNEL);
+
+	if (!network)
+		return NULL;
+
+	spin_lock_init(&network->lock);
+	mutex_init(&network->close_lock);
+
+	network->hardware = hw;
+
+	INIT_WORK(&network->work_go_online, do_go_online);
+	INIT_WORK(&network->work_go_offline, do_go_offline);
+
+	ipwireless_associate_network(hw, network);
+
+	return network;
+}
+
+void ipwireless_network_free(struct ipw_network *network)
+{
+	network->shutting_down = 1;
+
+	ipwireless_ppp_close(network);
+	flush_work(&network->work_go_online);
+	flush_work(&network->work_go_offline);
+
+	ipwireless_stop_interrupts(network->hardware);
+	ipwireless_associate_network(network->hardware, NULL);
+
+	kfree(network);
+}
+
+void ipwireless_associate_network_tty(struct ipw_network *network,
+				      unsigned int channel_idx,
+				      struct ipw_tty *tty)
+{
+	int i;
+
+	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
+		if (network->associated_ttys[channel_idx][i] == NULL) {
+			network->associated_ttys[channel_idx][i] = tty;
+			break;
+		}
+}
+
+void ipwireless_disassociate_network_ttys(struct ipw_network *network,
+					  unsigned int channel_idx)
+{
+	int i;
+
+	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
+		network->associated_ttys[channel_idx][i] = NULL;
+}
+
+void ipwireless_ppp_open(struct ipw_network *network)
+{
+	if (ipwireless_debug)
+		printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
+	schedule_work(&network->work_go_online);
+}
+
+void ipwireless_ppp_close(struct ipw_network *network)
+{
+	/* Disconnect from the wireless network. */
+	if (ipwireless_debug)
+		printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
+	schedule_work(&network->work_go_offline);
+}
+
+int ipwireless_ppp_channel_index(struct ipw_network *network)
+{
+	int ret = -1;
+	unsigned long flags;
+
+	spin_lock_irqsave(&network->lock, flags);
+	if (network->ppp_channel != NULL)
+		ret = ppp_channel_index(network->ppp_channel);
+	spin_unlock_irqrestore(&network->lock, flags);
+
+	return ret;
+}
+
+int ipwireless_ppp_unit_number(struct ipw_network *network)
+{
+	int ret = -1;
+	unsigned long flags;
+
+	spin_lock_irqsave(&network->lock, flags);
+	if (network->ppp_channel != NULL)
+		ret = ppp_unit_number(network->ppp_channel);
+	spin_unlock_irqrestore(&network->lock, flags);
+
+	return ret;
+}
+
+int ipwireless_ppp_mru(const struct ipw_network *network)
+{
+	return network->mru;
+}
diff --git a/drivers/tty/ipwireless/network.h b/drivers/tty/ipwireless/network.h
new file mode 100644
index 000000000..784932a59
--- /dev/null
+++ b/drivers/tty/ipwireless/network.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#ifndef _IPWIRELESS_CS_NETWORK_H_
+#define _IPWIRELESS_CS_NETWORK_H_
+
+#include <linux/types.h>
+
+struct ipw_network;
+struct ipw_tty;
+struct ipw_hardware;
+
+/* Definitions of the different channels on the PCMCIA UE */
+#define IPW_CHANNEL_RAS      0
+#define IPW_CHANNEL_DIALLER  1
+#define IPW_CHANNEL_CONSOLE  2
+#define NO_OF_IPW_CHANNELS   5
+
+void ipwireless_network_notify_control_line_change(struct ipw_network *net,
+		unsigned int channel_idx, unsigned int control_lines,
+		unsigned int control_mask);
+void ipwireless_network_packet_received(struct ipw_network *net,
+		unsigned int channel_idx, unsigned char *data,
+		unsigned int length);
+struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw);
+void ipwireless_network_free(struct ipw_network *net);
+void ipwireless_associate_network_tty(struct ipw_network *net,
+		unsigned int channel_idx, struct ipw_tty *tty);
+void ipwireless_disassociate_network_ttys(struct ipw_network *net,
+		unsigned int channel_idx);
+
+void ipwireless_ppp_open(struct ipw_network *net);
+
+void ipwireless_ppp_close(struct ipw_network *net);
+int ipwireless_ppp_channel_index(struct ipw_network *net);
+int ipwireless_ppp_unit_number(struct ipw_network *net);
+int ipwireless_ppp_mru(const struct ipw_network *net);
+
+#endif
diff --git a/drivers/tty/ipwireless/setup_protocol.h b/drivers/tty/ipwireless/setup_protocol.h
new file mode 100644
index 000000000..d4a7ae257
--- /dev/null
+++ b/drivers/tty/ipwireless/setup_protocol.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#ifndef _IPWIRELESS_CS_SETUP_PROTOCOL_H_
+#define _IPWIRELESS_CS_SETUP_PROTOCOL_H_
+
+/* Version of the setup protocol and transport protocols */
+#define TL_SETUP_VERSION		1
+
+#define TL_SETUP_VERSION_QRY_TMO	1000
+#define TL_SETUP_MAX_VERSION_QRY	30
+
+/* Message numbers 0-9 are obsoleted and must not be reused! */
+#define TL_SETUP_SIGNO_GET_VERSION_QRY	10
+#define TL_SETUP_SIGNO_GET_VERSION_RSP	11
+#define TL_SETUP_SIGNO_CONFIG_MSG	12
+#define TL_SETUP_SIGNO_CONFIG_DONE_MSG	13
+#define TL_SETUP_SIGNO_OPEN_MSG		14
+#define TL_SETUP_SIGNO_CLOSE_MSG	15
+
+#define TL_SETUP_SIGNO_INFO_MSG     20
+#define TL_SETUP_SIGNO_INFO_MSG_ACK 21
+
+#define TL_SETUP_SIGNO_REBOOT_MSG      22
+#define TL_SETUP_SIGNO_REBOOT_MSG_ACK  23
+
+/* Synchronous start-messages */
+struct tl_setup_get_version_qry {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_GET_VERSION_QRY */
+} __attribute__ ((__packed__));
+
+struct tl_setup_get_version_rsp {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_GET_VERSION_RSP */
+	unsigned char version;		/* TL_SETUP_VERSION */
+} __attribute__ ((__packed__));
+
+struct tl_setup_config_msg {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_CONFIG_MSG */
+	unsigned char port_no;
+	unsigned char prio_data;
+	unsigned char prio_ctrl;
+} __attribute__ ((__packed__));
+
+struct tl_setup_config_done_msg {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_CONFIG_DONE_MSG */
+} __attribute__ ((__packed__));
+
+/* Asynchronous messages */
+struct tl_setup_open_msg {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_OPEN_MSG */
+	unsigned char port_no;
+} __attribute__ ((__packed__));
+
+struct tl_setup_close_msg {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_CLOSE_MSG */
+	unsigned char port_no;
+} __attribute__ ((__packed__));
+
+/* Driver type  - for use in tl_setup_info_msg.driver_type */
+#define COMM_DRIVER     0
+#define NDISWAN_DRIVER  1
+#define NDISWAN_DRIVER_MAJOR_VERSION  2
+#define NDISWAN_DRIVER_MINOR_VERSION  0
+
+/*
+ * It should not matter when this message comes over as we just store the
+ * results and send the ACK.
+ */
+struct tl_setup_info_msg {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_INFO_MSG */
+	unsigned char driver_type;
+	unsigned char major_version;
+	unsigned char minor_version;
+} __attribute__ ((__packed__));
+
+struct tl_setup_info_msgAck {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_INFO_MSG_ACK */
+} __attribute__ ((__packed__));
+
+struct TlSetupRebootMsgAck {
+	unsigned char sig_no;		/* TL_SETUP_SIGNO_REBOOT_MSG_ACK */
+} __attribute__ ((__packed__));
+
+/* Define a union of all the msgs that the driver can receive from the card.*/
+union ipw_setup_rx_msg {
+	unsigned char sig_no;
+	struct tl_setup_get_version_rsp version_rsp_msg;
+	struct tl_setup_open_msg open_msg;
+	struct tl_setup_close_msg close_msg;
+	struct tl_setup_info_msg InfoMsg;
+	struct tl_setup_info_msgAck info_msg_ack;
+} __attribute__ ((__packed__));
+
+#endif				/* _IPWIRELESS_CS_SETUP_PROTOCOL_H_ */
diff --git a/drivers/tty/ipwireless/tty.c b/drivers/tty/ipwireless/tty.c
new file mode 100644
index 000000000..b6de40815
--- /dev/null
+++ b/drivers/tty/ipwireless/tty.c
@@ -0,0 +1,627 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/ppp_defs.h>
+#include <linux/if.h>
+#include <linux/ppp-ioctl.h>
+#include <linux/sched.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/uaccess.h>
+
+#include "tty.h"
+#include "network.h"
+#include "hardware.h"
+#include "main.h"
+
+#define IPWIRELESS_PCMCIA_START 	(0)
+#define IPWIRELESS_PCMCIA_MINORS	(24)
+#define IPWIRELESS_PCMCIA_MINOR_RANGE	(8)
+
+#define TTYTYPE_MODEM    (0)
+#define TTYTYPE_MONITOR  (1)
+#define TTYTYPE_RAS_RAW  (2)
+
+struct ipw_tty {
+	struct tty_port port;
+	int index;
+	struct ipw_hardware *hardware;
+	unsigned int channel_idx;
+	unsigned int secondary_channel_idx;
+	int tty_type;
+	struct ipw_network *network;
+	unsigned int control_lines;
+	struct mutex ipw_tty_mutex;
+	int tx_bytes_queued;
+};
+
+static struct ipw_tty *ttys[IPWIRELESS_PCMCIA_MINORS];
+
+static struct tty_driver *ipw_tty_driver;
+
+static char *tty_type_name(int tty_type)
+{
+	static char *channel_names[] = {
+		"modem",
+		"monitor",
+		"RAS-raw"
+	};
+
+	return channel_names[tty_type];
+}
+
+static struct ipw_tty *get_tty(int index)
+{
+	/*
+	 * The 'ras_raw' channel is only available when 'loopback' mode
+	 * is enabled.
+	 * Number of minor starts with 16 (_RANGE * _RAS_RAW).
+	 */
+	if (!ipwireless_loopback && index >=
+			 IPWIRELESS_PCMCIA_MINOR_RANGE * TTYTYPE_RAS_RAW)
+		return NULL;
+
+	return ttys[index];
+}
+
+static int ipw_open(struct tty_struct *linux_tty, struct file *filp)
+{
+	struct ipw_tty *tty = get_tty(linux_tty->index);
+
+	if (!tty)
+		return -ENODEV;
+
+	mutex_lock(&tty->ipw_tty_mutex);
+	if (tty->port.count == 0)
+		tty->tx_bytes_queued = 0;
+
+	tty->port.count++;
+
+	tty->port.tty = linux_tty;
+	linux_tty->driver_data = tty;
+
+	if (tty->tty_type == TTYTYPE_MODEM)
+		ipwireless_ppp_open(tty->network);
+
+	mutex_unlock(&tty->ipw_tty_mutex);
+
+	return 0;
+}
+
+static void do_ipw_close(struct ipw_tty *tty)
+{
+	tty->port.count--;
+
+	if (tty->port.count == 0) {
+		struct tty_struct *linux_tty = tty->port.tty;
+
+		if (linux_tty != NULL) {
+			tty->port.tty = NULL;
+			linux_tty->driver_data = NULL;
+
+			if (tty->tty_type == TTYTYPE_MODEM)
+				ipwireless_ppp_close(tty->network);
+		}
+	}
+}
+
+static void ipw_hangup(struct tty_struct *linux_tty)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+
+	if (!tty)
+		return;
+
+	mutex_lock(&tty->ipw_tty_mutex);
+	if (tty->port.count == 0) {
+		mutex_unlock(&tty->ipw_tty_mutex);
+		return;
+	}
+
+	do_ipw_close(tty);
+
+	mutex_unlock(&tty->ipw_tty_mutex);
+}
+
+static void ipw_close(struct tty_struct *linux_tty, struct file *filp)
+{
+	ipw_hangup(linux_tty);
+}
+
+/* Take data received from hardware, and send it out the tty */
+void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
+			unsigned int length)
+{
+	int work = 0;
+
+	mutex_lock(&tty->ipw_tty_mutex);
+
+	if (!tty->port.count) {
+		mutex_unlock(&tty->ipw_tty_mutex);
+		return;
+	}
+	mutex_unlock(&tty->ipw_tty_mutex);
+
+	work = tty_insert_flip_string(&tty->port, data, length);
+
+	if (work != length)
+		printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
+				": %d chars not inserted to flip buffer!\n",
+				length - work);
+
+	if (work)
+		tty_flip_buffer_push(&tty->port);
+}
+
+static void ipw_write_packet_sent_callback(void *callback_data,
+					   unsigned int packet_length)
+{
+	struct ipw_tty *tty = callback_data;
+
+	/*
+	 * Packet has been sent, so we subtract the number of bytes from our
+	 * tally of outstanding TX bytes.
+	 */
+	tty->tx_bytes_queued -= packet_length;
+}
+
+static ssize_t ipw_write(struct tty_struct *linux_tty, const u8 *buf,
+			 size_t count)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+	int room, ret;
+
+	if (!tty)
+		return -ENODEV;
+
+	mutex_lock(&tty->ipw_tty_mutex);
+	if (!tty->port.count) {
+		mutex_unlock(&tty->ipw_tty_mutex);
+		return -EINVAL;
+	}
+
+	room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
+	if (room < 0)
+		room = 0;
+	/* Don't allow caller to write any more than we have room for */
+	if (count > room)
+		count = room;
+
+	if (count == 0) {
+		mutex_unlock(&tty->ipw_tty_mutex);
+		return 0;
+	}
+
+	ret = ipwireless_send_packet(tty->hardware, IPW_CHANNEL_RAS,
+			       buf, count,
+			       ipw_write_packet_sent_callback, tty);
+	if (ret < 0) {
+		mutex_unlock(&tty->ipw_tty_mutex);
+		return 0;
+	}
+
+	tty->tx_bytes_queued += count;
+	mutex_unlock(&tty->ipw_tty_mutex);
+
+	return count;
+}
+
+static unsigned int ipw_write_room(struct tty_struct *linux_tty)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+	int room;
+
+	/* FIXME: Exactly how is the tty object locked here .. */
+	if (!tty)
+		return 0;
+
+	if (!tty->port.count)
+		return 0;
+
+	room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
+	if (room < 0)
+		room = 0;
+
+	return room;
+}
+
+static int ipwireless_get_serial_info(struct tty_struct *linux_tty,
+				      struct serial_struct *ss)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+
+	if (!tty)
+		return -ENODEV;
+
+	if (!tty->port.count)
+		return -EINVAL;
+
+	ss->type = PORT_UNKNOWN;
+	ss->line = tty->index;
+	ss->baud_base = 115200;
+	return 0;
+}
+
+static int ipwireless_set_serial_info(struct tty_struct *linux_tty,
+				      struct serial_struct *ss)
+{
+	return 0;	/* Keeps the PCMCIA scripts happy. */
+}
+
+static unsigned int ipw_chars_in_buffer(struct tty_struct *linux_tty)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+
+	if (!tty)
+		return 0;
+
+	if (!tty->port.count)
+		return 0;
+
+	return tty->tx_bytes_queued;
+}
+
+static int get_control_lines(struct ipw_tty *tty)
+{
+	unsigned int my = tty->control_lines;
+	unsigned int out = 0;
+
+	if (my & IPW_CONTROL_LINE_RTS)
+		out |= TIOCM_RTS;
+	if (my & IPW_CONTROL_LINE_DTR)
+		out |= TIOCM_DTR;
+	if (my & IPW_CONTROL_LINE_CTS)
+		out |= TIOCM_CTS;
+	if (my & IPW_CONTROL_LINE_DSR)
+		out |= TIOCM_DSR;
+	if (my & IPW_CONTROL_LINE_DCD)
+		out |= TIOCM_CD;
+
+	return out;
+}
+
+static int set_control_lines(struct ipw_tty *tty, unsigned int set,
+			     unsigned int clear)
+{
+	int ret;
+
+	if (set & TIOCM_RTS) {
+		ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
+		if (ret)
+			return ret;
+		if (tty->secondary_channel_idx != -1) {
+			ret = ipwireless_set_RTS(tty->hardware,
+					  tty->secondary_channel_idx, 1);
+			if (ret)
+				return ret;
+		}
+	}
+	if (set & TIOCM_DTR) {
+		ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
+		if (ret)
+			return ret;
+		if (tty->secondary_channel_idx != -1) {
+			ret = ipwireless_set_DTR(tty->hardware,
+					  tty->secondary_channel_idx, 1);
+			if (ret)
+				return ret;
+		}
+	}
+	if (clear & TIOCM_RTS) {
+		ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
+		if (tty->secondary_channel_idx != -1) {
+			ret = ipwireless_set_RTS(tty->hardware,
+					  tty->secondary_channel_idx, 0);
+			if (ret)
+				return ret;
+		}
+	}
+	if (clear & TIOCM_DTR) {
+		ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
+		if (tty->secondary_channel_idx != -1) {
+			ret = ipwireless_set_DTR(tty->hardware,
+					  tty->secondary_channel_idx, 0);
+			if (ret)
+				return ret;
+		}
+	}
+	return 0;
+}
+
+static int ipw_tiocmget(struct tty_struct *linux_tty)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+	/* FIXME: Exactly how is the tty object locked here .. */
+
+	if (!tty)
+		return -ENODEV;
+
+	if (!tty->port.count)
+		return -EINVAL;
+
+	return get_control_lines(tty);
+}
+
+static int
+ipw_tiocmset(struct tty_struct *linux_tty,
+	     unsigned int set, unsigned int clear)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+	/* FIXME: Exactly how is the tty object locked here .. */
+
+	if (!tty)
+		return -ENODEV;
+
+	if (!tty->port.count)
+		return -EINVAL;
+
+	return set_control_lines(tty, set, clear);
+}
+
+static int ipw_ioctl(struct tty_struct *linux_tty,
+		     unsigned int cmd, unsigned long arg)
+{
+	struct ipw_tty *tty = linux_tty->driver_data;
+
+	if (!tty)
+		return -ENODEV;
+
+	if (!tty->port.count)
+		return -EINVAL;
+
+	/* FIXME: Exactly how is the tty object locked here .. */
+	if (tty->tty_type == TTYTYPE_MODEM) {
+		switch (cmd) {
+		case PPPIOCGCHAN:
+			{
+				int chan = ipwireless_ppp_channel_index(
+							tty->network);
+
+				if (chan < 0)
+					return -ENODEV;
+				if (put_user(chan, (int __user *) arg))
+					return -EFAULT;
+			}
+			return 0;
+
+		case PPPIOCGUNIT:
+			{
+				int unit = ipwireless_ppp_unit_number(
+						tty->network);
+
+				if (unit < 0)
+					return -ENODEV;
+				if (put_user(unit, (int __user *) arg))
+					return -EFAULT;
+			}
+			return 0;
+
+		case FIONREAD:
+			{
+				int val = 0;
+
+				if (put_user(val, (int __user *) arg))
+					return -EFAULT;
+			}
+			return 0;
+		case TCFLSH:
+			return tty_perform_flush(linux_tty, arg);
+		}
+	}
+	return -ENOIOCTLCMD;
+}
+
+static int add_tty(int j,
+		    struct ipw_hardware *hardware,
+		    struct ipw_network *network, int channel_idx,
+		    int secondary_channel_idx, int tty_type)
+{
+	ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
+	if (!ttys[j])
+		return -ENOMEM;
+	ttys[j]->index = j;
+	ttys[j]->hardware = hardware;
+	ttys[j]->channel_idx = channel_idx;
+	ttys[j]->secondary_channel_idx = secondary_channel_idx;
+	ttys[j]->network = network;
+	ttys[j]->tty_type = tty_type;
+	mutex_init(&ttys[j]->ipw_tty_mutex);
+	tty_port_init(&ttys[j]->port);
+
+	tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
+	ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
+
+	if (secondary_channel_idx != -1)
+		ipwireless_associate_network_tty(network,
+						 secondary_channel_idx,
+						 ttys[j]);
+	/* check if we provide raw device (if loopback is enabled) */
+	if (get_tty(j))
+		printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+		       ": registering %s device ttyIPWp%d\n",
+		       tty_type_name(tty_type), j);
+
+	return 0;
+}
+
+struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
+				      struct ipw_network *network)
+{
+	int i, j;
+
+	for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
+		int allfree = 1;
+
+		for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
+				j += IPWIRELESS_PCMCIA_MINOR_RANGE)
+			if (ttys[j] != NULL) {
+				allfree = 0;
+				break;
+			}
+
+		if (allfree) {
+			j = i;
+
+			if (add_tty(j, hardware, network,
+					IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
+					TTYTYPE_MODEM))
+				return NULL;
+
+			j += IPWIRELESS_PCMCIA_MINOR_RANGE;
+			if (add_tty(j, hardware, network,
+					IPW_CHANNEL_DIALLER, -1,
+					TTYTYPE_MONITOR))
+				return NULL;
+
+			j += IPWIRELESS_PCMCIA_MINOR_RANGE;
+			if (add_tty(j, hardware, network,
+					IPW_CHANNEL_RAS, -1,
+					TTYTYPE_RAS_RAW))
+				return NULL;
+
+			return ttys[i];
+		}
+	}
+	return NULL;
+}
+
+/*
+ * Must be called before ipwireless_network_free().
+ */
+void ipwireless_tty_free(struct ipw_tty *tty)
+{
+	int j;
+	struct ipw_network *network = ttys[tty->index]->network;
+
+	for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
+			j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
+		struct ipw_tty *ttyj = ttys[j];
+
+		if (ttyj) {
+			mutex_lock(&ttyj->ipw_tty_mutex);
+			if (get_tty(j))
+				printk(KERN_INFO IPWIRELESS_PCCARD_NAME
+				       ": deregistering %s device ttyIPWp%d\n",
+				       tty_type_name(ttyj->tty_type), j);
+			if (ttyj->port.tty != NULL) {
+				mutex_unlock(&ttyj->ipw_tty_mutex);
+				tty_vhangup(ttyj->port.tty);
+				/* FIXME: Exactly how is the tty object locked here
+				   against a parallel ioctl etc */
+				/* FIXME2: hangup does not mean all processes
+				 * are gone */
+				mutex_lock(&ttyj->ipw_tty_mutex);
+			}
+			while (ttyj->port.count)
+				do_ipw_close(ttyj);
+			ipwireless_disassociate_network_ttys(network,
+							     ttyj->channel_idx);
+			tty_unregister_device(ipw_tty_driver, j);
+			tty_port_destroy(&ttyj->port);
+			ttys[j] = NULL;
+			mutex_unlock(&ttyj->ipw_tty_mutex);
+			kfree(ttyj);
+		}
+	}
+}
+
+static const struct tty_operations tty_ops = {
+	.open = ipw_open,
+	.close = ipw_close,
+	.hangup = ipw_hangup,
+	.write = ipw_write,
+	.write_room = ipw_write_room,
+	.ioctl = ipw_ioctl,
+	.chars_in_buffer = ipw_chars_in_buffer,
+	.tiocmget = ipw_tiocmget,
+	.tiocmset = ipw_tiocmset,
+	.set_serial = ipwireless_set_serial_info,
+	.get_serial = ipwireless_get_serial_info,
+};
+
+int ipwireless_tty_init(void)
+{
+	int result;
+
+	ipw_tty_driver = tty_alloc_driver(IPWIRELESS_PCMCIA_MINORS,
+			TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(ipw_tty_driver))
+		return PTR_ERR(ipw_tty_driver);
+
+	ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
+	ipw_tty_driver->name = "ttyIPWp";
+	ipw_tty_driver->major = 0;
+	ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
+	ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+	ipw_tty_driver->init_termios = tty_std_termios;
+	ipw_tty_driver->init_termios.c_cflag =
+	    B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	ipw_tty_driver->init_termios.c_ispeed = 9600;
+	ipw_tty_driver->init_termios.c_ospeed = 9600;
+	tty_set_operations(ipw_tty_driver, &tty_ops);
+	result = tty_register_driver(ipw_tty_driver);
+	if (result) {
+		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
+		       ": failed to register tty driver\n");
+		tty_driver_kref_put(ipw_tty_driver);
+		return result;
+	}
+
+	return 0;
+}
+
+void ipwireless_tty_release(void)
+{
+	tty_unregister_driver(ipw_tty_driver);
+	tty_driver_kref_put(ipw_tty_driver);
+}
+
+int ipwireless_tty_is_modem(struct ipw_tty *tty)
+{
+	return tty->tty_type == TTYTYPE_MODEM;
+}
+
+void
+ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
+					  unsigned int channel_idx,
+					  unsigned int control_lines,
+					  unsigned int changed_mask)
+{
+	unsigned int old_control_lines = tty->control_lines;
+
+	tty->control_lines = (tty->control_lines & ~changed_mask)
+		| (control_lines & changed_mask);
+
+	/*
+	 * If DCD is de-asserted, we close the tty so pppd can tell that we
+	 * have gone offline.
+	 */
+	if ((old_control_lines & IPW_CONTROL_LINE_DCD)
+			&& !(tty->control_lines & IPW_CONTROL_LINE_DCD)
+			&& tty->port.tty) {
+		tty_hangup(tty->port.tty);
+	}
+}
+
diff --git a/drivers/tty/ipwireless/tty.h b/drivers/tty/ipwireless/tty.h
new file mode 100644
index 000000000..ec698d9f3
--- /dev/null
+++ b/drivers/tty/ipwireless/tty.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * IPWireless 3G PCMCIA Network Driver
+ *
+ * Original code
+ *   by Stephen Blackheath <stephen@blacksapphire.com>,
+ *      Ben Martel <benm@symmetric.co.nz>
+ *
+ * Copyrighted as follows:
+ *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
+ *
+ * Various driver changes and rewrites, port to new kernels
+ *   Copyright (C) 2006-2007 Jiri Kosina
+ *
+ * Misc code cleanups and updates
+ *   Copyright (C) 2007 David Sterba
+ */
+
+#ifndef _IPWIRELESS_CS_TTY_H_
+#define _IPWIRELESS_CS_TTY_H_
+
+#include <linux/types.h>
+#include <linux/sched.h>
+
+#include <pcmcia/cistpl.h>
+#include <pcmcia/ds.h>
+
+struct ipw_tty;
+struct ipw_network;
+struct ipw_hardware;
+
+int ipwireless_tty_init(void);
+void ipwireless_tty_release(void);
+
+struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hw,
+				      struct ipw_network *net);
+void ipwireless_tty_free(struct ipw_tty *tty);
+void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
+			     unsigned int length);
+int ipwireless_tty_is_modem(struct ipw_tty *tty);
+void ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
+					       unsigned int channel_idx,
+					       unsigned int control_lines,
+					       unsigned int changed_mask);
+
+#endif
diff --git a/drivers/tty/mips_ejtag_fdc.c b/drivers/tty/mips_ejtag_fdc.c
new file mode 100644
index 000000000..369ec71c2
--- /dev/null
+++ b/drivers/tty/mips_ejtag_fdc.c
@@ -0,0 +1,1270 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TTY driver for MIPS EJTAG Fast Debug Channels.
+ *
+ * Copyright (C) 2007-2015 Imagination Technologies Ltd
+ */
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kgdb.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/uaccess.h>
+
+#include <asm/cdmm.h>
+#include <asm/irq.h>
+
+/* Register offsets */
+#define REG_FDACSR	0x00	/* FDC Access Control and Status Register */
+#define REG_FDCFG	0x08	/* FDC Configuration Register */
+#define REG_FDSTAT	0x10	/* FDC Status Register */
+#define REG_FDRX	0x18	/* FDC Receive Register */
+#define REG_FDTX(N)	(0x20+0x8*(N))	/* FDC Transmit Register n (0..15) */
+
+/* Register fields */
+
+#define REG_FDCFG_TXINTTHRES_SHIFT	18
+#define REG_FDCFG_TXINTTHRES		(0x3 << REG_FDCFG_TXINTTHRES_SHIFT)
+#define REG_FDCFG_TXINTTHRES_DISABLED	(0x0 << REG_FDCFG_TXINTTHRES_SHIFT)
+#define REG_FDCFG_TXINTTHRES_EMPTY	(0x1 << REG_FDCFG_TXINTTHRES_SHIFT)
+#define REG_FDCFG_TXINTTHRES_NOTFULL	(0x2 << REG_FDCFG_TXINTTHRES_SHIFT)
+#define REG_FDCFG_TXINTTHRES_NEAREMPTY	(0x3 << REG_FDCFG_TXINTTHRES_SHIFT)
+#define REG_FDCFG_RXINTTHRES_SHIFT	16
+#define REG_FDCFG_RXINTTHRES		(0x3 << REG_FDCFG_RXINTTHRES_SHIFT)
+#define REG_FDCFG_RXINTTHRES_DISABLED	(0x0 << REG_FDCFG_RXINTTHRES_SHIFT)
+#define REG_FDCFG_RXINTTHRES_FULL	(0x1 << REG_FDCFG_RXINTTHRES_SHIFT)
+#define REG_FDCFG_RXINTTHRES_NOTEMPTY	(0x2 << REG_FDCFG_RXINTTHRES_SHIFT)
+#define REG_FDCFG_RXINTTHRES_NEARFULL	(0x3 << REG_FDCFG_RXINTTHRES_SHIFT)
+#define REG_FDCFG_TXFIFOSIZE_SHIFT	8
+#define REG_FDCFG_TXFIFOSIZE		(0xff << REG_FDCFG_TXFIFOSIZE_SHIFT)
+#define REG_FDCFG_RXFIFOSIZE_SHIFT	0
+#define REG_FDCFG_RXFIFOSIZE		(0xff << REG_FDCFG_RXFIFOSIZE_SHIFT)
+
+#define REG_FDSTAT_TXCOUNT_SHIFT	24
+#define REG_FDSTAT_TXCOUNT		(0xff << REG_FDSTAT_TXCOUNT_SHIFT)
+#define REG_FDSTAT_RXCOUNT_SHIFT	16
+#define REG_FDSTAT_RXCOUNT		(0xff << REG_FDSTAT_RXCOUNT_SHIFT)
+#define REG_FDSTAT_RXCHAN_SHIFT		4
+#define REG_FDSTAT_RXCHAN		(0xf << REG_FDSTAT_RXCHAN_SHIFT)
+#define REG_FDSTAT_RXE			BIT(3)	/* Rx Empty */
+#define REG_FDSTAT_RXF			BIT(2)	/* Rx Full */
+#define REG_FDSTAT_TXE			BIT(1)	/* Tx Empty */
+#define REG_FDSTAT_TXF			BIT(0)	/* Tx Full */
+
+/* Default channel for the early console */
+#define CONSOLE_CHANNEL      1
+
+#define NUM_TTY_CHANNELS     16
+
+#define RX_BUF_SIZE 1024
+
+/*
+ * When the IRQ is unavailable, the FDC state must be polled for incoming data
+ * and space becoming available in TX FIFO.
+ */
+#define FDC_TTY_POLL (HZ / 50)
+
+struct mips_ejtag_fdc_tty;
+
+/**
+ * struct mips_ejtag_fdc_tty_port - Wrapper struct for FDC tty_port.
+ * @port:		TTY port data
+ * @driver:		TTY driver.
+ * @rx_lock:		Lock for rx_buf.
+ *			This protects between the hard interrupt and user
+ *			context. It's also held during read SWITCH operations.
+ * @rx_buf:		Read buffer.
+ * @xmit_lock:		Lock for xmit_*, and port.xmit_buf.
+ *			This protects between user context and kernel thread.
+ *			It is used from chars_in_buffer()/write_room() TTY
+ *			callbacks which are used during wait operations, so a
+ *			mutex is unsuitable.
+ * @xmit_cnt:		Size of xmit buffer contents.
+ * @xmit_head:		Head of xmit buffer where data is written.
+ * @xmit_tail:		Tail of xmit buffer where data is read.
+ * @xmit_empty:		Completion for xmit buffer being empty.
+ */
+struct mips_ejtag_fdc_tty_port {
+	struct tty_port			 port;
+	struct mips_ejtag_fdc_tty	*driver;
+	raw_spinlock_t			 rx_lock;
+	void				*rx_buf;
+	spinlock_t			 xmit_lock;
+	unsigned int			 xmit_cnt;
+	unsigned int			 xmit_head;
+	unsigned int			 xmit_tail;
+	struct completion		 xmit_empty;
+};
+
+/**
+ * struct mips_ejtag_fdc_tty - Driver data for FDC as a whole.
+ * @dev:		FDC device (for dev_*() logging).
+ * @driver:		TTY driver.
+ * @cpu:		CPU number for this FDC.
+ * @fdc_name:		FDC name (not for base of channel names).
+ * @driver_name:	Base of driver name.
+ * @ports:		Per-channel data.
+ * @waitqueue:		Wait queue for waiting for TX data, or for space in TX
+ *			FIFO.
+ * @lock:		Lock to protect FDCFG (interrupt enable).
+ * @thread:		KThread for writing out data to FDC.
+ * @reg:		FDC registers.
+ * @tx_fifo:		TX FIFO size.
+ * @xmit_size:		Size of each port's xmit buffer.
+ * @xmit_total:		Total number of bytes (from all ports) to transmit.
+ * @xmit_next:		Next port number to transmit from (round robin).
+ * @xmit_full:		Indicates TX FIFO is full, we're waiting for space.
+ * @irq:		IRQ number (negative if no IRQ).
+ * @removing:		Indicates the device is being removed and @poll_timer
+ *			should not be restarted.
+ * @poll_timer:		Timer for polling for interrupt events when @irq < 0.
+ * @sysrq_pressed:	Whether the magic sysrq key combination has been
+ *			detected. See mips_ejtag_fdc_handle().
+ */
+struct mips_ejtag_fdc_tty {
+	struct device			*dev;
+	struct tty_driver		*driver;
+	unsigned int			 cpu;
+	char				 fdc_name[16];
+	char				 driver_name[16];
+	struct mips_ejtag_fdc_tty_port	 ports[NUM_TTY_CHANNELS];
+	wait_queue_head_t		 waitqueue;
+	raw_spinlock_t			 lock;
+	struct task_struct		*thread;
+
+	void __iomem			*reg;
+	u8				 tx_fifo;
+
+	unsigned int			 xmit_size;
+	atomic_t			 xmit_total;
+	unsigned int			 xmit_next;
+	bool				 xmit_full;
+
+	int				 irq;
+	bool				 removing;
+	struct timer_list		 poll_timer;
+
+#ifdef CONFIG_MAGIC_SYSRQ
+	bool				 sysrq_pressed;
+#endif
+};
+
+/* Hardware access */
+
+static inline void mips_ejtag_fdc_write(struct mips_ejtag_fdc_tty *priv,
+					unsigned int offs, unsigned int data)
+{
+	__raw_writel(data, priv->reg + offs);
+}
+
+static inline unsigned int mips_ejtag_fdc_read(struct mips_ejtag_fdc_tty *priv,
+					       unsigned int offs)
+{
+	return __raw_readl(priv->reg + offs);
+}
+
+/* Encoding of byte stream in FDC words */
+
+/**
+ * struct fdc_word - FDC word encoding some number of bytes of data.
+ * @word:		Raw FDC word.
+ * @bytes:		Number of bytes encoded by @word.
+ */
+struct fdc_word {
+	u32		word;
+	unsigned int	bytes;
+};
+
+/*
+ * This is a compact encoding which allows every 1 byte, 2 byte, and 3 byte
+ * sequence to be encoded in a single word, while allowing the majority of 4
+ * byte sequences (including all ASCII and common binary data) to be encoded in
+ * a single word too.
+ *    _______________________ _____________
+ *   |       FDC Word        |             |
+ *   |31-24|23-16|15-8 | 7-0 |    Bytes    |
+ *   |_____|_____|_____|_____|_____________|
+ *   |     |     |     |     |             |
+ *   |0x80 |0x80 |0x80 |  WW | WW          |
+ *   |0x81 |0x81 |  XX |  WW | WW XX       |
+ *   |0x82 |  YY |  XX |  WW | WW XX YY    |
+ *   |  ZZ |  YY |  XX |  WW | WW XX YY ZZ |
+ *   |_____|_____|_____|_____|_____________|
+ *
+ * Note that the 4-byte encoding can only be used where none of the other 3
+ * encodings match, otherwise it must fall back to the 3 byte encoding.
+ */
+
+/* ranges >= 1 && sizes[0] >= 1 */
+static struct fdc_word mips_ejtag_fdc_encode(const char **ptrs,
+					     unsigned int *sizes,
+					     unsigned int ranges)
+{
+	struct fdc_word word = { 0, 0 };
+	const char **ptrs_end = ptrs + ranges;
+
+	for (; ptrs < ptrs_end; ++ptrs) {
+		const char *ptr = *(ptrs++);
+		const char *end = ptr + *(sizes++);
+
+		for (; ptr < end; ++ptr) {
+			word.word |= (u8)*ptr << (8*word.bytes);
+			++word.bytes;
+			if (word.bytes == 4)
+				goto done;
+		}
+	}
+done:
+	/* Choose the appropriate encoding */
+	switch (word.bytes) {
+	case 4:
+		/* 4 byte encoding, but don't match the 1-3 byte encodings */
+		if ((word.word >> 8) != 0x808080 &&
+		    (word.word >> 16) != 0x8181 &&
+		    (word.word >> 24) != 0x82)
+			break;
+		/* Fall back to a 3 byte encoding */
+		word.bytes = 3;
+		word.word &= 0x00ffffff;
+		fallthrough;
+	case 3:
+		/* 3 byte encoding */
+		word.word |= 0x82000000;
+		break;
+	case 2:
+		/* 2 byte encoding */
+		word.word |= 0x81810000;
+		break;
+	case 1:
+		/* 1 byte encoding */
+		word.word |= 0x80808000;
+		break;
+	}
+	return word;
+}
+
+static unsigned int mips_ejtag_fdc_decode(u32 word, char *buf)
+{
+	buf[0] = (u8)word;
+	word >>= 8;
+	if (word == 0x808080)
+		return 1;
+	buf[1] = (u8)word;
+	word >>= 8;
+	if (word == 0x8181)
+		return 2;
+	buf[2] = (u8)word;
+	word >>= 8;
+	if (word == 0x82)
+		return 3;
+	buf[3] = (u8)word;
+	return 4;
+}
+
+/* Console operations */
+
+/**
+ * struct mips_ejtag_fdc_console - Wrapper struct for FDC consoles.
+ * @cons:		Console object.
+ * @tty_drv:		TTY driver associated with this console.
+ * @lock:		Lock to protect concurrent access to other fields.
+ *			This is raw because it may be used very early.
+ * @initialised:	Whether the console is initialised.
+ * @regs:		Registers base address for each CPU.
+ */
+struct mips_ejtag_fdc_console {
+	struct console		 cons;
+	struct tty_driver	*tty_drv;
+	raw_spinlock_t		 lock;
+	bool			 initialised;
+	void __iomem		*regs[NR_CPUS];
+};
+
+/* Low level console write shared by early console and normal console */
+static void mips_ejtag_fdc_console_write(struct console *c, const char *s,
+					 unsigned int count)
+{
+	struct mips_ejtag_fdc_console *cons =
+		container_of(c, struct mips_ejtag_fdc_console, cons);
+	void __iomem *regs;
+	struct fdc_word word;
+	unsigned long flags;
+	unsigned int i, buf_len, cpu;
+	bool done_cr = false;
+	char buf[4];
+	const char *buf_ptr = buf;
+	/* Number of bytes of input data encoded up to each byte in buf */
+	u8 inc[4];
+
+	local_irq_save(flags);
+	cpu = smp_processor_id();
+	regs = cons->regs[cpu];
+	/* First console output on this CPU? */
+	if (!regs) {
+		regs = mips_cdmm_early_probe(0xfd);
+		cons->regs[cpu] = regs;
+	}
+	/* Already tried and failed to find FDC on this CPU? */
+	if (IS_ERR(regs))
+		goto out;
+	while (count) {
+		/*
+		 * Copy the next few characters to a buffer so we can inject
+		 * carriage returns before newlines.
+		 */
+		for (buf_len = 0, i = 0; buf_len < 4 && i < count; ++buf_len) {
+			if (s[i] == '\n' && !done_cr) {
+				buf[buf_len] = '\r';
+				done_cr = true;
+			} else {
+				buf[buf_len] = s[i];
+				done_cr = false;
+				++i;
+			}
+			inc[buf_len] = i;
+		}
+		word = mips_ejtag_fdc_encode(&buf_ptr, &buf_len, 1);
+		count -= inc[word.bytes - 1];
+		s += inc[word.bytes - 1];
+
+		/* Busy wait until there's space in fifo */
+		while (__raw_readl(regs + REG_FDSTAT) & REG_FDSTAT_TXF)
+			;
+		__raw_writel(word.word, regs + REG_FDTX(c->index));
+	}
+out:
+	local_irq_restore(flags);
+}
+
+static struct tty_driver *mips_ejtag_fdc_console_device(struct console *c,
+							int *index)
+{
+	struct mips_ejtag_fdc_console *cons =
+		container_of(c, struct mips_ejtag_fdc_console, cons);
+
+	*index = c->index;
+	return cons->tty_drv;
+}
+
+/* Initialise an FDC console (early or normal */
+static int __init mips_ejtag_fdc_console_init(struct mips_ejtag_fdc_console *c)
+{
+	void __iomem *regs;
+	unsigned long flags;
+	int ret = 0;
+
+	raw_spin_lock_irqsave(&c->lock, flags);
+	/* Don't init twice */
+	if (c->initialised)
+		goto out;
+	/* Look for the FDC device */
+	regs = mips_cdmm_early_probe(0xfd);
+	if (IS_ERR(regs)) {
+		ret = PTR_ERR(regs);
+		goto out;
+	}
+
+	c->initialised = true;
+	c->regs[smp_processor_id()] = regs;
+	register_console(&c->cons);
+out:
+	raw_spin_unlock_irqrestore(&c->lock, flags);
+	return ret;
+}
+
+static struct mips_ejtag_fdc_console mips_ejtag_fdc_con = {
+	.cons	= {
+		.name	= "fdc",
+		.write	= mips_ejtag_fdc_console_write,
+		.device	= mips_ejtag_fdc_console_device,
+		.flags	= CON_PRINTBUFFER,
+		.index	= -1,
+	},
+	.lock	= __RAW_SPIN_LOCK_UNLOCKED(mips_ejtag_fdc_con.lock),
+};
+
+/* TTY RX/TX operations */
+
+/**
+ * mips_ejtag_fdc_put_chan() - Write out a block of channel data.
+ * @priv:	Pointer to driver private data.
+ * @chan:	Channel number.
+ *
+ * Write a single block of data out to the debug adapter. If the circular buffer
+ * is wrapped then only the first block is written.
+ *
+ * Returns:	The number of bytes that were written.
+ */
+static unsigned int mips_ejtag_fdc_put_chan(struct mips_ejtag_fdc_tty *priv,
+					    unsigned int chan)
+{
+	struct mips_ejtag_fdc_tty_port *dport;
+	struct tty_struct *tty;
+	const char *ptrs[2];
+	unsigned int sizes[2] = { 0 };
+	struct fdc_word word = { .bytes = 0 };
+	unsigned long flags;
+
+	dport = &priv->ports[chan];
+	spin_lock(&dport->xmit_lock);
+	if (dport->xmit_cnt) {
+		ptrs[0] = dport->port.xmit_buf + dport->xmit_tail;
+		sizes[0] = min_t(unsigned int,
+				 priv->xmit_size - dport->xmit_tail,
+				 dport->xmit_cnt);
+		ptrs[1] = dport->port.xmit_buf;
+		sizes[1] = dport->xmit_cnt - sizes[0];
+		word = mips_ejtag_fdc_encode(ptrs, sizes, 1 + !!sizes[1]);
+
+		dev_dbg(priv->dev, "%s%u: out %08x: \"%*pE%*pE\"\n",
+			priv->driver_name, chan, word.word,
+			min_t(int, word.bytes, sizes[0]), ptrs[0],
+			max_t(int, 0, word.bytes - sizes[0]), ptrs[1]);
+
+		local_irq_save(flags);
+		/* Maybe we raced with the console and TX FIFO is full */
+		if (mips_ejtag_fdc_read(priv, REG_FDSTAT) & REG_FDSTAT_TXF)
+			word.bytes = 0;
+		else
+			mips_ejtag_fdc_write(priv, REG_FDTX(chan), word.word);
+		local_irq_restore(flags);
+
+		dport->xmit_cnt -= word.bytes;
+		if (!dport->xmit_cnt) {
+			/* Reset pointers to avoid wraps */
+			dport->xmit_head = 0;
+			dport->xmit_tail = 0;
+			complete(&dport->xmit_empty);
+		} else {
+			dport->xmit_tail += word.bytes;
+			if (dport->xmit_tail >= priv->xmit_size)
+				dport->xmit_tail -= priv->xmit_size;
+		}
+		atomic_sub(word.bytes, &priv->xmit_total);
+	}
+	spin_unlock(&dport->xmit_lock);
+
+	/* If we've made more data available, wake up tty */
+	if (sizes[0] && word.bytes) {
+		tty = tty_port_tty_get(&dport->port);
+		if (tty) {
+			tty_wakeup(tty);
+			tty_kref_put(tty);
+		}
+	}
+
+	return word.bytes;
+}
+
+/**
+ * mips_ejtag_fdc_put() - Kernel thread to write out channel data to FDC.
+ * @arg:	Driver pointer.
+ *
+ * This kernel thread runs while @priv->xmit_total != 0, and round robins the
+ * channels writing out blocks of buffered data to the FDC TX FIFO.
+ */
+static int mips_ejtag_fdc_put(void *arg)
+{
+	struct mips_ejtag_fdc_tty *priv = arg;
+	struct mips_ejtag_fdc_tty_port *dport;
+	unsigned int ret;
+	u32 cfg;
+
+	__set_current_state(TASK_RUNNING);
+	while (!kthread_should_stop()) {
+		/* Wait for data to actually write */
+		wait_event_interruptible(priv->waitqueue,
+					 atomic_read(&priv->xmit_total) ||
+					 kthread_should_stop());
+		if (kthread_should_stop())
+			break;
+
+		/* Wait for TX FIFO space to write data */
+		raw_spin_lock_irq(&priv->lock);
+		if (mips_ejtag_fdc_read(priv, REG_FDSTAT) & REG_FDSTAT_TXF) {
+			priv->xmit_full = true;
+			if (priv->irq >= 0) {
+				/* Enable TX interrupt */
+				cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+				cfg &= ~REG_FDCFG_TXINTTHRES;
+				cfg |= REG_FDCFG_TXINTTHRES_NOTFULL;
+				mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+			}
+		}
+		raw_spin_unlock_irq(&priv->lock);
+		wait_event_interruptible(priv->waitqueue,
+					 !(mips_ejtag_fdc_read(priv, REG_FDSTAT)
+					   & REG_FDSTAT_TXF) ||
+					 kthread_should_stop());
+		if (kthread_should_stop())
+			break;
+
+		/* Find next channel with data to output */
+		for (;;) {
+			dport = &priv->ports[priv->xmit_next];
+			spin_lock(&dport->xmit_lock);
+			ret = dport->xmit_cnt;
+			spin_unlock(&dport->xmit_lock);
+			if (ret)
+				break;
+			/* Round robin */
+			++priv->xmit_next;
+			if (priv->xmit_next >= NUM_TTY_CHANNELS)
+				priv->xmit_next = 0;
+		}
+
+		/* Try writing data to the chosen channel */
+		ret = mips_ejtag_fdc_put_chan(priv, priv->xmit_next);
+
+		/*
+		 * If anything was output, move on to the next channel so as not
+		 * to starve other channels.
+		 */
+		if (ret) {
+			++priv->xmit_next;
+			if (priv->xmit_next >= NUM_TTY_CHANNELS)
+				priv->xmit_next = 0;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * mips_ejtag_fdc_handle() - Handle FDC events.
+ * @priv:	Pointer to driver private data.
+ *
+ * Handle FDC events, such as new incoming data which needs draining out of the
+ * RX FIFO and feeding into the appropriate TTY ports, and space becoming
+ * available in the TX FIFO which would allow more data to be written out.
+ */
+static void mips_ejtag_fdc_handle(struct mips_ejtag_fdc_tty *priv)
+{
+	struct mips_ejtag_fdc_tty_port *dport;
+	unsigned int stat, channel, data, cfg, i, flipped;
+	int len;
+	char buf[4];
+
+	for (;;) {
+		/* Find which channel the next FDC word is destined for */
+		stat = mips_ejtag_fdc_read(priv, REG_FDSTAT);
+		if (stat & REG_FDSTAT_RXE)
+			break;
+		channel = (stat & REG_FDSTAT_RXCHAN) >> REG_FDSTAT_RXCHAN_SHIFT;
+		dport = &priv->ports[channel];
+
+		/* Read out the FDC word, decode it, and pass to tty layer */
+		raw_spin_lock(&dport->rx_lock);
+		data = mips_ejtag_fdc_read(priv, REG_FDRX);
+
+		len = mips_ejtag_fdc_decode(data, buf);
+		dev_dbg(priv->dev, "%s%u: in  %08x: \"%*pE\"\n",
+			priv->driver_name, channel, data, len, buf);
+
+		flipped = 0;
+		for (i = 0; i < len; ++i) {
+#ifdef CONFIG_MAGIC_SYSRQ
+#ifdef CONFIG_MIPS_EJTAG_FDC_KGDB
+			/* Support just Ctrl+C with KGDB channel */
+			if (channel == CONFIG_MIPS_EJTAG_FDC_KGDB_CHAN) {
+				if (buf[i] == '\x03') { /* ^C */
+					handle_sysrq('g');
+					continue;
+				}
+			}
+#endif
+			/* Support Ctrl+O for console channel */
+			if (channel == mips_ejtag_fdc_con.cons.index) {
+				if (buf[i] == '\x0f') {	/* ^O */
+					priv->sysrq_pressed =
+						!priv->sysrq_pressed;
+					if (priv->sysrq_pressed)
+						continue;
+				} else if (priv->sysrq_pressed) {
+					handle_sysrq(buf[i]);
+					priv->sysrq_pressed = false;
+					continue;
+				}
+			}
+#endif /* CONFIG_MAGIC_SYSRQ */
+
+			/* Check the port isn't being shut down */
+			if (!dport->rx_buf)
+				continue;
+
+			flipped += tty_insert_flip_char(&dport->port, buf[i],
+							TTY_NORMAL);
+		}
+		if (flipped)
+			tty_flip_buffer_push(&dport->port);
+
+		raw_spin_unlock(&dport->rx_lock);
+	}
+
+	/* If TX FIFO no longer full we may be able to write more data */
+	raw_spin_lock(&priv->lock);
+	if (priv->xmit_full && !(stat & REG_FDSTAT_TXF)) {
+		priv->xmit_full = false;
+
+		/* Disable TX interrupt */
+		cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+		cfg &= ~REG_FDCFG_TXINTTHRES;
+		cfg |= REG_FDCFG_TXINTTHRES_DISABLED;
+		mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+
+		/* Wait the kthread so it can try writing more data */
+		wake_up_interruptible(&priv->waitqueue);
+	}
+	raw_spin_unlock(&priv->lock);
+}
+
+/**
+ * mips_ejtag_fdc_isr() - Interrupt handler.
+ * @irq:	IRQ number.
+ * @dev_id:	Pointer to driver private data.
+ *
+ * This is the interrupt handler, used when interrupts are enabled.
+ *
+ * It simply triggers the common FDC handler code.
+ *
+ * Returns:	IRQ_HANDLED if an FDC interrupt was pending.
+ *		IRQ_NONE otherwise.
+ */
+static irqreturn_t mips_ejtag_fdc_isr(int irq, void *dev_id)
+{
+	struct mips_ejtag_fdc_tty *priv = dev_id;
+
+	/*
+	 * We're not using proper per-cpu IRQs, so we must be careful not to
+	 * handle IRQs on CPUs we're not interested in.
+	 *
+	 * Ideally proper per-cpu IRQ handlers could be used, but that doesn't
+	 * fit well with the whole sharing of the main CPU IRQ lines. When we
+	 * have something with a GIC that routes the FDC IRQs (i.e. no sharing
+	 * between handlers) then support could be added more easily.
+	 */
+	if (smp_processor_id() != priv->cpu)
+		return IRQ_NONE;
+
+	/* If no FDC interrupt pending, it wasn't for us */
+	if (!(read_c0_cause() & CAUSEF_FDCI))
+		return IRQ_NONE;
+
+	mips_ejtag_fdc_handle(priv);
+	return IRQ_HANDLED;
+}
+
+/**
+ * mips_ejtag_fdc_tty_timer() - Poll FDC for incoming data.
+ * @opaque:	Pointer to driver private data.
+ *
+ * This is the timer handler for when interrupts are disabled and polling the
+ * FDC state is required.
+ *
+ * It simply triggers the common FDC handler code and arranges for further
+ * polling.
+ */
+static void mips_ejtag_fdc_tty_timer(struct timer_list *t)
+{
+	struct mips_ejtag_fdc_tty *priv = from_timer(priv, t, poll_timer);
+
+	mips_ejtag_fdc_handle(priv);
+	if (!priv->removing)
+		mod_timer(&priv->poll_timer, jiffies + FDC_TTY_POLL);
+}
+
+/* TTY Port operations */
+
+static int mips_ejtag_fdc_tty_port_activate(struct tty_port *port,
+					    struct tty_struct *tty)
+{
+	struct mips_ejtag_fdc_tty_port *dport =
+		container_of(port, struct mips_ejtag_fdc_tty_port, port);
+	void *rx_buf;
+
+	/* Allocate the buffer we use for writing data */
+	if (tty_port_alloc_xmit_buf(port) < 0)
+		goto err;
+
+	/* Allocate the buffer we use for reading data */
+	rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
+	if (!rx_buf)
+		goto err_free_xmit;
+
+	raw_spin_lock_irq(&dport->rx_lock);
+	dport->rx_buf = rx_buf;
+	raw_spin_unlock_irq(&dport->rx_lock);
+
+	return 0;
+err_free_xmit:
+	tty_port_free_xmit_buf(port);
+err:
+	return -ENOMEM;
+}
+
+static void mips_ejtag_fdc_tty_port_shutdown(struct tty_port *port)
+{
+	struct mips_ejtag_fdc_tty_port *dport =
+		container_of(port, struct mips_ejtag_fdc_tty_port, port);
+	struct mips_ejtag_fdc_tty *priv = dport->driver;
+	void *rx_buf;
+	unsigned int count;
+
+	spin_lock(&dport->xmit_lock);
+	count = dport->xmit_cnt;
+	spin_unlock(&dport->xmit_lock);
+	if (count) {
+		/*
+		 * There's still data to write out, so wake and wait for the
+		 * writer thread to drain the buffer.
+		 */
+		wake_up_interruptible(&priv->waitqueue);
+		wait_for_completion(&dport->xmit_empty);
+	}
+
+	/* Null the read buffer (timer could still be running!) */
+	raw_spin_lock_irq(&dport->rx_lock);
+	rx_buf = dport->rx_buf;
+	dport->rx_buf = NULL;
+	raw_spin_unlock_irq(&dport->rx_lock);
+	/* Free the read buffer */
+	kfree(rx_buf);
+
+	/* Free the write buffer */
+	tty_port_free_xmit_buf(port);
+}
+
+static const struct tty_port_operations mips_ejtag_fdc_tty_port_ops = {
+	.activate	= mips_ejtag_fdc_tty_port_activate,
+	.shutdown	= mips_ejtag_fdc_tty_port_shutdown,
+};
+
+/* TTY operations */
+
+static int mips_ejtag_fdc_tty_install(struct tty_driver *driver,
+				      struct tty_struct *tty)
+{
+	struct mips_ejtag_fdc_tty *priv = driver->driver_state;
+
+	tty->driver_data = &priv->ports[tty->index];
+	return tty_port_install(&priv->ports[tty->index].port, driver, tty);
+}
+
+static int mips_ejtag_fdc_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_open(tty->port, tty, filp);
+}
+
+static void mips_ejtag_fdc_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_close(tty->port, tty, filp);
+}
+
+static void mips_ejtag_fdc_tty_hangup(struct tty_struct *tty)
+{
+	struct mips_ejtag_fdc_tty_port *dport = tty->driver_data;
+	struct mips_ejtag_fdc_tty *priv = dport->driver;
+
+	/* Drop any data in the xmit buffer */
+	spin_lock(&dport->xmit_lock);
+	if (dport->xmit_cnt) {
+		atomic_sub(dport->xmit_cnt, &priv->xmit_total);
+		dport->xmit_cnt = 0;
+		dport->xmit_head = 0;
+		dport->xmit_tail = 0;
+		complete(&dport->xmit_empty);
+	}
+	spin_unlock(&dport->xmit_lock);
+
+	tty_port_hangup(tty->port);
+}
+
+static ssize_t mips_ejtag_fdc_tty_write(struct tty_struct *tty, const u8 *buf,
+					size_t total)
+{
+	int count, block;
+	struct mips_ejtag_fdc_tty_port *dport = tty->driver_data;
+	struct mips_ejtag_fdc_tty *priv = dport->driver;
+
+	/*
+	 * Write to output buffer.
+	 *
+	 * The reason that we asynchronously write the buffer is because if we
+	 * were to write the buffer synchronously then because the channels are
+	 * per-CPU the buffer would be written to the channel of whatever CPU
+	 * we're running on.
+	 *
+	 * What we actually want to happen is have all input and output done on
+	 * one CPU.
+	 */
+	spin_lock(&dport->xmit_lock);
+	/* Work out how many bytes we can write to the xmit buffer */
+	total = min_t(size_t, total, priv->xmit_size - dport->xmit_cnt);
+	atomic_add(total, &priv->xmit_total);
+	dport->xmit_cnt += total;
+	/* Write the actual bytes (may need splitting if it wraps) */
+	for (count = total; count; count -= block) {
+		block = min(count, (int)(priv->xmit_size - dport->xmit_head));
+		memcpy(dport->port.xmit_buf + dport->xmit_head, buf, block);
+		dport->xmit_head += block;
+		if (dport->xmit_head >= priv->xmit_size)
+			dport->xmit_head -= priv->xmit_size;
+		buf += block;
+	}
+	count = dport->xmit_cnt;
+	/* Xmit buffer no longer empty? */
+	if (count)
+		reinit_completion(&dport->xmit_empty);
+	spin_unlock(&dport->xmit_lock);
+
+	/* Wake up the kthread */
+	if (total)
+		wake_up_interruptible(&priv->waitqueue);
+	return total;
+}
+
+static unsigned int mips_ejtag_fdc_tty_write_room(struct tty_struct *tty)
+{
+	struct mips_ejtag_fdc_tty_port *dport = tty->driver_data;
+	struct mips_ejtag_fdc_tty *priv = dport->driver;
+	unsigned int room;
+
+	/* Report the space in the xmit buffer */
+	spin_lock(&dport->xmit_lock);
+	room = priv->xmit_size - dport->xmit_cnt;
+	spin_unlock(&dport->xmit_lock);
+
+	return room;
+}
+
+static unsigned int mips_ejtag_fdc_tty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct mips_ejtag_fdc_tty_port *dport = tty->driver_data;
+	unsigned int chars;
+
+	/* Report the number of bytes in the xmit buffer */
+	spin_lock(&dport->xmit_lock);
+	chars = dport->xmit_cnt;
+	spin_unlock(&dport->xmit_lock);
+
+	return chars;
+}
+
+static const struct tty_operations mips_ejtag_fdc_tty_ops = {
+	.install		= mips_ejtag_fdc_tty_install,
+	.open			= mips_ejtag_fdc_tty_open,
+	.close			= mips_ejtag_fdc_tty_close,
+	.hangup			= mips_ejtag_fdc_tty_hangup,
+	.write			= mips_ejtag_fdc_tty_write,
+	.write_room		= mips_ejtag_fdc_tty_write_room,
+	.chars_in_buffer	= mips_ejtag_fdc_tty_chars_in_buffer,
+};
+
+int __weak get_c0_fdc_int(void)
+{
+	return -1;
+}
+
+static int mips_ejtag_fdc_tty_probe(struct mips_cdmm_device *dev)
+{
+	int ret, nport;
+	struct mips_ejtag_fdc_tty_port *dport;
+	struct mips_ejtag_fdc_tty *priv;
+	struct tty_driver *driver;
+	unsigned int cfg, tx_fifo;
+
+	priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->cpu = dev->cpu;
+	priv->dev = &dev->dev;
+	mips_cdmm_set_drvdata(dev, priv);
+	atomic_set(&priv->xmit_total, 0);
+	raw_spin_lock_init(&priv->lock);
+
+	priv->reg = devm_ioremap(priv->dev, dev->res.start,
+					 resource_size(&dev->res));
+	if (!priv->reg) {
+		dev_err(priv->dev, "ioremap failed for resource %pR\n",
+			&dev->res);
+		return -ENOMEM;
+	}
+
+	cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+	tx_fifo = (cfg & REG_FDCFG_TXFIFOSIZE) >> REG_FDCFG_TXFIFOSIZE_SHIFT;
+	/* Disable interrupts */
+	cfg &= ~(REG_FDCFG_TXINTTHRES | REG_FDCFG_RXINTTHRES);
+	cfg |= REG_FDCFG_TXINTTHRES_DISABLED;
+	cfg |= REG_FDCFG_RXINTTHRES_DISABLED;
+	mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+
+	/* Make each port's xmit FIFO big enough to fill FDC TX FIFO */
+	priv->xmit_size = min(tx_fifo * 4, (unsigned int)UART_XMIT_SIZE);
+
+	driver = tty_alloc_driver(NUM_TTY_CHANNELS, TTY_DRIVER_REAL_RAW);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
+	priv->driver = driver;
+
+	driver->driver_name = "ejtag_fdc";
+	snprintf(priv->fdc_name, sizeof(priv->fdc_name), "ttyFDC%u", dev->cpu);
+	snprintf(priv->driver_name, sizeof(priv->driver_name), "%sc",
+		 priv->fdc_name);
+	driver->name = priv->driver_name;
+	driver->major = 0; /* Auto-allocate */
+	driver->minor_start = 0;
+	driver->type = TTY_DRIVER_TYPE_SERIAL;
+	driver->subtype = SERIAL_TYPE_NORMAL;
+	driver->init_termios = tty_std_termios;
+	driver->init_termios.c_cflag |= CLOCAL;
+	driver->driver_state = priv;
+
+	tty_set_operations(driver, &mips_ejtag_fdc_tty_ops);
+	for (nport = 0; nport < NUM_TTY_CHANNELS; nport++) {
+		dport = &priv->ports[nport];
+		dport->driver = priv;
+		tty_port_init(&dport->port);
+		dport->port.ops = &mips_ejtag_fdc_tty_port_ops;
+		raw_spin_lock_init(&dport->rx_lock);
+		spin_lock_init(&dport->xmit_lock);
+		/* The xmit buffer starts empty, i.e. completely written */
+		init_completion(&dport->xmit_empty);
+		complete(&dport->xmit_empty);
+	}
+
+	/* Set up the console */
+	mips_ejtag_fdc_con.regs[dev->cpu] = priv->reg;
+	if (dev->cpu == 0)
+		mips_ejtag_fdc_con.tty_drv = driver;
+
+	init_waitqueue_head(&priv->waitqueue);
+	/*
+	 * Bind the writer thread to the right CPU so it can't migrate.
+	 * The channels are per-CPU and we want all channel I/O to be on a
+	 * single predictable CPU.
+	 */
+	priv->thread = kthread_run_on_cpu(mips_ejtag_fdc_put, priv,
+					  dev->cpu, "ttyFDC/%u");
+	if (IS_ERR(priv->thread)) {
+		ret = PTR_ERR(priv->thread);
+		dev_err(priv->dev, "Couldn't create kthread (%d)\n", ret);
+		goto err_destroy_ports;
+	}
+
+	/* Look for an FDC IRQ */
+	priv->irq = get_c0_fdc_int();
+
+	/* Try requesting the IRQ */
+	if (priv->irq >= 0) {
+		/*
+		 * IRQF_SHARED, IRQF_COND_SUSPEND: The FDC IRQ may be shared with
+		 * other local interrupts such as the timer which sets
+		 * IRQF_TIMER (including IRQF_NO_SUSPEND).
+		 *
+		 * IRQF_NO_THREAD: The FDC IRQ isn't individually maskable so it
+		 * cannot be deferred and handled by a thread on RT kernels. For
+		 * this reason any spinlocks used from the ISR are raw.
+		 */
+		ret = devm_request_irq(priv->dev, priv->irq, mips_ejtag_fdc_isr,
+				       IRQF_PERCPU | IRQF_SHARED |
+				       IRQF_NO_THREAD | IRQF_COND_SUSPEND,
+				       priv->fdc_name, priv);
+		if (ret)
+			priv->irq = -1;
+	}
+	if (priv->irq >= 0) {
+		/* IRQ is usable, enable RX interrupt */
+		raw_spin_lock_irq(&priv->lock);
+		cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+		cfg &= ~REG_FDCFG_RXINTTHRES;
+		cfg |= REG_FDCFG_RXINTTHRES_NOTEMPTY;
+		mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+		raw_spin_unlock_irq(&priv->lock);
+	} else {
+		/* If we didn't get an usable IRQ, poll instead */
+		timer_setup(&priv->poll_timer, mips_ejtag_fdc_tty_timer,
+			    TIMER_PINNED);
+		priv->poll_timer.expires = jiffies + FDC_TTY_POLL;
+		/*
+		 * Always attach the timer to the right CPU. The channels are
+		 * per-CPU so all polling should be from a single CPU.
+		 */
+		add_timer_on(&priv->poll_timer, dev->cpu);
+
+		dev_info(priv->dev, "No usable IRQ, polling enabled\n");
+	}
+
+	ret = tty_register_driver(driver);
+	if (ret < 0) {
+		dev_err(priv->dev, "Couldn't install tty driver (%d)\n", ret);
+		goto err_stop_irq;
+	}
+
+	return 0;
+
+err_stop_irq:
+	if (priv->irq >= 0) {
+		raw_spin_lock_irq(&priv->lock);
+		cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+		/* Disable interrupts */
+		cfg &= ~(REG_FDCFG_TXINTTHRES | REG_FDCFG_RXINTTHRES);
+		cfg |= REG_FDCFG_TXINTTHRES_DISABLED;
+		cfg |= REG_FDCFG_RXINTTHRES_DISABLED;
+		mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+		raw_spin_unlock_irq(&priv->lock);
+	} else {
+		priv->removing = true;
+		del_timer_sync(&priv->poll_timer);
+	}
+	kthread_stop(priv->thread);
+err_destroy_ports:
+	if (dev->cpu == 0)
+		mips_ejtag_fdc_con.tty_drv = NULL;
+	for (nport = 0; nport < NUM_TTY_CHANNELS; nport++) {
+		dport = &priv->ports[nport];
+		tty_port_destroy(&dport->port);
+	}
+	tty_driver_kref_put(priv->driver);
+	return ret;
+}
+
+static int mips_ejtag_fdc_tty_cpu_down(struct mips_cdmm_device *dev)
+{
+	struct mips_ejtag_fdc_tty *priv = mips_cdmm_get_drvdata(dev);
+	unsigned int cfg;
+
+	if (priv->irq >= 0) {
+		raw_spin_lock_irq(&priv->lock);
+		cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+		/* Disable interrupts */
+		cfg &= ~(REG_FDCFG_TXINTTHRES | REG_FDCFG_RXINTTHRES);
+		cfg |= REG_FDCFG_TXINTTHRES_DISABLED;
+		cfg |= REG_FDCFG_RXINTTHRES_DISABLED;
+		mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+		raw_spin_unlock_irq(&priv->lock);
+	} else {
+		priv->removing = true;
+		del_timer_sync(&priv->poll_timer);
+	}
+	kthread_stop(priv->thread);
+
+	return 0;
+}
+
+static int mips_ejtag_fdc_tty_cpu_up(struct mips_cdmm_device *dev)
+{
+	struct mips_ejtag_fdc_tty *priv = mips_cdmm_get_drvdata(dev);
+	unsigned int cfg;
+	int ret = 0;
+
+	if (priv->irq >= 0) {
+		/*
+		 * IRQ is usable, enable RX interrupt
+		 * This must be before kthread is restarted, as kthread may
+		 * enable TX interrupt.
+		 */
+		raw_spin_lock_irq(&priv->lock);
+		cfg = mips_ejtag_fdc_read(priv, REG_FDCFG);
+		cfg &= ~(REG_FDCFG_TXINTTHRES | REG_FDCFG_RXINTTHRES);
+		cfg |= REG_FDCFG_TXINTTHRES_DISABLED;
+		cfg |= REG_FDCFG_RXINTTHRES_NOTEMPTY;
+		mips_ejtag_fdc_write(priv, REG_FDCFG, cfg);
+		raw_spin_unlock_irq(&priv->lock);
+	} else {
+		/* Restart poll timer */
+		priv->removing = false;
+		add_timer_on(&priv->poll_timer, dev->cpu);
+	}
+
+	/* Restart the kthread */
+	/* Bind it back to the right CPU and set it off */
+	priv->thread = kthread_run_on_cpu(mips_ejtag_fdc_put, priv,
+					  dev->cpu, "ttyFDC/%u");
+	if (IS_ERR(priv->thread)) {
+		ret = PTR_ERR(priv->thread);
+		dev_err(priv->dev, "Couldn't re-create kthread (%d)\n", ret);
+		goto out;
+	}
+out:
+	return ret;
+}
+
+static const struct mips_cdmm_device_id mips_ejtag_fdc_tty_ids[] = {
+	{ .type = 0xfd },
+	{ }
+};
+
+static struct mips_cdmm_driver mips_ejtag_fdc_tty_driver = {
+	.drv		= {
+		.name	= "mips_ejtag_fdc",
+	},
+	.probe		= mips_ejtag_fdc_tty_probe,
+	.cpu_down	= mips_ejtag_fdc_tty_cpu_down,
+	.cpu_up		= mips_ejtag_fdc_tty_cpu_up,
+	.id_table	= mips_ejtag_fdc_tty_ids,
+};
+builtin_mips_cdmm_driver(mips_ejtag_fdc_tty_driver);
+
+static int __init mips_ejtag_fdc_init_console(void)
+{
+	return mips_ejtag_fdc_console_init(&mips_ejtag_fdc_con);
+}
+console_initcall(mips_ejtag_fdc_init_console);
+
+#ifdef CONFIG_MIPS_EJTAG_FDC_EARLYCON
+static struct mips_ejtag_fdc_console mips_ejtag_fdc_earlycon = {
+	.cons	= {
+		.name	= "early_fdc",
+		.write	= mips_ejtag_fdc_console_write,
+		.flags	= CON_PRINTBUFFER | CON_BOOT,
+		.index	= CONSOLE_CHANNEL,
+	},
+	.lock	= __RAW_SPIN_LOCK_UNLOCKED(mips_ejtag_fdc_earlycon.lock),
+};
+
+int __init setup_early_fdc_console(void)
+{
+	return mips_ejtag_fdc_console_init(&mips_ejtag_fdc_earlycon);
+}
+#endif
+
+#ifdef CONFIG_MIPS_EJTAG_FDC_KGDB
+
+/* read buffer to allow decompaction */
+static unsigned int kgdbfdc_rbuflen;
+static unsigned int kgdbfdc_rpos;
+static char kgdbfdc_rbuf[4];
+
+/* write buffer to allow compaction */
+static unsigned int kgdbfdc_wbuflen;
+static char kgdbfdc_wbuf[4];
+
+static void __iomem *kgdbfdc_setup(void)
+{
+	void __iomem *regs;
+	unsigned int cpu;
+
+	/* Find address, piggy backing off console percpu regs */
+	cpu = smp_processor_id();
+	regs = mips_ejtag_fdc_con.regs[cpu];
+	/* First console output on this CPU? */
+	if (!regs) {
+		regs = mips_cdmm_early_probe(0xfd);
+		mips_ejtag_fdc_con.regs[cpu] = regs;
+	}
+	/* Already tried and failed to find FDC on this CPU? */
+	if (IS_ERR(regs))
+		return regs;
+
+	return regs;
+}
+
+/* read a character from the read buffer, filling from FDC RX FIFO */
+static int kgdbfdc_read_char(void)
+{
+	unsigned int stat, channel, data;
+	void __iomem *regs;
+
+	/* No more data, try and read another FDC word from RX FIFO */
+	if (kgdbfdc_rpos >= kgdbfdc_rbuflen) {
+		kgdbfdc_rpos = 0;
+		kgdbfdc_rbuflen = 0;
+
+		regs = kgdbfdc_setup();
+		if (IS_ERR(regs))
+			return NO_POLL_CHAR;
+
+		/* Read next word from KGDB channel */
+		do {
+			stat = __raw_readl(regs + REG_FDSTAT);
+
+			/* No data waiting? */
+			if (stat & REG_FDSTAT_RXE)
+				return NO_POLL_CHAR;
+
+			/* Read next word */
+			channel = (stat & REG_FDSTAT_RXCHAN) >>
+					REG_FDSTAT_RXCHAN_SHIFT;
+			data = __raw_readl(regs + REG_FDRX);
+		} while (channel != CONFIG_MIPS_EJTAG_FDC_KGDB_CHAN);
+
+		/* Decode into rbuf */
+		kgdbfdc_rbuflen = mips_ejtag_fdc_decode(data, kgdbfdc_rbuf);
+	}
+	pr_devel("kgdbfdc r %c\n", kgdbfdc_rbuf[kgdbfdc_rpos]);
+	return kgdbfdc_rbuf[kgdbfdc_rpos++];
+}
+
+/* push an FDC word from write buffer to TX FIFO */
+static void kgdbfdc_push_one(void)
+{
+	const char *bufs[1] = { kgdbfdc_wbuf };
+	struct fdc_word word;
+	void __iomem *regs;
+	unsigned int i;
+
+	/* Construct a word from any data in buffer */
+	word = mips_ejtag_fdc_encode(bufs, &kgdbfdc_wbuflen, 1);
+	/* Relocate any remaining data to beginning of buffer */
+	kgdbfdc_wbuflen -= word.bytes;
+	for (i = 0; i < kgdbfdc_wbuflen; ++i)
+		kgdbfdc_wbuf[i] = kgdbfdc_wbuf[i + word.bytes];
+
+	regs = kgdbfdc_setup();
+	if (IS_ERR(regs))
+		return;
+
+	/* Busy wait until there's space in fifo */
+	while (__raw_readl(regs + REG_FDSTAT) & REG_FDSTAT_TXF)
+		;
+	__raw_writel(word.word,
+		     regs + REG_FDTX(CONFIG_MIPS_EJTAG_FDC_KGDB_CHAN));
+}
+
+/* flush the whole write buffer to the TX FIFO */
+static void kgdbfdc_flush(void)
+{
+	while (kgdbfdc_wbuflen)
+		kgdbfdc_push_one();
+}
+
+/* write a character into the write buffer, writing out if full */
+static void kgdbfdc_write_char(u8 chr)
+{
+	pr_devel("kgdbfdc w %c\n", chr);
+	kgdbfdc_wbuf[kgdbfdc_wbuflen++] = chr;
+	if (kgdbfdc_wbuflen >= sizeof(kgdbfdc_wbuf))
+		kgdbfdc_push_one();
+}
+
+static struct kgdb_io kgdbfdc_io_ops = {
+	.name		= "kgdbfdc",
+	.read_char	= kgdbfdc_read_char,
+	.write_char	= kgdbfdc_write_char,
+	.flush		= kgdbfdc_flush,
+};
+
+static int __init kgdbfdc_init(void)
+{
+	kgdb_register_io_module(&kgdbfdc_io_ops);
+	return 0;
+}
+early_initcall(kgdbfdc_init);
+#endif
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
new file mode 100644
index 000000000..bf3f87ba3
--- /dev/null
+++ b/drivers/tty/moxa.c
@@ -0,0 +1,2398 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*****************************************************************************/
+/*
+ *           moxa.c  -- MOXA Intellio family multiport serial driver.
+ *
+ *      Copyright (C) 1999-2000  Moxa Technologies (support@moxa.com).
+ *      Copyright (c) 2007 Jiri Slaby <jirislaby@gmail.com>
+ *
+ *      This code is loosely based on the Linux serial driver, written by
+ *      Linus Torvalds, Theodore T'so and others.
+ */
+
+/*
+ *    MOXA Intellio Series Driver
+ *      for             : LINUX
+ *      date            : 1999/1/7
+ *      version         : 5.1
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/firmware.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/serial.h>
+#include <linux/tty_driver.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/ratelimit.h>
+
+#include <asm/io.h>
+#include <linux/uaccess.h>
+
+#define	MOXA			0x400
+#define MOXA_GET_IQUEUE		(MOXA + 1)	/* get input buffered count */
+#define MOXA_GET_OQUEUE		(MOXA + 2)	/* get output buffered count */
+#define MOXA_GETDATACOUNT       (MOXA + 23)
+#define MOXA_GET_IOQUEUE	(MOXA + 27)
+#define MOXA_FLUSH_QUEUE	(MOXA + 28)
+#define MOXA_GETMSTATUS         (MOXA + 65)
+
+/*
+ *    System Configuration
+ */
+
+#define Magic_code	0x404
+
+/*
+ *    for C218 BIOS initialization
+ */
+#define C218_ConfBase	0x800
+#define C218_status	(C218_ConfBase + 0)	/* BIOS running status    */
+#define C218_diag	(C218_ConfBase + 2)	/* diagnostic status      */
+#define C218_key	(C218_ConfBase + 4)	/* WORD (0x218 for C218) */
+#define C218DLoad_len	(C218_ConfBase + 6)	/* WORD           */
+#define C218check_sum	(C218_ConfBase + 8)	/* BYTE           */
+#define C218chksum_ok	(C218_ConfBase + 0x0a)	/* BYTE (1:ok)            */
+#define C218_TestRx	(C218_ConfBase + 0x10)	/* 8 bytes for 8 ports    */
+#define C218_TestTx	(C218_ConfBase + 0x18)	/* 8 bytes for 8 ports    */
+#define C218_RXerr	(C218_ConfBase + 0x20)	/* 8 bytes for 8 ports    */
+#define C218_ErrFlag	(C218_ConfBase + 0x28)	/* 8 bytes for 8 ports    */
+
+#define C218_LoadBuf	0x0F00
+#define C218_KeyCode	0x218
+#define CP204J_KeyCode	0x204
+
+/*
+ *    for C320 BIOS initialization
+ */
+#define C320_ConfBase	0x800
+#define C320_LoadBuf	0x0f00
+#define STS_init	0x05	/* for C320_status        */
+
+#define C320_status	C320_ConfBase + 0	/* BIOS running status    */
+#define C320_diag	C320_ConfBase + 2	/* diagnostic status      */
+#define C320_key	C320_ConfBase + 4	/* WORD (0320H for C320) */
+#define C320DLoad_len	C320_ConfBase + 6	/* WORD           */
+#define C320check_sum	C320_ConfBase + 8	/* WORD           */
+#define C320chksum_ok	C320_ConfBase + 0x0a	/* WORD (1:ok)            */
+#define C320bapi_len	C320_ConfBase + 0x0c	/* WORD           */
+#define C320UART_no	C320_ConfBase + 0x0e	/* WORD           */
+
+#define C320_KeyCode	0x320
+
+#define FixPage_addr	0x0000	/* starting addr of static page  */
+#define DynPage_addr	0x2000	/* starting addr of dynamic page */
+#define C218_start	0x3000	/* starting addr of C218 BIOS prg */
+#define Control_reg	0x1ff0	/* select page and reset control */
+#define HW_reset	0x80
+
+/*
+ *    Function Codes
+ */
+#define FC_CardReset	0x80
+#define FC_ChannelReset 1	/* C320 firmware not supported */
+#define FC_EnableCH	2
+#define FC_DisableCH	3
+#define FC_SetParam	4
+#define FC_SetMode	5
+#define FC_SetRate	6
+#define FC_LineControl	7
+#define FC_LineStatus	8
+#define FC_XmitControl	9
+#define FC_FlushQueue	10
+#define FC_SendBreak	11
+#define FC_StopBreak	12
+#define FC_LoopbackON	13
+#define FC_LoopbackOFF	14
+#define FC_ClrIrqTable	15
+#define FC_SendXon	16
+#define FC_SetTermIrq	17	/* C320 firmware not supported */
+#define FC_SetCntIrq	18	/* C320 firmware not supported */
+#define FC_SetBreakIrq	19
+#define FC_SetLineIrq	20
+#define FC_SetFlowCtl	21
+#define FC_GenIrq	22
+#define FC_InCD180	23
+#define FC_OutCD180	24
+#define FC_InUARTreg	23
+#define FC_OutUARTreg	24
+#define FC_SetXonXoff	25
+#define FC_OutCD180CCR	26
+#define FC_ExtIQueue	27
+#define FC_ExtOQueue	28
+#define FC_ClrLineIrq	29
+#define FC_HWFlowCtl	30
+#define FC_GetClockRate 35
+#define FC_SetBaud	36
+#define FC_SetDataMode  41
+#define FC_GetCCSR      43
+#define FC_GetDataError 45
+#define FC_RxControl	50
+#define FC_ImmSend	51
+#define FC_SetXonState	52
+#define FC_SetXoffState	53
+#define FC_SetRxFIFOTrig 54
+#define FC_SetTxFIFOCnt 55
+#define FC_UnixRate	56
+#define FC_UnixResetTimer 57
+
+#define	RxFIFOTrig1	0
+#define	RxFIFOTrig4	1
+#define	RxFIFOTrig8	2
+#define	RxFIFOTrig14	3
+
+/*
+ *    Dual-Ported RAM
+ */
+#define DRAM_global	0
+#define INT_data	(DRAM_global + 0)
+#define Config_base	(DRAM_global + 0x108)
+
+#define IRQindex	(INT_data + 0)
+#define IRQpending	(INT_data + 4)
+#define IRQtable	(INT_data + 8)
+
+/*
+ *    Interrupt Status
+ */
+#define IntrRx		0x01	/* receiver data O.K.             */
+#define IntrTx		0x02	/* transmit buffer empty  */
+#define IntrFunc	0x04	/* function complete              */
+#define IntrBreak	0x08	/* received break         */
+#define IntrLine	0x10	/* line status change
+				   for transmitter                */
+#define IntrIntr	0x20	/* received INTR code             */
+#define IntrQuit	0x40	/* received QUIT code             */
+#define IntrEOF		0x80	/* received EOF code              */
+
+#define IntrRxTrigger	0x100	/* rx data count reach trigger value */
+#define IntrTxTrigger	0x200	/* tx data count below trigger value */
+
+#define Magic_no	(Config_base + 0)
+#define Card_model_no	(Config_base + 2)
+#define Total_ports	(Config_base + 4)
+#define Module_cnt	(Config_base + 8)
+#define Module_no	(Config_base + 10)
+#define Timer_10ms	(Config_base + 14)
+#define Disable_IRQ	(Config_base + 20)
+#define TMS320_PORT1	(Config_base + 22)
+#define TMS320_PORT2	(Config_base + 24)
+#define TMS320_CLOCK	(Config_base + 26)
+
+/*
+ *    DATA BUFFER in DRAM
+ */
+#define Extern_table	0x400	/* Base address of the external table
+				   (24 words *    64) total 3K bytes
+				   (24 words * 128) total 6K bytes */
+#define Extern_size	0x60	/* 96 bytes                       */
+#define RXrptr		0x00	/* read pointer for RX buffer     */
+#define RXwptr		0x02	/* write pointer for RX buffer    */
+#define TXrptr		0x04	/* read pointer for TX buffer     */
+#define TXwptr		0x06	/* write pointer for TX buffer    */
+#define HostStat	0x08	/* IRQ flag and general flag      */
+#define FlagStat	0x0A
+#define FlowControl	0x0C	/* B7 B6 B5 B4 B3 B2 B1 B0              */
+				/*  x  x  x  x  |  |  |  |            */
+				/*              |  |  |  + CTS flow   */
+				/*              |  |  +--- RTS flow   */
+				/*              |  +------ TX Xon/Xoff */
+				/*              +--------- RX Xon/Xoff */
+#define Break_cnt	0x0E	/* received break count   */
+#define CD180TXirq	0x10	/* if non-0: enable TX irq        */
+#define RX_mask		0x12
+#define TX_mask		0x14
+#define Ofs_rxb		0x16
+#define Ofs_txb		0x18
+#define Page_rxb	0x1A
+#define Page_txb	0x1C
+#define EndPage_rxb	0x1E
+#define EndPage_txb	0x20
+#define Data_error	0x22
+#define RxTrigger	0x28
+#define TxTrigger	0x2a
+
+#define rRXwptr		0x34
+#define Low_water	0x36
+
+#define FuncCode	0x40
+#define FuncArg		0x42
+#define FuncArg1	0x44
+
+#define C218rx_size	0x2000	/* 8K bytes */
+#define C218tx_size	0x8000	/* 32K bytes */
+
+#define C218rx_mask	(C218rx_size - 1)
+#define C218tx_mask	(C218tx_size - 1)
+
+#define C320p8rx_size	0x2000
+#define C320p8tx_size	0x8000
+#define C320p8rx_mask	(C320p8rx_size - 1)
+#define C320p8tx_mask	(C320p8tx_size - 1)
+
+#define C320p16rx_size	0x2000
+#define C320p16tx_size	0x4000
+#define C320p16rx_mask	(C320p16rx_size - 1)
+#define C320p16tx_mask	(C320p16tx_size - 1)
+
+#define C320p24rx_size	0x2000
+#define C320p24tx_size	0x2000
+#define C320p24rx_mask	(C320p24rx_size - 1)
+#define C320p24tx_mask	(C320p24tx_size - 1)
+
+#define C320p32rx_size	0x1000
+#define C320p32tx_size	0x1000
+#define C320p32rx_mask	(C320p32rx_size - 1)
+#define C320p32tx_mask	(C320p32tx_size - 1)
+
+#define Page_size	0x2000U
+#define Page_mask	(Page_size - 1)
+#define C218rx_spage	3
+#define C218tx_spage	4
+#define C218rx_pageno	1
+#define C218tx_pageno	4
+#define C218buf_pageno	5
+
+#define C320p8rx_spage	3
+#define C320p8tx_spage	4
+#define C320p8rx_pgno	1
+#define C320p8tx_pgno	4
+#define C320p8buf_pgno	5
+
+#define C320p16rx_spage 3
+#define C320p16tx_spage 4
+#define C320p16rx_pgno	1
+#define C320p16tx_pgno	2
+#define C320p16buf_pgno 3
+
+#define C320p24rx_spage 3
+#define C320p24tx_spage 4
+#define C320p24rx_pgno	1
+#define C320p24tx_pgno	1
+#define C320p24buf_pgno 2
+
+#define C320p32rx_spage 3
+#define C320p32tx_ofs	C320p32rx_size
+#define C320p32tx_spage 3
+#define C320p32buf_pgno 1
+
+/*
+ *    Host Status
+ */
+#define WakeupRx	0x01
+#define WakeupTx	0x02
+#define WakeupBreak	0x08
+#define WakeupLine	0x10
+#define WakeupIntr	0x20
+#define WakeupQuit	0x40
+#define WakeupEOF	0x80	/* used in VTIME control */
+#define WakeupRxTrigger	0x100
+#define WakeupTxTrigger	0x200
+/*
+ *    Flag status
+ */
+#define Rx_over		0x01
+#define Xoff_state	0x02
+#define Tx_flowOff	0x04
+#define Tx_enable	0x08
+#define CTS_state	0x10
+#define DSR_state	0x20
+#define DCD_state	0x80
+/*
+ *    FlowControl
+ */
+#define CTS_FlowCtl	1
+#define RTS_FlowCtl	2
+#define Tx_FlowCtl	4
+#define Rx_FlowCtl	8
+#define IXM_IXANY	0x10
+
+#define LowWater	128
+
+#define DTR_ON		1
+#define RTS_ON		2
+#define CTS_ON		1
+#define DSR_ON		2
+#define DCD_ON		8
+
+/* mode definition */
+#define	MX_CS8		0x03
+#define	MX_CS7		0x02
+#define	MX_CS6		0x01
+#define	MX_CS5		0x00
+
+#define	MX_STOP1	0x00
+#define	MX_STOP15	0x04
+#define	MX_STOP2	0x08
+
+#define	MX_PARNONE	0x00
+#define	MX_PAREVEN	0x40
+#define	MX_PARODD	0xC0
+#define	MX_PARMARK	0xA0
+#define	MX_PARSPACE	0x20
+
+#define MOXA_VERSION		"6.0k"
+
+#define MOXA_FW_HDRLEN		32
+
+#define MOXAMAJOR		172
+
+#define MAX_BOARDS		4	/* Don't change this value */
+#define MAX_PORTS_PER_BOARD	32	/* Don't change this value */
+#define MAX_PORTS		(MAX_BOARDS * MAX_PORTS_PER_BOARD)
+
+#define MOXA_IS_320(brd) ((brd)->boardType == MOXA_BOARD_C320_ISA || \
+		(brd)->boardType == MOXA_BOARD_C320_PCI)
+
+/*
+ *    Define the Moxa PCI vendor and device IDs.
+ */
+#define MOXA_BUS_TYPE_ISA	0
+#define MOXA_BUS_TYPE_PCI	1
+
+enum {
+	MOXA_BOARD_C218_PCI = 1,
+	MOXA_BOARD_C218_ISA,
+	MOXA_BOARD_C320_PCI,
+	MOXA_BOARD_C320_ISA,
+	MOXA_BOARD_CP204J,
+};
+
+static char *moxa_brdname[] =
+{
+	"C218 Turbo PCI series",
+	"C218 Turbo ISA series",
+	"C320 Turbo PCI series",
+	"C320 Turbo ISA series",
+	"CP-204J series",
+};
+
+#ifdef CONFIG_PCI
+static const struct pci_device_id moxa_pcibrds[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_C218),
+		.driver_data = MOXA_BOARD_C218_PCI },
+	{ PCI_DEVICE(PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_C320),
+		.driver_data = MOXA_BOARD_C320_PCI },
+	{ PCI_DEVICE(PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP204J),
+		.driver_data = MOXA_BOARD_CP204J },
+	{ 0 }
+};
+MODULE_DEVICE_TABLE(pci, moxa_pcibrds);
+#endif /* CONFIG_PCI */
+
+struct moxa_port;
+
+static struct moxa_board_conf {
+	int boardType;
+	int numPorts;
+	int busType;
+
+	unsigned int ready;
+
+	struct moxa_port *ports;
+
+	void __iomem *basemem;
+	void __iomem *intNdx;
+	void __iomem *intPend;
+	void __iomem *intTable;
+} moxa_boards[MAX_BOARDS];
+
+struct mxser_mstatus {
+	tcflag_t cflag;
+	int cts;
+	int dsr;
+	int ri;
+	int dcd;
+};
+
+struct moxaq_str {
+	int inq;
+	int outq;
+};
+
+struct moxa_port {
+	struct tty_port port;
+	struct moxa_board_conf *board;
+	void __iomem *tableAddr;
+
+	int type;
+	int cflag;
+	unsigned long statusflags;
+
+	u8 DCDState;		/* Protected by the port lock */
+	u8 lineCtrl;
+	u8 lowChkFlag;
+};
+
+struct mon_str {
+	int tick;
+	int rxcnt[MAX_PORTS];
+	int txcnt[MAX_PORTS];
+};
+
+/* statusflags */
+#define TXSTOPPED	1
+#define LOWWAIT 	2
+#define EMPTYWAIT	3
+
+
+#define WAKEUP_CHARS		256
+
+static int ttymajor = MOXAMAJOR;
+static struct mon_str moxaLog;
+static unsigned int moxaFuncTout = HZ / 2;
+static unsigned int moxaLowWaterChk;
+static DEFINE_MUTEX(moxa_openlock);
+static DEFINE_SPINLOCK(moxa_lock);
+
+static unsigned long baseaddr[MAX_BOARDS];
+static unsigned int type[MAX_BOARDS];
+static unsigned int numports[MAX_BOARDS];
+static struct tty_port moxa_service_port;
+
+MODULE_AUTHOR("William Chen");
+MODULE_DESCRIPTION("MOXA Intellio Family Multiport Board Device Driver");
+MODULE_LICENSE("GPL");
+MODULE_FIRMWARE("c218tunx.cod");
+MODULE_FIRMWARE("cp204unx.cod");
+MODULE_FIRMWARE("c320tunx.cod");
+
+module_param_array(type, uint, NULL, 0);
+MODULE_PARM_DESC(type, "card type: C218=2, C320=4");
+module_param_hw_array(baseaddr, ulong, ioport, NULL, 0);
+MODULE_PARM_DESC(baseaddr, "base address");
+module_param_array(numports, uint, NULL, 0);
+MODULE_PARM_DESC(numports, "numports (ignored for C218)");
+
+module_param(ttymajor, int, 0);
+
+/*
+ * static functions:
+ */
+static int moxa_open(struct tty_struct *, struct file *);
+static void moxa_close(struct tty_struct *, struct file *);
+static ssize_t moxa_write(struct tty_struct *, const u8 *, size_t);
+static unsigned int moxa_write_room(struct tty_struct *);
+static void moxa_flush_buffer(struct tty_struct *);
+static unsigned int moxa_chars_in_buffer(struct tty_struct *);
+static void moxa_set_termios(struct tty_struct *, const struct ktermios *);
+static void moxa_stop(struct tty_struct *);
+static void moxa_start(struct tty_struct *);
+static void moxa_hangup(struct tty_struct *);
+static int moxa_tiocmget(struct tty_struct *tty);
+static int moxa_tiocmset(struct tty_struct *tty,
+			 unsigned int set, unsigned int clear);
+static void moxa_poll(struct timer_list *);
+static void moxa_set_tty_param(struct tty_struct *, const struct ktermios *);
+static void moxa_shutdown(struct tty_port *);
+static bool moxa_carrier_raised(struct tty_port *);
+static void moxa_dtr_rts(struct tty_port *, bool);
+/*
+ * moxa board interface functions:
+ */
+static void MoxaPortEnable(struct moxa_port *);
+static void MoxaPortDisable(struct moxa_port *);
+static int MoxaPortSetTermio(struct moxa_port *, struct ktermios *, speed_t);
+static int MoxaPortGetLineOut(struct moxa_port *, bool *, bool *);
+static void MoxaPortLineCtrl(struct moxa_port *, bool, bool);
+static void MoxaPortFlowCtrl(struct moxa_port *, int, int, int, int, int);
+static int MoxaPortLineStatus(struct moxa_port *);
+static void MoxaPortFlushData(struct moxa_port *, int);
+static int MoxaPortWriteData(struct tty_struct *, const unsigned char *, int);
+static int MoxaPortReadData(struct moxa_port *);
+static unsigned int MoxaPortTxQueue(struct moxa_port *);
+static int MoxaPortRxQueue(struct moxa_port *);
+static unsigned int MoxaPortTxFree(struct moxa_port *);
+static void MoxaPortTxDisable(struct moxa_port *);
+static void MoxaPortTxEnable(struct moxa_port *);
+static int moxa_get_serial_info(struct tty_struct *, struct serial_struct *);
+static int moxa_set_serial_info(struct tty_struct *, struct serial_struct *);
+static void MoxaSetFifo(struct moxa_port *port, int enable);
+
+/*
+ * I/O functions
+ */
+
+static DEFINE_SPINLOCK(moxafunc_lock);
+
+static void moxa_wait_finish(void __iomem *ofsAddr)
+{
+	unsigned long end = jiffies + moxaFuncTout;
+
+	while (readw(ofsAddr + FuncCode) != 0)
+		if (time_after(jiffies, end))
+			return;
+	if (readw(ofsAddr + FuncCode) != 0)
+		printk_ratelimited(KERN_WARNING "moxa function expired\n");
+}
+
+static void moxafunc(void __iomem *ofsAddr, u16 cmd, u16 arg)
+{
+        unsigned long flags;
+        spin_lock_irqsave(&moxafunc_lock, flags);
+	writew(arg, ofsAddr + FuncArg);
+	writew(cmd, ofsAddr + FuncCode);
+	moxa_wait_finish(ofsAddr);
+	spin_unlock_irqrestore(&moxafunc_lock, flags);
+}
+
+static int moxafuncret(void __iomem *ofsAddr, u16 cmd, u16 arg)
+{
+        unsigned long flags;
+        u16 ret;
+        spin_lock_irqsave(&moxafunc_lock, flags);
+	writew(arg, ofsAddr + FuncArg);
+	writew(cmd, ofsAddr + FuncCode);
+	moxa_wait_finish(ofsAddr);
+	ret = readw(ofsAddr + FuncArg);
+	spin_unlock_irqrestore(&moxafunc_lock, flags);
+	return ret;
+}
+
+static void moxa_low_water_check(void __iomem *ofsAddr)
+{
+	u16 rptr, wptr, mask, len;
+
+	if (readb(ofsAddr + FlagStat) & Xoff_state) {
+		rptr = readw(ofsAddr + RXrptr);
+		wptr = readw(ofsAddr + RXwptr);
+		mask = readw(ofsAddr + RX_mask);
+		len = (wptr - rptr) & mask;
+		if (len <= Low_water)
+			moxafunc(ofsAddr, FC_SendXon, 0);
+	}
+}
+
+/*
+ * TTY operations
+ */
+
+static int moxa_ioctl(struct tty_struct *tty,
+		      unsigned int cmd, unsigned long arg)
+{
+	struct moxa_port *ch = tty->driver_data;
+	void __user *argp = (void __user *)arg;
+	int status, ret = 0;
+
+	if (tty->index == MAX_PORTS) {
+		if (cmd != MOXA_GETDATACOUNT && cmd != MOXA_GET_IOQUEUE &&
+				cmd != MOXA_GETMSTATUS)
+			return -EINVAL;
+	} else if (!ch)
+		return -ENODEV;
+
+	switch (cmd) {
+	case MOXA_GETDATACOUNT:
+		moxaLog.tick = jiffies;
+		if (copy_to_user(argp, &moxaLog, sizeof(moxaLog)))
+			ret = -EFAULT;
+		break;
+	case MOXA_FLUSH_QUEUE:
+		MoxaPortFlushData(ch, arg);
+		break;
+	case MOXA_GET_IOQUEUE: {
+		struct moxaq_str __user *argm = argp;
+		struct moxaq_str tmp;
+		struct moxa_port *p;
+		unsigned int i, j;
+
+		for (i = 0; i < MAX_BOARDS; i++) {
+			p = moxa_boards[i].ports;
+			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
+				memset(&tmp, 0, sizeof(tmp));
+				spin_lock_bh(&moxa_lock);
+				if (moxa_boards[i].ready) {
+					tmp.inq = MoxaPortRxQueue(p);
+					tmp.outq = MoxaPortTxQueue(p);
+				}
+				spin_unlock_bh(&moxa_lock);
+				if (copy_to_user(argm, &tmp, sizeof(tmp)))
+					return -EFAULT;
+			}
+		}
+		break;
+	} case MOXA_GET_OQUEUE:
+		status = MoxaPortTxQueue(ch);
+		ret = put_user(status, (unsigned long __user *)argp);
+		break;
+	case MOXA_GET_IQUEUE:
+		status = MoxaPortRxQueue(ch);
+		ret = put_user(status, (unsigned long __user *)argp);
+		break;
+	case MOXA_GETMSTATUS: {
+		struct mxser_mstatus __user *argm = argp;
+		struct mxser_mstatus tmp;
+		struct moxa_port *p;
+		unsigned int i, j;
+
+		for (i = 0; i < MAX_BOARDS; i++) {
+			p = moxa_boards[i].ports;
+			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
+				struct tty_struct *ttyp;
+				memset(&tmp, 0, sizeof(tmp));
+				spin_lock_bh(&moxa_lock);
+				if (!moxa_boards[i].ready) {
+				        spin_unlock_bh(&moxa_lock);
+					goto copy;
+                                }
+
+				status = MoxaPortLineStatus(p);
+				spin_unlock_bh(&moxa_lock);
+
+				if (status & 1)
+					tmp.cts = 1;
+				if (status & 2)
+					tmp.dsr = 1;
+				if (status & 4)
+					tmp.dcd = 1;
+
+				ttyp = tty_port_tty_get(&p->port);
+				if (!ttyp)
+					tmp.cflag = p->cflag;
+				else
+					tmp.cflag = ttyp->termios.c_cflag;
+				tty_kref_put(ttyp);
+copy:
+				if (copy_to_user(argm, &tmp, sizeof(tmp)))
+					return -EFAULT;
+			}
+		}
+		break;
+	}
+	default:
+		ret = -ENOIOCTLCMD;
+	}
+	return ret;
+}
+
+static int moxa_break_ctl(struct tty_struct *tty, int state)
+{
+	struct moxa_port *port = tty->driver_data;
+
+	moxafunc(port->tableAddr, state ? FC_SendBreak : FC_StopBreak,
+			Magic_code);
+	return 0;
+}
+
+static const struct tty_operations moxa_ops = {
+	.open = moxa_open,
+	.close = moxa_close,
+	.write = moxa_write,
+	.write_room = moxa_write_room,
+	.flush_buffer = moxa_flush_buffer,
+	.chars_in_buffer = moxa_chars_in_buffer,
+	.ioctl = moxa_ioctl,
+	.set_termios = moxa_set_termios,
+	.stop = moxa_stop,
+	.start = moxa_start,
+	.hangup = moxa_hangup,
+	.break_ctl = moxa_break_ctl,
+	.tiocmget = moxa_tiocmget,
+	.tiocmset = moxa_tiocmset,
+	.set_serial = moxa_set_serial_info,
+	.get_serial = moxa_get_serial_info,
+};
+
+static const struct tty_port_operations moxa_port_ops = {
+	.carrier_raised = moxa_carrier_raised,
+	.dtr_rts = moxa_dtr_rts,
+	.shutdown = moxa_shutdown,
+};
+
+static struct tty_driver *moxaDriver;
+static DEFINE_TIMER(moxaTimer, moxa_poll);
+
+/*
+ * HW init
+ */
+
+static int moxa_check_fw_model(struct moxa_board_conf *brd, u8 model)
+{
+	switch (brd->boardType) {
+	case MOXA_BOARD_C218_ISA:
+	case MOXA_BOARD_C218_PCI:
+		if (model != 1)
+			goto err;
+		break;
+	case MOXA_BOARD_CP204J:
+		if (model != 3)
+			goto err;
+		break;
+	default:
+		if (model != 2)
+			goto err;
+		break;
+	}
+	return 0;
+err:
+	return -EINVAL;
+}
+
+static int moxa_check_fw(const void *ptr)
+{
+	const __le16 *lptr = ptr;
+
+	if (*lptr != cpu_to_le16(0x7980))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int moxa_load_bios(struct moxa_board_conf *brd, const u8 *buf,
+		size_t len)
+{
+	void __iomem *baseAddr = brd->basemem;
+	u16 tmp;
+
+	writeb(HW_reset, baseAddr + Control_reg);	/* reset */
+	msleep(10);
+	memset_io(baseAddr, 0, 4096);
+	memcpy_toio(baseAddr, buf, len);	/* download BIOS */
+	writeb(0, baseAddr + Control_reg);	/* restart */
+
+	msleep(2000);
+
+	switch (brd->boardType) {
+	case MOXA_BOARD_C218_ISA:
+	case MOXA_BOARD_C218_PCI:
+		tmp = readw(baseAddr + C218_key);
+		if (tmp != C218_KeyCode)
+			goto err;
+		break;
+	case MOXA_BOARD_CP204J:
+		tmp = readw(baseAddr + C218_key);
+		if (tmp != CP204J_KeyCode)
+			goto err;
+		break;
+	default:
+		tmp = readw(baseAddr + C320_key);
+		if (tmp != C320_KeyCode)
+			goto err;
+		tmp = readw(baseAddr + C320_status);
+		if (tmp != STS_init) {
+			printk(KERN_ERR "MOXA: bios upload failed -- CPU/Basic "
+					"module not found\n");
+			return -EIO;
+		}
+		break;
+	}
+
+	return 0;
+err:
+	printk(KERN_ERR "MOXA: bios upload failed -- board not found\n");
+	return -EIO;
+}
+
+static int moxa_load_320b(struct moxa_board_conf *brd, const u8 *ptr,
+		size_t len)
+{
+	void __iomem *baseAddr = brd->basemem;
+
+	if (len < 7168) {
+		printk(KERN_ERR "MOXA: invalid 320 bios -- too short\n");
+		return -EINVAL;
+	}
+
+	writew(len - 7168 - 2, baseAddr + C320bapi_len);
+	writeb(1, baseAddr + Control_reg);	/* Select Page 1 */
+	memcpy_toio(baseAddr + DynPage_addr, ptr, 7168);
+	writeb(2, baseAddr + Control_reg);	/* Select Page 2 */
+	memcpy_toio(baseAddr + DynPage_addr, ptr + 7168, len - 7168);
+
+	return 0;
+}
+
+static int moxa_real_load_code(struct moxa_board_conf *brd, const void *ptr,
+		size_t len)
+{
+	void __iomem *baseAddr = brd->basemem;
+	const __le16 *uptr = ptr;
+	size_t wlen, len2, j;
+	unsigned long key, loadbuf, loadlen, checksum, checksum_ok;
+	unsigned int i, retry;
+	u16 usum, keycode;
+
+	keycode = (brd->boardType == MOXA_BOARD_CP204J) ? CP204J_KeyCode :
+				C218_KeyCode;
+
+	switch (brd->boardType) {
+	case MOXA_BOARD_CP204J:
+	case MOXA_BOARD_C218_ISA:
+	case MOXA_BOARD_C218_PCI:
+		key = C218_key;
+		loadbuf = C218_LoadBuf;
+		loadlen = C218DLoad_len;
+		checksum = C218check_sum;
+		checksum_ok = C218chksum_ok;
+		break;
+	default:
+		key = C320_key;
+		keycode = C320_KeyCode;
+		loadbuf = C320_LoadBuf;
+		loadlen = C320DLoad_len;
+		checksum = C320check_sum;
+		checksum_ok = C320chksum_ok;
+		break;
+	}
+
+	usum = 0;
+	wlen = len >> 1;
+	for (i = 0; i < wlen; i++)
+		usum += le16_to_cpu(uptr[i]);
+	retry = 0;
+	do {
+		wlen = len >> 1;
+		j = 0;
+		while (wlen) {
+			len2 = (wlen > 2048) ? 2048 : wlen;
+			wlen -= len2;
+			memcpy_toio(baseAddr + loadbuf, ptr + j, len2 << 1);
+			j += len2 << 1;
+
+			writew(len2, baseAddr + loadlen);
+			writew(0, baseAddr + key);
+			for (i = 0; i < 100; i++) {
+				if (readw(baseAddr + key) == keycode)
+					break;
+				msleep(10);
+			}
+			if (readw(baseAddr + key) != keycode)
+				return -EIO;
+		}
+		writew(0, baseAddr + loadlen);
+		writew(usum, baseAddr + checksum);
+		writew(0, baseAddr + key);
+		for (i = 0; i < 100; i++) {
+			if (readw(baseAddr + key) == keycode)
+				break;
+			msleep(10);
+		}
+		retry++;
+	} while ((readb(baseAddr + checksum_ok) != 1) && (retry < 3));
+	if (readb(baseAddr + checksum_ok) != 1)
+		return -EIO;
+
+	writew(0, baseAddr + key);
+	for (i = 0; i < 600; i++) {
+		if (readw(baseAddr + Magic_no) == Magic_code)
+			break;
+		msleep(10);
+	}
+	if (readw(baseAddr + Magic_no) != Magic_code)
+		return -EIO;
+
+	if (MOXA_IS_320(brd)) {
+		if (brd->busType == MOXA_BUS_TYPE_PCI) {	/* ASIC board */
+			writew(0x3800, baseAddr + TMS320_PORT1);
+			writew(0x3900, baseAddr + TMS320_PORT2);
+			writew(28499, baseAddr + TMS320_CLOCK);
+		} else {
+			writew(0x3200, baseAddr + TMS320_PORT1);
+			writew(0x3400, baseAddr + TMS320_PORT2);
+			writew(19999, baseAddr + TMS320_CLOCK);
+		}
+	}
+	writew(1, baseAddr + Disable_IRQ);
+	writew(0, baseAddr + Magic_no);
+	for (i = 0; i < 500; i++) {
+		if (readw(baseAddr + Magic_no) == Magic_code)
+			break;
+		msleep(10);
+	}
+	if (readw(baseAddr + Magic_no) != Magic_code)
+		return -EIO;
+
+	if (MOXA_IS_320(brd)) {
+		j = readw(baseAddr + Module_cnt);
+		if (j <= 0)
+			return -EIO;
+		brd->numPorts = j * 8;
+		writew(j, baseAddr + Module_no);
+		writew(0, baseAddr + Magic_no);
+		for (i = 0; i < 600; i++) {
+			if (readw(baseAddr + Magic_no) == Magic_code)
+				break;
+			msleep(10);
+		}
+		if (readw(baseAddr + Magic_no) != Magic_code)
+			return -EIO;
+	}
+	brd->intNdx = baseAddr + IRQindex;
+	brd->intPend = baseAddr + IRQpending;
+	brd->intTable = baseAddr + IRQtable;
+
+	return 0;
+}
+
+static int moxa_load_code(struct moxa_board_conf *brd, const void *ptr,
+		size_t len)
+{
+	void __iomem *ofsAddr, *baseAddr = brd->basemem;
+	struct moxa_port *port;
+	int retval, i;
+
+	if (len % 2) {
+		printk(KERN_ERR "MOXA: bios length is not even\n");
+		return -EINVAL;
+	}
+
+	retval = moxa_real_load_code(brd, ptr, len); /* may change numPorts */
+	if (retval)
+		return retval;
+
+	switch (brd->boardType) {
+	case MOXA_BOARD_C218_ISA:
+	case MOXA_BOARD_C218_PCI:
+	case MOXA_BOARD_CP204J:
+		port = brd->ports;
+		for (i = 0; i < brd->numPorts; i++, port++) {
+			port->board = brd;
+			port->DCDState = 0;
+			port->tableAddr = baseAddr + Extern_table +
+					Extern_size * i;
+			ofsAddr = port->tableAddr;
+			writew(C218rx_mask, ofsAddr + RX_mask);
+			writew(C218tx_mask, ofsAddr + TX_mask);
+			writew(C218rx_spage + i * C218buf_pageno, ofsAddr + Page_rxb);
+			writew(readw(ofsAddr + Page_rxb) + C218rx_pageno, ofsAddr + EndPage_rxb);
+
+			writew(C218tx_spage + i * C218buf_pageno, ofsAddr + Page_txb);
+			writew(readw(ofsAddr + Page_txb) + C218tx_pageno, ofsAddr + EndPage_txb);
+
+		}
+		break;
+	default:
+		port = brd->ports;
+		for (i = 0; i < brd->numPorts; i++, port++) {
+			port->board = brd;
+			port->DCDState = 0;
+			port->tableAddr = baseAddr + Extern_table +
+					Extern_size * i;
+			ofsAddr = port->tableAddr;
+			switch (brd->numPorts) {
+			case 8:
+				writew(C320p8rx_mask, ofsAddr + RX_mask);
+				writew(C320p8tx_mask, ofsAddr + TX_mask);
+				writew(C320p8rx_spage + i * C320p8buf_pgno, ofsAddr + Page_rxb);
+				writew(readw(ofsAddr + Page_rxb) + C320p8rx_pgno, ofsAddr + EndPage_rxb);
+				writew(C320p8tx_spage + i * C320p8buf_pgno, ofsAddr + Page_txb);
+				writew(readw(ofsAddr + Page_txb) + C320p8tx_pgno, ofsAddr + EndPage_txb);
+
+				break;
+			case 16:
+				writew(C320p16rx_mask, ofsAddr + RX_mask);
+				writew(C320p16tx_mask, ofsAddr + TX_mask);
+				writew(C320p16rx_spage + i * C320p16buf_pgno, ofsAddr + Page_rxb);
+				writew(readw(ofsAddr + Page_rxb) + C320p16rx_pgno, ofsAddr + EndPage_rxb);
+				writew(C320p16tx_spage + i * C320p16buf_pgno, ofsAddr + Page_txb);
+				writew(readw(ofsAddr + Page_txb) + C320p16tx_pgno, ofsAddr + EndPage_txb);
+				break;
+
+			case 24:
+				writew(C320p24rx_mask, ofsAddr + RX_mask);
+				writew(C320p24tx_mask, ofsAddr + TX_mask);
+				writew(C320p24rx_spage + i * C320p24buf_pgno, ofsAddr + Page_rxb);
+				writew(readw(ofsAddr + Page_rxb) + C320p24rx_pgno, ofsAddr + EndPage_rxb);
+				writew(C320p24tx_spage + i * C320p24buf_pgno, ofsAddr + Page_txb);
+				writew(readw(ofsAddr + Page_txb), ofsAddr + EndPage_txb);
+				break;
+			case 32:
+				writew(C320p32rx_mask, ofsAddr + RX_mask);
+				writew(C320p32tx_mask, ofsAddr + TX_mask);
+				writew(C320p32tx_ofs, ofsAddr + Ofs_txb);
+				writew(C320p32rx_spage + i * C320p32buf_pgno, ofsAddr + Page_rxb);
+				writew(readb(ofsAddr + Page_rxb), ofsAddr + EndPage_rxb);
+				writew(C320p32tx_spage + i * C320p32buf_pgno, ofsAddr + Page_txb);
+				writew(readw(ofsAddr + Page_txb), ofsAddr + EndPage_txb);
+				break;
+			}
+		}
+		break;
+	}
+	return 0;
+}
+
+static int moxa_load_fw(struct moxa_board_conf *brd, const struct firmware *fw)
+{
+	const void *ptr = fw->data;
+	char rsn[64];
+	u16 lens[5];
+	size_t len;
+	unsigned int a, lenp, lencnt;
+	int ret = -EINVAL;
+	struct {
+		__le32 magic;	/* 0x34303430 */
+		u8 reserved1[2];
+		u8 type;	/* UNIX = 3 */
+		u8 model;	/* C218T=1, C320T=2, CP204=3 */
+		u8 reserved2[8];
+		__le16 len[5];
+	} const *hdr = ptr;
+
+	BUILD_BUG_ON(ARRAY_SIZE(hdr->len) != ARRAY_SIZE(lens));
+
+	if (fw->size < MOXA_FW_HDRLEN) {
+		strcpy(rsn, "too short (even header won't fit)");
+		goto err;
+	}
+	if (hdr->magic != cpu_to_le32(0x30343034)) {
+		sprintf(rsn, "bad magic: %.8x", le32_to_cpu(hdr->magic));
+		goto err;
+	}
+	if (hdr->type != 3) {
+		sprintf(rsn, "not for linux, type is %u", hdr->type);
+		goto err;
+	}
+	if (moxa_check_fw_model(brd, hdr->model)) {
+		sprintf(rsn, "not for this card, model is %u", hdr->model);
+		goto err;
+	}
+
+	len = MOXA_FW_HDRLEN;
+	lencnt = hdr->model == 2 ? 5 : 3;
+	for (a = 0; a < ARRAY_SIZE(lens); a++) {
+		lens[a] = le16_to_cpu(hdr->len[a]);
+		if (lens[a] && len + lens[a] <= fw->size &&
+				moxa_check_fw(&fw->data[len]))
+			printk(KERN_WARNING "MOXA firmware: unexpected input "
+				"at offset %u, but going on\n", (u32)len);
+		if (!lens[a] && a < lencnt) {
+			sprintf(rsn, "too few entries in fw file");
+			goto err;
+		}
+		len += lens[a];
+	}
+
+	if (len != fw->size) {
+		sprintf(rsn, "bad length: %u (should be %u)", (u32)fw->size,
+				(u32)len);
+		goto err;
+	}
+
+	ptr += MOXA_FW_HDRLEN;
+	lenp = 0; /* bios */
+
+	strcpy(rsn, "read above");
+
+	ret = moxa_load_bios(brd, ptr, lens[lenp]);
+	if (ret)
+		goto err;
+
+	/* we skip the tty section (lens[1]), since we don't need it */
+	ptr += lens[lenp] + lens[lenp + 1];
+	lenp += 2; /* comm */
+
+	if (hdr->model == 2) {
+		ret = moxa_load_320b(brd, ptr, lens[lenp]);
+		if (ret)
+			goto err;
+		/* skip another tty */
+		ptr += lens[lenp] + lens[lenp + 1];
+		lenp += 2;
+	}
+
+	ret = moxa_load_code(brd, ptr, lens[lenp]);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	printk(KERN_ERR "firmware failed to load, reason: %s\n", rsn);
+	return ret;
+}
+
+static int moxa_init_board(struct moxa_board_conf *brd, struct device *dev)
+{
+	const struct firmware *fw;
+	const char *file;
+	struct moxa_port *p;
+	unsigned int i, first_idx;
+	int ret;
+
+	brd->ports = kcalloc(MAX_PORTS_PER_BOARD, sizeof(*brd->ports),
+			GFP_KERNEL);
+	if (brd->ports == NULL) {
+		printk(KERN_ERR "cannot allocate memory for ports\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	for (i = 0, p = brd->ports; i < MAX_PORTS_PER_BOARD; i++, p++) {
+		tty_port_init(&p->port);
+		p->port.ops = &moxa_port_ops;
+		p->type = PORT_16550A;
+		p->cflag = B9600 | CS8 | CREAD | CLOCAL | HUPCL;
+	}
+
+	switch (brd->boardType) {
+	case MOXA_BOARD_C218_ISA:
+	case MOXA_BOARD_C218_PCI:
+		file = "c218tunx.cod";
+		break;
+	case MOXA_BOARD_CP204J:
+		file = "cp204unx.cod";
+		break;
+	default:
+		file = "c320tunx.cod";
+		break;
+	}
+
+	ret = request_firmware(&fw, file, dev);
+	if (ret) {
+		printk(KERN_ERR "MOXA: request_firmware failed. Make sure "
+				"you've placed '%s' file into your firmware "
+				"loader directory (e.g. /lib/firmware)\n",
+				file);
+		goto err_free;
+	}
+
+	ret = moxa_load_fw(brd, fw);
+
+	release_firmware(fw);
+
+	if (ret)
+		goto err_free;
+
+	spin_lock_bh(&moxa_lock);
+	brd->ready = 1;
+	if (!timer_pending(&moxaTimer))
+		mod_timer(&moxaTimer, jiffies + HZ / 50);
+	spin_unlock_bh(&moxa_lock);
+
+	first_idx = (brd - moxa_boards) * MAX_PORTS_PER_BOARD;
+	for (i = 0; i < brd->numPorts; i++)
+		tty_port_register_device(&brd->ports[i].port, moxaDriver,
+				first_idx + i, dev);
+
+	return 0;
+err_free:
+	for (i = 0; i < MAX_PORTS_PER_BOARD; i++)
+		tty_port_destroy(&brd->ports[i].port);
+	kfree(brd->ports);
+err:
+	return ret;
+}
+
+static void moxa_board_deinit(struct moxa_board_conf *brd)
+{
+	unsigned int a, opened, first_idx;
+
+	mutex_lock(&moxa_openlock);
+	spin_lock_bh(&moxa_lock);
+	brd->ready = 0;
+	spin_unlock_bh(&moxa_lock);
+
+	/* pci hot-un-plug support */
+	for (a = 0; a < brd->numPorts; a++)
+		if (tty_port_initialized(&brd->ports[a].port))
+			tty_port_tty_hangup(&brd->ports[a].port, false);
+
+	for (a = 0; a < MAX_PORTS_PER_BOARD; a++)
+		tty_port_destroy(&brd->ports[a].port);
+
+	while (1) {
+		opened = 0;
+		for (a = 0; a < brd->numPorts; a++)
+			if (tty_port_initialized(&brd->ports[a].port))
+				opened++;
+		mutex_unlock(&moxa_openlock);
+		if (!opened)
+			break;
+		msleep(50);
+		mutex_lock(&moxa_openlock);
+	}
+
+	first_idx = (brd - moxa_boards) * MAX_PORTS_PER_BOARD;
+	for (a = 0; a < brd->numPorts; a++)
+		tty_unregister_device(moxaDriver, first_idx + a);
+
+	iounmap(brd->basemem);
+	brd->basemem = NULL;
+	kfree(brd->ports);
+}
+
+#ifdef CONFIG_PCI
+static int moxa_pci_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	struct moxa_board_conf *board;
+	unsigned int i;
+	int board_type = ent->driver_data;
+	int retval;
+
+	retval = pci_enable_device(pdev);
+	if (retval) {
+		dev_err(&pdev->dev, "can't enable pci device\n");
+		goto err;
+	}
+
+	for (i = 0; i < MAX_BOARDS; i++)
+		if (moxa_boards[i].basemem == NULL)
+			break;
+
+	retval = -ENODEV;
+	if (i >= MAX_BOARDS) {
+		dev_warn(&pdev->dev, "more than %u MOXA Intellio family boards "
+				"found. Board is ignored.\n", MAX_BOARDS);
+		goto err;
+	}
+
+	board = &moxa_boards[i];
+
+	retval = pci_request_region(pdev, 2, "moxa-base");
+	if (retval) {
+		dev_err(&pdev->dev, "can't request pci region 2\n");
+		goto err;
+	}
+
+	board->basemem = ioremap(pci_resource_start(pdev, 2), 0x4000);
+	if (board->basemem == NULL) {
+		dev_err(&pdev->dev, "can't remap io space 2\n");
+		retval = -ENOMEM;
+		goto err_reg;
+	}
+
+	board->boardType = board_type;
+	switch (board_type) {
+	case MOXA_BOARD_C218_ISA:
+	case MOXA_BOARD_C218_PCI:
+		board->numPorts = 8;
+		break;
+
+	case MOXA_BOARD_CP204J:
+		board->numPorts = 4;
+		break;
+	default:
+		board->numPorts = 0;
+		break;
+	}
+	board->busType = MOXA_BUS_TYPE_PCI;
+
+	retval = moxa_init_board(board, &pdev->dev);
+	if (retval)
+		goto err_base;
+
+	pci_set_drvdata(pdev, board);
+
+	dev_info(&pdev->dev, "board '%s' ready (%u ports, firmware loaded)\n",
+			moxa_brdname[board_type - 1], board->numPorts);
+
+	return 0;
+err_base:
+	iounmap(board->basemem);
+	board->basemem = NULL;
+err_reg:
+	pci_release_region(pdev, 2);
+err:
+	return retval;
+}
+
+static void moxa_pci_remove(struct pci_dev *pdev)
+{
+	struct moxa_board_conf *brd = pci_get_drvdata(pdev);
+
+	moxa_board_deinit(brd);
+
+	pci_release_region(pdev, 2);
+}
+
+static struct pci_driver moxa_pci_driver = {
+	.name = "moxa",
+	.id_table = moxa_pcibrds,
+	.probe = moxa_pci_probe,
+	.remove = moxa_pci_remove
+};
+#endif /* CONFIG_PCI */
+
+static int __init moxa_init(void)
+{
+	unsigned int isabrds = 0;
+	int retval = 0;
+	struct moxa_board_conf *brd = moxa_boards;
+	unsigned int i;
+
+	printk(KERN_INFO "MOXA Intellio family driver version %s\n",
+			MOXA_VERSION);
+
+	tty_port_init(&moxa_service_port);
+
+	moxaDriver = tty_alloc_driver(MAX_PORTS + 1,
+			TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(moxaDriver))
+		return PTR_ERR(moxaDriver);
+
+	moxaDriver->name = "ttyMX";
+	moxaDriver->major = ttymajor;
+	moxaDriver->minor_start = 0;
+	moxaDriver->type = TTY_DRIVER_TYPE_SERIAL;
+	moxaDriver->subtype = SERIAL_TYPE_NORMAL;
+	moxaDriver->init_termios = tty_std_termios;
+	moxaDriver->init_termios.c_cflag = B9600 | CS8 | CREAD | CLOCAL | HUPCL;
+	moxaDriver->init_termios.c_ispeed = 9600;
+	moxaDriver->init_termios.c_ospeed = 9600;
+	tty_set_operations(moxaDriver, &moxa_ops);
+	/* Having one more port only for ioctls is ugly */
+	tty_port_link_device(&moxa_service_port, moxaDriver, MAX_PORTS);
+
+	if (tty_register_driver(moxaDriver)) {
+		printk(KERN_ERR "can't register MOXA Smartio tty driver!\n");
+		tty_driver_kref_put(moxaDriver);
+		return -1;
+	}
+
+	/* Find the boards defined from module args. */
+
+	for (i = 0; i < MAX_BOARDS; i++) {
+		if (!baseaddr[i])
+			break;
+		if (type[i] == MOXA_BOARD_C218_ISA ||
+				type[i] == MOXA_BOARD_C320_ISA) {
+			pr_debug("Moxa board %2d: %s board(baseAddr=%lx)\n",
+					isabrds + 1, moxa_brdname[type[i] - 1],
+					baseaddr[i]);
+			brd->boardType = type[i];
+			brd->numPorts = type[i] == MOXA_BOARD_C218_ISA ? 8 :
+					numports[i];
+			brd->busType = MOXA_BUS_TYPE_ISA;
+			brd->basemem = ioremap(baseaddr[i], 0x4000);
+			if (!brd->basemem) {
+				printk(KERN_ERR "MOXA: can't remap %lx\n",
+						baseaddr[i]);
+				continue;
+			}
+			if (moxa_init_board(brd, NULL)) {
+				iounmap(brd->basemem);
+				brd->basemem = NULL;
+				continue;
+			}
+
+			printk(KERN_INFO "MOXA isa board found at 0x%.8lx and "
+					"ready (%u ports, firmware loaded)\n",
+					baseaddr[i], brd->numPorts);
+
+			brd++;
+			isabrds++;
+		}
+	}
+
+#ifdef CONFIG_PCI
+	retval = pci_register_driver(&moxa_pci_driver);
+	if (retval) {
+		printk(KERN_ERR "Can't register MOXA pci driver!\n");
+		if (isabrds)
+			retval = 0;
+	}
+#endif
+
+	return retval;
+}
+
+static void __exit moxa_exit(void)
+{
+	unsigned int i;
+
+#ifdef CONFIG_PCI
+	pci_unregister_driver(&moxa_pci_driver);
+#endif
+
+	for (i = 0; i < MAX_BOARDS; i++) /* ISA boards */
+		if (moxa_boards[i].ready)
+			moxa_board_deinit(&moxa_boards[i]);
+
+	del_timer_sync(&moxaTimer);
+
+	tty_unregister_driver(moxaDriver);
+	tty_driver_kref_put(moxaDriver);
+}
+
+module_init(moxa_init);
+module_exit(moxa_exit);
+
+static void moxa_shutdown(struct tty_port *port)
+{
+	struct moxa_port *ch = container_of(port, struct moxa_port, port);
+        MoxaPortDisable(ch);
+	MoxaPortFlushData(ch, 2);
+}
+
+static bool moxa_carrier_raised(struct tty_port *port)
+{
+	struct moxa_port *ch = container_of(port, struct moxa_port, port);
+	int dcd;
+
+	spin_lock_irq(&port->lock);
+	dcd = ch->DCDState;
+	spin_unlock_irq(&port->lock);
+	return dcd;
+}
+
+static void moxa_dtr_rts(struct tty_port *port, bool active)
+{
+	struct moxa_port *ch = container_of(port, struct moxa_port, port);
+	MoxaPortLineCtrl(ch, active, active);
+}
+
+
+static int moxa_open(struct tty_struct *tty, struct file *filp)
+{
+	struct moxa_board_conf *brd;
+	struct moxa_port *ch;
+	int port;
+
+	port = tty->index;
+	if (port == MAX_PORTS) {
+		return capable(CAP_SYS_ADMIN) ? 0 : -EPERM;
+	}
+	if (mutex_lock_interruptible(&moxa_openlock))
+		return -ERESTARTSYS;
+	brd = &moxa_boards[port / MAX_PORTS_PER_BOARD];
+	if (!brd->ready) {
+		mutex_unlock(&moxa_openlock);
+		return -ENODEV;
+	}
+
+	if (port % MAX_PORTS_PER_BOARD >= brd->numPorts) {
+		mutex_unlock(&moxa_openlock);
+		return -ENODEV;
+	}
+
+	ch = &brd->ports[port % MAX_PORTS_PER_BOARD];
+	ch->port.count++;
+	tty->driver_data = ch;
+	tty_port_tty_set(&ch->port, tty);
+	mutex_lock(&ch->port.mutex);
+	if (!tty_port_initialized(&ch->port)) {
+		ch->statusflags = 0;
+		moxa_set_tty_param(tty, &tty->termios);
+		MoxaPortLineCtrl(ch, true, true);
+		MoxaPortEnable(ch);
+		MoxaSetFifo(ch, ch->type == PORT_16550A);
+		tty_port_set_initialized(&ch->port, true);
+	}
+	mutex_unlock(&ch->port.mutex);
+	mutex_unlock(&moxa_openlock);
+
+	return tty_port_block_til_ready(&ch->port, tty, filp);
+}
+
+static void moxa_close(struct tty_struct *tty, struct file *filp)
+{
+	struct moxa_port *ch = tty->driver_data;
+	ch->cflag = tty->termios.c_cflag;
+	tty_port_close(&ch->port, tty, filp);
+}
+
+static ssize_t moxa_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct moxa_port *ch = tty->driver_data;
+	unsigned long flags;
+	int len;
+
+	if (ch == NULL)
+		return 0;
+
+	spin_lock_irqsave(&moxa_lock, flags);
+	len = MoxaPortWriteData(tty, buf, count);
+	spin_unlock_irqrestore(&moxa_lock, flags);
+
+	set_bit(LOWWAIT, &ch->statusflags);
+	return len;
+}
+
+static unsigned int moxa_write_room(struct tty_struct *tty)
+{
+	struct moxa_port *ch;
+
+	if (tty->flow.stopped)
+		return 0;
+	ch = tty->driver_data;
+	if (ch == NULL)
+		return 0;
+	return MoxaPortTxFree(ch);
+}
+
+static void moxa_flush_buffer(struct tty_struct *tty)
+{
+	struct moxa_port *ch = tty->driver_data;
+
+	if (ch == NULL)
+		return;
+	MoxaPortFlushData(ch, 1);
+	tty_wakeup(tty);
+}
+
+static unsigned int moxa_chars_in_buffer(struct tty_struct *tty)
+{
+	struct moxa_port *ch = tty->driver_data;
+	unsigned int chars;
+
+	chars = MoxaPortTxQueue(ch);
+	if (chars)
+		/*
+		 * Make it possible to wakeup anything waiting for output
+		 * in tty_ioctl.c, etc.
+		 */
+        	set_bit(EMPTYWAIT, &ch->statusflags);
+	return chars;
+}
+
+static int moxa_tiocmget(struct tty_struct *tty)
+{
+	struct moxa_port *ch = tty->driver_data;
+	bool dtr_active, rts_active;
+	int flag = 0;
+	int status;
+
+	MoxaPortGetLineOut(ch, &dtr_active, &rts_active);
+	if (dtr_active)
+		flag |= TIOCM_DTR;
+	if (rts_active)
+		flag |= TIOCM_RTS;
+	status = MoxaPortLineStatus(ch);
+	if (status & 1)
+		flag |= TIOCM_CTS;
+	if (status & 2)
+		flag |= TIOCM_DSR;
+	if (status & 4)
+		flag |= TIOCM_CD;
+	return flag;
+}
+
+static int moxa_tiocmset(struct tty_struct *tty,
+			 unsigned int set, unsigned int clear)
+{
+	bool dtr_active, rts_active;
+	struct moxa_port *ch;
+
+	mutex_lock(&moxa_openlock);
+	ch = tty->driver_data;
+	if (!ch) {
+		mutex_unlock(&moxa_openlock);
+		return -EINVAL;
+	}
+
+	MoxaPortGetLineOut(ch, &dtr_active, &rts_active);
+	if (set & TIOCM_RTS)
+		rts_active = true;
+	if (set & TIOCM_DTR)
+		dtr_active = true;
+	if (clear & TIOCM_RTS)
+		rts_active = false;
+	if (clear & TIOCM_DTR)
+		dtr_active = false;
+	MoxaPortLineCtrl(ch, dtr_active, rts_active);
+	mutex_unlock(&moxa_openlock);
+	return 0;
+}
+
+static void moxa_set_termios(struct tty_struct *tty,
+		             const struct ktermios *old_termios)
+{
+	struct moxa_port *ch = tty->driver_data;
+
+	if (ch == NULL)
+		return;
+	moxa_set_tty_param(tty, old_termios);
+	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
+		wake_up_interruptible(&ch->port.open_wait);
+}
+
+static void moxa_stop(struct tty_struct *tty)
+{
+	struct moxa_port *ch = tty->driver_data;
+
+	if (ch == NULL)
+		return;
+	MoxaPortTxDisable(ch);
+	set_bit(TXSTOPPED, &ch->statusflags);
+}
+
+
+static void moxa_start(struct tty_struct *tty)
+{
+	struct moxa_port *ch = tty->driver_data;
+
+	if (ch == NULL)
+		return;
+
+	if (!test_bit(TXSTOPPED, &ch->statusflags))
+		return;
+
+	MoxaPortTxEnable(ch);
+	clear_bit(TXSTOPPED, &ch->statusflags);
+}
+
+static void moxa_hangup(struct tty_struct *tty)
+{
+	struct moxa_port *ch = tty->driver_data;
+	tty_port_hangup(&ch->port);
+}
+
+static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
+{
+	unsigned long flags;
+	dcd = !!dcd;
+
+	spin_lock_irqsave(&p->port.lock, flags);
+	if (dcd != p->DCDState) {
+        	p->DCDState = dcd;
+        	spin_unlock_irqrestore(&p->port.lock, flags);
+		if (!dcd)
+			tty_port_tty_hangup(&p->port, true);
+	}
+	else
+		spin_unlock_irqrestore(&p->port.lock, flags);
+}
+
+static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
+		u16 __iomem *ip)
+{
+	struct tty_struct *tty = tty_port_tty_get(&p->port);
+	bool inited = tty_port_initialized(&p->port);
+	void __iomem *ofsAddr;
+	u16 intr;
+
+	if (tty) {
+		if (test_bit(EMPTYWAIT, &p->statusflags) &&
+				MoxaPortTxQueue(p) == 0) {
+			clear_bit(EMPTYWAIT, &p->statusflags);
+			tty_wakeup(tty);
+		}
+		if (test_bit(LOWWAIT, &p->statusflags) && !tty->flow.stopped &&
+				MoxaPortTxQueue(p) <= WAKEUP_CHARS) {
+			clear_bit(LOWWAIT, &p->statusflags);
+			tty_wakeup(tty);
+		}
+
+		if (inited && !tty_throttled(tty) &&
+				MoxaPortRxQueue(p) > 0) { /* RX */
+			MoxaPortReadData(p);
+			tty_flip_buffer_push(&p->port);
+		}
+	} else {
+		clear_bit(EMPTYWAIT, &p->statusflags);
+		MoxaPortFlushData(p, 0); /* flush RX */
+	}
+
+	if (!handle) /* nothing else to do */
+		goto put;
+
+	intr = readw(ip); /* port irq status */
+	if (intr == 0)
+		goto put;
+
+	writew(0, ip); /* ACK port */
+	ofsAddr = p->tableAddr;
+	if (intr & IntrTx) /* disable tx intr */
+		writew(readw(ofsAddr + HostStat) & ~WakeupTx,
+				ofsAddr + HostStat);
+
+	if (!inited)
+		goto put;
+
+	if (tty && (intr & IntrBreak) && !I_IGNBRK(tty)) { /* BREAK */
+		tty_insert_flip_char(&p->port, 0, TTY_BREAK);
+		tty_flip_buffer_push(&p->port);
+	}
+
+	if (intr & IntrLine)
+		moxa_new_dcdstate(p, readb(ofsAddr + FlagStat) & DCD_state);
+put:
+	tty_kref_put(tty);
+
+	return 0;
+}
+
+static void moxa_poll(struct timer_list *unused)
+{
+	struct moxa_board_conf *brd;
+	u16 __iomem *ip;
+	unsigned int card, port, served = 0;
+
+	spin_lock(&moxa_lock);
+	for (card = 0; card < MAX_BOARDS; card++) {
+		brd = &moxa_boards[card];
+		if (!brd->ready)
+			continue;
+
+		served++;
+
+		ip = NULL;
+		if (readb(brd->intPend) == 0xff)
+			ip = brd->intTable + readb(brd->intNdx);
+
+		for (port = 0; port < brd->numPorts; port++)
+			moxa_poll_port(&brd->ports[port], !!ip, ip + port);
+
+		if (ip)
+			writeb(0, brd->intPend); /* ACK */
+
+		if (moxaLowWaterChk) {
+			struct moxa_port *p = brd->ports;
+			for (port = 0; port < brd->numPorts; port++, p++)
+				if (p->lowChkFlag) {
+					p->lowChkFlag = 0;
+					moxa_low_water_check(p->tableAddr);
+				}
+		}
+	}
+	moxaLowWaterChk = 0;
+
+	if (served)
+		mod_timer(&moxaTimer, jiffies + HZ / 50);
+	spin_unlock(&moxa_lock);
+}
+
+/******************************************************************************/
+
+static void moxa_set_tty_param(struct tty_struct *tty,
+			       const struct ktermios *old_termios)
+{
+	register struct ktermios *ts = &tty->termios;
+	struct moxa_port *ch = tty->driver_data;
+	int rts, cts, txflow, rxflow, xany, baud;
+
+	rts = cts = txflow = rxflow = xany = 0;
+	if (ts->c_cflag & CRTSCTS)
+		rts = cts = 1;
+	if (ts->c_iflag & IXON)
+		txflow = 1;
+	if (ts->c_iflag & IXOFF)
+		rxflow = 1;
+	if (ts->c_iflag & IXANY)
+		xany = 1;
+
+	MoxaPortFlowCtrl(ch, rts, cts, txflow, rxflow, xany);
+	baud = MoxaPortSetTermio(ch, ts, tty_get_baud_rate(tty));
+	if (baud == -1)
+		baud = tty_termios_baud_rate(old_termios);
+	/* Not put the baud rate into the termios data */
+	tty_encode_baud_rate(tty, baud, baud);
+}
+
+/*****************************************************************************
+ *	Driver level functions: 					     *
+ *****************************************************************************/
+
+static void MoxaPortFlushData(struct moxa_port *port, int mode)
+{
+	void __iomem *ofsAddr;
+	if (mode < 0 || mode > 2)
+		return;
+	ofsAddr = port->tableAddr;
+	moxafunc(ofsAddr, FC_FlushQueue, mode);
+	if (mode != 1) {
+		port->lowChkFlag = 0;
+		moxa_low_water_check(ofsAddr);
+	}
+}
+
+/*
+ *    Moxa Port Number Description:
+ *
+ *      MOXA serial driver supports up to 4 MOXA-C218/C320 boards. And,
+ *      the port number using in MOXA driver functions will be 0 to 31 for
+ *      first MOXA board, 32 to 63 for second, 64 to 95 for third and 96
+ *      to 127 for fourth. For example, if you setup three MOXA boards,
+ *      first board is C218, second board is C320-16 and third board is
+ *      C320-32. The port number of first board (C218 - 8 ports) is from
+ *      0 to 7. The port number of second board (C320 - 16 ports) is form
+ *      32 to 47. The port number of third board (C320 - 32 ports) is from
+ *      64 to 95. And those port numbers form 8 to 31, 48 to 63 and 96 to
+ *      127 will be invalid.
+ *
+ *
+ *      Moxa Functions Description:
+ *
+ *      Function 1:     Driver initialization routine, this routine must be
+ *                      called when initialized driver.
+ *      Syntax:
+ *      void MoxaDriverInit();
+ *
+ *
+ *      Function 2:     Moxa driver private IOCTL command processing.
+ *      Syntax:
+ *      int  MoxaDriverIoctl(unsigned int cmd, unsigned long arg, int port);
+ *
+ *           unsigned int cmd   : IOCTL command
+ *           unsigned long arg  : IOCTL argument
+ *           int port           : port number (0 - 127)
+ *
+ *           return:    0  (OK)
+ *                      -EINVAL
+ *                      -ENOIOCTLCMD
+ *
+ *
+ *      Function 6:     Enable this port to start Tx/Rx data.
+ *      Syntax:
+ *      void MoxaPortEnable(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *
+ *      Function 7:     Disable this port
+ *      Syntax:
+ *      void MoxaPortDisable(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *
+ *      Function 10:    Setting baud rate of this port.
+ *      Syntax:
+ *      speed_t MoxaPortSetBaud(int port, speed_t baud);
+ *           int port           : port number (0 - 127)
+ *           long baud          : baud rate (50 - 115200)
+ *
+ *           return:    0       : this port is invalid or baud < 50
+ *                      50 - 115200 : the real baud rate set to the port, if
+ *                                    the argument baud is large than maximun
+ *                                    available baud rate, the real setting
+ *                                    baud rate will be the maximun baud rate.
+ *
+ *
+ *      Function 12:    Configure the port.
+ *      Syntax:
+ *      int  MoxaPortSetTermio(int port, struct ktermios *termio, speed_t baud);
+ *           int port           : port number (0 - 127)
+ *           struct ktermios * termio : termio structure pointer
+ *	     speed_t baud	: baud rate
+ *
+ *           return:    -1      : this port is invalid or termio == NULL
+ *                      0       : setting O.K.
+ *
+ *
+ *      Function 13:    Get the DTR/RTS state of this port.
+ *      Syntax:
+ *      int  MoxaPortGetLineOut(int port, bool *dtrState, bool *rtsState);
+ *           int port           : port number (0 - 127)
+ *           bool * dtr_active  : pointer to bool to receive the current DTR
+ *                                state. (if NULL, this function will not
+ *                                write to this address)
+ *           bool * rts_active  : pointer to bool to receive the current RTS
+ *                                state. (if NULL, this function will not
+ *                                write to this address)
+ *
+ *           return:    -1      : this port is invalid
+ *                      0       : O.K.
+ *
+ *
+ *      Function 14:    Setting the DTR/RTS output state of this port.
+ *      Syntax:
+ *      void MoxaPortLineCtrl(int port, bool dtrState, bool rtsState);
+ *           int port           : port number (0 - 127)
+ *           bool dtr_active    : DTR output state
+ *           bool rts_active    : RTS output state
+ *
+ *
+ *      Function 15:    Setting the flow control of this port.
+ *      Syntax:
+ *      void MoxaPortFlowCtrl(int port, int rtsFlow, int ctsFlow, int rxFlow,
+ *                            int txFlow,int xany);
+ *           int port           : port number (0 - 127)
+ *           int rtsFlow        : H/W RTS flow control (0: no, 1: yes)
+ *           int ctsFlow        : H/W CTS flow control (0: no, 1: yes)
+ *           int rxFlow         : S/W Rx XON/XOFF flow control (0: no, 1: yes)
+ *           int txFlow         : S/W Tx XON/XOFF flow control (0: no, 1: yes)
+ *           int xany           : S/W XANY flow control (0: no, 1: yes)
+ *
+ *
+ *      Function 16:    Get ths line status of this port
+ *      Syntax:
+ *      int  MoxaPortLineStatus(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *           return:    Bit 0 - CTS state (0: off, 1: on)
+ *                      Bit 1 - DSR state (0: off, 1: on)
+ *                      Bit 2 - DCD state (0: off, 1: on)
+ *
+ *
+ *      Function 19:    Flush the Rx/Tx buffer data of this port.
+ *      Syntax:
+ *      void MoxaPortFlushData(int port, int mode);
+ *           int port           : port number (0 - 127)
+ *           int mode    
+ *                      0       : flush the Rx buffer 
+ *                      1       : flush the Tx buffer 
+ *                      2       : flush the Rx and Tx buffer 
+ *
+ *
+ *      Function 20:    Write data.
+ *      Syntax:
+ *      int  MoxaPortWriteData(int port, unsigned char * buffer, int length);
+ *           int port           : port number (0 - 127)
+ *           unsigned char * buffer     : pointer to write data buffer.
+ *           int length         : write data length
+ *
+ *           return:    0 - length      : real write data length
+ *
+ *
+ *      Function 21:    Read data.
+ *      Syntax:
+ *      int  MoxaPortReadData(int port, struct tty_struct *tty);
+ *           int port           : port number (0 - 127)
+ *	     struct tty_struct *tty : tty for data
+ *
+ *           return:    0 - length      : real read data length
+ *
+ *
+ *      Function 24:    Get the Tx buffer current queued data bytes
+ *      Syntax:
+ *      int  MoxaPortTxQueue(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *           return:    ..      : Tx buffer current queued data bytes
+ *
+ *
+ *      Function 25:    Get the Tx buffer current free space
+ *      Syntax:
+ *      int  MoxaPortTxFree(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *           return:    ..      : Tx buffer current free space
+ *
+ *
+ *      Function 26:    Get the Rx buffer current queued data bytes
+ *      Syntax:
+ *      int  MoxaPortRxQueue(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *           return:    ..      : Rx buffer current queued data bytes
+ *
+ *
+ *      Function 28:    Disable port data transmission.
+ *      Syntax:
+ *      void MoxaPortTxDisable(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *
+ *      Function 29:    Enable port data transmission.
+ *      Syntax:
+ *      void MoxaPortTxEnable(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *
+ *      Function 31:    Get the received BREAK signal count and reset it.
+ *      Syntax:
+ *      int  MoxaPortResetBrkCnt(int port);
+ *           int port           : port number (0 - 127)
+ *
+ *           return:    0 - ..  : BREAK signal count
+ *
+ *
+ */
+
+static void MoxaPortEnable(struct moxa_port *port)
+{
+	void __iomem *ofsAddr;
+	u16 lowwater = 512;
+
+	ofsAddr = port->tableAddr;
+	writew(lowwater, ofsAddr + Low_water);
+	if (MOXA_IS_320(port->board))
+		moxafunc(ofsAddr, FC_SetBreakIrq, 0);
+	else
+		writew(readw(ofsAddr + HostStat) | WakeupBreak,
+				ofsAddr + HostStat);
+
+	moxafunc(ofsAddr, FC_SetLineIrq, Magic_code);
+	moxafunc(ofsAddr, FC_FlushQueue, 2);
+
+	moxafunc(ofsAddr, FC_EnableCH, Magic_code);
+	MoxaPortLineStatus(port);
+}
+
+static void MoxaPortDisable(struct moxa_port *port)
+{
+	void __iomem *ofsAddr = port->tableAddr;
+
+	moxafunc(ofsAddr, FC_SetFlowCtl, 0);	/* disable flow control */
+	moxafunc(ofsAddr, FC_ClrLineIrq, Magic_code);
+	writew(0, ofsAddr + HostStat);
+	moxafunc(ofsAddr, FC_DisableCH, Magic_code);
+}
+
+static speed_t MoxaPortSetBaud(struct moxa_port *port, speed_t baud)
+{
+	void __iomem *ofsAddr = port->tableAddr;
+	unsigned int clock, val;
+	speed_t max;
+
+	max = MOXA_IS_320(port->board) ? 460800 : 921600;
+	if (baud < 50)
+		return 0;
+	if (baud > max)
+		baud = max;
+	clock = 921600;
+	val = clock / baud;
+	moxafunc(ofsAddr, FC_SetBaud, val);
+	baud = clock / val;
+	return baud;
+}
+
+static int MoxaPortSetTermio(struct moxa_port *port, struct ktermios *termio,
+		speed_t baud)
+{
+	void __iomem *ofsAddr;
+	tcflag_t mode = 0;
+
+	ofsAddr = port->tableAddr;
+
+	mode = termio->c_cflag & CSIZE;
+	if (mode == CS5)
+		mode = MX_CS5;
+	else if (mode == CS6)
+		mode = MX_CS6;
+	else if (mode == CS7)
+		mode = MX_CS7;
+	else if (mode == CS8)
+		mode = MX_CS8;
+
+	if (termio->c_cflag & CSTOPB) {
+		if (mode == MX_CS5)
+			mode |= MX_STOP15;
+		else
+			mode |= MX_STOP2;
+	} else
+		mode |= MX_STOP1;
+
+	if (termio->c_cflag & PARENB) {
+		if (termio->c_cflag & PARODD) {
+			if (termio->c_cflag & CMSPAR)
+				mode |= MX_PARMARK;
+			else
+				mode |= MX_PARODD;
+		} else {
+			if (termio->c_cflag & CMSPAR)
+				mode |= MX_PARSPACE;
+			else
+				mode |= MX_PAREVEN;
+		}
+	} else
+		mode |= MX_PARNONE;
+
+	moxafunc(ofsAddr, FC_SetDataMode, (u16)mode);
+
+	if (MOXA_IS_320(port->board) && baud >= 921600)
+		return -1;
+
+	baud = MoxaPortSetBaud(port, baud);
+
+	if (termio->c_iflag & (IXON | IXOFF | IXANY)) {
+	        spin_lock_irq(&moxafunc_lock);
+		writeb(termio->c_cc[VSTART], ofsAddr + FuncArg);
+		writeb(termio->c_cc[VSTOP], ofsAddr + FuncArg1);
+		writeb(FC_SetXonXoff, ofsAddr + FuncCode);
+		moxa_wait_finish(ofsAddr);
+		spin_unlock_irq(&moxafunc_lock);
+
+	}
+	return baud;
+}
+
+static int MoxaPortGetLineOut(struct moxa_port *port, bool *dtr_active,
+		bool *rts_active)
+{
+	if (dtr_active)
+		*dtr_active = port->lineCtrl & DTR_ON;
+	if (rts_active)
+		*rts_active = port->lineCtrl & RTS_ON;
+
+	return 0;
+}
+
+static void MoxaPortLineCtrl(struct moxa_port *port, bool dtr_active, bool rts_active)
+{
+	u8 mode = 0;
+
+	if (dtr_active)
+		mode |= DTR_ON;
+	if (rts_active)
+		mode |= RTS_ON;
+	port->lineCtrl = mode;
+	moxafunc(port->tableAddr, FC_LineControl, mode);
+}
+
+static void MoxaPortFlowCtrl(struct moxa_port *port, int rts, int cts,
+		int txflow, int rxflow, int txany)
+{
+	int mode = 0;
+
+	if (rts)
+		mode |= RTS_FlowCtl;
+	if (cts)
+		mode |= CTS_FlowCtl;
+	if (txflow)
+		mode |= Tx_FlowCtl;
+	if (rxflow)
+		mode |= Rx_FlowCtl;
+	if (txany)
+		mode |= IXM_IXANY;
+	moxafunc(port->tableAddr, FC_SetFlowCtl, mode);
+}
+
+static int MoxaPortLineStatus(struct moxa_port *port)
+{
+	void __iomem *ofsAddr;
+	int val;
+
+	ofsAddr = port->tableAddr;
+	if (MOXA_IS_320(port->board))
+		val = moxafuncret(ofsAddr, FC_LineStatus, 0);
+	else
+		val = readw(ofsAddr + FlagStat) >> 4;
+	val &= 0x0B;
+	if (val & 8)
+		val |= 4;
+	moxa_new_dcdstate(port, val & 8);
+	val &= 7;
+	return val;
+}
+
+static int MoxaPortWriteData(struct tty_struct *tty, const u8 *buffer, int len)
+{
+	struct moxa_port *port = tty->driver_data;
+	void __iomem *baseAddr, *ofsAddr, *ofs;
+	unsigned int c, total;
+	u16 head, tail, tx_mask, spage, epage;
+	u16 pageno, pageofs, bufhead;
+
+	ofsAddr = port->tableAddr;
+	baseAddr = port->board->basemem;
+	tx_mask = readw(ofsAddr + TX_mask);
+	spage = readw(ofsAddr + Page_txb);
+	epage = readw(ofsAddr + EndPage_txb);
+	tail = readw(ofsAddr + TXwptr);
+	head = readw(ofsAddr + TXrptr);
+	c = (head > tail) ? (head - tail - 1) : (head - tail + tx_mask);
+	if (c > len)
+		c = len;
+	moxaLog.txcnt[port->port.tty->index] += c;
+	total = c;
+	if (spage == epage) {
+		bufhead = readw(ofsAddr + Ofs_txb);
+		writew(spage, baseAddr + Control_reg);
+		while (c > 0) {
+			if (head > tail)
+				len = head - tail - 1;
+			else
+				len = tx_mask + 1 - tail;
+			len = (c > len) ? len : c;
+			ofs = baseAddr + DynPage_addr + bufhead + tail;
+			memcpy_toio(ofs, buffer, len);
+			buffer += len;
+			tail = (tail + len) & tx_mask;
+			c -= len;
+		}
+	} else {
+		pageno = spage + (tail >> 13);
+		pageofs = tail & Page_mask;
+		while (c > 0) {
+			len = Page_size - pageofs;
+			if (len > c)
+				len = c;
+			writeb(pageno, baseAddr + Control_reg);
+			ofs = baseAddr + DynPage_addr + pageofs;
+			memcpy_toio(ofs, buffer, len);
+			buffer += len;
+			if (++pageno == epage)
+				pageno = spage;
+			pageofs = 0;
+			c -= len;
+		}
+		tail = (tail + total) & tx_mask;
+	}
+	writew(tail, ofsAddr + TXwptr);
+	writeb(1, ofsAddr + CD180TXirq);	/* start to send */
+	return total;
+}
+
+static int MoxaPortReadData(struct moxa_port *port)
+{
+	struct tty_struct *tty = port->port.tty;
+	unsigned char *dst;
+	void __iomem *baseAddr, *ofsAddr, *ofs;
+	unsigned int count, len, total;
+	u16 tail, rx_mask, spage, epage;
+	u16 pageno, pageofs, bufhead, head;
+
+	ofsAddr = port->tableAddr;
+	baseAddr = port->board->basemem;
+	head = readw(ofsAddr + RXrptr);
+	tail = readw(ofsAddr + RXwptr);
+	rx_mask = readw(ofsAddr + RX_mask);
+	spage = readw(ofsAddr + Page_rxb);
+	epage = readw(ofsAddr + EndPage_rxb);
+	count = (tail >= head) ? (tail - head) : (tail - head + rx_mask + 1);
+	if (count == 0)
+		return 0;
+
+	total = count;
+	moxaLog.rxcnt[tty->index] += total;
+	if (spage == epage) {
+		bufhead = readw(ofsAddr + Ofs_rxb);
+		writew(spage, baseAddr + Control_reg);
+		while (count > 0) {
+			ofs = baseAddr + DynPage_addr + bufhead + head;
+			len = (tail >= head) ? (tail - head) :
+					(rx_mask + 1 - head);
+			len = tty_prepare_flip_string(&port->port, &dst,
+					min(len, count));
+			memcpy_fromio(dst, ofs, len);
+			head = (head + len) & rx_mask;
+			count -= len;
+		}
+	} else {
+		pageno = spage + (head >> 13);
+		pageofs = head & Page_mask;
+		while (count > 0) {
+			writew(pageno, baseAddr + Control_reg);
+			ofs = baseAddr + DynPage_addr + pageofs;
+			len = tty_prepare_flip_string(&port->port, &dst,
+					min(Page_size - pageofs, count));
+			memcpy_fromio(dst, ofs, len);
+
+			count -= len;
+			pageofs = (pageofs + len) & Page_mask;
+			if (pageofs == 0 && ++pageno == epage)
+				pageno = spage;
+		}
+		head = (head + total) & rx_mask;
+	}
+	writew(head, ofsAddr + RXrptr);
+	if (readb(ofsAddr + FlagStat) & Xoff_state) {
+		moxaLowWaterChk = 1;
+		port->lowChkFlag = 1;
+	}
+	return total;
+}
+
+
+static unsigned int MoxaPortTxQueue(struct moxa_port *port)
+{
+	void __iomem *ofsAddr = port->tableAddr;
+	u16 rptr, wptr, mask;
+
+	rptr = readw(ofsAddr + TXrptr);
+	wptr = readw(ofsAddr + TXwptr);
+	mask = readw(ofsAddr + TX_mask);
+	return (wptr - rptr) & mask;
+}
+
+static unsigned int MoxaPortTxFree(struct moxa_port *port)
+{
+	void __iomem *ofsAddr = port->tableAddr;
+	u16 rptr, wptr, mask;
+
+	rptr = readw(ofsAddr + TXrptr);
+	wptr = readw(ofsAddr + TXwptr);
+	mask = readw(ofsAddr + TX_mask);
+	return mask - ((wptr - rptr) & mask);
+}
+
+static int MoxaPortRxQueue(struct moxa_port *port)
+{
+	void __iomem *ofsAddr = port->tableAddr;
+	u16 rptr, wptr, mask;
+
+	rptr = readw(ofsAddr + RXrptr);
+	wptr = readw(ofsAddr + RXwptr);
+	mask = readw(ofsAddr + RX_mask);
+	return (wptr - rptr) & mask;
+}
+
+static void MoxaPortTxDisable(struct moxa_port *port)
+{
+	moxafunc(port->tableAddr, FC_SetXoffState, Magic_code);
+}
+
+static void MoxaPortTxEnable(struct moxa_port *port)
+{
+	moxafunc(port->tableAddr, FC_SetXonState, Magic_code);
+}
+
+static int moxa_get_serial_info(struct tty_struct *tty,
+		struct serial_struct *ss)
+{
+	struct moxa_port *info = tty->driver_data;
+
+	if (tty->index == MAX_PORTS)
+		return -EINVAL;
+	if (!info)
+		return -ENODEV;
+	mutex_lock(&info->port.mutex);
+	ss->type = info->type;
+	ss->line = info->port.tty->index;
+	ss->flags = info->port.flags;
+	ss->baud_base = 921600;
+	ss->close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
+	mutex_unlock(&info->port.mutex);
+	return 0;
+}
+
+
+static int moxa_set_serial_info(struct tty_struct *tty,
+		struct serial_struct *ss)
+{
+	struct moxa_port *info = tty->driver_data;
+	unsigned int close_delay;
+
+	if (tty->index == MAX_PORTS)
+		return -EINVAL;
+	if (!info)
+		return -ENODEV;
+
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
+
+	mutex_lock(&info->port.mutex);
+	if (!capable(CAP_SYS_ADMIN)) {
+		if (close_delay != info->port.close_delay ||
+		    ss->type != info->type ||
+		    ((ss->flags & ~ASYNC_USR_MASK) !=
+		     (info->port.flags & ~ASYNC_USR_MASK))) {
+			mutex_unlock(&info->port.mutex);
+			return -EPERM;
+		}
+	} else {
+		info->port.close_delay = close_delay;
+
+		MoxaSetFifo(info, ss->type == PORT_16550A);
+
+		info->type = ss->type;
+	}
+	mutex_unlock(&info->port.mutex);
+	return 0;
+}
+
+
+
+/*****************************************************************************
+ *	Static local functions: 					     *
+ *****************************************************************************/
+
+static void MoxaSetFifo(struct moxa_port *port, int enable)
+{
+	void __iomem *ofsAddr = port->tableAddr;
+
+	if (!enable) {
+		moxafunc(ofsAddr, FC_SetRxFIFOTrig, 0);
+		moxafunc(ofsAddr, FC_SetTxFIFOCnt, 1);
+	} else {
+		moxafunc(ofsAddr, FC_SetRxFIFOTrig, 3);
+		moxafunc(ofsAddr, FC_SetTxFIFOCnt, 16);
+	}
+}
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
new file mode 100644
index 000000000..10aa4ed38
--- /dev/null
+++ b/drivers/tty/mxser.c
@@ -0,0 +1,1939 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *          mxser.c  -- MOXA Smartio/Industio family multiport serial driver.
+ *
+ *      Copyright (C) 1999-2006  Moxa Technologies (support@moxa.com).
+ *	Copyright (C) 2006-2008  Jiri Slaby <jirislaby@gmail.com>
+ *
+ *      This code is loosely based on the 1.8 moxa driver which is based on
+ *	Linux serial driver, written by Linus Torvalds, Theodore T'so and
+ *	others.
+ *
+ *	Fed through a cleanup, indent and remove of non 2.6 code by Alan Cox
+ *	<alan@lxorguk.ukuu.org.uk>. The original 1.8 code is available on
+ *	www.moxa.com.
+ *	- Fixed x86_64 cleanness
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/ratelimit.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <linux/uaccess.h>
+
+/*
+ *	Semi-public control interfaces
+ */
+
+/*
+ *	MOXA ioctls
+ */
+
+#define MOXA			0x400
+#define MOXA_SET_OP_MODE	(MOXA + 66)
+#define MOXA_GET_OP_MODE	(MOXA + 67)
+
+#define RS232_MODE		0
+#define RS485_2WIRE_MODE	1
+#define RS422_MODE		2
+#define RS485_4WIRE_MODE	3
+#define OP_MODE_MASK		3
+
+/* --------------------------------------------------- */
+
+/*
+ * Follow just what Moxa Must chip defines.
+ *
+ * When LCR register (offset 0x03) is written the following value, the Must chip
+ * will enter enhanced mode. And a write to EFR (offset 0x02) bit 6,7 will
+ * change bank.
+ */
+#define MOXA_MUST_ENTER_ENHANCED	0xBF
+
+/* when enhanced mode is enabled, access to general bank register */
+#define MOXA_MUST_GDL_REGISTER		0x07
+#define MOXA_MUST_GDL_MASK		0x7F
+#define MOXA_MUST_GDL_HAS_BAD_DATA	0x80
+
+#define MOXA_MUST_LSR_RERR		0x80	/* error in receive FIFO */
+/* enhanced register bank select and enhanced mode setting register */
+/* This works only when LCR register equals to 0xBF */
+#define MOXA_MUST_EFR_REGISTER		0x02
+#define MOXA_MUST_EFR_EFRB_ENABLE	0x10 /* enhanced mode enable */
+/* enhanced register bank set 0, 1, 2 */
+#define MOXA_MUST_EFR_BANK0		0x00
+#define MOXA_MUST_EFR_BANK1		0x40
+#define MOXA_MUST_EFR_BANK2		0x80
+#define MOXA_MUST_EFR_BANK3		0xC0
+#define MOXA_MUST_EFR_BANK_MASK		0xC0
+
+/* set XON1 value register, when LCR=0xBF and change to bank0 */
+#define MOXA_MUST_XON1_REGISTER		0x04
+
+/* set XON2 value register, when LCR=0xBF and change to bank0 */
+#define MOXA_MUST_XON2_REGISTER		0x05
+
+/* set XOFF1 value register, when LCR=0xBF and change to bank0 */
+#define MOXA_MUST_XOFF1_REGISTER	0x06
+
+/* set XOFF2 value register, when LCR=0xBF and change to bank0 */
+#define MOXA_MUST_XOFF2_REGISTER	0x07
+
+#define MOXA_MUST_RBRTL_REGISTER	0x04
+#define MOXA_MUST_RBRTH_REGISTER	0x05
+#define MOXA_MUST_RBRTI_REGISTER	0x06
+#define MOXA_MUST_THRTL_REGISTER	0x07
+#define MOXA_MUST_ENUM_REGISTER		0x04
+#define MOXA_MUST_HWID_REGISTER		0x05
+#define MOXA_MUST_ECR_REGISTER		0x06
+#define MOXA_MUST_CSR_REGISTER		0x07
+
+#define MOXA_MUST_FCR_GDA_MODE_ENABLE	0x20 /* good data mode enable */
+#define MOXA_MUST_FCR_GDA_ONLY_ENABLE	0x10 /* only good data put into RxFIFO */
+
+#define MOXA_MUST_IER_ECTSI		0x80 /* enable CTS interrupt */
+#define MOXA_MUST_IER_ERTSI		0x40 /* enable RTS interrupt */
+#define MOXA_MUST_IER_XINT		0x20 /* enable Xon/Xoff interrupt */
+#define MOXA_MUST_IER_EGDAI		0x10 /* enable GDA interrupt */
+
+#define MOXA_MUST_RECV_ISR		(UART_IER_RDI | MOXA_MUST_IER_EGDAI)
+
+/* GDA interrupt pending */
+#define MOXA_MUST_IIR_GDA		0x1C
+#define MOXA_MUST_IIR_RDA		0x04
+#define MOXA_MUST_IIR_RTO		0x0C
+#define MOXA_MUST_IIR_LSR		0x06
+
+/* received Xon/Xoff or specical interrupt pending */
+#define MOXA_MUST_IIR_XSC		0x10
+
+/* RTS/CTS change state interrupt pending */
+#define MOXA_MUST_IIR_RTSCTS		0x20
+#define MOXA_MUST_IIR_MASK		0x3E
+
+#define MOXA_MUST_MCR_XON_FLAG		0x40
+#define MOXA_MUST_MCR_XON_ANY		0x80
+#define MOXA_MUST_MCR_TX_XON		0x08
+
+#define MOXA_MUST_EFR_SF_MASK		0x0F /* software flow control on chip mask value */
+#define MOXA_MUST_EFR_SF_TX1		0x08 /* send Xon1/Xoff1 */
+#define MOXA_MUST_EFR_SF_TX2		0x04 /* send Xon2/Xoff2 */
+#define MOXA_MUST_EFR_SF_TX12		0x0C /* send Xon1,Xon2/Xoff1,Xoff2 */
+#define MOXA_MUST_EFR_SF_TX_NO		0x00 /* don't send Xon/Xoff */
+#define MOXA_MUST_EFR_SF_TX_MASK	0x0C /* Tx software flow control mask */
+#define MOXA_MUST_EFR_SF_RX_NO		0x00 /* don't receive Xon/Xoff */
+#define MOXA_MUST_EFR_SF_RX1		0x02 /* receive Xon1/Xoff1 */
+#define MOXA_MUST_EFR_SF_RX2		0x01 /* receive Xon2/Xoff2 */
+#define MOXA_MUST_EFR_SF_RX12		0x03 /* receive Xon1,Xon2/Xoff1,Xoff2 */
+#define MOXA_MUST_EFR_SF_RX_MASK	0x03 /* Rx software flow control mask */
+
+#define	MXSERMAJOR	 174
+
+#define MXSER_BOARDS		4	/* Max. boards */
+#define MXSER_PORTS_PER_BOARD	8	/* Max. ports per board */
+#define MXSER_PORTS		(MXSER_BOARDS * MXSER_PORTS_PER_BOARD)
+#define MXSER_ISR_PASS_LIMIT	100
+
+#define WAKEUP_CHARS		256
+
+#define MXSER_BAUD_BASE		921600
+#define MXSER_CUSTOM_DIVISOR	(MXSER_BAUD_BASE * 16)
+
+#define PCI_DEVICE_ID_MOXA_RC7000	0x0001
+#define PCI_DEVICE_ID_MOXA_CP102	0x1020
+#define PCI_DEVICE_ID_MOXA_CP102UL	0x1021
+#define PCI_DEVICE_ID_MOXA_CP102U	0x1022
+#define PCI_DEVICE_ID_MOXA_CP102UF	0x1023
+#define PCI_DEVICE_ID_MOXA_C104		0x1040
+#define PCI_DEVICE_ID_MOXA_CP104U	0x1041
+#define PCI_DEVICE_ID_MOXA_CP104JU	0x1042
+#define PCI_DEVICE_ID_MOXA_CP104EL	0x1043
+#define PCI_DEVICE_ID_MOXA_POS104UL	0x1044
+#define PCI_DEVICE_ID_MOXA_CB108	0x1080
+#define PCI_DEVICE_ID_MOXA_CP112UL	0x1120
+#define PCI_DEVICE_ID_MOXA_CT114	0x1140
+#define PCI_DEVICE_ID_MOXA_CP114	0x1141
+#define PCI_DEVICE_ID_MOXA_CB114	0x1142
+#define PCI_DEVICE_ID_MOXA_CP114UL	0x1143
+#define PCI_DEVICE_ID_MOXA_CP118U	0x1180
+#define PCI_DEVICE_ID_MOXA_CP118EL	0x1181
+#define PCI_DEVICE_ID_MOXA_CP132	0x1320
+#define PCI_DEVICE_ID_MOXA_CP132U	0x1321
+#define PCI_DEVICE_ID_MOXA_CP134U	0x1340
+#define PCI_DEVICE_ID_MOXA_CB134I	0x1341
+#define PCI_DEVICE_ID_MOXA_CP138U	0x1380
+#define PCI_DEVICE_ID_MOXA_C168		0x1680
+#define PCI_DEVICE_ID_MOXA_CP168U	0x1681
+#define PCI_DEVICE_ID_MOXA_CP168EL	0x1682
+
+#define MXSER_NPORTS(ddata)		((ddata) & 0xffU)
+#define MXSER_HIGHBAUD			0x0100
+
+enum mxser_must_hwid {
+	MOXA_OTHER_UART		= 0x00,
+	MOXA_MUST_MU150_HWID	= 0x01,
+	MOXA_MUST_MU860_HWID	= 0x02,
+};
+
+static const struct {
+	u8 type;
+	u8 fifo_size;
+	u8 rx_high_water;
+	u8 rx_low_water;
+	speed_t max_baud;
+} Gpci_uart_info[] = {
+	{ MOXA_OTHER_UART,	 16, 14,  1, 921600 },
+	{ MOXA_MUST_MU150_HWID,	 64, 48, 16, 230400 },
+	{ MOXA_MUST_MU860_HWID, 128, 96, 32, 921600 }
+};
+#define UART_INFO_NUM	ARRAY_SIZE(Gpci_uart_info)
+
+
+/* driver_data correspond to the lines in the structure above
+   see also ISA probe function before you change something */
+static const struct pci_device_id mxser_pcibrds[] = {
+	{ PCI_DEVICE_DATA(MOXA, C168,		8) },
+	{ PCI_DEVICE_DATA(MOXA, C104,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP132,		2) },
+	{ PCI_DEVICE_DATA(MOXA, CP114,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CT114,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP102,		2 | MXSER_HIGHBAUD) },
+	{ PCI_DEVICE_DATA(MOXA, CP104U,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP168U,		8) },
+	{ PCI_DEVICE_DATA(MOXA, CP132U,		2) },
+	{ PCI_DEVICE_DATA(MOXA, CP134U,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP104JU,	4) },
+	{ PCI_DEVICE_DATA(MOXA, RC7000,		8) }, /* RC7000 */
+	{ PCI_DEVICE_DATA(MOXA, CP118U,		8) },
+	{ PCI_DEVICE_DATA(MOXA, CP102UL,	2) },
+	{ PCI_DEVICE_DATA(MOXA, CP102U,		2) },
+	{ PCI_DEVICE_DATA(MOXA, CP118EL,	8) },
+	{ PCI_DEVICE_DATA(MOXA, CP168EL,	8) },
+	{ PCI_DEVICE_DATA(MOXA, CP104EL,	4) },
+	{ PCI_DEVICE_DATA(MOXA, CB108,		8) },
+	{ PCI_DEVICE_DATA(MOXA, CB114,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CB134I,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP138U,		8) },
+	{ PCI_DEVICE_DATA(MOXA, POS104UL,	4) },
+	{ PCI_DEVICE_DATA(MOXA, CP114UL,	4) },
+	{ PCI_DEVICE_DATA(MOXA, CP102UF,	2) },
+	{ PCI_DEVICE_DATA(MOXA, CP112UL,	2) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, mxser_pcibrds);
+
+static int ttymajor = MXSERMAJOR;
+
+/* Variables for insmod */
+
+MODULE_AUTHOR("Casper Yang");
+MODULE_DESCRIPTION("MOXA Smartio/Industio Family Multiport Board Device Driver");
+module_param(ttymajor, int, 0);
+MODULE_LICENSE("GPL");
+
+struct mxser_board;
+
+struct mxser_port {
+	struct tty_port port;
+	struct mxser_board *board;
+
+	unsigned long ioaddr;
+	unsigned long opmode_ioaddr;
+
+	u8 rx_high_water;
+	u8 rx_low_water;
+	int type;		/* UART type */
+
+	unsigned char x_char;	/* xon/xoff character */
+	u8 IER;			/* Interrupt Enable Register */
+	u8 MCR;			/* Modem control register */
+	u8 FCR;			/* FIFO control register */
+
+	struct async_icount icount; /* kernel counters for 4 input interrupts */
+	unsigned int timeout;
+
+	u8 read_status_mask;
+	u8 ignore_status_mask;
+	u8 xmit_fifo_size;
+
+	spinlock_t slock;
+};
+
+struct mxser_board {
+	unsigned int idx;
+	unsigned short nports;
+	int irq;
+	unsigned long vector;
+
+	enum mxser_must_hwid must_hwid;
+	speed_t max_baud;
+
+	struct mxser_port ports[];
+};
+
+static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);
+static struct tty_driver *mxvar_sdriver;
+
+static u8 __mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set,
+		bool restore_LCR)
+{
+	u8 oldlcr, efr;
+
+	oldlcr = inb(baseio + UART_LCR);
+	outb(MOXA_MUST_ENTER_ENHANCED, baseio + UART_LCR);
+
+	efr = inb(baseio + MOXA_MUST_EFR_REGISTER);
+	efr &= ~clear;
+	efr |= set;
+
+	outb(efr, baseio + MOXA_MUST_EFR_REGISTER);
+
+	if (restore_LCR)
+		outb(oldlcr, baseio + UART_LCR);
+
+	return oldlcr;
+}
+
+static u8 mxser_must_select_bank(unsigned long baseio, u8 bank)
+{
+	return __mxser_must_set_EFR(baseio, MOXA_MUST_EFR_BANK_MASK, bank,
+			false);
+}
+
+static void mxser_set_must_xon1_value(unsigned long baseio, u8 value)
+{
+	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
+	outb(value, baseio + MOXA_MUST_XON1_REGISTER);
+	outb(oldlcr, baseio + UART_LCR);
+}
+
+static void mxser_set_must_xoff1_value(unsigned long baseio, u8 value)
+{
+	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
+	outb(value, baseio + MOXA_MUST_XOFF1_REGISTER);
+	outb(oldlcr, baseio + UART_LCR);
+}
+
+static void mxser_set_must_fifo_value(struct mxser_port *info)
+{
+	u8 oldlcr = mxser_must_select_bank(info->ioaddr, MOXA_MUST_EFR_BANK1);
+	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTH_REGISTER);
+	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTI_REGISTER);
+	outb(info->rx_low_water, info->ioaddr + MOXA_MUST_RBRTL_REGISTER);
+	outb(oldlcr, info->ioaddr + UART_LCR);
+}
+
+static void mxser_set_must_enum_value(unsigned long baseio, u8 value)
+{
+	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
+	outb(value, baseio + MOXA_MUST_ENUM_REGISTER);
+	outb(oldlcr, baseio + UART_LCR);
+}
+
+static u8 mxser_get_must_hardware_id(unsigned long baseio)
+{
+	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
+	u8 id = inb(baseio + MOXA_MUST_HWID_REGISTER);
+	outb(oldlcr, baseio + UART_LCR);
+
+	return id;
+}
+
+static void mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set)
+{
+	__mxser_must_set_EFR(baseio, clear, set, true);
+}
+
+static void mxser_must_set_enhance_mode(unsigned long baseio, bool enable)
+{
+	mxser_must_set_EFR(baseio,
+			enable ? 0 : MOXA_MUST_EFR_EFRB_ENABLE,
+			enable ? MOXA_MUST_EFR_EFRB_ENABLE : 0);
+}
+
+static void mxser_must_no_sw_flow_control(unsigned long baseio)
+{
+	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_MASK, 0);
+}
+
+static void mxser_must_set_tx_sw_flow_control(unsigned long baseio, bool enable)
+{
+	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_TX_MASK,
+			enable ? MOXA_MUST_EFR_SF_TX1 : 0);
+}
+
+static void mxser_must_set_rx_sw_flow_control(unsigned long baseio, bool enable)
+{
+	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_RX_MASK,
+			enable ? MOXA_MUST_EFR_SF_RX1 : 0);
+}
+
+static enum mxser_must_hwid mxser_must_get_hwid(unsigned long io)
+{
+	u8 oldmcr, hwid;
+	int i;
+
+	outb(0, io + UART_LCR);
+	mxser_must_set_enhance_mode(io, false);
+	oldmcr = inb(io + UART_MCR);
+	outb(0, io + UART_MCR);
+	mxser_set_must_xon1_value(io, 0x11);
+	if (inb(io + UART_MCR) != 0) {
+		outb(oldmcr, io + UART_MCR);
+		return MOXA_OTHER_UART;
+	}
+
+	hwid = mxser_get_must_hardware_id(io);
+	for (i = 1; i < UART_INFO_NUM; i++) /* 0 = OTHER_UART */
+		if (hwid == Gpci_uart_info[i].type)
+			return hwid;
+
+	return MOXA_OTHER_UART;
+}
+
+static bool mxser_16550A_or_MUST(struct mxser_port *info)
+{
+	return info->type == PORT_16550A || info->board->must_hwid;
+}
+
+static void mxser_process_txrx_fifo(struct mxser_port *info)
+{
+	unsigned int i;
+
+	if (info->type == PORT_16450 || info->type == PORT_8250) {
+		info->rx_high_water = 1;
+		info->rx_low_water = 1;
+		info->xmit_fifo_size = 1;
+		return;
+	}
+
+	for (i = 0; i < UART_INFO_NUM; i++)
+		if (info->board->must_hwid == Gpci_uart_info[i].type) {
+			info->rx_low_water = Gpci_uart_info[i].rx_low_water;
+			info->rx_high_water = Gpci_uart_info[i].rx_high_water;
+			info->xmit_fifo_size = Gpci_uart_info[i].fifo_size;
+			break;
+		}
+}
+
+static void __mxser_start_tx(struct mxser_port *info)
+{
+	outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
+	info->IER |= UART_IER_THRI;
+	outb(info->IER, info->ioaddr + UART_IER);
+}
+
+static void mxser_start_tx(struct mxser_port *info)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	__mxser_start_tx(info);
+	spin_unlock_irqrestore(&info->slock, flags);
+}
+
+static void __mxser_stop_tx(struct mxser_port *info)
+{
+	info->IER &= ~UART_IER_THRI;
+	outb(info->IER, info->ioaddr + UART_IER);
+}
+
+static bool mxser_carrier_raised(struct tty_port *port)
+{
+	struct mxser_port *mp = container_of(port, struct mxser_port, port);
+
+	return inb(mp->ioaddr + UART_MSR) & UART_MSR_DCD;
+}
+
+static void mxser_dtr_rts(struct tty_port *port, bool active)
+{
+	struct mxser_port *mp = container_of(port, struct mxser_port, port);
+	unsigned long flags;
+	u8 mcr;
+
+	spin_lock_irqsave(&mp->slock, flags);
+	mcr = inb(mp->ioaddr + UART_MCR);
+	if (active)
+		mcr |= UART_MCR_DTR | UART_MCR_RTS;
+	else
+		mcr &= ~(UART_MCR_DTR | UART_MCR_RTS);
+	outb(mcr, mp->ioaddr + UART_MCR);
+	spin_unlock_irqrestore(&mp->slock, flags);
+}
+
+static int mxser_set_baud(struct tty_struct *tty, speed_t newspd)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned int quot = 0, baud;
+	unsigned char cval;
+	u64 timeout;
+
+	if (newspd > info->board->max_baud)
+		return -1;
+
+	if (newspd == 134) {
+		quot = 2 * MXSER_BAUD_BASE / 269;
+		tty_encode_baud_rate(tty, 134, 134);
+	} else if (newspd) {
+		quot = MXSER_BAUD_BASE / newspd;
+		if (quot == 0)
+			quot = 1;
+		baud = MXSER_BAUD_BASE / quot;
+		tty_encode_baud_rate(tty, baud, baud);
+	} else {
+		quot = 0;
+	}
+
+	/*
+	 * worst case (128 * 1000 * 10 * 18432) needs 35 bits, so divide in the
+	 * u64 domain
+	 */
+	timeout = (u64)info->xmit_fifo_size * HZ * 10 * quot;
+	do_div(timeout, MXSER_BAUD_BASE);
+	info->timeout = timeout + HZ / 50; /* Add .02 seconds of slop */
+
+	if (quot) {
+		info->MCR |= UART_MCR_DTR;
+		outb(info->MCR, info->ioaddr + UART_MCR);
+	} else {
+		info->MCR &= ~UART_MCR_DTR;
+		outb(info->MCR, info->ioaddr + UART_MCR);
+		return 0;
+	}
+
+	cval = inb(info->ioaddr + UART_LCR);
+
+	outb(cval | UART_LCR_DLAB, info->ioaddr + UART_LCR);	/* set DLAB */
+
+	outb(quot & 0xff, info->ioaddr + UART_DLL);	/* LS of divisor */
+	outb(quot >> 8, info->ioaddr + UART_DLM);	/* MS of divisor */
+	outb(cval, info->ioaddr + UART_LCR);	/* reset DLAB */
+
+	if (C_BAUD(tty) == BOTHER) {
+		quot = MXSER_BAUD_BASE % newspd;
+		quot *= 8;
+		if (quot % newspd > newspd / 2) {
+			quot /= newspd;
+			quot++;
+		} else
+			quot /= newspd;
+
+		mxser_set_must_enum_value(info->ioaddr, quot);
+	} else {
+		mxser_set_must_enum_value(info->ioaddr, 0);
+	}
+
+	return 0;
+}
+
+static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
+		u8 msr)
+{
+	bool cts = msr & UART_MSR_CTS;
+
+	if (tty->hw_stopped) {
+		if (cts) {
+			tty->hw_stopped = false;
+
+			if (!mxser_16550A_or_MUST(info))
+				__mxser_start_tx(info);
+			tty_wakeup(tty);
+		}
+		return;
+	} else if (cts)
+		return;
+
+	tty->hw_stopped = true;
+	if (!mxser_16550A_or_MUST(info))
+		__mxser_stop_tx(info);
+}
+
+/*
+ * This routine is called to set the UART divisor registers to match
+ * the specified baud rate for a serial port.
+ */
+static void mxser_change_speed(struct tty_struct *tty,
+			       const struct ktermios *old_termios)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned cflag, cval;
+
+	cflag = tty->termios.c_cflag;
+
+	if (mxser_set_baud(tty, tty_get_baud_rate(tty))) {
+		/* Use previous rate on a failure */
+		if (old_termios) {
+			speed_t baud = tty_termios_baud_rate(old_termios);
+			tty_encode_baud_rate(tty, baud, baud);
+		}
+	}
+
+	/* byte size and parity */
+	cval = UART_LCR_WLEN(tty_get_char_size(tty->termios.c_cflag));
+
+	if (cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	if (cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+
+	info->FCR = 0;
+	if (info->board->must_hwid) {
+		info->FCR |= UART_FCR_ENABLE_FIFO |
+			MOXA_MUST_FCR_GDA_MODE_ENABLE;
+		mxser_set_must_fifo_value(info);
+	} else if (info->type != PORT_8250 && info->type != PORT_16450) {
+		info->FCR |= UART_FCR_ENABLE_FIFO;
+		switch (info->rx_high_water) {
+		case 1:
+			info->FCR |= UART_FCR_TRIGGER_1;
+			break;
+		case 4:
+			info->FCR |= UART_FCR_TRIGGER_4;
+			break;
+		case 8:
+			info->FCR |= UART_FCR_TRIGGER_8;
+			break;
+		default:
+			info->FCR |= UART_FCR_TRIGGER_14;
+			break;
+		}
+	}
+
+	/* CTS flow control flag and modem status interrupts */
+	info->IER &= ~UART_IER_MSI;
+	info->MCR &= ~UART_MCR_AFE;
+	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
+	if (cflag & CRTSCTS) {
+		info->IER |= UART_IER_MSI;
+		if (mxser_16550A_or_MUST(info)) {
+			info->MCR |= UART_MCR_AFE;
+		} else {
+			mxser_handle_cts(tty, info,
+					inb(info->ioaddr + UART_MSR));
+		}
+	}
+	outb(info->MCR, info->ioaddr + UART_MCR);
+	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
+	if (~cflag & CLOCAL)
+		info->IER |= UART_IER_MSI;
+	outb(info->IER, info->ioaddr + UART_IER);
+
+	/*
+	 * Set up parity check flag
+	 */
+	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (I_INPCK(tty))
+		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (I_BRKINT(tty) || I_PARMRK(tty))
+		info->read_status_mask |= UART_LSR_BI;
+
+	info->ignore_status_mask = 0;
+
+	if (I_IGNBRK(tty)) {
+		info->ignore_status_mask |= UART_LSR_BI;
+		info->read_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignore parity and break indicators, ignore
+		 * overruns too.  (For real raw support).
+		 */
+		if (I_IGNPAR(tty)) {
+			info->ignore_status_mask |=
+						UART_LSR_OE |
+						UART_LSR_PE |
+						UART_LSR_FE;
+			info->read_status_mask |=
+						UART_LSR_OE |
+						UART_LSR_PE |
+						UART_LSR_FE;
+		}
+	}
+	if (info->board->must_hwid) {
+		mxser_set_must_xon1_value(info->ioaddr, START_CHAR(tty));
+		mxser_set_must_xoff1_value(info->ioaddr, STOP_CHAR(tty));
+		mxser_must_set_rx_sw_flow_control(info->ioaddr, I_IXON(tty));
+		mxser_must_set_tx_sw_flow_control(info->ioaddr, I_IXOFF(tty));
+	}
+
+
+	outb(info->FCR, info->ioaddr + UART_FCR);
+	outb(cval, info->ioaddr + UART_LCR);
+}
+
+static u8 mxser_check_modem_status(struct tty_struct *tty,
+				struct mxser_port *port)
+{
+	u8 msr = inb(port->ioaddr + UART_MSR);
+
+	if (!(msr & UART_MSR_ANY_DELTA))
+		return msr;
+
+	/* update input line counters */
+	if (msr & UART_MSR_TERI)
+		port->icount.rng++;
+	if (msr & UART_MSR_DDSR)
+		port->icount.dsr++;
+	if (msr & UART_MSR_DDCD)
+		port->icount.dcd++;
+	if (msr & UART_MSR_DCTS)
+		port->icount.cts++;
+	wake_up_interruptible(&port->port.delta_msr_wait);
+
+	if (tty_port_check_carrier(&port->port) && (msr & UART_MSR_DDCD)) {
+		if (msr & UART_MSR_DCD)
+			wake_up_interruptible(&port->port.open_wait);
+	}
+
+	if (tty_port_cts_enabled(&port->port))
+		mxser_handle_cts(tty, port, msr);
+
+	return msr;
+}
+
+static void mxser_disable_and_clear_FIFO(struct mxser_port *info)
+{
+	u8 fcr = UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT;
+
+	if (info->board->must_hwid)
+		fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
+
+	outb(fcr, info->ioaddr + UART_FCR);
+}
+
+static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct mxser_port *info = container_of(port, struct mxser_port, port);
+	unsigned long flags;
+	int ret;
+
+	ret = tty_port_alloc_xmit_buf(port);
+	if (ret < 0)
+		return ret;
+
+	spin_lock_irqsave(&info->slock, flags);
+
+	if (!info->type) {
+		set_bit(TTY_IO_ERROR, &tty->flags);
+		spin_unlock_irqrestore(&info->slock, flags);
+		ret = 0;
+		goto err_free_xmit;
+	}
+
+	/*
+	 * Clear the FIFO buffers and disable them
+	 * (they will be reenabled in mxser_change_speed())
+	 */
+	mxser_disable_and_clear_FIFO(info);
+
+	/*
+	 * At this point there's no way the LSR could still be 0xFF;
+	 * if it is, then bail out, because there's likely no UART
+	 * here.
+	 */
+	if (inb(info->ioaddr + UART_LSR) == 0xff) {
+		spin_unlock_irqrestore(&info->slock, flags);
+		if (capable(CAP_SYS_ADMIN)) {
+			set_bit(TTY_IO_ERROR, &tty->flags);
+			return 0;
+		}
+
+		ret = -ENODEV;
+		goto err_free_xmit;
+	}
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) inb(info->ioaddr + UART_LSR);
+	(void) inb(info->ioaddr + UART_RX);
+	(void) inb(info->ioaddr + UART_IIR);
+	(void) inb(info->ioaddr + UART_MSR);
+
+	/*
+	 * Now, initialize the UART
+	 */
+	outb(UART_LCR_WLEN8, info->ioaddr + UART_LCR);	/* reset DLAB */
+	info->MCR = UART_MCR_DTR | UART_MCR_RTS;
+	outb(info->MCR, info->ioaddr + UART_MCR);
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
+
+	if (info->board->must_hwid)
+		info->IER |= MOXA_MUST_IER_EGDAI;
+	outb(info->IER, info->ioaddr + UART_IER);	/* enable interrupts */
+
+	/*
+	 * And clear the interrupt registers again for luck.
+	 */
+	(void) inb(info->ioaddr + UART_LSR);
+	(void) inb(info->ioaddr + UART_RX);
+	(void) inb(info->ioaddr + UART_IIR);
+	(void) inb(info->ioaddr + UART_MSR);
+
+	clear_bit(TTY_IO_ERROR, &tty->flags);
+	kfifo_reset(&port->xmit_fifo);
+
+	/*
+	 * and set the speed of the serial port
+	 */
+	mxser_change_speed(tty, NULL);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	return 0;
+err_free_xmit:
+	tty_port_free_xmit_buf(port);
+	return ret;
+}
+
+/*
+ * To stop accepting input, we disable the receive line status interrupts, and
+ * tell the interrupt driver to stop checking the data ready bit in the line
+ * status register.
+ */
+static void mxser_stop_rx(struct mxser_port *info)
+{
+	info->IER &= ~UART_IER_RLSI;
+	if (info->board->must_hwid)
+		info->IER &= ~MOXA_MUST_RECV_ISR;
+
+	outb(info->IER, info->ioaddr + UART_IER);
+}
+
+/*
+ * This routine will shutdown a serial port
+ */
+static void mxser_shutdown_port(struct tty_port *port)
+{
+	struct mxser_port *info = container_of(port, struct mxser_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+
+	mxser_stop_rx(info);
+
+	/*
+	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
+	 * here so the queue might never be waken up
+	 */
+	wake_up_interruptible(&info->port.delta_msr_wait);
+
+	info->IER = 0;
+	outb(0x00, info->ioaddr + UART_IER);
+
+	/* clear Rx/Tx FIFO's */
+	mxser_disable_and_clear_FIFO(info);
+
+	/* read data port to reset things */
+	(void) inb(info->ioaddr + UART_RX);
+
+
+	if (info->board->must_hwid)
+		mxser_must_no_sw_flow_control(info->ioaddr);
+
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	/* make sure ISR is not running while we free the buffer */
+	synchronize_irq(info->board->irq);
+
+	tty_port_free_xmit_buf(port);
+}
+
+/*
+ * This routine is called whenever a serial port is opened.  It
+ * enables interrupts for a serial port, linking in its async structure into
+ * the IRQ chain.   It also performs the serial-specific
+ * initialization for the tty structure.
+ */
+static int mxser_open(struct tty_struct *tty, struct file *filp)
+{
+	struct tty_port *tport = tty->port;
+	struct mxser_port *port = container_of(tport, struct mxser_port, port);
+
+	tty->driver_data = port;
+
+	return tty_port_open(tport, tty, filp);
+}
+
+static void mxser_flush_buffer(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	kfifo_reset(&info->port.xmit_fifo);
+
+	outb(info->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+		info->ioaddr + UART_FCR);
+
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	tty_wakeup(tty);
+}
+
+static void mxser_close(struct tty_struct *tty, struct file *filp)
+{
+	tty_port_close(tty->port, tty, filp);
+}
+
+static ssize_t mxser_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+	int written;
+	bool is_empty;
+
+	spin_lock_irqsave(&info->slock, flags);
+	written = kfifo_in(&info->port.xmit_fifo, buf, count);
+	is_empty = kfifo_is_empty(&info->port.xmit_fifo);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	if (!is_empty && !tty->flow.stopped)
+		if (!tty->hw_stopped || mxser_16550A_or_MUST(info))
+			mxser_start_tx(info);
+
+	return written;
+}
+
+static int mxser_put_char(struct tty_struct *tty, u8 ch)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&info->slock, flags);
+	ret = kfifo_put(&info->port.xmit_fifo, ch);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	return ret;
+}
+
+
+static void mxser_flush_chars(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+
+	if (kfifo_is_empty(&info->port.xmit_fifo) || tty->flow.stopped ||
+			(tty->hw_stopped && !mxser_16550A_or_MUST(info)))
+		return;
+
+	mxser_start_tx(info);
+}
+
+static unsigned int mxser_write_room(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+
+	return kfifo_avail(&info->port.xmit_fifo);
+}
+
+static unsigned int mxser_chars_in_buffer(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+
+	return kfifo_len(&info->port.xmit_fifo);
+}
+
+/*
+ * ------------------------------------------------------------
+ * friends of mxser_ioctl()
+ * ------------------------------------------------------------
+ */
+static int mxser_get_serial_info(struct tty_struct *tty,
+		struct serial_struct *ss)
+{
+	struct mxser_port *info = tty->driver_data;
+	struct tty_port *port = &info->port;
+	unsigned int closing_wait, close_delay;
+
+	mutex_lock(&port->mutex);
+
+	close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
+	closing_wait = info->port.closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = jiffies_to_msecs(closing_wait) / 10;
+
+	ss->type = info->type;
+	ss->line = tty->index;
+	ss->port = info->ioaddr;
+	ss->irq = info->board->irq;
+	ss->flags = info->port.flags;
+	ss->baud_base = MXSER_BAUD_BASE;
+	ss->close_delay = close_delay;
+	ss->closing_wait = closing_wait;
+	ss->custom_divisor = MXSER_CUSTOM_DIVISOR,
+	mutex_unlock(&port->mutex);
+	return 0;
+}
+
+static int mxser_set_serial_info(struct tty_struct *tty,
+		struct serial_struct *ss)
+{
+	struct mxser_port *info = tty->driver_data;
+	struct tty_port *port = &info->port;
+	speed_t baud;
+	unsigned long sl_flags;
+	unsigned int old_speed, close_delay, closing_wait;
+	int retval = 0;
+
+	if (tty_io_error(tty))
+		return -EIO;
+
+	mutex_lock(&port->mutex);
+
+	if (ss->irq != info->board->irq ||
+			ss->port != info->ioaddr) {
+		mutex_unlock(&port->mutex);
+		return -EINVAL;
+	}
+
+	old_speed = port->flags & ASYNC_SPD_MASK;
+
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
+	closing_wait = ss->closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = msecs_to_jiffies(closing_wait * 10);
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		if ((ss->baud_base != MXSER_BAUD_BASE) ||
+				(close_delay != port->close_delay) ||
+				(closing_wait != port->closing_wait) ||
+				((ss->flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK))) {
+			mutex_unlock(&port->mutex);
+			return -EPERM;
+		}
+		port->flags = (port->flags & ~ASYNC_USR_MASK) |
+				(ss->flags & ASYNC_USR_MASK);
+	} else {
+		/*
+		 * OK, past this point, all the error checking has been done.
+		 * At this point, we start making changes.....
+		 */
+		port->flags = ((port->flags & ~ASYNC_FLAGS) |
+				(ss->flags & ASYNC_FLAGS));
+		port->close_delay = close_delay;
+		port->closing_wait = closing_wait;
+		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
+				(ss->baud_base != MXSER_BAUD_BASE ||
+				ss->custom_divisor !=
+				MXSER_CUSTOM_DIVISOR)) {
+			if (ss->custom_divisor == 0) {
+				mutex_unlock(&port->mutex);
+				return -EINVAL;
+			}
+			baud = ss->baud_base / ss->custom_divisor;
+			tty_encode_baud_rate(tty, baud, baud);
+		}
+
+		info->type = ss->type;
+
+		mxser_process_txrx_fifo(info);
+	}
+
+	if (tty_port_initialized(port)) {
+		if (old_speed != (port->flags & ASYNC_SPD_MASK)) {
+			spin_lock_irqsave(&info->slock, sl_flags);
+			mxser_change_speed(tty, NULL);
+			spin_unlock_irqrestore(&info->slock, sl_flags);
+		}
+	} else {
+		retval = mxser_activate(port, tty);
+		if (retval == 0)
+			tty_port_set_initialized(port, true);
+	}
+	mutex_unlock(&port->mutex);
+	return retval;
+}
+
+/*
+ * mxser_get_lsr_info - get line status register info
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ *	    is emptied.  On bus types like RS485, the transmitter must
+ *	    release the bus after transmitting. This must be done when
+ *	    the transmit shift register is empty, not be done when the
+ *	    transmit holding register is empty.  This functionality
+ *	    allows an RS485 driver to be written in user space.
+ */
+static int mxser_get_lsr_info(struct mxser_port *info,
+		unsigned int __user *value)
+{
+	unsigned char status;
+	unsigned int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	status = inb(info->ioaddr + UART_LSR);
+	spin_unlock_irqrestore(&info->slock, flags);
+	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
+	return put_user(result, value);
+}
+
+static int mxser_tiocmget(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned char control;
+	unsigned long flags;
+	u8 msr;
+
+	if (tty_io_error(tty))
+		return -EIO;
+
+	spin_lock_irqsave(&info->slock, flags);
+	control = info->MCR;
+	msr = mxser_check_modem_status(tty, info);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |
+		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
+		    ((msr & UART_MSR_DCD) ? TIOCM_CAR : 0) |
+		    ((msr & UART_MSR_RI) ? TIOCM_RNG : 0) |
+		    ((msr & UART_MSR_DSR) ? TIOCM_DSR : 0) |
+		    ((msr & UART_MSR_CTS) ? TIOCM_CTS : 0);
+}
+
+static int mxser_tiocmset(struct tty_struct *tty,
+		unsigned int set, unsigned int clear)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+
+	if (tty_io_error(tty))
+		return -EIO;
+
+	spin_lock_irqsave(&info->slock, flags);
+
+	if (set & TIOCM_RTS)
+		info->MCR |= UART_MCR_RTS;
+	if (set & TIOCM_DTR)
+		info->MCR |= UART_MCR_DTR;
+
+	if (clear & TIOCM_RTS)
+		info->MCR &= ~UART_MCR_RTS;
+	if (clear & TIOCM_DTR)
+		info->MCR &= ~UART_MCR_DTR;
+
+	outb(info->MCR, info->ioaddr + UART_MCR);
+	spin_unlock_irqrestore(&info->slock, flags);
+	return 0;
+}
+
+static int mxser_cflags_changed(struct mxser_port *info, unsigned long arg,
+		struct async_icount *cprev)
+{
+	struct async_icount cnow;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&info->slock, flags);
+	cnow = info->icount;	/* atomic copy */
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	ret =	((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
+		((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
+		((arg & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||
+		((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
+
+	*cprev = cnow;
+
+	return ret;
+}
+
+/* We should likely switch to TIOCGRS485/TIOCSRS485. */
+static int mxser_ioctl_op_mode(struct mxser_port *port, int index, bool set,
+		int __user *u_opmode)
+{
+	int opmode, p = index % 4;
+	int shiftbit = p * 2;
+	u8 val;
+
+	if (port->board->must_hwid != MOXA_MUST_MU860_HWID)
+		return -EFAULT;
+
+	if (set) {
+		if (get_user(opmode, u_opmode))
+			return -EFAULT;
+
+		if (opmode & ~OP_MODE_MASK)
+			return -EINVAL;
+
+		spin_lock_irq(&port->slock);
+		val = inb(port->opmode_ioaddr);
+		val &= ~(OP_MODE_MASK << shiftbit);
+		val |= (opmode << shiftbit);
+		outb(val, port->opmode_ioaddr);
+		spin_unlock_irq(&port->slock);
+
+		return 0;
+	}
+
+	spin_lock_irq(&port->slock);
+	opmode = inb(port->opmode_ioaddr) >> shiftbit;
+	spin_unlock_irq(&port->slock);
+
+	return put_user(opmode & OP_MODE_MASK, u_opmode);
+}
+
+static int mxser_ioctl(struct tty_struct *tty,
+		unsigned int cmd, unsigned long arg)
+{
+	struct mxser_port *info = tty->driver_data;
+	struct async_icount cnow;
+	unsigned long flags;
+	void __user *argp = (void __user *)arg;
+
+	if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE)
+		return mxser_ioctl_op_mode(info, tty->index,
+				cmd == MOXA_SET_OP_MODE, argp);
+
+	if (cmd != TIOCMIWAIT && tty_io_error(tty))
+		return -EIO;
+
+	switch (cmd) {
+	case TIOCSERGETLSR:	/* Get line status register */
+		return  mxser_get_lsr_info(info, argp);
+		/*
+		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
+		 * - mask passed in arg for lines of interest
+		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
+		 * Caller should use TIOCGICOUNT to see which one it was
+		 */
+	case TIOCMIWAIT:
+		spin_lock_irqsave(&info->slock, flags);
+		cnow = info->icount;	/* note the counters on entry */
+		spin_unlock_irqrestore(&info->slock, flags);
+
+		return wait_event_interruptible(info->port.delta_msr_wait,
+				mxser_cflags_changed(info, arg, &cnow));
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+	/*
+	 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
+	 * Return: write counters to the user passed counter struct
+	 * NB: both 1->0 and 0->1 transitions are counted except for
+	 *     RI where only 0->1 is counted.
+	 */
+
+static int mxser_get_icount(struct tty_struct *tty,
+		struct serial_icounter_struct *icount)
+
+{
+	struct mxser_port *info = tty->driver_data;
+	struct async_icount cnow;
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	cnow = info->icount;
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	icount->frame = cnow.frame;
+	icount->brk = cnow.brk;
+	icount->overrun = cnow.overrun;
+	icount->buf_overrun = cnow.buf_overrun;
+	icount->parity = cnow.parity;
+	icount->rx = cnow.rx;
+	icount->tx = cnow.tx;
+	icount->cts = cnow.cts;
+	icount->dsr = cnow.dsr;
+	icount->rng = cnow.rng;
+	icount->dcd = cnow.dcd;
+	return 0;
+}
+
+/*
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ */
+static void mxser_throttle(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+
+	if (I_IXOFF(tty)) {
+		if (info->board->must_hwid) {
+			info->IER &= ~MOXA_MUST_RECV_ISR;
+			outb(info->IER, info->ioaddr + UART_IER);
+		} else {
+			info->x_char = STOP_CHAR(tty);
+			outb(0, info->ioaddr + UART_IER);
+			info->IER |= UART_IER_THRI;
+			outb(info->IER, info->ioaddr + UART_IER);
+		}
+	}
+
+	if (C_CRTSCTS(tty)) {
+		info->MCR &= ~UART_MCR_RTS;
+		outb(info->MCR, info->ioaddr + UART_MCR);
+	}
+}
+
+static void mxser_unthrottle(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+
+	/* startrx */
+	if (I_IXOFF(tty)) {
+		if (info->x_char)
+			info->x_char = 0;
+		else {
+			if (info->board->must_hwid) {
+				info->IER |= MOXA_MUST_RECV_ISR;
+				outb(info->IER, info->ioaddr + UART_IER);
+			} else {
+				info->x_char = START_CHAR(tty);
+				outb(0, info->ioaddr + UART_IER);
+				info->IER |= UART_IER_THRI;
+				outb(info->IER, info->ioaddr + UART_IER);
+			}
+		}
+	}
+
+	if (C_CRTSCTS(tty)) {
+		info->MCR |= UART_MCR_RTS;
+		outb(info->MCR, info->ioaddr + UART_MCR);
+	}
+}
+
+/*
+ * mxser_stop() and mxser_start()
+ *
+ * This routines are called before setting or resetting tty->flow.stopped.
+ * They enable or disable transmitter interrupts, as necessary.
+ */
+static void mxser_stop(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	if (info->IER & UART_IER_THRI)
+		__mxser_stop_tx(info);
+	spin_unlock_irqrestore(&info->slock, flags);
+}
+
+static void mxser_start(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	if (!kfifo_is_empty(&info->port.xmit_fifo))
+		__mxser_start_tx(info);
+	spin_unlock_irqrestore(&info->slock, flags);
+}
+
+static void mxser_set_termios(struct tty_struct *tty,
+			      const struct ktermios *old_termios)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->slock, flags);
+	mxser_change_speed(tty, old_termios);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
+		tty->hw_stopped = false;
+		mxser_start(tty);
+	}
+
+	/* Handle sw stopped */
+	if ((old_termios->c_iflag & IXON) && !I_IXON(tty)) {
+		tty->flow.stopped = 0;
+
+		if (info->board->must_hwid) {
+			spin_lock_irqsave(&info->slock, flags);
+			mxser_must_set_rx_sw_flow_control(info->ioaddr, false);
+			spin_unlock_irqrestore(&info->slock, flags);
+		}
+
+		mxser_start(tty);
+	}
+}
+
+static bool mxser_tx_empty(struct mxser_port *info)
+{
+	unsigned long flags;
+	u8 lsr;
+
+	spin_lock_irqsave(&info->slock, flags);
+	lsr = inb(info->ioaddr + UART_LSR);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	return !(lsr & UART_LSR_TEMT);
+}
+
+/*
+ * mxser_wait_until_sent() --- wait until the transmitter is empty
+ */
+static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long expire, char_time;
+
+	if (info->type == PORT_UNKNOWN)
+		return;
+
+	if (info->xmit_fifo_size == 0)
+		return;		/* Just in case.... */
+
+	/*
+	 * Set the check interval to be 1/5 of the estimated time to
+	 * send a single character, and make it at least 1.  The check
+	 * interval should also be less than the timeout.
+	 *
+	 * Note: we have to use pretty tight timings here to satisfy
+	 * the NIST-PCTS.
+	 */
+	char_time = (info->timeout - HZ / 50) / info->xmit_fifo_size;
+	char_time = char_time / 5;
+	if (char_time == 0)
+		char_time = 1;
+	if (timeout && timeout < char_time)
+		char_time = timeout;
+
+	char_time = jiffies_to_msecs(char_time);
+
+	/*
+	 * If the transmitter hasn't cleared in twice the approximate
+	 * amount of time to send the entire FIFO, it probably won't
+	 * ever clear.  This assumes the UART isn't doing flow
+	 * control, which is currently the case.  Hence, if it ever
+	 * takes longer than info->timeout, this is probably due to a
+	 * UART bug of some kind.  So, we clamp the timeout parameter at
+	 * 2*info->timeout.
+	 */
+	if (!timeout || timeout > 2 * info->timeout)
+		timeout = 2 * info->timeout;
+
+	expire = jiffies + timeout;
+
+	while (mxser_tx_empty(info)) {
+		msleep_interruptible(char_time);
+		if (signal_pending(current))
+			break;
+		if (time_after(jiffies, expire))
+			break;
+	}
+}
+
+/*
+ * This routine is called by tty_hangup() when a hangup is signaled.
+ */
+static void mxser_hangup(struct tty_struct *tty)
+{
+	struct mxser_port *info = tty->driver_data;
+
+	mxser_flush_buffer(tty);
+	tty_port_hangup(&info->port);
+}
+
+/*
+ * mxser_rs_break() --- routine which turns the break handling on or off
+ */
+static int mxser_rs_break(struct tty_struct *tty, int break_state)
+{
+	struct mxser_port *info = tty->driver_data;
+	unsigned long flags;
+	u8 lcr;
+
+	spin_lock_irqsave(&info->slock, flags);
+	lcr = inb(info->ioaddr + UART_LCR);
+	if (break_state == -1)
+		lcr |= UART_LCR_SBC;
+	else
+		lcr &= ~UART_LCR_SBC;
+	outb(lcr, info->ioaddr + UART_LCR);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	return 0;
+}
+
+static bool mxser_receive_chars_new(struct mxser_port *port, u8 status)
+{
+	enum mxser_must_hwid hwid = port->board->must_hwid;
+	u8 gdl;
+
+	if (hwid == MOXA_OTHER_UART)
+		return false;
+	if (status & (UART_LSR_BRK_ERROR_BITS | MOXA_MUST_LSR_RERR))
+		return false;
+
+	gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
+	if (hwid == MOXA_MUST_MU150_HWID)
+		gdl &= MOXA_MUST_GDL_MASK;
+
+	while (gdl--) {
+		u8 ch = inb(port->ioaddr + UART_RX);
+		if (!tty_insert_flip_char(&port->port, ch, 0))
+			port->icount.buf_overrun++;
+	}
+
+	return true;
+}
+
+static u8 mxser_receive_chars_old(struct tty_struct *tty,
+		                struct mxser_port *port, u8 status)
+{
+	enum mxser_must_hwid hwid = port->board->must_hwid;
+	int ignored = 0;
+	int max = 256;
+	u8 ch;
+
+	do {
+		if (max-- < 0)
+			break;
+
+		ch = inb(port->ioaddr + UART_RX);
+		if (hwid && (status & UART_LSR_OE))
+			outb(port->FCR | UART_FCR_CLEAR_RCVR,
+					port->ioaddr + UART_FCR);
+		status &= port->read_status_mask;
+		if (status & port->ignore_status_mask) {
+			if (++ignored > 100)
+				break;
+		} else {
+			char flag = 0;
+			if (status & UART_LSR_BRK_ERROR_BITS) {
+				if (status & UART_LSR_BI) {
+					flag = TTY_BREAK;
+					port->icount.brk++;
+
+					if (port->port.flags & ASYNC_SAK)
+						do_SAK(tty);
+				} else if (status & UART_LSR_PE) {
+					flag = TTY_PARITY;
+					port->icount.parity++;
+				} else if (status & UART_LSR_FE) {
+					flag = TTY_FRAME;
+					port->icount.frame++;
+				} else if (status & UART_LSR_OE) {
+					flag = TTY_OVERRUN;
+					port->icount.overrun++;
+				}
+			}
+			if (!tty_insert_flip_char(&port->port, ch, flag)) {
+				port->icount.buf_overrun++;
+				break;
+			}
+		}
+
+		if (hwid)
+			break;
+
+		status = inb(port->ioaddr + UART_LSR);
+	} while (status & UART_LSR_DR);
+
+	return status;
+}
+
+static u8 mxser_receive_chars(struct tty_struct *tty,
+		struct mxser_port *port, u8 status)
+{
+	if (!mxser_receive_chars_new(port, status))
+		status = mxser_receive_chars_old(tty, port, status);
+
+	tty_flip_buffer_push(&port->port);
+
+	return status;
+}
+
+static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port)
+{
+	int count;
+
+	if (port->x_char) {
+		outb(port->x_char, port->ioaddr + UART_TX);
+		port->x_char = 0;
+		port->icount.tx++;
+		return;
+	}
+
+	if (kfifo_is_empty(&port->port.xmit_fifo) || tty->flow.stopped ||
+			(tty->hw_stopped && !mxser_16550A_or_MUST(port))) {
+		__mxser_stop_tx(port);
+		return;
+	}
+
+	count = port->xmit_fifo_size;
+	do {
+		unsigned char c;
+
+		if (!kfifo_get(&port->port.xmit_fifo, &c))
+			break;
+
+		outb(c, port->ioaddr + UART_TX);
+		port->icount.tx++;
+	} while (--count > 0);
+
+	if (kfifo_len(&port->port.xmit_fifo) < WAKEUP_CHARS)
+		tty_wakeup(tty);
+
+	if (kfifo_is_empty(&port->port.xmit_fifo))
+		__mxser_stop_tx(port);
+}
+
+static bool mxser_port_isr(struct mxser_port *port)
+{
+	struct tty_struct *tty;
+	u8 iir, status;
+	bool error = false;
+
+	iir = inb(port->ioaddr + UART_IIR);
+	if (iir & UART_IIR_NO_INT)
+		return true;
+
+	iir &= MOXA_MUST_IIR_MASK;
+	tty = tty_port_tty_get(&port->port);
+	if (!tty) {
+		status = inb(port->ioaddr + UART_LSR);
+		outb(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+				port->ioaddr + UART_FCR);
+		inb(port->ioaddr + UART_MSR);
+
+		error = true;
+		goto put_tty;
+	}
+
+	status = inb(port->ioaddr + UART_LSR);
+
+	if (port->board->must_hwid) {
+		if (iir == MOXA_MUST_IIR_GDA ||
+		    iir == MOXA_MUST_IIR_RDA ||
+		    iir == MOXA_MUST_IIR_RTO ||
+		    iir == MOXA_MUST_IIR_LSR)
+			status = mxser_receive_chars(tty, port, status);
+	} else {
+		status &= port->read_status_mask;
+		if (status & UART_LSR_DR)
+			status = mxser_receive_chars(tty, port, status);
+	}
+
+	mxser_check_modem_status(tty, port);
+
+	if (port->board->must_hwid) {
+		if (iir == 0x02 && (status & UART_LSR_THRE))
+			mxser_transmit_chars(tty, port);
+	} else {
+		if (status & UART_LSR_THRE)
+			mxser_transmit_chars(tty, port);
+	}
+
+put_tty:
+	tty_kref_put(tty);
+
+	return error;
+}
+
+/*
+ * This is the serial driver's generic interrupt routine
+ */
+static irqreturn_t mxser_interrupt(int irq, void *dev_id)
+{
+	struct mxser_board *brd = dev_id;
+	struct mxser_port *port;
+	unsigned int int_cnt, pass_counter = 0;
+	unsigned int i, max = brd->nports;
+	int handled = IRQ_NONE;
+	u8 irqbits, bits, mask = BIT(max) - 1;
+
+	while (pass_counter++ < MXSER_ISR_PASS_LIMIT) {
+		irqbits = inb(brd->vector) & mask;
+		if (irqbits == mask)
+			break;
+
+		handled = IRQ_HANDLED;
+		for (i = 0, bits = 1; i < max; i++, irqbits |= bits, bits <<= 1) {
+			if (irqbits == mask)
+				break;
+			if (bits & irqbits)
+				continue;
+			port = &brd->ports[i];
+
+			int_cnt = 0;
+			spin_lock(&port->slock);
+			do {
+				if (mxser_port_isr(port))
+					break;
+			} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
+			spin_unlock(&port->slock);
+		}
+	}
+
+	return handled;
+}
+
+static const struct tty_operations mxser_ops = {
+	.open = mxser_open,
+	.close = mxser_close,
+	.write = mxser_write,
+	.put_char = mxser_put_char,
+	.flush_chars = mxser_flush_chars,
+	.write_room = mxser_write_room,
+	.chars_in_buffer = mxser_chars_in_buffer,
+	.flush_buffer = mxser_flush_buffer,
+	.ioctl = mxser_ioctl,
+	.throttle = mxser_throttle,
+	.unthrottle = mxser_unthrottle,
+	.set_termios = mxser_set_termios,
+	.stop = mxser_stop,
+	.start = mxser_start,
+	.hangup = mxser_hangup,
+	.break_ctl = mxser_rs_break,
+	.wait_until_sent = mxser_wait_until_sent,
+	.tiocmget = mxser_tiocmget,
+	.tiocmset = mxser_tiocmset,
+	.set_serial = mxser_set_serial_info,
+	.get_serial = mxser_get_serial_info,
+	.get_icount = mxser_get_icount,
+};
+
+static const struct tty_port_operations mxser_port_ops = {
+	.carrier_raised = mxser_carrier_raised,
+	.dtr_rts = mxser_dtr_rts,
+	.activate = mxser_activate,
+	.shutdown = mxser_shutdown_port,
+};
+
+/*
+ * The MOXA Smartio/Industio serial driver boot-time initialization code!
+ */
+
+static void mxser_initbrd(struct mxser_board *brd, bool high_baud)
+{
+	struct mxser_port *info;
+	unsigned int i;
+	bool is_mu860;
+
+	brd->must_hwid = mxser_must_get_hwid(brd->ports[0].ioaddr);
+	is_mu860 = brd->must_hwid == MOXA_MUST_MU860_HWID;
+
+	for (i = 0; i < UART_INFO_NUM; i++) {
+		if (Gpci_uart_info[i].type == brd->must_hwid) {
+			brd->max_baud = Gpci_uart_info[i].max_baud;
+
+			/* exception....CP-102 */
+			if (high_baud)
+				brd->max_baud = 921600;
+			break;
+		}
+	}
+
+	if (is_mu860) {
+		/* set to RS232 mode by default */
+		outb(0, brd->vector + 4);
+		outb(0, brd->vector + 0x0c);
+	}
+
+	for (i = 0; i < brd->nports; i++) {
+		info = &brd->ports[i];
+		if (is_mu860) {
+			if (i < 4)
+				info->opmode_ioaddr = brd->vector + 4;
+			else
+				info->opmode_ioaddr = brd->vector + 0x0c;
+		}
+		tty_port_init(&info->port);
+		info->port.ops = &mxser_port_ops;
+		info->board = brd;
+
+		/* Enhance mode enabled here */
+		if (brd->must_hwid != MOXA_OTHER_UART)
+			mxser_must_set_enhance_mode(info->ioaddr, true);
+
+		info->type = PORT_16550A;
+
+		mxser_process_txrx_fifo(info);
+
+		info->port.close_delay = 5 * HZ / 10;
+		info->port.closing_wait = 30 * HZ;
+		spin_lock_init(&info->slock);
+
+		/* before set INT ISR, disable all int */
+		outb(inb(info->ioaddr + UART_IER) & 0xf0,
+			info->ioaddr + UART_IER);
+	}
+}
+
+static int mxser_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	struct mxser_board *brd;
+	unsigned int i, base;
+	unsigned long ioaddress;
+	unsigned short nports = MXSER_NPORTS(ent->driver_data);
+	struct device *tty_dev;
+	int retval = -EINVAL;
+
+	i = find_first_zero_bit(mxser_boards, MXSER_BOARDS);
+	if (i >= MXSER_BOARDS) {
+		dev_err(&pdev->dev, "too many boards found (maximum %d), board "
+				"not configured\n", MXSER_BOARDS);
+		goto err;
+	}
+
+	brd = devm_kzalloc(&pdev->dev, struct_size(brd, ports, nports),
+			GFP_KERNEL);
+	if (!brd)
+		goto err;
+
+	brd->idx = i;
+	__set_bit(brd->idx, mxser_boards);
+	base = i * MXSER_PORTS_PER_BOARD;
+
+	retval = pcim_enable_device(pdev);
+	if (retval) {
+		dev_err(&pdev->dev, "PCI enable failed\n");
+		goto err_zero;
+	}
+
+	/* io address */
+	ioaddress = pci_resource_start(pdev, 2);
+	retval = pci_request_region(pdev, 2, "mxser(IO)");
+	if (retval)
+		goto err_zero;
+
+	brd->nports = nports;
+	for (i = 0; i < nports; i++)
+		brd->ports[i].ioaddr = ioaddress + 8 * i;
+
+	/* vector */
+	ioaddress = pci_resource_start(pdev, 3);
+	retval = pci_request_region(pdev, 3, "mxser(vector)");
+	if (retval)
+		goto err_zero;
+	brd->vector = ioaddress;
+
+	/* irq */
+	brd->irq = pdev->irq;
+
+	mxser_initbrd(brd, ent->driver_data & MXSER_HIGHBAUD);
+
+	retval = devm_request_irq(&pdev->dev, brd->irq, mxser_interrupt,
+			IRQF_SHARED, "mxser", brd);
+	if (retval) {
+		dev_err(&pdev->dev, "request irq failed");
+		goto err_relbrd;
+	}
+
+	for (i = 0; i < nports; i++) {
+		tty_dev = tty_port_register_device(&brd->ports[i].port,
+				mxvar_sdriver, base + i, &pdev->dev);
+		if (IS_ERR(tty_dev)) {
+			retval = PTR_ERR(tty_dev);
+			for (; i > 0; i--)
+				tty_unregister_device(mxvar_sdriver,
+					base + i - 1);
+			goto err_relbrd;
+		}
+	}
+
+	pci_set_drvdata(pdev, brd);
+
+	return 0;
+err_relbrd:
+	for (i = 0; i < nports; i++)
+		tty_port_destroy(&brd->ports[i].port);
+err_zero:
+	__clear_bit(brd->idx, mxser_boards);
+err:
+	return retval;
+}
+
+static void mxser_remove(struct pci_dev *pdev)
+{
+	struct mxser_board *brd = pci_get_drvdata(pdev);
+	unsigned int i, base = brd->idx * MXSER_PORTS_PER_BOARD;
+
+	for (i = 0; i < brd->nports; i++) {
+		tty_unregister_device(mxvar_sdriver, base + i);
+		tty_port_destroy(&brd->ports[i].port);
+	}
+
+	__clear_bit(brd->idx, mxser_boards);
+}
+
+static struct pci_driver mxser_driver = {
+	.name = "mxser",
+	.id_table = mxser_pcibrds,
+	.probe = mxser_probe,
+	.remove = mxser_remove
+};
+
+static int __init mxser_module_init(void)
+{
+	int retval;
+
+	mxvar_sdriver = tty_alloc_driver(MXSER_PORTS, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(mxvar_sdriver))
+		return PTR_ERR(mxvar_sdriver);
+
+	/* Initialize the tty_driver structure */
+	mxvar_sdriver->name = "ttyMI";
+	mxvar_sdriver->major = ttymajor;
+	mxvar_sdriver->minor_start = 0;
+	mxvar_sdriver->type = TTY_DRIVER_TYPE_SERIAL;
+	mxvar_sdriver->subtype = SERIAL_TYPE_NORMAL;
+	mxvar_sdriver->init_termios = tty_std_termios;
+	mxvar_sdriver->init_termios.c_cflag = B9600|CS8|CREAD|HUPCL|CLOCAL;
+	tty_set_operations(mxvar_sdriver, &mxser_ops);
+
+	retval = tty_register_driver(mxvar_sdriver);
+	if (retval) {
+		printk(KERN_ERR "Couldn't install MOXA Smartio/Industio family "
+				"tty driver !\n");
+		goto err_put;
+	}
+
+	retval = pci_register_driver(&mxser_driver);
+	if (retval) {
+		printk(KERN_ERR "mxser: can't register pci driver\n");
+		goto err_unr;
+	}
+
+	return 0;
+err_unr:
+	tty_unregister_driver(mxvar_sdriver);
+err_put:
+	tty_driver_kref_put(mxvar_sdriver);
+	return retval;
+}
+
+static void __exit mxser_module_exit(void)
+{
+	pci_unregister_driver(&mxser_driver);
+	tty_unregister_driver(mxvar_sdriver);
+	tty_driver_kref_put(mxvar_sdriver);
+}
+
+module_init(mxser_module_init);
+module_exit(mxser_module_exit);
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
new file mode 100644
index 000000000..0ee7531c9
--- /dev/null
+++ b/drivers/tty/n_gsm.c
@@ -0,0 +1,4584 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * n_gsm.c GSM 0710 tty multiplexor
+ * Copyright (c) 2009/10 Intel Corporation
+ *
+ *	* THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE *
+ *
+ * Outgoing path:
+ * tty -> DLCI fifo -> scheduler -> GSM MUX data queue    ---o-> ldisc
+ * control message               -> GSM MUX control queue --´
+ *
+ * Incoming path:
+ * ldisc -> gsm_queue() -o--> tty
+ *                        `-> gsm_control_response()
+ *
+ * TO DO:
+ *	Mostly done:	ioctls for setting modes/timing
+ *	Partly done:	hooks so you can pull off frames to non tty devs
+ *	Restart DLCI 0 when it closes ?
+ *	Improve the tx engine
+ *	Resolve tx side locking by adding a queue_head and routing
+ *		all control traffic via it
+ *	General tidy/document
+ *	Review the locking/move to refcounts more (mux now moved to an
+ *		alloc/free model ready)
+ *	Use newest tty open/close port helpers and install hooks
+ *	What to do about power functions ?
+ *	Termios setting and negotiation
+ *	Do we need a 'which mux are you' ioctl to correlate mux and tty sets
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched/signal.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/bitfield.h>
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/math.h>
+#include <linux/nospec.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/bitops.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/tty_flip.h>
+#include <linux/tty_driver.h>
+#include <linux/serial.h>
+#include <linux/kfifo.h>
+#include <linux/skbuff.h>
+#include <net/arp.h>
+#include <linux/ip.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/gsmmux.h>
+#include "tty.h"
+
+static int debug;
+module_param(debug, int, 0600);
+
+/* Module debug bits */
+#define DBG_DUMP	BIT(0) /* Data transmission dump. */
+#define DBG_CD_ON	BIT(1) /* Always assume CD line on. */
+#define DBG_DATA	BIT(2) /* Data transmission details. */
+#define DBG_ERRORS	BIT(3) /* Details for fail conditions. */
+#define DBG_TTY		BIT(4) /* Transmission statistics for DLCI TTYs. */
+#define DBG_PAYLOAD	BIT(5) /* Limits DBG_DUMP to payload frames. */
+
+/* Defaults: these are from the specification */
+
+#define T1	10		/* 100mS */
+#define T2	34		/* 333mS */
+#define T3	10		/* 10s */
+#define N2	3		/* Retry 3 times */
+#define K	2		/* outstanding I frames */
+
+#define MAX_T3 255		/* In seconds. */
+#define MAX_WINDOW_SIZE 7	/* Limit of K in error recovery mode. */
+
+/* Use long timers for testing at low speed with debug on */
+#ifdef DEBUG_TIMING
+#define T1	100
+#define T2	200
+#endif
+
+/*
+ * Semi-arbitrary buffer size limits. 0710 is normally run with 32-64 byte
+ * limits so this is plenty
+ */
+#define MAX_MRU 1500
+#define MAX_MTU 1500
+#define MIN_MTU (PROT_OVERHEAD + 1)
+/* SOF, ADDR, CTRL, LEN1, LEN2, ..., FCS, EOF */
+#define PROT_OVERHEAD 7
+#define	GSM_NET_TX_TIMEOUT (HZ*10)
+
+/*
+ *	struct gsm_mux_net	-	network interface
+ *
+ *	Created when net interface is initialized.
+ */
+struct gsm_mux_net {
+	struct kref ref;
+	struct gsm_dlci *dlci;
+};
+
+/*
+ *	Each block of data we have queued to go out is in the form of
+ *	a gsm_msg which holds everything we need in a link layer independent
+ *	format
+ */
+
+struct gsm_msg {
+	struct list_head list;
+	u8 addr;		/* DLCI address + flags */
+	u8 ctrl;		/* Control byte + flags */
+	unsigned int len;	/* Length of data block (can be zero) */
+	unsigned char *data;	/* Points into buffer but not at the start */
+	unsigned char buffer[];
+};
+
+enum gsm_dlci_state {
+	DLCI_CLOSED,
+	DLCI_WAITING_CONFIG,	/* Waiting for DLCI configuration from user */
+	DLCI_CONFIGURE,		/* Sending PN (for adaption > 1) */
+	DLCI_OPENING,		/* Sending SABM not seen UA */
+	DLCI_OPEN,		/* SABM/UA complete */
+	DLCI_CLOSING,		/* Sending DISC not seen UA/DM */
+};
+
+enum gsm_dlci_mode {
+	DLCI_MODE_ABM,		/* Normal Asynchronous Balanced Mode */
+	DLCI_MODE_ADM,		/* Asynchronous Disconnected Mode */
+};
+
+/*
+ *	Each active data link has a gsm_dlci structure associated which ties
+ *	the link layer to an optional tty (if the tty side is open). To avoid
+ *	complexity right now these are only ever freed up when the mux is
+ *	shut down.
+ *
+ *	At the moment we don't free DLCI objects until the mux is torn down
+ *	this avoid object life time issues but might be worth review later.
+ */
+
+struct gsm_dlci {
+	struct gsm_mux *gsm;
+	int addr;
+	enum gsm_dlci_state state;
+	struct mutex mutex;
+
+	/* Link layer */
+	enum gsm_dlci_mode mode;
+	spinlock_t lock;	/* Protects the internal state */
+	struct timer_list t1;	/* Retransmit timer for SABM and UA */
+	int retries;
+	/* Uplink tty if active */
+	struct tty_port port;	/* The tty bound to this DLCI if there is one */
+#define TX_SIZE		4096    /* Must be power of 2. */
+	struct kfifo fifo;	/* Queue fifo for the DLCI */
+	int adaption;		/* Adaption layer in use */
+	int prev_adaption;
+	u32 modem_rx;		/* Our incoming virtual modem lines */
+	u32 modem_tx;		/* Our outgoing modem lines */
+	unsigned int mtu;
+	bool dead;		/* Refuse re-open */
+	/* Configuration */
+	u8 prio;		/* Priority */
+	u8 ftype;		/* Frame type */
+	u8 k;			/* Window size */
+	/* Flow control */
+	bool throttled;		/* Private copy of throttle state */
+	bool constipated;	/* Throttle status for outgoing */
+	/* Packetised I/O */
+	struct sk_buff *skb;	/* Frame being sent */
+	struct sk_buff_head skb_list;	/* Queued frames */
+	/* Data handling callback */
+	void (*data)(struct gsm_dlci *dlci, const u8 *data, int len);
+	void (*prev_data)(struct gsm_dlci *dlci, const u8 *data, int len);
+	struct net_device *net; /* network interface, if created */
+};
+
+/*
+ * Parameter bits used for parameter negotiation according to 3GPP 27.010
+ * chapter 5.4.6.3.1.
+ */
+
+struct gsm_dlci_param_bits {
+	u8 d_bits;
+	u8 i_cl_bits;
+	u8 p_bits;
+	u8 t_bits;
+	__le16 n_bits;
+	u8 na_bits;
+	u8 k_bits;
+};
+
+static_assert(sizeof(struct gsm_dlci_param_bits) == 8);
+
+#define PN_D_FIELD_DLCI		GENMASK(5, 0)
+#define PN_I_CL_FIELD_FTYPE	GENMASK(3, 0)
+#define PN_I_CL_FIELD_ADAPTION	GENMASK(7, 4)
+#define PN_P_FIELD_PRIO		GENMASK(5, 0)
+#define PN_T_FIELD_T1		GENMASK(7, 0)
+#define PN_N_FIELD_N1		GENMASK(15, 0)
+#define PN_NA_FIELD_N2		GENMASK(7, 0)
+#define PN_K_FIELD_K		GENMASK(2, 0)
+
+/* Total number of supported devices */
+#define GSM_TTY_MINORS		256
+
+/* DLCI 0, 62/63 are special or reserved see gsmtty_open */
+
+#define NUM_DLCI		64
+
+/*
+ *	DLCI 0 is used to pass control blocks out of band of the data
+ *	flow (and with a higher link priority). One command can be outstanding
+ *	at a time and we use this structure to manage them. They are created
+ *	and destroyed by the user context, and updated by the receive paths
+ *	and timers
+ */
+
+struct gsm_control {
+	u8 cmd;		/* Command we are issuing */
+	u8 *data;	/* Data for the command in case we retransmit */
+	int len;	/* Length of block for retransmission */
+	int done;	/* Done flag */
+	int error;	/* Error if any */
+};
+
+enum gsm_encoding {
+	GSM_BASIC_OPT,
+	GSM_ADV_OPT,
+};
+
+enum gsm_mux_state {
+	GSM_SEARCH,
+	GSM_START,
+	GSM_ADDRESS,
+	GSM_CONTROL,
+	GSM_LEN,
+	GSM_DATA,
+	GSM_FCS,
+	GSM_OVERRUN,
+	GSM_LEN0,
+	GSM_LEN1,
+	GSM_SSOF,
+};
+
+/*
+ *	Each GSM mux we have is represented by this structure. If we are
+ *	operating as an ldisc then we use this structure as our ldisc
+ *	state. We need to sort out lifetimes and locking with respect
+ *	to the gsm mux array. For now we don't free DLCI objects that
+ *	have been instantiated until the mux itself is terminated.
+ *
+ *	To consider further: tty open versus mux shutdown.
+ */
+
+struct gsm_mux {
+	struct tty_struct *tty;		/* The tty our ldisc is bound to */
+	spinlock_t lock;
+	struct mutex mutex;
+	unsigned int num;
+	struct kref ref;
+
+	/* Events on the GSM channel */
+	wait_queue_head_t event;
+
+	/* ldisc send work */
+	struct work_struct tx_work;
+
+	/* Bits for GSM mode decoding */
+
+	/* Framing Layer */
+	unsigned char *buf;
+	enum gsm_mux_state state;
+	unsigned int len;
+	unsigned int address;
+	unsigned int count;
+	bool escape;
+	enum gsm_encoding encoding;
+	u8 control;
+	u8 fcs;
+	u8 *txframe;			/* TX framing buffer */
+
+	/* Method for the receiver side */
+	void (*receive)(struct gsm_mux *gsm, u8 ch);
+
+	/* Link Layer */
+	unsigned int mru;
+	unsigned int mtu;
+	int initiator;			/* Did we initiate connection */
+	bool dead;			/* Has the mux been shut down */
+	struct gsm_dlci *dlci[NUM_DLCI];
+	int old_c_iflag;		/* termios c_iflag value before attach */
+	bool constipated;		/* Asked by remote to shut up */
+	bool has_devices;		/* Devices were registered */
+
+	spinlock_t tx_lock;
+	unsigned int tx_bytes;		/* TX data outstanding */
+#define TX_THRESH_HI		8192
+#define TX_THRESH_LO		2048
+	struct list_head tx_ctrl_list;	/* Pending control packets */
+	struct list_head tx_data_list;	/* Pending data packets */
+
+	/* Control messages */
+	struct timer_list kick_timer;	/* Kick TX queuing on timeout */
+	struct timer_list t2_timer;	/* Retransmit timer for commands */
+	int cretries;			/* Command retry counter */
+	struct gsm_control *pending_cmd;/* Our current pending command */
+	spinlock_t control_lock;	/* Protects the pending command */
+
+	/* Keep-alive */
+	struct timer_list ka_timer;	/* Keep-alive response timer */
+	u8 ka_num;			/* Keep-alive match pattern */
+	signed int ka_retries;		/* Keep-alive retry counter, -1 if not yet initialized */
+
+	/* Configuration */
+	int adaption;		/* 1 or 2 supported */
+	u8 ftype;		/* UI or UIH */
+	int t1, t2;		/* Timers in 1/100th of a sec */
+	unsigned int t3;	/* Power wake-up timer in seconds. */
+	int n2;			/* Retry count */
+	u8 k;			/* Window size */
+	bool wait_config;	/* Wait for configuration by ioctl before DLCI open */
+	u32 keep_alive;		/* Control channel keep-alive in 10ms */
+
+	/* Statistics (not currently exposed) */
+	unsigned long bad_fcs;
+	unsigned long malformed;
+	unsigned long io_error;
+	unsigned long open_error;
+	unsigned long bad_size;
+	unsigned long unsupported;
+};
+
+
+/*
+ *	Mux objects - needed so that we can translate a tty index into the
+ *	relevant mux and DLCI.
+ */
+
+#define MAX_MUX		4			/* 256 minors */
+static struct gsm_mux *gsm_mux[MAX_MUX];	/* GSM muxes */
+static DEFINE_SPINLOCK(gsm_mux_lock);
+
+static struct tty_driver *gsm_tty_driver;
+
+/*
+ *	This section of the driver logic implements the GSM encodings
+ *	both the basic and the 'advanced'. Reliable transport is not
+ *	supported.
+ */
+
+#define CR			0x02
+#define EA			0x01
+#define	PF			0x10
+
+/* I is special: the rest are ..*/
+#define RR			0x01
+#define UI			0x03
+#define RNR			0x05
+#define REJ			0x09
+#define DM			0x0F
+#define SABM			0x2F
+#define DISC			0x43
+#define UA			0x63
+#define	UIH			0xEF
+
+/* Channel commands */
+#define CMD_NSC			0x09
+#define CMD_TEST		0x11
+#define CMD_PSC			0x21
+#define CMD_RLS			0x29
+#define CMD_FCOFF		0x31
+#define CMD_PN			0x41
+#define CMD_RPN			0x49
+#define CMD_FCON		0x51
+#define CMD_CLD			0x61
+#define CMD_SNC			0x69
+#define CMD_MSC			0x71
+
+/* Virtual modem bits */
+#define MDM_FC			0x01
+#define MDM_RTC			0x02
+#define MDM_RTR			0x04
+#define MDM_IC			0x20
+#define MDM_DV			0x40
+
+#define GSM0_SOF		0xF9
+#define GSM1_SOF		0x7E
+#define GSM1_ESCAPE		0x7D
+#define GSM1_ESCAPE_BITS	0x20
+#define XON			0x11
+#define XOFF			0x13
+#define ISO_IEC_646_MASK	0x7F
+
+static const struct tty_port_operations gsm_port_ops;
+
+/*
+ *	CRC table for GSM 0710
+ */
+
+static const u8 gsm_fcs8[256] = {
+	0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
+	0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
+	0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
+	0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
+	0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
+	0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
+	0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
+	0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
+	0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
+	0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
+	0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
+	0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
+	0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
+	0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
+	0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
+	0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
+	0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
+	0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
+	0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
+	0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
+	0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
+	0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
+	0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
+	0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
+	0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
+	0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
+	0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
+	0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
+	0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
+	0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
+	0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
+	0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
+};
+
+#define INIT_FCS	0xFF
+#define GOOD_FCS	0xCF
+
+static void gsm_dlci_close(struct gsm_dlci *dlci);
+static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len);
+static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk);
+static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
+								u8 ctrl);
+static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg);
+static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr);
+static void gsmld_write_trigger(struct gsm_mux *gsm);
+static void gsmld_write_task(struct work_struct *work);
+
+/**
+ *	gsm_fcs_add	-	update FCS
+ *	@fcs: Current FCS
+ *	@c: Next data
+ *
+ *	Update the FCS to include c. Uses the algorithm in the specification
+ *	notes.
+ */
+
+static inline u8 gsm_fcs_add(u8 fcs, u8 c)
+{
+	return gsm_fcs8[fcs ^ c];
+}
+
+/**
+ *	gsm_fcs_add_block	-	update FCS for a block
+ *	@fcs: Current FCS
+ *	@c: buffer of data
+ *	@len: length of buffer
+ *
+ *	Update the FCS to include c. Uses the algorithm in the specification
+ *	notes.
+ */
+
+static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len)
+{
+	while (len--)
+		fcs = gsm_fcs8[fcs ^ *c++];
+	return fcs;
+}
+
+/**
+ *	gsm_read_ea		-	read a byte into an EA
+ *	@val: variable holding value
+ *	@c: byte going into the EA
+ *
+ *	Processes one byte of an EA. Updates the passed variable
+ *	and returns 1 if the EA is now completely read
+ */
+
+static int gsm_read_ea(unsigned int *val, u8 c)
+{
+	/* Add the next 7 bits into the value */
+	*val <<= 7;
+	*val |= c >> 1;
+	/* Was this the last byte of the EA 1 = yes*/
+	return c & EA;
+}
+
+/**
+ *	gsm_read_ea_val	-	read a value until EA
+ *	@val: variable holding value
+ *	@data: buffer of data
+ *	@dlen: length of data
+ *
+ *	Processes an EA value. Updates the passed variable and
+ *	returns the processed data length.
+ */
+static unsigned int gsm_read_ea_val(unsigned int *val, const u8 *data, int dlen)
+{
+	unsigned int len = 0;
+
+	for (; dlen > 0; dlen--) {
+		len++;
+		if (gsm_read_ea(val, *data++))
+			break;
+	}
+	return len;
+}
+
+/**
+ *	gsm_encode_modem	-	encode modem data bits
+ *	@dlci: DLCI to encode from
+ *
+ *	Returns the correct GSM encoded modem status bits (6 bit field) for
+ *	the current status of the DLCI and attached tty object
+ */
+
+static u8 gsm_encode_modem(const struct gsm_dlci *dlci)
+{
+	u8 modembits = 0;
+	/* FC is true flow control not modem bits */
+	if (dlci->throttled)
+		modembits |= MDM_FC;
+	if (dlci->modem_tx & TIOCM_DTR)
+		modembits |= MDM_RTC;
+	if (dlci->modem_tx & TIOCM_RTS)
+		modembits |= MDM_RTR;
+	if (dlci->modem_tx & TIOCM_RI)
+		modembits |= MDM_IC;
+	if (dlci->modem_tx & TIOCM_CD || dlci->gsm->initiator)
+		modembits |= MDM_DV;
+	/* special mappings for passive side to operate as UE */
+	if (dlci->modem_tx & TIOCM_OUT1)
+		modembits |= MDM_IC;
+	if (dlci->modem_tx & TIOCM_OUT2)
+		modembits |= MDM_DV;
+	return modembits;
+}
+
+static void gsm_hex_dump_bytes(const char *fname, const u8 *data,
+			       unsigned long len)
+{
+	char *prefix;
+
+	if (!fname) {
+		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, data, len,
+			       true);
+		return;
+	}
+
+	prefix = kasprintf(GFP_ATOMIC, "%s: ", fname);
+	if (!prefix)
+		return;
+	print_hex_dump(KERN_INFO, prefix, DUMP_PREFIX_OFFSET, 16, 1, data, len,
+		       true);
+	kfree(prefix);
+}
+
+/**
+ * gsm_encode_params	-	encode DLCI parameters
+ * @dlci: DLCI to encode from
+ * @params: buffer to fill with the encoded parameters
+ *
+ * Encodes the parameters according to GSM 07.10 section 5.4.6.3.1
+ * table 3.
+ */
+static int gsm_encode_params(const struct gsm_dlci *dlci,
+			     struct gsm_dlci_param_bits *params)
+{
+	const struct gsm_mux *gsm = dlci->gsm;
+	unsigned int i, cl;
+
+	switch (dlci->ftype) {
+	case UIH:
+		i = 0; /* UIH */
+		break;
+	case UI:
+		i = 1; /* UI */
+		break;
+	default:
+		pr_debug("unsupported frame type %d\n", dlci->ftype);
+		return -EINVAL;
+	}
+
+	switch (dlci->adaption) {
+	case 1: /* Unstructured */
+		cl = 0; /* convergence layer type 1 */
+		break;
+	case 2: /* Unstructured with modem bits. */
+		cl = 1; /* convergence layer type 2 */
+		break;
+	default:
+		pr_debug("unsupported adaption %d\n", dlci->adaption);
+		return -EINVAL;
+	}
+
+	params->d_bits = FIELD_PREP(PN_D_FIELD_DLCI, dlci->addr);
+	/* UIH, convergence layer type 1 */
+	params->i_cl_bits = FIELD_PREP(PN_I_CL_FIELD_FTYPE, i) |
+			    FIELD_PREP(PN_I_CL_FIELD_ADAPTION, cl);
+	params->p_bits = FIELD_PREP(PN_P_FIELD_PRIO, dlci->prio);
+	params->t_bits = FIELD_PREP(PN_T_FIELD_T1, gsm->t1);
+	params->n_bits = cpu_to_le16(FIELD_PREP(PN_N_FIELD_N1, dlci->mtu));
+	params->na_bits = FIELD_PREP(PN_NA_FIELD_N2, gsm->n2);
+	params->k_bits = FIELD_PREP(PN_K_FIELD_K, dlci->k);
+
+	return 0;
+}
+
+/**
+ *	gsm_register_devices	-	register all tty devices for a given mux index
+ *
+ *	@driver: the tty driver that describes the tty devices
+ *	@index:  the mux number is used to calculate the minor numbers of the
+ *	         ttys for this mux and may differ from the position in the
+ *	         mux array.
+ */
+static int gsm_register_devices(struct tty_driver *driver, unsigned int index)
+{
+	struct device *dev;
+	int i;
+	unsigned int base;
+
+	if (!driver || index >= MAX_MUX)
+		return -EINVAL;
+
+	base = index * NUM_DLCI; /* first minor for this index */
+	for (i = 1; i < NUM_DLCI; i++) {
+		/* Don't register device 0 - this is the control channel
+		 * and not a usable tty interface
+		 */
+		dev = tty_register_device(gsm_tty_driver, base + i, NULL);
+		if (IS_ERR(dev)) {
+			if (debug & DBG_ERRORS)
+				pr_info("%s failed to register device minor %u",
+					__func__, base + i);
+			for (i--; i >= 1; i--)
+				tty_unregister_device(gsm_tty_driver, base + i);
+			return PTR_ERR(dev);
+		}
+	}
+
+	return 0;
+}
+
+/**
+ *	gsm_unregister_devices	-	unregister all tty devices for a given mux index
+ *
+ *	@driver: the tty driver that describes the tty devices
+ *	@index:  the mux number is used to calculate the minor numbers of the
+ *	         ttys for this mux and may differ from the position in the
+ *	         mux array.
+ */
+static void gsm_unregister_devices(struct tty_driver *driver,
+				   unsigned int index)
+{
+	int i;
+	unsigned int base;
+
+	if (!driver || index >= MAX_MUX)
+		return;
+
+	base = index * NUM_DLCI; /* first minor for this index */
+	for (i = 1; i < NUM_DLCI; i++) {
+		/* Don't unregister device 0 - this is the control
+		 * channel and not a usable tty interface
+		 */
+		tty_unregister_device(gsm_tty_driver, base + i);
+	}
+}
+
+/**
+ *	gsm_print_packet	-	display a frame for debug
+ *	@hdr: header to print before decode
+ *	@addr: address EA from the frame
+ *	@cr: C/R bit seen as initiator
+ *	@control: control including PF bit
+ *	@data: following data bytes
+ *	@dlen: length of data
+ *
+ *	Displays a packet in human readable format for debugging purposes. The
+ *	style is based on amateur radio LAP-B dump display.
+ */
+
+static void gsm_print_packet(const char *hdr, int addr, int cr,
+					u8 control, const u8 *data, int dlen)
+{
+	if (!(debug & DBG_DUMP))
+		return;
+	/* Only show user payload frames if debug & DBG_PAYLOAD */
+	if (!(debug & DBG_PAYLOAD) && addr != 0)
+		if ((control & ~PF) == UI || (control & ~PF) == UIH)
+			return;
+
+	pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]);
+
+	switch (control & ~PF) {
+	case SABM:
+		pr_cont("SABM");
+		break;
+	case UA:
+		pr_cont("UA");
+		break;
+	case DISC:
+		pr_cont("DISC");
+		break;
+	case DM:
+		pr_cont("DM");
+		break;
+	case UI:
+		pr_cont("UI");
+		break;
+	case UIH:
+		pr_cont("UIH");
+		break;
+	default:
+		if (!(control & 0x01)) {
+			pr_cont("I N(S)%d N(R)%d",
+				(control & 0x0E) >> 1, (control & 0xE0) >> 5);
+		} else switch (control & 0x0F) {
+			case RR:
+				pr_cont("RR(%d)", (control & 0xE0) >> 5);
+				break;
+			case RNR:
+				pr_cont("RNR(%d)", (control & 0xE0) >> 5);
+				break;
+			case REJ:
+				pr_cont("REJ(%d)", (control & 0xE0) >> 5);
+				break;
+			default:
+				pr_cont("[%02X]", control);
+		}
+	}
+
+	if (control & PF)
+		pr_cont("(P)");
+	else
+		pr_cont("(F)");
+
+	gsm_hex_dump_bytes(NULL, data, dlen);
+}
+
+
+/*
+ *	Link level transmission side
+ */
+
+/**
+ *	gsm_stuff_frame	-	bytestuff a packet
+ *	@input: input buffer
+ *	@output: output buffer
+ *	@len: length of input
+ *
+ *	Expand a buffer by bytestuffing it. The worst case size change
+ *	is doubling and the caller is responsible for handing out
+ *	suitable sized buffers.
+ */
+
+static int gsm_stuff_frame(const u8 *input, u8 *output, int len)
+{
+	int olen = 0;
+	while (len--) {
+		if (*input == GSM1_SOF || *input == GSM1_ESCAPE
+		    || (*input & ISO_IEC_646_MASK) == XON
+		    || (*input & ISO_IEC_646_MASK) == XOFF) {
+			*output++ = GSM1_ESCAPE;
+			*output++ = *input++ ^ GSM1_ESCAPE_BITS;
+			olen++;
+		} else
+			*output++ = *input++;
+		olen++;
+	}
+	return olen;
+}
+
+/**
+ *	gsm_send	-	send a control frame
+ *	@gsm: our GSM mux
+ *	@addr: address for control frame
+ *	@cr: command/response bit seen as initiator
+ *	@control:  control byte including PF bit
+ *
+ *	Format up and transmit a control frame. These should be transmitted
+ *	ahead of data when they are needed.
+ */
+static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
+{
+	struct gsm_msg *msg;
+	u8 *dp;
+	int ocr;
+	unsigned long flags;
+
+	msg = gsm_data_alloc(gsm, addr, 0, control);
+	if (!msg)
+		return -ENOMEM;
+
+	/* toggle C/R coding if not initiator */
+	ocr = cr ^ (gsm->initiator ? 0 : 1);
+
+	msg->data -= 3;
+	dp = msg->data;
+	*dp++ = (addr << 2) | (ocr << 1) | EA;
+	*dp++ = control;
+
+	if (gsm->encoding == GSM_BASIC_OPT)
+		*dp++ = EA; /* Length of data = 0 */
+
+	*dp = 0xFF - gsm_fcs_add_block(INIT_FCS, msg->data, dp - msg->data);
+	msg->len = (dp - msg->data) + 1;
+
+	gsm_print_packet("Q->", addr, cr, control, NULL, 0);
+
+	spin_lock_irqsave(&gsm->tx_lock, flags);
+	list_add_tail(&msg->list, &gsm->tx_ctrl_list);
+	gsm->tx_bytes += msg->len;
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
+	gsmld_write_trigger(gsm);
+
+	return 0;
+}
+
+/**
+ *	gsm_dlci_clear_queues	-	remove outstanding data for a DLCI
+ *	@gsm: mux
+ *	@dlci: clear for this DLCI
+ *
+ *	Clears the data queues for a given DLCI.
+ */
+static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci)
+{
+	struct gsm_msg *msg, *nmsg;
+	int addr = dlci->addr;
+	unsigned long flags;
+
+	/* Clear DLCI write fifo first */
+	spin_lock_irqsave(&dlci->lock, flags);
+	kfifo_reset(&dlci->fifo);
+	spin_unlock_irqrestore(&dlci->lock, flags);
+
+	/* Clear data packets in MUX write queue */
+	spin_lock_irqsave(&gsm->tx_lock, flags);
+	list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) {
+		if (msg->addr != addr)
+			continue;
+		gsm->tx_bytes -= msg->len;
+		list_del(&msg->list);
+		kfree(msg);
+	}
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
+}
+
+/**
+ *	gsm_response	-	send a control response
+ *	@gsm: our GSM mux
+ *	@addr: address for control frame
+ *	@control:  control byte including PF bit
+ *
+ *	Format up and transmit a link level response frame.
+ */
+
+static inline void gsm_response(struct gsm_mux *gsm, int addr, int control)
+{
+	gsm_send(gsm, addr, 0, control);
+}
+
+/**
+ *	gsm_command	-	send a control command
+ *	@gsm: our GSM mux
+ *	@addr: address for control frame
+ *	@control:  control byte including PF bit
+ *
+ *	Format up and transmit a link level command frame.
+ */
+
+static inline void gsm_command(struct gsm_mux *gsm, int addr, int control)
+{
+	gsm_send(gsm, addr, 1, control);
+}
+
+/* Data transmission */
+
+#define HDR_LEN		6	/* ADDR CTRL [LEN.2] DATA FCS */
+
+/**
+ *	gsm_data_alloc		-	allocate data frame
+ *	@gsm: GSM mux
+ *	@addr: DLCI address
+ *	@len: length excluding header and FCS
+ *	@ctrl: control byte
+ *
+ *	Allocate a new data buffer for sending frames with data. Space is left
+ *	at the front for header bytes but that is treated as an implementation
+ *	detail and not for the high level code to use
+ */
+
+static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
+								u8 ctrl)
+{
+	struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN,
+								GFP_ATOMIC);
+	if (m == NULL)
+		return NULL;
+	m->data = m->buffer + HDR_LEN - 1;	/* Allow for FCS */
+	m->len = len;
+	m->addr = addr;
+	m->ctrl = ctrl;
+	INIT_LIST_HEAD(&m->list);
+	return m;
+}
+
+/**
+ *	gsm_send_packet	-	sends a single packet
+ *	@gsm: GSM Mux
+ *	@msg: packet to send
+ *
+ *	The given packet is encoded and sent out. No memory is freed.
+ *	The caller must hold the gsm tx lock.
+ */
+static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg)
+{
+	int len, ret;
+
+
+	if (gsm->encoding == GSM_BASIC_OPT) {
+		gsm->txframe[0] = GSM0_SOF;
+		memcpy(gsm->txframe + 1, msg->data, msg->len);
+		gsm->txframe[msg->len + 1] = GSM0_SOF;
+		len = msg->len + 2;
+	} else {
+		gsm->txframe[0] = GSM1_SOF;
+		len = gsm_stuff_frame(msg->data, gsm->txframe + 1, msg->len);
+		gsm->txframe[len + 1] = GSM1_SOF;
+		len += 2;
+	}
+
+	if (debug & DBG_DATA)
+		gsm_hex_dump_bytes(__func__, gsm->txframe, len);
+	gsm_print_packet("-->", msg->addr, gsm->initiator, msg->ctrl, msg->data,
+			 msg->len);
+
+	ret = gsmld_output(gsm, gsm->txframe, len);
+	if (ret <= 0)
+		return ret;
+	/* FIXME: Can eliminate one SOF in many more cases */
+	gsm->tx_bytes -= msg->len;
+
+	return 0;
+}
+
+/**
+ *	gsm_is_flow_ctrl_msg	-	checks if flow control message
+ *	@msg: message to check
+ *
+ *	Returns true if the given message is a flow control command of the
+ *	control channel. False is returned in any other case.
+ */
+static bool gsm_is_flow_ctrl_msg(struct gsm_msg *msg)
+{
+	unsigned int cmd;
+
+	if (msg->addr > 0)
+		return false;
+
+	switch (msg->ctrl & ~PF) {
+	case UI:
+	case UIH:
+		cmd = 0;
+		if (gsm_read_ea_val(&cmd, msg->data + 2, msg->len - 2) < 1)
+			break;
+		switch (cmd & ~PF) {
+		case CMD_FCOFF:
+		case CMD_FCON:
+			return true;
+		}
+		break;
+	}
+
+	return false;
+}
+
+/**
+ *	gsm_data_kick	-	poke the queue
+ *	@gsm: GSM Mux
+ *
+ *	The tty device has called us to indicate that room has appeared in
+ *	the transmit queue. Ram more data into the pipe if we have any.
+ *	If we have been flow-stopped by a CMD_FCOFF, then we can only
+ *	send messages on DLCI0 until CMD_FCON. The caller must hold
+ *	the gsm tx lock.
+ */
+static int gsm_data_kick(struct gsm_mux *gsm)
+{
+	struct gsm_msg *msg, *nmsg;
+	struct gsm_dlci *dlci;
+	int ret;
+
+	clear_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
+
+	/* Serialize control messages and control channel messages first */
+	list_for_each_entry_safe(msg, nmsg, &gsm->tx_ctrl_list, list) {
+		if (gsm->constipated && !gsm_is_flow_ctrl_msg(msg))
+			continue;
+		ret = gsm_send_packet(gsm, msg);
+		switch (ret) {
+		case -ENOSPC:
+			return -ENOSPC;
+		case -ENODEV:
+			/* ldisc not open */
+			gsm->tx_bytes -= msg->len;
+			list_del(&msg->list);
+			kfree(msg);
+			continue;
+		default:
+			if (ret >= 0) {
+				list_del(&msg->list);
+				kfree(msg);
+			}
+			break;
+		}
+	}
+
+	if (gsm->constipated)
+		return -EAGAIN;
+
+	/* Serialize other channels */
+	if (list_empty(&gsm->tx_data_list))
+		return 0;
+	list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) {
+		dlci = gsm->dlci[msg->addr];
+		/* Send only messages for DLCIs with valid state */
+		if (dlci->state != DLCI_OPEN) {
+			gsm->tx_bytes -= msg->len;
+			list_del(&msg->list);
+			kfree(msg);
+			continue;
+		}
+		ret = gsm_send_packet(gsm, msg);
+		switch (ret) {
+		case -ENOSPC:
+			return -ENOSPC;
+		case -ENODEV:
+			/* ldisc not open */
+			gsm->tx_bytes -= msg->len;
+			list_del(&msg->list);
+			kfree(msg);
+			continue;
+		default:
+			if (ret >= 0) {
+				list_del(&msg->list);
+				kfree(msg);
+			}
+			break;
+		}
+	}
+
+	return 1;
+}
+
+/**
+ *	__gsm_data_queue		-	queue a UI or UIH frame
+ *	@dlci: DLCI sending the data
+ *	@msg: message queued
+ *
+ *	Add data to the transmit queue and try and get stuff moving
+ *	out of the mux tty if not already doing so. The Caller must hold
+ *	the gsm tx lock.
+ */
+
+static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	u8 *dp = msg->data;
+	u8 *fcs = dp + msg->len;
+
+	/* Fill in the header */
+	if (gsm->encoding == GSM_BASIC_OPT) {
+		if (msg->len < 128)
+			*--dp = (msg->len << 1) | EA;
+		else {
+			*--dp = (msg->len >> 7);	/* bits 7 - 15 */
+			*--dp = (msg->len & 127) << 1;	/* bits 0 - 6 */
+		}
+	}
+
+	*--dp = msg->ctrl;
+	if (gsm->initiator)
+		*--dp = (msg->addr << 2) | CR | EA;
+	else
+		*--dp = (msg->addr << 2) | EA;
+	*fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp);
+	/* Ugly protocol layering violation */
+	if (msg->ctrl == UI || msg->ctrl == (UI|PF))
+		*fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len);
+	*fcs = 0xFF - *fcs;
+
+	gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl,
+							msg->data, msg->len);
+
+	/* Move the header back and adjust the length, also allow for the FCS
+	   now tacked on the end */
+	msg->len += (msg->data - dp) + 1;
+	msg->data = dp;
+
+	/* Add to the actual output queue */
+	switch (msg->ctrl & ~PF) {
+	case UI:
+	case UIH:
+		if (msg->addr > 0) {
+			list_add_tail(&msg->list, &gsm->tx_data_list);
+			break;
+		}
+		fallthrough;
+	default:
+		list_add_tail(&msg->list, &gsm->tx_ctrl_list);
+		break;
+	}
+	gsm->tx_bytes += msg->len;
+
+	gsmld_write_trigger(gsm);
+	mod_timer(&gsm->kick_timer, jiffies + 10 * gsm->t1 * HZ / 100);
+}
+
+/**
+ *	gsm_data_queue		-	queue a UI or UIH frame
+ *	@dlci: DLCI sending the data
+ *	@msg: message queued
+ *
+ *	Add data to the transmit queue and try and get stuff moving
+ *	out of the mux tty if not already doing so. Take the
+ *	the gsm tx lock and dlci lock.
+ */
+
+static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
+	__gsm_data_queue(dlci, msg);
+	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
+}
+
+/**
+ *	gsm_dlci_data_output	-	try and push data out of a DLCI
+ *	@gsm: mux
+ *	@dlci: the DLCI to pull data from
+ *
+ *	Pull data from a DLCI and send it into the transmit queue if there
+ *	is data. Keep to the MRU of the mux. This path handles the usual tty
+ *	interface which is a byte stream with optional modem data.
+ *
+ *	Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
+{
+	struct gsm_msg *msg;
+	u8 *dp;
+	int h, len, size;
+
+	/* for modem bits without break data */
+	h = ((dlci->adaption == 1) ? 0 : 1);
+
+	len = kfifo_len(&dlci->fifo);
+	if (len == 0)
+		return 0;
+
+	/* MTU/MRU count only the data bits but watch adaption mode */
+	if ((len + h) > dlci->mtu)
+		len = dlci->mtu - h;
+
+	size = len + h;
+
+	msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype);
+	if (!msg)
+		return -ENOMEM;
+	dp = msg->data;
+	switch (dlci->adaption) {
+	case 1: /* Unstructured */
+		break;
+	case 2: /* Unstructured with modem bits.
+		 * Always one byte as we never send inline break data
+		 */
+		*dp++ = (gsm_encode_modem(dlci) << 1) | EA;
+		break;
+	default:
+		pr_err("%s: unsupported adaption %d\n", __func__,
+		       dlci->adaption);
+		break;
+	}
+
+	WARN_ON(len != kfifo_out_locked(&dlci->fifo, dp, len,
+		&dlci->lock));
+
+	/* Notify upper layer about available send space. */
+	tty_port_tty_wakeup(&dlci->port);
+
+	__gsm_data_queue(dlci, msg);
+	/* Bytes of data we used up */
+	return size;
+}
+
+/**
+ *	gsm_dlci_data_output_framed  -	try and push data out of a DLCI
+ *	@gsm: mux
+ *	@dlci: the DLCI to pull data from
+ *
+ *	Pull data from a DLCI and send it into the transmit queue if there
+ *	is data. Keep to the MRU of the mux. This path handles framed data
+ *	queued as skbuffs to the DLCI.
+ *
+ *	Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
+						struct gsm_dlci *dlci)
+{
+	struct gsm_msg *msg;
+	u8 *dp;
+	int len, size;
+	int last = 0, first = 0;
+	int overhead = 0;
+
+	/* One byte per frame is used for B/F flags */
+	if (dlci->adaption == 4)
+		overhead = 1;
+
+	/* dlci->skb is locked by tx_lock */
+	if (dlci->skb == NULL) {
+		dlci->skb = skb_dequeue_tail(&dlci->skb_list);
+		if (dlci->skb == NULL)
+			return 0;
+		first = 1;
+	}
+	len = dlci->skb->len + overhead;
+
+	/* MTU/MRU count only the data bits */
+	if (len > dlci->mtu) {
+		if (dlci->adaption == 3) {
+			/* Over long frame, bin it */
+			dev_kfree_skb_any(dlci->skb);
+			dlci->skb = NULL;
+			return 0;
+		}
+		len = dlci->mtu;
+	} else
+		last = 1;
+
+	size = len + overhead;
+	msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype);
+	if (msg == NULL) {
+		skb_queue_tail(&dlci->skb_list, dlci->skb);
+		dlci->skb = NULL;
+		return -ENOMEM;
+	}
+	dp = msg->data;
+
+	if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */
+		/* Flag byte to carry the start/end info */
+		*dp++ = last << 7 | first << 6 | 1;	/* EA */
+		len--;
+	}
+	memcpy(dp, dlci->skb->data, len);
+	skb_pull(dlci->skb, len);
+	__gsm_data_queue(dlci, msg);
+	if (last) {
+		dev_kfree_skb_any(dlci->skb);
+		dlci->skb = NULL;
+	}
+	return size;
+}
+
+/**
+ *	gsm_dlci_modem_output	-	try and push modem status out of a DLCI
+ *	@gsm: mux
+ *	@dlci: the DLCI to pull modem status from
+ *	@brk: break signal
+ *
+ *	Push an empty frame in to the transmit queue to update the modem status
+ *	bits and to transmit an optional break.
+ *
+ *	Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci,
+				 u8 brk)
+{
+	u8 *dp = NULL;
+	struct gsm_msg *msg;
+	int size = 0;
+
+	/* for modem bits without break data */
+	switch (dlci->adaption) {
+	case 1: /* Unstructured */
+		break;
+	case 2: /* Unstructured with modem bits. */
+		size++;
+		if (brk > 0)
+			size++;
+		break;
+	default:
+		pr_err("%s: unsupported adaption %d\n", __func__,
+		       dlci->adaption);
+		return -EINVAL;
+	}
+
+	msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype);
+	if (!msg) {
+		pr_err("%s: gsm_data_alloc error", __func__);
+		return -ENOMEM;
+	}
+	dp = msg->data;
+	switch (dlci->adaption) {
+	case 1: /* Unstructured */
+		break;
+	case 2: /* Unstructured with modem bits. */
+		if (brk == 0) {
+			*dp++ = (gsm_encode_modem(dlci) << 1) | EA;
+		} else {
+			*dp++ = gsm_encode_modem(dlci) << 1;
+			*dp++ = (brk << 4) | 2 | EA; /* Length, Break, EA */
+		}
+		break;
+	default:
+		/* Handled above */
+		break;
+	}
+
+	__gsm_data_queue(dlci, msg);
+	return size;
+}
+
+/**
+ *	gsm_dlci_data_sweep		-	look for data to send
+ *	@gsm: the GSM mux
+ *
+ *	Sweep the GSM mux channels in priority order looking for ones with
+ *	data to send. We could do with optimising this scan a bit. We aim
+ *	to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit
+ *	TX_THRESH_LO we get called again
+ *
+ *	FIXME: We should round robin between groups and in theory you can
+ *	renegotiate DLCI priorities with optional stuff. Needs optimising.
+ */
+
+static int gsm_dlci_data_sweep(struct gsm_mux *gsm)
+{
+	/* Priority ordering: We should do priority with RR of the groups */
+	int i, len, ret = 0;
+	bool sent;
+	struct gsm_dlci *dlci;
+
+	while (gsm->tx_bytes < TX_THRESH_HI) {
+		for (sent = false, i = 1; i < NUM_DLCI; i++) {
+			dlci = gsm->dlci[i];
+			/* skip unused or blocked channel */
+			if (!dlci || dlci->constipated)
+				continue;
+			/* skip channels with invalid state */
+			if (dlci->state != DLCI_OPEN)
+				continue;
+			/* count the sent data per adaption */
+			if (dlci->adaption < 3 && !dlci->net)
+				len = gsm_dlci_data_output(gsm, dlci);
+			else
+				len = gsm_dlci_data_output_framed(gsm, dlci);
+			/* on error exit */
+			if (len < 0)
+				return ret;
+			if (len > 0) {
+				ret++;
+				sent = true;
+				/* The lower DLCs can starve the higher DLCs! */
+				break;
+			}
+			/* try next */
+		}
+		if (!sent)
+			break;
+	}
+
+	return ret;
+}
+
+/**
+ *	gsm_dlci_data_kick	-	transmit if possible
+ *	@dlci: DLCI to kick
+ *
+ *	Transmit data from this DLCI if the queue is empty. We can't rely on
+ *	a tty wakeup except when we filled the pipe so we need to fire off
+ *	new data ourselves in other cases.
+ */
+
+static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
+{
+	unsigned long flags;
+	int sweep;
+
+	if (dlci->constipated)
+		return;
+
+	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
+	/* If we have nothing running then we need to fire up */
+	sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
+	if (dlci->gsm->tx_bytes == 0) {
+		if (dlci->net)
+			gsm_dlci_data_output_framed(dlci->gsm, dlci);
+		else
+			gsm_dlci_data_output(dlci->gsm, dlci);
+	}
+	if (sweep)
+		gsm_dlci_data_sweep(dlci->gsm);
+	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
+}
+
+/*
+ *	Control message processing
+ */
+
+
+/**
+ * gsm_control_command	-	send a command frame to a control
+ * @gsm: gsm channel
+ * @cmd: the command to use
+ * @data: data to follow encoded info
+ * @dlen: length of data
+ *
+ * Encode up and queue a UI/UIH frame containing our command.
+ */
+static int gsm_control_command(struct gsm_mux *gsm, int cmd, const u8 *data,
+			       int dlen)
+{
+	struct gsm_msg *msg;
+	struct gsm_dlci *dlci = gsm->dlci[0];
+
+	msg = gsm_data_alloc(gsm, 0, dlen + 2, dlci->ftype);
+	if (msg == NULL)
+		return -ENOMEM;
+
+	msg->data[0] = (cmd << 1) | CR | EA;	/* Set C/R */
+	msg->data[1] = (dlen << 1) | EA;
+	memcpy(msg->data + 2, data, dlen);
+	gsm_data_queue(dlci, msg);
+
+	return 0;
+}
+
+/**
+ *	gsm_control_reply	-	send a response frame to a control
+ *	@gsm: gsm channel
+ *	@cmd: the command to use
+ *	@data: data to follow encoded info
+ *	@dlen: length of data
+ *
+ *	Encode up and queue a UI/UIH frame containing our response.
+ */
+
+static void gsm_control_reply(struct gsm_mux *gsm, int cmd, const u8 *data,
+					int dlen)
+{
+	struct gsm_msg *msg;
+	struct gsm_dlci *dlci = gsm->dlci[0];
+
+	msg = gsm_data_alloc(gsm, 0, dlen + 2, dlci->ftype);
+	if (msg == NULL)
+		return;
+	msg->data[0] = (cmd & 0xFE) << 1 | EA;	/* Clear C/R */
+	msg->data[1] = (dlen << 1) | EA;
+	memcpy(msg->data + 2, data, dlen);
+	gsm_data_queue(dlci, msg);
+}
+
+/**
+ *	gsm_process_modem	-	process received modem status
+ *	@tty: virtual tty bound to the DLCI
+ *	@dlci: DLCI to affect
+ *	@modem: modem bits (full EA)
+ *	@slen: number of signal octets
+ *
+ *	Used when a modem control message or line state inline in adaption
+ *	layer 2 is processed. Sort out the local modem state and throttles
+ */
+
+static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
+							u32 modem, int slen)
+{
+	int  mlines = 0;
+	u8 brk = 0;
+	int fc;
+
+	/* The modem status command can either contain one octet (V.24 signals)
+	 * or two octets (V.24 signals + break signals). This is specified in
+	 * section 5.4.6.3.7 of the 07.10 mux spec.
+	 */
+
+	if (slen == 1)
+		modem = modem & 0x7f;
+	else {
+		brk = modem & 0x7f;
+		modem = (modem >> 7) & 0x7f;
+	}
+
+	/* Flow control/ready to communicate */
+	fc = (modem & MDM_FC) || !(modem & MDM_RTR);
+	if (fc && !dlci->constipated) {
+		/* Need to throttle our output on this device */
+		dlci->constipated = true;
+	} else if (!fc && dlci->constipated) {
+		dlci->constipated = false;
+		gsm_dlci_data_kick(dlci);
+	}
+
+	/* Map modem bits */
+	if (modem & MDM_RTC)
+		mlines |= TIOCM_DSR | TIOCM_DTR;
+	if (modem & MDM_RTR)
+		mlines |= TIOCM_RTS | TIOCM_CTS;
+	if (modem & MDM_IC)
+		mlines |= TIOCM_RI;
+	if (modem & MDM_DV)
+		mlines |= TIOCM_CD;
+
+	/* Carrier drop -> hangup */
+	if (tty) {
+		if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD))
+			if (!C_CLOCAL(tty))
+				tty_hangup(tty);
+	}
+	if (brk & 0x01)
+		tty_insert_flip_char(&dlci->port, 0, TTY_BREAK);
+	dlci->modem_rx = mlines;
+	wake_up_interruptible(&dlci->gsm->event);
+}
+
+/**
+ * gsm_process_negotiation	-	process received parameters
+ * @gsm: GSM channel
+ * @addr: DLCI address
+ * @cr: command/response
+ * @params: encoded parameters from the parameter negotiation message
+ *
+ * Used when the response for our parameter negotiation command was
+ * received.
+ */
+static int gsm_process_negotiation(struct gsm_mux *gsm, unsigned int addr,
+				   unsigned int cr,
+				   const struct gsm_dlci_param_bits *params)
+{
+	struct gsm_dlci *dlci = gsm->dlci[addr];
+	unsigned int ftype, i, adaption, prio, n1, k;
+
+	i = FIELD_GET(PN_I_CL_FIELD_FTYPE, params->i_cl_bits);
+	adaption = FIELD_GET(PN_I_CL_FIELD_ADAPTION, params->i_cl_bits) + 1;
+	prio = FIELD_GET(PN_P_FIELD_PRIO, params->p_bits);
+	n1 = FIELD_GET(PN_N_FIELD_N1, get_unaligned_le16(&params->n_bits));
+	k = FIELD_GET(PN_K_FIELD_K, params->k_bits);
+
+	if (n1 < MIN_MTU) {
+		if (debug & DBG_ERRORS)
+			pr_info("%s N1 out of range in PN\n", __func__);
+		return -EINVAL;
+	}
+
+	switch (i) {
+	case 0x00:
+		ftype = UIH;
+		break;
+	case 0x01:
+		ftype = UI;
+		break;
+	case 0x02: /* I frames are not supported */
+		if (debug & DBG_ERRORS)
+			pr_info("%s unsupported I frame request in PN\n",
+				__func__);
+		gsm->unsupported++;
+		return -EINVAL;
+	default:
+		if (debug & DBG_ERRORS)
+			pr_info("%s i out of range in PN\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!cr && gsm->initiator) {
+		if (adaption != dlci->adaption) {
+			if (debug & DBG_ERRORS)
+				pr_info("%s invalid adaption %d in PN\n",
+					__func__, adaption);
+			return -EINVAL;
+		}
+		if (prio != dlci->prio) {
+			if (debug & DBG_ERRORS)
+				pr_info("%s invalid priority %d in PN",
+					__func__, prio);
+			return -EINVAL;
+		}
+		if (n1 > gsm->mru || n1 > dlci->mtu) {
+			/* We requested a frame size but the other party wants
+			 * to send larger frames. The standard allows only a
+			 * smaller response value than requested (5.4.6.3.1).
+			 */
+			if (debug & DBG_ERRORS)
+				pr_info("%s invalid N1 %d in PN\n", __func__,
+					n1);
+			return -EINVAL;
+		}
+		dlci->mtu = n1;
+		if (ftype != dlci->ftype) {
+			if (debug & DBG_ERRORS)
+				pr_info("%s invalid i %d in PN\n", __func__, i);
+			return -EINVAL;
+		}
+		if (ftype != UI && ftype != UIH && k > dlci->k) {
+			if (debug & DBG_ERRORS)
+				pr_info("%s invalid k %d in PN\n", __func__, k);
+			return -EINVAL;
+		}
+		dlci->k = k;
+	} else if (cr && !gsm->initiator) {
+		/* Only convergence layer type 1 and 2 are supported. */
+		if (adaption != 1 && adaption != 2) {
+			if (debug & DBG_ERRORS)
+				pr_info("%s invalid adaption %d in PN\n",
+					__func__, adaption);
+			return -EINVAL;
+		}
+		dlci->adaption = adaption;
+		if (n1 > gsm->mru) {
+			/* Propose a smaller value */
+			dlci->mtu = gsm->mru;
+		} else if (n1 > MAX_MTU) {
+			/* Propose a smaller value */
+			dlci->mtu = MAX_MTU;
+		} else {
+			dlci->mtu = n1;
+		}
+		dlci->prio = prio;
+		dlci->ftype = ftype;
+		dlci->k = k;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ *	gsm_control_modem	-	modem status received
+ *	@gsm: GSM channel
+ *	@data: data following command
+ *	@clen: command length
+ *
+ *	We have received a modem status control message. This is used by
+ *	the GSM mux protocol to pass virtual modem line status and optionally
+ *	to indicate break signals. Unpack it, convert to Linux representation
+ *	and if need be stuff a break message down the tty.
+ */
+
+static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen)
+{
+	unsigned int addr = 0;
+	unsigned int modem = 0;
+	struct gsm_dlci *dlci;
+	int len = clen;
+	int cl = clen;
+	const u8 *dp = data;
+	struct tty_struct *tty;
+
+	len = gsm_read_ea_val(&addr, data, cl);
+	if (len < 1)
+		return;
+
+	addr >>= 1;
+	/* Closed port, or invalid ? */
+	if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
+		return;
+	dlci = gsm->dlci[addr];
+
+	/* Must be at least one byte following the EA */
+	if ((cl - len) < 1)
+		return;
+
+	dp += len;
+	cl -= len;
+
+	/* get the modem status */
+	len = gsm_read_ea_val(&modem, dp, cl);
+	if (len < 1)
+		return;
+
+	tty = tty_port_tty_get(&dlci->port);
+	gsm_process_modem(tty, dlci, modem, cl);
+	if (tty) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
+	}
+	gsm_control_reply(gsm, CMD_MSC, data, clen);
+}
+
+/**
+ * gsm_control_negotiation	-	parameter negotiation received
+ * @gsm: GSM channel
+ * @cr: command/response flag
+ * @data: data following command
+ * @dlen: data length
+ *
+ * We have received a parameter negotiation message. This is used by
+ * the GSM mux protocol to configure protocol parameters for a new DLCI.
+ */
+static void gsm_control_negotiation(struct gsm_mux *gsm, unsigned int cr,
+				    const u8 *data, unsigned int dlen)
+{
+	unsigned int addr;
+	struct gsm_dlci_param_bits pn_reply;
+	struct gsm_dlci *dlci;
+	struct gsm_dlci_param_bits *params;
+
+	if (dlen < sizeof(struct gsm_dlci_param_bits)) {
+		gsm->open_error++;
+		return;
+	}
+
+	/* Invalid DLCI? */
+	params = (struct gsm_dlci_param_bits *)data;
+	addr = FIELD_GET(PN_D_FIELD_DLCI, params->d_bits);
+	if (addr == 0 || addr >= NUM_DLCI || !gsm->dlci[addr]) {
+		gsm->open_error++;
+		return;
+	}
+	dlci = gsm->dlci[addr];
+
+	/* Too late for parameter negotiation? */
+	if ((!cr && dlci->state == DLCI_OPENING) || dlci->state == DLCI_OPEN) {
+		gsm->open_error++;
+		return;
+	}
+
+	/* Process the received parameters */
+	if (gsm_process_negotiation(gsm, addr, cr, params) != 0) {
+		/* Negotiation failed. Close the link. */
+		if (debug & DBG_ERRORS)
+			pr_info("%s PN failed\n", __func__);
+		gsm->open_error++;
+		gsm_dlci_close(dlci);
+		return;
+	}
+
+	if (cr) {
+		/* Reply command with accepted parameters. */
+		if (gsm_encode_params(dlci, &pn_reply) == 0)
+			gsm_control_reply(gsm, CMD_PN, (const u8 *)&pn_reply,
+					  sizeof(pn_reply));
+		else if (debug & DBG_ERRORS)
+			pr_info("%s PN invalid\n", __func__);
+	} else if (dlci->state == DLCI_CONFIGURE) {
+		/* Proceed with link setup by sending SABM before UA */
+		dlci->state = DLCI_OPENING;
+		gsm_command(gsm, dlci->addr, SABM|PF);
+		mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+	} else {
+		if (debug & DBG_ERRORS)
+			pr_info("%s PN in invalid state\n", __func__);
+		gsm->open_error++;
+	}
+}
+
+/**
+ *	gsm_control_rls		-	remote line status
+ *	@gsm: GSM channel
+ *	@data: data bytes
+ *	@clen: data length
+ *
+ *	The modem sends us a two byte message on the control channel whenever
+ *	it wishes to send us an error state from the virtual link. Stuff
+ *	this into the uplink tty if present
+ */
+
+static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen)
+{
+	struct tty_port *port;
+	unsigned int addr = 0;
+	u8 bits;
+	int len = clen;
+	const u8 *dp = data;
+
+	while (gsm_read_ea(&addr, *dp++) == 0) {
+		len--;
+		if (len == 0)
+			return;
+	}
+	/* Must be at least one byte following ea */
+	len--;
+	if (len <= 0)
+		return;
+	addr >>= 1;
+	/* Closed port, or invalid ? */
+	if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
+		return;
+	/* No error ? */
+	bits = *dp;
+	if ((bits & 1) == 0)
+		return;
+
+	port = &gsm->dlci[addr]->port;
+
+	if (bits & 2)
+		tty_insert_flip_char(port, 0, TTY_OVERRUN);
+	if (bits & 4)
+		tty_insert_flip_char(port, 0, TTY_PARITY);
+	if (bits & 8)
+		tty_insert_flip_char(port, 0, TTY_FRAME);
+
+	tty_flip_buffer_push(port);
+
+	gsm_control_reply(gsm, CMD_RLS, data, clen);
+}
+
+static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
+
+/**
+ *	gsm_control_message	-	DLCI 0 control processing
+ *	@gsm: our GSM mux
+ *	@command:  the command EA
+ *	@data: data beyond the command/length EAs
+ *	@clen: length
+ *
+ *	Input processor for control messages from the other end of the link.
+ *	Processes the incoming request and queues a response frame or an
+ *	NSC response if not supported
+ */
+
+static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
+						const u8 *data, int clen)
+{
+	u8 buf[1];
+
+	switch (command) {
+	case CMD_CLD: {
+		struct gsm_dlci *dlci = gsm->dlci[0];
+		/* Modem wishes to close down */
+		if (dlci) {
+			dlci->dead = true;
+			gsm->dead = true;
+			gsm_dlci_begin_close(dlci);
+		}
+		}
+		break;
+	case CMD_TEST:
+		/* Modem wishes to test, reply with the data */
+		gsm_control_reply(gsm, CMD_TEST, data, clen);
+		break;
+	case CMD_FCON:
+		/* Modem can accept data again */
+		gsm->constipated = false;
+		gsm_control_reply(gsm, CMD_FCON, NULL, 0);
+		/* Kick the link in case it is idling */
+		gsmld_write_trigger(gsm);
+		break;
+	case CMD_FCOFF:
+		/* Modem wants us to STFU */
+		gsm->constipated = true;
+		gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
+		break;
+	case CMD_MSC:
+		/* Out of band modem line change indicator for a DLCI */
+		gsm_control_modem(gsm, data, clen);
+		break;
+	case CMD_RLS:
+		/* Out of band error reception for a DLCI */
+		gsm_control_rls(gsm, data, clen);
+		break;
+	case CMD_PSC:
+		/* Modem wishes to enter power saving state */
+		gsm_control_reply(gsm, CMD_PSC, NULL, 0);
+		break;
+		/* Optional commands */
+	case CMD_PN:
+		/* Modem sends a parameter negotiation command */
+		gsm_control_negotiation(gsm, 1, data, clen);
+		break;
+		/* Optional unsupported commands */
+	case CMD_RPN:	/* Remote port negotiation */
+	case CMD_SNC:	/* Service negotiation command */
+		gsm->unsupported++;
+		fallthrough;
+	default:
+		/* Reply to bad commands with an NSC */
+		buf[0] = command;
+		gsm_control_reply(gsm, CMD_NSC, buf, 1);
+		break;
+	}
+}
+
+/**
+ *	gsm_control_response	-	process a response to our control
+ *	@gsm: our GSM mux
+ *	@command: the command (response) EA
+ *	@data: data beyond the command/length EA
+ *	@clen: length
+ *
+ *	Process a response to an outstanding command. We only allow a single
+ *	control message in flight so this is fairly easy. All the clean up
+ *	is done by the caller, we just update the fields, flag it as done
+ *	and return
+ */
+
+static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
+						const u8 *data, int clen)
+{
+	struct gsm_control *ctrl;
+	struct gsm_dlci *dlci;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gsm->control_lock, flags);
+
+	ctrl = gsm->pending_cmd;
+	dlci = gsm->dlci[0];
+	command |= 1;
+	/* Does the reply match our command */
+	if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) {
+		/* Our command was replied to, kill the retry timer */
+		del_timer(&gsm->t2_timer);
+		gsm->pending_cmd = NULL;
+		/* Rejected by the other end */
+		if (command == CMD_NSC)
+			ctrl->error = -EOPNOTSUPP;
+		ctrl->done = 1;
+		wake_up(&gsm->event);
+	/* Or did we receive the PN response to our PN command */
+	} else if (command == CMD_PN) {
+		gsm_control_negotiation(gsm, 0, data, clen);
+	/* Or did we receive the TEST response to our TEST command */
+	} else if (command == CMD_TEST && clen == 1 && *data == gsm->ka_num) {
+		gsm->ka_retries = -1; /* trigger new keep-alive message */
+		if (dlci && !dlci->dead)
+			mod_timer(&gsm->ka_timer, jiffies + gsm->keep_alive * HZ / 100);
+	}
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ * gsm_control_keep_alive	-	check timeout or start keep-alive
+ * @t: timer contained in our gsm object
+ *
+ * Called off the keep-alive timer expiry signaling that our link
+ * partner is not responding anymore. Link will be closed.
+ * This is also called to startup our timer.
+ */
+
+static void gsm_control_keep_alive(struct timer_list *t)
+{
+	struct gsm_mux *gsm = from_timer(gsm, t, ka_timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&gsm->control_lock, flags);
+	if (gsm->ka_num && gsm->ka_retries == 0) {
+		/* Keep-alive expired -> close the link */
+		if (debug & DBG_ERRORS)
+			pr_debug("%s keep-alive timed out\n", __func__);
+		spin_unlock_irqrestore(&gsm->control_lock, flags);
+		if (gsm->dlci[0])
+			gsm_dlci_begin_close(gsm->dlci[0]);
+		return;
+	} else if (gsm->keep_alive && gsm->dlci[0] && !gsm->dlci[0]->dead) {
+		if (gsm->ka_retries > 0) {
+			/* T2 expired for keep-alive -> resend */
+			gsm->ka_retries--;
+		} else {
+			/* Start keep-alive timer */
+			gsm->ka_num++;
+			if (!gsm->ka_num)
+				gsm->ka_num++;
+			gsm->ka_retries = (signed int)gsm->n2;
+		}
+		gsm_control_command(gsm, CMD_TEST, &gsm->ka_num,
+				    sizeof(gsm->ka_num));
+		mod_timer(&gsm->ka_timer,
+			  jiffies + gsm->t2 * HZ / 100);
+	}
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ *	gsm_control_transmit	-	send control packet
+ *	@gsm: gsm mux
+ *	@ctrl: frame to send
+ *
+ *	Send out a pending control command (called under control lock)
+ */
+
+static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl)
+{
+	gsm_control_command(gsm, ctrl->cmd, ctrl->data, ctrl->len);
+}
+
+/**
+ *	gsm_control_retransmit	-	retransmit a control frame
+ *	@t: timer contained in our gsm object
+ *
+ *	Called off the T2 timer expiry in order to retransmit control frames
+ *	that have been lost in the system somewhere. The control_lock protects
+ *	us from colliding with another sender or a receive completion event.
+ *	In that situation the timer may still occur in a small window but
+ *	gsm->pending_cmd will be NULL and we just let the timer expire.
+ */
+
+static void gsm_control_retransmit(struct timer_list *t)
+{
+	struct gsm_mux *gsm = from_timer(gsm, t, t2_timer);
+	struct gsm_control *ctrl;
+	unsigned long flags;
+	spin_lock_irqsave(&gsm->control_lock, flags);
+	ctrl = gsm->pending_cmd;
+	if (ctrl) {
+		if (gsm->cretries == 0 || !gsm->dlci[0] || gsm->dlci[0]->dead) {
+			gsm->pending_cmd = NULL;
+			ctrl->error = -ETIMEDOUT;
+			ctrl->done = 1;
+			spin_unlock_irqrestore(&gsm->control_lock, flags);
+			wake_up(&gsm->event);
+			return;
+		}
+		gsm->cretries--;
+		gsm_control_transmit(gsm, ctrl);
+		mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
+	}
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ *	gsm_control_send	-	send a control frame on DLCI 0
+ *	@gsm: the GSM channel
+ *	@command: command  to send including CR bit
+ *	@data: bytes of data (must be kmalloced)
+ *	@clen: length of the block to send
+ *
+ *	Queue and dispatch a control command. Only one command can be
+ *	active at a time. In theory more can be outstanding but the matching
+ *	gets really complicated so for now stick to one outstanding.
+ */
+
+static struct gsm_control *gsm_control_send(struct gsm_mux *gsm,
+		unsigned int command, u8 *data, int clen)
+{
+	struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control),
+						GFP_ATOMIC);
+	unsigned long flags;
+	if (ctrl == NULL)
+		return NULL;
+retry:
+	wait_event(gsm->event, gsm->pending_cmd == NULL);
+	spin_lock_irqsave(&gsm->control_lock, flags);
+	if (gsm->pending_cmd != NULL) {
+		spin_unlock_irqrestore(&gsm->control_lock, flags);
+		goto retry;
+	}
+	ctrl->cmd = command;
+	ctrl->data = data;
+	ctrl->len = clen;
+	gsm->pending_cmd = ctrl;
+
+	/* If DLCI0 is in ADM mode skip retries, it won't respond */
+	if (gsm->dlci[0]->mode == DLCI_MODE_ADM)
+		gsm->cretries = 0;
+	else
+		gsm->cretries = gsm->n2;
+
+	mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
+	gsm_control_transmit(gsm, ctrl);
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+	return ctrl;
+}
+
+/**
+ *	gsm_control_wait	-	wait for a control to finish
+ *	@gsm: GSM mux
+ *	@control: control we are waiting on
+ *
+ *	Waits for the control to complete or time out. Frees any used
+ *	resources and returns 0 for success, or an error if the remote
+ *	rejected or ignored the request.
+ */
+
+static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
+{
+	int err;
+	wait_event(gsm->event, control->done == 1);
+	err = control->error;
+	kfree(control);
+	return err;
+}
+
+
+/*
+ *	DLCI level handling: Needs krefs
+ */
+
+/*
+ *	State transitions and timers
+ */
+
+/**
+ *	gsm_dlci_close		-	a DLCI has closed
+ *	@dlci: DLCI that closed
+ *
+ *	Perform processing when moving a DLCI into closed state. If there
+ *	is an attached tty this is hung up
+ */
+
+static void gsm_dlci_close(struct gsm_dlci *dlci)
+{
+	del_timer(&dlci->t1);
+	if (debug & DBG_ERRORS)
+		pr_debug("DLCI %d goes closed.\n", dlci->addr);
+	dlci->state = DLCI_CLOSED;
+	/* Prevent us from sending data before the link is up again */
+	dlci->constipated = true;
+	if (dlci->addr != 0) {
+		tty_port_tty_hangup(&dlci->port, false);
+		gsm_dlci_clear_queues(dlci->gsm, dlci);
+		/* Ensure that gsmtty_open() can return. */
+		tty_port_set_initialized(&dlci->port, false);
+		wake_up_interruptible(&dlci->port.open_wait);
+	} else {
+		del_timer(&dlci->gsm->ka_timer);
+		dlci->gsm->dead = true;
+	}
+	/* A DLCI 0 close is a MUX termination so we need to kick that
+	   back to userspace somehow */
+	gsm_dlci_data_kick(dlci);
+	wake_up_all(&dlci->gsm->event);
+}
+
+/**
+ *	gsm_dlci_open		-	a DLCI has opened
+ *	@dlci: DLCI that opened
+ *
+ *	Perform processing when moving a DLCI into open state.
+ */
+
+static void gsm_dlci_open(struct gsm_dlci *dlci)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+
+	/* Note that SABM UA .. SABM UA first UA lost can mean that we go
+	   open -> open */
+	del_timer(&dlci->t1);
+	/* This will let a tty open continue */
+	dlci->state = DLCI_OPEN;
+	dlci->constipated = false;
+	if (debug & DBG_ERRORS)
+		pr_debug("DLCI %d goes open.\n", dlci->addr);
+	/* Send current modem state */
+	if (dlci->addr) {
+		gsm_modem_update(dlci, 0);
+	} else {
+		/* Start keep-alive control */
+		gsm->ka_num = 0;
+		gsm->ka_retries = -1;
+		mod_timer(&gsm->ka_timer,
+			  jiffies + gsm->keep_alive * HZ / 100);
+	}
+	gsm_dlci_data_kick(dlci);
+	wake_up(&dlci->gsm->event);
+}
+
+/**
+ * gsm_dlci_negotiate	-	start parameter negotiation
+ * @dlci: DLCI to open
+ *
+ * Starts the parameter negotiation for the new DLCI. This needs to be done
+ * before the DLCI initialized the channel via SABM.
+ */
+static int gsm_dlci_negotiate(struct gsm_dlci *dlci)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	struct gsm_dlci_param_bits params;
+	int ret;
+
+	ret = gsm_encode_params(dlci, &params);
+	if (ret != 0)
+		return ret;
+
+	/* We cannot asynchronous wait for the command response with
+	 * gsm_command() and gsm_control_wait() at this point.
+	 */
+	ret = gsm_control_command(gsm, CMD_PN, (const u8 *)&params,
+				  sizeof(params));
+
+	return ret;
+}
+
+/**
+ *	gsm_dlci_t1		-	T1 timer expiry
+ *	@t: timer contained in the DLCI that opened
+ *
+ *	The T1 timer handles retransmits of control frames (essentially of
+ *	SABM and DISC). We resend the command until the retry count runs out
+ *	in which case an opening port goes back to closed and a closing port
+ *	is simply put into closed state (any further frames from the other
+ *	end will get a DM response)
+ *
+ *	Some control dlci can stay in ADM mode with other dlci working just
+ *	fine. In that case we can just keep the control dlci open after the
+ *	DLCI_OPENING retries time out.
+ */
+
+static void gsm_dlci_t1(struct timer_list *t)
+{
+	struct gsm_dlci *dlci = from_timer(dlci, t, t1);
+	struct gsm_mux *gsm = dlci->gsm;
+
+	switch (dlci->state) {
+	case DLCI_CONFIGURE:
+		if (dlci->retries && gsm_dlci_negotiate(dlci) == 0) {
+			dlci->retries--;
+			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+		} else {
+			gsm->open_error++;
+			gsm_dlci_begin_close(dlci); /* prevent half open link */
+		}
+		break;
+	case DLCI_OPENING:
+		if (dlci->retries) {
+			dlci->retries--;
+			gsm_command(dlci->gsm, dlci->addr, SABM|PF);
+			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+		} else if (!dlci->addr && gsm->control == (DM | PF)) {
+			if (debug & DBG_ERRORS)
+				pr_info("DLCI %d opening in ADM mode.\n",
+					dlci->addr);
+			dlci->mode = DLCI_MODE_ADM;
+			gsm_dlci_open(dlci);
+		} else {
+			gsm->open_error++;
+			gsm_dlci_begin_close(dlci); /* prevent half open link */
+		}
+
+		break;
+	case DLCI_CLOSING:
+		if (dlci->retries) {
+			dlci->retries--;
+			gsm_command(dlci->gsm, dlci->addr, DISC|PF);
+			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+		} else
+			gsm_dlci_close(dlci);
+		break;
+	default:
+		pr_debug("%s: unhandled state: %d\n", __func__, dlci->state);
+		break;
+	}
+}
+
+/**
+ *	gsm_dlci_begin_open	-	start channel open procedure
+ *	@dlci: DLCI to open
+ *
+ *	Commence opening a DLCI from the Linux side. We issue SABM messages
+ *	to the modem which should then reply with a UA or ADM, at which point
+ *	we will move into open state. Opening is done asynchronously with retry
+ *	running off timers and the responses.
+ *	Parameter negotiation is performed before SABM if required.
+ */
+
+static void gsm_dlci_begin_open(struct gsm_dlci *dlci)
+{
+	struct gsm_mux *gsm = dlci ? dlci->gsm : NULL;
+	bool need_pn = false;
+
+	if (!gsm)
+		return;
+
+	if (dlci->addr != 0) {
+		if (gsm->adaption != 1 || gsm->adaption != dlci->adaption)
+			need_pn = true;
+		if (dlci->prio != (roundup(dlci->addr + 1, 8) - 1))
+			need_pn = true;
+		if (gsm->ftype != dlci->ftype)
+			need_pn = true;
+	}
+
+	switch (dlci->state) {
+	case DLCI_CLOSED:
+	case DLCI_WAITING_CONFIG:
+	case DLCI_CLOSING:
+		dlci->retries = gsm->n2;
+		if (!need_pn) {
+			dlci->state = DLCI_OPENING;
+			gsm_command(gsm, dlci->addr, SABM|PF);
+		} else {
+			/* Configure DLCI before setup */
+			dlci->state = DLCI_CONFIGURE;
+			if (gsm_dlci_negotiate(dlci) != 0) {
+				gsm_dlci_close(dlci);
+				return;
+			}
+		}
+		mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+		break;
+	default:
+		break;
+	}
+}
+
+/**
+ *	gsm_dlci_set_opening	-	change state to opening
+ *	@dlci: DLCI to open
+ *
+ *	Change internal state to wait for DLCI open from initiator side.
+ *	We set off timers and responses upon reception of an SABM.
+ */
+static void gsm_dlci_set_opening(struct gsm_dlci *dlci)
+{
+	switch (dlci->state) {
+	case DLCI_CLOSED:
+	case DLCI_WAITING_CONFIG:
+	case DLCI_CLOSING:
+		dlci->state = DLCI_OPENING;
+		break;
+	default:
+		break;
+	}
+}
+
+/**
+ * gsm_dlci_set_wait_config	-	wait for channel configuration
+ * @dlci: DLCI to configure
+ *
+ * Wait for a DLCI configuration from the application.
+ */
+static void gsm_dlci_set_wait_config(struct gsm_dlci *dlci)
+{
+	switch (dlci->state) {
+	case DLCI_CLOSED:
+	case DLCI_CLOSING:
+		dlci->state = DLCI_WAITING_CONFIG;
+		break;
+	default:
+		break;
+	}
+}
+
+/**
+ *	gsm_dlci_begin_close	-	start channel open procedure
+ *	@dlci: DLCI to open
+ *
+ *	Commence closing a DLCI from the Linux side. We issue DISC messages
+ *	to the modem which should then reply with a UA, at which point we
+ *	will move into closed state. Closing is done asynchronously with retry
+ *	off timers. We may also receive a DM reply from the other end which
+ *	indicates the channel was already closed.
+ */
+
+static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING)
+		return;
+	dlci->retries = gsm->n2;
+	dlci->state = DLCI_CLOSING;
+	gsm_command(dlci->gsm, dlci->addr, DISC|PF);
+	mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+	wake_up_interruptible(&gsm->event);
+}
+
+/**
+ *	gsm_dlci_data		-	data arrived
+ *	@dlci: channel
+ *	@data: block of bytes received
+ *	@clen: length of received block
+ *
+ *	A UI or UIH frame has arrived which contains data for a channel
+ *	other than the control channel. If the relevant virtual tty is
+ *	open we shovel the bits down it, if not we drop them.
+ */
+
+static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
+{
+	/* krefs .. */
+	struct tty_port *port = &dlci->port;
+	struct tty_struct *tty;
+	unsigned int modem = 0;
+	int len;
+
+	if (debug & DBG_TTY)
+		pr_debug("%d bytes for tty\n", clen);
+	switch (dlci->adaption)  {
+	/* Unsupported types */
+	case 4:		/* Packetised interruptible data */
+		break;
+	case 3:		/* Packetised uininterruptible voice/data */
+		break;
+	case 2:		/* Asynchronous serial with line state in each frame */
+		len = gsm_read_ea_val(&modem, data, clen);
+		if (len < 1)
+			return;
+		tty = tty_port_tty_get(port);
+		if (tty) {
+			gsm_process_modem(tty, dlci, modem, len);
+			tty_wakeup(tty);
+			tty_kref_put(tty);
+		}
+		/* Skip processed modem data */
+		data += len;
+		clen -= len;
+		fallthrough;
+	case 1:		/* Line state will go via DLCI 0 controls only */
+	default:
+		tty_insert_flip_string(port, data, clen);
+		tty_flip_buffer_push(port);
+	}
+}
+
+/**
+ *	gsm_dlci_command	-	data arrived on control channel
+ *	@dlci: channel
+ *	@data: block of bytes received
+ *	@len: length of received block
+ *
+ *	A UI or UIH frame has arrived which contains data for DLCI 0 the
+ *	control channel. This should contain a command EA followed by
+ *	control data bytes. The command EA contains a command/response bit
+ *	and we divide up the work accordingly.
+ */
+
+static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len)
+{
+	/* See what command is involved */
+	unsigned int command = 0;
+	unsigned int clen = 0;
+	unsigned int dlen;
+
+	/* read the command */
+	dlen = gsm_read_ea_val(&command, data, len);
+	len -= dlen;
+	data += dlen;
+
+	/* read any control data */
+	dlen = gsm_read_ea_val(&clen, data, len);
+	len -= dlen;
+	data += dlen;
+
+	/* Malformed command? */
+	if (clen > len) {
+		dlci->gsm->malformed++;
+		return;
+	}
+
+	if (command & 1)
+		gsm_control_message(dlci->gsm, command, data, clen);
+	else
+		gsm_control_response(dlci->gsm, command, data, clen);
+}
+
+/**
+ *	gsm_kick_timer	-	transmit if possible
+ *	@t: timer contained in our gsm object
+ *
+ *	Transmit data from DLCIs if the queue is empty. We can't rely on
+ *	a tty wakeup except when we filled the pipe so we need to fire off
+ *	new data ourselves in other cases.
+ */
+static void gsm_kick_timer(struct timer_list *t)
+{
+	struct gsm_mux *gsm = from_timer(gsm, t, kick_timer);
+	unsigned long flags;
+	int sent = 0;
+
+	spin_lock_irqsave(&gsm->tx_lock, flags);
+	/* If we have nothing running then we need to fire up */
+	if (gsm->tx_bytes < TX_THRESH_LO)
+		sent = gsm_dlci_data_sweep(gsm);
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
+
+	if (sent && debug & DBG_DATA)
+		pr_info("%s TX queue stalled\n", __func__);
+}
+
+/**
+ * gsm_dlci_copy_config_values	-	copy DLCI configuration
+ * @dlci: source DLCI
+ * @dc: configuration structure to fill
+ */
+static void gsm_dlci_copy_config_values(struct gsm_dlci *dlci, struct gsm_dlci_config *dc)
+{
+	memset(dc, 0, sizeof(*dc));
+	dc->channel = (u32)dlci->addr;
+	dc->adaption = (u32)dlci->adaption;
+	dc->mtu = (u32)dlci->mtu;
+	dc->priority = (u32)dlci->prio;
+	if (dlci->ftype == UIH)
+		dc->i = 1;
+	else
+		dc->i = 2;
+	dc->k = (u32)dlci->k;
+}
+
+/**
+ * gsm_dlci_config	-	configure DLCI from configuration
+ * @dlci: DLCI to configure
+ * @dc: DLCI configuration
+ * @open: open DLCI after configuration?
+ */
+static int gsm_dlci_config(struct gsm_dlci *dlci, struct gsm_dlci_config *dc, int open)
+{
+	struct gsm_mux *gsm;
+	bool need_restart = false;
+	bool need_open = false;
+	unsigned int i;
+
+	/*
+	 * Check that userspace doesn't put stuff in here to prevent breakages
+	 * in the future.
+	 */
+	for (i = 0; i < ARRAY_SIZE(dc->reserved); i++)
+		if (dc->reserved[i])
+			return -EINVAL;
+
+	if (!dlci)
+		return -EINVAL;
+	gsm = dlci->gsm;
+
+	/* Stuff we don't support yet - I frame transport */
+	if (dc->adaption != 1 && dc->adaption != 2)
+		return -EOPNOTSUPP;
+	if (dc->mtu > MAX_MTU || dc->mtu < MIN_MTU || dc->mtu > gsm->mru)
+		return -EINVAL;
+	if (dc->priority >= 64)
+		return -EINVAL;
+	if (dc->i == 0 || dc->i > 2)  /* UIH and UI only */
+		return -EINVAL;
+	if (dc->k > 7)
+		return -EINVAL;
+	if (dc->flags & ~GSM_FL_RESTART)   /* allow future extensions */
+		return -EINVAL;
+
+	/*
+	 * See what is needed for reconfiguration
+	 */
+	/* Framing fields */
+	if (dc->adaption != dlci->adaption)
+		need_restart = true;
+	if (dc->mtu != dlci->mtu)
+		need_restart = true;
+	if (dc->i != dlci->ftype)
+		need_restart = true;
+	/* Requires care */
+	if (dc->priority != dlci->prio)
+		need_restart = true;
+	if (dc->flags & GSM_FL_RESTART)
+		need_restart = true;
+
+	if ((open && gsm->wait_config) || need_restart)
+		need_open = true;
+	if (dlci->state == DLCI_WAITING_CONFIG) {
+		need_restart = false;
+		need_open = true;
+	}
+
+	/*
+	 * Close down what is needed, restart and initiate the new
+	 * configuration.
+	 */
+	if (need_restart) {
+		gsm_dlci_begin_close(dlci);
+		wait_event_interruptible(gsm->event, dlci->state == DLCI_CLOSED);
+		if (signal_pending(current))
+			return -EINTR;
+	}
+	/*
+	 * Setup the new configuration values
+	 */
+	dlci->adaption = (int)dc->adaption;
+
+	if (dc->mtu)
+		dlci->mtu = (unsigned int)dc->mtu;
+	else
+		dlci->mtu = gsm->mtu;
+
+	if (dc->priority)
+		dlci->prio = (u8)dc->priority;
+	else
+		dlci->prio = roundup(dlci->addr + 1, 8) - 1;
+
+	if (dc->i == 1)
+		dlci->ftype = UIH;
+	else if (dc->i == 2)
+		dlci->ftype = UI;
+
+	if (dc->k)
+		dlci->k = (u8)dc->k;
+	else
+		dlci->k = gsm->k;
+
+	if (need_open) {
+		if (gsm->initiator)
+			gsm_dlci_begin_open(dlci);
+		else
+			gsm_dlci_set_opening(dlci);
+	}
+
+	return 0;
+}
+
+/*
+ *	Allocate/Free DLCI channels
+ */
+
+/**
+ *	gsm_dlci_alloc		-	allocate a DLCI
+ *	@gsm: GSM mux
+ *	@addr: address of the DLCI
+ *
+ *	Allocate and install a new DLCI object into the GSM mux.
+ *
+ *	FIXME: review locking races
+ */
+
+static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr)
+{
+	struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC);
+	if (dlci == NULL)
+		return NULL;
+	spin_lock_init(&dlci->lock);
+	mutex_init(&dlci->mutex);
+	if (kfifo_alloc(&dlci->fifo, TX_SIZE, GFP_KERNEL) < 0) {
+		kfree(dlci);
+		return NULL;
+	}
+
+	skb_queue_head_init(&dlci->skb_list);
+	timer_setup(&dlci->t1, gsm_dlci_t1, 0);
+	tty_port_init(&dlci->port);
+	dlci->port.ops = &gsm_port_ops;
+	dlci->gsm = gsm;
+	dlci->addr = addr;
+	dlci->adaption = gsm->adaption;
+	dlci->mtu = gsm->mtu;
+	if (addr == 0)
+		dlci->prio = 0;
+	else
+		dlci->prio = roundup(addr + 1, 8) - 1;
+	dlci->ftype = gsm->ftype;
+	dlci->k = gsm->k;
+	dlci->state = DLCI_CLOSED;
+	if (addr) {
+		dlci->data = gsm_dlci_data;
+		/* Prevent us from sending data before the link is up */
+		dlci->constipated = true;
+	} else {
+		dlci->data = gsm_dlci_command;
+	}
+	gsm->dlci[addr] = dlci;
+	return dlci;
+}
+
+/**
+ *	gsm_dlci_free		-	free DLCI
+ *	@port: tty port for DLCI to free
+ *
+ *	Free up a DLCI.
+ *
+ *	Can sleep.
+ */
+static void gsm_dlci_free(struct tty_port *port)
+{
+	struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+
+	timer_shutdown_sync(&dlci->t1);
+	dlci->gsm->dlci[dlci->addr] = NULL;
+	kfifo_free(&dlci->fifo);
+	while ((dlci->skb = skb_dequeue(&dlci->skb_list)))
+		dev_kfree_skb(dlci->skb);
+	kfree(dlci);
+}
+
+static inline void dlci_get(struct gsm_dlci *dlci)
+{
+	tty_port_get(&dlci->port);
+}
+
+static inline void dlci_put(struct gsm_dlci *dlci)
+{
+	tty_port_put(&dlci->port);
+}
+
+static void gsm_destroy_network(struct gsm_dlci *dlci);
+
+/**
+ *	gsm_dlci_release		-	release DLCI
+ *	@dlci: DLCI to destroy
+ *
+ *	Release a DLCI. Actual free is deferred until either
+ *	mux is closed or tty is closed - whichever is last.
+ *
+ *	Can sleep.
+ */
+static void gsm_dlci_release(struct gsm_dlci *dlci)
+{
+	struct tty_struct *tty = tty_port_tty_get(&dlci->port);
+	if (tty) {
+		mutex_lock(&dlci->mutex);
+		gsm_destroy_network(dlci);
+		mutex_unlock(&dlci->mutex);
+
+		/* We cannot use tty_hangup() because in tty_kref_put() the tty
+		 * driver assumes that the hangup queue is free and reuses it to
+		 * queue release_one_tty() -> NULL pointer panic in
+		 * process_one_work().
+		 */
+		tty_vhangup(tty);
+
+		tty_port_tty_set(&dlci->port, NULL);
+		tty_kref_put(tty);
+	}
+	dlci->state = DLCI_CLOSED;
+	dlci_put(dlci);
+}
+
+/*
+ *	LAPBish link layer logic
+ */
+
+/**
+ *	gsm_queue		-	a GSM frame is ready to process
+ *	@gsm: pointer to our gsm mux
+ *
+ *	At this point in time a frame has arrived and been demangled from
+ *	the line encoding. All the differences between the encodings have
+ *	been handled below us and the frame is unpacked into the structures.
+ *	The fcs holds the header FCS but any data FCS must be added here.
+ */
+
+static void gsm_queue(struct gsm_mux *gsm)
+{
+	struct gsm_dlci *dlci;
+	u8 cr;
+	int address;
+
+	if (gsm->fcs != GOOD_FCS) {
+		gsm->bad_fcs++;
+		if (debug & DBG_DATA)
+			pr_debug("BAD FCS %02x\n", gsm->fcs);
+		return;
+	}
+	address = gsm->address >> 1;
+	if (address >= NUM_DLCI)
+		goto invalid;
+
+	cr = gsm->address & 1;		/* C/R bit */
+	cr ^= gsm->initiator ? 0 : 1;	/* Flip so 1 always means command */
+
+	gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len);
+
+	dlci = gsm->dlci[address];
+
+	switch (gsm->control) {
+	case SABM|PF:
+		if (cr == 1) {
+			gsm->open_error++;
+			goto invalid;
+		}
+		if (dlci == NULL)
+			dlci = gsm_dlci_alloc(gsm, address);
+		if (dlci == NULL) {
+			gsm->open_error++;
+			return;
+		}
+		if (dlci->dead)
+			gsm_response(gsm, address, DM|PF);
+		else {
+			gsm_response(gsm, address, UA|PF);
+			gsm_dlci_open(dlci);
+		}
+		break;
+	case DISC|PF:
+		if (cr == 1)
+			goto invalid;
+		if (dlci == NULL || dlci->state == DLCI_CLOSED) {
+			gsm_response(gsm, address, DM|PF);
+			return;
+		}
+		/* Real close complete */
+		gsm_response(gsm, address, UA|PF);
+		gsm_dlci_close(dlci);
+		break;
+	case UA|PF:
+		if (cr == 0 || dlci == NULL)
+			break;
+		switch (dlci->state) {
+		case DLCI_CLOSING:
+			gsm_dlci_close(dlci);
+			break;
+		case DLCI_OPENING:
+			gsm_dlci_open(dlci);
+			break;
+		default:
+			pr_debug("%s: unhandled state: %d\n", __func__,
+					dlci->state);
+			break;
+		}
+		break;
+	case DM:	/* DM can be valid unsolicited */
+	case DM|PF:
+		if (cr)
+			goto invalid;
+		if (dlci == NULL)
+			return;
+		gsm_dlci_close(dlci);
+		break;
+	case UI:
+	case UI|PF:
+	case UIH:
+	case UIH|PF:
+		if (dlci == NULL || dlci->state != DLCI_OPEN) {
+			gsm_response(gsm, address, DM|PF);
+			return;
+		}
+		dlci->data(dlci, gsm->buf, gsm->len);
+		break;
+	default:
+		goto invalid;
+	}
+	return;
+invalid:
+	gsm->malformed++;
+	return;
+}
+
+
+/**
+ *	gsm0_receive	-	perform processing for non-transparency
+ *	@gsm: gsm data for this ldisc instance
+ *	@c: character
+ *
+ *	Receive bytes in gsm mode 0
+ */
+
+static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
+{
+	unsigned int len;
+
+	switch (gsm->state) {
+	case GSM_SEARCH:	/* SOF marker */
+		if (c == GSM0_SOF) {
+			gsm->state = GSM_ADDRESS;
+			gsm->address = 0;
+			gsm->len = 0;
+			gsm->fcs = INIT_FCS;
+		}
+		break;
+	case GSM_ADDRESS:	/* Address EA */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		if (gsm_read_ea(&gsm->address, c))
+			gsm->state = GSM_CONTROL;
+		break;
+	case GSM_CONTROL:	/* Control Byte */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		gsm->control = c;
+		gsm->state = GSM_LEN0;
+		break;
+	case GSM_LEN0:		/* Length EA */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		if (gsm_read_ea(&gsm->len, c)) {
+			if (gsm->len > gsm->mru) {
+				gsm->bad_size++;
+				gsm->state = GSM_SEARCH;
+				break;
+			}
+			gsm->count = 0;
+			if (!gsm->len)
+				gsm->state = GSM_FCS;
+			else
+				gsm->state = GSM_DATA;
+			break;
+		}
+		gsm->state = GSM_LEN1;
+		break;
+	case GSM_LEN1:
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		len = c;
+		gsm->len |= len << 7;
+		if (gsm->len > gsm->mru) {
+			gsm->bad_size++;
+			gsm->state = GSM_SEARCH;
+			break;
+		}
+		gsm->count = 0;
+		if (!gsm->len)
+			gsm->state = GSM_FCS;
+		else
+			gsm->state = GSM_DATA;
+		break;
+	case GSM_DATA:		/* Data */
+		gsm->buf[gsm->count++] = c;
+		if (gsm->count == gsm->len) {
+			/* Calculate final FCS for UI frames over all data */
+			if ((gsm->control & ~PF) != UIH) {
+				gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf,
+							     gsm->count);
+			}
+			gsm->state = GSM_FCS;
+		}
+		break;
+	case GSM_FCS:		/* FCS follows the packet */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		gsm->state = GSM_SSOF;
+		break;
+	case GSM_SSOF:
+		gsm->state = GSM_SEARCH;
+		if (c == GSM0_SOF)
+			gsm_queue(gsm);
+		else
+			gsm->bad_size++;
+		break;
+	default:
+		pr_debug("%s: unhandled state: %d\n", __func__, gsm->state);
+		break;
+	}
+}
+
+/**
+ *	gsm1_receive	-	perform processing for non-transparency
+ *	@gsm: gsm data for this ldisc instance
+ *	@c: character
+ *
+ *	Receive bytes in mode 1 (Advanced option)
+ */
+
+static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
+{
+	/* handle XON/XOFF */
+	if ((c & ISO_IEC_646_MASK) == XON) {
+		gsm->constipated = true;
+		return;
+	} else if ((c & ISO_IEC_646_MASK) == XOFF) {
+		gsm->constipated = false;
+		/* Kick the link in case it is idling */
+		gsmld_write_trigger(gsm);
+		return;
+	}
+	if (c == GSM1_SOF) {
+		/* EOF is only valid in frame if we have got to the data state */
+		if (gsm->state == GSM_DATA) {
+			if (gsm->count < 1) {
+				/* Missing FSC */
+				gsm->malformed++;
+				gsm->state = GSM_START;
+				return;
+			}
+			/* Remove the FCS from data */
+			gsm->count--;
+			if ((gsm->control & ~PF) != UIH) {
+				/* Calculate final FCS for UI frames over all
+				 * data but FCS
+				 */
+				gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf,
+							     gsm->count);
+			}
+			/* Add the FCS itself to test against GOOD_FCS */
+			gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]);
+			gsm->len = gsm->count;
+			gsm_queue(gsm);
+			gsm->state  = GSM_START;
+			return;
+		}
+		/* Any partial frame was a runt so go back to start */
+		if (gsm->state != GSM_START) {
+			if (gsm->state != GSM_SEARCH)
+				gsm->malformed++;
+			gsm->state = GSM_START;
+		}
+		/* A SOF in GSM_START means we are still reading idling or
+		   framing bytes */
+		return;
+	}
+
+	if (c == GSM1_ESCAPE) {
+		gsm->escape = true;
+		return;
+	}
+
+	/* Only an unescaped SOF gets us out of GSM search */
+	if (gsm->state == GSM_SEARCH)
+		return;
+
+	if (gsm->escape) {
+		c ^= GSM1_ESCAPE_BITS;
+		gsm->escape = false;
+	}
+	switch (gsm->state) {
+	case GSM_START:		/* First byte after SOF */
+		gsm->address = 0;
+		gsm->state = GSM_ADDRESS;
+		gsm->fcs = INIT_FCS;
+		fallthrough;
+	case GSM_ADDRESS:	/* Address continuation */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		if (gsm_read_ea(&gsm->address, c))
+			gsm->state = GSM_CONTROL;
+		break;
+	case GSM_CONTROL:	/* Control Byte */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		gsm->control = c;
+		gsm->count = 0;
+		gsm->state = GSM_DATA;
+		break;
+	case GSM_DATA:		/* Data */
+		if (gsm->count > gsm->mru) {	/* Allow one for the FCS */
+			gsm->state = GSM_OVERRUN;
+			gsm->bad_size++;
+		} else
+			gsm->buf[gsm->count++] = c;
+		break;
+	case GSM_OVERRUN:	/* Over-long - eg a dropped SOF */
+		break;
+	default:
+		pr_debug("%s: unhandled state: %d\n", __func__, gsm->state);
+		break;
+	}
+}
+
+/**
+ *	gsm_error		-	handle tty error
+ *	@gsm: ldisc data
+ *
+ *	Handle an error in the receipt of data for a frame. Currently we just
+ *	go back to hunting for a SOF.
+ *
+ *	FIXME: better diagnostics ?
+ */
+
+static void gsm_error(struct gsm_mux *gsm)
+{
+	gsm->state = GSM_SEARCH;
+	gsm->io_error++;
+}
+
+/**
+ *	gsm_cleanup_mux		-	generic GSM protocol cleanup
+ *	@gsm: our mux
+ *	@disc: disconnect link?
+ *
+ *	Clean up the bits of the mux which are the same for all framing
+ *	protocols. Remove the mux from the mux table, stop all the timers
+ *	and then shut down each device hanging up the channels as we go.
+ */
+
+static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
+{
+	int i;
+	struct gsm_dlci *dlci;
+	struct gsm_msg *txq, *ntxq;
+
+	gsm->dead = true;
+	mutex_lock(&gsm->mutex);
+
+	dlci = gsm->dlci[0];
+	if (dlci) {
+		if (disc && dlci->state != DLCI_CLOSED) {
+			gsm_dlci_begin_close(dlci);
+			wait_event(gsm->event, dlci->state == DLCI_CLOSED);
+		}
+		dlci->dead = true;
+	}
+
+	/* Finish outstanding timers, making sure they are done */
+	del_timer_sync(&gsm->kick_timer);
+	del_timer_sync(&gsm->t2_timer);
+	del_timer_sync(&gsm->ka_timer);
+
+	/* Finish writing to ldisc */
+	flush_work(&gsm->tx_work);
+
+	/* Free up any link layer users and finally the control channel */
+	if (gsm->has_devices) {
+		gsm_unregister_devices(gsm_tty_driver, gsm->num);
+		gsm->has_devices = false;
+	}
+	for (i = NUM_DLCI - 1; i >= 0; i--)
+		if (gsm->dlci[i])
+			gsm_dlci_release(gsm->dlci[i]);
+	mutex_unlock(&gsm->mutex);
+	/* Now wipe the queues */
+	tty_ldisc_flush(gsm->tty);
+	list_for_each_entry_safe(txq, ntxq, &gsm->tx_ctrl_list, list)
+		kfree(txq);
+	INIT_LIST_HEAD(&gsm->tx_ctrl_list);
+	list_for_each_entry_safe(txq, ntxq, &gsm->tx_data_list, list)
+		kfree(txq);
+	INIT_LIST_HEAD(&gsm->tx_data_list);
+}
+
+/**
+ *	gsm_activate_mux	-	generic GSM setup
+ *	@gsm: our mux
+ *
+ *	Set up the bits of the mux which are the same for all framing
+ *	protocols. Add the mux to the mux table so it can be opened and
+ *	finally kick off connecting to DLCI 0 on the modem.
+ */
+
+static int gsm_activate_mux(struct gsm_mux *gsm)
+{
+	struct gsm_dlci *dlci;
+	int ret;
+
+	dlci = gsm_dlci_alloc(gsm, 0);
+	if (dlci == NULL)
+		return -ENOMEM;
+
+	if (gsm->encoding == GSM_BASIC_OPT)
+		gsm->receive = gsm0_receive;
+	else
+		gsm->receive = gsm1_receive;
+
+	ret = gsm_register_devices(gsm_tty_driver, gsm->num);
+	if (ret)
+		return ret;
+
+	gsm->has_devices = true;
+	gsm->dead = false;		/* Tty opens are now permissible */
+	return 0;
+}
+
+/**
+ *	gsm_free_mux		-	free up a mux
+ *	@gsm: mux to free
+ *
+ *	Dispose of allocated resources for a dead mux
+ */
+static void gsm_free_mux(struct gsm_mux *gsm)
+{
+	int i;
+
+	for (i = 0; i < MAX_MUX; i++) {
+		if (gsm == gsm_mux[i]) {
+			gsm_mux[i] = NULL;
+			break;
+		}
+	}
+	mutex_destroy(&gsm->mutex);
+	kfree(gsm->txframe);
+	kfree(gsm->buf);
+	kfree(gsm);
+}
+
+/**
+ *	gsm_free_muxr		-	free up a mux
+ *	@ref: kreference to the mux to free
+ *
+ *	Dispose of allocated resources for a dead mux
+ */
+static void gsm_free_muxr(struct kref *ref)
+{
+	struct gsm_mux *gsm = container_of(ref, struct gsm_mux, ref);
+	gsm_free_mux(gsm);
+}
+
+static inline void mux_get(struct gsm_mux *gsm)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&gsm_mux_lock, flags);
+	kref_get(&gsm->ref);
+	spin_unlock_irqrestore(&gsm_mux_lock, flags);
+}
+
+static inline void mux_put(struct gsm_mux *gsm)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&gsm_mux_lock, flags);
+	kref_put(&gsm->ref, gsm_free_muxr);
+	spin_unlock_irqrestore(&gsm_mux_lock, flags);
+}
+
+static inline unsigned int mux_num_to_base(struct gsm_mux *gsm)
+{
+	return gsm->num * NUM_DLCI;
+}
+
+static inline unsigned int mux_line_to_num(unsigned int line)
+{
+	return line / NUM_DLCI;
+}
+
+/**
+ *	gsm_alloc_mux		-	allocate a mux
+ *
+ *	Creates a new mux ready for activation.
+ */
+
+static struct gsm_mux *gsm_alloc_mux(void)
+{
+	int i;
+	struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL);
+	if (gsm == NULL)
+		return NULL;
+	gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL);
+	if (gsm->buf == NULL) {
+		kfree(gsm);
+		return NULL;
+	}
+	gsm->txframe = kmalloc(2 * (MAX_MTU + PROT_OVERHEAD - 1), GFP_KERNEL);
+	if (gsm->txframe == NULL) {
+		kfree(gsm->buf);
+		kfree(gsm);
+		return NULL;
+	}
+	spin_lock_init(&gsm->lock);
+	mutex_init(&gsm->mutex);
+	kref_init(&gsm->ref);
+	INIT_LIST_HEAD(&gsm->tx_ctrl_list);
+	INIT_LIST_HEAD(&gsm->tx_data_list);
+	timer_setup(&gsm->kick_timer, gsm_kick_timer, 0);
+	timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
+	timer_setup(&gsm->ka_timer, gsm_control_keep_alive, 0);
+	INIT_WORK(&gsm->tx_work, gsmld_write_task);
+	init_waitqueue_head(&gsm->event);
+	spin_lock_init(&gsm->control_lock);
+	spin_lock_init(&gsm->tx_lock);
+
+	gsm->t1 = T1;
+	gsm->t2 = T2;
+	gsm->t3 = T3;
+	gsm->n2 = N2;
+	gsm->k = K;
+	gsm->ftype = UIH;
+	gsm->adaption = 1;
+	gsm->encoding = GSM_ADV_OPT;
+	gsm->mru = 64;	/* Default to encoding 1 so these should be 64 */
+	gsm->mtu = 64;
+	gsm->dead = true;	/* Avoid early tty opens */
+	gsm->wait_config = false; /* Disabled */
+	gsm->keep_alive = 0;	/* Disabled */
+
+	/* Store the instance to the mux array or abort if no space is
+	 * available.
+	 */
+	spin_lock(&gsm_mux_lock);
+	for (i = 0; i < MAX_MUX; i++) {
+		if (!gsm_mux[i]) {
+			gsm_mux[i] = gsm;
+			gsm->num = i;
+			break;
+		}
+	}
+	spin_unlock(&gsm_mux_lock);
+	if (i == MAX_MUX) {
+		mutex_destroy(&gsm->mutex);
+		kfree(gsm->txframe);
+		kfree(gsm->buf);
+		kfree(gsm);
+		return NULL;
+	}
+
+	return gsm;
+}
+
+static void gsm_copy_config_values(struct gsm_mux *gsm,
+				   struct gsm_config *c)
+{
+	memset(c, 0, sizeof(*c));
+	c->adaption = gsm->adaption;
+	c->encapsulation = gsm->encoding;
+	c->initiator = gsm->initiator;
+	c->t1 = gsm->t1;
+	c->t2 = gsm->t2;
+	c->t3 = gsm->t3;
+	c->n2 = gsm->n2;
+	if (gsm->ftype == UIH)
+		c->i = 1;
+	else
+		c->i = 2;
+	pr_debug("Ftype %d i %d\n", gsm->ftype, c->i);
+	c->mru = gsm->mru;
+	c->mtu = gsm->mtu;
+	c->k = gsm->k;
+}
+
+static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c)
+{
+	int need_close = 0;
+	int need_restart = 0;
+
+	/* Stuff we don't support yet - UI or I frame transport */
+	if (c->adaption != 1 && c->adaption != 2)
+		return -EOPNOTSUPP;
+	/* Check the MRU/MTU range looks sane */
+	if (c->mru < MIN_MTU || c->mtu < MIN_MTU)
+		return -EINVAL;
+	if (c->mru > MAX_MRU || c->mtu > MAX_MTU)
+		return -EINVAL;
+	if (c->t3 > MAX_T3)
+		return -EINVAL;
+	if (c->n2 > 255)
+		return -EINVAL;
+	if (c->encapsulation > 1)	/* Basic, advanced, no I */
+		return -EINVAL;
+	if (c->initiator > 1)
+		return -EINVAL;
+	if (c->k > MAX_WINDOW_SIZE)
+		return -EINVAL;
+	if (c->i == 0 || c->i > 2)	/* UIH and UI only */
+		return -EINVAL;
+	/*
+	 * See what is needed for reconfiguration
+	 */
+
+	/* Timing fields */
+	if (c->t1 != 0 && c->t1 != gsm->t1)
+		need_restart = 1;
+	if (c->t2 != 0 && c->t2 != gsm->t2)
+		need_restart = 1;
+	if (c->encapsulation != gsm->encoding)
+		need_restart = 1;
+	if (c->adaption != gsm->adaption)
+		need_restart = 1;
+	/* Requires care */
+	if (c->initiator != gsm->initiator)
+		need_close = 1;
+	if (c->mru != gsm->mru)
+		need_restart = 1;
+	if (c->mtu != gsm->mtu)
+		need_restart = 1;
+
+	/*
+	 * Close down what is needed, restart and initiate the new
+	 * configuration. On the first time there is no DLCI[0]
+	 * and closing or cleaning up is not necessary.
+	 */
+	if (need_close || need_restart)
+		gsm_cleanup_mux(gsm, true);
+
+	gsm->initiator = c->initiator;
+	gsm->mru = c->mru;
+	gsm->mtu = c->mtu;
+	gsm->encoding = c->encapsulation ? GSM_ADV_OPT : GSM_BASIC_OPT;
+	gsm->adaption = c->adaption;
+	gsm->n2 = c->n2;
+
+	if (c->i == 1)
+		gsm->ftype = UIH;
+	else if (c->i == 2)
+		gsm->ftype = UI;
+
+	if (c->t1)
+		gsm->t1 = c->t1;
+	if (c->t2)
+		gsm->t2 = c->t2;
+	if (c->t3)
+		gsm->t3 = c->t3;
+	if (c->k)
+		gsm->k = c->k;
+
+	/*
+	 * FIXME: We need to separate activation/deactivation from adding
+	 * and removing from the mux array
+	 */
+	if (gsm->dead) {
+		int ret = gsm_activate_mux(gsm);
+		if (ret)
+			return ret;
+		if (gsm->initiator)
+			gsm_dlci_begin_open(gsm->dlci[0]);
+	}
+	return 0;
+}
+
+static void gsm_copy_config_ext_values(struct gsm_mux *gsm,
+				       struct gsm_config_ext *ce)
+{
+	memset(ce, 0, sizeof(*ce));
+	ce->wait_config = gsm->wait_config ? 1 : 0;
+	ce->keep_alive = gsm->keep_alive;
+}
+
+static int gsm_config_ext(struct gsm_mux *gsm, struct gsm_config_ext *ce)
+{
+	bool need_restart = false;
+	unsigned int i;
+
+	/*
+	 * Check that userspace doesn't put stuff in here to prevent breakages
+	 * in the future.
+	 */
+	for (i = 0; i < ARRAY_SIZE(ce->reserved); i++)
+		if (ce->reserved[i])
+			return -EINVAL;
+	if (ce->flags & ~GSM_FL_RESTART)
+		return -EINVAL;
+
+	/* Requires care */
+	if (ce->flags & GSM_FL_RESTART)
+		need_restart = true;
+
+	/*
+	 * Close down what is needed, restart and initiate the new
+	 * configuration. On the first time there is no DLCI[0]
+	 * and closing or cleaning up is not necessary.
+	 */
+	if (need_restart)
+		gsm_cleanup_mux(gsm, true);
+
+	/*
+	 * Setup the new configuration values
+	 */
+	gsm->wait_config = ce->wait_config ? true : false;
+	gsm->keep_alive = ce->keep_alive;
+
+	if (gsm->dead) {
+		int ret = gsm_activate_mux(gsm);
+		if (ret)
+			return ret;
+		if (gsm->initiator)
+			gsm_dlci_begin_open(gsm->dlci[0]);
+	}
+
+	return 0;
+}
+
+/**
+ *	gsmld_output		-	write to link
+ *	@gsm: our mux
+ *	@data: bytes to output
+ *	@len: size
+ *
+ *	Write a block of data from the GSM mux to the data channel. This
+ *	will eventually be serialized from above but at the moment isn't.
+ */
+
+static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
+{
+	if (tty_write_room(gsm->tty) < len) {
+		set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
+		return -ENOSPC;
+	}
+	if (debug & DBG_DATA)
+		gsm_hex_dump_bytes(__func__, data, len);
+	return gsm->tty->ops->write(gsm->tty, data, len);
+}
+
+
+/**
+ *	gsmld_write_trigger	-	schedule ldisc write task
+ *	@gsm: our mux
+ */
+static void gsmld_write_trigger(struct gsm_mux *gsm)
+{
+	if (!gsm || !gsm->dlci[0] || gsm->dlci[0]->dead)
+		return;
+	schedule_work(&gsm->tx_work);
+}
+
+
+/**
+ *	gsmld_write_task	-	ldisc write task
+ *	@work: our tx write work
+ *
+ *	Writes out data to the ldisc if possible. We are doing this here to
+ *	avoid dead-locking. This returns if no space or data is left for output.
+ */
+static void gsmld_write_task(struct work_struct *work)
+{
+	struct gsm_mux *gsm = container_of(work, struct gsm_mux, tx_work);
+	unsigned long flags;
+	int i, ret;
+
+	/* All outstanding control channel and control messages and one data
+	 * frame is sent.
+	 */
+	ret = -ENODEV;
+	spin_lock_irqsave(&gsm->tx_lock, flags);
+	if (gsm->tty)
+		ret = gsm_data_kick(gsm);
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
+
+	if (ret >= 0)
+		for (i = 0; i < NUM_DLCI; i++)
+			if (gsm->dlci[i])
+				tty_port_tty_wakeup(&gsm->dlci[i]->port);
+}
+
+/**
+ *	gsmld_attach_gsm	-	mode set up
+ *	@tty: our tty structure
+ *	@gsm: our mux
+ *
+ *	Set up the MUX for basic mode and commence connecting to the
+ *	modem. Currently called from the line discipline set up but
+ *	will need moving to an ioctl path.
+ */
+
+static void gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+{
+	gsm->tty = tty_kref_get(tty);
+	/* Turn off tty XON/XOFF handling to handle it explicitly. */
+	gsm->old_c_iflag = tty->termios.c_iflag;
+	tty->termios.c_iflag &= (IXON | IXOFF);
+}
+
+/**
+ *	gsmld_detach_gsm	-	stop doing 0710 mux
+ *	@tty: tty attached to the mux
+ *	@gsm: mux
+ *
+ *	Shutdown and then clean up the resources used by the line discipline
+ */
+
+static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+{
+	WARN_ON(tty != gsm->tty);
+	/* Restore tty XON/XOFF handling. */
+	gsm->tty->termios.c_iflag = gsm->old_c_iflag;
+	tty_kref_put(gsm->tty);
+	gsm->tty = NULL;
+}
+
+static void gsmld_receive_buf(struct tty_struct *tty, const u8 *cp,
+			      const u8 *fp, size_t count)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+	char flags = TTY_NORMAL;
+
+	if (debug & DBG_DATA)
+		gsm_hex_dump_bytes(__func__, cp, count);
+
+	for (; count; count--, cp++) {
+		if (fp)
+			flags = *fp++;
+		switch (flags) {
+		case TTY_NORMAL:
+			if (gsm->receive)
+				gsm->receive(gsm, *cp);
+			break;
+		case TTY_OVERRUN:
+		case TTY_BREAK:
+		case TTY_PARITY:
+		case TTY_FRAME:
+			gsm_error(gsm);
+			break;
+		default:
+			WARN_ONCE(1, "%s: unknown flag %d\n",
+			       tty_name(tty), flags);
+			break;
+		}
+	}
+	/* FASYNC if needed ? */
+	/* If clogged call tty_throttle(tty); */
+}
+
+/**
+ *	gsmld_flush_buffer	-	clean input queue
+ *	@tty:	terminal device
+ *
+ *	Flush the input buffer. Called when the line discipline is
+ *	being closed, when the tty layer wants the buffer flushed (eg
+ *	at hangup).
+ */
+
+static void gsmld_flush_buffer(struct tty_struct *tty)
+{
+}
+
+/**
+ *	gsmld_close		-	close the ldisc for this tty
+ *	@tty: device
+ *
+ *	Called from the terminal layer when this line discipline is
+ *	being shut down, either because of a close or becsuse of a
+ *	discipline change. The function will not be called while other
+ *	ldisc methods are in progress.
+ */
+
+static void gsmld_close(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+
+	/* The ldisc locks and closes the port before calling our close. This
+	 * means we have no way to do a proper disconnect. We will not bother
+	 * to do one.
+	 */
+	gsm_cleanup_mux(gsm, false);
+
+	gsmld_detach_gsm(tty, gsm);
+
+	gsmld_flush_buffer(tty);
+	/* Do other clean up here */
+	mux_put(gsm);
+}
+
+/**
+ *	gsmld_open		-	open an ldisc
+ *	@tty: terminal to open
+ *
+ *	Called when this line discipline is being attached to the
+ *	terminal device. Can sleep. Called serialized so that no
+ *	other events will occur in parallel. No further open will occur
+ *	until a close.
+ */
+
+static int gsmld_open(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (tty->ops->write == NULL)
+		return -EINVAL;
+
+	/* Attach our ldisc data */
+	gsm = gsm_alloc_mux();
+	if (gsm == NULL)
+		return -ENOMEM;
+
+	tty->disc_data = gsm;
+	tty->receive_room = 65536;
+
+	/* Attach the initial passive connection */
+	gsmld_attach_gsm(tty, gsm);
+
+	/* The mux will not be activated yet, we wait for correct
+	 * configuration first.
+	 */
+	if (gsm->encoding == GSM_BASIC_OPT)
+		gsm->receive = gsm0_receive;
+	else
+		gsm->receive = gsm1_receive;
+
+	return 0;
+}
+
+/**
+ *	gsmld_write_wakeup	-	asynchronous I/O notifier
+ *	@tty: tty device
+ *
+ *	Required for the ptys, serial driver etc. since processes
+ *	that attach themselves to the master and rely on ASYNC
+ *	IO must be woken up
+ */
+
+static void gsmld_write_wakeup(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+
+	/* Queue poll */
+	gsmld_write_trigger(gsm);
+}
+
+/**
+ *	gsmld_read		-	read function for tty
+ *	@tty: tty device
+ *	@file: file object
+ *	@buf: userspace buffer pointer
+ *	@nr: size of I/O
+ *	@cookie: unused
+ *	@offset: unused
+ *
+ *	Perform reads for the line discipline. We are guaranteed that the
+ *	line discipline will not be closed under us but we may get multiple
+ *	parallel readers and must handle this ourselves. We may also get
+ *	a hangup. Always called in user context, may sleep.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ */
+
+static ssize_t gsmld_read(struct tty_struct *tty, struct file *file, u8 *buf,
+			  size_t nr, void **cookie, unsigned long offset)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
+ *	gsmld_write		-	write function for tty
+ *	@tty: tty device
+ *	@file: file object
+ *	@buf: userspace buffer pointer
+ *	@nr: size of I/O
+ *
+ *	Called when the owner of the device wants to send a frame
+ *	itself (or some other control data). The data is transferred
+ *	as-is and must be properly framed and checksummed as appropriate
+ *	by userspace. Frames are either sent whole or not at all as this
+ *	avoids pain user side.
+ */
+
+static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
+			   const u8 *buf, size_t nr)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+	unsigned long flags;
+	int space;
+	int ret;
+
+	if (!gsm)
+		return -ENODEV;
+
+	ret = -ENOBUFS;
+	spin_lock_irqsave(&gsm->tx_lock, flags);
+	space = tty_write_room(tty);
+	if (space >= nr)
+		ret = tty->ops->write(tty, buf, nr);
+	else
+		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
+
+	return ret;
+}
+
+/**
+ *	gsmld_poll		-	poll method for N_GSM0710
+ *	@tty: terminal device
+ *	@file: file accessing it
+ *	@wait: poll table
+ *
+ *	Called when the line discipline is asked to poll() for data or
+ *	for special events. This code is not serialized with respect to
+ *	other events save open/close.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ *	Called without the kernel lock held - fine
+ */
+
+static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file,
+							poll_table *wait)
+{
+	__poll_t mask = 0;
+	struct gsm_mux *gsm = tty->disc_data;
+
+	poll_wait(file, &tty->read_wait, wait);
+	poll_wait(file, &tty->write_wait, wait);
+
+	if (gsm->dead)
+		mask |= EPOLLHUP;
+	if (tty_hung_up_p(file))
+		mask |= EPOLLHUP;
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		mask |= EPOLLHUP;
+	if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0)
+		mask |= EPOLLOUT | EPOLLWRNORM;
+	return mask;
+}
+
+static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd,
+		       unsigned long arg)
+{
+	struct gsm_config c;
+	struct gsm_config_ext ce;
+	struct gsm_dlci_config dc;
+	struct gsm_mux *gsm = tty->disc_data;
+	unsigned int base, addr;
+	struct gsm_dlci *dlci;
+
+	switch (cmd) {
+	case GSMIOC_GETCONF:
+		gsm_copy_config_values(gsm, &c);
+		if (copy_to_user((void __user *)arg, &c, sizeof(c)))
+			return -EFAULT;
+		return 0;
+	case GSMIOC_SETCONF:
+		if (copy_from_user(&c, (void __user *)arg, sizeof(c)))
+			return -EFAULT;
+		return gsm_config(gsm, &c);
+	case GSMIOC_GETFIRST:
+		base = mux_num_to_base(gsm);
+		return put_user(base + 1, (__u32 __user *)arg);
+	case GSMIOC_GETCONF_EXT:
+		gsm_copy_config_ext_values(gsm, &ce);
+		if (copy_to_user((void __user *)arg, &ce, sizeof(ce)))
+			return -EFAULT;
+		return 0;
+	case GSMIOC_SETCONF_EXT:
+		if (copy_from_user(&ce, (void __user *)arg, sizeof(ce)))
+			return -EFAULT;
+		return gsm_config_ext(gsm, &ce);
+	case GSMIOC_GETCONF_DLCI:
+		if (copy_from_user(&dc, (void __user *)arg, sizeof(dc)))
+			return -EFAULT;
+		if (dc.channel == 0 || dc.channel >= NUM_DLCI)
+			return -EINVAL;
+		addr = array_index_nospec(dc.channel, NUM_DLCI);
+		dlci = gsm->dlci[addr];
+		if (!dlci) {
+			dlci = gsm_dlci_alloc(gsm, addr);
+			if (!dlci)
+				return -ENOMEM;
+		}
+		gsm_dlci_copy_config_values(dlci, &dc);
+		if (copy_to_user((void __user *)arg, &dc, sizeof(dc)))
+			return -EFAULT;
+		return 0;
+	case GSMIOC_SETCONF_DLCI:
+		if (copy_from_user(&dc, (void __user *)arg, sizeof(dc)))
+			return -EFAULT;
+		if (dc.channel == 0 || dc.channel >= NUM_DLCI)
+			return -EINVAL;
+		addr = array_index_nospec(dc.channel, NUM_DLCI);
+		dlci = gsm->dlci[addr];
+		if (!dlci) {
+			dlci = gsm_dlci_alloc(gsm, addr);
+			if (!dlci)
+				return -ENOMEM;
+		}
+		return gsm_dlci_config(dlci, &dc, 0);
+	default:
+		return n_tty_ioctl_helper(tty, cmd, arg);
+	}
+}
+
+/*
+ *	Network interface
+ *
+ */
+
+static int gsm_mux_net_open(struct net_device *net)
+{
+	pr_debug("%s called\n", __func__);
+	netif_start_queue(net);
+	return 0;
+}
+
+static int gsm_mux_net_close(struct net_device *net)
+{
+	netif_stop_queue(net);
+	return 0;
+}
+
+static void dlci_net_free(struct gsm_dlci *dlci)
+{
+	if (!dlci->net) {
+		WARN_ON(1);
+		return;
+	}
+	dlci->adaption = dlci->prev_adaption;
+	dlci->data = dlci->prev_data;
+	free_netdev(dlci->net);
+	dlci->net = NULL;
+}
+static void net_free(struct kref *ref)
+{
+	struct gsm_mux_net *mux_net;
+	struct gsm_dlci *dlci;
+
+	mux_net = container_of(ref, struct gsm_mux_net, ref);
+	dlci = mux_net->dlci;
+
+	if (dlci->net) {
+		unregister_netdev(dlci->net);
+		dlci_net_free(dlci);
+	}
+}
+
+static inline void muxnet_get(struct gsm_mux_net *mux_net)
+{
+	kref_get(&mux_net->ref);
+}
+
+static inline void muxnet_put(struct gsm_mux_net *mux_net)
+{
+	kref_put(&mux_net->ref, net_free);
+}
+
+static netdev_tx_t gsm_mux_net_start_xmit(struct sk_buff *skb,
+				      struct net_device *net)
+{
+	struct gsm_mux_net *mux_net = netdev_priv(net);
+	struct gsm_dlci *dlci = mux_net->dlci;
+	muxnet_get(mux_net);
+
+	skb_queue_head(&dlci->skb_list, skb);
+	net->stats.tx_packets++;
+	net->stats.tx_bytes += skb->len;
+	gsm_dlci_data_kick(dlci);
+	/* And tell the kernel when the last transmit started. */
+	netif_trans_update(net);
+	muxnet_put(mux_net);
+	return NETDEV_TX_OK;
+}
+
+/* called when a packet did not ack after watchdogtimeout */
+static void gsm_mux_net_tx_timeout(struct net_device *net, unsigned int txqueue)
+{
+	/* Tell syslog we are hosed. */
+	dev_dbg(&net->dev, "Tx timed out.\n");
+
+	/* Update statistics */
+	net->stats.tx_errors++;
+}
+
+static void gsm_mux_rx_netchar(struct gsm_dlci *dlci,
+				const unsigned char *in_buf, int size)
+{
+	struct net_device *net = dlci->net;
+	struct sk_buff *skb;
+	struct gsm_mux_net *mux_net = netdev_priv(net);
+	muxnet_get(mux_net);
+
+	/* Allocate an sk_buff */
+	skb = dev_alloc_skb(size + NET_IP_ALIGN);
+	if (!skb) {
+		/* We got no receive buffer. */
+		net->stats.rx_dropped++;
+		muxnet_put(mux_net);
+		return;
+	}
+	skb_reserve(skb, NET_IP_ALIGN);
+	skb_put_data(skb, in_buf, size);
+
+	skb->dev = net;
+	skb->protocol = htons(ETH_P_IP);
+
+	/* Ship it off to the kernel */
+	netif_rx(skb);
+
+	/* update out statistics */
+	net->stats.rx_packets++;
+	net->stats.rx_bytes += size;
+	muxnet_put(mux_net);
+	return;
+}
+
+static void gsm_mux_net_init(struct net_device *net)
+{
+	static const struct net_device_ops gsm_netdev_ops = {
+		.ndo_open		= gsm_mux_net_open,
+		.ndo_stop		= gsm_mux_net_close,
+		.ndo_start_xmit		= gsm_mux_net_start_xmit,
+		.ndo_tx_timeout		= gsm_mux_net_tx_timeout,
+	};
+
+	net->netdev_ops = &gsm_netdev_ops;
+
+	/* fill in the other fields */
+	net->watchdog_timeo = GSM_NET_TX_TIMEOUT;
+	net->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+	net->type = ARPHRD_NONE;
+	net->tx_queue_len = 10;
+}
+
+
+/* caller holds the dlci mutex */
+static void gsm_destroy_network(struct gsm_dlci *dlci)
+{
+	struct gsm_mux_net *mux_net;
+
+	pr_debug("destroy network interface\n");
+	if (!dlci->net)
+		return;
+	mux_net = netdev_priv(dlci->net);
+	muxnet_put(mux_net);
+}
+
+
+/* caller holds the dlci mutex */
+static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc)
+{
+	char *netname;
+	int retval = 0;
+	struct net_device *net;
+	struct gsm_mux_net *mux_net;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	/* Already in a non tty mode */
+	if (dlci->adaption > 2)
+		return -EBUSY;
+
+	if (nc->protocol != htons(ETH_P_IP))
+		return -EPROTONOSUPPORT;
+
+	if (nc->adaption != 3 && nc->adaption != 4)
+		return -EPROTONOSUPPORT;
+
+	pr_debug("create network interface\n");
+
+	netname = "gsm%d";
+	if (nc->if_name[0] != '\0')
+		netname = nc->if_name;
+	net = alloc_netdev(sizeof(struct gsm_mux_net), netname,
+			   NET_NAME_UNKNOWN, gsm_mux_net_init);
+	if (!net) {
+		pr_err("alloc_netdev failed\n");
+		return -ENOMEM;
+	}
+	net->mtu = dlci->mtu;
+	net->min_mtu = MIN_MTU;
+	net->max_mtu = dlci->mtu;
+	mux_net = netdev_priv(net);
+	mux_net->dlci = dlci;
+	kref_init(&mux_net->ref);
+	strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */
+
+	/* reconfigure dlci for network */
+	dlci->prev_adaption = dlci->adaption;
+	dlci->prev_data = dlci->data;
+	dlci->adaption = nc->adaption;
+	dlci->data = gsm_mux_rx_netchar;
+	dlci->net = net;
+
+	pr_debug("register netdev\n");
+	retval = register_netdev(net);
+	if (retval) {
+		pr_err("network register fail %d\n", retval);
+		dlci_net_free(dlci);
+		return retval;
+	}
+	return net->ifindex;	/* return network index */
+}
+
+/* Line discipline for real tty */
+static struct tty_ldisc_ops tty_ldisc_packet = {
+	.owner		 = THIS_MODULE,
+	.num		 = N_GSM0710,
+	.name            = "n_gsm",
+	.open            = gsmld_open,
+	.close           = gsmld_close,
+	.flush_buffer    = gsmld_flush_buffer,
+	.read            = gsmld_read,
+	.write           = gsmld_write,
+	.ioctl           = gsmld_ioctl,
+	.poll            = gsmld_poll,
+	.receive_buf     = gsmld_receive_buf,
+	.write_wakeup    = gsmld_write_wakeup
+};
+
+/*
+ *	Virtual tty side
+ */
+
+/**
+ *	gsm_modem_upd_via_data	-	send modem bits via convergence layer
+ *	@dlci: channel
+ *	@brk: break signal
+ *
+ *	Send an empty frame to signal mobile state changes and to transmit the
+ *	break signal for adaption 2.
+ */
+
+static void gsm_modem_upd_via_data(struct gsm_dlci *dlci, u8 brk)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	unsigned long flags;
+
+	if (dlci->state != DLCI_OPEN || dlci->adaption != 2)
+		return;
+
+	spin_lock_irqsave(&gsm->tx_lock, flags);
+	gsm_dlci_modem_output(gsm, dlci, brk);
+	spin_unlock_irqrestore(&gsm->tx_lock, flags);
+}
+
+/**
+ *	gsm_modem_upd_via_msc	-	send modem bits via control frame
+ *	@dlci: channel
+ *	@brk: break signal
+ */
+
+static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk)
+{
+	u8 modembits[3];
+	struct gsm_control *ctrl;
+	int len = 2;
+
+	if (dlci->gsm->encoding != GSM_BASIC_OPT)
+		return 0;
+
+	modembits[0] = (dlci->addr << 2) | 2 | EA;  /* DLCI, Valid, EA */
+	if (!brk) {
+		modembits[1] = (gsm_encode_modem(dlci) << 1) | EA;
+	} else {
+		modembits[1] = gsm_encode_modem(dlci) << 1;
+		modembits[2] = (brk << 4) | 2 | EA; /* Length, Break, EA */
+		len++;
+	}
+	ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len);
+	if (ctrl == NULL)
+		return -ENOMEM;
+	return gsm_control_wait(dlci->gsm, ctrl);
+}
+
+/**
+ *	gsm_modem_update	-	send modem status line state
+ *	@dlci: channel
+ *	@brk: break signal
+ */
+
+static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk)
+{
+	if (dlci->gsm->dead)
+		return -EL2HLT;
+	if (dlci->adaption == 2) {
+		/* Send convergence layer type 2 empty data frame. */
+		gsm_modem_upd_via_data(dlci, brk);
+		return 0;
+	} else if (dlci->gsm->encoding == GSM_BASIC_OPT) {
+		/* Send as MSC control message. */
+		return gsm_modem_upd_via_msc(dlci, brk);
+	}
+
+	/* Modem status lines are not supported. */
+	return -EPROTONOSUPPORT;
+}
+
+/**
+ * gsm_wait_modem_change - wait for modem status line change
+ * @dlci: channel
+ * @mask: modem status line bits
+ *
+ * The function returns if:
+ * - any given modem status line bit changed
+ * - the wait event function got interrupted (e.g. by a signal)
+ * - the underlying DLCI was closed
+ * - the underlying ldisc device was removed
+ */
+static int gsm_wait_modem_change(struct gsm_dlci *dlci, u32 mask)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	u32 old = dlci->modem_rx;
+	int ret;
+
+	ret = wait_event_interruptible(gsm->event, gsm->dead ||
+				       dlci->state != DLCI_OPEN ||
+				       (old ^ dlci->modem_rx) & mask);
+	if (gsm->dead)
+		return -ENODEV;
+	if (dlci->state != DLCI_OPEN)
+		return -EL2NSYNC;
+	return ret;
+}
+
+static bool gsm_carrier_raised(struct tty_port *port)
+{
+	struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+	struct gsm_mux *gsm = dlci->gsm;
+
+	/* Not yet open so no carrier info */
+	if (dlci->state != DLCI_OPEN)
+		return false;
+	if (debug & DBG_CD_ON)
+		return true;
+
+	/*
+	 * Basic mode with control channel in ADM mode may not respond
+	 * to CMD_MSC at all and modem_rx is empty.
+	 */
+	if (gsm->encoding == GSM_BASIC_OPT &&
+	    gsm->dlci[0]->mode == DLCI_MODE_ADM && !dlci->modem_rx)
+		return true;
+
+	return dlci->modem_rx & TIOCM_CD;
+}
+
+static void gsm_dtr_rts(struct tty_port *port, bool active)
+{
+	struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+	unsigned int modem_tx = dlci->modem_tx;
+	if (active)
+		modem_tx |= TIOCM_DTR | TIOCM_RTS;
+	else
+		modem_tx &= ~(TIOCM_DTR | TIOCM_RTS);
+	if (modem_tx != dlci->modem_tx) {
+		dlci->modem_tx = modem_tx;
+		gsm_modem_update(dlci, 0);
+	}
+}
+
+static const struct tty_port_operations gsm_port_ops = {
+	.carrier_raised = gsm_carrier_raised,
+	.dtr_rts = gsm_dtr_rts,
+	.destruct = gsm_dlci_free,
+};
+
+static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct gsm_mux *gsm;
+	struct gsm_dlci *dlci;
+	unsigned int line = tty->index;
+	unsigned int mux = mux_line_to_num(line);
+	bool alloc = false;
+	int ret;
+
+	line = line & 0x3F;
+
+	if (mux >= MAX_MUX)
+		return -ENXIO;
+	/* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */
+	if (gsm_mux[mux] == NULL)
+		return -EUNATCH;
+	if (line == 0 || line > 61)	/* 62/63 reserved */
+		return -ECHRNG;
+	gsm = gsm_mux[mux];
+	if (gsm->dead)
+		return -EL2HLT;
+	/* If DLCI 0 is not yet fully open return an error.
+	This is ok from a locking
+	perspective as we don't have to worry about this
+	if DLCI0 is lost */
+	mutex_lock(&gsm->mutex);
+	if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) {
+		mutex_unlock(&gsm->mutex);
+		return -EL2NSYNC;
+	}
+	dlci = gsm->dlci[line];
+	if (dlci == NULL) {
+		alloc = true;
+		dlci = gsm_dlci_alloc(gsm, line);
+	}
+	if (dlci == NULL) {
+		mutex_unlock(&gsm->mutex);
+		return -ENOMEM;
+	}
+	ret = tty_port_install(&dlci->port, driver, tty);
+	if (ret) {
+		if (alloc)
+			dlci_put(dlci);
+		mutex_unlock(&gsm->mutex);
+		return ret;
+	}
+
+	dlci_get(dlci);
+	dlci_get(gsm->dlci[0]);
+	mux_get(gsm);
+	tty->driver_data = dlci;
+	mutex_unlock(&gsm->mutex);
+
+	return 0;
+}
+
+static int gsmtty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	struct tty_port *port = &dlci->port;
+
+	port->count++;
+	tty_port_tty_set(port, tty);
+
+	dlci->modem_rx = 0;
+	/* We could in theory open and close before we wait - eg if we get
+	   a DM straight back. This is ok as that will have caused a hangup */
+	tty_port_set_initialized(port, true);
+	/* Start sending off SABM messages */
+	if (!dlci->gsm->wait_config) {
+		/* Start sending off SABM messages */
+		if (dlci->gsm->initiator)
+			gsm_dlci_begin_open(dlci);
+		else
+			gsm_dlci_set_opening(dlci);
+	} else {
+		gsm_dlci_set_wait_config(dlci);
+	}
+	/* And wait for virtual carrier */
+	return tty_port_block_til_ready(port, tty, filp);
+}
+
+static void gsmtty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+
+	if (dlci == NULL)
+		return;
+	if (dlci->state == DLCI_CLOSED)
+		return;
+	mutex_lock(&dlci->mutex);
+	gsm_destroy_network(dlci);
+	mutex_unlock(&dlci->mutex);
+	if (tty_port_close_start(&dlci->port, tty, filp) == 0)
+		return;
+	gsm_dlci_begin_close(dlci);
+	if (tty_port_initialized(&dlci->port) && C_HUPCL(tty))
+		tty_port_lower_dtr_rts(&dlci->port);
+	tty_port_close_end(&dlci->port, tty);
+	tty_port_tty_set(&dlci->port, NULL);
+	return;
+}
+
+static void gsmtty_hangup(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return;
+	tty_port_hangup(&dlci->port);
+	gsm_dlci_begin_close(dlci);
+}
+
+static ssize_t gsmtty_write(struct tty_struct *tty, const u8 *buf, size_t len)
+{
+	int sent;
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return -EINVAL;
+	/* Stuff the bytes into the fifo queue */
+	sent = kfifo_in_locked(&dlci->fifo, buf, len, &dlci->lock);
+	/* Need to kick the channel */
+	gsm_dlci_data_kick(dlci);
+	return sent;
+}
+
+static unsigned int gsmtty_write_room(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return 0;
+	return kfifo_avail(&dlci->fifo);
+}
+
+static unsigned int gsmtty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return 0;
+	return kfifo_len(&dlci->fifo);
+}
+
+static void gsmtty_flush_buffer(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	unsigned long flags;
+
+	if (dlci->state == DLCI_CLOSED)
+		return;
+	/* Caution needed: If we implement reliable transport classes
+	   then the data being transmitted can't simply be junked once
+	   it has first hit the stack. Until then we can just blow it
+	   away */
+	spin_lock_irqsave(&dlci->lock, flags);
+	kfifo_reset(&dlci->fifo);
+	spin_unlock_irqrestore(&dlci->lock, flags);
+	/* Need to unhook this DLCI from the transmit queue logic */
+}
+
+static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	/* The FIFO handles the queue so the kernel will do the right
+	   thing waiting on chars_in_buffer before calling us. No work
+	   to do here */
+}
+
+static int gsmtty_tiocmget(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return -EINVAL;
+	return dlci->modem_rx;
+}
+
+static int gsmtty_tiocmset(struct tty_struct *tty,
+	unsigned int set, unsigned int clear)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	unsigned int modem_tx = dlci->modem_tx;
+
+	if (dlci->state == DLCI_CLOSED)
+		return -EINVAL;
+	modem_tx &= ~clear;
+	modem_tx |= set;
+
+	if (modem_tx != dlci->modem_tx) {
+		dlci->modem_tx = modem_tx;
+		return gsm_modem_update(dlci, 0);
+	}
+	return 0;
+}
+
+
+static int gsmtty_ioctl(struct tty_struct *tty,
+			unsigned int cmd, unsigned long arg)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	struct gsm_netconfig nc;
+	struct gsm_dlci_config dc;
+	int index;
+
+	if (dlci->state == DLCI_CLOSED)
+		return -EINVAL;
+	switch (cmd) {
+	case GSMIOC_ENABLE_NET:
+		if (copy_from_user(&nc, (void __user *)arg, sizeof(nc)))
+			return -EFAULT;
+		nc.if_name[IFNAMSIZ-1] = '\0';
+		/* return net interface index or error code */
+		mutex_lock(&dlci->mutex);
+		index = gsm_create_network(dlci, &nc);
+		mutex_unlock(&dlci->mutex);
+		if (copy_to_user((void __user *)arg, &nc, sizeof(nc)))
+			return -EFAULT;
+		return index;
+	case GSMIOC_DISABLE_NET:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		mutex_lock(&dlci->mutex);
+		gsm_destroy_network(dlci);
+		mutex_unlock(&dlci->mutex);
+		return 0;
+	case GSMIOC_GETCONF_DLCI:
+		if (copy_from_user(&dc, (void __user *)arg, sizeof(dc)))
+			return -EFAULT;
+		if (dc.channel != dlci->addr)
+			return -EPERM;
+		gsm_dlci_copy_config_values(dlci, &dc);
+		if (copy_to_user((void __user *)arg, &dc, sizeof(dc)))
+			return -EFAULT;
+		return 0;
+	case GSMIOC_SETCONF_DLCI:
+		if (copy_from_user(&dc, (void __user *)arg, sizeof(dc)))
+			return -EFAULT;
+		if (dc.channel >= NUM_DLCI)
+			return -EINVAL;
+		if (dc.channel != 0 && dc.channel != dlci->addr)
+			return -EPERM;
+		return gsm_dlci_config(dlci, &dc, 1);
+	case TIOCMIWAIT:
+		return gsm_wait_modem_change(dlci, (u32)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static void gsmtty_set_termios(struct tty_struct *tty,
+			       const struct ktermios *old)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return;
+	/* For the moment its fixed. In actual fact the speed information
+	   for the virtual channel can be propogated in both directions by
+	   the RPN control message. This however rapidly gets nasty as we
+	   then have to remap modem signals each way according to whether
+	   our virtual cable is null modem etc .. */
+	tty_termios_copy_hw(&tty->termios, old);
+}
+
+static void gsmtty_throttle(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return;
+	if (C_CRTSCTS(tty))
+		dlci->modem_tx &= ~TIOCM_RTS;
+	dlci->throttled = true;
+	/* Send an MSC with RTS cleared */
+	gsm_modem_update(dlci, 0);
+}
+
+static void gsmtty_unthrottle(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci->state == DLCI_CLOSED)
+		return;
+	if (C_CRTSCTS(tty))
+		dlci->modem_tx |= TIOCM_RTS;
+	dlci->throttled = false;
+	/* Send an MSC with RTS set */
+	gsm_modem_update(dlci, 0);
+}
+
+static int gsmtty_break_ctl(struct tty_struct *tty, int state)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	int encode = 0;	/* Off */
+	if (dlci->state == DLCI_CLOSED)
+		return -EINVAL;
+
+	if (state == -1)	/* "On indefinitely" - we can't encode this
+				    properly */
+		encode = 0x0F;
+	else if (state > 0) {
+		encode = state / 200;	/* mS to encoding */
+		if (encode > 0x0F)
+			encode = 0x0F;	/* Best effort */
+	}
+	return gsm_modem_update(dlci, encode);
+}
+
+static void gsmtty_cleanup(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	struct gsm_mux *gsm = dlci->gsm;
+
+	dlci_put(dlci);
+	dlci_put(gsm->dlci[0]);
+	mux_put(gsm);
+}
+
+/* Virtual ttys for the demux */
+static const struct tty_operations gsmtty_ops = {
+	.install		= gsmtty_install,
+	.open			= gsmtty_open,
+	.close			= gsmtty_close,
+	.write			= gsmtty_write,
+	.write_room		= gsmtty_write_room,
+	.chars_in_buffer	= gsmtty_chars_in_buffer,
+	.flush_buffer		= gsmtty_flush_buffer,
+	.ioctl			= gsmtty_ioctl,
+	.throttle		= gsmtty_throttle,
+	.unthrottle		= gsmtty_unthrottle,
+	.set_termios		= gsmtty_set_termios,
+	.hangup			= gsmtty_hangup,
+	.wait_until_sent	= gsmtty_wait_until_sent,
+	.tiocmget		= gsmtty_tiocmget,
+	.tiocmset		= gsmtty_tiocmset,
+	.break_ctl		= gsmtty_break_ctl,
+	.cleanup		= gsmtty_cleanup,
+};
+
+
+
+static int __init gsm_init(void)
+{
+	/* Fill in our line protocol discipline, and register it */
+	int status = tty_register_ldisc(&tty_ldisc_packet);
+	if (status != 0) {
+		pr_err("n_gsm: can't register line discipline (err = %d)\n",
+								status);
+		return status;
+	}
+
+	gsm_tty_driver = tty_alloc_driver(GSM_TTY_MINORS, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK);
+	if (IS_ERR(gsm_tty_driver)) {
+		pr_err("gsm_init: tty allocation failed.\n");
+		status = PTR_ERR(gsm_tty_driver);
+		goto err_unreg_ldisc;
+	}
+	gsm_tty_driver->driver_name	= "gsmtty";
+	gsm_tty_driver->name		= "gsmtty";
+	gsm_tty_driver->major		= 0;	/* Dynamic */
+	gsm_tty_driver->minor_start	= 0;
+	gsm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
+	gsm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
+	gsm_tty_driver->init_termios	= tty_std_termios;
+	/* Fixme */
+	gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
+	tty_set_operations(gsm_tty_driver, &gsmtty_ops);
+
+	if (tty_register_driver(gsm_tty_driver)) {
+		pr_err("gsm_init: tty registration failed.\n");
+		status = -EBUSY;
+		goto err_put_driver;
+	}
+	pr_debug("gsm_init: loaded as %d,%d.\n",
+			gsm_tty_driver->major, gsm_tty_driver->minor_start);
+	return 0;
+err_put_driver:
+	tty_driver_kref_put(gsm_tty_driver);
+err_unreg_ldisc:
+	tty_unregister_ldisc(&tty_ldisc_packet);
+	return status;
+}
+
+static void __exit gsm_exit(void)
+{
+	tty_unregister_ldisc(&tty_ldisc_packet);
+	tty_unregister_driver(gsm_tty_driver);
+	tty_driver_kref_put(gsm_tty_driver);
+}
+
+module_init(gsm_init);
+module_exit(gsm_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_GSM0710);
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
new file mode 100644
index 000000000..a670419ef
--- /dev/null
+++ b/drivers/tty/n_hdlc.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-1.0+
+/* generic HDLC line discipline for Linux
+ *
+ * Written by Paul Fulghum paulkf@microgate.com
+ * for Microgate Corporation
+ *
+ * Microgate and SyncLink are registered trademarks of Microgate Corporation
+ *
+ * Adapted from ppp.c, written by Michael Callahan <callahan@maths.ox.ac.uk>,
+ *	Al Longyear <longyear@netcom.com>,
+ *	Paul Mackerras <Paul.Mackerras@cs.anu.edu.au>
+ *
+ * Original release 01/11/99
+ *
+ * This module implements the tty line discipline N_HDLC for use with
+ * tty device drivers that support bit-synchronous HDLC communications.
+ *
+ * All HDLC data is frame oriented which means:
+ *
+ * 1. tty write calls represent one complete transmit frame of data
+ *    The device driver should accept the complete frame or none of
+ *    the frame (busy) in the write method. Each write call should have
+ *    a byte count in the range of 2-65535 bytes (2 is min HDLC frame
+ *    with 1 addr byte and 1 ctrl byte). The max byte count of 65535
+ *    should include any crc bytes required. For example, when using
+ *    CCITT CRC32, 4 crc bytes are required, so the maximum size frame
+ *    the application may transmit is limited to 65531 bytes. For CCITT
+ *    CRC16, the maximum application frame size would be 65533.
+ *
+ *
+ * 2. receive callbacks from the device driver represents
+ *    one received frame. The device driver should bypass
+ *    the tty flip buffer and call the line discipline receive
+ *    callback directly to avoid fragmenting or concatenating
+ *    multiple frames into a single receive callback.
+ *
+ *    The HDLC line discipline queues the receive frames in separate
+ *    buffers so complete receive frames can be returned by the
+ *    tty read calls.
+ *
+ * 3. tty read calls returns an entire frame of data or nothing.
+ *
+ * 4. all send and receive data is considered raw. No processing
+ *    or translation is performed by the line discipline, regardless
+ *    of the tty flags
+ *
+ * 5. When line discipline is queried for the amount of receive
+ *    data available (FIOC), 0 is returned if no data available,
+ *    otherwise the count of the next available frame is returned.
+ *    (instead of the sum of all received frame counts).
+ *
+ * These conventions allow the standard tty programming interface
+ * to be used for synchronous HDLC applications when used with
+ * this line discipline (or another line discipline that is frame
+ * oriented such as N_PPP).
+ *
+ * The SyncLink driver (synclink.c) implements both asynchronous
+ * (using standard line discipline N_TTY) and synchronous HDLC
+ * (using N_HDLC) communications, with the latter using the above
+ * conventions.
+ *
+ * This implementation is very basic and does not maintain
+ * any statistics. The main point is to enforce the raw data
+ * and frame orientation of HDLC communications.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+
+#include <linux/poll.h>
+#include <linux/in.h>
+#include <linux/ioctl.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/string.h>	/* used in new tty drivers */
+#include <linux/signal.h>	/* used in new tty drivers */
+#include <linux/if.h>
+#include <linux/bitops.h>
+
+#include <linux/uaccess.h>
+#include "tty.h"
+
+/*
+ * Buffers for individual HDLC frames
+ */
+#define MAX_HDLC_FRAME_SIZE 65535
+#define DEFAULT_RX_BUF_COUNT 10
+#define MAX_RX_BUF_COUNT 60
+#define DEFAULT_TX_BUF_COUNT 3
+
+struct n_hdlc_buf {
+	struct list_head  list_item;
+	int		  count;
+	char		  buf[];
+};
+
+struct n_hdlc_buf_list {
+	struct list_head  list;
+	int		  count;
+	spinlock_t	  spinlock;
+};
+
+/**
+ * struct n_hdlc - per device instance data structure
+ * @tbusy: reentrancy flag for tx wakeup code
+ * @woke_up: tx wakeup needs to be run again as it was called while @tbusy
+ * @tx_buf_list: list of pending transmit frame buffers
+ * @rx_buf_list: list of received frame buffers
+ * @tx_free_buf_list: list unused transmit frame buffers
+ * @rx_free_buf_list: list unused received frame buffers
+ */
+struct n_hdlc {
+	bool			tbusy;
+	bool			woke_up;
+	struct n_hdlc_buf_list	tx_buf_list;
+	struct n_hdlc_buf_list	rx_buf_list;
+	struct n_hdlc_buf_list	tx_free_buf_list;
+	struct n_hdlc_buf_list	rx_free_buf_list;
+	struct work_struct	write_work;
+	struct tty_struct	*tty_for_write_work;
+};
+
+/*
+ * HDLC buffer list manipulation functions
+ */
+static void n_hdlc_buf_return(struct n_hdlc_buf_list *buf_list,
+						struct n_hdlc_buf *buf);
+static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
+			   struct n_hdlc_buf *buf);
+static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
+
+/* Local functions */
+
+static struct n_hdlc *n_hdlc_alloc(void);
+static void n_hdlc_tty_write_work(struct work_struct *work);
+
+/* max frame size for memory allocations */
+static int maxframe = 4096;
+
+static void flush_rx_queue(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+	struct n_hdlc_buf *buf;
+
+	while ((buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list)))
+		n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, buf);
+}
+
+static void flush_tx_queue(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+	struct n_hdlc_buf *buf;
+
+	while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list)))
+		n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf);
+}
+
+static void n_hdlc_free_buf_list(struct n_hdlc_buf_list *list)
+{
+	struct n_hdlc_buf *buf;
+
+	do {
+		buf = n_hdlc_buf_get(list);
+		kfree(buf);
+	} while (buf);
+}
+
+/**
+ * n_hdlc_tty_close - line discipline close
+ * @tty: pointer to tty info structure
+ *
+ * Called when the line discipline is changed to something
+ * else, the tty is closed, or the tty detects a hangup.
+ */
+static void n_hdlc_tty_close(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+
+#if defined(TTY_NO_WRITE_SPLIT)
+	clear_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+#endif
+	tty->disc_data = NULL;
+
+	/* Ensure that the n_hdlcd process is not hanging on select()/poll() */
+	wake_up_interruptible(&tty->read_wait);
+	wake_up_interruptible(&tty->write_wait);
+
+	cancel_work_sync(&n_hdlc->write_work);
+
+	n_hdlc_free_buf_list(&n_hdlc->rx_free_buf_list);
+	n_hdlc_free_buf_list(&n_hdlc->tx_free_buf_list);
+	n_hdlc_free_buf_list(&n_hdlc->rx_buf_list);
+	n_hdlc_free_buf_list(&n_hdlc->tx_buf_list);
+	kfree(n_hdlc);
+}	/* end of n_hdlc_tty_close() */
+
+/**
+ * n_hdlc_tty_open - called when line discipline changed to n_hdlc
+ * @tty: pointer to tty info structure
+ *
+ * Returns 0 if success, otherwise error code
+ */
+static int n_hdlc_tty_open(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+
+	pr_debug("%s() called (device=%s)\n", __func__, tty->name);
+
+	/* There should not be an existing table for this slot. */
+	if (n_hdlc) {
+		pr_err("%s: tty already associated!\n", __func__);
+		return -EEXIST;
+	}
+
+	n_hdlc = n_hdlc_alloc();
+	if (!n_hdlc) {
+		pr_err("%s: n_hdlc_alloc failed\n", __func__);
+		return -ENFILE;
+	}
+
+	INIT_WORK(&n_hdlc->write_work, n_hdlc_tty_write_work);
+	n_hdlc->tty_for_write_work = tty;
+	tty->disc_data = n_hdlc;
+	tty->receive_room = 65536;
+
+	/* change tty_io write() to not split large writes into 8K chunks */
+	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+
+	/* flush receive data from driver */
+	tty_driver_flush_buffer(tty);
+
+	return 0;
+
+}	/* end of n_tty_hdlc_open() */
+
+/**
+ * n_hdlc_send_frames - send frames on pending send buffer list
+ * @n_hdlc: pointer to ldisc instance data
+ * @tty: pointer to tty instance data
+ *
+ * Send frames on pending send buffer list until the driver does not accept a
+ * frame (busy) this function is called after adding a frame to the send buffer
+ * list and by the tty wakeup callback.
+ */
+static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
+{
+	register int actual;
+	unsigned long flags;
+	struct n_hdlc_buf *tbuf;
+
+check_again:
+
+	spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+	if (n_hdlc->tbusy) {
+		n_hdlc->woke_up = true;
+		spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+		return;
+	}
+	n_hdlc->tbusy = true;
+	n_hdlc->woke_up = false;
+	spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+
+	tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+	while (tbuf) {
+		pr_debug("sending frame %p, count=%d\n", tbuf, tbuf->count);
+
+		/* Send the next block of data to device */
+		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+		actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
+
+		/* rollback was possible and has been done */
+		if (actual == -ERESTARTSYS) {
+			n_hdlc_buf_return(&n_hdlc->tx_buf_list, tbuf);
+			break;
+		}
+		/* if transmit error, throw frame away by */
+		/* pretending it was accepted by driver */
+		if (actual < 0)
+			actual = tbuf->count;
+
+		if (actual == tbuf->count) {
+			pr_debug("frame %p completed\n", tbuf);
+
+			/* free current transmit buffer */
+			n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, tbuf);
+
+			/* wait up sleeping writers */
+			wake_up_interruptible(&tty->write_wait);
+
+			/* get next pending transmit buffer */
+			tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+		} else {
+			pr_debug("frame %p pending\n", tbuf);
+
+			/*
+			 * the buffer was not accepted by driver,
+			 * return it back into tx queue
+			 */
+			n_hdlc_buf_return(&n_hdlc->tx_buf_list, tbuf);
+			break;
+		}
+	}
+
+	if (!tbuf)
+		clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+
+	/* Clear the re-entry flag */
+	spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+	n_hdlc->tbusy = false;
+	spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+
+	if (n_hdlc->woke_up)
+		goto check_again;
+}	/* end of n_hdlc_send_frames() */
+
+/**
+ * n_hdlc_tty_write_work - Asynchronous callback for transmit wakeup
+ * @work: pointer to work_struct
+ *
+ * Called when low level device driver can accept more send data.
+ */
+static void n_hdlc_tty_write_work(struct work_struct *work)
+{
+	struct n_hdlc *n_hdlc = container_of(work, struct n_hdlc, write_work);
+	struct tty_struct *tty = n_hdlc->tty_for_write_work;
+
+	n_hdlc_send_frames(n_hdlc, tty);
+}	/* end of n_hdlc_tty_write_work() */
+
+/**
+ * n_hdlc_tty_wakeup - Callback for transmit wakeup
+ * @tty: pointer to associated tty instance data
+ *
+ * Called when low level device driver can accept more send data.
+ */
+static void n_hdlc_tty_wakeup(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+
+	schedule_work(&n_hdlc->write_work);
+}	/* end of n_hdlc_tty_wakeup() */
+
+/**
+ * n_hdlc_tty_receive - Called by tty driver when receive data is available
+ * @tty: pointer to tty instance data
+ * @data: pointer to received data
+ * @flags: pointer to flags for data
+ * @count: count of received data in bytes
+ *
+ * Called by tty low level driver when receive data is available. Data is
+ * interpreted as one HDLC frame.
+ */
+static void n_hdlc_tty_receive(struct tty_struct *tty, const u8 *data,
+			       const u8 *flags, size_t count)
+{
+	register struct n_hdlc *n_hdlc = tty->disc_data;
+	register struct n_hdlc_buf *buf;
+
+	pr_debug("%s() called count=%zu\n", __func__, count);
+
+	if (count > maxframe) {
+		pr_debug("rx count>maxframesize, data discarded\n");
+		return;
+	}
+
+	/* get a free HDLC buffer */
+	buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
+	if (!buf) {
+		/*
+		 * no buffers in free list, attempt to allocate another rx
+		 * buffer unless the maximum count has been reached
+		 */
+		if (n_hdlc->rx_buf_list.count < MAX_RX_BUF_COUNT)
+			buf = kmalloc(struct_size(buf, buf, maxframe),
+				      GFP_ATOMIC);
+	}
+
+	if (!buf) {
+		pr_debug("no more rx buffers, data discarded\n");
+		return;
+	}
+
+	/* copy received data to HDLC buffer */
+	memcpy(buf->buf, data, count);
+	buf->count = count;
+
+	/* add HDLC buffer to list of received frames */
+	n_hdlc_buf_put(&n_hdlc->rx_buf_list, buf);
+
+	/* wake up any blocked reads and perform async signalling */
+	wake_up_interruptible(&tty->read_wait);
+	if (tty->fasync != NULL)
+		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+
+}	/* end of n_hdlc_tty_receive() */
+
+/**
+ * n_hdlc_tty_read - Called to retrieve one frame of data (if available)
+ * @tty: pointer to tty instance data
+ * @file: pointer to open file object
+ * @kbuf: pointer to returned data buffer
+ * @nr: size of returned data buffer
+ * @cookie: stored rbuf from previous run
+ * @offset: offset into the data buffer
+ *
+ * Returns the number of bytes returned or error code.
+ */
+static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
+			       u8 *kbuf, size_t nr, void **cookie,
+			       unsigned long offset)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+	int ret = 0;
+	struct n_hdlc_buf *rbuf;
+	DECLARE_WAITQUEUE(wait, current);
+
+	/* Is this a repeated call for an rbuf we already found earlier? */
+	rbuf = *cookie;
+	if (rbuf)
+		goto have_rbuf;
+
+	add_wait_queue(&tty->read_wait, &wait);
+
+	for (;;) {
+		if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+			ret = -EIO;
+			break;
+		}
+		if (tty_hung_up_p(file))
+			break;
+
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
+		if (rbuf)
+			break;
+
+		/* no data */
+		if (tty_io_nonblock(tty, file)) {
+			ret = -EAGAIN;
+			break;
+		}
+
+		schedule();
+
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+	}
+
+	remove_wait_queue(&tty->read_wait, &wait);
+	__set_current_state(TASK_RUNNING);
+
+	if (!rbuf)
+		return ret;
+	*cookie = rbuf;
+
+have_rbuf:
+	/* Have we used it up entirely? */
+	if (offset >= rbuf->count)
+		goto done_with_rbuf;
+
+	/* More data to go, but can't copy any more? EOVERFLOW */
+	ret = -EOVERFLOW;
+	if (!nr)
+		goto done_with_rbuf;
+
+	/* Copy as much data as possible */
+	ret = rbuf->count - offset;
+	if (ret > nr)
+		ret = nr;
+	memcpy(kbuf, rbuf->buf+offset, ret);
+	offset += ret;
+
+	/* If we still have data left, we leave the rbuf in the cookie */
+	if (offset < rbuf->count)
+		return ret;
+
+done_with_rbuf:
+	*cookie = NULL;
+
+	if (n_hdlc->rx_free_buf_list.count > DEFAULT_RX_BUF_COUNT)
+		kfree(rbuf);
+	else
+		n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, rbuf);
+
+	return ret;
+
+}	/* end of n_hdlc_tty_read() */
+
+/**
+ * n_hdlc_tty_write - write a single frame of data to device
+ * @tty: pointer to associated tty device instance data
+ * @file: pointer to file object data
+ * @data: pointer to transmit data (one frame)
+ * @count: size of transmit frame in bytes
+ *
+ * Returns the number of bytes written (or error code).
+ */
+static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
+				const u8 *data, size_t count)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+	int error = 0;
+	DECLARE_WAITQUEUE(wait, current);
+	struct n_hdlc_buf *tbuf;
+
+	pr_debug("%s() called count=%zd\n", __func__, count);
+
+	/* verify frame size */
+	if (count > maxframe) {
+		pr_debug("%s: truncating user packet from %zu to %d\n",
+				__func__, count, maxframe);
+		count = maxframe;
+	}
+
+	add_wait_queue(&tty->write_wait, &wait);
+
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);
+		if (tbuf)
+			break;
+
+		if (tty_io_nonblock(tty, file)) {
+			error = -EAGAIN;
+			break;
+		}
+		schedule();
+
+		if (signal_pending(current)) {
+			error = -EINTR;
+			break;
+		}
+	}
+
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&tty->write_wait, &wait);
+
+	if (!error) {
+		/* Retrieve the user's buffer */
+		memcpy(tbuf->buf, data, count);
+
+		/* Send the data */
+		tbuf->count = error = count;
+		n_hdlc_buf_put(&n_hdlc->tx_buf_list, tbuf);
+		n_hdlc_send_frames(n_hdlc, tty);
+	}
+
+	return error;
+
+}	/* end of n_hdlc_tty_write() */
+
+/**
+ * n_hdlc_tty_ioctl - process IOCTL system call for the tty device.
+ * @tty: pointer to tty instance data
+ * @cmd: IOCTL command code
+ * @arg: argument for IOCTL call (cmd dependent)
+ *
+ * Returns command dependent result.
+ */
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
+			    unsigned long arg)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+	int error = 0;
+	int count;
+	unsigned long flags;
+	struct n_hdlc_buf *buf = NULL;
+
+	pr_debug("%s() called %d\n", __func__, cmd);
+
+	switch (cmd) {
+	case FIONREAD:
+		/* report count of read data available */
+		/* in next available frame (if any) */
+		spin_lock_irqsave(&n_hdlc->rx_buf_list.spinlock, flags);
+		buf = list_first_entry_or_null(&n_hdlc->rx_buf_list.list,
+						struct n_hdlc_buf, list_item);
+		if (buf)
+			count = buf->count;
+		else
+			count = 0;
+		spin_unlock_irqrestore(&n_hdlc->rx_buf_list.spinlock, flags);
+		error = put_user(count, (int __user *)arg);
+		break;
+
+	case TIOCOUTQ:
+		/* get the pending tx byte count in the driver */
+		count = tty_chars_in_buffer(tty);
+		/* add size of next output frame in queue */
+		spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+		buf = list_first_entry_or_null(&n_hdlc->tx_buf_list.list,
+						struct n_hdlc_buf, list_item);
+		if (buf)
+			count += buf->count;
+		spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+		error = put_user(count, (int __user *)arg);
+		break;
+
+	case TCFLSH:
+		switch (arg) {
+		case TCIOFLUSH:
+		case TCOFLUSH:
+			flush_tx_queue(tty);
+		}
+		fallthrough;	/* to default */
+
+	default:
+		error = n_tty_ioctl_helper(tty, cmd, arg);
+		break;
+	}
+	return error;
+
+}	/* end of n_hdlc_tty_ioctl() */
+
+/**
+ * n_hdlc_tty_poll - TTY callback for poll system call
+ * @tty: pointer to tty instance data
+ * @filp: pointer to open file object for device
+ * @wait: wait queue for operations
+ *
+ * Determine which operations (read/write) will not block and return info
+ * to caller.
+ * Returns a bit mask containing info on which ops will not block.
+ */
+static __poll_t n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
+				    poll_table *wait)
+{
+	struct n_hdlc *n_hdlc = tty->disc_data;
+	__poll_t mask = 0;
+
+	/*
+	 * queue the current process into any wait queue that may awaken in the
+	 * future (read and write)
+	 */
+	poll_wait(filp, &tty->read_wait, wait);
+	poll_wait(filp, &tty->write_wait, wait);
+
+	/* set bits for operations that won't block */
+	if (!list_empty(&n_hdlc->rx_buf_list.list))
+		mask |= EPOLLIN | EPOLLRDNORM;	/* readable */
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		mask |= EPOLLHUP;
+	if (tty_hung_up_p(filp))
+		mask |= EPOLLHUP;
+	if (!tty_is_writelocked(tty) &&
+			!list_empty(&n_hdlc->tx_free_buf_list.list))
+		mask |= EPOLLOUT | EPOLLWRNORM;	/* writable */
+
+	return mask;
+}	/* end of n_hdlc_tty_poll() */
+
+static void n_hdlc_alloc_buf(struct n_hdlc_buf_list *list, unsigned int count,
+		const char *name)
+{
+	struct n_hdlc_buf *buf;
+	unsigned int i;
+
+	for (i = 0; i < count; i++) {
+		buf = kmalloc(struct_size(buf, buf, maxframe), GFP_KERNEL);
+		if (!buf) {
+			pr_debug("%s(), kmalloc() failed for %s buffer %u\n",
+					__func__, name, i);
+			return;
+		}
+		n_hdlc_buf_put(list, buf);
+	}
+}
+
+/**
+ * n_hdlc_alloc - allocate an n_hdlc instance data structure
+ *
+ * Returns a pointer to newly created structure if success, otherwise %NULL
+ */
+static struct n_hdlc *n_hdlc_alloc(void)
+{
+	struct n_hdlc *n_hdlc = kzalloc(sizeof(*n_hdlc), GFP_KERNEL);
+
+	if (!n_hdlc)
+		return NULL;
+
+	spin_lock_init(&n_hdlc->rx_free_buf_list.spinlock);
+	spin_lock_init(&n_hdlc->tx_free_buf_list.spinlock);
+	spin_lock_init(&n_hdlc->rx_buf_list.spinlock);
+	spin_lock_init(&n_hdlc->tx_buf_list.spinlock);
+
+	INIT_LIST_HEAD(&n_hdlc->rx_free_buf_list.list);
+	INIT_LIST_HEAD(&n_hdlc->tx_free_buf_list.list);
+	INIT_LIST_HEAD(&n_hdlc->rx_buf_list.list);
+	INIT_LIST_HEAD(&n_hdlc->tx_buf_list.list);
+
+	n_hdlc_alloc_buf(&n_hdlc->rx_free_buf_list, DEFAULT_RX_BUF_COUNT, "rx");
+	n_hdlc_alloc_buf(&n_hdlc->tx_free_buf_list, DEFAULT_TX_BUF_COUNT, "tx");
+
+	return n_hdlc;
+
+}	/* end of n_hdlc_alloc() */
+
+/**
+ * n_hdlc_buf_return - put the HDLC buffer after the head of the specified list
+ * @buf_list: pointer to the buffer list
+ * @buf: pointer to the buffer
+ */
+static void n_hdlc_buf_return(struct n_hdlc_buf_list *buf_list,
+						struct n_hdlc_buf *buf)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&buf_list->spinlock, flags);
+
+	list_add(&buf->list_item, &buf_list->list);
+	buf_list->count++;
+
+	spin_unlock_irqrestore(&buf_list->spinlock, flags);
+}
+
+/**
+ * n_hdlc_buf_put - add specified HDLC buffer to tail of specified list
+ * @buf_list: pointer to buffer list
+ * @buf: pointer to buffer
+ */
+static void n_hdlc_buf_put(struct n_hdlc_buf_list *buf_list,
+			   struct n_hdlc_buf *buf)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&buf_list->spinlock, flags);
+
+	list_add_tail(&buf->list_item, &buf_list->list);
+	buf_list->count++;
+
+	spin_unlock_irqrestore(&buf_list->spinlock, flags);
+}	/* end of n_hdlc_buf_put() */
+
+/**
+ * n_hdlc_buf_get - remove and return an HDLC buffer from list
+ * @buf_list: pointer to HDLC buffer list
+ *
+ * Remove and return an HDLC buffer from the head of the specified HDLC buffer
+ * list.
+ * Returns a pointer to HDLC buffer if available, otherwise %NULL.
+ */
+static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *buf_list)
+{
+	unsigned long flags;
+	struct n_hdlc_buf *buf;
+
+	spin_lock_irqsave(&buf_list->spinlock, flags);
+
+	buf = list_first_entry_or_null(&buf_list->list,
+						struct n_hdlc_buf, list_item);
+	if (buf) {
+		list_del(&buf->list_item);
+		buf_list->count--;
+	}
+
+	spin_unlock_irqrestore(&buf_list->spinlock, flags);
+	return buf;
+}	/* end of n_hdlc_buf_get() */
+
+static struct tty_ldisc_ops n_hdlc_ldisc = {
+	.owner		= THIS_MODULE,
+	.num		= N_HDLC,
+	.name		= "hdlc",
+	.open		= n_hdlc_tty_open,
+	.close		= n_hdlc_tty_close,
+	.read		= n_hdlc_tty_read,
+	.write		= n_hdlc_tty_write,
+	.ioctl		= n_hdlc_tty_ioctl,
+	.poll		= n_hdlc_tty_poll,
+	.receive_buf	= n_hdlc_tty_receive,
+	.write_wakeup	= n_hdlc_tty_wakeup,
+	.flush_buffer   = flush_rx_queue,
+};
+
+static int __init n_hdlc_init(void)
+{
+	int status;
+
+	/* range check maxframe arg */
+	maxframe = clamp(maxframe, 4096, MAX_HDLC_FRAME_SIZE);
+
+	status = tty_register_ldisc(&n_hdlc_ldisc);
+	if (!status)
+		pr_info("N_HDLC line discipline registered with maxframe=%d\n",
+				maxframe);
+	else
+		pr_err("N_HDLC: error registering line discipline: %d\n",
+				status);
+
+	return status;
+
+}	/* end of init_module() */
+
+static void __exit n_hdlc_exit(void)
+{
+	tty_unregister_ldisc(&n_hdlc_ldisc);
+}
+
+module_init(n_hdlc_init);
+module_exit(n_hdlc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul Fulghum paulkf@microgate.com");
+module_param(maxframe, int, 0);
+MODULE_ALIAS_LDISC(N_HDLC);
diff --git a/drivers/tty/n_null.c b/drivers/tty/n_null.c
new file mode 100644
index 000000000..5a429d923
--- /dev/null
+++ b/drivers/tty/n_null.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+
+/*
+ *  n_null.c - Null line discipline used in the failure path
+ *
+ *  Copyright (C) Intel 2017
+ */
+
+static ssize_t n_null_read(struct tty_struct *tty, struct file *file, u8 *buf,
+			   size_t nr, void **cookie, unsigned long offset)
+{
+	return -EOPNOTSUPP;
+}
+
+static ssize_t n_null_write(struct tty_struct *tty, struct file *file,
+			    const u8 *buf, size_t nr)
+{
+	return -EOPNOTSUPP;
+}
+
+static struct tty_ldisc_ops null_ldisc = {
+	.owner		=	THIS_MODULE,
+	.num		=	N_NULL,
+	.name		=	"n_null",
+	.read		=	n_null_read,
+	.write		=	n_null_write,
+};
+
+static int __init n_null_init(void)
+{
+	BUG_ON(tty_register_ldisc(&null_ldisc));
+	return 0;
+}
+
+static void __exit n_null_exit(void)
+{
+	tty_unregister_ldisc(&null_ldisc);
+}
+
+module_init(n_null_init);
+module_exit(n_null_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alan Cox");
+MODULE_ALIAS_LDISC(N_NULL);
+MODULE_DESCRIPTION("Null ldisc driver");
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
new file mode 100644
index 000000000..6c9a408d6
--- /dev/null
+++ b/drivers/tty/n_tty.c
@@ -0,0 +1,2555 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * n_tty.c --- implements the N_TTY line discipline.
+ *
+ * This code used to be in tty_io.c, but things are getting hairy
+ * enough that it made sense to split things off.  (The N_TTY
+ * processing has changed so much that it's hardly recognizable,
+ * anyway...)
+ *
+ * Note that the open routine for N_TTY is guaranteed never to return
+ * an error.  This is because Linux will fall back to setting a line
+ * to N_TTY if it can not switch to any other line discipline.
+ *
+ * Written by Theodore Ts'o, Copyright 1994.
+ *
+ * This file also contains code originally written by Linus Torvalds,
+ * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
+ *
+ * Reduced memory usage for older ARM systems  - Russell King.
+ *
+ * 2000/01/20   Fixed SMP locking on put_tty_queue using bits of
+ *		the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
+ *		who actually finally proved there really was a race.
+ *
+ * 2002/03/18   Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
+ *		waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
+ *		Also fixed a bug in BLOCKING mode where n_tty_write returns
+ *		EAGAIN
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/jiffies.h>
+#include <linux/math.h>
+#include <linux/poll.h>
+#include <linux/ratelimit.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tty.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+
+#include "tty.h"
+
+/*
+ * Until this number of characters is queued in the xmit buffer, select will
+ * return "we have room for writes".
+ */
+#define WAKEUP_CHARS 256
+
+/*
+ * This defines the low- and high-watermarks for throttling and
+ * unthrottling the TTY driver.  These watermarks are used for
+ * controlling the space in the read buffer.
+ */
+#define TTY_THRESHOLD_THROTTLE		128 /* now based on remaining room */
+#define TTY_THRESHOLD_UNTHROTTLE	128
+
+/*
+ * Special byte codes used in the echo buffer to represent operations
+ * or special handling of characters.  Bytes in the echo buffer that
+ * are not part of such special blocks are treated as normal character
+ * codes.
+ */
+#define ECHO_OP_START 0xff
+#define ECHO_OP_MOVE_BACK_COL 0x80
+#define ECHO_OP_SET_CANON_COL 0x81
+#define ECHO_OP_ERASE_TAB 0x82
+
+#define ECHO_COMMIT_WATERMARK	256
+#define ECHO_BLOCK		256
+#define ECHO_DISCARD_WATERMARK	N_TTY_BUF_SIZE - (ECHO_BLOCK + 32)
+
+
+#undef N_TTY_TRACE
+#ifdef N_TTY_TRACE
+# define n_tty_trace(f, args...)	trace_printk(f, ##args)
+#else
+# define n_tty_trace(f, args...)	no_printk(f, ##args)
+#endif
+
+struct n_tty_data {
+	/* producer-published */
+	size_t read_head;
+	size_t commit_head;
+	size_t canon_head;
+	size_t echo_head;
+	size_t echo_commit;
+	size_t echo_mark;
+	DECLARE_BITMAP(char_map, 256);
+
+	/* private to n_tty_receive_overrun (single-threaded) */
+	unsigned long overrun_time;
+	unsigned int num_overrun;
+
+	/* non-atomic */
+	bool no_room;
+
+	/* must hold exclusive termios_rwsem to reset these */
+	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
+	unsigned char push:1;
+
+	/* shared by producer and consumer */
+	u8 read_buf[N_TTY_BUF_SIZE];
+	DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
+	u8 echo_buf[N_TTY_BUF_SIZE];
+
+	/* consumer-published */
+	size_t read_tail;
+	size_t line_start;
+
+	/* # of chars looked ahead (to find software flow control chars) */
+	size_t lookahead_count;
+
+	/* protected by output lock */
+	unsigned int column;
+	unsigned int canon_column;
+	size_t echo_tail;
+
+	struct mutex atomic_read_lock;
+	struct mutex output_lock;
+};
+
+#define MASK(x) ((x) & (N_TTY_BUF_SIZE - 1))
+
+static inline size_t read_cnt(struct n_tty_data *ldata)
+{
+	return ldata->read_head - ldata->read_tail;
+}
+
+static inline u8 read_buf(struct n_tty_data *ldata, size_t i)
+{
+	return ldata->read_buf[MASK(i)];
+}
+
+static inline u8 *read_buf_addr(struct n_tty_data *ldata, size_t i)
+{
+	return &ldata->read_buf[MASK(i)];
+}
+
+static inline u8 echo_buf(struct n_tty_data *ldata, size_t i)
+{
+	smp_rmb(); /* Matches smp_wmb() in add_echo_byte(). */
+	return ldata->echo_buf[MASK(i)];
+}
+
+static inline u8 *echo_buf_addr(struct n_tty_data *ldata, size_t i)
+{
+	return &ldata->echo_buf[MASK(i)];
+}
+
+/* If we are not echoing the data, perhaps this is a secret so erase it */
+static void zero_buffer(const struct tty_struct *tty, u8 *buffer, size_t size)
+{
+	if (L_ICANON(tty) && !L_ECHO(tty))
+		memset(buffer, 0, size);
+}
+
+static void tty_copy(const struct tty_struct *tty, void *to, size_t tail,
+		     size_t n)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	size_t size = N_TTY_BUF_SIZE - tail;
+	void *from = read_buf_addr(ldata, tail);
+
+	if (n > size) {
+		tty_audit_add_data(tty, from, size);
+		memcpy(to, from, size);
+		zero_buffer(tty, from, size);
+		to += size;
+		n -= size;
+		from = ldata->read_buf;
+	}
+
+	tty_audit_add_data(tty, from, n);
+	memcpy(to, from, n);
+	zero_buffer(tty, from, n);
+}
+
+/**
+ * n_tty_kick_worker - start input worker (if required)
+ * @tty: terminal
+ *
+ * Re-schedules the flip buffer work if it may have stopped.
+ *
+ * Locking:
+ *  * Caller holds exclusive %termios_rwsem, or
+ *  * n_tty_read()/consumer path:
+ *	holds non-exclusive %termios_rwsem
+ */
+static void n_tty_kick_worker(const struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	/* Did the input worker stop? Restart it */
+	if (unlikely(READ_ONCE(ldata->no_room))) {
+		WRITE_ONCE(ldata->no_room, 0);
+
+		WARN_RATELIMIT(tty->port->itty == NULL,
+				"scheduling with invalid itty\n");
+		/* see if ldisc has been killed - if so, this means that
+		 * even though the ldisc has been halted and ->buf.work
+		 * cancelled, ->buf.work is about to be rescheduled
+		 */
+		WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags),
+			       "scheduling buffer work for halted ldisc\n");
+		tty_buffer_restart_work(tty->port);
+	}
+}
+
+static ssize_t chars_in_buffer(const struct tty_struct *tty)
+{
+	const struct n_tty_data *ldata = tty->disc_data;
+	size_t head = ldata->icanon ? ldata->canon_head : ldata->commit_head;
+
+	return head - ldata->read_tail;
+}
+
+/**
+ * n_tty_write_wakeup	-	asynchronous I/O notifier
+ * @tty: tty device
+ *
+ * Required for the ptys, serial driver etc. since processes that attach
+ * themselves to the master and rely on ASYNC IO must be woken up.
+ */
+static void n_tty_write_wakeup(struct tty_struct *tty)
+{
+	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
+}
+
+static void n_tty_check_throttle(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	/*
+	 * Check the remaining room for the input canonicalization
+	 * mode.  We don't want to throttle the driver if we're in
+	 * canonical mode and don't have a newline yet!
+	 */
+	if (ldata->icanon && ldata->canon_head == ldata->read_tail)
+		return;
+
+	while (1) {
+		int throttled;
+		tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
+		if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE)
+			break;
+		throttled = tty_throttle_safe(tty);
+		if (!throttled)
+			break;
+	}
+	__tty_set_flow_change(tty, 0);
+}
+
+static void n_tty_check_unthrottle(struct tty_struct *tty)
+{
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
+		if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
+			return;
+		n_tty_kick_worker(tty);
+		tty_wakeup(tty->link);
+		return;
+	}
+
+	/* If there is enough space in the read buffer now, let the
+	 * low-level driver know. We use chars_in_buffer() to
+	 * check the buffer, as it now knows about canonical mode.
+	 * Otherwise, if the driver is throttled and the line is
+	 * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
+	 * we won't get any more characters.
+	 */
+
+	while (1) {
+		int unthrottled;
+		tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
+		if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
+			break;
+		n_tty_kick_worker(tty);
+		unthrottled = tty_unthrottle_safe(tty);
+		if (!unthrottled)
+			break;
+	}
+	__tty_set_flow_change(tty, 0);
+}
+
+/**
+ * put_tty_queue		-	add character to tty
+ * @c: character
+ * @ldata: n_tty data
+ *
+ * Add a character to the tty read_buf queue.
+ *
+ * Locking:
+ *  * n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive %termios_rwsem
+ */
+static inline void put_tty_queue(u8 c, struct n_tty_data *ldata)
+{
+	*read_buf_addr(ldata, ldata->read_head) = c;
+	ldata->read_head++;
+}
+
+/**
+ * reset_buffer_flags	-	reset buffer state
+ * @ldata: line disc data to reset
+ *
+ * Reset the read buffer counters and clear the flags. Called from
+ * n_tty_open() and n_tty_flush_buffer().
+ *
+ * Locking:
+ *  * caller holds exclusive %termios_rwsem, or
+ *  * (locking is not required)
+ */
+static void reset_buffer_flags(struct n_tty_data *ldata)
+{
+	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
+	ldata->commit_head = 0;
+	ldata->line_start = 0;
+
+	ldata->erasing = 0;
+	bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
+	ldata->push = 0;
+
+	ldata->lookahead_count = 0;
+}
+
+static void n_tty_packet_mode_flush(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	if (tty->link->ctrl.packet) {
+		spin_lock_irqsave(&tty->ctrl.lock, flags);
+		tty->ctrl.pktstatus |= TIOCPKT_FLUSHREAD;
+		spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+		wake_up_interruptible(&tty->link->read_wait);
+	}
+}
+
+/**
+ * n_tty_flush_buffer	-	clean input queue
+ * @tty: terminal device
+ *
+ * Flush the input buffer. Called when the tty layer wants the buffer flushed
+ * (eg at hangup) or when the %N_TTY line discipline internally has to clean
+ * the pending queue (for example some signals).
+ *
+ * Holds %termios_rwsem to exclude producer/consumer while buffer indices are
+ * reset.
+ *
+ * Locking: %ctrl.lock, exclusive %termios_rwsem
+ */
+static void n_tty_flush_buffer(struct tty_struct *tty)
+{
+	down_write(&tty->termios_rwsem);
+	reset_buffer_flags(tty->disc_data);
+	n_tty_kick_worker(tty);
+
+	if (tty->link)
+		n_tty_packet_mode_flush(tty);
+	up_write(&tty->termios_rwsem);
+}
+
+/**
+ * is_utf8_continuation	-	utf8 multibyte check
+ * @c: byte to check
+ *
+ * Returns: true if the utf8 character @c is a multibyte continuation
+ * character. We use this to correctly compute the on-screen size of the
+ * character when printing.
+ */
+static inline int is_utf8_continuation(u8 c)
+{
+	return (c & 0xc0) == 0x80;
+}
+
+/**
+ * is_continuation	-	multibyte check
+ * @c: byte to check
+ * @tty: terminal device
+ *
+ * Returns: true if the utf8 character @c is a multibyte continuation character
+ * and the terminal is in unicode mode.
+ */
+static inline int is_continuation(u8 c, const struct tty_struct *tty)
+{
+	return I_IUTF8(tty) && is_utf8_continuation(c);
+}
+
+/**
+ * do_output_char	-	output one character
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
+ * @space: space available in tty driver write buffer
+ *
+ * This is a helper function that handles one output character (including
+ * special characters like TAB, CR, LF, etc.), doing OPOST processing and
+ * putting the results in the tty driver's write buffer.
+ *
+ * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY and NLDLY.
+ * They simply aren't relevant in the world today. If you ever need them, add
+ * them here.
+ *
+ * Returns: the number of bytes of buffer space used or -1 if no space left.
+ *
+ * Locking: should be called under the %output_lock to protect the column state
+ * and space left in the buffer.
+ */
+static int do_output_char(u8 c, struct tty_struct *tty, int space)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	int	spaces;
+
+	if (!space)
+		return -1;
+
+	switch (c) {
+	case '\n':
+		if (O_ONLRET(tty))
+			ldata->column = 0;
+		if (O_ONLCR(tty)) {
+			if (space < 2)
+				return -1;
+			ldata->canon_column = ldata->column = 0;
+			tty->ops->write(tty, "\r\n", 2);
+			return 2;
+		}
+		ldata->canon_column = ldata->column;
+		break;
+	case '\r':
+		if (O_ONOCR(tty) && ldata->column == 0)
+			return 0;
+		if (O_OCRNL(tty)) {
+			c = '\n';
+			if (O_ONLRET(tty))
+				ldata->canon_column = ldata->column = 0;
+			break;
+		}
+		ldata->canon_column = ldata->column = 0;
+		break;
+	case '\t':
+		spaces = 8 - (ldata->column & 7);
+		if (O_TABDLY(tty) == XTABS) {
+			if (space < spaces)
+				return -1;
+			ldata->column += spaces;
+			tty->ops->write(tty, "        ", spaces);
+			return spaces;
+		}
+		ldata->column += spaces;
+		break;
+	case '\b':
+		if (ldata->column > 0)
+			ldata->column--;
+		break;
+	default:
+		if (!iscntrl(c)) {
+			if (O_OLCUC(tty))
+				c = toupper(c);
+			if (!is_continuation(c, tty))
+				ldata->column++;
+		}
+		break;
+	}
+
+	tty_put_char(tty, c);
+	return 1;
+}
+
+/**
+ * process_output	-	output post processor
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
+ *
+ * Output one character with OPOST processing.
+ *
+ * Returns: -1 when the output device is full and the character must be
+ * retried.
+ *
+ * Locking: %output_lock to protect column state and space left (also, this is
+ *called from n_tty_write() under the tty layer write lock).
+ */
+static int process_output(u8 c, struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	int	space, retval;
+
+	mutex_lock(&ldata->output_lock);
+
+	space = tty_write_room(tty);
+	retval = do_output_char(c, tty, space);
+
+	mutex_unlock(&ldata->output_lock);
+	if (retval < 0)
+		return -1;
+	else
+		return 0;
+}
+
+/**
+ * process_output_block	-	block post processor
+ * @tty: terminal device
+ * @buf: character buffer
+ * @nr: number of bytes to output
+ *
+ * Output a block of characters with OPOST processing.
+ *
+ * This path is used to speed up block console writes, among other things when
+ * processing blocks of output data. It handles only the simple cases normally
+ * found and helps to generate blocks of symbols for the console driver and
+ * thus improve performance.
+ *
+ * Returns: the number of characters output.
+ *
+ * Locking: %output_lock to protect column state and space left (also, this is
+ * called from n_tty_write() under the tty layer write lock).
+ */
+static ssize_t process_output_block(struct tty_struct *tty,
+				    const u8 *buf, unsigned int nr)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	int	space;
+	int	i;
+	const u8 *cp;
+
+	mutex_lock(&ldata->output_lock);
+
+	space = tty_write_room(tty);
+	if (space <= 0) {
+		mutex_unlock(&ldata->output_lock);
+		return space;
+	}
+	if (nr > space)
+		nr = space;
+
+	for (i = 0, cp = buf; i < nr; i++, cp++) {
+		u8 c = *cp;
+
+		switch (c) {
+		case '\n':
+			if (O_ONLRET(tty))
+				ldata->column = 0;
+			if (O_ONLCR(tty))
+				goto break_out;
+			ldata->canon_column = ldata->column;
+			break;
+		case '\r':
+			if (O_ONOCR(tty) && ldata->column == 0)
+				goto break_out;
+			if (O_OCRNL(tty))
+				goto break_out;
+			ldata->canon_column = ldata->column = 0;
+			break;
+		case '\t':
+			goto break_out;
+		case '\b':
+			if (ldata->column > 0)
+				ldata->column--;
+			break;
+		default:
+			if (!iscntrl(c)) {
+				if (O_OLCUC(tty))
+					goto break_out;
+				if (!is_continuation(c, tty))
+					ldata->column++;
+			}
+			break;
+		}
+	}
+break_out:
+	i = tty->ops->write(tty, buf, i);
+
+	mutex_unlock(&ldata->output_lock);
+	return i;
+}
+
+static int n_tty_process_echo_ops(struct tty_struct *tty, size_t *tail,
+				  int space)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	u8 op;
+
+	/*
+	 * Since add_echo_byte() is called without holding output_lock, we
+	 * might see only portion of multi-byte operation.
+	 */
+	if (MASK(ldata->echo_commit) == MASK(*tail + 1))
+		return -ENODATA;
+
+	/*
+	 * If the buffer byte is the start of a multi-byte operation, get the
+	 * next byte, which is either the op code or a control character value.
+	 */
+	op = echo_buf(ldata, *tail + 1);
+
+	switch (op) {
+	case ECHO_OP_ERASE_TAB: {
+		unsigned int num_chars, num_bs;
+
+		if (MASK(ldata->echo_commit) == MASK(*tail + 2))
+			return -ENODATA;
+
+		num_chars = echo_buf(ldata, *tail + 2);
+
+		/*
+		 * Determine how many columns to go back in order to erase the
+		 * tab. This depends on the number of columns used by other
+		 * characters within the tab area. If this (modulo 8) count is
+		 * from the start of input rather than from a previous tab, we
+		 * offset by canon column. Otherwise, tab spacing is normal.
+		 */
+		if (!(num_chars & 0x80))
+			num_chars += ldata->canon_column;
+		num_bs = 8 - (num_chars & 7);
+
+		if (num_bs > space)
+			return -ENOSPC;
+
+		space -= num_bs;
+		while (num_bs--) {
+			tty_put_char(tty, '\b');
+			if (ldata->column > 0)
+				ldata->column--;
+		}
+		*tail += 3;
+		break;
+	}
+	case ECHO_OP_SET_CANON_COL:
+		ldata->canon_column = ldata->column;
+		*tail += 2;
+		break;
+
+	case ECHO_OP_MOVE_BACK_COL:
+		if (ldata->column > 0)
+			ldata->column--;
+		*tail += 2;
+		break;
+
+	case ECHO_OP_START:
+		/* This is an escaped echo op start code */
+		if (!space)
+			return -ENOSPC;
+
+		tty_put_char(tty, ECHO_OP_START);
+		ldata->column++;
+		space--;
+		*tail += 2;
+		break;
+
+	default:
+		/*
+		 * If the op is not a special byte code, it is a ctrl char
+		 * tagged to be echoed as "^X" (where X is the letter
+		 * representing the control char). Note that we must ensure
+		 * there is enough space for the whole ctrl pair.
+		 */
+		if (space < 2)
+			return -ENOSPC;
+
+		tty_put_char(tty, '^');
+		tty_put_char(tty, op ^ 0100);
+		ldata->column += 2;
+		space -= 2;
+		*tail += 2;
+		break;
+	}
+
+	return space;
+}
+
+/**
+ * __process_echoes	-	write pending echo characters
+ * @tty: terminal device
+ *
+ * Write previously buffered echo (and other ldisc-generated) characters to the
+ * tty.
+ *
+ * Characters generated by the ldisc (including echoes) need to be buffered
+ * because the driver's write buffer can fill during heavy program output.
+ * Echoing straight to the driver will often fail under these conditions,
+ * causing lost characters and resulting mismatches of ldisc state information.
+ *
+ * Since the ldisc state must represent the characters actually sent to the
+ * driver at the time of the write, operations like certain changes in column
+ * state are also saved in the buffer and executed here.
+ *
+ * A circular fifo buffer is used so that the most recent characters are
+ * prioritized. Also, when control characters are echoed with a prefixed "^",
+ * the pair is treated atomically and thus not separated.
+ *
+ * Locking: callers must hold %output_lock.
+ */
+static size_t __process_echoes(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	int	space, old_space;
+	size_t tail;
+	u8 c;
+
+	old_space = space = tty_write_room(tty);
+
+	tail = ldata->echo_tail;
+	while (MASK(ldata->echo_commit) != MASK(tail)) {
+		c = echo_buf(ldata, tail);
+		if (c == ECHO_OP_START) {
+			int ret = n_tty_process_echo_ops(tty, &tail, space);
+			if (ret == -ENODATA)
+				goto not_yet_stored;
+			if (ret < 0)
+				break;
+			space = ret;
+		} else {
+			if (O_OPOST(tty)) {
+				int retval = do_output_char(c, tty, space);
+				if (retval < 0)
+					break;
+				space -= retval;
+			} else {
+				if (!space)
+					break;
+				tty_put_char(tty, c);
+				space -= 1;
+			}
+			tail += 1;
+		}
+	}
+
+	/* If the echo buffer is nearly full (so that the possibility exists
+	 * of echo overrun before the next commit), then discard enough
+	 * data at the tail to prevent a subsequent overrun */
+	while (ldata->echo_commit > tail &&
+	       ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) {
+		if (echo_buf(ldata, tail) == ECHO_OP_START) {
+			if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB)
+				tail += 3;
+			else
+				tail += 2;
+		} else
+			tail++;
+	}
+
+ not_yet_stored:
+	ldata->echo_tail = tail;
+	return old_space - space;
+}
+
+static void commit_echoes(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	size_t nr, old, echoed;
+	size_t head;
+
+	mutex_lock(&ldata->output_lock);
+	head = ldata->echo_head;
+	ldata->echo_mark = head;
+	old = ldata->echo_commit - ldata->echo_tail;
+
+	/* Process committed echoes if the accumulated # of bytes
+	 * is over the threshold (and try again each time another
+	 * block is accumulated) */
+	nr = head - ldata->echo_tail;
+	if (nr < ECHO_COMMIT_WATERMARK ||
+	    (nr % ECHO_BLOCK > old % ECHO_BLOCK)) {
+		mutex_unlock(&ldata->output_lock);
+		return;
+	}
+
+	ldata->echo_commit = head;
+	echoed = __process_echoes(tty);
+	mutex_unlock(&ldata->output_lock);
+
+	if (echoed && tty->ops->flush_chars)
+		tty->ops->flush_chars(tty);
+}
+
+static void process_echoes(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	size_t echoed;
+
+	if (ldata->echo_mark == ldata->echo_tail)
+		return;
+
+	mutex_lock(&ldata->output_lock);
+	ldata->echo_commit = ldata->echo_mark;
+	echoed = __process_echoes(tty);
+	mutex_unlock(&ldata->output_lock);
+
+	if (echoed && tty->ops->flush_chars)
+		tty->ops->flush_chars(tty);
+}
+
+/* NB: echo_mark and echo_head should be equivalent here */
+static void flush_echoes(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
+	    ldata->echo_commit == ldata->echo_head)
+		return;
+
+	mutex_lock(&ldata->output_lock);
+	ldata->echo_commit = ldata->echo_head;
+	__process_echoes(tty);
+	mutex_unlock(&ldata->output_lock);
+}
+
+/**
+ * add_echo_byte	-	add a byte to the echo buffer
+ * @c: unicode byte to echo
+ * @ldata: n_tty data
+ *
+ * Add a character or operation byte to the echo buffer.
+ */
+static inline void add_echo_byte(u8 c, struct n_tty_data *ldata)
+{
+	*echo_buf_addr(ldata, ldata->echo_head) = c;
+	smp_wmb(); /* Matches smp_rmb() in echo_buf(). */
+	ldata->echo_head++;
+}
+
+/**
+ * echo_move_back_col	-	add operation to move back a column
+ * @ldata: n_tty data
+ *
+ * Add an operation to the echo buffer to move back one column.
+ */
+static void echo_move_back_col(struct n_tty_data *ldata)
+{
+	add_echo_byte(ECHO_OP_START, ldata);
+	add_echo_byte(ECHO_OP_MOVE_BACK_COL, ldata);
+}
+
+/**
+ * echo_set_canon_col	-	add operation to set the canon column
+ * @ldata: n_tty data
+ *
+ * Add an operation to the echo buffer to set the canon column to the current
+ * column.
+ */
+static void echo_set_canon_col(struct n_tty_data *ldata)
+{
+	add_echo_byte(ECHO_OP_START, ldata);
+	add_echo_byte(ECHO_OP_SET_CANON_COL, ldata);
+}
+
+/**
+ * echo_erase_tab	-	add operation to erase a tab
+ * @num_chars: number of character columns already used
+ * @after_tab: true if num_chars starts after a previous tab
+ * @ldata: n_tty data
+ *
+ * Add an operation to the echo buffer to erase a tab.
+ *
+ * Called by the eraser function, which knows how many character columns have
+ * been used since either a previous tab or the start of input. This
+ * information will be used later, along with canon column (if applicable), to
+ * go back the correct number of columns.
+ */
+static void echo_erase_tab(unsigned int num_chars, int after_tab,
+			   struct n_tty_data *ldata)
+{
+	add_echo_byte(ECHO_OP_START, ldata);
+	add_echo_byte(ECHO_OP_ERASE_TAB, ldata);
+
+	/* We only need to know this modulo 8 (tab spacing) */
+	num_chars &= 7;
+
+	/* Set the high bit as a flag if num_chars is after a previous tab */
+	if (after_tab)
+		num_chars |= 0x80;
+
+	add_echo_byte(num_chars, ldata);
+}
+
+/**
+ * echo_char_raw	-	echo a character raw
+ * @c: unicode byte to echo
+ * @ldata: line disc data
+ *
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the &tty_driver.receive_buf() path.
+ *
+ * This variant does not treat control characters specially.
+ */
+static void echo_char_raw(u8 c, struct n_tty_data *ldata)
+{
+	if (c == ECHO_OP_START) {
+		add_echo_byte(ECHO_OP_START, ldata);
+		add_echo_byte(ECHO_OP_START, ldata);
+	} else {
+		add_echo_byte(c, ldata);
+	}
+}
+
+/**
+ * echo_char		-	echo a character
+ * @c: unicode byte to echo
+ * @tty: terminal device
+ *
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the &tty_driver.receive_buf() path.
+ *
+ * This variant tags control characters to be echoed as "^X" (where X is the
+ * letter representing the control char).
+ */
+static void echo_char(u8 c, const struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (c == ECHO_OP_START) {
+		add_echo_byte(ECHO_OP_START, ldata);
+		add_echo_byte(ECHO_OP_START, ldata);
+	} else {
+		if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t')
+			add_echo_byte(ECHO_OP_START, ldata);
+		add_echo_byte(c, ldata);
+	}
+}
+
+/**
+ * finish_erasing	-	complete erase
+ * @ldata: n_tty data
+ */
+static inline void finish_erasing(struct n_tty_data *ldata)
+{
+	if (ldata->erasing) {
+		echo_char_raw('/', ldata);
+		ldata->erasing = 0;
+	}
+}
+
+/**
+ * eraser		-	handle erase function
+ * @c: character input
+ * @tty: terminal device
+ *
+ * Perform erase and necessary output when an erase character is present in the
+ * stream from the driver layer. Handles the complexities of UTF-8 multibyte
+ * symbols.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive %termios_rwsem
+ */
+static void eraser(u8 c, const struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	enum { ERASE, WERASE, KILL } kill_type;
+	size_t head;
+	size_t cnt;
+	int seen_alnums;
+
+	if (ldata->read_head == ldata->canon_head) {
+		/* process_output('\a', tty); */ /* what do you think? */
+		return;
+	}
+	if (c == ERASE_CHAR(tty))
+		kill_type = ERASE;
+	else if (c == WERASE_CHAR(tty))
+		kill_type = WERASE;
+	else {
+		if (!L_ECHO(tty)) {
+			ldata->read_head = ldata->canon_head;
+			return;
+		}
+		if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
+			ldata->read_head = ldata->canon_head;
+			finish_erasing(ldata);
+			echo_char(KILL_CHAR(tty), tty);
+			/* Add a newline if ECHOK is on and ECHOKE is off. */
+			if (L_ECHOK(tty))
+				echo_char_raw('\n', ldata);
+			return;
+		}
+		kill_type = KILL;
+	}
+
+	seen_alnums = 0;
+	while (MASK(ldata->read_head) != MASK(ldata->canon_head)) {
+		head = ldata->read_head;
+
+		/* erase a single possibly multibyte character */
+		do {
+			head--;
+			c = read_buf(ldata, head);
+		} while (is_continuation(c, tty) &&
+			 MASK(head) != MASK(ldata->canon_head));
+
+		/* do not partially erase */
+		if (is_continuation(c, tty))
+			break;
+
+		if (kill_type == WERASE) {
+			/* Equivalent to BSD's ALTWERASE. */
+			if (isalnum(c) || c == '_')
+				seen_alnums++;
+			else if (seen_alnums)
+				break;
+		}
+		cnt = ldata->read_head - head;
+		ldata->read_head = head;
+		if (L_ECHO(tty)) {
+			if (L_ECHOPRT(tty)) {
+				if (!ldata->erasing) {
+					echo_char_raw('\\', ldata);
+					ldata->erasing = 1;
+				}
+				/* if cnt > 1, output a multi-byte character */
+				echo_char(c, tty);
+				while (--cnt > 0) {
+					head++;
+					echo_char_raw(read_buf(ldata, head), ldata);
+					echo_move_back_col(ldata);
+				}
+			} else if (kill_type == ERASE && !L_ECHOE(tty)) {
+				echo_char(ERASE_CHAR(tty), tty);
+			} else if (c == '\t') {
+				unsigned int num_chars = 0;
+				int after_tab = 0;
+				size_t tail = ldata->read_head;
+
+				/*
+				 * Count the columns used for characters
+				 * since the start of input or after a
+				 * previous tab.
+				 * This info is used to go back the correct
+				 * number of columns.
+				 */
+				while (MASK(tail) != MASK(ldata->canon_head)) {
+					tail--;
+					c = read_buf(ldata, tail);
+					if (c == '\t') {
+						after_tab = 1;
+						break;
+					} else if (iscntrl(c)) {
+						if (L_ECHOCTL(tty))
+							num_chars += 2;
+					} else if (!is_continuation(c, tty)) {
+						num_chars++;
+					}
+				}
+				echo_erase_tab(num_chars, after_tab, ldata);
+			} else {
+				if (iscntrl(c) && L_ECHOCTL(tty)) {
+					echo_char_raw('\b', ldata);
+					echo_char_raw(' ', ldata);
+					echo_char_raw('\b', ldata);
+				}
+				if (!iscntrl(c) || L_ECHOCTL(tty)) {
+					echo_char_raw('\b', ldata);
+					echo_char_raw(' ', ldata);
+					echo_char_raw('\b', ldata);
+				}
+			}
+		}
+		if (kill_type == ERASE)
+			break;
+	}
+	if (ldata->read_head == ldata->canon_head && L_ECHO(tty))
+		finish_erasing(ldata);
+}
+
+
+static void __isig(int sig, struct tty_struct *tty)
+{
+	struct pid *tty_pgrp = tty_get_pgrp(tty);
+	if (tty_pgrp) {
+		kill_pgrp(tty_pgrp, sig, 1);
+		put_pid(tty_pgrp);
+	}
+}
+
+/**
+ * isig			-	handle the ISIG optio
+ * @sig: signal
+ * @tty: terminal
+ *
+ * Called when a signal is being sent due to terminal input. Called from the
+ * &tty_driver.receive_buf() path, so serialized.
+ *
+ * Performs input and output flush if !NOFLSH. In this context, the echo
+ * buffer is 'output'. The signal is processed first to alert any current
+ * readers or writers to discontinue and exit their i/o loops.
+ *
+ * Locking: %ctrl.lock
+ */
+static void isig(int sig, struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (L_NOFLSH(tty)) {
+		/* signal only */
+		__isig(sig, tty);
+
+	} else { /* signal and flush */
+		up_read(&tty->termios_rwsem);
+		down_write(&tty->termios_rwsem);
+
+		__isig(sig, tty);
+
+		/* clear echo buffer */
+		mutex_lock(&ldata->output_lock);
+		ldata->echo_head = ldata->echo_tail = 0;
+		ldata->echo_mark = ldata->echo_commit = 0;
+		mutex_unlock(&ldata->output_lock);
+
+		/* clear output buffer */
+		tty_driver_flush_buffer(tty);
+
+		/* clear input buffer */
+		reset_buffer_flags(tty->disc_data);
+
+		/* notify pty master of flush */
+		if (tty->link)
+			n_tty_packet_mode_flush(tty);
+
+		up_write(&tty->termios_rwsem);
+		down_read(&tty->termios_rwsem);
+	}
+}
+
+/**
+ * n_tty_receive_break	-	handle break
+ * @tty: terminal
+ *
+ * An RS232 break event has been hit in the incoming bitstream. This can cause
+ * a variety of events depending upon the termios settings.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive termios_rwsem
+ *
+ * Note: may get exclusive %termios_rwsem if flushing input buffer
+ */
+static void n_tty_receive_break(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (I_IGNBRK(tty))
+		return;
+	if (I_BRKINT(tty)) {
+		isig(SIGINT, tty);
+		return;
+	}
+	if (I_PARMRK(tty)) {
+		put_tty_queue('\377', ldata);
+		put_tty_queue('\0', ldata);
+	}
+	put_tty_queue('\0', ldata);
+}
+
+/**
+ * n_tty_receive_overrun	-	handle overrun reporting
+ * @tty: terminal
+ *
+ * Data arrived faster than we could process it. While the tty driver has
+ * flagged this the bits that were missed are gone forever.
+ *
+ * Called from the receive_buf path so single threaded. Does not need locking
+ * as num_overrun and overrun_time are function private.
+ */
+static void n_tty_receive_overrun(const struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	ldata->num_overrun++;
+	if (time_is_before_jiffies(ldata->overrun_time + HZ)) {
+		tty_warn(tty, "%u input overrun(s)\n", ldata->num_overrun);
+		ldata->overrun_time = jiffies;
+		ldata->num_overrun = 0;
+	}
+}
+
+/**
+ * n_tty_receive_parity_error	-	error notifier
+ * @tty: terminal device
+ * @c: character
+ *
+ * Process a parity error and queue the right data to indicate the error case
+ * if necessary.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ * 	caller holds non-exclusive %termios_rwsem
+ */
+static void n_tty_receive_parity_error(const struct tty_struct *tty,
+				       u8 c)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (I_INPCK(tty)) {
+		if (I_IGNPAR(tty))
+			return;
+		if (I_PARMRK(tty)) {
+			put_tty_queue('\377', ldata);
+			put_tty_queue('\0', ldata);
+			put_tty_queue(c, ldata);
+		} else
+			put_tty_queue('\0', ldata);
+	} else
+		put_tty_queue(c, ldata);
+}
+
+static void
+n_tty_receive_signal_char(struct tty_struct *tty, int signal, u8 c)
+{
+	isig(signal, tty);
+	if (I_IXON(tty))
+		start_tty(tty);
+	if (L_ECHO(tty)) {
+		echo_char(c, tty);
+		commit_echoes(tty);
+	} else
+		process_echoes(tty);
+}
+
+static bool n_tty_is_char_flow_ctrl(struct tty_struct *tty, u8 c)
+{
+	return c == START_CHAR(tty) || c == STOP_CHAR(tty);
+}
+
+/**
+ * n_tty_receive_char_flow_ctrl - receive flow control chars
+ * @tty: terminal device
+ * @c: character
+ * @lookahead_done: lookahead has processed this character already
+ *
+ * Receive and process flow control character actions.
+ *
+ * In case lookahead for flow control chars already handled the character in
+ * advance to the normal receive, the actions are skipped during normal
+ * receive.
+ *
+ * Returns true if @c is consumed as flow-control character, the character
+ * must not be treated as normal character.
+ */
+static bool n_tty_receive_char_flow_ctrl(struct tty_struct *tty, u8 c,
+					 bool lookahead_done)
+{
+	if (!n_tty_is_char_flow_ctrl(tty, c))
+		return false;
+
+	if (lookahead_done)
+		return true;
+
+	if (c == START_CHAR(tty)) {
+		start_tty(tty);
+		process_echoes(tty);
+		return true;
+	}
+
+	/* STOP_CHAR */
+	stop_tty(tty);
+	return true;
+}
+
+static void n_tty_receive_handle_newline(struct tty_struct *tty, u8 c)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	set_bit(MASK(ldata->read_head), ldata->read_flags);
+	put_tty_queue(c, ldata);
+	smp_store_release(&ldata->canon_head, ldata->read_head);
+	kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+	wake_up_interruptible_poll(&tty->read_wait, EPOLLIN | EPOLLRDNORM);
+}
+
+static bool n_tty_receive_char_canon(struct tty_struct *tty, u8 c)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
+	    (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
+		eraser(c, tty);
+		commit_echoes(tty);
+
+		return true;
+	}
+
+	if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
+		ldata->lnext = 1;
+		if (L_ECHO(tty)) {
+			finish_erasing(ldata);
+			if (L_ECHOCTL(tty)) {
+				echo_char_raw('^', ldata);
+				echo_char_raw('\b', ldata);
+				commit_echoes(tty);
+			}
+		}
+
+		return true;
+	}
+
+	if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) {
+		size_t tail = ldata->canon_head;
+
+		finish_erasing(ldata);
+		echo_char(c, tty);
+		echo_char_raw('\n', ldata);
+		while (MASK(tail) != MASK(ldata->read_head)) {
+			echo_char(read_buf(ldata, tail), tty);
+			tail++;
+		}
+		commit_echoes(tty);
+
+		return true;
+	}
+
+	if (c == '\n') {
+		if (L_ECHO(tty) || L_ECHONL(tty)) {
+			echo_char_raw('\n', ldata);
+			commit_echoes(tty);
+		}
+		n_tty_receive_handle_newline(tty, c);
+
+		return true;
+	}
+
+	if (c == EOF_CHAR(tty)) {
+		c = __DISABLED_CHAR;
+		n_tty_receive_handle_newline(tty, c);
+
+		return true;
+	}
+
+	if ((c == EOL_CHAR(tty)) ||
+	    (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
+		/*
+		 * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
+		 */
+		if (L_ECHO(tty)) {
+			/* Record the column of first canon char. */
+			if (ldata->canon_head == ldata->read_head)
+				echo_set_canon_col(ldata);
+			echo_char(c, tty);
+			commit_echoes(tty);
+		}
+		/*
+		 * XXX does PARMRK doubling happen for
+		 * EOL_CHAR and EOL2_CHAR?
+		 */
+		if (c == '\377' && I_PARMRK(tty))
+			put_tty_queue(c, ldata);
+
+		n_tty_receive_handle_newline(tty, c);
+
+		return true;
+	}
+
+	return false;
+}
+
+static void n_tty_receive_char_special(struct tty_struct *tty, u8 c,
+				       bool lookahead_done)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (I_IXON(tty) && n_tty_receive_char_flow_ctrl(tty, c, lookahead_done))
+		return;
+
+	if (L_ISIG(tty)) {
+		if (c == INTR_CHAR(tty)) {
+			n_tty_receive_signal_char(tty, SIGINT, c);
+			return;
+		} else if (c == QUIT_CHAR(tty)) {
+			n_tty_receive_signal_char(tty, SIGQUIT, c);
+			return;
+		} else if (c == SUSP_CHAR(tty)) {
+			n_tty_receive_signal_char(tty, SIGTSTP, c);
+			return;
+		}
+	}
+
+	if (tty->flow.stopped && !tty->flow.tco_stopped && I_IXON(tty) && I_IXANY(tty)) {
+		start_tty(tty);
+		process_echoes(tty);
+	}
+
+	if (c == '\r') {
+		if (I_IGNCR(tty))
+			return;
+		if (I_ICRNL(tty))
+			c = '\n';
+	} else if (c == '\n' && I_INLCR(tty))
+		c = '\r';
+
+	if (ldata->icanon && n_tty_receive_char_canon(tty, c))
+		return;
+
+	if (L_ECHO(tty)) {
+		finish_erasing(ldata);
+		if (c == '\n')
+			echo_char_raw('\n', ldata);
+		else {
+			/* Record the column of first canon char. */
+			if (ldata->canon_head == ldata->read_head)
+				echo_set_canon_col(ldata);
+			echo_char(c, tty);
+		}
+		commit_echoes(tty);
+	}
+
+	/* PARMRK doubling check */
+	if (c == '\377' && I_PARMRK(tty))
+		put_tty_queue(c, ldata);
+
+	put_tty_queue(c, ldata);
+}
+
+/**
+ * n_tty_receive_char	-	perform processing
+ * @tty: terminal device
+ * @c: character
+ *
+ * Process an individual character of input received from the driver.  This is
+ * serialized with respect to itself by the rules for the driver above.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive %termios_rwsem
+ *	publishes canon_head if canonical mode is active
+ */
+static void n_tty_receive_char(struct tty_struct *tty, u8 c)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (tty->flow.stopped && !tty->flow.tco_stopped && I_IXON(tty) && I_IXANY(tty)) {
+		start_tty(tty);
+		process_echoes(tty);
+	}
+	if (L_ECHO(tty)) {
+		finish_erasing(ldata);
+		/* Record the column of first canon char. */
+		if (ldata->canon_head == ldata->read_head)
+			echo_set_canon_col(ldata);
+		echo_char(c, tty);
+		commit_echoes(tty);
+	}
+	/* PARMRK doubling check */
+	if (c == '\377' && I_PARMRK(tty))
+		put_tty_queue(c, ldata);
+	put_tty_queue(c, ldata);
+}
+
+static void n_tty_receive_char_closing(struct tty_struct *tty, u8 c,
+				       bool lookahead_done)
+{
+	if (I_ISTRIP(tty))
+		c &= 0x7f;
+	if (I_IUCLC(tty) && L_IEXTEN(tty))
+		c = tolower(c);
+
+	if (I_IXON(tty)) {
+		if (!n_tty_receive_char_flow_ctrl(tty, c, lookahead_done) &&
+		    tty->flow.stopped && !tty->flow.tco_stopped && I_IXANY(tty) &&
+		    c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) &&
+		    c != SUSP_CHAR(tty)) {
+			start_tty(tty);
+			process_echoes(tty);
+		}
+	}
+}
+
+static void
+n_tty_receive_char_flagged(struct tty_struct *tty, u8 c, u8 flag)
+{
+	switch (flag) {
+	case TTY_BREAK:
+		n_tty_receive_break(tty);
+		break;
+	case TTY_PARITY:
+	case TTY_FRAME:
+		n_tty_receive_parity_error(tty, c);
+		break;
+	case TTY_OVERRUN:
+		n_tty_receive_overrun(tty);
+		break;
+	default:
+		tty_err(tty, "unknown flag %u\n", flag);
+		break;
+	}
+}
+
+static void
+n_tty_receive_char_lnext(struct tty_struct *tty, u8 c, u8 flag)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	ldata->lnext = 0;
+	if (likely(flag == TTY_NORMAL)) {
+		if (I_ISTRIP(tty))
+			c &= 0x7f;
+		if (I_IUCLC(tty) && L_IEXTEN(tty))
+			c = tolower(c);
+		n_tty_receive_char(tty, c);
+	} else
+		n_tty_receive_char_flagged(tty, c, flag);
+}
+
+/* Caller must ensure count > 0 */
+static void n_tty_lookahead_flow_ctrl(struct tty_struct *tty, const u8 *cp,
+				      const u8 *fp, size_t count)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	u8 flag = TTY_NORMAL;
+
+	ldata->lookahead_count += count;
+
+	if (!I_IXON(tty))
+		return;
+
+	while (count--) {
+		if (fp)
+			flag = *fp++;
+		if (likely(flag == TTY_NORMAL))
+			n_tty_receive_char_flow_ctrl(tty, *cp, false);
+		cp++;
+	}
+}
+
+static void
+n_tty_receive_buf_real_raw(const struct tty_struct *tty, const u8 *cp,
+			   size_t count)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	/* handle buffer wrap-around by a loop */
+	for (unsigned int i = 0; i < 2; i++) {
+		size_t head = MASK(ldata->read_head);
+		size_t n = min(count, N_TTY_BUF_SIZE - head);
+
+		memcpy(read_buf_addr(ldata, head), cp, n);
+
+		ldata->read_head += n;
+		cp += n;
+		count -= n;
+	}
+}
+
+static void
+n_tty_receive_buf_raw(struct tty_struct *tty, const u8 *cp, const u8 *fp,
+		      size_t count)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	u8 flag = TTY_NORMAL;
+
+	while (count--) {
+		if (fp)
+			flag = *fp++;
+		if (likely(flag == TTY_NORMAL))
+			put_tty_queue(*cp++, ldata);
+		else
+			n_tty_receive_char_flagged(tty, *cp++, flag);
+	}
+}
+
+static void
+n_tty_receive_buf_closing(struct tty_struct *tty, const u8 *cp, const u8 *fp,
+			  size_t count, bool lookahead_done)
+{
+	u8 flag = TTY_NORMAL;
+
+	while (count--) {
+		if (fp)
+			flag = *fp++;
+		if (likely(flag == TTY_NORMAL))
+			n_tty_receive_char_closing(tty, *cp++, lookahead_done);
+	}
+}
+
+static void n_tty_receive_buf_standard(struct tty_struct *tty, const u8 *cp,
+				       const u8 *fp, size_t count,
+				       bool lookahead_done)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	u8 flag = TTY_NORMAL;
+
+	while (count--) {
+		u8 c = *cp++;
+
+		if (fp)
+			flag = *fp++;
+
+		if (ldata->lnext) {
+			n_tty_receive_char_lnext(tty, c, flag);
+			continue;
+		}
+
+		if (unlikely(flag != TTY_NORMAL)) {
+			n_tty_receive_char_flagged(tty, c, flag);
+			continue;
+		}
+
+		if (I_ISTRIP(tty))
+			c &= 0x7f;
+		if (I_IUCLC(tty) && L_IEXTEN(tty))
+			c = tolower(c);
+		if (L_EXTPROC(tty)) {
+			put_tty_queue(c, ldata);
+			continue;
+		}
+
+		if (test_bit(c, ldata->char_map))
+			n_tty_receive_char_special(tty, c, lookahead_done);
+		else
+			n_tty_receive_char(tty, c);
+	}
+}
+
+static void __receive_buf(struct tty_struct *tty, const u8 *cp, const u8 *fp,
+			  size_t count)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	bool preops = I_ISTRIP(tty) || (I_IUCLC(tty) && L_IEXTEN(tty));
+	size_t la_count = min(ldata->lookahead_count, count);
+
+	if (ldata->real_raw)
+		n_tty_receive_buf_real_raw(tty, cp, count);
+	else if (ldata->raw || (L_EXTPROC(tty) && !preops))
+		n_tty_receive_buf_raw(tty, cp, fp, count);
+	else if (tty->closing && !L_EXTPROC(tty)) {
+		if (la_count > 0)
+			n_tty_receive_buf_closing(tty, cp, fp, la_count, true);
+		if (count > la_count)
+			n_tty_receive_buf_closing(tty, cp, fp, count - la_count, false);
+	} else {
+		if (la_count > 0)
+			n_tty_receive_buf_standard(tty, cp, fp, la_count, true);
+		if (count > la_count)
+			n_tty_receive_buf_standard(tty, cp, fp, count - la_count, false);
+
+		flush_echoes(tty);
+		if (tty->ops->flush_chars)
+			tty->ops->flush_chars(tty);
+	}
+
+	ldata->lookahead_count -= la_count;
+
+	if (ldata->icanon && !L_EXTPROC(tty))
+		return;
+
+	/* publish read_head to consumer */
+	smp_store_release(&ldata->commit_head, ldata->read_head);
+
+	if (read_cnt(ldata)) {
+		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+		wake_up_interruptible_poll(&tty->read_wait, EPOLLIN | EPOLLRDNORM);
+	}
+}
+
+/**
+ * n_tty_receive_buf_common	-	process input
+ * @tty: device to receive input
+ * @cp: input chars
+ * @fp: flags for each char (if %NULL, all chars are %TTY_NORMAL)
+ * @count: number of input chars in @cp
+ * @flow: enable flow control
+ *
+ * Called by the terminal driver when a block of characters has been received.
+ * This function must be called from soft contexts not from interrupt context.
+ * The driver is responsible for making calls one at a time and in order (or
+ * using flush_to_ldisc()).
+ *
+ * Returns: the # of input chars from @cp which were processed.
+ *
+ * In canonical mode, the maximum line length is 4096 chars (including the line
+ * termination char); lines longer than 4096 chars are truncated. After 4095
+ * chars, input data is still processed but not stored. Overflow processing
+ * ensures the tty can always receive more input until at least one line can be
+ * read.
+ *
+ * In non-canonical mode, the read buffer will only accept 4095 chars; this
+ * provides the necessary space for a newline char if the input mode is
+ * switched to canonical.
+ *
+ * Note it is possible for the read buffer to _contain_ 4096 chars in
+ * non-canonical mode: the read buffer could already contain the maximum canon
+ * line of 4096 chars when the mode is switched to non-canonical.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ *	claims non-exclusive %termios_rwsem
+ *	publishes commit_head or canon_head
+ */
+static size_t
+n_tty_receive_buf_common(struct tty_struct *tty, const u8 *cp, const u8 *fp,
+			 size_t count, bool flow)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	size_t n, rcvd = 0;
+	int room, overflow;
+
+	down_read(&tty->termios_rwsem);
+
+	do {
+		/*
+		 * When PARMRK is set, each input char may take up to 3 chars
+		 * in the read buf; reduce the buffer space avail by 3x
+		 *
+		 * If we are doing input canonicalization, and there are no
+		 * pending newlines, let characters through without limit, so
+		 * that erase characters will be handled.  Other excess
+		 * characters will be beeped.
+		 *
+		 * paired with store in *_copy_from_read_buf() -- guarantees
+		 * the consumer has loaded the data in read_buf up to the new
+		 * read_tail (so this producer will not overwrite unread data)
+		 */
+		size_t tail = smp_load_acquire(&ldata->read_tail);
+
+		room = N_TTY_BUF_SIZE - (ldata->read_head - tail);
+		if (I_PARMRK(tty))
+			room = DIV_ROUND_UP(room, 3);
+		room--;
+		if (room <= 0) {
+			overflow = ldata->icanon && ldata->canon_head == tail;
+			if (overflow && room < 0)
+				ldata->read_head--;
+			room = overflow;
+			WRITE_ONCE(ldata->no_room, flow && !room);
+		} else
+			overflow = 0;
+
+		n = min_t(size_t, count, room);
+		if (!n)
+			break;
+
+		/* ignore parity errors if handling overflow */
+		if (!overflow || !fp || *fp != TTY_PARITY)
+			__receive_buf(tty, cp, fp, n);
+
+		cp += n;
+		if (fp)
+			fp += n;
+		count -= n;
+		rcvd += n;
+	} while (!test_bit(TTY_LDISC_CHANGING, &tty->flags));
+
+	tty->receive_room = room;
+
+	/* Unthrottle if handling overflow on pty */
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
+		if (overflow) {
+			tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
+			tty_unthrottle_safe(tty);
+			__tty_set_flow_change(tty, 0);
+		}
+	} else
+		n_tty_check_throttle(tty);
+
+	if (unlikely(ldata->no_room)) {
+		/*
+		 * Barrier here is to ensure to read the latest read_tail in
+		 * chars_in_buffer() and to make sure that read_tail is not loaded
+		 * before ldata->no_room is set.
+		 */
+		smp_mb();
+		if (!chars_in_buffer(tty))
+			n_tty_kick_worker(tty);
+	}
+
+	up_read(&tty->termios_rwsem);
+
+	return rcvd;
+}
+
+static void n_tty_receive_buf(struct tty_struct *tty, const u8 *cp,
+			      const u8 *fp, size_t count)
+{
+	n_tty_receive_buf_common(tty, cp, fp, count, false);
+}
+
+static size_t n_tty_receive_buf2(struct tty_struct *tty, const u8 *cp,
+				 const u8 *fp, size_t count)
+{
+	return n_tty_receive_buf_common(tty, cp, fp, count, true);
+}
+
+/**
+ * n_tty_set_termios	-	termios data changed
+ * @tty: terminal
+ * @old: previous data
+ *
+ * Called by the tty layer when the user changes termios flags so that the line
+ * discipline can plan ahead. This function cannot sleep and is protected from
+ * re-entry by the tty layer. The user is guaranteed that this function will
+ * not be re-entered or in progress when the ldisc is closed.
+ *
+ * Locking: Caller holds @tty->termios_rwsem
+ */
+static void n_tty_set_termios(struct tty_struct *tty, const struct ktermios *old)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (!old || (old->c_lflag ^ tty->termios.c_lflag) & (ICANON | EXTPROC)) {
+		bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
+		ldata->line_start = ldata->read_tail;
+		if (!L_ICANON(tty) || !read_cnt(ldata)) {
+			ldata->canon_head = ldata->read_tail;
+			ldata->push = 0;
+		} else {
+			set_bit(MASK(ldata->read_head - 1), ldata->read_flags);
+			ldata->canon_head = ldata->read_head;
+			ldata->push = 1;
+		}
+		ldata->commit_head = ldata->read_head;
+		ldata->erasing = 0;
+		ldata->lnext = 0;
+	}
+
+	ldata->icanon = (L_ICANON(tty) != 0);
+
+	if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
+	    I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
+	    I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
+	    I_PARMRK(tty)) {
+		bitmap_zero(ldata->char_map, 256);
+
+		if (I_IGNCR(tty) || I_ICRNL(tty))
+			set_bit('\r', ldata->char_map);
+		if (I_INLCR(tty))
+			set_bit('\n', ldata->char_map);
+
+		if (L_ICANON(tty)) {
+			set_bit(ERASE_CHAR(tty), ldata->char_map);
+			set_bit(KILL_CHAR(tty), ldata->char_map);
+			set_bit(EOF_CHAR(tty), ldata->char_map);
+			set_bit('\n', ldata->char_map);
+			set_bit(EOL_CHAR(tty), ldata->char_map);
+			if (L_IEXTEN(tty)) {
+				set_bit(WERASE_CHAR(tty), ldata->char_map);
+				set_bit(LNEXT_CHAR(tty), ldata->char_map);
+				set_bit(EOL2_CHAR(tty), ldata->char_map);
+				if (L_ECHO(tty))
+					set_bit(REPRINT_CHAR(tty),
+						ldata->char_map);
+			}
+		}
+		if (I_IXON(tty)) {
+			set_bit(START_CHAR(tty), ldata->char_map);
+			set_bit(STOP_CHAR(tty), ldata->char_map);
+		}
+		if (L_ISIG(tty)) {
+			set_bit(INTR_CHAR(tty), ldata->char_map);
+			set_bit(QUIT_CHAR(tty), ldata->char_map);
+			set_bit(SUSP_CHAR(tty), ldata->char_map);
+		}
+		clear_bit(__DISABLED_CHAR, ldata->char_map);
+		ldata->raw = 0;
+		ldata->real_raw = 0;
+	} else {
+		ldata->raw = 1;
+		if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
+		    (I_IGNPAR(tty) || !I_INPCK(tty)) &&
+		    (tty->driver->flags & TTY_DRIVER_REAL_RAW))
+			ldata->real_raw = 1;
+		else
+			ldata->real_raw = 0;
+	}
+	/*
+	 * Fix tty hang when I_IXON(tty) is cleared, but the tty
+	 * been stopped by STOP_CHAR(tty) before it.
+	 */
+	if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow.tco_stopped) {
+		start_tty(tty);
+		process_echoes(tty);
+	}
+
+	/* The termios change make the tty ready for I/O */
+	wake_up_interruptible(&tty->write_wait);
+	wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ * n_tty_close		-	close the ldisc for this tty
+ * @tty: device
+ *
+ * Called from the terminal layer when this line discipline is being shut down,
+ * either because of a close or becsuse of a discipline change. The function
+ * will not be called while other ldisc methods are in progress.
+ */
+static void n_tty_close(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+
+	if (tty->link)
+		n_tty_packet_mode_flush(tty);
+
+	down_write(&tty->termios_rwsem);
+	vfree(ldata);
+	tty->disc_data = NULL;
+	up_write(&tty->termios_rwsem);
+}
+
+/**
+ * n_tty_open		-	open an ldisc
+ * @tty: terminal to open
+ *
+ * Called when this line discipline is being attached to the terminal device.
+ * Can sleep. Called serialized so that no other events will occur in parallel.
+ * No further open will occur until a close.
+ */
+static int n_tty_open(struct tty_struct *tty)
+{
+	struct n_tty_data *ldata;
+
+	/* Currently a malloc failure here can panic */
+	ldata = vzalloc(sizeof(*ldata));
+	if (!ldata)
+		return -ENOMEM;
+
+	ldata->overrun_time = jiffies;
+	mutex_init(&ldata->atomic_read_lock);
+	mutex_init(&ldata->output_lock);
+
+	tty->disc_data = ldata;
+	tty->closing = 0;
+	/* indicate buffer work may resume */
+	clear_bit(TTY_LDISC_HALTED, &tty->flags);
+	n_tty_set_termios(tty, NULL);
+	tty_unthrottle(tty);
+	return 0;
+}
+
+static inline int input_available_p(const struct tty_struct *tty, int poll)
+{
+	const struct n_tty_data *ldata = tty->disc_data;
+	int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1;
+
+	if (ldata->icanon && !L_EXTPROC(tty))
+		return ldata->canon_head != ldata->read_tail;
+	else
+		return ldata->commit_head - ldata->read_tail >= amt;
+}
+
+/**
+ * copy_from_read_buf	-	copy read data directly
+ * @tty: terminal device
+ * @kbp: data
+ * @nr: size of data
+ *
+ * Helper function to speed up n_tty_read(). It is only called when %ICANON is
+ * off; it copies characters straight from the tty queue.
+ *
+ * Returns: true if it successfully copied data, but there is still more data
+ * to be had.
+ *
+ * Locking:
+ *  * called under the @ldata->atomic_read_lock sem
+ *  * n_tty_read()/consumer path:
+ *		caller holds non-exclusive %termios_rwsem;
+ *		read_tail published
+ */
+static bool copy_from_read_buf(const struct tty_struct *tty, u8 **kbp,
+			       size_t *nr)
+
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	size_t n;
+	bool is_eof;
+	size_t head = smp_load_acquire(&ldata->commit_head);
+	size_t tail = MASK(ldata->read_tail);
+
+	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
+	n = min(*nr, n);
+	if (n) {
+		u8 *from = read_buf_addr(ldata, tail);
+		memcpy(*kbp, from, n);
+		is_eof = n == 1 && *from == EOF_CHAR(tty);
+		tty_audit_add_data(tty, from, n);
+		zero_buffer(tty, from, n);
+		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
+		/* Turn single EOF into zero-length read */
+		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
+		    (head == ldata->read_tail))
+			return false;
+		*kbp += n;
+		*nr -= n;
+
+		/* If we have more to copy, let the caller know */
+		return head != ldata->read_tail;
+	}
+	return false;
+}
+
+/**
+ * canon_copy_from_read_buf	-	copy read data in canonical mode
+ * @tty: terminal device
+ * @kbp: data
+ * @nr: size of data
+ *
+ * Helper function for n_tty_read(). It is only called when %ICANON is on; it
+ * copies one line of input up to and including the line-delimiting character
+ * into the result buffer.
+ *
+ * Note: When termios is changed from non-canonical to canonical mode and the
+ * read buffer contains data, n_tty_set_termios() simulates an EOF push (as if
+ * C-d were input) _without_ the %DISABLED_CHAR in the buffer. This causes data
+ * already processed as input to be immediately available as input although a
+ * newline has not been received.
+ *
+ * Locking:
+ *  * called under the %atomic_read_lock mutex
+ *  * n_tty_read()/consumer path:
+ *	caller holds non-exclusive %termios_rwsem;
+ *	read_tail published
+ */
+static bool canon_copy_from_read_buf(const struct tty_struct *tty, u8 **kbp,
+				     size_t *nr)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	size_t n, size, more, c;
+	size_t eol;
+	size_t tail, canon_head;
+	int found = 0;
+
+	/* N.B. avoid overrun if nr == 0 */
+	if (!*nr)
+		return false;
+
+	canon_head = smp_load_acquire(&ldata->canon_head);
+	n = min(*nr, canon_head - ldata->read_tail);
+
+	tail = MASK(ldata->read_tail);
+	size = min_t(size_t, tail + n, N_TTY_BUF_SIZE);
+
+	n_tty_trace("%s: nr:%zu tail:%zu n:%zu size:%zu\n",
+		    __func__, *nr, tail, n, size);
+
+	eol = find_next_bit(ldata->read_flags, size, tail);
+	more = n - (size - tail);
+	if (eol == N_TTY_BUF_SIZE && more) {
+		/* scan wrapped without finding set bit */
+		eol = find_first_bit(ldata->read_flags, more);
+		found = eol != more;
+	} else
+		found = eol != size;
+
+	n = eol - tail;
+	if (n > N_TTY_BUF_SIZE)
+		n += N_TTY_BUF_SIZE;
+	c = n + found;
+
+	if (!found || read_buf(ldata, eol) != __DISABLED_CHAR)
+		n = c;
+
+	n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n",
+		    __func__, eol, found, n, c, tail, more);
+
+	tty_copy(tty, *kbp, tail, n);
+	*kbp += n;
+	*nr -= n;
+
+	if (found)
+		clear_bit(eol, ldata->read_flags);
+	smp_store_release(&ldata->read_tail, ldata->read_tail + c);
+
+	if (found) {
+		if (!ldata->push)
+			ldata->line_start = ldata->read_tail;
+		else
+			ldata->push = 0;
+		tty_audit_push();
+		return false;
+	}
+
+	/* No EOL found - do a continuation retry if there is more data */
+	return ldata->read_tail != canon_head;
+}
+
+/*
+ * If we finished a read at the exact location of an
+ * EOF (special EOL character that's a __DISABLED_CHAR)
+ * in the stream, silently eat the EOF.
+ */
+static void canon_skip_eof(struct n_tty_data *ldata)
+{
+	size_t tail, canon_head;
+
+	canon_head = smp_load_acquire(&ldata->canon_head);
+	tail = ldata->read_tail;
+
+	// No data?
+	if (tail == canon_head)
+		return;
+
+	// See if the tail position is EOF in the circular buffer
+	tail &= (N_TTY_BUF_SIZE - 1);
+	if (!test_bit(tail, ldata->read_flags))
+		return;
+	if (read_buf(ldata, tail) != __DISABLED_CHAR)
+		return;
+
+	// Clear the EOL bit, skip the EOF char.
+	clear_bit(tail, ldata->read_flags);
+	smp_store_release(&ldata->read_tail, ldata->read_tail + 1);
+}
+
+/**
+ * job_control		-	check job control
+ * @tty: tty
+ * @file: file handle
+ *
+ * Perform job control management checks on this @file/@tty descriptor and if
+ * appropriate send any needed signals and return a negative error code if
+ * action should be taken.
+ *
+ * Locking:
+ *  * redirected write test is safe
+ *  * current->signal->tty check is safe
+ *  * ctrl.lock to safely reference @tty->ctrl.pgrp
+ */
+static int job_control(struct tty_struct *tty, struct file *file)
+{
+	/* Job control check -- must be done at start and after
+	   every sleep (POSIX.1 7.1.1.4). */
+	/* NOTE: not yet done after every sleep pending a thorough
+	   check of the logic of this change. -- jlc */
+	/* don't stop on /dev/console */
+	if (file->f_op->write_iter == redirected_tty_write)
+		return 0;
+
+	return __tty_check_change(tty, SIGTTIN);
+}
+
+
+/**
+ * n_tty_read		-	read function for tty
+ * @tty: tty device
+ * @file: file object
+ * @kbuf: kernelspace buffer pointer
+ * @nr: size of I/O
+ * @cookie: if non-%NULL, this is a continuation read
+ * @offset: where to continue reading from (unused in n_tty)
+ *
+ * Perform reads for the line discipline. We are guaranteed that the line
+ * discipline will not be closed under us but we may get multiple parallel
+ * readers and must handle this ourselves. We may also get a hangup. Always
+ * called in user context, may sleep.
+ *
+ * This code must be sure never to sleep through a hangup.
+ *
+ * Locking: n_tty_read()/consumer path:
+ *	claims non-exclusive termios_rwsem;
+ *	publishes read_tail
+ */
+static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
+			  size_t nr, void **cookie, unsigned long offset)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	u8 *kb = kbuf;
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	int c;
+	int minimum, time;
+	ssize_t retval = 0;
+	long timeout;
+	bool packet;
+	size_t old_tail;
+
+	/*
+	 * Is this a continuation of a read started earler?
+	 *
+	 * If so, we still hold the atomic_read_lock and the
+	 * termios_rwsem, and can just continue to copy data.
+	 */
+	if (*cookie) {
+		if (ldata->icanon && !L_EXTPROC(tty)) {
+			/*
+			 * If we have filled the user buffer, see
+			 * if we should skip an EOF character before
+			 * releasing the lock and returning done.
+			 */
+			if (!nr)
+				canon_skip_eof(ldata);
+			else if (canon_copy_from_read_buf(tty, &kb, &nr))
+				return kb - kbuf;
+		} else {
+			if (copy_from_read_buf(tty, &kb, &nr))
+				return kb - kbuf;
+		}
+
+		/* No more data - release locks and stop retries */
+		n_tty_kick_worker(tty);
+		n_tty_check_unthrottle(tty);
+		up_read(&tty->termios_rwsem);
+		mutex_unlock(&ldata->atomic_read_lock);
+		*cookie = NULL;
+		return kb - kbuf;
+	}
+
+	c = job_control(tty, file);
+	if (c < 0)
+		return c;
+
+	/*
+	 *	Internal serialization of reads.
+	 */
+	if (file->f_flags & O_NONBLOCK) {
+		if (!mutex_trylock(&ldata->atomic_read_lock))
+			return -EAGAIN;
+	} else {
+		if (mutex_lock_interruptible(&ldata->atomic_read_lock))
+			return -ERESTARTSYS;
+	}
+
+	down_read(&tty->termios_rwsem);
+
+	minimum = time = 0;
+	timeout = MAX_SCHEDULE_TIMEOUT;
+	if (!ldata->icanon) {
+		minimum = MIN_CHAR(tty);
+		if (minimum) {
+			time = (HZ / 10) * TIME_CHAR(tty);
+		} else {
+			timeout = (HZ / 10) * TIME_CHAR(tty);
+			minimum = 1;
+		}
+	}
+
+	packet = tty->ctrl.packet;
+	old_tail = ldata->read_tail;
+
+	add_wait_queue(&tty->read_wait, &wait);
+	while (nr) {
+		/* First test for status change. */
+		if (packet && tty->link->ctrl.pktstatus) {
+			u8 cs;
+			if (kb != kbuf)
+				break;
+			spin_lock_irq(&tty->link->ctrl.lock);
+			cs = tty->link->ctrl.pktstatus;
+			tty->link->ctrl.pktstatus = 0;
+			spin_unlock_irq(&tty->link->ctrl.lock);
+			*kb++ = cs;
+			nr--;
+			break;
+		}
+
+		if (!input_available_p(tty, 0)) {
+			up_read(&tty->termios_rwsem);
+			tty_buffer_flush_work(tty->port);
+			down_read(&tty->termios_rwsem);
+			if (!input_available_p(tty, 0)) {
+				if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+					retval = -EIO;
+					break;
+				}
+				if (tty_hung_up_p(file))
+					break;
+				/*
+				 * Abort readers for ttys which never actually
+				 * get hung up.  See __tty_hangup().
+				 */
+				if (test_bit(TTY_HUPPING, &tty->flags))
+					break;
+				if (!timeout)
+					break;
+				if (tty_io_nonblock(tty, file)) {
+					retval = -EAGAIN;
+					break;
+				}
+				if (signal_pending(current)) {
+					retval = -ERESTARTSYS;
+					break;
+				}
+				up_read(&tty->termios_rwsem);
+
+				timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
+						timeout);
+
+				down_read(&tty->termios_rwsem);
+				continue;
+			}
+		}
+
+		if (ldata->icanon && !L_EXTPROC(tty)) {
+			if (canon_copy_from_read_buf(tty, &kb, &nr))
+				goto more_to_be_read;
+		} else {
+			/* Deal with packet mode. */
+			if (packet && kb == kbuf) {
+				*kb++ = TIOCPKT_DATA;
+				nr--;
+			}
+
+			/*
+			 * Copy data, and if there is more to be had
+			 * and we have nothing more to wait for, then
+			 * let's mark us for retries.
+			 *
+			 * NOTE! We return here with both the termios_sem
+			 * and atomic_read_lock still held, the retries
+			 * will release them when done.
+			 */
+			if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum) {
+more_to_be_read:
+				remove_wait_queue(&tty->read_wait, &wait);
+				*cookie = cookie;
+				return kb - kbuf;
+			}
+		}
+
+		n_tty_check_unthrottle(tty);
+
+		if (kb - kbuf >= minimum)
+			break;
+		if (time)
+			timeout = time;
+	}
+	if (old_tail != ldata->read_tail) {
+		/*
+		 * Make sure no_room is not read in n_tty_kick_worker()
+		 * before setting ldata->read_tail in copy_from_read_buf().
+		 */
+		smp_mb();
+		n_tty_kick_worker(tty);
+	}
+	up_read(&tty->termios_rwsem);
+
+	remove_wait_queue(&tty->read_wait, &wait);
+	mutex_unlock(&ldata->atomic_read_lock);
+
+	if (kb - kbuf)
+		retval = kb - kbuf;
+
+	return retval;
+}
+
+/**
+ * n_tty_write		-	write function for tty
+ * @tty: tty device
+ * @file: file object
+ * @buf: userspace buffer pointer
+ * @nr: size of I/O
+ *
+ * Write function of the terminal device. This is serialized with respect to
+ * other write callers but not to termios changes, reads and other such events.
+ * Since the receive code will echo characters, thus calling driver write
+ * methods, the %output_lock is used in the output processing functions called
+ * here as well as in the echo processing function to protect the column state
+ * and space left in the buffer.
+ *
+ * This code must be sure never to sleep through a hangup.
+ *
+ * Locking: output_lock to protect column state and space left
+ *	 (note that the process_output*() functions take this lock themselves)
+ */
+
+static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
+			   const u8 *buf, size_t nr)
+{
+	const u8 *b = buf;
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	ssize_t num, retval = 0;
+
+	/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
+	if (L_TOSTOP(tty) && file->f_op->write_iter != redirected_tty_write) {
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+	}
+
+	down_read(&tty->termios_rwsem);
+
+	/* Write out any echoed characters that are still pending */
+	process_echoes(tty);
+
+	add_wait_queue(&tty->write_wait, &wait);
+	while (1) {
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+		if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
+			retval = -EIO;
+			break;
+		}
+		if (O_OPOST(tty)) {
+			while (nr > 0) {
+				num = process_output_block(tty, b, nr);
+				if (num < 0) {
+					if (num == -EAGAIN)
+						break;
+					retval = num;
+					goto break_out;
+				}
+				b += num;
+				nr -= num;
+				if (nr == 0)
+					break;
+				if (process_output(*b, tty) < 0)
+					break;
+				b++; nr--;
+			}
+			if (tty->ops->flush_chars)
+				tty->ops->flush_chars(tty);
+		} else {
+			struct n_tty_data *ldata = tty->disc_data;
+
+			while (nr > 0) {
+				mutex_lock(&ldata->output_lock);
+				num = tty->ops->write(tty, b, nr);
+				mutex_unlock(&ldata->output_lock);
+				if (num < 0) {
+					retval = num;
+					goto break_out;
+				}
+				if (!num)
+					break;
+				b += num;
+				nr -= num;
+			}
+		}
+		if (!nr)
+			break;
+		if (tty_io_nonblock(tty, file)) {
+			retval = -EAGAIN;
+			break;
+		}
+		up_read(&tty->termios_rwsem);
+
+		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+
+		down_read(&tty->termios_rwsem);
+	}
+break_out:
+	remove_wait_queue(&tty->write_wait, &wait);
+	if (nr && tty->fasync)
+		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	up_read(&tty->termios_rwsem);
+	return (b - buf) ? b - buf : retval;
+}
+
+/**
+ * n_tty_poll		-	poll method for N_TTY
+ * @tty: terminal device
+ * @file: file accessing it
+ * @wait: poll table
+ *
+ * Called when the line discipline is asked to poll() for data or for special
+ * events. This code is not serialized with respect to other events save
+ * open/close.
+ *
+ * This code must be sure never to sleep through a hangup.
+ *
+ * Locking: called without the kernel lock held -- fine.
+ */
+static __poll_t n_tty_poll(struct tty_struct *tty, struct file *file,
+							poll_table *wait)
+{
+	__poll_t mask = 0;
+
+	poll_wait(file, &tty->read_wait, wait);
+	poll_wait(file, &tty->write_wait, wait);
+	if (input_available_p(tty, 1))
+		mask |= EPOLLIN | EPOLLRDNORM;
+	else {
+		tty_buffer_flush_work(tty->port);
+		if (input_available_p(tty, 1))
+			mask |= EPOLLIN | EPOLLRDNORM;
+	}
+	if (tty->ctrl.packet && tty->link->ctrl.pktstatus)
+		mask |= EPOLLPRI | EPOLLIN | EPOLLRDNORM;
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		mask |= EPOLLHUP;
+	if (tty_hung_up_p(file))
+		mask |= EPOLLHUP;
+	if (tty->ops->write && !tty_is_writelocked(tty) &&
+			tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
+			tty_write_room(tty) > 0)
+		mask |= EPOLLOUT | EPOLLWRNORM;
+	return mask;
+}
+
+static unsigned long inq_canon(struct n_tty_data *ldata)
+{
+	size_t nr, head, tail;
+
+	if (ldata->canon_head == ldata->read_tail)
+		return 0;
+	head = ldata->canon_head;
+	tail = ldata->read_tail;
+	nr = head - tail;
+	/* Skip EOF-chars.. */
+	while (MASK(head) != MASK(tail)) {
+		if (test_bit(MASK(tail), ldata->read_flags) &&
+		    read_buf(ldata, tail) == __DISABLED_CHAR)
+			nr--;
+		tail++;
+	}
+	return nr;
+}
+
+static int n_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
+		       unsigned long arg)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	int retval;
+
+	switch (cmd) {
+	case TIOCOUTQ:
+		return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
+	case TIOCINQ:
+		down_write(&tty->termios_rwsem);
+		if (L_ICANON(tty) && !L_EXTPROC(tty))
+			retval = inq_canon(ldata);
+		else
+			retval = read_cnt(ldata);
+		up_write(&tty->termios_rwsem);
+		return put_user(retval, (unsigned int __user *) arg);
+	default:
+		return n_tty_ioctl_helper(tty, cmd, arg);
+	}
+}
+
+static struct tty_ldisc_ops n_tty_ops = {
+	.owner		 = THIS_MODULE,
+	.num		 = N_TTY,
+	.name            = "n_tty",
+	.open            = n_tty_open,
+	.close           = n_tty_close,
+	.flush_buffer    = n_tty_flush_buffer,
+	.read            = n_tty_read,
+	.write           = n_tty_write,
+	.ioctl           = n_tty_ioctl,
+	.set_termios     = n_tty_set_termios,
+	.poll            = n_tty_poll,
+	.receive_buf     = n_tty_receive_buf,
+	.write_wakeup    = n_tty_write_wakeup,
+	.receive_buf2	 = n_tty_receive_buf2,
+	.lookahead_buf	 = n_tty_lookahead_flow_ctrl,
+};
+
+/**
+ *	n_tty_inherit_ops	-	inherit N_TTY methods
+ *	@ops: struct tty_ldisc_ops where to save N_TTY methods
+ *
+ *	Enables a 'subclass' line discipline to 'inherit' N_TTY methods.
+ */
+
+void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
+{
+	*ops = n_tty_ops;
+	ops->owner = NULL;
+}
+EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
+
+void __init n_tty_init(void)
+{
+	tty_register_ldisc(&n_tty_ops);
+}
diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
new file mode 100644
index 000000000..02cd40147
--- /dev/null
+++ b/drivers/tty/nozomi.c
@@ -0,0 +1,1875 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ * nozomi.c  -- HSDPA driver Broadband Wireless Data Card - Globe Trotter
+ *
+ * Written by: Ulf Jakobsson,
+ *             Jan Åkerfeldt,
+ *             Stefan Thomasson,
+ *
+ * Maintained by: Paul Hardwick (p.hardwick@option.com)
+ *
+ * Patches:
+ *          Locking code changes for Vodafone by Sphere Systems Ltd,
+ *                              Andrew Bird (ajb@spheresystems.co.uk )
+ *                              & Phil Sanderson
+ *
+ * Source has been ported from an implementation made by Filip Aben @ Option
+ *
+ * --------------------------------------------------------------------------
+ *
+ * Copyright (c) 2005,2006 Option Wireless Sweden AB
+ * Copyright (c) 2006 Sphere Systems Ltd
+ * Copyright (c) 2006 Option Wireless n/v
+ * All rights Reserved.
+ *
+ * --------------------------------------------------------------------------
+ */
+
+/* Enable this to have a lot of debug printouts */
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/sched.h>
+#include <linux/serial.h>
+#include <linux/interrupt.h>
+#include <linux/kmod.h>
+#include <linux/init.h>
+#include <linux/kfifo.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <asm/byteorder.h>
+
+#include <linux/delay.h>
+
+/* Default debug printout level */
+#define NOZOMI_DEBUG_LEVEL 0x00
+static int debug = NOZOMI_DEBUG_LEVEL;
+module_param(debug, int, S_IRUGO | S_IWUSR);
+
+/*    Macros definitions */
+#define DBG_(lvl, fmt, args...)				\
+do {							\
+	if (lvl & debug)				\
+		pr_debug("[%d] %s(): " fmt "\n",	\
+			 __LINE__, __func__,  ##args);	\
+} while (0)
+
+#define DBG1(args...) DBG_(0x01, ##args)
+#define DBG2(args...) DBG_(0x02, ##args)
+#define DBG3(args...) DBG_(0x04, ##args)
+#define DBG4(args...) DBG_(0x08, ##args)
+
+/* TODO: rewrite to optimize macros... */
+
+#define TMP_BUF_MAX 256
+
+#define DUMP(buf__, len__)						\
+	do {								\
+		char tbuf[TMP_BUF_MAX] = {0};				\
+		if (len__ > 1) {					\
+			u32 data_len = min_t(u32, len__, TMP_BUF_MAX);	\
+			strscpy(tbuf, buf__, data_len);			\
+			if (tbuf[data_len - 2] == '\r')			\
+				tbuf[data_len - 2] = 'r';		\
+			DBG1("SENDING: '%s' (%d+n)", tbuf, len__);	\
+		} else {						\
+			DBG1("SENDING: '%s' (%d)", tbuf, len__);	\
+		}							\
+	} while (0)
+
+/*    Defines */
+#define NOZOMI_NAME		"nozomi"
+#define NOZOMI_NAME_TTY		"nozomi_tty"
+
+#define NTTY_TTY_MAXMINORS	256
+#define NTTY_FIFO_BUFFER_SIZE	8192
+
+/* Must be power of 2 */
+#define FIFO_BUFFER_SIZE_UL	8192
+
+/* Size of tmp send buffer to card */
+#define SEND_BUF_MAX		1024
+#define RECEIVE_BUF_MAX		4
+
+
+#define R_IIR			0x0000	/* Interrupt Identity Register */
+#define R_FCR			0x0000	/* Flow Control Register */
+#define R_IER			0x0004	/* Interrupt Enable Register */
+
+#define NOZOMI_CONFIG_MAGIC	0xEFEFFEFE
+#define TOGGLE_VALID		0x0000
+
+/* Definition of interrupt tokens */
+#define MDM_DL1			0x0001
+#define MDM_UL1			0x0002
+#define MDM_DL2			0x0004
+#define MDM_UL2			0x0008
+#define DIAG_DL1		0x0010
+#define DIAG_DL2		0x0020
+#define DIAG_UL			0x0040
+#define APP1_DL			0x0080
+#define APP1_UL			0x0100
+#define APP2_DL			0x0200
+#define APP2_UL			0x0400
+#define CTRL_DL			0x0800
+#define CTRL_UL			0x1000
+#define RESET			0x8000
+
+#define MDM_DL			(MDM_DL1  | MDM_DL2)
+#define MDM_UL			(MDM_UL1  | MDM_UL2)
+#define DIAG_DL			(DIAG_DL1 | DIAG_DL2)
+
+/* modem signal definition */
+#define CTRL_DSR		0x0001
+#define CTRL_DCD		0x0002
+#define CTRL_RI			0x0004
+#define CTRL_CTS		0x0008
+
+#define CTRL_DTR		0x0001
+#define CTRL_RTS		0x0002
+
+#define MAX_PORT		4
+#define NOZOMI_MAX_PORTS	5
+#define NOZOMI_MAX_CARDS	(NTTY_TTY_MAXMINORS / MAX_PORT)
+
+/*    Type definitions */
+
+/*
+ * There are two types of nozomi cards,
+ * one with 2048 memory and with 8192 memory
+ */
+enum card_type {
+	F32_2 = 2048,	/* 512 bytes downlink + uplink * 2 -> 2048 */
+	F32_8 = 8192,	/* 3072 bytes downl. + 1024 bytes uplink * 2 -> 8192 */
+};
+
+/* Initialization states a card can be in */
+enum card_state {
+	NOZOMI_STATE_UNKNOWN	= 0,
+	NOZOMI_STATE_ENABLED	= 1,	/* pci device enabled */
+	NOZOMI_STATE_ALLOCATED	= 2,	/* config setup done */
+	NOZOMI_STATE_READY	= 3,	/* flowcontrols received */
+};
+
+/* Two different toggle channels exist */
+enum channel_type {
+	CH_A = 0,
+	CH_B = 1,
+};
+
+/* Port definition for the card regarding flow control */
+enum ctrl_port_type {
+	CTRL_CMD	= 0,
+	CTRL_MDM	= 1,
+	CTRL_DIAG	= 2,
+	CTRL_APP1	= 3,
+	CTRL_APP2	= 4,
+	CTRL_ERROR	= -1,
+};
+
+/* Ports that the nozomi has */
+enum port_type {
+	PORT_MDM	= 0,
+	PORT_DIAG	= 1,
+	PORT_APP1	= 2,
+	PORT_APP2	= 3,
+	PORT_CTRL	= 4,
+	PORT_ERROR	= -1,
+};
+
+#ifdef __BIG_ENDIAN
+/* Big endian */
+
+struct toggles {
+	unsigned int enabled:5;	/*
+				 * Toggle fields are valid if enabled is 0,
+				 * else A-channels must always be used.
+				 */
+	unsigned int diag_dl:1;
+	unsigned int mdm_dl:1;
+	unsigned int mdm_ul:1;
+} __attribute__ ((packed));
+
+/* Configuration table to read at startup of card */
+/* Is for now only needed during initialization phase */
+struct config_table {
+	u32 signature;
+	u16 product_information;
+	u16 version;
+	u8 pad3[3];
+	struct toggles toggle;
+	u8 pad1[4];
+	u16 dl_mdm_len1;	/*
+				 * If this is 64, it can hold
+				 * 60 bytes + 4 that is length field
+				 */
+	u16 dl_start;
+
+	u16 dl_diag_len1;
+	u16 dl_mdm_len2;	/*
+				 * If this is 64, it can hold
+				 * 60 bytes + 4 that is length field
+				 */
+	u16 dl_app1_len;
+
+	u16 dl_diag_len2;
+	u16 dl_ctrl_len;
+	u16 dl_app2_len;
+	u8 pad2[16];
+	u16 ul_mdm_len1;
+	u16 ul_start;
+	u16 ul_diag_len;
+	u16 ul_mdm_len2;
+	u16 ul_app1_len;
+	u16 ul_app2_len;
+	u16 ul_ctrl_len;
+} __attribute__ ((packed));
+
+/* This stores all control downlink flags */
+struct ctrl_dl {
+	u8 port;
+	unsigned int reserved:4;
+	unsigned int CTS:1;
+	unsigned int RI:1;
+	unsigned int DCD:1;
+	unsigned int DSR:1;
+} __attribute__ ((packed));
+
+/* This stores all control uplink flags */
+struct ctrl_ul {
+	u8 port;
+	unsigned int reserved:6;
+	unsigned int RTS:1;
+	unsigned int DTR:1;
+} __attribute__ ((packed));
+
+#else
+/* Little endian */
+
+/* This represents the toggle information */
+struct toggles {
+	unsigned int mdm_ul:1;
+	unsigned int mdm_dl:1;
+	unsigned int diag_dl:1;
+	unsigned int enabled:5;	/*
+				 * Toggle fields are valid if enabled is 0,
+				 * else A-channels must always be used.
+				 */
+} __attribute__ ((packed));
+
+/* Configuration table to read at startup of card */
+struct config_table {
+	u32 signature;
+	u16 version;
+	u16 product_information;
+	struct toggles toggle;
+	u8 pad1[7];
+	u16 dl_start;
+	u16 dl_mdm_len1;	/*
+				 * If this is 64, it can hold
+				 * 60 bytes + 4 that is length field
+				 */
+	u16 dl_mdm_len2;
+	u16 dl_diag_len1;
+	u16 dl_diag_len2;
+	u16 dl_app1_len;
+	u16 dl_app2_len;
+	u16 dl_ctrl_len;
+	u8 pad2[16];
+	u16 ul_start;
+	u16 ul_mdm_len2;
+	u16 ul_mdm_len1;
+	u16 ul_diag_len;
+	u16 ul_app1_len;
+	u16 ul_app2_len;
+	u16 ul_ctrl_len;
+} __attribute__ ((packed));
+
+/* This stores all control downlink flags */
+struct ctrl_dl {
+	unsigned int DSR:1;
+	unsigned int DCD:1;
+	unsigned int RI:1;
+	unsigned int CTS:1;
+	unsigned int reserved:4;
+	u8 port;
+} __attribute__ ((packed));
+
+/* This stores all control uplink flags */
+struct ctrl_ul {
+	unsigned int DTR:1;
+	unsigned int RTS:1;
+	unsigned int reserved:6;
+	u8 port;
+} __attribute__ ((packed));
+#endif
+
+/* This holds all information that is needed regarding a port */
+struct port {
+	struct tty_port port;
+	u8 update_flow_control;
+	struct ctrl_ul ctrl_ul;
+	struct ctrl_dl ctrl_dl;
+	struct kfifo fifo_ul;
+	void __iomem *dl_addr[2];
+	u32 dl_size[2];
+	u8 toggle_dl;
+	void __iomem *ul_addr[2];
+	u32 ul_size[2];
+	u8 toggle_ul;
+	u16 token_dl;
+
+	wait_queue_head_t tty_wait;
+	struct async_icount tty_icount;
+
+	struct nozomi *dc;
+};
+
+/* Private data one for each card in the system */
+struct nozomi {
+	void __iomem *base_addr;
+	unsigned long flip;
+
+	/* Pointers to registers */
+	void __iomem *reg_iir;
+	void __iomem *reg_fcr;
+	void __iomem *reg_ier;
+
+	u16 last_ier;
+	enum card_type card_type;
+	struct config_table config_table;	/* Configuration table */
+	struct pci_dev *pdev;
+	struct port port[NOZOMI_MAX_PORTS];
+	u8 *send_buf;
+
+	spinlock_t spin_mutex;	/* secures access to registers and tty */
+
+	unsigned int index_start;
+	enum card_state state;
+	u32 open_ttys;
+};
+
+/* Global variables */
+static const struct pci_device_id nozomi_pci_tbl[] = {
+	{PCI_DEVICE(0x1931, 0x000c)},	/* Nozomi HSDPA */
+	{},
+};
+
+MODULE_DEVICE_TABLE(pci, nozomi_pci_tbl);
+
+static struct nozomi *ndevs[NOZOMI_MAX_CARDS];
+static struct tty_driver *ntty_driver;
+
+static const struct tty_port_operations noz_tty_port_ops;
+
+/*
+ * find card by tty_index
+ */
+static inline struct nozomi *get_dc_by_tty(const struct tty_struct *tty)
+{
+	return tty ? ndevs[tty->index / MAX_PORT] : NULL;
+}
+
+static inline struct port *get_port_by_tty(const struct tty_struct *tty)
+{
+	struct nozomi *ndev = get_dc_by_tty(tty);
+	return ndev ? &ndev->port[tty->index % MAX_PORT] : NULL;
+}
+
+/*
+ * TODO:
+ * -Optimize
+ * -Rewrite cleaner
+ */
+
+static void read_mem32(u32 *buf, const void __iomem *mem_addr_start,
+			u32 size_bytes)
+{
+	u32 i = 0;
+	const u32 __iomem *ptr = mem_addr_start;
+	u16 *buf16;
+
+	if (unlikely(!ptr || !buf))
+		goto out;
+
+	/* shortcut for extremely often used cases */
+	switch (size_bytes) {
+	case 2:	/* 2 bytes */
+		buf16 = (u16 *) buf;
+		*buf16 = __le16_to_cpu(readw(ptr));
+		goto out;
+	case 4:	/* 4 bytes */
+		*(buf) = __le32_to_cpu(readl(ptr));
+		goto out;
+	}
+
+	while (i < size_bytes) {
+		if (size_bytes - i == 2) {
+			/* Handle 2 bytes in the end */
+			buf16 = (u16 *) buf;
+			*(buf16) = __le16_to_cpu(readw(ptr));
+			i += 2;
+		} else {
+			/* Read 4 bytes */
+			*(buf) = __le32_to_cpu(readl(ptr));
+			i += 4;
+		}
+		buf++;
+		ptr++;
+	}
+out:
+	return;
+}
+
+/*
+ * TODO:
+ * -Optimize
+ * -Rewrite cleaner
+ */
+static u32 write_mem32(void __iomem *mem_addr_start, const u32 *buf,
+			u32 size_bytes)
+{
+	u32 i = 0;
+	u32 __iomem *ptr = mem_addr_start;
+	const u16 *buf16;
+
+	if (unlikely(!ptr || !buf))
+		return 0;
+
+	/* shortcut for extremely often used cases */
+	switch (size_bytes) {
+	case 2:	/* 2 bytes */
+		buf16 = (const u16 *)buf;
+		writew(__cpu_to_le16(*buf16), ptr);
+		return 2;
+	case 1: /*
+		 * also needs to write 4 bytes in this case
+		 * so falling through..
+		 */
+		fallthrough;
+	case 4: /* 4 bytes */
+		writel(__cpu_to_le32(*buf), ptr);
+		return 4;
+	}
+
+	while (i < size_bytes) {
+		if (size_bytes - i == 2) {
+			/* 2 bytes */
+			buf16 = (const u16 *)buf;
+			writew(__cpu_to_le16(*buf16), ptr);
+			i += 2;
+		} else {
+			/* 4 bytes */
+			writel(__cpu_to_le32(*buf), ptr);
+			i += 4;
+		}
+		buf++;
+		ptr++;
+	}
+	return i;
+}
+
+/* Setup pointers to different channels and also setup buffer sizes. */
+static void nozomi_setup_memory(struct nozomi *dc)
+{
+	void __iomem *offset = dc->base_addr + dc->config_table.dl_start;
+	/* The length reported is including the length field of 4 bytes,
+	 * hence subtract with 4.
+	 */
+	const u16 buff_offset = 4;
+
+	/* Modem port dl configuration */
+	dc->port[PORT_MDM].dl_addr[CH_A] = offset;
+	dc->port[PORT_MDM].dl_addr[CH_B] =
+				(offset += dc->config_table.dl_mdm_len1);
+	dc->port[PORT_MDM].dl_size[CH_A] =
+				dc->config_table.dl_mdm_len1 - buff_offset;
+	dc->port[PORT_MDM].dl_size[CH_B] =
+				dc->config_table.dl_mdm_len2 - buff_offset;
+
+	/* Diag port dl configuration */
+	dc->port[PORT_DIAG].dl_addr[CH_A] =
+				(offset += dc->config_table.dl_mdm_len2);
+	dc->port[PORT_DIAG].dl_size[CH_A] =
+				dc->config_table.dl_diag_len1 - buff_offset;
+	dc->port[PORT_DIAG].dl_addr[CH_B] =
+				(offset += dc->config_table.dl_diag_len1);
+	dc->port[PORT_DIAG].dl_size[CH_B] =
+				dc->config_table.dl_diag_len2 - buff_offset;
+
+	/* App1 port dl configuration */
+	dc->port[PORT_APP1].dl_addr[CH_A] =
+				(offset += dc->config_table.dl_diag_len2);
+	dc->port[PORT_APP1].dl_size[CH_A] =
+				dc->config_table.dl_app1_len - buff_offset;
+
+	/* App2 port dl configuration */
+	dc->port[PORT_APP2].dl_addr[CH_A] =
+				(offset += dc->config_table.dl_app1_len);
+	dc->port[PORT_APP2].dl_size[CH_A] =
+				dc->config_table.dl_app2_len - buff_offset;
+
+	/* Ctrl dl configuration */
+	dc->port[PORT_CTRL].dl_addr[CH_A] =
+				(offset += dc->config_table.dl_app2_len);
+	dc->port[PORT_CTRL].dl_size[CH_A] =
+				dc->config_table.dl_ctrl_len - buff_offset;
+
+	offset = dc->base_addr + dc->config_table.ul_start;
+
+	/* Modem Port ul configuration */
+	dc->port[PORT_MDM].ul_addr[CH_A] = offset;
+	dc->port[PORT_MDM].ul_size[CH_A] =
+				dc->config_table.ul_mdm_len1 - buff_offset;
+	dc->port[PORT_MDM].ul_addr[CH_B] =
+				(offset += dc->config_table.ul_mdm_len1);
+	dc->port[PORT_MDM].ul_size[CH_B] =
+				dc->config_table.ul_mdm_len2 - buff_offset;
+
+	/* Diag port ul configuration */
+	dc->port[PORT_DIAG].ul_addr[CH_A] =
+				(offset += dc->config_table.ul_mdm_len2);
+	dc->port[PORT_DIAG].ul_size[CH_A] =
+				dc->config_table.ul_diag_len - buff_offset;
+
+	/* App1 port ul configuration */
+	dc->port[PORT_APP1].ul_addr[CH_A] =
+				(offset += dc->config_table.ul_diag_len);
+	dc->port[PORT_APP1].ul_size[CH_A] =
+				dc->config_table.ul_app1_len - buff_offset;
+
+	/* App2 port ul configuration */
+	dc->port[PORT_APP2].ul_addr[CH_A] =
+				(offset += dc->config_table.ul_app1_len);
+	dc->port[PORT_APP2].ul_size[CH_A] =
+				dc->config_table.ul_app2_len - buff_offset;
+
+	/* Ctrl ul configuration */
+	dc->port[PORT_CTRL].ul_addr[CH_A] =
+				(offset += dc->config_table.ul_app2_len);
+	dc->port[PORT_CTRL].ul_size[CH_A] =
+				dc->config_table.ul_ctrl_len - buff_offset;
+}
+
+/* Dump config table under initalization phase */
+#ifdef DEBUG
+static void dump_table(const struct nozomi *dc)
+{
+	DBG3("signature: 0x%08X", dc->config_table.signature);
+	DBG3("version: 0x%04X", dc->config_table.version);
+	DBG3("product_information: 0x%04X", \
+				dc->config_table.product_information);
+	DBG3("toggle enabled: %d", dc->config_table.toggle.enabled);
+	DBG3("toggle up_mdm: %d", dc->config_table.toggle.mdm_ul);
+	DBG3("toggle dl_mdm: %d", dc->config_table.toggle.mdm_dl);
+	DBG3("toggle dl_dbg: %d", dc->config_table.toggle.diag_dl);
+
+	DBG3("dl_start: 0x%04X", dc->config_table.dl_start);
+	DBG3("dl_mdm_len0: 0x%04X, %d", dc->config_table.dl_mdm_len1,
+	   dc->config_table.dl_mdm_len1);
+	DBG3("dl_mdm_len1: 0x%04X, %d", dc->config_table.dl_mdm_len2,
+	   dc->config_table.dl_mdm_len2);
+	DBG3("dl_diag_len0: 0x%04X, %d", dc->config_table.dl_diag_len1,
+	   dc->config_table.dl_diag_len1);
+	DBG3("dl_diag_len1: 0x%04X, %d", dc->config_table.dl_diag_len2,
+	   dc->config_table.dl_diag_len2);
+	DBG3("dl_app1_len: 0x%04X, %d", dc->config_table.dl_app1_len,
+	   dc->config_table.dl_app1_len);
+	DBG3("dl_app2_len: 0x%04X, %d", dc->config_table.dl_app2_len,
+	   dc->config_table.dl_app2_len);
+	DBG3("dl_ctrl_len: 0x%04X, %d", dc->config_table.dl_ctrl_len,
+	   dc->config_table.dl_ctrl_len);
+	DBG3("ul_start: 0x%04X, %d", dc->config_table.ul_start,
+	   dc->config_table.ul_start);
+	DBG3("ul_mdm_len[0]: 0x%04X, %d", dc->config_table.ul_mdm_len1,
+	   dc->config_table.ul_mdm_len1);
+	DBG3("ul_mdm_len[1]: 0x%04X, %d", dc->config_table.ul_mdm_len2,
+	   dc->config_table.ul_mdm_len2);
+	DBG3("ul_diag_len: 0x%04X, %d", dc->config_table.ul_diag_len,
+	   dc->config_table.ul_diag_len);
+	DBG3("ul_app1_len: 0x%04X, %d", dc->config_table.ul_app1_len,
+	   dc->config_table.ul_app1_len);
+	DBG3("ul_app2_len: 0x%04X, %d", dc->config_table.ul_app2_len,
+	   dc->config_table.ul_app2_len);
+	DBG3("ul_ctrl_len: 0x%04X, %d", dc->config_table.ul_ctrl_len,
+	   dc->config_table.ul_ctrl_len);
+}
+#else
+static inline void dump_table(const struct nozomi *dc) { }
+#endif
+
+/*
+ * Read configuration table from card under intalization phase
+ * Returns 1 if ok, else 0
+ */
+static int nozomi_read_config_table(struct nozomi *dc)
+{
+	read_mem32((u32 *) &dc->config_table, dc->base_addr + 0,
+						sizeof(struct config_table));
+
+	if (dc->config_table.signature != NOZOMI_CONFIG_MAGIC) {
+		dev_err(&dc->pdev->dev, "ConfigTable Bad! 0x%08X != 0x%08X\n",
+			dc->config_table.signature, NOZOMI_CONFIG_MAGIC);
+		return 0;
+	}
+
+	if ((dc->config_table.version == 0)
+	    || (dc->config_table.toggle.enabled == TOGGLE_VALID)) {
+		int i;
+		DBG1("Second phase, configuring card");
+
+		nozomi_setup_memory(dc);
+
+		dc->port[PORT_MDM].toggle_ul = dc->config_table.toggle.mdm_ul;
+		dc->port[PORT_MDM].toggle_dl = dc->config_table.toggle.mdm_dl;
+		dc->port[PORT_DIAG].toggle_dl = dc->config_table.toggle.diag_dl;
+		DBG1("toggle ports: MDM UL:%d MDM DL:%d, DIAG DL:%d",
+		   dc->port[PORT_MDM].toggle_ul,
+		   dc->port[PORT_MDM].toggle_dl, dc->port[PORT_DIAG].toggle_dl);
+
+		dump_table(dc);
+
+		for (i = PORT_MDM; i < MAX_PORT; i++) {
+			memset(&dc->port[i].ctrl_dl, 0, sizeof(struct ctrl_dl));
+			memset(&dc->port[i].ctrl_ul, 0, sizeof(struct ctrl_ul));
+		}
+
+		/* Enable control channel */
+		dc->last_ier = dc->last_ier | CTRL_DL;
+		writew(dc->last_ier, dc->reg_ier);
+
+		dc->state = NOZOMI_STATE_ALLOCATED;
+		dev_info(&dc->pdev->dev, "Initialization OK!\n");
+		return 1;
+	}
+
+	if ((dc->config_table.version > 0)
+	    && (dc->config_table.toggle.enabled != TOGGLE_VALID)) {
+		u32 offset = 0;
+		DBG1("First phase: pushing upload buffers, clearing download");
+
+		dev_info(&dc->pdev->dev, "Version of card: %d\n",
+			 dc->config_table.version);
+
+		/* Here we should disable all I/O over F32. */
+		nozomi_setup_memory(dc);
+
+		/*
+		 * We should send ALL channel pair tokens back along
+		 * with reset token
+		 */
+
+		/* push upload modem buffers */
+		write_mem32(dc->port[PORT_MDM].ul_addr[CH_A],
+			(u32 *) &offset, 4);
+		write_mem32(dc->port[PORT_MDM].ul_addr[CH_B],
+			(u32 *) &offset, 4);
+
+		writew(MDM_UL | DIAG_DL | MDM_DL, dc->reg_fcr);
+
+		DBG1("First phase done");
+	}
+
+	return 1;
+}
+
+/* Enable uplink interrupts  */
+static void enable_transmit_ul(enum port_type port, struct nozomi *dc)
+{
+	static const u16 mask[] = {MDM_UL, DIAG_UL, APP1_UL, APP2_UL, CTRL_UL};
+
+	if (port < NOZOMI_MAX_PORTS) {
+		dc->last_ier |= mask[port];
+		writew(dc->last_ier, dc->reg_ier);
+	} else {
+		dev_err(&dc->pdev->dev, "Called with wrong port?\n");
+	}
+}
+
+/* Disable uplink interrupts  */
+static void disable_transmit_ul(enum port_type port, struct nozomi *dc)
+{
+	static const u16 mask[] =
+		{~MDM_UL, ~DIAG_UL, ~APP1_UL, ~APP2_UL, ~CTRL_UL};
+
+	if (port < NOZOMI_MAX_PORTS) {
+		dc->last_ier &= mask[port];
+		writew(dc->last_ier, dc->reg_ier);
+	} else {
+		dev_err(&dc->pdev->dev, "Called with wrong port?\n");
+	}
+}
+
+/* Enable downlink interrupts */
+static void enable_transmit_dl(enum port_type port, struct nozomi *dc)
+{
+	static const u16 mask[] = {MDM_DL, DIAG_DL, APP1_DL, APP2_DL, CTRL_DL};
+
+	if (port < NOZOMI_MAX_PORTS) {
+		dc->last_ier |= mask[port];
+		writew(dc->last_ier, dc->reg_ier);
+	} else {
+		dev_err(&dc->pdev->dev, "Called with wrong port?\n");
+	}
+}
+
+/* Disable downlink interrupts */
+static void disable_transmit_dl(enum port_type port, struct nozomi *dc)
+{
+	static const u16 mask[] =
+		{~MDM_DL, ~DIAG_DL, ~APP1_DL, ~APP2_DL, ~CTRL_DL};
+
+	if (port < NOZOMI_MAX_PORTS) {
+		dc->last_ier &= mask[port];
+		writew(dc->last_ier, dc->reg_ier);
+	} else {
+		dev_err(&dc->pdev->dev, "Called with wrong port?\n");
+	}
+}
+
+/*
+ * Return 1 - send buffer to card and ack.
+ * Return 0 - don't ack, don't send buffer to card.
+ */
+static int send_data(enum port_type index, struct nozomi *dc)
+{
+	u32 size = 0;
+	struct port *port = &dc->port[index];
+	const u8 toggle = port->toggle_ul;
+	void __iomem *addr = port->ul_addr[toggle];
+	const u32 ul_size = port->ul_size[toggle];
+
+	/* Get data from tty and place in buf for now */
+	size = kfifo_out(&port->fifo_ul, dc->send_buf,
+			   ul_size < SEND_BUF_MAX ? ul_size : SEND_BUF_MAX);
+
+	if (size == 0) {
+		DBG4("No more data to send, disable link:");
+		return 0;
+	}
+
+	/* DUMP(buf, size); */
+
+	/* Write length + data */
+	write_mem32(addr, (u32 *) &size, 4);
+	write_mem32(addr + 4, (u32 *) dc->send_buf, size);
+
+	tty_port_tty_wakeup(&port->port);
+
+	return 1;
+}
+
+/* If all data has been read, return 1, else 0 */
+static int receive_data(enum port_type index, struct nozomi *dc)
+{
+	u8 buf[RECEIVE_BUF_MAX] = { 0 };
+	int size;
+	u32 offset = 4;
+	struct port *port = &dc->port[index];
+	void __iomem *addr = port->dl_addr[port->toggle_dl];
+	struct tty_struct *tty = tty_port_tty_get(&port->port);
+	int i, ret;
+
+	size = __le32_to_cpu(readl(addr));
+
+	if (tty && tty_throttled(tty)) {
+		DBG1("No room in tty, don't read data, don't ack interrupt, "
+			"disable interrupt");
+
+		/* disable interrupt in downlink... */
+		disable_transmit_dl(index, dc);
+		ret = 0;
+		goto put;
+	}
+
+	if (unlikely(size == 0)) {
+		dev_err(&dc->pdev->dev, "size == 0?\n");
+		ret = 1;
+		goto put;
+	}
+
+	while (size > 0) {
+		read_mem32((u32 *) buf, addr + offset, RECEIVE_BUF_MAX);
+
+		if (size == 1) {
+			tty_insert_flip_char(&port->port, buf[0], TTY_NORMAL);
+			size = 0;
+		} else if (size < RECEIVE_BUF_MAX) {
+			size -= tty_insert_flip_string(&port->port,
+					(char *)buf, size);
+		} else {
+			i = tty_insert_flip_string(&port->port,
+					(char *)buf, RECEIVE_BUF_MAX);
+			size -= i;
+			offset += i;
+		}
+	}
+
+	set_bit(index, &dc->flip);
+	ret = 1;
+put:
+	tty_kref_put(tty);
+	return ret;
+}
+
+/* Debug for interrupts */
+#ifdef DEBUG
+static char *interrupt2str(u16 interrupt)
+{
+	static char buf[TMP_BUF_MAX];
+	char *p = buf;
+
+	if (interrupt & MDM_DL1)
+		p += scnprintf(p, TMP_BUF_MAX, "MDM_DL1 ");
+	if (interrupt & MDM_DL2)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "MDM_DL2 ");
+	if (interrupt & MDM_UL1)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "MDM_UL1 ");
+	if (interrupt & MDM_UL2)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "MDM_UL2 ");
+	if (interrupt & DIAG_DL1)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "DIAG_DL1 ");
+	if (interrupt & DIAG_DL2)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "DIAG_DL2 ");
+
+	if (interrupt & DIAG_UL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "DIAG_UL ");
+
+	if (interrupt & APP1_DL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP1_DL ");
+	if (interrupt & APP2_DL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP2_DL ");
+
+	if (interrupt & APP1_UL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP1_UL ");
+	if (interrupt & APP2_UL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP2_UL ");
+
+	if (interrupt & CTRL_DL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "CTRL_DL ");
+	if (interrupt & CTRL_UL)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "CTRL_UL ");
+
+	if (interrupt & RESET)
+		p += scnprintf(p, TMP_BUF_MAX - (p - buf), "RESET ");
+
+	return buf;
+}
+#endif
+
+/*
+ * Receive flow control
+ * Return 1 - If ok, else 0
+ */
+static int receive_flow_control(struct nozomi *dc)
+{
+	enum port_type port = PORT_MDM;
+	struct ctrl_dl ctrl_dl;
+	struct ctrl_dl old_ctrl;
+	u16 enable_ier = 0;
+
+	read_mem32((u32 *) &ctrl_dl, dc->port[PORT_CTRL].dl_addr[CH_A], 2);
+
+	switch (ctrl_dl.port) {
+	case CTRL_CMD:
+		DBG1("The Base Band sends this value as a response to a "
+			"request for IMSI detach sent over the control "
+			"channel uplink (see section 7.6.1).");
+		break;
+	case CTRL_MDM:
+		port = PORT_MDM;
+		enable_ier = MDM_DL;
+		break;
+	case CTRL_DIAG:
+		port = PORT_DIAG;
+		enable_ier = DIAG_DL;
+		break;
+	case CTRL_APP1:
+		port = PORT_APP1;
+		enable_ier = APP1_DL;
+		break;
+	case CTRL_APP2:
+		port = PORT_APP2;
+		enable_ier = APP2_DL;
+		if (dc->state == NOZOMI_STATE_ALLOCATED) {
+			/*
+			 * After card initialization the flow control
+			 * received for APP2 is always the last
+			 */
+			dc->state = NOZOMI_STATE_READY;
+			dev_info(&dc->pdev->dev, "Device READY!\n");
+		}
+		break;
+	default:
+		dev_err(&dc->pdev->dev,
+			"ERROR: flow control received for non-existing port\n");
+		return 0;
+	}
+
+	DBG1("0x%04X->0x%04X", *((u16 *)&dc->port[port].ctrl_dl),
+	   *((u16 *)&ctrl_dl));
+
+	old_ctrl = dc->port[port].ctrl_dl;
+	dc->port[port].ctrl_dl = ctrl_dl;
+
+	if (old_ctrl.CTS == 1 && ctrl_dl.CTS == 0) {
+		DBG1("Disable interrupt (0x%04X) on port: %d",
+			enable_ier, port);
+		disable_transmit_ul(port, dc);
+
+	} else if (old_ctrl.CTS == 0 && ctrl_dl.CTS == 1) {
+
+		if (kfifo_len(&dc->port[port].fifo_ul)) {
+			DBG1("Enable interrupt (0x%04X) on port: %d",
+				enable_ier, port);
+			DBG1("Data in buffer [%d], enable transmit! ",
+				kfifo_len(&dc->port[port].fifo_ul));
+			enable_transmit_ul(port, dc);
+		} else {
+			DBG1("No data in buffer...");
+		}
+	}
+
+	if (*(u16 *)&old_ctrl == *(u16 *)&ctrl_dl) {
+		DBG1(" No change in mctrl");
+		return 1;
+	}
+	/* Update statistics */
+	if (old_ctrl.CTS != ctrl_dl.CTS)
+		dc->port[port].tty_icount.cts++;
+	if (old_ctrl.DSR != ctrl_dl.DSR)
+		dc->port[port].tty_icount.dsr++;
+	if (old_ctrl.RI != ctrl_dl.RI)
+		dc->port[port].tty_icount.rng++;
+	if (old_ctrl.DCD != ctrl_dl.DCD)
+		dc->port[port].tty_icount.dcd++;
+
+	wake_up_interruptible(&dc->port[port].tty_wait);
+
+	DBG1("port: %d DCD(%d), CTS(%d), RI(%d), DSR(%d)",
+	   port,
+	   dc->port[port].tty_icount.dcd, dc->port[port].tty_icount.cts,
+	   dc->port[port].tty_icount.rng, dc->port[port].tty_icount.dsr);
+
+	return 1;
+}
+
+static enum ctrl_port_type port2ctrl(enum port_type port,
+					const struct nozomi *dc)
+{
+	switch (port) {
+	case PORT_MDM:
+		return CTRL_MDM;
+	case PORT_DIAG:
+		return CTRL_DIAG;
+	case PORT_APP1:
+		return CTRL_APP1;
+	case PORT_APP2:
+		return CTRL_APP2;
+	default:
+		dev_err(&dc->pdev->dev,
+			"ERROR: send flow control " \
+			"received for non-existing port\n");
+	}
+	return CTRL_ERROR;
+}
+
+/*
+ * Send flow control, can only update one channel at a time
+ * Return 0 - If we have updated all flow control
+ * Return 1 - If we need to update more flow control, ack current enable more
+ */
+static int send_flow_control(struct nozomi *dc)
+{
+	u32 i, more_flow_control_to_be_updated = 0;
+	u16 *ctrl;
+
+	for (i = PORT_MDM; i < MAX_PORT; i++) {
+		if (dc->port[i].update_flow_control) {
+			if (more_flow_control_to_be_updated) {
+				/* We have more flow control to be updated */
+				return 1;
+			}
+			dc->port[i].ctrl_ul.port = port2ctrl(i, dc);
+			ctrl = (u16 *)&dc->port[i].ctrl_ul;
+			write_mem32(dc->port[PORT_CTRL].ul_addr[0], \
+				(u32 *) ctrl, 2);
+			dc->port[i].update_flow_control = 0;
+			more_flow_control_to_be_updated = 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Handle downlink data, ports that are handled are modem and diagnostics
+ * Return 1 - ok
+ * Return 0 - toggle fields are out of sync
+ */
+static int handle_data_dl(struct nozomi *dc, enum port_type port, u8 *toggle,
+			u16 read_iir, u16 mask1, u16 mask2)
+{
+	if (*toggle == 0 && read_iir & mask1) {
+		if (receive_data(port, dc)) {
+			writew(mask1, dc->reg_fcr);
+			*toggle = !(*toggle);
+		}
+
+		if (read_iir & mask2) {
+			if (receive_data(port, dc)) {
+				writew(mask2, dc->reg_fcr);
+				*toggle = !(*toggle);
+			}
+		}
+	} else if (*toggle == 1 && read_iir & mask2) {
+		if (receive_data(port, dc)) {
+			writew(mask2, dc->reg_fcr);
+			*toggle = !(*toggle);
+		}
+
+		if (read_iir & mask1) {
+			if (receive_data(port, dc)) {
+				writew(mask1, dc->reg_fcr);
+				*toggle = !(*toggle);
+			}
+		}
+	} else {
+		dev_err(&dc->pdev->dev, "port out of sync!, toggle:%d\n",
+			*toggle);
+		return 0;
+	}
+	return 1;
+}
+
+/*
+ * Handle uplink data, this is currently for the modem port
+ * Return 1 - ok
+ * Return 0 - toggle field are out of sync
+ */
+static int handle_data_ul(struct nozomi *dc, enum port_type port, u16 read_iir)
+{
+	u8 *toggle = &(dc->port[port].toggle_ul);
+
+	if (*toggle == 0 && read_iir & MDM_UL1) {
+		dc->last_ier &= ~MDM_UL;
+		writew(dc->last_ier, dc->reg_ier);
+		if (send_data(port, dc)) {
+			writew(MDM_UL1, dc->reg_fcr);
+			dc->last_ier = dc->last_ier | MDM_UL;
+			writew(dc->last_ier, dc->reg_ier);
+			*toggle = !*toggle;
+		}
+
+		if (read_iir & MDM_UL2) {
+			dc->last_ier &= ~MDM_UL;
+			writew(dc->last_ier, dc->reg_ier);
+			if (send_data(port, dc)) {
+				writew(MDM_UL2, dc->reg_fcr);
+				dc->last_ier = dc->last_ier | MDM_UL;
+				writew(dc->last_ier, dc->reg_ier);
+				*toggle = !*toggle;
+			}
+		}
+
+	} else if (*toggle == 1 && read_iir & MDM_UL2) {
+		dc->last_ier &= ~MDM_UL;
+		writew(dc->last_ier, dc->reg_ier);
+		if (send_data(port, dc)) {
+			writew(MDM_UL2, dc->reg_fcr);
+			dc->last_ier = dc->last_ier | MDM_UL;
+			writew(dc->last_ier, dc->reg_ier);
+			*toggle = !*toggle;
+		}
+
+		if (read_iir & MDM_UL1) {
+			dc->last_ier &= ~MDM_UL;
+			writew(dc->last_ier, dc->reg_ier);
+			if (send_data(port, dc)) {
+				writew(MDM_UL1, dc->reg_fcr);
+				dc->last_ier = dc->last_ier | MDM_UL;
+				writew(dc->last_ier, dc->reg_ier);
+				*toggle = !*toggle;
+			}
+		}
+	} else {
+		writew(read_iir & MDM_UL, dc->reg_fcr);
+		dev_err(&dc->pdev->dev, "port out of sync!\n");
+		return 0;
+	}
+	return 1;
+}
+
+static irqreturn_t interrupt_handler(int irq, void *dev_id)
+{
+	struct nozomi *dc = dev_id;
+	unsigned int a;
+	u16 read_iir;
+
+	if (!dc)
+		return IRQ_NONE;
+
+	spin_lock(&dc->spin_mutex);
+	read_iir = readw(dc->reg_iir);
+
+	/* Card removed */
+	if (read_iir == (u16)-1)
+		goto none;
+	/*
+	 * Just handle interrupt enabled in IER
+	 * (by masking with dc->last_ier)
+	 */
+	read_iir &= dc->last_ier;
+
+	if (read_iir == 0)
+		goto none;
+
+
+	DBG4("%s irq:0x%04X, prev:0x%04X", interrupt2str(read_iir), read_iir,
+		dc->last_ier);
+
+	if (read_iir & RESET) {
+		if (unlikely(!nozomi_read_config_table(dc))) {
+			dc->last_ier = 0x0;
+			writew(dc->last_ier, dc->reg_ier);
+			dev_err(&dc->pdev->dev, "Could not read status from "
+				"card, we should disable interface\n");
+		} else {
+			writew(RESET, dc->reg_fcr);
+		}
+		/* No more useful info if this was the reset interrupt. */
+		goto exit_handler;
+	}
+	if (read_iir & CTRL_UL) {
+		DBG1("CTRL_UL");
+		dc->last_ier &= ~CTRL_UL;
+		writew(dc->last_ier, dc->reg_ier);
+		if (send_flow_control(dc)) {
+			writew(CTRL_UL, dc->reg_fcr);
+			dc->last_ier = dc->last_ier | CTRL_UL;
+			writew(dc->last_ier, dc->reg_ier);
+		}
+	}
+	if (read_iir & CTRL_DL) {
+		receive_flow_control(dc);
+		writew(CTRL_DL, dc->reg_fcr);
+	}
+	if (read_iir & MDM_DL) {
+		if (!handle_data_dl(dc, PORT_MDM,
+				&(dc->port[PORT_MDM].toggle_dl), read_iir,
+				MDM_DL1, MDM_DL2)) {
+			dev_err(&dc->pdev->dev, "MDM_DL out of sync!\n");
+			goto exit_handler;
+		}
+	}
+	if (read_iir & MDM_UL) {
+		if (!handle_data_ul(dc, PORT_MDM, read_iir)) {
+			dev_err(&dc->pdev->dev, "MDM_UL out of sync!\n");
+			goto exit_handler;
+		}
+	}
+	if (read_iir & DIAG_DL) {
+		if (!handle_data_dl(dc, PORT_DIAG,
+				&(dc->port[PORT_DIAG].toggle_dl), read_iir,
+				DIAG_DL1, DIAG_DL2)) {
+			dev_err(&dc->pdev->dev, "DIAG_DL out of sync!\n");
+			goto exit_handler;
+		}
+	}
+	if (read_iir & DIAG_UL) {
+		dc->last_ier &= ~DIAG_UL;
+		writew(dc->last_ier, dc->reg_ier);
+		if (send_data(PORT_DIAG, dc)) {
+			writew(DIAG_UL, dc->reg_fcr);
+			dc->last_ier = dc->last_ier | DIAG_UL;
+			writew(dc->last_ier, dc->reg_ier);
+		}
+	}
+	if (read_iir & APP1_DL) {
+		if (receive_data(PORT_APP1, dc))
+			writew(APP1_DL, dc->reg_fcr);
+	}
+	if (read_iir & APP1_UL) {
+		dc->last_ier &= ~APP1_UL;
+		writew(dc->last_ier, dc->reg_ier);
+		if (send_data(PORT_APP1, dc)) {
+			writew(APP1_UL, dc->reg_fcr);
+			dc->last_ier = dc->last_ier | APP1_UL;
+			writew(dc->last_ier, dc->reg_ier);
+		}
+	}
+	if (read_iir & APP2_DL) {
+		if (receive_data(PORT_APP2, dc))
+			writew(APP2_DL, dc->reg_fcr);
+	}
+	if (read_iir & APP2_UL) {
+		dc->last_ier &= ~APP2_UL;
+		writew(dc->last_ier, dc->reg_ier);
+		if (send_data(PORT_APP2, dc)) {
+			writew(APP2_UL, dc->reg_fcr);
+			dc->last_ier = dc->last_ier | APP2_UL;
+			writew(dc->last_ier, dc->reg_ier);
+		}
+	}
+
+exit_handler:
+	spin_unlock(&dc->spin_mutex);
+
+	for (a = 0; a < NOZOMI_MAX_PORTS; a++)
+		if (test_and_clear_bit(a, &dc->flip))
+			tty_flip_buffer_push(&dc->port[a].port);
+
+	return IRQ_HANDLED;
+none:
+	spin_unlock(&dc->spin_mutex);
+	return IRQ_NONE;
+}
+
+static void nozomi_get_card_type(struct nozomi *dc)
+{
+	int i;
+	u32 size = 0;
+
+	for (i = 0; i < 6; i++)
+		size += pci_resource_len(dc->pdev, i);
+
+	/* Assume card type F32_8 if no match */
+	dc->card_type = size == 2048 ? F32_2 : F32_8;
+
+	dev_info(&dc->pdev->dev, "Card type is: %d\n", dc->card_type);
+}
+
+static void nozomi_setup_private_data(struct nozomi *dc)
+{
+	void __iomem *offset = dc->base_addr + dc->card_type / 2;
+	unsigned int i;
+
+	dc->reg_fcr = (void __iomem *)(offset + R_FCR);
+	dc->reg_iir = (void __iomem *)(offset + R_IIR);
+	dc->reg_ier = (void __iomem *)(offset + R_IER);
+	dc->last_ier = 0;
+	dc->flip = 0;
+
+	dc->port[PORT_MDM].token_dl = MDM_DL;
+	dc->port[PORT_DIAG].token_dl = DIAG_DL;
+	dc->port[PORT_APP1].token_dl = APP1_DL;
+	dc->port[PORT_APP2].token_dl = APP2_DL;
+
+	for (i = 0; i < MAX_PORT; i++)
+		init_waitqueue_head(&dc->port[i].tty_wait);
+}
+
+static ssize_t card_type_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	const struct nozomi *dc = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", dc->card_type);
+}
+static DEVICE_ATTR_RO(card_type);
+
+static ssize_t open_ttys_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	const struct nozomi *dc = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", dc->open_ttys);
+}
+static DEVICE_ATTR_RO(open_ttys);
+
+static void make_sysfs_files(struct nozomi *dc)
+{
+	if (device_create_file(&dc->pdev->dev, &dev_attr_card_type))
+		dev_err(&dc->pdev->dev,
+			"Could not create sysfs file for card_type\n");
+	if (device_create_file(&dc->pdev->dev, &dev_attr_open_ttys))
+		dev_err(&dc->pdev->dev,
+			"Could not create sysfs file for open_ttys\n");
+}
+
+static void remove_sysfs_files(struct nozomi *dc)
+{
+	device_remove_file(&dc->pdev->dev, &dev_attr_card_type);
+	device_remove_file(&dc->pdev->dev, &dev_attr_open_ttys);
+}
+
+/* Allocate memory for one device */
+static int nozomi_card_init(struct pci_dev *pdev,
+				      const struct pci_device_id *ent)
+{
+	int ret;
+	struct nozomi *dc = NULL;
+	int ndev_idx;
+	int i;
+
+	for (ndev_idx = 0; ndev_idx < ARRAY_SIZE(ndevs); ndev_idx++)
+		if (!ndevs[ndev_idx])
+			break;
+
+	if (ndev_idx >= ARRAY_SIZE(ndevs)) {
+		dev_err(&pdev->dev, "no free tty range for this card left\n");
+		ret = -EIO;
+		goto err;
+	}
+
+	dc = kzalloc(sizeof(struct nozomi), GFP_KERNEL);
+	if (unlikely(!dc)) {
+		dev_err(&pdev->dev, "Could not allocate memory\n");
+		ret = -ENOMEM;
+		goto err_free;
+	}
+
+	dc->pdev = pdev;
+
+	ret = pci_enable_device(dc->pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable PCI Device\n");
+		goto err_free;
+	}
+
+	ret = pci_request_regions(dc->pdev, NOZOMI_NAME);
+	if (ret) {
+		dev_err(&pdev->dev, "I/O address 0x%04x already in use\n",
+			(int) /* nozomi_private.io_addr */ 0);
+		goto err_disable_device;
+	}
+
+	/* Find out what card type it is */
+	nozomi_get_card_type(dc);
+
+	dc->base_addr = pci_iomap(dc->pdev, 0, dc->card_type);
+	if (!dc->base_addr) {
+		dev_err(&pdev->dev, "Unable to map card MMIO\n");
+		ret = -ENODEV;
+		goto err_rel_regs;
+	}
+
+	dc->send_buf = kmalloc(SEND_BUF_MAX, GFP_KERNEL);
+	if (!dc->send_buf) {
+		dev_err(&pdev->dev, "Could not allocate send buffer?\n");
+		ret = -ENOMEM;
+		goto err_free_sbuf;
+	}
+
+	for (i = PORT_MDM; i < MAX_PORT; i++) {
+		if (kfifo_alloc(&dc->port[i].fifo_ul, FIFO_BUFFER_SIZE_UL,
+					GFP_KERNEL)) {
+			dev_err(&pdev->dev,
+					"Could not allocate kfifo buffer\n");
+			ret = -ENOMEM;
+			goto err_free_kfifo;
+		}
+	}
+
+	spin_lock_init(&dc->spin_mutex);
+
+	nozomi_setup_private_data(dc);
+
+	/* Disable all interrupts */
+	dc->last_ier = 0;
+	writew(dc->last_ier, dc->reg_ier);
+
+	ret = request_irq(pdev->irq, &interrupt_handler, IRQF_SHARED,
+			NOZOMI_NAME, dc);
+	if (unlikely(ret)) {
+		dev_err(&pdev->dev, "can't request irq %d\n", pdev->irq);
+		goto err_free_all_kfifo;
+	}
+
+	DBG1("base_addr: %p", dc->base_addr);
+
+	make_sysfs_files(dc);
+
+	dc->index_start = ndev_idx * MAX_PORT;
+	ndevs[ndev_idx] = dc;
+
+	pci_set_drvdata(pdev, dc);
+
+	/* Enable RESET interrupt */
+	dc->last_ier = RESET;
+	iowrite16(dc->last_ier, dc->reg_ier);
+
+	dc->state = NOZOMI_STATE_ENABLED;
+
+	for (i = 0; i < MAX_PORT; i++) {
+		struct device *tty_dev;
+		struct port *port = &dc->port[i];
+		port->dc = dc;
+		tty_port_init(&port->port);
+		port->port.ops = &noz_tty_port_ops;
+		tty_dev = tty_port_register_device(&port->port, ntty_driver,
+				dc->index_start + i, &pdev->dev);
+
+		if (IS_ERR(tty_dev)) {
+			ret = PTR_ERR(tty_dev);
+			dev_err(&pdev->dev, "Could not allocate tty?\n");
+			tty_port_destroy(&port->port);
+			goto err_free_tty;
+		}
+	}
+
+	return 0;
+
+err_free_tty:
+	for (i--; i >= 0; i--) {
+		tty_unregister_device(ntty_driver, dc->index_start + i);
+		tty_port_destroy(&dc->port[i].port);
+	}
+	free_irq(pdev->irq, dc);
+err_free_all_kfifo:
+	i = MAX_PORT;
+err_free_kfifo:
+	for (i--; i >= PORT_MDM; i--)
+		kfifo_free(&dc->port[i].fifo_ul);
+err_free_sbuf:
+	kfree(dc->send_buf);
+	iounmap(dc->base_addr);
+err_rel_regs:
+	pci_release_regions(pdev);
+err_disable_device:
+	pci_disable_device(pdev);
+err_free:
+	kfree(dc);
+err:
+	return ret;
+}
+
+static void tty_exit(struct nozomi *dc)
+{
+	unsigned int i;
+
+	for (i = 0; i < MAX_PORT; ++i)
+		tty_port_tty_hangup(&dc->port[i].port, false);
+
+	/* Racy below - surely should wait for scheduled work to be done or
+	   complete off a hangup method ? */
+	while (dc->open_ttys)
+		msleep(1);
+	for (i = 0; i < MAX_PORT; ++i) {
+		tty_unregister_device(ntty_driver, dc->index_start + i);
+		tty_port_destroy(&dc->port[i].port);
+	}
+}
+
+/* Deallocate memory for one device */
+static void nozomi_card_exit(struct pci_dev *pdev)
+{
+	int i;
+	struct ctrl_ul ctrl;
+	struct nozomi *dc = pci_get_drvdata(pdev);
+
+	/* Disable all interrupts */
+	dc->last_ier = 0;
+	writew(dc->last_ier, dc->reg_ier);
+
+	tty_exit(dc);
+
+	/* Send 0x0001, command card to resend the reset token.  */
+	/* This is to get the reset when the module is reloaded. */
+	ctrl.port = 0x00;
+	ctrl.reserved = 0;
+	ctrl.RTS = 0;
+	ctrl.DTR = 1;
+	DBG1("sending flow control 0x%04X", *((u16 *)&ctrl));
+
+	/* Setup dc->reg addresses to we can use defines here */
+	write_mem32(dc->port[PORT_CTRL].ul_addr[0], (u32 *)&ctrl, 2);
+	writew(CTRL_UL, dc->reg_fcr);	/* push the token to the card. */
+
+	remove_sysfs_files(dc);
+
+	free_irq(pdev->irq, dc);
+
+	for (i = 0; i < MAX_PORT; i++)
+		kfifo_free(&dc->port[i].fifo_ul);
+
+	kfree(dc->send_buf);
+
+	iounmap(dc->base_addr);
+
+	pci_release_regions(pdev);
+
+	pci_disable_device(pdev);
+
+	ndevs[dc->index_start / MAX_PORT] = NULL;
+
+	kfree(dc);
+}
+
+static void set_rts(const struct tty_struct *tty, int rts)
+{
+	struct port *port = get_port_by_tty(tty);
+
+	port->ctrl_ul.RTS = rts;
+	port->update_flow_control = 1;
+	enable_transmit_ul(PORT_CTRL, get_dc_by_tty(tty));
+}
+
+static void set_dtr(const struct tty_struct *tty, int dtr)
+{
+	struct port *port = get_port_by_tty(tty);
+
+	DBG1("SETTING DTR index: %d, dtr: %d", tty->index, dtr);
+
+	port->ctrl_ul.DTR = dtr;
+	port->update_flow_control = 1;
+	enable_transmit_ul(PORT_CTRL, get_dc_by_tty(tty));
+}
+
+/*
+ * ----------------------------------------------------------------------------
+ * TTY code
+ * ----------------------------------------------------------------------------
+ */
+
+static int ntty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct port *port = get_port_by_tty(tty);
+	struct nozomi *dc = get_dc_by_tty(tty);
+	int ret;
+	if (!port || !dc || dc->state != NOZOMI_STATE_READY)
+		return -ENODEV;
+	ret = tty_standard_install(driver, tty);
+	if (ret == 0)
+		tty->driver_data = port;
+	return ret;
+}
+
+static void ntty_cleanup(struct tty_struct *tty)
+{
+	tty->driver_data = NULL;
+}
+
+static int ntty_activate(struct tty_port *tport, struct tty_struct *tty)
+{
+	struct port *port = container_of(tport, struct port, port);
+	struct nozomi *dc = port->dc;
+	unsigned long flags;
+
+	DBG1("open: %d", port->token_dl);
+	spin_lock_irqsave(&dc->spin_mutex, flags);
+	dc->last_ier = dc->last_ier | port->token_dl;
+	writew(dc->last_ier, dc->reg_ier);
+	dc->open_ttys++;
+	spin_unlock_irqrestore(&dc->spin_mutex, flags);
+	printk("noz: activated %d: %p\n", tty->index, tport);
+	return 0;
+}
+
+static int ntty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct port *port = tty->driver_data;
+	return tty_port_open(&port->port, tty, filp);
+}
+
+static void ntty_shutdown(struct tty_port *tport)
+{
+	struct port *port = container_of(tport, struct port, port);
+	struct nozomi *dc = port->dc;
+	unsigned long flags;
+
+	DBG1("close: %d", port->token_dl);
+	spin_lock_irqsave(&dc->spin_mutex, flags);
+	dc->last_ier &= ~(port->token_dl);
+	writew(dc->last_ier, dc->reg_ier);
+	dc->open_ttys--;
+	spin_unlock_irqrestore(&dc->spin_mutex, flags);
+	printk("noz: shutdown %p\n", tport);
+}
+
+static void ntty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct port *port = tty->driver_data;
+	if (port)
+		tty_port_close(&port->port, tty, filp);
+}
+
+static void ntty_hangup(struct tty_struct *tty)
+{
+	struct port *port = tty->driver_data;
+	tty_port_hangup(&port->port);
+}
+
+/*
+ * called when the userspace process writes to the tty (/dev/noz*).
+ * Data is inserted into a fifo, which is then read and transferred to the modem.
+ */
+static ssize_t ntty_write(struct tty_struct *tty, const u8 *buffer,
+			  size_t count)
+{
+	int rval = -EINVAL;
+	struct nozomi *dc = get_dc_by_tty(tty);
+	struct port *port = tty->driver_data;
+	unsigned long flags;
+
+	if (!dc || !port)
+		return -ENODEV;
+
+	rval = kfifo_in(&port->fifo_ul, buffer, count);
+
+	spin_lock_irqsave(&dc->spin_mutex, flags);
+	/* CTS is only valid on the modem channel */
+	if (port == &(dc->port[PORT_MDM])) {
+		if (port->ctrl_dl.CTS) {
+			DBG4("Enable interrupt");
+			enable_transmit_ul(tty->index % MAX_PORT, dc);
+		} else {
+			dev_err(&dc->pdev->dev,
+				"CTS not active on modem port?\n");
+		}
+	} else {
+		enable_transmit_ul(tty->index % MAX_PORT, dc);
+	}
+	spin_unlock_irqrestore(&dc->spin_mutex, flags);
+
+	return rval;
+}
+
+/*
+ * Calculate how much is left in device
+ * This method is called by the upper tty layer.
+ *   #according to sources N_TTY.c it expects a value >= 0 and
+ *    does not check for negative values.
+ *
+ * If the port is unplugged report lots of room and let the bits
+ * dribble away so we don't block anything.
+ */
+static unsigned int ntty_write_room(struct tty_struct *tty)
+{
+	struct port *port = tty->driver_data;
+	unsigned int room = 4096;
+	const struct nozomi *dc = get_dc_by_tty(tty);
+
+	if (dc)
+		room = kfifo_avail(&port->fifo_ul);
+
+	return room;
+}
+
+/* Gets io control parameters */
+static int ntty_tiocmget(struct tty_struct *tty)
+{
+	const struct port *port = tty->driver_data;
+	const struct ctrl_dl *ctrl_dl = &port->ctrl_dl;
+	const struct ctrl_ul *ctrl_ul = &port->ctrl_ul;
+
+	/* Note: these could change under us but it is not clear this
+	   matters if so */
+	return (ctrl_ul->RTS ? TIOCM_RTS : 0)
+		| (ctrl_ul->DTR ? TIOCM_DTR : 0)
+		| (ctrl_dl->DCD ? TIOCM_CAR : 0)
+		| (ctrl_dl->RI  ? TIOCM_RNG : 0)
+		| (ctrl_dl->DSR ? TIOCM_DSR : 0)
+		| (ctrl_dl->CTS ? TIOCM_CTS : 0);
+}
+
+/* Sets io controls parameters */
+static int ntty_tiocmset(struct tty_struct *tty,
+					unsigned int set, unsigned int clear)
+{
+	struct nozomi *dc = get_dc_by_tty(tty);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dc->spin_mutex, flags);
+	if (set & TIOCM_RTS)
+		set_rts(tty, 1);
+	else if (clear & TIOCM_RTS)
+		set_rts(tty, 0);
+
+	if (set & TIOCM_DTR)
+		set_dtr(tty, 1);
+	else if (clear & TIOCM_DTR)
+		set_dtr(tty, 0);
+	spin_unlock_irqrestore(&dc->spin_mutex, flags);
+
+	return 0;
+}
+
+static int ntty_cflags_changed(struct port *port, unsigned long flags,
+		struct async_icount *cprev)
+{
+	const struct async_icount cnow = port->tty_icount;
+	int ret;
+
+	ret = ((flags & TIOCM_RNG) && (cnow.rng != cprev->rng))
+		|| ((flags & TIOCM_DSR) && (cnow.dsr != cprev->dsr))
+		|| ((flags & TIOCM_CD)  && (cnow.dcd != cprev->dcd))
+		|| ((flags & TIOCM_CTS) && (cnow.cts != cprev->cts));
+
+	*cprev = cnow;
+
+	return ret;
+}
+
+static int ntty_tiocgicount(struct tty_struct *tty,
+				struct serial_icounter_struct *icount)
+{
+	struct port *port = tty->driver_data;
+	const struct async_icount cnow = port->tty_icount;
+
+	icount->cts = cnow.cts;
+	icount->dsr = cnow.dsr;
+	icount->rng = cnow.rng;
+	icount->dcd = cnow.dcd;
+	icount->rx = cnow.rx;
+	icount->tx = cnow.tx;
+	icount->frame = cnow.frame;
+	icount->overrun = cnow.overrun;
+	icount->parity = cnow.parity;
+	icount->brk = cnow.brk;
+	icount->buf_overrun = cnow.buf_overrun;
+	return 0;
+}
+
+static int ntty_ioctl(struct tty_struct *tty,
+		      unsigned int cmd, unsigned long arg)
+{
+	struct port *port = tty->driver_data;
+	int rval = -ENOIOCTLCMD;
+
+	switch (cmd) {
+	case TIOCMIWAIT: {
+		struct async_icount cprev = port->tty_icount;
+
+		rval = wait_event_interruptible(port->tty_wait,
+				ntty_cflags_changed(port, arg, &cprev));
+		break;
+	}
+	default:
+		DBG1("ERR: 0x%08X, %d", cmd, cmd);
+		break;
+	}
+
+	return rval;
+}
+
+/*
+ * Called by the upper tty layer when tty buffers are ready
+ * to receive data again after a call to throttle.
+ */
+static void ntty_unthrottle(struct tty_struct *tty)
+{
+	struct nozomi *dc = get_dc_by_tty(tty);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dc->spin_mutex, flags);
+	enable_transmit_dl(tty->index % MAX_PORT, dc);
+	set_rts(tty, 1);
+
+	spin_unlock_irqrestore(&dc->spin_mutex, flags);
+}
+
+/*
+ * Called by the upper tty layer when the tty buffers are almost full.
+ * The driver should stop send more data.
+ */
+static void ntty_throttle(struct tty_struct *tty)
+{
+	struct nozomi *dc = get_dc_by_tty(tty);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dc->spin_mutex, flags);
+	set_rts(tty, 0);
+	spin_unlock_irqrestore(&dc->spin_mutex, flags);
+}
+
+/* Returns number of chars in buffer, called by tty layer */
+static unsigned int ntty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct port *port = tty->driver_data;
+	struct nozomi *dc = get_dc_by_tty(tty);
+
+	if (unlikely(!dc || !port))
+		return 0;
+
+	return kfifo_len(&port->fifo_ul);
+}
+
+static const struct tty_port_operations noz_tty_port_ops = {
+	.activate = ntty_activate,
+	.shutdown = ntty_shutdown,
+};
+
+static const struct tty_operations tty_ops = {
+	.ioctl = ntty_ioctl,
+	.open = ntty_open,
+	.close = ntty_close,
+	.hangup = ntty_hangup,
+	.write = ntty_write,
+	.write_room = ntty_write_room,
+	.unthrottle = ntty_unthrottle,
+	.throttle = ntty_throttle,
+	.chars_in_buffer = ntty_chars_in_buffer,
+	.tiocmget = ntty_tiocmget,
+	.tiocmset = ntty_tiocmset,
+	.get_icount = ntty_tiocgicount,
+	.install = ntty_install,
+	.cleanup = ntty_cleanup,
+};
+
+/* Module initialization */
+static struct pci_driver nozomi_driver = {
+	.name = NOZOMI_NAME,
+	.id_table = nozomi_pci_tbl,
+	.probe = nozomi_card_init,
+	.remove = nozomi_card_exit,
+};
+
+static __init int nozomi_init(void)
+{
+	int ret;
+
+	ntty_driver = tty_alloc_driver(NTTY_TTY_MAXMINORS, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(ntty_driver))
+		return PTR_ERR(ntty_driver);
+
+	ntty_driver->driver_name = NOZOMI_NAME_TTY;
+	ntty_driver->name = "noz";
+	ntty_driver->major = 0;
+	ntty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	ntty_driver->subtype = SERIAL_TYPE_NORMAL;
+	ntty_driver->init_termios = tty_std_termios;
+	ntty_driver->init_termios.c_cflag = B115200 | CS8 | CREAD | \
+						HUPCL | CLOCAL;
+	ntty_driver->init_termios.c_ispeed = 115200;
+	ntty_driver->init_termios.c_ospeed = 115200;
+	tty_set_operations(ntty_driver, &tty_ops);
+
+	ret = tty_register_driver(ntty_driver);
+	if (ret) {
+		printk(KERN_ERR "Nozomi: failed to register ntty driver\n");
+		goto free_tty;
+	}
+
+	ret = pci_register_driver(&nozomi_driver);
+	if (ret) {
+		printk(KERN_ERR "Nozomi: can't register pci driver\n");
+		goto unr_tty;
+	}
+
+	return 0;
+unr_tty:
+	tty_unregister_driver(ntty_driver);
+free_tty:
+	tty_driver_kref_put(ntty_driver);
+	return ret;
+}
+
+static __exit void nozomi_exit(void)
+{
+	pci_unregister_driver(&nozomi_driver);
+	tty_unregister_driver(ntty_driver);
+	tty_driver_kref_put(ntty_driver);
+}
+
+module_init(nozomi_init);
+module_exit(nozomi_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Nozomi driver");
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
new file mode 100644
index 000000000..df08f1305
--- /dev/null
+++ b/drivers/tty/pty.c
@@ -0,0 +1,947 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Added support for a Unix98-style ptmx device.
+ *    -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/fcntl.h>
+#include <linux/sched/signal.h>
+#include <linux/string.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/uaccess.h>
+#include <linux/bitops.h>
+#include <linux/devpts_fs.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/mount.h>
+#include <linux/file.h>
+#include <linux/ioctl.h>
+#include <linux/compat.h>
+#include "tty.h"
+
+#undef TTY_DEBUG_HANGUP
+#ifdef TTY_DEBUG_HANGUP
+# define tty_debug_hangup(tty, f, args...)	tty_debug(tty, f, ##args)
+#else
+# define tty_debug_hangup(tty, f, args...)	do {} while (0)
+#endif
+
+#ifdef CONFIG_UNIX98_PTYS
+static struct tty_driver *ptm_driver;
+static struct tty_driver *pts_driver;
+static DEFINE_MUTEX(devpts_mutex);
+#endif
+
+static void pty_close(struct tty_struct *tty, struct file *filp)
+{
+	if (tty->driver->subtype == PTY_TYPE_MASTER)
+		WARN_ON(tty->count > 1);
+	else {
+		if (tty_io_error(tty))
+			return;
+		if (tty->count > 2)
+			return;
+	}
+	set_bit(TTY_IO_ERROR, &tty->flags);
+	wake_up_interruptible(&tty->read_wait);
+	wake_up_interruptible(&tty->write_wait);
+	spin_lock_irq(&tty->ctrl.lock);
+	tty->ctrl.packet = false;
+	spin_unlock_irq(&tty->ctrl.lock);
+	/* Review - krefs on tty_link ?? */
+	if (!tty->link)
+		return;
+	set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+	wake_up_interruptible(&tty->link->read_wait);
+	wake_up_interruptible(&tty->link->write_wait);
+	if (tty->driver->subtype == PTY_TYPE_MASTER) {
+		set_bit(TTY_OTHER_CLOSED, &tty->flags);
+#ifdef CONFIG_UNIX98_PTYS
+		if (tty->driver == ptm_driver) {
+			mutex_lock(&devpts_mutex);
+			if (tty->link->driver_data)
+				devpts_pty_kill(tty->link->driver_data);
+			mutex_unlock(&devpts_mutex);
+		}
+#endif
+		tty_vhangup(tty->link);
+	}
+}
+
+/*
+ * The unthrottle routine is called by the line discipline to signal
+ * that it can receive more characters.  For PTY's, the TTY_THROTTLED
+ * flag is always set, to force the line discipline to always call the
+ * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
+ * characters in the queue.  This is necessary since each time this
+ * happens, we need to wake up any sleeping processes that could be
+ * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
+ * for the pty buffer to be drained.
+ */
+static void pty_unthrottle(struct tty_struct *tty)
+{
+	tty_wakeup(tty->link);
+	set_bit(TTY_THROTTLED, &tty->flags);
+}
+
+/**
+ *	pty_write		-	write to a pty
+ *	@tty: the tty we write from
+ *	@buf: kernel buffer of data
+ *	@c: bytes to write
+ *
+ *	Our "hardware" write method. Data is coming from the ldisc which
+ *	may be in a non sleeping state. We simply throw this at the other
+ *	end of the link as if we were an IRQ handler receiving stuff for
+ *	the other side of the pty/tty pair.
+ */
+
+static ssize_t pty_write(struct tty_struct *tty, const u8 *buf, size_t c)
+{
+	struct tty_struct *to = tty->link;
+
+	if (tty->flow.stopped || !c)
+		return 0;
+
+	return tty_insert_flip_string_and_push_buffer(to->port, buf, c);
+}
+
+/**
+ *	pty_write_room	-	write space
+ *	@tty: tty we are writing from
+ *
+ *	Report how many bytes the ldisc can send into the queue for
+ *	the other device.
+ */
+
+static unsigned int pty_write_room(struct tty_struct *tty)
+{
+	if (tty->flow.stopped)
+		return 0;
+	return tty_buffer_space_avail(tty->link->port);
+}
+
+/* Set the lock flag on a pty */
+static int pty_set_lock(struct tty_struct *tty, int __user *arg)
+{
+	int val;
+
+	if (get_user(val, arg))
+		return -EFAULT;
+	if (val)
+		set_bit(TTY_PTY_LOCK, &tty->flags);
+	else
+		clear_bit(TTY_PTY_LOCK, &tty->flags);
+	return 0;
+}
+
+static int pty_get_lock(struct tty_struct *tty, int __user *arg)
+{
+	int locked = test_bit(TTY_PTY_LOCK, &tty->flags);
+
+	return put_user(locked, arg);
+}
+
+/* Set the packet mode on a pty */
+static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
+{
+	int pktmode;
+
+	if (get_user(pktmode, arg))
+		return -EFAULT;
+
+	spin_lock_irq(&tty->ctrl.lock);
+	if (pktmode) {
+		if (!tty->ctrl.packet) {
+			tty->link->ctrl.pktstatus = 0;
+			smp_mb();
+			tty->ctrl.packet = true;
+		}
+	} else
+		tty->ctrl.packet = false;
+	spin_unlock_irq(&tty->ctrl.lock);
+
+	return 0;
+}
+
+/* Get the packet mode of a pty */
+static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
+{
+	int pktmode = tty->ctrl.packet;
+
+	return put_user(pktmode, arg);
+}
+
+/* Send a signal to the slave */
+static int pty_signal(struct tty_struct *tty, int sig)
+{
+	struct pid *pgrp;
+
+	if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP)
+		return -EINVAL;
+
+	if (tty->link) {
+		pgrp = tty_get_pgrp(tty->link);
+		if (pgrp)
+			kill_pgrp(pgrp, sig, 1);
+		put_pid(pgrp);
+	}
+	return 0;
+}
+
+static void pty_flush_buffer(struct tty_struct *tty)
+{
+	struct tty_struct *to = tty->link;
+
+	if (!to)
+		return;
+
+	tty_buffer_flush(to, NULL);
+	if (to->ctrl.packet) {
+		spin_lock_irq(&tty->ctrl.lock);
+		tty->ctrl.pktstatus |= TIOCPKT_FLUSHWRITE;
+		wake_up_interruptible(&to->read_wait);
+		spin_unlock_irq(&tty->ctrl.lock);
+	}
+}
+
+static int pty_open(struct tty_struct *tty, struct file *filp)
+{
+	if (!tty || !tty->link)
+		return -ENODEV;
+
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		goto out;
+	if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
+		goto out;
+	if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)
+		goto out;
+
+	clear_bit(TTY_IO_ERROR, &tty->flags);
+	clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+	set_bit(TTY_THROTTLED, &tty->flags);
+	return 0;
+
+out:
+	set_bit(TTY_IO_ERROR, &tty->flags);
+	return -EIO;
+}
+
+static void pty_set_termios(struct tty_struct *tty,
+			    const struct ktermios *old_termios)
+{
+	/* See if packet mode change of state. */
+	if (tty->link && tty->link->ctrl.packet) {
+		int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
+		int old_flow = ((old_termios->c_iflag & IXON) &&
+				(old_termios->c_cc[VSTOP] == '\023') &&
+				(old_termios->c_cc[VSTART] == '\021'));
+		int new_flow = (I_IXON(tty) &&
+				STOP_CHAR(tty) == '\023' &&
+				START_CHAR(tty) == '\021');
+		if ((old_flow != new_flow) || extproc) {
+			spin_lock_irq(&tty->ctrl.lock);
+			if (old_flow != new_flow) {
+				tty->ctrl.pktstatus &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
+				if (new_flow)
+					tty->ctrl.pktstatus |= TIOCPKT_DOSTOP;
+				else
+					tty->ctrl.pktstatus |= TIOCPKT_NOSTOP;
+			}
+			if (extproc)
+				tty->ctrl.pktstatus |= TIOCPKT_IOCTL;
+			spin_unlock_irq(&tty->ctrl.lock);
+			wake_up_interruptible(&tty->link->read_wait);
+		}
+	}
+
+	tty->termios.c_cflag &= ~(CSIZE | PARENB);
+	tty->termios.c_cflag |= (CS8 | CREAD);
+}
+
+/**
+ *	pty_resize		-	resize event
+ *	@tty: tty being resized
+ *	@ws: window size being set.
+ *
+ *	Update the termios variables and send the necessary signals to
+ *	peform a terminal resize correctly
+ */
+
+static int pty_resize(struct tty_struct *tty,  struct winsize *ws)
+{
+	struct pid *pgrp, *rpgrp;
+	struct tty_struct *pty = tty->link;
+
+	/* For a PTY we need to lock the tty side */
+	mutex_lock(&tty->winsize_mutex);
+	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+		goto done;
+
+	/* Signal the foreground process group of both ptys */
+	pgrp = tty_get_pgrp(tty);
+	rpgrp = tty_get_pgrp(pty);
+
+	if (pgrp)
+		kill_pgrp(pgrp, SIGWINCH, 1);
+	if (rpgrp != pgrp && rpgrp)
+		kill_pgrp(rpgrp, SIGWINCH, 1);
+
+	put_pid(pgrp);
+	put_pid(rpgrp);
+
+	tty->winsize = *ws;
+	pty->winsize = *ws;	/* Never used so will go away soon */
+done:
+	mutex_unlock(&tty->winsize_mutex);
+	return 0;
+}
+
+/**
+ *	pty_start - start() handler
+ *	pty_stop  - stop() handler
+ *	@tty: tty being flow-controlled
+ *
+ *	Propagates the TIOCPKT status to the master pty.
+ *
+ *	NB: only the master pty can be in packet mode so only the slave
+ *	    needs start()/stop() handlers
+ */
+static void pty_start(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	if (tty->link && tty->link->ctrl.packet) {
+		spin_lock_irqsave(&tty->ctrl.lock, flags);
+		tty->ctrl.pktstatus &= ~TIOCPKT_STOP;
+		tty->ctrl.pktstatus |= TIOCPKT_START;
+		spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+		wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);
+	}
+}
+
+static void pty_stop(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	if (tty->link && tty->link->ctrl.packet) {
+		spin_lock_irqsave(&tty->ctrl.lock, flags);
+		tty->ctrl.pktstatus &= ~TIOCPKT_START;
+		tty->ctrl.pktstatus |= TIOCPKT_STOP;
+		spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+		wake_up_interruptible_poll(&tty->link->read_wait, EPOLLIN);
+	}
+}
+
+/**
+ *	pty_common_install		-	set up the pty pair
+ *	@driver: the pty driver
+ *	@tty: the tty being instantiated
+ *	@legacy: true if this is BSD style
+ *
+ *	Perform the initial set up for the tty/pty pair. Called from the
+ *	tty layer when the port is first opened.
+ *
+ *	Locking: the caller must hold the tty_mutex
+ */
+static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
+		bool legacy)
+{
+	struct tty_struct *o_tty;
+	struct tty_port *ports[2];
+	int idx = tty->index;
+	int retval = -ENOMEM;
+
+	/* Opening the slave first has always returned -EIO */
+	if (driver->subtype != PTY_TYPE_MASTER)
+		return -EIO;
+
+	ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
+	ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
+	if (!ports[0] || !ports[1])
+		goto err;
+	if (!try_module_get(driver->other->owner)) {
+		/* This cannot in fact currently happen */
+		goto err;
+	}
+	o_tty = alloc_tty_struct(driver->other, idx);
+	if (!o_tty)
+		goto err_put_module;
+
+	tty_set_lock_subclass(o_tty);
+	lockdep_set_subclass(&o_tty->termios_rwsem, TTY_LOCK_SLAVE);
+
+	if (legacy) {
+		/* We always use new tty termios data so we can do this
+		   the easy way .. */
+		tty_init_termios(tty);
+		tty_init_termios(o_tty);
+
+		driver->other->ttys[idx] = o_tty;
+		driver->ttys[idx] = tty;
+	} else {
+		memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));
+		tty->termios = driver->init_termios;
+		memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));
+		o_tty->termios = driver->other->init_termios;
+	}
+
+	/*
+	 * Everything allocated ... set up the o_tty structure.
+	 */
+	tty_driver_kref_get(driver->other);
+	/* Establish the links in both directions */
+	tty->link   = o_tty;
+	o_tty->link = tty;
+	tty_port_init(ports[0]);
+	tty_port_init(ports[1]);
+	tty_buffer_set_limit(ports[0], 8192);
+	tty_buffer_set_limit(ports[1], 8192);
+	o_tty->port = ports[0];
+	tty->port = ports[1];
+	o_tty->port->itty = o_tty;
+
+	tty_buffer_set_lock_subclass(o_tty->port);
+
+	tty_driver_kref_get(driver);
+	tty->count++;
+	o_tty->count++;
+	return 0;
+
+err_put_module:
+	module_put(driver->other->owner);
+err:
+	kfree(ports[0]);
+	kfree(ports[1]);
+	return retval;
+}
+
+static void pty_cleanup(struct tty_struct *tty)
+{
+	tty_port_put(tty->port);
+}
+
+/* Traditional BSD devices */
+#ifdef CONFIG_LEGACY_PTYS
+
+static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	return pty_common_install(driver, tty, true);
+}
+
+static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct tty_struct *pair = tty->link;
+
+	driver->ttys[tty->index] = NULL;
+	if (pair)
+		pair->driver->ttys[pair->index] = NULL;
+}
+
+static int pty_bsd_ioctl(struct tty_struct *tty,
+			 unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+		return pty_set_lock(tty, (int __user *) arg);
+	case TIOCGPTLCK: /* Get PT Lock status */
+		return pty_get_lock(tty, (int __user *)arg);
+	case TIOCPKT: /* Set PT packet mode */
+		return pty_set_pktmode(tty, (int __user *)arg);
+	case TIOCGPKT: /* Get PT packet mode */
+		return pty_get_pktmode(tty, (int __user *)arg);
+	case TIOCSIG:    /* Send signal to other side of pty */
+		return pty_signal(tty, (int) arg);
+	case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
+		return -EINVAL;
+	}
+	return -ENOIOCTLCMD;
+}
+
+#ifdef CONFIG_COMPAT
+static long pty_bsd_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	/*
+	 * PTY ioctls don't require any special translation between 32-bit and
+	 * 64-bit userspace, they are already compatible.
+	 */
+	return pty_bsd_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
+}
+#else
+#define pty_bsd_compat_ioctl NULL
+#endif
+
+static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
+/*
+ * not really modular, but the easiest way to keep compat with existing
+ * bootargs behaviour is to continue using module_param here.
+ */
+module_param(legacy_count, int, 0);
+
+/*
+ * The master side of a pty can do TIOCSPTLCK and thus
+ * has pty_bsd_ioctl.
+ */
+static const struct tty_operations master_pty_ops_bsd = {
+	.install = pty_install,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.unthrottle = pty_unthrottle,
+	.ioctl = pty_bsd_ioctl,
+	.compat_ioctl = pty_bsd_compat_ioctl,
+	.cleanup = pty_cleanup,
+	.resize = pty_resize,
+	.remove = pty_remove
+};
+
+static const struct tty_operations slave_pty_ops_bsd = {
+	.install = pty_install,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.unthrottle = pty_unthrottle,
+	.set_termios = pty_set_termios,
+	.cleanup = pty_cleanup,
+	.resize = pty_resize,
+	.start = pty_start,
+	.stop = pty_stop,
+	.remove = pty_remove
+};
+
+static void __init legacy_pty_init(void)
+{
+	struct tty_driver *pty_driver, *pty_slave_driver;
+
+	if (legacy_count <= 0)
+		return;
+
+	pty_driver = tty_alloc_driver(legacy_count,
+			TTY_DRIVER_RESET_TERMIOS |
+			TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_ALLOC);
+	if (IS_ERR(pty_driver))
+		panic("Couldn't allocate pty driver");
+
+	pty_slave_driver = tty_alloc_driver(legacy_count,
+			TTY_DRIVER_RESET_TERMIOS |
+			TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_ALLOC);
+	if (IS_ERR(pty_slave_driver))
+		panic("Couldn't allocate pty slave driver");
+
+	pty_driver->driver_name = "pty_master";
+	pty_driver->name = "pty";
+	pty_driver->major = PTY_MASTER_MAJOR;
+	pty_driver->minor_start = 0;
+	pty_driver->type = TTY_DRIVER_TYPE_PTY;
+	pty_driver->subtype = PTY_TYPE_MASTER;
+	pty_driver->init_termios = tty_std_termios;
+	pty_driver->init_termios.c_iflag = 0;
+	pty_driver->init_termios.c_oflag = 0;
+	pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	pty_driver->init_termios.c_lflag = 0;
+	pty_driver->init_termios.c_ispeed = 38400;
+	pty_driver->init_termios.c_ospeed = 38400;
+	pty_driver->other = pty_slave_driver;
+	tty_set_operations(pty_driver, &master_pty_ops_bsd);
+
+	pty_slave_driver->driver_name = "pty_slave";
+	pty_slave_driver->name = "ttyp";
+	pty_slave_driver->major = PTY_SLAVE_MAJOR;
+	pty_slave_driver->minor_start = 0;
+	pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
+	pty_slave_driver->subtype = PTY_TYPE_SLAVE;
+	pty_slave_driver->init_termios = tty_std_termios;
+	pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	pty_slave_driver->init_termios.c_ispeed = 38400;
+	pty_slave_driver->init_termios.c_ospeed = 38400;
+	pty_slave_driver->other = pty_driver;
+	tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
+
+	if (tty_register_driver(pty_driver))
+		panic("Couldn't register pty driver");
+	if (tty_register_driver(pty_slave_driver))
+		panic("Couldn't register pty slave driver");
+}
+#else
+static inline void legacy_pty_init(void) { }
+#endif
+
+/* Unix98 devices */
+#ifdef CONFIG_UNIX98_PTYS
+static struct cdev ptmx_cdev;
+
+/**
+ *	ptm_open_peer - open the peer of a pty
+ *	@master: the open struct file of the ptmx device node
+ *	@tty: the master of the pty being opened
+ *	@flags: the flags for open
+ *
+ *	Provide a race free way for userspace to open the slave end of a pty
+ *	(where they have the master fd and cannot access or trust the mount
+ *	namespace /dev/pts was mounted inside).
+ */
+int ptm_open_peer(struct file *master, struct tty_struct *tty, int flags)
+{
+	int fd;
+	struct file *filp;
+	int retval = -EINVAL;
+	struct path path;
+
+	if (tty->driver != ptm_driver)
+		return -EIO;
+
+	fd = get_unused_fd_flags(flags);
+	if (fd < 0) {
+		retval = fd;
+		goto err;
+	}
+
+	/* Compute the slave's path */
+	path.mnt = devpts_mntget(master, tty->driver_data);
+	if (IS_ERR(path.mnt)) {
+		retval = PTR_ERR(path.mnt);
+		goto err_put;
+	}
+	path.dentry = tty->link->driver_data;
+
+	filp = dentry_open(&path, flags, current_cred());
+	mntput(path.mnt);
+	if (IS_ERR(filp)) {
+		retval = PTR_ERR(filp);
+		goto err_put;
+	}
+
+	fd_install(fd, filp);
+	return fd;
+
+err_put:
+	put_unused_fd(fd);
+err:
+	return retval;
+}
+
+static int pty_unix98_ioctl(struct tty_struct *tty,
+			    unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+		return pty_set_lock(tty, (int __user *)arg);
+	case TIOCGPTLCK: /* Get PT Lock status */
+		return pty_get_lock(tty, (int __user *)arg);
+	case TIOCPKT: /* Set PT packet mode */
+		return pty_set_pktmode(tty, (int __user *)arg);
+	case TIOCGPKT: /* Get PT packet mode */
+		return pty_get_pktmode(tty, (int __user *)arg);
+	case TIOCGPTN: /* Get PT Number */
+		return put_user(tty->index, (unsigned int __user *)arg);
+	case TIOCSIG:    /* Send signal to other side of pty */
+		return pty_signal(tty, (int) arg);
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+#ifdef CONFIG_COMPAT
+static long pty_unix98_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	/*
+	 * PTY ioctls don't require any special translation between 32-bit and
+	 * 64-bit userspace, they are already compatible.
+	 */
+	return pty_unix98_ioctl(tty, cmd,
+		cmd == TIOCSIG ? arg : (unsigned long)compat_ptr(arg));
+}
+#else
+#define pty_unix98_compat_ioctl NULL
+#endif
+
+/**
+ *	ptm_unix98_lookup	-	find a pty master
+ *	@driver: ptm driver
+ *	@file: unused
+ *	@idx: tty index
+ *
+ *	Look up a pty master device. Called under the tty_mutex for now.
+ *	This provides our locking.
+ */
+
+static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
+		struct file *file, int idx)
+{
+	/* Master must be open via /dev/ptmx */
+	return ERR_PTR(-EIO);
+}
+
+/**
+ *	pts_unix98_lookup	-	find a pty slave
+ *	@driver: pts driver
+ *	@file: file pointer to tty
+ *	@idx: tty index
+ *
+ *	Look up a pty master device. Called under the tty_mutex for now.
+ *	This provides our locking for the tty pointer.
+ */
+
+static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
+		struct file *file, int idx)
+{
+	struct tty_struct *tty;
+
+	mutex_lock(&devpts_mutex);
+	tty = devpts_get_priv(file->f_path.dentry);
+	mutex_unlock(&devpts_mutex);
+	/* Master must be open before slave */
+	if (!tty)
+		return ERR_PTR(-EIO);
+	return tty;
+}
+
+static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	return pty_common_install(driver, tty, false);
+}
+
+/* this is called once with whichever end is closed last */
+static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct pts_fs_info *fsi;
+
+	if (tty->driver->subtype == PTY_TYPE_MASTER)
+		fsi = tty->driver_data;
+	else
+		fsi = tty->link->driver_data;
+
+	if (fsi) {
+		devpts_kill_index(fsi, tty->index);
+		devpts_release(fsi);
+	}
+}
+
+static void pty_show_fdinfo(struct tty_struct *tty, struct seq_file *m)
+{
+	seq_printf(m, "tty-index:\t%d\n", tty->index);
+}
+
+static const struct tty_operations ptm_unix98_ops = {
+	.lookup = ptm_unix98_lookup,
+	.install = pty_unix98_install,
+	.remove = pty_unix98_remove,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.unthrottle = pty_unthrottle,
+	.ioctl = pty_unix98_ioctl,
+	.compat_ioctl = pty_unix98_compat_ioctl,
+	.resize = pty_resize,
+	.cleanup = pty_cleanup,
+	.show_fdinfo = pty_show_fdinfo,
+};
+
+static const struct tty_operations pty_unix98_ops = {
+	.lookup = pts_unix98_lookup,
+	.install = pty_unix98_install,
+	.remove = pty_unix98_remove,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.unthrottle = pty_unthrottle,
+	.set_termios = pty_set_termios,
+	.start = pty_start,
+	.stop = pty_stop,
+	.cleanup = pty_cleanup,
+};
+
+/**
+ *	ptmx_open		-	open a unix 98 pty master
+ *	@inode: inode of device file
+ *	@filp: file pointer to tty
+ *
+ *	Allocate a unix98 pty master device from the ptmx driver.
+ *
+ *	Locking: tty_mutex protects the init_dev work. tty->count should
+ *		protect the rest.
+ *		allocated_ptys_lock handles the list of free pty numbers
+ */
+
+static int ptmx_open(struct inode *inode, struct file *filp)
+{
+	struct pts_fs_info *fsi;
+	struct tty_struct *tty;
+	struct dentry *dentry;
+	int retval;
+	int index;
+
+	nonseekable_open(inode, filp);
+
+	/* We refuse fsnotify events on ptmx, since it's a shared resource */
+	filp->f_mode |= FMODE_NONOTIFY;
+
+	retval = tty_alloc_file(filp);
+	if (retval)
+		return retval;
+
+	fsi = devpts_acquire(filp);
+	if (IS_ERR(fsi)) {
+		retval = PTR_ERR(fsi);
+		goto out_free_file;
+	}
+
+	/* find a device that is not in use. */
+	mutex_lock(&devpts_mutex);
+	index = devpts_new_index(fsi);
+	mutex_unlock(&devpts_mutex);
+
+	retval = index;
+	if (index < 0)
+		goto out_put_fsi;
+
+
+	mutex_lock(&tty_mutex);
+	tty = tty_init_dev(ptm_driver, index);
+	/* The tty returned here is locked so we can safely
+	   drop the mutex */
+	mutex_unlock(&tty_mutex);
+
+	retval = PTR_ERR(tty);
+	if (IS_ERR(tty))
+		goto out;
+
+	/*
+	 * From here on out, the tty is "live", and the index and
+	 * fsi will be killed/put by the tty_release()
+	 */
+	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
+	tty->driver_data = fsi;
+
+	tty_add_file(tty, filp);
+
+	dentry = devpts_pty_new(fsi, index, tty->link);
+	if (IS_ERR(dentry)) {
+		retval = PTR_ERR(dentry);
+		goto err_release;
+	}
+	tty->link->driver_data = dentry;
+
+	retval = ptm_driver->ops->open(tty, filp);
+	if (retval)
+		goto err_release;
+
+	tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
+
+	tty_unlock(tty);
+	return 0;
+err_release:
+	tty_unlock(tty);
+	// This will also put-ref the fsi
+	tty_release(inode, filp);
+	return retval;
+out:
+	devpts_kill_index(fsi, index);
+out_put_fsi:
+	devpts_release(fsi);
+out_free_file:
+	tty_free_file(filp);
+	return retval;
+}
+
+static struct file_operations ptmx_fops __ro_after_init;
+
+static void __init unix98_pty_init(void)
+{
+	ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
+			TTY_DRIVER_RESET_TERMIOS |
+			TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV |
+			TTY_DRIVER_DEVPTS_MEM |
+			TTY_DRIVER_DYNAMIC_ALLOC);
+	if (IS_ERR(ptm_driver))
+		panic("Couldn't allocate Unix98 ptm driver");
+	pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
+			TTY_DRIVER_RESET_TERMIOS |
+			TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV |
+			TTY_DRIVER_DEVPTS_MEM |
+			TTY_DRIVER_DYNAMIC_ALLOC);
+	if (IS_ERR(pts_driver))
+		panic("Couldn't allocate Unix98 pts driver");
+
+	ptm_driver->driver_name = "pty_master";
+	ptm_driver->name = "ptm";
+	ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
+	ptm_driver->minor_start = 0;
+	ptm_driver->type = TTY_DRIVER_TYPE_PTY;
+	ptm_driver->subtype = PTY_TYPE_MASTER;
+	ptm_driver->init_termios = tty_std_termios;
+	ptm_driver->init_termios.c_iflag = 0;
+	ptm_driver->init_termios.c_oflag = 0;
+	ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	ptm_driver->init_termios.c_lflag = 0;
+	ptm_driver->init_termios.c_ispeed = 38400;
+	ptm_driver->init_termios.c_ospeed = 38400;
+	ptm_driver->other = pts_driver;
+	tty_set_operations(ptm_driver, &ptm_unix98_ops);
+
+	pts_driver->driver_name = "pty_slave";
+	pts_driver->name = "pts";
+	pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
+	pts_driver->minor_start = 0;
+	pts_driver->type = TTY_DRIVER_TYPE_PTY;
+	pts_driver->subtype = PTY_TYPE_SLAVE;
+	pts_driver->init_termios = tty_std_termios;
+	pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	pts_driver->init_termios.c_ispeed = 38400;
+	pts_driver->init_termios.c_ospeed = 38400;
+	pts_driver->other = ptm_driver;
+	tty_set_operations(pts_driver, &pty_unix98_ops);
+
+	if (tty_register_driver(ptm_driver))
+		panic("Couldn't register Unix98 ptm driver");
+	if (tty_register_driver(pts_driver))
+		panic("Couldn't register Unix98 pts driver");
+
+	/* Now create the /dev/ptmx special device */
+	tty_default_fops(&ptmx_fops);
+	ptmx_fops.open = ptmx_open;
+
+	cdev_init(&ptmx_cdev, &ptmx_fops);
+	if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
+		panic("Couldn't register /dev/ptmx driver");
+	device_create(&tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+}
+
+#else
+static inline void unix98_pty_init(void) { }
+#endif
+
+static int __init pty_init(void)
+{
+	legacy_pty_init();
+	unix98_pty_init();
+	return 0;
+}
+device_initcall(pty_init);
diff --git a/drivers/tty/rpmsg_tty.c b/drivers/tty/rpmsg_tty.c
new file mode 100644
index 000000000..60a2915f5
--- /dev/null
+++ b/drivers/tty/rpmsg_tty.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 STMicroelectronics - All Rights Reserved
+ *
+ * The rpmsg tty driver implements serial communication on the RPMsg bus to makes
+ * possible for user-space programs to send and receive rpmsg messages as a standard
+ * tty protocol.
+ *
+ * The remote processor can instantiate a new tty by requesting a "rpmsg-tty" RPMsg service.
+ * The "rpmsg-tty" service is directly used for data exchange. No flow control is implemented yet.
+ */
+
+#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/rpmsg.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define RPMSG_TTY_NAME	"ttyRPMSG"
+#define MAX_TTY_RPMSG	32
+
+static DEFINE_IDR(tty_idr);	/* tty instance id */
+static DEFINE_MUTEX(idr_lock);	/* protects tty_idr */
+
+static struct tty_driver *rpmsg_tty_driver;
+
+struct rpmsg_tty_port {
+	struct tty_port		port;	 /* TTY port data */
+	int			id;	 /* TTY rpmsg index */
+	struct rpmsg_device	*rpdev;	 /* rpmsg device */
+};
+
+static int rpmsg_tty_cb(struct rpmsg_device *rpdev, void *data, int len, void *priv, u32 src)
+{
+	struct rpmsg_tty_port *cport = dev_get_drvdata(&rpdev->dev);
+	int copied;
+
+	if (!len)
+		return -EINVAL;
+	copied = tty_insert_flip_string(&cport->port, data, len);
+	if (copied != len)
+		dev_err_ratelimited(&rpdev->dev, "Trunc buffer: available space is %d\n", copied);
+	tty_flip_buffer_push(&cport->port);
+
+	return 0;
+}
+
+static int rpmsg_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct rpmsg_tty_port *cport = idr_find(&tty_idr, tty->index);
+	struct tty_port *port;
+
+	tty->driver_data = cport;
+
+	port = tty_port_get(&cport->port);
+	return tty_port_install(port, driver, tty);
+}
+
+static void rpmsg_tty_cleanup(struct tty_struct *tty)
+{
+	tty_port_put(tty->port);
+}
+
+static int rpmsg_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_open(tty->port, tty, filp);
+}
+
+static void rpmsg_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_close(tty->port, tty, filp);
+}
+
+static ssize_t rpmsg_tty_write(struct tty_struct *tty, const u8 *buf,
+			       size_t len)
+{
+	struct rpmsg_tty_port *cport = tty->driver_data;
+	struct rpmsg_device *rpdev;
+	int msg_max_size, msg_size;
+	int ret;
+
+	rpdev = cport->rpdev;
+
+	msg_max_size = rpmsg_get_mtu(rpdev->ept);
+	if (msg_max_size < 0)
+		return msg_max_size;
+
+	msg_size = min_t(unsigned int, len, msg_max_size);
+
+	/*
+	 * Use rpmsg_trysend instead of rpmsg_send to send the message so the caller is not
+	 * hung until a rpmsg buffer is available. In such case rpmsg_trysend returns -ENOMEM.
+	 */
+	ret = rpmsg_trysend(rpdev->ept, (void *)buf, msg_size);
+	if (ret) {
+		dev_dbg_ratelimited(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
+		return ret;
+	}
+
+	return msg_size;
+}
+
+static unsigned int rpmsg_tty_write_room(struct tty_struct *tty)
+{
+	struct rpmsg_tty_port *cport = tty->driver_data;
+	int size;
+
+	size = rpmsg_get_mtu(cport->rpdev->ept);
+	if (size < 0)
+		return 0;
+
+	return size;
+}
+
+static void rpmsg_tty_hangup(struct tty_struct *tty)
+{
+	tty_port_hangup(tty->port);
+}
+
+static const struct tty_operations rpmsg_tty_ops = {
+	.install	= rpmsg_tty_install,
+	.open		= rpmsg_tty_open,
+	.close		= rpmsg_tty_close,
+	.write		= rpmsg_tty_write,
+	.write_room	= rpmsg_tty_write_room,
+	.hangup		= rpmsg_tty_hangup,
+	.cleanup	= rpmsg_tty_cleanup,
+};
+
+static struct rpmsg_tty_port *rpmsg_tty_alloc_cport(void)
+{
+	struct rpmsg_tty_port *cport;
+	int ret;
+
+	cport = kzalloc(sizeof(*cport), GFP_KERNEL);
+	if (!cport)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&idr_lock);
+	ret = idr_alloc(&tty_idr, cport, 0, MAX_TTY_RPMSG, GFP_KERNEL);
+	mutex_unlock(&idr_lock);
+
+	if (ret < 0) {
+		kfree(cport);
+		return ERR_PTR(ret);
+	}
+
+	cport->id = ret;
+
+	return cport;
+}
+
+static void rpmsg_tty_destruct_port(struct tty_port *port)
+{
+	struct rpmsg_tty_port *cport = container_of(port, struct rpmsg_tty_port, port);
+
+	mutex_lock(&idr_lock);
+	idr_remove(&tty_idr, cport->id);
+	mutex_unlock(&idr_lock);
+
+	kfree(cport);
+}
+
+static const struct tty_port_operations rpmsg_tty_port_ops = {
+	.destruct = rpmsg_tty_destruct_port,
+};
+
+
+static int rpmsg_tty_probe(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_tty_port *cport;
+	struct device *dev = &rpdev->dev;
+	struct device *tty_dev;
+	int ret;
+
+	cport = rpmsg_tty_alloc_cport();
+	if (IS_ERR(cport))
+		return dev_err_probe(dev, PTR_ERR(cport), "Failed to alloc tty port\n");
+
+	tty_port_init(&cport->port);
+	cport->port.ops = &rpmsg_tty_port_ops;
+
+	tty_dev = tty_port_register_device(&cport->port, rpmsg_tty_driver,
+					   cport->id, dev);
+	if (IS_ERR(tty_dev)) {
+		ret = dev_err_probe(dev, PTR_ERR(tty_dev), "Failed to register tty port\n");
+		tty_port_put(&cport->port);
+		return ret;
+	}
+
+	cport->rpdev = rpdev;
+
+	dev_set_drvdata(dev, cport);
+
+	dev_dbg(dev, "New channel: 0x%x -> 0x%x: " RPMSG_TTY_NAME "%d\n",
+		rpdev->src, rpdev->dst, cport->id);
+
+	return 0;
+}
+
+static void rpmsg_tty_remove(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_tty_port *cport = dev_get_drvdata(&rpdev->dev);
+
+	dev_dbg(&rpdev->dev, "Removing rpmsg tty device %d\n", cport->id);
+
+	/* User hang up to release the tty */
+	tty_port_tty_hangup(&cport->port, false);
+
+	tty_unregister_device(rpmsg_tty_driver, cport->id);
+
+	tty_port_put(&cport->port);
+}
+
+static struct rpmsg_device_id rpmsg_driver_tty_id_table[] = {
+	{ .name	= "rpmsg-tty" },
+	{ },
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_tty_id_table);
+
+static struct rpmsg_driver rpmsg_tty_rpmsg_drv = {
+	.drv.name	= KBUILD_MODNAME,
+	.id_table	= rpmsg_driver_tty_id_table,
+	.probe		= rpmsg_tty_probe,
+	.callback	= rpmsg_tty_cb,
+	.remove		= rpmsg_tty_remove,
+};
+
+static int __init rpmsg_tty_init(void)
+{
+	int ret;
+
+	rpmsg_tty_driver = tty_alloc_driver(MAX_TTY_RPMSG, TTY_DRIVER_REAL_RAW |
+					    TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(rpmsg_tty_driver))
+		return PTR_ERR(rpmsg_tty_driver);
+
+	rpmsg_tty_driver->driver_name = "rpmsg_tty";
+	rpmsg_tty_driver->name = RPMSG_TTY_NAME;
+	rpmsg_tty_driver->major = 0;
+	rpmsg_tty_driver->type = TTY_DRIVER_TYPE_CONSOLE;
+
+	/* Disable unused mode by default */
+	rpmsg_tty_driver->init_termios = tty_std_termios;
+	rpmsg_tty_driver->init_termios.c_lflag &= ~(ECHO | ICANON);
+	rpmsg_tty_driver->init_termios.c_oflag &= ~(OPOST | ONLCR);
+
+	tty_set_operations(rpmsg_tty_driver, &rpmsg_tty_ops);
+
+	ret = tty_register_driver(rpmsg_tty_driver);
+	if (ret < 0) {
+		pr_err("Couldn't install driver: %d\n", ret);
+		goto error_put;
+	}
+
+	ret = register_rpmsg_driver(&rpmsg_tty_rpmsg_drv);
+	if (ret < 0) {
+		pr_err("Couldn't register driver: %d\n", ret);
+		goto error_unregister;
+	}
+
+	return 0;
+
+error_unregister:
+	tty_unregister_driver(rpmsg_tty_driver);
+
+error_put:
+	tty_driver_kref_put(rpmsg_tty_driver);
+
+	return ret;
+}
+
+static void __exit rpmsg_tty_exit(void)
+{
+	unregister_rpmsg_driver(&rpmsg_tty_rpmsg_drv);
+	tty_unregister_driver(rpmsg_tty_driver);
+	tty_driver_kref_put(rpmsg_tty_driver);
+	idr_destroy(&tty_idr);
+}
+
+module_init(rpmsg_tty_init);
+module_exit(rpmsg_tty_exit);
+
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>");
+MODULE_DESCRIPTION("remote processor messaging tty driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serdev/Kconfig b/drivers/tty/serdev/Kconfig
new file mode 100644
index 000000000..46ae732bf
--- /dev/null
+++ b/drivers/tty/serdev/Kconfig
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Serial bus device driver configuration
+#
+menuconfig SERIAL_DEV_BUS
+	tristate "Serial device bus"
+	help
+	  Core support for devices connected via a serial port.
+
+	  Note that you typically also want to enable TTY port controller support.
+
+if SERIAL_DEV_BUS
+
+config SERIAL_DEV_CTRL_TTYPORT
+	bool "Serial device TTY port controller"
+	help
+	  Say Y here if you want to use the Serial device bus with common TTY
+	  drivers (e.g. serial drivers).
+
+	  If unsure, say Y.
+	depends on TTY
+	depends on SERIAL_DEV_BUS != m
+	default y
+
+endif
diff --git a/drivers/tty/serdev/Makefile b/drivers/tty/serdev/Makefile
new file mode 100644
index 000000000..078417e5b
--- /dev/null
+++ b/drivers/tty/serdev/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+serdev-objs := core.o
+
+obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o
+
+obj-$(CONFIG_SERIAL_DEV_CTRL_TTYPORT) += serdev-ttyport.o
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
new file mode 100644
index 000000000..e7d663901
--- /dev/null
+++ b/drivers/tty/serdev/core.c
@@ -0,0 +1,885 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
+ *
+ * Based on drivers/spmi/spmi.c:
+ * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include <linux/errno.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/slab.h>
+#include <linux/platform_data/x86/apple.h>
+
+static bool is_registered;
+static DEFINE_IDA(ctrl_ida);
+
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+	if (len != -ENODEV)
+		return len;
+
+	return of_device_modalias(dev, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *serdev_device_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(serdev_device);
+
+static int serdev_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	int rc;
+
+	/* TODO: platform modalias */
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
+
+	return of_device_uevent_modalias(dev, env);
+}
+
+static void serdev_device_release(struct device *dev)
+{
+	struct serdev_device *serdev = to_serdev_device(dev);
+	kfree(serdev);
+}
+
+static const struct device_type serdev_device_type = {
+	.groups		= serdev_device_groups,
+	.uevent		= serdev_device_uevent,
+	.release	= serdev_device_release,
+};
+
+static bool is_serdev_device(const struct device *dev)
+{
+	return dev->type == &serdev_device_type;
+}
+
+static void serdev_ctrl_release(struct device *dev)
+{
+	struct serdev_controller *ctrl = to_serdev_controller(dev);
+	ida_simple_remove(&ctrl_ida, ctrl->nr);
+	kfree(ctrl);
+}
+
+static const struct device_type serdev_ctrl_type = {
+	.release	= serdev_ctrl_release,
+};
+
+static int serdev_device_match(struct device *dev, struct device_driver *drv)
+{
+	if (!is_serdev_device(dev))
+		return 0;
+
+	/* TODO: platform matching */
+	if (acpi_driver_match_device(dev, drv))
+		return 1;
+
+	return of_driver_match_device(dev, drv);
+}
+
+/**
+ * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
+ * @serdev:	serdev_device to be added
+ */
+int serdev_device_add(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+	struct device *parent = serdev->dev.parent;
+	int err;
+
+	dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
+
+	/* Only a single slave device is currently supported. */
+	if (ctrl->serdev) {
+		dev_err(&serdev->dev, "controller busy\n");
+		return -EBUSY;
+	}
+	ctrl->serdev = serdev;
+
+	err = device_add(&serdev->dev);
+	if (err < 0) {
+		dev_err(&serdev->dev, "Can't add %s, status %pe\n",
+			dev_name(&serdev->dev), ERR_PTR(err));
+		goto err_clear_serdev;
+	}
+
+	dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
+
+	return 0;
+
+err_clear_serdev:
+	ctrl->serdev = NULL;
+	return err;
+}
+EXPORT_SYMBOL_GPL(serdev_device_add);
+
+/**
+ * serdev_device_remove(): remove an serdev device
+ * @serdev:	serdev_device to be removed
+ */
+void serdev_device_remove(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	device_unregister(&serdev->dev);
+	ctrl->serdev = NULL;
+}
+EXPORT_SYMBOL_GPL(serdev_device_remove);
+
+int serdev_device_open(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+	int ret;
+
+	if (!ctrl || !ctrl->ops->open)
+		return -EINVAL;
+
+	ret = ctrl->ops->open(ctrl);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_get_sync(&ctrl->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&ctrl->dev);
+		goto err_close;
+	}
+
+	return 0;
+
+err_close:
+	if (ctrl->ops->close)
+		ctrl->ops->close(ctrl);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(serdev_device_open);
+
+void serdev_device_close(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->close)
+		return;
+
+	pm_runtime_put(&ctrl->dev);
+
+	ctrl->ops->close(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_close);
+
+static void devm_serdev_device_release(struct device *dev, void *dr)
+{
+	serdev_device_close(*(struct serdev_device **)dr);
+}
+
+int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
+{
+	struct serdev_device **dr;
+	int ret;
+
+	dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	*dr = serdev;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_serdev_device_open);
+
+void serdev_device_write_wakeup(struct serdev_device *serdev)
+{
+	complete(&serdev->write_comp);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
+
+/**
+ * serdev_device_write_buf() - write data asynchronously
+ * @serdev:	serdev device
+ * @buf:	data to be written
+ * @count:	number of bytes to write
+ *
+ * Write data to the device asynchronously.
+ *
+ * Note that any accepted data has only been buffered by the controller; use
+ * serdev_device_wait_until_sent() to make sure the controller write buffer
+ * has actually been emptied.
+ *
+ * Return: The number of bytes written (less than count if not enough room in
+ * the write buffer), or a negative errno on errors.
+ */
+int serdev_device_write_buf(struct serdev_device *serdev,
+			    const unsigned char *buf, size_t count)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->write_buf)
+		return -EINVAL;
+
+	return ctrl->ops->write_buf(ctrl, buf, count);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_buf);
+
+/**
+ * serdev_device_write() - write data synchronously
+ * @serdev:	serdev device
+ * @buf:	data to be written
+ * @count:	number of bytes to write
+ * @timeout:	timeout in jiffies, or 0 to wait indefinitely
+ *
+ * Write data to the device synchronously by repeatedly calling
+ * serdev_device_write() until the controller has accepted all data (unless
+ * interrupted by a timeout or a signal).
+ *
+ * Note that any accepted data has only been buffered by the controller; use
+ * serdev_device_wait_until_sent() to make sure the controller write buffer
+ * has actually been emptied.
+ *
+ * Note that this function depends on serdev_device_write_wakeup() being
+ * called in the serdev driver write_wakeup() callback.
+ *
+ * Return: The number of bytes written (less than count if interrupted),
+ * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
+ * a negative errno on errors.
+ */
+int serdev_device_write(struct serdev_device *serdev,
+			const unsigned char *buf, size_t count,
+			long timeout)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+	int written = 0;
+	int ret;
+
+	if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
+		return -EINVAL;
+
+	if (timeout == 0)
+		timeout = MAX_SCHEDULE_TIMEOUT;
+
+	mutex_lock(&serdev->write_lock);
+	do {
+		reinit_completion(&serdev->write_comp);
+
+		ret = ctrl->ops->write_buf(ctrl, buf, count);
+		if (ret < 0)
+			break;
+
+		written += ret;
+		buf += ret;
+		count -= ret;
+
+		if (count == 0)
+			break;
+
+		timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
+								    timeout);
+	} while (timeout > 0);
+	mutex_unlock(&serdev->write_lock);
+
+	if (ret < 0)
+		return ret;
+
+	if (timeout <= 0 && written == 0) {
+		if (timeout == -ERESTARTSYS)
+			return -ERESTARTSYS;
+		else
+			return -ETIMEDOUT;
+	}
+
+	return written;
+}
+EXPORT_SYMBOL_GPL(serdev_device_write);
+
+void serdev_device_write_flush(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->write_flush)
+		return;
+
+	ctrl->ops->write_flush(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_flush);
+
+int serdev_device_write_room(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->write_room)
+		return 0;
+
+	return serdev->ctrl->ops->write_room(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_room);
+
+unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_baudrate)
+		return 0;
+
+	return ctrl->ops->set_baudrate(ctrl, speed);
+
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
+
+void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_flow_control)
+		return;
+
+	ctrl->ops->set_flow_control(ctrl, enable);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
+
+int serdev_device_set_parity(struct serdev_device *serdev,
+			     enum serdev_parity parity)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_parity)
+		return -EOPNOTSUPP;
+
+	return ctrl->ops->set_parity(ctrl, parity);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_parity);
+
+void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->wait_until_sent)
+		return;
+
+	ctrl->ops->wait_until_sent(ctrl, timeout);
+}
+EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
+
+int serdev_device_get_tiocm(struct serdev_device *serdev)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->get_tiocm)
+		return -EOPNOTSUPP;
+
+	return ctrl->ops->get_tiocm(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
+
+int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->set_tiocm)
+		return -EOPNOTSUPP;
+
+	return ctrl->ops->set_tiocm(ctrl, set, clear);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
+
+int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->break_ctl)
+		return -EOPNOTSUPP;
+
+	return ctrl->ops->break_ctl(ctrl, break_state);
+}
+EXPORT_SYMBOL_GPL(serdev_device_break_ctl);
+
+static int serdev_drv_probe(struct device *dev)
+{
+	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
+	int ret;
+
+	ret = dev_pm_domain_attach(dev, true);
+	if (ret)
+		return ret;
+
+	ret = sdrv->probe(to_serdev_device(dev));
+	if (ret)
+		dev_pm_domain_detach(dev, true);
+
+	return ret;
+}
+
+static void serdev_drv_remove(struct device *dev)
+{
+	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
+	if (sdrv->remove)
+		sdrv->remove(to_serdev_device(dev));
+
+	dev_pm_domain_detach(dev, true);
+}
+
+static struct bus_type serdev_bus_type = {
+	.name		= "serial",
+	.match		= serdev_device_match,
+	.probe		= serdev_drv_probe,
+	.remove		= serdev_drv_remove,
+};
+
+/**
+ * serdev_device_alloc() - Allocate a new serdev device
+ * @ctrl:	associated controller
+ *
+ * Caller is responsible for either calling serdev_device_add() to add the
+ * newly allocated controller, or calling serdev_device_put() to discard it.
+ */
+struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
+{
+	struct serdev_device *serdev;
+
+	serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
+	if (!serdev)
+		return NULL;
+
+	serdev->ctrl = ctrl;
+	device_initialize(&serdev->dev);
+	serdev->dev.parent = &ctrl->dev;
+	serdev->dev.bus = &serdev_bus_type;
+	serdev->dev.type = &serdev_device_type;
+	init_completion(&serdev->write_comp);
+	mutex_init(&serdev->write_lock);
+	return serdev;
+}
+EXPORT_SYMBOL_GPL(serdev_device_alloc);
+
+/**
+ * serdev_controller_alloc() - Allocate a new serdev controller
+ * @parent:	parent device
+ * @size:	size of private data
+ *
+ * Caller is responsible for either calling serdev_controller_add() to add the
+ * newly allocated controller, or calling serdev_controller_put() to discard it.
+ * The allocated private data region may be accessed via
+ * serdev_controller_get_drvdata()
+ */
+struct serdev_controller *serdev_controller_alloc(struct device *parent,
+					      size_t size)
+{
+	struct serdev_controller *ctrl;
+	int id;
+
+	if (WARN_ON(!parent))
+		return NULL;
+
+	ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
+	if (!ctrl)
+		return NULL;
+
+	id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		dev_err(parent,
+			"unable to allocate serdev controller identifier.\n");
+		goto err_free;
+	}
+
+	ctrl->nr = id;
+
+	device_initialize(&ctrl->dev);
+	ctrl->dev.type = &serdev_ctrl_type;
+	ctrl->dev.bus = &serdev_bus_type;
+	ctrl->dev.parent = parent;
+	ctrl->dev.of_node = parent->of_node;
+	serdev_controller_set_drvdata(ctrl, &ctrl[1]);
+
+	dev_set_name(&ctrl->dev, "serial%d", id);
+
+	pm_runtime_no_callbacks(&ctrl->dev);
+	pm_suspend_ignore_children(&ctrl->dev, true);
+
+	dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
+	return ctrl;
+
+err_free:
+	kfree(ctrl);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(serdev_controller_alloc);
+
+static int of_serdev_register_devices(struct serdev_controller *ctrl)
+{
+	struct device_node *node;
+	struct serdev_device *serdev = NULL;
+	int err;
+	bool found = false;
+
+	for_each_available_child_of_node(ctrl->dev.of_node, node) {
+		if (!of_get_property(node, "compatible", NULL))
+			continue;
+
+		dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
+
+		serdev = serdev_device_alloc(ctrl);
+		if (!serdev)
+			continue;
+
+		device_set_node(&serdev->dev, of_fwnode_handle(node));
+
+		err = serdev_device_add(serdev);
+		if (err) {
+			dev_err(&serdev->dev,
+				"failure adding device. status %pe\n",
+				ERR_PTR(err));
+			serdev_device_put(serdev);
+		} else
+			found = true;
+	}
+	if (!found)
+		return -ENODEV;
+
+	return 0;
+}
+
+#ifdef CONFIG_ACPI
+
+#define SERDEV_ACPI_MAX_SCAN_DEPTH 32
+
+struct acpi_serdev_lookup {
+	acpi_handle device_handle;
+	acpi_handle controller_handle;
+	int n;
+	int index;
+};
+
+/**
+ * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
+ * @ares:	ACPI resource
+ * @uart:	Pointer to UARTSerialBus resource will be returned here
+ *
+ * Checks if the given ACPI resource is of type UARTSerialBus.
+ * In this case, returns a pointer to it to the caller.
+ *
+ * Return: True if resource type is of UARTSerialBus, otherwise false.
+ */
+bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
+				   struct acpi_resource_uart_serialbus **uart)
+{
+	struct acpi_resource_uart_serialbus *sb;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+		return false;
+
+	sb = &ares->data.uart_serial_bus;
+	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
+		return false;
+
+	*uart = sb;
+	return true;
+}
+EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
+
+static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
+{
+	struct acpi_serdev_lookup *lookup = data;
+	struct acpi_resource_uart_serialbus *sb;
+	acpi_status status;
+
+	if (!serdev_acpi_get_uart_resource(ares, &sb))
+		return 1;
+
+	if (lookup->index != -1 && lookup->n++ != lookup->index)
+		return 1;
+
+	status = acpi_get_handle(lookup->device_handle,
+				 sb->resource_source.string_ptr,
+				 &lookup->controller_handle);
+	if (ACPI_FAILURE(status))
+		return 1;
+
+	/*
+	 * NOTE: Ideally, we would also want to retrieve other properties here,
+	 * once setting them before opening the device is supported by serdev.
+	 */
+
+	return 1;
+}
+
+static int acpi_serdev_do_lookup(struct acpi_device *adev,
+                                 struct acpi_serdev_lookup *lookup)
+{
+	struct list_head resource_list;
+	int ret;
+
+	lookup->device_handle = acpi_device_handle(adev);
+	lookup->controller_handle = NULL;
+	lookup->n = 0;
+
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     acpi_serdev_parse_resource, lookup);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (ret < 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int acpi_serdev_check_resources(struct serdev_controller *ctrl,
+				       struct acpi_device *adev)
+{
+	struct acpi_serdev_lookup lookup;
+	int ret;
+
+	if (acpi_bus_get_status(adev) || !adev->status.present)
+		return -EINVAL;
+
+	/* Look for UARTSerialBusV2 resource */
+	lookup.index = -1;	// we only care for the last device
+
+	ret = acpi_serdev_do_lookup(adev, &lookup);
+	if (ret)
+		return ret;
+
+	/*
+	 * Apple machines provide an empty resource template, so on those
+	 * machines just look for immediate children with a "baud" property
+	 * (from the _DSM method) instead.
+	 */
+	if (!lookup.controller_handle && x86_apple_machine &&
+	    !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL))
+		acpi_get_parent(adev->handle, &lookup.controller_handle);
+
+	/* Make sure controller and ResourceSource handle match */
+	if (ACPI_HANDLE(ctrl->dev.parent) != lookup.controller_handle)
+		return -ENODEV;
+
+	return 0;
+}
+
+static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
+					       struct acpi_device *adev)
+{
+	struct serdev_device *serdev;
+	int err;
+
+	serdev = serdev_device_alloc(ctrl);
+	if (!serdev) {
+		dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
+			dev_name(&adev->dev));
+		return AE_NO_MEMORY;
+	}
+
+	ACPI_COMPANION_SET(&serdev->dev, adev);
+	acpi_device_set_enumerated(adev);
+
+	err = serdev_device_add(serdev);
+	if (err) {
+		dev_err(&serdev->dev,
+			"failure adding ACPI serdev device. status %pe\n",
+			ERR_PTR(err));
+		serdev_device_put(serdev);
+	}
+
+	return AE_OK;
+}
+
+static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
+	{ "INT3511", 0 },
+	{ "INT3512", 0 },
+	{ },
+};
+
+static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
+					  void *data, void **return_value)
+{
+	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
+	struct serdev_controller *ctrl = data;
+
+	if (!adev || acpi_device_enumerated(adev))
+		return AE_OK;
+
+	/* Skip if black listed */
+	if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
+		return AE_OK;
+
+	if (acpi_serdev_check_resources(ctrl, adev))
+		return AE_OK;
+
+	return acpi_serdev_register_device(ctrl, adev);
+}
+
+
+static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
+{
+	acpi_status status;
+	bool skip;
+	int ret;
+
+	if (!has_acpi_companion(ctrl->dev.parent))
+		return -ENODEV;
+
+	/*
+	 * Skip registration on boards where the ACPI tables are known to
+	 * contain buggy devices. Note serdev_controller_add() must still
+	 * succeed in this case, so that the proper serdev devices can be
+	 * added "manually" later.
+	 */
+	ret = acpi_quirk_skip_serdev_enumeration(ctrl->dev.parent, &skip);
+	if (ret)
+		return ret;
+	if (skip)
+		return 0;
+
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+				     SERDEV_ACPI_MAX_SCAN_DEPTH,
+				     acpi_serdev_add_device, NULL, ctrl, NULL);
+	if (ACPI_FAILURE(status))
+		dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n");
+
+	if (!ctrl->serdev)
+		return -ENODEV;
+
+	return 0;
+}
+#else
+static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
+{
+	return -ENODEV;
+}
+#endif /* CONFIG_ACPI */
+
+/**
+ * serdev_controller_add() - Add an serdev controller
+ * @ctrl:	controller to be registered.
+ *
+ * Register a controller previously allocated via serdev_controller_alloc() with
+ * the serdev core.
+ */
+int serdev_controller_add(struct serdev_controller *ctrl)
+{
+	int ret_of, ret_acpi, ret;
+
+	/* Can't register until after driver model init */
+	if (WARN_ON(!is_registered))
+		return -EAGAIN;
+
+	ret = device_add(&ctrl->dev);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(&ctrl->dev);
+
+	ret_of = of_serdev_register_devices(ctrl);
+	ret_acpi = acpi_serdev_register_devices(ctrl);
+	if (ret_of && ret_acpi) {
+		dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
+			ERR_PTR(ret_of), ERR_PTR(ret_acpi));
+		ret = -ENODEV;
+		goto err_rpm_disable;
+	}
+
+	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
+		ctrl->nr, &ctrl->dev);
+	return 0;
+
+err_rpm_disable:
+	pm_runtime_disable(&ctrl->dev);
+	device_del(&ctrl->dev);
+	return ret;
+};
+EXPORT_SYMBOL_GPL(serdev_controller_add);
+
+/* Remove a device associated with a controller */
+static int serdev_remove_device(struct device *dev, void *data)
+{
+	struct serdev_device *serdev = to_serdev_device(dev);
+	if (dev->type == &serdev_device_type)
+		serdev_device_remove(serdev);
+	return 0;
+}
+
+/**
+ * serdev_controller_remove(): remove an serdev controller
+ * @ctrl:	controller to remove
+ *
+ * Remove a serdev controller.  Caller is responsible for calling
+ * serdev_controller_put() to discard the allocated controller.
+ */
+void serdev_controller_remove(struct serdev_controller *ctrl)
+{
+	if (!ctrl)
+		return;
+
+	device_for_each_child(&ctrl->dev, NULL, serdev_remove_device);
+	pm_runtime_disable(&ctrl->dev);
+	device_del(&ctrl->dev);
+}
+EXPORT_SYMBOL_GPL(serdev_controller_remove);
+
+/**
+ * __serdev_device_driver_register() - Register client driver with serdev core
+ * @sdrv:	client driver to be associated with client-device.
+ * @owner:	client driver owner to set.
+ *
+ * This API will register the client driver with the serdev framework.
+ * It is typically called from the driver's module-init function.
+ */
+int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
+{
+	sdrv->driver.bus = &serdev_bus_type;
+	sdrv->driver.owner = owner;
+
+	/* force drivers to async probe so I/O is possible in probe */
+        sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
+
+	return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
+
+static void __exit serdev_exit(void)
+{
+	bus_unregister(&serdev_bus_type);
+	ida_destroy(&ctrl_ida);
+}
+module_exit(serdev_exit);
+
+static int __init serdev_init(void)
+{
+	int ret;
+
+	ret = bus_register(&serdev_bus_type);
+	if (ret)
+		return ret;
+
+	is_registered = true;
+	return 0;
+}
+/* Must be before serial drivers register */
+postcore_initcall(serdev_init);
+
+MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Serial attached device bus");
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
new file mode 100644
index 000000000..e3856814c
--- /dev/null
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
+ */
+#include <linux/kernel.h>
+#include <linux/serdev.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/poll.h>
+
+#define SERPORT_ACTIVE		1
+
+struct serport {
+	struct tty_port *port;
+	struct tty_struct *tty;
+	struct tty_driver *tty_drv;
+	int tty_idx;
+	unsigned long flags;
+};
+
+/*
+ * Callback functions from the tty port.
+ */
+
+static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
+				  const u8 *fp, size_t count)
+{
+	struct serdev_controller *ctrl = port->client_data;
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	int ret;
+
+	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
+		return 0;
+
+	ret = serdev_controller_receive_buf(ctrl, cp, count);
+
+	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
+				"receive_buf returns %d (count = %zu)\n",
+				ret, count);
+	if (ret < 0)
+		return 0;
+	else if (ret > count)
+		return count;
+
+	return ret;
+}
+
+static void ttyport_write_wakeup(struct tty_port *port)
+{
+	struct serdev_controller *ctrl = port->client_data;
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty;
+
+	tty = tty_port_tty_get(port);
+	if (!tty)
+		return;
+
+	if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
+	    test_bit(SERPORT_ACTIVE, &serport->flags))
+		serdev_controller_write_wakeup(ctrl);
+
+	/* Wake up any tty_wait_until_sent() */
+	wake_up_interruptible(&tty->write_wait);
+
+	tty_kref_put(tty);
+}
+
+static const struct tty_port_client_operations client_ops = {
+	.receive_buf = ttyport_receive_buf,
+	.write_wakeup = ttyport_write_wakeup,
+};
+
+/*
+ * Callback functions from the serdev core.
+ */
+
+static int ttyport_write_buf(struct serdev_controller *ctrl, const unsigned char *data, size_t len)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
+		return 0;
+
+	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	return tty->ops->write(serport->tty, data, len);
+}
+
+static void ttyport_write_flush(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	tty_driver_flush_buffer(tty);
+}
+
+static int ttyport_write_room(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	return tty_write_room(tty);
+}
+
+static int ttyport_open(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty;
+	struct ktermios ktermios;
+	int ret;
+
+	tty = tty_init_dev(serport->tty_drv, serport->tty_idx);
+	if (IS_ERR(tty))
+		return PTR_ERR(tty);
+	serport->tty = tty;
+
+	if (!tty->ops->open || !tty->ops->close) {
+		ret = -ENODEV;
+		goto err_unlock;
+	}
+
+	ret = tty->ops->open(serport->tty, NULL);
+	if (ret)
+		goto err_close;
+
+	tty_unlock(serport->tty);
+
+	/* Bring the UART into a known 8 bits no parity hw fc state */
+	ktermios = tty->termios;
+	ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP |
+			      INLCR | IGNCR | ICRNL | IXON);
+	ktermios.c_oflag &= ~OPOST;
+	ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+	ktermios.c_cflag &= ~(CSIZE | PARENB);
+	ktermios.c_cflag |= CS8;
+	ktermios.c_cflag |= CRTSCTS;
+	/* Hangups are not supported so make sure to ignore carrier detect. */
+	ktermios.c_cflag |= CLOCAL;
+	tty_set_termios(tty, &ktermios);
+
+	set_bit(SERPORT_ACTIVE, &serport->flags);
+
+	return 0;
+
+err_close:
+	tty->ops->close(tty, NULL);
+err_unlock:
+	tty_unlock(tty);
+	tty_release_struct(tty, serport->tty_idx);
+
+	return ret;
+}
+
+static void ttyport_close(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	clear_bit(SERPORT_ACTIVE, &serport->flags);
+
+	tty_lock(tty);
+	if (tty->ops->close)
+		tty->ops->close(tty, NULL);
+	tty_unlock(tty);
+
+	tty_release_struct(tty, serport->tty_idx);
+}
+
+static unsigned int ttyport_set_baudrate(struct serdev_controller *ctrl, unsigned int speed)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	ktermios.c_cflag &= ~CBAUD;
+	tty_termios_encode_baud_rate(&ktermios, speed, speed);
+
+	/* tty_set_termios() return not checked as it is always 0 */
+	tty_set_termios(tty, &ktermios);
+	return ktermios.c_ospeed;
+}
+
+static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	if (enable)
+		ktermios.c_cflag |= CRTSCTS;
+	else
+		ktermios.c_cflag &= ~CRTSCTS;
+
+	tty_set_termios(tty, &ktermios);
+}
+
+static int ttyport_set_parity(struct serdev_controller *ctrl,
+			      enum serdev_parity parity)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	ktermios.c_cflag &= ~(PARENB | PARODD | CMSPAR);
+	if (parity != SERDEV_PARITY_NONE) {
+		ktermios.c_cflag |= PARENB;
+		if (parity == SERDEV_PARITY_ODD)
+			ktermios.c_cflag |= PARODD;
+	}
+
+	tty_set_termios(tty, &ktermios);
+
+	if ((tty->termios.c_cflag & (PARENB | PARODD | CMSPAR)) !=
+	    (ktermios.c_cflag & (PARENB | PARODD | CMSPAR)))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void ttyport_wait_until_sent(struct serdev_controller *ctrl, long timeout)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	tty_wait_until_sent(tty, timeout);
+}
+
+static int ttyport_get_tiocm(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->tiocmget)
+		return -EOPNOTSUPP;
+
+	return tty->ops->tiocmget(tty);
+}
+
+static int ttyport_set_tiocm(struct serdev_controller *ctrl, unsigned int set, unsigned int clear)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->tiocmset)
+		return -EOPNOTSUPP;
+
+	return tty->ops->tiocmset(tty, set, clear);
+}
+
+static int ttyport_break_ctl(struct serdev_controller *ctrl, unsigned int break_state)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->break_ctl)
+		return -EOPNOTSUPP;
+
+	return tty->ops->break_ctl(tty, break_state);
+}
+
+static const struct serdev_controller_ops ctrl_ops = {
+	.write_buf = ttyport_write_buf,
+	.write_flush = ttyport_write_flush,
+	.write_room = ttyport_write_room,
+	.open = ttyport_open,
+	.close = ttyport_close,
+	.set_flow_control = ttyport_set_flow_control,
+	.set_parity = ttyport_set_parity,
+	.set_baudrate = ttyport_set_baudrate,
+	.wait_until_sent = ttyport_wait_until_sent,
+	.get_tiocm = ttyport_get_tiocm,
+	.set_tiocm = ttyport_set_tiocm,
+	.break_ctl = ttyport_break_ctl,
+};
+
+struct device *serdev_tty_port_register(struct tty_port *port,
+					struct device *parent,
+					struct tty_driver *drv, int idx)
+{
+	struct serdev_controller *ctrl;
+	struct serport *serport;
+	int ret;
+
+	if (!port || !drv || !parent)
+		return ERR_PTR(-ENODEV);
+
+	ctrl = serdev_controller_alloc(parent, sizeof(struct serport));
+	if (!ctrl)
+		return ERR_PTR(-ENOMEM);
+	serport = serdev_controller_get_drvdata(ctrl);
+
+	serport->port = port;
+	serport->tty_idx = idx;
+	serport->tty_drv = drv;
+
+	ctrl->ops = &ctrl_ops;
+
+	port->client_ops = &client_ops;
+	port->client_data = ctrl;
+
+	ret = serdev_controller_add(ctrl);
+	if (ret)
+		goto err_reset_data;
+
+	dev_info(&ctrl->dev, "tty port %s%d registered\n", drv->name, idx);
+	return &ctrl->dev;
+
+err_reset_data:
+	port->client_data = NULL;
+	port->client_ops = &tty_port_default_client_ops;
+	serdev_controller_put(ctrl);
+
+	return ERR_PTR(ret);
+}
+
+int serdev_tty_port_unregister(struct tty_port *port)
+{
+	struct serdev_controller *ctrl = port->client_data;
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+
+	if (!serport)
+		return -ENODEV;
+
+	serdev_controller_remove(ctrl);
+	port->client_data = NULL;
+	port->client_ops = &tty_port_default_client_ops;
+	serdev_controller_put(ctrl);
+
+	return 0;
+}
diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
new file mode 100644
index 000000000..d756fcc88
--- /dev/null
+++ b/drivers/tty/serial/21285.c
@@ -0,0 +1,518 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the serial port on the 21285 StrongArm-110 core logic chip.
+ *
+ * Based on drivers/char/serial.c
+ */
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <asm/mach-types.h>
+#include <asm/system_info.h>
+#include <asm/hardware/dec21285.h>
+#include <mach/hardware.h>
+
+#define BAUD_BASE		(mem_fclk_21285/64)
+
+#define SERIAL_21285_NAME	"ttyFB"
+#define SERIAL_21285_MAJOR	204
+#define SERIAL_21285_MINOR	4
+
+#define RXSTAT_DUMMY_READ	0x80000000
+#define RXSTAT_FRAME		(1 << 0)
+#define RXSTAT_PARITY		(1 << 1)
+#define RXSTAT_OVERRUN		(1 << 2)
+#define RXSTAT_ANYERR		(RXSTAT_FRAME|RXSTAT_PARITY|RXSTAT_OVERRUN)
+
+#define H_UBRLCR_BREAK		(1 << 0)
+#define H_UBRLCR_PARENB		(1 << 1)
+#define H_UBRLCR_PAREVN		(1 << 2)
+#define H_UBRLCR_STOPB		(1 << 3)
+#define H_UBRLCR_FIFO		(1 << 4)
+
+static const char serial21285_name[] = "Footbridge UART";
+
+/*
+ * We only need 2 bits of data, so instead of creating a whole structure for
+ * this, use bits of the private_data pointer of the uart port structure.
+ */
+#define tx_enabled_bit	0
+#define rx_enabled_bit	1
+
+static bool is_enabled(struct uart_port *port, int bit)
+{
+	unsigned long *private_data = (unsigned long *)&port->private_data;
+
+	if (test_bit(bit, private_data))
+		return true;
+	return false;
+}
+
+static void enable(struct uart_port *port, int bit)
+{
+	unsigned long *private_data = (unsigned long *)&port->private_data;
+
+	set_bit(bit, private_data);
+}
+
+static void disable(struct uart_port *port, int bit)
+{
+	unsigned long *private_data = (unsigned long *)&port->private_data;
+
+	clear_bit(bit, private_data);
+}
+
+#define is_tx_enabled(port)	is_enabled(port, tx_enabled_bit)
+#define tx_enable(port)		enable(port, tx_enabled_bit)
+#define tx_disable(port)	disable(port, tx_enabled_bit)
+
+#define is_rx_enabled(port)	is_enabled(port, rx_enabled_bit)
+#define rx_enable(port)		enable(port, rx_enabled_bit)
+#define rx_disable(port)	disable(port, rx_enabled_bit)
+
+/*
+ * The documented expression for selecting the divisor is:
+ *  BAUD_BASE / baud - 1
+ * However, typically BAUD_BASE is not divisible by baud, so
+ * we want to select the divisor that gives us the minimum
+ * error.  Therefore, we want:
+ *  int(BAUD_BASE / baud - 0.5) ->
+ *  int(BAUD_BASE / baud - (baud >> 1) / baud) ->
+ *  int((BAUD_BASE - (baud >> 1)) / baud)
+ */
+
+static void serial21285_stop_tx(struct uart_port *port)
+{
+	if (is_tx_enabled(port)) {
+		disable_irq_nosync(IRQ_CONTX);
+		tx_disable(port);
+	}
+}
+
+static void serial21285_start_tx(struct uart_port *port)
+{
+	if (!is_tx_enabled(port)) {
+		enable_irq(IRQ_CONTX);
+		tx_enable(port);
+	}
+}
+
+static void serial21285_stop_rx(struct uart_port *port)
+{
+	if (is_rx_enabled(port)) {
+		disable_irq_nosync(IRQ_CONRX);
+		rx_disable(port);
+	}
+}
+
+static irqreturn_t serial21285_rx_chars(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned int status, rxs, max_count = 256;
+	u8 ch, flag;
+
+	status = *CSR_UARTFLG;
+	while (!(status & 0x10) && max_count--) {
+		ch = *CSR_UARTDR;
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		rxs = *CSR_RXSTAT | RXSTAT_DUMMY_READ;
+		if (unlikely(rxs & RXSTAT_ANYERR)) {
+			if (rxs & RXSTAT_PARITY)
+				port->icount.parity++;
+			else if (rxs & RXSTAT_FRAME)
+				port->icount.frame++;
+			if (rxs & RXSTAT_OVERRUN)
+				port->icount.overrun++;
+
+			rxs &= port->read_status_mask;
+
+			if (rxs & RXSTAT_PARITY)
+				flag = TTY_PARITY;
+			else if (rxs & RXSTAT_FRAME)
+				flag = TTY_FRAME;
+		}
+
+		uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag);
+
+		status = *CSR_UARTFLG;
+	}
+	tty_flip_buffer_push(&port->state->port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t serial21285_tx_chars(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	u8 ch;
+
+	uart_port_tx_limited(port, ch, 256,
+		!(*CSR_UARTFLG & 0x20),
+		*CSR_UARTDR = ch,
+		({}));
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int serial21285_tx_empty(struct uart_port *port)
+{
+	return (*CSR_UARTFLG & 8) ? 0 : TIOCSER_TEMT;
+}
+
+/* no modem control lines */
+static unsigned int serial21285_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void serial21285_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void serial21285_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+	unsigned int h_lcr;
+
+	spin_lock_irqsave(&port->lock, flags);
+	h_lcr = *CSR_H_UBRLCR;
+	if (break_state)
+		h_lcr |= H_UBRLCR_BREAK;
+	else
+		h_lcr &= ~H_UBRLCR_BREAK;
+	*CSR_H_UBRLCR = h_lcr;
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int serial21285_startup(struct uart_port *port)
+{
+	int ret;
+
+	tx_enable(port);
+	rx_enable(port);
+
+	ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0,
+			  serial21285_name, port);
+	if (ret == 0) {
+		ret = request_irq(IRQ_CONTX, serial21285_tx_chars, 0,
+				  serial21285_name, port);
+		if (ret)
+			free_irq(IRQ_CONRX, port);
+	}
+
+	return ret;
+}
+
+static void serial21285_shutdown(struct uart_port *port)
+{
+	free_irq(IRQ_CONTX, port);
+	free_irq(IRQ_CONRX, port);
+}
+
+static void
+serial21285_set_termios(struct uart_port *port, struct ktermios *termios,
+			const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, quot, h_lcr, b;
+
+	/*
+	 * We don't support modem control lines.
+	 */
+	termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
+	termios->c_cflag |= CLOCAL;
+
+	/*
+	 * We don't support BREAK character recognition.
+	 */
+	termios->c_iflag &= ~(IGNBRK | BRKINT);
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
+	quot = uart_get_divisor(port, baud);
+	b = port->uartclk / (16 * quot);
+	tty_termios_encode_baud_rate(termios, b, b);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		h_lcr = 0x00;
+		break;
+	case CS6:
+		h_lcr = 0x20;
+		break;
+	case CS7:
+		h_lcr = 0x40;
+		break;
+	default: /* CS8 */
+		h_lcr = 0x60;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		h_lcr |= H_UBRLCR_STOPB;
+	if (termios->c_cflag & PARENB) {
+		h_lcr |= H_UBRLCR_PARENB;
+		if (!(termios->c_cflag & PARODD))
+			h_lcr |= H_UBRLCR_PAREVN;
+	}
+
+	if (port->fifosize)
+		h_lcr |= H_UBRLCR_FIFO;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * Which character status flags are we interested in?
+	 */
+	port->read_status_mask = RXSTAT_OVERRUN;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY;
+
+	/*
+	 * Which character status flags should we ignore?
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY;
+	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= RXSTAT_OVERRUN;
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
+
+	quot -= 1;
+
+	*CSR_UARTCON = 0;
+	*CSR_L_UBRLCR = quot & 0xff;
+	*CSR_M_UBRLCR = (quot >> 8) & 0x0f;
+	*CSR_H_UBRLCR = h_lcr;
+	*CSR_UARTCON = 1;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *serial21285_type(struct uart_port *port)
+{
+	return port->type == PORT_21285 ? "DC21285" : NULL;
+}
+
+static void serial21285_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, 32);
+}
+
+static int serial21285_request_port(struct uart_port *port)
+{
+	return request_mem_region(port->mapbase, 32, serial21285_name)
+			 != NULL ? 0 : -EBUSY;
+}
+
+static void serial21285_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE && serial21285_request_port(port) == 0)
+		port->type = PORT_21285;
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int serial21285_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_21285)
+		ret = -EINVAL;
+	if (ser->irq <= 0)
+		ret = -EINVAL;
+	if (ser->baud_base != port->uartclk / 16)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops serial21285_ops = {
+	.tx_empty	= serial21285_tx_empty,
+	.get_mctrl	= serial21285_get_mctrl,
+	.set_mctrl	= serial21285_set_mctrl,
+	.stop_tx	= serial21285_stop_tx,
+	.start_tx	= serial21285_start_tx,
+	.stop_rx	= serial21285_stop_rx,
+	.break_ctl	= serial21285_break_ctl,
+	.startup	= serial21285_startup,
+	.shutdown	= serial21285_shutdown,
+	.set_termios	= serial21285_set_termios,
+	.type		= serial21285_type,
+	.release_port	= serial21285_release_port,
+	.request_port	= serial21285_request_port,
+	.config_port	= serial21285_config_port,
+	.verify_port	= serial21285_verify_port,
+};
+
+static struct uart_port serial21285_port = {
+	.mapbase	= 0x42000160,
+	.iotype		= UPIO_MEM,
+	.irq		= 0,
+	.fifosize	= 16,
+	.ops		= &serial21285_ops,
+	.flags		= UPF_BOOT_AUTOCONF,
+};
+
+static void serial21285_setup_ports(void)
+{
+	serial21285_port.uartclk = mem_fclk_21285 / 4;
+}
+
+#ifdef CONFIG_SERIAL_21285_CONSOLE
+static void serial21285_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (*CSR_UARTFLG & 0x20)
+		barrier();
+	*CSR_UARTDR = ch;
+}
+
+static void
+serial21285_console_write(struct console *co, const char *s,
+			  unsigned int count)
+{
+	uart_console_write(&serial21285_port, s, count, serial21285_console_putchar);
+}
+
+static void __init
+serial21285_get_options(struct uart_port *port, int *baud,
+			int *parity, int *bits)
+{
+	if (*CSR_UARTCON == 1) {
+		unsigned int tmp;
+
+		tmp = *CSR_H_UBRLCR;
+		switch (tmp & 0x60) {
+		case 0x00:
+			*bits = 5;
+			break;
+		case 0x20:
+			*bits = 6;
+			break;
+		case 0x40:
+			*bits = 7;
+			break;
+		default:
+		case 0x60:
+			*bits = 8;
+			break;
+		}
+
+		if (tmp & H_UBRLCR_PARENB) {
+			*parity = 'o';
+			if (tmp & H_UBRLCR_PAREVN)
+				*parity = 'e';
+		}
+
+		tmp = *CSR_L_UBRLCR | (*CSR_M_UBRLCR << 8);
+
+		*baud = port->uartclk / (16 * (tmp + 1));
+	}
+}
+
+static int __init serial21285_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port = &serial21285_port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		serial21285_get_options(port, &baud, &parity, &bits);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver serial21285_reg;
+
+static struct console serial21285_console =
+{
+	.name		= SERIAL_21285_NAME,
+	.write		= serial21285_console_write,
+	.device		= uart_console_device,
+	.setup		= serial21285_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial21285_reg,
+};
+
+static int __init rs285_console_init(void)
+{
+	serial21285_setup_ports();
+	register_console(&serial21285_console);
+	return 0;
+}
+console_initcall(rs285_console_init);
+
+#define SERIAL_21285_CONSOLE	&serial21285_console
+#else
+#define SERIAL_21285_CONSOLE	NULL
+#endif
+
+static struct uart_driver serial21285_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "ttyFB",
+	.dev_name		= "ttyFB",
+	.major			= SERIAL_21285_MAJOR,
+	.minor			= SERIAL_21285_MINOR,
+	.nr			= 1,
+	.cons			= SERIAL_21285_CONSOLE,
+};
+
+static int __init serial21285_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Serial: 21285 driver\n");
+
+	serial21285_setup_ports();
+
+	ret = uart_register_driver(&serial21285_reg);
+	if (ret == 0)
+		uart_add_one_port(&serial21285_reg, &serial21285_port);
+
+	return ret;
+}
+
+static void __exit serial21285_exit(void)
+{
+	uart_remove_one_port(&serial21285_reg, &serial21285_port);
+	uart_unregister_driver(&serial21285_reg);
+}
+
+module_init(serial21285_init);
+module_exit(serial21285_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel Footbridge (21285) serial driver");
+MODULE_ALIAS_CHARDEV(SERIAL_21285_MAJOR, SERIAL_21285_MINOR);
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
new file mode 100644
index 000000000..1aa3e55c8
--- /dev/null
+++ b/drivers/tty/serial/8250/8250.h
@@ -0,0 +1,422 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  Driver for 8250/16550-type serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright (C) 2001 Russell King.
+ */
+
+#include <linux/bits.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/dmaengine.h>
+
+#include "../serial_mctrl_gpio.h"
+
+struct uart_8250_dma {
+	int (*tx_dma)(struct uart_8250_port *p);
+	int (*rx_dma)(struct uart_8250_port *p);
+	void (*prepare_tx_dma)(struct uart_8250_port *p);
+	void (*prepare_rx_dma)(struct uart_8250_port *p);
+
+	/* Filter function */
+	dma_filter_fn		fn;
+	/* Parameter to the filter function */
+	void			*rx_param;
+	void			*tx_param;
+
+	struct dma_slave_config	rxconf;
+	struct dma_slave_config	txconf;
+
+	struct dma_chan		*rxchan;
+	struct dma_chan		*txchan;
+
+	/* Device address base for DMA operations */
+	phys_addr_t		rx_dma_addr;
+	phys_addr_t		tx_dma_addr;
+
+	/* DMA address of the buffer in memory */
+	dma_addr_t		rx_addr;
+	dma_addr_t		tx_addr;
+
+	dma_cookie_t		rx_cookie;
+	dma_cookie_t		tx_cookie;
+
+	void			*rx_buf;
+
+	size_t			rx_size;
+	size_t			tx_size;
+
+	unsigned char		tx_running;
+	unsigned char		tx_err;
+	unsigned char		rx_running;
+};
+
+struct old_serial_port {
+	unsigned int uart;
+	unsigned int baud_base;
+	unsigned int port;
+	unsigned int irq;
+	upf_t        flags;
+	unsigned char io_type;
+	unsigned char __iomem *iomem_base;
+	unsigned short iomem_reg_shift;
+};
+
+struct serial8250_config {
+	const char	*name;
+	unsigned short	fifo_size;
+	unsigned short	tx_loadsz;
+	unsigned char	fcr;
+	unsigned char	rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
+	unsigned int	flags;
+};
+
+#define UART_CAP_FIFO	BIT(8)	/* UART has FIFO */
+#define UART_CAP_EFR	BIT(9)	/* UART has EFR */
+#define UART_CAP_SLEEP	BIT(10)	/* UART has IER sleep */
+#define UART_CAP_AFE	BIT(11)	/* MCR-based hw flow control */
+#define UART_CAP_UUE	BIT(12)	/* UART needs IER bit 6 set (Xscale) */
+#define UART_CAP_RTOIE	BIT(13)	/* UART needs IER bit 4 set (Xscale, Tegra) */
+#define UART_CAP_HFIFO	BIT(14)	/* UART has a "hidden" FIFO */
+#define UART_CAP_RPM	BIT(15)	/* Runtime PM is active while idle */
+#define UART_CAP_IRDA	BIT(16)	/* UART supports IrDA line discipline */
+#define UART_CAP_MINI	BIT(17)	/* Mini UART on BCM283X family lacks:
+					 * STOP PARITY EPAR SPAR WLEN5 WLEN6
+					 */
+#define UART_CAP_NOTEMT	BIT(18)	/* UART without interrupt on TEMT available */
+
+#define UART_BUG_QUOT	BIT(0)	/* UART has buggy quot LSB */
+#define UART_BUG_TXEN	BIT(1)	/* UART has buggy TX IIR status */
+#define UART_BUG_NOMSR	BIT(2)	/* UART has buggy MSR status bits (Au1x00) */
+#define UART_BUG_THRE	BIT(3)	/* UART has buggy THRE reassertion */
+#define UART_BUG_TXRACE	BIT(5)	/* UART Tx fails to set remote DR */
+
+
+#ifdef CONFIG_SERIAL_8250_SHARE_IRQ
+#define SERIAL8250_SHARE_IRQS 1
+#else
+#define SERIAL8250_SHARE_IRQS 0
+#endif
+
+#define SERIAL8250_PORT_FLAGS(_base, _irq, _flags)		\
+	{							\
+		.iobase		= _base,			\
+		.irq		= _irq,				\
+		.uartclk	= 1843200,			\
+		.iotype		= UPIO_PORT,			\
+		.flags		= UPF_BOOT_AUTOCONF | (_flags),	\
+	}
+
+#define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
+
+
+static inline int serial_in(struct uart_8250_port *up, int offset)
+{
+	return up->port.serial_in(&up->port, offset);
+}
+
+static inline void serial_out(struct uart_8250_port *up, int offset, int value)
+{
+	up->port.serial_out(&up->port, offset, value);
+}
+
+/**
+ *	serial_lsr_in - Read LSR register and preserve flags across reads
+ *	@up:	uart 8250 port
+ *
+ *	Read LSR register and handle saving non-preserved flags across reads.
+ *	The flags that are not preserved across reads are stored into
+ *	up->lsr_saved_flags.
+ *
+ *	Returns LSR value or'ed with the preserved flags (if any).
+ */
+static inline u16 serial_lsr_in(struct uart_8250_port *up)
+{
+	u16 lsr = up->lsr_saved_flags;
+
+	lsr |= serial_in(up, UART_LSR);
+	up->lsr_saved_flags = lsr & up->lsr_save_mask;
+
+	return lsr;
+}
+
+/*
+ * For the 16C950
+ */
+static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
+{
+	serial_out(up, UART_SCR, offset);
+	serial_out(up, UART_ICR, value);
+}
+
+static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
+						   int offset)
+{
+	unsigned int value;
+
+	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
+	serial_out(up, UART_SCR, offset);
+	value = serial_in(up, UART_ICR);
+	serial_icr_write(up, UART_ACR, up->acr);
+
+	return value;
+}
+
+void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
+
+static inline u32 serial_dl_read(struct uart_8250_port *up)
+{
+	return up->dl_read(up);
+}
+
+static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
+{
+	up->dl_write(up, value);
+}
+
+static inline bool serial8250_set_THRI(struct uart_8250_port *up)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	if (up->ier & UART_IER_THRI)
+		return false;
+	up->ier |= UART_IER_THRI;
+	serial_out(up, UART_IER, up->ier);
+	return true;
+}
+
+static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	if (!(up->ier & UART_IER_THRI))
+		return false;
+	up->ier &= ~UART_IER_THRI;
+	serial_out(up, UART_IER, up->ier);
+	return true;
+}
+
+struct uart_8250_port *serial8250_get_port(int line);
+
+void serial8250_rpm_get(struct uart_8250_port *p);
+void serial8250_rpm_put(struct uart_8250_port *p);
+
+void serial8250_rpm_get_tx(struct uart_8250_port *p);
+void serial8250_rpm_put_tx(struct uart_8250_port *p);
+
+int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
+			    struct serial_rs485 *rs485);
+void serial8250_em485_start_tx(struct uart_8250_port *p);
+void serial8250_em485_stop_tx(struct uart_8250_port *p);
+void serial8250_em485_destroy(struct uart_8250_port *p);
+extern struct serial_rs485 serial8250_em485_supported;
+
+/* MCR <-> TIOCM conversion */
+static inline int serial8250_TIOCM_to_MCR(int tiocm)
+{
+	int mcr = 0;
+
+	if (tiocm & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (tiocm & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (tiocm & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (tiocm & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (tiocm & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	return mcr;
+}
+
+static inline int serial8250_MCR_to_TIOCM(int mcr)
+{
+	int tiocm = 0;
+
+	if (mcr & UART_MCR_RTS)
+		tiocm |= TIOCM_RTS;
+	if (mcr & UART_MCR_DTR)
+		tiocm |= TIOCM_DTR;
+	if (mcr & UART_MCR_OUT1)
+		tiocm |= TIOCM_OUT1;
+	if (mcr & UART_MCR_OUT2)
+		tiocm |= TIOCM_OUT2;
+	if (mcr & UART_MCR_LOOP)
+		tiocm |= TIOCM_LOOP;
+
+	return tiocm;
+}
+
+/* MSR <-> TIOCM conversion */
+static inline int serial8250_MSR_to_TIOCM(int msr)
+{
+	int tiocm = 0;
+
+	if (msr & UART_MSR_DCD)
+		tiocm |= TIOCM_CAR;
+	if (msr & UART_MSR_RI)
+		tiocm |= TIOCM_RNG;
+	if (msr & UART_MSR_DSR)
+		tiocm |= TIOCM_DSR;
+	if (msr & UART_MSR_CTS)
+		tiocm |= TIOCM_CTS;
+
+	return tiocm;
+}
+
+static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
+{
+	serial_out(up, UART_MCR, value);
+
+	if (up->gpios)
+		mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
+}
+
+static inline int serial8250_in_MCR(struct uart_8250_port *up)
+{
+	int mctrl;
+
+	mctrl = serial_in(up, UART_MCR);
+
+	if (up->gpios) {
+		unsigned int mctrl_gpio = 0;
+
+		mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
+		mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
+	}
+
+	return mctrl;
+}
+
+bool alpha_jensen(void);
+void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl);
+
+#ifdef CONFIG_SERIAL_8250_PNP
+int serial8250_pnp_init(void);
+void serial8250_pnp_exit(void);
+#else
+static inline int serial8250_pnp_init(void) { return 0; }
+static inline void serial8250_pnp_exit(void) { }
+#endif
+
+#ifdef CONFIG_SERIAL_8250_FINTEK
+int fintek_8250_probe(struct uart_8250_port *uart);
+#else
+static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
+#endif
+
+#ifdef CONFIG_ARCH_OMAP1
+#include <linux/soc/ti/omap1-soc.h>
+static inline int is_omap1_8250(struct uart_8250_port *pt)
+{
+	int res;
+
+	switch (pt->port.mapbase) {
+	case OMAP1_UART1_BASE:
+	case OMAP1_UART2_BASE:
+	case OMAP1_UART3_BASE:
+		res = 1;
+		break;
+	default:
+		res = 0;
+		break;
+	}
+
+	return res;
+}
+
+static inline int is_omap1510_8250(struct uart_8250_port *pt)
+{
+	if (!cpu_is_omap1510())
+		return 0;
+
+	return is_omap1_8250(pt);
+}
+#else
+static inline int is_omap1_8250(struct uart_8250_port *pt)
+{
+	return 0;
+}
+static inline int is_omap1510_8250(struct uart_8250_port *pt)
+{
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_SERIAL_8250_DMA
+extern int serial8250_tx_dma(struct uart_8250_port *);
+extern int serial8250_rx_dma(struct uart_8250_port *);
+extern void serial8250_rx_dma_flush(struct uart_8250_port *);
+extern int serial8250_request_dma(struct uart_8250_port *);
+extern void serial8250_release_dma(struct uart_8250_port *);
+
+static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	if (dma->prepare_tx_dma)
+		dma->prepare_tx_dma(p);
+}
+
+static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	if (dma->prepare_rx_dma)
+		dma->prepare_rx_dma(p);
+}
+
+static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	return dma && dma->tx_running;
+}
+#else
+static inline int serial8250_tx_dma(struct uart_8250_port *p)
+{
+	return -1;
+}
+static inline int serial8250_rx_dma(struct uart_8250_port *p)
+{
+	return -1;
+}
+static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
+static inline int serial8250_request_dma(struct uart_8250_port *p)
+{
+	return -1;
+}
+static inline void serial8250_release_dma(struct uart_8250_port *p) { }
+
+static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
+{
+	return false;
+}
+#endif
+
+static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
+{
+	unsigned char status;
+
+	status = serial_in(up, 0x04); /* EXCR2 */
+#define PRESL(x) ((x) & 0x30)
+	if (PRESL(status) == 0x10) {
+		/* already in high speed mode */
+		return 0;
+	} else {
+		status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
+		status |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
+		serial_out(up, 0x04, status);
+	}
+	return 1;
+}
+
+static inline int serial_index(struct uart_port *port)
+{
+	return port->minor - 64;
+}
diff --git a/drivers/tty/serial/8250/8250_accent.c b/drivers/tty/serial/8250/8250_accent.c
new file mode 100644
index 000000000..1691f1a57
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_accent.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2005 Russell King.
+ *  Data taken from include/asm-i386/serial.h
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+static struct plat_serial8250_port accent_data[] = {
+	SERIAL8250_PORT(0x330, 4),
+	SERIAL8250_PORT(0x338, 4),
+	{ },
+};
+
+static struct platform_device accent_device = {
+	.name			= "serial8250",
+	.id			= PLAT8250_DEV_ACCENT,
+	.dev			= {
+		.platform_data	= accent_data,
+	},
+};
+
+static int __init accent_init(void)
+{
+	return platform_device_register(&accent_device);
+}
+
+module_init(accent_init);
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("8250 serial probe module for Accent Async cards");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_acorn.c b/drivers/tty/serial/8250/8250_acorn.c
new file mode 100644
index 000000000..758c4aa20
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_acorn.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/drivers/serial/acorn.c
+ *
+ *  Copyright (C) 1996-2003 Russell King.
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/tty.h>
+#include <linux/serial_core.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/init.h>
+
+#include <asm/io.h>
+#include <asm/ecard.h>
+#include <asm/string.h>
+
+#include "8250.h"
+
+#define MAX_PORTS	3
+
+struct serial_card_type {
+	unsigned int	num_ports;
+	unsigned int	uartclk;
+	unsigned int	type;
+	unsigned int	offset[MAX_PORTS];
+};
+
+struct serial_card_info {
+	unsigned int	num_ports;
+	int		ports[MAX_PORTS];
+	void __iomem *vaddr;
+};
+
+static int
+serial_card_probe(struct expansion_card *ec, const struct ecard_id *id)
+{
+	struct serial_card_info *info;
+	struct serial_card_type *type = id->data;
+	struct uart_8250_port uart;
+	unsigned long bus_addr;
+	unsigned int i;
+
+	info = kzalloc(sizeof(struct serial_card_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->num_ports = type->num_ports;
+
+	bus_addr = ecard_resource_start(ec, type->type);
+	info->vaddr = ecardm_iomap(ec, type->type, 0, 0);
+	if (!info->vaddr) {
+		kfree(info);
+		return -ENOMEM;
+	}
+
+	ecard_set_drvdata(ec, info);
+
+	memset(&uart, 0, sizeof(struct uart_8250_port));
+	uart.port.irq	= ec->irq;
+	uart.port.flags	= UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ;
+	uart.port.uartclk	= type->uartclk;
+	uart.port.iotype	= UPIO_MEM;
+	uart.port.regshift	= 2;
+	uart.port.dev	= &ec->dev;
+
+	for (i = 0; i < info->num_ports; i++) {
+		uart.port.membase = info->vaddr + type->offset[i];
+		uart.port.mapbase = bus_addr + type->offset[i];
+
+		info->ports[i] = serial8250_register_8250_port(&uart);
+	}
+
+	return 0;
+}
+
+static void serial_card_remove(struct expansion_card *ec)
+{
+	struct serial_card_info *info = ecard_get_drvdata(ec);
+	int i;
+
+	ecard_set_drvdata(ec, NULL);
+
+	for (i = 0; i < info->num_ports; i++)
+		if (info->ports[i] > 0)
+			serial8250_unregister_port(info->ports[i]);
+
+	kfree(info);
+}
+
+static struct serial_card_type atomwide_type = {
+	.num_ports	= 3,
+	.uartclk	= 7372800,
+	.type		= ECARD_RES_IOCSLOW,
+	.offset		= { 0x2800, 0x2400, 0x2000 },
+};
+
+static struct serial_card_type serport_type = {
+	.num_ports	= 2,
+	.uartclk	= 3686400,
+	.type		= ECARD_RES_IOCSLOW,
+	.offset		= { 0x2000, 0x2020 },
+};
+
+static const struct ecard_id serial_cids[] = {
+	{ MANU_ATOMWIDE,	PROD_ATOMWIDE_3PSERIAL,	&atomwide_type	},
+	{ MANU_SERPORT,		PROD_SERPORT_DSPORT,	&serport_type	},
+	{ 0xffff, 0xffff }
+};
+
+static struct ecard_driver serial_card_driver = {
+	.probe		= serial_card_probe,
+	.remove		= serial_card_remove,
+	.id_table	= serial_cids,
+	.drv = {
+		.name	= "8250_acorn",
+	},
+};
+
+static int __init serial_card_init(void)
+{
+	return ecard_register_driver(&serial_card_driver);
+}
+
+static void __exit serial_card_exit(void)
+{
+	ecard_remove_driver(&serial_card_driver);
+}
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("Acorn 8250-compatible serial port expansion card driver");
+MODULE_LICENSE("GPL");
+
+module_init(serial_card_init);
+module_exit(serial_card_exit);
diff --git a/drivers/tty/serial/8250/8250_alpha.c b/drivers/tty/serial/8250/8250_alpha.c
new file mode 100644
index 000000000..58e70328a
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_alpha.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <asm/machvec.h>
+#include "8250.h"
+
+bool alpha_jensen(void)
+{
+	return !strcmp(alpha_mv.vector_name, "Jensen");
+}
+
+void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/*
+	 * Digital did something really horribly wrong with the OUT1 and OUT2
+	 * lines on Alpha Jensen.  The failure mode is that if either is
+	 * cleared, the machine locks up with endless interrupts.
+	 */
+	mctrl |= TIOCM_OUT1 | TIOCM_OUT2;
+
+	serial8250_do_set_mctrl(port, mctrl);
+}
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
new file mode 100644
index 000000000..4a9e71b2d
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -0,0 +1,607 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Serial Port driver for Aspeed VUART device
+ *
+ *    Copyright (C) 2016 Jeremy Kerr <jk@ozlabs.org>, IBM Corp.
+ *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
+ */
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/clk.h>
+
+#include "8250.h"
+
+#define ASPEED_VUART_GCRA		0x20
+#define ASPEED_VUART_GCRA_VUART_EN		BIT(0)
+#define ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY	BIT(1)
+#define ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD BIT(5)
+#define ASPEED_VUART_GCRB		0x24
+#define ASPEED_VUART_GCRB_HOST_SIRQ_MASK	GENMASK(7, 4)
+#define ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT	4
+#define ASPEED_VUART_ADDRL		0x28
+#define ASPEED_VUART_ADDRH		0x2c
+
+#define ASPEED_VUART_DEFAULT_LPC_ADDR	0x3f8
+#define ASPEED_VUART_DEFAULT_SIRQ	4
+#define ASPEED_VUART_DEFAULT_SIRQ_POLARITY	IRQ_TYPE_LEVEL_LOW
+
+struct aspeed_vuart {
+	struct device		*dev;
+	struct clk		*clk;
+	int			line;
+	struct timer_list	unthrottle_timer;
+	struct uart_8250_port	*port;
+};
+
+/*
+ * If we fill the tty flip buffers, we throttle the data ready interrupt
+ * to prevent dropped characters. This timeout defines how long we wait
+ * to (conditionally, depending on buffer state) unthrottle.
+ */
+static const int unthrottle_timeout = HZ/10;
+
+/*
+ * The VUART is basically two UART 'front ends' connected by their FIFO
+ * (no actual serial line in between). One is on the BMC side (management
+ * controller) and one is on the host CPU side.
+ *
+ * It allows the BMC to provide to the host a "UART" that pipes into
+ * the BMC itself and can then be turned by the BMC into a network console
+ * of some sort for example.
+ *
+ * This driver is for the BMC side. The sysfs files allow the BMC
+ * userspace which owns the system configuration policy, to specify
+ * at what IO port and interrupt number the host side will appear
+ * to the host on the Host <-> BMC LPC bus. It could be different on a
+ * different system (though most of them use 3f8/4).
+ */
+
+static inline u8 aspeed_vuart_readb(struct aspeed_vuart *vuart, u8 reg)
+{
+	return readb(vuart->port->port.membase + reg);
+}
+
+static inline void aspeed_vuart_writeb(struct aspeed_vuart *vuart, u8 val, u8 reg)
+{
+	writeb(val, vuart->port->port.membase + reg);
+}
+
+static ssize_t lpc_address_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	u16 addr;
+
+	addr = (aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRH) << 8) |
+		(aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRL));
+
+	return sysfs_emit(buf, "0x%x\n", addr);
+}
+
+static int aspeed_vuart_set_lpc_address(struct aspeed_vuart *vuart, u32 addr)
+{
+	if (addr > U16_MAX)
+		return -EINVAL;
+
+	aspeed_vuart_writeb(vuart, addr >> 8, ASPEED_VUART_ADDRH);
+	aspeed_vuart_writeb(vuart, addr >> 0, ASPEED_VUART_ADDRL);
+
+	return 0;
+}
+
+static ssize_t lpc_address_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	u32 val;
+	int err;
+
+	err = kstrtou32(buf, 0, &val);
+	if (err)
+		return err;
+
+	err = aspeed_vuart_set_lpc_address(vuart, val);
+	return err ? : count;
+}
+
+static DEVICE_ATTR_RW(lpc_address);
+
+static ssize_t sirq_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	u8 reg;
+
+	reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRB);
+	reg &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
+	reg >>= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT;
+
+	return sysfs_emit(buf, "%u\n", reg);
+}
+
+static int aspeed_vuart_set_sirq(struct aspeed_vuart *vuart, u32 sirq)
+{
+	u8 reg;
+
+	if (sirq > (ASPEED_VUART_GCRB_HOST_SIRQ_MASK >> ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT))
+		return -EINVAL;
+
+	sirq <<= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT;
+	sirq &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
+
+	reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRB);
+	reg &= ~ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
+	reg |= sirq;
+	aspeed_vuart_writeb(vuart, reg, ASPEED_VUART_GCRB);
+
+	return 0;
+}
+
+static ssize_t sirq_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	unsigned long val;
+	int err;
+
+	err = kstrtoul(buf, 0, &val);
+	if (err)
+		return err;
+
+	err = aspeed_vuart_set_sirq(vuart, val);
+	return err ? : count;
+}
+
+static DEVICE_ATTR_RW(sirq);
+
+static ssize_t sirq_polarity_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	u8 reg;
+
+	reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRA);
+	reg &= ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY;
+
+	return sysfs_emit(buf, "%u\n", reg ? 1 : 0);
+}
+
+static void aspeed_vuart_set_sirq_polarity(struct aspeed_vuart *vuart,
+					   bool polarity)
+{
+	u8 reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRA);
+
+	if (polarity)
+		reg |= ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY;
+	else
+		reg &= ~ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY;
+
+	aspeed_vuart_writeb(vuart, reg, ASPEED_VUART_GCRA);
+}
+
+static ssize_t sirq_polarity_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	unsigned long val;
+	int err;
+
+	err = kstrtoul(buf, 0, &val);
+	if (err)
+		return err;
+
+	aspeed_vuart_set_sirq_polarity(vuart, val != 0);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(sirq_polarity);
+
+static struct attribute *aspeed_vuart_attrs[] = {
+	&dev_attr_sirq.attr,
+	&dev_attr_sirq_polarity.attr,
+	&dev_attr_lpc_address.attr,
+	NULL,
+};
+
+static const struct attribute_group aspeed_vuart_attr_group = {
+	.attrs = aspeed_vuart_attrs,
+};
+
+static void aspeed_vuart_set_enabled(struct aspeed_vuart *vuart, bool enabled)
+{
+	u8 reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRA);
+
+	if (enabled)
+		reg |= ASPEED_VUART_GCRA_VUART_EN;
+	else
+		reg &= ~ASPEED_VUART_GCRA_VUART_EN;
+
+	aspeed_vuart_writeb(vuart, reg, ASPEED_VUART_GCRA);
+}
+
+static void aspeed_vuart_set_host_tx_discard(struct aspeed_vuart *vuart,
+					     bool discard)
+{
+	u8 reg;
+
+	reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRA);
+
+	/* If the DISABLE_HOST_TX_DISCARD bit is set, discard is disabled */
+	if (!discard)
+		reg |= ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD;
+	else
+		reg &= ~ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD;
+
+	aspeed_vuart_writeb(vuart, reg, ASPEED_VUART_GCRA);
+}
+
+static int aspeed_vuart_startup(struct uart_port *uart_port)
+{
+	struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port);
+	struct aspeed_vuart *vuart = uart_8250_port->port.private_data;
+	int rc;
+
+	rc = serial8250_do_startup(uart_port);
+	if (rc)
+		return rc;
+
+	aspeed_vuart_set_host_tx_discard(vuart, false);
+
+	return 0;
+}
+
+static void aspeed_vuart_shutdown(struct uart_port *uart_port)
+{
+	struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port);
+	struct aspeed_vuart *vuart = uart_8250_port->port.private_data;
+
+	aspeed_vuart_set_host_tx_discard(vuart, true);
+
+	serial8250_do_shutdown(uart_port);
+}
+
+static void __aspeed_vuart_set_throttle(struct uart_8250_port *up,
+		bool throttle)
+{
+	unsigned char irqs = UART_IER_RLSI | UART_IER_RDI;
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	up->ier &= ~irqs;
+	if (!throttle)
+		up->ier |= irqs;
+	serial_out(up, UART_IER, up->ier);
+}
+static void aspeed_vuart_set_throttle(struct uart_port *port, bool throttle)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	__aspeed_vuart_set_throttle(up, throttle);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void aspeed_vuart_throttle(struct uart_port *port)
+{
+	aspeed_vuart_set_throttle(port, true);
+}
+
+static void aspeed_vuart_unthrottle(struct uart_port *port)
+{
+	aspeed_vuart_set_throttle(port, false);
+}
+
+static void aspeed_vuart_unthrottle_exp(struct timer_list *timer)
+{
+	struct aspeed_vuart *vuart = from_timer(vuart, timer, unthrottle_timer);
+	struct uart_8250_port *up = vuart->port;
+
+	if (!tty_buffer_space_avail(&up->port.state->port)) {
+		mod_timer(&vuart->unthrottle_timer,
+			  jiffies + unthrottle_timeout);
+		return;
+	}
+
+	aspeed_vuart_unthrottle(&up->port);
+}
+
+/*
+ * Custom interrupt handler to manage finer-grained flow control. Although we
+ * have throttle/unthrottle callbacks, we've seen that the VUART device can
+ * deliver characters faster than the ldisc has a chance to check buffer space
+ * against the throttle threshold. This results in dropped characters before
+ * the throttle.
+ *
+ * We do this by checking for flip buffer space before RX. If we have no space,
+ * throttle now and schedule an unthrottle for later, once the ldisc has had
+ * a chance to drain the buffers.
+ */
+static int aspeed_vuart_handle_irq(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int iir, lsr;
+	unsigned long flags;
+	unsigned int space, count;
+
+	iir = serial_port_in(port, UART_IIR);
+
+	if (iir & UART_IIR_NO_INT)
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	lsr = serial_port_in(port, UART_LSR);
+
+	if (lsr & (UART_LSR_DR | UART_LSR_BI)) {
+		space = tty_buffer_space_avail(&port->state->port);
+
+		if (!space) {
+			/* throttle and schedule an unthrottle later */
+			struct aspeed_vuart *vuart = port->private_data;
+			__aspeed_vuart_set_throttle(up, true);
+
+			if (!timer_pending(&vuart->unthrottle_timer))
+				mod_timer(&vuart->unthrottle_timer,
+					  jiffies + unthrottle_timeout);
+
+		} else {
+			count = min(space, 256U);
+
+			do {
+				serial8250_read_char(up, lsr);
+				lsr = serial_in(up, UART_LSR);
+				if (--count == 0)
+					break;
+			} while (lsr & (UART_LSR_DR | UART_LSR_BI));
+
+			tty_flip_buffer_push(&port->state->port);
+		}
+	}
+
+	serial8250_modem_status(up);
+	if (lsr & UART_LSR_THRE)
+		serial8250_tx_chars(up);
+
+	uart_unlock_and_check_sysrq_irqrestore(port, flags);
+
+	return 1;
+}
+
+static void aspeed_vuart_auto_configure_sirq_polarity(
+	struct aspeed_vuart *vuart, struct device_node *syscon_np,
+	u32 reg_offset, u32 reg_mask)
+{
+	struct regmap *regmap;
+	u32 value;
+
+	regmap = syscon_node_to_regmap(syscon_np);
+	if (IS_ERR(regmap)) {
+		dev_warn(vuart->dev,
+			 "could not get regmap for aspeed,sirq-polarity-sense\n");
+		return;
+	}
+	if (regmap_read(regmap, reg_offset, &value)) {
+		dev_warn(vuart->dev, "could not read hw strap table\n");
+		return;
+	}
+
+	aspeed_vuart_set_sirq_polarity(vuart, (value & reg_mask) == 0);
+}
+
+static int aspeed_vuart_map_irq_polarity(u32 dt)
+{
+	switch (dt) {
+	case IRQ_TYPE_LEVEL_LOW:
+		return 0;
+	case IRQ_TYPE_LEVEL_HIGH:
+		return 1;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int aspeed_vuart_probe(struct platform_device *pdev)
+{
+	struct of_phandle_args sirq_polarity_sense_args;
+	struct uart_8250_port port;
+	struct aspeed_vuart *vuart;
+	struct device_node *np;
+	struct resource *res;
+	u32 clk, prop, sirq[2];
+	int rc, sirq_polarity;
+
+	np = pdev->dev.of_node;
+
+	vuart = devm_kzalloc(&pdev->dev, sizeof(*vuart), GFP_KERNEL);
+	if (!vuart)
+		return -ENOMEM;
+
+	vuart->dev = &pdev->dev;
+	timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	memset(&port, 0, sizeof(port));
+	port.port.private_data = vuart;
+	port.port.mapbase = res->start;
+	port.port.mapsize = resource_size(res);
+	port.port.startup = aspeed_vuart_startup;
+	port.port.shutdown = aspeed_vuart_shutdown;
+	port.port.throttle = aspeed_vuart_throttle;
+	port.port.unthrottle = aspeed_vuart_unthrottle;
+	port.port.status = UPSTAT_SYNC_FIFO;
+	port.port.dev = &pdev->dev;
+	port.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+	port.bugs |= UART_BUG_TXRACE;
+
+	rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
+	if (rc < 0)
+		return rc;
+
+	if (of_property_read_u32(np, "clock-frequency", &clk)) {
+		vuart->clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(vuart->clk)) {
+			dev_warn(&pdev->dev,
+				"clk or clock-frequency not defined\n");
+			rc = PTR_ERR(vuart->clk);
+			goto err_sysfs_remove;
+		}
+
+		rc = clk_prepare_enable(vuart->clk);
+		if (rc < 0)
+			goto err_sysfs_remove;
+
+		clk = clk_get_rate(vuart->clk);
+	}
+
+	/* If current-speed was set, then try not to change it. */
+	if (of_property_read_u32(np, "current-speed", &prop) == 0)
+		port.port.custom_divisor = clk / (16 * prop);
+
+	/* Check for shifted address mapping */
+	if (of_property_read_u32(np, "reg-offset", &prop) == 0)
+		port.port.mapbase += prop;
+
+	/* Check for registers offset within the devices address range */
+	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
+		port.port.regshift = prop;
+
+	/* Check for fifo size */
+	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
+		port.port.fifosize = prop;
+
+	/* Check for a fixed line number */
+	rc = of_alias_get_id(np, "serial");
+	if (rc >= 0)
+		port.port.line = rc;
+
+	port.port.irq = irq_of_parse_and_map(np, 0);
+	port.port.handle_irq = aspeed_vuart_handle_irq;
+	port.port.iotype = UPIO_MEM;
+	port.port.type = PORT_ASPEED_VUART;
+	port.port.uartclk = clk;
+	port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
+		| UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST;
+
+	if (of_property_read_bool(np, "no-loopback-test"))
+		port.port.flags |= UPF_SKIP_TEST;
+
+	if (port.port.fifosize)
+		port.capabilities = UART_CAP_FIFO;
+
+	if (of_property_read_bool(np, "auto-flow-control"))
+		port.capabilities |= UART_CAP_AFE;
+
+	rc = serial8250_register_8250_port(&port);
+	if (rc < 0)
+		goto err_clk_disable;
+
+	vuart->line = rc;
+	vuart->port = serial8250_get_port(vuart->line);
+
+	rc = of_parse_phandle_with_fixed_args(
+		np, "aspeed,sirq-polarity-sense", 2, 0,
+		&sirq_polarity_sense_args);
+	if (rc < 0) {
+		dev_dbg(&pdev->dev,
+			"aspeed,sirq-polarity-sense property not found\n");
+	} else {
+		aspeed_vuart_auto_configure_sirq_polarity(
+			vuart, sirq_polarity_sense_args.np,
+			sirq_polarity_sense_args.args[0],
+			BIT(sirq_polarity_sense_args.args[1]));
+		of_node_put(sirq_polarity_sense_args.np);
+	}
+
+	rc = of_property_read_u32(np, "aspeed,lpc-io-reg", &prop);
+	if (rc < 0)
+		prop = ASPEED_VUART_DEFAULT_LPC_ADDR;
+
+	rc = aspeed_vuart_set_lpc_address(vuart, prop);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "invalid value in aspeed,lpc-io-reg property\n");
+		goto err_clk_disable;
+	}
+
+	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", sirq, 2);
+	if (rc < 0) {
+		sirq[0] = ASPEED_VUART_DEFAULT_SIRQ;
+		sirq[1] = ASPEED_VUART_DEFAULT_SIRQ_POLARITY;
+	}
+
+	rc = aspeed_vuart_set_sirq(vuart, sirq[0]);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "invalid sirq number in aspeed,lpc-interrupts property\n");
+		goto err_clk_disable;
+	}
+
+	sirq_polarity = aspeed_vuart_map_irq_polarity(sirq[1]);
+	if (sirq_polarity < 0) {
+		dev_err(&pdev->dev, "invalid sirq polarity in aspeed,lpc-interrupts property\n");
+		rc = sirq_polarity;
+		goto err_clk_disable;
+	}
+
+	aspeed_vuart_set_sirq_polarity(vuart, sirq_polarity);
+
+	aspeed_vuart_set_enabled(vuart, true);
+	aspeed_vuart_set_host_tx_discard(vuart, true);
+	platform_set_drvdata(pdev, vuart);
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(vuart->clk);
+	irq_dispose_mapping(port.port.irq);
+err_sysfs_remove:
+	sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
+	return rc;
+}
+
+static int aspeed_vuart_remove(struct platform_device *pdev)
+{
+	struct aspeed_vuart *vuart = platform_get_drvdata(pdev);
+
+	del_timer_sync(&vuart->unthrottle_timer);
+	aspeed_vuart_set_enabled(vuart, false);
+	serial8250_unregister_port(vuart->line);
+	sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
+	clk_disable_unprepare(vuart->clk);
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_vuart_table[] = {
+	{ .compatible = "aspeed,ast2400-vuart" },
+	{ .compatible = "aspeed,ast2500-vuart" },
+	{ },
+};
+
+static struct platform_driver aspeed_vuart_driver = {
+	.driver = {
+		.name = "aspeed-vuart",
+		.of_match_table = aspeed_vuart_table,
+	},
+	.probe = aspeed_vuart_probe,
+	.remove = aspeed_vuart_remove,
+};
+
+module_platform_driver(aspeed_vuart_driver);
+
+MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Driver for Aspeed VUART device");
diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c
new file mode 100644
index 000000000..4f4502fb5
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Serial port driver for BCM2835AUX UART
+ *
+ * Copyright (C) 2016 Martin Sperl <kernel@martin.sperl.org>
+ *
+ * Based on 8250_lpc18xx.c:
+ * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * The bcm2835aux is capable of RTS auto flow-control, but this driver doesn't
+ * take advantage of it yet.  When adding support, be sure not to enable it
+ * simultaneously to rs485.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#include "8250.h"
+
+#define BCM2835_AUX_UART_CNTL		8
+#define BCM2835_AUX_UART_CNTL_RXEN	0x01 /* Receiver enable */
+#define BCM2835_AUX_UART_CNTL_TXEN	0x02 /* Transmitter enable */
+#define BCM2835_AUX_UART_CNTL_AUTORTS	0x04 /* RTS set by RX fill level */
+#define BCM2835_AUX_UART_CNTL_AUTOCTS	0x08 /* CTS stops transmitter */
+#define BCM2835_AUX_UART_CNTL_RTS3	0x00 /* RTS set until 3 chars left */
+#define BCM2835_AUX_UART_CNTL_RTS2	0x10 /* RTS set until 2 chars left */
+#define BCM2835_AUX_UART_CNTL_RTS1	0x20 /* RTS set until 1 chars left */
+#define BCM2835_AUX_UART_CNTL_RTS4	0x30 /* RTS set until 4 chars left */
+#define BCM2835_AUX_UART_CNTL_RTSINV	0x40 /* Invert auto RTS polarity */
+#define BCM2835_AUX_UART_CNTL_CTSINV	0x80 /* Invert auto CTS polarity */
+
+/**
+ * struct bcm2835aux_data - driver private data of BCM2835 auxiliary UART
+ * @clk: clock producer of the port's uartclk
+ * @line: index of the port's serial8250_ports[] entry
+ * @cntl: cached copy of CNTL register
+ */
+struct bcm2835aux_data {
+	struct clk *clk;
+	int line;
+	u32 cntl;
+};
+
+struct bcm2835_aux_serial_driver_data {
+	resource_size_t offset;
+};
+
+static void bcm2835aux_rs485_start_tx(struct uart_8250_port *up)
+{
+	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
+		struct bcm2835aux_data *data = dev_get_drvdata(up->port.dev);
+
+		data->cntl &= ~BCM2835_AUX_UART_CNTL_RXEN;
+		serial_out(up, BCM2835_AUX_UART_CNTL, data->cntl);
+	}
+
+	/*
+	 * On the bcm2835aux, the MCR register contains no other
+	 * flags besides RTS.  So no need for a read-modify-write.
+	 */
+	if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND)
+		serial8250_out_MCR(up, 0);
+	else
+		serial8250_out_MCR(up, UART_MCR_RTS);
+}
+
+static void bcm2835aux_rs485_stop_tx(struct uart_8250_port *up)
+{
+	if (up->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
+		serial8250_out_MCR(up, 0);
+	else
+		serial8250_out_MCR(up, UART_MCR_RTS);
+
+	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
+		struct bcm2835aux_data *data = dev_get_drvdata(up->port.dev);
+
+		data->cntl |= BCM2835_AUX_UART_CNTL_RXEN;
+		serial_out(up, BCM2835_AUX_UART_CNTL, data->cntl);
+	}
+}
+
+static int bcm2835aux_serial_probe(struct platform_device *pdev)
+{
+	const struct bcm2835_aux_serial_driver_data *bcm_data;
+	struct uart_8250_port up = { };
+	struct bcm2835aux_data *data;
+	resource_size_t offset = 0;
+	struct resource *res;
+	unsigned int uartclk;
+	int ret;
+
+	/* allocate the custom structure */
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* initialize data */
+	up.capabilities = UART_CAP_FIFO | UART_CAP_MINI;
+	up.port.dev = &pdev->dev;
+	up.port.regshift = 2;
+	up.port.type = PORT_16550;
+	up.port.iotype = UPIO_MEM;
+	up.port.fifosize = 8;
+	up.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE |
+			UPF_SKIP_TEST | UPF_IOREMAP;
+	up.port.rs485_config = serial8250_em485_config;
+	up.port.rs485_supported = serial8250_em485_supported;
+	up.rs485_start_tx = bcm2835aux_rs485_start_tx;
+	up.rs485_stop_tx = bcm2835aux_rs485_stop_tx;
+
+	/* initialize cached copy with power-on reset value */
+	data->cntl = BCM2835_AUX_UART_CNTL_RXEN | BCM2835_AUX_UART_CNTL_TXEN;
+
+	platform_set_drvdata(pdev, data);
+
+	/* get the clock - this also enables the HW */
+	data->clk = devm_clk_get_optional(&pdev->dev, NULL);
+	if (IS_ERR(data->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(data->clk), "could not get clk\n");
+
+	/* get the interrupt */
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	up.port.irq = ret;
+
+	/* map the main registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "memory resource not found");
+		return -EINVAL;
+	}
+
+	bcm_data = device_get_match_data(&pdev->dev);
+
+	/* Some UEFI implementations (e.g. tianocore/edk2 for the Raspberry Pi)
+	 * describe the miniuart with a base address that encompasses the auxiliary
+	 * registers shared between the miniuart and spi.
+	 *
+	 * This is due to historical reasons, see discussion here :
+	 * https://edk2.groups.io/g/devel/topic/87501357#84349
+	 *
+	 * We need to add the offset between the miniuart and auxiliary
+	 * registers to get the real miniuart base address.
+	 */
+	if (bcm_data)
+		offset = bcm_data->offset;
+
+	up.port.mapbase = res->start + offset;
+	up.port.mapsize = resource_size(res) - offset;
+
+	/* Check for a fixed line number */
+	ret = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (ret >= 0)
+		up.port.line = ret;
+
+	/* enable the clock as a last step */
+	ret = clk_prepare_enable(data->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable uart clock - %d\n",
+			ret);
+		return ret;
+	}
+
+	uartclk = clk_get_rate(data->clk);
+	if (!uartclk) {
+		ret = device_property_read_u32(&pdev->dev, "clock-frequency", &uartclk);
+		if (ret) {
+			dev_err_probe(&pdev->dev, ret, "could not get clk rate\n");
+			goto dis_clk;
+		}
+	}
+
+	/* the HW-clock divider for bcm2835aux is 8,
+	 * but 8250 expects a divider of 16,
+	 * so we have to multiply the actual clock by 2
+	 * to get identical baudrates.
+	 */
+	up.port.uartclk = uartclk * 2;
+
+	/* register the port */
+	ret = serial8250_register_8250_port(&up);
+	if (ret < 0) {
+		dev_err_probe(&pdev->dev, ret, "unable to register 8250 port\n");
+		goto dis_clk;
+	}
+	data->line = ret;
+
+	return 0;
+
+dis_clk:
+	clk_disable_unprepare(data->clk);
+	return ret;
+}
+
+static int bcm2835aux_serial_remove(struct platform_device *pdev)
+{
+	struct bcm2835aux_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+static const struct bcm2835_aux_serial_driver_data bcm2835_acpi_data = {
+	.offset = 0x40,
+};
+
+static const struct of_device_id bcm2835aux_serial_match[] = {
+	{ .compatible = "brcm,bcm2835-aux-uart" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, bcm2835aux_serial_match);
+
+static const struct acpi_device_id bcm2835aux_serial_acpi_match[] = {
+	{ "BCM2836", (kernel_ulong_t)&bcm2835_acpi_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, bcm2835aux_serial_acpi_match);
+
+static struct platform_driver bcm2835aux_serial_driver = {
+	.driver = {
+		.name = "bcm2835-aux-uart",
+		.of_match_table = bcm2835aux_serial_match,
+		.acpi_match_table = bcm2835aux_serial_acpi_match,
+	},
+	.probe  = bcm2835aux_serial_probe,
+	.remove = bcm2835aux_serial_remove,
+};
+module_platform_driver(bcm2835aux_serial_driver);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+static int __init early_bcm2835aux_setup(struct earlycon_device *device,
+					const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+	device->port.regshift = 2;
+
+	return early_serial8250_setup(device, NULL);
+}
+
+OF_EARLYCON_DECLARE(bcm2835aux, "brcm,bcm2835-aux-uart",
+		    early_bcm2835aux_setup);
+#endif
+
+MODULE_DESCRIPTION("BCM2835 auxiliar UART driver");
+MODULE_AUTHOR("Martin Sperl <kernel@martin.sperl.org>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
new file mode 100644
index 000000000..aa5aff046
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -0,0 +1,1247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020, Broadcom */
+/*
+ * 8250-core based driver for Broadcom ns16550a UARTs
+ *
+ * This driver uses the standard 8250 driver core but adds additional
+ * optional features including the ability to use a baud rate clock
+ * mux for more accurate high speed baud rate selection and also
+ * an optional DMA engine.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/dma-mapping.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+
+#include "8250.h"
+
+/* Register definitions for UART DMA block. Version 1.1 or later. */
+#define UDMA_ARB_RX		0x00
+#define UDMA_ARB_TX		0x04
+#define		UDMA_ARB_REQ				0x00000001
+#define		UDMA_ARB_GRANT				0x00000002
+
+#define UDMA_RX_REVISION	0x00
+#define UDMA_RX_REVISION_REQUIRED			0x00000101
+#define UDMA_RX_CTRL		0x04
+#define		UDMA_RX_CTRL_BUF_CLOSE_MODE		0x00010000
+#define		UDMA_RX_CTRL_MASK_WR_DONE		0x00008000
+#define		UDMA_RX_CTRL_ENDIAN_OVERRIDE		0x00004000
+#define		UDMA_RX_CTRL_ENDIAN			0x00002000
+#define		UDMA_RX_CTRL_OE_IS_ERR			0x00001000
+#define		UDMA_RX_CTRL_PE_IS_ERR			0x00000800
+#define		UDMA_RX_CTRL_FE_IS_ERR			0x00000400
+#define		UDMA_RX_CTRL_NUM_BUF_USED_MASK		0x000003c0
+#define		UDMA_RX_CTRL_NUM_BUF_USED_SHIFT	6
+#define		UDMA_RX_CTRL_BUF_CLOSE_CLK_SEL_SYS	0x00000020
+#define		UDMA_RX_CTRL_BUF_CLOSE_ENA		0x00000010
+#define		UDMA_RX_CTRL_TIMEOUT_CLK_SEL_SYS	0x00000008
+#define		UDMA_RX_CTRL_TIMEOUT_ENA		0x00000004
+#define		UDMA_RX_CTRL_ABORT			0x00000002
+#define		UDMA_RX_CTRL_ENA			0x00000001
+#define UDMA_RX_STATUS		0x08
+#define		UDMA_RX_STATUS_ACTIVE_BUF_MASK		0x0000000f
+#define UDMA_RX_TRANSFER_LEN	0x0c
+#define UDMA_RX_TRANSFER_TOTAL	0x10
+#define UDMA_RX_BUFFER_SIZE	0x14
+#define UDMA_RX_SRC_ADDR	0x18
+#define UDMA_RX_TIMEOUT		0x1c
+#define UDMA_RX_BUFFER_CLOSE	0x20
+#define UDMA_RX_BLOCKOUT_COUNTER 0x24
+#define UDMA_RX_BUF0_PTR_LO	0x28
+#define UDMA_RX_BUF0_PTR_HI	0x2c
+#define UDMA_RX_BUF0_STATUS	0x30
+#define		UDMA_RX_BUFX_STATUS_OVERRUN_ERR		0x00000010
+#define		UDMA_RX_BUFX_STATUS_FRAME_ERR		0x00000008
+#define		UDMA_RX_BUFX_STATUS_PARITY_ERR		0x00000004
+#define		UDMA_RX_BUFX_STATUS_CLOSE_EXPIRED	0x00000002
+#define		UDMA_RX_BUFX_STATUS_DATA_RDY		0x00000001
+#define UDMA_RX_BUF0_DATA_LEN	0x34
+#define UDMA_RX_BUF1_PTR_LO	0x38
+#define UDMA_RX_BUF1_PTR_HI	0x3c
+#define UDMA_RX_BUF1_STATUS	0x40
+#define UDMA_RX_BUF1_DATA_LEN	0x44
+
+#define UDMA_TX_REVISION	0x00
+#define UDMA_TX_REVISION_REQUIRED			0x00000101
+#define UDMA_TX_CTRL		0x04
+#define		UDMA_TX_CTRL_ENDIAN_OVERRIDE		0x00000080
+#define		UDMA_TX_CTRL_ENDIAN			0x00000040
+#define		UDMA_TX_CTRL_NUM_BUF_USED_MASK		0x00000030
+#define		UDMA_TX_CTRL_NUM_BUF_USED_1		0x00000010
+#define		UDMA_TX_CTRL_ABORT			0x00000002
+#define		UDMA_TX_CTRL_ENA			0x00000001
+#define UDMA_TX_DST_ADDR	0x08
+#define UDMA_TX_BLOCKOUT_COUNTER 0x10
+#define UDMA_TX_TRANSFER_LEN	0x14
+#define UDMA_TX_TRANSFER_TOTAL	0x18
+#define UDMA_TX_STATUS		0x20
+#define UDMA_TX_BUF0_PTR_LO	0x24
+#define UDMA_TX_BUF0_PTR_HI	0x28
+#define UDMA_TX_BUF0_STATUS	0x2c
+#define		UDMA_TX_BUFX_LAST			0x00000002
+#define		UDMA_TX_BUFX_EMPTY			0x00000001
+#define UDMA_TX_BUF0_DATA_LEN	0x30
+#define UDMA_TX_BUF0_DATA_SENT	0x34
+#define UDMA_TX_BUF1_PTR_LO	0x38
+
+#define UDMA_INTR_STATUS	0x00
+#define		UDMA_INTR_ARB_TX_GRANT			0x00040000
+#define		UDMA_INTR_ARB_RX_GRANT			0x00020000
+#define		UDMA_INTR_TX_ALL_EMPTY			0x00010000
+#define		UDMA_INTR_TX_EMPTY_BUF1			0x00008000
+#define		UDMA_INTR_TX_EMPTY_BUF0			0x00004000
+#define		UDMA_INTR_TX_ABORT			0x00002000
+#define		UDMA_INTR_TX_DONE			0x00001000
+#define		UDMA_INTR_RX_ERROR			0x00000800
+#define		UDMA_INTR_RX_TIMEOUT			0x00000400
+#define		UDMA_INTR_RX_READY_BUF7			0x00000200
+#define		UDMA_INTR_RX_READY_BUF6			0x00000100
+#define		UDMA_INTR_RX_READY_BUF5			0x00000080
+#define		UDMA_INTR_RX_READY_BUF4			0x00000040
+#define		UDMA_INTR_RX_READY_BUF3			0x00000020
+#define		UDMA_INTR_RX_READY_BUF2			0x00000010
+#define		UDMA_INTR_RX_READY_BUF1			0x00000008
+#define		UDMA_INTR_RX_READY_BUF0			0x00000004
+#define		UDMA_INTR_RX_READY_MASK			0x000003fc
+#define		UDMA_INTR_RX_READY_SHIFT		2
+#define		UDMA_INTR_RX_ABORT			0x00000002
+#define		UDMA_INTR_RX_DONE			0x00000001
+#define UDMA_INTR_SET		0x04
+#define UDMA_INTR_CLEAR		0x08
+#define UDMA_INTR_MASK_STATUS	0x0c
+#define UDMA_INTR_MASK_SET	0x10
+#define UDMA_INTR_MASK_CLEAR	0x14
+
+
+#define UDMA_RX_INTERRUPTS ( \
+	UDMA_INTR_RX_ERROR | \
+	UDMA_INTR_RX_TIMEOUT | \
+	UDMA_INTR_RX_READY_BUF0 | \
+	UDMA_INTR_RX_READY_BUF1 | \
+	UDMA_INTR_RX_READY_BUF2 | \
+	UDMA_INTR_RX_READY_BUF3 | \
+	UDMA_INTR_RX_READY_BUF4 | \
+	UDMA_INTR_RX_READY_BUF5 | \
+	UDMA_INTR_RX_READY_BUF6 | \
+	UDMA_INTR_RX_READY_BUF7 | \
+	UDMA_INTR_RX_ABORT | \
+	UDMA_INTR_RX_DONE)
+
+#define UDMA_RX_ERR_INTERRUPTS ( \
+	UDMA_INTR_RX_ERROR | \
+	UDMA_INTR_RX_TIMEOUT | \
+	UDMA_INTR_RX_ABORT | \
+	UDMA_INTR_RX_DONE)
+
+#define UDMA_TX_INTERRUPTS ( \
+	UDMA_INTR_TX_ABORT | \
+	UDMA_INTR_TX_DONE)
+
+#define UDMA_IS_RX_INTERRUPT(status) ((status) & UDMA_RX_INTERRUPTS)
+#define UDMA_IS_TX_INTERRUPT(status) ((status) & UDMA_TX_INTERRUPTS)
+
+
+/* Current devices have 8 sets of RX buffer registers */
+#define UDMA_RX_BUFS_COUNT	8
+#define UDMA_RX_BUFS_REG_OFFSET (UDMA_RX_BUF1_PTR_LO - UDMA_RX_BUF0_PTR_LO)
+#define UDMA_RX_BUFx_PTR_LO(x)	(UDMA_RX_BUF0_PTR_LO + \
+				 ((x) * UDMA_RX_BUFS_REG_OFFSET))
+#define UDMA_RX_BUFx_PTR_HI(x)	(UDMA_RX_BUF0_PTR_HI + \
+				 ((x) * UDMA_RX_BUFS_REG_OFFSET))
+#define UDMA_RX_BUFx_STATUS(x)	(UDMA_RX_BUF0_STATUS + \
+				 ((x) * UDMA_RX_BUFS_REG_OFFSET))
+#define UDMA_RX_BUFx_DATA_LEN(x) (UDMA_RX_BUF0_DATA_LEN + \
+				  ((x) * UDMA_RX_BUFS_REG_OFFSET))
+
+/* Current devices have 2 sets of TX buffer registers */
+#define UDMA_TX_BUFS_COUNT	2
+#define UDMA_TX_BUFS_REG_OFFSET (UDMA_TX_BUF1_PTR_LO - UDMA_TX_BUF0_PTR_LO)
+#define UDMA_TX_BUFx_PTR_LO(x)	(UDMA_TX_BUF0_PTR_LO + \
+				 ((x) * UDMA_TX_BUFS_REG_OFFSET))
+#define UDMA_TX_BUFx_PTR_HI(x)	(UDMA_TX_BUF0_PTR_HI + \
+				 ((x) * UDMA_TX_BUFS_REG_OFFSET))
+#define UDMA_TX_BUFx_STATUS(x)	(UDMA_TX_BUF0_STATUS + \
+				 ((x) * UDMA_TX_BUFS_REG_OFFSET))
+#define UDMA_TX_BUFx_DATA_LEN(x) (UDMA_TX_BUF0_DATA_LEN + \
+				  ((x) * UDMA_TX_BUFS_REG_OFFSET))
+#define UDMA_TX_BUFx_DATA_SENT(x) (UDMA_TX_BUF0_DATA_SENT + \
+				   ((x) * UDMA_TX_BUFS_REG_OFFSET))
+#define REGS_8250 0
+#define REGS_DMA_RX 1
+#define REGS_DMA_TX 2
+#define REGS_DMA_ISR 3
+#define REGS_DMA_ARB 4
+#define REGS_MAX 5
+
+#define TX_BUF_SIZE 4096
+#define RX_BUF_SIZE 4096
+#define RX_BUFS_COUNT 2
+#define KHZ    1000
+#define MHZ(x) ((x) * KHZ * KHZ)
+
+static const u32 brcmstb_rate_table[] = {
+	MHZ(81),
+	MHZ(108),
+	MHZ(64),		/* Actually 64285715 for some chips */
+	MHZ(48),
+};
+
+static const u32 brcmstb_rate_table_7278[] = {
+	MHZ(81),
+	MHZ(108),
+	0,
+	MHZ(48),
+};
+
+struct brcmuart_priv {
+	int		line;
+	struct clk	*baud_mux_clk;
+	unsigned long	default_mux_rate;
+	u32		real_rates[ARRAY_SIZE(brcmstb_rate_table)];
+	const u32	*rate_table;
+	ktime_t		char_wait;
+	struct uart_port *up;
+	struct hrtimer	hrt;
+	bool		shutdown;
+	bool		dma_enabled;
+	struct uart_8250_dma dma;
+	void __iomem	*regs[REGS_MAX];
+	dma_addr_t	rx_addr;
+	void		*rx_bufs;
+	size_t		rx_size;
+	int		rx_next_buf;
+	dma_addr_t	tx_addr;
+	void		*tx_buf;
+	size_t		tx_size;
+	bool		tx_running;
+	bool		rx_running;
+	struct dentry	*debugfs_dir;
+
+	/* stats exposed through debugfs */
+	u64		dma_rx_partial_buf;
+	u64		dma_rx_full_buf;
+	u32		rx_bad_timeout_late_char;
+	u32		rx_bad_timeout_no_char;
+	u32		rx_missing_close_timeout;
+	u32		rx_err;
+	u32		rx_timeout;
+	u32		rx_abort;
+	u32		saved_mctrl;
+};
+
+static struct dentry *brcmuart_debugfs_root;
+
+/*
+ * Register access routines
+ */
+static u32 udma_readl(struct brcmuart_priv *priv,
+		int reg_type, int offset)
+{
+	return readl(priv->regs[reg_type] + offset);
+}
+
+static void udma_writel(struct brcmuart_priv *priv,
+			int reg_type, int offset, u32 value)
+{
+	writel(value, priv->regs[reg_type] + offset);
+}
+
+static void udma_set(struct brcmuart_priv *priv,
+		int reg_type, int offset, u32 bits)
+{
+	void __iomem *reg = priv->regs[reg_type] + offset;
+	u32 value;
+
+	value = readl(reg);
+	value |= bits;
+	writel(value, reg);
+}
+
+static void udma_unset(struct brcmuart_priv *priv,
+		int reg_type, int offset, u32 bits)
+{
+	void __iomem *reg = priv->regs[reg_type] + offset;
+	u32 value;
+
+	value = readl(reg);
+	value &= ~bits;
+	writel(value, reg);
+}
+
+/*
+ * The UART DMA engine hardware can be used by multiple UARTS, but
+ * only one at a time. Sharing is not currently supported so
+ * the first UART to request the DMA engine will get it and any
+ * subsequent requests by other UARTS will fail.
+ */
+static int brcmuart_arbitration(struct brcmuart_priv *priv, bool acquire)
+{
+	u32 rx_grant;
+	u32 tx_grant;
+	int waits;
+	int ret = 0;
+
+	if (acquire) {
+		udma_set(priv, REGS_DMA_ARB, UDMA_ARB_RX, UDMA_ARB_REQ);
+		udma_set(priv, REGS_DMA_ARB, UDMA_ARB_TX, UDMA_ARB_REQ);
+
+		waits = 1;
+		while (1) {
+			rx_grant = udma_readl(priv, REGS_DMA_ARB, UDMA_ARB_RX);
+			tx_grant = udma_readl(priv, REGS_DMA_ARB, UDMA_ARB_TX);
+			if (rx_grant & tx_grant & UDMA_ARB_GRANT)
+				return 0;
+			if (waits-- == 0)
+				break;
+			msleep(1);
+		}
+		ret = 1;
+	}
+
+	udma_unset(priv, REGS_DMA_ARB, UDMA_ARB_RX, UDMA_ARB_REQ);
+	udma_unset(priv, REGS_DMA_ARB, UDMA_ARB_TX, UDMA_ARB_REQ);
+	return ret;
+}
+
+static void brcmuart_init_dma_hardware(struct brcmuart_priv *priv)
+{
+	u32 daddr;
+	u32 value;
+	int x;
+
+	/* Start with all interrupts disabled */
+	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_MASK_SET, 0xffffffff);
+
+	udma_writel(priv, REGS_DMA_RX, UDMA_RX_BUFFER_SIZE, RX_BUF_SIZE);
+
+	/*
+	 * Setup buffer close to happen when 32 character times have
+	 * elapsed since the last character was received.
+	 */
+	udma_writel(priv, REGS_DMA_RX, UDMA_RX_BUFFER_CLOSE, 16*10*32);
+	value = (RX_BUFS_COUNT << UDMA_RX_CTRL_NUM_BUF_USED_SHIFT)
+		| UDMA_RX_CTRL_BUF_CLOSE_MODE
+		| UDMA_RX_CTRL_BUF_CLOSE_ENA;
+	udma_writel(priv, REGS_DMA_RX, UDMA_RX_CTRL, value);
+
+	udma_writel(priv, REGS_DMA_RX, UDMA_RX_BLOCKOUT_COUNTER, 0);
+	daddr = priv->rx_addr;
+	for (x = 0; x < RX_BUFS_COUNT; x++) {
+
+		/* Set RX transfer length to 0 for unknown */
+		udma_writel(priv, REGS_DMA_RX, UDMA_RX_TRANSFER_LEN, 0);
+
+		udma_writel(priv, REGS_DMA_RX, UDMA_RX_BUFx_PTR_LO(x),
+			    lower_32_bits(daddr));
+		udma_writel(priv, REGS_DMA_RX, UDMA_RX_BUFx_PTR_HI(x),
+			    upper_32_bits(daddr));
+		daddr += RX_BUF_SIZE;
+	}
+
+	daddr = priv->tx_addr;
+	udma_writel(priv, REGS_DMA_TX, UDMA_TX_BUFx_PTR_LO(0),
+		    lower_32_bits(daddr));
+	udma_writel(priv, REGS_DMA_TX, UDMA_TX_BUFx_PTR_HI(0),
+		    upper_32_bits(daddr));
+	udma_writel(priv, REGS_DMA_TX, UDMA_TX_CTRL,
+		    UDMA_TX_CTRL_NUM_BUF_USED_1);
+
+	/* clear all interrupts then enable them */
+	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_CLEAR, 0xffffffff);
+	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_MASK_CLEAR,
+		UDMA_RX_INTERRUPTS | UDMA_TX_INTERRUPTS);
+
+}
+
+static void start_rx_dma(struct uart_8250_port *p)
+{
+	struct brcmuart_priv *priv = p->port.private_data;
+	int x;
+
+	udma_unset(priv, REGS_DMA_RX, UDMA_RX_CTRL, UDMA_RX_CTRL_ENA);
+
+	/* Clear the RX ready bit for all buffers */
+	for (x = 0; x < RX_BUFS_COUNT; x++)
+		udma_unset(priv, REGS_DMA_RX, UDMA_RX_BUFx_STATUS(x),
+			UDMA_RX_BUFX_STATUS_DATA_RDY);
+
+	/* always start with buffer 0 */
+	udma_unset(priv, REGS_DMA_RX, UDMA_RX_STATUS,
+		   UDMA_RX_STATUS_ACTIVE_BUF_MASK);
+	priv->rx_next_buf = 0;
+
+	udma_set(priv, REGS_DMA_RX, UDMA_RX_CTRL, UDMA_RX_CTRL_ENA);
+	priv->rx_running = true;
+}
+
+static void stop_rx_dma(struct uart_8250_port *p)
+{
+	struct brcmuart_priv *priv = p->port.private_data;
+
+	/* If RX is running, set the RX ABORT */
+	if (priv->rx_running)
+		udma_set(priv, REGS_DMA_RX, UDMA_RX_CTRL, UDMA_RX_CTRL_ABORT);
+}
+
+static int stop_tx_dma(struct uart_8250_port *p)
+{
+	struct brcmuart_priv *priv = p->port.private_data;
+	u32 value;
+
+	/* If TX is running, set the TX ABORT */
+	value = udma_readl(priv, REGS_DMA_TX, UDMA_TX_CTRL);
+	if (value & UDMA_TX_CTRL_ENA)
+		udma_set(priv, REGS_DMA_TX, UDMA_TX_CTRL, UDMA_TX_CTRL_ABORT);
+	priv->tx_running = false;
+	return 0;
+}
+
+/*
+ * NOTE: printk's in this routine will hang the system if this is
+ * the console tty
+ */
+static int brcmuart_tx_dma(struct uart_8250_port *p)
+{
+	struct brcmuart_priv *priv = p->port.private_data;
+	struct circ_buf *xmit = &p->port.state->xmit;
+	u32 tx_size;
+
+	if (uart_tx_stopped(&p->port) || priv->tx_running ||
+		uart_circ_empty(xmit)) {
+		return 0;
+	}
+	tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	priv->dma.tx_err = 0;
+	memcpy(priv->tx_buf, &xmit->buf[xmit->tail], tx_size);
+	uart_xmit_advance(&p->port, tx_size);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&p->port);
+
+	udma_writel(priv, REGS_DMA_TX, UDMA_TX_TRANSFER_LEN, tx_size);
+	udma_writel(priv, REGS_DMA_TX, UDMA_TX_BUF0_DATA_LEN, tx_size);
+	udma_unset(priv, REGS_DMA_TX, UDMA_TX_BUF0_STATUS, UDMA_TX_BUFX_EMPTY);
+	udma_set(priv, REGS_DMA_TX, UDMA_TX_CTRL, UDMA_TX_CTRL_ENA);
+	priv->tx_running = true;
+
+	return 0;
+}
+
+static void brcmuart_rx_buf_done_isr(struct uart_port *up, int index)
+{
+	struct brcmuart_priv *priv = up->private_data;
+	struct tty_port *tty_port = &up->state->port;
+	u32 status;
+	u32 length;
+	u32 copied;
+
+	/* Make sure we're still in sync with the hardware */
+	status = udma_readl(priv, REGS_DMA_RX, UDMA_RX_BUFx_STATUS(index));
+	length = udma_readl(priv, REGS_DMA_RX, UDMA_RX_BUFx_DATA_LEN(index));
+
+	if ((status & UDMA_RX_BUFX_STATUS_DATA_RDY) == 0) {
+		dev_err(up->dev, "RX done interrupt but DATA_RDY not found\n");
+		return;
+	}
+	if (status & (UDMA_RX_BUFX_STATUS_OVERRUN_ERR |
+		      UDMA_RX_BUFX_STATUS_FRAME_ERR |
+		      UDMA_RX_BUFX_STATUS_PARITY_ERR)) {
+		if (status & UDMA_RX_BUFX_STATUS_OVERRUN_ERR) {
+			up->icount.overrun++;
+			dev_warn(up->dev, "RX OVERRUN Error\n");
+		}
+		if (status & UDMA_RX_BUFX_STATUS_FRAME_ERR) {
+			up->icount.frame++;
+			dev_warn(up->dev, "RX FRAMING Error\n");
+		}
+		if (status & UDMA_RX_BUFX_STATUS_PARITY_ERR) {
+			up->icount.parity++;
+			dev_warn(up->dev, "RX PARITY Error\n");
+		}
+	}
+	copied = (u32)tty_insert_flip_string(
+		tty_port,
+		priv->rx_bufs + (index * RX_BUF_SIZE),
+		length);
+	if (copied != length) {
+		dev_warn(up->dev, "Flip buffer overrun of %d bytes\n",
+			 length - copied);
+		up->icount.overrun += length - copied;
+	}
+	up->icount.rx += length;
+	if (status & UDMA_RX_BUFX_STATUS_CLOSE_EXPIRED)
+		priv->dma_rx_partial_buf++;
+	else if (length != RX_BUF_SIZE)
+		/*
+		 * This is a bug in the controller that doesn't cause
+		 * any problems but will be fixed in the future.
+		 */
+		priv->rx_missing_close_timeout++;
+	else
+		priv->dma_rx_full_buf++;
+
+	tty_flip_buffer_push(tty_port);
+}
+
+static void brcmuart_rx_isr(struct uart_port *up, u32 rx_isr)
+{
+	struct brcmuart_priv *priv = up->private_data;
+	struct device *dev = up->dev;
+	u32 rx_done_isr;
+	u32 check_isr;
+
+	rx_done_isr = (rx_isr & UDMA_INTR_RX_READY_MASK);
+	while (rx_done_isr) {
+		check_isr = UDMA_INTR_RX_READY_BUF0 << priv->rx_next_buf;
+		if (check_isr & rx_done_isr) {
+			brcmuart_rx_buf_done_isr(up, priv->rx_next_buf);
+		} else {
+			dev_err(dev,
+				"RX buffer ready out of sequence, restarting RX DMA\n");
+			start_rx_dma(up_to_u8250p(up));
+			break;
+		}
+		if (rx_isr & UDMA_RX_ERR_INTERRUPTS) {
+			if (rx_isr & UDMA_INTR_RX_ERROR)
+				priv->rx_err++;
+			if (rx_isr & UDMA_INTR_RX_TIMEOUT) {
+				priv->rx_timeout++;
+				dev_err(dev, "RX TIMEOUT Error\n");
+			}
+			if (rx_isr & UDMA_INTR_RX_ABORT)
+				priv->rx_abort++;
+			priv->rx_running = false;
+		}
+		/* If not ABORT, re-enable RX buffer */
+		if (!(rx_isr & UDMA_INTR_RX_ABORT))
+			udma_unset(priv, REGS_DMA_RX,
+				   UDMA_RX_BUFx_STATUS(priv->rx_next_buf),
+				   UDMA_RX_BUFX_STATUS_DATA_RDY);
+		rx_done_isr &= ~check_isr;
+		priv->rx_next_buf++;
+		if (priv->rx_next_buf == RX_BUFS_COUNT)
+			priv->rx_next_buf = 0;
+	}
+}
+
+static void brcmuart_tx_isr(struct uart_port *up, u32 isr)
+{
+	struct brcmuart_priv *priv = up->private_data;
+	struct device *dev = up->dev;
+	struct uart_8250_port *port_8250 = up_to_u8250p(up);
+	struct circ_buf	*xmit = &port_8250->port.state->xmit;
+
+	if (isr & UDMA_INTR_TX_ABORT) {
+		if (priv->tx_running)
+			dev_err(dev, "Unexpected TX_ABORT interrupt\n");
+		return;
+	}
+	priv->tx_running = false;
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(up))
+		brcmuart_tx_dma(port_8250);
+}
+
+static irqreturn_t brcmuart_isr(int irq, void *dev_id)
+{
+	struct uart_port *up = dev_id;
+	struct device *dev = up->dev;
+	struct brcmuart_priv *priv = up->private_data;
+	unsigned long flags;
+	u32 interrupts;
+	u32 rval;
+	u32 tval;
+
+	interrupts = udma_readl(priv, REGS_DMA_ISR, UDMA_INTR_STATUS);
+	if (interrupts == 0)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&up->lock, flags);
+
+	/* Clear all interrupts */
+	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_CLEAR, interrupts);
+
+	rval = UDMA_IS_RX_INTERRUPT(interrupts);
+	if (rval)
+		brcmuart_rx_isr(up, rval);
+	tval = UDMA_IS_TX_INTERRUPT(interrupts);
+	if (tval)
+		brcmuart_tx_isr(up, tval);
+	if ((rval | tval) == 0)
+		dev_warn(dev, "Spurious interrupt: 0x%x\n", interrupts);
+
+	spin_unlock_irqrestore(&up->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static int brcmuart_startup(struct uart_port *port)
+{
+	int res;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct brcmuart_priv *priv = up->port.private_data;
+
+	priv->shutdown = false;
+
+	/*
+	 * prevent serial8250_do_startup() from allocating non-existent
+	 * DMA resources
+	 */
+	up->dma = NULL;
+
+	res = serial8250_do_startup(port);
+	if (!priv->dma_enabled)
+		return res;
+	/*
+	 * Disable the Receive Data Interrupt because the DMA engine
+	 * will handle this.
+	 *
+	 * Synchronize UART_IER access against the console.
+	 */
+	spin_lock_irq(&port->lock);
+	up->ier &= ~UART_IER_RDI;
+	serial_port_out(port, UART_IER, up->ier);
+	spin_unlock_irq(&port->lock);
+
+	priv->tx_running = false;
+	priv->dma.rx_dma = NULL;
+	priv->dma.tx_dma = brcmuart_tx_dma;
+	up->dma = &priv->dma;
+
+	brcmuart_init_dma_hardware(priv);
+	start_rx_dma(up);
+	return res;
+}
+
+static void brcmuart_shutdown(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct brcmuart_priv *priv = up->port.private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	priv->shutdown = true;
+	if (priv->dma_enabled) {
+		stop_rx_dma(up);
+		stop_tx_dma(up);
+		/* disable all interrupts */
+		udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_MASK_SET,
+			UDMA_RX_INTERRUPTS | UDMA_TX_INTERRUPTS);
+	}
+
+	/*
+	 * prevent serial8250_do_shutdown() from trying to free
+	 * DMA resources that we never alloc'd for this driver.
+	 */
+	up->dma = NULL;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_do_shutdown(port);
+}
+
+/*
+ * Not all clocks run at the exact specified rate, so set each requested
+ * rate and then get the actual rate.
+ */
+static void init_real_clk_rates(struct device *dev, struct brcmuart_priv *priv)
+{
+	int x;
+	int rc;
+
+	priv->default_mux_rate = clk_get_rate(priv->baud_mux_clk);
+	for (x = 0; x < ARRAY_SIZE(priv->real_rates); x++) {
+		if (priv->rate_table[x] == 0) {
+			priv->real_rates[x] = 0;
+			continue;
+		}
+		rc = clk_set_rate(priv->baud_mux_clk, priv->rate_table[x]);
+		if (rc) {
+			dev_err(dev, "Error selecting BAUD MUX clock for %u\n",
+				priv->rate_table[x]);
+			priv->real_rates[x] = priv->rate_table[x];
+		} else {
+			priv->real_rates[x] = clk_get_rate(priv->baud_mux_clk);
+		}
+	}
+	clk_set_rate(priv->baud_mux_clk, priv->default_mux_rate);
+}
+
+static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
+			u32 baud)
+{
+	u32 percent;
+	u32 best_percent = UINT_MAX;
+	u32 quot;
+	u32 best_quot = 1;
+	u32 rate;
+	int best_index = -1;
+	u64 hires_rate;
+	u64 hires_baud;
+	u64 hires_err;
+	int rc;
+	int i;
+	int real_baud;
+
+	/* If the Baud Mux Clock was not specified, just return */
+	if (priv->baud_mux_clk == NULL)
+		return;
+
+	/* Find the closest match for specified baud */
+	for (i = 0; i < ARRAY_SIZE(priv->real_rates); i++) {
+		if (priv->real_rates[i] == 0)
+			continue;
+		rate = priv->real_rates[i] / 16;
+		quot = DIV_ROUND_CLOSEST(rate, baud);
+		if (!quot)
+			continue;
+
+		/* increase resolution to get xx.xx percent */
+		hires_rate = (u64)rate * 10000;
+		hires_baud = (u64)baud * 10000;
+
+		hires_err = div_u64(hires_rate, (u64)quot);
+
+		/* get the delta */
+		if (hires_err > hires_baud)
+			hires_err = (hires_err - hires_baud);
+		else
+			hires_err = (hires_baud - hires_err);
+
+		percent = (unsigned long)DIV_ROUND_CLOSEST_ULL(hires_err, baud);
+		dev_dbg(up->dev,
+			"Baud rate: %u, MUX Clk: %u, Error: %u.%u%%\n",
+			baud, priv->real_rates[i], percent / 100,
+			percent % 100);
+		if (percent < best_percent) {
+			best_percent = percent;
+			best_index = i;
+			best_quot = quot;
+		}
+	}
+	if (best_index == -1) {
+		dev_err(up->dev, "Error, %d BAUD rate is too fast.\n", baud);
+		return;
+	}
+	rate = priv->real_rates[best_index];
+	rc = clk_set_rate(priv->baud_mux_clk, rate);
+	if (rc)
+		dev_err(up->dev, "Error selecting BAUD MUX clock\n");
+
+	/* Error over 3 percent will cause data errors */
+	if (best_percent > 300)
+		dev_err(up->dev, "Error, baud: %d has %u.%u%% error\n",
+			baud, percent / 100, percent % 100);
+
+	real_baud = rate / 16 / best_quot;
+	dev_dbg(up->dev, "Selecting BAUD MUX rate: %u\n", rate);
+	dev_dbg(up->dev, "Requested baud: %u, Actual baud: %u\n",
+		baud, real_baud);
+
+	/* calc nanoseconds for 1.5 characters time at the given baud rate */
+	i = NSEC_PER_SEC / real_baud / 10;
+	i += (i / 2);
+	priv->char_wait = ns_to_ktime(i);
+
+	up->uartclk = rate;
+}
+
+static void brcmstb_set_termios(struct uart_port *up,
+				struct ktermios *termios,
+				const struct ktermios *old)
+{
+	struct uart_8250_port *p8250 = up_to_u8250p(up);
+	struct brcmuart_priv *priv = up->private_data;
+
+	if (priv->dma_enabled)
+		stop_rx_dma(p8250);
+	set_clock_mux(up, priv, tty_termios_baud_rate(termios));
+	serial8250_do_set_termios(up, termios, old);
+	if (p8250->mcr & UART_MCR_AFE)
+		p8250->port.status |= UPSTAT_AUTOCTS;
+	if (priv->dma_enabled)
+		start_rx_dma(p8250);
+}
+
+static int brcmuart_handle_irq(struct uart_port *p)
+{
+	unsigned int iir = serial_port_in(p, UART_IIR);
+	struct brcmuart_priv *priv = p->private_data;
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int status;
+	unsigned long flags;
+	unsigned int ier;
+	unsigned int mcr;
+	int handled = 0;
+
+	/*
+	 * There's a bug in some 8250 cores where we get a timeout
+	 * interrupt but there is no data ready.
+	 */
+	if (((iir & UART_IIR_ID) == UART_IIR_RX_TIMEOUT) && !(priv->shutdown)) {
+		spin_lock_irqsave(&p->lock, flags);
+		status = serial_port_in(p, UART_LSR);
+		if ((status & UART_LSR_DR) == 0) {
+
+			ier = serial_port_in(p, UART_IER);
+			/*
+			 * if Receive Data Interrupt is enabled and
+			 * we're uing hardware flow control, deassert
+			 * RTS and wait for any chars in the pipline to
+			 * arrive and then check for DR again.
+			 */
+			if ((ier & UART_IER_RDI) && (up->mcr & UART_MCR_AFE)) {
+				ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+				serial_port_out(p, UART_IER, ier);
+				mcr = serial_port_in(p, UART_MCR);
+				mcr &= ~UART_MCR_RTS;
+				serial_port_out(p, UART_MCR, mcr);
+				hrtimer_start(&priv->hrt, priv->char_wait,
+					      HRTIMER_MODE_REL);
+			} else {
+				serial_port_in(p, UART_RX);
+			}
+
+			handled = 1;
+		}
+		spin_unlock_irqrestore(&p->lock, flags);
+		if (handled)
+			return 1;
+	}
+	return serial8250_handle_irq(p, iir);
+}
+
+static enum hrtimer_restart brcmuart_hrtimer_func(struct hrtimer *t)
+{
+	struct brcmuart_priv *priv = container_of(t, struct brcmuart_priv, hrt);
+	struct uart_port *p = priv->up;
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int status;
+	unsigned long flags;
+
+	if (priv->shutdown)
+		return HRTIMER_NORESTART;
+
+	spin_lock_irqsave(&p->lock, flags);
+	status = serial_port_in(p, UART_LSR);
+
+	/*
+	 * If a character did not arrive after the timeout, clear the false
+	 * receive timeout.
+	 */
+	if ((status & UART_LSR_DR) == 0) {
+		serial_port_in(p, UART_RX);
+		priv->rx_bad_timeout_no_char++;
+	} else {
+		priv->rx_bad_timeout_late_char++;
+	}
+
+	/* re-enable receive unless upper layer has disabled it */
+	if ((up->ier & (UART_IER_RLSI | UART_IER_RDI)) ==
+	    (UART_IER_RLSI | UART_IER_RDI)) {
+		status = serial_port_in(p, UART_IER);
+		status |= (UART_IER_RLSI | UART_IER_RDI);
+		serial_port_out(p, UART_IER, status);
+		status = serial_port_in(p, UART_MCR);
+		status |= UART_MCR_RTS;
+		serial_port_out(p, UART_MCR, status);
+	}
+	spin_unlock_irqrestore(&p->lock, flags);
+	return HRTIMER_NORESTART;
+}
+
+static const struct of_device_id brcmuart_dt_ids[] = {
+	{
+		.compatible = "brcm,bcm7278-uart",
+		.data = brcmstb_rate_table_7278,
+	},
+	{
+		.compatible = "brcm,bcm7271-uart",
+		.data = brcmstb_rate_table,
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, brcmuart_dt_ids);
+
+static void brcmuart_free_bufs(struct device *dev, struct brcmuart_priv *priv)
+{
+	if (priv->rx_bufs)
+		dma_free_coherent(dev, priv->rx_size, priv->rx_bufs,
+				  priv->rx_addr);
+	if (priv->tx_buf)
+		dma_free_coherent(dev, priv->tx_size, priv->tx_buf,
+				  priv->tx_addr);
+}
+
+static void brcmuart_throttle(struct uart_port *port)
+{
+	struct brcmuart_priv *priv = port->private_data;
+
+	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_MASK_SET, UDMA_RX_INTERRUPTS);
+}
+
+static void brcmuart_unthrottle(struct uart_port *port)
+{
+	struct brcmuart_priv *priv = port->private_data;
+
+	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_MASK_CLEAR,
+		    UDMA_RX_INTERRUPTS);
+}
+
+static int debugfs_stats_show(struct seq_file *s, void *unused)
+{
+	struct brcmuart_priv *priv = s->private;
+
+	seq_printf(s, "rx_err:\t\t\t\t%u\n",
+		   priv->rx_err);
+	seq_printf(s, "rx_timeout:\t\t\t%u\n",
+		   priv->rx_timeout);
+	seq_printf(s, "rx_abort:\t\t\t%u\n",
+		   priv->rx_abort);
+	seq_printf(s, "rx_bad_timeout_late_char:\t%u\n",
+		   priv->rx_bad_timeout_late_char);
+	seq_printf(s, "rx_bad_timeout_no_char:\t\t%u\n",
+		   priv->rx_bad_timeout_no_char);
+	seq_printf(s, "rx_missing_close_timeout:\t%u\n",
+		   priv->rx_missing_close_timeout);
+	if (priv->dma_enabled) {
+		seq_printf(s, "dma_rx_partial_buf:\t\t%llu\n",
+			   priv->dma_rx_partial_buf);
+		seq_printf(s, "dma_rx_full_buf:\t\t%llu\n",
+			   priv->dma_rx_full_buf);
+	}
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(debugfs_stats);
+
+static void brcmuart_init_debugfs(struct brcmuart_priv *priv,
+				  const char *device)
+{
+	priv->debugfs_dir = debugfs_create_dir(device, brcmuart_debugfs_root);
+	debugfs_create_file("stats", 0444, priv->debugfs_dir, priv,
+			    &debugfs_stats_fops);
+}
+
+
+static int brcmuart_probe(struct platform_device *pdev)
+{
+	struct resource *regs;
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *of_id = NULL;
+	struct uart_8250_port *new_port;
+	struct device *dev = &pdev->dev;
+	struct brcmuart_priv *priv;
+	struct clk *baud_mux_clk;
+	struct uart_8250_port up;
+	int irq;
+	void __iomem *membase = NULL;
+	resource_size_t mapbase = 0;
+	u32 clk_rate = 0;
+	int ret;
+	int x;
+	int dma_irq;
+	static const char * const reg_names[REGS_MAX] = {
+		"uart", "dma_rx", "dma_tx", "dma_intr2", "dma_arb"
+	};
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	priv = devm_kzalloc(dev, sizeof(struct brcmuart_priv),
+			GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	of_id = of_match_node(brcmuart_dt_ids, np);
+	if (!of_id || !of_id->data)
+		priv->rate_table = brcmstb_rate_table;
+	else
+		priv->rate_table = of_id->data;
+
+	for (x = 0; x < REGS_MAX; x++) {
+		regs = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						reg_names[x]);
+		if (!regs)
+			break;
+		priv->regs[x] =	devm_ioremap(dev, regs->start,
+					     resource_size(regs));
+		if (!priv->regs[x])
+			return -ENOMEM;
+		if (x == REGS_8250) {
+			mapbase = regs->start;
+			membase = priv->regs[x];
+		}
+	}
+
+	/* We should have just the uart base registers or all the registers */
+	if (x != 1 && x != REGS_MAX) {
+		dev_warn(dev, "%s registers not specified\n", reg_names[x]);
+		return -EINVAL;
+	}
+
+	/* if the DMA registers were specified, try to enable DMA */
+	if (x > REGS_DMA_RX) {
+		if (brcmuart_arbitration(priv, 1) == 0) {
+			u32 txrev = 0;
+			u32 rxrev = 0;
+
+			txrev = udma_readl(priv, REGS_DMA_RX, UDMA_RX_REVISION);
+			rxrev = udma_readl(priv, REGS_DMA_TX, UDMA_TX_REVISION);
+			if ((txrev >= UDMA_TX_REVISION_REQUIRED) &&
+				(rxrev >= UDMA_RX_REVISION_REQUIRED)) {
+
+				/* Enable the use of the DMA hardware */
+				priv->dma_enabled = true;
+			} else {
+				brcmuart_arbitration(priv, 0);
+				dev_err(dev,
+					"Unsupported DMA Hardware Revision\n");
+			}
+		} else {
+			dev_err(dev,
+				"Timeout arbitrating for UART DMA hardware\n");
+		}
+	}
+
+	of_property_read_u32(np, "clock-frequency", &clk_rate);
+
+	/* See if a Baud clock has been specified */
+	baud_mux_clk = devm_clk_get(dev, "sw_baud");
+	if (IS_ERR(baud_mux_clk)) {
+		if (PTR_ERR(baud_mux_clk) == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto release_dma;
+		}
+		dev_dbg(dev, "BAUD MUX clock not specified\n");
+	} else {
+		dev_dbg(dev, "BAUD MUX clock found\n");
+		ret = clk_prepare_enable(baud_mux_clk);
+		if (ret)
+			goto release_dma;
+		priv->baud_mux_clk = baud_mux_clk;
+		init_real_clk_rates(dev, priv);
+		clk_rate = priv->default_mux_rate;
+	}
+
+	if (clk_rate == 0) {
+		dev_err(dev, "clock-frequency or clk not defined\n");
+		ret = -EINVAL;
+		goto err_clk_disable;
+	}
+
+	dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not ");
+
+	memset(&up, 0, sizeof(up));
+	up.port.type = PORT_BCM7271;
+	up.port.uartclk = clk_rate;
+	up.port.dev = dev;
+	up.port.mapbase = mapbase;
+	up.port.membase = membase;
+	up.port.irq = irq;
+	up.port.handle_irq = brcmuart_handle_irq;
+	up.port.regshift = 2;
+	up.port.iotype = of_device_is_big_endian(np) ?
+		UPIO_MEM32BE : UPIO_MEM32;
+	up.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
+		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	up.port.dev = dev;
+	up.port.private_data = priv;
+
+	/* Check for a fixed line number */
+	ret = of_alias_get_id(np, "serial");
+	if (ret >= 0)
+		up.port.line = ret;
+
+	/* setup HR timer */
+	hrtimer_init(&priv->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	priv->hrt.function = brcmuart_hrtimer_func;
+
+	up.port.shutdown = brcmuart_shutdown;
+	up.port.startup = brcmuart_startup;
+	up.port.throttle = brcmuart_throttle;
+	up.port.unthrottle = brcmuart_unthrottle;
+	up.port.set_termios = brcmstb_set_termios;
+
+	if (priv->dma_enabled) {
+		priv->rx_size = RX_BUF_SIZE * RX_BUFS_COUNT;
+		priv->rx_bufs = dma_alloc_coherent(dev,
+						   priv->rx_size,
+						   &priv->rx_addr, GFP_KERNEL);
+		if (!priv->rx_bufs) {
+			ret = -ENOMEM;
+			goto err;
+		}
+		priv->tx_size = UART_XMIT_SIZE;
+		priv->tx_buf = dma_alloc_coherent(dev,
+						  priv->tx_size,
+						  &priv->tx_addr, GFP_KERNEL);
+		if (!priv->tx_buf) {
+			ret = -ENOMEM;
+			goto err;
+		}
+	}
+
+	ret = serial8250_register_8250_port(&up);
+	if (ret < 0) {
+		dev_err(dev, "unable to register 8250 port\n");
+		goto err;
+	}
+	priv->line = ret;
+	new_port = serial8250_get_port(ret);
+	priv->up = &new_port->port;
+	if (priv->dma_enabled) {
+		dma_irq = platform_get_irq_byname(pdev,  "dma");
+		if (dma_irq < 0) {
+			ret = dma_irq;
+			dev_err(dev, "no IRQ resource info\n");
+			goto err1;
+		}
+		ret = devm_request_irq(dev, dma_irq, brcmuart_isr,
+				IRQF_SHARED, "uart DMA irq", &new_port->port);
+		if (ret) {
+			dev_err(dev, "unable to register IRQ handler\n");
+			goto err1;
+		}
+	}
+	platform_set_drvdata(pdev, priv);
+	brcmuart_init_debugfs(priv, dev_name(&pdev->dev));
+	return 0;
+
+err1:
+	serial8250_unregister_port(priv->line);
+err:
+	brcmuart_free_bufs(dev, priv);
+err_clk_disable:
+	clk_disable_unprepare(baud_mux_clk);
+release_dma:
+	if (priv->dma_enabled)
+		brcmuart_arbitration(priv, 0);
+	return ret;
+}
+
+static int brcmuart_remove(struct platform_device *pdev)
+{
+	struct brcmuart_priv *priv = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(priv->debugfs_dir);
+	hrtimer_cancel(&priv->hrt);
+	serial8250_unregister_port(priv->line);
+	brcmuart_free_bufs(&pdev->dev, priv);
+	clk_disable_unprepare(priv->baud_mux_clk);
+	if (priv->dma_enabled)
+		brcmuart_arbitration(priv, 0);
+	return 0;
+}
+
+static int __maybe_unused brcmuart_suspend(struct device *dev)
+{
+	struct brcmuart_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+
+	/*
+	 * This will prevent resume from enabling RTS before the
+	 *  baud rate has been restored.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+	priv->saved_mctrl = port->mctrl;
+	port->mctrl &= ~TIOCM_RTS;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	serial8250_suspend_port(priv->line);
+	clk_disable_unprepare(priv->baud_mux_clk);
+
+	return 0;
+}
+
+static int __maybe_unused brcmuart_resume(struct device *dev)
+{
+	struct brcmuart_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	int ret;
+
+	ret = clk_prepare_enable(priv->baud_mux_clk);
+	if (ret)
+		dev_err(dev, "Error enabling BAUD MUX clock\n");
+
+	/*
+	 * The hardware goes back to it's default after suspend
+	 * so get the "clk" back in sync.
+	 */
+	ret = clk_set_rate(priv->baud_mux_clk, priv->default_mux_rate);
+	if (ret)
+		dev_err(dev, "Error restoring default BAUD MUX clock\n");
+	if (priv->dma_enabled) {
+		if (brcmuart_arbitration(priv, 1)) {
+			dev_err(dev, "Timeout arbitrating for DMA hardware on resume\n");
+			return(-EBUSY);
+		}
+		brcmuart_init_dma_hardware(priv);
+		start_rx_dma(serial8250_get_port(priv->line));
+	}
+	serial8250_resume_port(priv->line);
+
+	if (priv->saved_mctrl & TIOCM_RTS) {
+		/* Restore RTS */
+		spin_lock_irqsave(&port->lock, flags);
+		port->mctrl |= TIOCM_RTS;
+		port->ops->set_mctrl(port, port->mctrl);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops brcmuart_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(brcmuart_suspend, brcmuart_resume)
+};
+
+static struct platform_driver brcmuart_platform_driver = {
+	.driver = {
+		.name	= "bcm7271-uart",
+		.pm		= &brcmuart_dev_pm_ops,
+		.of_match_table = brcmuart_dt_ids,
+	},
+	.probe		= brcmuart_probe,
+	.remove		= brcmuart_remove,
+};
+
+static int __init brcmuart_init(void)
+{
+	int ret;
+
+	brcmuart_debugfs_root = debugfs_create_dir(
+		brcmuart_platform_driver.driver.name, NULL);
+	ret = platform_driver_register(&brcmuart_platform_driver);
+	if (ret) {
+		debugfs_remove_recursive(brcmuart_debugfs_root);
+		return ret;
+	}
+
+	return 0;
+}
+module_init(brcmuart_init);
+
+static void __exit brcmuart_deinit(void)
+{
+	platform_driver_unregister(&brcmuart_platform_driver);
+	debugfs_remove_recursive(brcmuart_debugfs_root);
+}
+module_exit(brcmuart_deinit);
+
+MODULE_AUTHOR("Al Cooper");
+MODULE_DESCRIPTION("Broadcom NS16550A compatible serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/8250/8250_boca.c b/drivers/tty/serial/8250/8250_boca.c
new file mode 100644
index 000000000..a9b97c034
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_boca.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2005 Russell King.
+ *  Data taken from include/asm-i386/serial.h
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+static struct plat_serial8250_port boca_data[] = {
+	SERIAL8250_PORT(0x100, 12),
+	SERIAL8250_PORT(0x108, 12),
+	SERIAL8250_PORT(0x110, 12),
+	SERIAL8250_PORT(0x118, 12),
+	SERIAL8250_PORT(0x120, 12),
+	SERIAL8250_PORT(0x128, 12),
+	SERIAL8250_PORT(0x130, 12),
+	SERIAL8250_PORT(0x138, 12),
+	SERIAL8250_PORT(0x140, 12),
+	SERIAL8250_PORT(0x148, 12),
+	SERIAL8250_PORT(0x150, 12),
+	SERIAL8250_PORT(0x158, 12),
+	SERIAL8250_PORT(0x160, 12),
+	SERIAL8250_PORT(0x168, 12),
+	SERIAL8250_PORT(0x170, 12),
+	SERIAL8250_PORT(0x178, 12),
+	{ },
+};
+
+static struct platform_device boca_device = {
+	.name			= "serial8250",
+	.id			= PLAT8250_DEV_BOCA,
+	.dev			= {
+		.platform_data	= boca_data,
+	},
+};
+
+static int __init boca_init(void)
+{
+	return platform_device_register(&boca_device);
+}
+
+module_init(boca_init);
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("8250 serial probe module for Boca cards");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
new file mode 100644
index 000000000..3449f8790
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -0,0 +1,1349 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Universal/legacy driver for 8250/16550-type serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright (C) 2001 Russell King.
+ *
+ *  Supports: ISA-compatible 8250/16550 ports
+ *	      PNP 8250/16550 ports
+ *	      early_serial_setup() ports
+ *	      userspace-configurable "phantom" ports
+ *	      "serial8250" platform devices
+ *	      serial8250_register_8250_port() ports
+ */
+
+#include <linux/acpi.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/tty.h>
+#include <linux/ratelimit.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/nmi.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/string_helpers.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#ifdef CONFIG_SPARC
+#include <linux/sunserialcore.h>
+#endif
+
+#include <asm/irq.h>
+
+#include "8250.h"
+
+/*
+ * Configuration:
+ *   share_irqs - whether we pass IRQF_SHARED to request_irq().  This option
+ *                is unsafe when used on edge-triggered interrupts.
+ */
+static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
+
+static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
+
+static struct uart_driver serial8250_reg;
+
+static unsigned int skip_txen_test; /* force skip of txen test at init time */
+
+#define PASS_LIMIT	512
+
+#include <asm/serial.h>
+/*
+ * SERIAL_PORT_DFNS tells us about built-in ports that have no
+ * standard enumeration mechanism.   Platforms that can find all
+ * serial ports via mechanisms like ACPI or PCI need not supply it.
+ */
+#ifndef SERIAL_PORT_DFNS
+#define SERIAL_PORT_DFNS
+#endif
+
+static const struct old_serial_port old_serial_port[] = {
+	SERIAL_PORT_DFNS /* defined in asm/serial.h */
+};
+
+#define UART_NR	CONFIG_SERIAL_8250_NR_UARTS
+
+#ifdef CONFIG_SERIAL_8250_RSA
+
+#define PORT_RSA_MAX 4
+static unsigned long probe_rsa[PORT_RSA_MAX];
+static unsigned int probe_rsa_count;
+#endif /* CONFIG_SERIAL_8250_RSA  */
+
+struct irq_info {
+	struct			hlist_node node;
+	int			irq;
+	spinlock_t		lock;	/* Protects list not the hash */
+	struct list_head	*head;
+};
+
+#define NR_IRQ_HASH		32	/* Can be adjusted later */
+static struct hlist_head irq_lists[NR_IRQ_HASH];
+static DEFINE_MUTEX(hash_mutex);	/* Used to walk the hash */
+
+/*
+ * This is the serial driver's interrupt routine.
+ *
+ * Arjan thinks the old way was overly complex, so it got simplified.
+ * Alan disagrees, saying that need the complexity to handle the weird
+ * nature of ISA shared interrupts.  (This is a special exception.)
+ *
+ * In order to handle ISA shared interrupts properly, we need to check
+ * that all ports have been serviced, and therefore the ISA interrupt
+ * line has been de-asserted.
+ *
+ * This means we need to loop through all ports. checking that they
+ * don't have an interrupt pending.
+ */
+static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
+{
+	struct irq_info *i = dev_id;
+	struct list_head *l, *end = NULL;
+	int pass_counter = 0, handled = 0;
+
+	pr_debug("%s(%d): start\n", __func__, irq);
+
+	spin_lock(&i->lock);
+
+	l = i->head;
+	do {
+		struct uart_8250_port *up;
+		struct uart_port *port;
+
+		up = list_entry(l, struct uart_8250_port, list);
+		port = &up->port;
+
+		if (port->handle_irq(port)) {
+			handled = 1;
+			end = NULL;
+		} else if (end == NULL)
+			end = l;
+
+		l = l->next;
+
+		if (l == i->head && pass_counter++ > PASS_LIMIT)
+			break;
+	} while (l != end);
+
+	spin_unlock(&i->lock);
+
+	pr_debug("%s(%d): end\n", __func__, irq);
+
+	return IRQ_RETVAL(handled);
+}
+
+/*
+ * To support ISA shared interrupts, we need to have one interrupt
+ * handler that ensures that the IRQ line has been deasserted
+ * before returning.  Failing to do this will result in the IRQ
+ * line being stuck active, and, since ISA irqs are edge triggered,
+ * no more IRQs will be seen.
+ */
+static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
+{
+	spin_lock_irq(&i->lock);
+
+	if (!list_empty(i->head)) {
+		if (i->head == &up->list)
+			i->head = i->head->next;
+		list_del(&up->list);
+	} else {
+		BUG_ON(i->head != &up->list);
+		i->head = NULL;
+	}
+	spin_unlock_irq(&i->lock);
+	/* List empty so throw away the hash node */
+	if (i->head == NULL) {
+		hlist_del(&i->node);
+		kfree(i);
+	}
+}
+
+static int serial_link_irq_chain(struct uart_8250_port *up)
+{
+	struct hlist_head *h;
+	struct irq_info *i;
+	int ret;
+
+	mutex_lock(&hash_mutex);
+
+	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+
+	hlist_for_each_entry(i, h, node)
+		if (i->irq == up->port.irq)
+			break;
+
+	if (i == NULL) {
+		i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
+		if (i == NULL) {
+			mutex_unlock(&hash_mutex);
+			return -ENOMEM;
+		}
+		spin_lock_init(&i->lock);
+		i->irq = up->port.irq;
+		hlist_add_head(&i->node, h);
+	}
+	mutex_unlock(&hash_mutex);
+
+	spin_lock_irq(&i->lock);
+
+	if (i->head) {
+		list_add(&up->list, i->head);
+		spin_unlock_irq(&i->lock);
+
+		ret = 0;
+	} else {
+		INIT_LIST_HEAD(&up->list);
+		i->head = &up->list;
+		spin_unlock_irq(&i->lock);
+		ret = request_irq(up->port.irq, serial8250_interrupt,
+				  up->port.irqflags, up->port.name, i);
+		if (ret < 0)
+			serial_do_unlink(i, up);
+	}
+
+	return ret;
+}
+
+static void serial_unlink_irq_chain(struct uart_8250_port *up)
+{
+	struct irq_info *i;
+	struct hlist_head *h;
+
+	mutex_lock(&hash_mutex);
+
+	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+
+	hlist_for_each_entry(i, h, node)
+		if (i->irq == up->port.irq)
+			break;
+
+	BUG_ON(i == NULL);
+	BUG_ON(i->head == NULL);
+
+	if (list_empty(i->head))
+		free_irq(up->port.irq, i);
+
+	serial_do_unlink(i, up);
+	mutex_unlock(&hash_mutex);
+}
+
+/*
+ * This function is used to handle ports that do not have an
+ * interrupt.  This doesn't work very well for 16450's, but gives
+ * barely passable results for a 16550A.  (Although at the expense
+ * of much CPU overhead).
+ */
+static void serial8250_timeout(struct timer_list *t)
+{
+	struct uart_8250_port *up = from_timer(up, t, timer);
+
+	up->port.handle_irq(&up->port);
+	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
+}
+
+static void serial8250_backup_timeout(struct timer_list *t)
+{
+	struct uart_8250_port *up = from_timer(up, t, timer);
+	unsigned int iir, ier = 0, lsr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Must disable interrupts or else we risk racing with the interrupt
+	 * based handler.
+	 */
+	if (up->port.irq) {
+		ier = serial_in(up, UART_IER);
+		serial_out(up, UART_IER, 0);
+	}
+
+	iir = serial_in(up, UART_IIR);
+
+	/*
+	 * This should be a safe test for anyone who doesn't trust the
+	 * IIR bits on their UART, but it's specifically designed for
+	 * the "Diva" UART used on the management processor on many HP
+	 * ia64 and parisc boxes.
+	 */
+	lsr = serial_lsr_in(up);
+	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
+	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
+	    (lsr & UART_LSR_THRE)) {
+		iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
+		iir |= UART_IIR_THRI;
+	}
+
+	if (!(iir & UART_IIR_NO_INT))
+		serial8250_tx_chars(up);
+
+	if (up->port.irq)
+		serial_out(up, UART_IER, ier);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/* Standard timer interval plus 0.2s to keep the port running */
+	mod_timer(&up->timer,
+		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
+}
+
+static void univ8250_setup_timer(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	/*
+	 * The above check will only give an accurate result the first time
+	 * the port is opened so this value needs to be preserved.
+	 */
+	if (up->bugs & UART_BUG_THRE) {
+		pr_debug("%s - using backup timer\n", port->name);
+
+		up->timer.function = serial8250_backup_timeout;
+		mod_timer(&up->timer, jiffies +
+			  uart_poll_timeout(port) + HZ / 5);
+	}
+
+	/*
+	 * If the "interrupt" for this port doesn't correspond with any
+	 * hardware interrupt, we use a timer-based system.  The original
+	 * driver used to do this with IRQ0.
+	 */
+	if (!port->irq)
+		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
+}
+
+static int univ8250_setup_irq(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	if (port->irq)
+		return serial_link_irq_chain(up);
+
+	return 0;
+}
+
+static void univ8250_release_irq(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	del_timer_sync(&up->timer);
+	up->timer.function = serial8250_timeout;
+	if (port->irq)
+		serial_unlink_irq_chain(up);
+}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+static int serial8250_request_rsa_resource(struct uart_8250_port *up)
+{
+	unsigned long start = UART_RSA_BASE << up->port.regshift;
+	unsigned int size = 8 << up->port.regshift;
+	struct uart_port *port = &up->port;
+	int ret = -EINVAL;
+
+	switch (port->iotype) {
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		start += port->iobase;
+		if (request_region(start, size, "serial-rsa"))
+			ret = 0;
+		else
+			ret = -EBUSY;
+		break;
+	}
+
+	return ret;
+}
+
+static void serial8250_release_rsa_resource(struct uart_8250_port *up)
+{
+	unsigned long offset = UART_RSA_BASE << up->port.regshift;
+	unsigned int size = 8 << up->port.regshift;
+	struct uart_port *port = &up->port;
+
+	switch (port->iotype) {
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		release_region(port->iobase + offset, size);
+		break;
+	}
+}
+#endif
+
+static const struct uart_ops *base_ops;
+static struct uart_ops univ8250_port_ops;
+
+static const struct uart_8250_ops univ8250_driver_ops = {
+	.setup_irq	= univ8250_setup_irq,
+	.release_irq	= univ8250_release_irq,
+	.setup_timer	= univ8250_setup_timer,
+};
+
+static struct uart_8250_port serial8250_ports[UART_NR];
+
+/**
+ * serial8250_get_port - retrieve struct uart_8250_port
+ * @line: serial line number
+ *
+ * This function retrieves struct uart_8250_port for the specific line.
+ * This struct *must* *not* be used to perform a 8250 or serial core operation
+ * which is not accessible otherwise. Its only purpose is to make the struct
+ * accessible to the runtime-pm callbacks for context suspend/restore.
+ * The lock assumption made here is none because runtime-pm suspend/resume
+ * callbacks should not be invoked if there is any operation performed on the
+ * port.
+ */
+struct uart_8250_port *serial8250_get_port(int line)
+{
+	return &serial8250_ports[line];
+}
+EXPORT_SYMBOL_GPL(serial8250_get_port);
+
+static void (*serial8250_isa_config)(int port, struct uart_port *up,
+	u32 *capabilities);
+
+void serial8250_set_isa_configurator(
+	void (*v)(int port, struct uart_port *up, u32 *capabilities))
+{
+	serial8250_isa_config = v;
+}
+EXPORT_SYMBOL(serial8250_set_isa_configurator);
+
+#ifdef CONFIG_SERIAL_8250_RSA
+
+static void univ8250_config_port(struct uart_port *port, int flags)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	up->probe &= ~UART_PROBE_RSA;
+	if (port->type == PORT_RSA) {
+		if (serial8250_request_rsa_resource(up) == 0)
+			up->probe |= UART_PROBE_RSA;
+	} else if (flags & UART_CONFIG_TYPE) {
+		int i;
+
+		for (i = 0; i < probe_rsa_count; i++) {
+			if (probe_rsa[i] == up->port.iobase) {
+				if (serial8250_request_rsa_resource(up) == 0)
+					up->probe |= UART_PROBE_RSA;
+				break;
+			}
+		}
+	}
+
+	base_ops->config_port(port, flags);
+
+	if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA)
+		serial8250_release_rsa_resource(up);
+}
+
+static int univ8250_request_port(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	int ret;
+
+	ret = base_ops->request_port(port);
+	if (ret == 0 && port->type == PORT_RSA) {
+		ret = serial8250_request_rsa_resource(up);
+		if (ret < 0)
+			base_ops->release_port(port);
+	}
+
+	return ret;
+}
+
+static void univ8250_release_port(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	if (port->type == PORT_RSA)
+		serial8250_release_rsa_resource(up);
+	base_ops->release_port(port);
+}
+
+static void univ8250_rsa_support(struct uart_ops *ops)
+{
+	ops->config_port  = univ8250_config_port;
+	ops->request_port = univ8250_request_port;
+	ops->release_port = univ8250_release_port;
+}
+
+#else
+#define univ8250_rsa_support(x)		do { } while (0)
+#endif /* CONFIG_SERIAL_8250_RSA */
+
+static inline void serial8250_apply_quirks(struct uart_8250_port *up)
+{
+	up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0;
+}
+
+static struct uart_8250_port *serial8250_setup_port(int index)
+{
+	struct uart_8250_port *up;
+
+	if (index >= UART_NR)
+		return NULL;
+
+	up = &serial8250_ports[index];
+	up->port.line = index;
+	up->port.port_id = index;
+
+	serial8250_init_port(up);
+	if (!base_ops)
+		base_ops = up->port.ops;
+	up->port.ops = &univ8250_port_ops;
+
+	timer_setup(&up->timer, serial8250_timeout, 0);
+
+	up->ops = &univ8250_driver_ops;
+
+	if (IS_ENABLED(CONFIG_ALPHA_JENSEN) ||
+	    (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen()))
+		up->port.set_mctrl = alpha_jensen_set_mctrl;
+
+	serial8250_set_defaults(up);
+
+	return up;
+}
+
+static void __init serial8250_isa_init_ports(void)
+{
+	struct uart_8250_port *up;
+	static int first = 1;
+	int i, irqflag = 0;
+
+	if (!first)
+		return;
+	first = 0;
+
+	if (nr_uarts > UART_NR)
+		nr_uarts = UART_NR;
+
+	/*
+	 * Set up initial isa ports based on nr_uart module param, or else
+	 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not
+	 * need to increase nr_uarts when setting up the initial isa ports.
+	 */
+	for (i = 0; i < nr_uarts; i++)
+		serial8250_setup_port(i);
+
+	/* chain base port ops to support Remote Supervisor Adapter */
+	univ8250_port_ops = *base_ops;
+	univ8250_rsa_support(&univ8250_port_ops);
+
+	if (share_irqs)
+		irqflag = IRQF_SHARED;
+
+	for (i = 0, up = serial8250_ports;
+	     i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
+	     i++, up++) {
+		struct uart_port *port = &up->port;
+
+		port->iobase   = old_serial_port[i].port;
+		port->irq      = irq_canonicalize(old_serial_port[i].irq);
+		port->irqflags = 0;
+		port->uartclk  = old_serial_port[i].baud_base * 16;
+		port->flags    = old_serial_port[i].flags;
+		port->hub6     = 0;
+		port->membase  = old_serial_port[i].iomem_base;
+		port->iotype   = old_serial_port[i].io_type;
+		port->regshift = old_serial_port[i].iomem_reg_shift;
+
+		port->irqflags |= irqflag;
+		if (serial8250_isa_config != NULL)
+			serial8250_isa_config(i, &up->port, &up->capabilities);
+	}
+}
+
+static void __init
+serial8250_register_ports(struct uart_driver *drv, struct device *dev)
+{
+	int i;
+
+	for (i = 0; i < nr_uarts; i++) {
+		struct uart_8250_port *up = &serial8250_ports[i];
+
+		if (up->port.type == PORT_8250_CIR)
+			continue;
+
+		if (up->port.dev)
+			continue;
+
+		up->port.dev = dev;
+
+		if (uart_console_registered(&up->port))
+			pm_runtime_get_sync(up->port.dev);
+
+		serial8250_apply_quirks(up);
+		uart_add_one_port(drv, &up->port);
+	}
+}
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+static void univ8250_console_write(struct console *co, const char *s,
+				   unsigned int count)
+{
+	struct uart_8250_port *up = &serial8250_ports[co->index];
+
+	serial8250_console_write(up, s, count);
+}
+
+static int univ8250_console_setup(struct console *co, char *options)
+{
+	struct uart_8250_port *up;
+	struct uart_port *port;
+	int retval, i;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= UART_NR)
+		co->index = 0;
+
+	/*
+	 * If the console is past the initial isa ports, init more ports up to
+	 * co->index as needed and increment nr_uarts accordingly.
+	 */
+	for (i = nr_uarts; i <= co->index; i++) {
+		up = serial8250_setup_port(i);
+		if (!up)
+			return -ENODEV;
+		nr_uarts++;
+	}
+
+	port = &serial8250_ports[co->index].port;
+	/* link port to console */
+	port->cons = co;
+
+	retval = serial8250_console_setup(port, options, false);
+	if (retval != 0)
+		port->cons = NULL;
+	return retval;
+}
+
+static int univ8250_console_exit(struct console *co)
+{
+	struct uart_port *port;
+
+	port = &serial8250_ports[co->index].port;
+	return serial8250_console_exit(port);
+}
+
+/**
+ *	univ8250_console_match - non-standard console matching
+ *	@co:	  registering console
+ *	@name:	  name from console command line
+ *	@idx:	  index from console command line
+ *	@options: ptr to option string from console command line
+ *
+ *	Only attempts to match console command lines of the form:
+ *	    console=uart[8250],io|mmio|mmio16|mmio32,<addr>[,<options>]
+ *	    console=uart[8250],0x<addr>[,<options>]
+ *	This form is used to register an initial earlycon boot console and
+ *	replace it with the serial8250_console at 8250 driver init.
+ *
+ *	Performs console setup for a match (as required by interface)
+ *	If no <options> are specified, then assume the h/w is already setup.
+ *
+ *	Returns 0 if console matches; otherwise non-zero to use default matching
+ */
+static int univ8250_console_match(struct console *co, char *name, int idx,
+				  char *options)
+{
+	char match[] = "uart";	/* 8250-specific earlycon name */
+	unsigned char iotype;
+	resource_size_t addr;
+	int i;
+
+	if (strncmp(name, match, 4) != 0)
+		return -ENODEV;
+
+	if (uart_parse_earlycon(options, &iotype, &addr, &options))
+		return -ENODEV;
+
+	/* try to match the port specified on the command line */
+	for (i = 0; i < nr_uarts; i++) {
+		struct uart_port *port = &serial8250_ports[i].port;
+
+		if (port->iotype != iotype)
+			continue;
+		if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 ||
+		     iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE)
+		    && (port->mapbase != addr))
+			continue;
+		if (iotype == UPIO_PORT && port->iobase != addr)
+			continue;
+
+		co->index = i;
+		port->cons = co;
+		return serial8250_console_setup(port, options, true);
+	}
+
+	return -ENODEV;
+}
+
+static struct console univ8250_console = {
+	.name		= "ttyS",
+	.write		= univ8250_console_write,
+	.device		= uart_console_device,
+	.setup		= univ8250_console_setup,
+	.exit		= univ8250_console_exit,
+	.match		= univ8250_console_match,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+	.index		= -1,
+	.data		= &serial8250_reg,
+};
+
+static int __init univ8250_console_init(void)
+{
+	if (nr_uarts == 0)
+		return -ENODEV;
+
+	serial8250_isa_init_ports();
+	register_console(&univ8250_console);
+	return 0;
+}
+console_initcall(univ8250_console_init);
+
+#define SERIAL8250_CONSOLE	(&univ8250_console)
+#else
+#define SERIAL8250_CONSOLE	NULL
+#endif
+
+static struct uart_driver serial8250_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "serial",
+	.dev_name		= "ttyS",
+	.major			= TTY_MAJOR,
+	.minor			= 64,
+	.cons			= SERIAL8250_CONSOLE,
+};
+
+/*
+ * early_serial_setup - early registration for 8250 ports
+ *
+ * Setup an 8250 port structure prior to console initialisation.  Use
+ * after console initialisation will cause undefined behaviour.
+ */
+int __init early_serial_setup(struct uart_port *port)
+{
+	struct uart_port *p;
+
+	if (port->line >= ARRAY_SIZE(serial8250_ports) || nr_uarts == 0)
+		return -ENODEV;
+
+	serial8250_isa_init_ports();
+	p = &serial8250_ports[port->line].port;
+	p->iobase       = port->iobase;
+	p->membase      = port->membase;
+	p->irq          = port->irq;
+	p->irqflags     = port->irqflags;
+	p->uartclk      = port->uartclk;
+	p->fifosize     = port->fifosize;
+	p->regshift     = port->regshift;
+	p->iotype       = port->iotype;
+	p->flags        = port->flags;
+	p->mapbase      = port->mapbase;
+	p->mapsize      = port->mapsize;
+	p->private_data = port->private_data;
+	p->type		= port->type;
+	p->line		= port->line;
+
+	serial8250_set_defaults(up_to_u8250p(p));
+
+	if (port->serial_in)
+		p->serial_in = port->serial_in;
+	if (port->serial_out)
+		p->serial_out = port->serial_out;
+	if (port->handle_irq)
+		p->handle_irq = port->handle_irq;
+
+	return 0;
+}
+
+/**
+ *	serial8250_suspend_port - suspend one serial port
+ *	@line:  serial line number
+ *
+ *	Suspend one serial port.
+ */
+void serial8250_suspend_port(int line)
+{
+	struct uart_8250_port *up = &serial8250_ports[line];
+	struct uart_port *port = &up->port;
+
+	if (!console_suspend_enabled && uart_console(port) &&
+	    port->type != PORT_8250) {
+		unsigned char canary = 0xa5;
+
+		serial_out(up, UART_SCR, canary);
+		if (serial_in(up, UART_SCR) == canary)
+			up->canary = canary;
+	}
+
+	uart_suspend_port(&serial8250_reg, port);
+}
+EXPORT_SYMBOL(serial8250_suspend_port);
+
+/**
+ *	serial8250_resume_port - resume one serial port
+ *	@line:  serial line number
+ *
+ *	Resume one serial port.
+ */
+void serial8250_resume_port(int line)
+{
+	struct uart_8250_port *up = &serial8250_ports[line];
+	struct uart_port *port = &up->port;
+
+	up->canary = 0;
+
+	if (up->capabilities & UART_NATSEMI) {
+		/* Ensure it's still in high speed mode */
+		serial_port_out(port, UART_LCR, 0xE0);
+
+		ns16550a_goto_highspeed(up);
+
+		serial_port_out(port, UART_LCR, 0);
+		port->uartclk = 921600*16;
+	}
+	uart_resume_port(&serial8250_reg, port);
+}
+EXPORT_SYMBOL(serial8250_resume_port);
+
+/*
+ * Register a set of serial devices attached to a platform device.  The
+ * list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set.
+ */
+static int serial8250_probe(struct platform_device *dev)
+{
+	struct plat_serial8250_port *p = dev_get_platdata(&dev->dev);
+	struct uart_8250_port uart;
+	int ret, i, irqflag = 0;
+
+	memset(&uart, 0, sizeof(uart));
+
+	if (share_irqs)
+		irqflag = IRQF_SHARED;
+
+	for (i = 0; p && p->flags != 0; p++, i++) {
+		uart.port.iobase	= p->iobase;
+		uart.port.membase	= p->membase;
+		uart.port.irq		= p->irq;
+		uart.port.irqflags	= p->irqflags;
+		uart.port.uartclk	= p->uartclk;
+		uart.port.regshift	= p->regshift;
+		uart.port.iotype	= p->iotype;
+		uart.port.flags		= p->flags;
+		uart.port.mapbase	= p->mapbase;
+		uart.port.mapsize	= p->mapsize;
+		uart.port.hub6		= p->hub6;
+		uart.port.has_sysrq	= p->has_sysrq;
+		uart.port.private_data	= p->private_data;
+		uart.port.type		= p->type;
+		uart.bugs		= p->bugs;
+		uart.port.serial_in	= p->serial_in;
+		uart.port.serial_out	= p->serial_out;
+		uart.dl_read		= p->dl_read;
+		uart.dl_write		= p->dl_write;
+		uart.port.handle_irq	= p->handle_irq;
+		uart.port.handle_break	= p->handle_break;
+		uart.port.set_termios	= p->set_termios;
+		uart.port.set_ldisc	= p->set_ldisc;
+		uart.port.get_mctrl	= p->get_mctrl;
+		uart.port.pm		= p->pm;
+		uart.port.dev		= &dev->dev;
+		uart.port.irqflags	|= irqflag;
+		ret = serial8250_register_8250_port(&uart);
+		if (ret < 0) {
+			dev_err(&dev->dev, "unable to register port at index %d "
+				"(IO%lx MEM%llx IRQ%d): %d\n", i,
+				p->iobase, (unsigned long long)p->mapbase,
+				p->irq, ret);
+		}
+	}
+	return 0;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int serial8250_remove(struct platform_device *dev)
+{
+	int i;
+
+	for (i = 0; i < nr_uarts; i++) {
+		struct uart_8250_port *up = &serial8250_ports[i];
+
+		if (up->port.dev == &dev->dev)
+			serial8250_unregister_port(i);
+	}
+	return 0;
+}
+
+static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
+{
+	int i;
+
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_8250_port *up = &serial8250_ports[i];
+
+		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
+			uart_suspend_port(&serial8250_reg, &up->port);
+	}
+
+	return 0;
+}
+
+static int serial8250_resume(struct platform_device *dev)
+{
+	int i;
+
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_8250_port *up = &serial8250_ports[i];
+
+		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
+			serial8250_resume_port(i);
+	}
+
+	return 0;
+}
+
+static struct platform_driver serial8250_isa_driver = {
+	.probe		= serial8250_probe,
+	.remove		= serial8250_remove,
+	.suspend	= serial8250_suspend,
+	.resume		= serial8250_resume,
+	.driver		= {
+		.name	= "serial8250",
+	},
+};
+
+/*
+ * This "device" covers _all_ ISA 8250-compatible serial devices listed
+ * in the table in include/asm/serial.h
+ */
+static struct platform_device *serial8250_isa_devs;
+
+/*
+ * serial8250_register_8250_port and serial8250_unregister_port allows for
+ * 16x50 serial ports to be configured at run-time, to support PCMCIA
+ * modems and PCI multiport cards.
+ */
+static DEFINE_MUTEX(serial_mutex);
+
+static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_port *port)
+{
+	int i;
+
+	/*
+	 * First, find a port entry which matches.
+	 */
+	for (i = 0; i < nr_uarts; i++)
+		if (uart_match_port(&serial8250_ports[i].port, port))
+			return &serial8250_ports[i];
+
+	/* try line number first if still available */
+	i = port->line;
+	if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN &&
+			serial8250_ports[i].port.iobase == 0)
+		return &serial8250_ports[i];
+	/*
+	 * We didn't find a matching entry, so look for the first
+	 * free entry.  We look for one which hasn't been previously
+	 * used (indicated by zero iobase).
+	 */
+	for (i = 0; i < nr_uarts; i++)
+		if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
+		    serial8250_ports[i].port.iobase == 0)
+			return &serial8250_ports[i];
+
+	/*
+	 * That also failed.  Last resort is to find any entry which
+	 * doesn't have a real port associated with it.
+	 */
+	for (i = 0; i < nr_uarts; i++)
+		if (serial8250_ports[i].port.type == PORT_UNKNOWN)
+			return &serial8250_ports[i];
+
+	return NULL;
+}
+
+static void serial_8250_overrun_backoff_work(struct work_struct *work)
+{
+	struct uart_8250_port *up =
+	    container_of(to_delayed_work(work), struct uart_8250_port,
+			 overrun_backoff);
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	up->ier |= UART_IER_RLSI | UART_IER_RDI;
+	up->port.read_status_mask |= UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/**
+ *	serial8250_register_8250_port - register a serial port
+ *	@up: serial port template
+ *
+ *	Configure the serial port specified by the request. If the
+ *	port exists and is in use, it is hung up and unregistered
+ *	first.
+ *
+ *	The port is then probed and if necessary the IRQ is autodetected
+ *	If this fails an error is returned.
+ *
+ *	On success the port is ready to use and the line number is returned.
+ */
+int serial8250_register_8250_port(const struct uart_8250_port *up)
+{
+	struct uart_8250_port *uart;
+	int ret = -ENOSPC;
+
+	if (up->port.uartclk == 0)
+		return -EINVAL;
+
+	mutex_lock(&serial_mutex);
+
+	uart = serial8250_find_match_or_unused(&up->port);
+	if (!uart) {
+		/*
+		 * If the port is past the initial isa ports, initialize a new
+		 * port and increment nr_uarts accordingly.
+		 */
+		uart = serial8250_setup_port(nr_uarts);
+		if (!uart)
+			goto unlock;
+		nr_uarts++;
+	}
+
+	if (uart->port.type != PORT_8250_CIR) {
+		struct mctrl_gpios *gpios;
+
+		if (uart->port.dev)
+			uart_remove_one_port(&serial8250_reg, &uart->port);
+
+		uart->port.ctrl_id	= up->port.ctrl_id;
+		uart->port.port_id	= up->port.port_id;
+		uart->port.iobase       = up->port.iobase;
+		uart->port.membase      = up->port.membase;
+		uart->port.irq          = up->port.irq;
+		uart->port.irqflags     = up->port.irqflags;
+		uart->port.uartclk      = up->port.uartclk;
+		uart->port.fifosize     = up->port.fifosize;
+		uart->port.regshift     = up->port.regshift;
+		uart->port.iotype       = up->port.iotype;
+		uart->port.flags        = up->port.flags | UPF_BOOT_AUTOCONF;
+		uart->bugs		= up->bugs;
+		uart->port.mapbase      = up->port.mapbase;
+		uart->port.mapsize      = up->port.mapsize;
+		uart->port.private_data = up->port.private_data;
+		uart->tx_loadsz		= up->tx_loadsz;
+		uart->capabilities	= up->capabilities;
+		uart->port.throttle	= up->port.throttle;
+		uart->port.unthrottle	= up->port.unthrottle;
+		uart->port.rs485_config	= up->port.rs485_config;
+		uart->port.rs485_supported = up->port.rs485_supported;
+		uart->port.rs485	= up->port.rs485;
+		uart->rs485_start_tx	= up->rs485_start_tx;
+		uart->rs485_stop_tx	= up->rs485_stop_tx;
+		uart->lsr_save_mask	= up->lsr_save_mask;
+		uart->dma		= up->dma;
+
+		/* Take tx_loadsz from fifosize if it wasn't set separately */
+		if (uart->port.fifosize && !uart->tx_loadsz)
+			uart->tx_loadsz = uart->port.fifosize;
+
+		if (up->port.dev) {
+			uart->port.dev = up->port.dev;
+			ret = uart_get_rs485_mode(&uart->port);
+			if (ret)
+				goto err;
+		}
+
+		if (up->port.flags & UPF_FIXED_TYPE)
+			uart->port.type = up->port.type;
+
+		/*
+		 * Only call mctrl_gpio_init(), if the device has no ACPI
+		 * companion device
+		 */
+		if (!has_acpi_companion(uart->port.dev)) {
+			gpios = mctrl_gpio_init(&uart->port, 0);
+			if (IS_ERR(gpios)) {
+				ret = PTR_ERR(gpios);
+				goto err;
+			} else {
+				uart->gpios = gpios;
+			}
+		}
+
+		serial8250_set_defaults(uart);
+
+		/* Possibly override default I/O functions.  */
+		if (up->port.serial_in)
+			uart->port.serial_in = up->port.serial_in;
+		if (up->port.serial_out)
+			uart->port.serial_out = up->port.serial_out;
+		if (up->port.handle_irq)
+			uart->port.handle_irq = up->port.handle_irq;
+		/*  Possibly override set_termios call */
+		if (up->port.set_termios)
+			uart->port.set_termios = up->port.set_termios;
+		if (up->port.set_ldisc)
+			uart->port.set_ldisc = up->port.set_ldisc;
+		if (up->port.get_mctrl)
+			uart->port.get_mctrl = up->port.get_mctrl;
+		if (up->port.set_mctrl)
+			uart->port.set_mctrl = up->port.set_mctrl;
+		if (up->port.get_divisor)
+			uart->port.get_divisor = up->port.get_divisor;
+		if (up->port.set_divisor)
+			uart->port.set_divisor = up->port.set_divisor;
+		if (up->port.startup)
+			uart->port.startup = up->port.startup;
+		if (up->port.shutdown)
+			uart->port.shutdown = up->port.shutdown;
+		if (up->port.pm)
+			uart->port.pm = up->port.pm;
+		if (up->port.handle_break)
+			uart->port.handle_break = up->port.handle_break;
+		if (up->dl_read)
+			uart->dl_read = up->dl_read;
+		if (up->dl_write)
+			uart->dl_write = up->dl_write;
+
+		if (uart->port.type != PORT_8250_CIR) {
+			if (serial8250_isa_config != NULL)
+				serial8250_isa_config(0, &uart->port,
+						&uart->capabilities);
+
+			serial8250_apply_quirks(uart);
+			ret = uart_add_one_port(&serial8250_reg,
+						&uart->port);
+			if (ret)
+				goto err;
+
+			ret = uart->port.line;
+		} else {
+			dev_info(uart->port.dev,
+				"skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
+				uart->port.iobase,
+				(unsigned long long)uart->port.mapbase,
+				uart->port.irq);
+
+			ret = 0;
+		}
+
+		if (!uart->lsr_save_mask)
+			uart->lsr_save_mask = LSR_SAVE_FLAGS;	/* Use default LSR mask */
+
+		/* Initialise interrupt backoff work if required */
+		if (up->overrun_backoff_time_ms > 0) {
+			uart->overrun_backoff_time_ms =
+				up->overrun_backoff_time_ms;
+			INIT_DELAYED_WORK(&uart->overrun_backoff,
+					serial_8250_overrun_backoff_work);
+		} else {
+			uart->overrun_backoff_time_ms = 0;
+		}
+	}
+
+unlock:
+	mutex_unlock(&serial_mutex);
+
+	return ret;
+
+err:
+	uart->port.dev = NULL;
+	mutex_unlock(&serial_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(serial8250_register_8250_port);
+
+/**
+ *	serial8250_unregister_port - remove a 16x50 serial port at runtime
+ *	@line: serial line number
+ *
+ *	Remove one serial port.  This may not be called from interrupt
+ *	context.  We hand the port back to the our control.
+ */
+void serial8250_unregister_port(int line)
+{
+	struct uart_8250_port *uart = &serial8250_ports[line];
+
+	mutex_lock(&serial_mutex);
+
+	if (uart->em485) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&uart->port.lock, flags);
+		serial8250_em485_destroy(uart);
+		spin_unlock_irqrestore(&uart->port.lock, flags);
+	}
+
+	uart_remove_one_port(&serial8250_reg, &uart->port);
+	if (serial8250_isa_devs) {
+		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
+		uart->port.type = PORT_UNKNOWN;
+		uart->port.dev = &serial8250_isa_devs->dev;
+		uart->port.port_id = line;
+		uart->capabilities = 0;
+		serial8250_init_port(uart);
+		serial8250_apply_quirks(uart);
+		uart_add_one_port(&serial8250_reg, &uart->port);
+	} else {
+		uart->port.dev = NULL;
+	}
+	mutex_unlock(&serial_mutex);
+}
+EXPORT_SYMBOL(serial8250_unregister_port);
+
+static int __init serial8250_init(void)
+{
+	int ret;
+
+	if (nr_uarts == 0)
+		return -ENODEV;
+
+	serial8250_isa_init_ports();
+
+	pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n",
+		nr_uarts, str_enabled_disabled(share_irqs));
+
+#ifdef CONFIG_SPARC
+	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
+#else
+	serial8250_reg.nr = UART_NR;
+	ret = uart_register_driver(&serial8250_reg);
+#endif
+	if (ret)
+		goto out;
+
+	ret = serial8250_pnp_init();
+	if (ret)
+		goto unreg_uart_drv;
+
+	serial8250_isa_devs = platform_device_alloc("serial8250",
+						    PLAT8250_DEV_LEGACY);
+	if (!serial8250_isa_devs) {
+		ret = -ENOMEM;
+		goto unreg_pnp;
+	}
+
+	ret = platform_device_add(serial8250_isa_devs);
+	if (ret)
+		goto put_dev;
+
+	serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
+
+	ret = platform_driver_register(&serial8250_isa_driver);
+	if (ret == 0)
+		goto out;
+
+	platform_device_del(serial8250_isa_devs);
+put_dev:
+	platform_device_put(serial8250_isa_devs);
+unreg_pnp:
+	serial8250_pnp_exit();
+unreg_uart_drv:
+#ifdef CONFIG_SPARC
+	sunserial_unregister_minors(&serial8250_reg, UART_NR);
+#else
+	uart_unregister_driver(&serial8250_reg);
+#endif
+out:
+	return ret;
+}
+
+static void __exit serial8250_exit(void)
+{
+	struct platform_device *isa_dev = serial8250_isa_devs;
+
+	/*
+	 * This tells serial8250_unregister_port() not to re-register
+	 * the ports (thereby making serial8250_isa_driver permanently
+	 * in use.)
+	 */
+	serial8250_isa_devs = NULL;
+
+	platform_driver_unregister(&serial8250_isa_driver);
+	platform_device_unregister(isa_dev);
+
+	serial8250_pnp_exit();
+
+#ifdef CONFIG_SPARC
+	sunserial_unregister_minors(&serial8250_reg, UART_NR);
+#else
+	uart_unregister_driver(&serial8250_reg);
+#endif
+}
+
+module_init(serial8250_init);
+module_exit(serial8250_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
+
+module_param_hw(share_irqs, uint, other, 0644);
+MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)");
+
+module_param(nr_uarts, uint, 0644);
+MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
+
+module_param(skip_txen_test, uint, 0644);
+MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
+
+#ifdef CONFIG_SERIAL_8250_RSA
+module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444);
+MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
+#endif
+MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);
+
+#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS
+#ifndef MODULE
+/* This module was renamed to 8250_core in 3.7.  Keep the old "8250" name
+ * working as well for the module options so we don't break people.  We
+ * need to keep the names identical and the convenient macros will happily
+ * refuse to let us do that by failing the build with redefinition errors
+ * of global variables.  So we stick them inside a dummy function to avoid
+ * those conflicts.  The options still get parsed, and the redefined
+ * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive.
+ *
+ * This is hacky.  I'm sorry.
+ */
+static void __used s8250_options(void)
+{
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "8250_core."
+
+	module_param_cb(share_irqs, &param_ops_uint, &share_irqs, 0644);
+	module_param_cb(nr_uarts, &param_ops_uint, &nr_uarts, 0644);
+	module_param_cb(skip_txen_test, &param_ops_uint, &skip_txen_test, 0644);
+#ifdef CONFIG_SERIAL_8250_RSA
+	__module_param_call(MODULE_PARAM_PREFIX, probe_rsa,
+		&param_array_ops, .arr = &__param_arr_probe_rsa,
+		0444, -1, 0);
+#endif
+}
+#else
+MODULE_ALIAS("8250_core");
+#endif
+#endif
diff --git a/drivers/tty/serial/8250/8250_dfl.c b/drivers/tty/serial/8250/8250_dfl.c
new file mode 100644
index 000000000..6c5ff019d
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dfl.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for FPGA UART
+ *
+ * Copyright (C) 2022 Intel Corporation.
+ *
+ * Authors:
+ *   Ananda Ravuri <ananda.ravuri@intel.com>
+ *   Matthew Gerlach <matthew.gerlach@linux.intel.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/dfl.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/types.h>
+
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+
+#define DFHv1_PARAM_ID_CLK_FRQ    0x2
+#define DFHv1_PARAM_ID_FIFO_LEN   0x3
+
+#define DFHv1_PARAM_ID_REG_LAYOUT	0x4
+#define DFHv1_PARAM_REG_LAYOUT_WIDTH	GENMASK_ULL(63, 32)
+#define DFHv1_PARAM_REG_LAYOUT_SHIFT	GENMASK_ULL(31, 0)
+
+struct dfl_uart {
+	int line;
+};
+
+static int dfh_get_u64_param_val(struct dfl_device *dfl_dev, int param_id, u64 *pval)
+{
+	size_t psize;
+	u64 *p;
+
+	p = dfh_find_param(dfl_dev, param_id, &psize);
+	if (IS_ERR(p))
+		return PTR_ERR(p);
+
+	if (psize != sizeof(*pval))
+		return -EINVAL;
+
+	*pval = *p;
+
+	return 0;
+}
+
+static int dfl_uart_get_params(struct dfl_device *dfl_dev, struct uart_8250_port *uart)
+{
+	struct device *dev = &dfl_dev->dev;
+	u64 fifo_len, clk_freq, reg_layout;
+	u32 reg_width;
+	int ret;
+
+	ret = dfh_get_u64_param_val(dfl_dev, DFHv1_PARAM_ID_CLK_FRQ, &clk_freq);
+	if (ret)
+		return dev_err_probe(dev, ret, "missing CLK_FRQ param\n");
+
+	uart->port.uartclk = clk_freq;
+
+	ret = dfh_get_u64_param_val(dfl_dev, DFHv1_PARAM_ID_FIFO_LEN, &fifo_len);
+	if (ret)
+		return dev_err_probe(dev, ret, "missing FIFO_LEN param\n");
+
+	switch (fifo_len) {
+	case 32:
+		uart->port.type = PORT_ALTR_16550_F32;
+		break;
+
+	case 64:
+		uart->port.type = PORT_ALTR_16550_F64;
+		break;
+
+	case 128:
+		uart->port.type = PORT_ALTR_16550_F128;
+		break;
+
+	default:
+		return dev_err_probe(dev, -EINVAL, "unsupported FIFO_LEN %llu\n", fifo_len);
+	}
+
+	ret = dfh_get_u64_param_val(dfl_dev, DFHv1_PARAM_ID_REG_LAYOUT, &reg_layout);
+	if (ret)
+		return dev_err_probe(dev, ret, "missing REG_LAYOUT param\n");
+
+	uart->port.regshift = FIELD_GET(DFHv1_PARAM_REG_LAYOUT_SHIFT, reg_layout);
+	reg_width = FIELD_GET(DFHv1_PARAM_REG_LAYOUT_WIDTH, reg_layout);
+	switch (reg_width) {
+	case 4:
+		uart->port.iotype = UPIO_MEM32;
+		break;
+
+	case 2:
+		uart->port.iotype = UPIO_MEM16;
+		break;
+
+	default:
+		return dev_err_probe(dev, -EINVAL, "unsupported reg-width %u\n", reg_width);
+
+	}
+
+	return 0;
+}
+
+static int dfl_uart_probe(struct dfl_device *dfl_dev)
+{
+	struct device *dev = &dfl_dev->dev;
+	struct uart_8250_port uart = { };
+	struct dfl_uart *dfluart;
+	int ret;
+
+	uart.port.flags = UPF_IOREMAP;
+	uart.port.mapbase = dfl_dev->mmio_res.start;
+	uart.port.mapsize = resource_size(&dfl_dev->mmio_res);
+
+	ret = dfl_uart_get_params(dfl_dev, &uart);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed uart feature walk\n");
+
+	if (dfl_dev->num_irqs == 1)
+		uart.port.irq = dfl_dev->irqs[0];
+
+	dfluart = devm_kzalloc(dev, sizeof(*dfluart), GFP_KERNEL);
+	if (!dfluart)
+		return -ENOMEM;
+
+	dfluart->line = serial8250_register_8250_port(&uart);
+	if (dfluart->line < 0)
+		return dev_err_probe(dev, dfluart->line, "unable to register 8250 port.\n");
+
+	dev_set_drvdata(dev, dfluart);
+
+	return 0;
+}
+
+static void dfl_uart_remove(struct dfl_device *dfl_dev)
+{
+	struct dfl_uart *dfluart = dev_get_drvdata(&dfl_dev->dev);
+
+	serial8250_unregister_port(dfluart->line);
+}
+
+#define FME_FEATURE_ID_UART 0x24
+
+static const struct dfl_device_id dfl_uart_ids[] = {
+	{ FME_ID, FME_FEATURE_ID_UART },
+	{ }
+};
+MODULE_DEVICE_TABLE(dfl, dfl_uart_ids);
+
+static struct dfl_driver dfl_uart_driver = {
+	.drv = {
+		.name = "dfl-uart",
+	},
+	.id_table = dfl_uart_ids,
+	.probe = dfl_uart_probe,
+	.remove = dfl_uart_remove,
+};
+module_dfl_driver(dfl_uart_driver);
+
+MODULE_DESCRIPTION("DFL Intel UART driver");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
new file mode 100644
index 000000000..7fa665017
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * 8250_dma.c - DMA Engine API support for 8250.c
+ *
+ * Copyright (C) 2013 Intel Corporation
+ */
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_reg.h>
+#include <linux/dma-mapping.h>
+
+#include "8250.h"
+
+static void __dma_tx_complete(void *param)
+{
+	struct uart_8250_port	*p = param;
+	struct uart_8250_dma	*dma = p->dma;
+	struct circ_buf		*xmit = &p->port.state->xmit;
+	unsigned long	flags;
+	int		ret;
+
+	dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
+				UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+	spin_lock_irqsave(&p->port.lock, flags);
+
+	dma->tx_running = 0;
+
+	uart_xmit_advance(&p->port, dma->tx_size);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&p->port);
+
+	ret = serial8250_tx_dma(p);
+	if (ret || !dma->tx_running)
+		serial8250_set_THRI(p);
+
+	spin_unlock_irqrestore(&p->port.lock, flags);
+}
+
+static void __dma_rx_complete(struct uart_8250_port *p)
+{
+	struct uart_8250_dma	*dma = p->dma;
+	struct tty_port		*tty_port = &p->port.state->port;
+	struct dma_tx_state	state;
+	enum dma_status		dma_status;
+	int			count;
+
+	/*
+	 * New DMA Rx can be started during the completion handler before it
+	 * could acquire port's lock and it might still be ongoing. Don't to
+	 * anything in such case.
+	 */
+	dma_status = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+	if (dma_status == DMA_IN_PROGRESS)
+		return;
+
+	count = dma->rx_size - state.residue;
+
+	tty_insert_flip_string(tty_port, dma->rx_buf, count);
+	p->port.icount.rx += count;
+	dma->rx_running = 0;
+
+	tty_flip_buffer_push(tty_port);
+}
+
+static void dma_rx_complete(void *param)
+{
+	struct uart_8250_port *p = param;
+	struct uart_8250_dma *dma = p->dma;
+	unsigned long flags;
+
+	spin_lock_irqsave(&p->port.lock, flags);
+	if (dma->rx_running)
+		__dma_rx_complete(p);
+
+	/*
+	 * Cannot be combined with the previous check because __dma_rx_complete()
+	 * changes dma->rx_running.
+	 */
+	if (!dma->rx_running && (serial_lsr_in(p) & UART_LSR_DR))
+		p->dma->rx_dma(p);
+	spin_unlock_irqrestore(&p->port.lock, flags);
+}
+
+int serial8250_tx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma		*dma = p->dma;
+	struct circ_buf			*xmit = &p->port.state->xmit;
+	struct dma_async_tx_descriptor	*desc;
+	struct uart_port		*up = &p->port;
+	int ret;
+
+	if (dma->tx_running) {
+		if (up->x_char) {
+			dmaengine_pause(dma->txchan);
+			uart_xchar_out(up, UART_TX);
+			dmaengine_resume(dma->txchan);
+		}
+		return 0;
+	} else if (up->x_char) {
+		uart_xchar_out(up, UART_TX);
+	}
+
+	if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) {
+		/* We have been called from __dma_tx_complete() */
+		return 0;
+	}
+
+	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	serial8250_do_prepare_tx_dma(p);
+
+	desc = dmaengine_prep_slave_single(dma->txchan,
+					   dma->tx_addr + xmit->tail,
+					   dma->tx_size, DMA_MEM_TO_DEV,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dma->tx_running = 1;
+	desc->callback = __dma_tx_complete;
+	desc->callback_param = p;
+
+	dma->tx_cookie = dmaengine_submit(desc);
+
+	dma_sync_single_for_device(dma->txchan->device->dev, dma->tx_addr,
+				   UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+	dma_async_issue_pending(dma->txchan);
+	serial8250_clear_THRI(p);
+	dma->tx_err = 0;
+
+	return 0;
+err:
+	dma->tx_err = 1;
+	return ret;
+}
+
+int serial8250_rx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma		*dma = p->dma;
+	struct dma_async_tx_descriptor	*desc;
+
+	if (dma->rx_running)
+		return 0;
+
+	serial8250_do_prepare_rx_dma(p);
+
+	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
+					   dma->rx_size, DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EBUSY;
+
+	dma->rx_running = 1;
+	desc->callback = dma_rx_complete;
+	desc->callback_param = p;
+
+	dma->rx_cookie = dmaengine_submit(desc);
+
+	dma_async_issue_pending(dma->rxchan);
+
+	return 0;
+}
+
+void serial8250_rx_dma_flush(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	if (dma->rx_running) {
+		dmaengine_pause(dma->rxchan);
+		__dma_rx_complete(p);
+		dmaengine_terminate_async(dma->rxchan);
+	}
+}
+EXPORT_SYMBOL_GPL(serial8250_rx_dma_flush);
+
+int serial8250_request_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma	*dma = p->dma;
+	phys_addr_t rx_dma_addr = dma->rx_dma_addr ?
+				  dma->rx_dma_addr : p->port.mapbase;
+	phys_addr_t tx_dma_addr = dma->tx_dma_addr ?
+				  dma->tx_dma_addr : p->port.mapbase;
+	dma_cap_mask_t		mask;
+	struct dma_slave_caps	caps;
+	int			ret;
+
+	/* Default slave configuration parameters */
+	dma->rxconf.direction		= DMA_DEV_TO_MEM;
+	dma->rxconf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma->rxconf.src_addr		= rx_dma_addr + UART_RX;
+
+	dma->txconf.direction		= DMA_MEM_TO_DEV;
+	dma->txconf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma->txconf.dst_addr		= tx_dma_addr + UART_TX;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	/* Get a channel for RX */
+	dma->rxchan = dma_request_slave_channel_compat(mask,
+						       dma->fn, dma->rx_param,
+						       p->port.dev, "rx");
+	if (!dma->rxchan)
+		return -ENODEV;
+
+	/* 8250 rx dma requires dmaengine driver to support pause/terminate */
+	ret = dma_get_slave_caps(dma->rxchan, &caps);
+	if (ret)
+		goto release_rx;
+	if (!caps.cmd_pause || !caps.cmd_terminate ||
+	    caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) {
+		ret = -EINVAL;
+		goto release_rx;
+	}
+
+	dmaengine_slave_config(dma->rxchan, &dma->rxconf);
+
+	/* Get a channel for TX */
+	dma->txchan = dma_request_slave_channel_compat(mask,
+						       dma->fn, dma->tx_param,
+						       p->port.dev, "tx");
+	if (!dma->txchan) {
+		ret = -ENODEV;
+		goto release_rx;
+	}
+
+	/* 8250 tx dma requires dmaengine driver to support terminate */
+	ret = dma_get_slave_caps(dma->txchan, &caps);
+	if (ret)
+		goto err;
+	if (!caps.cmd_terminate) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	dmaengine_slave_config(dma->txchan, &dma->txconf);
+
+	/* RX buffer */
+	if (!dma->rx_size)
+		dma->rx_size = PAGE_SIZE;
+
+	dma->rx_buf = dma_alloc_coherent(dma->rxchan->device->dev, dma->rx_size,
+					&dma->rx_addr, GFP_KERNEL);
+	if (!dma->rx_buf) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* TX buffer */
+	dma->tx_addr = dma_map_single(dma->txchan->device->dev,
+					p->port.state->xmit.buf,
+					UART_XMIT_SIZE,
+					DMA_TO_DEVICE);
+	if (dma_mapping_error(dma->txchan->device->dev, dma->tx_addr)) {
+		dma_free_coherent(dma->rxchan->device->dev, dma->rx_size,
+				  dma->rx_buf, dma->rx_addr);
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dev_dbg_ratelimited(p->port.dev, "got both dma channels\n");
+
+	return 0;
+err:
+	dma_release_channel(dma->txchan);
+release_rx:
+	dma_release_channel(dma->rxchan);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(serial8250_request_dma);
+
+void serial8250_release_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma *dma = p->dma;
+
+	if (!dma)
+		return;
+
+	/* Release RX resources */
+	dmaengine_terminate_sync(dma->rxchan);
+	dma_free_coherent(dma->rxchan->device->dev, dma->rx_size, dma->rx_buf,
+			  dma->rx_addr);
+	dma_release_channel(dma->rxchan);
+	dma->rxchan = NULL;
+
+	/* Release TX resources */
+	dmaengine_terminate_sync(dma->txchan);
+	dma_unmap_single(dma->txchan->device->dev, dma->tx_addr,
+			 UART_XMIT_SIZE, DMA_TO_DEVICE);
+	dma_release_channel(dma->txchan);
+	dma->txchan = NULL;
+	dma->tx_running = 0;
+
+	dev_dbg_ratelimited(p->port.dev, "dma channels released\n");
+}
+EXPORT_SYMBOL_GPL(serial8250_release_dma);
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
new file mode 100644
index 000000000..a1f2259cc
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -0,0 +1,822 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Synopsys DesignWare 8250 driver.
+ *
+ * Copyright 2011 Picochip, Jamie Iles.
+ * Copyright 2013 Intel Corporation
+ *
+ * The Synopsys DesignWare 8250 has an extra feature whereby it detects if the
+ * LCR is written whilst busy.  If it is, then a busy detect interrupt is
+ * raised, the LCR needs to be rewritten and the uart status register read.
+ */
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#include <asm/byteorder.h>
+
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+
+#include "8250_dwlib.h"
+
+/* Offsets for the DesignWare specific registers */
+#define DW_UART_USR	0x1f /* UART Status Register */
+#define DW_UART_DMASA	0xa8 /* DMA Software Ack */
+
+#define OCTEON_UART_USR	0x27 /* UART Status Register */
+
+#define RZN1_UART_TDMACR 0x10c /* DMA Control Register Transmit Mode */
+#define RZN1_UART_RDMACR 0x110 /* DMA Control Register Receive Mode */
+
+/* DesignWare specific register fields */
+#define DW_UART_MCR_SIRE		BIT(6)
+
+/* Renesas specific register fields */
+#define RZN1_UART_xDMACR_DMA_EN		BIT(0)
+#define RZN1_UART_xDMACR_1_WORD_BURST	(0 << 1)
+#define RZN1_UART_xDMACR_4_WORD_BURST	(1 << 1)
+#define RZN1_UART_xDMACR_8_WORD_BURST	(2 << 1)
+#define RZN1_UART_xDMACR_BLK_SZ(x)	((x) << 3)
+
+/* Quirks */
+#define DW_UART_QUIRK_OCTEON		BIT(0)
+#define DW_UART_QUIRK_ARMADA_38X	BIT(1)
+#define DW_UART_QUIRK_SKIP_SET_RATE	BIT(2)
+#define DW_UART_QUIRK_IS_DMA_FC		BIT(3)
+
+static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
+{
+	return container_of(nb, struct dw8250_data, clk_notifier);
+}
+
+static inline struct dw8250_data *work_to_dw8250_data(struct work_struct *work)
+{
+	return container_of(work, struct dw8250_data, clk_work);
+}
+
+static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+
+	/* Override any modem control signals if needed */
+	if (offset == UART_MSR) {
+		value |= d->msr_mask_on;
+		value &= ~d->msr_mask_off;
+	}
+
+	return value;
+}
+
+static void dw8250_force_idle(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int lsr;
+
+	serial8250_clear_and_reinit_fifos(up);
+
+	/*
+	 * With PSLVERR_RESP_EN parameter set to 1, the device generates an
+	 * error response when an attempt to read an empty RBR with FIFO
+	 * enabled.
+	 */
+	if (up->fcr & UART_FCR_ENABLE_FIFO) {
+		lsr = p->serial_in(p, UART_LSR);
+		if (!(lsr & UART_LSR_DR))
+			return;
+	}
+
+	(void)p->serial_in(p, UART_RX);
+}
+
+static void dw8250_check_lcr(struct uart_port *p, int value)
+{
+	void __iomem *offset = p->membase + (UART_LCR << p->regshift);
+	int tries = 1000;
+
+	/* Make sure LCR write wasn't ignored */
+	while (tries--) {
+		unsigned int lcr = p->serial_in(p, UART_LCR);
+
+		if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
+			return;
+
+		dw8250_force_idle(p);
+
+#ifdef CONFIG_64BIT
+		if (p->type == PORT_OCTEON)
+			__raw_writeq(value & 0xff, offset);
+		else
+#endif
+		if (p->iotype == UPIO_MEM32)
+			writel(value, offset);
+		else if (p->iotype == UPIO_MEM32BE)
+			iowrite32be(value, offset);
+		else
+			writeb(value, offset);
+	}
+	/*
+	 * FIXME: this deadlocks if port->lock is already held
+	 * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
+	 */
+}
+
+/* Returns once the transmitter is empty or we run out of retries */
+static void dw8250_tx_wait_empty(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int tries = 20000;
+	unsigned int delay_threshold = tries - 1000;
+	unsigned int lsr;
+
+	while (tries--) {
+		lsr = readb (p->membase + (UART_LSR << p->regshift));
+		up->lsr_saved_flags |= lsr & up->lsr_save_mask;
+
+		if (lsr & UART_LSR_TEMT)
+			break;
+
+		/* The device is first given a chance to empty without delay,
+		 * to avoid slowdowns at high bitrates. If after 1000 tries
+		 * the buffer has still not emptied, allow more time for low-
+		 * speed links. */
+		if (tries < delay_threshold)
+			udelay (1);
+	}
+}
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+
+	writeb(value, p->membase + (offset << p->regshift));
+
+	if (offset == UART_LCR && !d->uart_16550_compatible)
+		dw8250_check_lcr(p, value);
+}
+
+static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
+{
+	/* Allow the TX to drain before we reconfigure */
+	if (offset == UART_LCR)
+		dw8250_tx_wait_empty(p);
+
+	dw8250_serial_out(p, offset, value);
+}
+
+static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
+{
+	unsigned int value = readb(p->membase + (offset << p->regshift));
+
+	return dw8250_modify_msr(p, offset, value);
+}
+
+#ifdef CONFIG_64BIT
+static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)
+{
+	unsigned int value;
+
+	value = (u8)__raw_readq(p->membase + (offset << p->regshift));
+
+	return dw8250_modify_msr(p, offset, value);
+}
+
+static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+
+	value &= 0xff;
+	__raw_writeq(value, p->membase + (offset << p->regshift));
+	/* Read back to ensure register write ordering. */
+	__raw_readq(p->membase + (UART_LCR << p->regshift));
+
+	if (offset == UART_LCR && !d->uart_16550_compatible)
+		dw8250_check_lcr(p, value);
+}
+#endif /* CONFIG_64BIT */
+
+static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+
+	writel(value, p->membase + (offset << p->regshift));
+
+	if (offset == UART_LCR && !d->uart_16550_compatible)
+		dw8250_check_lcr(p, value);
+}
+
+static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
+{
+	unsigned int value = readl(p->membase + (offset << p->regshift));
+
+	return dw8250_modify_msr(p, offset, value);
+}
+
+static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+
+	iowrite32be(value, p->membase + (offset << p->regshift));
+
+	if (offset == UART_LCR && !d->uart_16550_compatible)
+		dw8250_check_lcr(p, value);
+}
+
+static unsigned int dw8250_serial_in32be(struct uart_port *p, int offset)
+{
+       unsigned int value = ioread32be(p->membase + (offset << p->regshift));
+
+       return dw8250_modify_msr(p, offset, value);
+}
+
+
+static int dw8250_handle_irq(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+	unsigned int iir = p->serial_in(p, UART_IIR);
+	bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT;
+	unsigned int quirks = d->pdata->quirks;
+	unsigned int status;
+	unsigned long flags;
+
+	/*
+	 * There are ways to get Designware-based UARTs into a state where
+	 * they are asserting UART_IIR_RX_TIMEOUT but there is no actual
+	 * data available.  If we see such a case then we'll do a bogus
+	 * read.  If we don't do this then the "RX TIMEOUT" interrupt will
+	 * fire forever.
+	 *
+	 * This problem has only been observed so far when not in DMA mode
+	 * so we limit the workaround only to non-DMA mode.
+	 */
+	if (!up->dma && rx_timeout) {
+		spin_lock_irqsave(&p->lock, flags);
+		status = serial_lsr_in(up);
+
+		if (!(status & (UART_LSR_DR | UART_LSR_BI)))
+			(void) p->serial_in(p, UART_RX);
+
+		spin_unlock_irqrestore(&p->lock, flags);
+	}
+
+	/* Manually stop the Rx DMA transfer when acting as flow controller */
+	if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
+		spin_lock_irqsave(&p->lock, flags);
+		status = serial_lsr_in(up);
+		spin_unlock_irqrestore(&p->lock, flags);
+
+		if (status & (UART_LSR_DR | UART_LSR_BI)) {
+			dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
+			dw8250_writel_ext(p, DW_UART_DMASA, 1);
+		}
+	}
+
+	if (serial8250_handle_irq(p, iir))
+		return 1;
+
+	if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
+		/* Clear the USR */
+		(void)p->serial_in(p, d->pdata->usr_reg);
+
+		return 1;
+	}
+
+	return 0;
+}
+
+static void dw8250_clk_work_cb(struct work_struct *work)
+{
+	struct dw8250_data *d = work_to_dw8250_data(work);
+	struct uart_8250_port *up;
+	unsigned long rate;
+
+	rate = clk_get_rate(d->clk);
+	if (rate <= 0)
+		return;
+
+	up = serial8250_get_port(d->data.line);
+
+	serial8250_update_uartclk(&up->port, rate);
+}
+
+static int dw8250_clk_notifier_cb(struct notifier_block *nb,
+				  unsigned long event, void *data)
+{
+	struct dw8250_data *d = clk_to_dw8250_data(nb);
+
+	/*
+	 * We have no choice but to defer the uartclk update due to two
+	 * deadlocks. First one is caused by a recursive mutex lock which
+	 * happens when clk_set_rate() is called from dw8250_set_termios().
+	 * Second deadlock is more tricky and is caused by an inverted order of
+	 * the clk and tty-port mutexes lock. It happens if clock rate change
+	 * is requested asynchronously while set_termios() is executed between
+	 * tty-port mutex lock and clk_set_rate() function invocation and
+	 * vise-versa. Anyway if we didn't have the reference clock alteration
+	 * in the dw8250_set_termios() method we wouldn't have needed this
+	 * deferred event handling complication.
+	 */
+	if (event == POST_RATE_CHANGE) {
+		queue_work(system_unbound_wq, &d->clk_work);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void
+dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
+{
+	if (!state)
+		pm_runtime_get_sync(port->dev);
+
+	serial8250_do_pm(port, state, old);
+
+	if (state)
+		pm_runtime_put_sync_suspend(port->dev);
+}
+
+static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
+			       const struct ktermios *old)
+{
+	unsigned long newrate = tty_termios_baud_rate(termios) * 16;
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+	long rate;
+	int ret;
+
+	clk_disable_unprepare(d->clk);
+	rate = clk_round_rate(d->clk, newrate);
+	if (rate > 0) {
+		/*
+		 * Note that any clock-notifer worker will block in
+		 * serial8250_update_uartclk() until we are done.
+		 */
+		ret = clk_set_rate(d->clk, newrate);
+		if (!ret)
+			p->uartclk = rate;
+	}
+	clk_prepare_enable(d->clk);
+
+	dw8250_do_set_termios(p, termios, old);
+}
+
+static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int mcr = p->serial_in(p, UART_MCR);
+
+	if (up->capabilities & UART_CAP_IRDA) {
+		if (termios->c_line == N_IRDA)
+			mcr |= DW_UART_MCR_SIRE;
+		else
+			mcr &= ~DW_UART_MCR_SIRE;
+
+		p->serial_out(p, UART_MCR, mcr);
+	}
+	serial8250_do_set_ldisc(p, termios);
+}
+
+/*
+ * dw8250_fallback_dma_filter will prevent the UART from getting just any free
+ * channel on platforms that have DMA engines, but don't have any channels
+ * assigned to the UART.
+ *
+ * REVISIT: This is a work around for limitation in the DMA Engine API. Once the
+ * core problem is fixed, this function is no longer needed.
+ */
+static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
+{
+	return false;
+}
+
+static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
+{
+	return param == chan->device->dev;
+}
+
+static u32 dw8250_rzn1_get_dmacr_burst(int max_burst)
+{
+	if (max_burst >= 8)
+		return RZN1_UART_xDMACR_8_WORD_BURST;
+	else if (max_burst >= 4)
+		return RZN1_UART_xDMACR_4_WORD_BURST;
+	else
+		return RZN1_UART_xDMACR_1_WORD_BURST;
+}
+
+static void dw8250_prepare_tx_dma(struct uart_8250_port *p)
+{
+	struct uart_port *up = &p->port;
+	struct uart_8250_dma *dma = p->dma;
+	u32 val;
+
+	dw8250_writel_ext(up, RZN1_UART_TDMACR, 0);
+	val = dw8250_rzn1_get_dmacr_burst(dma->txconf.dst_maxburst) |
+	      RZN1_UART_xDMACR_BLK_SZ(dma->tx_size) |
+	      RZN1_UART_xDMACR_DMA_EN;
+	dw8250_writel_ext(up, RZN1_UART_TDMACR, val);
+}
+
+static void dw8250_prepare_rx_dma(struct uart_8250_port *p)
+{
+	struct uart_port *up = &p->port;
+	struct uart_8250_dma *dma = p->dma;
+	u32 val;
+
+	dw8250_writel_ext(up, RZN1_UART_RDMACR, 0);
+	val = dw8250_rzn1_get_dmacr_burst(dma->rxconf.src_maxburst) |
+	      RZN1_UART_xDMACR_BLK_SZ(dma->rx_size) |
+	      RZN1_UART_xDMACR_DMA_EN;
+	dw8250_writel_ext(up, RZN1_UART_RDMACR, val);
+}
+
+static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
+{
+	struct device_node *np = p->dev->of_node;
+
+	if (np) {
+		unsigned int quirks = data->pdata->quirks;
+		int id;
+
+		/* get index of serial line, if found in DT aliases */
+		id = of_alias_get_id(np, "serial");
+		if (id >= 0)
+			p->line = id;
+#ifdef CONFIG_64BIT
+		if (quirks & DW_UART_QUIRK_OCTEON) {
+			p->serial_in = dw8250_serial_inq;
+			p->serial_out = dw8250_serial_outq;
+			p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
+			p->type = PORT_OCTEON;
+			data->skip_autocfg = true;
+		}
+#endif
+
+		if (of_device_is_big_endian(np)) {
+			p->iotype = UPIO_MEM32BE;
+			p->serial_in = dw8250_serial_in32be;
+			p->serial_out = dw8250_serial_out32be;
+		}
+
+		if (quirks & DW_UART_QUIRK_ARMADA_38X)
+			p->serial_out = dw8250_serial_out38x;
+		if (quirks & DW_UART_QUIRK_SKIP_SET_RATE)
+			p->set_termios = dw8250_do_set_termios;
+		if (quirks & DW_UART_QUIRK_IS_DMA_FC) {
+			data->data.dma.txconf.device_fc = 1;
+			data->data.dma.rxconf.device_fc = 1;
+			data->data.dma.prepare_tx_dma = dw8250_prepare_tx_dma;
+			data->data.dma.prepare_rx_dma = dw8250_prepare_rx_dma;
+		}
+
+	} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
+		p->iotype = UPIO_MEM32;
+		p->regshift = 2;
+		p->serial_in = dw8250_serial_in32;
+		data->uart_16550_compatible = true;
+	}
+
+	/* Platforms with iDMA 64-bit */
+	if (platform_get_resource_byname(to_platform_device(p->dev),
+					 IORESOURCE_MEM, "lpss_priv")) {
+		data->data.dma.rx_param = p->dev->parent;
+		data->data.dma.tx_param = p->dev->parent;
+		data->data.dma.fn = dw8250_idma_filter;
+	}
+}
+
+static void dw8250_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static void dw8250_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int dw8250_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port uart = {}, *up = &uart;
+	struct uart_port *p = &up->port;
+	struct device *dev = &pdev->dev;
+	struct dw8250_data *data;
+	struct resource *regs;
+	int irq;
+	int err;
+	u32 val;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs)
+		return dev_err_probe(dev, -EINVAL, "no registers defined\n");
+
+	irq = platform_get_irq_optional(pdev, 0);
+	/* no interrupt -> fall back to polling */
+	if (irq == -ENXIO)
+		irq = 0;
+	if (irq < 0)
+		return irq;
+
+	spin_lock_init(&p->lock);
+	p->mapbase	= regs->start;
+	p->irq		= irq;
+	p->handle_irq	= dw8250_handle_irq;
+	p->pm		= dw8250_do_pm;
+	p->type		= PORT_8250;
+	p->flags	= UPF_SHARE_IRQ | UPF_FIXED_PORT;
+	p->dev		= dev;
+	p->iotype	= UPIO_MEM;
+	p->serial_in	= dw8250_serial_in;
+	p->serial_out	= dw8250_serial_out;
+	p->set_ldisc	= dw8250_set_ldisc;
+	p->set_termios	= dw8250_set_termios;
+
+	p->membase = devm_ioremap(dev, regs->start, resource_size(regs));
+	if (!p->membase)
+		return -ENOMEM;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->data.dma.fn = dw8250_fallback_dma_filter;
+	data->pdata = device_get_match_data(p->dev);
+	p->private_data = &data->data;
+
+	data->uart_16550_compatible = device_property_read_bool(dev,
+						"snps,uart-16550-compatible");
+
+	err = device_property_read_u32(dev, "reg-shift", &val);
+	if (!err)
+		p->regshift = val;
+
+	err = device_property_read_u32(dev, "reg-io-width", &val);
+	if (!err && val == 4) {
+		p->iotype = UPIO_MEM32;
+		p->serial_in = dw8250_serial_in32;
+		p->serial_out = dw8250_serial_out32;
+	}
+
+	if (device_property_read_bool(dev, "dcd-override")) {
+		/* Always report DCD as active */
+		data->msr_mask_on |= UART_MSR_DCD;
+		data->msr_mask_off |= UART_MSR_DDCD;
+	}
+
+	if (device_property_read_bool(dev, "dsr-override")) {
+		/* Always report DSR as active */
+		data->msr_mask_on |= UART_MSR_DSR;
+		data->msr_mask_off |= UART_MSR_DDSR;
+	}
+
+	if (device_property_read_bool(dev, "cts-override")) {
+		/* Always report CTS as active */
+		data->msr_mask_on |= UART_MSR_CTS;
+		data->msr_mask_off |= UART_MSR_DCTS;
+	}
+
+	if (device_property_read_bool(dev, "ri-override")) {
+		/* Always report Ring indicator as inactive */
+		data->msr_mask_off |= UART_MSR_RI;
+		data->msr_mask_off |= UART_MSR_TERI;
+	}
+
+	/* Always ask for fixed clock rate from a property. */
+	device_property_read_u32(dev, "clock-frequency", &p->uartclk);
+
+	/* If there is separate baudclk, get the rate from it. */
+	data->clk = devm_clk_get_optional(dev, "baudclk");
+	if (data->clk == NULL)
+		data->clk = devm_clk_get_optional(dev, NULL);
+	if (IS_ERR(data->clk))
+		return PTR_ERR(data->clk);
+
+	INIT_WORK(&data->clk_work, dw8250_clk_work_cb);
+	data->clk_notifier.notifier_call = dw8250_clk_notifier_cb;
+
+	err = clk_prepare_enable(data->clk);
+	if (err)
+		return dev_err_probe(dev, err, "could not enable optional baudclk\n");
+
+	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->clk);
+	if (err)
+		return err;
+
+	if (data->clk)
+		p->uartclk = clk_get_rate(data->clk);
+
+	/* If no clock rate is defined, fail. */
+	if (!p->uartclk)
+		return dev_err_probe(dev, -EINVAL, "clock rate not defined\n");
+
+	data->pclk = devm_clk_get_optional(dev, "apb_pclk");
+	if (IS_ERR(data->pclk))
+		return PTR_ERR(data->pclk);
+
+	err = clk_prepare_enable(data->pclk);
+	if (err)
+		return dev_err_probe(dev, err, "could not enable apb_pclk\n");
+
+	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->pclk);
+	if (err)
+		return err;
+
+	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(data->rst))
+		return PTR_ERR(data->rst);
+
+	reset_control_deassert(data->rst);
+
+	err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst);
+	if (err)
+		return err;
+
+	dw8250_quirks(p, data);
+
+	/* If the Busy Functionality is not implemented, don't handle it */
+	if (data->uart_16550_compatible)
+		p->handle_irq = NULL;
+
+	if (!data->skip_autocfg)
+		dw8250_setup_port(p);
+
+	/* If we have a valid fifosize, try hooking up DMA */
+	if (p->fifosize) {
+		data->data.dma.rxconf.src_maxburst = p->fifosize / 4;
+		data->data.dma.txconf.dst_maxburst = p->fifosize / 4;
+		up->dma = &data->data.dma;
+	}
+
+	data->data.line = serial8250_register_8250_port(up);
+	if (data->data.line < 0)
+		return data->data.line;
+
+	/*
+	 * Some platforms may provide a reference clock shared between several
+	 * devices. In this case any clock state change must be known to the
+	 * UART port at least post factum.
+	 */
+	if (data->clk) {
+		err = clk_notifier_register(data->clk, &data->clk_notifier);
+		if (err)
+			return dev_err_probe(dev, err, "Failed to set the clock notifier\n");
+		queue_work(system_unbound_wq, &data->clk_work);
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static int dw8250_remove(struct platform_device *pdev)
+{
+	struct dw8250_data *data = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_get_sync(dev);
+
+	if (data->clk) {
+		clk_notifier_unregister(data->clk, &data->clk_notifier);
+
+		flush_work(&data->clk_work);
+	}
+
+	serial8250_unregister_port(data->data.line);
+
+	pm_runtime_disable(dev);
+	pm_runtime_put_noidle(dev);
+
+	return 0;
+}
+
+static int dw8250_suspend(struct device *dev)
+{
+	struct dw8250_data *data = dev_get_drvdata(dev);
+
+	serial8250_suspend_port(data->data.line);
+
+	return 0;
+}
+
+static int dw8250_resume(struct device *dev)
+{
+	struct dw8250_data *data = dev_get_drvdata(dev);
+
+	serial8250_resume_port(data->data.line);
+
+	return 0;
+}
+
+static int dw8250_runtime_suspend(struct device *dev)
+{
+	struct dw8250_data *data = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(data->clk);
+
+	clk_disable_unprepare(data->pclk);
+
+	return 0;
+}
+
+static int dw8250_runtime_resume(struct device *dev)
+{
+	struct dw8250_data *data = dev_get_drvdata(dev);
+
+	clk_prepare_enable(data->pclk);
+
+	clk_prepare_enable(data->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops dw8250_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
+	RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
+};
+
+static const struct dw8250_platform_data dw8250_dw_apb = {
+	.usr_reg = DW_UART_USR,
+};
+
+static const struct dw8250_platform_data dw8250_octeon_3860_data = {
+	.usr_reg = OCTEON_UART_USR,
+	.quirks = DW_UART_QUIRK_OCTEON,
+};
+
+static const struct dw8250_platform_data dw8250_armada_38x_data = {
+	.usr_reg = DW_UART_USR,
+	.quirks = DW_UART_QUIRK_ARMADA_38X,
+};
+
+static const struct dw8250_platform_data dw8250_renesas_rzn1_data = {
+	.usr_reg = DW_UART_USR,
+	.cpr_val = 0x00012f32,
+	.quirks = DW_UART_QUIRK_IS_DMA_FC,
+};
+
+static const struct dw8250_platform_data dw8250_starfive_jh7100_data = {
+	.usr_reg = DW_UART_USR,
+	.quirks = DW_UART_QUIRK_SKIP_SET_RATE,
+};
+
+static const struct of_device_id dw8250_of_match[] = {
+	{ .compatible = "snps,dw-apb-uart", .data = &dw8250_dw_apb },
+	{ .compatible = "cavium,octeon-3860-uart", .data = &dw8250_octeon_3860_data },
+	{ .compatible = "marvell,armada-38x-uart", .data = &dw8250_armada_38x_data },
+	{ .compatible = "renesas,rzn1-uart", .data = &dw8250_renesas_rzn1_data },
+	{ .compatible = "starfive,jh7100-uart", .data = &dw8250_starfive_jh7100_data },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dw8250_of_match);
+
+static const struct acpi_device_id dw8250_acpi_match[] = {
+	{ "80860F0A", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "8086228A", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "AMD0020", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "AMDI0020", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "AMDI0022", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "APMC0D08", (kernel_ulong_t)&dw8250_dw_apb},
+	{ "BRCM2032", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "HISI0031", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT33C4", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT33C5", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT3434", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT3435", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INTC10EE", (kernel_ulong_t)&dw8250_dw_apb },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);
+
+static struct platform_driver dw8250_platform_driver = {
+	.driver = {
+		.name		= "dw-apb-uart",
+		.pm		= pm_ptr(&dw8250_pm_ops),
+		.of_match_table	= dw8250_of_match,
+		.acpi_match_table = dw8250_acpi_match,
+	},
+	.probe			= dw8250_probe,
+	.remove			= dw8250_remove,
+};
+
+module_platform_driver(dw8250_platform_driver);
+
+MODULE_AUTHOR("Jamie Iles");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver");
+MODULE_ALIAS("platform:dw-apb-uart");
diff --git a/drivers/tty/serial/8250/8250_dwlib.c b/drivers/tty/serial/8250/8250_dwlib.c
new file mode 100644
index 000000000..84843e204
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dwlib.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Synopsys DesignWare 8250 library. */
+
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/math.h>
+#include <linux/property.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+
+#include "8250_dwlib.h"
+
+/* Offsets for the DesignWare specific registers */
+#define DW_UART_TCR	0xac /* Transceiver Control Register (RS485) */
+#define DW_UART_DE_EN	0xb0 /* Driver Output Enable Register */
+#define DW_UART_RE_EN	0xb4 /* Receiver Output Enable Register */
+#define DW_UART_DLF	0xc0 /* Divisor Latch Fraction Register */
+#define DW_UART_RAR	0xc4 /* Receive Address Register */
+#define DW_UART_TAR	0xc8 /* Transmit Address Register */
+#define DW_UART_LCR_EXT	0xcc /* Line Extended Control Register */
+#define DW_UART_CPR	0xf4 /* Component Parameter Register */
+#define DW_UART_UCV	0xf8 /* UART Component Version */
+
+/* Receive / Transmit Address Register bits */
+#define DW_UART_ADDR_MASK		GENMASK(7, 0)
+
+/* Line Status Register bits */
+#define DW_UART_LSR_ADDR_RCVD		BIT(8)
+
+/* Transceiver Control Register bits */
+#define DW_UART_TCR_RS485_EN		BIT(0)
+#define DW_UART_TCR_RE_POL		BIT(1)
+#define DW_UART_TCR_DE_POL		BIT(2)
+#define DW_UART_TCR_XFER_MODE		GENMASK(4, 3)
+#define DW_UART_TCR_XFER_MODE_DE_DURING_RE	FIELD_PREP(DW_UART_TCR_XFER_MODE, 0)
+#define DW_UART_TCR_XFER_MODE_SW_DE_OR_RE	FIELD_PREP(DW_UART_TCR_XFER_MODE, 1)
+#define DW_UART_TCR_XFER_MODE_DE_OR_RE		FIELD_PREP(DW_UART_TCR_XFER_MODE, 2)
+
+/* Line Extended Control Register bits */
+#define DW_UART_LCR_EXT_DLS_E		BIT(0)
+#define DW_UART_LCR_EXT_ADDR_MATCH	BIT(1)
+#define DW_UART_LCR_EXT_SEND_ADDR	BIT(2)
+#define DW_UART_LCR_EXT_TRANSMIT_MODE	BIT(3)
+
+/* Component Parameter Register bits */
+#define DW_UART_CPR_ABP_DATA_WIDTH	GENMASK(1, 0)
+#define DW_UART_CPR_AFCE_MODE		BIT(4)
+#define DW_UART_CPR_THRE_MODE		BIT(5)
+#define DW_UART_CPR_SIR_MODE		BIT(6)
+#define DW_UART_CPR_SIR_LP_MODE		BIT(7)
+#define DW_UART_CPR_ADDITIONAL_FEATURES	BIT(8)
+#define DW_UART_CPR_FIFO_ACCESS		BIT(9)
+#define DW_UART_CPR_FIFO_STAT		BIT(10)
+#define DW_UART_CPR_SHADOW		BIT(11)
+#define DW_UART_CPR_ENCODED_PARMS	BIT(12)
+#define DW_UART_CPR_DMA_EXTRA		BIT(13)
+#define DW_UART_CPR_FIFO_MODE		GENMASK(23, 16)
+
+/* Helper for FIFO size calculation */
+#define DW_UART_CPR_FIFO_SIZE(a)	(FIELD_GET(DW_UART_CPR_FIFO_MODE, (a)) * 16)
+
+/*
+ * divisor = div(I) + div(F)
+ * "I" means integer, "F" means fractional
+ * quot = div(I) = clk / (16 * baud)
+ * frac = div(F) * 2^dlf_size
+ *
+ * let rem = clk % (16 * baud)
+ * we have: div(F) * (16 * baud) = rem
+ * so frac = 2^dlf_size * rem / (16 * baud) = (rem << dlf_size) / (16 * baud)
+ */
+static unsigned int dw8250_get_divisor(struct uart_port *p, unsigned int baud,
+				       unsigned int *frac)
+{
+	unsigned int quot, rem, base_baud = baud * 16;
+	struct dw8250_port_data *d = p->private_data;
+
+	quot = p->uartclk / base_baud;
+	rem = p->uartclk % base_baud;
+	*frac = DIV_ROUND_CLOSEST(rem << d->dlf_size, base_baud);
+
+	return quot;
+}
+
+static void dw8250_set_divisor(struct uart_port *p, unsigned int baud,
+			       unsigned int quot, unsigned int quot_frac)
+{
+	dw8250_writel_ext(p, DW_UART_DLF, quot_frac);
+	serial8250_do_set_divisor(p, baud, quot, quot_frac);
+}
+
+void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios,
+			   const struct ktermios *old)
+{
+	p->status &= ~UPSTAT_AUTOCTS;
+	if (termios->c_cflag & CRTSCTS)
+		p->status |= UPSTAT_AUTOCTS;
+
+	serial8250_do_set_termios(p, termios, old);
+
+	/* Filter addresses which have 9th bit set */
+	p->ignore_status_mask |= DW_UART_LSR_ADDR_RCVD;
+	p->read_status_mask |= DW_UART_LSR_ADDR_RCVD;
+}
+EXPORT_SYMBOL_GPL(dw8250_do_set_termios);
+
+/*
+ * Wait until re is de-asserted for sure. An ongoing receive will keep
+ * re asserted until end of frame. Without BUSY indication available,
+ * only available course of action is to wait for the time it takes to
+ * receive one frame (there might nothing to receive but w/o BUSY the
+ * driver cannot know).
+ */
+static void dw8250_wait_re_deassert(struct uart_port *p)
+{
+	ndelay(p->frame_time);
+}
+
+static void dw8250_update_rar(struct uart_port *p, u32 addr)
+{
+	u32 re_en = dw8250_readl_ext(p, DW_UART_RE_EN);
+
+	/*
+	 * RAR shouldn't be changed while receiving. Thus, de-assert RE_EN
+	 * if asserted and wait.
+	 */
+	if (re_en)
+		dw8250_writel_ext(p, DW_UART_RE_EN, 0);
+	dw8250_wait_re_deassert(p);
+	dw8250_writel_ext(p, DW_UART_RAR, addr);
+	if (re_en)
+		dw8250_writel_ext(p, DW_UART_RE_EN, re_en);
+}
+
+static void dw8250_rs485_set_addr(struct uart_port *p, struct serial_rs485 *rs485,
+				  struct ktermios *termios)
+{
+	u32 lcr = dw8250_readl_ext(p, DW_UART_LCR_EXT);
+
+	if (rs485->flags & SER_RS485_ADDRB) {
+		lcr |= DW_UART_LCR_EXT_DLS_E;
+		if (termios)
+			termios->c_cflag |= ADDRB;
+
+		if (rs485->flags & SER_RS485_ADDR_RECV) {
+			u32 delta = p->rs485.flags ^ rs485->flags;
+
+			/*
+			 * rs485 (param) is equal to uart_port's rs485 only during init
+			 * (during init, delta is not yet applicable).
+			 */
+			if (unlikely(&p->rs485 == rs485))
+				delta = rs485->flags;
+
+			if ((delta & SER_RS485_ADDR_RECV) ||
+			    (p->rs485.addr_recv != rs485->addr_recv))
+				dw8250_update_rar(p, rs485->addr_recv);
+			lcr |= DW_UART_LCR_EXT_ADDR_MATCH;
+		} else {
+			lcr &= ~DW_UART_LCR_EXT_ADDR_MATCH;
+		}
+		if (rs485->flags & SER_RS485_ADDR_DEST) {
+			/*
+			 * Don't skip writes here as another endpoint could
+			 * have changed communication line's destination
+			 * address in between.
+			 */
+			dw8250_writel_ext(p, DW_UART_TAR, rs485->addr_dest);
+			lcr |= DW_UART_LCR_EXT_SEND_ADDR;
+		}
+	} else {
+		lcr = 0;
+	}
+	dw8250_writel_ext(p, DW_UART_LCR_EXT, lcr);
+}
+
+static int dw8250_rs485_config(struct uart_port *p, struct ktermios *termios,
+			       struct serial_rs485 *rs485)
+{
+	u32 tcr;
+
+	tcr = dw8250_readl_ext(p, DW_UART_TCR);
+	tcr &= ~DW_UART_TCR_XFER_MODE;
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		tcr |= DW_UART_TCR_RS485_EN;
+
+		if (rs485->flags & SER_RS485_RX_DURING_TX)
+			tcr |= DW_UART_TCR_XFER_MODE_DE_DURING_RE;
+		else
+			tcr |= DW_UART_TCR_XFER_MODE_DE_OR_RE;
+		dw8250_writel_ext(p, DW_UART_DE_EN, 1);
+		dw8250_writel_ext(p, DW_UART_RE_EN, 1);
+	} else {
+		if (termios)
+			termios->c_cflag &= ~ADDRB;
+
+		tcr &= ~DW_UART_TCR_RS485_EN;
+	}
+
+	/* Reset to default polarity */
+	tcr |= DW_UART_TCR_DE_POL;
+	tcr &= ~DW_UART_TCR_RE_POL;
+
+	if (!(rs485->flags & SER_RS485_RTS_ON_SEND))
+		tcr &= ~DW_UART_TCR_DE_POL;
+	if (device_property_read_bool(p->dev, "rs485-rx-active-high"))
+		tcr |= DW_UART_TCR_RE_POL;
+
+	dw8250_writel_ext(p, DW_UART_TCR, tcr);
+
+	/* Addressing mode can only be set up after TCR */
+	if (rs485->flags & SER_RS485_ENABLED)
+		dw8250_rs485_set_addr(p, rs485, termios);
+
+	return 0;
+}
+
+/*
+ * Tests if RE_EN register can have non-zero value to see if RS-485 HW support
+ * is present.
+ */
+static bool dw8250_detect_rs485_hw(struct uart_port *p)
+{
+	u32 reg;
+
+	dw8250_writel_ext(p, DW_UART_RE_EN, 1);
+	reg = dw8250_readl_ext(p, DW_UART_RE_EN);
+	dw8250_writel_ext(p, DW_UART_RE_EN, 0);
+	return reg;
+}
+
+static const struct serial_rs485 dw8250_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX | SER_RS485_RTS_ON_SEND |
+		 SER_RS485_RTS_AFTER_SEND | SER_RS485_ADDRB | SER_RS485_ADDR_RECV |
+		 SER_RS485_ADDR_DEST,
+};
+
+void dw8250_setup_port(struct uart_port *p)
+{
+	struct dw8250_port_data *pd = p->private_data;
+	struct dw8250_data *data = to_dw8250_data(pd);
+	struct uart_8250_port *up = up_to_u8250p(p);
+	u32 reg, old_dlf;
+
+	pd->hw_rs485_support = dw8250_detect_rs485_hw(p);
+	if (pd->hw_rs485_support) {
+		p->rs485_config = dw8250_rs485_config;
+		up->lsr_save_mask = LSR_SAVE_FLAGS | DW_UART_LSR_ADDR_RCVD;
+		p->rs485_supported = dw8250_rs485_supported;
+	} else {
+		p->rs485_config = serial8250_em485_config;
+		p->rs485_supported = serial8250_em485_supported;
+		up->rs485_start_tx = serial8250_em485_start_tx;
+		up->rs485_stop_tx = serial8250_em485_stop_tx;
+	}
+	up->capabilities |= UART_CAP_NOTEMT;
+
+	/*
+	 * If the Component Version Register returns zero, we know that
+	 * ADDITIONAL_FEATURES are not enabled. No need to go any further.
+	 */
+	reg = dw8250_readl_ext(p, DW_UART_UCV);
+	if (!reg)
+		return;
+
+	dev_dbg(p->dev, "Designware UART version %c.%c%c\n",
+		(reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff);
+
+	/* Preserve value written by firmware or bootloader  */
+	old_dlf = dw8250_readl_ext(p, DW_UART_DLF);
+	dw8250_writel_ext(p, DW_UART_DLF, ~0U);
+	reg = dw8250_readl_ext(p, DW_UART_DLF);
+	dw8250_writel_ext(p, DW_UART_DLF, old_dlf);
+
+	if (reg) {
+		pd->dlf_size = fls(reg);
+		p->get_divisor = dw8250_get_divisor;
+		p->set_divisor = dw8250_set_divisor;
+	}
+
+	reg = dw8250_readl_ext(p, DW_UART_CPR);
+	if (!reg) {
+		reg = data->pdata->cpr_val;
+		dev_dbg(p->dev, "CPR is not available, using 0x%08x instead\n", reg);
+	}
+	if (!reg)
+		return;
+
+	/* Select the type based on FIFO */
+	if (reg & DW_UART_CPR_FIFO_MODE) {
+		p->type = PORT_16550A;
+		p->flags |= UPF_FIXED_TYPE;
+		p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
+		up->capabilities = UART_CAP_FIFO | UART_CAP_NOTEMT;
+	}
+
+	if (reg & DW_UART_CPR_AFCE_MODE)
+		up->capabilities |= UART_CAP_AFE;
+
+	if (reg & DW_UART_CPR_SIR_MODE)
+		up->capabilities |= UART_CAP_IRDA;
+}
+EXPORT_SYMBOL_GPL(dw8250_setup_port);
diff --git a/drivers/tty/serial/8250/8250_dwlib.h b/drivers/tty/serial/8250/8250_dwlib.h
new file mode 100644
index 000000000..f13e91f2c
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dwlib.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Synopsys DesignWare 8250 library header file. */
+
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include "8250.h"
+
+struct clk;
+struct reset_control;
+
+struct dw8250_port_data {
+	/* Port properties */
+	int			line;
+
+	/* DMA operations */
+	struct uart_8250_dma	dma;
+
+	/* Hardware configuration */
+	u8			dlf_size;
+
+	/* RS485 variables */
+	bool			hw_rs485_support;
+};
+
+struct dw8250_platform_data {
+	u8 usr_reg;
+	u32 cpr_val;
+	unsigned int quirks;
+};
+
+struct dw8250_data {
+	struct dw8250_port_data	data;
+	const struct dw8250_platform_data *pdata;
+
+	int			msr_mask_on;
+	int			msr_mask_off;
+	struct clk		*clk;
+	struct clk		*pclk;
+	struct notifier_block	clk_notifier;
+	struct work_struct	clk_work;
+	struct reset_control	*rst;
+
+	unsigned int		skip_autocfg:1;
+	unsigned int		uart_16550_compatible:1;
+};
+
+void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, const struct ktermios *old);
+void dw8250_setup_port(struct uart_port *p);
+
+static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
+{
+	return container_of(data, struct dw8250_data, data);
+}
+
+static inline u32 dw8250_readl_ext(struct uart_port *p, int offset)
+{
+	if (p->iotype == UPIO_MEM32BE)
+		return ioread32be(p->membase + offset);
+	return readl(p->membase + offset);
+}
+
+static inline void dw8250_writel_ext(struct uart_port *p, int offset, u32 reg)
+{
+	if (p->iotype == UPIO_MEM32BE)
+		iowrite32be(reg, p->membase + offset);
+	else
+		writel(reg, p->membase + offset);
+}
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
new file mode 100644
index 000000000..e3f482fd3
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Early serial console for 8250/16550 devices
+ *
+ * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * Based on the 8250.c serial driver, Copyright (C) 2001 Russell King,
+ * and on early_printk.c by Andi Kleen.
+ *
+ * This is for use before the serial driver has initialized, in
+ * particular, before the UARTs have been discovered and named.
+ * Instead of specifying the console device as, e.g., "ttyS0",
+ * we locate the device directly by its MMIO or I/O port address.
+ *
+ * The user can specify the device directly, e.g.,
+ *	earlycon=uart8250,io,0x3f8,9600n8
+ *	earlycon=uart8250,mmio,0xff5e0000,115200n8
+ *	earlycon=uart8250,mmio32,0xff5e0000,115200n8
+ * or
+ *	console=uart8250,io,0x3f8,9600n8
+ *	console=uart8250,mmio,0xff5e0000,115200n8
+ *	console=uart8250,mmio32,0xff5e0000,115200n8
+ */
+
+#include <linux/tty.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/of.h>
+#include <linux/serial_reg.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <asm/io.h>
+#include <asm/serial.h>
+
+static unsigned int serial8250_early_in(struct uart_port *port, int offset)
+{
+	offset <<= port->regshift;
+
+	switch (port->iotype) {
+	case UPIO_MEM:
+		return readb(port->membase + offset);
+	case UPIO_MEM16:
+		return readw(port->membase + offset);
+	case UPIO_MEM32:
+		return readl(port->membase + offset);
+	case UPIO_MEM32BE:
+		return ioread32be(port->membase + offset);
+	case UPIO_PORT:
+		return inb(port->iobase + offset);
+	default:
+		return 0;
+	}
+}
+
+static void serial8250_early_out(struct uart_port *port, int offset, int value)
+{
+	offset <<= port->regshift;
+
+	switch (port->iotype) {
+	case UPIO_MEM:
+		writeb(value, port->membase + offset);
+		break;
+	case UPIO_MEM16:
+		writew(value, port->membase + offset);
+		break;
+	case UPIO_MEM32:
+		writel(value, port->membase + offset);
+		break;
+	case UPIO_MEM32BE:
+		iowrite32be(value, port->membase + offset);
+		break;
+	case UPIO_PORT:
+		outb(value, port->iobase + offset);
+		break;
+	}
+}
+
+static void serial_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned int status;
+
+	serial8250_early_out(port, UART_TX, c);
+
+	for (;;) {
+		status = serial8250_early_in(port, UART_LSR);
+		if (uart_lsr_tx_empty(status))
+			break;
+		cpu_relax();
+	}
+}
+
+static void early_serial8250_write(struct console *console,
+					const char *s, unsigned int count)
+{
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+
+	uart_console_write(port, s, count, serial_putc);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int early_serial8250_read(struct console *console,
+				 char *s, unsigned int count)
+{
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+	unsigned int status;
+	int num_read = 0;
+
+	while (num_read < count) {
+		status = serial8250_early_in(port, UART_LSR);
+		if (!(status & UART_LSR_DR))
+			break;
+		s[num_read++] = serial8250_early_in(port, UART_RX);
+	}
+
+	return num_read;
+}
+#else
+#define early_serial8250_read NULL
+#endif
+
+static void __init init_port(struct earlycon_device *device)
+{
+	struct uart_port *port = &device->port;
+	unsigned int divisor;
+	unsigned char c;
+	unsigned int ier;
+
+	serial8250_early_out(port, UART_LCR, UART_LCR_WLEN8);		/* 8n1 */
+	ier = serial8250_early_in(port, UART_IER);
+	serial8250_early_out(port, UART_IER, ier & UART_IER_UUE); /* no interrupt */
+	serial8250_early_out(port, UART_FCR, 0);	/* no fifo */
+	serial8250_early_out(port, UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
+
+	if (port->uartclk) {
+		divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * device->baud);
+		c = serial8250_early_in(port, UART_LCR);
+		serial8250_early_out(port, UART_LCR, c | UART_LCR_DLAB);
+		serial8250_early_out(port, UART_DLL, divisor & 0xff);
+		serial8250_early_out(port, UART_DLM, (divisor >> 8) & 0xff);
+		serial8250_early_out(port, UART_LCR, c & ~UART_LCR_DLAB);
+	}
+}
+
+int __init early_serial8250_setup(struct earlycon_device *device,
+					 const char *options)
+{
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+
+	if (!device->baud) {
+		struct uart_port *port = &device->port;
+		unsigned int ier;
+
+		/* assume the device was initialized, only mask interrupts */
+		ier = serial8250_early_in(port, UART_IER);
+		serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
+	} else
+		init_port(device);
+
+	device->con->write = early_serial8250_write;
+	device->con->read = early_serial8250_read;
+	return 0;
+}
+EARLYCON_DECLARE(uart8250, early_serial8250_setup);
+EARLYCON_DECLARE(uart, early_serial8250_setup);
+OF_EARLYCON_DECLARE(ns16550, "ns16550", early_serial8250_setup);
+OF_EARLYCON_DECLARE(ns16550a, "ns16550a", early_serial8250_setup);
+OF_EARLYCON_DECLARE(uart, "nvidia,tegra20-uart", early_serial8250_setup);
+OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup);
+
+#ifdef CONFIG_SERIAL_8250_OMAP
+
+static int __init early_omap8250_setup(struct earlycon_device *device,
+				       const char *options)
+{
+	struct uart_port *port = &device->port;
+
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+
+	port->regshift = 2;
+	device->con->write = early_serial8250_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(omap8250, "ti,omap2-uart", early_omap8250_setup);
+OF_EARLYCON_DECLARE(omap8250, "ti,omap3-uart", early_omap8250_setup);
+OF_EARLYCON_DECLARE(omap8250, "ti,omap4-uart", early_omap8250_setup);
+OF_EARLYCON_DECLARE(omap8250, "ti,am654-uart", early_omap8250_setup);
+
+#endif
diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c
new file mode 100644
index 000000000..ef5019e94
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_em.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas Emma Mobile 8250 driver
+ *
+ *  Copyright (C) 2012 Magnus Damm
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include "8250.h"
+
+#define UART_DLL_EM 9
+#define UART_DLM_EM 10
+#define UART_HCR0_EM 11
+
+/*
+ * A high value for UART_FCR_EM avoids overlapping with existing UART_*
+ * register defines. UART_FCR_EM_HW is the real HW register offset.
+ */
+#define UART_FCR_EM 0x10003
+#define UART_FCR_EM_HW 3
+
+#define UART_HCR0_EM_SW_RESET	BIT(7) /* SW Reset */
+
+struct serial8250_em_priv {
+	int line;
+};
+
+static void serial8250_em_serial_out_helper(struct uart_port *p, int offset,
+					    int value)
+{
+	switch (offset) {
+	case UART_TX: /* TX @ 0x00 */
+		writeb(value, p->membase);
+		break;
+	case UART_LCR: /* LCR @ 0x10 (+1) */
+	case UART_MCR: /* MCR @ 0x14 (+1) */
+	case UART_SCR: /* SCR @ 0x20 (+1) */
+		writel(value, p->membase + ((offset + 1) << 2));
+		break;
+	case UART_FCR_EM:
+		writel(value, p->membase + (UART_FCR_EM_HW << 2));
+		break;
+	case UART_IER: /* IER @ 0x04 */
+		value &= 0x0f; /* only 4 valid bits - not Xscale */
+		fallthrough;
+	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
+	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+	case UART_HCR0_EM: /* HCR0 @ 0x2c */
+		writel(value, p->membase + (offset << 2));
+		break;
+	}
+}
+
+static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
+{
+	switch (offset) {
+	case UART_RX: /* RX @ 0x00 */
+		return readb(p->membase);
+	case UART_LCR: /* LCR @ 0x10 (+1) */
+	case UART_MCR: /* MCR @ 0x14 (+1) */
+	case UART_LSR: /* LSR @ 0x18 (+1) */
+	case UART_MSR: /* MSR @ 0x1c (+1) */
+	case UART_SCR: /* SCR @ 0x20 (+1) */
+		return readl(p->membase + ((offset + 1) << 2));
+	case UART_FCR_EM:
+		return readl(p->membase + (UART_FCR_EM_HW << 2));
+	case UART_IER: /* IER @ 0x04 */
+	case UART_IIR: /* IIR @ 0x08 */
+	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
+	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+	case UART_HCR0_EM: /* HCR0 @ 0x2c */
+		return readl(p->membase + (offset << 2));
+	}
+	return 0;
+}
+
+static void serial8250_em_reg_update(struct uart_port *p, int off, int value)
+{
+	unsigned int ier, fcr, lcr, mcr, hcr0;
+
+	ier = serial8250_em_serial_in(p, UART_IER);
+	fcr = serial8250_em_serial_in(p, UART_FCR_EM);
+	lcr = serial8250_em_serial_in(p, UART_LCR);
+	mcr = serial8250_em_serial_in(p, UART_MCR);
+	hcr0 = serial8250_em_serial_in(p, UART_HCR0_EM);
+
+	serial8250_em_serial_out_helper(p, UART_FCR_EM, fcr |
+							UART_FCR_CLEAR_RCVR |
+							UART_FCR_CLEAR_XMIT);
+	serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0 |
+							 UART_HCR0_EM_SW_RESET);
+	serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0 &
+							 ~UART_HCR0_EM_SW_RESET);
+
+	switch (off) {
+	case UART_FCR_EM:
+		fcr = value;
+		break;
+	case UART_LCR:
+		lcr = value;
+		break;
+	case UART_MCR:
+		mcr = value;
+		break;
+	}
+
+	serial8250_em_serial_out_helper(p, UART_IER, ier);
+	serial8250_em_serial_out_helper(p, UART_FCR_EM, fcr);
+	serial8250_em_serial_out_helper(p, UART_MCR, mcr);
+	serial8250_em_serial_out_helper(p, UART_LCR, lcr);
+	serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0);
+}
+
+static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
+{
+	switch (offset) {
+	case UART_TX:
+	case UART_SCR:
+	case UART_IER:
+	case UART_DLL_EM:
+	case UART_DLM_EM:
+		serial8250_em_serial_out_helper(p, offset, value);
+		break;
+	case UART_FCR:
+		serial8250_em_reg_update(p, UART_FCR_EM, value);
+		break;
+	case UART_LCR:
+	case UART_MCR:
+		serial8250_em_reg_update(p, offset, value);
+		break;
+	}
+}
+
+static u32 serial8250_em_serial_dl_read(struct uart_8250_port *up)
+{
+	return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
+}
+
+static void serial8250_em_serial_dl_write(struct uart_8250_port *up, u32 value)
+{
+	serial_out(up, UART_DLL_EM, value & 0xff);
+	serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
+}
+
+static int serial8250_em_probe(struct platform_device *pdev)
+{
+	struct serial8250_em_priv *priv;
+	struct device *dev = &pdev->dev;
+	struct uart_8250_port up;
+	struct resource *regs;
+	struct clk *sclk;
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs)
+		return dev_err_probe(dev, -EINVAL, "missing registers\n");
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	sclk = devm_clk_get_enabled(dev, "sclk");
+	if (IS_ERR(sclk))
+		return dev_err_probe(dev, PTR_ERR(sclk), "unable to get clock\n");
+
+	memset(&up, 0, sizeof(up));
+	up.port.mapbase = regs->start;
+	up.port.irq = irq;
+	up.port.type = PORT_16750;
+	up.port.flags = UPF_FIXED_PORT | UPF_IOREMAP | UPF_FIXED_TYPE;
+	up.port.dev = dev;
+	up.port.private_data = priv;
+
+	up.port.uartclk = clk_get_rate(sclk);
+
+	up.port.iotype = UPIO_MEM32;
+	up.port.serial_in = serial8250_em_serial_in;
+	up.port.serial_out = serial8250_em_serial_out;
+	up.dl_read = serial8250_em_serial_dl_read;
+	up.dl_write = serial8250_em_serial_dl_write;
+
+	ret = serial8250_register_8250_port(&up);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "unable to register 8250 port\n");
+
+	priv->line = ret;
+	platform_set_drvdata(pdev, priv);
+	return 0;
+}
+
+static int serial8250_em_remove(struct platform_device *pdev)
+{
+	struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(priv->line);
+	return 0;
+}
+
+static const struct of_device_id serial8250_em_dt_ids[] = {
+	{ .compatible = "renesas,em-uart", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
+
+static struct platform_driver serial8250_em_platform_driver = {
+	.driver = {
+		.name		= "serial8250-em",
+		.of_match_table = serial8250_em_dt_ids,
+	},
+	.probe			= serial8250_em_probe,
+	.remove			= serial8250_em_remove,
+};
+
+module_platform_driver(serial8250_em_platform_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
new file mode 100644
index 000000000..8385be846
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -0,0 +1,920 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Probe module for 8250/16550-type Exar chips PCI serial ports.
+ *
+ *  Based on drivers/tty/serial/8250/8250_pci.c,
+ *
+ *  Copyright (C) 2017 Sudip Mukherjee, All Rights Reserved.
+ */
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/property.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tty.h>
+#include <linux/8250_pci.h>
+#include <linux/delay.h>
+
+#include <asm/byteorder.h>
+
+#include "8250.h"
+
+#define PCI_DEVICE_ID_ACCESSIO_COM_2S		0x1052
+#define PCI_DEVICE_ID_ACCESSIO_COM_4S		0x105d
+#define PCI_DEVICE_ID_ACCESSIO_COM_8S		0x106c
+#define PCI_DEVICE_ID_ACCESSIO_COM232_8		0x10a8
+#define PCI_DEVICE_ID_ACCESSIO_COM_2SM		0x10d2
+#define PCI_DEVICE_ID_ACCESSIO_COM_4SM		0x10db
+#define PCI_DEVICE_ID_ACCESSIO_COM_8SM		0x10ea
+
+#define PCI_DEVICE_ID_COMMTECH_4224PCI335	0x0002
+#define PCI_DEVICE_ID_COMMTECH_4222PCI335	0x0004
+#define PCI_DEVICE_ID_COMMTECH_2324PCI335	0x000a
+#define PCI_DEVICE_ID_COMMTECH_2328PCI335	0x000b
+#define PCI_DEVICE_ID_COMMTECH_4224PCIE		0x0020
+#define PCI_DEVICE_ID_COMMTECH_4228PCIE		0x0021
+#define PCI_DEVICE_ID_COMMTECH_4222PCIE		0x0022
+
+#define PCI_DEVICE_ID_EXAR_XR17V4358		0x4358
+#define PCI_DEVICE_ID_EXAR_XR17V8358		0x8358
+
+#define PCI_SUBDEVICE_ID_USR_2980		0x0128
+#define PCI_SUBDEVICE_ID_USR_2981		0x0129
+
+#define PCI_DEVICE_ID_SEALEVEL_710xC		0x1001
+#define PCI_DEVICE_ID_SEALEVEL_720xC		0x1002
+#define PCI_DEVICE_ID_SEALEVEL_740xC		0x1004
+#define PCI_DEVICE_ID_SEALEVEL_780xC		0x1008
+#define PCI_DEVICE_ID_SEALEVEL_716xC		0x1010
+
+#define UART_EXAR_INT0		0x80
+#define UART_EXAR_8XMODE	0x88	/* 8X sampling rate select */
+#define UART_EXAR_SLEEP		0x8b	/* Sleep mode */
+#define UART_EXAR_DVID		0x8d	/* Device identification */
+
+#define UART_EXAR_FCTR		0x08	/* Feature Control Register */
+#define UART_FCTR_EXAR_IRDA	0x10	/* IrDa data encode select */
+#define UART_FCTR_EXAR_485	0x20	/* Auto 485 half duplex dir ctl */
+#define UART_FCTR_EXAR_TRGA	0x00	/* FIFO trigger table A */
+#define UART_FCTR_EXAR_TRGB	0x60	/* FIFO trigger table B */
+#define UART_FCTR_EXAR_TRGC	0x80	/* FIFO trigger table C */
+#define UART_FCTR_EXAR_TRGD	0xc0	/* FIFO trigger table D programmable */
+
+#define UART_EXAR_TXTRG		0x0a	/* Tx FIFO trigger level write-only */
+#define UART_EXAR_RXTRG		0x0b	/* Rx FIFO trigger level write-only */
+
+#define UART_EXAR_MPIOINT_7_0	0x8f	/* MPIOINT[7:0] */
+#define UART_EXAR_MPIOLVL_7_0	0x90	/* MPIOLVL[7:0] */
+#define UART_EXAR_MPIO3T_7_0	0x91	/* MPIO3T[7:0] */
+#define UART_EXAR_MPIOINV_7_0	0x92	/* MPIOINV[7:0] */
+#define UART_EXAR_MPIOSEL_7_0	0x93	/* MPIOSEL[7:0] */
+#define UART_EXAR_MPIOOD_7_0	0x94	/* MPIOOD[7:0] */
+#define UART_EXAR_MPIOINT_15_8	0x95	/* MPIOINT[15:8] */
+#define UART_EXAR_MPIOLVL_15_8	0x96	/* MPIOLVL[15:8] */
+#define UART_EXAR_MPIO3T_15_8	0x97	/* MPIO3T[15:8] */
+#define UART_EXAR_MPIOINV_15_8	0x98	/* MPIOINV[15:8] */
+#define UART_EXAR_MPIOSEL_15_8	0x99	/* MPIOSEL[15:8] */
+#define UART_EXAR_MPIOOD_15_8	0x9a	/* MPIOOD[15:8] */
+
+#define UART_EXAR_RS485_DLY(x)	((x) << 4)
+
+/*
+ * IOT2040 MPIO wiring semantics:
+ *
+ * MPIO		Port	Function
+ * ----		----	--------
+ * 0		2 	Mode bit 0
+ * 1		2	Mode bit 1
+ * 2		2	Terminate bus
+ * 3		-	<reserved>
+ * 4		3	Mode bit 0
+ * 5		3	Mode bit 1
+ * 6		3	Terminate bus
+ * 7		-	<reserved>
+ * 8		2	Enable
+ * 9		3	Enable
+ * 10		-	Red LED
+ * 11..15	-	<unused>
+ */
+
+/* IOT2040 MPIOs 0..7 */
+#define IOT2040_UART_MODE_RS232		0x01
+#define IOT2040_UART_MODE_RS485		0x02
+#define IOT2040_UART_MODE_RS422		0x03
+#define IOT2040_UART_TERMINATE_BUS	0x04
+
+#define IOT2040_UART1_MASK		0x0f
+#define IOT2040_UART2_SHIFT		4
+
+#define IOT2040_UARTS_DEFAULT_MODE	0x11	/* both RS232 */
+#define IOT2040_UARTS_GPIO_LO_MODE	0x88	/* reserved pins as input */
+
+/* IOT2040 MPIOs 8..15 */
+#define IOT2040_UARTS_ENABLE		0x03
+#define IOT2040_UARTS_GPIO_HI_MODE	0xF8	/* enable & LED as outputs */
+
+struct exar8250;
+
+struct exar8250_platform {
+	int (*rs485_config)(struct uart_port *port, struct ktermios *termios,
+			    struct serial_rs485 *rs485);
+	const struct serial_rs485 *rs485_supported;
+	int (*register_gpio)(struct pci_dev *, struct uart_8250_port *);
+	void (*unregister_gpio)(struct uart_8250_port *);
+};
+
+/**
+ * struct exar8250_board - board information
+ * @num_ports: number of serial ports
+ * @reg_shift: describes UART register mapping in PCI memory
+ * @setup: quirk run at ->probe() stage
+ * @exit: quirk run at ->remove() stage
+ */
+struct exar8250_board {
+	unsigned int num_ports;
+	unsigned int reg_shift;
+	int	(*setup)(struct exar8250 *, struct pci_dev *,
+			 struct uart_8250_port *, int);
+	void	(*exit)(struct pci_dev *pcidev);
+};
+
+struct exar8250 {
+	unsigned int		nr;
+	struct exar8250_board	*board;
+	void __iomem		*virt;
+	int			line[];
+};
+
+static void exar_pm(struct uart_port *port, unsigned int state, unsigned int old)
+{
+	/*
+	 * Exar UARTs have a SLEEP register that enables or disables each UART
+	 * to enter sleep mode separately. On the XR17V35x the register
+	 * is accessible to each UART at the UART_EXAR_SLEEP offset, but
+	 * the UART channel may only write to the corresponding bit.
+	 */
+	serial_port_out(port, UART_EXAR_SLEEP, state ? 0xff : 0);
+}
+
+/*
+ * XR17V35x UARTs have an extra fractional divisor register (DLD)
+ * Calculate divisor with extra 4-bit fractional portion
+ */
+static unsigned int xr17v35x_get_divisor(struct uart_port *p, unsigned int baud,
+					 unsigned int *frac)
+{
+	unsigned int quot_16;
+
+	quot_16 = DIV_ROUND_CLOSEST(p->uartclk, baud);
+	*frac = quot_16 & 0x0f;
+
+	return quot_16 >> 4;
+}
+
+static void xr17v35x_set_divisor(struct uart_port *p, unsigned int baud,
+				 unsigned int quot, unsigned int quot_frac)
+{
+	serial8250_do_set_divisor(p, baud, quot, quot_frac);
+
+	/* Preserve bits not related to baudrate; DLD[7:4]. */
+	quot_frac |= serial_port_in(p, 0x2) & 0xf0;
+	serial_port_out(p, 0x2, quot_frac);
+}
+
+static int xr17v35x_startup(struct uart_port *port)
+{
+	/*
+	 * First enable access to IER [7:5], ISR [5:4], FCR [5:4],
+	 * MCR [7:5] and MSR [7:0]
+	 */
+	serial_port_out(port, UART_XR_EFR, UART_EFR_ECB);
+
+	/*
+	 * Make sure all interrups are masked until initialization is
+	 * complete and the FIFOs are cleared
+	 *
+	 * Synchronize UART_IER access against the console.
+	 */
+	spin_lock_irq(&port->lock);
+	serial_port_out(port, UART_IER, 0);
+	spin_unlock_irq(&port->lock);
+
+	return serial8250_do_startup(port);
+}
+
+static void exar_shutdown(struct uart_port *port)
+{
+	bool tx_complete = false;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct circ_buf *xmit = &port->state->xmit;
+	int i = 0;
+	u16 lsr;
+
+	do {
+		lsr = serial_in(up, UART_LSR);
+		if (lsr & (UART_LSR_TEMT | UART_LSR_THRE))
+			tx_complete = true;
+		else
+			tx_complete = false;
+		usleep_range(1000, 1100);
+	} while (!uart_circ_empty(xmit) && !tx_complete && i++ < 1000);
+
+	serial8250_do_shutdown(port);
+}
+
+static int default_setup(struct exar8250 *priv, struct pci_dev *pcidev,
+			 int idx, unsigned int offset,
+			 struct uart_8250_port *port)
+{
+	const struct exar8250_board *board = priv->board;
+	unsigned int bar = 0;
+	unsigned char status;
+
+	port->port.iotype = UPIO_MEM;
+	port->port.mapbase = pci_resource_start(pcidev, bar) + offset;
+	port->port.membase = priv->virt + offset;
+	port->port.regshift = board->reg_shift;
+
+	/*
+	 * XR17V35x UARTs have an extra divisor register, DLD that gets enabled
+	 * with when DLAB is set which will cause the device to incorrectly match
+	 * and assign port type to PORT_16650. The EFR for this UART is found
+	 * at offset 0x09. Instead check the Deice ID (DVID) register
+	 * for a 2, 4 or 8 port UART.
+	 */
+	status = readb(port->port.membase + UART_EXAR_DVID);
+	if (status == 0x82 || status == 0x84 || status == 0x88) {
+		port->port.type = PORT_XR17V35X;
+
+		port->port.get_divisor = xr17v35x_get_divisor;
+		port->port.set_divisor = xr17v35x_set_divisor;
+
+		port->port.startup = xr17v35x_startup;
+	} else {
+		port->port.type = PORT_XR17D15X;
+	}
+
+	port->port.pm = exar_pm;
+	port->port.shutdown = exar_shutdown;
+
+	return 0;
+}
+
+static int
+pci_fastcom335_setup(struct exar8250 *priv, struct pci_dev *pcidev,
+		     struct uart_8250_port *port, int idx)
+{
+	unsigned int offset = idx * 0x200;
+	unsigned int baud = 1843200;
+	u8 __iomem *p;
+	int err;
+
+	port->port.uartclk = baud * 16;
+
+	err = default_setup(priv, pcidev, idx, offset, port);
+	if (err)
+		return err;
+
+	p = port->port.membase;
+
+	writeb(0x00, p + UART_EXAR_8XMODE);
+	writeb(UART_FCTR_EXAR_TRGD, p + UART_EXAR_FCTR);
+	writeb(32, p + UART_EXAR_TXTRG);
+	writeb(32, p + UART_EXAR_RXTRG);
+
+	/*
+	 * Setup Multipurpose Input/Output pins.
+	 */
+	if (idx == 0) {
+		switch (pcidev->device) {
+		case PCI_DEVICE_ID_COMMTECH_4222PCI335:
+		case PCI_DEVICE_ID_COMMTECH_4224PCI335:
+			writeb(0x78, p + UART_EXAR_MPIOLVL_7_0);
+			writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
+			writeb(0x00, p + UART_EXAR_MPIOSEL_7_0);
+			break;
+		case PCI_DEVICE_ID_COMMTECH_2324PCI335:
+		case PCI_DEVICE_ID_COMMTECH_2328PCI335:
+			writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
+			writeb(0xc0, p + UART_EXAR_MPIOINV_7_0);
+			writeb(0xc0, p + UART_EXAR_MPIOSEL_7_0);
+			break;
+		}
+		writeb(0x00, p + UART_EXAR_MPIOINT_7_0);
+		writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
+		writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
+	}
+
+	return 0;
+}
+
+static int
+pci_connect_tech_setup(struct exar8250 *priv, struct pci_dev *pcidev,
+		       struct uart_8250_port *port, int idx)
+{
+	unsigned int offset = idx * 0x200;
+	unsigned int baud = 1843200;
+
+	port->port.uartclk = baud * 16;
+	return default_setup(priv, pcidev, idx, offset, port);
+}
+
+static int
+pci_xr17c154_setup(struct exar8250 *priv, struct pci_dev *pcidev,
+		   struct uart_8250_port *port, int idx)
+{
+	unsigned int offset = idx * 0x200;
+	unsigned int baud = 921600;
+
+	port->port.uartclk = baud * 16;
+	return default_setup(priv, pcidev, idx, offset, port);
+}
+
+static void setup_gpio(struct pci_dev *pcidev, u8 __iomem *p)
+{
+	/*
+	 * The Commtech adapters required the MPIOs to be driven low. The Exar
+	 * devices will export them as GPIOs, so we pre-configure them safely
+	 * as inputs.
+	 */
+
+	u8 dir = 0x00;
+
+	if  ((pcidev->vendor == PCI_VENDOR_ID_EXAR) &&
+		(pcidev->subsystem_vendor != PCI_VENDOR_ID_SEALEVEL)) {
+		// Configure GPIO as inputs for Commtech adapters
+		dir = 0xff;
+	} else {
+		// Configure GPIO as outputs for SeaLevel adapters
+		dir = 0x00;
+	}
+
+	writeb(0x00, p + UART_EXAR_MPIOINT_7_0);
+	writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
+	writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
+	writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
+	writeb(dir,  p + UART_EXAR_MPIOSEL_7_0);
+	writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
+	writeb(0x00, p + UART_EXAR_MPIOINT_15_8);
+	writeb(0x00, p + UART_EXAR_MPIOLVL_15_8);
+	writeb(0x00, p + UART_EXAR_MPIO3T_15_8);
+	writeb(0x00, p + UART_EXAR_MPIOINV_15_8);
+	writeb(dir,  p + UART_EXAR_MPIOSEL_15_8);
+	writeb(0x00, p + UART_EXAR_MPIOOD_15_8);
+}
+
+static struct platform_device *__xr17v35x_register_gpio(struct pci_dev *pcidev,
+							const struct software_node *node)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_alloc("gpio_exar", PLATFORM_DEVID_AUTO);
+	if (!pdev)
+		return NULL;
+
+	pdev->dev.parent = &pcidev->dev;
+	ACPI_COMPANION_SET(&pdev->dev, ACPI_COMPANION(&pcidev->dev));
+
+	if (device_add_software_node(&pdev->dev, node) < 0 ||
+	    platform_device_add(pdev) < 0) {
+		platform_device_put(pdev);
+		return NULL;
+	}
+
+	return pdev;
+}
+
+static void __xr17v35x_unregister_gpio(struct platform_device *pdev)
+{
+	device_remove_software_node(&pdev->dev);
+	platform_device_unregister(pdev);
+}
+
+static const struct property_entry exar_gpio_properties[] = {
+	PROPERTY_ENTRY_U32("exar,first-pin", 0),
+	PROPERTY_ENTRY_U32("ngpios", 16),
+	{ }
+};
+
+static const struct software_node exar_gpio_node = {
+	.properties = exar_gpio_properties,
+};
+
+static int xr17v35x_register_gpio(struct pci_dev *pcidev, struct uart_8250_port *port)
+{
+	if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
+		port->port.private_data =
+			__xr17v35x_register_gpio(pcidev, &exar_gpio_node);
+
+	return 0;
+}
+
+static void xr17v35x_unregister_gpio(struct uart_8250_port *port)
+{
+	if (!port->port.private_data)
+		return;
+
+	__xr17v35x_unregister_gpio(port->port.private_data);
+	port->port.private_data = NULL;
+}
+
+static int generic_rs485_config(struct uart_port *port, struct ktermios *termios,
+				struct serial_rs485 *rs485)
+{
+	bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
+	u8 __iomem *p = port->membase;
+	u8 value;
+
+	value = readb(p + UART_EXAR_FCTR);
+	if (is_rs485)
+		value |= UART_FCTR_EXAR_485;
+	else
+		value &= ~UART_FCTR_EXAR_485;
+
+	writeb(value, p + UART_EXAR_FCTR);
+
+	if (is_rs485)
+		writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
+
+	return 0;
+}
+
+static const struct serial_rs485 generic_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
+};
+
+static const struct exar8250_platform exar8250_default_platform = {
+	.register_gpio = xr17v35x_register_gpio,
+	.unregister_gpio = xr17v35x_unregister_gpio,
+	.rs485_config = generic_rs485_config,
+	.rs485_supported = &generic_rs485_supported,
+};
+
+static int iot2040_rs485_config(struct uart_port *port, struct ktermios *termios,
+				struct serial_rs485 *rs485)
+{
+	bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
+	u8 __iomem *p = port->membase;
+	u8 mask = IOT2040_UART1_MASK;
+	u8 mode, value;
+
+	if (is_rs485) {
+		if (rs485->flags & SER_RS485_RX_DURING_TX)
+			mode = IOT2040_UART_MODE_RS422;
+		else
+			mode = IOT2040_UART_MODE_RS485;
+
+		if (rs485->flags & SER_RS485_TERMINATE_BUS)
+			mode |= IOT2040_UART_TERMINATE_BUS;
+	} else {
+		mode = IOT2040_UART_MODE_RS232;
+	}
+
+	if (port->line == 3) {
+		mask <<= IOT2040_UART2_SHIFT;
+		mode <<= IOT2040_UART2_SHIFT;
+	}
+
+	value = readb(p + UART_EXAR_MPIOLVL_7_0);
+	value &= ~mask;
+	value |= mode;
+	writeb(value, p + UART_EXAR_MPIOLVL_7_0);
+
+	return generic_rs485_config(port, termios, rs485);
+}
+
+static const struct serial_rs485 iot2040_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
+		 SER_RS485_RX_DURING_TX | SER_RS485_TERMINATE_BUS,
+};
+
+static const struct property_entry iot2040_gpio_properties[] = {
+	PROPERTY_ENTRY_U32("exar,first-pin", 10),
+	PROPERTY_ENTRY_U32("ngpios", 1),
+	{ }
+};
+
+static const struct software_node iot2040_gpio_node = {
+	.properties = iot2040_gpio_properties,
+};
+
+static int iot2040_register_gpio(struct pci_dev *pcidev,
+			      struct uart_8250_port *port)
+{
+	u8 __iomem *p = port->port.membase;
+
+	writeb(IOT2040_UARTS_DEFAULT_MODE, p + UART_EXAR_MPIOLVL_7_0);
+	writeb(IOT2040_UARTS_GPIO_LO_MODE, p + UART_EXAR_MPIOSEL_7_0);
+	writeb(IOT2040_UARTS_ENABLE, p + UART_EXAR_MPIOLVL_15_8);
+	writeb(IOT2040_UARTS_GPIO_HI_MODE, p + UART_EXAR_MPIOSEL_15_8);
+
+	port->port.private_data =
+		__xr17v35x_register_gpio(pcidev, &iot2040_gpio_node);
+
+	return 0;
+}
+
+static const struct exar8250_platform iot2040_platform = {
+	.rs485_config = iot2040_rs485_config,
+	.rs485_supported = &iot2040_rs485_supported,
+	.register_gpio = iot2040_register_gpio,
+	.unregister_gpio = xr17v35x_unregister_gpio,
+};
+
+/*
+ * For SIMATIC IOT2000, only IOT2040 and its variants have the Exar device,
+ * IOT2020 doesn't have. Therefore it is sufficient to match on the common
+ * board name after the device was found.
+ */
+static const struct dmi_system_id exar_platforms[] = {
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "SIMATIC IOT2000"),
+		},
+		.driver_data = (void *)&iot2040_platform,
+	},
+	{}
+};
+
+static const struct exar8250_platform *exar_get_platform(void)
+{
+	const struct dmi_system_id *dmi_match;
+
+	dmi_match = dmi_first_match(exar_platforms);
+	if (dmi_match)
+		return dmi_match->driver_data;
+
+	return &exar8250_default_platform;
+}
+
+static int
+pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
+		   struct uart_8250_port *port, int idx)
+{
+	const struct exar8250_platform *platform = exar_get_platform();
+	unsigned int offset = idx * 0x400;
+	unsigned int baud = 7812500;
+	u8 __iomem *p;
+	int ret;
+
+	port->port.uartclk = baud * 16;
+	port->port.rs485_config = platform->rs485_config;
+	port->port.rs485_supported = *(platform->rs485_supported);
+
+	/*
+	 * Setup the UART clock for the devices on expansion slot to
+	 * half the clock speed of the main chip (which is 125MHz)
+	 */
+	if (idx >= 8)
+		port->port.uartclk /= 2;
+
+	ret = default_setup(priv, pcidev, idx, offset, port);
+	if (ret)
+		return ret;
+
+	p = port->port.membase;
+
+	writeb(0x00, p + UART_EXAR_8XMODE);
+	writeb(UART_FCTR_EXAR_TRGD, p + UART_EXAR_FCTR);
+	writeb(128, p + UART_EXAR_TXTRG);
+	writeb(128, p + UART_EXAR_RXTRG);
+
+	if (idx == 0) {
+		/* Setup Multipurpose Input/Output pins. */
+		setup_gpio(pcidev, p);
+
+		ret = platform->register_gpio(pcidev, port);
+	}
+
+	return ret;
+}
+
+static void pci_xr17v35x_exit(struct pci_dev *pcidev)
+{
+	const struct exar8250_platform *platform = exar_get_platform();
+	struct exar8250 *priv = pci_get_drvdata(pcidev);
+	struct uart_8250_port *port = serial8250_get_port(priv->line[0]);
+
+	platform->unregister_gpio(port);
+}
+
+static inline void exar_misc_clear(struct exar8250 *priv)
+{
+	/* Clear all PCI interrupts by reading INT0. No effect on IIR */
+	readb(priv->virt + UART_EXAR_INT0);
+
+	/* Clear INT0 for Expansion Interface slave ports, too */
+	if (priv->board->num_ports > 8)
+		readb(priv->virt + 0x2000 + UART_EXAR_INT0);
+}
+
+/*
+ * These Exar UARTs have an extra interrupt indicator that could fire for a
+ * few interrupts that are not presented/cleared through IIR.  One of which is
+ * a wakeup interrupt when coming out of sleep.  These interrupts are only
+ * cleared by reading global INT0 or INT1 registers as interrupts are
+ * associated with channel 0. The INT[3:0] registers _are_ accessible from each
+ * channel's address space, but for the sake of bus efficiency we register a
+ * dedicated handler at the PCI device level to handle them.
+ */
+static irqreturn_t exar_misc_handler(int irq, void *data)
+{
+	exar_misc_clear(data);
+
+	return IRQ_HANDLED;
+}
+
+static int
+exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
+{
+	unsigned int nr_ports, i, bar = 0, maxnr;
+	struct exar8250_board *board;
+	struct uart_8250_port uart;
+	struct exar8250 *priv;
+	int rc;
+
+	board = (struct exar8250_board *)ent->driver_data;
+	if (!board)
+		return -EINVAL;
+
+	rc = pcim_enable_device(pcidev);
+	if (rc)
+		return rc;
+
+	maxnr = pci_resource_len(pcidev, bar) >> (board->reg_shift + 3);
+
+	if (pcidev->vendor == PCI_VENDOR_ID_ACCESSIO)
+		nr_ports = BIT(((pcidev->device & 0x38) >> 3) - 1);
+	else if (board->num_ports)
+		nr_ports = board->num_ports;
+	else if (pcidev->vendor == PCI_VENDOR_ID_SEALEVEL)
+		nr_ports = pcidev->device & 0xff;
+	else
+		nr_ports = pcidev->device & 0x0f;
+
+	priv = devm_kzalloc(&pcidev->dev, struct_size(priv, line, nr_ports), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->board = board;
+	priv->virt = pcim_iomap(pcidev, bar, 0);
+	if (!priv->virt)
+		return -ENOMEM;
+
+	pci_set_master(pcidev);
+
+	rc = pci_alloc_irq_vectors(pcidev, 1, 1, PCI_IRQ_ALL_TYPES);
+	if (rc < 0)
+		return rc;
+
+	memset(&uart, 0, sizeof(uart));
+	uart.port.flags = UPF_SHARE_IRQ | UPF_EXAR_EFR | UPF_FIXED_TYPE | UPF_FIXED_PORT;
+	uart.port.irq = pci_irq_vector(pcidev, 0);
+	uart.port.dev = &pcidev->dev;
+
+	rc = devm_request_irq(&pcidev->dev, uart.port.irq, exar_misc_handler,
+			 IRQF_SHARED, "exar_uart", priv);
+	if (rc)
+		return rc;
+
+	/* Clear interrupts */
+	exar_misc_clear(priv);
+
+	for (i = 0; i < nr_ports && i < maxnr; i++) {
+		rc = board->setup(priv, pcidev, &uart, i);
+		if (rc) {
+			dev_err(&pcidev->dev, "Failed to setup port %u\n", i);
+			break;
+		}
+
+		dev_dbg(&pcidev->dev, "Setup PCI port: port %lx, irq %d, type %d\n",
+			uart.port.iobase, uart.port.irq, uart.port.iotype);
+
+		priv->line[i] = serial8250_register_8250_port(&uart);
+		if (priv->line[i] < 0) {
+			dev_err(&pcidev->dev,
+				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
+				uart.port.iobase, uart.port.irq,
+				uart.port.iotype, priv->line[i]);
+			break;
+		}
+	}
+	priv->nr = i;
+	pci_set_drvdata(pcidev, priv);
+	return 0;
+}
+
+static void exar_pci_remove(struct pci_dev *pcidev)
+{
+	struct exar8250 *priv = pci_get_drvdata(pcidev);
+	unsigned int i;
+
+	for (i = 0; i < priv->nr; i++)
+		serial8250_unregister_port(priv->line[i]);
+
+	if (priv->board->exit)
+		priv->board->exit(pcidev);
+}
+
+static int __maybe_unused exar_suspend(struct device *dev)
+{
+	struct pci_dev *pcidev = to_pci_dev(dev);
+	struct exar8250 *priv = pci_get_drvdata(pcidev);
+	unsigned int i;
+
+	for (i = 0; i < priv->nr; i++)
+		if (priv->line[i] >= 0)
+			serial8250_suspend_port(priv->line[i]);
+
+	/* Ensure that every init quirk is properly torn down */
+	if (priv->board->exit)
+		priv->board->exit(pcidev);
+
+	return 0;
+}
+
+static int __maybe_unused exar_resume(struct device *dev)
+{
+	struct exar8250 *priv = dev_get_drvdata(dev);
+	unsigned int i;
+
+	exar_misc_clear(priv);
+
+	for (i = 0; i < priv->nr; i++)
+		if (priv->line[i] >= 0)
+			serial8250_resume_port(priv->line[i]);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(exar_pci_pm, exar_suspend, exar_resume);
+
+static const struct exar8250_board pbn_fastcom335_2 = {
+	.num_ports	= 2,
+	.setup		= pci_fastcom335_setup,
+};
+
+static const struct exar8250_board pbn_fastcom335_4 = {
+	.num_ports	= 4,
+	.setup		= pci_fastcom335_setup,
+};
+
+static const struct exar8250_board pbn_fastcom335_8 = {
+	.num_ports	= 8,
+	.setup		= pci_fastcom335_setup,
+};
+
+static const struct exar8250_board pbn_connect = {
+	.setup		= pci_connect_tech_setup,
+};
+
+static const struct exar8250_board pbn_exar_ibm_saturn = {
+	.num_ports	= 1,
+	.setup		= pci_xr17c154_setup,
+};
+
+static const struct exar8250_board pbn_exar_XR17C15x = {
+	.setup		= pci_xr17c154_setup,
+};
+
+static const struct exar8250_board pbn_exar_XR17V35x = {
+	.setup		= pci_xr17v35x_setup,
+	.exit		= pci_xr17v35x_exit,
+};
+
+static const struct exar8250_board pbn_fastcom35x_2 = {
+	.num_ports	= 2,
+	.setup		= pci_xr17v35x_setup,
+	.exit		= pci_xr17v35x_exit,
+};
+
+static const struct exar8250_board pbn_fastcom35x_4 = {
+	.num_ports	= 4,
+	.setup		= pci_xr17v35x_setup,
+	.exit		= pci_xr17v35x_exit,
+};
+
+static const struct exar8250_board pbn_fastcom35x_8 = {
+	.num_ports	= 8,
+	.setup		= pci_xr17v35x_setup,
+	.exit		= pci_xr17v35x_exit,
+};
+
+static const struct exar8250_board pbn_exar_XR17V4358 = {
+	.num_ports	= 12,
+	.setup		= pci_xr17v35x_setup,
+	.exit		= pci_xr17v35x_exit,
+};
+
+static const struct exar8250_board pbn_exar_XR17V8358 = {
+	.num_ports	= 16,
+	.setup		= pci_xr17v35x_setup,
+	.exit		= pci_xr17v35x_exit,
+};
+
+#define CONNECT_DEVICE(devid, sdevid, bd) {				\
+	PCI_DEVICE_SUB(							\
+		PCI_VENDOR_ID_EXAR,					\
+		PCI_DEVICE_ID_EXAR_##devid,				\
+		PCI_SUBVENDOR_ID_CONNECT_TECH,				\
+		PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_##sdevid), 0, 0,	\
+		(kernel_ulong_t)&bd					\
+	}
+
+#define EXAR_DEVICE(vend, devid, bd) { PCI_DEVICE_DATA(vend, devid, &bd) }
+
+#define IBM_DEVICE(devid, sdevid, bd) {			\
+	PCI_DEVICE_SUB(					\
+		PCI_VENDOR_ID_EXAR,			\
+		PCI_DEVICE_ID_EXAR_##devid,		\
+		PCI_VENDOR_ID_IBM,			\
+		PCI_SUBDEVICE_ID_IBM_##sdevid), 0, 0,	\
+		(kernel_ulong_t)&bd			\
+	}
+
+#define USR_DEVICE(devid, sdevid, bd) {			\
+	PCI_DEVICE_SUB(					\
+		PCI_VENDOR_ID_USR,			\
+		PCI_DEVICE_ID_EXAR_##devid,		\
+		PCI_VENDOR_ID_EXAR,			\
+		PCI_SUBDEVICE_ID_USR_##sdevid), 0, 0,	\
+		(kernel_ulong_t)&bd			\
+	}
+
+static const struct pci_device_id exar_pci_tbl[] = {
+	EXAR_DEVICE(ACCESSIO, COM_2S, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_4S, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_8S, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM232_8, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_2SM, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_4SM, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_8SM, pbn_exar_XR17C15x),
+
+	CONNECT_DEVICE(XR17C152, UART_2_232, pbn_connect),
+	CONNECT_DEVICE(XR17C154, UART_4_232, pbn_connect),
+	CONNECT_DEVICE(XR17C158, UART_8_232, pbn_connect),
+	CONNECT_DEVICE(XR17C152, UART_1_1, pbn_connect),
+	CONNECT_DEVICE(XR17C154, UART_2_2, pbn_connect),
+	CONNECT_DEVICE(XR17C158, UART_4_4, pbn_connect),
+	CONNECT_DEVICE(XR17C152, UART_2, pbn_connect),
+	CONNECT_DEVICE(XR17C154, UART_4, pbn_connect),
+	CONNECT_DEVICE(XR17C158, UART_8, pbn_connect),
+	CONNECT_DEVICE(XR17C152, UART_2_485, pbn_connect),
+	CONNECT_DEVICE(XR17C154, UART_4_485, pbn_connect),
+	CONNECT_DEVICE(XR17C158, UART_8_485, pbn_connect),
+
+	IBM_DEVICE(XR17C152, SATURN_SERIAL_ONE_PORT, pbn_exar_ibm_saturn),
+
+	/* USRobotics USR298x-OEM PCI Modems */
+	USR_DEVICE(XR17C152, 2980, pbn_exar_XR17C15x),
+	USR_DEVICE(XR17C152, 2981, pbn_exar_XR17C15x),
+
+	/* Exar Corp. XR17C15[248] Dual/Quad/Octal UART */
+	EXAR_DEVICE(EXAR, XR17C152, pbn_exar_XR17C15x),
+	EXAR_DEVICE(EXAR, XR17C154, pbn_exar_XR17C15x),
+	EXAR_DEVICE(EXAR, XR17C158, pbn_exar_XR17C15x),
+
+	/* Exar Corp. XR17V[48]35[248] Dual/Quad/Octal/Hexa PCIe UARTs */
+	EXAR_DEVICE(EXAR, XR17V352, pbn_exar_XR17V35x),
+	EXAR_DEVICE(EXAR, XR17V354, pbn_exar_XR17V35x),
+	EXAR_DEVICE(EXAR, XR17V358, pbn_exar_XR17V35x),
+	EXAR_DEVICE(EXAR, XR17V4358, pbn_exar_XR17V4358),
+	EXAR_DEVICE(EXAR, XR17V8358, pbn_exar_XR17V8358),
+	EXAR_DEVICE(COMMTECH, 4222PCIE, pbn_fastcom35x_2),
+	EXAR_DEVICE(COMMTECH, 4224PCIE, pbn_fastcom35x_4),
+	EXAR_DEVICE(COMMTECH, 4228PCIE, pbn_fastcom35x_8),
+
+	EXAR_DEVICE(COMMTECH, 4222PCI335, pbn_fastcom335_2),
+	EXAR_DEVICE(COMMTECH, 4224PCI335, pbn_fastcom335_4),
+	EXAR_DEVICE(COMMTECH, 2324PCI335, pbn_fastcom335_4),
+	EXAR_DEVICE(COMMTECH, 2328PCI335, pbn_fastcom335_8),
+
+	EXAR_DEVICE(SEALEVEL, 710xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 720xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 740xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 780xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 716xC, pbn_exar_XR17V35x),
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, exar_pci_tbl);
+
+static struct pci_driver exar_pci_driver = {
+	.name		= "exar_serial",
+	.probe		= exar_pci_probe,
+	.remove		= exar_pci_remove,
+	.driver         = {
+		.pm     = &exar_pci_pm,
+	},
+	.id_table	= exar_pci_tbl,
+};
+module_pci_driver(exar_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Exar Serial Driver");
+MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>");
diff --git a/drivers/tty/serial/8250/8250_exar_st16c554.c b/drivers/tty/serial/8250/8250_exar_st16c554.c
new file mode 100644
index 000000000..933811ebf
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_exar_st16c554.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Written by Paul B Schroeder < pschroeder "at" uplogix "dot" com >
+ *  Based on 8250_boca.
+ *
+ *  Copyright (C) 2005 Russell King.
+ *  Data taken from include/asm-i386/serial.h
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+static struct plat_serial8250_port exar_data[] = {
+	SERIAL8250_PORT(0x100, 5),
+	SERIAL8250_PORT(0x108, 5),
+	SERIAL8250_PORT(0x110, 5),
+	SERIAL8250_PORT(0x118, 5),
+	{ },
+};
+
+static struct platform_device exar_device = {
+	.name			= "serial8250",
+	.id			= PLAT8250_DEV_EXAR_ST16C554,
+	.dev			= {
+		.platform_data	= exar_data,
+	},
+};
+
+static int __init exar_init(void)
+{
+	return platform_device_register(&exar_device);
+}
+
+module_init(exar_init);
+
+MODULE_AUTHOR("Paul B Schroeder");
+MODULE_DESCRIPTION("8250 serial probe module for Exar cards");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
new file mode 100644
index 000000000..e2aa2a1a0
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Probe for F81216A LPC to 4 UART
+ *
+ *  Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pnp.h>
+#include <linux/kernel.h>
+#include <linux/serial_core.h>
+#include <linux/irq.h>
+#include  "8250.h"
+
+#define ADDR_PORT 0
+#define DATA_PORT 1
+#define EXIT_KEY 0xAA
+#define CHIP_ID1  0x20
+#define CHIP_ID2  0x21
+#define CHIP_ID_F81865 0x0407
+#define CHIP_ID_F81866 0x1010
+#define CHIP_ID_F81966 0x0215
+#define CHIP_ID_F81216AD 0x1602
+#define CHIP_ID_F81216H 0x0501
+#define CHIP_ID_F81216 0x0802
+#define VENDOR_ID1 0x23
+#define VENDOR_ID1_VAL 0x19
+#define VENDOR_ID2 0x24
+#define VENDOR_ID2_VAL 0x34
+#define IO_ADDR1 0x61
+#define IO_ADDR2 0x60
+#define LDN 0x7
+
+#define FINTEK_IRQ_MODE	0x70
+#define IRQ_SHARE	BIT(4)
+#define IRQ_MODE_MASK	(BIT(6) | BIT(5))
+#define IRQ_LEVEL_LOW	0
+#define IRQ_EDGE_HIGH	BIT(5)
+
+/*
+ * F81216H clock source register, the value and mask is the same with F81866,
+ * but it's on F0h.
+ *
+ * Clock speeds for UART (register F0h)
+ * 00: 1.8432MHz.
+ * 01: 18.432MHz.
+ * 10: 24MHz.
+ * 11: 14.769MHz.
+ */
+#define RS485  0xF0
+#define RTS_INVERT BIT(5)
+#define RS485_URA BIT(4)
+#define RXW4C_IRA BIT(3)
+#define TXW4C_IRA BIT(2)
+
+#define FIFO_CTRL		0xF6
+#define FIFO_MODE_MASK		(BIT(1) | BIT(0))
+#define FIFO_MODE_128		(BIT(1) | BIT(0))
+#define RXFTHR_MODE_MASK	(BIT(5) | BIT(4))
+#define RXFTHR_MODE_4X		BIT(5)
+
+#define F81216_LDN_LOW	0x0
+#define F81216_LDN_HIGH	0x4
+
+/*
+ * F81866/966 registers
+ *
+ * The IRQ setting mode of F81866/966 is not the same with F81216 series.
+ *	Level/Low: IRQ_MODE0:0, IRQ_MODE1:0
+ *	Edge/High: IRQ_MODE0:1, IRQ_MODE1:0
+ *
+ * Clock speeds for UART (register F2h)
+ * 00: 1.8432MHz.
+ * 01: 18.432MHz.
+ * 10: 24MHz.
+ * 11: 14.769MHz.
+ */
+#define F81866_IRQ_MODE		0xf0
+#define F81866_IRQ_SHARE	BIT(0)
+#define F81866_IRQ_MODE0	BIT(1)
+
+#define F81866_FIFO_CTRL	FIFO_CTRL
+#define F81866_IRQ_MODE1	BIT(3)
+
+#define F81866_LDN_LOW		0x10
+#define F81866_LDN_HIGH		0x16
+
+#define F81866_UART_CLK 0xF2
+#define F81866_UART_CLK_MASK (BIT(1) | BIT(0))
+#define F81866_UART_CLK_1_8432MHZ 0
+#define F81866_UART_CLK_14_769MHZ (BIT(1) | BIT(0))
+#define F81866_UART_CLK_18_432MHZ BIT(0)
+#define F81866_UART_CLK_24MHZ BIT(1)
+
+struct fintek_8250 {
+	u16 pid;
+	u16 base_port;
+	u8 index;
+	u8 key;
+};
+
+static u8 sio_read_reg(struct fintek_8250 *pdata, u8 reg)
+{
+	outb(reg, pdata->base_port + ADDR_PORT);
+	return inb(pdata->base_port + DATA_PORT);
+}
+
+static void sio_write_reg(struct fintek_8250 *pdata, u8 reg, u8 data)
+{
+	outb(reg, pdata->base_port + ADDR_PORT);
+	outb(data, pdata->base_port + DATA_PORT);
+}
+
+static void sio_write_mask_reg(struct fintek_8250 *pdata, u8 reg, u8 mask,
+			       u8 data)
+{
+	u8 tmp;
+
+	tmp = (sio_read_reg(pdata, reg) & ~mask) | (mask & data);
+	sio_write_reg(pdata, reg, tmp);
+}
+
+static int fintek_8250_enter_key(u16 base_port, u8 key)
+{
+	if (!request_muxed_region(base_port, 2, "8250_fintek"))
+		return -EBUSY;
+
+	/* Force to deactive all SuperIO in this base_port */
+	outb(EXIT_KEY, base_port + ADDR_PORT);
+
+	outb(key, base_port + ADDR_PORT);
+	outb(key, base_port + ADDR_PORT);
+	return 0;
+}
+
+static void fintek_8250_exit_key(u16 base_port)
+{
+
+	outb(EXIT_KEY, base_port + ADDR_PORT);
+	release_region(base_port + ADDR_PORT, 2);
+}
+
+static int fintek_8250_check_id(struct fintek_8250 *pdata)
+{
+	u16 chip;
+
+	if (sio_read_reg(pdata, VENDOR_ID1) != VENDOR_ID1_VAL)
+		return -ENODEV;
+
+	if (sio_read_reg(pdata, VENDOR_ID2) != VENDOR_ID2_VAL)
+		return -ENODEV;
+
+	chip = sio_read_reg(pdata, CHIP_ID1);
+	chip |= sio_read_reg(pdata, CHIP_ID2) << 8;
+
+	switch (chip) {
+	case CHIP_ID_F81865:
+	case CHIP_ID_F81866:
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81216AD:
+	case CHIP_ID_F81216H:
+	case CHIP_ID_F81216:
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	pdata->pid = chip;
+	return 0;
+}
+
+static int fintek_8250_get_ldn_range(struct fintek_8250 *pdata, int *min,
+				     int *max)
+{
+	switch (pdata->pid) {
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81865:
+	case CHIP_ID_F81866:
+		*min = F81866_LDN_LOW;
+		*max = F81866_LDN_HIGH;
+		return 0;
+
+	case CHIP_ID_F81216AD:
+	case CHIP_ID_F81216H:
+	case CHIP_ID_F81216:
+		*min = F81216_LDN_LOW;
+		*max = F81216_LDN_HIGH;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static int fintek_8250_rs485_config(struct uart_port *port, struct ktermios *termios,
+			      struct serial_rs485 *rs485)
+{
+	uint8_t config = 0;
+	struct fintek_8250 *pdata = port->private_data;
+
+	if (!pdata)
+		return -EINVAL;
+
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		/* Hardware do not support same RTS level on send and receive */
+		if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+		    !(rs485->flags & SER_RS485_RTS_AFTER_SEND))
+			return -EINVAL;
+		config |= RS485_URA;
+	}
+
+	if (rs485->delay_rts_before_send) {
+		rs485->delay_rts_before_send = 1;
+		config |= TXW4C_IRA;
+	}
+
+	if (rs485->delay_rts_after_send) {
+		rs485->delay_rts_after_send = 1;
+		config |= RXW4C_IRA;
+	}
+
+	if (rs485->flags & SER_RS485_RTS_ON_SEND)
+		config |= RTS_INVERT;
+
+	if (fintek_8250_enter_key(pdata->base_port, pdata->key))
+		return -EBUSY;
+
+	sio_write_reg(pdata, LDN, pdata->index);
+	sio_write_reg(pdata, RS485, config);
+	fintek_8250_exit_key(pdata->base_port);
+
+	return 0;
+}
+
+static void fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool is_level)
+{
+	sio_write_reg(pdata, LDN, pdata->index);
+
+	switch (pdata->pid) {
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81866:
+		sio_write_mask_reg(pdata, F81866_FIFO_CTRL, F81866_IRQ_MODE1,
+				   0);
+		fallthrough;
+	case CHIP_ID_F81865:
+		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_SHARE,
+				   F81866_IRQ_SHARE);
+		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_MODE0,
+				   is_level ? 0 : F81866_IRQ_MODE0);
+		break;
+
+	case CHIP_ID_F81216AD:
+	case CHIP_ID_F81216H:
+	case CHIP_ID_F81216:
+		sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_SHARE,
+				   IRQ_SHARE);
+		sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_MODE_MASK,
+				   is_level ? IRQ_LEVEL_LOW : IRQ_EDGE_HIGH);
+		break;
+	}
+}
+
+static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
+{
+	switch (pdata->pid) {
+	case CHIP_ID_F81216H: /* 128Bytes FIFO */
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81866:
+		sio_write_mask_reg(pdata, FIFO_CTRL,
+				   FIFO_MODE_MASK | RXFTHR_MODE_MASK,
+				   FIFO_MODE_128 | RXFTHR_MODE_4X);
+		break;
+
+	default: /* Default 16Bytes FIFO */
+		break;
+	}
+}
+
+static void fintek_8250_set_termios(struct uart_port *port,
+				    struct ktermios *termios,
+				    const struct ktermios *old)
+{
+	struct fintek_8250 *pdata = port->private_data;
+	unsigned int baud = tty_termios_baud_rate(termios);
+	int i;
+	u8 reg;
+	static u32 baudrate_table[] = {115200, 921600, 1152000, 1500000};
+	static u8 clock_table[] = { F81866_UART_CLK_1_8432MHZ,
+			F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,
+			F81866_UART_CLK_24MHZ };
+
+	/*
+	 * We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll
+	 * crash on baudrate_table[i] % baud with "division by zero".
+	 */
+	if (!baud)
+		goto exit;
+
+	switch (pdata->pid) {
+	case CHIP_ID_F81216H:
+		reg = RS485;
+		break;
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81866:
+		reg = F81866_UART_CLK;
+		break;
+	default:
+		/* Don't change clocksource with unknown PID */
+		dev_warn(port->dev,
+			"%s: pid: %x Not support. use default set_termios.\n",
+			__func__, pdata->pid);
+		goto exit;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
+		if (baud > baudrate_table[i] || baudrate_table[i] % baud != 0)
+			continue;
+
+		if (port->uartclk == baudrate_table[i] * 16)
+			break;
+
+		if (fintek_8250_enter_key(pdata->base_port, pdata->key))
+			continue;
+
+		port->uartclk = baudrate_table[i] * 16;
+
+		sio_write_reg(pdata, LDN, pdata->index);
+		sio_write_mask_reg(pdata, reg, F81866_UART_CLK_MASK,
+				clock_table[i]);
+
+		fintek_8250_exit_key(pdata->base_port);
+		break;
+	}
+
+	if (i == ARRAY_SIZE(baudrate_table)) {
+		baud = tty_termios_baud_rate(old);
+		tty_termios_encode_baud_rate(termios, baud, baud);
+	}
+
+exit:
+	serial8250_do_set_termios(port, termios, old);
+}
+
+static void fintek_8250_set_termios_handler(struct uart_8250_port *uart)
+{
+	struct fintek_8250 *pdata = uart->port.private_data;
+
+	switch (pdata->pid) {
+	case CHIP_ID_F81216H:
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81866:
+		uart->port.set_termios = fintek_8250_set_termios;
+		break;
+
+	default:
+		break;
+	}
+}
+
+static int probe_setup_port(struct fintek_8250 *pdata,
+					struct uart_8250_port *uart)
+{
+	static const u16 addr[] = {0x4e, 0x2e};
+	static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
+	struct irq_data *irq_data;
+	bool level_mode = false;
+	int i, j, k, min, max;
+
+	for (i = 0; i < ARRAY_SIZE(addr); i++) {
+		for (j = 0; j < ARRAY_SIZE(keys); j++) {
+			pdata->base_port = addr[i];
+			pdata->key = keys[j];
+
+			if (fintek_8250_enter_key(addr[i], keys[j]))
+				continue;
+			if (fintek_8250_check_id(pdata) ||
+			    fintek_8250_get_ldn_range(pdata, &min, &max)) {
+				fintek_8250_exit_key(addr[i]);
+				continue;
+			}
+
+			for (k = min; k < max; k++) {
+				u16 aux;
+
+				sio_write_reg(pdata, LDN, k);
+				aux = sio_read_reg(pdata, IO_ADDR1);
+				aux |= sio_read_reg(pdata, IO_ADDR2) << 8;
+				if (aux != uart->port.iobase)
+					continue;
+
+				pdata->index = k;
+
+				irq_data = irq_get_irq_data(uart->port.irq);
+				if (irq_data)
+					level_mode =
+						irqd_is_level_type(irq_data);
+
+				fintek_8250_set_irq_mode(pdata, level_mode);
+				fintek_8250_set_max_fifo(pdata);
+
+				fintek_8250_exit_key(addr[i]);
+
+				return 0;
+			}
+
+			fintek_8250_exit_key(addr[i]);
+		}
+	}
+
+	return -ENODEV;
+}
+
+/* Only the first port supports delays */
+static const struct serial_rs485 fintek_8250_rs485_supported_port0 = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+static const struct serial_rs485 fintek_8250_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
+};
+
+static void fintek_8250_set_rs485_handler(struct uart_8250_port *uart)
+{
+	struct fintek_8250 *pdata = uart->port.private_data;
+
+	switch (pdata->pid) {
+	case CHIP_ID_F81216AD:
+	case CHIP_ID_F81216H:
+	case CHIP_ID_F81966:
+	case CHIP_ID_F81866:
+	case CHIP_ID_F81865:
+		uart->port.rs485_config = fintek_8250_rs485_config;
+		if (!pdata->index)
+			uart->port.rs485_supported = fintek_8250_rs485_supported_port0;
+		else
+			uart->port.rs485_supported = fintek_8250_rs485_supported;
+		break;
+
+	default: /* No RS485 Auto direction functional */
+		break;
+	}
+}
+
+int fintek_8250_probe(struct uart_8250_port *uart)
+{
+	struct fintek_8250 *pdata;
+	struct fintek_8250 probe_data;
+
+	if (probe_setup_port(&probe_data, uart))
+		return -ENODEV;
+
+	pdata = devm_kzalloc(uart->port.dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	memcpy(pdata, &probe_data, sizeof(probe_data));
+	uart->port.private_data = pdata;
+	fintek_8250_set_rs485_handler(uart);
+	fintek_8250_set_termios_handler(uart);
+
+	return 0;
+}
diff --git a/drivers/tty/serial/8250/8250_fourport.c b/drivers/tty/serial/8250/8250_fourport.c
new file mode 100644
index 000000000..3215b9b7a
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_fourport.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2005 Russell King.
+ *  Data taken from include/asm-i386/serial.h
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+#define SERIAL8250_FOURPORT(_base, _irq) \
+	SERIAL8250_PORT_FLAGS(_base, _irq, UPF_FOURPORT)
+
+static struct plat_serial8250_port fourport_data[] = {
+	SERIAL8250_FOURPORT(0x1a0, 9),
+	SERIAL8250_FOURPORT(0x1a8, 9),
+	SERIAL8250_FOURPORT(0x1b0, 9),
+	SERIAL8250_FOURPORT(0x1b8, 9),
+	SERIAL8250_FOURPORT(0x2a0, 5),
+	SERIAL8250_FOURPORT(0x2a8, 5),
+	SERIAL8250_FOURPORT(0x2b0, 5),
+	SERIAL8250_FOURPORT(0x2b8, 5),
+	{ },
+};
+
+static struct platform_device fourport_device = {
+	.name			= "serial8250",
+	.id			= PLAT8250_DEV_FOURPORT,
+	.dev			= {
+		.platform_data	= fourport_data,
+	},
+};
+
+static int __init fourport_init(void)
+{
+	return platform_device_register(&fourport_device);
+}
+
+module_init(fourport_init);
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("8250 serial probe module for AST Fourport cards");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
new file mode 100644
index 000000000..6af4e1c12
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Freescale 16550 UART "driver", Copyright (C) 2011 Paul Gortmaker.
+ * Copyright 2020 NXP
+ * Copyright 2020 Puresoftware Ltd.
+ *
+ * This isn't a full driver; it just provides an alternate IRQ
+ * handler to deal with an errata and provide ACPI wrapper.
+ * Everything else is just using the bog standard 8250 support.
+ *
+ * We follow code flow of serial8250_default_handle_irq() but add
+ * a check for a break and insert a dummy read on the Rx for the
+ * immediately following IRQ event.
+ *
+ * We re-use the already existing "bug handling" lsr_saved_flags
+ * field to carry the "what we just did" information from the one
+ * IRQ event to the next one.
+ */
+
+#include <linux/acpi.h>
+#include <linux/serial_reg.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+int fsl8250_handle_irq(struct uart_port *port)
+{
+	unsigned long flags;
+	u16 lsr, orig_lsr;
+	unsigned int iir;
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	iir = port->serial_in(port, UART_IIR);
+	if (iir & UART_IIR_NO_INT) {
+		spin_unlock_irqrestore(&up->port.lock, flags);
+		return 0;
+	}
+
+	/*
+	 * For a single break the hardware reports LSR.BI for each character
+	 * time. This is described in the MPC8313E chip errata as "General17".
+	 * A typical break has a duration of 0.3s, with a 115200n8 configuration
+	 * that (theoretically) corresponds to ~3500 interrupts in these 0.3s.
+	 * In practise it's less (around 500) because of hardware
+	 * and software latencies. The workaround recommended by the vendor is
+	 * to read the RX register (to clear LSR.DR and thus prevent a FIFO
+	 * aging interrupt). To prevent the irq from retriggering LSR must not be
+	 * read. (This would clear LSR.BI, hardware would reassert the BI event
+	 * immediately and interrupt the CPU again. The hardware clears LSR.BI
+	 * when the next valid char is read.)
+	 */
+	if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
+		up->lsr_saved_flags &= ~UART_LSR_BI;
+		port->serial_in(port, UART_RX);
+		spin_unlock_irqrestore(&up->port.lock, flags);
+		return 1;
+	}
+
+	lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
+
+	/* Process incoming characters first */
+	if ((lsr & (UART_LSR_DR | UART_LSR_BI)) &&
+	    (up->ier & (UART_IER_RLSI | UART_IER_RDI))) {
+		lsr = serial8250_rx_chars(up, lsr);
+	}
+
+	/* Stop processing interrupts on input overrun */
+	if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
+		unsigned long delay;
+
+		up->ier = port->serial_in(port, UART_IER);
+		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
+			port->ops->stop_rx(port);
+		} else {
+			/* Keep restarting the timer until
+			 * the input overrun subsides.
+			 */
+			cancel_delayed_work(&up->overrun_backoff);
+		}
+
+		delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
+		schedule_delayed_work(&up->overrun_backoff, delay);
+	}
+
+	serial8250_modem_status(up);
+
+	if ((lsr & UART_LSR_THRE) && (up->ier & UART_IER_THRI))
+		serial8250_tx_chars(up);
+
+	up->lsr_saved_flags |= orig_lsr & UART_LSR_BI;
+
+	uart_unlock_and_check_sysrq_irqrestore(&up->port, flags);
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
+
+#ifdef CONFIG_ACPI
+struct fsl8250_data {
+	int	line;
+};
+
+static int fsl8250_acpi_probe(struct platform_device *pdev)
+{
+	struct fsl8250_data *data;
+	struct uart_8250_port port8250;
+	struct device *dev = &pdev->dev;
+	struct resource *regs;
+
+	int ret, irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(dev, "no registers defined\n");
+		return -EINVAL;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	memset(&port8250, 0, sizeof(port8250));
+
+	ret = device_property_read_u32(dev, "clock-frequency",
+					&port8250.port.uartclk);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&port8250.port.lock);
+
+	port8250.port.mapbase           = regs->start;
+	port8250.port.irq               = irq;
+	port8250.port.handle_irq        = fsl8250_handle_irq;
+	port8250.port.type              = PORT_16550A;
+	port8250.port.flags             = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
+						| UPF_FIXED_PORT | UPF_IOREMAP
+						| UPF_FIXED_TYPE;
+	port8250.port.dev               = dev;
+	port8250.port.mapsize           = resource_size(regs);
+	port8250.port.iotype            = UPIO_MEM;
+	port8250.port.irqflags          = IRQF_SHARED;
+
+	port8250.port.membase = devm_ioremap(dev,  port8250.port.mapbase,
+							port8250.port.mapsize);
+	if (!port8250.port.membase)
+		return -ENOMEM;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->line = serial8250_register_8250_port(&port8250);
+	if (data->line < 0)
+		return data->line;
+
+	platform_set_drvdata(pdev, data);
+	return 0;
+}
+
+static int fsl8250_acpi_remove(struct platform_device *pdev)
+{
+	struct fsl8250_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+	return 0;
+}
+
+static const struct acpi_device_id fsl_8250_acpi_id[] = {
+	{ "NXP0018", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, fsl_8250_acpi_id);
+
+static struct platform_driver fsl8250_platform_driver = {
+	.driver = {
+		.name			= "fsl-16550-uart",
+		.acpi_match_table	= ACPI_PTR(fsl_8250_acpi_id),
+	},
+	.probe			= fsl8250_acpi_probe,
+	.remove			= fsl8250_acpi_remove,
+};
+
+module_platform_driver(fsl8250_platform_driver);
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Handling of Freescale specific 8250 variants");
diff --git a/drivers/tty/serial/8250/8250_hp300.c b/drivers/tty/serial/8250/8250_hp300.c
new file mode 100644
index 000000000..3012ea03d
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_hp300.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the 98626/98644/internal serial interface on hp300/hp400
+ * (based on the National Semiconductor INS8250/NS16550AF/WD16C552 UARTs)
+ *
+ * Ported from 2.2 and modified to use the normal 8250 driver
+ * by Kars de Jong <jongk@linux-m68k.org>, May 2004.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/delay.h>
+#include <linux/dio.h>
+#include <linux/console.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+
+#include "8250.h"
+
+#if !defined(CONFIG_HPDCA) && !defined(CONFIG_HPAPCI) && !defined(CONFIG_COMPILE_TEST)
+#warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
+#endif
+
+#ifdef CONFIG_HPAPCI
+struct hp300_port {
+	struct hp300_port *next;	/* next port */
+	int line;			/* line (tty) number */
+};
+
+static struct hp300_port *hp300_ports;
+#endif
+
+#ifdef CONFIG_HPDCA
+
+static int hpdca_init_one(struct dio_dev *d,
+					const struct dio_device_id *ent);
+static void hpdca_remove_one(struct dio_dev *d);
+
+static struct dio_device_id hpdca_dio_tbl[] = {
+	{ DIO_ID_DCA0 },
+	{ DIO_ID_DCA0REM },
+	{ DIO_ID_DCA1 },
+	{ DIO_ID_DCA1REM },
+	{ 0 }
+};
+
+static struct dio_driver hpdca_driver = {
+	.name      = "hpdca",
+	.id_table  = hpdca_dio_tbl,
+	.probe     = hpdca_init_one,
+	.remove    = hpdca_remove_one,
+};
+
+#endif
+
+static unsigned int num_ports;
+
+extern int hp300_uart_scode;
+
+/* Offset to UART registers from base of DCA */
+#define UART_OFFSET	17
+
+#define DCA_ID		0x01	/* ID (read), reset (write) */
+#define DCA_IC		0x03	/* Interrupt control        */
+
+/* Interrupt control */
+#define DCA_IC_IE	0x80	/* Master interrupt enable  */
+
+#define HPDCA_BAUD_BASE 153600
+
+/* Base address of the Frodo part */
+#define FRODO_BASE	(0x41c000)
+
+/*
+ * Where we find the 8250-like APCI ports, and how far apart they are.
+ */
+#define FRODO_APCIBASE		0x0
+#define FRODO_APCISPACE		0x20
+#define FRODO_APCI_OFFSET(x)	(FRODO_APCIBASE + ((x) * FRODO_APCISPACE))
+
+#define HPAPCI_BAUD_BASE 500400
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+/*
+ * Parse the bootinfo to find descriptions for headless console and
+ * debug serial ports and register them with the 8250 driver.
+ */
+int __init hp300_setup_serial_console(void)
+{
+	int scode;
+	struct uart_port port;
+
+	memset(&port, 0, sizeof(port));
+
+	if (hp300_uart_scode < 0 || hp300_uart_scode > DIO_SCMAX)
+		return 0;
+
+	if (DIO_SCINHOLE(hp300_uart_scode))
+		return 0;
+
+	scode = hp300_uart_scode;
+
+	/* Memory mapped I/O */
+	port.iotype = UPIO_MEM;
+	port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
+	port.type = PORT_UNKNOWN;
+
+	/* Check for APCI console */
+	if (scode == 256) {
+#ifdef CONFIG_HPAPCI
+		pr_info("Serial console is HP APCI 1\n");
+
+		port.uartclk = HPAPCI_BAUD_BASE * 16;
+		port.mapbase = (FRODO_BASE + FRODO_APCI_OFFSET(1));
+		port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
+		port.regshift = 2;
+		add_preferred_console("ttyS", port.line, "9600n8");
+#else
+		pr_warn("Serial console is APCI but support is disabled (CONFIG_HPAPCI)!\n");
+		return 0;
+#endif
+	} else {
+#ifdef CONFIG_HPDCA
+		unsigned long pa = dio_scodetophysaddr(scode);
+		if (!pa)
+			return 0;
+
+		pr_info("Serial console is HP DCA at select code %d\n", scode);
+
+		port.uartclk = HPDCA_BAUD_BASE * 16;
+		port.mapbase = (pa + UART_OFFSET);
+		port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
+		port.regshift = 1;
+		port.irq = DIO_IPL(pa + DIO_VIRADDRBASE);
+
+		/* Enable board-interrupts */
+		out_8(pa + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
+
+		if (DIO_ID(pa + DIO_VIRADDRBASE) & 0x80)
+			add_preferred_console("ttyS", port.line, "9600n8");
+#else
+		pr_warn("Serial console is DCA but support is disabled (CONFIG_HPDCA)!\n");
+		return 0;
+#endif
+	}
+
+	if (early_serial_setup(&port) < 0)
+		pr_warn("%s: early_serial_setup() failed.\n", __func__);
+	return 0;
+}
+#endif /* CONFIG_SERIAL_8250_CONSOLE */
+
+#ifdef CONFIG_HPDCA
+static int hpdca_init_one(struct dio_dev *d,
+				const struct dio_device_id *ent)
+{
+	struct uart_8250_port uart;
+	int line;
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+	if (hp300_uart_scode == d->scode) {
+		/* Already got it. */
+		return 0;
+	}
+#endif
+	memset(&uart, 0, sizeof(uart));
+
+	/* Memory mapped I/O */
+	uart.port.iotype = UPIO_MEM;
+	uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
+	uart.port.irq = d->ipl;
+	uart.port.uartclk = HPDCA_BAUD_BASE * 16;
+	uart.port.mapbase = (d->resource.start + UART_OFFSET);
+	uart.port.membase = (char *)(uart.port.mapbase + DIO_VIRADDRBASE);
+	uart.port.regshift = 1;
+	uart.port.dev = &d->dev;
+	line = serial8250_register_8250_port(&uart);
+
+	if (line < 0) {
+		dev_notice(&d->dev,
+			  "8250_hp300: register_serial() DCA scode %d irq %d failed\n",
+			  d->scode, uart.port.irq);
+		return -ENOMEM;
+	}
+
+	/* Enable board-interrupts */
+	out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
+	dio_set_drvdata(d, (void *)line);
+
+	/* Reset the DCA */
+	out_8(d->resource.start + DIO_VIRADDRBASE + DCA_ID, 0xff);
+	udelay(100);
+
+	num_ports++;
+
+	return 0;
+}
+#endif
+
+static int __init hp300_8250_init(void)
+{
+	static int called;
+#ifdef CONFIG_HPAPCI
+	int line;
+	unsigned long base;
+	struct uart_8250_port uart;
+	struct hp300_port *port;
+	int i;
+#endif
+	if (called)
+		return -ENODEV;
+	called = 1;
+
+	if (!MACH_IS_HP300)
+		return -ENODEV;
+
+#ifdef CONFIG_HPDCA
+	dio_register_driver(&hpdca_driver);
+#endif
+#ifdef CONFIG_HPAPCI
+	if (hp300_model < HP_400) {
+		if (!num_ports)
+			return -ENODEV;
+		return 0;
+	}
+	/* These models have the Frodo chip.
+	 * Port 0 is reserved for the Apollo Domain keyboard.
+	 * Port 1 is either the console or the DCA.
+	 */
+	for (i = 1; i < 4; i++) {
+		/* Port 1 is the console on a 425e, on other machines it's
+		 * mapped to DCA.
+		 */
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+		if (i == 1)
+			continue;
+#endif
+
+		/* Create new serial device */
+		port = kmalloc(sizeof(struct hp300_port), GFP_KERNEL);
+		if (!port)
+			return -ENOMEM;
+
+		memset(&uart, 0, sizeof(uart));
+
+		base = (FRODO_BASE + FRODO_APCI_OFFSET(i));
+
+		/* Memory mapped I/O */
+		uart.port.iotype = UPIO_MEM;
+		uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ
+				| UPF_BOOT_AUTOCONF;
+		/* XXX - no interrupt support yet */
+		uart.port.irq = 0;
+		uart.port.uartclk = HPAPCI_BAUD_BASE * 16;
+		uart.port.mapbase = base;
+		uart.port.membase = (char *)(base + DIO_VIRADDRBASE);
+		uart.port.regshift = 2;
+
+		line = serial8250_register_8250_port(&uart);
+
+		if (line < 0) {
+			dev_notice(uart.port.dev,
+				   "8250_hp300: register_serial() APCI %d irq %d failed\n",
+				   i, uart.port.irq);
+			kfree(port);
+			continue;
+		}
+
+		port->line = line;
+		port->next = hp300_ports;
+		hp300_ports = port;
+
+		num_ports++;
+	}
+#endif
+
+	/* Any boards found? */
+	if (!num_ports)
+		return -ENODEV;
+
+	return 0;
+}
+
+#ifdef CONFIG_HPDCA
+static void hpdca_remove_one(struct dio_dev *d)
+{
+	int line;
+
+	line = (int) dio_get_drvdata(d);
+	if (d->resource.start) {
+		/* Disable board-interrupts */
+		out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, 0);
+	}
+	serial8250_unregister_port(line);
+}
+#endif
+
+static void __exit hp300_8250_exit(void)
+{
+#ifdef CONFIG_HPAPCI
+	struct hp300_port *port, *to_free;
+
+	for (port = hp300_ports; port; ) {
+		serial8250_unregister_port(port->line);
+		to_free = port;
+		port = port->next;
+		kfree(to_free);
+	}
+
+	hp300_ports = NULL;
+#endif
+#ifdef CONFIG_HPDCA
+	dio_unregister_driver(&hpdca_driver);
+#endif
+}
+
+module_init(hp300_8250_init);
+module_exit(hp300_8250_exit);
+MODULE_DESCRIPTION("HP DCA/APCI serial driver");
+MODULE_AUTHOR("Kars de Jong <jongk@linux-m68k.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_hub6.c b/drivers/tty/serial/8250/8250_hub6.c
new file mode 100644
index 000000000..273f59b9b
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_hub6.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2005 Russell King.
+ *  Data taken from include/asm-i386/serial.h
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+
+#define HUB6(card, port)						\
+	{								\
+		.iobase		= 0x302,				\
+		.irq		= 3,					\
+		.uartclk	= 1843200,				\
+		.iotype		= UPIO_HUB6,				\
+		.flags		= UPF_BOOT_AUTOCONF,			\
+		.hub6		= (card) << 6 | (port) << 3 | 1,	\
+	}
+
+static struct plat_serial8250_port hub6_data[] = {
+	HUB6(0, 0),
+	HUB6(0, 1),
+	HUB6(0, 2),
+	HUB6(0, 3),
+	HUB6(0, 4),
+	HUB6(0, 5),
+	HUB6(1, 0),
+	HUB6(1, 1),
+	HUB6(1, 2),
+	HUB6(1, 3),
+	HUB6(1, 4),
+	HUB6(1, 5),
+	{ },
+};
+
+static struct platform_device hub6_device = {
+	.name			= "serial8250",
+	.id			= PLAT8250_DEV_HUB6,
+	.dev			= {
+		.platform_data	= hub6_data,
+	},
+};
+
+static int __init hub6_init(void)
+{
+	return platform_device_register(&hub6_device);
+}
+
+module_init(hub6_init);
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("8250 serial probe module for Hub6 cards");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
new file mode 100644
index 000000000..4c4c4da73
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2010 Lars-Peter Clausen <lars@metafoo.de>
+ * Copyright (C) 2015 Imagination Technologies
+ *
+ * Ingenic SoC UART support
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/io.h>
+#include <linux/libfdt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/platform_device.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+
+#include "8250.h"
+
+/** ingenic_uart_config: SOC specific config data. */
+struct ingenic_uart_config {
+	int tx_loadsz;
+	int fifosize;
+};
+
+struct ingenic_uart_data {
+	struct clk	*clk_module;
+	struct clk	*clk_baud;
+	int		line;
+};
+
+static const struct of_device_id of_match[];
+
+#define UART_FCR_UME	BIT(4)
+
+#define UART_MCR_MDCE	BIT(7)
+#define UART_MCR_FCM	BIT(6)
+
+static struct earlycon_device *early_device;
+
+static uint8_t early_in(struct uart_port *port, int offset)
+{
+	return readl(port->membase + (offset << 2));
+}
+
+static void early_out(struct uart_port *port, int offset, uint8_t value)
+{
+	writel(value, port->membase + (offset << 2));
+}
+
+static void ingenic_early_console_putc(struct uart_port *port, unsigned char c)
+{
+	u16 lsr;
+
+	do {
+		lsr = early_in(port, UART_LSR);
+	} while ((lsr & UART_LSR_TEMT) == 0);
+
+	early_out(port, UART_TX, c);
+}
+
+static void ingenic_early_console_write(struct console *console,
+					      const char *s, unsigned int count)
+{
+	uart_console_write(&early_device->port, s, count,
+			   ingenic_early_console_putc);
+}
+
+static void __init ingenic_early_console_setup_clock(struct earlycon_device *dev)
+{
+	void *fdt = initial_boot_params;
+	const __be32 *prop;
+	int offset;
+
+	offset = fdt_path_offset(fdt, "/ext");
+	if (offset < 0)
+		return;
+
+	prop = fdt_getprop(fdt, offset, "clock-frequency", NULL);
+	if (!prop)
+		return;
+
+	dev->port.uartclk = be32_to_cpup(prop);
+}
+
+static int __init ingenic_earlycon_setup_tail(struct earlycon_device *dev,
+					      const char *opt)
+{
+	struct uart_port *port = &dev->port;
+	unsigned int divisor;
+	int baud = 115200;
+
+	if (!dev->port.membase)
+		return -ENODEV;
+
+	if (opt) {
+		unsigned int parity, bits, flow; /* unused for now */
+
+		uart_parse_options(opt, &baud, &parity, &bits, &flow);
+	}
+
+	if (dev->baud)
+		baud = dev->baud;
+	divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
+
+	early_out(port, UART_IER, 0);
+	early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);
+	early_out(port, UART_DLL, 0);
+	early_out(port, UART_DLM, 0);
+	early_out(port, UART_LCR, UART_LCR_WLEN8);
+	early_out(port, UART_FCR, UART_FCR_UME | UART_FCR_CLEAR_XMIT |
+			UART_FCR_CLEAR_RCVR | UART_FCR_ENABLE_FIFO);
+	early_out(port, UART_MCR, UART_MCR_RTS | UART_MCR_DTR);
+
+	early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);
+	early_out(port, UART_DLL, divisor & 0xff);
+	early_out(port, UART_DLM, (divisor >> 8) & 0xff);
+	early_out(port, UART_LCR, UART_LCR_WLEN8);
+
+	early_device = dev;
+	dev->con->write = ingenic_early_console_write;
+
+	return 0;
+}
+
+static int __init ingenic_early_console_setup(struct earlycon_device *dev,
+					      const char *opt)
+{
+	ingenic_early_console_setup_clock(dev);
+
+	return ingenic_earlycon_setup_tail(dev, opt);
+}
+
+static int __init jz4750_early_console_setup(struct earlycon_device *dev,
+					     const char *opt)
+{
+	/*
+	 * JZ4750/55/60 have an optional /2 divider between the EXT
+	 * oscillator and some peripherals including UART, which will
+	 * be enabled if using a 24 MHz oscillator, and disabled when
+	 * using a 12 MHz oscillator.
+	 */
+	ingenic_early_console_setup_clock(dev);
+	if (dev->port.uartclk >= 16000000)
+		dev->port.uartclk /= 2;
+
+	return ingenic_earlycon_setup_tail(dev, opt);
+}
+
+OF_EARLYCON_DECLARE(jz4740_uart, "ingenic,jz4740-uart",
+		    ingenic_early_console_setup);
+
+OF_EARLYCON_DECLARE(jz4750_uart, "ingenic,jz4750-uart",
+		    jz4750_early_console_setup);
+
+OF_EARLYCON_DECLARE(jz4770_uart, "ingenic,jz4770-uart",
+		    ingenic_early_console_setup);
+
+OF_EARLYCON_DECLARE(jz4775_uart, "ingenic,jz4775-uart",
+		    ingenic_early_console_setup);
+
+OF_EARLYCON_DECLARE(jz4780_uart, "ingenic,jz4780-uart",
+		    ingenic_early_console_setup);
+
+OF_EARLYCON_DECLARE(x1000_uart, "ingenic,x1000-uart",
+		    ingenic_early_console_setup);
+
+static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
+{
+	int ier;
+
+	switch (offset) {
+	case UART_FCR:
+		/* UART module enable */
+		value |= UART_FCR_UME;
+		break;
+
+	case UART_IER:
+		/*
+		 * Enable receive timeout interrupt with the receive line
+		 * status interrupt.
+		 */
+		value |= (value & 0x4) << 2;
+		break;
+
+	case UART_MCR:
+		/*
+		 * If we have enabled modem status IRQs we should enable
+		 * modem mode.
+		 */
+		ier = p->serial_in(p, UART_IER);
+
+		if (ier & UART_IER_MSI)
+			value |= UART_MCR_MDCE | UART_MCR_FCM;
+		else
+			value &= ~(UART_MCR_MDCE | UART_MCR_FCM);
+		break;
+
+	default:
+		break;
+	}
+
+	writeb(value, p->membase + (offset << p->regshift));
+}
+
+static unsigned int ingenic_uart_serial_in(struct uart_port *p, int offset)
+{
+	unsigned int value;
+
+	value = readb(p->membase + (offset << p->regshift));
+
+	/* Hide non-16550 compliant bits from higher levels */
+	switch (offset) {
+	case UART_FCR:
+		value &= ~UART_FCR_UME;
+		break;
+
+	case UART_MCR:
+		value &= ~(UART_MCR_MDCE | UART_MCR_FCM);
+		break;
+
+	default:
+		break;
+	}
+	return value;
+}
+
+static int ingenic_uart_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port uart = {};
+	struct ingenic_uart_data *data;
+	const struct ingenic_uart_config *cdata;
+	struct resource *regs;
+	int irq, err, line;
+
+	cdata = of_device_get_match_data(&pdev->dev);
+	if (!cdata) {
+		dev_err(&pdev->dev, "Error: No device match found\n");
+		return -ENODEV;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "no registers defined\n");
+		return -EINVAL;
+	}
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	spin_lock_init(&uart.port.lock);
+	uart.port.type = PORT_16550A;
+	uart.port.flags = UPF_SKIP_TEST | UPF_IOREMAP | UPF_FIXED_TYPE;
+	uart.port.iotype = UPIO_MEM;
+	uart.port.mapbase = regs->start;
+	uart.port.regshift = 2;
+	uart.port.serial_out = ingenic_uart_serial_out;
+	uart.port.serial_in = ingenic_uart_serial_in;
+	uart.port.irq = irq;
+	uart.port.dev = &pdev->dev;
+	uart.port.fifosize = cdata->fifosize;
+	uart.tx_loadsz = cdata->tx_loadsz;
+	uart.capabilities = UART_CAP_FIFO | UART_CAP_RTOIE;
+
+	/* Check for a fixed line number */
+	line = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (line >= 0)
+		uart.port.line = line;
+
+	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
+					 resource_size(regs));
+	if (!uart.port.membase)
+		return -ENOMEM;
+
+	data->clk_module = devm_clk_get(&pdev->dev, "module");
+	if (IS_ERR(data->clk_module))
+		return dev_err_probe(&pdev->dev, PTR_ERR(data->clk_module),
+				     "unable to get module clock\n");
+
+	data->clk_baud = devm_clk_get(&pdev->dev, "baud");
+	if (IS_ERR(data->clk_baud))
+		return dev_err_probe(&pdev->dev, PTR_ERR(data->clk_baud),
+				     "unable to get baud clock\n");
+
+	err = clk_prepare_enable(data->clk_module);
+	if (err) {
+		dev_err(&pdev->dev, "could not enable module clock: %d\n", err);
+		goto out;
+	}
+
+	err = clk_prepare_enable(data->clk_baud);
+	if (err) {
+		dev_err(&pdev->dev, "could not enable baud clock: %d\n", err);
+		goto out_disable_moduleclk;
+	}
+	uart.port.uartclk = clk_get_rate(data->clk_baud);
+
+	data->line = serial8250_register_8250_port(&uart);
+	if (data->line < 0) {
+		err = data->line;
+		goto out_disable_baudclk;
+	}
+
+	platform_set_drvdata(pdev, data);
+	return 0;
+
+out_disable_baudclk:
+	clk_disable_unprepare(data->clk_baud);
+out_disable_moduleclk:
+	clk_disable_unprepare(data->clk_module);
+out:
+	return err;
+}
+
+static int ingenic_uart_remove(struct platform_device *pdev)
+{
+	struct ingenic_uart_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+	clk_disable_unprepare(data->clk_module);
+	clk_disable_unprepare(data->clk_baud);
+	return 0;
+}
+
+static const struct ingenic_uart_config jz4740_uart_config = {
+	.tx_loadsz = 8,
+	.fifosize = 16,
+};
+
+static const struct ingenic_uart_config jz4760_uart_config = {
+	.tx_loadsz = 16,
+	.fifosize = 32,
+};
+
+static const struct ingenic_uart_config jz4780_uart_config = {
+	.tx_loadsz = 32,
+	.fifosize = 64,
+};
+
+static const struct ingenic_uart_config x1000_uart_config = {
+	.tx_loadsz = 32,
+	.fifosize = 64,
+};
+
+static const struct of_device_id of_match[] = {
+	{ .compatible = "ingenic,jz4740-uart", .data = &jz4740_uart_config },
+	{ .compatible = "ingenic,jz4750-uart", .data = &jz4760_uart_config },
+	{ .compatible = "ingenic,jz4760-uart", .data = &jz4760_uart_config },
+	{ .compatible = "ingenic,jz4770-uart", .data = &jz4760_uart_config },
+	{ .compatible = "ingenic,jz4775-uart", .data = &jz4760_uart_config },
+	{ .compatible = "ingenic,jz4780-uart", .data = &jz4780_uart_config },
+	{ .compatible = "ingenic,x1000-uart", .data = &x1000_uart_config },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, of_match);
+
+static struct platform_driver ingenic_uart_platform_driver = {
+	.driver = {
+		.name		= "ingenic-uart",
+		.of_match_table	= of_match,
+	},
+	.probe			= ingenic_uart_probe,
+	.remove			= ingenic_uart_remove,
+};
+
+module_platform_driver(ingenic_uart_platform_driver);
+
+MODULE_AUTHOR("Paul Burton");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Ingenic SoC UART driver");
diff --git a/drivers/tty/serial/8250/8250_ioc3.c b/drivers/tty/serial/8250/8250_ioc3.c
new file mode 100644
index 000000000..d5a39e105
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_ioc3.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SGI IOC3 8250 UART driver
+ *
+ * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de>
+ *
+ * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org>
+ *               Copyright (C) 2014 Joshua Kinard <kumba@gentoo.org>
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+
+#include "8250.h"
+
+#define IOC3_UARTCLK (22000000 / 3)
+
+struct ioc3_8250_data {
+	int line;
+};
+
+static unsigned int ioc3_serial_in(struct uart_port *p, int offset)
+{
+	return readb(p->membase + (offset ^ 3));
+}
+
+static void ioc3_serial_out(struct uart_port *p, int offset, int value)
+{
+	writeb(value, p->membase + (offset ^ 3));
+}
+
+static int serial8250_ioc3_probe(struct platform_device *pdev)
+{
+	struct ioc3_8250_data *data;
+	struct uart_8250_port up;
+	struct resource *r;
+	void __iomem *membase;
+	int irq, line;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -ENODEV;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	membase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
+	if (!membase)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		irq = 0; /* no interrupt -> use polling */
+
+	/* Register serial ports with 8250.c */
+	memset(&up, 0, sizeof(struct uart_8250_port));
+	up.port.iotype = UPIO_MEM;
+	up.port.uartclk = IOC3_UARTCLK;
+	up.port.type = PORT_16550A;
+	up.port.irq = irq;
+	up.port.flags = (UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ);
+	up.port.dev = &pdev->dev;
+	up.port.membase = membase;
+	up.port.mapbase = r->start;
+	up.port.serial_in = ioc3_serial_in;
+	up.port.serial_out = ioc3_serial_out;
+	line = serial8250_register_8250_port(&up);
+	if (line < 0)
+		return line;
+
+	platform_set_drvdata(pdev, data);
+	return 0;
+}
+
+static int serial8250_ioc3_remove(struct platform_device *pdev)
+{
+	struct ioc3_8250_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+	return 0;
+}
+
+static struct platform_driver serial8250_ioc3_driver = {
+	.probe  = serial8250_ioc3_probe,
+	.remove = serial8250_ioc3_remove,
+	.driver = {
+		.name = "ioc3-serial8250",
+	}
+};
+
+module_platform_driver(serial8250_ioc3_driver);
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");
+MODULE_DESCRIPTION("SGI IOC3 8250 UART driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_lpc18xx.c b/drivers/tty/serial/8250/8250_lpc18xx.c
new file mode 100644
index 000000000..6dc85aaba
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_lpc18xx.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Serial port driver for NXP LPC18xx/43xx UART
+ *
+ * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * Based on 8250_mtk.c:
+ * Copyright (c) 2014 MundoReader S.L.
+ * Matthias Brugger <matthias.bgg@gmail.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "8250.h"
+
+/* Additional LPC18xx/43xx 8250 registers and bits */
+#define LPC18XX_UART_RS485CTRL		(0x04c / sizeof(u32))
+#define  LPC18XX_UART_RS485CTRL_NMMEN	BIT(0)
+#define  LPC18XX_UART_RS485CTRL_DCTRL	BIT(4)
+#define  LPC18XX_UART_RS485CTRL_OINV	BIT(5)
+#define LPC18XX_UART_RS485DLY		(0x054 / sizeof(u32))
+#define LPC18XX_UART_RS485DLY_MAX	255
+
+struct lpc18xx_uart_data {
+	struct uart_8250_dma dma;
+	struct clk *clk_uart;
+	struct clk *clk_reg;
+	int line;
+};
+
+static int lpc18xx_rs485_config(struct uart_port *port, struct ktermios *termios,
+				struct serial_rs485 *rs485)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	u32 rs485_ctrl_reg = 0;
+	u32 rs485_dly_reg = 0;
+	unsigned baud_clk;
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		rs485_ctrl_reg |= LPC18XX_UART_RS485CTRL_NMMEN |
+				  LPC18XX_UART_RS485CTRL_DCTRL;
+
+		if (rs485->flags & SER_RS485_RTS_ON_SEND)
+			rs485_ctrl_reg |= LPC18XX_UART_RS485CTRL_OINV;
+	}
+
+	if (rs485->delay_rts_after_send) {
+		baud_clk = port->uartclk / up->dl_read(up);
+		rs485_dly_reg = DIV_ROUND_UP(rs485->delay_rts_after_send
+						* baud_clk, MSEC_PER_SEC);
+
+		if (rs485_dly_reg > LPC18XX_UART_RS485DLY_MAX)
+			rs485_dly_reg = LPC18XX_UART_RS485DLY_MAX;
+
+		/* Calculate the resulting delay in ms */
+		rs485->delay_rts_after_send = (rs485_dly_reg * MSEC_PER_SEC)
+						/ baud_clk;
+	}
+
+	serial_out(up, LPC18XX_UART_RS485CTRL, rs485_ctrl_reg);
+	serial_out(up, LPC18XX_UART_RS485DLY, rs485_dly_reg);
+
+	return 0;
+}
+
+static void lpc18xx_uart_serial_out(struct uart_port *p, int offset, int value)
+{
+	/*
+	 * For DMA mode one must ensure that the UART_FCR_DMA_SELECT
+	 * bit is set when FIFO is enabled. Even if DMA is not used
+	 * setting this bit doesn't seem to affect anything.
+	 */
+	if (offset == UART_FCR && (value & UART_FCR_ENABLE_FIFO))
+		value |= UART_FCR_DMA_SELECT;
+
+	offset = offset << p->regshift;
+	writel(value, p->membase + offset);
+}
+
+static const struct serial_rs485 lpc18xx_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
+	.delay_rts_after_send = 1,
+	/* Delay RTS before send is not supported */
+};
+
+static int lpc18xx_serial_probe(struct platform_device *pdev)
+{
+	struct lpc18xx_uart_data *data;
+	struct uart_8250_port uart;
+	struct resource *res;
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "memory resource not found");
+		return -EINVAL;
+	}
+
+	memset(&uart, 0, sizeof(uart));
+
+	uart.port.membase = devm_ioremap(&pdev->dev, res->start,
+					 resource_size(res));
+	if (!uart.port.membase)
+		return -ENOMEM;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk_uart = devm_clk_get(&pdev->dev, "uartclk");
+	if (IS_ERR(data->clk_uart)) {
+		dev_err(&pdev->dev, "uart clock not found\n");
+		return PTR_ERR(data->clk_uart);
+	}
+
+	data->clk_reg = devm_clk_get(&pdev->dev, "reg");
+	if (IS_ERR(data->clk_reg)) {
+		dev_err(&pdev->dev, "reg clock not found\n");
+		return PTR_ERR(data->clk_reg);
+	}
+
+	ret = clk_prepare_enable(data->clk_reg);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable reg clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(data->clk_uart);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable uart clock\n");
+		goto dis_clk_reg;
+	}
+
+	ret = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (ret >= 0)
+		uart.port.line = ret;
+
+	data->dma.rx_param = data;
+	data->dma.tx_param = data;
+
+	spin_lock_init(&uart.port.lock);
+	uart.port.dev = &pdev->dev;
+	uart.port.irq = irq;
+	uart.port.iotype = UPIO_MEM32;
+	uart.port.mapbase = res->start;
+	uart.port.regshift = 2;
+	uart.port.type = PORT_16550A;
+	uart.port.flags = UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_SKIP_TEST;
+	uart.port.uartclk = clk_get_rate(data->clk_uart);
+	uart.port.private_data = data;
+	uart.port.rs485_config = lpc18xx_rs485_config;
+	uart.port.rs485_supported = lpc18xx_rs485_supported;
+	uart.port.serial_out = lpc18xx_uart_serial_out;
+
+	uart.dma = &data->dma;
+	uart.dma->rxconf.src_maxburst = 1;
+	uart.dma->txconf.dst_maxburst = 1;
+
+	ret = serial8250_register_8250_port(&uart);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "unable to register 8250 port\n");
+		goto dis_uart_clk;
+	}
+
+	data->line = ret;
+	platform_set_drvdata(pdev, data);
+
+	return 0;
+
+dis_uart_clk:
+	clk_disable_unprepare(data->clk_uart);
+dis_clk_reg:
+	clk_disable_unprepare(data->clk_reg);
+	return ret;
+}
+
+static int lpc18xx_serial_remove(struct platform_device *pdev)
+{
+	struct lpc18xx_uart_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+	clk_disable_unprepare(data->clk_uart);
+	clk_disable_unprepare(data->clk_reg);
+
+	return 0;
+}
+
+static const struct of_device_id lpc18xx_serial_match[] = {
+	{ .compatible = "nxp,lpc1850-uart" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_serial_match);
+
+static struct platform_driver lpc18xx_serial_driver = {
+	.probe  = lpc18xx_serial_probe,
+	.remove = lpc18xx_serial_remove,
+	.driver = {
+		.name = "lpc18xx-uart",
+		.of_match_table = lpc18xx_serial_match,
+	},
+};
+module_platform_driver(lpc18xx_serial_driver);
+
+MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
+MODULE_DESCRIPTION("Serial port driver NXP LPC18xx/43xx devices");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
new file mode 100644
index 000000000..0e43bdfb7
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 8250_lpss.c - Driver for UART on Intel Braswell and various other Intel SoCs
+ *
+ * Copyright (C) 2016 Intel Corporation
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/rational.h>
+
+#include <linux/dmaengine.h>
+#include <linux/dma/dw.h>
+
+#include "8250_dwlib.h"
+
+#define PCI_DEVICE_ID_INTEL_QRK_UARTx	0x0936
+
+#define PCI_DEVICE_ID_INTEL_BYT_UART1	0x0f0a
+#define PCI_DEVICE_ID_INTEL_BYT_UART2	0x0f0c
+
+#define PCI_DEVICE_ID_INTEL_BSW_UART1	0x228a
+#define PCI_DEVICE_ID_INTEL_BSW_UART2	0x228c
+
+#define PCI_DEVICE_ID_INTEL_EHL_UART0	0x4b96
+#define PCI_DEVICE_ID_INTEL_EHL_UART1	0x4b97
+#define PCI_DEVICE_ID_INTEL_EHL_UART2	0x4b98
+#define PCI_DEVICE_ID_INTEL_EHL_UART3	0x4b99
+#define PCI_DEVICE_ID_INTEL_EHL_UART4	0x4b9a
+#define PCI_DEVICE_ID_INTEL_EHL_UART5	0x4b9b
+
+#define PCI_DEVICE_ID_INTEL_BDW_UART1	0x9ce3
+#define PCI_DEVICE_ID_INTEL_BDW_UART2	0x9ce4
+
+/* Intel LPSS specific registers */
+
+#define BYT_PRV_CLK			0x800
+#define BYT_PRV_CLK_EN			BIT(0)
+#define BYT_PRV_CLK_M_VAL_SHIFT		1
+#define BYT_PRV_CLK_N_VAL_SHIFT		16
+#define BYT_PRV_CLK_UPDATE		BIT(31)
+
+#define BYT_TX_OVF_INT			0x820
+#define BYT_TX_OVF_INT_MASK		BIT(1)
+
+struct lpss8250;
+
+struct lpss8250_board {
+	unsigned long freq;
+	unsigned int base_baud;
+	int (*setup)(struct lpss8250 *, struct uart_port *p);
+	void (*exit)(struct lpss8250 *);
+};
+
+struct lpss8250 {
+	struct dw8250_port_data data;
+	struct lpss8250_board *board;
+
+	/* DMA parameters */
+	struct dw_dma_chip dma_chip;
+	struct dw_dma_slave dma_param;
+	u8 dma_maxburst;
+};
+
+static inline struct lpss8250 *to_lpss8250(struct dw8250_port_data *data)
+{
+	return container_of(data, struct lpss8250, data);
+}
+
+static void byt_set_termios(struct uart_port *p, struct ktermios *termios,
+			    const struct ktermios *old)
+{
+	unsigned int baud = tty_termios_baud_rate(termios);
+	struct lpss8250 *lpss = to_lpss8250(p->private_data);
+	unsigned long fref = lpss->board->freq, fuart = baud * 16;
+	unsigned long w = BIT(15) - 1;
+	unsigned long m, n;
+	u32 reg;
+
+	/* Gracefully handle the B0 case: fall back to B9600 */
+	fuart = fuart ? fuart : 9600 * 16;
+
+	/* Get Fuart closer to Fref */
+	fuart *= rounddown_pow_of_two(fref / fuart);
+
+	/*
+	 * For baud rates 0.5M, 1M, 1.5M, 2M, 2.5M, 3M, 3.5M and 4M the
+	 * dividers must be adjusted.
+	 *
+	 * uartclk = (m / n) * 100 MHz, where m <= n
+	 */
+	rational_best_approximation(fuart, fref, w, w, &m, &n);
+	p->uartclk = fuart;
+
+	/* Reset the clock */
+	reg = (m << BYT_PRV_CLK_M_VAL_SHIFT) | (n << BYT_PRV_CLK_N_VAL_SHIFT);
+	writel(reg, p->membase + BYT_PRV_CLK);
+	reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
+	writel(reg, p->membase + BYT_PRV_CLK);
+
+	dw8250_do_set_termios(p, termios, old);
+}
+
+static unsigned int byt_get_mctrl(struct uart_port *port)
+{
+	unsigned int ret = serial8250_do_get_mctrl(port);
+
+	/* Force DCD and DSR signals to permanently be reported as active */
+	ret |= TIOCM_CAR | TIOCM_DSR;
+
+	return ret;
+}
+
+static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+	struct dw_dma_slave *param = &lpss->dma_param;
+	struct pci_dev *pdev = to_pci_dev(port->dev);
+	struct pci_dev *dma_dev;
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_INTEL_BYT_UART1:
+	case PCI_DEVICE_ID_INTEL_BSW_UART1:
+	case PCI_DEVICE_ID_INTEL_BDW_UART1:
+		param->src_id = 3;
+		param->dst_id = 2;
+		break;
+	case PCI_DEVICE_ID_INTEL_BYT_UART2:
+	case PCI_DEVICE_ID_INTEL_BSW_UART2:
+	case PCI_DEVICE_ID_INTEL_BDW_UART2:
+		param->src_id = 5;
+		param->dst_id = 4;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+
+	param->dma_dev = &dma_dev->dev;
+	param->m_master = 0;
+	param->p_master = 1;
+
+	lpss->dma_maxburst = 16;
+
+	port->set_termios = byt_set_termios;
+	port->get_mctrl = byt_get_mctrl;
+
+	/* Disable TX counter interrupts */
+	writel(BYT_TX_OVF_INT_MASK, port->membase + BYT_TX_OVF_INT);
+
+	return 0;
+}
+
+static void byt_serial_exit(struct lpss8250 *lpss)
+{
+	struct dw_dma_slave *param = &lpss->dma_param;
+
+	/* Paired with pci_get_slot() in the byt_serial_setup() above */
+	put_device(param->dma_dev);
+}
+
+static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+	struct uart_8250_dma *dma = &lpss->data.dma;
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/*
+	 * This simply makes the checks in the 8250_port to try the DMA
+	 * channel request which in turn uses the magic of ACPI tables
+	 * parsing (see drivers/dma/acpi-dma.c for the details) and
+	 * matching with the registered General Purpose DMA controllers.
+	 */
+	up->dma = dma;
+
+	lpss->dma_maxburst = 16;
+
+	port->set_termios = dw8250_do_set_termios;
+
+	return 0;
+}
+
+static void ehl_serial_exit(struct lpss8250 *lpss)
+{
+	struct uart_8250_port *up = serial8250_get_port(lpss->data.line);
+
+	up->dma = NULL;
+}
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
+	.nr_channels = 2,
+	.chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
+	.chan_priority = CHAN_PRIORITY_ASCENDING,
+	.block_size = 4095,
+	.nr_masters = 1,
+	.data_width = {4},
+	.multi_block = {0},
+};
+
+static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
+{
+	struct uart_8250_dma *dma = &lpss->data.dma;
+	struct dw_dma_chip *chip = &lpss->dma_chip;
+	struct dw_dma_slave *param = &lpss->dma_param;
+	struct pci_dev *pdev = to_pci_dev(port->dev);
+	int ret;
+
+	chip->pdata = &qrk_serial_dma_pdata;
+	chip->dev = &pdev->dev;
+	chip->id = pdev->devfn;
+	chip->irq = pci_irq_vector(pdev, 0);
+	chip->regs = pci_ioremap_bar(pdev, 1);
+	if (!chip->regs)
+		return;
+
+	/* Falling back to PIO mode if DMA probing fails */
+	ret = dw_dma_probe(chip);
+	if (ret)
+		return;
+
+	pci_try_set_mwi(pdev);
+
+	/* Special DMA address for UART */
+	dma->rx_dma_addr = 0xfffff000;
+	dma->tx_dma_addr = 0xfffff000;
+
+	param->dma_dev = &pdev->dev;
+	param->src_id = 0;
+	param->dst_id = 1;
+	param->hs_polarity = true;
+
+	lpss->dma_maxburst = 8;
+}
+
+static void qrk_serial_exit_dma(struct lpss8250 *lpss)
+{
+	struct dw_dma_chip *chip = &lpss->dma_chip;
+	struct dw_dma_slave *param = &lpss->dma_param;
+
+	if (!param->dma_dev)
+		return;
+
+	dw_dma_remove(chip);
+
+	pci_iounmap(to_pci_dev(chip->dev), chip->regs);
+}
+#else	/* CONFIG_SERIAL_8250_DMA */
+static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {}
+static void qrk_serial_exit_dma(struct lpss8250 *lpss) {}
+#endif	/* !CONFIG_SERIAL_8250_DMA */
+
+static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+	qrk_serial_setup_dma(lpss, port);
+	return 0;
+}
+
+static void qrk_serial_exit(struct lpss8250 *lpss)
+{
+	qrk_serial_exit_dma(lpss);
+}
+
+static bool lpss8250_dma_filter(struct dma_chan *chan, void *param)
+{
+	struct dw_dma_slave *dws = param;
+
+	if (dws->dma_dev != chan->device->dev)
+		return false;
+
+	chan->private = dws;
+	return true;
+}
+
+static int lpss8250_dma_setup(struct lpss8250 *lpss, struct uart_8250_port *port)
+{
+	struct uart_8250_dma *dma = &lpss->data.dma;
+	struct dw_dma_slave *rx_param, *tx_param;
+	struct device *dev = port->port.dev;
+
+	if (!lpss->dma_param.dma_dev) {
+		dma = port->dma;
+		if (dma)
+			goto out_configuration_only;
+
+		return 0;
+	}
+
+	rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
+	if (!rx_param)
+		return -ENOMEM;
+
+	tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
+	if (!tx_param)
+		return -ENOMEM;
+
+	*rx_param = lpss->dma_param;
+	*tx_param = lpss->dma_param;
+
+	dma->fn = lpss8250_dma_filter;
+	dma->rx_param = rx_param;
+	dma->tx_param = tx_param;
+
+	port->dma = dma;
+
+out_configuration_only:
+	dma->rxconf.src_maxburst = lpss->dma_maxburst;
+	dma->txconf.dst_maxburst = lpss->dma_maxburst;
+
+	return 0;
+}
+
+static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct uart_8250_port uart;
+	struct lpss8250 *lpss;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	pci_set_master(pdev);
+
+	lpss = devm_kzalloc(&pdev->dev, sizeof(*lpss), GFP_KERNEL);
+	if (!lpss)
+		return -ENOMEM;
+
+	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
+	if (ret < 0)
+		return ret;
+
+	lpss->board = (struct lpss8250_board *)id->driver_data;
+
+	memset(&uart, 0, sizeof(struct uart_8250_port));
+
+	uart.port.dev = &pdev->dev;
+	uart.port.irq = pci_irq_vector(pdev, 0);
+	uart.port.private_data = &lpss->data;
+	uart.port.type = PORT_16550A;
+	uart.port.iotype = UPIO_MEM32;
+	uart.port.regshift = 2;
+	uart.port.uartclk = lpss->board->base_baud * 16;
+	uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	uart.capabilities = UART_CAP_FIFO | UART_CAP_AFE;
+	uart.port.mapbase = pci_resource_start(pdev, 0);
+	uart.port.membase = pcim_iomap(pdev, 0, 0);
+	if (!uart.port.membase)
+		return -ENOMEM;
+
+	ret = lpss->board->setup(lpss, &uart.port);
+	if (ret)
+		return ret;
+
+	dw8250_setup_port(&uart.port);
+
+	ret = lpss8250_dma_setup(lpss, &uart);
+	if (ret)
+		goto err_exit;
+
+	ret = serial8250_register_8250_port(&uart);
+	if (ret < 0)
+		goto err_exit;
+
+	lpss->data.line = ret;
+
+	pci_set_drvdata(pdev, lpss);
+	return 0;
+
+err_exit:
+	lpss->board->exit(lpss);
+	pci_free_irq_vectors(pdev);
+	return ret;
+}
+
+static void lpss8250_remove(struct pci_dev *pdev)
+{
+	struct lpss8250 *lpss = pci_get_drvdata(pdev);
+
+	serial8250_unregister_port(lpss->data.line);
+
+	lpss->board->exit(lpss);
+	pci_free_irq_vectors(pdev);
+}
+
+static const struct lpss8250_board byt_board = {
+	.freq = 100000000,
+	.base_baud = 2764800,
+	.setup = byt_serial_setup,
+	.exit = byt_serial_exit,
+};
+
+static const struct lpss8250_board ehl_board = {
+	.freq = 200000000,
+	.base_baud = 12500000,
+	.setup = ehl_serial_setup,
+	.exit = ehl_serial_exit,
+};
+
+static const struct lpss8250_board qrk_board = {
+	.freq = 44236800,
+	.base_baud = 2764800,
+	.setup = qrk_serial_setup,
+	.exit = qrk_serial_exit,
+};
+
+static const struct pci_device_id pci_ids[] = {
+	{ PCI_DEVICE_DATA(INTEL, QRK_UARTx, &qrk_board) },
+	{ PCI_DEVICE_DATA(INTEL, EHL_UART0, &ehl_board) },
+	{ PCI_DEVICE_DATA(INTEL, EHL_UART1, &ehl_board) },
+	{ PCI_DEVICE_DATA(INTEL, EHL_UART2, &ehl_board) },
+	{ PCI_DEVICE_DATA(INTEL, EHL_UART3, &ehl_board) },
+	{ PCI_DEVICE_DATA(INTEL, EHL_UART4, &ehl_board) },
+	{ PCI_DEVICE_DATA(INTEL, EHL_UART5, &ehl_board) },
+	{ PCI_DEVICE_DATA(INTEL, BYT_UART1, &byt_board) },
+	{ PCI_DEVICE_DATA(INTEL, BYT_UART2, &byt_board) },
+	{ PCI_DEVICE_DATA(INTEL, BSW_UART1, &byt_board) },
+	{ PCI_DEVICE_DATA(INTEL, BSW_UART2, &byt_board) },
+	{ PCI_DEVICE_DATA(INTEL, BDW_UART1, &byt_board) },
+	{ PCI_DEVICE_DATA(INTEL, BDW_UART2, &byt_board) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+static struct pci_driver lpss8250_pci_driver = {
+	.name           = "8250_lpss",
+	.id_table       = pci_ids,
+	.probe          = lpss8250_probe,
+	.remove         = lpss8250_remove,
+};
+
+module_pci_driver(lpss8250_pci_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel LPSS UART driver");
diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
new file mode 100644
index 000000000..dc9e093b1
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/mcb.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_8250.h>
+
+#define MEN_UART_ID_Z025 0x19
+#define MEN_UART_ID_Z057 0x39
+#define MEN_UART_ID_Z125 0x7d
+
+/*
+ * IP Cores Z025 and Z057 can have up to 4 UART
+ * The UARTs available are stored in a global
+ * register saved in physical address + 0x40
+ * Is saved as follows:
+ *
+ * 7                                                              0
+ * +------+-------+-------+-------+-------+-------+-------+-------+
+ * |UART4 | UART3 | UART2 | UART1 | U4irq | U3irq | U2irq | U1irq |
+ * +------+-------+-------+-------+-------+-------+-------+-------+
+ */
+#define MEN_UART1_MASK	0x01
+#define MEN_UART2_MASK	0x02
+#define MEN_UART3_MASK	0x04
+#define MEN_UART4_MASK	0x08
+
+#define MEN_Z125_UARTS_AVAILABLE	0x01
+
+#define MEN_Z025_MAX_UARTS		4
+#define MEN_UART_MEM_SIZE		0x10
+#define MEM_UART_REGISTER_SIZE		0x01
+#define MEN_Z025_REGISTER_OFFSET	0x40
+
+#define MEN_UART1_OFFSET	0
+#define MEN_UART2_OFFSET	(MEN_UART1_OFFSET + MEN_UART_MEM_SIZE)
+#define MEN_UART3_OFFSET	(MEN_UART2_OFFSET + MEN_UART_MEM_SIZE)
+#define MEN_UART4_OFFSET	(MEN_UART3_OFFSET + MEN_UART_MEM_SIZE)
+
+#define MEN_READ_REGISTER(addr)	readb(addr)
+
+#define MAX_PORTS	4
+
+struct serial_8250_men_mcb_data {
+	int num_ports;
+	int line[MAX_PORTS];
+	unsigned int offset[MAX_PORTS];
+};
+
+/*
+ * The Z125 16550-compatible UART has no fixed base clock assigned
+ * So, depending on the board we're on, we need to adjust the
+ * parameter in order to really set the correct baudrate, and
+ * do so if possible without user interaction
+ */
+static u32 men_lookup_uartclk(struct mcb_device *mdev)
+{
+	/* use default value if board is not available below */
+	u32 clkval = 1041666;
+
+	dev_info(&mdev->dev, "%s on board %s\n",
+		dev_name(&mdev->dev),
+		mdev->bus->name);
+	if  (strncmp(mdev->bus->name, "F075", 4) == 0)
+		clkval = 1041666;
+	else if (strncmp(mdev->bus->name, "F216", 4) == 0)
+		clkval = 1843200;
+	else if (strncmp(mdev->bus->name, "F210", 4) == 0)
+		clkval = 115200;
+	else if (strstr(mdev->bus->name, "215"))
+		clkval = 1843200;
+	else
+		dev_info(&mdev->dev,
+			 "board not detected, using default uartclk\n");
+
+	clkval = clkval  << 4;
+
+	return clkval;
+}
+
+static int read_uarts_available_from_register(struct resource *mem_res,
+					      u8 *uarts_available)
+{
+	void __iomem *mem;
+	int reg_value;
+
+	if (!request_mem_region(mem_res->start + MEN_Z025_REGISTER_OFFSET,
+				MEM_UART_REGISTER_SIZE,  KBUILD_MODNAME)) {
+		return -EBUSY;
+	}
+
+	mem = ioremap(mem_res->start + MEN_Z025_REGISTER_OFFSET,
+		      MEM_UART_REGISTER_SIZE);
+	if (!mem) {
+		release_mem_region(mem_res->start + MEN_Z025_REGISTER_OFFSET,
+				   MEM_UART_REGISTER_SIZE);
+		return -ENOMEM;
+	}
+
+	reg_value = MEN_READ_REGISTER(mem);
+
+	iounmap(mem);
+
+	release_mem_region(mem_res->start + MEN_Z025_REGISTER_OFFSET,
+			   MEM_UART_REGISTER_SIZE);
+
+	*uarts_available = reg_value >> 4;
+
+	return 0;
+}
+
+static int read_serial_data(struct mcb_device *mdev,
+			    struct resource *mem_res,
+			    struct serial_8250_men_mcb_data *serial_data)
+{
+	u8 uarts_available;
+	int count = 0;
+	int mask;
+	int res;
+	int i;
+
+	res = read_uarts_available_from_register(mem_res, &uarts_available);
+	if (res < 0)
+		return res;
+
+	for (i = 0; i < MAX_PORTS; i++) {
+		mask = 0x1 << i;
+		switch (uarts_available & mask) {
+		case MEN_UART1_MASK:
+			serial_data->offset[count] = MEN_UART1_OFFSET;
+			count++;
+			break;
+		case MEN_UART2_MASK:
+			serial_data->offset[count] = MEN_UART2_OFFSET;
+			count++;
+			break;
+		case MEN_UART3_MASK:
+			serial_data->offset[count] = MEN_UART3_OFFSET;
+			count++;
+			break;
+		case MEN_UART4_MASK:
+			serial_data->offset[count] = MEN_UART4_OFFSET;
+			count++;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (count <= 0 || count > MAX_PORTS) {
+		dev_err(&mdev->dev, "unexpected number of ports: %u\n",
+			count);
+		return -ENODEV;
+	}
+
+	serial_data->num_ports = count;
+
+	return 0;
+}
+
+static int init_serial_data(struct mcb_device *mdev,
+			    struct resource *mem_res,
+			    struct serial_8250_men_mcb_data *serial_data)
+{
+	switch (mdev->id) {
+	case MEN_UART_ID_Z125:
+		serial_data->num_ports = 1;
+		serial_data->offset[0] = 0;
+		return 0;
+	case MEN_UART_ID_Z025:
+	case MEN_UART_ID_Z057:
+		return read_serial_data(mdev, mem_res, serial_data);
+	default:
+		dev_err(&mdev->dev, "no supported device!\n");
+		return -ENODEV;
+	}
+}
+
+static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
+				     const struct mcb_device_id *id)
+{
+	struct uart_8250_port uart;
+	struct serial_8250_men_mcb_data *data;
+	struct resource *mem;
+	int i;
+	int res;
+
+	mem = mcb_get_resource(mdev, IORESOURCE_MEM);
+	if (mem == NULL)
+		return -ENXIO;
+
+	data = devm_kzalloc(&mdev->dev,
+			    sizeof(struct serial_8250_men_mcb_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = init_serial_data(mdev, mem, data);
+	if (res < 0)
+		return res;
+
+	dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n",
+		mdev->id, data->num_ports);
+
+	mcb_set_drvdata(mdev, data);
+
+	for (i = 0; i < data->num_ports; i++) {
+		memset(&uart, 0, sizeof(struct uart_8250_port));
+		spin_lock_init(&uart.port.lock);
+
+		uart.port.flags = UPF_SKIP_TEST |
+				  UPF_SHARE_IRQ |
+				  UPF_BOOT_AUTOCONF |
+				  UPF_IOREMAP;
+		uart.port.iotype = UPIO_MEM;
+		uart.port.uartclk = men_lookup_uartclk(mdev);
+		uart.port.irq = mcb_get_irq(mdev);
+		uart.port.mapbase = (unsigned long) mem->start
+					    + data->offset[i];
+
+		/* ok, register the port */
+		res = serial8250_register_8250_port(&uart);
+		if (res < 0) {
+			dev_err(&mdev->dev, "unable to register UART port\n");
+			return res;
+		}
+
+		data->line[i] = res;
+		dev_info(&mdev->dev, "found MCB UART: ttyS%d\n", data->line[i]);
+	}
+
+	return 0;
+}
+
+static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
+{
+	int i;
+	struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
+
+	if (!data)
+		return;
+
+	for (i = 0; i < data->num_ports; i++)
+		serial8250_unregister_port(data->line[i]);
+}
+
+static const struct mcb_device_id serial_8250_men_mcb_ids[] = {
+	{ .device = MEN_UART_ID_Z025 },
+	{ .device = MEN_UART_ID_Z057 },
+	{ .device = MEN_UART_ID_Z125 },
+	{ }
+};
+MODULE_DEVICE_TABLE(mcb, serial_8250_men_mcb_ids);
+
+static struct mcb_driver mcb_driver = {
+	.driver = {
+		.name = "8250_men_mcb",
+	},
+	.probe = serial_8250_men_mcb_probe,
+	.remove = serial_8250_men_mcb_remove,
+	.id_table = serial_8250_men_mcb_ids,
+};
+module_mcb_driver(mcb_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MEN 8250 UART driver");
+MODULE_AUTHOR("Michael Moese <michael.moese@men.de");
+MODULE_ALIAS("mcb:16z125");
+MODULE_ALIAS("mcb:16z025");
+MODULE_ALIAS("mcb:16z057");
+MODULE_IMPORT_NS(MCB);
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
new file mode 100644
index 000000000..2cc78a4bf
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
+ *
+ * Copyright (C) 2015 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/rational.h>
+
+#include <linux/dma/hsu.h>
+#include <linux/8250_pci.h>
+
+#include "8250.h"
+
+#define PCI_DEVICE_ID_INTEL_PNW_UART1	0x081b
+#define PCI_DEVICE_ID_INTEL_PNW_UART2	0x081c
+#define PCI_DEVICE_ID_INTEL_PNW_UART3	0x081d
+#define PCI_DEVICE_ID_INTEL_TNG_UART	0x1191
+#define PCI_DEVICE_ID_INTEL_CDF_UART	0x18d8
+#define PCI_DEVICE_ID_INTEL_DNV_UART	0x19d8
+
+/* Intel MID Specific registers */
+#define INTEL_MID_UART_FISR		0x08
+#define INTEL_MID_UART_PS		0x30
+#define INTEL_MID_UART_MUL		0x34
+#define INTEL_MID_UART_DIV		0x38
+
+struct mid8250;
+
+struct mid8250_board {
+	unsigned int flags;
+	unsigned long freq;
+	unsigned int base_baud;
+	int (*setup)(struct mid8250 *, struct uart_port *p);
+	void (*exit)(struct mid8250 *);
+};
+
+struct mid8250 {
+	int line;
+	int dma_index;
+	struct pci_dev *dma_dev;
+	struct uart_8250_dma dma;
+	struct mid8250_board *board;
+	struct hsu_dma_chip dma_chip;
+};
+
+/*****************************************************************************/
+
+static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
+{
+	struct pci_dev *pdev = to_pci_dev(p->dev);
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_INTEL_PNW_UART1:
+		mid->dma_index = 0;
+		break;
+	case PCI_DEVICE_ID_INTEL_PNW_UART2:
+		mid->dma_index = 1;
+		break;
+	case PCI_DEVICE_ID_INTEL_PNW_UART3:
+		mid->dma_index = 2;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mid->dma_dev = pci_get_slot(pdev->bus,
+				    PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
+	return 0;
+}
+
+static void pnw_exit(struct mid8250 *mid)
+{
+	pci_dev_put(mid->dma_dev);
+}
+
+static int tng_handle_irq(struct uart_port *p)
+{
+	struct mid8250 *mid = p->private_data;
+	struct uart_8250_port *up = up_to_u8250p(p);
+	struct hsu_dma_chip *chip;
+	u32 status;
+	int ret = 0;
+	int err;
+
+	chip = pci_get_drvdata(mid->dma_dev);
+
+	/* Rx DMA */
+	err = hsu_dma_get_status(chip, mid->dma_index * 2 + 1, &status);
+	if (err > 0) {
+		serial8250_rx_dma_flush(up);
+		ret |= 1;
+	} else if (err == 0)
+		ret |= hsu_dma_do_irq(chip, mid->dma_index * 2 + 1, status);
+
+	/* Tx DMA */
+	err = hsu_dma_get_status(chip, mid->dma_index * 2, &status);
+	if (err > 0)
+		ret |= 1;
+	else if (err == 0)
+		ret |= hsu_dma_do_irq(chip, mid->dma_index * 2, status);
+
+	/* UART */
+	ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
+	return IRQ_RETVAL(ret);
+}
+
+static int tng_setup(struct mid8250 *mid, struct uart_port *p)
+{
+	struct pci_dev *pdev = to_pci_dev(p->dev);
+	int index = PCI_FUNC(pdev->devfn);
+
+	/*
+	 * Device 0000:00:04.0 is not a real HSU port. It provides a global
+	 * register set for all HSU ports, although it has the same PCI ID.
+	 * Skip it here.
+	 */
+	if (index-- == 0)
+		return -ENODEV;
+
+	mid->dma_index = index;
+	mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
+
+	p->handle_irq = tng_handle_irq;
+	return 0;
+}
+
+static void tng_exit(struct mid8250 *mid)
+{
+	pci_dev_put(mid->dma_dev);
+}
+
+static int dnv_handle_irq(struct uart_port *p)
+{
+	struct mid8250 *mid = p->private_data;
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int fisr = serial_port_in(p, INTEL_MID_UART_FISR);
+	u32 status;
+	int ret = 0;
+	int err;
+
+	if (fisr & BIT(2)) {
+		err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
+		if (err > 0) {
+			serial8250_rx_dma_flush(up);
+			ret |= 1;
+		} else if (err == 0)
+			ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status);
+	}
+	if (fisr & BIT(1)) {
+		err = hsu_dma_get_status(&mid->dma_chip, 0, &status);
+		if (err > 0)
+			ret |= 1;
+		else if (err == 0)
+			ret |= hsu_dma_do_irq(&mid->dma_chip, 0, status);
+	}
+	if (fisr & BIT(0))
+		ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
+	return IRQ_RETVAL(ret);
+}
+
+#define DNV_DMA_CHAN_OFFSET 0x80
+
+static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
+{
+	struct hsu_dma_chip *chip = &mid->dma_chip;
+	struct pci_dev *pdev = to_pci_dev(p->dev);
+	unsigned int bar = FL_GET_BASE(mid->board->flags);
+	int ret;
+
+	pci_set_master(pdev);
+
+	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
+	if (ret < 0)
+		return ret;
+
+	p->irq = pci_irq_vector(pdev, 0);
+
+	chip->dev = &pdev->dev;
+	chip->irq = pci_irq_vector(pdev, 0);
+	chip->regs = p->membase;
+	chip->length = pci_resource_len(pdev, bar);
+	chip->offset = DNV_DMA_CHAN_OFFSET;
+
+	/* Falling back to PIO mode if DMA probing fails */
+	ret = hsu_dma_probe(chip);
+	if (ret)
+		return 0;
+
+	mid->dma_dev = pdev;
+
+	p->handle_irq = dnv_handle_irq;
+	return 0;
+}
+
+static void dnv_exit(struct mid8250 *mid)
+{
+	if (!mid->dma_dev)
+		return;
+	hsu_dma_remove(&mid->dma_chip);
+}
+
+/*****************************************************************************/
+
+static void mid8250_set_termios(struct uart_port *p, struct ktermios *termios,
+				const struct ktermios *old)
+{
+	unsigned int baud = tty_termios_baud_rate(termios);
+	struct mid8250 *mid = p->private_data;
+	unsigned short ps = 16;
+	unsigned long fuart = baud * ps;
+	unsigned long w = BIT(24) - 1;
+	unsigned long mul, div;
+
+	/* Gracefully handle the B0 case: fall back to B9600 */
+	fuart = fuart ? fuart : 9600 * 16;
+
+	if (mid->board->freq < fuart) {
+		/* Find prescaler value that satisfies Fuart < Fref */
+		if (mid->board->freq > baud)
+			ps = mid->board->freq / baud;	/* baud rate too high */
+		else
+			ps = 1;				/* PLL case */
+		fuart = baud * ps;
+	} else {
+		/* Get Fuart closer to Fref */
+		fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
+	}
+
+	rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
+	p->uartclk = fuart * 16 / ps;		/* core uses ps = 16 always */
+
+	writel(ps, p->membase + INTEL_MID_UART_PS);		/* set PS */
+	writel(mul, p->membase + INTEL_MID_UART_MUL);		/* set MUL */
+	writel(div, p->membase + INTEL_MID_UART_DIV);
+
+	serial8250_do_set_termios(p, termios, old);
+}
+
+static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
+{
+	struct hsu_dma_slave *s = param;
+
+	if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
+		return false;
+
+	chan->private = s;
+	return true;
+}
+
+static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
+{
+	struct uart_8250_dma *dma = &mid->dma;
+	struct device *dev = port->port.dev;
+	struct hsu_dma_slave *rx_param;
+	struct hsu_dma_slave *tx_param;
+
+	if (!mid->dma_dev)
+		return 0;
+
+	rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
+	if (!rx_param)
+		return -ENOMEM;
+
+	tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
+	if (!tx_param)
+		return -ENOMEM;
+
+	rx_param->chan_id = mid->dma_index * 2 + 1;
+	tx_param->chan_id = mid->dma_index * 2;
+
+	dma->rxconf.src_maxburst = 64;
+	dma->txconf.dst_maxburst = 64;
+
+	rx_param->dma_dev = &mid->dma_dev->dev;
+	tx_param->dma_dev = &mid->dma_dev->dev;
+
+	dma->fn = mid8250_dma_filter;
+	dma->rx_param = rx_param;
+	dma->tx_param = tx_param;
+
+	port->dma = dma;
+	return 0;
+}
+
+static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct uart_8250_port uart;
+	struct mid8250 *mid;
+	unsigned int bar;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
+	if (!mid)
+		return -ENOMEM;
+
+	mid->board = (struct mid8250_board *)id->driver_data;
+	bar = FL_GET_BASE(mid->board->flags);
+
+	memset(&uart, 0, sizeof(struct uart_8250_port));
+
+	uart.port.dev = &pdev->dev;
+	uart.port.irq = pdev->irq;
+	uart.port.private_data = mid;
+	uart.port.type = PORT_16750;
+	uart.port.iotype = UPIO_MEM;
+	uart.port.uartclk = mid->board->base_baud * 16;
+	uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	uart.port.set_termios = mid8250_set_termios;
+
+	uart.port.mapbase = pci_resource_start(pdev, bar);
+	uart.port.membase = pcim_iomap(pdev, bar, 0);
+	if (!uart.port.membase)
+		return -ENOMEM;
+
+	ret = mid->board->setup(mid, &uart.port);
+	if (ret)
+		return ret;
+
+	ret = mid8250_dma_setup(mid, &uart);
+	if (ret)
+		goto err;
+
+	ret = serial8250_register_8250_port(&uart);
+	if (ret < 0)
+		goto err;
+
+	mid->line = ret;
+
+	pci_set_drvdata(pdev, mid);
+	return 0;
+
+err:
+	mid->board->exit(mid);
+	return ret;
+}
+
+static void mid8250_remove(struct pci_dev *pdev)
+{
+	struct mid8250 *mid = pci_get_drvdata(pdev);
+
+	serial8250_unregister_port(mid->line);
+
+	mid->board->exit(mid);
+}
+
+static const struct mid8250_board pnw_board = {
+	.flags = FL_BASE0,
+	.freq = 50000000,
+	.base_baud = 115200,
+	.setup = pnw_setup,
+	.exit = pnw_exit,
+};
+
+static const struct mid8250_board tng_board = {
+	.flags = FL_BASE0,
+	.freq = 38400000,
+	.base_baud = 1843200,
+	.setup = tng_setup,
+	.exit = tng_exit,
+};
+
+static const struct mid8250_board dnv_board = {
+	.flags = FL_BASE1,
+	.freq = 133333333,
+	.base_baud = 115200,
+	.setup = dnv_setup,
+	.exit = dnv_exit,
+};
+
+static const struct pci_device_id pci_ids[] = {
+	{ PCI_DEVICE_DATA(INTEL, PNW_UART1, &pnw_board) },
+	{ PCI_DEVICE_DATA(INTEL, PNW_UART2, &pnw_board) },
+	{ PCI_DEVICE_DATA(INTEL, PNW_UART3, &pnw_board) },
+	{ PCI_DEVICE_DATA(INTEL, TNG_UART, &tng_board) },
+	{ PCI_DEVICE_DATA(INTEL, CDF_UART, &dnv_board) },
+	{ PCI_DEVICE_DATA(INTEL, DNV_UART, &dnv_board) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+static struct pci_driver mid8250_pci_driver = {
+	.name           = "8250_mid",
+	.id_table       = pci_ids,
+	.probe          = mid8250_probe,
+	.remove         = mid8250_remove,
+};
+
+module_pci_driver(mid8250_pci_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel MID UART driver");
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
new file mode 100644
index 000000000..74da5676c
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -0,0 +1,677 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Mediatek 8250 driver.
+ *
+ * Copyright (c) 2014 MundoReader S.L.
+ * Author: Matthias Brugger <matthias.bgg@gmail.com>
+ */
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/console.h>
+#include <linux/dma-mapping.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#include "8250.h"
+
+#define MTK_UART_HIGHS		0x09	/* Highspeed register */
+#define MTK_UART_SAMPLE_COUNT	0x0a	/* Sample count register */
+#define MTK_UART_SAMPLE_POINT	0x0b	/* Sample point register */
+#define MTK_UART_RATE_FIX	0x0d	/* UART Rate Fix Register */
+#define MTK_UART_ESCAPE_DAT	0x10	/* Escape Character register */
+#define MTK_UART_ESCAPE_EN	0x11	/* Escape Enable register */
+#define MTK_UART_DMA_EN		0x13	/* DMA Enable register */
+#define MTK_UART_RXTRI_AD	0x14	/* RX Trigger address */
+#define MTK_UART_FRACDIV_L	0x15	/* Fractional divider LSB address */
+#define MTK_UART_FRACDIV_M	0x16	/* Fractional divider MSB address */
+#define MTK_UART_DEBUG0	0x18
+#define MTK_UART_IER_XOFFI	0x20	/* Enable XOFF character interrupt */
+#define MTK_UART_IER_RTSI	0x40	/* Enable RTS Modem status interrupt */
+#define MTK_UART_IER_CTSI	0x80	/* Enable CTS Modem status interrupt */
+
+#define MTK_UART_EFR		38	/* I/O: Extended Features Register */
+#define MTK_UART_EFR_EN		0x10	/* Enable enhancement feature */
+#define MTK_UART_EFR_RTS	0x40	/* Enable hardware rx flow control */
+#define MTK_UART_EFR_CTS	0x80	/* Enable hardware tx flow control */
+#define MTK_UART_EFR_NO_SW_FC	0x0	/* no sw flow control */
+#define MTK_UART_EFR_XON1_XOFF1	0xa	/* XON1/XOFF1 as sw flow control */
+#define MTK_UART_EFR_XON2_XOFF2	0x5	/* XON2/XOFF2 as sw flow control */
+#define MTK_UART_EFR_SW_FC_MASK	0xf	/* Enable CTS Modem status interrupt */
+#define MTK_UART_EFR_HW_FC	(MTK_UART_EFR_RTS | MTK_UART_EFR_CTS)
+#define MTK_UART_DMA_EN_TX	0x2
+#define MTK_UART_DMA_EN_RX	0x5
+
+#define MTK_UART_ESCAPE_CHAR	0x77	/* Escape char added under sw fc */
+#define MTK_UART_RX_SIZE	0x8000
+#define MTK_UART_TX_TRIGGER	1
+#define MTK_UART_RX_TRIGGER	MTK_UART_RX_SIZE
+
+#define MTK_UART_XON1		40	/* I/O: Xon character 1 */
+#define MTK_UART_XOFF1		42	/* I/O: Xoff character 1 */
+
+#ifdef CONFIG_SERIAL_8250_DMA
+enum dma_rx_status {
+	DMA_RX_START = 0,
+	DMA_RX_RUNNING = 1,
+	DMA_RX_SHUTDOWN = 2,
+};
+#endif
+
+struct mtk8250_data {
+	int			line;
+	unsigned int		rx_pos;
+	unsigned int		clk_count;
+	struct clk		*uart_clk;
+	struct clk		*bus_clk;
+	struct uart_8250_dma	*dma;
+#ifdef CONFIG_SERIAL_8250_DMA
+	enum dma_rx_status	rx_status;
+#endif
+	int			rx_wakeup_irq;
+};
+
+/* flow control mode */
+enum {
+	MTK_UART_FC_NONE,
+	MTK_UART_FC_SW,
+	MTK_UART_FC_HW,
+};
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static void mtk8250_rx_dma(struct uart_8250_port *up);
+
+static void mtk8250_dma_rx_complete(void *param)
+{
+	struct uart_8250_port *up = param;
+	struct uart_8250_dma *dma = up->dma;
+	struct mtk8250_data *data = up->port.private_data;
+	struct tty_port *tty_port = &up->port.state->port;
+	struct dma_tx_state state;
+	int copied, total, cnt;
+	unsigned char *ptr;
+	unsigned long flags;
+
+	if (data->rx_status == DMA_RX_SHUTDOWN)
+		return;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+	total = dma->rx_size - state.residue;
+	cnt = total;
+
+	if ((data->rx_pos + cnt) > dma->rx_size)
+		cnt = dma->rx_size - data->rx_pos;
+
+	ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+	copied = tty_insert_flip_string(tty_port, ptr, cnt);
+	data->rx_pos += cnt;
+
+	if (total > cnt) {
+		ptr = (unsigned char *)(dma->rx_buf);
+		cnt = total - cnt;
+		copied += tty_insert_flip_string(tty_port, ptr, cnt);
+		data->rx_pos = cnt;
+	}
+
+	up->port.icount.rx += copied;
+
+	tty_flip_buffer_push(tty_port);
+
+	mtk8250_rx_dma(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void mtk8250_rx_dma(struct uart_8250_port *up)
+{
+	struct uart_8250_dma *dma = up->dma;
+	struct dma_async_tx_descriptor	*desc;
+
+	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
+					   dma->rx_size, DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		pr_err("failed to prepare rx slave single\n");
+		return;
+	}
+
+	desc->callback = mtk8250_dma_rx_complete;
+	desc->callback_param = up;
+
+	dma->rx_cookie = dmaengine_submit(desc);
+
+	dma_async_issue_pending(dma->rxchan);
+}
+
+static void mtk8250_dma_enable(struct uart_8250_port *up)
+{
+	struct uart_8250_dma *dma = up->dma;
+	struct mtk8250_data *data = up->port.private_data;
+	int lcr = serial_in(up, UART_LCR);
+
+	if (data->rx_status != DMA_RX_START)
+		return;
+
+	dma->rxconf.src_port_window_size	= dma->rx_size;
+	dma->rxconf.src_addr				= dma->rx_addr;
+
+	dma->txconf.dst_port_window_size	= UART_XMIT_SIZE;
+	dma->txconf.dst_addr				= dma->tx_addr;
+
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+		UART_FCR_CLEAR_XMIT);
+	serial_out(up, MTK_UART_DMA_EN,
+		   MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
+	serial_out(up, UART_LCR, lcr);
+
+	if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
+		pr_err("failed to configure rx dma channel\n");
+	if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
+		pr_err("failed to configure tx dma channel\n");
+
+	data->rx_status = DMA_RX_RUNNING;
+	data->rx_pos = 0;
+	mtk8250_rx_dma(up);
+}
+#endif
+
+static int mtk8250_startup(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct mtk8250_data *data = port->private_data;
+
+	/* disable DMA for console */
+	if (uart_console(port))
+		up->dma = NULL;
+
+	if (up->dma) {
+		data->rx_status = DMA_RX_START;
+		uart_circ_clear(&port->state->xmit);
+	}
+#endif
+	memset(&port->icount, 0, sizeof(port->icount));
+
+	return serial8250_do_startup(port);
+}
+
+static void mtk8250_shutdown(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct mtk8250_data *data = port->private_data;
+
+	if (up->dma)
+		data->rx_status = DMA_RX_SHUTDOWN;
+#endif
+
+	return serial8250_do_shutdown(port);
+}
+
+static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
+}
+
+static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
+}
+
+static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
+{
+	struct uart_port *port = &up->port;
+	int lcr = serial_in(up, UART_LCR);
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&port->lock);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
+	serial_out(up, UART_LCR, lcr);
+	lcr = serial_in(up, UART_LCR);
+
+	switch (mode) {
+	case MTK_UART_FC_NONE:
+		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
+		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_out(up, MTK_UART_EFR, serial_in(up, MTK_UART_EFR) &
+			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));
+		serial_out(up, UART_LCR, lcr);
+		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |
+			MTK_UART_IER_RTSI | MTK_UART_IER_CTSI);
+		break;
+
+	case MTK_UART_FC_HW:
+		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
+		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
+		serial_out(up, UART_MCR, UART_MCR_RTS);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+		/*enable hw flow control*/
+		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_HW_FC |
+			(serial_in(up, MTK_UART_EFR) &
+			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
+
+		serial_out(up, UART_LCR, lcr);
+		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI);
+		mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI);
+		break;
+
+	case MTK_UART_FC_SW:	/*MTK software flow control */
+		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
+		serial_out(up, MTK_UART_ESCAPE_EN, 0x01);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+		/*enable sw flow control */
+		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
+			(serial_in(up, MTK_UART_EFR) &
+			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
+
+		serial_out(up, MTK_UART_XON1, START_CHAR(port->state->port.tty));
+		serial_out(up, MTK_UART_XOFF1, STOP_CHAR(port->state->port.tty));
+		serial_out(up, UART_LCR, lcr);
+		mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);
+		mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);
+		break;
+	default:
+		break;
+	}
+}
+
+static void
+mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
+		    const struct ktermios *old)
+{
+	static const unsigned short fraction_L_mapping[] = {
+		0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
+	};
+	static const unsigned short fraction_M_mapping[] = {
+		0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
+	};
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int baud, quot, fraction;
+	unsigned long flags;
+	int mode;
+
+#ifdef CONFIG_SERIAL_8250_DMA
+	if (up->dma) {
+		if (uart_console(port)) {
+			devm_kfree(up->port.dev, up->dma);
+			up->dma = NULL;
+		} else {
+			mtk8250_dma_enable(up);
+		}
+	}
+#endif
+
+	/*
+	 * Store the requested baud rate before calling the generic 8250
+	 * set_termios method. Standard 8250 port expects bauds to be
+	 * no higher than (uartclk / 16) so the baud will be clamped if it
+	 * gets out of that bound. Mediatek 8250 port supports speed
+	 * higher than that, therefore we'll get original baud rate back
+	 * after calling the generic set_termios method and recalculate
+	 * the speed later in this method.
+	 */
+	baud = tty_termios_baud_rate(termios);
+
+	serial8250_do_set_termios(port, termios, NULL);
+
+	tty_termios_encode_baud_rate(termios, baud, baud);
+
+	/*
+	 * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
+	 *
+	 * We need to recalcualte the quot register, as the claculation depends
+	 * on the vaule in the highspeed register.
+	 *
+	 * Some baudrates are not supported by the chip, so we use the next
+	 * lower rate supported and update termios c_flag.
+	 *
+	 * If highspeed register is set to 3, we need to specify sample count
+	 * and sample point to increase accuracy. If not, we reset the
+	 * registers to their default values.
+	 */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / 16 / UART_DIV_MAX,
+				  port->uartclk);
+
+	if (baud < 115200) {
+		serial_port_out(port, MTK_UART_HIGHS, 0x0);
+		quot = uart_get_divisor(port, baud);
+	} else {
+		serial_port_out(port, MTK_UART_HIGHS, 0x3);
+		quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
+	}
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* set DLAB we have cval saved in up->lcr from the call to the core */
+	serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
+	serial_dl_write(up, quot);
+
+	/* reset DLAB */
+	serial_port_out(port, UART_LCR, up->lcr);
+
+	if (baud >= 115200) {
+		unsigned int tmp;
+
+		tmp = (port->uartclk / (baud *  quot)) - 1;
+		serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
+		serial_port_out(port, MTK_UART_SAMPLE_POINT,
+					(tmp >> 1) - 1);
+
+		/*count fraction to set fractoin register */
+		fraction = ((port->uartclk  * 100) / baud / quot) % 100;
+		fraction = DIV_ROUND_CLOSEST(fraction, 10);
+		serial_port_out(port, MTK_UART_FRACDIV_L,
+						fraction_L_mapping[fraction]);
+		serial_port_out(port, MTK_UART_FRACDIV_M,
+						fraction_M_mapping[fraction]);
+	} else {
+		serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
+		serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
+		serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
+		serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
+	}
+
+	if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS)))
+		mode = MTK_UART_FC_HW;
+	else if (termios->c_iflag & CRTSCTS)
+		mode = MTK_UART_FC_SW;
+	else
+		mode = MTK_UART_FC_NONE;
+
+	mtk8250_set_flow_ctrl(up, mode);
+
+	if (uart_console(port))
+		up->port.cons->cflag = termios->c_cflag;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
+{
+	struct mtk8250_data *data = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(data->line);
+
+	/* wait until UART in idle status */
+	while
+		(serial_in(up, MTK_UART_DEBUG0));
+
+	clk_disable_unprepare(data->bus_clk);
+
+	return 0;
+}
+
+static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
+{
+	struct mtk8250_data *data = dev_get_drvdata(dev);
+
+	clk_prepare_enable(data->bus_clk);
+
+	return 0;
+}
+
+static void
+mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
+{
+	if (!state)
+		pm_runtime_get_sync(port->dev);
+
+	serial8250_do_pm(port, state, old);
+
+	if (state)
+		pm_runtime_put_sync_suspend(port->dev);
+}
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
+{
+	return false;
+}
+#endif
+
+static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
+			   struct mtk8250_data *data)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+	int dmacnt;
+#endif
+
+	data->uart_clk = devm_clk_get(&pdev->dev, "baud");
+	if (IS_ERR(data->uart_clk)) {
+		/*
+		 * For compatibility with older device trees try unnamed
+		 * clk when no baud clk can be found.
+		 */
+		data->uart_clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(data->uart_clk)) {
+			dev_warn(&pdev->dev, "Can't get uart clock\n");
+			return PTR_ERR(data->uart_clk);
+		}
+
+		return 0;
+	}
+
+	data->bus_clk = devm_clk_get_enabled(&pdev->dev, "bus");
+	if (IS_ERR(data->bus_clk))
+		return PTR_ERR(data->bus_clk);
+
+	data->dma = NULL;
+#ifdef CONFIG_SERIAL_8250_DMA
+	dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
+	if (dmacnt == 2) {
+		data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
+					 GFP_KERNEL);
+		if (!data->dma)
+			return -ENOMEM;
+
+		data->dma->fn = mtk8250_dma_filter;
+		data->dma->rx_size = MTK_UART_RX_SIZE;
+		data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
+		data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
+	}
+#endif
+
+	return 0;
+}
+
+static int mtk8250_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port uart = {};
+	struct mtk8250_data *data;
+	struct resource *regs;
+	int irq, err;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "no registers defined\n");
+		return -EINVAL;
+	}
+
+	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
+					 resource_size(regs));
+	if (!uart.port.membase)
+		return -ENOMEM;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk_count = 0;
+
+	if (pdev->dev.of_node) {
+		err = mtk8250_probe_of(pdev, &uart.port, data);
+		if (err)
+			return err;
+	} else
+		return -ENODEV;
+
+	spin_lock_init(&uart.port.lock);
+	uart.port.mapbase = regs->start;
+	uart.port.irq = irq;
+	uart.port.pm = mtk8250_do_pm;
+	uart.port.type = PORT_16550;
+	uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
+	uart.port.dev = &pdev->dev;
+	uart.port.iotype = UPIO_MEM32;
+	uart.port.regshift = 2;
+	uart.port.private_data = data;
+	uart.port.shutdown = mtk8250_shutdown;
+	uart.port.startup = mtk8250_startup;
+	uart.port.set_termios = mtk8250_set_termios;
+	uart.port.uartclk = clk_get_rate(data->uart_clk);
+#ifdef CONFIG_SERIAL_8250_DMA
+	if (data->dma)
+		uart.dma = data->dma;
+#endif
+
+	/* Disable Rate Fix function */
+	writel(0x0, uart.port.membase +
+			(MTK_UART_RATE_FIX << uart.port.regshift));
+
+	platform_set_drvdata(pdev, data);
+
+	data->line = serial8250_register_8250_port(&uart);
+	if (data->line < 0)
+		return data->line;
+
+	data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1);
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	return 0;
+}
+
+static int mtk8250_remove(struct platform_device *pdev)
+{
+	struct mtk8250_data *data = platform_get_drvdata(pdev);
+
+	pm_runtime_get_sync(&pdev->dev);
+
+	serial8250_unregister_port(data->line);
+
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused mtk8250_suspend(struct device *dev)
+{
+	struct mtk8250_data *data = dev_get_drvdata(dev);
+	int irq = data->rx_wakeup_irq;
+	int err;
+
+	serial8250_suspend_port(data->line);
+
+	pinctrl_pm_select_sleep_state(dev);
+	if (irq >= 0) {
+		err = enable_irq_wake(irq);
+		if (err) {
+			dev_err(dev,
+				"failed to enable irq wake on IRQ %d: %d\n",
+				irq, err);
+			pinctrl_pm_select_default_state(dev);
+			serial8250_resume_port(data->line);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int __maybe_unused mtk8250_resume(struct device *dev)
+{
+	struct mtk8250_data *data = dev_get_drvdata(dev);
+	int irq = data->rx_wakeup_irq;
+
+	if (irq >= 0)
+		disable_irq_wake(irq);
+	pinctrl_pm_select_default_state(dev);
+
+	serial8250_resume_port(data->line);
+
+	return 0;
+}
+
+static const struct dev_pm_ops mtk8250_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
+	SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
+				NULL)
+};
+
+static const struct of_device_id mtk8250_of_match[] = {
+	{ .compatible = "mediatek,mt6577-uart" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mtk8250_of_match);
+
+static struct platform_driver mtk8250_platform_driver = {
+	.driver = {
+		.name		= "mt6577-uart",
+		.pm		= &mtk8250_pm_ops,
+		.of_match_table	= mtk8250_of_match,
+	},
+	.probe			= mtk8250_probe,
+	.remove			= mtk8250_remove,
+};
+module_platform_driver(mtk8250_platform_driver);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static int __init early_mtk8250_setup(struct earlycon_device *device,
+					const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+	device->port.regshift = 2;
+
+	return early_serial8250_setup(device, NULL);
+}
+
+OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
+#endif
+
+MODULE_AUTHOR("Matthias Brugger");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Mediatek 8250 serial port driver");
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
new file mode 100644
index 000000000..51329625c
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -0,0 +1,359 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Serial Port driver for Open Firmware platform devices
+ *
+ *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
+ */
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+
+#include "8250.h"
+
+struct of_serial_info {
+	struct clk *clk;
+	struct reset_control *rst;
+	int type;
+	int line;
+};
+
+/*
+ * Fill a struct uart_port for a given device node
+ */
+static int of_platform_serial_setup(struct platform_device *ofdev,
+			int type, struct uart_8250_port *up,
+			struct of_serial_info *info)
+{
+	struct resource resource;
+	struct device_node *np = ofdev->dev.of_node;
+	struct uart_port *port = &up->port;
+	u32 clk, spd, prop;
+	int ret, irq;
+
+	memset(port, 0, sizeof *port);
+
+	pm_runtime_enable(&ofdev->dev);
+	pm_runtime_get_sync(&ofdev->dev);
+
+	if (of_property_read_u32(np, "clock-frequency", &clk)) {
+
+		/* Get clk rate through clk driver if present */
+		info->clk = devm_clk_get(&ofdev->dev, NULL);
+		if (IS_ERR(info->clk)) {
+			ret = PTR_ERR(info->clk);
+			if (ret != -EPROBE_DEFER)
+				dev_warn(&ofdev->dev,
+					 "failed to get clock: %d\n", ret);
+			goto err_pmruntime;
+		}
+
+		ret = clk_prepare_enable(info->clk);
+		if (ret < 0)
+			goto err_pmruntime;
+
+		clk = clk_get_rate(info->clk);
+	}
+	/* If current-speed was set, then try not to change it. */
+	if (of_property_read_u32(np, "current-speed", &spd) == 0)
+		port->custom_divisor = clk / (16 * spd);
+
+	ret = of_address_to_resource(np, 0, &resource);
+	if (ret) {
+		dev_warn(&ofdev->dev, "invalid address\n");
+		goto err_unprepare;
+	}
+
+	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
+				  UPF_FIXED_TYPE;
+	spin_lock_init(&port->lock);
+
+	if (resource_type(&resource) == IORESOURCE_IO) {
+		port->iotype = UPIO_PORT;
+		port->iobase = resource.start;
+	} else {
+		port->mapbase = resource.start;
+		port->mapsize = resource_size(&resource);
+
+		/* Check for shifted address mapping */
+		if (of_property_read_u32(np, "reg-offset", &prop) == 0) {
+			if (prop >= port->mapsize) {
+				dev_warn(&ofdev->dev, "reg-offset %u exceeds region size %pa\n",
+					 prop, &port->mapsize);
+				ret = -EINVAL;
+				goto err_unprepare;
+			}
+
+			port->mapbase += prop;
+			port->mapsize -= prop;
+		}
+
+		port->iotype = UPIO_MEM;
+		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
+			switch (prop) {
+			case 1:
+				port->iotype = UPIO_MEM;
+				break;
+			case 2:
+				port->iotype = UPIO_MEM16;
+				break;
+			case 4:
+				port->iotype = of_device_is_big_endian(np) ?
+					       UPIO_MEM32BE : UPIO_MEM32;
+				break;
+			default:
+				dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
+					 prop);
+				ret = -EINVAL;
+				goto err_unprepare;
+			}
+		}
+		port->flags |= UPF_IOREMAP;
+	}
+
+	/* Compatibility with the deprecated pxa driver and 8250_pxa drivers. */
+	if (of_device_is_compatible(np, "mrvl,mmp-uart"))
+		port->regshift = 2;
+
+	/* Check for registers offset within the devices address range */
+	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
+		port->regshift = prop;
+
+	/* Check for fifo size */
+	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
+		port->fifosize = prop;
+
+	/* Check for a fixed line number */
+	ret = of_alias_get_id(np, "serial");
+	if (ret >= 0)
+		port->line = ret;
+
+	irq = of_irq_get(np, 0);
+	if (irq < 0) {
+		if (irq == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto err_unprepare;
+		}
+		/* IRQ support not mandatory */
+		irq = 0;
+	}
+
+	port->irq = irq;
+
+	info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
+	if (IS_ERR(info->rst)) {
+		ret = PTR_ERR(info->rst);
+		goto err_unprepare;
+	}
+
+	ret = reset_control_deassert(info->rst);
+	if (ret)
+		goto err_unprepare;
+
+	port->type = type;
+	port->uartclk = clk;
+
+	if (of_property_read_bool(np, "no-loopback-test"))
+		port->flags |= UPF_SKIP_TEST;
+
+	port->dev = &ofdev->dev;
+	port->rs485_config = serial8250_em485_config;
+	port->rs485_supported = serial8250_em485_supported;
+	up->rs485_start_tx = serial8250_em485_start_tx;
+	up->rs485_stop_tx = serial8250_em485_stop_tx;
+
+	switch (type) {
+	case PORT_RT2880:
+		ret = rt288x_setup(port);
+		if (ret)
+			goto err_unprepare;
+		break;
+	}
+
+	if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL) &&
+	    (of_device_is_compatible(np, "fsl,ns16550") ||
+	     of_device_is_compatible(np, "fsl,16550-FIFO64"))) {
+		port->handle_irq = fsl8250_handle_irq;
+		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+	}
+
+	return 0;
+err_unprepare:
+	clk_disable_unprepare(info->clk);
+err_pmruntime:
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	return ret;
+}
+
+/*
+ * Try to register a serial port
+ */
+static int of_platform_serial_probe(struct platform_device *ofdev)
+{
+	struct of_serial_info *info;
+	struct uart_8250_port port8250;
+	unsigned int port_type;
+	u32 tx_threshold;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_SERIAL_8250_BCM7271) &&
+	    of_device_is_compatible(ofdev->dev.of_node, "brcm,bcm7271-uart"))
+		return -ENODEV;
+
+	port_type = (unsigned long)of_device_get_match_data(&ofdev->dev);
+	if (port_type == PORT_UNKNOWN)
+		return -EINVAL;
+
+	if (of_property_read_bool(ofdev->dev.of_node, "used-by-rtas"))
+		return -EBUSY;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (info == NULL)
+		return -ENOMEM;
+
+	memset(&port8250, 0, sizeof(port8250));
+	ret = of_platform_serial_setup(ofdev, port_type, &port8250, info);
+	if (ret)
+		goto err_free;
+
+	if (port8250.port.fifosize)
+		port8250.capabilities = UART_CAP_FIFO;
+
+	/* Check for TX FIFO threshold & set tx_loadsz */
+	if ((of_property_read_u32(ofdev->dev.of_node, "tx-threshold",
+				  &tx_threshold) == 0) &&
+	    (tx_threshold < port8250.port.fifosize))
+		port8250.tx_loadsz = port8250.port.fifosize - tx_threshold;
+
+	if (of_property_read_bool(ofdev->dev.of_node, "auto-flow-control"))
+		port8250.capabilities |= UART_CAP_AFE;
+
+	if (of_property_read_u32(ofdev->dev.of_node,
+			"overrun-throttle-ms",
+			&port8250.overrun_backoff_time_ms) != 0)
+		port8250.overrun_backoff_time_ms = 0;
+
+	ret = serial8250_register_8250_port(&port8250);
+	if (ret < 0)
+		goto err_dispose;
+
+	info->type = port_type;
+	info->line = ret;
+	platform_set_drvdata(ofdev, info);
+	return 0;
+err_dispose:
+	irq_dispose_mapping(port8250.port.irq);
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	clk_disable_unprepare(info->clk);
+err_free:
+	kfree(info);
+	return ret;
+}
+
+/*
+ * Release a line
+ */
+static int of_platform_serial_remove(struct platform_device *ofdev)
+{
+	struct of_serial_info *info = platform_get_drvdata(ofdev);
+
+	serial8250_unregister_port(info->line);
+
+	reset_control_assert(info->rst);
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	clk_disable_unprepare(info->clk);
+	kfree(info);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int of_serial_suspend(struct device *dev)
+{
+	struct of_serial_info *info = dev_get_drvdata(dev);
+	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+	struct uart_port *port = &port8250->port;
+
+	serial8250_suspend_port(info->line);
+
+	if (!uart_console(port) || console_suspend_enabled) {
+		pm_runtime_put_sync(dev);
+		clk_disable_unprepare(info->clk);
+	}
+	return 0;
+}
+
+static int of_serial_resume(struct device *dev)
+{
+	struct of_serial_info *info = dev_get_drvdata(dev);
+	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+	struct uart_port *port = &port8250->port;
+
+	if (!uart_console(port) || console_suspend_enabled) {
+		pm_runtime_get_sync(dev);
+		clk_prepare_enable(info->clk);
+	}
+
+	serial8250_resume_port(info->line);
+
+	return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume);
+
+/*
+ * A few common types, add more as needed.
+ */
+static const struct of_device_id of_platform_serial_table[] = {
+	{ .compatible = "ns8250",   .data = (void *)PORT_8250, },
+	{ .compatible = "ns16450",  .data = (void *)PORT_16450, },
+	{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },
+	{ .compatible = "ns16550",  .data = (void *)PORT_16550, },
+	{ .compatible = "ns16750",  .data = (void *)PORT_16750, },
+	{ .compatible = "ns16850",  .data = (void *)PORT_16850, },
+	{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
+	{ .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, },
+	{ .compatible = "intel,xscale-uart", .data = (void *)PORT_XSCALE, },
+	{ .compatible = "altr,16550-FIFO32",
+		.data = (void *)PORT_ALTR_16550_F32, },
+	{ .compatible = "altr,16550-FIFO64",
+		.data = (void *)PORT_ALTR_16550_F64, },
+	{ .compatible = "altr,16550-FIFO128",
+		.data = (void *)PORT_ALTR_16550_F128, },
+	{ .compatible = "fsl,16550-FIFO64",
+		.data = (void *)PORT_16550A_FSL64, },
+	{ .compatible = "mediatek,mtk-btif",
+		.data = (void *)PORT_MTK_BTIF, },
+	{ .compatible = "mrvl,mmp-uart",
+		.data = (void *)PORT_XSCALE, },
+	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
+	{ .compatible = "nuvoton,wpcm450-uart", .data = (void *)PORT_NPCM, },
+	{ .compatible = "nuvoton,npcm750-uart", .data = (void *)PORT_NPCM, },
+	{ /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, of_platform_serial_table);
+
+static struct platform_driver of_platform_serial_driver = {
+	.driver = {
+		.name = "of_serial",
+		.of_match_table = of_platform_serial_table,
+		.pm = &of_serial_pm_ops,
+	},
+	.probe = of_platform_serial_probe,
+	.remove = of_platform_serial_remove,
+};
+
+module_platform_driver(of_platform_serial_driver);
+
+MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
new file mode 100644
index 000000000..346167afe
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -0,0 +1,1838 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 8250-core based driver for the OMAP internal UART
+ *
+ * based on omap-serial.c, Copyright (C) 2010 Texas Instruments.
+ *
+ * Copyright (C) 2014 Sebastian Andrzej Siewior
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/tty_flip.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_irq.h>
+#include <linux/delay.h>
+#include <linux/pm_runtime.h>
+#include <linux/console.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/dma-mapping.h>
+#include <linux/sys_soc.h>
+
+#include "8250.h"
+
+#define DEFAULT_CLK_SPEED	48000000
+#define OMAP_UART_REGSHIFT	2
+
+#define UART_ERRATA_i202_MDR1_ACCESS	(1 << 0)
+#define OMAP_UART_WER_HAS_TX_WAKEUP	(1 << 1)
+#define OMAP_DMA_TX_KICK		(1 << 2)
+/*
+ * See Advisory 21 in AM437x errata SPRZ408B, updated April 2015.
+ * The same errata is applicable to AM335x and DRA7x processors too.
+ */
+#define UART_ERRATA_CLOCK_DISABLE	(1 << 3)
+#define	UART_HAS_EFR2			BIT(4)
+#define UART_HAS_RHR_IT_DIS		BIT(5)
+#define UART_RX_TIMEOUT_QUIRK		BIT(6)
+#define UART_HAS_NATIVE_RS485		BIT(7)
+
+#define OMAP_UART_FCR_RX_TRIG		6
+#define OMAP_UART_FCR_TX_TRIG		4
+
+/* SCR register bitmasks */
+#define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK	(1 << 7)
+#define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK	(1 << 6)
+#define OMAP_UART_SCR_TX_EMPTY			(1 << 3)
+#define OMAP_UART_SCR_DMAMODE_MASK		(3 << 1)
+#define OMAP_UART_SCR_DMAMODE_1			(1 << 1)
+#define OMAP_UART_SCR_DMAMODE_CTL		(1 << 0)
+
+/* MVR register bitmasks */
+#define OMAP_UART_MVR_SCHEME_SHIFT	30
+#define OMAP_UART_LEGACY_MVR_MAJ_MASK	0xf0
+#define OMAP_UART_LEGACY_MVR_MAJ_SHIFT	4
+#define OMAP_UART_LEGACY_MVR_MIN_MASK	0x0f
+#define OMAP_UART_MVR_MAJ_MASK		0x700
+#define OMAP_UART_MVR_MAJ_SHIFT		8
+#define OMAP_UART_MVR_MIN_MASK		0x3f
+
+/* SYSC register bitmasks */
+#define OMAP_UART_SYSC_SOFTRESET	(1 << 1)
+
+/* SYSS register bitmasks */
+#define OMAP_UART_SYSS_RESETDONE	(1 << 0)
+
+#define UART_TI752_TLR_TX	0
+#define UART_TI752_TLR_RX	4
+
+#define TRIGGER_TLR_MASK(x)	((x & 0x3c) >> 2)
+#define TRIGGER_FCR_MASK(x)	(x & 3)
+
+/* Enable XON/XOFF flow control on output */
+#define OMAP_UART_SW_TX		0x08
+/* Enable XON/XOFF flow control on input */
+#define OMAP_UART_SW_RX		0x02
+
+#define OMAP_UART_WER_MOD_WKUP	0x7f
+#define OMAP_UART_TX_WAKEUP_EN	(1 << 7)
+
+#define TX_TRIGGER	1
+#define RX_TRIGGER	48
+
+#define OMAP_UART_TCR_RESTORE(x)	((x / 4) << 4)
+#define OMAP_UART_TCR_HALT(x)		((x / 4) << 0)
+
+#define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
+
+#define OMAP_UART_REV_46 0x0406
+#define OMAP_UART_REV_52 0x0502
+#define OMAP_UART_REV_63 0x0603
+
+/* Interrupt Enable Register 2 */
+#define UART_OMAP_IER2			0x1B
+#define UART_OMAP_IER2_RHR_IT_DIS	BIT(2)
+
+/* Mode Definition Register 3 */
+#define UART_OMAP_MDR3			0x20
+#define UART_OMAP_MDR3_DIR_POL		BIT(3)
+#define UART_OMAP_MDR3_DIR_EN		BIT(4)
+
+/* Enhanced features register 2 */
+#define UART_OMAP_EFR2			0x23
+#define UART_OMAP_EFR2_TIMEOUT_BEHAVE	BIT(6)
+
+/* RX FIFO occupancy indicator */
+#define UART_OMAP_RX_LVL		0x19
+
+struct omap8250_priv {
+	void __iomem *membase;
+	int line;
+	u8 habit;
+	u8 mdr1;
+	u8 mdr3;
+	u8 efr;
+	u8 scr;
+	u8 wer;
+	u8 xon;
+	u8 xoff;
+	u8 delayed_restore;
+	u16 quot;
+
+	u8 tx_trigger;
+	u8 rx_trigger;
+	bool is_suspending;
+	int wakeirq;
+	int wakeups_enabled;
+	u32 latency;
+	u32 calc_latency;
+	struct pm_qos_request pm_qos_request;
+	struct work_struct qos_work;
+	struct uart_8250_dma omap8250_dma;
+	spinlock_t rx_dma_lock;
+	bool rx_dma_broken;
+	bool throttled;
+};
+
+struct omap8250_dma_params {
+	u32 rx_size;
+	u8 rx_trigger;
+	u8 tx_trigger;
+};
+
+struct omap8250_platdata {
+	struct omap8250_dma_params *dma_params;
+	u8 habit;
+};
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static void omap_8250_rx_dma_flush(struct uart_8250_port *p);
+#else
+static inline void omap_8250_rx_dma_flush(struct uart_8250_port *p) { }
+#endif
+
+static u32 uart_read(struct omap8250_priv *priv, u32 reg)
+{
+	return readl(priv->membase + (reg << OMAP_UART_REGSHIFT));
+}
+
+/*
+ * Called on runtime PM resume path from omap8250_restore_regs(), and
+ * omap8250_set_mctrl().
+ */
+static void __omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = up->port.private_data;
+	u8 lcr;
+
+	serial8250_do_set_mctrl(port, mctrl);
+
+	if (!mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS)) {
+		/*
+		 * Turn off autoRTS if RTS is lowered and restore autoRTS
+		 * setting if RTS is raised
+		 */
+		lcr = serial_in(up, UART_LCR);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+			priv->efr |= UART_EFR_RTS;
+		else
+			priv->efr &= ~UART_EFR_RTS;
+		serial_out(up, UART_EFR, priv->efr);
+		serial_out(up, UART_LCR, lcr);
+	}
+}
+
+static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	int err;
+
+	err = pm_runtime_resume_and_get(port->dev);
+	if (err)
+		return;
+
+	__omap8250_set_mctrl(port, mctrl);
+
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+}
+
+/*
+ * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
+ * The access to uart register after MDR1 Access
+ * causes UART to corrupt data.
+ *
+ * Need a delay =
+ * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
+ * give 10 times as much
+ */
+static void omap_8250_mdr1_errataset(struct uart_8250_port *up,
+				     struct omap8250_priv *priv)
+{
+	serial_out(up, UART_OMAP_MDR1, priv->mdr1);
+	udelay(2);
+	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
+			UART_FCR_CLEAR_RCVR);
+}
+
+static void omap_8250_get_divisor(struct uart_port *port, unsigned int baud,
+				  struct omap8250_priv *priv)
+{
+	unsigned int uartclk = port->uartclk;
+	unsigned int div_13, div_16;
+	unsigned int abs_d13, abs_d16;
+
+	/*
+	 * Old custom speed handling.
+	 */
+	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) {
+		priv->quot = port->custom_divisor & UART_DIV_MAX;
+		/*
+		 * I assume that nobody is using this. But hey, if somebody
+		 * would like to specify the divisor _and_ the mode then the
+		 * driver is ready and waiting for it.
+		 */
+		if (port->custom_divisor & (1 << 16))
+			priv->mdr1 = UART_OMAP_MDR1_13X_MODE;
+		else
+			priv->mdr1 = UART_OMAP_MDR1_16X_MODE;
+		return;
+	}
+	div_13 = DIV_ROUND_CLOSEST(uartclk, 13 * baud);
+	div_16 = DIV_ROUND_CLOSEST(uartclk, 16 * baud);
+
+	if (!div_13)
+		div_13 = 1;
+	if (!div_16)
+		div_16 = 1;
+
+	abs_d13 = abs(baud - uartclk / 13 / div_13);
+	abs_d16 = abs(baud - uartclk / 16 / div_16);
+
+	if (abs_d13 >= abs_d16) {
+		priv->mdr1 = UART_OMAP_MDR1_16X_MODE;
+		priv->quot = div_16;
+	} else {
+		priv->mdr1 = UART_OMAP_MDR1_13X_MODE;
+		priv->quot = div_13;
+	}
+}
+
+static void omap8250_update_scr(struct uart_8250_port *up,
+				struct omap8250_priv *priv)
+{
+	u8 old_scr;
+
+	old_scr = serial_in(up, UART_OMAP_SCR);
+	if (old_scr == priv->scr)
+		return;
+
+	/*
+	 * The manual recommends not to enable the DMA mode selector in the SCR
+	 * (instead of the FCR) register _and_ selecting the DMA mode as one
+	 * register write because this may lead to malfunction.
+	 */
+	if (priv->scr & OMAP_UART_SCR_DMAMODE_MASK)
+		serial_out(up, UART_OMAP_SCR,
+			   priv->scr & ~OMAP_UART_SCR_DMAMODE_MASK);
+	serial_out(up, UART_OMAP_SCR, priv->scr);
+}
+
+static void omap8250_update_mdr1(struct uart_8250_port *up,
+				 struct omap8250_priv *priv)
+{
+	if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS)
+		omap_8250_mdr1_errataset(up, priv);
+	else
+		serial_out(up, UART_OMAP_MDR1, priv->mdr1);
+}
+
+static void omap8250_restore_regs(struct uart_8250_port *up)
+{
+	struct omap8250_priv *priv = up->port.private_data;
+	struct uart_8250_dma	*dma = up->dma;
+	u8 mcr = serial8250_in_MCR(up);
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	if (dma && dma->tx_running) {
+		/*
+		 * TCSANOW requests the change to occur immediately however if
+		 * we have a TX-DMA operation in progress then it has been
+		 * observed that it might stall and never complete. Therefore we
+		 * delay DMA completes to prevent this hang from happen.
+		 */
+		priv->delayed_restore = 1;
+		return;
+	}
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, UART_EFR_ECB);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial8250_out_MCR(up, mcr | UART_MCR_TCRTLR);
+	serial_out(up, UART_FCR, up->fcr);
+
+	omap8250_update_scr(up, priv);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_RESTORE(16) |
+			OMAP_UART_TCR_HALT(52));
+	serial_out(up, UART_TI752_TLR,
+		   TRIGGER_TLR_MASK(priv->tx_trigger) << UART_TI752_TLR_TX |
+		   TRIGGER_TLR_MASK(priv->rx_trigger) << UART_TI752_TLR_RX);
+
+	serial_out(up, UART_LCR, 0);
+
+	/* drop TCR + TLR access, we setup XON/XOFF later */
+	serial8250_out_MCR(up, mcr);
+
+	serial_out(up, UART_IER, up->ier);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_dl_write(up, priv->quot);
+
+	serial_out(up, UART_EFR, priv->efr);
+
+	/* Configure flow control */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_XON1, priv->xon);
+	serial_out(up, UART_XOFF1, priv->xoff);
+
+	serial_out(up, UART_LCR, up->lcr);
+
+	omap8250_update_mdr1(up, priv);
+
+	__omap8250_set_mctrl(&up->port, up->port.mctrl);
+
+	serial_out(up, UART_OMAP_MDR3, priv->mdr3);
+
+	if (up->port.rs485.flags & SER_RS485_ENABLED &&
+	    up->port.rs485_config == serial8250_em485_config)
+		serial8250_em485_stop_tx(up);
+}
+
+/*
+ * OMAP can use "CLK / (16 or 13) / div" for baud rate. And then we have have
+ * some differences in how we want to handle flow control.
+ */
+static void omap_8250_set_termios(struct uart_port *port,
+				  struct ktermios *termios,
+				  const struct ktermios *old)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = up->port.private_data;
+	unsigned char cval = 0;
+	unsigned int baud;
+
+	cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+	if (termios->c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (termios->c_cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(termios->c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	if (termios->c_cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / 16 / UART_DIV_MAX,
+				  port->uartclk / 13);
+	omap_8250_get_divisor(port, baud, priv);
+
+	/*
+	 * Ok, we're now changing the port state. Do it with
+	 * interrupts disabled.
+	 */
+	pm_runtime_get_sync(port->dev);
+	spin_lock_irq(&port->lock);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (IGNBRK | PARMRK))
+		up->port.read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * Modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+
+	up->lcr = cval;
+	/* Up to here it was mostly serial8250_do_set_termios() */
+
+	/*
+	 * We enable TRIG_GRANU for RX and TX and additionally we set
+	 * SCR_TX_EMPTY bit. The result is the following:
+	 * - RX_TRIGGER amount of bytes in the FIFO will cause an interrupt.
+	 * - less than RX_TRIGGER number of bytes will also cause an interrupt
+	 *   once the UART decides that there no new bytes arriving.
+	 * - Once THRE is enabled, the interrupt will be fired once the FIFO is
+	 *   empty - the trigger level is ignored here.
+	 *
+	 * Once DMA is enabled:
+	 * - UART will assert the TX DMA line once there is room for TX_TRIGGER
+	 *   bytes in the TX FIFO. On each assert the DMA engine will move
+	 *   TX_TRIGGER bytes into the FIFO.
+	 * - UART will assert the RX DMA line once there are RX_TRIGGER bytes in
+	 *   the FIFO and move RX_TRIGGER bytes.
+	 * This is because threshold and trigger values are the same.
+	 */
+	up->fcr = UART_FCR_ENABLE_FIFO;
+	up->fcr |= TRIGGER_FCR_MASK(priv->tx_trigger) << OMAP_UART_FCR_TX_TRIG;
+	up->fcr |= TRIGGER_FCR_MASK(priv->rx_trigger) << OMAP_UART_FCR_RX_TRIG;
+
+	priv->scr = OMAP_UART_SCR_RX_TRIG_GRANU1_MASK | OMAP_UART_SCR_TX_EMPTY |
+		OMAP_UART_SCR_TX_TRIG_GRANU1_MASK;
+
+	if (up->dma)
+		priv->scr |= OMAP_UART_SCR_DMAMODE_1 |
+			OMAP_UART_SCR_DMAMODE_CTL;
+
+	priv->xon = termios->c_cc[VSTART];
+	priv->xoff = termios->c_cc[VSTOP];
+
+	priv->efr = 0;
+	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
+
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW &&
+	    !mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS) &&
+	    !mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_CTS)) {
+		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
+		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+		priv->efr |= UART_EFR_CTS;
+	} else	if (up->port.flags & UPF_SOFT_FLOW) {
+		/*
+		 * OMAP rx s/w flow control is borked; the transmitter remains
+		 * stuck off even if rx flow control is subsequently disabled
+		 */
+
+		/*
+		 * IXOFF Flag:
+		 * Enable XON/XOFF flow control on output.
+		 * Transmit XON1, XOFF1
+		 */
+		if (termios->c_iflag & IXOFF) {
+			up->port.status |= UPSTAT_AUTOXOFF;
+			priv->efr |= OMAP_UART_SW_TX;
+		}
+	}
+	omap8250_restore_regs(up);
+
+	spin_unlock_irq(&up->port.lock);
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+
+	/* calculate wakeup latency constraint */
+	priv->calc_latency = USEC_PER_SEC * 64 * 8 / baud;
+	priv->latency = priv->calc_latency;
+
+	schedule_work(&priv->qos_work);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+/* same as 8250 except that we may have extra flow bits set in EFR */
+static void omap_8250_pm(struct uart_port *port, unsigned int state,
+			 unsigned int oldstate)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	u8 efr;
+
+	pm_runtime_get_sync(port->dev);
+
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irq(&port->lock);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, efr);
+	serial_out(up, UART_LCR, 0);
+
+	spin_unlock_irq(&port->lock);
+
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+}
+
+static void omap_serial_fill_features_erratas(struct uart_8250_port *up,
+					      struct omap8250_priv *priv)
+{
+	static const struct soc_device_attribute k3_soc_devices[] = {
+		{ .family = "AM65X",  },
+		{ .family = "J721E", .revision = "SR1.0" },
+		{ /* sentinel */ }
+	};
+	u32 mvr, scheme;
+	u16 revision, major, minor;
+
+	mvr = uart_read(priv, UART_OMAP_MVER);
+
+	/* Check revision register scheme */
+	scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
+
+	switch (scheme) {
+	case 0: /* Legacy Scheme: OMAP2/3 */
+		/* MINOR_REV[0:4], MAJOR_REV[4:7] */
+		major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
+			OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
+		minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
+		break;
+	case 1:
+		/* New Scheme: OMAP4+ */
+		/* MINOR_REV[0:5], MAJOR_REV[8:10] */
+		major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
+			OMAP_UART_MVR_MAJ_SHIFT;
+		minor = (mvr & OMAP_UART_MVR_MIN_MASK);
+		break;
+	default:
+		dev_warn(up->port.dev,
+			 "Unknown revision, defaulting to highest\n");
+		/* highest possible revision */
+		major = 0xff;
+		minor = 0xff;
+	}
+	/* normalize revision for the driver */
+	revision = UART_BUILD_REVISION(major, minor);
+
+	switch (revision) {
+	case OMAP_UART_REV_46:
+		priv->habit |= UART_ERRATA_i202_MDR1_ACCESS;
+		break;
+	case OMAP_UART_REV_52:
+		priv->habit |= UART_ERRATA_i202_MDR1_ACCESS |
+				OMAP_UART_WER_HAS_TX_WAKEUP;
+		break;
+	case OMAP_UART_REV_63:
+		priv->habit |= UART_ERRATA_i202_MDR1_ACCESS |
+			OMAP_UART_WER_HAS_TX_WAKEUP;
+		break;
+	default:
+		break;
+	}
+
+	/*
+	 * AM65x SR1.0, AM65x SR2.0 and J721e SR1.0 don't
+	 * don't have RHR_IT_DIS bit in IER2 register. So drop to flag
+	 * to enable errata workaround.
+	 */
+	if (soc_device_match(k3_soc_devices))
+		priv->habit &= ~UART_HAS_RHR_IT_DIS;
+}
+
+static void omap8250_uart_qos_work(struct work_struct *work)
+{
+	struct omap8250_priv *priv;
+
+	priv = container_of(work, struct omap8250_priv, qos_work);
+	cpu_latency_qos_update_request(&priv->pm_qos_request, priv->latency);
+}
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static int omap_8250_dma_handle_irq(struct uart_port *port);
+#endif
+
+static irqreturn_t omap8250_irq(int irq, void *dev_id)
+{
+	struct omap8250_priv *priv = dev_id;
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+	struct uart_port *port = &up->port;
+	unsigned int iir, lsr;
+	int ret;
+
+#ifdef CONFIG_SERIAL_8250_DMA
+	if (up->dma) {
+		ret = omap_8250_dma_handle_irq(port);
+		return IRQ_RETVAL(ret);
+	}
+#endif
+
+	serial8250_rpm_get(up);
+	lsr = serial_port_in(port, UART_LSR);
+	iir = serial_port_in(port, UART_IIR);
+	ret = serial8250_handle_irq(port, iir);
+
+	/*
+	 * On K3 SoCs, it is observed that RX TIMEOUT is signalled after
+	 * FIFO has been drained, in which case a dummy read of RX FIFO
+	 * is required to clear RX TIMEOUT condition.
+	 */
+	if (priv->habit & UART_RX_TIMEOUT_QUIRK &&
+	    (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT &&
+	    serial_port_in(port, UART_OMAP_RX_LVL) == 0) {
+		serial_port_in(port, UART_RX);
+	}
+
+	/* Stop processing interrupts on input overrun */
+	if ((lsr & UART_LSR_OE) && up->overrun_backoff_time_ms > 0) {
+		unsigned long delay;
+
+		/* Synchronize UART_IER access against the console. */
+		spin_lock(&port->lock);
+		up->ier = port->serial_in(port, UART_IER);
+		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
+			port->ops->stop_rx(port);
+		} else {
+			/* Keep restarting the timer until
+			 * the input overrun subsides.
+			 */
+			cancel_delayed_work(&up->overrun_backoff);
+		}
+		spin_unlock(&port->lock);
+
+		delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
+		schedule_delayed_work(&up->overrun_backoff, delay);
+	}
+
+	serial8250_rpm_put(up);
+
+	return IRQ_RETVAL(ret);
+}
+
+static int omap_8250_startup(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = port->private_data;
+	struct uart_8250_dma *dma = &priv->omap8250_dma;
+	int ret;
+
+	if (priv->wakeirq) {
+		ret = dev_pm_set_dedicated_wake_irq(port->dev, priv->wakeirq);
+		if (ret)
+			return ret;
+	}
+
+	pm_runtime_get_sync(port->dev);
+
+	serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
+
+	up->lsr_saved_flags = 0;
+	up->msr_saved_flags = 0;
+
+	/* Disable DMA for console UART */
+	if (dma->fn && !uart_console(port)) {
+		up->dma = &priv->omap8250_dma;
+		ret = serial8250_request_dma(up);
+		if (ret) {
+			dev_warn_ratelimited(port->dev,
+					     "failed to request DMA\n");
+			up->dma = NULL;
+		}
+	} else {
+		up->dma = NULL;
+	}
+
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irq(&port->lock);
+	up->ier = UART_IER_RLSI | UART_IER_RDI;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irq(&port->lock);
+
+#ifdef CONFIG_PM
+	up->capabilities |= UART_CAP_RPM;
+#endif
+
+	/* Enable module level wake up */
+	priv->wer = OMAP_UART_WER_MOD_WKUP;
+	if (priv->habit & OMAP_UART_WER_HAS_TX_WAKEUP)
+		priv->wer |= OMAP_UART_TX_WAKEUP_EN;
+	serial_out(up, UART_OMAP_WER, priv->wer);
+
+	if (up->dma && !(priv->habit & UART_HAS_EFR2)) {
+		spin_lock_irq(&port->lock);
+		up->dma->rx_dma(up);
+		spin_unlock_irq(&port->lock);
+	}
+
+	enable_irq(up->port.irq);
+
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+	return 0;
+}
+
+static void omap_8250_shutdown(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = port->private_data;
+
+	flush_work(&priv->qos_work);
+	if (up->dma)
+		omap_8250_rx_dma_flush(up);
+
+	pm_runtime_get_sync(port->dev);
+
+	serial_out(up, UART_OMAP_WER, 0);
+	if (priv->habit & UART_HAS_EFR2)
+		serial_out(up, UART_OMAP_EFR2, 0x0);
+
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irq(&port->lock);
+	up->ier = 0;
+	serial_out(up, UART_IER, 0);
+	spin_unlock_irq(&port->lock);
+	disable_irq_nosync(up->port.irq);
+	dev_pm_clear_wake_irq(port->dev);
+
+	serial8250_release_dma(up);
+	up->dma = NULL;
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	if (up->lcr & UART_LCR_SBC)
+		serial_out(up, UART_LCR, up->lcr & ~UART_LCR_SBC);
+	serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+}
+
+static void omap_8250_throttle(struct uart_port *port)
+{
+	struct omap8250_priv *priv = port->private_data;
+	unsigned long flags;
+
+	pm_runtime_get_sync(port->dev);
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->ops->stop_rx(port);
+	priv->throttled = true;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+}
+
+static void omap_8250_unthrottle(struct uart_port *port)
+{
+	struct omap8250_priv *priv = port->private_data;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	pm_runtime_get_sync(port->dev);
+
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irqsave(&port->lock, flags);
+	priv->throttled = false;
+	if (up->dma)
+		up->dma->rx_dma(up);
+	up->ier |= UART_IER_RLSI | UART_IER_RDI;
+	port->read_status_mask |= UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	pm_runtime_mark_last_busy(port->dev);
+	pm_runtime_put_autosuspend(port->dev);
+}
+
+static int omap8250_rs485_config(struct uart_port *port,
+				 struct ktermios *termios,
+				 struct serial_rs485 *rs485)
+{
+	struct omap8250_priv *priv = port->private_data;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	u32 fixed_delay_rts_before_send = 0;
+	u32 fixed_delay_rts_after_send = 0;
+	unsigned int baud;
+
+	/*
+	 * There is a fixed delay of 3 bit clock cycles after the TX shift
+	 * register is going empty to allow time for the stop bit to transition
+	 * through the transceiver before direction is changed to receive.
+	 *
+	 * Additionally there appears to be a 1 bit clock delay between writing
+	 * to the THR register and transmission of the start bit, per page 8783
+	 * of the AM65 TRM:  https://www.ti.com/lit/ug/spruid7e/spruid7e.pdf
+	 */
+	if (priv->quot) {
+		if (priv->mdr1 == UART_OMAP_MDR1_16X_MODE)
+			baud = port->uartclk / (16 * priv->quot);
+		else
+			baud = port->uartclk / (13 * priv->quot);
+
+		fixed_delay_rts_after_send  = 3 * MSEC_PER_SEC / baud;
+		fixed_delay_rts_before_send = 1 * MSEC_PER_SEC / baud;
+	}
+
+	/*
+	 * Fall back to RS485 software emulation if the UART is missing
+	 * hardware support, if the device tree specifies an mctrl_gpio
+	 * (indicates that RTS is unavailable due to a pinmux conflict)
+	 * or if the requested delays exceed the fixed hardware delays.
+	 */
+	if (!(priv->habit & UART_HAS_NATIVE_RS485) ||
+	    mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS) ||
+	    rs485->delay_rts_after_send  > fixed_delay_rts_after_send ||
+	    rs485->delay_rts_before_send > fixed_delay_rts_before_send) {
+		priv->mdr3 &= ~UART_OMAP_MDR3_DIR_EN;
+		serial_out(up, UART_OMAP_MDR3, priv->mdr3);
+
+		port->rs485_config = serial8250_em485_config;
+		return serial8250_em485_config(port, termios, rs485);
+	}
+
+	rs485->delay_rts_after_send  = fixed_delay_rts_after_send;
+	rs485->delay_rts_before_send = fixed_delay_rts_before_send;
+
+	if (rs485->flags & SER_RS485_ENABLED)
+		priv->mdr3 |= UART_OMAP_MDR3_DIR_EN;
+	else
+		priv->mdr3 &= ~UART_OMAP_MDR3_DIR_EN;
+
+	/*
+	 * Retain same polarity semantics as RS485 software emulation,
+	 * i.e. SER_RS485_RTS_ON_SEND means driving RTS low on send.
+	 */
+	if (rs485->flags & SER_RS485_RTS_ON_SEND)
+		priv->mdr3 &= ~UART_OMAP_MDR3_DIR_POL;
+	else
+		priv->mdr3 |= UART_OMAP_MDR3_DIR_POL;
+
+	serial_out(up, UART_OMAP_MDR3, priv->mdr3);
+
+	return 0;
+}
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static int omap_8250_rx_dma(struct uart_8250_port *p);
+
+/* Must be called while priv->rx_dma_lock is held */
+static void __dma_rx_do_complete(struct uart_8250_port *p)
+{
+	struct uart_8250_dma    *dma = p->dma;
+	struct tty_port         *tty_port = &p->port.state->port;
+	struct omap8250_priv	*priv = p->port.private_data;
+	struct dma_chan		*rxchan = dma->rxchan;
+	dma_cookie_t		cookie;
+	struct dma_tx_state     state;
+	int                     count;
+	int			ret;
+	u32			reg;
+
+	if (!dma->rx_running)
+		goto out;
+
+	cookie = dma->rx_cookie;
+	dma->rx_running = 0;
+
+	/* Re-enable RX FIFO interrupt now that transfer is complete */
+	if (priv->habit & UART_HAS_RHR_IT_DIS) {
+		reg = serial_in(p, UART_OMAP_IER2);
+		reg &= ~UART_OMAP_IER2_RHR_IT_DIS;
+		serial_out(p, UART_OMAP_IER2, reg);
+	}
+
+	dmaengine_tx_status(rxchan, cookie, &state);
+
+	count = dma->rx_size - state.residue + state.in_flight_bytes;
+	if (count < dma->rx_size) {
+		dmaengine_terminate_async(rxchan);
+
+		/*
+		 * Poll for teardown to complete which guarantees in
+		 * flight data is drained.
+		 */
+		if (state.in_flight_bytes) {
+			int poll_count = 25;
+
+			while (dmaengine_tx_status(rxchan, cookie, NULL) &&
+			       poll_count--)
+				cpu_relax();
+
+			if (poll_count == -1)
+				dev_err(p->port.dev, "teardown incomplete\n");
+		}
+	}
+	if (!count)
+		goto out;
+	ret = tty_insert_flip_string(tty_port, dma->rx_buf, count);
+
+	p->port.icount.rx += ret;
+	p->port.icount.buf_overrun += count - ret;
+out:
+
+	tty_flip_buffer_push(tty_port);
+}
+
+static void __dma_rx_complete(void *param)
+{
+	struct uart_8250_port *p = param;
+	struct omap8250_priv *priv = p->port.private_data;
+	struct uart_8250_dma *dma = p->dma;
+	struct dma_tx_state     state;
+	unsigned long flags;
+
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irqsave(&p->port.lock, flags);
+
+	/*
+	 * If the tx status is not DMA_COMPLETE, then this is a delayed
+	 * completion callback. A previous RX timeout flush would have
+	 * already pushed the data, so exit.
+	 */
+	if (dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state) !=
+			DMA_COMPLETE) {
+		spin_unlock_irqrestore(&p->port.lock, flags);
+		return;
+	}
+	__dma_rx_do_complete(p);
+	if (!priv->throttled) {
+		p->ier |= UART_IER_RLSI | UART_IER_RDI;
+		serial_out(p, UART_IER, p->ier);
+		if (!(priv->habit & UART_HAS_EFR2))
+			omap_8250_rx_dma(p);
+	}
+
+	spin_unlock_irqrestore(&p->port.lock, flags);
+}
+
+static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
+{
+	struct omap8250_priv	*priv = p->port.private_data;
+	struct uart_8250_dma	*dma = p->dma;
+	struct dma_tx_state     state;
+	unsigned long		flags;
+	int ret;
+
+	spin_lock_irqsave(&priv->rx_dma_lock, flags);
+
+	if (!dma->rx_running) {
+		spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
+		return;
+	}
+
+	ret = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+	if (ret == DMA_IN_PROGRESS) {
+		ret = dmaengine_pause(dma->rxchan);
+		if (WARN_ON_ONCE(ret))
+			priv->rx_dma_broken = true;
+	}
+	__dma_rx_do_complete(p);
+	spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
+}
+
+static int omap_8250_rx_dma(struct uart_8250_port *p)
+{
+	struct omap8250_priv		*priv = p->port.private_data;
+	struct uart_8250_dma            *dma = p->dma;
+	int				err = 0;
+	struct dma_async_tx_descriptor  *desc;
+	unsigned long			flags;
+	u32				reg;
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&p->port.lock);
+
+	if (priv->rx_dma_broken)
+		return -EINVAL;
+
+	spin_lock_irqsave(&priv->rx_dma_lock, flags);
+
+	if (dma->rx_running) {
+		enum dma_status state;
+
+		state = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, NULL);
+		if (state == DMA_COMPLETE) {
+			/*
+			 * Disable RX interrupts to allow RX DMA completion
+			 * callback to run.
+			 */
+			p->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+			serial_out(p, UART_IER, p->ier);
+		}
+		goto out;
+	}
+
+	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
+					   dma->rx_size, DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	dma->rx_running = 1;
+	desc->callback = __dma_rx_complete;
+	desc->callback_param = p;
+
+	dma->rx_cookie = dmaengine_submit(desc);
+
+	/*
+	 * Disable RX FIFO interrupt while RX DMA is enabled, else
+	 * spurious interrupt may be raised when data is in the RX FIFO
+	 * but is yet to be drained by DMA.
+	 */
+	if (priv->habit & UART_HAS_RHR_IT_DIS) {
+		reg = serial_in(p, UART_OMAP_IER2);
+		reg |= UART_OMAP_IER2_RHR_IT_DIS;
+		serial_out(p, UART_OMAP_IER2, reg);
+	}
+
+	dma_async_issue_pending(dma->rxchan);
+out:
+	spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
+	return err;
+}
+
+static int omap_8250_tx_dma(struct uart_8250_port *p);
+
+static void omap_8250_dma_tx_complete(void *param)
+{
+	struct uart_8250_port	*p = param;
+	struct uart_8250_dma	*dma = p->dma;
+	struct circ_buf		*xmit = &p->port.state->xmit;
+	unsigned long		flags;
+	bool			en_thri = false;
+	struct omap8250_priv	*priv = p->port.private_data;
+
+	dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
+				UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+	spin_lock_irqsave(&p->port.lock, flags);
+
+	dma->tx_running = 0;
+
+	uart_xmit_advance(&p->port, dma->tx_size);
+
+	if (priv->delayed_restore) {
+		priv->delayed_restore = 0;
+		omap8250_restore_regs(p);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&p->port);
+
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port)) {
+		int ret;
+
+		ret = omap_8250_tx_dma(p);
+		if (ret)
+			en_thri = true;
+	} else if (p->capabilities & UART_CAP_RPM) {
+		en_thri = true;
+	}
+
+	if (en_thri) {
+		dma->tx_err = 1;
+		serial8250_set_THRI(p);
+	}
+
+	spin_unlock_irqrestore(&p->port.lock, flags);
+}
+
+static int omap_8250_tx_dma(struct uart_8250_port *p)
+{
+	struct uart_8250_dma		*dma = p->dma;
+	struct omap8250_priv		*priv = p->port.private_data;
+	struct circ_buf			*xmit = &p->port.state->xmit;
+	struct dma_async_tx_descriptor	*desc;
+	unsigned int	skip_byte = 0;
+	int ret;
+
+	if (dma->tx_running)
+		return 0;
+	if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) {
+
+		/*
+		 * Even if no data, we need to return an error for the two cases
+		 * below so serial8250_tx_chars() is invoked and properly clears
+		 * THRI and/or runtime suspend.
+		 */
+		if (dma->tx_err || p->capabilities & UART_CAP_RPM) {
+			ret = -EBUSY;
+			goto err;
+		}
+		serial8250_clear_THRI(p);
+		return 0;
+	}
+
+	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (priv->habit & OMAP_DMA_TX_KICK) {
+		u8 tx_lvl;
+
+		/*
+		 * We need to put the first byte into the FIFO in order to start
+		 * the DMA transfer. For transfers smaller than four bytes we
+		 * don't bother doing DMA at all. It seem not matter if there
+		 * are still bytes in the FIFO from the last transfer (in case
+		 * we got here directly from omap_8250_dma_tx_complete()). Bytes
+		 * leaving the FIFO seem not to trigger the DMA transfer. It is
+		 * really the byte that we put into the FIFO.
+		 * If the FIFO is already full then we most likely got here from
+		 * omap_8250_dma_tx_complete(). And this means the DMA engine
+		 * just completed its work. We don't have to wait the complete
+		 * 86us at 115200,8n1 but around 60us (not to mention lower
+		 * baudrates). So in that case we take the interrupt and try
+		 * again with an empty FIFO.
+		 */
+		tx_lvl = serial_in(p, UART_OMAP_TX_LVL);
+		if (tx_lvl == p->tx_loadsz) {
+			ret = -EBUSY;
+			goto err;
+		}
+		if (dma->tx_size < 4) {
+			ret = -EINVAL;
+			goto err;
+		}
+		skip_byte = 1;
+	}
+
+	desc = dmaengine_prep_slave_single(dma->txchan,
+			dma->tx_addr + xmit->tail + skip_byte,
+			dma->tx_size - skip_byte, DMA_MEM_TO_DEV,
+			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dma->tx_running = 1;
+
+	desc->callback = omap_8250_dma_tx_complete;
+	desc->callback_param = p;
+
+	dma->tx_cookie = dmaengine_submit(desc);
+
+	dma_sync_single_for_device(dma->txchan->device->dev, dma->tx_addr,
+				   UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+	dma_async_issue_pending(dma->txchan);
+	if (dma->tx_err)
+		dma->tx_err = 0;
+
+	serial8250_clear_THRI(p);
+	if (skip_byte)
+		serial_out(p, UART_TX, xmit->buf[xmit->tail]);
+	return 0;
+err:
+	dma->tx_err = 1;
+	return ret;
+}
+
+static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
+{
+	switch (iir & 0x3f) {
+	case UART_IIR_RLSI:
+	case UART_IIR_RX_TIMEOUT:
+	case UART_IIR_RDI:
+		omap_8250_rx_dma_flush(up);
+		return true;
+	}
+	return omap_8250_rx_dma(up);
+}
+
+static u16 omap_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir, u16 status)
+{
+	if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
+	    (iir & UART_IIR_RDI)) {
+		if (handle_rx_dma(up, iir)) {
+			status = serial8250_rx_chars(up, status);
+			omap_8250_rx_dma(up);
+		}
+	}
+
+	return status;
+}
+
+static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir,
+				     u16 status)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	/*
+	 * Queue a new transfer if FIFO has data.
+	 */
+	if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
+	    (up->ier & UART_IER_RDI)) {
+		omap_8250_rx_dma(up);
+		serial_out(up, UART_OMAP_EFR2, UART_OMAP_EFR2_TIMEOUT_BEHAVE);
+	} else if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) {
+		/*
+		 * Disable RX timeout, read IIR to clear
+		 * current timeout condition, clear EFR2 to
+		 * periodic timeouts, re-enable interrupts.
+		 */
+		up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+		serial_out(up, UART_IER, up->ier);
+		omap_8250_rx_dma_flush(up);
+		serial_in(up, UART_IIR);
+		serial_out(up, UART_OMAP_EFR2, 0x0);
+		up->ier |= UART_IER_RLSI | UART_IER_RDI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+/*
+ * This is mostly serial8250_handle_irq(). We have a slightly different DMA
+ * hoook for RX/TX and need different logic for them in the ISR. Therefore we
+ * use the default routine in the non-DMA case and this one for with DMA.
+ */
+static int omap_8250_dma_handle_irq(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = up->port.private_data;
+	u16 status;
+	u8 iir;
+
+	serial8250_rpm_get(up);
+
+	iir = serial_port_in(port, UART_IIR);
+	if (iir & UART_IIR_NO_INT) {
+		serial8250_rpm_put(up);
+		return IRQ_HANDLED;
+	}
+
+	spin_lock(&port->lock);
+
+	status = serial_port_in(port, UART_LSR);
+
+	if ((iir & 0x3f) != UART_IIR_THRI) {
+		if (priv->habit & UART_HAS_EFR2)
+			am654_8250_handle_rx_dma(up, iir, status);
+		else
+			status = omap_8250_handle_rx_dma(up, iir, status);
+	}
+
+	serial8250_modem_status(up);
+	if (status & UART_LSR_THRE && up->dma->tx_err) {
+		if (uart_tx_stopped(&up->port) ||
+		    uart_circ_empty(&up->port.state->xmit)) {
+			up->dma->tx_err = 0;
+			serial8250_tx_chars(up);
+		} else  {
+			/*
+			 * try again due to an earlier failer which
+			 * might have been resolved by now.
+			 */
+			if (omap_8250_tx_dma(up))
+				serial8250_tx_chars(up);
+		}
+	}
+
+	uart_unlock_and_check_sysrq(port);
+
+	serial8250_rpm_put(up);
+	return 1;
+}
+
+static bool the_no_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+	return false;
+}
+
+#else
+
+static inline int omap_8250_rx_dma(struct uart_8250_port *p)
+{
+	return -EINVAL;
+}
+#endif
+
+static int omap8250_no_handle_irq(struct uart_port *port)
+{
+	/* IRQ has not been requested but handling irq? */
+	WARN_ONCE(1, "Unexpected irq handling before port startup\n");
+	return 0;
+}
+
+static struct omap8250_dma_params am654_dma = {
+	.rx_size = SZ_2K,
+	.rx_trigger = 1,
+	.tx_trigger = TX_TRIGGER,
+};
+
+static struct omap8250_dma_params am33xx_dma = {
+	.rx_size = RX_TRIGGER,
+	.rx_trigger = RX_TRIGGER,
+	.tx_trigger = TX_TRIGGER,
+};
+
+static struct omap8250_platdata am654_platdata = {
+	.dma_params	= &am654_dma,
+	.habit		= UART_HAS_EFR2 | UART_HAS_RHR_IT_DIS |
+			  UART_RX_TIMEOUT_QUIRK | UART_HAS_NATIVE_RS485,
+};
+
+static struct omap8250_platdata am33xx_platdata = {
+	.dma_params	= &am33xx_dma,
+	.habit		= OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE,
+};
+
+static struct omap8250_platdata omap4_platdata = {
+	.dma_params	= &am33xx_dma,
+	.habit		= UART_ERRATA_CLOCK_DISABLE,
+};
+
+static const struct of_device_id omap8250_dt_ids[] = {
+	{ .compatible = "ti,am654-uart", .data = &am654_platdata, },
+	{ .compatible = "ti,omap2-uart" },
+	{ .compatible = "ti,omap3-uart" },
+	{ .compatible = "ti,omap4-uart", .data = &omap4_platdata, },
+	{ .compatible = "ti,am3352-uart", .data = &am33xx_platdata, },
+	{ .compatible = "ti,am4372-uart", .data = &am33xx_platdata, },
+	{ .compatible = "ti,dra742-uart", .data = &omap4_platdata, },
+	{},
+};
+MODULE_DEVICE_TABLE(of, omap8250_dt_ids);
+
+static int omap8250_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct omap8250_priv *priv;
+	const struct omap8250_platdata *pdata;
+	struct uart_8250_port up;
+	struct resource *regs;
+	void __iomem *membase;
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "missing registers\n");
+		return -EINVAL;
+	}
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	membase = devm_ioremap(&pdev->dev, regs->start,
+				       resource_size(regs));
+	if (!membase)
+		return -ENODEV;
+
+	memset(&up, 0, sizeof(up));
+	up.port.dev = &pdev->dev;
+	up.port.mapbase = regs->start;
+	up.port.membase = membase;
+	up.port.irq = irq;
+	/*
+	 * It claims to be 16C750 compatible however it is a little different.
+	 * It has EFR and has no FCR7_64byte bit. The AFE (which it claims to
+	 * have) is enabled via EFR instead of MCR. The type is set here 8250
+	 * just to get things going. UNKNOWN does not work for a few reasons and
+	 * we don't need our own type since we don't use 8250's set_termios()
+	 * or pm callback.
+	 */
+	up.port.type = PORT_8250;
+	up.port.iotype = UPIO_MEM;
+	up.port.flags = UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_SOFT_FLOW |
+		UPF_HARD_FLOW;
+	up.port.private_data = priv;
+
+	up.port.regshift = OMAP_UART_REGSHIFT;
+	up.port.fifosize = 64;
+	up.tx_loadsz = 64;
+	up.capabilities = UART_CAP_FIFO;
+#ifdef CONFIG_PM
+	/*
+	 * Runtime PM is mostly transparent. However to do it right we need to a
+	 * TX empty interrupt before we can put the device to auto idle. So if
+	 * PM is not enabled we don't add that flag and can spare that one extra
+	 * interrupt in the TX path.
+	 */
+	up.capabilities |= UART_CAP_RPM;
+#endif
+	up.port.set_termios = omap_8250_set_termios;
+	up.port.set_mctrl = omap8250_set_mctrl;
+	up.port.pm = omap_8250_pm;
+	up.port.startup = omap_8250_startup;
+	up.port.shutdown = omap_8250_shutdown;
+	up.port.throttle = omap_8250_throttle;
+	up.port.unthrottle = omap_8250_unthrottle;
+	up.port.rs485_config = omap8250_rs485_config;
+	/* same rs485_supported for software emulation and native RS485 */
+	up.port.rs485_supported = serial8250_em485_supported;
+	up.rs485_start_tx = serial8250_em485_start_tx;
+	up.rs485_stop_tx = serial8250_em485_stop_tx;
+	up.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias\n");
+		return ret;
+	}
+	up.port.line = ret;
+
+	if (of_property_read_u32(np, "clock-frequency", &up.port.uartclk)) {
+		struct clk *clk;
+
+		clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(clk)) {
+			if (PTR_ERR(clk) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+		} else {
+			up.port.uartclk = clk_get_rate(clk);
+		}
+	}
+
+	if (of_property_read_u32(np, "overrun-throttle-ms",
+				 &up.overrun_backoff_time_ms) != 0)
+		up.overrun_backoff_time_ms = 0;
+
+	pdata = of_device_get_match_data(&pdev->dev);
+	if (pdata)
+		priv->habit |= pdata->habit;
+
+	if (!up.port.uartclk) {
+		up.port.uartclk = DEFAULT_CLK_SPEED;
+		dev_warn(&pdev->dev,
+			 "No clock speed specified: using default: %d\n",
+			 DEFAULT_CLK_SPEED);
+	}
+
+	priv->membase = membase;
+	priv->line = -ENODEV;
+	priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	priv->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	cpu_latency_qos_add_request(&priv->pm_qos_request, priv->latency);
+	INIT_WORK(&priv->qos_work, omap8250_uart_qos_work);
+
+	spin_lock_init(&priv->rx_dma_lock);
+
+	platform_set_drvdata(pdev, priv);
+
+	device_init_wakeup(&pdev->dev, true);
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_use_autosuspend(&pdev->dev);
+
+	/*
+	 * Disable runtime PM until autosuspend delay unless specifically
+	 * enabled by the user via sysfs. This is the historic way to
+	 * prevent an unsafe default policy with lossy characters on wake-up.
+	 * For serdev devices this is not needed, the policy can be managed by
+	 * the serdev driver.
+	 */
+	if (!of_get_available_child_count(pdev->dev.of_node))
+		pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
+
+	pm_runtime_irq_safe(&pdev->dev);
+
+	pm_runtime_get_sync(&pdev->dev);
+
+	omap_serial_fill_features_erratas(&up, priv);
+	up.port.handle_irq = omap8250_no_handle_irq;
+	priv->rx_trigger = RX_TRIGGER;
+	priv->tx_trigger = TX_TRIGGER;
+#ifdef CONFIG_SERIAL_8250_DMA
+	/*
+	 * Oh DMA support. If there are no DMA properties in the DT then
+	 * we will fall back to a generic DMA channel which does not
+	 * really work here. To ensure that we do not get a generic DMA
+	 * channel assigned, we have the the_no_dma_filter_fn() here.
+	 * To avoid "failed to request DMA" messages we check for DMA
+	 * properties in DT.
+	 */
+	ret = of_property_count_strings(np, "dma-names");
+	if (ret == 2) {
+		struct omap8250_dma_params *dma_params = NULL;
+		struct uart_8250_dma *dma = &priv->omap8250_dma;
+
+		dma->fn = the_no_dma_filter_fn;
+		dma->tx_dma = omap_8250_tx_dma;
+		dma->rx_dma = omap_8250_rx_dma;
+		if (pdata)
+			dma_params = pdata->dma_params;
+
+		if (dma_params) {
+			dma->rx_size = dma_params->rx_size;
+			dma->rxconf.src_maxburst = dma_params->rx_trigger;
+			dma->txconf.dst_maxburst = dma_params->tx_trigger;
+			priv->rx_trigger = dma_params->rx_trigger;
+			priv->tx_trigger = dma_params->tx_trigger;
+		} else {
+			dma->rx_size = RX_TRIGGER;
+			dma->rxconf.src_maxburst = RX_TRIGGER;
+			dma->txconf.dst_maxburst = TX_TRIGGER;
+		}
+	}
+#endif
+
+	irq_set_status_flags(irq, IRQ_NOAUTOEN);
+	ret = devm_request_irq(&pdev->dev, irq, omap8250_irq, 0,
+			       dev_name(&pdev->dev), priv);
+	if (ret < 0)
+		return ret;
+
+	priv->wakeirq = irq_of_parse_and_map(np, 1);
+
+	ret = serial8250_register_8250_port(&up);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "unable to register 8250 port\n");
+		goto err;
+	}
+	priv->line = ret;
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+	return 0;
+err:
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
+	flush_work(&priv->qos_work);
+	pm_runtime_disable(&pdev->dev);
+	cpu_latency_qos_remove_request(&priv->pm_qos_request);
+	return ret;
+}
+
+static int omap8250_remove(struct platform_device *pdev)
+{
+	struct omap8250_priv *priv = platform_get_drvdata(pdev);
+	struct uart_8250_port *up;
+	int err;
+
+	err = pm_runtime_resume_and_get(&pdev->dev);
+	if (err)
+		dev_err(&pdev->dev, "Failed to resume hardware\n");
+
+	up = serial8250_get_port(priv->line);
+	omap_8250_shutdown(&up->port);
+	serial8250_unregister_port(priv->line);
+	priv->line = -ENODEV;
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
+	flush_work(&priv->qos_work);
+	pm_runtime_disable(&pdev->dev);
+	cpu_latency_qos_remove_request(&priv->pm_qos_request);
+	device_init_wakeup(&pdev->dev, false);
+	return 0;
+}
+
+static int omap8250_prepare(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+
+	if (!priv)
+		return 0;
+	priv->is_suspending = true;
+	return 0;
+}
+
+static void omap8250_complete(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+
+	if (!priv)
+		return;
+	priv->is_suspending = false;
+}
+
+static int omap8250_suspend(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+	int err = 0;
+
+	serial8250_suspend_port(priv->line);
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err)
+		return err;
+	if (!device_may_wakeup(dev))
+		priv->wer = 0;
+	serial_out(up, UART_OMAP_WER, priv->wer);
+	if (uart_console(&up->port) && console_suspend_enabled)
+		err = pm_runtime_force_suspend(dev);
+	flush_work(&priv->qos_work);
+
+	return err;
+}
+
+static int omap8250_resume(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+	int err;
+
+	if (uart_console(&up->port) && console_suspend_enabled) {
+		err = pm_runtime_force_resume(dev);
+		if (err)
+			return err;
+	}
+
+	serial8250_resume_port(priv->line);
+	/* Paired with pm_runtime_resume_and_get() in omap8250_suspend() */
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
+}
+
+static int omap8250_lost_context(struct uart_8250_port *up)
+{
+	u32 val;
+
+	val = serial_in(up, UART_OMAP_SCR);
+	/*
+	 * If we lose context, then SCR is set to its reset value of zero.
+	 * After set_termios() we set bit 3 of SCR (TX_EMPTY_CTL_IT) to 1,
+	 * among other bits, to never set the register back to zero again.
+	 */
+	if (!val)
+		return 1;
+	return 0;
+}
+
+static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val)
+{
+	writel(val, priv->membase + (reg << OMAP_UART_REGSHIFT));
+}
+
+/* TODO: in future, this should happen via API in drivers/reset/ */
+static int omap8250_soft_reset(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+	int timeout = 100;
+	int sysc;
+	int syss;
+
+	/*
+	 * At least on omap4, unused uarts may not idle after reset without
+	 * a basic scr dma configuration even with no dma in use. The
+	 * module clkctrl status bits will be 1 instead of 3 blocking idle
+	 * for the whole clockdomain. The softreset below will clear scr,
+	 * and we restore it on resume so this is safe to do on all SoCs
+	 * needing omap8250_soft_reset() quirk. Do it in two writes as
+	 * recommended in the comment for omap8250_update_scr().
+	 */
+	uart_write(priv, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1);
+	uart_write(priv, UART_OMAP_SCR,
+		   OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL);
+
+	sysc = uart_read(priv, UART_OMAP_SYSC);
+
+	/* softreset the UART */
+	sysc |= OMAP_UART_SYSC_SOFTRESET;
+	uart_write(priv, UART_OMAP_SYSC, sysc);
+
+	/* By experiments, 1us enough for reset complete on AM335x */
+	do {
+		udelay(1);
+		syss = uart_read(priv, UART_OMAP_SYSS);
+	} while (--timeout && !(syss & OMAP_UART_SYSS_RESETDONE));
+
+	if (!timeout) {
+		dev_err(dev, "timed out waiting for reset done\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int omap8250_runtime_suspend(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = NULL;
+
+	if (priv->line >= 0)
+		up = serial8250_get_port(priv->line);
+
+	if (priv->habit & UART_ERRATA_CLOCK_DISABLE) {
+		int ret;
+
+		ret = omap8250_soft_reset(dev);
+		if (ret)
+			return ret;
+
+		if (up) {
+			/* Restore to UART mode after reset (for wakeup) */
+			omap8250_update_mdr1(up, priv);
+			/* Restore wakeup enable register */
+			serial_out(up, UART_OMAP_WER, priv->wer);
+		}
+	}
+
+	if (up && up->dma && up->dma->rxchan)
+		omap_8250_rx_dma_flush(up);
+
+	priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	schedule_work(&priv->qos_work);
+
+	return 0;
+}
+
+static int omap8250_runtime_resume(struct device *dev)
+{
+	struct omap8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = NULL;
+
+	if (priv->line >= 0)
+		up = serial8250_get_port(priv->line);
+
+	if (up && omap8250_lost_context(up)) {
+		spin_lock_irq(&up->port.lock);
+		omap8250_restore_regs(up);
+		spin_unlock_irq(&up->port.lock);
+	}
+
+	if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) {
+		spin_lock_irq(&up->port.lock);
+		omap_8250_rx_dma(up);
+		spin_unlock_irq(&up->port.lock);
+	}
+
+	priv->latency = priv->calc_latency;
+	schedule_work(&priv->qos_work);
+	return 0;
+}
+
+#ifdef CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP
+static int __init omap8250_console_fixup(void)
+{
+	char *omap_str;
+	char *options;
+	u8 idx;
+
+	if (strstr(boot_command_line, "console=ttyS"))
+		/* user set a ttyS based name for the console */
+		return 0;
+
+	omap_str = strstr(boot_command_line, "console=ttyO");
+	if (!omap_str)
+		/* user did not set ttyO based console, so we don't care */
+		return 0;
+
+	omap_str += 12;
+	if ('0' <= *omap_str && *omap_str <= '9')
+		idx = *omap_str - '0';
+	else
+		return 0;
+
+	omap_str++;
+	if (omap_str[0] == ',') {
+		omap_str++;
+		options = omap_str;
+	} else {
+		options = NULL;
+	}
+
+	add_preferred_console("ttyS", idx, options);
+	pr_err("WARNING: Your 'console=ttyO%d' has been replaced by 'ttyS%d'\n",
+	       idx, idx);
+	pr_err("This ensures that you still see kernel messages. Please\n");
+	pr_err("update your kernel commandline.\n");
+	return 0;
+}
+console_initcall(omap8250_console_fixup);
+#endif
+
+static const struct dev_pm_ops omap8250_dev_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume)
+	RUNTIME_PM_OPS(omap8250_runtime_suspend,
+			   omap8250_runtime_resume, NULL)
+	.prepare        = pm_sleep_ptr(omap8250_prepare),
+	.complete       = pm_sleep_ptr(omap8250_complete),
+};
+
+static struct platform_driver omap8250_platform_driver = {
+	.driver = {
+		.name		= "omap8250",
+		.pm		= pm_ptr(&omap8250_dev_pm_ops),
+		.of_match_table = omap8250_dt_ids,
+	},
+	.probe			= omap8250_probe,
+	.remove			= omap8250_remove,
+};
+module_platform_driver(omap8250_platform_driver);
+
+MODULE_AUTHOR("Sebastian Andrzej Siewior");
+MODULE_DESCRIPTION("OMAP 8250 Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/8250/8250_parisc.c b/drivers/tty/serial/8250/8250_parisc.c
new file mode 100644
index 000000000..948d0a1c6
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_parisc.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	Serial Device Initialisation for Lasi/Asp/Wax/Dino
+ *
+ *	(c) Copyright Matthew Wilcox <willy@debian.org> 2001-2002
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/signal.h>
+#include <linux/types.h>
+
+#include <asm/hardware.h>
+#include <asm/parisc-device.h>
+#include <asm/io.h>
+
+#include "8250.h"
+
+static int __init serial_init_chip(struct parisc_device *dev)
+{
+	struct uart_8250_port uart;
+	unsigned long address;
+	int err;
+
+#if defined(CONFIG_64BIT) && defined(CONFIG_IOSAPIC)
+	if (!dev->irq && (dev->id.sversion == 0xad))
+		dev->irq = iosapic_serial_irq(dev);
+#endif
+
+	if (!dev->irq) {
+		/* We find some unattached serial ports by walking native
+		 * busses.  These should be silently ignored.  Otherwise,
+		 * what we have here is a missing parent device, so tell
+		 * the user what they're missing.
+		 */
+		if (parisc_parent(dev)->id.hw_type != HPHW_IOA)
+			dev_info(&dev->dev,
+				"Serial: device 0x%llx not configured.\n"
+				"Enable support for Wax, Lasi, Asp or Dino.\n",
+				(unsigned long long)dev->hpa.start);
+		return -ENODEV;
+	}
+
+	address = dev->hpa.start;
+	if (dev->id.sversion != 0x8d)
+		address += 0x800;
+
+	memset(&uart, 0, sizeof(uart));
+	uart.port.iotype	= UPIO_MEM;
+	/* 7.272727MHz on Lasi.  Assumed the same for Dino, Wax and Timi. */
+	uart.port.uartclk	= (dev->id.sversion != 0xad) ?
+					7272727 : 1843200;
+	uart.port.mapbase	= address;
+	uart.port.membase	= ioremap(address, 16);
+	if (!uart.port.membase) {
+		dev_warn(&dev->dev, "Failed to map memory\n");
+		return -ENOMEM;
+	}
+	uart.port.irq	= dev->irq;
+	uart.port.flags	= UPF_BOOT_AUTOCONF;
+	uart.port.dev	= &dev->dev;
+
+	err = serial8250_register_8250_port(&uart);
+	if (err < 0) {
+		dev_warn(&dev->dev,
+			"serial8250_register_8250_port returned error %d\n",
+			err);
+		iounmap(uart.port.membase);
+		return err;
+	}
+
+	return 0;
+}
+
+static const struct parisc_device_id serial_tbl[] __initconst = {
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00075 },
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008c },
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008d },
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x000ad },
+	{ 0 }
+};
+
+/* Hack.  Some machines have SERIAL_0 attached to Lasi and SERIAL_1
+ * attached to Dino.  Unfortunately, Dino appears before Lasi in the device
+ * tree.  To ensure that ttyS0 == SERIAL_0, we register two drivers; one
+ * which only knows about Lasi and then a second which will find all the
+ * other serial ports.  HPUX ignores this problem.
+ */
+static const struct parisc_device_id lasi_tbl[] __initconst = {
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x03B, 0x0008C }, /* C1xx/C1xxL */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x03C, 0x0008C }, /* B132L */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x03D, 0x0008C }, /* B160L */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x03E, 0x0008C }, /* B132L+ */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x03F, 0x0008C }, /* B180L+ */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x046, 0x0008C }, /* Rocky2 120 */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x047, 0x0008C }, /* Rocky2 150 */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x04E, 0x0008C }, /* Kiji L2 132 */
+	{ HPHW_FIO, HVERSION_REV_ANY_ID, 0x056, 0x0008C }, /* Raven+ */
+	{ 0 }
+};
+
+
+MODULE_DEVICE_TABLE(parisc, serial_tbl);
+
+static struct parisc_driver lasi_driver __refdata = {
+	.name		= "serial_1",
+	.id_table	= lasi_tbl,
+	.probe		= serial_init_chip,
+};
+
+static struct parisc_driver serial_driver __refdata = {
+	.name		= "serial",
+	.id_table	= serial_tbl,
+	.probe		= serial_init_chip,
+};
+
+static int __init probe_serial_gsc(void)
+{
+	register_parisc_driver(&lasi_driver);
+	register_parisc_driver(&serial_driver);
+	return 0;
+}
+
+module_init(probe_serial_gsc);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
new file mode 100644
index 000000000..bbd7914dd
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -0,0 +1,6049 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Probe module for 8250/16550-type PCI serial ports.
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright (C) 2001 Russell King, All Rights Reserved.
+ */
+#undef DEBUG
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/math.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/tty.h>
+#include <linux/serial_reg.h>
+#include <linux/serial_core.h>
+#include <linux/8250_pci.h>
+#include <linux/bitops.h>
+
+#include <asm/byteorder.h>
+#include <asm/io.h>
+
+#include "8250.h"
+#include "8250_pcilib.h"
+
+/*
+ * init function returns:
+ *  > 0 - number of ports
+ *  = 0 - use board->num_ports
+ *  < 0 - error
+ */
+struct pci_serial_quirk {
+	u32	vendor;
+	u32	device;
+	u32	subvendor;
+	u32	subdevice;
+	int	(*probe)(struct pci_dev *dev);
+	int	(*init)(struct pci_dev *dev);
+	int	(*setup)(struct serial_private *,
+			 const struct pciserial_board *,
+			 struct uart_8250_port *, int);
+	void	(*exit)(struct pci_dev *dev);
+};
+
+struct f815xxa_data {
+	spinlock_t lock;
+	int idx;
+};
+
+struct serial_private {
+	struct pci_dev		*dev;
+	unsigned int		nr;
+	struct pci_serial_quirk	*quirk;
+	const struct pciserial_board *board;
+	int			line[];
+};
+
+#define PCI_DEVICE_ID_HPE_PCI_SERIAL	0x37e
+
+static const struct pci_device_id pci_use_msi[] = {
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9900,
+			 0xA000, 0x1000) },
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9912,
+			 0xA000, 0x1000) },
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9922,
+			 0xA000, 0x1000) },
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_ASIX, PCI_DEVICE_ID_ASIX_AX99100,
+			 0xA000, 0x1000) },
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP_3PAR, PCI_DEVICE_ID_HPE_PCI_SERIAL,
+			 PCI_ANY_ID, PCI_ANY_ID) },
+	{ }
+};
+
+static int pci_default_setup(struct serial_private*,
+	  const struct pciserial_board*, struct uart_8250_port *, int);
+
+static void moan_device(const char *str, struct pci_dev *dev)
+{
+	pci_err(dev, "%s\n"
+	       "Please send the output of lspci -vv, this\n"
+	       "message (0x%04x,0x%04x,0x%04x,0x%04x), the\n"
+	       "manufacturer and name of serial board or\n"
+	       "modem board to <linux-serial@vger.kernel.org>.\n",
+	       str, dev->vendor, dev->device,
+	       dev->subsystem_vendor, dev->subsystem_device);
+}
+
+static int
+setup_port(struct serial_private *priv, struct uart_8250_port *port,
+	   u8 bar, unsigned int offset, int regshift)
+{
+	return serial8250_pci_setup_port(priv->dev, port, bar, offset, regshift);
+}
+
+/*
+ * ADDI-DATA GmbH communication cards <info@addi-data.com>
+ */
+static int addidata_apci7800_setup(struct serial_private *priv,
+				const struct pciserial_board *board,
+				struct uart_8250_port *port, int idx)
+{
+	unsigned int bar = 0, offset = board->first_offset;
+	bar = FL_GET_BASE(board->flags);
+
+	if (idx < 2) {
+		offset += idx * board->uart_offset;
+	} else if ((idx >= 2) && (idx < 4)) {
+		bar += 1;
+		offset += ((idx - 2) * board->uart_offset);
+	} else if ((idx >= 4) && (idx < 6)) {
+		bar += 2;
+		offset += ((idx - 4) * board->uart_offset);
+	} else if (idx >= 6) {
+		bar += 3;
+		offset += ((idx - 6) * board->uart_offset);
+	}
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+/*
+ * AFAVLAB uses a different mixture of BARs and offsets
+ * Not that ugly ;) -- HW
+ */
+static int
+afavlab_setup(struct serial_private *priv, const struct pciserial_board *board,
+	      struct uart_8250_port *port, int idx)
+{
+	unsigned int bar, offset = board->first_offset;
+
+	bar = FL_GET_BASE(board->flags);
+	if (idx < 4)
+		bar += idx;
+	else {
+		bar = 4;
+		offset += (idx - 4) * board->uart_offset;
+	}
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+/*
+ * HP's Remote Management Console.  The Diva chip came in several
+ * different versions.  N-class, L2000 and A500 have two Diva chips, each
+ * with 3 UARTs (the third UART on the second chip is unused).  Superdome
+ * and Keystone have one Diva chip with 3 UARTs.  Some later machines have
+ * one Diva chip, but it has been expanded to 5 UARTs.
+ */
+static int pci_hp_diva_init(struct pci_dev *dev)
+{
+	int rc = 0;
+
+	switch (dev->subsystem_device) {
+	case PCI_DEVICE_ID_HP_DIVA_TOSCA1:
+	case PCI_DEVICE_ID_HP_DIVA_HALFDOME:
+	case PCI_DEVICE_ID_HP_DIVA_KEYSTONE:
+	case PCI_DEVICE_ID_HP_DIVA_EVEREST:
+		rc = 3;
+		break;
+	case PCI_DEVICE_ID_HP_DIVA_TOSCA2:
+		rc = 2;
+		break;
+	case PCI_DEVICE_ID_HP_DIVA_MAESTRO:
+		rc = 4;
+		break;
+	case PCI_DEVICE_ID_HP_DIVA_POWERBAR:
+	case PCI_DEVICE_ID_HP_DIVA_HURRICANE:
+		rc = 1;
+		break;
+	}
+
+	return rc;
+}
+
+/*
+ * HP's Diva chip puts the 4th/5th serial port further out, and
+ * some serial ports are supposed to be hidden on certain models.
+ */
+static int
+pci_hp_diva_setup(struct serial_private *priv,
+		const struct pciserial_board *board,
+		struct uart_8250_port *port, int idx)
+{
+	unsigned int offset = board->first_offset;
+	unsigned int bar = FL_GET_BASE(board->flags);
+
+	switch (priv->dev->subsystem_device) {
+	case PCI_DEVICE_ID_HP_DIVA_MAESTRO:
+		if (idx == 3)
+			idx++;
+		break;
+	case PCI_DEVICE_ID_HP_DIVA_EVEREST:
+		if (idx > 0)
+			idx++;
+		if (idx > 2)
+			idx++;
+		break;
+	}
+	if (idx > 2)
+		offset = 0x18;
+
+	offset += idx * board->uart_offset;
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+/*
+ * Added for EKF Intel i960 serial boards
+ */
+static int pci_inteli960ni_init(struct pci_dev *dev)
+{
+	u32 oldval;
+
+	if (!(dev->subsystem_device & 0x1000))
+		return -ENODEV;
+
+	/* is firmware started? */
+	pci_read_config_dword(dev, 0x44, &oldval);
+	if (oldval == 0x00001000L) { /* RESET value */
+		pci_dbg(dev, "Local i960 firmware missing\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+/*
+ * Some PCI serial cards using the PLX 9050 PCI interface chip require
+ * that the card interrupt be explicitly enabled or disabled.  This
+ * seems to be mainly needed on card using the PLX which also use I/O
+ * mapped memory.
+ */
+static int pci_plx9050_init(struct pci_dev *dev)
+{
+	u8 irq_config;
+	void __iomem *p;
+
+	if ((pci_resource_flags(dev, 0) & IORESOURCE_MEM) == 0) {
+		moan_device("no memory in bar 0", dev);
+		return 0;
+	}
+
+	irq_config = 0x41;
+	if (dev->vendor == PCI_VENDOR_ID_PANACOM ||
+	    dev->subsystem_vendor == PCI_SUBVENDOR_ID_EXSYS)
+		irq_config = 0x43;
+
+	if ((dev->vendor == PCI_VENDOR_ID_PLX) &&
+	    (dev->device == PCI_DEVICE_ID_PLX_ROMULUS))
+		/*
+		 * As the megawolf cards have the int pins active
+		 * high, and have 2 UART chips, both ints must be
+		 * enabled on the 9050. Also, the UARTS are set in
+		 * 16450 mode by default, so we have to enable the
+		 * 16C950 'enhanced' mode so that we can use the
+		 * deep FIFOs
+		 */
+		irq_config = 0x5b;
+	/*
+	 * enable/disable interrupts
+	 */
+	p = ioremap(pci_resource_start(dev, 0), 0x80);
+	if (p == NULL)
+		return -ENOMEM;
+	writel(irq_config, p + 0x4c);
+
+	/*
+	 * Read the register back to ensure that it took effect.
+	 */
+	readl(p + 0x4c);
+	iounmap(p);
+
+	return 0;
+}
+
+static void pci_plx9050_exit(struct pci_dev *dev)
+{
+	u8 __iomem *p;
+
+	if ((pci_resource_flags(dev, 0) & IORESOURCE_MEM) == 0)
+		return;
+
+	/*
+	 * disable interrupts
+	 */
+	p = ioremap(pci_resource_start(dev, 0), 0x80);
+	if (p != NULL) {
+		writel(0, p + 0x4c);
+
+		/*
+		 * Read the register back to ensure that it took effect.
+		 */
+		readl(p + 0x4c);
+		iounmap(p);
+	}
+}
+
+#define NI8420_INT_ENABLE_REG	0x38
+#define NI8420_INT_ENABLE_BIT	0x2000
+
+static void pci_ni8420_exit(struct pci_dev *dev)
+{
+	void __iomem *p;
+	unsigned int bar = 0;
+
+	if ((pci_resource_flags(dev, bar) & IORESOURCE_MEM) == 0) {
+		moan_device("no memory in bar", dev);
+		return;
+	}
+
+	p = pci_ioremap_bar(dev, bar);
+	if (p == NULL)
+		return;
+
+	/* Disable the CPU Interrupt */
+	writel(readl(p + NI8420_INT_ENABLE_REG) & ~(NI8420_INT_ENABLE_BIT),
+	       p + NI8420_INT_ENABLE_REG);
+	iounmap(p);
+}
+
+
+/* MITE registers */
+#define MITE_IOWBSR1	0xc4
+#define MITE_IOWCR1	0xf4
+#define MITE_LCIMR1	0x08
+#define MITE_LCIMR2	0x10
+
+#define MITE_LCIMR2_CLR_CPU_IE	(1 << 30)
+
+static void pci_ni8430_exit(struct pci_dev *dev)
+{
+	void __iomem *p;
+	unsigned int bar = 0;
+
+	if ((pci_resource_flags(dev, bar) & IORESOURCE_MEM) == 0) {
+		moan_device("no memory in bar", dev);
+		return;
+	}
+
+	p = pci_ioremap_bar(dev, bar);
+	if (p == NULL)
+		return;
+
+	/* Disable the CPU Interrupt */
+	writel(MITE_LCIMR2_CLR_CPU_IE, p + MITE_LCIMR2);
+	iounmap(p);
+}
+
+/* SBS Technologies Inc. PMC-OCTPRO and P-OCTAL cards */
+static int
+sbs_setup(struct serial_private *priv, const struct pciserial_board *board,
+		struct uart_8250_port *port, int idx)
+{
+	unsigned int bar, offset = board->first_offset;
+
+	bar = 0;
+
+	if (idx < 4) {
+		/* first four channels map to 0, 0x100, 0x200, 0x300 */
+		offset += idx * board->uart_offset;
+	} else if (idx < 8) {
+		/* last four channels map to 0x1000, 0x1100, 0x1200, 0x1300 */
+		offset += idx * board->uart_offset + 0xC00;
+	} else /* we have only 8 ports on PMC-OCTALPRO */
+		return 1;
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+/*
+* This does initialization for PMC OCTALPRO cards:
+* maps the device memory, resets the UARTs (needed, bc
+* if the module is removed and inserted again, the card
+* is in the sleep mode) and enables global interrupt.
+*/
+
+/* global control register offset for SBS PMC-OctalPro */
+#define OCT_REG_CR_OFF		0x500
+
+static int sbs_init(struct pci_dev *dev)
+{
+	u8 __iomem *p;
+
+	p = pci_ioremap_bar(dev, 0);
+
+	if (p == NULL)
+		return -ENOMEM;
+	/* Set bit-4 Control Register (UART RESET) in to reset the uarts */
+	writeb(0x10, p + OCT_REG_CR_OFF);
+	udelay(50);
+	writeb(0x0, p + OCT_REG_CR_OFF);
+
+	/* Set bit-2 (INTENABLE) of Control Register */
+	writeb(0x4, p + OCT_REG_CR_OFF);
+	iounmap(p);
+
+	return 0;
+}
+
+/*
+ * Disables the global interrupt of PMC-OctalPro
+ */
+
+static void sbs_exit(struct pci_dev *dev)
+{
+	u8 __iomem *p;
+
+	p = pci_ioremap_bar(dev, 0);
+	/* FIXME: What if resource_len < OCT_REG_CR_OFF */
+	if (p != NULL)
+		writeb(0, p + OCT_REG_CR_OFF);
+	iounmap(p);
+}
+
+/*
+ * SIIG serial cards have an PCI interface chip which also controls
+ * the UART clocking frequency. Each UART can be clocked independently
+ * (except cards equipped with 4 UARTs) and initial clocking settings
+ * are stored in the EEPROM chip. It can cause problems because this
+ * version of serial driver doesn't support differently clocked UART's
+ * on single PCI card. To prevent this, initialization functions set
+ * high frequency clocking for all UART's on given card. It is safe (I
+ * hope) because it doesn't touch EEPROM settings to prevent conflicts
+ * with other OSes (like M$ DOS).
+ *
+ *  SIIG support added by Andrey Panin <pazke@donpac.ru>, 10/1999
+ *
+ * There is two family of SIIG serial cards with different PCI
+ * interface chip and different configuration methods:
+ *     - 10x cards have control registers in IO and/or memory space;
+ *     - 20x cards have control registers in standard PCI configuration space.
+ *
+ * Note: all 10x cards have PCI device ids 0x10..
+ *       all 20x cards have PCI device ids 0x20..
+ *
+ * There are also Quartet Serial cards which use Oxford Semiconductor
+ * 16954 quad UART PCI chip clocked by 18.432 MHz quartz.
+ *
+ * Note: some SIIG cards are probed by the parport_serial object.
+ */
+
+#define PCI_DEVICE_ID_SIIG_1S_10x (PCI_DEVICE_ID_SIIG_1S_10x_550 & 0xfffc)
+#define PCI_DEVICE_ID_SIIG_2S_10x (PCI_DEVICE_ID_SIIG_2S_10x_550 & 0xfff8)
+
+static int pci_siig10x_init(struct pci_dev *dev)
+{
+	u16 data;
+	void __iomem *p;
+
+	switch (dev->device & 0xfff8) {
+	case PCI_DEVICE_ID_SIIG_1S_10x:	/* 1S */
+		data = 0xffdf;
+		break;
+	case PCI_DEVICE_ID_SIIG_2S_10x:	/* 2S, 2S1P */
+		data = 0xf7ff;
+		break;
+	default:			/* 1S1P, 4S */
+		data = 0xfffb;
+		break;
+	}
+
+	p = ioremap(pci_resource_start(dev, 0), 0x80);
+	if (p == NULL)
+		return -ENOMEM;
+
+	writew(readw(p + 0x28) & data, p + 0x28);
+	readw(p + 0x28);
+	iounmap(p);
+	return 0;
+}
+
+#define PCI_DEVICE_ID_SIIG_2S_20x (PCI_DEVICE_ID_SIIG_2S_20x_550 & 0xfffc)
+#define PCI_DEVICE_ID_SIIG_2S1P_20x (PCI_DEVICE_ID_SIIG_2S1P_20x_550 & 0xfffc)
+
+static int pci_siig20x_init(struct pci_dev *dev)
+{
+	u8 data;
+
+	/* Change clock frequency for the first UART. */
+	pci_read_config_byte(dev, 0x6f, &data);
+	pci_write_config_byte(dev, 0x6f, data & 0xef);
+
+	/* If this card has 2 UART, we have to do the same with second UART. */
+	if (((dev->device & 0xfffc) == PCI_DEVICE_ID_SIIG_2S_20x) ||
+	    ((dev->device & 0xfffc) == PCI_DEVICE_ID_SIIG_2S1P_20x)) {
+		pci_read_config_byte(dev, 0x73, &data);
+		pci_write_config_byte(dev, 0x73, data & 0xef);
+	}
+	return 0;
+}
+
+static int pci_siig_init(struct pci_dev *dev)
+{
+	unsigned int type = dev->device & 0xff00;
+
+	if (type == 0x1000)
+		return pci_siig10x_init(dev);
+	if (type == 0x2000)
+		return pci_siig20x_init(dev);
+
+	moan_device("Unknown SIIG card", dev);
+	return -ENODEV;
+}
+
+static int pci_siig_setup(struct serial_private *priv,
+			  const struct pciserial_board *board,
+			  struct uart_8250_port *port, int idx)
+{
+	unsigned int bar = FL_GET_BASE(board->flags) + idx, offset = 0;
+
+	if (idx > 3) {
+		bar = 4;
+		offset = (idx - 4) * 8;
+	}
+
+	return setup_port(priv, port, bar, offset, 0);
+}
+
+/*
+ * Timedia has an explosion of boards, and to avoid the PCI table from
+ * growing *huge*, we use this function to collapse some 70 entries
+ * in the PCI table into one, for sanity's and compactness's sake.
+ */
+static const unsigned short timedia_single_port[] = {
+	0x4025, 0x4027, 0x4028, 0x5025, 0x5027, 0
+};
+
+static const unsigned short timedia_dual_port[] = {
+	0x0002, 0x4036, 0x4037, 0x4038, 0x4078, 0x4079, 0x4085,
+	0x4088, 0x4089, 0x5037, 0x5078, 0x5079, 0x5085, 0x6079,
+	0x7079, 0x8079, 0x8137, 0x8138, 0x8237, 0x8238, 0x9079,
+	0x9137, 0x9138, 0x9237, 0x9238, 0xA079, 0xB079, 0xC079,
+	0xD079, 0
+};
+
+static const unsigned short timedia_quad_port[] = {
+	0x4055, 0x4056, 0x4095, 0x4096, 0x5056, 0x8156, 0x8157,
+	0x8256, 0x8257, 0x9056, 0x9156, 0x9157, 0x9158, 0x9159,
+	0x9256, 0x9257, 0xA056, 0xA157, 0xA158, 0xA159, 0xB056,
+	0xB157, 0
+};
+
+static const unsigned short timedia_eight_port[] = {
+	0x4065, 0x4066, 0x5065, 0x5066, 0x8166, 0x9066, 0x9166,
+	0x9167, 0x9168, 0xA066, 0xA167, 0xA168, 0
+};
+
+static const struct timedia_struct {
+	int num;
+	const unsigned short *ids;
+} timedia_data[] = {
+	{ 1, timedia_single_port },
+	{ 2, timedia_dual_port },
+	{ 4, timedia_quad_port },
+	{ 8, timedia_eight_port }
+};
+
+/*
+ * There are nearly 70 different Timedia/SUNIX PCI serial devices.  Instead of
+ * listing them individually, this driver merely grabs them all with
+ * PCI_ANY_ID.  Some of these devices, however, also feature a parallel port,
+ * and should be left free to be claimed by parport_serial instead.
+ */
+static int pci_timedia_probe(struct pci_dev *dev)
+{
+	/*
+	 * Check the third digit of the subdevice ID
+	 * (0,2,3,5,6: serial only -- 7,8,9: serial + parallel)
+	 */
+	if ((dev->subsystem_device & 0x00f0) >= 0x70) {
+		pci_info(dev, "ignoring Timedia subdevice %04x for parport_serial\n",
+			 dev->subsystem_device);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int pci_timedia_init(struct pci_dev *dev)
+{
+	const unsigned short *ids;
+	int i, j;
+
+	for (i = 0; i < ARRAY_SIZE(timedia_data); i++) {
+		ids = timedia_data[i].ids;
+		for (j = 0; ids[j]; j++)
+			if (dev->subsystem_device == ids[j])
+				return timedia_data[i].num;
+	}
+	return 0;
+}
+
+/*
+ * Timedia/SUNIX uses a mixture of BARs and offsets
+ * Ugh, this is ugly as all hell --- TYT
+ */
+static int
+pci_timedia_setup(struct serial_private *priv,
+		  const struct pciserial_board *board,
+		  struct uart_8250_port *port, int idx)
+{
+	unsigned int bar = 0, offset = board->first_offset;
+
+	switch (idx) {
+	case 0:
+		bar = 0;
+		break;
+	case 1:
+		offset = board->uart_offset;
+		bar = 0;
+		break;
+	case 2:
+		bar = 1;
+		break;
+	case 3:
+		offset = board->uart_offset;
+		fallthrough;
+	case 4: /* BAR 2 */
+	case 5: /* BAR 3 */
+	case 6: /* BAR 4 */
+	case 7: /* BAR 5 */
+		bar = idx - 2;
+	}
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+/*
+ * Some Titan cards are also a little weird
+ */
+static int
+titan_400l_800l_setup(struct serial_private *priv,
+		      const struct pciserial_board *board,
+		      struct uart_8250_port *port, int idx)
+{
+	unsigned int bar, offset = board->first_offset;
+
+	switch (idx) {
+	case 0:
+		bar = 1;
+		break;
+	case 1:
+		bar = 2;
+		break;
+	default:
+		bar = 4;
+		offset = (idx - 2) * board->uart_offset;
+	}
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+static int pci_xircom_init(struct pci_dev *dev)
+{
+	msleep(100);
+	return 0;
+}
+
+static int pci_ni8420_init(struct pci_dev *dev)
+{
+	void __iomem *p;
+	unsigned int bar = 0;
+
+	if ((pci_resource_flags(dev, bar) & IORESOURCE_MEM) == 0) {
+		moan_device("no memory in bar", dev);
+		return 0;
+	}
+
+	p = pci_ioremap_bar(dev, bar);
+	if (p == NULL)
+		return -ENOMEM;
+
+	/* Enable CPU Interrupt */
+	writel(readl(p + NI8420_INT_ENABLE_REG) | NI8420_INT_ENABLE_BIT,
+	       p + NI8420_INT_ENABLE_REG);
+
+	iounmap(p);
+	return 0;
+}
+
+#define MITE_IOWBSR1_WSIZE	0xa
+#define MITE_IOWBSR1_WIN_OFFSET	0x800
+#define MITE_IOWBSR1_WENAB	(1 << 7)
+#define MITE_LCIMR1_IO_IE_0	(1 << 24)
+#define MITE_LCIMR2_SET_CPU_IE	(1 << 31)
+#define MITE_IOWCR1_RAMSEL_MASK	0xfffffffe
+
+static int pci_ni8430_init(struct pci_dev *dev)
+{
+	void __iomem *p;
+	struct pci_bus_region region;
+	u32 device_window;
+	unsigned int bar = 0;
+
+	if ((pci_resource_flags(dev, bar) & IORESOURCE_MEM) == 0) {
+		moan_device("no memory in bar", dev);
+		return 0;
+	}
+
+	p = pci_ioremap_bar(dev, bar);
+	if (p == NULL)
+		return -ENOMEM;
+
+	/*
+	 * Set device window address and size in BAR0, while acknowledging that
+	 * the resource structure may contain a translated address that differs
+	 * from the address the device responds to.
+	 */
+	pcibios_resource_to_bus(dev->bus, &region, &dev->resource[bar]);
+	device_window = ((region.start + MITE_IOWBSR1_WIN_OFFSET) & 0xffffff00)
+			| MITE_IOWBSR1_WENAB | MITE_IOWBSR1_WSIZE;
+	writel(device_window, p + MITE_IOWBSR1);
+
+	/* Set window access to go to RAMSEL IO address space */
+	writel((readl(p + MITE_IOWCR1) & MITE_IOWCR1_RAMSEL_MASK),
+	       p + MITE_IOWCR1);
+
+	/* Enable IO Bus Interrupt 0 */
+	writel(MITE_LCIMR1_IO_IE_0, p + MITE_LCIMR1);
+
+	/* Enable CPU Interrupt */
+	writel(MITE_LCIMR2_SET_CPU_IE, p + MITE_LCIMR2);
+
+	iounmap(p);
+	return 0;
+}
+
+/* UART Port Control Register */
+#define NI8430_PORTCON	0x0f
+#define NI8430_PORTCON_TXVR_ENABLE	(1 << 3)
+
+static int
+pci_ni8430_setup(struct serial_private *priv,
+		 const struct pciserial_board *board,
+		 struct uart_8250_port *port, int idx)
+{
+	struct pci_dev *dev = priv->dev;
+	void __iomem *p;
+	unsigned int bar, offset = board->first_offset;
+
+	if (idx >= board->num_ports)
+		return 1;
+
+	bar = FL_GET_BASE(board->flags);
+	offset += idx * board->uart_offset;
+
+	p = pci_ioremap_bar(dev, bar);
+	if (!p)
+		return -ENOMEM;
+
+	/* enable the transceiver */
+	writeb(readb(p + offset + NI8430_PORTCON) | NI8430_PORTCON_TXVR_ENABLE,
+	       p + offset + NI8430_PORTCON);
+
+	iounmap(p);
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+static int pci_netmos_9900_setup(struct serial_private *priv,
+				const struct pciserial_board *board,
+				struct uart_8250_port *port, int idx)
+{
+	unsigned int bar;
+
+	if ((priv->dev->device != PCI_DEVICE_ID_NETMOS_9865) &&
+	    (priv->dev->subsystem_device & 0xff00) == 0x3000) {
+		/* netmos apparently orders BARs by datasheet layout, so serial
+		 * ports get BARs 0 and 3 (or 1 and 4 for memmapped)
+		 */
+		bar = 3 * idx;
+
+		return setup_port(priv, port, bar, 0, board->reg_shift);
+	}
+
+	return pci_default_setup(priv, board, port, idx);
+}
+
+/* the 99xx series comes with a range of device IDs and a variety
+ * of capabilities:
+ *
+ * 9900 has varying capabilities and can cascade to sub-controllers
+ *   (cascading should be purely internal)
+ * 9904 is hardwired with 4 serial ports
+ * 9912 and 9922 are hardwired with 2 serial ports
+ */
+static int pci_netmos_9900_numports(struct pci_dev *dev)
+{
+	unsigned int c = dev->class;
+	unsigned int pi;
+	unsigned short sub_serports;
+
+	pi = c & 0xff;
+
+	if (pi == 2)
+		return 1;
+
+	if ((pi == 0) && (dev->device == PCI_DEVICE_ID_NETMOS_9900)) {
+		/* two possibilities: 0x30ps encodes number of parallel and
+		 * serial ports, or 0x1000 indicates *something*. This is not
+		 * immediately obvious, since the 2s1p+4s configuration seems
+		 * to offer all functionality on functions 0..2, while still
+		 * advertising the same function 3 as the 4s+2s1p config.
+		 */
+		sub_serports = dev->subsystem_device & 0xf;
+		if (sub_serports > 0)
+			return sub_serports;
+
+		pci_err(dev, "NetMos/Mostech serial driver ignoring port on ambiguous config.\n");
+		return 0;
+	}
+
+	moan_device("unknown NetMos/Mostech program interface", dev);
+	return 0;
+}
+
+static int pci_netmos_init(struct pci_dev *dev)
+{
+	/* subdevice 0x00PS means <P> parallel, <S> serial */
+	unsigned int num_serial = dev->subsystem_device & 0xf;
+
+	if ((dev->device == PCI_DEVICE_ID_NETMOS_9901) ||
+		(dev->device == PCI_DEVICE_ID_NETMOS_9865))
+		return 0;
+
+	if (dev->subsystem_vendor == PCI_VENDOR_ID_IBM &&
+			dev->subsystem_device == 0x0299)
+		return 0;
+
+	switch (dev->device) { /* FALLTHROUGH on all */
+	case PCI_DEVICE_ID_NETMOS_9904:
+	case PCI_DEVICE_ID_NETMOS_9912:
+	case PCI_DEVICE_ID_NETMOS_9922:
+	case PCI_DEVICE_ID_NETMOS_9900:
+		num_serial = pci_netmos_9900_numports(dev);
+		break;
+
+	default:
+		break;
+	}
+
+	if (num_serial == 0) {
+		moan_device("unknown NetMos/Mostech device", dev);
+		return -ENODEV;
+	}
+
+	return num_serial;
+}
+
+/*
+ * These chips are available with optionally one parallel port and up to
+ * two serial ports. Unfortunately they all have the same product id.
+ *
+ * Basic configuration is done over a region of 32 I/O ports. The base
+ * ioport is called INTA or INTC, depending on docs/other drivers.
+ *
+ * The region of the 32 I/O ports is configured in POSIO0R...
+ */
+
+/* registers */
+#define ITE_887x_MISCR		0x9c
+#define ITE_887x_INTCBAR	0x78
+#define ITE_887x_UARTBAR	0x7c
+#define ITE_887x_PS0BAR		0x10
+#define ITE_887x_POSIO0		0x60
+
+/* I/O space size */
+#define ITE_887x_IOSIZE		32
+/* I/O space size (bits 26-24; 8 bytes = 011b) */
+#define ITE_887x_POSIO_IOSIZE_8		(3 << 24)
+/* I/O space size (bits 26-24; 32 bytes = 101b) */
+#define ITE_887x_POSIO_IOSIZE_32	(5 << 24)
+/* Decoding speed (1 = slow, 2 = medium, 3 = fast) */
+#define ITE_887x_POSIO_SPEED		(3 << 29)
+/* enable IO_Space bit */
+#define ITE_887x_POSIO_ENABLE		(1 << 31)
+
+/* inta_addr are the configuration addresses of the ITE */
+static const short inta_addr[] = { 0x2a0, 0x2c0, 0x220, 0x240, 0x1e0, 0x200, 0x280 };
+static int pci_ite887x_init(struct pci_dev *dev)
+{
+	int ret, i, type;
+	struct resource *iobase = NULL;
+	u32 miscr, uartbar, ioport;
+
+	/* search for the base-ioport */
+	for (i = 0; i < ARRAY_SIZE(inta_addr); i++) {
+		iobase = request_region(inta_addr[i], ITE_887x_IOSIZE,
+								"ite887x");
+		if (iobase != NULL) {
+			/* write POSIO0R - speed | size | ioport */
+			pci_write_config_dword(dev, ITE_887x_POSIO0,
+				ITE_887x_POSIO_ENABLE | ITE_887x_POSIO_SPEED |
+				ITE_887x_POSIO_IOSIZE_32 | inta_addr[i]);
+			/* write INTCBAR - ioport */
+			pci_write_config_dword(dev, ITE_887x_INTCBAR,
+								inta_addr[i]);
+			ret = inb(inta_addr[i]);
+			if (ret != 0xff) {
+				/* ioport connected */
+				break;
+			}
+			release_region(iobase->start, ITE_887x_IOSIZE);
+		}
+	}
+
+	if (i == ARRAY_SIZE(inta_addr)) {
+		pci_err(dev, "could not find iobase\n");
+		return -ENODEV;
+	}
+
+	/* start of undocumented type checking (see parport_pc.c) */
+	type = inb(iobase->start + 0x18) & 0x0f;
+
+	switch (type) {
+	case 0x2:	/* ITE8871 (1P) */
+	case 0xa:	/* ITE8875 (1P) */
+		ret = 0;
+		break;
+	case 0xe:	/* ITE8872 (2S1P) */
+		ret = 2;
+		break;
+	case 0x6:	/* ITE8873 (1S) */
+		ret = 1;
+		break;
+	case 0x8:	/* ITE8874 (2S) */
+		ret = 2;
+		break;
+	default:
+		moan_device("Unknown ITE887x", dev);
+		ret = -ENODEV;
+	}
+
+	/* configure all serial ports */
+	for (i = 0; i < ret; i++) {
+		/* read the I/O port from the device */
+		pci_read_config_dword(dev, ITE_887x_PS0BAR + (0x4 * (i + 1)),
+								&ioport);
+		ioport &= 0x0000FF00;	/* the actual base address */
+		pci_write_config_dword(dev, ITE_887x_POSIO0 + (0x4 * (i + 1)),
+			ITE_887x_POSIO_ENABLE | ITE_887x_POSIO_SPEED |
+			ITE_887x_POSIO_IOSIZE_8 | ioport);
+
+		/* write the ioport to the UARTBAR */
+		pci_read_config_dword(dev, ITE_887x_UARTBAR, &uartbar);
+		uartbar &= ~(0xffff << (16 * i));	/* clear half the reg */
+		uartbar |= (ioport << (16 * i));	/* set the ioport */
+		pci_write_config_dword(dev, ITE_887x_UARTBAR, uartbar);
+
+		/* get current config */
+		pci_read_config_dword(dev, ITE_887x_MISCR, &miscr);
+		/* disable interrupts (UARTx_Routing[3:0]) */
+		miscr &= ~(0xf << (12 - 4 * i));
+		/* activate the UART (UARTx_En) */
+		miscr |= 1 << (23 - i);
+		/* write new config with activated UART */
+		pci_write_config_dword(dev, ITE_887x_MISCR, miscr);
+	}
+
+	if (ret <= 0) {
+		/* the device has no UARTs if we get here */
+		release_region(iobase->start, ITE_887x_IOSIZE);
+	}
+
+	return ret;
+}
+
+static void pci_ite887x_exit(struct pci_dev *dev)
+{
+	u32 ioport;
+	/* the ioport is bit 0-15 in POSIO0R */
+	pci_read_config_dword(dev, ITE_887x_POSIO0, &ioport);
+	ioport &= 0xffff;
+	release_region(ioport, ITE_887x_IOSIZE);
+}
+
+/*
+ * Oxford Semiconductor Inc.
+ * Check if an OxSemi device is part of the Tornado range of devices.
+ */
+#define PCI_VENDOR_ID_ENDRUN			0x7401
+#define PCI_DEVICE_ID_ENDRUN_1588	0xe100
+
+static bool pci_oxsemi_tornado_p(struct pci_dev *dev)
+{
+	/* OxSemi Tornado devices are all 0xCxxx */
+	if (dev->vendor == PCI_VENDOR_ID_OXSEMI &&
+	    (dev->device & 0xf000) != 0xc000)
+		return false;
+
+	/* EndRun devices are all 0xExxx */
+	if (dev->vendor == PCI_VENDOR_ID_ENDRUN &&
+	    (dev->device & 0xf000) != 0xe000)
+		return false;
+
+	return true;
+}
+
+/*
+ * Determine the number of ports available on a Tornado device.
+ */
+static int pci_oxsemi_tornado_init(struct pci_dev *dev)
+{
+	u8 __iomem *p;
+	unsigned long deviceID;
+	unsigned int  number_uarts = 0;
+
+	if (!pci_oxsemi_tornado_p(dev))
+		return 0;
+
+	p = pci_iomap(dev, 0, 5);
+	if (p == NULL)
+		return -ENOMEM;
+
+	deviceID = ioread32(p);
+	/* Tornado device */
+	if (deviceID == 0x07000200) {
+		number_uarts = ioread8(p + 4);
+		pci_dbg(dev, "%d ports detected on %s PCI Express device\n",
+			number_uarts,
+			dev->vendor == PCI_VENDOR_ID_ENDRUN ?
+			"EndRun" : "Oxford");
+	}
+	pci_iounmap(dev, p);
+	return number_uarts;
+}
+
+/* Tornado-specific constants for the TCR and CPR registers; see below.  */
+#define OXSEMI_TORNADO_TCR_MASK	0xf
+#define OXSEMI_TORNADO_CPR_MASK	0x1ff
+#define OXSEMI_TORNADO_CPR_MIN	0x008
+#define OXSEMI_TORNADO_CPR_DEF	0x10f
+
+/*
+ * Determine the oversampling rate, the clock prescaler, and the clock
+ * divisor for the requested baud rate.  The clock rate is 62.5 MHz,
+ * which is four times the baud base, and the prescaler increments in
+ * steps of 1/8.  Therefore to make calculations on integers we need
+ * to use a scaled clock rate, which is the baud base multiplied by 32
+ * (or our assumed UART clock rate multiplied by 2).
+ *
+ * The allowed oversampling rates are from 4 up to 16 inclusive (values
+ * from 0 to 3 inclusive map to 16).  Likewise the clock prescaler allows
+ * values between 1.000 and 63.875 inclusive (operation for values from
+ * 0.000 to 0.875 has not been specified).  The clock divisor is the usual
+ * unsigned 16-bit integer.
+ *
+ * For the most accurate baud rate we use a table of predetermined
+ * oversampling rates and clock prescalers that records all possible
+ * products of the two parameters in the range from 4 up to 255 inclusive,
+ * and additionally 335 for the 1500000bps rate, with the prescaler scaled
+ * by 8.  The table is sorted by the decreasing value of the oversampling
+ * rate and ties are resolved by sorting by the decreasing value of the
+ * product.  This way preference is given to higher oversampling rates.
+ *
+ * We iterate over the table and choose the product of an oversampling
+ * rate and a clock prescaler that gives the lowest integer division
+ * result deviation, or if an exact integer divider is found we stop
+ * looking for it right away.  We do some fixup if the resulting clock
+ * divisor required would be out of its unsigned 16-bit integer range.
+ *
+ * Finally we abuse the supposed fractional part returned to encode the
+ * 4-bit value of the oversampling rate and the 9-bit value of the clock
+ * prescaler which will end up in the TCR and CPR/CPR2 registers.
+ */
+static unsigned int pci_oxsemi_tornado_get_divisor(struct uart_port *port,
+						   unsigned int baud,
+						   unsigned int *frac)
+{
+	static u8 p[][2] = {
+		{ 16, 14, }, { 16, 13, }, { 16, 12, }, { 16, 11, },
+		{ 16, 10, }, { 16,  9, }, { 16,  8, }, { 15, 17, },
+		{ 15, 16, }, { 15, 15, }, { 15, 14, }, { 15, 13, },
+		{ 15, 12, }, { 15, 11, }, { 15, 10, }, { 15,  9, },
+		{ 15,  8, }, { 14, 18, }, { 14, 17, }, { 14, 14, },
+		{ 14, 13, }, { 14, 12, }, { 14, 11, }, { 14, 10, },
+		{ 14,  9, }, { 14,  8, }, { 13, 19, }, { 13, 18, },
+		{ 13, 17, }, { 13, 13, }, { 13, 12, }, { 13, 11, },
+		{ 13, 10, }, { 13,  9, }, { 13,  8, }, { 12, 19, },
+		{ 12, 18, }, { 12, 17, }, { 12, 11, }, { 12,  9, },
+		{ 12,  8, }, { 11, 23, }, { 11, 22, }, { 11, 21, },
+		{ 11, 20, }, { 11, 19, }, { 11, 18, }, { 11, 17, },
+		{ 11, 11, }, { 11, 10, }, { 11,  9, }, { 11,  8, },
+		{ 10, 25, }, { 10, 23, }, { 10, 20, }, { 10, 19, },
+		{ 10, 17, }, { 10, 10, }, { 10,  9, }, { 10,  8, },
+		{  9, 27, }, {  9, 23, }, {  9, 21, }, {  9, 19, },
+		{  9, 18, }, {  9, 17, }, {  9,  9, }, {  9,  8, },
+		{  8, 31, }, {  8, 29, }, {  8, 23, }, {  8, 19, },
+		{  8, 17, }, {  8,  8, }, {  7, 35, }, {  7, 31, },
+		{  7, 29, }, {  7, 25, }, {  7, 23, }, {  7, 21, },
+		{  7, 19, }, {  7, 17, }, {  7, 15, }, {  7, 14, },
+		{  7, 13, }, {  7, 12, }, {  7, 11, }, {  7, 10, },
+		{  7,  9, }, {  7,  8, }, {  6, 41, }, {  6, 37, },
+		{  6, 31, }, {  6, 29, }, {  6, 23, }, {  6, 19, },
+		{  6, 17, }, {  6, 13, }, {  6, 11, }, {  6, 10, },
+		{  6,  9, }, {  6,  8, }, {  5, 67, }, {  5, 47, },
+		{  5, 43, }, {  5, 41, }, {  5, 37, }, {  5, 31, },
+		{  5, 29, }, {  5, 25, }, {  5, 23, }, {  5, 19, },
+		{  5, 17, }, {  5, 15, }, {  5, 13, }, {  5, 11, },
+		{  5, 10, }, {  5,  9, }, {  5,  8, }, {  4, 61, },
+		{  4, 59, }, {  4, 53, }, {  4, 47, }, {  4, 43, },
+		{  4, 41, }, {  4, 37, }, {  4, 31, }, {  4, 29, },
+		{  4, 23, }, {  4, 19, }, {  4, 17, }, {  4, 13, },
+		{  4,  9, }, {  4,  8, },
+	};
+	/* Scale the quotient for comparison to get the fractional part.  */
+	const unsigned int quot_scale = 65536;
+	unsigned int sclk = port->uartclk * 2;
+	unsigned int sdiv = DIV_ROUND_CLOSEST(sclk, baud);
+	unsigned int best_squot;
+	unsigned int squot;
+	unsigned int quot;
+	u16 cpr;
+	u8 tcr;
+	int i;
+
+	/* Old custom speed handling.  */
+	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) {
+		unsigned int cust_div = port->custom_divisor;
+
+		quot = cust_div & UART_DIV_MAX;
+		tcr = (cust_div >> 16) & OXSEMI_TORNADO_TCR_MASK;
+		cpr = (cust_div >> 20) & OXSEMI_TORNADO_CPR_MASK;
+		if (cpr < OXSEMI_TORNADO_CPR_MIN)
+			cpr = OXSEMI_TORNADO_CPR_DEF;
+	} else {
+		best_squot = quot_scale;
+		for (i = 0; i < ARRAY_SIZE(p); i++) {
+			unsigned int spre;
+			unsigned int srem;
+			u8 cp;
+			u8 tc;
+
+			tc = p[i][0];
+			cp = p[i][1];
+			spre = tc * cp;
+
+			srem = sdiv % spre;
+			if (srem > spre / 2)
+				srem = spre - srem;
+			squot = DIV_ROUND_CLOSEST(srem * quot_scale, spre);
+
+			if (srem == 0) {
+				tcr = tc;
+				cpr = cp;
+				quot = sdiv / spre;
+				break;
+			} else if (squot < best_squot) {
+				best_squot = squot;
+				tcr = tc;
+				cpr = cp;
+				quot = DIV_ROUND_CLOSEST(sdiv, spre);
+			}
+		}
+		while (tcr <= (OXSEMI_TORNADO_TCR_MASK + 1) >> 1 &&
+		       quot % 2 == 0) {
+			quot >>= 1;
+			tcr <<= 1;
+		}
+		while (quot > UART_DIV_MAX) {
+			if (tcr <= (OXSEMI_TORNADO_TCR_MASK + 1) >> 1) {
+				quot >>= 1;
+				tcr <<= 1;
+			} else if (cpr <= OXSEMI_TORNADO_CPR_MASK >> 1) {
+				quot >>= 1;
+				cpr <<= 1;
+			} else {
+				quot = quot * cpr / OXSEMI_TORNADO_CPR_MASK;
+				cpr = OXSEMI_TORNADO_CPR_MASK;
+			}
+		}
+	}
+
+	*frac = (cpr << 8) | (tcr & OXSEMI_TORNADO_TCR_MASK);
+	return quot;
+}
+
+/*
+ * Set the oversampling rate in the transmitter clock cycle register (TCR),
+ * the clock prescaler in the clock prescaler register (CPR and CPR2), and
+ * the clock divisor in the divisor latch (DLL and DLM).  Note that for
+ * backwards compatibility any write to CPR clears CPR2 and therefore CPR
+ * has to be written first, followed by CPR2, which occupies the location
+ * of CKS used with earlier UART designs.
+ */
+static void pci_oxsemi_tornado_set_divisor(struct uart_port *port,
+					   unsigned int baud,
+					   unsigned int quot,
+					   unsigned int quot_frac)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	u8 cpr2 = quot_frac >> 16;
+	u8 cpr = quot_frac >> 8;
+	u8 tcr = quot_frac;
+
+	serial_icr_write(up, UART_TCR, tcr);
+	serial_icr_write(up, UART_CPR, cpr);
+	serial_icr_write(up, UART_CKS, cpr2);
+	serial8250_do_set_divisor(port, baud, quot, 0);
+}
+
+/*
+ * For Tornado devices we force MCR[7] set for the Divide-by-M N/8 baud rate
+ * generator prescaler (CPR and CPR2).  Otherwise no prescaler would be used.
+ */
+static void pci_oxsemi_tornado_set_mctrl(struct uart_port *port,
+					 unsigned int mctrl)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	up->mcr |= UART_MCR_CLKSEL;
+	serial8250_do_set_mctrl(port, mctrl);
+}
+
+/*
+ * We require EFR features for clock programming, so set UPF_FULL_PROBE
+ * for full probing regardless of CONFIG_SERIAL_8250_16550A_VARIANTS setting.
+ */
+static int pci_oxsemi_tornado_setup(struct serial_private *priv,
+				    const struct pciserial_board *board,
+				    struct uart_8250_port *up, int idx)
+{
+	struct pci_dev *dev = priv->dev;
+
+	if (pci_oxsemi_tornado_p(dev)) {
+		up->port.flags |= UPF_FULL_PROBE;
+		up->port.get_divisor = pci_oxsemi_tornado_get_divisor;
+		up->port.set_divisor = pci_oxsemi_tornado_set_divisor;
+		up->port.set_mctrl = pci_oxsemi_tornado_set_mctrl;
+	}
+
+	return pci_default_setup(priv, board, up, idx);
+}
+
+#define QPCR_TEST_FOR1		0x3F
+#define QPCR_TEST_GET1		0x00
+#define QPCR_TEST_FOR2		0x40
+#define QPCR_TEST_GET2		0x40
+#define QPCR_TEST_FOR3		0x80
+#define QPCR_TEST_GET3		0x40
+#define QPCR_TEST_FOR4		0xC0
+#define QPCR_TEST_GET4		0x80
+
+#define QOPR_CLOCK_X1		0x0000
+#define QOPR_CLOCK_X2		0x0001
+#define QOPR_CLOCK_X4		0x0002
+#define QOPR_CLOCK_X8		0x0003
+#define QOPR_CLOCK_RATE_MASK	0x0003
+
+/* Quatech devices have their own extra interface features */
+static struct pci_device_id quatech_cards[] = {
+	{ PCI_DEVICE_DATA(QUATECH, QSC100,   1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC100,   1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC100E,  0) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC200,   1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC200E,  0) },
+	{ PCI_DEVICE_DATA(QUATECH, ESC100D,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, ESC100M,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCP100,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCP100,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCP200,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCP200,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, ESCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, SSCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCLP200, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCLP200, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, SSCLP200, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, SPPXP_100, 0) },
+	{ 0, }
+};
+
+static int pci_quatech_rqopr(struct uart_8250_port *port)
+{
+	unsigned long base = port->port.iobase;
+	u8 LCR, val;
+
+	LCR = inb(base + UART_LCR);
+	outb(0xBF, base + UART_LCR);
+	val = inb(base + UART_SCR);
+	outb(LCR, base + UART_LCR);
+	return val;
+}
+
+static void pci_quatech_wqopr(struct uart_8250_port *port, u8 qopr)
+{
+	unsigned long base = port->port.iobase;
+	u8 LCR;
+
+	LCR = inb(base + UART_LCR);
+	outb(0xBF, base + UART_LCR);
+	inb(base + UART_SCR);
+	outb(qopr, base + UART_SCR);
+	outb(LCR, base + UART_LCR);
+}
+
+static int pci_quatech_rqmcr(struct uart_8250_port *port)
+{
+	unsigned long base = port->port.iobase;
+	u8 LCR, val, qmcr;
+
+	LCR = inb(base + UART_LCR);
+	outb(0xBF, base + UART_LCR);
+	val = inb(base + UART_SCR);
+	outb(val | 0x10, base + UART_SCR);
+	qmcr = inb(base + UART_MCR);
+	outb(val, base + UART_SCR);
+	outb(LCR, base + UART_LCR);
+
+	return qmcr;
+}
+
+static void pci_quatech_wqmcr(struct uart_8250_port *port, u8 qmcr)
+{
+	unsigned long base = port->port.iobase;
+	u8 LCR, val;
+
+	LCR = inb(base + UART_LCR);
+	outb(0xBF, base + UART_LCR);
+	val = inb(base + UART_SCR);
+	outb(val | 0x10, base + UART_SCR);
+	outb(qmcr, base + UART_MCR);
+	outb(val, base + UART_SCR);
+	outb(LCR, base + UART_LCR);
+}
+
+static int pci_quatech_has_qmcr(struct uart_8250_port *port)
+{
+	unsigned long base = port->port.iobase;
+	u8 LCR, val;
+
+	LCR = inb(base + UART_LCR);
+	outb(0xBF, base + UART_LCR);
+	val = inb(base + UART_SCR);
+	if (val & 0x20) {
+		outb(0x80, UART_LCR);
+		if (!(inb(UART_SCR) & 0x20)) {
+			outb(LCR, base + UART_LCR);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int pci_quatech_test(struct uart_8250_port *port)
+{
+	u8 reg, qopr;
+
+	qopr = pci_quatech_rqopr(port);
+	pci_quatech_wqopr(port, qopr & QPCR_TEST_FOR1);
+	reg = pci_quatech_rqopr(port) & 0xC0;
+	if (reg != QPCR_TEST_GET1)
+		return -EINVAL;
+	pci_quatech_wqopr(port, (qopr & QPCR_TEST_FOR1)|QPCR_TEST_FOR2);
+	reg = pci_quatech_rqopr(port) & 0xC0;
+	if (reg != QPCR_TEST_GET2)
+		return -EINVAL;
+	pci_quatech_wqopr(port, (qopr & QPCR_TEST_FOR1)|QPCR_TEST_FOR3);
+	reg = pci_quatech_rqopr(port) & 0xC0;
+	if (reg != QPCR_TEST_GET3)
+		return -EINVAL;
+	pci_quatech_wqopr(port, (qopr & QPCR_TEST_FOR1)|QPCR_TEST_FOR4);
+	reg = pci_quatech_rqopr(port) & 0xC0;
+	if (reg != QPCR_TEST_GET4)
+		return -EINVAL;
+
+	pci_quatech_wqopr(port, qopr);
+	return 0;
+}
+
+static int pci_quatech_clock(struct uart_8250_port *port)
+{
+	u8 qopr, reg, set;
+	unsigned long clock;
+
+	if (pci_quatech_test(port) < 0)
+		return 1843200;
+
+	qopr = pci_quatech_rqopr(port);
+
+	pci_quatech_wqopr(port, qopr & ~QOPR_CLOCK_X8);
+	reg = pci_quatech_rqopr(port);
+	if (reg & QOPR_CLOCK_X8) {
+		clock = 1843200;
+		goto out;
+	}
+	pci_quatech_wqopr(port, qopr | QOPR_CLOCK_X8);
+	reg = pci_quatech_rqopr(port);
+	if (!(reg & QOPR_CLOCK_X8)) {
+		clock = 1843200;
+		goto out;
+	}
+	reg &= QOPR_CLOCK_X8;
+	if (reg == QOPR_CLOCK_X2) {
+		clock =  3685400;
+		set = QOPR_CLOCK_X2;
+	} else if (reg == QOPR_CLOCK_X4) {
+		clock = 7372800;
+		set = QOPR_CLOCK_X4;
+	} else if (reg == QOPR_CLOCK_X8) {
+		clock = 14745600;
+		set = QOPR_CLOCK_X8;
+	} else {
+		clock = 1843200;
+		set = QOPR_CLOCK_X1;
+	}
+	qopr &= ~QOPR_CLOCK_RATE_MASK;
+	qopr |= set;
+
+out:
+	pci_quatech_wqopr(port, qopr);
+	return clock;
+}
+
+static int pci_quatech_rs422(struct uart_8250_port *port)
+{
+	u8 qmcr;
+	int rs422 = 0;
+
+	if (!pci_quatech_has_qmcr(port))
+		return 0;
+	qmcr = pci_quatech_rqmcr(port);
+	pci_quatech_wqmcr(port, 0xFF);
+	if (pci_quatech_rqmcr(port))
+		rs422 = 1;
+	pci_quatech_wqmcr(port, qmcr);
+	return rs422;
+}
+
+static int pci_quatech_init(struct pci_dev *dev)
+{
+	const struct pci_device_id *match;
+	bool amcc = false;
+
+	match = pci_match_id(quatech_cards, dev);
+	if (match)
+		amcc = match->driver_data;
+	else
+		pci_err(dev, "unknown port type '0x%04X'.\n", dev->device);
+
+	if (amcc) {
+		unsigned long base = pci_resource_start(dev, 0);
+		if (base) {
+			u32 tmp;
+
+			outl(inl(base + 0x38) | 0x00002000, base + 0x38);
+			tmp = inl(base + 0x3c);
+			outl(tmp | 0x01000000, base + 0x3c);
+			outl(tmp & ~0x01000000, base + 0x3c);
+		}
+	}
+	return 0;
+}
+
+static int pci_quatech_setup(struct serial_private *priv,
+		  const struct pciserial_board *board,
+		  struct uart_8250_port *port, int idx)
+{
+	/* Needed by pci_quatech calls below */
+	port->port.iobase = pci_resource_start(priv->dev, FL_GET_BASE(board->flags));
+	/* Set up the clocking */
+	port->port.uartclk = pci_quatech_clock(port);
+	/* For now just warn about RS422 */
+	if (pci_quatech_rs422(port))
+		pci_warn(priv->dev, "software control of RS422 features not currently supported.\n");
+	return pci_default_setup(priv, board, port, idx);
+}
+
+static int pci_default_setup(struct serial_private *priv,
+		  const struct pciserial_board *board,
+		  struct uart_8250_port *port, int idx)
+{
+	unsigned int bar, offset = board->first_offset, maxnr;
+
+	bar = FL_GET_BASE(board->flags);
+	if (board->flags & FL_BASE_BARS)
+		bar += idx;
+	else
+		offset += idx * board->uart_offset;
+
+	maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >>
+		(board->reg_shift + 3);
+
+	if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
+		return 1;
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+static int
+ce4100_serial_setup(struct serial_private *priv,
+		  const struct pciserial_board *board,
+		  struct uart_8250_port *port, int idx)
+{
+	int ret;
+
+	ret = setup_port(priv, port, idx, 0, board->reg_shift);
+	port->port.iotype = UPIO_MEM32;
+	port->port.type = PORT_XSCALE;
+	port->port.flags = (port->port.flags | UPF_FIXED_PORT | UPF_FIXED_TYPE);
+	port->port.regshift = 2;
+
+	return ret;
+}
+
+static int
+pci_omegapci_setup(struct serial_private *priv,
+		      const struct pciserial_board *board,
+		      struct uart_8250_port *port, int idx)
+{
+	return setup_port(priv, port, 2, idx * 8, 0);
+}
+
+static int
+pci_brcm_trumanage_setup(struct serial_private *priv,
+			 const struct pciserial_board *board,
+			 struct uart_8250_port *port, int idx)
+{
+	int ret = pci_default_setup(priv, board, port, idx);
+
+	port->port.type = PORT_BRCM_TRUMANAGE;
+	port->port.flags = (port->port.flags | UPF_FIXED_PORT | UPF_FIXED_TYPE);
+	return ret;
+}
+
+/* RTS will control by MCR if this bit is 0 */
+#define FINTEK_RTS_CONTROL_BY_HW	BIT(4)
+/* only worked with FINTEK_RTS_CONTROL_BY_HW on */
+#define FINTEK_RTS_INVERT		BIT(5)
+
+/* We should do proper H/W transceiver setting before change to RS485 mode */
+static int pci_fintek_rs485_config(struct uart_port *port, struct ktermios *termios,
+			       struct serial_rs485 *rs485)
+{
+	struct pci_dev *pci_dev = to_pci_dev(port->dev);
+	u8 setting;
+	u8 *index = (u8 *) port->private_data;
+
+	pci_read_config_byte(pci_dev, 0x40 + 8 * *index + 7, &setting);
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		/* Enable RTS H/W control mode */
+		setting |= FINTEK_RTS_CONTROL_BY_HW;
+
+		if (rs485->flags & SER_RS485_RTS_ON_SEND) {
+			/* RTS driving high on TX */
+			setting &= ~FINTEK_RTS_INVERT;
+		} else {
+			/* RTS driving low on TX */
+			setting |= FINTEK_RTS_INVERT;
+		}
+	} else {
+		/* Disable RTS H/W control mode */
+		setting &= ~(FINTEK_RTS_CONTROL_BY_HW | FINTEK_RTS_INVERT);
+	}
+
+	pci_write_config_byte(pci_dev, 0x40 + 8 * *index + 7, setting);
+
+	return 0;
+}
+
+static const struct serial_rs485 pci_fintek_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
+	/* F81504/508/512 does not support RTS delay before or after send */
+};
+
+static int pci_fintek_setup(struct serial_private *priv,
+			    const struct pciserial_board *board,
+			    struct uart_8250_port *port, int idx)
+{
+	struct pci_dev *pdev = priv->dev;
+	u8 *data;
+	u8 config_base;
+	u16 iobase;
+
+	config_base = 0x40 + 0x08 * idx;
+
+	/* Get the io address from configuration space */
+	pci_read_config_word(pdev, config_base + 4, &iobase);
+
+	pci_dbg(pdev, "idx=%d iobase=0x%x", idx, iobase);
+
+	port->port.iotype = UPIO_PORT;
+	port->port.iobase = iobase;
+	port->port.rs485_config = pci_fintek_rs485_config;
+	port->port.rs485_supported = pci_fintek_rs485_supported;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(u8), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* preserve index in PCI configuration space */
+	*data = idx;
+	port->port.private_data = data;
+
+	return 0;
+}
+
+static int pci_fintek_init(struct pci_dev *dev)
+{
+	unsigned long iobase;
+	u32 max_port, i;
+	resource_size_t bar_data[3];
+	u8 config_base;
+	struct serial_private *priv = pci_get_drvdata(dev);
+
+	if (!(pci_resource_flags(dev, 5) & IORESOURCE_IO) ||
+			!(pci_resource_flags(dev, 4) & IORESOURCE_IO) ||
+			!(pci_resource_flags(dev, 3) & IORESOURCE_IO))
+		return -ENODEV;
+
+	switch (dev->device) {
+	case 0x1104: /* 4 ports */
+	case 0x1108: /* 8 ports */
+		max_port = dev->device & 0xff;
+		break;
+	case 0x1112: /* 12 ports */
+		max_port = 12;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Get the io address dispatch from the BIOS */
+	bar_data[0] = pci_resource_start(dev, 5);
+	bar_data[1] = pci_resource_start(dev, 4);
+	bar_data[2] = pci_resource_start(dev, 3);
+
+	for (i = 0; i < max_port; ++i) {
+		/* UART0 configuration offset start from 0x40 */
+		config_base = 0x40 + 0x08 * i;
+
+		/* Calculate Real IO Port */
+		iobase = (bar_data[i / 4] & 0xffffffe0) + (i % 4) * 8;
+
+		/* Enable UART I/O port */
+		pci_write_config_byte(dev, config_base + 0x00, 0x01);
+
+		/* Select 128-byte FIFO and 8x FIFO threshold */
+		pci_write_config_byte(dev, config_base + 0x01, 0x33);
+
+		/* LSB UART */
+		pci_write_config_byte(dev, config_base + 0x04,
+				(u8)(iobase & 0xff));
+
+		/* MSB UART */
+		pci_write_config_byte(dev, config_base + 0x05,
+				(u8)((iobase & 0xff00) >> 8));
+
+		pci_write_config_byte(dev, config_base + 0x06, dev->irq);
+
+		if (!priv) {
+			/* First init without port data
+			 * force init to RS232 Mode
+			 */
+			pci_write_config_byte(dev, config_base + 0x07, 0x01);
+		}
+	}
+
+	return max_port;
+}
+
+static void f815xxa_mem_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct f815xxa_data *data = p->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&data->lock, flags);
+	writeb(value, p->membase + offset);
+	readb(p->membase + UART_SCR); /* Dummy read for flush pcie tx queue */
+	spin_unlock_irqrestore(&data->lock, flags);
+}
+
+static int pci_fintek_f815xxa_setup(struct serial_private *priv,
+			    const struct pciserial_board *board,
+			    struct uart_8250_port *port, int idx)
+{
+	struct pci_dev *pdev = priv->dev;
+	struct f815xxa_data *data;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->idx = idx;
+	spin_lock_init(&data->lock);
+
+	port->port.private_data = data;
+	port->port.iotype = UPIO_MEM;
+	port->port.flags |= UPF_IOREMAP;
+	port->port.mapbase = pci_resource_start(pdev, 0) + 8 * idx;
+	port->port.serial_out = f815xxa_mem_serial_out;
+
+	return 0;
+}
+
+static int pci_fintek_f815xxa_init(struct pci_dev *dev)
+{
+	u32 max_port, i;
+	int config_base;
+
+	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM))
+		return -ENODEV;
+
+	switch (dev->device) {
+	case 0x1204: /* 4 ports */
+	case 0x1208: /* 8 ports */
+		max_port = dev->device & 0xff;
+		break;
+	case 0x1212: /* 12 ports */
+		max_port = 12;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Set to mmio decode */
+	pci_write_config_byte(dev, 0x209, 0x40);
+
+	for (i = 0; i < max_port; ++i) {
+		/* UART0 configuration offset start from 0x2A0 */
+		config_base = 0x2A0 + 0x08 * i;
+
+		/* Select 128-byte FIFO and 8x FIFO threshold */
+		pci_write_config_byte(dev, config_base + 0x01, 0x33);
+
+		/* Enable UART I/O port */
+		pci_write_config_byte(dev, config_base + 0, 0x01);
+	}
+
+	return max_port;
+}
+
+static int skip_tx_en_setup(struct serial_private *priv,
+			const struct pciserial_board *board,
+			struct uart_8250_port *port, int idx)
+{
+	port->port.quirks |= UPQ_NO_TXEN_TEST;
+	pci_dbg(priv->dev,
+		"serial8250: skipping TxEn test for device [%04x:%04x] subsystem [%04x:%04x]\n",
+		priv->dev->vendor, priv->dev->device,
+		priv->dev->subsystem_vendor, priv->dev->subsystem_device);
+
+	return pci_default_setup(priv, board, port, idx);
+}
+
+static void kt_handle_break(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	/*
+	 * On receipt of a BI, serial device in Intel ME (Intel
+	 * management engine) needs to have its fifos cleared for sane
+	 * SOL (Serial Over Lan) output.
+	 */
+	serial8250_clear_and_reinit_fifos(up);
+}
+
+static unsigned int kt_serial_in(struct uart_port *p, int offset)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int val;
+
+	/*
+	 * When the Intel ME (management engine) gets reset its serial
+	 * port registers could return 0 momentarily.  Functions like
+	 * serial8250_console_write, read and save the IER, perform
+	 * some operation and then restore it.  In order to avoid
+	 * setting IER register inadvertently to 0, if the value read
+	 * is 0, double check with ier value in uart_8250_port and use
+	 * that instead.  up->ier should be the same value as what is
+	 * currently configured.
+	 */
+	val = inb(p->iobase + offset);
+	if (offset == UART_IER) {
+		if (val == 0)
+			val = up->ier;
+	}
+	return val;
+}
+
+static int kt_serial_setup(struct serial_private *priv,
+			   const struct pciserial_board *board,
+			   struct uart_8250_port *port, int idx)
+{
+	port->port.flags |= UPF_BUG_THRE;
+	port->port.serial_in = kt_serial_in;
+	port->port.handle_break = kt_handle_break;
+	return skip_tx_en_setup(priv, board, port, idx);
+}
+
+static int pci_eg20t_init(struct pci_dev *dev)
+{
+#if defined(CONFIG_SERIAL_PCH_UART) || defined(CONFIG_SERIAL_PCH_UART_MODULE)
+	return -ENODEV;
+#else
+	return 0;
+#endif
+}
+
+static int
+pci_wch_ch353_setup(struct serial_private *priv,
+		    const struct pciserial_board *board,
+		    struct uart_8250_port *port, int idx)
+{
+	port->port.flags |= UPF_FIXED_TYPE;
+	port->port.type = PORT_16550A;
+	return pci_default_setup(priv, board, port, idx);
+}
+
+static int
+pci_wch_ch355_setup(struct serial_private *priv,
+		const struct pciserial_board *board,
+		struct uart_8250_port *port, int idx)
+{
+	port->port.flags |= UPF_FIXED_TYPE;
+	port->port.type = PORT_16550A;
+	return pci_default_setup(priv, board, port, idx);
+}
+
+static int
+pci_wch_ch38x_setup(struct serial_private *priv,
+		    const struct pciserial_board *board,
+		    struct uart_8250_port *port, int idx)
+{
+	port->port.flags |= UPF_FIXED_TYPE;
+	port->port.type = PORT_16850;
+	return pci_default_setup(priv, board, port, idx);
+}
+
+
+#define CH384_XINT_ENABLE_REG   0xEB
+#define CH384_XINT_ENABLE_BIT   0x02
+
+static int pci_wch_ch38x_init(struct pci_dev *dev)
+{
+	int max_port;
+	unsigned long iobase;
+
+
+	switch (dev->device) {
+	case 0x3853: /* 8 ports */
+		max_port = 8;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	iobase = pci_resource_start(dev, 0);
+	outb(CH384_XINT_ENABLE_BIT, iobase + CH384_XINT_ENABLE_REG);
+
+	return max_port;
+}
+
+static void pci_wch_ch38x_exit(struct pci_dev *dev)
+{
+	unsigned long iobase;
+
+	iobase = pci_resource_start(dev, 0);
+	outb(0x0, iobase + CH384_XINT_ENABLE_REG);
+}
+
+
+static int
+pci_sunix_setup(struct serial_private *priv,
+		const struct pciserial_board *board,
+		struct uart_8250_port *port, int idx)
+{
+	int bar;
+	int offset;
+
+	port->port.flags |= UPF_FIXED_TYPE;
+	port->port.type = PORT_SUNIX;
+
+	if (idx < 4) {
+		bar = 0;
+		offset = idx * board->uart_offset;
+	} else {
+		bar = 1;
+		idx -= 4;
+		idx = div_s64_rem(idx, 4, &offset);
+		offset = idx * 64 + offset * board->uart_offset;
+	}
+
+	return setup_port(priv, port, bar, offset, 0);
+}
+
+static int
+pci_moxa_setup(struct serial_private *priv,
+		const struct pciserial_board *board,
+		struct uart_8250_port *port, int idx)
+{
+	unsigned int bar = FL_GET_BASE(board->flags);
+	int offset;
+
+	if (board->num_ports == 4 && idx == 3)
+		offset = 7 * board->uart_offset;
+	else
+		offset = idx * board->uart_offset;
+
+	return setup_port(priv, port, bar, offset, 0);
+}
+
+#define PCI_VENDOR_ID_SBSMODULARIO	0x124B
+#define PCI_SUBVENDOR_ID_SBSMODULARIO	0x124B
+#define PCI_DEVICE_ID_OCTPRO		0x0001
+#define PCI_SUBDEVICE_ID_OCTPRO232	0x0108
+#define PCI_SUBDEVICE_ID_OCTPRO422	0x0208
+#define PCI_SUBDEVICE_ID_POCTAL232	0x0308
+#define PCI_SUBDEVICE_ID_POCTAL422	0x0408
+#define PCI_SUBDEVICE_ID_SIIG_DUAL_00	0x2500
+#define PCI_SUBDEVICE_ID_SIIG_DUAL_30	0x2530
+#define PCI_VENDOR_ID_ADVANTECH		0x13fe
+#define PCI_DEVICE_ID_INTEL_CE4100_UART 0x2e66
+#define PCI_DEVICE_ID_ADVANTECH_PCI1600	0x1600
+#define PCI_DEVICE_ID_ADVANTECH_PCI1600_1611	0x1611
+#define PCI_DEVICE_ID_ADVANTECH_PCI3620	0x3620
+#define PCI_DEVICE_ID_ADVANTECH_PCI3618	0x3618
+#define PCI_DEVICE_ID_ADVANTECH_PCIf618	0xf618
+#define PCI_DEVICE_ID_TITAN_200I	0x8028
+#define PCI_DEVICE_ID_TITAN_400I	0x8048
+#define PCI_DEVICE_ID_TITAN_800I	0x8088
+#define PCI_DEVICE_ID_TITAN_800EH	0xA007
+#define PCI_DEVICE_ID_TITAN_800EHB	0xA008
+#define PCI_DEVICE_ID_TITAN_400EH	0xA009
+#define PCI_DEVICE_ID_TITAN_100E	0xA010
+#define PCI_DEVICE_ID_TITAN_200E	0xA012
+#define PCI_DEVICE_ID_TITAN_400E	0xA013
+#define PCI_DEVICE_ID_TITAN_800E	0xA014
+#define PCI_DEVICE_ID_TITAN_200EI	0xA016
+#define PCI_DEVICE_ID_TITAN_200EISI	0xA017
+#define PCI_DEVICE_ID_TITAN_200V3	0xA306
+#define PCI_DEVICE_ID_TITAN_400V3	0xA310
+#define PCI_DEVICE_ID_TITAN_410V3	0xA312
+#define PCI_DEVICE_ID_TITAN_800V3	0xA314
+#define PCI_DEVICE_ID_TITAN_800V3B	0xA315
+#define PCI_DEVICE_ID_OXSEMI_16PCI958	0x9538
+#define PCIE_DEVICE_ID_NEO_2_OX_IBM	0x00F6
+#define PCI_DEVICE_ID_PLX_CRONYX_OMEGA	0xc001
+#define PCI_DEVICE_ID_INTEL_PATSBURG_KT 0x1d3d
+#define PCI_VENDOR_ID_WCH		0x4348
+#define PCI_DEVICE_ID_WCH_CH352_2S	0x3253
+#define PCI_DEVICE_ID_WCH_CH353_4S	0x3453
+#define PCI_DEVICE_ID_WCH_CH353_2S1PF	0x5046
+#define PCI_DEVICE_ID_WCH_CH353_1S1P	0x5053
+#define PCI_DEVICE_ID_WCH_CH353_2S1P	0x7053
+#define PCI_DEVICE_ID_WCH_CH355_4S	0x7173
+#define PCI_VENDOR_ID_AGESTAR		0x5372
+#define PCI_DEVICE_ID_AGESTAR_9375	0x6872
+#define PCI_DEVICE_ID_BROADCOM_TRUMANAGE 0x160a
+#define PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800 0x818e
+
+#define PCIE_VENDOR_ID_WCH		0x1c00
+#define PCIE_DEVICE_ID_WCH_CH382_2S1P	0x3250
+#define PCIE_DEVICE_ID_WCH_CH384_4S	0x3470
+#define PCIE_DEVICE_ID_WCH_CH384_8S	0x3853
+#define PCIE_DEVICE_ID_WCH_CH382_2S	0x3253
+
+#define	PCI_DEVICE_ID_MOXA_CP102E	0x1024
+#define	PCI_DEVICE_ID_MOXA_CP102EL	0x1025
+#define	PCI_DEVICE_ID_MOXA_CP104EL_A	0x1045
+#define	PCI_DEVICE_ID_MOXA_CP114EL	0x1144
+#define	PCI_DEVICE_ID_MOXA_CP116E_A_A	0x1160
+#define	PCI_DEVICE_ID_MOXA_CP116E_A_B	0x1161
+#define	PCI_DEVICE_ID_MOXA_CP118EL_A	0x1182
+#define	PCI_DEVICE_ID_MOXA_CP118E_A_I	0x1183
+#define	PCI_DEVICE_ID_MOXA_CP132EL	0x1322
+#define	PCI_DEVICE_ID_MOXA_CP134EL_A	0x1342
+#define	PCI_DEVICE_ID_MOXA_CP138E_A	0x1381
+#define	PCI_DEVICE_ID_MOXA_CP168EL_A	0x1683
+
+/* Unknown vendors/cards - this should not be in linux/pci_ids.h */
+#define PCI_SUBDEVICE_ID_UNKNOWN_0x1584	0x1584
+#define PCI_SUBDEVICE_ID_UNKNOWN_0x1588	0x1588
+
+/*
+ * Master list of serial port init/setup/exit quirks.
+ * This does not describe the general nature of the port.
+ * (ie, baud base, number and location of ports, etc)
+ *
+ * This list is ordered alphabetically by vendor then device.
+ * Specific entries must come before more generic entries.
+ */
+static struct pci_serial_quirk pci_serial_quirks[] = {
+	/*
+	* ADDI-DATA GmbH communication cards <info@addi-data.com>
+	*/
+	{
+		.vendor         = PCI_VENDOR_ID_AMCC,
+		.device         = PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = addidata_apci7800_setup,
+	},
+	/*
+	 * AFAVLAB cards - these may be called via parport_serial
+	 *  It is not clear whether this applies to all products.
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_AFAVLAB,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= afavlab_setup,
+	},
+	/*
+	 * HP Diva
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_HP,
+		.device		= PCI_DEVICE_ID_HP_DIVA,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_hp_diva_init,
+		.setup		= pci_hp_diva_setup,
+	},
+	/*
+	 * HPE PCI serial device
+	 */
+	{
+		.vendor         = PCI_VENDOR_ID_HP_3PAR,
+		.device         = PCI_DEVICE_ID_HPE_PCI_SERIAL,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup		= pci_hp_diva_setup,
+	},
+	/*
+	 * Intel
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_80960_RP,
+		.subvendor	= 0xe4bf,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_inteli960ni_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_8257X_SOL,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= skip_tx_en_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_82573L_SOL,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= skip_tx_en_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_82573E_SOL,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= skip_tx_en_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_CE4100_UART,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= ce4100_serial_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_PATSBURG_KT,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= kt_serial_setup,
+	},
+	/*
+	 * ITE
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_ITE,
+		.device		= PCI_DEVICE_ID_ITE_8872,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ite887x_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ite887x_exit,
+	},
+	/*
+	 * National Instruments
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PCI23216,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PCI2328,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PCI2324,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PCI2322,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PCI2324I,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PCI2322I,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PXI8420_23216,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PXI8420_2328,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PXI8420_2324,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PXI8420_2322,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PXI8422_2324,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_DEVICE_ID_NI_PXI8422_2322,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8420_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_ni8420_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_NI,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_ni8430_init,
+		.setup		= pci_ni8430_setup,
+		.exit		= pci_ni8430_exit,
+	},
+	/* Quatech */
+	{
+		.vendor		= PCI_VENDOR_ID_QUATECH,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_quatech_init,
+		.setup		= pci_quatech_setup,
+	},
+	/*
+	 * Panacom
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_PANACOM,
+		.device		= PCI_DEVICE_ID_PANACOM_QUADMODEM,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_plx9050_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_plx9050_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_PANACOM,
+		.device		= PCI_DEVICE_ID_PANACOM_DUALMODEM,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_plx9050_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_plx9050_exit,
+	},
+	/*
+	 * PLX
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_PLX,
+		.device		= PCI_DEVICE_ID_PLX_9050,
+		.subvendor	= PCI_SUBVENDOR_ID_EXSYS,
+		.subdevice	= PCI_SUBDEVICE_ID_EXSYS_4055,
+		.init		= pci_plx9050_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_plx9050_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_PLX,
+		.device		= PCI_DEVICE_ID_PLX_9050,
+		.subvendor	= PCI_SUBVENDOR_ID_KEYSPAN,
+		.subdevice	= PCI_SUBDEVICE_ID_KEYSPAN_SX2,
+		.init		= pci_plx9050_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_plx9050_exit,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_PLX,
+		.device		= PCI_DEVICE_ID_PLX_ROMULUS,
+		.subvendor	= PCI_VENDOR_ID_PLX,
+		.subdevice	= PCI_DEVICE_ID_PLX_ROMULUS,
+		.init		= pci_plx9050_init,
+		.setup		= pci_default_setup,
+		.exit		= pci_plx9050_exit,
+	},
+	/*
+	 * SBS Technologies, Inc., PMC-OCTALPRO 232
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_SBSMODULARIO,
+		.device		= PCI_DEVICE_ID_OCTPRO,
+		.subvendor	= PCI_SUBVENDOR_ID_SBSMODULARIO,
+		.subdevice	= PCI_SUBDEVICE_ID_OCTPRO232,
+		.init		= sbs_init,
+		.setup		= sbs_setup,
+		.exit		= sbs_exit,
+	},
+	/*
+	 * SBS Technologies, Inc., PMC-OCTALPRO 422
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_SBSMODULARIO,
+		.device		= PCI_DEVICE_ID_OCTPRO,
+		.subvendor	= PCI_SUBVENDOR_ID_SBSMODULARIO,
+		.subdevice	= PCI_SUBDEVICE_ID_OCTPRO422,
+		.init		= sbs_init,
+		.setup		= sbs_setup,
+		.exit		= sbs_exit,
+	},
+	/*
+	 * SBS Technologies, Inc., P-Octal 232
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_SBSMODULARIO,
+		.device		= PCI_DEVICE_ID_OCTPRO,
+		.subvendor	= PCI_SUBVENDOR_ID_SBSMODULARIO,
+		.subdevice	= PCI_SUBDEVICE_ID_POCTAL232,
+		.init		= sbs_init,
+		.setup		= sbs_setup,
+		.exit		= sbs_exit,
+	},
+	/*
+	 * SBS Technologies, Inc., P-Octal 422
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_SBSMODULARIO,
+		.device		= PCI_DEVICE_ID_OCTPRO,
+		.subvendor	= PCI_SUBVENDOR_ID_SBSMODULARIO,
+		.subdevice	= PCI_SUBDEVICE_ID_POCTAL422,
+		.init		= sbs_init,
+		.setup		= sbs_setup,
+		.exit		= sbs_exit,
+	},
+	/*
+	 * SIIG cards - these may be called via parport_serial
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_SIIG,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_siig_init,
+		.setup		= pci_siig_setup,
+	},
+	/*
+	 * Titan cards
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_TITAN,
+		.device		= PCI_DEVICE_ID_TITAN_400L,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= titan_400l_800l_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_TITAN,
+		.device		= PCI_DEVICE_ID_TITAN_800L,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= titan_400l_800l_setup,
+	},
+	/*
+	 * Timedia cards
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_TIMEDIA,
+		.device		= PCI_DEVICE_ID_TIMEDIA_1889,
+		.subvendor	= PCI_VENDOR_ID_TIMEDIA,
+		.subdevice	= PCI_ANY_ID,
+		.probe		= pci_timedia_probe,
+		.init		= pci_timedia_init,
+		.setup		= pci_timedia_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_TIMEDIA,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_timedia_setup,
+	},
+	/*
+	 * Sunix PCI serial boards
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_SUNIX,
+		.device		= PCI_DEVICE_ID_SUNIX_1999,
+		.subvendor	= PCI_VENDOR_ID_SUNIX,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_sunix_setup,
+	},
+	/*
+	 * Xircom cards
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_XIRCOM,
+		.device		= PCI_DEVICE_ID_XIRCOM_X3201_MDM,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_xircom_init,
+		.setup		= pci_default_setup,
+	},
+	/*
+	 * Netmos cards - these may be called via parport_serial
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_NETMOS,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_netmos_init,
+		.setup		= pci_netmos_9900_setup,
+	},
+	/*
+	 * EndRun Technologies
+	*/
+	{
+		.vendor		= PCI_VENDOR_ID_ENDRUN,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_default_setup,
+	},
+	/*
+	 * For Oxford Semiconductor Tornado based devices
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_OXSEMI,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_MAINPINE,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_DIGI,
+		.device		= PCIE_DEVICE_ID_NEO_2_OX_IBM,
+		.subvendor		= PCI_SUBVENDOR_ID_IBM,
+		.subdevice		= PCI_ANY_ID,
+		.init			= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	/*
+	 * Brainboxes devices - all Oxsemi based
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4027,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4028,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4029,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4019,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4016,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4015,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x400A,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x400E,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x400C,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x400B,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x400F,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4010,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4011,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x401D,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x401E,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4013,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4017,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4018,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8811,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8812,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8813,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8814,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8027,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8028,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8029,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800C,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800D,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_eg20t_init,
+		.setup		= pci_default_setup,
+	},
+	/*
+	 * Cronyx Omega PCI (PLX-chip based)
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_PLX,
+		.device		= PCI_DEVICE_ID_PLX_CRONYX_OMEGA,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_omegapci_setup,
+	},
+	/* WCH CH353 1S1P card (16550 clone) */
+	{
+		.vendor         = PCI_VENDOR_ID_WCH,
+		.device         = PCI_DEVICE_ID_WCH_CH353_1S1P,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch353_setup,
+	},
+	/* WCH CH353 2S1P card (16550 clone) */
+	{
+		.vendor         = PCI_VENDOR_ID_WCH,
+		.device         = PCI_DEVICE_ID_WCH_CH353_2S1P,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch353_setup,
+	},
+	/* WCH CH353 4S card (16550 clone) */
+	{
+		.vendor         = PCI_VENDOR_ID_WCH,
+		.device         = PCI_DEVICE_ID_WCH_CH353_4S,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch353_setup,
+	},
+	/* WCH CH353 2S1PF card (16550 clone) */
+	{
+		.vendor         = PCI_VENDOR_ID_WCH,
+		.device         = PCI_DEVICE_ID_WCH_CH353_2S1PF,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch353_setup,
+	},
+	/* WCH CH352 2S card (16550 clone) */
+	{
+		.vendor		= PCI_VENDOR_ID_WCH,
+		.device		= PCI_DEVICE_ID_WCH_CH352_2S,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_wch_ch353_setup,
+	},
+	/* WCH CH355 4S card (16550 clone) */
+	{
+		.vendor		= PCI_VENDOR_ID_WCH,
+		.device		= PCI_DEVICE_ID_WCH_CH355_4S,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_wch_ch355_setup,
+	},
+	/* WCH CH382 2S card (16850 clone) */
+	{
+		.vendor         = PCIE_VENDOR_ID_WCH,
+		.device         = PCIE_DEVICE_ID_WCH_CH382_2S,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch38x_setup,
+	},
+	/* WCH CH382 2S1P card (16850 clone) */
+	{
+		.vendor         = PCIE_VENDOR_ID_WCH,
+		.device         = PCIE_DEVICE_ID_WCH_CH382_2S1P,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch38x_setup,
+	},
+	/* WCH CH384 4S card (16850 clone) */
+	{
+		.vendor         = PCIE_VENDOR_ID_WCH,
+		.device         = PCIE_DEVICE_ID_WCH_CH384_4S,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.setup          = pci_wch_ch38x_setup,
+	},
+	/* WCH CH384 8S card (16850 clone) */
+	{
+		.vendor         = PCIE_VENDOR_ID_WCH,
+		.device         = PCIE_DEVICE_ID_WCH_CH384_8S,
+		.subvendor      = PCI_ANY_ID,
+		.subdevice      = PCI_ANY_ID,
+		.init           = pci_wch_ch38x_init,
+		.exit		= pci_wch_ch38x_exit,
+		.setup          = pci_wch_ch38x_setup,
+	},
+	/*
+	 * Broadcom TruManage (NetXtreme)
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_BROADCOM,
+		.device		= PCI_DEVICE_ID_BROADCOM_TRUMANAGE,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_brcm_trumanage_setup,
+	},
+	{
+		.vendor		= 0x1c29,
+		.device		= 0x1104,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_fintek_setup,
+		.init		= pci_fintek_init,
+	},
+	{
+		.vendor		= 0x1c29,
+		.device		= 0x1108,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_fintek_setup,
+		.init		= pci_fintek_init,
+	},
+	{
+		.vendor		= 0x1c29,
+		.device		= 0x1112,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_fintek_setup,
+		.init		= pci_fintek_init,
+	},
+	/*
+	 * MOXA
+	 */
+	{
+		.vendor		= PCI_VENDOR_ID_MOXA,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_moxa_setup,
+	},
+	{
+		.vendor		= 0x1c29,
+		.device		= 0x1204,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_fintek_f815xxa_setup,
+		.init		= pci_fintek_f815xxa_init,
+	},
+	{
+		.vendor		= 0x1c29,
+		.device		= 0x1208,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_fintek_f815xxa_setup,
+		.init		= pci_fintek_f815xxa_init,
+	},
+	{
+		.vendor		= 0x1c29,
+		.device		= 0x1212,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_fintek_f815xxa_setup,
+		.init		= pci_fintek_f815xxa_init,
+	},
+
+	/*
+	 * Default "match everything" terminator entry
+	 */
+	{
+		.vendor		= PCI_ANY_ID,
+		.device		= PCI_ANY_ID,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_default_setup,
+	}
+};
+
+static inline int quirk_id_matches(u32 quirk_id, u32 dev_id)
+{
+	return quirk_id == PCI_ANY_ID || quirk_id == dev_id;
+}
+
+static struct pci_serial_quirk *find_quirk(struct pci_dev *dev)
+{
+	struct pci_serial_quirk *quirk;
+
+	for (quirk = pci_serial_quirks; ; quirk++)
+		if (quirk_id_matches(quirk->vendor, dev->vendor) &&
+		    quirk_id_matches(quirk->device, dev->device) &&
+		    quirk_id_matches(quirk->subvendor, dev->subsystem_vendor) &&
+		    quirk_id_matches(quirk->subdevice, dev->subsystem_device))
+			break;
+	return quirk;
+}
+
+/*
+ * This is the configuration table for all of the PCI serial boards
+ * which we support.  It is directly indexed by the pci_board_num_t enum
+ * value, which is encoded in the pci_device_id PCI probe table's
+ * driver_data member.
+ *
+ * The makeup of these names are:
+ *  pbn_bn{_bt}_n_baud{_offsetinhex}
+ *
+ *  bn		= PCI BAR number
+ *  bt		= Index using PCI BARs
+ *  n		= number of serial ports
+ *  baud	= baud rate
+ *  offsetinhex	= offset for each sequential port (in hex)
+ *
+ * This table is sorted by (in order): bn, bt, baud, offsetindex, n.
+ *
+ * Please note: in theory if n = 1, _bt infix should make no difference.
+ * ie, pbn_b0_1_115200 is the same as pbn_b0_bt_1_115200
+ */
+enum pci_board_num_t {
+	pbn_default = 0,
+
+	pbn_b0_1_115200,
+	pbn_b0_2_115200,
+	pbn_b0_4_115200,
+	pbn_b0_5_115200,
+	pbn_b0_8_115200,
+
+	pbn_b0_1_921600,
+	pbn_b0_2_921600,
+	pbn_b0_4_921600,
+
+	pbn_b0_2_1130000,
+
+	pbn_b0_4_1152000,
+
+	pbn_b0_4_1250000,
+
+	pbn_b0_2_1843200,
+	pbn_b0_4_1843200,
+
+	pbn_b0_1_15625000,
+
+	pbn_b0_bt_1_115200,
+	pbn_b0_bt_2_115200,
+	pbn_b0_bt_4_115200,
+	pbn_b0_bt_8_115200,
+
+	pbn_b0_bt_1_460800,
+	pbn_b0_bt_2_460800,
+	pbn_b0_bt_4_460800,
+
+	pbn_b0_bt_1_921600,
+	pbn_b0_bt_2_921600,
+	pbn_b0_bt_4_921600,
+	pbn_b0_bt_8_921600,
+
+	pbn_b1_1_115200,
+	pbn_b1_2_115200,
+	pbn_b1_4_115200,
+	pbn_b1_8_115200,
+	pbn_b1_16_115200,
+
+	pbn_b1_1_921600,
+	pbn_b1_2_921600,
+	pbn_b1_4_921600,
+	pbn_b1_8_921600,
+
+	pbn_b1_2_1250000,
+
+	pbn_b1_bt_1_115200,
+	pbn_b1_bt_2_115200,
+	pbn_b1_bt_4_115200,
+
+	pbn_b1_bt_2_921600,
+
+	pbn_b1_1_1382400,
+	pbn_b1_2_1382400,
+	pbn_b1_4_1382400,
+	pbn_b1_8_1382400,
+
+	pbn_b2_1_115200,
+	pbn_b2_2_115200,
+	pbn_b2_4_115200,
+	pbn_b2_8_115200,
+
+	pbn_b2_1_460800,
+	pbn_b2_4_460800,
+	pbn_b2_8_460800,
+	pbn_b2_16_460800,
+
+	pbn_b2_1_921600,
+	pbn_b2_4_921600,
+	pbn_b2_8_921600,
+
+	pbn_b2_8_1152000,
+
+	pbn_b2_bt_1_115200,
+	pbn_b2_bt_2_115200,
+	pbn_b2_bt_4_115200,
+
+	pbn_b2_bt_2_921600,
+	pbn_b2_bt_4_921600,
+
+	pbn_b3_2_115200,
+	pbn_b3_4_115200,
+	pbn_b3_8_115200,
+
+	pbn_b4_bt_2_921600,
+	pbn_b4_bt_4_921600,
+	pbn_b4_bt_8_921600,
+
+	/*
+	 * Board-specific versions.
+	 */
+	pbn_panacom,
+	pbn_panacom2,
+	pbn_panacom4,
+	pbn_plx_romulus,
+	pbn_oxsemi,
+	pbn_oxsemi_1_15625000,
+	pbn_oxsemi_2_15625000,
+	pbn_oxsemi_4_15625000,
+	pbn_oxsemi_8_15625000,
+	pbn_intel_i960,
+	pbn_sgi_ioc3,
+	pbn_computone_4,
+	pbn_computone_6,
+	pbn_computone_8,
+	pbn_sbsxrsio,
+	pbn_pasemi_1682M,
+	pbn_ni8430_2,
+	pbn_ni8430_4,
+	pbn_ni8430_8,
+	pbn_ni8430_16,
+	pbn_ADDIDATA_PCIe_1_3906250,
+	pbn_ADDIDATA_PCIe_2_3906250,
+	pbn_ADDIDATA_PCIe_4_3906250,
+	pbn_ADDIDATA_PCIe_8_3906250,
+	pbn_ce4100_1_115200,
+	pbn_omegapci,
+	pbn_NETMOS9900_2s_115200,
+	pbn_brcm_trumanage,
+	pbn_fintek_4,
+	pbn_fintek_8,
+	pbn_fintek_12,
+	pbn_fintek_F81504A,
+	pbn_fintek_F81508A,
+	pbn_fintek_F81512A,
+	pbn_wch382_2,
+	pbn_wch384_4,
+	pbn_wch384_8,
+	pbn_sunix_pci_1s,
+	pbn_sunix_pci_2s,
+	pbn_sunix_pci_4s,
+	pbn_sunix_pci_8s,
+	pbn_sunix_pci_16s,
+	pbn_titan_1_4000000,
+	pbn_titan_2_4000000,
+	pbn_titan_4_4000000,
+	pbn_titan_8_4000000,
+	pbn_moxa8250_2p,
+	pbn_moxa8250_4p,
+	pbn_moxa8250_8p,
+};
+
+/*
+ * uart_offset - the space between channels
+ * reg_shift   - describes how the UART registers are mapped
+ *               to PCI memory by the card.
+ * For example IER register on SBS, Inc. PMC-OctPro is located at
+ * offset 0x10 from the UART base, while UART_IER is defined as 1
+ * in include/linux/serial_reg.h,
+ * see first lines of serial_in() and serial_out() in 8250.c
+*/
+
+static struct pciserial_board pci_boards[] = {
+	[pbn_default] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_1_115200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_2_115200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_4_115200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_5_115200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 5,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_8_115200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_1_921600] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_2_921600] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_4_921600] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_2_1130000] = {
+		.flags          = FL_BASE0,
+		.num_ports      = 2,
+		.base_baud      = 1130000,
+		.uart_offset    = 8,
+	},
+
+	[pbn_b0_4_1152000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 1152000,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_4_1250000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 1250000,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_2_1843200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 1843200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_4_1843200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 1843200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_1_15625000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 15625000,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_bt_1_115200] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_2_115200] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_4_115200] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_8_115200] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 8,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_bt_1_460800] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 1,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_2_460800] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_4_460800] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b0_bt_1_921600] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 1,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_2_921600] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_4_921600] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b0_bt_8_921600] = {
+		.flags		= FL_BASE0|FL_BASE_BARS,
+		.num_ports	= 8,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b1_1_115200] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_2_115200] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_4_115200] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 4,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_8_115200] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 8,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_16_115200] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 16,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b1_1_921600] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 1,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_2_921600] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_4_921600] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_8_921600] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 8,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_2_1250000] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 2,
+		.base_baud	= 1250000,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b1_bt_1_115200] = {
+		.flags		= FL_BASE1|FL_BASE_BARS,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_bt_2_115200] = {
+		.flags		= FL_BASE1|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_bt_4_115200] = {
+		.flags		= FL_BASE1|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b1_bt_2_921600] = {
+		.flags		= FL_BASE1|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b1_1_1382400] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 1,
+		.base_baud	= 1382400,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_2_1382400] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 2,
+		.base_baud	= 1382400,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_4_1382400] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 4,
+		.base_baud	= 1382400,
+		.uart_offset	= 8,
+	},
+	[pbn_b1_8_1382400] = {
+		.flags		= FL_BASE1,
+		.num_ports	= 8,
+		.base_baud	= 1382400,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b2_1_115200] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_2_115200] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_4_115200] = {
+		.flags          = FL_BASE2,
+		.num_ports      = 4,
+		.base_baud      = 115200,
+		.uart_offset    = 8,
+	},
+	[pbn_b2_8_115200] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 8,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b2_1_460800] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 1,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_4_460800] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 4,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_8_460800] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 8,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_16_460800] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 16,
+		.base_baud	= 460800,
+		.uart_offset	= 8,
+	 },
+
+	[pbn_b2_1_921600] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 1,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_4_921600] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_8_921600] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 8,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b2_8_1152000] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 8,
+		.base_baud	= 1152000,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b2_bt_1_115200] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 1,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_bt_2_115200] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_bt_4_115200] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b2_bt_2_921600] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b2_bt_4_921600] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b3_2_115200] = {
+		.flags		= FL_BASE3,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b3_4_115200] = {
+		.flags		= FL_BASE3,
+		.num_ports	= 4,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_b3_8_115200] = {
+		.flags		= FL_BASE3,
+		.num_ports	= 8,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+
+	[pbn_b4_bt_2_921600] = {
+		.flags		= FL_BASE4,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b4_bt_4_921600] = {
+		.flags		= FL_BASE4,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+	[pbn_b4_bt_8_921600] = {
+		.flags		= FL_BASE4,
+		.num_ports	= 8,
+		.base_baud	= 921600,
+		.uart_offset	= 8,
+	},
+
+	/*
+	 * Entries following this are board-specific.
+	 */
+
+	/*
+	 * Panacom - IOMEM
+	 */
+	[pbn_panacom] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 0x400,
+		.reg_shift	= 7,
+	},
+	[pbn_panacom2] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.uart_offset	= 0x400,
+		.reg_shift	= 7,
+	},
+	[pbn_panacom4] = {
+		.flags		= FL_BASE2|FL_BASE_BARS,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 0x400,
+		.reg_shift	= 7,
+	},
+
+	/* I think this entry is broken - the first_offset looks wrong --rmk */
+	[pbn_plx_romulus] = {
+		.flags		= FL_BASE2,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 8 << 2,
+		.reg_shift	= 2,
+		.first_offset	= 0x03,
+	},
+
+	/*
+	 * This board uses the size of PCI Base region 0 to
+	 * signal now many ports are available
+	 */
+	[pbn_oxsemi] = {
+		.flags		= FL_BASE0|FL_REGION_SZ_CAP,
+		.num_ports	= 32,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+	},
+	[pbn_oxsemi_1_15625000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 15625000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_oxsemi_2_15625000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 15625000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_oxsemi_4_15625000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 15625000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_oxsemi_8_15625000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 15625000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+
+
+	/*
+	 * EKF addition for i960 Boards form EKF with serial port.
+	 * Max 256 ports.
+	 */
+	[pbn_intel_i960] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 32,
+		.base_baud	= 921600,
+		.uart_offset	= 8 << 2,
+		.reg_shift	= 2,
+		.first_offset	= 0x10000,
+	},
+	[pbn_sgi_ioc3] = {
+		.flags		= FL_BASE0|FL_NOIRQ,
+		.num_ports	= 1,
+		.base_baud	= 458333,
+		.uart_offset	= 8,
+		.reg_shift	= 0,
+		.first_offset	= 0x20178,
+	},
+
+	/*
+	 * Computone - uses IOMEM.
+	 */
+	[pbn_computone_4] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 921600,
+		.uart_offset	= 0x40,
+		.reg_shift	= 2,
+		.first_offset	= 0x200,
+	},
+	[pbn_computone_6] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 6,
+		.base_baud	= 921600,
+		.uart_offset	= 0x40,
+		.reg_shift	= 2,
+		.first_offset	= 0x200,
+	},
+	[pbn_computone_8] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 921600,
+		.uart_offset	= 0x40,
+		.reg_shift	= 2,
+		.first_offset	= 0x200,
+	},
+	[pbn_sbsxrsio] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 460800,
+		.uart_offset	= 256,
+		.reg_shift	= 4,
+	},
+	/*
+	 * PA Semi PWRficient PA6T-1682M on-chip UART
+	 */
+	[pbn_pasemi_1682M] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 8333333,
+	},
+	/*
+	 * National Instruments 843x
+	 */
+	[pbn_ni8430_16] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 16,
+		.base_baud	= 3686400,
+		.uart_offset	= 0x10,
+		.first_offset	= 0x800,
+	},
+	[pbn_ni8430_8] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 3686400,
+		.uart_offset	= 0x10,
+		.first_offset	= 0x800,
+	},
+	[pbn_ni8430_4] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 3686400,
+		.uart_offset	= 0x10,
+		.first_offset	= 0x800,
+	},
+	[pbn_ni8430_2] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 3686400,
+		.uart_offset	= 0x10,
+		.first_offset	= 0x800,
+	},
+	/*
+	 * ADDI-DATA GmbH PCI-Express communication cards <info@addi-data.com>
+	 */
+	[pbn_ADDIDATA_PCIe_1_3906250] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 3906250,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_ADDIDATA_PCIe_2_3906250] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 3906250,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_ADDIDATA_PCIe_4_3906250] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 3906250,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_ADDIDATA_PCIe_8_3906250] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 3906250,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_ce4100_1_115200] = {
+		.flags		= FL_BASE_BARS,
+		.num_ports	= 2,
+		.base_baud	= 921600,
+		.reg_shift      = 2,
+	},
+	[pbn_omegapci] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 115200,
+		.uart_offset	= 0x200,
+	},
+	[pbn_NETMOS9900_2s_115200] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+	},
+	[pbn_brcm_trumanage] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.reg_shift	= 2,
+		.base_baud	= 115200,
+	},
+	[pbn_fintek_4] = {
+		.num_ports	= 4,
+		.uart_offset	= 8,
+		.base_baud	= 115200,
+		.first_offset	= 0x40,
+	},
+	[pbn_fintek_8] = {
+		.num_ports	= 8,
+		.uart_offset	= 8,
+		.base_baud	= 115200,
+		.first_offset	= 0x40,
+	},
+	[pbn_fintek_12] = {
+		.num_ports	= 12,
+		.uart_offset	= 8,
+		.base_baud	= 115200,
+		.first_offset	= 0x40,
+	},
+	[pbn_fintek_F81504A] = {
+		.num_ports	= 4,
+		.uart_offset	= 8,
+		.base_baud	= 115200,
+	},
+	[pbn_fintek_F81508A] = {
+		.num_ports	= 8,
+		.uart_offset	= 8,
+		.base_baud	= 115200,
+	},
+	[pbn_fintek_F81512A] = {
+		.num_ports	= 12,
+		.uart_offset	= 8,
+		.base_baud	= 115200,
+	},
+	[pbn_wch382_2] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 115200,
+		.uart_offset	= 8,
+		.first_offset	= 0xC0,
+	},
+	[pbn_wch384_4] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud      = 115200,
+		.uart_offset    = 8,
+		.first_offset   = 0xC0,
+	},
+	[pbn_wch384_8] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud      = 115200,
+		.uart_offset    = 8,
+		.first_offset   = 0x00,
+	},
+	[pbn_sunix_pci_1s] = {
+		.num_ports	= 1,
+		.base_baud      = 921600,
+		.uart_offset	= 0x8,
+	},
+	[pbn_sunix_pci_2s] = {
+		.num_ports	= 2,
+		.base_baud      = 921600,
+		.uart_offset	= 0x8,
+	},
+	[pbn_sunix_pci_4s] = {
+		.num_ports	= 4,
+		.base_baud      = 921600,
+		.uart_offset	= 0x8,
+	},
+	[pbn_sunix_pci_8s] = {
+		.num_ports	= 8,
+		.base_baud      = 921600,
+		.uart_offset	= 0x8,
+	},
+	[pbn_sunix_pci_16s] = {
+		.num_ports	= 16,
+		.base_baud      = 921600,
+		.uart_offset	= 0x8,
+	},
+	[pbn_titan_1_4000000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 1,
+		.base_baud	= 4000000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_titan_2_4000000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 2,
+		.base_baud	= 4000000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_titan_4_4000000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 4,
+		.base_baud	= 4000000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_titan_8_4000000] = {
+		.flags		= FL_BASE0,
+		.num_ports	= 8,
+		.base_baud	= 4000000,
+		.uart_offset	= 0x200,
+		.first_offset	= 0x1000,
+	},
+	[pbn_moxa8250_2p] = {
+		.flags		= FL_BASE1,
+		.num_ports      = 2,
+		.base_baud      = 921600,
+		.uart_offset	= 0x200,
+	},
+	[pbn_moxa8250_4p] = {
+		.flags		= FL_BASE1,
+		.num_ports      = 4,
+		.base_baud      = 921600,
+		.uart_offset	= 0x200,
+	},
+	[pbn_moxa8250_8p] = {
+		.flags		= FL_BASE1,
+		.num_ports      = 8,
+		.base_baud      = 921600,
+		.uart_offset	= 0x200,
+	},
+};
+
+#define REPORT_CONFIG(option) \
+	(IS_ENABLED(CONFIG_##option) ? 0 : (kernel_ulong_t)&#option)
+#define REPORT_8250_CONFIG(option) \
+	(IS_ENABLED(CONFIG_SERIAL_8250_##option) ? \
+	 0 : (kernel_ulong_t)&"SERIAL_8250_"#option)
+
+static const struct pci_device_id blacklist[] = {
+	/* softmodems */
+	{ PCI_VDEVICE(AL, 0x5457), }, /* ALi Corporation M5457 AC'97 Modem */
+	{ PCI_VDEVICE(MOTOROLA, 0x3052), }, /* Motorola Si3052-based modem */
+	{ PCI_DEVICE(0x1543, 0x3052), }, /* Si3052-based modem, default IDs */
+
+	/* multi-io cards handled by parport_serial */
+	/* WCH CH353 2S1P */
+	{ PCI_DEVICE(0x4348, 0x7053), 0, 0, REPORT_CONFIG(PARPORT_SERIAL), },
+	/* WCH CH353 1S1P */
+	{ PCI_DEVICE(0x4348, 0x5053), 0, 0, REPORT_CONFIG(PARPORT_SERIAL), },
+	/* WCH CH382 2S1P */
+	{ PCI_DEVICE(0x1c00, 0x3250), 0, 0, REPORT_CONFIG(PARPORT_SERIAL), },
+
+	/* Intel platforms with MID UART */
+	{ PCI_VDEVICE(INTEL, 0x081b), REPORT_8250_CONFIG(MID), },
+	{ PCI_VDEVICE(INTEL, 0x081c), REPORT_8250_CONFIG(MID), },
+	{ PCI_VDEVICE(INTEL, 0x081d), REPORT_8250_CONFIG(MID), },
+	{ PCI_VDEVICE(INTEL, 0x1191), REPORT_8250_CONFIG(MID), },
+	{ PCI_VDEVICE(INTEL, 0x18d8), REPORT_8250_CONFIG(MID), },
+	{ PCI_VDEVICE(INTEL, 0x19d8), REPORT_8250_CONFIG(MID), },
+
+	/* Intel platforms with DesignWare UART */
+	{ PCI_VDEVICE(INTEL, 0x0936), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x0f0a), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x0f0c), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x228a), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x228c), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x4b96), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x4b97), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x4b98), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x4b99), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x4b9a), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x4b9b), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x9ce3), REPORT_8250_CONFIG(LPSS), },
+	{ PCI_VDEVICE(INTEL, 0x9ce4), REPORT_8250_CONFIG(LPSS), },
+
+	/* Exar devices */
+	{ PCI_VDEVICE(EXAR, PCI_ANY_ID), REPORT_8250_CONFIG(EXAR), },
+	{ PCI_VDEVICE(COMMTECH, PCI_ANY_ID), REPORT_8250_CONFIG(EXAR), },
+
+	/* Pericom devices */
+	{ PCI_VDEVICE(PERICOM, PCI_ANY_ID), REPORT_8250_CONFIG(PERICOM), },
+	{ PCI_VDEVICE(ACCESSIO, PCI_ANY_ID), REPORT_8250_CONFIG(PERICOM), },
+
+	/* End of the black list */
+	{ }
+};
+
+static int serial_pci_is_class_communication(struct pci_dev *dev)
+{
+	/*
+	 * If it is not a communications device or the programming
+	 * interface is greater than 6, give up.
+	 */
+	if ((((dev->class >> 8) != PCI_CLASS_COMMUNICATION_SERIAL) &&
+	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MULTISERIAL) &&
+	     ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MODEM)) ||
+	    (dev->class & 0xff) > 6)
+		return -ENODEV;
+
+	return 0;
+}
+
+/*
+ * Given a complete unknown PCI device, try to use some heuristics to
+ * guess what the configuration might be, based on the pitiful PCI
+ * serial specs.  Returns 0 on success, -ENODEV on failure.
+ */
+static int
+serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
+{
+	int num_iomem, num_port, first_port = -1, i;
+	int rc;
+
+	rc = serial_pci_is_class_communication(dev);
+	if (rc)
+		return rc;
+
+	/*
+	 * Should we try to make guesses for multiport serial devices later?
+	 */
+	if ((dev->class >> 8) == PCI_CLASS_COMMUNICATION_MULTISERIAL)
+		return -ENODEV;
+
+	num_iomem = num_port = 0;
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
+		if (pci_resource_flags(dev, i) & IORESOURCE_IO) {
+			num_port++;
+			if (first_port == -1)
+				first_port = i;
+		}
+		if (pci_resource_flags(dev, i) & IORESOURCE_MEM)
+			num_iomem++;
+	}
+
+	/*
+	 * If there is 1 or 0 iomem regions, and exactly one port,
+	 * use it.  We guess the number of ports based on the IO
+	 * region size.
+	 */
+	if (num_iomem <= 1 && num_port == 1) {
+		board->flags = first_port;
+		board->num_ports = pci_resource_len(dev, first_port) / 8;
+		return 0;
+	}
+
+	/*
+	 * Now guess if we've got a board which indexes by BARs.
+	 * Each IO BAR should be 8 bytes, and they should follow
+	 * consecutively.
+	 */
+	first_port = -1;
+	num_port = 0;
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
+		if (pci_resource_flags(dev, i) & IORESOURCE_IO &&
+		    pci_resource_len(dev, i) == 8 &&
+		    (first_port == -1 || (first_port + num_port) == i)) {
+			num_port++;
+			if (first_port == -1)
+				first_port = i;
+		}
+	}
+
+	if (num_port > 1) {
+		board->flags = first_port | FL_BASE_BARS;
+		board->num_ports = num_port;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static inline int
+serial_pci_matches(const struct pciserial_board *board,
+		   const struct pciserial_board *guessed)
+{
+	return
+	    board->num_ports == guessed->num_ports &&
+	    board->base_baud == guessed->base_baud &&
+	    board->uart_offset == guessed->uart_offset &&
+	    board->reg_shift == guessed->reg_shift &&
+	    board->first_offset == guessed->first_offset;
+}
+
+struct serial_private *
+pciserial_init_ports(struct pci_dev *dev, const struct pciserial_board *board)
+{
+	struct uart_8250_port uart;
+	struct serial_private *priv;
+	struct pci_serial_quirk *quirk;
+	int rc, nr_ports, i;
+
+	nr_ports = board->num_ports;
+
+	/*
+	 * Find an init and setup quirks.
+	 */
+	quirk = find_quirk(dev);
+
+	/*
+	 * Run the new-style initialization function.
+	 * The initialization function returns:
+	 *  <0  - error
+	 *   0  - use board->num_ports
+	 *  >0  - number of ports
+	 */
+	if (quirk->init) {
+		rc = quirk->init(dev);
+		if (rc < 0) {
+			priv = ERR_PTR(rc);
+			goto err_out;
+		}
+		if (rc)
+			nr_ports = rc;
+	}
+
+	priv = kzalloc(struct_size(priv, line, nr_ports), GFP_KERNEL);
+	if (!priv) {
+		priv = ERR_PTR(-ENOMEM);
+		goto err_deinit;
+	}
+
+	priv->dev = dev;
+	priv->quirk = quirk;
+
+	memset(&uart, 0, sizeof(uart));
+	uart.port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ;
+	uart.port.uartclk = board->base_baud * 16;
+
+	if (board->flags & FL_NOIRQ) {
+		uart.port.irq = 0;
+	} else {
+		if (pci_match_id(pci_use_msi, dev)) {
+			pci_dbg(dev, "Using MSI(-X) interrupts\n");
+			pci_set_master(dev);
+			uart.port.flags &= ~UPF_SHARE_IRQ;
+			rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_ALL_TYPES);
+		} else {
+			pci_dbg(dev, "Using legacy interrupts\n");
+			rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
+		}
+		if (rc < 0) {
+			kfree(priv);
+			priv = ERR_PTR(rc);
+			goto err_deinit;
+		}
+
+		uart.port.irq = pci_irq_vector(dev, 0);
+	}
+
+	uart.port.dev = &dev->dev;
+
+	for (i = 0; i < nr_ports; i++) {
+		if (quirk->setup(priv, board, &uart, i))
+			break;
+
+		pci_dbg(dev, "Setup PCI port: port %lx, irq %d, type %d\n",
+			uart.port.iobase, uart.port.irq, uart.port.iotype);
+
+		priv->line[i] = serial8250_register_8250_port(&uart);
+		if (priv->line[i] < 0) {
+			pci_err(dev,
+				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
+				uart.port.iobase, uart.port.irq,
+				uart.port.iotype, priv->line[i]);
+			break;
+		}
+	}
+	priv->nr = i;
+	priv->board = board;
+	return priv;
+
+err_deinit:
+	if (quirk->exit)
+		quirk->exit(dev);
+err_out:
+	return priv;
+}
+EXPORT_SYMBOL_GPL(pciserial_init_ports);
+
+static void pciserial_detach_ports(struct serial_private *priv)
+{
+	struct pci_serial_quirk *quirk;
+	int i;
+
+	for (i = 0; i < priv->nr; i++)
+		serial8250_unregister_port(priv->line[i]);
+
+	/*
+	 * Find the exit quirks.
+	 */
+	quirk = find_quirk(priv->dev);
+	if (quirk->exit)
+		quirk->exit(priv->dev);
+}
+
+void pciserial_remove_ports(struct serial_private *priv)
+{
+	pciserial_detach_ports(priv);
+	kfree(priv);
+}
+EXPORT_SYMBOL_GPL(pciserial_remove_ports);
+
+void pciserial_suspend_ports(struct serial_private *priv)
+{
+	int i;
+
+	for (i = 0; i < priv->nr; i++)
+		if (priv->line[i] >= 0)
+			serial8250_suspend_port(priv->line[i]);
+
+	/*
+	 * Ensure that every init quirk is properly torn down
+	 */
+	if (priv->quirk->exit)
+		priv->quirk->exit(priv->dev);
+}
+EXPORT_SYMBOL_GPL(pciserial_suspend_ports);
+
+void pciserial_resume_ports(struct serial_private *priv)
+{
+	int i;
+
+	/*
+	 * Ensure that the board is correctly configured.
+	 */
+	if (priv->quirk->init)
+		priv->quirk->init(priv->dev);
+
+	for (i = 0; i < priv->nr; i++)
+		if (priv->line[i] >= 0)
+			serial8250_resume_port(priv->line[i]);
+}
+EXPORT_SYMBOL_GPL(pciserial_resume_ports);
+
+/*
+ * Probe one serial board.  Unfortunately, there is no rhyme nor reason
+ * to the arrangement of serial ports on a PCI card.
+ */
+static int
+pciserial_init_one(struct pci_dev *dev, const struct pci_device_id *ent)
+{
+	struct pci_serial_quirk *quirk;
+	struct serial_private *priv;
+	const struct pciserial_board *board;
+	const struct pci_device_id *exclude;
+	struct pciserial_board tmp;
+	int rc;
+
+	quirk = find_quirk(dev);
+	if (quirk->probe) {
+		rc = quirk->probe(dev);
+		if (rc)
+			return rc;
+	}
+
+	if (ent->driver_data >= ARRAY_SIZE(pci_boards)) {
+		pci_err(dev, "invalid driver_data: %ld\n", ent->driver_data);
+		return -EINVAL;
+	}
+
+	board = &pci_boards[ent->driver_data];
+
+	exclude = pci_match_id(blacklist, dev);
+	if (exclude) {
+		if (exclude->driver_data)
+			pci_warn(dev, "ignoring port, enable %s to handle\n",
+				 (const char *)exclude->driver_data);
+		return -ENODEV;
+	}
+
+	rc = pcim_enable_device(dev);
+	pci_save_state(dev);
+	if (rc)
+		return rc;
+
+	if (ent->driver_data == pbn_default) {
+		/*
+		 * Use a copy of the pci_board entry for this;
+		 * avoid changing entries in the table.
+		 */
+		memcpy(&tmp, board, sizeof(struct pciserial_board));
+		board = &tmp;
+
+		/*
+		 * We matched one of our class entries.  Try to
+		 * determine the parameters of this board.
+		 */
+		rc = serial_pci_guess_board(dev, &tmp);
+		if (rc)
+			return rc;
+	} else {
+		/*
+		 * We matched an explicit entry.  If we are able to
+		 * detect this boards settings with our heuristic,
+		 * then we no longer need this entry.
+		 */
+		memcpy(&tmp, &pci_boards[pbn_default],
+		       sizeof(struct pciserial_board));
+		rc = serial_pci_guess_board(dev, &tmp);
+		if (rc == 0 && serial_pci_matches(board, &tmp))
+			moan_device("Redundant entry in serial pci_table.",
+				    dev);
+	}
+
+	priv = pciserial_init_ports(dev, board);
+	if (IS_ERR(priv))
+		return PTR_ERR(priv);
+
+	pci_set_drvdata(dev, priv);
+	return 0;
+}
+
+static void pciserial_remove_one(struct pci_dev *dev)
+{
+	struct serial_private *priv = pci_get_drvdata(dev);
+
+	pciserial_remove_ports(priv);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pciserial_suspend_one(struct device *dev)
+{
+	struct serial_private *priv = dev_get_drvdata(dev);
+
+	if (priv)
+		pciserial_suspend_ports(priv);
+
+	return 0;
+}
+
+static int pciserial_resume_one(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct serial_private *priv = pci_get_drvdata(pdev);
+	int err;
+
+	if (priv) {
+		/*
+		 * The device may have been disabled.  Re-enable it.
+		 */
+		err = pci_enable_device(pdev);
+		/* FIXME: We cannot simply error out here */
+		if (err)
+			pci_err(pdev, "Unable to re-enable ports, trying to continue.\n");
+		pciserial_resume_ports(priv);
+	}
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pciserial_pm_ops, pciserial_suspend_one,
+			 pciserial_resume_one);
+
+static const struct pci_device_id serial_pci_tbl[] = {
+	{	PCI_VENDOR_ID_ADVANTECH, PCI_DEVICE_ID_ADVANTECH_PCI1600,
+		PCI_DEVICE_ID_ADVANTECH_PCI1600_1611, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	/* Advantech use PCI_DEVICE_ID_ADVANTECH_PCI3620 (0x3620) as 'PCI_SUBVENDOR_ID' */
+	{	PCI_VENDOR_ID_ADVANTECH, PCI_DEVICE_ID_ADVANTECH_PCI3620,
+		PCI_DEVICE_ID_ADVANTECH_PCI3620, 0x0001, 0, 0,
+		pbn_b2_8_921600 },
+	/* Advantech also use 0x3618 and 0xf618 */
+	{	PCI_VENDOR_ID_ADVANTECH, PCI_DEVICE_ID_ADVANTECH_PCI3618,
+		PCI_DEVICE_ID_ADVANTECH_PCI3618, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_ADVANTECH, PCI_DEVICE_ID_ADVANTECH_PCIf618,
+		PCI_DEVICE_ID_ADVANTECH_PCI3618, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V960,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH8_232, 0, 0,
+		pbn_b1_8_1382400 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V960,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH4_232, 0, 0,
+		pbn_b1_4_1382400 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V960,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH2_232, 0, 0,
+		pbn_b1_2_1382400 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH8_232, 0, 0,
+		pbn_b1_8_1382400 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH4_232, 0, 0,
+		pbn_b1_4_1382400 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH2_232, 0, 0,
+		pbn_b1_2_1382400 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH8_485, 0, 0,
+		pbn_b1_8_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH8_485_4_4, 0, 0,
+		pbn_b1_8_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH4_485, 0, 0,
+		pbn_b1_4_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH4_485_2_2, 0, 0,
+		pbn_b1_4_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH2_485, 0, 0,
+		pbn_b1_2_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH8_485_2_6, 0, 0,
+		pbn_b1_8_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH081101V1, 0, 0,
+		pbn_b1_8_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH041101V1, 0, 0,
+		pbn_b1_4_921600 },
+	{	PCI_VENDOR_ID_V3, PCI_DEVICE_ID_V3_V351,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_BH2_20MHZ, 0, 0,
+		pbn_b1_2_1250000 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI954,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_TITAN_2, 0, 0,
+		pbn_b0_2_1843200 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI954,
+		PCI_SUBVENDOR_ID_CONNECT_TECH,
+		PCI_SUBDEVICE_ID_CONNECT_TECH_TITAN_4, 0, 0,
+		pbn_b0_4_1843200 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI954,
+		PCI_VENDOR_ID_AFAVLAB,
+		PCI_SUBDEVICE_ID_AFAVLAB_P061, 0, 0,
+		pbn_b0_4_1152000 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_U530,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_1_115200 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_UCOMM2,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_115200 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_UCOMM422,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_4_115200 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_UCOMM232,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_115200 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_COMM4,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_4_115200 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_COMM8,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_8_115200 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_7803,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_8_460800 },
+	{	PCI_VENDOR_ID_SEALEVEL, PCI_DEVICE_ID_SEALEVEL_UCOMM8,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_8_115200 },
+
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_GTEK_SERIAL2,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_115200 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_SPCOM200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_921600 },
+	/*
+	 * VScom SPCOM800, from sl@s.pl
+	 */
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_SPCOM800,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_8_921600 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_1077,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_4_921600 },
+	/* Unknown card - subdevice 0x1584 */
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_VENDOR_ID_PLX,
+		PCI_SUBDEVICE_ID_UNKNOWN_0x1584, 0, 0,
+		pbn_b2_4_115200 },
+	/* Unknown card - subdevice 0x1588 */
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_VENDOR_ID_PLX,
+		PCI_SUBDEVICE_ID_UNKNOWN_0x1588, 0, 0,
+		pbn_b2_8_115200 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_KEYSPAN,
+		PCI_SUBDEVICE_ID_KEYSPAN_SX2, 0, 0,
+		pbn_panacom },
+	{	PCI_VENDOR_ID_PANACOM, PCI_DEVICE_ID_PANACOM_QUADMODEM,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_panacom4 },
+	{	PCI_VENDOR_ID_PANACOM, PCI_DEVICE_ID_PANACOM_DUALMODEM,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_panacom2 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030,
+		PCI_VENDOR_ID_ESDGMBH,
+		PCI_DEVICE_ID_ESDGMBH_CPCIASIO4, 0, 0,
+		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_CHASE_PCIFAST,
+		PCI_SUBDEVICE_ID_CHASE_PCIFAST4, 0, 0,
+		pbn_b2_4_460800 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_CHASE_PCIFAST,
+		PCI_SUBDEVICE_ID_CHASE_PCIFAST8, 0, 0,
+		pbn_b2_8_460800 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_CHASE_PCIFAST,
+		PCI_SUBDEVICE_ID_CHASE_PCIFAST16, 0, 0,
+		pbn_b2_16_460800 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_CHASE_PCIFAST,
+		PCI_SUBDEVICE_ID_CHASE_PCIFAST16FMC, 0, 0,
+		pbn_b2_16_460800 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_CHASE_PCIRAS,
+		PCI_SUBDEVICE_ID_CHASE_PCIRAS4, 0, 0,
+		pbn_b2_4_460800 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_CHASE_PCIRAS,
+		PCI_SUBDEVICE_ID_CHASE_PCIRAS8, 0, 0,
+		pbn_b2_8_460800 },
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+		PCI_SUBVENDOR_ID_EXSYS,
+		PCI_SUBDEVICE_ID_EXSYS_4055, 0, 0,
+		pbn_b2_4_115200 },
+	/*
+	 * Megawolf Romulus PCI Serial Card, from Mike Hudson
+	 * (Exoray@isys.ca)
+	 */
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_ROMULUS,
+		0x10b5, 0x106a, 0, 0,
+		pbn_plx_romulus },
+	/*
+	 * Quatech cards. These actually have configurable clocks but for
+	 * now we just use the default.
+	 *
+	 * 100 series are RS232, 200 series RS422,
+	 */
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_QSC100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_4_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSC100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSC100E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSC200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSC200E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_QSC200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_4_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_ESC100D,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_8_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_ESC100M,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_8_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_QSCP100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_4_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSCP100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_QSCP200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_4_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSCP200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_QSCLP100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSCLP100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_SSCLP100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_QSCLP200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_DSCLP200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_SSCLP200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_115200 },
+	{	PCI_VENDOR_ID_QUATECH, PCI_DEVICE_ID_QUATECH_ESCLP100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_8_115200 },
+
+	{	PCI_VENDOR_ID_SPECIALIX, PCI_DEVICE_ID_OXSEMI_16PCI954,
+		PCI_VENDOR_ID_SPECIALIX, PCI_SUBDEVICE_ID_SPECIALIX_SPEED4,
+		0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI954,
+		PCI_SUBVENDOR_ID_SIIG, PCI_SUBDEVICE_ID_SIIG_QUARTET_SERIAL,
+		0, 0,
+		pbn_b0_4_1152000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0x9505,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_921600 },
+
+		/*
+		 * The below card is a little controversial since it is the
+		 * subject of a PCI vendor/device ID clash.  (See
+		 * www.ussg.iu.edu/hypermail/linux/kernel/0303.1/0516.html).
+		 * For now just used the hex ID 0x950a.
+		 */
+	{	PCI_VENDOR_ID_OXSEMI, 0x950a,
+		PCI_SUBVENDOR_ID_SIIG, PCI_SUBDEVICE_ID_SIIG_DUAL_00,
+		0, 0, pbn_b0_2_115200 },
+	{	PCI_VENDOR_ID_OXSEMI, 0x950a,
+		PCI_SUBVENDOR_ID_SIIG, PCI_SUBDEVICE_ID_SIIG_DUAL_30,
+		0, 0, pbn_b0_2_115200 },
+	{	PCI_VENDOR_ID_OXSEMI, 0x950a,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_2_1130000 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_C950,
+		PCI_VENDOR_ID_OXSEMI, PCI_SUBDEVICE_ID_OXSEMI_C950, 0, 0,
+		pbn_b0_1_921600 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI954,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_115200 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI952,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_921600 },
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI958,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_8_1152000 },
+
+	/*
+	 * Oxford Semiconductor Inc. Tornado PCI express device range.
+	 */
+	{	PCI_VENDOR_ID_OXSEMI, 0xc101,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc105,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc11b,    /* OXPCIe952 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc11f,    /* OXPCIe952 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc120,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc124,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc138,    /* OXPCIe952 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc13d,    /* OXPCIe952 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc140,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc141,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc144,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc145,    /* OXPCIe952 1 Legacy UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc158,    /* OXPCIe952 2 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_2_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc15d,    /* OXPCIe952 2 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_2_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc208,    /* OXPCIe954 4 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_4_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc20d,    /* OXPCIe954 4 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_4_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc308,    /* OXPCIe958 8 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_8_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc30d,    /* OXPCIe958 8 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_8_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc40b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc40f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc41b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc41f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc42b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc42f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc43b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc43f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc44b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc44f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc45b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc45f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc46b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc46f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc47b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc47f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc48b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc48f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc49b,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc49f,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc4ab,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc4af,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc4bb,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc4bf,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc4cb,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_OXSEMI, 0xc4cf,    /* OXPCIe200 1 Native UART */
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	/*
+	 * Mainpine Inc. IQ Express "Rev3" utilizing OxSemi Tornado
+	 */
+	{	PCI_VENDOR_ID_MAINPINE, 0x4000,	/* IQ Express 1 Port V.34 Super-G3 Fax */
+		PCI_VENDOR_ID_MAINPINE, 0x4001, 0, 0,
+		pbn_oxsemi_1_15625000 },
+	{	PCI_VENDOR_ID_MAINPINE, 0x4000,	/* IQ Express 2 Port V.34 Super-G3 Fax */
+		PCI_VENDOR_ID_MAINPINE, 0x4002, 0, 0,
+		pbn_oxsemi_2_15625000 },
+	{	PCI_VENDOR_ID_MAINPINE, 0x4000,	/* IQ Express 4 Port V.34 Super-G3 Fax */
+		PCI_VENDOR_ID_MAINPINE, 0x4004, 0, 0,
+		pbn_oxsemi_4_15625000 },
+	{	PCI_VENDOR_ID_MAINPINE, 0x4000,	/* IQ Express 8 Port V.34 Super-G3 Fax */
+		PCI_VENDOR_ID_MAINPINE, 0x4008, 0, 0,
+		pbn_oxsemi_8_15625000 },
+
+	/*
+	 * Digi/IBM PCIe 2-port Async EIA-232 Adapter utilizing OxSemi Tornado
+	 */
+	{	PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_2_OX_IBM,
+		PCI_SUBVENDOR_ID_IBM, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * EndRun Technologies. PCI express device range.
+	 * EndRun PTP/1588 has 2 Native UARTs utilizing OxSemi 952.
+	 */
+	{	PCI_VENDOR_ID_ENDRUN, PCI_DEVICE_ID_ENDRUN_1588,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi_2_15625000 },
+
+	/*
+	 * SBS Technologies, Inc. P-Octal and PMC-OCTPRO cards,
+	 * from skokodyn@yahoo.com
+	 */
+	{	PCI_VENDOR_ID_SBSMODULARIO, PCI_DEVICE_ID_OCTPRO,
+		PCI_SUBVENDOR_ID_SBSMODULARIO, PCI_SUBDEVICE_ID_OCTPRO232, 0, 0,
+		pbn_sbsxrsio },
+	{	PCI_VENDOR_ID_SBSMODULARIO, PCI_DEVICE_ID_OCTPRO,
+		PCI_SUBVENDOR_ID_SBSMODULARIO, PCI_SUBDEVICE_ID_OCTPRO422, 0, 0,
+		pbn_sbsxrsio },
+	{	PCI_VENDOR_ID_SBSMODULARIO, PCI_DEVICE_ID_OCTPRO,
+		PCI_SUBVENDOR_ID_SBSMODULARIO, PCI_SUBDEVICE_ID_POCTAL232, 0, 0,
+		pbn_sbsxrsio },
+	{	PCI_VENDOR_ID_SBSMODULARIO, PCI_DEVICE_ID_OCTPRO,
+		PCI_SUBVENDOR_ID_SBSMODULARIO, PCI_SUBDEVICE_ID_POCTAL422, 0, 0,
+		pbn_sbsxrsio },
+
+	/*
+	 * Digitan DS560-558, from jimd@esoft.com
+	 */
+	{	PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_ATT_VENUS_MODEM,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_1_115200 },
+
+	/*
+	 * Titan Electronic cards
+	 *  The 400L and 800L have a custom setup quirk.
+	 */
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_100,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_2_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_400,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_100L,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_1_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200L,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_2_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_400L,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800L,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_8_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200I,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b4_bt_2_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_400I,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b4_bt_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800I,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b4_bt_8_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_400EH,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800EH,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800EHB,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_100E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_titan_1_4000000 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_titan_2_4000000 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_400E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_titan_4_4000000 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_titan_8_4000000 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200EI,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_titan_2_4000000 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200EISI,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_titan_2_4000000 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_200V3,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_400V3,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_410V3,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800V3,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_TITAN, PCI_DEVICE_ID_TITAN_800V3B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_4_921600 },
+
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S_10x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_460800 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S_10x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_460800 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S_10x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_460800 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S_10x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S_10x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S_10x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_4S_10x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_4_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_4S_10x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_4_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_4S_10x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_4_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S_20x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S_20x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S_20x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S_20x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S_20x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S_20x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_4S_20x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_4_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_4S_20x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_4_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_4S_20x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_4_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_8S_20x_550,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_8_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_8S_20x_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_8_921600 },
+	{	PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_8S_20x_850,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_8_921600 },
+
+	/*
+	 * Computone devices submitted by Doug McNash dmcnash@computone.com
+	 */
+	{	PCI_VENDOR_ID_COMPUTONE, PCI_DEVICE_ID_COMPUTONE_PG,
+		PCI_SUBVENDOR_ID_COMPUTONE, PCI_SUBDEVICE_ID_COMPUTONE_PG4,
+		0, 0, pbn_computone_4 },
+	{	PCI_VENDOR_ID_COMPUTONE, PCI_DEVICE_ID_COMPUTONE_PG,
+		PCI_SUBVENDOR_ID_COMPUTONE, PCI_SUBDEVICE_ID_COMPUTONE_PG8,
+		0, 0, pbn_computone_8 },
+	{	PCI_VENDOR_ID_COMPUTONE, PCI_DEVICE_ID_COMPUTONE_PG,
+		PCI_SUBVENDOR_ID_COMPUTONE, PCI_SUBDEVICE_ID_COMPUTONE_PG6,
+		0, 0, pbn_computone_6 },
+
+	{	PCI_VENDOR_ID_OXSEMI, PCI_DEVICE_ID_OXSEMI_16PCI95N,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_oxsemi },
+	{	PCI_VENDOR_ID_TIMEDIA, PCI_DEVICE_ID_TIMEDIA_1889,
+		PCI_VENDOR_ID_TIMEDIA, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_1_921600 },
+
+	/*
+	 * Sunix PCI serial boards
+	 */
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0001, 0, 0,
+		pbn_sunix_pci_1s },
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0002, 0, 0,
+		pbn_sunix_pci_2s },
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0004, 0, 0,
+		pbn_sunix_pci_4s },
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0084, 0, 0,
+		pbn_sunix_pci_4s },
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0008, 0, 0,
+		pbn_sunix_pci_8s },
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0088, 0, 0,
+		pbn_sunix_pci_8s },
+	{	PCI_VENDOR_ID_SUNIX, PCI_DEVICE_ID_SUNIX_1999,
+		PCI_VENDOR_ID_SUNIX, 0x0010, 0, 0,
+		pbn_sunix_pci_16s },
+
+	/*
+	 * AFAVLAB serial card, from Harald Welte <laforge@gnumonks.org>
+	 */
+	{	PCI_VENDOR_ID_AFAVLAB, PCI_DEVICE_ID_AFAVLAB_P028,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_8_115200 },
+	{	PCI_VENDOR_ID_AFAVLAB, PCI_DEVICE_ID_AFAVLAB_P030,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_8_115200 },
+
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_DSERIAL,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_115200 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATRO_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_115200 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATRO_B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_115200 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATTRO_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_115200 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATTRO_B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_115200 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_OCTO_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_4_460800 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_OCTO_B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_4_460800 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_PORT_PLUS,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_460800 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUAD_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_460800 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUAD_B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_2_460800 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_SSERIAL,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_1_115200 },
+	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_PORT_650,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_bt_1_460800 },
+
+	/*
+	 * Korenix Jetcard F0/F1 cards (JC1204, JC1208, JC1404, JC1408).
+	 * Cards are identified by their subsystem vendor IDs, which
+	 * (in hex) match the model number.
+	 *
+	 * Note that JC140x are RS422/485 cards which require ox950
+	 * ACR = 0x10, and as such are not currently fully supported.
+	 */
+	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF0,
+		0x1204, 0x0004, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF0,
+		0x1208, 0x0004, 0, 0,
+		pbn_b0_4_921600 },
+/*	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF0,
+		0x1402, 0x0002, 0, 0,
+		pbn_b0_2_921600 }, */
+/*	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF0,
+		0x1404, 0x0004, 0, 0,
+		pbn_b0_4_921600 }, */
+	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF1,
+		0x1208, 0x0004, 0, 0,
+		pbn_b0_4_921600 },
+
+	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF2,
+		0x1204, 0x0004, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF2,
+		0x1208, 0x0004, 0, 0,
+		pbn_b0_4_921600 },
+	{	PCI_VENDOR_ID_KORENIX, PCI_DEVICE_ID_KORENIX_JETCARDF3,
+		0x1208, 0x0004, 0, 0,
+		pbn_b0_4_921600 },
+	/*
+	 * Dell Remote Access Card 4 - Tim_T_Murphy@Dell.com
+	 */
+	{	PCI_VENDOR_ID_DELL, PCI_DEVICE_ID_DELL_RAC4,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_1_1382400 },
+
+	/*
+	 * Dell Remote Access Card III - Tim_T_Murphy@Dell.com
+	 */
+	{	PCI_VENDOR_ID_DELL, PCI_DEVICE_ID_DELL_RACIII,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_1_1382400 },
+
+	/*
+	 * RAStel 2 port modem, gerg@moreton.com.au
+	 */
+	{	PCI_VENDOR_ID_MORETON, PCI_DEVICE_ID_RASTEL_2PORT,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_bt_2_115200 },
+
+	/*
+	 * EKF addition for i960 Boards form EKF with serial port
+	 */
+	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_80960_RP,
+		0xE4BF, PCI_ANY_ID, 0, 0,
+		pbn_intel_i960 },
+
+	/*
+	 * Xircom Cardbus/Ethernet combos
+	 */
+	{	PCI_VENDOR_ID_XIRCOM, PCI_DEVICE_ID_XIRCOM_X3201_MDM,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_115200 },
+	/*
+	 * Xircom RBM56G cardbus modem - Dirk Arnold (temp entry)
+	 */
+	{	PCI_VENDOR_ID_XIRCOM, PCI_DEVICE_ID_XIRCOM_RBM56G,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_115200 },
+
+	/*
+	 * Untested PCI modems, sent in from various folks...
+	 */
+
+	/*
+	 * Elsa Model 56K PCI Modem, from Andreas Rath <arh@01019freenet.de>
+	 */
+	{	PCI_VENDOR_ID_ROCKWELL, 0x1004,
+		0x1048, 0x1500, 0, 0,
+		pbn_b1_1_115200 },
+
+	{	PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
+		0xFF00, 0, 0, 0,
+		pbn_sgi_ioc3 },
+
+	/*
+	 * HP Diva card
+	 */
+	{	PCI_VENDOR_ID_HP, PCI_DEVICE_ID_HP_DIVA,
+		PCI_VENDOR_ID_HP, PCI_DEVICE_ID_HP_DIVA_RMP3, 0, 0,
+		pbn_b1_1_115200 },
+	{	PCI_VENDOR_ID_HP, PCI_DEVICE_ID_HP_DIVA,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_5_115200 },
+	{	PCI_VENDOR_ID_HP, PCI_DEVICE_ID_HP_DIVA_AUX,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_115200 },
+	/* HPE PCI serial device */
+	{	PCI_VENDOR_ID_HP_3PAR, PCI_DEVICE_ID_HPE_PCI_SERIAL,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_1_115200 },
+
+	{	PCI_VENDOR_ID_DCI, PCI_DEVICE_ID_DCI_PCCOM2,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b3_2_115200 },
+	{	PCI_VENDOR_ID_DCI, PCI_DEVICE_ID_DCI_PCCOM4,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b3_4_115200 },
+	{	PCI_VENDOR_ID_DCI, PCI_DEVICE_ID_DCI_PCCOM8,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b3_8_115200 },
+	/*
+	 * Topic TP560 Data/Fax/Voice 56k modem (reported by Evan Clarke)
+	 */
+	{	PCI_VENDOR_ID_TOPIC, PCI_DEVICE_ID_TOPIC_TP560,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b0_1_115200 },
+	/*
+	 * ITE
+	 */
+	{	PCI_VENDOR_ID_ITE, PCI_DEVICE_ID_ITE_8872,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b1_bt_1_115200 },
+
+	/*
+	 * IntaShield IS-100
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0D60,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b2_1_115200 },
+	/*
+	 * IntaShield IS-200
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, PCI_DEVICE_ID_INTASHIELD_IS200,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,	/* 135a.0811 */
+		pbn_b2_2_115200 },
+	/*
+	 * IntaShield IS-400
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, PCI_DEVICE_ID_INTASHIELD_IS400,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,    /* 135a.0dc0 */
+		pbn_b2_4_115200 },
+	/*
+	 * IntaShield IX-100
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4027,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
+	/*
+	 * IntaShield IX-200
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4028,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * IntaShield IX-400
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4029,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_4_15625000 },
+	/* Brainboxes Devices */
+	/*
+	* Brainboxes UC-101
+	*/
+	{       PCI_VENDOR_ID_INTASHIELD, 0x0BA1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-235/246
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0AA1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_1_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0AA2,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_1_115200 },
+	/*
+	 * Brainboxes UC-253/UC-734
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0CA1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-260/271/701/756
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0D21,
+		PCI_ANY_ID, PCI_ANY_ID,
+		PCI_CLASS_COMMUNICATION_MULTISERIAL << 8, 0xffff00,
+		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0E34,
+		PCI_ANY_ID, PCI_ANY_ID,
+		PCI_CLASS_COMMUNICATION_MULTISERIAL << 8, 0xffff00,
+		pbn_b2_4_115200 },
+	/*
+	 * Brainboxes UC-268
+	 */
+	{       PCI_VENDOR_ID_INTASHIELD, 0x0841,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	/*
+	 * Brainboxes UC-275/279
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0881,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_8_115200 },
+	/*
+	 * Brainboxes UC-302
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x08E1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x08E2,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x08E3,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-310
+	 */
+	{       PCI_VENDOR_ID_INTASHIELD, 0x08C1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-313
+	 */
+	{       PCI_VENDOR_ID_INTASHIELD, 0x08A1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{       PCI_VENDOR_ID_INTASHIELD, 0x08A2,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{       PCI_VENDOR_ID_INTASHIELD, 0x08A3,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-320/324
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0A61,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_1_115200 },
+	/*
+	 * Brainboxes UC-346
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0B01,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0B02,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	/*
+	 * Brainboxes UC-357
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0A81,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0A82,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0A83,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-368
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C41,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	/*
+	 * Brainboxes UC-420
+	 */
+	{       PCI_VENDOR_ID_INTASHIELD, 0x0921,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	/*
+	 * Brainboxes UC-607
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x09A1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x09A2,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x09A3,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UC-836
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0D41,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	/*
+	 * Brainboxes UP-189
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0AC1,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0AC2,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0AC3,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UP-200
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0B21,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0B22,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0B23,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UP-869
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C01,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C02,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C03,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes UP-880
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C21,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C22,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C23,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	/*
+	 * Brainboxes PX-101
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4005,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4019,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * Brainboxes PX-235/246
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4004,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_1_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4016,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
+	/*
+	 * Brainboxes PX-203/PX-257
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4006,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4015,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * Brainboxes PX-260/PX-701
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x400A,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_4_15625000 },
+	/*
+	 * Brainboxes PX-275/279
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0E41,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_8_115200 },
+	/*
+	 * Brainboxes PX-310
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x400E,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * Brainboxes PX-313
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x400C,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * Brainboxes PX-320/324/PX-376/PX-387
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x400B,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
+	/*
+	 * Brainboxes PX-335/346
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x400F,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_4_15625000 },
+	/*
+	 * Brainboxes PX-368
+	 */
+	{       PCI_VENDOR_ID_INTASHIELD, 0x4010,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_4_15625000 },
+	/*
+	 * Brainboxes PX-420
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4000,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_4_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4011,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_4_15625000 },
+	/*
+	 * Brainboxes PX-475
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x401D,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
+	/*
+	 * Brainboxes PX-803/PX-857
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4009,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_2_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4018,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x401E,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_2_15625000 },
+	/*
+	 * Brainboxes PX-820
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4002,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_4_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4013,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_4_15625000 },
+	/*
+	 * Brainboxes PX-846
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4008,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b0_1_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4017,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
+
+	/*
+	 * Perle PCI-RAS cards
+	 */
+	{       PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030,
+		PCI_SUBVENDOR_ID_PERLE, PCI_SUBDEVICE_ID_PCI_RAS4,
+		0, 0, pbn_b2_4_921600 },
+	{       PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030,
+		PCI_SUBVENDOR_ID_PERLE, PCI_SUBDEVICE_ID_PCI_RAS8,
+		0, 0, pbn_b2_8_921600 },
+
+	/*
+	 * Mainpine series cards: Fairly standard layout but fools
+	 * parts of the autodetect in some cases and uses otherwise
+	 * unmatched communications subclasses in the PCI Express case
+	 */
+
+	{	/* RockForceDUO */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0200,
+		0, 0, pbn_b0_2_115200 },
+	{	/* RockForceQUATRO */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0300,
+		0, 0, pbn_b0_4_115200 },
+	{	/* RockForceDUO+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0400,
+		0, 0, pbn_b0_2_115200 },
+	{	/* RockForceQUATRO+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0500,
+		0, 0, pbn_b0_4_115200 },
+	{	/* RockForce+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0600,
+		0, 0, pbn_b0_2_115200 },
+	{	/* RockForce+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0700,
+		0, 0, pbn_b0_4_115200 },
+	{	/* RockForceOCTO+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0800,
+		0, 0, pbn_b0_8_115200 },
+	{	/* RockForceDUO+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0C00,
+		0, 0, pbn_b0_2_115200 },
+	{	/* RockForceQUARTRO+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x0D00,
+		0, 0, pbn_b0_4_115200 },
+	{	/* RockForceOCTO+ */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x1D00,
+		0, 0, pbn_b0_8_115200 },
+	{	/* RockForceD1 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2000,
+		0, 0, pbn_b0_1_115200 },
+	{	/* RockForceF1 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2100,
+		0, 0, pbn_b0_1_115200 },
+	{	/* RockForceD2 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2200,
+		0, 0, pbn_b0_2_115200 },
+	{	/* RockForceF2 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2300,
+		0, 0, pbn_b0_2_115200 },
+	{	/* RockForceD4 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2400,
+		0, 0, pbn_b0_4_115200 },
+	{	/* RockForceF4 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2500,
+		0, 0, pbn_b0_4_115200 },
+	{	/* RockForceD8 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2600,
+		0, 0, pbn_b0_8_115200 },
+	{	/* RockForceF8 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x2700,
+		0, 0, pbn_b0_8_115200 },
+	{	/* IQ Express D1 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3000,
+		0, 0, pbn_b0_1_115200 },
+	{	/* IQ Express F1 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3100,
+		0, 0, pbn_b0_1_115200 },
+	{	/* IQ Express D2 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3200,
+		0, 0, pbn_b0_2_115200 },
+	{	/* IQ Express F2 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3300,
+		0, 0, pbn_b0_2_115200 },
+	{	/* IQ Express D4 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3400,
+		0, 0, pbn_b0_4_115200 },
+	{	/* IQ Express F4 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3500,
+		0, 0, pbn_b0_4_115200 },
+	{	/* IQ Express D8 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3C00,
+		0, 0, pbn_b0_8_115200 },
+	{	/* IQ Express F8 */
+		PCI_VENDOR_ID_MAINPINE, PCI_DEVICE_ID_MAINPINE_PBRIDGE,
+		PCI_VENDOR_ID_MAINPINE, 0x3D00,
+		0, 0, pbn_b0_8_115200 },
+
+
+	/*
+	 * PA Semi PA6T-1682M on-chip UART
+	 */
+	{	PCI_VENDOR_ID_PASEMI, 0xa004,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_pasemi_1682M },
+
+	/*
+	 * National Instruments
+	 */
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI23216,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_16_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI2328,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_8_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_4_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_2_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI2324I,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_4_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI2322I,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_2_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8420_23216,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_16_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8420_2328,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_8_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8420_2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_4_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8420_2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_2_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8422_2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_4_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8422_2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_b1_bt_2_115200 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8430_2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_2 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI8430_2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_2 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8430_2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_4 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI8430_2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_4 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8430_2328,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_8 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI8430_2328,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_8 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8430_23216,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_16 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI8430_23216,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_16 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8432_2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_2 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI8432_2322,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_2 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PXI8432_2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_4 },
+	{	PCI_VENDOR_ID_NI, PCI_DEVICE_ID_NI_PCI8432_2324,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_ni8430_4 },
+
+	/*
+	 * MOXA
+	 */
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP102E,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_2p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP102EL,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_2p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP104EL_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_4p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP114EL,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_4p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP116E_A_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_8p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP116E_A_B,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_8p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP118EL_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_8p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP118E_A_I,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_8p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP132EL,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_2p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP134EL_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_4p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP138E_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_8p },
+	{	PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_CP168EL_A,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_moxa8250_8p },
+
+	/*
+	* ADDI-DATA GmbH communication cards <info@addi-data.com>
+	*/
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7500,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_4_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7420,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_2_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7300,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_AMCC,
+		PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b1_8_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7500_2,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_4_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7420_2,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_2_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7300_2,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7500_3,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_4_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7420_3,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_2_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7300_3,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCI7800_3,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_b0_8_115200 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCIe7500,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_ADDIDATA_PCIe_4_3906250 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCIe7420,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_ADDIDATA_PCIe_2_3906250 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCIe7300,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_ADDIDATA_PCIe_1_3906250 },
+
+	{	PCI_VENDOR_ID_ADDIDATA,
+		PCI_DEVICE_ID_ADDIDATA_APCIe7800,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+		0,
+		0,
+		pbn_ADDIDATA_PCIe_8_3906250 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9835,
+		PCI_VENDOR_ID_IBM, 0x0299,
+		0, 0, pbn_b0_bt_2_115200 },
+
+	/*
+	 * other NetMos 9835 devices are most likely handled by the
+	 * parport_serial driver, check drivers/parport/parport_serial.c
+	 * before adding them here.
+	 */
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9901,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	/* the 9901 is a rebranded 9912 */
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9912,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9922,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9904,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9900,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9900,
+		0xA000, 0x3002,
+		0, 0, pbn_NETMOS9900_2s_115200 },
+
+	/*
+	 * Best Connectivity and Rosewill PCI Multi I/O cards
+	 */
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9865,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9865,
+		0xA000, 0x3002,
+		0, 0, pbn_b0_bt_2_115200 },
+
+	{	PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9865,
+		0xA000, 0x3004,
+		0, 0, pbn_b0_bt_4_115200 },
+
+	/*
+	 * ASIX AX99100 PCIe to Multi I/O Controller
+	 */
+	{	PCI_VENDOR_ID_ASIX, PCI_DEVICE_ID_ASIX_AX99100,
+		0xA000, 0x1000,
+		0, 0, pbn_b0_1_115200 },
+
+	/* Intel CE4100 */
+	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CE4100_UART,
+		PCI_ANY_ID,  PCI_ANY_ID, 0, 0,
+		pbn_ce4100_1_115200 },
+
+	/*
+	 * Cronyx Omega PCI
+	 */
+	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_CRONYX_OMEGA,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_omegapci },
+
+	/*
+	 * Broadcom TruManage
+	 */
+	{	PCI_VENDOR_ID_BROADCOM, PCI_DEVICE_ID_BROADCOM_TRUMANAGE,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		pbn_brcm_trumanage },
+
+	/*
+	 * AgeStar as-prs2-009
+	 */
+	{	PCI_VENDOR_ID_AGESTAR, PCI_DEVICE_ID_AGESTAR_9375,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_b0_bt_2_115200 },
+
+	/*
+	 * WCH CH353 series devices: The 2S1P is handled by parport_serial
+	 * so not listed here.
+	 */
+	{	PCI_VENDOR_ID_WCH, PCI_DEVICE_ID_WCH_CH353_4S,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_b0_bt_4_115200 },
+
+	{	PCI_VENDOR_ID_WCH, PCI_DEVICE_ID_WCH_CH353_2S1PF,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_b0_bt_2_115200 },
+
+	{	PCI_VENDOR_ID_WCH, PCI_DEVICE_ID_WCH_CH355_4S,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_b0_bt_4_115200 },
+
+	{	PCIE_VENDOR_ID_WCH, PCIE_DEVICE_ID_WCH_CH382_2S,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_wch382_2 },
+
+	{	PCIE_VENDOR_ID_WCH, PCIE_DEVICE_ID_WCH_CH384_4S,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_wch384_4 },
+
+	{	PCIE_VENDOR_ID_WCH, PCIE_DEVICE_ID_WCH_CH384_8S,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_wch384_8 },
+	/*
+	 * Realtek RealManage
+	 */
+	{	PCI_VENDOR_ID_REALTEK, 0x816a,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_b0_1_115200 },
+
+	{	PCI_VENDOR_ID_REALTEK, 0x816b,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0, pbn_b0_1_115200 },
+
+	/* Fintek PCI serial cards */
+	{ PCI_DEVICE(0x1c29, 0x1104), .driver_data = pbn_fintek_4 },
+	{ PCI_DEVICE(0x1c29, 0x1108), .driver_data = pbn_fintek_8 },
+	{ PCI_DEVICE(0x1c29, 0x1112), .driver_data = pbn_fintek_12 },
+	{ PCI_DEVICE(0x1c29, 0x1204), .driver_data = pbn_fintek_F81504A },
+	{ PCI_DEVICE(0x1c29, 0x1208), .driver_data = pbn_fintek_F81508A },
+	{ PCI_DEVICE(0x1c29, 0x1212), .driver_data = pbn_fintek_F81512A },
+
+	/* MKS Tenta SCOM-080x serial cards */
+	{ PCI_DEVICE(0x1601, 0x0800), .driver_data = pbn_b0_4_1250000 },
+	{ PCI_DEVICE(0x1601, 0xa801), .driver_data = pbn_b0_4_1250000 },
+
+	/* Amazon PCI serial device */
+	{ PCI_DEVICE(0x1d0f, 0x8250), .driver_data = pbn_b0_1_115200 },
+
+	/*
+	 * These entries match devices with class COMMUNICATION_SERIAL,
+	 * COMMUNICATION_MODEM or COMMUNICATION_MULTISERIAL
+	 */
+	{	PCI_ANY_ID, PCI_ANY_ID,
+		PCI_ANY_ID, PCI_ANY_ID,
+		PCI_CLASS_COMMUNICATION_SERIAL << 8,
+		0xffff00, pbn_default },
+	{	PCI_ANY_ID, PCI_ANY_ID,
+		PCI_ANY_ID, PCI_ANY_ID,
+		PCI_CLASS_COMMUNICATION_MODEM << 8,
+		0xffff00, pbn_default },
+	{	PCI_ANY_ID, PCI_ANY_ID,
+		PCI_ANY_ID, PCI_ANY_ID,
+		PCI_CLASS_COMMUNICATION_MULTISERIAL << 8,
+		0xffff00, pbn_default },
+	{ 0, }
+};
+
+static pci_ers_result_t serial8250_io_error_detected(struct pci_dev *dev,
+						pci_channel_state_t state)
+{
+	struct serial_private *priv = pci_get_drvdata(dev);
+
+	if (state == pci_channel_io_perm_failure)
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	if (priv)
+		pciserial_detach_ports(priv);
+
+	pci_disable_device(dev);
+
+	return PCI_ERS_RESULT_NEED_RESET;
+}
+
+static pci_ers_result_t serial8250_io_slot_reset(struct pci_dev *dev)
+{
+	int rc;
+
+	rc = pci_enable_device(dev);
+
+	if (rc)
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	pci_restore_state(dev);
+	pci_save_state(dev);
+
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void serial8250_io_resume(struct pci_dev *dev)
+{
+	struct serial_private *priv = pci_get_drvdata(dev);
+	struct serial_private *new;
+
+	if (!priv)
+		return;
+
+	new = pciserial_init_ports(dev, priv->board);
+	if (!IS_ERR(new)) {
+		pci_set_drvdata(dev, new);
+		kfree(priv);
+	}
+}
+
+static const struct pci_error_handlers serial8250_err_handler = {
+	.error_detected = serial8250_io_error_detected,
+	.slot_reset = serial8250_io_slot_reset,
+	.resume = serial8250_io_resume,
+};
+
+static struct pci_driver serial_pci_driver = {
+	.name		= "serial",
+	.probe		= pciserial_init_one,
+	.remove		= pciserial_remove_one,
+	.driver         = {
+		.pm     = &pciserial_pm_ops,
+	},
+	.id_table	= serial_pci_tbl,
+	.err_handler	= &serial8250_err_handler,
+};
+
+module_pci_driver(serial_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Generic 8250/16x50 PCI serial probe module");
+MODULE_DEVICE_TABLE(pci, serial_pci_tbl);
+MODULE_IMPORT_NS(SERIAL_8250_PCI);
diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
new file mode 100644
index 000000000..a3b25779d
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Probe module for 8250/16550-type MCHP PCI serial ports.
+ *
+ *  Based on drivers/tty/serial/8250/8250_pci.c,
+ *
+ *  Copyright (C) 2022 Microchip Technology Inc., All Rights Reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/units.h>
+#include <linux/tty.h>
+
+#include <asm/byteorder.h>
+
+#include "8250.h"
+#include "8250_pcilib.h"
+
+#define PCI_DEVICE_ID_EFAR_PCI12000		0xa002
+#define PCI_DEVICE_ID_EFAR_PCI11010		0xa012
+#define PCI_DEVICE_ID_EFAR_PCI11101		0xa022
+#define PCI_DEVICE_ID_EFAR_PCI11400		0xa032
+#define PCI_DEVICE_ID_EFAR_PCI11414		0xa042
+
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_4p	0x0001
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p012	0x0002
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p013	0x0003
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p023	0x0004
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p123	0x0005
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p01	0x0006
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p02	0x0007
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p03	0x0008
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p12	0x0009
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p13	0x000a
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p23	0x000b
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p0	0x000c
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p1	0x000d
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p2	0x000e
+#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3	0x000f
+
+#define PCI_SUBDEVICE_ID_EFAR_PCI12000		PCI_DEVICE_ID_EFAR_PCI12000
+#define PCI_SUBDEVICE_ID_EFAR_PCI11010		PCI_DEVICE_ID_EFAR_PCI11010
+#define PCI_SUBDEVICE_ID_EFAR_PCI11101		PCI_DEVICE_ID_EFAR_PCI11101
+#define PCI_SUBDEVICE_ID_EFAR_PCI11400		PCI_DEVICE_ID_EFAR_PCI11400
+#define PCI_SUBDEVICE_ID_EFAR_PCI11414		PCI_DEVICE_ID_EFAR_PCI11414
+
+#define UART_ACTV_REG				0x11
+#define UART_BLOCK_SET_ACTIVE			BIT(0)
+
+#define UART_PCI_CTRL_REG			0x80
+#define UART_PCI_CTRL_SET_MULTIPLE_MSI		BIT(4)
+#define UART_PCI_CTRL_D3_CLK_ENABLE		BIT(0)
+
+#define ADCL_CFG_REG				0x40
+#define ADCL_CFG_POL_SEL			BIT(2)
+#define ADCL_CFG_PIN_SEL			BIT(1)
+#define ADCL_CFG_EN				BIT(0)
+
+#define UART_BIT_SAMPLE_CNT			16
+#define BAUD_CLOCK_DIV_INT_MSK			GENMASK(31, 8)
+#define ADCL_CFG_RTS_DELAY_MASK			GENMASK(11, 8)
+#define UART_CLOCK_DEFAULT			(62500 * HZ_PER_KHZ)
+
+#define UART_WAKE_REG				0x8C
+#define UART_WAKE_MASK_REG			0x90
+#define UART_WAKE_N_PIN				BIT(2)
+#define UART_WAKE_NCTS				BIT(1)
+#define UART_WAKE_INT				BIT(0)
+#define UART_WAKE_SRCS	\
+	(UART_WAKE_N_PIN | UART_WAKE_NCTS | UART_WAKE_INT)
+
+#define UART_BAUD_CLK_DIVISOR_REG		0x54
+
+#define UART_RESET_REG				0x94
+#define UART_RESET_D3_RESET_DISABLE		BIT(16)
+
+#define MAX_PORTS				4
+#define PORT_OFFSET				0x100
+
+static const int logical_to_physical_port_idx[][MAX_PORTS] = {
+	{0,  1,  2,  3}, /* PCI12000, PCI11010, PCI11101, PCI11400, PCI11414 */
+	{0,  1,  2,  3}, /* PCI4p */
+	{0,  1,  2, -1}, /* PCI3p012 */
+	{0,  1,  3, -1}, /* PCI3p013 */
+	{0,  2,  3, -1}, /* PCI3p023 */
+	{1,  2,  3, -1}, /* PCI3p123 */
+	{0,  1, -1, -1}, /* PCI2p01 */
+	{0,  2, -1, -1}, /* PCI2p02 */
+	{0,  3, -1, -1}, /* PCI2p03 */
+	{1,  2, -1, -1}, /* PCI2p12 */
+	{1,  3, -1, -1}, /* PCI2p13 */
+	{2,  3, -1, -1}, /* PCI2p23 */
+	{0, -1, -1, -1}, /* PCI1p0 */
+	{1, -1, -1, -1}, /* PCI1p1 */
+	{2, -1, -1, -1}, /* PCI1p2 */
+	{3, -1, -1, -1}, /* PCI1p3 */
+};
+
+struct pci1xxxx_8250 {
+	unsigned int nr;
+	void __iomem *membase;
+	int line[];
+};
+
+static int pci1xxxx_get_num_ports(struct pci_dev *dev)
+{
+	switch (dev->subsystem_device) {
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p0:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p1:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p2:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3:
+	case PCI_SUBDEVICE_ID_EFAR_PCI12000:
+	case PCI_SUBDEVICE_ID_EFAR_PCI11010:
+	case PCI_SUBDEVICE_ID_EFAR_PCI11101:
+	case PCI_SUBDEVICE_ID_EFAR_PCI11400:
+	default:
+		return 1;
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p01:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p02:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p03:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p12:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p13:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p23:
+		return 2;
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p012:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p123:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p013:
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p023:
+		return 3;
+	case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_4p:
+	case PCI_SUBDEVICE_ID_EFAR_PCI11414:
+		return 4;
+	}
+}
+
+static unsigned int pci1xxxx_get_divisor(struct uart_port *port,
+					 unsigned int baud, unsigned int *frac)
+{
+	unsigned int quot;
+
+	/*
+	 * Calculate baud rate sampling period in nanoseconds.
+	 * Fractional part x denotes x/255 parts of a nanosecond.
+	 */
+	quot = NSEC_PER_SEC / (baud * UART_BIT_SAMPLE_CNT);
+	*frac = (NSEC_PER_SEC - quot * baud * UART_BIT_SAMPLE_CNT) *
+		  255 / UART_BIT_SAMPLE_CNT / baud;
+
+	return quot;
+}
+
+static void pci1xxxx_set_divisor(struct uart_port *port, unsigned int baud,
+				 unsigned int quot, unsigned int frac)
+{
+	writel(FIELD_PREP(BAUD_CLOCK_DIV_INT_MSK, quot) | frac,
+	       port->membase + UART_BAUD_CLK_DIVISOR_REG);
+}
+
+static int pci1xxxx_rs485_config(struct uart_port *port,
+				 struct ktermios *termios,
+				 struct serial_rs485 *rs485)
+{
+	u32 delay_in_baud_periods;
+	u32 baud_period_in_ns;
+	u32 mode_cfg = 0;
+	u32 clock_div;
+
+	/*
+	 * pci1xxxx's uart hardware supports only RTS delay after
+	 * Tx and in units of bit times to a maximum of 15
+	 */
+	if (rs485->flags & SER_RS485_ENABLED) {
+		mode_cfg = ADCL_CFG_EN | ADCL_CFG_PIN_SEL;
+
+		if (!(rs485->flags & SER_RS485_RTS_ON_SEND))
+			mode_cfg |= ADCL_CFG_POL_SEL;
+
+		if (rs485->delay_rts_after_send) {
+			clock_div = readl(port->membase + UART_BAUD_CLK_DIVISOR_REG);
+			baud_period_in_ns =
+				FIELD_GET(BAUD_CLOCK_DIV_INT_MSK, clock_div) *
+				UART_BIT_SAMPLE_CNT;
+			delay_in_baud_periods =
+				rs485->delay_rts_after_send * NSEC_PER_MSEC /
+				baud_period_in_ns;
+			delay_in_baud_periods =
+				min_t(u32, delay_in_baud_periods,
+				      FIELD_MAX(ADCL_CFG_RTS_DELAY_MASK));
+			mode_cfg |= FIELD_PREP(ADCL_CFG_RTS_DELAY_MASK,
+					   delay_in_baud_periods);
+			rs485->delay_rts_after_send =
+				baud_period_in_ns * delay_in_baud_periods /
+				NSEC_PER_MSEC;
+		}
+	}
+	writel(mode_cfg, port->membase + ADCL_CFG_REG);
+	return 0;
+}
+
+static const struct serial_rs485 pci1xxxx_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
+		 SER_RS485_RTS_AFTER_SEND,
+	.delay_rts_after_send = 1,
+	/* Delay RTS before send is not supported */
+};
+
+static bool pci1xxxx_port_suspend(int line)
+{
+	struct uart_8250_port *up = serial8250_get_port(line);
+	struct uart_port *port = &up->port;
+	struct tty_port *tport = &port->state->port;
+	unsigned long flags;
+	bool ret = false;
+	u8 wakeup_mask;
+
+	mutex_lock(&tport->mutex);
+	if (port->suspended == 0 && port->dev) {
+		wakeup_mask = readb(up->port.membase + UART_WAKE_MASK_REG);
+
+		spin_lock_irqsave(&port->lock, flags);
+		port->mctrl &= ~TIOCM_OUT2;
+		port->ops->set_mctrl(port, port->mctrl);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		ret = (wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS;
+	}
+
+	writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
+	mutex_unlock(&tport->mutex);
+
+	return ret;
+}
+
+static void pci1xxxx_port_resume(int line)
+{
+	struct uart_8250_port *up = serial8250_get_port(line);
+	struct uart_port *port = &up->port;
+	struct tty_port *tport = &port->state->port;
+	unsigned long flags;
+
+	mutex_lock(&tport->mutex);
+	writeb(UART_BLOCK_SET_ACTIVE, port->membase + UART_ACTV_REG);
+	writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
+
+	if (port->suspended == 0) {
+		spin_lock_irqsave(&port->lock, flags);
+		port->mctrl |= TIOCM_OUT2;
+		port->ops->set_mctrl(port, port->mctrl);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+	mutex_unlock(&tport->mutex);
+}
+
+static int pci1xxxx_suspend(struct device *dev)
+{
+	struct pci1xxxx_8250 *priv = dev_get_drvdata(dev);
+	struct pci_dev *pcidev = to_pci_dev(dev);
+	bool wakeup = false;
+	unsigned int data;
+	void __iomem *p;
+	int i;
+
+	for (i = 0; i < priv->nr; i++) {
+		if (priv->line[i] >= 0) {
+			serial8250_suspend_port(priv->line[i]);
+			wakeup |= pci1xxxx_port_suspend(priv->line[i]);
+		}
+	}
+
+	p = pci_ioremap_bar(pcidev, 0);
+	if (!p) {
+		dev_err(dev, "remapping of bar 0 memory failed");
+		return -ENOMEM;
+	}
+
+	data = readl(p + UART_RESET_REG);
+	writel(data | UART_RESET_D3_RESET_DISABLE, p + UART_RESET_REG);
+
+	if (wakeup)
+		writeb(UART_PCI_CTRL_D3_CLK_ENABLE, p + UART_PCI_CTRL_REG);
+
+	iounmap(p);
+	device_set_wakeup_enable(dev, true);
+	pci_wake_from_d3(pcidev, true);
+
+	return 0;
+}
+
+static int pci1xxxx_resume(struct device *dev)
+{
+	struct pci1xxxx_8250 *priv = dev_get_drvdata(dev);
+	struct pci_dev *pcidev = to_pci_dev(dev);
+	unsigned int data;
+	void __iomem *p;
+	int i;
+
+	p = pci_ioremap_bar(pcidev, 0);
+	if (!p) {
+		dev_err(dev, "remapping of bar 0 memory failed");
+		return -ENOMEM;
+	}
+
+	data = readl(p + UART_RESET_REG);
+	writel(data & ~UART_RESET_D3_RESET_DISABLE, p + UART_RESET_REG);
+	iounmap(p);
+
+	for (i = 0; i < priv->nr; i++) {
+		if (priv->line[i] >= 0) {
+			pci1xxxx_port_resume(priv->line[i]);
+			serial8250_resume_port(priv->line[i]);
+		}
+	}
+
+	return 0;
+}
+
+static int pci1xxxx_setup(struct pci_dev *pdev,
+			  struct uart_8250_port *port, int port_idx)
+{
+	int ret;
+
+	port->port.flags |= UPF_FIXED_TYPE | UPF_SKIP_TEST;
+	port->port.type = PORT_MCHP16550A;
+	port->port.set_termios = serial8250_do_set_termios;
+	port->port.get_divisor = pci1xxxx_get_divisor;
+	port->port.set_divisor = pci1xxxx_set_divisor;
+	port->port.rs485_config = pci1xxxx_rs485_config;
+	port->port.rs485_supported = pci1xxxx_rs485_supported;
+
+	ret = serial8250_pci_setup_port(pdev, port, 0, PORT_OFFSET * port_idx, 0);
+	if (ret < 0)
+		return ret;
+
+	writeb(UART_BLOCK_SET_ACTIVE, port->port.membase + UART_ACTV_REG);
+	writeb(UART_WAKE_SRCS, port->port.membase + UART_WAKE_REG);
+	writeb(UART_WAKE_N_PIN, port->port.membase + UART_WAKE_MASK_REG);
+
+	return 0;
+}
+
+static unsigned int pci1xxxx_get_max_port(int subsys_dev)
+{
+	unsigned int i = MAX_PORTS;
+
+	if (subsys_dev < ARRAY_SIZE(logical_to_physical_port_idx))
+		while (i--) {
+			if (logical_to_physical_port_idx[subsys_dev][i] != -1)
+				return logical_to_physical_port_idx[subsys_dev][i] + 1;
+		}
+
+	if (subsys_dev == PCI_SUBDEVICE_ID_EFAR_PCI11414)
+		return 4;
+
+	return 1;
+}
+
+static int pci1xxxx_logical_to_physical_port_translate(int subsys_dev, int port)
+{
+	if (subsys_dev < ARRAY_SIZE(logical_to_physical_port_idx))
+		return logical_to_physical_port_idx[subsys_dev][port];
+
+	return logical_to_physical_port_idx[0][port];
+}
+
+static int pci1xxxx_serial_probe(struct pci_dev *pdev,
+				 const struct pci_device_id *id)
+{
+	struct device *dev = &pdev->dev;
+	struct pci1xxxx_8250 *priv;
+	struct uart_8250_port uart;
+	unsigned int max_vec_reqd;
+	unsigned int nr_ports, i;
+	int num_vectors;
+	int subsys_dev;
+	int port_idx;
+	int rc;
+
+	rc = pcim_enable_device(pdev);
+	if (rc)
+		return rc;
+
+	nr_ports = pci1xxxx_get_num_ports(pdev);
+
+	priv = devm_kzalloc(dev, struct_size(priv, line, nr_ports), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->membase = pci_ioremap_bar(pdev, 0);
+	if (!priv->membase)
+		return -ENOMEM;
+
+	pci_set_master(pdev);
+
+	priv->nr = nr_ports;
+
+	subsys_dev = pdev->subsystem_device;
+	max_vec_reqd = pci1xxxx_get_max_port(subsys_dev);
+
+	num_vectors = pci_alloc_irq_vectors(pdev, 1, max_vec_reqd, PCI_IRQ_ALL_TYPES);
+	if (num_vectors < 0) {
+		pci_iounmap(pdev, priv->membase);
+		return num_vectors;
+	}
+
+	memset(&uart, 0, sizeof(uart));
+	uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT;
+	uart.port.uartclk = UART_CLOCK_DEFAULT;
+	uart.port.dev = dev;
+
+	if (num_vectors == max_vec_reqd)
+		writeb(UART_PCI_CTRL_SET_MULTIPLE_MSI, priv->membase + UART_PCI_CTRL_REG);
+
+	for (i = 0; i < nr_ports; i++) {
+		priv->line[i] = -ENODEV;
+
+		port_idx = pci1xxxx_logical_to_physical_port_translate(subsys_dev, i);
+
+		if (num_vectors == max_vec_reqd)
+			uart.port.irq = pci_irq_vector(pdev, port_idx);
+		else
+			uart.port.irq = pci_irq_vector(pdev, 0);
+
+		rc = pci1xxxx_setup(pdev, &uart, port_idx);
+		if (rc) {
+			dev_warn(dev, "Failed to setup port %u\n", i);
+			continue;
+		}
+
+		priv->line[i] = serial8250_register_8250_port(&uart);
+		if (priv->line[i] < 0) {
+			dev_warn(dev,
+				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
+				uart.port.iobase, uart.port.irq, uart.port.iotype,
+				priv->line[i]);
+		}
+	}
+
+	pci_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static void pci1xxxx_serial_remove(struct pci_dev *dev)
+{
+	struct pci1xxxx_8250 *priv = pci_get_drvdata(dev);
+	unsigned int i;
+
+	for (i = 0; i < priv->nr; i++) {
+		if (priv->line[i] >= 0)
+			serial8250_unregister_port(priv->line[i]);
+	}
+
+	pci_free_irq_vectors(dev);
+	pci_iounmap(dev, priv->membase);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(pci1xxxx_pm_ops, pci1xxxx_suspend, pci1xxxx_resume);
+
+static const struct pci_device_id pci1xxxx_pci_tbl[] = {
+	{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11010) },
+	{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11101) },
+	{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11400) },
+	{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11414) },
+	{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI12000) },
+	{}
+};
+MODULE_DEVICE_TABLE(pci, pci1xxxx_pci_tbl);
+
+static struct pci_driver pci1xxxx_pci_driver = {
+	.name = "pci1xxxx serial",
+	.probe = pci1xxxx_serial_probe,
+	.remove = pci1xxxx_serial_remove,
+	.driver = {
+		.pm     = pm_sleep_ptr(&pci1xxxx_pm_ops),
+	},
+	.id_table = pci1xxxx_pci_tbl,
+};
+module_pci_driver(pci1xxxx_pci_driver);
+
+static_assert((ARRAY_SIZE(logical_to_physical_port_idx) == PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3 + 1));
+
+MODULE_IMPORT_NS(SERIAL_8250_PCI);
+MODULE_DESCRIPTION("Microchip Technology Inc. PCIe to UART module");
+MODULE_AUTHOR("Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>");
+MODULE_AUTHOR("Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_pcilib.c b/drivers/tty/serial/8250/8250_pcilib.c
new file mode 100644
index 000000000..d234e9194
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pcilib.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 8250 PCI library.
+ *
+ * Copyright (C) 2001 Russell King, All Rights Reserved.
+ */
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+
+#include "8250.h"
+#include "8250_pcilib.h"
+
+int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
+		   u8 bar, unsigned int offset, int regshift)
+{
+	if (bar >= PCI_STD_NUM_BARS)
+		return -EINVAL;
+
+	if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
+		if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
+			return -ENOMEM;
+
+		port->port.iotype = UPIO_MEM;
+		port->port.iobase = 0;
+		port->port.mapbase = pci_resource_start(dev, bar) + offset;
+		port->port.membase = pcim_iomap_table(dev)[bar] + offset;
+		port->port.regshift = regshift;
+	} else {
+		port->port.iotype = UPIO_PORT;
+		port->port.iobase = pci_resource_start(dev, bar) + offset;
+		port->port.mapbase = 0;
+		port->port.membase = NULL;
+		port->port.regshift = 0;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(serial8250_pci_setup_port, SERIAL_8250_PCI);
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_pcilib.h b/drivers/tty/serial/8250/8250_pcilib.h
new file mode 100644
index 000000000..1aaf1b50c
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pcilib.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * 8250 PCI library header file.
+ *
+ * Copyright (C) 2001 Russell King, All Rights Reserved.
+ */
+
+#include <linux/types.h>
+
+struct pci_dev;
+
+struct uart_8250_port;
+
+int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port, u8 bar,
+		   unsigned int offset, int regshift);
diff --git a/drivers/tty/serial/8250/8250_pericom.c b/drivers/tty/serial/8250/8250_pericom.c
new file mode 100644
index 000000000..b8d5b7714
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pericom.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Driver for Pericom UART */
+
+#include <linux/bits.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/pci.h>
+
+#include "8250.h"
+
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SDB	0x1051
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2S	0x1053
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_4	0x105a
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_4	0x105b
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SDB	0x105c
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4S	0x105e
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_8	0x106a
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_8	0x106b
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_2DB	0x1091
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_2	0x1093
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4	0x1098
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4DB	0x1099
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_4	0x109b
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_8	0x10a9
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SMDB	0x10d1
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2SM	0x10d3
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SM	0x10d9
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SMDB	0x10da
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4SM	0x10dc
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_8SM	0x10e9
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_1	0x1108
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_2	0x1110
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_2	0x1111
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_4	0x1118
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_4	0x1119
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2S	0x1152
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4S	0x115a
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_2	0x1190
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_2	0x1191
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_4	0x1198
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_4	0x1199
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2SM	0x11d0
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4SM	0x11d8
+
+struct pericom8250 {
+	void __iomem *virt;
+	unsigned int nr;
+	int line[];
+};
+
+static void pericom_do_set_divisor(struct uart_port *port, unsigned int baud,
+				   unsigned int quot, unsigned int quot_frac)
+{
+	int scr;
+
+	for (scr = 16; scr > 4; scr--) {
+		unsigned int maxrate = port->uartclk / scr;
+		unsigned int divisor = max(maxrate / baud, 1U);
+		int delta = maxrate / divisor - baud;
+
+		if (baud > maxrate + baud / 50)
+			continue;
+
+		if (delta > baud / 50)
+			divisor++;
+
+		if (divisor > 0xffff)
+			continue;
+
+		/* Update delta due to possible divisor change */
+		delta = maxrate / divisor - baud;
+		if (abs(delta) < baud / 50) {
+			struct uart_8250_port *up = up_to_u8250p(port);
+			int lcr = serial_port_in(port, UART_LCR);
+
+			serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);
+			serial_dl_write(up, divisor);
+			serial_port_out(port, 2, 16 - scr);
+			serial_port_out(port, UART_LCR, lcr);
+			return;
+		}
+	}
+}
+
+static int pericom8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	unsigned int nr, i, bar = 0, maxnr;
+	struct pericom8250 *pericom;
+	struct uart_8250_port uart;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	maxnr = pci_resource_len(pdev, bar) >> 3;
+
+	if (pdev->vendor == PCI_VENDOR_ID_PERICOM)
+		nr = pdev->device & 0x0f;
+	else if (pdev->vendor == PCI_VENDOR_ID_ACCESSIO)
+		nr = BIT(((pdev->device & 0x38) >> 3) - 1);
+	else
+		nr = 1;
+
+	pericom = devm_kzalloc(&pdev->dev, struct_size(pericom, line, nr), GFP_KERNEL);
+	if (!pericom)
+		return -ENOMEM;
+
+	pericom->virt = pcim_iomap(pdev, bar, 0);
+	if (!pericom->virt)
+		return -ENOMEM;
+
+	memset(&uart, 0, sizeof(uart));
+
+	uart.port.dev = &pdev->dev;
+	uart.port.irq = pdev->irq;
+	uart.port.private_data = pericom;
+	uart.port.iotype = UPIO_PORT;
+	uart.port.uartclk = 921600 * 16;
+	uart.port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ;
+	uart.port.set_divisor = pericom_do_set_divisor;
+	for (i = 0; i < nr && i < maxnr; i++) {
+		unsigned int offset = (i == 3 && nr == 4) ? 0x38 : i * 0x8;
+
+		uart.port.iobase = pci_resource_start(pdev, bar) + offset;
+
+		dev_dbg(&pdev->dev, "Setup PCI port: port %lx, irq %d, type %d\n",
+			uart.port.iobase, uart.port.irq, uart.port.iotype);
+
+		pericom->line[i] = serial8250_register_8250_port(&uart);
+		if (pericom->line[i] < 0) {
+			dev_err(&pdev->dev,
+				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
+				uart.port.iobase, uart.port.irq,
+				uart.port.iotype, pericom->line[i]);
+			break;
+		}
+	}
+	pericom->nr = i;
+
+	pci_set_drvdata(pdev, pericom);
+	return 0;
+}
+
+static void pericom8250_remove(struct pci_dev *pdev)
+{
+	struct pericom8250 *pericom = pci_get_drvdata(pdev);
+	unsigned int i;
+
+	for (i = 0; i < pericom->nr; i++)
+		serial8250_unregister_port(pericom->line[i]);
+}
+
+static const struct pci_device_id pericom8250_pci_ids[] = {
+	/*
+	 * Pericom PI7C9X795[1248] Uno/Dual/Quad/Octal UART
+	 * (Only 7954 has an offset jump for port 4)
+	 */
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7951) },
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7952) },
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7954) },
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7958) },
+
+	/*
+	 * ACCES I/O Products quad
+	 * (Only 7954 has an offset jump for port 4)
+	 */
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_8) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_8) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_2DB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4DB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_8) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SMDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SMDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_8SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_1) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4SM) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, pericom8250_pci_ids);
+
+static struct pci_driver pericom8250_pci_driver = {
+	.name           = "8250_pericom",
+	.id_table       = pericom8250_pci_ids,
+	.probe          = pericom8250_probe,
+	.remove         = pericom8250_remove,
+};
+module_pci_driver(pericom8250_pci_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Pericom UART driver");
diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
new file mode 100644
index 000000000..1974bbadc
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Probe for 8250/16550-type ISAPNP serial ports.
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright (C) 2001 Russell King, All Rights Reserved.
+ *
+ *  Ported to the Linux PnP Layer - (C) Adam Belay.
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pnp.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/property.h>
+#include <linux/serial_core.h>
+#include <linux/bitops.h>
+
+#include <asm/byteorder.h>
+
+#include "8250.h"
+
+#define UNKNOWN_DEV 0x3000
+#define CIR_PORT	0x0800
+
+static const struct pnp_device_id pnp_dev_table[] = {
+	/* Archtek America Corp. */
+	/* Archtek SmartLink Modem 3334BT Plug & Play */
+	{	"AAC000F",		0	},
+	/* Anchor Datacomm BV */
+	/* SXPro 144 External Data Fax Modem Plug & Play */
+	{	"ADC0001",		0	},
+	/* SXPro 288 External Data Fax Modem Plug & Play */
+	{	"ADC0002",		0	},
+	/* PROLiNK 1456VH ISA PnP K56flex Fax Modem */
+	{	"AEI0250",		0	},
+	/* Actiontec ISA PNP 56K X2 Fax Modem */
+	{	"AEI1240",		0	},
+	/* Rockwell 56K ACF II Fax+Data+Voice Modem */
+	{	"AKY1021",		0 /*SPCI_FL_NO_SHIRQ*/	},
+	/*
+	 * ALi Fast Infrared Controller
+	 * Native driver (ali-ircc) is broken so at least
+	 * it can be used with irtty-sir.
+	 */
+	{	"ALI5123",		0	},
+	/* AZT3005 PnP SOUND DEVICE */
+	{	"AZT4001",		0	},
+	/* Best Data Products Inc. Smart One 336F PnP Modem */
+	{	"BDP3336",		0	},
+	/*  Boca Research */
+	/* Boca Complete Ofc Communicator 14.4 Data-FAX */
+	{	"BRI0A49",		0	},
+	/* Boca Research 33,600 ACF Modem */
+	{	"BRI1400",		0	},
+	/* Boca 33.6 Kbps Internal FD34FSVD */
+	{	"BRI3400",		0	},
+	/* Computer Peripherals Inc */
+	/* EuroViVa CommCenter-33.6 SP PnP */
+	{	"CPI4050",		0	},
+	/* Creative Labs */
+	/* Creative Labs Phone Blaster 28.8 DSVD PnP Voice */
+	{	"CTL3001",		0	},
+	/* Creative Labs Modem Blaster 28.8 DSVD PnP Voice */
+	{	"CTL3011",		0	},
+	/* Davicom ISA 33.6K Modem */
+	{	"DAV0336",		0	},
+	/* Creative */
+	/* Creative Modem Blaster Flash56 DI5601-1 */
+	{	"DMB1032",		0	},
+	/* Creative Modem Blaster V.90 DI5660 */
+	{	"DMB2001",		0	},
+	/* E-Tech */
+	/* E-Tech CyberBULLET PC56RVP */
+	{	"ETT0002",		0	},
+	/* FUJITSU */
+	/* Fujitsu 33600 PnP-I2 R Plug & Play */
+	{	"FUJ0202",		0	},
+	/* Fujitsu FMV-FX431 Plug & Play */
+	{	"FUJ0205",		0	},
+	/* Fujitsu 33600 PnP-I4 R Plug & Play */
+	{	"FUJ0206",		0	},
+	/* Fujitsu Fax Voice 33600 PNP-I5 R Plug & Play */
+	{	"FUJ0209",		0	},
+	/* Archtek America Corp. */
+	/* Archtek SmartLink Modem 3334BT Plug & Play */
+	{	"GVC000F",		0	},
+	/* Archtek SmartLink Modem 3334BRV 33.6K Data Fax Voice */
+	{	"GVC0303",		0	},
+	/* Hayes */
+	/* Hayes Optima 288 V.34-V.FC + FAX + Voice Plug & Play */
+	{	"HAY0001",		0	},
+	/* Hayes Optima 336 V.34 + FAX + Voice PnP */
+	{	"HAY000C",		0	},
+	/* Hayes Optima 336B V.34 + FAX + Voice PnP */
+	{	"HAY000D",		0	},
+	/* Hayes Accura 56K Ext Fax Modem PnP */
+	{	"HAY5670",		0	},
+	/* Hayes Accura 56K Ext Fax Modem PnP */
+	{	"HAY5674",		0	},
+	/* Hayes Accura 56K Fax Modem PnP */
+	{	"HAY5675",		0	},
+	/* Hayes 288, V.34 + FAX */
+	{	"HAYF000",		0	},
+	/* Hayes Optima 288 V.34 + FAX + Voice, Plug & Play */
+	{	"HAYF001",		0	},
+	/* IBM */
+	/* IBM Thinkpad 701 Internal Modem Voice */
+	{	"IBM0033",		0	},
+	/* Intermec */
+	/* Intermec CV60 touchscreen port */
+	{	"PNP4972",		0	},
+	/* Intertex */
+	/* Intertex 28k8 33k6 Voice EXT PnP */
+	{	"IXDC801",		0	},
+	/* Intertex 33k6 56k Voice EXT PnP */
+	{	"IXDC901",		0	},
+	/* Intertex 28k8 33k6 Voice SP EXT PnP */
+	{	"IXDD801",		0	},
+	/* Intertex 33k6 56k Voice SP EXT PnP */
+	{	"IXDD901",		0	},
+	/* Intertex 28k8 33k6 Voice SP INT PnP */
+	{	"IXDF401",		0	},
+	/* Intertex 28k8 33k6 Voice SP EXT PnP */
+	{	"IXDF801",		0	},
+	/* Intertex 33k6 56k Voice SP EXT PnP */
+	{	"IXDF901",		0	},
+	/* Kortex International */
+	/* KORTEX 28800 Externe PnP */
+	{	"KOR4522",		0	},
+	/* KXPro 33.6 Vocal ASVD PnP */
+	{	"KORF661",		0	},
+	/* Lasat */
+	/* LASAT Internet 33600 PnP */
+	{	"LAS4040",		0	},
+	/* Lasat Safire 560 PnP */
+	{	"LAS4540",		0	},
+	/* Lasat Safire 336  PnP */
+	{	"LAS5440",		0	},
+	/* Microcom, Inc. */
+	/* Microcom TravelPorte FAST V.34 Plug & Play */
+	{	"MNP0281",		0	},
+	/* Microcom DeskPorte V.34 FAST or FAST+ Plug & Play */
+	{	"MNP0336",		0	},
+	/* Microcom DeskPorte FAST EP 28.8 Plug & Play */
+	{	"MNP0339",		0	},
+	/* Microcom DeskPorte 28.8P Plug & Play */
+	{	"MNP0342",		0	},
+	/* Microcom DeskPorte FAST ES 28.8 Plug & Play */
+	{	"MNP0500",		0	},
+	/* Microcom DeskPorte FAST ES 28.8 Plug & Play */
+	{	"MNP0501",		0	},
+	/* Microcom DeskPorte 28.8S Internal Plug & Play */
+	{	"MNP0502",		0	},
+	/* Motorola */
+	/* Motorola BitSURFR Plug & Play */
+	{	"MOT1105",		0	},
+	/* Motorola TA210 Plug & Play */
+	{	"MOT1111",		0	},
+	/* Motorola HMTA 200 (ISDN) Plug & Play */
+	{	"MOT1114",		0	},
+	/* Motorola BitSURFR Plug & Play */
+	{	"MOT1115",		0	},
+	/* Motorola Lifestyle 28.8 Internal */
+	{	"MOT1190",		0	},
+	/* Motorola V.3400 Plug & Play */
+	{	"MOT1501",		0	},
+	/* Motorola Lifestyle 28.8 V.34 Plug & Play */
+	{	"MOT1502",		0	},
+	/* Motorola Power 28.8 V.34 Plug & Play */
+	{	"MOT1505",		0	},
+	/* Motorola ModemSURFR External 28.8 Plug & Play */
+	{	"MOT1509",		0	},
+	/* Motorola Premier 33.6 Desktop Plug & Play */
+	{	"MOT150A",		0	},
+	/* Motorola VoiceSURFR 56K External PnP */
+	{	"MOT150F",		0	},
+	/* Motorola ModemSURFR 56K External PnP */
+	{	"MOT1510",		0	},
+	/* Motorola ModemSURFR 56K Internal PnP */
+	{	"MOT1550",		0	},
+	/* Motorola ModemSURFR Internal 28.8 Plug & Play */
+	{	"MOT1560",		0	},
+	/* Motorola Premier 33.6 Internal Plug & Play */
+	{	"MOT1580",		0	},
+	/* Motorola OnlineSURFR 28.8 Internal Plug & Play */
+	{	"MOT15B0",		0	},
+	/* Motorola VoiceSURFR 56K Internal PnP */
+	{	"MOT15F0",		0	},
+	/* Com 1 */
+	/*  Deskline K56 Phone System PnP */
+	{	"MVX00A1",		0	},
+	/* PC Rider K56 Phone System PnP */
+	{	"MVX00F2",		0	},
+	/* NEC 98NOTE SPEAKER PHONE FAX MODEM(33600bps) */
+	{	"nEC8241",		0	},
+	/* Pace 56 Voice Internal Plug & Play Modem */
+	{	"PMC2430",		0	},
+	/* Generic */
+	/* Generic standard PC COM port	 */
+	{	"PNP0500",		0	},
+	/* Generic 16550A-compatible COM port */
+	{	"PNP0501",		0	},
+	/* Compaq 14400 Modem */
+	{	"PNPC000",		0	},
+	/* Compaq 2400/9600 Modem */
+	{	"PNPC001",		0	},
+	/* Dial-Up Networking Serial Cable between 2 PCs */
+	{	"PNPC031",		0	},
+	/* Dial-Up Networking Parallel Cable between 2 PCs */
+	{	"PNPC032",		0	},
+	/* Standard 9600 bps Modem */
+	{	"PNPC100",		0	},
+	/* Standard 14400 bps Modem */
+	{	"PNPC101",		0	},
+	/*  Standard 28800 bps Modem*/
+	{	"PNPC102",		0	},
+	/*  Standard Modem*/
+	{	"PNPC103",		0	},
+	/*  Standard 9600 bps Modem*/
+	{	"PNPC104",		0	},
+	/*  Standard 14400 bps Modem*/
+	{	"PNPC105",		0	},
+	/*  Standard 28800 bps Modem*/
+	{	"PNPC106",		0	},
+	/*  Standard Modem */
+	{	"PNPC107",		0	},
+	/* Standard 9600 bps Modem */
+	{	"PNPC108",		0	},
+	/* Standard 14400 bps Modem */
+	{	"PNPC109",		0	},
+	/* Standard 28800 bps Modem */
+	{	"PNPC10A",		0	},
+	/* Standard Modem */
+	{	"PNPC10B",		0	},
+	/* Standard 9600 bps Modem */
+	{	"PNPC10C",		0	},
+	/* Standard 14400 bps Modem */
+	{	"PNPC10D",		0	},
+	/* Standard 28800 bps Modem */
+	{	"PNPC10E",		0	},
+	/* Standard Modem */
+	{	"PNPC10F",		0	},
+	/* Standard PCMCIA Card Modem */
+	{	"PNP2000",		0	},
+	/* Rockwell */
+	/* Modular Technology */
+	/* Rockwell 33.6 DPF Internal PnP */
+	/* Modular Technology 33.6 Internal PnP */
+	{	"ROK0030",		0	},
+	/* Kortex International */
+	/* KORTEX 14400 Externe PnP */
+	{	"ROK0100",		0	},
+	/* Rockwell 28.8 */
+	{	"ROK4120",		0	},
+	/* Viking Components, Inc */
+	/* Viking 28.8 INTERNAL Fax+Data+Voice PnP */
+	{	"ROK4920",		0	},
+	/* Rockwell */
+	/* British Telecom */
+	/* Modular Technology */
+	/* Rockwell 33.6 DPF External PnP */
+	/* BT Prologue 33.6 External PnP */
+	/* Modular Technology 33.6 External PnP */
+	{	"RSS00A0",		0	},
+	/* Viking 56K FAX INT */
+	{	"RSS0262",		0	},
+	/* K56 par,VV,Voice,Speakphone,AudioSpan,PnP */
+	{       "RSS0250",              0       },
+	/* SupraExpress 28.8 Data/Fax PnP modem */
+	{	"SUP1310",		0	},
+	/* SupraExpress 336i PnP Voice Modem */
+	{	"SUP1381",		0	},
+	/* SupraExpress 33.6 Data/Fax PnP modem */
+	{	"SUP1421",		0	},
+	/* SupraExpress 33.6 Data/Fax PnP modem */
+	{	"SUP1590",		0	},
+	/* SupraExpress 336i Sp ASVD */
+	{	"SUP1620",		0	},
+	/* SupraExpress 33.6 Data/Fax PnP modem */
+	{	"SUP1760",		0	},
+	/* SupraExpress 56i Sp Intl */
+	{	"SUP2171",		0	},
+	/* Phoebe Micro */
+	/* Phoebe Micro 33.6 Data Fax 1433VQH Plug & Play */
+	{	"TEX0011",		0	},
+	/* Archtek America Corp. */
+	/* Archtek SmartLink Modem 3334BT Plug & Play */
+	{	"UAC000F",		0	},
+	/* 3Com Corp. */
+	/* Gateway Telepath IIvi 33.6 */
+	{	"USR0000",		0	},
+	/* U.S. Robotics Sporster 33.6K Fax INT PnP */
+	{	"USR0002",		0	},
+	/*  Sportster Vi 14.4 PnP FAX Voicemail */
+	{	"USR0004",		0	},
+	/* U.S. Robotics 33.6K Voice INT PnP */
+	{	"USR0006",		0	},
+	/* U.S. Robotics 33.6K Voice EXT PnP */
+	{	"USR0007",		0	},
+	/* U.S. Robotics Courier V.Everything INT PnP */
+	{	"USR0009",		0	},
+	/* U.S. Robotics 33.6K Voice INT PnP */
+	{	"USR2002",		0	},
+	/* U.S. Robotics 56K Voice INT PnP */
+	{	"USR2070",		0	},
+	/* U.S. Robotics 56K Voice EXT PnP */
+	{	"USR2080",		0	},
+	/* U.S. Robotics 56K FAX INT */
+	{	"USR3031",		0	},
+	/* U.S. Robotics 56K FAX INT */
+	{	"USR3050",		0	},
+	/* U.S. Robotics 56K Voice INT PnP */
+	{	"USR3070",		0	},
+	/* U.S. Robotics 56K Voice EXT PnP */
+	{	"USR3080",		0	},
+	/* U.S. Robotics 56K Voice INT PnP */
+	{	"USR3090",		0	},
+	/* U.S. Robotics 56K Message  */
+	{	"USR9100",		0	},
+	/* U.S. Robotics 56K FAX EXT PnP*/
+	{	"USR9160",		0	},
+	/* U.S. Robotics 56K FAX INT PnP*/
+	{	"USR9170",		0	},
+	/* U.S. Robotics 56K Voice EXT PnP*/
+	{	"USR9180",		0	},
+	/* U.S. Robotics 56K Voice INT PnP*/
+	{	"USR9190",		0	},
+	/* Wacom tablets */
+	{	"WACFXXX",		0	},
+	/* Compaq touchscreen */
+	{       "FPI2002",              0 },
+	/* Fujitsu Stylistic touchscreens */
+	{       "FUJ02B2",              0 },
+	{       "FUJ02B3",              0 },
+	/* Fujitsu Stylistic LT touchscreens */
+	{       "FUJ02B4",              0 },
+	/* Passive Fujitsu Stylistic touchscreens */
+	{       "FUJ02B6",              0 },
+	{       "FUJ02B7",              0 },
+	{       "FUJ02B8",              0 },
+	{       "FUJ02B9",              0 },
+	{       "FUJ02BC",              0 },
+	/* Fujitsu Wacom Tablet PC device */
+	{	"FUJ02E5",		0	},
+	/* Fujitsu P-series tablet PC device */
+	{	"FUJ02E6",		0	},
+	/* Fujitsu Wacom 2FGT Tablet PC device */
+	{	"FUJ02E7",		0	},
+	/* Fujitsu Wacom 1FGT Tablet PC device */
+	{	"FUJ02E9",		0	},
+	/*
+	 * LG C1 EXPRESS DUAL (C1-PB11A3) touch screen (actually a FUJ02E6
+	 * in disguise).
+	 */
+	{	"LTS0001",		0       },
+	/* Rockwell's (PORALiNK) 33600 INT PNP */
+	{	"WCI0003",		0	},
+	/* Unknown PnP modems */
+	{	"PNPCXXX",		UNKNOWN_DEV	},
+	/* More unknown PnP modems */
+	{	"PNPDXXX",		UNKNOWN_DEV	},
+	/*
+	 * Winbond CIR port, should not be probed. We should keep track of
+	 * it to prevent the legacy serial driver from probing it.
+	 */
+	{	"WEC1022",		CIR_PORT	},
+	/*
+	 * SMSC IrCC SIR/FIR port, should not be probed by serial driver as
+	 * well so its own driver can bind to it.
+	 */
+	{	"SMCF010",		CIR_PORT	},
+	{	"",			0	}
+};
+
+MODULE_DEVICE_TABLE(pnp, pnp_dev_table);
+
+static const char *modem_names[] = {
+	"MODEM", "Modem", "modem", "FAX", "Fax", "fax",
+	"56K", "56k", "K56", "33.6", "28.8", "14.4",
+	"33,600", "28,800", "14,400", "33.600", "28.800", "14.400",
+	"33600", "28800", "14400", "V.90", "V.34", "V.32", NULL
+};
+
+static bool check_name(const char *name)
+{
+	const char **tmp;
+
+	for (tmp = modem_names; *tmp; tmp++)
+		if (strstr(name, *tmp))
+			return true;
+
+	return false;
+}
+
+static bool check_resources(struct pnp_dev *dev)
+{
+	static const resource_size_t base[] = {0x2f8, 0x3f8, 0x2e8, 0x3e8};
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(base); i++) {
+		if (pnp_possible_config(dev, IORESOURCE_IO, base[i], 8))
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Given a complete unknown PnP device, try to use some heuristics to
+ * detect modems. Currently use such heuristic set:
+ *     - dev->name or dev->bus->name must contain "modem" substring;
+ *     - device must have only one IO region (8 byte long) with base address
+ *       0x2e8, 0x3e8, 0x2f8 or 0x3f8.
+ *
+ * Such detection looks very ugly, but can detect at least some of numerous
+ * PnP modems, alternatively we must hardcode all modems in pnp_devices[]
+ * table.
+ */
+static int serial_pnp_guess_board(struct pnp_dev *dev)
+{
+	if (!(check_name(pnp_dev_name(dev)) ||
+	    (dev->card && check_name(dev->card->name))))
+		return -ENODEV;
+
+	if (check_resources(dev))
+		return 0;
+
+	return -ENODEV;
+}
+
+static int
+serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
+{
+	struct uart_8250_port uart, *port;
+	int ret, line, flags = dev_id->driver_data;
+
+	if (flags & UNKNOWN_DEV) {
+		ret = serial_pnp_guess_board(dev);
+		if (ret < 0)
+			return ret;
+	}
+
+	memset(&uart, 0, sizeof(uart));
+	if (pnp_irq_valid(dev, 0))
+		uart.port.irq = pnp_irq(dev, 0);
+	if ((flags & CIR_PORT) && pnp_port_valid(dev, 2)) {
+		uart.port.iobase = pnp_port_start(dev, 2);
+		uart.port.iotype = UPIO_PORT;
+	} else if (pnp_port_valid(dev, 0)) {
+		uart.port.iobase = pnp_port_start(dev, 0);
+		uart.port.iotype = UPIO_PORT;
+	} else if (pnp_mem_valid(dev, 0)) {
+		uart.port.mapbase = pnp_mem_start(dev, 0);
+		uart.port.iotype = UPIO_MEM;
+		uart.port.flags = UPF_IOREMAP;
+	} else
+		return -ENODEV;
+
+	dev_dbg(&dev->dev,
+		 "Setup PNP port: port %#lx, mem %#llx, irq %u, type %u\n",
+		 uart.port.iobase, (unsigned long long)uart.port.mapbase,
+		 uart.port.irq, uart.port.iotype);
+
+	if (flags & CIR_PORT) {
+		uart.port.flags |= UPF_FIXED_PORT | UPF_FIXED_TYPE;
+		uart.port.type = PORT_8250_CIR;
+	}
+
+	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
+	if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)
+		uart.port.flags |= UPF_SHARE_IRQ;
+	uart.port.uartclk = 1843200;
+	device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk);
+	uart.port.dev = &dev->dev;
+
+	line = serial8250_register_8250_port(&uart);
+	if (line < 0 || (flags & CIR_PORT))
+		return -ENODEV;
+
+	port = serial8250_get_port(line);
+	if (uart_console(&port->port))
+		dev->capabilities |= PNP_CONSOLE;
+
+	pnp_set_drvdata(dev, (void *)((long)line + 1));
+	return 0;
+}
+
+static void serial_pnp_remove(struct pnp_dev *dev)
+{
+	long line = (long)pnp_get_drvdata(dev);
+
+	dev->capabilities &= ~PNP_CONSOLE;
+	if (line)
+		serial8250_unregister_port(line - 1);
+}
+
+static int __maybe_unused serial_pnp_suspend(struct device *dev)
+{
+	long line = (long)dev_get_drvdata(dev);
+
+	if (!line)
+		return -ENODEV;
+	serial8250_suspend_port(line - 1);
+	return 0;
+}
+
+static int __maybe_unused serial_pnp_resume(struct device *dev)
+{
+	long line = (long)dev_get_drvdata(dev);
+
+	if (!line)
+		return -ENODEV;
+	serial8250_resume_port(line - 1);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(serial_pnp_pm_ops, serial_pnp_suspend, serial_pnp_resume);
+
+static struct pnp_driver serial_pnp_driver = {
+	.name		= "serial",
+	.probe		= serial_pnp_probe,
+	.remove		= serial_pnp_remove,
+	.driver         = {
+		.pm     = &serial_pnp_pm_ops,
+	},
+	.id_table	= pnp_dev_table,
+};
+
+int serial8250_pnp_init(void)
+{
+	return pnp_register_driver(&serial_pnp_driver);
+}
+
+void serial8250_pnp_exit(void)
+{
+	pnp_unregister_driver(&serial_pnp_driver);
+}
+
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
new file mode 100644
index 000000000..141627370
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -0,0 +1,3535 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Base port operations for 8250/16550-type serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *  Split from 8250_core.c, Copyright (C) 2001 Russell King.
+ *
+ * A note about mapbase / membase
+ *
+ *  mapbase is the physical address of the IO port.
+ *  membase is an 'ioremapped' cookie.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/console.h>
+#include <linux/gpio/consumer.h>
+#include <linux/sysrq.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/ratelimit.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/nmi.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
+#include <linux/ktime.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include "8250.h"
+
+/* Nuvoton NPCM timeout register */
+#define UART_NPCM_TOR          7
+#define UART_NPCM_TOIE         BIT(7)  /* Timeout Interrupt Enable */
+
+/*
+ * Debugging.
+ */
+#if 0
+#define DEBUG_AUTOCONF(fmt...)	printk(fmt)
+#else
+#define DEBUG_AUTOCONF(fmt...)	do { } while (0)
+#endif
+
+/*
+ * Here we define the default xmit fifo size used for each type of UART.
+ */
+static const struct serial8250_config uart_config[] = {
+	[PORT_UNKNOWN] = {
+		.name		= "unknown",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_8250] = {
+		.name		= "8250",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16450] = {
+		.name		= "16450",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16550] = {
+		.name		= "16550",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16550A] = {
+		.name		= "16550A",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_CIRRUS] = {
+		.name		= "Cirrus",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16650] = {
+		.name		= "ST16650",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_16650V2] = {
+		.name		= "ST16650V2",
+		.fifo_size	= 32,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
+				  UART_FCR_T_TRIG_00,
+		.rxtrig_bytes	= {8, 16, 24, 28},
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_16750] = {
+		.name		= "TI16750",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
+				  UART_FCR7_64BYTE,
+		.rxtrig_bytes	= {1, 16, 32, 56},
+		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
+	},
+	[PORT_STARTECH] = {
+		.name		= "Startech",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16C950] = {
+		.name		= "16C950/954",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
+		.rxtrig_bytes	= {16, 32, 112, 120},
+		/* UART_CAP_EFR breaks billionon CF bluetooth card. */
+		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
+	},
+	[PORT_16654] = {
+		.name		= "ST16654",
+		.fifo_size	= 64,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
+				  UART_FCR_T_TRIG_10,
+		.rxtrig_bytes	= {8, 16, 56, 60},
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_16850] = {
+		.name		= "XR16850",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_RSA] = {
+		.name		= "RSA",
+		.fifo_size	= 2048,
+		.tx_loadsz	= 2048,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_NS16550A] = {
+		.name		= "NS16550A",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_NATSEMI,
+	},
+	[PORT_XSCALE] = {
+		.name		= "XScale",
+		.fifo_size	= 32,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
+	},
+	[PORT_OCTEON] = {
+		.name		= "OCTEON",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_AR7] = {
+		.name		= "AR7",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
+		.flags		= UART_CAP_FIFO /* | UART_CAP_AFE */,
+	},
+	[PORT_U6_16550A] = {
+		.name		= "U6_16550A",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_TEGRA] = {
+		.name		= "Tegra",
+		.fifo_size	= 32,
+		.tx_loadsz	= 8,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
+				  UART_FCR_T_TRIG_01,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO | UART_CAP_RTOIE,
+	},
+	[PORT_XR17D15X] = {
+		.name		= "XR17D15X",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
+				  UART_CAP_SLEEP,
+	},
+	[PORT_XR17V35X] = {
+		.name		= "XR17V35X",
+		.fifo_size	= 256,
+		.tx_loadsz	= 256,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 |
+				  UART_FCR_T_TRIG_11,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
+				  UART_CAP_SLEEP,
+	},
+	[PORT_LPC3220] = {
+		.name		= "LPC3220",
+		.fifo_size	= 64,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
+				  UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_BRCM_TRUMANAGE] = {
+		.name		= "TruManage",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1024,
+		.flags		= UART_CAP_HFIFO,
+	},
+	[PORT_8250_CIR] = {
+		.name		= "CIR port"
+	},
+	[PORT_ALTR_16550_F32] = {
+		.name		= "Altera 16550 FIFO32",
+		.fifo_size	= 32,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 8, 16, 30},
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_ALTR_16550_F64] = {
+		.name		= "Altera 16550 FIFO64",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 16, 32, 62},
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_ALTR_16550_F128] = {
+		.name		= "Altera 16550 FIFO128",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 32, 64, 126},
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	/*
+	 * tx_loadsz is set to 63-bytes instead of 64-bytes to implement
+	 * workaround of errata A-008006 which states that tx_loadsz should
+	 * be configured less than Maximum supported fifo bytes.
+	 */
+	[PORT_16550A_FSL64] = {
+		.name		= "16550A_FSL64",
+		.fifo_size	= 64,
+		.tx_loadsz	= 63,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
+				  UART_FCR7_64BYTE,
+		.flags		= UART_CAP_FIFO | UART_CAP_NOTEMT,
+	},
+	[PORT_RT2880] = {
+		.name		= "Palmchip BK-3103",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_DA830] = {
+		.name		= "TI DA8xx/66AK2x",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
+				  UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_MTK_BTIF] = {
+		.name		= "MediaTek BTIF",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO |
+				  UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_NPCM] = {
+		.name		= "Nuvoton 16550",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
+				  UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_SUNIX] = {
+		.name		= "Sunix",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 32, 64, 112},
+		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
+	},
+	[PORT_ASPEED_VUART] = {
+		.name		= "ASPEED VUART",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_MCHP16550A] = {
+		.name           = "MCHP16550A",
+		.fifo_size      = 256,
+		.tx_loadsz      = 256,
+		.fcr            = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
+		.rxtrig_bytes   = {2, 66, 130, 194},
+		.flags          = UART_CAP_FIFO,
+	},
+	[PORT_BCM7271] = {
+		.name		= "Broadcom BCM7271 UART",
+		.fifo_size	= 32,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
+		.rxtrig_bytes	= {1, 8, 16, 30},
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+};
+
+/* Uart divisor latch read */
+static u32 default_serial_dl_read(struct uart_8250_port *up)
+{
+	/* Assign these in pieces to truncate any bits above 7.  */
+	unsigned char dll = serial_in(up, UART_DLL);
+	unsigned char dlm = serial_in(up, UART_DLM);
+
+	return dll | dlm << 8;
+}
+
+/* Uart divisor latch write */
+static void default_serial_dl_write(struct uart_8250_port *up, u32 value)
+{
+	serial_out(up, UART_DLL, value & 0xff);
+	serial_out(up, UART_DLM, value >> 8 & 0xff);
+}
+
+static unsigned int hub6_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	outb(p->hub6 - 1 + offset, p->iobase);
+	return inb(p->iobase + 1);
+}
+
+static void hub6_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	outb(p->hub6 - 1 + offset, p->iobase);
+	outb(value, p->iobase + 1);
+}
+
+static unsigned int mem_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return readb(p->membase + offset);
+}
+
+static void mem_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	writeb(value, p->membase + offset);
+}
+
+static void mem16_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	writew(value, p->membase + offset);
+}
+
+static unsigned int mem16_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return readw(p->membase + offset);
+}
+
+static void mem32_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	writel(value, p->membase + offset);
+}
+
+static unsigned int mem32_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return readl(p->membase + offset);
+}
+
+static void mem32be_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	iowrite32be(value, p->membase + offset);
+}
+
+static unsigned int mem32be_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return ioread32be(p->membase + offset);
+}
+
+static unsigned int io_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return inb(p->iobase + offset);
+}
+
+static void io_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	outb(value, p->iobase + offset);
+}
+
+static int serial8250_default_handle_irq(struct uart_port *port);
+
+static void set_io_from_upio(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+
+	up->dl_read = default_serial_dl_read;
+	up->dl_write = default_serial_dl_write;
+
+	switch (p->iotype) {
+	case UPIO_HUB6:
+		p->serial_in = hub6_serial_in;
+		p->serial_out = hub6_serial_out;
+		break;
+
+	case UPIO_MEM:
+		p->serial_in = mem_serial_in;
+		p->serial_out = mem_serial_out;
+		break;
+
+	case UPIO_MEM16:
+		p->serial_in = mem16_serial_in;
+		p->serial_out = mem16_serial_out;
+		break;
+
+	case UPIO_MEM32:
+		p->serial_in = mem32_serial_in;
+		p->serial_out = mem32_serial_out;
+		break;
+
+	case UPIO_MEM32BE:
+		p->serial_in = mem32be_serial_in;
+		p->serial_out = mem32be_serial_out;
+		break;
+
+	default:
+		p->serial_in = io_serial_in;
+		p->serial_out = io_serial_out;
+		break;
+	}
+	/* Remember loaded iotype */
+	up->cur_iotype = p->iotype;
+	p->handle_irq = serial8250_default_handle_irq;
+}
+
+static void
+serial_port_out_sync(struct uart_port *p, int offset, int value)
+{
+	switch (p->iotype) {
+	case UPIO_MEM:
+	case UPIO_MEM16:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_AU:
+		p->serial_out(p, offset, value);
+		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
+		break;
+	default:
+		p->serial_out(p, offset, value);
+	}
+}
+
+/*
+ * FIFO support.
+ */
+static void serial8250_clear_fifos(struct uart_8250_port *p)
+{
+	if (p->capabilities & UART_CAP_FIFO) {
+		serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO |
+			       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+		serial_out(p, UART_FCR, 0);
+	}
+}
+
+static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t);
+static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t);
+
+void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
+{
+	serial8250_clear_fifos(p);
+	serial_out(p, UART_FCR, p->fcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
+
+void serial8250_rpm_get(struct uart_8250_port *p)
+{
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+	pm_runtime_get_sync(p->port.dev);
+}
+EXPORT_SYMBOL_GPL(serial8250_rpm_get);
+
+void serial8250_rpm_put(struct uart_8250_port *p)
+{
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+	pm_runtime_mark_last_busy(p->port.dev);
+	pm_runtime_put_autosuspend(p->port.dev);
+}
+EXPORT_SYMBOL_GPL(serial8250_rpm_put);
+
+/**
+ *	serial8250_em485_init() - put uart_8250_port into rs485 emulating
+ *	@p:	uart_8250_port port instance
+ *
+ *	The function is used to start rs485 software emulating on the
+ *	&struct uart_8250_port* @p. Namely, RTS is switched before/after
+ *	transmission. The function is idempotent, so it is safe to call it
+ *	multiple times.
+ *
+ *	The caller MUST enable interrupt on empty shift register before
+ *	calling serial8250_em485_init(). This interrupt is not a part of
+ *	8250 standard, but implementation defined.
+ *
+ *	The function is supposed to be called from .rs485_config callback
+ *	or from any other callback protected with p->port.lock spinlock.
+ *
+ *	See also serial8250_em485_destroy()
+ *
+ *	Return 0 - success, -errno - otherwise
+ */
+static int serial8250_em485_init(struct uart_8250_port *p)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&p->port.lock);
+
+	if (p->em485)
+		goto deassert_rts;
+
+	p->em485 = kmalloc(sizeof(struct uart_8250_em485), GFP_ATOMIC);
+	if (!p->em485)
+		return -ENOMEM;
+
+	hrtimer_init(&p->em485->stop_tx_timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL);
+	hrtimer_init(&p->em485->start_tx_timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL);
+	p->em485->stop_tx_timer.function = &serial8250_em485_handle_stop_tx;
+	p->em485->start_tx_timer.function = &serial8250_em485_handle_start_tx;
+	p->em485->port = p;
+	p->em485->active_timer = NULL;
+	p->em485->tx_stopped = true;
+
+deassert_rts:
+	if (p->em485->tx_stopped)
+		p->rs485_stop_tx(p);
+
+	return 0;
+}
+
+/**
+ *	serial8250_em485_destroy() - put uart_8250_port into normal state
+ *	@p:	uart_8250_port port instance
+ *
+ *	The function is used to stop rs485 software emulating on the
+ *	&struct uart_8250_port* @p. The function is idempotent, so it is safe to
+ *	call it multiple times.
+ *
+ *	The function is supposed to be called from .rs485_config callback
+ *	or from any other callback protected with p->port.lock spinlock.
+ *
+ *	See also serial8250_em485_init()
+ */
+void serial8250_em485_destroy(struct uart_8250_port *p)
+{
+	if (!p->em485)
+		return;
+
+	hrtimer_cancel(&p->em485->start_tx_timer);
+	hrtimer_cancel(&p->em485->stop_tx_timer);
+
+	kfree(p->em485);
+	p->em485 = NULL;
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_destroy);
+
+struct serial_rs485 serial8250_em485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+		 SER_RS485_TERMINATE_BUS | SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+EXPORT_SYMBOL_GPL(serial8250_em485_supported);
+
+/**
+ * serial8250_em485_config() - generic ->rs485_config() callback
+ * @port: uart port
+ * @termios: termios structure
+ * @rs485: rs485 settings
+ *
+ * Generic callback usable by 8250 uart drivers to activate rs485 settings
+ * if the uart is incapable of driving RTS as a Transmit Enable signal in
+ * hardware, relying on software emulation instead.
+ */
+int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
+			    struct serial_rs485 *rs485)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* pick sane settings if the user hasn't */
+	if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+	    !!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
+		rs485->flags |= SER_RS485_RTS_ON_SEND;
+		rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
+	}
+
+	/*
+	 * Both serial8250_em485_init() and serial8250_em485_destroy()
+	 * are idempotent.
+	 */
+	if (rs485->flags & SER_RS485_ENABLED)
+		return serial8250_em485_init(up);
+
+	serial8250_em485_destroy(up);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_config);
+
+/*
+ * These two wrappers ensure that enable_runtime_pm_tx() can be called more than
+ * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
+ * empty and the HW can idle again.
+ */
+void serial8250_rpm_get_tx(struct uart_8250_port *p)
+{
+	unsigned char rpm_active;
+
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+
+	rpm_active = xchg(&p->rpm_tx_active, 1);
+	if (rpm_active)
+		return;
+	pm_runtime_get_sync(p->port.dev);
+}
+EXPORT_SYMBOL_GPL(serial8250_rpm_get_tx);
+
+void serial8250_rpm_put_tx(struct uart_8250_port *p)
+{
+	unsigned char rpm_active;
+
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+
+	rpm_active = xchg(&p->rpm_tx_active, 0);
+	if (!rpm_active)
+		return;
+	pm_runtime_mark_last_busy(p->port.dev);
+	pm_runtime_put_autosuspend(p->port.dev);
+}
+EXPORT_SYMBOL_GPL(serial8250_rpm_put_tx);
+
+/*
+ * IER sleep support.  UARTs which have EFRs need the "extended
+ * capability" bit enabled.  Note that on XR16C850s, we need to
+ * reset LCR to write to IER.
+ */
+static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
+{
+	unsigned char lcr = 0, efr = 0;
+
+	serial8250_rpm_get(p);
+
+	if (p->capabilities & UART_CAP_SLEEP) {
+		/* Synchronize UART_IER access against the console. */
+		spin_lock_irq(&p->port.lock);
+		if (p->capabilities & UART_CAP_EFR) {
+			lcr = serial_in(p, UART_LCR);
+			efr = serial_in(p, UART_EFR);
+			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
+			serial_out(p, UART_EFR, UART_EFR_ECB);
+			serial_out(p, UART_LCR, 0);
+		}
+		serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
+		if (p->capabilities & UART_CAP_EFR) {
+			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
+			serial_out(p, UART_EFR, efr);
+			serial_out(p, UART_LCR, lcr);
+		}
+		spin_unlock_irq(&p->port.lock);
+	}
+
+	serial8250_rpm_put(p);
+}
+
+static void serial8250_clear_IER(struct uart_8250_port *up)
+{
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+/*
+ * Attempts to turn on the RSA FIFO.  Returns zero on failure.
+ * We set the port uart clock rate if we succeed.
+ */
+static int __enable_rsa(struct uart_8250_port *up)
+{
+	unsigned char mode;
+	int result;
+
+	mode = serial_in(up, UART_RSA_MSR);
+	result = mode & UART_RSA_MSR_FIFO;
+
+	if (!result) {
+		serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
+		mode = serial_in(up, UART_RSA_MSR);
+		result = mode & UART_RSA_MSR_FIFO;
+	}
+
+	if (result)
+		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
+
+	return result;
+}
+
+static void enable_rsa(struct uart_8250_port *up)
+{
+	if (up->port.type == PORT_RSA) {
+		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
+			spin_lock_irq(&up->port.lock);
+			__enable_rsa(up);
+			spin_unlock_irq(&up->port.lock);
+		}
+		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
+			serial_out(up, UART_RSA_FRR, 0);
+	}
+}
+
+/*
+ * Attempts to turn off the RSA FIFO.  Returns zero on failure.
+ * It is unknown why interrupts were disabled in here.  However,
+ * the caller is expected to preserve this behaviour by grabbing
+ * the spinlock before calling this function.
+ */
+static void disable_rsa(struct uart_8250_port *up)
+{
+	unsigned char mode;
+	int result;
+
+	if (up->port.type == PORT_RSA &&
+	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
+		spin_lock_irq(&up->port.lock);
+
+		mode = serial_in(up, UART_RSA_MSR);
+		result = !(mode & UART_RSA_MSR_FIFO);
+
+		if (!result) {
+			serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
+			mode = serial_in(up, UART_RSA_MSR);
+			result = !(mode & UART_RSA_MSR_FIFO);
+		}
+
+		if (result)
+			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
+		spin_unlock_irq(&up->port.lock);
+	}
+}
+#endif /* CONFIG_SERIAL_8250_RSA */
+
+/*
+ * This is a quickie test to see how big the FIFO is.
+ * It doesn't work at all the time, more's the pity.
+ */
+static int size_fifo(struct uart_8250_port *up)
+{
+	unsigned char old_fcr, old_mcr, old_lcr;
+	u32 old_dl;
+	int count;
+
+	old_lcr = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, 0);
+	old_fcr = serial_in(up, UART_FCR);
+	old_mcr = serial8250_in_MCR(up);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+		    UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial8250_out_MCR(up, UART_MCR_LOOP);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	old_dl = serial_dl_read(up);
+	serial_dl_write(up, 0x0001);
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
+	for (count = 0; count < 256; count++)
+		serial_out(up, UART_TX, count);
+	mdelay(20);/* FIXME - schedule_timeout */
+	for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) &&
+	     (count < 256); count++)
+		serial_in(up, UART_RX);
+	serial_out(up, UART_FCR, old_fcr);
+	serial8250_out_MCR(up, old_mcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_dl_write(up, old_dl);
+	serial_out(up, UART_LCR, old_lcr);
+
+	return count;
+}
+
+/*
+ * Read UART ID using the divisor method - set DLL and DLM to zero
+ * and the revision will be in DLL and device type in DLM.  We
+ * preserve the device state across this.
+ */
+static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
+{
+	unsigned char old_lcr;
+	unsigned int id, old_dl;
+
+	old_lcr = serial_in(p, UART_LCR);
+	serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A);
+	old_dl = serial_dl_read(p);
+	serial_dl_write(p, 0);
+	id = serial_dl_read(p);
+	serial_dl_write(p, old_dl);
+
+	serial_out(p, UART_LCR, old_lcr);
+
+	return id;
+}
+
+/*
+ * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
+ * When this function is called we know it is at least a StarTech
+ * 16650 V2, but it might be one of several StarTech UARTs, or one of
+ * its clones.  (We treat the broken original StarTech 16650 V1 as a
+ * 16550, and why not?  Startech doesn't seem to even acknowledge its
+ * existence.)
+ *
+ * What evil have men's minds wrought...
+ */
+static void autoconfig_has_efr(struct uart_8250_port *up)
+{
+	unsigned int id1, id2, id3, rev;
+
+	/*
+	 * Everything with an EFR has SLEEP
+	 */
+	up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
+
+	/*
+	 * First we check to see if it's an Oxford Semiconductor UART.
+	 *
+	 * If we have to do this here because some non-National
+	 * Semiconductor clone chips lock up if you try writing to the
+	 * LSR register (which serial_icr_read does)
+	 */
+
+	/*
+	 * Check for Oxford Semiconductor 16C950.
+	 *
+	 * EFR [4] must be set else this test fails.
+	 *
+	 * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
+	 * claims that it's needed for 952 dual UART's (which are not
+	 * recommended for new designs).
+	 */
+	up->acr = 0;
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, UART_EFR_ECB);
+	serial_out(up, UART_LCR, 0x00);
+	id1 = serial_icr_read(up, UART_ID1);
+	id2 = serial_icr_read(up, UART_ID2);
+	id3 = serial_icr_read(up, UART_ID3);
+	rev = serial_icr_read(up, UART_REV);
+
+	DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
+
+	if (id1 == 0x16 && id2 == 0xC9 &&
+	    (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
+		up->port.type = PORT_16C950;
+
+		/*
+		 * Enable work around for the Oxford Semiconductor 952 rev B
+		 * chip which causes it to seriously miscalculate baud rates
+		 * when DLL is 0.
+		 */
+		if (id3 == 0x52 && rev == 0x01)
+			up->bugs |= UART_BUG_QUOT;
+		return;
+	}
+
+	/*
+	 * We check for a XR16C850 by setting DLL and DLM to 0, and then
+	 * reading back DLL and DLM.  The chip type depends on the DLM
+	 * value read back:
+	 *  0x10 - XR16C850 and the DLL contains the chip revision.
+	 *  0x12 - XR16C2850.
+	 *  0x14 - XR16C854.
+	 */
+	id1 = autoconfig_read_divisor_id(up);
+	DEBUG_AUTOCONF("850id=%04x ", id1);
+
+	id2 = id1 >> 8;
+	if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
+		up->port.type = PORT_16850;
+		return;
+	}
+
+	/*
+	 * It wasn't an XR16C850.
+	 *
+	 * We distinguish between the '654 and the '650 by counting
+	 * how many bytes are in the FIFO.  I'm using this for now,
+	 * since that's the technique that was sent to me in the
+	 * serial driver update, but I'm not convinced this works.
+	 * I've had problems doing this in the past.  -TYT
+	 */
+	if (size_fifo(up) == 64)
+		up->port.type = PORT_16654;
+	else
+		up->port.type = PORT_16650V2;
+}
+
+/*
+ * We detected a chip without a FIFO.  Only two fall into
+ * this category - the original 8250 and the 16450.  The
+ * 16450 has a scratch register (accessible with LCR=0)
+ */
+static void autoconfig_8250(struct uart_8250_port *up)
+{
+	unsigned char scratch, status1, status2;
+
+	up->port.type = PORT_8250;
+
+	scratch = serial_in(up, UART_SCR);
+	serial_out(up, UART_SCR, 0xa5);
+	status1 = serial_in(up, UART_SCR);
+	serial_out(up, UART_SCR, 0x5a);
+	status2 = serial_in(up, UART_SCR);
+	serial_out(up, UART_SCR, scratch);
+
+	if (status1 == 0xa5 && status2 == 0x5a)
+		up->port.type = PORT_16450;
+}
+
+static int broken_efr(struct uart_8250_port *up)
+{
+	/*
+	 * Exar ST16C2550 "A2" devices incorrectly detect as
+	 * having an EFR, and report an ID of 0x0201.  See
+	 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html
+	 */
+	if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * We know that the chip has FIFOs.  Does it have an EFR?  The
+ * EFR is located in the same register position as the IIR and
+ * we know the top two bits of the IIR are currently set.  The
+ * EFR should contain zero.  Try to read the EFR.
+ */
+static void autoconfig_16550a(struct uart_8250_port *up)
+{
+	unsigned char status1, status2;
+	unsigned int iersave;
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	up->port.type = PORT_16550A;
+	up->capabilities |= UART_CAP_FIFO;
+
+	if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS) &&
+	    !(up->port.flags & UPF_FULL_PROBE))
+		return;
+
+	/*
+	 * Check for presence of the EFR when DLAB is set.
+	 * Only ST16C650V1 UARTs pass this test.
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	if (serial_in(up, UART_EFR) == 0) {
+		serial_out(up, UART_EFR, 0xA8);
+		if (serial_in(up, UART_EFR) != 0) {
+			DEBUG_AUTOCONF("EFRv1 ");
+			up->port.type = PORT_16650;
+			up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
+		} else {
+			serial_out(up, UART_LCR, 0);
+			serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+				   UART_FCR7_64BYTE);
+			status1 = serial_in(up, UART_IIR) & (UART_IIR_64BYTE_FIFO |
+							     UART_IIR_FIFO_ENABLED);
+			serial_out(up, UART_FCR, 0);
+			serial_out(up, UART_LCR, 0);
+
+			if (status1 == (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED))
+				up->port.type = PORT_16550A_FSL64;
+			else
+				DEBUG_AUTOCONF("Motorola 8xxx DUART ");
+		}
+		serial_out(up, UART_EFR, 0);
+		return;
+	}
+
+	/*
+	 * Maybe it requires 0xbf to be written to the LCR.
+	 * (other ST16C650V2 UARTs, TI16C752A, etc)
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
+		DEBUG_AUTOCONF("EFRv2 ");
+		autoconfig_has_efr(up);
+		return;
+	}
+
+	/*
+	 * Check for a National Semiconductor SuperIO chip.
+	 * Attempt to switch to bank 2, read the value of the LOOP bit
+	 * from EXCR1. Switch back to bank 0, change it in MCR. Then
+	 * switch back to bank 2, read it from EXCR1 again and check
+	 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
+	 */
+	serial_out(up, UART_LCR, 0);
+	status1 = serial8250_in_MCR(up);
+	serial_out(up, UART_LCR, 0xE0);
+	status2 = serial_in(up, 0x02); /* EXCR1 */
+
+	if (!((status2 ^ status1) & UART_MCR_LOOP)) {
+		serial_out(up, UART_LCR, 0);
+		serial8250_out_MCR(up, status1 ^ UART_MCR_LOOP);
+		serial_out(up, UART_LCR, 0xE0);
+		status2 = serial_in(up, 0x02); /* EXCR1 */
+		serial_out(up, UART_LCR, 0);
+		serial8250_out_MCR(up, status1);
+
+		if ((status2 ^ status1) & UART_MCR_LOOP) {
+			unsigned short quot;
+
+			serial_out(up, UART_LCR, 0xE0);
+
+			quot = serial_dl_read(up);
+			quot <<= 3;
+
+			if (ns16550a_goto_highspeed(up))
+				serial_dl_write(up, quot);
+
+			serial_out(up, UART_LCR, 0);
+
+			up->port.uartclk = 921600*16;
+			up->port.type = PORT_NS16550A;
+			up->capabilities |= UART_NATSEMI;
+			return;
+		}
+	}
+
+	/*
+	 * No EFR.  Try to detect a TI16750, which only sets bit 5 of
+	 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
+	 * Try setting it with and without DLAB set.  Cheap clones
+	 * set bit 5 without DLAB set.
+	 */
+	serial_out(up, UART_LCR, 0);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+	status1 = serial_in(up, UART_IIR) & (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+	status2 = serial_in(up, UART_IIR) & (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+
+	serial_out(up, UART_LCR, 0);
+
+	DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
+
+	if (status1 == UART_IIR_FIFO_ENABLED_16550A &&
+	    status2 == (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED_16550A)) {
+		up->port.type = PORT_16750;
+		up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
+		return;
+	}
+
+	/*
+	 * Try writing and reading the UART_IER_UUE bit (b6).
+	 * If it works, this is probably one of the Xscale platform's
+	 * internal UARTs.
+	 * We're going to explicitly set the UUE bit to 0 before
+	 * trying to write and read a 1 just to make sure it's not
+	 * already a 1 and maybe locked there before we even start.
+	 */
+	iersave = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, iersave & ~UART_IER_UUE);
+	if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
+		/*
+		 * OK it's in a known zero state, try writing and reading
+		 * without disturbing the current state of the other bits.
+		 */
+		serial_out(up, UART_IER, iersave | UART_IER_UUE);
+		if (serial_in(up, UART_IER) & UART_IER_UUE) {
+			/*
+			 * It's an Xscale.
+			 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
+			 */
+			DEBUG_AUTOCONF("Xscale ");
+			up->port.type = PORT_XSCALE;
+			up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
+			return;
+		}
+	} else {
+		/*
+		 * If we got here we couldn't force the IER_UUE bit to 0.
+		 * Log it and continue.
+		 */
+		DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
+	}
+	serial_out(up, UART_IER, iersave);
+
+	/*
+	 * We distinguish between 16550A and U6 16550A by counting
+	 * how many bytes are in the FIFO.
+	 */
+	if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
+		up->port.type = PORT_U6_16550A;
+		up->capabilities |= UART_CAP_AFE;
+	}
+}
+
+/*
+ * This routine is called by rs_init() to initialize a specific serial
+ * port.  It determines what type of UART chip this serial port is
+ * using: 8250, 16450, 16550, 16550A.  The important question is
+ * whether or not this UART is a 16550A or not, since this will
+ * determine whether or not we can use its FIFO features or not.
+ */
+static void autoconfig(struct uart_8250_port *up)
+{
+	unsigned char status1, scratch, scratch2, scratch3;
+	unsigned char save_lcr, save_mcr;
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int old_capabilities;
+
+	if (!port->iobase && !port->mapbase && !port->membase)
+		return;
+
+	DEBUG_AUTOCONF("%s: autoconf (0x%04lx, 0x%p): ",
+		       port->name, port->iobase, port->membase);
+
+	/*
+	 * We really do need global IRQs disabled here - we're going to
+	 * be frobbing the chips IRQ enable register to see if it exists.
+	 *
+	 * Synchronize UART_IER access against the console.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+
+	up->capabilities = 0;
+	up->bugs = 0;
+
+	if (!(port->flags & UPF_BUGGY_UART)) {
+		/*
+		 * Do a simple existence test first; if we fail this,
+		 * there's no point trying anything else.
+		 *
+		 * 0x80 is used as a nonsense port to prevent against
+		 * false positives due to ISA bus float.  The
+		 * assumption is that 0x80 is a non-existent port;
+		 * which should be safe since include/asm/io.h also
+		 * makes this assumption.
+		 *
+		 * Note: this is safe as long as MCR bit 4 is clear
+		 * and the device is in "PC" mode.
+		 */
+		scratch = serial_in(up, UART_IER);
+		serial_out(up, UART_IER, 0);
+#ifdef __i386__
+		outb(0xff, 0x080);
+#endif
+		/*
+		 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
+		 * 16C754B) allow only to modify them if an EFR bit is set.
+		 */
+		scratch2 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
+		serial_out(up, UART_IER, UART_IER_ALL_INTR);
+#ifdef __i386__
+		outb(0, 0x080);
+#endif
+		scratch3 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
+		serial_out(up, UART_IER, scratch);
+		if (scratch2 != 0 || scratch3 != UART_IER_ALL_INTR) {
+			/*
+			 * We failed; there's nothing here
+			 */
+			spin_unlock_irqrestore(&port->lock, flags);
+			DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
+				       scratch2, scratch3);
+			goto out;
+		}
+	}
+
+	save_mcr = serial8250_in_MCR(up);
+	save_lcr = serial_in(up, UART_LCR);
+
+	/*
+	 * Check to see if a UART is really there.  Certain broken
+	 * internal modems based on the Rockwell chipset fail this
+	 * test, because they apparently don't implement the loopback
+	 * test mode.  So this test is skipped on the COM 1 through
+	 * COM 4 ports.  This *should* be safe, since no board
+	 * manufacturer would be stupid enough to design a board
+	 * that conflicts with COM 1-4 --- we hope!
+	 */
+	if (!(port->flags & UPF_SKIP_TEST)) {
+		serial8250_out_MCR(up, UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_RTS);
+		status1 = serial_in(up, UART_MSR) & UART_MSR_STATUS_BITS;
+		serial8250_out_MCR(up, save_mcr);
+		if (status1 != (UART_MSR_DCD | UART_MSR_CTS)) {
+			spin_unlock_irqrestore(&port->lock, flags);
+			DEBUG_AUTOCONF("LOOP test failed (%02x) ",
+				       status1);
+			goto out;
+		}
+	}
+
+	/*
+	 * We're pretty sure there's a port here.  Lets find out what
+	 * type of port it is.  The IIR top two bits allows us to find
+	 * out if it's 8250 or 16450, 16550, 16550A or later.  This
+	 * determines what we test for next.
+	 *
+	 * We also initialise the EFR (if any) to zero for later.  The
+	 * EFR occupies the same register location as the FCR and IIR.
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, 0);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+
+	switch (serial_in(up, UART_IIR) & UART_IIR_FIFO_ENABLED) {
+	case UART_IIR_FIFO_ENABLED_8250:
+		autoconfig_8250(up);
+		break;
+	case UART_IIR_FIFO_ENABLED_16550:
+		port->type = PORT_16550;
+		break;
+	case UART_IIR_FIFO_ENABLED_16550A:
+		autoconfig_16550a(up);
+		break;
+	default:
+		port->type = PORT_UNKNOWN;
+		break;
+	}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * Only probe for RSA ports if we got the region.
+	 */
+	if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA &&
+	    __enable_rsa(up))
+		port->type = PORT_RSA;
+#endif
+
+	serial_out(up, UART_LCR, save_lcr);
+
+	port->fifosize = uart_config[up->port.type].fifo_size;
+	old_capabilities = up->capabilities;
+	up->capabilities = uart_config[port->type].flags;
+	up->tx_loadsz = uart_config[port->type].tx_loadsz;
+
+	if (port->type == PORT_UNKNOWN)
+		goto out_unlock;
+
+	/*
+	 * Reset the UART.
+	 */
+#ifdef CONFIG_SERIAL_8250_RSA
+	if (port->type == PORT_RSA)
+		serial_out(up, UART_RSA_FRR, 0);
+#endif
+	serial8250_out_MCR(up, save_mcr);
+	serial8250_clear_fifos(up);
+	serial_in(up, UART_RX);
+	serial8250_clear_IER(up);
+
+out_unlock:
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/*
+	 * Check if the device is a Fintek F81216A
+	 */
+	if (port->type == PORT_16550A && port->iotype == UPIO_PORT)
+		fintek_8250_probe(up);
+
+	if (up->capabilities != old_capabilities) {
+		dev_warn(port->dev, "detected caps %08x should be %08x\n",
+			 old_capabilities, up->capabilities);
+	}
+out:
+	DEBUG_AUTOCONF("iir=%d ", scratch);
+	DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name);
+}
+
+static void autoconfig_irq(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	unsigned char save_mcr, save_ier;
+	unsigned char save_ICP = 0;
+	unsigned int ICP = 0;
+	unsigned long irqs;
+	int irq;
+
+	if (port->flags & UPF_FOURPORT) {
+		ICP = (port->iobase & 0xfe0) | 0x1f;
+		save_ICP = inb_p(ICP);
+		outb_p(0x80, ICP);
+		inb_p(ICP);
+	}
+
+	if (uart_console(port))
+		console_lock();
+
+	/* forget possible initially masked and pending IRQ */
+	probe_irq_off(probe_irq_on());
+	save_mcr = serial8250_in_MCR(up);
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irq(&port->lock);
+	save_ier = serial_in(up, UART_IER);
+	spin_unlock_irq(&port->lock);
+	serial8250_out_MCR(up, UART_MCR_OUT1 | UART_MCR_OUT2);
+
+	irqs = probe_irq_on();
+	serial8250_out_MCR(up, 0);
+	udelay(10);
+	if (port->flags & UPF_FOURPORT) {
+		serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
+	} else {
+		serial8250_out_MCR(up,
+			UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
+	}
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irq(&port->lock);
+	serial_out(up, UART_IER, UART_IER_ALL_INTR);
+	spin_unlock_irq(&port->lock);
+	serial_in(up, UART_LSR);
+	serial_in(up, UART_RX);
+	serial_in(up, UART_IIR);
+	serial_in(up, UART_MSR);
+	serial_out(up, UART_TX, 0xFF);
+	udelay(20);
+	irq = probe_irq_off(irqs);
+
+	serial8250_out_MCR(up, save_mcr);
+	/* Synchronize UART_IER access against the console. */
+	spin_lock_irq(&port->lock);
+	serial_out(up, UART_IER, save_ier);
+	spin_unlock_irq(&port->lock);
+
+	if (port->flags & UPF_FOURPORT)
+		outb_p(save_ICP, ICP);
+
+	if (uart_console(port))
+		console_unlock();
+
+	port->irq = (irq > 0) ? irq : 0;
+}
+
+static void serial8250_stop_rx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&port->lock);
+
+	serial8250_rpm_get(up);
+
+	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_port_out(port, UART_IER, up->ier);
+
+	serial8250_rpm_put(up);
+}
+
+/**
+ * serial8250_em485_stop_tx() - generic ->rs485_stop_tx() callback
+ * @p: uart 8250 port
+ *
+ * Generic callback usable by 8250 uart drivers to stop rs485 transmission.
+ */
+void serial8250_em485_stop_tx(struct uart_8250_port *p)
+{
+	unsigned char mcr = serial8250_in_MCR(p);
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&p->port.lock);
+
+	if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
+		mcr |= UART_MCR_RTS;
+	else
+		mcr &= ~UART_MCR_RTS;
+	serial8250_out_MCR(p, mcr);
+
+	/*
+	 * Empty the RX FIFO, we are not interested in anything
+	 * received during the half-duplex transmission.
+	 * Enable previously disabled RX interrupts.
+	 */
+	if (!(p->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
+		serial8250_clear_and_reinit_fifos(p);
+
+		p->ier |= UART_IER_RLSI | UART_IER_RDI;
+		serial_port_out(&p->port, UART_IER, p->ier);
+	}
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx);
+
+static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t)
+{
+	struct uart_8250_em485 *em485 = container_of(t, struct uart_8250_em485,
+			stop_tx_timer);
+	struct uart_8250_port *p = em485->port;
+	unsigned long flags;
+
+	serial8250_rpm_get(p);
+	spin_lock_irqsave(&p->port.lock, flags);
+	if (em485->active_timer == &em485->stop_tx_timer) {
+		p->rs485_stop_tx(p);
+		em485->active_timer = NULL;
+		em485->tx_stopped = true;
+	}
+	spin_unlock_irqrestore(&p->port.lock, flags);
+	serial8250_rpm_put(p);
+
+	return HRTIMER_NORESTART;
+}
+
+static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
+{
+	hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL);
+}
+
+static void __stop_tx_rs485(struct uart_8250_port *p, u64 stop_delay)
+{
+	struct uart_8250_em485 *em485 = p->em485;
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&p->port.lock);
+
+	stop_delay += (u64)p->port.rs485.delay_rts_after_send * NSEC_PER_MSEC;
+
+	/*
+	 * rs485_stop_tx() is going to set RTS according to config
+	 * AND flush RX FIFO if required.
+	 */
+	if (stop_delay > 0) {
+		em485->active_timer = &em485->stop_tx_timer;
+		hrtimer_start(&em485->stop_tx_timer, ns_to_ktime(stop_delay), HRTIMER_MODE_REL);
+	} else {
+		p->rs485_stop_tx(p);
+		em485->active_timer = NULL;
+		em485->tx_stopped = true;
+	}
+}
+
+static inline void __stop_tx(struct uart_8250_port *p)
+{
+	struct uart_8250_em485 *em485 = p->em485;
+
+	if (em485) {
+		u16 lsr = serial_lsr_in(p);
+		u64 stop_delay = 0;
+
+		if (!(lsr & UART_LSR_THRE))
+			return;
+		/*
+		 * To provide required timing and allow FIFO transfer,
+		 * __stop_tx_rs485() must be called only when both FIFO and
+		 * shift register are empty. The device driver should either
+		 * enable interrupt on TEMT or set UART_CAP_NOTEMT that will
+		 * enlarge stop_tx_timer by the tx time of one frame to cover
+		 * for emptying of the shift register.
+		 */
+		if (!(lsr & UART_LSR_TEMT)) {
+			if (!(p->capabilities & UART_CAP_NOTEMT))
+				return;
+			/*
+			 * RTS might get deasserted too early with the normal
+			 * frame timing formula. It seems to suggest THRE might
+			 * get asserted already during tx of the stop bit
+			 * rather than after it is fully sent.
+			 * Roughly estimate 1 extra bit here with / 7.
+			 */
+			stop_delay = p->port.frame_time + DIV_ROUND_UP(p->port.frame_time, 7);
+		}
+
+		__stop_tx_rs485(p, stop_delay);
+	}
+
+	if (serial8250_clear_THRI(p))
+		serial8250_rpm_put_tx(p);
+}
+
+static void serial8250_stop_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_rpm_get(up);
+	__stop_tx(up);
+
+	/*
+	 * We really want to stop the transmitter from sending.
+	 */
+	if (port->type == PORT_16C950) {
+		up->acr |= UART_ACR_TXDIS;
+		serial_icr_write(up, UART_ACR, up->acr);
+	}
+	serial8250_rpm_put(up);
+}
+
+static inline void __start_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	if (up->dma && !up->dma->tx_dma(up))
+		return;
+
+	if (serial8250_set_THRI(up)) {
+		if (up->bugs & UART_BUG_TXEN) {
+			u16 lsr = serial_lsr_in(up);
+
+			if (lsr & UART_LSR_THRE)
+				serial8250_tx_chars(up);
+		}
+	}
+
+	/*
+	 * Re-enable the transmitter if we disabled it.
+	 */
+	if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
+		up->acr &= ~UART_ACR_TXDIS;
+		serial_icr_write(up, UART_ACR, up->acr);
+	}
+}
+
+/**
+ * serial8250_em485_start_tx() - generic ->rs485_start_tx() callback
+ * @up: uart 8250 port
+ *
+ * Generic callback usable by 8250 uart drivers to start rs485 transmission.
+ * Assumes that setting the RTS bit in the MCR register means RTS is high.
+ * (Some chips use inverse semantics.)  Further assumes that reception is
+ * stoppable by disabling the UART_IER_RDI interrupt.  (Some chips set the
+ * UART_LSR_DR bit even when UART_IER_RDI is disabled, foiling this approach.)
+ */
+void serial8250_em485_start_tx(struct uart_8250_port *up)
+{
+	unsigned char mcr = serial8250_in_MCR(up);
+
+	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
+		serial8250_stop_rx(&up->port);
+
+	if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND)
+		mcr |= UART_MCR_RTS;
+	else
+		mcr &= ~UART_MCR_RTS;
+	serial8250_out_MCR(up, mcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_start_tx);
+
+/* Returns false, if start_tx_timer was setup to defer TX start */
+static bool start_tx_rs485(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct uart_8250_em485 *em485 = up->em485;
+
+	/*
+	 * While serial8250_em485_handle_stop_tx() is a noop if
+	 * em485->active_timer != &em485->stop_tx_timer, it might happen that
+	 * the timer is still armed and triggers only after the current bunch of
+	 * chars is send and em485->active_timer == &em485->stop_tx_timer again.
+	 * So cancel the timer. There is still a theoretical race condition if
+	 * the timer is already running and only comes around to check for
+	 * em485->active_timer when &em485->stop_tx_timer is armed again.
+	 */
+	if (em485->active_timer == &em485->stop_tx_timer)
+		hrtimer_try_to_cancel(&em485->stop_tx_timer);
+
+	em485->active_timer = NULL;
+
+	if (em485->tx_stopped) {
+		em485->tx_stopped = false;
+
+		up->rs485_start_tx(up);
+
+		if (up->port.rs485.delay_rts_before_send > 0) {
+			em485->active_timer = &em485->start_tx_timer;
+			start_hrtimer_ms(&em485->start_tx_timer,
+					 up->port.rs485.delay_rts_before_send);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t)
+{
+	struct uart_8250_em485 *em485 = container_of(t, struct uart_8250_em485,
+			start_tx_timer);
+	struct uart_8250_port *p = em485->port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&p->port.lock, flags);
+	if (em485->active_timer == &em485->start_tx_timer) {
+		__start_tx(&p->port);
+		em485->active_timer = NULL;
+	}
+	spin_unlock_irqrestore(&p->port.lock, flags);
+
+	return HRTIMER_NORESTART;
+}
+
+static void serial8250_start_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct uart_8250_em485 *em485 = up->em485;
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&port->lock);
+
+	if (!port->x_char && uart_circ_empty(&port->state->xmit))
+		return;
+
+	serial8250_rpm_get_tx(up);
+
+	if (em485) {
+		if ((em485->active_timer == &em485->start_tx_timer) ||
+		    !start_tx_rs485(port))
+			return;
+	}
+	__start_tx(port);
+}
+
+static void serial8250_throttle(struct uart_port *port)
+{
+	port->throttle(port);
+}
+
+static void serial8250_unthrottle(struct uart_port *port)
+{
+	port->unthrottle(port);
+}
+
+static void serial8250_disable_ms(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&port->lock);
+
+	/* no MSR capabilities */
+	if (up->bugs & UART_BUG_NOMSR)
+		return;
+
+	mctrl_gpio_disable_ms(up->gpios);
+
+	up->ier &= ~UART_IER_MSI;
+	serial_port_out(port, UART_IER, up->ier);
+}
+
+static void serial8250_enable_ms(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&port->lock);
+
+	/* no MSR capabilities */
+	if (up->bugs & UART_BUG_NOMSR)
+		return;
+
+	mctrl_gpio_enable_ms(up->gpios);
+
+	up->ier |= UART_IER_MSI;
+
+	serial8250_rpm_get(up);
+	serial_port_out(port, UART_IER, up->ier);
+	serial8250_rpm_put(up);
+}
+
+void serial8250_read_char(struct uart_8250_port *up, u16 lsr)
+{
+	struct uart_port *port = &up->port;
+	u8 ch, flag = TTY_NORMAL;
+
+	if (likely(lsr & UART_LSR_DR))
+		ch = serial_in(up, UART_RX);
+	else
+		/*
+		 * Intel 82571 has a Serial Over Lan device that will
+		 * set UART_LSR_BI without setting UART_LSR_DR when
+		 * it receives a break. To avoid reading from the
+		 * receive buffer without UART_LSR_DR bit set, we
+		 * just force the read character to be 0
+		 */
+		ch = 0;
+
+	port->icount.rx++;
+
+	lsr |= up->lsr_saved_flags;
+	up->lsr_saved_flags = 0;
+
+	if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
+		if (lsr & UART_LSR_BI) {
+			lsr &= ~(UART_LSR_FE | UART_LSR_PE);
+			port->icount.brk++;
+			/*
+			 * We do the SysRQ and SAK checking
+			 * here because otherwise the break
+			 * may get masked by ignore_status_mask
+			 * or read_status_mask.
+			 */
+			if (uart_handle_break(port))
+				return;
+		} else if (lsr & UART_LSR_PE)
+			port->icount.parity++;
+		else if (lsr & UART_LSR_FE)
+			port->icount.frame++;
+		if (lsr & UART_LSR_OE)
+			port->icount.overrun++;
+
+		/*
+		 * Mask off conditions which should be ignored.
+		 */
+		lsr &= port->read_status_mask;
+
+		if (lsr & UART_LSR_BI) {
+			dev_dbg(port->dev, "handling break\n");
+			flag = TTY_BREAK;
+		} else if (lsr & UART_LSR_PE)
+			flag = TTY_PARITY;
+		else if (lsr & UART_LSR_FE)
+			flag = TTY_FRAME;
+	}
+	if (uart_prepare_sysrq_char(port, ch))
+		return;
+
+	uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
+}
+EXPORT_SYMBOL_GPL(serial8250_read_char);
+
+/*
+ * serial8250_rx_chars - Read characters. The first LSR value must be passed in.
+ *
+ * Returns LSR bits. The caller should rely only on non-Rx related LSR bits
+ * (such as THRE) because the LSR value might come from an already consumed
+ * character.
+ */
+u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr)
+{
+	struct uart_port *port = &up->port;
+	int max_count = 256;
+
+	do {
+		serial8250_read_char(up, lsr);
+		if (--max_count == 0)
+			break;
+		lsr = serial_in(up, UART_LSR);
+	} while (lsr & (UART_LSR_DR | UART_LSR_BI));
+
+	tty_flip_buffer_push(&port->state->port);
+	return lsr;
+}
+EXPORT_SYMBOL_GPL(serial8250_rx_chars);
+
+void serial8250_tx_chars(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	int count;
+
+	if (port->x_char) {
+		uart_xchar_out(port, UART_TX);
+		return;
+	}
+	if (uart_tx_stopped(port)) {
+		serial8250_stop_tx(port);
+		return;
+	}
+	if (uart_circ_empty(xmit)) {
+		__stop_tx(up);
+		return;
+	}
+
+	count = up->tx_loadsz;
+	do {
+		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		if (up->bugs & UART_BUG_TXRACE) {
+			/*
+			 * The Aspeed BMC virtual UARTs have a bug where data
+			 * may get stuck in the BMC's Tx FIFO from bursts of
+			 * writes on the APB interface.
+			 *
+			 * Delay back-to-back writes by a read cycle to avoid
+			 * stalling the VUART. Read a register that won't have
+			 * side-effects and discard the result.
+			 */
+			serial_in(up, UART_SCR);
+		}
+		uart_xmit_advance(port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+		if ((up->capabilities & UART_CAP_HFIFO) &&
+		    !uart_lsr_tx_empty(serial_in(up, UART_LSR)))
+			break;
+		/* The BCM2835 MINI UART THRE bit is really a not-full bit. */
+		if ((up->capabilities & UART_CAP_MINI) &&
+		    !(serial_in(up, UART_LSR) & UART_LSR_THRE))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	/*
+	 * With RPM enabled, we have to wait until the FIFO is empty before the
+	 * HW can go idle. So we get here once again with empty FIFO and disable
+	 * the interrupt and RPM in __stop_tx()
+	 */
+	if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
+		__stop_tx(up);
+}
+EXPORT_SYMBOL_GPL(serial8250_tx_chars);
+
+/* Caller holds uart port lock */
+unsigned int serial8250_modem_status(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	unsigned int status = serial_in(up, UART_MSR);
+
+	status |= up->msr_saved_flags;
+	up->msr_saved_flags = 0;
+	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
+	    port->state != NULL) {
+		if (status & UART_MSR_TERI)
+			port->icount.rng++;
+		if (status & UART_MSR_DDSR)
+			port->icount.dsr++;
+		if (status & UART_MSR_DDCD)
+			uart_handle_dcd_change(port, status & UART_MSR_DCD);
+		if (status & UART_MSR_DCTS)
+			uart_handle_cts_change(port, status & UART_MSR_CTS);
+
+		wake_up_interruptible(&port->state->port.delta_msr_wait);
+	}
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(serial8250_modem_status);
+
+static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
+{
+	switch (iir & 0x3f) {
+	case UART_IIR_THRI:
+		/*
+		 * Postpone DMA or not decision to IIR_RDI or IIR_RX_TIMEOUT
+		 * because it's impossible to do an informed decision about
+		 * that with IIR_THRI.
+		 *
+		 * This also fixes one known DMA Rx corruption issue where
+		 * DR is asserted but DMA Rx only gets a corrupted zero byte
+		 * (too early DR?).
+		 */
+		return false;
+	case UART_IIR_RDI:
+		if (!up->dma->rx_running)
+			break;
+		fallthrough;
+	case UART_IIR_RLSI:
+	case UART_IIR_RX_TIMEOUT:
+		serial8250_rx_dma_flush(up);
+		return true;
+	}
+	return up->dma->rx_dma(up);
+}
+
+/*
+ * This handles the interrupt from one port.
+ */
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct tty_port *tport = &port->state->port;
+	bool skip_rx = false;
+	unsigned long flags;
+	u16 status;
+
+	if (iir & UART_IIR_NO_INT)
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	status = serial_lsr_in(up);
+
+	/*
+	 * If port is stopped and there are no error conditions in the
+	 * FIFO, then don't drain the FIFO, as this may lead to TTY buffer
+	 * overflow. Not servicing, RX FIFO would trigger auto HW flow
+	 * control when FIFO occupancy reaches preset threshold, thus
+	 * halting RX. This only works when auto HW flow control is
+	 * available.
+	 */
+	if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)) &&
+	    (port->status & (UPSTAT_AUTOCTS | UPSTAT_AUTORTS)) &&
+	    !(port->read_status_mask & UART_LSR_DR))
+		skip_rx = true;
+
+	if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) {
+		struct irq_data *d;
+
+		d = irq_get_irq_data(port->irq);
+		if (d && irqd_is_wakeup_set(d))
+			pm_wakeup_event(tport->tty->dev, 0);
+		if (!up->dma || handle_rx_dma(up, iir))
+			status = serial8250_rx_chars(up, status);
+	}
+	serial8250_modem_status(up);
+	if ((status & UART_LSR_THRE) && (up->ier & UART_IER_THRI)) {
+		if (!up->dma || up->dma->tx_err)
+			serial8250_tx_chars(up);
+		else if (!up->dma->tx_running)
+			__stop_tx(up);
+	}
+
+	uart_unlock_and_check_sysrq_irqrestore(port, flags);
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(serial8250_handle_irq);
+
+static int serial8250_default_handle_irq(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int iir;
+	int ret;
+
+	serial8250_rpm_get(up);
+
+	iir = serial_port_in(port, UART_IIR);
+	ret = serial8250_handle_irq(port, iir);
+
+	serial8250_rpm_put(up);
+	return ret;
+}
+
+/*
+ * Newer 16550 compatible parts such as the SC16C650 & Altera 16550 Soft IP
+ * have a programmable TX threshold that triggers the THRE interrupt in
+ * the IIR register. In this case, the THRE interrupt indicates the FIFO
+ * has space available. Load it up with tx_loadsz bytes.
+ */
+static int serial8250_tx_threshold_handle_irq(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned int iir = serial_port_in(port, UART_IIR);
+
+	/* TX Threshold IRQ triggered so load up FIFO */
+	if ((iir & UART_IIR_ID) == UART_IIR_THRI) {
+		struct uart_8250_port *up = up_to_u8250p(port);
+
+		spin_lock_irqsave(&port->lock, flags);
+		serial8250_tx_chars(up);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+
+	iir = serial_port_in(port, UART_IIR);
+	return serial8250_handle_irq(port, iir);
+}
+
+static unsigned int serial8250_tx_empty(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int result = 0;
+	unsigned long flags;
+
+	serial8250_rpm_get(up);
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (!serial8250_tx_dma_running(up) && uart_lsr_tx_empty(serial_lsr_in(up)))
+		result = TIOCSER_TEMT;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	serial8250_rpm_put(up);
+
+	return result;
+}
+
+unsigned int serial8250_do_get_mctrl(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int status;
+	unsigned int val;
+
+	serial8250_rpm_get(up);
+	status = serial8250_modem_status(up);
+	serial8250_rpm_put(up);
+
+	val = serial8250_MSR_to_TIOCM(status);
+	if (up->gpios)
+		return mctrl_gpio_get(up->gpios, &val);
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);
+
+static unsigned int serial8250_get_mctrl(struct uart_port *port)
+{
+	if (port->get_mctrl)
+		return port->get_mctrl(port);
+	return serial8250_do_get_mctrl(port);
+}
+
+void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned char mcr;
+
+	mcr = serial8250_TIOCM_to_MCR(mctrl);
+
+	mcr |= up->mcr;
+
+	serial8250_out_MCR(up, mcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl);
+
+static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		return;
+
+	if (port->set_mctrl)
+		port->set_mctrl(port, mctrl);
+	else
+		serial8250_do_set_mctrl(port, mctrl);
+}
+
+static void serial8250_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	serial8250_rpm_get(up);
+	spin_lock_irqsave(&port->lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_port_out(port, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+}
+
+static void wait_for_lsr(struct uart_8250_port *up, int bits)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	for (;;) {
+		status = serial_lsr_in(up);
+
+		if ((status & bits) == bits)
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+		touch_nmi_watchdog();
+	}
+}
+
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_8250_port *up, int bits)
+{
+	unsigned int tmout;
+
+	wait_for_lsr(up, bits);
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		for (tmout = 1000000; tmout; tmout--) {
+			unsigned int msr = serial_in(up, UART_MSR);
+			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
+			if (msr & UART_MSR_CTS)
+				break;
+			udelay(1);
+			touch_nmi_watchdog();
+		}
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial8250_get_poll_char(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	int status;
+	u16 lsr;
+
+	serial8250_rpm_get(up);
+
+	lsr = serial_port_in(port, UART_LSR);
+
+	if (!(lsr & UART_LSR_DR)) {
+		status = NO_POLL_CHAR;
+		goto out;
+	}
+
+	status = serial_port_in(port, UART_RX);
+out:
+	serial8250_rpm_put(up);
+	return status;
+}
+
+
+static void serial8250_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/*
+	 * Normally the port is locked to synchronize UART_IER access
+	 * against the console. However, this function is only used by
+	 * KDB/KGDB, where it may not be possible to acquire the port
+	 * lock because all other CPUs are quiesced. The quiescence
+	 * should allow safe lockless usage here.
+	 */
+
+	serial8250_rpm_get(up);
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_port_in(port, UART_IER);
+	serial8250_clear_IER(up);
+
+	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
+	/*
+	 *	Send the character out.
+	 */
+	serial_port_out(port, UART_TX, c);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
+	serial_port_out(port, UART_IER, ier);
+	serial8250_rpm_put(up);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+int serial8250_do_startup(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+	unsigned char iir;
+	int retval;
+	u16 lsr;
+
+	if (!port->fifosize)
+		port->fifosize = uart_config[port->type].fifo_size;
+	if (!up->tx_loadsz)
+		up->tx_loadsz = uart_config[port->type].tx_loadsz;
+	if (!up->capabilities)
+		up->capabilities = uart_config[port->type].flags;
+	up->mcr = 0;
+
+	if (port->iotype != up->cur_iotype)
+		set_io_from_upio(port);
+
+	serial8250_rpm_get(up);
+	if (port->type == PORT_16C950) {
+		/*
+		 * Wake up and initialize UART
+		 *
+		 * Synchronize UART_IER access against the console.
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+		up->acr = 0;
+		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_port_out(port, UART_EFR, UART_EFR_ECB);
+		serial_port_out(port, UART_IER, 0);
+		serial_port_out(port, UART_LCR, 0);
+		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
+		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_port_out(port, UART_EFR, UART_EFR_ECB);
+		serial_port_out(port, UART_LCR, 0);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+
+	if (port->type == PORT_DA830) {
+		/*
+		 * Reset the port
+		 *
+		 * Synchronize UART_IER access against the console.
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+		serial_port_out(port, UART_IER, 0);
+		serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
+		spin_unlock_irqrestore(&port->lock, flags);
+		mdelay(10);
+
+		/* Enable Tx, Rx and free run mode */
+		serial_port_out(port, UART_DA830_PWREMU_MGMT,
+				UART_DA830_PWREMU_MGMT_UTRST |
+				UART_DA830_PWREMU_MGMT_URRST |
+				UART_DA830_PWREMU_MGMT_FREE);
+	}
+
+	if (port->type == PORT_NPCM) {
+		/*
+		 * Nuvoton calls the scratch register 'UART_TOR' (timeout
+		 * register). Enable it, and set TIOC (timeout interrupt
+		 * comparator) to be 0x20 for correct operation.
+		 */
+		serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20);
+	}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * If this is an RSA port, see if we can kick it up to the
+	 * higher speed clock.
+	 */
+	enable_rsa(up);
+#endif
+
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	serial8250_clear_fifos(up);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	serial_port_in(port, UART_LSR);
+	serial_port_in(port, UART_RX);
+	serial_port_in(port, UART_IIR);
+	serial_port_in(port, UART_MSR);
+
+	/*
+	 * At this point, there's no way the LSR could still be 0xff;
+	 * if it is, then bail out, because there's likely no UART
+	 * here.
+	 */
+	if (!(port->flags & UPF_BUGGY_UART) &&
+	    (serial_port_in(port, UART_LSR) == 0xff)) {
+		dev_info_ratelimited(port->dev, "LSR safety check engaged!\n");
+		retval = -ENODEV;
+		goto out;
+	}
+
+	/*
+	 * For a XR16C850, we need to set the trigger levels
+	 */
+	if (port->type == PORT_16850) {
+		unsigned char fctr;
+
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+		fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
+		serial_port_out(port, UART_FCTR,
+				fctr | UART_FCTR_TRGD | UART_FCTR_RX);
+		serial_port_out(port, UART_TRG, UART_TRG_96);
+		serial_port_out(port, UART_FCTR,
+				fctr | UART_FCTR_TRGD | UART_FCTR_TX);
+		serial_port_out(port, UART_TRG, UART_TRG_96);
+
+		serial_port_out(port, UART_LCR, 0);
+	}
+
+	/*
+	 * For the Altera 16550 variants, set TX threshold trigger level.
+	 */
+	if (((port->type == PORT_ALTR_16550_F32) ||
+	     (port->type == PORT_ALTR_16550_F64) ||
+	     (port->type == PORT_ALTR_16550_F128)) && (port->fifosize > 1)) {
+		/* Bounds checking of TX threshold (valid 0 to fifosize-2) */
+		if ((up->tx_loadsz < 2) || (up->tx_loadsz > port->fifosize)) {
+			dev_err(port->dev, "TX FIFO Threshold errors, skipping\n");
+		} else {
+			serial_port_out(port, UART_ALTR_AFR,
+					UART_ALTR_EN_TXFIFO_LW);
+			serial_port_out(port, UART_ALTR_TX_LOW,
+					port->fifosize - up->tx_loadsz);
+			port->handle_irq = serial8250_tx_threshold_handle_irq;
+		}
+	}
+
+	/* Check if we need to have shared IRQs */
+	if (port->irq && (up->port.flags & UPF_SHARE_IRQ))
+		up->port.irqflags |= IRQF_SHARED;
+
+	retval = up->ops->setup_irq(up);
+	if (retval)
+		goto out;
+
+	if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) {
+		unsigned char iir1;
+
+		if (port->irqflags & IRQF_SHARED)
+			disable_irq_nosync(port->irq);
+
+		/*
+		 * Test for UARTs that do not reassert THRE when the
+		 * transmitter is idle and the interrupt has already
+		 * been cleared.  Real 16550s should always reassert
+		 * this interrupt whenever the transmitter is idle and
+		 * the interrupt is enabled.  Delays are necessary to
+		 * allow register changes to become visible.
+		 *
+		 * Synchronize UART_IER access against the console.
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+
+		wait_for_xmitr(up, UART_LSR_THRE);
+		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
+		udelay(1); /* allow THRE to set */
+		iir1 = serial_port_in(port, UART_IIR);
+		serial_port_out(port, UART_IER, 0);
+		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
+		udelay(1); /* allow a working UART time to re-assert THRE */
+		iir = serial_port_in(port, UART_IIR);
+		serial_port_out(port, UART_IER, 0);
+
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		if (port->irqflags & IRQF_SHARED)
+			enable_irq(port->irq);
+
+		/*
+		 * If the interrupt is not reasserted, or we otherwise
+		 * don't trust the iir, setup a timer to kick the UART
+		 * on a regular basis.
+		 */
+		if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||
+		    up->port.flags & UPF_BUG_THRE) {
+			up->bugs |= UART_BUG_THRE;
+		}
+	}
+
+	up->ops->setup_timer(up);
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (up->port.flags & UPF_FOURPORT) {
+		if (!up->port.irq)
+			up->port.mctrl |= TIOCM_OUT1;
+	} else
+		/*
+		 * Most PC uarts need OUT2 raised to enable interrupts.
+		 */
+		if (port->irq)
+			up->port.mctrl |= TIOCM_OUT2;
+
+	serial8250_set_mctrl(port, port->mctrl);
+
+	/*
+	 * Serial over Lan (SoL) hack:
+	 * Intel 8257x Gigabit ethernet chips have a 16550 emulation, to be
+	 * used for Serial Over Lan.  Those chips take a longer time than a
+	 * normal serial device to signalize that a transmission data was
+	 * queued. Due to that, the above test generally fails. One solution
+	 * would be to delay the reading of iir. However, this is not
+	 * reliable, since the timeout is variable. So, let's just don't
+	 * test if we receive TX irq.  This way, we'll never enable
+	 * UART_BUG_TXEN.
+	 */
+	if (up->port.quirks & UPQ_NO_TXEN_TEST)
+		goto dont_test_tx_en;
+
+	/*
+	 * Do a quick test to see if we receive an interrupt when we enable
+	 * the TX irq.
+	 */
+	serial_port_out(port, UART_IER, UART_IER_THRI);
+	lsr = serial_port_in(port, UART_LSR);
+	iir = serial_port_in(port, UART_IIR);
+	serial_port_out(port, UART_IER, 0);
+
+	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
+		if (!(up->bugs & UART_BUG_TXEN)) {
+			up->bugs |= UART_BUG_TXEN;
+			dev_dbg(port->dev, "enabling bad tx status workarounds\n");
+		}
+	} else {
+		up->bugs &= ~UART_BUG_TXEN;
+	}
+
+dont_test_tx_en:
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/*
+	 * Clear the interrupt registers again for luck, and clear the
+	 * saved flags to avoid getting false values from polling
+	 * routines or the previous session.
+	 */
+	serial_port_in(port, UART_LSR);
+	serial_port_in(port, UART_RX);
+	serial_port_in(port, UART_IIR);
+	serial_port_in(port, UART_MSR);
+	up->lsr_saved_flags = 0;
+	up->msr_saved_flags = 0;
+
+	/*
+	 * Request DMA channels for both RX and TX.
+	 */
+	if (up->dma) {
+		const char *msg = NULL;
+
+		if (uart_console(port))
+			msg = "forbid DMA for kernel console";
+		else if (serial8250_request_dma(up))
+			msg = "failed to request DMA";
+		if (msg) {
+			dev_warn_ratelimited(port->dev, "%s\n", msg);
+			up->dma = NULL;
+		}
+	}
+
+	/*
+	 * Set the IER shadow for rx interrupts but defer actual interrupt
+	 * enable until after the FIFOs are enabled; otherwise, an already-
+	 * active sender can swamp the interrupt handler with "too much work".
+	 */
+	up->ier = UART_IER_RLSI | UART_IER_RDI;
+
+	if (port->flags & UPF_FOURPORT) {
+		unsigned int icp;
+		/*
+		 * Enable interrupts on the AST Fourport board
+		 */
+		icp = (port->iobase & 0xfe0) | 0x01f;
+		outb_p(0x80, icp);
+		inb_p(icp);
+	}
+	retval = 0;
+out:
+	serial8250_rpm_put(up);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(serial8250_do_startup);
+
+static int serial8250_startup(struct uart_port *port)
+{
+	if (port->startup)
+		return port->startup(port);
+	return serial8250_do_startup(port);
+}
+
+void serial8250_do_shutdown(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	serial8250_rpm_get(up);
+	/*
+	 * Disable interrupts from this port
+	 *
+	 * Synchronize UART_IER access against the console.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+	up->ier = 0;
+	serial_port_out(port, UART_IER, 0);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	synchronize_irq(port->irq);
+
+	if (up->dma)
+		serial8250_release_dma(up);
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (port->flags & UPF_FOURPORT) {
+		/* reset interrupts on the AST Fourport board */
+		inb((port->iobase & 0xfe0) | 0x1f);
+		port->mctrl |= TIOCM_OUT1;
+	} else
+		port->mctrl &= ~TIOCM_OUT2;
+
+	serial8250_set_mctrl(port, port->mctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	serial_port_out(port, UART_LCR,
+			serial_port_in(port, UART_LCR) & ~UART_LCR_SBC);
+	serial8250_clear_fifos(up);
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * Reset the RSA board back to 115kbps compat mode.
+	 */
+	disable_rsa(up);
+#endif
+
+	/*
+	 * Read data port to reset things, and then unlink from
+	 * the IRQ chain.
+	 */
+	serial_port_in(port, UART_RX);
+	serial8250_rpm_put(up);
+
+	up->ops->release_irq(up);
+}
+EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
+
+static void serial8250_shutdown(struct uart_port *port)
+{
+	if (port->shutdown)
+		port->shutdown(port);
+	else
+		serial8250_do_shutdown(port);
+}
+
+/* Nuvoton NPCM UARTs have a custom divisor calculation */
+static unsigned int npcm_get_divisor(struct uart_8250_port *up,
+		unsigned int baud)
+{
+	struct uart_port *port = &up->port;
+
+	return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2;
+}
+
+static unsigned int serial8250_do_get_divisor(struct uart_port *port,
+					      unsigned int baud,
+					      unsigned int *frac)
+{
+	upf_t magic_multiplier = port->flags & UPF_MAGIC_MULTIPLIER;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int quot;
+
+	/*
+	 * Handle magic divisors for baud rates above baud_base on SMSC
+	 * Super I/O chips.  We clamp custom rates from clk/6 and clk/12
+	 * up to clk/4 (0x8001) and clk/8 (0x8002) respectively.  These
+	 * magic divisors actually reprogram the baud rate generator's
+	 * reference clock derived from chips's 14.318MHz clock input.
+	 *
+	 * Documentation claims that with these magic divisors the base
+	 * frequencies of 7.3728MHz and 3.6864MHz are used respectively
+	 * for the extra baud rates of 460800bps and 230400bps rather
+	 * than the usual base frequency of 1.8462MHz.  However empirical
+	 * evidence contradicts that.
+	 *
+	 * Instead bit 7 of the DLM register (bit 15 of the divisor) is
+	 * effectively used as a clock prescaler selection bit for the
+	 * base frequency of 7.3728MHz, always used.  If set to 0, then
+	 * the base frequency is divided by 4 for use by the Baud Rate
+	 * Generator, for the usual arrangement where the value of 1 of
+	 * the divisor produces the baud rate of 115200bps.  Conversely,
+	 * if set to 1 and high-speed operation has been enabled with the
+	 * Serial Port Mode Register in the Device Configuration Space,
+	 * then the base frequency is supplied directly to the Baud Rate
+	 * Generator, so for the divisor values of 0x8001, 0x8002, 0x8003,
+	 * 0x8004, etc. the respective baud rates produced are 460800bps,
+	 * 230400bps, 153600bps, 115200bps, etc.
+	 *
+	 * In all cases only low 15 bits of the divisor are used to divide
+	 * the baud base and therefore 32767 is the maximum divisor value
+	 * possible, even though documentation says that the programmable
+	 * Baud Rate Generator is capable of dividing the internal PLL
+	 * clock by any divisor from 1 to 65535.
+	 */
+	if (magic_multiplier && baud >= port->uartclk / 6)
+		quot = 0x8001;
+	else if (magic_multiplier && baud >= port->uartclk / 12)
+		quot = 0x8002;
+	else if (up->port.type == PORT_NPCM)
+		quot = npcm_get_divisor(up, baud);
+	else
+		quot = uart_get_divisor(port, baud);
+
+	/*
+	 * Oxford Semi 952 rev B workaround
+	 */
+	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
+		quot++;
+
+	return quot;
+}
+
+static unsigned int serial8250_get_divisor(struct uart_port *port,
+					   unsigned int baud,
+					   unsigned int *frac)
+{
+	if (port->get_divisor)
+		return port->get_divisor(port, baud, frac);
+
+	return serial8250_do_get_divisor(port, baud, frac);
+}
+
+static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
+					    tcflag_t c_cflag)
+{
+	unsigned char cval;
+
+	cval = UART_LCR_WLEN(tty_get_char_size(c_cflag));
+
+	if (c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (c_cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	if (c_cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+
+	return cval;
+}
+
+void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
+			       unsigned int quot, unsigned int quot_frac)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
+	if (is_omap1510_8250(up)) {
+		if (baud == 115200) {
+			quot = 1;
+			serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1);
+		} else
+			serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0);
+	}
+
+	/*
+	 * For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2,
+	 * otherwise just set DLAB
+	 */
+	if (up->capabilities & UART_NATSEMI)
+		serial_port_out(port, UART_LCR, 0xe0);
+	else
+		serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
+
+	serial_dl_write(up, quot);
+}
+EXPORT_SYMBOL_GPL(serial8250_do_set_divisor);
+
+static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
+				   unsigned int quot, unsigned int quot_frac)
+{
+	if (port->set_divisor)
+		port->set_divisor(port, baud, quot, quot_frac);
+	else
+		serial8250_do_set_divisor(port, baud, quot, quot_frac);
+}
+
+static unsigned int serial8250_get_baud_rate(struct uart_port *port,
+					     struct ktermios *termios,
+					     const struct ktermios *old)
+{
+	unsigned int tolerance = port->uartclk / 100;
+	unsigned int min;
+	unsigned int max;
+
+	/*
+	 * Handle magic divisors for baud rates above baud_base on SMSC
+	 * Super I/O chips.  Enable custom rates of clk/4 and clk/8, but
+	 * disable divisor values beyond 32767, which are unavailable.
+	 */
+	if (port->flags & UPF_MAGIC_MULTIPLIER) {
+		min = port->uartclk / 16 / UART_DIV_MAX >> 1;
+		max = (port->uartclk + tolerance) / 4;
+	} else {
+		min = port->uartclk / 16 / UART_DIV_MAX;
+		max = (port->uartclk + tolerance) / 16;
+	}
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 * Allow 1% tolerance at the upper limit so uart clks marginally
+	 * slower than nominal still match standard baud rates without
+	 * causing transmission errors.
+	 */
+	return uart_get_baud_rate(port, termios, old, min, max);
+}
+
+/*
+ * Note in order to avoid the tty port mutex deadlock don't use the next method
+ * within the uart port callbacks. Primarily it's supposed to be utilized to
+ * handle a sudden reference clock rate change.
+ */
+void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct tty_port *tport = &port->state->port;
+	unsigned int baud, quot, frac = 0;
+	struct ktermios *termios;
+	struct tty_struct *tty;
+	unsigned long flags;
+
+	tty = tty_port_tty_get(tport);
+	if (!tty) {
+		mutex_lock(&tport->mutex);
+		port->uartclk = uartclk;
+		mutex_unlock(&tport->mutex);
+		return;
+	}
+
+	down_write(&tty->termios_rwsem);
+	mutex_lock(&tport->mutex);
+
+	if (port->uartclk == uartclk)
+		goto out_unlock;
+
+	port->uartclk = uartclk;
+
+	if (!tty_port_initialized(tport))
+		goto out_unlock;
+
+	termios = &tty->termios;
+
+	baud = serial8250_get_baud_rate(port, termios, NULL);
+	quot = serial8250_get_divisor(port, baud, &frac);
+
+	serial8250_rpm_get(up);
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	serial8250_set_divisor(port, baud, quot, frac);
+	serial_port_out(port, UART_LCR, up->lcr);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+
+out_unlock:
+	mutex_unlock(&tport->mutex);
+	up_write(&tty->termios_rwsem);
+	tty_kref_put(tty);
+}
+EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
+
+void
+serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
+		          const struct ktermios *old)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned char cval;
+	unsigned long flags;
+	unsigned int baud, quot, frac = 0;
+
+	if (up->capabilities & UART_CAP_MINI) {
+		termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CMSPAR);
+		if ((termios->c_cflag & CSIZE) == CS5 ||
+		    (termios->c_cflag & CSIZE) == CS6)
+			termios->c_cflag = (termios->c_cflag & ~CSIZE) | CS7;
+	}
+	cval = serial8250_compute_lcr(up, termios->c_cflag);
+
+	baud = serial8250_get_baud_rate(port, termios, old);
+	quot = serial8250_get_divisor(port, baud, &frac);
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 *
+	 * Synchronize UART_IER access against the console.
+	 */
+	serial8250_rpm_get(up);
+	spin_lock_irqsave(&port->lock, flags);
+
+	up->lcr = cval;					/* Save computed LCR */
+
+	if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) {
+		if (baud < 2400 && !up->dma) {
+			up->fcr &= ~UART_FCR_TRIGGER_MASK;
+			up->fcr |= UART_FCR_TRIGGER_1;
+		}
+	}
+
+	/*
+	 * MCR-based auto flow control.  When AFE is enabled, RTS will be
+	 * deasserted when the receive FIFO contains more characters than
+	 * the trigger, or the MCR RTS bit is cleared.
+	 */
+	if (up->capabilities & UART_CAP_AFE) {
+		up->mcr &= ~UART_MCR_AFE;
+		if (termios->c_cflag & CRTSCTS)
+			up->mcr |= UART_MCR_AFE;
+	}
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * CTS flow control flag and modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (!(up->bugs & UART_BUG_NOMSR) &&
+			UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+	if (up->capabilities & UART_CAP_UUE)
+		up->ier |= UART_IER_UUE;
+	if (up->capabilities & UART_CAP_RTOIE)
+		up->ier |= UART_IER_RTOIE;
+
+	serial_port_out(port, UART_IER, up->ier);
+
+	if (up->capabilities & UART_CAP_EFR) {
+		unsigned char efr = 0;
+		/*
+		 * TI16C752/Startech hardware flow control.  FIXME:
+		 * - TI16C752 requires control thresholds to be set.
+		 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
+		 */
+		if (termios->c_cflag & CRTSCTS)
+			efr |= UART_EFR_CTS;
+
+		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+		if (port->flags & UPF_EXAR_EFR)
+			serial_port_out(port, UART_XR_EFR, efr);
+		else
+			serial_port_out(port, UART_EFR, efr);
+	}
+
+	serial8250_set_divisor(port, baud, quot, frac);
+
+	/*
+	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
+	 * is written without DLAB set, this mode will be disabled.
+	 */
+	if (port->type == PORT_16750)
+		serial_port_out(port, UART_FCR, up->fcr);
+
+	serial_port_out(port, UART_LCR, up->lcr);	/* reset DLAB */
+	if (port->type != PORT_16750) {
+		/* emulated UARTs (Lucent Venus 167x) need two steps */
+		if (up->fcr & UART_FCR_ENABLE_FIFO)
+			serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_port_out(port, UART_FCR, up->fcr);	/* set fcr */
+	}
+	serial8250_set_mctrl(port, port->mctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+EXPORT_SYMBOL(serial8250_do_set_termios);
+
+static void
+serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
+		       const struct ktermios *old)
+{
+	if (port->set_termios)
+		port->set_termios(port, termios, old);
+	else
+		serial8250_do_set_termios(port, termios, old);
+}
+
+void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	if (termios->c_line == N_PPS) {
+		port->flags |= UPF_HARDPPS_CD;
+		spin_lock_irq(&port->lock);
+		serial8250_enable_ms(port);
+		spin_unlock_irq(&port->lock);
+	} else {
+		port->flags &= ~UPF_HARDPPS_CD;
+		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
+			spin_lock_irq(&port->lock);
+			serial8250_disable_ms(port);
+			spin_unlock_irq(&port->lock);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(serial8250_do_set_ldisc);
+
+static void
+serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	if (port->set_ldisc)
+		port->set_ldisc(port, termios);
+	else
+		serial8250_do_set_ldisc(port, termios);
+}
+
+void serial8250_do_pm(struct uart_port *port, unsigned int state,
+		      unsigned int oldstate)
+{
+	struct uart_8250_port *p = up_to_u8250p(port);
+
+	serial8250_set_sleep(p, state != 0);
+}
+EXPORT_SYMBOL(serial8250_do_pm);
+
+static void
+serial8250_pm(struct uart_port *port, unsigned int state,
+	      unsigned int oldstate)
+{
+	if (port->pm)
+		port->pm(port, state, oldstate);
+	else
+		serial8250_do_pm(port, state, oldstate);
+}
+
+static unsigned int serial8250_port_size(struct uart_8250_port *pt)
+{
+	if (pt->port.mapsize)
+		return pt->port.mapsize;
+	if (is_omap1_8250(pt))
+		return 0x16 << pt->port.regshift;
+
+	return 8 << pt->port.regshift;
+}
+
+/*
+ * Resource handling.
+ */
+static int serial8250_request_std_resource(struct uart_8250_port *up)
+{
+	unsigned int size = serial8250_port_size(up);
+	struct uart_port *port = &up->port;
+	int ret = 0;
+
+	switch (port->iotype) {
+	case UPIO_AU:
+	case UPIO_TSI:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_MEM16:
+	case UPIO_MEM:
+		if (!port->mapbase) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (!request_mem_region(port->mapbase, size, "serial")) {
+			ret = -EBUSY;
+			break;
+		}
+
+		if (port->flags & UPF_IOREMAP) {
+			port->membase = ioremap(port->mapbase, size);
+			if (!port->membase) {
+				release_mem_region(port->mapbase, size);
+				ret = -ENOMEM;
+			}
+		}
+		break;
+
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		if (!request_region(port->iobase, size, "serial"))
+			ret = -EBUSY;
+		break;
+	}
+	return ret;
+}
+
+static void serial8250_release_std_resource(struct uart_8250_port *up)
+{
+	unsigned int size = serial8250_port_size(up);
+	struct uart_port *port = &up->port;
+
+	switch (port->iotype) {
+	case UPIO_AU:
+	case UPIO_TSI:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_MEM16:
+	case UPIO_MEM:
+		if (!port->mapbase)
+			break;
+
+		if (port->flags & UPF_IOREMAP) {
+			iounmap(port->membase);
+			port->membase = NULL;
+		}
+
+		release_mem_region(port->mapbase, size);
+		break;
+
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		release_region(port->iobase, size);
+		break;
+	}
+}
+
+static void serial8250_release_port(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_release_std_resource(up);
+}
+
+static int serial8250_request_port(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	return serial8250_request_std_resource(up);
+}
+
+static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
+{
+	const struct serial8250_config *conf_type = &uart_config[up->port.type];
+	unsigned char bytes;
+
+	bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)];
+
+	return bytes ? bytes : -EOPNOTSUPP;
+}
+
+static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes)
+{
+	const struct serial8250_config *conf_type = &uart_config[up->port.type];
+	int i;
+
+	if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)])
+		return -EOPNOTSUPP;
+
+	for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) {
+		if (bytes < conf_type->rxtrig_bytes[i])
+			/* Use the nearest lower value */
+			return (--i) << UART_FCR_R_TRIG_SHIFT;
+	}
+
+	return UART_FCR_R_TRIG_11;
+}
+
+static int do_get_rxtrig(struct tty_port *port)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport = state->uart_port;
+	struct uart_8250_port *up = up_to_u8250p(uport);
+
+	if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
+		return -EINVAL;
+
+	return fcr_get_rxtrig_bytes(up);
+}
+
+static int do_serial8250_get_rxtrig(struct tty_port *port)
+{
+	int rxtrig_bytes;
+
+	mutex_lock(&port->mutex);
+	rxtrig_bytes = do_get_rxtrig(port);
+	mutex_unlock(&port->mutex);
+
+	return rxtrig_bytes;
+}
+
+static ssize_t rx_trig_bytes_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	int rxtrig_bytes;
+
+	rxtrig_bytes = do_serial8250_get_rxtrig(port);
+	if (rxtrig_bytes < 0)
+		return rxtrig_bytes;
+
+	return sysfs_emit(buf, "%d\n", rxtrig_bytes);
+}
+
+static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport = state->uart_port;
+	struct uart_8250_port *up = up_to_u8250p(uport);
+	int rxtrig;
+
+	if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
+		return -EINVAL;
+
+	rxtrig = bytes_to_fcr_rxtrig(up, bytes);
+	if (rxtrig < 0)
+		return rxtrig;
+
+	serial8250_clear_fifos(up);
+	up->fcr &= ~UART_FCR_TRIGGER_MASK;
+	up->fcr |= (unsigned char)rxtrig;
+	serial_out(up, UART_FCR, up->fcr);
+	return 0;
+}
+
+static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes)
+{
+	int ret;
+
+	mutex_lock(&port->mutex);
+	ret = do_set_rxtrig(port, bytes);
+	mutex_unlock(&port->mutex);
+
+	return ret;
+}
+
+static ssize_t rx_trig_bytes_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	unsigned char bytes;
+	int ret;
+
+	if (!count)
+		return -EINVAL;
+
+	ret = kstrtou8(buf, 10, &bytes);
+	if (ret < 0)
+		return ret;
+
+	ret = do_serial8250_set_rxtrig(port, bytes);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(rx_trig_bytes);
+
+static struct attribute *serial8250_dev_attrs[] = {
+	&dev_attr_rx_trig_bytes.attr,
+	NULL
+};
+
+static struct attribute_group serial8250_dev_attr_group = {
+	.attrs = serial8250_dev_attrs,
+};
+
+static void register_dev_spec_attr_grp(struct uart_8250_port *up)
+{
+	const struct serial8250_config *conf_type = &uart_config[up->port.type];
+
+	if (conf_type->rxtrig_bytes[0])
+		up->port.attr_group = &serial8250_dev_attr_group;
+}
+
+static void serial8250_config_port(struct uart_port *port, int flags)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	int ret;
+
+	/*
+	 * Find the region that we can probe for.  This in turn
+	 * tells us whether we can probe for the type of port.
+	 */
+	ret = serial8250_request_std_resource(up);
+	if (ret < 0)
+		return;
+
+	if (port->iotype != up->cur_iotype)
+		set_io_from_upio(port);
+
+	if (flags & UART_CONFIG_TYPE)
+		autoconfig(up);
+
+	/* HW bugs may trigger IRQ while IIR == NO_INT */
+	if (port->type == PORT_TEGRA)
+		up->bugs |= UART_BUG_NOMSR;
+
+	if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
+		autoconfig_irq(up);
+
+	if (port->type == PORT_UNKNOWN)
+		serial8250_release_std_resource(up);
+
+	register_dev_spec_attr_grp(up);
+	up->fcr = uart_config[up->port.type].fcr;
+}
+
+static int
+serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (ser->irq >= nr_irqs || ser->irq < 0 ||
+	    ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
+	    ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
+	    ser->type == PORT_STARTECH)
+		return -EINVAL;
+	return 0;
+}
+
+static const char *serial8250_type(struct uart_port *port)
+{
+	int type = port->type;
+
+	if (type >= ARRAY_SIZE(uart_config))
+		type = 0;
+	return uart_config[type].name;
+}
+
+static const struct uart_ops serial8250_pops = {
+	.tx_empty	= serial8250_tx_empty,
+	.set_mctrl	= serial8250_set_mctrl,
+	.get_mctrl	= serial8250_get_mctrl,
+	.stop_tx	= serial8250_stop_tx,
+	.start_tx	= serial8250_start_tx,
+	.throttle	= serial8250_throttle,
+	.unthrottle	= serial8250_unthrottle,
+	.stop_rx	= serial8250_stop_rx,
+	.enable_ms	= serial8250_enable_ms,
+	.break_ctl	= serial8250_break_ctl,
+	.startup	= serial8250_startup,
+	.shutdown	= serial8250_shutdown,
+	.set_termios	= serial8250_set_termios,
+	.set_ldisc	= serial8250_set_ldisc,
+	.pm		= serial8250_pm,
+	.type		= serial8250_type,
+	.release_port	= serial8250_release_port,
+	.request_port	= serial8250_request_port,
+	.config_port	= serial8250_config_port,
+	.verify_port	= serial8250_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = serial8250_get_poll_char,
+	.poll_put_char = serial8250_put_poll_char,
+#endif
+};
+
+void serial8250_init_port(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	spin_lock_init(&port->lock);
+	port->ctrl_id = 0;
+	port->pm = NULL;
+	port->ops = &serial8250_pops;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+
+	up->cur_iotype = 0xFF;
+}
+EXPORT_SYMBOL_GPL(serial8250_init_port);
+
+void serial8250_set_defaults(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	if (up->port.flags & UPF_FIXED_TYPE) {
+		unsigned int type = up->port.type;
+
+		if (!up->port.fifosize)
+			up->port.fifosize = uart_config[type].fifo_size;
+		if (!up->tx_loadsz)
+			up->tx_loadsz = uart_config[type].tx_loadsz;
+		if (!up->capabilities)
+			up->capabilities = uart_config[type].flags;
+	}
+
+	set_io_from_upio(port);
+
+	/* default dma handlers */
+	if (up->dma) {
+		if (!up->dma->tx_dma)
+			up->dma->tx_dma = serial8250_tx_dma;
+		if (!up->dma->rx_dma)
+			up->dma->rx_dma = serial8250_rx_dma;
+	}
+}
+EXPORT_SYMBOL_GPL(serial8250_set_defaults);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+static void serial8250_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	wait_for_xmitr(up, UART_LSR_THRE);
+	serial_port_out(port, UART_TX, ch);
+}
+
+/*
+ *	Restore serial console when h/w power-off detected
+ */
+static void serial8250_console_restore(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	struct ktermios termios;
+	unsigned int baud, quot, frac = 0;
+
+	termios.c_cflag = port->cons->cflag;
+	termios.c_ispeed = port->cons->ispeed;
+	termios.c_ospeed = port->cons->ospeed;
+	if (port->state->port.tty && termios.c_cflag == 0) {
+		termios.c_cflag = port->state->port.tty->termios.c_cflag;
+		termios.c_ispeed = port->state->port.tty->termios.c_ispeed;
+		termios.c_ospeed = port->state->port.tty->termios.c_ospeed;
+	}
+
+	baud = serial8250_get_baud_rate(port, &termios, NULL);
+	quot = serial8250_get_divisor(port, baud, &frac);
+
+	serial8250_set_divisor(port, baud, quot, frac);
+	serial_port_out(port, UART_LCR, up->lcr);
+	serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS);
+}
+
+/*
+ * Print a string to the serial port using the device FIFO
+ *
+ * It sends fifosize bytes and then waits for the fifo
+ * to get empty.
+ */
+static void serial8250_console_fifo_write(struct uart_8250_port *up,
+					  const char *s, unsigned int count)
+{
+	int i;
+	const char *end = s + count;
+	unsigned int fifosize = up->tx_loadsz;
+	bool cr_sent = false;
+
+	while (s != end) {
+		wait_for_lsr(up, UART_LSR_THRE);
+
+		for (i = 0; i < fifosize && s != end; ++i) {
+			if (*s == '\n' && !cr_sent) {
+				serial_out(up, UART_TX, '\r');
+				cr_sent = true;
+			} else {
+				serial_out(up, UART_TX, *s++);
+				cr_sent = false;
+			}
+		}
+	}
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ *
+ *	Doing runtime PM is really a bad idea for the kernel console.
+ *	Thus, we assume the function is called when device is powered up.
+ */
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count)
+{
+	struct uart_8250_em485 *em485 = up->em485;
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int ier, use_fifo;
+	int locked = 1;
+
+	touch_nmi_watchdog();
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_port_in(port, UART_IER);
+	serial8250_clear_IER(up);
+
+	/* check scratch reg to see if port powered off during system sleep */
+	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
+		serial8250_console_restore(up);
+		up->canary = 0;
+	}
+
+	if (em485) {
+		if (em485->tx_stopped)
+			up->rs485_start_tx(up);
+		mdelay(port->rs485.delay_rts_before_send);
+	}
+
+	use_fifo = (up->capabilities & UART_CAP_FIFO) &&
+		/*
+		 * BCM283x requires to check the fifo
+		 * after each byte.
+		 */
+		!(up->capabilities & UART_CAP_MINI) &&
+		/*
+		 * tx_loadsz contains the transmit fifo size
+		 */
+		up->tx_loadsz > 1 &&
+		(up->fcr & UART_FCR_ENABLE_FIFO) &&
+		port->state &&
+		test_bit(TTY_PORT_INITIALIZED, &port->state->port.iflags) &&
+		/*
+		 * After we put a data in the fifo, the controller will send
+		 * it regardless of the CTS state. Therefore, only use fifo
+		 * if we don't use control flow.
+		 */
+		!(up->port.flags & UPF_CONS_FLOW);
+
+	if (likely(use_fifo))
+		serial8250_console_fifo_write(up, s, count);
+	else
+		uart_console_write(port, s, count, serial8250_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
+
+	if (em485) {
+		mdelay(port->rs485.delay_rts_after_send);
+		if (em485->tx_stopped)
+			up->rs485_stop_tx(up);
+	}
+
+	serial_port_out(port, UART_IER, ier);
+
+	/*
+	 *	The receive handling will happen properly because the
+	 *	receive ready bit will still be set; it is not cleared
+	 *	on read.  However, modem control will not, we must
+	 *	call it if we have saved something in the saved flags
+	 *	while processing with interrupts off.
+	 */
+	if (up->msr_saved_flags)
+		serial8250_modem_status(up);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static unsigned int probe_baud(struct uart_port *port)
+{
+	unsigned char lcr, dll, dlm;
+	unsigned int quot;
+
+	lcr = serial_port_in(port, UART_LCR);
+	serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);
+	dll = serial_port_in(port, UART_DLL);
+	dlm = serial_port_in(port, UART_DLM);
+	serial_port_out(port, UART_LCR, lcr);
+
+	quot = (dlm << 8) | dll;
+	return (port->uartclk / 16) / quot;
+}
+
+int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
+{
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	if (!port->iobase && !port->membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else if (probe)
+		baud = probe_baud(port);
+
+	ret = uart_set_options(port, port->cons, baud, parity, bits, flow);
+	if (ret)
+		return ret;
+
+	if (port->dev)
+		pm_runtime_get_sync(port->dev);
+
+	return 0;
+}
+
+int serial8250_console_exit(struct uart_port *port)
+{
+	if (port->dev)
+		pm_runtime_put_sync(port->dev);
+
+	return 0;
+}
+
+#endif /* CONFIG_SERIAL_8250_CONSOLE */
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c
new file mode 100644
index 000000000..a5b3ea27f
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pxa.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS
+ *  Copyright:	(C) 2013 Sergei Ianovich <ynvich@gmail.com>
+ *
+ *  replaces drivers/serial/pxa.c by Nicolas Pitre
+ *  Created:	Feb 20, 2003
+ *  Copyright:	(C) 2003 Monta Vista Software, Inc.
+ *
+ *  Based on drivers/serial/8250.c by Russell King.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+
+#include "8250.h"
+
+struct pxa8250_data {
+	int			line;
+	struct clk		*clk;
+};
+
+static int __maybe_unused serial_pxa_suspend(struct device *dev)
+{
+	struct pxa8250_data *data = dev_get_drvdata(dev);
+
+	serial8250_suspend_port(data->line);
+
+	return 0;
+}
+
+static int __maybe_unused serial_pxa_resume(struct device *dev)
+{
+	struct pxa8250_data *data = dev_get_drvdata(dev);
+
+	serial8250_resume_port(data->line);
+
+	return 0;
+}
+
+static const struct dev_pm_ops serial_pxa_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)
+};
+
+static const struct of_device_id serial_pxa_dt_ids[] = {
+	{ .compatible = "mrvl,pxa-uart", },
+	{ .compatible = "mrvl,mmp-uart", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
+
+/* Uart divisor latch write */
+static void serial_pxa_dl_write(struct uart_8250_port *up, u32 value)
+{
+	unsigned int dll;
+
+	serial_out(up, UART_DLL, value & 0xff);
+	/*
+	 * work around Erratum #74 according to Marvel(R) PXA270M Processor
+	 * Specification Update (April 19, 2010)
+	 */
+	dll = serial_in(up, UART_DLL);
+	WARN_ON(dll != (value & 0xff));
+
+	serial_out(up, UART_DLM, value >> 8 & 0xff);
+}
+
+
+static void serial_pxa_pm(struct uart_port *port, unsigned int state,
+	      unsigned int oldstate)
+{
+	struct pxa8250_data *data = port->private_data;
+
+	if (!state)
+		clk_prepare_enable(data->clk);
+	else
+		clk_disable_unprepare(data->clk);
+}
+
+static int serial_pxa_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port uart = {};
+	struct pxa8250_data *data;
+	struct resource *mmres;
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mmres)
+		return -ENODEV;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(data->clk))
+		return PTR_ERR(data->clk);
+
+	ret = clk_prepare(data->clk);
+	if (ret)
+		return ret;
+
+	ret = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (ret >= 0)
+		uart.port.line = ret;
+
+	uart.port.type = PORT_XSCALE;
+	uart.port.iotype = UPIO_MEM32;
+	uart.port.mapbase = mmres->start;
+	uart.port.regshift = 2;
+	uart.port.irq = irq;
+	uart.port.fifosize = 64;
+	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
+	uart.port.dev = &pdev->dev;
+	uart.port.uartclk = clk_get_rate(data->clk);
+	uart.port.pm = serial_pxa_pm;
+	uart.port.private_data = data;
+	uart.dl_write = serial_pxa_dl_write;
+
+	ret = serial8250_register_8250_port(&uart);
+	if (ret < 0)
+		goto err_clk;
+
+	data->line = ret;
+
+	platform_set_drvdata(pdev, data);
+
+	return 0;
+
+ err_clk:
+	clk_unprepare(data->clk);
+	return ret;
+}
+
+static int serial_pxa_remove(struct platform_device *pdev)
+{
+	struct pxa8250_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+
+	clk_unprepare(data->clk);
+
+	return 0;
+}
+
+static struct platform_driver serial_pxa_driver = {
+	.probe          = serial_pxa_probe,
+	.remove         = serial_pxa_remove,
+
+	.driver		= {
+		.name	= "pxa2xx-uart",
+		.pm	= &serial_pxa_pm_ops,
+		.of_match_table = serial_pxa_dt_ids,
+	},
+};
+
+module_platform_driver(serial_pxa_driver);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static int __init early_serial_pxa_setup(struct earlycon_device *device,
+				  const char *options)
+{
+	struct uart_port *port = &device->port;
+
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+
+	port->regshift = 2;
+	return early_serial8250_setup(device, NULL);
+}
+OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
+OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup);
+#endif
+
+MODULE_AUTHOR("Sergei Ianovich");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pxa2xx-uart");
diff --git a/drivers/tty/serial/8250/8250_rt288x.c b/drivers/tty/serial/8250/8250_rt288x.c
new file mode 100644
index 000000000..6415ca8d3
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_rt288x.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RT288x/Au1xxx driver
+ */
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+#define RT288X_DL	0x28
+
+/* Au1x00/RT288x UART hardware has a weird register layout */
+static const u8 au_io_in_map[7] = {
+	[UART_RX]	= 0,
+	[UART_IER]	= 2,
+	[UART_IIR]	= 3,
+	[UART_LCR]	= 5,
+	[UART_MCR]	= 6,
+	[UART_LSR]	= 7,
+	[UART_MSR]	= 8,
+};
+
+static const u8 au_io_out_map[5] = {
+	[UART_TX]	= 1,
+	[UART_IER]	= 2,
+	[UART_FCR]	= 4,
+	[UART_LCR]	= 5,
+	[UART_MCR]	= 6,
+};
+
+static unsigned int au_serial_in(struct uart_port *p, int offset)
+{
+	if (offset >= ARRAY_SIZE(au_io_in_map))
+		return UINT_MAX;
+	offset = au_io_in_map[offset];
+
+	return __raw_readl(p->membase + (offset << p->regshift));
+}
+
+static void au_serial_out(struct uart_port *p, int offset, int value)
+{
+	if (offset >= ARRAY_SIZE(au_io_out_map))
+		return;
+	offset = au_io_out_map[offset];
+
+	__raw_writel(value, p->membase + (offset << p->regshift));
+}
+
+/* Au1x00 haven't got a standard divisor latch */
+static u32 au_serial_dl_read(struct uart_8250_port *up)
+{
+	return __raw_readl(up->port.membase + RT288X_DL);
+}
+
+static void au_serial_dl_write(struct uart_8250_port *up, u32 value)
+{
+	__raw_writel(value, up->port.membase + RT288X_DL);
+}
+
+int au_platform_setup(struct plat_serial8250_port *p)
+{
+	p->iotype = UPIO_AU;
+
+	p->serial_in = au_serial_in;
+	p->serial_out = au_serial_out;
+	p->dl_read = au_serial_dl_read;
+	p->dl_write = au_serial_dl_write;
+
+	p->mapsize = 0x1000;
+
+	p->bugs |= UART_BUG_NOMSR;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(au_platform_setup);
+
+int rt288x_setup(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+
+	p->iotype = UPIO_AU;
+
+	p->serial_in = au_serial_in;
+	p->serial_out = au_serial_out;
+	up->dl_read = au_serial_dl_read;
+	up->dl_write = au_serial_dl_write;
+
+	p->mapsize = 0x100;
+
+	up->bugs |= UART_BUG_NOMSR;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rt288x_setup);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static void au_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned int status;
+
+	au_serial_out(port, UART_TX, c);
+
+	for (;;) {
+		status = au_serial_in(port, UART_LSR);
+		if (uart_lsr_tx_empty(status))
+			break;
+		cpu_relax();
+	}
+}
+
+static void au_early_serial8250_write(struct console *console,
+				      const char *s, unsigned int count)
+{
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+
+	uart_console_write(port, s, count, au_putc);
+}
+
+static int __init early_au_setup(struct earlycon_device *dev, const char *opt)
+{
+	rt288x_setup(&dev->port);
+	dev->con->write = au_early_serial8250_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup);
+#endif
+
+MODULE_DESCRIPTION("RT288x/Au1xxx UART driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_tegra.c b/drivers/tty/serial/8250/8250_tegra.c
new file mode 100644
index 000000000..89956bbf3
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_tegra.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Serial Port driver for Tegra devices
+ *
+ *  Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#include "8250.h"
+
+struct tegra_uart {
+	struct clk *clk;
+	struct reset_control *rst;
+	int line;
+};
+
+static void tegra_uart_handle_break(struct uart_port *p)
+{
+	unsigned int status, tmout = 10000;
+
+	while (1) {
+		status = p->serial_in(p, UART_LSR);
+		if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)))
+			break;
+
+		p->serial_in(p, UART_RX);
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	}
+}
+
+static int tegra_uart_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port port8250;
+	struct tegra_uart *uart;
+	struct uart_port *port;
+	struct resource *res;
+	int ret;
+
+	uart = devm_kzalloc(&pdev->dev, sizeof(*uart), GFP_KERNEL);
+	if (!uart)
+		return -ENOMEM;
+
+	memset(&port8250, 0, sizeof(port8250));
+
+	port = &port8250.port;
+	spin_lock_init(&port->lock);
+
+	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
+		      UPF_FIXED_TYPE;
+	port->iotype = UPIO_MEM32;
+	port->regshift = 2;
+	port->type = PORT_TEGRA;
+	port->irqflags |= IRQF_SHARED;
+	port->dev = &pdev->dev;
+	port->handle_break = tegra_uart_handle_break;
+
+	ret = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (ret >= 0)
+		port->line = ret;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+
+	port->irq = ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	port->membase = devm_ioremap(&pdev->dev, res->start,
+				     resource_size(res));
+	if (!port->membase)
+		return -ENOMEM;
+
+	port->mapbase = res->start;
+	port->mapsize = resource_size(res);
+
+	uart->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+	if (IS_ERR(uart->rst))
+		return PTR_ERR(uart->rst);
+
+	if (device_property_read_u32(&pdev->dev, "clock-frequency",
+				     &port->uartclk)) {
+		uart->clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(uart->clk)) {
+			dev_err(&pdev->dev, "failed to get clock!\n");
+			return -ENODEV;
+		}
+
+		ret = clk_prepare_enable(uart->clk);
+		if (ret < 0)
+			return ret;
+
+		port->uartclk = clk_get_rate(uart->clk);
+	}
+
+	ret = reset_control_deassert(uart->rst);
+	if (ret)
+		goto err_clkdisable;
+
+	ret = serial8250_register_8250_port(&port8250);
+	if (ret < 0)
+		goto err_ctrl_assert;
+
+	platform_set_drvdata(pdev, uart);
+	uart->line = ret;
+
+	return 0;
+
+err_ctrl_assert:
+	reset_control_assert(uart->rst);
+err_clkdisable:
+	clk_disable_unprepare(uart->clk);
+
+	return ret;
+}
+
+static int tegra_uart_remove(struct platform_device *pdev)
+{
+	struct tegra_uart *uart = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(uart->line);
+	reset_control_assert(uart->rst);
+	clk_disable_unprepare(uart->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_uart_suspend(struct device *dev)
+{
+	struct tegra_uart *uart = dev_get_drvdata(dev);
+	struct uart_8250_port *port8250 = serial8250_get_port(uart->line);
+	struct uart_port *port = &port8250->port;
+
+	serial8250_suspend_port(uart->line);
+
+	if (!uart_console(port) || console_suspend_enabled)
+		clk_disable_unprepare(uart->clk);
+
+	return 0;
+}
+
+static int tegra_uart_resume(struct device *dev)
+{
+	struct tegra_uart *uart = dev_get_drvdata(dev);
+	struct uart_8250_port *port8250 = serial8250_get_port(uart->line);
+	struct uart_port *port = &port8250->port;
+
+	if (!uart_console(port) || console_suspend_enabled)
+		clk_prepare_enable(uart->clk);
+
+	serial8250_resume_port(uart->line);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(tegra_uart_pm_ops, tegra_uart_suspend,
+			 tegra_uart_resume);
+
+static const struct of_device_id tegra_uart_of_match[] = {
+	{ .compatible = "nvidia,tegra20-uart", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
+
+static const struct acpi_device_id tegra_uart_acpi_match[] __maybe_unused = {
+	{ "NVDA0100", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, tegra_uart_acpi_match);
+
+static struct platform_driver tegra_uart_driver = {
+	.driver = {
+		.name = "tegra-uart",
+		.pm = &tegra_uart_pm_ops,
+		.of_match_table = tegra_uart_of_match,
+		.acpi_match_table = ACPI_PTR(tegra_uart_acpi_match),
+	},
+	.probe = tegra_uart_probe,
+	.remove = tegra_uart_remove,
+};
+
+module_platform_driver(tegra_uart_driver);
+
+MODULE_AUTHOR("Jeff Brasen <jbrasen@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra 8250 Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/8250/8250_uniphier.c b/drivers/tty/serial/8250/8250_uniphier.c
new file mode 100644
index 000000000..a40515526
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_uniphier.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "8250.h"
+
+/*
+ * This hardware is similar to 8250, but its register map is a bit different:
+ *   - MMIO32 (regshift = 2)
+ *   - FCR is not at 2, but 3
+ *   - LCR and MCR are not at 3 and 4, they share 4
+ *   - No SCR (Instead, CHAR can be used as a scratch register)
+ *   - Divisor latch at 9, no divisor latch access bit
+ */
+
+#define UNIPHIER_UART_REGSHIFT		2
+
+/* bit[15:8] = CHAR, bit[7:0] = FCR */
+#define UNIPHIER_UART_CHAR_FCR		(3 << (UNIPHIER_UART_REGSHIFT))
+/* bit[15:8] = LCR, bit[7:0] = MCR */
+#define UNIPHIER_UART_LCR_MCR		(4 << (UNIPHIER_UART_REGSHIFT))
+/* Divisor Latch Register */
+#define UNIPHIER_UART_DLR		(9 << (UNIPHIER_UART_REGSHIFT))
+
+struct uniphier8250_priv {
+	int line;
+	struct clk *clk;
+	spinlock_t atomic_write_lock;
+};
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static int __init uniphier_early_console_setup(struct earlycon_device *device,
+					       const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	/* This hardware always expects MMIO32 register interface. */
+	device->port.iotype = UPIO_MEM32;
+	device->port.regshift = UNIPHIER_UART_REGSHIFT;
+
+	/*
+	 * Do not touch the divisor register in early_serial8250_setup();
+	 * we assume it has been initialized by a boot loader.
+	 */
+	device->baud = 0;
+
+	return early_serial8250_setup(device, options);
+}
+OF_EARLYCON_DECLARE(uniphier, "socionext,uniphier-uart",
+		    uniphier_early_console_setup);
+#endif
+
+/*
+ * The register map is slightly different from that of 8250.
+ * IO callbacks must be overridden for correct access to FCR, LCR, MCR and SCR.
+ */
+static unsigned int uniphier_serial_in(struct uart_port *p, int offset)
+{
+	unsigned int valshift = 0;
+
+	switch (offset) {
+	case UART_SCR:
+		/* No SCR for this hardware.  Use CHAR as a scratch register */
+		valshift = 8;
+		offset = UNIPHIER_UART_CHAR_FCR;
+		break;
+	case UART_LCR:
+		valshift = 8;
+		fallthrough;
+	case UART_MCR:
+		offset = UNIPHIER_UART_LCR_MCR;
+		break;
+	default:
+		offset <<= UNIPHIER_UART_REGSHIFT;
+		break;
+	}
+
+	/*
+	 * The return value must be masked with 0xff because some registers
+	 * share the same offset that must be accessed by 32-bit write/read.
+	 * 8 or 16 bit access to this hardware result in unexpected behavior.
+	 */
+	return (readl(p->membase + offset) >> valshift) & 0xff;
+}
+
+static void uniphier_serial_out(struct uart_port *p, int offset, int value)
+{
+	unsigned int valshift = 0;
+	bool normal = false;
+
+	switch (offset) {
+	case UART_SCR:
+		/* No SCR for this hardware.  Use CHAR as a scratch register */
+		valshift = 8;
+		fallthrough;
+	case UART_FCR:
+		offset = UNIPHIER_UART_CHAR_FCR;
+		break;
+	case UART_LCR:
+		valshift = 8;
+		/* Divisor latch access bit does not exist. */
+		value &= ~UART_LCR_DLAB;
+		fallthrough;
+	case UART_MCR:
+		offset = UNIPHIER_UART_LCR_MCR;
+		break;
+	default:
+		offset <<= UNIPHIER_UART_REGSHIFT;
+		normal = true;
+		break;
+	}
+
+	if (normal) {
+		writel(value, p->membase + offset);
+	} else {
+		/*
+		 * Special case: two registers share the same address that
+		 * must be 32-bit accessed.  As this is not longer atomic safe,
+		 * take a lock just in case.
+		 */
+		struct uniphier8250_priv *priv = p->private_data;
+		unsigned long flags;
+		u32 tmp;
+
+		spin_lock_irqsave(&priv->atomic_write_lock, flags);
+		tmp = readl(p->membase + offset);
+		tmp &= ~(0xff << valshift);
+		tmp |= value << valshift;
+		writel(tmp, p->membase + offset);
+		spin_unlock_irqrestore(&priv->atomic_write_lock, flags);
+	}
+}
+
+/*
+ * This hardware does not have the divisor latch access bit.
+ * The divisor latch register exists at different address.
+ * Override dl_read/write callbacks.
+ */
+static u32 uniphier_serial_dl_read(struct uart_8250_port *up)
+{
+	return readl(up->port.membase + UNIPHIER_UART_DLR);
+}
+
+static void uniphier_serial_dl_write(struct uart_8250_port *up, u32 value)
+{
+	writel(value, up->port.membase + UNIPHIER_UART_DLR);
+}
+
+static int uniphier_uart_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uart_8250_port up;
+	struct uniphier8250_priv *priv;
+	struct resource *regs;
+	void __iomem *membase;
+	int irq;
+	int ret;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(dev, "failed to get memory resource\n");
+		return -EINVAL;
+	}
+
+	membase = devm_ioremap(dev, regs->start, resource_size(regs));
+	if (!membase)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	memset(&up, 0, sizeof(up));
+
+	ret = of_alias_get_id(dev->of_node, "serial");
+	if (ret < 0) {
+		dev_err(dev, "failed to get alias id\n");
+		return ret;
+	}
+	up.port.line = ret;
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "failed to get clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	up.port.uartclk = clk_get_rate(priv->clk);
+
+	spin_lock_init(&priv->atomic_write_lock);
+
+	up.port.dev = dev;
+	up.port.private_data = priv;
+	up.port.mapbase = regs->start;
+	up.port.mapsize = resource_size(regs);
+	up.port.membase = membase;
+	up.port.irq = irq;
+
+	up.port.type = PORT_16550A;
+	up.port.iotype = UPIO_MEM32;
+	up.port.fifosize = 64;
+	up.port.regshift = UNIPHIER_UART_REGSHIFT;
+	up.port.flags = UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	up.capabilities = UART_CAP_FIFO;
+
+	if (of_property_read_bool(dev->of_node, "auto-flow-control"))
+		up.capabilities |= UART_CAP_AFE;
+
+	up.port.serial_in = uniphier_serial_in;
+	up.port.serial_out = uniphier_serial_out;
+	up.dl_read = uniphier_serial_dl_read;
+	up.dl_write = uniphier_serial_dl_write;
+
+	ret = serial8250_register_8250_port(&up);
+	if (ret < 0) {
+		dev_err(dev, "failed to register 8250 port\n");
+		clk_disable_unprepare(priv->clk);
+		return ret;
+	}
+	priv->line = ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int uniphier_uart_remove(struct platform_device *pdev)
+{
+	struct uniphier8250_priv *priv = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(priv->line);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused uniphier_uart_suspend(struct device *dev)
+{
+	struct uniphier8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+
+	serial8250_suspend_port(priv->line);
+
+	if (!uart_console(&up->port) || console_suspend_enabled)
+		clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused uniphier_uart_resume(struct device *dev)
+{
+	struct uniphier8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
+	int ret;
+
+	if (!uart_console(&up->port) || console_suspend_enabled) {
+		ret = clk_prepare_enable(priv->clk);
+		if (ret)
+			return ret;
+	}
+
+	serial8250_resume_port(priv->line);
+
+	return 0;
+}
+
+static const struct dev_pm_ops uniphier_uart_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(uniphier_uart_suspend, uniphier_uart_resume)
+};
+
+static const struct of_device_id uniphier_uart_match[] = {
+	{ .compatible = "socionext,uniphier-uart" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_uart_match);
+
+static struct platform_driver uniphier_uart_platform_driver = {
+	.probe		= uniphier_uart_probe,
+	.remove		= uniphier_uart_remove,
+	.driver = {
+		.name	= "uniphier-uart",
+		.of_match_table = uniphier_uart_match,
+		.pm = &uniphier_uart_pm_ops,
+	},
+};
+module_platform_driver(uniphier_uart_platform_driver);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_DESCRIPTION("UniPhier UART driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
new file mode 100644
index 000000000..ee17cf5c4
--- /dev/null
+++ b/drivers/tty/serial/8250/Kconfig
@@ -0,0 +1,577 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# The 8250/16550 serial drivers.  You shouldn't be in this list unless
+# you somehow have an implicit or explicit dependency on SERIAL_8250.
+#
+
+config SERIAL_8250
+	tristate "8250/16550 and compatible serial support"
+	depends on !S390
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  This selects whether you want to include the driver for the standard
+	  serial ports.  The standard answer is Y.  People who might say N
+	  here are those that are setting up dedicated Ethernet WWW/FTP
+	  servers, or users that have one of the various bus mice instead of a
+	  serial mouse and don't intend to use their machine's standard serial
+	  port for anything.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called 8250.
+	  [WARNING: Do not compile this driver as a module if you are using
+	  non-standard serial ports, since the configuration information will
+	  be lost when the driver is unloaded.  This limitation may be lifted
+	  in the future.]
+
+	  BTW1: If you have a mouseman serial mouse which is not recognized by
+	  the X window system, try running gpm first.
+
+	  BTW2: If you intend to use a software modem (also called Winmodem)
+	  under Linux, forget it.  These modems are crippled and require
+	  proprietary drivers which are only available under Windows.
+
+	  Most people will say Y or M here, so that they can use serial mice,
+	  modems and similar devices connecting to the standard serial ports.
+
+config SERIAL_8250_DEPRECATED_OPTIONS
+	bool "Support 8250_core.* kernel options (DEPRECATED)"
+	depends on SERIAL_8250
+	default y
+	help
+	  In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to
+	  accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
+	  8250.nr_uarts=4. We now renamed the module back to 8250, but if
+	  anybody noticed in 3.7 and changed their userspace we still have to
+	  keep the 8250_core.* options around until they revert the changes
+	  they already did.
+
+	  If 8250 is built as a module, this adds 8250_core alias instead. 
+
+	  If you did not notice yet and/or you have userspace from pre-3.7, it
+	  is safe (and recommended) to say N here.
+
+config SERIAL_8250_PNP
+	bool "8250/16550 PNP device support" if EXPERT
+	depends on SERIAL_8250 && PNP
+	default y
+	help
+	  This builds standard PNP serial support. You may be able to
+	  disable this feature if you only need legacy serial support.
+
+config SERIAL_8250_16550A_VARIANTS
+	bool "Support for variants of the 16550A serial port"
+	depends on SERIAL_8250
+	default !X86
+	help
+	  The 8250 driver can probe for many variants of the venerable 16550A
+	  serial port. Doing so takes additional time at boot.
+
+	  On modern systems, especially those using serial only for a simple
+	  console, you can say N here.
+
+config SERIAL_8250_FINTEK
+	bool "Support for Fintek variants"
+	depends on SERIAL_8250
+	help
+	  Selecting this option will add support for the RS232 and RS485
+	  capabilities of the Fintek F81216A LPC to 4 UART as well similar
+	  variants.
+
+	  If this option is not selected the device will be configured as a
+	  standard 16550A serial port, however the device may not function
+	  correctly without this option enabled.
+
+	  If unsure, say N.
+
+config SERIAL_8250_CONSOLE
+	bool "Console on 8250/16550 and compatible serial port"
+	depends on SERIAL_8250=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  If you say Y here, it will be possible to use a serial port as the
+	  system console (the system console is the device which receives all
+	  kernel messages and warnings and which allows logins in single user
+	  mode). This could be useful if some terminal or printer is connected
+	  to that serial port.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyS1". (Try "man bootparam" or see the documentation of
+	  your boot loader (grub or lilo or loadlin) about how to pass options
+	  to the kernel at boot time.)
+
+	  If you don't have a VGA card installed and you say Y here, the
+	  kernel will automatically use the first serial line, /dev/ttyS0, as
+	  system console.
+
+	  You can set that using a kernel command line option such as
+	  "console=uart8250,io,0x3f8,9600n8"
+	  "console=uart8250,mmio,0xff5e0000,115200n8".
+	  and it will switch to normal serial console when the corresponding
+	  port is ready.
+	  "earlycon=uart8250,io,0x3f8,9600n8"
+	  "earlycon=uart8250,mmio,0xff5e0000,115200n8".
+	  it will not only setup early console.
+
+	  If unsure, say N.
+
+config SERIAL_8250_PARISC
+	tristate
+	depends on SERIAL_8250 && PARISC
+	default SERIAL_8250
+
+config SERIAL_8250_DMA
+	bool "DMA support for 16550 compatible UART controllers" if EXPERT
+	depends on SERIAL_8250 && DMADEVICES=y
+	default SERIAL_8250
+	help
+	  This builds DMA support that can be used with 8250/16650
+	  compatible UART controllers that support DMA signaling.
+
+config SERIAL_8250_PCILIB
+	bool
+
+config SERIAL_8250_PCI
+	tristate "8250/16550 PCI device support"
+	depends on SERIAL_8250 && PCI
+	select SERIAL_8250_PCILIB
+	default SERIAL_8250
+	help
+	  This builds standard PCI serial support. You may be able to
+	  disable this feature if you only need legacy serial support.
+	  Saves about 9K.
+	  Note that serial ports on NetMos 9835 Multi-I/O cards are handled
+	  by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
+
+config SERIAL_8250_EXAR
+	tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
+	depends on SERIAL_8250_PCI
+	default SERIAL_8250
+	help
+	  This builds support for XR17C1xx, XR17V3xx and some Commtech
+	  422x PCIe serial cards that are not covered by the more generic
+	  SERIAL_8250_PCI option.
+
+config SERIAL_8250_HP300
+	tristate
+	depends on SERIAL_8250 && HP300
+	default SERIAL_8250
+
+config SERIAL_8250_CS
+	tristate "8250/16550 PCMCIA device support"
+	depends on PCMCIA && SERIAL_8250
+	help
+	  Say Y here to enable support for 16-bit PCMCIA serial devices,
+	  including serial port cards, modems, and the modem functions of
+	  multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
+	  credit-card size devices often used with laptops.)
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called serial_cs.
+
+	  If unsure, say N.
+
+config SERIAL_8250_MEN_MCB
+	tristate "MEN MCB UART device support"
+	depends on MCB && SERIAL_8250
+	help
+	  This enables support for FPGA based UARTs found on many MEN
+	  boards. This driver enables support for the 16z025, 16z057
+	  and 16z125 UARTs.
+
+	  To compile this driver as a module, chose M here: the
+	  module will be called 8250_men_mcb.
+
+
+config SERIAL_8250_NR_UARTS
+	int "Maximum number of 8250/16550 serial ports"
+	depends on SERIAL_8250
+	default "4"
+	help
+	  Set this to the number of serial ports you want the driver
+	  to support.  This includes any ports discovered via ACPI or
+	  PCI enumeration and any ports that may be added at run-time
+	  via hot-plug, or any ISA multi-port serial cards.
+
+config SERIAL_8250_RUNTIME_UARTS
+	int "Number of 8250/16550 serial ports to register at runtime"
+	depends on SERIAL_8250
+	range 0 SERIAL_8250_NR_UARTS
+	default "4"
+	help
+	  Set this to the maximum number of serial ports you want
+	  the kernel to register at boot time.  This can be overridden
+	  with the module parameter "nr_uarts", or boot-time parameter
+	  8250.nr_uarts
+
+config SERIAL_8250_EXTENDED
+	bool "Extended 8250/16550 serial driver options"
+	depends on SERIAL_8250
+	help
+	  If you wish to use any non-standard features of the standard "dumb"
+	  driver, say Y here. This includes HUB6 support, shared serial
+	  interrupts, special multiport support, support for more than the
+	  four COM 1/2/3/4 boards, etc.
+
+	  Note that the answer to this question won't directly affect the
+	  kernel: saying N will just cause the configurator to skip all
+	  the questions about serial driver options. If unsure, say N.
+
+config SERIAL_8250_MANY_PORTS
+	bool "Support more than 4 legacy serial ports"
+	depends on SERIAL_8250_EXTENDED && !IA64
+	help
+	  Say Y here if you have dumb serial boards other than the four
+	  standard COM 1/2/3/4 ports. This may happen if you have an AST
+	  FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
+	  from <https://www.tldp.org/docs.html#howto>), or other custom
+	  serial port hardware which acts similar to standard serial port
+	  hardware. If you only use the standard COM 1/2/3/4 ports, you can
+	  say N here to save some memory. You can also say Y if you have an
+	  "intelligent" multiport card such as Digiboards, etc.
+
+#
+# Multi-port serial cards
+#
+
+config SERIAL_8250_FOURPORT
+	tristate "Support Fourport cards"
+	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
+	help
+	  Say Y here if you have an AST FourPort serial board.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 8250_fourport.
+
+config SERIAL_8250_ACCENT
+	tristate "Support Accent cards"
+	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
+	help
+	  Say Y here if you have an Accent Async serial board.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 8250_accent.
+
+config SERIAL_8250_ASPEED_VUART
+	tristate "Aspeed Virtual UART"
+	depends on SERIAL_8250
+	depends on OF
+	depends on MFD_SYSCON
+	depends on ARCH_ASPEED || COMPILE_TEST
+	select REGMAP
+	help
+	  If you want to use the virtual UART (VUART) device on Aspeed
+	  BMC platforms, enable this option. This enables the 16550A-
+	  compatible device on the local LPC bus, giving a UART device
+	  with no physical RS232 connections.
+
+config SERIAL_8250_BOCA
+	tristate "Support Boca cards"
+	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
+	help
+	  Say Y here if you have a Boca serial board.  Please read the Boca
+	  mini-HOWTO, available from <https://www.tldp.org/docs.html#howto>
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 8250_boca.
+
+config SERIAL_8250_EXAR_ST16C554
+	tristate "Support Exar ST16C554/554D Quad UART"
+	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
+	help
+	  The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
+	  tinkering with your Envoy TU301, or have a machine with this UART,
+	  say Y here.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 8250_exar_st16c554.
+
+config SERIAL_8250_HUB6
+	tristate "Support Hub6 cards"
+	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
+	help
+	  Say Y here if you have a HUB6 serial board.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 8250_hub6.
+
+config SERIAL_8250_PCI1XXXX
+	tristate "Microchip 8250 based serial port"
+	depends on SERIAL_8250 && PCI
+	select SERIAL_8250_PCILIB
+	help
+	 Select this option if you have a setup with Microchip PCIe
+	 Switch with serial port enabled and wish to enable 8250
+	 serial driver for the serial interface. This driver support
+	 will ensure to support baud rates upto 1.5Mpbs.
+
+#
+# Misc. options/drivers.
+#
+
+config SERIAL_8250_SHARE_IRQ
+	bool "Support for sharing serial interrupts"
+	depends on SERIAL_8250_EXTENDED
+	help
+	  Some serial boards have hardware support which allows multiple dumb
+	  serial ports on the same board to share a single IRQ. To enable
+	  support for this in the serial driver, say Y here.
+
+config SERIAL_8250_DETECT_IRQ
+	bool "Autodetect IRQ on standard ports (unsafe)"
+	depends on SERIAL_8250_EXTENDED
+	help
+	  Say Y here if you want the kernel to try to guess which IRQ
+	  to use for your serial port.
+
+	  This is considered unsafe; it is far better to configure the IRQ in
+	  a boot script using the setserial command.
+
+	  If unsure, say N.
+
+config SERIAL_8250_RSA
+	bool "Support RSA serial ports"
+	depends on SERIAL_8250_EXTENDED
+	help
+	  Say Y here if you have a IODATA RSA-DV II/S ISA card and
+	  would like to use its >115kbps speeds.
+	  You will need to provide module parameter "probe_rsa", or boot-time
+	  parameter 8250.probe_rsa with I/O addresses of this card then.
+
+	  If you don't have such card, or if unsure, say N.
+
+config SERIAL_8250_DWLIB
+	bool
+
+config SERIAL_8250_ACORN
+	tristate "Acorn expansion card serial port support"
+	depends on ARCH_ACORN && SERIAL_8250
+	help
+	  If you have an Atomwide Serial card or Serial Port card for an Acorn
+	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
+	  cards.  If unsure, say N.
+
+config SERIAL_8250_BCM2835AUX
+	tristate "BCM2835 auxiliar mini UART support"
+	depends on ARCH_BCM2835 || COMPILE_TEST
+	depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
+	help
+	  Support for the BCM2835 auxiliar mini UART.
+
+	  Features and limitations of the UART are
+	    Registers are similar to 16650 registers,
+	      set bits in the control registers that are unsupported
+	      are ignored and read back as 0
+	    7/8 bit operation with 1 start and 1 stop bit
+	    8 symbols deep fifo for rx and tx
+	    SW controlled RTS and SW readable CTS
+	    Clock rate derived from system clock
+	    Uses 8 times oversampling (compared to 16 times for 16650)
+	    Missing break detection (but break generation)
+	    Missing framing error detection
+	    Missing parity bit
+	    Missing receive time-out interrupt
+	    Missing DCD, DSR, DTR and RI signals
+
+	  If unsure, say N.
+
+config SERIAL_8250_FSL
+	tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64)
+	depends on SERIAL_8250
+	default SERIAL_8250 if PPC || ARM || ARM64
+	help
+	  Selecting this option enables a workaround for a break-detection
+	  erratum for Freescale 16550 UARTs in the 8250 driver. It also
+	  enables support for ACPI enumeration.
+
+config SERIAL_8250_DFL
+	tristate "DFL bus driver for Altera 16550 UART"
+	depends on SERIAL_8250 && FPGA_DFL
+	help
+	  This option enables support for a Device Feature List (DFL) bus
+	  driver for the Altera 16550 UART. One or more Altera 16550 UARTs
+	  can be instantiated in a FPGA and then be discovered during
+	  enumeration of the DFL bus.
+
+	  To compile this driver as a module, chose M here: the
+	  module will be called 8250_dfl.
+
+config SERIAL_8250_DW
+	tristate "Support for Synopsys DesignWare 8250 quirks"
+	depends on SERIAL_8250
+	select SERIAL_8250_DWLIB
+	help
+	  Selecting this option will enable handling of the extra features
+	  present in the Synopsys DesignWare APB UART.
+
+config SERIAL_8250_EM
+	tristate "Support for Emma Mobile integrated serial port"
+	depends on SERIAL_8250 && HAVE_CLK
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  Selecting this option will add support for the integrated serial
+	  port hardware found on the Emma Mobile line of processors.
+	  If unsure, say N.
+
+config SERIAL_8250_IOC3
+	tristate "SGI IOC3 8250 UART support"
+	depends on SERIAL_8250
+	depends on SGI_MFD_IOC3 || COMPILE_TEST
+	select SERIAL_8250_EXTENDED
+	select SERIAL_8250_SHARE_IRQ
+	help
+	  Enable this if you have a SGI Origin or Octane machine. This module
+	  provides basic serial support by directly driving the UART chip
+	  behind the IOC3 device on those systems.  Maximum baud speed is
+	  38400bps using this driver.
+
+config SERIAL_8250_RT288X
+	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
+	depends on SERIAL_8250
+	default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
+	help
+	  Selecting this option will add support for the alternate register
+	  layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
+	  If unsure, say N.
+
+config SERIAL_8250_OMAP
+	tristate "Support for OMAP internal UART (8250 based driver)"
+	depends on SERIAL_8250
+	depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST
+	help
+	  If you have a machine based on an Texas Instruments OMAP CPU you
+	  can enable its onboard serial ports by enabling this option.
+
+	  This driver uses ttyS instead of ttyO.
+
+config SERIAL_8250_OMAP_TTYO_FIXUP
+	bool "Replace ttyO with ttyS"
+	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
+	default y
+	help
+	  This option replaces the "console=ttyO" argument with the matching
+	  ttyS argument if the user did not specified it on the command line.
+	  This ensures that the user can see the kernel output during boot
+	  which he wouldn't see otherwise. The getty has still to be configured
+	  for ttyS instead of ttyO regardless of this option.
+	  This option is intended for people who "automatically" enable this
+	  driver without knowing that this driver requires a different console=
+	  argument. If you read this, please keep this option disabled and
+	  instead update your kernel command line. If you prepare a kernel for a
+	  distribution or other kind of larger user base then you probably want
+	  to keep this option enabled. Otherwise people might complain about a
+	  not booting kernel because the serial console remains silent in case
+	  they forgot to update the command line.
+
+config SERIAL_8250_LPC18XX
+	tristate "NXP LPC18xx/43xx serial port support"
+	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
+	default ARCH_LPC18XX
+	help
+	  If you have a LPC18xx/43xx based board and want to use the
+	  serial port, say Y to this option. If unsure, say Y.
+
+config SERIAL_8250_MT6577
+	tristate "Mediatek serial port support"
+	depends on SERIAL_8250
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  If you have a Mediatek based board and want to use the
+	  serial port, say Y to this option. If unsure, say N.
+
+config SERIAL_8250_UNIPHIER
+	tristate "Support for UniPhier on-chip UART"
+	depends on SERIAL_8250
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	help
+	  If you have a UniPhier based board and want to use the on-chip
+	  serial ports, say Y to this option. If unsure, say N.
+
+config SERIAL_8250_INGENIC
+	tristate "Support for Ingenic SoC serial ports"
+	depends on SERIAL_8250
+	depends on OF_FLATTREE
+	depends on MIPS || COMPILE_TEST
+	help
+	  If you have a system using an Ingenic SoC and wish to make use of
+	  its UARTs, say Y to this option. If unsure, say N.
+
+config SERIAL_8250_LPSS
+	tristate "Support for serial ports on Intel LPSS platforms"
+	default SERIAL_8250
+	depends on SERIAL_8250 && PCI
+	depends on X86 || COMPILE_TEST
+	select SERIAL_8250_DWLIB
+	select DW_DMAC_CORE if SERIAL_8250_DMA
+	select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
+	select RATIONAL
+	help
+	  Selecting this option will enable handling of the UART found on
+	  various Intel platforms such as:
+	    - Intel Baytrail SoC
+	    - Intel Braswell SoC
+	    - Intel Quark X1000 SoC
+	  that are not covered by the more generic SERIAL_8250_PCI option.
+
+config SERIAL_8250_MID
+	tristate "Support for serial ports on Intel MID platforms"
+	default SERIAL_8250
+	depends on SERIAL_8250 && PCI
+	depends on X86 || COMPILE_TEST
+	select HSU_DMA if SERIAL_8250_DMA
+	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
+	select RATIONAL
+	help
+	  Selecting this option will enable handling of the UART found on
+	  Intel Medfield SOC and various other Intel platforms that is not
+	  covered by the more generic SERIAL_8250_PCI option.
+
+config SERIAL_8250_PERICOM
+	tristate "Support for Pericom and Acces I/O serial ports"
+	default SERIAL_8250
+	depends on SERIAL_8250 && PCI
+	help
+	  Selecting this option will enable handling of the Pericom and Acces
+	  I/O UARTs that are not covered by the more generic SERIAL_8250_PCI
+	  option.
+
+config SERIAL_8250_PXA
+	tristate "PXA serial port support"
+	depends on SERIAL_8250
+	depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST
+	help
+	  If you have a machine based on an Intel XScale PXA2xx CPU you can
+	  enable its onboard serial ports by enabling this option. The option is
+	  applicable to both devicetree and legacy boards, and early console is
+	  part of its support.
+
+config SERIAL_8250_TEGRA
+	tristate "8250 support for Tegra serial ports"
+	default SERIAL_8250
+	depends on SERIAL_8250
+	depends on ARCH_TEGRA || COMPILE_TEST
+	help
+	  Select this option if you have machine with an NVIDIA Tegra SoC and
+	  wish to enable 8250 serial driver for the Tegra serial interfaces.
+
+config SERIAL_8250_BCM7271
+	tristate "Broadcom 8250 based serial port"
+	depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST)
+	default ARCH_BRCMSTB
+	help
+	  If you have a Broadcom STB based board and want to use the
+	  enhanced features of the Broadcom 8250 based serial port,
+	  including DMA support and high accuracy BAUD rates, say
+	  Y to this option. If unsure, say N.
+
+config SERIAL_OF_PLATFORM
+	tristate "Devicetree based probing for 8250 ports"
+	depends on SERIAL_8250 && OF
+	help
+	  This option is used for all 8250 compatible serial ports that
+	  are probed through devicetree, including Open Firmware based
+	  PowerPC systems and embedded systems on architectures using the
+	  flattened device tree format.
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
new file mode 100644
index 000000000..628b75be3
--- /dev/null
+++ b/drivers/tty/serial/8250/Makefile
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the 8250 serial device drivers.
+#
+
+obj-$(CONFIG_SERIAL_8250)		+= 8250.o 8250_base.o
+8250-y					:= 8250_core.o
+8250-$(CONFIG_ALPHA_GENERIC)		+= 8250_alpha.o
+8250-$(CONFIG_ALPHA_JENSEN)		+= 8250_alpha.o
+8250-$(CONFIG_SERIAL_8250_PNP)		+= 8250_pnp.o
+8250_base-y				:= 8250_port.o
+8250_base-$(CONFIG_SERIAL_8250_DMA)	+= 8250_dma.o
+8250_base-$(CONFIG_SERIAL_8250_DWLIB)	+= 8250_dwlib.o
+8250_base-$(CONFIG_SERIAL_8250_FINTEK)	+= 8250_fintek.o
+8250_base-$(CONFIG_SERIAL_8250_PCILIB)	+= 8250_pcilib.o
+obj-$(CONFIG_SERIAL_8250_PARISC)	+= 8250_parisc.o
+obj-$(CONFIG_SERIAL_8250_PCI)		+= 8250_pci.o
+obj-$(CONFIG_SERIAL_8250_EXAR)		+= 8250_exar.o
+obj-$(CONFIG_SERIAL_8250_HP300)		+= 8250_hp300.o
+obj-$(CONFIG_SERIAL_8250_CS)		+= serial_cs.o
+obj-$(CONFIG_SERIAL_8250_ACORN)		+= 8250_acorn.o
+obj-$(CONFIG_SERIAL_8250_ASPEED_VUART)	+= 8250_aspeed_vuart.o
+obj-$(CONFIG_SERIAL_8250_BCM2835AUX)	+= 8250_bcm2835aux.o
+obj-$(CONFIG_SERIAL_8250_CONSOLE)	+= 8250_early.o
+obj-$(CONFIG_SERIAL_8250_FOURPORT)	+= 8250_fourport.o
+obj-$(CONFIG_SERIAL_8250_ACCENT)	+= 8250_accent.o
+obj-$(CONFIG_SERIAL_8250_BOCA)		+= 8250_boca.o
+obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554)	+= 8250_exar_st16c554.o
+obj-$(CONFIG_SERIAL_8250_HUB6)		+= 8250_hub6.o
+obj-$(CONFIG_SERIAL_8250_PCI1XXXX)	+= 8250_pci1xxxx.o
+obj-$(CONFIG_SERIAL_8250_FSL)		+= 8250_fsl.o
+obj-$(CONFIG_SERIAL_8250_MEN_MCB)	+= 8250_men_mcb.o
+obj-$(CONFIG_SERIAL_8250_DFL)		+= 8250_dfl.o
+obj-$(CONFIG_SERIAL_8250_DW)		+= 8250_dw.o
+obj-$(CONFIG_SERIAL_8250_EM)		+= 8250_em.o
+obj-$(CONFIG_SERIAL_8250_IOC3)		+= 8250_ioc3.o
+obj-$(CONFIG_SERIAL_8250_OMAP)		+= 8250_omap.o
+obj-$(CONFIG_SERIAL_8250_RT288X)	+= 8250_rt288x.o
+obj-$(CONFIG_SERIAL_8250_LPC18XX)	+= 8250_lpc18xx.o
+obj-$(CONFIG_SERIAL_8250_MT6577)	+= 8250_mtk.o
+obj-$(CONFIG_SERIAL_8250_UNIPHIER)	+= 8250_uniphier.o
+obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
+obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o
+obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
+obj-$(CONFIG_SERIAL_8250_PERICOM)	+= 8250_pericom.o
+obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
+obj-$(CONFIG_SERIAL_8250_TEGRA)		+= 8250_tegra.o
+obj-$(CONFIG_SERIAL_8250_BCM7271)	+= 8250_bcm7271.o
+obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
+
+CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt
diff --git a/drivers/tty/serial/8250/serial_cs.c b/drivers/tty/serial/8250/serial_cs.c
new file mode 100644
index 000000000..dc2ef05a1
--- /dev/null
+++ b/drivers/tty/serial/8250/serial_cs.c
@@ -0,0 +1,873 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
+/*======================================================================
+
+    A driver for PCMCIA serial devices
+
+    serial_cs.c 1.134 2002/05/04 05:48:53
+
+    The contents of this file are subject to the Mozilla Public
+    License Version 1.1 (the "License"); you may not use this file
+    except in compliance with the License. You may obtain a copy of
+    the License at http://www.mozilla.org/MPL/
+
+    Software distributed under the License is distributed on an "AS
+    IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+    implied. See the License for the specific language governing
+    rights and limitations under the License.
+
+    The initial developer of the original code is David A. Hinds
+    <dahinds@users.sourceforge.net>.  Portions created by David A. Hinds
+    are Copyright (C) 1999 David A. Hinds.  All Rights Reserved.
+
+    Alternatively, the contents of this file may be used under the
+    terms of the GNU General Public License version 2 (the "GPL"), in which
+    case the provisions of the GPL are applicable instead of the
+    above.  If you wish to allow the use of your version of this file
+    only under the terms of the GPL and not to allow others to use
+    your version of this file under the MPL, indicate your decision
+    by deleting the provisions above and replace them with the notice
+    and other provisions required by the GPL.  If you do not delete
+    the provisions above, a recipient may use your version of this
+    file under either the MPL or the GPL.
+
+======================================================================*/
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/serial_core.h>
+#include <linux/delay.h>
+#include <linux/major.h>
+#include <asm/io.h>
+
+#include <pcmcia/cistpl.h>
+#include <pcmcia/ciscode.h>
+#include <pcmcia/ds.h>
+#include <pcmcia/cisreg.h>
+
+#include "8250.h"
+
+
+/*====================================================================*/
+
+/* Parameters that can be set with 'insmod' */
+
+/* Enable the speaker? */
+static int do_sound = 1;
+/* Skip strict UART tests? */
+static int buggy_uart;
+
+module_param(do_sound, int, 0444);
+module_param(buggy_uart, int, 0444);
+
+/*====================================================================*/
+
+/* Table of multi-port card ID's */
+
+struct serial_quirk {
+	unsigned int manfid;
+	unsigned int prodid;
+	int multi;		/* 1 = multifunction, > 1 = # ports */
+	void (*config)(struct pcmcia_device *);
+	void (*setup)(struct pcmcia_device *, struct uart_8250_port *);
+	void (*wakeup)(struct pcmcia_device *);
+	int (*post)(struct pcmcia_device *);
+};
+
+struct serial_info {
+	struct pcmcia_device	*p_dev;
+	int			ndev;
+	int			multi;
+	int			slave;
+	int			manfid;
+	int			prodid;
+	int			c950ctrl;
+	int			line[4];
+	const struct serial_quirk *quirk;
+};
+
+struct serial_cfg_mem {
+	tuple_t tuple;
+	cisparse_t parse;
+	u_char buf[256];
+};
+
+/*
+ * vers_1 5.0, "Brain Boxes", "2-Port RS232 card", "r6"
+ * manfid 0x0160, 0x0104
+ * This card appears to have a 14.7456MHz clock.
+ */
+/* Generic Modem: MD55x (GPRS/EDGE) have
+ * Elan VPU16551 UART with 14.7456MHz oscillator
+ * manfid 0x015D, 0x4C45
+ */
+static void quirk_setup_brainboxes_0104(struct pcmcia_device *link, struct uart_8250_port *uart)
+{
+	uart->port.uartclk = 14745600;
+}
+
+static int quirk_post_ibm(struct pcmcia_device *link)
+{
+	u8 val;
+	int ret;
+
+	ret = pcmcia_read_config_byte(link, 0x800, &val);
+	if (ret)
+		goto failed;
+
+	ret = pcmcia_write_config_byte(link, 0x800, val | 1);
+	if (ret)
+		goto failed;
+	return 0;
+
+ failed:
+	return -ENODEV;
+}
+
+/*
+ * Nokia cards are not really multiport cards.  Shouldn't this
+ * be handled by setting the quirk entry .multi = 0 | 1 ?
+ */
+static void quirk_config_nokia(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+
+	if (info->multi > 1)
+		info->multi = 1;
+}
+
+static void quirk_wakeup_oxsemi(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+
+	if (info->c950ctrl)
+		outb(12, info->c950ctrl + 1);
+}
+
+/* request_region? oxsemi branch does no request_region too... */
+/*
+ * This sequence is needed to properly initialize MC45 attached to OXCF950.
+ * I tried decreasing these msleep()s, but it worked properly (survived
+ * 1000 stop/start operations) with these timeouts (or bigger).
+ */
+static void quirk_wakeup_possio_gcc(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	unsigned int ctrl = info->c950ctrl;
+
+	outb(0xA, ctrl + 1);
+	msleep(100);
+	outb(0xE, ctrl + 1);
+	msleep(300);
+	outb(0xC, ctrl + 1);
+	msleep(100);
+	outb(0xE, ctrl + 1);
+	msleep(200);
+	outb(0xF, ctrl + 1);
+	msleep(100);
+	outb(0xE, ctrl + 1);
+	msleep(100);
+	outb(0xC, ctrl + 1);
+}
+
+/*
+ * Socket Dual IO: this enables irq's for second port
+ */
+static void quirk_config_socket(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+
+	if (info->multi)
+		link->config_flags |= CONF_ENABLE_ESR;
+}
+
+static const struct serial_quirk quirks[] = {
+	{
+		.manfid	= 0x0160,
+		.prodid	= 0x0104,
+		.multi	= -1,
+		.setup	= quirk_setup_brainboxes_0104,
+	}, {
+		.manfid	= 0x015D,
+		.prodid	= 0x4C45,
+		.multi	= -1,
+		.setup	= quirk_setup_brainboxes_0104,
+	}, {
+		.manfid	= MANFID_IBM,
+		.prodid	= ~0,
+		.multi	= -1,
+		.post	= quirk_post_ibm,
+	}, {
+		.manfid	= MANFID_INTEL,
+		.prodid	= PRODID_INTEL_DUAL_RS232,
+		.multi	= 2,
+	}, {
+		.manfid	= MANFID_NATINST,
+		.prodid	= PRODID_NATINST_QUAD_RS232,
+		.multi	= 4,
+	}, {
+		.manfid	= MANFID_NOKIA,
+		.prodid	= ~0,
+		.multi	= -1,
+		.config	= quirk_config_nokia,
+	}, {
+		.manfid	= MANFID_OMEGA,
+		.prodid	= PRODID_OMEGA_QSP_100,
+		.multi	= 4,
+	}, {
+		.manfid	= MANFID_OXSEMI,
+		.prodid	= ~0,
+		.multi	= -1,
+		.wakeup	= quirk_wakeup_oxsemi,
+	}, {
+		.manfid	= MANFID_POSSIO,
+		.prodid	= PRODID_POSSIO_GCC,
+		.multi	= -1,
+		.wakeup	= quirk_wakeup_possio_gcc,
+	}, {
+		.manfid	= MANFID_QUATECH,
+		.prodid	= PRODID_QUATECH_DUAL_RS232,
+		.multi	= 2,
+	}, {
+		.manfid	= MANFID_QUATECH,
+		.prodid	= PRODID_QUATECH_DUAL_RS232_D1,
+		.multi	= 2,
+	}, {
+		.manfid	= MANFID_QUATECH,
+		.prodid	= PRODID_QUATECH_DUAL_RS232_G,
+		.multi	= 2,
+	}, {
+		.manfid	= MANFID_QUATECH,
+		.prodid	= PRODID_QUATECH_QUAD_RS232,
+		.multi	= 4,
+	}, {
+		.manfid	= MANFID_SOCKET,
+		.prodid	= PRODID_SOCKET_DUAL_RS232,
+		.multi	= 2,
+		.config	= quirk_config_socket,
+	}, {
+		.manfid	= MANFID_SOCKET,
+		.prodid	= ~0,
+		.multi	= -1,
+		.config	= quirk_config_socket,
+	}
+};
+
+
+static int serial_config(struct pcmcia_device *link);
+
+
+static void serial_remove(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	int i;
+
+	dev_dbg(&link->dev, "serial_release\n");
+
+	/*
+	 * Recheck to see if the device is still configured.
+	 */
+	for (i = 0; i < info->ndev; i++)
+		serial8250_unregister_port(info->line[i]);
+
+	if (!info->slave)
+		pcmcia_disable_device(link);
+}
+
+static int serial_suspend(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	int i;
+
+	for (i = 0; i < info->ndev; i++)
+		serial8250_suspend_port(info->line[i]);
+
+	return 0;
+}
+
+static int serial_resume(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	int i;
+
+	for (i = 0; i < info->ndev; i++)
+		serial8250_resume_port(info->line[i]);
+
+	if (info->quirk && info->quirk->wakeup)
+		info->quirk->wakeup(link);
+
+	return 0;
+}
+
+static int serial_probe(struct pcmcia_device *link)
+{
+	struct serial_info *info;
+	int ret;
+
+	dev_dbg(&link->dev, "serial_attach()\n");
+
+	/* Create new serial device */
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+	info->p_dev = link;
+	link->priv = info;
+
+	link->config_flags |= CONF_ENABLE_IRQ | CONF_AUTO_SET_IO;
+	if (do_sound)
+		link->config_flags |= CONF_ENABLE_SPKR;
+
+	ret = serial_config(link);
+	if (ret)
+		goto free_info;
+
+	return 0;
+
+free_info:
+	kfree(info);
+	return ret;
+}
+
+static void serial_detach(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+
+	dev_dbg(&link->dev, "serial_detach\n");
+
+	/*
+	 * Ensure that the ports have been released.
+	 */
+	serial_remove(link);
+
+	/* free bits */
+	kfree(info);
+}
+
+/*====================================================================*/
+
+static int setup_serial(struct pcmcia_device *handle, struct serial_info *info,
+			unsigned int iobase, int irq)
+{
+	struct uart_8250_port uart;
+	int line;
+
+	memset(&uart, 0, sizeof(uart));
+	uart.port.iobase = iobase;
+	uart.port.irq = irq;
+	uart.port.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ;
+	uart.port.uartclk = 1843200;
+	uart.port.dev = &handle->dev;
+	if (buggy_uart)
+		uart.port.flags |= UPF_BUGGY_UART;
+
+	if (info->quirk && info->quirk->setup)
+		info->quirk->setup(handle, &uart);
+
+	line = serial8250_register_8250_port(&uart);
+	if (line < 0) {
+		pr_err("serial_cs: serial8250_register_8250_port() at 0x%04lx, irq %d failed\n",
+							(unsigned long)iobase, irq);
+		return -EINVAL;
+	}
+
+	info->line[info->ndev] = line;
+	info->ndev++;
+
+	return 0;
+}
+
+/*====================================================================*/
+
+static int pfc_config(struct pcmcia_device *p_dev)
+{
+	unsigned int port = 0;
+	struct serial_info *info = p_dev->priv;
+
+	if ((p_dev->resource[1]->end != 0) &&
+		(resource_size(p_dev->resource[1]) == 8)) {
+		port = p_dev->resource[1]->start;
+		info->slave = 1;
+	} else if ((info->manfid == MANFID_OSITECH) &&
+		(resource_size(p_dev->resource[0]) == 0x40)) {
+		port = p_dev->resource[0]->start + 0x28;
+		info->slave = 1;
+	}
+	if (info->slave)
+		return setup_serial(p_dev, info, port, p_dev->irq);
+
+	dev_warn(&p_dev->dev, "no usable port range found, giving up\n");
+	return -ENODEV;
+}
+
+static int simple_config_check(struct pcmcia_device *p_dev, void *priv_data)
+{
+	static const int size_table[2] = { 8, 16 };
+	int *try = priv_data;
+
+	if (p_dev->resource[0]->start == 0)
+		return -ENODEV;
+
+	if ((*try & 0x1) == 0)
+		p_dev->io_lines = 16;
+
+	if (p_dev->resource[0]->end != size_table[(*try >> 1)])
+		return -ENODEV;
+
+	p_dev->resource[0]->end = 8;
+	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
+	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
+
+	return pcmcia_request_io(p_dev);
+}
+
+static int simple_config_check_notpicky(struct pcmcia_device *p_dev,
+					void *priv_data)
+{
+	static const unsigned int base[5] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, 0x0 };
+	int j;
+
+	if (p_dev->io_lines > 3)
+		return -ENODEV;
+
+	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
+	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
+	p_dev->resource[0]->end = 8;
+
+	for (j = 0; j < 5; j++) {
+		p_dev->resource[0]->start = base[j];
+		p_dev->io_lines = base[j] ? 16 : 3;
+		if (!pcmcia_request_io(p_dev))
+			return 0;
+	}
+	return -ENODEV;
+}
+
+static int simple_config(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	int ret, try;
+
+	/*
+	 * First pass: look for a config entry that looks normal.
+	 * Two tries: without IO aliases, then with aliases.
+	 */
+	link->config_flags |= CONF_AUTO_SET_VPP;
+	for (try = 0; try < 4; try++)
+		if (!pcmcia_loop_config(link, simple_config_check, &try))
+			goto found_port;
+
+	/*
+	 * Second pass: try to find an entry that isn't picky about
+	 * its base address, then try to grab any standard serial port
+	 * address, and finally try to get any free port.
+	 */
+	ret = pcmcia_loop_config(link, simple_config_check_notpicky, NULL);
+	if (ret) {
+		dev_warn(&link->dev, "no usable port range found, giving up\n");
+		return ret;
+	}
+
+found_port:
+	if (info->multi && (info->manfid == MANFID_3COM))
+		link->config_index &= ~(0x08);
+
+	/*
+	 * Apply any configuration quirks.
+	 */
+	if (info->quirk && info->quirk->config)
+		info->quirk->config(link);
+
+	ret = pcmcia_enable_device(link);
+	if (ret != 0)
+		return ret;
+	return setup_serial(link, info, link->resource[0]->start, link->irq);
+}
+
+static int multi_config_check(struct pcmcia_device *p_dev, void *priv_data)
+{
+	int *multi = priv_data;
+
+	if (p_dev->resource[1]->end)
+		return -EINVAL;
+
+	/*
+	 * The quad port cards have bad CIS's, so just look for a
+	 * window larger than 8 ports and assume it will be right.
+	 */
+	if (p_dev->resource[0]->end <= 8)
+		return -EINVAL;
+
+	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
+	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
+	p_dev->resource[0]->end = *multi * 8;
+
+	if (pcmcia_request_io(p_dev))
+		return -ENODEV;
+	return 0;
+}
+
+static int multi_config_check_notpicky(struct pcmcia_device *p_dev,
+				       void *priv_data)
+{
+	int *base2 = priv_data;
+
+	if (!p_dev->resource[0]->end || !p_dev->resource[1]->end ||
+		p_dev->resource[0]->start + 8 != p_dev->resource[1]->start)
+		return -ENODEV;
+
+	p_dev->resource[0]->end = p_dev->resource[1]->end = 8;
+	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
+	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
+
+	if (pcmcia_request_io(p_dev))
+		return -ENODEV;
+
+	*base2 = p_dev->resource[0]->start + 8;
+	return 0;
+}
+
+static int multi_config(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	int i, base2 = 0;
+
+	/* First, look for a generic full-sized window */
+	if (!pcmcia_loop_config(link, multi_config_check, &info->multi))
+		base2 = link->resource[0]->start + 8;
+	else {
+		/* If that didn't work, look for two windows */
+		info->multi = 2;
+		if (pcmcia_loop_config(link, multi_config_check_notpicky,
+				       &base2)) {
+			dev_warn(&link->dev,
+				 "no usable port range found, giving up\n");
+			return -ENODEV;
+		}
+	}
+
+	if (!link->irq)
+		dev_warn(&link->dev, "no usable IRQ found, continuing...\n");
+
+	/*
+	 * Apply any configuration quirks.
+	 */
+	if (info->quirk && info->quirk->config)
+		info->quirk->config(link);
+
+	i = pcmcia_enable_device(link);
+	if (i != 0)
+		return -ENODEV;
+
+	/* The Oxford Semiconductor OXCF950 cards are in fact single-port:
+	 * 8 registers are for the UART, the others are extra registers.
+	 * Siemen's MC45 PCMCIA (Possio's GCC) is OXCF950 based too.
+	 */
+	if (info->manfid == MANFID_OXSEMI || (info->manfid == MANFID_POSSIO &&
+				info->prodid == PRODID_POSSIO_GCC)) {
+		if (link->config_index == 1 ||
+		    link->config_index == 3) {
+			setup_serial(link, info, base2, link->irq);
+			base2 = link->resource[0]->start;
+		} else {
+			setup_serial(link, info, link->resource[0]->start,
+				     link->irq);
+		}
+		info->c950ctrl = base2;
+
+		/*
+		 * FIXME: We really should wake up the port prior to
+		 * handing it over to the serial layer.
+		 */
+		if (info->quirk && info->quirk->wakeup)
+			info->quirk->wakeup(link);
+
+		return 0;
+	}
+
+	setup_serial(link, info, link->resource[0]->start, link->irq);
+	for (i = 0; i < info->multi - 1; i++)
+		setup_serial(link, info, base2 + (8 * i),
+				link->irq);
+	return 0;
+}
+
+static int serial_check_for_multi(struct pcmcia_device *p_dev,  void *priv_data)
+{
+	struct serial_info *info = p_dev->priv;
+
+	if (!p_dev->resource[0]->end)
+		return -EINVAL;
+
+	if ((!p_dev->resource[1]->end) && (p_dev->resource[0]->end % 8 == 0))
+		info->multi = p_dev->resource[0]->end >> 3;
+
+	if ((p_dev->resource[1]->end) && (p_dev->resource[0]->end == 8)
+		&& (p_dev->resource[1]->end == 8))
+		info->multi = 2;
+
+	return 0; /* break */
+}
+
+
+static int serial_config(struct pcmcia_device *link)
+{
+	struct serial_info *info = link->priv;
+	int i;
+
+	dev_dbg(&link->dev, "serial_config\n");
+
+	/* Is this a compliant multifunction card? */
+	info->multi = (link->socket->functions > 1);
+
+	/* Is this a multiport card? */
+	info->manfid = link->manf_id;
+	info->prodid = link->card_id;
+
+	for (i = 0; i < ARRAY_SIZE(quirks); i++)
+		if ((quirks[i].manfid == ~0 ||
+		     quirks[i].manfid == info->manfid) &&
+		    (quirks[i].prodid == ~0 ||
+		     quirks[i].prodid == info->prodid)) {
+			info->quirk = &quirks[i];
+			break;
+		}
+
+	/*
+	 * Another check for dual-serial cards: look for either serial or
+	 * multifunction cards that ask for appropriate IO port ranges.
+	 */
+	if ((info->multi == 0) &&
+	    (link->has_func_id) &&
+	    (link->socket->pcmcia_pfc == 0) &&
+	    ((link->func_id == CISTPL_FUNCID_MULTI) ||
+	     (link->func_id == CISTPL_FUNCID_SERIAL))) {
+		if (pcmcia_loop_config(link, serial_check_for_multi, info))
+			goto failed;
+	}
+
+	/*
+	 * Apply any multi-port quirk.
+	 */
+	if (info->quirk && info->quirk->multi != -1)
+		info->multi = info->quirk->multi;
+
+	dev_info(&link->dev,
+		"trying to set up [0x%04x:0x%04x] (pfc: %d, multi: %d, quirk: %p)\n",
+		link->manf_id, link->card_id,
+		link->socket->pcmcia_pfc, info->multi, info->quirk);
+	if (link->socket->pcmcia_pfc)
+		i = pfc_config(link);
+	else if (info->multi > 1)
+		i = multi_config(link);
+	else
+		i = simple_config(link);
+
+	if (i || info->ndev == 0)
+		goto failed;
+
+	/*
+	 * Apply any post-init quirk.  FIXME: This should really happen
+	 * before we register the port, since it might already be in use.
+	 */
+	if (info->quirk && info->quirk->post)
+		if (info->quirk->post(link))
+			goto failed;
+
+	return 0;
+
+failed:
+	dev_warn(&link->dev, "failed to initialize\n");
+	serial_remove(link);
+	return -ENODEV;
+}
+
+static const struct pcmcia_device_id serial_ids[] = {
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0057, 0x0021),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0089, 0x110a),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0104, 0x000a),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0105, 0x0d0a),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0105, 0x0e0a),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0105, 0xea15),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0109, 0x0501),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0138, 0x110a),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0140, 0x000a),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0143, 0x3341),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0143, 0xc0ab),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x016c, 0x0081),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x021b, 0x0101),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x08a1, 0xc0ab),
+	PCMCIA_PFC_DEVICE_PROD_ID123(1, "MEGAHERTZ", "CC/XJEM3288", "DATA/FAX/CELL ETHERNET MODEM", 0xf510db04, 0x04cd2988, 0x46a52d63),
+	PCMCIA_PFC_DEVICE_PROD_ID123(1, "MEGAHERTZ", "CC/XJEM3336", "DATA/FAX/CELL ETHERNET MODEM", 0xf510db04, 0x0143b773, 0x46a52d63),
+	PCMCIA_PFC_DEVICE_PROD_ID123(1, "MEGAHERTZ", "EM1144T", "PCMCIA MODEM", 0xf510db04, 0x856d66c8, 0xbd6c43ef),
+	PCMCIA_PFC_DEVICE_PROD_ID123(1, "MEGAHERTZ", "XJEM1144/CCEM1144", "PCMCIA MODEM", 0xf510db04, 0x52d21e1e, 0xbd6c43ef),
+	PCMCIA_PFC_DEVICE_PROD_ID13(1, "Xircom", "CEM28", 0x2e3ee845, 0x0ea978ea),
+	PCMCIA_PFC_DEVICE_PROD_ID13(1, "Xircom", "CEM33", 0x2e3ee845, 0x80609023),
+	PCMCIA_PFC_DEVICE_PROD_ID13(1, "Xircom", "CEM56", 0x2e3ee845, 0xa650c32a),
+	PCMCIA_PFC_DEVICE_PROD_ID13(1, "Xircom", "REM10", 0x2e3ee845, 0x76df1d29),
+	PCMCIA_PFC_DEVICE_PROD_ID13(1, "Xircom", "XEM5600", 0x2e3ee845, 0xf1403719),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "AnyCom", "Fast Ethernet + 56K COMBO", 0x578ba6e7, 0xb0ac62c4),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "ATKK", "LM33-PCM-T", 0xba9eb7e2, 0x077c174e),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "D-Link", "DME336T", 0x1a424a1c, 0xb23897ff),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "Gateway 2000", "XJEM3336", 0xdd9989be, 0x662c394c),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "Grey Cell", "GCS3000", 0x2a151fac, 0x48b932ae),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "Linksys", "EtherFast 10&100 + 56K PC Card (PCMLM56)", 0x0733cc81, 0xb3765033),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "LINKSYS", "PCMLM336", 0xf7cb0b07, 0x7a821b58),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "MEGAHERTZ", "XJEM1144/CCEM1144", 0xf510db04, 0x52d21e1e),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "MICRO RESEARCH", "COMBO-L/M-336", 0xb2ced065, 0x3ced0555),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "NEC", "PK-UG-J001", 0x18df0ba0, 0x831b1064),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "Ositech", "Trumpcard:Jack of Diamonds Modem+Ethernet", 0xc2f80cd, 0x656947b9),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "Ositech", "Trumpcard:Jack of Hearts Modem+Ethernet", 0xc2f80cd, 0xdc9ba5ed),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "PCMCIAs", "ComboCard", 0xdcfe12d3, 0xcd8906cc),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "PCMCIAs", "LanModem", 0xdcfe12d3, 0xc67c648f),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "TDK", "GlobalNetworker 3410/3412", 0x1eae9475, 0xd9a93bed),
+	PCMCIA_PFC_DEVICE_PROD_ID12(1, "Xircom", "CreditCard Ethernet+Modem II", 0x2e3ee845, 0xeca401bf),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0032, 0x0e01),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0032, 0x0a05),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0032, 0x0b05),
+	PCMCIA_PFC_DEVICE_MANF_CARD(1, 0x0032, 0x1101),
+	PCMCIA_MFC_DEVICE_MANF_CARD(0, 0x0104, 0x0070),
+	PCMCIA_MFC_DEVICE_MANF_CARD(1, 0x0101, 0x0562),
+	PCMCIA_MFC_DEVICE_MANF_CARD(1, 0x0104, 0x0070),
+	PCMCIA_MFC_DEVICE_MANF_CARD(1, 0x016c, 0x0020),
+	PCMCIA_MFC_DEVICE_PROD_ID123(1, "APEX DATA", "MULTICARD", "ETHERNET-MODEM", 0x11c2da09, 0x7289dc5d, 0xaad95e1f),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "IBM", "Home and Away 28.8 PC Card       ", 0xb569a6e5, 0x5bd4ff2c),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "IBM", "Home and Away Credit Card Adapter", 0xb569a6e5, 0x4bdf15c3),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "IBM", "w95 Home and Away Credit Card ", 0xb569a6e5, 0xae911c15),
+	PCMCIA_MFC_DEVICE_PROD_ID1(1, "Motorola MARQUIS", 0xf03e4e77),
+	PCMCIA_MFC_DEVICE_PROD_ID2(1, "FAX/Modem/Ethernet Combo Card ", 0x1ed59302),
+	PCMCIA_DEVICE_MANF_CARD(0x0089, 0x0301),
+	PCMCIA_DEVICE_MANF_CARD(0x00a4, 0x0276),
+	PCMCIA_DEVICE_MANF_CARD(0x0101, 0x0039),
+	PCMCIA_DEVICE_MANF_CARD(0x0104, 0x0006),
+	PCMCIA_DEVICE_MANF_CARD(0x0105, 0x0101), /* TDK DF2814 */
+	PCMCIA_DEVICE_MANF_CARD(0x0105, 0x100a), /* Xircom CM-56G */
+	PCMCIA_DEVICE_MANF_CARD(0x0105, 0x3e0a), /* TDK DF5660 */
+	PCMCIA_DEVICE_MANF_CARD(0x0105, 0x410a),
+	PCMCIA_DEVICE_MANF_CARD(0x0107, 0x0002), /* USRobotics 14,400 */
+	PCMCIA_DEVICE_MANF_CARD(0x010b, 0x0d50),
+	PCMCIA_DEVICE_MANF_CARD(0x010b, 0x0d51),
+	PCMCIA_DEVICE_MANF_CARD(0x010b, 0x0d52),
+	PCMCIA_DEVICE_MANF_CARD(0x010b, 0x0d53),
+	PCMCIA_DEVICE_MANF_CARD(0x010b, 0xd180),
+	PCMCIA_DEVICE_MANF_CARD(0x0115, 0x3330), /* USRobotics/SUN 14,400 */
+	PCMCIA_DEVICE_MANF_CARD(0x0124, 0x0100), /* Nokia DTP-2 ver II */
+	PCMCIA_DEVICE_MANF_CARD(0x0134, 0x5600), /* LASAT COMMUNICATIONS A/S */
+	PCMCIA_DEVICE_MANF_CARD(0x0137, 0x000e),
+	PCMCIA_DEVICE_MANF_CARD(0x0137, 0x001b),
+	PCMCIA_DEVICE_MANF_CARD(0x0137, 0x0025),
+	PCMCIA_DEVICE_MANF_CARD(0x0137, 0x0045),
+	PCMCIA_DEVICE_MANF_CARD(0x0137, 0x0052),
+	PCMCIA_DEVICE_MANF_CARD(0x016c, 0x0006), /* Psion 56K+Fax */
+	PCMCIA_DEVICE_MANF_CARD(0x0200, 0x0001), /* MultiMobile */
+	PCMCIA_DEVICE_PROD_ID134("ADV", "TECH", "COMpad-32/85", 0x67459937, 0x916d02ba, 0x8fbe92ae),
+	PCMCIA_DEVICE_PROD_ID124("GATEWAY2000", "CC3144", "PCMCIA MODEM", 0x506bccae, 0xcb3685f1, 0xbd6c43ef),
+	PCMCIA_DEVICE_PROD_ID14("MEGAHERTZ", "PCMCIA MODEM", 0xf510db04, 0xbd6c43ef),
+	PCMCIA_DEVICE_PROD_ID124("TOSHIBA", "T144PF", "PCMCIA MODEM", 0xb4585a1a, 0x7271409c, 0xbd6c43ef),
+	PCMCIA_DEVICE_PROD_ID123("FUJITSU", "FC14F ", "MBH10213", 0x6ee5a3d8, 0x30ead12b, 0xb00f05a0),
+	PCMCIA_DEVICE_PROD_ID123("Novatel Wireless", "Merlin UMTS Modem", "U630", 0x32607776, 0xd9e73b13, 0xe87332e),
+	PCMCIA_DEVICE_PROD_ID13("MEGAHERTZ", "V.34 PCMCIA MODEM", 0xf510db04, 0xbb2cce4a),
+	PCMCIA_DEVICE_PROD_ID12("Brain Boxes", "Bluetooth PC Card", 0xee138382, 0xd4ce9b02),
+	PCMCIA_DEVICE_PROD_ID12("CIRRUS LOGIC", "FAX MODEM", 0xe625f451, 0xcecd6dfa),
+	PCMCIA_DEVICE_PROD_ID12("COMPAQ", "PCMCIA 28800 FAX/DATA MODEM", 0xa3a3062c, 0x8cbd7c76),
+	PCMCIA_DEVICE_PROD_ID12("COMPAQ", "PCMCIA 33600 FAX/DATA MODEM", 0xa3a3062c, 0x5a00ce95),
+	PCMCIA_DEVICE_PROD_ID12("Computerboards, Inc.", "PCM-COM422", 0xd0b78f51, 0x7e2d49ed),
+	PCMCIA_DEVICE_PROD_ID12("Dr. Neuhaus", "FURY CARD 14K4", 0x76942813, 0x8b96ce65),
+	PCMCIA_DEVICE_PROD_ID12("IBM", "ISDN/56K/GSM", 0xb569a6e5, 0xfee5297b),
+	PCMCIA_DEVICE_PROD_ID12("Intelligent", "ANGIA FAX/MODEM", 0xb496e65e, 0xf31602a6),
+	PCMCIA_DEVICE_PROD_ID12("Intel", "MODEM 2400+", 0x816cc815, 0x412729fb),
+	PCMCIA_DEVICE_PROD_ID12("Intertex", "IX34-PCMCIA", 0xf8a097e3, 0x97880447),
+	PCMCIA_DEVICE_PROD_ID12("IOTech Inc ", "PCMCIA Dual RS-232 Serial Port Card", 0x3bd2d898, 0x92abc92f),
+	PCMCIA_DEVICE_PROD_ID12("MACRONIX", "FAX/MODEM", 0x668388b3, 0x3f9bdf2f),
+	PCMCIA_DEVICE_PROD_ID12("Multi-Tech", "MT1432LT", 0x5f73be51, 0x0b3e2383),
+	PCMCIA_DEVICE_PROD_ID12("Multi-Tech", "MT2834LT", 0x5f73be51, 0x4cd7c09e),
+	PCMCIA_DEVICE_PROD_ID12("OEM      ", "C288MX     ", 0xb572d360, 0xd2385b7a),
+	PCMCIA_DEVICE_PROD_ID12("Option International", "V34bis GSM/PSTN Data/Fax Modem", 0x9d7cd6f5, 0x5cb8bf41),
+	PCMCIA_DEVICE_PROD_ID12("Option International", "GSM-Ready 56K/ISDN", 0x9d7cd6f5, 0xb23844aa),
+	PCMCIA_DEVICE_PROD_ID12("PCMCIA   ", "C336MX     ", 0x99bcafe9, 0xaa25bcab),
+	PCMCIA_DEVICE_PROD_ID12("Quatech Inc", "PCMCIA Dual RS-232 Serial Port Card", 0xc4420b35, 0x92abc92f),
+	PCMCIA_DEVICE_PROD_ID12("Quatech Inc", "Dual RS-232 Serial Port PC Card", 0xc4420b35, 0x031a380d),
+	PCMCIA_DEVICE_PROD_ID12("Telia", "SurfinBird 560P/A+", 0xe2cdd5e, 0xc9314b38),
+	PCMCIA_DEVICE_PROD_ID1("Smart Serial Port", 0x2d8ce292),
+	PCMCIA_PFC_DEVICE_CIS_PROD_ID12(1, "PCMCIA", "EN2218-LAN/MODEM", 0x281f1c5d, 0x570f348e, "cis/PCMLM28.cis"),
+	PCMCIA_PFC_DEVICE_CIS_PROD_ID12(1, "PCMCIA", "UE2218-LAN/MODEM", 0x281f1c5d, 0x6fdcacee, "cis/PCMLM28.cis"),
+	PCMCIA_PFC_DEVICE_CIS_PROD_ID12(1, "Psion Dacom", "Gold Card V34 Ethernet", 0xf5f025c2, 0x338e8155, "cis/PCMLM28.cis"),
+	PCMCIA_PFC_DEVICE_CIS_PROD_ID12(1, "Psion Dacom", "Gold Card V34 Ethernet GSM", 0xf5f025c2, 0x4ae85d35, "cis/PCMLM28.cis"),
+	PCMCIA_PFC_DEVICE_CIS_PROD_ID12(1, "LINKSYS", "PCMLM28", 0xf7cb0b07, 0x66881874, "cis/PCMLM28.cis"),
+	PCMCIA_PFC_DEVICE_CIS_PROD_ID12(1, "TOSHIBA", "Modem/LAN Card", 0xb4585a1a, 0x53f922f8, "cis/PCMLM28.cis"),
+	PCMCIA_MFC_DEVICE_CIS_PROD_ID12(1, "DAYNA COMMUNICATIONS", "LAN AND MODEM MULTIFUNCTION", 0x8fdf8f89, 0xdd5ed9e8, "cis/DP83903.cis"),
+	PCMCIA_MFC_DEVICE_CIS_PROD_ID4(1, "NSC MF LAN/Modem", 0x58fc6056, "cis/DP83903.cis"),
+	PCMCIA_MFC_DEVICE_CIS_MANF_CARD(1, 0x0101, 0x0556, "cis/3CCFEM556.cis"),
+	PCMCIA_MFC_DEVICE_CIS_MANF_CARD(1, 0x0175, 0x0000, "cis/DP83903.cis"),
+	PCMCIA_MFC_DEVICE_CIS_MANF_CARD(1, 0x0101, 0x0035, "cis/3CXEM556.cis"),
+	PCMCIA_MFC_DEVICE_CIS_MANF_CARD(1, 0x0101, 0x003d, "cis/3CXEM556.cis"),
+	PCMCIA_DEVICE_CIS_PROD_ID12("Sierra Wireless", "AC850", 0xd85f6206, 0x42a2c018, "cis/SW_8xx_SER.cis"), /* Sierra Wireless AC850 3G Network Adapter R1 */
+	PCMCIA_DEVICE_CIS_PROD_ID12("Sierra Wireless", "AC860", 0xd85f6206, 0x698f93db, "cis/SW_8xx_SER.cis"), /* Sierra Wireless AC860 3G Network Adapter R1 */
+	PCMCIA_DEVICE_CIS_PROD_ID12("Sierra Wireless", "AC710/AC750", 0xd85f6206, 0x761b11e0, "cis/SW_7xx_SER.cis"),  /* Sierra Wireless AC710/AC750 GPRS Network Adapter R1 */
+	PCMCIA_DEVICE_CIS_MANF_CARD(0x0192, 0xa555, "cis/SW_555_SER.cis"),  /* Sierra Aircard 555 CDMA 1xrtt Modem -- pre update */
+	PCMCIA_DEVICE_CIS_MANF_CARD(0x013f, 0xa555, "cis/SW_555_SER.cis"),  /* Sierra Aircard 555 CDMA 1xrtt Modem -- post update */
+	PCMCIA_DEVICE_CIS_PROD_ID12("MultiTech", "PCMCIA 56K DataFax", 0x842047ee, 0xc2efcf03, "cis/MT5634ZLX.cis"),
+	PCMCIA_DEVICE_CIS_PROD_ID12("ADVANTECH", "COMpad-32/85B-2", 0x96913a85, 0x27ab5437, "cis/COMpad2.cis"),
+	PCMCIA_DEVICE_CIS_PROD_ID12("ADVANTECH", "COMpad-32/85B-4", 0x96913a85, 0xcec8f102, "cis/COMpad4.cis"),
+	PCMCIA_DEVICE_CIS_PROD_ID123("ADVANTECH", "COMpad-32/85", "1.0", 0x96913a85, 0x8fbe92ae, 0x0877b627, "cis/COMpad2.cis"),
+	PCMCIA_DEVICE_CIS_PROD_ID2("RS-COM 2P", 0xad20b156, "cis/RS-COM-2P.cis"),
+	PCMCIA_DEVICE_PROD_ID12("ELAN DIGITAL SYSTEMS LTD, c1997.", "SERIAL CARD: SL100  1.00.", 0x19ca78af, 0xf964f42b),
+	PCMCIA_DEVICE_PROD_ID12("ELAN DIGITAL SYSTEMS LTD, c1997.", "SERIAL CARD: SL100", 0x19ca78af, 0x71d98e83),
+	PCMCIA_DEVICE_PROD_ID12("ELAN DIGITAL SYSTEMS LTD, c1997.", "SERIAL CARD: SL232  1.00.", 0x19ca78af, 0x69fb7490),
+	PCMCIA_DEVICE_PROD_ID12("ELAN DIGITAL SYSTEMS LTD, c1997.", "SERIAL CARD: SL232", 0x19ca78af, 0xb6bc0235),
+	PCMCIA_DEVICE_PROD_ID12("ELAN DIGITAL SYSTEMS LTD, c2000.", "SERIAL CARD: CF232", 0x63f2e0bd, 0xb9e175d3),
+	PCMCIA_DEVICE_PROD_ID12("ELAN DIGITAL SYSTEMS LTD, c2000.", "SERIAL CARD: CF232-5", 0x63f2e0bd, 0xfce33442),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: CF232", 0x3beb8cf2, 0x171e7190),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: CF232-5", 0x3beb8cf2, 0x20da4262),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: CF428", 0x3beb8cf2, 0xea5dd57d),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: CF500", 0x3beb8cf2, 0xd77255fa),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: IC232", 0x3beb8cf2, 0x6a709903),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: SL232", 0x3beb8cf2, 0x18430676),
+	PCMCIA_DEVICE_PROD_ID12("Elan", "Serial Port: XL232", 0x3beb8cf2, 0x6f933767),
+	PCMCIA_MFC_DEVICE_PROD_ID12(0, "Elan", "Serial Port: CF332", 0x3beb8cf2, 0x16dc1ba7),
+	PCMCIA_MFC_DEVICE_PROD_ID12(0, "Elan", "Serial Port: SL332", 0x3beb8cf2, 0x19816c41),
+	PCMCIA_MFC_DEVICE_PROD_ID12(0, "Elan", "Serial Port: SL385", 0x3beb8cf2, 0x64112029),
+	PCMCIA_MFC_DEVICE_PROD_ID12(0, "Elan", "Serial Port: SL432", 0x3beb8cf2, 0x1cce7ac4),
+	PCMCIA_MFC_DEVICE_PROD_ID12(0, "Elan", "Serial+Parallel Port: SP230", 0x3beb8cf2, 0xdb9e58bc),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "Elan", "Serial Port: CF332", 0x3beb8cf2, 0x16dc1ba7),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "Elan", "Serial Port: SL332", 0x3beb8cf2, 0x19816c41),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "Elan", "Serial Port: SL385", 0x3beb8cf2, 0x64112029),
+	PCMCIA_MFC_DEVICE_PROD_ID12(1, "Elan", "Serial Port: SL432", 0x3beb8cf2, 0x1cce7ac4),
+	PCMCIA_MFC_DEVICE_PROD_ID12(2, "Elan", "Serial Port: SL432", 0x3beb8cf2, 0x1cce7ac4),
+	PCMCIA_MFC_DEVICE_PROD_ID12(3, "Elan", "Serial Port: SL432", 0x3beb8cf2, 0x1cce7ac4),
+	PCMCIA_DEVICE_MANF_CARD(0x0279, 0x950b),
+	/* too generic */
+	/* PCMCIA_MFC_DEVICE_MANF_CARD(0, 0x0160, 0x0002), */
+	/* PCMCIA_MFC_DEVICE_MANF_CARD(1, 0x0160, 0x0002), */
+	PCMCIA_DEVICE_FUNC_ID(2),
+	PCMCIA_DEVICE_NULL,
+};
+MODULE_DEVICE_TABLE(pcmcia, serial_ids);
+
+MODULE_FIRMWARE("cis/PCMLM28.cis");
+MODULE_FIRMWARE("cis/DP83903.cis");
+MODULE_FIRMWARE("cis/3CCFEM556.cis");
+MODULE_FIRMWARE("cis/3CXEM556.cis");
+MODULE_FIRMWARE("cis/SW_8xx_SER.cis");
+MODULE_FIRMWARE("cis/SW_7xx_SER.cis");
+MODULE_FIRMWARE("cis/SW_555_SER.cis");
+MODULE_FIRMWARE("cis/MT5634ZLX.cis");
+MODULE_FIRMWARE("cis/COMpad2.cis");
+MODULE_FIRMWARE("cis/COMpad4.cis");
+MODULE_FIRMWARE("cis/RS-COM-2P.cis");
+
+static struct pcmcia_driver serial_cs_driver = {
+	.owner		= THIS_MODULE,
+	.name		= "serial_cs",
+	.probe		= serial_probe,
+	.remove		= serial_detach,
+	.id_table	= serial_ids,
+	.suspend	= serial_suspend,
+	.resume		= serial_resume,
+};
+module_pcmcia_driver(serial_cs_driver);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
new file mode 100644
index 000000000..bdc568a4a
--- /dev/null
+++ b/drivers/tty/serial/Kconfig
@@ -0,0 +1,1584 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Serial device configuration
+#
+
+menu "Serial drivers"
+	depends on HAS_IOMEM
+
+config SERIAL_EARLYCON
+	bool
+	depends on SERIAL_CORE
+	help
+	  Support for early consoles with the earlycon parameter. This enables
+	  the console before standard serial driver is probed. The console is
+	  enabled when early_param is processed.
+
+source "drivers/tty/serial/8250/Kconfig"
+
+comment "Non-8250 serial port support"
+
+config SERIAL_AMBA_PL010
+	tristate "ARM AMBA PL010 serial port support"
+	depends on ARM_AMBA || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This selects the ARM(R) AMBA(R) PrimeCell PL010 UART.  If you have
+	  an Integrator/AP or Integrator/PP2 platform, or if you have a
+	  Cirrus Logic EP93xx CPU, say Y or M here.
+
+	  If unsure, say N.
+
+config SERIAL_AMBA_PL010_CONSOLE
+	bool "Support for console on AMBA serial port"
+	depends on SERIAL_AMBA_PL010=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Say Y here if you wish to use an AMBA PrimeCell UART as the system
+	  console (the system console is the device which receives all kernel
+	  messages and warnings and which allows logins in single user mode).
+
+	  Even if you say Y here, the currently visible framebuffer console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyAM0". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
+config SERIAL_AMBA_PL011
+	tristate "ARM AMBA PL011 serial port support"
+	depends on ARM_AMBA
+	select SERIAL_CORE
+	help
+	  This selects the ARM(R) AMBA(R) PrimeCell PL011 UART.  If you have
+	  an Integrator/PP2, Integrator/CP or Versatile platform, say Y or M
+	  here.
+
+	  If unsure, say N.
+
+config SERIAL_AMBA_PL011_CONSOLE
+	bool "Support for console on AMBA serial port"
+	depends on SERIAL_AMBA_PL011=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Say Y here if you wish to use an AMBA PrimeCell UART as the system
+	  console (the system console is the device which receives all kernel
+	  messages and warnings and which allows logins in single user mode).
+
+	  Even if you say Y here, the currently visible framebuffer console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyAMA0". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
+config SERIAL_EARLYCON_SEMIHOST
+	bool "Early console using Arm compatible semihosting"
+	depends on ARM64 || ARM || RISCV
+	select SERIAL_CORE
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Support for early debug console using Arm compatible semihosting.
+	  This enables the console before standard serial driver is probed.
+	  This is enabled with "earlycon=smh" on the kernel command line.
+	  The console is enabled when early_param is processed.
+
+config SERIAL_EARLYCON_RISCV_SBI
+	bool "Early console using RISC-V SBI"
+	depends on RISCV_SBI_V01
+	select SERIAL_CORE
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Support for early debug console using RISC-V SBI. This enables
+	  the console before standard serial driver is probed. This is enabled
+	  with "earlycon=sbi" on the kernel command line. The console is
+	  enabled when early_param is processed.
+
+config SERIAL_SB1250_DUART
+	tristate "BCM1xxx on-chip DUART serial support"
+	depends on SIBYTE_SB1xxx_SOC=y
+	select SERIAL_CORE
+	default y
+	help
+	  Support for the asynchronous serial interface (DUART) included in
+	  the BCM1250 and derived System-On-a-Chip (SOC) devices.  Note that
+	  the letter D in DUART stands for "dual", which is how the device
+	  is implemented.  Depending on the SOC configuration there may be
+	  one or more DUARTs available of which all are handled.
+
+	  If unsure, say Y.  To compile this driver as a module, choose M here:
+	  the module will be called sb1250-duart.
+
+config SERIAL_SB1250_DUART_CONSOLE
+	bool "Support for console on a BCM1xxx DUART serial port"
+	depends on SERIAL_SB1250_DUART=y
+	select SERIAL_CORE_CONSOLE
+	default y
+	help
+	  If you say Y here, it will be possible to use a serial port as the
+	  system console (the system console is the device which receives all
+	  kernel messages and warnings and which allows logins in single user
+	  mode).
+
+	  If unsure, say Y.
+
+config SERIAL_ATMEL
+	bool "AT91 on-chip serial port support"
+	depends on COMMON_CLK
+	depends on ARCH_AT91 || COMPILE_TEST
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	select MFD_AT91_USART
+	help
+	  This enables the driver for the on-chip UARTs of the Atmel
+	  AT91 processors.
+
+config SERIAL_ATMEL_CONSOLE
+	bool "Support for console on AT91 serial port"
+	depends on SERIAL_ATMEL=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Say Y here if you wish to use an on-chip UART on a Atmel
+	  AT91 processor as the system console (the system
+	  console is the device which receives all kernel messages and
+	  warnings and which allows logins in single user mode).
+
+config SERIAL_ATMEL_PDC
+	bool "Support DMA transfers on AT91 serial port"
+	depends on SERIAL_ATMEL
+	default y
+	help
+	  Say Y here if you wish to use the PDC to do DMA transfers to
+	  and from the Atmel AT91 serial port. In order to
+	  actually use DMA transfers, make sure that the use_dma_tx
+	  and use_dma_rx members in the atmel_uart_data struct is set
+	  appropriately for each port.
+
+	  Note that break and error handling currently doesn't work
+	  properly when DMA is enabled. Make sure that ports where
+	  this matters don't use DMA.
+
+config SERIAL_ATMEL_TTYAT
+	bool "Install as device ttyATn instead of ttySn"
+	depends on SERIAL_ATMEL=y
+	help
+	  Say Y here if you wish to have the internal AT91 UARTs
+	  appear as /dev/ttyATn (major 204, minor starting at 154)
+	  instead of the normal /dev/ttySn (major 4, minor starting at
+	  64). This is necessary if you also want other UARTs, such as
+	  external 8250/16C550 compatible UARTs.
+	  The ttySn nodes are legally reserved for the 8250 serial driver
+	  but are often misused by other serial drivers.
+
+	  To use this, you should create suitable ttyATn device nodes in
+	  /dev/, and pass "console=ttyATn" to the kernel.
+
+	  Say Y if you have an external 8250/16C550 UART.  If unsure, say N.
+
+config SERIAL_KGDB_NMI
+	bool "Serial console over KGDB NMI debugger port"
+	depends on KGDB_SERIAL_CONSOLE
+	help
+	  This special driver allows you to temporary use NMI debugger port
+	  as a normal console (assuming that the port is attached to KGDB).
+
+	  Unlike KDB's disable_nmi command, with this driver you are always
+	  able to go back to the debugger using KGDB escape sequence ($3#33).
+	  This is because this console driver processes the input in NMI
+	  context, and thus is able to intercept the magic sequence.
+
+	  Note that since the console interprets input and uses polling
+	  communication methods, for things like PPP you still must fully
+	  detach debugger port from the KGDB NMI (i.e. disable_nmi), and
+	  use raw console.
+
+	  If unsure, say N.
+
+config SERIAL_MESON
+	tristate "Meson serial port support"
+	depends on ARCH_MESON || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This enables the driver for the on-chip UARTs of the Amlogic
+	  MesonX processors.
+
+config SERIAL_MESON_CONSOLE
+	bool "Support for console on meson"
+	depends on SERIAL_MESON
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Say Y here if you wish to use a Amlogic MesonX UART as the
+	  system console (the system console is the device which
+	  receives all kernel messages and warnings and which allows
+	  logins in single user mode) as /dev/ttyAMLx.
+
+config SERIAL_CLPS711X
+	tristate "CLPS711X serial port support"
+	depends on ARCH_CLPS711X || COMPILE_TEST
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  This enables the driver for the on-chip UARTs of the Cirrus
+	  Logic EP711x/EP721x/EP731x processors.
+
+config SERIAL_CLPS711X_CONSOLE
+	bool "Support for console on CLPS711X serial port"
+	depends on SERIAL_CLPS711X=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyCL1".
+
+config SERIAL_SAMSUNG
+	tristate "Samsung SoC serial support"
+	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_APPLE || ARCH_ARTPEC || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  Support for the on-chip UARTs on the Samsung
+	  S3C64xx/S5Pv210/Exynos and Apple M1 SoCs, providing
+	  /dev/ttySAC0, 1 and 2 (note, some machines may not provide all of
+	  these ports, depending on how the serial port pins are configured.
+
+	  Choose Y/M here only if you build for such SoC.
+
+config SERIAL_SAMSUNG_UARTS
+	int
+	depends on SERIAL_SAMSUNG
+	default 4
+	help
+	  Select the number of available UART ports for the Samsung S3C
+	  serial driver
+
+config SERIAL_SAMSUNG_CONSOLE
+	bool "Support for console on Samsung SoC serial port"
+	depends on SERIAL_SAMSUNG
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Allow selection of the S3C24XX on-board serial ports for use as
+	  an virtual console.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttySACx". (Try "man bootparam" or see the documentation of
+	  your boot loader about how to pass options to the kernel at
+	  boot time.)
+
+config SERIAL_TEGRA
+	tristate "NVIDIA Tegra20/30 SoC serial controller"
+	depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  Support for the on-chip UARTs on the NVIDIA Tegra series SOCs
+	  providing /dev/ttyTHS0, 1, 2, 3 and 4 (note, some machines may not
+	  provide all of these ports, depending on how the serial port
+	  are enabled). This driver uses the APB DMA to achieve higher baudrate
+	  and better performance.
+
+config SERIAL_TEGRA_TCU
+	tristate "NVIDIA Tegra Combined UART"
+	depends on MAILBOX
+	depends on (ARCH_TEGRA && TEGRA_HSP_MBOX) || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  Support for the mailbox-based TCU (Tegra Combined UART) serial port.
+	  TCU is a virtual serial port that allows multiplexing multiple data
+	  streams into a single hardware serial port.
+
+config SERIAL_TEGRA_TCU_CONSOLE
+	bool "Support for console on a Tegra TCU serial port"
+	depends on SERIAL_TEGRA_TCU=y
+	select SERIAL_CORE_CONSOLE
+	default y
+	help
+	  If you say Y here, it will be possible to use a the Tegra TCU as the
+	  system console (the system console is the device which receives all
+	  kernel messages and warnings and which allows logins in single user
+	  mode).
+
+	  If unsure, say Y.
+
+config SERIAL_MAX3100
+	tristate "MAX3100 support"
+	depends on SPI
+	select SERIAL_CORE
+	help
+	  MAX3100 chip support
+
+config SERIAL_MAX310X
+	tristate "MAX310X support"
+	depends on SPI_MASTER
+	select SERIAL_CORE
+	select REGMAP_SPI if SPI_MASTER
+	select REGMAP_I2C if I2C
+	help
+	  This selects support for an advanced UART from Maxim (Dallas).
+	  Supported ICs are MAX3107, MAX3108, MAX3109, MAX14830.
+	  Each IC contains 128 words each of receive and transmit FIFO
+	  that can be controlled through I2C or high-speed SPI.
+
+	  Say Y here if you want to support this ICs.
+
+config SERIAL_DZ
+	bool "DECstation DZ serial driver"
+	depends on MACH_DECSTATION && 32BIT
+	select SERIAL_CORE
+	default y
+	help
+	  DZ11-family serial controllers for DECstations and VAXstations,
+	  including the DC7085, M7814, and M7819.
+
+config SERIAL_DZ_CONSOLE
+	bool "Support console on DECstation DZ serial driver"
+	depends on SERIAL_DZ=y
+	select SERIAL_CORE_CONSOLE
+	default y
+	help
+	  If you say Y here, it will be possible to use a serial port as the
+	  system console (the system console is the device which receives all
+	  kernel messages and warnings and which allows logins in single user
+	  mode).
+
+	  Note that the firmware uses ttyS3 as the serial console on
+	  DECstations that use this driver.
+
+	  If unsure, say Y.
+
+config SERIAL_ZS
+	tristate "DECstation Z85C30 serial support"
+	depends on MACH_DECSTATION
+	select SERIAL_CORE
+	default y
+	help
+	  Support for the Zilog 85C350 serial communications controller used
+	  for serial ports in newer DECstation systems.  These include the
+	  DECsystem 5900 and all models of the DECstation and DECsystem 5000
+	  systems except from model 200.
+
+	  If unsure, say Y.  To compile this driver as a module, choose M here:
+	  the module will be called zs.
+
+config SERIAL_ZS_CONSOLE
+	bool "Support for console on a DECstation Z85C30 serial port"
+	depends on SERIAL_ZS=y
+	select SERIAL_CORE_CONSOLE
+	default y
+	help
+	  If you say Y here, it will be possible to use a serial port as the
+	  system console (the system console is the device which receives all
+	  kernel messages and warnings and which allows logins in single user
+	  mode).
+
+	  Note that the firmware uses ttyS1 as the serial console on the
+	  Maxine and ttyS3 on the others using this driver.
+
+	  If unsure, say Y.
+
+config SERIAL_21285
+	tristate "DC21285 serial port support"
+	depends on FOOTBRIDGE
+	select SERIAL_CORE
+	help
+	  If you have a machine based on a 21285 (Footbridge) StrongARM(R)/
+	  PCI bridge you can enable its onboard serial port by enabling this
+	  option.
+
+config SERIAL_21285_CONSOLE
+	bool "Console on DC21285 serial port"
+	depends on SERIAL_21285=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the serial port on the 21285 footbridge you can
+	  make it the console by answering Y to this option.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyFB". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
+config SERIAL_PXA
+	bool "PXA serial port support (DEPRECATED)"
+	depends on ARCH_PXA || ARCH_MMP
+	select SERIAL_CORE
+	select SERIAL_8250_PXA if SERIAL_8250=y
+	select SERIAL_PXA_NON8250 if !SERIAL_8250=y
+	help
+	  If you have a machine based on an Intel XScale PXA2xx CPU you
+	  can enable its onboard serial ports by enabling this option.
+
+	  Unless you have a specific need, you should use SERIAL_8250_PXA
+	  instead of this.
+
+config SERIAL_PXA_NON8250
+	bool
+	depends on !SERIAL_8250 || COMPILE_TEST
+
+config SERIAL_PXA_CONSOLE
+	bool "Console on PXA serial port (DEPRECATED)"
+	depends on SERIAL_PXA
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_8250_CONSOLE if SERIAL_8250=y
+	help
+	  If you have enabled the serial port on the Intel XScale PXA
+	  CPU you can make it the console by answering Y to this option.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttySA0". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
+	  Unless you have a specific need, you should use SERIAL_8250_PXA
+	  and SERIAL_8250_CONSOLE instead of this.
+
+config SERIAL_SA1100
+	bool "SA1100 serial port support"
+	depends on ARCH_SA1100
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  If you have a machine based on a SA1100/SA1110 StrongARM(R) CPU you
+	  can enable its onboard serial port by enabling this option.
+	  Please read <file:Documentation/arch/arm/sa1100/serial_uart.rst> for
+	  further info.
+
+config SERIAL_SA1100_CONSOLE
+	bool "Console on SA1100 serial port"
+	depends on SERIAL_SA1100
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the serial port on the SA1100/SA1110 StrongARM
+	  CPU you can make it the console by answering Y to this option.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttySA0". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
+config SERIAL_IMX
+	tristate "IMX serial port support"
+	depends on ARCH_MXC || COMPILE_TEST
+	select SERIAL_CORE
+	select RATIONAL
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  If you have a machine based on a Motorola IMX CPU you
+	  can enable its onboard serial port by enabling this option.
+
+config SERIAL_IMX_CONSOLE
+	tristate "Console on IMX serial port"
+	depends on SERIAL_IMX
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the serial port on the Freescale IMX
+	  CPU you can make it the console by answering Y/M to this option.
+
+	  Even if you say Y/M here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttymxc0". (Try "man bootparam" or see the documentation of
+	  your bootloader about how to pass options to the kernel at boot time.)
+
+config SERIAL_IMX_EARLYCON
+	bool "Earlycon on IMX serial port"
+	depends on ARCH_MXC || COMPILE_TEST
+	depends on OF
+	select SERIAL_CORE
+	select SERIAL_EARLYCON
+	select SERIAL_CORE_CONSOLE
+	default y if SERIAL_IMX_CONSOLE
+	help
+	  If you have enabled the earlycon on the Freescale IMX
+	  CPU you can make it the earlycon by answering Y to this option.
+
+config SERIAL_UARTLITE
+	tristate "Xilinx uartlite serial port support"
+	depends on HAS_IOMEM
+	select SERIAL_CORE
+	help
+	  Say Y here if you want to use the Xilinx uartlite serial controller.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called uartlite.
+
+config SERIAL_UARTLITE_CONSOLE
+	bool "Support for console on Xilinx uartlite serial port"
+	depends on SERIAL_UARTLITE=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Say Y here if you wish to use a Xilinx uartlite as the system
+	  console (the system console is the device which receives all kernel
+	  messages and warnings and which allows logins in single user mode).
+
+config SERIAL_UARTLITE_NR_UARTS
+	int "Maximum number of uartlite serial ports"
+	depends on SERIAL_UARTLITE
+	range 1 256
+	default 1
+	help
+	  Set this to the number of uartlites in your system, or the number
+	  you think you might implement.
+
+config SERIAL_SUNCORE
+	bool
+	depends on SPARC
+	select SERIAL_CORE
+	select SERIAL_CORE_CONSOLE
+	default y
+
+config SERIAL_SUNZILOG
+	tristate "Sun Zilog8530 serial support"
+	depends on SPARC
+	help
+	  This driver supports the Zilog8530 serial ports found on many Sparc
+	  systems.  Say Y or M if you want to be able to these serial ports.
+
+config SERIAL_SUNZILOG_CONSOLE
+	bool "Console on Sun Zilog8530 serial port"
+	depends on SERIAL_SUNZILOG=y
+	help
+	  If you would like to be able to use the Zilog8530 serial port
+	  on your Sparc system as the console, you can do so by answering
+	  Y to this option.
+
+config SERIAL_SUNSU
+	tristate "Sun SU serial support"
+	depends on SPARC && PCI
+	help
+	  This driver supports the 8250 serial ports that run the keyboard and
+	  mouse on (PCI) UltraSPARC systems.  Say Y or M if you want to be able
+	  to these serial ports.
+
+config SERIAL_SUNSU_CONSOLE
+	bool "Console on Sun SU serial port"
+	depends on SERIAL_SUNSU=y
+	help
+	  If you would like to be able to use the SU serial port
+	  on your Sparc system as the console, you can do so by answering
+	  Y to this option.
+
+config SERIAL_MUX
+	tristate "Serial MUX support"
+	depends on GSC
+	select SERIAL_CORE
+	default y
+	help
+	  Saying Y here will enable the hardware MUX serial driver for
+	  the Nova, K class systems and D class with a 'remote control card'.
+	  The hardware MUX is not 8250/16550 compatible therefore the
+	  /dev/ttyB0 device is shared between the Serial MUX and the PDC
+	  software console. The following steps need to be completed to use
+	  the Serial MUX:
+
+	    1. create the device entry (mknod /dev/ttyB0 c 11 0)
+	    2. Edit the /etc/inittab to start a getty listening on /dev/ttyB0
+	    3. Add device ttyB0 to /etc/securetty (if you want to log on as
+		 root on this console.)
+	    4. Change the kernel command console parameter to: console=ttyB0
+
+config SERIAL_MUX_CONSOLE
+	bool "Support for console on serial MUX"
+	depends on SERIAL_MUX=y
+	select SERIAL_CORE_CONSOLE
+	default y
+
+config SERIAL_SUNSAB
+	tristate "Sun Siemens SAB82532 serial support"
+	depends on SPARC && PCI
+	help
+	  This driver supports the Siemens SAB82532 DUSCC serial ports on newer
+	  (PCI) UltraSPARC systems.  Say Y or M if you want to be able to these
+	  serial ports.
+
+config SERIAL_SUNSAB_CONSOLE
+	bool "Console on Sun Siemens SAB82532 serial port"
+	depends on SERIAL_SUNSAB=y
+	help
+	  If you would like to be able to use the SAB82532 serial port
+	  on your Sparc system as the console, you can do so by answering
+	  Y to this option.
+
+config SERIAL_SUNHV
+	bool "Sun4v Hypervisor Console support"
+	depends on SPARC64
+	help
+	  This driver supports the console device found on SUN4V Sparc
+	  systems.  Say Y if you want to be able to use this device.
+
+config SERIAL_IP22_ZILOG
+	tristate "SGI Zilog8530 serial support"
+	depends on SGI_HAS_ZILOG
+	select SERIAL_CORE
+	help
+	  This driver supports the Zilog8530 serial ports found on SGI
+	  systems.  Say Y or M if you want to be able to these serial ports.
+
+config SERIAL_IP22_ZILOG_CONSOLE
+	bool "Console on SGI Zilog8530 serial port"
+	depends on SERIAL_IP22_ZILOG=y
+	select SERIAL_CORE_CONSOLE
+
+config SERIAL_SH_SCI
+	tristate "SuperH SCI(F) serial port support"
+	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+
+config SERIAL_SH_SCI_NR_UARTS
+	int "Maximum number of SCI(F) serial ports" if EXPERT
+	range 1 64 if 64BIT
+	range 1 32 if !64BIT
+	depends on SERIAL_SH_SCI
+	default "10" if SUPERH
+	default "18" if ARCH_RENESAS
+	default "2"
+
+config SERIAL_SH_SCI_CONSOLE
+	bool "Support for console on SuperH SCI(F)" if EXPERT
+	depends on SERIAL_SH_SCI=y
+	select SERIAL_CORE_CONSOLE
+	default y
+
+config SERIAL_SH_SCI_EARLYCON
+	bool "Support for early console on SuperH SCI(F)" if EXPERT
+	depends on SERIAL_SH_SCI=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	default ARCH_RENESAS
+
+config SERIAL_SH_SCI_DMA
+	bool "DMA support" if EXPERT
+	depends on SERIAL_SH_SCI && DMA_ENGINE
+	default ARCH_RENESAS
+
+config SERIAL_HS_LPC32XX
+	tristate "LPC32XX high speed serial port support"
+	depends on ARCH_LPC32XX || COMPILE_TEST
+	depends on OF
+	select SERIAL_CORE
+	help
+	  Support for the LPC32XX high speed serial ports (up to 900kbps).
+	  Those are UARTs completely different from the Standard UARTs on the
+	  LPC32XX SoC.
+	  Choose M or Y here to build this driver.
+
+config SERIAL_HS_LPC32XX_CONSOLE
+	bool "Enable LPC32XX high speed UART serial console"
+	depends on SERIAL_HS_LPC32XX=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you would like to be able to use one of the high speed serial
+	  ports on the LPC32XX as the console, you can do so by answering
+	  Y to this option.
+
+config SERIAL_CORE
+	tristate
+
+config SERIAL_CORE_CONSOLE
+	bool
+
+config CONSOLE_POLL
+	bool
+
+config SERIAL_MCF
+	bool "Coldfire serial support"
+	depends on COLDFIRE
+	select SERIAL_CORE
+	help
+	  This serial driver supports the Freescale Coldfire serial ports.
+
+config SERIAL_MCF_BAUDRATE
+	int "Default baudrate for Coldfire serial ports"
+	depends on SERIAL_MCF
+	default 19200
+	help
+	  This setting lets you define what the default baudrate is for the
+	  ColdFire serial ports. The usual default varies from board to board,
+	  and this setting is a way of catering for that.
+
+config SERIAL_MCF_CONSOLE
+	bool "Coldfire serial console support"
+	depends on SERIAL_MCF
+	select SERIAL_CORE_CONSOLE
+	help
+	  Enable a ColdFire internal serial port to be the system console.
+
+config SERIAL_PMACZILOG
+	tristate "Mac or PowerMac z85c30 ESCC support"
+	depends on (M68K && MAC) || PPC_PMAC
+	select SERIAL_CORE
+	help
+	  This driver supports the Zilog z85C30 serial ports found on
+	  (Power)Mac machines.
+	  Say Y or M if you want to be able to these serial ports.
+
+config SERIAL_PMACZILOG_TTYS
+	bool "Use ttySn device nodes for Zilog z85c30"
+	depends on SERIAL_PMACZILOG
+	help
+	  The pmac_zilog driver for the z85C30 chip on many powermacs
+	  historically used the device numbers for /dev/ttySn.  The
+	  8250 serial port driver also uses these numbers, which means
+	  the two drivers being unable to coexist; you could not use
+	  both z85C30 and 8250 type ports at the same time.
+
+	  If this option is not selected, the pmac_zilog driver will
+	  use the device numbers allocated for /dev/ttyPZn.  This allows
+	  the pmac_zilog and 8250 drivers to co-exist, but may cause
+	  existing userspace setups to break.  Programs that need to
+	  access the built-in serial ports on powermacs will need to
+	  be reconfigured to use /dev/ttyPZn instead of /dev/ttySn.
+
+	  If you enable this option, any z85c30 ports in the system will
+	  be registered as ttyS0 onwards as in the past, and you will be
+	  unable to use the 8250 module for PCMCIA or other 16C550-style
+	  UARTs.
+
+	  Say N unless you need the z85c30 ports on your (Power)Mac
+	  to appear as /dev/ttySn.
+
+config SERIAL_PMACZILOG_CONSOLE
+	bool "Console on Mac or PowerMac z85c30 serial port"
+	depends on SERIAL_PMACZILOG=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you would like to be able to use the z85c30 serial port
+	  on your (Power)Mac as the console, you can do so by answering
+	  Y to this option.
+
+config SERIAL_CPM
+	tristate "CPM SCC/SMC serial port support"
+	depends on CPM2 || CPM1
+	select SERIAL_CORE
+	help
+	  This driver supports the SCC and SMC serial ports on Motorola 
+	  embedded PowerPC that contain a CPM1 (8xx) or CPM2 (8xxx)
+
+config SERIAL_CPM_CONSOLE
+	bool "Support for console on CPM SCC/SMC serial port"
+	depends on SERIAL_CPM=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Say Y here if you wish to use a SCC or SMC CPM UART as the system
+	  console (the system console is the device which receives all kernel
+	  messages and warnings and which allows logins in single user mode).
+
+	  Even if you say Y here, the currently visible framebuffer console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyCPM0". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
+config SERIAL_PIC32
+	tristate "Microchip PIC32 serial support"
+	depends on MACH_PIC32 || (MIPS && COMPILE_TEST)
+	select SERIAL_CORE
+	help
+	  If you have a PIC32, this driver supports the serial ports.
+
+	  Say Y or M to use PIC32 serial ports, otherwise say N. Note that
+	  to use a serial port as a console, this must be included in kernel and
+	  not as a module.
+
+config SERIAL_PIC32_CONSOLE
+	bool "PIC32 serial console support"
+	depends on SERIAL_PIC32=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have a PIC32, this driver supports the putting a console on one
+	  of the serial ports.
+
+	  Say Y to use the PIC32 console, otherwise say N.
+
+config SERIAL_MPC52xx
+	tristate "Freescale MPC52xx/MPC512x family PSC serial support"
+	depends on PPC_MPC52xx || PPC_MPC512x
+	select SERIAL_CORE
+	help
+	  This driver supports MPC52xx and MPC512x PSC serial ports. If you would
+	  like to use them, you must answer Y or M to this option. Note that
+	  for use as console, it must be included in kernel and not as a
+	  module.
+
+config SERIAL_MPC52xx_CONSOLE
+	bool "Console on a Freescale MPC52xx/MPC512x family PSC serial port"
+	depends on SERIAL_MPC52xx=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Select this options if you'd like to use one of the PSC serial port
+	  of the Freescale MPC52xx family as a console.
+
+config SERIAL_MPC52xx_CONSOLE_BAUD
+	int "Freescale MPC52xx/MPC512x family PSC serial port baud"
+	depends on SERIAL_MPC52xx_CONSOLE=y
+	default "9600"
+	help
+	  Select the MPC52xx console baud rate.
+	  This value is only used if the bootloader doesn't pass in the
+	  console baudrate
+
+config SERIAL_ICOM
+	tristate "IBM Multiport Serial Adapter"
+	depends on PCI
+	depends on PPC_PSERIES || COMPILE_TEST
+	select SERIAL_CORE
+	select FW_LOADER
+	help
+	  This driver is for a family of multiport serial adapters
+	  including 2 port RVX, 2 port internal modem, 4 port internal
+	  modem and a split 1 port RVX and 1 port internal modem.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called icom.
+
+config SERIAL_TXX9
+	bool "TMPTX39XX/49XX SIO support"
+	depends on HAS_TXX9_SERIAL
+	select SERIAL_CORE
+	default y
+
+config HAS_TXX9_SERIAL
+	bool
+
+config SERIAL_TXX9_NR_UARTS
+	int "Maximum number of TMPTX39XX/49XX SIO ports"
+	depends on SERIAL_TXX9
+	default "6"
+
+config SERIAL_TXX9_CONSOLE
+	bool "TMPTX39XX/49XX SIO Console support"
+	depends on SERIAL_TXX9=y
+	select SERIAL_CORE_CONSOLE
+
+config SERIAL_TXX9_STDSERIAL
+	bool "TX39XX/49XX SIO act as standard serial"
+	depends on !SERIAL_8250 && SERIAL_TXX9
+
+config SERIAL_JSM
+	tristate "Digi International NEO and Classic PCI Support"
+	depends on PCI
+	select SERIAL_CORE
+	help
+	  This is a driver for Digi International's Neo and Classic series
+	  of cards which provide multiple serial ports. You would need
+	  something like this to connect more than two modems to your Linux
+	  box, for instance in order to become a dial-in server. This driver
+	  supports PCI boards only.
+
+	  If you have a card like this, say Y here, otherwise say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called jsm.
+
+config SERIAL_MSM
+	tristate "MSM on-chip serial port support"
+	depends on ARCH_QCOM || COMPILE_TEST
+	select SERIAL_CORE
+
+config SERIAL_MSM_CONSOLE
+	bool "MSM serial console support"
+	depends on SERIAL_MSM=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+
+config SERIAL_QCOM_GENI
+	tristate "QCOM on-chip GENI based serial port support"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on QCOM_GENI_SE
+	select SERIAL_CORE
+
+config SERIAL_QCOM_GENI_CONSOLE
+	bool "QCOM GENI Serial Console support"
+	depends on SERIAL_QCOM_GENI
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Serial console driver for Qualcomm Technologies Inc's GENI based
+	  QUP hardware.
+
+config SERIAL_VT8500
+	bool "VIA VT8500 on-chip serial port support"
+	depends on ARCH_VT8500 || COMPILE_TEST
+	select SERIAL_CORE
+
+config SERIAL_VT8500_CONSOLE
+	bool "VIA VT8500 serial console support"
+	depends on SERIAL_VT8500=y
+	select SERIAL_CORE_CONSOLE
+
+config SERIAL_OMAP
+	tristate "OMAP serial port support"
+	depends on (ARCH_OMAP2PLUS && !SERIAL_8250_OMAP) || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  If you have a machine based on an Texas Instruments OMAP CPU you
+	  can enable its onboard serial ports by enabling this option.
+
+	  By enabling this option you take advantage of dma feature available
+	  with the omap-serial driver. DMA support can be enabled from platform
+	  data.
+
+config SERIAL_OMAP_CONSOLE
+	bool "Console on OMAP serial port"
+	depends on SERIAL_OMAP=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Select this option if you would like to use omap serial port as
+	  console.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyOx". (Try "man bootparam" or see the documentation of
+	  your boot loader about how to pass options to the kernel at
+	  boot time.)
+
+config SERIAL_SIFIVE
+	tristate "SiFive UART support"
+	depends on OF
+	default ARCH_SIFIVE || ARCH_CANAAN
+	select SERIAL_CORE
+	help
+	  Select this option if you are building a kernel for a device that
+	  contains a SiFive UART IP block.  This type of UART is present on
+	  SiFive FU540 SoCs, among others.
+
+config SERIAL_SIFIVE_CONSOLE
+	bool "Console on SiFive UART"
+	depends on SERIAL_SIFIVE=y
+	default ARCH_SIFIVE || ARCH_CANAAN
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Select this option if you would like to use a SiFive UART as the
+	  system console.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttySIFx". (Try "man bootparam" or see the documentation of
+	  your boot loader about how to pass options to the kernel at
+	  boot time.)
+
+config SERIAL_LANTIQ
+	tristate "Lantiq serial driver"
+	depends on (LANTIQ || X86) || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  Support for UART on Lantiq and Intel SoCs.
+	  To compile this driver as a module, select M here. The
+	  module will be called lantiq.
+
+config SERIAL_LANTIQ_CONSOLE
+	bool "Console on Lantiq UART"
+	depends on SERIAL_LANTIQ=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Select this option if you would like to use a Lantiq UART as the
+	  system console.
+
+config SERIAL_QE
+	tristate "Freescale QUICC Engine serial port support"
+	depends on QUICC_ENGINE
+	select SERIAL_CORE
+	select FW_LOADER
+	help
+	  This driver supports the QE serial ports on Freescale embedded
+	  PowerPC that contain a QUICC Engine.
+
+config SERIAL_SCCNXP
+	tristate "SCCNXP serial port support"
+	select SERIAL_CORE
+	help
+	  This selects support for an advanced UART from NXP (Philips).
+	  Supported ICs are SCC2681, SCC2691, SCC2692, SC28L91, SC28L92,
+	  SC28L202, SCC68681 and SCC68692.
+
+config SERIAL_SCCNXP_CONSOLE
+	bool "Console on SCCNXP serial port"
+	depends on SERIAL_SCCNXP=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Support for console on SCCNXP serial ports.
+
+config SERIAL_SC16IS7XX_CORE
+	tristate
+
+config SERIAL_SC16IS7XX
+	tristate "SC16IS7xx serial support"
+	select SERIAL_CORE
+	depends on (SPI_MASTER && !I2C) || I2C
+	help
+	  This selects support for SC16IS7xx serial ports.
+	  Supported ICs are SC16IS740, SC16IS741, SC16IS750, SC16IS752,
+	  SC16IS760 and SC16IS762. Select supported buses using options below.
+
+config SERIAL_SC16IS7XX_I2C
+	bool "SC16IS7xx for I2C interface"
+	depends on SERIAL_SC16IS7XX
+	depends on I2C
+	select SERIAL_SC16IS7XX_CORE if SERIAL_SC16IS7XX
+	select REGMAP_I2C if I2C
+	default y
+	help
+	  Enable SC16IS7xx driver on I2C bus,
+	  If required say y, and say n to i2c if not required,
+	  Enabled by default to support oldconfig.
+	  You must select at least one bus for the driver to be built.
+
+config SERIAL_SC16IS7XX_SPI
+	bool "SC16IS7xx for spi interface"
+	depends on SERIAL_SC16IS7XX
+	depends on SPI_MASTER
+	select SERIAL_SC16IS7XX_CORE if SERIAL_SC16IS7XX
+	select REGMAP_SPI if SPI_MASTER
+	help
+	  Enable SC16IS7xx driver on SPI bus,
+	  If required say y, and say n to spi if not required,
+	  This is additional support to existing driver.
+	  You must select at least one bus for the driver to be built.
+
+config SERIAL_TIMBERDALE
+	tristate "Support for timberdale UART"
+	select SERIAL_CORE
+	depends on X86_32 || COMPILE_TEST
+	help
+	Add support for UART controller on timberdale.
+
+config SERIAL_BCM63XX
+	tristate "Broadcom BCM63xx/BCM33xx UART support"
+	select SERIAL_CORE
+	depends on ARCH_BCMBCA || BCM63XX || BMIPS_GENERIC || COMPILE_TEST
+	default ARCH_BCMBCA || BCM63XX || BMIPS_GENERIC
+	help
+	  This enables the driver for the onchip UART core found on
+	  the following chipsets:
+
+	    BCM33xx (cable modem)
+	    BCM63xx/BCM63xxx (DSL)
+	    BCM68xx (PON)
+	    BCM7xxx (STB) - DOCSIS console
+
+config SERIAL_BCM63XX_CONSOLE
+	bool "Console on BCM63xx serial port"
+	depends on SERIAL_BCM63XX=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  If you have enabled the serial port on the BCM63xx CPU
+	  you can make it the console by answering Y to this option.
+
+config SERIAL_GRLIB_GAISLER_APBUART
+	tristate "GRLIB APBUART serial support"
+	depends on OF && SPARC
+	select SERIAL_CORE
+	help
+	Add support for the GRLIB APBUART serial port.
+
+config SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
+	bool "Console on GRLIB APBUART serial port"
+	depends on SERIAL_GRLIB_GAISLER_APBUART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	Support for running a console on the GRLIB APBUART
+
+config SERIAL_ALTERA_JTAGUART
+	tristate "Altera JTAG UART support"
+	select SERIAL_CORE
+	help
+	  This driver supports the Altera JTAG UART port.
+
+config SERIAL_ALTERA_JTAGUART_CONSOLE
+	bool "Altera JTAG UART console support"
+	depends on SERIAL_ALTERA_JTAGUART=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Enable a Altera JTAG UART port to be the system console.
+
+config SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS
+	bool "Bypass output when no connection"
+	depends on SERIAL_ALTERA_JTAGUART_CONSOLE
+	select SERIAL_CORE_CONSOLE
+	help
+	  Bypass console output and keep going even if there is no
+	  JTAG terminal connection with the host.
+
+config SERIAL_ALTERA_UART
+	tristate "Altera UART support"
+	select SERIAL_CORE
+	help
+	  This driver supports the Altera softcore UART port.
+
+config SERIAL_ALTERA_UART_MAXPORTS
+	int "Maximum number of Altera UART ports"
+	depends on SERIAL_ALTERA_UART
+	default 4
+	help
+	  This setting lets you define the maximum number of the Altera
+	  UART ports. The usual default varies from board to board, and
+	  this setting is a way of catering for that.
+
+config SERIAL_ALTERA_UART_BAUDRATE
+	int "Default baudrate for Altera UART ports"
+	depends on SERIAL_ALTERA_UART
+	default 115200
+	help
+	  This setting lets you define what the default baudrate is for the
+	  Altera UART ports. The usual default varies from board to board,
+	  and this setting is a way of catering for that.
+
+config SERIAL_ALTERA_UART_CONSOLE
+	bool "Altera UART console support"
+	depends on SERIAL_ALTERA_UART=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Enable a Altera UART port to be the system console.
+
+config SERIAL_PCH_UART
+	tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) UART"
+	depends on PCI && (X86_32 || MIPS ||  COMPILE_TEST)
+	select SERIAL_CORE
+	help
+	  This driver is for PCH(Platform controller Hub) UART of Intel EG20T
+	  which is an IOH(Input/Output Hub) for x86 embedded processor.
+	  Enabling PCH_DMA, this PCH UART works as DMA mode.
+
+	  This driver also can be used for LAPIS Semiconductor IOH(Input/
+	  Output Hub), ML7213, ML7223 and ML7831.
+	  ML7213 IOH is for IVI(In-Vehicle Infotainment) use, ML7223 IOH is
+	  for MP(Media Phone) use and ML7831 IOH is for general purpose use.
+	  ML7213/ML7223/ML7831 is companion chip for Intel Atom E6xx series.
+	  ML7213/ML7223/ML7831 is completely compatible for Intel EG20T PCH.
+
+config SERIAL_PCH_UART_CONSOLE
+	bool "Support for console on Intel EG20T PCH UART/OKI SEMICONDUCTOR ML7213 IOH"
+	depends on SERIAL_PCH_UART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Say Y here if you wish to use the PCH UART as the system console
+	  (the system  console is the device which receives all kernel messages and
+	  warnings and which allows logins in single user mode).
+
+config SERIAL_MXS_AUART
+	tristate "MXS AUART support"
+	depends on ARCH_MXS || MACH_ASM9260 || COMPILE_TEST
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  This driver supports the MXS and Alphascale ASM9260 Application
+	  UART (AUART) port.
+
+config SERIAL_MXS_AUART_CONSOLE
+	bool "MXS AUART console support"
+	depends on SERIAL_MXS_AUART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Enable a MXS AUART port to be the system console.
+
+config SERIAL_XILINX_PS_UART
+	tristate "Cadence (Xilinx Zynq) UART support"
+	depends on OF
+	select SERIAL_CORE
+	help
+	  This driver supports the Cadence UART. It is found e.g. in Xilinx
+	  Zynq.
+
+config SERIAL_XILINX_PS_UART_CONSOLE
+	bool "Cadence UART console support"
+	depends on SERIAL_XILINX_PS_UART=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Enable a Cadence UART port to be the system console.
+
+config SERIAL_AR933X
+	tristate "AR933X serial port support"
+	depends on (HAVE_CLK && ATH79) || (MIPS && COMPILE_TEST)
+	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  If you have an Atheros AR933X SOC based board and want to use the
+	  built-in UART of the SoC, say Y to this option.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ar933x_uart.
+
+config SERIAL_AR933X_CONSOLE
+	bool "Console on AR933X serial port"
+	depends on SERIAL_AR933X=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Enable a built-in UART port of the AR933X to be the system console.
+
+config SERIAL_AR933X_NR_UARTS
+	int "Maximum number of AR933X serial ports"
+	depends on SERIAL_AR933X
+	default "2"
+	help
+	  Set this to the number of serial ports you want the driver
+	  to support.
+
+config SERIAL_MPS2_UART_CONSOLE
+	bool "MPS2 UART console support"
+	depends on SERIAL_MPS2_UART
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+
+config SERIAL_MPS2_UART
+	bool "MPS2 UART port"
+	depends on ARCH_MPS2 || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver support the UART ports on ARM MPS2.
+
+config SERIAL_ARC
+	tristate "ARC UART driver support"
+	select SERIAL_CORE
+	help
+	  Driver for on-chip UART for ARC(Synopsys) for the legacy
+	  FPGA Boards (ML50x/ARCAngel4)
+
+config SERIAL_ARC_CONSOLE
+	bool "Console on ARC UART"
+	depends on SERIAL_ARC=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Enable system Console on ARC UART
+
+config SERIAL_ARC_NR_PORTS
+	int "Number of ARC UART ports"
+	depends on SERIAL_ARC
+	range 1 3
+	default "1"
+	help
+	  Set this to the number of serial ports you want the driver
+	  to support.
+
+config SERIAL_RP2
+	tristate "Comtrol RocketPort EXPRESS/INFINITY support"
+	depends on PCI
+	select SERIAL_CORE
+	help
+	  This driver supports the Comtrol RocketPort EXPRESS and
+	  RocketPort INFINITY families of PCI/PCIe multiport serial adapters.
+	  These adapters use a "RocketPort 2" ASIC that is not compatible
+	  with the original RocketPort driver (CONFIG_ROCKETPORT).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rp2.
+
+	  If you want to compile this driver into the kernel, say Y here.  If
+	  you don't have a suitable RocketPort card installed, say N.
+
+config SERIAL_RP2_NR_UARTS
+	int "Maximum number of RocketPort EXPRESS/INFINITY ports"
+	depends on SERIAL_RP2
+	default "32"
+	help
+	  If multiple cards are present, the default limit of 32 ports may
+	  need to be increased.
+
+config SERIAL_FSL_LPUART
+	tristate "Freescale lpuart serial port support"
+	depends on HAS_DMA
+	select SERIAL_CORE
+	help
+	  Support for the on-chip lpuart on some Freescale SOCs.
+
+config SERIAL_FSL_LPUART_CONSOLE
+	bool "Console on Freescale lpuart serial port"
+	depends on SERIAL_FSL_LPUART=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  If you have enabled the lpuart serial port on the Freescale SoCs,
+	  you can make it the console by answering Y to this option.
+
+config SERIAL_FSL_LINFLEXUART
+	tristate "Freescale LINFlexD UART serial port support"
+	depends on PRINTK
+	select SERIAL_CORE
+	help
+	  Support for the on-chip LINFlexD UART on some Freescale SOCs.
+
+config SERIAL_FSL_LINFLEXUART_CONSOLE
+	bool "Console on Freescale LINFlexD UART serial port"
+	depends on SERIAL_FSL_LINFLEXUART=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  If you have enabled the LINFlexD UART serial port on the Freescale
+	  SoCs, you can make it the console by answering Y to this option.
+
+config SERIAL_CONEXANT_DIGICOLOR
+	tristate "Conexant Digicolor CX92xxx USART serial port support"
+	depends on OF
+	select SERIAL_CORE
+	help
+	  Support for the on-chip USART on Conexant Digicolor SoCs.
+
+config SERIAL_CONEXANT_DIGICOLOR_CONSOLE
+	bool "Console on Conexant Digicolor serial port"
+	depends on SERIAL_CONEXANT_DIGICOLOR=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the USART serial port on Conexant Digicolor
+	  SoCs, you can make it the console by answering Y to this option.
+
+config SERIAL_ST_ASC
+	tristate "ST ASC serial port support"
+	select SERIAL_CORE
+	depends on ARM || COMPILE_TEST
+	help
+	  This driver is for the on-chip Asynchronous Serial Controller on
+	  STMicroelectronics STi SoCs.
+	  ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
+	  It support all industry standard baud rates.
+
+	  If unsure, say N.
+
+config SERIAL_ST_ASC_CONSOLE
+	bool "Support for console on ST ASC"
+	depends on SERIAL_ST_ASC=y
+	select SERIAL_CORE_CONSOLE
+
+config SERIAL_MEN_Z135
+	tristate "MEN 16z135 Support"
+	select SERIAL_CORE
+	depends on MCB
+	help
+	  Say yes here to enable support for the MEN 16z135 High Speed UART IP-Core
+	  on a MCB carrier.
+
+	  This driver can also be build as a module. If so, the module will be called
+	  men_z135_uart.ko
+
+config SERIAL_SPRD
+	tristate "Support for Spreadtrum serial"
+	select SERIAL_CORE
+	depends on COMMON_CLK
+	help
+	  This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_CONSOLE
+	bool "Spreadtrum UART console support"
+	depends on SERIAL_SPRD=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Support for early debug console using Spreadtrum's serial. This enables
+	  the console before standard serial driver is probed. This is enabled
+	  with "earlycon" on the kernel command line. The console is
+	  enabled when early_param is processed.
+
+config SERIAL_STM32
+	tristate "STMicroelectronics STM32 serial port support"
+	select SERIAL_CORE
+	depends on ARCH_STM32 || COMPILE_TEST
+	select SERIAL_MCTRL_GPIO if GPIOLIB
+	help
+	  This driver is for the on-chip Serial Controller on
+	  STMicroelectronics STM32 MCUs.
+	  USART supports Rx & Tx functionality.
+	  It support all industry standard baud rates.
+
+	  If unsure, say N.
+
+config SERIAL_STM32_CONSOLE
+	bool "Support for console on STM32"
+	depends on SERIAL_STM32=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+
+config SERIAL_MVEBU_UART
+	bool "Marvell EBU serial port support"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on COMMON_CLK
+	select SERIAL_CORE
+	help
+	  This driver is for Marvell EBU SoC's UART. If you have a machine
+	  based on the Armada-3700 SoC and wish to use the on-board serial
+	  port,
+	  say 'Y' here.
+	  Otherwise, say 'N'.
+
+config SERIAL_MVEBU_CONSOLE
+	bool "Console on Marvell EBU serial port"
+	depends on SERIAL_MVEBU_UART
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	default y
+	help
+	  Say 'Y' here if you wish to use Armada-3700 UART as the system console.
+	  (the system console is the device which receives all kernel messages
+	  and warnings and which allows logins in single user mode)
+	  Otherwise, say 'N'.
+
+config SERIAL_OWL
+	tristate "Actions Semi Owl serial port support"
+	depends on ARCH_ACTIONS || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver is for Actions Semiconductor S500/S900 SoC's UART.
+	  Say 'Y' here if you wish to use the on-board serial port.
+	  Otherwise, say 'N'.
+
+config SERIAL_OWL_CONSOLE
+	bool "Console on Actions Semi Owl serial port"
+	depends on SERIAL_OWL=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	default y
+	help
+	  Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART
+	  as the system console.
+
+config SERIAL_RDA
+	bool "RDA Micro serial port support"
+	depends on ARCH_RDA || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver is for RDA8810PL SoC's UART.
+	  Say 'Y' here if you wish to use the on-board serial port.
+	  Otherwise, say 'N'.
+
+config SERIAL_RDA_CONSOLE
+	bool "Console on RDA Micro serial port"
+	depends on SERIAL_RDA=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	default y
+	help
+	  Say 'Y' here if you wish to use the RDA8810PL UART as the system
+	  console. Only earlycon is implemented currently.
+
+config SERIAL_MILBEAUT_USIO
+	tristate "Milbeaut USIO/UART serial port support"
+	depends on ARCH_MILBEAUT || (COMPILE_TEST && OF)
+	default ARCH_MILBEAUT
+	select SERIAL_CORE
+	help
+	  This selects the USIO/UART IP found in Socionext Milbeaut SoCs.
+
+config SERIAL_MILBEAUT_USIO_PORTS
+	int "Maximum number of CSIO/UART ports (1-8)"
+	range 1 8
+	depends on SERIAL_MILBEAUT_USIO
+	default "4"
+
+config SERIAL_MILBEAUT_USIO_CONSOLE
+	bool "Support for console on MILBEAUT USIO/UART serial port"
+	depends on SERIAL_MILBEAUT_USIO=y
+	default y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Say 'Y' here if you wish to use a USIO/UART of Socionext Milbeaut
+	  SoCs as the system console (the system console is the device which
+	  receives all kernel messages and warnings and which allows logins in
+	  single user mode).
+
+config SERIAL_LITEUART
+	tristate "LiteUART serial port support"
+	depends on HAS_IOMEM
+	depends on OF
+	depends on LITEX || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver is for the FPGA-based LiteUART serial controller from LiteX
+	  SoC builder.
+
+	  Say 'Y' or 'M' here if you wish to use the LiteUART serial controller.
+	  Otherwise, say 'N'.
+
+config SERIAL_LITEUART_MAX_PORTS
+	int "Maximum number of LiteUART ports"
+	depends on SERIAL_LITEUART
+	default "1"
+	help
+	  Set this to the maximum number of serial ports you want the driver
+	  to support.
+
+config SERIAL_LITEUART_CONSOLE
+	bool "LiteUART serial port console support"
+	depends on SERIAL_LITEUART=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Say 'Y' or 'M' here if you wish to use the FPGA-based LiteUART serial
+	  controller from LiteX SoC builder as the system console
+	  (the system console is the device which receives all kernel messages
+	  and warnings and which allows logins in single user mode).
+	  Otherwise, say 'N'.
+
+config SERIAL_SUNPLUS
+	tristate "Sunplus UART support"
+	depends on ARCH_SUNPLUS || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  Select this option if you would like to use Sunplus serial port on
+	  Sunplus SoC SP7021.
+	  If you enable this option, Sunplus serial ports in the system will
+	  be registered as ttySUPx.
+	  This driver can also be built as a module. If so, the module will be
+	  called sunplus-uart.
+
+config SERIAL_SUNPLUS_CONSOLE
+	bool "Console on Sunplus UART"
+	depends on SERIAL_SUNPLUS
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Select this option if you would like to use a Sunplus UART as the
+	  system console.
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttySUPx".
+
+config SERIAL_NUVOTON_MA35D1
+	tristate "Nuvoton MA35D1 family UART support"
+	depends on ARCH_MA35 || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver supports Nuvoton MA35D1 family UART ports. If you would
+	  like to use them, you must answer Y or M to this option. Note that
+	  for use as console, it must be included in kernel and not as a
+	  module. If you enable this option, Ma35D1 serial ports in the system
+	  will be registered as ttyNVTx.
+
+config SERIAL_NUVOTON_MA35D1_CONSOLE
+	bool "Console on a Nuvotn MA35D1 family UART port"
+	depends on SERIAL_NUVOTON_MA35D1=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Select this options if you'd like to use the UART port0 of the
+	  Nuvoton MA35D1 family as a console.
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default,
+	  but you can alter that using a kernel command line option such as
+	  "console=ttyNVTx".
+
+endmenu
+
+config SERIAL_MCTRL_GPIO
+	tristate
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
new file mode 100644
index 000000000..138abbc89
--- /dev/null
+++ b/drivers/tty/serial/Makefile
@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the kernel serial device drivers.
+#
+
+obj-$(CONFIG_SERIAL_CORE) += serial_base.o
+serial_base-y := serial_core.o serial_base_bus.o serial_ctrl.o serial_port.o
+
+obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o
+obj-$(CONFIG_SERIAL_EARLYCON_SEMIHOST) += earlycon-semihost.o
+obj-$(CONFIG_SERIAL_EARLYCON_RISCV_SBI) += earlycon-riscv-sbi.o
+
+# These Sparc drivers have to appear before others such as 8250
+# which share ttySx minor node space.  Otherwise console device
+# names change and other unplesantries.
+obj-$(CONFIG_SERIAL_SUNCORE) += suncore.o
+obj-$(CONFIG_SERIAL_SUNHV) += sunhv.o
+obj-$(CONFIG_SERIAL_SUNZILOG) += sunzilog.o
+obj-$(CONFIG_SERIAL_SUNSU) += sunsu.o
+obj-$(CONFIG_SERIAL_SUNSAB) += sunsab.o
+
+obj-$(CONFIG_SERIAL_21285) += 21285.o
+
+# Now bring in any enabled 8250/16450/16550 type drivers.
+obj-y += 8250/
+
+obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o
+obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
+obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
+obj-$(CONFIG_SERIAL_PXA_NON8250) += pxa.o
+obj-$(CONFIG_SERIAL_SA1100) += sa1100.o
+obj-$(CONFIG_SERIAL_BCM63XX) += bcm63xx_uart.o
+obj-$(CONFIG_SERIAL_SAMSUNG) += samsung_tty.o
+obj-$(CONFIG_SERIAL_MAX3100) += max3100.o
+obj-$(CONFIG_SERIAL_MAX310X) += max310x.o
+obj-$(CONFIG_SERIAL_IP22_ZILOG) += ip22zilog.o
+obj-$(CONFIG_SERIAL_MUX) += mux.o
+obj-$(CONFIG_SERIAL_MCF) += mcf.o
+obj-$(CONFIG_SERIAL_PMACZILOG) += pmac_zilog.o
+obj-$(CONFIG_SERIAL_HS_LPC32XX) += lpc32xx_hs.o
+obj-$(CONFIG_SERIAL_DZ) += dz.o
+obj-$(CONFIG_SERIAL_ZS) += zs.o
+obj-$(CONFIG_SERIAL_SH_SCI) += sh-sci.o
+obj-$(CONFIG_SERIAL_CPM) += cpm_uart.o
+obj-$(CONFIG_SERIAL_IMX) += imx.o
+obj-$(CONFIG_SERIAL_IMX_EARLYCON) += imx_earlycon.o
+obj-$(CONFIG_SERIAL_MPC52xx) += mpc52xx_uart.o
+obj-$(CONFIG_SERIAL_ICOM) += icom.o
+obj-$(CONFIG_SERIAL_MESON) += meson_uart.o
+obj-$(CONFIG_SERIAL_SB1250_DUART) += sb1250-duart.o
+obj-$(CONFIG_SERIAL_SCCNXP) += sccnxp.o
+obj-$(CONFIG_SERIAL_SC16IS7XX_CORE) += sc16is7xx.o
+obj-$(CONFIG_SERIAL_JSM) += jsm/
+obj-$(CONFIG_SERIAL_TXX9) += serial_txx9.o
+obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
+obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
+obj-$(CONFIG_SERIAL_MSM) += msm_serial.o
+obj-$(CONFIG_SERIAL_QCOM_GENI) += qcom_geni_serial.o
+obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
+obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
+obj-$(CONFIG_SERIAL_ST_ASC) += st-asc.o
+obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
+obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
+obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o
+obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
+obj-$(CONFIG_SERIAL_VT8500) += vt8500_serial.o
+obj-$(CONFIG_SERIAL_PCH_UART)	+= pch_uart.o
+obj-$(CONFIG_SERIAL_MXS_AUART) += mxs-auart.o
+obj-$(CONFIG_SERIAL_LANTIQ)	+= lantiq.o
+obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
+obj-$(CONFIG_SERIAL_TEGRA) += serial-tegra.o
+obj-$(CONFIG_SERIAL_TEGRA_TCU) += tegra-tcu.o
+obj-$(CONFIG_SERIAL_AR933X)   += ar933x_uart.o
+obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
+obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
+obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o
+obj-$(CONFIG_SERIAL_FSL_LINFLEXUART)	+= fsl_linflexuart.o
+obj-$(CONFIG_SERIAL_CONEXANT_DIGICOLOR)	+= digicolor-usart.o
+obj-$(CONFIG_SERIAL_MEN_Z135)	+= men_z135_uart.o
+obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
+obj-$(CONFIG_SERIAL_STM32)	+= stm32-usart.o
+obj-$(CONFIG_SERIAL_MVEBU_UART)	+= mvebu-uart.o
+obj-$(CONFIG_SERIAL_PIC32)	+= pic32_uart.o
+obj-$(CONFIG_SERIAL_MPS2_UART)	+= mps2-uart.o
+obj-$(CONFIG_SERIAL_OWL)	+= owl-uart.o
+obj-$(CONFIG_SERIAL_RDA)	+= rda-uart.o
+obj-$(CONFIG_SERIAL_MILBEAUT_USIO) += milbeaut_usio.o
+obj-$(CONFIG_SERIAL_SIFIVE)	+= sifive.o
+obj-$(CONFIG_SERIAL_LITEUART) += liteuart.o
+obj-$(CONFIG_SERIAL_SUNPLUS)	+= sunplus-uart.o
+
+# GPIOLIB helpers for modem control lines
+obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o
+
+obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
+obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
+obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
new file mode 100644
index 000000000..5fab4c978
--- /dev/null
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -0,0 +1,486 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * altera_jtaguart.c -- Altera JTAG UART driver
+ *
+ * Based on mcf.c -- Freescale ColdFire UART driver
+ *
+ * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
+ * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
+ * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/of.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/altera_jtaguart.h>
+
+#define DRV_NAME "altera_jtaguart"
+
+/*
+ * Altera JTAG UART register definitions according to the Altera JTAG UART
+ * datasheet: https://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
+ */
+
+#define ALTERA_JTAGUART_SIZE			8
+
+#define ALTERA_JTAGUART_DATA_REG		0
+
+#define ALTERA_JTAGUART_DATA_DATA_MSK		0x000000FF
+#define ALTERA_JTAGUART_DATA_RVALID_MSK		0x00008000
+#define ALTERA_JTAGUART_DATA_RAVAIL_MSK		0xFFFF0000
+#define ALTERA_JTAGUART_DATA_RAVAIL_OFF		16
+
+#define ALTERA_JTAGUART_CONTROL_REG		4
+
+#define ALTERA_JTAGUART_CONTROL_RE_MSK		0x00000001
+#define ALTERA_JTAGUART_CONTROL_WE_MSK		0x00000002
+#define ALTERA_JTAGUART_CONTROL_RI_MSK		0x00000100
+#define ALTERA_JTAGUART_CONTROL_RI_OFF		8
+#define ALTERA_JTAGUART_CONTROL_WI_MSK		0x00000200
+#define ALTERA_JTAGUART_CONTROL_AC_MSK		0x00000400
+#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK	0xFFFF0000
+
+static unsigned int altera_jtaguart_tx_space(struct uart_port *port, u32 *ctlp)
+{
+	u32 ctl = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	if (ctlp)
+		*ctlp = ctl;
+
+	return FIELD_GET(ALTERA_JTAGUART_CONTROL_WSPACE_MSK, ctl);
+}
+
+static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
+{
+	return altera_jtaguart_tx_space(port, NULL) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs)
+{
+}
+
+static void altera_jtaguart_start_tx(struct uart_port *port)
+{
+	port->read_status_mask |= ALTERA_JTAGUART_CONTROL_WE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static void altera_jtaguart_stop_tx(struct uart_port *port)
+{
+	port->read_status_mask &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static void altera_jtaguart_stop_rx(struct uart_port *port)
+{
+	port->read_status_mask &= ~ALTERA_JTAGUART_CONTROL_RE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static void altera_jtaguart_set_termios(struct uart_port *port,
+				        struct ktermios *termios,
+				        const struct ktermios *old)
+{
+	/* Just copy the old termios settings back */
+	if (old)
+		tty_termios_copy_hw(termios, old);
+}
+
+static void altera_jtaguart_rx_chars(struct uart_port *port)
+{
+	u32 status;
+	u8 ch;
+
+	while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
+	       ALTERA_JTAGUART_DATA_RVALID_MSK) {
+		ch = status & ALTERA_JTAGUART_DATA_DATA_MSK;
+		port->icount.rx++;
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+		uart_insert_char(port, 0, 0, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void altera_jtaguart_tx_chars(struct uart_port *port)
+{
+	unsigned int count;
+	u8 ch;
+
+	count = altera_jtaguart_tx_space(port, NULL);
+
+	uart_port_tx_limited(port, ch, count,
+		true,
+		writel(ch, port->membase + ALTERA_JTAGUART_DATA_REG),
+		({}));
+}
+
+static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
+{
+	struct uart_port *port = data;
+	unsigned int isr;
+
+	isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
+	       ALTERA_JTAGUART_CONTROL_RI_OFF) & port->read_status_mask;
+
+	spin_lock(&port->lock);
+
+	if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
+		altera_jtaguart_rx_chars(port);
+	if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
+		altera_jtaguart_tx_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_RETVAL(isr);
+}
+
+static void altera_jtaguart_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_ALTERA_JTAGUART;
+
+	/* Clear mask, so no surprise interrupts. */
+	writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static int altera_jtaguart_startup(struct uart_port *port)
+{
+	unsigned long flags;
+	int ret;
+
+	ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
+			DRV_NAME, port);
+	if (ret) {
+		pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d "
+		       "interrupt vector=%d\n", port->line, port->irq);
+		return ret;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Enable RX interrupts now */
+	port->read_status_mask = ALTERA_JTAGUART_CONTROL_RE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void altera_jtaguart_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable all interrupts now */
+	port->read_status_mask = 0;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+static const char *altera_jtaguart_type(struct uart_port *port)
+{
+	return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL;
+}
+
+static int altera_jtaguart_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+static void altera_jtaguart_release_port(struct uart_port *port)
+{
+	/* Nothing to release... */
+}
+
+static int altera_jtaguart_verify_port(struct uart_port *port,
+				       struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ *	Define the basic serial functions we support.
+ */
+static const struct uart_ops altera_jtaguart_ops = {
+	.tx_empty	= altera_jtaguart_tx_empty,
+	.get_mctrl	= altera_jtaguart_get_mctrl,
+	.set_mctrl	= altera_jtaguart_set_mctrl,
+	.start_tx	= altera_jtaguart_start_tx,
+	.stop_tx	= altera_jtaguart_stop_tx,
+	.stop_rx	= altera_jtaguart_stop_rx,
+	.break_ctl	= altera_jtaguart_break_ctl,
+	.startup	= altera_jtaguart_startup,
+	.shutdown	= altera_jtaguart_shutdown,
+	.set_termios	= altera_jtaguart_set_termios,
+	.type		= altera_jtaguart_type,
+	.request_port	= altera_jtaguart_request_port,
+	.release_port	= altera_jtaguart_release_port,
+	.config_port	= altera_jtaguart_config_port,
+	.verify_port	= altera_jtaguart_verify_port,
+};
+
+#define ALTERA_JTAGUART_MAXPORTS 1
+static struct uart_port altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
+
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
+
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
+static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+	u32 status;
+
+	spin_lock_irqsave(&port->lock, flags);
+	while (!altera_jtaguart_tx_space(port, &status)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
+			return;	/* no connection activity */
+		}
+
+		cpu_relax();
+		spin_lock_irqsave(&port->lock, flags);
+	}
+	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+#else
+static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	while (!altera_jtaguart_tx_space(port, NULL)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		cpu_relax();
+		spin_lock_irqsave(&port->lock, flags);
+	}
+	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+#endif
+
+static void altera_jtaguart_console_write(struct console *co, const char *s,
+					  unsigned int count)
+{
+	struct uart_port *port = &altera_jtaguart_ports[co->index];
+
+	uart_console_write(port, s, count, altera_jtaguart_console_putc);
+}
+
+static int __init altera_jtaguart_console_setup(struct console *co,
+						char *options)
+{
+	struct uart_port *port;
+
+	if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS)
+		return -EINVAL;
+	port = &altera_jtaguart_ports[co->index];
+	if (port->membase == NULL)
+		return -ENODEV;
+	return 0;
+}
+
+static struct uart_driver altera_jtaguart_driver;
+
+static struct console altera_jtaguart_console = {
+	.name	= "ttyJ",
+	.write	= altera_jtaguart_console_write,
+	.device	= uart_console_device,
+	.setup	= altera_jtaguart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &altera_jtaguart_driver,
+};
+
+static int __init altera_jtaguart_console_init(void)
+{
+	register_console(&altera_jtaguart_console);
+	return 0;
+}
+
+console_initcall(altera_jtaguart_console_init);
+
+#define	ALTERA_JTAGUART_CONSOLE	(&altera_jtaguart_console)
+
+static void altera_jtaguart_earlycon_write(struct console *co, const char *s,
+					   unsigned int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	uart_console_write(&dev->port, s, count, altera_jtaguart_console_putc);
+}
+
+static int __init altera_jtaguart_earlycon_setup(struct earlycon_device *dev,
+						 const char *options)
+{
+	if (!dev->port.membase)
+		return -ENODEV;
+
+	dev->con->write = altera_jtaguart_earlycon_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(juart, "altr,juart-1.0", altera_jtaguart_earlycon_setup);
+
+#else
+
+#define	ALTERA_JTAGUART_CONSOLE	NULL
+
+#endif /* CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE */
+
+static struct uart_driver altera_jtaguart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "altera_jtaguart",
+	.dev_name	= "ttyJ",
+	.major		= ALTERA_JTAGUART_MAJOR,
+	.minor		= ALTERA_JTAGUART_MINOR,
+	.nr		= ALTERA_JTAGUART_MAXPORTS,
+	.cons		= ALTERA_JTAGUART_CONSOLE,
+};
+
+static int altera_jtaguart_probe(struct platform_device *pdev)
+{
+	struct altera_jtaguart_platform_uart *platp =
+			dev_get_platdata(&pdev->dev);
+	struct uart_port *port;
+	struct resource *res_mem;
+	int i = pdev->id;
+	int irq;
+
+	/* -1 emphasizes that the platform must have one port, no .N suffix */
+	if (i == -1)
+		i = 0;
+
+	if (i >= ALTERA_JTAGUART_MAXPORTS)
+		return -EINVAL;
+
+	port = &altera_jtaguart_ports[i];
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res_mem)
+		port->mapbase = res_mem->start;
+	else if (platp)
+		port->mapbase = platp->mapbase;
+	else
+		return -ENODEV;
+
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
+		return irq;
+	if (irq > 0)
+		port->irq = irq;
+	else if (platp)
+		port->irq = platp->irq;
+	else
+		return -ENODEV;
+
+	port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
+	if (!port->membase)
+		return -ENOMEM;
+
+	port->line = i;
+	port->type = PORT_ALTERA_JTAGUART;
+	port->iotype = SERIAL_IO_MEM;
+	port->ops = &altera_jtaguart_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
+
+	uart_add_one_port(&altera_jtaguart_driver, port);
+
+	return 0;
+}
+
+static int altera_jtaguart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port;
+	int i = pdev->id;
+
+	if (i == -1)
+		i = 0;
+
+	port = &altera_jtaguart_ports[i];
+	uart_remove_one_port(&altera_jtaguart_driver, port);
+	iounmap(port->membase);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id altera_jtaguart_match[] = {
+	{ .compatible = "ALTR,juart-1.0", },
+	{ .compatible = "altr,juart-1.0", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
+#endif /* CONFIG_OF */
+
+static struct platform_driver altera_jtaguart_platform_driver = {
+	.probe	= altera_jtaguart_probe,
+	.remove	= altera_jtaguart_remove,
+	.driver	= {
+		.name		= DRV_NAME,
+		.of_match_table	= of_match_ptr(altera_jtaguart_match),
+	},
+};
+
+static int __init altera_jtaguart_init(void)
+{
+	int rc;
+
+	rc = uart_register_driver(&altera_jtaguart_driver);
+	if (rc)
+		return rc;
+	rc = platform_driver_register(&altera_jtaguart_platform_driver);
+	if (rc)
+		uart_unregister_driver(&altera_jtaguart_driver);
+	return rc;
+}
+
+static void __exit altera_jtaguart_exit(void)
+{
+	platform_driver_unregister(&altera_jtaguart_platform_driver);
+	uart_unregister_driver(&altera_jtaguart_driver);
+}
+
+module_init(altera_jtaguart_init);
+module_exit(altera_jtaguart_exit);
+
+MODULE_DESCRIPTION("Altera JTAG UART driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
new file mode 100644
index 000000000..a9c419421
--- /dev/null
+++ b/drivers/tty/serial/altera_uart.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * altera_uart.c -- Altera UART driver
+ *
+ * Based on mcf.c -- Freescale ColdFire UART driver
+ *
+ * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
+ * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
+ * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/altera_uart.h>
+
+#define DRV_NAME "altera_uart"
+#define SERIAL_ALTERA_MAJOR 204
+#define SERIAL_ALTERA_MINOR 213
+
+/*
+ * Altera UART register definitions according to the Nios UART datasheet:
+ * http://www.altera.com/literature/ds/ds_nios_uart.pdf
+ */
+
+#define ALTERA_UART_SIZE		32
+
+#define ALTERA_UART_RXDATA_REG		0
+#define ALTERA_UART_TXDATA_REG		4
+#define ALTERA_UART_STATUS_REG		8
+#define ALTERA_UART_CONTROL_REG		12
+#define ALTERA_UART_DIVISOR_REG		16
+#define ALTERA_UART_EOP_REG		20
+
+#define ALTERA_UART_STATUS_PE_MSK	0x0001	/* parity error */
+#define ALTERA_UART_STATUS_FE_MSK	0x0002	/* framing error */
+#define ALTERA_UART_STATUS_BRK_MSK	0x0004	/* break */
+#define ALTERA_UART_STATUS_ROE_MSK	0x0008	/* RX overrun error */
+#define ALTERA_UART_STATUS_TOE_MSK	0x0010	/* TX overrun error */
+#define ALTERA_UART_STATUS_TMT_MSK	0x0020	/* TX shift register state */
+#define ALTERA_UART_STATUS_TRDY_MSK	0x0040	/* TX ready */
+#define ALTERA_UART_STATUS_RRDY_MSK	0x0080	/* RX ready */
+#define ALTERA_UART_STATUS_E_MSK	0x0100	/* exception condition */
+#define ALTERA_UART_STATUS_DCTS_MSK	0x0400	/* CTS logic-level change */
+#define ALTERA_UART_STATUS_CTS_MSK	0x0800	/* CTS logic state */
+#define ALTERA_UART_STATUS_EOP_MSK	0x1000	/* EOP written/read */
+
+						/* Enable interrupt on... */
+#define ALTERA_UART_CONTROL_PE_MSK	0x0001	/* ...parity error */
+#define ALTERA_UART_CONTROL_FE_MSK	0x0002	/* ...framing error */
+#define ALTERA_UART_CONTROL_BRK_MSK	0x0004	/* ...break */
+#define ALTERA_UART_CONTROL_ROE_MSK	0x0008	/* ...RX overrun */
+#define ALTERA_UART_CONTROL_TOE_MSK	0x0010	/* ...TX overrun */
+#define ALTERA_UART_CONTROL_TMT_MSK	0x0020	/* ...TX shift register empty */
+#define ALTERA_UART_CONTROL_TRDY_MSK	0x0040	/* ...TX ready */
+#define ALTERA_UART_CONTROL_RRDY_MSK	0x0080	/* ...RX ready */
+#define ALTERA_UART_CONTROL_E_MSK	0x0100	/* ...exception*/
+
+#define ALTERA_UART_CONTROL_TRBK_MSK	0x0200	/* TX break */
+#define ALTERA_UART_CONTROL_DCTS_MSK	0x0400	/* Interrupt on CTS change */
+#define ALTERA_UART_CONTROL_RTS_MSK	0x0800	/* RTS signal */
+#define ALTERA_UART_CONTROL_EOP_MSK	0x1000	/* Interrupt on EOP */
+
+/*
+ * Local per-uart structure.
+ */
+struct altera_uart {
+	struct uart_port port;
+	struct timer_list tmr;
+	unsigned int sigs;	/* Local copy of line sigs */
+	unsigned short imr;	/* Local IMR mirror */
+};
+
+static u32 altera_uart_readl(struct uart_port *port, int reg)
+{
+	return readl(port->membase + (reg << port->regshift));
+}
+
+static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
+{
+	writel(dat, port->membase + (reg << port->regshift));
+}
+
+static unsigned int altera_uart_tx_empty(struct uart_port *port)
+{
+	return (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int altera_uart_get_mctrl(struct uart_port *port)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+	unsigned int sigs;
+
+	sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+	     ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
+	sigs |= (pp->sigs & TIOCM_RTS);
+
+	return sigs;
+}
+
+static void altera_uart_update_ctrl_reg(struct altera_uart *pp)
+{
+	unsigned short imr = pp->imr;
+
+	/*
+	 * If the device doesn't have an irq, ensure that the irq bits are
+	 * masked out to keep the irq line inactive.
+	 */
+	if (!pp->port.irq)
+		imr &= ALTERA_UART_CONTROL_TRBK_MSK | ALTERA_UART_CONTROL_RTS_MSK;
+
+	altera_uart_writel(&pp->port, imr, ALTERA_UART_CONTROL_REG);
+}
+
+static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+	pp->sigs = sigs;
+	if (sigs & TIOCM_RTS)
+		pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
+	else
+		pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
+	altera_uart_update_ctrl_reg(pp);
+}
+
+static void altera_uart_start_tx(struct uart_port *port)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+	pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
+	altera_uart_update_ctrl_reg(pp);
+}
+
+static void altera_uart_stop_tx(struct uart_port *port)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+	pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
+	altera_uart_update_ctrl_reg(pp);
+}
+
+static void altera_uart_stop_rx(struct uart_port *port)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+	pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
+	altera_uart_update_ctrl_reg(pp);
+}
+
+static void altera_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (break_state == -1)
+		pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
+	else
+		pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
+	altera_uart_update_ctrl_reg(pp);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_set_termios(struct uart_port *port,
+				    struct ktermios *termios,
+				    const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, baudclk;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+	baudclk = port->uartclk / baud;
+
+	if (old)
+		tty_termios_copy_hw(termios, old);
+	tty_termios_encode_baud_rate(termios, baud, baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_update_timeout(port, termios->c_cflag, baud);
+	altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/*
+	 * FIXME: port->read_status_mask and port->ignore_status_mask
+	 * need to be initialized based on termios settings for
+	 * INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
+	 */
+}
+
+static void altera_uart_rx_chars(struct uart_port *port)
+{
+	unsigned short status;
+	u8 ch, flag;
+
+	while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
+	       ALTERA_UART_STATUS_RRDY_MSK) {
+		ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (status & ALTERA_UART_STATUS_E_MSK) {
+			altera_uart_writel(port, status,
+					   ALTERA_UART_STATUS_REG);
+
+			if (status & ALTERA_UART_STATUS_BRK_MSK) {
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			} else if (status & ALTERA_UART_STATUS_PE_MSK) {
+				port->icount.parity++;
+			} else if (status & ALTERA_UART_STATUS_ROE_MSK) {
+				port->icount.overrun++;
+			} else if (status & ALTERA_UART_STATUS_FE_MSK) {
+				port->icount.frame++;
+			}
+
+			status &= port->read_status_mask;
+
+			if (status & ALTERA_UART_STATUS_BRK_MSK)
+				flag = TTY_BREAK;
+			else if (status & ALTERA_UART_STATUS_PE_MSK)
+				flag = TTY_PARITY;
+			else if (status & ALTERA_UART_STATUS_FE_MSK)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+		uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
+				 flag);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void altera_uart_tx_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		                ALTERA_UART_STATUS_TRDY_MSK,
+		altera_uart_writel(port, ch, ALTERA_UART_TXDATA_REG));
+}
+
+static irqreturn_t altera_uart_interrupt(int irq, void *data)
+{
+	struct uart_port *port = data;
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+	unsigned long flags;
+	unsigned int isr;
+
+	isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
+		altera_uart_rx_chars(port);
+	if (isr & ALTERA_UART_STATUS_TRDY_MSK)
+		altera_uart_tx_chars(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_RETVAL(isr);
+}
+
+static void altera_uart_timer(struct timer_list *t)
+{
+	struct altera_uart *pp = from_timer(pp, t, tmr);
+	struct uart_port *port = &pp->port;
+
+	altera_uart_interrupt(0, port);
+	mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
+}
+
+static void altera_uart_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_ALTERA_UART;
+
+	/* Clear mask, so no surprise interrupts. */
+	altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
+	/* Clear status register */
+	altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
+}
+
+static int altera_uart_startup(struct uart_port *port)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+	unsigned long flags;
+
+	if (!port->irq) {
+		timer_setup(&pp->tmr, altera_uart_timer, 0);
+		mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
+	} else {
+		int ret;
+
+		ret = request_irq(port->irq, altera_uart_interrupt, 0,
+				DRV_NAME, port);
+		if (ret) {
+			pr_err(DRV_NAME ": unable to attach Altera UART %d "
+			       "interrupt vector=%d\n", port->line, port->irq);
+			return ret;
+		}
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Enable RX interrupts now */
+	pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
+	altera_uart_update_ctrl_reg(pp);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void altera_uart_shutdown(struct uart_port *port)
+{
+	struct altera_uart *pp = container_of(port, struct altera_uart, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable all interrupts now */
+	pp->imr = 0;
+	altera_uart_update_ctrl_reg(pp);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (port->irq)
+		free_irq(port->irq, port);
+	else
+		del_timer_sync(&pp->tmr);
+}
+
+static const char *altera_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
+}
+
+static int altera_uart_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+static void altera_uart_release_port(struct uart_port *port)
+{
+	/* Nothing to release... */
+}
+
+static int altera_uart_verify_port(struct uart_port *port,
+				   struct serial_struct *ser)
+{
+	if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
+		return -EINVAL;
+	return 0;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int altera_uart_poll_get_char(struct uart_port *port)
+{
+	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		 ALTERA_UART_STATUS_RRDY_MSK))
+		cpu_relax();
+
+	return altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
+}
+
+static void altera_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		 ALTERA_UART_STATUS_TRDY_MSK))
+		cpu_relax();
+
+	altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
+}
+#endif
+
+/*
+ *	Define the basic serial functions we support.
+ */
+static const struct uart_ops altera_uart_ops = {
+	.tx_empty	= altera_uart_tx_empty,
+	.get_mctrl	= altera_uart_get_mctrl,
+	.set_mctrl	= altera_uart_set_mctrl,
+	.start_tx	= altera_uart_start_tx,
+	.stop_tx	= altera_uart_stop_tx,
+	.stop_rx	= altera_uart_stop_rx,
+	.break_ctl	= altera_uart_break_ctl,
+	.startup	= altera_uart_startup,
+	.shutdown	= altera_uart_shutdown,
+	.set_termios	= altera_uart_set_termios,
+	.type		= altera_uart_type,
+	.request_port	= altera_uart_request_port,
+	.release_port	= altera_uart_release_port,
+	.config_port	= altera_uart_config_port,
+	.verify_port	= altera_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= altera_uart_poll_get_char,
+	.poll_put_char	= altera_uart_poll_put_char,
+#endif
+};
+
+static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
+
+#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
+
+static void altera_uart_console_putc(struct uart_port *port, unsigned char c)
+{
+	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		 ALTERA_UART_STATUS_TRDY_MSK))
+		cpu_relax();
+
+	altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
+}
+
+static void altera_uart_console_write(struct console *co, const char *s,
+				      unsigned int count)
+{
+	struct uart_port *port = &(altera_uart_ports + co->index)->port;
+
+	uart_console_write(port, s, count, altera_uart_console_putc);
+}
+
+static int __init altera_uart_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
+		return -EINVAL;
+	port = &altera_uart_ports[co->index].port;
+	if (!port->membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver altera_uart_driver;
+
+static struct console altera_uart_console = {
+	.name	= "ttyAL",
+	.write	= altera_uart_console_write,
+	.device	= uart_console_device,
+	.setup	= altera_uart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &altera_uart_driver,
+};
+
+static int __init altera_uart_console_init(void)
+{
+	register_console(&altera_uart_console);
+	return 0;
+}
+
+console_initcall(altera_uart_console_init);
+
+#define	ALTERA_UART_CONSOLE	(&altera_uart_console)
+
+static void altera_uart_earlycon_write(struct console *co, const char *s,
+				       unsigned int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	uart_console_write(&dev->port, s, count, altera_uart_console_putc);
+}
+
+static int __init altera_uart_earlycon_setup(struct earlycon_device *dev,
+					     const char *options)
+{
+	struct uart_port *port = &dev->port;
+
+	if (!port->membase)
+		return -ENODEV;
+
+	/* Enable RX interrupts now */
+	altera_uart_writel(port, ALTERA_UART_CONTROL_RRDY_MSK,
+			   ALTERA_UART_CONTROL_REG);
+
+	if (dev->baud) {
+		unsigned int baudclk = port->uartclk / dev->baud;
+
+		altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
+	}
+
+	dev->con->write = altera_uart_earlycon_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(uart, "altr,uart-1.0", altera_uart_earlycon_setup);
+
+#else
+
+#define	ALTERA_UART_CONSOLE	NULL
+
+#endif /* CONFIG_SERIAL_ALTERA_UART_CONSOLE */
+
+/*
+ *	Define the altera_uart UART driver structure.
+ */
+static struct uart_driver altera_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRV_NAME,
+	.dev_name	= "ttyAL",
+	.major		= SERIAL_ALTERA_MAJOR,
+	.minor		= SERIAL_ALTERA_MINOR,
+	.nr		= CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
+	.cons		= ALTERA_UART_CONSOLE,
+};
+
+static int altera_uart_probe(struct platform_device *pdev)
+{
+	struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
+	struct uart_port *port;
+	struct resource *res_mem;
+	int i = pdev->id;
+	int ret;
+
+	/* if id is -1 scan for a free id and use that one */
+	if (i == -1) {
+		for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++)
+			if (altera_uart_ports[i].port.mapbase == 0)
+				break;
+	}
+
+	if (i < 0 || i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
+		return -EINVAL;
+
+	port = &altera_uart_ports[i].port;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res_mem)
+		port->mapbase = res_mem->start;
+	else if (platp)
+		port->mapbase = platp->mapbase;
+	else
+		return -EINVAL;
+
+	ret = platform_get_irq_optional(pdev, 0);
+	if (ret < 0 && ret != -ENXIO)
+		return ret;
+	if (ret > 0)
+		port->irq = ret;
+	else if (platp)
+		port->irq = platp->irq;
+
+	/* Check platform data first so we can override device node data */
+	if (platp)
+		port->uartclk = platp->uartclk;
+	else {
+		ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+					   &port->uartclk);
+		if (ret)
+			return ret;
+	}
+
+	port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
+	if (!port->membase)
+		return -ENOMEM;
+
+	if (platp)
+		port->regshift = platp->bus_shift;
+	else
+		port->regshift = 0;
+
+	port->line = i;
+	port->type = PORT_ALTERA_UART;
+	port->iotype = SERIAL_IO_MEM;
+	port->ops = &altera_uart_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
+
+	platform_set_drvdata(pdev, port);
+
+	uart_add_one_port(&altera_uart_driver, port);
+
+	return 0;
+}
+
+static int altera_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	if (port) {
+		uart_remove_one_port(&altera_uart_driver, port);
+		port->mapbase = 0;
+		iounmap(port->membase);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id altera_uart_match[] = {
+	{ .compatible = "ALTR,uart-1.0", },
+	{ .compatible = "altr,uart-1.0", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, altera_uart_match);
+#endif /* CONFIG_OF */
+
+static struct platform_driver altera_uart_platform_driver = {
+	.probe	= altera_uart_probe,
+	.remove	= altera_uart_remove,
+	.driver	= {
+		.name		= DRV_NAME,
+		.of_match_table	= of_match_ptr(altera_uart_match),
+	},
+};
+
+static int __init altera_uart_init(void)
+{
+	int rc;
+
+	rc = uart_register_driver(&altera_uart_driver);
+	if (rc)
+		return rc;
+	rc = platform_driver_register(&altera_uart_platform_driver);
+	if (rc)
+		uart_unregister_driver(&altera_uart_driver);
+	return rc;
+}
+
+static void __exit altera_uart_exit(void)
+{
+	platform_driver_unregister(&altera_uart_platform_driver);
+	uart_unregister_driver(&altera_uart_driver);
+}
+
+module_init(altera_uart_init);
+module_exit(altera_uart_exit);
+
+MODULE_DESCRIPTION("Altera UART driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_ALTERA_MAJOR);
diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
new file mode 100644
index 000000000..b5a7404cb
--- /dev/null
+++ b/drivers/tty/serial/amba-pl010.c
@@ -0,0 +1,804 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for AMBA serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright 1999 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ *
+ * This is a generic driver for ARM AMBA-type serial ports.  They
+ * have a lot of 16550-like features, but are not register compatible.
+ * Note that although they do have CTS, DCD and DSR inputs, they do
+ * not have an RI input, nor do they have DTR or RTS outputs.  If
+ * required, these have to be supplied via some other means (eg, GPIO)
+ * and hooked into this driver.
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/amba/bus.h>
+#include <linux/amba/serial.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#define UART_NR		8
+
+#define SERIAL_AMBA_MAJOR	204
+#define SERIAL_AMBA_MINOR	16
+#define SERIAL_AMBA_NR		UART_NR
+
+#define AMBA_ISR_PASS_LIMIT	256
+
+#define UART_RX_DATA(s)		(((s) & UART01x_FR_RXFE) == 0)
+#define UART_TX_READY(s)	(((s) & UART01x_FR_TXFF) == 0)
+
+#define UART_DUMMY_RSR_RX	256
+#define UART_PORT_SIZE		64
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_amba_port {
+	struct uart_port	port;
+	struct clk		*clk;
+	struct amba_device	*dev;
+	struct amba_pl010_data	*data;
+	unsigned int		old_status;
+};
+
+static void pl010_stop_tx(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+	unsigned int cr;
+
+	cr = readb(uap->port.membase + UART010_CR);
+	cr &= ~UART010_CR_TIE;
+	writel(cr, uap->port.membase + UART010_CR);
+}
+
+static void pl010_start_tx(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+	unsigned int cr;
+
+	cr = readb(uap->port.membase + UART010_CR);
+	cr |= UART010_CR_TIE;
+	writel(cr, uap->port.membase + UART010_CR);
+}
+
+static void pl010_stop_rx(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+	unsigned int cr;
+
+	cr = readb(uap->port.membase + UART010_CR);
+	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
+	writel(cr, uap->port.membase + UART010_CR);
+}
+
+static void pl010_disable_ms(struct uart_port *port)
+{
+	struct uart_amba_port *uap = (struct uart_amba_port *)port;
+	unsigned int cr;
+
+	cr = readb(uap->port.membase + UART010_CR);
+	cr &= ~UART010_CR_MSIE;
+	writel(cr, uap->port.membase + UART010_CR);
+}
+
+static void pl010_enable_ms(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+	unsigned int cr;
+
+	cr = readb(uap->port.membase + UART010_CR);
+	cr |= UART010_CR_MSIE;
+	writel(cr, uap->port.membase + UART010_CR);
+}
+
+static void pl010_rx_chars(struct uart_port *port)
+{
+	unsigned int status, rsr, max_count = 256;
+	u8 ch, flag;
+
+	status = readb(port->membase + UART01x_FR);
+	while (UART_RX_DATA(status) && max_count--) {
+		ch = readb(port->membase + UART01x_DR);
+		flag = TTY_NORMAL;
+
+		port->icount.rx++;
+
+		/*
+		 * Note that the error handling code is
+		 * out of the main execution path
+		 */
+		rsr = readb(port->membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
+		if (unlikely(rsr & UART01x_RSR_ANY)) {
+			writel(0, port->membase + UART01x_ECR);
+
+			if (rsr & UART01x_RSR_BE) {
+				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					goto ignore_char;
+			} else if (rsr & UART01x_RSR_PE)
+				port->icount.parity++;
+			else if (rsr & UART01x_RSR_FE)
+				port->icount.frame++;
+			if (rsr & UART01x_RSR_OE)
+				port->icount.overrun++;
+
+			rsr &= port->read_status_mask;
+
+			if (rsr & UART01x_RSR_BE)
+				flag = TTY_BREAK;
+			else if (rsr & UART01x_RSR_PE)
+				flag = TTY_PARITY;
+			else if (rsr & UART01x_RSR_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			goto ignore_char;
+
+		uart_insert_char(port, rsr, UART01x_RSR_OE, ch, flag);
+
+	ignore_char:
+		status = readb(port->membase + UART01x_FR);
+	}
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void pl010_tx_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx_limited(port, ch, port->fifosize >> 1,
+		true,
+		writel(ch, port->membase + UART01x_DR),
+		({}));
+}
+
+static void pl010_modem_status(struct uart_amba_port *uap)
+{
+	struct uart_port *port = &uap->port;
+	unsigned int status, delta;
+
+	writel(0, port->membase + UART010_ICR);
+
+	status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
+
+	delta = status ^ uap->old_status;
+	uap->old_status = status;
+
+	if (!delta)
+		return;
+
+	if (delta & UART01x_FR_DCD)
+		uart_handle_dcd_change(port, status & UART01x_FR_DCD);
+
+	if (delta & UART01x_FR_DSR)
+		port->icount.dsr++;
+
+	if (delta & UART01x_FR_CTS)
+		uart_handle_cts_change(port, status & UART01x_FR_CTS);
+
+	wake_up_interruptible(&port->state->port.delta_msr_wait);
+}
+
+static irqreturn_t pl010_int(int irq, void *dev_id)
+{
+	struct uart_amba_port *uap = dev_id;
+	struct uart_port *port = &uap->port;
+	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
+	int handled = 0;
+
+	spin_lock(&port->lock);
+
+	status = readb(port->membase + UART010_IIR);
+	if (status) {
+		do {
+			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
+				pl010_rx_chars(port);
+			if (status & UART010_IIR_MIS)
+				pl010_modem_status(uap);
+			if (status & UART010_IIR_TIS)
+				pl010_tx_chars(port);
+
+			if (pass_counter-- == 0)
+				break;
+
+			status = readb(port->membase + UART010_IIR);
+		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
+				   UART010_IIR_TIS));
+		handled = 1;
+	}
+
+	spin_unlock(&port->lock);
+
+	return IRQ_RETVAL(handled);
+}
+
+static unsigned int pl010_tx_empty(struct uart_port *port)
+{
+	unsigned int status = readb(port->membase + UART01x_FR);
+
+	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int pl010_get_mctrl(struct uart_port *port)
+{
+	unsigned int result = 0;
+	unsigned int status;
+
+	status = readb(port->membase + UART01x_FR);
+	if (status & UART01x_FR_DCD)
+		result |= TIOCM_CAR;
+	if (status & UART01x_FR_DSR)
+		result |= TIOCM_DSR;
+	if (status & UART01x_FR_CTS)
+		result |= TIOCM_CTS;
+
+	return result;
+}
+
+static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+
+	if (uap->data)
+		uap->data->set_mctrl(uap->dev, port->membase, mctrl);
+}
+
+static void pl010_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+	unsigned int lcr_h;
+
+	spin_lock_irqsave(&port->lock, flags);
+	lcr_h = readb(port->membase + UART010_LCRH);
+	if (break_state == -1)
+		lcr_h |= UART01x_LCRH_BRK;
+	else
+		lcr_h &= ~UART01x_LCRH_BRK;
+	writel(lcr_h, port->membase + UART010_LCRH);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int pl010_startup(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+	int retval;
+
+	/*
+	 * Try to enable the clock producer.
+	 */
+	retval = clk_prepare_enable(uap->clk);
+	if (retval)
+		goto out;
+
+	port->uartclk = clk_get_rate(uap->clk);
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(port->irq, pl010_int, 0, "uart-pl010", uap);
+	if (retval)
+		goto clk_dis;
+
+	/*
+	 * initialise the old status of the modem signals
+	 */
+	uap->old_status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
+	       port->membase + UART010_CR);
+
+	return 0;
+
+ clk_dis:
+	clk_disable_unprepare(uap->clk);
+ out:
+	return retval;
+}
+
+static void pl010_shutdown(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+
+	/*
+	 * Free the interrupt
+	 */
+	free_irq(port->irq, uap);
+
+	/*
+	 * disable all interrupts, disable the port
+	 */
+	writel(0, port->membase + UART010_CR);
+
+	/* disable break condition and fifos */
+	writel(readb(port->membase + UART010_LCRH) &
+		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
+	       port->membase + UART010_LCRH);
+
+	/*
+	 * Shut down the clock producer
+	 */
+	clk_disable_unprepare(uap->clk);
+}
+
+static void
+pl010_set_termios(struct uart_port *port, struct ktermios *termios,
+		  const struct ktermios *old)
+{
+	unsigned int lcr_h, old_cr;
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+	quot = uart_get_divisor(port, baud);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr_h = UART01x_LCRH_WLEN_5;
+		break;
+	case CS6:
+		lcr_h = UART01x_LCRH_WLEN_6;
+		break;
+	case CS7:
+		lcr_h = UART01x_LCRH_WLEN_7;
+		break;
+	default: // CS8
+		lcr_h = UART01x_LCRH_WLEN_8;
+		break;
+	}
+	if (termios->c_cflag & CSTOPB)
+		lcr_h |= UART01x_LCRH_STP2;
+	if (termios->c_cflag & PARENB) {
+		lcr_h |= UART01x_LCRH_PEN;
+		if (!(termios->c_cflag & PARODD))
+			lcr_h |= UART01x_LCRH_EPS;
+	}
+	if (port->fifosize > 1)
+		lcr_h |= UART01x_LCRH_FEN;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = UART01x_RSR_OE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= UART01x_RSR_BE;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= UART01x_RSR_BE;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= UART01x_RSR_OE;
+	}
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_DUMMY_RSR_RX;
+
+	old_cr = readb(port->membase + UART010_CR) & ~UART010_CR_MSIE;
+
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		old_cr |= UART010_CR_MSIE;
+
+	/* Set baud rate */
+	quot -= 1;
+	writel((quot & 0xf00) >> 8, port->membase + UART010_LCRM);
+	writel(quot & 0xff, port->membase + UART010_LCRL);
+
+	/*
+	 * ----------v----------v----------v----------v-----
+	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
+	 * ----------^----------^----------^----------^-----
+	 */
+	writel(lcr_h, port->membase + UART010_LCRH);
+	writel(old_cr, port->membase + UART010_CR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	if (termios->c_line == N_PPS) {
+		port->flags |= UPF_HARDPPS_CD;
+		spin_lock_irq(&port->lock);
+		pl010_enable_ms(port);
+		spin_unlock_irq(&port->lock);
+	} else {
+		port->flags &= ~UPF_HARDPPS_CD;
+		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
+			spin_lock_irq(&port->lock);
+			pl010_disable_ms(port);
+			spin_unlock_irq(&port->lock);
+		}
+	}
+}
+
+static const char *pl010_type(struct uart_port *port)
+{
+	return port->type == PORT_AMBA ? "AMBA" : NULL;
+}
+
+/*
+ * Release the memory region(s) being used by 'port'
+ */
+static void pl010_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, UART_PORT_SIZE);
+}
+
+/*
+ * Request the memory region(s) being used by 'port'
+ */
+static int pl010_request_port(struct uart_port *port)
+{
+	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
+			!= NULL ? 0 : -EBUSY;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void pl010_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_AMBA;
+		pl010_request_port(port);
+	}
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
+		ret = -EINVAL;
+	if (ser->irq < 0 || ser->irq >= nr_irqs)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops amba_pl010_pops = {
+	.tx_empty	= pl010_tx_empty,
+	.set_mctrl	= pl010_set_mctrl,
+	.get_mctrl	= pl010_get_mctrl,
+	.stop_tx	= pl010_stop_tx,
+	.start_tx	= pl010_start_tx,
+	.stop_rx	= pl010_stop_rx,
+	.enable_ms	= pl010_enable_ms,
+	.break_ctl	= pl010_break_ctl,
+	.startup	= pl010_startup,
+	.shutdown	= pl010_shutdown,
+	.set_termios	= pl010_set_termios,
+	.set_ldisc	= pl010_set_ldisc,
+	.type		= pl010_type,
+	.release_port	= pl010_release_port,
+	.request_port	= pl010_request_port,
+	.config_port	= pl010_config_port,
+	.verify_port	= pl010_verify_port,
+};
+
+static struct uart_amba_port *amba_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
+
+static void pl010_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned int status;
+
+	do {
+		status = readb(port->membase + UART01x_FR);
+		barrier();
+	} while (!UART_TX_READY(status));
+	writel(ch, port->membase + UART01x_DR);
+}
+
+static void
+pl010_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_amba_port *uap = amba_ports[co->index];
+	struct uart_port *port = &uap->port;
+	unsigned int status, old_cr;
+
+	clk_enable(uap->clk);
+
+	/*
+	 *	First save the CR then disable the interrupts
+	 */
+	old_cr = readb(port->membase + UART010_CR);
+	writel(UART01x_CR_UARTEN, port->membase + UART010_CR);
+
+	uart_console_write(port, s, count, pl010_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the TCR
+	 */
+	do {
+		status = readb(port->membase + UART01x_FR);
+		barrier();
+	} while (status & UART01x_FR_BUSY);
+	writel(old_cr, port->membase + UART010_CR);
+
+	clk_disable(uap->clk);
+}
+
+static void __init
+pl010_console_get_options(struct uart_amba_port *uap, int *baud,
+			     int *parity, int *bits)
+{
+	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
+		unsigned int lcr_h, quot;
+		lcr_h = readb(uap->port.membase + UART010_LCRH);
+
+		*parity = 'n';
+		if (lcr_h & UART01x_LCRH_PEN) {
+			if (lcr_h & UART01x_LCRH_EPS)
+				*parity = 'e';
+			else
+				*parity = 'o';
+		}
+
+		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
+			*bits = 7;
+		else
+			*bits = 8;
+
+		quot = readb(uap->port.membase + UART010_LCRL) |
+		       readb(uap->port.membase + UART010_LCRM) << 8;
+		*baud = uap->port.uartclk / (16 * (quot + 1));
+	}
+}
+
+static int __init pl010_console_setup(struct console *co, char *options)
+{
+	struct uart_amba_port *uap;
+	int baud = 38400;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= UART_NR)
+		co->index = 0;
+	uap = amba_ports[co->index];
+	if (!uap)
+		return -ENODEV;
+
+	ret = clk_prepare(uap->clk);
+	if (ret)
+		return ret;
+
+	uap->port.uartclk = clk_get_rate(uap->clk);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		pl010_console_get_options(uap, &baud, &parity, &bits);
+
+	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver amba_reg;
+static struct console amba_console = {
+	.name		= "ttyAM",
+	.write		= pl010_console_write,
+	.device		= uart_console_device,
+	.setup		= pl010_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &amba_reg,
+};
+
+#define AMBA_CONSOLE	&amba_console
+#else
+#define AMBA_CONSOLE	NULL
+#endif
+
+static DEFINE_MUTEX(amba_reg_lock);
+static struct uart_driver amba_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "ttyAM",
+	.dev_name		= "ttyAM",
+	.major			= SERIAL_AMBA_MAJOR,
+	.minor			= SERIAL_AMBA_MINOR,
+	.nr			= UART_NR,
+	.cons			= AMBA_CONSOLE,
+};
+
+static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
+{
+	struct uart_amba_port *uap;
+	void __iomem *base;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+		if (amba_ports[i] == NULL)
+			break;
+
+	if (i == ARRAY_SIZE(amba_ports))
+		return -EBUSY;
+
+	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
+			   GFP_KERNEL);
+	if (!uap)
+		return -ENOMEM;
+
+	base = devm_ioremap(&dev->dev, dev->res.start,
+			    resource_size(&dev->res));
+	if (!base)
+		return -ENOMEM;
+
+	uap->clk = devm_clk_get(&dev->dev, NULL);
+	if (IS_ERR(uap->clk))
+		return PTR_ERR(uap->clk);
+
+	uap->port.dev = &dev->dev;
+	uap->port.mapbase = dev->res.start;
+	uap->port.membase = base;
+	uap->port.iotype = UPIO_MEM;
+	uap->port.irq = dev->irq[0];
+	uap->port.fifosize = 16;
+	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
+	uap->port.ops = &amba_pl010_pops;
+	uap->port.flags = UPF_BOOT_AUTOCONF;
+	uap->port.line = i;
+	uap->dev = dev;
+	uap->data = dev_get_platdata(&dev->dev);
+
+	amba_ports[i] = uap;
+
+	amba_set_drvdata(dev, uap);
+
+	mutex_lock(&amba_reg_lock);
+	if (!amba_reg.state) {
+		ret = uart_register_driver(&amba_reg);
+		if (ret < 0) {
+			mutex_unlock(&amba_reg_lock);
+			dev_err(uap->port.dev,
+				"Failed to register AMBA-PL010 driver\n");
+			return ret;
+		}
+	}
+	mutex_unlock(&amba_reg_lock);
+
+	ret = uart_add_one_port(&amba_reg, &uap->port);
+	if (ret)
+		amba_ports[i] = NULL;
+
+	return ret;
+}
+
+static void pl010_remove(struct amba_device *dev)
+{
+	struct uart_amba_port *uap = amba_get_drvdata(dev);
+	int i;
+	bool busy = false;
+
+	uart_remove_one_port(&amba_reg, &uap->port);
+
+	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+		if (amba_ports[i] == uap)
+			amba_ports[i] = NULL;
+		else if (amba_ports[i])
+			busy = true;
+
+	if (!busy)
+		uart_unregister_driver(&amba_reg);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pl010_suspend(struct device *dev)
+{
+	struct uart_amba_port *uap = dev_get_drvdata(dev);
+
+	if (uap)
+		uart_suspend_port(&amba_reg, &uap->port);
+
+	return 0;
+}
+
+static int pl010_resume(struct device *dev)
+{
+	struct uart_amba_port *uap = dev_get_drvdata(dev);
+
+	if (uap)
+		uart_resume_port(&amba_reg, &uap->port);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
+
+static const struct amba_id pl010_ids[] = {
+	{
+		.id	= 0x00041010,
+		.mask	= 0x000fffff,
+	},
+	{ 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl010_ids);
+
+static struct amba_driver pl010_driver = {
+	.drv = {
+		.name	= "uart-pl010",
+		.pm	= &pl010_dev_pm_ops,
+	},
+	.id_table	= pl010_ids,
+	.probe		= pl010_probe,
+	.remove		= pl010_remove,
+};
+
+static int __init pl010_init(void)
+{
+	printk(KERN_INFO "Serial: AMBA driver\n");
+
+	return  amba_driver_register(&pl010_driver);
+}
+
+static void __exit pl010_exit(void)
+{
+	amba_driver_unregister(&pl010_driver);
+}
+
+module_init(pl010_init);
+module_exit(pl010_exit);
+
+MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
+MODULE_DESCRIPTION("ARM AMBA serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
new file mode 100644
index 000000000..cd3913b93
--- /dev/null
+++ b/drivers/tty/serial/amba-pl011.c
@@ -0,0 +1,3023 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for AMBA serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright 1999 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ *  Copyright (C) 2010 ST-Ericsson SA
+ *
+ * This is a generic driver for ARM AMBA-type serial ports.  They
+ * have a lot of 16550-like features, but are not register compatible.
+ * Note that although they do have CTS, DCD and DSR inputs, they do
+ * not have an RI input, nor do they have DTR or RTS outputs.  If
+ * required, these have to be supplied via some other means (eg, GPIO)
+ * and hooked into this driver.
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/platform_device.h>
+#include <linux/sysrq.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/amba/bus.h>
+#include <linux/amba/serial.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/sizes.h>
+#include <linux/io.h>
+#include <linux/acpi.h>
+
+#define UART_NR			14
+
+#define SERIAL_AMBA_MAJOR	204
+#define SERIAL_AMBA_MINOR	64
+#define SERIAL_AMBA_NR		UART_NR
+
+#define AMBA_ISR_PASS_LIMIT	256
+
+#define UART_DR_ERROR		(UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
+#define UART_DUMMY_DR_RX	(1 << 16)
+
+enum {
+	REG_DR,
+	REG_ST_DMAWM,
+	REG_ST_TIMEOUT,
+	REG_FR,
+	REG_LCRH_RX,
+	REG_LCRH_TX,
+	REG_IBRD,
+	REG_FBRD,
+	REG_CR,
+	REG_IFLS,
+	REG_IMSC,
+	REG_RIS,
+	REG_MIS,
+	REG_ICR,
+	REG_DMACR,
+	REG_ST_XFCR,
+	REG_ST_XON1,
+	REG_ST_XON2,
+	REG_ST_XOFF1,
+	REG_ST_XOFF2,
+	REG_ST_ITCR,
+	REG_ST_ITIP,
+	REG_ST_ABCR,
+	REG_ST_ABIMSC,
+
+	/* The size of the array - must be last */
+	REG_ARRAY_SIZE,
+};
+
+static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
+	[REG_DR] = UART01x_DR,
+	[REG_FR] = UART01x_FR,
+	[REG_LCRH_RX] = UART011_LCRH,
+	[REG_LCRH_TX] = UART011_LCRH,
+	[REG_IBRD] = UART011_IBRD,
+	[REG_FBRD] = UART011_FBRD,
+	[REG_CR] = UART011_CR,
+	[REG_IFLS] = UART011_IFLS,
+	[REG_IMSC] = UART011_IMSC,
+	[REG_RIS] = UART011_RIS,
+	[REG_MIS] = UART011_MIS,
+	[REG_ICR] = UART011_ICR,
+	[REG_DMACR] = UART011_DMACR,
+};
+
+/* There is by now at least one vendor with differing details, so handle it */
+struct vendor_data {
+	const u16		*reg_offset;
+	unsigned int		ifls;
+	unsigned int		fr_busy;
+	unsigned int		fr_dsr;
+	unsigned int		fr_cts;
+	unsigned int		fr_ri;
+	unsigned int		inv_fr;
+	bool			access_32b;
+	bool			oversampling;
+	bool			dma_threshold;
+	bool			cts_event_workaround;
+	bool			always_enabled;
+	bool			fixed_options;
+
+	unsigned int (*get_fifosize)(struct amba_device *dev);
+};
+
+static unsigned int get_fifosize_arm(struct amba_device *dev)
+{
+	return amba_rev(dev) < 3 ? 16 : 32;
+}
+
+static struct vendor_data vendor_arm = {
+	.reg_offset		= pl011_std_offsets,
+	.ifls			= UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
+	.fr_busy		= UART01x_FR_BUSY,
+	.fr_dsr			= UART01x_FR_DSR,
+	.fr_cts			= UART01x_FR_CTS,
+	.fr_ri			= UART011_FR_RI,
+	.oversampling		= false,
+	.dma_threshold		= false,
+	.cts_event_workaround	= false,
+	.always_enabled		= false,
+	.fixed_options		= false,
+	.get_fifosize		= get_fifosize_arm,
+};
+
+static const struct vendor_data vendor_sbsa = {
+	.reg_offset		= pl011_std_offsets,
+	.fr_busy		= UART01x_FR_BUSY,
+	.fr_dsr			= UART01x_FR_DSR,
+	.fr_cts			= UART01x_FR_CTS,
+	.fr_ri			= UART011_FR_RI,
+	.access_32b		= true,
+	.oversampling		= false,
+	.dma_threshold		= false,
+	.cts_event_workaround	= false,
+	.always_enabled		= true,
+	.fixed_options		= true,
+};
+
+#ifdef CONFIG_ACPI_SPCR_TABLE
+static const struct vendor_data vendor_qdt_qdf2400_e44 = {
+	.reg_offset		= pl011_std_offsets,
+	.fr_busy		= UART011_FR_TXFE,
+	.fr_dsr			= UART01x_FR_DSR,
+	.fr_cts			= UART01x_FR_CTS,
+	.fr_ri			= UART011_FR_RI,
+	.inv_fr			= UART011_FR_TXFE,
+	.access_32b		= true,
+	.oversampling		= false,
+	.dma_threshold		= false,
+	.cts_event_workaround	= false,
+	.always_enabled		= true,
+	.fixed_options		= true,
+};
+#endif
+
+static u16 pl011_st_offsets[REG_ARRAY_SIZE] = {
+	[REG_DR] = UART01x_DR,
+	[REG_ST_DMAWM] = ST_UART011_DMAWM,
+	[REG_ST_TIMEOUT] = ST_UART011_TIMEOUT,
+	[REG_FR] = UART01x_FR,
+	[REG_LCRH_RX] = ST_UART011_LCRH_RX,
+	[REG_LCRH_TX] = ST_UART011_LCRH_TX,
+	[REG_IBRD] = UART011_IBRD,
+	[REG_FBRD] = UART011_FBRD,
+	[REG_CR] = UART011_CR,
+	[REG_IFLS] = UART011_IFLS,
+	[REG_IMSC] = UART011_IMSC,
+	[REG_RIS] = UART011_RIS,
+	[REG_MIS] = UART011_MIS,
+	[REG_ICR] = UART011_ICR,
+	[REG_DMACR] = UART011_DMACR,
+	[REG_ST_XFCR] = ST_UART011_XFCR,
+	[REG_ST_XON1] = ST_UART011_XON1,
+	[REG_ST_XON2] = ST_UART011_XON2,
+	[REG_ST_XOFF1] = ST_UART011_XOFF1,
+	[REG_ST_XOFF2] = ST_UART011_XOFF2,
+	[REG_ST_ITCR] = ST_UART011_ITCR,
+	[REG_ST_ITIP] = ST_UART011_ITIP,
+	[REG_ST_ABCR] = ST_UART011_ABCR,
+	[REG_ST_ABIMSC] = ST_UART011_ABIMSC,
+};
+
+static unsigned int get_fifosize_st(struct amba_device *dev)
+{
+	return 64;
+}
+
+static struct vendor_data vendor_st = {
+	.reg_offset		= pl011_st_offsets,
+	.ifls			= UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
+	.fr_busy		= UART01x_FR_BUSY,
+	.fr_dsr			= UART01x_FR_DSR,
+	.fr_cts			= UART01x_FR_CTS,
+	.fr_ri			= UART011_FR_RI,
+	.oversampling		= true,
+	.dma_threshold		= true,
+	.cts_event_workaround	= true,
+	.always_enabled		= false,
+	.fixed_options		= false,
+	.get_fifosize		= get_fifosize_st,
+};
+
+/* Deals with DMA transactions */
+
+struct pl011_dmabuf {
+	dma_addr_t		dma;
+	size_t			len;
+	char			*buf;
+};
+
+struct pl011_dmarx_data {
+	struct dma_chan		*chan;
+	struct completion	complete;
+	bool			use_buf_b;
+	struct pl011_dmabuf	dbuf_a;
+	struct pl011_dmabuf	dbuf_b;
+	dma_cookie_t		cookie;
+	bool			running;
+	struct timer_list	timer;
+	unsigned int last_residue;
+	unsigned long last_jiffies;
+	bool auto_poll_rate;
+	unsigned int poll_rate;
+	unsigned int poll_timeout;
+};
+
+struct pl011_dmatx_data {
+	struct dma_chan		*chan;
+	dma_addr_t		dma;
+	size_t			len;
+	char			*buf;
+	bool			queued;
+};
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_amba_port {
+	struct uart_port	port;
+	const u16		*reg_offset;
+	struct clk		*clk;
+	const struct vendor_data *vendor;
+	unsigned int		dmacr;		/* dma control reg */
+	unsigned int		im;		/* interrupt mask */
+	unsigned int		old_status;
+	unsigned int		fifosize;	/* vendor-specific */
+	unsigned int		fixed_baud;	/* vendor-set fixed baud rate */
+	char			type[12];
+	bool			rs485_tx_started;
+	unsigned int		rs485_tx_drain_interval; /* usecs */
+#ifdef CONFIG_DMA_ENGINE
+	/* DMA stuff */
+	bool			using_tx_dma;
+	bool			using_rx_dma;
+	struct pl011_dmarx_data dmarx;
+	struct pl011_dmatx_data	dmatx;
+	bool			dma_probed;
+#endif
+};
+
+static unsigned int pl011_tx_empty(struct uart_port *port);
+
+static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap,
+	unsigned int reg)
+{
+	return uap->reg_offset[reg];
+}
+
+static unsigned int pl011_read(const struct uart_amba_port *uap,
+	unsigned int reg)
+{
+	void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
+
+	return (uap->port.iotype == UPIO_MEM32) ?
+		readl_relaxed(addr) : readw_relaxed(addr);
+}
+
+static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
+	unsigned int reg)
+{
+	void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
+
+	if (uap->port.iotype == UPIO_MEM32)
+		writel_relaxed(val, addr);
+	else
+		writew_relaxed(val, addr);
+}
+
+/*
+ * Reads up to 256 characters from the FIFO or until it's empty and
+ * inserts them into the TTY layer. Returns the number of characters
+ * read from the FIFO.
+ */
+static int pl011_fifo_to_tty(struct uart_amba_port *uap)
+{
+	unsigned int ch, fifotaken;
+	int sysrq;
+	u16 status;
+	u8 flag;
+
+	for (fifotaken = 0; fifotaken != 256; fifotaken++) {
+		status = pl011_read(uap, REG_FR);
+		if (status & UART01x_FR_RXFE)
+			break;
+
+		/* Take chars from the FIFO and update status */
+		ch = pl011_read(uap, REG_DR) | UART_DUMMY_DR_RX;
+		flag = TTY_NORMAL;
+		uap->port.icount.rx++;
+
+		if (unlikely(ch & UART_DR_ERROR)) {
+			if (ch & UART011_DR_BE) {
+				ch &= ~(UART011_DR_FE | UART011_DR_PE);
+				uap->port.icount.brk++;
+				if (uart_handle_break(&uap->port))
+					continue;
+			} else if (ch & UART011_DR_PE)
+				uap->port.icount.parity++;
+			else if (ch & UART011_DR_FE)
+				uap->port.icount.frame++;
+			if (ch & UART011_DR_OE)
+				uap->port.icount.overrun++;
+
+			ch &= uap->port.read_status_mask;
+
+			if (ch & UART011_DR_BE)
+				flag = TTY_BREAK;
+			else if (ch & UART011_DR_PE)
+				flag = TTY_PARITY;
+			else if (ch & UART011_DR_FE)
+				flag = TTY_FRAME;
+		}
+
+		spin_unlock(&uap->port.lock);
+		sysrq = uart_handle_sysrq_char(&uap->port, ch & 255);
+		spin_lock(&uap->port.lock);
+
+		if (!sysrq)
+			uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
+	}
+
+	return fifotaken;
+}
+
+
+/*
+ * All the DMA operation mode stuff goes inside this ifdef.
+ * This assumes that you have a generic DMA device interface,
+ * no custom DMA interfaces are supported.
+ */
+#ifdef CONFIG_DMA_ENGINE
+
+#define PL011_DMA_BUFFER_SIZE PAGE_SIZE
+
+static int pl011_dmabuf_init(struct dma_chan *chan, struct pl011_dmabuf *db,
+	enum dma_data_direction dir)
+{
+	db->buf = dma_alloc_coherent(chan->device->dev, PL011_DMA_BUFFER_SIZE,
+				     &db->dma, GFP_KERNEL);
+	if (!db->buf)
+		return -ENOMEM;
+	db->len = PL011_DMA_BUFFER_SIZE;
+
+	return 0;
+}
+
+static void pl011_dmabuf_free(struct dma_chan *chan, struct pl011_dmabuf *db,
+	enum dma_data_direction dir)
+{
+	if (db->buf) {
+		dma_free_coherent(chan->device->dev,
+				  PL011_DMA_BUFFER_SIZE, db->buf, db->dma);
+	}
+}
+
+static void pl011_dma_probe(struct uart_amba_port *uap)
+{
+	/* DMA is the sole user of the platform data right now */
+	struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev);
+	struct device *dev = uap->port.dev;
+	struct dma_slave_config tx_conf = {
+		.dst_addr = uap->port.mapbase +
+				 pl011_reg_to_offset(uap, REG_DR),
+		.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+		.direction = DMA_MEM_TO_DEV,
+		.dst_maxburst = uap->fifosize >> 1,
+		.device_fc = false,
+	};
+	struct dma_chan *chan;
+	dma_cap_mask_t mask;
+
+	uap->dma_probed = true;
+	chan = dma_request_chan(dev, "tx");
+	if (IS_ERR(chan)) {
+		if (PTR_ERR(chan) == -EPROBE_DEFER) {
+			uap->dma_probed = false;
+			return;
+		}
+
+		/* We need platform data */
+		if (!plat || !plat->dma_filter) {
+			dev_info(uap->port.dev, "no DMA platform data\n");
+			return;
+		}
+
+		/* Try to acquire a generic DMA engine slave TX channel */
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+
+		chan = dma_request_channel(mask, plat->dma_filter,
+						plat->dma_tx_param);
+		if (!chan) {
+			dev_err(uap->port.dev, "no TX DMA channel!\n");
+			return;
+		}
+	}
+
+	dmaengine_slave_config(chan, &tx_conf);
+	uap->dmatx.chan = chan;
+
+	dev_info(uap->port.dev, "DMA channel TX %s\n",
+		 dma_chan_name(uap->dmatx.chan));
+
+	/* Optionally make use of an RX channel as well */
+	chan = dma_request_slave_channel(dev, "rx");
+
+	if (!chan && plat && plat->dma_rx_param) {
+		chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
+
+		if (!chan) {
+			dev_err(uap->port.dev, "no RX DMA channel!\n");
+			return;
+		}
+	}
+
+	if (chan) {
+		struct dma_slave_config rx_conf = {
+			.src_addr = uap->port.mapbase +
+				pl011_reg_to_offset(uap, REG_DR),
+			.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+			.direction = DMA_DEV_TO_MEM,
+			.src_maxburst = uap->fifosize >> 2,
+			.device_fc = false,
+		};
+		struct dma_slave_caps caps;
+
+		/*
+		 * Some DMA controllers provide information on their capabilities.
+		 * If the controller does, check for suitable residue processing
+		 * otherwise assime all is well.
+		 */
+		if (0 == dma_get_slave_caps(chan, &caps)) {
+			if (caps.residue_granularity ==
+					DMA_RESIDUE_GRANULARITY_DESCRIPTOR) {
+				dma_release_channel(chan);
+				dev_info(uap->port.dev,
+					"RX DMA disabled - no residue processing\n");
+				return;
+			}
+		}
+		dmaengine_slave_config(chan, &rx_conf);
+		uap->dmarx.chan = chan;
+
+		uap->dmarx.auto_poll_rate = false;
+		if (plat && plat->dma_rx_poll_enable) {
+			/* Set poll rate if specified. */
+			if (plat->dma_rx_poll_rate) {
+				uap->dmarx.auto_poll_rate = false;
+				uap->dmarx.poll_rate = plat->dma_rx_poll_rate;
+			} else {
+				/*
+				 * 100 ms defaults to poll rate if not
+				 * specified. This will be adjusted with
+				 * the baud rate at set_termios.
+				 */
+				uap->dmarx.auto_poll_rate = true;
+				uap->dmarx.poll_rate =  100;
+			}
+			/* 3 secs defaults poll_timeout if not specified. */
+			if (plat->dma_rx_poll_timeout)
+				uap->dmarx.poll_timeout =
+					plat->dma_rx_poll_timeout;
+			else
+				uap->dmarx.poll_timeout = 3000;
+		} else if (!plat && dev->of_node) {
+			uap->dmarx.auto_poll_rate = of_property_read_bool(
+						dev->of_node, "auto-poll");
+			if (uap->dmarx.auto_poll_rate) {
+				u32 x;
+
+				if (0 == of_property_read_u32(dev->of_node,
+						"poll-rate-ms", &x))
+					uap->dmarx.poll_rate = x;
+				else
+					uap->dmarx.poll_rate = 100;
+				if (0 == of_property_read_u32(dev->of_node,
+						"poll-timeout-ms", &x))
+					uap->dmarx.poll_timeout = x;
+				else
+					uap->dmarx.poll_timeout = 3000;
+			}
+		}
+		dev_info(uap->port.dev, "DMA channel RX %s\n",
+			 dma_chan_name(uap->dmarx.chan));
+	}
+}
+
+static void pl011_dma_remove(struct uart_amba_port *uap)
+{
+	if (uap->dmatx.chan)
+		dma_release_channel(uap->dmatx.chan);
+	if (uap->dmarx.chan)
+		dma_release_channel(uap->dmarx.chan);
+}
+
+/* Forward declare these for the refill routine */
+static int pl011_dma_tx_refill(struct uart_amba_port *uap);
+static void pl011_start_tx_pio(struct uart_amba_port *uap);
+
+/*
+ * The current DMA TX buffer has been sent.
+ * Try to queue up another DMA buffer.
+ */
+static void pl011_dma_tx_callback(void *data)
+{
+	struct uart_amba_port *uap = data;
+	struct pl011_dmatx_data *dmatx = &uap->dmatx;
+	unsigned long flags;
+	u16 dmacr;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+	if (uap->dmatx.queued)
+		dma_unmap_single(dmatx->chan->device->dev, dmatx->dma,
+				dmatx->len, DMA_TO_DEVICE);
+
+	dmacr = uap->dmacr;
+	uap->dmacr = dmacr & ~UART011_TXDMAE;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+
+	/*
+	 * If TX DMA was disabled, it means that we've stopped the DMA for
+	 * some reason (eg, XOFF received, or we want to send an X-char.)
+	 *
+	 * Note: we need to be careful here of a potential race between DMA
+	 * and the rest of the driver - if the driver disables TX DMA while
+	 * a TX buffer completing, we must update the tx queued status to
+	 * get further refills (hence we check dmacr).
+	 */
+	if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
+	    uart_circ_empty(&uap->port.state->xmit)) {
+		uap->dmatx.queued = false;
+		spin_unlock_irqrestore(&uap->port.lock, flags);
+		return;
+	}
+
+	if (pl011_dma_tx_refill(uap) <= 0)
+		/*
+		 * We didn't queue a DMA buffer for some reason, but we
+		 * have data pending to be sent.  Re-enable the TX IRQ.
+		 */
+		pl011_start_tx_pio(uap);
+
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+/*
+ * Try to refill the TX DMA buffer.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ *   1 if we queued up a TX DMA buffer.
+ *   0 if we didn't want to handle this by DMA
+ *  <0 on error
+ */
+static int pl011_dma_tx_refill(struct uart_amba_port *uap)
+{
+	struct pl011_dmatx_data *dmatx = &uap->dmatx;
+	struct dma_chan *chan = dmatx->chan;
+	struct dma_device *dma_dev = chan->device;
+	struct dma_async_tx_descriptor *desc;
+	struct circ_buf *xmit = &uap->port.state->xmit;
+	unsigned int count;
+
+	/*
+	 * Try to avoid the overhead involved in using DMA if the
+	 * transaction fits in the first half of the FIFO, by using
+	 * the standard interrupt handling.  This ensures that we
+	 * issue a uart_write_wakeup() at the appropriate time.
+	 */
+	count = uart_circ_chars_pending(xmit);
+	if (count < (uap->fifosize >> 1)) {
+		uap->dmatx.queued = false;
+		return 0;
+	}
+
+	/*
+	 * Bodge: don't send the last character by DMA, as this
+	 * will prevent XON from notifying us to restart DMA.
+	 */
+	count -= 1;
+
+	/* Else proceed to copy the TX chars to the DMA buffer and fire DMA */
+	if (count > PL011_DMA_BUFFER_SIZE)
+		count = PL011_DMA_BUFFER_SIZE;
+
+	if (xmit->tail < xmit->head)
+		memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
+	else {
+		size_t first = UART_XMIT_SIZE - xmit->tail;
+		size_t second;
+
+		if (first > count)
+			first = count;
+		second = count - first;
+
+		memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
+		if (second)
+			memcpy(&dmatx->buf[first], &xmit->buf[0], second);
+	}
+
+	dmatx->len = count;
+	dmatx->dma = dma_map_single(dma_dev->dev, dmatx->buf, count,
+				    DMA_TO_DEVICE);
+	if (dmatx->dma == DMA_MAPPING_ERROR) {
+		uap->dmatx.queued = false;
+		dev_dbg(uap->port.dev, "unable to map TX DMA\n");
+		return -EBUSY;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, dmatx->dma, dmatx->len, DMA_MEM_TO_DEV,
+					     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dma_unmap_single(dma_dev->dev, dmatx->dma, dmatx->len, DMA_TO_DEVICE);
+		uap->dmatx.queued = false;
+		/*
+		 * If DMA cannot be used right now, we complete this
+		 * transaction via IRQ and let the TTY layer retry.
+		 */
+		dev_dbg(uap->port.dev, "TX DMA busy\n");
+		return -EBUSY;
+	}
+
+	/* Some data to go along to the callback */
+	desc->callback = pl011_dma_tx_callback;
+	desc->callback_param = uap;
+
+	/* All errors should happen at prepare time */
+	dmaengine_submit(desc);
+
+	/* Fire the DMA transaction */
+	dma_dev->device_issue_pending(chan);
+
+	uap->dmacr |= UART011_TXDMAE;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+	uap->dmatx.queued = true;
+
+	/*
+	 * Now we know that DMA will fire, so advance the ring buffer
+	 * with the stuff we just dispatched.
+	 */
+	uart_xmit_advance(&uap->port, count);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&uap->port);
+
+	return 1;
+}
+
+/*
+ * We received a transmit interrupt without a pending X-char but with
+ * pending characters.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ *   false if we want to use PIO to transmit
+ *   true if we queued a DMA buffer
+ */
+static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
+{
+	if (!uap->using_tx_dma)
+		return false;
+
+	/*
+	 * If we already have a TX buffer queued, but received a
+	 * TX interrupt, it will be because we've just sent an X-char.
+	 * Ensure the TX DMA is enabled and the TX IRQ is disabled.
+	 */
+	if (uap->dmatx.queued) {
+		uap->dmacr |= UART011_TXDMAE;
+		pl011_write(uap->dmacr, uap, REG_DMACR);
+		uap->im &= ~UART011_TXIM;
+		pl011_write(uap->im, uap, REG_IMSC);
+		return true;
+	}
+
+	/*
+	 * We don't have a TX buffer queued, so try to queue one.
+	 * If we successfully queued a buffer, mask the TX IRQ.
+	 */
+	if (pl011_dma_tx_refill(uap) > 0) {
+		uap->im &= ~UART011_TXIM;
+		pl011_write(uap->im, uap, REG_IMSC);
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Stop the DMA transmit (eg, due to received XOFF).
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
+{
+	if (uap->dmatx.queued) {
+		uap->dmacr &= ~UART011_TXDMAE;
+		pl011_write(uap->dmacr, uap, REG_DMACR);
+	}
+}
+
+/*
+ * Try to start a DMA transmit, or in the case of an XON/OFF
+ * character queued for send, try to get that character out ASAP.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ *   false if we want the TX IRQ to be enabled
+ *   true if we have a buffer queued
+ */
+static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
+{
+	u16 dmacr;
+
+	if (!uap->using_tx_dma)
+		return false;
+
+	if (!uap->port.x_char) {
+		/* no X-char, try to push chars out in DMA mode */
+		bool ret = true;
+
+		if (!uap->dmatx.queued) {
+			if (pl011_dma_tx_refill(uap) > 0) {
+				uap->im &= ~UART011_TXIM;
+				pl011_write(uap->im, uap, REG_IMSC);
+			} else
+				ret = false;
+		} else if (!(uap->dmacr & UART011_TXDMAE)) {
+			uap->dmacr |= UART011_TXDMAE;
+			pl011_write(uap->dmacr, uap, REG_DMACR);
+		}
+		return ret;
+	}
+
+	/*
+	 * We have an X-char to send.  Disable DMA to prevent it loading
+	 * the TX fifo, and then see if we can stuff it into the FIFO.
+	 */
+	dmacr = uap->dmacr;
+	uap->dmacr &= ~UART011_TXDMAE;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+
+	if (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) {
+		/*
+		 * No space in the FIFO, so enable the transmit interrupt
+		 * so we know when there is space.  Note that once we've
+		 * loaded the character, we should just re-enable DMA.
+		 */
+		return false;
+	}
+
+	pl011_write(uap->port.x_char, uap, REG_DR);
+	uap->port.icount.tx++;
+	uap->port.x_char = 0;
+
+	/* Success - restore the DMA state */
+	uap->dmacr = dmacr;
+	pl011_write(dmacr, uap, REG_DMACR);
+
+	return true;
+}
+
+/*
+ * Flush the transmit buffer.
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static void pl011_dma_flush_buffer(struct uart_port *port)
+__releases(&uap->port.lock)
+__acquires(&uap->port.lock)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	if (!uap->using_tx_dma)
+		return;
+
+	dmaengine_terminate_async(uap->dmatx.chan);
+
+	if (uap->dmatx.queued) {
+		dma_unmap_single(uap->dmatx.chan->device->dev, uap->dmatx.dma,
+				 uap->dmatx.len, DMA_TO_DEVICE);
+		uap->dmatx.queued = false;
+		uap->dmacr &= ~UART011_TXDMAE;
+		pl011_write(uap->dmacr, uap, REG_DMACR);
+	}
+}
+
+static void pl011_dma_rx_callback(void *data);
+
+static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
+{
+	struct dma_chan *rxchan = uap->dmarx.chan;
+	struct pl011_dmarx_data *dmarx = &uap->dmarx;
+	struct dma_async_tx_descriptor *desc;
+	struct pl011_dmabuf *dbuf;
+
+	if (!rxchan)
+		return -EIO;
+
+	/* Start the RX DMA job */
+	dbuf = uap->dmarx.use_buf_b ?
+		&uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
+	desc = dmaengine_prep_slave_single(rxchan, dbuf->dma, dbuf->len,
+					DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	/*
+	 * If the DMA engine is busy and cannot prepare a
+	 * channel, no big deal, the driver will fall back
+	 * to interrupt mode as a result of this error code.
+	 */
+	if (!desc) {
+		uap->dmarx.running = false;
+		dmaengine_terminate_all(rxchan);
+		return -EBUSY;
+	}
+
+	/* Some data to go along to the callback */
+	desc->callback = pl011_dma_rx_callback;
+	desc->callback_param = uap;
+	dmarx->cookie = dmaengine_submit(desc);
+	dma_async_issue_pending(rxchan);
+
+	uap->dmacr |= UART011_RXDMAE;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+	uap->dmarx.running = true;
+
+	uap->im &= ~UART011_RXIM;
+	pl011_write(uap->im, uap, REG_IMSC);
+
+	return 0;
+}
+
+/*
+ * This is called when either the DMA job is complete, or
+ * the FIFO timeout interrupt occurred. This must be called
+ * with the port spinlock uap->port.lock held.
+ */
+static void pl011_dma_rx_chars(struct uart_amba_port *uap,
+			       u32 pending, bool use_buf_b,
+			       bool readfifo)
+{
+	struct tty_port *port = &uap->port.state->port;
+	struct pl011_dmabuf *dbuf = use_buf_b ?
+		&uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
+	int dma_count = 0;
+	u32 fifotaken = 0; /* only used for vdbg() */
+
+	struct pl011_dmarx_data *dmarx = &uap->dmarx;
+	int dmataken = 0;
+
+	if (uap->dmarx.poll_rate) {
+		/* The data can be taken by polling */
+		dmataken = dbuf->len - dmarx->last_residue;
+		/* Recalculate the pending size */
+		if (pending >= dmataken)
+			pending -= dmataken;
+	}
+
+	/* Pick the remain data from the DMA */
+	if (pending) {
+
+		/*
+		 * First take all chars in the DMA pipe, then look in the FIFO.
+		 * Note that tty_insert_flip_buf() tries to take as many chars
+		 * as it can.
+		 */
+		dma_count = tty_insert_flip_string(port, dbuf->buf + dmataken,
+				pending);
+
+		uap->port.icount.rx += dma_count;
+		if (dma_count < pending)
+			dev_warn(uap->port.dev,
+				 "couldn't insert all characters (TTY is full?)\n");
+	}
+
+	/* Reset the last_residue for Rx DMA poll */
+	if (uap->dmarx.poll_rate)
+		dmarx->last_residue = dbuf->len;
+
+	/*
+	 * Only continue with trying to read the FIFO if all DMA chars have
+	 * been taken first.
+	 */
+	if (dma_count == pending && readfifo) {
+		/* Clear any error flags */
+		pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
+			    UART011_FEIS, uap, REG_ICR);
+
+		/*
+		 * If we read all the DMA'd characters, and we had an
+		 * incomplete buffer, that could be due to an rx error, or
+		 * maybe we just timed out. Read any pending chars and check
+		 * the error status.
+		 *
+		 * Error conditions will only occur in the FIFO, these will
+		 * trigger an immediate interrupt and stop the DMA job, so we
+		 * will always find the error in the FIFO, never in the DMA
+		 * buffer.
+		 */
+		fifotaken = pl011_fifo_to_tty(uap);
+	}
+
+	dev_vdbg(uap->port.dev,
+		 "Took %d chars from DMA buffer and %d chars from the FIFO\n",
+		 dma_count, fifotaken);
+	tty_flip_buffer_push(port);
+}
+
+static void pl011_dma_rx_irq(struct uart_amba_port *uap)
+{
+	struct pl011_dmarx_data *dmarx = &uap->dmarx;
+	struct dma_chan *rxchan = dmarx->chan;
+	struct pl011_dmabuf *dbuf = dmarx->use_buf_b ?
+		&dmarx->dbuf_b : &dmarx->dbuf_a;
+	size_t pending;
+	struct dma_tx_state state;
+	enum dma_status dmastat;
+
+	/*
+	 * Pause the transfer so we can trust the current counter,
+	 * do this before we pause the PL011 block, else we may
+	 * overflow the FIFO.
+	 */
+	if (dmaengine_pause(rxchan))
+		dev_err(uap->port.dev, "unable to pause DMA transfer\n");
+	dmastat = rxchan->device->device_tx_status(rxchan,
+						   dmarx->cookie, &state);
+	if (dmastat != DMA_PAUSED)
+		dev_err(uap->port.dev, "unable to pause DMA transfer\n");
+
+	/* Disable RX DMA - incoming data will wait in the FIFO */
+	uap->dmacr &= ~UART011_RXDMAE;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+	uap->dmarx.running = false;
+
+	pending = dbuf->len - state.residue;
+	BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
+	/* Then we terminate the transfer - we now know our residue */
+	dmaengine_terminate_all(rxchan);
+
+	/*
+	 * This will take the chars we have so far and insert
+	 * into the framework.
+	 */
+	pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true);
+
+	/* Switch buffer & re-trigger DMA job */
+	dmarx->use_buf_b = !dmarx->use_buf_b;
+	if (pl011_dma_rx_trigger_dma(uap)) {
+		dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
+			"fall back to interrupt mode\n");
+		uap->im |= UART011_RXIM;
+		pl011_write(uap->im, uap, REG_IMSC);
+	}
+}
+
+static void pl011_dma_rx_callback(void *data)
+{
+	struct uart_amba_port *uap = data;
+	struct pl011_dmarx_data *dmarx = &uap->dmarx;
+	struct dma_chan *rxchan = dmarx->chan;
+	bool lastbuf = dmarx->use_buf_b;
+	struct pl011_dmabuf *dbuf = dmarx->use_buf_b ?
+		&dmarx->dbuf_b : &dmarx->dbuf_a;
+	size_t pending;
+	struct dma_tx_state state;
+	int ret;
+
+	/*
+	 * This completion interrupt occurs typically when the
+	 * RX buffer is totally stuffed but no timeout has yet
+	 * occurred. When that happens, we just want the RX
+	 * routine to flush out the secondary DMA buffer while
+	 * we immediately trigger the next DMA job.
+	 */
+	spin_lock_irq(&uap->port.lock);
+	/*
+	 * Rx data can be taken by the UART interrupts during
+	 * the DMA irq handler. So we check the residue here.
+	 */
+	rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
+	pending = dbuf->len - state.residue;
+	BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
+	/* Then we terminate the transfer - we now know our residue */
+	dmaengine_terminate_all(rxchan);
+
+	uap->dmarx.running = false;
+	dmarx->use_buf_b = !lastbuf;
+	ret = pl011_dma_rx_trigger_dma(uap);
+
+	pl011_dma_rx_chars(uap, pending, lastbuf, false);
+	spin_unlock_irq(&uap->port.lock);
+	/*
+	 * Do this check after we picked the DMA chars so we don't
+	 * get some IRQ immediately from RX.
+	 */
+	if (ret) {
+		dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
+			"fall back to interrupt mode\n");
+		uap->im |= UART011_RXIM;
+		pl011_write(uap->im, uap, REG_IMSC);
+	}
+}
+
+/*
+ * Stop accepting received characters, when we're shutting down or
+ * suspending this port.
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
+{
+	if (!uap->using_rx_dma)
+		return;
+
+	/* FIXME.  Just disable the DMA enable */
+	uap->dmacr &= ~UART011_RXDMAE;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+}
+
+/*
+ * Timer handler for Rx DMA polling.
+ * Every polling, It checks the residue in the dma buffer and transfer
+ * data to the tty. Also, last_residue is updated for the next polling.
+ */
+static void pl011_dma_rx_poll(struct timer_list *t)
+{
+	struct uart_amba_port *uap = from_timer(uap, t, dmarx.timer);
+	struct tty_port *port = &uap->port.state->port;
+	struct pl011_dmarx_data *dmarx = &uap->dmarx;
+	struct dma_chan *rxchan = uap->dmarx.chan;
+	unsigned long flags;
+	unsigned int dmataken = 0;
+	unsigned int size = 0;
+	struct pl011_dmabuf *dbuf;
+	int dma_count;
+	struct dma_tx_state state;
+
+	dbuf = dmarx->use_buf_b ? &uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
+	rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
+	if (likely(state.residue < dmarx->last_residue)) {
+		dmataken = dbuf->len - dmarx->last_residue;
+		size = dmarx->last_residue - state.residue;
+		dma_count = tty_insert_flip_string(port, dbuf->buf + dmataken,
+				size);
+		if (dma_count == size)
+			dmarx->last_residue =  state.residue;
+		dmarx->last_jiffies = jiffies;
+	}
+	tty_flip_buffer_push(port);
+
+	/*
+	 * If no data is received in poll_timeout, the driver will fall back
+	 * to interrupt mode. We will retrigger DMA at the first interrupt.
+	 */
+	if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
+			> uap->dmarx.poll_timeout) {
+
+		spin_lock_irqsave(&uap->port.lock, flags);
+		pl011_dma_rx_stop(uap);
+		uap->im |= UART011_RXIM;
+		pl011_write(uap->im, uap, REG_IMSC);
+		spin_unlock_irqrestore(&uap->port.lock, flags);
+
+		uap->dmarx.running = false;
+		dmaengine_terminate_all(rxchan);
+		del_timer(&uap->dmarx.timer);
+	} else {
+		mod_timer(&uap->dmarx.timer,
+			jiffies + msecs_to_jiffies(uap->dmarx.poll_rate));
+	}
+}
+
+static void pl011_dma_startup(struct uart_amba_port *uap)
+{
+	int ret;
+
+	if (!uap->dma_probed)
+		pl011_dma_probe(uap);
+
+	if (!uap->dmatx.chan)
+		return;
+
+	uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA);
+	if (!uap->dmatx.buf) {
+		dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
+		uap->port.fifosize = uap->fifosize;
+		return;
+	}
+
+	uap->dmatx.len = PL011_DMA_BUFFER_SIZE;
+
+	/* The DMA buffer is now the FIFO the TTY subsystem can use */
+	uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
+	uap->using_tx_dma = true;
+
+	if (!uap->dmarx.chan)
+		goto skip_rx;
+
+	/* Allocate and map DMA RX buffers */
+	ret = pl011_dmabuf_init(uap->dmarx.chan, &uap->dmarx.dbuf_a,
+			       DMA_FROM_DEVICE);
+	if (ret) {
+		dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
+			"RX buffer A", ret);
+		goto skip_rx;
+	}
+
+	ret = pl011_dmabuf_init(uap->dmarx.chan, &uap->dmarx.dbuf_b,
+			       DMA_FROM_DEVICE);
+	if (ret) {
+		dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
+			"RX buffer B", ret);
+		pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_a,
+				 DMA_FROM_DEVICE);
+		goto skip_rx;
+	}
+
+	uap->using_rx_dma = true;
+
+skip_rx:
+	/* Turn on DMA error (RX/TX will be enabled on demand) */
+	uap->dmacr |= UART011_DMAONERR;
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+
+	/*
+	 * ST Micro variants has some specific dma burst threshold
+	 * compensation. Set this to 16 bytes, so burst will only
+	 * be issued above/below 16 bytes.
+	 */
+	if (uap->vendor->dma_threshold)
+		pl011_write(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
+			    uap, REG_ST_DMAWM);
+
+	if (uap->using_rx_dma) {
+		if (pl011_dma_rx_trigger_dma(uap))
+			dev_dbg(uap->port.dev, "could not trigger initial "
+				"RX DMA job, fall back to interrupt mode\n");
+		if (uap->dmarx.poll_rate) {
+			timer_setup(&uap->dmarx.timer, pl011_dma_rx_poll, 0);
+			mod_timer(&uap->dmarx.timer,
+				jiffies +
+				msecs_to_jiffies(uap->dmarx.poll_rate));
+			uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
+			uap->dmarx.last_jiffies = jiffies;
+		}
+	}
+}
+
+static void pl011_dma_shutdown(struct uart_amba_port *uap)
+{
+	if (!(uap->using_tx_dma || uap->using_rx_dma))
+		return;
+
+	/* Disable RX and TX DMA */
+	while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
+		cpu_relax();
+
+	spin_lock_irq(&uap->port.lock);
+	uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
+	pl011_write(uap->dmacr, uap, REG_DMACR);
+	spin_unlock_irq(&uap->port.lock);
+
+	if (uap->using_tx_dma) {
+		/* In theory, this should already be done by pl011_dma_flush_buffer */
+		dmaengine_terminate_all(uap->dmatx.chan);
+		if (uap->dmatx.queued) {
+			dma_unmap_single(uap->dmatx.chan->device->dev,
+					 uap->dmatx.dma, uap->dmatx.len,
+					 DMA_TO_DEVICE);
+			uap->dmatx.queued = false;
+		}
+
+		kfree(uap->dmatx.buf);
+		uap->using_tx_dma = false;
+	}
+
+	if (uap->using_rx_dma) {
+		dmaengine_terminate_all(uap->dmarx.chan);
+		/* Clean up the RX DMA */
+		pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_a, DMA_FROM_DEVICE);
+		pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_b, DMA_FROM_DEVICE);
+		if (uap->dmarx.poll_rate)
+			del_timer_sync(&uap->dmarx.timer);
+		uap->using_rx_dma = false;
+	}
+}
+
+static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
+{
+	return uap->using_rx_dma;
+}
+
+static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
+{
+	return uap->using_rx_dma && uap->dmarx.running;
+}
+
+#else
+/* Blank functions if the DMA engine is not available */
+static inline void pl011_dma_remove(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_startup(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_shutdown(struct uart_amba_port *uap)
+{
+}
+
+static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap)
+{
+	return false;
+}
+
+static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
+{
+}
+
+static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
+{
+	return false;
+}
+
+static inline void pl011_dma_rx_irq(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
+{
+}
+
+static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
+{
+	return -EIO;
+}
+
+static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
+{
+	return false;
+}
+
+static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
+{
+	return false;
+}
+
+#define pl011_dma_flush_buffer	NULL
+#endif
+
+static void pl011_rs485_tx_stop(struct uart_amba_port *uap)
+{
+	/*
+	 * To be on the safe side only time out after twice as many iterations
+	 * as fifo size.
+	 */
+	const int MAX_TX_DRAIN_ITERS = uap->port.fifosize * 2;
+	struct uart_port *port = &uap->port;
+	int i = 0;
+	u32 cr;
+
+	/* Wait until hardware tx queue is empty */
+	while (!pl011_tx_empty(port)) {
+		if (i > MAX_TX_DRAIN_ITERS) {
+			dev_warn(port->dev,
+				 "timeout while draining hardware tx queue\n");
+			break;
+		}
+
+		udelay(uap->rs485_tx_drain_interval);
+		i++;
+	}
+
+	if (port->rs485.delay_rts_after_send)
+		mdelay(port->rs485.delay_rts_after_send);
+
+	cr = pl011_read(uap, REG_CR);
+
+	if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+		cr &= ~UART011_CR_RTS;
+	else
+		cr |= UART011_CR_RTS;
+
+	/* Disable the transmitter and reenable the transceiver */
+	cr &= ~UART011_CR_TXE;
+	cr |= UART011_CR_RXE;
+	pl011_write(cr, uap, REG_CR);
+
+	uap->rs485_tx_started = false;
+}
+
+static void pl011_stop_tx(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	uap->im &= ~UART011_TXIM;
+	pl011_write(uap->im, uap, REG_IMSC);
+	pl011_dma_tx_stop(uap);
+
+	if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
+		pl011_rs485_tx_stop(uap);
+}
+
+static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
+
+/* Start TX with programmed I/O only (no DMA) */
+static void pl011_start_tx_pio(struct uart_amba_port *uap)
+{
+	if (pl011_tx_chars(uap, false)) {
+		uap->im |= UART011_TXIM;
+		pl011_write(uap->im, uap, REG_IMSC);
+	}
+}
+
+static void pl011_start_tx(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	if (!pl011_dma_tx_start(uap))
+		pl011_start_tx_pio(uap);
+}
+
+static void pl011_stop_rx(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
+		     UART011_PEIM|UART011_BEIM|UART011_OEIM);
+	pl011_write(uap->im, uap, REG_IMSC);
+
+	pl011_dma_rx_stop(uap);
+}
+
+static void pl011_throttle_rx(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	pl011_stop_rx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void pl011_enable_ms(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
+	pl011_write(uap->im, uap, REG_IMSC);
+}
+
+static void pl011_rx_chars(struct uart_amba_port *uap)
+__releases(&uap->port.lock)
+__acquires(&uap->port.lock)
+{
+	pl011_fifo_to_tty(uap);
+
+	spin_unlock(&uap->port.lock);
+	tty_flip_buffer_push(&uap->port.state->port);
+	/*
+	 * If we were temporarily out of DMA mode for a while,
+	 * attempt to switch back to DMA mode again.
+	 */
+	if (pl011_dma_rx_available(uap)) {
+		if (pl011_dma_rx_trigger_dma(uap)) {
+			dev_dbg(uap->port.dev, "could not trigger RX DMA job "
+				"fall back to interrupt mode again\n");
+			uap->im |= UART011_RXIM;
+			pl011_write(uap->im, uap, REG_IMSC);
+		} else {
+#ifdef CONFIG_DMA_ENGINE
+			/* Start Rx DMA poll */
+			if (uap->dmarx.poll_rate) {
+				uap->dmarx.last_jiffies = jiffies;
+				uap->dmarx.last_residue	= PL011_DMA_BUFFER_SIZE;
+				mod_timer(&uap->dmarx.timer,
+					jiffies +
+					msecs_to_jiffies(uap->dmarx.poll_rate));
+			}
+#endif
+		}
+	}
+	spin_lock(&uap->port.lock);
+}
+
+static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
+			  bool from_irq)
+{
+	if (unlikely(!from_irq) &&
+	    pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
+		return false; /* unable to transmit character */
+
+	pl011_write(c, uap, REG_DR);
+	uap->port.icount.tx++;
+
+	return true;
+}
+
+static void pl011_rs485_tx_start(struct uart_amba_port *uap)
+{
+	struct uart_port *port = &uap->port;
+	u32 cr;
+
+	/* Enable transmitter */
+	cr = pl011_read(uap, REG_CR);
+	cr |= UART011_CR_TXE;
+
+	/* Disable receiver if half-duplex */
+	if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+		cr &= ~UART011_CR_RXE;
+
+	if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
+		cr &= ~UART011_CR_RTS;
+	else
+		cr |= UART011_CR_RTS;
+
+	pl011_write(cr, uap, REG_CR);
+
+	if (port->rs485.delay_rts_before_send)
+		mdelay(port->rs485.delay_rts_before_send);
+
+	uap->rs485_tx_started = true;
+}
+
+/* Returns true if tx interrupts have to be (kept) enabled  */
+static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
+{
+	struct circ_buf *xmit = &uap->port.state->xmit;
+	int count = uap->fifosize >> 1;
+
+	if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
+	    !uap->rs485_tx_started)
+		pl011_rs485_tx_start(uap);
+
+	if (uap->port.x_char) {
+		if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
+			return true;
+		uap->port.x_char = 0;
+		--count;
+	}
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
+		pl011_stop_tx(&uap->port);
+		return false;
+	}
+
+	/* If we are using DMA mode, try to send some characters. */
+	if (pl011_dma_tx_irq(uap))
+		return true;
+
+	do {
+		if (likely(from_irq) && count-- == 0)
+			break;
+
+		if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq))
+			break;
+
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+	} while (!uart_circ_empty(xmit));
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&uap->port);
+
+	if (uart_circ_empty(xmit)) {
+		pl011_stop_tx(&uap->port);
+		return false;
+	}
+	return true;
+}
+
+static void pl011_modem_status(struct uart_amba_port *uap)
+{
+	unsigned int status, delta;
+
+	status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
+
+	delta = status ^ uap->old_status;
+	uap->old_status = status;
+
+	if (!delta)
+		return;
+
+	if (delta & UART01x_FR_DCD)
+		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
+
+	if (delta & uap->vendor->fr_dsr)
+		uap->port.icount.dsr++;
+
+	if (delta & uap->vendor->fr_cts)
+		uart_handle_cts_change(&uap->port,
+				       status & uap->vendor->fr_cts);
+
+	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
+}
+
+static void check_apply_cts_event_workaround(struct uart_amba_port *uap)
+{
+	if (!uap->vendor->cts_event_workaround)
+		return;
+
+	/* workaround to make sure that all bits are unlocked.. */
+	pl011_write(0x00, uap, REG_ICR);
+
+	/*
+	 * WA: introduce 26ns(1 uart clk) delay before W1C;
+	 * single apb access will incur 2 pclk(133.12Mhz) delay,
+	 * so add 2 dummy reads
+	 */
+	pl011_read(uap, REG_ICR);
+	pl011_read(uap, REG_ICR);
+}
+
+static irqreturn_t pl011_int(int irq, void *dev_id)
+{
+	struct uart_amba_port *uap = dev_id;
+	unsigned long flags;
+	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
+	int handled = 0;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+	status = pl011_read(uap, REG_RIS) & uap->im;
+	if (status) {
+		do {
+			check_apply_cts_event_workaround(uap);
+
+			pl011_write(status & ~(UART011_TXIS|UART011_RTIS|
+					       UART011_RXIS),
+				    uap, REG_ICR);
+
+			if (status & (UART011_RTIS|UART011_RXIS)) {
+				if (pl011_dma_rx_running(uap))
+					pl011_dma_rx_irq(uap);
+				else
+					pl011_rx_chars(uap);
+			}
+			if (status & (UART011_DSRMIS|UART011_DCDMIS|
+				      UART011_CTSMIS|UART011_RIMIS))
+				pl011_modem_status(uap);
+			if (status & UART011_TXIS)
+				pl011_tx_chars(uap, true);
+
+			if (pass_counter-- == 0)
+				break;
+
+			status = pl011_read(uap, REG_RIS) & uap->im;
+		} while (status != 0);
+		handled = 1;
+	}
+
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+
+	return IRQ_RETVAL(handled);
+}
+
+static unsigned int pl011_tx_empty(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	/* Allow feature register bits to be inverted to work around errata */
+	unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr;
+
+	return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ?
+							0 : TIOCSER_TEMT;
+}
+
+static unsigned int pl011_get_mctrl(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned int result = 0;
+	unsigned int status = pl011_read(uap, REG_FR);
+
+#define TIOCMBIT(uartbit, tiocmbit)	\
+	if (status & uartbit)		\
+		result |= tiocmbit
+
+	TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
+	TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
+	TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
+	TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
+#undef TIOCMBIT
+	return result;
+}
+
+static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned int cr;
+
+	cr = pl011_read(uap, REG_CR);
+
+#define	TIOCMBIT(tiocmbit, uartbit)		\
+	if (mctrl & tiocmbit)		\
+		cr |= uartbit;		\
+	else				\
+		cr &= ~uartbit
+
+	TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
+	TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
+	TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
+	TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
+	TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
+
+	if (port->status & UPSTAT_AUTORTS) {
+		/* We need to disable auto-RTS if we want to turn RTS off */
+		TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
+	}
+#undef TIOCMBIT
+
+	pl011_write(cr, uap, REG_CR);
+}
+
+static void pl011_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned long flags;
+	unsigned int lcr_h;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+	lcr_h = pl011_read(uap, REG_LCRH_TX);
+	if (break_state == -1)
+		lcr_h |= UART01x_LCRH_BRK;
+	else
+		lcr_h &= ~UART01x_LCRH_BRK;
+	pl011_write(lcr_h, uap, REG_LCRH_TX);
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static void pl011_quiesce_irqs(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	pl011_write(pl011_read(uap, REG_MIS), uap, REG_ICR);
+	/*
+	 * There is no way to clear TXIM as this is "ready to transmit IRQ", so
+	 * we simply mask it. start_tx() will unmask it.
+	 *
+	 * Note we can race with start_tx(), and if the race happens, the
+	 * polling user might get another interrupt just after we clear it.
+	 * But it should be OK and can happen even w/o the race, e.g.
+	 * controller immediately got some new data and raised the IRQ.
+	 *
+	 * And whoever uses polling routines assumes that it manages the device
+	 * (including tx queue), so we're also fine with start_tx()'s caller
+	 * side.
+	 */
+	pl011_write(pl011_read(uap, REG_IMSC) & ~UART011_TXIM, uap,
+		    REG_IMSC);
+}
+
+static int pl011_get_poll_char(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned int status;
+
+	/*
+	 * The caller might need IRQs lowered, e.g. if used with KDB NMI
+	 * debugger.
+	 */
+	pl011_quiesce_irqs(port);
+
+	status = pl011_read(uap, REG_FR);
+	if (status & UART01x_FR_RXFE)
+		return NO_POLL_CHAR;
+
+	return pl011_read(uap, REG_DR);
+}
+
+static void pl011_put_poll_char(struct uart_port *port,
+			 unsigned char ch)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
+		cpu_relax();
+
+	pl011_write(ch, uap, REG_DR);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static int pl011_hwinit(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	int retval;
+
+	/* Optionaly enable pins to be muxed in and configured */
+	pinctrl_pm_select_default_state(port->dev);
+
+	/*
+	 * Try to enable the clock producer.
+	 */
+	retval = clk_prepare_enable(uap->clk);
+	if (retval)
+		return retval;
+
+	uap->port.uartclk = clk_get_rate(uap->clk);
+
+	/* Clear pending error and receive interrupts */
+	pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
+		    UART011_FEIS | UART011_RTIS | UART011_RXIS,
+		    uap, REG_ICR);
+
+	/*
+	 * Save interrupts enable mask, and enable RX interrupts in case if
+	 * the interrupt is used for NMI entry.
+	 */
+	uap->im = pl011_read(uap, REG_IMSC);
+	pl011_write(UART011_RTIM | UART011_RXIM, uap, REG_IMSC);
+
+	if (dev_get_platdata(uap->port.dev)) {
+		struct amba_pl011_data *plat;
+
+		plat = dev_get_platdata(uap->port.dev);
+		if (plat->init)
+			plat->init();
+	}
+	return 0;
+}
+
+static bool pl011_split_lcrh(const struct uart_amba_port *uap)
+{
+	return pl011_reg_to_offset(uap, REG_LCRH_RX) !=
+	       pl011_reg_to_offset(uap, REG_LCRH_TX);
+}
+
+static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
+{
+	pl011_write(lcr_h, uap, REG_LCRH_RX);
+	if (pl011_split_lcrh(uap)) {
+		int i;
+		/*
+		 * Wait 10 PCLKs before writing LCRH_TX register,
+		 * to get this delay write read only register 10 times
+		 */
+		for (i = 0; i < 10; ++i)
+			pl011_write(0xff, uap, REG_MIS);
+		pl011_write(lcr_h, uap, REG_LCRH_TX);
+	}
+}
+
+static int pl011_allocate_irq(struct uart_amba_port *uap)
+{
+	pl011_write(uap->im, uap, REG_IMSC);
+
+	return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
+}
+
+/*
+ * Enable interrupts, only timeouts when using DMA
+ * if initial RX DMA job failed, start in interrupt mode
+ * as well.
+ */
+static void pl011_enable_interrupts(struct uart_amba_port *uap)
+{
+	unsigned long flags;
+	unsigned int i;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+
+	/* Clear out any spuriously appearing RX interrupts */
+	pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
+
+	/*
+	 * RXIS is asserted only when the RX FIFO transitions from below
+	 * to above the trigger threshold.  If the RX FIFO is already
+	 * full to the threshold this can't happen and RXIS will now be
+	 * stuck off.  Drain the RX FIFO explicitly to fix this:
+	 */
+	for (i = 0; i < uap->fifosize * 2; ++i) {
+		if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE)
+			break;
+
+		pl011_read(uap, REG_DR);
+	}
+
+	uap->im = UART011_RTIM;
+	if (!pl011_dma_rx_running(uap))
+		uap->im |= UART011_RXIM;
+	pl011_write(uap->im, uap, REG_IMSC);
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+static void pl011_unthrottle_rx(struct uart_port *port)
+{
+	struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+
+	uap->im = UART011_RTIM;
+	if (!pl011_dma_rx_running(uap))
+		uap->im |= UART011_RXIM;
+
+	pl011_write(uap->im, uap, REG_IMSC);
+
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+static int pl011_startup(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned int cr;
+	int retval;
+
+	retval = pl011_hwinit(port);
+	if (retval)
+		goto clk_dis;
+
+	retval = pl011_allocate_irq(uap);
+	if (retval)
+		goto clk_dis;
+
+	pl011_write(uap->vendor->ifls, uap, REG_IFLS);
+
+	spin_lock_irq(&uap->port.lock);
+
+	cr = pl011_read(uap, REG_CR);
+	cr &= UART011_CR_RTS | UART011_CR_DTR;
+	cr |= UART01x_CR_UARTEN | UART011_CR_RXE;
+
+	if (!(port->rs485.flags & SER_RS485_ENABLED))
+		cr |= UART011_CR_TXE;
+
+	pl011_write(cr, uap, REG_CR);
+
+	spin_unlock_irq(&uap->port.lock);
+
+	/*
+	 * initialise the old status of the modem signals
+	 */
+	uap->old_status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
+
+	/* Startup DMA */
+	pl011_dma_startup(uap);
+
+	pl011_enable_interrupts(uap);
+
+	return 0;
+
+ clk_dis:
+	clk_disable_unprepare(uap->clk);
+	return retval;
+}
+
+static int sbsa_uart_startup(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+	int retval;
+
+	retval = pl011_hwinit(port);
+	if (retval)
+		return retval;
+
+	retval = pl011_allocate_irq(uap);
+	if (retval)
+		return retval;
+
+	/* The SBSA UART does not support any modem status lines. */
+	uap->old_status = 0;
+
+	pl011_enable_interrupts(uap);
+
+	return 0;
+}
+
+static void pl011_shutdown_channel(struct uart_amba_port *uap,
+					unsigned int lcrh)
+{
+      unsigned long val;
+
+      val = pl011_read(uap, lcrh);
+      val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
+      pl011_write(val, uap, lcrh);
+}
+
+/*
+ * disable the port. It should not disable RTS and DTR.
+ * Also RTS and DTR state should be preserved to restore
+ * it during startup().
+ */
+static void pl011_disable_uart(struct uart_amba_port *uap)
+{
+	unsigned int cr;
+
+	uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
+	spin_lock_irq(&uap->port.lock);
+	cr = pl011_read(uap, REG_CR);
+	cr &= UART011_CR_RTS | UART011_CR_DTR;
+	cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
+	pl011_write(cr, uap, REG_CR);
+	spin_unlock_irq(&uap->port.lock);
+
+	/*
+	 * disable break condition and fifos
+	 */
+	pl011_shutdown_channel(uap, REG_LCRH_RX);
+	if (pl011_split_lcrh(uap))
+		pl011_shutdown_channel(uap, REG_LCRH_TX);
+}
+
+static void pl011_disable_interrupts(struct uart_amba_port *uap)
+{
+	spin_lock_irq(&uap->port.lock);
+
+	/* mask all interrupts and clear all pending ones */
+	uap->im = 0;
+	pl011_write(uap->im, uap, REG_IMSC);
+	pl011_write(0xffff, uap, REG_ICR);
+
+	spin_unlock_irq(&uap->port.lock);
+}
+
+static void pl011_shutdown(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+
+	pl011_disable_interrupts(uap);
+
+	pl011_dma_shutdown(uap);
+
+	if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
+		pl011_rs485_tx_stop(uap);
+
+	free_irq(uap->port.irq, uap);
+
+	pl011_disable_uart(uap);
+
+	/*
+	 * Shut down the clock producer
+	 */
+	clk_disable_unprepare(uap->clk);
+	/* Optionally let pins go into sleep states */
+	pinctrl_pm_select_sleep_state(port->dev);
+
+	if (dev_get_platdata(uap->port.dev)) {
+		struct amba_pl011_data *plat;
+
+		plat = dev_get_platdata(uap->port.dev);
+		if (plat->exit)
+			plat->exit();
+	}
+
+	if (uap->port.ops->flush_buffer)
+		uap->port.ops->flush_buffer(port);
+}
+
+static void sbsa_uart_shutdown(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+
+	pl011_disable_interrupts(uap);
+
+	free_irq(uap->port.irq, uap);
+
+	if (uap->port.ops->flush_buffer)
+		uap->port.ops->flush_buffer(port);
+}
+
+static void
+pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios)
+{
+	port->read_status_mask = UART011_DR_OE | 255;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART011_DR_FE | UART011_DR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= UART011_DR_BE;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= UART011_DR_BE;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= UART011_DR_OE;
+	}
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_DUMMY_DR_RX;
+}
+
+static void
+pl011_set_termios(struct uart_port *port, struct ktermios *termios,
+		  const struct ktermios *old)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned int lcr_h, old_cr;
+	unsigned long flags;
+	unsigned int baud, quot, clkdiv;
+	unsigned int bits;
+
+	if (uap->vendor->oversampling)
+		clkdiv = 8;
+	else
+		clkdiv = 16;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0,
+				  port->uartclk / clkdiv);
+#ifdef CONFIG_DMA_ENGINE
+	/*
+	 * Adjust RX DMA polling rate with baud rate if not specified.
+	 */
+	if (uap->dmarx.auto_poll_rate)
+		uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud);
+#endif
+
+	if (baud > port->uartclk/16)
+		quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
+	else
+		quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr_h = UART01x_LCRH_WLEN_5;
+		break;
+	case CS6:
+		lcr_h = UART01x_LCRH_WLEN_6;
+		break;
+	case CS7:
+		lcr_h = UART01x_LCRH_WLEN_7;
+		break;
+	default: // CS8
+		lcr_h = UART01x_LCRH_WLEN_8;
+		break;
+	}
+	if (termios->c_cflag & CSTOPB)
+		lcr_h |= UART01x_LCRH_STP2;
+	if (termios->c_cflag & PARENB) {
+		lcr_h |= UART01x_LCRH_PEN;
+		if (!(termios->c_cflag & PARODD))
+			lcr_h |= UART01x_LCRH_EPS;
+		if (termios->c_cflag & CMSPAR)
+			lcr_h |= UART011_LCRH_SPS;
+	}
+	if (uap->fifosize > 1)
+		lcr_h |= UART01x_LCRH_FEN;
+
+	bits = tty_get_frame_size(termios->c_cflag);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * Calculate the approximated time it takes to transmit one character
+	 * with the given baud rate. We use this as the poll interval when we
+	 * wait for the tx queue to empty.
+	 */
+	uap->rs485_tx_drain_interval = DIV_ROUND_UP(bits * 1000 * 1000, baud);
+
+	pl011_setup_status_masks(port, termios);
+
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		pl011_enable_ms(port);
+
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		termios->c_cflag &= ~CRTSCTS;
+
+	old_cr = pl011_read(uap, REG_CR);
+
+	if (termios->c_cflag & CRTSCTS) {
+		if (old_cr & UART011_CR_RTS)
+			old_cr |= UART011_CR_RTSEN;
+
+		old_cr |= UART011_CR_CTSEN;
+		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+	} else {
+		old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN);
+		port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
+	}
+
+	if (uap->vendor->oversampling) {
+		if (baud > port->uartclk / 16)
+			old_cr |= ST_UART011_CR_OVSFACT;
+		else
+			old_cr &= ~ST_UART011_CR_OVSFACT;
+	}
+
+	/*
+	 * Workaround for the ST Micro oversampling variants to
+	 * increase the bitrate slightly, by lowering the divisor,
+	 * to avoid delayed sampling of start bit at high speeds,
+	 * else we see data corruption.
+	 */
+	if (uap->vendor->oversampling) {
+		if ((baud >= 3000000) && (baud < 3250000) && (quot > 1))
+			quot -= 1;
+		else if ((baud > 3250000) && (quot > 2))
+			quot -= 2;
+	}
+	/* Set baud rate */
+	pl011_write(quot & 0x3f, uap, REG_FBRD);
+	pl011_write(quot >> 6, uap, REG_IBRD);
+
+	/*
+	 * ----------v----------v----------v----------v-----
+	 * NOTE: REG_LCRH_TX and REG_LCRH_RX MUST BE WRITTEN AFTER
+	 * REG_FBRD & REG_IBRD.
+	 * ----------^----------^----------^----------^-----
+	 */
+	pl011_write_lcr_h(uap, lcr_h);
+
+	/*
+	 * Receive was disabled by pl011_disable_uart during shutdown.
+	 * Need to reenable receive if you need to use a tty_driver
+	 * returns from tty_find_polling_driver() after a port shutdown.
+	 */
+	old_cr |= UART011_CR_RXE;
+	pl011_write(old_cr, uap, REG_CR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void
+sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios,
+		      const struct ktermios *old)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	unsigned long flags;
+
+	tty_termios_encode_baud_rate(termios, uap->fixed_baud, uap->fixed_baud);
+
+	/* The SBSA UART only supports 8n1 without hardware flow control. */
+	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
+	termios->c_cflag &= ~(CMSPAR | CRTSCTS);
+	termios->c_cflag |= CS8 | CLOCAL;
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_update_timeout(port, CS8, uap->fixed_baud);
+	pl011_setup_status_masks(port, termios);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *pl011_type(struct uart_port *port)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+	return uap->port.type == PORT_AMBA ? uap->type : NULL;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void pl011_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_AMBA;
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
+		ret = -EINVAL;
+	if (ser->irq < 0 || ser->irq >= nr_irqs)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	if (port->mapbase != (unsigned long) ser->iomem_base)
+		ret = -EINVAL;
+	return ret;
+}
+
+static int pl011_rs485_config(struct uart_port *port, struct ktermios *termios,
+			      struct serial_rs485 *rs485)
+{
+	struct uart_amba_port *uap =
+		container_of(port, struct uart_amba_port, port);
+
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		pl011_rs485_tx_stop(uap);
+
+	/* Make sure auto RTS is disabled */
+	if (rs485->flags & SER_RS485_ENABLED) {
+		u32 cr = pl011_read(uap, REG_CR);
+
+		cr &= ~UART011_CR_RTSEN;
+		pl011_write(cr, uap, REG_CR);
+		port->status &= ~UPSTAT_AUTORTS;
+	}
+
+	return 0;
+}
+
+static const struct uart_ops amba_pl011_pops = {
+	.tx_empty	= pl011_tx_empty,
+	.set_mctrl	= pl011_set_mctrl,
+	.get_mctrl	= pl011_get_mctrl,
+	.stop_tx	= pl011_stop_tx,
+	.start_tx	= pl011_start_tx,
+	.stop_rx	= pl011_stop_rx,
+	.throttle	= pl011_throttle_rx,
+	.unthrottle	= pl011_unthrottle_rx,
+	.enable_ms	= pl011_enable_ms,
+	.break_ctl	= pl011_break_ctl,
+	.startup	= pl011_startup,
+	.shutdown	= pl011_shutdown,
+	.flush_buffer	= pl011_dma_flush_buffer,
+	.set_termios	= pl011_set_termios,
+	.type		= pl011_type,
+	.config_port	= pl011_config_port,
+	.verify_port	= pl011_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init     = pl011_hwinit,
+	.poll_get_char = pl011_get_poll_char,
+	.poll_put_char = pl011_put_poll_char,
+#endif
+};
+
+static void sbsa_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int sbsa_uart_get_mctrl(struct uart_port *port)
+{
+	return 0;
+}
+
+static const struct uart_ops sbsa_uart_pops = {
+	.tx_empty	= pl011_tx_empty,
+	.set_mctrl	= sbsa_uart_set_mctrl,
+	.get_mctrl	= sbsa_uart_get_mctrl,
+	.stop_tx	= pl011_stop_tx,
+	.start_tx	= pl011_start_tx,
+	.stop_rx	= pl011_stop_rx,
+	.startup	= sbsa_uart_startup,
+	.shutdown	= sbsa_uart_shutdown,
+	.set_termios	= sbsa_uart_set_termios,
+	.type		= pl011_type,
+	.config_port	= pl011_config_port,
+	.verify_port	= pl011_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init     = pl011_hwinit,
+	.poll_get_char = pl011_get_poll_char,
+	.poll_put_char = pl011_put_poll_char,
+#endif
+};
+
+static struct uart_amba_port *amba_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
+
+static void pl011_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_amba_port *uap =
+	    container_of(port, struct uart_amba_port, port);
+
+	while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
+		cpu_relax();
+	pl011_write(ch, uap, REG_DR);
+}
+
+static void
+pl011_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_amba_port *uap = amba_ports[co->index];
+	unsigned int old_cr = 0, new_cr;
+	unsigned long flags;
+	int locked = 1;
+
+	clk_enable(uap->clk);
+
+	local_irq_save(flags);
+	if (uap->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&uap->port.lock);
+	else
+		spin_lock(&uap->port.lock);
+
+	/*
+	 *	First save the CR then disable the interrupts
+	 */
+	if (!uap->vendor->always_enabled) {
+		old_cr = pl011_read(uap, REG_CR);
+		new_cr = old_cr & ~UART011_CR_CTSEN;
+		new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
+		pl011_write(new_cr, uap, REG_CR);
+	}
+
+	uart_console_write(&uap->port, s, count, pl011_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty and restore the
+	 *	TCR. Allow feature register bits to be inverted to work around
+	 *	errata.
+	 */
+	while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr)
+						& uap->vendor->fr_busy)
+		cpu_relax();
+	if (!uap->vendor->always_enabled)
+		pl011_write(old_cr, uap, REG_CR);
+
+	if (locked)
+		spin_unlock(&uap->port.lock);
+	local_irq_restore(flags);
+
+	clk_disable(uap->clk);
+}
+
+static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
+				      int *parity, int *bits)
+{
+	if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) {
+		unsigned int lcr_h, ibrd, fbrd;
+
+		lcr_h = pl011_read(uap, REG_LCRH_TX);
+
+		*parity = 'n';
+		if (lcr_h & UART01x_LCRH_PEN) {
+			if (lcr_h & UART01x_LCRH_EPS)
+				*parity = 'e';
+			else
+				*parity = 'o';
+		}
+
+		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
+			*bits = 7;
+		else
+			*bits = 8;
+
+		ibrd = pl011_read(uap, REG_IBRD);
+		fbrd = pl011_read(uap, REG_FBRD);
+
+		*baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
+
+		if (uap->vendor->oversampling) {
+			if (pl011_read(uap, REG_CR)
+				  & ST_UART011_CR_OVSFACT)
+				*baud *= 2;
+		}
+	}
+}
+
+static int pl011_console_setup(struct console *co, char *options)
+{
+	struct uart_amba_port *uap;
+	int baud = 38400;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= UART_NR)
+		co->index = 0;
+	uap = amba_ports[co->index];
+	if (!uap)
+		return -ENODEV;
+
+	/* Allow pins to be muxed in and configured */
+	pinctrl_pm_select_default_state(uap->port.dev);
+
+	ret = clk_prepare(uap->clk);
+	if (ret)
+		return ret;
+
+	if (dev_get_platdata(uap->port.dev)) {
+		struct amba_pl011_data *plat;
+
+		plat = dev_get_platdata(uap->port.dev);
+		if (plat->init)
+			plat->init();
+	}
+
+	uap->port.uartclk = clk_get_rate(uap->clk);
+
+	if (uap->vendor->fixed_options) {
+		baud = uap->fixed_baud;
+	} else {
+		if (options)
+			uart_parse_options(options,
+					   &baud, &parity, &bits, &flow);
+		else
+			pl011_console_get_options(uap, &baud, &parity, &bits);
+	}
+
+	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
+}
+
+/**
+ *	pl011_console_match - non-standard console matching
+ *	@co:	  registering console
+ *	@name:	  name from console command line
+ *	@idx:	  index from console command line
+ *	@options: ptr to option string from console command line
+ *
+ *	Only attempts to match console command lines of the form:
+ *	    console=pl011,mmio|mmio32,<addr>[,<options>]
+ *	    console=pl011,0x<addr>[,<options>]
+ *	This form is used to register an initial earlycon boot console and
+ *	replace it with the amba_console at pl011 driver init.
+ *
+ *	Performs console setup for a match (as required by interface)
+ *	If no <options> are specified, then assume the h/w is already setup.
+ *
+ *	Returns 0 if console matches; otherwise non-zero to use default matching
+ */
+static int pl011_console_match(struct console *co, char *name, int idx,
+			       char *options)
+{
+	unsigned char iotype;
+	resource_size_t addr;
+	int i;
+
+	/*
+	 * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum
+	 * have a distinct console name, so make sure we check for that.
+	 * The actual implementation of the erratum occurs in the probe
+	 * function.
+	 */
+	if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0))
+		return -ENODEV;
+
+	if (uart_parse_earlycon(options, &iotype, &addr, &options))
+		return -ENODEV;
+
+	if (iotype != UPIO_MEM && iotype != UPIO_MEM32)
+		return -ENODEV;
+
+	/* try to match the port specified on the command line */
+	for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
+		struct uart_port *port;
+
+		if (!amba_ports[i])
+			continue;
+
+		port = &amba_ports[i]->port;
+
+		if (port->mapbase != addr)
+			continue;
+
+		co->index = i;
+		port->cons = co;
+		return pl011_console_setup(co, options);
+	}
+
+	return -ENODEV;
+}
+
+static struct uart_driver amba_reg;
+static struct console amba_console = {
+	.name		= "ttyAMA",
+	.write		= pl011_console_write,
+	.device		= uart_console_device,
+	.setup		= pl011_console_setup,
+	.match		= pl011_console_match,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+	.index		= -1,
+	.data		= &amba_reg,
+};
+
+#define AMBA_CONSOLE	(&amba_console)
+
+static void qdf2400_e44_putc(struct uart_port *port, unsigned char c)
+{
+	while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
+		cpu_relax();
+	writel(c, port->membase + UART01x_DR);
+	while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE))
+		cpu_relax();
+}
+
+static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, qdf2400_e44_putc);
+}
+
+static void pl011_putc(struct uart_port *port, unsigned char c)
+{
+	while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
+		cpu_relax();
+	if (port->iotype == UPIO_MEM32)
+		writel(c, port->membase + UART01x_DR);
+	else
+		writeb(c, port->membase + UART01x_DR);
+	while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
+		cpu_relax();
+}
+
+static void pl011_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, pl011_putc);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int pl011_getc(struct uart_port *port)
+{
+	if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE)
+		return NO_POLL_CHAR;
+
+	if (port->iotype == UPIO_MEM32)
+		return readl(port->membase + UART01x_DR);
+	else
+		return readb(port->membase + UART01x_DR);
+}
+
+static int pl011_early_read(struct console *con, char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+	int ch, num_read = 0;
+
+	while (num_read < n) {
+		ch = pl011_getc(&dev->port);
+		if (ch == NO_POLL_CHAR)
+			break;
+
+		s[num_read++] = ch;
+	}
+
+	return num_read;
+}
+#else
+#define pl011_early_read NULL
+#endif
+
+/*
+ * On non-ACPI systems, earlycon is enabled by specifying
+ * "earlycon=pl011,<address>" on the kernel command line.
+ *
+ * On ACPI ARM64 systems, an "early" console is enabled via the SPCR table,
+ * by specifying only "earlycon" on the command line.  Because it requires
+ * SPCR, the console starts after ACPI is parsed, which is later than a
+ * traditional early console.
+ *
+ * To get the traditional early console that starts before ACPI is parsed,
+ * specify the full "earlycon=pl011,<address>" option.
+ */
+static int __init pl011_early_console_setup(struct earlycon_device *device,
+					    const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = pl011_early_write;
+	device->con->read = pl011_early_read;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);
+OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup);
+
+/*
+ * On Qualcomm Datacenter Technologies QDF2400 SOCs affected by
+ * Erratum 44, traditional earlycon can be enabled by specifying
+ * "earlycon=qdf2400_e44,<address>".  Any options are ignored.
+ *
+ * Alternatively, you can just specify "earlycon", and the early console
+ * will be enabled with the information from the SPCR table.  In this
+ * case, the SPCR code will detect the need for the E44 work-around,
+ * and set the console name to "qdf2400_e44".
+ */
+static int __init
+qdf2400_e44_early_console_setup(struct earlycon_device *device,
+				const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = qdf2400_e44_early_write;
+	return 0;
+}
+EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup);
+
+#else
+#define AMBA_CONSOLE	NULL
+#endif
+
+static struct uart_driver amba_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "ttyAMA",
+	.dev_name		= "ttyAMA",
+	.major			= SERIAL_AMBA_MAJOR,
+	.minor			= SERIAL_AMBA_MINOR,
+	.nr			= UART_NR,
+	.cons			= AMBA_CONSOLE,
+};
+
+static int pl011_probe_dt_alias(int index, struct device *dev)
+{
+	struct device_node *np;
+	static bool seen_dev_with_alias = false;
+	static bool seen_dev_without_alias = false;
+	int ret = index;
+
+	if (!IS_ENABLED(CONFIG_OF))
+		return ret;
+
+	np = dev->of_node;
+	if (!np)
+		return ret;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		seen_dev_without_alias = true;
+		ret = index;
+	} else {
+		seen_dev_with_alias = true;
+		if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) {
+			dev_warn(dev, "requested serial port %d  not available.\n", ret);
+			ret = index;
+		}
+	}
+
+	if (seen_dev_with_alias && seen_dev_without_alias)
+		dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n");
+
+	return ret;
+}
+
+/* unregisters the driver also if no more ports are left */
+static void pl011_unregister_port(struct uart_amba_port *uap)
+{
+	int i;
+	bool busy = false;
+
+	for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
+		if (amba_ports[i] == uap)
+			amba_ports[i] = NULL;
+		else if (amba_ports[i])
+			busy = true;
+	}
+	pl011_dma_remove(uap);
+	if (!busy)
+		uart_unregister_driver(&amba_reg);
+}
+
+static int pl011_find_free_port(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+		if (amba_ports[i] == NULL)
+			return i;
+
+	return -EBUSY;
+}
+
+static int pl011_get_rs485_mode(struct uart_amba_port *uap)
+{
+	struct uart_port *port = &uap->port;
+	int ret;
+
+	ret = uart_get_rs485_mode(port);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
+			    struct resource *mmiobase, int index)
+{
+	void __iomem *base;
+	int ret;
+
+	base = devm_ioremap_resource(dev, mmiobase);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	index = pl011_probe_dt_alias(index, dev);
+
+	uap->port.dev = dev;
+	uap->port.mapbase = mmiobase->start;
+	uap->port.membase = base;
+	uap->port.fifosize = uap->fifosize;
+	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
+	uap->port.flags = UPF_BOOT_AUTOCONF;
+	uap->port.line = index;
+
+	ret = pl011_get_rs485_mode(uap);
+	if (ret)
+		return ret;
+
+	amba_ports[index] = uap;
+
+	return 0;
+}
+
+static int pl011_register_port(struct uart_amba_port *uap)
+{
+	int ret, i;
+
+	/* Ensure interrupts from this UART are masked and cleared */
+	pl011_write(0, uap, REG_IMSC);
+	pl011_write(0xffff, uap, REG_ICR);
+
+	if (!amba_reg.state) {
+		ret = uart_register_driver(&amba_reg);
+		if (ret < 0) {
+			dev_err(uap->port.dev,
+				"Failed to register AMBA-PL011 driver\n");
+			for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+				if (amba_ports[i] == uap)
+					amba_ports[i] = NULL;
+			return ret;
+		}
+	}
+
+	ret = uart_add_one_port(&amba_reg, &uap->port);
+	if (ret)
+		pl011_unregister_port(uap);
+
+	return ret;
+}
+
+static const struct serial_rs485 pl011_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+		 SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
+{
+	struct uart_amba_port *uap;
+	struct vendor_data *vendor = id->data;
+	int portnr, ret;
+	u32 val;
+
+	portnr = pl011_find_free_port();
+	if (portnr < 0)
+		return portnr;
+
+	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
+			   GFP_KERNEL);
+	if (!uap)
+		return -ENOMEM;
+
+	uap->clk = devm_clk_get(&dev->dev, NULL);
+	if (IS_ERR(uap->clk))
+		return PTR_ERR(uap->clk);
+
+	uap->reg_offset = vendor->reg_offset;
+	uap->vendor = vendor;
+	uap->fifosize = vendor->get_fifosize(dev);
+	uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
+	uap->port.irq = dev->irq[0];
+	uap->port.ops = &amba_pl011_pops;
+	uap->port.rs485_config = pl011_rs485_config;
+	uap->port.rs485_supported = pl011_rs485_supported;
+	snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
+
+	if (device_property_read_u32(&dev->dev, "reg-io-width", &val) == 0) {
+		switch (val) {
+		case 1:
+			uap->port.iotype = UPIO_MEM;
+			break;
+		case 4:
+			uap->port.iotype = UPIO_MEM32;
+			break;
+		default:
+			dev_warn(&dev->dev, "unsupported reg-io-width (%d)\n",
+				 val);
+			return -EINVAL;
+		}
+	}
+
+	ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
+	if (ret)
+		return ret;
+
+	amba_set_drvdata(dev, uap);
+
+	return pl011_register_port(uap);
+}
+
+static void pl011_remove(struct amba_device *dev)
+{
+	struct uart_amba_port *uap = amba_get_drvdata(dev);
+
+	uart_remove_one_port(&amba_reg, &uap->port);
+	pl011_unregister_port(uap);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pl011_suspend(struct device *dev)
+{
+	struct uart_amba_port *uap = dev_get_drvdata(dev);
+
+	if (!uap)
+		return -EINVAL;
+
+	return uart_suspend_port(&amba_reg, &uap->port);
+}
+
+static int pl011_resume(struct device *dev)
+{
+	struct uart_amba_port *uap = dev_get_drvdata(dev);
+
+	if (!uap)
+		return -EINVAL;
+
+	return uart_resume_port(&amba_reg, &uap->port);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume);
+
+static int sbsa_uart_probe(struct platform_device *pdev)
+{
+	struct uart_amba_port *uap;
+	struct resource *r;
+	int portnr, ret;
+	int baudrate;
+
+	/*
+	 * Check the mandatory baud rate parameter in the DT node early
+	 * so that we can easily exit with the error.
+	 */
+	if (pdev->dev.of_node) {
+		struct device_node *np = pdev->dev.of_node;
+
+		ret = of_property_read_u32(np, "current-speed", &baudrate);
+		if (ret)
+			return ret;
+	} else {
+		baudrate = 115200;
+	}
+
+	portnr = pl011_find_free_port();
+	if (portnr < 0)
+		return portnr;
+
+	uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port),
+			   GFP_KERNEL);
+	if (!uap)
+		return -ENOMEM;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	uap->port.irq	= ret;
+
+#ifdef CONFIG_ACPI_SPCR_TABLE
+	if (qdf2400_e44_present) {
+		dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n");
+		uap->vendor = &vendor_qdt_qdf2400_e44;
+	} else
+#endif
+		uap->vendor = &vendor_sbsa;
+
+	uap->reg_offset	= uap->vendor->reg_offset;
+	uap->fifosize	= 32;
+	uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
+	uap->port.ops	= &sbsa_uart_pops;
+	uap->fixed_baud = baudrate;
+
+	snprintf(uap->type, sizeof(uap->type), "SBSA");
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	ret = pl011_setup_port(&pdev->dev, uap, r, portnr);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, uap);
+
+	return pl011_register_port(uap);
+}
+
+static int sbsa_uart_remove(struct platform_device *pdev)
+{
+	struct uart_amba_port *uap = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&amba_reg, &uap->port);
+	pl011_unregister_port(uap);
+	return 0;
+}
+
+static const struct of_device_id sbsa_uart_of_match[] = {
+	{ .compatible = "arm,sbsa-uart", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sbsa_uart_of_match);
+
+static const struct acpi_device_id __maybe_unused sbsa_uart_acpi_match[] = {
+	{ "ARMH0011", 0 },
+	{ "ARMHB000", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match);
+
+static struct platform_driver arm_sbsa_uart_platform_driver = {
+	.probe		= sbsa_uart_probe,
+	.remove		= sbsa_uart_remove,
+	.driver	= {
+		.name	= "sbsa-uart",
+		.pm	= &pl011_dev_pm_ops,
+		.of_match_table = of_match_ptr(sbsa_uart_of_match),
+		.acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match),
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
+	},
+};
+
+static const struct amba_id pl011_ids[] = {
+	{
+		.id	= 0x00041011,
+		.mask	= 0x000fffff,
+		.data	= &vendor_arm,
+	},
+	{
+		.id	= 0x00380802,
+		.mask	= 0x00ffffff,
+		.data	= &vendor_st,
+	},
+	{ 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl011_ids);
+
+static struct amba_driver pl011_driver = {
+	.drv = {
+		.name	= "uart-pl011",
+		.pm	= &pl011_dev_pm_ops,
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
+	},
+	.id_table	= pl011_ids,
+	.probe		= pl011_probe,
+	.remove		= pl011_remove,
+};
+
+static int __init pl011_init(void)
+{
+	printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
+
+	if (platform_driver_register(&arm_sbsa_uart_platform_driver))
+		pr_warn("could not register SBSA UART platform driver\n");
+	return amba_driver_register(&pl011_driver);
+}
+
+static void __exit pl011_exit(void)
+{
+	platform_driver_unregister(&arm_sbsa_uart_platform_driver);
+	amba_driver_unregister(&pl011_driver);
+}
+
+/*
+ * While this can be a module, if builtin it's most likely the console
+ * So let's leave module_exit but move module_init to an earlier place
+ */
+arch_initcall(pl011_init);
+module_exit(pl011_exit);
+
+MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
+MODULE_DESCRIPTION("ARM AMBA serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c
new file mode 100644
index 000000000..d3cb341f2
--- /dev/null
+++ b/drivers/tty/serial/apbuart.c
@@ -0,0 +1,662 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Driver for GRLIB serial ports (APBUART)
+ *
+ *  Based on linux/drivers/serial/amba.c
+ *
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ *  Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
+ *  Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
+ *  Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
+ *  Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
+ */
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/kthread.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <asm/irq.h>
+
+#include "apbuart.h"
+
+#define SERIAL_APBUART_MAJOR	TTY_MAJOR
+#define SERIAL_APBUART_MINOR	64
+#define UART_DUMMY_RSR_RX	0x8000	/* for ignore all read */
+
+static void apbuart_tx_chars(struct uart_port *port);
+
+static void apbuart_stop_tx(struct uart_port *port)
+{
+	unsigned int cr;
+
+	cr = UART_GET_CTRL(port);
+	cr &= ~UART_CTRL_TI;
+	UART_PUT_CTRL(port, cr);
+}
+
+static void apbuart_start_tx(struct uart_port *port)
+{
+	unsigned int cr;
+
+	cr = UART_GET_CTRL(port);
+	cr |= UART_CTRL_TI;
+	UART_PUT_CTRL(port, cr);
+
+	if (UART_GET_STATUS(port) & UART_STATUS_THE)
+		apbuart_tx_chars(port);
+}
+
+static void apbuart_stop_rx(struct uart_port *port)
+{
+	unsigned int cr;
+
+	cr = UART_GET_CTRL(port);
+	cr &= ~(UART_CTRL_RI);
+	UART_PUT_CTRL(port, cr);
+}
+
+static void apbuart_rx_chars(struct uart_port *port)
+{
+	unsigned int status, rsr;
+	unsigned int max_chars = port->fifosize;
+	u8 ch, flag;
+
+	status = UART_GET_STATUS(port);
+
+	while (UART_RX_DATA(status) && (max_chars--)) {
+
+		ch = UART_GET_CHAR(port);
+		flag = TTY_NORMAL;
+
+		port->icount.rx++;
+
+		rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
+		UART_PUT_STATUS(port, 0);
+		if (rsr & UART_STATUS_ERR) {
+
+			if (rsr & UART_STATUS_BR) {
+				rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					goto ignore_char;
+			} else if (rsr & UART_STATUS_PE) {
+				port->icount.parity++;
+			} else if (rsr & UART_STATUS_FE) {
+				port->icount.frame++;
+			}
+			if (rsr & UART_STATUS_OE)
+				port->icount.overrun++;
+
+			rsr &= port->read_status_mask;
+
+			if (rsr & UART_STATUS_PE)
+				flag = TTY_PARITY;
+			else if (rsr & UART_STATUS_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			goto ignore_char;
+
+		uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
+
+
+	      ignore_char:
+		status = UART_GET_STATUS(port);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void apbuart_tx_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx_limited(port, ch, port->fifosize,
+		true,
+		UART_PUT_CHAR(port, ch),
+		({}));
+}
+
+static irqreturn_t apbuart_int(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned int status;
+
+	spin_lock(&port->lock);
+
+	status = UART_GET_STATUS(port);
+	if (status & UART_STATUS_DR)
+		apbuart_rx_chars(port);
+	if (status & UART_STATUS_THE)
+		apbuart_tx_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int apbuart_tx_empty(struct uart_port *port)
+{
+	unsigned int status = UART_GET_STATUS(port);
+	return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int apbuart_get_mctrl(struct uart_port *port)
+{
+	/* The GRLIB APBUART handles flow control in hardware */
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* The GRLIB APBUART handles flow control in hardware */
+}
+
+static void apbuart_break_ctl(struct uart_port *port, int break_state)
+{
+	/* We don't support sending break */
+}
+
+static int apbuart_startup(struct uart_port *port)
+{
+	int retval;
+	unsigned int cr;
+
+	/* Allocate the IRQ */
+	retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
+	if (retval)
+		return retval;
+
+	/* Finally, enable interrupts */
+	cr = UART_GET_CTRL(port);
+	UART_PUT_CTRL(port,
+		      cr | UART_CTRL_RE | UART_CTRL_TE |
+		      UART_CTRL_RI | UART_CTRL_TI);
+
+	return 0;
+}
+
+static void apbuart_shutdown(struct uart_port *port)
+{
+	unsigned int cr;
+
+	/* disable all interrupts, disable the port */
+	cr = UART_GET_CTRL(port);
+	UART_PUT_CTRL(port,
+		      cr & ~(UART_CTRL_RE | UART_CTRL_TE |
+			     UART_CTRL_RI | UART_CTRL_TI));
+
+	/* Free the interrupt */
+	free_irq(port->irq, port);
+}
+
+static void apbuart_set_termios(struct uart_port *port,
+				struct ktermios *termios, const struct ktermios *old)
+{
+	unsigned int cr;
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	/* Ask the core to calculate the divisor for us. */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+	if (baud == 0)
+		panic("invalid baudrate %i\n", port->uartclk / 16);
+
+	/* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
+	quot = (uart_get_divisor(port, baud)) * 2;
+	cr = UART_GET_CTRL(port);
+	cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
+
+	if (termios->c_cflag & PARENB) {
+		cr |= UART_CTRL_PE;
+		if ((termios->c_cflag & PARODD))
+			cr |= UART_CTRL_PS;
+	}
+
+	/* Enable flow control. */
+	if (termios->c_cflag & CRTSCTS)
+		cr |= UART_CTRL_FL;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Update the per-port timeout. */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = UART_STATUS_OE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
+
+	/* Characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
+
+	/* Ignore all characters if CREAD is not set. */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_DUMMY_RSR_RX;
+
+	/* Set baud rate */
+	quot -= 1;
+	UART_PUT_SCAL(port, quot);
+	UART_PUT_CTRL(port, cr);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *apbuart_type(struct uart_port *port)
+{
+	return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
+}
+
+static void apbuart_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, 0x100);
+}
+
+static int apbuart_request_port(struct uart_port *port)
+{
+	return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
+	    != NULL ? 0 : -EBUSY;
+	return 0;
+}
+
+/* Configure/autoconfigure the port */
+static void apbuart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_APBUART;
+		apbuart_request_port(port);
+	}
+}
+
+/* Verify the new serial_struct (for TIOCSSERIAL) */
+static int apbuart_verify_port(struct uart_port *port,
+			       struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
+		ret = -EINVAL;
+	if (ser->irq < 0 || ser->irq >= NR_IRQS)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops grlib_apbuart_ops = {
+	.tx_empty = apbuart_tx_empty,
+	.set_mctrl = apbuart_set_mctrl,
+	.get_mctrl = apbuart_get_mctrl,
+	.stop_tx = apbuart_stop_tx,
+	.start_tx = apbuart_start_tx,
+	.stop_rx = apbuart_stop_rx,
+	.break_ctl = apbuart_break_ctl,
+	.startup = apbuart_startup,
+	.shutdown = apbuart_shutdown,
+	.set_termios = apbuart_set_termios,
+	.type = apbuart_type,
+	.release_port = apbuart_release_port,
+	.request_port = apbuart_request_port,
+	.config_port = apbuart_config_port,
+	.verify_port = apbuart_verify_port,
+};
+
+static struct uart_port grlib_apbuart_ports[UART_NR];
+static struct device_node *grlib_apbuart_nodes[UART_NR];
+
+static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
+{
+	int ctrl, loop = 0;
+	int status;
+	int fifosize;
+	unsigned long flags;
+
+	ctrl = UART_GET_CTRL(port);
+
+	/*
+	 * Enable the transceiver and wait for it to be ready to send data.
+	 * Clear interrupts so that this process will not be externally
+	 * interrupted in the middle (which can cause the transceiver to
+	 * drain prematurely).
+	 */
+
+	local_irq_save(flags);
+
+	UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
+
+	while (!UART_TX_READY(UART_GET_STATUS(port)))
+		loop++;
+
+	/*
+	 * Disable the transceiver so data isn't actually sent during the
+	 * actual test.
+	 */
+
+	UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
+
+	fifosize = 1;
+	UART_PUT_CHAR(port, 0);
+
+	/*
+	 * So long as transmitting a character increments the tranceivier FIFO
+	 * length the FIFO must be at least that big. These bytes will
+	 * automatically drain off of the FIFO.
+	 */
+
+	status = UART_GET_STATUS(port);
+	while (((status >> 20) & 0x3F) == fifosize) {
+		fifosize++;
+		UART_PUT_CHAR(port, 0);
+		status = UART_GET_STATUS(port);
+	}
+
+	fifosize--;
+
+	UART_PUT_CTRL(port, ctrl);
+	local_irq_restore(flags);
+
+	if (fifosize == 0)
+		fifosize = 1;
+
+	return fifosize;
+}
+
+static void apbuart_flush_fifo(struct uart_port *port)
+{
+	int i;
+
+	for (i = 0; i < port->fifosize; i++)
+		UART_GET_CHAR(port);
+}
+
+
+/* ======================================================================== */
+/* Console driver, if enabled                                               */
+/* ======================================================================== */
+
+#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
+
+static void apbuart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned int status;
+	do {
+		status = UART_GET_STATUS(port);
+	} while (!UART_TX_READY(status));
+	UART_PUT_CHAR(port, ch);
+}
+
+static void
+apbuart_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_port *port = &grlib_apbuart_ports[co->index];
+	unsigned int status, old_cr, new_cr;
+
+	/* First save the CR then disable the interrupts */
+	old_cr = UART_GET_CTRL(port);
+	new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
+	UART_PUT_CTRL(port, new_cr);
+
+	uart_console_write(port, s, count, apbuart_console_putchar);
+
+	/*
+	 *      Finally, wait for transmitter to become empty
+	 *      and restore the TCR
+	 */
+	do {
+		status = UART_GET_STATUS(port);
+	} while (!UART_TX_READY(status));
+	UART_PUT_CTRL(port, old_cr);
+}
+
+static void __init
+apbuart_console_get_options(struct uart_port *port, int *baud,
+			    int *parity, int *bits)
+{
+	if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
+
+		unsigned int quot, status;
+		status = UART_GET_STATUS(port);
+
+		*parity = 'n';
+		if (status & UART_CTRL_PE) {
+			if ((status & UART_CTRL_PS) == 0)
+				*parity = 'e';
+			else
+				*parity = 'o';
+		}
+
+		*bits = 8;
+		quot = UART_GET_SCAL(port) / 8;
+		*baud = port->uartclk / (16 * (quot + 1));
+	}
+}
+
+static int __init apbuart_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 38400;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
+		 co, co->index, options);
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= grlib_apbuart_port_nr)
+		co->index = 0;
+
+	port = &grlib_apbuart_ports[co->index];
+
+	spin_lock_init(&port->lock);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		apbuart_console_get_options(port, &baud, &parity, &bits);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver grlib_apbuart_driver;
+
+static struct console grlib_apbuart_console = {
+	.name = "ttyS",
+	.write = apbuart_console_write,
+	.device = uart_console_device,
+	.setup = apbuart_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &grlib_apbuart_driver,
+};
+
+
+static int grlib_apbuart_configure(void);
+
+static int __init apbuart_console_init(void)
+{
+	if (grlib_apbuart_configure())
+		return -ENODEV;
+	register_console(&grlib_apbuart_console);
+	return 0;
+}
+
+console_initcall(apbuart_console_init);
+
+#define APBUART_CONSOLE	(&grlib_apbuart_console)
+#else
+#define APBUART_CONSOLE	NULL
+#endif
+
+static struct uart_driver grlib_apbuart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "serial",
+	.dev_name = "ttyS",
+	.major = SERIAL_APBUART_MAJOR,
+	.minor = SERIAL_APBUART_MINOR,
+	.nr = UART_NR,
+	.cons = APBUART_CONSOLE,
+};
+
+
+/* ======================================================================== */
+/* OF Platform Driver                                                       */
+/* ======================================================================== */
+
+static int apbuart_probe(struct platform_device *op)
+{
+	int i;
+	struct uart_port *port = NULL;
+
+	for (i = 0; i < grlib_apbuart_port_nr; i++) {
+		if (op->dev.of_node == grlib_apbuart_nodes[i])
+			break;
+	}
+
+	port = &grlib_apbuart_ports[i];
+	port->dev = &op->dev;
+	port->irq = op->archdata.irqs[0];
+
+	uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
+
+	apbuart_flush_fifo((struct uart_port *) port);
+
+	printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
+	       (unsigned long long) port->mapbase, port->irq);
+	return 0;
+}
+
+static const struct of_device_id apbuart_match[] = {
+	{
+	 .name = "GAISLER_APBUART",
+	 },
+	{
+	 .name = "01_00c",
+	 },
+	{},
+};
+MODULE_DEVICE_TABLE(of, apbuart_match);
+
+static struct platform_driver grlib_apbuart_of_driver = {
+	.probe = apbuart_probe,
+	.driver = {
+		.name = "grlib-apbuart",
+		.of_match_table = apbuart_match,
+	},
+};
+
+
+static int __init grlib_apbuart_configure(void)
+{
+	struct device_node *np;
+	int line = 0;
+
+	for_each_matching_node(np, apbuart_match) {
+		const int *ampopts;
+		const u32 *freq_hz;
+		const struct amba_prom_registers *regs;
+		struct uart_port *port;
+		unsigned long addr;
+
+		ampopts = of_get_property(np, "ampopts", NULL);
+		if (ampopts && (*ampopts == 0))
+			continue; /* Ignore if used by another OS instance */
+		regs = of_get_property(np, "reg", NULL);
+		/* Frequency of APB Bus is frequency of UART */
+		freq_hz = of_get_property(np, "freq", NULL);
+
+		if (!regs || !freq_hz || (*freq_hz == 0))
+			continue;
+
+		grlib_apbuart_nodes[line] = np;
+
+		addr = regs->phys_addr;
+
+		port = &grlib_apbuart_ports[line];
+
+		port->mapbase = addr;
+		port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
+		port->irq = 0;
+		port->iotype = UPIO_MEM;
+		port->ops = &grlib_apbuart_ops;
+		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE);
+		port->flags = UPF_BOOT_AUTOCONF;
+		port->line = line;
+		port->uartclk = *freq_hz;
+		port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
+		line++;
+
+		/* We support maximum UART_NR uarts ... */
+		if (line == UART_NR)
+			break;
+	}
+
+	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
+	return line ? 0 : -ENODEV;
+}
+
+static int __init grlib_apbuart_init(void)
+{
+	int ret;
+
+	/* Find all APBUARTS in device the tree and initialize their ports */
+	ret = grlib_apbuart_configure();
+	if (ret)
+		return ret;
+
+	printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
+
+	ret = uart_register_driver(&grlib_apbuart_driver);
+
+	if (ret) {
+		printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
+		       __FILE__, ret);
+		return ret;
+	}
+
+	ret = platform_driver_register(&grlib_apbuart_of_driver);
+	if (ret) {
+		printk(KERN_ERR
+		       "%s: platform_driver_register failed (%i)\n",
+		       __FILE__, ret);
+		uart_unregister_driver(&grlib_apbuart_driver);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void __exit grlib_apbuart_exit(void)
+{
+	int i;
+
+	for (i = 0; i < grlib_apbuart_port_nr; i++)
+		uart_remove_one_port(&grlib_apbuart_driver,
+				     &grlib_apbuart_ports[i]);
+
+	uart_unregister_driver(&grlib_apbuart_driver);
+	platform_driver_unregister(&grlib_apbuart_of_driver);
+}
+
+module_init(grlib_apbuart_init);
+module_exit(grlib_apbuart_exit);
+
+MODULE_AUTHOR("Aeroflex Gaisler AB");
+MODULE_DESCRIPTION("GRLIB APBUART serial driver");
+MODULE_VERSION("2.1");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/apbuart.h b/drivers/tty/serial/apbuart.h
new file mode 100644
index 000000000..81baf0076
--- /dev/null
+++ b/drivers/tty/serial/apbuart.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __GRLIB_APBUART_H__
+#define __GRLIB_APBUART_H__
+
+#include <asm/io.h>
+
+#define UART_NR		8
+static int grlib_apbuart_port_nr;
+
+struct grlib_apbuart_regs_map {
+	u32 data;
+	u32 status;
+	u32 ctrl;
+	u32 scaler;
+};
+
+struct amba_prom_registers {
+	unsigned int phys_addr;
+	unsigned int reg_size;
+};
+
+/*
+ *  The following defines the bits in the APBUART Status Registers.
+ */
+#define UART_STATUS_DR   0x00000001	/* Data Ready */
+#define UART_STATUS_TSE  0x00000002	/* TX Send Register Empty */
+#define UART_STATUS_THE  0x00000004	/* TX Hold Register Empty */
+#define UART_STATUS_BR   0x00000008	/* Break Error */
+#define UART_STATUS_OE   0x00000010	/* RX Overrun Error */
+#define UART_STATUS_PE   0x00000020	/* RX Parity Error */
+#define UART_STATUS_FE   0x00000040	/* RX Framing Error */
+#define UART_STATUS_ERR  0x00000078	/* Error Mask */
+
+/*
+ *  The following defines the bits in the APBUART Ctrl Registers.
+ */
+#define UART_CTRL_RE     0x00000001	/* Receiver enable */
+#define UART_CTRL_TE     0x00000002	/* Transmitter enable */
+#define UART_CTRL_RI     0x00000004	/* Receiver interrupt enable */
+#define UART_CTRL_TI     0x00000008	/* Transmitter irq */
+#define UART_CTRL_PS     0x00000010	/* Parity select */
+#define UART_CTRL_PE     0x00000020	/* Parity enable */
+#define UART_CTRL_FL     0x00000040	/* Flow control enable */
+#define UART_CTRL_LB     0x00000080	/* Loopback enable */
+
+#define APBBASE(port) ((struct grlib_apbuart_regs_map *)((port)->membase))
+
+#define APBBASE_DATA_P(port)	(&(APBBASE(port)->data))
+#define APBBASE_STATUS_P(port)	(&(APBBASE(port)->status))
+#define APBBASE_CTRL_P(port)	(&(APBBASE(port)->ctrl))
+#define APBBASE_SCALAR_P(port)	(&(APBBASE(port)->scaler))
+
+#define UART_GET_CHAR(port)	(__raw_readl(APBBASE_DATA_P(port)))
+#define UART_PUT_CHAR(port, v)	(__raw_writel(v, APBBASE_DATA_P(port)))
+#define UART_GET_STATUS(port)	(__raw_readl(APBBASE_STATUS_P(port)))
+#define UART_PUT_STATUS(port, v)(__raw_writel(v, APBBASE_STATUS_P(port)))
+#define UART_GET_CTRL(port)	(__raw_readl(APBBASE_CTRL_P(port)))
+#define UART_PUT_CTRL(port, v)	(__raw_writel(v, APBBASE_CTRL_P(port)))
+#define UART_GET_SCAL(port)	(__raw_readl(APBBASE_SCALAR_P(port)))
+#define UART_PUT_SCAL(port, v)	(__raw_writel(v, APBBASE_SCALAR_P(port)))
+
+#define UART_RX_DATA(s)		(((s) & UART_STATUS_DR) != 0)
+#define UART_TX_READY(s)	(((s) & UART_STATUS_THE) != 0)
+
+#endif /* __GRLIB_APBUART_H__ */
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
new file mode 100644
index 000000000..924c1a893
--- /dev/null
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -0,0 +1,888 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Atheros AR933X SoC built-in UART driver
+ *
+ *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+
+#include <asm/div64.h>
+
+#include <asm/mach-ath79/ar933x_uart.h>
+
+#include "serial_mctrl_gpio.h"
+
+#define DRIVER_NAME "ar933x-uart"
+
+#define AR933X_UART_MAX_SCALE	0xff
+#define AR933X_UART_MAX_STEP	0xffff
+
+#define AR933X_UART_MIN_BAUD	300
+#define AR933X_UART_MAX_BAUD	3000000
+
+#define AR933X_DUMMY_STATUS_RD	0x01
+
+static struct uart_driver ar933x_uart_driver;
+
+struct ar933x_uart_port {
+	struct uart_port	port;
+	unsigned int		ier;	/* shadow Interrupt Enable Register */
+	unsigned int		min_baud;
+	unsigned int		max_baud;
+	struct clk		*clk;
+	struct mctrl_gpios	*gpios;
+	struct gpio_desc	*rts_gpiod;
+};
+
+static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
+					    int offset)
+{
+	return readl(up->port.membase + offset);
+}
+
+static inline void ar933x_uart_write(struct ar933x_uart_port *up,
+				     int offset, unsigned int value)
+{
+	writel(value, up->port.membase + offset);
+}
+
+static inline void ar933x_uart_rmw(struct ar933x_uart_port *up,
+				  unsigned int offset,
+				  unsigned int mask,
+				  unsigned int val)
+{
+	unsigned int t;
+
+	t = ar933x_uart_read(up, offset);
+	t &= ~mask;
+	t |= val;
+	ar933x_uart_write(up, offset, t);
+}
+
+static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up,
+				       unsigned int offset,
+				       unsigned int val)
+{
+	ar933x_uart_rmw(up, offset, 0, val);
+}
+
+static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up,
+					 unsigned int offset,
+					 unsigned int val)
+{
+	ar933x_uart_rmw(up, offset, val, 0);
+}
+
+static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up)
+{
+	up->ier |= AR933X_UART_INT_TX_EMPTY;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
+static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
+{
+	up->ier &= ~AR933X_UART_INT_TX_EMPTY;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
+static inline void ar933x_uart_start_rx_interrupt(struct ar933x_uart_port *up)
+{
+	up->ier |= AR933X_UART_INT_RX_VALID;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
+static inline void ar933x_uart_stop_rx_interrupt(struct ar933x_uart_port *up)
+{
+	up->ier &= ~AR933X_UART_INT_RX_VALID;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
+static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
+{
+	unsigned int rdata;
+
+	rdata = ch & AR933X_UART_DATA_TX_RX_MASK;
+	rdata |= AR933X_UART_DATA_TX_CSR;
+	ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata);
+}
+
+static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+	unsigned long flags;
+	unsigned int rdata;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+	int ret = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	mctrl_gpio_get(up->gpios, &ret);
+
+	return ret;
+}
+
+static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	mctrl_gpio_set(up->gpios, mctrl);
+}
+
+static void ar933x_uart_start_tx(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	ar933x_uart_start_tx_interrupt(up);
+}
+
+static void ar933x_uart_wait_tx_complete(struct ar933x_uart_port *up)
+{
+	unsigned int status;
+	unsigned int timeout = 60000;
+
+	/* Wait up to 60ms for the character(s) to be sent. */
+	do {
+		status = ar933x_uart_read(up, AR933X_UART_CS_REG);
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	} while (status & AR933X_UART_CS_TX_BUSY);
+
+	if (timeout == 0)
+		dev_err(up->port.dev, "waiting for TX timed out\n");
+}
+
+static void ar933x_uart_rx_flush(struct ar933x_uart_port *up)
+{
+	unsigned int status;
+
+	/* clear RX_VALID interrupt */
+	ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_RX_VALID);
+
+	/* remove characters from the RX FIFO */
+	do {
+		ar933x_uart_write(up, AR933X_UART_DATA_REG, AR933X_UART_DATA_RX_CSR);
+		status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+	} while (status & AR933X_UART_DATA_RX_CSR);
+}
+
+static void ar933x_uart_stop_tx(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	ar933x_uart_stop_tx_interrupt(up);
+}
+
+static void ar933x_uart_stop_rx(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	ar933x_uart_stop_rx_interrupt(up);
+}
+
+static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (break_state == -1)
+		ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+				    AR933X_UART_CS_TX_BREAK);
+	else
+		ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
+				      AR933X_UART_CS_TX_BREAK);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/*
+ * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
+ */
+static unsigned long ar933x_uart_get_baud(unsigned int clk,
+					  unsigned int scale,
+					  unsigned int step)
+{
+	u64 t;
+	u32 div;
+
+	div = (2 << 16) * (scale + 1);
+	t = clk;
+	t *= step;
+	t += (div / 2);
+	do_div(t, div);
+
+	return t;
+}
+
+static void ar933x_uart_get_scale_step(unsigned int clk,
+				       unsigned int baud,
+				       unsigned int *scale,
+				       unsigned int *step)
+{
+	unsigned int tscale;
+	long min_diff;
+
+	*scale = 0;
+	*step = 0;
+
+	min_diff = baud;
+	for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
+		u64 tstep;
+		int diff;
+
+		tstep = baud * (tscale + 1);
+		tstep *= (2 << 16);
+		do_div(tstep, clk);
+
+		if (tstep > AR933X_UART_MAX_STEP)
+			break;
+
+		diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
+		if (diff < min_diff) {
+			min_diff = diff;
+			*scale = tscale;
+			*step = tstep;
+		}
+	}
+}
+
+static void ar933x_uart_set_termios(struct uart_port *port,
+				    struct ktermios *new,
+				    const struct ktermios *old)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+	unsigned int cs;
+	unsigned long flags;
+	unsigned int baud, scale, step;
+
+	/* Only CS8 is supported */
+	new->c_cflag &= ~CSIZE;
+	new->c_cflag |= CS8;
+
+	/* Only one stop bit is supported */
+	new->c_cflag &= ~CSTOPB;
+
+	cs = 0;
+	if (new->c_cflag & PARENB) {
+		if (!(new->c_cflag & PARODD))
+			cs |= AR933X_UART_CS_PARITY_EVEN;
+		else
+			cs |= AR933X_UART_CS_PARITY_ODD;
+	} else {
+		cs |= AR933X_UART_CS_PARITY_NONE;
+	}
+
+	/* Mark/space parity is not supported */
+	new->c_cflag &= ~CMSPAR;
+
+	baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
+	ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
+
+	/*
+	 * Ok, we're now changing the port state. Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/* disable the UART */
+	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
+		      AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
+
+	/* Update the per-port timeout. */
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	up->port.ignore_status_mask = 0;
+
+	/* ignore all characters if CREAD is not set */
+	if ((new->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;
+
+	ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
+			  scale << AR933X_UART_CLOCK_SCALE_S | step);
+
+	/* setup configuration register */
+	ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
+
+	/* enable host interrupt */
+	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+			    AR933X_UART_CS_HOST_INT_EN);
+
+	/* enable RX and TX ready overide */
+	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+		AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
+
+	/* reenable the UART */
+	ar933x_uart_rmw(up, AR933X_UART_CS_REG,
+			AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
+			AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	if (tty_termios_baud_rate(new))
+		tty_termios_encode_baud_rate(new, baud, baud);
+}
+
+static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
+{
+	struct tty_port *port = &up->port.state->port;
+	int max_count = 256;
+
+	do {
+		unsigned int rdata;
+		unsigned char ch;
+
+		rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+		if ((rdata & AR933X_UART_DATA_RX_CSR) == 0)
+			break;
+
+		/* remove the character from the FIFO */
+		ar933x_uart_write(up, AR933X_UART_DATA_REG,
+				  AR933X_UART_DATA_RX_CSR);
+
+		up->port.icount.rx++;
+		ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
+
+		if (uart_handle_sysrq_char(&up->port, ch))
+			continue;
+
+		if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
+			tty_insert_flip_char(port, ch, TTY_NORMAL);
+	} while (max_count-- > 0);
+
+	tty_flip_buffer_push(port);
+}
+
+static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	struct serial_rs485 *rs485conf = &up->port.rs485;
+	int count;
+	bool half_duplex_send = false;
+
+	if (uart_tx_stopped(&up->port))
+		return;
+
+	if ((rs485conf->flags & SER_RS485_ENABLED) &&
+	    (up->port.x_char || !uart_circ_empty(xmit))) {
+		ar933x_uart_stop_rx_interrupt(up);
+		gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_ON_SEND));
+		half_duplex_send = true;
+	}
+
+	count = up->port.fifosize;
+	do {
+		unsigned int rdata;
+
+		rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+		if ((rdata & AR933X_UART_DATA_TX_CSR) == 0)
+			break;
+
+		if (up->port.x_char) {
+			ar933x_uart_putc(up, up->port.x_char);
+			up->port.icount.tx++;
+			up->port.x_char = 0;
+			continue;
+		}
+
+		if (uart_circ_empty(xmit))
+			break;
+
+		ar933x_uart_putc(up, xmit->buf[xmit->tail]);
+
+		uart_xmit_advance(&up->port, 1);
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (!uart_circ_empty(xmit)) {
+		ar933x_uart_start_tx_interrupt(up);
+	} else if (half_duplex_send) {
+		ar933x_uart_wait_tx_complete(up);
+		ar933x_uart_rx_flush(up);
+		ar933x_uart_start_rx_interrupt(up);
+		gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND));
+	}
+}
+
+static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
+{
+	struct ar933x_uart_port *up = dev_id;
+	unsigned int status;
+
+	status = ar933x_uart_read(up, AR933X_UART_CS_REG);
+	if ((status & AR933X_UART_CS_HOST_INT) == 0)
+		return IRQ_NONE;
+
+	spin_lock(&up->port.lock);
+
+	status = ar933x_uart_read(up, AR933X_UART_INT_REG);
+	status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
+
+	if (status & AR933X_UART_INT_RX_VALID) {
+		ar933x_uart_write(up, AR933X_UART_INT_REG,
+				  AR933X_UART_INT_RX_VALID);
+		ar933x_uart_rx_chars(up);
+	}
+
+	if (status & AR933X_UART_INT_TX_EMPTY) {
+		ar933x_uart_write(up, AR933X_UART_INT_REG,
+				  AR933X_UART_INT_TX_EMPTY);
+		ar933x_uart_stop_tx_interrupt(up);
+		ar933x_uart_tx_chars(up);
+	}
+
+	spin_unlock(&up->port.lock);
+
+	return IRQ_HANDLED;
+}
+
+static int ar933x_uart_startup(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+	unsigned long flags;
+	int ret;
+
+	ret = request_irq(up->port.irq, ar933x_uart_interrupt,
+			  up->port.irqflags, dev_name(up->port.dev), up);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/* Enable HOST interrupts */
+	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+			    AR933X_UART_CS_HOST_INT_EN);
+
+	/* enable RX and TX ready overide */
+	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+		AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
+
+	/* Enable RX interrupts */
+	ar933x_uart_start_rx_interrupt(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return 0;
+}
+
+static void ar933x_uart_shutdown(struct uart_port *port)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	/* Disable all interrupts */
+	up->ier = 0;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+
+	/* Disable break condition */
+	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
+			      AR933X_UART_CS_TX_BREAK);
+
+	free_irq(up->port.irq, up);
+}
+
+static const char *ar933x_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_AR933X) ? "AR933X UART" : NULL;
+}
+
+static void ar933x_uart_release_port(struct uart_port *port)
+{
+	/* Nothing to release ... */
+}
+
+static int ar933x_uart_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+static void ar933x_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_AR933X;
+}
+
+static int ar933x_uart_verify_port(struct uart_port *port,
+				   struct serial_struct *ser)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	if (ser->type != PORT_UNKNOWN &&
+	    ser->type != PORT_AR933X)
+		return -EINVAL;
+
+	if (ser->irq < 0 || ser->irq >= NR_IRQS)
+		return -EINVAL;
+
+	if (ser->baud_base < up->min_baud ||
+	    ser->baud_base > up->max_baud)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops ar933x_uart_ops = {
+	.tx_empty	= ar933x_uart_tx_empty,
+	.set_mctrl	= ar933x_uart_set_mctrl,
+	.get_mctrl	= ar933x_uart_get_mctrl,
+	.stop_tx	= ar933x_uart_stop_tx,
+	.start_tx	= ar933x_uart_start_tx,
+	.stop_rx	= ar933x_uart_stop_rx,
+	.break_ctl	= ar933x_uart_break_ctl,
+	.startup	= ar933x_uart_startup,
+	.shutdown	= ar933x_uart_shutdown,
+	.set_termios	= ar933x_uart_set_termios,
+	.type		= ar933x_uart_type,
+	.release_port	= ar933x_uart_release_port,
+	.request_port	= ar933x_uart_request_port,
+	.config_port	= ar933x_uart_config_port,
+	.verify_port	= ar933x_uart_verify_port,
+};
+
+static int ar933x_config_rs485(struct uart_port *port, struct ktermios *termios,
+				struct serial_rs485 *rs485conf)
+{
+	struct ar933x_uart_port *up =
+			container_of(port, struct ar933x_uart_port, port);
+
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		gpiod_set_value(up->rts_gpiod,
+			!!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND));
+
+	return 0;
+}
+
+#ifdef CONFIG_SERIAL_AR933X_CONSOLE
+static struct ar933x_uart_port *
+ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
+
+static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up)
+{
+	unsigned int status;
+	unsigned int timeout = 60000;
+
+	/* Wait up to 60ms for the character(s) to be sent. */
+	do {
+		status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	} while ((status & AR933X_UART_DATA_TX_CSR) == 0);
+}
+
+static void ar933x_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	ar933x_uart_wait_xmitr(up);
+	ar933x_uart_putc(up, ch);
+}
+
+static void ar933x_uart_console_write(struct console *co, const char *s,
+				      unsigned int count)
+{
+	struct ar933x_uart_port *up = ar933x_console_ports[co->index];
+	unsigned long flags;
+	unsigned int int_en;
+	int locked = 1;
+
+	local_irq_save(flags);
+
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&up->port.lock);
+	else
+		spin_lock(&up->port.lock);
+
+	/*
+	 * First save the IER then disable the interrupts
+	 */
+	int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0);
+
+	uart_console_write(&up->port, s, count, ar933x_uart_console_putchar);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore the IER
+	 */
+	ar933x_uart_wait_xmitr(up);
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en);
+
+	ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+
+	local_irq_restore(flags);
+}
+
+static int ar933x_uart_console_setup(struct console *co, char *options)
+{
+	struct ar933x_uart_port *up;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS)
+		return -EINVAL;
+
+	up = ar933x_console_ports[co->index];
+	if (!up)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&up->port, co, baud, parity, bits, flow);
+}
+
+static struct console ar933x_uart_console = {
+	.name		= "ttyATH",
+	.write		= ar933x_uart_console_write,
+	.device		= uart_console_device,
+	.setup		= ar933x_uart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &ar933x_uart_driver,
+};
+#endif /* CONFIG_SERIAL_AR933X_CONSOLE */
+
+static struct uart_driver ar933x_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= "ttyATH",
+	.nr		= CONFIG_SERIAL_AR933X_NR_UARTS,
+	.cons		= NULL, /* filled in runtime */
+};
+
+static const struct serial_rs485 ar933x_no_rs485 = {};
+static const struct serial_rs485 ar933x_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
+};
+
+static int ar933x_uart_probe(struct platform_device *pdev)
+{
+	struct ar933x_uart_port *up;
+	struct uart_port *port;
+	struct resource *mem_res;
+	struct device_node *np;
+	unsigned int baud;
+	int id;
+	int ret;
+	int irq;
+
+	np = pdev->dev.of_node;
+	if (IS_ENABLED(CONFIG_OF) && np) {
+		id = of_alias_get_id(np, "serial");
+		if (id < 0) {
+			dev_err(&pdev->dev, "unable to get alias id, err=%d\n",
+				id);
+			return id;
+		}
+	} else {
+		id = pdev->id;
+		if (id == -1)
+			id = 0;
+	}
+
+	if (id >= CONFIG_SERIAL_AR933X_NR_UARTS)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
+			  GFP_KERNEL);
+	if (!up)
+		return -ENOMEM;
+
+	up->clk = devm_clk_get(&pdev->dev, "uart");
+	if (IS_ERR(up->clk)) {
+		dev_err(&pdev->dev, "unable to get UART clock\n");
+		return PTR_ERR(up->clk);
+	}
+
+	port = &up->port;
+
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &mem_res);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+
+	ret = clk_prepare_enable(up->clk);
+	if (ret)
+		return ret;
+
+	port->uartclk = clk_get_rate(up->clk);
+	if (!port->uartclk) {
+		ret = -EINVAL;
+		goto err_disable_clk;
+	}
+
+	port->mapbase = mem_res->start;
+	port->line = id;
+	port->irq = irq;
+	port->dev = &pdev->dev;
+	port->type = PORT_AR933X;
+	port->iotype = UPIO_MEM32;
+
+	port->regshift = 2;
+	port->fifosize = AR933X_UART_FIFO_SIZE;
+	port->ops = &ar933x_uart_ops;
+	port->rs485_config = ar933x_config_rs485;
+	port->rs485_supported = ar933x_rs485_supported;
+
+	baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
+	up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
+
+	baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
+	up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
+
+	ret = uart_get_rs485_mode(port);
+	if (ret)
+		goto err_disable_clk;
+
+	up->gpios = mctrl_gpio_init(port, 0);
+	if (IS_ERR(up->gpios) && PTR_ERR(up->gpios) != -ENOSYS) {
+		ret = PTR_ERR(up->gpios);
+		goto err_disable_clk;
+	}
+
+	up->rts_gpiod = mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS);
+
+	if (!up->rts_gpiod) {
+		port->rs485_supported = ar933x_no_rs485;
+		if (port->rs485.flags & SER_RS485_ENABLED) {
+			dev_err(&pdev->dev, "lacking rts-gpio, disabling RS485\n");
+			port->rs485.flags &= ~SER_RS485_ENABLED;
+		}
+	}
+
+#ifdef CONFIG_SERIAL_AR933X_CONSOLE
+	ar933x_console_ports[up->port.line] = up;
+#endif
+
+	ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
+	if (ret)
+		goto err_disable_clk;
+
+	platform_set_drvdata(pdev, up);
+	return 0;
+
+err_disable_clk:
+	clk_disable_unprepare(up->clk);
+	return ret;
+}
+
+static int ar933x_uart_remove(struct platform_device *pdev)
+{
+	struct ar933x_uart_port *up;
+
+	up = platform_get_drvdata(pdev);
+
+	if (up) {
+		uart_remove_one_port(&ar933x_uart_driver, &up->port);
+		clk_disable_unprepare(up->clk);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ar933x_uart_of_ids[] = {
+	{ .compatible = "qca,ar9330-uart" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ar933x_uart_of_ids);
+#endif
+
+static struct platform_driver ar933x_uart_platform_driver = {
+	.probe		= ar933x_uart_probe,
+	.remove		= ar933x_uart_remove,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.of_match_table = of_match_ptr(ar933x_uart_of_ids),
+	},
+};
+
+static int __init ar933x_uart_init(void)
+{
+	int ret;
+
+#ifdef CONFIG_SERIAL_AR933X_CONSOLE
+	ar933x_uart_driver.cons = &ar933x_uart_console;
+#endif
+
+	ret = uart_register_driver(&ar933x_uart_driver);
+	if (ret)
+		goto err_out;
+
+	ret = platform_driver_register(&ar933x_uart_platform_driver);
+	if (ret)
+		goto err_unregister_uart_driver;
+
+	return 0;
+
+err_unregister_uart_driver:
+	uart_unregister_driver(&ar933x_uart_driver);
+err_out:
+	return ret;
+}
+
+static void __exit ar933x_uart_exit(void)
+{
+	platform_driver_unregister(&ar933x_uart_platform_driver);
+	uart_unregister_driver(&ar933x_uart_driver);
+}
+
+module_init(ar933x_uart_init);
+module_exit(ar933x_uart_exit);
+
+MODULE_DESCRIPTION("Atheros AR933X UART driver");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
new file mode 100644
index 000000000..ad4ae19b6
--- /dev/null
+++ b/drivers/tty/serial/arc_uart.c
@@ -0,0 +1,673 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARC On-Chip(fpga) UART Driver
+ *
+ * Copyright (C) 2010-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * vineetg: July 10th 2012
+ *  -Decoupled the driver from arch/arc
+ *    +Using platform_get_resource() for irq/membase (thx to bfin_uart.c)
+ *    +Using early_platform_xxx() for early console (thx to mach-shmobile/xxx)
+ *
+ * Vineetg: Aug 21st 2010
+ *  -Is uart_tx_stopped() not done in tty write path as it has already been
+ *   taken care of, in serial core
+ *
+ * Vineetg: Aug 18th 2010
+ *  -New Serial Core based ARC UART driver
+ *  -Derived largely from blackfin driver albiet with some major tweaks
+ *
+ * TODO:
+ *  -check if sysreq works
+ */
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+
+/*************************************
+ * ARC UART Hardware Specs
+ ************************************/
+#define ARC_UART_TX_FIFO_SIZE  1
+
+/*
+ * UART Register set (this is not a Standards Compliant IP)
+ * Also each reg is Word aligned, but only 8 bits wide
+ */
+#define R_ID0	0
+#define R_ID1	4
+#define R_ID2	8
+#define R_ID3	12
+#define R_DATA	16
+#define R_STS	20
+#define R_BAUDL	24
+#define R_BAUDH	28
+
+/* Bits for UART Status Reg (R/W) */
+#define RXIENB  0x04	/* Receive Interrupt Enable */
+#define TXIENB  0x40	/* Transmit Interrupt Enable */
+
+#define RXEMPTY 0x20	/* Receive FIFO Empty: No char receivede */
+#define TXEMPTY 0x80	/* Transmit FIFO Empty, thus char can be written into */
+
+#define RXFULL  0x08	/* Receive FIFO full */
+#define RXFULL1 0x10	/* Receive FIFO has space for 1 char (tot space=4) */
+
+#define RXFERR  0x01	/* Frame Error: Stop Bit not detected */
+#define RXOERR  0x02	/* OverFlow Err: Char recv but RXFULL still set */
+
+/* Uart bit fiddling helpers: lowest level */
+#define RBASE(port, reg)      (port->membase + reg)
+#define UART_REG_SET(u, r, v) writeb((v), RBASE(u, r))
+#define UART_REG_GET(u, r)    readb(RBASE(u, r))
+
+#define UART_REG_OR(u, r, v)  UART_REG_SET(u, r, UART_REG_GET(u, r) | (v))
+#define UART_REG_CLR(u, r, v) UART_REG_SET(u, r, UART_REG_GET(u, r) & ~(v))
+
+/* Uart bit fiddling helpers: API level */
+#define UART_SET_DATA(uart, val)   UART_REG_SET(uart, R_DATA, val)
+#define UART_GET_DATA(uart)        UART_REG_GET(uart, R_DATA)
+
+#define UART_SET_BAUDH(uart, val)  UART_REG_SET(uart, R_BAUDH, val)
+#define UART_SET_BAUDL(uart, val)  UART_REG_SET(uart, R_BAUDL, val)
+
+#define UART_CLR_STATUS(uart, val) UART_REG_CLR(uart, R_STS, val)
+#define UART_GET_STATUS(uart)      UART_REG_GET(uart, R_STS)
+
+#define UART_ALL_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, RXIENB|TXIENB)
+#define UART_RX_IRQ_DISABLE(uart)  UART_REG_CLR(uart, R_STS, RXIENB)
+#define UART_TX_IRQ_DISABLE(uart)  UART_REG_CLR(uart, R_STS, TXIENB)
+
+#define UART_ALL_IRQ_ENABLE(uart)  UART_REG_OR(uart, R_STS, RXIENB|TXIENB)
+#define UART_RX_IRQ_ENABLE(uart)   UART_REG_OR(uart, R_STS, RXIENB)
+#define UART_TX_IRQ_ENABLE(uart)   UART_REG_OR(uart, R_STS, TXIENB)
+
+#define ARC_SERIAL_DEV_NAME	"ttyARC"
+
+struct arc_uart_port {
+	struct uart_port port;
+	unsigned long baud;
+};
+
+#define to_arc_port(uport)  container_of(uport, struct arc_uart_port, port)
+
+static struct arc_uart_port arc_uart_ports[CONFIG_SERIAL_ARC_NR_PORTS];
+
+#ifdef CONFIG_SERIAL_ARC_CONSOLE
+static struct console arc_console;
+#endif
+
+#define DRIVER_NAME	"arc-uart"
+
+static struct uart_driver arc_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= ARC_SERIAL_DEV_NAME,
+	.major		= 0,
+	.minor		= 0,
+	.nr		= CONFIG_SERIAL_ARC_NR_PORTS,
+#ifdef CONFIG_SERIAL_ARC_CONSOLE
+	.cons		= &arc_console,
+#endif
+};
+
+static void arc_serial_stop_rx(struct uart_port *port)
+{
+	UART_RX_IRQ_DISABLE(port);
+}
+
+static void arc_serial_stop_tx(struct uart_port *port)
+{
+	while (!(UART_GET_STATUS(port) & TXEMPTY))
+		cpu_relax();
+
+	UART_TX_IRQ_DISABLE(port);
+}
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int arc_serial_tx_empty(struct uart_port *port)
+{
+	unsigned int stat;
+
+	stat = UART_GET_STATUS(port);
+	if (stat & TXEMPTY)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+/*
+ * Driver internal routine, used by both tty(serial core) as well as tx-isr
+ *  -Called under spinlock in either cases
+ *  -also tty->flow.stopped has already been checked
+ *     = by uart_start( ) before calling us
+ *     = tx_ist checks that too before calling
+ */
+static void arc_serial_tx_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	int sent = 0;
+	unsigned char ch;
+
+	if (unlikely(port->x_char)) {
+		UART_SET_DATA(port, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		sent = 1;
+	} else if (!uart_circ_empty(xmit)) {
+		ch = xmit->buf[xmit->tail];
+		uart_xmit_advance(port, 1);
+		while (!(UART_GET_STATUS(port) & TXEMPTY))
+			cpu_relax();
+		UART_SET_DATA(port, ch);
+		sent = 1;
+	}
+
+	/*
+	 * If num chars in xmit buffer are too few, ask tty layer for more.
+	 * By Hard ISR to schedule processing in software interrupt part
+	 */
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (sent)
+		UART_TX_IRQ_ENABLE(port);
+}
+
+/*
+ * port is locked and interrupts are disabled
+ * uart_start( ) calls us under the port spinlock irqsave
+ */
+static void arc_serial_start_tx(struct uart_port *port)
+{
+	arc_serial_tx_chars(port);
+}
+
+static void arc_serial_rx_chars(struct uart_port *port, unsigned int status)
+{
+	/*
+	 * UART has 4 deep RX-FIFO. Driver's recongnition of this fact
+	 * is very subtle. Here's how ...
+	 * Upon getting a RX-Intr, such that RX-EMPTY=0, meaning data available,
+	 * driver reads the DATA Reg and keeps doing that in a loop, until
+	 * RX-EMPTY=1. Multiple chars being avail, with a single Interrupt,
+	 * before RX-EMPTY=0, implies some sort of buffering going on in the
+	 * controller, which is indeed the Rx-FIFO.
+	 */
+	do {
+		u8 ch, flg = TTY_NORMAL;
+
+		/*
+		 * This could be an Rx Intr for err (no data),
+		 * so check err and clear that Intr first
+		 */
+		if (status & RXOERR) {
+			port->icount.overrun++;
+			flg = TTY_OVERRUN;
+			UART_CLR_STATUS(port, RXOERR);
+		}
+
+		if (status & RXFERR) {
+			port->icount.frame++;
+			flg = TTY_FRAME;
+			UART_CLR_STATUS(port, RXFERR);
+		}
+
+		if (status & RXEMPTY)
+			continue;
+
+		ch = UART_GET_DATA(port);
+		port->icount.rx++;
+
+		if (!(uart_handle_sysrq_char(port, ch)))
+			uart_insert_char(port, status, RXOERR, ch, flg);
+
+		tty_flip_buffer_push(&port->state->port);
+	} while (!((status = UART_GET_STATUS(port)) & RXEMPTY));
+}
+
+/*
+ * A note on the Interrupt handling state machine of this driver
+ *
+ * kernel printk writes funnel thru the console driver framework and in order
+ * to keep things simple as well as efficient, it writes to UART in polled
+ * mode, in one shot, and exits.
+ *
+ * OTOH, Userland output (via tty layer), uses interrupt based writes as there
+ * can be undeterministic delay between char writes.
+ *
+ * Thus Rx-interrupts are always enabled, while tx-interrupts are by default
+ * disabled.
+ *
+ * When tty has some data to send out, serial core calls driver's start_tx
+ * which
+ *   -checks-if-tty-buffer-has-char-to-send
+ *   -writes-data-to-uart
+ *   -enable-tx-intr
+ *
+ * Once data bits are pushed out, controller raises the Tx-room-avail-Interrupt.
+ * The first thing Tx ISR does is disable further Tx interrupts (as this could
+ * be the last char to send, before settling down into the quiet polled mode).
+ * It then calls the exact routine used by tty layer write to send out any
+ * more char in tty buffer. In case of sending, it re-enables Tx-intr. In case
+ * of no data, it remains disabled.
+ * This is how the transmit state machine is dynamically switched on/off
+ */
+
+static irqreturn_t arc_serial_isr(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned int status;
+
+	status = UART_GET_STATUS(port);
+
+	/*
+	 * Single IRQ for both Rx (data available) Tx (room available) Interrupt
+	 * notifications from the UART Controller.
+	 * To demultiplex between the two, we check the relevant bits
+	 */
+	if (status & RXIENB) {
+
+		/* already in ISR, no need of xx_irqsave */
+		spin_lock(&port->lock);
+		arc_serial_rx_chars(port, status);
+		spin_unlock(&port->lock);
+	}
+
+	if ((status & TXIENB) && (status & TXEMPTY)) {
+
+		/* Unconditionally disable further Tx-Interrupts.
+		 * will be enabled by tx_chars() if needed.
+		 */
+		UART_TX_IRQ_DISABLE(port);
+
+		spin_lock(&port->lock);
+
+		if (!uart_tx_stopped(port))
+			arc_serial_tx_chars(port);
+
+		spin_unlock(&port->lock);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int arc_serial_get_mctrl(struct uart_port *port)
+{
+	/*
+	 * Pretend we have a Modem status reg and following bits are
+	 *  always set, to satify the serial core state machine
+	 *  (DSR) Data Set Ready
+	 *  (CTS) Clear To Send
+	 *  (CAR) Carrier Detect
+	 */
+	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void arc_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* MCR not present */
+}
+
+static void arc_serial_break_ctl(struct uart_port *port, int break_state)
+{
+	/* ARC UART doesn't support sending Break signal */
+}
+
+static int arc_serial_startup(struct uart_port *port)
+{
+	/* Before we hook up the ISR, Disable all UART Interrupts */
+	UART_ALL_IRQ_DISABLE(port);
+
+	if (request_irq(port->irq, arc_serial_isr, 0, "arc uart rx-tx", port)) {
+		dev_warn(port->dev, "Unable to attach ARC UART intr\n");
+		return -EBUSY;
+	}
+
+	UART_RX_IRQ_ENABLE(port); /* Only Rx IRQ enabled to begin with */
+
+	return 0;
+}
+
+/* This is not really needed */
+static void arc_serial_shutdown(struct uart_port *port)
+{
+	free_irq(port->irq, port);
+}
+
+static void
+arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
+		       const struct ktermios *old)
+{
+	struct arc_uart_port *uart = to_arc_port(port);
+	unsigned int baud, uartl, uarth, hw_val;
+	unsigned long flags;
+
+	/*
+	 * Use the generic handler so that any specially encoded baud rates
+	 * such as SPD_xx flags or "%B0" can be handled
+	 * Max Baud I suppose will not be more than current 115K * 4
+	 * Formula for ARC UART is: hw-val = ((CLK/(BAUD*4)) -1)
+	 * spread over two 8-bit registers
+	 */
+	baud = uart_get_baud_rate(port, new, old, 0, 460800);
+
+	hw_val = port->uartclk / (uart->baud * 4) - 1;
+	uartl = hw_val & 0xFF;
+	uarth = (hw_val >> 8) & 0xFF;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	UART_ALL_IRQ_DISABLE(port);
+
+	UART_SET_BAUDL(port, uartl);
+	UART_SET_BAUDH(port, uarth);
+
+	UART_RX_IRQ_ENABLE(port);
+
+	/*
+	 * UART doesn't support Parity/Hardware Flow Control;
+	 * Only supports 8N1 character size
+	 */
+	new->c_cflag &= ~(CMSPAR|CRTSCTS|CSIZE);
+	new->c_cflag |= CS8;
+
+	if (old)
+		tty_termios_copy_hw(new, old);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(new))
+		tty_termios_encode_baud_rate(new, baud, baud);
+
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *arc_serial_type(struct uart_port *port)
+{
+	return port->type == PORT_ARC ? DRIVER_NAME : NULL;
+}
+
+static void arc_serial_release_port(struct uart_port *port)
+{
+}
+
+static int arc_serial_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int
+arc_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (port->type != PORT_UNKNOWN && ser->type != PORT_ARC)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void arc_serial_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_ARC;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static void arc_serial_poll_putchar(struct uart_port *port, unsigned char chr)
+{
+	while (!(UART_GET_STATUS(port) & TXEMPTY))
+		cpu_relax();
+
+	UART_SET_DATA(port, chr);
+}
+
+static int arc_serial_poll_getchar(struct uart_port *port)
+{
+	unsigned char chr;
+
+	while (!(UART_GET_STATUS(port) & RXEMPTY))
+		cpu_relax();
+
+	chr = UART_GET_DATA(port);
+	return chr;
+}
+#endif
+
+static const struct uart_ops arc_serial_pops = {
+	.tx_empty	= arc_serial_tx_empty,
+	.set_mctrl	= arc_serial_set_mctrl,
+	.get_mctrl	= arc_serial_get_mctrl,
+	.stop_tx	= arc_serial_stop_tx,
+	.start_tx	= arc_serial_start_tx,
+	.stop_rx	= arc_serial_stop_rx,
+	.break_ctl	= arc_serial_break_ctl,
+	.startup	= arc_serial_startup,
+	.shutdown	= arc_serial_shutdown,
+	.set_termios	= arc_serial_set_termios,
+	.type		= arc_serial_type,
+	.release_port	= arc_serial_release_port,
+	.request_port	= arc_serial_request_port,
+	.config_port	= arc_serial_config_port,
+	.verify_port	= arc_serial_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_put_char = arc_serial_poll_putchar,
+	.poll_get_char = arc_serial_poll_getchar,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_ARC_CONSOLE
+
+static int arc_serial_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= CONFIG_SERIAL_ARC_NR_PORTS)
+		return -ENODEV;
+
+	/*
+	 * The uart port backing the console (e.g. ttyARC1) might not have been
+	 * init yet. If so, defer the console setup to after the port.
+	 */
+	port = &arc_uart_ports[co->index].port;
+	if (!port->membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	/*
+	 * Serial core will call port->ops->set_termios( )
+	 * which will set the baud reg
+	 */
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static void arc_serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (!(UART_GET_STATUS(port) & TXEMPTY))
+		cpu_relax();
+
+	UART_SET_DATA(port, (unsigned char)ch);
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void arc_serial_console_write(struct console *co, const char *s,
+				     unsigned int count)
+{
+	struct uart_port *port = &arc_uart_ports[co->index].port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_console_write(port, s, count, arc_serial_console_putchar);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static struct console arc_console = {
+	.name	= ARC_SERIAL_DEV_NAME,
+	.write	= arc_serial_console_write,
+	.device	= uart_console_device,
+	.setup	= arc_serial_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &arc_uart_driver
+};
+
+static void arc_early_serial_write(struct console *con, const char *s,
+				   unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, arc_serial_console_putchar);
+}
+
+static int __init arc_early_console_setup(struct earlycon_device *dev,
+					  const char *opt)
+{
+	struct uart_port *port = &dev->port;
+	unsigned int l, h, hw_val;
+
+	if (!dev->port.membase)
+		return -ENODEV;
+
+	hw_val = port->uartclk / (dev->baud * 4) - 1;
+	l = hw_val & 0xFF;
+	h = (hw_val >> 8) & 0xFF;
+
+	UART_SET_BAUDL(port, l);
+	UART_SET_BAUDH(port, h);
+
+	dev->con->write = arc_early_serial_write;
+	return 0;
+}
+OF_EARLYCON_DECLARE(arc_uart, "snps,arc-uart", arc_early_console_setup);
+
+#endif	/* CONFIG_SERIAL_ARC_CONSOLE */
+
+static int arc_serial_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct arc_uart_port *uart;
+	struct uart_port *port;
+	int dev_id;
+	u32 val;
+
+	/* no device tree device */
+	if (!np)
+		return -ENODEV;
+
+	dev_id = of_alias_get_id(np, "serial");
+	if (dev_id < 0)
+		dev_id = 0;
+
+	if (dev_id >= ARRAY_SIZE(arc_uart_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n", dev_id);
+		return -EINVAL;
+	}
+
+	uart = &arc_uart_ports[dev_id];
+	port = &uart->port;
+
+	if (of_property_read_u32(np, "clock-frequency", &val)) {
+		dev_err(&pdev->dev, "clock-frequency property NOTset\n");
+		return -EINVAL;
+	}
+	port->uartclk = val;
+
+	if (of_property_read_u32(np, "current-speed", &val)) {
+		dev_err(&pdev->dev, "current-speed property NOT set\n");
+		return -EINVAL;
+	}
+	uart->baud = val;
+
+	port->membase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(port->membase)) {
+		/* No point of dev_err since UART itself is hosed here */
+		return PTR_ERR(port->membase);
+	}
+
+	port->irq = irq_of_parse_and_map(np, 0);
+
+	port->dev = &pdev->dev;
+	port->iotype = UPIO_MEM;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->line = dev_id;
+	port->ops = &arc_serial_pops;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ARC_CONSOLE);
+
+	port->fifosize = ARC_UART_TX_FIFO_SIZE;
+
+	/*
+	 * uart_insert_char( ) uses it in decideding whether to ignore a
+	 * char or not. Explicitly setting it here, removes the subtelty
+	 */
+	port->ignore_status_mask = 0;
+
+	return uart_add_one_port(&arc_uart_driver, &arc_uart_ports[dev_id].port);
+}
+
+static const struct of_device_id arc_uart_dt_ids[] = {
+	{ .compatible = "snps,arc-uart" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
+
+static struct platform_driver arc_platform_driver = {
+	.probe = arc_serial_probe,
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table  = arc_uart_dt_ids,
+	 },
+};
+
+static int __init arc_serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&arc_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&arc_platform_driver);
+	if (ret)
+		uart_unregister_driver(&arc_uart_driver);
+
+	return ret;
+}
+
+static void __exit arc_serial_exit(void)
+{
+	platform_driver_unregister(&arc_platform_driver);
+	uart_unregister_driver(&arc_uart_driver);
+}
+
+module_init(arc_serial_init);
+module_exit(arc_serial_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("Vineet Gupta");
+MODULE_DESCRIPTION("ARC(Synopsys) On-Chip(fpga) serial driver");
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
new file mode 100644
index 000000000..88cdafa5a
--- /dev/null
+++ b/drivers/tty/serial/atmel_serial.c
@@ -0,0 +1,3054 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for Atmel AT91 Serial ports
+ *  Copyright (C) 2003 Rick Bronson
+ *
+ *  Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  DMA support added by Chip Coldwell.
+ */
+#include <linux/circ_buf.h>
+#include <linux/tty.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/tty_flip.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/atmel_pdc.h>
+#include <linux/uaccess.h>
+#include <linux/platform_data/atmel.h>
+#include <linux/timer.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/suspend.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+
+#include <asm/div64.h>
+#include <asm/ioctls.h>
+
+#define PDC_BUFFER_SIZE		512
+/* Revisit: We should calculate this based on the actual port settings */
+#define PDC_RX_TIMEOUT		(3 * 10)		/* 3 bytes */
+
+/* The minium number of data FIFOs should be able to contain */
+#define ATMEL_MIN_FIFO_SIZE	8
+/*
+ * These two offsets are substracted from the RX FIFO size to define the RTS
+ * high and low thresholds
+ */
+#define ATMEL_RTS_HIGH_OFFSET	16
+#define ATMEL_RTS_LOW_OFFSET	20
+
+#include <linux/serial_core.h>
+
+#include "serial_mctrl_gpio.h"
+#include "atmel_serial.h"
+
+static void atmel_start_rx(struct uart_port *port);
+static void atmel_stop_rx(struct uart_port *port);
+
+#ifdef CONFIG_SERIAL_ATMEL_TTYAT
+
+/* Use device name ttyAT, major 204 and minor 154-169.  This is necessary if we
+ * should coexist with the 8250 driver, such as if we have an external 16C550
+ * UART. */
+#define SERIAL_ATMEL_MAJOR	204
+#define MINOR_START		154
+#define ATMEL_DEVICENAME	"ttyAT"
+
+#else
+
+/* Use device name ttyS, major 4, minor 64-68.  This is the usual serial port
+ * name, but it is legally reserved for the 8250 driver. */
+#define SERIAL_ATMEL_MAJOR	TTY_MAJOR
+#define MINOR_START		64
+#define ATMEL_DEVICENAME	"ttyS"
+
+#endif
+
+#define ATMEL_ISR_PASS_LIMIT	256
+
+struct atmel_dma_buffer {
+	unsigned char	*buf;
+	dma_addr_t	dma_addr;
+	unsigned int	dma_size;
+	unsigned int	ofs;
+};
+
+struct atmel_uart_char {
+	u16		status;
+	u16		ch;
+};
+
+/*
+ * Be careful, the real size of the ring buffer is
+ * sizeof(atmel_uart_char) * ATMEL_SERIAL_RINGSIZE. It means that ring buffer
+ * can contain up to 1024 characters in PIO mode and up to 4096 characters in
+ * DMA mode.
+ */
+#define ATMEL_SERIAL_RINGSIZE 1024
+
+/*
+ * at91: 6 USARTs and one DBGU port (SAM9260)
+ * samx7: 3 USARTs and 5 UARTs
+ */
+#define ATMEL_MAX_UART		8
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct atmel_uart_port {
+	struct uart_port	uart;		/* uart */
+	struct clk		*clk;		/* uart clock */
+	struct clk		*gclk;		/* uart generic clock */
+	int			may_wakeup;	/* cached value of device_may_wakeup for times we need to disable it */
+	u32			backup_imr;	/* IMR saved during suspend */
+	int			break_active;	/* break being received */
+
+	bool			use_dma_rx;	/* enable DMA receiver */
+	bool			use_pdc_rx;	/* enable PDC receiver */
+	short			pdc_rx_idx;	/* current PDC RX buffer */
+	struct atmel_dma_buffer	pdc_rx[2];	/* PDC receier */
+
+	bool			use_dma_tx;     /* enable DMA transmitter */
+	bool			use_pdc_tx;	/* enable PDC transmitter */
+	struct atmel_dma_buffer	pdc_tx;		/* PDC transmitter */
+
+	spinlock_t			lock_tx;	/* port lock */
+	spinlock_t			lock_rx;	/* port lock */
+	struct dma_chan			*chan_tx;
+	struct dma_chan			*chan_rx;
+	struct dma_async_tx_descriptor	*desc_tx;
+	struct dma_async_tx_descriptor	*desc_rx;
+	dma_cookie_t			cookie_tx;
+	dma_cookie_t			cookie_rx;
+	struct scatterlist		sg_tx;
+	struct scatterlist		sg_rx;
+	struct tasklet_struct	tasklet_rx;
+	struct tasklet_struct	tasklet_tx;
+	atomic_t		tasklet_shutdown;
+	unsigned int		irq_status_prev;
+	unsigned int		tx_len;
+
+	struct circ_buf		rx_ring;
+
+	struct mctrl_gpios	*gpios;
+	u32			backup_mode;	/* MR saved during iso7816 operations */
+	u32			backup_brgr;	/* BRGR saved during iso7816 operations */
+	unsigned int		tx_done_mask;
+	u32			fifo_size;
+	u32			rts_high;
+	u32			rts_low;
+	bool			ms_irq_enabled;
+	u32			rtor;	/* address of receiver timeout register if it exists */
+	bool			is_usart;
+	bool			has_frac_baudrate;
+	bool			has_hw_timer;
+	struct timer_list	uart_timer;
+
+	bool			tx_stopped;
+	bool			suspended;
+	unsigned int		pending;
+	unsigned int		pending_status;
+	spinlock_t		lock_suspended;
+
+	bool			hd_start_rx;	/* can start RX during half-duplex operation */
+
+	/* ISO7816 */
+	unsigned int		fidi_min;
+	unsigned int		fidi_max;
+
+	struct {
+		u32		cr;
+		u32		mr;
+		u32		imr;
+		u32		brgr;
+		u32		rtor;
+		u32		ttgr;
+		u32		fmr;
+		u32		fimr;
+	} cache;
+
+	int (*prepare_rx)(struct uart_port *port);
+	int (*prepare_tx)(struct uart_port *port);
+	void (*schedule_rx)(struct uart_port *port);
+	void (*schedule_tx)(struct uart_port *port);
+	void (*release_rx)(struct uart_port *port);
+	void (*release_tx)(struct uart_port *port);
+};
+
+static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
+static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART);
+
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_serial_dt_ids[] = {
+	{ .compatible = "atmel,at91rm9200-usart-serial" },
+	{ /* sentinel */ }
+};
+#endif
+
+static inline struct atmel_uart_port *
+to_atmel_uart_port(struct uart_port *uart)
+{
+	return container_of(uart, struct atmel_uart_port, uart);
+}
+
+static inline u32 atmel_uart_readl(struct uart_port *port, u32 reg)
+{
+	return __raw_readl(port->membase + reg);
+}
+
+static inline void atmel_uart_writel(struct uart_port *port, u32 reg, u32 value)
+{
+	__raw_writel(value, port->membase + reg);
+}
+
+static inline u8 atmel_uart_read_char(struct uart_port *port)
+{
+	return __raw_readb(port->membase + ATMEL_US_RHR);
+}
+
+static inline void atmel_uart_write_char(struct uart_port *port, u8 value)
+{
+	__raw_writeb(value, port->membase + ATMEL_US_THR);
+}
+
+static inline int atmel_uart_is_half_duplex(struct uart_port *port)
+{
+	return ((port->rs485.flags & SER_RS485_ENABLED) &&
+		!(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+		(port->iso7816.flags & SER_ISO7816_ENABLED);
+}
+
+static inline int atmel_error_rate(int desired_value, int actual_value)
+{
+	return 100 - (desired_value * 100) / actual_value;
+}
+
+#ifdef CONFIG_SERIAL_ATMEL_PDC
+static bool atmel_use_pdc_rx(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	return atmel_port->use_pdc_rx;
+}
+
+static bool atmel_use_pdc_tx(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	return atmel_port->use_pdc_tx;
+}
+#else
+static bool atmel_use_pdc_rx(struct uart_port *port)
+{
+	return false;
+}
+
+static bool atmel_use_pdc_tx(struct uart_port *port)
+{
+	return false;
+}
+#endif
+
+static bool atmel_use_dma_tx(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	return atmel_port->use_dma_tx;
+}
+
+static bool atmel_use_dma_rx(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	return atmel_port->use_dma_rx;
+}
+
+static bool atmel_use_fifo(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	return atmel_port->fifo_size;
+}
+
+static void atmel_tasklet_schedule(struct atmel_uart_port *atmel_port,
+				   struct tasklet_struct *t)
+{
+	if (!atomic_read(&atmel_port->tasklet_shutdown))
+		tasklet_schedule(t);
+}
+
+/* Enable or disable the rs485 support */
+static int atmel_config_rs485(struct uart_port *port, struct ktermios *termios,
+			      struct serial_rs485 *rs485conf)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int mode;
+
+	/* Disable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
+
+	mode = atmel_uart_readl(port, ATMEL_US_MR);
+
+	if (rs485conf->flags & SER_RS485_ENABLED) {
+		dev_dbg(port->dev, "Setting UART to RS485\n");
+		if (rs485conf->flags & SER_RS485_RX_DURING_TX)
+			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+		else
+			atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
+
+		atmel_uart_writel(port, ATMEL_US_TTGR,
+				  rs485conf->delay_rts_after_send);
+		mode &= ~ATMEL_US_USMODE;
+		mode |= ATMEL_US_USMODE_RS485;
+	} else {
+		dev_dbg(port->dev, "Setting UART to RS232\n");
+		if (atmel_use_pdc_tx(port))
+			atmel_port->tx_done_mask = ATMEL_US_ENDTX |
+				ATMEL_US_TXBUFE;
+		else
+			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+	}
+	atmel_uart_writel(port, ATMEL_US_MR, mode);
+
+	/* Enable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
+
+	return 0;
+}
+
+static unsigned int atmel_calc_cd(struct uart_port *port,
+				  struct serial_iso7816 *iso7816conf)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int cd;
+	u64 mck_rate;
+
+	mck_rate = (u64)clk_get_rate(atmel_port->clk);
+	do_div(mck_rate, iso7816conf->clk);
+	cd = mck_rate;
+	return cd;
+}
+
+static unsigned int atmel_calc_fidi(struct uart_port *port,
+				    struct serial_iso7816 *iso7816conf)
+{
+	u64 fidi = 0;
+
+	if (iso7816conf->sc_fi && iso7816conf->sc_di) {
+		fidi = (u64)iso7816conf->sc_fi;
+		do_div(fidi, iso7816conf->sc_di);
+	}
+	return (u32)fidi;
+}
+
+/* Enable or disable the iso7816 support */
+/* Called with interrupts disabled */
+static int atmel_config_iso7816(struct uart_port *port,
+				struct serial_iso7816 *iso7816conf)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int mode;
+	unsigned int cd, fidi;
+	int ret = 0;
+
+	/* Disable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
+
+	mode = atmel_uart_readl(port, ATMEL_US_MR);
+
+	if (iso7816conf->flags & SER_ISO7816_ENABLED) {
+		mode &= ~ATMEL_US_USMODE;
+
+		if (iso7816conf->tg > 255) {
+			dev_err(port->dev, "ISO7816: Timeguard exceeding 255\n");
+			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+			ret = -EINVAL;
+			goto err_out;
+		}
+
+		if ((iso7816conf->flags & SER_ISO7816_T_PARAM)
+		    == SER_ISO7816_T(0)) {
+			mode |= ATMEL_US_USMODE_ISO7816_T0 | ATMEL_US_DSNACK;
+		} else if ((iso7816conf->flags & SER_ISO7816_T_PARAM)
+			   == SER_ISO7816_T(1)) {
+			mode |= ATMEL_US_USMODE_ISO7816_T1 | ATMEL_US_INACK;
+		} else {
+			dev_err(port->dev, "ISO7816: Type not supported\n");
+			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+			ret = -EINVAL;
+			goto err_out;
+		}
+
+		mode &= ~(ATMEL_US_USCLKS | ATMEL_US_NBSTOP | ATMEL_US_PAR);
+
+		/* select mck clock, and output  */
+		mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO;
+		/* set parity for normal/inverse mode + max iterations */
+		mode |= ATMEL_US_PAR_EVEN | ATMEL_US_NBSTOP_1 | ATMEL_US_MAX_ITER(3);
+
+		cd = atmel_calc_cd(port, iso7816conf);
+		fidi = atmel_calc_fidi(port, iso7816conf);
+		if (fidi == 0) {
+			dev_warn(port->dev, "ISO7816 fidi = 0, Generator generates no signal\n");
+		} else if (fidi < atmel_port->fidi_min
+			   || fidi > atmel_port->fidi_max) {
+			dev_err(port->dev, "ISO7816 fidi = %u, value not supported\n", fidi);
+			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+			ret = -EINVAL;
+			goto err_out;
+		}
+
+		if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) {
+			/* port not yet in iso7816 mode: store configuration */
+			atmel_port->backup_mode = atmel_uart_readl(port, ATMEL_US_MR);
+			atmel_port->backup_brgr = atmel_uart_readl(port, ATMEL_US_BRGR);
+		}
+
+		atmel_uart_writel(port, ATMEL_US_TTGR, iso7816conf->tg);
+		atmel_uart_writel(port, ATMEL_US_BRGR, cd);
+		atmel_uart_writel(port, ATMEL_US_FIDI, fidi);
+
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXEN);
+		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY | ATMEL_US_NACK | ATMEL_US_ITERATION;
+	} else {
+		dev_dbg(port->dev, "Setting UART back to RS232\n");
+		/* back to last RS232 settings */
+		mode = atmel_port->backup_mode;
+		memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+		atmel_uart_writel(port, ATMEL_US_TTGR, 0);
+		atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->backup_brgr);
+		atmel_uart_writel(port, ATMEL_US_FIDI, 0x174);
+
+		if (atmel_use_pdc_tx(port))
+			atmel_port->tx_done_mask = ATMEL_US_ENDTX |
+						   ATMEL_US_TXBUFE;
+		else
+			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+	}
+
+	port->iso7816 = *iso7816conf;
+
+	atmel_uart_writel(port, ATMEL_US_MR, mode);
+
+err_out:
+	/* Enable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
+
+	return ret;
+}
+
+/*
+ * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
+ */
+static u_int atmel_tx_empty(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (atmel_port->tx_stopped)
+		return TIOCSER_TEMT;
+	return (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ?
+		TIOCSER_TEMT :
+		0;
+}
+
+/*
+ * Set state of the modem control output lines
+ */
+static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
+{
+	unsigned int control = 0;
+	unsigned int mode = atmel_uart_readl(port, ATMEL_US_MR);
+	unsigned int rts_paused, rts_ready;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	/* override mode to RS485 if needed, otherwise keep the current mode */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		atmel_uart_writel(port, ATMEL_US_TTGR,
+				  port->rs485.delay_rts_after_send);
+		mode &= ~ATMEL_US_USMODE;
+		mode |= ATMEL_US_USMODE_RS485;
+	}
+
+	/* set the RTS line state according to the mode */
+	if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
+		/* force RTS line to high level */
+		rts_paused = ATMEL_US_RTSEN;
+
+		/* give the control of the RTS line back to the hardware */
+		rts_ready = ATMEL_US_RTSDIS;
+	} else {
+		/* force RTS line to high level */
+		rts_paused = ATMEL_US_RTSDIS;
+
+		/* force RTS line to low level */
+		rts_ready = ATMEL_US_RTSEN;
+	}
+
+	if (mctrl & TIOCM_RTS)
+		control |= rts_ready;
+	else
+		control |= rts_paused;
+
+	if (mctrl & TIOCM_DTR)
+		control |= ATMEL_US_DTREN;
+	else
+		control |= ATMEL_US_DTRDIS;
+
+	atmel_uart_writel(port, ATMEL_US_CR, control);
+
+	mctrl_gpio_set(atmel_port->gpios, mctrl);
+
+	/* Local loopback mode? */
+	mode &= ~ATMEL_US_CHMODE;
+	if (mctrl & TIOCM_LOOP)
+		mode |= ATMEL_US_CHMODE_LOC_LOOP;
+	else
+		mode |= ATMEL_US_CHMODE_NORMAL;
+
+	atmel_uart_writel(port, ATMEL_US_MR, mode);
+}
+
+/*
+ * Get state of the modem control input lines
+ */
+static u_int atmel_get_mctrl(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int ret = 0, status;
+
+	status = atmel_uart_readl(port, ATMEL_US_CSR);
+
+	/*
+	 * The control signals are active low.
+	 */
+	if (!(status & ATMEL_US_DCD))
+		ret |= TIOCM_CD;
+	if (!(status & ATMEL_US_CTS))
+		ret |= TIOCM_CTS;
+	if (!(status & ATMEL_US_DSR))
+		ret |= TIOCM_DSR;
+	if (!(status & ATMEL_US_RI))
+		ret |= TIOCM_RI;
+
+	return mctrl_gpio_get(atmel_port->gpios, &ret);
+}
+
+/*
+ * Stop transmitting.
+ */
+static void atmel_stop_tx(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	bool is_pdc = atmel_use_pdc_tx(port);
+	bool is_dma = is_pdc || atmel_use_dma_tx(port);
+
+	if (is_pdc) {
+		/* disable PDC transmit */
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS);
+	}
+
+	if (is_dma) {
+		/*
+		 * Disable the transmitter.
+		 * This is mandatory when DMA is used, otherwise the DMA buffer
+		 * is fully transmitted.
+		 */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS);
+		atmel_port->tx_stopped = true;
+	}
+
+	/* Disable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
+
+	if (atmel_uart_is_half_duplex(port))
+		if (!atomic_read(&atmel_port->tasklet_shutdown))
+			atmel_start_rx(port);
+}
+
+/*
+ * Start transmitting.
+ */
+static void atmel_start_tx(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	bool is_pdc = atmel_use_pdc_tx(port);
+	bool is_dma = is_pdc || atmel_use_dma_tx(port);
+
+	if (is_pdc && (atmel_uart_readl(port, ATMEL_PDC_PTSR)
+				       & ATMEL_PDC_TXTEN))
+		/* The transmitter is already running.  Yes, we
+		   really need this.*/
+		return;
+
+	if (is_dma && atmel_uart_is_half_duplex(port))
+		atmel_stop_rx(port);
+
+	if (is_pdc) {
+		/* re-enable PDC transmit */
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
+	}
+
+	/* Enable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
+
+	if (is_dma) {
+		/* re-enable the transmitter */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);
+		atmel_port->tx_stopped = false;
+	}
+}
+
+/*
+ * start receiving - port is in process of being opened.
+ */
+static void atmel_start_rx(struct uart_port *port)
+{
+	/* reset status and receiver */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA);
+
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RXEN);
+
+	if (atmel_use_pdc_rx(port)) {
+		/* enable PDC controller */
+		atmel_uart_writel(port, ATMEL_US_IER,
+				  ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
+				  port->read_status_mask);
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN);
+	} else {
+		atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_RXRDY);
+	}
+}
+
+/*
+ * Stop receiving - port is in process of being closed.
+ */
+static void atmel_stop_rx(struct uart_port *port)
+{
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RXDIS);
+
+	if (atmel_use_pdc_rx(port)) {
+		/* disable PDC receive */
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS);
+		atmel_uart_writel(port, ATMEL_US_IDR,
+				  ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
+				  port->read_status_mask);
+	} else {
+		atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_RXRDY);
+	}
+}
+
+/*
+ * Enable modem status interrupts
+ */
+static void atmel_enable_ms(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	uint32_t ier = 0;
+
+	/*
+	 * Interrupt should not be enabled twice
+	 */
+	if (atmel_port->ms_irq_enabled)
+		return;
+
+	atmel_port->ms_irq_enabled = true;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))
+		ier |= ATMEL_US_CTSIC;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DSR))
+		ier |= ATMEL_US_DSRIC;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_RI))
+		ier |= ATMEL_US_RIIC;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DCD))
+		ier |= ATMEL_US_DCDIC;
+
+	atmel_uart_writel(port, ATMEL_US_IER, ier);
+
+	mctrl_gpio_enable_ms(atmel_port->gpios);
+}
+
+/*
+ * Disable modem status interrupts
+ */
+static void atmel_disable_ms(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	uint32_t idr = 0;
+
+	/*
+	 * Interrupt should not be disabled twice
+	 */
+	if (!atmel_port->ms_irq_enabled)
+		return;
+
+	atmel_port->ms_irq_enabled = false;
+
+	mctrl_gpio_disable_ms(atmel_port->gpios);
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))
+		idr |= ATMEL_US_CTSIC;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DSR))
+		idr |= ATMEL_US_DSRIC;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_RI))
+		idr |= ATMEL_US_RIIC;
+
+	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DCD))
+		idr |= ATMEL_US_DCDIC;
+
+	atmel_uart_writel(port, ATMEL_US_IDR, idr);
+}
+
+/*
+ * Control the transmission of a break signal
+ */
+static void atmel_break_ctl(struct uart_port *port, int break_state)
+{
+	if (break_state != 0)
+		/* start break */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTBRK);
+	else
+		/* stop break */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STPBRK);
+}
+
+/*
+ * Stores the incoming character in the ring buffer
+ */
+static void
+atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
+		     unsigned int ch)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct circ_buf *ring = &atmel_port->rx_ring;
+	struct atmel_uart_char *c;
+
+	if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
+		/* Buffer overflow, ignore char */
+		return;
+
+	c = &((struct atmel_uart_char *)ring->buf)[ring->head];
+	c->status	= status;
+	c->ch		= ch;
+
+	/* Make sure the character is stored before we update head. */
+	smp_wmb();
+
+	ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
+}
+
+/*
+ * Deal with parity, framing and overrun errors.
+ */
+static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
+{
+	/* clear error */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA);
+
+	if (status & ATMEL_US_RXBRK) {
+		/* ignore side-effect */
+		status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
+		port->icount.brk++;
+	}
+	if (status & ATMEL_US_PARE)
+		port->icount.parity++;
+	if (status & ATMEL_US_FRAME)
+		port->icount.frame++;
+	if (status & ATMEL_US_OVRE)
+		port->icount.overrun++;
+}
+
+/*
+ * Characters received (called from interrupt handler)
+ */
+static void atmel_rx_chars(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int status, ch;
+
+	status = atmel_uart_readl(port, ATMEL_US_CSR);
+	while (status & ATMEL_US_RXRDY) {
+		ch = atmel_uart_read_char(port);
+
+		/*
+		 * note that the error handling code is
+		 * out of the main execution path
+		 */
+		if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
+				       | ATMEL_US_OVRE | ATMEL_US_RXBRK)
+			     || atmel_port->break_active)) {
+
+			/* clear error */
+			atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA);
+
+			if (status & ATMEL_US_RXBRK
+			    && !atmel_port->break_active) {
+				atmel_port->break_active = 1;
+				atmel_uart_writel(port, ATMEL_US_IER,
+						  ATMEL_US_RXBRK);
+			} else {
+				/*
+				 * This is either the end-of-break
+				 * condition or we've received at
+				 * least one character without RXBRK
+				 * being set. In both cases, the next
+				 * RXBRK will indicate start-of-break.
+				 */
+				atmel_uart_writel(port, ATMEL_US_IDR,
+						  ATMEL_US_RXBRK);
+				status &= ~ATMEL_US_RXBRK;
+				atmel_port->break_active = 0;
+			}
+		}
+
+		atmel_buffer_rx_char(port, status, ch);
+		status = atmel_uart_readl(port, ATMEL_US_CSR);
+	}
+
+	atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx);
+}
+
+/*
+ * Transmit characters (called from tasklet with TXRDY interrupt
+ * disabled)
+ */
+static void atmel_tx_chars(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	bool pending;
+	u8 ch;
+
+	pending = uart_port_tx(port, ch,
+		atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY,
+		atmel_uart_write_char(port, ch));
+	if (pending) {
+		/* we still have characters to transmit, so we should continue
+		 * transmitting them when TX is ready, regardless of
+		 * mode or duplexity
+		 */
+		atmel_port->tx_done_mask |= ATMEL_US_TXRDY;
+
+		/* Enable interrupts */
+		atmel_uart_writel(port, ATMEL_US_IER,
+				  atmel_port->tx_done_mask);
+	} else {
+		if (atmel_uart_is_half_duplex(port))
+			atmel_port->tx_done_mask &= ~ATMEL_US_TXRDY;
+	}
+}
+
+static void atmel_complete_tx_dma(void *arg)
+{
+	struct atmel_uart_port *atmel_port = arg;
+	struct uart_port *port = &atmel_port->uart;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct dma_chan *chan = atmel_port->chan_tx;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (chan)
+		dmaengine_terminate_all(chan);
+	uart_xmit_advance(port, atmel_port->tx_len);
+
+	spin_lock(&atmel_port->lock_tx);
+	async_tx_ack(atmel_port->desc_tx);
+	atmel_port->cookie_tx = -EINVAL;
+	atmel_port->desc_tx = NULL;
+	spin_unlock(&atmel_port->lock_tx);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	/*
+	 * xmit is a circular buffer so, if we have just send data from
+	 * xmit->tail to the end of xmit->buf, now we have to transmit the
+	 * remaining data from the beginning of xmit->buf to xmit->head.
+	 */
+	if (!uart_circ_empty(xmit))
+		atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
+	else if (atmel_uart_is_half_duplex(port)) {
+		/*
+		 * DMA done, re-enable TXEMPTY and signal that we can stop
+		 * TX and start RX for RS485
+		 */
+		atmel_port->hd_start_rx = true;
+		atmel_uart_writel(port, ATMEL_US_IER,
+				  atmel_port->tx_done_mask);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void atmel_release_tx_dma(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct dma_chan *chan = atmel_port->chan_tx;
+
+	if (chan) {
+		dmaengine_terminate_all(chan);
+		dma_release_channel(chan);
+		dma_unmap_sg(port->dev, &atmel_port->sg_tx, 1,
+				DMA_TO_DEVICE);
+	}
+
+	atmel_port->desc_tx = NULL;
+	atmel_port->chan_tx = NULL;
+	atmel_port->cookie_tx = -EINVAL;
+}
+
+/*
+ * Called from tasklet with TXRDY interrupt is disabled.
+ */
+static void atmel_tx_dma(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct circ_buf *xmit = &port->state->xmit;
+	struct dma_chan *chan = atmel_port->chan_tx;
+	struct dma_async_tx_descriptor *desc;
+	struct scatterlist sgl[2], *sg, *sg_tx = &atmel_port->sg_tx;
+	unsigned int tx_len, part1_len, part2_len, sg_len;
+	dma_addr_t phys_addr;
+
+	/* Make sure we have an idle channel */
+	if (atmel_port->desc_tx != NULL)
+		return;
+
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
+		/*
+		 * DMA is idle now.
+		 * Port xmit buffer is already mapped,
+		 * and it is one page... Just adjust
+		 * offsets and lengths. Since it is a circular buffer,
+		 * we have to transmit till the end, and then the rest.
+		 * Take the port lock to get a
+		 * consistent xmit buffer state.
+		 */
+		tx_len = CIRC_CNT_TO_END(xmit->head,
+					 xmit->tail,
+					 UART_XMIT_SIZE);
+
+		if (atmel_port->fifo_size) {
+			/* multi data mode */
+			part1_len = (tx_len & ~0x3); /* DWORD access */
+			part2_len = (tx_len & 0x3); /* BYTE access */
+		} else {
+			/* single data (legacy) mode */
+			part1_len = 0;
+			part2_len = tx_len; /* BYTE access only */
+		}
+
+		sg_init_table(sgl, 2);
+		sg_len = 0;
+		phys_addr = sg_dma_address(sg_tx) + xmit->tail;
+		if (part1_len) {
+			sg = &sgl[sg_len++];
+			sg_dma_address(sg) = phys_addr;
+			sg_dma_len(sg) = part1_len;
+
+			phys_addr += part1_len;
+		}
+
+		if (part2_len) {
+			sg = &sgl[sg_len++];
+			sg_dma_address(sg) = phys_addr;
+			sg_dma_len(sg) = part2_len;
+		}
+
+		/*
+		 * save tx_len so atmel_complete_tx_dma() will increase
+		 * xmit->tail correctly
+		 */
+		atmel_port->tx_len = tx_len;
+
+		desc = dmaengine_prep_slave_sg(chan,
+					       sgl,
+					       sg_len,
+					       DMA_MEM_TO_DEV,
+					       DMA_PREP_INTERRUPT |
+					       DMA_CTRL_ACK);
+		if (!desc) {
+			dev_err(port->dev, "Failed to send via dma!\n");
+			return;
+		}
+
+		dma_sync_sg_for_device(port->dev, sg_tx, 1, DMA_TO_DEVICE);
+
+		atmel_port->desc_tx = desc;
+		desc->callback = atmel_complete_tx_dma;
+		desc->callback_param = atmel_port;
+		atmel_port->cookie_tx = dmaengine_submit(desc);
+		if (dma_submit_error(atmel_port->cookie_tx)) {
+			dev_err(port->dev, "dma_submit_error %d\n",
+				atmel_port->cookie_tx);
+			return;
+		}
+
+		dma_async_issue_pending(chan);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static int atmel_prepare_tx_dma(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct device *mfd_dev = port->dev->parent;
+	dma_cap_mask_t		mask;
+	struct dma_slave_config config;
+	int ret, nent;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	atmel_port->chan_tx = dma_request_slave_channel(mfd_dev, "tx");
+	if (atmel_port->chan_tx == NULL)
+		goto chan_err;
+	dev_info(port->dev, "using %s for tx DMA transfers\n",
+		dma_chan_name(atmel_port->chan_tx));
+
+	spin_lock_init(&atmel_port->lock_tx);
+	sg_init_table(&atmel_port->sg_tx, 1);
+	/* UART circular tx buffer is an aligned page. */
+	BUG_ON(!PAGE_ALIGNED(port->state->xmit.buf));
+	sg_set_page(&atmel_port->sg_tx,
+			virt_to_page(port->state->xmit.buf),
+			UART_XMIT_SIZE,
+			offset_in_page(port->state->xmit.buf));
+	nent = dma_map_sg(port->dev,
+				&atmel_port->sg_tx,
+				1,
+				DMA_TO_DEVICE);
+
+	if (!nent) {
+		dev_dbg(port->dev, "need to release resource of dma\n");
+		goto chan_err;
+	} else {
+		dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", __func__,
+			sg_dma_len(&atmel_port->sg_tx),
+			port->state->xmit.buf,
+			&sg_dma_address(&atmel_port->sg_tx));
+	}
+
+	/* Configure the slave DMA */
+	memset(&config, 0, sizeof(config));
+	config.direction = DMA_MEM_TO_DEV;
+	config.dst_addr_width = (atmel_port->fifo_size) ?
+				DMA_SLAVE_BUSWIDTH_4_BYTES :
+				DMA_SLAVE_BUSWIDTH_1_BYTE;
+	config.dst_addr = port->mapbase + ATMEL_US_THR;
+	config.dst_maxburst = 1;
+
+	ret = dmaengine_slave_config(atmel_port->chan_tx,
+				     &config);
+	if (ret) {
+		dev_err(port->dev, "DMA tx slave configuration failed\n");
+		goto chan_err;
+	}
+
+	return 0;
+
+chan_err:
+	dev_err(port->dev, "TX channel not available, switch to pio\n");
+	atmel_port->use_dma_tx = false;
+	if (atmel_port->chan_tx)
+		atmel_release_tx_dma(port);
+	return -EINVAL;
+}
+
+static void atmel_complete_rx_dma(void *arg)
+{
+	struct uart_port *port = arg;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx);
+}
+
+static void atmel_release_rx_dma(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct dma_chan *chan = atmel_port->chan_rx;
+
+	if (chan) {
+		dmaengine_terminate_all(chan);
+		dma_release_channel(chan);
+		dma_unmap_sg(port->dev, &atmel_port->sg_rx, 1,
+				DMA_FROM_DEVICE);
+	}
+
+	atmel_port->desc_rx = NULL;
+	atmel_port->chan_rx = NULL;
+	atmel_port->cookie_rx = -EINVAL;
+}
+
+static void atmel_rx_from_dma(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct tty_port *tport = &port->state->port;
+	struct circ_buf *ring = &atmel_port->rx_ring;
+	struct dma_chan *chan = atmel_port->chan_rx;
+	struct dma_tx_state state;
+	enum dma_status dmastat;
+	size_t count;
+
+
+	/* Reset the UART timeout early so that we don't miss one */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO);
+	dmastat = dmaengine_tx_status(chan,
+				atmel_port->cookie_rx,
+				&state);
+	/* Restart a new tasklet if DMA status is error */
+	if (dmastat == DMA_ERROR) {
+		dev_dbg(port->dev, "Get residue error, restart tasklet\n");
+		atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT);
+		atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx);
+		return;
+	}
+
+	/* CPU claims ownership of RX DMA buffer */
+	dma_sync_sg_for_cpu(port->dev,
+			    &atmel_port->sg_rx,
+			    1,
+			    DMA_FROM_DEVICE);
+
+	/*
+	 * ring->head points to the end of data already written by the DMA.
+	 * ring->tail points to the beginning of data to be read by the
+	 * framework.
+	 * The current transfer size should not be larger than the dma buffer
+	 * length.
+	 */
+	ring->head = sg_dma_len(&atmel_port->sg_rx) - state.residue;
+	BUG_ON(ring->head > sg_dma_len(&atmel_port->sg_rx));
+	/*
+	 * At this point ring->head may point to the first byte right after the
+	 * last byte of the dma buffer:
+	 * 0 <= ring->head <= sg_dma_len(&atmel_port->sg_rx)
+	 *
+	 * However ring->tail must always points inside the dma buffer:
+	 * 0 <= ring->tail <= sg_dma_len(&atmel_port->sg_rx) - 1
+	 *
+	 * Since we use a ring buffer, we have to handle the case
+	 * where head is lower than tail. In such a case, we first read from
+	 * tail to the end of the buffer then reset tail.
+	 */
+	if (ring->head < ring->tail) {
+		count = sg_dma_len(&atmel_port->sg_rx) - ring->tail;
+
+		tty_insert_flip_string(tport, ring->buf + ring->tail, count);
+		ring->tail = 0;
+		port->icount.rx += count;
+	}
+
+	/* Finally we read data from tail to head */
+	if (ring->tail < ring->head) {
+		count = ring->head - ring->tail;
+
+		tty_insert_flip_string(tport, ring->buf + ring->tail, count);
+		/* Wrap ring->head if needed */
+		if (ring->head >= sg_dma_len(&atmel_port->sg_rx))
+			ring->head = 0;
+		ring->tail = ring->head;
+		port->icount.rx += count;
+	}
+
+	/* USART retreives ownership of RX DMA buffer */
+	dma_sync_sg_for_device(port->dev,
+			       &atmel_port->sg_rx,
+			       1,
+			       DMA_FROM_DEVICE);
+
+	tty_flip_buffer_push(tport);
+
+	atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT);
+}
+
+static int atmel_prepare_rx_dma(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct device *mfd_dev = port->dev->parent;
+	struct dma_async_tx_descriptor *desc;
+	dma_cap_mask_t		mask;
+	struct dma_slave_config config;
+	struct circ_buf		*ring;
+	int ret, nent;
+
+	ring = &atmel_port->rx_ring;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_CYCLIC, mask);
+
+	atmel_port->chan_rx = dma_request_slave_channel(mfd_dev, "rx");
+	if (atmel_port->chan_rx == NULL)
+		goto chan_err;
+	dev_info(port->dev, "using %s for rx DMA transfers\n",
+		dma_chan_name(atmel_port->chan_rx));
+
+	spin_lock_init(&atmel_port->lock_rx);
+	sg_init_table(&atmel_port->sg_rx, 1);
+	/* UART circular rx buffer is an aligned page. */
+	BUG_ON(!PAGE_ALIGNED(ring->buf));
+	sg_set_page(&atmel_port->sg_rx,
+		    virt_to_page(ring->buf),
+		    sizeof(struct atmel_uart_char) * ATMEL_SERIAL_RINGSIZE,
+		    offset_in_page(ring->buf));
+	nent = dma_map_sg(port->dev,
+			  &atmel_port->sg_rx,
+			  1,
+			  DMA_FROM_DEVICE);
+
+	if (!nent) {
+		dev_dbg(port->dev, "need to release resource of dma\n");
+		goto chan_err;
+	} else {
+		dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", __func__,
+			sg_dma_len(&atmel_port->sg_rx),
+			ring->buf,
+			&sg_dma_address(&atmel_port->sg_rx));
+	}
+
+	/* Configure the slave DMA */
+	memset(&config, 0, sizeof(config));
+	config.direction = DMA_DEV_TO_MEM;
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	config.src_addr = port->mapbase + ATMEL_US_RHR;
+	config.src_maxburst = 1;
+
+	ret = dmaengine_slave_config(atmel_port->chan_rx,
+				     &config);
+	if (ret) {
+		dev_err(port->dev, "DMA rx slave configuration failed\n");
+		goto chan_err;
+	}
+	/*
+	 * Prepare a cyclic dma transfer, assign 2 descriptors,
+	 * each one is half ring buffer size
+	 */
+	desc = dmaengine_prep_dma_cyclic(atmel_port->chan_rx,
+					 sg_dma_address(&atmel_port->sg_rx),
+					 sg_dma_len(&atmel_port->sg_rx),
+					 sg_dma_len(&atmel_port->sg_rx)/2,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(port->dev, "Preparing DMA cyclic failed\n");
+		goto chan_err;
+	}
+	desc->callback = atmel_complete_rx_dma;
+	desc->callback_param = port;
+	atmel_port->desc_rx = desc;
+	atmel_port->cookie_rx = dmaengine_submit(desc);
+	if (dma_submit_error(atmel_port->cookie_rx)) {
+		dev_err(port->dev, "dma_submit_error %d\n",
+			atmel_port->cookie_rx);
+		goto chan_err;
+	}
+
+	dma_async_issue_pending(atmel_port->chan_rx);
+
+	return 0;
+
+chan_err:
+	dev_err(port->dev, "RX channel not available, switch to pio\n");
+	atmel_port->use_dma_rx = false;
+	if (atmel_port->chan_rx)
+		atmel_release_rx_dma(port);
+	return -EINVAL;
+}
+
+static void atmel_uart_timer_callback(struct timer_list *t)
+{
+	struct atmel_uart_port *atmel_port = from_timer(atmel_port, t,
+							uart_timer);
+	struct uart_port *port = &atmel_port->uart;
+
+	if (!atomic_read(&atmel_port->tasklet_shutdown)) {
+		tasklet_schedule(&atmel_port->tasklet_rx);
+		mod_timer(&atmel_port->uart_timer,
+			  jiffies + uart_poll_timeout(port));
+	}
+}
+
+/*
+ * receive interrupt handler.
+ */
+static void
+atmel_handle_receive(struct uart_port *port, unsigned int pending)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (atmel_use_pdc_rx(port)) {
+		/*
+		 * PDC receive. Just schedule the tasklet and let it
+		 * figure out the details.
+		 *
+		 * TODO: We're not handling error flags correctly at
+		 * the moment.
+		 */
+		if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
+			atmel_uart_writel(port, ATMEL_US_IDR,
+					  (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT));
+			atmel_tasklet_schedule(atmel_port,
+					       &atmel_port->tasklet_rx);
+		}
+
+		if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
+				ATMEL_US_FRAME | ATMEL_US_PARE))
+			atmel_pdc_rxerr(port, pending);
+	}
+
+	if (atmel_use_dma_rx(port)) {
+		if (pending & ATMEL_US_TIMEOUT) {
+			atmel_uart_writel(port, ATMEL_US_IDR,
+					  ATMEL_US_TIMEOUT);
+			atmel_tasklet_schedule(atmel_port,
+					       &atmel_port->tasklet_rx);
+		}
+	}
+
+	/* Interrupt receive */
+	if (pending & ATMEL_US_RXRDY)
+		atmel_rx_chars(port);
+	else if (pending & ATMEL_US_RXBRK) {
+		/*
+		 * End of break detected. If it came along with a
+		 * character, atmel_rx_chars will handle it.
+		 */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA);
+		atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_RXBRK);
+		atmel_port->break_active = 0;
+	}
+}
+
+/*
+ * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
+ */
+static void
+atmel_handle_transmit(struct uart_port *port, unsigned int pending)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (pending & atmel_port->tx_done_mask) {
+		atmel_uart_writel(port, ATMEL_US_IDR,
+				  atmel_port->tx_done_mask);
+
+		/* Start RX if flag was set and FIFO is empty */
+		if (atmel_port->hd_start_rx) {
+			if (!(atmel_uart_readl(port, ATMEL_US_CSR)
+					& ATMEL_US_TXEMPTY))
+				dev_warn(port->dev, "Should start RX, but TX fifo is not empty\n");
+
+			atmel_port->hd_start_rx = false;
+			atmel_start_rx(port);
+		}
+
+		atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
+	}
+}
+
+/*
+ * status flags interrupt handler.
+ */
+static void
+atmel_handle_status(struct uart_port *port, unsigned int pending,
+		    unsigned int status)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int status_change;
+
+	if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
+				| ATMEL_US_CTSIC)) {
+		status_change = status ^ atmel_port->irq_status_prev;
+		atmel_port->irq_status_prev = status;
+
+		if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
+					| ATMEL_US_DCD | ATMEL_US_CTS)) {
+			/* TODO: All reads to CSR will clear these interrupts! */
+			if (status_change & ATMEL_US_RI)
+				port->icount.rng++;
+			if (status_change & ATMEL_US_DSR)
+				port->icount.dsr++;
+			if (status_change & ATMEL_US_DCD)
+				uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
+			if (status_change & ATMEL_US_CTS)
+				uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
+
+			wake_up_interruptible(&port->state->port.delta_msr_wait);
+		}
+	}
+
+	if (pending & (ATMEL_US_NACK | ATMEL_US_ITERATION))
+		dev_dbg(port->dev, "ISO7816 ERROR (0x%08x)\n", pending);
+}
+
+/*
+ * Interrupt handler
+ */
+static irqreturn_t atmel_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int status, pending, mask, pass_counter = 0;
+
+	spin_lock(&atmel_port->lock_suspended);
+
+	do {
+		status = atmel_uart_readl(port, ATMEL_US_CSR);
+		mask = atmel_uart_readl(port, ATMEL_US_IMR);
+		pending = status & mask;
+		if (!pending)
+			break;
+
+		if (atmel_port->suspended) {
+			atmel_port->pending |= pending;
+			atmel_port->pending_status = status;
+			atmel_uart_writel(port, ATMEL_US_IDR, mask);
+			pm_system_wakeup();
+			break;
+		}
+
+		atmel_handle_receive(port, pending);
+		atmel_handle_status(port, pending, status);
+		atmel_handle_transmit(port, pending);
+	} while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
+
+	spin_unlock(&atmel_port->lock_suspended);
+
+	return pass_counter ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static void atmel_release_tx_pdc(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+
+	dma_unmap_single(port->dev,
+			 pdc->dma_addr,
+			 pdc->dma_size,
+			 DMA_TO_DEVICE);
+}
+
+/*
+ * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
+ */
+static void atmel_tx_pdc(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct circ_buf *xmit = &port->state->xmit;
+	struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+	int count;
+
+	/* nothing left to transmit? */
+	if (atmel_uart_readl(port, ATMEL_PDC_TCR))
+		return;
+	uart_xmit_advance(port, pdc->ofs);
+	pdc->ofs = 0;
+
+	/* more to transmit - setup next transfer */
+
+	/* disable PDC transmit */
+	atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS);
+
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
+		dma_sync_single_for_device(port->dev,
+					   pdc->dma_addr,
+					   pdc->dma_size,
+					   DMA_TO_DEVICE);
+
+		count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+		pdc->ofs = count;
+
+		atmel_uart_writel(port, ATMEL_PDC_TPR,
+				  pdc->dma_addr + xmit->tail);
+		atmel_uart_writel(port, ATMEL_PDC_TCR, count);
+		/* re-enable PDC transmit */
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
+		/* Enable interrupts */
+		atmel_uart_writel(port, ATMEL_US_IER,
+				  atmel_port->tx_done_mask);
+	} else {
+		if (atmel_uart_is_half_duplex(port)) {
+			/* DMA done, stop TX, start RX for RS485 */
+			atmel_start_rx(port);
+		}
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static int atmel_prepare_tx_pdc(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+	struct circ_buf *xmit = &port->state->xmit;
+
+	pdc->buf = xmit->buf;
+	pdc->dma_addr = dma_map_single(port->dev,
+					pdc->buf,
+					UART_XMIT_SIZE,
+					DMA_TO_DEVICE);
+	pdc->dma_size = UART_XMIT_SIZE;
+	pdc->ofs = 0;
+
+	return 0;
+}
+
+static void atmel_rx_from_ring(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct circ_buf *ring = &atmel_port->rx_ring;
+	unsigned int status;
+	u8 flg;
+
+	while (ring->head != ring->tail) {
+		struct atmel_uart_char c;
+
+		/* Make sure c is loaded after head. */
+		smp_rmb();
+
+		c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
+
+		ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
+
+		port->icount.rx++;
+		status = c.status;
+		flg = TTY_NORMAL;
+
+		/*
+		 * note that the error handling code is
+		 * out of the main execution path
+		 */
+		if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
+				       | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
+			if (status & ATMEL_US_RXBRK) {
+				/* ignore side-effect */
+				status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
+
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			}
+			if (status & ATMEL_US_PARE)
+				port->icount.parity++;
+			if (status & ATMEL_US_FRAME)
+				port->icount.frame++;
+			if (status & ATMEL_US_OVRE)
+				port->icount.overrun++;
+
+			status &= port->read_status_mask;
+
+			if (status & ATMEL_US_RXBRK)
+				flg = TTY_BREAK;
+			else if (status & ATMEL_US_PARE)
+				flg = TTY_PARITY;
+			else if (status & ATMEL_US_FRAME)
+				flg = TTY_FRAME;
+		}
+
+
+		if (uart_handle_sysrq_char(port, c.ch))
+			continue;
+
+		uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void atmel_release_rx_pdc(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
+
+		dma_unmap_single(port->dev,
+				 pdc->dma_addr,
+				 pdc->dma_size,
+				 DMA_FROM_DEVICE);
+		kfree(pdc->buf);
+	}
+}
+
+static void atmel_rx_from_pdc(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	struct tty_port *tport = &port->state->port;
+	struct atmel_dma_buffer *pdc;
+	int rx_idx = atmel_port->pdc_rx_idx;
+	unsigned int head;
+	unsigned int tail;
+	unsigned int count;
+
+	do {
+		/* Reset the UART timeout early so that we don't miss one */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO);
+
+		pdc = &atmel_port->pdc_rx[rx_idx];
+		head = atmel_uart_readl(port, ATMEL_PDC_RPR) - pdc->dma_addr;
+		tail = pdc->ofs;
+
+		/* If the PDC has switched buffers, RPR won't contain
+		 * any address within the current buffer. Since head
+		 * is unsigned, we just need a one-way comparison to
+		 * find out.
+		 *
+		 * In this case, we just need to consume the entire
+		 * buffer and resubmit it for DMA. This will clear the
+		 * ENDRX bit as well, so that we can safely re-enable
+		 * all interrupts below.
+		 */
+		head = min(head, pdc->dma_size);
+
+		if (likely(head != tail)) {
+			dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
+					pdc->dma_size, DMA_FROM_DEVICE);
+
+			/*
+			 * head will only wrap around when we recycle
+			 * the DMA buffer, and when that happens, we
+			 * explicitly set tail to 0. So head will
+			 * always be greater than tail.
+			 */
+			count = head - tail;
+
+			tty_insert_flip_string(tport, pdc->buf + pdc->ofs,
+						count);
+
+			dma_sync_single_for_device(port->dev, pdc->dma_addr,
+					pdc->dma_size, DMA_FROM_DEVICE);
+
+			port->icount.rx += count;
+			pdc->ofs = head;
+		}
+
+		/*
+		 * If the current buffer is full, we need to check if
+		 * the next one contains any additional data.
+		 */
+		if (head >= pdc->dma_size) {
+			pdc->ofs = 0;
+			atmel_uart_writel(port, ATMEL_PDC_RNPR, pdc->dma_addr);
+			atmel_uart_writel(port, ATMEL_PDC_RNCR, pdc->dma_size);
+
+			rx_idx = !rx_idx;
+			atmel_port->pdc_rx_idx = rx_idx;
+		}
+	} while (head >= pdc->dma_size);
+
+	tty_flip_buffer_push(tport);
+
+	atmel_uart_writel(port, ATMEL_US_IER,
+			  ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
+}
+
+static int atmel_prepare_rx_pdc(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
+
+		pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
+		if (pdc->buf == NULL) {
+			if (i != 0) {
+				dma_unmap_single(port->dev,
+					atmel_port->pdc_rx[0].dma_addr,
+					PDC_BUFFER_SIZE,
+					DMA_FROM_DEVICE);
+				kfree(atmel_port->pdc_rx[0].buf);
+			}
+			atmel_port->use_pdc_rx = false;
+			return -ENOMEM;
+		}
+		pdc->dma_addr = dma_map_single(port->dev,
+						pdc->buf,
+						PDC_BUFFER_SIZE,
+						DMA_FROM_DEVICE);
+		pdc->dma_size = PDC_BUFFER_SIZE;
+		pdc->ofs = 0;
+	}
+
+	atmel_port->pdc_rx_idx = 0;
+
+	atmel_uart_writel(port, ATMEL_PDC_RPR, atmel_port->pdc_rx[0].dma_addr);
+	atmel_uart_writel(port, ATMEL_PDC_RCR, PDC_BUFFER_SIZE);
+
+	atmel_uart_writel(port, ATMEL_PDC_RNPR,
+			  atmel_port->pdc_rx[1].dma_addr);
+	atmel_uart_writel(port, ATMEL_PDC_RNCR, PDC_BUFFER_SIZE);
+
+	return 0;
+}
+
+/*
+ * tasklet handling tty stuff outside the interrupt handler.
+ */
+static void atmel_tasklet_rx_func(struct tasklet_struct *t)
+{
+	struct atmel_uart_port *atmel_port = from_tasklet(atmel_port, t,
+							  tasklet_rx);
+	struct uart_port *port = &atmel_port->uart;
+
+	/* The interrupt handler does not take the lock */
+	spin_lock(&port->lock);
+	atmel_port->schedule_rx(port);
+	spin_unlock(&port->lock);
+}
+
+static void atmel_tasklet_tx_func(struct tasklet_struct *t)
+{
+	struct atmel_uart_port *atmel_port = from_tasklet(atmel_port, t,
+							  tasklet_tx);
+	struct uart_port *port = &atmel_port->uart;
+
+	/* The interrupt handler does not take the lock */
+	spin_lock(&port->lock);
+	atmel_port->schedule_tx(port);
+	spin_unlock(&port->lock);
+}
+
+static void atmel_init_property(struct atmel_uart_port *atmel_port,
+				struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+
+	/* DMA/PDC usage specification */
+	if (of_property_read_bool(np, "atmel,use-dma-rx")) {
+		if (of_property_read_bool(np, "dmas")) {
+			atmel_port->use_dma_rx  = true;
+			atmel_port->use_pdc_rx  = false;
+		} else {
+			atmel_port->use_dma_rx  = false;
+			atmel_port->use_pdc_rx  = true;
+		}
+	} else {
+		atmel_port->use_dma_rx  = false;
+		atmel_port->use_pdc_rx  = false;
+	}
+
+	if (of_property_read_bool(np, "atmel,use-dma-tx")) {
+		if (of_property_read_bool(np, "dmas")) {
+			atmel_port->use_dma_tx  = true;
+			atmel_port->use_pdc_tx  = false;
+		} else {
+			atmel_port->use_dma_tx  = false;
+			atmel_port->use_pdc_tx  = true;
+		}
+	} else {
+		atmel_port->use_dma_tx  = false;
+		atmel_port->use_pdc_tx  = false;
+	}
+}
+
+static void atmel_set_ops(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (atmel_use_dma_rx(port)) {
+		atmel_port->prepare_rx = &atmel_prepare_rx_dma;
+		atmel_port->schedule_rx = &atmel_rx_from_dma;
+		atmel_port->release_rx = &atmel_release_rx_dma;
+	} else if (atmel_use_pdc_rx(port)) {
+		atmel_port->prepare_rx = &atmel_prepare_rx_pdc;
+		atmel_port->schedule_rx = &atmel_rx_from_pdc;
+		atmel_port->release_rx = &atmel_release_rx_pdc;
+	} else {
+		atmel_port->prepare_rx = NULL;
+		atmel_port->schedule_rx = &atmel_rx_from_ring;
+		atmel_port->release_rx = NULL;
+	}
+
+	if (atmel_use_dma_tx(port)) {
+		atmel_port->prepare_tx = &atmel_prepare_tx_dma;
+		atmel_port->schedule_tx = &atmel_tx_dma;
+		atmel_port->release_tx = &atmel_release_tx_dma;
+	} else if (atmel_use_pdc_tx(port)) {
+		atmel_port->prepare_tx = &atmel_prepare_tx_pdc;
+		atmel_port->schedule_tx = &atmel_tx_pdc;
+		atmel_port->release_tx = &atmel_release_tx_pdc;
+	} else {
+		atmel_port->prepare_tx = NULL;
+		atmel_port->schedule_tx = &atmel_tx_chars;
+		atmel_port->release_tx = NULL;
+	}
+}
+
+/*
+ * Get ip name usart or uart
+ */
+static void atmel_get_ip_name(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	int name = atmel_uart_readl(port, ATMEL_US_NAME);
+	u32 version;
+	u32 usart, dbgu_uart, new_uart;
+	/* ASCII decoding for IP version */
+	usart = 0x55534152;	/* USAR(T) */
+	dbgu_uart = 0x44424755;	/* DBGU */
+	new_uart = 0x55415254;	/* UART */
+
+	/*
+	 * Only USART devices from at91sam9260 SOC implement fractional
+	 * baudrate. It is available for all asynchronous modes, with the
+	 * following restriction: the sampling clock's duty cycle is not
+	 * constant.
+	 */
+	atmel_port->has_frac_baudrate = false;
+	atmel_port->has_hw_timer = false;
+	atmel_port->is_usart = false;
+
+	if (name == new_uart) {
+		dev_dbg(port->dev, "Uart with hw timer");
+		atmel_port->has_hw_timer = true;
+		atmel_port->rtor = ATMEL_UA_RTOR;
+	} else if (name == usart) {
+		dev_dbg(port->dev, "Usart\n");
+		atmel_port->has_frac_baudrate = true;
+		atmel_port->has_hw_timer = true;
+		atmel_port->is_usart = true;
+		atmel_port->rtor = ATMEL_US_RTOR;
+		version = atmel_uart_readl(port, ATMEL_US_VERSION);
+		switch (version) {
+		case 0x814:	/* sama5d2 */
+			fallthrough;
+		case 0x701:	/* sama5d4 */
+			atmel_port->fidi_min = 3;
+			atmel_port->fidi_max = 65535;
+			break;
+		case 0x502:	/* sam9x5, sama5d3 */
+			atmel_port->fidi_min = 3;
+			atmel_port->fidi_max = 2047;
+			break;
+		default:
+			atmel_port->fidi_min = 1;
+			atmel_port->fidi_max = 2047;
+		}
+	} else if (name == dbgu_uart) {
+		dev_dbg(port->dev, "Dbgu or uart without hw timer\n");
+	} else {
+		/* fallback for older SoCs: use version field */
+		version = atmel_uart_readl(port, ATMEL_US_VERSION);
+		switch (version) {
+		case 0x302:
+		case 0x10213:
+		case 0x10302:
+			dev_dbg(port->dev, "This version is usart\n");
+			atmel_port->has_frac_baudrate = true;
+			atmel_port->has_hw_timer = true;
+			atmel_port->is_usart = true;
+			atmel_port->rtor = ATMEL_US_RTOR;
+			break;
+		case 0x203:
+		case 0x10202:
+			dev_dbg(port->dev, "This version is uart\n");
+			break;
+		default:
+			dev_err(port->dev, "Not supported ip name nor version, set to uart\n");
+		}
+	}
+}
+
+/*
+ * Perform initialization and enable port for reception
+ */
+static int atmel_startup(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	int retval;
+
+	/*
+	 * Ensure that no interrupts are enabled otherwise when
+	 * request_irq() is called we could get stuck trying to
+	 * handle an unexpected interrupt
+	 */
+	atmel_uart_writel(port, ATMEL_US_IDR, -1);
+	atmel_port->ms_irq_enabled = false;
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(port->irq, atmel_interrupt,
+			     IRQF_SHARED | IRQF_COND_SUSPEND,
+			     dev_name(&pdev->dev), port);
+	if (retval) {
+		dev_err(port->dev, "atmel_startup - Can't get irq\n");
+		return retval;
+	}
+
+	atomic_set(&atmel_port->tasklet_shutdown, 0);
+	tasklet_setup(&atmel_port->tasklet_rx, atmel_tasklet_rx_func);
+	tasklet_setup(&atmel_port->tasklet_tx, atmel_tasklet_tx_func);
+
+	/*
+	 * Initialize DMA (if necessary)
+	 */
+	atmel_init_property(atmel_port, pdev);
+	atmel_set_ops(port);
+
+	if (atmel_port->prepare_rx) {
+		retval = atmel_port->prepare_rx(port);
+		if (retval < 0)
+			atmel_set_ops(port);
+	}
+
+	if (atmel_port->prepare_tx) {
+		retval = atmel_port->prepare_tx(port);
+		if (retval < 0)
+			atmel_set_ops(port);
+	}
+
+	/*
+	 * Enable FIFO when available
+	 */
+	if (atmel_port->fifo_size) {
+		unsigned int txrdym = ATMEL_US_ONE_DATA;
+		unsigned int rxrdym = ATMEL_US_ONE_DATA;
+		unsigned int fmr;
+
+		atmel_uart_writel(port, ATMEL_US_CR,
+				  ATMEL_US_FIFOEN |
+				  ATMEL_US_RXFCLR |
+				  ATMEL_US_TXFLCLR);
+
+		if (atmel_use_dma_tx(port))
+			txrdym = ATMEL_US_FOUR_DATA;
+
+		fmr = ATMEL_US_TXRDYM(txrdym) | ATMEL_US_RXRDYM(rxrdym);
+		if (atmel_port->rts_high &&
+		    atmel_port->rts_low)
+			fmr |=	ATMEL_US_FRTSC |
+				ATMEL_US_RXFTHRES(atmel_port->rts_high) |
+				ATMEL_US_RXFTHRES2(atmel_port->rts_low);
+
+		atmel_uart_writel(port, ATMEL_US_FMR, fmr);
+	}
+
+	/* Save current CSR for comparison in atmel_tasklet_func() */
+	atmel_port->irq_status_prev = atmel_uart_readl(port, ATMEL_US_CSR);
+
+	/*
+	 * Finally, enable the serial port
+	 */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
+	/* enable xmit & rcvr */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
+	atmel_port->tx_stopped = false;
+
+	timer_setup(&atmel_port->uart_timer, atmel_uart_timer_callback, 0);
+
+	if (atmel_use_pdc_rx(port)) {
+		/* set UART timeout */
+		if (!atmel_port->has_hw_timer) {
+			mod_timer(&atmel_port->uart_timer,
+					jiffies + uart_poll_timeout(port));
+		/* set USART timeout */
+		} else {
+			atmel_uart_writel(port, atmel_port->rtor,
+					  PDC_RX_TIMEOUT);
+			atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO);
+
+			atmel_uart_writel(port, ATMEL_US_IER,
+					  ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
+		}
+		/* enable PDC controller */
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN);
+	} else if (atmel_use_dma_rx(port)) {
+		/* set UART timeout */
+		if (!atmel_port->has_hw_timer) {
+			mod_timer(&atmel_port->uart_timer,
+					jiffies + uart_poll_timeout(port));
+		/* set USART timeout */
+		} else {
+			atmel_uart_writel(port, atmel_port->rtor,
+					  PDC_RX_TIMEOUT);
+			atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO);
+
+			atmel_uart_writel(port, ATMEL_US_IER,
+					  ATMEL_US_TIMEOUT);
+		}
+	} else {
+		/* enable receive only */
+		atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_RXRDY);
+	}
+
+	return 0;
+}
+
+/*
+ * Flush any TX data submitted for DMA. Called when the TX circular
+ * buffer is reset.
+ */
+static void atmel_flush_buffer(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (atmel_use_pdc_tx(port)) {
+		atmel_uart_writel(port, ATMEL_PDC_TCR, 0);
+		atmel_port->pdc_tx.ofs = 0;
+	}
+	/*
+	 * in uart_flush_buffer(), the xmit circular buffer has just
+	 * been cleared, so we have to reset tx_len accordingly.
+	 */
+	atmel_port->tx_len = 0;
+}
+
+/*
+ * Disable the port
+ */
+static void atmel_shutdown(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	/* Disable modem control lines interrupts */
+	atmel_disable_ms(port);
+
+	/* Disable interrupts at device level */
+	atmel_uart_writel(port, ATMEL_US_IDR, -1);
+
+	/* Prevent spurious interrupts from scheduling the tasklet */
+	atomic_inc(&atmel_port->tasklet_shutdown);
+
+	/*
+	 * Prevent any tasklets being scheduled during
+	 * cleanup
+	 */
+	del_timer_sync(&atmel_port->uart_timer);
+
+	/* Make sure that no interrupt is on the fly */
+	synchronize_irq(port->irq);
+
+	/*
+	 * Clear out any scheduled tasklets before
+	 * we destroy the buffers
+	 */
+	tasklet_kill(&atmel_port->tasklet_rx);
+	tasklet_kill(&atmel_port->tasklet_tx);
+
+	/*
+	 * Ensure everything is stopped and
+	 * disable port and break condition.
+	 */
+	atmel_stop_rx(port);
+	atmel_stop_tx(port);
+
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA);
+
+	/*
+	 * Shut-down the DMA.
+	 */
+	if (atmel_port->release_rx)
+		atmel_port->release_rx(port);
+	if (atmel_port->release_tx)
+		atmel_port->release_tx(port);
+
+	/*
+	 * Reset ring buffer pointers
+	 */
+	atmel_port->rx_ring.head = 0;
+	atmel_port->rx_ring.tail = 0;
+
+	/*
+	 * Free the interrupts
+	 */
+	free_irq(port->irq, port);
+
+	atmel_flush_buffer(port);
+}
+
+/*
+ * Power / Clock management.
+ */
+static void atmel_serial_pm(struct uart_port *port, unsigned int state,
+			    unsigned int oldstate)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	switch (state) {
+	case UART_PM_STATE_ON:
+		/*
+		 * Enable the peripheral clock for this serial port.
+		 * This is called on uart_open() or a resume event.
+		 */
+		clk_prepare_enable(atmel_port->clk);
+
+		/* re-enable interrupts if we disabled some on suspend */
+		atmel_uart_writel(port, ATMEL_US_IER, atmel_port->backup_imr);
+		break;
+	case UART_PM_STATE_OFF:
+		/* Back up the interrupt mask and disable all interrupts */
+		atmel_port->backup_imr = atmel_uart_readl(port, ATMEL_US_IMR);
+		atmel_uart_writel(port, ATMEL_US_IDR, -1);
+
+		/*
+		 * Disable the peripheral clock for this serial port.
+		 * This is called on uart_close() or a suspend event.
+		 */
+		clk_disable_unprepare(atmel_port->clk);
+		if (__clk_is_enabled(atmel_port->gclk))
+			clk_disable_unprepare(atmel_port->gclk);
+		break;
+	default:
+		dev_err(port->dev, "atmel_serial: unknown pm %d\n", state);
+	}
+}
+
+/*
+ * Change the port parameters
+ */
+static void atmel_set_termios(struct uart_port *port,
+			      struct ktermios *termios,
+			      const struct ktermios *old)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned long flags;
+	unsigned int old_mode, mode, imr, quot, div, cd, fp = 0;
+	unsigned int baud, actual_baud, gclk_rate;
+	int ret;
+
+	/* save the current mode register */
+	mode = old_mode = atmel_uart_readl(port, ATMEL_US_MR);
+
+	/* reset the mode, clock divisor, parity, stop bits and data size */
+	if (atmel_port->is_usart)
+		mode &= ~(ATMEL_US_NBSTOP | ATMEL_US_PAR | ATMEL_US_CHRL |
+			  ATMEL_US_USCLKS | ATMEL_US_USMODE);
+	else
+		mode &= ~(ATMEL_UA_BRSRCCK | ATMEL_US_PAR | ATMEL_UA_FILTER);
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+
+	/* byte size */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		mode |= ATMEL_US_CHRL_5;
+		break;
+	case CS6:
+		mode |= ATMEL_US_CHRL_6;
+		break;
+	case CS7:
+		mode |= ATMEL_US_CHRL_7;
+		break;
+	default:
+		mode |= ATMEL_US_CHRL_8;
+		break;
+	}
+
+	/* stop bits */
+	if (termios->c_cflag & CSTOPB)
+		mode |= ATMEL_US_NBSTOP_2;
+
+	/* parity */
+	if (termios->c_cflag & PARENB) {
+		/* Mark or Space parity */
+		if (termios->c_cflag & CMSPAR) {
+			if (termios->c_cflag & PARODD)
+				mode |= ATMEL_US_PAR_MARK;
+			else
+				mode |= ATMEL_US_PAR_SPACE;
+		} else if (termios->c_cflag & PARODD)
+			mode |= ATMEL_US_PAR_ODD;
+		else
+			mode |= ATMEL_US_PAR_EVEN;
+	} else
+		mode |= ATMEL_US_PAR_NONE;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	port->read_status_mask = ATMEL_US_OVRE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= ATMEL_US_RXBRK;
+
+	if (atmel_use_pdc_rx(port))
+		/* need to enable error interrupts */
+		atmel_uart_writel(port, ATMEL_US_IER, port->read_status_mask);
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= ATMEL_US_RXBRK;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= ATMEL_US_OVRE;
+	}
+	/* TODO: Ignore all characters if CREAD is set.*/
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * save/disable interrupts. The tty layer will ensure that the
+	 * transmitter is empty if requested by the caller, so there's
+	 * no need to wait for it here.
+	 */
+	imr = atmel_uart_readl(port, ATMEL_US_IMR);
+	atmel_uart_writel(port, ATMEL_US_IDR, -1);
+
+	/* disable receiver and transmitter */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
+	atmel_port->tx_stopped = true;
+
+	/* mode */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		atmel_uart_writel(port, ATMEL_US_TTGR,
+				  port->rs485.delay_rts_after_send);
+		mode |= ATMEL_US_USMODE_RS485;
+	} else if (port->iso7816.flags & SER_ISO7816_ENABLED) {
+		atmel_uart_writel(port, ATMEL_US_TTGR, port->iso7816.tg);
+		/* select mck clock, and output  */
+		mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO;
+		/* set max iterations */
+		mode |= ATMEL_US_MAX_ITER(3);
+		if ((port->iso7816.flags & SER_ISO7816_T_PARAM)
+				== SER_ISO7816_T(0))
+			mode |= ATMEL_US_USMODE_ISO7816_T0;
+		else
+			mode |= ATMEL_US_USMODE_ISO7816_T1;
+	} else if (termios->c_cflag & CRTSCTS) {
+		/* RS232 with hardware handshake (RTS/CTS) */
+		if (atmel_use_fifo(port) &&
+		    !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) {
+			/*
+			 * with ATMEL_US_USMODE_HWHS set, the controller will
+			 * be able to drive the RTS pin high/low when the RX
+			 * FIFO is above RXFTHRES/below RXFTHRES2.
+			 * It will also disable the transmitter when the CTS
+			 * pin is high.
+			 * This mode is not activated if CTS pin is a GPIO
+			 * because in this case, the transmitter is always
+			 * disabled (there must be an internal pull-up
+			 * responsible for this behaviour).
+			 * If the RTS pin is a GPIO, the controller won't be
+			 * able to drive it according to the FIFO thresholds,
+			 * but it will be handled by the driver.
+			 */
+			mode |= ATMEL_US_USMODE_HWHS;
+		} else {
+			/*
+			 * For platforms without FIFO, the flow control is
+			 * handled by the driver.
+			 */
+			mode |= ATMEL_US_USMODE_NORMAL;
+		}
+	} else {
+		/* RS232 without hadware handshake */
+		mode |= ATMEL_US_USMODE_NORMAL;
+	}
+
+	/*
+	 * Set the baud rate:
+	 * Fractional baudrate allows to setup output frequency more
+	 * accurately. This feature is enabled only when using normal mode.
+	 * baudrate = selected clock / (8 * (2 - OVER) * (CD + FP / 8))
+	 * Currently, OVER is always set to 0 so we get
+	 * baudrate = selected clock / (16 * (CD + FP / 8))
+	 * then
+	 * 8 CD + FP = selected clock / (2 * baudrate)
+	 */
+	if (atmel_port->has_frac_baudrate) {
+		div = DIV_ROUND_CLOSEST(port->uartclk, baud * 2);
+		cd = div >> 3;
+		fp = div & ATMEL_US_FP_MASK;
+	} else {
+		cd = uart_get_divisor(port, baud);
+	}
+
+	/*
+	 * If the current value of the Clock Divisor surpasses the 16 bit
+	 * ATMEL_US_CD mask and the IP is USART, switch to the Peripheral
+	 * Clock implicitly divided by 8.
+	 * If the IP is UART however, keep the highest possible value for
+	 * the CD and avoid needless division of CD, since UART IP's do not
+	 * support implicit division of the Peripheral Clock.
+	 */
+	if (atmel_port->is_usart && cd > ATMEL_US_CD) {
+		cd /= 8;
+		mode |= ATMEL_US_USCLKS_MCK_DIV8;
+	} else {
+		cd = min_t(unsigned int, cd, ATMEL_US_CD);
+	}
+
+	/*
+	 * If there is no Fractional Part, there is a high chance that
+	 * we may be able to generate a baudrate closer to the desired one
+	 * if we use the GCLK as the clock source driving the baudrate
+	 * generator.
+	 */
+	if (!atmel_port->has_frac_baudrate) {
+		if (__clk_is_enabled(atmel_port->gclk))
+			clk_disable_unprepare(atmel_port->gclk);
+		gclk_rate = clk_round_rate(atmel_port->gclk, 16 * baud);
+		actual_baud = clk_get_rate(atmel_port->clk) / (16 * cd);
+		if (gclk_rate && abs(atmel_error_rate(baud, actual_baud)) >
+		    abs(atmel_error_rate(baud, gclk_rate / 16))) {
+			clk_set_rate(atmel_port->gclk, 16 * baud);
+			ret = clk_prepare_enable(atmel_port->gclk);
+			if (ret)
+				goto gclk_fail;
+
+			if (atmel_port->is_usart) {
+				mode &= ~ATMEL_US_USCLKS;
+				mode |= ATMEL_US_USCLKS_GCLK;
+			} else {
+				mode |= ATMEL_UA_BRSRCCK;
+			}
+
+			/*
+			 * Set the Clock Divisor for GCLK to 1.
+			 * Since we were able to generate the smallest
+			 * multiple of the desired baudrate times 16,
+			 * then we surely can generate a bigger multiple
+			 * with the exact error rate for an equally increased
+			 * CD. Thus no need to take into account
+			 * a higher value for CD.
+			 */
+			cd = 1;
+		}
+	}
+
+gclk_fail:
+	quot = cd | fp << ATMEL_US_FP_OFFSET;
+
+	if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
+		atmel_uart_writel(port, ATMEL_US_BRGR, quot);
+
+	/* set the mode, clock divisor, parity, stop bits and data size */
+	atmel_uart_writel(port, ATMEL_US_MR, mode);
+
+	/*
+	 * when switching the mode, set the RTS line state according to the
+	 * new mode, otherwise keep the former state
+	 */
+	if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
+		unsigned int rts_state;
+
+		if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
+			/* let the hardware control the RTS line */
+			rts_state = ATMEL_US_RTSDIS;
+		} else {
+			/* force RTS line to low level */
+			rts_state = ATMEL_US_RTSEN;
+		}
+
+		atmel_uart_writel(port, ATMEL_US_CR, rts_state);
+	}
+
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
+	atmel_port->tx_stopped = false;
+
+	/* restore interrupts */
+	atmel_uart_writel(port, ATMEL_US_IER, imr);
+
+	/* CTS flow-control and modem-status interrupts */
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		atmel_enable_ms(port);
+	else
+		atmel_disable_ms(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void atmel_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	if (termios->c_line == N_PPS) {
+		port->flags |= UPF_HARDPPS_CD;
+		spin_lock_irq(&port->lock);
+		atmel_enable_ms(port);
+		spin_unlock_irq(&port->lock);
+	} else {
+		port->flags &= ~UPF_HARDPPS_CD;
+		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
+			spin_lock_irq(&port->lock);
+			atmel_disable_ms(port);
+			spin_unlock_irq(&port->lock);
+		}
+	}
+}
+
+/*
+ * Return string describing the specified port
+ */
+static const char *atmel_type(struct uart_port *port)
+{
+	return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
+}
+
+/*
+ * Release the memory region(s) being used by 'port'.
+ */
+static void atmel_release_port(struct uart_port *port)
+{
+	struct platform_device *mpdev = to_platform_device(port->dev->parent);
+	int size = resource_size(mpdev->resource);
+
+	release_mem_region(port->mapbase, size);
+
+	if (port->flags & UPF_IOREMAP) {
+		iounmap(port->membase);
+		port->membase = NULL;
+	}
+}
+
+/*
+ * Request the memory region(s) being used by 'port'.
+ */
+static int atmel_request_port(struct uart_port *port)
+{
+	struct platform_device *mpdev = to_platform_device(port->dev->parent);
+	int size = resource_size(mpdev->resource);
+
+	if (!request_mem_region(port->mapbase, size, "atmel_serial"))
+		return -EBUSY;
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = ioremap(port->mapbase, size);
+		if (port->membase == NULL) {
+			release_mem_region(port->mapbase, size);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void atmel_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_ATMEL;
+		atmel_request_port(port);
+	}
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
+		ret = -EINVAL;
+	if (port->irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->io_type != SERIAL_IO_MEM)
+		ret = -EINVAL;
+	if (port->uartclk / 16 != ser->baud_base)
+		ret = -EINVAL;
+	if (port->mapbase != (unsigned long)ser->iomem_base)
+		ret = -EINVAL;
+	if (port->iobase != ser->port)
+		ret = -EINVAL;
+	if (ser->hub6 != 0)
+		ret = -EINVAL;
+	return ret;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int atmel_poll_get_char(struct uart_port *port)
+{
+	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_RXRDY))
+		cpu_relax();
+
+	return atmel_uart_read_char(port);
+}
+
+static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))
+		cpu_relax();
+
+	atmel_uart_write_char(port, ch);
+}
+#endif
+
+static const struct uart_ops atmel_pops = {
+	.tx_empty	= atmel_tx_empty,
+	.set_mctrl	= atmel_set_mctrl,
+	.get_mctrl	= atmel_get_mctrl,
+	.stop_tx	= atmel_stop_tx,
+	.start_tx	= atmel_start_tx,
+	.stop_rx	= atmel_stop_rx,
+	.enable_ms	= atmel_enable_ms,
+	.break_ctl	= atmel_break_ctl,
+	.startup	= atmel_startup,
+	.shutdown	= atmel_shutdown,
+	.flush_buffer	= atmel_flush_buffer,
+	.set_termios	= atmel_set_termios,
+	.set_ldisc	= atmel_set_ldisc,
+	.type		= atmel_type,
+	.release_port	= atmel_release_port,
+	.request_port	= atmel_request_port,
+	.config_port	= atmel_config_port,
+	.verify_port	= atmel_verify_port,
+	.pm		= atmel_serial_pm,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= atmel_poll_get_char,
+	.poll_put_char	= atmel_poll_put_char,
+#endif
+};
+
+static const struct serial_rs485 atmel_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+/*
+ * Configure the port from the platform device resource info.
+ */
+static int atmel_init_port(struct atmel_uart_port *atmel_port,
+				      struct platform_device *pdev)
+{
+	int ret;
+	struct uart_port *port = &atmel_port->uart;
+	struct platform_device *mpdev = to_platform_device(pdev->dev.parent);
+
+	atmel_init_property(atmel_port, pdev);
+	atmel_set_ops(port);
+
+	port->iotype		= UPIO_MEM;
+	port->flags		= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+	port->ops		= &atmel_pops;
+	port->fifosize		= 1;
+	port->dev		= &pdev->dev;
+	port->mapbase		= mpdev->resource[0].start;
+	port->irq		= platform_get_irq(mpdev, 0);
+	port->rs485_config	= atmel_config_rs485;
+	port->rs485_supported	= atmel_rs485_supported;
+	port->iso7816_config	= atmel_config_iso7816;
+	port->membase		= NULL;
+
+	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
+
+	ret = uart_get_rs485_mode(port);
+	if (ret)
+		return ret;
+
+	port->uartclk = clk_get_rate(atmel_port->clk);
+
+	/*
+	 * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
+	 * ENDTX|TXBUFE
+	 */
+	if (atmel_uart_is_half_duplex(port))
+		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
+	else if (atmel_use_pdc_tx(port)) {
+		port->fifosize = PDC_BUFFER_SIZE;
+		atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
+	} else {
+		atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
+static void atmel_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))
+		cpu_relax();
+	atmel_uart_write_char(port, ch);
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void atmel_console_write(struct console *co, const char *s, u_int count)
+{
+	struct uart_port *port = &atmel_ports[co->index].uart;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int status, imr;
+	unsigned int pdc_tx;
+
+	/*
+	 * First, save IMR and then disable interrupts
+	 */
+	imr = atmel_uart_readl(port, ATMEL_US_IMR);
+	atmel_uart_writel(port, ATMEL_US_IDR,
+			  ATMEL_US_RXRDY | atmel_port->tx_done_mask);
+
+	/* Store PDC transmit status and disable it */
+	pdc_tx = atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN;
+	atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS);
+
+	/* Make sure that tx path is actually able to send characters */
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);
+	atmel_port->tx_stopped = false;
+
+	uart_console_write(port, s, count, atmel_console_putchar);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore IMR
+	 */
+	do {
+		status = atmel_uart_readl(port, ATMEL_US_CSR);
+	} while (!(status & ATMEL_US_TXRDY));
+
+	/* Restore PDC transmit status */
+	if (pdc_tx)
+		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
+
+	/* set interrupts back the way they were */
+	atmel_uart_writel(port, ATMEL_US_IER, imr);
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init atmel_console_get_options(struct uart_port *port, int *baud,
+					     int *parity, int *bits)
+{
+	unsigned int mr, quot;
+
+	/*
+	 * If the baud rate generator isn't running, the port wasn't
+	 * initialized by the boot loader.
+	 */
+	quot = atmel_uart_readl(port, ATMEL_US_BRGR) & ATMEL_US_CD;
+	if (!quot)
+		return;
+
+	mr = atmel_uart_readl(port, ATMEL_US_MR) & ATMEL_US_CHRL;
+	if (mr == ATMEL_US_CHRL_8)
+		*bits = 8;
+	else
+		*bits = 7;
+
+	mr = atmel_uart_readl(port, ATMEL_US_MR) & ATMEL_US_PAR;
+	if (mr == ATMEL_US_PAR_EVEN)
+		*parity = 'e';
+	else if (mr == ATMEL_US_PAR_ODD)
+		*parity = 'o';
+
+	*baud = port->uartclk / (16 * quot);
+}
+
+static int __init atmel_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port = &atmel_ports[co->index].uart;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (port->membase == NULL) {
+		/* Port not initialized yet - delay setup */
+		return -ENODEV;
+	}
+
+	atmel_uart_writel(port, ATMEL_US_IDR, -1);
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
+	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
+	atmel_port->tx_stopped = false;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		atmel_console_get_options(port, &baud, &parity, &bits);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver atmel_uart;
+
+static struct console atmel_console = {
+	.name		= ATMEL_DEVICENAME,
+	.write		= atmel_console_write,
+	.device		= uart_console_device,
+	.setup		= atmel_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &atmel_uart,
+};
+
+static void atmel_serial_early_write(struct console *con, const char *s,
+				     unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, atmel_console_putchar);
+}
+
+static int __init atmel_early_console_setup(struct earlycon_device *device,
+					    const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = atmel_serial_early_write;
+
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(atmel_serial, "atmel,at91rm9200-usart",
+		    atmel_early_console_setup);
+OF_EARLYCON_DECLARE(atmel_serial, "atmel,at91sam9260-usart",
+		    atmel_early_console_setup);
+
+#define ATMEL_CONSOLE_DEVICE	(&atmel_console)
+
+#else
+#define ATMEL_CONSOLE_DEVICE	NULL
+#endif
+
+static struct uart_driver atmel_uart = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "atmel_serial",
+	.dev_name	= ATMEL_DEVICENAME,
+	.major		= SERIAL_ATMEL_MAJOR,
+	.minor		= MINOR_START,
+	.nr		= ATMEL_MAX_UART,
+	.cons		= ATMEL_CONSOLE_DEVICE,
+};
+
+static bool atmel_serial_clk_will_stop(void)
+{
+#ifdef CONFIG_ARCH_AT91
+	return at91_suspend_entering_slow_clock();
+#else
+	return false;
+#endif
+}
+
+static int __maybe_unused atmel_serial_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	if (uart_console(port) && console_suspend_enabled) {
+		/* Drain the TX shifter */
+		while (!(atmel_uart_readl(port, ATMEL_US_CSR) &
+			 ATMEL_US_TXEMPTY))
+			cpu_relax();
+	}
+
+	if (uart_console(port) && !console_suspend_enabled) {
+		/* Cache register values as we won't get a full shutdown/startup
+		 * cycle
+		 */
+		atmel_port->cache.mr = atmel_uart_readl(port, ATMEL_US_MR);
+		atmel_port->cache.imr = atmel_uart_readl(port, ATMEL_US_IMR);
+		atmel_port->cache.brgr = atmel_uart_readl(port, ATMEL_US_BRGR);
+		atmel_port->cache.rtor = atmel_uart_readl(port,
+							  atmel_port->rtor);
+		atmel_port->cache.ttgr = atmel_uart_readl(port, ATMEL_US_TTGR);
+		atmel_port->cache.fmr = atmel_uart_readl(port, ATMEL_US_FMR);
+		atmel_port->cache.fimr = atmel_uart_readl(port, ATMEL_US_FIMR);
+	}
+
+	/* we can not wake up if we're running on slow clock */
+	atmel_port->may_wakeup = device_may_wakeup(dev);
+	if (atmel_serial_clk_will_stop()) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&atmel_port->lock_suspended, flags);
+		atmel_port->suspended = true;
+		spin_unlock_irqrestore(&atmel_port->lock_suspended, flags);
+		device_set_wakeup_enable(dev, 0);
+	}
+
+	uart_suspend_port(&atmel_uart, port);
+
+	return 0;
+}
+
+static int __maybe_unused atmel_serial_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned long flags;
+
+	if (uart_console(port) && !console_suspend_enabled) {
+		atmel_uart_writel(port, ATMEL_US_MR, atmel_port->cache.mr);
+		atmel_uart_writel(port, ATMEL_US_IER, atmel_port->cache.imr);
+		atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->cache.brgr);
+		atmel_uart_writel(port, atmel_port->rtor,
+				  atmel_port->cache.rtor);
+		atmel_uart_writel(port, ATMEL_US_TTGR, atmel_port->cache.ttgr);
+
+		if (atmel_port->fifo_size) {
+			atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_FIFOEN |
+					  ATMEL_US_RXFCLR | ATMEL_US_TXFLCLR);
+			atmel_uart_writel(port, ATMEL_US_FMR,
+					  atmel_port->cache.fmr);
+			atmel_uart_writel(port, ATMEL_US_FIER,
+					  atmel_port->cache.fimr);
+		}
+		atmel_start_rx(port);
+	}
+
+	spin_lock_irqsave(&atmel_port->lock_suspended, flags);
+	if (atmel_port->pending) {
+		atmel_handle_receive(port, atmel_port->pending);
+		atmel_handle_status(port, atmel_port->pending,
+				    atmel_port->pending_status);
+		atmel_handle_transmit(port, atmel_port->pending);
+		atmel_port->pending = 0;
+	}
+	atmel_port->suspended = false;
+	spin_unlock_irqrestore(&atmel_port->lock_suspended, flags);
+
+	uart_resume_port(&atmel_uart, port);
+	device_set_wakeup_enable(dev, atmel_port->may_wakeup);
+
+	return 0;
+}
+
+static void atmel_serial_probe_fifos(struct atmel_uart_port *atmel_port,
+				     struct platform_device *pdev)
+{
+	atmel_port->fifo_size = 0;
+	atmel_port->rts_low = 0;
+	atmel_port->rts_high = 0;
+
+	if (of_property_read_u32(pdev->dev.of_node,
+				 "atmel,fifo-size",
+				 &atmel_port->fifo_size))
+		return;
+
+	if (!atmel_port->fifo_size)
+		return;
+
+	if (atmel_port->fifo_size < ATMEL_MIN_FIFO_SIZE) {
+		atmel_port->fifo_size = 0;
+		dev_err(&pdev->dev, "Invalid FIFO size\n");
+		return;
+	}
+
+	/*
+	 * 0 <= rts_low <= rts_high <= fifo_size
+	 * Once their CTS line asserted by the remote peer, some x86 UARTs tend
+	 * to flush their internal TX FIFO, commonly up to 16 data, before
+	 * actually stopping to send new data. So we try to set the RTS High
+	 * Threshold to a reasonably high value respecting this 16 data
+	 * empirical rule when possible.
+	 */
+	atmel_port->rts_high = max_t(int, atmel_port->fifo_size >> 1,
+			       atmel_port->fifo_size - ATMEL_RTS_HIGH_OFFSET);
+	atmel_port->rts_low  = max_t(int, atmel_port->fifo_size >> 2,
+			       atmel_port->fifo_size - ATMEL_RTS_LOW_OFFSET);
+
+	dev_info(&pdev->dev, "Using FIFO (%u data)\n",
+		 atmel_port->fifo_size);
+	dev_dbg(&pdev->dev, "RTS High Threshold : %2u data\n",
+		atmel_port->rts_high);
+	dev_dbg(&pdev->dev, "RTS Low Threshold  : %2u data\n",
+		atmel_port->rts_low);
+}
+
+static int atmel_serial_probe(struct platform_device *pdev)
+{
+	struct atmel_uart_port *atmel_port;
+	struct device_node *np = pdev->dev.parent->of_node;
+	void *data;
+	int ret;
+	bool rs485_enabled;
+
+	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
+
+	/*
+	 * In device tree there is no node with "atmel,at91rm9200-usart-serial"
+	 * as compatible string. This driver is probed by at91-usart mfd driver
+	 * which is just a wrapper over the atmel_serial driver and
+	 * spi-at91-usart driver. All attributes needed by this driver are
+	 * found in of_node of parent.
+	 */
+	pdev->dev.of_node = np;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0)
+		/* port id not found in platform data nor device-tree aliases:
+		 * auto-enumerate it */
+		ret = find_first_zero_bit(atmel_ports_in_use, ATMEL_MAX_UART);
+
+	if (ret >= ATMEL_MAX_UART) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	if (test_and_set_bit(ret, atmel_ports_in_use)) {
+		/* port already in use */
+		ret = -EBUSY;
+		goto err;
+	}
+
+	atmel_port = &atmel_ports[ret];
+	atmel_port->backup_imr = 0;
+	atmel_port->uart.line = ret;
+	atmel_port->uart.has_sysrq = IS_ENABLED(CONFIG_SERIAL_ATMEL_CONSOLE);
+	atmel_serial_probe_fifos(atmel_port, pdev);
+
+	atomic_set(&atmel_port->tasklet_shutdown, 0);
+	spin_lock_init(&atmel_port->lock_suspended);
+
+	atmel_port->clk = devm_clk_get(&pdev->dev, "usart");
+	if (IS_ERR(atmel_port->clk)) {
+		ret = PTR_ERR(atmel_port->clk);
+		goto err;
+	}
+	ret = clk_prepare_enable(atmel_port->clk);
+	if (ret)
+		goto err;
+
+	atmel_port->gclk = devm_clk_get_optional(&pdev->dev, "gclk");
+	if (IS_ERR(atmel_port->gclk)) {
+		ret = PTR_ERR(atmel_port->gclk);
+		goto err_clk_disable_unprepare;
+	}
+
+	ret = atmel_init_port(atmel_port, pdev);
+	if (ret)
+		goto err_clk_disable_unprepare;
+
+	atmel_port->gpios = mctrl_gpio_init(&atmel_port->uart, 0);
+	if (IS_ERR(atmel_port->gpios)) {
+		ret = PTR_ERR(atmel_port->gpios);
+		goto err_clk_disable_unprepare;
+	}
+
+	if (!atmel_use_pdc_rx(&atmel_port->uart)) {
+		ret = -ENOMEM;
+		data = kmalloc_array(ATMEL_SERIAL_RINGSIZE,
+				     sizeof(struct atmel_uart_char),
+				     GFP_KERNEL);
+		if (!data)
+			goto err_clk_disable_unprepare;
+		atmel_port->rx_ring.buf = data;
+	}
+
+	rs485_enabled = atmel_port->uart.rs485.flags & SER_RS485_ENABLED;
+
+	ret = uart_add_one_port(&atmel_uart, &atmel_port->uart);
+	if (ret)
+		goto err_add_port;
+
+	device_init_wakeup(&pdev->dev, 1);
+	platform_set_drvdata(pdev, atmel_port);
+
+	if (rs485_enabled) {
+		atmel_uart_writel(&atmel_port->uart, ATMEL_US_MR,
+				  ATMEL_US_USMODE_NORMAL);
+		atmel_uart_writel(&atmel_port->uart, ATMEL_US_CR,
+				  ATMEL_US_RTSEN);
+	}
+
+	/*
+	 * Get port name of usart or uart
+	 */
+	atmel_get_ip_name(&atmel_port->uart);
+
+	/*
+	 * The peripheral clock can now safely be disabled till the port
+	 * is used
+	 */
+	clk_disable_unprepare(atmel_port->clk);
+
+	return 0;
+
+err_add_port:
+	kfree(atmel_port->rx_ring.buf);
+	atmel_port->rx_ring.buf = NULL;
+err_clk_disable_unprepare:
+	clk_disable_unprepare(atmel_port->clk);
+	clear_bit(atmel_port->uart.line, atmel_ports_in_use);
+err:
+	return ret;
+}
+
+/*
+ * Even if the driver is not modular, it makes sense to be able to
+ * unbind a device: there can be many bound devices, and there are
+ * situations where dynamic binding and unbinding can be useful.
+ *
+ * For example, a connected device can require a specific firmware update
+ * protocol that needs bitbanging on IO lines, but use the regular serial
+ * port in the normal case.
+ */
+static int atmel_serial_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	tasklet_kill(&atmel_port->tasklet_rx);
+	tasklet_kill(&atmel_port->tasklet_tx);
+
+	device_init_wakeup(&pdev->dev, 0);
+
+	uart_remove_one_port(&atmel_uart, port);
+
+	kfree(atmel_port->rx_ring.buf);
+
+	/* "port" is allocated statically, so we shouldn't free it */
+
+	clear_bit(port->line, atmel_ports_in_use);
+
+	pdev->dev.of_node = NULL;
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(atmel_serial_pm_ops, atmel_serial_suspend,
+			 atmel_serial_resume);
+
+static struct platform_driver atmel_serial_driver = {
+	.probe		= atmel_serial_probe,
+	.remove		= atmel_serial_remove,
+	.driver		= {
+		.name			= "atmel_usart_serial",
+		.of_match_table		= of_match_ptr(atmel_serial_dt_ids),
+		.pm			= pm_ptr(&atmel_serial_pm_ops),
+	},
+};
+
+static int __init atmel_serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&atmel_uart);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&atmel_serial_driver);
+	if (ret)
+		uart_unregister_driver(&atmel_uart);
+
+	return ret;
+}
+device_initcall(atmel_serial_init);
diff --git a/drivers/tty/serial/atmel_serial.h b/drivers/tty/serial/atmel_serial.h
new file mode 100644
index 000000000..87f8f7996
--- /dev/null
+++ b/drivers/tty/serial/atmel_serial.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * include/linux/atmel_serial.h
+ *
+ * Copyright (C) 2005 Ivan Kokshaysky
+ * Copyright (C) SAN People
+ *
+ * USART registers.
+ * Based on AT91RM9200 datasheet revision E.
+ */
+
+#include <linux/bitfield.h>
+
+#ifndef ATMEL_SERIAL_H
+#define ATMEL_SERIAL_H
+
+#define ATMEL_US_CR		0x00	/* Control Register */
+#define	ATMEL_US_RSTRX		BIT(2)	/* Reset Receiver */
+#define	ATMEL_US_RSTTX		BIT(3)	/* Reset Transmitter */
+#define	ATMEL_US_RXEN		BIT(4)	/* Receiver Enable */
+#define	ATMEL_US_RXDIS		BIT(5)	/* Receiver Disable */
+#define	ATMEL_US_TXEN		BIT(6)	/* Transmitter Enable */
+#define	ATMEL_US_TXDIS		BIT(7)	/* Transmitter Disable */
+#define	ATMEL_US_RSTSTA		BIT(8)	/* Reset Status Bits */
+#define	ATMEL_US_STTBRK		BIT(9)	/* Start Break */
+#define	ATMEL_US_STPBRK		BIT(10)	/* Stop Break */
+#define	ATMEL_US_STTTO		BIT(11)	/* Start Time-out */
+#define	ATMEL_US_SENDA		BIT(12)	/* Send Address */
+#define	ATMEL_US_RSTIT		BIT(13)	/* Reset Iterations */
+#define	ATMEL_US_RSTNACK	BIT(14)	/* Reset Non Acknowledge */
+#define	ATMEL_US_RETTO		BIT(15)	/* Rearm Time-out */
+#define	ATMEL_US_DTREN		BIT(16)	/* Data Terminal Ready Enable */
+#define	ATMEL_US_DTRDIS		BIT(17)	/* Data Terminal Ready Disable */
+#define	ATMEL_US_RTSEN		BIT(18)	/* Request To Send Enable */
+#define	ATMEL_US_RTSDIS		BIT(19)	/* Request To Send Disable */
+#define	ATMEL_US_TXFCLR		BIT(24)	/* Transmit FIFO Clear */
+#define	ATMEL_US_RXFCLR		BIT(25)	/* Receive FIFO Clear */
+#define	ATMEL_US_TXFLCLR	BIT(26)	/* Transmit FIFO Lock Clear */
+#define	ATMEL_US_FIFOEN		BIT(30)	/* FIFO enable */
+#define	ATMEL_US_FIFODIS	BIT(31)	/* FIFO disable */
+
+#define ATMEL_US_MR		0x04	/* Mode Register */
+#define	ATMEL_US_USMODE		GENMASK(3, 0)	/* Mode of the USART */
+#define		ATMEL_US_USMODE_NORMAL		FIELD_PREP(ATMEL_US_USMODE, 0)
+#define		ATMEL_US_USMODE_RS485		FIELD_PREP(ATMEL_US_USMODE, 1)
+#define		ATMEL_US_USMODE_HWHS		FIELD_PREP(ATMEL_US_USMODE, 2)
+#define		ATMEL_US_USMODE_MODEM		FIELD_PREP(ATMEL_US_USMODE, 3)
+#define		ATMEL_US_USMODE_ISO7816_T0	FIELD_PREP(ATMEL_US_USMODE, 4)
+#define		ATMEL_US_USMODE_ISO7816_T1	FIELD_PREP(ATMEL_US_USMODE, 6)
+#define		ATMEL_US_USMODE_IRDA		FIELD_PREP(ATMEL_US_USMODE, 8)
+#define	ATMEL_US_USCLKS		GENMASK(5, 4)	/* Clock Selection */
+#define		ATMEL_US_USCLKS_MCK		FIELD_PREP(ATMEL_US_USCLKS, 0)
+#define		ATMEL_US_USCLKS_MCK_DIV8	FIELD_PREP(ATMEL_US_USCLKS, 1)
+#define		ATMEL_US_USCLKS_GCLK		FIELD_PREP(ATMEL_US_USCLKS, 2)
+#define		ATMEL_US_USCLKS_SCK		FIELD_PREP(ATMEL_US_USCLKS, 3)
+#define	ATMEL_UA_FILTER		BIT(4)
+#define	ATMEL_US_CHRL		GENMASK(7, 6)	/* Character Length */
+#define		ATMEL_US_CHRL_5			FIELD_PREP(ATMEL_US_CHRL, 0)
+#define		ATMEL_US_CHRL_6			FIELD_PREP(ATMEL_US_CHRL, 1)
+#define		ATMEL_US_CHRL_7			FIELD_PREP(ATMEL_US_CHRL, 2)
+#define		ATMEL_US_CHRL_8			FIELD_PREP(ATMEL_US_CHRL, 3)
+#define	ATMEL_US_SYNC		BIT(8)		/* Synchronous Mode Select */
+#define	ATMEL_US_PAR		GENMASK(11, 9)	/* Parity Type */
+#define		ATMEL_US_PAR_EVEN		FIELD_PREP(ATMEL_US_PAR, 0)
+#define		ATMEL_US_PAR_ODD		FIELD_PREP(ATMEL_US_PAR, 1)
+#define		ATMEL_US_PAR_SPACE		FIELD_PREP(ATMEL_US_PAR, 2)
+#define		ATMEL_US_PAR_MARK		FIELD_PREP(ATMEL_US_PAR, 3)
+#define		ATMEL_US_PAR_NONE		FIELD_PREP(ATMEL_US_PAR, 4)
+#define		ATMEL_US_PAR_MULTI_DROP		FIELD_PREP(ATMEL_US_PAR, 6)
+#define	ATMEL_US_NBSTOP		GENMASK(13, 12)	/* Number of Stop Bits */
+#define		ATMEL_US_NBSTOP_1		FIELD_PREP(ATMEL_US_NBSTOP, 0)
+#define		ATMEL_US_NBSTOP_1_5		FIELD_PREP(ATMEL_US_NBSTOP, 1)
+#define		ATMEL_US_NBSTOP_2		FIELD_PREP(ATMEL_US_NBSTOP, 2)
+#define	ATMEL_UA_BRSRCCK	BIT(12)	/* Clock Selection for UART */
+#define	ATMEL_US_CHMODE		GENMASK(15, 14)	/* Channel Mode */
+#define		ATMEL_US_CHMODE_NORMAL		FIELD_PREP(ATMEL_US_CHMODE, 0)
+#define		ATMEL_US_CHMODE_ECHO		FIELD_PREP(ATMEL_US_CHMODE, 1)
+#define		ATMEL_US_CHMODE_LOC_LOOP	FIELD_PREP(ATMEL_US_CHMODE, 2)
+#define		ATMEL_US_CHMODE_REM_LOOP	FIELD_PREP(ATMEL_US_CHMODE, 3)
+#define	ATMEL_US_MSBF		BIT(16)	/* Bit Order */
+#define	ATMEL_US_MODE9		BIT(17)	/* 9-bit Character Length */
+#define	ATMEL_US_CLKO		BIT(18)	/* Clock Output Select */
+#define	ATMEL_US_OVER		BIT(19)	/* Oversampling Mode */
+#define	ATMEL_US_INACK		BIT(20)	/* Inhibit Non Acknowledge */
+#define	ATMEL_US_DSNACK		BIT(21)	/* Disable Successive NACK */
+#define	ATMEL_US_MAX_ITER_MASK	GENMASK(26, 24)	/* Max Iterations */
+#define	ATMEL_US_MAX_ITER(n)	FIELD_PREP(ATMEL_US_MAX_ITER_MASK, (n))
+#define	ATMEL_US_FILTER		BIT(28)	/* Infrared Receive Line Filter */
+
+#define ATMEL_US_IER		0x08	/* Interrupt Enable Register */
+#define	ATMEL_US_RXRDY		BIT(0)	/* Receiver Ready */
+#define	ATMEL_US_TXRDY		BIT(1)	/* Transmitter Ready */
+#define	ATMEL_US_RXBRK		BIT(2)	/* Break Received / End of Break */
+#define	ATMEL_US_ENDRX		BIT(3)	/* End of Receiver Transfer */
+#define	ATMEL_US_ENDTX		BIT(4)	/* End of Transmitter Transfer */
+#define	ATMEL_US_OVRE		BIT(5)	/* Overrun Error */
+#define	ATMEL_US_FRAME		BIT(6)	/* Framing Error */
+#define	ATMEL_US_PARE		BIT(7)	/* Parity Error */
+#define	ATMEL_US_TIMEOUT	BIT(8)	/* Receiver Time-out */
+#define	ATMEL_US_TXEMPTY	BIT(9)	/* Transmitter Empty */
+#define	ATMEL_US_ITERATION	BIT(10)	/* Max number of Repetitions Reached */
+#define	ATMEL_US_TXBUFE		BIT(11)	/* Transmission Buffer Empty */
+#define	ATMEL_US_RXBUFF		BIT(12)	/* Reception Buffer Full */
+#define	ATMEL_US_NACK		BIT(13)	/* Non Acknowledge */
+#define	ATMEL_US_RIIC		BIT(16)	/* Ring Indicator Input Change */
+#define	ATMEL_US_DSRIC		BIT(17)	/* Data Set Ready Input Change */
+#define	ATMEL_US_DCDIC		BIT(18)	/* Data Carrier Detect Input Change */
+#define	ATMEL_US_CTSIC		BIT(19)	/* Clear to Send Input Change */
+#define	ATMEL_US_RI		BIT(20)	/* RI */
+#define	ATMEL_US_DSR		BIT(21)	/* DSR */
+#define	ATMEL_US_DCD		BIT(22)	/* DCD */
+#define	ATMEL_US_CTS		BIT(23)	/* CTS */
+
+#define ATMEL_US_IDR		0x0c	/* Interrupt Disable Register */
+#define ATMEL_US_IMR		0x10	/* Interrupt Mask Register */
+#define ATMEL_US_CSR		0x14	/* Channel Status Register */
+#define ATMEL_US_RHR		0x18	/* Receiver Holding Register */
+#define ATMEL_US_THR		0x1c	/* Transmitter Holding Register */
+#define	ATMEL_US_SYNH		BIT(15)	/* Transmit/Receive Sync */
+
+#define ATMEL_US_BRGR		0x20	/* Baud Rate Generator Register */
+#define	ATMEL_US_CD		GENMASK(15, 0)	/* Clock Divider */
+#define ATMEL_US_FP_OFFSET	16	/* Fractional Part */
+#define ATMEL_US_FP_MASK	0x7
+
+#define ATMEL_US_RTOR		0x24	/* Receiver Time-out Register for USART */
+#define ATMEL_UA_RTOR		0x28	/* Receiver Time-out Register for UART */
+#define	ATMEL_US_TO		GENMASK(15, 0)	/* Time-out Value */
+
+#define ATMEL_US_TTGR		0x28	/* Transmitter Timeguard Register */
+#define	ATMEL_US_TG		GENMASK(7, 0)	/* Timeguard Value */
+
+#define ATMEL_US_FIDI		0x40	/* FI DI Ratio Register */
+#define ATMEL_US_NER		0x44	/* Number of Errors Register */
+#define ATMEL_US_IF		0x4c	/* IrDA Filter Register */
+
+#define ATMEL_US_CMPR		0x90	/* Comparaison Register */
+#define ATMEL_US_FMR		0xa0	/* FIFO Mode Register */
+#define	ATMEL_US_TXRDYM(data)	FIELD_PREP(GENMASK(1, 0), (data))	/* TX Ready Mode */
+#define	ATMEL_US_RXRDYM(data)	FIELD_PREP(GENMASK(5, 4), (data))	/* RX Ready Mode */
+#define		ATMEL_US_ONE_DATA	0x0
+#define		ATMEL_US_TWO_DATA	0x1
+#define		ATMEL_US_FOUR_DATA	0x2
+#define	ATMEL_US_FRTSC		BIT(7)	/* FIFO RTS pin Control */
+#define	ATMEL_US_TXFTHRES(thr)	FIELD_PREP(GENMASK(13, 8), (thr))	/* TX FIFO Threshold */
+#define	ATMEL_US_RXFTHRES(thr)	FIELD_PREP(GENMASK(21, 16), (thr))	/* RX FIFO Threshold */
+#define	ATMEL_US_RXFTHRES2(thr)	FIELD_PREP(GENMASK(29, 24), (thr))	/* RX FIFO Threshold2 */
+
+#define ATMEL_US_FLR		0xa4	/* FIFO Level Register */
+#define	ATMEL_US_TXFL(reg)	FIELD_GET(GENMASK(5, 0), (reg))		/* TX FIFO Level */
+#define	ATMEL_US_RXFL(reg)	FIELD_GET(GENMASK(21, 16), (reg))	/* RX FIFO Level */
+
+#define ATMEL_US_FIER		0xa8	/* FIFO Interrupt Enable Register */
+#define ATMEL_US_FIDR		0xac	/* FIFO Interrupt Disable Register */
+#define ATMEL_US_FIMR		0xb0	/* FIFO Interrupt Mask Register */
+#define ATMEL_US_FESR		0xb4	/* FIFO Event Status Register */
+#define	ATMEL_US_TXFEF		BIT(0)	/* Transmit FIFO Empty Flag */
+#define	ATMEL_US_TXFFF		BIT(1)	/* Transmit FIFO Full Flag */
+#define	ATMEL_US_TXFTHF		BIT(2)	/* Transmit FIFO Threshold Flag */
+#define	ATMEL_US_RXFEF		BIT(3)	/* Receive FIFO Empty Flag */
+#define	ATMEL_US_RXFFF		BIT(4)	/* Receive FIFO Full Flag */
+#define	ATMEL_US_RXFTHF		BIT(5)	/* Receive FIFO Threshold Flag */
+#define	ATMEL_US_TXFPTEF	BIT(6)	/* Transmit FIFO Pointer Error Flag */
+#define	ATMEL_US_RXFPTEF	BIT(7)	/* Receive FIFO Pointer Error Flag */
+#define	ATMEL_US_TXFLOCK	BIT(8)	/* Transmit FIFO Lock (FESR only) */
+#define	ATMEL_US_RXFTHF2	BIT(9)	/* Receive FIFO Threshold Flag 2 */
+
+#define ATMEL_US_NAME		0xf0	/* Ip Name */
+#define ATMEL_US_VERSION	0xfc	/* Ip Version */
+
+#endif
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
new file mode 100644
index 000000000..0dd8cceb8
--- /dev/null
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -0,0 +1,926 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Derived from many drivers using generic_serial interface.
+ *
+ * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ *
+ *  Serial driver for BCM63xx integrated UART.
+ *
+ * Hardware flow control was _not_ tested since I only have RX/TX on
+ * my board.
+ */
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/clk.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/sysrq.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_bcm63xx.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#define BCM63XX_NR_UARTS	2
+
+static struct uart_port ports[BCM63XX_NR_UARTS];
+
+/*
+ * rx interrupt mask / stat
+ *
+ * mask:
+ *  - rx fifo full
+ *  - rx fifo above threshold
+ *  - rx fifo not empty for too long
+ */
+#define UART_RX_INT_MASK	(UART_IR_MASK(UART_IR_RXOVER) |		\
+				UART_IR_MASK(UART_IR_RXTHRESH) |	\
+				UART_IR_MASK(UART_IR_RXTIMEOUT))
+
+#define UART_RX_INT_STAT	(UART_IR_STAT(UART_IR_RXOVER) |		\
+				UART_IR_STAT(UART_IR_RXTHRESH) |	\
+				UART_IR_STAT(UART_IR_RXTIMEOUT))
+
+/*
+ * tx interrupt mask / stat
+ *
+ * mask:
+ * - tx fifo empty
+ * - tx fifo below threshold
+ */
+#define UART_TX_INT_MASK	(UART_IR_MASK(UART_IR_TXEMPTY) |	\
+				UART_IR_MASK(UART_IR_TXTRESH))
+
+#define UART_TX_INT_STAT	(UART_IR_STAT(UART_IR_TXEMPTY) |	\
+				UART_IR_STAT(UART_IR_TXTRESH))
+
+/*
+ * external input interrupt
+ *
+ * mask: any edge on CTS, DCD
+ */
+#define UART_EXTINP_INT_MASK	(UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
+				 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
+
+/*
+ * handy uart register accessor
+ */
+static inline unsigned int bcm_uart_readl(struct uart_port *port,
+					 unsigned int offset)
+{
+	return __raw_readl(port->membase + offset);
+}
+
+static inline void bcm_uart_writel(struct uart_port *port,
+				  unsigned int value, unsigned int offset)
+{
+	__raw_writel(value, port->membase + offset);
+}
+
+/*
+ * serial core request to check if uart tx fifo is empty
+ */
+static unsigned int bcm_uart_tx_empty(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
+}
+
+/*
+ * serial core request to set RTS and DTR pin state and loopback mode
+ */
+static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
+	/* invert of written value is reflected on the pin */
+	if (!(mctrl & TIOCM_DTR))
+		val |= UART_MCTL_DTR_MASK;
+	if (!(mctrl & TIOCM_RTS))
+		val |= UART_MCTL_RTS_MASK;
+	bcm_uart_writel(port, val, UART_MCTL_REG);
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	if (mctrl & TIOCM_LOOP)
+		val |= UART_CTL_LOOPBACK_MASK;
+	else
+		val &= ~UART_CTL_LOOPBACK_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * serial core request to return RI, CTS, DCD and DSR pin state
+ */
+static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
+{
+	unsigned int val, mctrl;
+
+	mctrl = 0;
+	val = bcm_uart_readl(port, UART_EXTINP_REG);
+	if (val & UART_EXTINP_RI_MASK)
+		mctrl |= TIOCM_RI;
+	if (val & UART_EXTINP_CTS_MASK)
+		mctrl |= TIOCM_CTS;
+	if (val & UART_EXTINP_DCD_MASK)
+		mctrl |= TIOCM_CD;
+	if (val & UART_EXTINP_DSR_MASK)
+		mctrl |= TIOCM_DSR;
+	return mctrl;
+}
+
+/*
+ * serial core request to disable tx ASAP (used for flow control)
+ */
+static void bcm_uart_stop_tx(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val &= ~(UART_CTL_TXEN_MASK);
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val &= ~UART_TX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to (re)enable tx
+ */
+static void bcm_uart_start_tx(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val |= UART_TX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val |= UART_CTL_TXEN_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * serial core request to stop rx, called before port shutdown
+ */
+static void bcm_uart_stop_rx(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val &= ~UART_RX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to enable modem status interrupt reporting
+ */
+static void bcm_uart_enable_ms(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val |= UART_IR_MASK(UART_IR_EXTIP);
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to start/stop emitting break char
+ */
+static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	unsigned long flags;
+	unsigned int val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	if (ctl)
+		val |= UART_CTL_XMITBRK_MASK;
+	else
+		val &= ~UART_CTL_XMITBRK_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * return port type in string format
+ */
+static const char *bcm_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
+}
+
+/*
+ * read all chars in rx fifo and send them to core
+ */
+static void bcm_uart_do_rx(struct uart_port *port)
+{
+	struct tty_port *tty_port = &port->state->port;
+	unsigned int max_count;
+
+	/* limit number of char read in interrupt, should not be
+	 * higher than fifo size anyway since we're much faster than
+	 * serial port */
+	max_count = 32;
+	do {
+		unsigned int iestat, c, cstat;
+		char flag;
+
+		/* get overrun/fifo empty information from ier
+		 * register */
+		iestat = bcm_uart_readl(port, UART_IR_REG);
+
+		if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
+			unsigned int val;
+
+			/* fifo reset is required to clear
+			 * interrupt */
+			val = bcm_uart_readl(port, UART_CTL_REG);
+			val |= UART_CTL_RSTRXFIFO_MASK;
+			bcm_uart_writel(port, val, UART_CTL_REG);
+
+			port->icount.overrun++;
+			tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
+		}
+
+		if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
+			break;
+
+		cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
+		port->icount.rx++;
+		flag = TTY_NORMAL;
+		c &= 0xff;
+
+		if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
+			/* do stats first */
+			if (cstat & UART_FIFO_BRKDET_MASK) {
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			}
+
+			if (cstat & UART_FIFO_PARERR_MASK)
+				port->icount.parity++;
+			if (cstat & UART_FIFO_FRAMEERR_MASK)
+				port->icount.frame++;
+
+			/* update flag wrt read_status_mask */
+			cstat &= port->read_status_mask;
+			if (cstat & UART_FIFO_BRKDET_MASK)
+				flag = TTY_BREAK;
+			if (cstat & UART_FIFO_FRAMEERR_MASK)
+				flag = TTY_FRAME;
+			if (cstat & UART_FIFO_PARERR_MASK)
+				flag = TTY_PARITY;
+		}
+
+		if (uart_handle_sysrq_char(port, c))
+			continue;
+
+
+		if ((cstat & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tty_port, c, flag);
+
+	} while (--max_count);
+
+	tty_flip_buffer_push(tty_port);
+}
+
+/*
+ * fill tx fifo with chars to send, stop when fifo is about to be full
+ * or when all chars have been sent.
+ */
+static void bcm_uart_do_tx(struct uart_port *port)
+{
+	unsigned int val;
+	bool pending;
+	u8 ch;
+
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
+
+	pending = uart_port_tx_limited(port, ch, port->fifosize - val,
+		true,
+		bcm_uart_writel(port, ch, UART_FIFO_REG),
+		({}));
+	if (pending)
+		return;
+
+	/* nothing to send, disable transmit interrupt */
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val &= ~UART_TX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * process uart interrupt
+ */
+static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port;
+	unsigned int irqstat;
+
+	port = dev_id;
+	spin_lock(&port->lock);
+
+	irqstat = bcm_uart_readl(port, UART_IR_REG);
+	if (irqstat & UART_RX_INT_STAT)
+		bcm_uart_do_rx(port);
+
+	if (irqstat & UART_TX_INT_STAT)
+		bcm_uart_do_tx(port);
+
+	if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
+		unsigned int estat;
+
+		estat = bcm_uart_readl(port, UART_EXTINP_REG);
+		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
+			uart_handle_cts_change(port,
+					       estat & UART_EXTINP_CTS_MASK);
+		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
+			uart_handle_dcd_change(port,
+					       estat & UART_EXTINP_DCD_MASK);
+	}
+
+	spin_unlock(&port->lock);
+	return IRQ_HANDLED;
+}
+
+/*
+ * enable rx & tx operation on uart
+ */
+static void bcm_uart_enable(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * disable rx & tx operation on uart
+ */
+static void bcm_uart_disable(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
+		 UART_CTL_RXEN_MASK);
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * clear all unread data in rx fifo and unsent data in tx fifo
+ */
+static void bcm_uart_flush(struct uart_port *port)
+{
+	unsigned int val;
+
+	/* empty rx and tx fifo */
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	/* read any pending char to make sure all irq status are
+	 * cleared */
+	(void)bcm_uart_readl(port, UART_FIFO_REG);
+}
+
+/*
+ * serial core request to initialize uart and start rx operation
+ */
+static int bcm_uart_startup(struct uart_port *port)
+{
+	unsigned int val;
+	int ret;
+
+	/* mask all irq and flush port */
+	bcm_uart_disable(port);
+	bcm_uart_writel(port, 0, UART_IR_REG);
+	bcm_uart_flush(port);
+
+	/* clear any pending external input interrupt */
+	(void)bcm_uart_readl(port, UART_EXTINP_REG);
+
+	/* set rx/tx fifo thresh to fifo half size */
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
+	val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
+	val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
+	bcm_uart_writel(port, val, UART_MCTL_REG);
+
+	/* set rx fifo timeout to 1 char time */
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val &= ~UART_CTL_RXTMOUTCNT_MASK;
+	val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	/* report any edge on dcd and cts */
+	val = UART_EXTINP_INT_MASK;
+	val |= UART_EXTINP_DCD_NOSENSE_MASK;
+	val |= UART_EXTINP_CTS_NOSENSE_MASK;
+	bcm_uart_writel(port, val, UART_EXTINP_REG);
+
+	/* register irq and enable rx interrupts */
+	ret = request_irq(port->irq, bcm_uart_interrupt, 0,
+			  dev_name(port->dev), port);
+	if (ret)
+		return ret;
+	bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
+	bcm_uart_enable(port);
+	return 0;
+}
+
+/*
+ * serial core request to flush & disable uart
+ */
+static void bcm_uart_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	bcm_uart_writel(port, 0, UART_IR_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	bcm_uart_disable(port);
+	bcm_uart_flush(port);
+	free_irq(port->irq, port);
+}
+
+/*
+ * serial core request to change current uart setting
+ */
+static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
+				 const struct ktermios *old)
+{
+	unsigned int ctl, baud, quot, ier;
+	unsigned long flags;
+	int tries;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Drain the hot tub fully before we power it off for the winter. */
+	for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
+		mdelay(10);
+
+	/* disable uart while changing speed */
+	bcm_uart_disable(port);
+	bcm_uart_flush(port);
+
+	/* update Control register */
+	ctl = bcm_uart_readl(port, UART_CTL_REG);
+	ctl &= ~UART_CTL_BITSPERSYM_MASK;
+
+	switch (new->c_cflag & CSIZE) {
+	case CS5:
+		ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	case CS6:
+		ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	case CS7:
+		ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	default:
+		ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	}
+
+	ctl &= ~UART_CTL_STOPBITS_MASK;
+	if (new->c_cflag & CSTOPB)
+		ctl |= UART_CTL_STOPBITS_2;
+	else
+		ctl |= UART_CTL_STOPBITS_1;
+
+	ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
+	if (new->c_cflag & PARENB)
+		ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
+	ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
+	if (new->c_cflag & PARODD)
+		ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
+	bcm_uart_writel(port, ctl, UART_CTL_REG);
+
+	/* update Baudword register */
+	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+	quot = uart_get_divisor(port, baud) - 1;
+	bcm_uart_writel(port, quot, UART_BAUD_REG);
+
+	/* update Interrupt register */
+	ier = bcm_uart_readl(port, UART_IR_REG);
+
+	ier &= ~UART_IR_MASK(UART_IR_EXTIP);
+	if (UART_ENABLE_MS(port, new->c_cflag))
+		ier |= UART_IR_MASK(UART_IR_EXTIP);
+
+	bcm_uart_writel(port, ier, UART_IR_REG);
+
+	/* update read/ignore mask */
+	port->read_status_mask = UART_FIFO_VALID_MASK;
+	if (new->c_iflag & INPCK) {
+		port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
+		port->read_status_mask |= UART_FIFO_PARERR_MASK;
+	}
+	if (new->c_iflag & (IGNBRK | BRKINT))
+		port->read_status_mask |= UART_FIFO_BRKDET_MASK;
+
+	port->ignore_status_mask = 0;
+	if (new->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
+	if (new->c_iflag & IGNBRK)
+		port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
+	if (!(new->c_cflag & CREAD))
+		port->ignore_status_mask |= UART_FIFO_VALID_MASK;
+
+	uart_update_timeout(port, new->c_cflag, baud);
+	bcm_uart_enable(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * serial core request to claim uart iomem
+ */
+static int bcm_uart_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+/*
+ * serial core request to release uart iomem
+ */
+static void bcm_uart_release_port(struct uart_port *port)
+{
+	/* Nothing to release ... */
+}
+
+/*
+ * serial core request to do any port required autoconfiguration
+ */
+static void bcm_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		if (bcm_uart_request_port(port))
+			return;
+		port->type = PORT_BCM63XX;
+	}
+}
+
+/*
+ * serial core request to check that port information in serinfo are
+ * suitable
+ */
+static int bcm_uart_verify_port(struct uart_port *port,
+				struct serial_struct *serinfo)
+{
+	if (port->type != PORT_BCM63XX)
+		return -EINVAL;
+	if (port->irq != serinfo->irq)
+		return -EINVAL;
+	if (port->iotype != serinfo->io_type)
+		return -EINVAL;
+	if (port->mapbase != (unsigned long)serinfo->iomem_base)
+		return -EINVAL;
+	return 0;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * return true when outstanding tx equals fifo size
+ */
+static bool bcm_uart_tx_full(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
+	return !(port->fifosize - val);
+}
+
+static int bcm_uart_poll_get_char(struct uart_port *port)
+{
+	unsigned int iestat;
+
+	iestat = bcm_uart_readl(port, UART_IR_REG);
+	if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
+		return NO_POLL_CHAR;
+
+	return bcm_uart_readl(port, UART_FIFO_REG);
+}
+
+static void bcm_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	while (bcm_uart_tx_full(port)) {
+		cpu_relax();
+	}
+
+	bcm_uart_writel(port, c, UART_FIFO_REG);
+}
+#endif
+
+/* serial core callbacks */
+static const struct uart_ops bcm_uart_ops = {
+	.tx_empty	= bcm_uart_tx_empty,
+	.get_mctrl	= bcm_uart_get_mctrl,
+	.set_mctrl	= bcm_uart_set_mctrl,
+	.start_tx	= bcm_uart_start_tx,
+	.stop_tx	= bcm_uart_stop_tx,
+	.stop_rx	= bcm_uart_stop_rx,
+	.enable_ms	= bcm_uart_enable_ms,
+	.break_ctl	= bcm_uart_break_ctl,
+	.startup	= bcm_uart_startup,
+	.shutdown	= bcm_uart_shutdown,
+	.set_termios	= bcm_uart_set_termios,
+	.type		= bcm_uart_type,
+	.release_port	= bcm_uart_release_port,
+	.request_port	= bcm_uart_request_port,
+	.config_port	= bcm_uart_config_port,
+	.verify_port	= bcm_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char  = bcm_uart_poll_get_char,
+	.poll_put_char  = bcm_uart_poll_put_char,
+#endif
+};
+
+
+
+#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
+static void wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int tmout;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	tmout = 10000;
+	while (--tmout) {
+		unsigned int val;
+
+		val = bcm_uart_readl(port, UART_IR_REG);
+		if (val & UART_IR_STAT(UART_IR_TXEMPTY))
+			break;
+		udelay(1);
+	}
+
+	/* Wait up to 1s for flow control if necessary */
+	if (port->flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		while (--tmout) {
+			unsigned int val;
+
+			val = bcm_uart_readl(port, UART_EXTINP_REG);
+			if (val & UART_EXTINP_CTS_MASK)
+				break;
+			udelay(1);
+		}
+	}
+}
+
+/*
+ * output given char
+ */
+static void bcm_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	wait_for_xmitr(port);
+	bcm_uart_writel(port, ch, UART_FIFO_REG);
+}
+
+/*
+ * console core request to output given string
+ */
+static void bcm_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	struct uart_port *port;
+	unsigned long flags;
+	int locked;
+
+	port = &ports[co->index];
+
+	local_irq_save(flags);
+	if (port->sysrq) {
+		/* bcm_uart_interrupt() already took the lock */
+		locked = 0;
+	} else if (oops_in_progress) {
+		locked = spin_trylock(&port->lock);
+	} else {
+		spin_lock(&port->lock);
+		locked = 1;
+	}
+
+	/* call helper to deal with \r\n */
+	uart_console_write(port, s, count, bcm_console_putchar);
+
+	/* and wait for char to be transmitted */
+	wait_for_xmitr(port);
+
+	if (locked)
+		spin_unlock(&port->lock);
+	local_irq_restore(flags);
+}
+
+/*
+ * console core request to setup given console, find matching uart
+ * port and setup it.
+ */
+static int bcm_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
+		return -EINVAL;
+	port = &ports[co->index];
+	if (!port->membase)
+		return -ENODEV;
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver bcm_uart_driver;
+
+static struct console bcm63xx_console = {
+	.name		= "ttyS",
+	.write		= bcm_console_write,
+	.device		= uart_console_device,
+	.setup		= bcm_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &bcm_uart_driver,
+};
+
+static int __init bcm63xx_console_init(void)
+{
+	register_console(&bcm63xx_console);
+	return 0;
+}
+
+console_initcall(bcm63xx_console_init);
+
+static void bcm_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, bcm_console_putchar);
+	wait_for_xmitr(&dev->port);
+}
+
+static int __init bcm_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = bcm_early_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
+
+#define BCM63XX_CONSOLE	(&bcm63xx_console)
+#else
+#define BCM63XX_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
+
+static struct uart_driver bcm_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "bcm63xx_uart",
+	.dev_name	= "ttyS",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= BCM63XX_NR_UARTS,
+	.cons		= BCM63XX_CONSOLE,
+};
+
+/*
+ * platform driver probe/remove callback
+ */
+static int bcm_uart_probe(struct platform_device *pdev)
+{
+	struct resource *res_mem;
+	struct uart_port *port;
+	struct clk *clk;
+	int ret;
+
+	if (pdev->dev.of_node) {
+		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+
+		if (pdev->id < 0)
+			pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
+	}
+
+	if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
+		return -EINVAL;
+
+	port = &ports[pdev->id];
+	if (port->membase)
+		return -EBUSY;
+	memset(port, 0, sizeof(*port));
+
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+	port->mapbase = res_mem->start;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	port->irq = ret;
+
+	clk = clk_get(&pdev->dev, "refclk");
+	if (IS_ERR(clk) && pdev->dev.of_node)
+		clk = of_clk_get(pdev->dev.of_node, 0);
+
+	if (IS_ERR(clk))
+		return -ENODEV;
+
+	port->iotype = UPIO_MEM;
+	port->ops = &bcm_uart_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
+	port->fifosize = 16;
+	port->uartclk = clk_get_rate(clk) / 2;
+	port->line = pdev->id;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE);
+	clk_put(clk);
+
+	ret = uart_add_one_port(&bcm_uart_driver, port);
+	if (ret) {
+		ports[pdev->id].membase = NULL;
+		return ret;
+	}
+	platform_set_drvdata(pdev, port);
+	return 0;
+}
+
+static int bcm_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port;
+
+	port = platform_get_drvdata(pdev);
+	uart_remove_one_port(&bcm_uart_driver, port);
+	/* mark port as free */
+	ports[pdev->id].membase = NULL;
+	return 0;
+}
+
+static const struct of_device_id bcm63xx_of_match[] = {
+	{ .compatible = "brcm,bcm6345-uart" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
+
+/*
+ * platform driver stuff
+ */
+static struct platform_driver bcm_uart_platform_driver = {
+	.probe	= bcm_uart_probe,
+	.remove	= bcm_uart_remove,
+	.driver	= {
+		.name  = "bcm63xx_uart",
+		.of_match_table = bcm63xx_of_match,
+	},
+};
+
+static int __init bcm_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&bcm_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&bcm_uart_platform_driver);
+	if (ret)
+		uart_unregister_driver(&bcm_uart_driver);
+
+	return ret;
+}
+
+static void __exit bcm_uart_exit(void)
+{
+	platform_driver_unregister(&bcm_uart_platform_driver);
+	uart_unregister_driver(&bcm_uart_driver);
+}
+
+module_init(bcm_uart_init);
+module_exit(bcm_uart_exit);
+
+MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
+MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
new file mode 100644
index 000000000..55d19937e
--- /dev/null
+++ b/drivers/tty/serial/clps711x.c
@@ -0,0 +1,563 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for CLPS711x serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright 1999 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/clps711x.h>
+
+#include "serial_mctrl_gpio.h"
+
+#define UART_CLPS711X_DEVNAME	"ttyCL"
+#define UART_CLPS711X_NR	2
+#define UART_CLPS711X_MAJOR	204
+#define UART_CLPS711X_MINOR	40
+
+#define UARTDR_OFFSET		(0x00)
+#define UBRLCR_OFFSET		(0x40)
+
+#define UARTDR_FRMERR		(1 << 8)
+#define UARTDR_PARERR		(1 << 9)
+#define UARTDR_OVERR		(1 << 10)
+
+#define UBRLCR_BAUD_MASK	((1 << 12) - 1)
+#define UBRLCR_BREAK		(1 << 12)
+#define UBRLCR_PRTEN		(1 << 13)
+#define UBRLCR_EVENPRT		(1 << 14)
+#define UBRLCR_XSTOP		(1 << 15)
+#define UBRLCR_FIFOEN		(1 << 16)
+#define UBRLCR_WRDLEN5		(0 << 17)
+#define UBRLCR_WRDLEN6		(1 << 17)
+#define UBRLCR_WRDLEN7		(2 << 17)
+#define UBRLCR_WRDLEN8		(3 << 17)
+#define UBRLCR_WRDLEN_MASK	(3 << 17)
+
+struct clps711x_port {
+	struct uart_port	port;
+	unsigned int		tx_enabled;
+	int			rx_irq;
+	struct regmap		*syscon;
+	struct mctrl_gpios	*gpios;
+};
+
+static struct uart_driver clps711x_uart = {
+	.owner		= THIS_MODULE,
+	.driver_name	= UART_CLPS711X_DEVNAME,
+	.dev_name	= UART_CLPS711X_DEVNAME,
+	.major		= UART_CLPS711X_MAJOR,
+	.minor		= UART_CLPS711X_MINOR,
+	.nr		= UART_CLPS711X_NR,
+};
+
+static void uart_clps711x_stop_tx(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	if (s->tx_enabled) {
+		disable_irq(port->irq);
+		s->tx_enabled = 0;
+	}
+}
+
+static void uart_clps711x_start_tx(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	if (!s->tx_enabled) {
+		s->tx_enabled = 1;
+		enable_irq(port->irq);
+	}
+}
+
+static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	unsigned int status;
+	u16 ch;
+	u8 flg;
+
+	for (;;) {
+		u32 sysflg = 0;
+
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+		if (sysflg & SYSFLG_URXFE)
+			break;
+
+		ch = readw(port->membase + UARTDR_OFFSET);
+		status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
+		ch &= 0xff;
+
+		port->icount.rx++;
+		flg = TTY_NORMAL;
+
+		if (unlikely(status)) {
+			if (status & UARTDR_PARERR)
+				port->icount.parity++;
+			else if (status & UARTDR_FRMERR)
+				port->icount.frame++;
+			else if (status & UARTDR_OVERR)
+				port->icount.overrun++;
+
+			status &= port->read_status_mask;
+
+			if (status & UARTDR_PARERR)
+				flg = TTY_PARITY;
+			else if (status & UARTDR_FRMERR)
+				flg = TTY_FRAME;
+			else if (status & UARTDR_OVERR)
+				flg = TTY_OVERRUN;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		if (status & port->ignore_status_mask)
+			continue;
+
+		uart_insert_char(port, status, UARTDR_OVERR, ch, flg);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (port->x_char) {
+		writew(port->x_char, port->membase + UARTDR_OFFSET);
+		port->icount.tx++;
+		port->x_char = 0;
+		return IRQ_HANDLED;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		if (s->tx_enabled) {
+			disable_irq_nosync(port->irq);
+			s->tx_enabled = 0;
+		}
+		return IRQ_HANDLED;
+	}
+
+	while (!uart_circ_empty(xmit)) {
+		u32 sysflg = 0;
+
+		writew(xmit->buf[xmit->tail], port->membase + UARTDR_OFFSET);
+		uart_xmit_advance(port, 1);
+
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+		if (sysflg & SYSFLG_UTXFF)
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	u32 sysflg = 0;
+
+	regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+
+	return (sysflg & SYSFLG_UBUSY) ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
+{
+	unsigned int result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	return mctrl_gpio_get(s->gpios, &result);
+}
+
+static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	mctrl_gpio_set(s->gpios, mctrl);
+}
+
+static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned int ubrlcr;
+
+	ubrlcr = readl(port->membase + UBRLCR_OFFSET);
+	if (break_state)
+		ubrlcr |= UBRLCR_BREAK;
+	else
+		ubrlcr &= ~UBRLCR_BREAK;
+	writel(ubrlcr, port->membase + UBRLCR_OFFSET);
+}
+
+static void uart_clps711x_set_ldisc(struct uart_port *port,
+				    struct ktermios *termios)
+{
+	if (!port->line) {
+		struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+		regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON1_SIREN,
+				   (termios->c_line == N_IRDA) ? SYSCON1_SIREN : 0);
+	}
+}
+
+static int uart_clps711x_startup(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	/* Disable break */
+	writel(readl(port->membase + UBRLCR_OFFSET) & ~UBRLCR_BREAK,
+	       port->membase + UBRLCR_OFFSET);
+
+	/* Enable the port */
+	return regmap_update_bits(s->syscon, SYSCON_OFFSET,
+				  SYSCON_UARTEN, SYSCON_UARTEN);
+}
+
+static void uart_clps711x_shutdown(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	/* Disable the port */
+	regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
+}
+
+static void uart_clps711x_set_termios(struct uart_port *port,
+				      struct ktermios *termios,
+				      const struct ktermios *old)
+{
+	u32 ubrlcr;
+	unsigned int baud, quot;
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+	termios->c_iflag &= ~(BRKINT | IGNBRK);
+
+	/* Ask the core to calculate the divisor for us */
+	baud = uart_get_baud_rate(port, termios, old, port->uartclk / 4096,
+						      port->uartclk / 16);
+	quot = uart_get_divisor(port, baud);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		ubrlcr = UBRLCR_WRDLEN5;
+		break;
+	case CS6:
+		ubrlcr = UBRLCR_WRDLEN6;
+		break;
+	case CS7:
+		ubrlcr = UBRLCR_WRDLEN7;
+		break;
+	case CS8:
+	default:
+		ubrlcr = UBRLCR_WRDLEN8;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		ubrlcr |= UBRLCR_XSTOP;
+
+	if (termios->c_cflag & PARENB) {
+		ubrlcr |= UBRLCR_PRTEN;
+		if (!(termios->c_cflag & PARODD))
+			ubrlcr |= UBRLCR_EVENPRT;
+	}
+
+	/* Enable FIFO */
+	ubrlcr |= UBRLCR_FIFOEN;
+
+	/* Set read status mask */
+	port->read_status_mask = UARTDR_OVERR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= UARTDR_OVERR | UARTDR_PARERR |
+					    UARTDR_FRMERR;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	writel(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
+}
+
+static const char *uart_clps711x_type(struct uart_port *port)
+{
+	return (port->type == PORT_CLPS711X) ? "CLPS711X" : NULL;
+}
+
+static void uart_clps711x_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_CLPS711X;
+}
+
+static void uart_clps711x_nop_void(struct uart_port *port)
+{
+}
+
+static int uart_clps711x_nop_int(struct uart_port *port)
+{
+	return 0;
+}
+
+static const struct uart_ops uart_clps711x_ops = {
+	.tx_empty	= uart_clps711x_tx_empty,
+	.set_mctrl	= uart_clps711x_set_mctrl,
+	.get_mctrl	= uart_clps711x_get_mctrl,
+	.stop_tx	= uart_clps711x_stop_tx,
+	.start_tx	= uart_clps711x_start_tx,
+	.stop_rx	= uart_clps711x_nop_void,
+	.break_ctl	= uart_clps711x_break_ctl,
+	.set_ldisc	= uart_clps711x_set_ldisc,
+	.startup	= uart_clps711x_startup,
+	.shutdown	= uart_clps711x_shutdown,
+	.set_termios	= uart_clps711x_set_termios,
+	.type		= uart_clps711x_type,
+	.config_port	= uart_clps711x_config_port,
+	.release_port	= uart_clps711x_nop_void,
+	.request_port	= uart_clps711x_nop_int,
+};
+
+#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
+static void uart_clps711x_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	u32 sysflg = 0;
+
+	/* Wait for FIFO is not full */
+	do {
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+	} while (sysflg & SYSFLG_UTXFF);
+
+	writew(ch, port->membase + UARTDR_OFFSET);
+}
+
+static void uart_clps711x_console_write(struct console *co, const char *c,
+					unsigned n)
+{
+	struct uart_port *port = clps711x_uart.state[co->index].uart_port;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	u32 sysflg = 0;
+
+	uart_console_write(port, c, n, uart_clps711x_console_putchar);
+
+	/* Wait for transmitter to become empty */
+	do {
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+	} while (sysflg & SYSFLG_UBUSY);
+}
+
+static int uart_clps711x_console_setup(struct console *co, char *options)
+{
+	int baud = 38400, bits = 8, parity = 'n', flow = 'n';
+	int ret, index = co->index;
+	struct clps711x_port *s;
+	struct uart_port *port;
+	unsigned int quot;
+	u32 ubrlcr;
+
+	if (index < 0 || index >= UART_CLPS711X_NR)
+		return -EINVAL;
+
+	port = clps711x_uart.state[index].uart_port;
+	if (!port)
+		return -ENODEV;
+
+	s = dev_get_drvdata(port->dev);
+
+	if (!options) {
+		u32 syscon = 0;
+
+		regmap_read(s->syscon, SYSCON_OFFSET, &syscon);
+		if (syscon & SYSCON_UARTEN) {
+			ubrlcr = readl(port->membase + UBRLCR_OFFSET);
+
+			if (ubrlcr & UBRLCR_PRTEN) {
+				if (ubrlcr & UBRLCR_EVENPRT)
+					parity = 'e';
+				else
+					parity = 'o';
+			}
+
+			if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
+				bits = 7;
+
+			quot = ubrlcr & UBRLCR_BAUD_MASK;
+			baud = port->uartclk / (16 * (quot + 1));
+		}
+	} else
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	ret = uart_set_options(port, co, baud, parity, bits, flow);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(s->syscon, SYSCON_OFFSET,
+				  SYSCON_UARTEN, SYSCON_UARTEN);
+}
+
+static struct console clps711x_console = {
+	.name	= UART_CLPS711X_DEVNAME,
+	.device	= uart_console_device,
+	.write	= uart_clps711x_console_write,
+	.setup	= uart_clps711x_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+#endif
+
+static int uart_clps711x_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct clps711x_port *s;
+	struct resource *res;
+	struct clk *uart_clk;
+	int irq, ret;
+
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	uart_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(uart_clk))
+		return PTR_ERR(uart_clk);
+
+	s->port.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(s->port.membase))
+		return PTR_ERR(s->port.membase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	s->port.irq = irq;
+
+	s->rx_irq = platform_get_irq(pdev, 1);
+	if (s->rx_irq < 0)
+		return s->rx_irq;
+
+	s->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
+	if (IS_ERR(s->syscon))
+		return PTR_ERR(s->syscon);
+
+	s->port.line		= of_alias_get_id(np, "serial");
+	s->port.dev		= &pdev->dev;
+	s->port.iotype		= UPIO_MEM32;
+	s->port.mapbase		= res->start;
+	s->port.type		= PORT_CLPS711X;
+	s->port.fifosize	= 16;
+	s->port.has_sysrq	= IS_ENABLED(CONFIG_SERIAL_CLPS711X_CONSOLE);
+	s->port.flags		= UPF_SKIP_TEST | UPF_FIXED_TYPE;
+	s->port.uartclk		= clk_get_rate(uart_clk);
+	s->port.ops		= &uart_clps711x_ops;
+
+	platform_set_drvdata(pdev, s);
+
+	s->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
+	if (IS_ERR(s->gpios))
+	    return PTR_ERR(s->gpios);
+
+	ret = uart_add_one_port(&clps711x_uart, &s->port);
+	if (ret)
+		return ret;
+
+	/* Disable port */
+	if (!uart_console(&s->port))
+		regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
+
+	s->tx_enabled = 1;
+
+	ret = devm_request_irq(&pdev->dev, s->port.irq, uart_clps711x_int_tx, 0,
+			       dev_name(&pdev->dev), &s->port);
+	if (ret) {
+		uart_remove_one_port(&clps711x_uart, &s->port);
+		return ret;
+	}
+
+	ret = devm_request_irq(&pdev->dev, s->rx_irq, uart_clps711x_int_rx, 0,
+			       dev_name(&pdev->dev), &s->port);
+	if (ret)
+		uart_remove_one_port(&clps711x_uart, &s->port);
+
+	return ret;
+}
+
+static int uart_clps711x_remove(struct platform_device *pdev)
+{
+	struct clps711x_port *s = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&clps711x_uart, &s->port);
+
+	return 0;
+}
+
+static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
+	{ .compatible = "cirrus,ep7209-uart", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, clps711x_uart_dt_ids);
+
+static struct platform_driver clps711x_uart_platform = {
+	.driver = {
+		.name		= "clps711x-uart",
+		.of_match_table	= of_match_ptr(clps711x_uart_dt_ids),
+	},
+	.probe	= uart_clps711x_probe,
+	.remove	= uart_clps711x_remove,
+};
+
+static int __init uart_clps711x_init(void)
+{
+	int ret;
+
+#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
+	clps711x_uart.cons = &clps711x_console;
+	clps711x_console.data = &clps711x_uart;
+#endif
+
+	ret = uart_register_driver(&clps711x_uart);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&clps711x_uart_platform);
+}
+module_init(uart_clps711x_init);
+
+static void __exit uart_clps711x_exit(void)
+{
+	platform_driver_unregister(&clps711x_uart_platform);
+	uart_unregister_driver(&clps711x_uart);
+}
+module_exit(uart_clps711x_exit);
+
+MODULE_AUTHOR("Deep Blue Solutions Ltd");
+MODULE_DESCRIPTION("CLPS711X serial driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/cpm_uart.c b/drivers/tty/serial/cpm_uart.c
new file mode 100644
index 000000000..626423022
--- /dev/null
+++ b/drivers/tty/serial/cpm_uart.c
@@ -0,0 +1,1612 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for CPM (SCC/SMC) serial ports; core driver
+ *
+ *  Based on arch/ppc/cpm2_io/uart.c by Dan Malek
+ *  Based on ppc8xx.c by Thomas Gleixner
+ *  Based on drivers/serial/amba.c by Russell King
+ *
+ *  Maintainer: Kumar Gala (galak@kernel.crashing.org) (CPM2)
+ *              Pantelis Antoniou (panto@intracom.gr) (CPM1)
+ *
+ *  Copyright (C) 2004, 2007 Freescale Semiconductor, Inc.
+ *            (C) 2004 Intracom, S.A.
+ *            (C) 2005-2006 MontaVista Software, Inc.
+ *		Vitaly Bordug <vbordug@ru.mvista.com>
+ */
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/device.h>
+#include <linux/memblock.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/gpio/consumer.h>
+#include <linux/clk.h>
+
+#include <sysdev/fsl_soc.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/delay.h>
+#include <asm/udbg.h>
+
+#include <linux/serial_core.h>
+#include <linux/kernel.h>
+
+#include "cpm_uart.h"
+
+
+/**************************************************************/
+
+static int  cpm_uart_tx_pump(struct uart_port *port);
+static void cpm_uart_initbd(struct uart_cpm_port *pinfo);
+
+/**************************************************************/
+
+#define HW_BUF_SPD_THRESHOLD    2400
+
+static void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
+{
+	cpm_command(port->command, cmd);
+}
+
+/*
+ * Check, if transmit buffers are processed
+*/
+static unsigned int cpm_uart_tx_empty(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	cbd_t __iomem *bdp = pinfo->tx_bd_base;
+	int ret = 0;
+
+	while (1) {
+		if (in_be16(&bdp->cbd_sc) & BD_SC_READY)
+			break;
+
+		if (in_be16(&bdp->cbd_sc) & BD_SC_WRAP) {
+			ret = TIOCSER_TEMT;
+			break;
+		}
+		bdp++;
+	}
+
+	pr_debug("CPM uart[%d]:tx_empty: %d\n", port->line, ret);
+
+	return ret;
+}
+
+static void cpm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+
+	if (pinfo->gpios[GPIO_RTS])
+		gpiod_set_value(pinfo->gpios[GPIO_RTS], !(mctrl & TIOCM_RTS));
+
+	if (pinfo->gpios[GPIO_DTR])
+		gpiod_set_value(pinfo->gpios[GPIO_DTR], !(mctrl & TIOCM_DTR));
+}
+
+static unsigned int cpm_uart_get_mctrl(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	unsigned int mctrl = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	if (pinfo->gpios[GPIO_CTS]) {
+		if (gpiod_get_value(pinfo->gpios[GPIO_CTS]))
+			mctrl &= ~TIOCM_CTS;
+	}
+
+	if (pinfo->gpios[GPIO_DSR]) {
+		if (gpiod_get_value(pinfo->gpios[GPIO_DSR]))
+			mctrl &= ~TIOCM_DSR;
+	}
+
+	if (pinfo->gpios[GPIO_DCD]) {
+		if (gpiod_get_value(pinfo->gpios[GPIO_DCD]))
+			mctrl &= ~TIOCM_CAR;
+	}
+
+	if (pinfo->gpios[GPIO_RI]) {
+		if (!gpiod_get_value(pinfo->gpios[GPIO_RI]))
+			mctrl |= TIOCM_RNG;
+	}
+
+	return mctrl;
+}
+
+/*
+ * Stop transmitter
+ */
+static void cpm_uart_stop_tx(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	smc_t __iomem *smcp = pinfo->smcp;
+	scc_t __iomem *sccp = pinfo->sccp;
+
+	pr_debug("CPM uart[%d]:stop tx\n", port->line);
+
+	if (IS_SMC(pinfo))
+		clrbits8(&smcp->smc_smcm, SMCM_TX);
+	else
+		clrbits16(&sccp->scc_sccm, UART_SCCM_TX);
+}
+
+/*
+ * Start transmitter
+ */
+static void cpm_uart_start_tx(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	smc_t __iomem *smcp = pinfo->smcp;
+	scc_t __iomem *sccp = pinfo->sccp;
+
+	pr_debug("CPM uart[%d]:start tx\n", port->line);
+
+	if (IS_SMC(pinfo)) {
+		if (in_8(&smcp->smc_smcm) & SMCM_TX)
+			return;
+	} else {
+		if (in_be16(&sccp->scc_sccm) & UART_SCCM_TX)
+			return;
+	}
+
+	if (cpm_uart_tx_pump(port) != 0) {
+		if (IS_SMC(pinfo)) {
+			setbits8(&smcp->smc_smcm, SMCM_TX);
+		} else {
+			setbits16(&sccp->scc_sccm, UART_SCCM_TX);
+		}
+	}
+}
+
+/*
+ * Stop receiver
+ */
+static void cpm_uart_stop_rx(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	smc_t __iomem *smcp = pinfo->smcp;
+	scc_t __iomem *sccp = pinfo->sccp;
+
+	pr_debug("CPM uart[%d]:stop rx\n", port->line);
+
+	if (IS_SMC(pinfo))
+		clrbits8(&smcp->smc_smcm, SMCM_RX);
+	else
+		clrbits16(&sccp->scc_sccm, UART_SCCM_RX);
+}
+
+/*
+ * Generate a break.
+ */
+static void cpm_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+
+	pr_debug("CPM uart[%d]:break ctrl, break_state: %d\n", port->line,
+		break_state);
+
+	if (break_state)
+		cpm_line_cr_cmd(pinfo, CPM_CR_STOP_TX);
+	else
+		cpm_line_cr_cmd(pinfo, CPM_CR_RESTART_TX);
+}
+
+/*
+ * Transmit characters, refill buffer descriptor, if possible
+ */
+static void cpm_uart_int_tx(struct uart_port *port)
+{
+	pr_debug("CPM uart[%d]:TX INT\n", port->line);
+
+	cpm_uart_tx_pump(port);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int serial_polled;
+#endif
+
+/*
+ * Receive characters
+ */
+static void cpm_uart_int_rx(struct uart_port *port)
+{
+	int i;
+	unsigned char ch;
+	u8 *cp;
+	struct tty_port *tport = &port->state->port;
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	cbd_t __iomem *bdp;
+	u16 status;
+	unsigned int flg;
+
+	pr_debug("CPM uart[%d]:RX INT\n", port->line);
+
+	/* Just loop through the closed BDs and copy the characters into
+	 * the buffer.
+	 */
+	bdp = pinfo->rx_cur;
+	for (;;) {
+#ifdef CONFIG_CONSOLE_POLL
+		if (unlikely(serial_polled)) {
+			serial_polled = 0;
+			return;
+		}
+#endif
+		/* get status */
+		status = in_be16(&bdp->cbd_sc);
+		/* If this one is empty, return happy */
+		if (status & BD_SC_EMPTY)
+			break;
+
+		/* get number of characters, and check spce in flip-buffer */
+		i = in_be16(&bdp->cbd_datlen);
+
+		/* If we have not enough room in tty flip buffer, then we try
+		 * later, which will be the next rx-interrupt or a timeout
+		 */
+		if (tty_buffer_request_room(tport, i) < i) {
+			printk(KERN_WARNING "No room in flip buffer\n");
+			return;
+		}
+
+		/* get pointer */
+		cp = cpm2cpu_addr(in_be32(&bdp->cbd_bufaddr), pinfo);
+
+		/* loop through the buffer */
+		while (i-- > 0) {
+			ch = *cp++;
+			port->icount.rx++;
+			flg = TTY_NORMAL;
+
+			if (status &
+			    (BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV))
+				goto handle_error;
+			if (uart_handle_sysrq_char(port, ch))
+				continue;
+#ifdef CONFIG_CONSOLE_POLL
+			if (unlikely(serial_polled)) {
+				serial_polled = 0;
+				return;
+			}
+#endif
+		      error_return:
+			tty_insert_flip_char(tport, ch, flg);
+
+		}		/* End while (i--) */
+
+		/* This BD is ready to be used again. Clear status. get next */
+		clrbits16(&bdp->cbd_sc, BD_SC_BR | BD_SC_FR | BD_SC_PR |
+		                        BD_SC_OV | BD_SC_ID);
+		setbits16(&bdp->cbd_sc, BD_SC_EMPTY);
+
+		if (in_be16(&bdp->cbd_sc) & BD_SC_WRAP)
+			bdp = pinfo->rx_bd_base;
+		else
+			bdp++;
+
+	} /* End for (;;) */
+
+	/* Write back buffer pointer */
+	pinfo->rx_cur = bdp;
+
+	/* activate BH processing */
+	tty_flip_buffer_push(tport);
+
+	return;
+
+	/* Error processing */
+
+      handle_error:
+	/* Statistics */
+	if (status & BD_SC_BR)
+		port->icount.brk++;
+	if (status & BD_SC_PR)
+		port->icount.parity++;
+	if (status & BD_SC_FR)
+		port->icount.frame++;
+	if (status & BD_SC_OV)
+		port->icount.overrun++;
+
+	/* Mask out ignored conditions */
+	status &= port->read_status_mask;
+
+	/* Handle the remaining ones */
+	if (status & BD_SC_BR)
+		flg = TTY_BREAK;
+	else if (status & BD_SC_PR)
+		flg = TTY_PARITY;
+	else if (status & BD_SC_FR)
+		flg = TTY_FRAME;
+
+	/* overrun does not affect the current character ! */
+	if (status & BD_SC_OV) {
+		ch = 0;
+		flg = TTY_OVERRUN;
+		/* We skip this buffer */
+		/* CHECK: Is really nothing senseful there */
+		/* ASSUMPTION: it contains nothing valid */
+		i = 0;
+	}
+	port->sysrq = 0;
+	goto error_return;
+}
+
+/*
+ * Asynchron mode interrupt handler
+ */
+static irqreturn_t cpm_uart_int(int irq, void *data)
+{
+	u8 events;
+	struct uart_port *port = data;
+	struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
+	smc_t __iomem *smcp = pinfo->smcp;
+	scc_t __iomem *sccp = pinfo->sccp;
+
+	pr_debug("CPM uart[%d]:IRQ\n", port->line);
+
+	if (IS_SMC(pinfo)) {
+		events = in_8(&smcp->smc_smce);
+		out_8(&smcp->smc_smce, events);
+		if (events & SMCM_BRKE)
+			uart_handle_break(port);
+		if (events & SMCM_RX)
+			cpm_uart_int_rx(port);
+		if (events & SMCM_TX)
+			cpm_uart_int_tx(port);
+	} else {
+		events = in_be16(&sccp->scc_scce);
+		out_be16(&sccp->scc_scce, events);
+		if (events & UART_SCCM_BRKE)
+			uart_handle_break(port);
+		if (events & UART_SCCM_RX)
+			cpm_uart_int_rx(port);
+		if (events & UART_SCCM_TX)
+			cpm_uart_int_tx(port);
+	}
+	return (events) ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int cpm_uart_startup(struct uart_port *port)
+{
+	int retval;
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+
+	pr_debug("CPM uart[%d]:startup\n", port->line);
+
+	/* If the port is not the console, make sure rx is disabled. */
+	if (!(pinfo->flags & FLAG_CONSOLE)) {
+		/* Disable UART rx */
+		if (IS_SMC(pinfo)) {
+			clrbits16(&pinfo->smcp->smc_smcmr, SMCMR_REN);
+			clrbits8(&pinfo->smcp->smc_smcm, SMCM_RX);
+		} else {
+			clrbits32(&pinfo->sccp->scc_gsmrl, SCC_GSMRL_ENR);
+			clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_RX);
+		}
+		cpm_uart_initbd(pinfo);
+		if (IS_SMC(pinfo)) {
+			out_be32(&pinfo->smcup->smc_rstate, 0);
+			out_be32(&pinfo->smcup->smc_tstate, 0);
+			out_be16(&pinfo->smcup->smc_rbptr,
+				 in_be16(&pinfo->smcup->smc_rbase));
+			out_be16(&pinfo->smcup->smc_tbptr,
+				 in_be16(&pinfo->smcup->smc_tbase));
+		} else {
+			cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+		}
+	}
+	/* Install interrupt handler. */
+	retval = request_irq(port->irq, cpm_uart_int, 0, "cpm_uart", port);
+	if (retval)
+		return retval;
+
+	/* Startup rx-int */
+	if (IS_SMC(pinfo)) {
+		setbits8(&pinfo->smcp->smc_smcm, SMCM_RX);
+		setbits16(&pinfo->smcp->smc_smcmr, (SMCMR_REN | SMCMR_TEN));
+	} else {
+		setbits16(&pinfo->sccp->scc_sccm, UART_SCCM_RX);
+		setbits32(&pinfo->sccp->scc_gsmrl, (SCC_GSMRL_ENR | SCC_GSMRL_ENT));
+	}
+
+	return 0;
+}
+
+inline void cpm_uart_wait_until_send(struct uart_cpm_port *pinfo)
+{
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule_timeout(pinfo->wait_closing);
+}
+
+/*
+ * Shutdown the uart
+ */
+static void cpm_uart_shutdown(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+
+	pr_debug("CPM uart[%d]:shutdown\n", port->line);
+
+	/* free interrupt handler */
+	free_irq(port->irq, port);
+
+	/* If the port is not the console, disable Rx and Tx. */
+	if (!(pinfo->flags & FLAG_CONSOLE)) {
+		/* Wait for all the BDs marked sent */
+		while(!cpm_uart_tx_empty(port)) {
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_timeout(2);
+		}
+
+		if (pinfo->wait_closing)
+			cpm_uart_wait_until_send(pinfo);
+
+		/* Stop uarts */
+		if (IS_SMC(pinfo)) {
+			smc_t __iomem *smcp = pinfo->smcp;
+			clrbits16(&smcp->smc_smcmr, SMCMR_REN | SMCMR_TEN);
+			clrbits8(&smcp->smc_smcm, SMCM_RX | SMCM_TX);
+		} else {
+			scc_t __iomem *sccp = pinfo->sccp;
+			clrbits32(&sccp->scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
+			clrbits16(&sccp->scc_sccm, UART_SCCM_TX | UART_SCCM_RX);
+		}
+
+		/* Shut them really down and reinit buffer descriptors */
+		if (IS_SMC(pinfo)) {
+			out_be16(&pinfo->smcup->smc_brkcr, 0);
+			cpm_line_cr_cmd(pinfo, CPM_CR_STOP_TX);
+		} else {
+			out_be16(&pinfo->sccup->scc_brkcr, 0);
+			cpm_line_cr_cmd(pinfo, CPM_CR_GRA_STOP_TX);
+		}
+
+		cpm_uart_initbd(pinfo);
+	}
+}
+
+static void cpm_uart_set_termios(struct uart_port *port,
+                                 struct ktermios *termios,
+                                 const struct ktermios *old)
+{
+	int baud;
+	unsigned long flags;
+	u16 cval, scval, prev_mode;
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	smc_t __iomem *smcp = pinfo->smcp;
+	scc_t __iomem *sccp = pinfo->sccp;
+	int maxidl;
+
+	pr_debug("CPM uart[%d]:set_termios\n", port->line);
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+	if (baud < HW_BUF_SPD_THRESHOLD || port->flags & UPF_LOW_LATENCY)
+		pinfo->rx_fifosize = 1;
+	else
+		pinfo->rx_fifosize = RX_BUF_SIZE;
+
+	/* MAXIDL is the timeout after which a receive buffer is closed
+	 * when not full if no more characters are received.
+	 * We calculate it from the baudrate so that the duration is
+	 * always the same at standard rates: about 4ms.
+	 */
+	maxidl = baud / 2400;
+	if (maxidl < 1)
+		maxidl = 1;
+	if (maxidl > 0x10)
+		maxidl = 0x10;
+
+	cval = 0;
+	scval = 0;
+
+	if (termios->c_cflag & CSTOPB) {
+		cval |= SMCMR_SL;	/* Two stops */
+		scval |= SCU_PSMR_SL;
+	}
+
+	if (termios->c_cflag & PARENB) {
+		cval |= SMCMR_PEN;
+		scval |= SCU_PSMR_PEN;
+		if (!(termios->c_cflag & PARODD)) {
+			cval |= SMCMR_PM_EVEN;
+			scval |= (SCU_PSMR_REVP | SCU_PSMR_TEVP);
+		}
+	}
+
+	/*
+	 * Update the timeout
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * Set up parity check flag
+	 */
+	port->read_status_mask = (BD_SC_EMPTY | BD_SC_OV);
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= BD_SC_FR | BD_SC_PR;
+	if ((termios->c_iflag & BRKINT) || (termios->c_iflag & PARMRK))
+		port->read_status_mask |= BD_SC_BR;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= BD_SC_PR | BD_SC_FR;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= BD_SC_BR;
+		/*
+		 * If we're ignore parity and break indicators, ignore
+		 * overruns too.  (For real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= BD_SC_OV;
+	}
+	/*
+	 * !!! ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->read_status_mask &= ~BD_SC_EMPTY;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (IS_SMC(pinfo)) {
+		unsigned int bits = tty_get_frame_size(termios->c_cflag);
+
+		/*
+		 * MRBLR can be changed while an SMC/SCC is operating only
+		 * if it is done in a single bus cycle with one 16-bit move
+		 * (not two 8-bit bus cycles back-to-back). This occurs when
+		 * the cp shifts control to the next RxBD, so the change does
+		 * not take effect immediately. To guarantee the exact RxBD
+		 * on which the change occurs, change MRBLR only while the
+		 * SMC/SCC receiver is disabled.
+		 */
+		out_be16(&pinfo->smcup->smc_mrblr, pinfo->rx_fifosize);
+		out_be16(&pinfo->smcup->smc_maxidl, maxidl);
+
+		/* Set the mode register.  We want to keep a copy of the
+		 * enables, because we want to put them back if they were
+		 * present.
+		 */
+		prev_mode = in_be16(&smcp->smc_smcmr) & (SMCMR_REN | SMCMR_TEN);
+		/* Output in *one* operation, so we don't interrupt RX/TX if they
+		 * were already enabled.
+		 * Character length programmed into the register is frame bits minus 1.
+		 */
+		out_be16(&smcp->smc_smcmr, smcr_mk_clen(bits - 1) | cval |
+					   SMCMR_SM_UART | prev_mode);
+	} else {
+		unsigned int bits = tty_get_char_size(termios->c_cflag);
+
+		out_be16(&pinfo->sccup->scc_genscc.scc_mrblr, pinfo->rx_fifosize);
+		out_be16(&pinfo->sccup->scc_maxidl, maxidl);
+		out_be16(&sccp->scc_psmr, (UART_LCR_WLEN(bits) << 12) | scval);
+	}
+
+	if (pinfo->clk)
+		clk_set_rate(pinfo->clk, baud);
+	else
+		cpm_setbrg(pinfo->brg - 1, baud);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *cpm_uart_type(struct uart_port *port)
+{
+	pr_debug("CPM uart[%d]:uart_type\n", port->line);
+
+	return port->type == PORT_CPM ? "CPM UART" : NULL;
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int cpm_uart_verify_port(struct uart_port *port,
+				struct serial_struct *ser)
+{
+	int ret = 0;
+
+	pr_debug("CPM uart[%d]:verify_port\n", port->line);
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_CPM)
+		ret = -EINVAL;
+	if (ser->irq < 0 || ser->irq >= nr_irqs)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	return ret;
+}
+
+/*
+ * Transmit characters, refill buffer descriptor, if possible
+ */
+static int cpm_uart_tx_pump(struct uart_port *port)
+{
+	cbd_t __iomem *bdp;
+	u8 *p;
+	int count;
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	/* Handle xon/xoff */
+	if (port->x_char) {
+		/* Pick next descriptor and fill from buffer */
+		bdp = pinfo->tx_cur;
+
+		p = cpm2cpu_addr(in_be32(&bdp->cbd_bufaddr), pinfo);
+
+		*p++ = port->x_char;
+
+		out_be16(&bdp->cbd_datlen, 1);
+		setbits16(&bdp->cbd_sc, BD_SC_READY);
+		/* Get next BD. */
+		if (in_be16(&bdp->cbd_sc) & BD_SC_WRAP)
+			bdp = pinfo->tx_bd_base;
+		else
+			bdp++;
+		pinfo->tx_cur = bdp;
+
+		port->icount.tx++;
+		port->x_char = 0;
+		return 1;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		cpm_uart_stop_tx(port);
+		return 0;
+	}
+
+	/* Pick next descriptor and fill from buffer */
+	bdp = pinfo->tx_cur;
+
+	while (!(in_be16(&bdp->cbd_sc) & BD_SC_READY) && !uart_circ_empty(xmit)) {
+		count = 0;
+		p = cpm2cpu_addr(in_be32(&bdp->cbd_bufaddr), pinfo);
+		while (count < pinfo->tx_fifosize) {
+			*p++ = xmit->buf[xmit->tail];
+			uart_xmit_advance(port, 1);
+			count++;
+			if (uart_circ_empty(xmit))
+				break;
+		}
+		out_be16(&bdp->cbd_datlen, count);
+		setbits16(&bdp->cbd_sc, BD_SC_READY);
+		/* Get next BD. */
+		if (in_be16(&bdp->cbd_sc) & BD_SC_WRAP)
+			bdp = pinfo->tx_bd_base;
+		else
+			bdp++;
+	}
+	pinfo->tx_cur = bdp;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit)) {
+		cpm_uart_stop_tx(port);
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * init buffer descriptors
+ */
+static void cpm_uart_initbd(struct uart_cpm_port *pinfo)
+{
+	int i;
+	u8 *mem_addr;
+	cbd_t __iomem *bdp;
+
+	pr_debug("CPM uart[%d]:initbd\n", pinfo->port.line);
+
+	/* Set the physical address of the host memory
+	 * buffers in the buffer descriptors, and the
+	 * virtual address for us to work with.
+	 */
+	mem_addr = pinfo->mem_addr;
+	bdp = pinfo->rx_cur = pinfo->rx_bd_base;
+	for (i = 0; i < (pinfo->rx_nrfifos - 1); i++, bdp++) {
+		out_be32(&bdp->cbd_bufaddr, cpu2cpm_addr(mem_addr, pinfo));
+		out_be16(&bdp->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
+		mem_addr += pinfo->rx_fifosize;
+	}
+
+	out_be32(&bdp->cbd_bufaddr, cpu2cpm_addr(mem_addr, pinfo));
+	out_be16(&bdp->cbd_sc, BD_SC_WRAP | BD_SC_EMPTY | BD_SC_INTRPT);
+
+	/* Set the physical address of the host memory
+	 * buffers in the buffer descriptors, and the
+	 * virtual address for us to work with.
+	 */
+	mem_addr = pinfo->mem_addr + L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize);
+	bdp = pinfo->tx_cur = pinfo->tx_bd_base;
+	for (i = 0; i < (pinfo->tx_nrfifos - 1); i++, bdp++) {
+		out_be32(&bdp->cbd_bufaddr, cpu2cpm_addr(mem_addr, pinfo));
+		out_be16(&bdp->cbd_sc, BD_SC_INTRPT);
+		mem_addr += pinfo->tx_fifosize;
+	}
+
+	out_be32(&bdp->cbd_bufaddr, cpu2cpm_addr(mem_addr, pinfo));
+	out_be16(&bdp->cbd_sc, BD_SC_WRAP | BD_SC_INTRPT);
+}
+
+static void cpm_uart_init_scc(struct uart_cpm_port *pinfo)
+{
+	scc_t __iomem *scp;
+	scc_uart_t __iomem *sup;
+
+	pr_debug("CPM uart[%d]:init_scc\n", pinfo->port.line);
+
+	scp = pinfo->sccp;
+	sup = pinfo->sccup;
+
+	/* Store address */
+	out_be16(&pinfo->sccup->scc_genscc.scc_rbase,
+	         (u8 __iomem *)pinfo->rx_bd_base - DPRAM_BASE);
+	out_be16(&pinfo->sccup->scc_genscc.scc_tbase,
+	         (u8 __iomem *)pinfo->tx_bd_base - DPRAM_BASE);
+
+	/* Set up the uart parameters in the
+	 * parameter ram.
+	 */
+
+	out_8(&sup->scc_genscc.scc_rfcr, CPMFCR_GBL | CPMFCR_EB);
+	out_8(&sup->scc_genscc.scc_tfcr, CPMFCR_GBL | CPMFCR_EB);
+
+	out_be16(&sup->scc_genscc.scc_mrblr, pinfo->rx_fifosize);
+	out_be16(&sup->scc_maxidl, 0x10);
+	out_be16(&sup->scc_brkcr, 1);
+	out_be16(&sup->scc_parec, 0);
+	out_be16(&sup->scc_frmec, 0);
+	out_be16(&sup->scc_nosec, 0);
+	out_be16(&sup->scc_brkec, 0);
+	out_be16(&sup->scc_uaddr1, 0);
+	out_be16(&sup->scc_uaddr2, 0);
+	out_be16(&sup->scc_toseq, 0);
+	out_be16(&sup->scc_char1, 0x8000);
+	out_be16(&sup->scc_char2, 0x8000);
+	out_be16(&sup->scc_char3, 0x8000);
+	out_be16(&sup->scc_char4, 0x8000);
+	out_be16(&sup->scc_char5, 0x8000);
+	out_be16(&sup->scc_char6, 0x8000);
+	out_be16(&sup->scc_char7, 0x8000);
+	out_be16(&sup->scc_char8, 0x8000);
+	out_be16(&sup->scc_rccm, 0xc0ff);
+
+	/* Send the CPM an initialize command.
+	 */
+	cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+
+	/* Set UART mode, 8 bit, no parity, one stop.
+	 * Enable receive and transmit.
+	 */
+	out_be32(&scp->scc_gsmrh, 0);
+	out_be32(&scp->scc_gsmrl,
+	         SCC_GSMRL_MODE_UART | SCC_GSMRL_TDCR_16 | SCC_GSMRL_RDCR_16);
+
+	/* Enable rx interrupts  and clear all pending events.  */
+	out_be16(&scp->scc_sccm, 0);
+	out_be16(&scp->scc_scce, 0xffff);
+	out_be16(&scp->scc_dsr, 0x7e7e);
+	out_be16(&scp->scc_psmr, 0x3000);
+
+	setbits32(&scp->scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
+}
+
+static void cpm_uart_init_smc(struct uart_cpm_port *pinfo)
+{
+	smc_t __iomem *sp;
+	smc_uart_t __iomem *up;
+
+	pr_debug("CPM uart[%d]:init_smc\n", pinfo->port.line);
+
+	sp = pinfo->smcp;
+	up = pinfo->smcup;
+
+	/* Store address */
+	out_be16(&pinfo->smcup->smc_rbase,
+	         (u8 __iomem *)pinfo->rx_bd_base - DPRAM_BASE);
+	out_be16(&pinfo->smcup->smc_tbase,
+	         (u8 __iomem *)pinfo->tx_bd_base - DPRAM_BASE);
+
+/*
+ *  In case SMC is being relocated...
+ */
+	out_be16(&up->smc_rbptr, in_be16(&pinfo->smcup->smc_rbase));
+	out_be16(&up->smc_tbptr, in_be16(&pinfo->smcup->smc_tbase));
+	out_be32(&up->smc_rstate, 0);
+	out_be32(&up->smc_tstate, 0);
+	out_be16(&up->smc_brkcr, 1);              /* number of break chars */
+	out_be16(&up->smc_brkec, 0);
+
+	/* Set up the uart parameters in the
+	 * parameter ram.
+	 */
+	out_8(&up->smc_rfcr, CPMFCR_GBL | CPMFCR_EB);
+	out_8(&up->smc_tfcr, CPMFCR_GBL | CPMFCR_EB);
+
+	/* Using idle character time requires some additional tuning.  */
+	out_be16(&up->smc_mrblr, pinfo->rx_fifosize);
+	out_be16(&up->smc_maxidl, 0x10);
+	out_be16(&up->smc_brklen, 0);
+	out_be16(&up->smc_brkec, 0);
+	out_be16(&up->smc_brkcr, 1);
+
+	/* Set UART mode, 8 bit, no parity, one stop.
+	 * Enable receive and transmit.
+	 */
+	out_be16(&sp->smc_smcmr, smcr_mk_clen(9) | SMCMR_SM_UART);
+
+	/* Enable only rx interrupts clear all pending events. */
+	out_8(&sp->smc_smcm, 0);
+	out_8(&sp->smc_smce, 0xff);
+
+	setbits16(&sp->smc_smcmr, SMCMR_REN | SMCMR_TEN);
+}
+
+/*
+ * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
+ * receive buffer descriptors from dual port ram, and a character
+ * buffer area from host mem. If we are allocating for the console we need
+ * to do it from bootmem
+ */
+static int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
+{
+	int dpmemsz, memsz;
+	u8 __iomem *dp_mem;
+	unsigned long dp_offset;
+	u8 *mem_addr;
+	dma_addr_t dma_addr = 0;
+
+	pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);
+
+	dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
+	dp_offset = cpm_muram_alloc(dpmemsz, 8);
+	if (IS_ERR_VALUE(dp_offset)) {
+		pr_err("%s: could not allocate buffer descriptors\n", __func__);
+		return -ENOMEM;
+	}
+
+	dp_mem = cpm_muram_addr(dp_offset);
+
+	memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
+	    L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
+	if (IS_ENABLED(CONFIG_CPM1) && is_con) {
+		/* was hostalloc but changed cause it blows away the */
+		/* large tlb mapping when pinning the kernel area    */
+		mem_addr = (u8 __force *)cpm_muram_addr(cpm_muram_alloc(memsz, 8));
+		dma_addr = cpm_muram_dma((void __iomem *)mem_addr);
+	} else if (is_con) {
+		mem_addr = kzalloc(memsz, GFP_NOWAIT);
+		dma_addr = virt_to_bus(mem_addr);
+	} else {
+		mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
+					      GFP_KERNEL);
+	}
+
+	if (!mem_addr) {
+		cpm_muram_free(dp_offset);
+		pr_err("%s: could not allocate coherent memory\n", __func__);
+		return -ENOMEM;
+	}
+
+	pinfo->dp_addr = dp_offset;
+	pinfo->mem_addr = mem_addr;
+	pinfo->dma_addr = dma_addr;
+	pinfo->mem_size = memsz;
+
+	pinfo->rx_buf = mem_addr;
+	pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
+						       * pinfo->rx_fifosize);
+
+	pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
+	pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;
+
+	return 0;
+}
+
+static void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
+{
+	dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
+							  pinfo->rx_fifosize) +
+			  L1_CACHE_ALIGN(pinfo->tx_nrfifos *
+					 pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
+			  pinfo->dma_addr);
+
+	cpm_muram_free(pinfo->dp_addr);
+}
+
+/*
+ * Initialize port. This is called from early_console stuff
+ * so we have to be careful here !
+ */
+static int cpm_uart_request_port(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	int ret;
+
+	pr_debug("CPM uart[%d]:request port\n", port->line);
+
+	if (pinfo->flags & FLAG_CONSOLE)
+		return 0;
+
+	if (IS_SMC(pinfo)) {
+		clrbits8(&pinfo->smcp->smc_smcm, SMCM_RX | SMCM_TX);
+		clrbits16(&pinfo->smcp->smc_smcmr, SMCMR_REN | SMCMR_TEN);
+	} else {
+		clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_TX | UART_SCCM_RX);
+		clrbits32(&pinfo->sccp->scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
+	}
+
+	ret = cpm_uart_allocbuf(pinfo, 0);
+
+	if (ret)
+		return ret;
+
+	cpm_uart_initbd(pinfo);
+	if (IS_SMC(pinfo))
+		cpm_uart_init_smc(pinfo);
+	else
+		cpm_uart_init_scc(pinfo);
+
+	return 0;
+}
+
+static void cpm_uart_release_port(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+
+	if (!(pinfo->flags & FLAG_CONSOLE))
+		cpm_uart_freebuf(pinfo);
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void cpm_uart_config_port(struct uart_port *port, int flags)
+{
+	pr_debug("CPM uart[%d]:config_port\n", port->line);
+
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_CPM;
+		cpm_uart_request_port(port);
+	}
+}
+
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_CPM_CONSOLE)
+/*
+ * Write a string to the serial port
+ * Note that this is called with interrupts already disabled
+ */
+static void cpm_uart_early_write(struct uart_cpm_port *pinfo,
+		const char *string, u_int count, bool handle_linefeed)
+{
+	unsigned int i;
+	cbd_t __iomem *bdp, *bdbase;
+	unsigned char *cpm_outp_addr;
+
+	/* Get the address of the host memory buffer.
+	 */
+	bdp = pinfo->tx_cur;
+	bdbase = pinfo->tx_bd_base;
+
+	/*
+	 * Now, do each character.  This is not as bad as it looks
+	 * since this is a holding FIFO and not a transmitting FIFO.
+	 * We could add the complexity of filling the entire transmit
+	 * buffer, but we would just wait longer between accesses......
+	 */
+	for (i = 0; i < count; i++, string++) {
+		/* Wait for transmitter fifo to empty.
+		 * Ready indicates output is ready, and xmt is doing
+		 * that, not that it is ready for us to send.
+		 */
+		while ((in_be16(&bdp->cbd_sc) & BD_SC_READY) != 0)
+			;
+
+		/* Send the character out.
+		 * If the buffer address is in the CPM DPRAM, don't
+		 * convert it.
+		 */
+		cpm_outp_addr = cpm2cpu_addr(in_be32(&bdp->cbd_bufaddr),
+					pinfo);
+		*cpm_outp_addr = *string;
+
+		out_be16(&bdp->cbd_datlen, 1);
+		setbits16(&bdp->cbd_sc, BD_SC_READY);
+
+		if (in_be16(&bdp->cbd_sc) & BD_SC_WRAP)
+			bdp = bdbase;
+		else
+			bdp++;
+
+		/* if a LF, also do CR... */
+		if (handle_linefeed && *string == 10) {
+			while ((in_be16(&bdp->cbd_sc) & BD_SC_READY) != 0)
+				;
+
+			cpm_outp_addr = cpm2cpu_addr(in_be32(&bdp->cbd_bufaddr),
+						pinfo);
+			*cpm_outp_addr = 13;
+
+			out_be16(&bdp->cbd_datlen, 1);
+			setbits16(&bdp->cbd_sc, BD_SC_READY);
+
+			if (in_be16(&bdp->cbd_sc) & BD_SC_WRAP)
+				bdp = bdbase;
+			else
+				bdp++;
+		}
+	}
+
+	/*
+	 * Finally, Wait for transmitter & holding register to empty
+	 *  and restore the IER
+	 */
+	while ((in_be16(&bdp->cbd_sc) & BD_SC_READY) != 0)
+		;
+
+	pinfo->tx_cur = bdp;
+}
+#endif
+
+#ifdef CONFIG_CONSOLE_POLL
+/* Serial polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+#define GDB_BUF_SIZE	512	/* power of 2, please */
+
+static char poll_buf[GDB_BUF_SIZE];
+static char *pollp;
+static int poll_chars;
+
+static int poll_wait_key(char *obuf, struct uart_cpm_port *pinfo)
+{
+	u_char		c, *cp;
+	volatile cbd_t	*bdp;
+	int		i;
+
+	/* Get the address of the host memory buffer.
+	 */
+	bdp = pinfo->rx_cur;
+	if (bdp->cbd_sc & BD_SC_EMPTY)
+		return NO_POLL_CHAR;
+
+	/* If the buffer address is in the CPM DPRAM, don't
+	 * convert it.
+	 */
+	cp = cpm2cpu_addr(bdp->cbd_bufaddr, pinfo);
+
+	if (obuf) {
+		i = c = bdp->cbd_datlen;
+		while (i-- > 0)
+			*obuf++ = *cp++;
+	} else
+		c = *cp;
+	bdp->cbd_sc &= ~(BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV | BD_SC_ID);
+	bdp->cbd_sc |= BD_SC_EMPTY;
+
+	if (bdp->cbd_sc & BD_SC_WRAP)
+		bdp = pinfo->rx_bd_base;
+	else
+		bdp++;
+	pinfo->rx_cur = (cbd_t *)bdp;
+
+	return (int)c;
+}
+
+static int cpm_get_poll_char(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+
+	if (!serial_polled) {
+		serial_polled = 1;
+		poll_chars = 0;
+	}
+	if (poll_chars <= 0) {
+		int ret = poll_wait_key(poll_buf, pinfo);
+
+		if (ret == NO_POLL_CHAR)
+			return ret;
+		poll_chars = ret;
+		pollp = poll_buf;
+	}
+	poll_chars--;
+	return *pollp++;
+}
+
+static void cpm_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	struct uart_cpm_port *pinfo =
+		container_of(port, struct uart_cpm_port, port);
+	static char ch[2];
+
+	ch[0] = (char)c;
+	cpm_uart_early_write(pinfo, ch, 1, false);
+}
+
+#ifdef CONFIG_SERIAL_CPM_CONSOLE
+static struct uart_port *udbg_port;
+
+static void udbg_cpm_putc(char c)
+{
+	if (c == '\n')
+		cpm_put_poll_char(udbg_port, '\r');
+	cpm_put_poll_char(udbg_port, c);
+}
+
+static int udbg_cpm_getc_poll(void)
+{
+	int c = cpm_get_poll_char(udbg_port);
+
+	return c == NO_POLL_CHAR ? -1 : c;
+}
+
+static int udbg_cpm_getc(void)
+{
+	int c;
+
+	while ((c = udbg_cpm_getc_poll()) == -1)
+		cpu_relax();
+	return c;
+}
+#endif /* CONFIG_SERIAL_CPM_CONSOLE */
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops cpm_uart_pops = {
+	.tx_empty	= cpm_uart_tx_empty,
+	.set_mctrl	= cpm_uart_set_mctrl,
+	.get_mctrl	= cpm_uart_get_mctrl,
+	.stop_tx	= cpm_uart_stop_tx,
+	.start_tx	= cpm_uart_start_tx,
+	.stop_rx	= cpm_uart_stop_rx,
+	.break_ctl	= cpm_uart_break_ctl,
+	.startup	= cpm_uart_startup,
+	.shutdown	= cpm_uart_shutdown,
+	.set_termios	= cpm_uart_set_termios,
+	.type		= cpm_uart_type,
+	.release_port	= cpm_uart_release_port,
+	.request_port	= cpm_uart_request_port,
+	.config_port	= cpm_uart_config_port,
+	.verify_port	= cpm_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = cpm_get_poll_char,
+	.poll_put_char = cpm_put_poll_char,
+#endif
+};
+
+static struct uart_cpm_port cpm_uart_ports[UART_NR];
+
+static void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
+				       struct device_node *np)
+{
+	void __iomem *pram;
+	unsigned long offset;
+	struct resource res;
+	resource_size_t len;
+
+	/* Don't remap parameter RAM if it has already been initialized
+	 * during console setup.
+	 */
+	if (IS_SMC(port) && port->smcup)
+		return port->smcup;
+	else if (!IS_SMC(port) && port->sccup)
+		return port->sccup;
+
+	if (of_address_to_resource(np, 1, &res))
+		return NULL;
+
+	len = resource_size(&res);
+	pram = ioremap(res.start, len);
+	if (!pram)
+		return NULL;
+
+	if (!IS_ENABLED(CONFIG_CPM2) || !IS_SMC(port))
+		return pram;
+
+	if (len != 2) {
+		pr_warn("cpm_uart[%d]: device tree references "
+			"SMC pram, using boot loader/wrapper pram mapping. "
+			"Please fix your device tree to reference the pram "
+			"base register instead.\n",
+			port->port.line);
+		return pram;
+	}
+
+	offset = cpm_muram_alloc(64, 64);
+	out_be16(pram, offset);
+	iounmap(pram);
+	return cpm_muram_addr(offset);
+}
+
+static void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
+{
+	if (!IS_ENABLED(CONFIG_CPM2) || !IS_SMC(port))
+		iounmap(pram);
+}
+
+static int cpm_uart_init_port(struct device_node *np,
+                              struct uart_cpm_port *pinfo)
+{
+	const u32 *data;
+	void __iomem *mem, *pram;
+	struct device *dev = pinfo->port.dev;
+	int len;
+	int ret;
+	int i;
+
+	data = of_get_property(np, "clock", NULL);
+	if (data) {
+		struct clk *clk = clk_get(NULL, (const char*)data);
+		if (!IS_ERR(clk))
+			pinfo->clk = clk;
+	}
+	if (!pinfo->clk) {
+		data = of_get_property(np, "fsl,cpm-brg", &len);
+		if (!data || len != 4) {
+			printk(KERN_ERR "CPM UART %pOFn has no/invalid "
+			                "fsl,cpm-brg property.\n", np);
+			return -EINVAL;
+		}
+		pinfo->brg = *data;
+	}
+
+	data = of_get_property(np, "fsl,cpm-command", &len);
+	if (!data || len != 4) {
+		printk(KERN_ERR "CPM UART %pOFn has no/invalid "
+		                "fsl,cpm-command property.\n", np);
+		return -EINVAL;
+	}
+	pinfo->command = *data;
+
+	mem = of_iomap(np, 0);
+	if (!mem)
+		return -ENOMEM;
+
+	if (of_device_is_compatible(np, "fsl,cpm1-scc-uart") ||
+	    of_device_is_compatible(np, "fsl,cpm2-scc-uart")) {
+		pinfo->sccp = mem;
+		pinfo->sccup = pram = cpm_uart_map_pram(pinfo, np);
+	} else if (of_device_is_compatible(np, "fsl,cpm1-smc-uart") ||
+	           of_device_is_compatible(np, "fsl,cpm2-smc-uart")) {
+		pinfo->flags |= FLAG_SMC;
+		pinfo->smcp = mem;
+		pinfo->smcup = pram = cpm_uart_map_pram(pinfo, np);
+	} else {
+		ret = -ENODEV;
+		goto out_mem;
+	}
+
+	if (!pram) {
+		ret = -ENOMEM;
+		goto out_mem;
+	}
+
+	pinfo->tx_nrfifos = TX_NUM_FIFO;
+	pinfo->tx_fifosize = TX_BUF_SIZE;
+	pinfo->rx_nrfifos = RX_NUM_FIFO;
+	pinfo->rx_fifosize = RX_BUF_SIZE;
+
+	pinfo->port.uartclk = ppc_proc_freq;
+	pinfo->port.mapbase = (unsigned long)mem;
+	pinfo->port.type = PORT_CPM;
+	pinfo->port.ops = &cpm_uart_pops;
+	pinfo->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_CPM_CONSOLE);
+	pinfo->port.iotype = UPIO_MEM;
+	pinfo->port.fifosize = pinfo->tx_nrfifos * pinfo->tx_fifosize;
+	spin_lock_init(&pinfo->port.lock);
+
+	for (i = 0; i < NUM_GPIOS; i++) {
+		struct gpio_desc *gpiod;
+
+		pinfo->gpios[i] = NULL;
+
+		gpiod = devm_gpiod_get_index_optional(dev, NULL, i, GPIOD_ASIS);
+
+		if (IS_ERR(gpiod)) {
+			ret = PTR_ERR(gpiod);
+			goto out_pram;
+		}
+
+		if (gpiod) {
+			if (i == GPIO_RTS || i == GPIO_DTR)
+				ret = gpiod_direction_output(gpiod, 0);
+			else
+				ret = gpiod_direction_input(gpiod);
+			if (ret) {
+				pr_err("can't set direction for gpio #%d: %d\n",
+					i, ret);
+				continue;
+			}
+			pinfo->gpios[i] = gpiod;
+		}
+	}
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_CPM
+#if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_CPM_CONSOLE)
+	if (!udbg_port)
+#endif
+		udbg_putc = NULL;
+#endif
+
+	return cpm_uart_request_port(&pinfo->port);
+
+out_pram:
+	cpm_uart_unmap_pram(pinfo, pram);
+out_mem:
+	iounmap(mem);
+	return ret;
+}
+
+#ifdef CONFIG_SERIAL_CPM_CONSOLE
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	Note that this is called with interrupts already disabled
+ */
+static void cpm_uart_console_write(struct console *co, const char *s,
+				   u_int count)
+{
+	struct uart_cpm_port *pinfo = &cpm_uart_ports[co->index];
+	unsigned long flags;
+
+	if (unlikely(oops_in_progress)) {
+		local_irq_save(flags);
+		cpm_uart_early_write(pinfo, s, count, true);
+		local_irq_restore(flags);
+	} else {
+		spin_lock_irqsave(&pinfo->port.lock, flags);
+		cpm_uart_early_write(pinfo, s, count, true);
+		spin_unlock_irqrestore(&pinfo->port.lock, flags);
+	}
+}
+
+
+static int __init cpm_uart_console_setup(struct console *co, char *options)
+{
+	int baud = 38400;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+	struct uart_cpm_port *pinfo;
+	struct uart_port *port;
+
+	struct device_node *np;
+	int i = 0;
+
+	if (co->index >= UART_NR) {
+		printk(KERN_ERR "cpm_uart: console index %d too high\n",
+		       co->index);
+		return -ENODEV;
+	}
+
+	for_each_node_by_type(np, "serial") {
+		if (!of_device_is_compatible(np, "fsl,cpm1-smc-uart") &&
+		    !of_device_is_compatible(np, "fsl,cpm1-scc-uart") &&
+		    !of_device_is_compatible(np, "fsl,cpm2-smc-uart") &&
+		    !of_device_is_compatible(np, "fsl,cpm2-scc-uart"))
+			continue;
+
+		if (i++ == co->index)
+			break;
+	}
+
+	if (!np)
+		return -ENODEV;
+
+	pinfo = &cpm_uart_ports[co->index];
+
+	pinfo->flags |= FLAG_CONSOLE;
+	port = &pinfo->port;
+
+	ret = cpm_uart_init_port(np, pinfo);
+	of_node_put(np);
+	if (ret)
+		return ret;
+
+	if (options) {
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	} else {
+		baud = get_baudrate();
+		if (baud == -1)
+			baud = 9600;
+	}
+
+	if (IS_SMC(pinfo)) {
+		out_be16(&pinfo->smcup->smc_brkcr, 0);
+		cpm_line_cr_cmd(pinfo, CPM_CR_STOP_TX);
+		clrbits8(&pinfo->smcp->smc_smcm, SMCM_RX | SMCM_TX);
+		clrbits16(&pinfo->smcp->smc_smcmr, SMCMR_REN | SMCMR_TEN);
+	} else {
+		out_be16(&pinfo->sccup->scc_brkcr, 0);
+		cpm_line_cr_cmd(pinfo, CPM_CR_GRA_STOP_TX);
+		clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_TX | UART_SCCM_RX);
+		clrbits32(&pinfo->sccp->scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
+	}
+
+	ret = cpm_uart_allocbuf(pinfo, 1);
+
+	if (ret)
+		return ret;
+
+	cpm_uart_initbd(pinfo);
+
+	if (IS_SMC(pinfo))
+		cpm_uart_init_smc(pinfo);
+	else
+		cpm_uart_init_scc(pinfo);
+
+	uart_set_options(port, co, baud, parity, bits, flow);
+	cpm_line_cr_cmd(pinfo, CPM_CR_RESTART_TX);
+
+#ifdef CONFIG_CONSOLE_POLL
+	if (!udbg_port) {
+		udbg_port = &pinfo->port;
+		udbg_putc = udbg_cpm_putc;
+		udbg_getc = udbg_cpm_getc;
+		udbg_getc_poll = udbg_cpm_getc_poll;
+	}
+#endif
+
+	return 0;
+}
+
+static struct uart_driver cpm_reg;
+static struct console cpm_scc_uart_console = {
+	.name		= "ttyCPM",
+	.write		= cpm_uart_console_write,
+	.device		= uart_console_device,
+	.setup		= cpm_uart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &cpm_reg,
+};
+
+static int __init cpm_uart_console_init(void)
+{
+	cpm_muram_init();
+	register_console(&cpm_scc_uart_console);
+	return 0;
+}
+
+console_initcall(cpm_uart_console_init);
+
+#define CPM_UART_CONSOLE	&cpm_scc_uart_console
+#else
+#define CPM_UART_CONSOLE	NULL
+#endif
+
+static struct uart_driver cpm_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "ttyCPM",
+	.dev_name	= "ttyCPM",
+	.major		= SERIAL_CPM_MAJOR,
+	.minor		= SERIAL_CPM_MINOR,
+	.cons		= CPM_UART_CONSOLE,
+	.nr		= UART_NR,
+};
+
+static int probe_index;
+
+static int cpm_uart_probe(struct platform_device *ofdev)
+{
+	int index = probe_index++;
+	struct uart_cpm_port *pinfo = &cpm_uart_ports[index];
+	int ret;
+
+	pinfo->port.line = index;
+
+	if (index >= UART_NR)
+		return -ENODEV;
+
+	platform_set_drvdata(ofdev, pinfo);
+
+	/* initialize the device pointer for the port */
+	pinfo->port.dev = &ofdev->dev;
+
+	pinfo->port.irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
+	if (!pinfo->port.irq)
+		return -EINVAL;
+
+	ret = cpm_uart_init_port(ofdev->dev.of_node, pinfo);
+	if (!ret)
+		return uart_add_one_port(&cpm_reg, &pinfo->port);
+
+	irq_dispose_mapping(pinfo->port.irq);
+
+	return ret;
+}
+
+static int cpm_uart_remove(struct platform_device *ofdev)
+{
+	struct uart_cpm_port *pinfo = platform_get_drvdata(ofdev);
+
+	uart_remove_one_port(&cpm_reg, &pinfo->port);
+
+	return 0;
+}
+
+static const struct of_device_id cpm_uart_match[] = {
+	{
+		.compatible = "fsl,cpm1-smc-uart",
+	},
+	{
+		.compatible = "fsl,cpm1-scc-uart",
+	},
+	{
+		.compatible = "fsl,cpm2-smc-uart",
+	},
+	{
+		.compatible = "fsl,cpm2-scc-uart",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, cpm_uart_match);
+
+static struct platform_driver cpm_uart_driver = {
+	.driver = {
+		.name = "cpm_uart",
+		.of_match_table = cpm_uart_match,
+	},
+	.probe = cpm_uart_probe,
+	.remove = cpm_uart_remove,
+ };
+
+static int __init cpm_uart_init(void)
+{
+	int ret = uart_register_driver(&cpm_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&cpm_uart_driver);
+	if (ret)
+		uart_unregister_driver(&cpm_reg);
+
+	return ret;
+}
+
+static void __exit cpm_uart_exit(void)
+{
+	platform_driver_unregister(&cpm_uart_driver);
+	uart_unregister_driver(&cpm_reg);
+}
+
+module_init(cpm_uart_init);
+module_exit(cpm_uart_exit);
+
+MODULE_AUTHOR("Kumar Gala/Antoniou Pantelis");
+MODULE_DESCRIPTION("CPM SCC/SMC port driver $Revision: 0.01 $");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV(SERIAL_CPM_MAJOR, SERIAL_CPM_MINOR);
diff --git a/drivers/tty/serial/cpm_uart.h b/drivers/tty/serial/cpm_uart.h
new file mode 100644
index 000000000..37bb6e976
--- /dev/null
+++ b/drivers/tty/serial/cpm_uart.h
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Driver for CPM (SCC/SMC) serial ports
+ *
+ *  Copyright (C) 2004 Freescale Semiconductor, Inc.
+ *
+ *  2006 (c) MontaVista Software, Inc.
+ *	Vitaly Bordug <vbordug@ru.mvista.com>
+ */
+#ifndef CPM_UART_H
+#define CPM_UART_H
+
+#include <linux/platform_device.h>
+
+struct gpio_desc;
+
+#if defined(CONFIG_CPM2)
+#include "asm/cpm2.h"
+#elif defined(CONFIG_CPM1)
+#include "asm/cpm1.h"
+#endif
+
+#define DPRAM_BASE	((u8 __iomem *)cpm_muram_addr(0))
+
+#define SERIAL_CPM_MAJOR	204
+#define SERIAL_CPM_MINOR	46
+
+#define IS_SMC(pinfo)		(pinfo->flags & FLAG_SMC)
+#define FLAG_SMC	0x00000002
+#define FLAG_CONSOLE	0x00000001
+
+#define UART_NR		6
+
+#define RX_NUM_FIFO	4
+#define RX_BUF_SIZE	32
+#define TX_NUM_FIFO	4
+#define TX_BUF_SIZE	32
+
+#define GPIO_CTS	0
+#define GPIO_RTS	1
+#define GPIO_DCD	2
+#define GPIO_DSR	3
+#define GPIO_DTR	4
+#define GPIO_RI		5
+
+#define NUM_GPIOS	(GPIO_RI+1)
+
+struct uart_cpm_port {
+	struct uart_port	port;
+	u16			rx_nrfifos;
+	u16			rx_fifosize;
+	u16			tx_nrfifos;
+	u16			tx_fifosize;
+	smc_t __iomem		*smcp;
+	smc_uart_t __iomem	*smcup;
+	scc_t __iomem		*sccp;
+	scc_uart_t __iomem	*sccup;
+	cbd_t __iomem		*rx_bd_base;
+	cbd_t __iomem		*rx_cur;
+	cbd_t __iomem		*tx_bd_base;
+	cbd_t __iomem		*tx_cur;
+	unsigned char		*tx_buf;
+	unsigned char		*rx_buf;
+	u32			flags;
+	struct clk		*clk;
+	u8			brg;
+	uint			 dp_addr;
+	void			*mem_addr;
+	dma_addr_t		 dma_addr;
+	u32			mem_size;
+	/* wait on close if needed */
+	int			wait_closing;
+	/* value to combine with opcode to form cpm command */
+	u32			command;
+	struct gpio_desc	*gpios[NUM_GPIOS];
+};
+
+/*
+   virtual to phys transtalion
+*/
+static inline unsigned long cpu2cpm_addr(void *addr,
+                                         struct uart_cpm_port *pinfo)
+{
+	int offset;
+	u32 val = (u32)addr;
+	u32 mem = (u32)pinfo->mem_addr;
+	/* sane check */
+	if (likely(val >= mem && val < mem + pinfo->mem_size)) {
+		offset = val - mem;
+		return pinfo->dma_addr + offset;
+	}
+	/* something nasty happened */
+	BUG();
+	return 0;
+}
+
+static inline void *cpm2cpu_addr(unsigned long addr,
+                                 struct uart_cpm_port *pinfo)
+{
+	int offset;
+	u32 val = addr;
+	u32 dma = (u32)pinfo->dma_addr;
+	/* sane check */
+	if (likely(val >= dma && val < dma + pinfo->mem_size)) {
+		offset = val - dma;
+		return pinfo->mem_addr + offset;
+	}
+	/* something nasty happened */
+	BUG();
+	return NULL;
+}
+
+
+#endif /* CPM_UART_H */
diff --git a/drivers/tty/serial/digicolor-usart.c b/drivers/tty/serial/digicolor-usart.c
new file mode 100644
index 000000000..128b5479e
--- /dev/null
+++ b/drivers/tty/serial/digicolor-usart.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for Conexant Digicolor serial ports (USART)
+ *
+ * Author: Baruch Siach <baruch@tkos.co.il>
+ *
+ * Copyright (C) 2014 Paradox Innovation Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+
+#define UA_ENABLE			0x00
+#define UA_ENABLE_ENABLE		BIT(0)
+
+#define UA_CONTROL			0x01
+#define UA_CONTROL_RX_ENABLE		BIT(0)
+#define UA_CONTROL_TX_ENABLE		BIT(1)
+#define UA_CONTROL_SOFT_RESET		BIT(2)
+
+#define UA_STATUS			0x02
+#define UA_STATUS_PARITY_ERR		BIT(0)
+#define UA_STATUS_FRAME_ERR		BIT(1)
+#define UA_STATUS_OVERRUN_ERR		BIT(2)
+#define UA_STATUS_TX_READY		BIT(6)
+
+#define UA_CONFIG			0x03
+#define UA_CONFIG_CHAR_LEN		BIT(0)
+#define UA_CONFIG_STOP_BITS		BIT(1)
+#define UA_CONFIG_PARITY		BIT(2)
+#define UA_CONFIG_ODD_PARITY		BIT(4)
+
+#define UA_EMI_REC			0x04
+
+#define UA_HBAUD_LO			0x08
+#define UA_HBAUD_HI			0x09
+
+#define UA_STATUS_FIFO			0x0a
+#define UA_STATUS_FIFO_RX_EMPTY		BIT(2)
+#define UA_STATUS_FIFO_RX_INT_ALMOST	BIT(3)
+#define UA_STATUS_FIFO_TX_FULL		BIT(4)
+#define UA_STATUS_FIFO_TX_INT_ALMOST	BIT(7)
+
+#define UA_CONFIG_FIFO			0x0b
+#define UA_CONFIG_FIFO_RX_THRESH	7
+#define UA_CONFIG_FIFO_RX_FIFO_MODE	BIT(3)
+#define UA_CONFIG_FIFO_TX_FIFO_MODE	BIT(7)
+
+#define UA_INTFLAG_CLEAR		0x1c
+#define UA_INTFLAG_SET			0x1d
+#define UA_INT_ENABLE			0x1e
+#define UA_INT_STATUS			0x1f
+
+#define UA_INT_TX			BIT(0)
+#define UA_INT_RX			BIT(1)
+
+#define DIGICOLOR_USART_NR		3
+
+/*
+ * We use the 16 bytes hardware FIFO to buffer Rx traffic. Rx interrupt is
+ * only produced when the FIFO is filled more than a certain configurable
+ * threshold. Unfortunately, there is no way to set this threshold below half
+ * FIFO. This means that we must periodically poll the FIFO status register to
+ * see whether there are waiting Rx bytes.
+ */
+
+struct digicolor_port {
+	struct uart_port port;
+	struct delayed_work rx_poll_work;
+};
+
+static struct uart_port *digicolor_ports[DIGICOLOR_USART_NR];
+
+static bool digicolor_uart_tx_full(struct uart_port *port)
+{
+	return !!(readb_relaxed(port->membase + UA_STATUS_FIFO) &
+		  UA_STATUS_FIFO_TX_FULL);
+}
+
+static bool digicolor_uart_rx_empty(struct uart_port *port)
+{
+	return !!(readb_relaxed(port->membase + UA_STATUS_FIFO) &
+		  UA_STATUS_FIFO_RX_EMPTY);
+}
+
+static void digicolor_uart_stop_tx(struct uart_port *port)
+{
+	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);
+
+	int_enable &= ~UA_INT_TX;
+	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
+}
+
+static void digicolor_uart_start_tx(struct uart_port *port)
+{
+	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);
+
+	int_enable |= UA_INT_TX;
+	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
+}
+
+static void digicolor_uart_stop_rx(struct uart_port *port)
+{
+	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);
+
+	int_enable &= ~UA_INT_RX;
+	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
+}
+
+static void digicolor_rx_poll(struct work_struct *work)
+{
+	struct digicolor_port *dp =
+		container_of(to_delayed_work(work),
+			     struct digicolor_port, rx_poll_work);
+
+	if (!digicolor_uart_rx_empty(&dp->port))
+		/* force RX interrupt */
+		writeb_relaxed(UA_INT_RX, dp->port.membase + UA_INTFLAG_SET);
+
+	schedule_delayed_work(&dp->rx_poll_work, msecs_to_jiffies(100));
+}
+
+static void digicolor_uart_rx(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (1) {
+		u8 status, ch, ch_flag;
+
+		if (digicolor_uart_rx_empty(port))
+			break;
+
+		ch = readb_relaxed(port->membase + UA_EMI_REC);
+		status = readb_relaxed(port->membase + UA_STATUS);
+
+		port->icount.rx++;
+		ch_flag = TTY_NORMAL;
+
+		if (status) {
+			if (status & UA_STATUS_PARITY_ERR)
+				port->icount.parity++;
+			else if (status & UA_STATUS_FRAME_ERR)
+				port->icount.frame++;
+			else if (status & UA_STATUS_OVERRUN_ERR)
+				port->icount.overrun++;
+
+			status &= port->read_status_mask;
+
+			if (status & UA_STATUS_PARITY_ERR)
+				ch_flag = TTY_PARITY;
+			else if (status & UA_STATUS_FRAME_ERR)
+				ch_flag = TTY_FRAME;
+			else if (status & UA_STATUS_OVERRUN_ERR)
+				ch_flag = TTY_OVERRUN;
+		}
+
+		if (status & port->ignore_status_mask)
+			continue;
+
+		uart_insert_char(port, status, UA_STATUS_OVERRUN_ERR, ch,
+				 ch_flag);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void digicolor_uart_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
+
+	if (digicolor_uart_tx_full(port))
+		return;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (port->x_char) {
+		writeb_relaxed(port->x_char, port->membase + UA_EMI_REC);
+		port->icount.tx++;
+		port->x_char = 0;
+		goto out;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		digicolor_uart_stop_tx(port);
+		goto out;
+	}
+
+	while (!uart_circ_empty(xmit)) {
+		writeb(xmit->buf[xmit->tail], port->membase + UA_EMI_REC);
+		uart_xmit_advance(port, 1);
+
+		if (digicolor_uart_tx_full(port))
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+out:
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static irqreturn_t digicolor_uart_int(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	u8 int_status = readb_relaxed(port->membase + UA_INT_STATUS);
+
+	writeb_relaxed(UA_INT_RX | UA_INT_TX,
+		       port->membase + UA_INTFLAG_CLEAR);
+
+	if (int_status & UA_INT_RX)
+		digicolor_uart_rx(port);
+	if (int_status & UA_INT_TX)
+		digicolor_uart_tx(port);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int digicolor_uart_tx_empty(struct uart_port *port)
+{
+	u8 status = readb_relaxed(port->membase + UA_STATUS);
+
+	return (status & UA_STATUS_TX_READY) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int digicolor_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS;
+}
+
+static void digicolor_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void digicolor_uart_break_ctl(struct uart_port *port, int state)
+{
+}
+
+static int digicolor_uart_startup(struct uart_port *port)
+{
+	struct digicolor_port *dp =
+		container_of(port, struct digicolor_port, port);
+
+	writeb_relaxed(UA_ENABLE_ENABLE, port->membase + UA_ENABLE);
+	writeb_relaxed(UA_CONTROL_SOFT_RESET, port->membase + UA_CONTROL);
+	writeb_relaxed(0, port->membase + UA_CONTROL);
+
+	writeb_relaxed(UA_CONFIG_FIFO_RX_FIFO_MODE
+		       | UA_CONFIG_FIFO_TX_FIFO_MODE | UA_CONFIG_FIFO_RX_THRESH,
+		       port->membase + UA_CONFIG_FIFO);
+	writeb_relaxed(UA_STATUS_FIFO_RX_INT_ALMOST,
+		       port->membase + UA_STATUS_FIFO);
+	writeb_relaxed(UA_CONTROL_RX_ENABLE | UA_CONTROL_TX_ENABLE,
+		       port->membase + UA_CONTROL);
+	writeb_relaxed(UA_INT_TX | UA_INT_RX,
+		       port->membase + UA_INT_ENABLE);
+
+	schedule_delayed_work(&dp->rx_poll_work, msecs_to_jiffies(100));
+
+	return 0;
+}
+
+static void digicolor_uart_shutdown(struct uart_port *port)
+{
+	struct digicolor_port *dp =
+		container_of(port, struct digicolor_port, port);
+
+	writeb_relaxed(0, port->membase + UA_ENABLE);
+	cancel_delayed_work_sync(&dp->rx_poll_work);
+}
+
+static void digicolor_uart_set_termios(struct uart_port *port,
+				       struct ktermios *termios,
+				       const struct ktermios *old)
+{
+	unsigned int baud, divisor;
+	u8 config = 0;
+	unsigned long flags;
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+	termios->c_iflag &= ~(BRKINT | IGNBRK);
+
+	/* Limit baud rates so that we don't need the fractional divider */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / (0x10000*16),
+				  port->uartclk / 256);
+	divisor = uart_get_divisor(port, baud) - 1;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS7:
+		break;
+	case CS8:
+	default:
+		config |= UA_CONFIG_CHAR_LEN;
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		config |= UA_CONFIG_STOP_BITS;
+
+	if (termios->c_cflag & PARENB) {
+		config |= UA_CONFIG_PARITY;
+		if (termios->c_cflag & PARODD)
+			config |= UA_CONFIG_ODD_PARITY;
+	}
+
+	/* Set read status mask */
+	port->read_status_mask = UA_STATUS_OVERRUN_ERR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UA_STATUS_PARITY_ERR
+			| UA_STATUS_FRAME_ERR;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= UA_STATUS_OVERRUN_ERR
+			| UA_STATUS_PARITY_ERR | UA_STATUS_FRAME_ERR;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	writeb_relaxed(config, port->membase + UA_CONFIG);
+	writeb_relaxed(divisor & 0xff, port->membase + UA_HBAUD_LO);
+	writeb_relaxed(divisor >> 8, port->membase + UA_HBAUD_HI);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *digicolor_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_DIGICOLOR) ? "DIGICOLOR USART" : NULL;
+}
+
+static void digicolor_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_DIGICOLOR;
+}
+
+static void digicolor_uart_release_port(struct uart_port *port)
+{
+}
+
+static int digicolor_uart_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static const struct uart_ops digicolor_uart_ops = {
+	.tx_empty	= digicolor_uart_tx_empty,
+	.set_mctrl	= digicolor_uart_set_mctrl,
+	.get_mctrl	= digicolor_uart_get_mctrl,
+	.stop_tx	= digicolor_uart_stop_tx,
+	.start_tx	= digicolor_uart_start_tx,
+	.stop_rx	= digicolor_uart_stop_rx,
+	.break_ctl	= digicolor_uart_break_ctl,
+	.startup	= digicolor_uart_startup,
+	.shutdown	= digicolor_uart_shutdown,
+	.set_termios	= digicolor_uart_set_termios,
+	.type		= digicolor_uart_type,
+	.config_port	= digicolor_uart_config_port,
+	.release_port	= digicolor_uart_release_port,
+	.request_port	= digicolor_uart_request_port,
+};
+
+static void digicolor_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (digicolor_uart_tx_full(port))
+		cpu_relax();
+
+	writeb_relaxed(ch, port->membase + UA_EMI_REC);
+}
+
+static void digicolor_uart_console_write(struct console *co, const char *c,
+					 unsigned n)
+{
+	struct uart_port *port = digicolor_ports[co->index];
+	u8 status;
+	unsigned long flags;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	uart_console_write(port, c, n, digicolor_uart_console_putchar);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Wait for transmitter to become empty */
+	do {
+		status = readb_relaxed(port->membase + UA_STATUS);
+	} while ((status & UA_STATUS_TX_READY) == 0);
+}
+
+static int digicolor_uart_console_setup(struct console *co, char *options)
+{
+	int baud = 115200, bits = 8, parity = 'n', flow = 'n';
+	struct uart_port *port;
+
+	if (co->index < 0 || co->index >= DIGICOLOR_USART_NR)
+		return -EINVAL;
+
+	port = digicolor_ports[co->index];
+	if (!port)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console digicolor_console = {
+	.name	= "ttyS",
+	.device	= uart_console_device,
+	.write	= digicolor_uart_console_write,
+	.setup	= digicolor_uart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+static struct uart_driver digicolor_uart = {
+	.driver_name	= "digicolor-usart",
+	.dev_name	= "ttyS",
+	.nr		= DIGICOLOR_USART_NR,
+};
+
+static int digicolor_uart_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int irq, ret, index;
+	struct digicolor_port *dp;
+	struct resource *res;
+	struct clk *uart_clk;
+
+	if (!np) {
+		dev_err(&pdev->dev, "Missing device tree node\n");
+		return -ENXIO;
+	}
+
+	index = of_alias_get_id(np, "serial");
+	if (index < 0 || index >= DIGICOLOR_USART_NR)
+		return -EINVAL;
+
+	dp = devm_kzalloc(&pdev->dev, sizeof(*dp), GFP_KERNEL);
+	if (!dp)
+		return -ENOMEM;
+
+	uart_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(uart_clk))
+		return PTR_ERR(uart_clk);
+
+	dp->port.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(dp->port.membase))
+		return PTR_ERR(dp->port.membase);
+	dp->port.mapbase = res->start;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	dp->port.irq = irq;
+
+	dp->port.iotype = UPIO_MEM;
+	dp->port.uartclk = clk_get_rate(uart_clk);
+	dp->port.fifosize = 16;
+	dp->port.dev = &pdev->dev;
+	dp->port.ops = &digicolor_uart_ops;
+	dp->port.line = index;
+	dp->port.type = PORT_DIGICOLOR;
+	spin_lock_init(&dp->port.lock);
+
+	digicolor_ports[index] = &dp->port;
+	platform_set_drvdata(pdev, &dp->port);
+
+	INIT_DELAYED_WORK(&dp->rx_poll_work, digicolor_rx_poll);
+
+	ret = devm_request_irq(&pdev->dev, dp->port.irq, digicolor_uart_int, 0,
+			       dev_name(&pdev->dev), &dp->port);
+	if (ret)
+		return ret;
+
+	return uart_add_one_port(&digicolor_uart, &dp->port);
+}
+
+static int digicolor_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&digicolor_uart, port);
+
+	return 0;
+}
+
+static const struct of_device_id digicolor_uart_dt_ids[] = {
+	{ .compatible = "cnxt,cx92755-usart", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, digicolor_uart_dt_ids);
+
+static struct platform_driver digicolor_uart_platform = {
+	.driver = {
+		.name		= "digicolor-usart",
+		.of_match_table	= of_match_ptr(digicolor_uart_dt_ids),
+	},
+	.probe	= digicolor_uart_probe,
+	.remove	= digicolor_uart_remove,
+};
+
+static int __init digicolor_uart_init(void)
+{
+	int ret;
+
+	if (IS_ENABLED(CONFIG_SERIAL_CONEXANT_DIGICOLOR_CONSOLE)) {
+		digicolor_uart.cons = &digicolor_console;
+		digicolor_console.data = &digicolor_uart;
+	}
+
+	ret = uart_register_driver(&digicolor_uart);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&digicolor_uart_platform);
+	if (ret)
+		uart_unregister_driver(&digicolor_uart);
+
+	return ret;
+}
+module_init(digicolor_uart_init);
+
+static void __exit digicolor_uart_exit(void)
+{
+	platform_driver_unregister(&digicolor_uart_platform);
+	uart_unregister_driver(&digicolor_uart);
+}
+module_exit(digicolor_uart_exit);
+
+MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
+MODULE_DESCRIPTION("Conexant Digicolor USART serial driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/dz.c b/drivers/tty/serial/dz.c
new file mode 100644
index 000000000..667f52e83
--- /dev/null
+++ b/drivers/tty/serial/dz.c
@@ -0,0 +1,947 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dz.c: Serial port driver for DECstations equipped
+ *       with the DZ chipset.
+ *
+ * Copyright (C) 1998 Olivier A. D. Lebaillif
+ *
+ * Email: olivier.lebaillif@ifrsys.com
+ *
+ * Copyright (C) 2004, 2006, 2007  Maciej W. Rozycki
+ *
+ * [31-AUG-98] triemer
+ * Changed IRQ to use Harald's dec internals interrupts.h
+ * removed base_addr code - moving address assignment to setup.c
+ * Changed name of dz_init to rs_init to be consistent with tc code
+ * [13-NOV-98] triemer fixed code to receive characters
+ *    after patches by harald to irq code.
+ * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
+ *            field from "current" - somewhere between 2.1.121 and 2.1.131
+ Qua Jun 27 15:02:26 BRT 2001
+ * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
+ *
+ * Parts (C) 1999 David Airlie, airlied@linux.ie
+ * [07-SEP-99] Bugfixes
+ *
+ * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
+ * Converted to new serial core
+ */
+
+#undef DEBUG_DZ
+
+#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#include <linux/atomic.h>
+#include <linux/io.h>
+#include <asm/bootinfo.h>
+
+#include <asm/dec/interrupts.h>
+#include <asm/dec/kn01.h>
+#include <asm/dec/kn02.h>
+#include <asm/dec/machtype.h>
+#include <asm/dec/prom.h>
+#include <asm/dec/system.h>
+
+#include "dz.h"
+
+
+MODULE_DESCRIPTION("DECstation DZ serial driver");
+MODULE_LICENSE("GPL");
+
+
+static char dz_name[] __initdata = "DECstation DZ serial driver version ";
+static char dz_version[] __initdata = "1.04";
+
+struct dz_port {
+	struct dz_mux		*mux;
+	struct uart_port	port;
+	unsigned int		cflag;
+};
+
+struct dz_mux {
+	struct dz_port		dport[DZ_NB_PORT];
+	atomic_t		map_guard;
+	atomic_t		irq_guard;
+	int			initialised;
+};
+
+static struct dz_mux dz_mux;
+
+static inline struct dz_port *to_dport(struct uart_port *uport)
+{
+	return container_of(uport, struct dz_port, port);
+}
+
+/*
+ * ------------------------------------------------------------
+ * dz_in () and dz_out ()
+ *
+ * These routines are used to access the registers of the DZ
+ * chip, hiding relocation differences between implementation.
+ * ------------------------------------------------------------
+ */
+
+static u16 dz_in(struct dz_port *dport, unsigned offset)
+{
+	void __iomem *addr = dport->port.membase + offset;
+
+	return readw(addr);
+}
+
+static void dz_out(struct dz_port *dport, unsigned offset, u16 value)
+{
+	void __iomem *addr = dport->port.membase + offset;
+
+	writew(value, addr);
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_stop () and rs_start ()
+ *
+ * These routines are called before setting or resetting
+ * tty->flow.stopped. They enable or disable transmitter interrupts,
+ * as necessary.
+ * ------------------------------------------------------------
+ */
+
+static void dz_stop_tx(struct uart_port *uport)
+{
+	struct dz_port *dport = to_dport(uport);
+	u16 tmp, mask = 1 << dport->port.line;
+
+	tmp = dz_in(dport, DZ_TCR);	/* read the TX flag */
+	tmp &= ~mask;			/* clear the TX flag */
+	dz_out(dport, DZ_TCR, tmp);
+}
+
+static void dz_start_tx(struct uart_port *uport)
+{
+	struct dz_port *dport = to_dport(uport);
+	u16 tmp, mask = 1 << dport->port.line;
+
+	tmp = dz_in(dport, DZ_TCR);	/* read the TX flag */
+	tmp |= mask;			/* set the TX flag */
+	dz_out(dport, DZ_TCR, tmp);
+}
+
+static void dz_stop_rx(struct uart_port *uport)
+{
+	struct dz_port *dport = to_dport(uport);
+
+	dport->cflag &= ~DZ_RXENAB;
+	dz_out(dport, DZ_LPR, dport->cflag);
+}
+
+/*
+ * ------------------------------------------------------------
+ *
+ * Here start the interrupt handling routines.  All of the following
+ * subroutines are declared as inline and are folded into
+ * dz_interrupt.  They were separated out for readability's sake.
+ *
+ * Note: dz_interrupt() is a "fast" interrupt, which means that it
+ * runs with interrupts turned off.  People who may want to modify
+ * dz_interrupt() should try to keep the interrupt handler as fast as
+ * possible.  After you are done making modifications, it is not a bad
+ * idea to do:
+ *
+ *	make drivers/serial/dz.s
+ *
+ * and look at the resulting assemble code in dz.s.
+ *
+ * ------------------------------------------------------------
+ */
+
+/*
+ * ------------------------------------------------------------
+ * receive_char ()
+ *
+ * This routine deals with inputs from any lines.
+ * ------------------------------------------------------------
+ */
+static inline void dz_receive_chars(struct dz_mux *mux)
+{
+	struct uart_port *uport;
+	struct dz_port *dport = &mux->dport[0];
+	struct uart_icount *icount;
+	int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
+	u16 status;
+	u8 ch, flag;
+	int i;
+
+	while ((status = dz_in(dport, DZ_RBUF)) & DZ_DVAL) {
+		dport = &mux->dport[LINE(status)];
+		uport = &dport->port;
+
+		ch = UCHAR(status);		/* grab the char */
+		flag = TTY_NORMAL;
+
+		icount = &uport->icount;
+		icount->rx++;
+
+		if (unlikely(status & (DZ_OERR | DZ_FERR | DZ_PERR))) {
+
+			/*
+			 * There is no separate BREAK status bit, so treat
+			 * null characters with framing errors as BREAKs;
+			 * normally, otherwise.  For this move the Framing
+			 * Error bit to a simulated BREAK bit.
+			 */
+			if (!ch) {
+				status |= (status & DZ_FERR) >>
+					  (ffs(DZ_FERR) - ffs(DZ_BREAK));
+				status &= ~DZ_FERR;
+			}
+
+			/* Handle SysRq/SAK & keep track of the statistics. */
+			if (status & DZ_BREAK) {
+				icount->brk++;
+				if (uart_handle_break(uport))
+					continue;
+			} else if (status & DZ_FERR)
+				icount->frame++;
+			else if (status & DZ_PERR)
+				icount->parity++;
+			if (status & DZ_OERR)
+				icount->overrun++;
+
+			status &= uport->read_status_mask;
+			if (status & DZ_BREAK)
+				flag = TTY_BREAK;
+			else if (status & DZ_FERR)
+				flag = TTY_FRAME;
+			else if (status & DZ_PERR)
+				flag = TTY_PARITY;
+
+		}
+
+		if (uart_handle_sysrq_char(uport, ch))
+			continue;
+
+		uart_insert_char(uport, status, DZ_OERR, ch, flag);
+		lines_rx[LINE(status)] = 1;
+	}
+	for (i = 0; i < DZ_NB_PORT; i++)
+		if (lines_rx[i])
+			tty_flip_buffer_push(&mux->dport[i].port.state->port);
+}
+
+/*
+ * ------------------------------------------------------------
+ * transmit_char ()
+ *
+ * This routine deals with outputs to any lines.
+ * ------------------------------------------------------------
+ */
+static inline void dz_transmit_chars(struct dz_mux *mux)
+{
+	struct dz_port *dport = &mux->dport[0];
+	struct circ_buf *xmit;
+	unsigned char tmp;
+	u16 status;
+
+	status = dz_in(dport, DZ_CSR);
+	dport = &mux->dport[LINE(status)];
+	xmit = &dport->port.state->xmit;
+
+	if (dport->port.x_char) {		/* XON/XOFF chars */
+		dz_out(dport, DZ_TDR, dport->port.x_char);
+		dport->port.icount.tx++;
+		dport->port.x_char = 0;
+		return;
+	}
+	/* If nothing to do or stopped or hardware stopped. */
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
+		spin_lock(&dport->port.lock);
+		dz_stop_tx(&dport->port);
+		spin_unlock(&dport->port.lock);
+		return;
+	}
+
+	/*
+	 * If something to do... (remember the dz has no output fifo,
+	 * so we go one char at a time) :-<
+	 */
+	tmp = xmit->buf[xmit->tail];
+	dz_out(dport, DZ_TDR, tmp);
+	uart_xmit_advance(&dport->port, 1);
+
+	if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
+		uart_write_wakeup(&dport->port);
+
+	/* Are we are done. */
+	if (uart_circ_empty(xmit)) {
+		spin_lock(&dport->port.lock);
+		dz_stop_tx(&dport->port);
+		spin_unlock(&dport->port.lock);
+	}
+}
+
+/*
+ * ------------------------------------------------------------
+ * check_modem_status()
+ *
+ * DS 3100 & 5100: Only valid for the MODEM line, duh!
+ * DS 5000/200: Valid for the MODEM and PRINTER line.
+ * ------------------------------------------------------------
+ */
+static inline void check_modem_status(struct dz_port *dport)
+{
+	/*
+	 * FIXME:
+	 * 1. No status change interrupt; use a timer.
+	 * 2. Handle the 3100/5000 as appropriate. --macro
+	 */
+	u16 status;
+
+	/* If not the modem line just return.  */
+	if (dport->port.line != DZ_MODEM)
+		return;
+
+	status = dz_in(dport, DZ_MSR);
+
+	/* it's easy, since DSR2 is the only bit in the register */
+	if (status)
+		dport->port.icount.dsr++;
+}
+
+/*
+ * ------------------------------------------------------------
+ * dz_interrupt ()
+ *
+ * this is the main interrupt routine for the DZ chip.
+ * It deals with the multiple ports.
+ * ------------------------------------------------------------
+ */
+static irqreturn_t dz_interrupt(int irq, void *dev_id)
+{
+	struct dz_mux *mux = dev_id;
+	struct dz_port *dport = &mux->dport[0];
+	u16 status;
+
+	/* get the reason why we just got an irq */
+	status = dz_in(dport, DZ_CSR);
+
+	if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
+		dz_receive_chars(mux);
+
+	if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
+		dz_transmit_chars(mux);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the DZ interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+static unsigned int dz_get_mctrl(struct uart_port *uport)
+{
+	/*
+	 * FIXME: Handle the 3100/5000 as appropriate. --macro
+	 */
+	struct dz_port *dport = to_dport(uport);
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+
+	if (dport->port.line == DZ_MODEM) {
+		if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
+			mctrl &= ~TIOCM_DSR;
+	}
+
+	return mctrl;
+}
+
+static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
+{
+	/*
+	 * FIXME: Handle the 3100/5000 as appropriate. --macro
+	 */
+	struct dz_port *dport = to_dport(uport);
+	u16 tmp;
+
+	if (dport->port.line == DZ_MODEM) {
+		tmp = dz_in(dport, DZ_TCR);
+		if (mctrl & TIOCM_DTR)
+			tmp &= ~DZ_MODEM_DTR;
+		else
+			tmp |= DZ_MODEM_DTR;
+		dz_out(dport, DZ_TCR, tmp);
+	}
+}
+
+/*
+ * -------------------------------------------------------------------
+ * startup ()
+ *
+ * various initialization tasks
+ * -------------------------------------------------------------------
+ */
+static int dz_startup(struct uart_port *uport)
+{
+	struct dz_port *dport = to_dport(uport);
+	struct dz_mux *mux = dport->mux;
+	unsigned long flags;
+	int irq_guard;
+	int ret;
+	u16 tmp;
+
+	irq_guard = atomic_add_return(1, &mux->irq_guard);
+	if (irq_guard != 1)
+		return 0;
+
+	ret = request_irq(dport->port.irq, dz_interrupt,
+			  IRQF_SHARED, "dz", mux);
+	if (ret) {
+		atomic_add(-1, &mux->irq_guard);
+		printk(KERN_ERR "dz: Cannot get IRQ %d!\n", dport->port.irq);
+		return ret;
+	}
+
+	spin_lock_irqsave(&dport->port.lock, flags);
+
+	/* Enable interrupts.  */
+	tmp = dz_in(dport, DZ_CSR);
+	tmp |= DZ_RIE | DZ_TIE;
+	dz_out(dport, DZ_CSR, tmp);
+
+	spin_unlock_irqrestore(&dport->port.lock, flags);
+
+	return 0;
+}
+
+/*
+ * -------------------------------------------------------------------
+ * shutdown ()
+ *
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.
+ * -------------------------------------------------------------------
+ */
+static void dz_shutdown(struct uart_port *uport)
+{
+	struct dz_port *dport = to_dport(uport);
+	struct dz_mux *mux = dport->mux;
+	unsigned long flags;
+	int irq_guard;
+	u16 tmp;
+
+	spin_lock_irqsave(&dport->port.lock, flags);
+	dz_stop_tx(&dport->port);
+	spin_unlock_irqrestore(&dport->port.lock, flags);
+
+	irq_guard = atomic_add_return(-1, &mux->irq_guard);
+	if (!irq_guard) {
+		/* Disable interrupts.  */
+		tmp = dz_in(dport, DZ_CSR);
+		tmp &= ~(DZ_RIE | DZ_TIE);
+		dz_out(dport, DZ_CSR, tmp);
+
+		free_irq(dport->port.irq, mux);
+	}
+}
+
+/*
+ * -------------------------------------------------------------------
+ * dz_tx_empty() -- get the transmitter empty status
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ *          is emptied.  On bus types like RS485, the transmitter must
+ *          release the bus after transmitting. This must be done when
+ *          the transmit shift register is empty, not be done when the
+ *          transmit holding register is empty.  This functionality
+ *          allows an RS485 driver to be written in user space.
+ * -------------------------------------------------------------------
+ */
+static unsigned int dz_tx_empty(struct uart_port *uport)
+{
+	struct dz_port *dport = to_dport(uport);
+	unsigned short tmp, mask = 1 << dport->port.line;
+
+	tmp = dz_in(dport, DZ_TCR);
+	tmp &= mask;
+
+	return tmp ? 0 : TIOCSER_TEMT;
+}
+
+static void dz_break_ctl(struct uart_port *uport, int break_state)
+{
+	/*
+	 * FIXME: Can't access BREAK bits in TDR easily;
+	 * reuse the code for polled TX. --macro
+	 */
+	struct dz_port *dport = to_dport(uport);
+	unsigned long flags;
+	unsigned short tmp, mask = 1 << dport->port.line;
+
+	spin_lock_irqsave(&uport->lock, flags);
+	tmp = dz_in(dport, DZ_TCR);
+	if (break_state)
+		tmp |= mask;
+	else
+		tmp &= ~mask;
+	dz_out(dport, DZ_TCR, tmp);
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+static int dz_encode_baud_rate(unsigned int baud)
+{
+	switch (baud) {
+	case 50:
+		return DZ_B50;
+	case 75:
+		return DZ_B75;
+	case 110:
+		return DZ_B110;
+	case 134:
+		return DZ_B134;
+	case 150:
+		return DZ_B150;
+	case 300:
+		return DZ_B300;
+	case 600:
+		return DZ_B600;
+	case 1200:
+		return DZ_B1200;
+	case 1800:
+		return DZ_B1800;
+	case 2000:
+		return DZ_B2000;
+	case 2400:
+		return DZ_B2400;
+	case 3600:
+		return DZ_B3600;
+	case 4800:
+		return DZ_B4800;
+	case 7200:
+		return DZ_B7200;
+	case 9600:
+		return DZ_B9600;
+	default:
+		return -1;
+	}
+}
+
+
+static void dz_reset(struct dz_port *dport)
+{
+	struct dz_mux *mux = dport->mux;
+
+	if (mux->initialised)
+		return;
+
+	dz_out(dport, DZ_CSR, DZ_CLR);
+	while (dz_in(dport, DZ_CSR) & DZ_CLR);
+	iob();
+
+	/* Enable scanning.  */
+	dz_out(dport, DZ_CSR, DZ_MSE);
+
+	mux->initialised = 1;
+}
+
+static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
+			   const struct ktermios *old_termios)
+{
+	struct dz_port *dport = to_dport(uport);
+	unsigned long flags;
+	unsigned int cflag, baud;
+	int bflag;
+
+	cflag = dport->port.line;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		cflag |= DZ_CS5;
+		break;
+	case CS6:
+		cflag |= DZ_CS6;
+		break;
+	case CS7:
+		cflag |= DZ_CS7;
+		break;
+	case CS8:
+	default:
+		cflag |= DZ_CS8;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		cflag |= DZ_CSTOPB;
+	if (termios->c_cflag & PARENB)
+		cflag |= DZ_PARENB;
+	if (termios->c_cflag & PARODD)
+		cflag |= DZ_PARODD;
+
+	baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
+	bflag = dz_encode_baud_rate(baud);
+	if (bflag < 0)	{
+		if (old_termios) {
+			/* Keep unchanged. */
+			baud = tty_termios_baud_rate(old_termios);
+			bflag = dz_encode_baud_rate(baud);
+		}
+		if (bflag < 0)	{		/* Resort to 9600.  */
+			baud = 9600;
+			bflag = DZ_B9600;
+		}
+		tty_termios_encode_baud_rate(termios, baud, baud);
+	}
+	cflag |= bflag;
+
+	if (termios->c_cflag & CREAD)
+		cflag |= DZ_RXENAB;
+
+	spin_lock_irqsave(&dport->port.lock, flags);
+
+	uart_update_timeout(uport, termios->c_cflag, baud);
+
+	dz_out(dport, DZ_LPR, cflag);
+	dport->cflag = cflag;
+
+	/* setup accept flag */
+	dport->port.read_status_mask = DZ_OERR;
+	if (termios->c_iflag & INPCK)
+		dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		dport->port.read_status_mask |= DZ_BREAK;
+
+	/* characters to ignore */
+	uport->ignore_status_mask = 0;
+	if ((termios->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
+		dport->port.ignore_status_mask |= DZ_OERR;
+	if (termios->c_iflag & IGNPAR)
+		dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
+	if (termios->c_iflag & IGNBRK)
+		dport->port.ignore_status_mask |= DZ_BREAK;
+
+	spin_unlock_irqrestore(&dport->port.lock, flags);
+}
+
+/*
+ * Hack alert!
+ * Required solely so that the initial PROM-based console
+ * works undisturbed in parallel with this one.
+ */
+static void dz_pm(struct uart_port *uport, unsigned int state,
+		  unsigned int oldstate)
+{
+	struct dz_port *dport = to_dport(uport);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dport->port.lock, flags);
+	if (state < 3)
+		dz_start_tx(&dport->port);
+	else
+		dz_stop_tx(&dport->port);
+	spin_unlock_irqrestore(&dport->port.lock, flags);
+}
+
+
+static const char *dz_type(struct uart_port *uport)
+{
+	return "DZ";
+}
+
+static void dz_release_port(struct uart_port *uport)
+{
+	struct dz_mux *mux = to_dport(uport)->mux;
+	int map_guard;
+
+	iounmap(uport->membase);
+	uport->membase = NULL;
+
+	map_guard = atomic_add_return(-1, &mux->map_guard);
+	if (!map_guard)
+		release_mem_region(uport->mapbase, dec_kn_slot_size);
+}
+
+static int dz_map_port(struct uart_port *uport)
+{
+	if (!uport->membase)
+		uport->membase = ioremap(uport->mapbase,
+						 dec_kn_slot_size);
+	if (!uport->membase) {
+		printk(KERN_ERR "dz: Cannot map MMIO\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static int dz_request_port(struct uart_port *uport)
+{
+	struct dz_mux *mux = to_dport(uport)->mux;
+	int map_guard;
+	int ret;
+
+	map_guard = atomic_add_return(1, &mux->map_guard);
+	if (map_guard == 1) {
+		if (!request_mem_region(uport->mapbase, dec_kn_slot_size,
+					"dz")) {
+			atomic_add(-1, &mux->map_guard);
+			printk(KERN_ERR
+			       "dz: Unable to reserve MMIO resource\n");
+			return -EBUSY;
+		}
+	}
+	ret = dz_map_port(uport);
+	if (ret) {
+		map_guard = atomic_add_return(-1, &mux->map_guard);
+		if (!map_guard)
+			release_mem_region(uport->mapbase, dec_kn_slot_size);
+		return ret;
+	}
+	return 0;
+}
+
+static void dz_config_port(struct uart_port *uport, int flags)
+{
+	struct dz_port *dport = to_dport(uport);
+
+	if (flags & UART_CONFIG_TYPE) {
+		if (dz_request_port(uport))
+			return;
+
+		uport->type = PORT_DZ;
+
+		dz_reset(dport);
+	}
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int dz_verify_port(struct uart_port *uport, struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
+		ret = -EINVAL;
+	if (ser->irq != uport->irq)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops dz_ops = {
+	.tx_empty	= dz_tx_empty,
+	.get_mctrl	= dz_get_mctrl,
+	.set_mctrl	= dz_set_mctrl,
+	.stop_tx	= dz_stop_tx,
+	.start_tx	= dz_start_tx,
+	.stop_rx	= dz_stop_rx,
+	.break_ctl	= dz_break_ctl,
+	.startup	= dz_startup,
+	.shutdown	= dz_shutdown,
+	.set_termios	= dz_set_termios,
+	.pm		= dz_pm,
+	.type		= dz_type,
+	.release_port	= dz_release_port,
+	.request_port	= dz_request_port,
+	.config_port	= dz_config_port,
+	.verify_port	= dz_verify_port,
+};
+
+static void __init dz_init_ports(void)
+{
+	static int first = 1;
+	unsigned long base;
+	int line;
+
+	if (!first)
+		return;
+	first = 0;
+
+	if (mips_machtype == MACH_DS23100 || mips_machtype == MACH_DS5100)
+		base = dec_kn_slot_base + KN01_DZ11;
+	else
+		base = dec_kn_slot_base + KN02_DZ11;
+
+	for (line = 0; line < DZ_NB_PORT; line++) {
+		struct dz_port *dport = &dz_mux.dport[line];
+		struct uart_port *uport = &dport->port;
+
+		dport->mux	= &dz_mux;
+
+		uport->irq	= dec_interrupt[DEC_IRQ_DZ11];
+		uport->fifosize	= 1;
+		uport->iotype	= UPIO_MEM;
+		uport->flags	= UPF_BOOT_AUTOCONF;
+		uport->ops	= &dz_ops;
+		uport->line	= line;
+		uport->mapbase	= base;
+		uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_DZ_CONSOLE);
+	}
+}
+
+#ifdef CONFIG_SERIAL_DZ_CONSOLE
+/*
+ * -------------------------------------------------------------------
+ * dz_console_putchar() -- transmit a character
+ *
+ * Polled transmission.  This is tricky.  We need to mask transmit
+ * interrupts so that they do not interfere, enable the transmitter
+ * for the line requested and then wait till the transmit scanner
+ * requests data for this line.  But it may request data for another
+ * line first, in which case we have to disable its transmitter and
+ * repeat waiting till our line pops up.  Only then the character may
+ * be transmitted.  Finally, the state of the transmitter mask is
+ * restored.  Welcome to the world of PDP-11!
+ * -------------------------------------------------------------------
+ */
+static void dz_console_putchar(struct uart_port *uport, unsigned char ch)
+{
+	struct dz_port *dport = to_dport(uport);
+	unsigned long flags;
+	unsigned short csr, tcr, trdy, mask;
+	int loops = 10000;
+
+	spin_lock_irqsave(&dport->port.lock, flags);
+	csr = dz_in(dport, DZ_CSR);
+	dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
+	tcr = dz_in(dport, DZ_TCR);
+	tcr |= 1 << dport->port.line;
+	mask = tcr;
+	dz_out(dport, DZ_TCR, mask);
+	iob();
+	spin_unlock_irqrestore(&dport->port.lock, flags);
+
+	do {
+		trdy = dz_in(dport, DZ_CSR);
+		if (!(trdy & DZ_TRDY))
+			continue;
+		trdy = (trdy & DZ_TLINE) >> 8;
+		if (trdy == dport->port.line)
+			break;
+		mask &= ~(1 << trdy);
+		dz_out(dport, DZ_TCR, mask);
+		iob();
+		udelay(2);
+	} while (--loops);
+
+	if (loops)				/* Cannot send otherwise. */
+		dz_out(dport, DZ_TDR, ch);
+
+	dz_out(dport, DZ_TCR, tcr);
+	dz_out(dport, DZ_CSR, csr);
+}
+
+/*
+ * -------------------------------------------------------------------
+ * dz_console_print ()
+ *
+ * dz_console_print is registered for printk.
+ * The console must be locked when we get here.
+ * -------------------------------------------------------------------
+ */
+static void dz_console_print(struct console *co,
+			     const char *str,
+			     unsigned int count)
+{
+	struct dz_port *dport = &dz_mux.dport[co->index];
+#ifdef DEBUG_DZ
+	prom_printf((char *) str);
+#endif
+	uart_console_write(&dport->port, str, count, dz_console_putchar);
+}
+
+static int __init dz_console_setup(struct console *co, char *options)
+{
+	struct dz_port *dport = &dz_mux.dport[co->index];
+	struct uart_port *uport = &dport->port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	ret = dz_map_port(uport);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&dport->port.lock);	/* For dz_pm().  */
+
+	dz_reset(dport);
+	dz_pm(uport, 0, -1);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&dport->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver dz_reg;
+static struct console dz_console = {
+	.name	= "ttyS",
+	.write	= dz_console_print,
+	.device	= uart_console_device,
+	.setup	= dz_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &dz_reg,
+};
+
+static int __init dz_serial_console_init(void)
+{
+	if (!IOASIC) {
+		dz_init_ports();
+		register_console(&dz_console);
+		return 0;
+	} else
+		return -ENXIO;
+}
+
+console_initcall(dz_serial_console_init);
+
+#define SERIAL_DZ_CONSOLE	&dz_console
+#else
+#define SERIAL_DZ_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_DZ_CONSOLE */
+
+static struct uart_driver dz_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "serial",
+	.dev_name		= "ttyS",
+	.major			= TTY_MAJOR,
+	.minor			= 64,
+	.nr			= DZ_NB_PORT,
+	.cons			= SERIAL_DZ_CONSOLE,
+};
+
+static int __init dz_init(void)
+{
+	int ret, i;
+
+	if (IOASIC)
+		return -ENXIO;
+
+	printk("%s%s\n", dz_name, dz_version);
+
+	dz_init_ports();
+
+	ret = uart_register_driver(&dz_reg);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < DZ_NB_PORT; i++)
+		uart_add_one_port(&dz_reg, &dz_mux.dport[i].port);
+
+	return 0;
+}
+
+module_init(dz_init);
diff --git a/drivers/tty/serial/dz.h b/drivers/tty/serial/dz.h
new file mode 100644
index 000000000..3b3e31954
--- /dev/null
+++ b/drivers/tty/serial/dz.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * dz.h: Serial port driver for DECstations equipped
+ *       with the DZ chipset.
+ *
+ * Copyright (C) 1998 Olivier A. D. Lebaillif 
+ *             
+ * Email: olivier.lebaillif@ifrsys.com
+ *
+ * Copyright (C) 2004, 2006  Maciej W. Rozycki
+ */
+#ifndef DZ_SERIAL_H
+#define DZ_SERIAL_H
+
+/*
+ * Definitions for the Control and Status Register.
+ */
+#define DZ_TRDY        0x8000                 /* Transmitter empty */
+#define DZ_TIE         0x4000                 /* Transmitter Interrupt Enbl */
+#define DZ_TLINE       0x0300                 /* Transmitter Line Number */
+#define DZ_RDONE       0x0080                 /* Receiver data ready */
+#define DZ_RIE         0x0040                 /* Receive Interrupt Enable */
+#define DZ_MSE         0x0020                 /* Master Scan Enable */
+#define DZ_CLR         0x0010                 /* Master reset */
+#define DZ_MAINT       0x0008                 /* Loop Back Mode */
+
+/*
+ * Definitions for the Receiver Buffer Register.
+ */
+#define DZ_RBUF_MASK   0x00FF                 /* Data Mask */
+#define DZ_LINE_MASK   0x0300                 /* Line Mask */
+#define DZ_DVAL        0x8000                 /* Valid Data indicator */
+#define DZ_OERR        0x4000                 /* Overrun error indicator */
+#define DZ_FERR        0x2000                 /* Frame error indicator */
+#define DZ_PERR        0x1000                 /* Parity error indicator */
+
+#define DZ_BREAK       0x0800                 /* BREAK event software flag */
+
+#define LINE(x) ((x & DZ_LINE_MASK) >> 8)     /* Get the line number
+                                                 from the input buffer */
+#define UCHAR(x) ((unsigned char)(x & DZ_RBUF_MASK))
+
+/*
+ * Definitions for the Transmit Control Register.
+ */
+#define DZ_LINE_KEYBOARD 0x0001
+#define DZ_LINE_MOUSE    0x0002
+#define DZ_LINE_MODEM    0x0004
+#define DZ_LINE_PRINTER  0x0008
+
+#define DZ_MODEM_RTS     0x0800               /* RTS for the modem line (2) */
+#define DZ_MODEM_DTR     0x0400               /* DTR for the modem line (2) */
+#define DZ_PRINT_RTS     0x0200               /* RTS for the prntr line (3) */
+#define DZ_PRINT_DTR     0x0100               /* DTR for the prntr line (3) */
+#define DZ_LNENB         0x000f               /* Transmitter Line Enable */
+
+/*
+ * Definitions for the Modem Status Register.
+ */
+#define DZ_MODEM_RI      0x0800               /* RI for the modem line (2) */
+#define DZ_MODEM_CD      0x0400               /* CD for the modem line (2) */
+#define DZ_MODEM_DSR     0x0200               /* DSR for the modem line (2) */
+#define DZ_MODEM_CTS     0x0100               /* CTS for the modem line (2) */
+#define DZ_PRINT_RI      0x0008               /* RI for the printer line (3) */
+#define DZ_PRINT_CD      0x0004               /* CD for the printer line (3) */
+#define DZ_PRINT_DSR     0x0002               /* DSR for the prntr line (3) */
+#define DZ_PRINT_CTS     0x0001               /* CTS for the prntr line (3) */
+
+/*
+ * Definitions for the Transmit Data Register.
+ */
+#define DZ_BRK0          0x0100               /* Break assertion for line 0 */
+#define DZ_BRK1          0x0200               /* Break assertion for line 1 */
+#define DZ_BRK2          0x0400               /* Break assertion for line 2 */
+#define DZ_BRK3          0x0800               /* Break assertion for line 3 */
+
+/*
+ * Definitions for the Line Parameter Register.
+ */
+#define DZ_KEYBOARD      0x0000               /* line 0 = keyboard */
+#define DZ_MOUSE         0x0001               /* line 1 = mouse */
+#define DZ_MODEM         0x0002               /* line 2 = modem */
+#define DZ_PRINTER       0x0003               /* line 3 = printer */
+
+#define DZ_CSIZE         0x0018               /* Number of bits per byte (mask) */
+#define DZ_CS5           0x0000               /* 5 bits per byte */
+#define DZ_CS6           0x0008               /* 6 bits per byte */
+#define DZ_CS7           0x0010               /* 7 bits per byte */
+#define DZ_CS8           0x0018               /* 8 bits per byte */
+
+#define DZ_CSTOPB        0x0020               /* 2 stop bits instead of one */ 
+
+#define DZ_PARENB        0x0040               /* Parity enable */
+#define DZ_PARODD        0x0080               /* Odd parity instead of even */
+
+#define DZ_CBAUD         0x0E00               /* Baud Rate (mask) */
+#define DZ_B50           0x0000
+#define DZ_B75           0x0100
+#define DZ_B110          0x0200
+#define DZ_B134          0x0300
+#define DZ_B150          0x0400
+#define DZ_B300          0x0500
+#define DZ_B600          0x0600
+#define DZ_B1200         0x0700 
+#define DZ_B1800         0x0800
+#define DZ_B2000         0x0900
+#define DZ_B2400         0x0A00
+#define DZ_B3600         0x0B00
+#define DZ_B4800         0x0C00
+#define DZ_B7200         0x0D00
+#define DZ_B9600         0x0E00
+
+#define DZ_RXENAB        0x1000               /* Receiver Enable */
+
+/*
+ * Addresses for the DZ registers
+ */
+#define DZ_CSR       0x00            /* Control and Status Register */
+#define DZ_RBUF      0x08            /* Receive Buffer */
+#define DZ_LPR       0x08            /* Line Parameters Register */
+#define DZ_TCR       0x10            /* Transmitter Control Register */
+#define DZ_MSR       0x18            /* Modem Status Register */
+#define DZ_TDR       0x18            /* Transmit Data Register */
+
+#define DZ_NB_PORT 4
+
+#define DZ_XMIT_SIZE   4096                 /* buffer size */
+#define DZ_WAKEUP_CHARS   DZ_XMIT_SIZE/4
+
+#endif /* DZ_SERIAL_H */
diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c b/drivers/tty/serial/earlycon-riscv-sbi.c
new file mode 100644
index 000000000..27afb0b74
--- /dev/null
+++ b/drivers/tty/serial/earlycon-riscv-sbi.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V SBI based earlycon
+ *
+ * Copyright (C) 2018 Anup Patel <anup@brainfault.org>
+ */
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <asm/sbi.h>
+
+static void sbi_putc(struct uart_port *port, unsigned char c)
+{
+	sbi_console_putchar(c);
+}
+
+static void sbi_console_write(struct console *con,
+			      const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+	uart_console_write(&dev->port, s, n, sbi_putc);
+}
+
+static int __init early_sbi_setup(struct earlycon_device *device,
+				  const char *opt)
+{
+	device->con->write = sbi_console_write;
+	return 0;
+}
+EARLYCON_DECLARE(sbi, early_sbi_setup);
diff --git a/drivers/tty/serial/earlycon-semihost.c b/drivers/tty/serial/earlycon-semihost.c
new file mode 100644
index 000000000..e4692a843
--- /dev/null
+++ b/drivers/tty/serial/earlycon-semihost.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * Adapted for ARM and earlycon:
+ * Copyright (C) 2014 Linaro Ltd.
+ * Author: Rob Herring <robh@kernel.org>
+ */
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <asm/semihost.h>
+
+static void smh_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+	uart_console_write(&dev->port, s, n, smh_putc);
+}
+
+static int
+__init early_smh_setup(struct earlycon_device *device, const char *opt)
+{
+	device->con->write = smh_write;
+	return 0;
+}
+EARLYCON_DECLARE(smh, early_smh_setup);
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
new file mode 100644
index 000000000..a5fbb6ed3
--- /dev/null
+++ b/drivers/tty/serial/earlycon.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ * Author: Rob Herring <robh@kernel.org>
+ *
+ * Based on 8250 earlycon:
+ * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <linux/sizes.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/acpi.h>
+
+#ifdef CONFIG_FIX_EARLYCON_MEM
+#include <asm/fixmap.h>
+#endif
+
+#include <asm/serial.h>
+
+static struct console early_con = {
+	.name =		"uart",		/* fixed up at earlycon registration */
+	.flags =	CON_PRINTBUFFER | CON_BOOT,
+	.index =	0,
+};
+
+static struct earlycon_device early_console_dev = {
+	.con = &early_con,
+};
+
+static void __iomem * __init earlycon_map(resource_size_t paddr, size_t size)
+{
+	void __iomem *base;
+#ifdef CONFIG_FIX_EARLYCON_MEM
+	set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK);
+	base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
+	base += paddr & ~PAGE_MASK;
+#else
+	base = ioremap(paddr, size);
+#endif
+	if (!base)
+		pr_err("%s: Couldn't map %pa\n", __func__, &paddr);
+
+	return base;
+}
+
+static void __init earlycon_init(struct earlycon_device *device,
+				 const char *name)
+{
+	struct console *earlycon = device->con;
+	const char *s;
+	size_t len;
+
+	/* scan backwards from end of string for first non-numeral */
+	for (s = name + strlen(name);
+	     s > name && s[-1] >= '0' && s[-1] <= '9';
+	     s--)
+		;
+	if (*s)
+		earlycon->index = simple_strtoul(s, NULL, 10);
+	len = s - name;
+	strscpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
+	earlycon->data = &early_console_dev;
+}
+
+static void __init earlycon_print_info(struct earlycon_device *device)
+{
+	struct console *earlycon = device->con;
+	struct uart_port *port = &device->port;
+
+	if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM16 ||
+	    port->iotype == UPIO_MEM32 || port->iotype == UPIO_MEM32BE)
+		pr_info("%s%d at MMIO%s %pa (options '%s')\n",
+			earlycon->name, earlycon->index,
+			(port->iotype == UPIO_MEM) ? "" :
+			(port->iotype == UPIO_MEM16) ? "16" :
+			(port->iotype == UPIO_MEM32) ? "32" : "32be",
+			&port->mapbase, device->options);
+	else
+		pr_info("%s%d at I/O port 0x%lx (options '%s')\n",
+			earlycon->name, earlycon->index,
+			port->iobase, device->options);
+}
+
+static int __init parse_options(struct earlycon_device *device, char *options)
+{
+	struct uart_port *port = &device->port;
+	int length;
+	resource_size_t addr;
+
+	if (uart_parse_earlycon(options, &port->iotype, &addr, &options))
+		return -EINVAL;
+
+	switch (port->iotype) {
+	case UPIO_MEM:
+		port->mapbase = addr;
+		break;
+	case UPIO_MEM16:
+		port->regshift = 1;
+		port->mapbase = addr;
+		break;
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+		port->regshift = 2;
+		port->mapbase = addr;
+		break;
+	case UPIO_PORT:
+		port->iobase = addr;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (options) {
+		char *uartclk;
+
+		device->baud = simple_strtoul(options, NULL, 0);
+		uartclk = strchr(options, ',');
+		if (uartclk && kstrtouint(uartclk + 1, 0, &port->uartclk) < 0)
+			pr_warn("[%s] unsupported earlycon uart clkrate option\n",
+				options);
+		length = min(strcspn(options, " ") + 1,
+			     (size_t)(sizeof(device->options)));
+		strscpy(device->options, options, length);
+	}
+
+	return 0;
+}
+
+static int __init register_earlycon(char *buf, const struct earlycon_id *match)
+{
+	int err;
+	struct uart_port *port = &early_console_dev.port;
+
+	/* On parsing error, pass the options buf to the setup function */
+	if (buf && !parse_options(&early_console_dev, buf))
+		buf = NULL;
+
+	spin_lock_init(&port->lock);
+	if (!port->uartclk)
+		port->uartclk = BASE_BAUD * 16;
+	if (port->mapbase)
+		port->membase = earlycon_map(port->mapbase, 64);
+
+	earlycon_init(&early_console_dev, match->name);
+	err = match->setup(&early_console_dev, buf);
+	earlycon_print_info(&early_console_dev);
+	if (err < 0)
+		return err;
+	if (!early_console_dev.con->write)
+		return -ENODEV;
+
+	register_console(early_console_dev.con);
+	return 0;
+}
+
+/**
+ *	setup_earlycon - match and register earlycon console
+ *	@buf:	earlycon param string
+ *
+ *	Registers the earlycon console matching the earlycon specified
+ *	in the param string @buf. Acceptable param strings are of the form
+ *	   <name>,io|mmio|mmio32|mmio32be,<addr>,<options>
+ *	   <name>,0x<addr>,<options>
+ *	   <name>,<options>
+ *	   <name>
+ *
+ *	Only for the third form does the earlycon setup() method receive the
+ *	<options> string in the 'options' parameter; all other forms set
+ *	the parameter to NULL.
+ *
+ *	Returns 0 if an attempt to register the earlycon was made,
+ *	otherwise negative error code
+ */
+int __init setup_earlycon(char *buf)
+{
+	const struct earlycon_id *match;
+	bool empty_compatible = true;
+
+	if (!buf || !buf[0])
+		return -EINVAL;
+
+	if (console_is_registered(&early_con))
+		return -EALREADY;
+
+again:
+	for (match = __earlycon_table; match < __earlycon_table_end; match++) {
+		size_t len = strlen(match->name);
+
+		if (strncmp(buf, match->name, len))
+			continue;
+
+		/* prefer entries with empty compatible */
+		if (empty_compatible && *match->compatible)
+			continue;
+
+		if (buf[len]) {
+			if (buf[len] != ',')
+				continue;
+			buf += len + 1;
+		} else
+			buf = NULL;
+
+		return register_earlycon(buf, match);
+	}
+
+	if (empty_compatible) {
+		empty_compatible = false;
+		goto again;
+	}
+
+	return -ENOENT;
+}
+
+/*
+ * This defers the initialization of the early console until after ACPI has
+ * been initialized.
+ */
+bool earlycon_acpi_spcr_enable __initdata;
+
+/* early_param wrapper for setup_earlycon() */
+static int __init param_setup_earlycon(char *buf)
+{
+	int err;
+
+	/* Just 'earlycon' is a valid param for devicetree and ACPI SPCR. */
+	if (!buf || !buf[0]) {
+		if (IS_ENABLED(CONFIG_ACPI_SPCR_TABLE)) {
+			earlycon_acpi_spcr_enable = true;
+			return 0;
+		} else if (!buf) {
+			return early_init_dt_scan_chosen_stdout();
+		}
+	}
+
+	err = setup_earlycon(buf);
+	if (err == -ENOENT || err == -EALREADY)
+		return 0;
+	return err;
+}
+early_param("earlycon", param_setup_earlycon);
+
+#ifdef CONFIG_OF_EARLY_FLATTREE
+
+int __init of_setup_earlycon(const struct earlycon_id *match,
+			     unsigned long node,
+			     const char *options)
+{
+	int err;
+	struct uart_port *port = &early_console_dev.port;
+	const __be32 *val;
+	bool big_endian;
+	u64 addr;
+
+	if (console_is_registered(&early_con))
+		return -EALREADY;
+
+	spin_lock_init(&port->lock);
+	port->iotype = UPIO_MEM;
+	addr = of_flat_dt_translate_address(node);
+	if (addr == OF_BAD_ADDR) {
+		pr_warn("[%s] bad address\n", match->name);
+		return -ENXIO;
+	}
+	port->mapbase = addr;
+
+	val = of_get_flat_dt_prop(node, "reg-offset", NULL);
+	if (val)
+		port->mapbase += be32_to_cpu(*val);
+	port->membase = earlycon_map(port->mapbase, SZ_4K);
+
+	val = of_get_flat_dt_prop(node, "reg-shift", NULL);
+	if (val)
+		port->regshift = be32_to_cpu(*val);
+	big_endian = of_get_flat_dt_prop(node, "big-endian", NULL) != NULL ||
+		(IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+		 of_get_flat_dt_prop(node, "native-endian", NULL) != NULL);
+	val = of_get_flat_dt_prop(node, "reg-io-width", NULL);
+	if (val) {
+		switch (be32_to_cpu(*val)) {
+		case 1:
+			port->iotype = UPIO_MEM;
+			break;
+		case 2:
+			port->iotype = UPIO_MEM16;
+			break;
+		case 4:
+			port->iotype = (big_endian) ? UPIO_MEM32BE : UPIO_MEM32;
+			break;
+		default:
+			pr_warn("[%s] unsupported reg-io-width\n", match->name);
+			return -EINVAL;
+		}
+	}
+
+	val = of_get_flat_dt_prop(node, "current-speed", NULL);
+	if (val)
+		early_console_dev.baud = be32_to_cpu(*val);
+
+	val = of_get_flat_dt_prop(node, "clock-frequency", NULL);
+	if (val)
+		port->uartclk = be32_to_cpu(*val);
+
+	if (options) {
+		early_console_dev.baud = simple_strtoul(options, NULL, 0);
+		strscpy(early_console_dev.options, options,
+			sizeof(early_console_dev.options));
+	}
+	earlycon_init(&early_console_dev, match->name);
+	err = match->setup(&early_console_dev, options);
+	earlycon_print_info(&early_console_dev);
+	if (err < 0)
+		return err;
+	if (!early_console_dev.con->write)
+		return -ENODEV;
+
+
+	register_console(early_console_dev.con);
+	return 0;
+}
+
+#endif /* CONFIG_OF_EARLY_FLATTREE */
diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
new file mode 100644
index 000000000..249cb380c
--- /dev/null
+++ b/drivers/tty/serial/fsl_linflexuart.c
@@ -0,0 +1,916 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Freescale LINFlexD UART serial port driver
+ *
+ * Copyright 2012-2016 Freescale Semiconductor, Inc.
+ * Copyright 2017-2019 NXP
+ */
+
+#include <linux/console.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+
+/* All registers are 32-bit width */
+
+#define LINCR1	0x0000	/* LIN control register				*/
+#define LINIER	0x0004	/* LIN interrupt enable register		*/
+#define LINSR	0x0008	/* LIN status register				*/
+#define LINESR	0x000C	/* LIN error status register			*/
+#define UARTCR	0x0010	/* UART mode control register			*/
+#define UARTSR	0x0014	/* UART mode status register			*/
+#define LINTCSR	0x0018	/* LIN timeout control status register		*/
+#define LINOCR	0x001C	/* LIN output compare register			*/
+#define LINTOCR	0x0020	/* LIN timeout control register			*/
+#define LINFBRR	0x0024	/* LIN fractional baud rate register		*/
+#define LINIBRR	0x0028	/* LIN integer baud rate register		*/
+#define LINCFR	0x002C	/* LIN checksum field register			*/
+#define LINCR2	0x0030	/* LIN control register 2			*/
+#define BIDR	0x0034	/* Buffer identifier register			*/
+#define BDRL	0x0038	/* Buffer data register least significant	*/
+#define BDRM	0x003C	/* Buffer data register most significant	*/
+#define IFER	0x0040	/* Identifier filter enable register		*/
+#define IFMI	0x0044	/* Identifier filter match index		*/
+#define IFMR	0x0048	/* Identifier filter mode register		*/
+#define GCR	0x004C	/* Global control register			*/
+#define UARTPTO	0x0050	/* UART preset timeout register			*/
+#define UARTCTO	0x0054	/* UART current timeout register		*/
+
+/*
+ * Register field definitions
+ */
+
+#define LINFLEXD_LINCR1_INIT		BIT(0)
+#define LINFLEXD_LINCR1_MME		BIT(4)
+#define LINFLEXD_LINCR1_BF		BIT(7)
+
+#define LINFLEXD_LINSR_LINS_INITMODE	BIT(12)
+#define LINFLEXD_LINSR_LINS_MASK	(0xF << 12)
+
+#define LINFLEXD_LINIER_SZIE		BIT(15)
+#define LINFLEXD_LINIER_OCIE		BIT(14)
+#define LINFLEXD_LINIER_BEIE		BIT(13)
+#define LINFLEXD_LINIER_CEIE		BIT(12)
+#define LINFLEXD_LINIER_HEIE		BIT(11)
+#define LINFLEXD_LINIER_FEIE		BIT(8)
+#define LINFLEXD_LINIER_BOIE		BIT(7)
+#define LINFLEXD_LINIER_LSIE		BIT(6)
+#define LINFLEXD_LINIER_WUIE		BIT(5)
+#define LINFLEXD_LINIER_DBFIE		BIT(4)
+#define LINFLEXD_LINIER_DBEIETOIE	BIT(3)
+#define LINFLEXD_LINIER_DRIE		BIT(2)
+#define LINFLEXD_LINIER_DTIE		BIT(1)
+#define LINFLEXD_LINIER_HRIE		BIT(0)
+
+#define LINFLEXD_UARTCR_OSR_MASK	(0xF << 24)
+#define LINFLEXD_UARTCR_OSR(uartcr)	(((uartcr) \
+					& LINFLEXD_UARTCR_OSR_MASK) >> 24)
+
+#define LINFLEXD_UARTCR_ROSE		BIT(23)
+
+#define LINFLEXD_UARTCR_RFBM		BIT(9)
+#define LINFLEXD_UARTCR_TFBM		BIT(8)
+#define LINFLEXD_UARTCR_WL1		BIT(7)
+#define LINFLEXD_UARTCR_PC1		BIT(6)
+
+#define LINFLEXD_UARTCR_RXEN		BIT(5)
+#define LINFLEXD_UARTCR_TXEN		BIT(4)
+#define LINFLEXD_UARTCR_PC0		BIT(3)
+
+#define LINFLEXD_UARTCR_PCE		BIT(2)
+#define LINFLEXD_UARTCR_WL0		BIT(1)
+#define LINFLEXD_UARTCR_UART		BIT(0)
+
+#define LINFLEXD_UARTSR_SZF		BIT(15)
+#define LINFLEXD_UARTSR_OCF		BIT(14)
+#define LINFLEXD_UARTSR_PE3		BIT(13)
+#define LINFLEXD_UARTSR_PE2		BIT(12)
+#define LINFLEXD_UARTSR_PE1		BIT(11)
+#define LINFLEXD_UARTSR_PE0		BIT(10)
+#define LINFLEXD_UARTSR_RMB		BIT(9)
+#define LINFLEXD_UARTSR_FEF		BIT(8)
+#define LINFLEXD_UARTSR_BOF		BIT(7)
+#define LINFLEXD_UARTSR_RPS		BIT(6)
+#define LINFLEXD_UARTSR_WUF		BIT(5)
+#define LINFLEXD_UARTSR_4		BIT(4)
+
+#define LINFLEXD_UARTSR_TO		BIT(3)
+
+#define LINFLEXD_UARTSR_DRFRFE		BIT(2)
+#define LINFLEXD_UARTSR_DTFTFF		BIT(1)
+#define LINFLEXD_UARTSR_NF		BIT(0)
+#define LINFLEXD_UARTSR_PE		(LINFLEXD_UARTSR_PE0 |\
+					 LINFLEXD_UARTSR_PE1 |\
+					 LINFLEXD_UARTSR_PE2 |\
+					 LINFLEXD_UARTSR_PE3)
+
+#define LINFLEX_LDIV_MULTIPLIER		(16)
+
+#define DRIVER_NAME	"fsl-linflexuart"
+#define DEV_NAME	"ttyLF"
+#define UART_NR		4
+
+#define EARLYCON_BUFFER_INITIAL_CAP	8
+
+#define PREINIT_DELAY			2000 /* us */
+
+static const struct of_device_id linflex_dt_ids[] = {
+	{
+		.compatible = "fsl,s32v234-linflexuart",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, linflex_dt_ids);
+
+#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
+static struct uart_port *earlycon_port;
+static bool linflex_earlycon_same_instance;
+static DEFINE_SPINLOCK(init_lock);
+static bool during_init;
+
+static struct {
+	char *content;
+	unsigned int len, cap;
+} earlycon_buf;
+#endif
+
+static void linflex_stop_tx(struct uart_port *port)
+{
+	unsigned long ier;
+
+	ier = readl(port->membase + LINIER);
+	ier &= ~(LINFLEXD_LINIER_DTIE);
+	writel(ier, port->membase + LINIER);
+}
+
+static void linflex_stop_rx(struct uart_port *port)
+{
+	unsigned long ier;
+
+	ier = readl(port->membase + LINIER);
+	writel(ier & ~LINFLEXD_LINIER_DRIE, port->membase + LINIER);
+}
+
+static void linflex_put_char(struct uart_port *sport, unsigned char c)
+{
+	unsigned long status;
+
+	writeb(c, sport->membase + BDRL);
+
+	/* Waiting for data transmission completed. */
+	while (((status = readl(sport->membase + UARTSR)) &
+				LINFLEXD_UARTSR_DTFTFF) !=
+				LINFLEXD_UARTSR_DTFTFF)
+		;
+
+	writel(status | LINFLEXD_UARTSR_DTFTFF, sport->membase + UARTSR);
+}
+
+static inline void linflex_transmit_buffer(struct uart_port *sport)
+{
+	struct circ_buf *xmit = &sport->state->xmit;
+
+	while (!uart_circ_empty(xmit)) {
+		linflex_put_char(sport, xmit->buf[xmit->tail]);
+		uart_xmit_advance(sport, 1);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(sport);
+
+	if (uart_circ_empty(xmit))
+		linflex_stop_tx(sport);
+}
+
+static void linflex_start_tx(struct uart_port *port)
+{
+	unsigned long ier;
+
+	linflex_transmit_buffer(port);
+	ier = readl(port->membase + LINIER);
+	writel(ier | LINFLEXD_LINIER_DTIE, port->membase + LINIER);
+}
+
+static irqreturn_t linflex_txint(int irq, void *dev_id)
+{
+	struct uart_port *sport = dev_id;
+	struct circ_buf *xmit = &sport->state->xmit;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->lock, flags);
+
+	if (sport->x_char) {
+		linflex_put_char(sport, sport->x_char);
+		goto out;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(sport)) {
+		linflex_stop_tx(sport);
+		goto out;
+	}
+
+	linflex_transmit_buffer(sport);
+out:
+	spin_unlock_irqrestore(&sport->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t linflex_rxint(int irq, void *dev_id)
+{
+	struct uart_port *sport = dev_id;
+	unsigned int flg;
+	struct tty_port *port = &sport->state->port;
+	unsigned long flags, status;
+	unsigned char rx;
+	bool brk;
+
+	spin_lock_irqsave(&sport->lock, flags);
+
+	status = readl(sport->membase + UARTSR);
+	while (status & LINFLEXD_UARTSR_RMB) {
+		rx = readb(sport->membase + BDRM);
+		brk = false;
+		flg = TTY_NORMAL;
+		sport->icount.rx++;
+
+		if (status & (LINFLEXD_UARTSR_BOF | LINFLEXD_UARTSR_FEF |
+				LINFLEXD_UARTSR_PE)) {
+			if (status & LINFLEXD_UARTSR_BOF)
+				sport->icount.overrun++;
+			if (status & LINFLEXD_UARTSR_FEF) {
+				if (!rx) {
+					brk = true;
+					sport->icount.brk++;
+				} else
+					sport->icount.frame++;
+			}
+			if (status & LINFLEXD_UARTSR_PE)
+				sport->icount.parity++;
+		}
+
+		writel(status, sport->membase + UARTSR);
+		status = readl(sport->membase + UARTSR);
+
+		if (brk) {
+			uart_handle_break(sport);
+		} else {
+			if (uart_handle_sysrq_char(sport, (unsigned char)rx))
+				continue;
+			tty_insert_flip_char(port, rx, flg);
+		}
+	}
+
+	spin_unlock_irqrestore(&sport->lock, flags);
+
+	tty_flip_buffer_push(port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t linflex_int(int irq, void *dev_id)
+{
+	struct uart_port *sport = dev_id;
+	unsigned long status;
+
+	status = readl(sport->membase + UARTSR);
+
+	if (status & LINFLEXD_UARTSR_DRFRFE)
+		linflex_rxint(irq, dev_id);
+	if (status & LINFLEXD_UARTSR_DTFTFF)
+		linflex_txint(irq, dev_id);
+
+	return IRQ_HANDLED;
+}
+
+/* return TIOCSER_TEMT when transmitter is not busy */
+static unsigned int linflex_tx_empty(struct uart_port *port)
+{
+	unsigned long status;
+
+	status = readl(port->membase + UARTSR) & LINFLEXD_UARTSR_DTFTFF;
+
+	return status ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int linflex_get_mctrl(struct uart_port *port)
+{
+	return 0;
+}
+
+static void linflex_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void linflex_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static void linflex_setup_watermark(struct uart_port *sport)
+{
+	unsigned long cr, ier, cr1;
+
+	/* Disable transmission/reception */
+	ier = readl(sport->membase + LINIER);
+	ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
+	writel(ier, sport->membase + LINIER);
+
+	cr = readl(sport->membase + UARTCR);
+	cr &= ~(LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN);
+	writel(cr, sport->membase + UARTCR);
+
+	/* Enter initialization mode by setting INIT bit */
+
+	/* set the Linflex in master mode and activate by-pass filter */
+	cr1 = LINFLEXD_LINCR1_BF | LINFLEXD_LINCR1_MME
+	      | LINFLEXD_LINCR1_INIT;
+	writel(cr1, sport->membase + LINCR1);
+
+	/* wait for init mode entry */
+	while ((readl(sport->membase + LINSR)
+		& LINFLEXD_LINSR_LINS_MASK)
+		!= LINFLEXD_LINSR_LINS_INITMODE)
+		;
+
+	/*
+	 *	UART = 0x1;		- Linflex working in UART mode
+	 *	TXEN = 0x1;		- Enable transmission of data now
+	 *	RXEn = 0x1;		- Receiver enabled
+	 *	WL0 = 0x1;		- 8 bit data
+	 *	PCE = 0x0;		- No parity
+	 */
+
+	/* set UART bit to allow writing other bits */
+	writel(LINFLEXD_UARTCR_UART, sport->membase + UARTCR);
+
+	cr = (LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN |
+	      LINFLEXD_UARTCR_WL0 | LINFLEXD_UARTCR_UART);
+
+	writel(cr, sport->membase + UARTCR);
+
+	cr1 &= ~(LINFLEXD_LINCR1_INIT);
+
+	writel(cr1, sport->membase + LINCR1);
+
+	ier = readl(sport->membase + LINIER);
+	ier |= LINFLEXD_LINIER_DRIE;
+	ier |= LINFLEXD_LINIER_DTIE;
+
+	writel(ier, sport->membase + LINIER);
+}
+
+static int linflex_startup(struct uart_port *port)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	linflex_setup_watermark(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	ret = devm_request_irq(port->dev, port->irq, linflex_int, 0,
+			       DRIVER_NAME, port);
+
+	return ret;
+}
+
+static void linflex_shutdown(struct uart_port *port)
+{
+	unsigned long ier;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* disable interrupts */
+	ier = readl(port->membase + LINIER);
+	ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
+	writel(ier, port->membase + LINIER);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	devm_free_irq(port->dev, port->irq, port);
+}
+
+static void
+linflex_set_termios(struct uart_port *port, struct ktermios *termios,
+		    const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned long cr, old_cr, cr1;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+
+	cr = readl(port->membase + UARTCR);
+	old_cr = cr;
+
+	/* Enter initialization mode by setting INIT bit */
+	cr1 = readl(port->membase + LINCR1);
+	cr1 |= LINFLEXD_LINCR1_INIT;
+	writel(cr1, port->membase + LINCR1);
+
+	/* wait for init mode entry */
+	while ((readl(port->membase + LINSR)
+		& LINFLEXD_LINSR_LINS_MASK)
+		!= LINFLEXD_LINSR_LINS_INITMODE)
+		;
+
+	/*
+	 * only support CS8 and CS7, and for CS7 must enable PE.
+	 * supported mode:
+	 *	- (7,e/o,1)
+	 *	- (8,n,1)
+	 *	- (8,e/o,1)
+	 */
+	/* enter the UART into configuration mode */
+
+	while ((termios->c_cflag & CSIZE) != CS8 &&
+	       (termios->c_cflag & CSIZE) != CS7) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS7) {
+		/* Word length: WL1WL0:00 */
+		cr = old_cr & ~LINFLEXD_UARTCR_WL1 & ~LINFLEXD_UARTCR_WL0;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS8) {
+		/* Word length: WL1WL0:01 */
+		cr = (old_cr | LINFLEXD_UARTCR_WL0) & ~LINFLEXD_UARTCR_WL1;
+	}
+
+	if (termios->c_cflag & CMSPAR) {
+		if ((termios->c_cflag & CSIZE) != CS8) {
+			termios->c_cflag &= ~CSIZE;
+			termios->c_cflag |= CS8;
+		}
+		/* has a space/sticky bit */
+		cr |= LINFLEXD_UARTCR_WL0;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		termios->c_cflag &= ~CSTOPB;
+
+	/* parity must be enabled when CS7 to match 8-bits format */
+	if ((termios->c_cflag & CSIZE) == CS7)
+		termios->c_cflag |= PARENB;
+
+	if ((termios->c_cflag & PARENB)) {
+		cr |= LINFLEXD_UARTCR_PCE;
+		if (termios->c_cflag & PARODD)
+			cr = (cr | LINFLEXD_UARTCR_PC0) &
+			     (~LINFLEXD_UARTCR_PC1);
+		else
+			cr = cr & (~LINFLEXD_UARTCR_PC1 &
+				   ~LINFLEXD_UARTCR_PC0);
+	} else {
+		cr &= ~LINFLEXD_UARTCR_PCE;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	port->read_status_mask = 0;
+
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |=	(LINFLEXD_UARTSR_FEF |
+						 LINFLEXD_UARTSR_PE0 |
+						 LINFLEXD_UARTSR_PE1 |
+						 LINFLEXD_UARTSR_PE2 |
+						 LINFLEXD_UARTSR_PE3);
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= LINFLEXD_UARTSR_FEF;
+
+	/* characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
+		/*
+		 * if we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= LINFLEXD_UARTSR_BOF;
+	}
+
+	writel(cr, port->membase + UARTCR);
+
+	cr1 &= ~(LINFLEXD_LINCR1_INIT);
+
+	writel(cr1, port->membase + LINCR1);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *linflex_type(struct uart_port *port)
+{
+	return "FSL_LINFLEX";
+}
+
+static void linflex_release_port(struct uart_port *port)
+{
+	/* nothing to do */
+}
+
+static int linflex_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/* configure/auto-configure the port */
+static void linflex_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_LINFLEXUART;
+}
+
+static const struct uart_ops linflex_pops = {
+	.tx_empty	= linflex_tx_empty,
+	.set_mctrl	= linflex_set_mctrl,
+	.get_mctrl	= linflex_get_mctrl,
+	.stop_tx	= linflex_stop_tx,
+	.start_tx	= linflex_start_tx,
+	.stop_rx	= linflex_stop_rx,
+	.break_ctl	= linflex_break_ctl,
+	.startup	= linflex_startup,
+	.shutdown	= linflex_shutdown,
+	.set_termios	= linflex_set_termios,
+	.type		= linflex_type,
+	.request_port	= linflex_request_port,
+	.release_port	= linflex_release_port,
+	.config_port	= linflex_config_port,
+};
+
+static struct uart_port *linflex_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
+static void linflex_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned long cr;
+
+	cr = readl(port->membase + UARTCR);
+
+	writeb(ch, port->membase + BDRL);
+
+	if (!(cr & LINFLEXD_UARTCR_TFBM))
+		while ((readl(port->membase + UARTSR) &
+					LINFLEXD_UARTSR_DTFTFF)
+				!= LINFLEXD_UARTSR_DTFTFF)
+			;
+	else
+		while (readl(port->membase + UARTSR) &
+					LINFLEXD_UARTSR_DTFTFF)
+			;
+
+	if (!(cr & LINFLEXD_UARTCR_TFBM)) {
+		writel((readl(port->membase + UARTSR) |
+					LINFLEXD_UARTSR_DTFTFF),
+					port->membase + UARTSR);
+	}
+}
+
+static void linflex_earlycon_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned long flags;
+	char *ret;
+
+	if (!linflex_earlycon_same_instance) {
+		linflex_console_putchar(port, ch);
+		return;
+	}
+
+	spin_lock_irqsave(&init_lock, flags);
+	if (!during_init)
+		goto outside_init;
+
+	if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT)
+		goto init_release;
+
+	if (!earlycon_buf.cap) {
+		earlycon_buf.content = kmalloc(EARLYCON_BUFFER_INITIAL_CAP,
+					       GFP_ATOMIC);
+		earlycon_buf.cap = earlycon_buf.content ?
+				   EARLYCON_BUFFER_INITIAL_CAP : 0;
+	} else if (earlycon_buf.len == earlycon_buf.cap) {
+		ret = krealloc(earlycon_buf.content, earlycon_buf.cap << 1,
+			       GFP_ATOMIC);
+		if (ret) {
+			earlycon_buf.content = ret;
+			earlycon_buf.cap <<= 1;
+		}
+	}
+
+	if (earlycon_buf.len < earlycon_buf.cap)
+		earlycon_buf.content[earlycon_buf.len++] = ch;
+
+	goto init_release;
+
+outside_init:
+	linflex_console_putchar(port, ch);
+init_release:
+	spin_unlock_irqrestore(&init_lock, flags);
+}
+
+static void linflex_string_write(struct uart_port *sport, const char *s,
+				 unsigned int count)
+{
+	unsigned long cr, ier = 0;
+
+	ier = readl(sport->membase + LINIER);
+	linflex_stop_tx(sport);
+
+	cr = readl(sport->membase + UARTCR);
+	cr |= (LINFLEXD_UARTCR_TXEN);
+	writel(cr, sport->membase + UARTCR);
+
+	uart_console_write(sport, s, count, linflex_console_putchar);
+
+	writel(ier, sport->membase + LINIER);
+}
+
+static void
+linflex_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_port *sport = linflex_ports[co->index];
+	unsigned long flags;
+	int locked = 1;
+
+	if (sport->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&sport->lock, flags);
+	else
+		spin_lock_irqsave(&sport->lock, flags);
+
+	linflex_string_write(sport, s, count);
+
+	if (locked)
+		spin_unlock_irqrestore(&sport->lock, flags);
+}
+
+/*
+ * if the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+linflex_console_get_options(struct uart_port *sport, int *parity, int *bits)
+{
+	unsigned long cr;
+
+	cr = readl(sport->membase + UARTCR);
+	cr &= LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN;
+
+	if (!cr)
+		return;
+
+	/* ok, the port was enabled */
+
+	*parity = 'n';
+	if (cr & LINFLEXD_UARTCR_PCE) {
+		if (cr & LINFLEXD_UARTCR_PC0)
+			*parity = 'o';
+		else
+			*parity = 'e';
+	}
+
+	if ((cr & LINFLEXD_UARTCR_WL0) && ((cr & LINFLEXD_UARTCR_WL1) == 0)) {
+		if (cr & LINFLEXD_UARTCR_PCE)
+			*bits = 9;
+		else
+			*bits = 8;
+	}
+}
+
+static int __init linflex_console_setup(struct console *co, char *options)
+{
+	struct uart_port *sport;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+	int i;
+	unsigned long flags;
+	/*
+	 * check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= ARRAY_SIZE(linflex_ports))
+		co->index = 0;
+
+	sport = linflex_ports[co->index];
+	if (!sport)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		linflex_console_get_options(sport, &parity, &bits);
+
+	if (earlycon_port && sport->mapbase == earlycon_port->mapbase) {
+		linflex_earlycon_same_instance = true;
+
+		spin_lock_irqsave(&init_lock, flags);
+		during_init = true;
+		spin_unlock_irqrestore(&init_lock, flags);
+
+		/* Workaround for character loss or output of many invalid
+		 * characters, when INIT mode is entered shortly after a
+		 * character has just been printed.
+		 */
+		udelay(PREINIT_DELAY);
+	}
+
+	linflex_setup_watermark(sport);
+
+	ret = uart_set_options(sport, co, baud, parity, bits, flow);
+
+	if (!linflex_earlycon_same_instance)
+		goto done;
+
+	spin_lock_irqsave(&init_lock, flags);
+
+	/* Emptying buffer */
+	if (earlycon_buf.len) {
+		for (i = 0; i < earlycon_buf.len; i++)
+			linflex_console_putchar(earlycon_port,
+				earlycon_buf.content[i]);
+
+		kfree(earlycon_buf.content);
+		earlycon_buf.len = 0;
+	}
+
+	during_init = false;
+	spin_unlock_irqrestore(&init_lock, flags);
+
+done:
+	return ret;
+}
+
+static struct uart_driver linflex_reg;
+static struct console linflex_console = {
+	.name		= DEV_NAME,
+	.write		= linflex_console_write,
+	.device		= uart_console_device,
+	.setup		= linflex_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &linflex_reg,
+};
+
+static void linflex_earlycon_write(struct console *con, const char *s,
+				   unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, linflex_earlycon_putchar);
+}
+
+static int __init linflex_early_console_setup(struct earlycon_device *device,
+					      const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = linflex_earlycon_write;
+	earlycon_port = &device->port;
+
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(linflex, "fsl,s32v234-linflexuart",
+		    linflex_early_console_setup);
+
+#define LINFLEX_CONSOLE	(&linflex_console)
+#else
+#define LINFLEX_CONSOLE	NULL
+#endif
+
+static struct uart_driver linflex_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= DEV_NAME,
+	.nr		= ARRAY_SIZE(linflex_ports),
+	.cons		= LINFLEX_CONSOLE,
+};
+
+static int linflex_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct uart_port *sport;
+	struct resource *res;
+	int ret;
+
+	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+		return ret;
+	}
+	if (ret >= UART_NR) {
+		dev_err(&pdev->dev, "driver limited to %d serial ports\n",
+			UART_NR);
+		return -ENOMEM;
+	}
+
+	sport->line = ret;
+
+	sport->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(sport->membase))
+		return PTR_ERR(sport->membase);
+	sport->mapbase = res->start;
+
+	sport->dev = &pdev->dev;
+	sport->type = PORT_LINFLEXUART;
+	sport->iotype = UPIO_MEM;
+	sport->irq = platform_get_irq(pdev, 0);
+	sport->ops = &linflex_pops;
+	sport->flags = UPF_BOOT_AUTOCONF;
+	sport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE);
+
+	linflex_ports[sport->line] = sport;
+
+	platform_set_drvdata(pdev, sport);
+
+	return uart_add_one_port(&linflex_reg, sport);
+}
+
+static int linflex_remove(struct platform_device *pdev)
+{
+	struct uart_port *sport = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&linflex_reg, sport);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int linflex_suspend(struct device *dev)
+{
+	struct uart_port *sport = dev_get_drvdata(dev);
+
+	uart_suspend_port(&linflex_reg, sport);
+
+	return 0;
+}
+
+static int linflex_resume(struct device *dev)
+{
+	struct uart_port *sport = dev_get_drvdata(dev);
+
+	uart_resume_port(&linflex_reg, sport);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume);
+
+static struct platform_driver linflex_driver = {
+	.probe		= linflex_probe,
+	.remove		= linflex_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.of_match_table	= linflex_dt_ids,
+		.pm	= &linflex_pm_ops,
+	},
+};
+
+static int __init linflex_serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&linflex_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&linflex_driver);
+	if (ret)
+		uart_unregister_driver(&linflex_reg);
+
+	return ret;
+}
+
+static void __exit linflex_serial_exit(void)
+{
+	platform_driver_unregister(&linflex_driver);
+	uart_unregister_driver(&linflex_reg);
+}
+
+module_init(linflex_serial_init);
+module_exit(linflex_serial_exit);
+
+MODULE_DESCRIPTION("Freescale LINFlexD serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
new file mode 100644
index 000000000..f72e1340b
--- /dev/null
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -0,0 +1,3245 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Freescale lpuart serial port driver
+ *
+ *  Copyright 2012-2014 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+
+/* All registers are 8-bit width */
+#define UARTBDH			0x00
+#define UARTBDL			0x01
+#define UARTCR1			0x02
+#define UARTCR2			0x03
+#define UARTSR1			0x04
+#define UARTCR3			0x06
+#define UARTDR			0x07
+#define UARTCR4			0x0a
+#define UARTCR5			0x0b
+#define UARTMODEM		0x0d
+#define UARTPFIFO		0x10
+#define UARTCFIFO		0x11
+#define UARTSFIFO		0x12
+#define UARTTWFIFO		0x13
+#define UARTTCFIFO		0x14
+#define UARTRWFIFO		0x15
+
+#define UARTBDH_LBKDIE		0x80
+#define UARTBDH_RXEDGIE		0x40
+#define UARTBDH_SBR_MASK	0x1f
+
+#define UARTCR1_LOOPS		0x80
+#define UARTCR1_RSRC		0x20
+#define UARTCR1_M		0x10
+#define UARTCR1_WAKE		0x08
+#define UARTCR1_ILT		0x04
+#define UARTCR1_PE		0x02
+#define UARTCR1_PT		0x01
+
+#define UARTCR2_TIE		0x80
+#define UARTCR2_TCIE		0x40
+#define UARTCR2_RIE		0x20
+#define UARTCR2_ILIE		0x10
+#define UARTCR2_TE		0x08
+#define UARTCR2_RE		0x04
+#define UARTCR2_RWU		0x02
+#define UARTCR2_SBK		0x01
+
+#define UARTSR1_TDRE		0x80
+#define UARTSR1_TC		0x40
+#define UARTSR1_RDRF		0x20
+#define UARTSR1_IDLE		0x10
+#define UARTSR1_OR		0x08
+#define UARTSR1_NF		0x04
+#define UARTSR1_FE		0x02
+#define UARTSR1_PE		0x01
+
+#define UARTCR3_R8		0x80
+#define UARTCR3_T8		0x40
+#define UARTCR3_TXDIR		0x20
+#define UARTCR3_TXINV		0x10
+#define UARTCR3_ORIE		0x08
+#define UARTCR3_NEIE		0x04
+#define UARTCR3_FEIE		0x02
+#define UARTCR3_PEIE		0x01
+
+#define UARTCR4_MAEN1		0x80
+#define UARTCR4_MAEN2		0x40
+#define UARTCR4_M10		0x20
+#define UARTCR4_BRFA_MASK	0x1f
+#define UARTCR4_BRFA_OFF	0
+
+#define UARTCR5_TDMAS		0x80
+#define UARTCR5_RDMAS		0x20
+
+#define UARTMODEM_RXRTSE	0x08
+#define UARTMODEM_TXRTSPOL	0x04
+#define UARTMODEM_TXRTSE	0x02
+#define UARTMODEM_TXCTSE	0x01
+
+#define UARTPFIFO_TXFE		0x80
+#define UARTPFIFO_FIFOSIZE_MASK	0x7
+#define UARTPFIFO_TXSIZE_OFF	4
+#define UARTPFIFO_RXFE		0x08
+#define UARTPFIFO_RXSIZE_OFF	0
+
+#define UARTCFIFO_TXFLUSH	0x80
+#define UARTCFIFO_RXFLUSH	0x40
+#define UARTCFIFO_RXOFE		0x04
+#define UARTCFIFO_TXOFE		0x02
+#define UARTCFIFO_RXUFE		0x01
+
+#define UARTSFIFO_TXEMPT	0x80
+#define UARTSFIFO_RXEMPT	0x40
+#define UARTSFIFO_RXOF		0x04
+#define UARTSFIFO_TXOF		0x02
+#define UARTSFIFO_RXUF		0x01
+
+/* 32-bit global registers only for i.MX7ULP/i.MX8x
+ * Used to reset all internal logic and registers, except the Global Register.
+ */
+#define UART_GLOBAL		0x8
+
+/* 32-bit register definition */
+#define UARTBAUD		0x00
+#define UARTSTAT		0x04
+#define UARTCTRL		0x08
+#define UARTDATA		0x0C
+#define UARTMATCH		0x10
+#define UARTMODIR		0x14
+#define UARTFIFO		0x18
+#define UARTWATER		0x1c
+
+#define UARTBAUD_MAEN1		0x80000000
+#define UARTBAUD_MAEN2		0x40000000
+#define UARTBAUD_M10		0x20000000
+#define UARTBAUD_TDMAE		0x00800000
+#define UARTBAUD_RDMAE		0x00200000
+#define UARTBAUD_MATCFG		0x00400000
+#define UARTBAUD_BOTHEDGE	0x00020000
+#define UARTBAUD_RESYNCDIS	0x00010000
+#define UARTBAUD_LBKDIE		0x00008000
+#define UARTBAUD_RXEDGIE	0x00004000
+#define UARTBAUD_SBNS		0x00002000
+#define UARTBAUD_SBR		0x00000000
+#define UARTBAUD_SBR_MASK	0x1fff
+#define UARTBAUD_OSR_MASK       0x1f
+#define UARTBAUD_OSR_SHIFT      24
+
+#define UARTSTAT_LBKDIF		0x80000000
+#define UARTSTAT_RXEDGIF	0x40000000
+#define UARTSTAT_MSBF		0x20000000
+#define UARTSTAT_RXINV		0x10000000
+#define UARTSTAT_RWUID		0x08000000
+#define UARTSTAT_BRK13		0x04000000
+#define UARTSTAT_LBKDE		0x02000000
+#define UARTSTAT_RAF		0x01000000
+#define UARTSTAT_TDRE		0x00800000
+#define UARTSTAT_TC		0x00400000
+#define UARTSTAT_RDRF		0x00200000
+#define UARTSTAT_IDLE		0x00100000
+#define UARTSTAT_OR		0x00080000
+#define UARTSTAT_NF		0x00040000
+#define UARTSTAT_FE		0x00020000
+#define UARTSTAT_PE		0x00010000
+#define UARTSTAT_MA1F		0x00008000
+#define UARTSTAT_M21F		0x00004000
+
+#define UARTCTRL_R8T9		0x80000000
+#define UARTCTRL_R9T8		0x40000000
+#define UARTCTRL_TXDIR		0x20000000
+#define UARTCTRL_TXINV		0x10000000
+#define UARTCTRL_ORIE		0x08000000
+#define UARTCTRL_NEIE		0x04000000
+#define UARTCTRL_FEIE		0x02000000
+#define UARTCTRL_PEIE		0x01000000
+#define UARTCTRL_TIE		0x00800000
+#define UARTCTRL_TCIE		0x00400000
+#define UARTCTRL_RIE		0x00200000
+#define UARTCTRL_ILIE		0x00100000
+#define UARTCTRL_TE		0x00080000
+#define UARTCTRL_RE		0x00040000
+#define UARTCTRL_RWU		0x00020000
+#define UARTCTRL_SBK		0x00010000
+#define UARTCTRL_MA1IE		0x00008000
+#define UARTCTRL_MA2IE		0x00004000
+#define UARTCTRL_IDLECFG	GENMASK(10, 8)
+#define UARTCTRL_LOOPS		0x00000080
+#define UARTCTRL_DOZEEN		0x00000040
+#define UARTCTRL_RSRC		0x00000020
+#define UARTCTRL_M		0x00000010
+#define UARTCTRL_WAKE		0x00000008
+#define UARTCTRL_ILT		0x00000004
+#define UARTCTRL_PE		0x00000002
+#define UARTCTRL_PT		0x00000001
+
+#define UARTDATA_NOISY		0x00008000
+#define UARTDATA_PARITYE	0x00004000
+#define UARTDATA_FRETSC		0x00002000
+#define UARTDATA_RXEMPT		0x00001000
+#define UARTDATA_IDLINE		0x00000800
+#define UARTDATA_MASK		0x3ff
+
+#define UARTMODIR_IREN		0x00020000
+#define UARTMODIR_RTSWATER	GENMASK(10, 8)
+#define UARTMODIR_TXCTSSRC	0x00000020
+#define UARTMODIR_TXCTSC	0x00000010
+#define UARTMODIR_RXRTSE	0x00000008
+#define UARTMODIR_TXRTSPOL	0x00000004
+#define UARTMODIR_TXRTSE	0x00000002
+#define UARTMODIR_TXCTSE	0x00000001
+
+#define UARTFIFO_TXEMPT		0x00800000
+#define UARTFIFO_RXEMPT		0x00400000
+#define UARTFIFO_TXOF		0x00020000
+#define UARTFIFO_RXUF		0x00010000
+#define UARTFIFO_TXFLUSH	0x00008000
+#define UARTFIFO_RXFLUSH	0x00004000
+#define UARTFIFO_RXIDEN	GENMASK(12, 10)
+#define UARTFIFO_TXOFE		0x00000200
+#define UARTFIFO_RXUFE		0x00000100
+#define UARTFIFO_TXFE		0x00000080
+#define UARTFIFO_FIFOSIZE_MASK	0x7
+#define UARTFIFO_TXSIZE_OFF	4
+#define UARTFIFO_RXFE		0x00000008
+#define UARTFIFO_RXSIZE_OFF	0
+#define UARTFIFO_DEPTH(x)	(0x1 << ((x) ? ((x) + 1) : 0))
+
+#define UARTWATER_COUNT_MASK	0xff
+#define UARTWATER_TXCNT_OFF	8
+#define UARTWATER_RXCNT_OFF	24
+#define UARTWATER_WATER_MASK	0xff
+#define UARTWATER_TXWATER_OFF	0
+#define UARTWATER_RXWATER_OFF	16
+
+#define UART_GLOBAL_RST	0x2
+#define GLOBAL_RST_MIN_US	20
+#define GLOBAL_RST_MAX_US	40
+
+/* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
+#define DMA_RX_TIMEOUT		(10)
+#define DMA_RX_IDLE_CHARS	8
+#define UART_AUTOSUSPEND_TIMEOUT	3000
+
+#define DRIVER_NAME	"fsl-lpuart"
+#define DEV_NAME	"ttyLP"
+#define UART_NR		8
+
+/* IMX lpuart has four extra unused regs located at the beginning */
+#define IMX_REG_OFF	0x10
+
+enum lpuart_type {
+	VF610_LPUART,
+	LS1021A_LPUART,
+	LS1028A_LPUART,
+	IMX7ULP_LPUART,
+	IMX8ULP_LPUART,
+	IMX8QXP_LPUART,
+	IMXRT1050_LPUART,
+};
+
+struct lpuart_port {
+	struct uart_port	port;
+	enum lpuart_type	devtype;
+	struct clk		*ipg_clk;
+	struct clk		*baud_clk;
+	unsigned int		txfifo_size;
+	unsigned int		rxfifo_size;
+
+	u8			rx_watermark;
+	bool			lpuart_dma_tx_use;
+	bool			lpuart_dma_rx_use;
+	struct dma_chan		*dma_tx_chan;
+	struct dma_chan		*dma_rx_chan;
+	struct dma_async_tx_descriptor  *dma_tx_desc;
+	struct dma_async_tx_descriptor  *dma_rx_desc;
+	dma_cookie_t		dma_tx_cookie;
+	dma_cookie_t		dma_rx_cookie;
+	unsigned int		dma_tx_bytes;
+	unsigned int		dma_rx_bytes;
+	bool			dma_tx_in_progress;
+	unsigned int		dma_rx_timeout;
+	struct timer_list	lpuart_timer;
+	struct scatterlist	rx_sgl, tx_sgl[2];
+	struct circ_buf		rx_ring;
+	int			rx_dma_rng_buf_len;
+	int                     last_residue;
+	unsigned int		dma_tx_nents;
+	wait_queue_head_t	dma_wait;
+	bool			is_cs7; /* Set to true when character size is 7 */
+					/* and the parity is enabled		*/
+	bool			dma_idle_int;
+};
+
+struct lpuart_soc_data {
+	enum lpuart_type devtype;
+	char iotype;
+	u8 reg_off;
+	u8 rx_watermark;
+};
+
+static const struct lpuart_soc_data vf_data = {
+	.devtype = VF610_LPUART,
+	.iotype = UPIO_MEM,
+	.rx_watermark = 1,
+};
+
+static const struct lpuart_soc_data ls1021a_data = {
+	.devtype = LS1021A_LPUART,
+	.iotype = UPIO_MEM32BE,
+	.rx_watermark = 1,
+};
+
+static const struct lpuart_soc_data ls1028a_data = {
+	.devtype = LS1028A_LPUART,
+	.iotype = UPIO_MEM32,
+	.rx_watermark = 0,
+};
+
+static struct lpuart_soc_data imx7ulp_data = {
+	.devtype = IMX7ULP_LPUART,
+	.iotype = UPIO_MEM32,
+	.reg_off = IMX_REG_OFF,
+	.rx_watermark = 1,
+};
+
+static struct lpuart_soc_data imx8ulp_data = {
+	.devtype = IMX8ULP_LPUART,
+	.iotype = UPIO_MEM32,
+	.reg_off = IMX_REG_OFF,
+	.rx_watermark = 3,
+};
+
+static struct lpuart_soc_data imx8qxp_data = {
+	.devtype = IMX8QXP_LPUART,
+	.iotype = UPIO_MEM32,
+	.reg_off = IMX_REG_OFF,
+	.rx_watermark = 7, /* A lower watermark is ideal for low baud rates. */
+};
+static struct lpuart_soc_data imxrt1050_data = {
+	.devtype = IMXRT1050_LPUART,
+	.iotype = UPIO_MEM32,
+	.reg_off = IMX_REG_OFF,
+	.rx_watermark = 1,
+};
+
+static const struct of_device_id lpuart_dt_ids[] = {
+	{ .compatible = "fsl,vf610-lpuart",	.data = &vf_data, },
+	{ .compatible = "fsl,ls1021a-lpuart",	.data = &ls1021a_data, },
+	{ .compatible = "fsl,ls1028a-lpuart",	.data = &ls1028a_data, },
+	{ .compatible = "fsl,imx7ulp-lpuart",	.data = &imx7ulp_data, },
+	{ .compatible = "fsl,imx8ulp-lpuart",	.data = &imx8ulp_data, },
+	{ .compatible = "fsl,imx8qxp-lpuart",	.data = &imx8qxp_data, },
+	{ .compatible = "fsl,imxrt1050-lpuart",	.data = &imxrt1050_data},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
+
+/* Forward declare this for the dma callbacks*/
+static void lpuart_dma_tx_complete(void *arg);
+
+static inline bool is_layerscape_lpuart(struct lpuart_port *sport)
+{
+	return (sport->devtype == LS1021A_LPUART ||
+		sport->devtype == LS1028A_LPUART);
+}
+
+static inline bool is_imx7ulp_lpuart(struct lpuart_port *sport)
+{
+	return sport->devtype == IMX7ULP_LPUART;
+}
+
+static inline bool is_imx8ulp_lpuart(struct lpuart_port *sport)
+{
+	return sport->devtype == IMX8ULP_LPUART;
+}
+
+static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport)
+{
+	return sport->devtype == IMX8QXP_LPUART;
+}
+
+static inline u32 lpuart32_read(struct uart_port *port, u32 off)
+{
+	switch (port->iotype) {
+	case UPIO_MEM32:
+		return readl(port->membase + off);
+	case UPIO_MEM32BE:
+		return ioread32be(port->membase + off);
+	default:
+		return 0;
+	}
+}
+
+static inline void lpuart32_write(struct uart_port *port, u32 val,
+				  u32 off)
+{
+	switch (port->iotype) {
+	case UPIO_MEM32:
+		writel(val, port->membase + off);
+		break;
+	case UPIO_MEM32BE:
+		iowrite32be(val, port->membase + off);
+		break;
+	}
+}
+
+static int __lpuart_enable_clks(struct lpuart_port *sport, bool is_en)
+{
+	int ret = 0;
+
+	if (is_en) {
+		ret = clk_prepare_enable(sport->ipg_clk);
+		if (ret)
+			return ret;
+
+		ret = clk_prepare_enable(sport->baud_clk);
+		if (ret) {
+			clk_disable_unprepare(sport->ipg_clk);
+			return ret;
+		}
+	} else {
+		clk_disable_unprepare(sport->baud_clk);
+		clk_disable_unprepare(sport->ipg_clk);
+	}
+
+	return 0;
+}
+
+static unsigned int lpuart_get_baud_clk_rate(struct lpuart_port *sport)
+{
+	if (is_imx8qxp_lpuart(sport))
+		return clk_get_rate(sport->baud_clk);
+
+	return clk_get_rate(sport->ipg_clk);
+}
+
+#define lpuart_enable_clks(x)	__lpuart_enable_clks(x, true)
+#define lpuart_disable_clks(x)	__lpuart_enable_clks(x, false)
+
+static void lpuart_stop_tx(struct uart_port *port)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2);
+	temp &= ~(UARTCR2_TIE | UARTCR2_TCIE);
+	writeb(temp, port->membase + UARTCR2);
+}
+
+static void lpuart32_stop_tx(struct uart_port *port)
+{
+	unsigned long temp;
+
+	temp = lpuart32_read(port, UARTCTRL);
+	temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE);
+	lpuart32_write(port, temp, UARTCTRL);
+}
+
+static void lpuart_stop_rx(struct uart_port *port)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2);
+	writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2);
+}
+
+static void lpuart32_stop_rx(struct uart_port *port)
+{
+	unsigned long temp;
+
+	temp = lpuart32_read(port, UARTCTRL);
+	lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL);
+}
+
+static void lpuart_dma_tx(struct lpuart_port *sport)
+{
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	struct scatterlist *sgl = sport->tx_sgl;
+	struct device *dev = sport->port.dev;
+	struct dma_chan *chan = sport->dma_tx_chan;
+	int ret;
+
+	if (sport->dma_tx_in_progress)
+		return;
+
+	sport->dma_tx_bytes = uart_circ_chars_pending(xmit);
+
+	if (xmit->tail < xmit->head || xmit->head == 0) {
+		sport->dma_tx_nents = 1;
+		sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes);
+	} else {
+		sport->dma_tx_nents = 2;
+		sg_init_table(sgl, 2);
+		sg_set_buf(sgl, xmit->buf + xmit->tail,
+				UART_XMIT_SIZE - xmit->tail);
+		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
+	}
+
+	ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents,
+			 DMA_TO_DEVICE);
+	if (!ret) {
+		dev_err(dev, "DMA mapping error for TX.\n");
+		return;
+	}
+
+	sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl,
+					ret, DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT);
+	if (!sport->dma_tx_desc) {
+		dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
+			      DMA_TO_DEVICE);
+		dev_err(dev, "Cannot prepare TX slave DMA!\n");
+		return;
+	}
+
+	sport->dma_tx_desc->callback = lpuart_dma_tx_complete;
+	sport->dma_tx_desc->callback_param = sport;
+	sport->dma_tx_in_progress = true;
+	sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
+	dma_async_issue_pending(chan);
+}
+
+static bool lpuart_stopped_or_empty(struct uart_port *port)
+{
+	return uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port);
+}
+
+static void lpuart_dma_tx_complete(void *arg)
+{
+	struct lpuart_port *sport = arg;
+	struct scatterlist *sgl = &sport->tx_sgl[0];
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	struct dma_chan *chan = sport->dma_tx_chan;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	if (!sport->dma_tx_in_progress) {
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+		return;
+	}
+
+	dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
+		     DMA_TO_DEVICE);
+
+	uart_xmit_advance(&sport->port, sport->dma_tx_bytes);
+	sport->dma_tx_in_progress = false;
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+	if (waitqueue_active(&sport->dma_wait)) {
+		wake_up(&sport->dma_wait);
+		return;
+	}
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	if (!lpuart_stopped_or_empty(&sport->port))
+		lpuart_dma_tx(sport);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport)
+{
+	switch (sport->port.iotype) {
+	case UPIO_MEM32:
+		return sport->port.mapbase + UARTDATA;
+	case UPIO_MEM32BE:
+		return sport->port.mapbase + UARTDATA + sizeof(u32) - 1;
+	}
+	return sport->port.mapbase + UARTDR;
+}
+
+static int lpuart_dma_tx_request(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port,
+					struct lpuart_port, port);
+	struct dma_slave_config dma_tx_sconfig = {};
+	int ret;
+
+	dma_tx_sconfig.dst_addr = lpuart_dma_datareg_addr(sport);
+	dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma_tx_sconfig.dst_maxburst = 1;
+	dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
+	ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
+
+	if (ret) {
+		dev_err(sport->port.dev,
+				"DMA slave config failed, err = %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static bool lpuart_is_32(struct lpuart_port *sport)
+{
+	return sport->port.iotype == UPIO_MEM32 ||
+	       sport->port.iotype ==  UPIO_MEM32BE;
+}
+
+static void lpuart_flush_buffer(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	struct dma_chan *chan = sport->dma_tx_chan;
+	u32 val;
+
+	if (sport->lpuart_dma_tx_use) {
+		if (sport->dma_tx_in_progress) {
+			dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0],
+				sport->dma_tx_nents, DMA_TO_DEVICE);
+			sport->dma_tx_in_progress = false;
+		}
+		dmaengine_terminate_async(chan);
+	}
+
+	if (lpuart_is_32(sport)) {
+		val = lpuart32_read(&sport->port, UARTFIFO);
+		val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
+		lpuart32_write(&sport->port, val, UARTFIFO);
+	} else {
+		val = readb(sport->port.membase + UARTCFIFO);
+		val |= UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH;
+		writeb(val, sport->port.membase + UARTCFIFO);
+	}
+}
+
+static void lpuart_wait_bit_set(struct uart_port *port, unsigned int offset,
+				u8 bit)
+{
+	while (!(readb(port->membase + offset) & bit))
+		cpu_relax();
+}
+
+static void lpuart32_wait_bit_set(struct uart_port *port, unsigned int offset,
+				  u32 bit)
+{
+	while (!(lpuart32_read(port, offset) & bit))
+		cpu_relax();
+}
+
+#if defined(CONFIG_CONSOLE_POLL)
+
+static int lpuart_poll_init(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port,
+					struct lpuart_port, port);
+	unsigned long flags;
+	unsigned char temp;
+
+	sport->port.fifosize = 0;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	/* Disable Rx & Tx */
+	writeb(0, sport->port.membase + UARTCR2);
+
+	temp = readb(sport->port.membase + UARTPFIFO);
+	/* Enable Rx and Tx FIFO */
+	writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE,
+			sport->port.membase + UARTPFIFO);
+
+	/* flush Tx and Rx FIFO */
+	writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
+			sport->port.membase + UARTCFIFO);
+
+	/* explicitly clear RDRF */
+	if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
+		readb(sport->port.membase + UARTDR);
+		writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
+	}
+
+	writeb(0, sport->port.membase + UARTTWFIFO);
+	writeb(1, sport->port.membase + UARTRWFIFO);
+
+	/* Enable Rx and Tx */
+	writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	return 0;
+}
+
+static void lpuart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	/* drain */
+	lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE);
+	writeb(c, port->membase + UARTDR);
+}
+
+static int lpuart_poll_get_char(struct uart_port *port)
+{
+	if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF))
+		return NO_POLL_CHAR;
+
+	return readb(port->membase + UARTDR);
+}
+
+static int lpuart32_poll_init(struct uart_port *port)
+{
+	unsigned long flags;
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	u32 temp;
+
+	sport->port.fifosize = 0;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	/* Disable Rx & Tx */
+	lpuart32_write(&sport->port, 0, UARTCTRL);
+
+	temp = lpuart32_read(&sport->port, UARTFIFO);
+
+	/* Enable Rx and Tx FIFO */
+	lpuart32_write(&sport->port, temp | UARTFIFO_RXFE | UARTFIFO_TXFE, UARTFIFO);
+
+	/* flush Tx and Rx FIFO */
+	lpuart32_write(&sport->port, UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH, UARTFIFO);
+
+	/* explicitly clear RDRF */
+	if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) {
+		lpuart32_read(&sport->port, UARTDATA);
+		lpuart32_write(&sport->port, UARTFIFO_RXUF, UARTFIFO);
+	}
+
+	/* Enable Rx and Tx */
+	lpuart32_write(&sport->port, UARTCTRL_RE | UARTCTRL_TE, UARTCTRL);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	return 0;
+}
+
+static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE);
+	lpuart32_write(port, c, UARTDATA);
+}
+
+static int lpuart32_poll_get_char(struct uart_port *port)
+{
+	if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF))
+		return NO_POLL_CHAR;
+
+	return lpuart32_read(port, UARTDATA);
+}
+#endif
+
+static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
+{
+	struct uart_port *port = &sport->port;
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		readb(port->membase + UARTTCFIFO) < sport->txfifo_size,
+		writeb(ch, port->membase + UARTDR));
+}
+
+static inline void lpuart32_transmit_buffer(struct lpuart_port *sport)
+{
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	unsigned long txcnt;
+
+	if (sport->port.x_char) {
+		lpuart32_write(&sport->port, sport->port.x_char, UARTDATA);
+		sport->port.icount.tx++;
+		sport->port.x_char = 0;
+		return;
+	}
+
+	if (lpuart_stopped_or_empty(&sport->port)) {
+		lpuart32_stop_tx(&sport->port);
+		return;
+	}
+
+	txcnt = lpuart32_read(&sport->port, UARTWATER);
+	txcnt = txcnt >> UARTWATER_TXCNT_OFF;
+	txcnt &= UARTWATER_COUNT_MASK;
+	while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) {
+		lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA);
+		uart_xmit_advance(&sport->port, 1);
+		txcnt = lpuart32_read(&sport->port, UARTWATER);
+		txcnt = txcnt >> UARTWATER_TXCNT_OFF;
+		txcnt &= UARTWATER_COUNT_MASK;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+	if (uart_circ_empty(xmit))
+		lpuart32_stop_tx(&sport->port);
+}
+
+static void lpuart_start_tx(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port,
+			struct lpuart_port, port);
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2);
+	writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
+
+	if (sport->lpuart_dma_tx_use) {
+		if (!lpuart_stopped_or_empty(port))
+			lpuart_dma_tx(sport);
+	} else {
+		if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
+			lpuart_transmit_buffer(sport);
+	}
+}
+
+static void lpuart32_start_tx(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned long temp;
+
+	if (sport->lpuart_dma_tx_use) {
+		if (!lpuart_stopped_or_empty(port))
+			lpuart_dma_tx(sport);
+	} else {
+		temp = lpuart32_read(port, UARTCTRL);
+		lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL);
+
+		if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE)
+			lpuart32_transmit_buffer(sport);
+	}
+}
+
+static void
+lpuart_uart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
+{
+	switch (state) {
+	case UART_PM_STATE_OFF:
+		pm_runtime_mark_last_busy(port->dev);
+		pm_runtime_put_autosuspend(port->dev);
+		break;
+	default:
+		pm_runtime_get_sync(port->dev);
+		break;
+	}
+}
+
+/* return TIOCSER_TEMT when transmitter is not busy */
+static unsigned int lpuart_tx_empty(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port,
+			struct lpuart_port, port);
+	unsigned char sr1 = readb(port->membase + UARTSR1);
+	unsigned char sfifo = readb(port->membase + UARTSFIFO);
+
+	if (sport->dma_tx_in_progress)
+		return 0;
+
+	if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static unsigned int lpuart32_tx_empty(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port,
+			struct lpuart_port, port);
+	unsigned long stat = lpuart32_read(port, UARTSTAT);
+	unsigned long sfifo = lpuart32_read(port, UARTFIFO);
+	unsigned long ctrl = lpuart32_read(port, UARTCTRL);
+
+	if (sport->dma_tx_in_progress)
+		return 0;
+
+	/*
+	 * LPUART Transmission Complete Flag may never be set while queuing a break
+	 * character, so avoid checking for transmission complete when UARTCTRL_SBK
+	 * is asserted.
+	 */
+	if ((stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) || ctrl & UARTCTRL_SBK)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static void lpuart_txint(struct lpuart_port *sport)
+{
+	spin_lock(&sport->port.lock);
+	lpuart_transmit_buffer(sport);
+	spin_unlock(&sport->port.lock);
+}
+
+static void lpuart_rxint(struct lpuart_port *sport)
+{
+	unsigned int flg, ignored = 0, overrun = 0;
+	struct tty_port *port = &sport->port.state->port;
+	unsigned char rx, sr;
+
+	spin_lock(&sport->port.lock);
+
+	while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
+		flg = TTY_NORMAL;
+		sport->port.icount.rx++;
+		/*
+		 * to clear the FE, OR, NF, FE, PE flags,
+		 * read SR1 then read DR
+		 */
+		sr = readb(sport->port.membase + UARTSR1);
+		rx = readb(sport->port.membase + UARTDR);
+
+		if (uart_prepare_sysrq_char(&sport->port, rx))
+			continue;
+
+		if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
+			if (sr & UARTSR1_PE)
+				sport->port.icount.parity++;
+			else if (sr & UARTSR1_FE)
+				sport->port.icount.frame++;
+
+			if (sr & UARTSR1_OR)
+				overrun++;
+
+			if (sr & sport->port.ignore_status_mask) {
+				if (++ignored > 100)
+					goto out;
+				continue;
+			}
+
+			sr &= sport->port.read_status_mask;
+
+			if (sr & UARTSR1_PE)
+				flg = TTY_PARITY;
+			else if (sr & UARTSR1_FE)
+				flg = TTY_FRAME;
+
+			if (sr & UARTSR1_OR)
+				flg = TTY_OVERRUN;
+
+			sport->port.sysrq = 0;
+		}
+
+		if (tty_insert_flip_char(port, rx, flg) == 0)
+			sport->port.icount.buf_overrun++;
+	}
+
+out:
+	if (overrun) {
+		sport->port.icount.overrun += overrun;
+
+		/*
+		 * Overruns cause FIFO pointers to become missaligned.
+		 * Flushing the receive FIFO reinitializes the pointers.
+		 */
+		writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO);
+		writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO);
+	}
+
+	uart_unlock_and_check_sysrq(&sport->port);
+
+	tty_flip_buffer_push(port);
+}
+
+static void lpuart32_txint(struct lpuart_port *sport)
+{
+	spin_lock(&sport->port.lock);
+	lpuart32_transmit_buffer(sport);
+	spin_unlock(&sport->port.lock);
+}
+
+static void lpuart32_rxint(struct lpuart_port *sport)
+{
+	unsigned int flg, ignored = 0;
+	struct tty_port *port = &sport->port.state->port;
+	unsigned long rx, sr;
+	bool is_break;
+
+	spin_lock(&sport->port.lock);
+
+	while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) {
+		flg = TTY_NORMAL;
+		sport->port.icount.rx++;
+		/*
+		 * to clear the FE, OR, NF, FE, PE flags,
+		 * read STAT then read DATA reg
+		 */
+		sr = lpuart32_read(&sport->port, UARTSTAT);
+		rx = lpuart32_read(&sport->port, UARTDATA);
+		rx &= UARTDATA_MASK;
+
+		/*
+		 * The LPUART can't distinguish between a break and a framing error,
+		 * thus we assume it is a break if the received data is zero.
+		 */
+		is_break = (sr & UARTSTAT_FE) && !rx;
+
+		if (is_break && uart_handle_break(&sport->port))
+			continue;
+
+		if (uart_prepare_sysrq_char(&sport->port, rx))
+			continue;
+
+		if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) {
+			if (sr & UARTSTAT_PE) {
+				sport->port.icount.parity++;
+			} else if (sr & UARTSTAT_FE) {
+				if (is_break)
+					sport->port.icount.brk++;
+				else
+					sport->port.icount.frame++;
+			}
+
+			if (sr & UARTSTAT_OR)
+				sport->port.icount.overrun++;
+
+			if (sr & sport->port.ignore_status_mask) {
+				if (++ignored > 100)
+					goto out;
+				continue;
+			}
+
+			sr &= sport->port.read_status_mask;
+
+			if (sr & UARTSTAT_PE) {
+				flg = TTY_PARITY;
+			} else if (sr & UARTSTAT_FE) {
+				if (is_break)
+					flg = TTY_BREAK;
+				else
+					flg = TTY_FRAME;
+			}
+
+			if (sr & UARTSTAT_OR)
+				flg = TTY_OVERRUN;
+		}
+
+		if (sport->is_cs7)
+			rx &= 0x7F;
+
+		if (tty_insert_flip_char(port, rx, flg) == 0)
+			sport->port.icount.buf_overrun++;
+	}
+
+out:
+	uart_unlock_and_check_sysrq(&sport->port);
+
+	tty_flip_buffer_push(port);
+}
+
+static irqreturn_t lpuart_int(int irq, void *dev_id)
+{
+	struct lpuart_port *sport = dev_id;
+	unsigned char sts;
+
+	sts = readb(sport->port.membase + UARTSR1);
+
+	/* SysRq, using dma, check for linebreak by framing err. */
+	if (sts & UARTSR1_FE && sport->lpuart_dma_rx_use) {
+		readb(sport->port.membase + UARTDR);
+		uart_handle_break(&sport->port);
+		/* linebreak produces some garbage, removing it */
+		writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO);
+		return IRQ_HANDLED;
+	}
+
+	if (sts & UARTSR1_RDRF && !sport->lpuart_dma_rx_use)
+		lpuart_rxint(sport);
+
+	if (sts & UARTSR1_TDRE && !sport->lpuart_dma_tx_use)
+		lpuart_txint(sport);
+
+	return IRQ_HANDLED;
+}
+
+static inline void lpuart_handle_sysrq_chars(struct uart_port *port,
+					     unsigned char *p, int count)
+{
+	while (count--) {
+		if (*p && uart_handle_sysrq_char(port, *p))
+			return;
+		p++;
+	}
+}
+
+static void lpuart_handle_sysrq(struct lpuart_port *sport)
+{
+	struct circ_buf *ring = &sport->rx_ring;
+	int count;
+
+	if (ring->head < ring->tail) {
+		count = sport->rx_sgl.length - ring->tail;
+		lpuart_handle_sysrq_chars(&sport->port,
+					  ring->buf + ring->tail, count);
+		ring->tail = 0;
+	}
+
+	if (ring->head > ring->tail) {
+		count = ring->head - ring->tail;
+		lpuart_handle_sysrq_chars(&sport->port,
+					  ring->buf + ring->tail, count);
+		ring->tail = ring->head;
+	}
+}
+
+static int lpuart_tty_insert_flip_string(struct tty_port *port,
+	unsigned char *chars, size_t size, bool is_cs7)
+{
+	int i;
+
+	if (is_cs7)
+		for (i = 0; i < size; i++)
+			chars[i] &= 0x7F;
+	return tty_insert_flip_string(port, chars, size);
+}
+
+static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
+{
+	struct tty_port *port = &sport->port.state->port;
+	struct dma_tx_state state;
+	enum dma_status dmastat;
+	struct dma_chan *chan = sport->dma_rx_chan;
+	struct circ_buf *ring = &sport->rx_ring;
+	unsigned long flags;
+	int count, copied;
+
+	if (lpuart_is_32(sport)) {
+		unsigned long sr = lpuart32_read(&sport->port, UARTSTAT);
+
+		if (sr & (UARTSTAT_PE | UARTSTAT_FE)) {
+			/* Clear the error flags */
+			lpuart32_write(&sport->port, sr, UARTSTAT);
+
+			if (sr & UARTSTAT_PE)
+				sport->port.icount.parity++;
+			else if (sr & UARTSTAT_FE)
+				sport->port.icount.frame++;
+		}
+	} else {
+		unsigned char sr = readb(sport->port.membase + UARTSR1);
+
+		if (sr & (UARTSR1_PE | UARTSR1_FE)) {
+			unsigned char cr2;
+
+			/* Disable receiver during this operation... */
+			cr2 = readb(sport->port.membase + UARTCR2);
+			cr2 &= ~UARTCR2_RE;
+			writeb(cr2, sport->port.membase + UARTCR2);
+
+			/* Read DR to clear the error flags */
+			readb(sport->port.membase + UARTDR);
+
+			if (sr & UARTSR1_PE)
+				sport->port.icount.parity++;
+			else if (sr & UARTSR1_FE)
+				sport->port.icount.frame++;
+			/*
+			 * At this point parity/framing error is
+			 * cleared However, since the DMA already read
+			 * the data register and we had to read it
+			 * again after reading the status register to
+			 * properly clear the flags, the FIFO actually
+			 * underflowed... This requires a clearing of
+			 * the FIFO...
+			 */
+			if (readb(sport->port.membase + UARTSFIFO) &
+			    UARTSFIFO_RXUF) {
+				writeb(UARTSFIFO_RXUF,
+				       sport->port.membase + UARTSFIFO);
+				writeb(UARTCFIFO_RXFLUSH,
+				       sport->port.membase + UARTCFIFO);
+			}
+
+			cr2 |= UARTCR2_RE;
+			writeb(cr2, sport->port.membase + UARTCR2);
+		}
+	}
+
+	async_tx_ack(sport->dma_rx_desc);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
+	if (dmastat == DMA_ERROR) {
+		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+		return;
+	}
+
+	/* CPU claims ownership of RX DMA buffer */
+	dma_sync_sg_for_cpu(chan->device->dev, &sport->rx_sgl, 1,
+			    DMA_FROM_DEVICE);
+
+	/*
+	 * ring->head points to the end of data already written by the DMA.
+	 * ring->tail points to the beginning of data to be read by the
+	 * framework.
+	 * The current transfer size should not be larger than the dma buffer
+	 * length.
+	 */
+	ring->head = sport->rx_sgl.length - state.residue;
+	BUG_ON(ring->head > sport->rx_sgl.length);
+
+	/*
+	 * Silent handling of keys pressed in the sysrq timeframe
+	 */
+	if (sport->port.sysrq) {
+		lpuart_handle_sysrq(sport);
+		goto exit;
+	}
+
+	/*
+	 * At this point ring->head may point to the first byte right after the
+	 * last byte of the dma buffer:
+	 * 0 <= ring->head <= sport->rx_sgl.length
+	 *
+	 * However ring->tail must always points inside the dma buffer:
+	 * 0 <= ring->tail <= sport->rx_sgl.length - 1
+	 *
+	 * Since we use a ring buffer, we have to handle the case
+	 * where head is lower than tail. In such a case, we first read from
+	 * tail to the end of the buffer then reset tail.
+	 */
+	if (ring->head < ring->tail) {
+		count = sport->rx_sgl.length - ring->tail;
+
+		copied = lpuart_tty_insert_flip_string(port, ring->buf + ring->tail,
+					count, sport->is_cs7);
+		if (copied != count)
+			sport->port.icount.buf_overrun++;
+		ring->tail = 0;
+		sport->port.icount.rx += copied;
+	}
+
+	/* Finally we read data from tail to head */
+	if (ring->tail < ring->head) {
+		count = ring->head - ring->tail;
+		copied = lpuart_tty_insert_flip_string(port, ring->buf + ring->tail,
+					count, sport->is_cs7);
+		if (copied != count)
+			sport->port.icount.buf_overrun++;
+		/* Wrap ring->head if needed */
+		if (ring->head >= sport->rx_sgl.length)
+			ring->head = 0;
+		ring->tail = ring->head;
+		sport->port.icount.rx += copied;
+	}
+
+	sport->last_residue = state.residue;
+
+exit:
+	dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1,
+			       DMA_FROM_DEVICE);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	tty_flip_buffer_push(port);
+	if (!sport->dma_idle_int)
+		mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
+}
+
+static void lpuart_dma_rx_complete(void *arg)
+{
+	struct lpuart_port *sport = arg;
+
+	lpuart_copy_rx_to_tty(sport);
+}
+
+static void lpuart32_dma_idleint(struct lpuart_port *sport)
+{
+	enum dma_status dmastat;
+	struct dma_chan *chan = sport->dma_rx_chan;
+	struct circ_buf *ring = &sport->rx_ring;
+	struct dma_tx_state state;
+	int count = 0;
+
+	dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
+	if (dmastat == DMA_ERROR) {
+		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
+		return;
+	}
+
+	ring->head = sport->rx_sgl.length - state.residue;
+	count = CIRC_CNT(ring->head, ring->tail, sport->rx_sgl.length);
+
+	/* Check if new data received before copying */
+	if (count)
+		lpuart_copy_rx_to_tty(sport);
+}
+
+static irqreturn_t lpuart32_int(int irq, void *dev_id)
+{
+	struct lpuart_port *sport = dev_id;
+	unsigned long sts, rxcount;
+
+	sts = lpuart32_read(&sport->port, UARTSTAT);
+	rxcount = lpuart32_read(&sport->port, UARTWATER);
+	rxcount = rxcount >> UARTWATER_RXCNT_OFF;
+
+	if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use)
+		lpuart32_rxint(sport);
+
+	if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use)
+		lpuart32_txint(sport);
+
+	if ((sts & UARTSTAT_IDLE) && sport->lpuart_dma_rx_use && sport->dma_idle_int)
+		lpuart32_dma_idleint(sport);
+
+	lpuart32_write(&sport->port, sts, UARTSTAT);
+	return IRQ_HANDLED;
+}
+
+/*
+ * Timer function to simulate the hardware EOP (End Of Package) event.
+ * The timer callback is to check for new RX data and copy to TTY buffer.
+ * If no new data are received since last interval, the EOP condition is
+ * met, complete the DMA transfer by copying the data. Otherwise, just
+ * restart timer.
+ */
+static void lpuart_timer_func(struct timer_list *t)
+{
+	struct lpuart_port *sport = from_timer(sport, t, lpuart_timer);
+	enum dma_status dmastat;
+	struct dma_chan *chan = sport->dma_rx_chan;
+	struct circ_buf *ring = &sport->rx_ring;
+	struct dma_tx_state state;
+	unsigned long flags;
+	int count;
+
+	dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
+	if (dmastat == DMA_ERROR) {
+		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
+		return;
+	}
+
+	ring->head = sport->rx_sgl.length - state.residue;
+	count = CIRC_CNT(ring->head, ring->tail, sport->rx_sgl.length);
+
+	/* Check if new data received before copying */
+	if ((count != 0) && (sport->last_residue == state.residue))
+		lpuart_copy_rx_to_tty(sport);
+	else
+		mod_timer(&sport->lpuart_timer,
+			  jiffies + sport->dma_rx_timeout);
+
+	if (spin_trylock_irqsave(&sport->port.lock, flags)) {
+		sport->last_residue = state.residue;
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+	}
+}
+
+static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
+{
+	struct dma_slave_config dma_rx_sconfig = {};
+	struct circ_buf *ring = &sport->rx_ring;
+	int ret, nent;
+	struct tty_port *port = &sport->port.state->port;
+	struct tty_struct *tty = port->tty;
+	struct ktermios *termios = &tty->termios;
+	struct dma_chan *chan = sport->dma_rx_chan;
+	unsigned int bits = tty_get_frame_size(termios->c_cflag);
+	unsigned int baud = tty_get_baud_rate(tty);
+
+	/*
+	 * Calculate length of one DMA buffer size to keep latency below
+	 * 10ms at any baud rate.
+	 */
+	sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud /  bits / 1000) * 2;
+	sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len));
+	sport->rx_dma_rng_buf_len = max_t(int,
+					  sport->rxfifo_size * 2,
+					  sport->rx_dma_rng_buf_len);
+	/*
+	 * Keep this condition check in case rxfifo_size is unavailable
+	 * for some SoCs.
+	 */
+	if (sport->rx_dma_rng_buf_len < 16)
+		sport->rx_dma_rng_buf_len = 16;
+
+	sport->last_residue = 0;
+	sport->dma_rx_timeout = max(nsecs_to_jiffies(
+		sport->port.frame_time * DMA_RX_IDLE_CHARS), 1UL);
+
+	ring->buf = kzalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC);
+	if (!ring->buf)
+		return -ENOMEM;
+
+	sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
+	nent = dma_map_sg(chan->device->dev, &sport->rx_sgl, 1,
+			  DMA_FROM_DEVICE);
+
+	if (!nent) {
+		dev_err(sport->port.dev, "DMA Rx mapping error\n");
+		return -EINVAL;
+	}
+
+	dma_rx_sconfig.src_addr = lpuart_dma_datareg_addr(sport);
+	dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma_rx_sconfig.src_maxburst = 1;
+	dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
+	ret = dmaengine_slave_config(chan, &dma_rx_sconfig);
+
+	if (ret < 0) {
+		dev_err(sport->port.dev,
+				"DMA Rx slave config failed, err = %d\n", ret);
+		return ret;
+	}
+
+	sport->dma_rx_desc = dmaengine_prep_dma_cyclic(chan,
+				 sg_dma_address(&sport->rx_sgl),
+				 sport->rx_sgl.length,
+				 sport->rx_sgl.length / 2,
+				 DMA_DEV_TO_MEM,
+				 DMA_PREP_INTERRUPT);
+	if (!sport->dma_rx_desc) {
+		dev_err(sport->port.dev, "Cannot prepare cyclic DMA\n");
+		return -EFAULT;
+	}
+
+	sport->dma_rx_desc->callback = lpuart_dma_rx_complete;
+	sport->dma_rx_desc->callback_param = sport;
+	sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc);
+	dma_async_issue_pending(chan);
+
+	if (lpuart_is_32(sport)) {
+		unsigned long temp = lpuart32_read(&sport->port, UARTBAUD);
+
+		lpuart32_write(&sport->port, temp | UARTBAUD_RDMAE, UARTBAUD);
+
+		if (sport->dma_idle_int) {
+			unsigned long ctrl = lpuart32_read(&sport->port, UARTCTRL);
+
+			lpuart32_write(&sport->port, ctrl | UARTCTRL_ILIE, UARTCTRL);
+		}
+	} else {
+		writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS,
+		       sport->port.membase + UARTCR5);
+	}
+
+	return 0;
+}
+
+static void lpuart_dma_rx_free(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port,
+					struct lpuart_port, port);
+	struct dma_chan *chan = sport->dma_rx_chan;
+
+	dmaengine_terminate_sync(chan);
+	if (!sport->dma_idle_int)
+		del_timer_sync(&sport->lpuart_timer);
+
+	dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
+	kfree(sport->rx_ring.buf);
+	sport->rx_ring.tail = 0;
+	sport->rx_ring.head = 0;
+	sport->dma_rx_desc = NULL;
+	sport->dma_rx_cookie = -EINVAL;
+}
+
+static int lpuart_config_rs485(struct uart_port *port, struct ktermios *termios,
+			struct serial_rs485 *rs485)
+{
+	struct lpuart_port *sport = container_of(port,
+			struct lpuart_port, port);
+
+	u8 modem = readb(sport->port.membase + UARTMODEM) &
+		~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE);
+	writeb(modem, sport->port.membase + UARTMODEM);
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		/* Enable auto RS-485 RTS mode */
+		modem |= UARTMODEM_TXRTSE;
+
+		/*
+		 * The hardware defaults to RTS logic HIGH while transfer.
+		 * Switch polarity in case RTS shall be logic HIGH
+		 * after transfer.
+		 * Note: UART is assumed to be active high.
+		 */
+		if (rs485->flags & SER_RS485_RTS_ON_SEND)
+			modem |= UARTMODEM_TXRTSPOL;
+		else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
+			modem &= ~UARTMODEM_TXRTSPOL;
+	}
+
+	writeb(modem, sport->port.membase + UARTMODEM);
+	return 0;
+}
+
+static int lpuart32_config_rs485(struct uart_port *port, struct ktermios *termios,
+			struct serial_rs485 *rs485)
+{
+	struct lpuart_port *sport = container_of(port,
+			struct lpuart_port, port);
+
+	unsigned long modem = lpuart32_read(&sport->port, UARTMODIR)
+				& ~(UARTMODIR_TXRTSPOL | UARTMODIR_TXRTSE);
+	lpuart32_write(&sport->port, modem, UARTMODIR);
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		/* Enable auto RS-485 RTS mode */
+		modem |= UARTMODIR_TXRTSE;
+
+		/*
+		 * The hardware defaults to RTS logic HIGH while transfer.
+		 * Switch polarity in case RTS shall be logic HIGH
+		 * after transfer.
+		 * Note: UART is assumed to be active high.
+		 */
+		if (rs485->flags & SER_RS485_RTS_ON_SEND)
+			modem |= UARTMODIR_TXRTSPOL;
+		else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
+			modem &= ~UARTMODIR_TXRTSPOL;
+	}
+
+	lpuart32_write(&sport->port, modem, UARTMODIR);
+	return 0;
+}
+
+static unsigned int lpuart_get_mctrl(struct uart_port *port)
+{
+	unsigned int mctrl = 0;
+	u8 reg;
+
+	reg = readb(port->membase + UARTCR1);
+	if (reg & UARTCR1_LOOPS)
+		mctrl |= TIOCM_LOOP;
+
+	return mctrl;
+}
+
+static unsigned int lpuart32_get_mctrl(struct uart_port *port)
+{
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+	u32 reg;
+
+	reg = lpuart32_read(port, UARTCTRL);
+	if (reg & UARTCTRL_LOOPS)
+		mctrl |= TIOCM_LOOP;
+
+	return mctrl;
+}
+
+static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u8 reg;
+
+	reg = readb(port->membase + UARTCR1);
+
+	/* for internal loopback we need LOOPS=1 and RSRC=0 */
+	reg &= ~(UARTCR1_LOOPS | UARTCR1_RSRC);
+	if (mctrl & TIOCM_LOOP)
+		reg |= UARTCR1_LOOPS;
+
+	writeb(reg, port->membase + UARTCR1);
+}
+
+static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 reg;
+
+	reg = lpuart32_read(port, UARTCTRL);
+
+	/* for internal loopback we need LOOPS=1 and RSRC=0 */
+	reg &= ~(UARTCTRL_LOOPS | UARTCTRL_RSRC);
+	if (mctrl & TIOCM_LOOP)
+		reg |= UARTCTRL_LOOPS;
+
+	lpuart32_write(port, reg, UARTCTRL);
+}
+
+static void lpuart_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK;
+
+	if (break_state != 0)
+		temp |= UARTCR2_SBK;
+
+	writeb(temp, port->membase + UARTCR2);
+}
+
+static void lpuart32_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long temp;
+
+	temp = lpuart32_read(port, UARTCTRL);
+
+	/*
+	 * LPUART IP now has two known bugs, one is CTS has higher priority than the
+	 * break signal, which causes the break signal sending through UARTCTRL_SBK
+	 * may impacted by the CTS input if the HW flow control is enabled. It
+	 * exists on all platforms we support in this driver.
+	 * Another bug is i.MX8QM LPUART may have an additional break character
+	 * being sent after SBK was cleared.
+	 * To avoid above two bugs, we use Transmit Data Inversion function to send
+	 * the break signal instead of UARTCTRL_SBK.
+	 */
+	if (break_state != 0) {
+		/*
+		 * Disable the transmitter to prevent any data from being sent out
+		 * during break, then invert the TX line to send break.
+		 */
+		temp &= ~UARTCTRL_TE;
+		lpuart32_write(port, temp, UARTCTRL);
+		temp |= UARTCTRL_TXINV;
+		lpuart32_write(port, temp, UARTCTRL);
+	} else {
+		/* Disable the TXINV to turn off break and re-enable transmitter. */
+		temp &= ~UARTCTRL_TXINV;
+		lpuart32_write(port, temp, UARTCTRL);
+		temp |= UARTCTRL_TE;
+		lpuart32_write(port, temp, UARTCTRL);
+	}
+}
+
+static void lpuart_setup_watermark(struct lpuart_port *sport)
+{
+	unsigned char val, cr2;
+	unsigned char cr2_saved;
+
+	cr2 = readb(sport->port.membase + UARTCR2);
+	cr2_saved = cr2;
+	cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE |
+			UARTCR2_RIE | UARTCR2_RE);
+	writeb(cr2, sport->port.membase + UARTCR2);
+
+	val = readb(sport->port.membase + UARTPFIFO);
+	writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE,
+			sport->port.membase + UARTPFIFO);
+
+	/* flush Tx and Rx FIFO */
+	writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
+			sport->port.membase + UARTCFIFO);
+
+	/* explicitly clear RDRF */
+	if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
+		readb(sport->port.membase + UARTDR);
+		writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
+	}
+
+	if (uart_console(&sport->port))
+		sport->rx_watermark = 1;
+	writeb(0, sport->port.membase + UARTTWFIFO);
+	writeb(sport->rx_watermark, sport->port.membase + UARTRWFIFO);
+
+	/* Restore cr2 */
+	writeb(cr2_saved, sport->port.membase + UARTCR2);
+}
+
+static void lpuart_setup_watermark_enable(struct lpuart_port *sport)
+{
+	unsigned char cr2;
+
+	lpuart_setup_watermark(sport);
+
+	cr2 = readb(sport->port.membase + UARTCR2);
+	cr2 |= UARTCR2_RIE | UARTCR2_RE | UARTCR2_TE;
+	writeb(cr2, sport->port.membase + UARTCR2);
+}
+
+static void lpuart32_setup_watermark(struct lpuart_port *sport)
+{
+	unsigned long val, ctrl;
+	unsigned long ctrl_saved;
+
+	ctrl = lpuart32_read(&sport->port, UARTCTRL);
+	ctrl_saved = ctrl;
+	ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE |
+			UARTCTRL_RIE | UARTCTRL_RE | UARTCTRL_ILIE);
+	lpuart32_write(&sport->port, ctrl, UARTCTRL);
+
+	/* enable FIFO mode */
+	val = lpuart32_read(&sport->port, UARTFIFO);
+	val |= UARTFIFO_TXFE | UARTFIFO_RXFE;
+	val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
+	val |= FIELD_PREP(UARTFIFO_RXIDEN, 0x3);
+	lpuart32_write(&sport->port, val, UARTFIFO);
+
+	/* set the watermark */
+	if (uart_console(&sport->port))
+		sport->rx_watermark = 1;
+	val = (sport->rx_watermark << UARTWATER_RXWATER_OFF) |
+	      (0x0 << UARTWATER_TXWATER_OFF);
+	lpuart32_write(&sport->port, val, UARTWATER);
+
+	/* set RTS watermark */
+	if (!uart_console(&sport->port)) {
+		val = lpuart32_read(&sport->port, UARTMODIR);
+		val |= FIELD_PREP(UARTMODIR_RTSWATER, sport->rxfifo_size >> 1);
+		lpuart32_write(&sport->port, val, UARTMODIR);
+	}
+
+	/* Restore cr2 */
+	lpuart32_write(&sport->port, ctrl_saved, UARTCTRL);
+}
+
+static void lpuart32_setup_watermark_enable(struct lpuart_port *sport)
+{
+	u32 temp;
+
+	lpuart32_setup_watermark(sport);
+
+	temp = lpuart32_read(&sport->port, UARTCTRL);
+	temp |= UARTCTRL_RE | UARTCTRL_TE;
+	temp |= FIELD_PREP(UARTCTRL_IDLECFG, 0x7);
+	lpuart32_write(&sport->port, temp, UARTCTRL);
+}
+
+static void rx_dma_timer_init(struct lpuart_port *sport)
+{
+	if (sport->dma_idle_int)
+		return;
+
+	timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0);
+	sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
+	add_timer(&sport->lpuart_timer);
+}
+
+static void lpuart_request_dma(struct lpuart_port *sport)
+{
+	sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx");
+	if (IS_ERR(sport->dma_tx_chan)) {
+		dev_dbg_once(sport->port.dev,
+			     "DMA tx channel request failed, operating without tx DMA (%ld)\n",
+			     PTR_ERR(sport->dma_tx_chan));
+		sport->dma_tx_chan = NULL;
+	}
+
+	sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx");
+	if (IS_ERR(sport->dma_rx_chan)) {
+		dev_dbg_once(sport->port.dev,
+			     "DMA rx channel request failed, operating without rx DMA (%ld)\n",
+			     PTR_ERR(sport->dma_rx_chan));
+		sport->dma_rx_chan = NULL;
+	}
+}
+
+static void lpuart_tx_dma_startup(struct lpuart_port *sport)
+{
+	u32 uartbaud;
+	int ret;
+
+	if (uart_console(&sport->port))
+		goto err;
+
+	if (!sport->dma_tx_chan)
+		goto err;
+
+	ret = lpuart_dma_tx_request(&sport->port);
+	if (ret)
+		goto err;
+
+	init_waitqueue_head(&sport->dma_wait);
+	sport->lpuart_dma_tx_use = true;
+	if (lpuart_is_32(sport)) {
+		uartbaud = lpuart32_read(&sport->port, UARTBAUD);
+		lpuart32_write(&sport->port,
+			       uartbaud | UARTBAUD_TDMAE, UARTBAUD);
+	} else {
+		writeb(readb(sport->port.membase + UARTCR5) |
+		       UARTCR5_TDMAS, sport->port.membase + UARTCR5);
+	}
+
+	return;
+
+err:
+	sport->lpuart_dma_tx_use = false;
+}
+
+static void lpuart_rx_dma_startup(struct lpuart_port *sport)
+{
+	int ret;
+	unsigned char cr3;
+
+	if (uart_console(&sport->port))
+		goto err;
+
+	if (!sport->dma_rx_chan)
+		goto err;
+
+	/* set default Rx DMA timeout */
+	sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
+
+	ret = lpuart_start_rx_dma(sport);
+	if (ret)
+		goto err;
+
+	if (!sport->dma_rx_timeout)
+		sport->dma_rx_timeout = 1;
+
+	sport->lpuart_dma_rx_use = true;
+	rx_dma_timer_init(sport);
+
+	if (sport->port.has_sysrq && !lpuart_is_32(sport)) {
+		cr3 = readb(sport->port.membase + UARTCR3);
+		cr3 |= UARTCR3_FEIE;
+		writeb(cr3, sport->port.membase + UARTCR3);
+	}
+
+	return;
+
+err:
+	sport->lpuart_dma_rx_use = false;
+}
+
+static void lpuart_hw_setup(struct lpuart_port *sport)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	lpuart_setup_watermark_enable(sport);
+
+	lpuart_rx_dma_startup(sport);
+	lpuart_tx_dma_startup(sport);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static int lpuart_startup(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned char temp;
+
+	/* determine FIFO size and enable FIFO mode */
+	temp = readb(sport->port.membase + UARTPFIFO);
+
+	sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_TXSIZE_OFF) &
+					    UARTPFIFO_FIFOSIZE_MASK);
+	sport->port.fifosize = sport->txfifo_size;
+
+	sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) &
+					    UARTPFIFO_FIFOSIZE_MASK);
+
+	lpuart_request_dma(sport);
+	lpuart_hw_setup(sport);
+
+	return 0;
+}
+
+static void lpuart32_hw_disable(struct lpuart_port *sport)
+{
+	unsigned long temp;
+
+	temp = lpuart32_read(&sport->port, UARTCTRL);
+	temp &= ~(UARTCTRL_RIE | UARTCTRL_ILIE | UARTCTRL_RE |
+		  UARTCTRL_TIE | UARTCTRL_TE);
+	lpuart32_write(&sport->port, temp, UARTCTRL);
+}
+
+static void lpuart32_configure(struct lpuart_port *sport)
+{
+	unsigned long temp;
+
+	temp = lpuart32_read(&sport->port, UARTCTRL);
+	if (!sport->lpuart_dma_rx_use)
+		temp |= UARTCTRL_RIE | UARTCTRL_ILIE;
+	if (!sport->lpuart_dma_tx_use)
+		temp |= UARTCTRL_TIE;
+	lpuart32_write(&sport->port, temp, UARTCTRL);
+}
+
+static void lpuart32_hw_setup(struct lpuart_port *sport)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	lpuart32_hw_disable(sport);
+
+	lpuart_rx_dma_startup(sport);
+	lpuart_tx_dma_startup(sport);
+
+	lpuart32_setup_watermark_enable(sport);
+	lpuart32_configure(sport);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static int lpuart32_startup(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned long temp;
+
+	/* determine FIFO size */
+	temp = lpuart32_read(&sport->port, UARTFIFO);
+
+	sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_TXSIZE_OFF) &
+					    UARTFIFO_FIFOSIZE_MASK);
+	sport->port.fifosize = sport->txfifo_size;
+
+	sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) &
+					    UARTFIFO_FIFOSIZE_MASK);
+
+	/*
+	 * The LS1021A and LS1028A have a fixed FIFO depth of 16 words.
+	 * Although they support the RX/TXSIZE fields, their encoding is
+	 * different. Eg the reference manual states 0b101 is 16 words.
+	 */
+	if (is_layerscape_lpuart(sport)) {
+		sport->rxfifo_size = 16;
+		sport->txfifo_size = 16;
+		sport->port.fifosize = sport->txfifo_size;
+	}
+
+	lpuart_request_dma(sport);
+	lpuart32_hw_setup(sport);
+
+	return 0;
+}
+
+static void lpuart_dma_shutdown(struct lpuart_port *sport)
+{
+	if (sport->lpuart_dma_rx_use) {
+		lpuart_dma_rx_free(&sport->port);
+		sport->lpuart_dma_rx_use = false;
+	}
+
+	if (sport->lpuart_dma_tx_use) {
+		if (wait_event_interruptible_timeout(sport->dma_wait,
+			!sport->dma_tx_in_progress, msecs_to_jiffies(300)) <= 0) {
+			sport->dma_tx_in_progress = false;
+			dmaengine_terminate_sync(sport->dma_tx_chan);
+		}
+		sport->lpuart_dma_tx_use = false;
+	}
+
+	if (sport->dma_tx_chan)
+		dma_release_channel(sport->dma_tx_chan);
+	if (sport->dma_rx_chan)
+		dma_release_channel(sport->dma_rx_chan);
+}
+
+static void lpuart_shutdown(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned char temp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* disable Rx/Tx and interrupts */
+	temp = readb(port->membase + UARTCR2);
+	temp &= ~(UARTCR2_TE | UARTCR2_RE |
+			UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
+	writeb(temp, port->membase + UARTCR2);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	lpuart_dma_shutdown(sport);
+}
+
+static void lpuart32_shutdown(struct uart_port *port)
+{
+	struct lpuart_port *sport =
+		container_of(port, struct lpuart_port, port);
+	unsigned long temp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* clear status */
+	temp = lpuart32_read(&sport->port, UARTSTAT);
+	lpuart32_write(&sport->port, temp, UARTSTAT);
+
+	/* disable Rx/Tx DMA */
+	temp = lpuart32_read(port, UARTBAUD);
+	temp &= ~(UARTBAUD_TDMAE | UARTBAUD_RDMAE);
+	lpuart32_write(port, temp, UARTBAUD);
+
+	/* disable Rx/Tx and interrupts and break condition */
+	temp = lpuart32_read(port, UARTCTRL);
+	temp &= ~(UARTCTRL_TE | UARTCTRL_RE | UARTCTRL_ILIE |
+			UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE | UARTCTRL_SBK);
+	lpuart32_write(port, temp, UARTCTRL);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	lpuart_dma_shutdown(sport);
+}
+
+static void
+lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
+		   const struct ktermios *old)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned long flags;
+	unsigned char cr1, old_cr1, old_cr2, cr3, cr4, bdh, modem;
+	unsigned int  baud;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+	unsigned int sbr, brfa;
+
+	cr1 = old_cr1 = readb(sport->port.membase + UARTCR1);
+	old_cr2 = readb(sport->port.membase + UARTCR2);
+	cr3 = readb(sport->port.membase + UARTCR3);
+	cr4 = readb(sport->port.membase + UARTCR4);
+	bdh = readb(sport->port.membase + UARTBDH);
+	modem = readb(sport->port.membase + UARTMODEM);
+	/*
+	 * only support CS8 and CS7, and for CS7 must enable PE.
+	 * supported mode:
+	 *  - (7,e/o,1)
+	 *  - (8,n,1)
+	 *  - (8,m/s,1)
+	 *  - (8,e/o,1)
+	 */
+	while ((termios->c_cflag & CSIZE) != CS8 &&
+		(termios->c_cflag & CSIZE) != CS7) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS8 ||
+		(termios->c_cflag & CSIZE) == CS7)
+		cr1 = old_cr1 & ~UARTCR1_M;
+
+	if (termios->c_cflag & CMSPAR) {
+		if ((termios->c_cflag & CSIZE) != CS8) {
+			termios->c_cflag &= ~CSIZE;
+			termios->c_cflag |= CS8;
+		}
+		cr1 |= UARTCR1_M;
+	}
+
+	/*
+	 * When auto RS-485 RTS mode is enabled,
+	 * hardware flow control need to be disabled.
+	 */
+	if (sport->port.rs485.flags & SER_RS485_ENABLED)
+		termios->c_cflag &= ~CRTSCTS;
+
+	if (termios->c_cflag & CRTSCTS)
+		modem |= UARTMODEM_RXRTSE | UARTMODEM_TXCTSE;
+	else
+		modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
+
+	termios->c_cflag &= ~CSTOPB;
+
+	/* parity must be enabled when CS7 to match 8-bits format */
+	if ((termios->c_cflag & CSIZE) == CS7)
+		termios->c_cflag |= PARENB;
+
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & CMSPAR) {
+			cr1 &= ~UARTCR1_PE;
+			if (termios->c_cflag & PARODD)
+				cr3 |= UARTCR3_T8;
+			else
+				cr3 &= ~UARTCR3_T8;
+		} else {
+			cr1 |= UARTCR1_PE;
+			if ((termios->c_cflag & CSIZE) == CS8)
+				cr1 |= UARTCR1_M;
+			if (termios->c_cflag & PARODD)
+				cr1 |= UARTCR1_PT;
+			else
+				cr1 &= ~UARTCR1_PT;
+		}
+	} else {
+		cr1 &= ~UARTCR1_PE;
+	}
+
+	/* ask the core to calculate the divisor */
+	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
+
+	/*
+	 * Need to update the Ring buffer length according to the selected
+	 * baud rate and restart Rx DMA path.
+	 *
+	 * Since timer function acqures sport->port.lock, need to stop before
+	 * acquring same lock because otherwise del_timer_sync() can deadlock.
+	 */
+	if (old && sport->lpuart_dma_rx_use)
+		lpuart_dma_rx_free(&sport->port);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	sport->port.read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		sport->port.read_status_mask |= UARTSR1_FE | UARTSR1_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		sport->port.read_status_mask |= UARTSR1_FE;
+
+	/* characters to ignore */
+	sport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		sport->port.ignore_status_mask |= UARTSR1_PE;
+	if (termios->c_iflag & IGNBRK) {
+		sport->port.ignore_status_mask |= UARTSR1_FE;
+		/*
+		 * if we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			sport->port.ignore_status_mask |= UARTSR1_OR;
+	}
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* wait transmit engin complete */
+	lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC);
+
+	/* disable transmit and receive */
+	writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE),
+			sport->port.membase + UARTCR2);
+
+	sbr = sport->port.uartclk / (16 * baud);
+	brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud;
+	bdh &= ~UARTBDH_SBR_MASK;
+	bdh |= (sbr >> 8) & 0x1F;
+	cr4 &= ~UARTCR4_BRFA_MASK;
+	brfa &= UARTCR4_BRFA_MASK;
+	writeb(cr4 | brfa, sport->port.membase + UARTCR4);
+	writeb(bdh, sport->port.membase + UARTBDH);
+	writeb(sbr & 0xFF, sport->port.membase + UARTBDL);
+	writeb(cr3, sport->port.membase + UARTCR3);
+	writeb(cr1, sport->port.membase + UARTCR1);
+	writeb(modem, sport->port.membase + UARTMODEM);
+
+	/* restore control register */
+	writeb(old_cr2, sport->port.membase + UARTCR2);
+
+	if (old && sport->lpuart_dma_rx_use) {
+		if (!lpuart_start_rx_dma(sport))
+			rx_dma_timer_init(sport);
+		else
+			sport->lpuart_dma_rx_use = false;
+	}
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static void __lpuart32_serial_setbrg(struct uart_port *port,
+				     unsigned int baudrate, bool use_rx_dma,
+				     bool use_tx_dma)
+{
+	u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
+	u32 clk = port->uartclk;
+
+	/*
+	 * The idea is to use the best OSR (over-sampling rate) possible.
+	 * Note, OSR is typically hard-set to 16 in other LPUART instantiations.
+	 * Loop to find the best OSR value possible, one that generates minimum
+	 * baud_diff iterate through the rest of the supported values of OSR.
+	 *
+	 * Calculation Formula:
+	 *  Baud Rate = baud clock / ((OSR+1) × SBR)
+	 */
+	baud_diff = baudrate;
+	osr = 0;
+	sbr = 0;
+
+	for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) {
+		/* calculate the temporary sbr value  */
+		tmp_sbr = (clk / (baudrate * tmp_osr));
+		if (tmp_sbr == 0)
+			tmp_sbr = 1;
+
+		/*
+		 * calculate the baud rate difference based on the temporary
+		 * osr and sbr values
+		 */
+		tmp_diff = clk / (tmp_osr * tmp_sbr) - baudrate;
+
+		/* select best values between sbr and sbr+1 */
+		tmp = clk / (tmp_osr * (tmp_sbr + 1));
+		if (tmp_diff > (baudrate - tmp)) {
+			tmp_diff = baudrate - tmp;
+			tmp_sbr++;
+		}
+
+		if (tmp_sbr > UARTBAUD_SBR_MASK)
+			continue;
+
+		if (tmp_diff <= baud_diff) {
+			baud_diff = tmp_diff;
+			osr = tmp_osr;
+			sbr = tmp_sbr;
+
+			if (!baud_diff)
+				break;
+		}
+	}
+
+	/* handle buadrate outside acceptable rate */
+	if (baud_diff > ((baudrate / 100) * 3))
+		dev_warn(port->dev,
+			 "unacceptable baud rate difference of more than 3%%\n");
+
+	tmp = lpuart32_read(port, UARTBAUD);
+
+	if ((osr > 3) && (osr < 8))
+		tmp |= UARTBAUD_BOTHEDGE;
+
+	tmp &= ~(UARTBAUD_OSR_MASK << UARTBAUD_OSR_SHIFT);
+	tmp |= ((osr-1) & UARTBAUD_OSR_MASK) << UARTBAUD_OSR_SHIFT;
+
+	tmp &= ~UARTBAUD_SBR_MASK;
+	tmp |= sbr & UARTBAUD_SBR_MASK;
+
+	if (!use_rx_dma)
+		tmp &= ~UARTBAUD_RDMAE;
+	if (!use_tx_dma)
+		tmp &= ~UARTBAUD_TDMAE;
+
+	lpuart32_write(port, tmp, UARTBAUD);
+}
+
+static void lpuart32_serial_setbrg(struct lpuart_port *sport,
+				   unsigned int baudrate)
+{
+	__lpuart32_serial_setbrg(&sport->port, baudrate,
+				 sport->lpuart_dma_rx_use,
+				 sport->lpuart_dma_tx_use);
+}
+
+
+static void
+lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
+		     const struct ktermios *old)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned long flags;
+	unsigned long ctrl, old_ctrl, bd, modem;
+	unsigned int  baud;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+
+	ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL);
+	bd = lpuart32_read(&sport->port, UARTBAUD);
+	modem = lpuart32_read(&sport->port, UARTMODIR);
+	sport->is_cs7 = false;
+	/*
+	 * only support CS8 and CS7, and for CS7 must enable PE.
+	 * supported mode:
+	 *  - (7,e/o,1)
+	 *  - (8,n,1)
+	 *  - (8,m/s,1)
+	 *  - (8,e/o,1)
+	 */
+	while ((termios->c_cflag & CSIZE) != CS8 &&
+		(termios->c_cflag & CSIZE) != CS7) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS8 ||
+		(termios->c_cflag & CSIZE) == CS7)
+		ctrl = old_ctrl & ~UARTCTRL_M;
+
+	if (termios->c_cflag & CMSPAR) {
+		if ((termios->c_cflag & CSIZE) != CS8) {
+			termios->c_cflag &= ~CSIZE;
+			termios->c_cflag |= CS8;
+		}
+		ctrl |= UARTCTRL_M;
+	}
+
+	/*
+	 * When auto RS-485 RTS mode is enabled,
+	 * hardware flow control need to be disabled.
+	 */
+	if (sport->port.rs485.flags & SER_RS485_ENABLED)
+		termios->c_cflag &= ~CRTSCTS;
+
+	if (termios->c_cflag & CRTSCTS)
+		modem |= UARTMODIR_RXRTSE | UARTMODIR_TXCTSE;
+	else
+		modem &= ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
+
+	if (termios->c_cflag & CSTOPB)
+		bd |= UARTBAUD_SBNS;
+	else
+		bd &= ~UARTBAUD_SBNS;
+
+	/* parity must be enabled when CS7 to match 8-bits format */
+	if ((termios->c_cflag & CSIZE) == CS7)
+		termios->c_cflag |= PARENB;
+
+	if ((termios->c_cflag & PARENB)) {
+		if (termios->c_cflag & CMSPAR) {
+			ctrl &= ~UARTCTRL_PE;
+			ctrl |= UARTCTRL_M;
+		} else {
+			ctrl |= UARTCTRL_PE;
+			if ((termios->c_cflag & CSIZE) == CS8)
+				ctrl |= UARTCTRL_M;
+			if (termios->c_cflag & PARODD)
+				ctrl |= UARTCTRL_PT;
+			else
+				ctrl &= ~UARTCTRL_PT;
+		}
+	} else {
+		ctrl &= ~UARTCTRL_PE;
+	}
+
+	/* ask the core to calculate the divisor */
+	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4);
+
+	/*
+	 * Need to update the Ring buffer length according to the selected
+	 * baud rate and restart Rx DMA path.
+	 *
+	 * Since timer function acqures sport->port.lock, need to stop before
+	 * acquring same lock because otherwise del_timer_sync() can deadlock.
+	 */
+	if (old && sport->lpuart_dma_rx_use)
+		lpuart_dma_rx_free(&sport->port);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	sport->port.read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		sport->port.read_status_mask |= UARTSTAT_FE | UARTSTAT_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		sport->port.read_status_mask |= UARTSTAT_FE;
+
+	/* characters to ignore */
+	sport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		sport->port.ignore_status_mask |= UARTSTAT_PE;
+	if (termios->c_iflag & IGNBRK) {
+		sport->port.ignore_status_mask |= UARTSTAT_FE;
+		/*
+		 * if we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			sport->port.ignore_status_mask |= UARTSTAT_OR;
+	}
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * LPUART Transmission Complete Flag may never be set while queuing a break
+	 * character, so skip waiting for transmission complete when UARTCTRL_SBK is
+	 * asserted.
+	 */
+	if (!(old_ctrl & UARTCTRL_SBK)) {
+		lpuart32_write(&sport->port, 0, UARTMODIR);
+		lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);
+	}
+
+	/* disable transmit and receive */
+	lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE),
+		       UARTCTRL);
+
+	lpuart32_write(&sport->port, bd, UARTBAUD);
+	lpuart32_serial_setbrg(sport, baud);
+	lpuart32_write(&sport->port, modem, UARTMODIR);
+	lpuart32_write(&sport->port, ctrl, UARTCTRL);
+	/* restore control register */
+
+	if ((ctrl & (UARTCTRL_PE | UARTCTRL_M)) == UARTCTRL_PE)
+		sport->is_cs7 = true;
+
+	if (old && sport->lpuart_dma_rx_use) {
+		if (!lpuart_start_rx_dma(sport))
+			rx_dma_timer_init(sport);
+		else
+			sport->lpuart_dma_rx_use = false;
+	}
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static const char *lpuart_type(struct uart_port *port)
+{
+	return "FSL_LPUART";
+}
+
+static void lpuart_release_port(struct uart_port *port)
+{
+	/* nothing to do */
+}
+
+static int lpuart_request_port(struct uart_port *port)
+{
+	return  0;
+}
+
+/* configure/autoconfigure the port */
+static void lpuart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_LPUART;
+}
+
+static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART)
+		ret = -EINVAL;
+	if (port->irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->io_type != UPIO_MEM)
+		ret = -EINVAL;
+	if (port->uartclk / 16 != ser->baud_base)
+		ret = -EINVAL;
+	if (port->iobase != ser->port)
+		ret = -EINVAL;
+	if (ser->hub6 != 0)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops lpuart_pops = {
+	.tx_empty	= lpuart_tx_empty,
+	.set_mctrl	= lpuart_set_mctrl,
+	.get_mctrl	= lpuart_get_mctrl,
+	.stop_tx	= lpuart_stop_tx,
+	.start_tx	= lpuart_start_tx,
+	.stop_rx	= lpuart_stop_rx,
+	.break_ctl	= lpuart_break_ctl,
+	.startup	= lpuart_startup,
+	.shutdown	= lpuart_shutdown,
+	.set_termios	= lpuart_set_termios,
+	.pm		= lpuart_uart_pm,
+	.type		= lpuart_type,
+	.request_port	= lpuart_request_port,
+	.release_port	= lpuart_release_port,
+	.config_port	= lpuart_config_port,
+	.verify_port	= lpuart_verify_port,
+	.flush_buffer	= lpuart_flush_buffer,
+#if defined(CONFIG_CONSOLE_POLL)
+	.poll_init	= lpuart_poll_init,
+	.poll_get_char	= lpuart_poll_get_char,
+	.poll_put_char	= lpuart_poll_put_char,
+#endif
+};
+
+static const struct uart_ops lpuart32_pops = {
+	.tx_empty	= lpuart32_tx_empty,
+	.set_mctrl	= lpuart32_set_mctrl,
+	.get_mctrl	= lpuart32_get_mctrl,
+	.stop_tx	= lpuart32_stop_tx,
+	.start_tx	= lpuart32_start_tx,
+	.stop_rx	= lpuart32_stop_rx,
+	.break_ctl	= lpuart32_break_ctl,
+	.startup	= lpuart32_startup,
+	.shutdown	= lpuart32_shutdown,
+	.set_termios	= lpuart32_set_termios,
+	.pm		= lpuart_uart_pm,
+	.type		= lpuart_type,
+	.request_port	= lpuart_request_port,
+	.release_port	= lpuart_release_port,
+	.config_port	= lpuart_config_port,
+	.verify_port	= lpuart_verify_port,
+	.flush_buffer	= lpuart_flush_buffer,
+#if defined(CONFIG_CONSOLE_POLL)
+	.poll_init	= lpuart32_poll_init,
+	.poll_get_char	= lpuart32_poll_get_char,
+	.poll_put_char	= lpuart32_poll_put_char,
+#endif
+};
+
+static struct lpuart_port *lpuart_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE
+static void lpuart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE);
+	writeb(ch, port->membase + UARTDR);
+}
+
+static void lpuart32_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE);
+	lpuart32_write(port, ch, UARTDATA);
+}
+
+static void
+lpuart_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct lpuart_port *sport = lpuart_ports[co->index];
+	unsigned char  old_cr2, cr2;
+	unsigned long flags;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&sport->port.lock, flags);
+	else
+		spin_lock_irqsave(&sport->port.lock, flags);
+
+	/* first save CR2 and then disable interrupts */
+	cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
+	cr2 |= UARTCR2_TE | UARTCR2_RE;
+	cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
+	writeb(cr2, sport->port.membase + UARTCR2);
+
+	uart_console_write(&sport->port, s, count, lpuart_console_putchar);
+
+	/* wait for transmitter finish complete and restore CR2 */
+	lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC);
+
+	writeb(old_cr2, sport->port.membase + UARTCR2);
+
+	if (locked)
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static void
+lpuart32_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct lpuart_port *sport = lpuart_ports[co->index];
+	unsigned long  old_cr, cr;
+	unsigned long flags;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&sport->port.lock, flags);
+	else
+		spin_lock_irqsave(&sport->port.lock, flags);
+
+	/* first save CR2 and then disable interrupts */
+	cr = old_cr = lpuart32_read(&sport->port, UARTCTRL);
+	cr |= UARTCTRL_TE | UARTCTRL_RE;
+	cr &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
+	lpuart32_write(&sport->port, cr, UARTCTRL);
+
+	uart_console_write(&sport->port, s, count, lpuart32_console_putchar);
+
+	/* wait for transmitter finish complete and restore CR2 */
+	lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);
+
+	lpuart32_write(&sport->port, old_cr, UARTCTRL);
+
+	if (locked)
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+/*
+ * if the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+lpuart_console_get_options(struct lpuart_port *sport, int *baud,
+			   int *parity, int *bits)
+{
+	unsigned char cr, bdh, bdl, brfa;
+	unsigned int sbr, uartclk, baud_raw;
+
+	cr = readb(sport->port.membase + UARTCR2);
+	cr &= UARTCR2_TE | UARTCR2_RE;
+	if (!cr)
+		return;
+
+	/* ok, the port was enabled */
+
+	cr = readb(sport->port.membase + UARTCR1);
+
+	*parity = 'n';
+	if (cr & UARTCR1_PE) {
+		if (cr & UARTCR1_PT)
+			*parity = 'o';
+		else
+			*parity = 'e';
+	}
+
+	if (cr & UARTCR1_M)
+		*bits = 9;
+	else
+		*bits = 8;
+
+	bdh = readb(sport->port.membase + UARTBDH);
+	bdh &= UARTBDH_SBR_MASK;
+	bdl = readb(sport->port.membase + UARTBDL);
+	sbr = bdh;
+	sbr <<= 8;
+	sbr |= bdl;
+	brfa = readb(sport->port.membase + UARTCR4);
+	brfa &= UARTCR4_BRFA_MASK;
+
+	uartclk = lpuart_get_baud_clk_rate(sport);
+	/*
+	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
+	 */
+	baud_raw = uartclk / (16 * (sbr + brfa / 32));
+
+	if (*baud != baud_raw)
+		dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate"
+				"from %d to %d\n", baud_raw, *baud);
+}
+
+static void __init
+lpuart32_console_get_options(struct lpuart_port *sport, int *baud,
+			   int *parity, int *bits)
+{
+	unsigned long cr, bd;
+	unsigned int sbr, uartclk, baud_raw;
+
+	cr = lpuart32_read(&sport->port, UARTCTRL);
+	cr &= UARTCTRL_TE | UARTCTRL_RE;
+	if (!cr)
+		return;
+
+	/* ok, the port was enabled */
+
+	cr = lpuart32_read(&sport->port, UARTCTRL);
+
+	*parity = 'n';
+	if (cr & UARTCTRL_PE) {
+		if (cr & UARTCTRL_PT)
+			*parity = 'o';
+		else
+			*parity = 'e';
+	}
+
+	if (cr & UARTCTRL_M)
+		*bits = 9;
+	else
+		*bits = 8;
+
+	bd = lpuart32_read(&sport->port, UARTBAUD);
+	bd &= UARTBAUD_SBR_MASK;
+	if (!bd)
+		return;
+
+	sbr = bd;
+	uartclk = lpuart_get_baud_clk_rate(sport);
+	/*
+	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
+	 */
+	baud_raw = uartclk / (16 * sbr);
+
+	if (*baud != baud_raw)
+		dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate"
+				"from %d to %d\n", baud_raw, *baud);
+}
+
+static int __init lpuart_console_setup(struct console *co, char *options)
+{
+	struct lpuart_port *sport;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports))
+		co->index = 0;
+
+	sport = lpuart_ports[co->index];
+	if (sport == NULL)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		if (lpuart_is_32(sport))
+			lpuart32_console_get_options(sport, &baud, &parity, &bits);
+		else
+			lpuart_console_get_options(sport, &baud, &parity, &bits);
+
+	if (lpuart_is_32(sport))
+		lpuart32_setup_watermark(sport);
+	else
+		lpuart_setup_watermark(sport);
+
+	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver lpuart_reg;
+static struct console lpuart_console = {
+	.name		= DEV_NAME,
+	.write		= lpuart_console_write,
+	.device		= uart_console_device,
+	.setup		= lpuart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &lpuart_reg,
+};
+
+static struct console lpuart32_console = {
+	.name		= DEV_NAME,
+	.write		= lpuart32_console_write,
+	.device		= uart_console_device,
+	.setup		= lpuart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &lpuart_reg,
+};
+
+static void lpuart_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, lpuart_console_putchar);
+}
+
+static void lpuart32_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, lpuart32_console_putchar);
+}
+
+static int __init lpuart_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = lpuart_early_write;
+	return 0;
+}
+
+static int __init lpuart32_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	if (device->port.iotype != UPIO_MEM32)
+		device->port.iotype = UPIO_MEM32BE;
+
+	device->con->write = lpuart32_early_write;
+	return 0;
+}
+
+static int __init ls1028a_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	u32 cr;
+
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+	device->con->write = lpuart32_early_write;
+
+	/* set the baudrate */
+	if (device->port.uartclk && device->baud)
+		__lpuart32_serial_setbrg(&device->port, device->baud,
+					 false, false);
+
+	/* enable transmitter */
+	cr = lpuart32_read(&device->port, UARTCTRL);
+	cr |= UARTCTRL_TE;
+	lpuart32_write(&device->port, cr, UARTCTRL);
+
+	return 0;
+}
+
+static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device,
+						   const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+	device->port.membase += IMX_REG_OFF;
+	device->con->write = lpuart32_early_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8ulp-lpuart", lpuart32_imx_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,imxrt1050-lpuart", lpuart32_imx_early_console_setup);
+EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
+EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
+
+#define LPUART_CONSOLE	(&lpuart_console)
+#define LPUART32_CONSOLE	(&lpuart32_console)
+#else
+#define LPUART_CONSOLE	NULL
+#define LPUART32_CONSOLE	NULL
+#endif
+
+static struct uart_driver lpuart_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= DEV_NAME,
+	.nr		= ARRAY_SIZE(lpuart_ports),
+	.cons		= LPUART_CONSOLE,
+};
+
+static const struct serial_rs485 lpuart_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
+	/* delay_rts_* and RX_DURING_TX are not supported */
+};
+
+static int lpuart_global_reset(struct lpuart_port *sport)
+{
+	struct uart_port *port = &sport->port;
+	void __iomem *global_addr;
+	unsigned long ctrl, bd;
+	unsigned int val = 0;
+	int ret;
+
+	ret = clk_prepare_enable(sport->ipg_clk);
+	if (ret) {
+		dev_err(sport->port.dev, "failed to enable uart ipg clk: %d\n", ret);
+		return ret;
+	}
+
+	if (is_imx7ulp_lpuart(sport) || is_imx8ulp_lpuart(sport) || is_imx8qxp_lpuart(sport)) {
+		/*
+		 * If the transmitter is used by earlycon, wait for transmit engine to
+		 * complete and then reset.
+		 */
+		ctrl = lpuart32_read(port, UARTCTRL);
+		if (ctrl & UARTCTRL_TE) {
+			bd = lpuart32_read(&sport->port, UARTBAUD);
+			if (read_poll_timeout(lpuart32_tx_empty, val, val, 1, 100000, false,
+					      port)) {
+				dev_warn(sport->port.dev,
+					 "timeout waiting for transmit engine to complete\n");
+				clk_disable_unprepare(sport->ipg_clk);
+				return 0;
+			}
+		}
+
+		global_addr = port->membase + UART_GLOBAL - IMX_REG_OFF;
+		writel(UART_GLOBAL_RST, global_addr);
+		usleep_range(GLOBAL_RST_MIN_US, GLOBAL_RST_MAX_US);
+		writel(0, global_addr);
+		usleep_range(GLOBAL_RST_MIN_US, GLOBAL_RST_MAX_US);
+
+		/* Recover the transmitter for earlycon. */
+		if (ctrl & UARTCTRL_TE) {
+			lpuart32_write(port, bd, UARTBAUD);
+			lpuart32_write(port, ctrl, UARTCTRL);
+		}
+	}
+
+	clk_disable_unprepare(sport->ipg_clk);
+	return 0;
+}
+
+static int lpuart_probe(struct platform_device *pdev)
+{
+	const struct lpuart_soc_data *sdata = of_device_get_match_data(&pdev->dev);
+	struct device_node *np = pdev->dev.of_node;
+	struct lpuart_port *sport;
+	struct resource *res;
+	irq_handler_t handler;
+	int ret;
+
+	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	sport->port.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(sport->port.membase))
+		return PTR_ERR(sport->port.membase);
+
+	sport->port.membase += sdata->reg_off;
+	sport->port.mapbase = res->start + sdata->reg_off;
+	sport->port.dev = &pdev->dev;
+	sport->port.type = PORT_LPUART;
+	sport->devtype = sdata->devtype;
+	sport->rx_watermark = sdata->rx_watermark;
+	sport->dma_idle_int = is_imx7ulp_lpuart(sport) || is_imx8ulp_lpuart(sport) ||
+			      is_imx8qxp_lpuart(sport);
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	sport->port.irq = ret;
+	sport->port.iotype = sdata->iotype;
+	if (lpuart_is_32(sport))
+		sport->port.ops = &lpuart32_pops;
+	else
+		sport->port.ops = &lpuart_pops;
+	sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LPUART_CONSOLE);
+	sport->port.flags = UPF_BOOT_AUTOCONF;
+
+	if (lpuart_is_32(sport))
+		sport->port.rs485_config = lpuart32_config_rs485;
+	else
+		sport->port.rs485_config = lpuart_config_rs485;
+	sport->port.rs485_supported = lpuart_rs485_supported;
+
+	sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(sport->ipg_clk)) {
+		ret = PTR_ERR(sport->ipg_clk);
+		dev_err(&pdev->dev, "failed to get uart ipg clk: %d\n", ret);
+		return ret;
+	}
+
+	sport->baud_clk = NULL;
+	if (is_imx8qxp_lpuart(sport)) {
+		sport->baud_clk = devm_clk_get(&pdev->dev, "baud");
+		if (IS_ERR(sport->baud_clk)) {
+			ret = PTR_ERR(sport->baud_clk);
+			dev_err(&pdev->dev, "failed to get uart baud clk: %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+		return ret;
+	}
+	if (ret >= ARRAY_SIZE(lpuart_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n", ret);
+		return -EINVAL;
+	}
+	sport->port.line = ret;
+
+	ret = lpuart_enable_clks(sport);
+	if (ret)
+		return ret;
+	sport->port.uartclk = lpuart_get_baud_clk_rate(sport);
+
+	lpuart_ports[sport->port.line] = sport;
+
+	platform_set_drvdata(pdev, &sport->port);
+
+	if (lpuart_is_32(sport)) {
+		lpuart_reg.cons = LPUART32_CONSOLE;
+		handler = lpuart32_int;
+	} else {
+		lpuart_reg.cons = LPUART_CONSOLE;
+		handler = lpuart_int;
+	}
+
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = lpuart_global_reset(sport);
+	if (ret)
+		goto failed_reset;
+
+	ret = uart_get_rs485_mode(&sport->port);
+	if (ret)
+		goto failed_get_rs485;
+
+	ret = uart_add_one_port(&lpuart_reg, &sport->port);
+	if (ret)
+		goto failed_attach_port;
+
+	ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0,
+				DRIVER_NAME, sport);
+	if (ret)
+		goto failed_irq_request;
+
+	return 0;
+
+failed_irq_request:
+	uart_remove_one_port(&lpuart_reg, &sport->port);
+failed_attach_port:
+failed_get_rs485:
+failed_reset:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	lpuart_disable_clks(sport);
+	return ret;
+}
+
+static int lpuart_remove(struct platform_device *pdev)
+{
+	struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&lpuart_reg, &sport->port);
+
+	lpuart_disable_clks(sport);
+
+	if (sport->dma_tx_chan)
+		dma_release_channel(sport->dma_tx_chan);
+
+	if (sport->dma_rx_chan)
+		dma_release_channel(sport->dma_rx_chan);
+
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	return 0;
+}
+
+static int lpuart_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+	lpuart_disable_clks(sport);
+
+	return 0;
+};
+
+static int lpuart_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+	return lpuart_enable_clks(sport);
+};
+
+static void serial_lpuart_enable_wakeup(struct lpuart_port *sport, bool on)
+{
+	unsigned int val, baud;
+
+	if (lpuart_is_32(sport)) {
+		val = lpuart32_read(&sport->port, UARTCTRL);
+		baud = lpuart32_read(&sport->port, UARTBAUD);
+		if (on) {
+			/* set rx_watermark to 0 in wakeup source mode */
+			lpuart32_write(&sport->port, 0, UARTWATER);
+			val |= UARTCTRL_RIE;
+			/* clear RXEDGIF flag before enable RXEDGIE interrupt */
+			lpuart32_write(&sport->port, UARTSTAT_RXEDGIF, UARTSTAT);
+			baud |= UARTBAUD_RXEDGIE;
+		} else {
+			val &= ~UARTCTRL_RIE;
+			baud &= ~UARTBAUD_RXEDGIE;
+		}
+		lpuart32_write(&sport->port, val, UARTCTRL);
+		lpuart32_write(&sport->port, baud, UARTBAUD);
+	} else {
+		val = readb(sport->port.membase + UARTCR2);
+		if (on)
+			val |= UARTCR2_RIE;
+		else
+			val &= ~UARTCR2_RIE;
+		writeb(val, sport->port.membase + UARTCR2);
+	}
+}
+
+static bool lpuart_uport_is_active(struct lpuart_port *sport)
+{
+	struct tty_port *port = &sport->port.state->port;
+	struct tty_struct *tty;
+	struct device *tty_dev;
+	int may_wake = 0;
+
+	tty = tty_port_tty_get(port);
+	if (tty) {
+		tty_dev = tty->dev;
+		may_wake = tty_dev && device_may_wakeup(tty_dev);
+		tty_kref_put(tty);
+	}
+
+	if ((tty_port_initialized(port) && may_wake) ||
+	    (!console_suspend_enabled && uart_console(&sport->port)))
+		return true;
+
+	return false;
+}
+
+static int lpuart_suspend_noirq(struct device *dev)
+{
+	struct lpuart_port *sport = dev_get_drvdata(dev);
+	bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
+
+	if (lpuart_uport_is_active(sport))
+		serial_lpuart_enable_wakeup(sport, !!irq_wake);
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int lpuart_resume_noirq(struct device *dev)
+{
+	struct lpuart_port *sport = dev_get_drvdata(dev);
+	unsigned int val;
+
+	pinctrl_pm_select_default_state(dev);
+
+	if (lpuart_uport_is_active(sport)) {
+		serial_lpuart_enable_wakeup(sport, false);
+
+		/* clear the wakeup flags */
+		if (lpuart_is_32(sport)) {
+			val = lpuart32_read(&sport->port, UARTSTAT);
+			lpuart32_write(&sport->port, val, UARTSTAT);
+		}
+	}
+
+	return 0;
+}
+
+static int lpuart_suspend(struct device *dev)
+{
+	struct lpuart_port *sport = dev_get_drvdata(dev);
+	unsigned long temp, flags;
+
+	uart_suspend_port(&lpuart_reg, &sport->port);
+
+	if (lpuart_uport_is_active(sport)) {
+		spin_lock_irqsave(&sport->port.lock, flags);
+		if (lpuart_is_32(sport)) {
+			/* disable Rx/Tx and interrupts */
+			temp = lpuart32_read(&sport->port, UARTCTRL);
+			temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
+			lpuart32_write(&sport->port, temp, UARTCTRL);
+		} else {
+			/* disable Rx/Tx and interrupts */
+			temp = readb(sport->port.membase + UARTCR2);
+			temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
+			writeb(temp, sport->port.membase + UARTCR2);
+		}
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+
+		if (sport->lpuart_dma_rx_use) {
+			/*
+			 * EDMA driver during suspend will forcefully release any
+			 * non-idle DMA channels. If port wakeup is enabled or if port
+			 * is console port or 'no_console_suspend' is set the Rx DMA
+			 * cannot resume as expected, hence gracefully release the
+			 * Rx DMA path before suspend and start Rx DMA path on resume.
+			 */
+			lpuart_dma_rx_free(&sport->port);
+
+			/* Disable Rx DMA to use UART port as wakeup source */
+			spin_lock_irqsave(&sport->port.lock, flags);
+			if (lpuart_is_32(sport)) {
+				temp = lpuart32_read(&sport->port, UARTBAUD);
+				lpuart32_write(&sport->port, temp & ~UARTBAUD_RDMAE,
+					       UARTBAUD);
+			} else {
+				writeb(readb(sport->port.membase + UARTCR5) &
+				       ~UARTCR5_RDMAS, sport->port.membase + UARTCR5);
+			}
+			spin_unlock_irqrestore(&sport->port.lock, flags);
+		}
+
+		if (sport->lpuart_dma_tx_use) {
+			spin_lock_irqsave(&sport->port.lock, flags);
+			if (lpuart_is_32(sport)) {
+				temp = lpuart32_read(&sport->port, UARTBAUD);
+				temp &= ~UARTBAUD_TDMAE;
+				lpuart32_write(&sport->port, temp, UARTBAUD);
+			} else {
+				temp = readb(sport->port.membase + UARTCR5);
+				temp &= ~UARTCR5_TDMAS;
+				writeb(temp, sport->port.membase + UARTCR5);
+			}
+			spin_unlock_irqrestore(&sport->port.lock, flags);
+			sport->dma_tx_in_progress = false;
+			dmaengine_terminate_sync(sport->dma_tx_chan);
+		}
+	} else if (pm_runtime_active(sport->port.dev)) {
+		lpuart_disable_clks(sport);
+		pm_runtime_disable(sport->port.dev);
+		pm_runtime_set_suspended(sport->port.dev);
+	}
+
+	return 0;
+}
+
+static void lpuart_console_fixup(struct lpuart_port *sport)
+{
+	struct tty_port *port = &sport->port.state->port;
+	struct uart_port *uport = &sport->port;
+	struct ktermios termios;
+
+	/* i.MX7ULP enter VLLS mode that lpuart module power off and registers
+	 * all lost no matter the port is wakeup source.
+	 * For console port, console baud rate setting lost and print messy
+	 * log when enable the console port as wakeup source. To avoid the
+	 * issue happen, user should not enable uart port as wakeup source
+	 * in VLLS mode, or restore console setting here.
+	 */
+	if (is_imx7ulp_lpuart(sport) && lpuart_uport_is_active(sport) &&
+	    console_suspend_enabled && uart_console(&sport->port)) {
+
+		mutex_lock(&port->mutex);
+		memset(&termios, 0, sizeof(struct ktermios));
+		termios.c_cflag = uport->cons->cflag;
+		if (port->tty && termios.c_cflag == 0)
+			termios = port->tty->termios;
+		uport->ops->set_termios(uport, &termios, NULL);
+		mutex_unlock(&port->mutex);
+	}
+}
+
+static int lpuart_resume(struct device *dev)
+{
+	struct lpuart_port *sport = dev_get_drvdata(dev);
+	int ret;
+
+	if (lpuart_uport_is_active(sport)) {
+		if (lpuart_is_32(sport))
+			lpuart32_hw_setup(sport);
+		else
+			lpuart_hw_setup(sport);
+	} else if (pm_runtime_active(sport->port.dev)) {
+		ret = lpuart_enable_clks(sport);
+		if (ret)
+			return ret;
+		pm_runtime_set_active(sport->port.dev);
+		pm_runtime_enable(sport->port.dev);
+	}
+
+	lpuart_console_fixup(sport);
+	uart_resume_port(&lpuart_reg, &sport->port);
+
+	return 0;
+}
+
+static const struct dev_pm_ops lpuart_pm_ops = {
+	RUNTIME_PM_OPS(lpuart_runtime_suspend,
+			   lpuart_runtime_resume, NULL)
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(lpuart_suspend_noirq,
+				      lpuart_resume_noirq)
+	SYSTEM_SLEEP_PM_OPS(lpuart_suspend, lpuart_resume)
+};
+
+static struct platform_driver lpuart_driver = {
+	.probe		= lpuart_probe,
+	.remove		= lpuart_remove,
+	.driver		= {
+		.name	= "fsl-lpuart",
+		.of_match_table = lpuart_dt_ids,
+		.pm	= pm_ptr(&lpuart_pm_ops),
+	},
+};
+
+static int __init lpuart_serial_init(void)
+{
+	int ret = uart_register_driver(&lpuart_reg);
+
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&lpuart_driver);
+	if (ret)
+		uart_unregister_driver(&lpuart_reg);
+
+	return ret;
+}
+
+static void __exit lpuart_serial_exit(void)
+{
+	platform_driver_unregister(&lpuart_driver);
+	uart_unregister_driver(&lpuart_reg);
+}
+
+module_init(lpuart_serial_init);
+module_exit(lpuart_serial_exit);
+
+MODULE_DESCRIPTION("Freescale lpuart serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/icom.c b/drivers/tty/serial/icom.c
new file mode 100644
index 000000000..819f957b6
--- /dev/null
+++ b/drivers/tty/serial/icom.c
@@ -0,0 +1,1876 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+  * icom.c
+  *
+  * Copyright (C) 2001 IBM Corporation. All rights reserved.
+  *
+  * Serial device driver.
+  *
+  * Based on code from serial.c
+  */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/termios.h>
+#include <linux/fs.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/vmalloc.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/kref.h>
+#include <linux/firmware.h>
+#include <linux/bitops.h>
+
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <linux/uaccess.h>
+
+/*#define ICOM_TRACE		 enable port trace capabilities */
+
+#define ICOM_DRIVER_NAME "icom"
+#define NR_PORTS	       128
+
+static const unsigned int icom_acfg_baud[] = {
+	300,
+	600,
+	900,
+	1200,
+	1800,
+	2400,
+	3600,
+	4800,
+	7200,
+	9600,
+	14400,
+	19200,
+	28800,
+	38400,
+	57600,
+	76800,
+	115200,
+	153600,
+	230400,
+	307200,
+	460800,
+};
+#define BAUD_TABLE_LIMIT	(ARRAY_SIZE(icom_acfg_baud) - 1)
+
+struct icom_regs {
+	u32 control;		/* Adapter Control Register     */
+	u32 interrupt;		/* Adapter Interrupt Register   */
+	u32 int_mask;		/* Adapter Interrupt Mask Reg   */
+	u32 int_pri;		/* Adapter Interrupt Priority r */
+	u32 int_reg_b;		/* Adapter non-masked Interrupt */
+	u32 resvd01;
+	u32 resvd02;
+	u32 resvd03;
+	u32 control_2;		/* Adapter Control Register 2   */
+	u32 interrupt_2;	/* Adapter Interrupt Register 2 */
+	u32 int_mask_2;		/* Adapter Interrupt Mask 2     */
+	u32 int_pri_2;		/* Adapter Interrupt Prior 2    */
+	u32 int_reg_2b;		/* Adapter non-masked 2         */
+};
+
+struct func_dram {
+	u32 reserved[108];	/* 0-1B0   reserved by personality code */
+	u32 RcvStatusAddr;	/* 1B0-1B3 Status Address for Next rcv */
+	u8 RcvStnAddr;		/* 1B4     Receive Station Addr */
+	u8 IdleState;		/* 1B5     Idle State */
+	u8 IdleMonitor;		/* 1B6     Idle Monitor */
+	u8 FlagFillIdleTimer;	/* 1B7     Flag Fill Idle Timer */
+	u32 XmitStatusAddr;	/* 1B8-1BB Transmit Status Address */
+	u8 StartXmitCmd;	/* 1BC     Start Xmit Command */
+	u8 HDLCConfigReg;	/* 1BD     Reserved */
+	u8 CauseCode;		/* 1BE     Cause code for fatal error */
+	u8 xchar;		/* 1BF     High priority send */
+	u32 reserved3;		/* 1C0-1C3 Reserved */
+	u8 PrevCmdReg;		/* 1C4     Reserved */
+	u8 CmdReg;		/* 1C5     Command Register */
+	u8 async_config2;	/* 1C6     Async Config Byte 2 */
+	u8 async_config3;	/* 1C7     Async Config Byte 3 */
+	u8 dce_resvd[20];	/* 1C8-1DB DCE Rsvd           */
+	u8 dce_resvd21;		/* 1DC     DCE Rsvd (21st byte */
+	u8 misc_flags;		/* 1DD     misc flags         */
+#define V2_HARDWARE     0x40
+#define ICOM_HDW_ACTIVE 0x01
+	u8 call_length;		/* 1DE     Phone #/CFI buff ln */
+	u8 call_length2;	/* 1DF     Upper byte (unused) */
+	u32 call_addr;		/* 1E0-1E3 Phn #/CFI buff addr */
+	u16 timer_value;	/* 1E4-1E5 general timer value */
+	u8 timer_command;	/* 1E6     general timer cmd  */
+	u8 dce_command;		/* 1E7     dce command reg    */
+	u8 dce_cmd_status;	/* 1E8     dce command stat   */
+	u8 x21_r1_ioff;		/* 1E9     dce ready counter  */
+	u8 x21_r0_ioff;		/* 1EA     dce not ready ctr  */
+	u8 x21_ralt_ioff;	/* 1EB     dce CNR counter    */
+	u8 x21_r1_ion;		/* 1EC     dce ready I on ctr */
+	u8 rsvd_ier;		/* 1ED     Rsvd for IER (if ne */
+	u8 ier;			/* 1EE     Interrupt Enable   */
+	u8 isr;			/* 1EF     Input Signal Reg   */
+	u8 osr;			/* 1F0     Output Signal Reg  */
+	u8 reset;		/* 1F1     Reset/Reload Reg   */
+	u8 disable;		/* 1F2     Disable Reg        */
+	u8 sync;		/* 1F3     Sync Reg           */
+	u8 error_stat;		/* 1F4     Error Status       */
+	u8 cable_id;		/* 1F5     Cable ID           */
+	u8 cs_length;		/* 1F6     CS Load Length     */
+	u8 mac_length;		/* 1F7     Mac Load Length    */
+	u32 cs_load_addr;	/* 1F8-1FB Call Load PCI Addr */
+	u32 mac_load_addr;	/* 1FC-1FF Mac Load PCI Addr  */
+};
+
+/*
+ * adapter defines and structures
+ */
+#define ICOM_CONTROL_START_A         0x00000008
+#define ICOM_CONTROL_STOP_A          0x00000004
+#define ICOM_CONTROL_START_B         0x00000002
+#define ICOM_CONTROL_STOP_B          0x00000001
+#define ICOM_CONTROL_START_C         0x00000008
+#define ICOM_CONTROL_STOP_C          0x00000004
+#define ICOM_CONTROL_START_D         0x00000002
+#define ICOM_CONTROL_STOP_D          0x00000001
+#define ICOM_IRAM_OFFSET             0x1000
+#define ICOM_IRAM_SIZE               0x0C00
+#define ICOM_DCE_IRAM_OFFSET         0x0A00
+#define ICOM_CABLE_ID_VALID          0x01
+#define ICOM_CABLE_ID_MASK           0xF0
+#define ICOM_DISABLE                 0x80
+#define CMD_XMIT_RCV_ENABLE          0xC0
+#define CMD_XMIT_ENABLE              0x40
+#define CMD_RCV_DISABLE              0x00
+#define CMD_RCV_ENABLE               0x80
+#define CMD_RESTART                  0x01
+#define CMD_HOLD_XMIT                0x02
+#define CMD_SND_BREAK                0x04
+#define RS232_CABLE                  0x06
+#define V24_CABLE                    0x0E
+#define V35_CABLE                    0x0C
+#define V36_CABLE                    0x02
+#define NO_CABLE                     0x00
+#define START_DOWNLOAD               0x80
+#define ICOM_INT_MASK_PRC_A          0x00003FFF
+#define ICOM_INT_MASK_PRC_B          0x3FFF0000
+#define ICOM_INT_MASK_PRC_C          0x00003FFF
+#define ICOM_INT_MASK_PRC_D          0x3FFF0000
+#define INT_RCV_COMPLETED            0x1000
+#define INT_XMIT_COMPLETED           0x2000
+#define INT_IDLE_DETECT              0x0800
+#define INT_RCV_DISABLED             0x0400
+#define INT_XMIT_DISABLED            0x0200
+#define INT_RCV_XMIT_SHUTDOWN        0x0100
+#define INT_FATAL_ERROR              0x0080
+#define INT_CABLE_PULL               0x0020
+#define INT_SIGNAL_CHANGE            0x0010
+#define HDLC_PPP_PURE_ASYNC          0x02
+#define HDLC_FF_FILL                 0x00
+#define HDLC_HDW_FLOW                0x01
+#define START_XMIT                   0x80
+#define ICOM_ACFG_DRIVE1             0x20
+#define ICOM_ACFG_NO_PARITY          0x00
+#define ICOM_ACFG_PARITY_ENAB        0x02
+#define ICOM_ACFG_PARITY_ODD         0x01
+#define ICOM_ACFG_8BPC               0x00
+#define ICOM_ACFG_7BPC               0x04
+#define ICOM_ACFG_6BPC               0x08
+#define ICOM_ACFG_5BPC               0x0C
+#define ICOM_ACFG_1STOP_BIT          0x00
+#define ICOM_ACFG_2STOP_BIT          0x10
+#define ICOM_DTR                     0x80
+#define ICOM_RTS                     0x40
+#define ICOM_RI                      0x08
+#define ICOM_DSR                     0x80
+#define ICOM_DCD                     0x20
+#define ICOM_CTS                     0x40
+
+#define NUM_XBUFFS 1
+#define NUM_RBUFFS 2
+#define RCV_BUFF_SZ 0x0200
+#define XMIT_BUFF_SZ 0x1000
+struct statusArea {
+    /**********************************************/
+	/* Transmit Status Area                       */
+    /**********************************************/
+	struct xmit_status_area{
+		__le32 leNext;	/* Next entry in Little Endian on Adapter */
+		__le32 leNextASD;
+		__le32 leBuffer;	/* Buffer for entry in LE for Adapter */
+		__le16 leLengthASD;
+		__le16 leOffsetASD;
+		__le16 leLength;	/* Length of data in segment */
+		__le16 flags;
+#define SA_FLAGS_DONE           0x0080	/* Done with Segment */
+#define SA_FLAGS_CONTINUED      0x8000	/* More Segments */
+#define SA_FLAGS_IDLE           0x4000	/* Mark IDLE after frm */
+#define SA_FLAGS_READY_TO_XMIT  0x0800
+#define SA_FLAGS_STAT_MASK      0x007F
+	} xmit[NUM_XBUFFS];
+
+    /**********************************************/
+	/* Receive Status Area                        */
+    /**********************************************/
+	struct {
+		__le32 leNext;	/* Next entry in Little Endian on Adapter */
+		__le32 leNextASD;
+		__le32 leBuffer;	/* Buffer for entry in LE for Adapter */
+		__le16 WorkingLength;	/* size of segment */
+		__le16 reserv01;
+		__le16 leLength;	/* Length of data in segment */
+		__le16 flags;
+#define SA_FL_RCV_DONE           0x0010	/* Data ready */
+#define SA_FLAGS_OVERRUN         0x0040
+#define SA_FLAGS_PARITY_ERROR    0x0080
+#define SA_FLAGS_FRAME_ERROR     0x0001
+#define SA_FLAGS_FRAME_TRUNC     0x0002
+#define SA_FLAGS_BREAK_DET       0x0004	/* set conditionally by device driver, not hardware */
+#define SA_FLAGS_RCV_MASK        0xFFE6
+	} rcv[NUM_RBUFFS];
+};
+
+struct icom_adapter;
+
+
+#define ICOM_MAJOR       243
+#define ICOM_MINOR_START 0
+
+struct icom_port {
+	struct uart_port uart_port;
+	unsigned char cable_id;
+	unsigned char read_status_mask;
+	unsigned char ignore_status_mask;
+	void __iomem * int_reg;
+	struct icom_regs __iomem *global_reg;
+	struct func_dram __iomem *dram;
+	int port;
+	struct statusArea *statStg;
+	dma_addr_t statStg_pci;
+	__le32 *xmitRestart;
+	dma_addr_t xmitRestart_pci;
+	unsigned char *xmit_buf;
+	dma_addr_t xmit_buf_pci;
+	unsigned char *recv_buf;
+	dma_addr_t recv_buf_pci;
+	int next_rcv;
+	int status;
+#define ICOM_PORT_ACTIVE	1	/* Port exists. */
+#define ICOM_PORT_OFF		0	/* Port does not exist. */
+	struct icom_adapter *adapter;
+};
+
+struct icom_adapter {
+	void __iomem * base_addr;
+	unsigned long base_addr_pci;
+	struct pci_dev *pci_dev;
+	struct icom_port port_info[4];
+	int index;
+	int version;
+#define ADAPTER_V1	0x0001
+#define ADAPTER_V2	0x0002
+	u32 subsystem_id;
+#define FOUR_PORT_MODEL				0x0252
+#define V2_TWO_PORTS_RVX			0x021A
+#define V2_ONE_PORT_RVX_ONE_PORT_IMBED_MDM	0x0251
+	int numb_ports;
+	struct list_head icom_adapter_entry;
+	struct kref kref;
+};
+
+/* prototype */
+extern void iCom_sercons_init(void);
+
+struct lookup_proc_table {
+	u32	__iomem *global_control_reg;
+	unsigned long	processor_id;
+};
+
+struct lookup_int_table {
+	u32	__iomem *global_int_mask;
+	unsigned long	processor_id;
+};
+
+static inline struct icom_port *to_icom_port(struct uart_port *port)
+{
+	return container_of(port, struct icom_port, uart_port);
+}
+
+static const struct pci_device_id icom_pci_table[] = {
+	{
+		.vendor = PCI_VENDOR_ID_IBM,
+		.device = PCI_DEVICE_ID_IBM_ICOM_DEV_ID_1,
+		.subvendor = PCI_ANY_ID,
+		.subdevice = PCI_ANY_ID,
+		.driver_data = ADAPTER_V1,
+	},
+	{
+		.vendor = PCI_VENDOR_ID_IBM,
+		.device = PCI_DEVICE_ID_IBM_ICOM_DEV_ID_2,
+		.subvendor = PCI_VENDOR_ID_IBM,
+		.subdevice = PCI_DEVICE_ID_IBM_ICOM_V2_TWO_PORTS_RVX,
+		.driver_data = ADAPTER_V2,
+	},
+	{
+		.vendor = PCI_VENDOR_ID_IBM,
+		.device = PCI_DEVICE_ID_IBM_ICOM_DEV_ID_2,
+		.subvendor = PCI_VENDOR_ID_IBM,
+		.subdevice = PCI_DEVICE_ID_IBM_ICOM_V2_ONE_PORT_RVX_ONE_PORT_MDM,
+		.driver_data = ADAPTER_V2,
+	},
+	{
+		.vendor = PCI_VENDOR_ID_IBM,
+		.device = PCI_DEVICE_ID_IBM_ICOM_DEV_ID_2,
+		.subvendor = PCI_VENDOR_ID_IBM,
+		.subdevice = PCI_DEVICE_ID_IBM_ICOM_FOUR_PORT_MODEL,
+		.driver_data = ADAPTER_V2,
+	},
+	{
+		.vendor = PCI_VENDOR_ID_IBM,
+		.device = PCI_DEVICE_ID_IBM_ICOM_DEV_ID_2,
+		.subvendor = PCI_VENDOR_ID_IBM,
+		.subdevice = PCI_DEVICE_ID_IBM_ICOM_V2_ONE_PORT_RVX_ONE_PORT_MDM_PCIE,
+		.driver_data = ADAPTER_V2,
+	},
+	{}
+};
+
+static struct lookup_proc_table start_proc[4] = {
+	{NULL, ICOM_CONTROL_START_A},
+	{NULL, ICOM_CONTROL_START_B},
+	{NULL, ICOM_CONTROL_START_C},
+	{NULL, ICOM_CONTROL_START_D}
+};
+
+
+static struct lookup_proc_table stop_proc[4] = {
+	{NULL, ICOM_CONTROL_STOP_A},
+	{NULL, ICOM_CONTROL_STOP_B},
+	{NULL, ICOM_CONTROL_STOP_C},
+	{NULL, ICOM_CONTROL_STOP_D}
+};
+
+static struct lookup_int_table int_mask_tbl[4] = {
+	{NULL, ICOM_INT_MASK_PRC_A},
+	{NULL, ICOM_INT_MASK_PRC_B},
+	{NULL, ICOM_INT_MASK_PRC_C},
+	{NULL, ICOM_INT_MASK_PRC_D},
+};
+
+
+MODULE_DEVICE_TABLE(pci, icom_pci_table);
+
+static LIST_HEAD(icom_adapter_head);
+
+/* spinlock for adapter initialization and changing adapter operations */
+static DEFINE_SPINLOCK(icom_lock);
+
+#ifdef ICOM_TRACE
+static inline void trace(struct icom_port *icom_port, char *trace_pt,
+			unsigned long trace_data)
+{
+	dev_info(&icom_port->adapter->pci_dev->dev, ":%d:%s - %lx\n",
+	icom_port->port, trace_pt, trace_data);
+}
+#else
+static inline void trace(struct icom_port *icom_port, char *trace_pt, unsigned long trace_data) {};
+#endif
+static void icom_kref_release(struct kref *kref);
+
+static void free_port_memory(struct icom_port *icom_port)
+{
+	struct pci_dev *dev = icom_port->adapter->pci_dev;
+
+	trace(icom_port, "RET_PORT_MEM", 0);
+	if (icom_port->recv_buf) {
+		dma_free_coherent(&dev->dev, 4096, icom_port->recv_buf,
+				  icom_port->recv_buf_pci);
+		icom_port->recv_buf = NULL;
+	}
+	if (icom_port->xmit_buf) {
+		dma_free_coherent(&dev->dev, 4096, icom_port->xmit_buf,
+				  icom_port->xmit_buf_pci);
+		icom_port->xmit_buf = NULL;
+	}
+	if (icom_port->statStg) {
+		dma_free_coherent(&dev->dev, 4096, icom_port->statStg,
+				  icom_port->statStg_pci);
+		icom_port->statStg = NULL;
+	}
+
+	if (icom_port->xmitRestart) {
+		dma_free_coherent(&dev->dev, 4096, icom_port->xmitRestart,
+				  icom_port->xmitRestart_pci);
+		icom_port->xmitRestart = NULL;
+	}
+}
+
+static int get_port_memory(struct icom_port *icom_port)
+{
+	int index;
+	unsigned long stgAddr;
+	unsigned long startStgAddr;
+	unsigned long offset;
+	struct pci_dev *dev = icom_port->adapter->pci_dev;
+
+	icom_port->xmit_buf =
+	    dma_alloc_coherent(&dev->dev, 4096, &icom_port->xmit_buf_pci,
+			       GFP_KERNEL);
+	if (!icom_port->xmit_buf) {
+		dev_err(&dev->dev, "Can not allocate Transmit buffer\n");
+		return -ENOMEM;
+	}
+
+	trace(icom_port, "GET_PORT_MEM",
+	      (unsigned long) icom_port->xmit_buf);
+
+	icom_port->recv_buf =
+	    dma_alloc_coherent(&dev->dev, 4096, &icom_port->recv_buf_pci,
+			       GFP_KERNEL);
+	if (!icom_port->recv_buf) {
+		dev_err(&dev->dev, "Can not allocate Receive buffer\n");
+		free_port_memory(icom_port);
+		return -ENOMEM;
+	}
+	trace(icom_port, "GET_PORT_MEM",
+	      (unsigned long) icom_port->recv_buf);
+
+	icom_port->statStg =
+	    dma_alloc_coherent(&dev->dev, 4096, &icom_port->statStg_pci,
+			       GFP_KERNEL);
+	if (!icom_port->statStg) {
+		dev_err(&dev->dev, "Can not allocate Status buffer\n");
+		free_port_memory(icom_port);
+		return -ENOMEM;
+	}
+	trace(icom_port, "GET_PORT_MEM",
+	      (unsigned long) icom_port->statStg);
+
+	icom_port->xmitRestart =
+	    dma_alloc_coherent(&dev->dev, 4096, &icom_port->xmitRestart_pci,
+			       GFP_KERNEL);
+	if (!icom_port->xmitRestart) {
+		dev_err(&dev->dev,
+			"Can not allocate xmit Restart buffer\n");
+		free_port_memory(icom_port);
+		return -ENOMEM;
+	}
+
+	/* FODs: Frame Out Descriptor Queue, this is a FIFO queue that
+           indicates that frames are to be transmitted
+	*/
+
+	stgAddr = (unsigned long) icom_port->statStg;
+	for (index = 0; index < NUM_XBUFFS; index++) {
+		trace(icom_port, "FOD_ADDR", stgAddr);
+		stgAddr = stgAddr + sizeof(icom_port->statStg->xmit[0]);
+		if (index < (NUM_XBUFFS - 1)) {
+			memset(&icom_port->statStg->xmit[index], 0, sizeof(struct xmit_status_area));
+			icom_port->statStg->xmit[index].leLengthASD =
+			    cpu_to_le16(XMIT_BUFF_SZ);
+			trace(icom_port, "FOD_ADDR", stgAddr);
+			trace(icom_port, "FOD_XBUFF",
+			      (unsigned long) icom_port->xmit_buf);
+			icom_port->statStg->xmit[index].leBuffer =
+			    cpu_to_le32(icom_port->xmit_buf_pci);
+		} else if (index == (NUM_XBUFFS - 1)) {
+			memset(&icom_port->statStg->xmit[index], 0, sizeof(struct xmit_status_area));
+			icom_port->statStg->xmit[index].leLengthASD =
+			    cpu_to_le16(XMIT_BUFF_SZ);
+			trace(icom_port, "FOD_XBUFF",
+			      (unsigned long) icom_port->xmit_buf);
+			icom_port->statStg->xmit[index].leBuffer =
+			    cpu_to_le32(icom_port->xmit_buf_pci);
+		} else {
+			memset(&icom_port->statStg->xmit[index], 0, sizeof(struct xmit_status_area));
+		}
+	}
+	/* FIDs */
+	startStgAddr = stgAddr;
+
+	/* fill in every entry, even if no buffer */
+	for (index = 0; index <  NUM_RBUFFS; index++) {
+		trace(icom_port, "FID_ADDR", stgAddr);
+		stgAddr = stgAddr + sizeof(icom_port->statStg->rcv[0]);
+		icom_port->statStg->rcv[index].leLength = 0;
+		icom_port->statStg->rcv[index].WorkingLength =
+		    cpu_to_le16(RCV_BUFF_SZ);
+		if (index < (NUM_RBUFFS - 1) ) {
+			offset = stgAddr - (unsigned long) icom_port->statStg;
+			icom_port->statStg->rcv[index].leNext =
+			      cpu_to_le32(icom_port-> statStg_pci + offset);
+			trace(icom_port, "FID_RBUFF",
+			      (unsigned long) icom_port->recv_buf);
+			icom_port->statStg->rcv[index].leBuffer =
+			    cpu_to_le32(icom_port->recv_buf_pci);
+		} else if (index == (NUM_RBUFFS -1) ) {
+			offset = startStgAddr - (unsigned long) icom_port->statStg;
+			icom_port->statStg->rcv[index].leNext =
+			    cpu_to_le32(icom_port-> statStg_pci + offset);
+			trace(icom_port, "FID_RBUFF",
+			      (unsigned long) icom_port->recv_buf + 2048);
+			icom_port->statStg->rcv[index].leBuffer =
+			    cpu_to_le32(icom_port->recv_buf_pci + 2048);
+		} else {
+			icom_port->statStg->rcv[index].leNext = 0;
+			icom_port->statStg->rcv[index].leBuffer = 0;
+		}
+	}
+
+	return 0;
+}
+
+static void stop_processor(struct icom_port *icom_port)
+{
+	unsigned long temp;
+	unsigned long flags;
+	int port;
+
+	spin_lock_irqsave(&icom_lock, flags);
+
+	port = icom_port->port;
+	if (port >= ARRAY_SIZE(stop_proc)) {
+		dev_err(&icom_port->adapter->pci_dev->dev,
+			"Invalid port assignment\n");
+		goto unlock;
+	}
+
+	if (port == 0 || port == 1)
+		stop_proc[port].global_control_reg = &icom_port->global_reg->control;
+	else
+		stop_proc[port].global_control_reg = &icom_port->global_reg->control_2;
+
+	temp = readl(stop_proc[port].global_control_reg);
+	temp = (temp & ~start_proc[port].processor_id) | stop_proc[port].processor_id;
+	writel(temp, stop_proc[port].global_control_reg);
+
+	/* write flush */
+	readl(stop_proc[port].global_control_reg);
+
+unlock:
+	spin_unlock_irqrestore(&icom_lock, flags);
+}
+
+static void start_processor(struct icom_port *icom_port)
+{
+	unsigned long temp;
+	unsigned long flags;
+	int port;
+
+	spin_lock_irqsave(&icom_lock, flags);
+
+	port = icom_port->port;
+	if (port >= ARRAY_SIZE(start_proc)) {
+		dev_err(&icom_port->adapter->pci_dev->dev,
+			"Invalid port assignment\n");
+		goto unlock;
+	}
+
+	if (port == 0 || port == 1)
+		start_proc[port].global_control_reg = &icom_port->global_reg->control;
+	else
+		start_proc[port].global_control_reg = &icom_port->global_reg->control_2;
+
+	temp = readl(start_proc[port].global_control_reg);
+	temp = (temp & ~stop_proc[port].processor_id) | start_proc[port].processor_id;
+	writel(temp, start_proc[port].global_control_reg);
+
+	/* write flush */
+	readl(start_proc[port].global_control_reg);
+
+unlock:
+	spin_unlock_irqrestore(&icom_lock, flags);
+}
+
+static void load_code(struct icom_port *icom_port)
+{
+	const struct firmware *fw;
+	char __iomem *iram_ptr;
+	int index;
+	int status = 0;
+	void __iomem *dram_ptr = icom_port->dram;
+	dma_addr_t temp_pci;
+	unsigned char *new_page = NULL;
+	unsigned char cable_id = NO_CABLE;
+	struct pci_dev *dev = icom_port->adapter->pci_dev;
+
+	/* Clear out any pending interrupts */
+	writew(0x3FFF, icom_port->int_reg);
+
+	trace(icom_port, "CLEAR_INTERRUPTS", 0);
+
+	/* Stop processor */
+	stop_processor(icom_port);
+
+	/* Zero out DRAM */
+	memset_io(dram_ptr, 0, 512);
+
+	/* Load Call Setup into Adapter */
+	if (request_firmware(&fw, "icom_call_setup.bin", &dev->dev) < 0) {
+		dev_err(&dev->dev,"Unable to load icom_call_setup.bin firmware image\n");
+		status = -1;
+		goto load_code_exit;
+	}
+
+	if (fw->size > ICOM_DCE_IRAM_OFFSET) {
+		dev_err(&dev->dev, "Invalid firmware image for icom_call_setup.bin found.\n");
+		release_firmware(fw);
+		status = -1;
+		goto load_code_exit;
+	}
+
+	iram_ptr = (char __iomem *)icom_port->dram + ICOM_IRAM_OFFSET;
+	for (index = 0; index < fw->size; index++)
+		writeb(fw->data[index], &iram_ptr[index]);
+
+	release_firmware(fw);
+
+	/* Load Resident DCE portion of Adapter */
+	if (request_firmware(&fw, "icom_res_dce.bin", &dev->dev) < 0) {
+		dev_err(&dev->dev,"Unable to load icom_res_dce.bin firmware image\n");
+		status = -1;
+		goto load_code_exit;
+	}
+
+	if (fw->size > ICOM_IRAM_SIZE) {
+		dev_err(&dev->dev, "Invalid firmware image for icom_res_dce.bin found.\n");
+		release_firmware(fw);
+		status = -1;
+		goto load_code_exit;
+	}
+
+	iram_ptr = (char __iomem *) icom_port->dram + ICOM_IRAM_OFFSET;
+	for (index = ICOM_DCE_IRAM_OFFSET; index < fw->size; index++)
+		writeb(fw->data[index], &iram_ptr[index]);
+
+	release_firmware(fw);
+
+	/* Set Hardware level */
+	if (icom_port->adapter->version == ADAPTER_V2)
+		writeb(V2_HARDWARE, &(icom_port->dram->misc_flags));
+
+	/* Start the processor in Adapter */
+	start_processor(icom_port);
+
+	writeb((HDLC_PPP_PURE_ASYNC | HDLC_FF_FILL),
+	       &(icom_port->dram->HDLCConfigReg));
+	writeb(0x04, &(icom_port->dram->FlagFillIdleTimer));	/* 0.5 seconds */
+	writeb(0x00, &(icom_port->dram->CmdReg));
+	writeb(0x10, &(icom_port->dram->async_config3));
+	writeb((ICOM_ACFG_DRIVE1 | ICOM_ACFG_NO_PARITY | ICOM_ACFG_8BPC |
+		ICOM_ACFG_1STOP_BIT), &(icom_port->dram->async_config2));
+
+	/*Set up data in icom DRAM to indicate where personality
+	 *code is located and its length.
+	 */
+	new_page = dma_alloc_coherent(&dev->dev, 4096, &temp_pci, GFP_KERNEL);
+
+	if (!new_page) {
+		dev_err(&dev->dev, "Can not allocate DMA buffer\n");
+		status = -1;
+		goto load_code_exit;
+	}
+
+	if (request_firmware(&fw, "icom_asc.bin", &dev->dev) < 0) {
+		dev_err(&dev->dev,"Unable to load icom_asc.bin firmware image\n");
+		status = -1;
+		goto load_code_exit;
+	}
+
+	if (fw->size > ICOM_DCE_IRAM_OFFSET) {
+		dev_err(&dev->dev, "Invalid firmware image for icom_asc.bin found.\n");
+		release_firmware(fw);
+		status = -1;
+		goto load_code_exit;
+	}
+
+	for (index = 0; index < fw->size; index++)
+		new_page[index] = fw->data[index];
+
+	writeb((char) ((fw->size + 16)/16), &icom_port->dram->mac_length);
+	writel(temp_pci, &icom_port->dram->mac_load_addr);
+
+	release_firmware(fw);
+
+	/*Setting the syncReg to 0x80 causes adapter to start downloading
+	   the personality code into adapter instruction RAM.
+	   Once code is loaded, it will begin executing and, based on
+	   information provided above, will start DMAing data from
+	   shared memory to adapter DRAM.
+	 */
+	/* the wait loop below verifies this write operation has been done
+	   and processed
+	*/
+	writeb(START_DOWNLOAD, &icom_port->dram->sync);
+
+	/* Wait max 1 Sec for data download and processor to start */
+	for (index = 0; index < 10; index++) {
+		msleep(100);
+		if (readb(&icom_port->dram->misc_flags) & ICOM_HDW_ACTIVE)
+			break;
+	}
+
+	if (index == 10)
+		status = -1;
+
+	/*
+	 * check Cable ID
+	 */
+	cable_id = readb(&icom_port->dram->cable_id);
+
+	if (cable_id & ICOM_CABLE_ID_VALID) {
+		/* Get cable ID into the lower 4 bits (standard form) */
+		cable_id = (cable_id & ICOM_CABLE_ID_MASK) >> 4;
+		icom_port->cable_id = cable_id;
+	} else {
+		dev_err(&dev->dev,"Invalid or no cable attached\n");
+		icom_port->cable_id = NO_CABLE;
+	}
+
+      load_code_exit:
+
+	if (status != 0) {
+		/* Clear out any pending interrupts */
+		writew(0x3FFF, icom_port->int_reg);
+
+		/* Turn off port */
+		writeb(ICOM_DISABLE, &(icom_port->dram->disable));
+
+		/* Stop processor */
+		stop_processor(icom_port);
+
+		dev_err(&icom_port->adapter->pci_dev->dev,"Port not operational\n");
+	}
+
+	if (new_page != NULL)
+		dma_free_coherent(&dev->dev, 4096, new_page, temp_pci);
+}
+
+static int startup(struct icom_port *icom_port)
+{
+	unsigned long temp;
+	unsigned char cable_id, raw_cable_id;
+	unsigned long flags;
+	int port;
+
+	trace(icom_port, "STARTUP", 0);
+
+	if (!icom_port->dram) {
+		/* should NEVER be NULL */
+		dev_err(&icom_port->adapter->pci_dev->dev,
+			"Unusable Port, port configuration missing\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * check Cable ID
+	 */
+	raw_cable_id = readb(&icom_port->dram->cable_id);
+	trace(icom_port, "CABLE_ID", raw_cable_id);
+
+	/* Get cable ID into the lower 4 bits (standard form) */
+	cable_id = (raw_cable_id & ICOM_CABLE_ID_MASK) >> 4;
+
+	/* Check for valid Cable ID */
+	if (!(raw_cable_id & ICOM_CABLE_ID_VALID) ||
+	    (cable_id != icom_port->cable_id)) {
+
+		/* reload adapter code, pick up any potential changes in cable id */
+		load_code(icom_port);
+
+		/* still no sign of cable, error out */
+		raw_cable_id = readb(&icom_port->dram->cable_id);
+		cable_id = (raw_cable_id & ICOM_CABLE_ID_MASK) >> 4;
+		if (!(raw_cable_id & ICOM_CABLE_ID_VALID) ||
+		    (icom_port->cable_id == NO_CABLE))
+			return -EIO;
+	}
+
+	/*
+	 * Finally, clear and  enable interrupts
+	 */
+	spin_lock_irqsave(&icom_lock, flags);
+	port = icom_port->port;
+	if (port >= ARRAY_SIZE(int_mask_tbl)) {
+		dev_err(&icom_port->adapter->pci_dev->dev,
+			"Invalid port assignment\n");
+		goto unlock;
+	}
+
+	if (port == 0 || port == 1)
+		int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask;
+	else
+		int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask_2;
+
+	if (port == 0 || port == 2)
+		writew(0x00FF, icom_port->int_reg);
+	else
+		writew(0x3F00, icom_port->int_reg);
+
+	temp = readl(int_mask_tbl[port].global_int_mask);
+	writel(temp & ~int_mask_tbl[port].processor_id, int_mask_tbl[port].global_int_mask);
+
+	/* write flush */
+	readl(int_mask_tbl[port].global_int_mask);
+
+unlock:
+	spin_unlock_irqrestore(&icom_lock, flags);
+	return 0;
+}
+
+static void shutdown(struct icom_port *icom_port)
+{
+	unsigned long temp;
+	unsigned char cmdReg;
+	unsigned long flags;
+	int port;
+
+	spin_lock_irqsave(&icom_lock, flags);
+	trace(icom_port, "SHUTDOWN", 0);
+
+	/*
+	 * disable all interrupts
+	 */
+	port = icom_port->port;
+	if (port >= ARRAY_SIZE(int_mask_tbl)) {
+		dev_err(&icom_port->adapter->pci_dev->dev,
+			"Invalid port assignment\n");
+		goto unlock;
+	}
+	if (port == 0 || port == 1)
+		int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask;
+	else
+		int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask_2;
+
+	temp = readl(int_mask_tbl[port].global_int_mask);
+	writel(temp | int_mask_tbl[port].processor_id, int_mask_tbl[port].global_int_mask);
+
+	/* write flush */
+	readl(int_mask_tbl[port].global_int_mask);
+
+unlock:
+	spin_unlock_irqrestore(&icom_lock, flags);
+
+	/*
+	 * disable break condition
+	 */
+	cmdReg = readb(&icom_port->dram->CmdReg);
+	if (cmdReg & CMD_SND_BREAK) {
+		writeb(cmdReg & ~CMD_SND_BREAK, &icom_port->dram->CmdReg);
+	}
+}
+
+static int icom_write(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned long data_count;
+	unsigned char cmdReg;
+	unsigned long offset;
+	int temp_tail = port->state->xmit.tail;
+
+	trace(icom_port, "WRITE", 0);
+
+	if (le16_to_cpu(icom_port->statStg->xmit[0].flags) &
+	    SA_FLAGS_READY_TO_XMIT) {
+		trace(icom_port, "WRITE_FULL", 0);
+		return 0;
+	}
+
+	data_count = 0;
+	while ((port->state->xmit.head != temp_tail) &&
+	       (data_count <= XMIT_BUFF_SZ)) {
+
+		icom_port->xmit_buf[data_count++] =
+		    port->state->xmit.buf[temp_tail];
+
+		temp_tail++;
+		temp_tail &= (UART_XMIT_SIZE - 1);
+	}
+
+	if (data_count) {
+		icom_port->statStg->xmit[0].flags =
+		    cpu_to_le16(SA_FLAGS_READY_TO_XMIT);
+		icom_port->statStg->xmit[0].leLength =
+		    cpu_to_le16(data_count);
+		offset =
+		    (unsigned long) &icom_port->statStg->xmit[0] -
+		    (unsigned long) icom_port->statStg;
+		*icom_port->xmitRestart =
+		    cpu_to_le32(icom_port->statStg_pci + offset);
+		cmdReg = readb(&icom_port->dram->CmdReg);
+		writeb(cmdReg | CMD_XMIT_RCV_ENABLE,
+		       &icom_port->dram->CmdReg);
+		writeb(START_XMIT, &icom_port->dram->StartXmitCmd);
+		trace(icom_port, "WRITE_START", data_count);
+		/* write flush */
+		readb(&icom_port->dram->StartXmitCmd);
+	}
+
+	return data_count;
+}
+
+static inline void check_modem_status(struct icom_port *icom_port)
+{
+	static char old_status = 0;
+	char delta_status;
+	unsigned char status;
+
+	spin_lock(&icom_port->uart_port.lock);
+
+	/*modem input register */
+	status = readb(&icom_port->dram->isr);
+	trace(icom_port, "CHECK_MODEM", status);
+	delta_status = status ^ old_status;
+	if (delta_status) {
+		if (delta_status & ICOM_RI)
+			icom_port->uart_port.icount.rng++;
+		if (delta_status & ICOM_DSR)
+			icom_port->uart_port.icount.dsr++;
+		if (delta_status & ICOM_DCD)
+			uart_handle_dcd_change(&icom_port->uart_port,
+					       delta_status & ICOM_DCD);
+		if (delta_status & ICOM_CTS)
+			uart_handle_cts_change(&icom_port->uart_port,
+					       delta_status & ICOM_CTS);
+
+		wake_up_interruptible(&icom_port->uart_port.state->
+				      port.delta_msr_wait);
+		old_status = status;
+	}
+	spin_unlock(&icom_port->uart_port.lock);
+}
+
+static void xmit_interrupt(u16 port_int_reg, struct icom_port *icom_port)
+{
+	u16 count, i;
+
+	if (port_int_reg & (INT_XMIT_COMPLETED)) {
+		trace(icom_port, "XMIT_COMPLETE", 0);
+
+		/* clear buffer in use bit */
+		icom_port->statStg->xmit[0].flags &=
+			cpu_to_le16(~SA_FLAGS_READY_TO_XMIT);
+
+		count = le16_to_cpu(icom_port->statStg->xmit[0].leLength);
+		icom_port->uart_port.icount.tx += count;
+
+		for (i=0; i<count &&
+			!uart_circ_empty(&icom_port->uart_port.state->xmit); i++) {
+
+			icom_port->uart_port.state->xmit.tail++;
+			icom_port->uart_port.state->xmit.tail &=
+				(UART_XMIT_SIZE - 1);
+		}
+
+		if (!icom_write(&icom_port->uart_port))
+			/* activate write queue */
+			uart_write_wakeup(&icom_port->uart_port);
+	} else
+		trace(icom_port, "XMIT_DISABLED", 0);
+}
+
+static void recv_interrupt(u16 port_int_reg, struct icom_port *icom_port)
+{
+	short int count, rcv_buff;
+	struct tty_port *port = &icom_port->uart_port.state->port;
+	u16 status;
+	struct uart_icount *icount;
+	unsigned long offset;
+	unsigned char flag;
+
+	trace(icom_port, "RCV_COMPLETE", 0);
+	rcv_buff = icom_port->next_rcv;
+
+	status = le16_to_cpu(icom_port->statStg->rcv[rcv_buff].flags);
+	while (status & SA_FL_RCV_DONE) {
+		int first = -1;
+
+		trace(icom_port, "FID_STATUS", status);
+		count = le16_to_cpu(icom_port->statStg->rcv[rcv_buff].leLength);
+
+		trace(icom_port, "RCV_COUNT", count);
+
+		trace(icom_port, "REAL_COUNT", count);
+
+		offset = le32_to_cpu(icom_port->statStg->rcv[rcv_buff].leBuffer) -
+			icom_port->recv_buf_pci;
+
+		/* Block copy all but the last byte as this may have status */
+		if (count > 0) {
+			first = icom_port->recv_buf[offset];
+			tty_insert_flip_string(port, icom_port->recv_buf + offset, count - 1);
+		}
+
+		icount = &icom_port->uart_port.icount;
+		icount->rx += count;
+
+		/* Break detect logic */
+		if ((status & SA_FLAGS_FRAME_ERROR)
+		    && first == 0) {
+			status &= ~SA_FLAGS_FRAME_ERROR;
+			status |= SA_FLAGS_BREAK_DET;
+			trace(icom_port, "BREAK_DET", 0);
+		}
+
+		flag = TTY_NORMAL;
+
+		if (status &
+		    (SA_FLAGS_BREAK_DET | SA_FLAGS_PARITY_ERROR |
+		     SA_FLAGS_FRAME_ERROR | SA_FLAGS_OVERRUN)) {
+
+			if (status & SA_FLAGS_BREAK_DET)
+				icount->brk++;
+			if (status & SA_FLAGS_PARITY_ERROR)
+				icount->parity++;
+			if (status & SA_FLAGS_FRAME_ERROR)
+				icount->frame++;
+			if (status & SA_FLAGS_OVERRUN)
+				icount->overrun++;
+
+			/*
+			 * Now check to see if character should be
+			 * ignored, and mask off conditions which
+			 * should be ignored.
+			 */
+			if (status & icom_port->ignore_status_mask) {
+				trace(icom_port, "IGNORE_CHAR", 0);
+				goto ignore_char;
+			}
+
+			status &= icom_port->read_status_mask;
+
+			if (status & SA_FLAGS_BREAK_DET) {
+				flag = TTY_BREAK;
+			} else if (status & SA_FLAGS_PARITY_ERROR) {
+				trace(icom_port, "PARITY_ERROR", 0);
+				flag = TTY_PARITY;
+			} else if (status & SA_FLAGS_FRAME_ERROR)
+				flag = TTY_FRAME;
+
+		}
+
+		tty_insert_flip_char(port, *(icom_port->recv_buf + offset + count - 1), flag);
+
+		if (status & SA_FLAGS_OVERRUN)
+			/*
+			 * Overrun is special, since it's
+			 * reported immediately, and doesn't
+			 * affect the current character
+			 */
+			tty_insert_flip_char(port, 0, TTY_OVERRUN);
+ignore_char:
+		icom_port->statStg->rcv[rcv_buff].flags = 0;
+		icom_port->statStg->rcv[rcv_buff].leLength = 0;
+		icom_port->statStg->rcv[rcv_buff].WorkingLength =
+			cpu_to_le16(RCV_BUFF_SZ);
+
+		rcv_buff++;
+		if (rcv_buff == NUM_RBUFFS)
+			rcv_buff = 0;
+
+		status = le16_to_cpu(icom_port->statStg->rcv[rcv_buff].flags);
+	}
+	icom_port->next_rcv = rcv_buff;
+
+	tty_flip_buffer_push(port);
+}
+
+static void process_interrupt(u16 port_int_reg,
+			      struct icom_port *icom_port)
+{
+
+	spin_lock(&icom_port->uart_port.lock);
+	trace(icom_port, "INTERRUPT", port_int_reg);
+
+	if (port_int_reg & (INT_XMIT_COMPLETED | INT_XMIT_DISABLED))
+		xmit_interrupt(port_int_reg, icom_port);
+
+	if (port_int_reg & INT_RCV_COMPLETED)
+		recv_interrupt(port_int_reg, icom_port);
+
+	spin_unlock(&icom_port->uart_port.lock);
+}
+
+static irqreturn_t icom_interrupt(int irq, void *dev_id)
+{
+	void __iomem * int_reg;
+	u32 adapter_interrupts;
+	u16 port_int_reg;
+	struct icom_adapter *icom_adapter;
+	struct icom_port *icom_port;
+
+	/* find icom_port for this interrupt */
+	icom_adapter = (struct icom_adapter *) dev_id;
+
+	if (icom_adapter->version == ADAPTER_V2) {
+		int_reg = icom_adapter->base_addr + 0x8024;
+
+		adapter_interrupts = readl(int_reg);
+
+		if (adapter_interrupts & 0x00003FFF) {
+			/* port 2 interrupt,  NOTE:  for all ADAPTER_V2, port 2 will be active */
+			icom_port = &icom_adapter->port_info[2];
+			port_int_reg = (u16) adapter_interrupts;
+			process_interrupt(port_int_reg, icom_port);
+			check_modem_status(icom_port);
+		}
+		if (adapter_interrupts & 0x3FFF0000) {
+			/* port 3 interrupt */
+			icom_port = &icom_adapter->port_info[3];
+			if (icom_port->status == ICOM_PORT_ACTIVE) {
+				port_int_reg =
+				    (u16) (adapter_interrupts >> 16);
+				process_interrupt(port_int_reg, icom_port);
+				check_modem_status(icom_port);
+			}
+		}
+
+		/* Clear out any pending interrupts */
+		writel(adapter_interrupts, int_reg);
+
+		int_reg = icom_adapter->base_addr + 0x8004;
+	} else {
+		int_reg = icom_adapter->base_addr + 0x4004;
+	}
+
+	adapter_interrupts = readl(int_reg);
+
+	if (adapter_interrupts & 0x00003FFF) {
+		/* port 0 interrupt, NOTE:  for all adapters, port 0 will be active */
+		icom_port = &icom_adapter->port_info[0];
+		port_int_reg = (u16) adapter_interrupts;
+		process_interrupt(port_int_reg, icom_port);
+		check_modem_status(icom_port);
+	}
+	if (adapter_interrupts & 0x3FFF0000) {
+		/* port 1 interrupt */
+		icom_port = &icom_adapter->port_info[1];
+		if (icom_port->status == ICOM_PORT_ACTIVE) {
+			port_int_reg = (u16) (adapter_interrupts >> 16);
+			process_interrupt(port_int_reg, icom_port);
+			check_modem_status(icom_port);
+		}
+	}
+
+	/* Clear out any pending interrupts */
+	writel(adapter_interrupts, int_reg);
+
+	/* flush the write */
+	adapter_interrupts = readl(int_reg);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * ------------------------------------------------------------------
+ * Begin serial-core API
+ * ------------------------------------------------------------------
+ */
+static unsigned int icom_tx_empty(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (le16_to_cpu(icom_port->statStg->xmit[0].flags) &
+	    SA_FLAGS_READY_TO_XMIT)
+		ret = TIOCSER_TEMT;
+	else
+		ret = 0;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	return ret;
+}
+
+static void icom_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char local_osr;
+
+	trace(icom_port, "SET_MODEM", 0);
+	local_osr = readb(&icom_port->dram->osr);
+
+	if (mctrl & TIOCM_RTS) {
+		trace(icom_port, "RAISE_RTS", 0);
+		local_osr |= ICOM_RTS;
+	} else {
+		trace(icom_port, "LOWER_RTS", 0);
+		local_osr &= ~ICOM_RTS;
+	}
+
+	if (mctrl & TIOCM_DTR) {
+		trace(icom_port, "RAISE_DTR", 0);
+		local_osr |= ICOM_DTR;
+	} else {
+		trace(icom_port, "LOWER_DTR", 0);
+		local_osr &= ~ICOM_DTR;
+	}
+
+	writeb(local_osr, &icom_port->dram->osr);
+}
+
+static unsigned int icom_get_mctrl(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char status;
+	unsigned int result;
+
+	trace(icom_port, "GET_MODEM", 0);
+
+	status = readb(&icom_port->dram->isr);
+
+	result = ((status & ICOM_DCD) ? TIOCM_CAR : 0)
+	    | ((status & ICOM_RI) ? TIOCM_RNG : 0)
+	    | ((status & ICOM_DSR) ? TIOCM_DSR : 0)
+	    | ((status & ICOM_CTS) ? TIOCM_CTS : 0);
+	return result;
+}
+
+static void icom_stop_tx(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char cmdReg;
+
+	trace(icom_port, "STOP", 0);
+	cmdReg = readb(&icom_port->dram->CmdReg);
+	writeb(cmdReg | CMD_HOLD_XMIT, &icom_port->dram->CmdReg);
+}
+
+static void icom_start_tx(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char cmdReg;
+
+	trace(icom_port, "START", 0);
+	cmdReg = readb(&icom_port->dram->CmdReg);
+	if ((cmdReg & CMD_HOLD_XMIT) == CMD_HOLD_XMIT)
+		writeb(cmdReg & ~CMD_HOLD_XMIT,
+		       &icom_port->dram->CmdReg);
+
+	icom_write(port);
+}
+
+static void icom_send_xchar(struct uart_port *port, char ch)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char xdata;
+	int index;
+	unsigned long flags;
+
+	trace(icom_port, "SEND_XCHAR", ch);
+
+	/* wait .1 sec to send char */
+	for (index = 0; index < 10; index++) {
+		spin_lock_irqsave(&port->lock, flags);
+		xdata = readb(&icom_port->dram->xchar);
+		if (xdata == 0x00) {
+			trace(icom_port, "QUICK_WRITE", 0);
+			writeb(ch, &icom_port->dram->xchar);
+
+			/* flush write operation */
+			xdata = readb(&icom_port->dram->xchar);
+			spin_unlock_irqrestore(&port->lock, flags);
+			break;
+		}
+		spin_unlock_irqrestore(&port->lock, flags);
+		msleep(10);
+	}
+}
+
+static void icom_stop_rx(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char cmdReg;
+
+	cmdReg = readb(&icom_port->dram->CmdReg);
+	writeb(cmdReg & ~CMD_RCV_ENABLE, &icom_port->dram->CmdReg);
+}
+
+static void icom_break(struct uart_port *port, int break_state)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char cmdReg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	trace(icom_port, "BREAK", 0);
+	cmdReg = readb(&icom_port->dram->CmdReg);
+	if (break_state == -1) {
+		writeb(cmdReg | CMD_SND_BREAK, &icom_port->dram->CmdReg);
+	} else {
+		writeb(cmdReg & ~CMD_SND_BREAK, &icom_port->dram->CmdReg);
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int icom_open(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	int retval;
+
+	kref_get(&icom_port->adapter->kref);
+	retval = startup(icom_port);
+
+	if (retval) {
+		kref_put(&icom_port->adapter->kref, icom_kref_release);
+		trace(icom_port, "STARTUP_ERROR", 0);
+		return retval;
+	}
+
+	return 0;
+}
+
+static void icom_close(struct uart_port *port)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	unsigned char cmdReg;
+
+	trace(icom_port, "CLOSE", 0);
+
+	/* stop receiver */
+	cmdReg = readb(&icom_port->dram->CmdReg);
+	writeb(cmdReg & ~CMD_RCV_ENABLE, &icom_port->dram->CmdReg);
+
+	shutdown(icom_port);
+
+	kref_put(&icom_port->adapter->kref, icom_kref_release);
+}
+
+static void icom_set_termios(struct uart_port *port, struct ktermios *termios,
+			     const struct ktermios *old_termios)
+{
+	struct icom_port *icom_port = to_icom_port(port);
+	int baud;
+	unsigned cflag, iflag;
+	char new_config2;
+	char new_config3 = 0;
+	char tmp_byte;
+	int index;
+	int rcv_buff, xmit_buff;
+	unsigned long offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	trace(icom_port, "CHANGE_SPEED", 0);
+
+	cflag = termios->c_cflag;
+	iflag = termios->c_iflag;
+
+	new_config2 = ICOM_ACFG_DRIVE1;
+
+	/* byte size and parity */
+	switch (cflag & CSIZE) {
+	case CS5:		/* 5 bits/char */
+		new_config2 |= ICOM_ACFG_5BPC;
+		break;
+	case CS6:		/* 6 bits/char */
+		new_config2 |= ICOM_ACFG_6BPC;
+		break;
+	case CS7:		/* 7 bits/char */
+		new_config2 |= ICOM_ACFG_7BPC;
+		break;
+	case CS8:		/* 8 bits/char */
+		new_config2 |= ICOM_ACFG_8BPC;
+		break;
+	default:
+		break;
+	}
+	if (cflag & CSTOPB) {
+		/* 2 stop bits */
+		new_config2 |= ICOM_ACFG_2STOP_BIT;
+	}
+	if (cflag & PARENB) {
+		/* parity bit enabled */
+		new_config2 |= ICOM_ACFG_PARITY_ENAB;
+		trace(icom_port, "PARENB", 0);
+	}
+	if (cflag & PARODD) {
+		/* odd parity */
+		new_config2 |= ICOM_ACFG_PARITY_ODD;
+		trace(icom_port, "PARODD", 0);
+	}
+
+	/* Determine divisor based on baud rate */
+	baud = uart_get_baud_rate(port, termios, old_termios,
+				  icom_acfg_baud[0],
+				  icom_acfg_baud[BAUD_TABLE_LIMIT]);
+	if (!baud)
+		baud = 9600;	/* B0 transition handled in rs_set_termios */
+
+	for (index = 0; index < BAUD_TABLE_LIMIT; index++) {
+		if (icom_acfg_baud[index] == baud) {
+			new_config3 = index;
+			break;
+		}
+	}
+
+	uart_update_timeout(port, cflag, baud);
+
+	/* CTS flow control flag and modem status interrupts */
+	tmp_byte = readb(&(icom_port->dram->HDLCConfigReg));
+	if (cflag & CRTSCTS)
+		tmp_byte |= HDLC_HDW_FLOW;
+	else
+		tmp_byte &= ~HDLC_HDW_FLOW;
+	writeb(tmp_byte, &(icom_port->dram->HDLCConfigReg));
+
+	/*
+	 * Set up parity check flag
+	 */
+	icom_port->read_status_mask = SA_FLAGS_OVERRUN | SA_FL_RCV_DONE;
+	if (iflag & INPCK)
+		icom_port->read_status_mask |=
+		    SA_FLAGS_FRAME_ERROR | SA_FLAGS_PARITY_ERROR;
+
+	if ((iflag & BRKINT) || (iflag & PARMRK))
+		icom_port->read_status_mask |= SA_FLAGS_BREAK_DET;
+
+	/*
+	 * Characters to ignore
+	 */
+	icom_port->ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		icom_port->ignore_status_mask |=
+		    SA_FLAGS_PARITY_ERROR | SA_FLAGS_FRAME_ERROR;
+	if (iflag & IGNBRK) {
+		icom_port->ignore_status_mask |= SA_FLAGS_BREAK_DET;
+		/*
+		 * If we're ignore parity and break indicators, ignore
+		 * overruns too.  (For real raw support).
+		 */
+		if (iflag & IGNPAR)
+			icom_port->ignore_status_mask |= SA_FLAGS_OVERRUN;
+	}
+
+	/*
+	 * !!! ignore all characters if CREAD is not set
+	 */
+	if ((cflag & CREAD) == 0)
+		icom_port->ignore_status_mask |= SA_FL_RCV_DONE;
+
+	/* Turn off Receiver to prepare for reset */
+	writeb(CMD_RCV_DISABLE, &icom_port->dram->CmdReg);
+
+	for (index = 0; index < 10; index++) {
+		if (readb(&icom_port->dram->PrevCmdReg) == 0x00) {
+			break;
+		}
+	}
+
+	/* clear all current buffers of data */
+	for (rcv_buff = 0; rcv_buff < NUM_RBUFFS; rcv_buff++) {
+		icom_port->statStg->rcv[rcv_buff].flags = 0;
+		icom_port->statStg->rcv[rcv_buff].leLength = 0;
+		icom_port->statStg->rcv[rcv_buff].WorkingLength =
+		    cpu_to_le16(RCV_BUFF_SZ);
+	}
+
+	for (xmit_buff = 0; xmit_buff < NUM_XBUFFS; xmit_buff++) {
+		icom_port->statStg->xmit[xmit_buff].flags = 0;
+	}
+
+	/* activate changes and start xmit and receiver here */
+	/* Enable the receiver */
+	writeb(new_config3, &(icom_port->dram->async_config3));
+	writeb(new_config2, &(icom_port->dram->async_config2));
+	tmp_byte = readb(&(icom_port->dram->HDLCConfigReg));
+	tmp_byte |= HDLC_PPP_PURE_ASYNC | HDLC_FF_FILL;
+	writeb(tmp_byte, &(icom_port->dram->HDLCConfigReg));
+	writeb(0x04, &(icom_port->dram->FlagFillIdleTimer));	/* 0.5 seconds */
+	writeb(0xFF, &(icom_port->dram->ier));	/* enable modem signal interrupts */
+
+	/* reset processor */
+	writeb(CMD_RESTART, &icom_port->dram->CmdReg);
+
+	for (index = 0; index < 10; index++) {
+		if (readb(&icom_port->dram->CmdReg) == 0x00) {
+			break;
+		}
+	}
+
+	/* Enable Transmitter and Receiver */
+	offset =
+	    (unsigned long) &icom_port->statStg->rcv[0] -
+	    (unsigned long) icom_port->statStg;
+	writel(icom_port->statStg_pci + offset,
+	       &icom_port->dram->RcvStatusAddr);
+	icom_port->next_rcv = 0;
+	*icom_port->xmitRestart = 0;
+	writel(icom_port->xmitRestart_pci,
+	       &icom_port->dram->XmitStatusAddr);
+	trace(icom_port, "XR_ENAB", 0);
+	writeb(CMD_XMIT_RCV_ENABLE, &icom_port->dram->CmdReg);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *icom_type(struct uart_port *port)
+{
+	return "icom";
+}
+
+static void icom_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_ICOM;
+}
+
+static const struct uart_ops icom_ops = {
+	.tx_empty = icom_tx_empty,
+	.set_mctrl = icom_set_mctrl,
+	.get_mctrl = icom_get_mctrl,
+	.stop_tx = icom_stop_tx,
+	.start_tx = icom_start_tx,
+	.send_xchar = icom_send_xchar,
+	.stop_rx = icom_stop_rx,
+	.break_ctl = icom_break,
+	.startup = icom_open,
+	.shutdown = icom_close,
+	.set_termios = icom_set_termios,
+	.type = icom_type,
+	.config_port = icom_config_port,
+};
+
+#define ICOM_CONSOLE NULL
+
+static struct uart_driver icom_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = ICOM_DRIVER_NAME,
+	.dev_name = "ttyA",
+	.major = ICOM_MAJOR,
+	.minor = ICOM_MINOR_START,
+	.nr = NR_PORTS,
+	.cons = ICOM_CONSOLE,
+};
+
+static int icom_init_ports(struct icom_adapter *icom_adapter)
+{
+	u32 subsystem_id = icom_adapter->subsystem_id;
+	int i;
+	struct icom_port *icom_port;
+
+	if (icom_adapter->version == ADAPTER_V1) {
+		icom_adapter->numb_ports = 2;
+
+		for (i = 0; i < 2; i++) {
+			icom_port = &icom_adapter->port_info[i];
+			icom_port->port = i;
+			icom_port->status = ICOM_PORT_ACTIVE;
+		}
+	} else {
+		if (subsystem_id == PCI_DEVICE_ID_IBM_ICOM_FOUR_PORT_MODEL) {
+			icom_adapter->numb_ports = 4;
+
+			for (i = 0; i < 4; i++) {
+				icom_port = &icom_adapter->port_info[i];
+
+				icom_port->port = i;
+				icom_port->status = ICOM_PORT_ACTIVE;
+			}
+		} else {
+			icom_adapter->numb_ports = 4;
+
+			icom_adapter->port_info[0].port = 0;
+			icom_adapter->port_info[0].status = ICOM_PORT_ACTIVE;
+			icom_adapter->port_info[1].status = ICOM_PORT_OFF;
+			icom_adapter->port_info[2].port = 2;
+			icom_adapter->port_info[2].status = ICOM_PORT_ACTIVE;
+			icom_adapter->port_info[3].status = ICOM_PORT_OFF;
+		}
+	}
+
+	return 0;
+}
+
+static void icom_port_active(struct icom_port *icom_port, struct icom_adapter *icom_adapter, int port_num)
+{
+	if (icom_adapter->version == ADAPTER_V1) {
+		icom_port->global_reg = icom_adapter->base_addr + 0x4000;
+		icom_port->int_reg = icom_adapter->base_addr +
+		    0x4004 + 2 - 2 * port_num;
+	} else {
+		icom_port->global_reg = icom_adapter->base_addr + 0x8000;
+		if (icom_port->port < 2)
+			icom_port->int_reg = icom_adapter->base_addr +
+			    0x8004 + 2 - 2 * icom_port->port;
+		else
+			icom_port->int_reg = icom_adapter->base_addr +
+			    0x8024 + 2 - 2 * (icom_port->port - 2);
+	}
+}
+static int icom_load_ports(struct icom_adapter *icom_adapter)
+{
+	struct icom_port *icom_port;
+	int port_num;
+
+	for (port_num = 0; port_num < icom_adapter->numb_ports; port_num++) {
+
+		icom_port = &icom_adapter->port_info[port_num];
+
+		if (icom_port->status == ICOM_PORT_ACTIVE) {
+			icom_port_active(icom_port, icom_adapter, port_num);
+			icom_port->dram = icom_adapter->base_addr +
+					0x2000 * icom_port->port;
+
+			icom_port->adapter = icom_adapter;
+
+			/* get port memory */
+			if (get_port_memory(icom_port) != 0) {
+				dev_err(&icom_port->adapter->pci_dev->dev,
+					"Memory allocation for port FAILED\n");
+			}
+		}
+	}
+	return 0;
+}
+
+static int icom_alloc_adapter(struct icom_adapter
+					**icom_adapter_ref)
+{
+	int adapter_count = 0;
+	struct icom_adapter *icom_adapter;
+	struct icom_adapter *cur_adapter_entry;
+
+	icom_adapter = kzalloc(sizeof(struct icom_adapter), GFP_KERNEL);
+
+	if (!icom_adapter) {
+		return -ENOMEM;
+	}
+
+	list_for_each_entry(cur_adapter_entry, &icom_adapter_head,
+			icom_adapter_entry) {
+		if (cur_adapter_entry->index != adapter_count) {
+			break;
+		}
+		adapter_count++;
+	}
+
+	icom_adapter->index = adapter_count;
+	list_add_tail(&icom_adapter->icom_adapter_entry,
+			&cur_adapter_entry->icom_adapter_entry);
+
+	*icom_adapter_ref = icom_adapter;
+	return 0;
+}
+
+static void icom_free_adapter(struct icom_adapter *icom_adapter)
+{
+	list_del(&icom_adapter->icom_adapter_entry);
+	kfree(icom_adapter);
+}
+
+static void icom_kref_release(struct kref *kref)
+{
+	struct icom_adapter *icom_adapter = container_of(kref,
+			struct icom_adapter, kref);
+	struct icom_port *icom_port;
+	int index;
+
+	for (index = 0; index < icom_adapter->numb_ports; index++) {
+		icom_port = &icom_adapter->port_info[index];
+
+		if (icom_port->status == ICOM_PORT_ACTIVE) {
+			dev_info(&icom_adapter->pci_dev->dev,
+				 "Device removed\n");
+
+			uart_remove_one_port(&icom_uart_driver,
+					     &icom_port->uart_port);
+
+			/* be sure that DTR and RTS are dropped */
+			writeb(0x00, &icom_port->dram->osr);
+
+			/* Wait 0.1 Sec for simple Init to complete */
+			msleep(100);
+
+			/* Stop proccessor */
+			stop_processor(icom_port);
+
+			free_port_memory(icom_port);
+		}
+	}
+
+	free_irq(icom_adapter->pci_dev->irq, (void *) icom_adapter);
+	iounmap(icom_adapter->base_addr);
+	pci_release_regions(icom_adapter->pci_dev);
+	icom_free_adapter(icom_adapter);
+}
+
+static int icom_probe(struct pci_dev *dev,
+				const struct pci_device_id *ent)
+{
+	int index;
+	unsigned int command_reg;
+	int retval;
+	struct icom_adapter *icom_adapter;
+	struct icom_port *icom_port;
+
+	retval = pci_enable_device(dev);
+	if (retval) {
+		dev_err(&dev->dev, "Device enable FAILED\n");
+		return retval;
+	}
+
+	retval = pci_request_regions(dev, "icom");
+	if (retval) {
+		 dev_err(&dev->dev, "pci_request_regions FAILED\n");
+		 pci_disable_device(dev);
+		 return retval;
+	 }
+
+	pci_set_master(dev);
+
+	retval = pci_read_config_dword(dev, PCI_COMMAND, &command_reg);
+	if (retval) {
+		dev_err(&dev->dev, "PCI Config read FAILED\n");
+		goto probe_exit0;
+	}
+
+	pci_write_config_dword(dev, PCI_COMMAND,
+		command_reg | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER
+ 		| PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
+
+	if (ent->driver_data == ADAPTER_V1) {
+		pci_write_config_dword(dev, 0x44, 0x8300830A);
+	} else {
+		pci_write_config_dword(dev, 0x44, 0x42004200);
+		pci_write_config_dword(dev, 0x48, 0x42004200);
+	}
+
+
+	retval = icom_alloc_adapter(&icom_adapter);
+	if (retval) {
+		 dev_err(&dev->dev, "icom_alloc_adapter FAILED\n");
+		 retval = -EIO;
+		 goto probe_exit0;
+	}
+
+	icom_adapter->base_addr_pci = pci_resource_start(dev, 0);
+	icom_adapter->pci_dev = dev;
+	icom_adapter->version = ent->driver_data;
+	icom_adapter->subsystem_id = ent->subdevice;
+
+
+	retval = icom_init_ports(icom_adapter);
+	if (retval) {
+		dev_err(&dev->dev, "Port configuration failed\n");
+		goto probe_exit1;
+	}
+
+	icom_adapter->base_addr = pci_ioremap_bar(dev, 0);
+
+	if (!icom_adapter->base_addr) {
+		retval = -ENOMEM;
+		goto probe_exit1;
+	}
+
+	 /* save off irq and request irq line */
+	 retval = request_irq(dev->irq, icom_interrupt, IRQF_SHARED, ICOM_DRIVER_NAME, (void *)icom_adapter);
+	 if (retval) {
+		  goto probe_exit2;
+	 }
+
+	retval = icom_load_ports(icom_adapter);
+
+	for (index = 0; index < icom_adapter->numb_ports; index++) {
+		icom_port = &icom_adapter->port_info[index];
+
+		if (icom_port->status == ICOM_PORT_ACTIVE) {
+			icom_port->uart_port.irq = icom_port->adapter->pci_dev->irq;
+			icom_port->uart_port.type = PORT_ICOM;
+			icom_port->uart_port.iotype = UPIO_MEM;
+			icom_port->uart_port.membase =
+				(unsigned char __iomem *)icom_adapter->base_addr_pci;
+			icom_port->uart_port.fifosize = 16;
+			icom_port->uart_port.ops = &icom_ops;
+			icom_port->uart_port.line =
+		        icom_port->port + icom_adapter->index * 4;
+			if (uart_add_one_port (&icom_uart_driver, &icom_port->uart_port)) {
+				icom_port->status = ICOM_PORT_OFF;
+				dev_err(&dev->dev, "Device add failed\n");
+			 } else
+				dev_info(&dev->dev, "Device added\n");
+		}
+	}
+
+	kref_init(&icom_adapter->kref);
+	return 0;
+
+probe_exit2:
+	iounmap(icom_adapter->base_addr);
+probe_exit1:
+	icom_free_adapter(icom_adapter);
+
+probe_exit0:
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+
+	return retval;
+}
+
+static void icom_remove(struct pci_dev *dev)
+{
+	struct icom_adapter *icom_adapter;
+
+	list_for_each_entry(icom_adapter, &icom_adapter_head,
+			icom_adapter_entry) {
+		if (icom_adapter->pci_dev == dev) {
+			kref_put(&icom_adapter->kref, icom_kref_release);
+			return;
+		}
+	}
+
+	dev_err(&dev->dev, "Unable to find device to remove\n");
+}
+
+static struct pci_driver icom_pci_driver = {
+	.name = ICOM_DRIVER_NAME,
+	.id_table = icom_pci_table,
+	.probe = icom_probe,
+	.remove = icom_remove,
+};
+
+static int __init icom_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&icom_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = pci_register_driver(&icom_pci_driver);
+
+	if (ret < 0)
+		uart_unregister_driver(&icom_uart_driver);
+
+	return ret;
+}
+
+static void __exit icom_exit(void)
+{
+	pci_unregister_driver(&icom_pci_driver);
+	uart_unregister_driver(&icom_uart_driver);
+}
+
+module_init(icom_init);
+module_exit(icom_exit);
+
+MODULE_AUTHOR("Michael Anderson <mjanders@us.ibm.com>");
+MODULE_DESCRIPTION("IBM iSeries Serial IOA driver");
+MODULE_LICENSE("GPL");
+MODULE_FIRMWARE("icom_call_setup.bin");
+MODULE_FIRMWARE("icom_res_dce.bin");
+MODULE_FIRMWARE("icom_asc.bin");
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
new file mode 100644
index 000000000..2fbb9b597
--- /dev/null
+++ b/drivers/tty/serial/imx.c
@@ -0,0 +1,2672 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Motorola/Freescale IMX serial ports
+ *
+ * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ * Author: Sascha Hauer <sascha@saschahauer.de>
+ * Copyright (C) 2004 Pengutronix
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/rational.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/irq.h>
+#include <linux/dma/imx-dma.h>
+
+#include "serial_mctrl_gpio.h"
+
+/* Register definitions */
+#define URXD0 0x0  /* Receiver Register */
+#define URTX0 0x40 /* Transmitter Register */
+#define UCR1  0x80 /* Control Register 1 */
+#define UCR2  0x84 /* Control Register 2 */
+#define UCR3  0x88 /* Control Register 3 */
+#define UCR4  0x8c /* Control Register 4 */
+#define UFCR  0x90 /* FIFO Control Register */
+#define USR1  0x94 /* Status Register 1 */
+#define USR2  0x98 /* Status Register 2 */
+#define UESC  0x9c /* Escape Character Register */
+#define UTIM  0xa0 /* Escape Timer Register */
+#define UBIR  0xa4 /* BRM Incremental Register */
+#define UBMR  0xa8 /* BRM Modulator Register */
+#define UBRC  0xac /* Baud Rate Count Register */
+#define IMX21_ONEMS 0xb0 /* One Millisecond register */
+#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
+#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
+
+/* UART Control Register Bit Fields.*/
+#define URXD_DUMMY_READ (1<<16)
+#define URXD_CHARRDY	(1<<15)
+#define URXD_ERR	(1<<14)
+#define URXD_OVRRUN	(1<<13)
+#define URXD_FRMERR	(1<<12)
+#define URXD_BRK	(1<<11)
+#define URXD_PRERR	(1<<10)
+#define URXD_RX_DATA	(0xFF<<0)
+#define UCR1_ADEN	(1<<15) /* Auto detect interrupt */
+#define UCR1_ADBR	(1<<14) /* Auto detect baud rate */
+#define UCR1_TRDYEN	(1<<13) /* Transmitter ready interrupt enable */
+#define UCR1_IDEN	(1<<12) /* Idle condition interrupt */
+#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
+#define UCR1_RRDYEN	(1<<9)	/* Recv ready interrupt enable */
+#define UCR1_RXDMAEN	(1<<8)	/* Recv ready DMA enable */
+#define UCR1_IREN	(1<<7)	/* Infrared interface enable */
+#define UCR1_TXMPTYEN	(1<<6)	/* Transimitter empty interrupt enable */
+#define UCR1_RTSDEN	(1<<5)	/* RTS delta interrupt enable */
+#define UCR1_SNDBRK	(1<<4)	/* Send break */
+#define UCR1_TXDMAEN	(1<<3)	/* Transmitter ready DMA enable */
+#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
+#define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
+#define UCR1_DOZE	(1<<1)	/* Doze */
+#define UCR1_UARTEN	(1<<0)	/* UART enabled */
+#define UCR2_ESCI	(1<<15)	/* Escape seq interrupt enable */
+#define UCR2_IRTS	(1<<14)	/* Ignore RTS pin */
+#define UCR2_CTSC	(1<<13)	/* CTS pin control */
+#define UCR2_CTS	(1<<12)	/* Clear to send */
+#define UCR2_ESCEN	(1<<11)	/* Escape enable */
+#define UCR2_PREN	(1<<8)	/* Parity enable */
+#define UCR2_PROE	(1<<7)	/* Parity odd/even */
+#define UCR2_STPB	(1<<6)	/* Stop */
+#define UCR2_WS		(1<<5)	/* Word size */
+#define UCR2_RTSEN	(1<<4)	/* Request to send interrupt enable */
+#define UCR2_ATEN	(1<<3)	/* Aging Timer Enable */
+#define UCR2_TXEN	(1<<2)	/* Transmitter enabled */
+#define UCR2_RXEN	(1<<1)	/* Receiver enabled */
+#define UCR2_SRST	(1<<0)	/* SW reset */
+#define UCR3_DTREN	(1<<13) /* DTR interrupt enable */
+#define UCR3_PARERREN	(1<<12) /* Parity enable */
+#define UCR3_FRAERREN	(1<<11) /* Frame error interrupt enable */
+#define UCR3_DSR	(1<<10) /* Data set ready */
+#define UCR3_DCD	(1<<9)	/* Data carrier detect */
+#define UCR3_RI		(1<<8)	/* Ring indicator */
+#define UCR3_ADNIMP	(1<<7)	/* Autobaud Detection Not Improved */
+#define UCR3_RXDSEN	(1<<6)	/* Receive status interrupt enable */
+#define UCR3_AIRINTEN	(1<<5)	/* Async IR wake interrupt enable */
+#define UCR3_AWAKEN	(1<<4)	/* Async wake interrupt enable */
+#define UCR3_DTRDEN	(1<<3)	/* Data Terminal Ready Delta Enable. */
+#define IMX21_UCR3_RXDMUXSEL	(1<<2)	/* RXD Muxed Input Select */
+#define UCR3_INVT	(1<<1)	/* Inverted Infrared transmission */
+#define UCR3_BPEN	(1<<0)	/* Preset registers enable */
+#define UCR4_CTSTL_SHF	10	/* CTS trigger level shift */
+#define UCR4_CTSTL_MASK	0x3F	/* CTS trigger is 6 bits wide */
+#define UCR4_INVR	(1<<9)	/* Inverted infrared reception */
+#define UCR4_ENIRI	(1<<8)	/* Serial infrared interrupt enable */
+#define UCR4_WKEN	(1<<7)	/* Wake interrupt enable */
+#define UCR4_REF16	(1<<6)	/* Ref freq 16 MHz */
+#define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
+#define UCR4_IRSC	(1<<5)	/* IR special case */
+#define UCR4_TCEN	(1<<3)	/* Transmit complete interrupt enable */
+#define UCR4_BKEN	(1<<2)	/* Break condition interrupt enable */
+#define UCR4_OREN	(1<<1)	/* Receiver overrun interrupt enable */
+#define UCR4_DREN	(1<<0)	/* Recv data ready interrupt enable */
+#define UFCR_RXTL_SHF	0	/* Receiver trigger level shift */
+#define UFCR_DCEDTE	(1<<6)	/* DCE/DTE mode select */
+#define UFCR_RFDIV	(7<<7)	/* Reference freq divider mask */
+#define UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
+#define UFCR_TXTL_SHF	10	/* Transmitter trigger level shift */
+#define USR1_PARITYERR	(1<<15) /* Parity error interrupt flag */
+#define USR1_RTSS	(1<<14) /* RTS pin status */
+#define USR1_TRDY	(1<<13) /* Transmitter ready interrupt/dma flag */
+#define USR1_RTSD	(1<<12) /* RTS delta */
+#define USR1_ESCF	(1<<11) /* Escape seq interrupt flag */
+#define USR1_FRAMERR	(1<<10) /* Frame error interrupt flag */
+#define USR1_RRDY	(1<<9)	 /* Receiver ready interrupt/dma flag */
+#define USR1_AGTIM	(1<<8)	 /* Ageing timer interrupt flag */
+#define USR1_DTRD	(1<<7)	 /* DTR Delta */
+#define USR1_RXDS	 (1<<6)	 /* Receiver idle interrupt flag */
+#define USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
+#define USR1_AWAKE	 (1<<4)	 /* Aysnc wake interrupt flag */
+#define USR2_ADET	 (1<<15) /* Auto baud rate detect complete */
+#define USR2_TXFE	 (1<<14) /* Transmit buffer FIFO empty */
+#define USR2_DTRF	 (1<<13) /* DTR edge interrupt flag */
+#define USR2_IDLE	 (1<<12) /* Idle condition */
+#define USR2_RIDELT	 (1<<10) /* Ring Interrupt Delta */
+#define USR2_RIIN	 (1<<9)	 /* Ring Indicator Input */
+#define USR2_IRINT	 (1<<8)	 /* Serial infrared interrupt flag */
+#define USR2_WAKE	 (1<<7)	 /* Wake */
+#define USR2_DCDIN	 (1<<5)	 /* Data Carrier Detect Input */
+#define USR2_RTSF	 (1<<4)	 /* RTS edge interrupt flag */
+#define USR2_TXDC	 (1<<3)	 /* Transmitter complete */
+#define USR2_BRCD	 (1<<2)	 /* Break condition */
+#define USR2_ORE	(1<<1)	 /* Overrun error */
+#define USR2_RDR	(1<<0)	 /* Recv data ready */
+#define UTS_FRCPERR	(1<<13) /* Force parity error */
+#define UTS_LOOP	(1<<12)	 /* Loop tx and rx */
+#define UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
+#define UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
+#define UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
+#define UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
+#define UTS_SOFTRST	 (1<<0)	 /* Software reset */
+
+/* We've been assigned a range on the "Low-density serial ports" major */
+#define SERIAL_IMX_MAJOR	207
+#define MINOR_START		16
+#define DEV_NAME		"ttymxc"
+
+/*
+ * This determines how often we check the modem status signals
+ * for any change.  They generally aren't connected to an IRQ
+ * so we have to poll them.  We also check immediately before
+ * filling the TX fifo incase CTS has been dropped.
+ */
+#define MCTRL_TIMEOUT	(250*HZ/1000)
+
+#define DRIVER_NAME "IMX-uart"
+
+#define UART_NR 8
+
+/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
+enum imx_uart_type {
+	IMX1_UART,
+	IMX21_UART,
+	IMX53_UART,
+	IMX6Q_UART,
+};
+
+/* device type dependent stuff */
+struct imx_uart_data {
+	unsigned uts_reg;
+	enum imx_uart_type devtype;
+};
+
+enum imx_tx_state {
+	OFF,
+	WAIT_AFTER_RTS,
+	SEND,
+	WAIT_AFTER_SEND,
+};
+
+struct imx_port {
+	struct uart_port	port;
+	struct timer_list	timer;
+	unsigned int		old_status;
+	unsigned int		have_rtscts:1;
+	unsigned int		have_rtsgpio:1;
+	unsigned int		dte_mode:1;
+	unsigned int		inverted_tx:1;
+	unsigned int		inverted_rx:1;
+	struct clk		*clk_ipg;
+	struct clk		*clk_per;
+	const struct imx_uart_data *devdata;
+
+	struct mctrl_gpios *gpios;
+
+	/* counter to stop 0xff flood */
+	int idle_counter;
+
+	/* DMA fields */
+	unsigned int		dma_is_enabled:1;
+	unsigned int		dma_is_rxing:1;
+	unsigned int		dma_is_txing:1;
+	struct dma_chan		*dma_chan_rx, *dma_chan_tx;
+	struct scatterlist	rx_sgl, tx_sgl[2];
+	void			*rx_buf;
+	struct circ_buf		rx_ring;
+	unsigned int		rx_buf_size;
+	unsigned int		rx_period_length;
+	unsigned int		rx_periods;
+	dma_cookie_t		rx_cookie;
+	unsigned int		tx_bytes;
+	unsigned int		dma_tx_nents;
+	unsigned int            saved_reg[10];
+	bool			context_saved;
+
+	enum imx_tx_state	tx_state;
+	struct hrtimer		trigger_start_tx;
+	struct hrtimer		trigger_stop_tx;
+};
+
+struct imx_port_ucrs {
+	unsigned int	ucr1;
+	unsigned int	ucr2;
+	unsigned int	ucr3;
+};
+
+static struct imx_uart_data imx_uart_devdata[] = {
+	[IMX1_UART] = {
+		.uts_reg = IMX1_UTS,
+		.devtype = IMX1_UART,
+	},
+	[IMX21_UART] = {
+		.uts_reg = IMX21_UTS,
+		.devtype = IMX21_UART,
+	},
+	[IMX53_UART] = {
+		.uts_reg = IMX21_UTS,
+		.devtype = IMX53_UART,
+	},
+	[IMX6Q_UART] = {
+		.uts_reg = IMX21_UTS,
+		.devtype = IMX6Q_UART,
+	},
+};
+
+static const struct of_device_id imx_uart_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
+	{ .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
+	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
+	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
+
+static inline void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
+{
+	writel(val, sport->port.membase + offset);
+}
+
+static inline u32 imx_uart_readl(struct imx_port *sport, u32 offset)
+{
+	return readl(sport->port.membase + offset);
+}
+
+static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
+{
+	return sport->devdata->uts_reg;
+}
+
+static inline int imx_uart_is_imx1(struct imx_port *sport)
+{
+	return sport->devdata->devtype == IMX1_UART;
+}
+
+/*
+ * Save and restore functions for UCR1, UCR2 and UCR3 registers
+ */
+#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
+static void imx_uart_ucrs_save(struct imx_port *sport,
+			       struct imx_port_ucrs *ucr)
+{
+	/* save control registers */
+	ucr->ucr1 = imx_uart_readl(sport, UCR1);
+	ucr->ucr2 = imx_uart_readl(sport, UCR2);
+	ucr->ucr3 = imx_uart_readl(sport, UCR3);
+}
+
+static void imx_uart_ucrs_restore(struct imx_port *sport,
+				  struct imx_port_ucrs *ucr)
+{
+	/* restore control registers */
+	imx_uart_writel(sport, ucr->ucr1, UCR1);
+	imx_uart_writel(sport, ucr->ucr2, UCR2);
+	imx_uart_writel(sport, ucr->ucr3, UCR3);
+}
+#endif
+
+/* called with port.lock taken and irqs caller dependent */
+static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
+{
+	*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
+
+	mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
+}
+
+/* called with port.lock taken and irqs caller dependent */
+static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
+{
+	*ucr2 &= ~UCR2_CTSC;
+	*ucr2 |= UCR2_CTS;
+
+	mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
+}
+
+static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
+{
+       hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_soft_reset(struct imx_port *sport)
+{
+	int i = 10;
+	u32 ucr2, ubir, ubmr, uts;
+
+	/*
+	 * According to the Reference Manual description of the UART SRST bit:
+	 *
+	 * "Reset the transmit and receive state machines,
+	 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
+	 * and UTS[6-3]".
+	 *
+	 * We don't need to restore the old values from USR1, USR2, URXD and
+	 * UTXD. UBRC is read only, so only save/restore the other three
+	 * registers.
+	 */
+	ubir = imx_uart_readl(sport, UBIR);
+	ubmr = imx_uart_readl(sport, UBMR);
+	uts = imx_uart_readl(sport, IMX21_UTS);
+
+	ucr2 = imx_uart_readl(sport, UCR2);
+	imx_uart_writel(sport, ucr2 & ~UCR2_SRST, UCR2);
+
+	while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
+		udelay(1);
+
+	/* Restore the registers */
+	imx_uart_writel(sport, ubir, UBIR);
+	imx_uart_writel(sport, ubmr, UBMR);
+	imx_uart_writel(sport, uts, IMX21_UTS);
+
+	sport->idle_counter = 0;
+}
+
+static void imx_uart_disable_loopback_rs485(struct imx_port *sport)
+{
+	unsigned int uts;
+
+	/* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
+	uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
+	uts &= ~UTS_LOOP;
+	imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_start_rx(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned int ucr1, ucr2;
+
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr2 = imx_uart_readl(sport, UCR2);
+
+	ucr2 |= UCR2_RXEN;
+
+	if (sport->dma_is_enabled) {
+		ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
+	} else {
+		ucr1 |= UCR1_RRDYEN;
+		ucr2 |= UCR2_ATEN;
+	}
+
+	/* Write UCR2 first as it includes RXEN */
+	imx_uart_writel(sport, ucr2, UCR2);
+	imx_uart_writel(sport, ucr1, UCR1);
+	imx_uart_disable_loopback_rs485(sport);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_stop_tx(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	u32 ucr1, ucr4, usr2;
+
+	if (sport->tx_state == OFF)
+		return;
+
+	/*
+	 * We are maybe in the SMP context, so if the DMA TX thread is running
+	 * on other cpu, we have to wait for it to finish.
+	 */
+	if (sport->dma_is_txing)
+		return;
+
+	ucr1 = imx_uart_readl(sport, UCR1);
+	imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
+
+	ucr4 = imx_uart_readl(sport, UCR4);
+	usr2 = imx_uart_readl(sport, USR2);
+	if ((!(usr2 & USR2_TXDC)) && (ucr4 & UCR4_TCEN)) {
+		/* The shifter is still busy, so retry once TC triggers */
+		return;
+	}
+
+	ucr4 &= ~UCR4_TCEN;
+	imx_uart_writel(sport, ucr4, UCR4);
+
+	/* in rs485 mode disable transmitter */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if (sport->tx_state == SEND) {
+			sport->tx_state = WAIT_AFTER_SEND;
+
+			if (port->rs485.delay_rts_after_send > 0) {
+				start_hrtimer_ms(&sport->trigger_stop_tx,
+					 port->rs485.delay_rts_after_send);
+				return;
+			}
+
+			/* continue without any delay */
+		}
+
+		if (sport->tx_state == WAIT_AFTER_RTS ||
+		    sport->tx_state == WAIT_AFTER_SEND) {
+			u32 ucr2;
+
+			hrtimer_try_to_cancel(&sport->trigger_start_tx);
+
+			ucr2 = imx_uart_readl(sport, UCR2);
+			if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+				imx_uart_rts_active(sport, &ucr2);
+			else
+				imx_uart_rts_inactive(sport, &ucr2);
+			imx_uart_writel(sport, ucr2, UCR2);
+
+			if (!port->rs485_rx_during_tx_gpio)
+				imx_uart_start_rx(port);
+
+			sport->tx_state = OFF;
+		}
+	} else {
+		sport->tx_state = OFF;
+	}
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_stop_rx(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	u32 ucr1, ucr2, ucr4, uts;
+
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr2 = imx_uart_readl(sport, UCR2);
+	ucr4 = imx_uart_readl(sport, UCR4);
+
+	if (sport->dma_is_enabled) {
+		ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
+	} else {
+		ucr1 &= ~UCR1_RRDYEN;
+		ucr2 &= ~UCR2_ATEN;
+		ucr4 &= ~UCR4_OREN;
+	}
+	imx_uart_writel(sport, ucr1, UCR1);
+	imx_uart_writel(sport, ucr4, UCR4);
+
+	/* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
+	if (port->rs485.flags & SER_RS485_ENABLED &&
+	    port->rs485.flags & SER_RS485_RTS_ON_SEND &&
+	    sport->have_rtscts && !sport->have_rtsgpio) {
+		uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
+		uts |= UTS_LOOP;
+		imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+		ucr2 |= UCR2_RXEN;
+	} else {
+		ucr2 &= ~UCR2_RXEN;
+	}
+
+	imx_uart_writel(sport, ucr2, UCR2);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_enable_ms(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	mod_timer(&sport->timer, jiffies);
+
+	mctrl_gpio_enable_ms(sport->gpios);
+}
+
+static void imx_uart_dma_tx(struct imx_port *sport);
+
+/* called with port.lock taken and irqs off */
+static inline void imx_uart_transmit_buffer(struct imx_port *sport)
+{
+	struct circ_buf *xmit = &sport->port.state->xmit;
+
+	if (sport->port.x_char) {
+		/* Send next char */
+		imx_uart_writel(sport, sport->port.x_char, URTX0);
+		sport->port.icount.tx++;
+		sport->port.x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
+		imx_uart_stop_tx(&sport->port);
+		return;
+	}
+
+	if (sport->dma_is_enabled) {
+		u32 ucr1;
+		/*
+		 * We've just sent a X-char Ensure the TX DMA is enabled
+		 * and the TX IRQ is disabled.
+		 **/
+		ucr1 = imx_uart_readl(sport, UCR1);
+		ucr1 &= ~UCR1_TRDYEN;
+		if (sport->dma_is_txing) {
+			ucr1 |= UCR1_TXDMAEN;
+			imx_uart_writel(sport, ucr1, UCR1);
+		} else {
+			imx_uart_writel(sport, ucr1, UCR1);
+			imx_uart_dma_tx(sport);
+		}
+
+		return;
+	}
+
+	while (!uart_circ_empty(xmit) &&
+	       !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
+		/* send xmit->buf[xmit->tail]
+		 * out the port here */
+		imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
+		uart_xmit_advance(&sport->port, 1);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+	if (uart_circ_empty(xmit))
+		imx_uart_stop_tx(&sport->port);
+}
+
+static void imx_uart_dma_tx_callback(void *data)
+{
+	struct imx_port *sport = data;
+	struct scatterlist *sgl = &sport->tx_sgl[0];
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	unsigned long flags;
+	u32 ucr1;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr1 &= ~UCR1_TXDMAEN;
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	uart_xmit_advance(&sport->port, sport->tx_bytes);
+
+	dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
+
+	sport->dma_is_txing = 0;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
+		imx_uart_dma_tx(sport);
+	else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
+		u32 ucr4 = imx_uart_readl(sport, UCR4);
+		ucr4 |= UCR4_TCEN;
+		imx_uart_writel(sport, ucr4, UCR4);
+	}
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_dma_tx(struct imx_port *sport)
+{
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	struct scatterlist *sgl = sport->tx_sgl;
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan	*chan = sport->dma_chan_tx;
+	struct device *dev = sport->port.dev;
+	u32 ucr1, ucr4;
+	int ret;
+
+	if (sport->dma_is_txing)
+		return;
+
+	ucr4 = imx_uart_readl(sport, UCR4);
+	ucr4 &= ~UCR4_TCEN;
+	imx_uart_writel(sport, ucr4, UCR4);
+
+	sport->tx_bytes = uart_circ_chars_pending(xmit);
+
+	if (xmit->tail < xmit->head || xmit->head == 0) {
+		sport->dma_tx_nents = 1;
+		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
+	} else {
+		sport->dma_tx_nents = 2;
+		sg_init_table(sgl, 2);
+		sg_set_buf(sgl, xmit->buf + xmit->tail,
+				UART_XMIT_SIZE - xmit->tail);
+		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
+	}
+
+	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+	if (ret == 0) {
+		dev_err(dev, "DMA mapping error for TX.\n");
+		return;
+	}
+	desc = dmaengine_prep_slave_sg(chan, sgl, ret,
+					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
+			     DMA_TO_DEVICE);
+		dev_err(dev, "We cannot prepare for the TX slave dma!\n");
+		return;
+	}
+	desc->callback = imx_uart_dma_tx_callback;
+	desc->callback_param = sport;
+
+	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
+			uart_circ_chars_pending(xmit));
+
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr1 |= UCR1_TXDMAEN;
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	/* fire it */
+	sport->dma_is_txing = 1;
+	dmaengine_submit(desc);
+	dma_async_issue_pending(chan);
+	return;
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_start_tx(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	u32 ucr1;
+
+	if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
+		return;
+
+	/*
+	 * We cannot simply do nothing here if sport->tx_state == SEND already
+	 * because UCR1_TXMPTYEN might already have been cleared in
+	 * imx_uart_stop_tx(), but tx_state is still SEND.
+	 */
+
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if (sport->tx_state == OFF) {
+			u32 ucr2 = imx_uart_readl(sport, UCR2);
+			if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
+				imx_uart_rts_active(sport, &ucr2);
+			else
+				imx_uart_rts_inactive(sport, &ucr2);
+			imx_uart_writel(sport, ucr2, UCR2);
+
+			if (!(port->rs485.flags & SER_RS485_RX_DURING_TX) &&
+			    !port->rs485_rx_during_tx_gpio)
+				imx_uart_stop_rx(port);
+
+			sport->tx_state = WAIT_AFTER_RTS;
+
+			if (port->rs485.delay_rts_before_send > 0) {
+				start_hrtimer_ms(&sport->trigger_start_tx,
+					 port->rs485.delay_rts_before_send);
+				return;
+			}
+
+			/* continue without any delay */
+		}
+
+		if (sport->tx_state == WAIT_AFTER_SEND
+		    || sport->tx_state == WAIT_AFTER_RTS) {
+
+			hrtimer_try_to_cancel(&sport->trigger_stop_tx);
+
+			/*
+			 * Enable transmitter and shifter empty irq only if DMA
+			 * is off.  In the DMA case this is done in the
+			 * tx-callback.
+			 */
+			if (!sport->dma_is_enabled) {
+				u32 ucr4 = imx_uart_readl(sport, UCR4);
+				ucr4 |= UCR4_TCEN;
+				imx_uart_writel(sport, ucr4, UCR4);
+			}
+
+			sport->tx_state = SEND;
+		}
+	} else {
+		sport->tx_state = SEND;
+	}
+
+	if (!sport->dma_is_enabled) {
+		ucr1 = imx_uart_readl(sport, UCR1);
+		imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
+	}
+
+	if (sport->dma_is_enabled) {
+		if (sport->port.x_char) {
+			/* We have X-char to send, so enable TX IRQ and
+			 * disable TX DMA to let TX interrupt to send X-char */
+			ucr1 = imx_uart_readl(sport, UCR1);
+			ucr1 &= ~UCR1_TXDMAEN;
+			ucr1 |= UCR1_TRDYEN;
+			imx_uart_writel(sport, ucr1, UCR1);
+			return;
+		}
+
+		if (!uart_circ_empty(&port->state->xmit) &&
+		    !uart_tx_stopped(port))
+			imx_uart_dma_tx(sport);
+		return;
+	}
+}
+
+static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	u32 usr1;
+
+	imx_uart_writel(sport, USR1_RTSD, USR1);
+	usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
+	uart_handle_cts_change(&sport->port, usr1);
+	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	irqreturn_t ret;
+
+	spin_lock(&sport->port.lock);
+
+	ret = __imx_uart_rtsint(irq, dev_id);
+
+	spin_unlock(&sport->port.lock);
+
+	return ret;
+}
+
+static irqreturn_t imx_uart_txint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+
+	spin_lock(&sport->port.lock);
+	imx_uart_transmit_buffer(sport);
+	spin_unlock(&sport->port.lock);
+	return IRQ_HANDLED;
+}
+
+/* Check if hardware Rx flood is in progress, and issue soft reset to stop it.
+ * This is to be called from Rx ISRs only when some bytes were actually
+ * received.
+ *
+ * A way to reproduce the flood (checked on iMX6SX) is: open iMX UART at 9600
+ * 8N1, and from external source send 0xf0 char at 115200 8N1. In about 90% of
+ * cases this starts a flood of "receiving" of 0xff characters by the iMX6 UART
+ * that is terminated by any activity on RxD line, or could be stopped by
+ * issuing soft reset to the UART (just stop/start of RX does not help). Note
+ * that what we do here is sending isolated start bit about 2.4 times shorter
+ * than it is to be on UART configured baud rate.
+ */
+static void imx_uart_check_flood(struct imx_port *sport, u32 usr2)
+{
+	/* To detect hardware 0xff flood we monitor RxD line between RX
+	 * interrupts to isolate "receiving" of char(s) with no activity
+	 * on RxD line, that'd never happen on actual data transfers.
+	 *
+	 * We use USR2_WAKE bit to check for activity on RxD line, but we have a
+	 * race here if we clear USR2_WAKE when receiving of a char is in
+	 * progress, so we might get RX interrupt later with USR2_WAKE bit
+	 * cleared. Note though that as we don't try to clear USR2_WAKE when we
+	 * detected no activity, this race may hide actual activity only once.
+	 *
+	 * Yet another case where receive interrupt may occur without RxD
+	 * activity is expiration of aging timer, so we consider this as well.
+	 *
+	 * We use 'idle_counter' to ensure that we got at least so many RX
+	 * interrupts without any detected activity on RxD line. 2 cases
+	 * described plus 1 to be on the safe side gives us a margin of 3,
+	 * below. In practice I was not able to produce a false positive to
+	 * induce soft reset at regular data transfers even using 1 as the
+	 * margin, so 3 is actually very strong.
+	 *
+	 * We count interrupts, not chars in 'idle-counter' for simplicity.
+	 */
+
+	if (usr2 & USR2_WAKE) {
+		imx_uart_writel(sport, USR2_WAKE, USR2);
+		sport->idle_counter = 0;
+	} else if (++sport->idle_counter > 3) {
+		dev_warn(sport->port.dev, "RX flood detected: soft reset.");
+		imx_uart_soft_reset(sport); /* also clears 'sport->idle_counter' */
+	}
+}
+
+static irqreturn_t __imx_uart_rxint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	struct tty_port *port = &sport->port.state->port;
+	u32 usr2, rx;
+
+	/* If we received something, check for 0xff flood */
+	usr2 = imx_uart_readl(sport, USR2);
+	if (usr2 & USR2_RDR)
+		imx_uart_check_flood(sport, usr2);
+
+	while ((rx = imx_uart_readl(sport, URXD0)) & URXD_CHARRDY) {
+		unsigned int flg = TTY_NORMAL;
+		sport->port.icount.rx++;
+
+		if (unlikely(rx & URXD_ERR)) {
+			if (rx & URXD_BRK) {
+				sport->port.icount.brk++;
+				if (uart_handle_break(&sport->port))
+					continue;
+			}
+			else if (rx & URXD_PRERR)
+				sport->port.icount.parity++;
+			else if (rx & URXD_FRMERR)
+				sport->port.icount.frame++;
+			if (rx & URXD_OVRRUN)
+				sport->port.icount.overrun++;
+
+			if (rx & sport->port.ignore_status_mask)
+				continue;
+
+			rx &= (sport->port.read_status_mask | 0xFF);
+
+			if (rx & URXD_BRK)
+				flg = TTY_BREAK;
+			else if (rx & URXD_PRERR)
+				flg = TTY_PARITY;
+			else if (rx & URXD_FRMERR)
+				flg = TTY_FRAME;
+			if (rx & URXD_OVRRUN)
+				flg = TTY_OVERRUN;
+
+			sport->port.sysrq = 0;
+		} else if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) {
+			continue;
+		}
+
+		if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
+			continue;
+
+		if (tty_insert_flip_char(port, rx, flg) == 0)
+			sport->port.icount.buf_overrun++;
+	}
+
+	tty_flip_buffer_push(port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	irqreturn_t ret;
+
+	spin_lock(&sport->port.lock);
+
+	ret = __imx_uart_rxint(irq, dev_id);
+
+	spin_unlock(&sport->port.lock);
+
+	return ret;
+}
+
+static void imx_uart_clear_rx_errors(struct imx_port *sport);
+
+/*
+ * We have a modem side uart, so the meanings of RTS and CTS are inverted.
+ */
+static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
+{
+	unsigned int tmp = TIOCM_DSR;
+	unsigned usr1 = imx_uart_readl(sport, USR1);
+	unsigned usr2 = imx_uart_readl(sport, USR2);
+
+	if (usr1 & USR1_RTSS)
+		tmp |= TIOCM_CTS;
+
+	/* in DCE mode DCDIN is always 0 */
+	if (!(usr2 & USR2_DCDIN))
+		tmp |= TIOCM_CAR;
+
+	if (sport->dte_mode)
+		if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
+			tmp |= TIOCM_RI;
+
+	return tmp;
+}
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void imx_uart_mctrl_check(struct imx_port *sport)
+{
+	unsigned int status, changed;
+
+	status = imx_uart_get_hwmctrl(sport);
+	changed = status ^ sport->old_status;
+
+	if (changed == 0)
+		return;
+
+	sport->old_status = status;
+
+	if (changed & TIOCM_RI && status & TIOCM_RI)
+		sport->port.icount.rng++;
+	if (changed & TIOCM_DSR)
+		sport->port.icount.dsr++;
+	if (changed & TIOCM_CAR)
+		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
+	if (changed & TIOCM_CTS)
+		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
+
+	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
+}
+
+static irqreturn_t imx_uart_int(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
+	irqreturn_t ret = IRQ_NONE;
+
+	spin_lock(&sport->port.lock);
+
+	usr1 = imx_uart_readl(sport, USR1);
+	usr2 = imx_uart_readl(sport, USR2);
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr2 = imx_uart_readl(sport, UCR2);
+	ucr3 = imx_uart_readl(sport, UCR3);
+	ucr4 = imx_uart_readl(sport, UCR4);
+
+	/*
+	 * Even if a condition is true that can trigger an irq only handle it if
+	 * the respective irq source is enabled. This prevents some undesired
+	 * actions, for example if a character that sits in the RX FIFO and that
+	 * should be fetched via DMA is tried to be fetched using PIO. Or the
+	 * receiver is currently off and so reading from URXD0 results in an
+	 * exception. So just mask the (raw) status bits for disabled irqs.
+	 */
+	if ((ucr1 & UCR1_RRDYEN) == 0)
+		usr1 &= ~USR1_RRDY;
+	if ((ucr2 & UCR2_ATEN) == 0)
+		usr1 &= ~USR1_AGTIM;
+	if ((ucr1 & UCR1_TRDYEN) == 0)
+		usr1 &= ~USR1_TRDY;
+	if ((ucr4 & UCR4_TCEN) == 0)
+		usr2 &= ~USR2_TXDC;
+	if ((ucr3 & UCR3_DTRDEN) == 0)
+		usr1 &= ~USR1_DTRD;
+	if ((ucr1 & UCR1_RTSDEN) == 0)
+		usr1 &= ~USR1_RTSD;
+	if ((ucr3 & UCR3_AWAKEN) == 0)
+		usr1 &= ~USR1_AWAKE;
+	if ((ucr4 & UCR4_OREN) == 0)
+		usr2 &= ~USR2_ORE;
+
+	if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
+		imx_uart_writel(sport, USR1_AGTIM, USR1);
+
+		__imx_uart_rxint(irq, dev_id);
+		ret = IRQ_HANDLED;
+	}
+
+	if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
+		imx_uart_transmit_buffer(sport);
+		ret = IRQ_HANDLED;
+	}
+
+	if (usr1 & USR1_DTRD) {
+		imx_uart_writel(sport, USR1_DTRD, USR1);
+
+		imx_uart_mctrl_check(sport);
+
+		ret = IRQ_HANDLED;
+	}
+
+	if (usr1 & USR1_RTSD) {
+		__imx_uart_rtsint(irq, dev_id);
+		ret = IRQ_HANDLED;
+	}
+
+	if (usr1 & USR1_AWAKE) {
+		imx_uart_writel(sport, USR1_AWAKE, USR1);
+		ret = IRQ_HANDLED;
+	}
+
+	if (usr2 & USR2_ORE) {
+		sport->port.icount.overrun++;
+		imx_uart_writel(sport, USR2_ORE, USR2);
+		ret = IRQ_HANDLED;
+	}
+
+	spin_unlock(&sport->port.lock);
+
+	return ret;
+}
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int imx_uart_tx_empty(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned int ret;
+
+	ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
+
+	/* If the TX DMA is working, return 0. */
+	if (sport->dma_is_txing)
+		ret = 0;
+
+	return ret;
+}
+
+/* called with port.lock taken and irqs off */
+static unsigned int imx_uart_get_mctrl(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned int ret = imx_uart_get_hwmctrl(sport);
+
+	mctrl_gpio_get(sport->gpios, &ret);
+
+	return ret;
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	u32 ucr3, uts;
+
+	if (!(port->rs485.flags & SER_RS485_ENABLED)) {
+		u32 ucr2;
+
+		/*
+		 * Turn off autoRTS if RTS is lowered and restore autoRTS
+		 * setting if RTS is raised.
+		 */
+		ucr2 = imx_uart_readl(sport, UCR2);
+		ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
+		if (mctrl & TIOCM_RTS) {
+			ucr2 |= UCR2_CTS;
+			/*
+			 * UCR2_IRTS is unset if and only if the port is
+			 * configured for CRTSCTS, so we use inverted UCR2_IRTS
+			 * to get the state to restore to.
+			 */
+			if (!(ucr2 & UCR2_IRTS))
+				ucr2 |= UCR2_CTSC;
+		}
+		imx_uart_writel(sport, ucr2, UCR2);
+	}
+
+	ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
+	if (!(mctrl & TIOCM_DTR))
+		ucr3 |= UCR3_DSR;
+	imx_uart_writel(sport, ucr3, UCR3);
+
+	uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
+	if (mctrl & TIOCM_LOOP)
+		uts |= UTS_LOOP;
+	imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+
+	mctrl_gpio_set(sport->gpios, mctrl);
+}
+
+/*
+ * Interrupts always disabled.
+ */
+static void imx_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned long flags;
+	u32 ucr1;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
+
+	if (break_state != 0)
+		ucr1 |= UCR1_SNDBRK;
+
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+/*
+ * This is our per-port timeout handler, for checking the
+ * modem status signals.
+ */
+static void imx_uart_timeout(struct timer_list *t)
+{
+	struct imx_port *sport = from_timer(sport, t, timer);
+	unsigned long flags;
+
+	if (sport->port.state) {
+		spin_lock_irqsave(&sport->port.lock, flags);
+		imx_uart_mctrl_check(sport);
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+
+		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
+	}
+}
+
+/*
+ * There are two kinds of RX DMA interrupts(such as in the MX6Q):
+ *   [1] the RX DMA buffer is full.
+ *   [2] the aging timer expires
+ *
+ * Condition [2] is triggered when a character has been sitting in the FIFO
+ * for at least 8 byte durations.
+ */
+static void imx_uart_dma_rx_callback(void *data)
+{
+	struct imx_port *sport = data;
+	struct dma_chan	*chan = sport->dma_chan_rx;
+	struct scatterlist *sgl = &sport->rx_sgl;
+	struct tty_port *port = &sport->port.state->port;
+	struct dma_tx_state state;
+	struct circ_buf *rx_ring = &sport->rx_ring;
+	enum dma_status status;
+	unsigned int w_bytes = 0;
+	unsigned int r_bytes;
+	unsigned int bd_size;
+
+	status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
+
+	if (status == DMA_ERROR) {
+		spin_lock(&sport->port.lock);
+		imx_uart_clear_rx_errors(sport);
+		spin_unlock(&sport->port.lock);
+		return;
+	}
+
+	/*
+	 * The state-residue variable represents the empty space
+	 * relative to the entire buffer. Taking this in consideration
+	 * the head is always calculated base on the buffer total
+	 * length - DMA transaction residue. The UART script from the
+	 * SDMA firmware will jump to the next buffer descriptor,
+	 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
+	 * Taking this in consideration the tail is always at the
+	 * beginning of the buffer descriptor that contains the head.
+	 */
+
+	/* Calculate the head */
+	rx_ring->head = sg_dma_len(sgl) - state.residue;
+
+	/* Calculate the tail. */
+	bd_size = sg_dma_len(sgl) / sport->rx_periods;
+	rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
+
+	if (rx_ring->head <= sg_dma_len(sgl) &&
+	    rx_ring->head > rx_ring->tail) {
+
+		/* Move data from tail to head */
+		r_bytes = rx_ring->head - rx_ring->tail;
+
+		/* If we received something, check for 0xff flood */
+		spin_lock(&sport->port.lock);
+		imx_uart_check_flood(sport, imx_uart_readl(sport, USR2));
+		spin_unlock(&sport->port.lock);
+
+		if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
+
+			/* CPU claims ownership of RX DMA buffer */
+			dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
+					    DMA_FROM_DEVICE);
+
+			w_bytes = tty_insert_flip_string(port,
+							 sport->rx_buf + rx_ring->tail, r_bytes);
+
+			/* UART retrieves ownership of RX DMA buffer */
+			dma_sync_sg_for_device(sport->port.dev, sgl, 1,
+					       DMA_FROM_DEVICE);
+
+			if (w_bytes != r_bytes)
+				sport->port.icount.buf_overrun++;
+
+			sport->port.icount.rx += w_bytes;
+		}
+	} else	{
+		WARN_ON(rx_ring->head > sg_dma_len(sgl));
+		WARN_ON(rx_ring->head <= rx_ring->tail);
+	}
+
+	if (w_bytes) {
+		tty_flip_buffer_push(port);
+		dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
+	}
+}
+
+static int imx_uart_start_rx_dma(struct imx_port *sport)
+{
+	struct scatterlist *sgl = &sport->rx_sgl;
+	struct dma_chan	*chan = sport->dma_chan_rx;
+	struct device *dev = sport->port.dev;
+	struct dma_async_tx_descriptor *desc;
+	int ret;
+
+	sport->rx_ring.head = 0;
+	sport->rx_ring.tail = 0;
+
+	sg_init_one(sgl, sport->rx_buf, sport->rx_buf_size);
+	ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
+	if (ret == 0) {
+		dev_err(dev, "DMA mapping error for RX.\n");
+		return -EINVAL;
+	}
+
+	desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
+		sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
+		DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
+
+	if (!desc) {
+		dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
+		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
+		return -EINVAL;
+	}
+	desc->callback = imx_uart_dma_rx_callback;
+	desc->callback_param = sport;
+
+	dev_dbg(dev, "RX: prepare for the DMA.\n");
+	sport->dma_is_rxing = 1;
+	sport->rx_cookie = dmaengine_submit(desc);
+	dma_async_issue_pending(chan);
+	return 0;
+}
+
+static void imx_uart_clear_rx_errors(struct imx_port *sport)
+{
+	struct tty_port *port = &sport->port.state->port;
+	u32 usr1, usr2;
+
+	usr1 = imx_uart_readl(sport, USR1);
+	usr2 = imx_uart_readl(sport, USR2);
+
+	if (usr2 & USR2_BRCD) {
+		sport->port.icount.brk++;
+		imx_uart_writel(sport, USR2_BRCD, USR2);
+		uart_handle_break(&sport->port);
+		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
+			sport->port.icount.buf_overrun++;
+		tty_flip_buffer_push(port);
+	} else {
+		if (usr1 & USR1_FRAMERR) {
+			sport->port.icount.frame++;
+			imx_uart_writel(sport, USR1_FRAMERR, USR1);
+		} else if (usr1 & USR1_PARITYERR) {
+			sport->port.icount.parity++;
+			imx_uart_writel(sport, USR1_PARITYERR, USR1);
+		}
+	}
+
+	if (usr2 & USR2_ORE) {
+		sport->port.icount.overrun++;
+		imx_uart_writel(sport, USR2_ORE, USR2);
+	}
+
+	sport->idle_counter = 0;
+
+}
+
+#define TXTL_DEFAULT 2 /* reset default */
+#define RXTL_DEFAULT 8 /* 8 characters or aging timer */
+#define TXTL_DMA 8 /* DMA burst setting */
+#define RXTL_DMA 9 /* DMA burst setting */
+
+static void imx_uart_setup_ufcr(struct imx_port *sport,
+				unsigned char txwl, unsigned char rxwl)
+{
+	unsigned int val;
+
+	/* set receiver / transmitter trigger level */
+	val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
+	val |= txwl << UFCR_TXTL_SHF | rxwl;
+	imx_uart_writel(sport, val, UFCR);
+}
+
+static void imx_uart_dma_exit(struct imx_port *sport)
+{
+	if (sport->dma_chan_rx) {
+		dmaengine_terminate_sync(sport->dma_chan_rx);
+		dma_release_channel(sport->dma_chan_rx);
+		sport->dma_chan_rx = NULL;
+		sport->rx_cookie = -EINVAL;
+		kfree(sport->rx_buf);
+		sport->rx_buf = NULL;
+	}
+
+	if (sport->dma_chan_tx) {
+		dmaengine_terminate_sync(sport->dma_chan_tx);
+		dma_release_channel(sport->dma_chan_tx);
+		sport->dma_chan_tx = NULL;
+	}
+}
+
+static int imx_uart_dma_init(struct imx_port *sport)
+{
+	struct dma_slave_config slave_config = {};
+	struct device *dev = sport->port.dev;
+	int ret;
+
+	/* Prepare for RX : */
+	sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
+	if (!sport->dma_chan_rx) {
+		dev_dbg(dev, "cannot get the DMA channel.\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	slave_config.direction = DMA_DEV_TO_MEM;
+	slave_config.src_addr = sport->port.mapbase + URXD0;
+	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	/* one byte less than the watermark level to enable the aging timer */
+	slave_config.src_maxburst = RXTL_DMA - 1;
+	ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
+	if (ret) {
+		dev_err(dev, "error in RX dma configuration.\n");
+		goto err;
+	}
+
+	sport->rx_buf_size = sport->rx_period_length * sport->rx_periods;
+	sport->rx_buf = kzalloc(sport->rx_buf_size, GFP_KERNEL);
+	if (!sport->rx_buf) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	sport->rx_ring.buf = sport->rx_buf;
+
+	/* Prepare for TX : */
+	sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
+	if (!sport->dma_chan_tx) {
+		dev_err(dev, "cannot get the TX DMA channel!\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	slave_config.direction = DMA_MEM_TO_DEV;
+	slave_config.dst_addr = sport->port.mapbase + URTX0;
+	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	slave_config.dst_maxburst = TXTL_DMA;
+	ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
+	if (ret) {
+		dev_err(dev, "error in TX dma configuration.");
+		goto err;
+	}
+
+	return 0;
+err:
+	imx_uart_dma_exit(sport);
+	return ret;
+}
+
+static void imx_uart_enable_dma(struct imx_port *sport)
+{
+	u32 ucr1;
+
+	imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
+
+	/* set UCR1 */
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	sport->dma_is_enabled = 1;
+}
+
+static void imx_uart_disable_dma(struct imx_port *sport)
+{
+	u32 ucr1;
+
+	/* clear UCR1 */
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+	sport->dma_is_enabled = 0;
+}
+
+/* half the RX buffer size */
+#define CTSTL 16
+
+static int imx_uart_startup(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	int retval;
+	unsigned long flags;
+	int dma_is_inited = 0;
+	u32 ucr1, ucr2, ucr3, ucr4;
+
+	retval = clk_prepare_enable(sport->clk_per);
+	if (retval)
+		return retval;
+	retval = clk_prepare_enable(sport->clk_ipg);
+	if (retval) {
+		clk_disable_unprepare(sport->clk_per);
+		return retval;
+	}
+
+	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+	/* disable the DREN bit (Data Ready interrupt enable) before
+	 * requesting IRQs
+	 */
+	ucr4 = imx_uart_readl(sport, UCR4);
+
+	/* set the trigger level for CTS */
+	ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
+	ucr4 |= CTSTL << UCR4_CTSTL_SHF;
+
+	imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
+
+	/* Can we enable the DMA support? */
+	if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
+		dma_is_inited = 1;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	/* Reset fifo's and state machines */
+	imx_uart_soft_reset(sport);
+
+	/*
+	 * Finally, clear and enable interrupts
+	 */
+	imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
+	imx_uart_writel(sport, USR2_ORE, USR2);
+
+	ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
+	ucr1 |= UCR1_UARTEN;
+	if (sport->have_rtscts)
+		ucr1 |= UCR1_RTSDEN;
+
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR);
+	if (!dma_is_inited)
+		ucr4 |= UCR4_OREN;
+	if (sport->inverted_rx)
+		ucr4 |= UCR4_INVR;
+	imx_uart_writel(sport, ucr4, UCR4);
+
+	ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT;
+	/*
+	 * configure tx polarity before enabling tx
+	 */
+	if (sport->inverted_tx)
+		ucr3 |= UCR3_INVT;
+
+	if (!imx_uart_is_imx1(sport)) {
+		ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
+
+		if (sport->dte_mode)
+			/* disable broken interrupts */
+			ucr3 &= ~(UCR3_RI | UCR3_DCD);
+	}
+	imx_uart_writel(sport, ucr3, UCR3);
+
+	ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
+	ucr2 |= (UCR2_RXEN | UCR2_TXEN);
+	if (!sport->have_rtscts)
+		ucr2 |= UCR2_IRTS;
+	/*
+	 * make sure the edge sensitive RTS-irq is disabled,
+	 * we're using RTSD instead.
+	 */
+	if (!imx_uart_is_imx1(sport))
+		ucr2 &= ~UCR2_RTSEN;
+	imx_uart_writel(sport, ucr2, UCR2);
+
+	/*
+	 * Enable modem status interrupts
+	 */
+	imx_uart_enable_ms(&sport->port);
+
+	if (dma_is_inited) {
+		imx_uart_enable_dma(sport);
+		imx_uart_start_rx_dma(sport);
+	} else {
+		ucr1 = imx_uart_readl(sport, UCR1);
+		ucr1 |= UCR1_RRDYEN;
+		imx_uart_writel(sport, ucr1, UCR1);
+
+		ucr2 = imx_uart_readl(sport, UCR2);
+		ucr2 |= UCR2_ATEN;
+		imx_uart_writel(sport, ucr2, UCR2);
+	}
+
+	imx_uart_disable_loopback_rs485(sport);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	return 0;
+}
+
+static void imx_uart_shutdown(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned long flags;
+	u32 ucr1, ucr2, ucr4, uts;
+
+	if (sport->dma_is_enabled) {
+		dmaengine_terminate_sync(sport->dma_chan_tx);
+		if (sport->dma_is_txing) {
+			dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
+				     sport->dma_tx_nents, DMA_TO_DEVICE);
+			sport->dma_is_txing = 0;
+		}
+		dmaengine_terminate_sync(sport->dma_chan_rx);
+		if (sport->dma_is_rxing) {
+			dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
+				     1, DMA_FROM_DEVICE);
+			sport->dma_is_rxing = 0;
+		}
+
+		spin_lock_irqsave(&sport->port.lock, flags);
+		imx_uart_stop_tx(port);
+		imx_uart_stop_rx(port);
+		imx_uart_disable_dma(sport);
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+		imx_uart_dma_exit(sport);
+	}
+
+	mctrl_gpio_disable_ms(sport->gpios);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	ucr2 = imx_uart_readl(sport, UCR2);
+	ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
+	imx_uart_writel(sport, ucr2, UCR2);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	/*
+	 * Stop our timer.
+	 */
+	del_timer_sync(&sport->timer);
+
+	/*
+	 * Disable all interrupts, port and break condition.
+	 */
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_RXDMAEN |
+		  UCR1_ATDMAEN | UCR1_SNDBRK);
+	/* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
+	if (port->rs485.flags & SER_RS485_ENABLED &&
+	    port->rs485.flags & SER_RS485_RTS_ON_SEND &&
+	    sport->have_rtscts && !sport->have_rtsgpio) {
+		uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
+		uts |= UTS_LOOP;
+		imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+		ucr1 |= UCR1_UARTEN;
+	} else {
+		ucr1 &= ~UCR1_UARTEN;
+	}
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	ucr4 = imx_uart_readl(sport, UCR4);
+	ucr4 &= ~UCR4_TCEN;
+	imx_uart_writel(sport, ucr4, UCR4);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	clk_disable_unprepare(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_flush_buffer(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	struct scatterlist *sgl = &sport->tx_sgl[0];
+
+	if (!sport->dma_chan_tx)
+		return;
+
+	sport->tx_bytes = 0;
+	dmaengine_terminate_all(sport->dma_chan_tx);
+	if (sport->dma_is_txing) {
+		u32 ucr1;
+
+		dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
+			     DMA_TO_DEVICE);
+		ucr1 = imx_uart_readl(sport, UCR1);
+		ucr1 &= ~UCR1_TXDMAEN;
+		imx_uart_writel(sport, ucr1, UCR1);
+		sport->dma_is_txing = 0;
+	}
+
+	imx_uart_soft_reset(sport);
+
+}
+
+static void
+imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
+		     const struct ktermios *old)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned long flags;
+	u32 ucr2, old_ucr2, ufcr;
+	unsigned int baud, quot;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+	unsigned long div;
+	unsigned long num, denom, old_ubir, old_ubmr;
+	uint64_t tdiv64;
+
+	/*
+	 * We only support CS7 and CS8.
+	 */
+	while ((termios->c_cflag & CSIZE) != CS7 &&
+	       (termios->c_cflag & CSIZE) != CS8) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	del_timer_sync(&sport->timer);
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
+	quot = uart_get_divisor(port, baud);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	/*
+	 * Read current UCR2 and save it for future use, then clear all the bits
+	 * except those we will or may need to preserve.
+	 */
+	old_ucr2 = imx_uart_readl(sport, UCR2);
+	ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
+
+	ucr2 |= UCR2_SRST | UCR2_IRTS;
+	if ((termios->c_cflag & CSIZE) == CS8)
+		ucr2 |= UCR2_WS;
+
+	if (!sport->have_rtscts)
+		termios->c_cflag &= ~CRTSCTS;
+
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		/*
+		 * RTS is mandatory for rs485 operation, so keep
+		 * it under manual control and keep transmitter
+		 * disabled.
+		 */
+		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+			imx_uart_rts_active(sport, &ucr2);
+		else
+			imx_uart_rts_inactive(sport, &ucr2);
+
+	} else if (termios->c_cflag & CRTSCTS) {
+		/*
+		 * Only let receiver control RTS output if we were not requested
+		 * to have RTS inactive (which then should take precedence).
+		 */
+		if (ucr2 & UCR2_CTS)
+			ucr2 |= UCR2_CTSC;
+	}
+
+	if (termios->c_cflag & CRTSCTS)
+		ucr2 &= ~UCR2_IRTS;
+	if (termios->c_cflag & CSTOPB)
+		ucr2 |= UCR2_STPB;
+	if (termios->c_cflag & PARENB) {
+		ucr2 |= UCR2_PREN;
+		if (termios->c_cflag & PARODD)
+			ucr2 |= UCR2_PROE;
+	}
+
+	sport->port.read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		sport->port.read_status_mask |= URXD_BRK;
+
+	/*
+	 * Characters to ignore
+	 */
+	sport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
+	if (termios->c_iflag & IGNBRK) {
+		sport->port.ignore_status_mask |= URXD_BRK;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			sport->port.ignore_status_mask |= URXD_OVRRUN;
+	}
+
+	if ((termios->c_cflag & CREAD) == 0)
+		sport->port.ignore_status_mask |= URXD_DUMMY_READ;
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* custom-baudrate handling */
+	div = sport->port.uartclk / (baud * 16);
+	if (baud == 38400 && quot != div)
+		baud = sport->port.uartclk / (quot * 16);
+
+	div = sport->port.uartclk / (baud * 16);
+	if (div > 7)
+		div = 7;
+	if (!div)
+		div = 1;
+
+	rational_best_approximation(16 * div * baud, sport->port.uartclk,
+		1 << 16, 1 << 16, &num, &denom);
+
+	tdiv64 = sport->port.uartclk;
+	tdiv64 *= num;
+	do_div(tdiv64, denom * 16 * div);
+	tty_termios_encode_baud_rate(termios,
+				(speed_t)tdiv64, (speed_t)tdiv64);
+
+	num -= 1;
+	denom -= 1;
+
+	ufcr = imx_uart_readl(sport, UFCR);
+	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
+	imx_uart_writel(sport, ufcr, UFCR);
+
+	/*
+	 *  Two registers below should always be written both and in this
+	 *  particular order. One consequence is that we need to check if any of
+	 *  them changes and then update both. We do need the check for change
+	 *  as even writing the same values seem to "restart"
+	 *  transmission/receiving logic in the hardware, that leads to data
+	 *  breakage even when rate doesn't in fact change. E.g., user switches
+	 *  RTS/CTS handshake and suddenly gets broken bytes.
+	 */
+	old_ubir = imx_uart_readl(sport, UBIR);
+	old_ubmr = imx_uart_readl(sport, UBMR);
+	if (old_ubir != num || old_ubmr != denom) {
+		imx_uart_writel(sport, num, UBIR);
+		imx_uart_writel(sport, denom, UBMR);
+	}
+
+	if (!imx_uart_is_imx1(sport))
+		imx_uart_writel(sport, sport->port.uartclk / div / 1000,
+				IMX21_ONEMS);
+
+	imx_uart_writel(sport, ucr2, UCR2);
+
+	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
+		imx_uart_enable_ms(&sport->port);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static const char *imx_uart_type(struct uart_port *port)
+{
+	return port->type == PORT_IMX ? "IMX" : NULL;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void imx_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_IMX;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ * The only change we allow are to the flags and type, and
+ * even then only between PORT_IMX and PORT_UNKNOWN
+ */
+static int
+imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
+		ret = -EINVAL;
+	if (port->irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->io_type != UPIO_MEM)
+		ret = -EINVAL;
+	if (port->uartclk / 16 != ser->baud_base)
+		ret = -EINVAL;
+	if (port->mapbase != (unsigned long)ser->iomem_base)
+		ret = -EINVAL;
+	if (port->iobase != ser->port)
+		ret = -EINVAL;
+	if (ser->hub6 != 0)
+		ret = -EINVAL;
+	return ret;
+}
+
+#if defined(CONFIG_CONSOLE_POLL)
+
+static int imx_uart_poll_init(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned long flags;
+	u32 ucr1, ucr2;
+	int retval;
+
+	retval = clk_prepare_enable(sport->clk_ipg);
+	if (retval)
+		return retval;
+	retval = clk_prepare_enable(sport->clk_per);
+	if (retval)
+		clk_disable_unprepare(sport->clk_ipg);
+
+	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	/*
+	 * Be careful about the order of enabling bits here. First enable the
+	 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
+	 * This prevents that a character that already sits in the RX fifo is
+	 * triggering an irq but the try to fetch it from there results in an
+	 * exception because UARTEN or RXEN is still off.
+	 */
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr2 = imx_uart_readl(sport, UCR2);
+
+	if (imx_uart_is_imx1(sport))
+		ucr1 |= IMX1_UCR1_UARTCLKEN;
+
+	ucr1 |= UCR1_UARTEN;
+	ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
+
+	ucr2 |= UCR2_RXEN | UCR2_TXEN;
+	ucr2 &= ~UCR2_ATEN;
+
+	imx_uart_writel(sport, ucr1, UCR1);
+	imx_uart_writel(sport, ucr2, UCR2);
+
+	/* now enable irqs */
+	imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
+	imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	return 0;
+}
+
+static int imx_uart_poll_get_char(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
+		return NO_POLL_CHAR;
+
+	return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
+}
+
+static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned int status;
+
+	/* drain */
+	do {
+		status = imx_uart_readl(sport, USR1);
+	} while (~status & USR1_TRDY);
+
+	/* write */
+	imx_uart_writel(sport, c, URTX0);
+
+	/* flush */
+	do {
+		status = imx_uart_readl(sport, USR2);
+	} while (~status & USR2_TXDC);
+}
+#endif
+
+/* called with port.lock taken and irqs off or from .probe without locking */
+static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termios,
+				 struct serial_rs485 *rs485conf)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	u32 ucr2;
+
+	if (rs485conf->flags & SER_RS485_ENABLED) {
+		/* Enable receiver if low-active RTS signal is requested */
+		if (sport->have_rtscts &&  !sport->have_rtsgpio &&
+		    !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
+			rs485conf->flags |= SER_RS485_RX_DURING_TX;
+
+		/* disable transmitter */
+		ucr2 = imx_uart_readl(sport, UCR2);
+		if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
+			imx_uart_rts_active(sport, &ucr2);
+		else
+			imx_uart_rts_inactive(sport, &ucr2);
+		imx_uart_writel(sport, ucr2, UCR2);
+	}
+
+	/* Make sure Rx is enabled in case Tx is active with Rx disabled */
+	if (!(rs485conf->flags & SER_RS485_ENABLED) ||
+	    rs485conf->flags & SER_RS485_RX_DURING_TX)
+		imx_uart_start_rx(port);
+
+	return 0;
+}
+
+static const struct uart_ops imx_uart_pops = {
+	.tx_empty	= imx_uart_tx_empty,
+	.set_mctrl	= imx_uart_set_mctrl,
+	.get_mctrl	= imx_uart_get_mctrl,
+	.stop_tx	= imx_uart_stop_tx,
+	.start_tx	= imx_uart_start_tx,
+	.stop_rx	= imx_uart_stop_rx,
+	.enable_ms	= imx_uart_enable_ms,
+	.break_ctl	= imx_uart_break_ctl,
+	.startup	= imx_uart_startup,
+	.shutdown	= imx_uart_shutdown,
+	.flush_buffer	= imx_uart_flush_buffer,
+	.set_termios	= imx_uart_set_termios,
+	.type		= imx_uart_type,
+	.config_port	= imx_uart_config_port,
+	.verify_port	= imx_uart_verify_port,
+#if defined(CONFIG_CONSOLE_POLL)
+	.poll_init      = imx_uart_poll_init,
+	.poll_get_char  = imx_uart_poll_get_char,
+	.poll_put_char  = imx_uart_poll_put_char,
+#endif
+};
+
+static struct imx_port *imx_uart_ports[UART_NR];
+
+#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
+static void imx_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
+		barrier();
+
+	imx_uart_writel(sport, ch, URTX0);
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+imx_uart_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct imx_port *sport = imx_uart_ports[co->index];
+	struct imx_port_ucrs old_ucr;
+	unsigned long flags;
+	unsigned int ucr1;
+	int locked = 1;
+
+	if (sport->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&sport->port.lock, flags);
+	else
+		spin_lock_irqsave(&sport->port.lock, flags);
+
+	/*
+	 *	First, save UCR1/2/3 and then disable interrupts
+	 */
+	imx_uart_ucrs_save(sport, &old_ucr);
+	ucr1 = old_ucr.ucr1;
+
+	if (imx_uart_is_imx1(sport))
+		ucr1 |= IMX1_UCR1_UARTCLKEN;
+	ucr1 |= UCR1_UARTEN;
+	ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
+
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
+
+	uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore UCR1/2/3
+	 */
+	while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
+
+	imx_uart_ucrs_restore(sport, &old_ucr);
+
+	if (locked)
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void
+imx_uart_console_get_options(struct imx_port *sport, int *baud,
+			     int *parity, int *bits)
+{
+
+	if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
+		/* ok, the port was enabled */
+		unsigned int ucr2, ubir, ubmr, uartclk;
+		unsigned int baud_raw;
+		unsigned int ucfr_rfdiv;
+
+		ucr2 = imx_uart_readl(sport, UCR2);
+
+		*parity = 'n';
+		if (ucr2 & UCR2_PREN) {
+			if (ucr2 & UCR2_PROE)
+				*parity = 'o';
+			else
+				*parity = 'e';
+		}
+
+		if (ucr2 & UCR2_WS)
+			*bits = 8;
+		else
+			*bits = 7;
+
+		ubir = imx_uart_readl(sport, UBIR) & 0xffff;
+		ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
+
+		ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
+		if (ucfr_rfdiv == 6)
+			ucfr_rfdiv = 7;
+		else
+			ucfr_rfdiv = 6 - ucfr_rfdiv;
+
+		uartclk = clk_get_rate(sport->clk_per);
+		uartclk /= ucfr_rfdiv;
+
+		{	/*
+			 * The next code provides exact computation of
+			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
+			 * without need of float support or long long division,
+			 * which would be required to prevent 32bit arithmetic overflow
+			 */
+			unsigned int mul = ubir + 1;
+			unsigned int div = 16 * (ubmr + 1);
+			unsigned int rem = uartclk % div;
+
+			baud_raw = (uartclk / div) * mul;
+			baud_raw += (rem * mul + div / 2) / div;
+			*baud = (baud_raw + 50) / 100 * 100;
+		}
+
+		if (*baud != baud_raw)
+			dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
+				baud_raw, *baud);
+	}
+}
+
+static int
+imx_uart_console_setup(struct console *co, char *options)
+{
+	struct imx_port *sport;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int retval;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
+		co->index = 0;
+	sport = imx_uart_ports[co->index];
+	if (sport == NULL)
+		return -ENODEV;
+
+	/* For setting the registers, we only need to enable the ipg clock. */
+	retval = clk_prepare_enable(sport->clk_ipg);
+	if (retval)
+		goto error_console;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		imx_uart_console_get_options(sport, &baud, &parity, &bits);
+
+	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
+
+	if (retval) {
+		clk_disable_unprepare(sport->clk_ipg);
+		goto error_console;
+	}
+
+	retval = clk_prepare_enable(sport->clk_per);
+	if (retval)
+		clk_disable_unprepare(sport->clk_ipg);
+
+error_console:
+	return retval;
+}
+
+static int
+imx_uart_console_exit(struct console *co)
+{
+	struct imx_port *sport = imx_uart_ports[co->index];
+
+	clk_disable_unprepare(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
+
+	return 0;
+}
+
+static struct uart_driver imx_uart_uart_driver;
+static struct console imx_uart_console = {
+	.name		= DEV_NAME,
+	.write		= imx_uart_console_write,
+	.device		= uart_console_device,
+	.setup		= imx_uart_console_setup,
+	.exit		= imx_uart_console_exit,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &imx_uart_uart_driver,
+};
+
+#define IMX_CONSOLE	&imx_uart_console
+
+#else
+#define IMX_CONSOLE	NULL
+#endif
+
+static struct uart_driver imx_uart_uart_driver = {
+	.owner          = THIS_MODULE,
+	.driver_name    = DRIVER_NAME,
+	.dev_name       = DEV_NAME,
+	.major          = SERIAL_IMX_MAJOR,
+	.minor          = MINOR_START,
+	.nr             = ARRAY_SIZE(imx_uart_ports),
+	.cons           = IMX_CONSOLE,
+};
+
+static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t)
+{
+	struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	if (sport->tx_state == WAIT_AFTER_RTS)
+		imx_uart_start_tx(&sport->port);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	return HRTIMER_NORESTART;
+}
+
+static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
+{
+	struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	if (sport->tx_state == WAIT_AFTER_SEND)
+		imx_uart_stop_tx(&sport->port);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	return HRTIMER_NORESTART;
+}
+
+static const struct serial_rs485 imx_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+		 SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+/* Default RX DMA buffer configuration */
+#define RX_DMA_PERIODS		16
+#define RX_DMA_PERIOD_LEN	(PAGE_SIZE / 4)
+
+static int imx_uart_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct imx_port *sport;
+	void __iomem *base;
+	u32 dma_buf_conf[2];
+	int ret = 0;
+	u32 ucr1, ucr2, uts;
+	struct resource *res;
+	int txirq, rxirq, rtsirq;
+
+	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	sport->devdata = of_device_get_match_data(&pdev->dev);
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+		return ret;
+	}
+	sport->port.line = ret;
+
+	sport->have_rtscts = of_property_read_bool(np, "uart-has-rtscts") ||
+		of_property_read_bool(np, "fsl,uart-has-rtscts"); /* deprecated */
+
+	sport->dte_mode = of_property_read_bool(np, "fsl,dte-mode");
+
+	sport->have_rtsgpio = of_property_present(np, "rts-gpios");
+
+	sport->inverted_tx = of_property_read_bool(np, "fsl,inverted-tx");
+
+	sport->inverted_rx = of_property_read_bool(np, "fsl,inverted-rx");
+
+	if (!of_property_read_u32_array(np, "fsl,dma-info", dma_buf_conf, 2)) {
+		sport->rx_period_length = dma_buf_conf[0];
+		sport->rx_periods = dma_buf_conf[1];
+	} else {
+		sport->rx_period_length = RX_DMA_PERIOD_LEN;
+		sport->rx_periods = RX_DMA_PERIODS;
+	}
+
+	if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n",
+			sport->port.line);
+		return -EINVAL;
+	}
+
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	rxirq = platform_get_irq(pdev, 0);
+	if (rxirq < 0)
+		return rxirq;
+	txirq = platform_get_irq_optional(pdev, 1);
+	rtsirq = platform_get_irq_optional(pdev, 2);
+
+	sport->port.dev = &pdev->dev;
+	sport->port.mapbase = res->start;
+	sport->port.membase = base;
+	sport->port.type = PORT_IMX;
+	sport->port.iotype = UPIO_MEM;
+	sport->port.irq = rxirq;
+	sport->port.fifosize = 32;
+	sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE);
+	sport->port.ops = &imx_uart_pops;
+	sport->port.rs485_config = imx_uart_rs485_config;
+	/* RTS is required to control the RS485 transmitter */
+	if (sport->have_rtscts || sport->have_rtsgpio)
+		sport->port.rs485_supported = imx_rs485_supported;
+	sport->port.flags = UPF_BOOT_AUTOCONF;
+	timer_setup(&sport->timer, imx_uart_timeout, 0);
+
+	sport->gpios = mctrl_gpio_init(&sport->port, 0);
+	if (IS_ERR(sport->gpios))
+		return PTR_ERR(sport->gpios);
+
+	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(sport->clk_ipg)) {
+		ret = PTR_ERR(sport->clk_ipg);
+		dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
+		return ret;
+	}
+
+	sport->clk_per = devm_clk_get(&pdev->dev, "per");
+	if (IS_ERR(sport->clk_per)) {
+		ret = PTR_ERR(sport->clk_per);
+		dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
+		return ret;
+	}
+
+	sport->port.uartclk = clk_get_rate(sport->clk_per);
+
+	/* For register access, we only need to enable the ipg clock. */
+	ret = clk_prepare_enable(sport->clk_ipg);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
+		return ret;
+	}
+
+	ret = uart_get_rs485_mode(&sport->port);
+	if (ret)
+		goto err_clk;
+
+	/*
+	 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
+	 * signal cannot be set low during transmission in case the
+	 * receiver is off (limitation of the i.MX UART IP).
+	 */
+	if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+	    sport->have_rtscts && !sport->have_rtsgpio &&
+	    (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
+	     !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
+		dev_err(&pdev->dev,
+			"low-active RTS not possible when receiver is off, enabling receiver\n");
+
+	/* Disable interrupts before requesting them */
+	ucr1 = imx_uart_readl(sport, UCR1);
+	ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN);
+	imx_uart_writel(sport, ucr1, UCR1);
+
+	/* Disable Ageing Timer interrupt */
+	ucr2 = imx_uart_readl(sport, UCR2);
+	ucr2 &= ~UCR2_ATEN;
+	imx_uart_writel(sport, ucr2, UCR2);
+
+	/*
+	 * In case RS485 is enabled without GPIO RTS control, the UART IP
+	 * is used to control CTS signal. Keep both the UART and Receiver
+	 * enabled, otherwise the UART IP pulls CTS signal always HIGH no
+	 * matter how the UCR2 CTSC and CTS bits are set. To prevent any
+	 * data from being fed into the RX FIFO, enable loopback mode in
+	 * UTS register, which disconnects the RX path from external RXD
+	 * pin and connects it to the Transceiver, which is disabled, so
+	 * no data can be fed to the RX FIFO that way.
+	 */
+	if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+	    sport->have_rtscts && !sport->have_rtsgpio) {
+		uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
+		uts |= UTS_LOOP;
+		imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+
+		ucr1 = imx_uart_readl(sport, UCR1);
+		ucr1 |= UCR1_UARTEN;
+		imx_uart_writel(sport, ucr1, UCR1);
+
+		ucr2 = imx_uart_readl(sport, UCR2);
+		ucr2 |= UCR2_RXEN;
+		imx_uart_writel(sport, ucr2, UCR2);
+	}
+
+	if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
+		/*
+		 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
+		 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
+		 * and DCD (when they are outputs) or enables the respective
+		 * irqs. So set this bit early, i.e. before requesting irqs.
+		 */
+		u32 ufcr = imx_uart_readl(sport, UFCR);
+		if (!(ufcr & UFCR_DCEDTE))
+			imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
+
+		/*
+		 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
+		 * enabled later because they cannot be cleared
+		 * (confirmed on i.MX25) which makes them unusable.
+		 */
+		imx_uart_writel(sport,
+				IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
+				UCR3);
+
+	} else {
+		u32 ucr3 = UCR3_DSR;
+		u32 ufcr = imx_uart_readl(sport, UFCR);
+		if (ufcr & UFCR_DCEDTE)
+			imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
+
+		if (!imx_uart_is_imx1(sport))
+			ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
+		imx_uart_writel(sport, ucr3, UCR3);
+	}
+
+	hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	sport->trigger_start_tx.function = imx_trigger_start_tx;
+	sport->trigger_stop_tx.function = imx_trigger_stop_tx;
+
+	/*
+	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
+	 * chips only have one interrupt.
+	 */
+	if (txirq > 0) {
+		ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
+				       dev_name(&pdev->dev), sport);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request rx irq: %d\n",
+				ret);
+			goto err_clk;
+		}
+
+		ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
+				       dev_name(&pdev->dev), sport);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request tx irq: %d\n",
+				ret);
+			goto err_clk;
+		}
+
+		ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
+				       dev_name(&pdev->dev), sport);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request rts irq: %d\n",
+				ret);
+			goto err_clk;
+		}
+	} else {
+		ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
+				       dev_name(&pdev->dev), sport);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
+			goto err_clk;
+		}
+	}
+
+	imx_uart_ports[sport->port.line] = sport;
+
+	platform_set_drvdata(pdev, sport);
+
+	ret = uart_add_one_port(&imx_uart_uart_driver, &sport->port);
+
+err_clk:
+	clk_disable_unprepare(sport->clk_ipg);
+
+	return ret;
+}
+
+static int imx_uart_remove(struct platform_device *pdev)
+{
+	struct imx_port *sport = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
+
+	return 0;
+}
+
+static void imx_uart_restore_context(struct imx_port *sport)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	if (!sport->context_saved) {
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+		return;
+	}
+
+	imx_uart_writel(sport, sport->saved_reg[4], UFCR);
+	imx_uart_writel(sport, sport->saved_reg[5], UESC);
+	imx_uart_writel(sport, sport->saved_reg[6], UTIM);
+	imx_uart_writel(sport, sport->saved_reg[7], UBIR);
+	imx_uart_writel(sport, sport->saved_reg[8], UBMR);
+	imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
+	imx_uart_writel(sport, sport->saved_reg[0], UCR1);
+	imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
+	imx_uart_writel(sport, sport->saved_reg[2], UCR3);
+	imx_uart_writel(sport, sport->saved_reg[3], UCR4);
+	sport->context_saved = false;
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static void imx_uart_save_context(struct imx_port *sport)
+{
+	unsigned long flags;
+
+	/* Save necessary regs */
+	spin_lock_irqsave(&sport->port.lock, flags);
+	sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
+	sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
+	sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
+	sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
+	sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
+	sport->saved_reg[5] = imx_uart_readl(sport, UESC);
+	sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
+	sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
+	sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
+	sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
+	sport->context_saved = true;
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
+{
+	u32 ucr3;
+
+	ucr3 = imx_uart_readl(sport, UCR3);
+	if (on) {
+		imx_uart_writel(sport, USR1_AWAKE, USR1);
+		ucr3 |= UCR3_AWAKEN;
+	} else {
+		ucr3 &= ~UCR3_AWAKEN;
+	}
+	imx_uart_writel(sport, ucr3, UCR3);
+
+	if (sport->have_rtscts) {
+		u32 ucr1 = imx_uart_readl(sport, UCR1);
+		if (on) {
+			imx_uart_writel(sport, USR1_RTSD, USR1);
+			ucr1 |= UCR1_RTSDEN;
+		} else {
+			ucr1 &= ~UCR1_RTSDEN;
+		}
+		imx_uart_writel(sport, ucr1, UCR1);
+	}
+}
+
+static int imx_uart_suspend_noirq(struct device *dev)
+{
+	struct imx_port *sport = dev_get_drvdata(dev);
+
+	imx_uart_save_context(sport);
+
+	clk_disable(sport->clk_ipg);
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int imx_uart_resume_noirq(struct device *dev)
+{
+	struct imx_port *sport = dev_get_drvdata(dev);
+	int ret;
+
+	pinctrl_pm_select_default_state(dev);
+
+	ret = clk_enable(sport->clk_ipg);
+	if (ret)
+		return ret;
+
+	imx_uart_restore_context(sport);
+
+	return 0;
+}
+
+static int imx_uart_suspend(struct device *dev)
+{
+	struct imx_port *sport = dev_get_drvdata(dev);
+	int ret;
+
+	uart_suspend_port(&imx_uart_uart_driver, &sport->port);
+	disable_irq(sport->port.irq);
+
+	ret = clk_prepare_enable(sport->clk_ipg);
+	if (ret)
+		return ret;
+
+	/* enable wakeup from i.MX UART */
+	imx_uart_enable_wakeup(sport, true);
+
+	return 0;
+}
+
+static int imx_uart_resume(struct device *dev)
+{
+	struct imx_port *sport = dev_get_drvdata(dev);
+
+	/* disable wakeup from i.MX UART */
+	imx_uart_enable_wakeup(sport, false);
+
+	uart_resume_port(&imx_uart_uart_driver, &sport->port);
+	enable_irq(sport->port.irq);
+
+	clk_disable_unprepare(sport->clk_ipg);
+
+	return 0;
+}
+
+static int imx_uart_freeze(struct device *dev)
+{
+	struct imx_port *sport = dev_get_drvdata(dev);
+
+	uart_suspend_port(&imx_uart_uart_driver, &sport->port);
+
+	return clk_prepare_enable(sport->clk_ipg);
+}
+
+static int imx_uart_thaw(struct device *dev)
+{
+	struct imx_port *sport = dev_get_drvdata(dev);
+
+	uart_resume_port(&imx_uart_uart_driver, &sport->port);
+
+	clk_disable_unprepare(sport->clk_ipg);
+
+	return 0;
+}
+
+static const struct dev_pm_ops imx_uart_pm_ops = {
+	.suspend_noirq = imx_uart_suspend_noirq,
+	.resume_noirq = imx_uart_resume_noirq,
+	.freeze_noirq = imx_uart_suspend_noirq,
+	.thaw_noirq = imx_uart_resume_noirq,
+	.restore_noirq = imx_uart_resume_noirq,
+	.suspend = imx_uart_suspend,
+	.resume = imx_uart_resume,
+	.freeze = imx_uart_freeze,
+	.thaw = imx_uart_thaw,
+	.restore = imx_uart_thaw,
+};
+
+static struct platform_driver imx_uart_platform_driver = {
+	.probe = imx_uart_probe,
+	.remove = imx_uart_remove,
+
+	.driver = {
+		.name = "imx-uart",
+		.of_match_table = imx_uart_dt_ids,
+		.pm = &imx_uart_pm_ops,
+	},
+};
+
+static int __init imx_uart_init(void)
+{
+	int ret = uart_register_driver(&imx_uart_uart_driver);
+
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&imx_uart_platform_driver);
+	if (ret != 0)
+		uart_unregister_driver(&imx_uart_uart_driver);
+
+	return ret;
+}
+
+static void __exit imx_uart_exit(void)
+{
+	platform_driver_unregister(&imx_uart_platform_driver);
+	uart_unregister_driver(&imx_uart_uart_driver);
+}
+
+module_init(imx_uart_init);
+module_exit(imx_uart_exit);
+
+MODULE_AUTHOR("Sascha Hauer");
+MODULE_DESCRIPTION("IMX generic serial port driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:imx-uart");
diff --git a/drivers/tty/serial/imx_earlycon.c b/drivers/tty/serial/imx_earlycon.c
new file mode 100644
index 000000000..7aab38b2b
--- /dev/null
+++ b/drivers/tty/serial/imx_earlycon.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2020 NXP
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/io.h>
+
+#define URTX0 0x40 /* Transmitter Register */
+#define UTS_TXFULL (1<<4) /* TxFIFO full */
+#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
+
+static void imx_uart_console_early_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
+		cpu_relax();
+
+	writel_relaxed(ch, port->membase + URTX0);
+}
+
+static void imx_uart_console_early_write(struct console *con, const char *s,
+					 unsigned count)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
+}
+
+static int __init
+imx_console_early_setup(struct earlycon_device *dev, const char *opt)
+{
+	if (!dev->port.membase)
+		return -ENODEV;
+
+	dev->con->write = imx_uart_console_early_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
+OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
+
+MODULE_AUTHOR("NXP");
+MODULE_DESCRIPTION("IMX earlycon driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/ip22zilog.c b/drivers/tty/serial/ip22zilog.c
new file mode 100644
index 000000000..845ff706b
--- /dev/null
+++ b/drivers/tty/serial/ip22zilog.c
@@ -0,0 +1,1221 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Zilog serial chips found on SGI workstations and
+ * servers.  This driver could actually be made more generic.
+ *
+ * This is based on the drivers/serial/sunzilog.c code as of 2.6.0-test7 and the
+ * old drivers/sgi/char/sgiserial.c code which itself is based of the original
+ * drivers/sbus/char/zs.c code.  A lot of code has been simply moved over
+ * directly from there but much has been rewritten.  Credits therefore go out
+ * to David S. Miller, Eddie C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell
+ * for their work there.
+ *
+ *  Copyright (C) 2002 Ralf Baechle (ralf@linux-mips.org)
+ *  Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <asm/sgialib.h>
+#include <asm/sgi/ioc.h>
+#include <asm/sgi/hpc3.h>
+#include <asm/sgi/ip22.h>
+
+#include <linux/serial_core.h>
+
+#include "ip22zilog.h"
+
+/*
+ * On IP22 we need to delay after register accesses but we do not need to
+ * flush writes.
+ */
+#define ZSDELAY()		udelay(5)
+#define ZSDELAY_LONG()		udelay(20)
+#define ZS_WSYNC(channel)	do { } while (0)
+
+#define NUM_IP22ZILOG		1
+#define NUM_CHANNELS		(NUM_IP22ZILOG * 2)
+
+#define ZS_CLOCK		3672000	/* Zilog input clock rate. */
+#define ZS_CLOCK_DIVISOR	16      /* Divisor this driver uses. */
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_ip22zilog_port {
+	struct uart_port		port;
+
+	/* IRQ servicing chain.  */
+	struct uart_ip22zilog_port	*next;
+
+	/* Current values of Zilog write registers.  */
+	unsigned char			curregs[NUM_ZSREGS];
+
+	unsigned int			flags;
+#define IP22ZILOG_FLAG_IS_CONS		0x00000004
+#define IP22ZILOG_FLAG_IS_KGDB		0x00000008
+#define IP22ZILOG_FLAG_MODEM_STATUS	0x00000010
+#define IP22ZILOG_FLAG_IS_CHANNEL_A	0x00000020
+#define IP22ZILOG_FLAG_REGS_HELD	0x00000040
+#define IP22ZILOG_FLAG_TX_STOPPED	0x00000080
+#define IP22ZILOG_FLAG_TX_ACTIVE	0x00000100
+#define IP22ZILOG_FLAG_RESET_DONE	0x00000200
+
+	unsigned int			tty_break;
+
+	unsigned char			parity_mask;
+	unsigned char			prev_status;
+};
+
+#define ZILOG_CHANNEL_FROM_PORT(PORT)	((struct zilog_channel *)((PORT)->membase))
+#define UART_ZILOG(PORT)		((struct uart_ip22zilog_port *)(PORT))
+#define IP22ZILOG_GET_CURR_REG(PORT, REGNUM)		\
+	(UART_ZILOG(PORT)->curregs[REGNUM])
+#define IP22ZILOG_SET_CURR_REG(PORT, REGNUM, REGVAL)	\
+	((UART_ZILOG(PORT)->curregs[REGNUM]) = (REGVAL))
+#define ZS_IS_CONS(UP)	((UP)->flags & IP22ZILOG_FLAG_IS_CONS)
+#define ZS_IS_KGDB(UP)	((UP)->flags & IP22ZILOG_FLAG_IS_KGDB)
+#define ZS_WANTS_MODEM_STATUS(UP)	((UP)->flags & IP22ZILOG_FLAG_MODEM_STATUS)
+#define ZS_IS_CHANNEL_A(UP)	((UP)->flags & IP22ZILOG_FLAG_IS_CHANNEL_A)
+#define ZS_REGS_HELD(UP)	((UP)->flags & IP22ZILOG_FLAG_REGS_HELD)
+#define ZS_TX_STOPPED(UP)	((UP)->flags & IP22ZILOG_FLAG_TX_STOPPED)
+#define ZS_TX_ACTIVE(UP)	((UP)->flags & IP22ZILOG_FLAG_TX_ACTIVE)
+
+/* Reading and writing Zilog8530 registers.  The delays are to make this
+ * driver work on the IP22 which needs a settling delay after each chip
+ * register access, other machines handle this in hardware via auxiliary
+ * flip-flops which implement the settle time we do in software.
+ *
+ * The port lock must be held and local IRQs must be disabled
+ * when {read,write}_zsreg is invoked.
+ */
+static unsigned char read_zsreg(struct zilog_channel *channel,
+				unsigned char reg)
+{
+	unsigned char retval;
+
+	writeb(reg, &channel->control);
+	ZSDELAY();
+	retval = readb(&channel->control);
+	ZSDELAY();
+
+	return retval;
+}
+
+static void write_zsreg(struct zilog_channel *channel,
+			unsigned char reg, unsigned char value)
+{
+	writeb(reg, &channel->control);
+	ZSDELAY();
+	writeb(value, &channel->control);
+	ZSDELAY();
+}
+
+static void ip22zilog_clear_fifo(struct zilog_channel *channel)
+{
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		unsigned char regval;
+
+		regval = readb(&channel->control);
+		ZSDELAY();
+		if (regval & Rx_CH_AV)
+			break;
+
+		regval = read_zsreg(channel, R1);
+		readb(&channel->data);
+		ZSDELAY();
+
+		if (regval & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+			writeb(ERR_RES, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+		}
+	}
+}
+
+/* This function must only be called when the TX is not busy.  The UART
+ * port lock must be held and local interrupts disabled.
+ */
+static void __load_zsregs(struct zilog_channel *channel, unsigned char *regs)
+{
+	int i;
+
+	/* Let pending transmits finish.  */
+	for (i = 0; i < 1000; i++) {
+		unsigned char stat = read_zsreg(channel, R1);
+		if (stat & ALL_SNT)
+			break;
+		udelay(100);
+	}
+
+	writeb(ERR_RES, &channel->control);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+
+	ip22zilog_clear_fifo(channel);
+
+	/* Disable all interrupts.  */
+	write_zsreg(channel, R1,
+		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
+
+	/* Set parity, sync config, stop bits, and clock divisor.  */
+	write_zsreg(channel, R4, regs[R4]);
+
+	/* Set misc. TX/RX control bits.  */
+	write_zsreg(channel, R10, regs[R10]);
+
+	/* Set TX/RX controls sans the enable bits.  */
+	write_zsreg(channel, R3, regs[R3] & ~RxENAB);
+	write_zsreg(channel, R5, regs[R5] & ~TxENAB);
+
+	/* Synchronous mode config.  */
+	write_zsreg(channel, R6, regs[R6]);
+	write_zsreg(channel, R7, regs[R7]);
+
+	/* Don't mess with the interrupt vector (R2, unused by us) and
+	 * master interrupt control (R9).  We make sure this is setup
+	 * properly at probe time then never touch it again.
+	 */
+
+	/* Disable baud generator.  */
+	write_zsreg(channel, R14, regs[R14] & ~BRENAB);
+
+	/* Clock mode control.  */
+	write_zsreg(channel, R11, regs[R11]);
+
+	/* Lower and upper byte of baud rate generator divisor.  */
+	write_zsreg(channel, R12, regs[R12]);
+	write_zsreg(channel, R13, regs[R13]);
+
+	/* Now rewrite R14, with BRENAB (if set).  */
+	write_zsreg(channel, R14, regs[R14]);
+
+	/* External status interrupt control.  */
+	write_zsreg(channel, R15, regs[R15]);
+
+	/* Reset external status interrupts.  */
+	write_zsreg(channel, R0, RES_EXT_INT);
+	write_zsreg(channel, R0, RES_EXT_INT);
+
+	/* Rewrite R3/R5, this time without enables masked.  */
+	write_zsreg(channel, R3, regs[R3]);
+	write_zsreg(channel, R5, regs[R5]);
+
+	/* Rewrite R1, this time without IRQ enabled masked.  */
+	write_zsreg(channel, R1, regs[R1]);
+}
+
+/* Reprogram the Zilog channel HW registers with the copies found in the
+ * software state struct.  If the transmitter is busy, we defer this update
+ * until the next TX complete interrupt.  Else, we do it right now.
+ *
+ * The UART port lock must be held and local interrupts disabled.
+ */
+static void ip22zilog_maybe_update_regs(struct uart_ip22zilog_port *up,
+				       struct zilog_channel *channel)
+{
+	if (!ZS_REGS_HELD(up)) {
+		if (ZS_TX_ACTIVE(up)) {
+			up->flags |= IP22ZILOG_FLAG_REGS_HELD;
+		} else {
+			__load_zsregs(channel, up->curregs);
+		}
+	}
+}
+
+#define Rx_BRK 0x0100                   /* BREAK event software flag.  */
+#define Rx_SYS 0x0200                   /* SysRq event software flag.  */
+
+static bool ip22zilog_receive_chars(struct uart_ip22zilog_port *up,
+						  struct zilog_channel *channel)
+{
+	unsigned int r1;
+	u8 ch, flag;
+	bool push = up->port.state != NULL;
+
+	for (;;) {
+		ch = readb(&channel->control);
+		ZSDELAY();
+		if (!(ch & Rx_CH_AV))
+			break;
+
+		r1 = read_zsreg(channel, R1);
+		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+			writeb(ERR_RES, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+		}
+
+		ch = readb(&channel->data);
+		ZSDELAY();
+
+		ch &= up->parity_mask;
+
+		/* Handle the null char got when BREAK is removed.  */
+		if (!ch)
+			r1 |= up->tty_break;
+
+		/* A real serial line, record the character and status.  */
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | Rx_SYS | Rx_BRK)) {
+			up->tty_break = 0;
+
+			if (r1 & (Rx_SYS | Rx_BRK)) {
+				up->port.icount.brk++;
+				if (r1 & Rx_SYS)
+					continue;
+				r1 &= ~(PAR_ERR | CRC_ERR);
+			}
+			else if (r1 & PAR_ERR)
+				up->port.icount.parity++;
+			else if (r1 & CRC_ERR)
+				up->port.icount.frame++;
+			if (r1 & Rx_OVR)
+				up->port.icount.overrun++;
+			r1 &= up->port.read_status_mask;
+			if (r1 & Rx_BRK)
+				flag = TTY_BREAK;
+			else if (r1 & PAR_ERR)
+				flag = TTY_PARITY;
+			else if (r1 & CRC_ERR)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(&up->port, ch))
+			continue;
+
+		if (push)
+			uart_insert_char(&up->port, r1, Rx_OVR, ch, flag);
+	}
+	return push;
+}
+
+static void ip22zilog_status_handle(struct uart_ip22zilog_port *up,
+				   struct zilog_channel *channel)
+{
+	unsigned char status;
+
+	status = readb(&channel->control);
+	ZSDELAY();
+
+	writeb(RES_EXT_INT, &channel->control);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+
+	if (up->curregs[R15] & BRKIE) {
+		if ((status & BRK_ABRT) && !(up->prev_status & BRK_ABRT)) {
+			if (uart_handle_break(&up->port))
+				up->tty_break = Rx_SYS;
+			else
+				up->tty_break = Rx_BRK;
+		}
+	}
+
+	if (ZS_WANTS_MODEM_STATUS(up)) {
+		if (status & SYNC)
+			up->port.icount.dsr++;
+
+		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
+		 * But it does not tell us which bit has changed, we have to keep
+		 * track of this ourselves.
+		 */
+		if ((status ^ up->prev_status) ^ DCD)
+			uart_handle_dcd_change(&up->port,
+					       (status & DCD));
+		if ((status ^ up->prev_status) ^ CTS)
+			uart_handle_cts_change(&up->port,
+					       (status & CTS));
+
+		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+	}
+
+	up->prev_status = status;
+}
+
+static void ip22zilog_transmit_chars(struct uart_ip22zilog_port *up,
+				    struct zilog_channel *channel)
+{
+	struct circ_buf *xmit;
+
+	if (ZS_IS_CONS(up)) {
+		unsigned char status = readb(&channel->control);
+		ZSDELAY();
+
+		/* TX still busy?  Just wait for the next TX done interrupt.
+		 *
+		 * It can occur because of how we do serial console writes.  It would
+		 * be nice to transmit console writes just like we normally would for
+		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
+		 * easy because console writes cannot sleep.  One solution might be
+		 * to poll on enough port->xmit space becoming free.  -DaveM
+		 */
+		if (!(status & Tx_BUF_EMP))
+			return;
+	}
+
+	up->flags &= ~IP22ZILOG_FLAG_TX_ACTIVE;
+
+	if (ZS_REGS_HELD(up)) {
+		__load_zsregs(channel, up->curregs);
+		up->flags &= ~IP22ZILOG_FLAG_REGS_HELD;
+	}
+
+	if (ZS_TX_STOPPED(up)) {
+		up->flags &= ~IP22ZILOG_FLAG_TX_STOPPED;
+		goto ack_tx_int;
+	}
+
+	if (up->port.x_char) {
+		up->flags |= IP22ZILOG_FLAG_TX_ACTIVE;
+		writeb(up->port.x_char, &channel->data);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+
+		up->port.icount.tx++;
+		up->port.x_char = 0;
+		return;
+	}
+
+	if (up->port.state == NULL)
+		goto ack_tx_int;
+	xmit = &up->port.state->xmit;
+	if (uart_circ_empty(xmit))
+		goto ack_tx_int;
+	if (uart_tx_stopped(&up->port))
+		goto ack_tx_int;
+
+	up->flags |= IP22ZILOG_FLAG_TX_ACTIVE;
+	writeb(xmit->buf[xmit->tail], &channel->data);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+
+	uart_xmit_advance(&up->port, 1);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	return;
+
+ack_tx_int:
+	writeb(RES_Tx_P, &channel->control);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+}
+
+static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id)
+{
+	struct uart_ip22zilog_port *up = dev_id;
+
+	while (up) {
+		struct zilog_channel *channel
+			= ZILOG_CHANNEL_FROM_PORT(&up->port);
+		unsigned char r3;
+		bool push = false;
+
+		spin_lock(&up->port.lock);
+		r3 = read_zsreg(channel, R3);
+
+		/* Channel A */
+		if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
+			writeb(RES_H_IUS, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+
+			if (r3 & CHARxIP)
+				push = ip22zilog_receive_chars(up, channel);
+			if (r3 & CHAEXT)
+				ip22zilog_status_handle(up, channel);
+			if (r3 & CHATxIP)
+				ip22zilog_transmit_chars(up, channel);
+		}
+		spin_unlock(&up->port.lock);
+
+		if (push)
+			tty_flip_buffer_push(&up->port.state->port);
+
+		/* Channel B */
+		up = up->next;
+		channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+		push = false;
+
+		spin_lock(&up->port.lock);
+		if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
+			writeb(RES_H_IUS, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+
+			if (r3 & CHBRxIP)
+				push = ip22zilog_receive_chars(up, channel);
+			if (r3 & CHBEXT)
+				ip22zilog_status_handle(up, channel);
+			if (r3 & CHBTxIP)
+				ip22zilog_transmit_chars(up, channel);
+		}
+		spin_unlock(&up->port.lock);
+
+		if (push)
+			tty_flip_buffer_push(&up->port.state->port);
+
+		up = up->next;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/* A convenient way to quickly get R0 status.  The caller must _not_ hold the
+ * port lock, it is acquired here.
+ */
+static __inline__ unsigned char ip22zilog_read_channel_status(struct uart_port *port)
+{
+	struct zilog_channel *channel;
+	unsigned char status;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(port);
+	status = readb(&channel->control);
+	ZSDELAY();
+
+	return status;
+}
+
+/* The port lock is not held.  */
+static unsigned int ip22zilog_tx_empty(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned char status;
+	unsigned int ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	status = ip22zilog_read_channel_status(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (status & Tx_BUF_EMP)
+		ret = TIOCSER_TEMT;
+	else
+		ret = 0;
+
+	return ret;
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static unsigned int ip22zilog_get_mctrl(struct uart_port *port)
+{
+	unsigned char status;
+	unsigned int ret;
+
+	status = ip22zilog_read_channel_status(port);
+
+	ret = 0;
+	if (status & DCD)
+		ret |= TIOCM_CAR;
+	if (status & SYNC)
+		ret |= TIOCM_DSR;
+	if (status & CTS)
+		ret |= TIOCM_CTS;
+
+	return ret;
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void ip22zilog_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_ip22zilog_port *up =
+		container_of(port, struct uart_ip22zilog_port, port);
+	struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char set_bits, clear_bits;
+
+	set_bits = clear_bits = 0;
+
+	if (mctrl & TIOCM_RTS)
+		set_bits |= RTS;
+	else
+		clear_bits |= RTS;
+	if (mctrl & TIOCM_DTR)
+		set_bits |= DTR;
+	else
+		clear_bits |= DTR;
+
+	/* NOTE: Not subject to 'transmitter active' rule.  */
+	up->curregs[R5] |= set_bits;
+	up->curregs[R5] &= ~clear_bits;
+	write_zsreg(channel, R5, up->curregs[R5]);
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void ip22zilog_stop_tx(struct uart_port *port)
+{
+	struct uart_ip22zilog_port *up =
+		container_of(port, struct uart_ip22zilog_port, port);
+
+	up->flags |= IP22ZILOG_FLAG_TX_STOPPED;
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void ip22zilog_start_tx(struct uart_port *port)
+{
+	struct uart_ip22zilog_port *up =
+		container_of(port, struct uart_ip22zilog_port, port);
+	struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char status;
+
+	up->flags |= IP22ZILOG_FLAG_TX_ACTIVE;
+	up->flags &= ~IP22ZILOG_FLAG_TX_STOPPED;
+
+	status = readb(&channel->control);
+	ZSDELAY();
+
+	/* TX busy?  Just wait for the TX done interrupt.  */
+	if (!(status & Tx_BUF_EMP))
+		return;
+
+	/* Send the first character to jump-start the TX done
+	 * IRQ sending engine.
+	 */
+	if (port->x_char) {
+		writeb(port->x_char, &channel->data);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+
+		port->icount.tx++;
+		port->x_char = 0;
+	} else {
+		struct circ_buf *xmit = &port->state->xmit;
+
+		if (uart_circ_empty(xmit))
+			return;
+		writeb(xmit->buf[xmit->tail], &channel->data);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+
+		uart_xmit_advance(port, 1);
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&up->port);
+	}
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void ip22zilog_stop_rx(struct uart_port *port)
+{
+	struct uart_ip22zilog_port *up = UART_ZILOG(port);
+	struct zilog_channel *channel;
+
+	if (ZS_IS_CONS(up))
+		return;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(port);
+
+	/* Disable all RX interrupts.  */
+	up->curregs[R1] &= ~RxINT_MASK;
+	ip22zilog_maybe_update_regs(up, channel);
+}
+
+/* The port lock is held.  */
+static void ip22zilog_enable_ms(struct uart_port *port)
+{
+	struct uart_ip22zilog_port *up =
+		container_of(port, struct uart_ip22zilog_port, port);
+	struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char new_reg;
+
+	new_reg = up->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
+	if (new_reg != up->curregs[R15]) {
+		up->curregs[R15] = new_reg;
+
+		/* NOTE: Not subject to 'transmitter active' rule.  */
+		write_zsreg(channel, R15, up->curregs[R15]);
+	}
+}
+
+/* The port lock is not held.  */
+static void ip22zilog_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_ip22zilog_port *up =
+		container_of(port, struct uart_ip22zilog_port, port);
+	struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char set_bits, clear_bits, new_reg;
+	unsigned long flags;
+
+	set_bits = clear_bits = 0;
+
+	if (break_state)
+		set_bits |= SND_BRK;
+	else
+		clear_bits |= SND_BRK;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
+	if (new_reg != up->curregs[R5]) {
+		up->curregs[R5] = new_reg;
+
+		/* NOTE: Not subject to 'transmitter active' rule.  */
+		write_zsreg(channel, R5, up->curregs[R5]);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void __ip22zilog_reset(struct uart_ip22zilog_port *up)
+{
+	struct zilog_channel *channel;
+	int i;
+
+	if (up->flags & IP22ZILOG_FLAG_RESET_DONE)
+		return;
+
+	/* Let pending transmits finish.  */
+	channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+	for (i = 0; i < 1000; i++) {
+		unsigned char stat = read_zsreg(channel, R1);
+		if (stat & ALL_SNT)
+			break;
+		udelay(100);
+	}
+
+	if (!ZS_IS_CHANNEL_A(up)) {
+		up++;
+		channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+	}
+	write_zsreg(channel, R9, FHWRES);
+	ZSDELAY_LONG();
+	(void) read_zsreg(channel, R0);
+
+	up->flags |= IP22ZILOG_FLAG_RESET_DONE;
+	up->next->flags |= IP22ZILOG_FLAG_RESET_DONE;
+}
+
+static void __ip22zilog_startup(struct uart_ip22zilog_port *up)
+{
+	struct zilog_channel *channel;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+
+	__ip22zilog_reset(up);
+
+	__load_zsregs(channel, up->curregs);
+	/* set master interrupt enable */
+	write_zsreg(channel, R9, up->curregs[R9]);
+	up->prev_status = readb(&channel->control);
+
+	/* Enable receiver and transmitter.  */
+	up->curregs[R3] |= RxENAB;
+	up->curregs[R5] |= TxENAB;
+
+	up->curregs[R1] |= EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+	ip22zilog_maybe_update_regs(up, channel);
+}
+
+static int ip22zilog_startup(struct uart_port *port)
+{
+	struct uart_ip22zilog_port *up = UART_ZILOG(port);
+	unsigned long flags;
+
+	if (ZS_IS_CONS(up))
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+	__ip22zilog_startup(up);
+	spin_unlock_irqrestore(&port->lock, flags);
+	return 0;
+}
+
+/*
+ * The test for ZS_IS_CONS is explained by the following e-mail:
+ *****
+ * From: Russell King <rmk@arm.linux.org.uk>
+ * Date: Sun, 8 Dec 2002 10:18:38 +0000
+ *
+ * On Sun, Dec 08, 2002 at 02:43:36AM -0500, Pete Zaitcev wrote:
+ * > I boot my 2.5 boxes using "console=ttyS0,9600" argument,
+ * > and I noticed that something is not right with reference
+ * > counting in this case. It seems that when the console
+ * > is open by kernel initially, this is not accounted
+ * > as an open, and uart_startup is not called.
+ *
+ * That is correct.  We are unable to call uart_startup when the serial
+ * console is initialised because it may need to allocate memory (as
+ * request_irq does) and the memory allocators may not have been
+ * initialised.
+ *
+ * 1. initialise the port into a state where it can send characters in the
+ *    console write method.
+ *
+ * 2. don't do the actual hardware shutdown in your shutdown() method (but
+ *    do the normal software shutdown - ie, free irqs etc)
+ *****
+ */
+static void ip22zilog_shutdown(struct uart_port *port)
+{
+	struct uart_ip22zilog_port *up = UART_ZILOG(port);
+	struct zilog_channel *channel;
+	unsigned long flags;
+
+	if (ZS_IS_CONS(up))
+		return;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	channel = ZILOG_CHANNEL_FROM_PORT(port);
+
+	/* Disable receiver and transmitter.  */
+	up->curregs[R3] &= ~RxENAB;
+	up->curregs[R5] &= ~TxENAB;
+
+	/* Disable all interrupts and BRK assertion.  */
+	up->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
+	up->curregs[R5] &= ~SND_BRK;
+	ip22zilog_maybe_update_regs(up, channel);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Shared by TTY driver and serial console setup.  The port lock is held
+ * and local interrupts are disabled.
+ */
+static void
+ip22zilog_convert_to_zs(struct uart_ip22zilog_port *up, unsigned int cflag,
+		       unsigned int iflag, int brg)
+{
+
+	up->curregs[R10] = NRZ;
+	up->curregs[R11] = TCBR | RCBR;
+
+	/* Program BAUD and clock source. */
+	up->curregs[R4] &= ~XCLK_MASK;
+	up->curregs[R4] |= X16CLK;
+	up->curregs[R12] = brg & 0xff;
+	up->curregs[R13] = (brg >> 8) & 0xff;
+	up->curregs[R14] = BRENAB;
+
+	/* Character size, stop bits, and parity. */
+	up->curregs[3] &= ~RxN_MASK;
+	up->curregs[5] &= ~TxN_MASK;
+	switch (cflag & CSIZE) {
+	case CS5:
+		up->curregs[3] |= Rx5;
+		up->curregs[5] |= Tx5;
+		up->parity_mask = 0x1f;
+		break;
+	case CS6:
+		up->curregs[3] |= Rx6;
+		up->curregs[5] |= Tx6;
+		up->parity_mask = 0x3f;
+		break;
+	case CS7:
+		up->curregs[3] |= Rx7;
+		up->curregs[5] |= Tx7;
+		up->parity_mask = 0x7f;
+		break;
+	case CS8:
+	default:
+		up->curregs[3] |= Rx8;
+		up->curregs[5] |= Tx8;
+		up->parity_mask = 0xff;
+		break;
+	}
+	up->curregs[4] &= ~0x0c;
+	if (cflag & CSTOPB)
+		up->curregs[4] |= SB2;
+	else
+		up->curregs[4] |= SB1;
+	if (cflag & PARENB)
+		up->curregs[4] |= PAR_ENAB;
+	else
+		up->curregs[4] &= ~PAR_ENAB;
+	if (!(cflag & PARODD))
+		up->curregs[4] |= PAR_EVEN;
+	else
+		up->curregs[4] &= ~PAR_EVEN;
+
+	up->port.read_status_mask = Rx_OVR;
+	if (iflag & INPCK)
+		up->port.read_status_mask |= CRC_ERR | PAR_ERR;
+	if (iflag & (IGNBRK | BRKINT | PARMRK))
+		up->port.read_status_mask |= BRK_ABRT;
+
+	up->port.ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		up->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
+	if (iflag & IGNBRK) {
+		up->port.ignore_status_mask |= BRK_ABRT;
+		if (iflag & IGNPAR)
+			up->port.ignore_status_mask |= Rx_OVR;
+	}
+
+	if ((cflag & CREAD) == 0)
+		up->port.ignore_status_mask = 0xff;
+}
+
+/* The port lock is not held.  */
+static void
+ip22zilog_set_termios(struct uart_port *port, struct ktermios *termios,
+		      const struct ktermios *old)
+{
+	struct uart_ip22zilog_port *up =
+		container_of(port, struct uart_ip22zilog_port, port);
+	unsigned long flags;
+	int baud, brg;
+
+	baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+
+	ip22zilog_convert_to_zs(up, termios->c_cflag, termios->c_iflag, brg);
+
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->flags |= IP22ZILOG_FLAG_MODEM_STATUS;
+	else
+		up->flags &= ~IP22ZILOG_FLAG_MODEM_STATUS;
+
+	ip22zilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port));
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ip22zilog_type(struct uart_port *port)
+{
+	return "IP22-Zilog";
+}
+
+/* We do not request/release mappings of the registers here, this
+ * happens at early serial probe time.
+ */
+static void ip22zilog_release_port(struct uart_port *port)
+{
+}
+
+static int ip22zilog_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/* These do not need to do anything interesting either.  */
+static void ip22zilog_config_port(struct uart_port *port, int flags)
+{
+}
+
+/* We do not support letting the user mess with the divisor, IRQ, etc. */
+static int ip22zilog_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const struct uart_ops ip22zilog_pops = {
+	.tx_empty	=	ip22zilog_tx_empty,
+	.set_mctrl	=	ip22zilog_set_mctrl,
+	.get_mctrl	=	ip22zilog_get_mctrl,
+	.stop_tx	=	ip22zilog_stop_tx,
+	.start_tx	=	ip22zilog_start_tx,
+	.stop_rx	=	ip22zilog_stop_rx,
+	.enable_ms	=	ip22zilog_enable_ms,
+	.break_ctl	=	ip22zilog_break_ctl,
+	.startup	=	ip22zilog_startup,
+	.shutdown	=	ip22zilog_shutdown,
+	.set_termios	=	ip22zilog_set_termios,
+	.type		=	ip22zilog_type,
+	.release_port	=	ip22zilog_release_port,
+	.request_port	=	ip22zilog_request_port,
+	.config_port	=	ip22zilog_config_port,
+	.verify_port	=	ip22zilog_verify_port,
+};
+
+static struct uart_ip22zilog_port *ip22zilog_port_table;
+static struct zilog_layout **ip22zilog_chip_regs;
+
+static struct uart_ip22zilog_port *ip22zilog_irq_chain;
+static int zilog_irq = -1;
+
+static void * __init alloc_one_table(unsigned long size)
+{
+	return kzalloc(size, GFP_KERNEL);
+}
+
+static void __init ip22zilog_alloc_tables(void)
+{
+	ip22zilog_port_table = (struct uart_ip22zilog_port *)
+		alloc_one_table(NUM_CHANNELS * sizeof(struct uart_ip22zilog_port));
+	ip22zilog_chip_regs = (struct zilog_layout **)
+		alloc_one_table(NUM_IP22ZILOG * sizeof(struct zilog_layout *));
+
+	if (ip22zilog_port_table == NULL || ip22zilog_chip_regs == NULL) {
+		panic("IP22-Zilog: Cannot allocate IP22-Zilog tables.");
+	}
+}
+
+/* Get the address of the registers for IP22-Zilog instance CHIP.  */
+static struct zilog_layout * __init get_zs(int chip)
+{
+	unsigned long base;
+
+	if (chip < 0 || chip >= NUM_IP22ZILOG) {
+		panic("IP22-Zilog: Illegal chip number %d in get_zs.", chip);
+	}
+
+	/* Not probe-able, hard code it. */
+	base = (unsigned long) &sgioc->uart;
+
+	zilog_irq = SGI_SERIAL_IRQ;
+	request_mem_region(base, 8, "IP22-Zilog");
+
+	return (struct zilog_layout *) base;
+}
+
+#define ZS_PUT_CHAR_MAX_DELAY	2000	/* 10 ms */
+
+#ifdef CONFIG_SERIAL_IP22_ZILOG_CONSOLE
+static void ip22zilog_put_char(struct uart_port *port, unsigned char ch)
+{
+	struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	int loops = ZS_PUT_CHAR_MAX_DELAY;
+
+	/* This is a timed polling loop so do not switch the explicit
+	 * udelay with ZSDELAY as that is a NOP on some platforms.  -DaveM
+	 */
+	do {
+		unsigned char val = readb(&channel->control);
+		if (val & Tx_BUF_EMP) {
+			ZSDELAY();
+			break;
+		}
+		udelay(5);
+	} while (--loops);
+
+	writeb(ch, &channel->data);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+}
+
+static void
+ip22zilog_console_write(struct console *con, const char *s, unsigned int count)
+{
+	struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index];
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	uart_console_write(&up->port, s, count, ip22zilog_put_char);
+	udelay(2);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ip22zilog_console_setup(struct console *con, char *options)
+{
+	struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index];
+	unsigned long flags;
+	int baud = 9600, bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	up->flags |= IP22ZILOG_FLAG_IS_CONS;
+
+	printk(KERN_INFO "Console: ttyS%d (IP22-Zilog)\n", con->index);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->curregs[R15] |= BRKIE;
+
+	__ip22zilog_startup(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	return uart_set_options(&up->port, con, baud, parity, bits, flow);
+}
+
+static struct uart_driver ip22zilog_reg;
+
+static struct console ip22zilog_console = {
+	.name	=	"ttyS",
+	.write	=	ip22zilog_console_write,
+	.device	=	uart_console_device,
+	.setup	=	ip22zilog_console_setup,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data	=	&ip22zilog_reg,
+};
+#endif /* CONFIG_SERIAL_IP22_ZILOG_CONSOLE */
+
+static struct uart_driver ip22zilog_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "serial",
+	.dev_name	= "ttyS",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= NUM_CHANNELS,
+#ifdef CONFIG_SERIAL_IP22_ZILOG_CONSOLE
+	.cons		= &ip22zilog_console,
+#endif
+};
+
+static void __init ip22zilog_prepare(void)
+{
+	unsigned char sysrq_on = IS_ENABLED(CONFIG_SERIAL_IP22_ZILOG_CONSOLE);
+	struct uart_ip22zilog_port *up;
+	struct zilog_layout *rp;
+	int channel, chip;
+
+	/*
+	 * Temporary fix.
+	 */
+	for (channel = 0; channel < NUM_CHANNELS; channel++)
+		spin_lock_init(&ip22zilog_port_table[channel].port.lock);
+
+	ip22zilog_irq_chain = &ip22zilog_port_table[NUM_CHANNELS - 1];
+        up = &ip22zilog_port_table[0];
+	for (channel = NUM_CHANNELS - 1 ; channel > 0; channel--)
+		up[channel].next = &up[channel - 1];
+	up[channel].next = NULL;
+
+	for (chip = 0; chip < NUM_IP22ZILOG; chip++) {
+		if (!ip22zilog_chip_regs[chip]) {
+			ip22zilog_chip_regs[chip] = rp = get_zs(chip);
+
+			up[(chip * 2) + 0].port.membase = (char *) &rp->channelB;
+			up[(chip * 2) + 1].port.membase = (char *) &rp->channelA;
+
+			/* In theory mapbase is the physical address ...  */
+			up[(chip * 2) + 0].port.mapbase =
+				(unsigned long) ioremap((unsigned long) &rp->channelB, 8);
+			up[(chip * 2) + 1].port.mapbase =
+				(unsigned long) ioremap((unsigned long) &rp->channelA, 8);
+		}
+
+		/* Channel A */
+		up[(chip * 2) + 0].port.iotype = UPIO_MEM;
+		up[(chip * 2) + 0].port.irq = zilog_irq;
+		up[(chip * 2) + 0].port.uartclk = ZS_CLOCK;
+		up[(chip * 2) + 0].port.fifosize = 1;
+		up[(chip * 2) + 0].port.has_sysrq = sysrq_on;
+		up[(chip * 2) + 0].port.ops = &ip22zilog_pops;
+		up[(chip * 2) + 0].port.type = PORT_IP22ZILOG;
+		up[(chip * 2) + 0].port.flags = 0;
+		up[(chip * 2) + 0].port.line = (chip * 2) + 0;
+		up[(chip * 2) + 0].flags = 0;
+
+		/* Channel B */
+		up[(chip * 2) + 1].port.iotype = UPIO_MEM;
+		up[(chip * 2) + 1].port.irq = zilog_irq;
+		up[(chip * 2) + 1].port.uartclk = ZS_CLOCK;
+		up[(chip * 2) + 1].port.fifosize = 1;
+		up[(chip * 2) + 1].port.has_sysrq = sysrq_on;
+		up[(chip * 2) + 1].port.ops = &ip22zilog_pops;
+		up[(chip * 2) + 1].port.type = PORT_IP22ZILOG;
+		up[(chip * 2) + 1].port.line = (chip * 2) + 1;
+		up[(chip * 2) + 1].flags |= IP22ZILOG_FLAG_IS_CHANNEL_A;
+	}
+
+	for (channel = 0; channel < NUM_CHANNELS; channel++) {
+		struct uart_ip22zilog_port *up = &ip22zilog_port_table[channel];
+		int brg;
+
+		/* Normal serial TTY. */
+		up->parity_mask = 0xff;
+		up->curregs[R1] = EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+		up->curregs[R4] = PAR_EVEN | X16CLK | SB1;
+		up->curregs[R3] = RxENAB | Rx8;
+		up->curregs[R5] = TxENAB | Tx8;
+		up->curregs[R9] = NV | MIE;
+		up->curregs[R10] = NRZ;
+		up->curregs[R11] = TCBR | RCBR;
+		brg = BPS_TO_BRG(9600, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+		up->curregs[R12] = (brg & 0xff);
+		up->curregs[R13] = (brg >> 8) & 0xff;
+		up->curregs[R14] = BRENAB;
+	}
+}
+
+static int __init ip22zilog_ports_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Serial: IP22 Zilog driver (%d chips).\n", NUM_IP22ZILOG);
+
+	ip22zilog_prepare();
+
+	if (request_irq(zilog_irq, ip22zilog_interrupt, 0,
+			"IP22-Zilog", ip22zilog_irq_chain)) {
+		panic("IP22-Zilog: Unable to register zs interrupt handler.\n");
+	}
+
+	ret = uart_register_driver(&ip22zilog_reg);
+	if (ret == 0) {
+		int i;
+
+		for (i = 0; i < NUM_CHANNELS; i++) {
+			struct uart_ip22zilog_port *up = &ip22zilog_port_table[i];
+
+			uart_add_one_port(&ip22zilog_reg, &up->port);
+		}
+	}
+
+	return ret;
+}
+
+static int __init ip22zilog_init(void)
+{
+	/* IP22 Zilog setup is hard coded, no probing to do.  */
+	ip22zilog_alloc_tables();
+	ip22zilog_ports_init();
+
+	return 0;
+}
+
+static void __exit ip22zilog_exit(void)
+{
+	int i;
+	struct uart_ip22zilog_port *up;
+
+	for (i = 0; i < NUM_CHANNELS; i++) {
+		up = &ip22zilog_port_table[i];
+
+		uart_remove_one_port(&ip22zilog_reg, &up->port);
+	}
+
+	/* Free IO mem */
+	up = &ip22zilog_port_table[0];
+	for (i = 0; i < NUM_IP22ZILOG; i++) {
+		if (up[(i * 2) + 0].port.mapbase) {
+		   iounmap((void*)up[(i * 2) + 0].port.mapbase);
+		   up[(i * 2) + 0].port.mapbase = 0;
+		}
+		if (up[(i * 2) + 1].port.mapbase) {
+			iounmap((void*)up[(i * 2) + 1].port.mapbase);
+			up[(i * 2) + 1].port.mapbase = 0;
+		}
+	}
+
+	uart_unregister_driver(&ip22zilog_reg);
+}
+
+module_init(ip22zilog_init);
+module_exit(ip22zilog_exit);
+
+/* David wrote it but I'm to blame for the bugs ...  */
+MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
+MODULE_DESCRIPTION("SGI Zilog serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/ip22zilog.h b/drivers/tty/serial/ip22zilog.h
new file mode 100644
index 000000000..b52801fe2
--- /dev/null
+++ b/drivers/tty/serial/ip22zilog.h
@@ -0,0 +1,282 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _IP22_ZILOG_H
+#define _IP22_ZILOG_H
+
+#include <asm/byteorder.h>
+
+struct zilog_channel {
+#ifdef __BIG_ENDIAN
+	volatile unsigned char unused0[3];
+	volatile unsigned char control;
+	volatile unsigned char unused1[3];
+	volatile unsigned char data;
+#else /* __LITTLE_ENDIAN */
+	volatile unsigned char control;
+	volatile unsigned char unused0[3];
+	volatile unsigned char data;
+	volatile unsigned char unused1[3];
+#endif
+};
+
+struct zilog_layout {
+	struct zilog_channel channelB;
+	struct zilog_channel channelA;
+};
+
+#define NUM_ZSREGS    16
+
+/* Conversion routines to/from brg time constants from/to bits
+ * per second.
+ */
+#define BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
+#define BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)
+
+/* The Zilog register set */
+
+#define	FLAG	0x7e
+
+/* Write Register 0 */
+#define	R0	0		/* Register selects */
+#define	R1	1
+#define	R2	2
+#define	R3	3
+#define	R4	4
+#define	R5	5
+#define	R6	6
+#define	R7	7
+#define	R8	8
+#define	R9	9
+#define	R10	10
+#define	R11	11
+#define	R12	12
+#define	R13	13
+#define	R14	14
+#define	R15	15
+
+#define	NULLCODE	0	/* Null Code */
+#define	POINT_HIGH	0x8	/* Select upper half of registers */
+#define	RES_EXT_INT	0x10	/* Reset Ext. Status Interrupts */
+#define	SEND_ABORT	0x18	/* HDLC Abort */
+#define	RES_RxINT_FC	0x20	/* Reset RxINT on First Character */
+#define	RES_Tx_P	0x28	/* Reset TxINT Pending */
+#define	ERR_RES		0x30	/* Error Reset */
+#define	RES_H_IUS	0x38	/* Reset highest IUS */
+
+#define	RES_Rx_CRC	0x40	/* Reset Rx CRC Checker */
+#define	RES_Tx_CRC	0x80	/* Reset Tx CRC Checker */
+#define	RES_EOM_L	0xC0	/* Reset EOM latch */
+
+/* Write Register 1 */
+
+#define	EXT_INT_ENAB	0x1	/* Ext Int Enable */
+#define	TxINT_ENAB	0x2	/* Tx Int Enable */
+#define	PAR_SPEC	0x4	/* Parity is special condition */
+
+#define	RxINT_DISAB	0	/* Rx Int Disable */
+#define	RxINT_FCERR	0x8	/* Rx Int on First Character Only or Error */
+#define	INT_ALL_Rx	0x10	/* Int on all Rx Characters or error */
+#define	INT_ERR_Rx	0x18	/* Int on error only */
+#define RxINT_MASK	0x18
+
+#define	WT_RDY_RT	0x20	/* Wait/Ready on R/T */
+#define	WT_FN_RDYFN	0x40	/* Wait/FN/Ready FN */
+#define	WT_RDY_ENAB	0x80	/* Wait/Ready Enable */
+
+/* Write Register #2 (Interrupt Vector) */
+
+/* Write Register 3 */
+
+#define	RxENAB  	0x1	/* Rx Enable */
+#define	SYNC_L_INH	0x2	/* Sync Character Load Inhibit */
+#define	ADD_SM		0x4	/* Address Search Mode (SDLC) */
+#define	RxCRC_ENAB	0x8	/* Rx CRC Enable */
+#define	ENT_HM		0x10	/* Enter Hunt Mode */
+#define	AUTO_ENAB	0x20	/* Auto Enables */
+#define	Rx5		0x0	/* Rx 5 Bits/Character */
+#define	Rx7		0x40	/* Rx 7 Bits/Character */
+#define	Rx6		0x80	/* Rx 6 Bits/Character */
+#define	Rx8		0xc0	/* Rx 8 Bits/Character */
+#define RxN_MASK	0xc0
+
+/* Write Register 4 */
+
+#define	PAR_ENAB	0x1	/* Parity Enable */
+#define	PAR_EVEN	0x2	/* Parity Even/Odd* */
+
+#define	SYNC_ENAB	0	/* Sync Modes Enable */
+#define	SB1		0x4	/* 1 stop bit/char */
+#define	SB15		0x8	/* 1.5 stop bits/char */
+#define	SB2		0xc	/* 2 stop bits/char */
+
+#define	MONSYNC		0	/* 8 Bit Sync character */
+#define	BISYNC		0x10	/* 16 bit sync character */
+#define	SDLC		0x20	/* SDLC Mode (01111110 Sync Flag) */
+#define	EXTSYNC		0x30	/* External Sync Mode */
+
+#define	X1CLK		0x0	/* x1 clock mode */
+#define	X16CLK		0x40	/* x16 clock mode */
+#define	X32CLK		0x80	/* x32 clock mode */
+#define	X64CLK		0xC0	/* x64 clock mode */
+#define XCLK_MASK	0xC0
+
+/* Write Register 5 */
+
+#define	TxCRC_ENAB	0x1	/* Tx CRC Enable */
+#define	RTS		0x2	/* RTS */
+#define	SDLC_CRC	0x4	/* SDLC/CRC-16 */
+#define	TxENAB		0x8	/* Tx Enable */
+#define	SND_BRK		0x10	/* Send Break */
+#define	Tx5		0x0	/* Tx 5 bits (or less)/character */
+#define	Tx7		0x20	/* Tx 7 bits/character */
+#define	Tx6		0x40	/* Tx 6 bits/character */
+#define	Tx8		0x60	/* Tx 8 bits/character */
+#define TxN_MASK	0x60
+#define	DTR		0x80	/* DTR */
+
+/* Write Register 6 (Sync bits 0-7/SDLC Address Field) */
+
+/* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
+
+/* Write Register 8 (transmit buffer) */
+
+/* Write Register 9 (Master interrupt control) */
+#define	VIS	1	/* Vector Includes Status */
+#define	NV	2	/* No Vector */
+#define	DLC	4	/* Disable Lower Chain */
+#define	MIE	8	/* Master Interrupt Enable */
+#define	STATHI	0x10	/* Status high */
+#define	NORESET	0	/* No reset on write to R9 */
+#define	CHRB	0x40	/* Reset channel B */
+#define	CHRA	0x80	/* Reset channel A */
+#define	FHWRES	0xc0	/* Force hardware reset */
+
+/* Write Register 10 (misc control bits) */
+#define	BIT6	1	/* 6 bit/8bit sync */
+#define	LOOPMODE 2	/* SDLC Loop mode */
+#define	ABUNDER	4	/* Abort/flag on SDLC xmit underrun */
+#define	MARKIDLE 8	/* Mark/flag on idle */
+#define	GAOP	0x10	/* Go active on poll */
+#define	NRZ	0	/* NRZ mode */
+#define	NRZI	0x20	/* NRZI mode */
+#define	FM1	0x40	/* FM1 (transition = 1) */
+#define	FM0	0x60	/* FM0 (transition = 0) */
+#define	CRCPS	0x80	/* CRC Preset I/O */
+
+/* Write Register 11 (Clock Mode control) */
+#define	TRxCXT	0	/* TRxC = Xtal output */
+#define	TRxCTC	1	/* TRxC = Transmit clock */
+#define	TRxCBR	2	/* TRxC = BR Generator Output */
+#define	TRxCDP	3	/* TRxC = DPLL output */
+#define	TRxCOI	4	/* TRxC O/I */
+#define	TCRTxCP	0	/* Transmit clock = RTxC pin */
+#define	TCTRxCP	8	/* Transmit clock = TRxC pin */
+#define	TCBR	0x10	/* Transmit clock = BR Generator output */
+#define	TCDPLL	0x18	/* Transmit clock = DPLL output */
+#define	RCRTxCP	0	/* Receive clock = RTxC pin */
+#define	RCTRxCP	0x20	/* Receive clock = TRxC pin */
+#define	RCBR	0x40	/* Receive clock = BR Generator output */
+#define	RCDPLL	0x60	/* Receive clock = DPLL output */
+#define	RTxCX	0x80	/* RTxC Xtal/No Xtal */
+
+/* Write Register 12 (lower byte of baud rate generator time constant) */
+
+/* Write Register 13 (upper byte of baud rate generator time constant) */
+
+/* Write Register 14 (Misc control bits) */
+#define	BRENAB 	1	/* Baud rate generator enable */
+#define	BRSRC	2	/* Baud rate generator source */
+#define	DTRREQ	4	/* DTR/Request function */
+#define	AUTOECHO 8	/* Auto Echo */
+#define	LOOPBAK	0x10	/* Local loopback */
+#define	SEARCH	0x20	/* Enter search mode */
+#define	RMC	0x40	/* Reset missing clock */
+#define	DISDPLL	0x60	/* Disable DPLL */
+#define	SSBR	0x80	/* Set DPLL source = BR generator */
+#define	SSRTxC	0xa0	/* Set DPLL source = RTxC */
+#define	SFMM	0xc0	/* Set FM mode */
+#define	SNRZI	0xe0	/* Set NRZI mode */
+
+/* Write Register 15 (external/status interrupt control) */
+#define	ZCIE	2	/* Zero count IE */
+#define	DCDIE	8	/* DCD IE */
+#define	SYNCIE	0x10	/* Sync/hunt IE */
+#define	CTSIE	0x20	/* CTS IE */
+#define	TxUIE	0x40	/* Tx Underrun/EOM IE */
+#define	BRKIE	0x80	/* Break/Abort IE */
+
+
+/* Read Register 0 */
+#define	Rx_CH_AV	0x1	/* Rx Character Available */
+#define	ZCOUNT		0x2	/* Zero count */
+#define	Tx_BUF_EMP	0x4	/* Tx Buffer empty */
+#define	DCD		0x8	/* DCD */
+#define	SYNC		0x10	/* Sync/hunt */
+#define	CTS		0x20	/* CTS */
+#define	TxEOM		0x40	/* Tx underrun */
+#define	BRK_ABRT	0x80	/* Break/Abort */
+
+/* Read Register 1 */
+#define	ALL_SNT		0x1	/* All sent */
+/* Residue Data for 8 Rx bits/char programmed */
+#define	RES3		0x8	/* 0/3 */
+#define	RES4		0x4	/* 0/4 */
+#define	RES5		0xc	/* 0/5 */
+#define	RES6		0x2	/* 0/6 */
+#define	RES7		0xa	/* 0/7 */
+#define	RES8		0x6	/* 0/8 */
+#define	RES18		0xe	/* 1/8 */
+#define	RES28		0x0	/* 2/8 */
+/* Special Rx Condition Interrupts */
+#define	PAR_ERR		0x10	/* Parity error */
+#define	Rx_OVR		0x20	/* Rx Overrun Error */
+#define	CRC_ERR		0x40	/* CRC/Framing Error */
+#define	END_FR		0x80	/* End of Frame (SDLC) */
+
+/* Read Register 2 (channel b only) - Interrupt vector */
+#define CHB_Tx_EMPTY	0x00
+#define CHB_EXT_STAT	0x02
+#define CHB_Rx_AVAIL	0x04
+#define CHB_SPECIAL	0x06
+#define CHA_Tx_EMPTY	0x08
+#define CHA_EXT_STAT	0x0a
+#define CHA_Rx_AVAIL	0x0c
+#define CHA_SPECIAL	0x0e
+#define STATUS_MASK	0x0e
+
+/* Read Register 3 (interrupt pending register) ch a only */
+#define	CHBEXT	0x1		/* Channel B Ext/Stat IP */
+#define	CHBTxIP	0x2		/* Channel B Tx IP */
+#define	CHBRxIP	0x4		/* Channel B Rx IP */
+#define	CHAEXT	0x8		/* Channel A Ext/Stat IP */
+#define	CHATxIP	0x10		/* Channel A Tx IP */
+#define	CHARxIP	0x20		/* Channel A Rx IP */
+
+/* Read Register 8 (receive data register) */
+
+/* Read Register 10  (misc status bits) */
+#define	ONLOOP	2		/* On loop */
+#define	LOOPSEND 0x10		/* Loop sending */
+#define	CLK2MIS	0x40		/* Two clocks missing */
+#define	CLK1MIS	0x80		/* One clock missing */
+
+/* Read Register 12 (lower byte of baud rate generator constant) */
+
+/* Read Register 13 (upper byte of baud rate generator constant) */
+
+/* Read Register 15 (value of WR 15) */
+
+/* Misc macros */
+#define ZS_CLEARERR(channel)    do { writeb(ERR_RES, &channel->control); \
+				     udelay(5); } while(0)
+
+#define ZS_CLEARSTAT(channel)   do { writeb(RES_EXT_INT, &channel->control); \
+				     udelay(5); } while(0)
+
+#define ZS_CLEARFIFO(channel)   do { readb(&channel->data); \
+				     udelay(2); \
+				     readb(&channel->data); \
+				     udelay(2); \
+				     readb(&channel->data); \
+				     udelay(2); } while(0)
+
+#endif /* _IP22_ZILOG_H */
diff --git a/drivers/tty/serial/jsm/Makefile b/drivers/tty/serial/jsm/Makefile
new file mode 100644
index 000000000..4f2dbada7
--- /dev/null
+++ b/drivers/tty/serial/jsm/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for Jasmine adapter
+#
+
+obj-$(CONFIG_SERIAL_JSM) += jsm.o
+
+jsm-objs :=    jsm_driver.o jsm_neo.o jsm_tty.o jsm_cls.o
+
diff --git a/drivers/tty/serial/jsm/jsm.h b/drivers/tty/serial/jsm/jsm.h
new file mode 100644
index 000000000..8489c07f4
--- /dev/null
+++ b/drivers/tty/serial/jsm/jsm.h
@@ -0,0 +1,438 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/************************************************************************
+ * Copyright 2003 Digi International (www.digi.com)
+ *
+ * Copyright (C) 2004 IBM Corporation. All rights reserved.
+ *
+ * Contact Information:
+ * Scott H Kilau <Scott_Kilau@digi.com>
+ * Wendy Xiong   <wendyx@us.ibm.com>
+ *
+ ***********************************************************************/
+
+#ifndef __JSM_DRIVER_H
+#define __JSM_DRIVER_H
+
+#include <linux/kernel.h>
+#include <linux/types.h>	/* To pick up the varions Linux types */
+#include <linux/tty.h>
+#include <linux/serial_core.h>
+#include <linux/device.h>
+
+/*
+ * Debugging levels can be set using debug insmod variable
+ * They can also be compiled out completely.
+ */
+enum {
+	DBG_INIT	= 0x01,
+	DBG_BASIC	= 0x02,
+	DBG_CORE	= 0x04,
+	DBG_OPEN	= 0x08,
+	DBG_CLOSE	= 0x10,
+	DBG_READ	= 0x20,
+	DBG_WRITE	= 0x40,
+	DBG_IOCTL	= 0x80,
+	DBG_PROC	= 0x100,
+	DBG_PARAM	= 0x200,
+	DBG_PSCAN	= 0x400,
+	DBG_EVENT	= 0x800,
+	DBG_DRAIN	= 0x1000,
+	DBG_MSIGS	= 0x2000,
+	DBG_MGMT	= 0x4000,
+	DBG_INTR	= 0x8000,
+	DBG_CARR	= 0x10000,
+};
+
+#define jsm_dbg(nlevel, pdev, fmt, ...)				\
+do {								\
+	if (DBG_##nlevel & jsm_debug)				\
+		dev_dbg(pdev->dev, fmt, ##__VA_ARGS__);		\
+} while (0)
+
+#define	MAXLINES	256
+#define MAXPORTS	8
+#define MAX_STOPS_SENT	5
+
+/* Board ids */
+#define PCI_DEVICE_ID_CLASSIC_4		0x0028
+#define PCI_DEVICE_ID_CLASSIC_8		0x0029
+#define PCI_DEVICE_ID_CLASSIC_4_422	0x00D0
+#define PCI_DEVICE_ID_CLASSIC_8_422	0x00D1
+#define PCI_DEVICE_ID_NEO_4             0x00B0
+#define PCI_DEVICE_ID_NEO_1_422         0x00CC
+#define PCI_DEVICE_ID_NEO_1_422_485     0x00CD
+#define PCI_DEVICE_ID_NEO_2_422_485     0x00CE
+#define PCIE_DEVICE_ID_NEO_8            0x00F0
+#define PCIE_DEVICE_ID_NEO_4            0x00F1
+#define PCIE_DEVICE_ID_NEO_4RJ45        0x00F2
+#define PCIE_DEVICE_ID_NEO_8RJ45        0x00F3
+
+/* Board type definitions */
+
+#define T_NEO		0000
+#define T_CLASSIC	0001
+#define T_PCIBUS	0400
+
+/* Board State Definitions */
+
+#define BD_RUNNING	0x0
+#define BD_REASON	0x7f
+#define BD_NOTFOUND	0x1
+#define BD_NOIOPORT	0x2
+#define BD_NOMEM	0x3
+#define BD_NOBIOS	0x4
+#define BD_NOFEP	0x5
+#define BD_FAILED	0x6
+#define BD_ALLOCATED	0x7
+#define BD_TRIBOOT	0x8
+#define BD_BADKME	0x80
+
+
+/* 4 extra for alignment play space */
+#define WRITEBUFLEN	((4096) + 4)
+
+#define JSM_VERSION	"jsm: 1.2-1-INKERNEL"
+#define JSM_PARTNUM	"40002438_A-INKERNEL"
+
+struct jsm_board;
+struct jsm_channel;
+
+/************************************************************************
+ * Per board operations structure					*
+ ************************************************************************/
+struct board_ops {
+	irq_handler_t intr;
+	void (*uart_init)(struct jsm_channel *ch);
+	void (*uart_off)(struct jsm_channel *ch);
+	void (*param)(struct jsm_channel *ch);
+	void (*assert_modem_signals)(struct jsm_channel *ch);
+	void (*flush_uart_write)(struct jsm_channel *ch);
+	void (*flush_uart_read)(struct jsm_channel *ch);
+	void (*disable_receiver)(struct jsm_channel *ch);
+	void (*enable_receiver)(struct jsm_channel *ch);
+	void (*send_break)(struct jsm_channel *ch);
+	void (*clear_break)(struct jsm_channel *ch);
+	void (*send_start_character)(struct jsm_channel *ch);
+	void (*send_stop_character)(struct jsm_channel *ch);
+	void (*copy_data_from_queue_to_uart)(struct jsm_channel *ch);
+	u32 (*get_uart_bytes_left)(struct jsm_channel *ch);
+	void (*send_immediate_char)(struct jsm_channel *ch, unsigned char);
+};
+
+
+/*
+ *	Per-board information
+ */
+struct jsm_board
+{
+	int		boardnum;	/* Board number: 0-32 */
+
+	int		type;		/* Type of board */
+	u8		rev;		/* PCI revision ID */
+	struct pci_dev	*pci_dev;
+	u32		maxports;	/* MAX ports this board can handle */
+
+	spinlock_t	bd_intr_lock;	/* Used to protect the poller tasklet and
+					 * the interrupt routine from each other.
+					 */
+
+	u32		nasync;		/* Number of ports on card */
+
+	u32		irq;		/* Interrupt request number */
+
+	u64		membase;	/* Start of base memory of the card */
+	u64		membase_end;	/* End of base memory of the card */
+
+	u8	__iomem *re_map_membase;/* Remapped memory of the card */
+
+	u64		iobase;		/* Start of io base of the card */
+	u64		iobase_end;	/* End of io base of the card */
+
+	u32		bd_uart_offset;	/* Space between each UART */
+
+	struct jsm_channel *channels[MAXPORTS]; /* array of pointers to our channels. */
+
+	u32		bd_dividend;	/* Board/UARTs specific dividend */
+
+	struct board_ops *bd_ops;
+
+	struct list_head jsm_board_entry;
+};
+
+/************************************************************************
+ * Device flag definitions for ch_flags.
+ ************************************************************************/
+#define CH_PRON		0x0001		/* Printer on string		*/
+#define CH_STOP		0x0002		/* Output is stopped		*/
+#define CH_STOPI	0x0004		/* Input is stopped		*/
+#define CH_CD		0x0008		/* Carrier is present		*/
+#define CH_FCAR		0x0010		/* Carrier forced on		*/
+#define CH_HANGUP	0x0020		/* Hangup received		*/
+
+#define CH_RECEIVER_OFF	0x0040		/* Receiver is off		*/
+#define CH_OPENING	0x0080		/* Port in fragile open state	*/
+#define CH_CLOSING	0x0100		/* Port in fragile close state	*/
+#define CH_FIFO_ENABLED 0x0200		/* Port has FIFOs enabled	*/
+#define CH_TX_FIFO_EMPTY 0x0400		/* TX Fifo is completely empty	*/
+#define CH_TX_FIFO_LWM	0x0800		/* TX Fifo is below Low Water	*/
+#define CH_BREAK_SENDING 0x1000		/* Break is being sent		*/
+#define CH_LOOPBACK 0x2000		/* Channel is in lookback mode	*/
+#define CH_BAUD0	0x08000		/* Used for checking B0 transitions */
+
+/* Our Read/Error queue sizes */
+#define RQUEUEMASK	0x1FFF		/* 8 K - 1 */
+#define EQUEUEMASK	0x1FFF		/* 8 K - 1 */
+#define RQUEUESIZE	(RQUEUEMASK + 1)
+#define EQUEUESIZE	RQUEUESIZE
+
+
+/************************************************************************
+ * Channel information structure.
+ ************************************************************************/
+struct jsm_channel {
+	struct uart_port uart_port;
+	struct jsm_board	*ch_bd;		/* Board structure pointer	*/
+
+	spinlock_t	ch_lock;	/* provide for serialization */
+	wait_queue_head_t ch_flags_wait;
+
+	u32		ch_portnum;	/* Port number, 0 offset.	*/
+	u32		ch_open_count;	/* open count			*/
+	u32		ch_flags;	/* Channel flags		*/
+
+	u64		ch_close_delay;	/* How long we should drop RTS/DTR for */
+
+	tcflag_t	ch_c_iflag;	/* channel iflags		*/
+	tcflag_t	ch_c_cflag;	/* channel cflags		*/
+	tcflag_t	ch_c_oflag;	/* channel oflags		*/
+	tcflag_t	ch_c_lflag;	/* channel lflags		*/
+	u8		ch_stopc;	/* Stop character		*/
+	u8		ch_startc;	/* Start character		*/
+
+	u8		ch_mostat;	/* FEP output modem status	*/
+	u8		ch_mistat;	/* FEP input modem status	*/
+
+	/* Pointers to the "mapped" UART structs */
+	struct neo_uart_struct __iomem *ch_neo_uart; /* NEO card */
+	struct cls_uart_struct __iomem *ch_cls_uart; /* Classic card */
+
+	u8		ch_cached_lsr;	/* Cached value of the LSR register */
+
+	u8		*ch_rqueue;	/* Our read queue buffer - malloc'ed */
+	u16		ch_r_head;	/* Head location of the read queue */
+	u16		ch_r_tail;	/* Tail location of the read queue */
+
+	u8		*ch_equeue;	/* Our error queue buffer - malloc'ed */
+	u16		ch_e_head;	/* Head location of the error queue */
+	u16		ch_e_tail;	/* Tail location of the error queue */
+
+	u64		ch_rxcount;	/* total of data received so far */
+	u64		ch_txcount;	/* total of data transmitted so far */
+
+	u8		ch_r_tlevel;	/* Receive Trigger level */
+	u8		ch_t_tlevel;	/* Transmit Trigger level */
+
+	u8		ch_r_watermark;	/* Receive Watermark */
+
+
+	u32		ch_stops_sent;	/* How many times I have sent a stop character
+					 * to try to stop the other guy sending.
+					 */
+	u64		ch_err_parity;	/* Count of parity errors on channel */
+	u64		ch_err_frame;	/* Count of framing errors on channel */
+	u64		ch_err_break;	/* Count of breaks on channel */
+	u64		ch_err_overrun; /* Count of overruns on channel */
+
+	u64		ch_xon_sends;	/* Count of xons transmitted */
+	u64		ch_xoff_sends;	/* Count of xoffs transmitted */
+};
+
+/************************************************************************
+ * Per channel/port Classic UART structures				*
+ ************************************************************************
+ *		Base Structure Entries Usage Meanings to Host		*
+ *									*
+ *	W = read write		R = read only				*
+ *			U = Unused.					*
+ ************************************************************************/
+
+struct cls_uart_struct {
+	u8 txrx;	/* WR  RHR/THR - Holding Reg */
+	u8 ier;		/* WR  IER - Interrupt Enable Reg */
+	u8 isr_fcr;	/* WR  ISR/FCR - Interrupt Status Reg/Fifo Control Reg*/
+	u8 lcr;		/* WR  LCR - Line Control Reg */
+	u8 mcr;		/* WR  MCR - Modem Control Reg */
+	u8 lsr;		/* WR  LSR - Line Status Reg */
+	u8 msr;		/* WR  MSR - Modem Status Reg */
+	u8 spr;		/* WR  SPR - Scratch Pad Reg */
+};
+
+/* Where to read the interrupt register (8bits) */
+#define UART_CLASSIC_POLL_ADDR_OFFSET	0x40
+
+#define UART_EXAR654_ENHANCED_REGISTER_SET 0xBF
+
+#define UART_16654_FCR_TXTRIGGER_8	0x0
+#define UART_16654_FCR_TXTRIGGER_16	0x10
+#define UART_16654_FCR_TXTRIGGER_32	0x20
+#define UART_16654_FCR_TXTRIGGER_56	0x30
+
+#define UART_16654_FCR_RXTRIGGER_8	0x0
+#define UART_16654_FCR_RXTRIGGER_16	0x40
+#define UART_16654_FCR_RXTRIGGER_56	0x80
+#define UART_16654_FCR_RXTRIGGER_60	0xC0
+
+#define UART_IIR_CTSRTS			0x20	/* Received CTS/RTS change of state */
+#define UART_IIR_RDI_TIMEOUT		0x0C    /* Receiver data TIMEOUT */
+
+/*
+ * These are the EXTENDED definitions for the Exar 654's Interrupt
+ * Enable Register.
+ */
+#define UART_EXAR654_EFR_ECB      0x10    /* Enhanced control bit */
+#define UART_EXAR654_EFR_IXON     0x2     /* Receiver compares Xon1/Xoff1 */
+#define UART_EXAR654_EFR_IXOFF    0x8     /* Transmit Xon1/Xoff1 */
+#define UART_EXAR654_EFR_RTSDTR   0x40    /* Auto RTS/DTR Flow Control Enable */
+#define UART_EXAR654_EFR_CTSDSR   0x80    /* Auto CTS/DSR Flow COntrol Enable */
+
+#define UART_EXAR654_XOFF_DETECT  0x1     /* Indicates whether chip saw an incoming XOFF char  */
+#define UART_EXAR654_XON_DETECT   0x2     /* Indicates whether chip saw an incoming XON char */
+
+#define UART_EXAR654_IER_XOFF     0x20    /* Xoff Interrupt Enable */
+#define UART_EXAR654_IER_RTSDTR   0x40    /* Output Interrupt Enable */
+#define UART_EXAR654_IER_CTSDSR   0x80    /* Input Interrupt Enable */
+
+/************************************************************************
+ * Per channel/port NEO UART structure					*
+ ************************************************************************
+ *		Base Structure Entries Usage Meanings to Host		*
+ *									*
+ *	W = read write		R = read only				*
+ *			U = Unused.					*
+ ************************************************************************/
+
+struct neo_uart_struct {
+	 u8 txrx;		/* WR	RHR/THR - Holding Reg */
+	 u8 ier;		/* WR	IER - Interrupt Enable Reg */
+	 u8 isr_fcr;		/* WR	ISR/FCR - Interrupt Status Reg/Fifo Control Reg */
+	 u8 lcr;		/* WR	LCR - Line Control Reg */
+	 u8 mcr;		/* WR	MCR - Modem Control Reg */
+	 u8 lsr;		/* WR	LSR - Line Status Reg */
+	 u8 msr;		/* WR	MSR - Modem Status Reg */
+	 u8 spr;		/* WR	SPR - Scratch Pad Reg */
+	 u8 fctr;		/* WR	FCTR - Feature Control Reg */
+	 u8 efr;		/* WR	EFR - Enhanced Function Reg */
+	 u8 tfifo;		/* WR	TXCNT/TXTRG - Transmit FIFO Reg */
+	 u8 rfifo;		/* WR	RXCNT/RXTRG - Receive FIFO Reg */
+	 u8 xoffchar1;	/* WR	XOFF 1 - XOff Character 1 Reg */
+	 u8 xoffchar2;	/* WR	XOFF 2 - XOff Character 2 Reg */
+	 u8 xonchar1;	/* WR	XON 1 - Xon Character 1 Reg */
+	 u8 xonchar2;	/* WR	XON 2 - XOn Character 2 Reg */
+
+	 u8 reserved1[0x2ff - 0x200]; /* U	Reserved by Exar */
+	 u8 txrxburst[64];	/* RW	64 bytes of RX/TX FIFO Data */
+	 u8 reserved2[0x37f - 0x340]; /* U	Reserved by Exar */
+	 u8 rxburst_with_errors[64];	/* R	64 bytes of RX FIFO Data + LSR */
+};
+
+/* Where to read the extended interrupt register (32bits instead of 8bits) */
+#define	UART_17158_POLL_ADDR_OFFSET	0x80
+
+/*
+ * These are the redefinitions for the FCTR on the XR17C158, since
+ * Exar made them different than their earlier design. (XR16C854)
+ */
+
+/* These are only applicable when table D is selected */
+#define UART_17158_FCTR_RTS_NODELAY	0x00
+#define UART_17158_FCTR_RTS_4DELAY	0x01
+#define UART_17158_FCTR_RTS_6DELAY	0x02
+#define UART_17158_FCTR_RTS_8DELAY	0x03
+#define UART_17158_FCTR_RTS_12DELAY	0x12
+#define UART_17158_FCTR_RTS_16DELAY	0x05
+#define UART_17158_FCTR_RTS_20DELAY	0x13
+#define UART_17158_FCTR_RTS_24DELAY	0x06
+#define UART_17158_FCTR_RTS_28DELAY	0x14
+#define UART_17158_FCTR_RTS_32DELAY	0x07
+#define UART_17158_FCTR_RTS_36DELAY	0x16
+#define UART_17158_FCTR_RTS_40DELAY	0x08
+#define UART_17158_FCTR_RTS_44DELAY	0x09
+#define UART_17158_FCTR_RTS_48DELAY	0x10
+#define UART_17158_FCTR_RTS_52DELAY	0x11
+
+#define UART_17158_FCTR_RTS_IRDA	0x10
+#define UART_17158_FCTR_RS485		0x20
+#define UART_17158_FCTR_TRGA		0x00
+#define UART_17158_FCTR_TRGB		0x40
+#define UART_17158_FCTR_TRGC		0x80
+#define UART_17158_FCTR_TRGD		0xC0
+
+/* 17158 trigger table selects.. */
+#define UART_17158_FCTR_BIT6		0x40
+#define UART_17158_FCTR_BIT7		0x80
+
+/* 17158 TX/RX memmapped buffer offsets */
+#define UART_17158_RX_FIFOSIZE		64
+#define UART_17158_TX_FIFOSIZE		64
+
+/* 17158 Extended IIR's */
+#define UART_17158_IIR_RDI_TIMEOUT	0x0C	/* Receiver data TIMEOUT */
+#define UART_17158_IIR_XONXOFF		0x10	/* Received an XON/XOFF char */
+#define UART_17158_IIR_HWFLOW_STATE_CHANGE 0x20	/* CTS/DSR or RTS/DTR state change */
+#define UART_17158_IIR_FIFO_ENABLED	0xC0	/* 16550 FIFOs are Enabled */
+
+/*
+ * These are the extended interrupts that get sent
+ * back to us from the UART's 32bit interrupt register
+ */
+#define UART_17158_RX_LINE_STATUS	0x1	/* RX Ready */
+#define UART_17158_RXRDY_TIMEOUT	0x2	/* RX Ready Timeout */
+#define UART_17158_TXRDY		0x3	/* TX Ready */
+#define UART_17158_MSR			0x4	/* Modem State Change */
+#define UART_17158_TX_AND_FIFO_CLR	0x40	/* Transmitter Holding Reg Empty */
+#define UART_17158_RX_FIFO_DATA_ERROR	0x80	/* UART detected an RX FIFO Data error */
+
+/*
+ * These are the EXTENDED definitions for the 17C158's Interrupt
+ * Enable Register.
+ */
+#define UART_17158_EFR_ECB	0x10	/* Enhanced control bit */
+#define UART_17158_EFR_IXON	0x2	/* Receiver compares Xon1/Xoff1 */
+#define UART_17158_EFR_IXOFF	0x8	/* Transmit Xon1/Xoff1 */
+#define UART_17158_EFR_RTSDTR	0x40	/* Auto RTS/DTR Flow Control Enable */
+#define UART_17158_EFR_CTSDSR	0x80	/* Auto CTS/DSR Flow COntrol Enable */
+
+#define UART_17158_XOFF_DETECT	0x1	/* Indicates whether chip saw an incoming XOFF char */
+#define UART_17158_XON_DETECT	0x2	/* Indicates whether chip saw an incoming XON char */
+
+#define UART_17158_IER_RSVD1	0x10	/* Reserved by Exar */
+#define UART_17158_IER_XOFF	0x20	/* Xoff Interrupt Enable */
+#define UART_17158_IER_RTSDTR	0x40	/* Output Interrupt Enable */
+#define UART_17158_IER_CTSDSR	0x80	/* Input Interrupt Enable */
+
+#define PCI_DEVICE_NEO_2DB9_PCI_NAME		"Neo 2 - DB9 Universal PCI"
+#define PCI_DEVICE_NEO_2DB9PRI_PCI_NAME		"Neo 2 - DB9 Universal PCI - Powered Ring Indicator"
+#define PCI_DEVICE_NEO_2RJ45_PCI_NAME		"Neo 2 - RJ45 Universal PCI"
+#define PCI_DEVICE_NEO_2RJ45PRI_PCI_NAME	"Neo 2 - RJ45 Universal PCI - Powered Ring Indicator"
+#define PCIE_DEVICE_NEO_IBM_PCI_NAME		"Neo 4 - PCI Express - IBM"
+
+/*
+ * Our Global Variables.
+ */
+extern struct	uart_driver jsm_uart_driver;
+extern struct	board_ops jsm_neo_ops;
+extern struct	board_ops jsm_cls_ops;
+extern int	jsm_debug;
+
+/*************************************************************************
+ *
+ * Prototypes for non-static functions used in more than one module
+ *
+ *************************************************************************/
+int jsm_tty_init(struct jsm_board *);
+int jsm_uart_port_init(struct jsm_board *);
+int jsm_remove_uart_port(struct jsm_board *);
+void jsm_input(struct jsm_channel *ch);
+void jsm_check_queue_flow_control(struct jsm_channel *ch);
+
+#endif
diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c
new file mode 100644
index 000000000..3fd57ac3a
--- /dev/null
+++ b/drivers/tty/serial/jsm/jsm_cls.c
@@ -0,0 +1,949 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2003 Digi International (www.digi.com)
+ *	Scott H Kilau <Scott_Kilau at digi dot com>
+ *
+ *	NOTE TO LINUX KERNEL HACKERS:  DO NOT REFORMAT THIS CODE!
+ *
+ *	This is shared code between Digi's CVS archive and the
+ *	Linux Kernel sources.
+ *	Changing the source just for reformatting needlessly breaks
+ *	our CVS diff history.
+ *
+ *	Send any bug fixes/changes to:  Eng.Linux at digi dot com.
+ *	Thank you.
+ *
+ */
+
+#include <linux/delay.h>	/* For udelay */
+#include <linux/io.h>		/* For read[bwl]/write[bwl] */
+#include <linux/serial.h>	/* For struct async_serial */
+#include <linux/serial_reg.h>	/* For the various UART offsets */
+#include <linux/pci.h>
+#include <linux/tty.h>
+
+#include "jsm.h"	/* Driver main header file */
+
+static struct {
+	unsigned int rate;
+	unsigned int cflag;
+} baud_rates[] = {
+	{ 921600, B921600 },
+	{ 460800, B460800 },
+	{ 230400, B230400 },
+	{ 115200, B115200 },
+	{  57600, B57600  },
+	{  38400, B38400  },
+	{  19200, B19200  },
+	{   9600, B9600   },
+	{   4800, B4800   },
+	{   2400, B2400   },
+	{   1200, B1200   },
+	{    600, B600    },
+	{    300, B300    },
+	{    200, B200    },
+	{    150, B150    },
+	{    134, B134    },
+	{    110, B110    },
+	{     75, B75     },
+	{     50, B50     },
+};
+
+static void cls_set_cts_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on CTS flow control, turn off IXON flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_CTSDSR);
+	isr_fcr &= ~(UART_EXAR654_EFR_IXON);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/*
+	 * Enable interrupts for CTS flow, turn off interrupts for
+	 * received XOFF chars
+	 */
+	ier |= (UART_EXAR654_IER_CTSDSR);
+	ier &= ~(UART_EXAR654_IER_XOFF);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_t_tlevel = 16;
+}
+
+static void cls_set_ixon_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on IXON flow control, turn off CTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXON);
+	isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Now set our current start/stop chars while in enhanced mode */
+	writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
+	writeb(0, &ch->ch_cls_uart->lsr);
+	writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
+	writeb(0, &ch->ch_cls_uart->spr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/*
+	 * Disable interrupts for CTS flow, turn on interrupts for
+	 * received XOFF chars
+	 */
+	ier &= ~(UART_EXAR654_IER_CTSDSR);
+	ier |= (UART_EXAR654_IER_XOFF);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+}
+
+static void cls_set_no_output_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn off IXON flow control, turn off CTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB);
+	isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR | UART_EXAR654_EFR_IXON);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/*
+	 * Disable interrupts for CTS flow, turn off interrupts for
+	 * received XOFF chars
+	 */
+	ier &= ~(UART_EXAR654_IER_CTSDSR);
+	ier &= ~(UART_EXAR654_IER_XOFF);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_r_watermark = 0;
+	ch->ch_t_tlevel = 16;
+	ch->ch_r_tlevel = 16;
+}
+
+static void cls_set_rts_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on RTS flow control, turn off IXOFF flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_RTSDTR);
+	isr_fcr &= ~(UART_EXAR654_EFR_IXOFF);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Enable interrupts for RTS flow */
+	ier |= (UART_EXAR654_IER_RTSDTR);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_r_watermark = 4;
+	ch->ch_r_tlevel = 8;
+}
+
+static void cls_set_ixoff_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on IXOFF flow control, turn off RTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXOFF);
+	isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Now set our current start/stop chars while in enhanced mode */
+	writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
+	writeb(0, &ch->ch_cls_uart->lsr);
+	writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
+	writeb(0, &ch->ch_cls_uart->spr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Disable interrupts for RTS flow */
+	ier &= ~(UART_EXAR654_IER_RTSDTR);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+}
+
+static void cls_set_no_input_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn off IXOFF flow control, turn off RTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB);
+	isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR | UART_EXAR654_EFR_IXOFF);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Disable interrupts for RTS flow */
+	ier &= ~(UART_EXAR654_IER_RTSDTR);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_t_tlevel = 16;
+	ch->ch_r_tlevel = 16;
+}
+
+/*
+ * cls_clear_break.
+ * Determines whether its time to shut off break condition.
+ *
+ * No locks are assumed to be held when calling this function.
+ * channel lock is held and released in this function.
+ */
+static void cls_clear_break(struct jsm_channel *ch)
+{
+	unsigned long lock_flags;
+
+	spin_lock_irqsave(&ch->ch_lock, lock_flags);
+
+	/* Turn break off, and unset some variables */
+	if (ch->ch_flags & CH_BREAK_SENDING) {
+		u8 temp = readb(&ch->ch_cls_uart->lcr);
+
+		writeb((temp & ~UART_LCR_SBC), &ch->ch_cls_uart->lcr);
+
+		ch->ch_flags &= ~(CH_BREAK_SENDING);
+		jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+			"clear break Finishing UART_LCR_SBC! finished: %lx\n",
+			jiffies);
+	}
+	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+}
+
+static void cls_disable_receiver(struct jsm_channel *ch)
+{
+	u8 tmp = readb(&ch->ch_cls_uart->ier);
+
+	tmp &= ~(UART_IER_RDI);
+	writeb(tmp, &ch->ch_cls_uart->ier);
+}
+
+static void cls_enable_receiver(struct jsm_channel *ch)
+{
+	u8 tmp = readb(&ch->ch_cls_uart->ier);
+
+	tmp |= (UART_IER_RDI);
+	writeb(tmp, &ch->ch_cls_uart->ier);
+}
+
+/* Make the UART raise any of the output signals we want up */
+static void cls_assert_modem_signals(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	writeb(ch->ch_mostat, &ch->ch_cls_uart->mcr);
+}
+
+static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
+{
+	int qleft = 0;
+	u8 linestatus;
+	u8 error_mask = 0;
+	u16 head;
+	u16 tail;
+	unsigned long flags;
+
+	if (!ch)
+		return;
+
+	spin_lock_irqsave(&ch->ch_lock, flags);
+
+	/* cache head and tail of queue */
+	head = ch->ch_r_head & RQUEUEMASK;
+	tail = ch->ch_r_tail & RQUEUEMASK;
+
+	ch->ch_cached_lsr = 0;
+
+	/* Store how much space we have left in the queue */
+	qleft = tail - head - 1;
+	if (qleft < 0)
+		qleft += RQUEUEMASK + 1;
+
+	/*
+	 * Create a mask to determine whether we should
+	 * insert the character (if any) into our queue.
+	 */
+	if (ch->ch_c_iflag & IGNBRK)
+		error_mask |= UART_LSR_BI;
+
+	while (1) {
+		/*
+		 * Grab the linestatus register, we need to
+		 * check to see if there is any data to read
+		 */
+		linestatus = readb(&ch->ch_cls_uart->lsr);
+
+		/* Break out if there is no data to fetch */
+		if (!(linestatus & UART_LSR_DR))
+			break;
+
+		/*
+		 * Discard character if we are ignoring the error mask
+		 * which in this case is the break signal.
+		 */
+		if (linestatus & error_mask)  {
+			linestatus = 0;
+			readb(&ch->ch_cls_uart->txrx);
+			continue;
+		}
+
+		/*
+		 * If our queue is full, we have no choice but to drop some
+		 * data. The assumption is that HWFLOW or SWFLOW should have
+		 * stopped things way way before we got to this point.
+		 *
+		 * I decided that I wanted to ditch the oldest data first,
+		 * I hope thats okay with everyone? Yes? Good.
+		 */
+		while (qleft < 1) {
+			tail = (tail + 1) & RQUEUEMASK;
+			ch->ch_r_tail = tail;
+			ch->ch_err_overrun++;
+			qleft++;
+		}
+
+		ch->ch_equeue[head] = linestatus & (UART_LSR_BI | UART_LSR_PE
+								 | UART_LSR_FE);
+		ch->ch_rqueue[head] = readb(&ch->ch_cls_uart->txrx);
+
+		qleft--;
+
+		if (ch->ch_equeue[head] & UART_LSR_PE)
+			ch->ch_err_parity++;
+		if (ch->ch_equeue[head] & UART_LSR_BI)
+			ch->ch_err_break++;
+		if (ch->ch_equeue[head] & UART_LSR_FE)
+			ch->ch_err_frame++;
+
+		/* Add to, and flip head if needed */
+		head = (head + 1) & RQUEUEMASK;
+		ch->ch_rxcount++;
+	}
+
+	/*
+	 * Write new final heads to channel structure.
+	 */
+	ch->ch_r_head = head & RQUEUEMASK;
+	ch->ch_e_head = head & EQUEUEMASK;
+
+	spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+static void cls_copy_data_from_queue_to_uart(struct jsm_channel *ch)
+{
+	u16 tail;
+	int n;
+	int qlen;
+	u32 len_written = 0;
+	struct circ_buf *circ;
+
+	if (!ch)
+		return;
+
+	circ = &ch->uart_port.state->xmit;
+
+	/* No data to write to the UART */
+	if (uart_circ_empty(circ))
+		return;
+
+	/* If port is "stopped", don't send any data to the UART */
+	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
+		return;
+
+	/* We have to do it this way, because of the EXAR TXFIFO count bug. */
+	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
+		return;
+
+	n = 32;
+
+	/* cache tail of queue */
+	tail = circ->tail & (UART_XMIT_SIZE - 1);
+	qlen = uart_circ_chars_pending(circ);
+
+	/* Find minimum of the FIFO space, versus queue length */
+	n = min(n, qlen);
+
+	while (n > 0) {
+		writeb(circ->buf[tail], &ch->ch_cls_uart->txrx);
+		tail = (tail + 1) & (UART_XMIT_SIZE - 1);
+		n--;
+		ch->ch_txcount++;
+		len_written++;
+	}
+
+	/* Update the final tail */
+	circ->tail = tail & (UART_XMIT_SIZE - 1);
+
+	if (len_written > ch->ch_t_tlevel)
+		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+
+	if (uart_circ_empty(circ))
+		uart_write_wakeup(&ch->uart_port);
+}
+
+static void cls_parse_modem(struct jsm_channel *ch, u8 signals)
+{
+	u8 msignals = signals;
+
+	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
+		"neo_parse_modem: port: %d msignals: %x\n",
+		ch->ch_portnum, msignals);
+
+	/*
+	 * Scrub off lower bits.
+	 * They signify delta's, which I don't care about
+	 * Keep DDCD and DDSR though
+	 */
+	msignals &= 0xf8;
+
+	if (msignals & UART_MSR_DDCD)
+		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
+	if (msignals & UART_MSR_DDSR)
+		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_CTS);
+
+	if (msignals & UART_MSR_DCD)
+		ch->ch_mistat |= UART_MSR_DCD;
+	else
+		ch->ch_mistat &= ~UART_MSR_DCD;
+
+	if (msignals & UART_MSR_DSR)
+		ch->ch_mistat |= UART_MSR_DSR;
+	else
+		ch->ch_mistat &= ~UART_MSR_DSR;
+
+	if (msignals & UART_MSR_RI)
+		ch->ch_mistat |= UART_MSR_RI;
+	else
+		ch->ch_mistat &= ~UART_MSR_RI;
+
+	if (msignals & UART_MSR_CTS)
+		ch->ch_mistat |= UART_MSR_CTS;
+	else
+		ch->ch_mistat &= ~UART_MSR_CTS;
+
+	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
+		"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
+		ch->ch_portnum,
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
+}
+
+/* Parse the ISR register for the specific port */
+static inline void cls_parse_isr(struct jsm_board *brd, uint port)
+{
+	struct jsm_channel *ch;
+	u8 isr = 0;
+	unsigned long flags;
+
+	/*
+	 * No need to verify board pointer, it was already
+	 * verified in the interrupt routine.
+	 */
+
+	if (port >= brd->nasync)
+		return;
+
+	ch = brd->channels[port];
+	if (!ch)
+		return;
+
+	/* Here we try to figure out what caused the interrupt to happen */
+	while (1) {
+		isr = readb(&ch->ch_cls_uart->isr_fcr);
+
+		/* Bail if no pending interrupt on port */
+		if (isr & UART_IIR_NO_INT)
+			break;
+
+		/* Receive Interrupt pending */
+		if (isr & (UART_IIR_RDI | UART_IIR_RDI_TIMEOUT)) {
+			/* Read data from uart -> queue */
+			cls_copy_data_from_uart_to_queue(ch);
+			jsm_check_queue_flow_control(ch);
+		}
+
+		/* Transmit Hold register empty pending */
+		if (isr & UART_IIR_THRI) {
+			/* Transfer data (if any) from Write Queue -> UART. */
+			spin_lock_irqsave(&ch->ch_lock, flags);
+			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+			spin_unlock_irqrestore(&ch->ch_lock, flags);
+			cls_copy_data_from_queue_to_uart(ch);
+		}
+
+		/*
+		 * CTS/RTS change of state:
+		 * Don't need to do anything, the cls_parse_modem
+		 * below will grab the updated modem signals.
+		 */
+
+		/* Parse any modem signal changes */
+		cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
+	}
+}
+
+/* Channel lock MUST be held before calling this function! */
+static void cls_flush_uart_write(struct jsm_channel *ch)
+{
+	u8 tmp = 0;
+	u8 i = 0;
+
+	if (!ch)
+		return;
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT),
+						&ch->ch_cls_uart->isr_fcr);
+
+	for (i = 0; i < 10; i++) {
+		/* Check to see if the UART feels it completely flushed FIFO */
+		tmp = readb(&ch->ch_cls_uart->isr_fcr);
+		if (tmp & UART_FCR_CLEAR_XMIT) {
+			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+				"Still flushing TX UART... i: %d\n", i);
+			udelay(10);
+		} else
+			break;
+	}
+
+	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+}
+
+/* Channel lock MUST be held before calling this function! */
+static void cls_flush_uart_read(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	/*
+	 * For complete POSIX compatibility, we should be purging the
+	 * read FIFO in the UART here.
+	 *
+	 * However, clearing the read FIFO (UART_FCR_CLEAR_RCVR) also
+	 * incorrectly flushes write data as well as just basically trashing the
+	 * FIFO.
+	 *
+	 * Presumably, this is a bug in this UART.
+	 */
+
+	udelay(10);
+}
+
+static void cls_send_start_character(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	if (ch->ch_startc != __DISABLED_CHAR) {
+		ch->ch_xon_sends++;
+		writeb(ch->ch_startc, &ch->ch_cls_uart->txrx);
+	}
+}
+
+static void cls_send_stop_character(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	if (ch->ch_stopc != __DISABLED_CHAR) {
+		ch->ch_xoff_sends++;
+		writeb(ch->ch_stopc, &ch->ch_cls_uart->txrx);
+	}
+}
+
+/*
+ * cls_param()
+ * Send any/all changes to the line to the UART.
+ */
+static void cls_param(struct jsm_channel *ch)
+{
+	u8 lcr = 0;
+	u8 uart_lcr = 0;
+	u8 ier = 0;
+	u32 baud = 9600;
+	int quot = 0;
+	struct jsm_board *bd;
+	int i;
+	unsigned int cflag;
+
+	bd = ch->ch_bd;
+	if (!bd)
+		return;
+
+	/*
+	 * If baud rate is zero, flush queues, and set mval to drop DTR.
+	 */
+	if ((ch->ch_c_cflag & CBAUD) == B0) {
+		ch->ch_r_head = 0;
+		ch->ch_r_tail = 0;
+		ch->ch_e_head = 0;
+		ch->ch_e_tail = 0;
+
+		cls_flush_uart_write(ch);
+		cls_flush_uart_read(ch);
+
+		/* The baudrate is B0 so all modem lines are to be dropped. */
+		ch->ch_flags |= (CH_BAUD0);
+		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
+		cls_assert_modem_signals(ch);
+		return;
+	}
+
+	cflag = C_BAUD(ch->uart_port.state->port.tty);
+	baud = 9600;
+	for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
+		if (baud_rates[i].cflag == cflag) {
+			baud = baud_rates[i].rate;
+			break;
+		}
+	}
+
+	if (ch->ch_flags & CH_BAUD0)
+		ch->ch_flags &= ~(CH_BAUD0);
+
+	if (ch->ch_c_cflag & PARENB)
+		lcr |= UART_LCR_PARITY;
+
+	if (!(ch->ch_c_cflag & PARODD))
+		lcr |= UART_LCR_EPAR;
+
+	if (ch->ch_c_cflag & CMSPAR)
+		lcr |= UART_LCR_SPAR;
+
+	if (ch->ch_c_cflag & CSTOPB)
+		lcr |= UART_LCR_STOP;
+
+	lcr |= UART_LCR_WLEN(tty_get_char_size(ch->ch_c_cflag));
+
+	ier = readb(&ch->ch_cls_uart->ier);
+	uart_lcr = readb(&ch->ch_cls_uart->lcr);
+
+	quot = ch->ch_bd->bd_dividend / baud;
+
+	if (quot != 0) {
+		writeb(UART_LCR_DLAB, &ch->ch_cls_uart->lcr);
+		writeb((quot & 0xff), &ch->ch_cls_uart->txrx);
+		writeb((quot >> 8), &ch->ch_cls_uart->ier);
+		writeb(lcr, &ch->ch_cls_uart->lcr);
+	}
+
+	if (uart_lcr != lcr)
+		writeb(lcr, &ch->ch_cls_uart->lcr);
+
+	if (ch->ch_c_cflag & CREAD)
+		ier |= (UART_IER_RDI | UART_IER_RLSI);
+
+	ier |= (UART_IER_THRI | UART_IER_MSI);
+
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	if (ch->ch_c_cflag & CRTSCTS)
+		cls_set_cts_flow_control(ch);
+	else if (ch->ch_c_iflag & IXON) {
+		/*
+		 * If start/stop is set to disable,
+		 * then we should disable flow control.
+		 */
+		if ((ch->ch_startc == __DISABLED_CHAR) ||
+			(ch->ch_stopc == __DISABLED_CHAR))
+			cls_set_no_output_flow_control(ch);
+		else
+			cls_set_ixon_flow_control(ch);
+	} else
+		cls_set_no_output_flow_control(ch);
+
+	if (ch->ch_c_cflag & CRTSCTS)
+		cls_set_rts_flow_control(ch);
+	else if (ch->ch_c_iflag & IXOFF) {
+		/*
+		 * If start/stop is set to disable,
+		 * then we should disable flow control.
+		 */
+		if ((ch->ch_startc == __DISABLED_CHAR) ||
+			(ch->ch_stopc == __DISABLED_CHAR))
+			cls_set_no_input_flow_control(ch);
+		else
+			cls_set_ixoff_flow_control(ch);
+	} else
+		cls_set_no_input_flow_control(ch);
+
+	cls_assert_modem_signals(ch);
+
+	/* get current status of the modem signals now */
+	cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
+}
+
+/*
+ * cls_intr()
+ *
+ * Classic specific interrupt handler.
+ */
+static irqreturn_t cls_intr(int irq, void *voidbrd)
+{
+	struct jsm_board *brd = voidbrd;
+	unsigned long lock_flags;
+	unsigned char uart_poll;
+	uint i = 0;
+
+	/* Lock out the slow poller from running on this board. */
+	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
+
+	/*
+	 * Check the board's global interrupt offset to see if we
+	 * acctually do have an interrupt pending on us.
+	 */
+	uart_poll = readb(brd->re_map_membase + UART_CLASSIC_POLL_ADDR_OFFSET);
+
+	jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
+		__FILE__, __LINE__, uart_poll);
+
+	if (!uart_poll) {
+		jsm_dbg(INTR, &brd->pci_dev,
+			"Kernel interrupted to me, but no pending interrupts...\n");
+		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
+		return IRQ_NONE;
+	}
+
+	/* At this point, we have at least SOMETHING to service, dig further. */
+
+	/* Parse each port to find out what caused the interrupt */
+	for (i = 0; i < brd->nasync; i++)
+		cls_parse_isr(brd, i);
+
+	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
+
+	return IRQ_HANDLED;
+}
+
+/* Inits UART */
+static void cls_uart_init(struct jsm_channel *ch)
+{
+	unsigned char lcrb = readb(&ch->ch_cls_uart->lcr);
+	unsigned char isr_fcr = 0;
+
+	writeb(0, &ch->ch_cls_uart->ier);
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on Enhanced/Extended controls */
+	isr_fcr |= (UART_EXAR654_EFR_ECB);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Clear out UART and FIFO */
+	readb(&ch->ch_cls_uart->txrx);
+
+	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT),
+						 &ch->ch_cls_uart->isr_fcr);
+	udelay(10);
+
+	ch->ch_flags |= (CH_FIFO_ENABLED | CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+
+	readb(&ch->ch_cls_uart->lsr);
+	readb(&ch->ch_cls_uart->msr);
+}
+
+/*
+ * Turns off UART.
+ */
+static void cls_uart_off(struct jsm_channel *ch)
+{
+	/* Stop all interrupts from accurring. */
+	writeb(0, &ch->ch_cls_uart->ier);
+}
+
+/*
+ * cls_get_uarts_bytes_left.
+ * Returns 0 is nothing left in the FIFO, returns 1 otherwise.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static u32 cls_get_uart_bytes_left(struct jsm_channel *ch)
+{
+	u8 left = 0;
+	u8 lsr = readb(&ch->ch_cls_uart->lsr);
+
+	/* Determine whether the Transmitter is empty or not */
+	if (!(lsr & UART_LSR_TEMT))
+		left = 1;
+	else {
+		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+		left = 0;
+	}
+
+	return left;
+}
+
+/*
+ * cls_send_break.
+ * Starts sending a break thru the UART.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static void cls_send_break(struct jsm_channel *ch)
+{
+	/* Tell the UART to start sending the break */
+	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
+		u8 temp = readb(&ch->ch_cls_uart->lcr);
+
+		writeb((temp | UART_LCR_SBC), &ch->ch_cls_uart->lcr);
+		ch->ch_flags |= (CH_BREAK_SENDING);
+	}
+}
+
+/*
+ * cls_send_immediate_char.
+ * Sends a specific character as soon as possible to the UART,
+ * jumping over any bytes that might be in the write queue.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static void cls_send_immediate_char(struct jsm_channel *ch, unsigned char c)
+{
+	writeb(c, &ch->ch_cls_uart->txrx);
+}
+
+struct board_ops jsm_cls_ops = {
+	.intr =				cls_intr,
+	.uart_init =			cls_uart_init,
+	.uart_off =			cls_uart_off,
+	.param =			cls_param,
+	.assert_modem_signals =		cls_assert_modem_signals,
+	.flush_uart_write =		cls_flush_uart_write,
+	.flush_uart_read =		cls_flush_uart_read,
+	.disable_receiver =		cls_disable_receiver,
+	.enable_receiver =		cls_enable_receiver,
+	.send_break =			cls_send_break,
+	.clear_break =			cls_clear_break,
+	.send_start_character =		cls_send_start_character,
+	.send_stop_character =		cls_send_stop_character,
+	.copy_data_from_queue_to_uart = cls_copy_data_from_queue_to_uart,
+	.get_uart_bytes_left =		cls_get_uart_bytes_left,
+	.send_immediate_char =		cls_send_immediate_char
+};
+
diff --git a/drivers/tty/serial/jsm/jsm_driver.c b/drivers/tty/serial/jsm/jsm_driver.c
new file mode 100644
index 000000000..417a5b6bf
--- /dev/null
+++ b/drivers/tty/serial/jsm/jsm_driver.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0+
+/************************************************************************
+ * Copyright 2003 Digi International (www.digi.com)
+ *
+ * Copyright (C) 2004 IBM Corporation. All rights reserved.
+ *
+ * Contact Information:
+ * Scott H Kilau <Scott_Kilau@digi.com>
+ * Wendy Xiong   <wendyx@us.ibm.com>
+ *
+ *
+ ***********************************************************************/
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "jsm.h"
+
+MODULE_AUTHOR("Digi International, https://www.digi.com");
+MODULE_DESCRIPTION("Driver for the Digi International Neo and Classic PCI based product line");
+MODULE_LICENSE("GPL");
+
+#define JSM_DRIVER_NAME "jsm"
+#define NR_PORTS	32
+#define JSM_MINOR_START	0
+
+struct uart_driver jsm_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= JSM_DRIVER_NAME,
+	.dev_name	= "ttyn",
+	.major		= 0,
+	.minor		= JSM_MINOR_START,
+	.nr		= NR_PORTS,
+};
+
+static pci_ers_result_t jsm_io_error_detected(struct pci_dev *pdev,
+					pci_channel_state_t state);
+static pci_ers_result_t jsm_io_slot_reset(struct pci_dev *pdev);
+static void jsm_io_resume(struct pci_dev *pdev);
+
+static const struct pci_error_handlers jsm_err_handler = {
+	.error_detected = jsm_io_error_detected,
+	.slot_reset = jsm_io_slot_reset,
+	.resume = jsm_io_resume,
+};
+
+int jsm_debug;
+module_param(jsm_debug, int, 0);
+MODULE_PARM_DESC(jsm_debug, "Driver debugging level");
+
+static int jsm_probe_one(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	int rc = 0;
+	struct jsm_board *brd;
+	static int adapter_count;
+
+	rc = pci_enable_device(pdev);
+	if (rc) {
+		dev_err(&pdev->dev, "Device enable FAILED\n");
+		goto out;
+	}
+
+	rc = pci_request_regions(pdev, JSM_DRIVER_NAME);
+	if (rc) {
+		dev_err(&pdev->dev, "pci_request_region FAILED\n");
+		goto out_disable_device;
+	}
+
+	brd = kzalloc(sizeof(*brd), GFP_KERNEL);
+	if (!brd) {
+		rc = -ENOMEM;
+		goto out_release_regions;
+	}
+
+	/* store the info for the board we've found */
+	brd->boardnum = adapter_count++;
+	brd->pci_dev = pdev;
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_NEO_2DB9:
+	case PCI_DEVICE_ID_NEO_2DB9PRI:
+	case PCI_DEVICE_ID_NEO_2RJ45:
+	case PCI_DEVICE_ID_NEO_2RJ45PRI:
+	case PCI_DEVICE_ID_NEO_2_422_485:
+		brd->maxports = 2;
+		break;
+
+	case PCI_DEVICE_ID_CLASSIC_4:
+	case PCI_DEVICE_ID_CLASSIC_4_422:
+	case PCI_DEVICE_ID_NEO_4:
+	case PCIE_DEVICE_ID_NEO_4:
+	case PCIE_DEVICE_ID_NEO_4RJ45:
+	case PCIE_DEVICE_ID_NEO_4_IBM:
+		brd->maxports = 4;
+		break;
+
+	case PCI_DEVICE_ID_CLASSIC_8:
+	case PCI_DEVICE_ID_CLASSIC_8_422:
+	case PCI_DEVICE_ID_DIGI_NEO_8:
+	case PCIE_DEVICE_ID_NEO_8:
+	case PCIE_DEVICE_ID_NEO_8RJ45:
+		brd->maxports = 8;
+		break;
+
+	default:
+		brd->maxports = 1;
+		break;
+	}
+
+	spin_lock_init(&brd->bd_intr_lock);
+
+	/* store which revision we have */
+	brd->rev = pdev->revision;
+
+	brd->irq = pdev->irq;
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_CLASSIC_4:
+	case PCI_DEVICE_ID_CLASSIC_4_422:
+	case PCI_DEVICE_ID_CLASSIC_8:
+	case PCI_DEVICE_ID_CLASSIC_8_422:
+
+		jsm_dbg(INIT, &brd->pci_dev,
+			"jsm_found_board - Classic adapter\n");
+
+		/*
+		 * For PCI ClassicBoards
+		 * PCI Local Address (.i.e. "resource" number) space
+		 * 0	PLX Memory Mapped Config
+		 * 1	PLX I/O Mapped Config
+		 * 2	I/O Mapped UARTs and Status
+		 * 3	Memory Mapped VPD
+		 * 4	Memory Mapped UARTs and Status
+		 */
+
+		/* Get the PCI Base Address Registers */
+		brd->membase = pci_resource_start(pdev, 4);
+		brd->membase_end = pci_resource_end(pdev, 4);
+
+		if (brd->membase & 0x1)
+			brd->membase &= ~0x3;
+		else
+			brd->membase &= ~0xF;
+
+		brd->iobase = pci_resource_start(pdev, 1);
+		brd->iobase_end = pci_resource_end(pdev, 1);
+		brd->iobase = ((unsigned int)(brd->iobase)) & 0xFFFE;
+
+		/* Assign the board_ops struct */
+		brd->bd_ops = &jsm_cls_ops;
+
+		brd->bd_uart_offset = 0x8;
+		brd->bd_dividend = 921600;
+
+		brd->re_map_membase = ioremap(brd->membase,
+						pci_resource_len(pdev, 4));
+		if (!brd->re_map_membase) {
+			dev_err(&pdev->dev,
+				"Card has no PCI Memory resources, failing board.\n");
+			rc = -ENOMEM;
+			goto out_kfree_brd;
+		}
+
+		/*
+		 * Enable Local Interrupt 1			(0x1),
+		 * Local Interrupt 1 Polarity Active high	(0x2),
+		 * Enable PCI interrupt				(0x43)
+		 */
+		outb(0x43, brd->iobase + 0x4c);
+
+		break;
+
+	case PCI_DEVICE_ID_NEO_2DB9:
+	case PCI_DEVICE_ID_NEO_2DB9PRI:
+	case PCI_DEVICE_ID_NEO_2RJ45:
+	case PCI_DEVICE_ID_NEO_2RJ45PRI:
+	case PCI_DEVICE_ID_NEO_2_422_485:
+	case PCI_DEVICE_ID_NEO_4:
+	case PCIE_DEVICE_ID_NEO_4:
+	case PCIE_DEVICE_ID_NEO_4RJ45:
+	case PCIE_DEVICE_ID_NEO_4_IBM:
+	case PCI_DEVICE_ID_DIGI_NEO_8:
+	case PCIE_DEVICE_ID_NEO_8:
+	case PCIE_DEVICE_ID_NEO_8RJ45:
+
+		jsm_dbg(INIT, &brd->pci_dev, "jsm_found_board - NEO adapter\n");
+
+		/* get the PCI Base Address Registers */
+		brd->membase	= pci_resource_start(pdev, 0);
+		brd->membase_end = pci_resource_end(pdev, 0);
+
+		if (brd->membase & 1)
+			brd->membase &= ~0x3;
+		else
+			brd->membase &= ~0xF;
+
+		/* Assign the board_ops struct */
+		brd->bd_ops = &jsm_neo_ops;
+
+		brd->bd_uart_offset = 0x200;
+		brd->bd_dividend = 921600;
+
+		brd->re_map_membase = ioremap(brd->membase,
+						pci_resource_len(pdev, 0));
+		if (!brd->re_map_membase) {
+			dev_err(&pdev->dev,
+				"Card has no PCI Memory resources, failing board.\n");
+			rc = -ENOMEM;
+			goto out_kfree_brd;
+		}
+
+		break;
+	default:
+		rc = -ENXIO;
+		goto out_kfree_brd;
+	}
+
+	rc = request_irq(brd->irq, brd->bd_ops->intr, IRQF_SHARED, "JSM", brd);
+	if (rc) {
+		dev_warn(&pdev->dev, "Failed to hook IRQ %d\n", brd->irq);
+		goto out_iounmap;
+	}
+
+	rc = jsm_tty_init(brd);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Can't init tty devices (%d)\n", rc);
+		rc = -ENXIO;
+		goto out_free_irq;
+	}
+
+	rc = jsm_uart_port_init(brd);
+	if (rc < 0) {
+		/* XXX: leaking all resources from jsm_tty_init here! */
+		dev_err(&pdev->dev, "Can't init uart port (%d)\n", rc);
+		rc = -ENXIO;
+		goto out_free_irq;
+	}
+
+	/* Log the information about the board */
+	dev_info(&pdev->dev, "board %d: Digi Classic/Neo (rev %d), irq %d\n",
+			adapter_count, brd->rev, brd->irq);
+
+	pci_set_drvdata(pdev, brd);
+	pci_save_state(pdev);
+
+	return 0;
+ out_free_irq:
+	jsm_remove_uart_port(brd);
+	free_irq(brd->irq, brd);
+ out_iounmap:
+	iounmap(brd->re_map_membase);
+ out_kfree_brd:
+	kfree(brd);
+ out_release_regions:
+	pci_release_regions(pdev);
+ out_disable_device:
+	pci_disable_device(pdev);
+ out:
+	return rc;
+}
+
+static void jsm_remove_one(struct pci_dev *pdev)
+{
+	struct jsm_board *brd = pci_get_drvdata(pdev);
+	int i = 0;
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_CLASSIC_4:
+	case PCI_DEVICE_ID_CLASSIC_4_422:
+	case PCI_DEVICE_ID_CLASSIC_8:
+	case PCI_DEVICE_ID_CLASSIC_8_422:
+		/* Tell card not to interrupt anymore. */
+		outb(0x0, brd->iobase + 0x4c);
+		break;
+	default:
+		break;
+	}
+
+	jsm_remove_uart_port(brd);
+
+	free_irq(brd->irq, brd);
+	iounmap(brd->re_map_membase);
+
+	/* Free all allocated channels structs */
+	for (i = 0; i < brd->maxports; i++) {
+		if (brd->channels[i]) {
+			kfree(brd->channels[i]->ch_rqueue);
+			kfree(brd->channels[i]->ch_equeue);
+			kfree(brd->channels[i]);
+		}
+	}
+
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	kfree(brd);
+}
+
+static const struct pci_device_id jsm_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_2DB9), 0, 0, 0 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_2DB9PRI), 0, 0, 1 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_2RJ45), 0, 0, 2 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_2RJ45PRI), 0, 0, 3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_4_IBM), 0, 0, 4 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_DIGI_NEO_8), 0, 0, 5 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_4), 0, 0, 6 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_1_422), 0, 0, 7 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_1_422_485), 0, 0, 8 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_NEO_2_422_485), 0, 0, 9 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_8), 0, 0, 10 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_4), 0, 0, 11 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_4RJ45), 0, 0, 12 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_8RJ45), 0, 0, 13 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_CLASSIC_4), 0, 0, 14 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_CLASSIC_4_422), 0, 0, 15 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_CLASSIC_8), 0, 0, 16 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_DIGI, PCI_DEVICE_ID_CLASSIC_8_422), 0, 0, 17 },
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, jsm_pci_tbl);
+
+static struct pci_driver jsm_driver = {
+	.name		= JSM_DRIVER_NAME,
+	.id_table	= jsm_pci_tbl,
+	.probe		= jsm_probe_one,
+	.remove		= jsm_remove_one,
+	.err_handler    = &jsm_err_handler,
+};
+
+static pci_ers_result_t jsm_io_error_detected(struct pci_dev *pdev,
+					pci_channel_state_t state)
+{
+	struct jsm_board *brd = pci_get_drvdata(pdev);
+
+	jsm_remove_uart_port(brd);
+
+	return PCI_ERS_RESULT_NEED_RESET;
+}
+
+static pci_ers_result_t jsm_io_slot_reset(struct pci_dev *pdev)
+{
+	int rc;
+
+	rc = pci_enable_device(pdev);
+
+	if (rc)
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	pci_set_master(pdev);
+
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void jsm_io_resume(struct pci_dev *pdev)
+{
+	struct jsm_board *brd = pci_get_drvdata(pdev);
+
+	pci_restore_state(pdev);
+	pci_save_state(pdev);
+
+	jsm_uart_port_init(brd);
+}
+
+static int __init jsm_init_module(void)
+{
+	int rc;
+
+	rc = uart_register_driver(&jsm_uart_driver);
+	if (!rc) {
+		rc = pci_register_driver(&jsm_driver);
+		if (rc)
+			uart_unregister_driver(&jsm_uart_driver);
+	}
+	return rc;
+}
+
+static void __exit jsm_exit_module(void)
+{
+	pci_unregister_driver(&jsm_driver);
+	uart_unregister_driver(&jsm_uart_driver);
+}
+
+module_init(jsm_init_module);
+module_exit(jsm_exit_module);
diff --git a/drivers/tty/serial/jsm/jsm_neo.c b/drivers/tty/serial/jsm/jsm_neo.c
new file mode 100644
index 000000000..0c78f6627
--- /dev/null
+++ b/drivers/tty/serial/jsm/jsm_neo.c
@@ -0,0 +1,1387 @@
+// SPDX-License-Identifier: GPL-2.0+
+/************************************************************************
+ * Copyright 2003 Digi International (www.digi.com)
+ *
+ * Copyright (C) 2004 IBM Corporation. All rights reserved.
+ *
+ * Contact Information:
+ * Scott H Kilau <Scott_Kilau@digi.com>
+ * Wendy Xiong   <wendyx@us.ibm.com>
+ *
+ ***********************************************************************/
+#include <linux/delay.h>	/* For udelay */
+#include <linux/serial_reg.h>	/* For the various UART offsets */
+#include <linux/tty.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+
+#include "jsm.h"		/* Driver main header file */
+
+static u32 jsm_offset_table[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
+
+/*
+ * This function allows calls to ensure that all outstanding
+ * PCI writes have been completed, by doing a PCI read against
+ * a non-destructive, read-only location on the Neo card.
+ *
+ * In this case, we are reading the DVID (Read-only Device Identification)
+ * value of the Neo card.
+ */
+static inline void neo_pci_posting_flush(struct jsm_board *bd)
+{
+      readb(bd->re_map_membase + 0x8D);
+}
+
+static void neo_set_cts_flow_control(struct jsm_channel *ch)
+{
+	u8 ier, efr;
+	ier = readb(&ch->ch_neo_uart->ier);
+	efr = readb(&ch->ch_neo_uart->efr);
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting CTSFLOW\n");
+
+	/* Turn on auto CTS flow control */
+	ier |= (UART_17158_IER_CTSDSR);
+	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_CTSDSR);
+
+	/* Turn off auto Xon flow control */
+	efr &= ~(UART_17158_EFR_IXON);
+
+	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Turn on UART enhanced bits */
+	writeb(efr, &ch->ch_neo_uart->efr);
+
+	/* Turn on table D, with 8 char hi/low watermarks */
+	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
+
+	/* Feed the UART our trigger levels */
+	writeb(8, &ch->ch_neo_uart->tfifo);
+	ch->ch_t_tlevel = 8;
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+}
+
+static void neo_set_rts_flow_control(struct jsm_channel *ch)
+{
+	u8 ier, efr;
+	ier = readb(&ch->ch_neo_uart->ier);
+	efr = readb(&ch->ch_neo_uart->efr);
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting RTSFLOW\n");
+
+	/* Turn on auto RTS flow control */
+	ier |= (UART_17158_IER_RTSDTR);
+	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_RTSDTR);
+
+	/* Turn off auto Xoff flow control */
+	ier &= ~(UART_17158_IER_XOFF);
+	efr &= ~(UART_17158_EFR_IXOFF);
+
+	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Turn on UART enhanced bits */
+	writeb(efr, &ch->ch_neo_uart->efr);
+
+	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
+	ch->ch_r_watermark = 4;
+
+	writeb(56, &ch->ch_neo_uart->rfifo);
+	ch->ch_r_tlevel = 56;
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+
+	/*
+	 * From the Neo UART spec sheet:
+	 * The auto RTS/DTR function must be started by asserting
+	 * RTS/DTR# output pin (MCR bit-0 or 1 to logic 1 after
+	 * it is enabled.
+	 */
+	ch->ch_mostat |= (UART_MCR_RTS);
+}
+
+
+static void neo_set_ixon_flow_control(struct jsm_channel *ch)
+{
+	u8 ier, efr;
+	ier = readb(&ch->ch_neo_uart->ier);
+	efr = readb(&ch->ch_neo_uart->efr);
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting IXON FLOW\n");
+
+	/* Turn off auto CTS flow control */
+	ier &= ~(UART_17158_IER_CTSDSR);
+	efr &= ~(UART_17158_EFR_CTSDSR);
+
+	/* Turn on auto Xon flow control */
+	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXON);
+
+	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Turn on UART enhanced bits */
+	writeb(efr, &ch->ch_neo_uart->efr);
+
+	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
+	ch->ch_r_watermark = 4;
+
+	writeb(32, &ch->ch_neo_uart->rfifo);
+	ch->ch_r_tlevel = 32;
+
+	/* Tell UART what start/stop chars it should be looking for */
+	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
+	writeb(0, &ch->ch_neo_uart->xonchar2);
+
+	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
+	writeb(0, &ch->ch_neo_uart->xoffchar2);
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+}
+
+static void neo_set_ixoff_flow_control(struct jsm_channel *ch)
+{
+	u8 ier, efr;
+	ier = readb(&ch->ch_neo_uart->ier);
+	efr = readb(&ch->ch_neo_uart->efr);
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting IXOFF FLOW\n");
+
+	/* Turn off auto RTS flow control */
+	ier &= ~(UART_17158_IER_RTSDTR);
+	efr &= ~(UART_17158_EFR_RTSDTR);
+
+	/* Turn on auto Xoff flow control */
+	ier |= (UART_17158_IER_XOFF);
+	efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
+
+	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Turn on UART enhanced bits */
+	writeb(efr, &ch->ch_neo_uart->efr);
+
+	/* Turn on table D, with 8 char hi/low watermarks */
+	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
+
+	writeb(8, &ch->ch_neo_uart->tfifo);
+	ch->ch_t_tlevel = 8;
+
+	/* Tell UART what start/stop chars it should be looking for */
+	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
+	writeb(0, &ch->ch_neo_uart->xonchar2);
+
+	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
+	writeb(0, &ch->ch_neo_uart->xoffchar2);
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+}
+
+static void neo_set_no_input_flow_control(struct jsm_channel *ch)
+{
+	u8 ier, efr;
+	ier = readb(&ch->ch_neo_uart->ier);
+	efr = readb(&ch->ch_neo_uart->efr);
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Unsetting Input FLOW\n");
+
+	/* Turn off auto RTS flow control */
+	ier &= ~(UART_17158_IER_RTSDTR);
+	efr &= ~(UART_17158_EFR_RTSDTR);
+
+	/* Turn off auto Xoff flow control */
+	ier &= ~(UART_17158_IER_XOFF);
+	if (ch->ch_c_iflag & IXON)
+		efr &= ~(UART_17158_EFR_IXOFF);
+	else
+		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
+
+	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Turn on UART enhanced bits */
+	writeb(efr, &ch->ch_neo_uart->efr);
+
+	/* Turn on table D, with 8 char hi/low watermarks */
+	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
+
+	ch->ch_r_watermark = 0;
+
+	writeb(16, &ch->ch_neo_uart->tfifo);
+	ch->ch_t_tlevel = 16;
+
+	writeb(16, &ch->ch_neo_uart->rfifo);
+	ch->ch_r_tlevel = 16;
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+}
+
+static void neo_set_no_output_flow_control(struct jsm_channel *ch)
+{
+	u8 ier, efr;
+	ier = readb(&ch->ch_neo_uart->ier);
+	efr = readb(&ch->ch_neo_uart->efr);
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Unsetting Output FLOW\n");
+
+	/* Turn off auto CTS flow control */
+	ier &= ~(UART_17158_IER_CTSDSR);
+	efr &= ~(UART_17158_EFR_CTSDSR);
+
+	/* Turn off auto Xon flow control */
+	if (ch->ch_c_iflag & IXOFF)
+		efr &= ~(UART_17158_EFR_IXON);
+	else
+		efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXON);
+
+	/* Why? Becuz Exar's spec says we have to zero it out before setting it */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Turn on UART enhanced bits */
+	writeb(efr, &ch->ch_neo_uart->efr);
+
+	/* Turn on table D, with 8 char hi/low watermarks */
+	writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
+
+	ch->ch_r_watermark = 0;
+
+	writeb(16, &ch->ch_neo_uart->tfifo);
+	ch->ch_t_tlevel = 16;
+
+	writeb(16, &ch->ch_neo_uart->rfifo);
+	ch->ch_r_tlevel = 16;
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+}
+
+static inline void neo_set_new_start_stop_chars(struct jsm_channel *ch)
+{
+
+	/* if hardware flow control is set, then skip this whole thing */
+	if (ch->ch_c_cflag & CRTSCTS)
+		return;
+
+	jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "start\n");
+
+	/* Tell UART what start/stop chars it should be looking for */
+	writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
+	writeb(0, &ch->ch_neo_uart->xonchar2);
+
+	writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
+	writeb(0, &ch->ch_neo_uart->xoffchar2);
+}
+
+static void neo_copy_data_from_uart_to_queue(struct jsm_channel *ch)
+{
+	int qleft = 0;
+	u8 linestatus = 0;
+	u8 error_mask = 0;
+	int n = 0;
+	int total = 0;
+	u16 head;
+	u16 tail;
+
+	/* cache head and tail of queue */
+	head = ch->ch_r_head & RQUEUEMASK;
+	tail = ch->ch_r_tail & RQUEUEMASK;
+
+	/* Get our cached LSR */
+	linestatus = ch->ch_cached_lsr;
+	ch->ch_cached_lsr = 0;
+
+	/* Store how much space we have left in the queue */
+	qleft = tail - head - 1;
+	if (qleft < 0)
+		qleft += RQUEUEMASK + 1;
+
+	/*
+	 * If the UART is not in FIFO mode, force the FIFO copy to
+	 * NOT be run, by setting total to 0.
+	 *
+	 * On the other hand, if the UART IS in FIFO mode, then ask
+	 * the UART to give us an approximation of data it has RX'ed.
+	 */
+	if (!(ch->ch_flags & CH_FIFO_ENABLED))
+		total = 0;
+	else {
+		total = readb(&ch->ch_neo_uart->rfifo);
+
+		/*
+		 * EXAR chip bug - RX FIFO COUNT - Fudge factor.
+		 *
+		 * This resolves a problem/bug with the Exar chip that sometimes
+		 * returns a bogus value in the rfifo register.
+		 * The count can be any where from 0-3 bytes "off".
+		 * Bizarre, but true.
+		 */
+		total -= 3;
+	}
+
+	/*
+	 * Finally, bound the copy to make sure we don't overflow
+	 * our own queue...
+	 * The byte by byte copy loop below this loop this will
+	 * deal with the queue overflow possibility.
+	 */
+	total = min(total, qleft);
+
+	while (total > 0) {
+		/*
+		 * Grab the linestatus register, we need to check
+		 * to see if there are any errors in the FIFO.
+		 */
+		linestatus = readb(&ch->ch_neo_uart->lsr);
+
+		/*
+		 * Break out if there is a FIFO error somewhere.
+		 * This will allow us to go byte by byte down below,
+		 * finding the exact location of the error.
+		 */
+		if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
+			break;
+
+		/* Make sure we don't go over the end of our queue */
+		n = min(((u32) total), (RQUEUESIZE - (u32) head));
+
+		/*
+		 * Cut down n even further if needed, this is to fix
+		 * a problem with memcpy_fromio() with the Neo on the
+		 * IBM pSeries platform.
+		 * 15 bytes max appears to be the magic number.
+		 */
+		n = min((u32) n, (u32) 12);
+
+		/*
+		 * Since we are grabbing the linestatus register, which
+		 * will reset some bits after our read, we need to ensure
+		 * we don't miss our TX FIFO emptys.
+		 */
+		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
+			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+
+		linestatus = 0;
+
+		/* Copy data from uart to the queue */
+		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
+		/*
+		 * Since RX_FIFO_DATA_ERROR was 0, we are guaranteed
+		 * that all the data currently in the FIFO is free of
+		 * breaks and parity/frame/orun errors.
+		 */
+		memset(ch->ch_equeue + head, 0, n);
+
+		/* Add to and flip head if needed */
+		head = (head + n) & RQUEUEMASK;
+		total -= n;
+		qleft -= n;
+		ch->ch_rxcount += n;
+	}
+
+	/*
+	 * Create a mask to determine whether we should
+	 * insert the character (if any) into our queue.
+	 */
+	if (ch->ch_c_iflag & IGNBRK)
+		error_mask |= UART_LSR_BI;
+
+	/*
+	 * Now cleanup any leftover bytes still in the UART.
+	 * Also deal with any possible queue overflow here as well.
+	 */
+	while (1) {
+
+		/*
+		 * Its possible we have a linestatus from the loop above
+		 * this, so we "OR" on any extra bits.
+		 */
+		linestatus |= readb(&ch->ch_neo_uart->lsr);
+
+		/*
+		 * If the chip tells us there is no more data pending to
+		 * be read, we can then leave.
+		 * But before we do, cache the linestatus, just in case.
+		 */
+		if (!(linestatus & UART_LSR_DR)) {
+			ch->ch_cached_lsr = linestatus;
+			break;
+		}
+
+		/* No need to store this bit */
+		linestatus &= ~UART_LSR_DR;
+
+		/*
+		 * Since we are grabbing the linestatus register, which
+		 * will reset some bits after our read, we need to ensure
+		 * we don't miss our TX FIFO emptys.
+		 */
+		if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
+			linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
+			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+		}
+
+		/*
+		 * Discard character if we are ignoring the error mask.
+		 */
+		if (linestatus & error_mask) {
+			u8 discard;
+			linestatus = 0;
+			memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
+			continue;
+		}
+
+		/*
+		 * If our queue is full, we have no choice but to drop some data.
+		 * The assumption is that HWFLOW or SWFLOW should have stopped
+		 * things way way before we got to this point.
+		 *
+		 * I decided that I wanted to ditch the oldest data first,
+		 * I hope thats okay with everyone? Yes? Good.
+		 */
+		while (qleft < 1) {
+			jsm_dbg(READ, &ch->ch_bd->pci_dev,
+				"Queue full, dropping DATA:%x LSR:%x\n",
+				ch->ch_rqueue[tail], ch->ch_equeue[tail]);
+
+			ch->ch_r_tail = tail = (tail + 1) & RQUEUEMASK;
+			ch->ch_err_overrun++;
+			qleft++;
+		}
+
+		memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
+		ch->ch_equeue[head] = (u8) linestatus;
+
+		jsm_dbg(READ, &ch->ch_bd->pci_dev, "DATA/LSR pair: %x %x\n",
+			ch->ch_rqueue[head], ch->ch_equeue[head]);
+
+		/* Ditch any remaining linestatus value. */
+		linestatus = 0;
+
+		/* Add to and flip head if needed */
+		head = (head + 1) & RQUEUEMASK;
+
+		qleft--;
+		ch->ch_rxcount++;
+	}
+
+	/*
+	 * Write new final heads to channel structure.
+	 */
+	ch->ch_r_head = head & RQUEUEMASK;
+	ch->ch_e_head = head & EQUEUEMASK;
+	jsm_input(ch);
+}
+
+static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
+{
+	u16 head;
+	u16 tail;
+	int n;
+	int s;
+	int qlen;
+	u32 len_written = 0;
+	struct circ_buf *circ;
+
+	if (!ch)
+		return;
+
+	circ = &ch->uart_port.state->xmit;
+
+	/* No data to write to the UART */
+	if (uart_circ_empty(circ))
+		return;
+
+	/* If port is "stopped", don't send any data to the UART */
+	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
+		return;
+	/*
+	 * If FIFOs are disabled. Send data directly to txrx register
+	 */
+	if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
+		u8 lsrbits = readb(&ch->ch_neo_uart->lsr);
+
+		ch->ch_cached_lsr |= lsrbits;
+		if (ch->ch_cached_lsr & UART_LSR_THRE) {
+			ch->ch_cached_lsr &= ~(UART_LSR_THRE);
+
+			writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
+			jsm_dbg(WRITE, &ch->ch_bd->pci_dev,
+				"Tx data: %x\n", circ->buf[circ->tail]);
+			circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
+			ch->ch_txcount++;
+		}
+		return;
+	}
+
+	/*
+	 * We have to do it this way, because of the EXAR TXFIFO count bug.
+	 */
+	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
+		return;
+
+	n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
+
+	/* cache head and tail of queue */
+	head = circ->head & (UART_XMIT_SIZE - 1);
+	tail = circ->tail & (UART_XMIT_SIZE - 1);
+	qlen = uart_circ_chars_pending(circ);
+
+	/* Find minimum of the FIFO space, versus queue length */
+	n = min(n, qlen);
+
+	while (n > 0) {
+
+		s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
+		s = min(s, n);
+
+		if (s <= 0)
+			break;
+
+		memcpy_toio(&ch->ch_neo_uart->txrxburst, circ->buf + tail, s);
+		/* Add and flip queue if needed */
+		tail = (tail + s) & (UART_XMIT_SIZE - 1);
+		n -= s;
+		ch->ch_txcount += s;
+		len_written += s;
+	}
+
+	/* Update the final tail */
+	circ->tail = tail & (UART_XMIT_SIZE - 1);
+
+	if (len_written >= ch->ch_t_tlevel)
+		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+
+	if (uart_circ_empty(circ))
+		uart_write_wakeup(&ch->uart_port);
+}
+
+static void neo_parse_modem(struct jsm_channel *ch, u8 signals)
+{
+	u8 msignals = signals;
+
+	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
+		"neo_parse_modem: port: %d msignals: %x\n",
+		ch->ch_portnum, msignals);
+
+	/* Scrub off lower bits. They signify delta's, which I don't care about */
+	/* Keep DDCD and DDSR though */
+	msignals &= 0xf8;
+
+	if (msignals & UART_MSR_DDCD)
+		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
+	if (msignals & UART_MSR_DDSR)
+		uart_handle_cts_change(&ch->uart_port, msignals & UART_MSR_CTS);
+	if (msignals & UART_MSR_DCD)
+		ch->ch_mistat |= UART_MSR_DCD;
+	else
+		ch->ch_mistat &= ~UART_MSR_DCD;
+
+	if (msignals & UART_MSR_DSR)
+		ch->ch_mistat |= UART_MSR_DSR;
+	else
+		ch->ch_mistat &= ~UART_MSR_DSR;
+
+	if (msignals & UART_MSR_RI)
+		ch->ch_mistat |= UART_MSR_RI;
+	else
+		ch->ch_mistat &= ~UART_MSR_RI;
+
+	if (msignals & UART_MSR_CTS)
+		ch->ch_mistat |= UART_MSR_CTS;
+	else
+		ch->ch_mistat &= ~UART_MSR_CTS;
+
+	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
+		"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
+		ch->ch_portnum,
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
+}
+
+/* Make the UART raise any of the output signals we want up */
+static void neo_assert_modem_signals(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
+
+	/* flush write operation */
+	neo_pci_posting_flush(ch->ch_bd);
+}
+
+/*
+ * Flush the WRITE FIFO on the Neo.
+ *
+ * NOTE: Channel lock MUST be held before calling this function!
+ */
+static void neo_flush_uart_write(struct jsm_channel *ch)
+{
+	u8 tmp = 0;
+	int i = 0;
+
+	if (!ch)
+		return;
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
+
+	for (i = 0; i < 10; i++) {
+
+		/* Check to see if the UART feels it completely flushed the FIFO. */
+		tmp = readb(&ch->ch_neo_uart->isr_fcr);
+		if (tmp & UART_FCR_CLEAR_XMIT) {
+			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+				"Still flushing TX UART... i: %d\n", i);
+			udelay(10);
+		}
+		else
+			break;
+	}
+
+	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+}
+
+
+/*
+ * Flush the READ FIFO on the Neo.
+ *
+ * NOTE: Channel lock MUST be held before calling this function!
+ */
+static void neo_flush_uart_read(struct jsm_channel *ch)
+{
+	u8 tmp = 0;
+	int i = 0;
+
+	if (!ch)
+		return;
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
+
+	for (i = 0; i < 10; i++) {
+
+		/* Check to see if the UART feels it completely flushed the FIFO. */
+		tmp = readb(&ch->ch_neo_uart->isr_fcr);
+		if (tmp & 2) {
+			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+				"Still flushing RX UART... i: %d\n", i);
+			udelay(10);
+		}
+		else
+			break;
+	}
+}
+
+/*
+ * No locks are assumed to be held when calling this function.
+ */
+static void neo_clear_break(struct jsm_channel *ch)
+{
+	unsigned long lock_flags;
+
+	spin_lock_irqsave(&ch->ch_lock, lock_flags);
+
+	/* Turn break off, and unset some variables */
+	if (ch->ch_flags & CH_BREAK_SENDING) {
+		u8 temp = readb(&ch->ch_neo_uart->lcr);
+		writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
+
+		ch->ch_flags &= ~(CH_BREAK_SENDING);
+		jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+			"clear break Finishing UART_LCR_SBC! finished: %lx\n",
+			jiffies);
+
+		/* flush write operation */
+		neo_pci_posting_flush(ch->ch_bd);
+	}
+	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+}
+
+/*
+ * Parse the ISR register.
+ */
+static void neo_parse_isr(struct jsm_board *brd, u32 port)
+{
+	struct jsm_channel *ch;
+	u8 isr;
+	u8 cause;
+	unsigned long lock_flags;
+
+	if (!brd)
+		return;
+
+	if (port >= brd->maxports)
+		return;
+
+	ch = brd->channels[port];
+	if (!ch)
+		return;
+
+	/* Here we try to figure out what caused the interrupt to happen */
+	while (1) {
+
+		isr = readb(&ch->ch_neo_uart->isr_fcr);
+
+		/* Bail if no pending interrupt */
+		if (isr & UART_IIR_NO_INT)
+			break;
+
+		/*
+		 * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
+		 */
+		isr &= ~(UART_17158_IIR_FIFO_ENABLED);
+
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d isr: %x\n",
+			__FILE__, __LINE__, isr);
+
+		if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
+			/* Read data from uart -> queue */
+			neo_copy_data_from_uart_to_queue(ch);
+
+			/* Call our tty layer to enforce queue flow control if needed. */
+			spin_lock_irqsave(&ch->ch_lock, lock_flags);
+			jsm_check_queue_flow_control(ch);
+			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+		}
+
+		if (isr & UART_IIR_THRI) {
+			/* Transfer data (if any) from Write Queue -> UART. */
+			spin_lock_irqsave(&ch->ch_lock, lock_flags);
+			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+			neo_copy_data_from_queue_to_uart(ch);
+		}
+
+		if (isr & UART_17158_IIR_XONXOFF) {
+			cause = readb(&ch->ch_neo_uart->xoffchar1);
+
+			jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+				"Port %d. Got ISR_XONXOFF: cause:%x\n",
+				port, cause);
+
+			/*
+			 * Since the UART detected either an XON or
+			 * XOFF match, we need to figure out which
+			 * one it was, so we can suspend or resume data flow.
+			 */
+			spin_lock_irqsave(&ch->ch_lock, lock_flags);
+			if (cause == UART_17158_XON_DETECT) {
+				/* Is output stopped right now, if so, resume it */
+				if (brd->channels[port]->ch_flags & CH_STOP) {
+					ch->ch_flags &= ~(CH_STOP);
+				}
+				jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+					"Port %d. XON detected in incoming data\n",
+					port);
+			}
+			else if (cause == UART_17158_XOFF_DETECT) {
+				if (!(brd->channels[port]->ch_flags & CH_STOP)) {
+					ch->ch_flags |= CH_STOP;
+					jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+						"Setting CH_STOP\n");
+				}
+				jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+					"Port: %d. XOFF detected in incoming data\n",
+					port);
+			}
+			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+		}
+
+		if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
+			/*
+			 * If we get here, this means the hardware is doing auto flow control.
+			 * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
+			 */
+			cause = readb(&ch->ch_neo_uart->mcr);
+
+			/* Which pin is doing auto flow? RTS or DTR? */
+			spin_lock_irqsave(&ch->ch_lock, lock_flags);
+			if ((cause & 0x4) == 0) {
+				if (cause & UART_MCR_RTS)
+					ch->ch_mostat |= UART_MCR_RTS;
+				else
+					ch->ch_mostat &= ~(UART_MCR_RTS);
+			} else {
+				if (cause & UART_MCR_DTR)
+					ch->ch_mostat |= UART_MCR_DTR;
+				else
+					ch->ch_mostat &= ~(UART_MCR_DTR);
+			}
+			spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+		}
+
+		/* Parse any modem signal changes */
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+			"MOD_STAT: sending to parse_modem_sigs\n");
+		spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
+		neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
+		spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
+	}
+}
+
+static inline void neo_parse_lsr(struct jsm_board *brd, u32 port)
+{
+	struct jsm_channel *ch;
+	int linestatus;
+	unsigned long lock_flags;
+
+	if (!brd)
+		return;
+
+	if (port >= brd->maxports)
+		return;
+
+	ch = brd->channels[port];
+	if (!ch)
+		return;
+
+	linestatus = readb(&ch->ch_neo_uart->lsr);
+
+	jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d port: %d linestatus: %x\n",
+		__FILE__, __LINE__, port, linestatus);
+
+	ch->ch_cached_lsr |= linestatus;
+
+	if (ch->ch_cached_lsr & UART_LSR_DR) {
+		/* Read data from uart -> queue */
+		neo_copy_data_from_uart_to_queue(ch);
+		spin_lock_irqsave(&ch->ch_lock, lock_flags);
+		jsm_check_queue_flow_control(ch);
+		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+	}
+
+	/*
+	 * This is a special flag. It indicates that at least 1
+	 * RX error (parity, framing, or break) has happened.
+	 * Mark this in our struct, which will tell me that I have
+	 *to do the special RX+LSR read for this FIFO load.
+	 */
+	if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+			"%s:%d Port: %d Got an RX error, need to parse LSR\n",
+			__FILE__, __LINE__, port);
+
+	/*
+	 * The next 3 tests should *NOT* happen, as the above test
+	 * should encapsulate all 3... At least, thats what Exar says.
+	 */
+
+	if (linestatus & UART_LSR_PE) {
+		ch->ch_err_parity++;
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. PAR ERR!\n",
+			__FILE__, __LINE__, port);
+	}
+
+	if (linestatus & UART_LSR_FE) {
+		ch->ch_err_frame++;
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. FRM ERR!\n",
+			__FILE__, __LINE__, port);
+	}
+
+	if (linestatus & UART_LSR_BI) {
+		ch->ch_err_break++;
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+			"%s:%d Port: %d. BRK INTR!\n",
+			__FILE__, __LINE__, port);
+	}
+
+	if (linestatus & UART_LSR_OE) {
+		/*
+		 * Rx Oruns. Exar says that an orun will NOT corrupt
+		 * the FIFO. It will just replace the holding register
+		 * with this new data byte. So basically just ignore this.
+		 * Probably we should eventually have an orun stat in our driver...
+		 */
+		ch->ch_err_overrun++;
+		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
+			"%s:%d Port: %d. Rx Overrun!\n",
+			__FILE__, __LINE__, port);
+	}
+
+	if (linestatus & UART_LSR_THRE) {
+		spin_lock_irqsave(&ch->ch_lock, lock_flags);
+		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+
+		/* Transfer data (if any) from Write Queue -> UART. */
+		neo_copy_data_from_queue_to_uart(ch);
+	}
+	else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
+		spin_lock_irqsave(&ch->ch_lock, lock_flags);
+		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+
+		/* Transfer data (if any) from Write Queue -> UART. */
+		neo_copy_data_from_queue_to_uart(ch);
+	}
+}
+
+/*
+ * neo_param()
+ * Send any/all changes to the line to the UART.
+ */
+static void neo_param(struct jsm_channel *ch)
+{
+	u8 lcr = 0;
+	u8 uart_lcr, ier;
+	u32 baud;
+	int quot;
+	struct jsm_board *bd;
+
+	bd = ch->ch_bd;
+	if (!bd)
+		return;
+
+	/*
+	 * If baud rate is zero, flush queues, and set mval to drop DTR.
+	 */
+	if ((ch->ch_c_cflag & CBAUD) == B0) {
+		ch->ch_r_head = ch->ch_r_tail = 0;
+		ch->ch_e_head = ch->ch_e_tail = 0;
+
+		neo_flush_uart_write(ch);
+		neo_flush_uart_read(ch);
+
+		ch->ch_flags |= (CH_BAUD0);
+		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
+		neo_assert_modem_signals(ch);
+		return;
+
+	} else {
+		int i;
+		unsigned int cflag;
+		static struct {
+			unsigned int rate;
+			unsigned int cflag;
+		} baud_rates[] = {
+			{ 921600, B921600 },
+			{ 460800, B460800 },
+			{ 230400, B230400 },
+			{ 115200, B115200 },
+			{  57600, B57600  },
+			{  38400, B38400  },
+			{  19200, B19200  },
+			{   9600, B9600   },
+			{   4800, B4800   },
+			{   2400, B2400   },
+			{   1200, B1200   },
+			{    600, B600    },
+			{    300, B300    },
+			{    200, B200    },
+			{    150, B150    },
+			{    134, B134    },
+			{    110, B110    },
+			{     75, B75     },
+			{     50, B50     },
+		};
+
+		cflag = C_BAUD(ch->uart_port.state->port.tty);
+		baud = 9600;
+		for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
+			if (baud_rates[i].cflag == cflag) {
+				baud = baud_rates[i].rate;
+				break;
+			}
+		}
+
+		if (ch->ch_flags & CH_BAUD0)
+			ch->ch_flags &= ~(CH_BAUD0);
+	}
+
+	if (ch->ch_c_cflag & PARENB)
+		lcr |= UART_LCR_PARITY;
+
+	if (!(ch->ch_c_cflag & PARODD))
+		lcr |= UART_LCR_EPAR;
+
+	if (ch->ch_c_cflag & CMSPAR)
+		lcr |= UART_LCR_SPAR;
+
+	if (ch->ch_c_cflag & CSTOPB)
+		lcr |= UART_LCR_STOP;
+
+	lcr |= UART_LCR_WLEN(tty_get_char_size(ch->ch_c_cflag));
+
+	ier = readb(&ch->ch_neo_uart->ier);
+	uart_lcr = readb(&ch->ch_neo_uart->lcr);
+
+	quot = ch->ch_bd->bd_dividend / baud;
+
+	if (quot != 0) {
+		writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
+		writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
+		writeb((quot >> 8), &ch->ch_neo_uart->ier);
+		writeb(lcr, &ch->ch_neo_uart->lcr);
+	}
+
+	if (uart_lcr != lcr)
+		writeb(lcr, &ch->ch_neo_uart->lcr);
+
+	if (ch->ch_c_cflag & CREAD)
+		ier |= (UART_IER_RDI | UART_IER_RLSI);
+
+	ier |= (UART_IER_THRI | UART_IER_MSI);
+
+	writeb(ier, &ch->ch_neo_uart->ier);
+
+	/* Set new start/stop chars */
+	neo_set_new_start_stop_chars(ch);
+
+	if (ch->ch_c_cflag & CRTSCTS)
+		neo_set_cts_flow_control(ch);
+	else if (ch->ch_c_iflag & IXON) {
+		/* If start/stop is set to disable, then we should disable flow control */
+		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
+			neo_set_no_output_flow_control(ch);
+		else
+			neo_set_ixon_flow_control(ch);
+	}
+	else
+		neo_set_no_output_flow_control(ch);
+
+	if (ch->ch_c_cflag & CRTSCTS)
+		neo_set_rts_flow_control(ch);
+	else if (ch->ch_c_iflag & IXOFF) {
+		/* If start/stop is set to disable, then we should disable flow control */
+		if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
+			neo_set_no_input_flow_control(ch);
+		else
+			neo_set_ixoff_flow_control(ch);
+	}
+	else
+		neo_set_no_input_flow_control(ch);
+	/*
+	 * Adjust the RX FIFO Trigger level if baud is less than 9600.
+	 * Not exactly elegant, but this is needed because of the Exar chip's
+	 * delay on firing off the RX FIFO interrupt on slower baud rates.
+	 */
+	if (baud < 9600) {
+		writeb(1, &ch->ch_neo_uart->rfifo);
+		ch->ch_r_tlevel = 1;
+	}
+
+	neo_assert_modem_signals(ch);
+
+	/* Get current status of the modem signals now */
+	neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
+	return;
+}
+
+/*
+ * jsm_neo_intr()
+ *
+ * Neo specific interrupt handler.
+ */
+static irqreturn_t neo_intr(int irq, void *voidbrd)
+{
+	struct jsm_board *brd = voidbrd;
+	struct jsm_channel *ch;
+	int port = 0;
+	int type = 0;
+	int current_port;
+	u32 tmp;
+	u32 uart_poll;
+	unsigned long lock_flags;
+	unsigned long lock_flags2;
+	int outofloop_count = 0;
+
+	/* Lock out the slow poller from running on this board. */
+	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
+
+	/*
+	 * Read in "extended" IRQ information from the 32bit Neo register.
+	 * Bits 0-7: What port triggered the interrupt.
+	 * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
+	 */
+	uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
+
+	jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
+		__FILE__, __LINE__, uart_poll);
+
+	if (!uart_poll) {
+		jsm_dbg(INTR, &brd->pci_dev,
+			"Kernel interrupted to me, but no pending interrupts...\n");
+		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
+		return IRQ_NONE;
+	}
+
+	/* At this point, we have at least SOMETHING to service, dig further... */
+
+	current_port = 0;
+
+	/* Loop on each port */
+	while (((uart_poll & 0xff) != 0) && (outofloop_count < 0xff)){
+
+		tmp = uart_poll;
+		outofloop_count++;
+
+		/* Check current port to see if it has interrupt pending */
+		if ((tmp & jsm_offset_table[current_port]) != 0) {
+			port = current_port;
+			type = tmp >> (8 + (port * 3));
+			type &= 0x7;
+		} else {
+			current_port++;
+			continue;
+		}
+
+		jsm_dbg(INTR, &brd->pci_dev, "%s:%d port: %x type: %x\n",
+			__FILE__, __LINE__, port, type);
+
+		/* Remove this port + type from uart_poll */
+		uart_poll &= ~(jsm_offset_table[port]);
+
+		if (!type) {
+			/* If no type, just ignore it, and move onto next port */
+			jsm_dbg(INTR, &brd->pci_dev,
+				"Interrupt with no type! port: %d\n", port);
+			continue;
+		}
+
+		/* Switch on type of interrupt we have */
+		switch (type) {
+
+		case UART_17158_RXRDY_TIMEOUT:
+			/*
+			 * RXRDY Time-out is cleared by reading data in the
+			* RX FIFO until it falls below the trigger level.
+			 */
+
+			/* Verify the port is in range. */
+			if (port >= brd->nasync)
+				continue;
+
+			ch = brd->channels[port];
+			if (!ch)
+				continue;
+
+			neo_copy_data_from_uart_to_queue(ch);
+
+			/* Call our tty layer to enforce queue flow control if needed. */
+			spin_lock_irqsave(&ch->ch_lock, lock_flags2);
+			jsm_check_queue_flow_control(ch);
+			spin_unlock_irqrestore(&ch->ch_lock, lock_flags2);
+
+			continue;
+
+		case UART_17158_RX_LINE_STATUS:
+			/*
+			 * RXRDY and RX LINE Status (logic OR of LSR[4:1])
+			 */
+			neo_parse_lsr(brd, port);
+			continue;
+
+		case UART_17158_TXRDY:
+			/*
+			 * TXRDY interrupt clears after reading ISR register for the UART channel.
+			 */
+
+			/*
+			 * Yes, this is odd...
+			 * Why would I check EVERY possibility of type of
+			 * interrupt, when we know its TXRDY???
+			 * Becuz for some reason, even tho we got triggered for TXRDY,
+			 * it seems to be occasionally wrong. Instead of TX, which
+			 * it should be, I was getting things like RXDY too. Weird.
+			 */
+			neo_parse_isr(brd, port);
+			continue;
+
+		case UART_17158_MSR:
+			/*
+			 * MSR or flow control was seen.
+			 */
+			neo_parse_isr(brd, port);
+			continue;
+
+		default:
+			/*
+			 * The UART triggered us with a bogus interrupt type.
+			 * It appears the Exar chip, when REALLY bogged down, will throw
+			 * these once and awhile.
+			 * Its harmless, just ignore it and move on.
+			 */
+			jsm_dbg(INTR, &brd->pci_dev,
+				"%s:%d Unknown Interrupt type: %x\n",
+				__FILE__, __LINE__, type);
+			continue;
+		}
+	}
+
+	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
+
+	jsm_dbg(INTR, &brd->pci_dev, "finish\n");
+	return IRQ_HANDLED;
+}
+
+/*
+ * Neo specific way of turning off the receiver.
+ * Used as a way to enforce queue flow control when in
+ * hardware flow control mode.
+ */
+static void neo_disable_receiver(struct jsm_channel *ch)
+{
+	u8 tmp = readb(&ch->ch_neo_uart->ier);
+	tmp &= ~(UART_IER_RDI);
+	writeb(tmp, &ch->ch_neo_uart->ier);
+
+	/* flush write operation */
+	neo_pci_posting_flush(ch->ch_bd);
+}
+
+
+/*
+ * Neo specific way of turning on the receiver.
+ * Used as a way to un-enforce queue flow control when in
+ * hardware flow control mode.
+ */
+static void neo_enable_receiver(struct jsm_channel *ch)
+{
+	u8 tmp = readb(&ch->ch_neo_uart->ier);
+	tmp |= (UART_IER_RDI);
+	writeb(tmp, &ch->ch_neo_uart->ier);
+
+	/* flush write operation */
+	neo_pci_posting_flush(ch->ch_bd);
+}
+
+static void neo_send_start_character(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	if (ch->ch_startc != __DISABLED_CHAR) {
+		ch->ch_xon_sends++;
+		writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
+
+		/* flush write operation */
+		neo_pci_posting_flush(ch->ch_bd);
+	}
+}
+
+static void neo_send_stop_character(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	if (ch->ch_stopc != __DISABLED_CHAR) {
+		ch->ch_xoff_sends++;
+		writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
+
+		/* flush write operation */
+		neo_pci_posting_flush(ch->ch_bd);
+	}
+}
+
+/*
+ * neo_uart_init
+ */
+static void neo_uart_init(struct jsm_channel *ch)
+{
+	writeb(0, &ch->ch_neo_uart->ier);
+	writeb(0, &ch->ch_neo_uart->efr);
+	writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
+
+	/* Clear out UART and FIFO */
+	readb(&ch->ch_neo_uart->txrx);
+	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
+	readb(&ch->ch_neo_uart->lsr);
+	readb(&ch->ch_neo_uart->msr);
+
+	ch->ch_flags |= CH_FIFO_ENABLED;
+
+	/* Assert any signals we want up */
+	writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
+}
+
+/*
+ * Make the UART completely turn off.
+ */
+static void neo_uart_off(struct jsm_channel *ch)
+{
+	/* Turn off UART enhanced bits */
+	writeb(0, &ch->ch_neo_uart->efr);
+
+	/* Stop all interrupts from occurring. */
+	writeb(0, &ch->ch_neo_uart->ier);
+}
+
+static u32 neo_get_uart_bytes_left(struct jsm_channel *ch)
+{
+	u8 left = 0;
+	u8 lsr = readb(&ch->ch_neo_uart->lsr);
+
+	/* We must cache the LSR as some of the bits get reset once read... */
+	ch->ch_cached_lsr |= lsr;
+
+	/* Determine whether the Transmitter is empty or not */
+	if (!(lsr & UART_LSR_TEMT))
+		left = 1;
+	else {
+		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+		left = 0;
+	}
+
+	return left;
+}
+
+/* Channel lock MUST be held by the calling function! */
+static void neo_send_break(struct jsm_channel *ch)
+{
+	/*
+	 * Set the time we should stop sending the break.
+	 * If we are already sending a break, toss away the existing
+	 * time to stop, and use this new value instead.
+	 */
+
+	/* Tell the UART to start sending the break */
+	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
+		u8 temp = readb(&ch->ch_neo_uart->lcr);
+		writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
+		ch->ch_flags |= (CH_BREAK_SENDING);
+
+		/* flush write operation */
+		neo_pci_posting_flush(ch->ch_bd);
+	}
+}
+
+/*
+ * neo_send_immediate_char.
+ *
+ * Sends a specific character as soon as possible to the UART,
+ * jumping over any bytes that might be in the write queue.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static void neo_send_immediate_char(struct jsm_channel *ch, unsigned char c)
+{
+	if (!ch)
+		return;
+
+	writeb(c, &ch->ch_neo_uart->txrx);
+
+	/* flush write operation */
+	neo_pci_posting_flush(ch->ch_bd);
+}
+
+struct board_ops jsm_neo_ops = {
+	.intr				= neo_intr,
+	.uart_init			= neo_uart_init,
+	.uart_off			= neo_uart_off,
+	.param				= neo_param,
+	.assert_modem_signals		= neo_assert_modem_signals,
+	.flush_uart_write		= neo_flush_uart_write,
+	.flush_uart_read		= neo_flush_uart_read,
+	.disable_receiver		= neo_disable_receiver,
+	.enable_receiver		= neo_enable_receiver,
+	.send_break			= neo_send_break,
+	.clear_break			= neo_clear_break,
+	.send_start_character		= neo_send_start_character,
+	.send_stop_character		= neo_send_stop_character,
+	.copy_data_from_queue_to_uart	= neo_copy_data_from_queue_to_uart,
+	.get_uart_bytes_left		= neo_get_uart_bytes_left,
+	.send_immediate_char		= neo_send_immediate_char
+};
diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c
new file mode 100644
index 000000000..222afc270
--- /dev/null
+++ b/drivers/tty/serial/jsm/jsm_tty.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-2.0+
+/************************************************************************
+ * Copyright 2003 Digi International (www.digi.com)
+ *
+ * Copyright (C) 2004 IBM Corporation. All rights reserved.
+ *
+ * Contact Information:
+ * Scott H Kilau <Scott_Kilau@digi.com>
+ * Ananda Venkatarman <mansarov@us.ibm.com>
+ * Modifications:
+ * 01/19/06:	changed jsm_input routine to use the dynamically allocated
+ *		tty_buffer changes. Contributors: Scott Kilau and Ananda V.
+ ***********************************************************************/
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_reg.h>
+#include <linux/delay.h>	/* For udelay */
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "jsm.h"
+
+static DECLARE_BITMAP(linemap, MAXLINES);
+
+static void jsm_carrier(struct jsm_channel *ch);
+
+static inline int jsm_get_mstat(struct jsm_channel *ch)
+{
+	unsigned char mstat;
+	int result;
+
+	jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "start\n");
+
+	mstat = (ch->ch_mostat | ch->ch_mistat);
+
+	result = 0;
+
+	if (mstat & UART_MCR_DTR)
+		result |= TIOCM_DTR;
+	if (mstat & UART_MCR_RTS)
+		result |= TIOCM_RTS;
+	if (mstat & UART_MSR_CTS)
+		result |= TIOCM_CTS;
+	if (mstat & UART_MSR_DSR)
+		result |= TIOCM_DSR;
+	if (mstat & UART_MSR_RI)
+		result |= TIOCM_RI;
+	if (mstat & UART_MSR_DCD)
+		result |= TIOCM_CD;
+
+	jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "finish\n");
+	return result;
+}
+
+static unsigned int jsm_tty_tx_empty(struct uart_port *port)
+{
+	return TIOCSER_TEMT;
+}
+
+/*
+ * Return modem signals to ld.
+ */
+static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
+{
+	int result;
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n");
+
+	result = jsm_get_mstat(channel);
+
+	if (result < 0)
+		return -ENXIO;
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n");
+
+	return result;
+}
+
+/*
+ * jsm_set_modem_info()
+ *
+ * Set modem signals, called by ld.
+ */
+static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n");
+
+	if (mctrl & TIOCM_RTS)
+		channel->ch_mostat |= UART_MCR_RTS;
+	else
+		channel->ch_mostat &= ~UART_MCR_RTS;
+
+	if (mctrl & TIOCM_DTR)
+		channel->ch_mostat |= UART_MCR_DTR;
+	else
+		channel->ch_mostat &= ~UART_MCR_DTR;
+
+	channel->ch_bd->bd_ops->assert_modem_signals(channel);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n");
+	udelay(10);
+}
+
+/*
+ * jsm_tty_write()
+ *
+ * Take data from the user or kernel and send it out to the FEP.
+ * In here exists all the Transparent Print magic as well.
+ */
+static void jsm_tty_write(struct uart_port *port)
+{
+	struct jsm_channel *channel;
+
+	channel = container_of(port, struct jsm_channel, uart_port);
+	channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
+}
+
+static void jsm_tty_start_tx(struct uart_port *port)
+{
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n");
+
+	channel->ch_flags &= ~(CH_STOP);
+	jsm_tty_write(port);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n");
+}
+
+static void jsm_tty_stop_tx(struct uart_port *port)
+{
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n");
+
+	channel->ch_flags |= (CH_STOP);
+
+	jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n");
+}
+
+static void jsm_tty_send_xchar(struct uart_port *port, char ch)
+{
+	unsigned long lock_flags;
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+	struct ktermios *termios;
+
+	spin_lock_irqsave(&port->lock, lock_flags);
+	termios = &port->state->port.tty->termios;
+	if (ch == termios->c_cc[VSTART])
+		channel->ch_bd->bd_ops->send_start_character(channel);
+
+	if (ch == termios->c_cc[VSTOP])
+		channel->ch_bd->bd_ops->send_stop_character(channel);
+	spin_unlock_irqrestore(&port->lock, lock_flags);
+}
+
+static void jsm_tty_stop_rx(struct uart_port *port)
+{
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	channel->ch_bd->bd_ops->disable_receiver(channel);
+}
+
+static void jsm_tty_break(struct uart_port *port, int break_state)
+{
+	unsigned long lock_flags;
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	spin_lock_irqsave(&port->lock, lock_flags);
+	if (break_state == -1)
+		channel->ch_bd->bd_ops->send_break(channel);
+	else
+		channel->ch_bd->bd_ops->clear_break(channel);
+
+	spin_unlock_irqrestore(&port->lock, lock_flags);
+}
+
+static int jsm_tty_open(struct uart_port *port)
+{
+	unsigned long lock_flags;
+	struct jsm_board *brd;
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+	struct ktermios *termios;
+
+	/* Get board pointer from our array of majors we have allocated */
+	brd = channel->ch_bd;
+
+	/*
+	 * Allocate channel buffers for read/write/error.
+	 * Set flag, so we don't get trounced on.
+	 */
+	channel->ch_flags |= (CH_OPENING);
+
+	/* Drop locks, as malloc with GFP_KERNEL can sleep */
+
+	if (!channel->ch_rqueue) {
+		channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
+		if (!channel->ch_rqueue) {
+			jsm_dbg(INIT, &channel->ch_bd->pci_dev,
+				"unable to allocate read queue buf\n");
+			return -ENOMEM;
+		}
+	}
+	if (!channel->ch_equeue) {
+		channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
+		if (!channel->ch_equeue) {
+			jsm_dbg(INIT, &channel->ch_bd->pci_dev,
+				"unable to allocate error queue buf\n");
+			return -ENOMEM;
+		}
+	}
+
+	channel->ch_flags &= ~(CH_OPENING);
+	/*
+	 * Initialize if neither terminal is open.
+	 */
+	jsm_dbg(OPEN, &channel->ch_bd->pci_dev,
+		"jsm_open: initializing channel in open...\n");
+
+	/*
+	 * Flush input queues.
+	 */
+	channel->ch_r_head = channel->ch_r_tail = 0;
+	channel->ch_e_head = channel->ch_e_tail = 0;
+
+	brd->bd_ops->flush_uart_write(channel);
+	brd->bd_ops->flush_uart_read(channel);
+
+	channel->ch_flags = 0;
+	channel->ch_cached_lsr = 0;
+	channel->ch_stops_sent = 0;
+
+	spin_lock_irqsave(&port->lock, lock_flags);
+	termios = &port->state->port.tty->termios;
+	channel->ch_c_cflag	= termios->c_cflag;
+	channel->ch_c_iflag	= termios->c_iflag;
+	channel->ch_c_oflag	= termios->c_oflag;
+	channel->ch_c_lflag	= termios->c_lflag;
+	channel->ch_startc	= termios->c_cc[VSTART];
+	channel->ch_stopc	= termios->c_cc[VSTOP];
+
+	/* Tell UART to init itself */
+	brd->bd_ops->uart_init(channel);
+
+	/*
+	 * Run param in case we changed anything
+	 */
+	brd->bd_ops->param(channel);
+
+	jsm_carrier(channel);
+
+	channel->ch_open_count++;
+	spin_unlock_irqrestore(&port->lock, lock_flags);
+
+	jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n");
+	return 0;
+}
+
+static void jsm_tty_close(struct uart_port *port)
+{
+	struct jsm_board *bd;
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, "start\n");
+
+	bd = channel->ch_bd;
+
+	channel->ch_flags &= ~(CH_STOPI);
+
+	channel->ch_open_count--;
+
+	/*
+	 * If we have HUPCL set, lower DTR and RTS
+	 */
+	if (channel->ch_c_cflag & HUPCL) {
+		jsm_dbg(CLOSE, &channel->ch_bd->pci_dev,
+			"Close. HUPCL set, dropping DTR/RTS\n");
+
+		/* Drop RTS/DTR */
+		channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
+		bd->bd_ops->assert_modem_signals(channel);
+	}
+
+	/* Turn off UART interrupts for this port */
+	channel->ch_bd->bd_ops->uart_off(channel);
+
+	jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, "finish\n");
+}
+
+static void jsm_tty_set_termios(struct uart_port *port,
+				struct ktermios *termios,
+				const struct ktermios *old_termios)
+{
+	unsigned long lock_flags;
+	struct jsm_channel *channel =
+		container_of(port, struct jsm_channel, uart_port);
+
+	spin_lock_irqsave(&port->lock, lock_flags);
+	channel->ch_c_cflag	= termios->c_cflag;
+	channel->ch_c_iflag	= termios->c_iflag;
+	channel->ch_c_oflag	= termios->c_oflag;
+	channel->ch_c_lflag	= termios->c_lflag;
+	channel->ch_startc	= termios->c_cc[VSTART];
+	channel->ch_stopc	= termios->c_cc[VSTOP];
+
+	channel->ch_bd->bd_ops->param(channel);
+	jsm_carrier(channel);
+	spin_unlock_irqrestore(&port->lock, lock_flags);
+}
+
+static const char *jsm_tty_type(struct uart_port *port)
+{
+	return "jsm";
+}
+
+static void jsm_tty_release_port(struct uart_port *port)
+{
+}
+
+static int jsm_tty_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void jsm_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_JSM;
+}
+
+static const struct uart_ops jsm_ops = {
+	.tx_empty	= jsm_tty_tx_empty,
+	.set_mctrl	= jsm_tty_set_mctrl,
+	.get_mctrl	= jsm_tty_get_mctrl,
+	.stop_tx	= jsm_tty_stop_tx,
+	.start_tx	= jsm_tty_start_tx,
+	.send_xchar	= jsm_tty_send_xchar,
+	.stop_rx	= jsm_tty_stop_rx,
+	.break_ctl	= jsm_tty_break,
+	.startup	= jsm_tty_open,
+	.shutdown	= jsm_tty_close,
+	.set_termios	= jsm_tty_set_termios,
+	.type		= jsm_tty_type,
+	.release_port	= jsm_tty_release_port,
+	.request_port	= jsm_tty_request_port,
+	.config_port	= jsm_config_port,
+};
+
+/*
+ * jsm_tty_init()
+ *
+ * Init the tty subsystem.  Called once per board after board has been
+ * downloaded and init'ed.
+ */
+int jsm_tty_init(struct jsm_board *brd)
+{
+	int i;
+	void __iomem *vaddr;
+	struct jsm_channel *ch;
+
+	if (!brd)
+		return -ENXIO;
+
+	jsm_dbg(INIT, &brd->pci_dev, "start\n");
+
+	/*
+	 * Initialize board structure elements.
+	 */
+
+	brd->nasync = brd->maxports;
+
+	/*
+	 * Allocate channel memory that might not have been allocated
+	 * when the driver was first loaded.
+	 */
+	for (i = 0; i < brd->nasync; i++) {
+		if (!brd->channels[i]) {
+
+			/*
+			 * Okay to malloc with GFP_KERNEL, we are not at
+			 * interrupt context, and there are no locks held.
+			 */
+			brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL);
+			if (!brd->channels[i]) {
+				jsm_dbg(CORE, &brd->pci_dev,
+					"%s:%d Unable to allocate memory for channel struct\n",
+					__FILE__, __LINE__);
+			}
+		}
+	}
+
+	ch = brd->channels[0];
+	vaddr = brd->re_map_membase;
+
+	/* Set up channel variables */
+	for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
+
+		if (!brd->channels[i])
+			continue;
+
+		spin_lock_init(&ch->ch_lock);
+
+		if (brd->bd_uart_offset == 0x200)
+			ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
+		else
+			ch->ch_cls_uart =  vaddr + (brd->bd_uart_offset * i);
+
+		ch->ch_bd = brd;
+		ch->ch_portnum = i;
+
+		/* .25 second delay */
+		ch->ch_close_delay = 250;
+
+		init_waitqueue_head(&ch->ch_flags_wait);
+	}
+
+	jsm_dbg(INIT, &brd->pci_dev, "finish\n");
+	return 0;
+}
+
+int jsm_uart_port_init(struct jsm_board *brd)
+{
+	int i, rc;
+	unsigned int line;
+
+	if (!brd)
+		return -ENXIO;
+
+	jsm_dbg(INIT, &brd->pci_dev, "start\n");
+
+	/*
+	 * Initialize board structure elements.
+	 */
+
+	brd->nasync = brd->maxports;
+
+	/* Set up channel variables */
+	for (i = 0; i < brd->nasync; i++) {
+
+		if (!brd->channels[i])
+			continue;
+
+		brd->channels[i]->uart_port.irq = brd->irq;
+		brd->channels[i]->uart_port.uartclk = 14745600;
+		brd->channels[i]->uart_port.type = PORT_JSM;
+		brd->channels[i]->uart_port.iotype = UPIO_MEM;
+		brd->channels[i]->uart_port.membase = brd->re_map_membase;
+		brd->channels[i]->uart_port.fifosize = 16;
+		brd->channels[i]->uart_port.ops = &jsm_ops;
+		line = find_first_zero_bit(linemap, MAXLINES);
+		if (line >= MAXLINES) {
+			printk(KERN_INFO "jsm: linemap is full, added device failed\n");
+			continue;
+		} else
+			set_bit(line, linemap);
+		brd->channels[i]->uart_port.line = line;
+		rc = uart_add_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
+		if (rc) {
+			printk(KERN_INFO "jsm: Port %d failed. Aborting...\n", i);
+			return rc;
+		} else
+			printk(KERN_INFO "jsm: Port %d added\n", i);
+	}
+
+	jsm_dbg(INIT, &brd->pci_dev, "finish\n");
+	return 0;
+}
+
+int jsm_remove_uart_port(struct jsm_board *brd)
+{
+	int i;
+	struct jsm_channel *ch;
+
+	if (!brd)
+		return -ENXIO;
+
+	jsm_dbg(INIT, &brd->pci_dev, "start\n");
+
+	/*
+	 * Initialize board structure elements.
+	 */
+
+	brd->nasync = brd->maxports;
+
+	/* Set up channel variables */
+	for (i = 0; i < brd->nasync; i++) {
+
+		if (!brd->channels[i])
+			continue;
+
+		ch = brd->channels[i];
+
+		clear_bit(ch->uart_port.line, linemap);
+		uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
+	}
+
+	jsm_dbg(INIT, &brd->pci_dev, "finish\n");
+	return 0;
+}
+
+void jsm_input(struct jsm_channel *ch)
+{
+	struct jsm_board *bd;
+	struct tty_struct *tp;
+	struct tty_port *port;
+	u32 rmask;
+	u16 head;
+	u16 tail;
+	int data_len;
+	unsigned long lock_flags;
+	int len = 0;
+	int s = 0;
+	int i = 0;
+
+	jsm_dbg(READ, &ch->ch_bd->pci_dev, "start\n");
+
+	port = &ch->uart_port.state->port;
+	tp = port->tty;
+
+	bd = ch->ch_bd;
+	if (!bd)
+		return;
+
+	spin_lock_irqsave(&ch->ch_lock, lock_flags);
+
+	/*
+	 *Figure the number of characters in the buffer.
+	 *Exit immediately if none.
+	 */
+
+	rmask = RQUEUEMASK;
+
+	head = ch->ch_r_head & rmask;
+	tail = ch->ch_r_tail & rmask;
+
+	data_len = (head - tail) & rmask;
+	if (data_len == 0) {
+		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+		return;
+	}
+
+	jsm_dbg(READ, &ch->ch_bd->pci_dev, "start\n");
+
+	/*
+	 *If the device is not open, or CREAD is off, flush
+	 *input data and return immediately.
+	 */
+	if (!tp || !C_CREAD(tp)) {
+
+		jsm_dbg(READ, &ch->ch_bd->pci_dev,
+			"input. dropping %d bytes on port %d...\n",
+			data_len, ch->ch_portnum);
+		ch->ch_r_head = tail;
+
+		/* Force queue flow control to be released, if needed */
+		jsm_check_queue_flow_control(ch);
+
+		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+		return;
+	}
+
+	/*
+	 * If we are throttled, simply don't read any data.
+	 */
+	if (ch->ch_flags & CH_STOPI) {
+		spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+		jsm_dbg(READ, &ch->ch_bd->pci_dev,
+			"Port %d throttled, not reading any data. head: %x tail: %x\n",
+			ch->ch_portnum, head, tail);
+		return;
+	}
+
+	jsm_dbg(READ, &ch->ch_bd->pci_dev, "start 2\n");
+
+	len = tty_buffer_request_room(port, data_len);
+
+	/*
+	 * len now contains the most amount of data we can copy,
+	 * bounded either by the flip buffer size or the amount
+	 * of data the card actually has pending...
+	 */
+	while (len) {
+		s = ((head >= tail) ? head : RQUEUESIZE) - tail;
+		s = min(s, len);
+
+		if (s <= 0)
+			break;
+
+			/*
+			 * If conditions are such that ld needs to see all
+			 * UART errors, we will have to walk each character
+			 * and error byte and send them to the buffer one at
+			 * a time.
+			 */
+
+		if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
+			for (i = 0; i < s; i++) {
+				u8 chr   = ch->ch_rqueue[tail + i];
+				u8 error = ch->ch_equeue[tail + i];
+				char flag = TTY_NORMAL;
+
+				/*
+				 * Give the Linux ld the flags in the format it
+				 * likes.
+				 */
+				if (error & UART_LSR_BI)
+					flag = TTY_BREAK;
+				else if (error & UART_LSR_PE)
+					flag = TTY_PARITY;
+				else if (error & UART_LSR_FE)
+					flag = TTY_FRAME;
+
+				tty_insert_flip_char(port, chr, flag);
+			}
+		} else {
+			tty_insert_flip_string(port, ch->ch_rqueue + tail, s);
+		}
+		tail += s;
+		len -= s;
+		/* Flip queue if needed */
+		tail &= rmask;
+	}
+
+	ch->ch_r_tail = tail & rmask;
+	ch->ch_e_tail = tail & rmask;
+	jsm_check_queue_flow_control(ch);
+	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+
+	/* Tell the tty layer its okay to "eat" the data now */
+	tty_flip_buffer_push(port);
+
+	jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "finish\n");
+}
+
+static void jsm_carrier(struct jsm_channel *ch)
+{
+	struct jsm_board *bd;
+
+	int virt_carrier = 0;
+	int phys_carrier = 0;
+
+	jsm_dbg(CARR, &ch->ch_bd->pci_dev, "start\n");
+
+	bd = ch->ch_bd;
+	if (!bd)
+		return;
+
+	if (ch->ch_mistat & UART_MSR_DCD) {
+		jsm_dbg(CARR, &ch->ch_bd->pci_dev, "mistat: %x D_CD: %x\n",
+			ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
+		phys_carrier = 1;
+	}
+
+	if (ch->ch_c_cflag & CLOCAL)
+		virt_carrier = 1;
+
+	jsm_dbg(CARR, &ch->ch_bd->pci_dev, "DCD: physical: %d virt: %d\n",
+		phys_carrier, virt_carrier);
+
+	/*
+	 * Test for a VIRTUAL carrier transition to HIGH.
+	 */
+	if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
+
+		/*
+		 * When carrier rises, wake any threads waiting
+		 * for carrier in the open routine.
+		 */
+
+		jsm_dbg(CARR, &ch->ch_bd->pci_dev, "carrier: virt DCD rose\n");
+
+		if (waitqueue_active(&(ch->ch_flags_wait)))
+			wake_up_interruptible(&ch->ch_flags_wait);
+	}
+
+	/*
+	 * Test for a PHYSICAL carrier transition to HIGH.
+	 */
+	if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
+
+		/*
+		 * When carrier rises, wake any threads waiting
+		 * for carrier in the open routine.
+		 */
+
+		jsm_dbg(CARR, &ch->ch_bd->pci_dev,
+			"carrier: physical DCD rose\n");
+
+		if (waitqueue_active(&(ch->ch_flags_wait)))
+			wake_up_interruptible(&ch->ch_flags_wait);
+	}
+
+	/*
+	 *  Test for a PHYSICAL transition to low, so long as we aren't
+	 *  currently ignoring physical transitions (which is what "virtual
+	 *  carrier" indicates).
+	 *
+	 *  The transition of the virtual carrier to low really doesn't
+	 *  matter... it really only means "ignore carrier state", not
+	 *  "make pretend that carrier is there".
+	 */
+	if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
+			&& (phys_carrier == 0)) {
+		/*
+		 *	When carrier drops:
+		 *
+		 *	Drop carrier on all open units.
+		 *
+		 *	Flush queues, waking up any task waiting in the
+		 *	line discipline.
+		 *
+		 *	Send a hangup to the control terminal.
+		 *
+		 *	Enable all select calls.
+		 */
+		if (waitqueue_active(&(ch->ch_flags_wait)))
+			wake_up_interruptible(&ch->ch_flags_wait);
+	}
+
+	/*
+	 *  Make sure that our cached values reflect the current reality.
+	 */
+	if (virt_carrier == 1)
+		ch->ch_flags |= CH_FCAR;
+	else
+		ch->ch_flags &= ~CH_FCAR;
+
+	if (phys_carrier == 1)
+		ch->ch_flags |= CH_CD;
+	else
+		ch->ch_flags &= ~CH_CD;
+}
+
+
+void jsm_check_queue_flow_control(struct jsm_channel *ch)
+{
+	struct board_ops *bd_ops = ch->ch_bd->bd_ops;
+	int qleft;
+
+	/* Store how much space we have left in the queue */
+	qleft = ch->ch_r_tail - ch->ch_r_head - 1;
+	if (qleft < 0)
+		qleft += RQUEUEMASK + 1;
+
+	/*
+	 * Check to see if we should enforce flow control on our queue because
+	 * the ld (or user) isn't reading data out of our queue fast enuf.
+	 *
+	 * NOTE: This is done based on what the current flow control of the
+	 * port is set for.
+	 *
+	 * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
+	 *	This will cause the UART's FIFO to back up, and force
+	 *	the RTS signal to be dropped.
+	 * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
+	 *	the other side, in hopes it will stop sending data to us.
+	 * 3) NONE - Nothing we can do.  We will simply drop any extra data
+	 *	that gets sent into us when the queue fills up.
+	 */
+	if (qleft < 256) {
+		/* HWFLOW */
+		if (ch->ch_c_cflag & CRTSCTS) {
+			if (!(ch->ch_flags & CH_RECEIVER_OFF)) {
+				bd_ops->disable_receiver(ch);
+				ch->ch_flags |= (CH_RECEIVER_OFF);
+				jsm_dbg(READ, &ch->ch_bd->pci_dev,
+					"Internal queue hit hilevel mark (%d)! Turning off interrupts\n",
+					qleft);
+			}
+		}
+		/* SWFLOW */
+		else if (ch->ch_c_iflag & IXOFF) {
+			if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
+				bd_ops->send_stop_character(ch);
+				ch->ch_stops_sent++;
+				jsm_dbg(READ, &ch->ch_bd->pci_dev,
+					"Sending stop char! Times sent: %x\n",
+					ch->ch_stops_sent);
+			}
+		}
+	}
+
+	/*
+	 * Check to see if we should unenforce flow control because
+	 * ld (or user) finally read enuf data out of our queue.
+	 *
+	 * NOTE: This is done based on what the current flow control of the
+	 * port is set for.
+	 *
+	 * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
+	 *	This will cause the UART's FIFO to raise RTS back up,
+	 *	which will allow the other side to start sending data again.
+	 * 2) SWFLOW (IXOFF) - Send a start character to
+	 *	the other side, so it will start sending data to us again.
+	 * 3) NONE - Do nothing. Since we didn't do anything to turn off the
+	 *	other side, we don't need to do anything now.
+	 */
+	if (qleft > (RQUEUESIZE / 2)) {
+		/* HWFLOW */
+		if (ch->ch_c_cflag & CRTSCTS) {
+			if (ch->ch_flags & CH_RECEIVER_OFF) {
+				bd_ops->enable_receiver(ch);
+				ch->ch_flags &= ~(CH_RECEIVER_OFF);
+				jsm_dbg(READ, &ch->ch_bd->pci_dev,
+					"Internal queue hit lowlevel mark (%d)! Turning on interrupts\n",
+					qleft);
+			}
+		}
+		/* SWFLOW */
+		else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
+			ch->ch_stops_sent = 0;
+			bd_ops->send_start_character(ch);
+			jsm_dbg(READ, &ch->ch_bd->pci_dev,
+				"Sending start char!\n");
+		}
+	}
+}
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c
new file mode 100644
index 000000000..e93850f64
--- /dev/null
+++ b/drivers/tty/serial/kgdb_nmi.c
@@ -0,0 +1,381 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KGDB NMI serial console
+ *
+ * Copyright 2010 Google, Inc.
+ *		  Arve Hjønnevåg <arve@android.com>
+ *		  Colin Cross <ccross@android.com>
+ * Copyright 2012 Linaro Ltd.
+ *		  Anton Vorontsov <anton.vorontsov@linaro.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/compiler.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/atomic.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/interrupt.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/kfifo.h>
+#include <linux/kgdb.h>
+#include <linux/kdb.h>
+
+static int kgdb_nmi_knock = 1;
+module_param_named(knock, kgdb_nmi_knock, int, 0600);
+MODULE_PARM_DESC(knock, "if set to 1 (default), the special '$3#33' command " \
+			"must be used to enter the debugger; when set to 0, " \
+			"hitting return key is enough to enter the debugger; " \
+			"when set to -1, the debugger is entered immediately " \
+			"upon NMI");
+
+static char *kgdb_nmi_magic = "$3#33";
+module_param_named(magic, kgdb_nmi_magic, charp, 0600);
+MODULE_PARM_DESC(magic, "magic sequence to enter NMI debugger (default $3#33)");
+
+static atomic_t kgdb_nmi_num_readers = ATOMIC_INIT(0);
+
+static int kgdb_nmi_console_setup(struct console *co, char *options)
+{
+	arch_kgdb_ops.enable_nmi(1);
+
+	/* The NMI console uses the dbg_io_ops to issue console messages. To
+	 * avoid duplicate messages during kdb sessions we must inform kdb's
+	 * I/O utilities that messages sent to the console will automatically
+	 * be displayed on the dbg_io.
+	 */
+	dbg_io_ops->cons = co;
+
+	return 0;
+}
+
+static void kgdb_nmi_console_write(struct console *co, const char *s, uint c)
+{
+	int i;
+
+	for (i = 0; i < c; i++)
+		dbg_io_ops->write_char(s[i]);
+}
+
+static struct tty_driver *kgdb_nmi_tty_driver;
+
+static struct tty_driver *kgdb_nmi_console_device(struct console *co, int *idx)
+{
+	*idx = co->index;
+	return kgdb_nmi_tty_driver;
+}
+
+static struct console kgdb_nmi_console = {
+	.name	= "ttyNMI",
+	.setup  = kgdb_nmi_console_setup,
+	.write	= kgdb_nmi_console_write,
+	.device	= kgdb_nmi_console_device,
+	.flags	= CON_PRINTBUFFER | CON_ANYTIME,
+	.index	= -1,
+};
+
+/*
+ * This is usually the maximum rate on debug ports. We make fifo large enough
+ * to make copy-pasting to the terminal usable.
+ */
+#define KGDB_NMI_BAUD		115200
+#define KGDB_NMI_FIFO_SIZE	roundup_pow_of_two(KGDB_NMI_BAUD / 8 / HZ)
+
+struct kgdb_nmi_tty_priv {
+	struct tty_port port;
+	struct timer_list timer;
+	STRUCT_KFIFO(char, KGDB_NMI_FIFO_SIZE) fifo;
+};
+
+static struct tty_port *kgdb_nmi_port;
+
+static void kgdb_tty_recv(int ch)
+{
+	struct kgdb_nmi_tty_priv *priv;
+	char c = ch;
+
+	if (!kgdb_nmi_port || ch < 0)
+		return;
+	/*
+	 * Can't use port->tty->driver_data as tty might be not there. Timer
+	 * will check for tty and will get the ref, but here we don't have to
+	 * do that, and actually, we can't: we're in NMI context, no locks are
+	 * possible.
+	 */
+	priv = container_of(kgdb_nmi_port, struct kgdb_nmi_tty_priv, port);
+	kfifo_in(&priv->fifo, &c, 1);
+}
+
+static int kgdb_nmi_poll_one_knock(void)
+{
+	static int n;
+	int c;
+	const char *magic = kgdb_nmi_magic;
+	size_t m = strlen(magic);
+	bool printch = false;
+
+	c = dbg_io_ops->read_char();
+	if (c == NO_POLL_CHAR)
+		return c;
+
+	if (!kgdb_nmi_knock && (c == '\r' || c == '\n')) {
+		return 1;
+	} else if (c == magic[n]) {
+		n = (n + 1) % m;
+		if (!n)
+			return 1;
+		printch = true;
+	} else {
+		n = 0;
+	}
+
+	if (atomic_read(&kgdb_nmi_num_readers)) {
+		kgdb_tty_recv(c);
+		return 0;
+	}
+
+	if (printch) {
+		kdb_printf("%c", c);
+		return 0;
+	}
+
+	kdb_printf("\r%s %s to enter the debugger> %*s",
+		   kgdb_nmi_knock ? "Type" : "Hit",
+		   kgdb_nmi_knock ? magic  : "<return>", (int)m, "");
+	while (m--)
+		kdb_printf("\b");
+	return 0;
+}
+
+/**
+ * kgdb_nmi_poll_knock - Check if it is time to enter the debugger
+ *
+ * "Serial ports are often noisy, especially when muxed over another port (we
+ * often use serial over the headset connector). Noise on the async command
+ * line just causes characters that are ignored, on a command line that blocked
+ * execution noise would be catastrophic." -- Colin Cross
+ *
+ * So, this function implements KGDB/KDB knocking on the serial line: we won't
+ * enter the debugger until we receive a known magic phrase (which is actually
+ * "$3#33", known as "escape to KDB" command. There is also a relaxed variant
+ * of knocking, i.e. just pressing the return key is enough to enter the
+ * debugger. And if knocking is disabled, the function always returns 1.
+ */
+bool kgdb_nmi_poll_knock(void)
+{
+	if (kgdb_nmi_knock < 0)
+		return true;
+
+	while (1) {
+		int ret;
+
+		ret = kgdb_nmi_poll_one_knock();
+		if (ret == NO_POLL_CHAR)
+			return false;
+		else if (ret == 1)
+			break;
+	}
+	return true;
+}
+
+/*
+ * The tasklet is cheap, it does not cause wakeups when reschedules itself,
+ * instead it waits for the next tick.
+ */
+static void kgdb_nmi_tty_receiver(struct timer_list *t)
+{
+	struct kgdb_nmi_tty_priv *priv = from_timer(priv, t, timer);
+	char ch;
+
+	priv->timer.expires = jiffies + (HZ/100);
+	add_timer(&priv->timer);
+
+	if (likely(!atomic_read(&kgdb_nmi_num_readers) ||
+		   !kfifo_len(&priv->fifo)))
+		return;
+
+	while (kfifo_out(&priv->fifo, &ch, 1))
+		tty_insert_flip_char(&priv->port, ch, TTY_NORMAL);
+	tty_flip_buffer_push(&priv->port);
+}
+
+static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct kgdb_nmi_tty_priv *priv =
+	    container_of(port, struct kgdb_nmi_tty_priv, port);
+
+	kgdb_nmi_port = port;
+	priv->timer.expires = jiffies + (HZ/100);
+	add_timer(&priv->timer);
+
+	return 0;
+}
+
+static void kgdb_nmi_tty_shutdown(struct tty_port *port)
+{
+	struct kgdb_nmi_tty_priv *priv =
+	    container_of(port, struct kgdb_nmi_tty_priv, port);
+
+	del_timer(&priv->timer);
+	kgdb_nmi_port = NULL;
+}
+
+static const struct tty_port_operations kgdb_nmi_tty_port_ops = {
+	.activate	= kgdb_nmi_tty_activate,
+	.shutdown	= kgdb_nmi_tty_shutdown,
+};
+
+static int kgdb_nmi_tty_install(struct tty_driver *drv, struct tty_struct *tty)
+{
+	struct kgdb_nmi_tty_priv *priv;
+	int ret;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	INIT_KFIFO(priv->fifo);
+	timer_setup(&priv->timer, kgdb_nmi_tty_receiver, 0);
+	tty_port_init(&priv->port);
+	priv->port.ops = &kgdb_nmi_tty_port_ops;
+	tty->driver_data = priv;
+
+	ret = tty_port_install(&priv->port, drv, tty);
+	if (ret) {
+		pr_err("%s: can't install tty port: %d\n", __func__, ret);
+		goto err;
+	}
+	return 0;
+err:
+	tty_port_destroy(&priv->port);
+	kfree(priv);
+	return ret;
+}
+
+static void kgdb_nmi_tty_cleanup(struct tty_struct *tty)
+{
+	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+
+	tty->driver_data = NULL;
+	tty_port_destroy(&priv->port);
+	kfree(priv);
+}
+
+static int kgdb_nmi_tty_open(struct tty_struct *tty, struct file *file)
+{
+	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+	unsigned int mode = file->f_flags & O_ACCMODE;
+	int ret;
+
+	ret = tty_port_open(&priv->port, tty, file);
+	if (!ret && (mode == O_RDONLY || mode == O_RDWR))
+		atomic_inc(&kgdb_nmi_num_readers);
+
+	return ret;
+}
+
+static void kgdb_nmi_tty_close(struct tty_struct *tty, struct file *file)
+{
+	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+	unsigned int mode = file->f_flags & O_ACCMODE;
+
+	if (mode == O_RDONLY || mode == O_RDWR)
+		atomic_dec(&kgdb_nmi_num_readers);
+
+	tty_port_close(&priv->port, tty, file);
+}
+
+static void kgdb_nmi_tty_hangup(struct tty_struct *tty)
+{
+	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+
+	tty_port_hangup(&priv->port);
+}
+
+static unsigned int kgdb_nmi_tty_write_room(struct tty_struct *tty)
+{
+	/* Actually, we can handle any amount as we use polled writes. */
+	return 2048;
+}
+
+static ssize_t kgdb_nmi_tty_write(struct tty_struct *tty, const u8 *buf,
+				  size_t c)
+{
+	int i;
+
+	for (i = 0; i < c; i++)
+		dbg_io_ops->write_char(buf[i]);
+	return c;
+}
+
+static const struct tty_operations kgdb_nmi_tty_ops = {
+	.open		= kgdb_nmi_tty_open,
+	.close		= kgdb_nmi_tty_close,
+	.install	= kgdb_nmi_tty_install,
+	.cleanup	= kgdb_nmi_tty_cleanup,
+	.hangup		= kgdb_nmi_tty_hangup,
+	.write_room	= kgdb_nmi_tty_write_room,
+	.write		= kgdb_nmi_tty_write,
+};
+
+int kgdb_register_nmi_console(void)
+{
+	int ret;
+
+	if (!arch_kgdb_ops.enable_nmi)
+		return 0;
+
+	kgdb_nmi_tty_driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
+	if (IS_ERR(kgdb_nmi_tty_driver)) {
+		pr_err("%s: cannot allocate tty\n", __func__);
+		return PTR_ERR(kgdb_nmi_tty_driver);
+	}
+	kgdb_nmi_tty_driver->driver_name	= "ttyNMI";
+	kgdb_nmi_tty_driver->name		= "ttyNMI";
+	kgdb_nmi_tty_driver->num		= 1;
+	kgdb_nmi_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
+	kgdb_nmi_tty_driver->subtype		= SERIAL_TYPE_NORMAL;
+	kgdb_nmi_tty_driver->init_termios	= tty_std_termios;
+	tty_termios_encode_baud_rate(&kgdb_nmi_tty_driver->init_termios,
+				     KGDB_NMI_BAUD, KGDB_NMI_BAUD);
+	tty_set_operations(kgdb_nmi_tty_driver, &kgdb_nmi_tty_ops);
+
+	ret = tty_register_driver(kgdb_nmi_tty_driver);
+	if (ret) {
+		pr_err("%s: can't register tty driver: %d\n", __func__, ret);
+		goto err_drv_reg;
+	}
+
+	register_console(&kgdb_nmi_console);
+
+	return 0;
+err_drv_reg:
+	tty_driver_kref_put(kgdb_nmi_tty_driver);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kgdb_register_nmi_console);
+
+int kgdb_unregister_nmi_console(void)
+{
+	int ret;
+
+	if (!arch_kgdb_ops.enable_nmi)
+		return 0;
+	arch_kgdb_ops.enable_nmi(0);
+
+	ret = unregister_console(&kgdb_nmi_console);
+	if (ret)
+		return ret;
+
+	tty_unregister_driver(kgdb_nmi_tty_driver);
+	tty_driver_kref_put(kgdb_nmi_tty_driver);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kgdb_unregister_nmi_console);
diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
new file mode 100644
index 000000000..7ce7bb164
--- /dev/null
+++ b/drivers/tty/serial/kgdboc.c
@@ -0,0 +1,630 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Based on the same principle as kgdboe using the NETPOLL api, this
+ * driver uses a console polling api to implement a gdb serial inteface
+ * which is multiplexed on a console port.
+ *
+ * Maintainer: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/kgdb.h>
+#include <linux/kdb.h>
+#include <linux/tty.h>
+#include <linux/console.h>
+#include <linux/vt_kern.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+
+#define MAX_CONFIG_LEN		40
+
+static struct kgdb_io		kgdboc_io_ops;
+
+/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
+static int configured		= -1;
+static DEFINE_MUTEX(config_mutex);
+
+static char config[MAX_CONFIG_LEN];
+static struct kparam_string kps = {
+	.string			= config,
+	.maxlen			= MAX_CONFIG_LEN,
+};
+
+static int kgdboc_use_kms;  /* 1 if we use kernel mode switching */
+static struct tty_driver	*kgdb_tty_driver;
+static int			kgdb_tty_line;
+
+static struct platform_device *kgdboc_pdev;
+
+#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)
+static struct kgdb_io		kgdboc_earlycon_io_ops;
+static int                      (*earlycon_orig_exit)(struct console *con);
+#endif /* IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */
+
+#ifdef CONFIG_KDB_KEYBOARD
+static int kgdboc_reset_connect(struct input_handler *handler,
+				struct input_dev *dev,
+				const struct input_device_id *id)
+{
+	input_reset_device(dev);
+
+	/* Return an error - we do not want to bind, just to reset */
+	return -ENODEV;
+}
+
+static void kgdboc_reset_disconnect(struct input_handle *handle)
+{
+	/* We do not expect anyone to actually bind to us */
+	BUG();
+}
+
+static const struct input_device_id kgdboc_reset_ids[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+		.evbit = { BIT_MASK(EV_KEY) },
+	},
+	{ }
+};
+
+static struct input_handler kgdboc_reset_handler = {
+	.connect	= kgdboc_reset_connect,
+	.disconnect	= kgdboc_reset_disconnect,
+	.name		= "kgdboc_reset",
+	.id_table	= kgdboc_reset_ids,
+};
+
+static DEFINE_MUTEX(kgdboc_reset_mutex);
+
+static void kgdboc_restore_input_helper(struct work_struct *dummy)
+{
+	/*
+	 * We need to take a mutex to prevent several instances of
+	 * this work running on different CPUs so they don't try
+	 * to register again already registered handler.
+	 */
+	mutex_lock(&kgdboc_reset_mutex);
+
+	if (input_register_handler(&kgdboc_reset_handler) == 0)
+		input_unregister_handler(&kgdboc_reset_handler);
+
+	mutex_unlock(&kgdboc_reset_mutex);
+}
+
+static DECLARE_WORK(kgdboc_restore_input_work, kgdboc_restore_input_helper);
+
+static void kgdboc_restore_input(void)
+{
+	if (likely(system_state == SYSTEM_RUNNING))
+		schedule_work(&kgdboc_restore_input_work);
+}
+
+static int kgdboc_register_kbd(char **cptr)
+{
+	if (strncmp(*cptr, "kbd", 3) == 0 ||
+		strncmp(*cptr, "kdb", 3) == 0) {
+		if (kdb_poll_idx < KDB_POLL_FUNC_MAX) {
+			kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char;
+			kdb_poll_idx++;
+			if (cptr[0][3] == ',')
+				*cptr += 4;
+			else
+				return 1;
+		}
+	}
+	return 0;
+}
+
+static void kgdboc_unregister_kbd(void)
+{
+	int i;
+
+	for (i = 0; i < kdb_poll_idx; i++) {
+		if (kdb_poll_funcs[i] == kdb_get_kbd_char) {
+			kdb_poll_idx--;
+			kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx];
+			kdb_poll_funcs[kdb_poll_idx] = NULL;
+			i--;
+		}
+	}
+	flush_work(&kgdboc_restore_input_work);
+}
+#else /* ! CONFIG_KDB_KEYBOARD */
+#define kgdboc_register_kbd(x) 0
+#define kgdboc_unregister_kbd()
+#define kgdboc_restore_input()
+#endif /* ! CONFIG_KDB_KEYBOARD */
+
+#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)
+static void cleanup_earlycon(void)
+{
+	if (kgdboc_earlycon_io_ops.cons)
+		kgdb_unregister_io_module(&kgdboc_earlycon_io_ops);
+}
+#else /* !IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */
+static inline void cleanup_earlycon(void) { }
+#endif /* !IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */
+
+static void cleanup_kgdboc(void)
+{
+	cleanup_earlycon();
+
+	if (configured != 1)
+		return;
+
+	if (kgdb_unregister_nmi_console())
+		return;
+	kgdboc_unregister_kbd();
+	kgdb_unregister_io_module(&kgdboc_io_ops);
+}
+
+static int configure_kgdboc(void)
+{
+	struct tty_driver *p;
+	int tty_line = 0;
+	int err = -ENODEV;
+	char *cptr = config;
+	struct console *cons;
+	int cookie;
+
+	if (!strlen(config) || isspace(config[0])) {
+		err = 0;
+		goto noconfig;
+	}
+
+	kgdboc_io_ops.cons = NULL;
+	kgdb_tty_driver = NULL;
+
+	kgdboc_use_kms = 0;
+	if (strncmp(cptr, "kms,", 4) == 0) {
+		cptr += 4;
+		kgdboc_use_kms = 1;
+	}
+
+	if (kgdboc_register_kbd(&cptr))
+		goto do_register;
+
+	p = tty_find_polling_driver(cptr, &tty_line);
+	if (!p)
+		goto noconfig;
+
+	/*
+	 * Take console_lock to serialize device() callback with
+	 * other console operations. For example, fg_console is
+	 * modified under console_lock when switching vt.
+	 */
+	console_lock();
+
+	cookie = console_srcu_read_lock();
+	for_each_console_srcu(cons) {
+		int idx;
+		if (cons->device && cons->device(cons, &idx) == p &&
+		    idx == tty_line) {
+			kgdboc_io_ops.cons = cons;
+			break;
+		}
+	}
+	console_srcu_read_unlock(cookie);
+
+	console_unlock();
+
+	kgdb_tty_driver = p;
+	kgdb_tty_line = tty_line;
+
+do_register:
+	err = kgdb_register_io_module(&kgdboc_io_ops);
+	if (err)
+		goto noconfig;
+
+	err = kgdb_register_nmi_console();
+	if (err)
+		goto nmi_con_failed;
+
+	configured = 1;
+
+	return 0;
+
+nmi_con_failed:
+	kgdb_unregister_io_module(&kgdboc_io_ops);
+noconfig:
+	kgdboc_unregister_kbd();
+	configured = 0;
+
+	return err;
+}
+
+static int kgdboc_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+
+	mutex_lock(&config_mutex);
+	if (configured != 1) {
+		ret = configure_kgdboc();
+
+		/* Convert "no device" to "defer" so we'll keep trying */
+		if (ret == -ENODEV)
+			ret = -EPROBE_DEFER;
+	}
+	mutex_unlock(&config_mutex);
+
+	return ret;
+}
+
+static struct platform_driver kgdboc_platform_driver = {
+	.probe = kgdboc_probe,
+	.driver = {
+		.name = "kgdboc",
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init init_kgdboc(void)
+{
+	int ret;
+
+	/*
+	 * kgdboc is a little bit of an odd "platform_driver".  It can be
+	 * up and running long before the platform_driver object is
+	 * created and thus doesn't actually store anything in it.  There's
+	 * only one instance of kgdb so anything is stored as global state.
+	 * The platform_driver is only created so that we can leverage the
+	 * kernel's mechanisms (like -EPROBE_DEFER) to call us when our
+	 * underlying tty is ready.  Here we init our platform driver and
+	 * then create the single kgdboc instance.
+	 */
+	ret = platform_driver_register(&kgdboc_platform_driver);
+	if (ret)
+		return ret;
+
+	kgdboc_pdev = platform_device_alloc("kgdboc", PLATFORM_DEVID_NONE);
+	if (!kgdboc_pdev) {
+		ret = -ENOMEM;
+		goto err_did_register;
+	}
+
+	ret = platform_device_add(kgdboc_pdev);
+	if (!ret)
+		return 0;
+
+	platform_device_put(kgdboc_pdev);
+
+err_did_register:
+	platform_driver_unregister(&kgdboc_platform_driver);
+	return ret;
+}
+
+static void exit_kgdboc(void)
+{
+	mutex_lock(&config_mutex);
+	cleanup_kgdboc();
+	mutex_unlock(&config_mutex);
+
+	platform_device_unregister(kgdboc_pdev);
+	platform_driver_unregister(&kgdboc_platform_driver);
+}
+
+static int kgdboc_get_char(void)
+{
+	if (!kgdb_tty_driver)
+		return -1;
+	return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver,
+						kgdb_tty_line);
+}
+
+static void kgdboc_put_char(u8 chr)
+{
+	if (!kgdb_tty_driver)
+		return;
+	kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver,
+					kgdb_tty_line, chr);
+}
+
+static int param_set_kgdboc_var(const char *kmessage,
+				const struct kernel_param *kp)
+{
+	size_t len = strlen(kmessage);
+	int ret = 0;
+
+	if (len >= MAX_CONFIG_LEN) {
+		pr_err("config string too long\n");
+		return -ENOSPC;
+	}
+
+	if (kgdb_connected) {
+		pr_err("Cannot reconfigure while KGDB is connected.\n");
+		return -EBUSY;
+	}
+
+	mutex_lock(&config_mutex);
+
+	strcpy(config, kmessage);
+	/* Chop out \n char as a result of echo */
+	if (len && config[len - 1] == '\n')
+		config[len - 1] = '\0';
+
+	if (configured == 1)
+		cleanup_kgdboc();
+
+	/*
+	 * Configure with the new params as long as init already ran.
+	 * Note that we can get called before init if someone loads us
+	 * with "modprobe kgdboc kgdboc=..." or if they happen to use
+	 * the odd syntax of "kgdboc.kgdboc=..." on the kernel command.
+	 */
+	if (configured >= 0)
+		ret = configure_kgdboc();
+
+	/*
+	 * If we couldn't configure then clear out the config.  Note that
+	 * specifying an invalid config on the kernel command line vs.
+	 * through sysfs have slightly different behaviors.  If we fail
+	 * to configure what was specified on the kernel command line
+	 * we'll leave it in the 'config' and return -EPROBE_DEFER from
+	 * our probe.  When specified through sysfs userspace is
+	 * responsible for loading the tty driver before setting up.
+	 */
+	if (ret)
+		config[0] = '\0';
+
+	mutex_unlock(&config_mutex);
+
+	return ret;
+}
+
+static int dbg_restore_graphics;
+
+static void kgdboc_pre_exp_handler(void)
+{
+	if (!dbg_restore_graphics && kgdboc_use_kms) {
+		dbg_restore_graphics = 1;
+		con_debug_enter(vc_cons[fg_console].d);
+	}
+	/* Increment the module count when the debugger is active */
+	if (!kgdb_connected)
+		try_module_get(THIS_MODULE);
+}
+
+static void kgdboc_post_exp_handler(void)
+{
+	/* decrement the module count when the debugger detaches */
+	if (!kgdb_connected)
+		module_put(THIS_MODULE);
+	if (kgdboc_use_kms && dbg_restore_graphics) {
+		dbg_restore_graphics = 0;
+		con_debug_leave();
+	}
+	kgdboc_restore_input();
+}
+
+static struct kgdb_io kgdboc_io_ops = {
+	.name			= "kgdboc",
+	.read_char		= kgdboc_get_char,
+	.write_char		= kgdboc_put_char,
+	.pre_exception		= kgdboc_pre_exp_handler,
+	.post_exception		= kgdboc_post_exp_handler,
+};
+
+#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)
+static int kgdboc_option_setup(char *opt)
+{
+	if (!opt) {
+		pr_err("config string not provided\n");
+		return 1;
+	}
+
+	if (strlen(opt) >= MAX_CONFIG_LEN) {
+		pr_err("config string too long\n");
+		return 1;
+	}
+	strcpy(config, opt);
+
+	return 1;
+}
+
+__setup("kgdboc=", kgdboc_option_setup);
+
+
+/* This is only available if kgdboc is a built in for early debugging */
+static int __init kgdboc_early_init(char *opt)
+{
+	kgdboc_option_setup(opt);
+	configure_kgdboc();
+	return 0;
+}
+
+early_param("ekgdboc", kgdboc_early_init);
+
+static int kgdboc_earlycon_get_char(void)
+{
+	char c;
+
+	if (!kgdboc_earlycon_io_ops.cons->read(kgdboc_earlycon_io_ops.cons,
+					       &c, 1))
+		return NO_POLL_CHAR;
+
+	return c;
+}
+
+static void kgdboc_earlycon_put_char(u8 chr)
+{
+	kgdboc_earlycon_io_ops.cons->write(kgdboc_earlycon_io_ops.cons, &chr,
+					   1);
+}
+
+static void kgdboc_earlycon_pre_exp_handler(void)
+{
+	struct console *con;
+	static bool already_warned;
+	int cookie;
+
+	if (already_warned)
+		return;
+
+	/*
+	 * When the first normal console comes up the kernel will take all
+	 * the boot consoles out of the list.  Really, we should stop using
+	 * the boot console when it does that but until a TTY is registered
+	 * we have no other choice so we keep using it.  Since not all
+	 * serial drivers might be OK with this, print a warning once per
+	 * boot if we detect this case.
+	 */
+	cookie = console_srcu_read_lock();
+	for_each_console_srcu(con) {
+		if (con == kgdboc_earlycon_io_ops.cons)
+			break;
+	}
+	console_srcu_read_unlock(cookie);
+	if (con)
+		return;
+
+	already_warned = true;
+	pr_warn("kgdboc_earlycon is still using bootconsole\n");
+}
+
+static int kgdboc_earlycon_deferred_exit(struct console *con)
+{
+	/*
+	 * If we get here it means the boot console is going away but we
+	 * don't yet have a suitable replacement.  Don't pass through to
+	 * the original exit routine.  We'll call it later in our deinit()
+	 * function.  For now, restore the original exit() function pointer
+	 * as a sentinal that we've hit this point.
+	 */
+	con->exit = earlycon_orig_exit;
+
+	return 0;
+}
+
+static void kgdboc_earlycon_deinit(void)
+{
+	if (!kgdboc_earlycon_io_ops.cons)
+		return;
+
+	if (kgdboc_earlycon_io_ops.cons->exit == kgdboc_earlycon_deferred_exit)
+		/*
+		 * kgdboc_earlycon is exiting but original boot console exit
+		 * was never called (AKA kgdboc_earlycon_deferred_exit()
+		 * didn't ever run).  Undo our trap.
+		 */
+		kgdboc_earlycon_io_ops.cons->exit = earlycon_orig_exit;
+	else if (kgdboc_earlycon_io_ops.cons->exit)
+		/*
+		 * We skipped calling the exit() routine so we could try to
+		 * keep using the boot console even after it went away.  We're
+		 * finally done so call the function now.
+		 */
+		kgdboc_earlycon_io_ops.cons->exit(kgdboc_earlycon_io_ops.cons);
+
+	kgdboc_earlycon_io_ops.cons = NULL;
+}
+
+static struct kgdb_io kgdboc_earlycon_io_ops = {
+	.name			= "kgdboc_earlycon",
+	.read_char		= kgdboc_earlycon_get_char,
+	.write_char		= kgdboc_earlycon_put_char,
+	.pre_exception		= kgdboc_earlycon_pre_exp_handler,
+	.deinit			= kgdboc_earlycon_deinit,
+};
+
+#define MAX_CONSOLE_NAME_LEN (sizeof((struct console *) 0)->name)
+static char kgdboc_earlycon_param[MAX_CONSOLE_NAME_LEN] __initdata;
+static bool kgdboc_earlycon_late_enable __initdata;
+
+static int __init kgdboc_earlycon_init(char *opt)
+{
+	struct console *con;
+
+	kdb_init(KDB_INIT_EARLY);
+
+	/*
+	 * Look for a matching console, or if the name was left blank just
+	 * pick the first one we find.
+	 */
+
+	/*
+	 * Hold the console_list_lock to guarantee that no consoles are
+	 * unregistered until the kgdboc_earlycon setup is complete.
+	 * Trapping the exit() callback relies on exit() not being
+	 * called until the trap is setup. This also allows safe
+	 * traversal of the console list and race-free reading of @flags.
+	 */
+	console_list_lock();
+	for_each_console(con) {
+		if (con->write && con->read &&
+		    (con->flags & (CON_BOOT | CON_ENABLED)) &&
+		    (!opt || !opt[0] || strcmp(con->name, opt) == 0))
+			break;
+	}
+
+	if (!con) {
+		/*
+		 * Both earlycon and kgdboc_earlycon are initialized during
+		 * early parameter parsing. We cannot guarantee earlycon gets
+		 * in first and, in any case, on ACPI systems earlycon may
+		 * defer its own initialization (usually to somewhere within
+		 * setup_arch() ). To cope with either of these situations
+		 * we can defer our own initialization to a little later in
+		 * the boot.
+		 */
+		if (!kgdboc_earlycon_late_enable) {
+			pr_info("No suitable earlycon yet, will try later\n");
+			if (opt)
+				strscpy(kgdboc_earlycon_param, opt,
+					sizeof(kgdboc_earlycon_param));
+			kgdboc_earlycon_late_enable = true;
+		} else {
+			pr_info("Couldn't find kgdb earlycon\n");
+		}
+		goto unlock;
+	}
+
+	kgdboc_earlycon_io_ops.cons = con;
+	pr_info("Going to register kgdb with earlycon '%s'\n", con->name);
+	if (kgdb_register_io_module(&kgdboc_earlycon_io_ops) != 0) {
+		kgdboc_earlycon_io_ops.cons = NULL;
+		pr_info("Failed to register kgdb with earlycon\n");
+	} else {
+		/* Trap exit so we can keep earlycon longer if needed. */
+		earlycon_orig_exit = con->exit;
+		con->exit = kgdboc_earlycon_deferred_exit;
+	}
+
+unlock:
+	console_list_unlock();
+
+	/* Non-zero means malformed option so we always return zero */
+	return 0;
+}
+
+early_param("kgdboc_earlycon", kgdboc_earlycon_init);
+
+/*
+ * This is only intended for the late adoption of an early console.
+ *
+ * It is not a reliable way to adopt regular consoles because we can not
+ * control what order console initcalls are made and, in any case, many
+ * regular consoles are registered much later in the boot process than
+ * the console initcalls!
+ */
+static int __init kgdboc_earlycon_late_init(void)
+{
+	if (kgdboc_earlycon_late_enable)
+		kgdboc_earlycon_init(kgdboc_earlycon_param);
+	return 0;
+}
+console_initcall(kgdboc_earlycon_late_init);
+
+#endif /* IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */
+
+module_init(init_kgdboc);
+module_exit(exit_kgdboc);
+module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
+MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
+MODULE_DESCRIPTION("KGDB Console TTY Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
new file mode 100644
index 000000000..3adb60c68
--- /dev/null
+++ b/drivers/tty/serial/lantiq.c
@@ -0,0 +1,953 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ * Copyright (C) 2004 Infineon IFAP DC COM CPE
+ * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2007 John Crispin <john@phrozen.org>
+ * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/lantiq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define PORT_LTQ_ASC		111
+#define MAXPORTS		2
+#define UART_DUMMY_UER_RX	1
+#define DRVNAME			"lantiq,asc"
+#ifdef __BIG_ENDIAN
+#define LTQ_ASC_TBUF		(0x0020 + 3)
+#define LTQ_ASC_RBUF		(0x0024 + 3)
+#else
+#define LTQ_ASC_TBUF		0x0020
+#define LTQ_ASC_RBUF		0x0024
+#endif
+#define LTQ_ASC_FSTAT		0x0048
+#define LTQ_ASC_WHBSTATE	0x0018
+#define LTQ_ASC_STATE		0x0014
+#define LTQ_ASC_IRNCR		0x00F8
+#define LTQ_ASC_CLC		0x0000
+#define LTQ_ASC_ID		0x0008
+#define LTQ_ASC_PISEL		0x0004
+#define LTQ_ASC_TXFCON		0x0044
+#define LTQ_ASC_RXFCON		0x0040
+#define LTQ_ASC_CON		0x0010
+#define LTQ_ASC_BG		0x0050
+#define LTQ_ASC_IRNREN		0x00F4
+
+#define ASC_IRNREN_TX		0x1
+#define ASC_IRNREN_RX		0x2
+#define ASC_IRNREN_ERR		0x4
+#define ASC_IRNREN_TX_BUF	0x8
+#define ASC_IRNCR_TIR		0x1
+#define ASC_IRNCR_RIR		0x2
+#define ASC_IRNCR_EIR		0x4
+#define ASC_IRNCR_MASK		GENMASK(2, 0)
+
+#define ASCOPT_CSIZE		0x3
+#define TXFIFO_FL		1
+#define RXFIFO_FL		1
+#define ASCCLC_DISS		0x2
+#define ASCCLC_RMCMASK		0x0000FF00
+#define ASCCLC_RMCOFFSET	8
+#define ASCCON_M_8ASYNC		0x0
+#define ASCCON_M_7ASYNC		0x2
+#define ASCCON_ODD		0x00000020
+#define ASCCON_STP		0x00000080
+#define ASCCON_BRS		0x00000100
+#define ASCCON_FDE		0x00000200
+#define ASCCON_R		0x00008000
+#define ASCCON_FEN		0x00020000
+#define ASCCON_ROEN		0x00080000
+#define ASCCON_TOEN		0x00100000
+#define ASCSTATE_PE		0x00010000
+#define ASCSTATE_FE		0x00020000
+#define ASCSTATE_ROE		0x00080000
+#define ASCSTATE_ANY		(ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
+#define ASCWHBSTATE_CLRREN	0x00000001
+#define ASCWHBSTATE_SETREN	0x00000002
+#define ASCWHBSTATE_CLRPE	0x00000004
+#define ASCWHBSTATE_CLRFE	0x00000008
+#define ASCWHBSTATE_CLRROE	0x00000020
+#define ASCTXFCON_TXFEN		0x0001
+#define ASCTXFCON_TXFFLU	0x0002
+#define ASCTXFCON_TXFITLMASK	0x3F00
+#define ASCTXFCON_TXFITLOFF	8
+#define ASCRXFCON_RXFEN		0x0001
+#define ASCRXFCON_RXFFLU	0x0002
+#define ASCRXFCON_RXFITLMASK	0x3F00
+#define ASCRXFCON_RXFITLOFF	8
+#define ASCFSTAT_RXFFLMASK	0x003F
+#define ASCFSTAT_TXFFLMASK	0x3F00
+#define ASCFSTAT_TXFREEMASK	0x3F000000
+
+static struct ltq_uart_port *lqasc_port[MAXPORTS];
+static struct uart_driver lqasc_reg;
+
+struct ltq_soc_data {
+	int	(*fetch_irq)(struct device *dev, struct ltq_uart_port *ltq_port);
+	int	(*request_irq)(struct uart_port *port);
+	void	(*free_irq)(struct uart_port *port);
+};
+
+struct ltq_uart_port {
+	struct uart_port	port;
+	/* clock used to derive divider */
+	struct clk		*freqclk;
+	/* clock gating of the ASC core */
+	struct clk		*clk;
+	unsigned int		tx_irq;
+	unsigned int		rx_irq;
+	unsigned int		err_irq;
+	unsigned int		common_irq;
+	spinlock_t		lock; /* exclusive access for multi core */
+
+	const struct ltq_soc_data	*soc;
+};
+
+static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
+{
+	u32 tmp = __raw_readl(reg);
+
+	__raw_writel((tmp & ~clear) | set, reg);
+}
+
+static inline struct
+ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
+{
+	return container_of(port, struct ltq_uart_port, port);
+}
+
+static void
+lqasc_stop_tx(struct uart_port *port)
+{
+	return;
+}
+
+static bool lqasc_tx_ready(struct uart_port *port)
+{
+	u32 fstat = __raw_readl(port->membase + LTQ_ASC_FSTAT);
+
+	return FIELD_GET(ASCFSTAT_TXFREEMASK, fstat);
+}
+
+static void
+lqasc_start_tx(struct uart_port *port)
+{
+	unsigned long flags;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	u8 ch;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	uart_port_tx(port, ch,
+		lqasc_tx_ready(port),
+		writeb(ch, port->membase + LTQ_ASC_TBUF));
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	return;
+}
+
+static void
+lqasc_stop_rx(struct uart_port *port)
+{
+	__raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
+}
+
+static int
+lqasc_rx_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned int ch = 0, rsr = 0, fifocnt;
+
+	fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
+		  ASCFSTAT_RXFFLMASK;
+	while (fifocnt--) {
+		u8 flag = TTY_NORMAL;
+		ch = readb(port->membase + LTQ_ASC_RBUF);
+		rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
+			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
+		tty_flip_buffer_push(tport);
+		port->icount.rx++;
+
+		/*
+		 * Note that the error handling code is
+		 * out of the main execution path
+		 */
+		if (rsr & ASCSTATE_ANY) {
+			if (rsr & ASCSTATE_PE) {
+				port->icount.parity++;
+				asc_update_bits(0, ASCWHBSTATE_CLRPE,
+					port->membase + LTQ_ASC_WHBSTATE);
+			} else if (rsr & ASCSTATE_FE) {
+				port->icount.frame++;
+				asc_update_bits(0, ASCWHBSTATE_CLRFE,
+					port->membase + LTQ_ASC_WHBSTATE);
+			}
+			if (rsr & ASCSTATE_ROE) {
+				port->icount.overrun++;
+				asc_update_bits(0, ASCWHBSTATE_CLRROE,
+					port->membase + LTQ_ASC_WHBSTATE);
+			}
+
+			rsr &= port->read_status_mask;
+
+			if (rsr & ASCSTATE_PE)
+				flag = TTY_PARITY;
+			else if (rsr & ASCSTATE_FE)
+				flag = TTY_FRAME;
+		}
+
+		if ((rsr & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tport, ch, flag);
+
+		if (rsr & ASCSTATE_ROE)
+			/*
+			 * Overrun is special, since it's reported
+			 * immediately, and doesn't affect the current
+			 * character
+			 */
+			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+	}
+
+	if (ch != 0)
+		tty_flip_buffer_push(tport);
+
+	return 0;
+}
+
+static irqreturn_t
+lqasc_tx_int(int irq, void *_port)
+{
+	unsigned long flags;
+	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	lqasc_start_tx(port);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t
+lqasc_err_int(int irq, void *_port)
+{
+	unsigned long flags;
+	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
+	/* clear any pending interrupts */
+	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
+		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t
+lqasc_rx_int(int irq, void *_port)
+{
+	unsigned long flags;
+	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
+	lqasc_rx_chars(port);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t lqasc_irq(int irq, void *p)
+{
+	unsigned long flags;
+	u32 stat;
+	struct uart_port *port = p;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	stat = readl(port->membase + LTQ_ASC_IRNCR);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	if (!(stat & ASC_IRNCR_MASK))
+		return IRQ_NONE;
+
+	if (stat & ASC_IRNCR_TIR)
+		lqasc_tx_int(irq, p);
+
+	if (stat & ASC_IRNCR_RIR)
+		lqasc_rx_int(irq, p);
+
+	if (stat & ASC_IRNCR_EIR)
+		lqasc_err_int(irq, p);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int
+lqasc_tx_empty(struct uart_port *port)
+{
+	int status;
+	status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
+		 ASCFSTAT_TXFFLMASK;
+	return status ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int
+lqasc_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
+}
+
+static void
+lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
+{
+}
+
+static void
+lqasc_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int
+lqasc_startup(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	int retval;
+	unsigned long flags;
+
+	if (!IS_ERR(ltq_port->clk))
+		clk_prepare_enable(ltq_port->clk);
+	port->uartclk = clk_get_rate(ltq_port->freqclk);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
+		port->membase + LTQ_ASC_CLC);
+
+	__raw_writel(0, port->membase + LTQ_ASC_PISEL);
+	__raw_writel(
+		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
+		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
+		port->membase + LTQ_ASC_TXFCON);
+	__raw_writel(
+		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
+		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
+		port->membase + LTQ_ASC_RXFCON);
+	/* make sure other settings are written to hardware before
+	 * setting enable bits
+	 */
+	wmb();
+	asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
+		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
+
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+
+	retval = ltq_port->soc->request_irq(port);
+	if (retval)
+		return retval;
+
+	__raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
+		port->membase + LTQ_ASC_IRNREN);
+	return retval;
+}
+
+static void
+lqasc_shutdown(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	unsigned long flags;
+
+	ltq_port->soc->free_irq(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(0, port->membase + LTQ_ASC_CON);
+	asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
+		port->membase + LTQ_ASC_RXFCON);
+	asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
+		port->membase + LTQ_ASC_TXFCON);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	if (!IS_ERR(ltq_port->clk))
+		clk_disable_unprepare(ltq_port->clk);
+}
+
+static void
+lqasc_set_termios(struct uart_port *port, struct ktermios *new,
+		  const struct ktermios *old)
+{
+	unsigned int cflag;
+	unsigned int iflag;
+	unsigned int divisor;
+	unsigned int baud;
+	unsigned int con = 0;
+	unsigned long flags;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	cflag = new->c_cflag;
+	iflag = new->c_iflag;
+
+	switch (cflag & CSIZE) {
+	case CS7:
+		con = ASCCON_M_7ASYNC;
+		break;
+
+	case CS5:
+	case CS6:
+	default:
+		new->c_cflag &= ~ CSIZE;
+		new->c_cflag |= CS8;
+		con = ASCCON_M_8ASYNC;
+		break;
+	}
+
+	cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
+
+	if (cflag & CSTOPB)
+		con |= ASCCON_STP;
+
+	if (cflag & PARENB) {
+		if (!(cflag & PARODD))
+			con &= ~ASCCON_ODD;
+		else
+			con |= ASCCON_ODD;
+	}
+
+	port->read_status_mask = ASCSTATE_ROE;
+	if (iflag & INPCK)
+		port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
+
+	port->ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
+
+	if (iflag & IGNBRK) {
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (iflag & IGNPAR)
+			port->ignore_status_mask |= ASCSTATE_ROE;
+	}
+
+	if ((cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_DUMMY_UER_RX;
+
+	/* set error signals  - framing, parity  and overrun, enable receiver */
+	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+
+	/* set up CON */
+	asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
+
+	/* Set baud rate - take a divider of 2 into account */
+	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+	divisor = uart_get_divisor(port, baud);
+	divisor = divisor / 2 - 1;
+
+	/* disable the baudrate generator */
+	asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
+
+	/* make sure the fractional divider is off */
+	asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
+
+	/* set up to use divisor of 2 */
+	asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
+
+	/* now we can write the new baudrate into the register */
+	__raw_writel(divisor, port->membase + LTQ_ASC_BG);
+
+	/* turn the baudrate generator back on */
+	asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
+
+	/* enable rx */
+	__raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
+
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(new))
+		tty_termios_encode_baud_rate(new, baud, baud);
+
+	uart_update_timeout(port, cflag, baud);
+}
+
+static const char*
+lqasc_type(struct uart_port *port)
+{
+	if (port->type == PORT_LTQ_ASC)
+		return DRVNAME;
+	else
+		return NULL;
+}
+
+static void
+lqasc_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+
+	if (port->flags & UPF_IOREMAP) {
+		devm_iounmap(&pdev->dev, port->membase);
+		port->membase = NULL;
+	}
+}
+
+static int
+lqasc_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res;
+	int size;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot obtain I/O memory region");
+		return -ENODEV;
+	}
+	size = resource_size(res);
+
+	res = devm_request_mem_region(&pdev->dev, res->start,
+		size, dev_name(&pdev->dev));
+	if (!res) {
+		dev_err(&pdev->dev, "cannot request I/O memory region");
+		return -EBUSY;
+	}
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = devm_ioremap(&pdev->dev,
+			port->mapbase, size);
+		if (port->membase == NULL)
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+static void
+lqasc_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_LTQ_ASC;
+		lqasc_request_port(port);
+	}
+}
+
+static int
+lqasc_verify_port(struct uart_port *port,
+	struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
+		ret = -EINVAL;
+	if (ser->irq < 0 || ser->irq >= NR_IRQS)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops lqasc_pops = {
+	.tx_empty =	lqasc_tx_empty,
+	.set_mctrl =	lqasc_set_mctrl,
+	.get_mctrl =	lqasc_get_mctrl,
+	.stop_tx =	lqasc_stop_tx,
+	.start_tx =	lqasc_start_tx,
+	.stop_rx =	lqasc_stop_rx,
+	.break_ctl =	lqasc_break_ctl,
+	.startup =	lqasc_startup,
+	.shutdown =	lqasc_shutdown,
+	.set_termios =	lqasc_set_termios,
+	.type =		lqasc_type,
+	.release_port =	lqasc_release_port,
+	.request_port =	lqasc_request_port,
+	.config_port =	lqasc_config_port,
+	.verify_port =	lqasc_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
+static void
+lqasc_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	if (!port->membase)
+		return;
+
+	while (!lqasc_tx_ready(port))
+		;
+
+	writeb(ch, port->membase + LTQ_ASC_TBUF);
+}
+
+static void lqasc_serial_port_write(struct uart_port *port, const char *s,
+				    u_int count)
+{
+	uart_console_write(port, s, count, lqasc_console_putchar);
+}
+
+static void
+lqasc_console_write(struct console *co, const char *s, u_int count)
+{
+	struct ltq_uart_port *ltq_port;
+	unsigned long flags;
+
+	if (co->index >= MAXPORTS)
+		return;
+
+	ltq_port = lqasc_port[co->index];
+	if (!ltq_port)
+		return;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	lqasc_serial_port_write(&ltq_port->port, s, count);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+}
+
+static int __init
+lqasc_console_setup(struct console *co, char *options)
+{
+	struct ltq_uart_port *ltq_port;
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= MAXPORTS)
+		return -ENODEV;
+
+	ltq_port = lqasc_port[co->index];
+	if (!ltq_port)
+		return -ENODEV;
+
+	port = &ltq_port->port;
+
+	if (!IS_ERR(ltq_port->clk))
+		clk_prepare_enable(ltq_port->clk);
+
+	port->uartclk = clk_get_rate(ltq_port->freqclk);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console lqasc_console = {
+	.name =		"ttyLTQ",
+	.write =	lqasc_console_write,
+	.device =	uart_console_device,
+	.setup =	lqasc_console_setup,
+	.flags =	CON_PRINTBUFFER,
+	.index =	-1,
+	.data =		&lqasc_reg,
+};
+
+static int __init
+lqasc_console_init(void)
+{
+	register_console(&lqasc_console);
+	return 0;
+}
+console_initcall(lqasc_console_init);
+
+static void lqasc_serial_early_console_write(struct console *co,
+					     const char *s,
+					     u_int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	lqasc_serial_port_write(&dev->port, s, count);
+}
+
+static int __init
+lqasc_serial_early_console_setup(struct earlycon_device *device,
+				 const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = lqasc_serial_early_console_write;
+	return 0;
+}
+OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
+OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
+
+#define LANTIQ_SERIAL_CONSOLE	(&lqasc_console)
+
+#else
+
+#define LANTIQ_SERIAL_CONSOLE	NULL
+
+#endif /* CONFIG_SERIAL_LANTIQ_CONSOLE */
+
+static struct uart_driver lqasc_reg = {
+	.owner =	THIS_MODULE,
+	.driver_name =	DRVNAME,
+	.dev_name =	"ttyLTQ",
+	.major =	0,
+	.minor =	0,
+	.nr =		MAXPORTS,
+	.cons =		LANTIQ_SERIAL_CONSOLE,
+};
+
+static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
+{
+	struct uart_port *port = &ltq_port->port;
+	struct platform_device *pdev = to_platform_device(dev);
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	ltq_port->tx_irq = irq;
+	irq = platform_get_irq(pdev, 1);
+	if (irq < 0)
+		return irq;
+	ltq_port->rx_irq = irq;
+	irq = platform_get_irq(pdev, 2);
+	if (irq < 0)
+		return irq;
+	ltq_port->err_irq = irq;
+
+	port->irq = ltq_port->tx_irq;
+
+	return 0;
+}
+
+static int request_irq_lantiq(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	int retval;
+
+	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
+			     0, "asc_tx", port);
+	if (retval) {
+		dev_err(port->dev, "failed to request asc_tx\n");
+		return retval;
+	}
+
+	retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
+			     0, "asc_rx", port);
+	if (retval) {
+		dev_err(port->dev, "failed to request asc_rx\n");
+		goto err1;
+	}
+
+	retval = request_irq(ltq_port->err_irq, lqasc_err_int,
+			     0, "asc_err", port);
+	if (retval) {
+		dev_err(port->dev, "failed to request asc_err\n");
+		goto err2;
+	}
+	return 0;
+
+err2:
+	free_irq(ltq_port->rx_irq, port);
+err1:
+	free_irq(ltq_port->tx_irq, port);
+	return retval;
+}
+
+static void free_irq_lantiq(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	free_irq(ltq_port->tx_irq, port);
+	free_irq(ltq_port->rx_irq, port);
+	free_irq(ltq_port->err_irq, port);
+}
+
+static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
+{
+	struct uart_port *port = &ltq_port->port;
+	int ret;
+
+	ret = platform_get_irq(to_platform_device(dev), 0);
+	if (ret < 0) {
+		dev_err(dev, "failed to fetch IRQ for serial port\n");
+		return ret;
+	}
+	ltq_port->common_irq = ret;
+	port->irq = ret;
+
+	return 0;
+}
+
+static int request_irq_intel(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	int retval;
+
+	retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
+			     "asc_irq", port);
+	if (retval)
+		dev_err(port->dev, "failed to request asc_irq\n");
+
+	return retval;
+}
+
+static void free_irq_intel(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	free_irq(ltq_port->common_irq, port);
+}
+
+static int lqasc_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct ltq_uart_port *ltq_port;
+	struct uart_port *port;
+	struct resource *mmres;
+	int line;
+	int ret;
+
+	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mmres) {
+		dev_err(&pdev->dev,
+			"failed to get memory for serial port\n");
+		return -ENODEV;
+	}
+
+	ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
+				GFP_KERNEL);
+	if (!ltq_port)
+		return -ENOMEM;
+
+	port = &ltq_port->port;
+
+	ltq_port->soc = of_device_get_match_data(&pdev->dev);
+	ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
+	if (ret)
+		return ret;
+
+	/* get serial id */
+	line = of_alias_get_id(node, "serial");
+	if (line < 0) {
+		if (IS_ENABLED(CONFIG_LANTIQ)) {
+			if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
+				line = 0;
+			else
+				line = 1;
+		} else {
+			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
+				line);
+			return line;
+		}
+	}
+
+	if (lqasc_port[line]) {
+		dev_err(&pdev->dev, "port %d already allocated\n", line);
+		return -EBUSY;
+	}
+
+	port->iotype	= SERIAL_IO_MEM;
+	port->flags	= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+	port->ops	= &lqasc_pops;
+	port->fifosize	= 16;
+	port->type	= PORT_LTQ_ASC;
+	port->line	= line;
+	port->dev	= &pdev->dev;
+	/* unused, just to be backward-compatible */
+	port->mapbase	= mmres->start;
+
+	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
+		ltq_port->freqclk = clk_get_fpi();
+	else
+		ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
+
+
+	if (IS_ERR(ltq_port->freqclk)) {
+		pr_err("failed to get fpi clk\n");
+		return -ENOENT;
+	}
+
+	/* not all asc ports have clock gates, lets ignore the return code */
+	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
+		ltq_port->clk = clk_get(&pdev->dev, NULL);
+	else
+		ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
+
+	spin_lock_init(&ltq_port->lock);
+	lqasc_port[line] = ltq_port;
+	platform_set_drvdata(pdev, ltq_port);
+
+	ret = uart_add_one_port(&lqasc_reg, port);
+
+	return ret;
+}
+
+static int lqasc_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&lqasc_reg, port);
+
+	return 0;
+}
+
+static const struct ltq_soc_data soc_data_lantiq = {
+	.fetch_irq = fetch_irq_lantiq,
+	.request_irq = request_irq_lantiq,
+	.free_irq = free_irq_lantiq,
+};
+
+static const struct ltq_soc_data soc_data_intel = {
+	.fetch_irq = fetch_irq_intel,
+	.request_irq = request_irq_intel,
+	.free_irq = free_irq_intel,
+};
+
+static const struct of_device_id ltq_asc_match[] = {
+	{ .compatible = "lantiq,asc", .data = &soc_data_lantiq },
+	{ .compatible = "intel,lgm-asc", .data = &soc_data_intel },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ltq_asc_match);
+
+static struct platform_driver lqasc_driver = {
+	.probe		= lqasc_probe,
+	.remove		= lqasc_remove,
+	.driver		= {
+		.name	= DRVNAME,
+		.of_match_table = ltq_asc_match,
+	},
+};
+
+static int __init
+init_lqasc(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&lqasc_reg);
+	if (ret != 0)
+		return ret;
+
+	ret = platform_driver_register(&lqasc_driver);
+	if (ret != 0)
+		uart_unregister_driver(&lqasc_reg);
+
+	return ret;
+}
+
+static void __exit exit_lqasc(void)
+{
+	platform_driver_unregister(&lqasc_driver);
+	uart_unregister_driver(&lqasc_reg);
+}
+
+module_init(init_lqasc);
+module_exit(exit_lqasc);
+
+MODULE_DESCRIPTION("Serial driver for Lantiq & Intel gateway SoCs");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c
new file mode 100644
index 000000000..d881cdd2a
--- /dev/null
+++ b/drivers/tty/serial/liteuart.c
@@ -0,0 +1,480 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * LiteUART serial controller (LiteX) Driver
+ *
+ * Copyright (C) 2019-2020 Antmicro <www.antmicro.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/litex.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/tty_flip.h>
+#include <linux/xarray.h>
+
+/*
+ * CSRs definitions (base address offsets + width)
+ *
+ * The definitions below are true for LiteX SoC configured for 8-bit CSR Bus,
+ * 32-bit aligned.
+ *
+ * Supporting other configurations might require new definitions or a more
+ * generic way of indexing the LiteX CSRs.
+ *
+ * For more details on how CSRs are defined and handled in LiteX, see comments
+ * in the LiteX SoC Driver: drivers/soc/litex/litex_soc_ctrl.c
+ */
+#define OFF_RXTX	0x00
+#define OFF_TXFULL	0x04
+#define OFF_RXEMPTY	0x08
+#define OFF_EV_STATUS	0x0c
+#define OFF_EV_PENDING	0x10
+#define OFF_EV_ENABLE	0x14
+
+/* events */
+#define EV_TX		BIT(0)
+#define EV_RX		BIT(1)
+
+struct liteuart_port {
+	struct uart_port port;
+	struct timer_list timer;
+	u8 irq_reg;
+};
+
+#define to_liteuart_port(port)	container_of(port, struct liteuart_port, port)
+
+static DEFINE_XARRAY_FLAGS(liteuart_array, XA_FLAGS_ALLOC);
+
+#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
+static struct console liteuart_console;
+#endif
+
+static struct uart_driver liteuart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = KBUILD_MODNAME,
+	.dev_name = "ttyLXU",
+	.major = 0,
+	.minor = 0,
+	.nr = CONFIG_SERIAL_LITEUART_MAX_PORTS,
+#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
+	.cons = &liteuart_console,
+#endif
+};
+
+static void liteuart_update_irq_reg(struct uart_port *port, bool set, u8 mask)
+{
+	struct liteuart_port *uart = to_liteuart_port(port);
+
+	if (set)
+		uart->irq_reg |= mask;
+	else
+		uart->irq_reg &= ~mask;
+
+	if (port->irq)
+		litex_write8(port->membase + OFF_EV_ENABLE, uart->irq_reg);
+}
+
+static void liteuart_stop_tx(struct uart_port *port)
+{
+	liteuart_update_irq_reg(port, false, EV_TX);
+}
+
+static void liteuart_start_tx(struct uart_port *port)
+{
+	liteuart_update_irq_reg(port, true, EV_TX);
+}
+
+static void liteuart_stop_rx(struct uart_port *port)
+{
+	struct liteuart_port *uart = to_liteuart_port(port);
+
+	/* just delete timer */
+	del_timer(&uart->timer);
+}
+
+static void liteuart_rx_chars(struct uart_port *port)
+{
+	unsigned char __iomem *membase = port->membase;
+	u8 ch;
+
+	while (!litex_read8(membase + OFF_RXEMPTY)) {
+		ch = litex_read8(membase + OFF_RXTX);
+		port->icount.rx++;
+
+		/* necessary for RXEMPTY to refresh its value */
+		litex_write8(membase + OFF_EV_PENDING, EV_RX);
+
+		/* no overflow bits in status */
+		if (!(uart_handle_sysrq_char(port, ch)))
+			uart_insert_char(port, 1, 0, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void liteuart_tx_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		!litex_read8(port->membase + OFF_TXFULL),
+		litex_write8(port->membase + OFF_RXTX, ch));
+}
+
+static irqreturn_t liteuart_interrupt(int irq, void *data)
+{
+	struct liteuart_port *uart = data;
+	struct uart_port *port = &uart->port;
+	unsigned long flags;
+	u8 isr;
+
+	/*
+	 * if polling, the context would be "in_serving_softirq", so use
+	 * irq[save|restore] spin_lock variants to cover all possibilities
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+	isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg;
+	if (isr & EV_RX)
+		liteuart_rx_chars(port);
+	if (isr & EV_TX)
+		liteuart_tx_chars(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_RETVAL(isr);
+}
+
+static void liteuart_timer(struct timer_list *t)
+{
+	struct liteuart_port *uart = from_timer(uart, t, timer);
+	struct uart_port *port = &uart->port;
+
+	liteuart_interrupt(0, port);
+	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
+}
+
+static unsigned int liteuart_tx_empty(struct uart_port *port)
+{
+	/* not really tx empty, just checking if tx is not full */
+	if (!litex_read8(port->membase + OFF_TXFULL))
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static void liteuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* modem control register is not present in LiteUART */
+}
+
+static unsigned int liteuart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static int liteuart_startup(struct uart_port *port)
+{
+	struct liteuart_port *uart = to_liteuart_port(port);
+	unsigned long flags;
+	int ret;
+
+	if (port->irq) {
+		ret = request_irq(port->irq, liteuart_interrupt, 0,
+				  KBUILD_MODNAME, uart);
+		if (ret) {
+			dev_warn(port->dev,
+				"line %d irq %d failed: switch to polling\n",
+				port->line, port->irq);
+			port->irq = 0;
+		}
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+	/* only enabling rx irqs during startup */
+	liteuart_update_irq_reg(port, true, EV_RX);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (!port->irq) {
+		timer_setup(&uart->timer, liteuart_timer, 0);
+		mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
+	}
+
+	return 0;
+}
+
+static void liteuart_shutdown(struct uart_port *port)
+{
+	struct liteuart_port *uart = to_liteuart_port(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	liteuart_update_irq_reg(port, false, EV_RX | EV_TX);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (port->irq)
+		free_irq(port->irq, port);
+	else
+		del_timer_sync(&uart->timer);
+}
+
+static void liteuart_set_termios(struct uart_port *port, struct ktermios *new,
+				 const struct ktermios *old)
+{
+	unsigned int baud;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* update baudrate */
+	baud = uart_get_baud_rate(port, new, old, 0, 460800);
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *liteuart_type(struct uart_port *port)
+{
+	return "liteuart";
+}
+
+static void liteuart_config_port(struct uart_port *port, int flags)
+{
+	/*
+	 * Driver core for serial ports forces a non-zero value for port type.
+	 * Write an arbitrary value here to accommodate the serial core driver,
+	 * as ID part of UAPI is redundant.
+	 */
+	port->type = 1;
+}
+
+static int liteuart_verify_port(struct uart_port *port,
+				struct serial_struct *ser)
+{
+	if (port->type != PORT_UNKNOWN && ser->type != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops liteuart_ops = {
+	.tx_empty	= liteuart_tx_empty,
+	.set_mctrl	= liteuart_set_mctrl,
+	.get_mctrl	= liteuart_get_mctrl,
+	.stop_tx	= liteuart_stop_tx,
+	.start_tx	= liteuart_start_tx,
+	.stop_rx	= liteuart_stop_rx,
+	.startup	= liteuart_startup,
+	.shutdown	= liteuart_shutdown,
+	.set_termios	= liteuart_set_termios,
+	.type		= liteuart_type,
+	.config_port	= liteuart_config_port,
+	.verify_port	= liteuart_verify_port,
+};
+
+static int liteuart_probe(struct platform_device *pdev)
+{
+	struct liteuart_port *uart;
+	struct uart_port *port;
+	struct xa_limit limit;
+	int dev_id, ret;
+
+	uart = devm_kzalloc(&pdev->dev, sizeof(struct liteuart_port), GFP_KERNEL);
+	if (!uart)
+		return -ENOMEM;
+
+	port = &uart->port;
+
+	/* get membase */
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+
+	ret = platform_get_irq_optional(pdev, 0);
+	if (ret < 0 && ret != -ENXIO)
+		return ret;
+	if (ret > 0)
+		port->irq = ret;
+
+	/* look for aliases; auto-enumerate for free index if not found */
+	dev_id = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (dev_id < 0)
+		limit = XA_LIMIT(0, CONFIG_SERIAL_LITEUART_MAX_PORTS);
+	else
+		limit = XA_LIMIT(dev_id, dev_id);
+
+	ret = xa_alloc(&liteuart_array, &dev_id, uart, limit, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	/* values not from device tree */
+	port->dev = &pdev->dev;
+	port->iotype = UPIO_MEM;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->ops = &liteuart_ops;
+	port->fifosize = 16;
+	port->type = PORT_UNKNOWN;
+	port->line = dev_id;
+	spin_lock_init(&port->lock);
+
+	platform_set_drvdata(pdev, port);
+
+	ret = uart_add_one_port(&liteuart_driver, &uart->port);
+	if (ret)
+		goto err_erase_id;
+
+	return 0;
+
+err_erase_id:
+	xa_erase(&liteuart_array, dev_id);
+
+	return ret;
+}
+
+static int liteuart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+	unsigned int line = port->line;
+
+	uart_remove_one_port(&liteuart_driver, port);
+	xa_erase(&liteuart_array, line);
+
+	return 0;
+}
+
+static const struct of_device_id liteuart_of_match[] = {
+	{ .compatible = "litex,liteuart" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, liteuart_of_match);
+
+static struct platform_driver liteuart_platform_driver = {
+	.probe = liteuart_probe,
+	.remove = liteuart_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = liteuart_of_match,
+	},
+};
+
+#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
+
+static void liteuart_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (litex_read8(port->membase + OFF_TXFULL))
+		cpu_relax();
+
+	litex_write8(port->membase + OFF_RXTX, ch);
+}
+
+static void liteuart_console_write(struct console *co, const char *s,
+	unsigned int count)
+{
+	struct liteuart_port *uart;
+	struct uart_port *port;
+	unsigned long flags;
+
+	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
+	port = &uart->port;
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_console_write(port, s, count, liteuart_putchar);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int liteuart_console_setup(struct console *co, char *options)
+{
+	struct liteuart_port *uart;
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
+	if (!uart)
+		return -ENODEV;
+
+	port = &uart->port;
+	if (!port->membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console liteuart_console = {
+	.name = KBUILD_MODNAME,
+	.write = liteuart_console_write,
+	.device = uart_console_device,
+	.setup = liteuart_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &liteuart_driver,
+};
+
+static int __init liteuart_console_init(void)
+{
+	register_console(&liteuart_console);
+
+	return 0;
+}
+console_initcall(liteuart_console_init);
+
+static void early_liteuart_write(struct console *console, const char *s,
+				    unsigned int count)
+{
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+
+	uart_console_write(port, s, count, liteuart_putchar);
+}
+
+static int __init early_liteuart_setup(struct earlycon_device *device,
+				       const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = early_liteuart_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(liteuart, "litex,liteuart", early_liteuart_setup);
+#endif /* CONFIG_SERIAL_LITEUART_CONSOLE */
+
+static int __init liteuart_init(void)
+{
+	int res;
+
+	res = uart_register_driver(&liteuart_driver);
+	if (res)
+		return res;
+
+	res = platform_driver_register(&liteuart_platform_driver);
+	if (res)
+		uart_unregister_driver(&liteuart_driver);
+
+	return res;
+}
+
+static void __exit liteuart_exit(void)
+{
+	platform_driver_unregister(&liteuart_platform_driver);
+	uart_unregister_driver(&liteuart_driver);
+}
+
+module_init(liteuart_init);
+module_exit(liteuart_exit);
+
+MODULE_AUTHOR("Antmicro <www.antmicro.com>");
+MODULE_DESCRIPTION("LiteUART serial driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:liteuart");
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c
new file mode 100644
index 000000000..b38fe4728
--- /dev/null
+++ b/drivers/tty/serial/lpc32xx_hs.c
@@ -0,0 +1,741 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * High Speed Serial Ports on NXP LPC32xx SoC
+ *
+ * Authors: Kevin Wells <kevin.wells@nxp.com>
+ *          Roland Stigge <stigge@antcom.de>
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ * Copyright (C) 2012 Roland Stigge
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/nmi.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/sizes.h>
+#include <linux/soc/nxp/lpc32xx-misc.h>
+
+/*
+ * High Speed UART register offsets
+ */
+#define LPC32XX_HSUART_FIFO(x)			((x) + 0x00)
+#define LPC32XX_HSUART_LEVEL(x)			((x) + 0x04)
+#define LPC32XX_HSUART_IIR(x)			((x) + 0x08)
+#define LPC32XX_HSUART_CTRL(x)			((x) + 0x0C)
+#define LPC32XX_HSUART_RATE(x)			((x) + 0x10)
+
+#define LPC32XX_HSU_BREAK_DATA			(1 << 10)
+#define LPC32XX_HSU_ERROR_DATA			(1 << 9)
+#define LPC32XX_HSU_RX_EMPTY			(1 << 8)
+
+#define LPC32XX_HSU_TX_LEV(n)			(((n) >> 8) & 0xFF)
+#define LPC32XX_HSU_RX_LEV(n)			((n) & 0xFF)
+
+#define LPC32XX_HSU_TX_INT_SET			(1 << 6)
+#define LPC32XX_HSU_RX_OE_INT			(1 << 5)
+#define LPC32XX_HSU_BRK_INT			(1 << 4)
+#define LPC32XX_HSU_FE_INT			(1 << 3)
+#define LPC32XX_HSU_RX_TIMEOUT_INT		(1 << 2)
+#define LPC32XX_HSU_RX_TRIG_INT			(1 << 1)
+#define LPC32XX_HSU_TX_INT			(1 << 0)
+
+#define LPC32XX_HSU_HRTS_INV			(1 << 21)
+#define LPC32XX_HSU_HRTS_TRIG_8B		(0x0 << 19)
+#define LPC32XX_HSU_HRTS_TRIG_16B		(0x1 << 19)
+#define LPC32XX_HSU_HRTS_TRIG_32B		(0x2 << 19)
+#define LPC32XX_HSU_HRTS_TRIG_48B		(0x3 << 19)
+#define LPC32XX_HSU_HRTS_EN			(1 << 18)
+#define LPC32XX_HSU_TMO_DISABLED		(0x0 << 16)
+#define LPC32XX_HSU_TMO_INACT_4B		(0x1 << 16)
+#define LPC32XX_HSU_TMO_INACT_8B		(0x2 << 16)
+#define LPC32XX_HSU_TMO_INACT_16B		(0x3 << 16)
+#define LPC32XX_HSU_HCTS_INV			(1 << 15)
+#define LPC32XX_HSU_HCTS_EN			(1 << 14)
+#define LPC32XX_HSU_OFFSET(n)			((n) << 9)
+#define LPC32XX_HSU_BREAK			(1 << 8)
+#define LPC32XX_HSU_ERR_INT_EN			(1 << 7)
+#define LPC32XX_HSU_RX_INT_EN			(1 << 6)
+#define LPC32XX_HSU_TX_INT_EN			(1 << 5)
+#define LPC32XX_HSU_RX_TL1B			(0x0 << 2)
+#define LPC32XX_HSU_RX_TL4B			(0x1 << 2)
+#define LPC32XX_HSU_RX_TL8B			(0x2 << 2)
+#define LPC32XX_HSU_RX_TL16B			(0x3 << 2)
+#define LPC32XX_HSU_RX_TL32B			(0x4 << 2)
+#define LPC32XX_HSU_RX_TL48B			(0x5 << 2)
+#define LPC32XX_HSU_TX_TLEMPTY			(0x0 << 0)
+#define LPC32XX_HSU_TX_TL0B			(0x0 << 0)
+#define LPC32XX_HSU_TX_TL4B			(0x1 << 0)
+#define LPC32XX_HSU_TX_TL8B			(0x2 << 0)
+#define LPC32XX_HSU_TX_TL16B			(0x3 << 0)
+
+#define LPC32XX_MAIN_OSC_FREQ			13000000
+
+#define MODNAME "lpc32xx_hsuart"
+
+struct lpc32xx_hsuart_port {
+	struct uart_port port;
+};
+
+#define FIFO_READ_LIMIT 128
+#define MAX_PORTS 3
+#define LPC32XX_TTY_NAME "ttyTX"
+static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
+
+#ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
+static void wait_for_xmit_empty(struct uart_port *port)
+{
+	unsigned int timeout = 10000;
+
+	do {
+		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
+							port->membase))) == 0)
+			break;
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	} while (1);
+}
+
+static void wait_for_xmit_ready(struct uart_port *port)
+{
+	unsigned int timeout = 10000;
+
+	while (1) {
+		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
+							port->membase))) < 32)
+			break;
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	}
+}
+
+static void lpc32xx_hsuart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	wait_for_xmit_ready(port);
+	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
+}
+
+static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
+					 unsigned int count)
+{
+	struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
+	unsigned long flags;
+	int locked = 1;
+
+	touch_nmi_watchdog();
+	local_irq_save(flags);
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&up->port.lock);
+	else
+		spin_lock(&up->port.lock);
+
+	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
+	wait_for_xmit_empty(&up->port);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+	local_irq_restore(flags);
+}
+
+static int __init lpc32xx_hsuart_console_setup(struct console *co,
+					       char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= MAX_PORTS)
+		co->index = 0;
+
+	port = &lpc32xx_hs_ports[co->index].port;
+	if (!port->membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver lpc32xx_hsuart_reg;
+static struct console lpc32xx_hsuart_console = {
+	.name		= LPC32XX_TTY_NAME,
+	.write		= lpc32xx_hsuart_console_write,
+	.device		= uart_console_device,
+	.setup		= lpc32xx_hsuart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &lpc32xx_hsuart_reg,
+};
+
+static int __init lpc32xx_hsuart_console_init(void)
+{
+	register_console(&lpc32xx_hsuart_console);
+	return 0;
+}
+console_initcall(lpc32xx_hsuart_console_init);
+
+#define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
+#else
+#define LPC32XX_HSUART_CONSOLE NULL
+#endif
+
+static struct uart_driver lpc32xx_hs_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= MODNAME,
+	.dev_name	= LPC32XX_TTY_NAME,
+	.nr		= MAX_PORTS,
+	.cons		= LPC32XX_HSUART_CONSOLE,
+};
+static int uarts_registered;
+
+static unsigned int __serial_get_clock_div(unsigned long uartclk,
+					   unsigned long rate)
+{
+	u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
+	u32 rate_diff;
+
+	/* Find the closest divider to get the desired clock rate */
+	div = uartclk / rate;
+	goodrate = hsu_rate = (div / 14) - 1;
+	if (hsu_rate != 0)
+		hsu_rate--;
+
+	/* Tweak divider */
+	l_hsu_rate = hsu_rate + 3;
+	rate_diff = 0xFFFFFFFF;
+
+	while (hsu_rate < l_hsu_rate) {
+		comprate = uartclk / ((hsu_rate + 1) * 14);
+		if (abs(comprate - rate) < rate_diff) {
+			goodrate = hsu_rate;
+			rate_diff = abs(comprate - rate);
+		}
+
+		hsu_rate++;
+	}
+	if (hsu_rate > 0xFF)
+		hsu_rate = 0xFF;
+
+	return goodrate;
+}
+
+static void __serial_uart_flush(struct uart_port *port)
+{
+	int cnt = 0;
+
+	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
+	       (cnt++ < FIFO_READ_LIMIT))
+		readl(LPC32XX_HSUART_FIFO(port->membase));
+}
+
+static void __serial_lpc32xx_rx(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned int tmp, flag;
+
+	/* Read data from FIFO and push into terminal */
+	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
+	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (tmp & LPC32XX_HSU_ERROR_DATA) {
+			/* Framing error */
+			writel(LPC32XX_HSU_FE_INT,
+			       LPC32XX_HSUART_IIR(port->membase));
+			port->icount.frame++;
+			flag = TTY_FRAME;
+			tty_insert_flip_char(tport, 0, TTY_FRAME);
+		}
+
+		tty_insert_flip_char(tport, (tmp & 0xFF), flag);
+
+		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
+	}
+
+	tty_flip_buffer_push(tport);
+}
+
+static bool serial_lpc32xx_tx_ready(struct uart_port *port)
+{
+	u32 level = readl(LPC32XX_HSUART_LEVEL(port->membase));
+
+	return LPC32XX_HSU_TX_LEV(level) < 64;
+}
+
+static void __serial_lpc32xx_tx(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		serial_lpc32xx_tx_ready(port),
+		writel(ch, LPC32XX_HSUART_FIFO(port->membase)));
+}
+
+static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct tty_port *tport = &port->state->port;
+	u32 status;
+
+	spin_lock(&port->lock);
+
+	/* Read UART status and clear latched interrupts */
+	status = readl(LPC32XX_HSUART_IIR(port->membase));
+
+	if (status & LPC32XX_HSU_BRK_INT) {
+		/* Break received */
+		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
+		port->icount.brk++;
+		uart_handle_break(port);
+	}
+
+	/* Framing error */
+	if (status & LPC32XX_HSU_FE_INT)
+		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
+
+	if (status & LPC32XX_HSU_RX_OE_INT) {
+		/* Receive FIFO overrun */
+		writel(LPC32XX_HSU_RX_OE_INT,
+		       LPC32XX_HSUART_IIR(port->membase));
+		port->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+		tty_flip_buffer_push(tport);
+	}
+
+	/* Data received? */
+	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
+		__serial_lpc32xx_rx(port);
+
+	/* Transmit data request? */
+	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
+		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
+		__serial_lpc32xx_tx(port);
+	}
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+/* port->lock is not held.  */
+static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
+{
+	unsigned int ret = 0;
+
+	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
+		ret = TIOCSER_TEMT;
+
+	return ret;
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_set_mctrl(struct uart_port *port,
+				     unsigned int mctrl)
+{
+	/* No signals are supported on HS UARTs */
+}
+
+/* port->lock is held by caller and interrupts are disabled.  */
+static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
+{
+	/* No signals are supported on HS UARTs */
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_stop_tx(struct uart_port *port)
+{
+	u32 tmp;
+
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	tmp &= ~LPC32XX_HSU_TX_INT_EN;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_start_tx(struct uart_port *port)
+{
+	u32 tmp;
+
+	__serial_lpc32xx_tx(port);
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	tmp |= LPC32XX_HSU_TX_INT_EN;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_stop_rx(struct uart_port *port)
+{
+	u32 tmp;
+
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
+		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
+}
+
+/* port->lock is not held.  */
+static void serial_lpc32xx_break_ctl(struct uart_port *port,
+				     int break_state)
+{
+	unsigned long flags;
+	u32 tmp;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	if (break_state != 0)
+		tmp |= LPC32XX_HSU_BREAK;
+	else
+		tmp &= ~LPC32XX_HSU_BREAK;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* port->lock is not held.  */
+static int serial_lpc32xx_startup(struct uart_port *port)
+{
+	int retval;
+	unsigned long flags;
+	u32 tmp;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	__serial_uart_flush(port);
+
+	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
+		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
+	       LPC32XX_HSUART_IIR(port->membase));
+
+	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
+
+	/*
+	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
+	 * and default FIFO trigger levels
+	 */
+	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
+			     0, MODNAME, port);
+	if (!retval)
+		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
+		       LPC32XX_HSUART_CTRL(port->membase));
+
+	return retval;
+}
+
+/* port->lock is not held.  */
+static void serial_lpc32xx_shutdown(struct uart_port *port)
+{
+	u32 tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+/* port->lock is not held.  */
+static void serial_lpc32xx_set_termios(struct uart_port *port,
+				       struct ktermios *termios,
+				       const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, quot;
+	u32 tmp;
+
+	/* Always 8-bit, no parity, 1 stop bit */
+	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
+	termios->c_cflag |= CS8;
+
+	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
+
+	baud = uart_get_baud_rate(port, termios, old, 0,
+				  port->uartclk / 14);
+
+	quot = __serial_get_clock_div(port->uartclk, baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Ignore characters? */
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	if ((termios->c_cflag & CREAD) == 0)
+		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
+	else
+		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	writel(quot, LPC32XX_HSUART_RATE(port->membase));
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *serial_lpc32xx_type(struct uart_port *port)
+{
+	return MODNAME;
+}
+
+static void serial_lpc32xx_release_port(struct uart_port *port)
+{
+	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
+		if (port->flags & UPF_IOREMAP) {
+			iounmap(port->membase);
+			port->membase = NULL;
+		}
+
+		release_mem_region(port->mapbase, SZ_4K);
+	}
+}
+
+static int serial_lpc32xx_request_port(struct uart_port *port)
+{
+	int ret = -ENODEV;
+
+	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
+		ret = 0;
+
+		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
+			ret = -EBUSY;
+		else if (port->flags & UPF_IOREMAP) {
+			port->membase = ioremap(port->mapbase, SZ_4K);
+			if (!port->membase) {
+				release_mem_region(port->mapbase, SZ_4K);
+				ret = -ENOMEM;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
+{
+	int ret;
+
+	ret = serial_lpc32xx_request_port(port);
+	if (ret < 0)
+		return;
+	port->type = PORT_UART00;
+	port->fifosize = 64;
+
+	__serial_uart_flush(port);
+
+	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
+		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
+	       LPC32XX_HSUART_IIR(port->membase));
+
+	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
+
+	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
+	   and default FIFO trigger levels */
+	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
+	       LPC32XX_HSUART_CTRL(port->membase));
+}
+
+static int serial_lpc32xx_verify_port(struct uart_port *port,
+				      struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UART00)
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static const struct uart_ops serial_lpc32xx_pops = {
+	.tx_empty	= serial_lpc32xx_tx_empty,
+	.set_mctrl	= serial_lpc32xx_set_mctrl,
+	.get_mctrl	= serial_lpc32xx_get_mctrl,
+	.stop_tx	= serial_lpc32xx_stop_tx,
+	.start_tx	= serial_lpc32xx_start_tx,
+	.stop_rx	= serial_lpc32xx_stop_rx,
+	.break_ctl	= serial_lpc32xx_break_ctl,
+	.startup	= serial_lpc32xx_startup,
+	.shutdown	= serial_lpc32xx_shutdown,
+	.set_termios	= serial_lpc32xx_set_termios,
+	.type		= serial_lpc32xx_type,
+	.release_port	= serial_lpc32xx_release_port,
+	.request_port	= serial_lpc32xx_request_port,
+	.config_port	= serial_lpc32xx_config_port,
+	.verify_port	= serial_lpc32xx_verify_port,
+};
+
+/*
+ * Register a set of serial devices attached to a platform device
+ */
+static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
+{
+	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
+	int ret = 0;
+	struct resource *res;
+
+	if (uarts_registered >= MAX_PORTS) {
+		dev_err(&pdev->dev,
+			"Error: Number of possible ports exceeded (%d)!\n",
+			uarts_registered + 1);
+		return -ENXIO;
+	}
+
+	memset(p, 0, sizeof(*p));
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev,
+			"Error getting mem resource for HS UART port %d\n",
+			uarts_registered);
+		return -ENXIO;
+	}
+	p->port.mapbase = res->start;
+	p->port.membase = NULL;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	p->port.irq = ret;
+
+	p->port.iotype = UPIO_MEM32;
+	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
+	p->port.regshift = 2;
+	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
+	p->port.dev = &pdev->dev;
+	p->port.ops = &serial_lpc32xx_pops;
+	p->port.line = uarts_registered++;
+	spin_lock_init(&p->port.lock);
+
+	/* send port to loopback mode by default */
+	lpc32xx_loopback_set(p->port.mapbase, 1);
+
+	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
+
+	platform_set_drvdata(pdev, p);
+
+	return ret;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
+{
+	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
+
+	return 0;
+}
+
+
+#ifdef CONFIG_PM
+static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
+				     pm_message_t state)
+{
+	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
+
+	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
+
+	return 0;
+}
+
+static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
+{
+	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
+
+	uart_resume_port(&lpc32xx_hs_reg, &p->port);
+
+	return 0;
+}
+#else
+#define serial_hs_lpc32xx_suspend	NULL
+#define serial_hs_lpc32xx_resume	NULL
+#endif
+
+static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
+	{ .compatible = "nxp,lpc3220-hsuart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
+
+static struct platform_driver serial_hs_lpc32xx_driver = {
+	.probe		= serial_hs_lpc32xx_probe,
+	.remove		= serial_hs_lpc32xx_remove,
+	.suspend	= serial_hs_lpc32xx_suspend,
+	.resume		= serial_hs_lpc32xx_resume,
+	.driver		= {
+		.name	= MODNAME,
+		.of_match_table	= serial_hs_lpc32xx_dt_ids,
+	},
+};
+
+static int __init lpc32xx_hsuart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&lpc32xx_hs_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
+	if (ret)
+		uart_unregister_driver(&lpc32xx_hs_reg);
+
+	return ret;
+}
+
+static void __exit lpc32xx_hsuart_exit(void)
+{
+	platform_driver_unregister(&serial_hs_lpc32xx_driver);
+	uart_unregister_driver(&lpc32xx_hs_reg);
+}
+
+module_init(lpc32xx_hsuart_init);
+module_exit(lpc32xx_hsuart_exit);
+
+MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c
new file mode 100644
index 000000000..69da24565
--- /dev/null
+++ b/drivers/tty/serial/ma35d1_serial.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  MA35D1 serial driver
+ *  Copyright (C) 2023 Nuvoton Technology Corp.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/iopoll.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/units.h>
+
+#define MA35_UART_NR		17
+
+#define MA35_RBR_REG		0x00
+#define MA35_THR_REG		0x00
+#define MA35_IER_REG		0x04
+#define MA35_FCR_REG		0x08
+#define MA35_LCR_REG		0x0C
+#define MA35_MCR_REG		0x10
+#define MA35_MSR_REG		0x14
+#define MA35_FSR_REG		0x18
+#define MA35_ISR_REG		0x1C
+#define MA35_TOR_REG		0x20
+#define MA35_BAUD_REG		0x24
+#define MA35_ALTCTL_REG		0x2C
+#define MA35_FUN_SEL_REG	0x30
+#define MA35_WKCTL_REG		0x40
+#define MA35_WKSTS_REG		0x44
+
+/* MA35_IER_REG - Interrupt Enable Register */
+#define MA35_IER_RDA_IEN	BIT(0)  /* RBR Available Interrupt Enable */
+#define MA35_IER_THRE_IEN	BIT(1)  /* THR Empty Interrupt Enable */
+#define MA35_IER_RLS_IEN	BIT(2)  /* RX Line Status Interrupt Enable */
+#define MA35_IER_RTO_IEN	BIT(4)  /* RX Time-out Interrupt Enable */
+#define MA35_IER_BUFERR_IEN	BIT(5)  /* Buffer Error Interrupt Enable */
+#define MA35_IER_TIME_OUT_EN	BIT(11) /* RX Buffer Time-out Counter Enable */
+#define MA35_IER_AUTO_RTS	BIT(12) /* nRTS Auto-flow Control Enable */
+#define MA35_IER_AUTO_CTS	BIT(13) /* nCTS Auto-flow Control Enable */
+
+/* MA35_FCR_REG - FIFO Control Register */
+#define MA35_FCR_RFR		BIT(1)  /* RX Field Software Reset */
+#define MA35_FCR_TFR		BIT(2)  /* TX Field Software Reset */
+#define MA35_FCR_RFITL_MASK	GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
+#define MA35_FCR_RFITL_1BYTE	FIELD_PREP(MA35_FCR_RFITL_MASK, 0)
+#define MA35_FCR_RFITL_4BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 1)
+#define MA35_FCR_RFITL_8BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 2)
+#define MA35_FCR_RFITL_14BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 3)
+#define MA35_FCR_RFITL_30BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 4)
+#define MA35_FCR_RTSTL_MASK	GENMASK(19, 16) /* nRTS Trigger Level */
+#define MA35_FCR_RTSTL_1BYTE	FIELD_PREP(MA35_FCR_RTSTL_MASK, 0)
+#define MA35_FCR_RTSTL_4BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 1)
+#define MA35_FCR_RTSTL_8BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 2)
+#define MA35_FCR_RTSTL_14BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 3)
+#define MA35_FCR_RTSTLL_30BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 4)
+
+/* MA35_LCR_REG - Line Control Register */
+#define	MA35_LCR_NSB		BIT(2)  /* Number of “STOP Bit” */
+#define MA35_LCR_PBE		BIT(3)  /* Parity Bit Enable */
+#define MA35_LCR_EPE		BIT(4)  /* Even Parity Enable */
+#define MA35_LCR_SPE		BIT(5)  /* Stick Parity Enable */
+#define MA35_LCR_BREAK		BIT(6)  /* Break Control */
+#define MA35_LCR_WLS_MASK	GENMASK(1, 0) /* Word Length Selection */
+#define MA35_LCR_WLS_5BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 0)
+#define MA35_LCR_WLS_6BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 1)
+#define MA35_LCR_WLS_7BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 2)
+#define MA35_LCR_WLS_8BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 3)
+
+/* MA35_MCR_REG - Modem Control Register */
+#define MA35_MCR_RTS_CTRL	BIT(1)  /* nRTS Signal Control */
+#define MA35_MCR_RTSACTLV	BIT(9)  /* nRTS Pin Active Level */
+#define MA35_MCR_RTSSTS		BIT(13) /* nRTS Pin Status (Read Only) */
+
+/* MA35_MSR_REG - Modem Status Register */
+#define MA35_MSR_CTSDETF	BIT(0)  /* Detect nCTS State Change Flag */
+#define MA35_MSR_CTSSTS		BIT(4)  /* nCTS Pin Status (Read Only) */
+#define MA35_MSR_CTSACTLV	BIT(8)  /* nCTS Pin Active Level */
+
+/* MA35_FSR_REG - FIFO Status Register */
+#define MA35_FSR_RX_OVER_IF	BIT(0)  /* RX Overflow Error Interrupt Flag */
+#define MA35_FSR_PEF		BIT(4)  /* Parity Error Flag*/
+#define MA35_FSR_FEF		BIT(5)  /* Framing Error Flag */
+#define MA35_FSR_BIF		BIT(6)  /* Break Interrupt Flag */
+#define MA35_FSR_RX_EMPTY	BIT(14) /* Receiver FIFO Empty (Read Only) */
+#define MA35_FSR_RX_FULL	BIT(15) /* Receiver FIFO Full (Read Only) */
+#define MA35_FSR_TX_EMPTY	BIT(22) /* Transmitter FIFO Empty (Read Only) */
+#define MA35_FSR_TX_FULL	BIT(23) /* Transmitter FIFO Full (Read Only) */
+#define MA35_FSR_TX_OVER_IF	BIT(24) /* TX Overflow Error Interrupt Flag */
+#define MA35_FSR_TE_FLAG	BIT(28) /* Transmitter Empty Flag (Read Only) */
+#define MA35_FSR_RXPTR_MSK	GENMASK(13, 8) /* TX FIFO Pointer mask */
+#define MA35_FSR_TXPTR_MSK	GENMASK(21, 16) /* RX FIFO Pointer mask */
+
+/* MA35_ISR_REG - Interrupt Status Register */
+#define MA35_ISR_RDA_IF		BIT(0)  /* RBR Available Interrupt Flag */
+#define MA35_ISR_THRE_IF	BIT(1)  /* THR Empty Interrupt Flag */
+#define MA35_ISR_RLSIF		BIT(2)  /* Receive Line Interrupt Flag */
+#define MA35_ISR_MODEMIF	BIT(3)  /* MODEM Interrupt Flag */
+#define MA35_ISR_RXTO_IF	BIT(4)  /* RX Time-out Interrupt Flag */
+#define MA35_ISR_BUFEIF		BIT(5)  /* Buffer Error Interrupt Flag */
+#define MA35_ISR_WK_IF		BIT(6)  /* UART Wake-up Interrupt Flag */
+#define MA35_ISR_RDAINT		BIT(8)  /* RBR Available Interrupt Indicator */
+#define MA35_ISR_THRE_INT	BIT(9)  /* THR Empty Interrupt Indicator */
+#define MA35_ISR_ALL		0xFFFFFFFF
+
+/* MA35_BAUD_REG - Baud Rate Divider Register */
+#define	MA35_BAUD_MODE_MASK	GENMASK(29, 28)
+#define MA35_BAUD_MODE0		FIELD_PREP(MA35_BAUD_MODE_MASK, 0)
+#define MA35_BAUD_MODE1		FIELD_PREP(MA35_BAUD_MODE_MASK, 2)
+#define MA35_BAUD_MODE2		FIELD_PREP(MA35_BAUD_MODE_MASK, 3)
+#define	MA35_BAUD_MASK		GENMASK(15, 0)
+
+/* MA35_ALTCTL_REG - Alternate Control/Status Register */
+#define MA35_ALTCTL_RS485AUD	BIT(10) /* RS-485 Auto Direction Function */
+
+/* MA35_FUN_SEL_REG - Function Select Register */
+#define MA35_FUN_SEL_MASK	GENMASK(2, 0)
+#define MA35_FUN_SEL_UART	FIELD_PREP(MA35_FUN_SEL_MASK, 0)
+#define MA35_FUN_SEL_RS485	FIELD_PREP(MA35_FUN_SEL_MASK, 3)
+
+/* The constrain for MA35D1 UART baud rate divider */
+#define MA35_BAUD_DIV_MAX	0xFFFF
+#define MA35_BAUD_DIV_MIN	11
+
+/* UART FIFO depth */
+#define MA35_UART_FIFO_DEPTH	32
+/* UART console clock */
+#define MA35_UART_CONSOLE_CLK	(24 * HZ_PER_MHZ)
+/* UART register ioremap size */
+#define MA35_UART_REG_SIZE	0x100
+/* Rx Timeout */
+#define MA35_UART_RX_TOUT	0x40
+
+#define MA35_IER_CONFIG		(MA35_IER_RTO_IEN | MA35_IER_RDA_IEN | \
+				 MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN)
+
+#define MA35_ISR_IF_CHECK	(MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF | \
+				 MA35_ISR_THRE_INT | MA35_ISR_BUFEIF)
+
+#define MA35_FSR_TX_BOTH_EMPTY	(MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)
+
+static struct uart_driver ma35d1serial_reg;
+
+struct uart_ma35d1_port {
+	struct uart_port port;
+	struct clk *clk;
+	u16 capabilities; /* port capabilities */
+	u8 ier;
+	u8 lcr;
+	u8 mcr;
+	u32 baud_rate;
+	u32 console_baud_rate;
+	u32 console_line;
+	u32 console_int;
+};
+
+static struct uart_ma35d1_port ma35d1serial_ports[MA35_UART_NR];
+
+static struct uart_ma35d1_port *to_ma35d1_uart_port(struct uart_port *uart)
+{
+	return container_of(uart, struct uart_ma35d1_port, port);
+}
+
+static u32 serial_in(struct uart_ma35d1_port *p, u32 offset)
+{
+	return readl_relaxed(p->port.membase + offset);
+}
+
+static void serial_out(struct uart_ma35d1_port *p, u32 offset, u32 value)
+{
+	writel_relaxed(value, p->port.membase + offset);
+}
+
+static void __stop_tx(struct uart_ma35d1_port *p)
+{
+	u32 ier;
+
+	ier = serial_in(p, MA35_IER_REG);
+	if (ier & MA35_IER_THRE_IEN)
+		serial_out(p, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_tx(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	__stop_tx(up);
+}
+
+static void transmit_chars(struct uart_ma35d1_port *up)
+{
+	u32 count;
+	u8 ch;
+
+	if (uart_tx_stopped(&up->port)) {
+		ma35d1serial_stop_tx(&up->port);
+		return;
+	}
+	count = MA35_UART_FIFO_DEPTH - FIELD_GET(MA35_FSR_TXPTR_MSK,
+						 serial_in(up, MA35_FSR_REG));
+	uart_port_tx_limited(&up->port, ch, count,
+			     !(serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_FULL),
+			     serial_out(up, MA35_THR_REG, ch),
+			     ({}));
+}
+
+static void ma35d1serial_start_tx(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 ier;
+
+	ier = serial_in(up, MA35_IER_REG);
+	serial_out(up, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+	transmit_chars(up);
+	serial_out(up, MA35_IER_REG, ier | MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_rx(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 ier;
+
+	ier = serial_in(up, MA35_IER_REG);
+	ier &= ~MA35_IER_RDA_IEN;
+	serial_out(up, MA35_IER_REG, ier);
+}
+
+static void receive_chars(struct uart_ma35d1_port *up)
+{
+	int max_count = 256;
+	u8 ch, flag;
+	u32 fsr;
+
+	fsr = serial_in(up, MA35_FSR_REG);
+	do {
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+				    MA35_FSR_PEF | MA35_FSR_RX_OVER_IF))) {
+			if (fsr & MA35_FSR_BIF) {
+				up->port.icount.brk++;
+				if (uart_handle_break(&up->port))
+					continue;
+			}
+			if (fsr & MA35_FSR_FEF)
+				up->port.icount.frame++;
+			if (fsr & MA35_FSR_PEF)
+				up->port.icount.parity++;
+			if (fsr & MA35_FSR_RX_OVER_IF)
+				up->port.icount.overrun++;
+
+			serial_out(up, MA35_FSR_REG,
+				   fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+					  MA35_FSR_PEF | MA35_FSR_RX_OVER_IF));
+			if (fsr & MA35_FSR_BIF)
+				flag = TTY_BREAK;
+			else if (fsr & MA35_FSR_PEF)
+				flag = TTY_PARITY;
+			else if (fsr & MA35_FSR_FEF)
+				flag = TTY_FRAME;
+		}
+
+		ch = serial_in(up, MA35_RBR_REG);
+		if (uart_handle_sysrq_char(&up->port, ch))
+			continue;
+
+		spin_lock(&up->port.lock);
+		uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
+		spin_unlock(&up->port.lock);
+
+		fsr = serial_in(up, MA35_FSR_REG);
+	} while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
+
+	spin_lock(&up->port.lock);
+	tty_flip_buffer_push(&up->port.state->port);
+	spin_unlock(&up->port.lock);
+}
+
+static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 isr, fsr;
+
+	isr = serial_in(up, MA35_ISR_REG);
+	fsr = serial_in(up, MA35_FSR_REG);
+
+	if (!(isr & MA35_ISR_IF_CHECK))
+		return IRQ_NONE;
+
+	if (isr & (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF))
+		receive_chars(up);
+	if (isr & MA35_ISR_THRE_INT)
+		transmit_chars(up);
+	if (fsr & MA35_FSR_TX_OVER_IF)
+		serial_out(up, MA35_FSR_REG, MA35_FSR_TX_OVER_IF);
+
+	return IRQ_HANDLED;
+}
+
+static u32 ma35d1serial_tx_empty(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 fsr;
+
+	fsr = serial_in(up, MA35_FSR_REG);
+	if ((fsr & MA35_FSR_TX_BOTH_EMPTY) == MA35_FSR_TX_BOTH_EMPTY)
+		return TIOCSER_TEMT;
+	else
+		return 0;
+}
+
+static u32 ma35d1serial_get_mctrl(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 status;
+	u32 ret = 0;
+
+	status = serial_in(up, MA35_MSR_REG);
+	if (!(status & MA35_MSR_CTSSTS))
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void ma35d1serial_set_mctrl(struct uart_port *port, u32 mctrl)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 mcr, msr, ier;
+
+	mcr = serial_in(up, MA35_MCR_REG);
+	mcr &= ~MA35_MCR_RTS_CTRL;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= MA35_MCR_RTSACTLV;
+	else
+		mcr &= ~MA35_MCR_RTSACTLV;
+
+	if (up->mcr & UART_MCR_AFE) {
+		ier = serial_in(up, MA35_IER_REG);
+		ier |= MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS;
+		serial_out(up, MA35_IER_REG, ier);
+		up->port.flags |= UPF_HARD_FLOW;
+	} else {
+		ier = serial_in(up, MA35_IER_REG);
+		ier &= ~(MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS);
+		serial_out(up, MA35_IER_REG, ier);
+		up->port.flags &= ~UPF_HARD_FLOW;
+	}
+
+	msr = serial_in(up, MA35_MSR_REG);
+	msr |= MA35_MSR_CTSACTLV;
+	serial_out(up, MA35_MSR_REG, msr);
+	serial_out(up, MA35_MCR_REG, mcr);
+}
+
+static void ma35d1serial_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	unsigned long flags;
+	u32 lcr;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	lcr = serial_in(up, MA35_LCR_REG);
+	if (break_state != 0)
+		lcr |= MA35_LCR_BREAK;
+	else
+		lcr &= ~MA35_LCR_BREAK;
+	serial_out(up, MA35_LCR_REG, lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int ma35d1serial_startup(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 fcr;
+	int retval;
+
+	/* Reset FIFO */
+	serial_out(up, MA35_FCR_REG, MA35_FCR_TFR | MA35_FCR_RFR);
+
+	/* Clear pending interrupts */
+	serial_out(up, MA35_ISR_REG, MA35_ISR_ALL);
+
+	retval = request_irq(port->irq, ma35d1serial_interrupt, 0,
+			     dev_name(port->dev), port);
+	if (retval) {
+		dev_err(up->port.dev, "request irq failed.\n");
+		return retval;
+	}
+
+	fcr = serial_in(up, MA35_FCR_REG);
+	fcr |= MA35_FCR_RFITL_4BYTES | MA35_FCR_RTSTL_8BYTES;
+	serial_out(up, MA35_FCR_REG, fcr);
+	serial_out(up, MA35_LCR_REG, MA35_LCR_WLS_8BITS);
+	serial_out(up, MA35_TOR_REG, MA35_UART_RX_TOUT);
+	serial_out(up, MA35_IER_REG, MA35_IER_CONFIG);
+	return 0;
+}
+
+static void ma35d1serial_shutdown(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	serial_out(up, MA35_IER_REG, 0);
+	free_irq(port->irq, port);
+}
+
+static void ma35d1serial_set_termios(struct uart_port *port,
+				     struct ktermios *termios,
+				     const struct ktermios *old)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	unsigned long flags;
+	u32 baud, quot;
+	u32 lcr = 0;
+
+	lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+	if (termios->c_cflag & CSTOPB)
+		lcr |= MA35_LCR_NSB;
+	if (termios->c_cflag & PARENB)
+		lcr |= MA35_LCR_PBE;
+	if (!(termios->c_cflag & PARODD))
+		lcr |= MA35_LCR_EPE;
+	if (termios->c_cflag & CMSPAR)
+		lcr |= MA35_LCR_SPE;
+
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / MA35_BAUD_DIV_MAX,
+				  port->uartclk / MA35_BAUD_DIV_MIN);
+
+	/* MA35D1 UART baud rate equation: baudrate = UART_CLK / (quot + 2) */
+	quot = (port->uartclk / baud) - 2;
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		up->port.read_status_mask |= MA35_FSR_BIF;
+
+	/* Characteres to ignore */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= MA35_FSR_BIF;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= MA35_FSR_RX_OVER_IF;
+	}
+	if (termios->c_cflag & CRTSCTS)
+		up->mcr |= UART_MCR_AFE;
+	else
+		up->mcr &= ~UART_MCR_AFE;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
+
+	serial_out(up, MA35_BAUD_REG, MA35_BAUD_MODE2 | FIELD_PREP(MA35_BAUD_MASK, quot));
+
+	serial_out(up, MA35_LCR_REG, lcr);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ma35d1serial_type(struct uart_port *port)
+{
+	return "ma35d1-uart";
+}
+
+static void ma35d1serial_config_port(struct uart_port *port, int flags)
+{
+	/*
+	 * Driver core for serial ports forces a non-zero value for port type.
+	 * Write an arbitrary value here to accommodate the serial core driver,
+	 * as ID part of UAPI is redundant.
+	 */
+	port->type = 1;
+}
+
+static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (port->type != PORT_UNKNOWN && ser->type != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops ma35d1serial_ops = {
+	.tx_empty     = ma35d1serial_tx_empty,
+	.set_mctrl    = ma35d1serial_set_mctrl,
+	.get_mctrl    = ma35d1serial_get_mctrl,
+	.stop_tx      = ma35d1serial_stop_tx,
+	.start_tx     = ma35d1serial_start_tx,
+	.stop_rx      = ma35d1serial_stop_rx,
+	.break_ctl    = ma35d1serial_break_ctl,
+	.startup      = ma35d1serial_startup,
+	.shutdown     = ma35d1serial_shutdown,
+	.set_termios  = ma35d1serial_set_termios,
+	.type         = ma35d1serial_type,
+	.config_port  = ma35d1serial_config_port,
+	.verify_port  = ma35d1serial_verify_port,
+};
+
+static const struct of_device_id ma35d1_serial_of_match[] = {
+	{ .compatible = "nuvoton,ma35d1-uart" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ma35d1_serial_of_match);
+
+#ifdef CONFIG_SERIAL_NUVOTON_MA35D1_CONSOLE
+
+static struct device_node *ma35d1serial_uart_nodes[MA35_UART_NR];
+
+static void wait_for_xmitr(struct uart_ma35d1_port *up)
+{
+	unsigned int reg = 0;
+
+	read_poll_timeout_atomic(serial_in, reg, reg & MA35_FSR_TX_EMPTY,
+				 1, 10000, false,
+				 up, MA35_FSR_REG);
+}
+
+static void ma35d1serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	wait_for_xmitr(up);
+	serial_out(up, MA35_THR_REG, ch);
+}
+
+/*
+ *  Print a string to the serial port trying not to disturb
+ *  any possible real use of the port...
+ *
+ *  The console_lock must be held when we get here.
+ */
+static void ma35d1serial_console_write(struct console *co, const char *s, u32 count)
+{
+	struct uart_ma35d1_port *up;
+	unsigned long flags;
+	int locked = 1;
+	u32 ier;
+
+	if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
+		pr_warn("Failed to write on ononsole port %x, out of range\n",
+			co->index);
+		return;
+	}
+
+	up = &ma35d1serial_ports[co->index];
+
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 *  First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, MA35_IER_REG);
+	serial_out(up, MA35_IER_REG, 0);
+
+	uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
+
+	wait_for_xmitr(up);
+	serial_out(up, MA35_IER_REG, ier);
+
+	if (locked)
+		spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ma35d1serial_console_setup(struct console *co, char *options)
+{
+	struct device_node *np;
+	struct uart_ma35d1_port *p;
+	u32 val32[4];
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
+		pr_debug("Console Port%x out of range\n", co->index);
+		return -EINVAL;
+	}
+
+	np = ma35d1serial_uart_nodes[co->index];
+	p = &ma35d1serial_ports[co->index];
+	if (!np || !p)
+		return -ENODEV;
+
+	if (of_property_read_u32_array(np, "reg", val32, ARRAY_SIZE(val32)) != 0)
+		return -EINVAL;
+
+	p->port.iobase = val32[1];
+	p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
+	if (!p->port.membase)
+		return -ENOMEM;
+
+	p->port.ops = &ma35d1serial_ops;
+	p->port.line = 0;
+	p->port.uartclk = MA35_UART_CONSOLE_CLK;
+
+	port = &ma35d1serial_ports[co->index].port;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console ma35d1serial_console = {
+	.name    = "ttyNVT",
+	.write   = ma35d1serial_console_write,
+	.device  = uart_console_device,
+	.setup   = ma35d1serial_console_setup,
+	.flags   = CON_PRINTBUFFER | CON_ENABLED,
+	.index   = -1,
+	.data    = &ma35d1serial_reg,
+};
+
+static void ma35d1serial_console_init_port(void)
+{
+	u32 i = 0;
+	struct device_node *np;
+
+	for_each_matching_node(np, ma35d1_serial_of_match) {
+		if (ma35d1serial_uart_nodes[i] == NULL) {
+			of_node_get(np);
+			ma35d1serial_uart_nodes[i] = np;
+			i++;
+			if (i == MA35_UART_NR)
+				break;
+		}
+	}
+}
+
+static int __init ma35d1serial_console_init(void)
+{
+	ma35d1serial_console_init_port();
+	register_console(&ma35d1serial_console);
+	return 0;
+}
+console_initcall(ma35d1serial_console_init);
+
+#define MA35D1SERIAL_CONSOLE    (&ma35d1serial_console)
+#else
+#define MA35D1SERIAL_CONSOLE    NULL
+#endif
+
+static struct uart_driver ma35d1serial_reg = {
+	.owner        = THIS_MODULE,
+	.driver_name  = "serial",
+	.dev_name     = "ttyNVT",
+	.major        = TTY_MAJOR,
+	.minor        = 64,
+	.cons         = MA35D1SERIAL_CONSOLE,
+	.nr           = MA35_UART_NR,
+};
+
+/*
+ * Register a set of serial devices attached to a platform device.
+ * The list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set.
+ */
+static int ma35d1serial_probe(struct platform_device *pdev)
+{
+	struct resource *res_mem;
+	struct uart_ma35d1_port *up;
+	int ret = 0;
+
+	if (pdev->dev.of_node) {
+		ret = of_alias_get_id(pdev->dev.of_node, "serial");
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
+			return ret;
+		}
+	}
+	up = &ma35d1serial_ports[ret];
+	up->port.line = ret;
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem)
+		return -ENODEV;
+
+	up->port.iobase = res_mem->start;
+	up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
+	up->port.ops = &ma35d1serial_ops;
+
+	spin_lock_init(&up->port.lock);
+
+	up->clk = of_clk_get(pdev->dev.of_node, 0);
+	if (IS_ERR(up->clk)) {
+		ret = PTR_ERR(up->clk);
+		dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
+		goto err_iounmap;
+	}
+
+	ret = clk_prepare_enable(up->clk);
+	if (ret)
+		goto err_iounmap;
+
+	if (up->port.line != 0)
+		up->port.uartclk = clk_get_rate(up->clk);
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		goto err_clk_disable;
+
+	up->port.irq = ret;
+	up->port.dev = &pdev->dev;
+	up->port.flags = UPF_BOOT_AUTOCONF;
+
+	platform_set_drvdata(pdev, up);
+
+	ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
+	if (ret < 0)
+		goto err_free_irq;
+
+	return 0;
+
+err_free_irq:
+	free_irq(up->port.irq, &up->port);
+
+err_clk_disable:
+	clk_disable_unprepare(up->clk);
+
+err_iounmap:
+	iounmap(up->port.membase);
+	return ret;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int ma35d1serial_remove(struct platform_device *dev)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	uart_remove_one_port(&ma35d1serial_reg, port);
+	clk_disable_unprepare(up->clk);
+	return 0;
+}
+
+static int ma35d1serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	uart_suspend_port(&ma35d1serial_reg, &up->port);
+	if (up->port.line == 0) {
+		up->console_baud_rate = serial_in(up, MA35_BAUD_REG);
+		up->console_line = serial_in(up, MA35_LCR_REG);
+		up->console_int = serial_in(up, MA35_IER_REG);
+	}
+	return 0;
+}
+
+static int ma35d1serial_resume(struct platform_device *dev)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	if (up->port.line == 0) {
+		serial_out(up, MA35_BAUD_REG, up->console_baud_rate);
+		serial_out(up, MA35_LCR_REG, up->console_line);
+		serial_out(up, MA35_IER_REG, up->console_int);
+	}
+	uart_resume_port(&ma35d1serial_reg, &up->port);
+	return 0;
+}
+
+static struct platform_driver ma35d1serial_driver = {
+	.probe      = ma35d1serial_probe,
+	.remove     = ma35d1serial_remove,
+	.suspend    = ma35d1serial_suspend,
+	.resume     = ma35d1serial_resume,
+	.driver     = {
+		.name   = "ma35d1-uart",
+		.of_match_table = of_match_ptr(ma35d1_serial_of_match),
+	},
+};
+
+static int __init ma35d1serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&ma35d1serial_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&ma35d1serial_driver);
+	if (ret)
+		uart_unregister_driver(&ma35d1serial_reg);
+
+	return ret;
+}
+
+static void __exit ma35d1serial_exit(void)
+{
+	platform_driver_unregister(&ma35d1serial_driver);
+	uart_unregister_driver(&ma35d1serial_reg);
+}
+
+module_init(ma35d1serial_init);
+module_exit(ma35d1serial_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MA35D1 serial driver");
diff --git a/drivers/tty/serial/max3100.c b/drivers/tty/serial/max3100.c
new file mode 100644
index 000000000..5efb2b593
--- /dev/null
+++ b/drivers/tty/serial/max3100.c
@@ -0,0 +1,903 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *
+ *  Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
+ *
+ * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
+ * to use polling for flow control. TX empty IRQ is unusable, since
+ * writing conf clears FIFO buffer and we cannot have this interrupt
+ * always asking us for attention.
+ *
+ * Example platform data:
+
+ static struct plat_max3100 max3100_plat_data = {
+ .loopback = 0,
+ .crystal = 0,
+ .poll_time = 100,
+ };
+
+ static struct spi_board_info spi_board_info[] = {
+ {
+ .modalias	= "max3100",
+ .platform_data	= &max3100_plat_data,
+ .irq		= IRQ_EINT12,
+ .max_speed_hz	= 5*1000*1000,
+ .chip_select	= 0,
+ },
+ };
+
+ * The initial minor number is 209 in the low-density serial port:
+ * mknod /dev/ttyMAX0 c 204 209
+ */
+
+#define MAX3100_MAJOR 204
+#define MAX3100_MINOR 209
+/* 4 MAX3100s should be enough for everyone */
+#define MAX_MAX3100 4
+
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/spi/spi.h>
+#include <linux/freezer.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#include <linux/serial_max3100.h>
+
+#define MAX3100_C    (1<<14)
+#define MAX3100_D    (0<<14)
+#define MAX3100_W    (1<<15)
+#define MAX3100_RX   (0<<15)
+
+#define MAX3100_WC   (MAX3100_W  | MAX3100_C)
+#define MAX3100_RC   (MAX3100_RX | MAX3100_C)
+#define MAX3100_WD   (MAX3100_W  | MAX3100_D)
+#define MAX3100_RD   (MAX3100_RX | MAX3100_D)
+#define MAX3100_CMD  (3 << 14)
+
+#define MAX3100_T    (1<<14)
+#define MAX3100_R    (1<<15)
+
+#define MAX3100_FEN  (1<<13)
+#define MAX3100_SHDN (1<<12)
+#define MAX3100_TM   (1<<11)
+#define MAX3100_RM   (1<<10)
+#define MAX3100_PM   (1<<9)
+#define MAX3100_RAM  (1<<8)
+#define MAX3100_IR   (1<<7)
+#define MAX3100_ST   (1<<6)
+#define MAX3100_PE   (1<<5)
+#define MAX3100_L    (1<<4)
+#define MAX3100_BAUD (0xf)
+
+#define MAX3100_TE   (1<<10)
+#define MAX3100_RAFE (1<<10)
+#define MAX3100_RTS  (1<<9)
+#define MAX3100_CTS  (1<<9)
+#define MAX3100_PT   (1<<8)
+#define MAX3100_DATA (0xff)
+
+#define MAX3100_RT   (MAX3100_R | MAX3100_T)
+#define MAX3100_RTC  (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
+
+/* the following simulate a status reg for ignore_status_mask */
+#define MAX3100_STATUS_PE 1
+#define MAX3100_STATUS_FE 2
+#define MAX3100_STATUS_OE 4
+
+struct max3100_port {
+	struct uart_port port;
+	struct spi_device *spi;
+
+	int cts;	        /* last CTS received for flow ctrl */
+	int tx_empty;		/* last TX empty bit */
+
+	spinlock_t conf_lock;	/* shared data */
+	int conf_commit;	/* need to make changes */
+	int conf;		/* configuration for the MAX31000
+				 * (bits 0-7, bits 8-11 are irqs) */
+	int rts_commit;	        /* need to change rts */
+	int rts;		/* rts status */
+	int baud;		/* current baud rate */
+
+	int parity;		/* keeps track if we should send parity */
+#define MAX3100_PARITY_ON 1
+#define MAX3100_PARITY_ODD 2
+#define MAX3100_7BIT 4
+	int rx_enabled;	        /* if we should rx chars */
+
+	int irq;		/* irq assigned to the max3100 */
+
+	int minor;		/* minor number */
+	int crystal;		/* 1 if 3.6864Mhz crystal 0 for 1.8432 */
+	int loopback;		/* 1 if we are in loopback mode */
+
+	/* for handling irqs: need workqueue since we do spi_sync */
+	struct workqueue_struct *workqueue;
+	struct work_struct work;
+	/* set to 1 to make the workhandler exit as soon as possible */
+	int  force_end_work;
+	/* need to know we are suspending to avoid deadlock on workqueue */
+	int suspending;
+
+	/* hook for suspending MAX3100 via dedicated pin */
+	void (*max3100_hw_suspend) (int suspend);
+
+	/* poll time (in ms) for ctrl lines */
+	int poll_time;
+	/* and its timer */
+	struct timer_list	timer;
+};
+
+static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
+static DEFINE_MUTEX(max3100s_lock);		   /* race on probe */
+
+static int max3100_do_parity(struct max3100_port *s, u16 c)
+{
+	int parity;
+
+	if (s->parity & MAX3100_PARITY_ODD)
+		parity = 1;
+	else
+		parity = 0;
+
+	if (s->parity & MAX3100_7BIT)
+		c &= 0x7f;
+	else
+		c &= 0xff;
+
+	parity = parity ^ (hweight8(c) & 1);
+	return parity;
+}
+
+static int max3100_check_parity(struct max3100_port *s, u16 c)
+{
+	return max3100_do_parity(s, c) == ((c >> 8) & 1);
+}
+
+static void max3100_calc_parity(struct max3100_port *s, u16 *c)
+{
+	if (s->parity & MAX3100_7BIT)
+		*c &= 0x7f;
+	else
+		*c &= 0xff;
+
+	if (s->parity & MAX3100_PARITY_ON)
+		*c |= max3100_do_parity(s, *c) << 8;
+}
+
+static void max3100_work(struct work_struct *w);
+
+static void max3100_dowork(struct max3100_port *s)
+{
+	if (!s->force_end_work && !freezing(current) && !s->suspending)
+		queue_work(s->workqueue, &s->work);
+}
+
+static void max3100_timeout(struct timer_list *t)
+{
+	struct max3100_port *s = from_timer(s, t, timer);
+
+	if (s->port.state) {
+		max3100_dowork(s);
+		mod_timer(&s->timer, jiffies + s->poll_time);
+	}
+}
+
+static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
+{
+	struct spi_message message;
+	u16 etx, erx;
+	int status;
+	struct spi_transfer tran = {
+		.tx_buf = &etx,
+		.rx_buf = &erx,
+		.len = 2,
+	};
+
+	etx = cpu_to_be16(tx);
+	spi_message_init(&message);
+	spi_message_add_tail(&tran, &message);
+	status = spi_sync(s->spi, &message);
+	if (status) {
+		dev_warn(&s->spi->dev, "error while calling spi_sync\n");
+		return -EIO;
+	}
+	*rx = be16_to_cpu(erx);
+	s->tx_empty = (*rx & MAX3100_T) > 0;
+	dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
+	return 0;
+}
+
+static int max3100_handlerx(struct max3100_port *s, u16 rx)
+{
+	unsigned int status = 0;
+	int ret = 0, cts;
+	u8 ch, flg;
+
+	if (rx & MAX3100_R && s->rx_enabled) {
+		dev_dbg(&s->spi->dev, "%s\n", __func__);
+		ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
+		if (rx & MAX3100_RAFE) {
+			s->port.icount.frame++;
+			flg = TTY_FRAME;
+			status |= MAX3100_STATUS_FE;
+		} else {
+			if (s->parity & MAX3100_PARITY_ON) {
+				if (max3100_check_parity(s, rx)) {
+					s->port.icount.rx++;
+					flg = TTY_NORMAL;
+				} else {
+					s->port.icount.parity++;
+					flg = TTY_PARITY;
+					status |= MAX3100_STATUS_PE;
+				}
+			} else {
+				s->port.icount.rx++;
+				flg = TTY_NORMAL;
+			}
+		}
+		uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
+		ret = 1;
+	}
+
+	cts = (rx & MAX3100_CTS) > 0;
+	if (s->cts != cts) {
+		s->cts = cts;
+		uart_handle_cts_change(&s->port, cts);
+	}
+
+	return ret;
+}
+
+static void max3100_work(struct work_struct *w)
+{
+	struct max3100_port *s = container_of(w, struct max3100_port, work);
+	int rxchars;
+	u16 tx, rx;
+	int conf, cconf, crts;
+	struct circ_buf *xmit = &s->port.state->xmit;
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	rxchars = 0;
+	do {
+		spin_lock(&s->conf_lock);
+		conf = s->conf;
+		cconf = s->conf_commit;
+		s->conf_commit = 0;
+		crts = s->rts_commit;
+		s->rts_commit = 0;
+		spin_unlock(&s->conf_lock);
+		if (cconf)
+			max3100_sr(s, MAX3100_WC | conf, &rx);
+		if (crts) {
+			max3100_sr(s, MAX3100_WD | MAX3100_TE |
+				   (s->rts ? MAX3100_RTS : 0), &rx);
+			rxchars += max3100_handlerx(s, rx);
+		}
+
+		max3100_sr(s, MAX3100_RD, &rx);
+		rxchars += max3100_handlerx(s, rx);
+
+		if (rx & MAX3100_T) {
+			tx = 0xffff;
+			if (s->port.x_char) {
+				tx = s->port.x_char;
+				s->port.icount.tx++;
+				s->port.x_char = 0;
+			} else if (!uart_circ_empty(xmit) &&
+				   !uart_tx_stopped(&s->port)) {
+				tx = xmit->buf[xmit->tail];
+				uart_xmit_advance(&s->port, 1);
+			}
+			if (tx != 0xffff) {
+				max3100_calc_parity(s, &tx);
+				tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
+				max3100_sr(s, tx, &rx);
+				rxchars += max3100_handlerx(s, rx);
+			}
+		}
+
+		if (rxchars > 16) {
+			tty_flip_buffer_push(&s->port.state->port);
+			rxchars = 0;
+		}
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&s->port);
+
+	} while (!s->force_end_work &&
+		 !freezing(current) &&
+		 ((rx & MAX3100_R) ||
+		  (!uart_circ_empty(xmit) &&
+		   !uart_tx_stopped(&s->port))));
+
+	if (rxchars > 0)
+		tty_flip_buffer_push(&s->port.state->port);
+}
+
+static irqreturn_t max3100_irq(int irqno, void *dev_id)
+{
+	struct max3100_port *s = dev_id;
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	max3100_dowork(s);
+	return IRQ_HANDLED;
+}
+
+static void max3100_enable_ms(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	if (s->poll_time > 0)
+		mod_timer(&s->timer, jiffies);
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static void max3100_start_tx(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	max3100_dowork(s);
+}
+
+static void max3100_stop_rx(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	s->rx_enabled = 0;
+	spin_lock(&s->conf_lock);
+	s->conf &= ~MAX3100_RM;
+	s->conf_commit = 1;
+	spin_unlock(&s->conf_lock);
+	max3100_dowork(s);
+}
+
+static unsigned int max3100_tx_empty(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	/* may not be truly up-to-date */
+	max3100_dowork(s);
+	return s->tx_empty;
+}
+
+static unsigned int max3100_get_mctrl(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	/* may not be truly up-to-date */
+	max3100_dowork(s);
+	/* always assert DCD and DSR since these lines are not wired */
+	return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+	int rts;
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	rts = (mctrl & TIOCM_RTS) > 0;
+
+	spin_lock(&s->conf_lock);
+	if (s->rts != rts) {
+		s->rts = rts;
+		s->rts_commit = 1;
+		max3100_dowork(s);
+	}
+	spin_unlock(&s->conf_lock);
+}
+
+static void
+max3100_set_termios(struct uart_port *port, struct ktermios *termios,
+		    const struct ktermios *old)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+	int baud = 0;
+	unsigned cflag;
+	u32 param_new, param_mask, parity = 0;
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	cflag = termios->c_cflag;
+	param_mask = 0;
+
+	baud = tty_termios_baud_rate(termios);
+	param_new = s->conf & MAX3100_BAUD;
+	switch (baud) {
+	case 300:
+		if (s->crystal)
+			baud = s->baud;
+		else
+			param_new = 15;
+		break;
+	case 600:
+		param_new = 14 + s->crystal;
+		break;
+	case 1200:
+		param_new = 13 + s->crystal;
+		break;
+	case 2400:
+		param_new = 12 + s->crystal;
+		break;
+	case 4800:
+		param_new = 11 + s->crystal;
+		break;
+	case 9600:
+		param_new = 10 + s->crystal;
+		break;
+	case 19200:
+		param_new = 9 + s->crystal;
+		break;
+	case 38400:
+		param_new = 8 + s->crystal;
+		break;
+	case 57600:
+		param_new = 1 + s->crystal;
+		break;
+	case 115200:
+		param_new = 0 + s->crystal;
+		break;
+	case 230400:
+		if (s->crystal)
+			param_new = 0;
+		else
+			baud = s->baud;
+		break;
+	default:
+		baud = s->baud;
+	}
+	tty_termios_encode_baud_rate(termios, baud, baud);
+	s->baud = baud;
+	param_mask |= MAX3100_BAUD;
+
+	if ((cflag & CSIZE) == CS8) {
+		param_new &= ~MAX3100_L;
+		parity &= ~MAX3100_7BIT;
+	} else {
+		param_new |= MAX3100_L;
+		parity |= MAX3100_7BIT;
+		cflag = (cflag & ~CSIZE) | CS7;
+	}
+	param_mask |= MAX3100_L;
+
+	if (cflag & CSTOPB)
+		param_new |= MAX3100_ST;
+	else
+		param_new &= ~MAX3100_ST;
+	param_mask |= MAX3100_ST;
+
+	if (cflag & PARENB) {
+		param_new |= MAX3100_PE;
+		parity |= MAX3100_PARITY_ON;
+	} else {
+		param_new &= ~MAX3100_PE;
+		parity &= ~MAX3100_PARITY_ON;
+	}
+	param_mask |= MAX3100_PE;
+
+	if (cflag & PARODD)
+		parity |= MAX3100_PARITY_ODD;
+	else
+		parity &= ~MAX3100_PARITY_ODD;
+
+	/* mask termios capabilities we don't support */
+	cflag &= ~CMSPAR;
+	termios->c_cflag = cflag;
+
+	s->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		s->port.ignore_status_mask |=
+			MAX3100_STATUS_PE | MAX3100_STATUS_FE |
+			MAX3100_STATUS_OE;
+
+	if (s->poll_time > 0)
+		del_timer_sync(&s->timer);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_lock(&s->conf_lock);
+	s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
+	s->conf_commit = 1;
+	s->parity = parity;
+	spin_unlock(&s->conf_lock);
+	max3100_dowork(s);
+
+	if (UART_ENABLE_MS(&s->port, termios->c_cflag))
+		max3100_enable_ms(&s->port);
+}
+
+static void max3100_shutdown(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	if (s->suspending)
+		return;
+
+	s->force_end_work = 1;
+
+	if (s->poll_time > 0)
+		del_timer_sync(&s->timer);
+
+	if (s->workqueue) {
+		destroy_workqueue(s->workqueue);
+		s->workqueue = NULL;
+	}
+	if (s->irq)
+		free_irq(s->irq, s);
+
+	/* set shutdown mode to save power */
+	if (s->max3100_hw_suspend)
+		s->max3100_hw_suspend(1);
+	else  {
+		u16 tx, rx;
+
+		tx = MAX3100_WC | MAX3100_SHDN;
+		max3100_sr(s, tx, &rx);
+	}
+}
+
+static int max3100_startup(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+	char b[12];
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	s->conf = MAX3100_RM;
+	s->baud = s->crystal ? 230400 : 115200;
+	s->rx_enabled = 1;
+
+	if (s->suspending)
+		return 0;
+
+	s->force_end_work = 0;
+	s->parity = 0;
+	s->rts = 0;
+
+	sprintf(b, "max3100-%d", s->minor);
+	s->workqueue = create_freezable_workqueue(b);
+	if (!s->workqueue) {
+		dev_warn(&s->spi->dev, "cannot create workqueue\n");
+		return -EBUSY;
+	}
+	INIT_WORK(&s->work, max3100_work);
+
+	if (request_irq(s->irq, max3100_irq,
+			IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
+		dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
+		s->irq = 0;
+		destroy_workqueue(s->workqueue);
+		s->workqueue = NULL;
+		return -EBUSY;
+	}
+
+	if (s->loopback) {
+		u16 tx, rx;
+		tx = 0x4001;
+		max3100_sr(s, tx, &rx);
+	}
+
+	if (s->max3100_hw_suspend)
+		s->max3100_hw_suspend(0);
+	s->conf_commit = 1;
+	max3100_dowork(s);
+	/* wait for clock to settle */
+	msleep(50);
+
+	max3100_enable_ms(&s->port);
+
+	return 0;
+}
+
+static const char *max3100_type(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
+}
+
+static void max3100_release_port(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static void max3100_config_port(struct uart_port *port, int flags)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	if (flags & UART_CONFIG_TYPE)
+		s->port.type = PORT_MAX3100;
+}
+
+static int max3100_verify_port(struct uart_port *port,
+			       struct serial_struct *ser)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+	int ret = -EINVAL;
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
+		ret = 0;
+	return ret;
+}
+
+static void max3100_stop_tx(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static int max3100_request_port(struct uart_port *port)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+	return 0;
+}
+
+static void max3100_break_ctl(struct uart_port *port, int break_state)
+{
+	struct max3100_port *s = container_of(port,
+					      struct max3100_port,
+					      port);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static const struct uart_ops max3100_ops = {
+	.tx_empty	= max3100_tx_empty,
+	.set_mctrl	= max3100_set_mctrl,
+	.get_mctrl	= max3100_get_mctrl,
+	.stop_tx        = max3100_stop_tx,
+	.start_tx	= max3100_start_tx,
+	.stop_rx	= max3100_stop_rx,
+	.enable_ms      = max3100_enable_ms,
+	.break_ctl      = max3100_break_ctl,
+	.startup	= max3100_startup,
+	.shutdown	= max3100_shutdown,
+	.set_termios	= max3100_set_termios,
+	.type		= max3100_type,
+	.release_port   = max3100_release_port,
+	.request_port   = max3100_request_port,
+	.config_port	= max3100_config_port,
+	.verify_port	= max3100_verify_port,
+};
+
+static struct uart_driver max3100_uart_driver = {
+	.owner          = THIS_MODULE,
+	.driver_name    = "ttyMAX",
+	.dev_name       = "ttyMAX",
+	.major          = MAX3100_MAJOR,
+	.minor          = MAX3100_MINOR,
+	.nr             = MAX_MAX3100,
+};
+static int uart_driver_registered;
+
+static int max3100_probe(struct spi_device *spi)
+{
+	int i, retval;
+	struct plat_max3100 *pdata;
+	u16 tx, rx;
+
+	mutex_lock(&max3100s_lock);
+
+	if (!uart_driver_registered) {
+		uart_driver_registered = 1;
+		retval = uart_register_driver(&max3100_uart_driver);
+		if (retval) {
+			printk(KERN_ERR "Couldn't register max3100 uart driver\n");
+			mutex_unlock(&max3100s_lock);
+			return retval;
+		}
+	}
+
+	for (i = 0; i < MAX_MAX3100; i++)
+		if (!max3100s[i])
+			break;
+	if (i == MAX_MAX3100) {
+		dev_warn(&spi->dev, "too many MAX3100 chips\n");
+		mutex_unlock(&max3100s_lock);
+		return -ENOMEM;
+	}
+
+	max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
+	if (!max3100s[i]) {
+		dev_warn(&spi->dev,
+			 "kmalloc for max3100 structure %d failed!\n", i);
+		mutex_unlock(&max3100s_lock);
+		return -ENOMEM;
+	}
+	max3100s[i]->spi = spi;
+	max3100s[i]->irq = spi->irq;
+	spin_lock_init(&max3100s[i]->conf_lock);
+	spi_set_drvdata(spi, max3100s[i]);
+	pdata = dev_get_platdata(&spi->dev);
+	max3100s[i]->crystal = pdata->crystal;
+	max3100s[i]->loopback = pdata->loopback;
+	max3100s[i]->poll_time = msecs_to_jiffies(pdata->poll_time);
+	if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
+		max3100s[i]->poll_time = 1;
+	max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
+	max3100s[i]->minor = i;
+	timer_setup(&max3100s[i]->timer, max3100_timeout, 0);
+
+	dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
+	max3100s[i]->port.irq = max3100s[i]->irq;
+	max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
+	max3100s[i]->port.fifosize = 16;
+	max3100s[i]->port.ops = &max3100_ops;
+	max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
+	max3100s[i]->port.line = i;
+	max3100s[i]->port.type = PORT_MAX3100;
+	max3100s[i]->port.dev = &spi->dev;
+	retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
+	if (retval < 0)
+		dev_warn(&spi->dev,
+			 "uart_add_one_port failed for line %d with error %d\n",
+			 i, retval);
+
+	/* set shutdown mode to save power. Will be woken-up on open */
+	if (max3100s[i]->max3100_hw_suspend)
+		max3100s[i]->max3100_hw_suspend(1);
+	else {
+		tx = MAX3100_WC | MAX3100_SHDN;
+		max3100_sr(max3100s[i], tx, &rx);
+	}
+	mutex_unlock(&max3100s_lock);
+	return 0;
+}
+
+static void max3100_remove(struct spi_device *spi)
+{
+	struct max3100_port *s = spi_get_drvdata(spi);
+	int i;
+
+	mutex_lock(&max3100s_lock);
+
+	/* find out the index for the chip we are removing */
+	for (i = 0; i < MAX_MAX3100; i++)
+		if (max3100s[i] == s) {
+			dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
+			uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
+			kfree(max3100s[i]);
+			max3100s[i] = NULL;
+			break;
+		}
+
+	WARN_ON(i == MAX_MAX3100);
+	
+	/* check if this is the last chip we have */
+	for (i = 0; i < MAX_MAX3100; i++)
+		if (max3100s[i]) {
+			mutex_unlock(&max3100s_lock);
+			return;
+		}
+	pr_debug("removing max3100 driver\n");
+	uart_unregister_driver(&max3100_uart_driver);
+
+	mutex_unlock(&max3100s_lock);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int max3100_suspend(struct device *dev)
+{
+	struct max3100_port *s = dev_get_drvdata(dev);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	disable_irq(s->irq);
+
+	s->suspending = 1;
+	uart_suspend_port(&max3100_uart_driver, &s->port);
+
+	if (s->max3100_hw_suspend)
+		s->max3100_hw_suspend(1);
+	else {
+		/* no HW suspend, so do SW one */
+		u16 tx, rx;
+
+		tx = MAX3100_WC | MAX3100_SHDN;
+		max3100_sr(s, tx, &rx);
+	}
+	return 0;
+}
+
+static int max3100_resume(struct device *dev)
+{
+	struct max3100_port *s = dev_get_drvdata(dev);
+
+	dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+	if (s->max3100_hw_suspend)
+		s->max3100_hw_suspend(0);
+	uart_resume_port(&max3100_uart_driver, &s->port);
+	s->suspending = 0;
+
+	enable_irq(s->irq);
+
+	s->conf_commit = 1;
+	if (s->workqueue)
+		max3100_dowork(s);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
+#define MAX3100_PM_OPS (&max3100_pm_ops)
+
+#else
+#define MAX3100_PM_OPS NULL
+#endif
+
+static struct spi_driver max3100_driver = {
+	.driver = {
+		.name		= "max3100",
+		.pm		= MAX3100_PM_OPS,
+	},
+	.probe		= max3100_probe,
+	.remove		= max3100_remove,
+};
+
+module_spi_driver(max3100_driver);
+
+MODULE_DESCRIPTION("MAX3100 driver");
+MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:max3100");
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
new file mode 100644
index 000000000..db3204d2a
--- /dev/null
+++ b/drivers/tty/serial/max310x.c
@@ -0,0 +1,1702 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver
+ *
+ *  Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
+ *
+ *  Based on max3100.c, by Christian Pellegrin <chripell@evolware.org>
+ *  Based on max3110.c, by Feng Tang <feng.tang@intel.com>
+ *  Based on max3107.c, by Aavamobile
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/spi/spi.h>
+#include <linux/uaccess.h>
+
+#define MAX310X_NAME			"max310x"
+#define MAX310X_MAJOR			204
+#define MAX310X_MINOR			209
+#define MAX310X_UART_NRMAX		16
+
+/* MAX310X register definitions */
+#define MAX310X_RHR_REG			(0x00) /* RX FIFO */
+#define MAX310X_THR_REG			(0x00) /* TX FIFO */
+#define MAX310X_IRQEN_REG		(0x01) /* IRQ enable */
+#define MAX310X_IRQSTS_REG		(0x02) /* IRQ status */
+#define MAX310X_LSR_IRQEN_REG		(0x03) /* LSR IRQ enable */
+#define MAX310X_LSR_IRQSTS_REG		(0x04) /* LSR IRQ status */
+#define MAX310X_REG_05			(0x05)
+#define MAX310X_SPCHR_IRQEN_REG		MAX310X_REG_05 /* Special char IRQ en */
+#define MAX310X_SPCHR_IRQSTS_REG	(0x06) /* Special char IRQ status */
+#define MAX310X_STS_IRQEN_REG		(0x07) /* Status IRQ enable */
+#define MAX310X_STS_IRQSTS_REG		(0x08) /* Status IRQ status */
+#define MAX310X_MODE1_REG		(0x09) /* MODE1 */
+#define MAX310X_MODE2_REG		(0x0a) /* MODE2 */
+#define MAX310X_LCR_REG			(0x0b) /* LCR */
+#define MAX310X_RXTO_REG		(0x0c) /* RX timeout */
+#define MAX310X_HDPIXDELAY_REG		(0x0d) /* Auto transceiver delays */
+#define MAX310X_IRDA_REG		(0x0e) /* IRDA settings */
+#define MAX310X_FLOWLVL_REG		(0x0f) /* Flow control levels */
+#define MAX310X_FIFOTRIGLVL_REG		(0x10) /* FIFO IRQ trigger levels */
+#define MAX310X_TXFIFOLVL_REG		(0x11) /* TX FIFO level */
+#define MAX310X_RXFIFOLVL_REG		(0x12) /* RX FIFO level */
+#define MAX310X_FLOWCTRL_REG		(0x13) /* Flow control */
+#define MAX310X_XON1_REG		(0x14) /* XON1 character */
+#define MAX310X_XON2_REG		(0x15) /* XON2 character */
+#define MAX310X_XOFF1_REG		(0x16) /* XOFF1 character */
+#define MAX310X_XOFF2_REG		(0x17) /* XOFF2 character */
+#define MAX310X_GPIOCFG_REG		(0x18) /* GPIO config */
+#define MAX310X_GPIODATA_REG		(0x19) /* GPIO data */
+#define MAX310X_PLLCFG_REG		(0x1a) /* PLL config */
+#define MAX310X_BRGCFG_REG		(0x1b) /* Baud rate generator conf */
+#define MAX310X_BRGDIVLSB_REG		(0x1c) /* Baud rate divisor LSB */
+#define MAX310X_BRGDIVMSB_REG		(0x1d) /* Baud rate divisor MSB */
+#define MAX310X_CLKSRC_REG		(0x1e) /* Clock source */
+#define MAX310X_REG_1F			(0x1f)
+
+#define MAX310X_REVID_REG		MAX310X_REG_1F /* Revision ID */
+
+#define MAX310X_GLOBALIRQ_REG		MAX310X_REG_1F /* Global IRQ (RO) */
+#define MAX310X_GLOBALCMD_REG		MAX310X_REG_1F /* Global Command (WO) */
+
+/* Extended registers */
+#define MAX310X_SPI_REVID_EXTREG	MAX310X_REG_05 /* Revision ID */
+#define MAX310X_I2C_REVID_EXTREG	(0x25) /* Revision ID */
+
+/* IRQ register bits */
+#define MAX310X_IRQ_LSR_BIT		(1 << 0) /* LSR interrupt */
+#define MAX310X_IRQ_SPCHR_BIT		(1 << 1) /* Special char interrupt */
+#define MAX310X_IRQ_STS_BIT		(1 << 2) /* Status interrupt */
+#define MAX310X_IRQ_RXFIFO_BIT		(1 << 3) /* RX FIFO interrupt */
+#define MAX310X_IRQ_TXFIFO_BIT		(1 << 4) /* TX FIFO interrupt */
+#define MAX310X_IRQ_TXEMPTY_BIT		(1 << 5) /* TX FIFO empty interrupt */
+#define MAX310X_IRQ_RXEMPTY_BIT		(1 << 6) /* RX FIFO empty interrupt */
+#define MAX310X_IRQ_CTS_BIT		(1 << 7) /* CTS interrupt */
+
+/* LSR register bits */
+#define MAX310X_LSR_RXTO_BIT		(1 << 0) /* RX timeout */
+#define MAX310X_LSR_RXOVR_BIT		(1 << 1) /* RX overrun */
+#define MAX310X_LSR_RXPAR_BIT		(1 << 2) /* RX parity error */
+#define MAX310X_LSR_FRERR_BIT		(1 << 3) /* Frame error */
+#define MAX310X_LSR_RXBRK_BIT		(1 << 4) /* RX break */
+#define MAX310X_LSR_RXNOISE_BIT		(1 << 5) /* RX noise */
+#define MAX310X_LSR_CTS_BIT		(1 << 7) /* CTS pin state */
+
+/* Special character register bits */
+#define MAX310X_SPCHR_XON1_BIT		(1 << 0) /* XON1 character */
+#define MAX310X_SPCHR_XON2_BIT		(1 << 1) /* XON2 character */
+#define MAX310X_SPCHR_XOFF1_BIT		(1 << 2) /* XOFF1 character */
+#define MAX310X_SPCHR_XOFF2_BIT		(1 << 3) /* XOFF2 character */
+#define MAX310X_SPCHR_BREAK_BIT		(1 << 4) /* RX break */
+#define MAX310X_SPCHR_MULTIDROP_BIT	(1 << 5) /* 9-bit multidrop addr char */
+
+/* Status register bits */
+#define MAX310X_STS_GPIO0_BIT		(1 << 0) /* GPIO 0 interrupt */
+#define MAX310X_STS_GPIO1_BIT		(1 << 1) /* GPIO 1 interrupt */
+#define MAX310X_STS_GPIO2_BIT		(1 << 2) /* GPIO 2 interrupt */
+#define MAX310X_STS_GPIO3_BIT		(1 << 3) /* GPIO 3 interrupt */
+#define MAX310X_STS_CLKREADY_BIT	(1 << 5) /* Clock ready */
+#define MAX310X_STS_SLEEP_BIT		(1 << 6) /* Sleep interrupt */
+
+/* MODE1 register bits */
+#define MAX310X_MODE1_RXDIS_BIT		(1 << 0) /* RX disable */
+#define MAX310X_MODE1_TXDIS_BIT		(1 << 1) /* TX disable */
+#define MAX310X_MODE1_TXHIZ_BIT		(1 << 2) /* TX pin three-state */
+#define MAX310X_MODE1_RTSHIZ_BIT	(1 << 3) /* RTS pin three-state */
+#define MAX310X_MODE1_TRNSCVCTRL_BIT	(1 << 4) /* Transceiver ctrl enable */
+#define MAX310X_MODE1_FORCESLEEP_BIT	(1 << 5) /* Force sleep mode */
+#define MAX310X_MODE1_AUTOSLEEP_BIT	(1 << 6) /* Auto sleep enable */
+#define MAX310X_MODE1_IRQSEL_BIT	(1 << 7) /* IRQ pin enable */
+
+/* MODE2 register bits */
+#define MAX310X_MODE2_RST_BIT		(1 << 0) /* Chip reset */
+#define MAX310X_MODE2_FIFORST_BIT	(1 << 1) /* FIFO reset */
+#define MAX310X_MODE2_RXTRIGINV_BIT	(1 << 2) /* RX FIFO INT invert */
+#define MAX310X_MODE2_RXEMPTINV_BIT	(1 << 3) /* RX FIFO empty INT invert */
+#define MAX310X_MODE2_SPCHR_BIT		(1 << 4) /* Special chr detect enable */
+#define MAX310X_MODE2_LOOPBACK_BIT	(1 << 5) /* Internal loopback enable */
+#define MAX310X_MODE2_MULTIDROP_BIT	(1 << 6) /* 9-bit multidrop enable */
+#define MAX310X_MODE2_ECHOSUPR_BIT	(1 << 7) /* ECHO suppression enable */
+
+/* LCR register bits */
+#define MAX310X_LCR_LENGTH0_BIT		(1 << 0) /* Word length bit 0 */
+#define MAX310X_LCR_LENGTH1_BIT		(1 << 1) /* Word length bit 1
+						  *
+						  * Word length bits table:
+						  * 00 -> 5 bit words
+						  * 01 -> 6 bit words
+						  * 10 -> 7 bit words
+						  * 11 -> 8 bit words
+						  */
+#define MAX310X_LCR_STOPLEN_BIT		(1 << 2) /* STOP length bit
+						  *
+						  * STOP length bit table:
+						  * 0 -> 1 stop bit
+						  * 1 -> 1-1.5 stop bits if
+						  *      word length is 5,
+						  *      2 stop bits otherwise
+						  */
+#define MAX310X_LCR_PARITY_BIT		(1 << 3) /* Parity bit enable */
+#define MAX310X_LCR_EVENPARITY_BIT	(1 << 4) /* Even parity bit enable */
+#define MAX310X_LCR_FORCEPARITY_BIT	(1 << 5) /* 9-bit multidrop parity */
+#define MAX310X_LCR_TXBREAK_BIT		(1 << 6) /* TX break enable */
+#define MAX310X_LCR_RTS_BIT		(1 << 7) /* RTS pin control */
+
+/* IRDA register bits */
+#define MAX310X_IRDA_IRDAEN_BIT		(1 << 0) /* IRDA mode enable */
+#define MAX310X_IRDA_SIR_BIT		(1 << 1) /* SIR mode enable */
+
+/* Flow control trigger level register masks */
+#define MAX310X_FLOWLVL_HALT_MASK	(0x000f) /* Flow control halt level */
+#define MAX310X_FLOWLVL_RES_MASK	(0x00f0) /* Flow control resume level */
+#define MAX310X_FLOWLVL_HALT(words)	((words / 8) & 0x0f)
+#define MAX310X_FLOWLVL_RES(words)	(((words / 8) & 0x0f) << 4)
+
+/* FIFO interrupt trigger level register masks */
+#define MAX310X_FIFOTRIGLVL_TX_MASK	(0x0f) /* TX FIFO trigger level */
+#define MAX310X_FIFOTRIGLVL_RX_MASK	(0xf0) /* RX FIFO trigger level */
+#define MAX310X_FIFOTRIGLVL_TX(words)	((words / 8) & 0x0f)
+#define MAX310X_FIFOTRIGLVL_RX(words)	(((words / 8) & 0x0f) << 4)
+
+/* Flow control register bits */
+#define MAX310X_FLOWCTRL_AUTORTS_BIT	(1 << 0) /* Auto RTS flow ctrl enable */
+#define MAX310X_FLOWCTRL_AUTOCTS_BIT	(1 << 1) /* Auto CTS flow ctrl enable */
+#define MAX310X_FLOWCTRL_GPIADDR_BIT	(1 << 2) /* Enables that GPIO inputs
+						  * are used in conjunction with
+						  * XOFF2 for definition of
+						  * special character */
+#define MAX310X_FLOWCTRL_SWFLOWEN_BIT	(1 << 3) /* Auto SW flow ctrl enable */
+#define MAX310X_FLOWCTRL_SWFLOW0_BIT	(1 << 4) /* SWFLOW bit 0 */
+#define MAX310X_FLOWCTRL_SWFLOW1_BIT	(1 << 5) /* SWFLOW bit 1
+						  *
+						  * SWFLOW bits 1 & 0 table:
+						  * 00 -> no transmitter flow
+						  *       control
+						  * 01 -> receiver compares
+						  *       XON2 and XOFF2
+						  *       and controls
+						  *       transmitter
+						  * 10 -> receiver compares
+						  *       XON1 and XOFF1
+						  *       and controls
+						  *       transmitter
+						  * 11 -> receiver compares
+						  *       XON1, XON2, XOFF1 and
+						  *       XOFF2 and controls
+						  *       transmitter
+						  */
+#define MAX310X_FLOWCTRL_SWFLOW2_BIT	(1 << 6) /* SWFLOW bit 2 */
+#define MAX310X_FLOWCTRL_SWFLOW3_BIT	(1 << 7) /* SWFLOW bit 3
+						  *
+						  * SWFLOW bits 3 & 2 table:
+						  * 00 -> no received flow
+						  *       control
+						  * 01 -> transmitter generates
+						  *       XON2 and XOFF2
+						  * 10 -> transmitter generates
+						  *       XON1 and XOFF1
+						  * 11 -> transmitter generates
+						  *       XON1, XON2, XOFF1 and
+						  *       XOFF2
+						  */
+
+/* PLL configuration register masks */
+#define MAX310X_PLLCFG_PREDIV_MASK	(0x3f) /* PLL predivision value */
+#define MAX310X_PLLCFG_PLLFACTOR_MASK	(0xc0) /* PLL multiplication factor */
+
+/* Baud rate generator configuration register bits */
+#define MAX310X_BRGCFG_2XMODE_BIT	(1 << 4) /* Double baud rate */
+#define MAX310X_BRGCFG_4XMODE_BIT	(1 << 5) /* Quadruple baud rate */
+
+/* Clock source register bits */
+#define MAX310X_CLKSRC_CRYST_BIT	(1 << 1) /* Crystal osc enable */
+#define MAX310X_CLKSRC_PLL_BIT		(1 << 2) /* PLL enable */
+#define MAX310X_CLKSRC_PLLBYP_BIT	(1 << 3) /* PLL bypass */
+#define MAX310X_CLKSRC_EXTCLK_BIT	(1 << 4) /* External clock enable */
+#define MAX310X_CLKSRC_CLK2RTS_BIT	(1 << 7) /* Baud clk to RTS pin */
+
+/* Global commands */
+#define MAX310X_EXTREG_ENBL		(0xce)
+#define MAX310X_EXTREG_DSBL		(0xcd)
+
+/* Misc definitions */
+#define MAX310X_FIFO_SIZE		(128)
+#define MAX310x_REV_MASK		(0xf8)
+#define MAX310X_WRITE_BIT		0x80
+
+/* MAX3107 specific */
+#define MAX3107_REV_ID			(0xa0)
+
+/* MAX3109 specific */
+#define MAX3109_REV_ID			(0xc0)
+
+/* MAX14830 specific */
+#define MAX14830_BRGCFG_CLKDIS_BIT	(1 << 6) /* Clock Disable */
+#define MAX14830_REV_ID			(0xb0)
+
+struct max310x_if_cfg {
+	int (*extended_reg_enable)(struct device *dev, bool enable);
+
+	unsigned int rev_id_reg;
+};
+
+struct max310x_devtype {
+	struct {
+		unsigned short min;
+		unsigned short max;
+	} slave_addr;
+	char	name[9];
+	int	nr;
+	u8	mode1;
+	int	(*detect)(struct device *);
+	void	(*power)(struct uart_port *, int);
+};
+
+struct max310x_one {
+	struct uart_port	port;
+	struct work_struct	tx_work;
+	struct work_struct	md_work;
+	struct work_struct	rs_work;
+	struct regmap		*regmap;
+
+	u8 rx_buf[MAX310X_FIFO_SIZE];
+};
+#define to_max310x_port(_port) \
+	container_of(_port, struct max310x_one, port)
+
+struct max310x_port {
+	const struct max310x_devtype *devtype;
+	const struct max310x_if_cfg *if_cfg;
+	struct regmap		*regmap;
+	struct clk		*clk;
+#ifdef CONFIG_GPIOLIB
+	struct gpio_chip	gpio;
+#endif
+	struct max310x_one	p[];
+};
+
+static struct uart_driver max310x_uart = {
+	.owner		= THIS_MODULE,
+	.driver_name	= MAX310X_NAME,
+	.dev_name	= "ttyMAX",
+	.major		= MAX310X_MAJOR,
+	.minor		= MAX310X_MINOR,
+	.nr		= MAX310X_UART_NRMAX,
+};
+
+static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
+
+static u8 max310x_port_read(struct uart_port *port, u8 reg)
+{
+	struct max310x_one *one = to_max310x_port(port);
+	unsigned int val = 0;
+
+	regmap_read(one->regmap, reg, &val);
+
+	return val;
+}
+
+static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	regmap_write(one->regmap, reg, val);
+}
+
+static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	regmap_update_bits(one->regmap, reg, mask, val);
+}
+
+static int max3107_detect(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	unsigned int val = 0;
+	int ret;
+
+	ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
+	if (ret)
+		return ret;
+
+	if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
+		dev_err(dev,
+			"%s ID 0x%02x does not match\n", s->devtype->name, val);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int max3108_detect(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	unsigned int val = 0;
+	int ret;
+
+	/* MAX3108 have not REV ID register, we just check default value
+	 * from clocksource register to make sure everything works.
+	 */
+	ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
+	if (ret)
+		return ret;
+
+	if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
+		dev_err(dev, "%s not present\n", s->devtype->name);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int max3109_detect(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	unsigned int val = 0;
+	int ret;
+
+	ret = s->if_cfg->extended_reg_enable(dev, true);
+	if (ret)
+		return ret;
+
+	regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
+	s->if_cfg->extended_reg_enable(dev, false);
+	if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
+		dev_err(dev,
+			"%s ID 0x%02x does not match\n", s->devtype->name, val);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void max310x_power(struct uart_port *port, int on)
+{
+	max310x_port_update(port, MAX310X_MODE1_REG,
+			    MAX310X_MODE1_FORCESLEEP_BIT,
+			    on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
+	if (on)
+		msleep(50);
+}
+
+static int max14830_detect(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	unsigned int val = 0;
+	int ret;
+
+	ret = s->if_cfg->extended_reg_enable(dev, true);
+	if (ret)
+		return ret;
+	
+	regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
+	s->if_cfg->extended_reg_enable(dev, false);
+	if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
+		dev_err(dev,
+			"%s ID 0x%02x does not match\n", s->devtype->name, val);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void max14830_power(struct uart_port *port, int on)
+{
+	max310x_port_update(port, MAX310X_BRGCFG_REG,
+			    MAX14830_BRGCFG_CLKDIS_BIT,
+			    on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
+	if (on)
+		msleep(50);
+}
+
+static const struct max310x_devtype max3107_devtype = {
+	.name	= "MAX3107",
+	.nr	= 1,
+	.mode1	= MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT,
+	.detect	= max3107_detect,
+	.power	= max310x_power,
+	.slave_addr	= {
+		.min = 0x2c,
+		.max = 0x2f,
+	},
+};
+
+static const struct max310x_devtype max3108_devtype = {
+	.name	= "MAX3108",
+	.nr	= 1,
+	.mode1	= MAX310X_MODE1_AUTOSLEEP_BIT,
+	.detect	= max3108_detect,
+	.power	= max310x_power,
+	.slave_addr	= {
+		.min = 0x60,
+		.max = 0x6f,
+	},
+};
+
+static const struct max310x_devtype max3109_devtype = {
+	.name	= "MAX3109",
+	.nr	= 2,
+	.mode1	= MAX310X_MODE1_AUTOSLEEP_BIT,
+	.detect	= max3109_detect,
+	.power	= max310x_power,
+	.slave_addr	= {
+		.min = 0x60,
+		.max = 0x6f,
+	},
+};
+
+static const struct max310x_devtype max14830_devtype = {
+	.name	= "MAX14830",
+	.nr	= 4,
+	.mode1	= MAX310X_MODE1_IRQSEL_BIT,
+	.detect	= max14830_detect,
+	.power	= max14830_power,
+	.slave_addr	= {
+		.min = 0x60,
+		.max = 0x6f,
+	},
+};
+
+static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX310X_IRQSTS_REG:
+	case MAX310X_LSR_IRQSTS_REG:
+	case MAX310X_SPCHR_IRQSTS_REG:
+	case MAX310X_STS_IRQSTS_REG:
+	case MAX310X_TXFIFOLVL_REG:
+	case MAX310X_RXFIFOLVL_REG:
+		return false;
+	default:
+		break;
+	}
+
+	return true;
+}
+
+static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX310X_RHR_REG:
+	case MAX310X_IRQSTS_REG:
+	case MAX310X_LSR_IRQSTS_REG:
+	case MAX310X_SPCHR_IRQSTS_REG:
+	case MAX310X_STS_IRQSTS_REG:
+	case MAX310X_TXFIFOLVL_REG:
+	case MAX310X_RXFIFOLVL_REG:
+	case MAX310X_GPIODATA_REG:
+	case MAX310X_BRGDIVLSB_REG:
+	case MAX310X_REG_05:
+	case MAX310X_REG_1F:
+		return true;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static bool max310x_reg_precious(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX310X_RHR_REG:
+	case MAX310X_IRQSTS_REG:
+	case MAX310X_SPCHR_IRQSTS_REG:
+	case MAX310X_STS_IRQSTS_REG:
+		return true;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static bool max310x_reg_noinc(struct device *dev, unsigned int reg)
+{
+	return reg == MAX310X_RHR_REG;
+}
+
+static int max310x_set_baud(struct uart_port *port, int baud)
+{
+	unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
+
+	/*
+	 * Calculate the integer divisor first. Select a proper mode
+	 * in case if the requested baud is too high for the pre-defined
+	 * clocks frequency.
+	 */
+	div = port->uartclk / baud;
+	if (div < 8) {
+		/* Mode x4 */
+		c = 4;
+		mode = MAX310X_BRGCFG_4XMODE_BIT;
+	} else if (div < 16) {
+		/* Mode x2 */
+		c = 8;
+		mode = MAX310X_BRGCFG_2XMODE_BIT;
+	} else {
+		c = 16;
+	}
+
+	/* Calculate the divisor in accordance with the fraction coefficient */
+	div /= c;
+	F = c*baud;
+
+	/* Calculate the baud rate fraction */
+	if (div > 0)
+		frac = (16*(port->uartclk % F)) / F;
+	else
+		div = 1;
+
+	max310x_port_write(port, MAX310X_BRGDIVMSB_REG, div >> 8);
+	max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div);
+	max310x_port_write(port, MAX310X_BRGCFG_REG, frac | mode);
+
+	/* Return the actual baud rate we just programmed */
+	return (16*port->uartclk) / (c*(16*div + frac));
+}
+
+static int max310x_update_best_err(unsigned long f, long *besterr)
+{
+	/* Use baudrate 115200 for calculate error */
+	long err = f % (460800 * 16);
+
+	if ((*besterr < 0) || (*besterr > err)) {
+		*besterr = err;
+		return 0;
+	}
+
+	return 1;
+}
+
+static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
+			       unsigned long freq, bool xtal)
+{
+	unsigned int div, clksrc, pllcfg = 0;
+	long besterr = -1;
+	unsigned long fdiv, fmul, bestfreq = freq;
+
+	/* First, update error without PLL */
+	max310x_update_best_err(freq, &besterr);
+
+	/* Try all possible PLL dividers */
+	for (div = 1; (div <= 63) && besterr; div++) {
+		fdiv = DIV_ROUND_CLOSEST(freq, div);
+
+		/* Try multiplier 6 */
+		fmul = fdiv * 6;
+		if ((fdiv >= 500000) && (fdiv <= 800000))
+			if (!max310x_update_best_err(fmul, &besterr)) {
+				pllcfg = (0 << 6) | div;
+				bestfreq = fmul;
+			}
+		/* Try multiplier 48 */
+		fmul = fdiv * 48;
+		if ((fdiv >= 850000) && (fdiv <= 1200000))
+			if (!max310x_update_best_err(fmul, &besterr)) {
+				pllcfg = (1 << 6) | div;
+				bestfreq = fmul;
+			}
+		/* Try multiplier 96 */
+		fmul = fdiv * 96;
+		if ((fdiv >= 425000) && (fdiv <= 1000000))
+			if (!max310x_update_best_err(fmul, &besterr)) {
+				pllcfg = (2 << 6) | div;
+				bestfreq = fmul;
+			}
+		/* Try multiplier 144 */
+		fmul = fdiv * 144;
+		if ((fdiv >= 390000) && (fdiv <= 667000))
+			if (!max310x_update_best_err(fmul, &besterr)) {
+				pllcfg = (3 << 6) | div;
+				bestfreq = fmul;
+			}
+	}
+
+	/* Configure clock source */
+	clksrc = MAX310X_CLKSRC_EXTCLK_BIT | (xtal ? MAX310X_CLKSRC_CRYST_BIT : 0);
+
+	/* Configure PLL */
+	if (pllcfg) {
+		clksrc |= MAX310X_CLKSRC_PLL_BIT;
+		regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
+	} else
+		clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
+
+	regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
+
+	/* Wait for crystal */
+	if (xtal) {
+		unsigned int val;
+		msleep(10);
+		regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
+		if (!(val & MAX310X_STS_CLKREADY_BIT)) {
+			dev_warn(dev, "clock is not stable yet\n");
+		}
+	}
+
+	return bestfreq;
+}
+
+static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	regmap_noinc_write(one->regmap, MAX310X_THR_REG, txbuf, len);
+}
+
+static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	regmap_noinc_read(one->regmap, MAX310X_RHR_REG, rxbuf, len);
+}
+
+static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
+{
+	struct max310x_one *one = to_max310x_port(port);
+	unsigned int sts, i;
+	u8 ch, flag;
+
+	if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
+		/* We are just reading, happily ignoring any error conditions.
+		 * Break condition, parity checking, framing errors -- they
+		 * are all ignored. That means that we can do a batch-read.
+		 *
+		 * There is a small opportunity for race if the RX FIFO
+		 * overruns while we're reading the buffer; the datasheets says
+		 * that the LSR register applies to the "current" character.
+		 * That's also the reason why we cannot do batched reads when
+		 * asked to check the individual statuses.
+		 * */
+
+		sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
+		max310x_batch_read(port, one->rx_buf, rxlen);
+
+		port->icount.rx += rxlen;
+		flag = TTY_NORMAL;
+		sts &= port->read_status_mask;
+
+		if (sts & MAX310X_LSR_RXOVR_BIT) {
+			dev_warn_ratelimited(port->dev, "Hardware RX FIFO overrun\n");
+			port->icount.overrun++;
+		}
+
+		for (i = 0; i < (rxlen - 1); ++i)
+			uart_insert_char(port, sts, 0, one->rx_buf[i], flag);
+
+		/*
+		 * Handle the overrun case for the last character only, since
+		 * the RxFIFO overflow happens after it is pushed to the FIFO
+		 * tail.
+		 */
+		uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT,
+				 one->rx_buf[rxlen-1], flag);
+
+	} else {
+		if (unlikely(rxlen >= port->fifosize)) {
+			dev_warn_ratelimited(port->dev, "Possible RX FIFO overrun\n");
+			port->icount.buf_overrun++;
+			/* Ensure sanity of RX level */
+			rxlen = port->fifosize;
+		}
+
+		while (rxlen--) {
+			ch = max310x_port_read(port, MAX310X_RHR_REG);
+			sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
+
+			sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
+			       MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
+
+			port->icount.rx++;
+			flag = TTY_NORMAL;
+
+			if (unlikely(sts)) {
+				if (sts & MAX310X_LSR_RXBRK_BIT) {
+					port->icount.brk++;
+					if (uart_handle_break(port))
+						continue;
+				} else if (sts & MAX310X_LSR_RXPAR_BIT)
+					port->icount.parity++;
+				else if (sts & MAX310X_LSR_FRERR_BIT)
+					port->icount.frame++;
+				else if (sts & MAX310X_LSR_RXOVR_BIT)
+					port->icount.overrun++;
+
+				sts &= port->read_status_mask;
+				if (sts & MAX310X_LSR_RXBRK_BIT)
+					flag = TTY_BREAK;
+				else if (sts & MAX310X_LSR_RXPAR_BIT)
+					flag = TTY_PARITY;
+				else if (sts & MAX310X_LSR_FRERR_BIT)
+					flag = TTY_FRAME;
+				else if (sts & MAX310X_LSR_RXOVR_BIT)
+					flag = TTY_OVERRUN;
+			}
+
+			if (uart_handle_sysrq_char(port, ch))
+				continue;
+
+			if (sts & port->ignore_status_mask)
+				continue;
+
+			uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
+		}
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void max310x_handle_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int txlen, to_send, until_end;
+
+	if (unlikely(port->x_char)) {
+		max310x_port_write(port, MAX310X_THR_REG, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return;
+
+	/* Get length of data pending in circular buffer */
+	to_send = uart_circ_chars_pending(xmit);
+	until_end = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (likely(to_send)) {
+		/* Limit to size of TX FIFO */
+		txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
+		txlen = port->fifosize - txlen;
+		to_send = (to_send > txlen) ? txlen : to_send;
+
+		if (until_end < to_send) {
+			/* It's a circ buffer -- wrap around.
+			 * We could do that in one SPI transaction, but meh. */
+			max310x_batch_write(port, xmit->buf + xmit->tail, until_end);
+			max310x_batch_write(port, xmit->buf, to_send - until_end);
+		} else {
+			max310x_batch_write(port, xmit->buf + xmit->tail, to_send);
+		}
+		uart_xmit_advance(port, to_send);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static void max310x_start_tx(struct uart_port *port)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	schedule_work(&one->tx_work);
+}
+
+static irqreturn_t max310x_port_irq(struct max310x_port *s, int portno)
+{
+	struct uart_port *port = &s->p[portno].port;
+	irqreturn_t res = IRQ_NONE;
+
+	do {
+		unsigned int ists, lsr, rxlen;
+
+		/* Read IRQ status & RX FIFO level */
+		ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
+		rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
+		if (!ists && !rxlen)
+			break;
+
+		res = IRQ_HANDLED;
+
+		if (ists & MAX310X_IRQ_CTS_BIT) {
+			lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
+			uart_handle_cts_change(port, lsr & MAX310X_LSR_CTS_BIT);
+		}
+		if (rxlen)
+			max310x_handle_rx(port, rxlen);
+		if (ists & MAX310X_IRQ_TXEMPTY_BIT)
+			max310x_start_tx(port);
+	} while (1);
+	return res;
+}
+
+static irqreturn_t max310x_ist(int irq, void *dev_id)
+{
+	struct max310x_port *s = (struct max310x_port *)dev_id;
+	bool handled = false;
+
+	if (s->devtype->nr > 1) {
+		do {
+			unsigned int val = ~0;
+
+			WARN_ON_ONCE(regmap_read(s->regmap,
+						 MAX310X_GLOBALIRQ_REG, &val));
+			val = ((1 << s->devtype->nr) - 1) & ~val;
+			if (!val)
+				break;
+			if (max310x_port_irq(s, fls(val) - 1) == IRQ_HANDLED)
+				handled = true;
+		} while (1);
+	} else {
+		if (max310x_port_irq(s, 0) == IRQ_HANDLED)
+			handled = true;
+	}
+
+	return IRQ_RETVAL(handled);
+}
+
+static void max310x_tx_proc(struct work_struct *ws)
+{
+	struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
+
+	max310x_handle_tx(&one->port);
+}
+
+static unsigned int max310x_tx_empty(struct uart_port *port)
+{
+	u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
+
+	return lvl ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int max310x_get_mctrl(struct uart_port *port)
+{
+	/* DCD and DSR are not wired and CTS/RTS is handled automatically
+	 * so just indicate DSR and CAR asserted
+	 */
+	return TIOCM_DSR | TIOCM_CAR;
+}
+
+static void max310x_md_proc(struct work_struct *ws)
+{
+	struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
+
+	max310x_port_update(&one->port, MAX310X_MODE2_REG,
+			    MAX310X_MODE2_LOOPBACK_BIT,
+			    (one->port.mctrl & TIOCM_LOOP) ?
+			    MAX310X_MODE2_LOOPBACK_BIT : 0);
+}
+
+static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	schedule_work(&one->md_work);
+}
+
+static void max310x_break_ctl(struct uart_port *port, int break_state)
+{
+	max310x_port_update(port, MAX310X_LCR_REG,
+			    MAX310X_LCR_TXBREAK_BIT,
+			    break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
+}
+
+static void max310x_set_termios(struct uart_port *port,
+				struct ktermios *termios,
+				const struct ktermios *old)
+{
+	unsigned int lcr = 0, flow = 0;
+	int baud;
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+
+	/* Word size */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		break;
+	case CS6:
+		lcr = MAX310X_LCR_LENGTH0_BIT;
+		break;
+	case CS7:
+		lcr = MAX310X_LCR_LENGTH1_BIT;
+		break;
+	case CS8:
+	default:
+		lcr = MAX310X_LCR_LENGTH1_BIT | MAX310X_LCR_LENGTH0_BIT;
+		break;
+	}
+
+	/* Parity */
+	if (termios->c_cflag & PARENB) {
+		lcr |= MAX310X_LCR_PARITY_BIT;
+		if (!(termios->c_cflag & PARODD))
+			lcr |= MAX310X_LCR_EVENPARITY_BIT;
+	}
+
+	/* Stop bits */
+	if (termios->c_cflag & CSTOPB)
+		lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
+
+	/* Update LCR register */
+	max310x_port_write(port, MAX310X_LCR_REG, lcr);
+
+	/* Set read status mask */
+	port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
+					  MAX310X_LSR_FRERR_BIT;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNBRK)
+		port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
+					    MAX310X_LSR_RXOVR_BIT |
+					    MAX310X_LSR_FRERR_BIT |
+					    MAX310X_LSR_RXBRK_BIT;
+
+	/* Configure flow control */
+	max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
+	max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
+
+	/* Disable transmitter before enabling AutoCTS or auto transmitter
+	 * flow control
+	 */
+	if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) {
+		max310x_port_update(port, MAX310X_MODE1_REG,
+				    MAX310X_MODE1_TXDIS_BIT,
+				    MAX310X_MODE1_TXDIS_BIT);
+	}
+
+	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
+
+	if (termios->c_cflag & CRTSCTS) {
+		/* Enable AUTORTS and AUTOCTS */
+		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+		flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
+			MAX310X_FLOWCTRL_AUTORTS_BIT;
+	}
+	if (termios->c_iflag & IXON)
+		flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
+			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
+	if (termios->c_iflag & IXOFF) {
+		port->status |= UPSTAT_AUTOXOFF;
+		flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
+			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
+	}
+	max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
+
+	/* Enable transmitter after disabling AutoCTS and auto transmitter
+	 * flow control
+	 */
+	if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) {
+		max310x_port_update(port, MAX310X_MODE1_REG,
+				    MAX310X_MODE1_TXDIS_BIT,
+				    0);
+	}
+
+	/* Get baud rate generator configuration */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / 16 / 0xffff,
+				  port->uartclk / 4);
+
+	/* Setup baudrate generator */
+	baud = max310x_set_baud(port, baud);
+
+	/* Update timeout according to new baud rate */
+	uart_update_timeout(port, termios->c_cflag, baud);
+}
+
+static void max310x_rs_proc(struct work_struct *ws)
+{
+	struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
+	unsigned int delay, mode1 = 0, mode2 = 0;
+
+	delay = (one->port.rs485.delay_rts_before_send << 4) |
+		one->port.rs485.delay_rts_after_send;
+	max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, delay);
+
+	if (one->port.rs485.flags & SER_RS485_ENABLED) {
+		mode1 = MAX310X_MODE1_TRNSCVCTRL_BIT;
+
+		if (!(one->port.rs485.flags & SER_RS485_RX_DURING_TX))
+			mode2 = MAX310X_MODE2_ECHOSUPR_BIT;
+	}
+
+	max310x_port_update(&one->port, MAX310X_MODE1_REG,
+			MAX310X_MODE1_TRNSCVCTRL_BIT, mode1);
+	max310x_port_update(&one->port, MAX310X_MODE2_REG,
+			MAX310X_MODE2_ECHOSUPR_BIT, mode2);
+}
+
+static int max310x_rs485_config(struct uart_port *port, struct ktermios *termios,
+				struct serial_rs485 *rs485)
+{
+	struct max310x_one *one = to_max310x_port(port);
+
+	if ((rs485->delay_rts_before_send > 0x0f) ||
+	    (rs485->delay_rts_after_send > 0x0f))
+		return -ERANGE;
+
+	port->rs485 = *rs485;
+
+	schedule_work(&one->rs_work);
+
+	return 0;
+}
+
+static int max310x_startup(struct uart_port *port)
+{
+	struct max310x_port *s = dev_get_drvdata(port->dev);
+	unsigned int val;
+
+	s->devtype->power(port, 1);
+
+	/* Configure MODE1 register */
+	max310x_port_update(port, MAX310X_MODE1_REG,
+			    MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
+
+	/* Configure MODE2 register & Reset FIFOs*/
+	val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
+	max310x_port_write(port, MAX310X_MODE2_REG, val);
+	max310x_port_update(port, MAX310X_MODE2_REG,
+			    MAX310X_MODE2_FIFORST_BIT, 0);
+
+	/* Configure mode1/mode2 to have rs485/rs232 enabled at startup */
+	val = (clamp(port->rs485.delay_rts_before_send, 0U, 15U) << 4) |
+		clamp(port->rs485.delay_rts_after_send, 0U, 15U);
+	max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
+
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		max310x_port_update(port, MAX310X_MODE1_REG,
+				    MAX310X_MODE1_TRNSCVCTRL_BIT,
+				    MAX310X_MODE1_TRNSCVCTRL_BIT);
+
+		if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+			max310x_port_update(port, MAX310X_MODE2_REG,
+					    MAX310X_MODE2_ECHOSUPR_BIT,
+					    MAX310X_MODE2_ECHOSUPR_BIT);
+	}
+
+	/* Configure flow control levels */
+	/* Flow control halt level 96, resume level 48 */
+	max310x_port_write(port, MAX310X_FLOWLVL_REG,
+			   MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
+
+	/* Clear IRQ status register */
+	max310x_port_read(port, MAX310X_IRQSTS_REG);
+
+	/* Enable RX, TX, CTS change interrupts */
+	val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
+	max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
+
+	return 0;
+}
+
+static void max310x_shutdown(struct uart_port *port)
+{
+	struct max310x_port *s = dev_get_drvdata(port->dev);
+
+	/* Disable all interrupts */
+	max310x_port_write(port, MAX310X_IRQEN_REG, 0);
+
+	s->devtype->power(port, 0);
+}
+
+static const char *max310x_type(struct uart_port *port)
+{
+	struct max310x_port *s = dev_get_drvdata(port->dev);
+
+	return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
+}
+
+static int max310x_request_port(struct uart_port *port)
+{
+	/* Do nothing */
+	return 0;
+}
+
+static void max310x_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_MAX310X;
+}
+
+static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
+{
+	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
+		return -EINVAL;
+	if (s->irq != port->irq)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void max310x_null_void(struct uart_port *port)
+{
+	/* Do nothing */
+}
+
+static const struct uart_ops max310x_ops = {
+	.tx_empty	= max310x_tx_empty,
+	.set_mctrl	= max310x_set_mctrl,
+	.get_mctrl	= max310x_get_mctrl,
+	.stop_tx	= max310x_null_void,
+	.start_tx	= max310x_start_tx,
+	.stop_rx	= max310x_null_void,
+	.break_ctl	= max310x_break_ctl,
+	.startup	= max310x_startup,
+	.shutdown	= max310x_shutdown,
+	.set_termios	= max310x_set_termios,
+	.type		= max310x_type,
+	.request_port	= max310x_request_port,
+	.release_port	= max310x_null_void,
+	.config_port	= max310x_config_port,
+	.verify_port	= max310x_verify_port,
+};
+
+static int __maybe_unused max310x_suspend(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	int i;
+
+	for (i = 0; i < s->devtype->nr; i++) {
+		uart_suspend_port(&max310x_uart, &s->p[i].port);
+		s->devtype->power(&s->p[i].port, 0);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused max310x_resume(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	int i;
+
+	for (i = 0; i < s->devtype->nr; i++) {
+		s->devtype->power(&s->p[i].port, 1);
+		uart_resume_port(&max310x_uart, &s->p[i].port);
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
+
+#ifdef CONFIG_GPIOLIB
+static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	unsigned int val;
+	struct max310x_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[offset / 4].port;
+
+	val = max310x_port_read(port, MAX310X_GPIODATA_REG);
+
+	return !!((val >> 4) & (1 << (offset % 4)));
+}
+
+static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct max310x_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[offset / 4].port;
+
+	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
+			    value ? 1 << (offset % 4) : 0);
+}
+
+static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct max310x_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[offset / 4].port;
+
+	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
+
+	return 0;
+}
+
+static int max310x_gpio_direction_output(struct gpio_chip *chip,
+					 unsigned offset, int value)
+{
+	struct max310x_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[offset / 4].port;
+
+	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
+			    value ? 1 << (offset % 4) : 0);
+	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
+			    1 << (offset % 4));
+
+	return 0;
+}
+
+static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
+				   unsigned long config)
+{
+	struct max310x_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[offset / 4].port;
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		max310x_port_update(port, MAX310X_GPIOCFG_REG,
+				1 << ((offset % 4) + 4),
+				1 << ((offset % 4) + 4));
+		return 0;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		max310x_port_update(port, MAX310X_GPIOCFG_REG,
+				1 << ((offset % 4) + 4), 0);
+		return 0;
+	default:
+		return -ENOTSUPP;
+	}
+}
+#endif
+
+static const struct serial_rs485 max310x_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
+			 const struct max310x_if_cfg *if_cfg,
+			 struct regmap *regmaps[], int irq)
+{
+	int i, ret, fmin, fmax, freq;
+	struct max310x_port *s;
+	u32 uartclk = 0;
+	bool xtal;
+
+	for (i = 0; i < devtype->nr; i++)
+		if (IS_ERR(regmaps[i]))
+			return PTR_ERR(regmaps[i]);
+
+	/* Alloc port structure */
+	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
+	if (!s) {
+		dev_err(dev, "Error allocating port structure\n");
+		return -ENOMEM;
+	}
+
+	/* Always ask for fixed clock rate from a property. */
+	device_property_read_u32(dev, "clock-frequency", &uartclk);
+
+	xtal = device_property_match_string(dev, "clock-names", "osc") < 0;
+	if (xtal)
+		s->clk = devm_clk_get_optional(dev, "xtal");
+	else
+		s->clk = devm_clk_get_optional(dev, "osc");
+	if (IS_ERR(s->clk))
+		return PTR_ERR(s->clk);
+
+	ret = clk_prepare_enable(s->clk);
+	if (ret)
+		return ret;
+
+	freq = clk_get_rate(s->clk);
+	if (freq == 0)
+		freq = uartclk;
+	if (freq == 0) {
+		dev_err(dev, "Cannot get clock rate\n");
+		ret = -EINVAL;
+		goto out_clk;
+	}
+
+	if (xtal) {
+		fmin = 1000000;
+		fmax = 4000000;
+	} else {
+		fmin = 500000;
+		fmax = 35000000;
+	}
+
+	/* Check frequency limits */
+	if (freq < fmin || freq > fmax) {
+		ret = -ERANGE;
+		goto out_clk;
+	}
+
+	s->regmap = regmaps[0];
+	s->devtype = devtype;
+	s->if_cfg = if_cfg;
+	dev_set_drvdata(dev, s);
+
+	/* Check device to ensure we are talking to what we expect */
+	ret = devtype->detect(dev);
+	if (ret)
+		goto out_clk;
+
+	for (i = 0; i < devtype->nr; i++) {
+		/* Reset port */
+		regmap_write(regmaps[i], MAX310X_MODE2_REG,
+			     MAX310X_MODE2_RST_BIT);
+		/* Clear port reset */
+		regmap_write(regmaps[i], MAX310X_MODE2_REG, 0);
+
+		/* Wait for port startup */
+		do {
+			regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &ret);
+		} while (ret != 0x01);
+
+		regmap_write(regmaps[i], MAX310X_MODE1_REG, devtype->mode1);
+	}
+
+	uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
+	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
+
+	for (i = 0; i < devtype->nr; i++) {
+		unsigned int line;
+
+		line = find_first_zero_bit(max310x_lines, MAX310X_UART_NRMAX);
+		if (line == MAX310X_UART_NRMAX) {
+			ret = -ERANGE;
+			goto out_uart;
+		}
+
+		/* Initialize port data */
+		s->p[i].port.line	= line;
+		s->p[i].port.dev	= dev;
+		s->p[i].port.irq	= irq;
+		s->p[i].port.type	= PORT_MAX310X;
+		s->p[i].port.fifosize	= MAX310X_FIFO_SIZE;
+		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
+		s->p[i].port.iotype	= UPIO_PORT;
+		s->p[i].port.iobase	= i;
+		/*
+		 * Use all ones as membase to make sure uart_configure_port() in
+		 * serial_core.c does not abort for SPI/I2C devices where the
+		 * membase address is not applicable.
+		 */
+		s->p[i].port.membase	= (void __iomem *)~0;
+		s->p[i].port.uartclk	= uartclk;
+		s->p[i].port.rs485_config = max310x_rs485_config;
+		s->p[i].port.rs485_supported = max310x_rs485_supported;
+		s->p[i].port.ops	= &max310x_ops;
+		s->p[i].regmap		= regmaps[i];
+
+		/* Disable all interrupts */
+		max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
+		/* Clear IRQ status register */
+		max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
+		/* Initialize queue for start TX */
+		INIT_WORK(&s->p[i].tx_work, max310x_tx_proc);
+		/* Initialize queue for changing LOOPBACK mode */
+		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
+		/* Initialize queue for changing RS485 mode */
+		INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
+
+		/* Register port */
+		ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
+		if (ret) {
+			s->p[i].port.dev = NULL;
+			goto out_uart;
+		}
+		set_bit(line, max310x_lines);
+
+		/* Go to suspend mode */
+		devtype->power(&s->p[i].port, 0);
+	}
+
+#ifdef CONFIG_GPIOLIB
+	/* Setup GPIO controller */
+	s->gpio.owner		= THIS_MODULE;
+	s->gpio.parent		= dev;
+	s->gpio.label		= devtype->name;
+	s->gpio.direction_input	= max310x_gpio_direction_input;
+	s->gpio.get		= max310x_gpio_get;
+	s->gpio.direction_output= max310x_gpio_direction_output;
+	s->gpio.set		= max310x_gpio_set;
+	s->gpio.set_config	= max310x_gpio_set_config;
+	s->gpio.base		= -1;
+	s->gpio.ngpio		= devtype->nr * 4;
+	s->gpio.can_sleep	= 1;
+	ret = devm_gpiochip_add_data(dev, &s->gpio, s);
+	if (ret)
+		goto out_uart;
+#endif
+
+	/* Setup interrupt */
+	ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
+					IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), s);
+	if (!ret)
+		return 0;
+
+	dev_err(dev, "Unable to reguest IRQ %i\n", irq);
+
+out_uart:
+	for (i = 0; i < devtype->nr; i++) {
+		if (s->p[i].port.dev) {
+			uart_remove_one_port(&max310x_uart, &s->p[i].port);
+			clear_bit(s->p[i].port.line, max310x_lines);
+		}
+	}
+
+out_clk:
+	clk_disable_unprepare(s->clk);
+
+	return ret;
+}
+
+static void max310x_remove(struct device *dev)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+	int i;
+
+	for (i = 0; i < s->devtype->nr; i++) {
+		cancel_work_sync(&s->p[i].tx_work);
+		cancel_work_sync(&s->p[i].md_work);
+		cancel_work_sync(&s->p[i].rs_work);
+		uart_remove_one_port(&max310x_uart, &s->p[i].port);
+		clear_bit(s->p[i].port.line, max310x_lines);
+		s->devtype->power(&s->p[i].port, 0);
+	}
+
+	clk_disable_unprepare(s->clk);
+}
+
+static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
+	{ .compatible = "maxim,max3107",	.data = &max3107_devtype, },
+	{ .compatible = "maxim,max3108",	.data = &max3108_devtype, },
+	{ .compatible = "maxim,max3109",	.data = &max3109_devtype, },
+	{ .compatible = "maxim,max14830",	.data = &max14830_devtype },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max310x_dt_ids);
+
+static struct regmap_config regcfg = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.write_flag_mask = MAX310X_WRITE_BIT,
+	.cache_type = REGCACHE_RBTREE,
+	.max_register = MAX310X_REG_1F,
+	.writeable_reg = max310x_reg_writeable,
+	.volatile_reg = max310x_reg_volatile,
+	.precious_reg = max310x_reg_precious,
+	.writeable_noinc_reg = max310x_reg_noinc,
+	.readable_noinc_reg = max310x_reg_noinc,
+	.max_raw_read = MAX310X_FIFO_SIZE,
+	.max_raw_write = MAX310X_FIFO_SIZE,
+};
+
+#ifdef CONFIG_SPI_MASTER
+static int max310x_spi_extended_reg_enable(struct device *dev, bool enable)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+
+	return regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
+			    enable ? MAX310X_EXTREG_ENBL : MAX310X_EXTREG_DSBL);
+}
+
+static const struct max310x_if_cfg __maybe_unused max310x_spi_if_cfg = {
+	.extended_reg_enable = max310x_spi_extended_reg_enable,
+	.rev_id_reg = MAX310X_SPI_REVID_EXTREG,
+};
+
+static int max310x_spi_probe(struct spi_device *spi)
+{
+	const struct max310x_devtype *devtype;
+	struct regmap *regmaps[4];
+	unsigned int i;
+	int ret;
+
+	/* Setup SPI bus */
+	spi->bits_per_word	= 8;
+	spi->mode		= spi->mode ? : SPI_MODE_0;
+	spi->max_speed_hz	= spi->max_speed_hz ? : 26000000;
+	ret = spi_setup(spi);
+	if (ret)
+		return ret;
+
+	devtype = device_get_match_data(&spi->dev);
+	if (!devtype)
+		devtype = (struct max310x_devtype *)spi_get_device_id(spi)->driver_data;
+
+	for (i = 0; i < devtype->nr; i++) {
+		u8 port_mask = i * 0x20;
+		regcfg.read_flag_mask = port_mask;
+		regcfg.write_flag_mask = port_mask | MAX310X_WRITE_BIT;
+		regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
+	}
+
+	return max310x_probe(&spi->dev, devtype, &max310x_spi_if_cfg, regmaps, spi->irq);
+}
+
+static void max310x_spi_remove(struct spi_device *spi)
+{
+	max310x_remove(&spi->dev);
+}
+
+static const struct spi_device_id max310x_id_table[] = {
+	{ "max3107",	(kernel_ulong_t)&max3107_devtype, },
+	{ "max3108",	(kernel_ulong_t)&max3108_devtype, },
+	{ "max3109",	(kernel_ulong_t)&max3109_devtype, },
+	{ "max14830",	(kernel_ulong_t)&max14830_devtype, },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, max310x_id_table);
+
+static struct spi_driver max310x_spi_driver = {
+	.driver = {
+		.name		= MAX310X_NAME,
+		.of_match_table	= max310x_dt_ids,
+		.pm		= &max310x_pm_ops,
+	},
+	.probe		= max310x_spi_probe,
+	.remove		= max310x_spi_remove,
+	.id_table	= max310x_id_table,
+};
+#endif
+
+#ifdef CONFIG_I2C
+static int max310x_i2c_extended_reg_enable(struct device *dev, bool enable)
+{
+	return 0;
+}
+
+static struct regmap_config regcfg_i2c = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_RBTREE,
+	.writeable_reg = max310x_reg_writeable,
+	.volatile_reg = max310x_reg_volatile,
+	.precious_reg = max310x_reg_precious,
+	.max_register = MAX310X_I2C_REVID_EXTREG,
+	.writeable_noinc_reg = max310x_reg_noinc,
+	.readable_noinc_reg = max310x_reg_noinc,
+	.max_raw_read = MAX310X_FIFO_SIZE,
+	.max_raw_write = MAX310X_FIFO_SIZE,
+};
+
+static const struct max310x_if_cfg max310x_i2c_if_cfg = {
+	.extended_reg_enable = max310x_i2c_extended_reg_enable,
+	.rev_id_reg = MAX310X_I2C_REVID_EXTREG,
+};
+
+static unsigned short max310x_i2c_slave_addr(unsigned short addr,
+					     unsigned int nr)
+{
+	/*
+	 * For MAX14830 and MAX3109, the slave address depends on what the
+	 * A0 and A1 pins are tied to.
+	 * See Table I2C Address Map of the datasheet.
+	 * Based on that table, the following formulas were determined.
+	 * UART1 - UART0 = 0x10
+	 * UART2 - UART1 = 0x20 + 0x10
+	 * UART3 - UART2 = 0x10
+	 */
+
+	addr -= nr * 0x10;
+
+	if (nr >= 2)
+		addr -= 0x20;
+
+	return addr;
+}
+
+static int max310x_i2c_probe(struct i2c_client *client)
+{
+	const struct max310x_devtype *devtype =
+			device_get_match_data(&client->dev);
+	struct i2c_client *port_client;
+	struct regmap *regmaps[4];
+	unsigned int i;
+	u8 port_addr;
+
+	if (client->addr < devtype->slave_addr.min ||
+		client->addr > devtype->slave_addr.max)
+		return dev_err_probe(&client->dev, -EINVAL,
+				     "Slave addr 0x%x outside of range [0x%x, 0x%x]\n",
+				     client->addr, devtype->slave_addr.min,
+				     devtype->slave_addr.max);
+
+	regmaps[0] = devm_regmap_init_i2c(client, &regcfg_i2c);
+
+	for (i = 1; i < devtype->nr; i++) {
+		port_addr = max310x_i2c_slave_addr(client->addr, i);
+		port_client = devm_i2c_new_dummy_device(&client->dev,
+							client->adapter,
+							port_addr);
+
+		regmaps[i] = devm_regmap_init_i2c(port_client, &regcfg_i2c);
+	}
+
+	return max310x_probe(&client->dev, devtype, &max310x_i2c_if_cfg,
+			     regmaps, client->irq);
+}
+
+static void max310x_i2c_remove(struct i2c_client *client)
+{
+	max310x_remove(&client->dev);
+}
+
+static struct i2c_driver max310x_i2c_driver = {
+	.driver = {
+		.name		= MAX310X_NAME,
+		.of_match_table	= max310x_dt_ids,
+		.pm		= &max310x_pm_ops,
+	},
+	.probe		= max310x_i2c_probe,
+	.remove		= max310x_i2c_remove,
+};
+#endif
+
+static int __init max310x_uart_init(void)
+{
+	int ret;
+
+	bitmap_zero(max310x_lines, MAX310X_UART_NRMAX);
+
+	ret = uart_register_driver(&max310x_uart);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_SPI_MASTER
+	ret = spi_register_driver(&max310x_spi_driver);
+	if (ret)
+		goto err_spi_register;
+#endif
+
+#ifdef CONFIG_I2C
+	ret = i2c_add_driver(&max310x_i2c_driver);
+	if (ret)
+		goto err_i2c_register;
+#endif
+
+	return 0;
+
+#ifdef CONFIG_I2C
+err_i2c_register:
+	spi_unregister_driver(&max310x_spi_driver);
+#endif
+
+err_spi_register:
+	uart_unregister_driver(&max310x_uart);
+
+	return ret;
+}
+module_init(max310x_uart_init);
+
+static void __exit max310x_uart_exit(void)
+{
+#ifdef CONFIG_I2C
+	i2c_del_driver(&max310x_i2c_driver);
+#endif
+
+#ifdef CONFIG_SPI_MASTER
+	spi_unregister_driver(&max310x_spi_driver);
+#endif
+
+	uart_unregister_driver(&max310x_uart);
+}
+module_exit(max310x_uart_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("MAX310X serial driver");
diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
new file mode 100644
index 000000000..1666ce012
--- /dev/null
+++ b/drivers/tty/serial/mcf.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0+
+/****************************************************************************/
+
+/*
+ *	mcf.c -- Freescale ColdFire UART driver
+ *
+ *	(C) Copyright 2003-2007, Greg Ungerer <gerg@uclinux.org>
+ */
+
+/****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <asm/coldfire.h>
+#include <asm/mcfsim.h>
+#include <asm/mcfuart.h>
+#include <asm/nettel.h>
+
+/****************************************************************************/
+
+/*
+ *	Some boards implement the DTR/DCD lines using GPIO lines, most
+ *	don't. Dummy out the access macros for those that don't. Those
+ *	that do should define these macros somewhere in there board
+ *	specific inlude files.
+ */
+#if !defined(mcf_getppdcd)
+#define	mcf_getppdcd(p)		(1)
+#endif
+#if !defined(mcf_getppdtr)
+#define	mcf_getppdtr(p)		(1)
+#endif
+#if !defined(mcf_setppdtr)
+#define	mcf_setppdtr(p, v)	do { } while (0)
+#endif
+
+/****************************************************************************/
+
+/*
+ *	Local per-uart structure.
+ */
+struct mcf_uart {
+	struct uart_port	port;
+	unsigned int		sigs;		/* Local copy of line sigs */
+	unsigned char		imr;		/* Local IMR mirror */
+};
+
+/****************************************************************************/
+
+static unsigned int mcf_tx_empty(struct uart_port *port)
+{
+	return (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXEMPTY) ?
+		TIOCSER_TEMT : 0;
+}
+
+/****************************************************************************/
+
+static unsigned int mcf_get_mctrl(struct uart_port *port)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+	unsigned int sigs;
+
+	sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
+		0 : TIOCM_CTS;
+	sigs |= (pp->sigs & TIOCM_RTS);
+	sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
+	sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
+
+	return sigs;
+}
+
+/****************************************************************************/
+
+static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+
+	pp->sigs = sigs;
+	mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
+	if (sigs & TIOCM_RTS)
+		writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
+	else
+		writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
+}
+
+/****************************************************************************/
+
+static void mcf_start_tx(struct uart_port *port)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		/* Enable Transmitter */
+		writeb(MCFUART_UCR_TXENABLE, port->membase + MCFUART_UCR);
+		/* Manually assert RTS */
+		writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
+	}
+	pp->imr |= MCFUART_UIR_TXREADY;
+	writeb(pp->imr, port->membase + MCFUART_UIMR);
+}
+
+/****************************************************************************/
+
+static void mcf_stop_tx(struct uart_port *port)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+
+	pp->imr &= ~MCFUART_UIR_TXREADY;
+	writeb(pp->imr, port->membase + MCFUART_UIMR);
+}
+
+/****************************************************************************/
+
+static void mcf_stop_rx(struct uart_port *port)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+
+	pp->imr &= ~MCFUART_UIR_RXREADY;
+	writeb(pp->imr, port->membase + MCFUART_UIMR);
+}
+
+/****************************************************************************/
+
+static void mcf_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (break_state == -1)
+		writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
+	else
+		writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static int mcf_startup(struct uart_port *port)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Reset UART, get it into known state... */
+	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+
+	/* Enable the UART transmitter and receiver */
+	writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
+		port->membase + MCFUART_UCR);
+
+	/* Enable RX interrupts now */
+	pp->imr = MCFUART_UIR_RXREADY;
+	writeb(pp->imr, port->membase + MCFUART_UIMR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+/****************************************************************************/
+
+static void mcf_shutdown(struct uart_port *port)
+{
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable all interrupts now */
+	pp->imr = 0;
+	writeb(pp->imr, port->membase + MCFUART_UIMR);
+
+	/* Disable UART transmitter and receiver */
+	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
+			    const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, baudclk;
+#if defined(CONFIG_M5272)
+	unsigned int baudfr;
+#endif
+	unsigned char mr1, mr2;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, 230400);
+#if defined(CONFIG_M5272)
+	baudclk = (MCF_BUSCLK / baud) / 32;
+	baudfr = (((MCF_BUSCLK / baud) + 1) / 2) % 16;
+#else
+	baudclk = ((MCF_BUSCLK / baud) + 16) / 32;
+#endif
+
+	mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
+	mr2 = 0;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5: mr1 |= MCFUART_MR1_CS5; break;
+	case CS6: mr1 |= MCFUART_MR1_CS6; break;
+	case CS7: mr1 |= MCFUART_MR1_CS7; break;
+	case CS8:
+	default:  mr1 |= MCFUART_MR1_CS8; break;
+	}
+
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & CMSPAR) {
+			if (termios->c_cflag & PARODD)
+				mr1 |= MCFUART_MR1_PARITYMARK;
+			else
+				mr1 |= MCFUART_MR1_PARITYSPACE;
+		} else {
+			if (termios->c_cflag & PARODD)
+				mr1 |= MCFUART_MR1_PARITYODD;
+			else
+				mr1 |= MCFUART_MR1_PARITYEVEN;
+		}
+	} else {
+		mr1 |= MCFUART_MR1_PARITYNONE;
+	}
+
+	/*
+	 * FIXME: port->read_status_mask and port->ignore_status_mask
+	 * need to be initialized based on termios settings for
+	 * INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
+	 */
+
+	if (termios->c_cflag & CSTOPB)
+		mr2 |= MCFUART_MR2_STOP2;
+	else
+		mr2 |= MCFUART_MR2_STOP1;
+
+	if (termios->c_cflag & CRTSCTS) {
+		mr1 |= MCFUART_MR1_RXRTS;
+		mr2 |= MCFUART_MR2_TXCTS;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		dev_dbg(port->dev, "Setting UART to RS485\n");
+		mr2 |= MCFUART_MR2_TXRTS;
+	}
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
+	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
+	writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
+	writeb(mr1, port->membase + MCFUART_UMR);
+	writeb(mr2, port->membase + MCFUART_UMR);
+	writeb((baudclk & 0xff00) >> 8, port->membase + MCFUART_UBG1);
+	writeb((baudclk & 0xff), port->membase + MCFUART_UBG2);
+#if defined(CONFIG_M5272)
+	writeb((baudfr & 0x0f), port->membase + MCFUART_UFPD);
+#endif
+	writeb(MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER,
+		port->membase + MCFUART_UCSR);
+	writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
+		port->membase + MCFUART_UCR);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/****************************************************************************/
+
+static void mcf_rx_chars(struct mcf_uart *pp)
+{
+	struct uart_port *port = &pp->port;
+	u8 status, ch, flag;
+
+	while ((status = readb(port->membase + MCFUART_USR)) & MCFUART_USR_RXREADY) {
+		ch = readb(port->membase + MCFUART_URB);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (status & MCFUART_USR_RXERR) {
+			writeb(MCFUART_UCR_CMDRESETERR,
+				port->membase + MCFUART_UCR);
+
+			if (status & MCFUART_USR_RXBREAK) {
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			} else if (status & MCFUART_USR_RXPARITY) {
+				port->icount.parity++;
+			} else if (status & MCFUART_USR_RXOVERRUN) {
+				port->icount.overrun++;
+			} else if (status & MCFUART_USR_RXFRAMING) {
+				port->icount.frame++;
+			}
+
+			status &= port->read_status_mask;
+
+			if (status & MCFUART_USR_RXBREAK)
+				flag = TTY_BREAK;
+			else if (status & MCFUART_USR_RXPARITY)
+				flag = TTY_PARITY;
+			else if (status & MCFUART_USR_RXFRAMING)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+		uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+/****************************************************************************/
+
+static void mcf_tx_chars(struct mcf_uart *pp)
+{
+	struct uart_port *port = &pp->port;
+	bool pending;
+	u8 ch;
+
+	pending = uart_port_tx(port, ch,
+		readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY,
+		writeb(ch, port->membase + MCFUART_UTB));
+
+	/* Disable TX to negate RTS automatically */
+	if (!pending && (port->rs485.flags & SER_RS485_ENABLED))
+		writeb(MCFUART_UCR_TXDISABLE, port->membase + MCFUART_UCR);
+}
+
+/****************************************************************************/
+
+static irqreturn_t mcf_interrupt(int irq, void *data)
+{
+	struct uart_port *port = data;
+	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
+	unsigned int isr;
+	irqreturn_t ret = IRQ_NONE;
+
+	isr = readb(port->membase + MCFUART_UISR) & pp->imr;
+
+	spin_lock(&port->lock);
+	if (isr & MCFUART_UIR_RXREADY) {
+		mcf_rx_chars(pp);
+		ret = IRQ_HANDLED;
+	}
+	if (isr & MCFUART_UIR_TXREADY) {
+		mcf_tx_chars(pp);
+		ret = IRQ_HANDLED;
+	}
+	spin_unlock(&port->lock);
+
+	return ret;
+}
+
+/****************************************************************************/
+
+static void mcf_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_MCF;
+	port->fifosize = MCFUART_TXFIFOSIZE;
+
+	/* Clear mask, so no surprise interrupts. */
+	writeb(0, port->membase + MCFUART_UIMR);
+
+	if (request_irq(port->irq, mcf_interrupt, 0, "UART", port))
+		printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
+			"interrupt vector=%d\n", port->line, port->irq);
+}
+
+/****************************************************************************/
+
+static const char *mcf_type(struct uart_port *port)
+{
+	return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
+}
+
+/****************************************************************************/
+
+static int mcf_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+/****************************************************************************/
+
+static void mcf_release_port(struct uart_port *port)
+{
+	/* Nothing to release... */
+}
+
+/****************************************************************************/
+
+static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
+		return -EINVAL;
+	return 0;
+}
+
+/****************************************************************************/
+
+/* Enable or disable the RS485 support */
+static int mcf_config_rs485(struct uart_port *port, struct ktermios *termios,
+			    struct serial_rs485 *rs485)
+{
+	unsigned char mr1, mr2;
+
+	/* Get mode registers */
+	mr1 = readb(port->membase + MCFUART_UMR);
+	mr2 = readb(port->membase + MCFUART_UMR);
+	if (rs485->flags & SER_RS485_ENABLED) {
+		dev_dbg(port->dev, "Setting UART to RS485\n");
+		/* Automatically negate RTS after TX completes */
+		mr2 |= MCFUART_MR2_TXRTS;
+	} else {
+		dev_dbg(port->dev, "Setting UART to RS232\n");
+		mr2 &= ~MCFUART_MR2_TXRTS;
+	}
+	writeb(mr1, port->membase + MCFUART_UMR);
+	writeb(mr2, port->membase + MCFUART_UMR);
+
+	return 0;
+}
+
+static const struct serial_rs485 mcf_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
+};
+
+/****************************************************************************/
+
+/*
+ *	Define the basic serial functions we support.
+ */
+static const struct uart_ops mcf_uart_ops = {
+	.tx_empty	= mcf_tx_empty,
+	.get_mctrl	= mcf_get_mctrl,
+	.set_mctrl	= mcf_set_mctrl,
+	.start_tx	= mcf_start_tx,
+	.stop_tx	= mcf_stop_tx,
+	.stop_rx	= mcf_stop_rx,
+	.break_ctl	= mcf_break_ctl,
+	.startup	= mcf_startup,
+	.shutdown	= mcf_shutdown,
+	.set_termios	= mcf_set_termios,
+	.type		= mcf_type,
+	.request_port	= mcf_request_port,
+	.release_port	= mcf_release_port,
+	.config_port	= mcf_config_port,
+	.verify_port	= mcf_verify_port,
+};
+
+static struct mcf_uart mcf_ports[4];
+
+#define	MCF_MAXPORTS	ARRAY_SIZE(mcf_ports)
+
+/****************************************************************************/
+#if defined(CONFIG_SERIAL_MCF_CONSOLE)
+/****************************************************************************/
+
+int __init early_mcf_setup(struct mcf_platform_uart *platp)
+{
+	struct uart_port *port;
+	int i;
+
+	for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
+		port = &mcf_ports[i].port;
+
+		port->line = i;
+		port->type = PORT_MCF;
+		port->mapbase = platp[i].mapbase;
+		port->membase = (platp[i].membase) ? platp[i].membase :
+			(unsigned char __iomem *) port->mapbase;
+		port->iotype = SERIAL_IO_MEM;
+		port->irq = platp[i].irq;
+		port->uartclk = MCF_BUSCLK;
+		port->flags = UPF_BOOT_AUTOCONF;
+		port->rs485_config = mcf_config_rs485;
+		port->rs485_supported = mcf_rs485_supported;
+		port->ops = &mcf_uart_ops;
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+
+static void mcf_console_putc(struct console *co, const char c)
+{
+	struct uart_port *port = &(mcf_ports + co->index)->port;
+	int i;
+
+	for (i = 0; (i < 0x10000); i++) {
+		if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
+			break;
+	}
+	writeb(c, port->membase + MCFUART_UTB);
+	for (i = 0; (i < 0x10000); i++) {
+		if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
+			break;
+	}
+}
+
+/****************************************************************************/
+
+static void mcf_console_write(struct console *co, const char *s, unsigned int count)
+{
+	for (; (count); count--, s++) {
+		mcf_console_putc(co, *s);
+		if (*s == '\n')
+			mcf_console_putc(co, '\r');
+	}
+}
+
+/****************************************************************************/
+
+static int __init mcf_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = CONFIG_SERIAL_MCF_BAUDRATE;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if ((co->index < 0) || (co->index >= MCF_MAXPORTS))
+		co->index = 0;
+	port = &mcf_ports[co->index].port;
+	if (port->membase == 0)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+/****************************************************************************/
+
+static struct uart_driver mcf_driver;
+
+static struct console mcf_console = {
+	.name		= "ttyS",
+	.write		= mcf_console_write,
+	.device		= uart_console_device,
+	.setup		= mcf_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &mcf_driver,
+};
+
+static int __init mcf_console_init(void)
+{
+	register_console(&mcf_console);
+	return 0;
+}
+
+console_initcall(mcf_console_init);
+
+#define	MCF_CONSOLE	&mcf_console
+
+/****************************************************************************/
+#else
+/****************************************************************************/
+
+#define	MCF_CONSOLE	NULL
+
+/****************************************************************************/
+#endif /* CONFIG_SERIAL_MCF_CONSOLE */
+/****************************************************************************/
+
+/*
+ *	Define the mcf UART driver structure.
+ */
+static struct uart_driver mcf_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "mcf",
+	.dev_name	= "ttyS",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= MCF_MAXPORTS,
+	.cons		= MCF_CONSOLE,
+};
+
+/****************************************************************************/
+
+static int mcf_probe(struct platform_device *pdev)
+{
+	struct mcf_platform_uart *platp = dev_get_platdata(&pdev->dev);
+	struct uart_port *port;
+	int i;
+
+	for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
+		port = &mcf_ports[i].port;
+
+		port->line = i;
+		port->type = PORT_MCF;
+		port->mapbase = platp[i].mapbase;
+		port->membase = (platp[i].membase) ? platp[i].membase :
+			(unsigned char __iomem *) platp[i].mapbase;
+		port->dev = &pdev->dev;
+		port->iotype = SERIAL_IO_MEM;
+		port->irq = platp[i].irq;
+		port->uartclk = MCF_BUSCLK;
+		port->ops = &mcf_uart_ops;
+		port->flags = UPF_BOOT_AUTOCONF;
+		port->rs485_config = mcf_config_rs485;
+		port->rs485_supported = mcf_rs485_supported;
+		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MCF_CONSOLE);
+
+		uart_add_one_port(&mcf_driver, port);
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+
+static int mcf_remove(struct platform_device *pdev)
+{
+	struct uart_port *port;
+	int i;
+
+	for (i = 0; (i < MCF_MAXPORTS); i++) {
+		port = &mcf_ports[i].port;
+		if (port)
+			uart_remove_one_port(&mcf_driver, port);
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+
+static struct platform_driver mcf_platform_driver = {
+	.probe		= mcf_probe,
+	.remove		= mcf_remove,
+	.driver		= {
+		.name	= "mcfuart",
+	},
+};
+
+/****************************************************************************/
+
+static int __init mcf_init(void)
+{
+	int rc;
+
+	printk("ColdFire internal UART serial driver\n");
+
+	rc = uart_register_driver(&mcf_driver);
+	if (rc)
+		return rc;
+	rc = platform_driver_register(&mcf_platform_driver);
+	if (rc) {
+		uart_unregister_driver(&mcf_driver);
+		return rc;
+	}
+	return 0;
+}
+
+/****************************************************************************/
+
+static void __exit mcf_exit(void)
+{
+	platform_driver_unregister(&mcf_platform_driver);
+	uart_unregister_driver(&mcf_driver);
+}
+
+/****************************************************************************/
+
+module_init(mcf_init);
+module_exit(mcf_exit);
+
+MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
+MODULE_DESCRIPTION("Freescale ColdFire UART driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mcfuart");
+
+/****************************************************************************/
diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c
new file mode 100644
index 000000000..d2502aaa3
--- /dev/null
+++ b/drivers/tty/serial/men_z135_uart.c
@@ -0,0 +1,929 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MEN 16z135 High Speed UART
+ *
+ * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
+ * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ":" fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/serial_core.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/tty_flip.h>
+#include <linux/bitops.h>
+#include <linux/mcb.h>
+
+#define MEN_Z135_MAX_PORTS		12
+#define MEN_Z135_BASECLK		29491200
+#define MEN_Z135_FIFO_SIZE		1024
+#define MEN_Z135_FIFO_WATERMARK		1020
+
+#define MEN_Z135_STAT_REG		0x0
+#define MEN_Z135_RX_RAM			0x4
+#define MEN_Z135_TX_RAM			0x400
+#define MEN_Z135_RX_CTRL		0x800
+#define MEN_Z135_TX_CTRL		0x804
+#define MEN_Z135_CONF_REG		0x808
+#define MEN_Z135_UART_FREQ		0x80c
+#define MEN_Z135_BAUD_REG		0x810
+#define MEN_Z135_TIMEOUT		0x814
+
+#define IRQ_ID(x) ((x) & 0x1f)
+
+#define MEN_Z135_IER_RXCIEN BIT(0)		/* RX Space IRQ */
+#define MEN_Z135_IER_TXCIEN BIT(1)		/* TX Space IRQ */
+#define MEN_Z135_IER_RLSIEN BIT(2)		/* Receiver Line Status IRQ */
+#define MEN_Z135_IER_MSIEN  BIT(3)		/* Modem Status IRQ */
+#define MEN_Z135_ALL_IRQS (MEN_Z135_IER_RXCIEN		\
+				| MEN_Z135_IER_RLSIEN	\
+				| MEN_Z135_IER_MSIEN	\
+				| MEN_Z135_IER_TXCIEN)
+
+#define MEN_Z135_MCR_DTR	BIT(24)
+#define MEN_Z135_MCR_RTS	BIT(25)
+#define MEN_Z135_MCR_OUT1	BIT(26)
+#define MEN_Z135_MCR_OUT2	BIT(27)
+#define MEN_Z135_MCR_LOOP	BIT(28)
+#define MEN_Z135_MCR_RCFC	BIT(29)
+
+#define MEN_Z135_MSR_DCTS	BIT(0)
+#define MEN_Z135_MSR_DDSR	BIT(1)
+#define MEN_Z135_MSR_DRI	BIT(2)
+#define MEN_Z135_MSR_DDCD	BIT(3)
+#define MEN_Z135_MSR_CTS	BIT(4)
+#define MEN_Z135_MSR_DSR	BIT(5)
+#define MEN_Z135_MSR_RI		BIT(6)
+#define MEN_Z135_MSR_DCD	BIT(7)
+
+#define MEN_Z135_LCR_SHIFT 8	/* LCR shift mask */
+
+#define MEN_Z135_WL5 0		/* CS5 */
+#define MEN_Z135_WL6 1		/* CS6 */
+#define MEN_Z135_WL7 2		/* CS7 */
+#define MEN_Z135_WL8 3		/* CS8 */
+
+#define MEN_Z135_STB_SHIFT 2	/* Stopbits */
+#define MEN_Z135_NSTB1 0
+#define MEN_Z135_NSTB2 1
+
+#define MEN_Z135_PEN_SHIFT 3	/* Parity enable */
+#define MEN_Z135_PAR_DIS 0
+#define MEN_Z135_PAR_ENA 1
+
+#define MEN_Z135_PTY_SHIFT 4	/* Parity type */
+#define MEN_Z135_PTY_ODD 0
+#define MEN_Z135_PTY_EVN 1
+
+#define MEN_Z135_LSR_DR BIT(0)
+#define MEN_Z135_LSR_OE BIT(1)
+#define MEN_Z135_LSR_PE BIT(2)
+#define MEN_Z135_LSR_FE BIT(3)
+#define MEN_Z135_LSR_BI BIT(4)
+#define MEN_Z135_LSR_THEP BIT(5)
+#define MEN_Z135_LSR_TEXP BIT(6)
+#define MEN_Z135_LSR_RXFIFOERR BIT(7)
+
+#define MEN_Z135_IRQ_ID_RLS BIT(0)
+#define MEN_Z135_IRQ_ID_RDA BIT(1)
+#define MEN_Z135_IRQ_ID_CTI BIT(2)
+#define MEN_Z135_IRQ_ID_TSA BIT(3)
+#define MEN_Z135_IRQ_ID_MST BIT(4)
+
+#define LCR(x) (((x) >> MEN_Z135_LCR_SHIFT) & 0xff)
+
+#define BYTES_TO_ALIGN(x) ((x) & 0x3)
+
+static int line;
+
+static int txlvl = 5;
+module_param(txlvl, int, S_IRUGO);
+MODULE_PARM_DESC(txlvl, "TX IRQ trigger level 0-7, default 5 (128 byte)");
+
+static int rxlvl = 6;
+module_param(rxlvl, int, S_IRUGO);
+MODULE_PARM_DESC(rxlvl, "RX IRQ trigger level 0-7, default 6 (256 byte)");
+
+static int align;
+module_param(align, int, S_IRUGO);
+MODULE_PARM_DESC(align, "Keep hardware FIFO write pointer aligned, default 0");
+
+static uint rx_timeout;
+module_param(rx_timeout, uint, S_IRUGO);
+MODULE_PARM_DESC(rx_timeout, "RX timeout. "
+		"Timeout in seconds = (timeout_reg * baud_reg * 4) / freq_reg");
+
+struct men_z135_port {
+	struct uart_port port;
+	struct mcb_device *mdev;
+	struct resource *mem;
+	unsigned char *rxbuf;
+	u32 stat_reg;
+	spinlock_t lock;
+	bool automode;
+};
+#define to_men_z135(port) container_of((port), struct men_z135_port, port)
+
+/**
+ * men_z135_reg_set() - Set value in register
+ * @uart: The UART port
+ * @addr: Register address
+ * @val: value to set
+ */
+static inline void men_z135_reg_set(struct men_z135_port *uart,
+				u32 addr, u32 val)
+{
+	struct uart_port *port = &uart->port;
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&uart->lock, flags);
+
+	reg = ioread32(port->membase + addr);
+	reg |= val;
+	iowrite32(reg, port->membase + addr);
+
+	spin_unlock_irqrestore(&uart->lock, flags);
+}
+
+/**
+ * men_z135_reg_clr() - Unset value in register
+ * @uart: The UART port
+ * @addr: Register address
+ * @val: value to clear
+ */
+static void men_z135_reg_clr(struct men_z135_port *uart,
+				u32 addr, u32 val)
+{
+	struct uart_port *port = &uart->port;
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&uart->lock, flags);
+
+	reg = ioread32(port->membase + addr);
+	reg &= ~val;
+	iowrite32(reg, port->membase + addr);
+
+	spin_unlock_irqrestore(&uart->lock, flags);
+}
+
+/**
+ * men_z135_handle_modem_status() - Handle change of modem status
+ * @uart: The UART port
+ *
+ * Handle change of modem status register. This is done by reading the "delta"
+ * versions of DCD (Data Carrier Detect) and CTS (Clear To Send).
+ */
+static void men_z135_handle_modem_status(struct men_z135_port *uart)
+{
+	u8 msr;
+
+	msr = (uart->stat_reg >> 8) & 0xff;
+
+	if (msr & MEN_Z135_MSR_DDCD)
+		uart_handle_dcd_change(&uart->port,
+				msr & MEN_Z135_MSR_DCD);
+	if (msr & MEN_Z135_MSR_DCTS)
+		uart_handle_cts_change(&uart->port,
+				msr & MEN_Z135_MSR_CTS);
+}
+
+static void men_z135_handle_lsr(struct men_z135_port *uart)
+{
+	struct uart_port *port = &uart->port;
+	u8 lsr;
+
+	lsr = (uart->stat_reg >> 16) & 0xff;
+
+	if (lsr & MEN_Z135_LSR_OE)
+		port->icount.overrun++;
+	if (lsr & MEN_Z135_LSR_PE)
+		port->icount.parity++;
+	if (lsr & MEN_Z135_LSR_FE)
+		port->icount.frame++;
+	if (lsr & MEN_Z135_LSR_BI) {
+		port->icount.brk++;
+		uart_handle_break(port);
+	}
+}
+
+/**
+ * get_rx_fifo_content() - Get the number of bytes in RX FIFO
+ * @uart: The UART port
+ *
+ * Read RXC register from hardware and return current FIFO fill size.
+ */
+static u16 get_rx_fifo_content(struct men_z135_port *uart)
+{
+	struct uart_port *port = &uart->port;
+	u32 stat_reg;
+	u16 rxc;
+	u8 rxc_lo;
+	u8 rxc_hi;
+
+	stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
+	rxc_lo = stat_reg >> 24;
+	rxc_hi = (stat_reg & 0xC0) >> 6;
+
+	rxc = rxc_lo | (rxc_hi << 8);
+
+	return rxc;
+}
+
+/**
+ * men_z135_handle_rx() - RX tasklet routine
+ * @uart: Pointer to struct men_z135_port
+ *
+ * Copy from RX FIFO and acknowledge number of bytes copied.
+ */
+static void men_z135_handle_rx(struct men_z135_port *uart)
+{
+	struct uart_port *port = &uart->port;
+	struct tty_port *tport = &port->state->port;
+	int copied;
+	u16 size;
+	int room;
+
+	size = get_rx_fifo_content(uart);
+
+	if (size == 0)
+		return;
+
+	/* Avoid accidently accessing TX FIFO instead of RX FIFO. Last
+	 * longword in RX FIFO cannot be read.(0x004-0x3FF)
+	 */
+	if (size > MEN_Z135_FIFO_WATERMARK)
+		size = MEN_Z135_FIFO_WATERMARK;
+
+	room = tty_buffer_request_room(tport, size);
+	if (room != size)
+		dev_warn(&uart->mdev->dev,
+			"Not enough room in flip buffer, truncating to %d\n",
+			room);
+
+	if (room == 0)
+		return;
+
+	memcpy_fromio(uart->rxbuf, port->membase + MEN_Z135_RX_RAM, room);
+	/* Be sure to first copy all data and then acknowledge it */
+	mb();
+	iowrite32(room, port->membase +  MEN_Z135_RX_CTRL);
+
+	copied = tty_insert_flip_string(tport, uart->rxbuf, room);
+	if (copied != room)
+		dev_warn(&uart->mdev->dev,
+			"Only copied %d instead of %d bytes\n",
+			copied, room);
+
+	port->icount.rx += copied;
+
+	tty_flip_buffer_push(tport);
+
+}
+
+/**
+ * men_z135_handle_tx() - TX tasklet routine
+ * @uart: Pointer to struct men_z135_port
+ *
+ */
+static void men_z135_handle_tx(struct men_z135_port *uart)
+{
+	struct uart_port *port = &uart->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	u32 txc;
+	u32 wptr;
+	int qlen;
+	int n;
+	int txfree;
+	int head;
+	int tail;
+	int s;
+
+	if (uart_circ_empty(xmit))
+		goto out;
+
+	if (uart_tx_stopped(port))
+		goto out;
+
+	if (port->x_char)
+		goto out;
+
+	/* calculate bytes to copy */
+	qlen = uart_circ_chars_pending(xmit);
+	if (qlen <= 0)
+		goto out;
+
+	wptr = ioread32(port->membase + MEN_Z135_TX_CTRL);
+	txc = (wptr >> 16) & 0x3ff;
+	wptr &= 0x3ff;
+
+	if (txc > MEN_Z135_FIFO_WATERMARK)
+		txc = MEN_Z135_FIFO_WATERMARK;
+
+	txfree = MEN_Z135_FIFO_WATERMARK - txc;
+	if (txfree <= 0) {
+		dev_err(&uart->mdev->dev,
+			"Not enough room in TX FIFO have %d, need %d\n",
+			txfree, qlen);
+		goto irq_en;
+	}
+
+	/* if we're not aligned, it's better to copy only 1 or 2 bytes and
+	 * then the rest.
+	 */
+	if (align && qlen >= 3 && BYTES_TO_ALIGN(wptr))
+		n = 4 - BYTES_TO_ALIGN(wptr);
+	else if (qlen > txfree)
+		n = txfree;
+	else
+		n = qlen;
+
+	if (n <= 0)
+		goto irq_en;
+
+	head = xmit->head & (UART_XMIT_SIZE - 1);
+	tail = xmit->tail & (UART_XMIT_SIZE - 1);
+
+	s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
+	n = min(n, s);
+
+	memcpy_toio(port->membase + MEN_Z135_TX_RAM, &xmit->buf[xmit->tail], n);
+	iowrite32(n & 0x3ff, port->membase + MEN_Z135_TX_CTRL);
+	uart_xmit_advance(port, n);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+irq_en:
+	if (!uart_circ_empty(xmit))
+		men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
+	else
+		men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
+
+out:
+	return;
+
+}
+
+/**
+ * men_z135_intr() - Handle legacy IRQs
+ * @irq: The IRQ number
+ * @data: Pointer to UART port
+ *
+ * Check IIR register to find the cause of the interrupt and handle it.
+ * It is possible that multiple interrupts reason bits are set and reading
+ * the IIR is a destructive read, so we always need to check for all possible
+ * interrupts and handle them.
+ */
+static irqreturn_t men_z135_intr(int irq, void *data)
+{
+	struct men_z135_port *uart = (struct men_z135_port *)data;
+	struct uart_port *port = &uart->port;
+	bool handled = false;
+	int irq_id;
+
+	uart->stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
+	irq_id = IRQ_ID(uart->stat_reg);
+
+	if (!irq_id)
+		goto out;
+
+	spin_lock(&port->lock);
+	/* It's save to write to IIR[7:6] RXC[9:8] */
+	iowrite8(irq_id, port->membase + MEN_Z135_STAT_REG);
+
+	if (irq_id & MEN_Z135_IRQ_ID_RLS) {
+		men_z135_handle_lsr(uart);
+		handled = true;
+	}
+
+	if (irq_id & (MEN_Z135_IRQ_ID_RDA | MEN_Z135_IRQ_ID_CTI)) {
+		if (irq_id & MEN_Z135_IRQ_ID_CTI)
+			dev_dbg(&uart->mdev->dev, "Character Timeout Indication\n");
+		men_z135_handle_rx(uart);
+		handled = true;
+	}
+
+	if (irq_id & MEN_Z135_IRQ_ID_TSA) {
+		men_z135_handle_tx(uart);
+		handled = true;
+	}
+
+	if (irq_id & MEN_Z135_IRQ_ID_MST) {
+		men_z135_handle_modem_status(uart);
+		handled = true;
+	}
+
+	spin_unlock(&port->lock);
+out:
+	return IRQ_RETVAL(handled);
+}
+
+/**
+ * men_z135_request_irq() - Request IRQ for 16z135 core
+ * @uart: z135 private uart port structure
+ *
+ * Request an IRQ for 16z135 to use. First try using MSI, if it fails
+ * fall back to using legacy interrupts.
+ */
+static int men_z135_request_irq(struct men_z135_port *uart)
+{
+	struct device *dev = &uart->mdev->dev;
+	struct uart_port *port = &uart->port;
+	int err = 0;
+
+	err = request_irq(port->irq, men_z135_intr, IRQF_SHARED,
+			"men_z135_intr", uart);
+	if (err)
+		dev_err(dev, "Error %d getting interrupt\n", err);
+
+	return err;
+}
+
+/**
+ * men_z135_tx_empty() - Handle tx_empty call
+ * @port: The UART port
+ *
+ * This function tests whether the TX FIFO and shifter for the port
+ * described by @port is empty.
+ */
+static unsigned int men_z135_tx_empty(struct uart_port *port)
+{
+	u32 wptr;
+	u16 txc;
+
+	wptr = ioread32(port->membase + MEN_Z135_TX_CTRL);
+	txc = (wptr >> 16) & 0x3ff;
+
+	if (txc == 0)
+		return TIOCSER_TEMT;
+	else
+		return 0;
+}
+
+/**
+ * men_z135_set_mctrl() - Set modem control lines
+ * @port: The UART port
+ * @mctrl: The modem control lines
+ *
+ * This function sets the modem control lines for a port described by @port
+ * to the state described by @mctrl
+ */
+static void men_z135_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 old;
+	u32 conf_reg;
+
+	conf_reg = old = ioread32(port->membase + MEN_Z135_CONF_REG);
+	if (mctrl & TIOCM_RTS)
+		conf_reg |= MEN_Z135_MCR_RTS;
+	else
+		conf_reg &= ~MEN_Z135_MCR_RTS;
+
+	if (mctrl & TIOCM_DTR)
+		conf_reg |= MEN_Z135_MCR_DTR;
+	else
+		conf_reg &= ~MEN_Z135_MCR_DTR;
+
+	if (mctrl & TIOCM_OUT1)
+		conf_reg |= MEN_Z135_MCR_OUT1;
+	else
+		conf_reg &= ~MEN_Z135_MCR_OUT1;
+
+	if (mctrl & TIOCM_OUT2)
+		conf_reg |= MEN_Z135_MCR_OUT2;
+	else
+		conf_reg &= ~MEN_Z135_MCR_OUT2;
+
+	if (mctrl & TIOCM_LOOP)
+		conf_reg |= MEN_Z135_MCR_LOOP;
+	else
+		conf_reg &= ~MEN_Z135_MCR_LOOP;
+
+	if (conf_reg != old)
+		iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
+}
+
+/**
+ * men_z135_get_mctrl() - Get modem control lines
+ * @port: The UART port
+ *
+ * Retruns the current state of modem control inputs.
+ */
+static unsigned int men_z135_get_mctrl(struct uart_port *port)
+{
+	unsigned int mctrl = 0;
+	u8 msr;
+
+	msr = ioread8(port->membase + MEN_Z135_STAT_REG + 1);
+
+	if (msr & MEN_Z135_MSR_CTS)
+		mctrl |= TIOCM_CTS;
+	if (msr & MEN_Z135_MSR_DSR)
+		mctrl |= TIOCM_DSR;
+	if (msr & MEN_Z135_MSR_RI)
+		mctrl |= TIOCM_RI;
+	if (msr & MEN_Z135_MSR_DCD)
+		mctrl |= TIOCM_CAR;
+
+	return mctrl;
+}
+
+/**
+ * men_z135_stop_tx() - Stop transmitting characters
+ * @port: The UART port
+ *
+ * Stop transmitting characters. This might be due to CTS line becomming
+ * inactive or the tty layer indicating we want to stop transmission due to
+ * an XOFF character.
+ */
+static void men_z135_stop_tx(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
+}
+
+/*
+ * men_z135_disable_ms() - Disable Modem Status
+ * port: The UART port
+ *
+ * Enable Modem Status IRQ.
+ */
+static void men_z135_disable_ms(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_MSIEN);
+}
+
+/**
+ * men_z135_start_tx() - Start transmitting characters
+ * @port: The UART port
+ *
+ * Start transmitting character. This actually doesn't transmit anything, but
+ * fires off the TX tasklet.
+ */
+static void men_z135_start_tx(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	if (uart->automode)
+		men_z135_disable_ms(port);
+
+	men_z135_handle_tx(uart);
+}
+
+/**
+ * men_z135_stop_rx() - Stop receiving characters
+ * @port: The UART port
+ *
+ * Stop receiving characters; the port is in the process of being closed.
+ */
+static void men_z135_stop_rx(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_RXCIEN);
+}
+
+/**
+ * men_z135_enable_ms() - Enable Modem Status
+ * @port: the port
+ *
+ * Enable Modem Status IRQ.
+ */
+static void men_z135_enable_ms(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_MSIEN);
+}
+
+static int men_z135_startup(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+	int err;
+	u32 conf_reg = 0;
+
+	err = men_z135_request_irq(uart);
+	if (err)
+		return -ENODEV;
+
+	conf_reg = ioread32(port->membase + MEN_Z135_CONF_REG);
+
+	/* Activate all but TX space available IRQ */
+	conf_reg |= MEN_Z135_ALL_IRQS & ~MEN_Z135_IER_TXCIEN;
+	conf_reg &= ~(0xff << 16);
+	conf_reg |= (txlvl << 16);
+	conf_reg |= (rxlvl << 20);
+
+	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
+
+	if (rx_timeout)
+		iowrite32(rx_timeout, port->membase + MEN_Z135_TIMEOUT);
+
+	return 0;
+}
+
+static void men_z135_shutdown(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+	u32 conf_reg = 0;
+
+	conf_reg |= MEN_Z135_ALL_IRQS;
+
+	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, conf_reg);
+
+	free_irq(uart->port.irq, uart);
+}
+
+static void men_z135_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+	unsigned int baud;
+	u32 conf_reg;
+	u32 bd_reg;
+	u32 uart_freq;
+	u8 lcr;
+
+	conf_reg = ioread32(port->membase + MEN_Z135_CONF_REG);
+	lcr = LCR(conf_reg);
+
+	/* byte size */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr |= MEN_Z135_WL5;
+		break;
+	case CS6:
+		lcr |= MEN_Z135_WL6;
+		break;
+	case CS7:
+		lcr |= MEN_Z135_WL7;
+		break;
+	case CS8:
+		lcr |= MEN_Z135_WL8;
+		break;
+	}
+
+	/* stop bits */
+	if (termios->c_cflag & CSTOPB)
+		lcr |= MEN_Z135_NSTB2 << MEN_Z135_STB_SHIFT;
+
+	/* parity */
+	if (termios->c_cflag & PARENB) {
+		lcr |= MEN_Z135_PAR_ENA << MEN_Z135_PEN_SHIFT;
+
+		if (termios->c_cflag & PARODD)
+			lcr |= MEN_Z135_PTY_ODD << MEN_Z135_PTY_SHIFT;
+		else
+			lcr |= MEN_Z135_PTY_EVN << MEN_Z135_PTY_SHIFT;
+	} else
+		lcr |= MEN_Z135_PAR_DIS << MEN_Z135_PEN_SHIFT;
+
+	conf_reg |= MEN_Z135_IER_MSIEN;
+	if (termios->c_cflag & CRTSCTS) {
+		conf_reg |= MEN_Z135_MCR_RCFC;
+		uart->automode = true;
+		termios->c_cflag &= ~CLOCAL;
+	} else {
+		conf_reg &= ~MEN_Z135_MCR_RCFC;
+		uart->automode = false;
+	}
+
+	termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
+
+	conf_reg |= lcr << MEN_Z135_LCR_SHIFT;
+	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
+
+	uart_freq = ioread32(port->membase + MEN_Z135_UART_FREQ);
+	if (uart_freq == 0)
+		uart_freq = MEN_Z135_BASECLK;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, uart_freq / 16);
+
+	spin_lock_irq(&port->lock);
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	bd_reg = uart_freq / (4 * baud);
+	iowrite32(bd_reg, port->membase + MEN_Z135_BAUD_REG);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	spin_unlock_irq(&port->lock);
+}
+
+static const char *men_z135_type(struct uart_port *port)
+{
+	return KBUILD_MODNAME;
+}
+
+static void men_z135_release_port(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	iounmap(port->membase);
+	port->membase = NULL;
+
+	mcb_release_mem(uart->mem);
+}
+
+static int men_z135_request_port(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+	struct mcb_device *mdev = uart->mdev;
+	struct resource *mem;
+
+	mem = mcb_request_mem(uart->mdev, dev_name(&mdev->dev));
+	if (IS_ERR(mem))
+		return PTR_ERR(mem);
+
+	port->mapbase = mem->start;
+	uart->mem = mem;
+
+	port->membase = ioremap(mem->start, resource_size(mem));
+	if (port->membase == NULL) {
+		mcb_release_mem(mem);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void men_z135_config_port(struct uart_port *port, int type)
+{
+	port->type = PORT_MEN_Z135;
+	men_z135_request_port(port);
+}
+
+static int men_z135_verify_port(struct uart_port *port,
+				struct serial_struct *serinfo)
+{
+	return -EINVAL;
+}
+
+static const struct uart_ops men_z135_ops = {
+	.tx_empty = men_z135_tx_empty,
+	.set_mctrl = men_z135_set_mctrl,
+	.get_mctrl = men_z135_get_mctrl,
+	.stop_tx = men_z135_stop_tx,
+	.start_tx = men_z135_start_tx,
+	.stop_rx = men_z135_stop_rx,
+	.enable_ms = men_z135_enable_ms,
+	.startup = men_z135_startup,
+	.shutdown = men_z135_shutdown,
+	.set_termios = men_z135_set_termios,
+	.type = men_z135_type,
+	.release_port = men_z135_release_port,
+	.request_port = men_z135_request_port,
+	.config_port = men_z135_config_port,
+	.verify_port = men_z135_verify_port,
+};
+
+static struct uart_driver men_z135_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = KBUILD_MODNAME,
+	.dev_name = "ttyHSU",
+	.major = 0,
+	.minor = 0,
+	.nr = MEN_Z135_MAX_PORTS,
+};
+
+/**
+ * men_z135_probe() - Probe a z135 instance
+ * @mdev: The MCB device
+ * @id: The MCB device ID
+ *
+ * men_z135_probe does the basic setup of hardware resources and registers the
+ * new uart port to the tty layer.
+ */
+static int men_z135_probe(struct mcb_device *mdev,
+			const struct mcb_device_id *id)
+{
+	struct men_z135_port *uart;
+	struct resource *mem;
+	struct device *dev;
+	int err;
+
+	dev = &mdev->dev;
+
+	uart = devm_kzalloc(dev, sizeof(struct men_z135_port), GFP_KERNEL);
+	if (!uart)
+		return -ENOMEM;
+
+	uart->rxbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
+	if (!uart->rxbuf)
+		return -ENOMEM;
+
+	mem = &mdev->mem;
+
+	mcb_set_drvdata(mdev, uart);
+
+	uart->port.uartclk = MEN_Z135_BASECLK * 16;
+	uart->port.fifosize = MEN_Z135_FIFO_SIZE;
+	uart->port.iotype = UPIO_MEM;
+	uart->port.ops = &men_z135_ops;
+	uart->port.irq = mcb_get_irq(mdev);
+	uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+	uart->port.line = line++;
+	uart->port.dev = dev;
+	uart->port.type = PORT_MEN_Z135;
+	uart->port.mapbase = mem->start;
+	uart->port.membase = NULL;
+	uart->mdev = mdev;
+
+	spin_lock_init(&uart->lock);
+
+	err = uart_add_one_port(&men_z135_driver, &uart->port);
+	if (err)
+		goto err;
+
+	return 0;
+
+err:
+	free_page((unsigned long) uart->rxbuf);
+	dev_err(dev, "Failed to add UART: %d\n", err);
+
+	return err;
+}
+
+/**
+ * men_z135_remove() - Remove a z135 instance from the system
+ *
+ * @mdev: The MCB device
+ */
+static void men_z135_remove(struct mcb_device *mdev)
+{
+	struct men_z135_port *uart = mcb_get_drvdata(mdev);
+
+	line--;
+	uart_remove_one_port(&men_z135_driver, &uart->port);
+	free_page((unsigned long) uart->rxbuf);
+}
+
+static const struct mcb_device_id men_z135_ids[] = {
+	{ .device = 0x87 },
+	{ }
+};
+MODULE_DEVICE_TABLE(mcb, men_z135_ids);
+
+static struct mcb_driver mcb_driver = {
+	.driver = {
+		.name = "z135-uart",
+		.owner = THIS_MODULE,
+	},
+	.probe = men_z135_probe,
+	.remove = men_z135_remove,
+	.id_table = men_z135_ids,
+};
+
+/**
+ * men_z135_init() - Driver Registration Routine
+ *
+ * men_z135_init is the first routine called when the driver is loaded. All it
+ * does is register with the legacy MEN Chameleon subsystem.
+ */
+static int __init men_z135_init(void)
+{
+	int err;
+
+	err = uart_register_driver(&men_z135_driver);
+	if (err) {
+		pr_err("Failed to register UART: %d\n", err);
+		return err;
+	}
+
+	err = mcb_register_driver(&mcb_driver);
+	if  (err) {
+		pr_err("Failed to register MCB driver: %d\n", err);
+		uart_unregister_driver(&men_z135_driver);
+		return err;
+	}
+
+	return 0;
+}
+module_init(men_z135_init);
+
+/**
+ * men_z135_exit() - Driver Exit Routine
+ *
+ * men_z135_exit is called just before the driver is removed from memory.
+ */
+static void __exit men_z135_exit(void)
+{
+	mcb_unregister_driver(&mcb_driver);
+	uart_unregister_driver(&men_z135_driver);
+}
+module_exit(men_z135_exit);
+
+MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MEN 16z135 High Speed UART");
+MODULE_ALIAS("mcb:16z135");
+MODULE_IMPORT_NS(MCB);
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
new file mode 100644
index 000000000..9388b9dde
--- /dev/null
+++ b/drivers/tty/serial/meson_uart.c
@@ -0,0 +1,866 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Based on meson_uart.c, by AMLOGIC, INC.
+ *
+ * Copyright (C) 2014 Carlo Caione <carlo@caione.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/* Register offsets */
+#define AML_UART_WFIFO			0x00
+#define AML_UART_RFIFO			0x04
+#define AML_UART_CONTROL		0x08
+#define AML_UART_STATUS			0x0c
+#define AML_UART_MISC			0x10
+#define AML_UART_REG5			0x14
+
+/* AML_UART_CONTROL bits */
+#define AML_UART_TX_EN			BIT(12)
+#define AML_UART_RX_EN			BIT(13)
+#define AML_UART_TWO_WIRE_EN		BIT(15)
+#define AML_UART_STOP_BIT_LEN_MASK	(0x03 << 16)
+#define AML_UART_STOP_BIT_1SB		(0x00 << 16)
+#define AML_UART_STOP_BIT_2SB		(0x01 << 16)
+#define AML_UART_PARITY_TYPE		BIT(18)
+#define AML_UART_PARITY_EN		BIT(19)
+#define AML_UART_TX_RST			BIT(22)
+#define AML_UART_RX_RST			BIT(23)
+#define AML_UART_CLEAR_ERR		BIT(24)
+#define AML_UART_RX_INT_EN		BIT(27)
+#define AML_UART_TX_INT_EN		BIT(28)
+#define AML_UART_DATA_LEN_MASK		(0x03 << 20)
+#define AML_UART_DATA_LEN_8BIT		(0x00 << 20)
+#define AML_UART_DATA_LEN_7BIT		(0x01 << 20)
+#define AML_UART_DATA_LEN_6BIT		(0x02 << 20)
+#define AML_UART_DATA_LEN_5BIT		(0x03 << 20)
+
+/* AML_UART_STATUS bits */
+#define AML_UART_PARITY_ERR		BIT(16)
+#define AML_UART_FRAME_ERR		BIT(17)
+#define AML_UART_TX_FIFO_WERR		BIT(18)
+#define AML_UART_RX_EMPTY		BIT(20)
+#define AML_UART_TX_FULL		BIT(21)
+#define AML_UART_TX_EMPTY		BIT(22)
+#define AML_UART_XMIT_BUSY		BIT(25)
+#define AML_UART_ERR			(AML_UART_PARITY_ERR | \
+					 AML_UART_FRAME_ERR  | \
+					 AML_UART_TX_FIFO_WERR)
+
+/* AML_UART_MISC bits */
+#define AML_UART_XMIT_IRQ(c)		(((c) & 0xff) << 8)
+#define AML_UART_RECV_IRQ(c)		((c) & 0xff)
+
+/* AML_UART_REG5 bits */
+#define AML_UART_BAUD_MASK		0x7fffff
+#define AML_UART_BAUD_USE		BIT(23)
+#define AML_UART_BAUD_XTAL		BIT(24)
+#define AML_UART_BAUD_XTAL_DIV2		BIT(27)
+
+#define AML_UART_PORT_NUM		12
+#define AML_UART_PORT_OFFSET		6
+
+#define AML_UART_POLL_USEC		5
+#define AML_UART_TIMEOUT_USEC		10000
+
+static struct uart_driver meson_uart_driver_ttyAML;
+static struct uart_driver meson_uart_driver_ttyS;
+
+static struct uart_port *meson_ports[AML_UART_PORT_NUM];
+
+struct meson_uart_data {
+	struct uart_driver *uart_driver;
+	bool has_xtal_div2;
+};
+
+static void meson_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int meson_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS;
+}
+
+static unsigned int meson_uart_tx_empty(struct uart_port *port)
+{
+	u32 val;
+
+	val = readl(port->membase + AML_UART_STATUS);
+	val &= (AML_UART_TX_EMPTY | AML_UART_XMIT_BUSY);
+	return (val == AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0;
+}
+
+static void meson_uart_stop_tx(struct uart_port *port)
+{
+	u32 val;
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val &= ~AML_UART_TX_INT_EN;
+	writel(val, port->membase + AML_UART_CONTROL);
+}
+
+static void meson_uart_stop_rx(struct uart_port *port)
+{
+	u32 val;
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val &= ~AML_UART_RX_EN;
+	writel(val, port->membase + AML_UART_CONTROL);
+}
+
+static void meson_uart_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+	u32 val;
+
+	free_irq(port->irq, port);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val &= ~AML_UART_RX_EN;
+	val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void meson_uart_start_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int ch;
+	u32 val;
+
+	if (uart_tx_stopped(port)) {
+		meson_uart_stop_tx(port);
+		return;
+	}
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
+		if (port->x_char) {
+			writel(port->x_char, port->membase + AML_UART_WFIFO);
+			port->icount.tx++;
+			port->x_char = 0;
+			continue;
+		}
+
+		if (uart_circ_empty(xmit))
+			break;
+
+		ch = xmit->buf[xmit->tail];
+		writel(ch, port->membase + AML_UART_WFIFO);
+		uart_xmit_advance(port, 1);
+	}
+
+	if (!uart_circ_empty(xmit)) {
+		val = readl(port->membase + AML_UART_CONTROL);
+		val |= AML_UART_TX_INT_EN;
+		writel(val, port->membase + AML_UART_CONTROL);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static void meson_receive_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	char flag;
+	u32 ostatus, status, ch, mode;
+
+	do {
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+		ostatus = status = readl(port->membase + AML_UART_STATUS);
+
+		if (status & AML_UART_ERR) {
+			if (status & AML_UART_TX_FIFO_WERR)
+				port->icount.overrun++;
+			else if (status & AML_UART_FRAME_ERR)
+				port->icount.frame++;
+			else if (status & AML_UART_PARITY_ERR)
+				port->icount.frame++;
+
+			mode = readl(port->membase + AML_UART_CONTROL);
+			mode |= AML_UART_CLEAR_ERR;
+			writel(mode, port->membase + AML_UART_CONTROL);
+
+			/* It doesn't clear to 0 automatically */
+			mode &= ~AML_UART_CLEAR_ERR;
+			writel(mode, port->membase + AML_UART_CONTROL);
+
+			status &= port->read_status_mask;
+			if (status & AML_UART_FRAME_ERR)
+				flag = TTY_FRAME;
+			else if (status & AML_UART_PARITY_ERR)
+				flag = TTY_PARITY;
+		}
+
+		ch = readl(port->membase + AML_UART_RFIFO);
+		ch &= 0xff;
+
+		if ((ostatus & AML_UART_FRAME_ERR) && (ch == 0)) {
+			port->icount.brk++;
+			flag = TTY_BREAK;
+			if (uart_handle_break(port))
+				continue;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		if ((status & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tport, ch, flag);
+
+		if (status & AML_UART_TX_FIFO_WERR)
+			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+
+	} while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY));
+
+	tty_flip_buffer_push(tport);
+}
+
+static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+
+	spin_lock(&port->lock);
+
+	if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY))
+		meson_receive_chars(port);
+
+	if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
+		if (readl(port->membase + AML_UART_CONTROL) & AML_UART_TX_INT_EN)
+			meson_uart_start_tx(port);
+	}
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static const char *meson_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_MESON) ? "meson_uart" : NULL;
+}
+
+/*
+ * This function is called only from probe() using a temporary io mapping
+ * in order to perform a reset before setting up the device. Since the
+ * temporarily mapped region was successfully requested, there can be no
+ * console on this port at this time. Hence it is not necessary for this
+ * function to acquire the port->lock. (Since there is no console on this
+ * port at this time, the port->lock is not initialized yet.)
+ */
+static void meson_uart_reset(struct uart_port *port)
+{
+	u32 val;
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR);
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR);
+	writel(val, port->membase + AML_UART_CONTROL);
+}
+
+static int meson_uart_startup(struct uart_port *port)
+{
+	unsigned long flags;
+	u32 val;
+	int ret = 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val |= AML_UART_CLEAR_ERR;
+	writel(val, port->membase + AML_UART_CONTROL);
+	val &= ~AML_UART_CLEAR_ERR;
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	val |= (AML_UART_RX_EN | AML_UART_TX_EN);
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	val |= (AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2));
+	writel(val, port->membase + AML_UART_MISC);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	ret = request_irq(port->irq, meson_uart_interrupt, 0,
+			  port->name, port);
+
+	return ret;
+}
+
+static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
+{
+	const struct meson_uart_data *private_data = port->private_data;
+	u32 val = 0;
+
+	while (!meson_uart_tx_empty(port))
+		cpu_relax();
+
+	if (port->uartclk == 24000000) {
+		unsigned int xtal_div = 3;
+
+		if (private_data && private_data->has_xtal_div2) {
+			xtal_div = 2;
+			val |= AML_UART_BAUD_XTAL_DIV2;
+		}
+		val |= DIV_ROUND_CLOSEST(port->uartclk / xtal_div, baud) - 1;
+		val |= AML_UART_BAUD_XTAL;
+	} else {
+		val =  DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1;
+	}
+	val |= AML_UART_BAUD_USE;
+	writel(val, port->membase + AML_UART_REG5);
+}
+
+static void meson_uart_set_termios(struct uart_port *port,
+				   struct ktermios *termios,
+				   const struct ktermios *old)
+{
+	unsigned int cflags, iflags, baud;
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	cflags = termios->c_cflag;
+	iflags = termios->c_iflag;
+
+	val = readl(port->membase + AML_UART_CONTROL);
+
+	val &= ~AML_UART_DATA_LEN_MASK;
+	switch (cflags & CSIZE) {
+	case CS8:
+		val |= AML_UART_DATA_LEN_8BIT;
+		break;
+	case CS7:
+		val |= AML_UART_DATA_LEN_7BIT;
+		break;
+	case CS6:
+		val |= AML_UART_DATA_LEN_6BIT;
+		break;
+	case CS5:
+		val |= AML_UART_DATA_LEN_5BIT;
+		break;
+	}
+
+	if (cflags & PARENB)
+		val |= AML_UART_PARITY_EN;
+	else
+		val &= ~AML_UART_PARITY_EN;
+
+	if (cflags & PARODD)
+		val |= AML_UART_PARITY_TYPE;
+	else
+		val &= ~AML_UART_PARITY_TYPE;
+
+	val &= ~AML_UART_STOP_BIT_LEN_MASK;
+	if (cflags & CSTOPB)
+		val |= AML_UART_STOP_BIT_2SB;
+	else
+		val |= AML_UART_STOP_BIT_1SB;
+
+	if (cflags & CRTSCTS) {
+		if (port->flags & UPF_HARD_FLOW)
+			val &= ~AML_UART_TWO_WIRE_EN;
+		else
+			termios->c_cflag &= ~CRTSCTS;
+	} else {
+		val |= AML_UART_TWO_WIRE_EN;
+	}
+
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	baud = uart_get_baud_rate(port, termios, old, 50, 4000000);
+	meson_uart_change_speed(port, baud);
+
+	port->read_status_mask = AML_UART_TX_FIFO_WERR;
+	if (iflags & INPCK)
+		port->read_status_mask |= AML_UART_PARITY_ERR |
+					  AML_UART_FRAME_ERR;
+
+	port->ignore_status_mask = 0;
+	if (iflags & IGNPAR)
+		port->ignore_status_mask |= AML_UART_PARITY_ERR |
+					    AML_UART_FRAME_ERR;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int meson_uart_verify_port(struct uart_port *port,
+				  struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (port->type != PORT_MESON)
+		ret = -EINVAL;
+	if (port->irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	return ret;
+}
+
+static void meson_uart_release_port(struct uart_port *port)
+{
+	devm_iounmap(port->dev, port->membase);
+	port->membase = NULL;
+	devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
+}
+
+static int meson_uart_request_port(struct uart_port *port)
+{
+	if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize,
+				     dev_name(port->dev))) {
+		dev_err(port->dev, "Memory region busy\n");
+		return -EBUSY;
+	}
+
+	port->membase = devm_ioremap(port->dev, port->mapbase,
+					     port->mapsize);
+	if (!port->membase)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void meson_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_MESON;
+		meson_uart_request_port(port);
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int meson_uart_poll_get_char(struct uart_port *port)
+{
+	u32 c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
+		c = NO_POLL_CHAR;
+	else
+		c = readl(port->membase + AML_UART_RFIFO);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return c;
+}
+
+static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+	u32 reg;
+	int ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Wait until FIFO is empty or timeout */
+	ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
+					reg & AML_UART_TX_EMPTY,
+					AML_UART_POLL_USEC,
+					AML_UART_TIMEOUT_USEC);
+	if (ret == -ETIMEDOUT) {
+		dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
+		goto out;
+	}
+
+	/* Write the character */
+	writel(c, port->membase + AML_UART_WFIFO);
+
+	/* Wait until FIFO is empty or timeout */
+	ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
+					reg & AML_UART_TX_EMPTY,
+					AML_UART_POLL_USEC,
+					AML_UART_TIMEOUT_USEC);
+	if (ret == -ETIMEDOUT)
+		dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
+
+out:
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops meson_uart_ops = {
+	.set_mctrl      = meson_uart_set_mctrl,
+	.get_mctrl      = meson_uart_get_mctrl,
+	.tx_empty	= meson_uart_tx_empty,
+	.start_tx	= meson_uart_start_tx,
+	.stop_tx	= meson_uart_stop_tx,
+	.stop_rx	= meson_uart_stop_rx,
+	.startup	= meson_uart_startup,
+	.shutdown	= meson_uart_shutdown,
+	.set_termios	= meson_uart_set_termios,
+	.type		= meson_uart_type,
+	.config_port	= meson_uart_config_port,
+	.request_port	= meson_uart_request_port,
+	.release_port	= meson_uart_release_port,
+	.verify_port	= meson_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= meson_uart_poll_get_char,
+	.poll_put_char	= meson_uart_poll_put_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_MESON_CONSOLE
+static void meson_uart_enable_tx_engine(struct uart_port *port)
+{
+	u32 val;
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val |= AML_UART_TX_EN;
+	writel(val, port->membase + AML_UART_CONTROL);
+}
+
+static void meson_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	if (!port->membase)
+		return;
+
+	while (readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)
+		cpu_relax();
+	writel(ch, port->membase + AML_UART_WFIFO);
+}
+
+static void meson_serial_port_write(struct uart_port *port, const char *s,
+				    u_int count)
+{
+	unsigned long flags;
+	int locked;
+	u32 val, tmp;
+
+	local_irq_save(flags);
+	if (port->sysrq) {
+		locked = 0;
+	} else if (oops_in_progress) {
+		locked = spin_trylock(&port->lock);
+	} else {
+		spin_lock(&port->lock);
+		locked = 1;
+	}
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN);
+	writel(tmp, port->membase + AML_UART_CONTROL);
+
+	uart_console_write(port, s, count, meson_console_putchar);
+	writel(val, port->membase + AML_UART_CONTROL);
+
+	if (locked)
+		spin_unlock(&port->lock);
+	local_irq_restore(flags);
+}
+
+static void meson_serial_console_write(struct console *co, const char *s,
+				       u_int count)
+{
+	struct uart_port *port;
+
+	port = meson_ports[co->index];
+	if (!port)
+		return;
+
+	meson_serial_port_write(port, s, count);
+}
+
+static int meson_serial_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= AML_UART_PORT_NUM)
+		return -EINVAL;
+
+	port = meson_ports[co->index];
+	if (!port || !port->membase)
+		return -ENODEV;
+
+	meson_uart_enable_tx_engine(port);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+#define MESON_SERIAL_CONSOLE(_devname)					\
+	static struct console meson_serial_console_##_devname = {	\
+		.name		= __stringify(_devname),		\
+		.write		= meson_serial_console_write,		\
+		.device		= uart_console_device,			\
+		.setup		= meson_serial_console_setup,		\
+		.flags		= CON_PRINTBUFFER,			\
+		.index		= -1,					\
+		.data		= &meson_uart_driver_##_devname,	\
+	}
+
+MESON_SERIAL_CONSOLE(ttyAML);
+MESON_SERIAL_CONSOLE(ttyS);
+
+static void meson_serial_early_console_write(struct console *co,
+					     const char *s,
+					     u_int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	meson_serial_port_write(&dev->port, s, count);
+}
+
+static int __init
+meson_serial_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	meson_uart_enable_tx_engine(&device->port);
+	device->con->write = meson_serial_early_console_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart",
+		    meson_serial_early_console_setup);
+
+#define MESON_SERIAL_CONSOLE_PTR(_devname) (&meson_serial_console_##_devname)
+#else
+#define MESON_SERIAL_CONSOLE_PTR(_devname) (NULL)
+#endif
+
+#define MESON_UART_DRIVER(_devname)					\
+	static struct uart_driver meson_uart_driver_##_devname = {	\
+		.owner		= THIS_MODULE,				\
+		.driver_name	= "meson_uart",				\
+		.dev_name	= __stringify(_devname),		\
+		.nr		= AML_UART_PORT_NUM,			\
+		.cons		= MESON_SERIAL_CONSOLE_PTR(_devname),	\
+	}
+
+MESON_UART_DRIVER(ttyAML);
+MESON_UART_DRIVER(ttyS);
+
+static int meson_uart_probe_clocks(struct platform_device *pdev,
+				   struct uart_port *port)
+{
+	struct clk *clk_xtal = NULL;
+	struct clk *clk_pclk = NULL;
+	struct clk *clk_baud = NULL;
+
+	clk_pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
+	if (IS_ERR(clk_pclk))
+		return PTR_ERR(clk_pclk);
+
+	clk_xtal = devm_clk_get_enabled(&pdev->dev, "xtal");
+	if (IS_ERR(clk_xtal))
+		return PTR_ERR(clk_xtal);
+
+	clk_baud = devm_clk_get_enabled(&pdev->dev, "baud");
+	if (IS_ERR(clk_baud))
+		return PTR_ERR(clk_baud);
+
+	port->uartclk = clk_get_rate(clk_baud);
+
+	return 0;
+}
+
+static struct uart_driver *meson_uart_current(const struct meson_uart_data *pd)
+{
+	return (pd && pd->uart_driver) ?
+		pd->uart_driver : &meson_uart_driver_ttyAML;
+}
+
+static int meson_uart_probe(struct platform_device *pdev)
+{
+	const struct meson_uart_data *priv_data;
+	struct uart_driver *uart_driver;
+	struct resource *res_mem;
+	struct uart_port *port;
+	u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
+	int ret = 0;
+	int irq;
+	bool has_rtscts;
+
+	if (pdev->dev.of_node)
+		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+
+	if (pdev->id < 0) {
+		int id;
+
+		for (id = AML_UART_PORT_OFFSET; id < AML_UART_PORT_NUM; id++) {
+			if (!meson_ports[id]) {
+				pdev->id = id;
+				break;
+			}
+		}
+	}
+
+	if (pdev->id < 0 || pdev->id >= AML_UART_PORT_NUM)
+		return -EINVAL;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem)
+		return -ENODEV;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
+	has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts");
+
+	if (meson_ports[pdev->id]) {
+		return dev_err_probe(&pdev->dev, -EBUSY,
+				     "port %d already allocated\n", pdev->id);
+	}
+
+	port = devm_kzalloc(&pdev->dev, sizeof(struct uart_port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	ret = meson_uart_probe_clocks(pdev, port);
+	if (ret)
+		return ret;
+
+	priv_data = device_get_match_data(&pdev->dev);
+
+	uart_driver = meson_uart_current(priv_data);
+
+	if (!uart_driver->state) {
+		ret = uart_register_driver(uart_driver);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					     "can't register uart driver\n");
+	}
+
+	port->iotype = UPIO_MEM;
+	port->mapbase = res_mem->start;
+	port->mapsize = resource_size(res_mem);
+	port->irq = irq;
+	port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
+	if (has_rtscts)
+		port->flags |= UPF_HARD_FLOW;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
+	port->dev = &pdev->dev;
+	port->line = pdev->id;
+	port->type = PORT_MESON;
+	port->x_char = 0;
+	port->ops = &meson_uart_ops;
+	port->fifosize = fifosize;
+	port->private_data = (void *)priv_data;
+
+	meson_ports[pdev->id] = port;
+	platform_set_drvdata(pdev, port);
+
+	/* reset port before registering (and possibly registering console) */
+	if (meson_uart_request_port(port) >= 0) {
+		meson_uart_reset(port);
+		meson_uart_release_port(port);
+	}
+
+	ret = uart_add_one_port(uart_driver, port);
+	if (ret)
+		meson_ports[pdev->id] = NULL;
+
+	return ret;
+}
+
+static int meson_uart_remove(struct platform_device *pdev)
+{
+	struct uart_driver *uart_driver;
+	struct uart_port *port;
+
+	port = platform_get_drvdata(pdev);
+	uart_driver = meson_uart_current(port->private_data);
+	uart_remove_one_port(uart_driver, port);
+	meson_ports[pdev->id] = NULL;
+
+	for (int id = 0; id < AML_UART_PORT_NUM; id++)
+		if (meson_ports[id])
+			return 0;
+
+	/* No more available uart ports, unregister uart driver */
+	uart_unregister_driver(uart_driver);
+
+	return 0;
+}
+
+static struct meson_uart_data meson_g12a_uart_data = {
+	.has_xtal_div2 = true,
+};
+
+static struct meson_uart_data meson_a1_uart_data = {
+	.uart_driver = &meson_uart_driver_ttyS,
+	.has_xtal_div2 = false,
+};
+
+static struct meson_uart_data meson_s4_uart_data = {
+	.uart_driver = &meson_uart_driver_ttyS,
+	.has_xtal_div2 = true,
+};
+
+static const struct of_device_id meson_uart_dt_match[] = {
+	{ .compatible = "amlogic,meson6-uart" },
+	{ .compatible = "amlogic,meson8-uart" },
+	{ .compatible = "amlogic,meson8b-uart" },
+	{ .compatible = "amlogic,meson-gx-uart" },
+	{
+		.compatible = "amlogic,meson-g12a-uart",
+		.data = (void *)&meson_g12a_uart_data,
+	},
+	{
+		.compatible = "amlogic,meson-s4-uart",
+		.data = (void *)&meson_s4_uart_data,
+	},
+	{
+		.compatible = "amlogic,meson-a1-uart",
+		.data = (void *)&meson_a1_uart_data,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_uart_dt_match);
+
+static  struct platform_driver meson_uart_platform_driver = {
+	.probe		= meson_uart_probe,
+	.remove		= meson_uart_remove,
+	.driver		= {
+		.name		= "meson_uart",
+		.of_match_table	= meson_uart_dt_match,
+	},
+};
+
+module_platform_driver(meson_uart_platform_driver);
+
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_DESCRIPTION("Amlogic Meson serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/milbeaut_usio.c b/drivers/tty/serial/milbeaut_usio.c
new file mode 100644
index 000000000..70a910085
--- /dev/null
+++ b/drivers/tty/serial/milbeaut_usio.c
@@ -0,0 +1,610 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Socionext Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define USIO_NAME		"mlb-usio-uart"
+#define USIO_UART_DEV_NAME	"ttyUSI"
+
+static struct uart_port mlb_usio_ports[CONFIG_SERIAL_MILBEAUT_USIO_PORTS];
+
+#define RX	0
+#define TX	1
+static int mlb_usio_irq[CONFIG_SERIAL_MILBEAUT_USIO_PORTS][2];
+
+#define MLB_USIO_REG_SMR		0
+#define MLB_USIO_REG_SCR		1
+#define MLB_USIO_REG_ESCR		2
+#define MLB_USIO_REG_SSR		3
+#define MLB_USIO_REG_DR			4
+#define MLB_USIO_REG_BGR		6
+#define MLB_USIO_REG_FCR		12
+#define MLB_USIO_REG_FBYTE		14
+
+#define MLB_USIO_SMR_SOE		BIT(0)
+#define MLB_USIO_SMR_SBL		BIT(3)
+#define MLB_USIO_SCR_TXE		BIT(0)
+#define MLB_USIO_SCR_RXE		BIT(1)
+#define MLB_USIO_SCR_TBIE		BIT(2)
+#define MLB_USIO_SCR_TIE		BIT(3)
+#define MLB_USIO_SCR_RIE		BIT(4)
+#define MLB_USIO_SCR_UPCL		BIT(7)
+#define MLB_USIO_ESCR_L_8BIT		0
+#define MLB_USIO_ESCR_L_5BIT		1
+#define MLB_USIO_ESCR_L_6BIT		2
+#define MLB_USIO_ESCR_L_7BIT		3
+#define MLB_USIO_ESCR_P			BIT(3)
+#define MLB_USIO_ESCR_PEN		BIT(4)
+#define MLB_USIO_ESCR_FLWEN		BIT(7)
+#define MLB_USIO_SSR_TBI		BIT(0)
+#define MLB_USIO_SSR_TDRE		BIT(1)
+#define MLB_USIO_SSR_RDRF		BIT(2)
+#define MLB_USIO_SSR_ORE		BIT(3)
+#define MLB_USIO_SSR_FRE		BIT(4)
+#define MLB_USIO_SSR_PE			BIT(5)
+#define MLB_USIO_SSR_REC		BIT(7)
+#define MLB_USIO_SSR_BRK		BIT(8)
+#define MLB_USIO_FCR_FE1		BIT(0)
+#define MLB_USIO_FCR_FE2		BIT(1)
+#define MLB_USIO_FCR_FCL1		BIT(2)
+#define MLB_USIO_FCR_FCL2		BIT(3)
+#define MLB_USIO_FCR_FSET		BIT(4)
+#define MLB_USIO_FCR_FTIE		BIT(9)
+#define MLB_USIO_FCR_FDRQ		BIT(10)
+#define MLB_USIO_FCR_FRIIE		BIT(11)
+
+static void mlb_usio_stop_tx(struct uart_port *port)
+{
+	writew(readw(port->membase + MLB_USIO_REG_FCR) & ~MLB_USIO_FCR_FTIE,
+	       port->membase + MLB_USIO_REG_FCR);
+	writeb(readb(port->membase + MLB_USIO_REG_SCR) & ~MLB_USIO_SCR_TBIE,
+	       port->membase + MLB_USIO_REG_SCR);
+}
+
+static void mlb_usio_tx_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	int count;
+
+	writew(readw(port->membase + MLB_USIO_REG_FCR) & ~MLB_USIO_FCR_FTIE,
+	       port->membase + MLB_USIO_REG_FCR);
+	writeb(readb(port->membase + MLB_USIO_REG_SCR) &
+	       ~(MLB_USIO_SCR_TIE | MLB_USIO_SCR_TBIE),
+	       port->membase + MLB_USIO_REG_SCR);
+
+	if (port->x_char) {
+		writew(port->x_char, port->membase + MLB_USIO_REG_DR);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		mlb_usio_stop_tx(port);
+		return;
+	}
+
+	count = port->fifosize -
+		(readw(port->membase + MLB_USIO_REG_FBYTE) & 0xff);
+
+	do {
+		writew(xmit->buf[xmit->tail], port->membase + MLB_USIO_REG_DR);
+
+		uart_xmit_advance(port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+
+	} while (--count > 0);
+
+	writew(readw(port->membase + MLB_USIO_REG_FCR) & ~MLB_USIO_FCR_FDRQ,
+	       port->membase + MLB_USIO_REG_FCR);
+
+	writeb(readb(port->membase + MLB_USIO_REG_SCR) | MLB_USIO_SCR_TBIE,
+	       port->membase + MLB_USIO_REG_SCR);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		mlb_usio_stop_tx(port);
+}
+
+static void mlb_usio_start_tx(struct uart_port *port)
+{
+	u16 fcr = readw(port->membase + MLB_USIO_REG_FCR);
+
+	writew(fcr | MLB_USIO_FCR_FTIE, port->membase + MLB_USIO_REG_FCR);
+	if (!(fcr & MLB_USIO_FCR_FDRQ))
+		return;
+
+	writeb(readb(port->membase + MLB_USIO_REG_SCR) | MLB_USIO_SCR_TBIE,
+	       port->membase + MLB_USIO_REG_SCR);
+
+	if (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI)
+		mlb_usio_tx_chars(port);
+}
+
+static void mlb_usio_stop_rx(struct uart_port *port)
+{
+	writeb(readb(port->membase + MLB_USIO_REG_SCR) & ~MLB_USIO_SCR_RIE,
+	       port->membase + MLB_USIO_REG_SCR);
+}
+
+static void mlb_usio_enable_ms(struct uart_port *port)
+{
+	writeb(readb(port->membase + MLB_USIO_REG_SCR) |
+	       MLB_USIO_SCR_RIE | MLB_USIO_SCR_RXE,
+	       port->membase + MLB_USIO_REG_SCR);
+}
+
+static void mlb_usio_rx_chars(struct uart_port *port)
+{
+	struct tty_port *ttyport = &port->state->port;
+	u8 flag = 0, ch = 0;
+	u8 status;
+	int max_count = 2;
+
+	while (max_count--) {
+		status = readb(port->membase + MLB_USIO_REG_SSR);
+
+		if (!(status & MLB_USIO_SSR_RDRF))
+			break;
+
+		if (!(status & (MLB_USIO_SSR_ORE | MLB_USIO_SSR_FRE |
+				MLB_USIO_SSR_PE))) {
+			ch = readw(port->membase + MLB_USIO_REG_DR);
+			flag = TTY_NORMAL;
+			port->icount.rx++;
+			if (uart_handle_sysrq_char(port, ch))
+				continue;
+			uart_insert_char(port, status, MLB_USIO_SSR_ORE,
+					 ch, flag);
+			continue;
+		}
+		if (status & MLB_USIO_SSR_PE)
+			port->icount.parity++;
+		if (status & MLB_USIO_SSR_ORE)
+			port->icount.overrun++;
+		status &= port->read_status_mask;
+		if (status & MLB_USIO_SSR_BRK) {
+			flag = TTY_BREAK;
+			ch = 0;
+		} else
+			if (status & MLB_USIO_SSR_PE) {
+				flag = TTY_PARITY;
+				ch = 0;
+			} else
+				if (status & MLB_USIO_SSR_FRE) {
+					flag = TTY_FRAME;
+					ch = 0;
+				}
+		if (flag)
+			uart_insert_char(port, status, MLB_USIO_SSR_ORE,
+					 ch, flag);
+
+		writeb(readb(port->membase + MLB_USIO_REG_SSR) |
+				MLB_USIO_SSR_REC,
+				port->membase + MLB_USIO_REG_SSR);
+
+		max_count = readw(port->membase + MLB_USIO_REG_FBYTE) >> 8;
+		writew(readw(port->membase + MLB_USIO_REG_FCR) |
+		       MLB_USIO_FCR_FE2 | MLB_USIO_FCR_FRIIE,
+		port->membase + MLB_USIO_REG_FCR);
+	}
+
+	tty_flip_buffer_push(ttyport);
+}
+
+static irqreturn_t mlb_usio_rx_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+
+	spin_lock(&port->lock);
+	mlb_usio_rx_chars(port);
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mlb_usio_tx_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+
+	spin_lock(&port->lock);
+	if (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI)
+		mlb_usio_tx_chars(port);
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int mlb_usio_tx_empty(struct uart_port *port)
+{
+	return (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI) ?
+		TIOCSER_TEMT : 0;
+}
+
+static void mlb_usio_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int mlb_usio_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+
+}
+
+static void mlb_usio_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int mlb_usio_startup(struct uart_port *port)
+{
+	const char *portname = to_platform_device(port->dev)->name;
+	unsigned long flags;
+	int ret, index = port->line;
+	unsigned char  escr;
+
+	ret = request_irq(mlb_usio_irq[index][RX], mlb_usio_rx_irq,
+				0, portname, port);
+	if (ret)
+		return ret;
+	ret = request_irq(mlb_usio_irq[index][TX], mlb_usio_tx_irq,
+				0, portname, port);
+	if (ret) {
+		free_irq(mlb_usio_irq[index][RX], port);
+		return ret;
+	}
+
+	escr = readb(port->membase + MLB_USIO_REG_ESCR);
+	if (of_property_read_bool(port->dev->of_node, "auto-flow-control"))
+		escr |= MLB_USIO_ESCR_FLWEN;
+	spin_lock_irqsave(&port->lock, flags);
+	writeb(0, port->membase + MLB_USIO_REG_SCR);
+	writeb(escr, port->membase + MLB_USIO_REG_ESCR);
+	writeb(MLB_USIO_SCR_UPCL, port->membase + MLB_USIO_REG_SCR);
+	writeb(MLB_USIO_SSR_REC, port->membase + MLB_USIO_REG_SSR);
+	writew(0, port->membase + MLB_USIO_REG_FCR);
+	writew(MLB_USIO_FCR_FCL1 | MLB_USIO_FCR_FCL2,
+	       port->membase + MLB_USIO_REG_FCR);
+	writew(MLB_USIO_FCR_FE1 | MLB_USIO_FCR_FE2 | MLB_USIO_FCR_FRIIE,
+	       port->membase + MLB_USIO_REG_FCR);
+	writew(0, port->membase + MLB_USIO_REG_FBYTE);
+	writew(BIT(12), port->membase + MLB_USIO_REG_FBYTE);
+
+	writeb(MLB_USIO_SCR_TXE  | MLB_USIO_SCR_RIE | MLB_USIO_SCR_TBIE |
+	       MLB_USIO_SCR_RXE, port->membase + MLB_USIO_REG_SCR);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void mlb_usio_shutdown(struct uart_port *port)
+{
+	int index = port->line;
+
+	free_irq(mlb_usio_irq[index][RX], port);
+	free_irq(mlb_usio_irq[index][TX], port);
+}
+
+static void mlb_usio_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	unsigned int escr, smr = MLB_USIO_SMR_SOE;
+	unsigned long flags, baud, quot;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		escr = MLB_USIO_ESCR_L_5BIT;
+		break;
+	case CS6:
+		escr = MLB_USIO_ESCR_L_6BIT;
+		break;
+	case CS7:
+		escr = MLB_USIO_ESCR_L_7BIT;
+		break;
+	case CS8:
+	default:
+		escr = MLB_USIO_ESCR_L_8BIT;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		smr |= MLB_USIO_SMR_SBL;
+
+	if (termios->c_cflag & PARENB) {
+		escr |= MLB_USIO_ESCR_PEN;
+		if (termios->c_cflag & PARODD)
+			escr |= MLB_USIO_ESCR_P;
+	}
+	/* Set hard flow control */
+	if (of_property_read_bool(port->dev->of_node, "auto-flow-control") ||
+			(termios->c_cflag & CRTSCTS))
+		escr |= MLB_USIO_ESCR_FLWEN;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk);
+	if (baud > 1)
+		quot = port->uartclk / baud - 1;
+	else
+		quot = 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_update_timeout(port, termios->c_cflag, baud);
+	port->read_status_mask = MLB_USIO_SSR_ORE | MLB_USIO_SSR_RDRF |
+				 MLB_USIO_SSR_TDRE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= MLB_USIO_SSR_FRE | MLB_USIO_SSR_PE;
+
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= MLB_USIO_SSR_FRE | MLB_USIO_SSR_PE;
+	if ((termios->c_iflag & IGNBRK) && (termios->c_iflag & IGNPAR))
+		port->ignore_status_mask |= MLB_USIO_SSR_ORE;
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= MLB_USIO_SSR_RDRF;
+
+	writeb(0, port->membase + MLB_USIO_REG_SCR);
+	writeb(MLB_USIO_SCR_UPCL, port->membase + MLB_USIO_REG_SCR);
+	writeb(MLB_USIO_SSR_REC, port->membase + MLB_USIO_REG_SSR);
+	writew(0, port->membase + MLB_USIO_REG_FCR);
+	writeb(smr, port->membase + MLB_USIO_REG_SMR);
+	writeb(escr, port->membase + MLB_USIO_REG_ESCR);
+	writew(quot, port->membase + MLB_USIO_REG_BGR);
+	writew(0, port->membase + MLB_USIO_REG_FCR);
+	writew(MLB_USIO_FCR_FCL1 | MLB_USIO_FCR_FCL2 | MLB_USIO_FCR_FE1 |
+	       MLB_USIO_FCR_FE2 | MLB_USIO_FCR_FRIIE,
+	       port->membase + MLB_USIO_REG_FCR);
+	writew(0, port->membase + MLB_USIO_REG_FBYTE);
+	writew(BIT(12), port->membase + MLB_USIO_REG_FBYTE);
+	writeb(MLB_USIO_SCR_RIE | MLB_USIO_SCR_RXE | MLB_USIO_SCR_TBIE |
+	       MLB_USIO_SCR_TXE, port->membase + MLB_USIO_REG_SCR);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *mlb_usio_type(struct uart_port *port)
+{
+	return ((port->type == PORT_MLB_USIO) ? USIO_NAME : NULL);
+}
+
+static void mlb_usio_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_MLB_USIO;
+}
+
+static const struct uart_ops mlb_usio_ops = {
+	.tx_empty	= mlb_usio_tx_empty,
+	.set_mctrl	= mlb_usio_set_mctrl,
+	.get_mctrl	= mlb_usio_get_mctrl,
+	.stop_tx	= mlb_usio_stop_tx,
+	.start_tx	= mlb_usio_start_tx,
+	.stop_rx	= mlb_usio_stop_rx,
+	.enable_ms	= mlb_usio_enable_ms,
+	.break_ctl	= mlb_usio_break_ctl,
+	.startup	= mlb_usio_startup,
+	.shutdown	= mlb_usio_shutdown,
+	.set_termios	= mlb_usio_set_termios,
+	.type		= mlb_usio_type,
+	.config_port	= mlb_usio_config_port,
+};
+
+#ifdef CONFIG_SERIAL_MILBEAUT_USIO_CONSOLE
+
+static void mlb_usio_console_putchar(struct uart_port *port, unsigned char c)
+{
+	while (!(readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TDRE))
+		cpu_relax();
+
+	writew(c, port->membase + MLB_USIO_REG_DR);
+}
+
+static void mlb_usio_console_write(struct console *co, const char *s,
+			       unsigned int count)
+{
+	struct uart_port *port = &mlb_usio_ports[co->index];
+
+	uart_console_write(port, s, count, mlb_usio_console_putchar);
+}
+
+static int __init mlb_usio_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int parity = 'n';
+	int flow = 'n';
+	int bits = 8;
+
+	if (co->index >= CONFIG_SERIAL_MILBEAUT_USIO_PORTS)
+		return -ENODEV;
+
+	port = &mlb_usio_ports[co->index];
+	if (!port->membase)
+		return -ENODEV;
+
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	if (of_property_read_bool(port->dev->of_node, "auto-flow-control"))
+		flow = 'r';
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+
+static struct uart_driver mlb_usio_uart_driver;
+static struct console mlb_usio_console = {
+	.name   = USIO_UART_DEV_NAME,
+	.write  = mlb_usio_console_write,
+	.device = uart_console_device,
+	.setup  = mlb_usio_console_setup,
+	.flags  = CON_PRINTBUFFER,
+	.index  = -1,
+	.data   = &mlb_usio_uart_driver,
+};
+
+static int __init mlb_usio_console_init(void)
+{
+	register_console(&mlb_usio_console);
+	return 0;
+}
+console_initcall(mlb_usio_console_init);
+
+
+static void mlb_usio_early_console_write(struct console *co, const char *s,
+					u_int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	uart_console_write(&dev->port, s, count, mlb_usio_console_putchar);
+}
+
+static int __init mlb_usio_early_console_setup(struct earlycon_device *device,
+						const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+	device->con->write = mlb_usio_early_console_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(mlb_usio, "socionext,milbeaut-usio-uart",
+			mlb_usio_early_console_setup);
+
+#define USIO_CONSOLE	(&mlb_usio_console)
+#else
+#define USIO_CONSOLE	NULL
+#endif
+
+static struct  uart_driver mlb_usio_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= USIO_NAME,
+	.dev_name	= USIO_UART_DEV_NAME,
+	.cons           = USIO_CONSOLE,
+	.nr		= CONFIG_SERIAL_MILBEAUT_USIO_PORTS,
+};
+
+static int mlb_usio_probe(struct platform_device *pdev)
+{
+	struct clk *clk = devm_clk_get(&pdev->dev, NULL);
+	struct uart_port *port;
+	struct resource *res;
+	int index = 0;
+	int ret;
+
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "Missing clock\n");
+		return PTR_ERR(clk);
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Clock enable failed: %d\n", ret);
+		return ret;
+	}
+	of_property_read_u32(pdev->dev.of_node, "index", &index);
+	port = &mlb_usio_ports[index];
+
+	port->private_data = (void *)clk;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "Missing regs\n");
+		ret = -ENODEV;
+		goto failed;
+	}
+	port->membase = devm_ioremap(&pdev->dev, res->start,
+				resource_size(res));
+
+	ret = platform_get_irq_byname(pdev, "rx");
+	mlb_usio_irq[index][RX] = ret;
+
+	ret = platform_get_irq_byname(pdev, "tx");
+	mlb_usio_irq[index][TX] = ret;
+
+	port->irq = mlb_usio_irq[index][RX];
+	port->uartclk = clk_get_rate(clk);
+	port->fifosize = 128;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MILBEAUT_USIO_CONSOLE);
+	port->iotype = UPIO_MEM32;
+	port->flags = UPF_BOOT_AUTOCONF | UPF_SPD_VHI;
+	port->line = index;
+	port->ops = &mlb_usio_ops;
+	port->dev = &pdev->dev;
+
+	ret = uart_add_one_port(&mlb_usio_uart_driver, port);
+	if (ret) {
+		dev_err(&pdev->dev, "Adding port failed: %d\n", ret);
+		goto failed;
+	}
+	return 0;
+
+failed:
+	clk_disable_unprepare(clk);
+
+	return ret;
+}
+
+static int mlb_usio_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = &mlb_usio_ports[pdev->id];
+	struct clk *clk = port->private_data;
+
+	uart_remove_one_port(&mlb_usio_uart_driver, port);
+	clk_disable_unprepare(clk);
+
+	return 0;
+}
+
+static const struct of_device_id mlb_usio_dt_ids[] = {
+	{ .compatible = "socionext,milbeaut-usio-uart" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mlb_usio_dt_ids);
+
+static struct platform_driver mlb_usio_driver = {
+	.probe          = mlb_usio_probe,
+	.remove         = mlb_usio_remove,
+	.driver         = {
+		.name   = USIO_NAME,
+		.of_match_table = mlb_usio_dt_ids,
+	},
+};
+
+static int __init mlb_usio_init(void)
+{
+	int ret = uart_register_driver(&mlb_usio_uart_driver);
+
+	if (ret) {
+		pr_err("%s: uart registration failed: %d\n", __func__, ret);
+		return ret;
+	}
+	ret = platform_driver_register(&mlb_usio_driver);
+	if (ret) {
+		uart_unregister_driver(&mlb_usio_uart_driver);
+		pr_err("%s: drv registration failed: %d\n", __func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit mlb_usio_exit(void)
+{
+	platform_driver_unregister(&mlb_usio_driver);
+	uart_unregister_driver(&mlb_usio_uart_driver);
+}
+
+module_init(mlb_usio_init);
+module_exit(mlb_usio_exit);
+
+MODULE_AUTHOR("SOCIONEXT");
+MODULE_DESCRIPTION("MILBEAUT_USIO/UART Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
new file mode 100644
index 000000000..916507b8f
--- /dev/null
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -0,0 +1,1922 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the PSC of the Freescale MPC52xx PSCs configured as UARTs.
+ *
+ * FIXME According to the usermanual the status bits in the status register
+ * are only updated when the peripherals access the FIFO and not when the
+ * CPU access them. So since we use this bits to know when we stop writing
+ * and reading, they may not be updated in-time and a race condition may
+ * exists. But I haven't be able to prove this and I don't care. But if
+ * any problem arises, it might worth checking. The TX/RX FIFO Stats
+ * registers should be used in addition.
+ * Update: Actually, they seem updated ... At least the bits we use.
+ *
+ *
+ * Maintainer : Sylvain Munaut <tnt@246tNt.com>
+ *
+ * Some of the code has been inspired/copied from the 2.4 code written
+ * by Dale Farnsworth <dfarnsworth@mvista.com>.
+ *
+ * Copyright (C) 2008 Freescale Semiconductor Inc.
+ *                    John Rigby <jrigby@gmail.com>
+ * Added support for MPC5121
+ * Copyright (C) 2006 Secret Lab Technologies Ltd.
+ *                    Grant Likely <grant.likely@secretlab.ca>
+ * Copyright (C) 2004-2006 Sylvain Munaut <tnt@246tNt.com>
+ * Copyright (C) 2003 MontaVista, Software, Inc.
+ */
+
+#undef DEBUG
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <asm/mpc52xx.h>
+#include <asm/mpc52xx_psc.h>
+
+#include <linux/serial_core.h>
+
+
+/* We've been assigned a range on the "Low-density serial ports" major */
+#define SERIAL_PSC_MAJOR	204
+#define SERIAL_PSC_MINOR	148
+
+
+#define ISR_PASS_LIMIT 256	/* Max number of iteration in the interrupt */
+
+
+static struct uart_port mpc52xx_uart_ports[MPC52xx_PSC_MAXNUM];
+	/* Rem: - We use the read_status_mask as a shadow of
+	 *        psc->mpc52xx_psc_imr
+	 *      - It's important that is array is all zero on start as we
+	 *        use it to know if it's initialized or not ! If it's not sure
+	 *        it's cleared, then a memset(...,0,...) should be added to
+	 *        the console_init
+	 */
+
+/* lookup table for matching device nodes to index numbers */
+static struct device_node *mpc52xx_uart_nodes[MPC52xx_PSC_MAXNUM];
+
+static void mpc52xx_uart_of_enumerate(void);
+
+
+#define PSC(port) ((struct mpc52xx_psc __iomem *)((port)->membase))
+
+
+/* Forward declaration of the interruption handling routine */
+static irqreturn_t mpc52xx_uart_int(int irq, void *dev_id);
+static irqreturn_t mpc5xxx_uart_process_int(struct uart_port *port);
+
+/* ======================================================================== */
+/* PSC fifo operations for isolating differences between 52xx and 512x      */
+/* ======================================================================== */
+
+struct psc_ops {
+	void		(*fifo_init)(struct uart_port *port);
+	unsigned int	(*raw_rx_rdy)(struct uart_port *port);
+	unsigned int	(*raw_tx_rdy)(struct uart_port *port);
+	unsigned int	(*rx_rdy)(struct uart_port *port);
+	unsigned int	(*tx_rdy)(struct uart_port *port);
+	unsigned int	(*tx_empty)(struct uart_port *port);
+	void		(*stop_rx)(struct uart_port *port);
+	void		(*start_tx)(struct uart_port *port);
+	void		(*stop_tx)(struct uart_port *port);
+	void		(*rx_clr_irq)(struct uart_port *port);
+	void		(*tx_clr_irq)(struct uart_port *port);
+	void		(*write_char)(struct uart_port *port, unsigned char c);
+	unsigned char	(*read_char)(struct uart_port *port);
+	void		(*cw_disable_ints)(struct uart_port *port);
+	void		(*cw_restore_ints)(struct uart_port *port);
+	unsigned int	(*set_baudrate)(struct uart_port *port,
+					struct ktermios *new,
+					const struct ktermios *old);
+	int		(*clock_alloc)(struct uart_port *port);
+	void		(*clock_relse)(struct uart_port *port);
+	int		(*clock)(struct uart_port *port, int enable);
+	int		(*fifoc_init)(void);
+	void		(*fifoc_uninit)(void);
+	void		(*get_irq)(struct uart_port *, struct device_node *);
+	irqreturn_t	(*handle_irq)(struct uart_port *port);
+	u16		(*get_status)(struct uart_port *port);
+	u8		(*get_ipcr)(struct uart_port *port);
+	void		(*command)(struct uart_port *port, u8 cmd);
+	void		(*set_mode)(struct uart_port *port, u8 mr1, u8 mr2);
+	void		(*set_rts)(struct uart_port *port, int state);
+	void		(*enable_ms)(struct uart_port *port);
+	void		(*set_sicr)(struct uart_port *port, u32 val);
+	void		(*set_imr)(struct uart_port *port, u16 val);
+	u8		(*get_mr1)(struct uart_port *port);
+};
+
+/* setting the prescaler and divisor reg is common for all chips */
+static inline void mpc52xx_set_divisor(struct mpc52xx_psc __iomem *psc,
+				       u16 prescaler, unsigned int divisor)
+{
+	/* select prescaler */
+	out_be16(&psc->mpc52xx_psc_clock_select, prescaler);
+	out_8(&psc->ctur, divisor >> 8);
+	out_8(&psc->ctlr, divisor & 0xff);
+}
+
+static u16 mpc52xx_psc_get_status(struct uart_port *port)
+{
+	return in_be16(&PSC(port)->mpc52xx_psc_status);
+}
+
+static u8 mpc52xx_psc_get_ipcr(struct uart_port *port)
+{
+	return in_8(&PSC(port)->mpc52xx_psc_ipcr);
+}
+
+static void mpc52xx_psc_command(struct uart_port *port, u8 cmd)
+{
+	out_8(&PSC(port)->command, cmd);
+}
+
+static void mpc52xx_psc_set_mode(struct uart_port *port, u8 mr1, u8 mr2)
+{
+	out_8(&PSC(port)->command, MPC52xx_PSC_SEL_MODE_REG_1);
+	out_8(&PSC(port)->mode, mr1);
+	out_8(&PSC(port)->mode, mr2);
+}
+
+static void mpc52xx_psc_set_rts(struct uart_port *port, int state)
+{
+	if (state)
+		out_8(&PSC(port)->op1, MPC52xx_PSC_OP_RTS);
+	else
+		out_8(&PSC(port)->op0, MPC52xx_PSC_OP_RTS);
+}
+
+static void mpc52xx_psc_enable_ms(struct uart_port *port)
+{
+	struct mpc52xx_psc __iomem *psc = PSC(port);
+
+	/* clear D_*-bits by reading them */
+	in_8(&psc->mpc52xx_psc_ipcr);
+	/* enable CTS and DCD as IPC interrupts */
+	out_8(&psc->mpc52xx_psc_acr, MPC52xx_PSC_IEC_CTS | MPC52xx_PSC_IEC_DCD);
+
+	port->read_status_mask |= MPC52xx_PSC_IMR_IPC;
+	out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static void mpc52xx_psc_set_sicr(struct uart_port *port, u32 val)
+{
+	out_be32(&PSC(port)->sicr, val);
+}
+
+static void mpc52xx_psc_set_imr(struct uart_port *port, u16 val)
+{
+	out_be16(&PSC(port)->mpc52xx_psc_imr, val);
+}
+
+static u8 mpc52xx_psc_get_mr1(struct uart_port *port)
+{
+	out_8(&PSC(port)->command, MPC52xx_PSC_SEL_MODE_REG_1);
+	return in_8(&PSC(port)->mode);
+}
+
+#ifdef CONFIG_PPC_MPC52xx
+#define FIFO_52xx(port) ((struct mpc52xx_psc_fifo __iomem *)(PSC(port)+1))
+static void mpc52xx_psc_fifo_init(struct uart_port *port)
+{
+	struct mpc52xx_psc __iomem *psc = PSC(port);
+	struct mpc52xx_psc_fifo __iomem *fifo = FIFO_52xx(port);
+
+	out_8(&fifo->rfcntl, 0x00);
+	out_be16(&fifo->rfalarm, 0x1ff);
+	out_8(&fifo->tfcntl, 0x07);
+	out_be16(&fifo->tfalarm, 0x80);
+
+	port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY;
+	out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static unsigned int mpc52xx_psc_raw_rx_rdy(struct uart_port *port)
+{
+	return in_be16(&PSC(port)->mpc52xx_psc_status)
+	    & MPC52xx_PSC_SR_RXRDY;
+}
+
+static unsigned int mpc52xx_psc_raw_tx_rdy(struct uart_port *port)
+{
+	return in_be16(&PSC(port)->mpc52xx_psc_status)
+	    & MPC52xx_PSC_SR_TXRDY;
+}
+
+
+static unsigned int mpc52xx_psc_rx_rdy(struct uart_port *port)
+{
+	return in_be16(&PSC(port)->mpc52xx_psc_isr)
+	    & port->read_status_mask
+	    & MPC52xx_PSC_IMR_RXRDY;
+}
+
+static unsigned int mpc52xx_psc_tx_rdy(struct uart_port *port)
+{
+	return in_be16(&PSC(port)->mpc52xx_psc_isr)
+	    & port->read_status_mask
+	    & MPC52xx_PSC_IMR_TXRDY;
+}
+
+static unsigned int mpc52xx_psc_tx_empty(struct uart_port *port)
+{
+	u16 sts = in_be16(&PSC(port)->mpc52xx_psc_status);
+
+	return (sts & MPC52xx_PSC_SR_TXEMP) ? TIOCSER_TEMT : 0;
+}
+
+static void mpc52xx_psc_start_tx(struct uart_port *port)
+{
+	port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
+	out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static void mpc52xx_psc_stop_tx(struct uart_port *port)
+{
+	port->read_status_mask &= ~MPC52xx_PSC_IMR_TXRDY;
+	out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static void mpc52xx_psc_stop_rx(struct uart_port *port)
+{
+	port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY;
+	out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static void mpc52xx_psc_rx_clr_irq(struct uart_port *port)
+{
+}
+
+static void mpc52xx_psc_tx_clr_irq(struct uart_port *port)
+{
+}
+
+static void mpc52xx_psc_write_char(struct uart_port *port, unsigned char c)
+{
+	out_8(&PSC(port)->mpc52xx_psc_buffer_8, c);
+}
+
+static unsigned char mpc52xx_psc_read_char(struct uart_port *port)
+{
+	return in_8(&PSC(port)->mpc52xx_psc_buffer_8);
+}
+
+static void mpc52xx_psc_cw_disable_ints(struct uart_port *port)
+{
+	out_be16(&PSC(port)->mpc52xx_psc_imr, 0);
+}
+
+static void mpc52xx_psc_cw_restore_ints(struct uart_port *port)
+{
+	out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static unsigned int mpc5200_psc_set_baudrate(struct uart_port *port,
+					     struct ktermios *new,
+					     const struct ktermios *old)
+{
+	unsigned int baud;
+	unsigned int divisor;
+
+	/* The 5200 has a fixed /32 prescaler, uartclk contains the ipb freq */
+	baud = uart_get_baud_rate(port, new, old,
+				  port->uartclk / (32 * 0xffff) + 1,
+				  port->uartclk / 32);
+	divisor = (port->uartclk + 16 * baud) / (32 * baud);
+
+	/* enable the /32 prescaler and set the divisor */
+	mpc52xx_set_divisor(PSC(port), 0xdd00, divisor);
+	return baud;
+}
+
+static unsigned int mpc5200b_psc_set_baudrate(struct uart_port *port,
+					      struct ktermios *new,
+					      const struct ktermios *old)
+{
+	unsigned int baud;
+	unsigned int divisor;
+	u16 prescaler;
+
+	/* The 5200B has a selectable /4 or /32 prescaler, uartclk contains the
+	 * ipb freq */
+	baud = uart_get_baud_rate(port, new, old,
+				  port->uartclk / (32 * 0xffff) + 1,
+				  port->uartclk / 4);
+	divisor = (port->uartclk + 2 * baud) / (4 * baud);
+
+	/* select the proper prescaler and set the divisor
+	 * prefer high prescaler for more tolerance on low baudrates */
+	if (divisor > 0xffff || baud <= 115200) {
+		divisor = (divisor + 4) / 8;
+		prescaler = 0xdd00; /* /32 */
+	} else
+		prescaler = 0xff00; /* /4 */
+	mpc52xx_set_divisor(PSC(port), prescaler, divisor);
+	return baud;
+}
+
+static void mpc52xx_psc_get_irq(struct uart_port *port, struct device_node *np)
+{
+	port->irqflags = 0;
+	port->irq = irq_of_parse_and_map(np, 0);
+}
+
+/* 52xx specific interrupt handler. The caller holds the port lock */
+static irqreturn_t mpc52xx_psc_handle_irq(struct uart_port *port)
+{
+	return mpc5xxx_uart_process_int(port);
+}
+
+static const struct psc_ops mpc52xx_psc_ops = {
+	.fifo_init = mpc52xx_psc_fifo_init,
+	.raw_rx_rdy = mpc52xx_psc_raw_rx_rdy,
+	.raw_tx_rdy = mpc52xx_psc_raw_tx_rdy,
+	.rx_rdy = mpc52xx_psc_rx_rdy,
+	.tx_rdy = mpc52xx_psc_tx_rdy,
+	.tx_empty = mpc52xx_psc_tx_empty,
+	.stop_rx = mpc52xx_psc_stop_rx,
+	.start_tx = mpc52xx_psc_start_tx,
+	.stop_tx = mpc52xx_psc_stop_tx,
+	.rx_clr_irq = mpc52xx_psc_rx_clr_irq,
+	.tx_clr_irq = mpc52xx_psc_tx_clr_irq,
+	.write_char = mpc52xx_psc_write_char,
+	.read_char = mpc52xx_psc_read_char,
+	.cw_disable_ints = mpc52xx_psc_cw_disable_ints,
+	.cw_restore_ints = mpc52xx_psc_cw_restore_ints,
+	.set_baudrate = mpc5200_psc_set_baudrate,
+	.get_irq = mpc52xx_psc_get_irq,
+	.handle_irq = mpc52xx_psc_handle_irq,
+	.get_status = mpc52xx_psc_get_status,
+	.get_ipcr = mpc52xx_psc_get_ipcr,
+	.command = mpc52xx_psc_command,
+	.set_mode = mpc52xx_psc_set_mode,
+	.set_rts = mpc52xx_psc_set_rts,
+	.enable_ms = mpc52xx_psc_enable_ms,
+	.set_sicr = mpc52xx_psc_set_sicr,
+	.set_imr = mpc52xx_psc_set_imr,
+	.get_mr1 = mpc52xx_psc_get_mr1,
+};
+
+static const struct psc_ops mpc5200b_psc_ops = {
+	.fifo_init = mpc52xx_psc_fifo_init,
+	.raw_rx_rdy = mpc52xx_psc_raw_rx_rdy,
+	.raw_tx_rdy = mpc52xx_psc_raw_tx_rdy,
+	.rx_rdy = mpc52xx_psc_rx_rdy,
+	.tx_rdy = mpc52xx_psc_tx_rdy,
+	.tx_empty = mpc52xx_psc_tx_empty,
+	.stop_rx = mpc52xx_psc_stop_rx,
+	.start_tx = mpc52xx_psc_start_tx,
+	.stop_tx = mpc52xx_psc_stop_tx,
+	.rx_clr_irq = mpc52xx_psc_rx_clr_irq,
+	.tx_clr_irq = mpc52xx_psc_tx_clr_irq,
+	.write_char = mpc52xx_psc_write_char,
+	.read_char = mpc52xx_psc_read_char,
+	.cw_disable_ints = mpc52xx_psc_cw_disable_ints,
+	.cw_restore_ints = mpc52xx_psc_cw_restore_ints,
+	.set_baudrate = mpc5200b_psc_set_baudrate,
+	.get_irq = mpc52xx_psc_get_irq,
+	.handle_irq = mpc52xx_psc_handle_irq,
+	.get_status = mpc52xx_psc_get_status,
+	.get_ipcr = mpc52xx_psc_get_ipcr,
+	.command = mpc52xx_psc_command,
+	.set_mode = mpc52xx_psc_set_mode,
+	.set_rts = mpc52xx_psc_set_rts,
+	.enable_ms = mpc52xx_psc_enable_ms,
+	.set_sicr = mpc52xx_psc_set_sicr,
+	.set_imr = mpc52xx_psc_set_imr,
+	.get_mr1 = mpc52xx_psc_get_mr1,
+};
+
+#endif /* CONFIG_PPC_MPC52xx */
+
+#ifdef CONFIG_PPC_MPC512x
+#define FIFO_512x(port) ((struct mpc512x_psc_fifo __iomem *)(PSC(port)+1))
+
+/* PSC FIFO Controller for mpc512x */
+struct psc_fifoc {
+	u32 fifoc_cmd;
+	u32 fifoc_int;
+	u32 fifoc_dma;
+	u32 fifoc_axe;
+	u32 fifoc_debug;
+};
+
+static struct psc_fifoc __iomem *psc_fifoc;
+static unsigned int psc_fifoc_irq;
+static struct clk *psc_fifoc_clk;
+
+static void mpc512x_psc_fifo_init(struct uart_port *port)
+{
+	/* /32 prescaler */
+	out_be16(&PSC(port)->mpc52xx_psc_clock_select, 0xdd00);
+
+	out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_RESET_SLICE);
+	out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
+	out_be32(&FIFO_512x(port)->txalarm, 1);
+	out_be32(&FIFO_512x(port)->tximr, 0);
+
+	out_be32(&FIFO_512x(port)->rxcmd, MPC512x_PSC_FIFO_RESET_SLICE);
+	out_be32(&FIFO_512x(port)->rxcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
+	out_be32(&FIFO_512x(port)->rxalarm, 1);
+	out_be32(&FIFO_512x(port)->rximr, 0);
+
+	out_be32(&FIFO_512x(port)->tximr, MPC512x_PSC_FIFO_ALARM);
+	out_be32(&FIFO_512x(port)->rximr, MPC512x_PSC_FIFO_ALARM);
+}
+
+static unsigned int mpc512x_psc_raw_rx_rdy(struct uart_port *port)
+{
+	return !(in_be32(&FIFO_512x(port)->rxsr) & MPC512x_PSC_FIFO_EMPTY);
+}
+
+static unsigned int mpc512x_psc_raw_tx_rdy(struct uart_port *port)
+{
+	return !(in_be32(&FIFO_512x(port)->txsr) & MPC512x_PSC_FIFO_FULL);
+}
+
+static unsigned int mpc512x_psc_rx_rdy(struct uart_port *port)
+{
+	return in_be32(&FIFO_512x(port)->rxsr)
+	    & in_be32(&FIFO_512x(port)->rximr)
+	    & MPC512x_PSC_FIFO_ALARM;
+}
+
+static unsigned int mpc512x_psc_tx_rdy(struct uart_port *port)
+{
+	return in_be32(&FIFO_512x(port)->txsr)
+	    & in_be32(&FIFO_512x(port)->tximr)
+	    & MPC512x_PSC_FIFO_ALARM;
+}
+
+static unsigned int mpc512x_psc_tx_empty(struct uart_port *port)
+{
+	return in_be32(&FIFO_512x(port)->txsr)
+	    & MPC512x_PSC_FIFO_EMPTY;
+}
+
+static void mpc512x_psc_stop_rx(struct uart_port *port)
+{
+	unsigned long rx_fifo_imr;
+
+	rx_fifo_imr = in_be32(&FIFO_512x(port)->rximr);
+	rx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM;
+	out_be32(&FIFO_512x(port)->rximr, rx_fifo_imr);
+}
+
+static void mpc512x_psc_start_tx(struct uart_port *port)
+{
+	unsigned long tx_fifo_imr;
+
+	tx_fifo_imr = in_be32(&FIFO_512x(port)->tximr);
+	tx_fifo_imr |= MPC512x_PSC_FIFO_ALARM;
+	out_be32(&FIFO_512x(port)->tximr, tx_fifo_imr);
+}
+
+static void mpc512x_psc_stop_tx(struct uart_port *port)
+{
+	unsigned long tx_fifo_imr;
+
+	tx_fifo_imr = in_be32(&FIFO_512x(port)->tximr);
+	tx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM;
+	out_be32(&FIFO_512x(port)->tximr, tx_fifo_imr);
+}
+
+static void mpc512x_psc_rx_clr_irq(struct uart_port *port)
+{
+	out_be32(&FIFO_512x(port)->rxisr, in_be32(&FIFO_512x(port)->rxisr));
+}
+
+static void mpc512x_psc_tx_clr_irq(struct uart_port *port)
+{
+	out_be32(&FIFO_512x(port)->txisr, in_be32(&FIFO_512x(port)->txisr));
+}
+
+static void mpc512x_psc_write_char(struct uart_port *port, unsigned char c)
+{
+	out_8(&FIFO_512x(port)->txdata_8, c);
+}
+
+static unsigned char mpc512x_psc_read_char(struct uart_port *port)
+{
+	return in_8(&FIFO_512x(port)->rxdata_8);
+}
+
+static void mpc512x_psc_cw_disable_ints(struct uart_port *port)
+{
+	port->read_status_mask =
+		in_be32(&FIFO_512x(port)->tximr) << 16 |
+		in_be32(&FIFO_512x(port)->rximr);
+	out_be32(&FIFO_512x(port)->tximr, 0);
+	out_be32(&FIFO_512x(port)->rximr, 0);
+}
+
+static void mpc512x_psc_cw_restore_ints(struct uart_port *port)
+{
+	out_be32(&FIFO_512x(port)->tximr,
+		(port->read_status_mask >> 16) & 0x7f);
+	out_be32(&FIFO_512x(port)->rximr, port->read_status_mask & 0x7f);
+}
+
+static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port,
+					     struct ktermios *new,
+					     const struct ktermios *old)
+{
+	unsigned int baud;
+	unsigned int divisor;
+
+	/*
+	 * The "MPC5121e Microcontroller Reference Manual, Rev. 3" says on
+	 * pg. 30-10 that the chip supports a /32 and a /10 prescaler.
+	 * Furthermore, it states that "After reset, the prescaler by 10
+	 * for the UART mode is selected", but the reset register value is
+	 * 0x0000 which means a /32 prescaler. This is wrong.
+	 *
+	 * In reality using /32 prescaler doesn't work, as it is not supported!
+	 * Use /16 or /10 prescaler, see "MPC5121e Hardware Design Guide",
+	 * Chapter 4.1 PSC in UART Mode.
+	 * Calculate with a /16 prescaler here.
+	 */
+
+	/* uartclk contains the ips freq */
+	baud = uart_get_baud_rate(port, new, old,
+				  port->uartclk / (16 * 0xffff) + 1,
+				  port->uartclk / 16);
+	divisor = (port->uartclk + 8 * baud) / (16 * baud);
+
+	/* enable the /16 prescaler and set the divisor */
+	mpc52xx_set_divisor(PSC(port), 0xdd00, divisor);
+	return baud;
+}
+
+/* Init PSC FIFO Controller */
+static int __init mpc512x_psc_fifoc_init(void)
+{
+	int err;
+	struct device_node *np;
+	struct clk *clk;
+
+	/* default error code, potentially overwritten by clock calls */
+	err = -ENODEV;
+
+	np = of_find_compatible_node(NULL, NULL,
+				     "fsl,mpc5121-psc-fifo");
+	if (!np) {
+		pr_err("%s: Can't find FIFOC node\n", __func__);
+		goto out_err;
+	}
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		/* backwards compat with device trees that lack clock specs */
+		clk = clk_get_sys(np->name, "ipg");
+	}
+	if (IS_ERR(clk)) {
+		pr_err("%s: Can't lookup FIFO clock\n", __func__);
+		err = PTR_ERR(clk);
+		goto out_ofnode_put;
+	}
+	if (clk_prepare_enable(clk)) {
+		pr_err("%s: Can't enable FIFO clock\n", __func__);
+		clk_put(clk);
+		goto out_ofnode_put;
+	}
+	psc_fifoc_clk = clk;
+
+	psc_fifoc = of_iomap(np, 0);
+	if (!psc_fifoc) {
+		pr_err("%s: Can't map FIFOC\n", __func__);
+		goto out_clk_disable;
+	}
+
+	psc_fifoc_irq = irq_of_parse_and_map(np, 0);
+	if (psc_fifoc_irq == 0) {
+		pr_err("%s: Can't get FIFOC irq\n", __func__);
+		goto out_unmap;
+	}
+
+	of_node_put(np);
+	return 0;
+
+out_unmap:
+	iounmap(psc_fifoc);
+out_clk_disable:
+	clk_disable_unprepare(psc_fifoc_clk);
+	clk_put(psc_fifoc_clk);
+out_ofnode_put:
+	of_node_put(np);
+out_err:
+	return err;
+}
+
+static void __exit mpc512x_psc_fifoc_uninit(void)
+{
+	iounmap(psc_fifoc);
+
+	/* disable the clock, errors are not fatal */
+	if (psc_fifoc_clk) {
+		clk_disable_unprepare(psc_fifoc_clk);
+		clk_put(psc_fifoc_clk);
+		psc_fifoc_clk = NULL;
+	}
+}
+
+/* 512x specific interrupt handler. The caller holds the port lock */
+static irqreturn_t mpc512x_psc_handle_irq(struct uart_port *port)
+{
+	unsigned long fifoc_int;
+	int psc_num;
+
+	/* Read pending PSC FIFOC interrupts */
+	fifoc_int = in_be32(&psc_fifoc->fifoc_int);
+
+	/* Check if it is an interrupt for this port */
+	psc_num = (port->mapbase & 0xf00) >> 8;
+	if (test_bit(psc_num, &fifoc_int) ||
+	    test_bit(psc_num + 16, &fifoc_int))
+		return mpc5xxx_uart_process_int(port);
+
+	return IRQ_NONE;
+}
+
+static struct clk *psc_mclk_clk[MPC52xx_PSC_MAXNUM];
+static struct clk *psc_ipg_clk[MPC52xx_PSC_MAXNUM];
+
+/* called from within the .request_port() callback (allocation) */
+static int mpc512x_psc_alloc_clock(struct uart_port *port)
+{
+	int psc_num;
+	struct clk *clk;
+	int err;
+
+	psc_num = (port->mapbase & 0xf00) >> 8;
+
+	clk = devm_clk_get(port->dev, "mclk");
+	if (IS_ERR(clk)) {
+		dev_err(port->dev, "Failed to get MCLK!\n");
+		err = PTR_ERR(clk);
+		goto out_err;
+	}
+	err = clk_prepare_enable(clk);
+	if (err) {
+		dev_err(port->dev, "Failed to enable MCLK!\n");
+		goto out_err;
+	}
+	psc_mclk_clk[psc_num] = clk;
+
+	clk = devm_clk_get(port->dev, "ipg");
+	if (IS_ERR(clk)) {
+		dev_err(port->dev, "Failed to get IPG clock!\n");
+		err = PTR_ERR(clk);
+		goto out_err;
+	}
+	err = clk_prepare_enable(clk);
+	if (err) {
+		dev_err(port->dev, "Failed to enable IPG clock!\n");
+		goto out_err;
+	}
+	psc_ipg_clk[psc_num] = clk;
+
+	return 0;
+
+out_err:
+	if (psc_mclk_clk[psc_num]) {
+		clk_disable_unprepare(psc_mclk_clk[psc_num]);
+		psc_mclk_clk[psc_num] = NULL;
+	}
+	if (psc_ipg_clk[psc_num]) {
+		clk_disable_unprepare(psc_ipg_clk[psc_num]);
+		psc_ipg_clk[psc_num] = NULL;
+	}
+	return err;
+}
+
+/* called from within the .release_port() callback (release) */
+static void mpc512x_psc_relse_clock(struct uart_port *port)
+{
+	int psc_num;
+	struct clk *clk;
+
+	psc_num = (port->mapbase & 0xf00) >> 8;
+	clk = psc_mclk_clk[psc_num];
+	if (clk) {
+		clk_disable_unprepare(clk);
+		psc_mclk_clk[psc_num] = NULL;
+	}
+	if (psc_ipg_clk[psc_num]) {
+		clk_disable_unprepare(psc_ipg_clk[psc_num]);
+		psc_ipg_clk[psc_num] = NULL;
+	}
+}
+
+/* implementation of the .clock() callback (enable/disable) */
+static int mpc512x_psc_endis_clock(struct uart_port *port, int enable)
+{
+	int psc_num;
+	struct clk *psc_clk;
+	int ret;
+
+	if (uart_console(port))
+		return 0;
+
+	psc_num = (port->mapbase & 0xf00) >> 8;
+	psc_clk = psc_mclk_clk[psc_num];
+	if (!psc_clk) {
+		dev_err(port->dev, "Failed to get PSC clock entry!\n");
+		return -ENODEV;
+	}
+
+	dev_dbg(port->dev, "mclk %sable\n", enable ? "en" : "dis");
+	if (enable) {
+		ret = clk_enable(psc_clk);
+		if (ret)
+			dev_err(port->dev, "Failed to enable MCLK!\n");
+		return ret;
+	} else {
+		clk_disable(psc_clk);
+		return 0;
+	}
+}
+
+static void mpc512x_psc_get_irq(struct uart_port *port, struct device_node *np)
+{
+	port->irqflags = IRQF_SHARED;
+	port->irq = psc_fifoc_irq;
+}
+
+#define PSC_5125(port) ((struct mpc5125_psc __iomem *)((port)->membase))
+#define FIFO_5125(port) ((struct mpc512x_psc_fifo __iomem *)(PSC_5125(port)+1))
+
+static void mpc5125_psc_fifo_init(struct uart_port *port)
+{
+	/* /32 prescaler */
+	out_8(&PSC_5125(port)->mpc52xx_psc_clock_select, 0xdd);
+
+	out_be32(&FIFO_5125(port)->txcmd, MPC512x_PSC_FIFO_RESET_SLICE);
+	out_be32(&FIFO_5125(port)->txcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
+	out_be32(&FIFO_5125(port)->txalarm, 1);
+	out_be32(&FIFO_5125(port)->tximr, 0);
+
+	out_be32(&FIFO_5125(port)->rxcmd, MPC512x_PSC_FIFO_RESET_SLICE);
+	out_be32(&FIFO_5125(port)->rxcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
+	out_be32(&FIFO_5125(port)->rxalarm, 1);
+	out_be32(&FIFO_5125(port)->rximr, 0);
+
+	out_be32(&FIFO_5125(port)->tximr, MPC512x_PSC_FIFO_ALARM);
+	out_be32(&FIFO_5125(port)->rximr, MPC512x_PSC_FIFO_ALARM);
+}
+
+static unsigned int mpc5125_psc_raw_rx_rdy(struct uart_port *port)
+{
+	return !(in_be32(&FIFO_5125(port)->rxsr) & MPC512x_PSC_FIFO_EMPTY);
+}
+
+static unsigned int mpc5125_psc_raw_tx_rdy(struct uart_port *port)
+{
+	return !(in_be32(&FIFO_5125(port)->txsr) & MPC512x_PSC_FIFO_FULL);
+}
+
+static unsigned int mpc5125_psc_rx_rdy(struct uart_port *port)
+{
+	return in_be32(&FIFO_5125(port)->rxsr) &
+	       in_be32(&FIFO_5125(port)->rximr) & MPC512x_PSC_FIFO_ALARM;
+}
+
+static unsigned int mpc5125_psc_tx_rdy(struct uart_port *port)
+{
+	return in_be32(&FIFO_5125(port)->txsr) &
+	       in_be32(&FIFO_5125(port)->tximr) & MPC512x_PSC_FIFO_ALARM;
+}
+
+static unsigned int mpc5125_psc_tx_empty(struct uart_port *port)
+{
+	return in_be32(&FIFO_5125(port)->txsr) & MPC512x_PSC_FIFO_EMPTY;
+}
+
+static void mpc5125_psc_stop_rx(struct uart_port *port)
+{
+	unsigned long rx_fifo_imr;
+
+	rx_fifo_imr = in_be32(&FIFO_5125(port)->rximr);
+	rx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM;
+	out_be32(&FIFO_5125(port)->rximr, rx_fifo_imr);
+}
+
+static void mpc5125_psc_start_tx(struct uart_port *port)
+{
+	unsigned long tx_fifo_imr;
+
+	tx_fifo_imr = in_be32(&FIFO_5125(port)->tximr);
+	tx_fifo_imr |= MPC512x_PSC_FIFO_ALARM;
+	out_be32(&FIFO_5125(port)->tximr, tx_fifo_imr);
+}
+
+static void mpc5125_psc_stop_tx(struct uart_port *port)
+{
+	unsigned long tx_fifo_imr;
+
+	tx_fifo_imr = in_be32(&FIFO_5125(port)->tximr);
+	tx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM;
+	out_be32(&FIFO_5125(port)->tximr, tx_fifo_imr);
+}
+
+static void mpc5125_psc_rx_clr_irq(struct uart_port *port)
+{
+	out_be32(&FIFO_5125(port)->rxisr, in_be32(&FIFO_5125(port)->rxisr));
+}
+
+static void mpc5125_psc_tx_clr_irq(struct uart_port *port)
+{
+	out_be32(&FIFO_5125(port)->txisr, in_be32(&FIFO_5125(port)->txisr));
+}
+
+static void mpc5125_psc_write_char(struct uart_port *port, unsigned char c)
+{
+	out_8(&FIFO_5125(port)->txdata_8, c);
+}
+
+static unsigned char mpc5125_psc_read_char(struct uart_port *port)
+{
+	return in_8(&FIFO_5125(port)->rxdata_8);
+}
+
+static void mpc5125_psc_cw_disable_ints(struct uart_port *port)
+{
+	port->read_status_mask =
+		in_be32(&FIFO_5125(port)->tximr) << 16 |
+		in_be32(&FIFO_5125(port)->rximr);
+	out_be32(&FIFO_5125(port)->tximr, 0);
+	out_be32(&FIFO_5125(port)->rximr, 0);
+}
+
+static void mpc5125_psc_cw_restore_ints(struct uart_port *port)
+{
+	out_be32(&FIFO_5125(port)->tximr,
+		(port->read_status_mask >> 16) & 0x7f);
+	out_be32(&FIFO_5125(port)->rximr, port->read_status_mask & 0x7f);
+}
+
+static inline void mpc5125_set_divisor(struct mpc5125_psc __iomem *psc,
+		u8 prescaler, unsigned int divisor)
+{
+	/* select prescaler */
+	out_8(&psc->mpc52xx_psc_clock_select, prescaler);
+	out_8(&psc->ctur, divisor >> 8);
+	out_8(&psc->ctlr, divisor & 0xff);
+}
+
+static unsigned int mpc5125_psc_set_baudrate(struct uart_port *port,
+					     struct ktermios *new,
+					     const struct ktermios *old)
+{
+	unsigned int baud;
+	unsigned int divisor;
+
+	/*
+	 * Calculate with a /16 prescaler here.
+	 */
+
+	/* uartclk contains the ips freq */
+	baud = uart_get_baud_rate(port, new, old,
+				  port->uartclk / (16 * 0xffff) + 1,
+				  port->uartclk / 16);
+	divisor = (port->uartclk + 8 * baud) / (16 * baud);
+
+	/* enable the /16 prescaler and set the divisor */
+	mpc5125_set_divisor(PSC_5125(port), 0xdd, divisor);
+	return baud;
+}
+
+/*
+ * MPC5125 have compatible PSC FIFO Controller.
+ * Special init not needed.
+ */
+static u16 mpc5125_psc_get_status(struct uart_port *port)
+{
+	return in_be16(&PSC_5125(port)->mpc52xx_psc_status);
+}
+
+static u8 mpc5125_psc_get_ipcr(struct uart_port *port)
+{
+	return in_8(&PSC_5125(port)->mpc52xx_psc_ipcr);
+}
+
+static void mpc5125_psc_command(struct uart_port *port, u8 cmd)
+{
+	out_8(&PSC_5125(port)->command, cmd);
+}
+
+static void mpc5125_psc_set_mode(struct uart_port *port, u8 mr1, u8 mr2)
+{
+	out_8(&PSC_5125(port)->mr1, mr1);
+	out_8(&PSC_5125(port)->mr2, mr2);
+}
+
+static void mpc5125_psc_set_rts(struct uart_port *port, int state)
+{
+	if (state & TIOCM_RTS)
+		out_8(&PSC_5125(port)->op1, MPC52xx_PSC_OP_RTS);
+	else
+		out_8(&PSC_5125(port)->op0, MPC52xx_PSC_OP_RTS);
+}
+
+static void mpc5125_psc_enable_ms(struct uart_port *port)
+{
+	struct mpc5125_psc __iomem *psc = PSC_5125(port);
+
+	/* clear D_*-bits by reading them */
+	in_8(&psc->mpc52xx_psc_ipcr);
+	/* enable CTS and DCD as IPC interrupts */
+	out_8(&psc->mpc52xx_psc_acr, MPC52xx_PSC_IEC_CTS | MPC52xx_PSC_IEC_DCD);
+
+	port->read_status_mask |= MPC52xx_PSC_IMR_IPC;
+	out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
+}
+
+static void mpc5125_psc_set_sicr(struct uart_port *port, u32 val)
+{
+	out_be32(&PSC_5125(port)->sicr, val);
+}
+
+static void mpc5125_psc_set_imr(struct uart_port *port, u16 val)
+{
+	out_be16(&PSC_5125(port)->mpc52xx_psc_imr, val);
+}
+
+static u8 mpc5125_psc_get_mr1(struct uart_port *port)
+{
+	return in_8(&PSC_5125(port)->mr1);
+}
+
+static const struct psc_ops mpc5125_psc_ops = {
+	.fifo_init = mpc5125_psc_fifo_init,
+	.raw_rx_rdy = mpc5125_psc_raw_rx_rdy,
+	.raw_tx_rdy = mpc5125_psc_raw_tx_rdy,
+	.rx_rdy = mpc5125_psc_rx_rdy,
+	.tx_rdy = mpc5125_psc_tx_rdy,
+	.tx_empty = mpc5125_psc_tx_empty,
+	.stop_rx = mpc5125_psc_stop_rx,
+	.start_tx = mpc5125_psc_start_tx,
+	.stop_tx = mpc5125_psc_stop_tx,
+	.rx_clr_irq = mpc5125_psc_rx_clr_irq,
+	.tx_clr_irq = mpc5125_psc_tx_clr_irq,
+	.write_char = mpc5125_psc_write_char,
+	.read_char = mpc5125_psc_read_char,
+	.cw_disable_ints = mpc5125_psc_cw_disable_ints,
+	.cw_restore_ints = mpc5125_psc_cw_restore_ints,
+	.set_baudrate = mpc5125_psc_set_baudrate,
+	.clock_alloc = mpc512x_psc_alloc_clock,
+	.clock_relse = mpc512x_psc_relse_clock,
+	.clock = mpc512x_psc_endis_clock,
+	.fifoc_init = mpc512x_psc_fifoc_init,
+	.fifoc_uninit = mpc512x_psc_fifoc_uninit,
+	.get_irq = mpc512x_psc_get_irq,
+	.handle_irq = mpc512x_psc_handle_irq,
+	.get_status = mpc5125_psc_get_status,
+	.get_ipcr = mpc5125_psc_get_ipcr,
+	.command = mpc5125_psc_command,
+	.set_mode = mpc5125_psc_set_mode,
+	.set_rts = mpc5125_psc_set_rts,
+	.enable_ms = mpc5125_psc_enable_ms,
+	.set_sicr = mpc5125_psc_set_sicr,
+	.set_imr = mpc5125_psc_set_imr,
+	.get_mr1 = mpc5125_psc_get_mr1,
+};
+
+static const struct psc_ops mpc512x_psc_ops = {
+	.fifo_init = mpc512x_psc_fifo_init,
+	.raw_rx_rdy = mpc512x_psc_raw_rx_rdy,
+	.raw_tx_rdy = mpc512x_psc_raw_tx_rdy,
+	.rx_rdy = mpc512x_psc_rx_rdy,
+	.tx_rdy = mpc512x_psc_tx_rdy,
+	.tx_empty = mpc512x_psc_tx_empty,
+	.stop_rx = mpc512x_psc_stop_rx,
+	.start_tx = mpc512x_psc_start_tx,
+	.stop_tx = mpc512x_psc_stop_tx,
+	.rx_clr_irq = mpc512x_psc_rx_clr_irq,
+	.tx_clr_irq = mpc512x_psc_tx_clr_irq,
+	.write_char = mpc512x_psc_write_char,
+	.read_char = mpc512x_psc_read_char,
+	.cw_disable_ints = mpc512x_psc_cw_disable_ints,
+	.cw_restore_ints = mpc512x_psc_cw_restore_ints,
+	.set_baudrate = mpc512x_psc_set_baudrate,
+	.clock_alloc = mpc512x_psc_alloc_clock,
+	.clock_relse = mpc512x_psc_relse_clock,
+	.clock = mpc512x_psc_endis_clock,
+	.fifoc_init = mpc512x_psc_fifoc_init,
+	.fifoc_uninit = mpc512x_psc_fifoc_uninit,
+	.get_irq = mpc512x_psc_get_irq,
+	.handle_irq = mpc512x_psc_handle_irq,
+	.get_status = mpc52xx_psc_get_status,
+	.get_ipcr = mpc52xx_psc_get_ipcr,
+	.command = mpc52xx_psc_command,
+	.set_mode = mpc52xx_psc_set_mode,
+	.set_rts = mpc52xx_psc_set_rts,
+	.enable_ms = mpc52xx_psc_enable_ms,
+	.set_sicr = mpc52xx_psc_set_sicr,
+	.set_imr = mpc52xx_psc_set_imr,
+	.get_mr1 = mpc52xx_psc_get_mr1,
+};
+#endif /* CONFIG_PPC_MPC512x */
+
+
+static const struct psc_ops *psc_ops;
+
+/* ======================================================================== */
+/* UART operations                                                          */
+/* ======================================================================== */
+
+static unsigned int
+mpc52xx_uart_tx_empty(struct uart_port *port)
+{
+	return psc_ops->tx_empty(port) ? TIOCSER_TEMT : 0;
+}
+
+static void
+mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	psc_ops->set_rts(port, mctrl & TIOCM_RTS);
+}
+
+static unsigned int
+mpc52xx_uart_get_mctrl(struct uart_port *port)
+{
+	unsigned int ret = TIOCM_DSR;
+	u8 status = psc_ops->get_ipcr(port);
+
+	if (!(status & MPC52xx_PSC_CTS))
+		ret |= TIOCM_CTS;
+	if (!(status & MPC52xx_PSC_DCD))
+		ret |= TIOCM_CAR;
+
+	return ret;
+}
+
+static void
+mpc52xx_uart_stop_tx(struct uart_port *port)
+{
+	/* port->lock taken by caller */
+	psc_ops->stop_tx(port);
+}
+
+static void
+mpc52xx_uart_start_tx(struct uart_port *port)
+{
+	/* port->lock taken by caller */
+	psc_ops->start_tx(port);
+}
+
+static void
+mpc52xx_uart_stop_rx(struct uart_port *port)
+{
+	/* port->lock taken by caller */
+	psc_ops->stop_rx(port);
+}
+
+static void
+mpc52xx_uart_enable_ms(struct uart_port *port)
+{
+	psc_ops->enable_ms(port);
+}
+
+static void
+mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (ctl == -1)
+		psc_ops->command(port, MPC52xx_PSC_START_BRK);
+	else
+		psc_ops->command(port, MPC52xx_PSC_STOP_BRK);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int
+mpc52xx_uart_startup(struct uart_port *port)
+{
+	int ret;
+
+	if (psc_ops->clock) {
+		ret = psc_ops->clock(port, 1);
+		if (ret)
+			return ret;
+	}
+
+	/* Request IRQ */
+	ret = request_irq(port->irq, mpc52xx_uart_int,
+			  port->irqflags, "mpc52xx_psc_uart", port);
+	if (ret)
+		return ret;
+
+	/* Reset/activate the port, clear and enable interrupts */
+	psc_ops->command(port, MPC52xx_PSC_RST_RX);
+	psc_ops->command(port, MPC52xx_PSC_RST_TX);
+
+	/*
+	 * According to Freescale's support the RST_TX command can produce a
+	 * spike on the TX pin. So they recommend to delay "for one character".
+	 * One millisecond should be enough for everyone.
+	 */
+	msleep(1);
+
+	psc_ops->set_sicr(port, 0);	/* UART mode DCD ignored */
+
+	psc_ops->fifo_init(port);
+
+	psc_ops->command(port, MPC52xx_PSC_TX_ENABLE);
+	psc_ops->command(port, MPC52xx_PSC_RX_ENABLE);
+
+	return 0;
+}
+
+static void
+mpc52xx_uart_shutdown(struct uart_port *port)
+{
+	/* Shut down the port.  Leave TX active if on a console port */
+	psc_ops->command(port, MPC52xx_PSC_RST_RX);
+	if (!uart_console(port))
+		psc_ops->command(port, MPC52xx_PSC_RST_TX);
+
+	port->read_status_mask = 0;
+	psc_ops->set_imr(port, port->read_status_mask);
+
+	if (psc_ops->clock)
+		psc_ops->clock(port, 0);
+
+	/* Disable interrupt */
+	psc_ops->cw_disable_ints(port);
+
+	/* Release interrupt */
+	free_irq(port->irq, port);
+}
+
+static void
+mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
+			 const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned char mr1, mr2;
+	unsigned int j;
+	unsigned int baud;
+
+	/* Prepare what we're gonna write */
+	mr1 = 0;
+
+	switch (new->c_cflag & CSIZE) {
+	case CS5:	mr1 |= MPC52xx_PSC_MODE_5_BITS;
+		break;
+	case CS6:	mr1 |= MPC52xx_PSC_MODE_6_BITS;
+		break;
+	case CS7:	mr1 |= MPC52xx_PSC_MODE_7_BITS;
+		break;
+	case CS8:
+	default:	mr1 |= MPC52xx_PSC_MODE_8_BITS;
+	}
+
+	if (new->c_cflag & PARENB) {
+		if (new->c_cflag & CMSPAR)
+			mr1 |= MPC52xx_PSC_MODE_PARFORCE;
+
+		/* With CMSPAR, PARODD also means high parity (same as termios) */
+		mr1 |= (new->c_cflag & PARODD) ?
+			MPC52xx_PSC_MODE_PARODD : MPC52xx_PSC_MODE_PAREVEN;
+	} else {
+		mr1 |= MPC52xx_PSC_MODE_PARNONE;
+	}
+
+	mr2 = 0;
+
+	if (new->c_cflag & CSTOPB)
+		mr2 |= MPC52xx_PSC_MODE_TWO_STOP;
+	else
+		mr2 |= ((new->c_cflag & CSIZE) == CS5) ?
+			MPC52xx_PSC_MODE_ONE_STOP_5_BITS :
+			MPC52xx_PSC_MODE_ONE_STOP;
+
+	if (new->c_cflag & CRTSCTS) {
+		mr1 |= MPC52xx_PSC_MODE_RXRTS;
+		mr2 |= MPC52xx_PSC_MODE_TXCTS;
+	}
+
+	/* Get the lock */
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Do our best to flush TX & RX, so we don't lose anything */
+	/* But we don't wait indefinitely ! */
+	j = 5000000;	/* Maximum wait */
+	/* FIXME Can't receive chars since set_termios might be called at early
+	 * boot for the console, all stuff is not yet ready to receive at that
+	 * time and that just makes the kernel oops */
+	/* while (j-- && mpc52xx_uart_int_rx_chars(port)); */
+	while (!mpc52xx_uart_tx_empty(port) && --j)
+		udelay(1);
+
+	if (!j)
+		printk(KERN_ERR "mpc52xx_uart.c: "
+			"Unable to flush RX & TX fifos in-time in set_termios."
+			"Some chars may have been lost.\n");
+
+	/* Reset the TX & RX */
+	psc_ops->command(port, MPC52xx_PSC_RST_RX);
+	psc_ops->command(port, MPC52xx_PSC_RST_TX);
+
+	/* Send new mode settings */
+	psc_ops->set_mode(port, mr1, mr2);
+	baud = psc_ops->set_baudrate(port, new, old);
+
+	/* Update the per-port timeout */
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	if (UART_ENABLE_MS(port, new->c_cflag))
+		mpc52xx_uart_enable_ms(port);
+
+	/* Reenable TX & RX */
+	psc_ops->command(port, MPC52xx_PSC_TX_ENABLE);
+	psc_ops->command(port, MPC52xx_PSC_RX_ENABLE);
+
+	/* We're all set, release the lock */
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *
+mpc52xx_uart_type(struct uart_port *port)
+{
+	/*
+	 * We keep using PORT_MPC52xx for historic reasons although it applies
+	 * for MPC512x, too, but print "MPC5xxx" to not irritate users
+	 */
+	return port->type == PORT_MPC52xx ? "MPC5xxx PSC" : NULL;
+}
+
+static void
+mpc52xx_uart_release_port(struct uart_port *port)
+{
+	if (psc_ops->clock_relse)
+		psc_ops->clock_relse(port);
+
+	/* remapped by us ? */
+	if (port->flags & UPF_IOREMAP) {
+		iounmap(port->membase);
+		port->membase = NULL;
+	}
+
+	release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc));
+}
+
+static int
+mpc52xx_uart_request_port(struct uart_port *port)
+{
+	int err;
+
+	if (port->flags & UPF_IOREMAP) /* Need to remap ? */
+		port->membase = ioremap(port->mapbase,
+					sizeof(struct mpc52xx_psc));
+
+	if (!port->membase)
+		return -EINVAL;
+
+	err = request_mem_region(port->mapbase, sizeof(struct mpc52xx_psc),
+			"mpc52xx_psc_uart") != NULL ? 0 : -EBUSY;
+
+	if (err)
+		goto out_membase;
+
+	if (psc_ops->clock_alloc) {
+		err = psc_ops->clock_alloc(port);
+		if (err)
+			goto out_mapregion;
+	}
+
+	return 0;
+
+out_mapregion:
+	release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc));
+out_membase:
+	if (port->flags & UPF_IOREMAP) {
+		iounmap(port->membase);
+		port->membase = NULL;
+	}
+	return err;
+}
+
+static void
+mpc52xx_uart_config_port(struct uart_port *port, int flags)
+{
+	if ((flags & UART_CONFIG_TYPE)
+		&& (mpc52xx_uart_request_port(port) == 0))
+		port->type = PORT_MPC52xx;
+}
+
+static int
+mpc52xx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_MPC52xx)
+		return -EINVAL;
+
+	if ((ser->irq != port->irq) ||
+	    (ser->io_type != UPIO_MEM) ||
+	    (ser->baud_base != port->uartclk)  ||
+	    (ser->iomem_base != (void *)port->mapbase) ||
+	    (ser->hub6 != 0))
+		return -EINVAL;
+
+	return 0;
+}
+
+
+static const struct uart_ops mpc52xx_uart_ops = {
+	.tx_empty	= mpc52xx_uart_tx_empty,
+	.set_mctrl	= mpc52xx_uart_set_mctrl,
+	.get_mctrl	= mpc52xx_uart_get_mctrl,
+	.stop_tx	= mpc52xx_uart_stop_tx,
+	.start_tx	= mpc52xx_uart_start_tx,
+	.stop_rx	= mpc52xx_uart_stop_rx,
+	.enable_ms	= mpc52xx_uart_enable_ms,
+	.break_ctl	= mpc52xx_uart_break_ctl,
+	.startup	= mpc52xx_uart_startup,
+	.shutdown	= mpc52xx_uart_shutdown,
+	.set_termios	= mpc52xx_uart_set_termios,
+/*	.pm		= mpc52xx_uart_pm,		Not supported yet */
+	.type		= mpc52xx_uart_type,
+	.release_port	= mpc52xx_uart_release_port,
+	.request_port	= mpc52xx_uart_request_port,
+	.config_port	= mpc52xx_uart_config_port,
+	.verify_port	= mpc52xx_uart_verify_port
+};
+
+
+/* ======================================================================== */
+/* Interrupt handling                                                       */
+/* ======================================================================== */
+
+static inline bool
+mpc52xx_uart_int_rx_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned char ch, flag;
+	unsigned short status;
+
+	/* While we can read, do so ! */
+	while (psc_ops->raw_rx_rdy(port)) {
+		/* Get the char */
+		ch = psc_ops->read_char(port);
+
+		/* Handle sysreq char */
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		/* Store it */
+
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		status = psc_ops->get_status(port);
+
+		if (status & (MPC52xx_PSC_SR_PE |
+			      MPC52xx_PSC_SR_FE |
+			      MPC52xx_PSC_SR_RB)) {
+
+			if (status & MPC52xx_PSC_SR_RB) {
+				flag = TTY_BREAK;
+				uart_handle_break(port);
+				port->icount.brk++;
+			} else if (status & MPC52xx_PSC_SR_PE) {
+				flag = TTY_PARITY;
+				port->icount.parity++;
+			}
+			else if (status & MPC52xx_PSC_SR_FE) {
+				flag = TTY_FRAME;
+				port->icount.frame++;
+			}
+
+			/* Clear error condition */
+			psc_ops->command(port, MPC52xx_PSC_RST_ERR_STAT);
+
+		}
+		tty_insert_flip_char(tport, ch, flag);
+		if (status & MPC52xx_PSC_SR_OE) {
+			/*
+			 * Overrun is special, since it's
+			 * reported immediately, and doesn't
+			 * affect the current character
+			 */
+			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+			port->icount.overrun++;
+		}
+	}
+
+	tty_flip_buffer_push(tport);
+
+	return psc_ops->raw_rx_rdy(port);
+}
+
+static inline bool
+mpc52xx_uart_int_tx_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	return uart_port_tx(port, ch,
+		psc_ops->raw_tx_rdy(port),
+		psc_ops->write_char(port, ch));
+}
+
+static irqreturn_t
+mpc5xxx_uart_process_int(struct uart_port *port)
+{
+	unsigned long pass = ISR_PASS_LIMIT;
+	bool keepgoing;
+	u8 status;
+
+	/* While we have stuff to do, we continue */
+	do {
+		/* If we don't find anything to do, we stop */
+		keepgoing = false;
+
+		psc_ops->rx_clr_irq(port);
+		if (psc_ops->rx_rdy(port))
+			keepgoing |= mpc52xx_uart_int_rx_chars(port);
+
+		psc_ops->tx_clr_irq(port);
+		if (psc_ops->tx_rdy(port))
+			keepgoing |= mpc52xx_uart_int_tx_chars(port);
+
+		status = psc_ops->get_ipcr(port);
+		if (status & MPC52xx_PSC_D_DCD)
+			uart_handle_dcd_change(port, !(status & MPC52xx_PSC_DCD));
+
+		if (status & MPC52xx_PSC_D_CTS)
+			uart_handle_cts_change(port, !(status & MPC52xx_PSC_CTS));
+
+		/* Limit number of iteration */
+		if (!(--pass))
+			keepgoing = false;
+
+	} while (keepgoing);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t
+mpc52xx_uart_int(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	irqreturn_t ret;
+
+	spin_lock(&port->lock);
+
+	ret = psc_ops->handle_irq(port);
+
+	spin_unlock(&port->lock);
+
+	return ret;
+}
+
+/* ======================================================================== */
+/* Console ( if applicable )                                                */
+/* ======================================================================== */
+
+#ifdef CONFIG_SERIAL_MPC52xx_CONSOLE
+
+static void __init
+mpc52xx_console_get_options(struct uart_port *port,
+			    int *baud, int *parity, int *bits, int *flow)
+{
+	unsigned char mr1;
+
+	pr_debug("mpc52xx_console_get_options(port=%p)\n", port);
+
+	/* Read the mode registers */
+	mr1 = psc_ops->get_mr1(port);
+
+	/* CT{U,L}R are write-only ! */
+	*baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
+
+	/* Parse them */
+	switch (mr1 & MPC52xx_PSC_MODE_BITS_MASK) {
+	case MPC52xx_PSC_MODE_5_BITS:
+		*bits = 5;
+		break;
+	case MPC52xx_PSC_MODE_6_BITS:
+		*bits = 6;
+		break;
+	case MPC52xx_PSC_MODE_7_BITS:
+		*bits = 7;
+		break;
+	case MPC52xx_PSC_MODE_8_BITS:
+	default:
+		*bits = 8;
+	}
+
+	if (mr1 & MPC52xx_PSC_MODE_PARNONE)
+		*parity = 'n';
+	else
+		*parity = mr1 & MPC52xx_PSC_MODE_PARODD ? 'o' : 'e';
+}
+
+static void
+mpc52xx_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_port *port = &mpc52xx_uart_ports[co->index];
+	unsigned int i, j;
+
+	/* Disable interrupts */
+	psc_ops->cw_disable_ints(port);
+
+	/* Wait the TX buffer to be empty */
+	j = 5000000;	/* Maximum wait */
+	while (!mpc52xx_uart_tx_empty(port) && --j)
+		udelay(1);
+
+	/* Write all the chars */
+	for (i = 0; i < count; i++, s++) {
+		/* Line return handling */
+		if (*s == '\n')
+			psc_ops->write_char(port, '\r');
+
+		/* Send the char */
+		psc_ops->write_char(port, *s);
+
+		/* Wait the TX buffer to be empty */
+		j = 20000;	/* Maximum wait */
+		while (!mpc52xx_uart_tx_empty(port) && --j)
+			udelay(1);
+	}
+
+	/* Restore interrupt state */
+	psc_ops->cw_restore_ints(port);
+}
+
+
+static int __init
+mpc52xx_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port = &mpc52xx_uart_ports[co->index];
+	struct device_node *np = mpc52xx_uart_nodes[co->index];
+	unsigned int uartclk;
+	struct resource res;
+	int ret;
+
+	int baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	pr_debug("mpc52xx_console_setup co=%p, co->index=%i, options=%s\n",
+		 co, co->index, options);
+
+	if ((co->index < 0) || (co->index >= MPC52xx_PSC_MAXNUM)) {
+		pr_debug("PSC%x out of range\n", co->index);
+		return -EINVAL;
+	}
+
+	if (!np) {
+		pr_debug("PSC%x not found in device tree\n", co->index);
+		return -EINVAL;
+	}
+
+	pr_debug("Console on ttyPSC%x is %pOF\n",
+		 co->index, mpc52xx_uart_nodes[co->index]);
+
+	/* Fetch register locations */
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		pr_debug("Could not get resources for PSC%x\n", co->index);
+		return ret;
+	}
+
+	uartclk = mpc5xxx_fwnode_get_bus_frequency(of_fwnode_handle(np));
+	if (uartclk == 0) {
+		pr_debug("Could not find uart clock frequency!\n");
+		return -EINVAL;
+	}
+
+	/* Basic port init. Needed since we use some uart_??? func before
+	 * real init for early access */
+	spin_lock_init(&port->lock);
+	port->uartclk = uartclk;
+	port->ops	= &mpc52xx_uart_ops;
+	port->mapbase = res.start;
+	port->membase = ioremap(res.start, sizeof(struct mpc52xx_psc));
+	port->irq = irq_of_parse_and_map(np, 0);
+
+	if (port->membase == NULL)
+		return -EINVAL;
+
+	pr_debug("mpc52xx-psc uart at %p, mapped to %p, irq=%x, freq=%i\n",
+		 (void *)port->mapbase, port->membase,
+		 port->irq, port->uartclk);
+
+	/* Setup the port parameters accoding to options */
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		mpc52xx_console_get_options(port, &baud, &parity, &bits, &flow);
+
+	pr_debug("Setting console parameters: %i %i%c1 flow=%c\n",
+		 baud, bits, parity, flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+
+static struct uart_driver mpc52xx_uart_driver;
+
+static struct console mpc52xx_console = {
+	.name	= "ttyPSC",
+	.write	= mpc52xx_console_write,
+	.device	= uart_console_device,
+	.setup	= mpc52xx_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,	/* Specified on the cmdline (e.g. console=ttyPSC0) */
+	.data	= &mpc52xx_uart_driver,
+};
+
+
+static int __init
+mpc52xx_console_init(void)
+{
+	mpc52xx_uart_of_enumerate();
+	register_console(&mpc52xx_console);
+	return 0;
+}
+
+console_initcall(mpc52xx_console_init);
+
+#define MPC52xx_PSC_CONSOLE &mpc52xx_console
+#else
+#define MPC52xx_PSC_CONSOLE NULL
+#endif
+
+
+/* ======================================================================== */
+/* UART Driver                                                              */
+/* ======================================================================== */
+
+static struct uart_driver mpc52xx_uart_driver = {
+	.driver_name	= "mpc52xx_psc_uart",
+	.dev_name	= "ttyPSC",
+	.major		= SERIAL_PSC_MAJOR,
+	.minor		= SERIAL_PSC_MINOR,
+	.nr		= MPC52xx_PSC_MAXNUM,
+	.cons		= MPC52xx_PSC_CONSOLE,
+};
+
+/* ======================================================================== */
+/* OF Platform Driver                                                       */
+/* ======================================================================== */
+
+static const struct of_device_id mpc52xx_uart_of_match[] = {
+#ifdef CONFIG_PPC_MPC52xx
+	{ .compatible = "fsl,mpc5200b-psc-uart", .data = &mpc5200b_psc_ops, },
+	{ .compatible = "fsl,mpc5200-psc-uart", .data = &mpc52xx_psc_ops, },
+	/* binding used by old lite5200 device trees: */
+	{ .compatible = "mpc5200-psc-uart", .data = &mpc52xx_psc_ops, },
+	/* binding used by efika: */
+	{ .compatible = "mpc5200-serial", .data = &mpc52xx_psc_ops, },
+#endif
+#ifdef CONFIG_PPC_MPC512x
+	{ .compatible = "fsl,mpc5121-psc-uart", .data = &mpc512x_psc_ops, },
+	{ .compatible = "fsl,mpc5125-psc-uart", .data = &mpc5125_psc_ops, },
+#endif
+	{},
+};
+
+static int mpc52xx_uart_of_probe(struct platform_device *op)
+{
+	int idx = -1;
+	unsigned int uartclk;
+	struct uart_port *port = NULL;
+	struct resource res;
+	int ret;
+
+	/* Check validity & presence */
+	for (idx = 0; idx < MPC52xx_PSC_MAXNUM; idx++)
+		if (mpc52xx_uart_nodes[idx] == op->dev.of_node)
+			break;
+	if (idx >= MPC52xx_PSC_MAXNUM)
+		return -EINVAL;
+	pr_debug("Found %pOF assigned to ttyPSC%x\n",
+		 mpc52xx_uart_nodes[idx], idx);
+
+	/* set the uart clock to the input clock of the psc, the different
+	 * prescalers are taken into account in the set_baudrate() methods
+	 * of the respective chip */
+	uartclk = mpc5xxx_get_bus_frequency(&op->dev);
+	if (uartclk == 0) {
+		dev_dbg(&op->dev, "Could not find uart clock frequency!\n");
+		return -EINVAL;
+	}
+
+	/* Init the port structure */
+	port = &mpc52xx_uart_ports[idx];
+
+	spin_lock_init(&port->lock);
+	port->uartclk = uartclk;
+	port->fifosize	= 512;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MPC52xx_CONSOLE);
+	port->iotype	= UPIO_MEM;
+	port->flags	= UPF_BOOT_AUTOCONF |
+			  (uart_console(port) ? 0 : UPF_IOREMAP);
+	port->line	= idx;
+	port->ops	= &mpc52xx_uart_ops;
+	port->dev	= &op->dev;
+
+	/* Search for IRQ and mapbase */
+	ret = of_address_to_resource(op->dev.of_node, 0, &res);
+	if (ret)
+		return ret;
+
+	port->mapbase = res.start;
+	if (!port->mapbase) {
+		dev_dbg(&op->dev, "Could not allocate resources for PSC\n");
+		return -EINVAL;
+	}
+
+	psc_ops->get_irq(port, op->dev.of_node);
+	if (port->irq == 0) {
+		dev_dbg(&op->dev, "Could not get irq\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(&op->dev, "mpc52xx-psc uart at %p, irq=%x, freq=%i\n",
+		(void *)port->mapbase, port->irq, port->uartclk);
+
+	/* Add the port to the uart sub-system */
+	ret = uart_add_one_port(&mpc52xx_uart_driver, port);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(op, (void *)port);
+	return 0;
+}
+
+static int
+mpc52xx_uart_of_remove(struct platform_device *op)
+{
+	struct uart_port *port = platform_get_drvdata(op);
+
+	if (port)
+		uart_remove_one_port(&mpc52xx_uart_driver, port);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int
+mpc52xx_uart_of_suspend(struct platform_device *op, pm_message_t state)
+{
+	struct uart_port *port = platform_get_drvdata(op);
+
+	if (port)
+		uart_suspend_port(&mpc52xx_uart_driver, port);
+
+	return 0;
+}
+
+static int
+mpc52xx_uart_of_resume(struct platform_device *op)
+{
+	struct uart_port *port = platform_get_drvdata(op);
+
+	if (port)
+		uart_resume_port(&mpc52xx_uart_driver, port);
+
+	return 0;
+}
+#endif
+
+static void
+mpc52xx_uart_of_assign(struct device_node *np)
+{
+	int i;
+
+	/* Find the first free PSC number */
+	for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) {
+		if (mpc52xx_uart_nodes[i] == NULL) {
+			of_node_get(np);
+			mpc52xx_uart_nodes[i] = np;
+			return;
+		}
+	}
+}
+
+static void
+mpc52xx_uart_of_enumerate(void)
+{
+	static int enum_done;
+	struct device_node *np;
+	const struct  of_device_id *match;
+	int i;
+
+	if (enum_done)
+		return;
+
+	/* Assign index to each PSC in device tree */
+	for_each_matching_node(np, mpc52xx_uart_of_match) {
+		match = of_match_node(mpc52xx_uart_of_match, np);
+		psc_ops = match->data;
+		mpc52xx_uart_of_assign(np);
+	}
+
+	enum_done = 1;
+
+	for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) {
+		if (mpc52xx_uart_nodes[i])
+			pr_debug("%pOF assigned to ttyPSC%x\n",
+				 mpc52xx_uart_nodes[i], i);
+	}
+}
+
+MODULE_DEVICE_TABLE(of, mpc52xx_uart_of_match);
+
+static struct platform_driver mpc52xx_uart_of_driver = {
+	.probe		= mpc52xx_uart_of_probe,
+	.remove		= mpc52xx_uart_of_remove,
+#ifdef CONFIG_PM
+	.suspend	= mpc52xx_uart_of_suspend,
+	.resume		= mpc52xx_uart_of_resume,
+#endif
+	.driver = {
+		.name = "mpc52xx-psc-uart",
+		.of_match_table = mpc52xx_uart_of_match,
+	},
+};
+
+
+/* ======================================================================== */
+/* Module                                                                   */
+/* ======================================================================== */
+
+static int __init
+mpc52xx_uart_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Serial: MPC52xx PSC UART driver\n");
+
+	ret = uart_register_driver(&mpc52xx_uart_driver);
+	if (ret) {
+		printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
+		       __FILE__, ret);
+		return ret;
+	}
+
+	mpc52xx_uart_of_enumerate();
+
+	/*
+	 * Map the PSC FIFO Controller and init if on MPC512x.
+	 */
+	if (psc_ops && psc_ops->fifoc_init) {
+		ret = psc_ops->fifoc_init();
+		if (ret)
+			goto err_init;
+	}
+
+	ret = platform_driver_register(&mpc52xx_uart_of_driver);
+	if (ret) {
+		printk(KERN_ERR "%s: platform_driver_register failed (%i)\n",
+		       __FILE__, ret);
+		goto err_reg;
+	}
+
+	return 0;
+err_reg:
+	if (psc_ops && psc_ops->fifoc_uninit)
+		psc_ops->fifoc_uninit();
+err_init:
+	uart_unregister_driver(&mpc52xx_uart_driver);
+	return ret;
+}
+
+static void __exit
+mpc52xx_uart_exit(void)
+{
+	if (psc_ops->fifoc_uninit)
+		psc_ops->fifoc_uninit();
+
+	platform_driver_unregister(&mpc52xx_uart_of_driver);
+	uart_unregister_driver(&mpc52xx_uart_driver);
+}
+
+
+module_init(mpc52xx_uart_init);
+module_exit(mpc52xx_uart_exit);
+
+MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
+MODULE_DESCRIPTION("Freescale MPC52xx PSC UART");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
new file mode 100644
index 000000000..ea5a7911c
--- /dev/null
+++ b/drivers/tty/serial/mps2-uart.c
@@ -0,0 +1,635 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MPS2 UART driver
+ *
+ * Copyright (C) 2015 ARM Limited
+ *
+ * Author: Vladimir Murzin <vladimir.murzin@arm.com>
+ *
+ * TODO: support for SysRq
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+#include <linux/idr.h>
+
+#define SERIAL_NAME	"ttyMPS"
+#define DRIVER_NAME	"mps2-uart"
+#define MAKE_NAME(x)	(DRIVER_NAME # x)
+
+#define UARTn_DATA				0x00
+
+#define UARTn_STATE				0x04
+#define UARTn_STATE_TX_FULL			BIT(0)
+#define UARTn_STATE_RX_FULL			BIT(1)
+#define UARTn_STATE_TX_OVERRUN			BIT(2)
+#define UARTn_STATE_RX_OVERRUN			BIT(3)
+
+#define UARTn_CTRL				0x08
+#define UARTn_CTRL_TX_ENABLE			BIT(0)
+#define UARTn_CTRL_RX_ENABLE			BIT(1)
+#define UARTn_CTRL_TX_INT_ENABLE		BIT(2)
+#define UARTn_CTRL_RX_INT_ENABLE		BIT(3)
+#define UARTn_CTRL_TX_OVERRUN_INT_ENABLE	BIT(4)
+#define UARTn_CTRL_RX_OVERRUN_INT_ENABLE	BIT(5)
+
+#define UARTn_INT				0x0c
+#define UARTn_INT_TX				BIT(0)
+#define UARTn_INT_RX				BIT(1)
+#define UARTn_INT_TX_OVERRUN			BIT(2)
+#define UARTn_INT_RX_OVERRUN			BIT(3)
+
+#define UARTn_BAUDDIV				0x10
+#define UARTn_BAUDDIV_MASK			GENMASK(20, 0)
+
+/*
+ * Helpers to make typical enable/disable operations more readable.
+ */
+#define UARTn_CTRL_TX_GRP	(UARTn_CTRL_TX_ENABLE		 |\
+				 UARTn_CTRL_TX_INT_ENABLE	 |\
+				 UARTn_CTRL_TX_OVERRUN_INT_ENABLE)
+
+#define UARTn_CTRL_RX_GRP	(UARTn_CTRL_RX_ENABLE		 |\
+				 UARTn_CTRL_RX_INT_ENABLE	 |\
+				 UARTn_CTRL_RX_OVERRUN_INT_ENABLE)
+
+#define MPS2_MAX_PORTS		3
+
+#define UART_PORT_COMBINED_IRQ	BIT(0)
+
+struct mps2_uart_port {
+	struct uart_port port;
+	struct clk *clk;
+	unsigned int tx_irq;
+	unsigned int rx_irq;
+	unsigned int flags;
+};
+
+static inline struct mps2_uart_port *to_mps2_port(struct uart_port *port)
+{
+	return container_of(port, struct mps2_uart_port, port);
+}
+
+static void mps2_uart_write8(struct uart_port *port, u8 val, unsigned int off)
+{
+	struct mps2_uart_port *mps_port = to_mps2_port(port);
+
+	writeb(val, mps_port->port.membase + off);
+}
+
+static u8 mps2_uart_read8(struct uart_port *port, unsigned int off)
+{
+	struct mps2_uart_port *mps_port = to_mps2_port(port);
+
+	return readb(mps_port->port.membase + off);
+}
+
+static void mps2_uart_write32(struct uart_port *port, u32 val, unsigned int off)
+{
+	struct mps2_uart_port *mps_port = to_mps2_port(port);
+
+	writel_relaxed(val, mps_port->port.membase + off);
+}
+
+static unsigned int mps2_uart_tx_empty(struct uart_port *port)
+{
+	u8 status = mps2_uart_read8(port, UARTn_STATE);
+
+	return (status & UARTn_STATE_TX_FULL) ? 0 : TIOCSER_TEMT;
+}
+
+static void mps2_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int mps2_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
+}
+
+static void mps2_uart_stop_tx(struct uart_port *port)
+{
+	u8 control = mps2_uart_read8(port, UARTn_CTRL);
+
+	control &= ~UARTn_CTRL_TX_INT_ENABLE;
+
+	mps2_uart_write8(port, control, UARTn_CTRL);
+}
+
+static void mps2_uart_tx_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		mps2_uart_tx_empty(port),
+		mps2_uart_write8(port, ch, UARTn_DATA));
+}
+
+static void mps2_uart_start_tx(struct uart_port *port)
+{
+	u8 control = mps2_uart_read8(port, UARTn_CTRL);
+
+	control |= UARTn_CTRL_TX_INT_ENABLE;
+
+	mps2_uart_write8(port, control, UARTn_CTRL);
+
+	/*
+	 * We've just unmasked the TX IRQ and now slow-starting via
+	 * polling; if there is enough data to fill up the internal
+	 * write buffer in one go, the TX IRQ should assert, at which
+	 * point we switch to fully interrupt-driven TX.
+	 */
+
+	mps2_uart_tx_chars(port);
+}
+
+static void mps2_uart_stop_rx(struct uart_port *port)
+{
+	u8 control = mps2_uart_read8(port, UARTn_CTRL);
+
+	control &= ~UARTn_CTRL_RX_GRP;
+
+	mps2_uart_write8(port, control, UARTn_CTRL);
+}
+
+static void mps2_uart_break_ctl(struct uart_port *port, int ctl)
+{
+}
+
+static void mps2_uart_rx_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+
+	while (mps2_uart_read8(port, UARTn_STATE) & UARTn_STATE_RX_FULL) {
+		u8 rxdata = mps2_uart_read8(port, UARTn_DATA);
+
+		port->icount.rx++;
+		tty_insert_flip_char(&port->state->port, rxdata, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(tport);
+}
+
+static irqreturn_t mps2_uart_rxirq(int irq, void *data)
+{
+	struct uart_port *port = data;
+	u8 irqflag = mps2_uart_read8(port, UARTn_INT);
+
+	if (unlikely(!(irqflag & UARTn_INT_RX)))
+		return IRQ_NONE;
+
+	spin_lock(&port->lock);
+
+	mps2_uart_write8(port, UARTn_INT_RX, UARTn_INT);
+	mps2_uart_rx_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mps2_uart_txirq(int irq, void *data)
+{
+	struct uart_port *port = data;
+	u8 irqflag = mps2_uart_read8(port, UARTn_INT);
+
+	if (unlikely(!(irqflag & UARTn_INT_TX)))
+		return IRQ_NONE;
+
+	spin_lock(&port->lock);
+
+	mps2_uart_write8(port, UARTn_INT_TX, UARTn_INT);
+	mps2_uart_tx_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
+{
+	irqreturn_t handled = IRQ_NONE;
+	struct uart_port *port = data;
+	u8 irqflag = mps2_uart_read8(port, UARTn_INT);
+
+	spin_lock(&port->lock);
+
+	if (irqflag & UARTn_INT_RX_OVERRUN) {
+		struct tty_port *tport = &port->state->port;
+
+		mps2_uart_write8(port, UARTn_INT_RX_OVERRUN, UARTn_INT);
+		port->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+		tty_flip_buffer_push(tport);
+		handled = IRQ_HANDLED;
+	}
+
+	/*
+	 * It's never been seen in practice and it never *should* happen since
+	 * we check if there is enough room in TX buffer before sending data.
+	 * So we keep this check in case something suspicious has happened.
+	 */
+	if (irqflag & UARTn_INT_TX_OVERRUN) {
+		mps2_uart_write8(port, UARTn_INT_TX_OVERRUN, UARTn_INT);
+		handled = IRQ_HANDLED;
+	}
+
+	spin_unlock(&port->lock);
+
+	return handled;
+}
+
+static irqreturn_t mps2_uart_combinedirq(int irq, void *data)
+{
+	if (mps2_uart_rxirq(irq, data) == IRQ_HANDLED)
+		return IRQ_HANDLED;
+
+	if (mps2_uart_txirq(irq, data) == IRQ_HANDLED)
+		return IRQ_HANDLED;
+
+	if (mps2_uart_oerrirq(irq, data) == IRQ_HANDLED)
+		return IRQ_HANDLED;
+
+	return IRQ_NONE;
+}
+
+static int mps2_uart_startup(struct uart_port *port)
+{
+	struct mps2_uart_port *mps_port = to_mps2_port(port);
+	u8 control = mps2_uart_read8(port, UARTn_CTRL);
+	int ret;
+
+	control &= ~(UARTn_CTRL_RX_GRP | UARTn_CTRL_TX_GRP);
+
+	mps2_uart_write8(port, control, UARTn_CTRL);
+
+	if (mps_port->flags & UART_PORT_COMBINED_IRQ) {
+		ret = request_irq(port->irq, mps2_uart_combinedirq, 0,
+				  MAKE_NAME(-combined), mps_port);
+
+		if (ret) {
+			dev_err(port->dev, "failed to register combinedirq (%d)\n", ret);
+			return ret;
+		}
+	} else {
+		ret = request_irq(port->irq, mps2_uart_oerrirq, IRQF_SHARED,
+				  MAKE_NAME(-overrun), mps_port);
+
+		if (ret) {
+			dev_err(port->dev, "failed to register oerrirq (%d)\n", ret);
+			return ret;
+		}
+
+		ret = request_irq(mps_port->rx_irq, mps2_uart_rxirq, 0,
+				  MAKE_NAME(-rx), mps_port);
+		if (ret) {
+			dev_err(port->dev, "failed to register rxirq (%d)\n", ret);
+			goto err_free_oerrirq;
+		}
+
+		ret = request_irq(mps_port->tx_irq, mps2_uart_txirq, 0,
+				  MAKE_NAME(-tx), mps_port);
+		if (ret) {
+			dev_err(port->dev, "failed to register txirq (%d)\n", ret);
+			goto err_free_rxirq;
+		}
+
+	}
+
+	control |= UARTn_CTRL_RX_GRP | UARTn_CTRL_TX_GRP;
+
+	mps2_uart_write8(port, control, UARTn_CTRL);
+
+	return 0;
+
+err_free_rxirq:
+	free_irq(mps_port->rx_irq, mps_port);
+err_free_oerrirq:
+	free_irq(port->irq, mps_port);
+
+	return ret;
+}
+
+static void mps2_uart_shutdown(struct uart_port *port)
+{
+	struct mps2_uart_port *mps_port = to_mps2_port(port);
+	u8 control = mps2_uart_read8(port, UARTn_CTRL);
+
+	control &= ~(UARTn_CTRL_RX_GRP | UARTn_CTRL_TX_GRP);
+
+	mps2_uart_write8(port, control, UARTn_CTRL);
+
+	if (!(mps_port->flags & UART_PORT_COMBINED_IRQ)) {
+		free_irq(mps_port->rx_irq, mps_port);
+		free_irq(mps_port->tx_irq, mps_port);
+	}
+
+	free_irq(port->irq, mps_port);
+}
+
+static void
+mps2_uart_set_termios(struct uart_port *port, struct ktermios *termios,
+		      const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, bauddiv;
+
+	termios->c_cflag &= ~(CRTSCTS | CMSPAR);
+	termios->c_cflag &= ~CSIZE;
+	termios->c_cflag |= CS8;
+	termios->c_cflag &= ~PARENB;
+	termios->c_cflag &= ~CSTOPB;
+
+	baud = uart_get_baud_rate(port, termios, old,
+			DIV_ROUND_CLOSEST(port->uartclk, UARTn_BAUDDIV_MASK),
+			DIV_ROUND_CLOSEST(port->uartclk, 16));
+
+	bauddiv = DIV_ROUND_CLOSEST(port->uartclk, baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	mps2_uart_write32(port, bauddiv, UARTn_BAUDDIV);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *mps2_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_MPS2UART) ? DRIVER_NAME : NULL;
+}
+
+static void mps2_uart_release_port(struct uart_port *port)
+{
+}
+
+static int mps2_uart_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void mps2_uart_config_port(struct uart_port *port, int type)
+{
+	if (type & UART_CONFIG_TYPE && !mps2_uart_request_port(port))
+		port->type = PORT_MPS2UART;
+}
+
+static int mps2_uart_verify_port(struct uart_port *port, struct serial_struct *serinfo)
+{
+	return -EINVAL;
+}
+
+static const struct uart_ops mps2_uart_pops = {
+	.tx_empty = mps2_uart_tx_empty,
+	.set_mctrl = mps2_uart_set_mctrl,
+	.get_mctrl = mps2_uart_get_mctrl,
+	.stop_tx = mps2_uart_stop_tx,
+	.start_tx = mps2_uart_start_tx,
+	.stop_rx = mps2_uart_stop_rx,
+	.break_ctl = mps2_uart_break_ctl,
+	.startup = mps2_uart_startup,
+	.shutdown = mps2_uart_shutdown,
+	.set_termios = mps2_uart_set_termios,
+	.type = mps2_uart_type,
+	.release_port = mps2_uart_release_port,
+	.request_port = mps2_uart_request_port,
+	.config_port = mps2_uart_config_port,
+	.verify_port = mps2_uart_verify_port,
+};
+
+static DEFINE_IDR(ports_idr);
+
+#ifdef CONFIG_SERIAL_MPS2_UART_CONSOLE
+static void mps2_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (mps2_uart_read8(port, UARTn_STATE) & UARTn_STATE_TX_FULL)
+		cpu_relax();
+
+	mps2_uart_write8(port, ch, UARTn_DATA);
+}
+
+static void mps2_uart_console_write(struct console *co, const char *s, unsigned int cnt)
+{
+	struct mps2_uart_port *mps_port = idr_find(&ports_idr, co->index);
+	struct uart_port *port = &mps_port->port;
+
+	uart_console_write(port, s, cnt, mps2_uart_console_putchar);
+}
+
+static int mps2_uart_console_setup(struct console *co, char *options)
+{
+	struct mps2_uart_port *mps_port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= MPS2_MAX_PORTS)
+		return -ENODEV;
+
+	mps_port = idr_find(&ports_idr, co->index);
+
+	if (!mps_port)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&mps_port->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver mps2_uart_driver;
+
+static struct console mps2_uart_console = {
+	.name = SERIAL_NAME,
+	.device = uart_console_device,
+	.write = mps2_uart_console_write,
+	.setup = mps2_uart_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &mps2_uart_driver,
+};
+
+#define MPS2_SERIAL_CONSOLE (&mps2_uart_console)
+
+static void mps2_early_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (readb(port->membase + UARTn_STATE) & UARTn_STATE_TX_FULL)
+		cpu_relax();
+
+	writeb((unsigned char)ch, port->membase + UARTn_DATA);
+}
+
+static void mps2_early_write(struct console *con, const char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, mps2_early_putchar);
+}
+
+static int __init mps2_early_console_setup(struct earlycon_device *device,
+					   const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = mps2_early_write;
+
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(mps2, "arm,mps2-uart", mps2_early_console_setup);
+
+#else
+#define MPS2_SERIAL_CONSOLE NULL
+#endif
+
+static struct uart_driver mps2_uart_driver = {
+	.driver_name = DRIVER_NAME,
+	.dev_name = SERIAL_NAME,
+	.nr = MPS2_MAX_PORTS,
+	.cons = MPS2_SERIAL_CONSOLE,
+};
+
+static int mps2_of_get_port(struct platform_device *pdev,
+			    struct mps2_uart_port *mps_port)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int id;
+
+	if (!np)
+		return -ENODEV;
+
+	id = of_alias_get_id(np, "serial");
+
+	if (id < 0)
+		id = idr_alloc_cyclic(&ports_idr, (void *)mps_port, 0, MPS2_MAX_PORTS, GFP_KERNEL);
+	else
+		id = idr_alloc(&ports_idr, (void *)mps_port, id, MPS2_MAX_PORTS, GFP_KERNEL);
+
+	if (id < 0)
+		return id;
+
+	/* Only combined irq is presesnt */
+	if (platform_irq_count(pdev) == 1)
+		mps_port->flags |= UART_PORT_COMBINED_IRQ;
+
+	mps_port->port.line = id;
+
+	return 0;
+}
+
+static int mps2_init_port(struct platform_device *pdev,
+			  struct mps2_uart_port *mps_port)
+{
+	struct resource *res;
+	int ret;
+
+	mps_port->port.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(mps_port->port.membase))
+		return PTR_ERR(mps_port->port.membase);
+
+	mps_port->port.mapbase = res->start;
+	mps_port->port.mapsize = resource_size(res);
+	mps_port->port.iotype = UPIO_MEM;
+	mps_port->port.flags = UPF_BOOT_AUTOCONF;
+	mps_port->port.fifosize = 1;
+	mps_port->port.ops = &mps2_uart_pops;
+	mps_port->port.dev = &pdev->dev;
+
+	mps_port->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(mps_port->clk))
+		return PTR_ERR(mps_port->clk);
+
+	ret = clk_prepare_enable(mps_port->clk);
+	if (ret)
+		return ret;
+
+	mps_port->port.uartclk = clk_get_rate(mps_port->clk);
+
+	clk_disable_unprepare(mps_port->clk);
+
+
+	if (mps_port->flags & UART_PORT_COMBINED_IRQ) {
+		mps_port->port.irq = platform_get_irq(pdev, 0);
+	} else {
+		mps_port->rx_irq = platform_get_irq(pdev, 0);
+		mps_port->tx_irq = platform_get_irq(pdev, 1);
+		mps_port->port.irq = platform_get_irq(pdev, 2);
+	}
+
+	return ret;
+}
+
+static int mps2_serial_probe(struct platform_device *pdev)
+{
+	struct mps2_uart_port *mps_port;
+	int ret;
+
+	mps_port = devm_kzalloc(&pdev->dev, sizeof(struct mps2_uart_port), GFP_KERNEL);
+
+        if (!mps_port)
+                return -ENOMEM;
+
+	ret = mps2_of_get_port(pdev, mps_port);
+	if (ret)
+		return ret;
+
+	ret = mps2_init_port(pdev, mps_port);
+	if (ret)
+		return ret;
+
+	ret = uart_add_one_port(&mps2_uart_driver, &mps_port->port);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, mps_port);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id mps2_match[] = {
+	{ .compatible = "arm,mps2-uart", },
+	{},
+};
+#endif
+
+static struct platform_driver mps2_serial_driver = {
+	.probe = mps2_serial_probe,
+
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = of_match_ptr(mps2_match),
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init mps2_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&mps2_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&mps2_serial_driver);
+	if (ret)
+		uart_unregister_driver(&mps2_uart_driver);
+
+	return ret;
+}
+arch_initcall(mps2_uart_init);
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
new file mode 100644
index 000000000..90953e679
--- /dev/null
+++ b/drivers/tty/serial/msm_serial.c
@@ -0,0 +1,1922 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for msm7k serial device and console
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Author: Robert Love <rlove@google.com>
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/atomic.h>
+#include <linux/dma/qcom_adm.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/wait.h>
+
+#define MSM_UART_MR1			0x0000
+
+#define MSM_UART_MR1_AUTO_RFR_LEVEL0	0x3F
+#define MSM_UART_MR1_AUTO_RFR_LEVEL1	0x3FF00
+#define MSM_UART_DM_MR1_AUTO_RFR_LEVEL1	0xFFFFFF00
+#define MSM_UART_MR1_RX_RDY_CTL		BIT(7)
+#define MSM_UART_MR1_CTS_CTL		BIT(6)
+
+#define MSM_UART_MR2			0x0004
+#define MSM_UART_MR2_ERROR_MODE		BIT(6)
+#define MSM_UART_MR2_BITS_PER_CHAR	0x30
+#define MSM_UART_MR2_BITS_PER_CHAR_5	(0x0 << 4)
+#define MSM_UART_MR2_BITS_PER_CHAR_6	(0x1 << 4)
+#define MSM_UART_MR2_BITS_PER_CHAR_7	(0x2 << 4)
+#define MSM_UART_MR2_BITS_PER_CHAR_8	(0x3 << 4)
+#define MSM_UART_MR2_STOP_BIT_LEN_ONE	(0x1 << 2)
+#define MSM_UART_MR2_STOP_BIT_LEN_TWO	(0x3 << 2)
+#define MSM_UART_MR2_PARITY_MODE_NONE	0x0
+#define MSM_UART_MR2_PARITY_MODE_ODD	0x1
+#define MSM_UART_MR2_PARITY_MODE_EVEN	0x2
+#define MSM_UART_MR2_PARITY_MODE_SPACE	0x3
+#define MSM_UART_MR2_PARITY_MODE	0x3
+
+#define MSM_UART_CSR			0x0008
+
+#define MSM_UART_TF			0x000C
+#define UARTDM_TF			0x0070
+
+#define MSM_UART_CR				0x0010
+#define MSM_UART_CR_CMD_NULL			(0 << 4)
+#define MSM_UART_CR_CMD_RESET_RX		(1 << 4)
+#define MSM_UART_CR_CMD_RESET_TX		(2 << 4)
+#define MSM_UART_CR_CMD_RESET_ERR		(3 << 4)
+#define MSM_UART_CR_CMD_RESET_BREAK_INT		(4 << 4)
+#define MSM_UART_CR_CMD_START_BREAK		(5 << 4)
+#define MSM_UART_CR_CMD_STOP_BREAK		(6 << 4)
+#define MSM_UART_CR_CMD_RESET_CTS		(7 << 4)
+#define MSM_UART_CR_CMD_RESET_STALE_INT		(8 << 4)
+#define MSM_UART_CR_CMD_PACKET_MODE		(9 << 4)
+#define MSM_UART_CR_CMD_MODE_RESET		(12 << 4)
+#define MSM_UART_CR_CMD_SET_RFR			(13 << 4)
+#define MSM_UART_CR_CMD_RESET_RFR		(14 << 4)
+#define MSM_UART_CR_CMD_PROTECTION_EN		(16 << 4)
+#define MSM_UART_CR_CMD_STALE_EVENT_DISABLE	(6 << 8)
+#define MSM_UART_CR_CMD_STALE_EVENT_ENABLE	(80 << 4)
+#define MSM_UART_CR_CMD_FORCE_STALE		(4 << 8)
+#define MSM_UART_CR_CMD_RESET_TX_READY		(3 << 8)
+#define MSM_UART_CR_TX_DISABLE			BIT(3)
+#define MSM_UART_CR_TX_ENABLE			BIT(2)
+#define MSM_UART_CR_RX_DISABLE			BIT(1)
+#define MSM_UART_CR_RX_ENABLE			BIT(0)
+#define MSM_UART_CR_CMD_RESET_RXBREAK_START	((1 << 11) | (2 << 4))
+
+#define MSM_UART_IMR			0x0014
+#define MSM_UART_IMR_TXLEV		BIT(0)
+#define MSM_UART_IMR_RXSTALE		BIT(3)
+#define MSM_UART_IMR_RXLEV		BIT(4)
+#define MSM_UART_IMR_DELTA_CTS		BIT(5)
+#define MSM_UART_IMR_CURRENT_CTS	BIT(6)
+#define MSM_UART_IMR_RXBREAK_START	BIT(10)
+
+#define MSM_UART_IPR_RXSTALE_LAST		0x20
+#define MSM_UART_IPR_STALE_LSB			0x1F
+#define MSM_UART_IPR_STALE_TIMEOUT_MSB		0x3FF80
+#define MSM_UART_DM_IPR_STALE_TIMEOUT_MSB	0xFFFFFF80
+
+#define MSM_UART_IPR			0x0018
+#define MSM_UART_TFWR			0x001C
+#define MSM_UART_RFWR			0x0020
+#define MSM_UART_HCR			0x0024
+
+#define MSM_UART_MREG			0x0028
+#define MSM_UART_NREG			0x002C
+#define MSM_UART_DREG			0x0030
+#define MSM_UART_MNDREG			0x0034
+#define MSM_UART_IRDA			0x0038
+#define MSM_UART_MISR_MODE		0x0040
+#define MSM_UART_MISR_RESET		0x0044
+#define MSM_UART_MISR_EXPORT		0x0048
+#define MSM_UART_MISR_VAL		0x004C
+#define MSM_UART_TEST_CTRL		0x0050
+
+#define MSM_UART_SR			0x0008
+#define MSM_UART_SR_HUNT_CHAR		BIT(7)
+#define MSM_UART_SR_RX_BREAK		BIT(6)
+#define MSM_UART_SR_PAR_FRAME_ERR	BIT(5)
+#define MSM_UART_SR_OVERRUN		BIT(4)
+#define MSM_UART_SR_TX_EMPTY		BIT(3)
+#define MSM_UART_SR_TX_READY		BIT(2)
+#define MSM_UART_SR_RX_FULL		BIT(1)
+#define MSM_UART_SR_RX_READY		BIT(0)
+
+#define MSM_UART_RF			0x000C
+#define UARTDM_RF			0x0070
+#define MSM_UART_MISR			0x0010
+#define MSM_UART_ISR			0x0014
+#define MSM_UART_ISR_TX_READY		BIT(7)
+
+#define UARTDM_RXFS			0x50
+#define UARTDM_RXFS_BUF_SHIFT		0x7
+#define UARTDM_RXFS_BUF_MASK		0x7
+
+#define UARTDM_DMEN			0x3C
+#define UARTDM_DMEN_RX_SC_ENABLE	BIT(5)
+#define UARTDM_DMEN_TX_SC_ENABLE	BIT(4)
+
+#define UARTDM_DMEN_TX_BAM_ENABLE	BIT(2)	/* UARTDM_1P4 */
+#define UARTDM_DMEN_TX_DM_ENABLE	BIT(0)	/* < UARTDM_1P4 */
+
+#define UARTDM_DMEN_RX_BAM_ENABLE	BIT(3)	/* UARTDM_1P4 */
+#define UARTDM_DMEN_RX_DM_ENABLE	BIT(1)	/* < UARTDM_1P4 */
+
+#define UARTDM_DMRX			0x34
+#define UARTDM_NCF_TX			0x40
+#define UARTDM_RX_TOTAL_SNAP		0x38
+
+#define UARTDM_BURST_SIZE		16   /* in bytes */
+#define UARTDM_TX_AIGN(x)		((x) & ~0x3) /* valid for > 1p3 */
+#define UARTDM_TX_MAX			256   /* in bytes, valid for <= 1p3 */
+#define UARTDM_RX_SIZE			(UART_XMIT_SIZE / 4)
+
+enum {
+	UARTDM_1P1 = 1,
+	UARTDM_1P2,
+	UARTDM_1P3,
+	UARTDM_1P4,
+};
+
+struct msm_dma {
+	struct dma_chan		*chan;
+	enum dma_data_direction dir;
+	dma_addr_t		phys;
+	unsigned char		*virt;
+	dma_cookie_t		cookie;
+	u32			enable_bit;
+	unsigned int		count;
+	struct dma_async_tx_descriptor	*desc;
+};
+
+struct msm_port {
+	struct uart_port	uart;
+	char			name[16];
+	struct clk		*clk;
+	struct clk		*pclk;
+	unsigned int		imr;
+	int			is_uartdm;
+	unsigned int		old_snap_state;
+	bool			break_detected;
+	struct msm_dma		tx_dma;
+	struct msm_dma		rx_dma;
+};
+
+static inline struct msm_port *to_msm_port(struct uart_port *up)
+{
+	return container_of(up, struct msm_port, uart);
+}
+
+static
+void msm_write(struct uart_port *port, unsigned int val, unsigned int off)
+{
+	writel_relaxed(val, port->membase + off);
+}
+
+static
+unsigned int msm_read(struct uart_port *port, unsigned int off)
+{
+	return readl_relaxed(port->membase + off);
+}
+
+/*
+ * Setup the MND registers to use the TCXO clock.
+ */
+static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port)
+{
+	msm_write(port, 0x06, MSM_UART_MREG);
+	msm_write(port, 0xF1, MSM_UART_NREG);
+	msm_write(port, 0x0F, MSM_UART_DREG);
+	msm_write(port, 0x1A, MSM_UART_MNDREG);
+	port->uartclk = 1843200;
+}
+
+/*
+ * Setup the MND registers to use the TCXO clock divided by 4.
+ */
+static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port)
+{
+	msm_write(port, 0x18, MSM_UART_MREG);
+	msm_write(port, 0xF6, MSM_UART_NREG);
+	msm_write(port, 0x0F, MSM_UART_DREG);
+	msm_write(port, 0x0A, MSM_UART_MNDREG);
+	port->uartclk = 1843200;
+}
+
+static void msm_serial_set_mnd_regs(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+
+	/*
+	 * These registers don't exist so we change the clk input rate
+	 * on uartdm hardware instead
+	 */
+	if (msm_port->is_uartdm)
+		return;
+
+	if (port->uartclk == 19200000)
+		msm_serial_set_mnd_regs_tcxo(port);
+	else if (port->uartclk == 4800000)
+		msm_serial_set_mnd_regs_tcxoby4(port);
+}
+
+static void msm_handle_tx(struct uart_port *port);
+static void msm_start_rx_dma(struct msm_port *msm_port);
+
+static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma)
+{
+	struct device *dev = port->dev;
+	unsigned int mapped;
+	u32 val;
+
+	mapped = dma->count;
+	dma->count = 0;
+
+	dmaengine_terminate_all(dma->chan);
+
+	/*
+	 * DMA Stall happens if enqueue and flush command happens concurrently.
+	 * For example before changing the baud rate/protocol configuration and
+	 * sending flush command to ADM, disable the channel of UARTDM.
+	 * Note: should not reset the receiver here immediately as it is not
+	 * suggested to do disable/reset or reset/disable at the same time.
+	 */
+	val = msm_read(port, UARTDM_DMEN);
+	val &= ~dma->enable_bit;
+	msm_write(port, val, UARTDM_DMEN);
+
+	if (mapped)
+		dma_unmap_single(dev, dma->phys, mapped, dma->dir);
+}
+
+static void msm_release_dma(struct msm_port *msm_port)
+{
+	struct msm_dma *dma;
+
+	dma = &msm_port->tx_dma;
+	if (dma->chan) {
+		msm_stop_dma(&msm_port->uart, dma);
+		dma_release_channel(dma->chan);
+	}
+
+	memset(dma, 0, sizeof(*dma));
+
+	dma = &msm_port->rx_dma;
+	if (dma->chan) {
+		msm_stop_dma(&msm_port->uart, dma);
+		dma_release_channel(dma->chan);
+		kfree(dma->virt);
+	}
+
+	memset(dma, 0, sizeof(*dma));
+}
+
+static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base)
+{
+	struct device *dev = msm_port->uart.dev;
+	struct dma_slave_config conf;
+	struct qcom_adm_peripheral_config periph_conf = {};
+	struct msm_dma *dma;
+	u32 crci = 0;
+	int ret;
+
+	dma = &msm_port->tx_dma;
+
+	/* allocate DMA resources, if available */
+	dma->chan = dma_request_chan(dev, "tx");
+	if (IS_ERR(dma->chan))
+		goto no_tx;
+
+	of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci);
+
+	memset(&conf, 0, sizeof(conf));
+	conf.direction = DMA_MEM_TO_DEV;
+	conf.device_fc = true;
+	conf.dst_addr = base + UARTDM_TF;
+	conf.dst_maxburst = UARTDM_BURST_SIZE;
+	if (crci) {
+		conf.peripheral_config = &periph_conf;
+		conf.peripheral_size = sizeof(periph_conf);
+		periph_conf.crci = crci;
+	}
+
+	ret = dmaengine_slave_config(dma->chan, &conf);
+	if (ret)
+		goto rel_tx;
+
+	dma->dir = DMA_TO_DEVICE;
+
+	if (msm_port->is_uartdm < UARTDM_1P4)
+		dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE;
+	else
+		dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE;
+
+	return;
+
+rel_tx:
+	dma_release_channel(dma->chan);
+no_tx:
+	memset(dma, 0, sizeof(*dma));
+}
+
+static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base)
+{
+	struct device *dev = msm_port->uart.dev;
+	struct dma_slave_config conf;
+	struct qcom_adm_peripheral_config periph_conf = {};
+	struct msm_dma *dma;
+	u32 crci = 0;
+	int ret;
+
+	dma = &msm_port->rx_dma;
+
+	/* allocate DMA resources, if available */
+	dma->chan = dma_request_chan(dev, "rx");
+	if (IS_ERR(dma->chan))
+		goto no_rx;
+
+	of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci);
+
+	dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL);
+	if (!dma->virt)
+		goto rel_rx;
+
+	memset(&conf, 0, sizeof(conf));
+	conf.direction = DMA_DEV_TO_MEM;
+	conf.device_fc = true;
+	conf.src_addr = base + UARTDM_RF;
+	conf.src_maxburst = UARTDM_BURST_SIZE;
+	if (crci) {
+		conf.peripheral_config = &periph_conf;
+		conf.peripheral_size = sizeof(periph_conf);
+		periph_conf.crci = crci;
+	}
+
+	ret = dmaengine_slave_config(dma->chan, &conf);
+	if (ret)
+		goto err;
+
+	dma->dir = DMA_FROM_DEVICE;
+
+	if (msm_port->is_uartdm < UARTDM_1P4)
+		dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE;
+	else
+		dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE;
+
+	return;
+err:
+	kfree(dma->virt);
+rel_rx:
+	dma_release_channel(dma->chan);
+no_rx:
+	memset(dma, 0, sizeof(*dma));
+}
+
+static inline void msm_wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int timeout = 500000;
+
+	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY)) {
+		if (msm_read(port, MSM_UART_ISR) & MSM_UART_ISR_TX_READY)
+			break;
+		udelay(1);
+		if (!timeout--)
+			break;
+	}
+	msm_write(port, MSM_UART_CR_CMD_RESET_TX_READY, MSM_UART_CR);
+}
+
+static void msm_stop_tx(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+
+	msm_port->imr &= ~MSM_UART_IMR_TXLEV;
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+}
+
+static void msm_start_tx(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	struct msm_dma *dma = &msm_port->tx_dma;
+
+	/* Already started in DMA mode */
+	if (dma->count)
+		return;
+
+	msm_port->imr |= MSM_UART_IMR_TXLEV;
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+}
+
+static void msm_reset_dm_count(struct uart_port *port, int count)
+{
+	msm_wait_for_xmitr(port);
+	msm_write(port, count, UARTDM_NCF_TX);
+	msm_read(port, UARTDM_NCF_TX);
+}
+
+static void msm_complete_tx_dma(void *args)
+{
+	struct msm_port *msm_port = args;
+	struct uart_port *port = &msm_port->uart;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct msm_dma *dma = &msm_port->tx_dma;
+	struct dma_tx_state state;
+	unsigned long flags;
+	unsigned int count;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Already stopped */
+	if (!dma->count)
+		goto done;
+
+	dmaengine_tx_status(dma->chan, dma->cookie, &state);
+
+	dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir);
+
+	val = msm_read(port, UARTDM_DMEN);
+	val &= ~dma->enable_bit;
+	msm_write(port, val, UARTDM_DMEN);
+
+	if (msm_port->is_uartdm > UARTDM_1P3) {
+		msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR);
+		msm_write(port, MSM_UART_CR_TX_ENABLE, MSM_UART_CR);
+	}
+
+	count = dma->count - state.residue;
+	uart_xmit_advance(port, count);
+	dma->count = 0;
+
+	/* Restore "Tx FIFO below watermark" interrupt */
+	msm_port->imr |= MSM_UART_IMR_TXLEV;
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	msm_handle_tx(port);
+done:
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
+{
+	struct circ_buf *xmit = &msm_port->uart.state->xmit;
+	struct uart_port *port = &msm_port->uart;
+	struct msm_dma *dma = &msm_port->tx_dma;
+	void *cpu_addr;
+	int ret;
+	u32 val;
+
+	cpu_addr = &xmit->buf[xmit->tail];
+
+	dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir);
+	ret = dma_mapping_error(port->dev, dma->phys);
+	if (ret)
+		return ret;
+
+	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
+						count, DMA_MEM_TO_DEV,
+						DMA_PREP_INTERRUPT |
+						DMA_PREP_FENCE);
+	if (!dma->desc) {
+		ret = -EIO;
+		goto unmap;
+	}
+
+	dma->desc->callback = msm_complete_tx_dma;
+	dma->desc->callback_param = msm_port;
+
+	dma->cookie = dmaengine_submit(dma->desc);
+	ret = dma_submit_error(dma->cookie);
+	if (ret)
+		goto unmap;
+
+	/*
+	 * Using DMA complete for Tx FIFO reload, no need for
+	 * "Tx FIFO below watermark" one, disable it
+	 */
+	msm_port->imr &= ~MSM_UART_IMR_TXLEV;
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+
+	dma->count = count;
+
+	val = msm_read(port, UARTDM_DMEN);
+	val |= dma->enable_bit;
+
+	if (msm_port->is_uartdm < UARTDM_1P4)
+		msm_write(port, val, UARTDM_DMEN);
+
+	msm_reset_dm_count(port, count);
+
+	if (msm_port->is_uartdm > UARTDM_1P3)
+		msm_write(port, val, UARTDM_DMEN);
+
+	dma_async_issue_pending(dma->chan);
+	return 0;
+unmap:
+	dma_unmap_single(port->dev, dma->phys, count, dma->dir);
+	return ret;
+}
+
+static void msm_complete_rx_dma(void *args)
+{
+	struct msm_port *msm_port = args;
+	struct uart_port *port = &msm_port->uart;
+	struct tty_port *tport = &port->state->port;
+	struct msm_dma *dma = &msm_port->rx_dma;
+	int count = 0, i, sysrq;
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Already stopped */
+	if (!dma->count)
+		goto done;
+
+	val = msm_read(port, UARTDM_DMEN);
+	val &= ~dma->enable_bit;
+	msm_write(port, val, UARTDM_DMEN);
+
+	if (msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN) {
+		port->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
+	}
+
+	count = msm_read(port, UARTDM_RX_TOTAL_SNAP);
+
+	port->icount.rx += count;
+
+	dma->count = 0;
+
+	dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
+
+	for (i = 0; i < count; i++) {
+		char flag = TTY_NORMAL;
+
+		if (msm_port->break_detected && dma->virt[i] == 0) {
+			port->icount.brk++;
+			flag = TTY_BREAK;
+			msm_port->break_detected = false;
+			if (uart_handle_break(port))
+				continue;
+		}
+
+		if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
+			flag = TTY_NORMAL;
+
+		spin_unlock_irqrestore(&port->lock, flags);
+		sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
+		spin_lock_irqsave(&port->lock, flags);
+		if (!sysrq)
+			tty_insert_flip_char(tport, dma->virt[i], flag);
+	}
+
+	msm_start_rx_dma(msm_port);
+done:
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (count)
+		tty_flip_buffer_push(tport);
+}
+
+static void msm_start_rx_dma(struct msm_port *msm_port)
+{
+	struct msm_dma *dma = &msm_port->rx_dma;
+	struct uart_port *uart = &msm_port->uart;
+	u32 val;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_CONSOLE_POLL))
+		return;
+
+	if (!dma->chan)
+		return;
+
+	dma->phys = dma_map_single(uart->dev, dma->virt,
+				   UARTDM_RX_SIZE, dma->dir);
+	ret = dma_mapping_error(uart->dev, dma->phys);
+	if (ret)
+		goto sw_mode;
+
+	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
+						UARTDM_RX_SIZE, DMA_DEV_TO_MEM,
+						DMA_PREP_INTERRUPT);
+	if (!dma->desc)
+		goto unmap;
+
+	dma->desc->callback = msm_complete_rx_dma;
+	dma->desc->callback_param = msm_port;
+
+	dma->cookie = dmaengine_submit(dma->desc);
+	ret = dma_submit_error(dma->cookie);
+	if (ret)
+		goto unmap;
+	/*
+	 * Using DMA for FIFO off-load, no need for "Rx FIFO over
+	 * watermark" or "stale" interrupts, disable them
+	 */
+	msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE);
+
+	/*
+	 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3),
+	 * we need RXSTALE to flush input DMA fifo to memory
+	 */
+	if (msm_port->is_uartdm < UARTDM_1P4)
+		msm_port->imr |= MSM_UART_IMR_RXSTALE;
+
+	msm_write(uart, msm_port->imr, MSM_UART_IMR);
+
+	dma->count = UARTDM_RX_SIZE;
+
+	dma_async_issue_pending(dma->chan);
+
+	msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
+	msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
+
+	val = msm_read(uart, UARTDM_DMEN);
+	val |= dma->enable_bit;
+
+	if (msm_port->is_uartdm < UARTDM_1P4)
+		msm_write(uart, val, UARTDM_DMEN);
+
+	msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX);
+
+	if (msm_port->is_uartdm > UARTDM_1P3)
+		msm_write(uart, val, UARTDM_DMEN);
+
+	return;
+unmap:
+	dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
+
+sw_mode:
+	/*
+	 * Switch from DMA to SW/FIFO mode. After clearing Rx BAM (UARTDM_DMEN),
+	 * receiver must be reset.
+	 */
+	msm_write(uart, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR);
+	msm_write(uart, MSM_UART_CR_RX_ENABLE, MSM_UART_CR);
+
+	msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
+	msm_write(uart, 0xFFFFFF, UARTDM_DMRX);
+	msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
+
+	/* Re-enable RX interrupts */
+	msm_port->imr |= MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE;
+	msm_write(uart, msm_port->imr, MSM_UART_IMR);
+}
+
+static void msm_stop_rx(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	struct msm_dma *dma = &msm_port->rx_dma;
+
+	msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE);
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+
+	if (dma->chan)
+		msm_stop_dma(port, dma);
+}
+
+static void msm_enable_ms(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+
+	msm_port->imr |= MSM_UART_IMR_DELTA_CTS;
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+}
+
+static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
+	__must_hold(&port->lock)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned int sr;
+	int count = 0;
+	struct msm_port *msm_port = to_msm_port(port);
+
+	if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) {
+		port->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
+	}
+
+	if (misr & MSM_UART_IMR_RXSTALE) {
+		count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
+			msm_port->old_snap_state;
+		msm_port->old_snap_state = 0;
+	} else {
+		count = 4 * (msm_read(port, MSM_UART_RFWR));
+		msm_port->old_snap_state += count;
+	}
+
+	/* TODO: Precise error reporting */
+
+	port->icount.rx += count;
+
+	while (count > 0) {
+		unsigned char buf[4];
+		int sysrq, r_count, i;
+
+		sr = msm_read(port, MSM_UART_SR);
+		if ((sr & MSM_UART_SR_RX_READY) == 0) {
+			msm_port->old_snap_state -= count;
+			break;
+		}
+
+		ioread32_rep(port->membase + UARTDM_RF, buf, 1);
+		r_count = min_t(int, count, sizeof(buf));
+
+		for (i = 0; i < r_count; i++) {
+			char flag = TTY_NORMAL;
+
+			if (msm_port->break_detected && buf[i] == 0) {
+				port->icount.brk++;
+				flag = TTY_BREAK;
+				msm_port->break_detected = false;
+				if (uart_handle_break(port))
+					continue;
+			}
+
+			if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
+				flag = TTY_NORMAL;
+
+			spin_unlock(&port->lock);
+			sysrq = uart_handle_sysrq_char(port, buf[i]);
+			spin_lock(&port->lock);
+			if (!sysrq)
+				tty_insert_flip_char(tport, buf[i], flag);
+		}
+		count -= r_count;
+	}
+
+	tty_flip_buffer_push(tport);
+
+	if (misr & (MSM_UART_IMR_RXSTALE))
+		msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
+	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
+	msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
+
+	/* Try to use DMA */
+	msm_start_rx_dma(msm_port);
+}
+
+static void msm_handle_rx(struct uart_port *port)
+	__must_hold(&port->lock)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned int sr;
+
+	/*
+	 * Handle overrun. My understanding of the hardware is that overrun
+	 * is not tied to the RX buffer, so we handle the case out of band.
+	 */
+	if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) {
+		port->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
+	}
+
+	/* and now the main RX loop */
+	while ((sr = msm_read(port, MSM_UART_SR)) & MSM_UART_SR_RX_READY) {
+		unsigned int c;
+		char flag = TTY_NORMAL;
+		int sysrq;
+
+		c = msm_read(port, MSM_UART_RF);
+
+		if (sr & MSM_UART_SR_RX_BREAK) {
+			port->icount.brk++;
+			if (uart_handle_break(port))
+				continue;
+		} else if (sr & MSM_UART_SR_PAR_FRAME_ERR) {
+			port->icount.frame++;
+		} else {
+			port->icount.rx++;
+		}
+
+		/* Mask conditions we're ignoring. */
+		sr &= port->read_status_mask;
+
+		if (sr & MSM_UART_SR_RX_BREAK)
+			flag = TTY_BREAK;
+		else if (sr & MSM_UART_SR_PAR_FRAME_ERR)
+			flag = TTY_FRAME;
+
+		spin_unlock(&port->lock);
+		sysrq = uart_handle_sysrq_char(port, c);
+		spin_lock(&port->lock);
+		if (!sysrq)
+			tty_insert_flip_char(tport, c, flag);
+	}
+
+	tty_flip_buffer_push(tport);
+}
+
+static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	struct msm_port *msm_port = to_msm_port(port);
+	unsigned int num_chars;
+	unsigned int tf_pointer = 0;
+	void __iomem *tf;
+
+	if (msm_port->is_uartdm)
+		tf = port->membase + UARTDM_TF;
+	else
+		tf = port->membase + MSM_UART_TF;
+
+	if (tx_count && msm_port->is_uartdm)
+		msm_reset_dm_count(port, tx_count);
+
+	while (tf_pointer < tx_count) {
+		int i;
+		char buf[4] = { 0 };
+
+		if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
+			break;
+
+		if (msm_port->is_uartdm)
+			num_chars = min(tx_count - tf_pointer,
+					(unsigned int)sizeof(buf));
+		else
+			num_chars = 1;
+
+		for (i = 0; i < num_chars; i++)
+			buf[i] = xmit->buf[xmit->tail + i];
+
+		iowrite32_rep(tf, buf, 1);
+		uart_xmit_advance(port, num_chars);
+		tf_pointer += num_chars;
+	}
+
+	/* disable tx interrupts if nothing more to send */
+	if (uart_circ_empty(xmit))
+		msm_stop_tx(port);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static void msm_handle_tx(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	struct circ_buf *xmit = &msm_port->uart.state->xmit;
+	struct msm_dma *dma = &msm_port->tx_dma;
+	unsigned int pio_count, dma_count, dma_min;
+	char buf[4] = { 0 };
+	void __iomem *tf;
+	int err = 0;
+
+	if (port->x_char) {
+		if (msm_port->is_uartdm)
+			tf = port->membase + UARTDM_TF;
+		else
+			tf = port->membase + MSM_UART_TF;
+
+		buf[0] = port->x_char;
+
+		if (msm_port->is_uartdm)
+			msm_reset_dm_count(port, 1);
+
+		iowrite32_rep(tf, buf, 1);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		msm_stop_tx(port);
+		return;
+	}
+
+	pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	dma_min = 1;	/* Always DMA */
+	if (msm_port->is_uartdm > UARTDM_1P3) {
+		dma_count = UARTDM_TX_AIGN(dma_count);
+		dma_min = UARTDM_BURST_SIZE;
+	} else {
+		if (dma_count > UARTDM_TX_MAX)
+			dma_count = UARTDM_TX_MAX;
+	}
+
+	if (pio_count > port->fifosize)
+		pio_count = port->fifosize;
+
+	if (!dma->chan || dma_count < dma_min)
+		msm_handle_tx_pio(port, pio_count);
+	else
+		err = msm_handle_tx_dma(msm_port, dma_count);
+
+	if (err)	/* fall back to PIO mode */
+		msm_handle_tx_pio(port, pio_count);
+}
+
+static void msm_handle_delta_cts(struct uart_port *port)
+{
+	msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR);
+	port->icount.cts++;
+	wake_up_interruptible(&port->state->port.delta_msr_wait);
+}
+
+static irqreturn_t msm_uart_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct msm_port *msm_port = to_msm_port(port);
+	struct msm_dma *dma = &msm_port->rx_dma;
+	unsigned long flags;
+	unsigned int misr;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+	misr = msm_read(port, MSM_UART_MISR);
+	msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */
+
+	if (misr & MSM_UART_IMR_RXBREAK_START) {
+		msm_port->break_detected = true;
+		msm_write(port, MSM_UART_CR_CMD_RESET_RXBREAK_START, MSM_UART_CR);
+	}
+
+	if (misr & (MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE)) {
+		if (dma->count) {
+			val = MSM_UART_CR_CMD_STALE_EVENT_DISABLE;
+			msm_write(port, val, MSM_UART_CR);
+			val = MSM_UART_CR_CMD_RESET_STALE_INT;
+			msm_write(port, val, MSM_UART_CR);
+			/*
+			 * Flush DMA input fifo to memory, this will also
+			 * trigger DMA RX completion
+			 */
+			dmaengine_terminate_all(dma->chan);
+		} else if (msm_port->is_uartdm) {
+			msm_handle_rx_dm(port, misr);
+		} else {
+			msm_handle_rx(port);
+		}
+	}
+	if (misr & MSM_UART_IMR_TXLEV)
+		msm_handle_tx(port);
+	if (misr & MSM_UART_IMR_DELTA_CTS)
+		msm_handle_delta_cts(port);
+
+	msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int msm_tx_empty(struct uart_port *port)
+{
+	return (msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int msm_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
+}
+
+static void msm_reset(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	unsigned int mr;
+
+	/* reset everything */
+	msm_write(port, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR);
+	msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR);
+	msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
+	msm_write(port, MSM_UART_CR_CMD_RESET_BREAK_INT, MSM_UART_CR);
+	msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR);
+	msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR);
+	mr = msm_read(port, MSM_UART_MR1);
+	mr &= ~MSM_UART_MR1_RX_RDY_CTL;
+	msm_write(port, mr, MSM_UART_MR1);
+
+	/* Disable DM modes */
+	if (msm_port->is_uartdm)
+		msm_write(port, 0, UARTDM_DMEN);
+}
+
+static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int mr;
+
+	mr = msm_read(port, MSM_UART_MR1);
+
+	if (!(mctrl & TIOCM_RTS)) {
+		mr &= ~MSM_UART_MR1_RX_RDY_CTL;
+		msm_write(port, mr, MSM_UART_MR1);
+		msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR);
+	} else {
+		mr |= MSM_UART_MR1_RX_RDY_CTL;
+		msm_write(port, mr, MSM_UART_MR1);
+	}
+}
+
+static void msm_break_ctl(struct uart_port *port, int break_ctl)
+{
+	if (break_ctl)
+		msm_write(port, MSM_UART_CR_CMD_START_BREAK, MSM_UART_CR);
+	else
+		msm_write(port, MSM_UART_CR_CMD_STOP_BREAK, MSM_UART_CR);
+}
+
+struct msm_baud_map {
+	u16	divisor;
+	u8	code;
+	u8	rxstale;
+};
+
+static const struct msm_baud_map *
+msm_find_best_baud(struct uart_port *port, unsigned int baud,
+		   unsigned long *rate)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	unsigned int divisor, result;
+	unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX;
+	const struct msm_baud_map *entry, *end, *best;
+	static const struct msm_baud_map table[] = {
+		{    1, 0xff, 31 },
+		{    2, 0xee, 16 },
+		{    3, 0xdd,  8 },
+		{    4, 0xcc,  6 },
+		{    6, 0xbb,  6 },
+		{    8, 0xaa,  6 },
+		{   12, 0x99,  6 },
+		{   16, 0x88,  1 },
+		{   24, 0x77,  1 },
+		{   32, 0x66,  1 },
+		{   48, 0x55,  1 },
+		{   96, 0x44,  1 },
+		{  192, 0x33,  1 },
+		{  384, 0x22,  1 },
+		{  768, 0x11,  1 },
+		{ 1536, 0x00,  1 },
+	};
+
+	best = table; /* Default to smallest divider */
+	target = clk_round_rate(msm_port->clk, 16 * baud);
+	divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
+
+	end = table + ARRAY_SIZE(table);
+	entry = table;
+	while (entry < end) {
+		if (entry->divisor <= divisor) {
+			result = target / entry->divisor / 16;
+			diff = abs(result - baud);
+
+			/* Keep track of best entry */
+			if (diff < best_diff) {
+				best_diff = diff;
+				best = entry;
+				best_rate = target;
+			}
+
+			if (result == baud)
+				break;
+		} else if (entry->divisor > divisor) {
+			old = target;
+			target = clk_round_rate(msm_port->clk, old + 1);
+			/*
+			 * The rate didn't get any faster so we can't do
+			 * better at dividing it down
+			 */
+			if (target == old)
+				break;
+
+			/* Start the divisor search over at this new rate */
+			entry = table;
+			divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
+			continue;
+		}
+		entry++;
+	}
+
+	*rate = best_rate;
+	return best;
+}
+
+static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
+			     unsigned long *saved_flags)
+	__must_hold(&port->lock)
+{
+	unsigned int rxstale, watermark, mask;
+	struct msm_port *msm_port = to_msm_port(port);
+	const struct msm_baud_map *entry;
+	unsigned long flags, rate;
+
+	flags = *saved_flags;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	entry = msm_find_best_baud(port, baud, &rate);
+	clk_set_rate(msm_port->clk, rate);
+	baud = rate / 16 / entry->divisor;
+
+	spin_lock_irqsave(&port->lock, flags);
+	*saved_flags = flags;
+	port->uartclk = rate;
+
+	msm_write(port, entry->code, MSM_UART_CSR);
+
+	/* RX stale watermark */
+	rxstale = entry->rxstale;
+	watermark = MSM_UART_IPR_STALE_LSB & rxstale;
+	if (msm_port->is_uartdm) {
+		mask = MSM_UART_DM_IPR_STALE_TIMEOUT_MSB;
+	} else {
+		watermark |= MSM_UART_IPR_RXSTALE_LAST;
+		mask = MSM_UART_IPR_STALE_TIMEOUT_MSB;
+	}
+
+	watermark |= mask & (rxstale << 2);
+
+	msm_write(port, watermark, MSM_UART_IPR);
+
+	/* set RX watermark */
+	watermark = (port->fifosize * 3) / 4;
+	msm_write(port, watermark, MSM_UART_RFWR);
+
+	/* set TX watermark */
+	msm_write(port, 10, MSM_UART_TFWR);
+
+	msm_write(port, MSM_UART_CR_CMD_PROTECTION_EN, MSM_UART_CR);
+	msm_reset(port);
+
+	/* Enable RX and TX */
+	msm_write(port, MSM_UART_CR_TX_ENABLE | MSM_UART_CR_RX_ENABLE, MSM_UART_CR);
+
+	/* turn on RX and CTS interrupts */
+	msm_port->imr = MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE |
+			MSM_UART_IMR_CURRENT_CTS | MSM_UART_IMR_RXBREAK_START;
+
+	msm_write(port, msm_port->imr, MSM_UART_IMR);
+
+	if (msm_port->is_uartdm) {
+		msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
+		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
+		msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
+	}
+
+	return baud;
+}
+
+static void msm_init_clock(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+
+	clk_prepare_enable(msm_port->clk);
+	clk_prepare_enable(msm_port->pclk);
+	msm_serial_set_mnd_regs(port);
+}
+
+static int msm_startup(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	unsigned int data, rfr_level, mask;
+	int ret;
+
+	snprintf(msm_port->name, sizeof(msm_port->name),
+		 "msm_serial%d", port->line);
+
+	msm_init_clock(port);
+
+	if (likely(port->fifosize > 12))
+		rfr_level = port->fifosize - 12;
+	else
+		rfr_level = port->fifosize;
+
+	/* set automatic RFR level */
+	data = msm_read(port, MSM_UART_MR1);
+
+	if (msm_port->is_uartdm)
+		mask = MSM_UART_DM_MR1_AUTO_RFR_LEVEL1;
+	else
+		mask = MSM_UART_MR1_AUTO_RFR_LEVEL1;
+
+	data &= ~mask;
+	data &= ~MSM_UART_MR1_AUTO_RFR_LEVEL0;
+	data |= mask & (rfr_level << 2);
+	data |= MSM_UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
+	msm_write(port, data, MSM_UART_MR1);
+
+	if (msm_port->is_uartdm) {
+		msm_request_tx_dma(msm_port, msm_port->uart.mapbase);
+		msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
+	}
+
+	ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH,
+			  msm_port->name, port);
+	if (unlikely(ret))
+		goto err_irq;
+
+	return 0;
+
+err_irq:
+	if (msm_port->is_uartdm)
+		msm_release_dma(msm_port);
+
+	clk_disable_unprepare(msm_port->pclk);
+	clk_disable_unprepare(msm_port->clk);
+
+	return ret;
+}
+
+static void msm_shutdown(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+
+	msm_port->imr = 0;
+	msm_write(port, 0, MSM_UART_IMR); /* disable interrupts */
+
+	if (msm_port->is_uartdm)
+		msm_release_dma(msm_port);
+
+	clk_disable_unprepare(msm_port->clk);
+
+	free_irq(port->irq, port);
+}
+
+static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
+			    const struct ktermios *old)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	struct msm_dma *dma = &msm_port->rx_dma;
+	unsigned long flags;
+	unsigned int baud, mr;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (dma->chan) /* Terminate if any */
+		msm_stop_dma(port, dma);
+
+	/* calculate and set baud rate */
+	baud = uart_get_baud_rate(port, termios, old, 300, 4000000);
+	baud = msm_set_baud_rate(port, baud, &flags);
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	/* calculate parity */
+	mr = msm_read(port, MSM_UART_MR2);
+	mr &= ~MSM_UART_MR2_PARITY_MODE;
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & PARODD)
+			mr |= MSM_UART_MR2_PARITY_MODE_ODD;
+		else if (termios->c_cflag & CMSPAR)
+			mr |= MSM_UART_MR2_PARITY_MODE_SPACE;
+		else
+			mr |= MSM_UART_MR2_PARITY_MODE_EVEN;
+	}
+
+	/* calculate bits per char */
+	mr &= ~MSM_UART_MR2_BITS_PER_CHAR;
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		mr |= MSM_UART_MR2_BITS_PER_CHAR_5;
+		break;
+	case CS6:
+		mr |= MSM_UART_MR2_BITS_PER_CHAR_6;
+		break;
+	case CS7:
+		mr |= MSM_UART_MR2_BITS_PER_CHAR_7;
+		break;
+	case CS8:
+	default:
+		mr |= MSM_UART_MR2_BITS_PER_CHAR_8;
+		break;
+	}
+
+	/* calculate stop bits */
+	mr &= ~(MSM_UART_MR2_STOP_BIT_LEN_ONE | MSM_UART_MR2_STOP_BIT_LEN_TWO);
+	if (termios->c_cflag & CSTOPB)
+		mr |= MSM_UART_MR2_STOP_BIT_LEN_TWO;
+	else
+		mr |= MSM_UART_MR2_STOP_BIT_LEN_ONE;
+
+	/* set parity, bits per char, and stop bit */
+	msm_write(port, mr, MSM_UART_MR2);
+
+	/* calculate and set hardware flow control */
+	mr = msm_read(port, MSM_UART_MR1);
+	mr &= ~(MSM_UART_MR1_CTS_CTL | MSM_UART_MR1_RX_RDY_CTL);
+	if (termios->c_cflag & CRTSCTS) {
+		mr |= MSM_UART_MR1_CTS_CTL;
+		mr |= MSM_UART_MR1_RX_RDY_CTL;
+	}
+	msm_write(port, mr, MSM_UART_MR1);
+
+	/* Configure status bits to ignore based on termio flags. */
+	port->read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= MSM_UART_SR_PAR_FRAME_ERR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= MSM_UART_SR_RX_BREAK;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* Try to use DMA */
+	msm_start_rx_dma(msm_port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *msm_type(struct uart_port *port)
+{
+	return "MSM";
+}
+
+static void msm_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *uart_resource;
+	resource_size_t size;
+
+	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!uart_resource))
+		return;
+	size = resource_size(uart_resource);
+
+	release_mem_region(port->mapbase, size);
+	iounmap(port->membase);
+	port->membase = NULL;
+}
+
+static int msm_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *uart_resource;
+	resource_size_t size;
+	int ret;
+
+	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!uart_resource))
+		return -ENXIO;
+
+	size = resource_size(uart_resource);
+
+	if (!request_mem_region(port->mapbase, size, "msm_serial"))
+		return -EBUSY;
+
+	port->membase = ioremap(port->mapbase, size);
+	if (!port->membase) {
+		ret = -EBUSY;
+		goto fail_release_port;
+	}
+
+	return 0;
+
+fail_release_port:
+	release_mem_region(port->mapbase, size);
+	return ret;
+}
+
+static void msm_config_port(struct uart_port *port, int flags)
+{
+	int ret;
+
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_MSM;
+		ret = msm_request_port(port);
+		if (ret)
+			return;
+	}
+}
+
+static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
+		return -EINVAL;
+	if (unlikely(port->irq != ser->irq))
+		return -EINVAL;
+	return 0;
+}
+
+static void msm_power(struct uart_port *port, unsigned int state,
+		      unsigned int oldstate)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+
+	switch (state) {
+	case 0:
+		clk_prepare_enable(msm_port->clk);
+		clk_prepare_enable(msm_port->pclk);
+		break;
+	case 3:
+		clk_disable_unprepare(msm_port->clk);
+		clk_disable_unprepare(msm_port->pclk);
+		break;
+	default:
+		pr_err("msm_serial: Unknown PM state %d\n", state);
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int msm_poll_get_char_single(struct uart_port *port)
+{
+	struct msm_port *msm_port = to_msm_port(port);
+	unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : MSM_UART_RF;
+
+	if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY))
+		return NO_POLL_CHAR;
+
+	return msm_read(port, rf_reg) & 0xff;
+}
+
+static int msm_poll_get_char_dm(struct uart_port *port)
+{
+	int c;
+	static u32 slop;
+	static int count;
+	unsigned char *sp = (unsigned char *)&slop;
+
+	/* Check if a previous read had more than one char */
+	if (count) {
+		c = sp[sizeof(slop) - count];
+		count--;
+	/* Or if FIFO is empty */
+	} else if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) {
+		/*
+		 * If RX packing buffer has less than a word, force stale to
+		 * push contents into RX FIFO
+		 */
+		count = msm_read(port, UARTDM_RXFS);
+		count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
+		if (count) {
+			msm_write(port, MSM_UART_CR_CMD_FORCE_STALE, MSM_UART_CR);
+			slop = msm_read(port, UARTDM_RF);
+			c = sp[0];
+			count--;
+			msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
+			msm_write(port, 0xFFFFFF, UARTDM_DMRX);
+			msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
+		} else {
+			c = NO_POLL_CHAR;
+		}
+	/* FIFO has a word */
+	} else {
+		slop = msm_read(port, UARTDM_RF);
+		c = sp[0];
+		count = sizeof(slop) - 1;
+	}
+
+	return c;
+}
+
+static int msm_poll_get_char(struct uart_port *port)
+{
+	u32 imr;
+	int c;
+	struct msm_port *msm_port = to_msm_port(port);
+
+	/* Disable all interrupts */
+	imr = msm_read(port, MSM_UART_IMR);
+	msm_write(port, 0, MSM_UART_IMR);
+
+	if (msm_port->is_uartdm)
+		c = msm_poll_get_char_dm(port);
+	else
+		c = msm_poll_get_char_single(port);
+
+	/* Enable interrupts */
+	msm_write(port, imr, MSM_UART_IMR);
+
+	return c;
+}
+
+static void msm_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	u32 imr;
+	struct msm_port *msm_port = to_msm_port(port);
+
+	/* Disable all interrupts */
+	imr = msm_read(port, MSM_UART_IMR);
+	msm_write(port, 0, MSM_UART_IMR);
+
+	if (msm_port->is_uartdm)
+		msm_reset_dm_count(port, 1);
+
+	/* Wait until FIFO is empty */
+	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
+		cpu_relax();
+
+	/* Write a character */
+	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : MSM_UART_TF);
+
+	/* Wait until FIFO is empty */
+	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
+		cpu_relax();
+
+	/* Enable interrupts */
+	msm_write(port, imr, MSM_UART_IMR);
+}
+#endif
+
+static const struct uart_ops msm_uart_pops = {
+	.tx_empty = msm_tx_empty,
+	.set_mctrl = msm_set_mctrl,
+	.get_mctrl = msm_get_mctrl,
+	.stop_tx = msm_stop_tx,
+	.start_tx = msm_start_tx,
+	.stop_rx = msm_stop_rx,
+	.enable_ms = msm_enable_ms,
+	.break_ctl = msm_break_ctl,
+	.startup = msm_startup,
+	.shutdown = msm_shutdown,
+	.set_termios = msm_set_termios,
+	.type = msm_type,
+	.release_port = msm_release_port,
+	.request_port = msm_request_port,
+	.config_port = msm_config_port,
+	.verify_port = msm_verify_port,
+	.pm = msm_power,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= msm_poll_get_char,
+	.poll_put_char	= msm_poll_put_char,
+#endif
+};
+
+static struct msm_port msm_uart_ports[] = {
+	{
+		.uart = {
+			.iotype = UPIO_MEM,
+			.ops = &msm_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.fifosize = 64,
+			.line = 0,
+		},
+	},
+	{
+		.uart = {
+			.iotype = UPIO_MEM,
+			.ops = &msm_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.fifosize = 64,
+			.line = 1,
+		},
+	},
+	{
+		.uart = {
+			.iotype = UPIO_MEM,
+			.ops = &msm_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.fifosize = 64,
+			.line = 2,
+		},
+	},
+};
+
+#define MSM_UART_NR	ARRAY_SIZE(msm_uart_ports)
+
+static inline struct uart_port *msm_get_port_from_line(unsigned int line)
+{
+	return &msm_uart_ports[line].uart;
+}
+
+#ifdef CONFIG_SERIAL_MSM_CONSOLE
+static void __msm_console_write(struct uart_port *port, const char *s,
+				unsigned int count, bool is_uartdm)
+{
+	unsigned long flags;
+	int i;
+	int num_newlines = 0;
+	bool replaced = false;
+	void __iomem *tf;
+	int locked = 1;
+
+	if (is_uartdm)
+		tf = port->membase + UARTDM_TF;
+	else
+		tf = port->membase + MSM_UART_TF;
+
+	/* Account for newlines that will get a carriage return added */
+	for (i = 0; i < count; i++)
+		if (s[i] == '\n')
+			num_newlines++;
+	count += num_newlines;
+
+	local_irq_save(flags);
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&port->lock);
+	else
+		spin_lock(&port->lock);
+
+	if (is_uartdm)
+		msm_reset_dm_count(port, count);
+
+	i = 0;
+	while (i < count) {
+		int j;
+		unsigned int num_chars;
+		char buf[4] = { 0 };
+
+		if (is_uartdm)
+			num_chars = min(count - i, (unsigned int)sizeof(buf));
+		else
+			num_chars = 1;
+
+		for (j = 0; j < num_chars; j++) {
+			char c = *s;
+
+			if (c == '\n' && !replaced) {
+				buf[j] = '\r';
+				j++;
+				replaced = true;
+			}
+			if (j < num_chars) {
+				buf[j] = c;
+				s++;
+				replaced = false;
+			}
+		}
+
+		while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
+			cpu_relax();
+
+		iowrite32_rep(tf, buf, 1);
+		i += num_chars;
+	}
+
+	if (locked)
+		spin_unlock(&port->lock);
+
+	local_irq_restore(flags);
+}
+
+static void msm_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	struct uart_port *port;
+	struct msm_port *msm_port;
+
+	BUG_ON(co->index < 0 || co->index >= MSM_UART_NR);
+
+	port = msm_get_port_from_line(co->index);
+	msm_port = to_msm_port(port);
+
+	__msm_console_write(port, s, count, msm_port->is_uartdm);
+}
+
+static int msm_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (unlikely(co->index >= MSM_UART_NR || co->index < 0))
+		return -ENXIO;
+
+	port = msm_get_port_from_line(co->index);
+
+	if (unlikely(!port->membase))
+		return -ENXIO;
+
+	msm_init_clock(port);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	pr_info("msm_serial: console setup on port #%d\n", port->line);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static void
+msm_serial_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	__msm_console_write(&dev->port, s, n, false);
+}
+
+static int __init
+msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = msm_serial_early_write;
+	return 0;
+}
+OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
+		    msm_serial_early_console_setup);
+
+static void
+msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	__msm_console_write(&dev->port, s, n, true);
+}
+
+static int __init
+msm_serial_early_console_setup_dm(struct earlycon_device *device,
+				  const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = msm_serial_early_write_dm;
+	return 0;
+}
+OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
+		    msm_serial_early_console_setup_dm);
+
+static struct uart_driver msm_uart_driver;
+
+static struct console msm_console = {
+	.name = "ttyMSM",
+	.write = msm_console_write,
+	.device = uart_console_device,
+	.setup = msm_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &msm_uart_driver,
+};
+
+#define MSM_CONSOLE	(&msm_console)
+
+#else
+#define MSM_CONSOLE	NULL
+#endif
+
+static struct uart_driver msm_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "msm_serial",
+	.dev_name = "ttyMSM",
+	.nr = MSM_UART_NR,
+	.cons = MSM_CONSOLE,
+};
+
+static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
+
+static const struct of_device_id msm_uartdm_table[] = {
+	{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
+	{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
+	{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
+	{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
+	{ }
+};
+
+static int msm_serial_probe(struct platform_device *pdev)
+{
+	struct msm_port *msm_port;
+	struct resource *resource;
+	struct uart_port *port;
+	const struct of_device_id *id;
+	int irq, line;
+
+	if (pdev->dev.of_node)
+		line = of_alias_get_id(pdev->dev.of_node, "serial");
+	else
+		line = pdev->id;
+
+	if (line < 0)
+		line = atomic_inc_return(&msm_uart_next_id) - 1;
+
+	if (unlikely(line < 0 || line >= MSM_UART_NR))
+		return -ENXIO;
+
+	dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
+
+	port = msm_get_port_from_line(line);
+	port->dev = &pdev->dev;
+	msm_port = to_msm_port(port);
+
+	id = of_match_device(msm_uartdm_table, &pdev->dev);
+	if (id)
+		msm_port->is_uartdm = (unsigned long)id->data;
+	else
+		msm_port->is_uartdm = 0;
+
+	msm_port->clk = devm_clk_get(&pdev->dev, "core");
+	if (IS_ERR(msm_port->clk))
+		return PTR_ERR(msm_port->clk);
+
+	if (msm_port->is_uartdm) {
+		msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
+		if (IS_ERR(msm_port->pclk))
+			return PTR_ERR(msm_port->pclk);
+	}
+
+	port->uartclk = clk_get_rate(msm_port->clk);
+	dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
+
+	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!resource))
+		return -ENXIO;
+	port->mapbase = resource->start;
+
+	irq = platform_get_irq(pdev, 0);
+	if (unlikely(irq < 0))
+		return -ENXIO;
+	port->irq = irq;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MSM_CONSOLE);
+
+	platform_set_drvdata(pdev, port);
+
+	return uart_add_one_port(&msm_uart_driver, port);
+}
+
+static int msm_serial_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&msm_uart_driver, port);
+
+	return 0;
+}
+
+static const struct of_device_id msm_match_table[] = {
+	{ .compatible = "qcom,msm-uart" },
+	{ .compatible = "qcom,msm-uartdm" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, msm_match_table);
+
+static int __maybe_unused msm_serial_suspend(struct device *dev)
+{
+	struct msm_port *port = dev_get_drvdata(dev);
+
+	uart_suspend_port(&msm_uart_driver, &port->uart);
+
+	return 0;
+}
+
+static int __maybe_unused msm_serial_resume(struct device *dev)
+{
+	struct msm_port *port = dev_get_drvdata(dev);
+
+	uart_resume_port(&msm_uart_driver, &port->uart);
+
+	return 0;
+}
+
+static const struct dev_pm_ops msm_serial_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
+};
+
+static struct platform_driver msm_platform_driver = {
+	.remove = msm_serial_remove,
+	.probe = msm_serial_probe,
+	.driver = {
+		.name = "msm_serial",
+		.pm = &msm_serial_dev_pm_ops,
+		.of_match_table = msm_match_table,
+	},
+};
+
+static int __init msm_serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&msm_uart_driver);
+	if (unlikely(ret))
+		return ret;
+
+	ret = platform_driver_register(&msm_platform_driver);
+	if (unlikely(ret))
+		uart_unregister_driver(&msm_uart_driver);
+
+	pr_info("msm_serial: driver initialized\n");
+
+	return ret;
+}
+
+static void __exit msm_serial_exit(void)
+{
+	platform_driver_unregister(&msm_platform_driver);
+	uart_unregister_driver(&msm_uart_driver);
+}
+
+module_init(msm_serial_init);
+module_exit(msm_serial_exit);
+
+MODULE_AUTHOR("Robert Love <rlove@google.com>");
+MODULE_DESCRIPTION("Driver for msm7x serial device");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/mux.c b/drivers/tty/serial/mux.c
new file mode 100644
index 000000000..85ce1e9af
--- /dev/null
+++ b/drivers/tty/serial/mux.c
@@ -0,0 +1,583 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+** mux.c:
+**	serial driver for the Mux console found in some PA-RISC servers.
+**
+**	(c) Copyright 2002 Ryan Bradetich
+**	(c) Copyright 2002 Hewlett-Packard Company
+**
+** This Driver currently only supports the console (port 0) on the MUX.
+** Additional work will be needed on this driver to enable the full
+** functionality of the MUX.
+**
+*/
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/console.h>
+#include <linux/delay.h> /* for udelay */
+#include <linux/device.h>
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <asm/parisc-device.h>
+
+#include <linux/sysrq.h>
+#include <linux/serial_core.h>
+
+#define MUX_OFFSET 0x800
+#define MUX_LINE_OFFSET 0x80
+
+#define MUX_FIFO_SIZE 255
+#define MUX_POLL_DELAY (30 * HZ / 1000)
+
+#define IO_DATA_REG_OFFSET 0x3c
+#define IO_DCOUNT_REG_OFFSET 0x40
+
+#define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
+#define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
+#define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
+
+#define MUX_NR 256
+static unsigned int port_cnt __read_mostly;
+struct mux_port {
+	struct uart_port port;
+	int enabled;
+};
+static struct mux_port mux_ports[MUX_NR];
+
+static struct uart_driver mux_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "ttyB",
+	.dev_name = "ttyB",
+	.major = MUX_MAJOR,
+	.minor = 0,
+	.nr = MUX_NR,
+};
+
+static struct timer_list mux_timer;
+
+#define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET)
+#define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET)
+
+/**
+ * get_mux_port_count - Get the number of available ports on the Mux.
+ * @dev: The parisc device.
+ *
+ * This function is used to determine the number of ports the Mux
+ * supports.  The IODC data reports the number of ports the Mux
+ * can support, but there are cases where not all the Mux ports
+ * are connected.  This function can override the IODC and
+ * return the true port count.
+ */
+static int __init get_mux_port_count(struct parisc_device *dev)
+{
+	int status;
+	u8 iodc_data[32];
+	unsigned long bytecnt;
+
+	/* If this is the built-in Mux for the K-Class (Eole CAP/MUX),
+	 * we only need to allocate resources for 1 port since the
+	 * other 7 ports are not connected.
+	 */
+	if(dev->id.hversion == 0x15)
+		return 1;
+
+	status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
+	BUG_ON(status != PDC_OK);
+
+	/* Return the number of ports specified in the iodc data. */
+	return ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8;
+}
+
+/**
+ * mux_tx_empty - Check if the transmitter fifo is empty.
+ * @port: Ptr to the uart_port.
+ *
+ * This function test if the transmitter fifo for the port
+ * described by 'port' is empty.  If it is empty, this function
+ * should return TIOCSER_TEMT, otherwise return 0.
+ */
+static unsigned int mux_tx_empty(struct uart_port *port)
+{
+	return UART_GET_FIFO_CNT(port) ? 0 : TIOCSER_TEMT;
+} 
+
+/**
+ * mux_set_mctrl - Set the current state of the modem control inputs.
+ * @ports: Ptr to the uart_port.
+ * @mctrl: Modem control bits.
+ *
+ * The Serial MUX does not support CTS, DCD or DSR so this function
+ * is ignored.
+ */
+static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+/**
+ * mux_get_mctrl - Returns the current state of modem control inputs.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial MUX does not support CTS, DCD or DSR so these lines are
+ * treated as permanently active.
+ */
+static unsigned int mux_get_mctrl(struct uart_port *port)
+{ 
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/**
+ * mux_stop_tx - Stop transmitting characters.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial MUX does not support this function.
+ */
+static void mux_stop_tx(struct uart_port *port)
+{
+}
+
+/**
+ * mux_start_tx - Start transmitting characters.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_start_tx(struct uart_port *port)
+{
+}
+
+/**
+ * mux_stop_rx - Stop receiving characters.
+ * @port: Ptr to the uart_port.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_stop_rx(struct uart_port *port)
+{
+}
+
+/**
+ * mux_break_ctl - Control the transmitssion of a break signal.
+ * @port: Ptr to the uart_port.
+ * @break_state: Raise/Lower the break signal.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void mux_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static void mux_tx_done(struct uart_port *port)
+{
+	/* FIXME js: really needs to wait? */
+	while (UART_GET_FIFO_CNT(port))
+		udelay(1);
+}
+
+/**
+ * mux_write - Write chars to the mux fifo.
+ * @port: Ptr to the uart_port.
+ *
+ * This function writes all the data from the uart buffer to
+ * the mux fifo.
+ */
+static void mux_write(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx_limited(port, ch,
+		port->fifosize - UART_GET_FIFO_CNT(port),
+		true,
+		UART_PUT_CHAR(port, ch),
+		mux_tx_done(port));
+}
+
+/**
+ * mux_read - Read chars from the mux fifo.
+ * @port: Ptr to the uart_port.
+ *
+ * This reads all available data from the mux's fifo and pushes
+ * the data to the tty layer.
+ */
+static void mux_read(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	int data;
+	__u32 start_count = port->icount.rx;
+
+	while(1) {
+		data = __raw_readl(port->membase + IO_DATA_REG_OFFSET);
+
+		if (MUX_STATUS(data))
+			continue;
+
+		if (MUX_EOFIFO(data))
+			break;
+
+		port->icount.rx++;
+
+		if (MUX_BREAK(data)) {
+			port->icount.brk++;
+			if(uart_handle_break(port))
+				continue;
+		}
+
+		if (uart_handle_sysrq_char(port, data & 0xffu))
+			continue;
+
+		tty_insert_flip_char(tport, data & 0xFF, TTY_NORMAL);
+	}
+	
+	if (start_count != port->icount.rx)
+		tty_flip_buffer_push(tport);
+}
+
+/**
+ * mux_startup - Initialize the port.
+ * @port: Ptr to the uart_port.
+ *
+ * Grab any resources needed for this port and start the
+ * mux timer.
+ */
+static int mux_startup(struct uart_port *port)
+{
+	mux_ports[port->line].enabled = 1;
+	return 0;
+}
+
+/**
+ * mux_shutdown - Disable the port.
+ * @port: Ptr to the uart_port.
+ *
+ * Release any resources needed for the port.
+ */
+static void mux_shutdown(struct uart_port *port)
+{
+	mux_ports[port->line].enabled = 0;
+}
+
+/**
+ * mux_set_termios - Chane port parameters.
+ * @port: Ptr to the uart_port.
+ * @termios: new termios settings.
+ * @old: old termios settings.
+ *
+ * The Serial Mux does not support this function.
+ */
+static void
+mux_set_termios(struct uart_port *port, struct ktermios *termios,
+	        const struct ktermios *old)
+{
+}
+
+/**
+ * mux_type - Describe the port.
+ * @port: Ptr to the uart_port.
+ *
+ * Return a pointer to a string constant describing the
+ * specified port.
+ */
+static const char *mux_type(struct uart_port *port)
+{
+	return "Mux";
+}
+
+/**
+ * mux_release_port - Release memory and IO regions.
+ * @port: Ptr to the uart_port.
+ * 
+ * Release any memory and IO region resources currently in use by
+ * the port.
+ */
+static void mux_release_port(struct uart_port *port)
+{
+}
+
+/**
+ * mux_request_port - Request memory and IO regions.
+ * @port: Ptr to the uart_port.
+ *
+ * Request any memory and IO region resources required by the port.
+ * If any fail, no resources should be registered when this function
+ * returns, and it should return -EBUSY on failure.
+ */
+static int mux_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/**
+ * mux_config_port - Perform port autoconfiguration.
+ * @port: Ptr to the uart_port.
+ * @type: Bitmask of required configurations.
+ *
+ * Perform any autoconfiguration steps for the port.  This function is
+ * called if the UPF_BOOT_AUTOCONF flag is specified for the port.
+ * [Note: This is required for now because of a bug in the Serial core.
+ *  rmk has already submitted a patch to linus, should be available for
+ *  2.5.47.]
+ */
+static void mux_config_port(struct uart_port *port, int type)
+{
+	port->type = PORT_MUX;
+}
+
+/**
+ * mux_verify_port - Verify the port information.
+ * @port: Ptr to the uart_port.
+ * @ser: Ptr to the serial information.
+ *
+ * Verify the new serial port information contained within serinfo is
+ * suitable for this port type.
+ */
+static int mux_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if(port->membase == NULL)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * mux_drv_poll - Mux poll function.
+ * @unused: Unused variable
+ *
+ * This function periodically polls the Serial MUX to check for new data.
+ */
+static void mux_poll(struct timer_list *unused)
+{  
+	int i;
+
+	for(i = 0; i < port_cnt; ++i) {
+		if(!mux_ports[i].enabled)
+			continue;
+
+		mux_read(&mux_ports[i].port);
+		mux_write(&mux_ports[i].port);
+	}
+
+	mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
+}
+
+
+#ifdef CONFIG_SERIAL_MUX_CONSOLE
+static void mux_console_write(struct console *co, const char *s, unsigned count)
+{
+	/* Wait until the FIFO drains. */
+	while(UART_GET_FIFO_CNT(&mux_ports[0].port))
+		udelay(1);
+
+	while(count--) {
+		if(*s == '\n') {
+			UART_PUT_CHAR(&mux_ports[0].port, '\r');
+		}
+		UART_PUT_CHAR(&mux_ports[0].port, *s++);
+	}
+
+}
+
+static int mux_console_setup(struct console *co, char *options)
+{
+        return 0;
+}
+
+static struct console mux_console = {
+	.name =		"ttyB",
+	.write =	mux_console_write,
+	.device =	uart_console_device,
+	.setup =	mux_console_setup,
+	.flags =	CON_ENABLED | CON_PRINTBUFFER,
+	.index =	0,
+	.data =		&mux_driver,
+};
+
+#define MUX_CONSOLE	&mux_console
+#else
+#define MUX_CONSOLE	NULL
+#endif
+
+static const struct uart_ops mux_pops = {
+	.tx_empty =		mux_tx_empty,
+	.set_mctrl =		mux_set_mctrl,
+	.get_mctrl =		mux_get_mctrl,
+	.stop_tx =		mux_stop_tx,
+	.start_tx =		mux_start_tx,
+	.stop_rx =		mux_stop_rx,
+	.break_ctl =		mux_break_ctl,
+	.startup =		mux_startup,
+	.shutdown =		mux_shutdown,
+	.set_termios =		mux_set_termios,
+	.type =			mux_type,
+	.release_port =		mux_release_port,
+	.request_port =		mux_request_port,
+	.config_port =		mux_config_port,
+	.verify_port =		mux_verify_port,
+};
+
+/**
+ * mux_probe - Determine if the Serial Mux should claim this device.
+ * @dev: The parisc device.
+ *
+ * Deterimine if the Serial Mux should claim this chip (return 0)
+ * or not (return 1).
+ */
+static int __init mux_probe(struct parisc_device *dev)
+{
+	int i, status;
+
+	int port_count = get_mux_port_count(dev);
+	printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.6\n", port_count);
+
+	dev_set_drvdata(&dev->dev, (void *)(long)port_count);
+	request_mem_region(dev->hpa.start + MUX_OFFSET,
+                           port_count * MUX_LINE_OFFSET, "Mux");
+
+	if(!port_cnt) {
+		mux_driver.cons = MUX_CONSOLE;
+
+		status = uart_register_driver(&mux_driver);
+		if(status) {
+			printk(KERN_ERR "Serial mux: Unable to register driver.\n");
+			return 1;
+		}
+	}
+
+	for(i = 0; i < port_count; ++i, ++port_cnt) {
+		struct uart_port *port = &mux_ports[port_cnt].port;
+		port->iobase	= 0;
+		port->mapbase	= dev->hpa.start + MUX_OFFSET +
+						(i * MUX_LINE_OFFSET);
+		port->membase	= ioremap(port->mapbase, MUX_LINE_OFFSET);
+		port->iotype	= UPIO_MEM;
+		port->type	= PORT_MUX;
+		port->irq	= 0;
+		port->uartclk	= 0;
+		port->fifosize	= MUX_FIFO_SIZE;
+		port->ops	= &mux_pops;
+		port->flags	= UPF_BOOT_AUTOCONF;
+		port->line	= port_cnt;
+		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MUX_CONSOLE);
+
+		spin_lock_init(&port->lock);
+
+		status = uart_add_one_port(&mux_driver, port);
+		BUG_ON(status);
+	}
+
+	return 0;
+}
+
+static void __exit mux_remove(struct parisc_device *dev)
+{
+	int i, j;
+	int port_count = (long)dev_get_drvdata(&dev->dev);
+
+	/* Find Port 0 for this card in the mux_ports list. */
+	for(i = 0; i < port_cnt; ++i) {
+		if(mux_ports[i].port.mapbase == dev->hpa.start + MUX_OFFSET)
+			break;
+	}
+	BUG_ON(i + port_count > port_cnt);
+
+	/* Release the resources associated with each port on the device. */
+	for(j = 0; j < port_count; ++j, ++i) {
+		struct uart_port *port = &mux_ports[i].port;
+
+		uart_remove_one_port(&mux_driver, port);
+		if(port->membase)
+			iounmap(port->membase);
+	}
+
+	release_mem_region(dev->hpa.start + MUX_OFFSET, port_count * MUX_LINE_OFFSET);
+}
+
+/* Hack.  This idea was taken from the 8250_gsc.c on how to properly order
+ * the serial port detection in the proper order.   The idea is we always
+ * want the builtin mux to be detected before addin mux cards, so we
+ * specifically probe for the builtin mux cards first.
+ *
+ * This table only contains the parisc_device_id of known builtin mux
+ * devices.  All other mux cards will be detected by the generic mux_tbl.
+ */
+static const struct parisc_device_id builtin_mux_tbl[] __initconst = {
+	{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, 0x15, 0x0000D }, /* All K-class */
+	{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, 0x44, 0x0000D }, /* E35, E45, and E55 */
+	{ 0, }
+};
+
+static const struct parisc_device_id mux_tbl[] __initconst = {
+	{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(parisc, builtin_mux_tbl);
+MODULE_DEVICE_TABLE(parisc, mux_tbl);
+
+static struct parisc_driver builtin_serial_mux_driver __refdata = {
+	.name =		"builtin_serial_mux",
+	.id_table =	builtin_mux_tbl,
+	.probe =	mux_probe,
+	.remove =       __exit_p(mux_remove),
+};
+
+static struct parisc_driver serial_mux_driver __refdata = {
+	.name =		"serial_mux",
+	.id_table =	mux_tbl,
+	.probe =	mux_probe,
+	.remove =       __exit_p(mux_remove),
+};
+
+/**
+ * mux_init - Serial MUX initialization procedure.
+ *
+ * Register the Serial MUX driver.
+ */
+static int __init mux_init(void)
+{
+	register_parisc_driver(&builtin_serial_mux_driver);
+	register_parisc_driver(&serial_mux_driver);
+
+	if(port_cnt > 0) {
+		/* Start the Mux timer */
+		timer_setup(&mux_timer, mux_poll, 0);
+		mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
+
+#ifdef CONFIG_SERIAL_MUX_CONSOLE
+	        register_console(&mux_console);
+#endif
+	}
+
+	return 0;
+}
+
+/**
+ * mux_exit - Serial MUX cleanup procedure.
+ *
+ * Unregister the Serial MUX driver from the tty layer.
+ */
+static void __exit mux_exit(void)
+{
+	/* Delete the Mux timer. */
+	if(port_cnt > 0) {
+		del_timer_sync(&mux_timer);
+#ifdef CONFIG_SERIAL_MUX_CONSOLE
+		unregister_console(&mux_console);
+#endif
+	}
+
+	unregister_parisc_driver(&builtin_serial_mux_driver);
+	unregister_parisc_driver(&serial_mux_driver);
+	uart_unregister_driver(&mux_driver);
+}
+
+module_init(mux_init);
+module_exit(mux_exit);
+
+MODULE_AUTHOR("Ryan Bradetich");
+MODULE_DESCRIPTION("Serial MUX driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR);
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
new file mode 100644
index 000000000..ea924e9b9
--- /dev/null
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -0,0 +1,1531 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+* ***************************************************************************
+* Marvell Armada-3700 Serial Driver
+* Author: Wilson Ding <dingwei@marvell.com>
+* Copyright (C) 2015 Marvell International Ltd.
+* ***************************************************************************
+*/
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/math64.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/* Register Map */
+#define UART_STD_RBR		0x00
+#define UART_EXT_RBR		0x18
+
+#define UART_STD_TSH		0x04
+#define UART_EXT_TSH		0x1C
+
+#define UART_STD_CTRL1		0x08
+#define UART_EXT_CTRL1		0x04
+#define  CTRL_SOFT_RST		BIT(31)
+#define  CTRL_TXFIFO_RST	BIT(15)
+#define  CTRL_RXFIFO_RST	BIT(14)
+#define  CTRL_SND_BRK_SEQ	BIT(11)
+#define  CTRL_BRK_DET_INT	BIT(3)
+#define  CTRL_FRM_ERR_INT	BIT(2)
+#define  CTRL_PAR_ERR_INT	BIT(1)
+#define  CTRL_OVR_ERR_INT	BIT(0)
+#define  CTRL_BRK_INT		(CTRL_BRK_DET_INT | CTRL_FRM_ERR_INT | \
+				CTRL_PAR_ERR_INT | CTRL_OVR_ERR_INT)
+
+#define UART_STD_CTRL2		UART_STD_CTRL1
+#define UART_EXT_CTRL2		0x20
+#define  CTRL_STD_TX_RDY_INT	BIT(5)
+#define  CTRL_EXT_TX_RDY_INT	BIT(6)
+#define  CTRL_STD_RX_RDY_INT	BIT(4)
+#define  CTRL_EXT_RX_RDY_INT	BIT(5)
+
+#define UART_STAT		0x0C
+#define  STAT_TX_FIFO_EMP	BIT(13)
+#define  STAT_TX_FIFO_FUL	BIT(11)
+#define  STAT_TX_EMP		BIT(6)
+#define  STAT_STD_TX_RDY	BIT(5)
+#define  STAT_EXT_TX_RDY	BIT(15)
+#define  STAT_STD_RX_RDY	BIT(4)
+#define  STAT_EXT_RX_RDY	BIT(14)
+#define  STAT_BRK_DET		BIT(3)
+#define  STAT_FRM_ERR		BIT(2)
+#define  STAT_PAR_ERR		BIT(1)
+#define  STAT_OVR_ERR		BIT(0)
+#define  STAT_BRK_ERR		(STAT_BRK_DET | STAT_FRM_ERR \
+				 | STAT_PAR_ERR | STAT_OVR_ERR)
+
+/*
+ * Marvell Armada 3700 Functional Specifications describes that bit 21 of UART
+ * Clock Control register controls UART1 and bit 20 controls UART2. But in
+ * reality bit 21 controls UART2 and bit 20 controls UART1. This seems to be an
+ * error in Marvell's documentation. Hence following CLK_DIS macros are swapped.
+ */
+
+#define UART_BRDV		0x10
+/* These bits are located in UART1 address space and control UART2 */
+#define  UART2_CLK_DIS		BIT(21)
+/* These bits are located in UART1 address space and control UART1 */
+#define  UART1_CLK_DIS		BIT(20)
+/* These bits are located in UART1 address space and control both UARTs */
+#define  CLK_NO_XTAL		BIT(19)
+#define  CLK_TBG_DIV1_SHIFT	15
+#define  CLK_TBG_DIV1_MASK	0x7
+#define  CLK_TBG_DIV1_MAX	6
+#define  CLK_TBG_DIV2_SHIFT	12
+#define  CLK_TBG_DIV2_MASK	0x7
+#define  CLK_TBG_DIV2_MAX	6
+#define  CLK_TBG_SEL_SHIFT	10
+#define  CLK_TBG_SEL_MASK	0x3
+/* These bits are located in both UARTs address space */
+#define  BRDV_BAUD_MASK         0x3FF
+#define  BRDV_BAUD_MAX		BRDV_BAUD_MASK
+
+#define UART_OSAMP		0x14
+#define  OSAMP_DEFAULT_DIVISOR	16
+#define  OSAMP_DIVISORS_MASK	0x3F3F3F3F
+#define  OSAMP_MAX_DIVISOR	63
+
+#define MVEBU_NR_UARTS		2
+
+#define MVEBU_UART_TYPE		"mvebu-uart"
+#define DRIVER_NAME		"mvebu_serial"
+
+enum {
+	/* Either there is only one summed IRQ... */
+	UART_IRQ_SUM = 0,
+	/* ...or there are two separate IRQ for RX and TX */
+	UART_RX_IRQ = 0,
+	UART_TX_IRQ,
+	UART_IRQ_COUNT
+};
+
+/* Diverging register offsets */
+struct uart_regs_layout {
+	unsigned int rbr;
+	unsigned int tsh;
+	unsigned int ctrl;
+	unsigned int intr;
+};
+
+/* Diverging flags */
+struct uart_flags {
+	unsigned int ctrl_tx_rdy_int;
+	unsigned int ctrl_rx_rdy_int;
+	unsigned int stat_tx_rdy;
+	unsigned int stat_rx_rdy;
+};
+
+/* Driver data, a structure for each UART port */
+struct mvebu_uart_driver_data {
+	bool is_ext;
+	struct uart_regs_layout regs;
+	struct uart_flags flags;
+};
+
+/* Saved registers during suspend */
+struct mvebu_uart_pm_regs {
+	unsigned int rbr;
+	unsigned int tsh;
+	unsigned int ctrl;
+	unsigned int intr;
+	unsigned int stat;
+	unsigned int brdv;
+	unsigned int osamp;
+};
+
+/* MVEBU UART driver structure */
+struct mvebu_uart {
+	struct uart_port *port;
+	struct clk *clk;
+	int irq[UART_IRQ_COUNT];
+	struct mvebu_uart_driver_data *data;
+#if defined(CONFIG_PM)
+	struct mvebu_uart_pm_regs pm_regs;
+#endif /* CONFIG_PM */
+};
+
+static struct mvebu_uart *to_mvuart(struct uart_port *port)
+{
+	return (struct mvebu_uart *)port->private_data;
+}
+
+#define IS_EXTENDED(port) (to_mvuart(port)->data->is_ext)
+
+#define UART_RBR(port) (to_mvuart(port)->data->regs.rbr)
+#define UART_TSH(port) (to_mvuart(port)->data->regs.tsh)
+#define UART_CTRL(port) (to_mvuart(port)->data->regs.ctrl)
+#define UART_INTR(port) (to_mvuart(port)->data->regs.intr)
+
+#define CTRL_TX_RDY_INT(port) (to_mvuart(port)->data->flags.ctrl_tx_rdy_int)
+#define CTRL_RX_RDY_INT(port) (to_mvuart(port)->data->flags.ctrl_rx_rdy_int)
+#define STAT_TX_RDY(port) (to_mvuart(port)->data->flags.stat_tx_rdy)
+#define STAT_RX_RDY(port) (to_mvuart(port)->data->flags.stat_rx_rdy)
+
+static struct uart_port mvebu_uart_ports[MVEBU_NR_UARTS];
+
+static DEFINE_SPINLOCK(mvebu_uart_lock);
+
+/* Core UART Driver Operations */
+static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned int st;
+
+	spin_lock_irqsave(&port->lock, flags);
+	st = readl(port->membase + UART_STAT);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void mvebu_uart_set_mctrl(struct uart_port *port,
+				 unsigned int mctrl)
+{
+/*
+ * Even if we do not support configuring the modem control lines, this
+ * function must be proided to the serial core
+ */
+}
+
+static void mvebu_uart_stop_tx(struct uart_port *port)
+{
+	unsigned int ctl = readl(port->membase + UART_INTR(port));
+
+	ctl &= ~CTRL_TX_RDY_INT(port);
+	writel(ctl, port->membase + UART_INTR(port));
+}
+
+static void mvebu_uart_start_tx(struct uart_port *port)
+{
+	unsigned int ctl;
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (IS_EXTENDED(port) && !uart_circ_empty(xmit)) {
+		writel(xmit->buf[xmit->tail], port->membase + UART_TSH(port));
+		uart_xmit_advance(port, 1);
+	}
+
+	ctl = readl(port->membase + UART_INTR(port));
+	ctl |= CTRL_TX_RDY_INT(port);
+	writel(ctl, port->membase + UART_INTR(port));
+}
+
+static void mvebu_uart_stop_rx(struct uart_port *port)
+{
+	unsigned int ctl;
+
+	ctl = readl(port->membase + UART_CTRL(port));
+	ctl &= ~CTRL_BRK_INT;
+	writel(ctl, port->membase + UART_CTRL(port));
+
+	ctl = readl(port->membase + UART_INTR(port));
+	ctl &= ~CTRL_RX_RDY_INT(port);
+	writel(ctl, port->membase + UART_INTR(port));
+}
+
+static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
+{
+	unsigned int ctl;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	ctl = readl(port->membase + UART_CTRL(port));
+	if (brk == -1)
+		ctl |= CTRL_SND_BRK_SEQ;
+	else
+		ctl &= ~CTRL_SND_BRK_SEQ;
+	writel(ctl, port->membase + UART_CTRL(port));
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned char ch = 0;
+	char flag = 0;
+	int ret;
+
+	do {
+		if (status & STAT_RX_RDY(port)) {
+			ch = readl(port->membase + UART_RBR(port));
+			ch &= 0xff;
+			flag = TTY_NORMAL;
+			port->icount.rx++;
+
+			if (status & STAT_PAR_ERR)
+				port->icount.parity++;
+		}
+
+		/*
+		 * For UART2, error bits are not cleared on buffer read.
+		 * This causes interrupt loop and system hang.
+		 */
+		if (IS_EXTENDED(port) && (status & STAT_BRK_ERR)) {
+			ret = readl(port->membase + UART_STAT);
+			ret |= STAT_BRK_ERR;
+			writel(ret, port->membase + UART_STAT);
+		}
+
+		if (status & STAT_BRK_DET) {
+			port->icount.brk++;
+			status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
+			if (uart_handle_break(port))
+				goto ignore_char;
+		}
+
+		if (status & STAT_OVR_ERR)
+			port->icount.overrun++;
+
+		if (status & STAT_FRM_ERR)
+			port->icount.frame++;
+
+		if (uart_handle_sysrq_char(port, ch))
+			goto ignore_char;
+
+		if (status & port->ignore_status_mask & STAT_PAR_ERR)
+			status &= ~STAT_RX_RDY(port);
+
+		status &= port->read_status_mask;
+
+		if (status & STAT_PAR_ERR)
+			flag = TTY_PARITY;
+
+		status &= ~port->ignore_status_mask;
+
+		if (status & STAT_RX_RDY(port))
+			tty_insert_flip_char(tport, ch, flag);
+
+		if (status & STAT_BRK_DET)
+			tty_insert_flip_char(tport, 0, TTY_BREAK);
+
+		if (status & STAT_FRM_ERR)
+			tty_insert_flip_char(tport, 0, TTY_FRAME);
+
+		if (status & STAT_OVR_ERR)
+			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+
+ignore_char:
+		status = readl(port->membase + UART_STAT);
+	} while (status & (STAT_RX_RDY(port) | STAT_BRK_DET));
+
+	tty_flip_buffer_push(tport);
+}
+
+static void mvebu_uart_tx_chars(struct uart_port *port, unsigned int status)
+{
+	u8 ch;
+
+	uart_port_tx_limited(port, ch, port->fifosize,
+		!(readl(port->membase + UART_STAT) & STAT_TX_FIFO_FUL),
+		writel(ch, port->membase + UART_TSH(port)),
+		({}));
+}
+
+static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+	unsigned int st = readl(port->membase + UART_STAT);
+
+	if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
+		  STAT_BRK_DET))
+		mvebu_uart_rx_chars(port, st);
+
+	if (st & STAT_TX_RDY(port))
+		mvebu_uart_tx_chars(port, st);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mvebu_uart_rx_isr(int irq, void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+	unsigned int st = readl(port->membase + UART_STAT);
+
+	if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
+			STAT_BRK_DET))
+		mvebu_uart_rx_chars(port, st);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mvebu_uart_tx_isr(int irq, void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+	unsigned int st = readl(port->membase + UART_STAT);
+
+	if (st & STAT_TX_RDY(port))
+		mvebu_uart_tx_chars(port, st);
+
+	return IRQ_HANDLED;
+}
+
+static int mvebu_uart_startup(struct uart_port *port)
+{
+	struct mvebu_uart *mvuart = to_mvuart(port);
+	unsigned int ctl;
+	int ret;
+
+	writel(CTRL_TXFIFO_RST | CTRL_RXFIFO_RST,
+	       port->membase + UART_CTRL(port));
+	udelay(1);
+
+	/* Clear the error bits of state register before IRQ request */
+	ret = readl(port->membase + UART_STAT);
+	ret |= STAT_BRK_ERR;
+	writel(ret, port->membase + UART_STAT);
+
+	writel(CTRL_BRK_INT, port->membase + UART_CTRL(port));
+
+	ctl = readl(port->membase + UART_INTR(port));
+	ctl |= CTRL_RX_RDY_INT(port);
+	writel(ctl, port->membase + UART_INTR(port));
+
+	if (!mvuart->irq[UART_TX_IRQ]) {
+		/* Old bindings with just one interrupt (UART0 only) */
+		ret = devm_request_irq(port->dev, mvuart->irq[UART_IRQ_SUM],
+				       mvebu_uart_isr, port->irqflags,
+				       dev_name(port->dev), port);
+		if (ret) {
+			dev_err(port->dev, "unable to request IRQ %d\n",
+				mvuart->irq[UART_IRQ_SUM]);
+			return ret;
+		}
+	} else {
+		/* New bindings with an IRQ for RX and TX (both UART) */
+		ret = devm_request_irq(port->dev, mvuart->irq[UART_RX_IRQ],
+				       mvebu_uart_rx_isr, port->irqflags,
+				       dev_name(port->dev), port);
+		if (ret) {
+			dev_err(port->dev, "unable to request IRQ %d\n",
+				mvuart->irq[UART_RX_IRQ]);
+			return ret;
+		}
+
+		ret = devm_request_irq(port->dev, mvuart->irq[UART_TX_IRQ],
+				       mvebu_uart_tx_isr, port->irqflags,
+				       dev_name(port->dev),
+				       port);
+		if (ret) {
+			dev_err(port->dev, "unable to request IRQ %d\n",
+				mvuart->irq[UART_TX_IRQ]);
+			devm_free_irq(port->dev, mvuart->irq[UART_RX_IRQ],
+				      port);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void mvebu_uart_shutdown(struct uart_port *port)
+{
+	struct mvebu_uart *mvuart = to_mvuart(port);
+
+	writel(0, port->membase + UART_INTR(port));
+
+	if (!mvuart->irq[UART_TX_IRQ]) {
+		devm_free_irq(port->dev, mvuart->irq[UART_IRQ_SUM], port);
+	} else {
+		devm_free_irq(port->dev, mvuart->irq[UART_RX_IRQ], port);
+		devm_free_irq(port->dev, mvuart->irq[UART_TX_IRQ], port);
+	}
+}
+
+static unsigned int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
+{
+	unsigned int d_divisor, m_divisor;
+	unsigned long flags;
+	u32 brdv, osamp;
+
+	if (!port->uartclk)
+		return 0;
+
+	/*
+	 * The baudrate is derived from the UART clock thanks to divisors:
+	 *   > d1 * d2 ("TBG divisors"): can divide only TBG clock from 1 to 6
+	 *   > D ("baud generator"): can divide the clock from 1 to 1023
+	 *   > M ("fractional divisor"): allows a better accuracy (from 1 to 63)
+	 *
+	 * Exact formulas for calculating baudrate:
+	 *
+	 * with default x16 scheme:
+	 *   baudrate = xtal / (d * 16)
+	 *   baudrate = tbg / (d1 * d2 * d * 16)
+	 *
+	 * with fractional divisor:
+	 *   baudrate = 10 * xtal / (d * (3 * (m1 + m2) + 2 * (m3 + m4)))
+	 *   baudrate = 10 * tbg / (d1*d2 * d * (3 * (m1 + m2) + 2 * (m3 + m4)))
+	 *
+	 * Oversampling value:
+	 *   osamp = (m1 << 0) | (m2 << 8) | (m3 << 16) | (m4 << 24);
+	 *
+	 * Where m1 controls number of clock cycles per bit for bits 1,2,3;
+	 * m2 for bits 4,5,6; m3 for bits 7,8 and m4 for bits 9,10.
+	 *
+	 * To simplify baudrate setup set all the M prescalers to the same
+	 * value. For baudrates 9600 Bd and higher, it is enough to use the
+	 * default (x16) divisor or fractional divisor with M = 63, so there
+	 * is no need to use real fractional support (where the M prescalers
+	 * are not equal).
+	 *
+	 * When all the M prescalers are zeroed then default (x16) divisor is
+	 * used. Default x16 scheme is more stable than M (fractional divisor),
+	 * so use M only when D divisor is not enough to derive baudrate.
+	 *
+	 * Member port->uartclk is either xtal clock rate or TBG clock rate
+	 * divided by (d1 * d2). So d1 and d2 are already set by the UART clock
+	 * driver (and UART driver itself cannot change them). Moreover they are
+	 * shared between both UARTs.
+	 */
+
+	m_divisor = OSAMP_DEFAULT_DIVISOR;
+	d_divisor = DIV_ROUND_CLOSEST(port->uartclk, baud * m_divisor);
+
+	if (d_divisor > BRDV_BAUD_MAX) {
+		/*
+		 * Experiments show that small M divisors are unstable.
+		 * Use maximal possible M = 63 and calculate D divisor.
+		 */
+		m_divisor = OSAMP_MAX_DIVISOR;
+		d_divisor = DIV_ROUND_CLOSEST(port->uartclk, baud * m_divisor);
+	}
+
+	if (d_divisor < 1)
+		d_divisor = 1;
+	else if (d_divisor > BRDV_BAUD_MAX)
+		d_divisor = BRDV_BAUD_MAX;
+
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+	brdv = readl(port->membase + UART_BRDV);
+	brdv &= ~BRDV_BAUD_MASK;
+	brdv |= d_divisor;
+	writel(brdv, port->membase + UART_BRDV);
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+
+	osamp = readl(port->membase + UART_OSAMP);
+	osamp &= ~OSAMP_DIVISORS_MASK;
+	if (m_divisor != OSAMP_DEFAULT_DIVISOR)
+		osamp |= (m_divisor << 0) | (m_divisor << 8) |
+			(m_divisor << 16) | (m_divisor << 24);
+	writel(osamp, port->membase + UART_OSAMP);
+
+	return DIV_ROUND_CLOSEST(port->uartclk, d_divisor * m_divisor);
+}
+
+static void mvebu_uart_set_termios(struct uart_port *port,
+				   struct ktermios *termios,
+				   const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, min_baud, max_baud;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
+		STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
+
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= STAT_FRM_ERR | STAT_PAR_ERR;
+
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |=
+			STAT_FRM_ERR | STAT_PAR_ERR | STAT_OVR_ERR;
+
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= STAT_RX_RDY(port) | STAT_BRK_ERR;
+
+	/*
+	 * Maximal divisor is 1023 and maximal fractional divisor is 63. And
+	 * experiments show that baudrates above 1/80 of parent clock rate are
+	 * not stable. So disallow baudrates above 1/80 of the parent clock
+	 * rate. If port->uartclk is not available, then
+	 * mvebu_uart_baud_rate_set() fails, so values min_baud and max_baud
+	 * in this case do not matter.
+	 */
+	min_baud = DIV_ROUND_UP(port->uartclk, BRDV_BAUD_MAX *
+				OSAMP_MAX_DIVISOR);
+	max_baud = port->uartclk / 80;
+
+	baud = uart_get_baud_rate(port, termios, old, min_baud, max_baud);
+	baud = mvebu_uart_baud_rate_set(port, baud);
+
+	/* In case baudrate cannot be changed, report previous old value */
+	if (baud == 0 && old)
+		baud = tty_termios_baud_rate(old);
+
+	/* Only the following flag changes are supported */
+	if (old) {
+		termios->c_iflag &= INPCK | IGNPAR;
+		termios->c_iflag |= old->c_iflag & ~(INPCK | IGNPAR);
+		termios->c_cflag &= CREAD | CBAUD;
+		termios->c_cflag |= old->c_cflag & ~(CREAD | CBAUD);
+		termios->c_cflag |= CS8;
+	}
+
+	if (baud != 0) {
+		tty_termios_encode_baud_rate(termios, baud, baud);
+		uart_update_timeout(port, termios->c_cflag, baud);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *mvebu_uart_type(struct uart_port *port)
+{
+	return MVEBU_UART_TYPE;
+}
+
+static void mvebu_uart_release_port(struct uart_port *port)
+{
+	/* Nothing to do here */
+}
+
+static int mvebu_uart_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int mvebu_uart_get_poll_char(struct uart_port *port)
+{
+	unsigned int st = readl(port->membase + UART_STAT);
+
+	if (!(st & STAT_RX_RDY(port)))
+		return NO_POLL_CHAR;
+
+	return readl(port->membase + UART_RBR(port));
+}
+
+static void mvebu_uart_put_poll_char(struct uart_port *port, unsigned char c)
+{
+	unsigned int st;
+
+	for (;;) {
+		st = readl(port->membase + UART_STAT);
+
+		if (!(st & STAT_TX_FIFO_FUL))
+			break;
+
+		udelay(1);
+	}
+
+	writel(c, port->membase + UART_TSH(port));
+}
+#endif
+
+static const struct uart_ops mvebu_uart_ops = {
+	.tx_empty	= mvebu_uart_tx_empty,
+	.set_mctrl	= mvebu_uart_set_mctrl,
+	.get_mctrl	= mvebu_uart_get_mctrl,
+	.stop_tx	= mvebu_uart_stop_tx,
+	.start_tx	= mvebu_uart_start_tx,
+	.stop_rx	= mvebu_uart_stop_rx,
+	.break_ctl	= mvebu_uart_break_ctl,
+	.startup	= mvebu_uart_startup,
+	.shutdown	= mvebu_uart_shutdown,
+	.set_termios	= mvebu_uart_set_termios,
+	.type		= mvebu_uart_type,
+	.release_port	= mvebu_uart_release_port,
+	.request_port	= mvebu_uart_request_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= mvebu_uart_get_poll_char,
+	.poll_put_char	= mvebu_uart_put_poll_char,
+#endif
+};
+
+/* Console Driver Operations  */
+
+#ifdef CONFIG_SERIAL_MVEBU_CONSOLE
+/* Early Console */
+static void mvebu_uart_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned int st;
+
+	for (;;) {
+		st = readl(port->membase + UART_STAT);
+		if (!(st & STAT_TX_FIFO_FUL))
+			break;
+	}
+
+	/* At early stage, DT is not parsed yet, only use UART0 */
+	writel(c, port->membase + UART_STD_TSH);
+
+	for (;;) {
+		st = readl(port->membase + UART_STAT);
+		if (st & STAT_TX_FIFO_EMP)
+			break;
+	}
+}
+
+static void mvebu_uart_putc_early_write(struct console *con,
+					const char *s,
+					unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, mvebu_uart_putc);
+}
+
+static int __init
+mvebu_uart_early_console_setup(struct earlycon_device *device,
+			       const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = mvebu_uart_putc_early_write;
+
+	return 0;
+}
+
+EARLYCON_DECLARE(ar3700_uart, mvebu_uart_early_console_setup);
+OF_EARLYCON_DECLARE(ar3700_uart, "marvell,armada-3700-uart",
+		    mvebu_uart_early_console_setup);
+
+static void wait_for_xmitr(struct uart_port *port)
+{
+	u32 val;
+
+	readl_poll_timeout_atomic(port->membase + UART_STAT, val,
+				  (val & STAT_TX_RDY(port)), 1, 10000);
+}
+
+static void wait_for_xmite(struct uart_port *port)
+{
+	u32 val;
+
+	readl_poll_timeout_atomic(port->membase + UART_STAT, val,
+				  (val & STAT_TX_EMP), 1, 10000);
+}
+
+static void mvebu_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	wait_for_xmitr(port);
+	writel(ch, port->membase + UART_TSH(port));
+}
+
+static void mvebu_uart_console_write(struct console *co, const char *s,
+				     unsigned int count)
+{
+	struct uart_port *port = &mvebu_uart_ports[co->index];
+	unsigned long flags;
+	unsigned int ier, intr, ctl;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
+	intr = readl(port->membase + UART_INTR(port)) &
+		(CTRL_RX_RDY_INT(port) | CTRL_TX_RDY_INT(port));
+	writel(0, port->membase + UART_CTRL(port));
+	writel(0, port->membase + UART_INTR(port));
+
+	uart_console_write(port, s, count, mvebu_uart_console_putchar);
+
+	wait_for_xmite(port);
+
+	if (ier)
+		writel(ier, port->membase + UART_CTRL(port));
+
+	if (intr) {
+		ctl = intr | readl(port->membase + UART_INTR(port));
+		writel(ctl, port->membase + UART_INTR(port));
+	}
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int mvebu_uart_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= MVEBU_NR_UARTS)
+		return -EINVAL;
+
+	port = &mvebu_uart_ports[co->index];
+
+	if (!port->mapbase || !port->membase) {
+		pr_debug("console on ttyMV%i not present\n", co->index);
+		return -ENODEV;
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver mvebu_uart_driver;
+
+static struct console mvebu_uart_console = {
+	.name	= "ttyMV",
+	.write	= mvebu_uart_console_write,
+	.device	= uart_console_device,
+	.setup	= mvebu_uart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &mvebu_uart_driver,
+};
+
+static int __init mvebu_uart_console_init(void)
+{
+	register_console(&mvebu_uart_console);
+	return 0;
+}
+
+console_initcall(mvebu_uart_console_init);
+
+
+#endif /* CONFIG_SERIAL_MVEBU_CONSOLE */
+
+static struct uart_driver mvebu_uart_driver = {
+	.owner			= THIS_MODULE,
+	.driver_name		= DRIVER_NAME,
+	.dev_name		= "ttyMV",
+	.nr			= MVEBU_NR_UARTS,
+#ifdef CONFIG_SERIAL_MVEBU_CONSOLE
+	.cons			= &mvebu_uart_console,
+#endif
+};
+
+#if defined(CONFIG_PM)
+static int mvebu_uart_suspend(struct device *dev)
+{
+	struct mvebu_uart *mvuart = dev_get_drvdata(dev);
+	struct uart_port *port = mvuart->port;
+	unsigned long flags;
+
+	uart_suspend_port(&mvebu_uart_driver, port);
+
+	mvuart->pm_regs.rbr = readl(port->membase + UART_RBR(port));
+	mvuart->pm_regs.tsh = readl(port->membase + UART_TSH(port));
+	mvuart->pm_regs.ctrl = readl(port->membase + UART_CTRL(port));
+	mvuart->pm_regs.intr = readl(port->membase + UART_INTR(port));
+	mvuart->pm_regs.stat = readl(port->membase + UART_STAT);
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+	mvuart->pm_regs.brdv = readl(port->membase + UART_BRDV);
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+	mvuart->pm_regs.osamp = readl(port->membase + UART_OSAMP);
+
+	device_set_wakeup_enable(dev, true);
+
+	return 0;
+}
+
+static int mvebu_uart_resume(struct device *dev)
+{
+	struct mvebu_uart *mvuart = dev_get_drvdata(dev);
+	struct uart_port *port = mvuart->port;
+	unsigned long flags;
+
+	writel(mvuart->pm_regs.rbr, port->membase + UART_RBR(port));
+	writel(mvuart->pm_regs.tsh, port->membase + UART_TSH(port));
+	writel(mvuart->pm_regs.ctrl, port->membase + UART_CTRL(port));
+	writel(mvuart->pm_regs.intr, port->membase + UART_INTR(port));
+	writel(mvuart->pm_regs.stat, port->membase + UART_STAT);
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+	writel(mvuart->pm_regs.brdv, port->membase + UART_BRDV);
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+	writel(mvuart->pm_regs.osamp, port->membase + UART_OSAMP);
+
+	uart_resume_port(&mvebu_uart_driver, port);
+
+	return 0;
+}
+
+static const struct dev_pm_ops mvebu_uart_pm_ops = {
+	.suspend        = mvebu_uart_suspend,
+	.resume         = mvebu_uart_resume,
+};
+#endif /* CONFIG_PM */
+
+static const struct of_device_id mvebu_uart_of_match[];
+
+/* Counter to keep track of each UART port id when not using CONFIG_OF */
+static int uart_num_counter;
+
+static int mvebu_uart_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match = of_match_device(mvebu_uart_of_match,
+							   &pdev->dev);
+	struct uart_port *port;
+	struct mvebu_uart *mvuart;
+	struct resource *reg;
+	int id, irq;
+
+	/* Assume that all UART ports have a DT alias or none has */
+	id = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (!pdev->dev.of_node || id < 0)
+		pdev->id = uart_num_counter++;
+	else
+		pdev->id = id;
+
+	if (pdev->id >= MVEBU_NR_UARTS) {
+		dev_err(&pdev->dev, "cannot have more than %d UART ports\n",
+			MVEBU_NR_UARTS);
+		return -EINVAL;
+	}
+
+	port = &mvebu_uart_ports[pdev->id];
+
+	spin_lock_init(&port->lock);
+
+	port->dev        = &pdev->dev;
+	port->type       = PORT_MVEBU;
+	port->ops        = &mvebu_uart_ops;
+	port->regshift   = 0;
+
+	port->fifosize   = 32;
+	port->iotype     = UPIO_MEM32;
+	port->flags      = UPF_FIXED_PORT;
+	port->line       = pdev->id;
+
+	/*
+	 * IRQ number is not stored in this structure because we may have two of
+	 * them per port (RX and TX). Instead, use the driver UART structure
+	 * array so called ->irq[].
+	 */
+	port->irq        = 0;
+	port->irqflags   = 0;
+
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &reg);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+	port->mapbase    = reg->start;
+
+	mvuart = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_uart),
+			      GFP_KERNEL);
+	if (!mvuart)
+		return -ENOMEM;
+
+	/* Get controller data depending on the compatible string */
+	mvuart->data = (struct mvebu_uart_driver_data *)match->data;
+	mvuart->port = port;
+
+	port->private_data = mvuart;
+	platform_set_drvdata(pdev, mvuart);
+
+	/* Get fixed clock frequency */
+	mvuart->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(mvuart->clk)) {
+		if (PTR_ERR(mvuart->clk) == -EPROBE_DEFER)
+			return PTR_ERR(mvuart->clk);
+
+		if (IS_EXTENDED(port)) {
+			dev_err(&pdev->dev, "unable to get UART clock\n");
+			return PTR_ERR(mvuart->clk);
+		}
+	} else {
+		if (!clk_prepare_enable(mvuart->clk))
+			port->uartclk = clk_get_rate(mvuart->clk);
+	}
+
+	/* Manage interrupts */
+	if (platform_irq_count(pdev) == 1) {
+		/* Old bindings: no name on the single unamed UART0 IRQ */
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0)
+			return irq;
+
+		mvuart->irq[UART_IRQ_SUM] = irq;
+	} else {
+		/*
+		 * New bindings: named interrupts (RX, TX) for both UARTS,
+		 * only make use of uart-rx and uart-tx interrupts, do not use
+		 * uart-sum of UART0 port.
+		 */
+		irq = platform_get_irq_byname(pdev, "uart-rx");
+		if (irq < 0)
+			return irq;
+
+		mvuart->irq[UART_RX_IRQ] = irq;
+
+		irq = platform_get_irq_byname(pdev, "uart-tx");
+		if (irq < 0)
+			return irq;
+
+		mvuart->irq[UART_TX_IRQ] = irq;
+	}
+
+	/* UART Soft Reset*/
+	writel(CTRL_SOFT_RST, port->membase + UART_CTRL(port));
+	udelay(1);
+	writel(0, port->membase + UART_CTRL(port));
+
+	return uart_add_one_port(&mvebu_uart_driver, port);
+}
+
+static struct mvebu_uart_driver_data uart_std_driver_data = {
+	.is_ext = false,
+	.regs.rbr = UART_STD_RBR,
+	.regs.tsh = UART_STD_TSH,
+	.regs.ctrl = UART_STD_CTRL1,
+	.regs.intr = UART_STD_CTRL2,
+	.flags.ctrl_tx_rdy_int = CTRL_STD_TX_RDY_INT,
+	.flags.ctrl_rx_rdy_int = CTRL_STD_RX_RDY_INT,
+	.flags.stat_tx_rdy = STAT_STD_TX_RDY,
+	.flags.stat_rx_rdy = STAT_STD_RX_RDY,
+};
+
+static struct mvebu_uart_driver_data uart_ext_driver_data = {
+	.is_ext = true,
+	.regs.rbr = UART_EXT_RBR,
+	.regs.tsh = UART_EXT_TSH,
+	.regs.ctrl = UART_EXT_CTRL1,
+	.regs.intr = UART_EXT_CTRL2,
+	.flags.ctrl_tx_rdy_int = CTRL_EXT_TX_RDY_INT,
+	.flags.ctrl_rx_rdy_int = CTRL_EXT_RX_RDY_INT,
+	.flags.stat_tx_rdy = STAT_EXT_TX_RDY,
+	.flags.stat_rx_rdy = STAT_EXT_RX_RDY,
+};
+
+/* Match table for of_platform binding */
+static const struct of_device_id mvebu_uart_of_match[] = {
+	{
+		.compatible = "marvell,armada-3700-uart",
+		.data = (void *)&uart_std_driver_data,
+	},
+	{
+		.compatible = "marvell,armada-3700-uart-ext",
+		.data = (void *)&uart_ext_driver_data,
+	},
+	{}
+};
+
+static struct platform_driver mvebu_uart_platform_driver = {
+	.probe	= mvebu_uart_probe,
+	.driver	= {
+		.name  = "mvebu-uart",
+		.of_match_table = of_match_ptr(mvebu_uart_of_match),
+		.suppress_bind_attrs = true,
+#if defined(CONFIG_PM)
+		.pm	= &mvebu_uart_pm_ops,
+#endif /* CONFIG_PM */
+	},
+};
+
+/* This code is based on clk-fixed-factor.c driver and modified. */
+
+struct mvebu_uart_clock {
+	struct clk_hw clk_hw;
+	int clock_idx;
+	u32 pm_context_reg1;
+	u32 pm_context_reg2;
+};
+
+struct mvebu_uart_clock_base {
+	struct mvebu_uart_clock clocks[2];
+	unsigned int parent_rates[5];
+	int parent_idx;
+	unsigned int div;
+	void __iomem *reg1;
+	void __iomem *reg2;
+	bool configured;
+};
+
+#define PARENT_CLOCK_XTAL 4
+
+#define to_uart_clock(hw) container_of(hw, struct mvebu_uart_clock, clk_hw)
+#define to_uart_clock_base(uart_clock) container_of(uart_clock, \
+	struct mvebu_uart_clock_base, clocks[uart_clock->clock_idx])
+
+static int mvebu_uart_clock_prepare(struct clk_hw *hw)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+	unsigned int prev_clock_idx, prev_clock_rate, prev_d1d2;
+	unsigned int parent_clock_idx, parent_clock_rate;
+	unsigned long flags;
+	unsigned int d1, d2;
+	u64 divisor;
+	u32 val;
+
+	/*
+	 * This function just reconfigures UART Clock Control register (located
+	 * in UART1 address space which controls both UART1 and UART2) to
+	 * selected UART base clock and recalculates current UART1/UART2
+	 * divisors in their address spaces, so that final baudrate will not be
+	 * changed by switching UART parent clock. This is required for
+	 * otherwise kernel's boot log stops working - we need to ensure that
+	 * UART baudrate does not change during this setup. It is a one time
+	 * operation, it will execute only once and set `configured` to true,
+	 * and be skipped on subsequent calls. Because this UART Clock Control
+	 * register (UART_BRDV) is shared between UART1 baudrate function,
+	 * UART1 clock selector and UART2 clock selector, every access to
+	 * UART_BRDV (reg1) needs to be protected by a lock.
+	 */
+
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+
+	if (uart_clock_base->configured) {
+		spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+		return 0;
+	}
+
+	parent_clock_idx = uart_clock_base->parent_idx;
+	parent_clock_rate = uart_clock_base->parent_rates[parent_clock_idx];
+
+	val = readl(uart_clock_base->reg1);
+
+	if (uart_clock_base->div > CLK_TBG_DIV1_MAX) {
+		d1 = CLK_TBG_DIV1_MAX;
+		d2 = uart_clock_base->div / CLK_TBG_DIV1_MAX;
+	} else {
+		d1 = uart_clock_base->div;
+		d2 = 1;
+	}
+
+	if (val & CLK_NO_XTAL) {
+		prev_clock_idx = (val >> CLK_TBG_SEL_SHIFT) & CLK_TBG_SEL_MASK;
+		prev_d1d2 = ((val >> CLK_TBG_DIV1_SHIFT) & CLK_TBG_DIV1_MASK) *
+			    ((val >> CLK_TBG_DIV2_SHIFT) & CLK_TBG_DIV2_MASK);
+	} else {
+		prev_clock_idx = PARENT_CLOCK_XTAL;
+		prev_d1d2 = 1;
+	}
+
+	/* Note that uart_clock_base->parent_rates[i] may not be available */
+	prev_clock_rate = uart_clock_base->parent_rates[prev_clock_idx];
+
+	/* Recalculate UART1 divisor so UART1 baudrate does not change */
+	if (prev_clock_rate) {
+		divisor = DIV_U64_ROUND_CLOSEST((u64)(val & BRDV_BAUD_MASK) *
+						parent_clock_rate * prev_d1d2,
+						prev_clock_rate * d1 * d2);
+		if (divisor < 1)
+			divisor = 1;
+		else if (divisor > BRDV_BAUD_MAX)
+			divisor = BRDV_BAUD_MAX;
+		val = (val & ~BRDV_BAUD_MASK) | divisor;
+	}
+
+	if (parent_clock_idx != PARENT_CLOCK_XTAL) {
+		/* Do not use XTAL, select TBG clock and TBG d1 * d2 divisors */
+		val |= CLK_NO_XTAL;
+		val &= ~(CLK_TBG_DIV1_MASK << CLK_TBG_DIV1_SHIFT);
+		val |= d1 << CLK_TBG_DIV1_SHIFT;
+		val &= ~(CLK_TBG_DIV2_MASK << CLK_TBG_DIV2_SHIFT);
+		val |= d2 << CLK_TBG_DIV2_SHIFT;
+		val &= ~(CLK_TBG_SEL_MASK << CLK_TBG_SEL_SHIFT);
+		val |= parent_clock_idx << CLK_TBG_SEL_SHIFT;
+	} else {
+		/* Use XTAL, TBG bits are then ignored */
+		val &= ~CLK_NO_XTAL;
+	}
+
+	writel(val, uart_clock_base->reg1);
+
+	/* Recalculate UART2 divisor so UART2 baudrate does not change */
+	if (prev_clock_rate) {
+		val = readl(uart_clock_base->reg2);
+		divisor = DIV_U64_ROUND_CLOSEST((u64)(val & BRDV_BAUD_MASK) *
+						parent_clock_rate * prev_d1d2,
+						prev_clock_rate * d1 * d2);
+		if (divisor < 1)
+			divisor = 1;
+		else if (divisor > BRDV_BAUD_MAX)
+			divisor = BRDV_BAUD_MAX;
+		val = (val & ~BRDV_BAUD_MASK) | divisor;
+		writel(val, uart_clock_base->reg2);
+	}
+
+	uart_clock_base->configured = true;
+
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+
+	return 0;
+}
+
+static int mvebu_uart_clock_enable(struct clk_hw *hw)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+
+	val = readl(uart_clock_base->reg1);
+
+	if (uart_clock->clock_idx == 0)
+		val &= ~UART1_CLK_DIS;
+	else
+		val &= ~UART2_CLK_DIS;
+
+	writel(val, uart_clock_base->reg1);
+
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+
+	return 0;
+}
+
+static void mvebu_uart_clock_disable(struct clk_hw *hw)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+
+	val = readl(uart_clock_base->reg1);
+
+	if (uart_clock->clock_idx == 0)
+		val |= UART1_CLK_DIS;
+	else
+		val |= UART2_CLK_DIS;
+
+	writel(val, uart_clock_base->reg1);
+
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+}
+
+static int mvebu_uart_clock_is_enabled(struct clk_hw *hw)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+	u32 val;
+
+	val = readl(uart_clock_base->reg1);
+
+	if (uart_clock->clock_idx == 0)
+		return !(val & UART1_CLK_DIS);
+	else
+		return !(val & UART2_CLK_DIS);
+}
+
+static int mvebu_uart_clock_save_context(struct clk_hw *hw)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+	uart_clock->pm_context_reg1 = readl(uart_clock_base->reg1);
+	uart_clock->pm_context_reg2 = readl(uart_clock_base->reg2);
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+
+	return 0;
+}
+
+static void mvebu_uart_clock_restore_context(struct clk_hw *hw)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&mvebu_uart_lock, flags);
+	writel(uart_clock->pm_context_reg1, uart_clock_base->reg1);
+	writel(uart_clock->pm_context_reg2, uart_clock_base->reg2);
+	spin_unlock_irqrestore(&mvebu_uart_lock, flags);
+}
+
+static unsigned long mvebu_uart_clock_recalc_rate(struct clk_hw *hw,
+						  unsigned long parent_rate)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+
+	return parent_rate / uart_clock_base->div;
+}
+
+static long mvebu_uart_clock_round_rate(struct clk_hw *hw, unsigned long rate,
+					unsigned long *parent_rate)
+{
+	struct mvebu_uart_clock *uart_clock = to_uart_clock(hw);
+	struct mvebu_uart_clock_base *uart_clock_base =
+						to_uart_clock_base(uart_clock);
+
+	return *parent_rate / uart_clock_base->div;
+}
+
+static int mvebu_uart_clock_set_rate(struct clk_hw *hw, unsigned long rate,
+				     unsigned long parent_rate)
+{
+	/*
+	 * We must report success but we can do so unconditionally because
+	 * mvebu_uart_clock_round_rate returns values that ensure this call is a
+	 * nop.
+	 */
+
+	return 0;
+}
+
+static const struct clk_ops mvebu_uart_clock_ops = {
+	.prepare = mvebu_uart_clock_prepare,
+	.enable = mvebu_uart_clock_enable,
+	.disable = mvebu_uart_clock_disable,
+	.is_enabled = mvebu_uart_clock_is_enabled,
+	.save_context = mvebu_uart_clock_save_context,
+	.restore_context = mvebu_uart_clock_restore_context,
+	.round_rate = mvebu_uart_clock_round_rate,
+	.set_rate = mvebu_uart_clock_set_rate,
+	.recalc_rate = mvebu_uart_clock_recalc_rate,
+};
+
+static int mvebu_uart_clock_register(struct device *dev,
+				     struct mvebu_uart_clock *uart_clock,
+				     const char *name,
+				     const char *parent_name)
+{
+	struct clk_init_data init = { };
+
+	uart_clock->clk_hw.init = &init;
+
+	init.name = name;
+	init.ops = &mvebu_uart_clock_ops;
+	init.flags = 0;
+	init.num_parents = 1;
+	init.parent_names = &parent_name;
+
+	return devm_clk_hw_register(dev, &uart_clock->clk_hw);
+}
+
+static int mvebu_uart_clock_probe(struct platform_device *pdev)
+{
+	static const char *const uart_clk_names[] = { "uart_1", "uart_2" };
+	static const char *const parent_clk_names[] = { "TBG-A-P", "TBG-B-P",
+							"TBG-A-S", "TBG-B-S",
+							"xtal" };
+	struct clk *parent_clks[ARRAY_SIZE(parent_clk_names)];
+	struct mvebu_uart_clock_base *uart_clock_base;
+	struct clk_hw_onecell_data *hw_clk_data;
+	struct device *dev = &pdev->dev;
+	int i, parent_clk_idx, ret;
+	unsigned long div, rate;
+	struct resource *res;
+	unsigned int d1, d2;
+
+	BUILD_BUG_ON(ARRAY_SIZE(uart_clk_names) !=
+		     ARRAY_SIZE(uart_clock_base->clocks));
+	BUILD_BUG_ON(ARRAY_SIZE(parent_clk_names) !=
+		     ARRAY_SIZE(uart_clock_base->parent_rates));
+
+	uart_clock_base = devm_kzalloc(dev,
+				       sizeof(*uart_clock_base),
+				       GFP_KERNEL);
+	if (!uart_clock_base)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Couldn't get first register\n");
+		return -ENOENT;
+	}
+
+	/*
+	 * UART Clock Control register (reg1 / UART_BRDV) is in the address
+	 * space of UART1 (standard UART variant), controls parent clock and
+	 * dividers for both UART1 and UART2 and is supplied via DT as the first
+	 * resource. Therefore use ioremap() rather than ioremap_resource() to
+	 * avoid conflicts with UART1 driver. Access to UART_BRDV is protected
+	 * by a lock shared between clock and UART driver.
+	 */
+	uart_clock_base->reg1 = devm_ioremap(dev, res->start,
+					     resource_size(res));
+	if (!uart_clock_base->reg1)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(dev, "Couldn't get second register\n");
+		return -ENOENT;
+	}
+
+	/*
+	 * UART 2 Baud Rate Divisor register (reg2 / UART_BRDV) is in address
+	 * space of UART2 (extended UART variant), controls only one UART2
+	 * specific divider and is supplied via DT as second resource.
+	 * Therefore use ioremap() rather than ioremap_resource() to avoid
+	 * conflicts with UART2 driver. Access to UART_BRDV is protected by a
+	 * by lock shared between clock and UART driver.
+	 */
+	uart_clock_base->reg2 = devm_ioremap(dev, res->start,
+					     resource_size(res));
+	if (!uart_clock_base->reg2)
+		return -ENOMEM;
+
+	hw_clk_data = devm_kzalloc(dev,
+				   struct_size(hw_clk_data, hws,
+					       ARRAY_SIZE(uart_clk_names)),
+				   GFP_KERNEL);
+	if (!hw_clk_data)
+		return -ENOMEM;
+
+	hw_clk_data->num = ARRAY_SIZE(uart_clk_names);
+	for (i = 0; i < ARRAY_SIZE(uart_clk_names); i++) {
+		hw_clk_data->hws[i] = &uart_clock_base->clocks[i].clk_hw;
+		uart_clock_base->clocks[i].clock_idx = i;
+	}
+
+	parent_clk_idx = -1;
+
+	for (i = 0; i < ARRAY_SIZE(parent_clk_names); i++) {
+		parent_clks[i] = devm_clk_get(dev, parent_clk_names[i]);
+		if (IS_ERR(parent_clks[i])) {
+			if (PTR_ERR(parent_clks[i]) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+			dev_warn(dev, "Couldn't get the parent clock %s: %ld\n",
+				 parent_clk_names[i], PTR_ERR(parent_clks[i]));
+			continue;
+		}
+
+		ret = clk_prepare_enable(parent_clks[i]);
+		if (ret) {
+			dev_warn(dev, "Couldn't enable parent clock %s: %d\n",
+				 parent_clk_names[i], ret);
+			continue;
+		}
+		rate = clk_get_rate(parent_clks[i]);
+		uart_clock_base->parent_rates[i] = rate;
+
+		if (i != PARENT_CLOCK_XTAL) {
+			/*
+			 * Calculate the smallest TBG d1 and d2 divisors that
+			 * still can provide 9600 baudrate.
+			 */
+			d1 = DIV_ROUND_UP(rate, 9600 * OSAMP_MAX_DIVISOR *
+					  BRDV_BAUD_MAX);
+			if (d1 < 1)
+				d1 = 1;
+			else if (d1 > CLK_TBG_DIV1_MAX)
+				d1 = CLK_TBG_DIV1_MAX;
+
+			d2 = DIV_ROUND_UP(rate, 9600 * OSAMP_MAX_DIVISOR *
+					  BRDV_BAUD_MAX * d1);
+			if (d2 < 1)
+				d2 = 1;
+			else if (d2 > CLK_TBG_DIV2_MAX)
+				d2 = CLK_TBG_DIV2_MAX;
+		} else {
+			/*
+			 * When UART clock uses XTAL clock as a source then it
+			 * is not possible to use d1 and d2 divisors.
+			 */
+			d1 = d2 = 1;
+		}
+
+		/* Skip clock source which cannot provide 9600 baudrate */
+		if (rate > 9600 * OSAMP_MAX_DIVISOR * BRDV_BAUD_MAX * d1 * d2)
+			continue;
+
+		/*
+		 * Choose TBG clock source with the smallest divisors. Use XTAL
+		 * clock source only in case TBG is not available as XTAL cannot
+		 * be used for baudrates higher than 230400.
+		 */
+		if (parent_clk_idx == -1 ||
+		    (i != PARENT_CLOCK_XTAL && div > d1 * d2)) {
+			parent_clk_idx = i;
+			div = d1 * d2;
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(parent_clk_names); i++) {
+		if (i == parent_clk_idx || IS_ERR(parent_clks[i]))
+			continue;
+		clk_disable_unprepare(parent_clks[i]);
+		devm_clk_put(dev, parent_clks[i]);
+	}
+
+	if (parent_clk_idx == -1) {
+		dev_err(dev, "No usable parent clock\n");
+		return -ENOENT;
+	}
+
+	uart_clock_base->parent_idx = parent_clk_idx;
+	uart_clock_base->div = div;
+
+	dev_notice(dev, "Using parent clock %s as base UART clock\n",
+		   __clk_get_name(parent_clks[parent_clk_idx]));
+
+	for (i = 0; i < ARRAY_SIZE(uart_clk_names); i++) {
+		ret = mvebu_uart_clock_register(dev,
+				&uart_clock_base->clocks[i],
+				uart_clk_names[i],
+				__clk_get_name(parent_clks[parent_clk_idx]));
+		if (ret) {
+			dev_err(dev, "Can't register UART clock %d: %d\n",
+				i, ret);
+			return ret;
+		}
+	}
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					   hw_clk_data);
+}
+
+static const struct of_device_id mvebu_uart_clock_of_match[] = {
+	{ .compatible = "marvell,armada-3700-uart-clock", },
+	{ }
+};
+
+static struct platform_driver mvebu_uart_clock_platform_driver = {
+	.probe = mvebu_uart_clock_probe,
+	.driver		= {
+		.name	= "mvebu-uart-clock",
+		.of_match_table = mvebu_uart_clock_of_match,
+	},
+};
+
+static int __init mvebu_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&mvebu_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&mvebu_uart_clock_platform_driver);
+	if (ret) {
+		uart_unregister_driver(&mvebu_uart_driver);
+		return ret;
+	}
+
+	ret = platform_driver_register(&mvebu_uart_platform_driver);
+	if (ret) {
+		platform_driver_unregister(&mvebu_uart_clock_platform_driver);
+		uart_unregister_driver(&mvebu_uart_driver);
+		return ret;
+	}
+
+	return 0;
+}
+arch_initcall(mvebu_uart_init);
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
new file mode 100644
index 000000000..8eeecf8ad
--- /dev/null
+++ b/drivers/tty/serial/mxs-auart.c
@@ -0,0 +1,1743 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Application UART driver for:
+ *	Freescale STMP37XX/STMP378X
+ *	Alphascale ASM9260
+ *
+ * Author: dmitry pervushin <dimka@embeddedalley.com>
+ *
+ * Copyright 2014 Oleksij Rempel <linux@rempel-privat.de>
+ *	Provide Alphascale ASM9260 support.
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+
+#include <linux/gpio/consumer.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include "serial_mctrl_gpio.h"
+
+#define MXS_AUART_PORTS 5
+#define MXS_AUART_FIFO_SIZE		16
+
+#define SET_REG				0x4
+#define CLR_REG				0x8
+#define TOG_REG				0xc
+
+#define AUART_CTRL0			0x00000000
+#define AUART_CTRL1			0x00000010
+#define AUART_CTRL2			0x00000020
+#define AUART_LINECTRL			0x00000030
+#define AUART_LINECTRL2			0x00000040
+#define AUART_INTR			0x00000050
+#define AUART_DATA			0x00000060
+#define AUART_STAT			0x00000070
+#define AUART_DEBUG			0x00000080
+#define AUART_VERSION			0x00000090
+#define AUART_AUTOBAUD			0x000000a0
+
+#define AUART_CTRL0_SFTRST			(1 << 31)
+#define AUART_CTRL0_CLKGATE			(1 << 30)
+#define AUART_CTRL0_RXTO_ENABLE			(1 << 27)
+#define AUART_CTRL0_RXTIMEOUT(v)		(((v) & 0x7ff) << 16)
+#define AUART_CTRL0_XFER_COUNT(v)		((v) & 0xffff)
+
+#define AUART_CTRL1_XFER_COUNT(v)		((v) & 0xffff)
+
+#define AUART_CTRL2_DMAONERR			(1 << 26)
+#define AUART_CTRL2_TXDMAE			(1 << 25)
+#define AUART_CTRL2_RXDMAE			(1 << 24)
+
+#define AUART_CTRL2_CTSEN			(1 << 15)
+#define AUART_CTRL2_RTSEN			(1 << 14)
+#define AUART_CTRL2_RTS				(1 << 11)
+#define AUART_CTRL2_RXE				(1 << 9)
+#define AUART_CTRL2_TXE				(1 << 8)
+#define AUART_CTRL2_UARTEN			(1 << 0)
+
+#define AUART_LINECTRL_BAUD_DIV_MAX		0x003fffc0
+#define AUART_LINECTRL_BAUD_DIV_MIN		0x000000ec
+#define AUART_LINECTRL_BAUD_DIVINT_SHIFT	16
+#define AUART_LINECTRL_BAUD_DIVINT_MASK		0xffff0000
+#define AUART_LINECTRL_BAUD_DIVINT(v)		(((v) & 0xffff) << 16)
+#define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT	8
+#define AUART_LINECTRL_BAUD_DIVFRAC_MASK	0x00003f00
+#define AUART_LINECTRL_BAUD_DIVFRAC(v)		(((v) & 0x3f) << 8)
+#define AUART_LINECTRL_SPS			(1 << 7)
+#define AUART_LINECTRL_WLEN_MASK		0x00000060
+#define AUART_LINECTRL_WLEN(v)			((((v) - 5) & 0x3) << 5)
+#define AUART_LINECTRL_FEN			(1 << 4)
+#define AUART_LINECTRL_STP2			(1 << 3)
+#define AUART_LINECTRL_EPS			(1 << 2)
+#define AUART_LINECTRL_PEN			(1 << 1)
+#define AUART_LINECTRL_BRK			(1 << 0)
+
+#define AUART_INTR_RTIEN			(1 << 22)
+#define AUART_INTR_TXIEN			(1 << 21)
+#define AUART_INTR_RXIEN			(1 << 20)
+#define AUART_INTR_CTSMIEN			(1 << 17)
+#define AUART_INTR_RTIS				(1 << 6)
+#define AUART_INTR_TXIS				(1 << 5)
+#define AUART_INTR_RXIS				(1 << 4)
+#define AUART_INTR_CTSMIS			(1 << 1)
+
+#define AUART_STAT_BUSY				(1 << 29)
+#define AUART_STAT_CTS				(1 << 28)
+#define AUART_STAT_TXFE				(1 << 27)
+#define AUART_STAT_TXFF				(1 << 25)
+#define AUART_STAT_RXFE				(1 << 24)
+#define AUART_STAT_OERR				(1 << 19)
+#define AUART_STAT_BERR				(1 << 18)
+#define AUART_STAT_PERR				(1 << 17)
+#define AUART_STAT_FERR				(1 << 16)
+#define AUART_STAT_RXCOUNT_MASK			0xffff
+
+/*
+ * Start of Alphascale asm9260 defines
+ * This list contains only differences of existing bits
+ * between imx2x and asm9260
+ */
+#define ASM9260_HW_CTRL0			0x0000
+/*
+ * RW. Tell the UART to execute the RX DMA Command. The
+ * UART will clear this bit at the end of receive execution.
+ */
+#define ASM9260_BM_CTRL0_RXDMA_RUN		BIT(28)
+/* RW. 0 use FIFO for status register; 1 use DMA */
+#define ASM9260_BM_CTRL0_RXTO_SOURCE_STATUS	BIT(25)
+/*
+ * RW. RX TIMEOUT Enable. Valid for FIFO and DMA.
+ * Warning: If this bit is set to 0, the RX timeout will not affect receive DMA
+ * operation. If this bit is set to 1, a receive timeout will cause the receive
+ * DMA logic to terminate by filling the remaining DMA bytes with garbage data.
+ */
+#define ASM9260_BM_CTRL0_RXTO_ENABLE		BIT(24)
+/*
+ * RW. Receive Timeout Counter Value: number of 8-bit-time to wait before
+ * asserting timeout on the RX input. If the RXFIFO is not empty and the RX
+ * input is idle, then the watchdog counter will decrement each bit-time. Note
+ * 7-bit-time is added to the programmed value, so a value of zero will set
+ * the counter to 7-bit-time, a value of 0x1 gives 15-bit-time and so on. Also
+ * note that the counter is reloaded at the end of each frame, so if the frame
+ * is 10 bits long and the timeout counter value is zero, then timeout will
+ * occur (when FIFO is not empty) even if the RX input is not idle. The default
+ * value is 0x3 (31 bit-time).
+ */
+#define ASM9260_BM_CTRL0_RXTO_MASK		(0xff << 16)
+/* TIMEOUT = (100*7+1)*(1/BAUD) */
+#define ASM9260_BM_CTRL0_DEFAULT_RXTIMEOUT	(20 << 16)
+
+/* TX ctrl register */
+#define ASM9260_HW_CTRL1			0x0010
+/*
+ * RW. Tell the UART to execute the TX DMA Command. The
+ * UART will clear this bit at the end of transmit execution.
+ */
+#define ASM9260_BM_CTRL1_TXDMA_RUN		BIT(28)
+
+#define ASM9260_HW_CTRL2			0x0020
+/*
+ * RW. Receive Interrupt FIFO Level Select.
+ * The trigger points for the receive interrupt are as follows:
+ * ONE_EIGHTHS = 0x0 Trigger on FIFO full to at least 2 of 16 entries.
+ * ONE_QUARTER = 0x1 Trigger on FIFO full to at least 4 of 16 entries.
+ * ONE_HALF = 0x2 Trigger on FIFO full to at least 8 of 16 entries.
+ * THREE_QUARTERS = 0x3 Trigger on FIFO full to at least 12 of 16 entries.
+ * SEVEN_EIGHTHS = 0x4 Trigger on FIFO full to at least 14 of 16 entries.
+ */
+#define ASM9260_BM_CTRL2_RXIFLSEL		(7 << 20)
+#define ASM9260_BM_CTRL2_DEFAULT_RXIFLSEL	(3 << 20)
+/* RW. Same as RXIFLSEL */
+#define ASM9260_BM_CTRL2_TXIFLSEL		(7 << 16)
+#define ASM9260_BM_CTRL2_DEFAULT_TXIFLSEL	(2 << 16)
+/* RW. Set DTR. When this bit is 1, the output is 0. */
+#define ASM9260_BM_CTRL2_DTR			BIT(10)
+/* RW. Loop Back Enable */
+#define ASM9260_BM_CTRL2_LBE			BIT(7)
+#define ASM9260_BM_CTRL2_PORT_ENABLE		BIT(0)
+
+#define ASM9260_HW_LINECTRL			0x0030
+/*
+ * RW. Stick Parity Select. When bits 1, 2, and 7 of this register are set, the
+ * parity bit is transmitted and checked as a 0. When bits 1 and 7 are set,
+ * and bit 2 is 0, the parity bit is transmitted and checked as a 1. When this
+ * bit is cleared stick parity is disabled.
+ */
+#define ASM9260_BM_LCTRL_SPS			BIT(7)
+/* RW. Word length */
+#define ASM9260_BM_LCTRL_WLEN			(3 << 5)
+#define ASM9260_BM_LCTRL_CHRL_5			(0 << 5)
+#define ASM9260_BM_LCTRL_CHRL_6			(1 << 5)
+#define ASM9260_BM_LCTRL_CHRL_7			(2 << 5)
+#define ASM9260_BM_LCTRL_CHRL_8			(3 << 5)
+
+/*
+ * Interrupt register.
+ * contains the interrupt enables and the interrupt status bits
+ */
+#define ASM9260_HW_INTR				0x0040
+/* Tx FIFO EMPTY Raw Interrupt enable */
+#define ASM9260_BM_INTR_TFEIEN			BIT(27)
+/* Overrun Error Interrupt Enable. */
+#define ASM9260_BM_INTR_OEIEN			BIT(26)
+/* Break Error Interrupt Enable. */
+#define ASM9260_BM_INTR_BEIEN			BIT(25)
+/* Parity Error Interrupt Enable. */
+#define ASM9260_BM_INTR_PEIEN			BIT(24)
+/* Framing Error Interrupt Enable. */
+#define ASM9260_BM_INTR_FEIEN			BIT(23)
+
+/* nUARTDSR Modem Interrupt Enable. */
+#define ASM9260_BM_INTR_DSRMIEN			BIT(19)
+/* nUARTDCD Modem Interrupt Enable. */
+#define ASM9260_BM_INTR_DCDMIEN			BIT(18)
+/* nUARTRI Modem Interrupt Enable. */
+#define ASM9260_BM_INTR_RIMIEN			BIT(16)
+/* Auto-Boud Timeout */
+#define ASM9260_BM_INTR_ABTO			BIT(13)
+#define ASM9260_BM_INTR_ABEO			BIT(12)
+/* Tx FIFO EMPTY Raw Interrupt state */
+#define ASM9260_BM_INTR_TFEIS			BIT(11)
+/* Overrun Error */
+#define ASM9260_BM_INTR_OEIS			BIT(10)
+/* Break Error */
+#define ASM9260_BM_INTR_BEIS			BIT(9)
+/* Parity Error */
+#define ASM9260_BM_INTR_PEIS			BIT(8)
+/* Framing Error */
+#define ASM9260_BM_INTR_FEIS			BIT(7)
+#define ASM9260_BM_INTR_DSRMIS			BIT(3)
+#define ASM9260_BM_INTR_DCDMIS			BIT(2)
+#define ASM9260_BM_INTR_RIMIS			BIT(0)
+
+/*
+ * RW. In DMA mode, up to 4 Received/Transmit characters can be accessed at a
+ * time. In PIO mode, only one character can be accessed at a time. The status
+ * register contains the receive data flags and valid bits.
+ */
+#define ASM9260_HW_DATA				0x0050
+
+#define ASM9260_HW_STAT				0x0060
+/* RO. If 1, UARTAPP is present in this product. */
+#define ASM9260_BM_STAT_PRESENT			BIT(31)
+/* RO. If 1, HISPEED is present in this product. */
+#define ASM9260_BM_STAT_HISPEED			BIT(30)
+/* RO. Receive FIFO Full. */
+#define ASM9260_BM_STAT_RXFULL			BIT(26)
+
+/* RO. The UART Debug Register contains the state of the DMA signals. */
+#define ASM9260_HW_DEBUG			0x0070
+/* DMA Command Run Status */
+#define ASM9260_BM_DEBUG_TXDMARUN		BIT(5)
+#define ASM9260_BM_DEBUG_RXDMARUN		BIT(4)
+/* DMA Command End Status */
+#define ASM9260_BM_DEBUG_TXCMDEND		BIT(3)
+#define ASM9260_BM_DEBUG_RXCMDEND		BIT(2)
+/* DMA Request Status */
+#define ASM9260_BM_DEBUG_TXDMARQ		BIT(1)
+#define ASM9260_BM_DEBUG_RXDMARQ		BIT(0)
+
+#define ASM9260_HW_ILPR				0x0080
+
+#define ASM9260_HW_RS485CTRL			0x0090
+/*
+ * RW. This bit reverses the polarity of the direction control signal on the RTS
+ * (or DTR) pin.
+ * If 0, The direction control pin will be driven to logic ‘0’ when the
+ * transmitter has data to be sent. It will be driven to logic ‘1’ after the
+ * last bit of data has been transmitted.
+ */
+#define ASM9260_BM_RS485CTRL_ONIV		BIT(5)
+/* RW. Enable Auto Direction Control. */
+#define ASM9260_BM_RS485CTRL_DIR_CTRL		BIT(4)
+/*
+ * RW. If 0 and DIR_CTRL = 1, pin RTS is used for direction control.
+ * If 1 and DIR_CTRL = 1, pin DTR is used for direction control.
+ */
+#define ASM9260_BM_RS485CTRL_PINSEL		BIT(3)
+/* RW. Enable Auto Address Detect (AAD). */
+#define ASM9260_BM_RS485CTRL_AADEN		BIT(2)
+/* RW. Disable receiver. */
+#define ASM9260_BM_RS485CTRL_RXDIS		BIT(1)
+/* RW. Enable RS-485/EIA-485 Normal Multidrop Mode (NMM) */
+#define ASM9260_BM_RS485CTRL_RS485EN		BIT(0)
+
+#define ASM9260_HW_RS485ADRMATCH		0x00a0
+/* Contains the address match value. */
+#define ASM9260_BM_RS485ADRMATCH_MASK		(0xff << 0)
+
+#define ASM9260_HW_RS485DLY			0x00b0
+/*
+ * RW. Contains the direction control (RTS or DTR) delay value. This delay time
+ * is in periods of the baud clock.
+ */
+#define ASM9260_BM_RS485DLY_MASK		(0xff << 0)
+
+#define ASM9260_HW_AUTOBAUD			0x00c0
+/* WO. Auto-baud time-out interrupt clear bit. */
+#define ASM9260_BM_AUTOBAUD_TO_INT_CLR		BIT(9)
+/* WO. End of auto-baud interrupt clear bit. */
+#define ASM9260_BM_AUTOBAUD_EO_INT_CLR		BIT(8)
+/* Restart in case of timeout (counter restarts at next UART Rx falling edge) */
+#define ASM9260_BM_AUTOBAUD_AUTORESTART		BIT(2)
+/* Auto-baud mode select bit. 0 - Mode 0, 1 - Mode 1. */
+#define ASM9260_BM_AUTOBAUD_MODE		BIT(1)
+/*
+ * Auto-baud start (auto-baud is running). Auto-baud run bit. This bit is
+ * automatically cleared after auto-baud completion.
+ */
+#define ASM9260_BM_AUTOBAUD_START		BIT(0)
+
+#define ASM9260_HW_CTRL3			0x00d0
+#define ASM9260_BM_CTRL3_OUTCLK_DIV_MASK	(0xffff << 16)
+/*
+ * RW. Provide clk over OUTCLK pin. In case of asm9260 it can be configured on
+ * pins 137 and 144.
+ */
+#define ASM9260_BM_CTRL3_MASTERMODE		BIT(6)
+/* RW. Baud Rate Mode: 1 - Enable sync mode. 0 - async mode. */
+#define ASM9260_BM_CTRL3_SYNCMODE		BIT(4)
+/* RW. 1 - MSB bit send frist; 0 - LSB bit frist. */
+#define ASM9260_BM_CTRL3_MSBF			BIT(2)
+/* RW. 1 - sample rate = 8 x Baudrate; 0 - sample rate = 16 x Baudrate. */
+#define ASM9260_BM_CTRL3_BAUD8			BIT(1)
+/* RW. 1 - Set word length to 9bit. 0 - use ASM9260_BM_LCTRL_WLEN */
+#define ASM9260_BM_CTRL3_9BIT			BIT(0)
+
+#define ASM9260_HW_ISO7816_CTRL			0x00e0
+/* RW. Enable High Speed mode. */
+#define ASM9260_BM_ISO7816CTRL_HS		BIT(12)
+/* Disable Successive Receive NACK */
+#define ASM9260_BM_ISO7816CTRL_DS_NACK		BIT(8)
+#define ASM9260_BM_ISO7816CTRL_MAX_ITER_MASK	(0xff << 4)
+/* Receive NACK Inhibit */
+#define ASM9260_BM_ISO7816CTRL_INACK		BIT(3)
+#define ASM9260_BM_ISO7816CTRL_NEG_DATA		BIT(2)
+/* RW. 1 - ISO7816 mode; 0 - USART mode */
+#define ASM9260_BM_ISO7816CTRL_ENABLE		BIT(0)
+
+#define ASM9260_HW_ISO7816_ERRCNT		0x00f0
+/* Parity error counter. Will be cleared after reading */
+#define ASM9260_BM_ISO7816_NB_ERRORS_MASK	(0xff << 0)
+
+#define ASM9260_HW_ISO7816_STATUS		0x0100
+/* Max number of Repetitions Reached */
+#define ASM9260_BM_ISO7816_STAT_ITERATION	BIT(0)
+
+/* End of Alphascale asm9260 defines */
+
+static struct uart_driver auart_driver;
+
+enum mxs_auart_type {
+	IMX23_AUART,
+	IMX28_AUART,
+	ASM9260_AUART,
+};
+
+struct vendor_data {
+	const u16	*reg_offset;
+};
+
+enum {
+	REG_CTRL0,
+	REG_CTRL1,
+	REG_CTRL2,
+	REG_LINECTRL,
+	REG_LINECTRL2,
+	REG_INTR,
+	REG_DATA,
+	REG_STAT,
+	REG_DEBUG,
+	REG_VERSION,
+	REG_AUTOBAUD,
+
+	/* The size of the array - must be last */
+	REG_ARRAY_SIZE,
+};
+
+static const u16 mxs_asm9260_offsets[REG_ARRAY_SIZE] = {
+	[REG_CTRL0] = ASM9260_HW_CTRL0,
+	[REG_CTRL1] = ASM9260_HW_CTRL1,
+	[REG_CTRL2] = ASM9260_HW_CTRL2,
+	[REG_LINECTRL] = ASM9260_HW_LINECTRL,
+	[REG_INTR] = ASM9260_HW_INTR,
+	[REG_DATA] = ASM9260_HW_DATA,
+	[REG_STAT] = ASM9260_HW_STAT,
+	[REG_DEBUG] = ASM9260_HW_DEBUG,
+	[REG_AUTOBAUD] = ASM9260_HW_AUTOBAUD,
+};
+
+static const u16 mxs_stmp37xx_offsets[REG_ARRAY_SIZE] = {
+	[REG_CTRL0] = AUART_CTRL0,
+	[REG_CTRL1] = AUART_CTRL1,
+	[REG_CTRL2] = AUART_CTRL2,
+	[REG_LINECTRL] = AUART_LINECTRL,
+	[REG_LINECTRL2] = AUART_LINECTRL2,
+	[REG_INTR] = AUART_INTR,
+	[REG_DATA] = AUART_DATA,
+	[REG_STAT] = AUART_STAT,
+	[REG_DEBUG] = AUART_DEBUG,
+	[REG_VERSION] = AUART_VERSION,
+	[REG_AUTOBAUD] = AUART_AUTOBAUD,
+};
+
+static const struct vendor_data vendor_alphascale_asm9260 = {
+	.reg_offset = mxs_asm9260_offsets,
+};
+
+static const struct vendor_data vendor_freescale_stmp37xx = {
+	.reg_offset = mxs_stmp37xx_offsets,
+};
+
+struct mxs_auart_port {
+	struct uart_port port;
+
+#define MXS_AUART_DMA_ENABLED	0x2
+#define MXS_AUART_DMA_TX_SYNC	2  /* bit 2 */
+#define MXS_AUART_DMA_RX_READY	3  /* bit 3 */
+#define MXS_AUART_RTSCTS	4  /* bit 4 */
+	unsigned long flags;
+	unsigned int mctrl_prev;
+	enum mxs_auart_type devtype;
+	const struct vendor_data *vendor;
+
+	struct clk *clk;
+	struct clk *clk_ahb;
+	struct device *dev;
+
+	/* for DMA */
+	struct scatterlist tx_sgl;
+	struct dma_chan	*tx_dma_chan;
+	void *tx_dma_buf;
+
+	struct scatterlist rx_sgl;
+	struct dma_chan	*rx_dma_chan;
+	void *rx_dma_buf;
+
+	struct mctrl_gpios	*gpios;
+	int			gpio_irq[UART_GPIO_MAX];
+	bool			ms_irq_enabled;
+};
+
+static const struct of_device_id mxs_auart_dt_ids[] = {
+	{
+		.compatible = "fsl,imx28-auart",
+		.data = (const void *)IMX28_AUART
+	}, {
+		.compatible = "fsl,imx23-auart",
+		.data = (const void *)IMX23_AUART
+	}, {
+		.compatible = "alphascale,asm9260-auart",
+		.data = (const void *)ASM9260_AUART
+	}, { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids);
+
+static inline int is_imx28_auart(struct mxs_auart_port *s)
+{
+	return s->devtype == IMX28_AUART;
+}
+
+static inline int is_asm9260_auart(struct mxs_auart_port *s)
+{
+	return s->devtype == ASM9260_AUART;
+}
+
+static inline bool auart_dma_enabled(struct mxs_auart_port *s)
+{
+	return s->flags & MXS_AUART_DMA_ENABLED;
+}
+
+static unsigned int mxs_reg_to_offset(const struct mxs_auart_port *uap,
+				      unsigned int reg)
+{
+	return uap->vendor->reg_offset[reg];
+}
+
+static unsigned int mxs_read(const struct mxs_auart_port *uap,
+			     unsigned int reg)
+{
+	void __iomem *addr = uap->port.membase + mxs_reg_to_offset(uap, reg);
+
+	return readl_relaxed(addr);
+}
+
+static void mxs_write(unsigned int val, struct mxs_auart_port *uap,
+		      unsigned int reg)
+{
+	void __iomem *addr = uap->port.membase + mxs_reg_to_offset(uap, reg);
+
+	writel_relaxed(val, addr);
+}
+
+static void mxs_set(unsigned int val, struct mxs_auart_port *uap,
+		    unsigned int reg)
+{
+	void __iomem *addr = uap->port.membase + mxs_reg_to_offset(uap, reg);
+
+	writel_relaxed(val, addr + SET_REG);
+}
+
+static void mxs_clr(unsigned int val, struct mxs_auart_port *uap,
+		    unsigned int reg)
+{
+	void __iomem *addr = uap->port.membase + mxs_reg_to_offset(uap, reg);
+
+	writel_relaxed(val, addr + CLR_REG);
+}
+
+static void mxs_auart_stop_tx(struct uart_port *u);
+
+#define to_auart_port(u) container_of(u, struct mxs_auart_port, port)
+
+static void mxs_auart_tx_chars(struct mxs_auart_port *s);
+
+static void dma_tx_callback(void *param)
+{
+	struct mxs_auart_port *s = param;
+	struct circ_buf *xmit = &s->port.state->xmit;
+
+	dma_unmap_sg(s->dev, &s->tx_sgl, 1, DMA_TO_DEVICE);
+
+	/* clear the bit used to serialize the DMA tx. */
+	clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
+	smp_mb__after_atomic();
+
+	/* wake up the possible processes. */
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&s->port);
+
+	mxs_auart_tx_chars(s);
+}
+
+static int mxs_auart_dma_tx(struct mxs_auart_port *s, int size)
+{
+	struct dma_async_tx_descriptor *desc;
+	struct scatterlist *sgl = &s->tx_sgl;
+	struct dma_chan *channel = s->tx_dma_chan;
+	u32 pio;
+
+	/* [1] : send PIO. Note, the first pio word is CTRL1. */
+	pio = AUART_CTRL1_XFER_COUNT(size);
+	desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)&pio,
+					1, DMA_TRANS_NONE, 0);
+	if (!desc) {
+		dev_err(s->dev, "step 1 error\n");
+		return -EINVAL;
+	}
+
+	/* [2] : set DMA buffer. */
+	sg_init_one(sgl, s->tx_dma_buf, size);
+	dma_map_sg(s->dev, sgl, 1, DMA_TO_DEVICE);
+	desc = dmaengine_prep_slave_sg(channel, sgl,
+			1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dev_err(s->dev, "step 2 error\n");
+		return -EINVAL;
+	}
+
+	/* [3] : submit the DMA */
+	desc->callback = dma_tx_callback;
+	desc->callback_param = s;
+	dmaengine_submit(desc);
+	dma_async_issue_pending(channel);
+	return 0;
+}
+
+static void mxs_auart_tx_chars(struct mxs_auart_port *s)
+{
+	struct circ_buf *xmit = &s->port.state->xmit;
+	bool pending;
+	u8 ch;
+
+	if (auart_dma_enabled(s)) {
+		u32 i = 0;
+		int size;
+		void *buffer = s->tx_dma_buf;
+
+		if (test_and_set_bit(MXS_AUART_DMA_TX_SYNC, &s->flags))
+			return;
+
+		while (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
+			size = min_t(u32, UART_XMIT_SIZE - i,
+				     CIRC_CNT_TO_END(xmit->head,
+						     xmit->tail,
+						     UART_XMIT_SIZE));
+			memcpy(buffer + i, xmit->buf + xmit->tail, size);
+			xmit->tail = (xmit->tail + size) & (UART_XMIT_SIZE - 1);
+
+			i += size;
+			if (i >= UART_XMIT_SIZE)
+				break;
+		}
+
+		if (uart_tx_stopped(&s->port))
+			mxs_auart_stop_tx(&s->port);
+
+		if (i) {
+			mxs_auart_dma_tx(s, i);
+		} else {
+			clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
+			smp_mb__after_atomic();
+		}
+		return;
+	}
+
+	pending = uart_port_tx(&s->port, ch,
+		!(mxs_read(s, REG_STAT) & AUART_STAT_TXFF),
+		mxs_write(ch, s, REG_DATA));
+	if (pending)
+		mxs_set(AUART_INTR_TXIEN, s, REG_INTR);
+	else
+		mxs_clr(AUART_INTR_TXIEN, s, REG_INTR);
+}
+
+static void mxs_auart_rx_char(struct mxs_auart_port *s)
+{
+	u32 stat;
+	u8 c, flag;
+
+	c = mxs_read(s, REG_DATA);
+	stat = mxs_read(s, REG_STAT);
+
+	flag = TTY_NORMAL;
+	s->port.icount.rx++;
+
+	if (stat & AUART_STAT_BERR) {
+		s->port.icount.brk++;
+		if (uart_handle_break(&s->port))
+			goto out;
+	} else if (stat & AUART_STAT_PERR) {
+		s->port.icount.parity++;
+	} else if (stat & AUART_STAT_FERR) {
+		s->port.icount.frame++;
+	}
+
+	/*
+	 * Mask off conditions which should be ingored.
+	 */
+	stat &= s->port.read_status_mask;
+
+	if (stat & AUART_STAT_BERR) {
+		flag = TTY_BREAK;
+	} else if (stat & AUART_STAT_PERR)
+		flag = TTY_PARITY;
+	else if (stat & AUART_STAT_FERR)
+		flag = TTY_FRAME;
+
+	if (stat & AUART_STAT_OERR)
+		s->port.icount.overrun++;
+
+	if (uart_handle_sysrq_char(&s->port, c))
+		goto out;
+
+	uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag);
+out:
+	mxs_write(stat, s, REG_STAT);
+}
+
+static void mxs_auart_rx_chars(struct mxs_auart_port *s)
+{
+	u32 stat = 0;
+
+	for (;;) {
+		stat = mxs_read(s, REG_STAT);
+		if (stat & AUART_STAT_RXFE)
+			break;
+		mxs_auart_rx_char(s);
+	}
+
+	mxs_write(stat, s, REG_STAT);
+	tty_flip_buffer_push(&s->port.state->port);
+}
+
+static int mxs_auart_request_port(struct uart_port *u)
+{
+	return 0;
+}
+
+static int mxs_auart_verify_port(struct uart_port *u,
+				    struct serial_struct *ser)
+{
+	if (u->type != PORT_UNKNOWN && u->type != PORT_IMX)
+		return -EINVAL;
+	return 0;
+}
+
+static void mxs_auart_config_port(struct uart_port *u, int flags)
+{
+}
+
+static const char *mxs_auart_type(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	return dev_name(s->dev);
+}
+
+static void mxs_auart_release_port(struct uart_port *u)
+{
+}
+
+static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	u32 ctrl = mxs_read(s, REG_CTRL2);
+
+	ctrl &= ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS);
+	if (mctrl & TIOCM_RTS) {
+		if (uart_cts_enabled(u))
+			ctrl |= AUART_CTRL2_RTSEN;
+		else
+			ctrl |= AUART_CTRL2_RTS;
+	}
+
+	mxs_write(ctrl, s, REG_CTRL2);
+
+	mctrl_gpio_set(s->gpios, mctrl);
+}
+
+#define MCTRL_ANY_DELTA        (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
+static u32 mxs_auart_modem_status(struct mxs_auart_port *s, u32 mctrl)
+{
+	u32 mctrl_diff;
+
+	mctrl_diff = mctrl ^ s->mctrl_prev;
+	s->mctrl_prev = mctrl;
+	if (mctrl_diff & MCTRL_ANY_DELTA && s->ms_irq_enabled &&
+						s->port.state != NULL) {
+		if (mctrl_diff & TIOCM_RI)
+			s->port.icount.rng++;
+		if (mctrl_diff & TIOCM_DSR)
+			s->port.icount.dsr++;
+		if (mctrl_diff & TIOCM_CD)
+			uart_handle_dcd_change(&s->port, mctrl & TIOCM_CD);
+		if (mctrl_diff & TIOCM_CTS)
+			uart_handle_cts_change(&s->port, mctrl & TIOCM_CTS);
+
+		wake_up_interruptible(&s->port.state->port.delta_msr_wait);
+	}
+	return mctrl;
+}
+
+static u32 mxs_auart_get_mctrl(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+	u32 stat = mxs_read(s, REG_STAT);
+	u32 mctrl = 0;
+
+	if (stat & AUART_STAT_CTS)
+		mctrl |= TIOCM_CTS;
+
+	return mctrl_gpio_get(s->gpios, &mctrl);
+}
+
+/*
+ * Enable modem status interrupts
+ */
+static void mxs_auart_enable_ms(struct uart_port *port)
+{
+	struct mxs_auart_port *s = to_auart_port(port);
+
+	/*
+	 * Interrupt should not be enabled twice
+	 */
+	if (s->ms_irq_enabled)
+		return;
+
+	s->ms_irq_enabled = true;
+
+	if (s->gpio_irq[UART_GPIO_CTS] >= 0)
+		enable_irq(s->gpio_irq[UART_GPIO_CTS]);
+	/* TODO: enable AUART_INTR_CTSMIEN otherwise */
+
+	if (s->gpio_irq[UART_GPIO_DSR] >= 0)
+		enable_irq(s->gpio_irq[UART_GPIO_DSR]);
+
+	if (s->gpio_irq[UART_GPIO_RI] >= 0)
+		enable_irq(s->gpio_irq[UART_GPIO_RI]);
+
+	if (s->gpio_irq[UART_GPIO_DCD] >= 0)
+		enable_irq(s->gpio_irq[UART_GPIO_DCD]);
+}
+
+/*
+ * Disable modem status interrupts
+ */
+static void mxs_auart_disable_ms(struct uart_port *port)
+{
+	struct mxs_auart_port *s = to_auart_port(port);
+
+	/*
+	 * Interrupt should not be disabled twice
+	 */
+	if (!s->ms_irq_enabled)
+		return;
+
+	s->ms_irq_enabled = false;
+
+	if (s->gpio_irq[UART_GPIO_CTS] >= 0)
+		disable_irq(s->gpio_irq[UART_GPIO_CTS]);
+	/* TODO: disable AUART_INTR_CTSMIEN otherwise */
+
+	if (s->gpio_irq[UART_GPIO_DSR] >= 0)
+		disable_irq(s->gpio_irq[UART_GPIO_DSR]);
+
+	if (s->gpio_irq[UART_GPIO_RI] >= 0)
+		disable_irq(s->gpio_irq[UART_GPIO_RI]);
+
+	if (s->gpio_irq[UART_GPIO_DCD] >= 0)
+		disable_irq(s->gpio_irq[UART_GPIO_DCD]);
+}
+
+static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);
+static void dma_rx_callback(void *arg)
+{
+	struct mxs_auart_port *s = (struct mxs_auart_port *) arg;
+	struct tty_port *port = &s->port.state->port;
+	int count;
+	u32 stat;
+
+	dma_unmap_sg(s->dev, &s->rx_sgl, 1, DMA_FROM_DEVICE);
+
+	stat = mxs_read(s, REG_STAT);
+	stat &= ~(AUART_STAT_OERR | AUART_STAT_BERR |
+			AUART_STAT_PERR | AUART_STAT_FERR);
+
+	count = stat & AUART_STAT_RXCOUNT_MASK;
+	tty_insert_flip_string(port, s->rx_dma_buf, count);
+
+	mxs_write(stat, s, REG_STAT);
+	tty_flip_buffer_push(port);
+
+	/* start the next DMA for RX. */
+	mxs_auart_dma_prep_rx(s);
+}
+
+static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s)
+{
+	struct dma_async_tx_descriptor *desc;
+	struct scatterlist *sgl = &s->rx_sgl;
+	struct dma_chan *channel = s->rx_dma_chan;
+	u32 pio[1];
+
+	/* [1] : send PIO */
+	pio[0] = AUART_CTRL0_RXTO_ENABLE
+		| AUART_CTRL0_RXTIMEOUT(0x80)
+		| AUART_CTRL0_XFER_COUNT(UART_XMIT_SIZE);
+	desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
+					1, DMA_TRANS_NONE, 0);
+	if (!desc) {
+		dev_err(s->dev, "step 1 error\n");
+		return -EINVAL;
+	}
+
+	/* [2] : send DMA request */
+	sg_init_one(sgl, s->rx_dma_buf, UART_XMIT_SIZE);
+	dma_map_sg(s->dev, sgl, 1, DMA_FROM_DEVICE);
+	desc = dmaengine_prep_slave_sg(channel, sgl, 1, DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dev_err(s->dev, "step 2 error\n");
+		return -1;
+	}
+
+	/* [3] : submit the DMA, but do not issue it. */
+	desc->callback = dma_rx_callback;
+	desc->callback_param = s;
+	dmaengine_submit(desc);
+	dma_async_issue_pending(channel);
+	return 0;
+}
+
+static void mxs_auart_dma_exit_channel(struct mxs_auart_port *s)
+{
+	if (s->tx_dma_chan) {
+		dma_release_channel(s->tx_dma_chan);
+		s->tx_dma_chan = NULL;
+	}
+	if (s->rx_dma_chan) {
+		dma_release_channel(s->rx_dma_chan);
+		s->rx_dma_chan = NULL;
+	}
+
+	kfree(s->tx_dma_buf);
+	kfree(s->rx_dma_buf);
+	s->tx_dma_buf = NULL;
+	s->rx_dma_buf = NULL;
+}
+
+static void mxs_auart_dma_exit(struct mxs_auart_port *s)
+{
+
+	mxs_clr(AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE | AUART_CTRL2_DMAONERR,
+		s, REG_CTRL2);
+
+	mxs_auart_dma_exit_channel(s);
+	s->flags &= ~MXS_AUART_DMA_ENABLED;
+	clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
+	clear_bit(MXS_AUART_DMA_RX_READY, &s->flags);
+}
+
+static int mxs_auart_dma_init(struct mxs_auart_port *s)
+{
+	if (auart_dma_enabled(s))
+		return 0;
+
+	/* init for RX */
+	s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx");
+	if (!s->rx_dma_chan)
+		goto err_out;
+	s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
+	if (!s->rx_dma_buf)
+		goto err_out;
+
+	/* init for TX */
+	s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx");
+	if (!s->tx_dma_chan)
+		goto err_out;
+	s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
+	if (!s->tx_dma_buf)
+		goto err_out;
+
+	/* set the flags */
+	s->flags |= MXS_AUART_DMA_ENABLED;
+	dev_dbg(s->dev, "enabled the DMA support.");
+
+	/* The DMA buffer is now the FIFO the TTY subsystem can use */
+	s->port.fifosize = UART_XMIT_SIZE;
+
+	return 0;
+
+err_out:
+	mxs_auart_dma_exit_channel(s);
+	return -EINVAL;
+
+}
+
+#define RTS_AT_AUART()	!mctrl_gpio_to_gpiod(s->gpios, UART_GPIO_RTS)
+#define CTS_AT_AUART()	!mctrl_gpio_to_gpiod(s->gpios, UART_GPIO_CTS)
+static void mxs_auart_settermios(struct uart_port *u,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+	u32 ctrl, ctrl2, div;
+	unsigned int cflag, baud, baud_min, baud_max;
+
+	cflag = termios->c_cflag;
+
+	ctrl = AUART_LINECTRL_FEN;
+	ctrl2 = mxs_read(s, REG_CTRL2);
+
+	ctrl |= AUART_LINECTRL_WLEN(tty_get_char_size(cflag));
+
+	/* parity */
+	if (cflag & PARENB) {
+		ctrl |= AUART_LINECTRL_PEN;
+		if ((cflag & PARODD) == 0)
+			ctrl |= AUART_LINECTRL_EPS;
+		if (cflag & CMSPAR)
+			ctrl |= AUART_LINECTRL_SPS;
+	}
+
+	u->read_status_mask = AUART_STAT_OERR;
+
+	if (termios->c_iflag & INPCK)
+		u->read_status_mask |= AUART_STAT_PERR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		u->read_status_mask |= AUART_STAT_BERR;
+
+	/*
+	 * Characters to ignore
+	 */
+	u->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		u->ignore_status_mask |= AUART_STAT_PERR;
+	if (termios->c_iflag & IGNBRK) {
+		u->ignore_status_mask |= AUART_STAT_BERR;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			u->ignore_status_mask |= AUART_STAT_OERR;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if (cflag & CREAD)
+		ctrl2 |= AUART_CTRL2_RXE;
+	else
+		ctrl2 &= ~AUART_CTRL2_RXE;
+
+	/* figure out the stop bits requested */
+	if (cflag & CSTOPB)
+		ctrl |= AUART_LINECTRL_STP2;
+
+	/* figure out the hardware flow control settings */
+	ctrl2 &= ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN);
+	if (cflag & CRTSCTS) {
+		/*
+		 * The DMA has a bug(see errata:2836) in mx23.
+		 * So we can not implement the DMA for auart in mx23,
+		 * we can only implement the DMA support for auart
+		 * in mx28.
+		 */
+		if (is_imx28_auart(s)
+				&& test_bit(MXS_AUART_RTSCTS, &s->flags)) {
+			if (!mxs_auart_dma_init(s))
+				/* enable DMA tranfer */
+				ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE
+				       | AUART_CTRL2_DMAONERR;
+		}
+		/* Even if RTS is GPIO line RTSEN can be enabled because
+		 * the pinctrl configuration decides about RTS pin function */
+		ctrl2 |= AUART_CTRL2_RTSEN;
+		if (CTS_AT_AUART())
+			ctrl2 |= AUART_CTRL2_CTSEN;
+	}
+
+	/* set baud rate */
+	if (is_asm9260_auart(s)) {
+		baud = uart_get_baud_rate(u, termios, old,
+					  u->uartclk * 4 / 0x3FFFFF,
+					  u->uartclk / 16);
+		div = u->uartclk * 4 / baud;
+	} else {
+		baud_min = DIV_ROUND_UP(u->uartclk * 32,
+					AUART_LINECTRL_BAUD_DIV_MAX);
+		baud_max = u->uartclk * 32 / AUART_LINECTRL_BAUD_DIV_MIN;
+		baud = uart_get_baud_rate(u, termios, old, baud_min, baud_max);
+		div = DIV_ROUND_CLOSEST(u->uartclk * 32, baud);
+	}
+
+	ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F);
+	ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6);
+	mxs_write(ctrl, s, REG_LINECTRL);
+
+	mxs_write(ctrl2, s, REG_CTRL2);
+
+	uart_update_timeout(u, termios->c_cflag, baud);
+
+	/* prepare for the DMA RX. */
+	if (auart_dma_enabled(s) &&
+		!test_and_set_bit(MXS_AUART_DMA_RX_READY, &s->flags)) {
+		if (!mxs_auart_dma_prep_rx(s)) {
+			/* Disable the normal RX interrupt. */
+			mxs_clr(AUART_INTR_RXIEN | AUART_INTR_RTIEN,
+				s, REG_INTR);
+		} else {
+			mxs_auart_dma_exit(s);
+			dev_err(s->dev, "We can not start up the DMA.\n");
+		}
+	}
+
+	/* CTS flow-control and modem-status interrupts */
+	if (UART_ENABLE_MS(u, termios->c_cflag))
+		mxs_auart_enable_ms(u);
+	else
+		mxs_auart_disable_ms(u);
+}
+
+static void mxs_auart_set_ldisc(struct uart_port *port,
+				struct ktermios *termios)
+{
+	if (termios->c_line == N_PPS) {
+		port->flags |= UPF_HARDPPS_CD;
+		mxs_auart_enable_ms(port);
+	} else {
+		port->flags &= ~UPF_HARDPPS_CD;
+	}
+}
+
+static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
+{
+	u32 istat;
+	struct mxs_auart_port *s = context;
+	u32 mctrl_temp = s->mctrl_prev;
+	u32 stat = mxs_read(s, REG_STAT);
+
+	istat = mxs_read(s, REG_INTR);
+
+	/* ack irq */
+	mxs_clr(istat & (AUART_INTR_RTIS | AUART_INTR_TXIS | AUART_INTR_RXIS
+		| AUART_INTR_CTSMIS), s, REG_INTR);
+
+	/*
+	 * Dealing with GPIO interrupt
+	 */
+	if (irq == s->gpio_irq[UART_GPIO_CTS] ||
+	    irq == s->gpio_irq[UART_GPIO_DCD] ||
+	    irq == s->gpio_irq[UART_GPIO_DSR] ||
+	    irq == s->gpio_irq[UART_GPIO_RI])
+		mxs_auart_modem_status(s,
+				mctrl_gpio_get(s->gpios, &mctrl_temp));
+
+	if (istat & AUART_INTR_CTSMIS) {
+		if (CTS_AT_AUART() && s->ms_irq_enabled)
+			uart_handle_cts_change(&s->port,
+					stat & AUART_STAT_CTS);
+		mxs_clr(AUART_INTR_CTSMIS, s, REG_INTR);
+		istat &= ~AUART_INTR_CTSMIS;
+	}
+
+	if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) {
+		if (!auart_dma_enabled(s))
+			mxs_auart_rx_chars(s);
+		istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS);
+	}
+
+	if (istat & AUART_INTR_TXIS) {
+		mxs_auart_tx_chars(s);
+		istat &= ~AUART_INTR_TXIS;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void mxs_auart_reset_deassert(struct mxs_auart_port *s)
+{
+	int i;
+	unsigned int reg;
+
+	mxs_clr(AUART_CTRL0_SFTRST, s, REG_CTRL0);
+
+	for (i = 0; i < 10000; i++) {
+		reg = mxs_read(s, REG_CTRL0);
+		if (!(reg & AUART_CTRL0_SFTRST))
+			break;
+		udelay(3);
+	}
+	mxs_clr(AUART_CTRL0_CLKGATE, s, REG_CTRL0);
+}
+
+static void mxs_auart_reset_assert(struct mxs_auart_port *s)
+{
+	int i;
+	u32 reg;
+
+	reg = mxs_read(s, REG_CTRL0);
+	/* if already in reset state, keep it untouched */
+	if (reg & AUART_CTRL0_SFTRST)
+		return;
+
+	mxs_clr(AUART_CTRL0_CLKGATE, s, REG_CTRL0);
+	mxs_set(AUART_CTRL0_SFTRST, s, REG_CTRL0);
+
+	for (i = 0; i < 1000; i++) {
+		reg = mxs_read(s, REG_CTRL0);
+		/* reset is finished when the clock is gated */
+		if (reg & AUART_CTRL0_CLKGATE)
+			return;
+		udelay(10);
+	}
+
+	dev_err(s->dev, "Failed to reset the unit.");
+}
+
+static int mxs_auart_startup(struct uart_port *u)
+{
+	int ret;
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	ret = clk_prepare_enable(s->clk);
+	if (ret)
+		return ret;
+
+	if (uart_console(u)) {
+		mxs_clr(AUART_CTRL0_CLKGATE, s, REG_CTRL0);
+	} else {
+		/* reset the unit to a well known state */
+		mxs_auart_reset_assert(s);
+		mxs_auart_reset_deassert(s);
+	}
+
+	mxs_set(AUART_CTRL2_UARTEN, s, REG_CTRL2);
+
+	mxs_write(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
+		  s, REG_INTR);
+
+	/* Reset FIFO size (it could have changed if DMA was enabled) */
+	u->fifosize = MXS_AUART_FIFO_SIZE;
+
+	/*
+	 * Enable fifo so all four bytes of a DMA word are written to
+	 * output (otherwise, only the LSB is written, ie. 1 in 4 bytes)
+	 */
+	mxs_set(AUART_LINECTRL_FEN, s, REG_LINECTRL);
+
+	/* get initial status of modem lines */
+	mctrl_gpio_get(s->gpios, &s->mctrl_prev);
+
+	s->ms_irq_enabled = false;
+	return 0;
+}
+
+static void mxs_auart_shutdown(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	mxs_auart_disable_ms(u);
+
+	if (auart_dma_enabled(s))
+		mxs_auart_dma_exit(s);
+
+	if (uart_console(u)) {
+		mxs_clr(AUART_CTRL2_UARTEN, s, REG_CTRL2);
+
+		mxs_clr(AUART_INTR_RXIEN | AUART_INTR_RTIEN |
+			AUART_INTR_CTSMIEN, s, REG_INTR);
+		mxs_set(AUART_CTRL0_CLKGATE, s, REG_CTRL0);
+	} else {
+		mxs_auart_reset_assert(s);
+	}
+
+	clk_disable_unprepare(s->clk);
+}
+
+static unsigned int mxs_auart_tx_empty(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	if ((mxs_read(s, REG_STAT) &
+		 (AUART_STAT_TXFE | AUART_STAT_BUSY)) == AUART_STAT_TXFE)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static void mxs_auart_start_tx(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	/* enable transmitter */
+	mxs_set(AUART_CTRL2_TXE, s, REG_CTRL2);
+
+	mxs_auart_tx_chars(s);
+}
+
+static void mxs_auart_stop_tx(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	mxs_clr(AUART_CTRL2_TXE, s, REG_CTRL2);
+}
+
+static void mxs_auart_stop_rx(struct uart_port *u)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	mxs_clr(AUART_CTRL2_RXE, s, REG_CTRL2);
+}
+
+static void mxs_auart_break_ctl(struct uart_port *u, int ctl)
+{
+	struct mxs_auart_port *s = to_auart_port(u);
+
+	if (ctl)
+		mxs_set(AUART_LINECTRL_BRK, s, REG_LINECTRL);
+	else
+		mxs_clr(AUART_LINECTRL_BRK, s, REG_LINECTRL);
+}
+
+static const struct uart_ops mxs_auart_ops = {
+	.tx_empty       = mxs_auart_tx_empty,
+	.start_tx       = mxs_auart_start_tx,
+	.stop_tx	= mxs_auart_stop_tx,
+	.stop_rx	= mxs_auart_stop_rx,
+	.enable_ms      = mxs_auart_enable_ms,
+	.break_ctl      = mxs_auart_break_ctl,
+	.set_mctrl	= mxs_auart_set_mctrl,
+	.get_mctrl      = mxs_auart_get_mctrl,
+	.startup	= mxs_auart_startup,
+	.shutdown       = mxs_auart_shutdown,
+	.set_termios    = mxs_auart_settermios,
+	.set_ldisc      = mxs_auart_set_ldisc,
+	.type	   	= mxs_auart_type,
+	.release_port   = mxs_auart_release_port,
+	.request_port   = mxs_auart_request_port,
+	.config_port    = mxs_auart_config_port,
+	.verify_port    = mxs_auart_verify_port,
+};
+
+static struct mxs_auart_port *auart_port[MXS_AUART_PORTS];
+
+#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
+static void mxs_auart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct mxs_auart_port *s = to_auart_port(port);
+	unsigned int to = 1000;
+
+	while (mxs_read(s, REG_STAT) & AUART_STAT_TXFF) {
+		if (!to--)
+			break;
+		udelay(1);
+	}
+
+	mxs_write(ch, s, REG_DATA);
+}
+
+static void
+auart_console_write(struct console *co, const char *str, unsigned int count)
+{
+	struct mxs_auart_port *s;
+	struct uart_port *port;
+	unsigned int old_ctrl0, old_ctrl2;
+	unsigned int to = 20000;
+
+	if (co->index >= MXS_AUART_PORTS || co->index < 0)
+		return;
+
+	s = auart_port[co->index];
+	port = &s->port;
+
+	clk_enable(s->clk);
+
+	/* First save the CR then disable the interrupts */
+	old_ctrl2 = mxs_read(s, REG_CTRL2);
+	old_ctrl0 = mxs_read(s, REG_CTRL0);
+
+	mxs_clr(AUART_CTRL0_CLKGATE, s, REG_CTRL0);
+	mxs_set(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE, s, REG_CTRL2);
+
+	uart_console_write(port, str, count, mxs_auart_console_putchar);
+
+	/* Finally, wait for transmitter to become empty ... */
+	while (mxs_read(s, REG_STAT) & AUART_STAT_BUSY) {
+		udelay(1);
+		if (!to--)
+			break;
+	}
+
+	/*
+	 * ... and restore the TCR if we waited long enough for the transmitter
+	 * to be idle. This might keep the transmitter enabled although it is
+	 * unused, but that is better than to disable it while it is still
+	 * transmitting.
+	 */
+	if (!(mxs_read(s, REG_STAT) & AUART_STAT_BUSY)) {
+		mxs_write(old_ctrl0, s, REG_CTRL0);
+		mxs_write(old_ctrl2, s, REG_CTRL2);
+	}
+
+	clk_disable(s->clk);
+}
+
+static void __init
+auart_console_get_options(struct mxs_auart_port *s, int *baud,
+			  int *parity, int *bits)
+{
+	struct uart_port *port = &s->port;
+	unsigned int lcr_h, quot;
+
+	if (!(mxs_read(s, REG_CTRL2) & AUART_CTRL2_UARTEN))
+		return;
+
+	lcr_h = mxs_read(s, REG_LINECTRL);
+
+	*parity = 'n';
+	if (lcr_h & AUART_LINECTRL_PEN) {
+		if (lcr_h & AUART_LINECTRL_EPS)
+			*parity = 'e';
+		else
+			*parity = 'o';
+	}
+
+	if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(7))
+		*bits = 7;
+	else
+		*bits = 8;
+
+	quot = ((mxs_read(s, REG_LINECTRL) & AUART_LINECTRL_BAUD_DIVINT_MASK))
+		>> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6);
+	quot |= ((mxs_read(s, REG_LINECTRL) & AUART_LINECTRL_BAUD_DIVFRAC_MASK))
+		>> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT;
+	if (quot == 0)
+		quot = 1;
+
+	*baud = (port->uartclk << 2) / quot;
+}
+
+static int __init
+auart_console_setup(struct console *co, char *options)
+{
+	struct mxs_auart_port *s;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= ARRAY_SIZE(auart_port))
+		co->index = 0;
+	s = auart_port[co->index];
+	if (!s)
+		return -ENODEV;
+
+	ret = clk_prepare_enable(s->clk);
+	if (ret)
+		return ret;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		auart_console_get_options(s, &baud, &parity, &bits);
+
+	ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
+
+	clk_disable_unprepare(s->clk);
+
+	return ret;
+}
+
+static struct console auart_console = {
+	.name		= "ttyAPP",
+	.write		= auart_console_write,
+	.device		= uart_console_device,
+	.setup		= auart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &auart_driver,
+};
+#endif
+
+static struct uart_driver auart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "ttyAPP",
+	.dev_name	= "ttyAPP",
+	.major		= 0,
+	.minor		= 0,
+	.nr		= MXS_AUART_PORTS,
+#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
+	.cons =		&auart_console,
+#endif
+};
+
+static void mxs_init_regs(struct mxs_auart_port *s)
+{
+	if (is_asm9260_auart(s))
+		s->vendor = &vendor_alphascale_asm9260;
+	else
+		s->vendor = &vendor_freescale_stmp37xx;
+}
+
+static int mxs_get_clks(struct mxs_auart_port *s,
+			struct platform_device *pdev)
+{
+	int err;
+
+	if (!is_asm9260_auart(s)) {
+		s->clk = devm_clk_get(&pdev->dev, NULL);
+		return PTR_ERR_OR_ZERO(s->clk);
+	}
+
+	s->clk = devm_clk_get(s->dev, "mod");
+	if (IS_ERR(s->clk)) {
+		dev_err(s->dev, "Failed to get \"mod\" clk\n");
+		return PTR_ERR(s->clk);
+	}
+
+	s->clk_ahb = devm_clk_get(s->dev, "ahb");
+	if (IS_ERR(s->clk_ahb)) {
+		dev_err(s->dev, "Failed to get \"ahb\" clk\n");
+		return PTR_ERR(s->clk_ahb);
+	}
+
+	err = clk_prepare_enable(s->clk_ahb);
+	if (err) {
+		dev_err(s->dev, "Failed to enable ahb_clk!\n");
+		return err;
+	}
+
+	err = clk_set_rate(s->clk, clk_get_rate(s->clk_ahb));
+	if (err) {
+		dev_err(s->dev, "Failed to set rate!\n");
+		goto disable_clk_ahb;
+	}
+
+	err = clk_prepare_enable(s->clk);
+	if (err) {
+		dev_err(s->dev, "Failed to enable clk!\n");
+		goto disable_clk_ahb;
+	}
+
+	return 0;
+
+disable_clk_ahb:
+	clk_disable_unprepare(s->clk_ahb);
+	return err;
+}
+
+static int mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev)
+{
+	enum mctrl_gpio_idx i;
+	struct gpio_desc *gpiod;
+
+	s->gpios = mctrl_gpio_init_noauto(dev, 0);
+	if (IS_ERR(s->gpios))
+		return PTR_ERR(s->gpios);
+
+	/* Block (enabled before) DMA option if RTS or CTS is GPIO line */
+	if (!RTS_AT_AUART() || !CTS_AT_AUART()) {
+		if (test_bit(MXS_AUART_RTSCTS, &s->flags))
+			dev_warn(dev,
+				 "DMA and flow control via gpio may cause some problems. DMA disabled!\n");
+		clear_bit(MXS_AUART_RTSCTS, &s->flags);
+	}
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		gpiod = mctrl_gpio_to_gpiod(s->gpios, i);
+		if (gpiod && (gpiod_get_direction(gpiod) == 1))
+			s->gpio_irq[i] = gpiod_to_irq(gpiod);
+		else
+			s->gpio_irq[i] = -EINVAL;
+	}
+
+	return 0;
+}
+
+static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s)
+{
+	enum mctrl_gpio_idx i;
+
+	for (i = 0; i < UART_GPIO_MAX; i++)
+		if (s->gpio_irq[i] >= 0)
+			free_irq(s->gpio_irq[i], s);
+}
+
+static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s)
+{
+	int *irq = s->gpio_irq;
+	enum mctrl_gpio_idx i;
+	int err = 0;
+
+	for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
+		if (irq[i] < 0)
+			continue;
+
+		irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
+		err = request_irq(irq[i], mxs_auart_irq_handle,
+				IRQ_TYPE_EDGE_BOTH, dev_name(s->dev), s);
+		if (err)
+			dev_err(s->dev, "%s - Can't get %d irq\n",
+				__func__, irq[i]);
+	}
+
+	/*
+	 * If something went wrong, rollback.
+	 * Be careful: i may be unsigned.
+	 */
+	while (err && (i-- > 0))
+		if (irq[i] >= 0)
+			free_irq(irq[i], s);
+
+	return err;
+}
+
+static int mxs_auart_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mxs_auart_port *s;
+	u32 version;
+	int ret, irq;
+	struct resource *r;
+
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	s->port.dev = &pdev->dev;
+	s->dev = &pdev->dev;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
+		return ret;
+	}
+	s->port.line = ret;
+
+	if (of_property_read_bool(np, "uart-has-rtscts") ||
+	    of_property_read_bool(np, "fsl,uart-has-rtscts") /* deprecated */)
+		set_bit(MXS_AUART_RTSCTS, &s->flags);
+
+	if (s->port.line >= ARRAY_SIZE(auart_port)) {
+		dev_err(&pdev->dev, "serial%d out of range\n", s->port.line);
+		return -EINVAL;
+	}
+
+	s->devtype = (enum mxs_auart_type)of_device_get_match_data(&pdev->dev);
+
+	ret = mxs_get_clks(s, pdev);
+	if (ret)
+		return ret;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		ret = -ENXIO;
+		goto out_disable_clks;
+	}
+
+	s->port.mapbase = r->start;
+	s->port.membase = ioremap(r->start, resource_size(r));
+	if (!s->port.membase) {
+		ret = -ENOMEM;
+		goto out_disable_clks;
+	}
+	s->port.ops = &mxs_auart_ops;
+	s->port.iotype = UPIO_MEM;
+	s->port.fifosize = MXS_AUART_FIFO_SIZE;
+	s->port.uartclk = clk_get_rate(s->clk);
+	s->port.type = PORT_IMX;
+	s->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_MXS_AUART_CONSOLE);
+
+	mxs_init_regs(s);
+
+	s->mctrl_prev = 0;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = irq;
+		goto out_iounmap;
+	}
+
+	s->port.irq = irq;
+	ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0,
+			       dev_name(&pdev->dev), s);
+	if (ret)
+		goto out_iounmap;
+
+	platform_set_drvdata(pdev, s);
+
+	ret = mxs_auart_init_gpios(s, &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize GPIOs.\n");
+		goto out_iounmap;
+	}
+
+	/*
+	 * Get the GPIO lines IRQ
+	 */
+	ret = mxs_auart_request_gpio_irq(s);
+	if (ret)
+		goto out_iounmap;
+
+	auart_port[s->port.line] = s;
+
+	mxs_auart_reset_deassert(s);
+
+	ret = uart_add_one_port(&auart_driver, &s->port);
+	if (ret)
+		goto out_free_qpio_irq;
+
+	/* ASM9260 don't have version reg */
+	if (is_asm9260_auart(s)) {
+		dev_info(&pdev->dev, "Found APPUART ASM9260\n");
+	} else {
+		version = mxs_read(s, REG_VERSION);
+		dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n",
+			 (version >> 24) & 0xff,
+			 (version >> 16) & 0xff, version & 0xffff);
+	}
+
+	return 0;
+
+out_free_qpio_irq:
+	mxs_auart_free_gpio_irq(s);
+	auart_port[pdev->id] = NULL;
+
+out_iounmap:
+	iounmap(s->port.membase);
+
+out_disable_clks:
+	if (is_asm9260_auart(s)) {
+		clk_disable_unprepare(s->clk);
+		clk_disable_unprepare(s->clk_ahb);
+	}
+	return ret;
+}
+
+static int mxs_auart_remove(struct platform_device *pdev)
+{
+	struct mxs_auart_port *s = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&auart_driver, &s->port);
+	auart_port[pdev->id] = NULL;
+	mxs_auart_free_gpio_irq(s);
+	iounmap(s->port.membase);
+	if (is_asm9260_auart(s)) {
+		clk_disable_unprepare(s->clk);
+		clk_disable_unprepare(s->clk_ahb);
+	}
+
+	return 0;
+}
+
+static struct platform_driver mxs_auart_driver = {
+	.probe = mxs_auart_probe,
+	.remove = mxs_auart_remove,
+	.driver = {
+		.name = "mxs-auart",
+		.of_match_table = mxs_auart_dt_ids,
+	},
+};
+
+static int __init mxs_auart_init(void)
+{
+	int r;
+
+	r = uart_register_driver(&auart_driver);
+	if (r)
+		goto out;
+
+	r = platform_driver_register(&mxs_auart_driver);
+	if (r)
+		goto out_err;
+
+	return 0;
+out_err:
+	uart_unregister_driver(&auart_driver);
+out:
+	return r;
+}
+
+static void __exit mxs_auart_exit(void)
+{
+	platform_driver_unregister(&mxs_auart_driver);
+	uart_unregister_driver(&auart_driver);
+}
+
+module_init(mxs_auart_init);
+module_exit(mxs_auart_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Freescale MXS application uart driver");
+MODULE_ALIAS("platform:mxs-auart");
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
new file mode 100644
index 000000000..135a838f5
--- /dev/null
+++ b/drivers/tty/serial/omap-serial.c
@@ -0,0 +1,1844 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for OMAP-UART controller.
+ * Based on drivers/serial/8250.c
+ *
+ * Copyright (C) 2010 Texas Instruments.
+ *
+ * Authors:
+ *	Govindraj R	<govindraj.raja@ti.com>
+ *	Thara Gopinath	<thara@ti.com>
+ *
+ * Note: This driver is made separate from 8250 driver as we cannot
+ * over load 8250 driver with omap platform specific configuration for
+ * features like DMA, it makes easier to implement features like DMA and
+ * hardware flow control and software flow control configuration with
+ * this driver as required for the omap-platform.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/serial_core.h>
+#include <linux/irq.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/gpio/consumer.h>
+#include <linux/platform_data/serial-omap.h>
+
+#define OMAP_MAX_HSUART_PORTS	10
+
+#define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
+
+#define OMAP_UART_REV_42 0x0402
+#define OMAP_UART_REV_46 0x0406
+#define OMAP_UART_REV_52 0x0502
+#define OMAP_UART_REV_63 0x0603
+
+#define OMAP_UART_TX_WAKEUP_EN		BIT(7)
+
+/* Feature flags */
+#define OMAP_UART_WER_HAS_TX_WAKEUP	BIT(0)
+
+#define UART_ERRATA_i202_MDR1_ACCESS	BIT(0)
+#define UART_ERRATA_i291_DMA_FORCEIDLE	BIT(1)
+
+#define DEFAULT_CLK_SPEED 48000000 /* 48Mhz */
+
+/* SCR register bitmasks */
+#define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)
+#define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK		(1 << 6)
+#define OMAP_UART_SCR_TX_EMPTY			(1 << 3)
+
+/* FCR register bitmasks */
+#define OMAP_UART_FCR_RX_FIFO_TRIG_MASK			(0x3 << 6)
+#define OMAP_UART_FCR_TX_FIFO_TRIG_MASK			(0x3 << 4)
+
+/* MVR register bitmasks */
+#define OMAP_UART_MVR_SCHEME_SHIFT	30
+
+#define OMAP_UART_LEGACY_MVR_MAJ_MASK	0xf0
+#define OMAP_UART_LEGACY_MVR_MAJ_SHIFT	4
+#define OMAP_UART_LEGACY_MVR_MIN_MASK	0x0f
+
+#define OMAP_UART_MVR_MAJ_MASK		0x700
+#define OMAP_UART_MVR_MAJ_SHIFT		8
+#define OMAP_UART_MVR_MIN_MASK		0x3f
+
+#define OMAP_UART_DMA_CH_FREE	-1
+
+#define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
+#define OMAP_MODE13X_SPEED	230400
+
+/* WER = 0x7F
+ * Enable module level wakeup in WER reg
+ */
+#define OMAP_UART_WER_MOD_WKUP	0x7F
+
+/* Enable XON/XOFF flow control on output */
+#define OMAP_UART_SW_TX		0x08
+
+/* Enable XON/XOFF flow control on input */
+#define OMAP_UART_SW_RX		0x02
+
+#define OMAP_UART_SW_CLR	0xF0
+
+#define OMAP_UART_TCR_TRIG	0x0F
+
+struct uart_omap_dma {
+	u8			uart_dma_tx;
+	u8			uart_dma_rx;
+	int			rx_dma_channel;
+	int			tx_dma_channel;
+	dma_addr_t		rx_buf_dma_phys;
+	dma_addr_t		tx_buf_dma_phys;
+	unsigned int		uart_base;
+	/*
+	 * Buffer for rx dma. It is not required for tx because the buffer
+	 * comes from port structure.
+	 */
+	unsigned char		*rx_buf;
+	unsigned int		prev_rx_dma_pos;
+	int			tx_buf_size;
+	int			tx_dma_used;
+	int			rx_dma_used;
+	spinlock_t		tx_lock;
+	spinlock_t		rx_lock;
+	/* timer to poll activity on rx dma */
+	struct timer_list	rx_timer;
+	unsigned int		rx_buf_size;
+	unsigned int		rx_poll_rate;
+	unsigned int		rx_timeout;
+};
+
+struct uart_omap_port {
+	struct uart_port	port;
+	struct uart_omap_dma	uart_dma;
+	struct device		*dev;
+	int			wakeirq;
+
+	unsigned char		ier;
+	unsigned char		lcr;
+	unsigned char		mcr;
+	unsigned char		fcr;
+	unsigned char		efr;
+	unsigned char		dll;
+	unsigned char		dlh;
+	unsigned char		mdr1;
+	unsigned char		scr;
+	unsigned char		wer;
+
+	int			use_dma;
+	/*
+	 * Some bits in registers are cleared on a read, so they must
+	 * be saved whenever the register is read, but the bits will not
+	 * be immediately processed.
+	 */
+	unsigned int		lsr_break_flag;
+	unsigned char		msr_saved_flags;
+	char			name[20];
+	unsigned long		port_activity;
+	int			context_loss_cnt;
+	u32			errata;
+	u32			features;
+
+	struct gpio_desc	*rts_gpiod;
+
+	struct pm_qos_request	pm_qos_request;
+	u32			latency;
+	u32			calc_latency;
+	struct work_struct	qos_work;
+	bool			is_suspending;
+
+	unsigned int		rs485_tx_filter_count;
+};
+
+#define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
+
+static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
+
+/* Forward declaration of functions */
+static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
+
+static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
+{
+	offset <<= up->port.regshift;
+	return readw(up->port.membase + offset);
+}
+
+static inline void serial_out(struct uart_omap_port *up, int offset, int value)
+{
+	offset <<= up->port.regshift;
+	writew(value, up->port.membase + offset);
+}
+
+static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
+{
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+		       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_FCR, 0);
+}
+
+#ifdef CONFIG_PM
+static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
+{
+	struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
+
+	if (!pdata || !pdata->get_context_loss_count)
+		return -EINVAL;
+
+	return pdata->get_context_loss_count(up->dev);
+}
+
+/* REVISIT: Remove this when omap3 boots in device tree only mode */
+static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
+{
+	struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
+
+	if (!pdata || !pdata->enable_wakeup)
+		return;
+
+	pdata->enable_wakeup(up->dev, enable);
+}
+#endif /* CONFIG_PM */
+
+/*
+ * Calculate the absolute difference between the desired and actual baud
+ * rate for the given mode.
+ */
+static inline int calculate_baud_abs_diff(struct uart_port *port,
+				unsigned int baud, unsigned int mode)
+{
+	unsigned int n = port->uartclk / (mode * baud);
+
+	if (n == 0)
+		n = 1;
+
+	return abs_diff(baud, port->uartclk / (mode * n));
+}
+
+/*
+ * serial_omap_baud_is_mode16 - check if baud rate is MODE16X
+ * @port: uart port info
+ * @baud: baudrate for which mode needs to be determined
+ *
+ * Returns true if baud rate is MODE16X and false if MODE13X
+ * Original table in OMAP TRM named "UART Mode Baud Rates, Divisor Values,
+ * and Error Rates" determines modes not for all common baud rates.
+ * E.g. for 1000000 baud rate mode must be 16x, but according to that
+ * table it's determined as 13x.
+ */
+static bool
+serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
+{
+	int abs_diff_13 = calculate_baud_abs_diff(port, baud, 13);
+	int abs_diff_16 = calculate_baud_abs_diff(port, baud, 16);
+
+	return (abs_diff_13 >= abs_diff_16);
+}
+
+/*
+ * serial_omap_get_divisor - calculate divisor value
+ * @port: uart port info
+ * @baud: baudrate for which divisor needs to be calculated.
+ */
+static unsigned int
+serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
+{
+	unsigned int mode;
+
+	if (!serial_omap_baud_is_mode16(port, baud))
+		mode = 13;
+	else
+		mode = 16;
+	return port->uartclk/(mode * baud);
+}
+
+static void serial_omap_enable_ms(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+
+	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line);
+
+	up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void serial_omap_stop_tx(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	int res;
+
+	/* Handle RS-485 */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if (up->scr & OMAP_UART_SCR_TX_EMPTY) {
+			/* THR interrupt is fired when both TX FIFO and TX
+			 * shift register are empty. This means there's nothing
+			 * left to transmit now, so make sure the THR interrupt
+			 * is fired when TX FIFO is below the trigger level,
+			 * disable THR interrupts and toggle the RS-485 GPIO
+			 * data direction pin if needed.
+			 */
+			up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
+			serial_out(up, UART_OMAP_SCR, up->scr);
+			res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
+				1 : 0;
+			if (gpiod_get_value(up->rts_gpiod) != res) {
+				if (port->rs485.delay_rts_after_send > 0)
+					mdelay(
+					port->rs485.delay_rts_after_send);
+				gpiod_set_value(up->rts_gpiod, res);
+			}
+		} else {
+			/* We're asked to stop, but there's still stuff in the
+			 * UART FIFO, so make sure the THR interrupt is fired
+			 * when both TX FIFO and TX shift register are empty.
+			 * The next THR interrupt (if no transmission is started
+			 * in the meantime) will indicate the end of a
+			 * transmission. Therefore we _don't_ disable THR
+			 * interrupts in this situation.
+			 */
+			up->scr |= OMAP_UART_SCR_TX_EMPTY;
+			serial_out(up, UART_OMAP_SCR, up->scr);
+			return;
+		}
+	}
+
+	if (up->ier & UART_IER_THRI) {
+		up->ier &= ~UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static void serial_omap_stop_rx(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+
+	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void serial_omap_put_char(struct uart_omap_port *up, unsigned char ch)
+{
+	serial_out(up, UART_TX, ch);
+
+	if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+			!(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
+		up->rs485_tx_filter_count++;
+}
+
+static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
+{
+	u8 ch;
+
+	uart_port_tx_limited(&up->port, ch, up->port.fifosize / 4,
+		true,
+		serial_omap_put_char(up, ch),
+		({}));
+}
+
+static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
+{
+	if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static void serial_omap_start_tx(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	int res;
+
+	/* Handle RS-485 */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		/* Fire THR interrupts when FIFO is below trigger level */
+		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
+		serial_out(up, UART_OMAP_SCR, up->scr);
+
+		/* if rts not already enabled */
+		res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
+		if (gpiod_get_value(up->rts_gpiod) != res) {
+			gpiod_set_value(up->rts_gpiod, res);
+			if (port->rs485.delay_rts_before_send > 0)
+				mdelay(port->rs485.delay_rts_before_send);
+		}
+	}
+
+	if ((port->rs485.flags & SER_RS485_ENABLED) &&
+	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
+		up->rs485_tx_filter_count = 0;
+
+	serial_omap_enable_ier_thri(up);
+}
+
+static void serial_omap_throttle(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void serial_omap_unthrottle(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->ier |= UART_IER_RLSI | UART_IER_RDI;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static unsigned int check_modem_status(struct uart_omap_port *up)
+{
+	unsigned int status;
+
+	status = serial_in(up, UART_MSR);
+	status |= up->msr_saved_flags;
+	up->msr_saved_flags = 0;
+	if ((status & UART_MSR_ANY_DELTA) == 0)
+		return status;
+
+	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
+	    up->port.state != NULL) {
+		if (status & UART_MSR_TERI)
+			up->port.icount.rng++;
+		if (status & UART_MSR_DDSR)
+			up->port.icount.dsr++;
+		if (status & UART_MSR_DDCD)
+			uart_handle_dcd_change
+				(&up->port, status & UART_MSR_DCD);
+		if (status & UART_MSR_DCTS)
+			uart_handle_cts_change
+				(&up->port, status & UART_MSR_CTS);
+		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+	}
+
+	return status;
+}
+
+static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
+{
+	u8 flag;
+
+	/*
+	 * Read one data character out to avoid stalling the receiver according
+	 * to the table 23-246 of the omap4 TRM.
+	 */
+	if (likely(lsr & UART_LSR_DR)) {
+		serial_in(up, UART_RX);
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
+		    up->rs485_tx_filter_count)
+			up->rs485_tx_filter_count--;
+	}
+
+	up->port.icount.rx++;
+	flag = TTY_NORMAL;
+
+	if (lsr & UART_LSR_BI) {
+		flag = TTY_BREAK;
+		lsr &= ~(UART_LSR_FE | UART_LSR_PE);
+		up->port.icount.brk++;
+		/*
+		 * We do the SysRQ and SAK checking
+		 * here because otherwise the break
+		 * may get masked by ignore_status_mask
+		 * or read_status_mask.
+		 */
+		if (uart_handle_break(&up->port))
+			return;
+
+	}
+
+	if (lsr & UART_LSR_PE) {
+		flag = TTY_PARITY;
+		up->port.icount.parity++;
+	}
+
+	if (lsr & UART_LSR_FE) {
+		flag = TTY_FRAME;
+		up->port.icount.frame++;
+	}
+
+	if (lsr & UART_LSR_OE)
+		up->port.icount.overrun++;
+
+#ifdef CONFIG_SERIAL_OMAP_CONSOLE
+	if (up->port.line == up->port.cons->index) {
+		/* Recover the break flag from console xmit */
+		lsr |= up->lsr_break_flag;
+	}
+#endif
+	uart_insert_char(&up->port, lsr, UART_LSR_OE, 0, flag);
+}
+
+static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
+{
+	u8 ch;
+
+	if (!(lsr & UART_LSR_DR))
+		return;
+
+	ch = serial_in(up, UART_RX);
+	if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+	    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
+	    up->rs485_tx_filter_count) {
+		up->rs485_tx_filter_count--;
+		return;
+	}
+
+	up->port.icount.rx++;
+
+	if (uart_handle_sysrq_char(&up->port, ch))
+		return;
+
+	uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, TTY_NORMAL);
+}
+
+/**
+ * serial_omap_irq() - This handles the interrupt from one port
+ * @irq: uart port irq number
+ * @dev_id: uart port info
+ */
+static irqreturn_t serial_omap_irq(int irq, void *dev_id)
+{
+	struct uart_omap_port *up = dev_id;
+	unsigned int iir, lsr;
+	unsigned int type;
+	irqreturn_t ret = IRQ_NONE;
+	int max_count = 256;
+
+	spin_lock(&up->port.lock);
+
+	do {
+		iir = serial_in(up, UART_IIR);
+		if (iir & UART_IIR_NO_INT)
+			break;
+
+		ret = IRQ_HANDLED;
+		lsr = serial_in(up, UART_LSR);
+
+		/* extract IRQ type from IIR register */
+		type = iir & 0x3e;
+
+		switch (type) {
+		case UART_IIR_MSI:
+			check_modem_status(up);
+			break;
+		case UART_IIR_THRI:
+			transmit_chars(up, lsr);
+			break;
+		case UART_IIR_RX_TIMEOUT:
+		case UART_IIR_RDI:
+			serial_omap_rdi(up, lsr);
+			break;
+		case UART_IIR_RLSI:
+			serial_omap_rlsi(up, lsr);
+			break;
+		case UART_IIR_CTS_RTS_DSR:
+			/* simply try again */
+			break;
+		case UART_IIR_XOFF:
+		default:
+			break;
+		}
+	} while (max_count--);
+
+	spin_unlock(&up->port.lock);
+
+	tty_flip_buffer_push(&up->port.state->port);
+
+	up->port_activity = jiffies;
+
+	return ret;
+}
+
+static unsigned int serial_omap_tx_empty(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+	unsigned int ret = 0;
+
+	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
+	spin_lock_irqsave(&up->port.lock, flags);
+	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return ret;
+}
+
+static unsigned int serial_omap_get_mctrl(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned int status;
+	unsigned int ret = 0;
+
+	status = check_modem_status(up);
+
+	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line);
+
+	if (status & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+	if (status & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+	if (status & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+	if (status & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned char mcr = 0, old_mcr, lcr;
+
+	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (mctrl & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	old_mcr = serial_in(up, UART_MCR);
+	old_mcr &= ~(UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_OUT1 |
+		     UART_MCR_DTR | UART_MCR_RTS);
+	up->mcr = old_mcr | mcr;
+	serial_out(up, UART_MCR, up->mcr);
+
+	/* Turn off autoRTS if RTS is lowered; restore autoRTS if RTS raised */
+	lcr = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+		up->efr |= UART_EFR_RTS;
+	else
+		up->efr &= ~UART_EFR_RTS;
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, lcr);
+}
+
+static void serial_omap_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+
+	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_out(up, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int serial_omap_startup(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+	int retval;
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
+				up->name, up);
+	if (retval)
+		return retval;
+
+	/* Optional wake-up IRQ */
+	if (up->wakeirq) {
+		retval = dev_pm_set_dedicated_wake_irq(up->dev, up->wakeirq);
+		if (retval) {
+			free_irq(up->port.irq, up);
+			return retval;
+		}
+	}
+
+	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
+
+	pm_runtime_get_sync(up->dev);
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	serial_omap_clear_fifos(up);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) serial_in(up, UART_LSR);
+	if (serial_in(up, UART_LSR) & UART_LSR_DR)
+		(void) serial_in(up, UART_RX);
+	(void) serial_in(up, UART_IIR);
+	(void) serial_in(up, UART_MSR);
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
+	spin_lock_irqsave(&up->port.lock, flags);
+	/*
+	 * Most PC uarts need OUT2 raised to enable interrupts.
+	 */
+	up->port.mctrl |= TIOCM_OUT2;
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	up->msr_saved_flags = 0;
+	/*
+	 * Finally, enable interrupts. Note: Modem status interrupts
+	 * are set via set_termios(), which will be occurring imminently
+	 * anyway, so we don't enable them here.
+	 */
+	up->ier = UART_IER_RLSI | UART_IER_RDI;
+	serial_out(up, UART_IER, up->ier);
+
+	/* Enable module level wake up */
+	up->wer = OMAP_UART_WER_MOD_WKUP;
+	if (up->features & OMAP_UART_WER_HAS_TX_WAKEUP)
+		up->wer |= OMAP_UART_TX_WAKEUP_EN;
+
+	serial_out(up, UART_OMAP_WER, up->wer);
+
+	up->port_activity = jiffies;
+	return 0;
+}
+
+static void serial_omap_shutdown(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+
+	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line);
+
+	/*
+	 * Disable interrupts from this port
+	 */
+	up->ier = 0;
+	serial_out(up, UART_IER, 0);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->port.mctrl &= ~TIOCM_OUT2;
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
+	serial_omap_clear_fifos(up);
+
+	/*
+	 * Read data port to reset things, and then free the irq
+	 */
+	if (serial_in(up, UART_LSR) & UART_LSR_DR)
+		(void) serial_in(up, UART_RX);
+
+	pm_runtime_put_sync(up->dev);
+	free_irq(up->port.irq, up);
+	dev_pm_clear_wake_irq(up->dev);
+}
+
+static void serial_omap_uart_qos_work(struct work_struct *work)
+{
+	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
+						qos_work);
+
+	cpu_latency_qos_update_request(&up->pm_qos_request, up->latency);
+}
+
+static void
+serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
+			const struct ktermios *old)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned char cval = 0;
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+	if (termios->c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (termios->c_cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(termios->c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	if (termios->c_cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
+	quot = serial_omap_get_divisor(port, baud);
+
+	/* calculate wakeup latency constraint */
+	up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8);
+	up->latency = up->calc_latency;
+	schedule_work(&up->qos_work);
+
+	up->dll = quot & 0xff;
+	up->dlh = quot >> 8;
+	up->mdr1 = UART_OMAP_MDR1_DISABLE;
+
+	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
+			UART_FCR_ENABLE_FIFO;
+
+	/*
+	 * Ok, we're now changing the port state. Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		up->port.read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * Modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+	serial_out(up, UART_LCR, cval);		/* reset DLAB */
+	up->lcr = cval;
+	up->scr = 0;
+
+	/* FIFOs and DMA Settings */
+
+	/* FCR can be changed only when the
+	 * baud clock is not running
+	 * DLL_REG and DLH_REG set to 0.
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_DLL, 0);
+	serial_out(up, UART_DLM, 0);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	up->efr = serial_in(up, UART_EFR) & ~UART_EFR_ECB;
+	up->efr &= ~UART_EFR_SCD;
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	up->mcr = serial_in(up, UART_MCR) & ~UART_MCR_TCRTLR;
+	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+	/* FIFO ENABLE, DMA MODE */
+
+	up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
+	/*
+	 * NOTE: Setting OMAP_UART_SCR_RX_TRIG_GRANU1_MASK
+	 * sets Enables the granularity of 1 for TRIGGER RX
+	 * level. Along with setting RX FIFO trigger level
+	 * to 1 (as noted below, 16 characters) and TLR[3:0]
+	 * to zero this will result RX FIFO threshold level
+	 * to 1 character, instead of 16 as noted in comment
+	 * below.
+	 */
+
+	/* Set receive FIFO threshold to 16 characters and
+	 * transmit FIFO threshold to 32 spaces
+	 */
+	up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
+	up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK;
+	up->fcr |= UART_FCR6_R_TRIGGER_16 | UART_FCR6_T_TRIGGER_24 |
+		UART_FCR_ENABLE_FIFO;
+
+	serial_out(up, UART_FCR, up->fcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	serial_out(up, UART_OMAP_SCR, up->scr);
+
+	/* Reset UART_MCR_TCRTLR: this must be done with the EFR_ECB bit set */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_MCR, up->mcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+
+	/* Protocol, Baud Rate, and Interrupt Settings */
+
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, up->mdr1);
+	else
+		serial_out(up, UART_OMAP_MDR1, up->mdr1);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+
+	serial_out(up, UART_LCR, 0);
+	serial_out(up, UART_IER, 0);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	serial_out(up, UART_DLL, up->dll);	/* LS of divisor */
+	serial_out(up, UART_DLM, up->dlh);	/* MS of divisor */
+
+	serial_out(up, UART_LCR, 0);
+	serial_out(up, UART_IER, up->ier);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, cval);
+
+	if (!serial_omap_baud_is_mode16(port, baud))
+		up->mdr1 = UART_OMAP_MDR1_13X_MODE;
+	else
+		up->mdr1 = UART_OMAP_MDR1_16X_MODE;
+
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, up->mdr1);
+	else
+		serial_out(up, UART_OMAP_MDR1, up->mdr1);
+
+	/* Configure flow control */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	/* XON1/XOFF1 accessible mode B, TCRTLR=0, ECB=0 */
+	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
+	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
+
+	/* Enable access to TCR/TLR */
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+
+	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
+
+	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
+
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
+		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+		up->efr |= UART_EFR_CTS;
+	} else {
+		/* Disable AUTORTS and AUTOCTS */
+		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
+	}
+
+	if (up->port.flags & UPF_SOFT_FLOW) {
+		/* clear SW control mode bits */
+		up->efr &= OMAP_UART_SW_CLR;
+
+		/*
+		 * IXON Flag:
+		 * Enable XON/XOFF flow control on input.
+		 * Receiver compares XON1, XOFF1.
+		 */
+		if (termios->c_iflag & IXON)
+			up->efr |= OMAP_UART_SW_RX;
+
+		/*
+		 * IXOFF Flag:
+		 * Enable XON/XOFF flow control on output.
+		 * Transmit XON1, XOFF1
+		 */
+		if (termios->c_iflag & IXOFF) {
+			up->port.status |= UPSTAT_AUTOXOFF;
+			up->efr |= OMAP_UART_SW_TX;
+		}
+
+		/*
+		 * IXANY Flag:
+		 * Enable any character to restart output.
+		 * Operation resumes after receiving any
+		 * character after recognition of the XOFF character
+		 */
+		if (termios->c_iflag & IXANY)
+			up->mcr |= UART_MCR_XONANY;
+		else
+			up->mcr &= ~UART_MCR_XONANY;
+	}
+	serial_out(up, UART_MCR, up->mcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, up->lcr);
+
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
+}
+
+static void
+serial_omap_pm(struct uart_port *port, unsigned int state,
+	       unsigned int oldstate)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned char efr;
+
+	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, efr);
+	serial_out(up, UART_LCR, 0);
+}
+
+static void serial_omap_release_port(struct uart_port *port)
+{
+	dev_dbg(port->dev, "serial_omap_release_port+\n");
+}
+
+static int serial_omap_request_port(struct uart_port *port)
+{
+	dev_dbg(port->dev, "serial_omap_request_port+\n");
+	return 0;
+}
+
+static void serial_omap_config_port(struct uart_port *port, int flags)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+
+	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
+							up->port.line);
+	up->port.type = PORT_OMAP;
+	up->port.flags |= UPF_SOFT_FLOW | UPF_HARD_FLOW;
+}
+
+static int
+serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* we don't want the core code to modify any port params */
+	dev_dbg(port->dev, "serial_omap_verify_port+\n");
+	return -EINVAL;
+}
+
+static const char *
+serial_omap_type(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+
+	dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line);
+	return up->name;
+}
+
+static void __maybe_unused wait_for_xmitr(struct uart_omap_port *up)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	do {
+		status = serial_in(up, UART_LSR);
+
+		if (status & UART_LSR_BI)
+			up->lsr_break_flag = UART_LSR_BI;
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (!uart_lsr_tx_empty(status));
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		for (tmout = 1000000; tmout; tmout--) {
+			unsigned int msr = serial_in(up, UART_MSR);
+
+			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
+			if (msr & UART_MSR_CTS)
+				break;
+
+			udelay(1);
+		}
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+
+	wait_for_xmitr(up);
+	serial_out(up, UART_TX, ch);
+}
+
+static int serial_omap_poll_get_char(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned int status;
+
+	status = serial_in(up, UART_LSR);
+	if (!(status & UART_LSR_DR)) {
+		status = NO_POLL_CHAR;
+		goto out;
+	}
+
+	status = serial_in(up, UART_RX);
+
+out:
+	return status;
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+#ifdef CONFIG_SERIAL_OMAP_CONSOLE
+
+#ifdef CONFIG_SERIAL_EARLYCON
+static unsigned int omap_serial_early_in(struct uart_port *port, int offset)
+{
+	offset <<= port->regshift;
+	return readw(port->membase + offset);
+}
+
+static void omap_serial_early_out(struct uart_port *port, int offset,
+				  int value)
+{
+	offset <<= port->regshift;
+	writew(value, port->membase + offset);
+}
+
+static void omap_serial_early_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned int status;
+
+	for (;;) {
+		status = omap_serial_early_in(port, UART_LSR);
+		if (uart_lsr_tx_empty(status))
+			break;
+		cpu_relax();
+	}
+	omap_serial_early_out(port, UART_TX, c);
+}
+
+static void early_omap_serial_write(struct console *console, const char *s,
+				    unsigned int count)
+{
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+
+	uart_console_write(port, s, count, omap_serial_early_putc);
+}
+
+static int __init early_omap_serial_setup(struct earlycon_device *device,
+					  const char *options)
+{
+	struct uart_port *port = &device->port;
+
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+
+	port->regshift = 2;
+	device->con->write = early_omap_serial_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(omapserial, "ti,omap2-uart", early_omap_serial_setup);
+OF_EARLYCON_DECLARE(omapserial, "ti,omap3-uart", early_omap_serial_setup);
+OF_EARLYCON_DECLARE(omapserial, "ti,omap4-uart", early_omap_serial_setup);
+#endif /* CONFIG_SERIAL_EARLYCON */
+
+static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
+
+static struct uart_driver serial_omap_reg;
+
+static void serial_omap_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+
+	wait_for_xmitr(up);
+	serial_out(up, UART_TX, ch);
+}
+
+static void
+serial_omap_console_write(struct console *co, const char *s,
+		unsigned int count)
+{
+	struct uart_omap_port *up = serial_omap_console_ports[co->index];
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	local_irq_save(flags);
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&up->port.lock);
+	else
+		spin_lock(&up->port.lock);
+
+	/*
+	 * First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, 0);
+
+	uart_console_write(&up->port, s, count, serial_omap_console_putchar);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, UART_IER, ier);
+	/*
+	 * The receive handling will happen properly because the
+	 * receive ready bit will still be set; it is not cleared
+	 * on read.  However, modem control will not, we must
+	 * call it if we have saved something in the saved flags
+	 * while processing with interrupts off.
+	 */
+	if (up->msr_saved_flags)
+		check_modem_status(up);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+	local_irq_restore(flags);
+}
+
+static int __init
+serial_omap_console_setup(struct console *co, char *options)
+{
+	struct uart_omap_port *up;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (serial_omap_console_ports[co->index] == NULL)
+		return -ENODEV;
+	up = serial_omap_console_ports[co->index];
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&up->port, co, baud, parity, bits, flow);
+}
+
+static struct console serial_omap_console = {
+	.name		= OMAP_SERIAL_NAME,
+	.write		= serial_omap_console_write,
+	.device		= uart_console_device,
+	.setup		= serial_omap_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial_omap_reg,
+};
+
+static void serial_omap_add_console_port(struct uart_omap_port *up)
+{
+	serial_omap_console_ports[up->port.line] = up;
+}
+
+#define OMAP_CONSOLE	(&serial_omap_console)
+
+#else
+
+#define OMAP_CONSOLE	NULL
+
+static inline void serial_omap_add_console_port(struct uart_omap_port *up)
+{}
+
+#endif
+
+/* Enable or disable the rs485 support */
+static int
+serial_omap_config_rs485(struct uart_port *port, struct ktermios *termios,
+			 struct serial_rs485 *rs485)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned int mode;
+	int val;
+
+	/* Disable interrupts from this port */
+	mode = up->ier;
+	up->ier = 0;
+	serial_out(up, UART_IER, 0);
+
+	/* enable / disable rts */
+	val = (rs485->flags & SER_RS485_ENABLED) ?
+	      SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
+	val = (rs485->flags & val) ? 1 : 0;
+	gpiod_set_value(up->rts_gpiod, val);
+
+	/* Enable interrupts */
+	up->ier = mode;
+	serial_out(up, UART_IER, up->ier);
+
+	/* If RS-485 is disabled, make sure the THR interrupt is fired when
+	 * TX FIFO is below the trigger level.
+	 */
+	if (!(rs485->flags & SER_RS485_ENABLED) &&
+	    (up->scr & OMAP_UART_SCR_TX_EMPTY)) {
+		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
+		serial_out(up, UART_OMAP_SCR, up->scr);
+	}
+
+	return 0;
+}
+
+static const struct uart_ops serial_omap_pops = {
+	.tx_empty	= serial_omap_tx_empty,
+	.set_mctrl	= serial_omap_set_mctrl,
+	.get_mctrl	= serial_omap_get_mctrl,
+	.stop_tx	= serial_omap_stop_tx,
+	.start_tx	= serial_omap_start_tx,
+	.throttle	= serial_omap_throttle,
+	.unthrottle	= serial_omap_unthrottle,
+	.stop_rx	= serial_omap_stop_rx,
+	.enable_ms	= serial_omap_enable_ms,
+	.break_ctl	= serial_omap_break_ctl,
+	.startup	= serial_omap_startup,
+	.shutdown	= serial_omap_shutdown,
+	.set_termios	= serial_omap_set_termios,
+	.pm		= serial_omap_pm,
+	.type		= serial_omap_type,
+	.release_port	= serial_omap_release_port,
+	.request_port	= serial_omap_request_port,
+	.config_port	= serial_omap_config_port,
+	.verify_port	= serial_omap_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_put_char  = serial_omap_poll_put_char,
+	.poll_get_char  = serial_omap_poll_get_char,
+#endif
+};
+
+static struct uart_driver serial_omap_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "OMAP-SERIAL",
+	.dev_name	= OMAP_SERIAL_NAME,
+	.nr		= OMAP_MAX_HSUART_PORTS,
+	.cons		= OMAP_CONSOLE,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int serial_omap_prepare(struct device *dev)
+{
+	struct uart_omap_port *up = dev_get_drvdata(dev);
+
+	up->is_suspending = true;
+
+	return 0;
+}
+
+static void serial_omap_complete(struct device *dev)
+{
+	struct uart_omap_port *up = dev_get_drvdata(dev);
+
+	up->is_suspending = false;
+}
+
+static int serial_omap_suspend(struct device *dev)
+{
+	struct uart_omap_port *up = dev_get_drvdata(dev);
+
+	uart_suspend_port(&serial_omap_reg, &up->port);
+	flush_work(&up->qos_work);
+
+	if (device_may_wakeup(dev))
+		serial_omap_enable_wakeup(up, true);
+	else
+		serial_omap_enable_wakeup(up, false);
+
+	return 0;
+}
+
+static int serial_omap_resume(struct device *dev)
+{
+	struct uart_omap_port *up = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		serial_omap_enable_wakeup(up, false);
+
+	uart_resume_port(&serial_omap_reg, &up->port);
+
+	return 0;
+}
+#else
+#define serial_omap_prepare NULL
+#define serial_omap_complete NULL
+#endif /* CONFIG_PM_SLEEP */
+
+static void omap_serial_fill_features_erratas(struct uart_omap_port *up)
+{
+	u32 mvr, scheme;
+	u16 revision, major, minor;
+
+	mvr = readl(up->port.membase + (UART_OMAP_MVER << up->port.regshift));
+
+	/* Check revision register scheme */
+	scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
+
+	switch (scheme) {
+	case 0: /* Legacy Scheme: OMAP2/3 */
+		/* MINOR_REV[0:4], MAJOR_REV[4:7] */
+		major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
+					OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
+		minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
+		break;
+	case 1:
+		/* New Scheme: OMAP4+ */
+		/* MINOR_REV[0:5], MAJOR_REV[8:10] */
+		major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
+					OMAP_UART_MVR_MAJ_SHIFT;
+		minor = (mvr & OMAP_UART_MVR_MIN_MASK);
+		break;
+	default:
+		dev_warn(up->dev,
+			"Unknown %s revision, defaulting to highest\n",
+			up->name);
+		/* highest possible revision */
+		major = 0xff;
+		minor = 0xff;
+	}
+
+	/* normalize revision for the driver */
+	revision = UART_BUILD_REVISION(major, minor);
+
+	switch (revision) {
+	case OMAP_UART_REV_46:
+		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
+				UART_ERRATA_i291_DMA_FORCEIDLE);
+		break;
+	case OMAP_UART_REV_52:
+		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
+				UART_ERRATA_i291_DMA_FORCEIDLE);
+		up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
+		break;
+	case OMAP_UART_REV_63:
+		up->errata |= UART_ERRATA_i202_MDR1_ACCESS;
+		up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
+		break;
+	default:
+		break;
+	}
+}
+
+static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
+{
+	struct omap_uart_port_info *omap_up_info;
+
+	omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL);
+	if (!omap_up_info)
+		return NULL; /* out of memory */
+
+	of_property_read_u32(dev->of_node, "clock-frequency",
+					 &omap_up_info->uartclk);
+
+	omap_up_info->flags = UPF_BOOT_AUTOCONF;
+
+	return omap_up_info;
+}
+
+static const struct serial_rs485 serial_omap_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+		 SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+static int serial_omap_probe_rs485(struct uart_omap_port *up,
+				   struct device *dev)
+{
+	struct serial_rs485 *rs485conf = &up->port.rs485;
+	struct device_node *np = dev->of_node;
+	enum gpiod_flags gflags;
+	int ret;
+
+	rs485conf->flags = 0;
+	up->rts_gpiod = NULL;
+
+	if (!np)
+		return 0;
+
+	up->port.rs485_config = serial_omap_config_rs485;
+	up->port.rs485_supported = serial_omap_rs485_supported;
+
+	ret = uart_get_rs485_mode(&up->port);
+	if (ret)
+		return ret;
+
+	if (of_property_read_bool(np, "rs485-rts-active-high")) {
+		rs485conf->flags |= SER_RS485_RTS_ON_SEND;
+		rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
+	} else {
+		rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
+		rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+	}
+
+	/* check for tx enable gpio */
+	gflags = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ?
+		GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	up->rts_gpiod = devm_gpiod_get_optional(dev, "rts", gflags);
+	if (IS_ERR(up->rts_gpiod)) {
+		ret = PTR_ERR(up->rts_gpiod);
+	        if (ret == -EPROBE_DEFER)
+			return ret;
+
+		up->rts_gpiod = NULL;
+		up->port.rs485_supported = (const struct serial_rs485) { };
+		if (rs485conf->flags & SER_RS485_ENABLED) {
+			dev_err(dev, "disabling RS-485 (rts-gpio missing in device tree)\n");
+			memset(rs485conf, 0, sizeof(*rs485conf));
+		}
+	} else {
+		gpiod_set_consumer_name(up->rts_gpiod, "omap-serial");
+	}
+
+	return 0;
+}
+
+static int serial_omap_probe(struct platform_device *pdev)
+{
+	struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
+	struct uart_omap_port *up;
+	struct resource *mem;
+	void __iomem *base;
+	int uartirq = 0;
+	int wakeirq = 0;
+	int ret;
+
+	/* The optional wakeirq may be specified in the board dts file */
+	if (pdev->dev.of_node) {
+		uartirq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+		if (!uartirq)
+			return -EPROBE_DEFER;
+		wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
+		omap_up_info = of_get_uart_port_info(&pdev->dev);
+		pdev->dev.platform_data = omap_up_info;
+	} else {
+		uartirq = platform_get_irq(pdev, 0);
+		if (uartirq < 0)
+			return -EPROBE_DEFER;
+	}
+
+	up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL);
+	if (!up)
+		return -ENOMEM;
+
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	up->dev = &pdev->dev;
+	up->port.dev = &pdev->dev;
+	up->port.type = PORT_OMAP;
+	up->port.iotype = UPIO_MEM;
+	up->port.irq = uartirq;
+	up->port.regshift = 2;
+	up->port.fifosize = 64;
+	up->port.ops = &serial_omap_pops;
+	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_OMAP_CONSOLE);
+
+	if (pdev->dev.of_node)
+		ret = of_alias_get_id(pdev->dev.of_node, "serial");
+	else
+		ret = pdev->id;
+
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
+			ret);
+		goto err_port_line;
+	}
+	up->port.line = ret;
+
+	if (up->port.line >= OMAP_MAX_HSUART_PORTS) {
+		dev_err(&pdev->dev, "uart ID %d >  MAX %d.\n", up->port.line,
+			OMAP_MAX_HSUART_PORTS);
+		ret = -ENXIO;
+		goto err_port_line;
+	}
+
+	up->wakeirq = wakeirq;
+	if (!up->wakeirq)
+		dev_info(up->port.dev, "no wakeirq for uart%d\n",
+			 up->port.line);
+
+	sprintf(up->name, "OMAP UART%d", up->port.line);
+	up->port.mapbase = mem->start;
+	up->port.membase = base;
+	up->port.flags = omap_up_info->flags;
+	up->port.uartclk = omap_up_info->uartclk;
+	if (!up->port.uartclk) {
+		up->port.uartclk = DEFAULT_CLK_SPEED;
+		dev_warn(&pdev->dev,
+			 "No clock speed specified: using default: %d\n",
+			 DEFAULT_CLK_SPEED);
+	}
+
+	ret = serial_omap_probe_rs485(up, &pdev->dev);
+	if (ret < 0)
+		goto err_rs485;
+
+	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	cpu_latency_qos_add_request(&up->pm_qos_request, up->latency);
+	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
+
+	platform_set_drvdata(pdev, up);
+	if (omap_up_info->autosuspend_timeout == 0)
+		omap_up_info->autosuspend_timeout = -1;
+
+	device_init_wakeup(up->dev, true);
+
+	pm_runtime_enable(&pdev->dev);
+
+	pm_runtime_get_sync(&pdev->dev);
+
+	omap_serial_fill_features_erratas(up);
+
+	ui[up->port.line] = up;
+	serial_omap_add_console_port(up);
+
+	ret = uart_add_one_port(&serial_omap_reg, &up->port);
+	if (ret != 0)
+		goto err_add_port;
+
+	return 0;
+
+err_add_port:
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	cpu_latency_qos_remove_request(&up->pm_qos_request);
+	device_init_wakeup(up->dev, false);
+err_rs485:
+err_port_line:
+	return ret;
+}
+
+static int serial_omap_remove(struct platform_device *dev)
+{
+	struct uart_omap_port *up = platform_get_drvdata(dev);
+
+	pm_runtime_get_sync(up->dev);
+
+	uart_remove_one_port(&serial_omap_reg, &up->port);
+
+	pm_runtime_put_sync(up->dev);
+	pm_runtime_disable(up->dev);
+	cpu_latency_qos_remove_request(&up->pm_qos_request);
+	device_init_wakeup(&dev->dev, false);
+
+	return 0;
+}
+
+/*
+ * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
+ * The access to uart register after MDR1 Access
+ * causes UART to corrupt data.
+ *
+ * Need a delay =
+ * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
+ * give 10 times as much
+ */
+static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
+{
+	u8 timeout = 255;
+
+	serial_out(up, UART_OMAP_MDR1, mdr1);
+	udelay(2);
+	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
+			UART_FCR_CLEAR_RCVR);
+	/*
+	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
+	 * TX_FIFO_E bit is 1.
+	 */
+	while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
+				(UART_LSR_THRE | UART_LSR_DR))) {
+		timeout--;
+		if (!timeout) {
+			/* Should *never* happen. we warn and carry on */
+			dev_crit(up->dev, "Errata i202: timedout %x\n",
+						serial_in(up, UART_LSR));
+			break;
+		}
+		udelay(1);
+	}
+}
+
+#ifdef CONFIG_PM
+static void serial_omap_restore_context(struct uart_omap_port *up)
+{
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
+	else
+		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
+	serial_out(up, UART_EFR, UART_EFR_ECB);
+	serial_out(up, UART_LCR, 0x0); /* Operational mode */
+	serial_out(up, UART_IER, 0x0);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
+	serial_out(up, UART_DLL, up->dll);
+	serial_out(up, UART_DLM, up->dlh);
+	serial_out(up, UART_LCR, 0x0); /* Operational mode */
+	serial_out(up, UART_IER, up->ier);
+	serial_out(up, UART_FCR, up->fcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_MCR, up->mcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
+	serial_out(up, UART_OMAP_SCR, up->scr);
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, up->lcr);
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, up->mdr1);
+	else
+		serial_out(up, UART_OMAP_MDR1, up->mdr1);
+	serial_out(up, UART_OMAP_WER, up->wer);
+}
+
+static int serial_omap_runtime_suspend(struct device *dev)
+{
+	struct uart_omap_port *up = dev_get_drvdata(dev);
+
+	if (!up)
+		return -EINVAL;
+
+	/*
+	* When using 'no_console_suspend', the console UART must not be
+	* suspended. Since driver suspend is managed by runtime suspend,
+	* preventing runtime suspend (by returning error) will keep device
+	* active during suspend.
+	*/
+	if (up->is_suspending && !console_suspend_enabled &&
+	    uart_console(&up->port))
+		return -EBUSY;
+
+	up->context_loss_cnt = serial_omap_get_context_loss_count(up);
+
+	serial_omap_enable_wakeup(up, true);
+
+	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	schedule_work(&up->qos_work);
+
+	return 0;
+}
+
+static int serial_omap_runtime_resume(struct device *dev)
+{
+	struct uart_omap_port *up = dev_get_drvdata(dev);
+
+	int loss_cnt = serial_omap_get_context_loss_count(up);
+
+	serial_omap_enable_wakeup(up, false);
+
+	if (loss_cnt < 0) {
+		dev_dbg(dev, "serial_omap_get_context_loss_count failed : %d\n",
+			loss_cnt);
+		serial_omap_restore_context(up);
+	} else if (up->context_loss_cnt != loss_cnt) {
+		serial_omap_restore_context(up);
+	}
+	up->latency = up->calc_latency;
+	schedule_work(&up->qos_work);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops serial_omap_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)
+	SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,
+				serial_omap_runtime_resume, NULL)
+	.prepare        = serial_omap_prepare,
+	.complete       = serial_omap_complete,
+};
+
+#if defined(CONFIG_OF)
+static const struct of_device_id omap_serial_of_match[] = {
+	{ .compatible = "ti,omap2-uart" },
+	{ .compatible = "ti,omap3-uart" },
+	{ .compatible = "ti,omap4-uart" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, omap_serial_of_match);
+#endif
+
+static struct platform_driver serial_omap_driver = {
+	.probe          = serial_omap_probe,
+	.remove         = serial_omap_remove,
+	.driver		= {
+		.name	= OMAP_SERIAL_DRIVER_NAME,
+		.pm	= &serial_omap_dev_pm_ops,
+		.of_match_table = of_match_ptr(omap_serial_of_match),
+	},
+};
+
+static int __init serial_omap_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&serial_omap_reg);
+	if (ret != 0)
+		return ret;
+	ret = platform_driver_register(&serial_omap_driver);
+	if (ret != 0)
+		uart_unregister_driver(&serial_omap_reg);
+	return ret;
+}
+
+static void __exit serial_omap_exit(void)
+{
+	platform_driver_unregister(&serial_omap_driver);
+	uart_unregister_driver(&serial_omap_reg);
+}
+
+module_init(serial_omap_init);
+module_exit(serial_omap_exit);
+
+MODULE_DESCRIPTION("OMAP High Speed UART driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Texas Instruments Inc");
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
new file mode 100644
index 000000000..e99970a94
--- /dev/null
+++ b/drivers/tty/serial/owl-uart.c
@@ -0,0 +1,772 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Actions Semi Owl family serial console
+ *
+ * Copyright 2013 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2016-2017 Andreas Färber
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define OWL_UART_PORT_NUM 7
+#define OWL_UART_DEV_NAME "ttyOWL"
+
+#define OWL_UART_CTL	0x000
+#define OWL_UART_RXDAT	0x004
+#define OWL_UART_TXDAT	0x008
+#define OWL_UART_STAT	0x00c
+
+#define OWL_UART_CTL_DWLS_MASK		GENMASK(1, 0)
+#define OWL_UART_CTL_DWLS_5BITS		(0x0 << 0)
+#define OWL_UART_CTL_DWLS_6BITS		(0x1 << 0)
+#define OWL_UART_CTL_DWLS_7BITS		(0x2 << 0)
+#define OWL_UART_CTL_DWLS_8BITS		(0x3 << 0)
+#define OWL_UART_CTL_STPS_2BITS		BIT(2)
+#define OWL_UART_CTL_PRS_MASK		GENMASK(6, 4)
+#define OWL_UART_CTL_PRS_NONE		(0x0 << 4)
+#define OWL_UART_CTL_PRS_ODD		(0x4 << 4)
+#define OWL_UART_CTL_PRS_MARK		(0x5 << 4)
+#define OWL_UART_CTL_PRS_EVEN		(0x6 << 4)
+#define OWL_UART_CTL_PRS_SPACE		(0x7 << 4)
+#define OWL_UART_CTL_AFE		BIT(12)
+#define OWL_UART_CTL_TRFS_TX		BIT(14)
+#define OWL_UART_CTL_EN			BIT(15)
+#define OWL_UART_CTL_RXDE		BIT(16)
+#define OWL_UART_CTL_TXDE		BIT(17)
+#define OWL_UART_CTL_RXIE		BIT(18)
+#define OWL_UART_CTL_TXIE		BIT(19)
+#define OWL_UART_CTL_LBEN		BIT(20)
+
+#define OWL_UART_STAT_RIP		BIT(0)
+#define OWL_UART_STAT_TIP		BIT(1)
+#define OWL_UART_STAT_RXER		BIT(2)
+#define OWL_UART_STAT_TFER		BIT(3)
+#define OWL_UART_STAT_RXST		BIT(4)
+#define OWL_UART_STAT_RFEM		BIT(5)
+#define OWL_UART_STAT_TFFU		BIT(6)
+#define OWL_UART_STAT_CTSS		BIT(7)
+#define OWL_UART_STAT_RTSS		BIT(8)
+#define OWL_UART_STAT_TFES		BIT(10)
+#define OWL_UART_STAT_TRFL_MASK		GENMASK(16, 11)
+#define OWL_UART_STAT_UTBB		BIT(17)
+
+#define OWL_UART_POLL_USEC		5
+#define OWL_UART_TIMEOUT_USEC		10000
+
+static struct uart_driver owl_uart_driver;
+
+struct owl_uart_info {
+	unsigned int tx_fifosize;
+};
+
+struct owl_uart_port {
+	struct uart_port port;
+	struct clk *clk;
+};
+
+#define to_owl_uart_port(prt) container_of(prt, struct owl_uart_port, prt)
+
+static struct owl_uart_port *owl_uart_ports[OWL_UART_PORT_NUM];
+
+static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned int off)
+{
+	writel(val, port->membase + off);
+}
+
+static inline u32 owl_uart_read(struct uart_port *port, unsigned int off)
+{
+	return readl(port->membase + off);
+}
+
+static void owl_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 ctl;
+
+	ctl = owl_uart_read(port, OWL_UART_CTL);
+
+	if (mctrl & TIOCM_LOOP)
+		ctl |= OWL_UART_CTL_LBEN;
+	else
+		ctl &= ~OWL_UART_CTL_LBEN;
+
+	owl_uart_write(port, ctl, OWL_UART_CTL);
+}
+
+static unsigned int owl_uart_get_mctrl(struct uart_port *port)
+{
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR;
+	u32 stat, ctl;
+
+	ctl = owl_uart_read(port, OWL_UART_CTL);
+	stat = owl_uart_read(port, OWL_UART_STAT);
+	if (stat & OWL_UART_STAT_RTSS)
+		mctrl |= TIOCM_RTS;
+	if ((stat & OWL_UART_STAT_CTSS) || !(ctl & OWL_UART_CTL_AFE))
+		mctrl |= TIOCM_CTS;
+	return mctrl;
+}
+
+static unsigned int owl_uart_tx_empty(struct uart_port *port)
+{
+	unsigned long flags;
+	u32 val;
+	unsigned int ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = owl_uart_read(port, OWL_UART_STAT);
+	ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return ret;
+}
+
+static void owl_uart_stop_rx(struct uart_port *port)
+{
+	u32 val;
+
+	val = owl_uart_read(port, OWL_UART_CTL);
+	val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_RXDE);
+	owl_uart_write(port, val, OWL_UART_CTL);
+
+	val = owl_uart_read(port, OWL_UART_STAT);
+	val |= OWL_UART_STAT_RIP;
+	owl_uart_write(port, val, OWL_UART_STAT);
+}
+
+static void owl_uart_stop_tx(struct uart_port *port)
+{
+	u32 val;
+
+	val = owl_uart_read(port, OWL_UART_CTL);
+	val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_TXDE);
+	owl_uart_write(port, val, OWL_UART_CTL);
+
+	val = owl_uart_read(port, OWL_UART_STAT);
+	val |= OWL_UART_STAT_TIP;
+	owl_uart_write(port, val, OWL_UART_STAT);
+}
+
+static void owl_uart_start_tx(struct uart_port *port)
+{
+	u32 val;
+
+	if (uart_tx_stopped(port)) {
+		owl_uart_stop_tx(port);
+		return;
+	}
+
+	val = owl_uart_read(port, OWL_UART_STAT);
+	val |= OWL_UART_STAT_TIP;
+	owl_uart_write(port, val, OWL_UART_STAT);
+
+	val = owl_uart_read(port, OWL_UART_CTL);
+	val |= OWL_UART_CTL_TXIE;
+	owl_uart_write(port, val, OWL_UART_CTL);
+}
+
+static void owl_uart_send_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU),
+		owl_uart_write(port, ch, OWL_UART_TXDAT));
+}
+
+static void owl_uart_receive_chars(struct uart_port *port)
+{
+	u32 stat, val;
+
+	val = owl_uart_read(port, OWL_UART_CTL);
+	val &= ~OWL_UART_CTL_TRFS_TX;
+	owl_uart_write(port, val, OWL_UART_CTL);
+
+	stat = owl_uart_read(port, OWL_UART_STAT);
+	while (!(stat & OWL_UART_STAT_RFEM)) {
+		char flag = TTY_NORMAL;
+
+		if (stat & OWL_UART_STAT_RXER)
+			port->icount.overrun++;
+
+		if (stat & OWL_UART_STAT_RXST) {
+			/* We are not able to distinguish the error type. */
+			port->icount.brk++;
+			port->icount.frame++;
+
+			stat &= port->read_status_mask;
+			if (stat & OWL_UART_STAT_RXST)
+				flag = TTY_PARITY;
+		} else
+			port->icount.rx++;
+
+		val = owl_uart_read(port, OWL_UART_RXDAT);
+		val &= 0xff;
+
+		if ((stat & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(&port->state->port, val, flag);
+
+		stat = owl_uart_read(port, OWL_UART_STAT);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static irqreturn_t owl_uart_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned long flags;
+	u32 stat;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	stat = owl_uart_read(port, OWL_UART_STAT);
+
+	if (stat & OWL_UART_STAT_RIP)
+		owl_uart_receive_chars(port);
+
+	if (stat & OWL_UART_STAT_TIP)
+		owl_uart_send_chars(port);
+
+	stat = owl_uart_read(port, OWL_UART_STAT);
+	stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP;
+	owl_uart_write(port, stat, OWL_UART_STAT);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static void owl_uart_shutdown(struct uart_port *port)
+{
+	u32 val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = owl_uart_read(port, OWL_UART_CTL);
+	val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE
+		| OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN);
+	owl_uart_write(port, val, OWL_UART_CTL);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+static int owl_uart_startup(struct uart_port *port)
+{
+	u32 val;
+	unsigned long flags;
+	int ret;
+
+	ret = request_irq(port->irq, owl_uart_irq, IRQF_TRIGGER_HIGH,
+			"owl-uart", port);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = owl_uart_read(port, OWL_UART_STAT);
+	val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP
+		| OWL_UART_STAT_RXER | OWL_UART_STAT_TFER | OWL_UART_STAT_RXST;
+	owl_uart_write(port, val, OWL_UART_STAT);
+
+	val = owl_uart_read(port, OWL_UART_CTL);
+	val |= OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE;
+	val |= OWL_UART_CTL_EN;
+	owl_uart_write(port, val, OWL_UART_CTL);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void owl_uart_change_baudrate(struct owl_uart_port *owl_port,
+				     unsigned long baud)
+{
+	clk_set_rate(owl_port->clk, baud * 8);
+}
+
+static void owl_uart_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	struct owl_uart_port *owl_port = to_owl_uart_port(port);
+	unsigned int baud;
+	u32 ctl;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	ctl = owl_uart_read(port, OWL_UART_CTL);
+
+	ctl &= ~OWL_UART_CTL_DWLS_MASK;
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		ctl |= OWL_UART_CTL_DWLS_5BITS;
+		break;
+	case CS6:
+		ctl |= OWL_UART_CTL_DWLS_6BITS;
+		break;
+	case CS7:
+		ctl |= OWL_UART_CTL_DWLS_7BITS;
+		break;
+	case CS8:
+	default:
+		ctl |= OWL_UART_CTL_DWLS_8BITS;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		ctl |= OWL_UART_CTL_STPS_2BITS;
+	else
+		ctl &= ~OWL_UART_CTL_STPS_2BITS;
+
+	ctl &= ~OWL_UART_CTL_PRS_MASK;
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & CMSPAR) {
+			if (termios->c_cflag & PARODD)
+				ctl |= OWL_UART_CTL_PRS_MARK;
+			else
+				ctl |= OWL_UART_CTL_PRS_SPACE;
+		} else if (termios->c_cflag & PARODD)
+			ctl |= OWL_UART_CTL_PRS_ODD;
+		else
+			ctl |= OWL_UART_CTL_PRS_EVEN;
+	} else
+		ctl |= OWL_UART_CTL_PRS_NONE;
+
+	if (termios->c_cflag & CRTSCTS)
+		ctl |= OWL_UART_CTL_AFE;
+	else
+		ctl &= ~OWL_UART_CTL_AFE;
+
+	owl_uart_write(port, ctl, OWL_UART_CTL);
+
+	baud = uart_get_baud_rate(port, termios, old, 9600, 3200000);
+	owl_uart_change_baudrate(owl_port, baud);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	port->read_status_mask |= OWL_UART_STAT_RXER;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= OWL_UART_STAT_RXST;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void owl_uart_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return;
+
+	if (port->flags & UPF_IOREMAP) {
+		devm_release_mem_region(port->dev, port->mapbase,
+			resource_size(res));
+		devm_iounmap(port->dev, port->membase);
+		port->membase = NULL;
+	}
+}
+
+static int owl_uart_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENXIO;
+
+	if (!devm_request_mem_region(port->dev, port->mapbase,
+			resource_size(res), dev_name(port->dev)))
+		return -EBUSY;
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = devm_ioremap(port->dev, port->mapbase,
+				resource_size(res));
+		if (!port->membase)
+			return -EBUSY;
+	}
+
+	return 0;
+}
+
+static const char *owl_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_OWL) ? "owl-uart" : NULL;
+}
+
+static int owl_uart_verify_port(struct uart_port *port,
+				struct serial_struct *ser)
+{
+	if (port->type != PORT_OWL)
+		return -EINVAL;
+
+	if (port->irq != ser->irq)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void owl_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_OWL;
+		owl_uart_request_port(port);
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static int owl_uart_poll_get_char(struct uart_port *port)
+{
+	if (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_RFEM)
+		return NO_POLL_CHAR;
+
+	return owl_uart_read(port, OWL_UART_RXDAT);
+}
+
+static void owl_uart_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+	u32 reg;
+	int ret;
+
+	/* Wait while FIFO is full or timeout */
+	ret = readl_poll_timeout_atomic(port->membase + OWL_UART_STAT, reg,
+					!(reg & OWL_UART_STAT_TFFU),
+					OWL_UART_POLL_USEC,
+					OWL_UART_TIMEOUT_USEC);
+	if (ret == -ETIMEDOUT) {
+		dev_err(port->dev, "Timeout waiting while UART TX FULL\n");
+		return;
+	}
+
+	owl_uart_write(port, ch, OWL_UART_TXDAT);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops owl_uart_ops = {
+	.set_mctrl = owl_uart_set_mctrl,
+	.get_mctrl = owl_uart_get_mctrl,
+	.tx_empty = owl_uart_tx_empty,
+	.start_tx = owl_uart_start_tx,
+	.stop_rx = owl_uart_stop_rx,
+	.stop_tx = owl_uart_stop_tx,
+	.startup = owl_uart_startup,
+	.shutdown = owl_uart_shutdown,
+	.set_termios = owl_uart_set_termios,
+	.type = owl_uart_type,
+	.config_port = owl_uart_config_port,
+	.request_port = owl_uart_request_port,
+	.release_port = owl_uart_release_port,
+	.verify_port = owl_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = owl_uart_poll_get_char,
+	.poll_put_char = owl_uart_poll_put_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_OWL_CONSOLE
+
+static void owl_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	if (!port->membase)
+		return;
+
+	while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)
+		cpu_relax();
+
+	owl_uart_write(port, ch, OWL_UART_TXDAT);
+}
+
+static void owl_uart_port_write(struct uart_port *port, const char *s,
+				u_int count)
+{
+	u32 old_ctl, val;
+	unsigned long flags;
+	int locked;
+
+	local_irq_save(flags);
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&port->lock);
+	else {
+		spin_lock(&port->lock);
+		locked = 1;
+	}
+
+	old_ctl = owl_uart_read(port, OWL_UART_CTL);
+	val = old_ctl | OWL_UART_CTL_TRFS_TX;
+	/* disable IRQ */
+	val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE);
+	owl_uart_write(port, val, OWL_UART_CTL);
+
+	uart_console_write(port, s, count, owl_console_putchar);
+
+	/* wait until all contents have been sent out */
+	while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TRFL_MASK)
+		cpu_relax();
+
+	/* clear IRQ pending */
+	val = owl_uart_read(port, OWL_UART_STAT);
+	val |= OWL_UART_STAT_TIP | OWL_UART_STAT_RIP;
+	owl_uart_write(port, val, OWL_UART_STAT);
+
+	owl_uart_write(port, old_ctl, OWL_UART_CTL);
+
+	if (locked)
+		spin_unlock(&port->lock);
+
+	local_irq_restore(flags);
+}
+
+static void owl_uart_console_write(struct console *co, const char *s,
+				   u_int count)
+{
+	struct owl_uart_port *owl_port;
+
+	owl_port = owl_uart_ports[co->index];
+	if (!owl_port)
+		return;
+
+	owl_uart_port_write(&owl_port->port, s, count);
+}
+
+static int owl_uart_console_setup(struct console *co, char *options)
+{
+	struct owl_uart_port *owl_port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= OWL_UART_PORT_NUM)
+		return -EINVAL;
+
+	owl_port = owl_uart_ports[co->index];
+	if (!owl_port || !owl_port->port.membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&owl_port->port, co, baud, parity, bits, flow);
+}
+
+static struct console owl_uart_console = {
+	.name = OWL_UART_DEV_NAME,
+	.write = owl_uart_console_write,
+	.device = uart_console_device,
+	.setup = owl_uart_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &owl_uart_driver,
+};
+
+static int __init owl_uart_console_init(void)
+{
+	register_console(&owl_uart_console);
+
+	return 0;
+}
+console_initcall(owl_uart_console_init);
+
+static void owl_uart_early_console_write(struct console *co,
+					 const char *s,
+					 u_int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	owl_uart_port_write(&dev->port, s, count);
+}
+
+static int __init
+owl_uart_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = owl_uart_early_console_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(owl, "actions,owl-uart",
+		    owl_uart_early_console_setup);
+
+#define OWL_UART_CONSOLE (&owl_uart_console)
+#else
+#define OWL_UART_CONSOLE NULL
+#endif
+
+static struct uart_driver owl_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "owl-uart",
+	.dev_name = OWL_UART_DEV_NAME,
+	.nr = OWL_UART_PORT_NUM,
+	.cons = OWL_UART_CONSOLE,
+};
+
+static const struct owl_uart_info owl_s500_info = {
+	.tx_fifosize = 16,
+};
+
+static const struct owl_uart_info owl_s900_info = {
+	.tx_fifosize = 32,
+};
+
+static const struct of_device_id owl_uart_dt_matches[] = {
+	{ .compatible = "actions,s500-uart", .data = &owl_s500_info },
+	{ .compatible = "actions,s900-uart", .data = &owl_s900_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, owl_uart_dt_matches);
+
+static int owl_uart_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	const struct owl_uart_info *info = NULL;
+	struct resource *res_mem;
+	struct owl_uart_port *owl_port;
+	int ret, irq;
+
+	if (pdev->dev.of_node) {
+		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+		match = of_match_node(owl_uart_dt_matches, pdev->dev.of_node);
+		if (match)
+			info = match->data;
+	}
+
+	if (pdev->id < 0 || pdev->id >= OWL_UART_PORT_NUM) {
+		dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
+		return -EINVAL;
+	}
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem) {
+		dev_err(&pdev->dev, "could not get mem\n");
+		return -ENODEV;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	if (owl_uart_ports[pdev->id]) {
+		dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
+		return -EBUSY;
+	}
+
+	owl_port = devm_kzalloc(&pdev->dev, sizeof(*owl_port), GFP_KERNEL);
+	if (!owl_port)
+		return -ENOMEM;
+
+	owl_port->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(owl_port->clk)) {
+		dev_err(&pdev->dev, "could not get clk\n");
+		return PTR_ERR(owl_port->clk);
+	}
+
+	ret = clk_prepare_enable(owl_port->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "could not enable clk\n");
+		return ret;
+	}
+
+	owl_port->port.dev = &pdev->dev;
+	owl_port->port.line = pdev->id;
+	owl_port->port.type = PORT_OWL;
+	owl_port->port.iotype = UPIO_MEM;
+	owl_port->port.mapbase = res_mem->start;
+	owl_port->port.irq = irq;
+	owl_port->port.uartclk = clk_get_rate(owl_port->clk);
+	if (owl_port->port.uartclk == 0) {
+		dev_err(&pdev->dev, "clock rate is zero\n");
+		clk_disable_unprepare(owl_port->clk);
+		return -EINVAL;
+	}
+	owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY;
+	owl_port->port.x_char = 0;
+	owl_port->port.fifosize = (info) ? info->tx_fifosize : 16;
+	owl_port->port.ops = &owl_uart_ops;
+
+	owl_uart_ports[pdev->id] = owl_port;
+	platform_set_drvdata(pdev, owl_port);
+
+	ret = uart_add_one_port(&owl_uart_driver, &owl_port->port);
+	if (ret)
+		owl_uart_ports[pdev->id] = NULL;
+
+	return ret;
+}
+
+static int owl_uart_remove(struct platform_device *pdev)
+{
+	struct owl_uart_port *owl_port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&owl_uart_driver, &owl_port->port);
+	owl_uart_ports[pdev->id] = NULL;
+	clk_disable_unprepare(owl_port->clk);
+
+	return 0;
+}
+
+static struct platform_driver owl_uart_platform_driver = {
+	.probe = owl_uart_probe,
+	.remove = owl_uart_remove,
+	.driver = {
+		.name = "owl-uart",
+		.of_match_table = owl_uart_dt_matches,
+	},
+};
+
+static int __init owl_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&owl_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&owl_uart_platform_driver);
+	if (ret)
+		uart_unregister_driver(&owl_uart_driver);
+
+	return ret;
+}
+
+static void __exit owl_uart_exit(void)
+{
+	platform_driver_unregister(&owl_uart_platform_driver);
+	uart_unregister_driver(&owl_uart_driver);
+}
+
+module_init(owl_uart_init);
+module_exit(owl_uart_exit);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
new file mode 100644
index 000000000..cc83b772b
--- /dev/null
+++ b/drivers/tty/serial/pch_uart.c
@@ -0,0 +1,1914 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/dmi.h>
+#include <linux/nmi.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+
+#include <linux/debugfs.h>
+#include <linux/dmaengine.h>
+#include <linux/pch_dma.h>
+
+enum {
+	PCH_UART_HANDLED_RX_INT_SHIFT,
+	PCH_UART_HANDLED_TX_INT_SHIFT,
+	PCH_UART_HANDLED_RX_ERR_INT_SHIFT,
+	PCH_UART_HANDLED_RX_TRG_INT_SHIFT,
+	PCH_UART_HANDLED_MS_INT_SHIFT,
+	PCH_UART_HANDLED_LS_INT_SHIFT,
+};
+
+#define PCH_UART_DRIVER_DEVICE "ttyPCH"
+
+/* Set the max number of UART port
+ * Intel EG20T PCH: 4 port
+ * LAPIS Semiconductor ML7213 IOH: 3 port
+ * LAPIS Semiconductor ML7223 IOH: 2 port
+*/
+#define PCH_UART_NR	4
+
+#define PCH_UART_HANDLED_RX_INT	(1<<((PCH_UART_HANDLED_RX_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_TX_INT	(1<<((PCH_UART_HANDLED_TX_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_RX_ERR_INT	(1<<((\
+					PCH_UART_HANDLED_RX_ERR_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_RX_TRG_INT	(1<<((\
+					PCH_UART_HANDLED_RX_TRG_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_MS_INT	(1<<((PCH_UART_HANDLED_MS_INT_SHIFT)<<1))
+
+#define PCH_UART_HANDLED_LS_INT	(1<<((PCH_UART_HANDLED_LS_INT_SHIFT)<<1))
+
+#define PCH_UART_RBR		0x00
+#define PCH_UART_THR		0x00
+
+#define PCH_UART_IER_MASK	(PCH_UART_IER_ERBFI|PCH_UART_IER_ETBEI|\
+				PCH_UART_IER_ELSI|PCH_UART_IER_EDSSI)
+#define PCH_UART_IER_ERBFI	0x00000001
+#define PCH_UART_IER_ETBEI	0x00000002
+#define PCH_UART_IER_ELSI	0x00000004
+#define PCH_UART_IER_EDSSI	0x00000008
+
+#define PCH_UART_IIR_IP			0x00000001
+#define PCH_UART_IIR_IID		0x00000006
+#define PCH_UART_IIR_MSI		0x00000000
+#define PCH_UART_IIR_TRI		0x00000002
+#define PCH_UART_IIR_RRI		0x00000004
+#define PCH_UART_IIR_REI		0x00000006
+#define PCH_UART_IIR_TOI		0x00000008
+#define PCH_UART_IIR_FIFO256		0x00000020
+#define PCH_UART_IIR_FIFO64		PCH_UART_IIR_FIFO256
+#define PCH_UART_IIR_FE			0x000000C0
+
+#define PCH_UART_FCR_FIFOE		0x00000001
+#define PCH_UART_FCR_RFR		0x00000002
+#define PCH_UART_FCR_TFR		0x00000004
+#define PCH_UART_FCR_DMS		0x00000008
+#define PCH_UART_FCR_FIFO256		0x00000020
+#define PCH_UART_FCR_RFTL		0x000000C0
+
+#define PCH_UART_FCR_RFTL1		0x00000000
+#define PCH_UART_FCR_RFTL64		0x00000040
+#define PCH_UART_FCR_RFTL128		0x00000080
+#define PCH_UART_FCR_RFTL224		0x000000C0
+#define PCH_UART_FCR_RFTL16		PCH_UART_FCR_RFTL64
+#define PCH_UART_FCR_RFTL32		PCH_UART_FCR_RFTL128
+#define PCH_UART_FCR_RFTL56		PCH_UART_FCR_RFTL224
+#define PCH_UART_FCR_RFTL4		PCH_UART_FCR_RFTL64
+#define PCH_UART_FCR_RFTL8		PCH_UART_FCR_RFTL128
+#define PCH_UART_FCR_RFTL14		PCH_UART_FCR_RFTL224
+#define PCH_UART_FCR_RFTL_SHIFT		6
+
+#define PCH_UART_LCR_WLS	0x00000003
+#define PCH_UART_LCR_STB	0x00000004
+#define PCH_UART_LCR_PEN	0x00000008
+#define PCH_UART_LCR_EPS	0x00000010
+#define PCH_UART_LCR_SP		0x00000020
+#define PCH_UART_LCR_SB		0x00000040
+#define PCH_UART_LCR_DLAB	0x00000080
+#define PCH_UART_LCR_NP		0x00000000
+#define PCH_UART_LCR_OP		PCH_UART_LCR_PEN
+#define PCH_UART_LCR_EP		(PCH_UART_LCR_PEN | PCH_UART_LCR_EPS)
+#define PCH_UART_LCR_1P		(PCH_UART_LCR_PEN | PCH_UART_LCR_SP)
+#define PCH_UART_LCR_0P		(PCH_UART_LCR_PEN | PCH_UART_LCR_EPS |\
+				PCH_UART_LCR_SP)
+
+#define PCH_UART_LCR_5BIT	0x00000000
+#define PCH_UART_LCR_6BIT	0x00000001
+#define PCH_UART_LCR_7BIT	0x00000002
+#define PCH_UART_LCR_8BIT	0x00000003
+
+#define PCH_UART_MCR_DTR	0x00000001
+#define PCH_UART_MCR_RTS	0x00000002
+#define PCH_UART_MCR_OUT	0x0000000C
+#define PCH_UART_MCR_LOOP	0x00000010
+#define PCH_UART_MCR_AFE	0x00000020
+
+#define PCH_UART_LSR_DR		0x00000001
+#define PCH_UART_LSR_ERR	(1<<7)
+
+#define PCH_UART_MSR_DCTS	0x00000001
+#define PCH_UART_MSR_DDSR	0x00000002
+#define PCH_UART_MSR_TERI	0x00000004
+#define PCH_UART_MSR_DDCD	0x00000008
+#define PCH_UART_MSR_CTS	0x00000010
+#define PCH_UART_MSR_DSR	0x00000020
+#define PCH_UART_MSR_RI		0x00000040
+#define PCH_UART_MSR_DCD	0x00000080
+#define PCH_UART_MSR_DELTA	(PCH_UART_MSR_DCTS | PCH_UART_MSR_DDSR |\
+				PCH_UART_MSR_TERI | PCH_UART_MSR_DDCD)
+
+#define PCH_UART_DLL		0x00
+#define PCH_UART_DLM		0x01
+
+#define PCH_UART_BRCSR		0x0E
+
+#define PCH_UART_IID_RLS	(PCH_UART_IIR_REI)
+#define PCH_UART_IID_RDR	(PCH_UART_IIR_RRI)
+#define PCH_UART_IID_RDR_TO	(PCH_UART_IIR_RRI | PCH_UART_IIR_TOI)
+#define PCH_UART_IID_THRE	(PCH_UART_IIR_TRI)
+#define PCH_UART_IID_MS		(PCH_UART_IIR_MSI)
+
+#define PCH_UART_HAL_PARITY_NONE	(PCH_UART_LCR_NP)
+#define PCH_UART_HAL_PARITY_ODD		(PCH_UART_LCR_OP)
+#define PCH_UART_HAL_PARITY_EVEN	(PCH_UART_LCR_EP)
+#define PCH_UART_HAL_PARITY_FIX1	(PCH_UART_LCR_1P)
+#define PCH_UART_HAL_PARITY_FIX0	(PCH_UART_LCR_0P)
+#define PCH_UART_HAL_5BIT		(PCH_UART_LCR_5BIT)
+#define PCH_UART_HAL_6BIT		(PCH_UART_LCR_6BIT)
+#define PCH_UART_HAL_7BIT		(PCH_UART_LCR_7BIT)
+#define PCH_UART_HAL_8BIT		(PCH_UART_LCR_8BIT)
+#define PCH_UART_HAL_STB1		0
+#define PCH_UART_HAL_STB2		(PCH_UART_LCR_STB)
+
+#define PCH_UART_HAL_CLR_TX_FIFO	(PCH_UART_FCR_TFR)
+#define PCH_UART_HAL_CLR_RX_FIFO	(PCH_UART_FCR_RFR)
+#define PCH_UART_HAL_CLR_ALL_FIFO	(PCH_UART_HAL_CLR_TX_FIFO | \
+					PCH_UART_HAL_CLR_RX_FIFO)
+
+#define PCH_UART_HAL_DMA_MODE0		0
+#define PCH_UART_HAL_FIFO_DIS		0
+#define PCH_UART_HAL_FIFO16		(PCH_UART_FCR_FIFOE)
+#define PCH_UART_HAL_FIFO256		(PCH_UART_FCR_FIFOE | \
+					PCH_UART_FCR_FIFO256)
+#define PCH_UART_HAL_FIFO64		(PCH_UART_HAL_FIFO256)
+#define PCH_UART_HAL_TRIGGER1		(PCH_UART_FCR_RFTL1)
+#define PCH_UART_HAL_TRIGGER64		(PCH_UART_FCR_RFTL64)
+#define PCH_UART_HAL_TRIGGER128		(PCH_UART_FCR_RFTL128)
+#define PCH_UART_HAL_TRIGGER224		(PCH_UART_FCR_RFTL224)
+#define PCH_UART_HAL_TRIGGER16		(PCH_UART_FCR_RFTL16)
+#define PCH_UART_HAL_TRIGGER32		(PCH_UART_FCR_RFTL32)
+#define PCH_UART_HAL_TRIGGER56		(PCH_UART_FCR_RFTL56)
+#define PCH_UART_HAL_TRIGGER4		(PCH_UART_FCR_RFTL4)
+#define PCH_UART_HAL_TRIGGER8		(PCH_UART_FCR_RFTL8)
+#define PCH_UART_HAL_TRIGGER14		(PCH_UART_FCR_RFTL14)
+#define PCH_UART_HAL_TRIGGER_L		(PCH_UART_FCR_RFTL64)
+#define PCH_UART_HAL_TRIGGER_M		(PCH_UART_FCR_RFTL128)
+#define PCH_UART_HAL_TRIGGER_H		(PCH_UART_FCR_RFTL224)
+
+#define PCH_UART_HAL_RX_INT		(PCH_UART_IER_ERBFI)
+#define PCH_UART_HAL_TX_INT		(PCH_UART_IER_ETBEI)
+#define PCH_UART_HAL_RX_ERR_INT		(PCH_UART_IER_ELSI)
+#define PCH_UART_HAL_MS_INT		(PCH_UART_IER_EDSSI)
+#define PCH_UART_HAL_ALL_INT		(PCH_UART_IER_MASK)
+
+#define PCH_UART_HAL_DTR		(PCH_UART_MCR_DTR)
+#define PCH_UART_HAL_RTS		(PCH_UART_MCR_RTS)
+#define PCH_UART_HAL_OUT		(PCH_UART_MCR_OUT)
+#define PCH_UART_HAL_LOOP		(PCH_UART_MCR_LOOP)
+#define PCH_UART_HAL_AFE		(PCH_UART_MCR_AFE)
+
+#define DEFAULT_UARTCLK   1843200 /*   1.8432 MHz */
+#define CMITC_UARTCLK   192000000 /* 192.0000 MHz */
+#define FRI2_64_UARTCLK  64000000 /*  64.0000 MHz */
+#define FRI2_48_UARTCLK  48000000 /*  48.0000 MHz */
+#define NTC1_UARTCLK     64000000 /*  64.0000 MHz */
+#define MINNOW_UARTCLK   50000000 /*  50.0000 MHz */
+
+struct pch_uart_buffer {
+	unsigned char *buf;
+	int size;
+};
+
+struct eg20t_port {
+	struct uart_port port;
+	int port_type;
+	void __iomem *membase;
+	resource_size_t mapbase;
+	unsigned int iobase;
+	struct pci_dev *pdev;
+	int fifo_size;
+	unsigned int uartclk;
+	int start_tx;
+	int start_rx;
+	int tx_empty;
+	int trigger;
+	int trigger_level;
+	struct pch_uart_buffer rxbuf;
+	unsigned int dmsr;
+	unsigned int fcr;
+	unsigned int mcr;
+	unsigned int use_dma;
+	struct dma_async_tx_descriptor	*desc_tx;
+	struct dma_async_tx_descriptor	*desc_rx;
+	struct pch_dma_slave		param_tx;
+	struct pch_dma_slave		param_rx;
+	struct dma_chan			*chan_tx;
+	struct dma_chan			*chan_rx;
+	struct scatterlist		*sg_tx_p;
+	int				nent;
+	int				orig_nent;
+	struct scatterlist		sg_rx;
+	int				tx_dma_use;
+	void				*rx_buf_virt;
+	dma_addr_t			rx_buf_dma;
+
+#define IRQ_NAME_SIZE 17
+	char				irq_name[IRQ_NAME_SIZE];
+
+	/* protect the eg20t_port private structure and io access to membase */
+	spinlock_t lock;
+};
+
+/**
+ * struct pch_uart_driver_data - private data structure for UART-DMA
+ * @port_type:			The type of UART port
+ * @line_no:			UART port line number (0, 1, 2...)
+ */
+struct pch_uart_driver_data {
+	int port_type;
+	int line_no;
+};
+
+enum pch_uart_num_t {
+	pch_et20t_uart0 = 0,
+	pch_et20t_uart1,
+	pch_et20t_uart2,
+	pch_et20t_uart3,
+	pch_ml7213_uart0,
+	pch_ml7213_uart1,
+	pch_ml7213_uart2,
+	pch_ml7223_uart0,
+	pch_ml7223_uart1,
+	pch_ml7831_uart0,
+	pch_ml7831_uart1,
+};
+
+static struct pch_uart_driver_data drv_dat[] = {
+	[pch_et20t_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_et20t_uart1] = {PORT_PCH_2LINE, 1},
+	[pch_et20t_uart2] = {PORT_PCH_2LINE, 2},
+	[pch_et20t_uart3] = {PORT_PCH_2LINE, 3},
+	[pch_ml7213_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_ml7213_uart1] = {PORT_PCH_2LINE, 1},
+	[pch_ml7213_uart2] = {PORT_PCH_2LINE, 2},
+	[pch_ml7223_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_ml7223_uart1] = {PORT_PCH_2LINE, 1},
+	[pch_ml7831_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_ml7831_uart1] = {PORT_PCH_2LINE, 1},
+};
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+static struct eg20t_port *pch_uart_ports[PCH_UART_NR];
+#endif
+static unsigned int default_baud = 9600;
+static unsigned int user_uartclk = 0;
+static const int trigger_level_256[4] = { 1, 64, 128, 224 };
+static const int trigger_level_64[4] = { 1, 16, 32, 56 };
+static const int trigger_level_16[4] = { 1, 4, 8, 14 };
+static const int trigger_level_1[4] = { 1, 1, 1, 1 };
+
+#define PCH_REGS_BUFSIZE	1024
+
+
+static ssize_t port_show_regs(struct file *file, char __user *user_buf,
+				size_t count, loff_t *ppos)
+{
+	struct eg20t_port *priv = file->private_data;
+	char *buf;
+	u32 len = 0;
+	ssize_t ret;
+	unsigned char lcr;
+
+	buf = kzalloc(PCH_REGS_BUFSIZE, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"PCH EG20T port[%d] regs:\n", priv->port.line);
+
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"=================================\n");
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"IER: \t0x%02x\n", ioread8(priv->membase + UART_IER));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"IIR: \t0x%02x\n", ioread8(priv->membase + UART_IIR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"LCR: \t0x%02x\n", ioread8(priv->membase + UART_LCR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"MCR: \t0x%02x\n", ioread8(priv->membase + UART_MCR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"LSR: \t0x%02x\n", ioread8(priv->membase + UART_LSR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"MSR: \t0x%02x\n", ioread8(priv->membase + UART_MSR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"BRCSR: \t0x%02x\n",
+			ioread8(priv->membase + PCH_UART_BRCSR));
+
+	lcr = ioread8(priv->membase + UART_LCR);
+	iowrite8(PCH_UART_LCR_DLAB, priv->membase + UART_LCR);
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"DLL: \t0x%02x\n", ioread8(priv->membase + UART_DLL));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"DLM: \t0x%02x\n", ioread8(priv->membase + UART_DLM));
+	iowrite8(lcr, priv->membase + UART_LCR);
+
+	if (len > PCH_REGS_BUFSIZE)
+		len = PCH_REGS_BUFSIZE;
+
+	ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations port_regs_ops = {
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.read		= port_show_regs,
+	.llseek		= default_llseek,
+};
+
+static const struct dmi_system_id pch_uart_dmi_table[] = {
+	{
+		.ident = "CM-iTC",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "CM-iTC"),
+		},
+		(void *)CMITC_UARTCLK,
+	},
+	{
+		.ident = "FRI2",
+		{
+			DMI_MATCH(DMI_BIOS_VERSION, "FRI2"),
+		},
+		(void *)FRI2_64_UARTCLK,
+	},
+	{
+		.ident = "Fish River Island II",
+		{
+			DMI_MATCH(DMI_PRODUCT_NAME, "Fish River Island II"),
+		},
+		(void *)FRI2_48_UARTCLK,
+	},
+	{
+		.ident = "COMe-mTT",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "COMe-mTT"),
+		},
+		(void *)NTC1_UARTCLK,
+	},
+	{
+		.ident = "nanoETXexpress-TT",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "nanoETXexpress-TT"),
+		},
+		(void *)NTC1_UARTCLK,
+	},
+	{
+		.ident = "MinnowBoard",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "MinnowBoard"),
+		},
+		(void *)MINNOW_UARTCLK,
+	},
+	{ }
+};
+
+/* Return UART clock, checking for board specific clocks. */
+static unsigned int pch_uart_get_uartclk(void)
+{
+	const struct dmi_system_id *d;
+
+	if (user_uartclk)
+		return user_uartclk;
+
+	d = dmi_first_match(pch_uart_dmi_table);
+	if (d)
+		return (unsigned long)d->driver_data;
+
+	return DEFAULT_UARTCLK;
+}
+
+static void pch_uart_hal_enable_interrupt(struct eg20t_port *priv,
+					  unsigned int flag)
+{
+	u8 ier = ioread8(priv->membase + UART_IER);
+	ier |= flag & PCH_UART_IER_MASK;
+	iowrite8(ier, priv->membase + UART_IER);
+}
+
+static void pch_uart_hal_disable_interrupt(struct eg20t_port *priv,
+					   unsigned int flag)
+{
+	u8 ier = ioread8(priv->membase + UART_IER);
+	ier &= ~(flag & PCH_UART_IER_MASK);
+	iowrite8(ier, priv->membase + UART_IER);
+}
+
+static int pch_uart_hal_set_line(struct eg20t_port *priv, unsigned int baud,
+				 unsigned int parity, unsigned int bits,
+				 unsigned int stb)
+{
+	unsigned int dll, dlm, lcr;
+	int div;
+
+	div = DIV_ROUND_CLOSEST(priv->uartclk / 16, baud);
+	if (div < 0 || USHRT_MAX <= div) {
+		dev_err(priv->port.dev, "Invalid Baud(div=0x%x)\n", div);
+		return -EINVAL;
+	}
+
+	dll = (unsigned int)div & 0x00FFU;
+	dlm = ((unsigned int)div >> 8) & 0x00FFU;
+
+	if (parity & ~(PCH_UART_LCR_PEN | PCH_UART_LCR_EPS | PCH_UART_LCR_SP)) {
+		dev_err(priv->port.dev, "Invalid parity(0x%x)\n", parity);
+		return -EINVAL;
+	}
+
+	if (bits & ~PCH_UART_LCR_WLS) {
+		dev_err(priv->port.dev, "Invalid bits(0x%x)\n", bits);
+		return -EINVAL;
+	}
+
+	if (stb & ~PCH_UART_LCR_STB) {
+		dev_err(priv->port.dev, "Invalid STB(0x%x)\n", stb);
+		return -EINVAL;
+	}
+
+	lcr = parity;
+	lcr |= bits;
+	lcr |= stb;
+
+	dev_dbg(priv->port.dev, "%s:baud = %u, div = %04x, lcr = %02x (%lu)\n",
+		 __func__, baud, div, lcr, jiffies);
+	iowrite8(PCH_UART_LCR_DLAB, priv->membase + UART_LCR);
+	iowrite8(dll, priv->membase + PCH_UART_DLL);
+	iowrite8(dlm, priv->membase + PCH_UART_DLM);
+	iowrite8(lcr, priv->membase + UART_LCR);
+
+	return 0;
+}
+
+static int pch_uart_hal_fifo_reset(struct eg20t_port *priv,
+				    unsigned int flag)
+{
+	if (flag & ~(PCH_UART_FCR_TFR | PCH_UART_FCR_RFR)) {
+		dev_err(priv->port.dev, "%s:Invalid flag(0x%x)\n",
+			__func__, flag);
+		return -EINVAL;
+	}
+
+	iowrite8(PCH_UART_FCR_FIFOE | priv->fcr, priv->membase + UART_FCR);
+	iowrite8(PCH_UART_FCR_FIFOE | priv->fcr | flag,
+		 priv->membase + UART_FCR);
+	iowrite8(priv->fcr, priv->membase + UART_FCR);
+
+	return 0;
+}
+
+static int pch_uart_hal_set_fifo(struct eg20t_port *priv,
+				 unsigned int dmamode,
+				 unsigned int fifo_size, unsigned int trigger)
+{
+	u8 fcr;
+
+	if (dmamode & ~PCH_UART_FCR_DMS) {
+		dev_err(priv->port.dev, "%s:Invalid DMA Mode(0x%x)\n",
+			__func__, dmamode);
+		return -EINVAL;
+	}
+
+	if (fifo_size & ~(PCH_UART_FCR_FIFOE | PCH_UART_FCR_FIFO256)) {
+		dev_err(priv->port.dev, "%s:Invalid FIFO SIZE(0x%x)\n",
+			__func__, fifo_size);
+		return -EINVAL;
+	}
+
+	if (trigger & ~PCH_UART_FCR_RFTL) {
+		dev_err(priv->port.dev, "%s:Invalid TRIGGER(0x%x)\n",
+			__func__, trigger);
+		return -EINVAL;
+	}
+
+	switch (priv->fifo_size) {
+	case 256:
+		priv->trigger_level =
+		    trigger_level_256[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	case 64:
+		priv->trigger_level =
+		    trigger_level_64[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	case 16:
+		priv->trigger_level =
+		    trigger_level_16[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	default:
+		priv->trigger_level =
+		    trigger_level_1[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	}
+	fcr =
+	    dmamode | fifo_size | trigger | PCH_UART_FCR_RFR | PCH_UART_FCR_TFR;
+	iowrite8(PCH_UART_FCR_FIFOE, priv->membase + UART_FCR);
+	iowrite8(PCH_UART_FCR_FIFOE | PCH_UART_FCR_RFR | PCH_UART_FCR_TFR,
+		 priv->membase + UART_FCR);
+	iowrite8(fcr, priv->membase + UART_FCR);
+	priv->fcr = fcr;
+
+	return 0;
+}
+
+static u8 pch_uart_hal_get_modem(struct eg20t_port *priv)
+{
+	unsigned int msr = ioread8(priv->membase + UART_MSR);
+	priv->dmsr = msr & PCH_UART_MSR_DELTA;
+	return (u8)msr;
+}
+
+static int pch_uart_hal_read(struct eg20t_port *priv, unsigned char *buf,
+			     int rx_size)
+{
+	int i;
+	u8 rbr, lsr;
+	struct uart_port *port = &priv->port;
+
+	lsr = ioread8(priv->membase + UART_LSR);
+	for (i = 0, lsr = ioread8(priv->membase + UART_LSR);
+	     i < rx_size && lsr & (UART_LSR_DR | UART_LSR_BI);
+	     lsr = ioread8(priv->membase + UART_LSR)) {
+		rbr = ioread8(priv->membase + PCH_UART_RBR);
+
+		if (lsr & UART_LSR_BI) {
+			port->icount.brk++;
+			if (uart_handle_break(port))
+				continue;
+		}
+		if (uart_handle_sysrq_char(port, rbr))
+			continue;
+
+		buf[i++] = rbr;
+	}
+	return i;
+}
+
+static unsigned char pch_uart_hal_get_iid(struct eg20t_port *priv)
+{
+	return ioread8(priv->membase + UART_IIR) &\
+		      (PCH_UART_IIR_IID | PCH_UART_IIR_TOI | PCH_UART_IIR_IP);
+}
+
+static u8 pch_uart_hal_get_line_status(struct eg20t_port *priv)
+{
+	return ioread8(priv->membase + UART_LSR);
+}
+
+static void pch_uart_hal_set_break(struct eg20t_port *priv, int on)
+{
+	unsigned int lcr;
+
+	lcr = ioread8(priv->membase + UART_LCR);
+	if (on)
+		lcr |= PCH_UART_LCR_SB;
+	else
+		lcr &= ~PCH_UART_LCR_SB;
+
+	iowrite8(lcr, priv->membase + UART_LCR);
+}
+
+static int push_rx(struct eg20t_port *priv, const unsigned char *buf,
+		   int size)
+{
+	struct uart_port *port = &priv->port;
+	struct tty_port *tport = &port->state->port;
+
+	tty_insert_flip_string(tport, buf, size);
+	tty_flip_buffer_push(tport);
+
+	return 0;
+}
+
+static int dma_push_rx(struct eg20t_port *priv, int size)
+{
+	int room;
+	struct uart_port *port = &priv->port;
+	struct tty_port *tport = &port->state->port;
+
+	room = tty_buffer_request_room(tport, size);
+
+	if (room < size)
+		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
+			 size - room);
+	if (!room)
+		return 0;
+
+	tty_insert_flip_string(tport, sg_virt(&priv->sg_rx), size);
+
+	port->icount.rx += room;
+
+	return room;
+}
+
+static void pch_free_dma(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+
+	if (priv->chan_tx) {
+		dma_release_channel(priv->chan_tx);
+		priv->chan_tx = NULL;
+	}
+	if (priv->chan_rx) {
+		dma_release_channel(priv->chan_rx);
+		priv->chan_rx = NULL;
+	}
+
+	if (priv->rx_buf_dma) {
+		dma_free_coherent(port->dev, port->fifosize, priv->rx_buf_virt,
+				  priv->rx_buf_dma);
+		priv->rx_buf_virt = NULL;
+		priv->rx_buf_dma = 0;
+	}
+
+	return;
+}
+
+static bool filter(struct dma_chan *chan, void *slave)
+{
+	struct pch_dma_slave *param = slave;
+
+	if ((chan->chan_id == param->chan_id) && (param->dma_dev ==
+						  chan->device->dev)) {
+		chan->private = param;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+static void pch_request_dma(struct uart_port *port)
+{
+	dma_cap_mask_t mask;
+	struct dma_chan *chan;
+	struct pci_dev *dma_dev;
+	struct pch_dma_slave *param;
+	struct eg20t_port *priv =
+				container_of(port, struct eg20t_port, port);
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	/* Get DMA's dev information */
+	dma_dev = pci_get_slot(priv->pdev->bus,
+			PCI_DEVFN(PCI_SLOT(priv->pdev->devfn), 0));
+
+	/* Set Tx DMA */
+	param = &priv->param_tx;
+	param->dma_dev = &dma_dev->dev;
+	param->chan_id = priv->port.line * 2; /* Tx = 0, 2, 4, ... */
+
+	param->tx_reg = port->mapbase + UART_TX;
+	chan = dma_request_channel(mask, filter, param);
+	if (!chan) {
+		dev_err(priv->port.dev, "%s:dma_request_channel FAILS(Tx)\n",
+			__func__);
+		pci_dev_put(dma_dev);
+		return;
+	}
+	priv->chan_tx = chan;
+
+	/* Set Rx DMA */
+	param = &priv->param_rx;
+	param->dma_dev = &dma_dev->dev;
+	param->chan_id = priv->port.line * 2 + 1; /* Rx = Tx + 1 */
+
+	param->rx_reg = port->mapbase + UART_RX;
+	chan = dma_request_channel(mask, filter, param);
+	if (!chan) {
+		dev_err(priv->port.dev, "%s:dma_request_channel FAILS(Rx)\n",
+			__func__);
+		dma_release_channel(priv->chan_tx);
+		priv->chan_tx = NULL;
+		pci_dev_put(dma_dev);
+		return;
+	}
+
+	/* Get Consistent memory for DMA */
+	priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize,
+				    &priv->rx_buf_dma, GFP_KERNEL);
+	priv->chan_rx = chan;
+
+	pci_dev_put(dma_dev);
+}
+
+static void pch_dma_rx_complete(void *arg)
+{
+	struct eg20t_port *priv = arg;
+	struct uart_port *port = &priv->port;
+	int count;
+
+	dma_sync_sg_for_cpu(port->dev, &priv->sg_rx, 1, DMA_FROM_DEVICE);
+	count = dma_push_rx(priv, priv->trigger_level);
+	if (count)
+		tty_flip_buffer_push(&port->state->port);
+	async_tx_ack(priv->desc_rx);
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_RX_INT |
+					    PCH_UART_HAL_RX_ERR_INT);
+}
+
+static void pch_dma_tx_complete(void *arg)
+{
+	struct eg20t_port *priv = arg;
+	struct uart_port *port = &priv->port;
+	struct scatterlist *sg = priv->sg_tx_p;
+	int i;
+
+	for (i = 0; i < priv->nent; i++, sg++)
+		uart_xmit_advance(port, sg_dma_len(sg));
+
+	async_tx_ack(priv->desc_tx);
+	dma_unmap_sg(port->dev, priv->sg_tx_p, priv->orig_nent, DMA_TO_DEVICE);
+	priv->tx_dma_use = 0;
+	priv->nent = 0;
+	priv->orig_nent = 0;
+	kfree(priv->sg_tx_p);
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
+}
+
+static int handle_rx_to(struct eg20t_port *priv)
+{
+	struct pch_uart_buffer *buf;
+	int rx_size;
+	int ret;
+	if (!priv->start_rx) {
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_RX_INT |
+						     PCH_UART_HAL_RX_ERR_INT);
+		return 0;
+	}
+	buf = &priv->rxbuf;
+	do {
+		rx_size = pch_uart_hal_read(priv, buf->buf, buf->size);
+		ret = push_rx(priv, buf->buf, rx_size);
+		if (ret)
+			return 0;
+	} while (rx_size == buf->size);
+
+	return PCH_UART_HANDLED_RX_INT;
+}
+
+static int handle_rx(struct eg20t_port *priv)
+{
+	return handle_rx_to(priv);
+}
+
+static int dma_handle_rx(struct eg20t_port *priv)
+{
+	struct uart_port *port = &priv->port;
+	struct dma_async_tx_descriptor *desc;
+	struct scatterlist *sg;
+
+	priv = container_of(port, struct eg20t_port, port);
+	sg = &priv->sg_rx;
+
+	sg_init_table(&priv->sg_rx, 1); /* Initialize SG table */
+
+	sg_dma_len(sg) = priv->trigger_level;
+
+	sg_set_page(&priv->sg_rx, virt_to_page(priv->rx_buf_virt),
+		     sg_dma_len(sg), offset_in_page(priv->rx_buf_virt));
+
+	sg_dma_address(sg) = priv->rx_buf_dma;
+
+	desc = dmaengine_prep_slave_sg(priv->chan_rx,
+			sg, 1, DMA_DEV_TO_MEM,
+			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+
+	if (!desc)
+		return 0;
+
+	priv->desc_rx = desc;
+	desc->callback = pch_dma_rx_complete;
+	desc->callback_param = priv;
+	desc->tx_submit(desc);
+	dma_async_issue_pending(priv->chan_rx);
+
+	return PCH_UART_HANDLED_RX_INT;
+}
+
+static unsigned int handle_tx(struct eg20t_port *priv)
+{
+	struct uart_port *port = &priv->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	int fifo_size;
+	int tx_empty;
+
+	if (!priv->start_tx) {
+		dev_info(priv->port.dev, "%s:Tx isn't started. (%lu)\n",
+			__func__, jiffies);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		priv->tx_empty = 1;
+		return 0;
+	}
+
+	fifo_size = max(priv->fifo_size, 1);
+	tx_empty = 1;
+	if (port->x_char) {
+		iowrite8(port->x_char, priv->membase + PCH_UART_THR);
+		port->icount.tx++;
+		port->x_char = 0;
+		tx_empty = 0;
+		fifo_size--;
+	}
+
+	while (!uart_tx_stopped(port) && !uart_circ_empty(xmit) && fifo_size) {
+		iowrite8(xmit->buf[xmit->tail], priv->membase + PCH_UART_THR);
+		uart_xmit_advance(port, 1);
+		fifo_size--;
+		tx_empty = 0;
+	}
+
+	priv->tx_empty = tx_empty;
+
+	if (tx_empty) {
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		uart_write_wakeup(port);
+	}
+
+	return PCH_UART_HANDLED_TX_INT;
+}
+
+static unsigned int dma_handle_tx(struct eg20t_port *priv)
+{
+	struct uart_port *port = &priv->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct scatterlist *sg;
+	int nent;
+	int fifo_size;
+	struct dma_async_tx_descriptor *desc;
+	int num;
+	int i;
+	int bytes;
+	int size;
+	int rem;
+
+	if (!priv->start_tx) {
+		dev_info(priv->port.dev, "%s:Tx isn't started. (%lu)\n",
+			__func__, jiffies);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		priv->tx_empty = 1;
+		return 0;
+	}
+
+	if (priv->tx_dma_use) {
+		dev_dbg(priv->port.dev, "%s:Tx is not completed. (%lu)\n",
+			__func__, jiffies);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		priv->tx_empty = 1;
+		return 0;
+	}
+
+	fifo_size = max(priv->fifo_size, 1);
+
+	if (port->x_char) {
+		iowrite8(port->x_char, priv->membase + PCH_UART_THR);
+		port->icount.tx++;
+		port->x_char = 0;
+		fifo_size--;
+	}
+
+	bytes = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (!bytes) {
+		dev_dbg(priv->port.dev, "%s 0 bytes return\n", __func__);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		uart_write_wakeup(port);
+		return 0;
+	}
+
+	if (bytes > fifo_size) {
+		num = bytes / fifo_size + 1;
+		size = fifo_size;
+		rem = bytes % fifo_size;
+	} else {
+		num = 1;
+		size = bytes;
+		rem = bytes;
+	}
+
+	dev_dbg(priv->port.dev, "%s num=%d size=%d rem=%d\n",
+		__func__, num, size, rem);
+
+	priv->tx_dma_use = 1;
+
+	priv->sg_tx_p = kmalloc_array(num, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!priv->sg_tx_p) {
+		dev_err(priv->port.dev, "%s:kzalloc Failed\n", __func__);
+		return 0;
+	}
+
+	sg_init_table(priv->sg_tx_p, num); /* Initialize SG table */
+	sg = priv->sg_tx_p;
+
+	for (i = 0; i < num; i++, sg++) {
+		if (i == (num - 1))
+			sg_set_page(sg, virt_to_page(xmit->buf),
+				    rem, fifo_size * i);
+		else
+			sg_set_page(sg, virt_to_page(xmit->buf),
+				    size, fifo_size * i);
+	}
+
+	sg = priv->sg_tx_p;
+	nent = dma_map_sg(port->dev, sg, num, DMA_TO_DEVICE);
+	if (!nent) {
+		dev_err(priv->port.dev, "%s:dma_map_sg Failed\n", __func__);
+		return 0;
+	}
+	priv->orig_nent = num;
+	priv->nent = nent;
+
+	for (i = 0; i < nent; i++, sg++) {
+		sg->offset = (xmit->tail & (UART_XMIT_SIZE - 1)) +
+			      fifo_size * i;
+		sg_dma_address(sg) = (sg_dma_address(sg) &
+				    ~(UART_XMIT_SIZE - 1)) + sg->offset;
+		if (i == (nent - 1))
+			sg_dma_len(sg) = rem;
+		else
+			sg_dma_len(sg) = size;
+	}
+
+	desc = dmaengine_prep_slave_sg(priv->chan_tx,
+					priv->sg_tx_p, nent, DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dev_err(priv->port.dev, "%s:dmaengine_prep_slave_sg Failed\n",
+			__func__);
+		return 0;
+	}
+	dma_sync_sg_for_device(port->dev, priv->sg_tx_p, nent, DMA_TO_DEVICE);
+	priv->desc_tx = desc;
+	desc->callback = pch_dma_tx_complete;
+	desc->callback_param = priv;
+
+	desc->tx_submit(desc);
+
+	dma_async_issue_pending(priv->chan_tx);
+
+	return PCH_UART_HANDLED_TX_INT;
+}
+
+static void pch_uart_err_ir(struct eg20t_port *priv, unsigned int lsr)
+{
+	struct uart_port *port = &priv->port;
+	struct tty_struct *tty = tty_port_tty_get(&port->state->port);
+	char   *error_msg[5] = {};
+	int    i = 0;
+
+	if (lsr & PCH_UART_LSR_ERR)
+		error_msg[i++] = "Error data in FIFO\n";
+
+	if (lsr & UART_LSR_FE) {
+		port->icount.frame++;
+		error_msg[i++] = "  Framing Error\n";
+	}
+
+	if (lsr & UART_LSR_PE) {
+		port->icount.parity++;
+		error_msg[i++] = "  Parity Error\n";
+	}
+
+	if (lsr & UART_LSR_OE) {
+		port->icount.overrun++;
+		error_msg[i++] = "  Overrun Error\n";
+	}
+
+	if (tty == NULL) {
+		for (i = 0; error_msg[i] != NULL; i++)
+			dev_err(&priv->pdev->dev, error_msg[i]);
+	} else {
+		tty_kref_put(tty);
+	}
+}
+
+static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
+{
+	struct eg20t_port *priv = dev_id;
+	unsigned int handled;
+	u8 lsr;
+	int ret = 0;
+	unsigned char iid;
+	unsigned long flags;
+	int next = 1;
+	u8 msr;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	handled = 0;
+	while (next) {
+		iid = pch_uart_hal_get_iid(priv);
+		if (iid & PCH_UART_IIR_IP) /* No Interrupt */
+			break;
+		switch (iid) {
+		case PCH_UART_IID_RLS:	/* Receiver Line Status */
+			lsr = pch_uart_hal_get_line_status(priv);
+			if (lsr & (PCH_UART_LSR_ERR | UART_LSR_FE |
+						UART_LSR_PE | UART_LSR_OE)) {
+				pch_uart_err_ir(priv, lsr);
+				ret = PCH_UART_HANDLED_RX_ERR_INT;
+			} else {
+				ret = PCH_UART_HANDLED_LS_INT;
+			}
+			break;
+		case PCH_UART_IID_RDR:	/* Received Data Ready */
+			if (priv->use_dma) {
+				pch_uart_hal_disable_interrupt(priv,
+						PCH_UART_HAL_RX_INT |
+						PCH_UART_HAL_RX_ERR_INT);
+				ret = dma_handle_rx(priv);
+				if (!ret)
+					pch_uart_hal_enable_interrupt(priv,
+						PCH_UART_HAL_RX_INT |
+						PCH_UART_HAL_RX_ERR_INT);
+			} else {
+				ret = handle_rx(priv);
+			}
+			break;
+		case PCH_UART_IID_RDR_TO:	/* Received Data Ready
+						   (FIFO Timeout) */
+			ret = handle_rx_to(priv);
+			break;
+		case PCH_UART_IID_THRE:	/* Transmitter Holding Register
+						   Empty */
+			if (priv->use_dma)
+				ret = dma_handle_tx(priv);
+			else
+				ret = handle_tx(priv);
+			break;
+		case PCH_UART_IID_MS:	/* Modem Status */
+			msr = pch_uart_hal_get_modem(priv);
+			next = 0; /* MS ir prioirty is the lowest. So, MS ir
+				     means final interrupt */
+			if ((msr & UART_MSR_ANY_DELTA) == 0)
+				break;
+			ret |= PCH_UART_HANDLED_MS_INT;
+			break;
+		default:	/* Never junp to this label */
+			dev_err(priv->port.dev, "%s:iid=%02x (%lu)\n", __func__,
+				iid, jiffies);
+			ret = -1;
+			next = 0;
+			break;
+		}
+		handled |= (unsigned int)ret;
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+	return IRQ_RETVAL(handled);
+}
+
+/* This function tests whether the transmitter fifo and shifter for the port
+						described by 'port' is empty. */
+static unsigned int pch_uart_tx_empty(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	if (priv->tx_empty)
+		return TIOCSER_TEMT;
+	else
+		return 0;
+}
+
+/* Returns the current state of modem control inputs. */
+static unsigned int pch_uart_get_mctrl(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	u8 modem;
+	unsigned int ret = 0;
+
+	priv = container_of(port, struct eg20t_port, port);
+	modem = pch_uart_hal_get_modem(priv);
+
+	if (modem & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+
+	if (modem & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+
+	if (modem & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+
+	if (modem & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+
+	return ret;
+}
+
+static void pch_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 mcr = 0;
+	struct eg20t_port *priv = container_of(port, struct eg20t_port, port);
+
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	if (priv->mcr & UART_MCR_AFE)
+		mcr |= UART_MCR_AFE;
+
+	if (mctrl)
+		iowrite8(mcr, priv->membase + UART_MCR);
+}
+
+static void pch_uart_stop_tx(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+	priv->start_tx = 0;
+	priv->tx_dma_use = 0;
+}
+
+static void pch_uart_start_tx(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+
+	if (priv->use_dma) {
+		if (priv->tx_dma_use) {
+			dev_dbg(priv->port.dev, "%s : Tx DMA is NOT empty.\n",
+				__func__);
+			return;
+		}
+	}
+
+	priv->start_tx = 1;
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
+}
+
+static void pch_uart_stop_rx(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+	priv->start_rx = 0;
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_RX_INT |
+					     PCH_UART_HAL_RX_ERR_INT);
+}
+
+/* Enable the modem status interrupts. */
+static void pch_uart_enable_ms(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_MS_INT);
+}
+
+/* Control the transmission of a break signal. */
+static void pch_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	struct eg20t_port *priv;
+	unsigned long flags;
+
+	priv = container_of(port, struct eg20t_port, port);
+	spin_lock_irqsave(&priv->lock, flags);
+	pch_uart_hal_set_break(priv, ctl);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+/* Grab any interrupt resources and initialise any low level driver state. */
+static int pch_uart_startup(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	int ret;
+	int fifo_size;
+	int trigger_level;
+
+	priv = container_of(port, struct eg20t_port, port);
+	priv->tx_empty = 1;
+
+	if (port->uartclk)
+		priv->uartclk = port->uartclk;
+	else
+		port->uartclk = priv->uartclk;
+
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+	ret = pch_uart_hal_set_line(priv, default_baud,
+			      PCH_UART_HAL_PARITY_NONE, PCH_UART_HAL_8BIT,
+			      PCH_UART_HAL_STB1);
+	if (ret)
+		return ret;
+
+	switch (priv->fifo_size) {
+	case 256:
+		fifo_size = PCH_UART_HAL_FIFO256;
+		break;
+	case 64:
+		fifo_size = PCH_UART_HAL_FIFO64;
+		break;
+	case 16:
+		fifo_size = PCH_UART_HAL_FIFO16;
+		break;
+	case 1:
+	default:
+		fifo_size = PCH_UART_HAL_FIFO_DIS;
+		break;
+	}
+
+	switch (priv->trigger) {
+	case PCH_UART_HAL_TRIGGER1:
+		trigger_level = 1;
+		break;
+	case PCH_UART_HAL_TRIGGER_L:
+		trigger_level = priv->fifo_size / 4;
+		break;
+	case PCH_UART_HAL_TRIGGER_M:
+		trigger_level = priv->fifo_size / 2;
+		break;
+	case PCH_UART_HAL_TRIGGER_H:
+	default:
+		trigger_level = priv->fifo_size - (priv->fifo_size / 8);
+		break;
+	}
+
+	priv->trigger_level = trigger_level;
+	ret = pch_uart_hal_set_fifo(priv, PCH_UART_HAL_DMA_MODE0,
+				    fifo_size, priv->trigger);
+	if (ret < 0)
+		return ret;
+
+	ret = request_irq(priv->port.irq, pch_uart_interrupt, IRQF_SHARED,
+			priv->irq_name, priv);
+	if (ret < 0)
+		return ret;
+
+	if (priv->use_dma)
+		pch_request_dma(port);
+
+	priv->start_rx = 1;
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_RX_INT |
+					    PCH_UART_HAL_RX_ERR_INT);
+	uart_update_timeout(port, CS8, default_baud);
+
+	return 0;
+}
+
+static void pch_uart_shutdown(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	int ret;
+
+	priv = container_of(port, struct eg20t_port, port);
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+	pch_uart_hal_fifo_reset(priv, PCH_UART_HAL_CLR_ALL_FIFO);
+	ret = pch_uart_hal_set_fifo(priv, PCH_UART_HAL_DMA_MODE0,
+			      PCH_UART_HAL_FIFO_DIS, PCH_UART_HAL_TRIGGER1);
+	if (ret)
+		dev_err(priv->port.dev,
+			"pch_uart_hal_set_fifo Failed(ret=%d)\n", ret);
+
+	pch_free_dma(port);
+
+	free_irq(priv->port.irq, priv);
+}
+
+/* Change the port parameters, including word length, parity, stop
+ *bits.  Update read_status_mask and ignore_status_mask to indicate
+ *the types of events we are interested in receiving.  */
+static void pch_uart_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	int rtn;
+	unsigned int baud, parity, bits, stb;
+	struct eg20t_port *priv;
+	unsigned long flags;
+
+	priv = container_of(port, struct eg20t_port, port);
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		bits = PCH_UART_HAL_5BIT;
+		break;
+	case CS6:
+		bits = PCH_UART_HAL_6BIT;
+		break;
+	case CS7:
+		bits = PCH_UART_HAL_7BIT;
+		break;
+	default:		/* CS8 */
+		bits = PCH_UART_HAL_8BIT;
+		break;
+	}
+	if (termios->c_cflag & CSTOPB)
+		stb = PCH_UART_HAL_STB2;
+	else
+		stb = PCH_UART_HAL_STB1;
+
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & PARODD)
+			parity = PCH_UART_HAL_PARITY_ODD;
+		else
+			parity = PCH_UART_HAL_PARITY_EVEN;
+
+	} else
+		parity = PCH_UART_HAL_PARITY_NONE;
+
+	/* Only UART0 has auto hardware flow function */
+	if ((termios->c_cflag & CRTSCTS) && (priv->fifo_size == 256))
+		priv->mcr |= UART_MCR_AFE;
+	else
+		priv->mcr &= ~UART_MCR_AFE;
+
+	termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	spin_lock(&port->lock);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	rtn = pch_uart_hal_set_line(priv, baud, parity, bits, stb);
+	if (rtn)
+		goto out;
+
+	pch_uart_set_mctrl(&priv->port, priv->port.mctrl);
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+out:
+	spin_unlock(&port->lock);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static const char *pch_uart_type(struct uart_port *port)
+{
+	return KBUILD_MODNAME;
+}
+
+static void pch_uart_release_port(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	pci_iounmap(priv->pdev, priv->membase);
+	pci_release_regions(priv->pdev);
+}
+
+static int pch_uart_request_port(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	int ret;
+	void __iomem *membase;
+
+	priv = container_of(port, struct eg20t_port, port);
+	ret = pci_request_regions(priv->pdev, KBUILD_MODNAME);
+	if (ret < 0)
+		return -EBUSY;
+
+	membase = pci_iomap(priv->pdev, 1, 0);
+	if (!membase) {
+		pci_release_regions(priv->pdev);
+		return -EBUSY;
+	}
+	priv->membase = port->membase = membase;
+
+	return 0;
+}
+
+static void pch_uart_config_port(struct uart_port *port, int type)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	if (type & UART_CONFIG_TYPE) {
+		port->type = priv->port_type;
+		pch_uart_request_port(port);
+	}
+}
+
+static int pch_uart_verify_port(struct uart_port *port,
+				struct serial_struct *serinfo)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	if (serinfo->flags & UPF_LOW_LATENCY) {
+		dev_info(priv->port.dev,
+			"PCH UART : Use PIO Mode (without DMA)\n");
+		priv->use_dma = 0;
+		serinfo->flags &= ~UPF_LOW_LATENCY;
+	} else {
+#ifndef CONFIG_PCH_DMA
+		dev_err(priv->port.dev, "%s : PCH DMA is not Loaded.\n",
+			__func__);
+		return -EOPNOTSUPP;
+#endif
+		if (!priv->use_dma) {
+			pch_request_dma(port);
+			if (priv->chan_rx)
+				priv->use_dma = 1;
+		}
+		dev_info(priv->port.dev, "PCH UART: %s\n",
+				priv->use_dma ?
+				"Use DMA Mode" : "No DMA");
+	}
+
+	return 0;
+}
+
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_PCH_UART_CONSOLE)
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct eg20t_port *up, int bits)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	for (;;) {
+		status = ioread8(up->membase + UART_LSR);
+
+		if ((status & bits) == bits)
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	}
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		unsigned int tmout;
+		for (tmout = 1000000; tmout; tmout--) {
+			unsigned int msr = ioread8(up->membase + UART_MSR);
+			if (msr & UART_MSR_CTS)
+				break;
+			udelay(1);
+			touch_nmi_watchdog();
+		}
+	}
+}
+#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_PCH_UART_CONSOLE */
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for communicate via uart while
+ * in an interrupt or debug context.
+ */
+static int pch_uart_get_poll_char(struct uart_port *port)
+{
+	struct eg20t_port *priv =
+		container_of(port, struct eg20t_port, port);
+	u8 lsr = ioread8(priv->membase + UART_LSR);
+
+	if (!(lsr & UART_LSR_DR))
+		return NO_POLL_CHAR;
+
+	return ioread8(priv->membase + PCH_UART_RBR);
+}
+
+
+static void pch_uart_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct eg20t_port *priv =
+		container_of(port, struct eg20t_port, port);
+
+	/*
+	 * First save the IER then disable the interrupts
+	 */
+	ier = ioread8(priv->membase + UART_IER);
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+
+	wait_for_xmitr(priv, UART_LSR_THRE);
+	/*
+	 * Send the character out.
+	 */
+	iowrite8(c, priv->membase + PCH_UART_THR);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore the IER
+	 */
+	wait_for_xmitr(priv, UART_LSR_BOTH_EMPTY);
+	iowrite8(ier, priv->membase + UART_IER);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops pch_uart_ops = {
+	.tx_empty = pch_uart_tx_empty,
+	.set_mctrl = pch_uart_set_mctrl,
+	.get_mctrl = pch_uart_get_mctrl,
+	.stop_tx = pch_uart_stop_tx,
+	.start_tx = pch_uart_start_tx,
+	.stop_rx = pch_uart_stop_rx,
+	.enable_ms = pch_uart_enable_ms,
+	.break_ctl = pch_uart_break_ctl,
+	.startup = pch_uart_startup,
+	.shutdown = pch_uart_shutdown,
+	.set_termios = pch_uart_set_termios,
+/*	.pm		= pch_uart_pm,		Not supported yet */
+	.type = pch_uart_type,
+	.release_port = pch_uart_release_port,
+	.request_port = pch_uart_request_port,
+	.config_port = pch_uart_config_port,
+	.verify_port = pch_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = pch_uart_get_poll_char,
+	.poll_put_char = pch_uart_put_poll_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+
+static void pch_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct eg20t_port *priv =
+		container_of(port, struct eg20t_port, port);
+
+	wait_for_xmitr(priv, UART_LSR_THRE);
+	iowrite8(ch, priv->membase + PCH_UART_THR);
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ */
+static void
+pch_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct eg20t_port *priv;
+	unsigned long flags;
+	int priv_locked = 1;
+	int port_locked = 1;
+	u8 ier;
+
+	priv = pch_uart_ports[co->index];
+
+	touch_nmi_watchdog();
+
+	local_irq_save(flags);
+	if (priv->port.sysrq) {
+		/* call to uart_handle_sysrq_char already took the priv lock */
+		priv_locked = 0;
+		/* serial8250_handle_port() already took the port lock */
+		port_locked = 0;
+	} else if (oops_in_progress) {
+		priv_locked = spin_trylock(&priv->lock);
+		port_locked = spin_trylock(&priv->port.lock);
+	} else {
+		spin_lock(&priv->lock);
+		spin_lock(&priv->port.lock);
+	}
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = ioread8(priv->membase + UART_IER);
+
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+
+	uart_console_write(&priv->port, s, count, pch_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(priv, UART_LSR_BOTH_EMPTY);
+	iowrite8(ier, priv->membase + UART_IER);
+
+	if (port_locked)
+		spin_unlock(&priv->port.lock);
+	if (priv_locked)
+		spin_unlock(&priv->lock);
+	local_irq_restore(flags);
+}
+
+static int __init pch_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = default_baud;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= PCH_UART_NR)
+		co->index = 0;
+	port = &pch_uart_ports[co->index]->port;
+
+	if (!port || (!port->iobase && !port->membase))
+		return -ENODEV;
+
+	port->uartclk = pch_uart_get_uartclk();
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver pch_uart_driver;
+
+static struct console pch_console = {
+	.name		= PCH_UART_DRIVER_DEVICE,
+	.write		= pch_console_write,
+	.device		= uart_console_device,
+	.setup		= pch_console_setup,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+	.index		= -1,
+	.data		= &pch_uart_driver,
+};
+
+#define PCH_CONSOLE	(&pch_console)
+#else
+#define PCH_CONSOLE	NULL
+#endif	/* CONFIG_SERIAL_PCH_UART_CONSOLE */
+
+static struct uart_driver pch_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = KBUILD_MODNAME,
+	.dev_name = PCH_UART_DRIVER_DEVICE,
+	.major = 0,
+	.minor = 0,
+	.nr = PCH_UART_NR,
+	.cons = PCH_CONSOLE,
+};
+
+static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
+					     const struct pci_device_id *id)
+{
+	struct eg20t_port *priv;
+	int ret;
+	unsigned int iobase;
+	unsigned int mapbase;
+	unsigned char *rxbuf;
+	int fifosize;
+	int port_type;
+	struct pch_uart_driver_data *board;
+	char name[32];
+
+	board = &drv_dat[id->driver_data];
+	port_type = board->port_type;
+
+	priv = kzalloc(sizeof(struct eg20t_port), GFP_KERNEL);
+	if (priv == NULL)
+		goto init_port_alloc_err;
+
+	rxbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
+	if (!rxbuf)
+		goto init_port_free_txbuf;
+
+	switch (port_type) {
+	case PORT_PCH_8LINE:
+		fifosize = 256; /* EG20T/ML7213: UART0 */
+		break;
+	case PORT_PCH_2LINE:
+		fifosize = 64; /* EG20T:UART1~3  ML7213: UART1~2*/
+		break;
+	default:
+		dev_err(&pdev->dev, "Invalid Port Type(=%d)\n", port_type);
+		goto init_port_hal_free;
+	}
+
+	pci_enable_msi(pdev);
+	pci_set_master(pdev);
+
+	spin_lock_init(&priv->lock);
+
+	iobase = pci_resource_start(pdev, 0);
+	mapbase = pci_resource_start(pdev, 1);
+	priv->mapbase = mapbase;
+	priv->iobase = iobase;
+	priv->pdev = pdev;
+	priv->tx_empty = 1;
+	priv->rxbuf.buf = rxbuf;
+	priv->rxbuf.size = PAGE_SIZE;
+
+	priv->fifo_size = fifosize;
+	priv->uartclk = pch_uart_get_uartclk();
+	priv->port_type = port_type;
+	priv->port.dev = &pdev->dev;
+	priv->port.iobase = iobase;
+	priv->port.membase = NULL;
+	priv->port.mapbase = mapbase;
+	priv->port.irq = pdev->irq;
+	priv->port.iotype = UPIO_PORT;
+	priv->port.ops = &pch_uart_ops;
+	priv->port.flags = UPF_BOOT_AUTOCONF;
+	priv->port.fifosize = fifosize;
+	priv->port.line = board->line_no;
+	priv->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_PCH_UART_CONSOLE);
+	priv->trigger = PCH_UART_HAL_TRIGGER_M;
+
+	snprintf(priv->irq_name, IRQ_NAME_SIZE,
+		 KBUILD_MODNAME ":" PCH_UART_DRIVER_DEVICE "%d",
+		 priv->port.line);
+
+	spin_lock_init(&priv->port.lock);
+
+	pci_set_drvdata(pdev, priv);
+	priv->trigger_level = 1;
+	priv->fcr = 0;
+
+	if (pdev->dev.of_node)
+		of_property_read_u32(pdev->dev.of_node, "clock-frequency"
+					 , &user_uartclk);
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+	pch_uart_ports[board->line_no] = priv;
+#endif
+	ret = uart_add_one_port(&pch_uart_driver, &priv->port);
+	if (ret < 0)
+		goto init_port_hal_free;
+
+	snprintf(name, sizeof(name), "uart%d_regs", priv->port.line);
+	debugfs_create_file(name, S_IFREG | S_IRUGO, NULL, priv,
+			    &port_regs_ops);
+
+	return priv;
+
+init_port_hal_free:
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+	pch_uart_ports[board->line_no] = NULL;
+#endif
+	free_page((unsigned long)rxbuf);
+init_port_free_txbuf:
+	kfree(priv);
+init_port_alloc_err:
+
+	return NULL;
+}
+
+static void pch_uart_exit_port(struct eg20t_port *priv)
+{
+	char name[32];
+
+	snprintf(name, sizeof(name), "uart%d_regs", priv->port.line);
+	debugfs_lookup_and_remove(name, NULL);
+	uart_remove_one_port(&pch_uart_driver, &priv->port);
+	free_page((unsigned long)priv->rxbuf.buf);
+}
+
+static void pch_uart_pci_remove(struct pci_dev *pdev)
+{
+	struct eg20t_port *priv = pci_get_drvdata(pdev);
+
+	pci_disable_msi(pdev);
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+	pch_uart_ports[priv->port.line] = NULL;
+#endif
+	pch_uart_exit_port(priv);
+	pci_disable_device(pdev);
+	kfree(priv);
+	return;
+}
+
+static int __maybe_unused pch_uart_pci_suspend(struct device *dev)
+{
+	struct eg20t_port *priv = dev_get_drvdata(dev);
+
+	uart_suspend_port(&pch_uart_driver, &priv->port);
+
+	return 0;
+}
+
+static int __maybe_unused pch_uart_pci_resume(struct device *dev)
+{
+	struct eg20t_port *priv = dev_get_drvdata(dev);
+
+	uart_resume_port(&pch_uart_driver, &priv->port);
+
+	return 0;
+}
+
+static const struct pci_device_id pch_uart_pci_id[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8811),
+	 .driver_data = pch_et20t_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8812),
+	 .driver_data = pch_et20t_uart1},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8813),
+	 .driver_data = pch_et20t_uart2},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8814),
+	 .driver_data = pch_et20t_uart3},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8027),
+	 .driver_data = pch_ml7213_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8028),
+	 .driver_data = pch_ml7213_uart1},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8029),
+	 .driver_data = pch_ml7213_uart2},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x800C),
+	 .driver_data = pch_ml7223_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x800D),
+	 .driver_data = pch_ml7223_uart1},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8811),
+	 .driver_data = pch_ml7831_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8812),
+	 .driver_data = pch_ml7831_uart1},
+	{0,},
+};
+
+static int pch_uart_pci_probe(struct pci_dev *pdev,
+					const struct pci_device_id *id)
+{
+	int ret;
+	struct eg20t_port *priv;
+
+	ret = pci_enable_device(pdev);
+	if (ret < 0)
+		goto probe_error;
+
+	priv = pch_uart_init_port(pdev, id);
+	if (!priv) {
+		ret = -EBUSY;
+		goto probe_disable_device;
+	}
+	pci_set_drvdata(pdev, priv);
+
+	return ret;
+
+probe_disable_device:
+	pci_disable_msi(pdev);
+	pci_disable_device(pdev);
+probe_error:
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(pch_uart_pci_pm_ops,
+			 pch_uart_pci_suspend,
+			 pch_uart_pci_resume);
+
+static struct pci_driver pch_uart_pci_driver = {
+	.name = "pch_uart",
+	.id_table = pch_uart_pci_id,
+	.probe = pch_uart_pci_probe,
+	.remove = pch_uart_pci_remove,
+	.driver.pm = &pch_uart_pci_pm_ops,
+};
+
+static int __init pch_uart_module_init(void)
+{
+	int ret;
+
+	/* register as UART driver */
+	ret = uart_register_driver(&pch_uart_driver);
+	if (ret < 0)
+		return ret;
+
+	/* register as PCI driver */
+	ret = pci_register_driver(&pch_uart_pci_driver);
+	if (ret < 0)
+		uart_unregister_driver(&pch_uart_driver);
+
+	return ret;
+}
+module_init(pch_uart_module_init);
+
+static void __exit pch_uart_module_exit(void)
+{
+	pci_unregister_driver(&pch_uart_pci_driver);
+	uart_unregister_driver(&pch_uart_driver);
+}
+module_exit(pch_uart_module_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel EG20T PCH UART PCI Driver");
+MODULE_DEVICE_TABLE(pci, pch_uart_pci_id);
+
+module_param(default_baud, uint, S_IRUGO);
+MODULE_PARM_DESC(default_baud,
+                 "Default BAUD for initial driver state and console (default 9600)");
+module_param(user_uartclk, uint, S_IRUGO);
+MODULE_PARM_DESC(user_uartclk,
+                 "Override UART default or board specific UART clock");
diff --git a/drivers/tty/serial/pic32_uart.c b/drivers/tty/serial/pic32_uart.c
new file mode 100644
index 000000000..e308d5022
--- /dev/null
+++ b/drivers/tty/serial/pic32_uart.c
@@ -0,0 +1,1004 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PIC32 Integrated Serial Driver.
+ *
+ * Copyright (C) 2015 Microchip Technology, Inc.
+ *
+ * Authors:
+ *   Sorin-Andrei Pistirica <andrei.pistirica@microchip.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+#include <linux/clk.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/delay.h>
+
+#include <asm/mach-pic32/pic32.h>
+
+/* UART name and device definitions */
+#define PIC32_DEV_NAME		"pic32-uart"
+#define PIC32_MAX_UARTS		6
+#define PIC32_SDEV_NAME		"ttyPIC"
+
+#define PIC32_UART_DFLT_BRATE		9600
+#define PIC32_UART_TX_FIFO_DEPTH	8
+#define PIC32_UART_RX_FIFO_DEPTH	8
+
+#define PIC32_UART_MODE		0x00
+#define PIC32_UART_STA		0x10
+#define PIC32_UART_TX		0x20
+#define PIC32_UART_RX		0x30
+#define PIC32_UART_BRG		0x40
+
+/* struct pic32_sport - pic32 serial port descriptor
+ * @port: uart port descriptor
+ * @idx: port index
+ * @irq_fault: virtual fault interrupt number
+ * @irq_fault_name: irq fault name
+ * @irq_rx: virtual rx interrupt number
+ * @irq_rx_name: irq rx name
+ * @irq_tx: virtual tx interrupt number
+ * @irq_tx_name: irq tx name
+ * @cts_gpiod: clear to send GPIO
+ * @dev: device descriptor
+ **/
+struct pic32_sport {
+	struct uart_port port;
+	int idx;
+
+	int irq_fault;
+	const char *irq_fault_name;
+	int irq_rx;
+	const char *irq_rx_name;
+	int irq_tx;
+	const char *irq_tx_name;
+	bool enable_tx_irq;
+
+	struct gpio_desc *cts_gpiod;
+
+	struct clk *clk;
+
+	struct device *dev;
+};
+
+static inline struct pic32_sport *to_pic32_sport(struct uart_port *port)
+{
+	return container_of(port, struct pic32_sport, port);
+}
+
+static inline void pic32_uart_writel(struct pic32_sport *sport,
+					u32 reg, u32 val)
+{
+	__raw_writel(val, sport->port.membase + reg);
+}
+
+static inline u32 pic32_uart_readl(struct pic32_sport *sport, u32 reg)
+{
+	return	__raw_readl(sport->port.membase + reg);
+}
+
+/* pic32 uart mode register bits */
+#define PIC32_UART_MODE_ON        BIT(15)
+#define PIC32_UART_MODE_FRZ       BIT(14)
+#define PIC32_UART_MODE_SIDL      BIT(13)
+#define PIC32_UART_MODE_IREN      BIT(12)
+#define PIC32_UART_MODE_RTSMD     BIT(11)
+#define PIC32_UART_MODE_RESV1     BIT(10)
+#define PIC32_UART_MODE_UEN1      BIT(9)
+#define PIC32_UART_MODE_UEN0      BIT(8)
+#define PIC32_UART_MODE_WAKE      BIT(7)
+#define PIC32_UART_MODE_LPBK      BIT(6)
+#define PIC32_UART_MODE_ABAUD     BIT(5)
+#define PIC32_UART_MODE_RXINV     BIT(4)
+#define PIC32_UART_MODE_BRGH      BIT(3)
+#define PIC32_UART_MODE_PDSEL1    BIT(2)
+#define PIC32_UART_MODE_PDSEL0    BIT(1)
+#define PIC32_UART_MODE_STSEL     BIT(0)
+
+/* pic32 uart status register bits */
+#define PIC32_UART_STA_UTXISEL1   BIT(15)
+#define PIC32_UART_STA_UTXISEL0   BIT(14)
+#define PIC32_UART_STA_UTXINV     BIT(13)
+#define PIC32_UART_STA_URXEN      BIT(12)
+#define PIC32_UART_STA_UTXBRK     BIT(11)
+#define PIC32_UART_STA_UTXEN      BIT(10)
+#define PIC32_UART_STA_UTXBF      BIT(9)
+#define PIC32_UART_STA_TRMT       BIT(8)
+#define PIC32_UART_STA_URXISEL1   BIT(7)
+#define PIC32_UART_STA_URXISEL0   BIT(6)
+#define PIC32_UART_STA_ADDEN      BIT(5)
+#define PIC32_UART_STA_RIDLE      BIT(4)
+#define PIC32_UART_STA_PERR       BIT(3)
+#define PIC32_UART_STA_FERR       BIT(2)
+#define PIC32_UART_STA_OERR       BIT(1)
+#define PIC32_UART_STA_URXDA      BIT(0)
+
+/* pic32_sport pointer for console use */
+static struct pic32_sport *pic32_sports[PIC32_MAX_UARTS];
+
+static inline void pic32_wait_deplete_txbuf(struct pic32_sport *sport)
+{
+	/* wait for tx empty, otherwise chars will be lost or corrupted */
+	while (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_TRMT))
+		udelay(1);
+}
+
+/* serial core request to check if uart tx buffer is empty */
+static unsigned int pic32_uart_tx_empty(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	u32 val = pic32_uart_readl(sport, PIC32_UART_STA);
+
+	return (val & PIC32_UART_STA_TRMT) ? 1 : 0;
+}
+
+/* serial core request to set UART outputs */
+static void pic32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	/* set loopback mode */
+	if (mctrl & TIOCM_LOOP)
+		pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
+					PIC32_UART_MODE_LPBK);
+	else
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_LPBK);
+}
+
+/* serial core request to return the state of misc UART input pins */
+static unsigned int pic32_uart_get_mctrl(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	unsigned int mctrl = 0;
+
+	/* get the state of CTS input pin for this port */
+	if (!sport->cts_gpiod)
+		mctrl |= TIOCM_CTS;
+	else if (gpiod_get_value(sport->cts_gpiod))
+		mctrl |= TIOCM_CTS;
+
+	/* DSR and CD are not supported in PIC32, so return 1
+	 * RI is not supported in PIC32, so return 0
+	 */
+	mctrl |= TIOCM_CD;
+	mctrl |= TIOCM_DSR;
+
+	return mctrl;
+}
+
+/* stop tx and start tx are not called in pairs, therefore a flag indicates
+ * the status of irq to control the irq-depth.
+ */
+static inline void pic32_uart_irqtxen(struct pic32_sport *sport, u8 en)
+{
+	if (en && !sport->enable_tx_irq) {
+		enable_irq(sport->irq_tx);
+		sport->enable_tx_irq = true;
+	} else if (!en && sport->enable_tx_irq) {
+		/* use disable_irq_nosync() and not disable_irq() to avoid self
+		 * imposed deadlock by not waiting for irq handler to end,
+		 * since this callback is called from interrupt context.
+		 */
+		disable_irq_nosync(sport->irq_tx);
+		sport->enable_tx_irq = false;
+	}
+}
+
+/* serial core request to disable tx ASAP (used for flow control) */
+static void pic32_uart_stop_tx(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	if (!(pic32_uart_readl(sport, PIC32_UART_MODE) & PIC32_UART_MODE_ON))
+		return;
+
+	if (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_UTXEN))
+		return;
+
+	/* wait for tx empty */
+	pic32_wait_deplete_txbuf(sport);
+
+	pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+				PIC32_UART_STA_UTXEN);
+	pic32_uart_irqtxen(sport, 0);
+}
+
+/* serial core request to (re)enable tx */
+static void pic32_uart_start_tx(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	pic32_uart_irqtxen(sport, 1);
+	pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA),
+				PIC32_UART_STA_UTXEN);
+}
+
+/* serial core request to stop rx, called before port shutdown */
+static void pic32_uart_stop_rx(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	/* disable rx interrupts */
+	disable_irq(sport->irq_rx);
+
+	/* receiver Enable bit OFF */
+	pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+				PIC32_UART_STA_URXEN);
+}
+
+/* serial core request to start/stop emitting break char */
+static void pic32_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (ctl)
+		pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA),
+					PIC32_UART_STA_UTXBRK);
+	else
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+					PIC32_UART_STA_UTXBRK);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* get port type in string format */
+static const char *pic32_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_PIC32) ? PIC32_DEV_NAME : NULL;
+}
+
+/* read all chars in rx fifo and send them to core */
+static void pic32_uart_do_rx(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	struct tty_port *tty;
+	unsigned int max_count;
+
+	/* limit number of char read in interrupt, should not be
+	 * higher than fifo size anyway since we're much faster than
+	 * serial port
+	 */
+	max_count = PIC32_UART_RX_FIFO_DEPTH;
+
+	spin_lock(&port->lock);
+
+	tty = &port->state->port;
+
+	do {
+		u32 sta_reg, c;
+		char flag;
+
+		/* get overrun/fifo empty information from status register */
+		sta_reg = pic32_uart_readl(sport, PIC32_UART_STA);
+		if (unlikely(sta_reg & PIC32_UART_STA_OERR)) {
+
+			/* fifo reset is required to clear interrupt */
+			pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+						PIC32_UART_STA_OERR);
+
+			port->icount.overrun++;
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		}
+
+		/* Can at least one more character can be read? */
+		if (!(sta_reg & PIC32_UART_STA_URXDA))
+			break;
+
+		/* read the character and increment the rx counter */
+		c = pic32_uart_readl(sport, PIC32_UART_RX);
+
+		port->icount.rx++;
+		flag = TTY_NORMAL;
+		c &= 0xff;
+
+		if (unlikely((sta_reg & PIC32_UART_STA_PERR) ||
+			     (sta_reg & PIC32_UART_STA_FERR))) {
+
+			/* do stats first */
+			if (sta_reg & PIC32_UART_STA_PERR)
+				port->icount.parity++;
+			if (sta_reg & PIC32_UART_STA_FERR)
+				port->icount.frame++;
+
+			/* update flag wrt read_status_mask */
+			sta_reg &= port->read_status_mask;
+
+			if (sta_reg & PIC32_UART_STA_FERR)
+				flag = TTY_FRAME;
+			if (sta_reg & PIC32_UART_STA_PERR)
+				flag = TTY_PARITY;
+		}
+
+		if (uart_handle_sysrq_char(port, c))
+			continue;
+
+		if ((sta_reg & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tty, c, flag);
+
+	} while (--max_count);
+
+	spin_unlock(&port->lock);
+
+	tty_flip_buffer_push(tty);
+}
+
+/* fill tx fifo with chars to send, stop when fifo is about to be full
+ * or when all chars have been sent.
+ */
+static void pic32_uart_do_tx(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int max_count = PIC32_UART_TX_FIFO_DEPTH;
+
+	if (port->x_char) {
+		pic32_uart_writel(sport, PIC32_UART_TX, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_tx_stopped(port)) {
+		pic32_uart_stop_tx(port);
+		return;
+	}
+
+	if (uart_circ_empty(xmit))
+		goto txq_empty;
+
+	/* keep stuffing chars into uart tx buffer
+	 * 1) until uart fifo is full
+	 * or
+	 * 2) until the circ buffer is empty
+	 * (all chars have been sent)
+	 * or
+	 * 3) until the max count is reached
+	 * (prevents lingering here for too long in certain cases)
+	 */
+	while (!(PIC32_UART_STA_UTXBF &
+		pic32_uart_readl(sport, PIC32_UART_STA))) {
+		unsigned int c = xmit->buf[xmit->tail];
+
+		pic32_uart_writel(sport, PIC32_UART_TX, c);
+
+		uart_xmit_advance(port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+		if (--max_count == 0)
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		goto txq_empty;
+
+	return;
+
+txq_empty:
+	pic32_uart_irqtxen(sport, 0);
+}
+
+/* RX interrupt handler */
+static irqreturn_t pic32_uart_rx_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+
+	pic32_uart_do_rx(port);
+
+	return IRQ_HANDLED;
+}
+
+/* TX interrupt handler */
+static irqreturn_t pic32_uart_tx_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	pic32_uart_do_tx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+/* FAULT interrupt handler */
+static irqreturn_t pic32_uart_fault_interrupt(int irq, void *dev_id)
+{
+	/* do nothing: pic32_uart_do_rx() handles faults. */
+	return IRQ_HANDLED;
+}
+
+/* enable rx & tx operation on uart */
+static void pic32_uart_en_and_unmask(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA),
+				PIC32_UART_STA_UTXEN | PIC32_UART_STA_URXEN);
+	pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
+				PIC32_UART_MODE_ON);
+}
+
+/* disable rx & tx operation on uart */
+static void pic32_uart_dsbl_and_mask(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	/* wait for tx empty, otherwise chars will be lost or corrupted */
+	pic32_wait_deplete_txbuf(sport);
+
+	pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+				PIC32_UART_STA_UTXEN | PIC32_UART_STA_URXEN);
+	pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+				PIC32_UART_MODE_ON);
+}
+
+/* serial core request to initialize uart and start rx operation */
+static int pic32_uart_startup(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	u32 dflt_baud = (port->uartclk / PIC32_UART_DFLT_BRATE / 16) - 1;
+	unsigned long flags;
+	int ret;
+
+	local_irq_save(flags);
+
+	ret = clk_prepare_enable(sport->clk);
+	if (ret) {
+		local_irq_restore(flags);
+		goto out_done;
+	}
+
+	/* clear status and mode registers */
+	pic32_uart_writel(sport, PIC32_UART_MODE, 0);
+	pic32_uart_writel(sport, PIC32_UART_STA, 0);
+
+	/* disable uart and mask all interrupts */
+	pic32_uart_dsbl_and_mask(port);
+
+	/* set default baud */
+	pic32_uart_writel(sport, PIC32_UART_BRG, dflt_baud);
+
+	local_irq_restore(flags);
+
+	/* Each UART of a PIC32 has three interrupts therefore,
+	 * we setup driver to register the 3 irqs for the device.
+	 *
+	 * For each irq request_irq() is called with interrupt disabled.
+	 * And the irq is enabled as soon as we are ready to handle them.
+	 */
+	sport->enable_tx_irq = false;
+
+	sport->irq_fault_name = kasprintf(GFP_KERNEL, "%s%d-fault",
+					  pic32_uart_type(port),
+					  sport->idx);
+	if (!sport->irq_fault_name) {
+		dev_err(port->dev, "%s: kasprintf err!", __func__);
+		ret = -ENOMEM;
+		goto out_disable_clk;
+	}
+	irq_set_status_flags(sport->irq_fault, IRQ_NOAUTOEN);
+	ret = request_irq(sport->irq_fault, pic32_uart_fault_interrupt,
+			  IRQF_NO_THREAD, sport->irq_fault_name, port);
+	if (ret) {
+		dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n",
+			__func__, sport->irq_fault, ret,
+			pic32_uart_type(port));
+		goto out_f;
+	}
+
+	sport->irq_rx_name = kasprintf(GFP_KERNEL, "%s%d-rx",
+				       pic32_uart_type(port),
+				       sport->idx);
+	if (!sport->irq_rx_name) {
+		dev_err(port->dev, "%s: kasprintf err!", __func__);
+		ret = -ENOMEM;
+		goto out_f;
+	}
+	irq_set_status_flags(sport->irq_rx, IRQ_NOAUTOEN);
+	ret = request_irq(sport->irq_rx, pic32_uart_rx_interrupt,
+			  IRQF_NO_THREAD, sport->irq_rx_name, port);
+	if (ret) {
+		dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n",
+			__func__, sport->irq_rx, ret,
+			pic32_uart_type(port));
+		goto out_r;
+	}
+
+	sport->irq_tx_name = kasprintf(GFP_KERNEL, "%s%d-tx",
+				       pic32_uart_type(port),
+				       sport->idx);
+	if (!sport->irq_tx_name) {
+		dev_err(port->dev, "%s: kasprintf err!", __func__);
+		ret = -ENOMEM;
+		goto out_r;
+	}
+	irq_set_status_flags(sport->irq_tx, IRQ_NOAUTOEN);
+	ret = request_irq(sport->irq_tx, pic32_uart_tx_interrupt,
+			  IRQF_NO_THREAD, sport->irq_tx_name, port);
+	if (ret) {
+		dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n",
+			__func__, sport->irq_tx, ret,
+			pic32_uart_type(port));
+		goto out_t;
+	}
+
+	local_irq_save(flags);
+
+	/* set rx interrupt on first receive */
+	pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+			PIC32_UART_STA_URXISEL1 | PIC32_UART_STA_URXISEL0);
+
+	/* set interrupt on empty */
+	pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
+			PIC32_UART_STA_UTXISEL1);
+
+	/* enable all interrupts and eanable uart */
+	pic32_uart_en_and_unmask(port);
+
+	local_irq_restore(flags);
+
+	enable_irq(sport->irq_rx);
+
+	return 0;
+
+out_t:
+	free_irq(sport->irq_tx, port);
+	kfree(sport->irq_tx_name);
+out_r:
+	free_irq(sport->irq_rx, port);
+	kfree(sport->irq_rx_name);
+out_f:
+	free_irq(sport->irq_fault, port);
+	kfree(sport->irq_fault_name);
+out_disable_clk:
+	clk_disable_unprepare(sport->clk);
+out_done:
+	return ret;
+}
+
+/* serial core request to flush & disable uart */
+static void pic32_uart_shutdown(struct uart_port *port)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	unsigned long flags;
+
+	/* disable uart */
+	spin_lock_irqsave(&port->lock, flags);
+	pic32_uart_dsbl_and_mask(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+	clk_disable_unprepare(sport->clk);
+
+	/* free all 3 interrupts for this UART */
+	free_irq(sport->irq_fault, port);
+	kfree(sport->irq_fault_name);
+	free_irq(sport->irq_tx, port);
+	kfree(sport->irq_tx_name);
+	free_irq(sport->irq_rx, port);
+	kfree(sport->irq_rx_name);
+}
+
+/* serial core request to change current uart setting */
+static void pic32_uart_set_termios(struct uart_port *port,
+				   struct ktermios *new,
+				   const struct ktermios *old)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+	unsigned int baud;
+	unsigned int quot;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* disable uart and mask all interrupts while changing speed */
+	pic32_uart_dsbl_and_mask(port);
+
+	/* stop bit options */
+	if (new->c_cflag & CSTOPB)
+		pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
+					PIC32_UART_MODE_STSEL);
+	else
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_STSEL);
+
+	/* parity options */
+	if (new->c_cflag & PARENB) {
+		if (new->c_cflag & PARODD) {
+			pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
+					PIC32_UART_MODE_PDSEL1);
+			pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_PDSEL0);
+		} else {
+			pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
+					PIC32_UART_MODE_PDSEL0);
+			pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_PDSEL1);
+		}
+	} else {
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_PDSEL1 |
+					PIC32_UART_MODE_PDSEL0);
+	}
+	/* if hw flow ctrl, then the pins must be specified in device tree */
+	if ((new->c_cflag & CRTSCTS) && sport->cts_gpiod) {
+		/* enable hardware flow control */
+		pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
+					PIC32_UART_MODE_UEN1);
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_UEN0);
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_RTSMD);
+	} else {
+		/* disable hardware flow control */
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_UEN1);
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_UEN0);
+		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE),
+					PIC32_UART_MODE_RTSMD);
+	}
+
+	/* Always 8-bit */
+	new->c_cflag |= CS8;
+
+	/* Mark/Space parity is not supported */
+	new->c_cflag &= ~CMSPAR;
+
+	/* update baud */
+	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+	quot = uart_get_divisor(port, baud) - 1;
+	pic32_uart_writel(sport, PIC32_UART_BRG, quot);
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	if (tty_termios_baud_rate(new))
+		tty_termios_encode_baud_rate(new, baud, baud);
+
+	/* enable uart */
+	pic32_uart_en_and_unmask(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* serial core request to claim uart iomem */
+static int pic32_uart_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res_mem;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!res_mem))
+		return -EINVAL;
+
+	if (!request_mem_region(port->mapbase, resource_size(res_mem),
+				"pic32_uart_mem"))
+		return -EBUSY;
+
+	port->membase = devm_ioremap(port->dev, port->mapbase,
+						resource_size(res_mem));
+	if (!port->membase) {
+		dev_err(port->dev, "Unable to map registers\n");
+		release_mem_region(port->mapbase, resource_size(res_mem));
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/* serial core request to release uart iomem */
+static void pic32_uart_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res_mem;
+	unsigned int res_size;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!res_mem))
+		return;
+	res_size = resource_size(res_mem);
+
+	release_mem_region(port->mapbase, res_size);
+}
+
+/* serial core request to do any port required auto-configuration */
+static void pic32_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		if (pic32_uart_request_port(port))
+			return;
+		port->type = PORT_PIC32;
+	}
+}
+
+/* serial core request to check that port information in serinfo are suitable */
+static int pic32_uart_verify_port(struct uart_port *port,
+				  struct serial_struct *serinfo)
+{
+	if (port->type != PORT_PIC32)
+		return -EINVAL;
+	if (port->irq != serinfo->irq)
+		return -EINVAL;
+	if (port->iotype != serinfo->io_type)
+		return -EINVAL;
+	if (port->mapbase != (unsigned long)serinfo->iomem_base)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* serial core callbacks */
+static const struct uart_ops pic32_uart_ops = {
+	.tx_empty	= pic32_uart_tx_empty,
+	.get_mctrl	= pic32_uart_get_mctrl,
+	.set_mctrl	= pic32_uart_set_mctrl,
+	.start_tx	= pic32_uart_start_tx,
+	.stop_tx	= pic32_uart_stop_tx,
+	.stop_rx	= pic32_uart_stop_rx,
+	.break_ctl	= pic32_uart_break_ctl,
+	.startup	= pic32_uart_startup,
+	.shutdown	= pic32_uart_shutdown,
+	.set_termios	= pic32_uart_set_termios,
+	.type		= pic32_uart_type,
+	.release_port	= pic32_uart_release_port,
+	.request_port	= pic32_uart_request_port,
+	.config_port	= pic32_uart_config_port,
+	.verify_port	= pic32_uart_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_PIC32_CONSOLE
+/* output given char */
+static void pic32_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	if (!(pic32_uart_readl(sport, PIC32_UART_MODE) & PIC32_UART_MODE_ON))
+		return;
+
+	if (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_UTXEN))
+		return;
+
+	/* wait for tx empty */
+	pic32_wait_deplete_txbuf(sport);
+
+	pic32_uart_writel(sport, PIC32_UART_TX, ch & 0xff);
+}
+
+/* console core request to output given string */
+static void pic32_console_write(struct console *co, const char *s,
+				unsigned int count)
+{
+	struct pic32_sport *sport = pic32_sports[co->index];
+
+	/* call uart helper to deal with \r\n */
+	uart_console_write(&sport->port, s, count, pic32_console_putchar);
+}
+
+/* console core request to setup given console, find matching uart
+ * port and setup it.
+ */
+static int pic32_console_setup(struct console *co, char *options)
+{
+	struct pic32_sport *sport;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret = 0;
+
+	if (unlikely(co->index < 0 || co->index >= PIC32_MAX_UARTS))
+		return -ENODEV;
+
+	sport = pic32_sports[co->index];
+	if (!sport)
+		return -ENODEV;
+
+	ret = clk_prepare_enable(sport->clk);
+	if (ret)
+		return ret;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver pic32_uart_driver;
+static struct console pic32_console = {
+	.name		= PIC32_SDEV_NAME,
+	.write		= pic32_console_write,
+	.device		= uart_console_device,
+	.setup		= pic32_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &pic32_uart_driver,
+};
+#define PIC32_SCONSOLE (&pic32_console)
+
+static int __init pic32_console_init(void)
+{
+	register_console(&pic32_console);
+	return 0;
+}
+console_initcall(pic32_console_init);
+
+/*
+ * Late console initialization.
+ */
+static int __init pic32_late_console_init(void)
+{
+	if (!console_is_registered(&pic32_console))
+		register_console(&pic32_console);
+
+	return 0;
+}
+
+core_initcall(pic32_late_console_init);
+
+#else
+#define PIC32_SCONSOLE NULL
+#endif
+
+static struct uart_driver pic32_uart_driver = {
+	.owner			= THIS_MODULE,
+	.driver_name		= PIC32_DEV_NAME,
+	.dev_name		= PIC32_SDEV_NAME,
+	.nr			= PIC32_MAX_UARTS,
+	.cons			= PIC32_SCONSOLE,
+};
+
+static int pic32_uart_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct pic32_sport *sport;
+	int uart_idx = 0;
+	struct resource *res_mem;
+	struct uart_port *port;
+	int ret;
+
+	uart_idx = of_alias_get_id(np, "serial");
+	if (uart_idx < 0 || uart_idx >= PIC32_MAX_UARTS)
+		return -EINVAL;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem)
+		return -EINVAL;
+
+	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	sport->idx		= uart_idx;
+	sport->irq_fault	= irq_of_parse_and_map(np, 0);
+	sport->irq_rx		= irq_of_parse_and_map(np, 1);
+	sport->irq_tx		= irq_of_parse_and_map(np, 2);
+	sport->clk		= devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sport->clk))
+		return PTR_ERR(sport->clk);
+	sport->dev		= &pdev->dev;
+
+	/* Hardware flow control: gpios
+	 * !Note: Basically, CTS is needed for reading the status.
+	 */
+	sport->cts_gpiod = devm_gpiod_get_optional(dev, "cts", GPIOD_IN);
+	if (IS_ERR(sport->cts_gpiod))
+		return dev_err_probe(dev, PTR_ERR(sport->cts_gpiod), "error requesting CTS GPIO\n");
+	gpiod_set_consumer_name(sport->cts_gpiod, "CTS");
+
+	pic32_sports[uart_idx] = sport;
+	port = &sport->port;
+	port->iotype	= UPIO_MEM;
+	port->mapbase	= res_mem->start;
+	port->ops	= &pic32_uart_ops;
+	port->flags	= UPF_BOOT_AUTOCONF;
+	port->dev	= &pdev->dev;
+	port->fifosize	= PIC32_UART_TX_FIFO_DEPTH;
+	port->uartclk	= clk_get_rate(sport->clk);
+	port->line	= uart_idx;
+
+	ret = uart_add_one_port(&pic32_uart_driver, port);
+	if (ret) {
+		port->membase = NULL;
+		dev_err(port->dev, "%s: uart add port error!\n", __func__);
+		goto err;
+	}
+
+#ifdef CONFIG_SERIAL_PIC32_CONSOLE
+	if (uart_console_registered(port)) {
+		/* The peripheral clock has been enabled by console_setup,
+		 * so disable it till the port is used.
+		 */
+		clk_disable_unprepare(sport->clk);
+	}
+#endif
+
+	platform_set_drvdata(pdev, port);
+
+	dev_info(&pdev->dev, "%s: uart(%d) driver initialized.\n",
+		 __func__, uart_idx);
+
+	return 0;
+err:
+	/* automatic unroll of sport and gpios */
+	return ret;
+}
+
+static int pic32_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+	struct pic32_sport *sport = to_pic32_sport(port);
+
+	uart_remove_one_port(&pic32_uart_driver, port);
+	clk_disable_unprepare(sport->clk);
+	platform_set_drvdata(pdev, NULL);
+	pic32_sports[sport->idx] = NULL;
+
+	/* automatic unroll of sport and gpios */
+	return 0;
+}
+
+static const struct of_device_id pic32_serial_dt_ids[] = {
+	{ .compatible = "microchip,pic32mzda-uart" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pic32_serial_dt_ids);
+
+static struct platform_driver pic32_uart_platform_driver = {
+	.probe		= pic32_uart_probe,
+	.remove		= pic32_uart_remove,
+	.driver		= {
+		.name	= PIC32_DEV_NAME,
+		.of_match_table	= of_match_ptr(pic32_serial_dt_ids),
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_PIC32),
+	},
+};
+
+static int __init pic32_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&pic32_uart_driver);
+	if (ret) {
+		pr_err("failed to register %s:%d\n",
+		       pic32_uart_driver.driver_name, ret);
+		return ret;
+	}
+
+	ret = platform_driver_register(&pic32_uart_platform_driver);
+	if (ret) {
+		pr_err("fail to register pic32 uart\n");
+		uart_unregister_driver(&pic32_uart_driver);
+	}
+
+	return ret;
+}
+arch_initcall(pic32_uart_init);
+
+static void __exit pic32_uart_exit(void)
+{
+#ifdef CONFIG_SERIAL_PIC32_CONSOLE
+	unregister_console(&pic32_console);
+#endif
+	platform_driver_unregister(&pic32_uart_platform_driver);
+	uart_unregister_driver(&pic32_uart_driver);
+}
+module_exit(pic32_uart_exit);
+
+MODULE_AUTHOR("Sorin-Andrei Pistirica <andrei.pistirica@microchip.com>");
+MODULE_DESCRIPTION("Microchip PIC32 integrated serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
new file mode 100644
index 000000000..13668ffdb
--- /dev/null
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -0,0 +1,1994 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for PowerMac Z85c30 based ESCC cell found in the
+ * "macio" ASICs of various PowerMac models
+ * 
+ * Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org)
+ *
+ * Derived from drivers/macintosh/macserial.c by Paul Mackerras
+ * and drivers/serial/sunzilog.c by David S. Miller
+ *
+ * Hrm... actually, I ripped most of sunzilog (Thanks David !) and
+ * adapted special tweaks needed for us. I don't think it's worth
+ * merging back those though. The DMA code still has to get in
+ * and once done, I expect that driver to remain fairly stable in
+ * the long term, unless we change the driver model again...
+ *
+ * 2004-08-06 Harald Welte <laforge@gnumonks.org>
+ *	- Enable BREAK interrupt
+ *	- Add support for sysreq
+ *
+ * TODO:   - Add DMA support
+ *         - Defer port shutdown to a few seconds after close
+ *         - maybe put something right into uap->clk_divisor
+ */
+
+#undef DEBUG
+#undef USE_CTRL_O_SYSRQ
+
+#include <linux/module.h>
+#include <linux/tty.h>
+
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <linux/bitops.h>
+#include <linux/sysrq.h>
+#include <linux/mutex.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <asm/sections.h>
+#include <linux/io.h>
+#include <asm/irq.h>
+
+#ifdef CONFIG_PPC_PMAC
+#include <asm/machdep.h>
+#include <asm/pmac_feature.h>
+#include <asm/macio.h>
+#else
+#include <linux/platform_device.h>
+#define of_machine_is_compatible(x) (0)
+#endif
+
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+
+#include "pmac_zilog.h"
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("Driver for the Mac and PowerMac serial ports.");
+MODULE_LICENSE("GPL");
+
+#ifdef CONFIG_SERIAL_PMACZILOG_TTYS
+#define PMACZILOG_MAJOR		TTY_MAJOR
+#define PMACZILOG_MINOR		64
+#define PMACZILOG_NAME		"ttyS"
+#else
+#define PMACZILOG_MAJOR		204
+#define PMACZILOG_MINOR		192
+#define PMACZILOG_NAME		"ttyPZ"
+#endif
+
+#define pmz_debug(fmt, arg...)	pr_debug("ttyPZ%d: " fmt, uap->port.line, ## arg)
+#define pmz_error(fmt, arg...)	pr_err("ttyPZ%d: " fmt, uap->port.line, ## arg)
+#define pmz_info(fmt, arg...)	pr_info("ttyPZ%d: " fmt, uap->port.line, ## arg)
+
+/*
+ * For the sake of early serial console, we can do a pre-probe
+ * (optional) of the ports at rather early boot time.
+ */
+static struct uart_pmac_port	pmz_ports[MAX_ZS_PORTS];
+static int			pmz_ports_count;
+
+static struct uart_driver pmz_uart_reg = {
+	.owner		=	THIS_MODULE,
+	.driver_name	=	PMACZILOG_NAME,
+	.dev_name	=	PMACZILOG_NAME,
+	.major		=	PMACZILOG_MAJOR,
+	.minor		=	PMACZILOG_MINOR,
+};
+
+
+/* 
+ * Load all registers to reprogram the port
+ * This function must only be called when the TX is not busy.  The UART
+ * port lock must be held and local interrupts disabled.
+ */
+static void pmz_load_zsregs(struct uart_pmac_port *uap, u8 *regs)
+{
+	int i;
+
+	/* Let pending transmits finish.  */
+	for (i = 0; i < 1000; i++) {
+		unsigned char stat = read_zsreg(uap, R1);
+		if (stat & ALL_SNT)
+			break;
+		udelay(100);
+	}
+
+	ZS_CLEARERR(uap);
+	zssync(uap);
+	ZS_CLEARFIFO(uap);
+	zssync(uap);
+	ZS_CLEARERR(uap);
+
+	/* Disable all interrupts.  */
+	write_zsreg(uap, R1,
+		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
+
+	/* Set parity, sync config, stop bits, and clock divisor.  */
+	write_zsreg(uap, R4, regs[R4]);
+
+	/* Set misc. TX/RX control bits.  */
+	write_zsreg(uap, R10, regs[R10]);
+
+	/* Set TX/RX controls sans the enable bits.  */
+	write_zsreg(uap, R3, regs[R3] & ~RxENABLE);
+	write_zsreg(uap, R5, regs[R5] & ~TxENABLE);
+
+	/* now set R7 "prime" on ESCC */
+	write_zsreg(uap, R15, regs[R15] | EN85C30);
+	write_zsreg(uap, R7, regs[R7P]);
+
+	/* make sure we use R7 "non-prime" on ESCC */
+	write_zsreg(uap, R15, regs[R15] & ~EN85C30);
+
+	/* Synchronous mode config.  */
+	write_zsreg(uap, R6, regs[R6]);
+	write_zsreg(uap, R7, regs[R7]);
+
+	/* Disable baud generator.  */
+	write_zsreg(uap, R14, regs[R14] & ~BRENAB);
+
+	/* Clock mode control.  */
+	write_zsreg(uap, R11, regs[R11]);
+
+	/* Lower and upper byte of baud rate generator divisor.  */
+	write_zsreg(uap, R12, regs[R12]);
+	write_zsreg(uap, R13, regs[R13]);
+	
+	/* Now rewrite R14, with BRENAB (if set).  */
+	write_zsreg(uap, R14, regs[R14]);
+
+	/* Reset external status interrupts.  */
+	write_zsreg(uap, R0, RES_EXT_INT);
+	write_zsreg(uap, R0, RES_EXT_INT);
+
+	/* Rewrite R3/R5, this time without enables masked.  */
+	write_zsreg(uap, R3, regs[R3]);
+	write_zsreg(uap, R5, regs[R5]);
+
+	/* Rewrite R1, this time without IRQ enabled masked.  */
+	write_zsreg(uap, R1, regs[R1]);
+
+	/* Enable interrupts */
+	write_zsreg(uap, R9, regs[R9]);
+}
+
+/* 
+ * We do like sunzilog to avoid disrupting pending Tx
+ * Reprogram the Zilog channel HW registers with the copies found in the
+ * software state struct.  If the transmitter is busy, we defer this update
+ * until the next TX complete interrupt.  Else, we do it right now.
+ *
+ * The UART port lock must be held and local interrupts disabled.
+ */
+static void pmz_maybe_update_regs(struct uart_pmac_port *uap)
+{
+	if (!ZS_REGS_HELD(uap)) {
+		if (ZS_TX_ACTIVE(uap)) {
+			uap->flags |= PMACZILOG_FLAG_REGS_HELD;
+		} else {
+			pmz_debug("pmz: maybe_update_regs: updating\n");
+			pmz_load_zsregs(uap, uap->curregs);
+		}
+	}
+}
+
+static void pmz_interrupt_control(struct uart_pmac_port *uap, int enable)
+{
+	if (enable) {
+		uap->curregs[1] |= INT_ALL_Rx | TxINT_ENAB;
+		if (!ZS_IS_EXTCLK(uap))
+			uap->curregs[1] |= EXT_INT_ENAB;
+	} else {
+		uap->curregs[1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
+	}
+	write_zsreg(uap, R1, uap->curregs[1]);
+}
+
+static bool pmz_receive_chars(struct uart_pmac_port *uap)
+	__must_hold(&uap->port.lock)
+{
+	struct tty_port *port;
+	unsigned char ch, r1, drop, flag;
+	int loops = 0;
+
+	/* Sanity check, make sure the old bug is no longer happening */
+	if (uap->port.state == NULL) {
+		WARN_ON(1);
+		(void)read_zsdata(uap);
+		return false;
+	}
+	port = &uap->port.state->port;
+
+	while (1) {
+		drop = 0;
+
+		r1 = read_zsreg(uap, R1);
+		ch = read_zsdata(uap);
+
+		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+			write_zsreg(uap, R0, ERR_RES);
+			zssync(uap);
+		}
+
+		ch &= uap->parity_mask;
+		if (ch == 0 && uap->flags & PMACZILOG_FLAG_BREAK) {
+			uap->flags &= ~PMACZILOG_FLAG_BREAK;
+		}
+
+#if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_SERIAL_CORE_CONSOLE)
+#ifdef USE_CTRL_O_SYSRQ
+		/* Handle the SysRq ^O Hack */
+		if (ch == '\x0f') {
+			uap->port.sysrq = jiffies + HZ*5;
+			goto next_char;
+		}
+#endif /* USE_CTRL_O_SYSRQ */
+		if (uap->port.sysrq) {
+			int swallow;
+			spin_unlock(&uap->port.lock);
+			swallow = uart_handle_sysrq_char(&uap->port, ch);
+			spin_lock(&uap->port.lock);
+			if (swallow)
+				goto next_char;
+		}
+#endif /* CONFIG_MAGIC_SYSRQ && CONFIG_SERIAL_CORE_CONSOLE */
+
+		/* A real serial line, record the character and status.  */
+		if (drop)
+			goto next_char;
+
+		flag = TTY_NORMAL;
+		uap->port.icount.rx++;
+
+		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) {
+			if (r1 & BRK_ABRT) {
+				pmz_debug("pmz: got break !\n");
+				r1 &= ~(PAR_ERR | CRC_ERR);
+				uap->port.icount.brk++;
+				if (uart_handle_break(&uap->port))
+					goto next_char;
+			}
+			else if (r1 & PAR_ERR)
+				uap->port.icount.parity++;
+			else if (r1 & CRC_ERR)
+				uap->port.icount.frame++;
+			if (r1 & Rx_OVR)
+				uap->port.icount.overrun++;
+			r1 &= uap->port.read_status_mask;
+			if (r1 & BRK_ABRT)
+				flag = TTY_BREAK;
+			else if (r1 & PAR_ERR)
+				flag = TTY_PARITY;
+			else if (r1 & CRC_ERR)
+				flag = TTY_FRAME;
+		}
+
+		if (uap->port.ignore_status_mask == 0xff ||
+		    (r1 & uap->port.ignore_status_mask) == 0) {
+			tty_insert_flip_char(port, ch, flag);
+		}
+		if (r1 & Rx_OVR)
+			tty_insert_flip_char(port, 0, TTY_OVERRUN);
+	next_char:
+		/* We can get stuck in an infinite loop getting char 0 when the
+		 * line is in a wrong HW state, we break that here.
+		 * When that happens, I disable the receive side of the driver.
+		 * Note that what I've been experiencing is a real irq loop where
+		 * I'm getting flooded regardless of the actual port speed.
+		 * Something strange is going on with the HW
+		 */
+		if ((++loops) > 1000)
+			goto flood;
+		ch = read_zsreg(uap, R0);
+		if (!(ch & Rx_CH_AV))
+			break;
+	}
+
+	return true;
+ flood:
+	pmz_interrupt_control(uap, 0);
+	pmz_error("pmz: rx irq flood !\n");
+	return true;
+}
+
+static void pmz_status_handle(struct uart_pmac_port *uap)
+{
+	unsigned char status;
+
+	status = read_zsreg(uap, R0);
+	write_zsreg(uap, R0, RES_EXT_INT);
+	zssync(uap);
+
+	if (ZS_IS_OPEN(uap) && ZS_WANTS_MODEM_STATUS(uap)) {
+		if (status & SYNC_HUNT)
+			uap->port.icount.dsr++;
+
+		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
+		 * But it does not tell us which bit has changed, we have to keep
+		 * track of this ourselves.
+		 * The CTS input is inverted for some reason.  -- paulus
+		 */
+		if ((status ^ uap->prev_status) & DCD)
+			uart_handle_dcd_change(&uap->port,
+					       (status & DCD));
+		if ((status ^ uap->prev_status) & CTS)
+			uart_handle_cts_change(&uap->port,
+					       !(status & CTS));
+
+		wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
+	}
+
+	if (status & BRK_ABRT)
+		uap->flags |= PMACZILOG_FLAG_BREAK;
+
+	uap->prev_status = status;
+}
+
+static void pmz_transmit_chars(struct uart_pmac_port *uap)
+{
+	struct circ_buf *xmit;
+
+	if (ZS_IS_CONS(uap)) {
+		unsigned char status = read_zsreg(uap, R0);
+
+		/* TX still busy?  Just wait for the next TX done interrupt.
+		 *
+		 * It can occur because of how we do serial console writes.  It would
+		 * be nice to transmit console writes just like we normally would for
+		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
+		 * easy because console writes cannot sleep.  One solution might be
+		 * to poll on enough port->xmit space becoming free.  -DaveM
+		 */
+		if (!(status & Tx_BUF_EMP))
+			return;
+	}
+
+	uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
+
+	if (ZS_REGS_HELD(uap)) {
+		pmz_load_zsregs(uap, uap->curregs);
+		uap->flags &= ~PMACZILOG_FLAG_REGS_HELD;
+	}
+
+	if (ZS_TX_STOPPED(uap)) {
+		uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
+		goto ack_tx_int;
+	}
+
+	/* Under some circumstances, we see interrupts reported for
+	 * a closed channel. The interrupt mask in R1 is clear, but
+	 * R3 still signals the interrupts and we see them when taking
+	 * an interrupt for the other channel (this could be a qemu
+	 * bug but since the ESCC doc doesn't specify precsiely whether
+	 * R3 interrup status bits are masked by R1 interrupt enable
+	 * bits, better safe than sorry). --BenH.
+	 */
+	if (!ZS_IS_OPEN(uap))
+		goto ack_tx_int;
+
+	if (uap->port.x_char) {
+		uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
+		write_zsdata(uap, uap->port.x_char);
+		zssync(uap);
+		uap->port.icount.tx++;
+		uap->port.x_char = 0;
+		return;
+	}
+
+	if (uap->port.state == NULL)
+		goto ack_tx_int;
+	xmit = &uap->port.state->xmit;
+	if (uart_circ_empty(xmit)) {
+		uart_write_wakeup(&uap->port);
+		goto ack_tx_int;
+	}
+	if (uart_tx_stopped(&uap->port))
+		goto ack_tx_int;
+
+	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
+	write_zsdata(uap, xmit->buf[xmit->tail]);
+	zssync(uap);
+
+	uart_xmit_advance(&uap->port, 1);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&uap->port);
+
+	return;
+
+ack_tx_int:
+	write_zsreg(uap, R0, RES_Tx_P);
+	zssync(uap);
+}
+
+/* Hrm... we register that twice, fixme later.... */
+static irqreturn_t pmz_interrupt(int irq, void *dev_id)
+{
+	struct uart_pmac_port *uap = dev_id;
+	struct uart_pmac_port *uap_a;
+	struct uart_pmac_port *uap_b;
+	int rc = IRQ_NONE;
+	bool push;
+	u8 r3;
+
+	uap_a = pmz_get_port_A(uap);
+	uap_b = uap_a->mate;
+
+	spin_lock(&uap_a->port.lock);
+	r3 = read_zsreg(uap_a, R3);
+
+	/* Channel A */
+	push = false;
+	if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
+		if (!ZS_IS_OPEN(uap_a)) {
+			pmz_debug("ChanA interrupt while not open !\n");
+			goto skip_a;
+		}
+		write_zsreg(uap_a, R0, RES_H_IUS);
+		zssync(uap_a);		
+		if (r3 & CHAEXT)
+			pmz_status_handle(uap_a);
+		if (r3 & CHARxIP)
+			push = pmz_receive_chars(uap_a);
+		if (r3 & CHATxIP)
+			pmz_transmit_chars(uap_a);
+		rc = IRQ_HANDLED;
+	}
+ skip_a:
+	spin_unlock(&uap_a->port.lock);
+	if (push)
+		tty_flip_buffer_push(&uap->port.state->port);
+
+	if (!uap_b)
+		goto out;
+
+	spin_lock(&uap_b->port.lock);
+	push = false;
+	if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
+		if (!ZS_IS_OPEN(uap_b)) {
+			pmz_debug("ChanB interrupt while not open !\n");
+			goto skip_b;
+		}
+		write_zsreg(uap_b, R0, RES_H_IUS);
+		zssync(uap_b);
+		if (r3 & CHBEXT)
+			pmz_status_handle(uap_b);
+		if (r3 & CHBRxIP)
+			push = pmz_receive_chars(uap_b);
+		if (r3 & CHBTxIP)
+			pmz_transmit_chars(uap_b);
+		rc = IRQ_HANDLED;
+	}
+ skip_b:
+	spin_unlock(&uap_b->port.lock);
+	if (push)
+		tty_flip_buffer_push(&uap->port.state->port);
+
+ out:
+	return rc;
+}
+
+/*
+ * Peek the status register, lock not held by caller
+ */
+static inline u8 pmz_peek_status(struct uart_pmac_port *uap)
+{
+	unsigned long flags;
+	u8 status;
+	
+	spin_lock_irqsave(&uap->port.lock, flags);
+	status = read_zsreg(uap, R0);
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+
+	return status;
+}
+
+/* 
+ * Check if transmitter is empty
+ * The port lock is not held.
+ */
+static unsigned int pmz_tx_empty(struct uart_port *port)
+{
+	unsigned char status;
+
+	status = pmz_peek_status(to_pmz(port));
+	if (status & Tx_BUF_EMP)
+		return TIOCSER_TEMT;
+	return 0;
+}
+
+/* 
+ * Set Modem Control (RTS & DTR) bits
+ * The port lock is held and interrupts are disabled.
+ * Note: Shall we really filter out RTS on external ports or
+ * should that be dealt at higher level only ?
+ */
+static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned char set_bits, clear_bits;
+
+        /* Do nothing for irda for now... */
+	if (ZS_IS_IRDA(uap))
+		return;
+	/* We get called during boot with a port not up yet */
+	if (!(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)))
+		return;
+
+	set_bits = clear_bits = 0;
+
+	if (ZS_IS_INTMODEM(uap)) {
+		if (mctrl & TIOCM_RTS)
+			set_bits |= RTS;
+		else
+			clear_bits |= RTS;
+	}
+	if (mctrl & TIOCM_DTR)
+		set_bits |= DTR;
+	else
+		clear_bits |= DTR;
+
+	/* NOTE: Not subject to 'transmitter active' rule.  */ 
+	uap->curregs[R5] |= set_bits;
+	uap->curregs[R5] &= ~clear_bits;
+
+	write_zsreg(uap, R5, uap->curregs[R5]);
+	pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n",
+		  set_bits, clear_bits, uap->curregs[R5]);
+	zssync(uap);
+}
+
+/* 
+ * Get Modem Control bits (only the input ones, the core will
+ * or that with a cached value of the control ones)
+ * The port lock is held and interrupts are disabled.
+ */
+static unsigned int pmz_get_mctrl(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned char status;
+	unsigned int ret;
+
+	status = read_zsreg(uap, R0);
+
+	ret = 0;
+	if (status & DCD)
+		ret |= TIOCM_CAR;
+	if (status & SYNC_HUNT)
+		ret |= TIOCM_DSR;
+	if (!(status & CTS))
+		ret |= TIOCM_CTS;
+
+	return ret;
+}
+
+/* 
+ * Stop TX side. Dealt like sunzilog at next Tx interrupt,
+ * though for DMA, we will have to do a bit more.
+ * The port lock is held and interrupts are disabled.
+ */
+static void pmz_stop_tx(struct uart_port *port)
+{
+	to_pmz(port)->flags |= PMACZILOG_FLAG_TX_STOPPED;
+}
+
+/* 
+ * Kick the Tx side.
+ * The port lock is held and interrupts are disabled.
+ */
+static void pmz_start_tx(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned char status;
+
+	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
+	uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
+
+	status = read_zsreg(uap, R0);
+
+	/* TX busy?  Just wait for the TX done interrupt.  */
+	if (!(status & Tx_BUF_EMP))
+		return;
+
+	/* Send the first character to jump-start the TX done
+	 * IRQ sending engine.
+	 */
+	if (port->x_char) {
+		write_zsdata(uap, port->x_char);
+		zssync(uap);
+		port->icount.tx++;
+		port->x_char = 0;
+	} else {
+		struct circ_buf *xmit = &port->state->xmit;
+
+		if (uart_circ_empty(xmit))
+			return;
+		write_zsdata(uap, xmit->buf[xmit->tail]);
+		zssync(uap);
+		uart_xmit_advance(port, 1);
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&uap->port);
+	}
+}
+
+/* 
+ * Stop Rx side, basically disable emitting of
+ * Rx interrupts on the port. We don't disable the rx
+ * side of the chip proper though
+ * The port lock is held.
+ */
+static void pmz_stop_rx(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+
+	/* Disable all RX interrupts.  */
+	uap->curregs[R1] &= ~RxINT_MASK;
+	pmz_maybe_update_regs(uap);
+}
+
+/* 
+ * Enable modem status change interrupts
+ * The port lock is held.
+ */
+static void pmz_enable_ms(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned char new_reg;
+
+	if (ZS_IS_IRDA(uap))
+		return;
+	new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
+	if (new_reg != uap->curregs[R15]) {
+		uap->curregs[R15] = new_reg;
+
+		/* NOTE: Not subject to 'transmitter active' rule. */
+		write_zsreg(uap, R15, uap->curregs[R15]);
+	}
+}
+
+/* 
+ * Control break state emission
+ * The port lock is not held.
+ */
+static void pmz_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned char set_bits, clear_bits, new_reg;
+	unsigned long flags;
+
+	set_bits = clear_bits = 0;
+
+	if (break_state)
+		set_bits |= SND_BRK;
+	else
+		clear_bits |= SND_BRK;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits;
+	if (new_reg != uap->curregs[R5]) {
+		uap->curregs[R5] = new_reg;
+		write_zsreg(uap, R5, uap->curregs[R5]);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#ifdef CONFIG_PPC_PMAC
+
+/*
+ * Turn power on or off to the SCC and associated stuff
+ * (port drivers, modem, IR port, etc.)
+ * Returns the number of milliseconds we should wait before
+ * trying to use the port.
+ */
+static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
+{
+	int delay = 0;
+	int rc;
+
+	if (state) {
+		rc = pmac_call_feature(
+			PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 1);
+		pmz_debug("port power on result: %d\n", rc);
+		if (ZS_IS_INTMODEM(uap)) {
+			rc = pmac_call_feature(
+				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 1);
+			delay = 2500;	/* wait for 2.5s before using */
+			pmz_debug("modem power result: %d\n", rc);
+		}
+	} else {
+		/* TODO: Make that depend on a timer, don't power down
+		 * immediately
+		 */
+		if (ZS_IS_INTMODEM(uap)) {
+			rc = pmac_call_feature(
+				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 0);
+			pmz_debug("port power off result: %d\n", rc);
+		}
+		pmac_call_feature(PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 0);
+	}
+	return delay;
+}
+
+#else
+
+static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
+{
+	return 0;
+}
+
+#endif /* !CONFIG_PPC_PMAC */
+
+/*
+ * FixZeroBug....Works around a bug in the SCC receiving channel.
+ * Inspired from Darwin code, 15 Sept. 2000  -DanM
+ *
+ * The following sequence prevents a problem that is seen with O'Hare ASICs
+ * (most versions -- also with some Heathrow and Hydra ASICs) where a zero
+ * at the input to the receiver becomes 'stuck' and locks up the receiver.
+ * This problem can occur as a result of a zero bit at the receiver input
+ * coincident with any of the following events:
+ *
+ *	The SCC is initialized (hardware or software).
+ *	A framing error is detected.
+ *	The clocking option changes from synchronous or X1 asynchronous
+ *		clocking to X16, X32, or X64 asynchronous clocking.
+ *	The decoding mode is changed among NRZ, NRZI, FM0, or FM1.
+ *
+ * This workaround attempts to recover from the lockup condition by placing
+ * the SCC in synchronous loopback mode with a fast clock before programming
+ * any of the asynchronous modes.
+ */
+static void pmz_fix_zero_bug_scc(struct uart_pmac_port *uap)
+{
+	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
+	zssync(uap);
+	udelay(10);
+	write_zsreg(uap, 9, (ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB) | NV);
+	zssync(uap);
+
+	write_zsreg(uap, 4, X1CLK | MONSYNC);
+	write_zsreg(uap, 3, Rx8);
+	write_zsreg(uap, 5, Tx8 | RTS);
+	write_zsreg(uap, 9, NV);	/* Didn't we already do this? */
+	write_zsreg(uap, 11, RCBR | TCBR);
+	write_zsreg(uap, 12, 0);
+	write_zsreg(uap, 13, 0);
+	write_zsreg(uap, 14, (LOOPBAK | BRSRC));
+	write_zsreg(uap, 14, (LOOPBAK | BRSRC | BRENAB));
+	write_zsreg(uap, 3, Rx8 | RxENABLE);
+	write_zsreg(uap, 0, RES_EXT_INT);
+	write_zsreg(uap, 0, RES_EXT_INT);
+	write_zsreg(uap, 0, RES_EXT_INT);	/* to kill some time */
+
+	/* The channel should be OK now, but it is probably receiving
+	 * loopback garbage.
+	 * Switch to asynchronous mode, disable the receiver,
+	 * and discard everything in the receive buffer.
+	 */
+	write_zsreg(uap, 9, NV);
+	write_zsreg(uap, 4, X16CLK | SB_MASK);
+	write_zsreg(uap, 3, Rx8);
+
+	while (read_zsreg(uap, 0) & Rx_CH_AV) {
+		(void)read_zsreg(uap, 8);
+		write_zsreg(uap, 0, RES_EXT_INT);
+		write_zsreg(uap, 0, ERR_RES);
+	}
+}
+
+/*
+ * Real startup routine, powers up the hardware and sets up
+ * the SCC. Returns a delay in ms where you need to wait before
+ * actually using the port, this is typically the internal modem
+ * powerup delay. This routine expect the lock to be taken.
+ */
+static int __pmz_startup(struct uart_pmac_port *uap)
+{
+	int pwr_delay = 0;
+
+	memset(&uap->curregs, 0, sizeof(uap->curregs));
+
+	/* Power up the SCC & underlying hardware (modem/irda) */
+	pwr_delay = pmz_set_scc_power(uap, 1);
+
+	/* Nice buggy HW ... */
+	pmz_fix_zero_bug_scc(uap);
+
+	/* Reset the channel */
+	uap->curregs[R9] = 0;
+	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
+	zssync(uap);
+	udelay(10);
+	write_zsreg(uap, 9, 0);
+	zssync(uap);
+
+	/* Clear the interrupt registers */
+	write_zsreg(uap, R1, 0);
+	write_zsreg(uap, R0, ERR_RES);
+	write_zsreg(uap, R0, ERR_RES);
+	write_zsreg(uap, R0, RES_H_IUS);
+	write_zsreg(uap, R0, RES_H_IUS);
+
+	/* Setup some valid baud rate */
+	uap->curregs[R4] = X16CLK | SB1;
+	uap->curregs[R3] = Rx8;
+	uap->curregs[R5] = Tx8 | RTS;
+	if (!ZS_IS_IRDA(uap))
+		uap->curregs[R5] |= DTR;
+	uap->curregs[R12] = 0;
+	uap->curregs[R13] = 0;
+	uap->curregs[R14] = BRENAB;
+
+	/* Clear handshaking, enable BREAK interrupts */
+	uap->curregs[R15] = BRKIE;
+
+	/* Master interrupt enable */
+	uap->curregs[R9] |= NV | MIE;
+
+	pmz_load_zsregs(uap, uap->curregs);
+
+	/* Enable receiver and transmitter.  */
+	write_zsreg(uap, R3, uap->curregs[R3] |= RxENABLE);
+	write_zsreg(uap, R5, uap->curregs[R5] |= TxENABLE);
+
+	/* Remember status for DCD/CTS changes */
+	uap->prev_status = read_zsreg(uap, R0);
+
+	return pwr_delay;
+}
+
+static void pmz_irda_reset(struct uart_pmac_port *uap)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+	uap->curregs[R5] |= DTR;
+	write_zsreg(uap, R5, uap->curregs[R5]);
+	zssync(uap);
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+	msleep(110);
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+	uap->curregs[R5] &= ~DTR;
+	write_zsreg(uap, R5, uap->curregs[R5]);
+	zssync(uap);
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+	msleep(10);
+}
+
+/*
+ * This is the "normal" startup routine, using the above one
+ * wrapped with the lock and doing a schedule delay
+ */
+static int pmz_startup(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned long flags;
+	int pwr_delay = 0;
+
+	uap->flags |= PMACZILOG_FLAG_IS_OPEN;
+
+	/* A console is never powered down. Else, power up and
+	 * initialize the chip
+	 */
+	if (!ZS_IS_CONS(uap)) {
+		spin_lock_irqsave(&port->lock, flags);
+		pwr_delay = __pmz_startup(uap);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}	
+	sprintf(uap->irq_name, PMACZILOG_NAME"%d", uap->port.line);
+	if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED,
+			uap->irq_name, uap)) {
+		pmz_error("Unable to register zs interrupt handler.\n");
+		pmz_set_scc_power(uap, 0);
+		return -ENXIO;
+	}
+
+	/* Right now, we deal with delay by blocking here, I'll be
+	 * smarter later on
+	 */
+	if (pwr_delay != 0) {
+		pmz_debug("pmz: delaying %d ms\n", pwr_delay);
+		msleep(pwr_delay);
+	}
+
+	/* IrDA reset is done now */
+	if (ZS_IS_IRDA(uap))
+		pmz_irda_reset(uap);
+
+	/* Enable interrupt requests for the channel */
+	spin_lock_irqsave(&port->lock, flags);
+	pmz_interrupt_control(uap, 1);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void pmz_shutdown(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable interrupt requests for the channel */
+	pmz_interrupt_control(uap, 0);
+
+	if (!ZS_IS_CONS(uap)) {
+		/* Disable receiver and transmitter */
+		uap->curregs[R3] &= ~RxENABLE;
+		uap->curregs[R5] &= ~TxENABLE;
+
+		/* Disable break assertion */
+		uap->curregs[R5] &= ~SND_BRK;
+		pmz_maybe_update_regs(uap);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Release interrupt handler */
+	free_irq(uap->port.irq, uap);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uap->flags &= ~PMACZILOG_FLAG_IS_OPEN;
+
+	if (!ZS_IS_CONS(uap))
+		pmz_set_scc_power(uap, 0);	/* Shut the chip down */
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Shared by TTY driver and serial console setup.  The port lock is held
+ * and local interrupts are disabled.
+ */
+static void pmz_convert_to_zs(struct uart_pmac_port *uap, unsigned int cflag,
+			      unsigned int iflag, unsigned long baud)
+{
+	int brg;
+
+	/* Switch to external clocking for IrDA high clock rates. That
+	 * code could be re-used for Midi interfaces with different
+	 * multipliers
+	 */
+	if (baud >= 115200 && ZS_IS_IRDA(uap)) {
+		uap->curregs[R4] = X1CLK;
+		uap->curregs[R11] = RCTRxCP | TCTRxCP;
+		uap->curregs[R14] = 0; /* BRG off */
+		uap->curregs[R12] = 0;
+		uap->curregs[R13] = 0;
+		uap->flags |= PMACZILOG_FLAG_IS_EXTCLK;
+	} else {
+		switch (baud) {
+		case ZS_CLOCK/16:	/* 230400 */
+			uap->curregs[R4] = X16CLK;
+			uap->curregs[R11] = 0;
+			uap->curregs[R14] = 0;
+			break;
+		case ZS_CLOCK/32:	/* 115200 */
+			uap->curregs[R4] = X32CLK;
+			uap->curregs[R11] = 0;
+			uap->curregs[R14] = 0;
+			break;
+		default:
+			uap->curregs[R4] = X16CLK;
+			uap->curregs[R11] = TCBR | RCBR;
+			brg = BPS_TO_BRG(baud, ZS_CLOCK / 16);
+			uap->curregs[R12] = (brg & 255);
+			uap->curregs[R13] = ((brg >> 8) & 255);
+			uap->curregs[R14] = BRENAB;
+		}
+		uap->flags &= ~PMACZILOG_FLAG_IS_EXTCLK;
+	}
+
+	/* Character size, stop bits, and parity. */
+	uap->curregs[3] &= ~RxN_MASK;
+	uap->curregs[5] &= ~TxN_MASK;
+
+	switch (cflag & CSIZE) {
+	case CS5:
+		uap->curregs[3] |= Rx5;
+		uap->curregs[5] |= Tx5;
+		uap->parity_mask = 0x1f;
+		break;
+	case CS6:
+		uap->curregs[3] |= Rx6;
+		uap->curregs[5] |= Tx6;
+		uap->parity_mask = 0x3f;
+		break;
+	case CS7:
+		uap->curregs[3] |= Rx7;
+		uap->curregs[5] |= Tx7;
+		uap->parity_mask = 0x7f;
+		break;
+	case CS8:
+	default:
+		uap->curregs[3] |= Rx8;
+		uap->curregs[5] |= Tx8;
+		uap->parity_mask = 0xff;
+		break;
+	}
+	uap->curregs[4] &= ~(SB_MASK);
+	if (cflag & CSTOPB)
+		uap->curregs[4] |= SB2;
+	else
+		uap->curregs[4] |= SB1;
+	if (cflag & PARENB)
+		uap->curregs[4] |= PAR_ENAB;
+	else
+		uap->curregs[4] &= ~PAR_ENAB;
+	if (!(cflag & PARODD))
+		uap->curregs[4] |= PAR_EVEN;
+	else
+		uap->curregs[4] &= ~PAR_EVEN;
+
+	uap->port.read_status_mask = Rx_OVR;
+	if (iflag & INPCK)
+		uap->port.read_status_mask |= CRC_ERR | PAR_ERR;
+	if (iflag & (IGNBRK | BRKINT | PARMRK))
+		uap->port.read_status_mask |= BRK_ABRT;
+
+	uap->port.ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		uap->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
+	if (iflag & IGNBRK) {
+		uap->port.ignore_status_mask |= BRK_ABRT;
+		if (iflag & IGNPAR)
+			uap->port.ignore_status_mask |= Rx_OVR;
+	}
+
+	if ((cflag & CREAD) == 0)
+		uap->port.ignore_status_mask = 0xff;
+}
+
+
+/*
+ * Set the irda codec on the imac to the specified baud rate.
+ */
+static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
+{
+	u8 cmdbyte;
+	int t, version;
+
+	switch (*baud) {
+	/* SIR modes */
+	case 2400:
+		cmdbyte = 0x53;
+		break;
+	case 4800:
+		cmdbyte = 0x52;
+		break;
+	case 9600:
+		cmdbyte = 0x51;
+		break;
+	case 19200:
+		cmdbyte = 0x50;
+		break;
+	case 38400:
+		cmdbyte = 0x4f;
+		break;
+	case 57600:
+		cmdbyte = 0x4e;
+		break;
+	case 115200:
+		cmdbyte = 0x4d;
+		break;
+	/* The FIR modes aren't really supported at this point, how
+	 * do we select the speed ? via the FCR on KeyLargo ?
+	 */
+	case 1152000:
+		cmdbyte = 0;
+		break;
+	case 4000000:
+		cmdbyte = 0;
+		break;
+	default: /* 9600 */
+		cmdbyte = 0x51;
+		*baud = 9600;
+		break;
+	}
+
+	/* Wait for transmitter to drain */
+	t = 10000;
+	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0
+	       || (read_zsreg(uap, R1) & ALL_SNT) == 0) {
+		if (--t <= 0) {
+			pmz_error("transmitter didn't drain\n");
+			return;
+		}
+		udelay(10);
+	}
+
+	/* Drain the receiver too */
+	t = 100;
+	(void)read_zsdata(uap);
+	(void)read_zsdata(uap);
+	(void)read_zsdata(uap);
+	mdelay(10);
+	while (read_zsreg(uap, R0) & Rx_CH_AV) {
+		read_zsdata(uap);
+		mdelay(10);
+		if (--t <= 0) {
+			pmz_error("receiver didn't drain\n");
+			return;
+		}
+	}
+
+	/* Switch to command mode */
+	uap->curregs[R5] |= DTR;
+	write_zsreg(uap, R5, uap->curregs[R5]);
+	zssync(uap);
+	mdelay(1);
+
+	/* Switch SCC to 19200 */
+	pmz_convert_to_zs(uap, CS8, 0, 19200);		
+	pmz_load_zsregs(uap, uap->curregs);
+	mdelay(1);
+
+	/* Write get_version command byte */
+	write_zsdata(uap, 1);
+	t = 5000;
+	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
+		if (--t <= 0) {
+			pmz_error("irda_setup timed out on get_version byte\n");
+			goto out;
+		}
+		udelay(10);
+	}
+	version = read_zsdata(uap);
+
+	if (version < 4) {
+		pmz_info("IrDA: dongle version %d not supported\n", version);
+		goto out;
+	}
+
+	/* Send speed mode */
+	write_zsdata(uap, cmdbyte);
+	t = 5000;
+	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
+		if (--t <= 0) {
+			pmz_error("irda_setup timed out on speed mode byte\n");
+			goto out;
+		}
+		udelay(10);
+	}
+	t = read_zsdata(uap);
+	if (t != cmdbyte)
+		pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte);
+
+	pmz_info("IrDA setup for %ld bps, dongle version: %d\n",
+		 *baud, version);
+
+	(void)read_zsdata(uap);
+	(void)read_zsdata(uap);
+	(void)read_zsdata(uap);
+
+ out:
+	/* Switch back to data mode */
+	uap->curregs[R5] &= ~DTR;
+	write_zsreg(uap, R5, uap->curregs[R5]);
+	zssync(uap);
+
+	(void)read_zsdata(uap);
+	(void)read_zsdata(uap);
+	(void)read_zsdata(uap);
+}
+
+
+static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
+			      const struct ktermios *old)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned long baud;
+
+	/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
+	 * on the IR dongle. Note that the IRTTY driver currently doesn't know
+	 * about the FIR mode and high speed modes. So these are unused. For
+	 * implementing proper support for these, we should probably add some
+	 * DMA as well, at least on the Rx side, which isn't a simple thing
+	 * at this point.
+	 */
+	if (ZS_IS_IRDA(uap)) {
+		/* Calc baud rate */
+		baud = uart_get_baud_rate(port, termios, old, 1200, 4000000);
+		pmz_debug("pmz: switch IRDA to %ld bauds\n", baud);
+		/* Cet the irda codec to the right rate */
+		pmz_irda_setup(uap, &baud);
+		/* Set final baud rate */
+		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
+		pmz_load_zsregs(uap, uap->curregs);
+		zssync(uap);
+	} else {
+		baud = uart_get_baud_rate(port, termios, old, 1200, 230400);
+		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
+		/* Make sure modem status interrupts are correctly configured */
+		if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) {
+			uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE;
+			uap->flags |= PMACZILOG_FLAG_MODEM_STATUS;
+		} else {
+			uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE);
+			uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS;
+		}
+
+		/* Load registers to the chip */
+		pmz_maybe_update_regs(uap);
+	}
+	uart_update_timeout(port, termios->c_cflag, baud);
+}
+
+/* The port lock is not held.  */
+static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
+			    const struct ktermios *old)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);	
+
+	/* Disable IRQs on the port */
+	pmz_interrupt_control(uap, 0);
+
+	/* Setup new port configuration */
+	__pmz_set_termios(port, termios, old);
+
+	/* Re-enable IRQs on the port */
+	if (ZS_IS_OPEN(uap))
+		pmz_interrupt_control(uap, 1);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *pmz_type(struct uart_port *port)
+{
+	struct uart_pmac_port *uap = to_pmz(port);
+
+	if (ZS_IS_IRDA(uap))
+		return "Z85c30 ESCC - Infrared port";
+	else if (ZS_IS_INTMODEM(uap))
+		return "Z85c30 ESCC - Internal modem";
+	return "Z85c30 ESCC - Serial port";
+}
+
+/* We do not request/release mappings of the registers here, this
+ * happens at early serial probe time.
+ */
+static void pmz_release_port(struct uart_port *port)
+{
+}
+
+static int pmz_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/* These do not need to do anything interesting either.  */
+static void pmz_config_port(struct uart_port *port, int flags)
+{
+}
+
+/* We do not support letting the user mess with the divisor, IRQ, etc. */
+static int pmz_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static int pmz_poll_get_char(struct uart_port *port)
+{
+	struct uart_pmac_port *uap =
+		container_of(port, struct uart_pmac_port, port);
+	int tries = 2;
+
+	while (tries) {
+		if ((read_zsreg(uap, R0) & Rx_CH_AV) != 0)
+			return read_zsdata(uap);
+		if (tries--)
+			udelay(5);
+	}
+
+	return NO_POLL_CHAR;
+}
+
+static void pmz_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	struct uart_pmac_port *uap =
+		container_of(port, struct uart_pmac_port, port);
+
+	/* Wait for the transmit buffer to empty. */
+	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
+		udelay(5);
+	write_zsdata(uap, c);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops pmz_pops = {
+	.tx_empty	=	pmz_tx_empty,
+	.set_mctrl	=	pmz_set_mctrl,
+	.get_mctrl	=	pmz_get_mctrl,
+	.stop_tx	=	pmz_stop_tx,
+	.start_tx	=	pmz_start_tx,
+	.stop_rx	=	pmz_stop_rx,
+	.enable_ms	=	pmz_enable_ms,
+	.break_ctl	=	pmz_break_ctl,
+	.startup	=	pmz_startup,
+	.shutdown	=	pmz_shutdown,
+	.set_termios	=	pmz_set_termios,
+	.type		=	pmz_type,
+	.release_port	=	pmz_release_port,
+	.request_port	=	pmz_request_port,
+	.config_port	=	pmz_config_port,
+	.verify_port	=	pmz_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	=	pmz_poll_get_char,
+	.poll_put_char	=	pmz_poll_put_char,
+#endif
+};
+
+#ifdef CONFIG_PPC_PMAC
+
+/*
+ * Setup one port structure after probing, HW is down at this point,
+ * Unlike sunzilog, we don't need to pre-init the spinlock as we don't
+ * register our console before uart_add_one_port() is called
+ */
+static int __init pmz_init_port(struct uart_pmac_port *uap)
+{
+	struct device_node *np = uap->node;
+	const char *conn;
+	const struct slot_names_prop {
+		int	count;
+		char	name[1];
+	} *slots;
+	int len;
+	struct resource r_ports;
+
+	/*
+	 * Request & map chip registers
+	 */
+	if (of_address_to_resource(np, 0, &r_ports))
+		return -ENODEV;
+	uap->port.mapbase = r_ports.start;
+	uap->port.membase = ioremap(uap->port.mapbase, 0x1000);
+
+	uap->control_reg = uap->port.membase;
+	uap->data_reg = uap->control_reg + 0x10;
+
+	/*
+	 * Detect port type
+	 */
+	if (of_device_is_compatible(np, "cobalt"))
+		uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
+	conn = of_get_property(np, "AAPL,connector", &len);
+	if (conn && (strcmp(conn, "infrared") == 0))
+		uap->flags |= PMACZILOG_FLAG_IS_IRDA;
+	uap->port_type = PMAC_SCC_ASYNC;
+	/* 1999 Powerbook G3 has slot-names property instead */
+	slots = of_get_property(np, "slot-names", &len);
+	if (slots && slots->count > 0) {
+		if (strcmp(slots->name, "IrDA") == 0)
+			uap->flags |= PMACZILOG_FLAG_IS_IRDA;
+		else if (strcmp(slots->name, "Modem") == 0)
+			uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
+	}
+	if (ZS_IS_IRDA(uap))
+		uap->port_type = PMAC_SCC_IRDA;
+	if (ZS_IS_INTMODEM(uap)) {
+		struct device_node* i2c_modem =
+			of_find_node_by_name(NULL, "i2c-modem");
+		if (i2c_modem) {
+			const char* mid =
+				of_get_property(i2c_modem, "modem-id", NULL);
+			if (mid) switch(*mid) {
+			case 0x04 :
+			case 0x05 :
+			case 0x07 :
+			case 0x08 :
+			case 0x0b :
+			case 0x0c :
+				uap->port_type = PMAC_SCC_I2S1;
+			}
+			printk(KERN_INFO "pmac_zilog: i2c-modem detected, id: %d\n",
+				mid ? (*mid) : 0);
+			of_node_put(i2c_modem);
+		} else {
+			printk(KERN_INFO "pmac_zilog: serial modem detected\n");
+		}
+	}
+
+	/*
+	 * Init remaining bits of "port" structure
+	 */
+	uap->port.iotype = UPIO_MEM;
+	uap->port.irq = irq_of_parse_and_map(np, 0);
+	uap->port.uartclk = ZS_CLOCK;
+	uap->port.fifosize = 1;
+	uap->port.ops = &pmz_pops;
+	uap->port.type = PORT_PMAC_ZILOG;
+	uap->port.flags = 0;
+
+	/*
+	 * Fixup for the port on Gatwick for which the device-tree has
+	 * missing interrupts. Normally, the macio_dev would contain
+	 * fixed up interrupt info, but we use the device-tree directly
+	 * here due to early probing so we need the fixup too.
+	 */
+	if (uap->port.irq == 0 &&
+	    np->parent && np->parent->parent &&
+	    of_device_is_compatible(np->parent->parent, "gatwick")) {
+		/* IRQs on gatwick are offset by 64 */
+		uap->port.irq = irq_create_mapping(NULL, 64 + 15);
+	}
+
+	/* Setup some valid baud rate information in the register
+	 * shadows so we don't write crap there before baud rate is
+	 * first initialized.
+	 */
+	pmz_convert_to_zs(uap, CS8, 0, 9600);
+
+	return 0;
+}
+
+/*
+ * Get rid of a port on module removal
+ */
+static void pmz_dispose_port(struct uart_pmac_port *uap)
+{
+	struct device_node *np;
+
+	np = uap->node;
+	iounmap(uap->control_reg);
+	uap->node = NULL;
+	of_node_put(np);
+	memset(uap, 0, sizeof(struct uart_pmac_port));
+}
+
+/*
+ * Called upon match with an escc node in the device-tree.
+ */
+static int pmz_attach(struct macio_dev *mdev, const struct of_device_id *match)
+{
+	struct uart_pmac_port *uap;
+	int i;
+	
+	/* Iterate the pmz_ports array to find a matching entry
+	 */
+	for (i = 0; i < MAX_ZS_PORTS; i++)
+		if (pmz_ports[i].node == mdev->ofdev.dev.of_node)
+			break;
+	if (i >= MAX_ZS_PORTS)
+		return -ENODEV;
+
+
+	uap = &pmz_ports[i];
+	uap->dev = mdev;
+	uap->port.dev = &mdev->ofdev.dev;
+	dev_set_drvdata(&mdev->ofdev.dev, uap);
+
+	/* We still activate the port even when failing to request resources
+	 * to work around bugs in ancient Apple device-trees
+	 */
+	if (macio_request_resources(uap->dev, "pmac_zilog"))
+		printk(KERN_WARNING "%pOFn: Failed to request resource"
+		       ", port still active\n",
+		       uap->node);
+	else
+		uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED;
+
+	return uart_add_one_port(&pmz_uart_reg, &uap->port);
+}
+
+/*
+ * That one should not be called, macio isn't really a hotswap device,
+ * we don't expect one of those serial ports to go away...
+ */
+static int pmz_detach(struct macio_dev *mdev)
+{
+	struct uart_pmac_port	*uap = dev_get_drvdata(&mdev->ofdev.dev);
+	
+	if (!uap)
+		return -ENODEV;
+
+	uart_remove_one_port(&pmz_uart_reg, &uap->port);
+
+	if (uap->flags & PMACZILOG_FLAG_RSRC_REQUESTED) {
+		macio_release_resources(uap->dev);
+		uap->flags &= ~PMACZILOG_FLAG_RSRC_REQUESTED;
+	}
+	dev_set_drvdata(&mdev->ofdev.dev, NULL);
+	uap->dev = NULL;
+	uap->port.dev = NULL;
+	
+	return 0;
+}
+
+
+static int pmz_suspend(struct macio_dev *mdev, pm_message_t pm_state)
+{
+	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
+
+	if (uap == NULL) {
+		printk("HRM... pmz_suspend with NULL uap\n");
+		return 0;
+	}
+
+	uart_suspend_port(&pmz_uart_reg, &uap->port);
+
+	return 0;
+}
+
+
+static int pmz_resume(struct macio_dev *mdev)
+{
+	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
+
+	if (uap == NULL)
+		return 0;
+
+	uart_resume_port(&pmz_uart_reg, &uap->port);
+
+	return 0;
+}
+
+/*
+ * Probe all ports in the system and build the ports array, we register
+ * with the serial layer later, so we get a proper struct device which
+ * allows the tty to attach properly. This is later than it used to be
+ * but the tty layer really wants it that way.
+ */
+static int __init pmz_probe(void)
+{
+	struct device_node	*node_p, *node_a, *node_b, *np;
+	int			count = 0;
+	int			rc;
+
+	/*
+	 * Find all escc chips in the system
+	 */
+	for_each_node_by_name(node_p, "escc") {
+		/*
+		 * First get channel A/B node pointers
+		 * 
+		 * TODO: Add routines with proper locking to do that...
+		 */
+		node_a = node_b = NULL;
+		for_each_child_of_node(node_p, np) {
+			if (of_node_name_prefix(np, "ch-a"))
+				node_a = of_node_get(np);
+			else if (of_node_name_prefix(np, "ch-b"))
+				node_b = of_node_get(np);
+		}
+		if (!node_a && !node_b) {
+			of_node_put(node_a);
+			of_node_put(node_b);
+			printk(KERN_ERR "pmac_zilog: missing node %c for escc %pOF\n",
+				(!node_a) ? 'a' : 'b', node_p);
+			continue;
+		}
+
+		/*
+		 * Fill basic fields in the port structures
+		 */
+		if (node_b != NULL) {
+			pmz_ports[count].mate		= &pmz_ports[count+1];
+			pmz_ports[count+1].mate		= &pmz_ports[count];
+		}
+		pmz_ports[count].flags		= PMACZILOG_FLAG_IS_CHANNEL_A;
+		pmz_ports[count].node		= node_a;
+		pmz_ports[count+1].node		= node_b;
+		pmz_ports[count].port.line	= count;
+		pmz_ports[count+1].port.line	= count+1;
+
+		/*
+		 * Setup the ports for real
+		 */
+		rc = pmz_init_port(&pmz_ports[count]);
+		if (rc == 0 && node_b != NULL)
+			rc = pmz_init_port(&pmz_ports[count+1]);
+		if (rc != 0) {
+			of_node_put(node_a);
+			of_node_put(node_b);
+			memset(&pmz_ports[count], 0, sizeof(struct uart_pmac_port));
+			memset(&pmz_ports[count+1], 0, sizeof(struct uart_pmac_port));
+			continue;
+		}
+		count += 2;
+	}
+	pmz_ports_count = count;
+
+	return 0;
+}
+
+#else
+
+/* On PCI PowerMacs, pmz_probe() does an explicit search of the OpenFirmware
+ * tree to obtain the device_nodes needed to start the console before the
+ * macio driver. On Macs without OpenFirmware, global platform_devices take
+ * the place of those device_nodes.
+ */
+extern struct platform_device scc_a_pdev, scc_b_pdev;
+
+static int __init pmz_init_port(struct uart_pmac_port *uap)
+{
+	struct resource *r_ports;
+	int irq;
+
+	r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
+	if (!r_ports)
+		return -ENODEV;
+
+	irq = platform_get_irq(uap->pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	uap->port.mapbase  = r_ports->start;
+	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
+	uap->port.iotype   = UPIO_MEM;
+	uap->port.irq      = irq;
+	uap->port.uartclk  = ZS_CLOCK;
+	uap->port.fifosize = 1;
+	uap->port.ops      = &pmz_pops;
+	uap->port.type     = PORT_PMAC_ZILOG;
+	uap->port.flags    = 0;
+
+	uap->control_reg   = uap->port.membase;
+	uap->data_reg      = uap->control_reg + 4;
+	uap->port_type     = 0;
+	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_PMACZILOG_CONSOLE);
+
+	pmz_convert_to_zs(uap, CS8, 0, 9600);
+
+	return 0;
+}
+
+static int __init pmz_probe(void)
+{
+	int err;
+
+	pmz_ports_count = 0;
+
+	pmz_ports[0].port.line = 0;
+	pmz_ports[0].flags     = PMACZILOG_FLAG_IS_CHANNEL_A;
+	pmz_ports[0].pdev      = &scc_a_pdev;
+	err = pmz_init_port(&pmz_ports[0]);
+	if (err)
+		return err;
+	pmz_ports_count++;
+
+	pmz_ports[0].mate      = &pmz_ports[1];
+	pmz_ports[1].mate      = &pmz_ports[0];
+	pmz_ports[1].port.line = 1;
+	pmz_ports[1].flags     = 0;
+	pmz_ports[1].pdev      = &scc_b_pdev;
+	err = pmz_init_port(&pmz_ports[1]);
+	if (err)
+		return err;
+	pmz_ports_count++;
+
+	return 0;
+}
+
+static void pmz_dispose_port(struct uart_pmac_port *uap)
+{
+	memset(uap, 0, sizeof(struct uart_pmac_port));
+}
+
+static int __init pmz_attach(struct platform_device *pdev)
+{
+	struct uart_pmac_port *uap;
+	int i;
+
+	/* Iterate the pmz_ports array to find a matching entry */
+	for (i = 0; i < pmz_ports_count; i++)
+		if (pmz_ports[i].pdev == pdev)
+			break;
+	if (i >= pmz_ports_count)
+		return -ENODEV;
+
+	uap = &pmz_ports[i];
+	uap->port.dev = &pdev->dev;
+	platform_set_drvdata(pdev, uap);
+
+	return uart_add_one_port(&pmz_uart_reg, &uap->port);
+}
+
+static int __exit pmz_detach(struct platform_device *pdev)
+{
+	struct uart_pmac_port *uap = platform_get_drvdata(pdev);
+
+	if (!uap)
+		return -ENODEV;
+
+	uart_remove_one_port(&pmz_uart_reg, &uap->port);
+
+	uap->port.dev = NULL;
+
+	return 0;
+}
+
+#endif /* !CONFIG_PPC_PMAC */
+
+#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
+
+static void pmz_console_write(struct console *con, const char *s, unsigned int count);
+static int __init pmz_console_setup(struct console *co, char *options);
+
+static struct console pmz_console = {
+	.name	=	PMACZILOG_NAME,
+	.write	=	pmz_console_write,
+	.device	=	uart_console_device,
+	.setup	=	pmz_console_setup,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data   =	&pmz_uart_reg,
+};
+
+#define PMACZILOG_CONSOLE	&pmz_console
+#else /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
+#define PMACZILOG_CONSOLE	(NULL)
+#endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
+
+/*
+ * Register the driver, console driver and ports with the serial
+ * core
+ */
+static int __init pmz_register(void)
+{
+	pmz_uart_reg.nr = pmz_ports_count;
+	pmz_uart_reg.cons = PMACZILOG_CONSOLE;
+
+	/*
+	 * Register this driver with the serial core
+	 */
+	return uart_register_driver(&pmz_uart_reg);
+}
+
+#ifdef CONFIG_PPC_PMAC
+
+static const struct of_device_id pmz_match[] =
+{
+	{
+	.name		= "ch-a",
+	},
+	{
+	.name		= "ch-b",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE (of, pmz_match);
+
+static struct macio_driver pmz_driver = {
+	.driver = {
+		.name 		= "pmac_zilog",
+		.owner		= THIS_MODULE,
+		.of_match_table	= pmz_match,
+	},
+	.probe		= pmz_attach,
+	.remove		= pmz_detach,
+	.suspend	= pmz_suspend,
+	.resume		= pmz_resume,
+};
+
+#else
+
+static struct platform_driver pmz_driver = {
+	.remove		= __exit_p(pmz_detach),
+	.driver		= {
+		.name		= "scc",
+	},
+};
+
+#endif /* !CONFIG_PPC_PMAC */
+
+static int __init init_pmz(void)
+{
+	int rc, i;
+
+	/* 
+	 * First, we need to do a direct OF-based probe pass. We
+	 * do that because we want serial console up before the
+	 * macio stuffs calls us back, and since that makes it
+	 * easier to pass the proper number of channels to
+	 * uart_register_driver()
+	 */
+	if (pmz_ports_count == 0)
+		pmz_probe();
+
+	/*
+	 * Bail early if no port found
+	 */
+	if (pmz_ports_count == 0)
+		return -ENODEV;
+
+	/*
+	 * Now we register with the serial layer
+	 */
+	rc = pmz_register();
+	if (rc) {
+		printk(KERN_ERR 
+			"pmac_zilog: Error registering serial device, disabling pmac_zilog.\n"
+		 	"pmac_zilog: Did another serial driver already claim the minors?\n"); 
+		/* effectively "pmz_unprobe()" */
+		for (i=0; i < pmz_ports_count; i++)
+			pmz_dispose_port(&pmz_ports[i]);
+		return rc;
+	}
+
+	/*
+	 * Then we register the macio driver itself
+	 */
+#ifdef CONFIG_PPC_PMAC
+	return macio_register_driver(&pmz_driver);
+#else
+	return platform_driver_probe(&pmz_driver, pmz_attach);
+#endif
+}
+
+static void __exit exit_pmz(void)
+{
+	int i;
+
+#ifdef CONFIG_PPC_PMAC
+	/* Get rid of macio-driver (detach from macio) */
+	macio_unregister_driver(&pmz_driver);
+#else
+	platform_driver_unregister(&pmz_driver);
+#endif
+
+	for (i = 0; i < pmz_ports_count; i++) {
+		struct uart_pmac_port *uport = &pmz_ports[i];
+#ifdef CONFIG_PPC_PMAC
+		if (uport->node != NULL)
+			pmz_dispose_port(uport);
+#else
+		if (uport->pdev != NULL)
+			pmz_dispose_port(uport);
+#endif
+	}
+	/* Unregister UART driver */
+	uart_unregister_driver(&pmz_uart_reg);
+}
+
+#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
+
+static void pmz_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_pmac_port *uap =
+		container_of(port, struct uart_pmac_port, port);
+
+	/* Wait for the transmit buffer to empty. */
+	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
+		udelay(5);
+	write_zsdata(uap, ch);
+}
+
+/*
+ * Print a string to the serial port trying not to disturb
+ * any possible real use of the port...
+ */
+static void pmz_console_write(struct console *con, const char *s, unsigned int count)
+{
+	struct uart_pmac_port *uap = &pmz_ports[con->index];
+	unsigned long flags;
+
+	spin_lock_irqsave(&uap->port.lock, flags);
+
+	/* Turn of interrupts and enable the transmitter. */
+	write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
+	write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR);
+
+	uart_console_write(&uap->port, s, count, pmz_console_putchar);
+
+	/* Restore the values in the registers. */
+	write_zsreg(uap, R1, uap->curregs[1]);
+	/* Don't disable the transmitter. */
+
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+/*
+ * Setup the serial console
+ */
+static int __init pmz_console_setup(struct console *co, char *options)
+{
+	struct uart_pmac_port *uap;
+	struct uart_port *port;
+	int baud = 38400;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	unsigned long pwr_delay;
+
+	/*
+	 * XServe's default to 57600 bps
+	 */
+	if (of_machine_is_compatible("RackMac1,1")
+	    || of_machine_is_compatible("RackMac1,2")
+	    || of_machine_is_compatible("MacRISC4"))
+		baud = 57600;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= pmz_ports_count)
+		co->index = 0;
+	uap = &pmz_ports[co->index];
+#ifdef CONFIG_PPC_PMAC
+	if (uap->node == NULL)
+		return -ENODEV;
+#else
+	if (uap->pdev == NULL)
+		return -ENODEV;
+#endif
+	port = &uap->port;
+
+	/*
+	 * Mark port as beeing a console
+	 */
+	uap->flags |= PMACZILOG_FLAG_IS_CONS;
+
+	/*
+	 * Temporary fix for uart layer who didn't setup the spinlock yet
+	 */
+	spin_lock_init(&port->lock);
+
+	/*
+	 * Enable the hardware
+	 */
+	pwr_delay = __pmz_startup(uap);
+	if (pwr_delay)
+		mdelay(pwr_delay);
+	
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static int __init pmz_console_init(void)
+{
+	/* Probe ports */
+	pmz_probe();
+
+	if (pmz_ports_count == 0)
+		return -ENODEV;
+
+	/* TODO: Autoprobe console based on OF */
+	/* pmz_console.index = i; */
+	register_console(&pmz_console);
+
+	return 0;
+
+}
+console_initcall(pmz_console_init);
+#endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
+
+module_init(init_pmz);
+module_exit(exit_pmz);
diff --git a/drivers/tty/serial/pmac_zilog.h b/drivers/tty/serial/pmac_zilog.h
new file mode 100644
index 000000000..837b97ca0
--- /dev/null
+++ b/drivers/tty/serial/pmac_zilog.h
@@ -0,0 +1,373 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PMAC_ZILOG_H__
+#define __PMAC_ZILOG_H__
+
+/*
+ * At most 2 ESCCs with 2 ports each
+ */
+#define MAX_ZS_PORTS	4
+
+/* 
+ * We wrap our port structure around the generic uart_port.
+ */
+#define NUM_ZSREGS    17
+
+struct uart_pmac_port {
+	struct uart_port		port;
+	struct uart_pmac_port		*mate;
+
+#ifdef CONFIG_PPC_PMAC
+	/* macio_dev for the escc holding this port (maybe be null on
+	 * early inited port)
+	 */
+	struct macio_dev		*dev;
+	/* device node to this port, this points to one of 2 childs
+	 * of "escc" node (ie. ch-a or ch-b)
+	 */
+	struct device_node		*node;
+#else
+	struct platform_device		*pdev;
+#endif
+
+	/* Port type as obtained from device tree (IRDA, modem, ...) */
+	int				port_type;
+	u8				curregs[NUM_ZSREGS];
+
+	unsigned int			flags;
+#define PMACZILOG_FLAG_IS_CONS		0x00000001
+#define PMACZILOG_FLAG_IS_KGDB		0x00000002
+#define PMACZILOG_FLAG_MODEM_STATUS	0x00000004
+#define PMACZILOG_FLAG_IS_CHANNEL_A	0x00000008
+#define PMACZILOG_FLAG_REGS_HELD	0x00000010
+#define PMACZILOG_FLAG_TX_STOPPED	0x00000020
+#define PMACZILOG_FLAG_TX_ACTIVE	0x00000040
+#define PMACZILOG_FLAG_IS_IRDA		0x00000100
+#define PMACZILOG_FLAG_IS_INTMODEM	0x00000200
+#define PMACZILOG_FLAG_RSRC_REQUESTED	0x00000800
+#define PMACZILOG_FLAG_IS_OPEN		0x00002000
+#define PMACZILOG_FLAG_IS_EXTCLK	0x00008000
+#define PMACZILOG_FLAG_BREAK		0x00010000
+
+	unsigned char			parity_mask;
+	unsigned char			prev_status;
+
+	volatile u8			__iomem *control_reg;
+	volatile u8			__iomem *data_reg;
+
+	unsigned char			irq_name[8];
+};
+
+#define to_pmz(p) ((struct uart_pmac_port *)(p))
+
+static inline struct uart_pmac_port *pmz_get_port_A(struct uart_pmac_port *uap)
+{
+	if (uap->flags & PMACZILOG_FLAG_IS_CHANNEL_A)
+		return uap;
+	return uap->mate;
+}
+
+/*
+ * Register accessors. Note that we don't need to enforce a recovery
+ * delay on PCI PowerMac hardware, it's dealt in HW by the MacIO chip,
+ * though if we try to use this driver on older machines, we might have
+ * to add it back
+ */
+static inline u8 read_zsreg(struct uart_pmac_port *port, u8 reg)
+{
+	if (reg != 0)
+		writeb(reg, port->control_reg);
+	return readb(port->control_reg);
+}
+
+static inline void write_zsreg(struct uart_pmac_port *port, u8 reg, u8 value)
+{
+	if (reg != 0)
+		writeb(reg, port->control_reg);
+	writeb(value, port->control_reg);
+}
+
+static inline u8 read_zsdata(struct uart_pmac_port *port)
+{
+	return readb(port->data_reg);
+}
+
+static inline void write_zsdata(struct uart_pmac_port *port, u8 data)
+{
+	writeb(data, port->data_reg);
+}
+
+static inline void zssync(struct uart_pmac_port *port)
+{
+	(void)readb(port->control_reg);
+}
+
+/* Conversion routines to/from brg time constants from/to bits
+ * per second.
+ */
+#define BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
+#define BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)
+
+#define ZS_CLOCK         3686400	/* Z8530 RTxC input clock rate */
+
+/* The Zilog register set */
+
+#define	FLAG	0x7e
+
+/* Write Register 0 */
+#define	R0	0		/* Register selects */
+#define	R1	1
+#define	R2	2
+#define	R3	3
+#define	R4	4
+#define	R5	5
+#define	R6	6
+#define	R7	7
+#define	R8	8
+#define	R9	9
+#define	R10	10
+#define	R11	11
+#define	R12	12
+#define	R13	13
+#define	R14	14
+#define	R15	15
+#define	R7P	16
+
+#define	NULLCODE	0	/* Null Code */
+#define	POINT_HIGH	0x8	/* Select upper half of registers */
+#define	RES_EXT_INT	0x10	/* Reset Ext. Status Interrupts */
+#define	SEND_ABORT	0x18	/* HDLC Abort */
+#define	RES_RxINT_FC	0x20	/* Reset RxINT on First Character */
+#define	RES_Tx_P	0x28	/* Reset TxINT Pending */
+#define	ERR_RES		0x30	/* Error Reset */
+#define	RES_H_IUS	0x38	/* Reset highest IUS */
+
+#define	RES_Rx_CRC	0x40	/* Reset Rx CRC Checker */
+#define	RES_Tx_CRC	0x80	/* Reset Tx CRC Checker */
+#define	RES_EOM_L	0xC0	/* Reset EOM latch */
+
+/* Write Register 1 */
+
+#define	EXT_INT_ENAB	0x1	/* Ext Int Enable */
+#define	TxINT_ENAB	0x2	/* Tx Int Enable */
+#define	PAR_SPEC	0x4	/* Parity is special condition */
+
+#define	RxINT_DISAB	0	/* Rx Int Disable */
+#define	RxINT_FCERR	0x8	/* Rx Int on First Character Only or Error */
+#define	INT_ALL_Rx	0x10	/* Int on all Rx Characters or error */
+#define	INT_ERR_Rx	0x18	/* Int on error only */
+#define RxINT_MASK	0x18
+
+#define	WT_RDY_RT	0x20	/* W/Req reflects recv if 1, xmit if 0 */
+#define	WT_FN_RDYFN	0x40	/* W/Req pin is DMA request if 1, wait if 0 */
+#define	WT_RDY_ENAB	0x80	/* Enable W/Req pin */
+
+/* Write Register #2 (Interrupt Vector) */
+
+/* Write Register 3 */
+
+#define	RxENABLE	0x1	/* Rx Enable */
+#define	SYNC_L_INH	0x2	/* Sync Character Load Inhibit */
+#define	ADD_SM		0x4	/* Address Search Mode (SDLC) */
+#define	RxCRC_ENAB	0x8	/* Rx CRC Enable */
+#define	ENT_HM		0x10	/* Enter Hunt Mode */
+#define	AUTO_ENAB	0x20	/* Auto Enables */
+#define	Rx5		0x0	/* Rx 5 Bits/Character */
+#define	Rx7		0x40	/* Rx 7 Bits/Character */
+#define	Rx6		0x80	/* Rx 6 Bits/Character */
+#define	Rx8		0xc0	/* Rx 8 Bits/Character */
+#define RxN_MASK	0xc0
+
+/* Write Register 4 */
+
+#define	PAR_ENAB	0x1	/* Parity Enable */
+#define	PAR_EVEN	0x2	/* Parity Even/Odd* */
+
+#define	SYNC_ENAB	0	/* Sync Modes Enable */
+#define	SB1		0x4	/* 1 stop bit/char */
+#define	SB15		0x8	/* 1.5 stop bits/char */
+#define	SB2		0xc	/* 2 stop bits/char */
+#define SB_MASK		0xc
+
+#define	MONSYNC		0	/* 8 Bit Sync character */
+#define	BISYNC		0x10	/* 16 bit sync character */
+#define	SDLC		0x20	/* SDLC Mode (01111110 Sync Flag) */
+#define	EXTSYNC		0x30	/* External Sync Mode */
+
+#define	X1CLK		0x0	/* x1 clock mode */
+#define	X16CLK		0x40	/* x16 clock mode */
+#define	X32CLK		0x80	/* x32 clock mode */
+#define	X64CLK		0xC0	/* x64 clock mode */
+#define XCLK_MASK	0xC0
+
+/* Write Register 5 */
+
+#define	TxCRC_ENAB	0x1	/* Tx CRC Enable */
+#define	RTS		0x2	/* RTS */
+#define	SDLC_CRC	0x4	/* SDLC/CRC-16 */
+#define	TxENABLE	0x8	/* Tx Enable */
+#define	SND_BRK		0x10	/* Send Break */
+#define	Tx5		0x0	/* Tx 5 bits (or less)/character */
+#define	Tx7		0x20	/* Tx 7 bits/character */
+#define	Tx6		0x40	/* Tx 6 bits/character */
+#define	Tx8		0x60	/* Tx 8 bits/character */
+#define TxN_MASK	0x60
+#define	DTR		0x80	/* DTR */
+
+/* Write Register 6 (Sync bits 0-7/SDLC Address Field) */
+
+/* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
+
+/* Write Register 7' (Some enhanced feature control) */
+#define	ENEXREAD	0x40	/* Enable read of some write registers */
+
+/* Write Register 8 (transmit buffer) */
+
+/* Write Register 9 (Master interrupt control) */
+#define	VIS	1	/* Vector Includes Status */
+#define	NV	2	/* No Vector */
+#define	DLC	4	/* Disable Lower Chain */
+#define	MIE	8	/* Master Interrupt Enable */
+#define	STATHI	0x10	/* Status high */
+#define	NORESET	0	/* No reset on write to R9 */
+#define	CHRB	0x40	/* Reset channel B */
+#define	CHRA	0x80	/* Reset channel A */
+#define	FHWRES	0xc0	/* Force hardware reset */
+
+/* Write Register 10 (misc control bits) */
+#define	BIT6	1	/* 6 bit/8bit sync */
+#define	LOOPMODE 2	/* SDLC Loop mode */
+#define	ABUNDER	4	/* Abort/flag on SDLC xmit underrun */
+#define	MARKIDLE 8	/* Mark/flag on idle */
+#define	GAOP	0x10	/* Go active on poll */
+#define	NRZ	0	/* NRZ mode */
+#define	NRZI	0x20	/* NRZI mode */
+#define	FM1	0x40	/* FM1 (transition = 1) */
+#define	FM0	0x60	/* FM0 (transition = 0) */
+#define	CRCPS	0x80	/* CRC Preset I/O */
+
+/* Write Register 11 (Clock Mode control) */
+#define	TRxCXT	0	/* TRxC = Xtal output */
+#define	TRxCTC	1	/* TRxC = Transmit clock */
+#define	TRxCBR	2	/* TRxC = BR Generator Output */
+#define	TRxCDP	3	/* TRxC = DPLL output */
+#define	TRxCOI	4	/* TRxC O/I */
+#define	TCRTxCP	0	/* Transmit clock = RTxC pin */
+#define	TCTRxCP	8	/* Transmit clock = TRxC pin */
+#define	TCBR	0x10	/* Transmit clock = BR Generator output */
+#define	TCDPLL	0x18	/* Transmit clock = DPLL output */
+#define	RCRTxCP	0	/* Receive clock = RTxC pin */
+#define	RCTRxCP	0x20	/* Receive clock = TRxC pin */
+#define	RCBR	0x40	/* Receive clock = BR Generator output */
+#define	RCDPLL	0x60	/* Receive clock = DPLL output */
+#define	RTxCX	0x80	/* RTxC Xtal/No Xtal */
+
+/* Write Register 12 (lower byte of baud rate generator time constant) */
+
+/* Write Register 13 (upper byte of baud rate generator time constant) */
+
+/* Write Register 14 (Misc control bits) */
+#define	BRENAB	1	/* Baud rate generator enable */
+#define	BRSRC	2	/* Baud rate generator source */
+#define	DTRREQ	4	/* DTR/Request function */
+#define	AUTOECHO 8	/* Auto Echo */
+#define	LOOPBAK	0x10	/* Local loopback */
+#define	SEARCH	0x20	/* Enter search mode */
+#define	RMC	0x40	/* Reset missing clock */
+#define	DISDPLL	0x60	/* Disable DPLL */
+#define	SSBR	0x80	/* Set DPLL source = BR generator */
+#define	SSRTxC	0xa0	/* Set DPLL source = RTxC */
+#define	SFMM	0xc0	/* Set FM mode */
+#define	SNRZI	0xe0	/* Set NRZI mode */
+
+/* Write Register 15 (external/status interrupt control) */
+#define	EN85C30	1	/* Enable some 85c30-enhanced registers */
+#define	ZCIE	2	/* Zero count IE */
+#define	ENSTFIFO 4	/* Enable status FIFO (SDLC) */
+#define	DCDIE	8	/* DCD IE */
+#define	SYNCIE	0x10	/* Sync/hunt IE */
+#define	CTSIE	0x20	/* CTS IE */
+#define	TxUIE	0x40	/* Tx Underrun/EOM IE */
+#define	BRKIE	0x80	/* Break/Abort IE */
+
+
+/* Read Register 0 */
+#define	Rx_CH_AV	0x1	/* Rx Character Available */
+#define	ZCOUNT		0x2	/* Zero count */
+#define	Tx_BUF_EMP	0x4	/* Tx Buffer empty */
+#define	DCD		0x8	/* DCD */
+#define	SYNC_HUNT	0x10	/* Sync/hunt */
+#define	CTS		0x20	/* CTS */
+#define	TxEOM		0x40	/* Tx underrun */
+#define	BRK_ABRT	0x80	/* Break/Abort */
+
+/* Read Register 1 */
+#define	ALL_SNT		0x1	/* All sent */
+/* Residue Data for 8 Rx bits/char programmed */
+#define	RES3		0x8	/* 0/3 */
+#define	RES4		0x4	/* 0/4 */
+#define	RES5		0xc	/* 0/5 */
+#define	RES6		0x2	/* 0/6 */
+#define	RES7		0xa	/* 0/7 */
+#define	RES8		0x6	/* 0/8 */
+#define	RES18		0xe	/* 1/8 */
+#define	RES28		0x0	/* 2/8 */
+/* Special Rx Condition Interrupts */
+#define	PAR_ERR		0x10	/* Parity error */
+#define	Rx_OVR		0x20	/* Rx Overrun Error */
+#define	CRC_ERR		0x40	/* CRC/Framing Error */
+#define	END_FR		0x80	/* End of Frame (SDLC) */
+
+/* Read Register 2 (channel b only) - Interrupt vector */
+#define	CHB_Tx_EMPTY	0x00
+#define	CHB_EXT_STAT	0x02
+#define	CHB_Rx_AVAIL	0x04
+#define	CHB_SPECIAL	0x06
+#define	CHA_Tx_EMPTY	0x08
+#define	CHA_EXT_STAT	0x0a
+#define	CHA_Rx_AVAIL	0x0c
+#define	CHA_SPECIAL	0x0e
+#define	STATUS_MASK	0x06
+
+/* Read Register 3 (interrupt pending register) ch a only */
+#define	CHBEXT	0x1		/* Channel B Ext/Stat IP */
+#define	CHBTxIP	0x2		/* Channel B Tx IP */
+#define	CHBRxIP	0x4		/* Channel B Rx IP */
+#define	CHAEXT	0x8		/* Channel A Ext/Stat IP */
+#define	CHATxIP	0x10		/* Channel A Tx IP */
+#define	CHARxIP	0x20		/* Channel A Rx IP */
+
+/* Read Register 8 (receive data register) */
+
+/* Read Register 10  (misc status bits) */
+#define	ONLOOP	2		/* On loop */
+#define	LOOPSEND 0x10		/* Loop sending */
+#define	CLK2MIS	0x40		/* Two clocks missing */
+#define	CLK1MIS	0x80		/* One clock missing */
+
+/* Read Register 12 (lower byte of baud rate generator constant) */
+
+/* Read Register 13 (upper byte of baud rate generator constant) */
+
+/* Read Register 15 (value of WR 15) */
+
+/* Misc macros */
+#define ZS_CLEARERR(port)    (write_zsreg(port, 0, ERR_RES))
+#define ZS_CLEARFIFO(port)   do {                       \
+				     read_zsdata(port); \
+				     read_zsdata(port); \
+				     read_zsdata(port); \
+				} while(0)
+
+#define ZS_IS_CONS(UP)			((UP)->flags & PMACZILOG_FLAG_IS_CONS)
+#define ZS_IS_KGDB(UP)			((UP)->flags & PMACZILOG_FLAG_IS_KGDB)
+#define ZS_IS_CHANNEL_A(UP)		((UP)->flags & PMACZILOG_FLAG_IS_CHANNEL_A)
+#define ZS_REGS_HELD(UP)		((UP)->flags & PMACZILOG_FLAG_REGS_HELD)
+#define ZS_TX_STOPPED(UP)		((UP)->flags & PMACZILOG_FLAG_TX_STOPPED)
+#define ZS_TX_ACTIVE(UP)		((UP)->flags & PMACZILOG_FLAG_TX_ACTIVE)
+#define ZS_WANTS_MODEM_STATUS(UP)	((UP)->flags & PMACZILOG_FLAG_MODEM_STATUS)
+#define ZS_IS_IRDA(UP)			((UP)->flags & PMACZILOG_FLAG_IS_IRDA)
+#define ZS_IS_INTMODEM(UP)		((UP)->flags & PMACZILOG_FLAG_IS_INTMODEM)
+#define ZS_IS_OPEN(UP)			((UP)->flags & PMACZILOG_FLAG_IS_OPEN)
+#define ZS_IS_EXTCLK(UP)		((UP)->flags & PMACZILOG_FLAG_IS_EXTCLK)
+
+#endif /* __PMAC_ZILOG_H__ */
diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
new file mode 100644
index 000000000..73c60f5ea
--- /dev/null
+++ b/drivers/tty/serial/pxa.c
@@ -0,0 +1,908 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Based on drivers/serial/8250.c by Russell King.
+ *
+ *  Author:	Nicolas Pitre
+ *  Created:	Feb 20, 2003
+ *  Copyright:	(C) 2003 Monta Vista Software, Inc.
+ *
+ * Note 1: This driver is made separate from the already too overloaded
+ * 8250.c because it needs some kirks of its own and that'll make it
+ * easier to add DMA support.
+ *
+ * Note 2: I'm too sick of device allocation policies for serial ports.
+ * If someone else wants to request an "official" allocation of major/minor
+ * for this driver please be my guest.  And don't forget that new hardware
+ * to come from Intel might have more than 3 or 4 of those UARTs.  Let's
+ * hope for a better port registration and dynamic device allocation scheme
+ * with the serial core maintainer satisfaction to appear soon.
+ */
+
+
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/circ_buf.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#define PXA_NAME_LEN		8
+
+struct uart_pxa_port {
+	struct uart_port        port;
+	unsigned char           ier;
+	unsigned char           lcr;
+	unsigned char           mcr;
+	unsigned int            lsr_break_flag;
+	struct clk		*clk;
+	char			name[PXA_NAME_LEN];
+};
+
+static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
+{
+	offset <<= 2;
+	return readl(up->port.membase + offset);
+}
+
+static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
+{
+	offset <<= 2;
+	writel(value, up->port.membase + offset);
+}
+
+static void serial_pxa_enable_ms(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void serial_pxa_stop_tx(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	if (up->ier & UART_IER_THRI) {
+		up->ier &= ~UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static void serial_pxa_stop_rx(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	up->ier &= ~UART_IER_RLSI;
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static inline void receive_chars(struct uart_pxa_port *up, int *status)
+{
+	u8 ch, flag;
+	int max_count = 256;
+
+	do {
+		/* work around Errata #20 according to
+		 * Intel(R) PXA27x Processor Family
+		 * Specification Update (May 2005)
+		 *
+		 * Step 2
+		 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
+		 */
+		up->ier &= ~UART_IER_RTOIE;
+		serial_out(up, UART_IER, up->ier);
+
+		ch = serial_in(up, UART_RX);
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
+				       UART_LSR_FE | UART_LSR_OE))) {
+			/*
+			 * For statistics only
+			 */
+			if (*status & UART_LSR_BI) {
+				*status &= ~(UART_LSR_FE | UART_LSR_PE);
+				up->port.icount.brk++;
+				/*
+				 * We do the SysRQ and SAK checking
+				 * here because otherwise the break
+				 * may get masked by ignore_status_mask
+				 * or read_status_mask.
+				 */
+				if (uart_handle_break(&up->port))
+					goto ignore_char;
+			} else if (*status & UART_LSR_PE)
+				up->port.icount.parity++;
+			else if (*status & UART_LSR_FE)
+				up->port.icount.frame++;
+			if (*status & UART_LSR_OE)
+				up->port.icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ignored.
+			 */
+			*status &= up->port.read_status_mask;
+
+#ifdef CONFIG_SERIAL_PXA_CONSOLE
+			if (up->port.line == up->port.cons->index) {
+				/* Recover the break flag from console xmit */
+				*status |= up->lsr_break_flag;
+				up->lsr_break_flag = 0;
+			}
+#endif
+			if (*status & UART_LSR_BI) {
+				flag = TTY_BREAK;
+			} else if (*status & UART_LSR_PE)
+				flag = TTY_PARITY;
+			else if (*status & UART_LSR_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(&up->port, ch))
+			goto ignore_char;
+
+		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
+
+	ignore_char:
+		*status = serial_in(up, UART_LSR);
+	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
+	tty_flip_buffer_push(&up->port.state->port);
+
+	/* work around Errata #20 according to
+	 * Intel(R) PXA27x Processor Family
+	 * Specification Update (May 2005)
+	 *
+	 * Step 6:
+	 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
+	 */
+	up->ier |= UART_IER_RTOIE;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void transmit_chars(struct uart_pxa_port *up)
+{
+	u8 ch;
+
+	uart_port_tx_limited(&up->port, ch, up->port.fifosize / 2,
+		true,
+		serial_out(up, UART_TX, ch),
+		({}));
+}
+
+static void serial_pxa_start_tx(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+/* should hold up->port.lock */
+static inline void check_modem_status(struct uart_pxa_port *up)
+{
+	int status;
+
+	status = serial_in(up, UART_MSR);
+
+	if ((status & UART_MSR_ANY_DELTA) == 0)
+		return;
+
+	if (status & UART_MSR_TERI)
+		up->port.icount.rng++;
+	if (status & UART_MSR_DDSR)
+		up->port.icount.dsr++;
+	if (status & UART_MSR_DDCD)
+		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
+	if (status & UART_MSR_DCTS)
+		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
+
+	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+}
+
+/*
+ * This handles the interrupt from one port.
+ */
+static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
+{
+	struct uart_pxa_port *up = dev_id;
+	unsigned int iir, lsr;
+
+	iir = serial_in(up, UART_IIR);
+	if (iir & UART_IIR_NO_INT)
+		return IRQ_NONE;
+	spin_lock(&up->port.lock);
+	lsr = serial_in(up, UART_LSR);
+	if (lsr & UART_LSR_DR)
+		receive_chars(up, &lsr);
+	check_modem_status(up);
+	if (lsr & UART_LSR_THRE)
+		transmit_chars(up);
+	spin_unlock(&up->port.lock);
+	return IRQ_HANDLED;
+}
+
+static unsigned int serial_pxa_tx_empty(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned long flags;
+	unsigned int ret;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return ret;
+}
+
+static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned char status;
+	unsigned int ret;
+
+	status = serial_in(up, UART_MSR);
+
+	ret = 0;
+	if (status & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+	if (status & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+	if (status & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+	if (status & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned char mcr = 0;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (mctrl & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	mcr |= up->mcr;
+
+	serial_out(up, UART_MCR, mcr);
+}
+
+static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_out(up, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int serial_pxa_startup(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned long flags;
+	int retval;
+
+	if (port->line == 3) /* HWUART */
+		up->mcr |= UART_MCR_AFE;
+	else
+		up->mcr = 0;
+
+	up->port.uartclk = clk_get_rate(up->clk);
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
+	if (retval)
+		return retval;
+
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_FCR, 0);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) serial_in(up, UART_LSR);
+	(void) serial_in(up, UART_RX);
+	(void) serial_in(up, UART_IIR);
+	(void) serial_in(up, UART_MSR);
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->port.mctrl |= TIOCM_OUT2;
+	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/*
+	 * Finally, enable interrupts.  Note: Modem status interrupts
+	 * are set via set_termios(), which will be occurring imminently
+	 * anyway, so we don't enable them here.
+	 */
+	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
+	serial_out(up, UART_IER, up->ier);
+
+	/*
+	 * And clear the interrupt registers again for luck.
+	 */
+	(void) serial_in(up, UART_LSR);
+	(void) serial_in(up, UART_RX);
+	(void) serial_in(up, UART_IIR);
+	(void) serial_in(up, UART_MSR);
+
+	return 0;
+}
+
+static void serial_pxa_shutdown(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned long flags;
+
+	free_irq(up->port.irq, up);
+
+	/*
+	 * Disable interrupts from this port
+	 */
+	up->ier = 0;
+	serial_out(up, UART_IER, 0);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->port.mctrl &= ~TIOCM_OUT2;
+	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+				  UART_FCR_CLEAR_RCVR |
+				  UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_FCR, 0);
+}
+
+static void
+serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
+		       const struct ktermios *old)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned char cval, fcr = 0;
+	unsigned long flags;
+	unsigned int baud, quot;
+	unsigned int dll;
+
+	cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+	if (termios->c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (termios->c_cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(termios->c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+	quot = uart_get_divisor(port, baud);
+
+	if ((up->port.uartclk / quot) < (2400 * 16))
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
+	else if ((up->port.uartclk / quot) < (230400 * 16))
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
+	else
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Ensure the port will be enabled.
+	 * This is required especially for serial console.
+	 */
+	up->ier |= UART_IER_UUE;
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		up->port.read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * CTS flow control flag and modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+
+	serial_out(up, UART_IER, up->ier);
+
+	if (termios->c_cflag & CRTSCTS)
+		up->mcr |= UART_MCR_AFE;
+	else
+		up->mcr &= ~UART_MCR_AFE;
+
+	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
+	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
+
+	/*
+	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
+	 * Specification Update (Nov 2005)
+	 */
+	dll = serial_in(up, UART_DLL);
+	WARN_ON(dll != (quot & 0xff));
+
+	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
+	serial_out(up, UART_LCR, cval);			/* reset DLAB */
+	up->lcr = cval;					/* Save LCR */
+	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
+	serial_out(up, UART_FCR, fcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void
+serial_pxa_pm(struct uart_port *port, unsigned int state,
+	      unsigned int oldstate)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	if (!state)
+		clk_prepare_enable(up->clk);
+	else
+		clk_disable_unprepare(up->clk);
+}
+
+static void serial_pxa_release_port(struct uart_port *port)
+{
+}
+
+static int serial_pxa_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void serial_pxa_config_port(struct uart_port *port, int flags)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	up->port.type = PORT_PXA;
+}
+
+static int
+serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* we don't want the core code to modify any port params */
+	return -EINVAL;
+}
+
+static const char *
+serial_pxa_type(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	return up->name;
+}
+
+static struct uart_pxa_port *serial_pxa_ports[4];
+static struct uart_driver serial_pxa_reg;
+
+#ifdef CONFIG_SERIAL_PXA_CONSOLE
+
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_pxa_port *up)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	do {
+		status = serial_in(up, UART_LSR);
+
+		if (status & UART_LSR_BI)
+			up->lsr_break_flag = UART_LSR_BI;
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (!uart_lsr_tx_empty(status));
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		while (--tmout &&
+		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
+			udelay(1);
+	}
+}
+
+static void serial_pxa_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	wait_for_xmitr(up);
+	serial_out(up, UART_TX, ch);
+}
+
+/*
+ * Print a string to the serial port trying not to disturb
+ * any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ */
+static void
+serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_pxa_port *up = serial_pxa_ports[co->index];
+	unsigned int ier;
+	unsigned long flags;
+	int locked = 1;
+
+	clk_enable(up->clk);
+	local_irq_save(flags);
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&up->port.lock);
+	else
+		spin_lock(&up->port.lock);
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, UART_IER_UUE);
+
+	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, UART_IER, ier);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+	local_irq_restore(flags);
+	clk_disable(up->clk);
+
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial_pxa_get_poll_char(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned char lsr = serial_in(up, UART_LSR);
+
+	while (!(lsr & UART_LSR_DR))
+		lsr = serial_in(up, UART_LSR);
+
+	return serial_in(up, UART_RX);
+}
+
+
+static void serial_pxa_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, UART_IER_UUE);
+
+	wait_for_xmitr(up);
+	/*
+	 *	Send the character out.
+	 */
+	serial_out(up, UART_TX, c);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, UART_IER, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static int __init
+serial_pxa_console_setup(struct console *co, char *options)
+{
+	struct uart_pxa_port *up;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
+		co->index = 0;
+	up = serial_pxa_ports[co->index];
+	if (!up)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&up->port, co, baud, parity, bits, flow);
+}
+
+static struct console serial_pxa_console = {
+	.name		= "ttyS",
+	.write		= serial_pxa_console_write,
+	.device		= uart_console_device,
+	.setup		= serial_pxa_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial_pxa_reg,
+};
+
+#define PXA_CONSOLE	&serial_pxa_console
+#else
+#define PXA_CONSOLE	NULL
+#endif
+
+static const struct uart_ops serial_pxa_pops = {
+	.tx_empty	= serial_pxa_tx_empty,
+	.set_mctrl	= serial_pxa_set_mctrl,
+	.get_mctrl	= serial_pxa_get_mctrl,
+	.stop_tx	= serial_pxa_stop_tx,
+	.start_tx	= serial_pxa_start_tx,
+	.stop_rx	= serial_pxa_stop_rx,
+	.enable_ms	= serial_pxa_enable_ms,
+	.break_ctl	= serial_pxa_break_ctl,
+	.startup	= serial_pxa_startup,
+	.shutdown	= serial_pxa_shutdown,
+	.set_termios	= serial_pxa_set_termios,
+	.pm		= serial_pxa_pm,
+	.type		= serial_pxa_type,
+	.release_port	= serial_pxa_release_port,
+	.request_port	= serial_pxa_request_port,
+	.config_port	= serial_pxa_config_port,
+	.verify_port	= serial_pxa_verify_port,
+#if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_PXA_CONSOLE)
+	.poll_get_char = serial_pxa_get_poll_char,
+	.poll_put_char = serial_pxa_put_poll_char,
+#endif
+};
+
+static struct uart_driver serial_pxa_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "PXA serial",
+	.dev_name	= "ttyS",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= 4,
+	.cons		= PXA_CONSOLE,
+};
+
+#ifdef CONFIG_PM
+static int serial_pxa_suspend(struct device *dev)
+{
+        struct uart_pxa_port *sport = dev_get_drvdata(dev);
+
+        if (sport)
+                uart_suspend_port(&serial_pxa_reg, &sport->port);
+
+        return 0;
+}
+
+static int serial_pxa_resume(struct device *dev)
+{
+        struct uart_pxa_port *sport = dev_get_drvdata(dev);
+
+        if (sport)
+                uart_resume_port(&serial_pxa_reg, &sport->port);
+
+        return 0;
+}
+
+static const struct dev_pm_ops serial_pxa_pm_ops = {
+	.suspend	= serial_pxa_suspend,
+	.resume		= serial_pxa_resume,
+};
+#endif
+
+static const struct of_device_id serial_pxa_dt_ids[] = {
+	{ .compatible = "mrvl,pxa-uart", },
+	{ .compatible = "mrvl,mmp-uart", },
+	{}
+};
+
+static int serial_pxa_probe_dt(struct platform_device *pdev,
+			       struct uart_pxa_port *sport)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int ret;
+
+	if (!np)
+		return 1;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+		return ret;
+	}
+	sport->port.line = ret;
+	return 0;
+}
+
+static int serial_pxa_probe(struct platform_device *dev)
+{
+	struct uart_pxa_port *sport;
+	struct resource *mmres;
+	int ret;
+	int irq;
+
+	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!mmres)
+		return -ENODEV;
+
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0)
+		return irq;
+
+	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	sport->clk = clk_get(&dev->dev, NULL);
+	if (IS_ERR(sport->clk)) {
+		ret = PTR_ERR(sport->clk);
+		goto err_free;
+	}
+
+	ret = clk_prepare(sport->clk);
+	if (ret) {
+		clk_put(sport->clk);
+		goto err_free;
+	}
+
+	sport->port.type = PORT_PXA;
+	sport->port.iotype = UPIO_MEM;
+	sport->port.mapbase = mmres->start;
+	sport->port.irq = irq;
+	sport->port.fifosize = 64;
+	sport->port.ops = &serial_pxa_pops;
+	sport->port.dev = &dev->dev;
+	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
+	sport->port.uartclk = clk_get_rate(sport->clk);
+	sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_PXA_CONSOLE);
+
+	ret = serial_pxa_probe_dt(dev, sport);
+	if (ret > 0)
+		sport->port.line = dev->id;
+	else if (ret < 0)
+		goto err_clk;
+	if (sport->port.line >= ARRAY_SIZE(serial_pxa_ports)) {
+		dev_err(&dev->dev, "serial%d out of range\n", sport->port.line);
+		ret = -EINVAL;
+		goto err_clk;
+	}
+	snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
+
+	sport->port.membase = ioremap(mmres->start, resource_size(mmres));
+	if (!sport->port.membase) {
+		ret = -ENOMEM;
+		goto err_clk;
+	}
+
+	serial_pxa_ports[sport->port.line] = sport;
+
+	uart_add_one_port(&serial_pxa_reg, &sport->port);
+	platform_set_drvdata(dev, sport);
+
+	return 0;
+
+ err_clk:
+	clk_unprepare(sport->clk);
+	clk_put(sport->clk);
+ err_free:
+	kfree(sport);
+	return ret;
+}
+
+static struct platform_driver serial_pxa_driver = {
+        .probe          = serial_pxa_probe,
+
+	.driver		= {
+	        .name	= "pxa2xx-uart",
+#ifdef CONFIG_PM
+		.pm	= &serial_pxa_pm_ops,
+#endif
+		.suppress_bind_attrs = true,
+		.of_match_table = serial_pxa_dt_ids,
+	},
+};
+
+
+/* 8250 driver for PXA serial ports should be used */
+static int __init serial_pxa_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&serial_pxa_reg);
+	if (ret != 0)
+		return ret;
+
+	ret = platform_driver_register(&serial_pxa_driver);
+	if (ret != 0)
+		uart_unregister_driver(&serial_pxa_reg);
+
+	return ret;
+}
+device_initcall(serial_pxa_init);
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
new file mode 100644
index 000000000..b8aa4c129
--- /dev/null
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -0,0 +1,1849 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
+
+/* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */
+#define __DISABLE_TRACE_MMIO__
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_opp.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/soc/qcom/geni-se.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <dt-bindings/interconnect/qcom,icc.h>
+
+/* UART specific GENI registers */
+#define SE_UART_LOOPBACK_CFG		0x22c
+#define SE_UART_IO_MACRO_CTRL		0x240
+#define SE_UART_TX_TRANS_CFG		0x25c
+#define SE_UART_TX_WORD_LEN		0x268
+#define SE_UART_TX_STOP_BIT_LEN		0x26c
+#define SE_UART_TX_TRANS_LEN		0x270
+#define SE_UART_RX_TRANS_CFG		0x280
+#define SE_UART_RX_WORD_LEN		0x28c
+#define SE_UART_RX_STALE_CNT		0x294
+#define SE_UART_TX_PARITY_CFG		0x2a4
+#define SE_UART_RX_PARITY_CFG		0x2a8
+#define SE_UART_MANUAL_RFR		0x2ac
+
+/* SE_UART_TRANS_CFG */
+#define UART_TX_PAR_EN			BIT(0)
+#define UART_CTS_MASK			BIT(1)
+
+/* SE_UART_TX_STOP_BIT_LEN */
+#define TX_STOP_BIT_LEN_1		0
+#define TX_STOP_BIT_LEN_2		2
+
+/* SE_UART_RX_TRANS_CFG */
+#define UART_RX_PAR_EN			BIT(3)
+
+/* SE_UART_RX_WORD_LEN */
+#define RX_WORD_LEN_MASK		GENMASK(9, 0)
+
+/* SE_UART_RX_STALE_CNT */
+#define RX_STALE_CNT			GENMASK(23, 0)
+
+/* SE_UART_TX_PARITY_CFG/RX_PARITY_CFG */
+#define PAR_CALC_EN			BIT(0)
+#define PAR_EVEN			0x00
+#define PAR_ODD				0x01
+#define PAR_SPACE			0x10
+
+/* SE_UART_MANUAL_RFR register fields */
+#define UART_MANUAL_RFR_EN		BIT(31)
+#define UART_RFR_NOT_READY		BIT(1)
+#define UART_RFR_READY			BIT(0)
+
+/* UART M_CMD OP codes */
+#define UART_START_TX			0x1
+/* UART S_CMD OP codes */
+#define UART_START_READ			0x1
+#define UART_PARAM			0x1
+#define UART_PARAM_RFR_OPEN		BIT(7)
+
+#define UART_OVERSAMPLING		32
+#define STALE_TIMEOUT			16
+#define DEFAULT_BITS_PER_CHAR		10
+#define GENI_UART_CONS_PORTS		1
+#define GENI_UART_PORTS			3
+#define DEF_FIFO_DEPTH_WORDS		16
+#define DEF_TX_WM			2
+#define DEF_FIFO_WIDTH_BITS		32
+#define UART_RX_WM			2
+
+/* SE_UART_LOOPBACK_CFG */
+#define RX_TX_SORTED			BIT(0)
+#define CTS_RTS_SORTED			BIT(1)
+#define RX_TX_CTS_RTS_SORTED		(RX_TX_SORTED | CTS_RTS_SORTED)
+
+/* UART pin swap value */
+#define DEFAULT_IO_MACRO_IO0_IO1_MASK	GENMASK(3, 0)
+#define IO_MACRO_IO0_SEL		0x3
+#define DEFAULT_IO_MACRO_IO2_IO3_MASK	GENMASK(15, 4)
+#define IO_MACRO_IO2_IO3_SWAP		0x4640
+
+/* We always configure 4 bytes per FIFO word */
+#define BYTES_PER_FIFO_WORD		4U
+
+#define DMA_RX_BUF_SIZE		2048
+
+struct qcom_geni_device_data {
+	bool console;
+	enum geni_se_xfer_mode mode;
+};
+
+struct qcom_geni_private_data {
+	/* NOTE: earlycon port will have NULL here */
+	struct uart_driver *drv;
+
+	u32 poll_cached_bytes;
+	unsigned int poll_cached_bytes_cnt;
+
+	u32 write_cached_bytes;
+	unsigned int write_cached_bytes_cnt;
+};
+
+struct qcom_geni_serial_port {
+	struct uart_port uport;
+	struct geni_se se;
+	const char *name;
+	u32 tx_fifo_depth;
+	u32 tx_fifo_width;
+	u32 rx_fifo_depth;
+	dma_addr_t tx_dma_addr;
+	dma_addr_t rx_dma_addr;
+	bool setup;
+	unsigned int baud;
+	unsigned long clk_rate;
+	void *rx_buf;
+	u32 loopback;
+	bool brk;
+
+	unsigned int tx_remaining;
+	int wakeup_irq;
+	bool rx_tx_swap;
+	bool cts_rts_swap;
+
+	struct qcom_geni_private_data private_data;
+	const struct qcom_geni_device_data *dev_data;
+};
+
+static const struct uart_ops qcom_geni_console_pops;
+static const struct uart_ops qcom_geni_uart_pops;
+static struct uart_driver qcom_geni_console_driver;
+static struct uart_driver qcom_geni_uart_driver;
+
+static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport)
+{
+	return container_of(uport, struct qcom_geni_serial_port, uport);
+}
+
+static struct qcom_geni_serial_port qcom_geni_uart_ports[GENI_UART_PORTS] = {
+	[0] = {
+		.uport = {
+			.iotype = UPIO_MEM,
+			.ops = &qcom_geni_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.line = 0,
+		},
+	},
+	[1] = {
+		.uport = {
+			.iotype = UPIO_MEM,
+			.ops = &qcom_geni_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.line = 1,
+		},
+	},
+	[2] = {
+		.uport = {
+			.iotype = UPIO_MEM,
+			.ops = &qcom_geni_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.line = 2,
+		},
+	},
+};
+
+static struct qcom_geni_serial_port qcom_geni_console_port = {
+	.uport = {
+		.iotype = UPIO_MEM,
+		.ops = &qcom_geni_console_pops,
+		.flags = UPF_BOOT_AUTOCONF,
+		.line = 0,
+	},
+};
+
+static int qcom_geni_serial_request_port(struct uart_port *uport)
+{
+	struct platform_device *pdev = to_platform_device(uport->dev);
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	uport->membase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(uport->membase))
+		return PTR_ERR(uport->membase);
+	port->se.base = uport->membase;
+	return 0;
+}
+
+static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
+{
+	if (cfg_flags & UART_CONFIG_TYPE) {
+		uport->type = PORT_MSM;
+		qcom_geni_serial_request_port(uport);
+	}
+}
+
+static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
+{
+	unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
+	u32 geni_ios;
+
+	if (uart_console(uport)) {
+		mctrl |= TIOCM_CTS;
+	} else {
+		geni_ios = readl(uport->membase + SE_GENI_IOS);
+		if (!(geni_ios & IO2_DATA_IN))
+			mctrl |= TIOCM_CTS;
+	}
+
+	return mctrl;
+}
+
+static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
+							unsigned int mctrl)
+{
+	u32 uart_manual_rfr = 0;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	if (uart_console(uport))
+		return;
+
+	if (mctrl & TIOCM_LOOP)
+		port->loopback = RX_TX_CTS_RTS_SORTED;
+
+	if (!(mctrl & TIOCM_RTS) && !uport->suspended)
+		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
+	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
+}
+
+static const char *qcom_geni_serial_get_type(struct uart_port *uport)
+{
+	return "MSM";
+}
+
+static struct qcom_geni_serial_port *get_port_from_line(int line, bool console)
+{
+	struct qcom_geni_serial_port *port;
+	int nr_ports = console ? GENI_UART_CONS_PORTS : GENI_UART_PORTS;
+
+	if (line < 0 || line >= nr_ports)
+		return ERR_PTR(-ENXIO);
+
+	port = console ? &qcom_geni_console_port : &qcom_geni_uart_ports[line];
+	return port;
+}
+
+static bool qcom_geni_serial_main_active(struct uart_port *uport)
+{
+	return readl(uport->membase + SE_GENI_STATUS) & M_GENI_CMD_ACTIVE;
+}
+
+static bool qcom_geni_serial_secondary_active(struct uart_port *uport)
+{
+	return readl(uport->membase + SE_GENI_STATUS) & S_GENI_CMD_ACTIVE;
+}
+
+static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
+				int offset, int field, bool set)
+{
+	u32 reg;
+	struct qcom_geni_serial_port *port;
+	unsigned int baud;
+	unsigned int fifo_bits;
+	unsigned long timeout_us = 20000;
+	struct qcom_geni_private_data *private_data = uport->private_data;
+
+	if (private_data->drv) {
+		port = to_dev_port(uport);
+		baud = port->baud;
+		if (!baud)
+			baud = 115200;
+		fifo_bits = port->tx_fifo_depth * port->tx_fifo_width;
+		/*
+		 * Total polling iterations based on FIFO worth of bytes to be
+		 * sent at current baud. Add a little fluff to the wait.
+		 */
+		timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
+	}
+
+	/*
+	 * Use custom implementation instead of readl_poll_atomic since ktimer
+	 * is not ready at the time of early console.
+	 */
+	timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
+	while (timeout_us) {
+		reg = readl(uport->membase + offset);
+		if ((bool)(reg & field) == set)
+			return true;
+		udelay(10);
+		timeout_us -= 10;
+	}
+	return false;
+}
+
+static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
+{
+	u32 m_cmd;
+
+	writel(xmit_size, uport->membase + SE_UART_TX_TRANS_LEN);
+	m_cmd = UART_START_TX << M_OPCODE_SHFT;
+	writel(m_cmd, uport->membase + SE_GENI_M_CMD0);
+}
+
+static void qcom_geni_serial_poll_tx_done(struct uart_port *uport)
+{
+	int done;
+	u32 irq_clear = M_CMD_DONE_EN;
+
+	done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						M_CMD_DONE_EN, true);
+	if (!done) {
+		writel(M_GENI_CMD_ABORT, uport->membase +
+						SE_GENI_M_CMD_CTRL_REG);
+		irq_clear |= M_CMD_ABORT_EN;
+		qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+							M_CMD_ABORT_EN, true);
+	}
+	writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR);
+}
+
+static void qcom_geni_serial_abort_rx(struct uart_port *uport)
+{
+	u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
+
+	writel(S_GENI_CMD_ABORT, uport->membase + SE_GENI_S_CMD_CTRL_REG);
+	qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
+					S_GENI_CMD_ABORT, false);
+	writel(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
+	writel(FORCE_DEFAULT, uport->membase + GENI_FORCE_DEFAULT_REG);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int qcom_geni_serial_get_char(struct uart_port *uport)
+{
+	struct qcom_geni_private_data *private_data = uport->private_data;
+	u32 status;
+	u32 word_cnt;
+	int ret;
+
+	if (!private_data->poll_cached_bytes_cnt) {
+		status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
+		writel(status, uport->membase + SE_GENI_M_IRQ_CLEAR);
+
+		status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
+		writel(status, uport->membase + SE_GENI_S_IRQ_CLEAR);
+
+		status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
+		word_cnt = status & RX_FIFO_WC_MSK;
+		if (!word_cnt)
+			return NO_POLL_CHAR;
+
+		if (word_cnt == 1 && (status & RX_LAST))
+			/*
+			 * NOTE: If RX_LAST_BYTE_VALID is 0 it needs to be
+			 * treated as if it was BYTES_PER_FIFO_WORD.
+			 */
+			private_data->poll_cached_bytes_cnt =
+				(status & RX_LAST_BYTE_VALID_MSK) >>
+				RX_LAST_BYTE_VALID_SHFT;
+
+		if (private_data->poll_cached_bytes_cnt == 0)
+			private_data->poll_cached_bytes_cnt = BYTES_PER_FIFO_WORD;
+
+		private_data->poll_cached_bytes =
+			readl(uport->membase + SE_GENI_RX_FIFOn);
+	}
+
+	private_data->poll_cached_bytes_cnt--;
+	ret = private_data->poll_cached_bytes & 0xff;
+	private_data->poll_cached_bytes >>= 8;
+
+	return ret;
+}
+
+static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
+							unsigned char c)
+{
+	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
+	qcom_geni_serial_setup_tx(uport, 1);
+	WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						M_TX_FIFO_WATERMARK_EN, true));
+	writel(c, uport->membase + SE_GENI_TX_FIFOn);
+	writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
+	qcom_geni_serial_poll_tx_done(uport);
+}
+#endif
+
+#ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
+static void qcom_geni_serial_wr_char(struct uart_port *uport, unsigned char ch)
+{
+	struct qcom_geni_private_data *private_data = uport->private_data;
+
+	private_data->write_cached_bytes =
+		(private_data->write_cached_bytes >> 8) | (ch << 24);
+	private_data->write_cached_bytes_cnt++;
+
+	if (private_data->write_cached_bytes_cnt == BYTES_PER_FIFO_WORD) {
+		writel(private_data->write_cached_bytes,
+		       uport->membase + SE_GENI_TX_FIFOn);
+		private_data->write_cached_bytes_cnt = 0;
+	}
+}
+
+static void
+__qcom_geni_serial_console_write(struct uart_port *uport, const char *s,
+				 unsigned int count)
+{
+	struct qcom_geni_private_data *private_data = uport->private_data;
+
+	int i;
+	u32 bytes_to_send = count;
+
+	for (i = 0; i < count; i++) {
+		/*
+		 * uart_console_write() adds a carriage return for each newline.
+		 * Account for additional bytes to be written.
+		 */
+		if (s[i] == '\n')
+			bytes_to_send++;
+	}
+
+	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
+	qcom_geni_serial_setup_tx(uport, bytes_to_send);
+	for (i = 0; i < count; ) {
+		size_t chars_to_write = 0;
+		size_t avail = DEF_FIFO_DEPTH_WORDS - DEF_TX_WM;
+
+		/*
+		 * If the WM bit never set, then the Tx state machine is not
+		 * in a valid state, so break, cancel/abort any existing
+		 * command. Unfortunately the current data being written is
+		 * lost.
+		 */
+		if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						M_TX_FIFO_WATERMARK_EN, true))
+			break;
+		chars_to_write = min_t(size_t, count - i, avail / 2);
+		uart_console_write(uport, s + i, chars_to_write,
+						qcom_geni_serial_wr_char);
+		writel(M_TX_FIFO_WATERMARK_EN, uport->membase +
+							SE_GENI_M_IRQ_CLEAR);
+		i += chars_to_write;
+	}
+
+	if (private_data->write_cached_bytes_cnt) {
+		private_data->write_cached_bytes >>= BITS_PER_BYTE *
+			(BYTES_PER_FIFO_WORD - private_data->write_cached_bytes_cnt);
+		writel(private_data->write_cached_bytes,
+		       uport->membase + SE_GENI_TX_FIFOn);
+		private_data->write_cached_bytes_cnt = 0;
+	}
+
+	qcom_geni_serial_poll_tx_done(uport);
+}
+
+static void qcom_geni_serial_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	struct uart_port *uport;
+	struct qcom_geni_serial_port *port;
+	bool locked = true;
+	unsigned long flags;
+	u32 geni_status;
+	u32 irq_en;
+
+	WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
+
+	port = get_port_from_line(co->index, true);
+	if (IS_ERR(port))
+		return;
+
+	uport = &port->uport;
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&uport->lock, flags);
+	else
+		spin_lock_irqsave(&uport->lock, flags);
+
+	geni_status = readl(uport->membase + SE_GENI_STATUS);
+
+	/* Cancel the current write to log the fault */
+	if (!locked) {
+		geni_se_cancel_m_cmd(&port->se);
+		if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						M_CMD_CANCEL_EN, true)) {
+			geni_se_abort_m_cmd(&port->se);
+			qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+							M_CMD_ABORT_EN, true);
+			writel(M_CMD_ABORT_EN, uport->membase +
+							SE_GENI_M_IRQ_CLEAR);
+		}
+		writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
+	} else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) {
+		/*
+		 * It seems we can't interrupt existing transfers if all data
+		 * has been sent, in which case we need to look for done first.
+		 */
+		qcom_geni_serial_poll_tx_done(uport);
+
+		if (!uart_circ_empty(&uport->state->xmit)) {
+			irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+			writel(irq_en | M_TX_FIFO_WATERMARK_EN,
+					uport->membase + SE_GENI_M_IRQ_EN);
+		}
+	}
+
+	__qcom_geni_serial_console_write(uport, s, count);
+
+	if (port->tx_remaining)
+		qcom_geni_serial_setup_tx(uport, port->tx_remaining);
+
+	if (locked)
+		spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
+{
+	u32 i;
+	unsigned char buf[sizeof(u32)];
+	struct tty_port *tport;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	tport = &uport->state->port;
+	for (i = 0; i < bytes; ) {
+		int c;
+		int chunk = min_t(int, bytes - i, BYTES_PER_FIFO_WORD);
+
+		ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, buf, 1);
+		i += chunk;
+		if (drop)
+			continue;
+
+		for (c = 0; c < chunk; c++) {
+			int sysrq;
+
+			uport->icount.rx++;
+			if (port->brk && buf[c] == 0) {
+				port->brk = false;
+				if (uart_handle_break(uport))
+					continue;
+			}
+
+			sysrq = uart_prepare_sysrq_char(uport, buf[c]);
+
+			if (!sysrq)
+				tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
+		}
+	}
+	if (!drop)
+		tty_flip_buffer_push(tport);
+}
+#else
+static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
+{
+
+}
+#endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
+
+static void handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	struct tty_port *tport = &uport->state->port;
+	int ret;
+
+	ret = tty_insert_flip_string(tport, port->rx_buf, bytes);
+	if (ret != bytes) {
+		dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n",
+				__func__, ret, bytes);
+		WARN_ON_ONCE(1);
+	}
+	uport->icount.rx += ret;
+	tty_flip_buffer_push(tport);
+}
+
+static unsigned int qcom_geni_serial_tx_empty(struct uart_port *uport)
+{
+	return !readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
+}
+
+static void qcom_geni_serial_stop_tx_dma(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	bool done;
+
+	if (!qcom_geni_serial_main_active(uport))
+		return;
+
+	if (port->tx_dma_addr) {
+		geni_se_tx_dma_unprep(&port->se, port->tx_dma_addr,
+				      port->tx_remaining);
+		port->tx_dma_addr = 0;
+		port->tx_remaining = 0;
+	}
+
+	geni_se_cancel_m_cmd(&port->se);
+
+	done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+					 M_CMD_CANCEL_EN, true);
+	if (!done) {
+		geni_se_abort_m_cmd(&port->se);
+		done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						 M_CMD_ABORT_EN, true);
+		if (!done)
+			dev_err_ratelimited(uport->dev, "M_CMD_ABORT_EN not set");
+		writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
+	}
+
+	writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
+}
+
+static void qcom_geni_serial_start_tx_dma(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	struct circ_buf *xmit = &uport->state->xmit;
+	unsigned int xmit_size;
+	int ret;
+
+	if (port->tx_dma_addr)
+		return;
+
+	if (uart_circ_empty(xmit))
+		return;
+
+	xmit_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	qcom_geni_serial_setup_tx(uport, xmit_size);
+
+	ret = geni_se_tx_dma_prep(&port->se, &xmit->buf[xmit->tail],
+				  xmit_size, &port->tx_dma_addr);
+	if (ret) {
+		dev_err(uport->dev, "unable to start TX SE DMA: %d\n", ret);
+		qcom_geni_serial_stop_tx_dma(uport);
+		return;
+	}
+
+	port->tx_remaining = xmit_size;
+}
+
+static void qcom_geni_serial_start_tx_fifo(struct uart_port *uport)
+{
+	u32 irq_en;
+
+	if (qcom_geni_serial_main_active(uport) ||
+	    !qcom_geni_serial_tx_empty(uport))
+		return;
+
+	irq_en = readl(uport->membase +	SE_GENI_M_IRQ_EN);
+	irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
+
+	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
+	writel(irq_en, uport->membase +	SE_GENI_M_IRQ_EN);
+}
+
+static void qcom_geni_serial_stop_tx_fifo(struct uart_port *uport)
+{
+	u32 irq_en;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+	irq_en &= ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN);
+	writel(0, uport->membase + SE_GENI_TX_WATERMARK_REG);
+	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
+	/* Possible stop tx is called multiple times. */
+	if (!qcom_geni_serial_main_active(uport))
+		return;
+
+	geni_se_cancel_m_cmd(&port->se);
+	if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						M_CMD_CANCEL_EN, true)) {
+		geni_se_abort_m_cmd(&port->se);
+		qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
+						M_CMD_ABORT_EN, true);
+		writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
+	}
+	writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
+}
+
+static void qcom_geni_serial_handle_rx_fifo(struct uart_port *uport, bool drop)
+{
+	u32 status;
+	u32 word_cnt;
+	u32 last_word_byte_cnt;
+	u32 last_word_partial;
+	u32 total_bytes;
+
+	status = readl(uport->membase +	SE_GENI_RX_FIFO_STATUS);
+	word_cnt = status & RX_FIFO_WC_MSK;
+	last_word_partial = status & RX_LAST;
+	last_word_byte_cnt = (status & RX_LAST_BYTE_VALID_MSK) >>
+						RX_LAST_BYTE_VALID_SHFT;
+
+	if (!word_cnt)
+		return;
+	total_bytes = BYTES_PER_FIFO_WORD * (word_cnt - 1);
+	if (last_word_partial && last_word_byte_cnt)
+		total_bytes += last_word_byte_cnt;
+	else
+		total_bytes += BYTES_PER_FIFO_WORD;
+	handle_rx_console(uport, total_bytes, drop);
+}
+
+static void qcom_geni_serial_stop_rx_fifo(struct uart_port *uport)
+{
+	u32 irq_en;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	u32 s_irq_status;
+
+	irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
+	irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
+	writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
+
+	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+	irq_en &= ~(M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
+	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
+
+	if (!qcom_geni_serial_secondary_active(uport))
+		return;
+
+	geni_se_cancel_s_cmd(&port->se);
+	qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
+					S_CMD_CANCEL_EN, true);
+	/*
+	 * If timeout occurs secondary engine remains active
+	 * and Abort sequence is executed.
+	 */
+	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
+	/* Flush the Rx buffer */
+	if (s_irq_status & S_RX_FIFO_LAST_EN)
+		qcom_geni_serial_handle_rx_fifo(uport, true);
+	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
+
+	if (qcom_geni_serial_secondary_active(uport))
+		qcom_geni_serial_abort_rx(uport);
+}
+
+static void qcom_geni_serial_start_rx_fifo(struct uart_port *uport)
+{
+	u32 irq_en;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	if (qcom_geni_serial_secondary_active(uport))
+		qcom_geni_serial_stop_rx_fifo(uport);
+
+	geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
+
+	irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
+	irq_en |= S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN;
+	writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
+
+	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+	irq_en |= M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN;
+	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
+}
+
+static void qcom_geni_serial_stop_rx_dma(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	if (!qcom_geni_serial_secondary_active(uport))
+		return;
+
+	geni_se_cancel_s_cmd(&port->se);
+	qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
+				  S_CMD_CANCEL_EN, true);
+
+	if (qcom_geni_serial_secondary_active(uport))
+		qcom_geni_serial_abort_rx(uport);
+
+	if (port->rx_dma_addr) {
+		geni_se_rx_dma_unprep(&port->se, port->rx_dma_addr,
+				      DMA_RX_BUF_SIZE);
+		port->rx_dma_addr = 0;
+	}
+}
+
+static void qcom_geni_serial_start_rx_dma(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	int ret;
+
+	if (qcom_geni_serial_secondary_active(uport))
+		qcom_geni_serial_stop_rx_dma(uport);
+
+	geni_se_setup_s_cmd(&port->se, UART_START_READ, UART_PARAM_RFR_OPEN);
+
+	ret = geni_se_rx_dma_prep(&port->se, port->rx_buf,
+				  DMA_RX_BUF_SIZE,
+				  &port->rx_dma_addr);
+	if (ret) {
+		dev_err(uport->dev, "unable to start RX SE DMA: %d\n", ret);
+		qcom_geni_serial_stop_rx_dma(uport);
+	}
+}
+
+static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	u32 rx_in;
+	int ret;
+
+	if (!qcom_geni_serial_secondary_active(uport))
+		return;
+
+	if (!port->rx_dma_addr)
+		return;
+
+	geni_se_rx_dma_unprep(&port->se, port->rx_dma_addr, DMA_RX_BUF_SIZE);
+	port->rx_dma_addr = 0;
+
+	rx_in = readl(uport->membase + SE_DMA_RX_LEN_IN);
+	if (!rx_in) {
+		dev_warn(uport->dev, "serial engine reports 0 RX bytes in!\n");
+		return;
+	}
+
+	if (!drop)
+		handle_rx_uart(uport, rx_in, drop);
+
+	ret = geni_se_rx_dma_prep(&port->se, port->rx_buf,
+				  DMA_RX_BUF_SIZE,
+				  &port->rx_dma_addr);
+	if (ret) {
+		dev_err(uport->dev, "unable to start RX SE DMA: %d\n", ret);
+		qcom_geni_serial_stop_rx_dma(uport);
+	}
+}
+
+static void qcom_geni_serial_start_rx(struct uart_port *uport)
+{
+	uport->ops->start_rx(uport);
+}
+
+static void qcom_geni_serial_stop_rx(struct uart_port *uport)
+{
+	uport->ops->stop_rx(uport);
+}
+
+static void qcom_geni_serial_stop_tx(struct uart_port *uport)
+{
+	uport->ops->stop_tx(uport);
+}
+
+static void qcom_geni_serial_send_chunk_fifo(struct uart_port *uport,
+					     unsigned int remaining)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	struct circ_buf *xmit = &uport->state->xmit;
+	unsigned int tx_bytes;
+	u8 buf[BYTES_PER_FIFO_WORD];
+
+	while (remaining) {
+		memset(buf, 0, sizeof(buf));
+		tx_bytes = min(remaining, BYTES_PER_FIFO_WORD);
+
+		memcpy(buf, &xmit->buf[xmit->tail], tx_bytes);
+		uart_xmit_advance(uport, tx_bytes);
+
+		iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
+
+		remaining -= tx_bytes;
+		port->tx_remaining -= tx_bytes;
+	}
+}
+
+static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport,
+					    bool done, bool active)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	struct circ_buf *xmit = &uport->state->xmit;
+	size_t avail;
+	size_t pending;
+	u32 status;
+	u32 irq_en;
+	unsigned int chunk;
+
+	status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
+
+	/* Complete the current tx command before taking newly added data */
+	if (active)
+		pending = port->tx_remaining;
+	else
+		pending = uart_circ_chars_pending(xmit);
+
+	/* All data has been transmitted and acknowledged as received */
+	if (!pending && !status && done) {
+		qcom_geni_serial_stop_tx_fifo(uport);
+		goto out_write_wakeup;
+	}
+
+	avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
+	avail *= BYTES_PER_FIFO_WORD;
+
+	chunk = min(avail, pending);
+	if (!chunk)
+		goto out_write_wakeup;
+
+	if (!port->tx_remaining) {
+		qcom_geni_serial_setup_tx(uport, pending);
+		port->tx_remaining = pending;
+
+		irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+		if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
+			writel(irq_en | M_TX_FIFO_WATERMARK_EN,
+					uport->membase + SE_GENI_M_IRQ_EN);
+	}
+
+	qcom_geni_serial_send_chunk_fifo(uport, chunk);
+
+	/*
+	 * The tx fifo watermark is level triggered and latched. Though we had
+	 * cleared it in qcom_geni_serial_isr it will have already reasserted
+	 * so we must clear it again here after our writes.
+	 */
+	writel(M_TX_FIFO_WATERMARK_EN,
+			uport->membase + SE_GENI_M_IRQ_CLEAR);
+
+out_write_wakeup:
+	if (!port->tx_remaining) {
+		irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+		if (irq_en & M_TX_FIFO_WATERMARK_EN)
+			writel(irq_en & ~M_TX_FIFO_WATERMARK_EN,
+					uport->membase + SE_GENI_M_IRQ_EN);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(uport);
+}
+
+static void qcom_geni_serial_handle_tx_dma(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	struct circ_buf *xmit = &uport->state->xmit;
+
+	uart_xmit_advance(uport, port->tx_remaining);
+	geni_se_tx_dma_unprep(&port->se, port->tx_dma_addr, port->tx_remaining);
+	port->tx_dma_addr = 0;
+	port->tx_remaining = 0;
+
+	if (!uart_circ_empty(xmit))
+		qcom_geni_serial_start_tx_dma(uport);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(uport);
+}
+
+static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
+{
+	u32 m_irq_en;
+	u32 m_irq_status;
+	u32 s_irq_status;
+	u32 geni_status;
+	u32 dma;
+	u32 dma_tx_status;
+	u32 dma_rx_status;
+	struct uart_port *uport = dev;
+	bool drop_rx = false;
+	struct tty_port *tport = &uport->state->port;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	if (uport->suspended)
+		return IRQ_NONE;
+
+	spin_lock(&uport->lock);
+
+	m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
+	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
+	dma_tx_status = readl(uport->membase + SE_DMA_TX_IRQ_STAT);
+	dma_rx_status = readl(uport->membase + SE_DMA_RX_IRQ_STAT);
+	geni_status = readl(uport->membase + SE_GENI_STATUS);
+	dma = readl(uport->membase + SE_GENI_DMA_MODE_EN);
+	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
+	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
+	writel(dma_tx_status, uport->membase + SE_DMA_TX_IRQ_CLR);
+	writel(dma_rx_status, uport->membase + SE_DMA_RX_IRQ_CLR);
+
+	if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
+		goto out_unlock;
+
+	if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
+		uport->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+	}
+
+	if (s_irq_status & (S_GP_IRQ_0_EN | S_GP_IRQ_1_EN)) {
+		if (s_irq_status & S_GP_IRQ_0_EN)
+			uport->icount.parity++;
+		drop_rx = true;
+	} else if (s_irq_status & (S_GP_IRQ_2_EN | S_GP_IRQ_3_EN)) {
+		uport->icount.brk++;
+		port->brk = true;
+	}
+
+	if (dma) {
+		if (dma_tx_status & TX_DMA_DONE)
+			qcom_geni_serial_handle_tx_dma(uport);
+
+		if (dma_rx_status) {
+			if (dma_rx_status & RX_RESET_DONE)
+				goto out_unlock;
+
+			if (dma_rx_status & RX_DMA_PARITY_ERR) {
+				uport->icount.parity++;
+				drop_rx = true;
+			}
+
+			if (dma_rx_status & RX_DMA_BREAK)
+				uport->icount.brk++;
+
+			if (dma_rx_status & (RX_DMA_DONE | RX_EOT))
+				qcom_geni_serial_handle_rx_dma(uport, drop_rx);
+		}
+	} else {
+		if (m_irq_status & m_irq_en &
+		    (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
+			qcom_geni_serial_handle_tx_fifo(uport,
+					m_irq_status & M_CMD_DONE_EN,
+					geni_status & M_GENI_CMD_ACTIVE);
+
+		if (s_irq_status & (S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN))
+			qcom_geni_serial_handle_rx_fifo(uport, drop_rx);
+	}
+
+out_unlock:
+	uart_unlock_and_check_sysrq(uport);
+
+	return IRQ_HANDLED;
+}
+
+static int setup_fifos(struct qcom_geni_serial_port *port)
+{
+	struct uart_port *uport;
+	u32 old_rx_fifo_depth = port->rx_fifo_depth;
+
+	uport = &port->uport;
+	port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
+	port->tx_fifo_width = geni_se_get_tx_fifo_width(&port->se);
+	port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
+	uport->fifosize =
+		(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
+
+	if (port->rx_buf && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
+		/*
+		 * Use krealloc rather than krealloc_array because rx_buf is
+		 * accessed as 1 byte entries as well as 4 byte entries so it's
+		 * not necessarily an array.
+		 */
+		port->rx_buf = devm_krealloc(uport->dev, port->rx_buf,
+					     port->rx_fifo_depth * sizeof(u32),
+					     GFP_KERNEL);
+		if (!port->rx_buf)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+
+static void qcom_geni_serial_shutdown(struct uart_port *uport)
+{
+	disable_irq(uport->irq);
+
+	if (uart_console(uport))
+		return;
+
+	qcom_geni_serial_stop_tx(uport);
+	qcom_geni_serial_stop_rx(uport);
+}
+
+static int qcom_geni_serial_port_setup(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
+	u32 proto;
+	u32 pin_swap;
+	int ret;
+
+	proto = geni_se_read_proto(&port->se);
+	if (proto != GENI_SE_UART) {
+		dev_err(uport->dev, "Invalid FW loaded, proto: %d\n", proto);
+		return -ENXIO;
+	}
+
+	qcom_geni_serial_stop_rx(uport);
+
+	ret = setup_fifos(port);
+	if (ret)
+		return ret;
+
+	writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
+
+	pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL);
+	if (port->rx_tx_swap) {
+		pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK;
+		pin_swap |= IO_MACRO_IO2_IO3_SWAP;
+	}
+	if (port->cts_rts_swap) {
+		pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK;
+		pin_swap |= IO_MACRO_IO0_SEL;
+	}
+	/* Configure this register if RX-TX, CTS-RTS pins are swapped */
+	if (port->rx_tx_swap || port->cts_rts_swap)
+		writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL);
+
+	/*
+	 * Make an unconditional cancel on the main sequencer to reset
+	 * it else we could end up in data loss scenarios.
+	 */
+	if (uart_console(uport))
+		qcom_geni_serial_poll_tx_done(uport);
+	geni_se_config_packing(&port->se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
+			       false, true, true);
+	geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
+	geni_se_select_mode(&port->se, port->dev_data->mode);
+	qcom_geni_serial_start_rx(uport);
+	port->setup = true;
+
+	return 0;
+}
+
+static int qcom_geni_serial_startup(struct uart_port *uport)
+{
+	int ret;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	if (!port->setup) {
+		ret = qcom_geni_serial_port_setup(uport);
+		if (ret)
+			return ret;
+	}
+	enable_irq(uport->irq);
+
+	return 0;
+}
+
+static unsigned long find_clk_rate_in_tol(struct clk *clk, unsigned int desired_clk,
+			unsigned int *clk_div, unsigned int percent_tol)
+{
+	unsigned long freq;
+	unsigned long div, maxdiv;
+	u64 mult;
+	unsigned long offset, abs_tol, achieved;
+
+	abs_tol = div_u64((u64)desired_clk * percent_tol, 100);
+	maxdiv = CLK_DIV_MSK >> CLK_DIV_SHFT;
+	div = 1;
+	while (div <= maxdiv) {
+		mult = (u64)div * desired_clk;
+		if (mult != (unsigned long)mult)
+			break;
+
+		offset = div * abs_tol;
+		freq = clk_round_rate(clk, mult - offset);
+
+		/* Can only get lower if we're done */
+		if (freq < mult - offset)
+			break;
+
+		/*
+		 * Re-calculate div in case rounding skipped rates but we
+		 * ended up at a good one, then check for a match.
+		 */
+		div = DIV_ROUND_CLOSEST(freq, desired_clk);
+		achieved = DIV_ROUND_CLOSEST(freq, div);
+		if (achieved <= desired_clk + abs_tol &&
+		    achieved >= desired_clk - abs_tol) {
+			*clk_div = div;
+			return freq;
+		}
+
+		div = DIV_ROUND_UP(freq, desired_clk);
+	}
+
+	return 0;
+}
+
+static unsigned long get_clk_div_rate(struct clk *clk, unsigned int baud,
+			unsigned int sampling_rate, unsigned int *clk_div)
+{
+	unsigned long ser_clk;
+	unsigned long desired_clk;
+
+	desired_clk = baud * sampling_rate;
+	if (!desired_clk)
+		return 0;
+
+	/*
+	 * try to find a clock rate within 2% tolerance, then within 5%
+	 */
+	ser_clk = find_clk_rate_in_tol(clk, desired_clk, clk_div, 2);
+	if (!ser_clk)
+		ser_clk = find_clk_rate_in_tol(clk, desired_clk, clk_div, 5);
+
+	return ser_clk;
+}
+
+static void qcom_geni_serial_set_termios(struct uart_port *uport,
+					 struct ktermios *termios,
+					 const struct ktermios *old)
+{
+	unsigned int baud;
+	u32 bits_per_char;
+	u32 tx_trans_cfg;
+	u32 tx_parity_cfg;
+	u32 rx_trans_cfg;
+	u32 rx_parity_cfg;
+	u32 stop_bit_len;
+	unsigned int clk_div;
+	u32 ser_clk_cfg;
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	unsigned long clk_rate;
+	u32 ver, sampling_rate;
+	unsigned int avg_bw_core;
+
+	qcom_geni_serial_stop_rx(uport);
+	/* baud rate */
+	baud = uart_get_baud_rate(uport, termios, old, 300, 4000000);
+	port->baud = baud;
+
+	sampling_rate = UART_OVERSAMPLING;
+	/* Sampling rate is halved for IP versions >= 2.5 */
+	ver = geni_se_get_qup_hw_version(&port->se);
+	if (ver >= QUP_SE_VERSION_2_5)
+		sampling_rate /= 2;
+
+	clk_rate = get_clk_div_rate(port->se.clk, baud,
+		sampling_rate, &clk_div);
+	if (!clk_rate) {
+		dev_err(port->se.dev,
+			"Couldn't find suitable clock rate for %u\n",
+			baud * sampling_rate);
+		goto out_restart_rx;
+	}
+
+	dev_dbg(port->se.dev, "desired_rate = %u, clk_rate = %lu, clk_div = %u\n",
+			baud * sampling_rate, clk_rate, clk_div);
+
+	uport->uartclk = clk_rate;
+	port->clk_rate = clk_rate;
+	dev_pm_opp_set_rate(uport->dev, clk_rate);
+	ser_clk_cfg = SER_CLK_EN;
+	ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
+
+	/*
+	 * Bump up BW vote on CPU and CORE path as driver supports FIFO mode
+	 * only.
+	 */
+	avg_bw_core = (baud > 115200) ? Bps_to_icc(CORE_2X_50_MHZ)
+						: GENI_DEFAULT_BW;
+	port->se.icc_paths[GENI_TO_CORE].avg_bw = avg_bw_core;
+	port->se.icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(baud);
+	geni_icc_set_bw(&port->se);
+
+	/* parity */
+	tx_trans_cfg = readl(uport->membase + SE_UART_TX_TRANS_CFG);
+	tx_parity_cfg = readl(uport->membase + SE_UART_TX_PARITY_CFG);
+	rx_trans_cfg = readl(uport->membase + SE_UART_RX_TRANS_CFG);
+	rx_parity_cfg = readl(uport->membase + SE_UART_RX_PARITY_CFG);
+	if (termios->c_cflag & PARENB) {
+		tx_trans_cfg |= UART_TX_PAR_EN;
+		rx_trans_cfg |= UART_RX_PAR_EN;
+		tx_parity_cfg |= PAR_CALC_EN;
+		rx_parity_cfg |= PAR_CALC_EN;
+		if (termios->c_cflag & PARODD) {
+			tx_parity_cfg |= PAR_ODD;
+			rx_parity_cfg |= PAR_ODD;
+		} else if (termios->c_cflag & CMSPAR) {
+			tx_parity_cfg |= PAR_SPACE;
+			rx_parity_cfg |= PAR_SPACE;
+		} else {
+			tx_parity_cfg |= PAR_EVEN;
+			rx_parity_cfg |= PAR_EVEN;
+		}
+	} else {
+		tx_trans_cfg &= ~UART_TX_PAR_EN;
+		rx_trans_cfg &= ~UART_RX_PAR_EN;
+		tx_parity_cfg &= ~PAR_CALC_EN;
+		rx_parity_cfg &= ~PAR_CALC_EN;
+	}
+
+	/* bits per char */
+	bits_per_char = tty_get_char_size(termios->c_cflag);
+
+	/* stop bits */
+	if (termios->c_cflag & CSTOPB)
+		stop_bit_len = TX_STOP_BIT_LEN_2;
+	else
+		stop_bit_len = TX_STOP_BIT_LEN_1;
+
+	/* flow control, clear the CTS_MASK bit if using flow control. */
+	if (termios->c_cflag & CRTSCTS)
+		tx_trans_cfg &= ~UART_CTS_MASK;
+	else
+		tx_trans_cfg |= UART_CTS_MASK;
+
+	if (baud)
+		uart_update_timeout(uport, termios->c_cflag, baud);
+
+	if (!uart_console(uport))
+		writel(port->loopback,
+				uport->membase + SE_UART_LOOPBACK_CFG);
+	writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
+	writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
+	writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
+	writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
+	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
+	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
+	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
+	writel(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG);
+	writel(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG);
+out_restart_rx:
+	qcom_geni_serial_start_rx(uport);
+}
+
+#ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
+static int qcom_geni_console_setup(struct console *co, char *options)
+{
+	struct uart_port *uport;
+	struct qcom_geni_serial_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	if (co->index >= GENI_UART_CONS_PORTS  || co->index < 0)
+		return -ENXIO;
+
+	port = get_port_from_line(co->index, true);
+	if (IS_ERR(port)) {
+		pr_err("Invalid line %d\n", co->index);
+		return PTR_ERR(port);
+	}
+
+	uport = &port->uport;
+
+	if (unlikely(!uport->membase))
+		return -ENXIO;
+
+	if (!port->setup) {
+		ret = qcom_geni_serial_port_setup(uport);
+		if (ret)
+			return ret;
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(uport, co, baud, parity, bits, flow);
+}
+
+static void qcom_geni_serial_earlycon_write(struct console *con,
+					const char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	__qcom_geni_serial_console_write(&dev->port, s, n);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int qcom_geni_serial_earlycon_read(struct console *con,
+					  char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+	struct uart_port *uport = &dev->port;
+	int num_read = 0;
+	int ch;
+
+	while (num_read < n) {
+		ch = qcom_geni_serial_get_char(uport);
+		if (ch == NO_POLL_CHAR)
+			break;
+		s[num_read++] = ch;
+	}
+
+	return num_read;
+}
+
+static void __init qcom_geni_serial_enable_early_read(struct geni_se *se,
+						      struct console *con)
+{
+	geni_se_setup_s_cmd(se, UART_START_READ, 0);
+	con->read = qcom_geni_serial_earlycon_read;
+}
+#else
+static inline void qcom_geni_serial_enable_early_read(struct geni_se *se,
+						      struct console *con) { }
+#endif
+
+static struct qcom_geni_private_data earlycon_private_data;
+
+static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev,
+								const char *opt)
+{
+	struct uart_port *uport = &dev->port;
+	u32 tx_trans_cfg;
+	u32 tx_parity_cfg = 0;	/* Disable Tx Parity */
+	u32 rx_trans_cfg = 0;
+	u32 rx_parity_cfg = 0;	/* Disable Rx Parity */
+	u32 stop_bit_len = 0;	/* Default stop bit length - 1 bit */
+	u32 bits_per_char;
+	struct geni_se se;
+
+	if (!uport->membase)
+		return -EINVAL;
+
+	uport->private_data = &earlycon_private_data;
+
+	memset(&se, 0, sizeof(se));
+	se.base = uport->membase;
+	if (geni_se_read_proto(&se) != GENI_SE_UART)
+		return -ENXIO;
+	/*
+	 * Ignore Flow control.
+	 * n = 8.
+	 */
+	tx_trans_cfg = UART_CTS_MASK;
+	bits_per_char = BITS_PER_BYTE;
+
+	/*
+	 * Make an unconditional cancel on the main sequencer to reset
+	 * it else we could end up in data loss scenarios.
+	 */
+	qcom_geni_serial_poll_tx_done(uport);
+	qcom_geni_serial_abort_rx(uport);
+	geni_se_config_packing(&se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
+			       false, true, true);
+	geni_se_init(&se, DEF_FIFO_DEPTH_WORDS / 2, DEF_FIFO_DEPTH_WORDS - 2);
+	geni_se_select_mode(&se, GENI_SE_FIFO);
+
+	writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
+	writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
+	writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
+	writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
+	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
+	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
+	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
+
+	dev->con->write = qcom_geni_serial_earlycon_write;
+	dev->con->setup = NULL;
+	qcom_geni_serial_enable_early_read(&se, dev->con);
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",
+				qcom_geni_serial_earlycon_setup);
+
+static int __init console_register(struct uart_driver *drv)
+{
+	return uart_register_driver(drv);
+}
+
+static void console_unregister(struct uart_driver *drv)
+{
+	uart_unregister_driver(drv);
+}
+
+static struct console cons_ops = {
+	.name = "ttyMSM",
+	.write = qcom_geni_serial_console_write,
+	.device = uart_console_device,
+	.setup = qcom_geni_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &qcom_geni_console_driver,
+};
+
+static struct uart_driver qcom_geni_console_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "qcom_geni_console",
+	.dev_name = "ttyMSM",
+	.nr =  GENI_UART_CONS_PORTS,
+	.cons = &cons_ops,
+};
+#else
+static int console_register(struct uart_driver *drv)
+{
+	return 0;
+}
+
+static void console_unregister(struct uart_driver *drv)
+{
+}
+#endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
+
+static struct uart_driver qcom_geni_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "qcom_geni_uart",
+	.dev_name = "ttyHS",
+	.nr =  GENI_UART_PORTS,
+};
+
+static void qcom_geni_serial_pm(struct uart_port *uport,
+		unsigned int new_state, unsigned int old_state)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+	/* If we've never been called, treat it as off */
+	if (old_state == UART_PM_STATE_UNDEFINED)
+		old_state = UART_PM_STATE_OFF;
+
+	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF) {
+		geni_icc_enable(&port->se);
+		if (port->clk_rate)
+			dev_pm_opp_set_rate(uport->dev, port->clk_rate);
+		geni_se_resources_on(&port->se);
+	} else if (new_state == UART_PM_STATE_OFF &&
+			old_state == UART_PM_STATE_ON) {
+		geni_se_resources_off(&port->se);
+		dev_pm_opp_set_rate(uport->dev, 0);
+		geni_icc_disable(&port->se);
+	}
+}
+
+static const struct uart_ops qcom_geni_console_pops = {
+	.tx_empty = qcom_geni_serial_tx_empty,
+	.stop_tx = qcom_geni_serial_stop_tx_fifo,
+	.start_tx = qcom_geni_serial_start_tx_fifo,
+	.stop_rx = qcom_geni_serial_stop_rx_fifo,
+	.start_rx = qcom_geni_serial_start_rx_fifo,
+	.set_termios = qcom_geni_serial_set_termios,
+	.startup = qcom_geni_serial_startup,
+	.request_port = qcom_geni_serial_request_port,
+	.config_port = qcom_geni_serial_config_port,
+	.shutdown = qcom_geni_serial_shutdown,
+	.type = qcom_geni_serial_get_type,
+	.set_mctrl = qcom_geni_serial_set_mctrl,
+	.get_mctrl = qcom_geni_serial_get_mctrl,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= qcom_geni_serial_get_char,
+	.poll_put_char	= qcom_geni_serial_poll_put_char,
+	.poll_init = qcom_geni_serial_port_setup,
+#endif
+	.pm = qcom_geni_serial_pm,
+};
+
+static const struct uart_ops qcom_geni_uart_pops = {
+	.tx_empty = qcom_geni_serial_tx_empty,
+	.stop_tx = qcom_geni_serial_stop_tx_dma,
+	.start_tx = qcom_geni_serial_start_tx_dma,
+	.start_rx = qcom_geni_serial_start_rx_dma,
+	.stop_rx = qcom_geni_serial_stop_rx_dma,
+	.set_termios = qcom_geni_serial_set_termios,
+	.startup = qcom_geni_serial_startup,
+	.request_port = qcom_geni_serial_request_port,
+	.config_port = qcom_geni_serial_config_port,
+	.shutdown = qcom_geni_serial_shutdown,
+	.type = qcom_geni_serial_get_type,
+	.set_mctrl = qcom_geni_serial_set_mctrl,
+	.get_mctrl = qcom_geni_serial_get_mctrl,
+	.pm = qcom_geni_serial_pm,
+};
+
+static int qcom_geni_serial_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	int line;
+	struct qcom_geni_serial_port *port;
+	struct uart_port *uport;
+	struct resource *res;
+	int irq;
+	struct uart_driver *drv;
+	const struct qcom_geni_device_data *data;
+
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
+		return -EINVAL;
+
+	if (data->console) {
+		drv = &qcom_geni_console_driver;
+		line = of_alias_get_id(pdev->dev.of_node, "serial");
+	} else {
+		drv = &qcom_geni_uart_driver;
+		line = of_alias_get_id(pdev->dev.of_node, "serial");
+		if (line == -ENODEV) /* compat with non-standard aliases */
+			line = of_alias_get_id(pdev->dev.of_node, "hsuart");
+	}
+
+	port = get_port_from_line(line, data->console);
+	if (IS_ERR(port)) {
+		dev_err(&pdev->dev, "Invalid line %d\n", line);
+		return PTR_ERR(port);
+	}
+
+	uport = &port->uport;
+	/* Don't allow 2 drivers to access the same port */
+	if (uport->private_data)
+		return -ENODEV;
+
+	uport->dev = &pdev->dev;
+	port->dev_data = data;
+	port->se.dev = &pdev->dev;
+	port->se.wrapper = dev_get_drvdata(pdev->dev.parent);
+	port->se.clk = devm_clk_get(&pdev->dev, "se");
+	if (IS_ERR(port->se.clk)) {
+		ret = PTR_ERR(port->se.clk);
+		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
+		return ret;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+	uport->mapbase = res->start;
+
+	port->tx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
+	port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
+	port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
+
+	if (!data->console) {
+		port->rx_buf = devm_kzalloc(uport->dev,
+					    DMA_RX_BUF_SIZE, GFP_KERNEL);
+		if (!port->rx_buf)
+			return -ENOMEM;
+	}
+
+	ret = geni_icc_get(&port->se, NULL);
+	if (ret)
+		return ret;
+	port->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
+	port->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
+
+	/* Set BW for register access */
+	ret = geni_icc_set_bw(&port->se);
+	if (ret)
+		return ret;
+
+	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
+			"qcom_geni_serial_%s%d",
+			uart_console(uport) ? "console" : "uart", uport->line);
+	if (!port->name)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	uport->irq = irq;
+	uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE);
+
+	if (!data->console)
+		port->wakeup_irq = platform_get_irq_optional(pdev, 1);
+
+	if (of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"))
+		port->rx_tx_swap = true;
+
+	if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
+		port->cts_rts_swap = true;
+
+	ret = devm_pm_opp_set_clkname(&pdev->dev, "se");
+	if (ret)
+		return ret;
+	/* OPP table is optional */
+	ret = devm_pm_opp_of_add_table(&pdev->dev);
+	if (ret && ret != -ENODEV) {
+		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
+		return ret;
+	}
+
+	port->private_data.drv = drv;
+	uport->private_data = &port->private_data;
+	platform_set_drvdata(pdev, port);
+
+	irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
+	ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
+			IRQF_TRIGGER_HIGH, port->name, uport);
+	if (ret) {
+		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
+		return ret;
+	}
+
+	ret = uart_add_one_port(drv, uport);
+	if (ret)
+		return ret;
+
+	if (port->wakeup_irq > 0) {
+		device_init_wakeup(&pdev->dev, true);
+		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
+						port->wakeup_irq);
+		if (ret) {
+			device_init_wakeup(&pdev->dev, false);
+			uart_remove_one_port(drv, uport);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int qcom_geni_serial_remove(struct platform_device *pdev)
+{
+	struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
+	struct uart_driver *drv = port->private_data.drv;
+
+	dev_pm_clear_wake_irq(&pdev->dev);
+	device_init_wakeup(&pdev->dev, false);
+	uart_remove_one_port(drv, &port->uport);
+
+	return 0;
+}
+
+static int qcom_geni_serial_sys_suspend(struct device *dev)
+{
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
+	struct uart_port *uport = &port->uport;
+	struct qcom_geni_private_data *private_data = uport->private_data;
+
+	/*
+	 * This is done so we can hit the lowest possible state in suspend
+	 * even with no_console_suspend
+	 */
+	if (uart_console(uport)) {
+		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ACTIVE_ONLY);
+		geni_icc_set_bw(&port->se);
+	}
+	return uart_suspend_port(private_data->drv, uport);
+}
+
+static int qcom_geni_serial_sys_resume(struct device *dev)
+{
+	int ret;
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
+	struct uart_port *uport = &port->uport;
+	struct qcom_geni_private_data *private_data = uport->private_data;
+
+	ret = uart_resume_port(private_data->drv, uport);
+	if (uart_console(uport)) {
+		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);
+		geni_icc_set_bw(&port->se);
+	}
+	return ret;
+}
+
+static int qcom_geni_serial_sys_hib_resume(struct device *dev)
+{
+	int ret = 0;
+	struct uart_port *uport;
+	struct qcom_geni_private_data *private_data;
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
+
+	uport = &port->uport;
+	private_data = uport->private_data;
+
+	if (uart_console(uport)) {
+		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);
+		geni_icc_set_bw(&port->se);
+		ret = uart_resume_port(private_data->drv, uport);
+		/*
+		 * For hibernation usecase clients for
+		 * console UART won't call port setup during restore,
+		 * hence call port setup for console uart.
+		 */
+		qcom_geni_serial_port_setup(uport);
+	} else {
+		/*
+		 * Peripheral register settings are lost during hibernation.
+		 * Update setup flag such that port setup happens again
+		 * during next session. Clients of HS-UART will close and
+		 * open the port during hibernation.
+		 */
+		port->setup = false;
+	}
+	return ret;
+}
+
+static const struct qcom_geni_device_data qcom_geni_console_data = {
+	.console = true,
+	.mode = GENI_SE_FIFO,
+};
+
+static const struct qcom_geni_device_data qcom_geni_uart_data = {
+	.console = false,
+	.mode = GENI_SE_DMA,
+};
+
+static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
+	.suspend = pm_sleep_ptr(qcom_geni_serial_sys_suspend),
+	.resume = pm_sleep_ptr(qcom_geni_serial_sys_resume),
+	.freeze = pm_sleep_ptr(qcom_geni_serial_sys_suspend),
+	.poweroff = pm_sleep_ptr(qcom_geni_serial_sys_suspend),
+	.restore = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume),
+	.thaw = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume),
+};
+
+static const struct of_device_id qcom_geni_serial_match_table[] = {
+	{
+		.compatible = "qcom,geni-debug-uart",
+		.data = &qcom_geni_console_data,
+	},
+	{
+		.compatible = "qcom,geni-uart",
+		.data = &qcom_geni_uart_data,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_geni_serial_match_table);
+
+static struct platform_driver qcom_geni_serial_platform_driver = {
+	.remove = qcom_geni_serial_remove,
+	.probe = qcom_geni_serial_probe,
+	.driver = {
+		.name = "qcom_geni_serial",
+		.of_match_table = qcom_geni_serial_match_table,
+		.pm = &qcom_geni_serial_pm_ops,
+	},
+};
+
+static int __init qcom_geni_serial_init(void)
+{
+	int ret;
+
+	ret = console_register(&qcom_geni_console_driver);
+	if (ret)
+		return ret;
+
+	ret = uart_register_driver(&qcom_geni_uart_driver);
+	if (ret) {
+		console_unregister(&qcom_geni_console_driver);
+		return ret;
+	}
+
+	ret = platform_driver_register(&qcom_geni_serial_platform_driver);
+	if (ret) {
+		console_unregister(&qcom_geni_console_driver);
+		uart_unregister_driver(&qcom_geni_uart_driver);
+	}
+	return ret;
+}
+module_init(qcom_geni_serial_init);
+
+static void __exit qcom_geni_serial_exit(void)
+{
+	platform_driver_unregister(&qcom_geni_serial_platform_driver);
+	console_unregister(&qcom_geni_console_driver);
+	uart_unregister_driver(&qcom_geni_uart_driver);
+}
+module_exit(qcom_geni_serial_exit);
+
+MODULE_DESCRIPTION("Serial driver for GENI based QUP cores");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c
new file mode 100644
index 000000000..be5c842b5
--- /dev/null
+++ b/drivers/tty/serial/rda-uart.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RDA8810PL serial device driver
+ *
+ * Copyright RDA Microelectronics Company Limited
+ * Copyright (c) 2017 Andreas Färber
+ * Copyright (c) 2018 Manivannan Sadhasivam
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define RDA_UART_PORT_NUM 3
+#define RDA_UART_DEV_NAME "ttyRDA"
+
+#define RDA_UART_CTRL		0x00
+#define RDA_UART_STATUS		0x04
+#define RDA_UART_RXTX_BUFFER	0x08
+#define RDA_UART_IRQ_MASK	0x0c
+#define RDA_UART_IRQ_CAUSE	0x10
+#define RDA_UART_IRQ_TRIGGERS	0x14
+#define RDA_UART_CMD_SET	0x18
+#define RDA_UART_CMD_CLR	0x1c
+
+/* UART_CTRL Bits */
+#define RDA_UART_ENABLE			BIT(0)
+#define RDA_UART_DBITS_8		BIT(1)
+#define RDA_UART_TX_SBITS_2		BIT(2)
+#define RDA_UART_PARITY_EN		BIT(3)
+#define RDA_UART_PARITY(x)		(((x) & 0x3) << 4)
+#define RDA_UART_PARITY_ODD		RDA_UART_PARITY(0)
+#define RDA_UART_PARITY_EVEN		RDA_UART_PARITY(1)
+#define RDA_UART_PARITY_SPACE		RDA_UART_PARITY(2)
+#define RDA_UART_PARITY_MARK		RDA_UART_PARITY(3)
+#define RDA_UART_DIV_MODE		BIT(20)
+#define RDA_UART_IRDA_EN		BIT(21)
+#define RDA_UART_DMA_EN			BIT(22)
+#define RDA_UART_FLOW_CNT_EN		BIT(23)
+#define RDA_UART_LOOP_BACK_EN		BIT(24)
+#define RDA_UART_RX_LOCK_ERR		BIT(25)
+#define RDA_UART_RX_BREAK_LEN(x)	(((x) & 0xf) << 28)
+
+/* UART_STATUS Bits */
+#define RDA_UART_RX_FIFO(x)		(((x) & 0x7f) << 0)
+#define RDA_UART_RX_FIFO_MASK		(0x7f << 0)
+#define RDA_UART_TX_FIFO(x)		(((x) & 0x1f) << 8)
+#define RDA_UART_TX_FIFO_MASK		(0x1f << 8)
+#define RDA_UART_TX_ACTIVE		BIT(14)
+#define RDA_UART_RX_ACTIVE		BIT(15)
+#define RDA_UART_RX_OVERFLOW_ERR	BIT(16)
+#define RDA_UART_TX_OVERFLOW_ERR	BIT(17)
+#define RDA_UART_RX_PARITY_ERR		BIT(18)
+#define RDA_UART_RX_FRAMING_ERR		BIT(19)
+#define RDA_UART_RX_BREAK_INT		BIT(20)
+#define RDA_UART_DCTS			BIT(24)
+#define RDA_UART_CTS			BIT(25)
+#define RDA_UART_DTR			BIT(28)
+#define RDA_UART_CLK_ENABLED		BIT(31)
+
+/* UART_RXTX_BUFFER Bits */
+#define RDA_UART_RX_DATA(x)		(((x) & 0xff) << 0)
+#define RDA_UART_TX_DATA(x)		(((x) & 0xff) << 0)
+
+/* UART_IRQ_MASK Bits */
+#define RDA_UART_TX_MODEM_STATUS	BIT(0)
+#define RDA_UART_RX_DATA_AVAILABLE	BIT(1)
+#define RDA_UART_TX_DATA_NEEDED		BIT(2)
+#define RDA_UART_RX_TIMEOUT		BIT(3)
+#define RDA_UART_RX_LINE_ERR		BIT(4)
+#define RDA_UART_TX_DMA_DONE		BIT(5)
+#define RDA_UART_RX_DMA_DONE		BIT(6)
+#define RDA_UART_RX_DMA_TIMEOUT		BIT(7)
+#define RDA_UART_DTR_RISE		BIT(8)
+#define RDA_UART_DTR_FALL		BIT(9)
+
+/* UART_IRQ_CAUSE Bits */
+#define RDA_UART_TX_MODEM_STATUS_U	BIT(16)
+#define RDA_UART_RX_DATA_AVAILABLE_U	BIT(17)
+#define RDA_UART_TX_DATA_NEEDED_U	BIT(18)
+#define RDA_UART_RX_TIMEOUT_U		BIT(19)
+#define RDA_UART_RX_LINE_ERR_U		BIT(20)
+#define RDA_UART_TX_DMA_DONE_U		BIT(21)
+#define RDA_UART_RX_DMA_DONE_U		BIT(22)
+#define RDA_UART_RX_DMA_TIMEOUT_U	BIT(23)
+#define RDA_UART_DTR_RISE_U		BIT(24)
+#define RDA_UART_DTR_FALL_U		BIT(25)
+
+/* UART_TRIGGERS Bits */
+#define RDA_UART_RX_TRIGGER(x)		(((x) & 0x1f) << 0)
+#define RDA_UART_TX_TRIGGER(x)		(((x) & 0xf) << 8)
+#define RDA_UART_AFC_LEVEL(x)		(((x) & 0x1f) << 16)
+
+/* UART_CMD_SET Bits */
+#define RDA_UART_RI			BIT(0)
+#define RDA_UART_DCD			BIT(1)
+#define RDA_UART_DSR			BIT(2)
+#define RDA_UART_TX_BREAK_CONTROL	BIT(3)
+#define RDA_UART_TX_FINISH_N_WAIT	BIT(4)
+#define RDA_UART_RTS			BIT(5)
+#define RDA_UART_RX_FIFO_RESET		BIT(6)
+#define RDA_UART_TX_FIFO_RESET		BIT(7)
+
+#define RDA_UART_TX_FIFO_SIZE	16
+
+static struct uart_driver rda_uart_driver;
+
+struct rda_uart_port {
+	struct uart_port port;
+	struct clk *clk;
+};
+
+#define to_rda_uart_port(port) container_of(port, struct rda_uart_port, port)
+
+static struct rda_uart_port *rda_uart_ports[RDA_UART_PORT_NUM];
+
+static inline void rda_uart_write(struct uart_port *port, u32 val,
+				  unsigned int off)
+{
+	writel(val, port->membase + off);
+}
+
+static inline u32 rda_uart_read(struct uart_port *port, unsigned int off)
+{
+	return readl(port->membase + off);
+}
+
+static unsigned int rda_uart_tx_empty(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned int ret;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = rda_uart_read(port, RDA_UART_STATUS);
+	ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return ret;
+}
+
+static unsigned int rda_uart_get_mctrl(struct uart_port *port)
+{
+	unsigned int mctrl = 0;
+	u32 cmd_set, status;
+
+	cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
+	status = rda_uart_read(port, RDA_UART_STATUS);
+	if (cmd_set & RDA_UART_RTS)
+		mctrl |= TIOCM_RTS;
+	if (!(status & RDA_UART_CTS))
+		mctrl |= TIOCM_CTS;
+
+	return mctrl;
+}
+
+static void rda_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 val;
+
+	if (mctrl & TIOCM_RTS) {
+		val = rda_uart_read(port, RDA_UART_CMD_SET);
+		rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_SET);
+	} else {
+		/* Clear RTS to stop to receive. */
+		val = rda_uart_read(port, RDA_UART_CMD_CLR);
+		rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_CLR);
+	}
+
+	val = rda_uart_read(port, RDA_UART_CTRL);
+
+	if (mctrl & TIOCM_LOOP)
+		val |= RDA_UART_LOOP_BACK_EN;
+	else
+		val &= ~RDA_UART_LOOP_BACK_EN;
+
+	rda_uart_write(port, val, RDA_UART_CTRL);
+}
+
+static void rda_uart_stop_tx(struct uart_port *port)
+{
+	u32 val;
+
+	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+	val &= ~RDA_UART_TX_DATA_NEEDED;
+	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+
+	val = rda_uart_read(port, RDA_UART_CMD_SET);
+	val |= RDA_UART_TX_FIFO_RESET;
+	rda_uart_write(port, val, RDA_UART_CMD_SET);
+}
+
+static void rda_uart_stop_rx(struct uart_port *port)
+{
+	u32 val;
+
+	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+	val &= ~(RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
+	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+
+	/* Read Rx buffer before reset to avoid Rx timeout interrupt */
+	val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
+
+	val = rda_uart_read(port, RDA_UART_CMD_SET);
+	val |= RDA_UART_RX_FIFO_RESET;
+	rda_uart_write(port, val, RDA_UART_CMD_SET);
+}
+
+static void rda_uart_start_tx(struct uart_port *port)
+{
+	u32 val;
+
+	if (uart_tx_stopped(port)) {
+		rda_uart_stop_tx(port);
+		return;
+	}
+
+	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+	val |= RDA_UART_TX_DATA_NEEDED;
+	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+}
+
+static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
+				     unsigned long baud)
+{
+	clk_set_rate(rda_port->clk, baud * 8);
+}
+
+static void rda_uart_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	struct rda_uart_port *rda_port = to_rda_uart_port(port);
+	unsigned long flags;
+	unsigned int ctrl, cmd_set, cmd_clr, triggers;
+	unsigned int baud;
+	u32 irq_mask;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
+	rda_uart_change_baudrate(rda_port, baud);
+
+	ctrl = rda_uart_read(port, RDA_UART_CTRL);
+	cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
+	cmd_clr = rda_uart_read(port, RDA_UART_CMD_CLR);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+	case CS6:
+		dev_warn(port->dev, "bit size not supported, using 7 bits\n");
+		fallthrough;
+	case CS7:
+		ctrl &= ~RDA_UART_DBITS_8;
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS7;
+		break;
+	default:
+		ctrl |= RDA_UART_DBITS_8;
+		break;
+	}
+
+	/* stop bits */
+	if (termios->c_cflag & CSTOPB)
+		ctrl |= RDA_UART_TX_SBITS_2;
+	else
+		ctrl &= ~RDA_UART_TX_SBITS_2;
+
+	/* parity check */
+	if (termios->c_cflag & PARENB) {
+		ctrl |= RDA_UART_PARITY_EN;
+
+		/* Mark or Space parity */
+		if (termios->c_cflag & CMSPAR) {
+			if (termios->c_cflag & PARODD)
+				ctrl |= RDA_UART_PARITY_MARK;
+			else
+				ctrl |= RDA_UART_PARITY_SPACE;
+		} else if (termios->c_cflag & PARODD) {
+			ctrl |= RDA_UART_PARITY_ODD;
+		} else {
+			ctrl |= RDA_UART_PARITY_EVEN;
+		}
+	} else {
+		ctrl &= ~RDA_UART_PARITY_EN;
+	}
+
+	/* Hardware handshake (RTS/CTS) */
+	if (termios->c_cflag & CRTSCTS) {
+		ctrl   |= RDA_UART_FLOW_CNT_EN;
+		cmd_set |= RDA_UART_RTS;
+	} else {
+		ctrl   &= ~RDA_UART_FLOW_CNT_EN;
+		cmd_clr |= RDA_UART_RTS;
+	}
+
+	ctrl |= RDA_UART_ENABLE;
+	ctrl &= ~RDA_UART_DMA_EN;
+
+	triggers  = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
+	irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
+	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+
+	rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
+	rda_uart_write(port, ctrl, RDA_UART_CTRL);
+	rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
+	rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
+
+	rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void rda_uart_send_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int ch;
+	u32 val;
+
+	if (uart_tx_stopped(port))
+		return;
+
+	if (port->x_char) {
+		while (!(rda_uart_read(port, RDA_UART_STATUS) &
+			 RDA_UART_TX_FIFO_MASK))
+			cpu_relax();
+
+		rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
+		port->icount.tx++;
+		port->x_char = 0;
+	}
+
+	while (rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) {
+		if (uart_circ_empty(xmit))
+			break;
+
+		ch = xmit->buf[xmit->tail];
+		rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
+		uart_xmit_advance(port, 1);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (!uart_circ_empty(xmit)) {
+		/* Re-enable Tx FIFO interrupt */
+		val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+		val |= RDA_UART_TX_DATA_NEEDED;
+		rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+	}
+}
+
+static void rda_uart_receive_chars(struct uart_port *port)
+{
+	u32 status, val;
+
+	status = rda_uart_read(port, RDA_UART_STATUS);
+	while ((status & RDA_UART_RX_FIFO_MASK)) {
+		char flag = TTY_NORMAL;
+
+		if (status & RDA_UART_RX_PARITY_ERR) {
+			port->icount.parity++;
+			flag = TTY_PARITY;
+		}
+
+		if (status & RDA_UART_RX_FRAMING_ERR) {
+			port->icount.frame++;
+			flag = TTY_FRAME;
+		}
+
+		if (status & RDA_UART_RX_OVERFLOW_ERR) {
+			port->icount.overrun++;
+			flag = TTY_OVERRUN;
+		}
+
+		val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
+		val &= 0xff;
+
+		port->icount.rx++;
+		tty_insert_flip_char(&port->state->port, val, flag);
+
+		status = rda_uart_read(port, RDA_UART_STATUS);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static irqreturn_t rda_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned long flags;
+	u32 val, irq_mask;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Clear IRQ cause */
+	val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
+	rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
+
+	if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
+		rda_uart_receive_chars(port);
+
+	if (val & (RDA_UART_TX_DATA_NEEDED)) {
+		irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
+		irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
+		rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
+
+		rda_uart_send_chars(port);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static int rda_uart_startup(struct uart_port *port)
+{
+	unsigned long flags;
+	int ret;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
+			  "rda-uart", port);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = rda_uart_read(port, RDA_UART_CTRL);
+	val |= RDA_UART_ENABLE;
+	rda_uart_write(port, val, RDA_UART_CTRL);
+
+	/* enable rx interrupt */
+	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+	val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
+	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void rda_uart_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	rda_uart_stop_tx(port);
+	rda_uart_stop_rx(port);
+
+	val = rda_uart_read(port, RDA_UART_CTRL);
+	val &= ~RDA_UART_ENABLE;
+	rda_uart_write(port, val, RDA_UART_CTRL);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *rda_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_RDA) ? "rda-uart" : NULL;
+}
+
+static int rda_uart_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENXIO;
+
+	if (!devm_request_mem_region(port->dev, port->mapbase,
+				     resource_size(res), dev_name(port->dev)))
+		return -EBUSY;
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = devm_ioremap(port->dev, port->mapbase,
+						     resource_size(res));
+		if (!port->membase)
+			return -EBUSY;
+	}
+
+	return 0;
+}
+
+static void rda_uart_config_port(struct uart_port *port, int flags)
+{
+	unsigned long irq_flags;
+
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_RDA;
+		rda_uart_request_port(port);
+	}
+
+	spin_lock_irqsave(&port->lock, irq_flags);
+
+	/* Clear mask, so no surprise interrupts. */
+	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+
+	/* Clear status register */
+	rda_uart_write(port, 0, RDA_UART_STATUS);
+
+	spin_unlock_irqrestore(&port->lock, irq_flags);
+}
+
+static void rda_uart_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return;
+
+	if (port->flags & UPF_IOREMAP) {
+		devm_release_mem_region(port->dev, port->mapbase,
+					resource_size(res));
+		devm_iounmap(port->dev, port->membase);
+		port->membase = NULL;
+	}
+}
+
+static int rda_uart_verify_port(struct uart_port *port,
+				struct serial_struct *ser)
+{
+	if (port->type != PORT_RDA)
+		return -EINVAL;
+
+	if (port->irq != ser->irq)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops rda_uart_ops = {
+	.tx_empty       = rda_uart_tx_empty,
+	.get_mctrl      = rda_uart_get_mctrl,
+	.set_mctrl      = rda_uart_set_mctrl,
+	.start_tx       = rda_uart_start_tx,
+	.stop_tx        = rda_uart_stop_tx,
+	.stop_rx        = rda_uart_stop_rx,
+	.startup        = rda_uart_startup,
+	.shutdown       = rda_uart_shutdown,
+	.set_termios    = rda_uart_set_termios,
+	.type           = rda_uart_type,
+	.request_port	= rda_uart_request_port,
+	.release_port	= rda_uart_release_port,
+	.config_port	= rda_uart_config_port,
+	.verify_port	= rda_uart_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_RDA_CONSOLE
+
+static void rda_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	if (!port->membase)
+		return;
+
+	while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
+		cpu_relax();
+
+	rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
+}
+
+static void rda_uart_port_write(struct uart_port *port, const char *s,
+				u_int count)
+{
+	u32 old_irq_mask;
+	unsigned long flags;
+	int locked;
+
+	local_irq_save(flags);
+
+	if (port->sysrq) {
+		locked = 0;
+	} else if (oops_in_progress) {
+		locked = spin_trylock(&port->lock);
+	} else {
+		spin_lock(&port->lock);
+		locked = 1;
+	}
+
+	old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
+	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+
+	uart_console_write(port, s, count, rda_console_putchar);
+
+	/* wait until all contents have been sent out */
+	while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
+		cpu_relax();
+
+	rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
+
+	if (locked)
+		spin_unlock(&port->lock);
+
+	local_irq_restore(flags);
+}
+
+static void rda_uart_console_write(struct console *co, const char *s,
+				   u_int count)
+{
+	struct rda_uart_port *rda_port;
+
+	rda_port = rda_uart_ports[co->index];
+	if (!rda_port)
+		return;
+
+	rda_uart_port_write(&rda_port->port, s, count);
+}
+
+static int rda_uart_console_setup(struct console *co, char *options)
+{
+	struct rda_uart_port *rda_port;
+	int baud = 921600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
+		return -EINVAL;
+
+	rda_port = rda_uart_ports[co->index];
+	if (!rda_port || !rda_port->port.membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
+}
+
+static struct console rda_uart_console = {
+	.name = RDA_UART_DEV_NAME,
+	.write = rda_uart_console_write,
+	.device = uart_console_device,
+	.setup = rda_uart_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &rda_uart_driver,
+};
+
+static int __init rda_uart_console_init(void)
+{
+	register_console(&rda_uart_console);
+
+	return 0;
+}
+console_initcall(rda_uart_console_init);
+
+static void rda_uart_early_console_write(struct console *co,
+					 const char *s,
+					 u_int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	rda_uart_port_write(&dev->port, s, count);
+}
+
+static int __init
+rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = rda_uart_early_console_write;
+
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
+		    rda_uart_early_console_setup);
+
+#define RDA_UART_CONSOLE (&rda_uart_console)
+#else
+#define RDA_UART_CONSOLE NULL
+#endif /* CONFIG_SERIAL_RDA_CONSOLE */
+
+static struct uart_driver rda_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "rda-uart",
+	.dev_name = RDA_UART_DEV_NAME,
+	.nr = RDA_UART_PORT_NUM,
+	.cons = RDA_UART_CONSOLE,
+};
+
+static const struct of_device_id rda_uart_dt_matches[] = {
+	{ .compatible = "rda,8810pl-uart" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
+
+static int rda_uart_probe(struct platform_device *pdev)
+{
+	struct resource *res_mem;
+	struct rda_uart_port *rda_port;
+	int ret, irq;
+
+	if (pdev->dev.of_node)
+		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+
+	if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
+		dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
+		return -EINVAL;
+	}
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem) {
+		dev_err(&pdev->dev, "could not get mem\n");
+		return -ENODEV;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	if (rda_uart_ports[pdev->id]) {
+		dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
+		return -EBUSY;
+	}
+
+	rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
+	if (!rda_port)
+		return -ENOMEM;
+
+	rda_port->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(rda_port->clk)) {
+		dev_err(&pdev->dev, "could not get clk\n");
+		return PTR_ERR(rda_port->clk);
+	}
+
+	rda_port->port.dev = &pdev->dev;
+	rda_port->port.regshift = 0;
+	rda_port->port.line = pdev->id;
+	rda_port->port.type = PORT_RDA;
+	rda_port->port.iotype = UPIO_MEM;
+	rda_port->port.mapbase = res_mem->start;
+	rda_port->port.irq = irq;
+	rda_port->port.uartclk = clk_get_rate(rda_port->clk);
+	if (rda_port->port.uartclk == 0) {
+		dev_err(&pdev->dev, "clock rate is zero\n");
+		return -EINVAL;
+	}
+	rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
+			       UPF_LOW_LATENCY;
+	rda_port->port.x_char = 0;
+	rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
+	rda_port->port.ops = &rda_uart_ops;
+
+	rda_uart_ports[pdev->id] = rda_port;
+	platform_set_drvdata(pdev, rda_port);
+
+	ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
+	if (ret)
+		rda_uart_ports[pdev->id] = NULL;
+
+	return ret;
+}
+
+static int rda_uart_remove(struct platform_device *pdev)
+{
+	struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&rda_uart_driver, &rda_port->port);
+	rda_uart_ports[pdev->id] = NULL;
+
+	return 0;
+}
+
+static struct platform_driver rda_uart_platform_driver = {
+	.probe = rda_uart_probe,
+	.remove = rda_uart_remove,
+	.driver = {
+		.name = "rda-uart",
+		.of_match_table = rda_uart_dt_matches,
+	},
+};
+
+static int __init rda_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&rda_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&rda_uart_platform_driver);
+	if (ret)
+		uart_unregister_driver(&rda_uart_driver);
+
+	return ret;
+}
+
+static void __exit rda_uart_exit(void)
+{
+	platform_driver_unregister(&rda_uart_platform_driver);
+	uart_unregister_driver(&rda_uart_driver);
+}
+
+module_init(rda_uart_init);
+module_exit(rda_uart_exit);
+
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("RDA8810PL serial device driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/rp2.c b/drivers/tty/serial/rp2.c
new file mode 100644
index 000000000..de220ac8c
--- /dev/null
+++ b/drivers/tty/serial/rp2.c
@@ -0,0 +1,844 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Comtrol RocketPort EXPRESS/INFINITY cards
+ *
+ * Copyright (C) 2012 Kevin Cernekee <cernekee@gmail.com>
+ *
+ * Inspired by, and loosely based on:
+ *
+ *   ar933x_uart.c
+ *     Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *   rocketport_infinity_express-linux-1.20.tar.gz
+ *     Copyright (C) 2004-2011 Comtrol, Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/completion.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+
+#define DRV_NAME			"rp2"
+
+#define RP2_FW_NAME			"rp2.fw"
+#define RP2_UCODE_BYTES			0x3f
+
+#define PORTS_PER_ASIC			16
+#define ALL_PORTS_MASK			(BIT(PORTS_PER_ASIC) - 1)
+
+#define UART_CLOCK			44236800
+#define DEFAULT_BAUD_DIV		(UART_CLOCK / (9600 * 16))
+#define FIFO_SIZE			512
+
+/* BAR0 registers */
+#define RP2_FPGA_CTL0			0x110
+#define RP2_FPGA_CTL1			0x11c
+#define RP2_IRQ_MASK			0x1ec
+#define RP2_IRQ_MASK_EN_m		BIT(0)
+#define RP2_IRQ_STATUS			0x1f0
+
+/* BAR1 registers */
+#define RP2_ASIC_SPACING		0x1000
+#define RP2_ASIC_OFFSET(i)		((i) << ilog2(RP2_ASIC_SPACING))
+
+#define RP2_PORT_BASE			0x000
+#define RP2_PORT_SPACING		0x040
+
+#define RP2_UCODE_BASE			0x400
+#define RP2_UCODE_SPACING		0x80
+
+#define RP2_CLK_PRESCALER		0xc00
+#define RP2_CH_IRQ_STAT			0xc04
+#define RP2_CH_IRQ_MASK			0xc08
+#define RP2_ASIC_IRQ			0xd00
+#define RP2_ASIC_IRQ_EN_m		BIT(20)
+#define RP2_GLOBAL_CMD			0xd0c
+#define RP2_ASIC_CFG			0xd04
+
+/* port registers */
+#define RP2_DATA_DWORD			0x000
+
+#define RP2_DATA_BYTE			0x008
+#define RP2_DATA_BYTE_ERR_PARITY_m	BIT(8)
+#define RP2_DATA_BYTE_ERR_OVERRUN_m	BIT(9)
+#define RP2_DATA_BYTE_ERR_FRAMING_m	BIT(10)
+#define RP2_DATA_BYTE_BREAK_m		BIT(11)
+
+/* This lets uart_insert_char() drop bytes received on a !CREAD port */
+#define RP2_DUMMY_READ			BIT(16)
+
+#define RP2_DATA_BYTE_EXCEPTION_MASK	(RP2_DATA_BYTE_ERR_PARITY_m | \
+					 RP2_DATA_BYTE_ERR_OVERRUN_m | \
+					 RP2_DATA_BYTE_ERR_FRAMING_m | \
+					 RP2_DATA_BYTE_BREAK_m)
+
+#define RP2_RX_FIFO_COUNT		0x00c
+#define RP2_TX_FIFO_COUNT		0x00e
+
+#define RP2_CHAN_STAT			0x010
+#define RP2_CHAN_STAT_RXDATA_m		BIT(0)
+#define RP2_CHAN_STAT_DCD_m		BIT(3)
+#define RP2_CHAN_STAT_DSR_m		BIT(4)
+#define RP2_CHAN_STAT_CTS_m		BIT(5)
+#define RP2_CHAN_STAT_RI_m		BIT(6)
+#define RP2_CHAN_STAT_OVERRUN_m		BIT(13)
+#define RP2_CHAN_STAT_DSR_CHANGED_m	BIT(16)
+#define RP2_CHAN_STAT_CTS_CHANGED_m	BIT(17)
+#define RP2_CHAN_STAT_CD_CHANGED_m	BIT(18)
+#define RP2_CHAN_STAT_RI_CHANGED_m	BIT(22)
+#define RP2_CHAN_STAT_TXEMPTY_m		BIT(25)
+
+#define RP2_CHAN_STAT_MS_CHANGED_MASK	(RP2_CHAN_STAT_DSR_CHANGED_m | \
+					 RP2_CHAN_STAT_CTS_CHANGED_m | \
+					 RP2_CHAN_STAT_CD_CHANGED_m | \
+					 RP2_CHAN_STAT_RI_CHANGED_m)
+
+#define RP2_TXRX_CTL			0x014
+#define RP2_TXRX_CTL_MSRIRQ_m		BIT(0)
+#define RP2_TXRX_CTL_RXIRQ_m		BIT(2)
+#define RP2_TXRX_CTL_RX_TRIG_s		3
+#define RP2_TXRX_CTL_RX_TRIG_m		(0x3 << RP2_TXRX_CTL_RX_TRIG_s)
+#define RP2_TXRX_CTL_RX_TRIG_1		(0x1 << RP2_TXRX_CTL_RX_TRIG_s)
+#define RP2_TXRX_CTL_RX_TRIG_256	(0x2 << RP2_TXRX_CTL_RX_TRIG_s)
+#define RP2_TXRX_CTL_RX_TRIG_448	(0x3 << RP2_TXRX_CTL_RX_TRIG_s)
+#define RP2_TXRX_CTL_RX_EN_m		BIT(5)
+#define RP2_TXRX_CTL_RTSFLOW_m		BIT(6)
+#define RP2_TXRX_CTL_DTRFLOW_m		BIT(7)
+#define RP2_TXRX_CTL_TX_TRIG_s		16
+#define RP2_TXRX_CTL_TX_TRIG_m		(0x3 << RP2_TXRX_CTL_RX_TRIG_s)
+#define RP2_TXRX_CTL_DSRFLOW_m		BIT(18)
+#define RP2_TXRX_CTL_TXIRQ_m		BIT(19)
+#define RP2_TXRX_CTL_CTSFLOW_m		BIT(23)
+#define RP2_TXRX_CTL_TX_EN_m		BIT(24)
+#define RP2_TXRX_CTL_RTS_m		BIT(25)
+#define RP2_TXRX_CTL_DTR_m		BIT(26)
+#define RP2_TXRX_CTL_LOOP_m		BIT(27)
+#define RP2_TXRX_CTL_BREAK_m		BIT(28)
+#define RP2_TXRX_CTL_CMSPAR_m		BIT(29)
+#define RP2_TXRX_CTL_nPARODD_m		BIT(30)
+#define RP2_TXRX_CTL_PARENB_m		BIT(31)
+
+#define RP2_UART_CTL			0x018
+#define RP2_UART_CTL_MODE_s		0
+#define RP2_UART_CTL_MODE_m		(0x7 << RP2_UART_CTL_MODE_s)
+#define RP2_UART_CTL_MODE_rs232		(0x1 << RP2_UART_CTL_MODE_s)
+#define RP2_UART_CTL_FLUSH_RX_m		BIT(3)
+#define RP2_UART_CTL_FLUSH_TX_m		BIT(4)
+#define RP2_UART_CTL_RESET_CH_m		BIT(5)
+#define RP2_UART_CTL_XMIT_EN_m		BIT(6)
+#define RP2_UART_CTL_DATABITS_s		8
+#define RP2_UART_CTL_DATABITS_m		(0x3 << RP2_UART_CTL_DATABITS_s)
+#define RP2_UART_CTL_DATABITS_8		(0x3 << RP2_UART_CTL_DATABITS_s)
+#define RP2_UART_CTL_DATABITS_7		(0x2 << RP2_UART_CTL_DATABITS_s)
+#define RP2_UART_CTL_DATABITS_6		(0x1 << RP2_UART_CTL_DATABITS_s)
+#define RP2_UART_CTL_DATABITS_5		(0x0 << RP2_UART_CTL_DATABITS_s)
+#define RP2_UART_CTL_STOPBITS_m		BIT(10)
+
+#define RP2_BAUD			0x01c
+
+/* ucode registers */
+#define RP2_TX_SWFLOW			0x02
+#define RP2_TX_SWFLOW_ena		0x81
+#define RP2_TX_SWFLOW_dis		0x9d
+
+#define RP2_RX_SWFLOW			0x0c
+#define RP2_RX_SWFLOW_ena		0x81
+#define RP2_RX_SWFLOW_dis		0x8d
+
+#define RP2_RX_FIFO			0x37
+#define RP2_RX_FIFO_ena			0x08
+#define RP2_RX_FIFO_dis			0x81
+
+static struct uart_driver rp2_uart_driver = {
+	.owner				= THIS_MODULE,
+	.driver_name			= DRV_NAME,
+	.dev_name			= "ttyRP",
+	.nr				= CONFIG_SERIAL_RP2_NR_UARTS,
+};
+
+struct rp2_card;
+
+struct rp2_uart_port {
+	struct uart_port		port;
+	int				idx;
+	int				ignore_rx;
+	struct rp2_card			*card;
+	void __iomem			*asic_base;
+	void __iomem			*base;
+	void __iomem			*ucode;
+};
+
+struct rp2_card {
+	struct pci_dev			*pdev;
+	struct rp2_uart_port		*ports;
+	int				n_ports;
+	int				initialized_ports;
+	int				minor_start;
+	int				smpte;
+	void __iomem			*bar0;
+	void __iomem			*bar1;
+	spinlock_t			card_lock;
+};
+
+#define RP_ID(prod) PCI_VDEVICE(RP, (prod))
+#define RP_CAP(ports, smpte) (((ports) << 8) | ((smpte) << 0))
+
+static inline void rp2_decode_cap(const struct pci_device_id *id,
+				  int *ports, int *smpte)
+{
+	*ports = id->driver_data >> 8;
+	*smpte = id->driver_data & 0xff;
+}
+
+static DEFINE_SPINLOCK(rp2_minor_lock);
+static int rp2_minor_next;
+
+static int rp2_alloc_ports(int n_ports)
+{
+	int ret = -ENOSPC;
+
+	spin_lock(&rp2_minor_lock);
+	if (rp2_minor_next + n_ports <= CONFIG_SERIAL_RP2_NR_UARTS) {
+		/* sorry, no support for hot unplugging individual cards */
+		ret = rp2_minor_next;
+		rp2_minor_next += n_ports;
+	}
+	spin_unlock(&rp2_minor_lock);
+
+	return ret;
+}
+
+static inline struct rp2_uart_port *port_to_up(struct uart_port *port)
+{
+	return container_of(port, struct rp2_uart_port, port);
+}
+
+static void rp2_rmw(struct rp2_uart_port *up, int reg,
+		    u32 clr_bits, u32 set_bits)
+{
+	u32 tmp = readl(up->base + reg);
+	tmp &= ~clr_bits;
+	tmp |= set_bits;
+	writel(tmp, up->base + reg);
+}
+
+static void rp2_rmw_clr(struct rp2_uart_port *up, int reg, u32 val)
+{
+	rp2_rmw(up, reg, val, 0);
+}
+
+static void rp2_rmw_set(struct rp2_uart_port *up, int reg, u32 val)
+{
+	rp2_rmw(up, reg, 0, val);
+}
+
+static void rp2_mask_ch_irq(struct rp2_uart_port *up, int ch_num,
+			    int is_enabled)
+{
+	unsigned long flags, irq_mask;
+
+	spin_lock_irqsave(&up->card->card_lock, flags);
+
+	irq_mask = readl(up->asic_base + RP2_CH_IRQ_MASK);
+	if (is_enabled)
+		irq_mask &= ~BIT(ch_num);
+	else
+		irq_mask |= BIT(ch_num);
+	writel(irq_mask, up->asic_base + RP2_CH_IRQ_MASK);
+
+	spin_unlock_irqrestore(&up->card->card_lock, flags);
+}
+
+static unsigned int rp2_uart_tx_empty(struct uart_port *port)
+{
+	struct rp2_uart_port *up = port_to_up(port);
+	unsigned long tx_fifo_bytes, flags;
+
+	/*
+	 * This should probably check the transmitter, not the FIFO.
+	 * But the TXEMPTY bit doesn't seem to work unless the TX IRQ is
+	 * enabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+	tx_fifo_bytes = readw(up->base + RP2_TX_FIFO_COUNT);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return tx_fifo_bytes ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int rp2_uart_get_mctrl(struct uart_port *port)
+{
+	struct rp2_uart_port *up = port_to_up(port);
+	u32 status;
+
+	status = readl(up->base + RP2_CHAN_STAT);
+	return ((status & RP2_CHAN_STAT_DCD_m) ? TIOCM_CAR : 0) |
+	       ((status & RP2_CHAN_STAT_DSR_m) ? TIOCM_DSR : 0) |
+	       ((status & RP2_CHAN_STAT_CTS_m) ? TIOCM_CTS : 0) |
+	       ((status & RP2_CHAN_STAT_RI_m) ? TIOCM_RI : 0);
+}
+
+static void rp2_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	rp2_rmw(port_to_up(port), RP2_TXRX_CTL,
+		RP2_TXRX_CTL_DTR_m | RP2_TXRX_CTL_RTS_m | RP2_TXRX_CTL_LOOP_m,
+		((mctrl & TIOCM_DTR) ? RP2_TXRX_CTL_DTR_m : 0) |
+		((mctrl & TIOCM_RTS) ? RP2_TXRX_CTL_RTS_m : 0) |
+		((mctrl & TIOCM_LOOP) ? RP2_TXRX_CTL_LOOP_m : 0));
+}
+
+static void rp2_uart_start_tx(struct uart_port *port)
+{
+	rp2_rmw_set(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_TXIRQ_m);
+}
+
+static void rp2_uart_stop_tx(struct uart_port *port)
+{
+	rp2_rmw_clr(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_TXIRQ_m);
+}
+
+static void rp2_uart_stop_rx(struct uart_port *port)
+{
+	rp2_rmw_clr(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_RXIRQ_m);
+}
+
+static void rp2_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	rp2_rmw(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_BREAK_m,
+		break_state ? RP2_TXRX_CTL_BREAK_m : 0);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void rp2_uart_enable_ms(struct uart_port *port)
+{
+	rp2_rmw_set(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_MSRIRQ_m);
+}
+
+static void __rp2_uart_set_termios(struct rp2_uart_port *up,
+				   unsigned long cfl,
+				   unsigned long ifl,
+				   unsigned int baud_div)
+{
+	/* baud rate divisor (calculated elsewhere).  0 = divide-by-1 */
+	writew(baud_div - 1, up->base + RP2_BAUD);
+
+	/* data bits and stop bits */
+	rp2_rmw(up, RP2_UART_CTL,
+		RP2_UART_CTL_STOPBITS_m | RP2_UART_CTL_DATABITS_m,
+		((cfl & CSTOPB) ? RP2_UART_CTL_STOPBITS_m : 0) |
+		(((cfl & CSIZE) == CS8) ? RP2_UART_CTL_DATABITS_8 : 0) |
+		(((cfl & CSIZE) == CS7) ? RP2_UART_CTL_DATABITS_7 : 0) |
+		(((cfl & CSIZE) == CS6) ? RP2_UART_CTL_DATABITS_6 : 0) |
+		(((cfl & CSIZE) == CS5) ? RP2_UART_CTL_DATABITS_5 : 0));
+
+	/* parity and hardware flow control */
+	rp2_rmw(up, RP2_TXRX_CTL,
+		RP2_TXRX_CTL_PARENB_m | RP2_TXRX_CTL_nPARODD_m |
+		RP2_TXRX_CTL_CMSPAR_m | RP2_TXRX_CTL_DTRFLOW_m |
+		RP2_TXRX_CTL_DSRFLOW_m | RP2_TXRX_CTL_RTSFLOW_m |
+		RP2_TXRX_CTL_CTSFLOW_m,
+		((cfl & PARENB) ? RP2_TXRX_CTL_PARENB_m : 0) |
+		((cfl & PARODD) ? 0 : RP2_TXRX_CTL_nPARODD_m) |
+		((cfl & CMSPAR) ? RP2_TXRX_CTL_CMSPAR_m : 0) |
+		((cfl & CRTSCTS) ? (RP2_TXRX_CTL_RTSFLOW_m |
+				    RP2_TXRX_CTL_CTSFLOW_m) : 0));
+
+	/* XON/XOFF software flow control */
+	writeb((ifl & IXON) ? RP2_TX_SWFLOW_ena : RP2_TX_SWFLOW_dis,
+	       up->ucode + RP2_TX_SWFLOW);
+	writeb((ifl & IXOFF) ? RP2_RX_SWFLOW_ena : RP2_RX_SWFLOW_dis,
+	       up->ucode + RP2_RX_SWFLOW);
+}
+
+static void rp2_uart_set_termios(struct uart_port *port, struct ktermios *new,
+				 const struct ktermios *old)
+{
+	struct rp2_uart_port *up = port_to_up(port);
+	unsigned long flags;
+	unsigned int baud, baud_div;
+
+	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+	baud_div = uart_get_divisor(port, baud);
+
+	if (tty_termios_baud_rate(new))
+		tty_termios_encode_baud_rate(new, baud, baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* ignore all characters if CREAD is not set */
+	port->ignore_status_mask = (new->c_cflag & CREAD) ? 0 : RP2_DUMMY_READ;
+
+	__rp2_uart_set_termios(up, new->c_cflag, new->c_iflag, baud_div);
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void rp2_rx_chars(struct rp2_uart_port *up)
+{
+	u16 bytes = readw(up->base + RP2_RX_FIFO_COUNT);
+	struct tty_port *port = &up->port.state->port;
+
+	for (; bytes != 0; bytes--) {
+		u32 byte = readw(up->base + RP2_DATA_BYTE) | RP2_DUMMY_READ;
+		u8 ch = byte & 0xff;
+
+		if (likely(!(byte & RP2_DATA_BYTE_EXCEPTION_MASK))) {
+			if (!uart_handle_sysrq_char(&up->port, ch))
+				uart_insert_char(&up->port, byte, 0, ch,
+						 TTY_NORMAL);
+		} else {
+			u8 flag = TTY_NORMAL;
+
+			if (byte & RP2_DATA_BYTE_BREAK_m)
+				flag = TTY_BREAK;
+			else if (byte & RP2_DATA_BYTE_ERR_FRAMING_m)
+				flag = TTY_FRAME;
+			else if (byte & RP2_DATA_BYTE_ERR_PARITY_m)
+				flag = TTY_PARITY;
+			uart_insert_char(&up->port, byte,
+					 RP2_DATA_BYTE_ERR_OVERRUN_m, ch, flag);
+		}
+		up->port.icount.rx++;
+	}
+
+	tty_flip_buffer_push(port);
+}
+
+static void rp2_tx_chars(struct rp2_uart_port *up)
+{
+	u8 ch;
+
+	uart_port_tx_limited(&up->port, ch,
+		FIFO_SIZE - readw(up->base + RP2_TX_FIFO_COUNT),
+		true,
+		writeb(ch, up->base + RP2_DATA_BYTE),
+		({}));
+}
+
+static void rp2_ch_interrupt(struct rp2_uart_port *up)
+{
+	u32 status;
+
+	spin_lock(&up->port.lock);
+
+	/*
+	 * The IRQ status bits are clear-on-write.  Other status bits in
+	 * this register aren't, so it's harmless to write to them.
+	 */
+	status = readl(up->base + RP2_CHAN_STAT);
+	writel(status, up->base + RP2_CHAN_STAT);
+
+	if (status & RP2_CHAN_STAT_RXDATA_m)
+		rp2_rx_chars(up);
+	if (status & RP2_CHAN_STAT_TXEMPTY_m)
+		rp2_tx_chars(up);
+	if (status & RP2_CHAN_STAT_MS_CHANGED_MASK)
+		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+
+	spin_unlock(&up->port.lock);
+}
+
+static int rp2_asic_interrupt(struct rp2_card *card, unsigned int asic_id)
+{
+	void __iomem *base = card->bar1 + RP2_ASIC_OFFSET(asic_id);
+	int ch, handled = 0;
+	unsigned long status = readl(base + RP2_CH_IRQ_STAT) &
+			       ~readl(base + RP2_CH_IRQ_MASK);
+
+	for_each_set_bit(ch, &status, PORTS_PER_ASIC) {
+		rp2_ch_interrupt(&card->ports[ch]);
+		handled++;
+	}
+	return handled;
+}
+
+static irqreturn_t rp2_uart_interrupt(int irq, void *dev_id)
+{
+	struct rp2_card *card = dev_id;
+	int handled;
+
+	handled = rp2_asic_interrupt(card, 0);
+	if (card->n_ports >= PORTS_PER_ASIC)
+		handled += rp2_asic_interrupt(card, 1);
+
+	return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static inline void rp2_flush_fifos(struct rp2_uart_port *up)
+{
+	rp2_rmw_set(up, RP2_UART_CTL,
+		    RP2_UART_CTL_FLUSH_RX_m | RP2_UART_CTL_FLUSH_TX_m);
+	readl(up->base + RP2_UART_CTL);
+	udelay(10);
+	rp2_rmw_clr(up, RP2_UART_CTL,
+		    RP2_UART_CTL_FLUSH_RX_m | RP2_UART_CTL_FLUSH_TX_m);
+}
+
+static int rp2_uart_startup(struct uart_port *port)
+{
+	struct rp2_uart_port *up = port_to_up(port);
+
+	rp2_flush_fifos(up);
+	rp2_rmw(up, RP2_TXRX_CTL, RP2_TXRX_CTL_MSRIRQ_m, RP2_TXRX_CTL_RXIRQ_m);
+	rp2_rmw(up, RP2_TXRX_CTL, RP2_TXRX_CTL_RX_TRIG_m,
+		RP2_TXRX_CTL_RX_TRIG_1);
+	rp2_rmw(up, RP2_CHAN_STAT, 0, 0);
+	rp2_mask_ch_irq(up, up->idx, 1);
+
+	return 0;
+}
+
+static void rp2_uart_shutdown(struct uart_port *port)
+{
+	struct rp2_uart_port *up = port_to_up(port);
+	unsigned long flags;
+
+	rp2_uart_break_ctl(port, 0);
+
+	spin_lock_irqsave(&port->lock, flags);
+	rp2_mask_ch_irq(up, up->idx, 0);
+	rp2_rmw(up, RP2_CHAN_STAT, 0, 0);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *rp2_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_RP2) ? "RocketPort 2 UART" : NULL;
+}
+
+static void rp2_uart_release_port(struct uart_port *port)
+{
+	/* Nothing to release ... */
+}
+
+static int rp2_uart_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+static void rp2_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_RP2;
+}
+
+static int rp2_uart_verify_port(struct uart_port *port,
+				   struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_RP2)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops rp2_uart_ops = {
+	.tx_empty	= rp2_uart_tx_empty,
+	.set_mctrl	= rp2_uart_set_mctrl,
+	.get_mctrl	= rp2_uart_get_mctrl,
+	.stop_tx	= rp2_uart_stop_tx,
+	.start_tx	= rp2_uart_start_tx,
+	.stop_rx	= rp2_uart_stop_rx,
+	.enable_ms	= rp2_uart_enable_ms,
+	.break_ctl	= rp2_uart_break_ctl,
+	.startup	= rp2_uart_startup,
+	.shutdown	= rp2_uart_shutdown,
+	.set_termios	= rp2_uart_set_termios,
+	.type		= rp2_uart_type,
+	.release_port	= rp2_uart_release_port,
+	.request_port	= rp2_uart_request_port,
+	.config_port	= rp2_uart_config_port,
+	.verify_port	= rp2_uart_verify_port,
+};
+
+static void rp2_reset_asic(struct rp2_card *card, unsigned int asic_id)
+{
+	void __iomem *base = card->bar1 + RP2_ASIC_OFFSET(asic_id);
+	u32 clk_cfg;
+
+	writew(1, base + RP2_GLOBAL_CMD);
+	readw(base + RP2_GLOBAL_CMD);
+	msleep(100);
+	writel(0, base + RP2_CLK_PRESCALER);
+
+	/* TDM clock configuration */
+	clk_cfg = readw(base + RP2_ASIC_CFG);
+	clk_cfg = (clk_cfg & ~BIT(8)) | BIT(9);
+	writew(clk_cfg, base + RP2_ASIC_CFG);
+
+	/* IRQ routing */
+	writel(ALL_PORTS_MASK, base + RP2_CH_IRQ_MASK);
+	writel(RP2_ASIC_IRQ_EN_m, base + RP2_ASIC_IRQ);
+}
+
+static void rp2_init_card(struct rp2_card *card)
+{
+	writel(4, card->bar0 + RP2_FPGA_CTL0);
+	writel(0, card->bar0 + RP2_FPGA_CTL1);
+
+	rp2_reset_asic(card, 0);
+	if (card->n_ports >= PORTS_PER_ASIC)
+		rp2_reset_asic(card, 1);
+
+	writel(RP2_IRQ_MASK_EN_m, card->bar0 + RP2_IRQ_MASK);
+}
+
+static void rp2_init_port(struct rp2_uart_port *up, const struct firmware *fw)
+{
+	int i;
+
+	writel(RP2_UART_CTL_RESET_CH_m, up->base + RP2_UART_CTL);
+	readl(up->base + RP2_UART_CTL);
+	udelay(1);
+
+	writel(0, up->base + RP2_TXRX_CTL);
+	writel(0, up->base + RP2_UART_CTL);
+	readl(up->base + RP2_UART_CTL);
+	udelay(1);
+
+	rp2_flush_fifos(up);
+
+	for (i = 0; i < min_t(int, fw->size, RP2_UCODE_BYTES); i++)
+		writeb(fw->data[i], up->ucode + i);
+
+	__rp2_uart_set_termios(up, CS8 | CREAD | CLOCAL, 0, DEFAULT_BAUD_DIV);
+	rp2_uart_set_mctrl(&up->port, 0);
+
+	writeb(RP2_RX_FIFO_ena, up->ucode + RP2_RX_FIFO);
+	rp2_rmw(up, RP2_UART_CTL, RP2_UART_CTL_MODE_m,
+		RP2_UART_CTL_XMIT_EN_m | RP2_UART_CTL_MODE_rs232);
+	rp2_rmw_set(up, RP2_TXRX_CTL,
+		    RP2_TXRX_CTL_TX_EN_m | RP2_TXRX_CTL_RX_EN_m);
+}
+
+static void rp2_remove_ports(struct rp2_card *card)
+{
+	int i;
+
+	for (i = 0; i < card->initialized_ports; i++)
+		uart_remove_one_port(&rp2_uart_driver, &card->ports[i].port);
+	card->initialized_ports = 0;
+}
+
+static int rp2_load_firmware(struct rp2_card *card, const struct firmware *fw)
+{
+	resource_size_t phys_base;
+	int i, rc = 0;
+
+	phys_base = pci_resource_start(card->pdev, 1);
+
+	for (i = 0; i < card->n_ports; i++) {
+		struct rp2_uart_port *rp = &card->ports[i];
+		struct uart_port *p;
+		int j = (unsigned)i % PORTS_PER_ASIC;
+
+		rp->asic_base = card->bar1;
+		rp->base = card->bar1 + RP2_PORT_BASE + j*RP2_PORT_SPACING;
+		rp->ucode = card->bar1 + RP2_UCODE_BASE + j*RP2_UCODE_SPACING;
+		rp->card = card;
+		rp->idx = j;
+
+		p = &rp->port;
+		p->line = card->minor_start + i;
+		p->dev = &card->pdev->dev;
+		p->type = PORT_RP2;
+		p->iotype = UPIO_MEM32;
+		p->uartclk = UART_CLOCK;
+		p->regshift = 2;
+		p->fifosize = FIFO_SIZE;
+		p->ops = &rp2_uart_ops;
+		p->irq = card->pdev->irq;
+		p->membase = rp->base;
+		p->mapbase = phys_base + RP2_PORT_BASE + j*RP2_PORT_SPACING;
+
+		if (i >= PORTS_PER_ASIC) {
+			rp->asic_base += RP2_ASIC_SPACING;
+			rp->base += RP2_ASIC_SPACING;
+			rp->ucode += RP2_ASIC_SPACING;
+			p->mapbase += RP2_ASIC_SPACING;
+		}
+
+		rp2_init_port(rp, fw);
+		rc = uart_add_one_port(&rp2_uart_driver, p);
+		if (rc) {
+			dev_err(&card->pdev->dev,
+				"error registering port %d: %d\n", i, rc);
+			rp2_remove_ports(card);
+			break;
+		}
+		card->initialized_ports++;
+	}
+
+	return rc;
+}
+
+static int rp2_probe(struct pci_dev *pdev,
+				   const struct pci_device_id *id)
+{
+	const struct firmware *fw;
+	struct rp2_card *card;
+	struct rp2_uart_port *ports;
+	void __iomem * const *bars;
+	int rc;
+
+	card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL);
+	if (!card)
+		return -ENOMEM;
+	pci_set_drvdata(pdev, card);
+	spin_lock_init(&card->card_lock);
+
+	rc = pcim_enable_device(pdev);
+	if (rc)
+		return rc;
+
+	rc = pcim_iomap_regions_request_all(pdev, 0x03, DRV_NAME);
+	if (rc)
+		return rc;
+
+	bars = pcim_iomap_table(pdev);
+	card->bar0 = bars[0];
+	card->bar1 = bars[1];
+	card->pdev = pdev;
+
+	rp2_decode_cap(id, &card->n_ports, &card->smpte);
+	dev_info(&pdev->dev, "found new card with %d ports\n", card->n_ports);
+
+	card->minor_start = rp2_alloc_ports(card->n_ports);
+	if (card->minor_start < 0) {
+		dev_err(&pdev->dev,
+			"too many ports (try increasing CONFIG_SERIAL_RP2_NR_UARTS)\n");
+		return -EINVAL;
+	}
+
+	rp2_init_card(card);
+
+	ports = devm_kcalloc(&pdev->dev, card->n_ports, sizeof(*ports),
+			     GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+	card->ports = ports;
+
+	rc = request_firmware(&fw, RP2_FW_NAME, &pdev->dev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "cannot find '%s' firmware image\n",
+			RP2_FW_NAME);
+		return rc;
+	}
+
+	rc = rp2_load_firmware(card, fw);
+
+	release_firmware(fw);
+	if (rc < 0)
+		return rc;
+
+	rc = devm_request_irq(&pdev->dev, pdev->irq, rp2_uart_interrupt,
+			      IRQF_SHARED, DRV_NAME, card);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static void rp2_remove(struct pci_dev *pdev)
+{
+	struct rp2_card *card = pci_get_drvdata(pdev);
+
+	rp2_remove_ports(card);
+}
+
+static const struct pci_device_id rp2_pci_tbl[] = {
+
+	/* RocketPort INFINITY cards */
+
+	{ RP_ID(0x0040), RP_CAP(8,  0) }, /* INF Octa, RJ45, selectable */
+	{ RP_ID(0x0041), RP_CAP(32, 0) }, /* INF 32, ext interface */
+	{ RP_ID(0x0042), RP_CAP(8,  0) }, /* INF Octa, ext interface */
+	{ RP_ID(0x0043), RP_CAP(16, 0) }, /* INF 16, ext interface */
+	{ RP_ID(0x0044), RP_CAP(4,  0) }, /* INF Quad, DB, selectable */
+	{ RP_ID(0x0045), RP_CAP(8,  0) }, /* INF Octa, DB, selectable */
+	{ RP_ID(0x0046), RP_CAP(4,  0) }, /* INF Quad, ext interface */
+	{ RP_ID(0x0047), RP_CAP(4,  0) }, /* INF Quad, RJ45 */
+	{ RP_ID(0x004a), RP_CAP(4,  0) }, /* INF Plus, Quad */
+	{ RP_ID(0x004b), RP_CAP(8,  0) }, /* INF Plus, Octa */
+	{ RP_ID(0x004c), RP_CAP(8,  0) }, /* INF III, Octa */
+	{ RP_ID(0x004d), RP_CAP(4,  0) }, /* INF III, Quad */
+	{ RP_ID(0x004e), RP_CAP(2,  0) }, /* INF Plus, 2, RS232 */
+	{ RP_ID(0x004f), RP_CAP(2,  1) }, /* INF Plus, 2, SMPTE */
+	{ RP_ID(0x0050), RP_CAP(4,  0) }, /* INF Plus, Quad, RJ45 */
+	{ RP_ID(0x0051), RP_CAP(8,  0) }, /* INF Plus, Octa, RJ45 */
+	{ RP_ID(0x0052), RP_CAP(8,  1) }, /* INF Octa, SMPTE */
+
+	/* RocketPort EXPRESS cards */
+
+	{ RP_ID(0x0060), RP_CAP(8,  0) }, /* EXP Octa, RJ45, selectable */
+	{ RP_ID(0x0061), RP_CAP(32, 0) }, /* EXP 32, ext interface */
+	{ RP_ID(0x0062), RP_CAP(8,  0) }, /* EXP Octa, ext interface */
+	{ RP_ID(0x0063), RP_CAP(16, 0) }, /* EXP 16, ext interface */
+	{ RP_ID(0x0064), RP_CAP(4,  0) }, /* EXP Quad, DB, selectable */
+	{ RP_ID(0x0065), RP_CAP(8,  0) }, /* EXP Octa, DB, selectable */
+	{ RP_ID(0x0066), RP_CAP(4,  0) }, /* EXP Quad, ext interface */
+	{ RP_ID(0x0067), RP_CAP(4,  0) }, /* EXP Quad, RJ45 */
+	{ RP_ID(0x0068), RP_CAP(8,  0) }, /* EXP Octa, RJ11 */
+	{ RP_ID(0x0072), RP_CAP(8,  1) }, /* EXP Octa, SMPTE */
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, rp2_pci_tbl);
+
+static struct pci_driver rp2_pci_driver = {
+	.name		= DRV_NAME,
+	.id_table	= rp2_pci_tbl,
+	.probe		= rp2_probe,
+	.remove		= rp2_remove,
+};
+
+static int __init rp2_uart_init(void)
+{
+	int rc;
+
+	rc = uart_register_driver(&rp2_uart_driver);
+	if (rc)
+		return rc;
+
+	rc = pci_register_driver(&rp2_pci_driver);
+	if (rc) {
+		uart_unregister_driver(&rp2_uart_driver);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void __exit rp2_uart_exit(void)
+{
+	pci_unregister_driver(&rp2_pci_driver);
+	uart_unregister_driver(&rp2_uart_driver);
+}
+
+module_init(rp2_uart_init);
+module_exit(rp2_uart_exit);
+
+MODULE_DESCRIPTION("Comtrol RocketPort EXPRESS/INFINITY driver");
+MODULE_AUTHOR("Kevin Cernekee <cernekee@gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_FIRMWARE(RP2_FW_NAME);
diff --git a/drivers/tty/serial/sa1100.c b/drivers/tty/serial/sa1100.c
new file mode 100644
index 000000000..ad011f1e2
--- /dev/null
+++ b/drivers/tty/serial/sa1100.c
@@ -0,0 +1,923 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for SA11x0 serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_data/sa11x0-serial.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <mach/hardware.h>
+#include <mach/irqs.h>
+
+#include "serial_mctrl_gpio.h"
+
+/* We've been assigned a range on the "Low-density serial ports" major */
+#define SERIAL_SA1100_MAJOR	204
+#define MINOR_START		5
+
+#define NR_PORTS		3
+
+#define SA1100_ISR_PASS_LIMIT	256
+
+/*
+ * Convert from ignore_status_mask or read_status_mask to UTSR[01]
+ */
+#define SM_TO_UTSR0(x)	((x) & 0xff)
+#define SM_TO_UTSR1(x)	((x) >> 8)
+#define UTSR0_TO_SM(x)	((x))
+#define UTSR1_TO_SM(x)	((x) << 8)
+
+#define UART_GET_UTCR0(sport)	__raw_readl((sport)->port.membase + UTCR0)
+#define UART_GET_UTCR1(sport)	__raw_readl((sport)->port.membase + UTCR1)
+#define UART_GET_UTCR2(sport)	__raw_readl((sport)->port.membase + UTCR2)
+#define UART_GET_UTCR3(sport)	__raw_readl((sport)->port.membase + UTCR3)
+#define UART_GET_UTSR0(sport)	__raw_readl((sport)->port.membase + UTSR0)
+#define UART_GET_UTSR1(sport)	__raw_readl((sport)->port.membase + UTSR1)
+#define UART_GET_CHAR(sport)	__raw_readl((sport)->port.membase + UTDR)
+
+#define UART_PUT_UTCR0(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR0)
+#define UART_PUT_UTCR1(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR1)
+#define UART_PUT_UTCR2(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR2)
+#define UART_PUT_UTCR3(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR3)
+#define UART_PUT_UTSR0(sport,v)	__raw_writel((v),(sport)->port.membase + UTSR0)
+#define UART_PUT_UTSR1(sport,v)	__raw_writel((v),(sport)->port.membase + UTSR1)
+#define UART_PUT_CHAR(sport,v)	__raw_writel((v),(sport)->port.membase + UTDR)
+
+/*
+ * This is the size of our serial port register set.
+ */
+#define UART_PORT_SIZE	0x24
+
+/*
+ * This determines how often we check the modem status signals
+ * for any change.  They generally aren't connected to an IRQ
+ * so we have to poll them.  We also check immediately before
+ * filling the TX fifo incase CTS has been dropped.
+ */
+#define MCTRL_TIMEOUT	(250*HZ/1000)
+
+struct sa1100_port {
+	struct uart_port	port;
+	struct timer_list	timer;
+	unsigned int		old_status;
+	struct mctrl_gpios	*gpios;
+};
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void sa1100_mctrl_check(struct sa1100_port *sport)
+{
+	unsigned int status, changed;
+
+	status = sport->port.ops->get_mctrl(&sport->port);
+	changed = status ^ sport->old_status;
+
+	if (changed == 0)
+		return;
+
+	sport->old_status = status;
+
+	if (changed & TIOCM_RI)
+		sport->port.icount.rng++;
+	if (changed & TIOCM_DSR)
+		sport->port.icount.dsr++;
+	if (changed & TIOCM_CAR)
+		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
+	if (changed & TIOCM_CTS)
+		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
+
+	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
+}
+
+/*
+ * This is our per-port timeout handler, for checking the
+ * modem status signals.
+ */
+static void sa1100_timeout(struct timer_list *t)
+{
+	struct sa1100_port *sport = from_timer(sport, t, timer);
+	unsigned long flags;
+
+	if (sport->port.state) {
+		spin_lock_irqsave(&sport->port.lock, flags);
+		sa1100_mctrl_check(sport);
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+
+		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
+	}
+}
+
+/*
+ * interrupts disabled on entry
+ */
+static void sa1100_stop_tx(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	u32 utcr3;
+
+	utcr3 = UART_GET_UTCR3(sport);
+	UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_TIE);
+	sport->port.read_status_mask &= ~UTSR0_TO_SM(UTSR0_TFS);
+}
+
+/*
+ * port locked and interrupts disabled
+ */
+static void sa1100_start_tx(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	u32 utcr3;
+
+	utcr3 = UART_GET_UTCR3(sport);
+	sport->port.read_status_mask |= UTSR0_TO_SM(UTSR0_TFS);
+	UART_PUT_UTCR3(sport, utcr3 | UTCR3_TIE);
+}
+
+/*
+ * Interrupts enabled
+ */
+static void sa1100_stop_rx(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	u32 utcr3;
+
+	utcr3 = UART_GET_UTCR3(sport);
+	UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_RIE);
+}
+
+/*
+ * Set the modem control timer to fire immediately.
+ */
+static void sa1100_enable_ms(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	mod_timer(&sport->timer, jiffies);
+
+	mctrl_gpio_enable_ms(sport->gpios);
+}
+
+static void
+sa1100_rx_chars(struct sa1100_port *sport)
+{
+	unsigned int status;
+	u8 ch, flg;
+
+	status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
+		 UTSR0_TO_SM(UART_GET_UTSR0(sport));
+	while (status & UTSR1_TO_SM(UTSR1_RNE)) {
+		ch = UART_GET_CHAR(sport);
+
+		sport->port.icount.rx++;
+
+		flg = TTY_NORMAL;
+
+		/*
+		 * note that the error handling code is
+		 * out of the main execution path
+		 */
+		if (status & UTSR1_TO_SM(UTSR1_PRE | UTSR1_FRE | UTSR1_ROR)) {
+			if (status & UTSR1_TO_SM(UTSR1_PRE))
+				sport->port.icount.parity++;
+			else if (status & UTSR1_TO_SM(UTSR1_FRE))
+				sport->port.icount.frame++;
+			if (status & UTSR1_TO_SM(UTSR1_ROR))
+				sport->port.icount.overrun++;
+
+			status &= sport->port.read_status_mask;
+
+			if (status & UTSR1_TO_SM(UTSR1_PRE))
+				flg = TTY_PARITY;
+			else if (status & UTSR1_TO_SM(UTSR1_FRE))
+				flg = TTY_FRAME;
+
+			sport->port.sysrq = 0;
+		}
+
+		if (uart_handle_sysrq_char(&sport->port, ch))
+			goto ignore_char;
+
+		uart_insert_char(&sport->port, status, UTSR1_TO_SM(UTSR1_ROR), ch, flg);
+
+	ignore_char:
+		status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
+			 UTSR0_TO_SM(UART_GET_UTSR0(sport));
+	}
+
+	tty_flip_buffer_push(&sport->port.state->port);
+}
+
+static void sa1100_tx_chars(struct sa1100_port *sport)
+{
+	u8 ch;
+
+	/*
+	 * Check the modem control lines before
+	 * transmitting anything.
+	 */
+	sa1100_mctrl_check(sport);
+
+	uart_port_tx(&sport->port, ch,
+			UART_GET_UTSR1(sport) & UTSR1_TNF,
+			UART_PUT_CHAR(sport, ch));
+}
+
+static irqreturn_t sa1100_int(int irq, void *dev_id)
+{
+	struct sa1100_port *sport = dev_id;
+	unsigned int status, pass_counter = 0;
+
+	spin_lock(&sport->port.lock);
+	status = UART_GET_UTSR0(sport);
+	status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS;
+	do {
+		if (status & (UTSR0_RFS | UTSR0_RID)) {
+			/* Clear the receiver idle bit, if set */
+			if (status & UTSR0_RID)
+				UART_PUT_UTSR0(sport, UTSR0_RID);
+			sa1100_rx_chars(sport);
+		}
+
+		/* Clear the relevant break bits */
+		if (status & (UTSR0_RBB | UTSR0_REB))
+			UART_PUT_UTSR0(sport, status & (UTSR0_RBB | UTSR0_REB));
+
+		if (status & UTSR0_RBB)
+			sport->port.icount.brk++;
+
+		if (status & UTSR0_REB)
+			uart_handle_break(&sport->port);
+
+		if (status & UTSR0_TFS)
+			sa1100_tx_chars(sport);
+		if (pass_counter++ > SA1100_ISR_PASS_LIMIT)
+			break;
+		status = UART_GET_UTSR0(sport);
+		status &= SM_TO_UTSR0(sport->port.read_status_mask) |
+			  ~UTSR0_TFS;
+	} while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID));
+	spin_unlock(&sport->port.lock);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int sa1100_tx_empty(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	return UART_GET_UTSR1(sport) & UTSR1_TBY ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int sa1100_get_mctrl(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	int ret = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	mctrl_gpio_get(sport->gpios, &ret);
+
+	return ret;
+}
+
+static void sa1100_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	mctrl_gpio_set(sport->gpios, mctrl);
+}
+
+/*
+ * Interrupts always disabled.
+ */
+static void sa1100_break_ctl(struct uart_port *port, int break_state)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	unsigned long flags;
+	unsigned int utcr3;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	utcr3 = UART_GET_UTCR3(sport);
+	if (break_state == -1)
+		utcr3 |= UTCR3_BRK;
+	else
+		utcr3 &= ~UTCR3_BRK;
+	UART_PUT_UTCR3(sport, utcr3);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static int sa1100_startup(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	int retval;
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(sport->port.irq, sa1100_int, 0,
+			     "sa11x0-uart", sport);
+	if (retval)
+		return retval;
+
+	/*
+	 * Finally, clear and enable interrupts
+	 */
+	UART_PUT_UTSR0(sport, -1);
+	UART_PUT_UTCR3(sport, UTCR3_RXE | UTCR3_TXE | UTCR3_RIE);
+
+	/*
+	 * Enable modem status interrupts
+	 */
+	spin_lock_irq(&sport->port.lock);
+	sa1100_enable_ms(&sport->port);
+	spin_unlock_irq(&sport->port.lock);
+
+	return 0;
+}
+
+static void sa1100_shutdown(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	/*
+	 * Stop our timer.
+	 */
+	del_timer_sync(&sport->timer);
+
+	/*
+	 * Free the interrupt
+	 */
+	free_irq(sport->port.irq, sport);
+
+	/*
+	 * Disable all interrupts, port and break condition.
+	 */
+	UART_PUT_UTCR3(sport, 0);
+}
+
+static void
+sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
+		   const struct ktermios *old)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	unsigned long flags;
+	unsigned int utcr0, old_utcr3, baud, quot;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+
+	/*
+	 * We only support CS7 and CS8.
+	 */
+	while ((termios->c_cflag & CSIZE) != CS7 &&
+	       (termios->c_cflag & CSIZE) != CS8) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS8)
+		utcr0 = UTCR0_DSS;
+	else
+		utcr0 = 0;
+
+	if (termios->c_cflag & CSTOPB)
+		utcr0 |= UTCR0_SBS;
+	if (termios->c_cflag & PARENB) {
+		utcr0 |= UTCR0_PE;
+		if (!(termios->c_cflag & PARODD))
+			utcr0 |= UTCR0_OES;
+	}
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
+	quot = uart_get_divisor(port, baud);
+
+	del_timer_sync(&sport->timer);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	sport->port.read_status_mask &= UTSR0_TO_SM(UTSR0_TFS);
+	sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
+	if (termios->c_iflag & INPCK)
+		sport->port.read_status_mask |=
+				UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		sport->port.read_status_mask |=
+				UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
+
+	/*
+	 * Characters to ignore
+	 */
+	sport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		sport->port.ignore_status_mask |=
+				UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
+	if (termios->c_iflag & IGNBRK) {
+		sport->port.ignore_status_mask |=
+				UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			sport->port.ignore_status_mask |=
+				UTSR1_TO_SM(UTSR1_ROR);
+	}
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * disable interrupts and drain transmitter
+	 */
+	old_utcr3 = UART_GET_UTCR3(sport);
+	UART_PUT_UTCR3(sport, old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE));
+
+	while (UART_GET_UTSR1(sport) & UTSR1_TBY)
+		barrier();
+
+	/* then, disable everything */
+	UART_PUT_UTCR3(sport, 0);
+
+	/* set the parity, stop bits and data size */
+	UART_PUT_UTCR0(sport, utcr0);
+
+	/* set the baud rate */
+	quot -= 1;
+	UART_PUT_UTCR1(sport, ((quot & 0xf00) >> 8));
+	UART_PUT_UTCR2(sport, (quot & 0xff));
+
+	UART_PUT_UTSR0(sport, -1);
+
+	UART_PUT_UTCR3(sport, old_utcr3);
+
+	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
+		sa1100_enable_ms(&sport->port);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static const char *sa1100_type(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	return sport->port.type == PORT_SA1100 ? "SA1100" : NULL;
+}
+
+/*
+ * Release the memory region(s) being used by 'port'.
+ */
+static void sa1100_release_port(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
+}
+
+/*
+ * Request the memory region(s) being used by 'port'.
+ */
+static int sa1100_request_port(struct uart_port *port)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
+			"sa11x0-uart") != NULL ? 0 : -EBUSY;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void sa1100_config_port(struct uart_port *port, int flags)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	if (flags & UART_CONFIG_TYPE &&
+	    sa1100_request_port(&sport->port) == 0)
+		sport->port.type = PORT_SA1100;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ * The only change we allow are to the flags and type, and
+ * even then only between PORT_SA1100 and PORT_UNKNOWN
+ */
+static int
+sa1100_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SA1100)
+		ret = -EINVAL;
+	if (sport->port.irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->io_type != SERIAL_IO_MEM)
+		ret = -EINVAL;
+	if (sport->port.uartclk / 16 != ser->baud_base)
+		ret = -EINVAL;
+	if ((void *)sport->port.mapbase != ser->iomem_base)
+		ret = -EINVAL;
+	if (sport->port.iobase != ser->port)
+		ret = -EINVAL;
+	if (ser->hub6 != 0)
+		ret = -EINVAL;
+	return ret;
+}
+
+static struct uart_ops sa1100_pops = {
+	.tx_empty	= sa1100_tx_empty,
+	.set_mctrl	= sa1100_set_mctrl,
+	.get_mctrl	= sa1100_get_mctrl,
+	.stop_tx	= sa1100_stop_tx,
+	.start_tx	= sa1100_start_tx,
+	.stop_rx	= sa1100_stop_rx,
+	.enable_ms	= sa1100_enable_ms,
+	.break_ctl	= sa1100_break_ctl,
+	.startup	= sa1100_startup,
+	.shutdown	= sa1100_shutdown,
+	.set_termios	= sa1100_set_termios,
+	.type		= sa1100_type,
+	.release_port	= sa1100_release_port,
+	.request_port	= sa1100_request_port,
+	.config_port	= sa1100_config_port,
+	.verify_port	= sa1100_verify_port,
+};
+
+static struct sa1100_port sa1100_ports[NR_PORTS];
+
+/*
+ * Setup the SA1100 serial ports.  Note that we don't include the IrDA
+ * port here since we have our own SIR/FIR driver (see drivers/net/irda)
+ *
+ * Note also that we support "console=ttySAx" where "x" is either 0 or 1.
+ * Which serial port this ends up being depends on the machine you're
+ * running this kernel on.  I'm not convinced that this is a good idea,
+ * but that's the way it traditionally works.
+ *
+ * Note that NanoEngine UART3 becomes UART2, and UART2 is no longer
+ * used here.
+ */
+static void __init sa1100_init_ports(void)
+{
+	static int first = 1;
+	int i;
+
+	if (!first)
+		return;
+	first = 0;
+
+	for (i = 0; i < NR_PORTS; i++) {
+		sa1100_ports[i].port.uartclk   = 3686400;
+		sa1100_ports[i].port.ops       = &sa1100_pops;
+		sa1100_ports[i].port.fifosize  = 8;
+		sa1100_ports[i].port.line      = i;
+		sa1100_ports[i].port.iotype    = UPIO_MEM;
+		timer_setup(&sa1100_ports[i].timer, sa1100_timeout, 0);
+	}
+
+	/*
+	 * make transmit lines outputs, so that when the port
+	 * is closed, the output is in the MARK state.
+	 */
+	PPDR |= PPC_TXD1 | PPC_TXD3;
+	PPSR |= PPC_TXD1 | PPC_TXD3;
+}
+
+void sa1100_register_uart_fns(struct sa1100_port_fns *fns)
+{
+	if (fns->get_mctrl)
+		sa1100_pops.get_mctrl = fns->get_mctrl;
+	if (fns->set_mctrl)
+		sa1100_pops.set_mctrl = fns->set_mctrl;
+
+	sa1100_pops.pm       = fns->pm;
+	/*
+	 * FIXME: fns->set_wake is unused - this should be called from
+	 * the suspend() callback if device_may_wakeup(dev)) is set.
+	 */
+}
+
+void __init sa1100_register_uart(int idx, int port)
+{
+	if (idx >= NR_PORTS) {
+		printk(KERN_ERR "%s: bad index number %d\n", __func__, idx);
+		return;
+	}
+
+	switch (port) {
+	case 1:
+		sa1100_ports[idx].port.membase = (void __iomem *)&Ser1UTCR0;
+		sa1100_ports[idx].port.mapbase = _Ser1UTCR0;
+		sa1100_ports[idx].port.irq     = IRQ_Ser1UART;
+		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
+		break;
+
+	case 2:
+		sa1100_ports[idx].port.membase = (void __iomem *)&Ser2UTCR0;
+		sa1100_ports[idx].port.mapbase = _Ser2UTCR0;
+		sa1100_ports[idx].port.irq     = IRQ_Ser2ICP;
+		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
+		break;
+
+	case 3:
+		sa1100_ports[idx].port.membase = (void __iomem *)&Ser3UTCR0;
+		sa1100_ports[idx].port.mapbase = _Ser3UTCR0;
+		sa1100_ports[idx].port.irq     = IRQ_Ser3UART;
+		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
+		break;
+
+	default:
+		printk(KERN_ERR "%s: bad port number %d\n", __func__, port);
+	}
+}
+
+
+#ifdef CONFIG_SERIAL_SA1100_CONSOLE
+static void sa1100_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct sa1100_port *sport =
+		container_of(port, struct sa1100_port, port);
+
+	while (!(UART_GET_UTSR1(sport) & UTSR1_TNF))
+		barrier();
+	UART_PUT_CHAR(sport, ch);
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+sa1100_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct sa1100_port *sport = &sa1100_ports[co->index];
+	unsigned int old_utcr3, status;
+
+	/*
+	 *	First, save UTCR3 and then disable interrupts
+	 */
+	old_utcr3 = UART_GET_UTCR3(sport);
+	UART_PUT_UTCR3(sport, (old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE)) |
+				UTCR3_TXE);
+
+	uart_console_write(&sport->port, s, count, sa1100_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore UTCR3
+	 */
+	do {
+		status = UART_GET_UTSR1(sport);
+	} while (status & UTSR1_TBY);
+	UART_PUT_UTCR3(sport, old_utcr3);
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+sa1100_console_get_options(struct sa1100_port *sport, int *baud,
+			   int *parity, int *bits)
+{
+	unsigned int utcr3;
+
+	utcr3 = UART_GET_UTCR3(sport) & (UTCR3_RXE | UTCR3_TXE);
+	if (utcr3 == (UTCR3_RXE | UTCR3_TXE)) {
+		/* ok, the port was enabled */
+		unsigned int utcr0, quot;
+
+		utcr0 = UART_GET_UTCR0(sport);
+
+		*parity = 'n';
+		if (utcr0 & UTCR0_PE) {
+			if (utcr0 & UTCR0_OES)
+				*parity = 'e';
+			else
+				*parity = 'o';
+		}
+
+		if (utcr0 & UTCR0_DSS)
+			*bits = 8;
+		else
+			*bits = 7;
+
+		quot = UART_GET_UTCR2(sport) | UART_GET_UTCR1(sport) << 8;
+		quot &= 0xfff;
+		*baud = sport->port.uartclk / (16 * (quot + 1));
+	}
+}
+
+static int __init
+sa1100_console_setup(struct console *co, char *options)
+{
+	struct sa1100_port *sport;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= NR_PORTS)
+		co->index = 0;
+	sport = &sa1100_ports[co->index];
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		sa1100_console_get_options(sport, &baud, &parity, &bits);
+
+	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sa1100_reg;
+static struct console sa1100_console = {
+	.name		= "ttySA",
+	.write		= sa1100_console_write,
+	.device		= uart_console_device,
+	.setup		= sa1100_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &sa1100_reg,
+};
+
+static int __init sa1100_rs_console_init(void)
+{
+	sa1100_init_ports();
+	register_console(&sa1100_console);
+	return 0;
+}
+console_initcall(sa1100_rs_console_init);
+
+#define SA1100_CONSOLE	&sa1100_console
+#else
+#define SA1100_CONSOLE	NULL
+#endif
+
+static struct uart_driver sa1100_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "ttySA",
+	.dev_name		= "ttySA",
+	.major			= SERIAL_SA1100_MAJOR,
+	.minor			= MINOR_START,
+	.nr			= NR_PORTS,
+	.cons			= SA1100_CONSOLE,
+};
+
+static int sa1100_serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct sa1100_port *sport = platform_get_drvdata(dev);
+
+	if (sport)
+		uart_suspend_port(&sa1100_reg, &sport->port);
+
+	return 0;
+}
+
+static int sa1100_serial_resume(struct platform_device *dev)
+{
+	struct sa1100_port *sport = platform_get_drvdata(dev);
+
+	if (sport)
+		uart_resume_port(&sa1100_reg, &sport->port);
+
+	return 0;
+}
+
+static int sa1100_serial_add_one_port(struct sa1100_port *sport, struct platform_device *dev)
+{
+	sport->port.dev = &dev->dev;
+	sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SA1100_CONSOLE);
+
+	// mctrl_gpio_init() requires that the GPIO driver supports interrupts,
+	// but we need to support GPIO drivers for hardware that has no such
+	// interrupts.  Use mctrl_gpio_init_noauto() instead.
+	sport->gpios = mctrl_gpio_init_noauto(sport->port.dev, 0);
+	if (IS_ERR(sport->gpios)) {
+		int err = PTR_ERR(sport->gpios);
+
+		dev_err(sport->port.dev, "failed to get mctrl gpios: %d\n",
+			err);
+
+		if (err == -EPROBE_DEFER)
+			return err;
+
+		sport->gpios = NULL;
+	}
+
+	platform_set_drvdata(dev, sport);
+
+	return uart_add_one_port(&sa1100_reg, &sport->port);
+}
+
+static int sa1100_serial_probe(struct platform_device *dev)
+{
+	struct resource *res;
+	int i;
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	for (i = 0; i < NR_PORTS; i++)
+		if (sa1100_ports[i].port.mapbase == res->start)
+			break;
+	if (i == NR_PORTS)
+		return -ENODEV;
+
+	sa1100_serial_add_one_port(&sa1100_ports[i], dev);
+
+	return 0;
+}
+
+static int sa1100_serial_remove(struct platform_device *pdev)
+{
+	struct sa1100_port *sport = platform_get_drvdata(pdev);
+
+	if (sport)
+		uart_remove_one_port(&sa1100_reg, &sport->port);
+
+	return 0;
+}
+
+static struct platform_driver sa11x0_serial_driver = {
+	.probe		= sa1100_serial_probe,
+	.remove		= sa1100_serial_remove,
+	.suspend	= sa1100_serial_suspend,
+	.resume		= sa1100_serial_resume,
+	.driver		= {
+		.name	= "sa11x0-uart",
+	},
+};
+
+static int __init sa1100_serial_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Serial: SA11x0 driver\n");
+
+	sa1100_init_ports();
+
+	ret = uart_register_driver(&sa1100_reg);
+	if (ret == 0) {
+		ret = platform_driver_register(&sa11x0_serial_driver);
+		if (ret)
+			uart_unregister_driver(&sa1100_reg);
+	}
+	return ret;
+}
+
+static void __exit sa1100_serial_exit(void)
+{
+	platform_driver_unregister(&sa11x0_serial_driver);
+	uart_unregister_driver(&sa1100_reg);
+}
+
+module_init(sa1100_serial_init);
+module_exit(sa1100_serial_exit);
+
+MODULE_AUTHOR("Deep Blue Solutions Ltd");
+MODULE_DESCRIPTION("SA1100 generic serial port driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_SA1100_MAJOR);
+MODULE_ALIAS("platform:sa11x0-uart");
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
new file mode 100644
index 000000000..07fb8a9da
--- /dev/null
+++ b/drivers/tty/serial/samsung_tty.c
@@ -0,0 +1,2914 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver core for Samsung SoC onboard UARTs.
+ *
+ * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
+ *	http://armlinux.simtec.co.uk/
+ */
+
+/* Note on 2410 error handling
+ *
+ * The s3c2410 manual has a love/hate affair with the contents of the
+ * UERSTAT register in the UART blocks, and keeps marking some of the
+ * error bits as reserved. Having checked with the s3c2410x01,
+ * it copes with BREAKs properly, so I am happy to ignore the RESERVED
+ * feature from the latter versions of the manual.
+ *
+ * If it becomes aparrent that latter versions of the 2410 remove these
+ * bits, then action will have to be taken to differentiate the versions
+ * and change the policy on BREAK
+ *
+ * BJD, 04-Nov-2004
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/serial_s3c.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/of.h>
+#include <asm/irq.h>
+
+/* UART name and device definitions */
+
+#define S3C24XX_SERIAL_NAME	"ttySAC"
+#define S3C24XX_SERIAL_MAJOR	204
+#define S3C24XX_SERIAL_MINOR	64
+
+#ifdef CONFIG_ARM64
+#define UART_NR			12
+#else
+#define UART_NR			CONFIG_SERIAL_SAMSUNG_UARTS
+#endif
+
+#define S3C24XX_TX_PIO			1
+#define S3C24XX_TX_DMA			2
+#define S3C24XX_RX_PIO			1
+#define S3C24XX_RX_DMA			2
+
+/* flag to ignore all characters coming in */
+#define RXSTAT_DUMMY_READ (0x10000000)
+
+enum s3c24xx_port_type {
+	TYPE_S3C24XX,
+	TYPE_S3C6400,
+	TYPE_APPLE_S5L,
+};
+
+struct s3c24xx_uart_info {
+	const char		*name;
+	enum s3c24xx_port_type	type;
+	unsigned int		port_type;
+	unsigned int		fifosize;
+	unsigned long		rx_fifomask;
+	unsigned long		rx_fifoshift;
+	unsigned long		rx_fifofull;
+	unsigned long		tx_fifomask;
+	unsigned long		tx_fifoshift;
+	unsigned long		tx_fifofull;
+	unsigned int		def_clk_sel;
+	unsigned long		num_clks;
+	unsigned long		clksel_mask;
+	unsigned long		clksel_shift;
+	unsigned long		ucon_mask;
+
+	/* uart port features */
+
+	unsigned int		has_divslot:1;
+};
+
+struct s3c24xx_serial_drv_data {
+	const struct s3c24xx_uart_info	info;
+	const struct s3c2410_uartcfg	def_cfg;
+	const unsigned int		fifosize[UART_NR];
+};
+
+struct s3c24xx_uart_dma {
+	unsigned int			rx_chan_id;
+	unsigned int			tx_chan_id;
+
+	struct dma_slave_config		rx_conf;
+	struct dma_slave_config		tx_conf;
+
+	struct dma_chan			*rx_chan;
+	struct dma_chan			*tx_chan;
+
+	dma_addr_t			rx_addr;
+	dma_addr_t			tx_addr;
+
+	dma_cookie_t			rx_cookie;
+	dma_cookie_t			tx_cookie;
+
+	char				*rx_buf;
+
+	dma_addr_t			tx_transfer_addr;
+
+	size_t				rx_size;
+	size_t				tx_size;
+
+	struct dma_async_tx_descriptor	*tx_desc;
+	struct dma_async_tx_descriptor	*rx_desc;
+
+	int				tx_bytes_requested;
+	int				rx_bytes_requested;
+};
+
+struct s3c24xx_uart_port {
+	unsigned char			rx_claimed;
+	unsigned char			tx_claimed;
+	unsigned char			rx_enabled;
+	unsigned char			tx_enabled;
+	unsigned int			pm_level;
+	unsigned long			baudclk_rate;
+	unsigned int			min_dma_size;
+
+	unsigned int			rx_irq;
+	unsigned int			tx_irq;
+
+	unsigned int			tx_in_progress;
+	unsigned int			tx_mode;
+	unsigned int			rx_mode;
+
+	const struct s3c24xx_uart_info	*info;
+	struct clk			*clk;
+	struct clk			*baudclk;
+	struct uart_port		port;
+	const struct s3c24xx_serial_drv_data	*drv_data;
+
+	/* reference to platform data */
+	const struct s3c2410_uartcfg	*cfg;
+
+	struct s3c24xx_uart_dma		*dma;
+};
+
+static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
+
+/* conversion functions */
+
+#define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
+
+/* register access controls */
+
+#define portaddr(port, reg) ((port)->membase + (reg))
+#define portaddrl(port, reg) \
+	((unsigned long *)(unsigned long)((port)->membase + (reg)))
+
+static u32 rd_reg(const struct uart_port *port, u32 reg)
+{
+	switch (port->iotype) {
+	case UPIO_MEM:
+		return readb_relaxed(portaddr(port, reg));
+	case UPIO_MEM32:
+		return readl_relaxed(portaddr(port, reg));
+	default:
+		return 0;
+	}
+	return 0;
+}
+
+#define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
+
+static void wr_reg(const struct uart_port *port, u32 reg, u32 val)
+{
+	switch (port->iotype) {
+	case UPIO_MEM:
+		writeb_relaxed(val, portaddr(port, reg));
+		break;
+	case UPIO_MEM32:
+		writel_relaxed(val, portaddr(port, reg));
+		break;
+	}
+}
+
+#define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
+
+/* Byte-order aware bit setting/clearing functions. */
+
+static inline void s3c24xx_set_bit(const struct uart_port *port, int idx,
+				   unsigned int reg)
+{
+	unsigned long flags;
+	u32 val;
+
+	local_irq_save(flags);
+	val = rd_regl(port, reg);
+	val |= (1 << idx);
+	wr_regl(port, reg, val);
+	local_irq_restore(flags);
+}
+
+static inline void s3c24xx_clear_bit(const struct uart_port *port, int idx,
+				     unsigned int reg)
+{
+	unsigned long flags;
+	u32 val;
+
+	local_irq_save(flags);
+	val = rd_regl(port, reg);
+	val &= ~(1 << idx);
+	wr_regl(port, reg, val);
+	local_irq_restore(flags);
+}
+
+static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
+{
+	return container_of(port, struct s3c24xx_uart_port, port);
+}
+
+/* translate a port to the device name */
+
+static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
+{
+	return to_platform_device(port->dev)->name;
+}
+
+static int s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
+{
+	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
+}
+
+static void s3c24xx_serial_rx_enable(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	unsigned long flags;
+	unsigned int ucon, ufcon;
+	int count = 10000;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (--count && !s3c24xx_serial_txempty_nofifo(port))
+		udelay(100);
+
+	ufcon = rd_regl(port, S3C2410_UFCON);
+	ufcon |= S3C2410_UFCON_RESETRX;
+	wr_regl(port, S3C2410_UFCON, ufcon);
+
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon |= S3C2410_UCON_RXIRQMODE;
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	ourport->rx_enabled = 1;
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void s3c24xx_serial_rx_disable(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	unsigned long flags;
+	unsigned int ucon;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~S3C2410_UCON_RXIRQMODE;
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	ourport->rx_enabled = 0;
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void s3c24xx_serial_stop_tx(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct dma_tx_state state;
+	int count;
+
+	if (!ourport->tx_enabled)
+		return;
+
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
+		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
+		break;
+	case TYPE_APPLE_S5L:
+		s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON);
+		break;
+	default:
+		disable_irq_nosync(ourport->tx_irq);
+		break;
+	}
+
+	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
+		dmaengine_pause(dma->tx_chan);
+		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
+		dmaengine_terminate_all(dma->tx_chan);
+		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
+					dma->tx_transfer_addr, dma->tx_size,
+					DMA_TO_DEVICE);
+		async_tx_ack(dma->tx_desc);
+		count = dma->tx_bytes_requested - state.residue;
+		uart_xmit_advance(port, count);
+	}
+
+	ourport->tx_enabled = 0;
+	ourport->tx_in_progress = 0;
+
+	if (port->flags & UPF_CONS_FLOW)
+		s3c24xx_serial_rx_enable(port);
+
+	ourport->tx_mode = 0;
+}
+
+static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
+
+static void s3c24xx_serial_tx_dma_complete(void *args)
+{
+	struct s3c24xx_uart_port *ourport = args;
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct dma_tx_state state;
+	unsigned long flags;
+	int count;
+
+	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
+	count = dma->tx_bytes_requested - state.residue;
+	async_tx_ack(dma->tx_desc);
+
+	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
+				dma->tx_transfer_addr, dma->tx_size,
+				DMA_TO_DEVICE);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_xmit_advance(port, count);
+	ourport->tx_in_progress = 0;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	s3c24xx_serial_start_next_tx(ourport);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
+{
+	const struct uart_port *port = &ourport->port;
+	u32 ucon;
+
+	/* Mask Tx interrupt */
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
+		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
+		break;
+	case TYPE_APPLE_S5L:
+		WARN_ON(1); // No DMA
+		break;
+	default:
+		disable_irq_nosync(ourport->tx_irq);
+		break;
+	}
+
+	/* Enable tx dma mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
+	ucon |= S3C64XX_UCON_TXBURST_1;
+	ucon |= S3C64XX_UCON_TXMODE_DMA;
+	wr_regl(port,  S3C2410_UCON, ucon);
+
+	ourport->tx_mode = S3C24XX_TX_DMA;
+}
+
+static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
+{
+	const struct uart_port *port = &ourport->port;
+	u32 ucon, ufcon;
+
+	/* Set ufcon txtrig */
+	ourport->tx_in_progress = S3C24XX_TX_PIO;
+	ufcon = rd_regl(port, S3C2410_UFCON);
+	wr_regl(port,  S3C2410_UFCON, ufcon);
+
+	/* Enable tx pio mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
+	ucon |= S3C64XX_UCON_TXMODE_CPU;
+	wr_regl(port,  S3C2410_UCON, ucon);
+
+	/* Unmask Tx interrupt */
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
+		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
+				  S3C64XX_UINTM);
+		break;
+	case TYPE_APPLE_S5L:
+		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
+		wr_regl(port, S3C2410_UCON, ucon);
+		break;
+	default:
+		enable_irq(ourport->tx_irq);
+		break;
+	}
+
+	ourport->tx_mode = S3C24XX_TX_PIO;
+
+	/*
+	 * The Apple version only has edge triggered TX IRQs, so we need
+	 * to kick off the process by sending some characters here.
+	 */
+	if (ourport->info->type == TYPE_APPLE_S5L)
+		s3c24xx_serial_tx_chars(ourport);
+}
+
+static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
+{
+	if (ourport->tx_mode != S3C24XX_TX_PIO)
+		enable_tx_pio(ourport);
+}
+
+static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
+				      unsigned int count)
+{
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+
+	if (ourport->tx_mode != S3C24XX_TX_DMA)
+		enable_tx_dma(ourport);
+
+	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
+	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
+
+	dma_sync_single_for_device(dma->tx_chan->device->dev,
+				   dma->tx_transfer_addr, dma->tx_size,
+				   DMA_TO_DEVICE);
+
+	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
+				dma->tx_transfer_addr, dma->tx_size,
+				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
+	if (!dma->tx_desc) {
+		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
+		return -EIO;
+	}
+
+	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
+	dma->tx_desc->callback_param = ourport;
+	dma->tx_bytes_requested = dma->tx_size;
+
+	ourport->tx_in_progress = S3C24XX_TX_DMA;
+	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
+	dma_async_issue_pending(dma->tx_chan);
+	return 0;
+}
+
+static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long count;
+
+	/* Get data size up to the end of buffer */
+	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	if (!count) {
+		s3c24xx_serial_stop_tx(port);
+		return;
+	}
+
+	if (!ourport->dma || !ourport->dma->tx_chan ||
+	    count < ourport->min_dma_size ||
+	    xmit->tail & (dma_get_cache_alignment() - 1))
+		s3c24xx_serial_start_tx_pio(ourport);
+	else
+		s3c24xx_serial_start_tx_dma(ourport, count);
+}
+
+static void s3c24xx_serial_start_tx(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (!ourport->tx_enabled) {
+		if (port->flags & UPF_CONS_FLOW)
+			s3c24xx_serial_rx_disable(port);
+
+		ourport->tx_enabled = 1;
+		if (!ourport->dma || !ourport->dma->tx_chan)
+			s3c24xx_serial_start_tx_pio(ourport);
+	}
+
+	if (ourport->dma && ourport->dma->tx_chan) {
+		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
+			s3c24xx_serial_start_next_tx(ourport);
+	}
+}
+
+static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
+		struct tty_port *tty, int count)
+{
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	int copied;
+
+	if (!count)
+		return;
+
+	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
+				dma->rx_size, DMA_FROM_DEVICE);
+
+	ourport->port.icount.rx += count;
+	if (!tty) {
+		dev_err(ourport->port.dev, "No tty port\n");
+		return;
+	}
+	copied = tty_insert_flip_string(tty,
+			((unsigned char *)(ourport->dma->rx_buf)), count);
+	if (copied != count) {
+		WARN_ON(1);
+		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
+	}
+}
+
+static void s3c24xx_serial_stop_rx(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct tty_port *t = &port->state->port;
+	struct dma_tx_state state;
+	enum dma_status dma_status;
+	unsigned int received;
+
+	if (ourport->rx_enabled) {
+		dev_dbg(port->dev, "stopping rx\n");
+		switch (ourport->info->type) {
+		case TYPE_S3C6400:
+			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
+					S3C64XX_UINTM);
+			break;
+		case TYPE_APPLE_S5L:
+			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
+			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
+			break;
+		default:
+			disable_irq_nosync(ourport->rx_irq);
+			break;
+		}
+		ourport->rx_enabled = 0;
+	}
+	if (dma && dma->rx_chan) {
+		dmaengine_pause(dma->tx_chan);
+		dma_status = dmaengine_tx_status(dma->rx_chan,
+				dma->rx_cookie, &state);
+		if (dma_status == DMA_IN_PROGRESS ||
+			dma_status == DMA_PAUSED) {
+			received = dma->rx_bytes_requested - state.residue;
+			dmaengine_terminate_all(dma->rx_chan);
+			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
+		}
+	}
+}
+
+static inline const struct s3c24xx_uart_info
+	*s3c24xx_port_to_info(struct uart_port *port)
+{
+	return to_ourport(port)->info;
+}
+
+static inline const struct s3c2410_uartcfg
+	*s3c24xx_port_to_cfg(const struct uart_port *port)
+{
+	const struct s3c24xx_uart_port *ourport;
+
+	if (port->dev == NULL)
+		return NULL;
+
+	ourport = container_of(port, struct s3c24xx_uart_port, port);
+	return ourport->cfg;
+}
+
+static int s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport,
+				     unsigned long ufstat)
+{
+	const struct s3c24xx_uart_info *info = ourport->info;
+
+	if (ufstat & info->rx_fifofull)
+		return ourport->port.fifosize;
+
+	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
+}
+
+static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
+static void s3c24xx_serial_rx_dma_complete(void *args)
+{
+	struct s3c24xx_uart_port *ourport = args;
+	struct uart_port *port = &ourport->port;
+
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct tty_port *t = &port->state->port;
+	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
+
+	struct dma_tx_state state;
+	unsigned long flags;
+	int received;
+
+	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
+	received  = dma->rx_bytes_requested - state.residue;
+	async_tx_ack(dma->rx_desc);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (received)
+		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
+
+	if (tty) {
+		tty_flip_buffer_push(t);
+		tty_kref_put(tty);
+	}
+
+	s3c64xx_start_rx_dma(ourport);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
+{
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+
+	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
+				   dma->rx_size, DMA_FROM_DEVICE);
+
+	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
+				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
+				DMA_PREP_INTERRUPT);
+	if (!dma->rx_desc) {
+		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
+		return;
+	}
+
+	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
+	dma->rx_desc->callback_param = ourport;
+	dma->rx_bytes_requested = dma->rx_size;
+
+	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
+	dma_async_issue_pending(dma->rx_chan);
+}
+
+/* ? - where has parity gone?? */
+#define S3C2410_UERSTAT_PARITY (0x1000)
+
+static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	unsigned int ucon;
+
+	/* set Rx mode to DMA mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
+			S3C64XX_UCON_TIMEOUT_MASK |
+			S3C64XX_UCON_EMPTYINT_EN |
+			S3C64XX_UCON_DMASUS_EN |
+			S3C64XX_UCON_TIMEOUT_EN |
+			S3C64XX_UCON_RXMODE_MASK);
+	ucon |= S3C64XX_UCON_RXBURST_1 |
+			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
+			S3C64XX_UCON_EMPTYINT_EN |
+			S3C64XX_UCON_TIMEOUT_EN |
+			S3C64XX_UCON_RXMODE_DMA;
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	ourport->rx_mode = S3C24XX_RX_DMA;
+}
+
+static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	unsigned int ucon;
+
+	/* set Rx mode to DMA mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
+	ucon |= S3C64XX_UCON_RXMODE_CPU;
+
+	/* Apple types use these bits for IRQ masks */
+	if (ourport->info->type != TYPE_APPLE_S5L) {
+		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
+				S3C64XX_UCON_EMPTYINT_EN |
+				S3C64XX_UCON_DMASUS_EN |
+				S3C64XX_UCON_TIMEOUT_EN);
+		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
+				S3C64XX_UCON_TIMEOUT_EN;
+	}
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	ourport->rx_mode = S3C24XX_RX_PIO;
+}
+
+static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
+
+static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
+{
+	unsigned int utrstat, received;
+	struct s3c24xx_uart_port *ourport = dev_id;
+	struct uart_port *port = &ourport->port;
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
+	struct tty_port *t = &port->state->port;
+	struct dma_tx_state state;
+
+	utrstat = rd_regl(port, S3C2410_UTRSTAT);
+	rd_regl(port, S3C2410_UFSTAT);
+
+	spin_lock(&port->lock);
+
+	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
+		s3c64xx_start_rx_dma(ourport);
+		if (ourport->rx_mode == S3C24XX_RX_PIO)
+			enable_rx_dma(ourport);
+		goto finish;
+	}
+
+	if (ourport->rx_mode == S3C24XX_RX_DMA) {
+		dmaengine_pause(dma->rx_chan);
+		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
+		dmaengine_terminate_all(dma->rx_chan);
+		received = dma->rx_bytes_requested - state.residue;
+		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
+
+		enable_rx_pio(ourport);
+	}
+
+	s3c24xx_serial_rx_drain_fifo(ourport);
+
+	if (tty) {
+		tty_flip_buffer_push(t);
+		tty_kref_put(tty);
+	}
+
+	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
+
+finish:
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	unsigned int ufcon, ufstat, uerstat;
+	unsigned int fifocnt = 0;
+	int max_count = port->fifosize;
+	u8 ch, flag;
+
+	while (max_count-- > 0) {
+		/*
+		 * Receive all characters known to be in FIFO
+		 * before reading FIFO level again
+		 */
+		if (fifocnt == 0) {
+			ufstat = rd_regl(port, S3C2410_UFSTAT);
+			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
+			if (fifocnt == 0)
+				break;
+		}
+		fifocnt--;
+
+		uerstat = rd_regl(port, S3C2410_UERSTAT);
+		ch = rd_reg(port, S3C2410_URXH);
+
+		if (port->flags & UPF_CONS_FLOW) {
+			int txe = s3c24xx_serial_txempty_nofifo(port);
+
+			if (ourport->rx_enabled) {
+				if (!txe) {
+					ourport->rx_enabled = 0;
+					continue;
+				}
+			} else {
+				if (txe) {
+					ufcon = rd_regl(port, S3C2410_UFCON);
+					ufcon |= S3C2410_UFCON_RESETRX;
+					wr_regl(port, S3C2410_UFCON, ufcon);
+					ourport->rx_enabled = 1;
+					return;
+				}
+				continue;
+			}
+		}
+
+		/* insert the character into the buffer */
+
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
+			dev_dbg(port->dev,
+				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
+				ch, uerstat);
+
+			/* check for break */
+			if (uerstat & S3C2410_UERSTAT_BREAK) {
+				dev_dbg(port->dev, "break!\n");
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue; /* Ignore character */
+			}
+
+			if (uerstat & S3C2410_UERSTAT_FRAME)
+				port->icount.frame++;
+			if (uerstat & S3C2410_UERSTAT_OVERRUN)
+				port->icount.overrun++;
+
+			uerstat &= port->read_status_mask;
+
+			if (uerstat & S3C2410_UERSTAT_BREAK)
+				flag = TTY_BREAK;
+			else if (uerstat & S3C2410_UERSTAT_PARITY)
+				flag = TTY_PARITY;
+			else if (uerstat & (S3C2410_UERSTAT_FRAME |
+					    S3C2410_UERSTAT_OVERRUN))
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue; /* Ignore character */
+
+		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
+				 ch, flag);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
+{
+	struct s3c24xx_uart_port *ourport = dev_id;
+	struct uart_port *port = &ourport->port;
+
+	spin_lock(&port->lock);
+	s3c24xx_serial_rx_drain_fifo(ourport);
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
+{
+	struct s3c24xx_uart_port *ourport = dev_id;
+
+	if (ourport->dma && ourport->dma->rx_chan)
+		return s3c24xx_serial_rx_chars_dma(dev_id);
+	return s3c24xx_serial_rx_chars_pio(dev_id);
+}
+
+static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	int count, dma_count = 0;
+
+	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	if (ourport->dma && ourport->dma->tx_chan &&
+	    count >= ourport->min_dma_size) {
+		int align = dma_get_cache_alignment() -
+			(xmit->tail & (dma_get_cache_alignment() - 1));
+		if (count - align >= ourport->min_dma_size) {
+			dma_count = count - align;
+			count = align;
+		}
+	}
+
+	if (port->x_char) {
+		wr_reg(port, S3C2410_UTXH, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	/* if there isn't anything more to transmit, or the uart is now
+	 * stopped, disable the uart and exit
+	 */
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		s3c24xx_serial_stop_tx(port);
+		return;
+	}
+
+	/* try and drain the buffer... */
+
+	if (count > port->fifosize) {
+		count = port->fifosize;
+		dma_count = 0;
+	}
+
+	while (!uart_circ_empty(xmit) && count > 0) {
+		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
+			break;
+
+		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
+		uart_xmit_advance(port, 1);
+		count--;
+	}
+
+	if (!count && dma_count) {
+		s3c24xx_serial_start_tx_dma(ourport, dma_count);
+		return;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		s3c24xx_serial_stop_tx(port);
+}
+
+static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
+{
+	struct s3c24xx_uart_port *ourport = id;
+	struct uart_port *port = &ourport->port;
+
+	spin_lock(&port->lock);
+
+	s3c24xx_serial_tx_chars(ourport);
+
+	spin_unlock(&port->lock);
+	return IRQ_HANDLED;
+}
+
+/* interrupt handler for s3c64xx and later SoC's.*/
+static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
+{
+	const struct s3c24xx_uart_port *ourport = id;
+	const struct uart_port *port = &ourport->port;
+	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
+	irqreturn_t ret = IRQ_HANDLED;
+
+	if (pend & S3C64XX_UINTM_RXD_MSK) {
+		ret = s3c24xx_serial_rx_irq(irq, id);
+		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
+	}
+	if (pend & S3C64XX_UINTM_TXD_MSK) {
+		ret = s3c24xx_serial_tx_irq(irq, id);
+		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
+	}
+	return ret;
+}
+
+/* interrupt handler for Apple SoC's.*/
+static irqreturn_t apple_serial_handle_irq(int irq, void *id)
+{
+	const struct s3c24xx_uart_port *ourport = id;
+	const struct uart_port *port = &ourport->port;
+	unsigned int pend = rd_regl(port, S3C2410_UTRSTAT);
+	irqreturn_t ret = IRQ_NONE;
+
+	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
+		wr_regl(port, S3C2410_UTRSTAT,
+			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
+		ret = s3c24xx_serial_rx_irq(irq, id);
+	}
+	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
+		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
+		ret = s3c24xx_serial_tx_irq(irq, id);
+	}
+
+	return ret;
+}
+
+static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
+	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
+
+	if (ufcon & S3C2410_UFCON_FIFOMODE) {
+		if ((ufstat & info->tx_fifomask) != 0 ||
+		    (ufstat & info->tx_fifofull))
+			return 0;
+
+		return 1;
+	}
+
+	return s3c24xx_serial_txempty_nofifo(port);
+}
+
+/* no modem control lines */
+static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
+{
+	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
+
+	if (umstat & S3C2410_UMSTAT_CTS)
+		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+	else
+		return TIOCM_CAR | TIOCM_DSR;
+}
+
+static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
+	unsigned int ucon = rd_regl(port, S3C2410_UCON);
+
+	if (mctrl & TIOCM_RTS)
+		umcon |= S3C2410_UMCOM_RTS_LOW;
+	else
+		umcon &= ~S3C2410_UMCOM_RTS_LOW;
+
+	wr_regl(port, S3C2410_UMCON, umcon);
+
+	if (mctrl & TIOCM_LOOP)
+		ucon |= S3C2410_UCON_LOOPBACK;
+	else
+		ucon &= ~S3C2410_UCON_LOOPBACK;
+
+	wr_regl(port, S3C2410_UCON, ucon);
+}
+
+static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+	unsigned int ucon;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	ucon = rd_regl(port, S3C2410_UCON);
+
+	if (break_state)
+		ucon |= S3C2410_UCON_SBREAK;
+	else
+		ucon &= ~S3C2410_UCON_SBREAK;
+
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
+{
+	struct s3c24xx_uart_dma	*dma = p->dma;
+	struct dma_slave_caps dma_caps;
+	const char *reason = NULL;
+	int ret;
+
+	/* Default slave configuration parameters */
+	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
+	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
+	dma->rx_conf.src_maxburst	= 1;
+
+	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
+	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
+	dma->tx_conf.dst_maxburst	= 1;
+
+	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
+
+	if (IS_ERR(dma->rx_chan)) {
+		reason = "DMA RX channel request failed";
+		ret = PTR_ERR(dma->rx_chan);
+		goto err_warn;
+	}
+
+	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
+	if (ret < 0 ||
+	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
+		reason = "insufficient DMA RX engine capabilities";
+		ret = -EOPNOTSUPP;
+		goto err_release_rx;
+	}
+
+	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
+
+	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
+	if (IS_ERR(dma->tx_chan)) {
+		reason = "DMA TX channel request failed";
+		ret = PTR_ERR(dma->tx_chan);
+		goto err_release_rx;
+	}
+
+	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
+	if (ret < 0 ||
+	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
+		reason = "insufficient DMA TX engine capabilities";
+		ret = -EOPNOTSUPP;
+		goto err_release_tx;
+	}
+
+	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
+
+	/* RX buffer */
+	dma->rx_size = PAGE_SIZE;
+
+	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
+	if (!dma->rx_buf) {
+		ret = -ENOMEM;
+		goto err_release_tx;
+	}
+
+	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
+				      dma->rx_size, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
+		reason = "DMA mapping error for RX buffer";
+		ret = -EIO;
+		goto err_free_rx;
+	}
+
+	/* TX buffer */
+	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
+				      p->port.state->xmit.buf, UART_XMIT_SIZE,
+				      DMA_TO_DEVICE);
+	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
+		reason = "DMA mapping error for TX buffer";
+		ret = -EIO;
+		goto err_unmap_rx;
+	}
+
+	return 0;
+
+err_unmap_rx:
+	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
+			 dma->rx_size, DMA_FROM_DEVICE);
+err_free_rx:
+	kfree(dma->rx_buf);
+err_release_tx:
+	dma_release_channel(dma->tx_chan);
+err_release_rx:
+	dma_release_channel(dma->rx_chan);
+err_warn:
+	if (reason)
+		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
+	return ret;
+}
+
+static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
+{
+	struct s3c24xx_uart_dma	*dma = p->dma;
+
+	if (dma->rx_chan) {
+		dmaengine_terminate_all(dma->rx_chan);
+		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
+				 dma->rx_size, DMA_FROM_DEVICE);
+		kfree(dma->rx_buf);
+		dma_release_channel(dma->rx_chan);
+		dma->rx_chan = NULL;
+	}
+
+	if (dma->tx_chan) {
+		dmaengine_terminate_all(dma->tx_chan);
+		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
+				 UART_XMIT_SIZE, DMA_TO_DEVICE);
+		dma_release_channel(dma->tx_chan);
+		dma->tx_chan = NULL;
+	}
+}
+
+static void s3c24xx_serial_shutdown(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	if (ourport->tx_claimed) {
+		free_irq(ourport->tx_irq, ourport);
+		ourport->tx_enabled = 0;
+		ourport->tx_claimed = 0;
+		ourport->tx_mode = 0;
+	}
+
+	if (ourport->rx_claimed) {
+		free_irq(ourport->rx_irq, ourport);
+		ourport->rx_claimed = 0;
+		ourport->rx_enabled = 0;
+	}
+
+	if (ourport->dma)
+		s3c24xx_serial_release_dma(ourport);
+
+	ourport->tx_in_progress = 0;
+}
+
+static void s3c64xx_serial_shutdown(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	ourport->tx_enabled = 0;
+	ourport->tx_mode = 0;
+	ourport->rx_enabled = 0;
+
+	free_irq(port->irq, ourport);
+
+	wr_regl(port, S3C64XX_UINTP, 0xf);
+	wr_regl(port, S3C64XX_UINTM, 0xf);
+
+	if (ourport->dma)
+		s3c24xx_serial_release_dma(ourport);
+
+	ourport->tx_in_progress = 0;
+}
+
+static void apple_s5l_serial_shutdown(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	unsigned int ucon;
+
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
+		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
+		  APPLE_S5L_UCON_RXTO_ENA_MSK);
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
+
+	free_irq(port->irq, ourport);
+
+	ourport->tx_enabled = 0;
+	ourport->tx_mode = 0;
+	ourport->rx_enabled = 0;
+
+	if (ourport->dma)
+		s3c24xx_serial_release_dma(ourport);
+
+	ourport->tx_in_progress = 0;
+}
+
+static int s3c24xx_serial_startup(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	int ret;
+
+	ourport->rx_enabled = 1;
+
+	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,
+			  s3c24xx_serial_portname(port), ourport);
+
+	if (ret != 0) {
+		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
+		return ret;
+	}
+
+	ourport->rx_claimed = 1;
+
+	dev_dbg(port->dev, "requesting tx irq...\n");
+
+	ourport->tx_enabled = 1;
+
+	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,
+			  s3c24xx_serial_portname(port), ourport);
+
+	if (ret) {
+		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
+		goto err;
+	}
+
+	ourport->tx_claimed = 1;
+
+	/* the port reset code should have done the correct
+	 * register setup for the port controls
+	 */
+
+	return ret;
+
+err:
+	s3c24xx_serial_shutdown(port);
+	return ret;
+}
+
+static int s3c64xx_serial_startup(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	unsigned long flags;
+	unsigned int ufcon;
+	int ret;
+
+	wr_regl(port, S3C64XX_UINTM, 0xf);
+	if (ourport->dma) {
+		ret = s3c24xx_serial_request_dma(ourport);
+		if (ret < 0) {
+			devm_kfree(port->dev, ourport->dma);
+			ourport->dma = NULL;
+		}
+	}
+
+	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
+			  s3c24xx_serial_portname(port), ourport);
+	if (ret) {
+		dev_err(port->dev, "cannot get irq %d\n", port->irq);
+		return ret;
+	}
+
+	/* For compatibility with s3c24xx Soc's */
+	ourport->rx_enabled = 1;
+	ourport->tx_enabled = 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	ufcon = rd_regl(port, S3C2410_UFCON);
+	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
+	if (!uart_console(port))
+		ufcon |= S3C2410_UFCON_RESETTX;
+	wr_regl(port, S3C2410_UFCON, ufcon);
+
+	enable_rx_pio(ourport);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Enable Rx Interrupt */
+	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
+
+	return ret;
+}
+
+static int apple_s5l_serial_startup(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	unsigned long flags;
+	unsigned int ufcon;
+	int ret;
+
+	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
+
+	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
+			  s3c24xx_serial_portname(port), ourport);
+	if (ret) {
+		dev_err(port->dev, "cannot get irq %d\n", port->irq);
+		return ret;
+	}
+
+	/* For compatibility with s3c24xx Soc's */
+	ourport->rx_enabled = 1;
+	ourport->tx_enabled = 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	ufcon = rd_regl(port, S3C2410_UFCON);
+	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
+	if (!uart_console(port))
+		ufcon |= S3C2410_UFCON_RESETTX;
+	wr_regl(port, S3C2410_UFCON, ufcon);
+
+	enable_rx_pio(ourport);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Enable Rx Interrupt */
+	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
+	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
+
+	return ret;
+}
+
+/* power power management control */
+
+static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
+			      unsigned int old)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	int timeout = 10000;
+
+	ourport->pm_level = level;
+
+	switch (level) {
+	case 3:
+		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
+			udelay(100);
+
+		if (!IS_ERR(ourport->baudclk))
+			clk_disable_unprepare(ourport->baudclk);
+
+		clk_disable_unprepare(ourport->clk);
+		break;
+
+	case 0:
+		clk_prepare_enable(ourport->clk);
+
+		if (!IS_ERR(ourport->baudclk))
+			clk_prepare_enable(ourport->baudclk);
+		break;
+	default:
+		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
+	}
+}
+
+/* baud rate calculation
+ *
+ * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
+ * of different sources, including the peripheral clock ("pclk") and an
+ * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
+ * with a programmable extra divisor.
+ *
+ * The following code goes through the clock sources, and calculates the
+ * baud clocks (and the resultant actual baud rates) and then tries to
+ * pick the closest one and select that.
+ *
+ */
+
+#define MAX_CLK_NAME_LENGTH 15
+
+static inline int s3c24xx_serial_getsource(struct uart_port *port)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+	unsigned int ucon;
+
+	if (info->num_clks == 1)
+		return 0;
+
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= info->clksel_mask;
+	return ucon >> info->clksel_shift;
+}
+
+static void s3c24xx_serial_setsource(struct uart_port *port,
+			unsigned int clk_sel)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+	unsigned int ucon;
+
+	if (info->num_clks == 1)
+		return;
+
+	ucon = rd_regl(port, S3C2410_UCON);
+	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
+		return;
+
+	ucon &= ~info->clksel_mask;
+	ucon |= clk_sel << info->clksel_shift;
+	wr_regl(port, S3C2410_UCON, ucon);
+}
+
+static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
+			unsigned int req_baud, struct clk **best_clk,
+			unsigned int *clk_num)
+{
+	const struct s3c24xx_uart_info *info = ourport->info;
+	struct clk *clk;
+	unsigned long rate;
+	unsigned int cnt, baud, quot, best_quot = 0;
+	char clkname[MAX_CLK_NAME_LENGTH];
+	int calc_deviation, deviation = (1 << 30) - 1;
+
+	for (cnt = 0; cnt < info->num_clks; cnt++) {
+		/* Keep selected clock if provided */
+		if (ourport->cfg->clk_sel &&
+			!(ourport->cfg->clk_sel & (1 << cnt)))
+			continue;
+
+		sprintf(clkname, "clk_uart_baud%d", cnt);
+		clk = clk_get(ourport->port.dev, clkname);
+		if (IS_ERR(clk))
+			continue;
+
+		rate = clk_get_rate(clk);
+		if (!rate) {
+			dev_err(ourport->port.dev,
+				"Failed to get clock rate for %s.\n", clkname);
+			clk_put(clk);
+			continue;
+		}
+
+		if (ourport->info->has_divslot) {
+			unsigned long div = rate / req_baud;
+
+			/* The UDIVSLOT register on the newer UARTs allows us to
+			 * get a divisor adjustment of 1/16th on the baud clock.
+			 *
+			 * We don't keep the UDIVSLOT value (the 16ths we
+			 * calculated by not multiplying the baud by 16) as it
+			 * is easy enough to recalculate.
+			 */
+
+			quot = div / 16;
+			baud = rate / div;
+		} else {
+			quot = (rate + (8 * req_baud)) / (16 * req_baud);
+			baud = rate / (quot * 16);
+		}
+		quot--;
+
+		calc_deviation = abs(req_baud - baud);
+
+		if (calc_deviation < deviation) {
+			/*
+			 * If we find a better clk, release the previous one, if
+			 * any.
+			 */
+			if (!IS_ERR(*best_clk))
+				clk_put(*best_clk);
+			*best_clk = clk;
+			best_quot = quot;
+			*clk_num = cnt;
+			deviation = calc_deviation;
+		} else {
+			clk_put(clk);
+		}
+	}
+
+	return best_quot;
+}
+
+/* udivslot_table[]
+ *
+ * This table takes the fractional value of the baud divisor and gives
+ * the recommended setting for the UDIVSLOT register.
+ */
+static const u16 udivslot_table[16] = {
+	[0] = 0x0000,
+	[1] = 0x0080,
+	[2] = 0x0808,
+	[3] = 0x0888,
+	[4] = 0x2222,
+	[5] = 0x4924,
+	[6] = 0x4A52,
+	[7] = 0x54AA,
+	[8] = 0x5555,
+	[9] = 0xD555,
+	[10] = 0xD5D5,
+	[11] = 0xDDD5,
+	[12] = 0xDDDD,
+	[13] = 0xDFDD,
+	[14] = 0xDFDF,
+	[15] = 0xFFDF,
+};
+
+static void s3c24xx_serial_set_termios(struct uart_port *port,
+				       struct ktermios *termios,
+				       const struct ktermios *old)
+{
+	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct clk *clk = ERR_PTR(-EINVAL);
+	unsigned long flags;
+	unsigned int baud, quot, clk_sel = 0;
+	unsigned int ulcon;
+	unsigned int umcon;
+	unsigned int udivslot = 0;
+
+	/*
+	 * We don't support modem control lines.
+	 */
+	termios->c_cflag &= ~(HUPCL | CMSPAR);
+	termios->c_cflag |= CLOCAL;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+
+	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
+	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
+	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
+		quot = port->custom_divisor;
+	if (IS_ERR(clk))
+		return;
+
+	/* check to see if we need  to change clock source */
+
+	if (ourport->baudclk != clk) {
+		clk_prepare_enable(clk);
+
+		s3c24xx_serial_setsource(port, clk_sel);
+
+		if (!IS_ERR(ourport->baudclk)) {
+			clk_disable_unprepare(ourport->baudclk);
+			ourport->baudclk = ERR_PTR(-EINVAL);
+		}
+
+		ourport->baudclk = clk;
+		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
+	}
+
+	if (ourport->info->has_divslot) {
+		unsigned int div = ourport->baudclk_rate / baud;
+
+		if (cfg->has_fracval) {
+			udivslot = (div & 15);
+			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
+		} else {
+			udivslot = udivslot_table[div & 15];
+			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
+				udivslot, div & 15);
+		}
+	}
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		dev_dbg(port->dev, "config: 5bits/char\n");
+		ulcon = S3C2410_LCON_CS5;
+		break;
+	case CS6:
+		dev_dbg(port->dev, "config: 6bits/char\n");
+		ulcon = S3C2410_LCON_CS6;
+		break;
+	case CS7:
+		dev_dbg(port->dev, "config: 7bits/char\n");
+		ulcon = S3C2410_LCON_CS7;
+		break;
+	case CS8:
+	default:
+		dev_dbg(port->dev, "config: 8bits/char\n");
+		ulcon = S3C2410_LCON_CS8;
+		break;
+	}
+
+	/* preserve original lcon IR settings */
+	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
+
+	if (termios->c_cflag & CSTOPB)
+		ulcon |= S3C2410_LCON_STOPB;
+
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & PARODD)
+			ulcon |= S3C2410_LCON_PODD;
+		else
+			ulcon |= S3C2410_LCON_PEVEN;
+	} else {
+		ulcon |= S3C2410_LCON_PNONE;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	dev_dbg(port->dev,
+		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
+		ulcon, quot, udivslot);
+
+	wr_regl(port, S3C2410_ULCON, ulcon);
+	wr_regl(port, S3C2410_UBRDIV, quot);
+
+	port->status &= ~UPSTAT_AUTOCTS;
+
+	umcon = rd_regl(port, S3C2410_UMCON);
+	if (termios->c_cflag & CRTSCTS) {
+		umcon |= S3C2410_UMCOM_AFC;
+		/* Disable RTS when RX FIFO contains 63 bytes */
+		umcon &= ~S3C2412_UMCON_AFC_8;
+		port->status = UPSTAT_AUTOCTS;
+	} else {
+		umcon &= ~S3C2410_UMCOM_AFC;
+	}
+	wr_regl(port, S3C2410_UMCON, umcon);
+
+	if (ourport->info->has_divslot)
+		wr_regl(port, S3C2443_DIVSLOT, udivslot);
+
+	dev_dbg(port->dev,
+		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
+		rd_regl(port, S3C2410_ULCON),
+		rd_regl(port, S3C2410_UCON),
+		rd_regl(port, S3C2410_UFCON));
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * Which character status flags are we interested in?
+	 */
+	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
+			S3C2410_UERSTAT_PARITY;
+	/*
+	 * Which character status flags should we ignore?
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
+	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *s3c24xx_serial_type(struct uart_port *port)
+{
+	const struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	switch (ourport->info->type) {
+	case TYPE_S3C24XX:
+		return "S3C24XX";
+	case TYPE_S3C6400:
+		return "S3C6400/10";
+	case TYPE_APPLE_S5L:
+		return "APPLE S5L";
+	default:
+		return NULL;
+	}
+}
+
+static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+
+	if (flags & UART_CONFIG_TYPE)
+		port->type = info->port_type;
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int
+s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+
+	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
+		return -EINVAL;
+
+	return 0;
+}
+
+#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
+
+static struct console s3c24xx_serial_console;
+
+static void __init s3c24xx_serial_register_console(void)
+{
+	register_console(&s3c24xx_serial_console);
+}
+
+static void s3c24xx_serial_unregister_console(void)
+{
+	if (console_is_registered(&s3c24xx_serial_console))
+		unregister_console(&s3c24xx_serial_console);
+}
+
+#define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
+#else
+static inline void s3c24xx_serial_register_console(void) { }
+static inline void s3c24xx_serial_unregister_console(void) { }
+#define S3C24XX_SERIAL_CONSOLE NULL
+#endif
+
+#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
+static int s3c24xx_serial_get_poll_char(struct uart_port *port);
+static void s3c24xx_serial_put_poll_char(struct uart_port *port,
+			 unsigned char c);
+#endif
+
+static const struct uart_ops s3c24xx_serial_ops = {
+	.pm		= s3c24xx_serial_pm,
+	.tx_empty	= s3c24xx_serial_tx_empty,
+	.get_mctrl	= s3c24xx_serial_get_mctrl,
+	.set_mctrl	= s3c24xx_serial_set_mctrl,
+	.stop_tx	= s3c24xx_serial_stop_tx,
+	.start_tx	= s3c24xx_serial_start_tx,
+	.stop_rx	= s3c24xx_serial_stop_rx,
+	.break_ctl	= s3c24xx_serial_break_ctl,
+	.startup	= s3c24xx_serial_startup,
+	.shutdown	= s3c24xx_serial_shutdown,
+	.set_termios	= s3c24xx_serial_set_termios,
+	.type		= s3c24xx_serial_type,
+	.config_port	= s3c24xx_serial_config_port,
+	.verify_port	= s3c24xx_serial_verify_port,
+#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
+	.poll_get_char = s3c24xx_serial_get_poll_char,
+	.poll_put_char = s3c24xx_serial_put_poll_char,
+#endif
+};
+
+static const struct uart_ops s3c64xx_serial_ops = {
+	.pm		= s3c24xx_serial_pm,
+	.tx_empty	= s3c24xx_serial_tx_empty,
+	.get_mctrl	= s3c24xx_serial_get_mctrl,
+	.set_mctrl	= s3c24xx_serial_set_mctrl,
+	.stop_tx	= s3c24xx_serial_stop_tx,
+	.start_tx	= s3c24xx_serial_start_tx,
+	.stop_rx	= s3c24xx_serial_stop_rx,
+	.break_ctl	= s3c24xx_serial_break_ctl,
+	.startup	= s3c64xx_serial_startup,
+	.shutdown	= s3c64xx_serial_shutdown,
+	.set_termios	= s3c24xx_serial_set_termios,
+	.type		= s3c24xx_serial_type,
+	.config_port	= s3c24xx_serial_config_port,
+	.verify_port	= s3c24xx_serial_verify_port,
+#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
+	.poll_get_char = s3c24xx_serial_get_poll_char,
+	.poll_put_char = s3c24xx_serial_put_poll_char,
+#endif
+};
+
+static const struct uart_ops apple_s5l_serial_ops = {
+	.pm		= s3c24xx_serial_pm,
+	.tx_empty	= s3c24xx_serial_tx_empty,
+	.get_mctrl	= s3c24xx_serial_get_mctrl,
+	.set_mctrl	= s3c24xx_serial_set_mctrl,
+	.stop_tx	= s3c24xx_serial_stop_tx,
+	.start_tx	= s3c24xx_serial_start_tx,
+	.stop_rx	= s3c24xx_serial_stop_rx,
+	.break_ctl	= s3c24xx_serial_break_ctl,
+	.startup	= apple_s5l_serial_startup,
+	.shutdown	= apple_s5l_serial_shutdown,
+	.set_termios	= s3c24xx_serial_set_termios,
+	.type		= s3c24xx_serial_type,
+	.config_port	= s3c24xx_serial_config_port,
+	.verify_port	= s3c24xx_serial_verify_port,
+#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
+	.poll_get_char = s3c24xx_serial_get_poll_char,
+	.poll_put_char = s3c24xx_serial_put_poll_char,
+#endif
+};
+
+static struct uart_driver s3c24xx_uart_drv = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "s3c2410_serial",
+	.nr		= UART_NR,
+	.cons		= S3C24XX_SERIAL_CONSOLE,
+	.dev_name	= S3C24XX_SERIAL_NAME,
+	.major		= S3C24XX_SERIAL_MAJOR,
+	.minor		= S3C24XX_SERIAL_MINOR,
+};
+
+static struct s3c24xx_uart_port s3c24xx_serial_ports[UART_NR];
+
+static void s3c24xx_serial_init_port_default(int index) {
+	struct uart_port *port = &s3c24xx_serial_ports[index].port;
+
+	spin_lock_init(&port->lock);
+
+	port->iotype = UPIO_MEM;
+	port->uartclk = 0;
+	port->fifosize = 16;
+	port->ops = &s3c24xx_serial_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->line = index;
+}
+
+/* s3c24xx_serial_resetport
+ *
+ * reset the fifos and other the settings.
+ */
+
+static void s3c24xx_serial_resetport(struct uart_port *port,
+				     const struct s3c2410_uartcfg *cfg)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+	unsigned long ucon = rd_regl(port, S3C2410_UCON);
+
+	ucon &= (info->clksel_mask | info->ucon_mask);
+	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
+
+	/* reset both fifos */
+	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
+	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
+
+	/* some delay is required after fifo reset */
+	udelay(1);
+}
+
+static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
+{
+	struct device *dev = ourport->port.dev;
+	const struct s3c24xx_uart_info *info = ourport->info;
+	char clk_name[MAX_CLK_NAME_LENGTH];
+	unsigned int clk_sel;
+	struct clk *clk;
+	int clk_num;
+	int ret;
+
+	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
+	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
+		if (!(clk_sel & (1 << clk_num)))
+			continue;
+
+		sprintf(clk_name, "clk_uart_baud%d", clk_num);
+		clk = clk_get(dev, clk_name);
+		if (IS_ERR(clk))
+			continue;
+
+		ret = clk_prepare_enable(clk);
+		if (ret) {
+			clk_put(clk);
+			continue;
+		}
+
+		ourport->baudclk = clk;
+		ourport->baudclk_rate = clk_get_rate(clk);
+		s3c24xx_serial_setsource(&ourport->port, clk_num);
+
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/* s3c24xx_serial_init_port
+ *
+ * initialise a single serial port from the platform device given
+ */
+
+static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
+				    struct platform_device *platdev)
+{
+	struct uart_port *port = &ourport->port;
+	const struct s3c2410_uartcfg *cfg = ourport->cfg;
+	struct resource *res;
+	int ret;
+
+	if (platdev == NULL)
+		return -ENODEV;
+
+	if (port->mapbase != 0)
+		return -EINVAL;
+
+	/* setup info for port */
+	port->dev	= &platdev->dev;
+
+	port->uartclk = 1;
+
+	if (cfg->uart_flags & UPF_CONS_FLOW) {
+		dev_dbg(port->dev, "enabling flow control\n");
+		port->flags |= UPF_CONS_FLOW;
+	}
+
+	/* sort our the physical and virtual addresses for each UART */
+
+	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(port->dev, "failed to find memory resource for uart\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(port->dev, "resource %pR)\n", res);
+
+	port->membase = devm_ioremap_resource(port->dev, res);
+	if (IS_ERR(port->membase)) {
+		dev_err(port->dev, "failed to remap controller address\n");
+		return -EBUSY;
+	}
+
+	port->mapbase = res->start;
+	ret = platform_get_irq(platdev, 0);
+	if (ret < 0) {
+		port->irq = 0;
+	} else {
+		port->irq = ret;
+		ourport->rx_irq = ret;
+		ourport->tx_irq = ret + 1;
+	}
+
+	switch (ourport->info->type) {
+	case TYPE_S3C24XX:
+		ret = platform_get_irq(platdev, 1);
+		if (ret > 0)
+			ourport->tx_irq = ret;
+		break;
+	default:
+		break;
+	}
+
+	/*
+	 * DMA is currently supported only on DT platforms, if DMA properties
+	 * are specified.
+	 */
+	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
+						     "dmas", NULL)) {
+		ourport->dma = devm_kzalloc(port->dev,
+					    sizeof(*ourport->dma),
+					    GFP_KERNEL);
+		if (!ourport->dma) {
+			ret = -ENOMEM;
+			goto err;
+		}
+	}
+
+	ourport->clk	= clk_get(&platdev->dev, "uart");
+	if (IS_ERR(ourport->clk)) {
+		pr_err("%s: Controller clock not found\n",
+				dev_name(&platdev->dev));
+		ret = PTR_ERR(ourport->clk);
+		goto err;
+	}
+
+	ret = clk_prepare_enable(ourport->clk);
+	if (ret) {
+		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
+		clk_put(ourport->clk);
+		goto err;
+	}
+
+	ret = s3c24xx_serial_enable_baudclk(ourport);
+	if (ret)
+		pr_warn("uart: failed to enable baudclk\n");
+
+	/* Keep all interrupts masked and cleared */
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
+		wr_regl(port, S3C64XX_UINTM, 0xf);
+		wr_regl(port, S3C64XX_UINTP, 0xf);
+		wr_regl(port, S3C64XX_UINTSP, 0xf);
+		break;
+	case TYPE_APPLE_S5L: {
+		unsigned int ucon;
+
+		ucon = rd_regl(port, S3C2410_UCON);
+		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
+			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
+			APPLE_S5L_UCON_RXTO_ENA_MSK);
+		wr_regl(port, S3C2410_UCON, ucon);
+
+		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
+		break;
+	}
+	default:
+		break;
+	}
+
+	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
+		&port->mapbase, port->membase, port->irq,
+		ourport->rx_irq, ourport->tx_irq, port->uartclk);
+
+	/* reset the fifos (and setup the uart) */
+	s3c24xx_serial_resetport(port, cfg);
+
+	return 0;
+
+err:
+	port->mapbase = 0;
+	return ret;
+}
+
+/* Device driver serial port probe */
+
+static int probe_index;
+
+static inline const struct s3c24xx_serial_drv_data *
+s3c24xx_get_driver_data(struct platform_device *pdev)
+{
+	if (dev_of_node(&pdev->dev))
+		return of_device_get_match_data(&pdev->dev);
+
+	return (struct s3c24xx_serial_drv_data *)
+			platform_get_device_id(pdev)->driver_data;
+}
+
+static int s3c24xx_serial_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct s3c24xx_uart_port *ourport;
+	int index = probe_index;
+	int ret, prop = 0;
+
+	if (np) {
+		ret = of_alias_get_id(np, "serial");
+		if (ret >= 0)
+			index = ret;
+	}
+
+	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n", index);
+		return -EINVAL;
+	}
+	ourport = &s3c24xx_serial_ports[index];
+
+	s3c24xx_serial_init_port_default(index);
+
+	ourport->drv_data = s3c24xx_get_driver_data(pdev);
+	if (!ourport->drv_data) {
+		dev_err(&pdev->dev, "could not find driver data\n");
+		return -ENODEV;
+	}
+
+	ourport->baudclk = ERR_PTR(-EINVAL);
+	ourport->info = &ourport->drv_data->info;
+	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
+			dev_get_platdata(&pdev->dev) :
+			&ourport->drv_data->def_cfg;
+
+	switch (ourport->info->type) {
+	case TYPE_S3C24XX:
+		ourport->port.ops = &s3c24xx_serial_ops;
+		break;
+	case TYPE_S3C6400:
+		ourport->port.ops = &s3c64xx_serial_ops;
+		break;
+	case TYPE_APPLE_S5L:
+		ourport->port.ops = &apple_s5l_serial_ops;
+		break;
+	}
+
+	if (np) {
+		of_property_read_u32(np,
+			"samsung,uart-fifosize", &ourport->port.fifosize);
+
+		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
+			switch (prop) {
+			case 1:
+				ourport->port.iotype = UPIO_MEM;
+				break;
+			case 4:
+				ourport->port.iotype = UPIO_MEM32;
+				break;
+			default:
+				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
+						prop);
+				return -EINVAL;
+			}
+		}
+	}
+
+	if (ourport->drv_data->fifosize[index])
+		ourport->port.fifosize = ourport->drv_data->fifosize[index];
+	else if (ourport->info->fifosize)
+		ourport->port.fifosize = ourport->info->fifosize;
+	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
+
+	/*
+	 * DMA transfers must be aligned at least to cache line size,
+	 * so find minimal transfer size suitable for DMA mode
+	 */
+	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
+				    dma_get_cache_alignment());
+
+	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
+
+	ret = s3c24xx_serial_init_port(ourport, pdev);
+	if (ret < 0)
+		return ret;
+
+	if (!s3c24xx_uart_drv.state) {
+		ret = uart_register_driver(&s3c24xx_uart_drv);
+		if (ret < 0) {
+			pr_err("Failed to register Samsung UART driver\n");
+			return ret;
+		}
+	}
+
+	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
+	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
+	platform_set_drvdata(pdev, &ourport->port);
+
+	/*
+	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
+	 * so that a potential re-enablement through the pm-callback overlaps
+	 * and keeps the clock enabled in this case.
+	 */
+	clk_disable_unprepare(ourport->clk);
+	if (!IS_ERR(ourport->baudclk))
+		clk_disable_unprepare(ourport->baudclk);
+
+	probe_index++;
+
+	return 0;
+}
+
+static int s3c24xx_serial_remove(struct platform_device *dev)
+{
+	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
+
+	if (port) {
+		uart_remove_one_port(&s3c24xx_uart_drv, port);
+	}
+
+	uart_unregister_driver(&s3c24xx_uart_drv);
+
+	return 0;
+}
+
+/* UART power management code */
+#ifdef CONFIG_PM_SLEEP
+static int s3c24xx_serial_suspend(struct device *dev)
+{
+	struct uart_port *port = s3c24xx_dev_to_port(dev);
+
+	if (port)
+		uart_suspend_port(&s3c24xx_uart_drv, port);
+
+	return 0;
+}
+
+static int s3c24xx_serial_resume(struct device *dev)
+{
+	struct uart_port *port = s3c24xx_dev_to_port(dev);
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	if (port) {
+		clk_prepare_enable(ourport->clk);
+		if (!IS_ERR(ourport->baudclk))
+			clk_prepare_enable(ourport->baudclk);
+		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
+		if (!IS_ERR(ourport->baudclk))
+			clk_disable_unprepare(ourport->baudclk);
+		clk_disable_unprepare(ourport->clk);
+
+		uart_resume_port(&s3c24xx_uart_drv, port);
+	}
+
+	return 0;
+}
+
+static int s3c24xx_serial_resume_noirq(struct device *dev)
+{
+	struct uart_port *port = s3c24xx_dev_to_port(dev);
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	if (port) {
+		/* restore IRQ mask */
+		switch (ourport->info->type) {
+		case TYPE_S3C6400: {
+			unsigned int uintm = 0xf;
+
+			if (ourport->tx_enabled)
+				uintm &= ~S3C64XX_UINTM_TXD_MSK;
+			if (ourport->rx_enabled)
+				uintm &= ~S3C64XX_UINTM_RXD_MSK;
+			clk_prepare_enable(ourport->clk);
+			if (!IS_ERR(ourport->baudclk))
+				clk_prepare_enable(ourport->baudclk);
+			wr_regl(port, S3C64XX_UINTM, uintm);
+			if (!IS_ERR(ourport->baudclk))
+				clk_disable_unprepare(ourport->baudclk);
+			clk_disable_unprepare(ourport->clk);
+			break;
+		}
+		case TYPE_APPLE_S5L: {
+			unsigned int ucon;
+			int ret;
+
+			ret = clk_prepare_enable(ourport->clk);
+			if (ret) {
+				dev_err(dev, "clk_enable clk failed: %d\n", ret);
+				return ret;
+			}
+			if (!IS_ERR(ourport->baudclk)) {
+				ret = clk_prepare_enable(ourport->baudclk);
+				if (ret) {
+					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
+					clk_disable_unprepare(ourport->clk);
+					return ret;
+				}
+			}
+
+			ucon = rd_regl(port, S3C2410_UCON);
+
+			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
+				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
+				  APPLE_S5L_UCON_RXTO_ENA_MSK);
+
+			if (ourport->tx_enabled)
+				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
+			if (ourport->rx_enabled)
+				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
+					APPLE_S5L_UCON_RXTO_ENA_MSK;
+
+			wr_regl(port, S3C2410_UCON, ucon);
+
+			if (!IS_ERR(ourport->baudclk))
+				clk_disable_unprepare(ourport->baudclk);
+			clk_disable_unprepare(ourport->clk);
+			break;
+		}
+		default:
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(s3c24xx_serial_suspend, s3c24xx_serial_resume)
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, s3c24xx_serial_resume_noirq)
+};
+#define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
+
+#else /* !CONFIG_PM_SLEEP */
+
+#define SERIAL_SAMSUNG_PM_OPS	NULL
+#endif /* CONFIG_PM_SLEEP */
+
+/* Console code */
+
+#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
+
+static struct uart_port *cons_uart;
+
+static int
+s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
+{
+	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
+	unsigned long ufstat, utrstat;
+
+	if (ufcon & S3C2410_UFCON_FIFOMODE) {
+		/* fifo mode - check amount of data in fifo registers... */
+
+		ufstat = rd_regl(port, S3C2410_UFSTAT);
+		return (ufstat & info->tx_fifofull) ? 0 : 1;
+	}
+
+	/* in non-fifo mode, we go and use the tx buffer empty */
+
+	utrstat = rd_regl(port, S3C2410_UTRSTAT);
+	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
+}
+
+static bool
+s3c24xx_port_configured(unsigned int ucon)
+{
+	/* consider the serial port configured if the tx/rx mode set */
+	return (ucon & 0xf) != 0;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int s3c24xx_serial_get_poll_char(struct uart_port *port)
+{
+	const struct s3c24xx_uart_port *ourport = to_ourport(port);
+	unsigned int ufstat;
+
+	ufstat = rd_regl(port, S3C2410_UFSTAT);
+	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
+		return NO_POLL_CHAR;
+
+	return rd_reg(port, S3C2410_URXH);
+}
+
+static void s3c24xx_serial_put_poll_char(struct uart_port *port,
+		unsigned char c)
+{
+	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
+	unsigned int ucon = rd_regl(port, S3C2410_UCON);
+
+	/* not possible to xmit on unconfigured port */
+	if (!s3c24xx_port_configured(ucon))
+		return;
+
+	while (!s3c24xx_serial_console_txrdy(port, ufcon))
+		cpu_relax();
+	wr_reg(port, S3C2410_UTXH, c);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static void
+s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
+
+	while (!s3c24xx_serial_console_txrdy(port, ufcon))
+		cpu_relax();
+	wr_reg(port, S3C2410_UTXH, ch);
+}
+
+static void
+s3c24xx_serial_console_write(struct console *co, const char *s,
+			     unsigned int count)
+{
+	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
+	unsigned long flags;
+	bool locked = true;
+
+	/* not possible to xmit on unconfigured port */
+	if (!s3c24xx_port_configured(ucon))
+		return;
+
+	if (cons_uart->sysrq)
+		locked = false;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&cons_uart->lock, flags);
+	else
+		spin_lock_irqsave(&cons_uart->lock, flags);
+
+	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
+
+	if (locked)
+		spin_unlock_irqrestore(&cons_uart->lock, flags);
+}
+
+/* Shouldn't be __init, as it can be instantiated from other module */
+static void
+s3c24xx_serial_get_options(struct uart_port *port, int *baud,
+			   int *parity, int *bits)
+{
+	struct clk *clk;
+	unsigned int ulcon;
+	unsigned int ucon;
+	unsigned int ubrdiv;
+	unsigned long rate;
+	unsigned int clk_sel;
+	char clk_name[MAX_CLK_NAME_LENGTH];
+
+	ulcon  = rd_regl(port, S3C2410_ULCON);
+	ucon   = rd_regl(port, S3C2410_UCON);
+	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
+
+	if (s3c24xx_port_configured(ucon)) {
+		switch (ulcon & S3C2410_LCON_CSMASK) {
+		case S3C2410_LCON_CS5:
+			*bits = 5;
+			break;
+		case S3C2410_LCON_CS6:
+			*bits = 6;
+			break;
+		case S3C2410_LCON_CS7:
+			*bits = 7;
+			break;
+		case S3C2410_LCON_CS8:
+		default:
+			*bits = 8;
+			break;
+		}
+
+		switch (ulcon & S3C2410_LCON_PMASK) {
+		case S3C2410_LCON_PEVEN:
+			*parity = 'e';
+			break;
+
+		case S3C2410_LCON_PODD:
+			*parity = 'o';
+			break;
+
+		case S3C2410_LCON_PNONE:
+		default:
+			*parity = 'n';
+		}
+
+		/* now calculate the baud rate */
+
+		clk_sel = s3c24xx_serial_getsource(port);
+		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
+
+		clk = clk_get(port->dev, clk_name);
+		if (!IS_ERR(clk))
+			rate = clk_get_rate(clk);
+		else
+			rate = 1;
+
+		*baud = rate / (16 * (ubrdiv + 1));
+		dev_dbg(port->dev, "calculated baud %d\n", *baud);
+	}
+}
+
+/* Shouldn't be __init, as it can be instantiated from other module */
+static int
+s3c24xx_serial_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/* is this a valid port */
+
+	if (co->index == -1 || co->index >= UART_NR)
+		co->index = 0;
+
+	port = &s3c24xx_serial_ports[co->index].port;
+
+	/* is the port configured? */
+
+	if (port->mapbase == 0x0)
+		return -ENODEV;
+
+	cons_uart = port;
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
+
+	dev_dbg(port->dev, "baud %d\n", baud);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console s3c24xx_serial_console = {
+	.name		= S3C24XX_SERIAL_NAME,
+	.device		= uart_console_device,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.write		= s3c24xx_serial_console_write,
+	.setup		= s3c24xx_serial_console_setup,
+	.data		= &s3c24xx_uart_drv,
+};
+#endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
+
+#if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
+static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
+	.info = {
+		.name		= "Samsung S3C6400 UART",
+		.type		= TYPE_S3C6400,
+		.port_type	= PORT_S3C6400,
+		.fifosize	= 64,
+		.has_divslot	= 1,
+		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
+		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
+		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
+		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
+		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
+		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
+		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
+		.num_clks	= 4,
+		.clksel_mask	= S3C6400_UCON_CLKMASK,
+		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
+	},
+	.def_cfg = {
+		.ucon		= S3C2410_UCON_DEFAULT,
+		.ufcon		= S3C2410_UFCON_DEFAULT,
+	},
+};
+#define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
+#else
+#define S3C6400_SERIAL_DRV_DATA NULL
+#endif
+
+#ifdef CONFIG_CPU_S5PV210
+static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
+	.info = {
+		.name		= "Samsung S5PV210 UART",
+		.type		= TYPE_S3C6400,
+		.port_type	= PORT_S3C6400,
+		.has_divslot	= 1,
+		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
+		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
+		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
+		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
+		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
+		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
+		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
+		.num_clks	= 2,
+		.clksel_mask	= S5PV210_UCON_CLKMASK,
+		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
+	},
+	.def_cfg = {
+		.ucon		= S5PV210_UCON_DEFAULT,
+		.ufcon		= S5PV210_UFCON_DEFAULT,
+	},
+	.fifosize = { 256, 64, 16, 16 },
+};
+#define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
+#else
+#define S5PV210_SERIAL_DRV_DATA	NULL
+#endif
+
+#if defined(CONFIG_ARCH_EXYNOS)
+#define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
+	.info = {						\
+		.name		= "Samsung Exynos UART",	\
+		.type		= TYPE_S3C6400,			\
+		.port_type	= PORT_S3C6400,			\
+		.has_divslot	= 1,				\
+		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
+		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
+		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
+		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
+		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
+		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
+		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
+		.num_clks	= 1,				\
+		.clksel_mask	= 0,				\
+		.clksel_shift	= 0,				\
+	},							\
+	.def_cfg = {						\
+		.ucon		= S5PV210_UCON_DEFAULT,		\
+		.ufcon		= S5PV210_UFCON_DEFAULT,	\
+		.has_fracval	= 1,				\
+	}							\
+
+static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
+	.fifosize = { 256, 64, 16, 16 },
+};
+
+static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
+	.fifosize = { 64, 256, 16, 256 },
+};
+
+static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
+	.fifosize = { 256, 64, 64, 64 },
+};
+
+#define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
+#define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
+#define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
+
+#else
+#define EXYNOS4210_SERIAL_DRV_DATA NULL
+#define EXYNOS5433_SERIAL_DRV_DATA NULL
+#define EXYNOS850_SERIAL_DRV_DATA NULL
+#endif
+
+#ifdef CONFIG_ARCH_APPLE
+static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
+	.info = {
+		.name		= "Apple S5L UART",
+		.type		= TYPE_APPLE_S5L,
+		.port_type	= PORT_8250,
+		.fifosize	= 16,
+		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
+		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
+		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
+		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
+		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
+		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
+		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
+		.num_clks	= 1,
+		.clksel_mask	= 0,
+		.clksel_shift	= 0,
+		.ucon_mask	= APPLE_S5L_UCON_MASK,
+	},
+	.def_cfg = {
+		.ucon		= APPLE_S5L_UCON_DEFAULT,
+		.ufcon		= S3C2410_UFCON_DEFAULT,
+	},
+};
+#define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
+#else
+#define S5L_SERIAL_DRV_DATA NULL
+#endif
+
+#if defined(CONFIG_ARCH_ARTPEC)
+static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
+	.info = {
+		.name		= "Axis ARTPEC-8 UART",
+		.type		= TYPE_S3C6400,
+		.port_type	= PORT_S3C6400,
+		.fifosize	= 64,
+		.has_divslot	= 1,
+		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
+		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
+		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
+		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
+		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
+		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
+		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
+		.num_clks	= 1,
+		.clksel_mask	= 0,
+		.clksel_shift	= 0,
+	},
+	.def_cfg = {
+		.ucon		= S5PV210_UCON_DEFAULT,
+		.ufcon		= S5PV210_UFCON_DEFAULT,
+		.has_fracval	= 1,
+	}
+};
+#define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
+#else
+#define ARTPEC8_SERIAL_DRV_DATA (NULL)
+#endif
+
+static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
+	{
+		.name		= "s3c6400-uart",
+		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
+	}, {
+		.name		= "s5pv210-uart",
+		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
+	}, {
+		.name		= "exynos4210-uart",
+		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
+	}, {
+		.name		= "exynos5433-uart",
+		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
+	}, {
+		.name		= "s5l-uart",
+		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
+	}, {
+		.name		= "exynos850-uart",
+		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
+	}, {
+		.name		= "artpec8-uart",
+		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
+
+#ifdef CONFIG_OF
+static const struct of_device_id s3c24xx_uart_dt_match[] = {
+	{ .compatible = "samsung,s3c6400-uart",
+		.data = S3C6400_SERIAL_DRV_DATA },
+	{ .compatible = "samsung,s5pv210-uart",
+		.data = S5PV210_SERIAL_DRV_DATA },
+	{ .compatible = "samsung,exynos4210-uart",
+		.data = EXYNOS4210_SERIAL_DRV_DATA },
+	{ .compatible = "samsung,exynos5433-uart",
+		.data = EXYNOS5433_SERIAL_DRV_DATA },
+	{ .compatible = "apple,s5l-uart",
+		.data = S5L_SERIAL_DRV_DATA },
+	{ .compatible = "samsung,exynos850-uart",
+		.data = EXYNOS850_SERIAL_DRV_DATA },
+	{ .compatible = "axis,artpec8-uart",
+		.data = ARTPEC8_SERIAL_DRV_DATA },
+	{},
+};
+MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
+#endif
+
+static struct platform_driver samsung_serial_driver = {
+	.probe		= s3c24xx_serial_probe,
+	.remove		= s3c24xx_serial_remove,
+	.id_table	= s3c24xx_serial_driver_ids,
+	.driver		= {
+		.name	= "samsung-uart",
+		.pm	= SERIAL_SAMSUNG_PM_OPS,
+		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
+	},
+};
+
+static int __init samsung_serial_init(void)
+{
+	int ret;
+
+	s3c24xx_serial_register_console();
+
+	ret = platform_driver_register(&samsung_serial_driver);
+	if (ret) {
+		s3c24xx_serial_unregister_console();
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit samsung_serial_exit(void)
+{
+	platform_driver_unregister(&samsung_serial_driver);
+	s3c24xx_serial_unregister_console();
+}
+
+module_init(samsung_serial_init);
+module_exit(samsung_serial_exit);
+
+#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
+/*
+ * Early console.
+ */
+
+static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
+{
+	switch (port->iotype) {
+	case UPIO_MEM:
+		writeb(val, portaddr(port, reg));
+		break;
+	case UPIO_MEM32:
+		writel(val, portaddr(port, reg));
+		break;
+	}
+}
+
+struct samsung_early_console_data {
+	u32 txfull_mask;
+	u32 rxfifo_mask;
+};
+
+static void samsung_early_busyuart(const struct uart_port *port)
+{
+	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
+		;
+}
+
+static void samsung_early_busyuart_fifo(const struct uart_port *port)
+{
+	const struct samsung_early_console_data *data = port->private_data;
+
+	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
+		;
+}
+
+static void samsung_early_putc(struct uart_port *port, unsigned char c)
+{
+	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
+		samsung_early_busyuart_fifo(port);
+	else
+		samsung_early_busyuart(port);
+
+	wr_reg_barrier(port, S3C2410_UTXH, c);
+}
+
+static void samsung_early_write(struct console *con, const char *s,
+				unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, samsung_early_putc);
+}
+
+static int samsung_early_read(struct console *con, char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+	const struct samsung_early_console_data *data = dev->port.private_data;
+	int ch, ufstat, num_read = 0;
+
+	while (num_read < n) {
+		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
+		if (!(ufstat & data->rxfifo_mask))
+			break;
+		ch = rd_reg(&dev->port, S3C2410_URXH);
+		if (ch == NO_POLL_CHAR)
+			break;
+
+		s[num_read++] = ch;
+	}
+
+	return num_read;
+}
+
+static int __init samsung_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = samsung_early_write;
+	device->con->read = samsung_early_read;
+	return 0;
+}
+
+/* S3C2410 */
+static struct samsung_early_console_data s3c2410_early_console_data = {
+	.txfull_mask = S3C2410_UFSTAT_TXFULL,
+	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
+};
+
+static int __init s3c2410_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	device->port.private_data = &s3c2410_early_console_data;
+	return samsung_early_console_setup(device, opt);
+}
+
+OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
+			s3c2410_early_console_setup);
+
+/* S3C2412, S3C2440, S3C64xx */
+static struct samsung_early_console_data s3c2440_early_console_data = {
+	.txfull_mask = S3C2440_UFSTAT_TXFULL,
+	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
+};
+
+static int __init s3c2440_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	device->port.private_data = &s3c2440_early_console_data;
+	return samsung_early_console_setup(device, opt);
+}
+
+OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
+			s3c2440_early_console_setup);
+OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
+			s3c2440_early_console_setup);
+OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
+			s3c2440_early_console_setup);
+
+/* S5PV210, Exynos */
+static struct samsung_early_console_data s5pv210_early_console_data = {
+	.txfull_mask = S5PV210_UFSTAT_TXFULL,
+	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
+};
+
+static int __init s5pv210_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	device->port.private_data = &s5pv210_early_console_data;
+	return samsung_early_console_setup(device, opt);
+}
+
+OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
+			s5pv210_early_console_setup);
+OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
+			s5pv210_early_console_setup);
+OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
+			s5pv210_early_console_setup);
+
+/* Apple S5L */
+static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
+						const char *opt)
+{
+	/* Close enough to S3C2410 for earlycon... */
+	device->port.private_data = &s3c2410_early_console_data;
+
+#ifdef CONFIG_ARM64
+	/* ... but we need to override the existing fixmap entry as nGnRnE */
+	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
+		     __pgprot(PROT_DEVICE_nGnRnE));
+#endif
+	return samsung_early_console_setup(device, opt);
+}
+
+OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
+#endif
+
+MODULE_ALIAS("platform:samsung-uart");
+MODULE_DESCRIPTION("Samsung SoC Serial port driver");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/sb1250-duart.c b/drivers/tty/serial/sb1250-duart.c
new file mode 100644
index 000000000..f3cd69346
--- /dev/null
+++ b/drivers/tty/serial/sb1250-duart.c
@@ -0,0 +1,964 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	Support for the asynchronous serial interface (DUART) included
+ *	in the BCM1250 and derived System-On-a-Chip (SOC) devices.
+ *
+ *	Copyright (c) 2007  Maciej W. Rozycki
+ *
+ *	Derived from drivers/char/sb1250_duart.c for which the following
+ *	copyright applies:
+ *
+ *	Copyright (c) 2000, 2001, 2002, 2003, 2004  Broadcom Corporation
+ *
+ *	References:
+ *
+ *	"BCM1250/BCM1125/BCM1125H User Manual", Broadcom Corporation
+ */
+
+#include <linux/compiler.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/major.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+
+#include <linux/refcount.h>
+#include <linux/io.h>
+
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_uart.h>
+#include <asm/sibyte/swarm.h>
+
+
+#if defined(CONFIG_SIBYTE_BCM1x80)
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/bcm1480_int.h>
+
+#define SBD_CHANREGS(line)	A_BCM1480_DUART_CHANREG((line), 0)
+#define SBD_CTRLREGS(line)	A_BCM1480_DUART_CTRLREG((line), 0)
+#define SBD_INT(line)		(K_BCM1480_INT_UART_0 + (line))
+
+#define DUART_CHANREG_SPACING	BCM1480_DUART_CHANREG_SPACING
+
+#define R_DUART_IMRREG(line)	R_BCM1480_DUART_IMRREG(line)
+#define R_DUART_INCHREG(line)	R_BCM1480_DUART_INCHREG(line)
+#define R_DUART_ISRREG(line)	R_BCM1480_DUART_ISRREG(line)
+
+#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+
+#define SBD_CHANREGS(line)	A_DUART_CHANREG((line), 0)
+#define SBD_CTRLREGS(line)	A_DUART_CTRLREG(0)
+#define SBD_INT(line)		(K_INT_UART_0 + (line))
+
+#else
+#error invalid SB1250 UART configuration
+
+#endif
+
+
+MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
+MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver");
+MODULE_LICENSE("GPL");
+
+
+#define DUART_MAX_CHIP 2
+#define DUART_MAX_SIDE 2
+
+/*
+ * Per-port state.
+ */
+struct sbd_port {
+	struct sbd_duart	*duart;
+	struct uart_port	port;
+	unsigned char __iomem	*memctrl;
+	int			tx_stopped;
+	int			initialised;
+};
+
+/*
+ * Per-DUART state for the shared register space.
+ */
+struct sbd_duart {
+	struct sbd_port		sport[2];
+	unsigned long		mapctrl;
+	refcount_t		map_guard;
+};
+
+#define to_sport(uport) container_of(uport, struct sbd_port, port)
+
+static struct sbd_duart sbd_duarts[DUART_MAX_CHIP];
+
+
+/*
+ * Reading and writing SB1250 DUART registers.
+ *
+ * There are three register spaces: two per-channel ones and
+ * a shared one.  We have to define accessors appropriately.
+ * All registers are 64-bit and all but the Baud Rate Clock
+ * registers only define 8 least significant bits.  There is
+ * also a workaround to take into account.  Raw accessors use
+ * the full register width, but cooked ones truncate it
+ * intentionally so that the rest of the driver does not care.
+ */
+static u64 __read_sbdchn(struct sbd_port *sport, int reg)
+{
+	void __iomem *csr = sport->port.membase + reg;
+
+	return __raw_readq(csr);
+}
+
+static u64 __read_sbdshr(struct sbd_port *sport, int reg)
+{
+	void __iomem *csr = sport->memctrl + reg;
+
+	return __raw_readq(csr);
+}
+
+static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value)
+{
+	void __iomem *csr = sport->port.membase + reg;
+
+	__raw_writeq(value, csr);
+}
+
+static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value)
+{
+	void __iomem *csr = sport->memctrl + reg;
+
+	__raw_writeq(value, csr);
+}
+
+/*
+ * In bug 1956, we get glitches that can mess up uart registers.  This
+ * "read-mode-reg after any register access" is an accepted workaround.
+ */
+static void __war_sbd1956(struct sbd_port *sport)
+{
+	__read_sbdchn(sport, R_DUART_MODE_REG_1);
+	__read_sbdchn(sport, R_DUART_MODE_REG_2);
+}
+
+static unsigned char read_sbdchn(struct sbd_port *sport, int reg)
+{
+	unsigned char retval;
+
+	retval = __read_sbdchn(sport, reg);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+	return retval;
+}
+
+static unsigned char read_sbdshr(struct sbd_port *sport, int reg)
+{
+	unsigned char retval;
+
+	retval = __read_sbdshr(sport, reg);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+	return retval;
+}
+
+static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value)
+{
+	__write_sbdchn(sport, reg, value);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+}
+
+static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value)
+{
+	__write_sbdshr(sport, reg, value);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+}
+
+
+static int sbd_receive_ready(struct sbd_port *sport)
+{
+	return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY;
+}
+
+static int sbd_receive_drain(struct sbd_port *sport)
+{
+	int loops = 10000;
+
+	while (sbd_receive_ready(sport) && --loops)
+		read_sbdchn(sport, R_DUART_RX_HOLD);
+	return loops;
+}
+
+static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport)
+{
+	return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY;
+}
+
+static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
+{
+	int loops = 10000;
+
+	while (!sbd_transmit_ready(sport) && --loops)
+		udelay(2);
+	return loops;
+}
+
+static int sbd_transmit_empty(struct sbd_port *sport)
+{
+	return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT;
+}
+
+static int sbd_line_drain(struct sbd_port *sport)
+{
+	int loops = 10000;
+
+	while (!sbd_transmit_empty(sport) && --loops)
+		udelay(2);
+	return loops;
+}
+
+
+static unsigned int sbd_tx_empty(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int sbd_get_mctrl(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mctrl, status;
+
+	status = read_sbdshr(sport, R_DUART_IN_PORT);
+	status >>= (uport->line) % 2;
+	mctrl = (!(status & M_DUART_IN_PIN0_VAL) ? TIOCM_CTS : 0) |
+		(!(status & M_DUART_IN_PIN4_VAL) ? TIOCM_CAR : 0) |
+		(!(status & M_DUART_RIN0_PIN) ? TIOCM_RNG : 0) |
+		(!(status & M_DUART_IN_PIN2_VAL) ? TIOCM_DSR : 0);
+	return mctrl;
+}
+
+static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int clr = 0, set = 0, mode2;
+
+	if (mctrl & TIOCM_DTR)
+		set |= M_DUART_SET_OPR2;
+	else
+		clr |= M_DUART_CLR_OPR2;
+	if (mctrl & TIOCM_RTS)
+		set |= M_DUART_SET_OPR0;
+	else
+		clr |= M_DUART_CLR_OPR0;
+	clr <<= (uport->line) % 2;
+	set <<= (uport->line) % 2;
+
+	mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2);
+	mode2 &= ~M_DUART_CHAN_MODE;
+	if (mctrl & TIOCM_LOOP)
+		mode2 |= V_DUART_CHAN_MODE_LCL_LOOP;
+	else
+		mode2 |= V_DUART_CHAN_MODE_NORMAL;
+
+	write_sbdshr(sport, R_DUART_CLEAR_OPR, clr);
+	write_sbdshr(sport, R_DUART_SET_OPR, set);
+	write_sbdchn(sport, R_DUART_MODE_REG_2, mode2);
+}
+
+static void sbd_stop_tx(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
+	sport->tx_stopped = 1;
+};
+
+static void sbd_start_tx(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mask;
+
+	/* Enable tx interrupts.  */
+	mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
+	mask |= M_DUART_IMR_TX;
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
+
+	/* Go!, go!, go!...  */
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
+	sport->tx_stopped = 0;
+};
+
+static void sbd_stop_rx(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
+};
+
+static void sbd_enable_ms(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdchn(sport, R_DUART_AUXCTL_X,
+		     M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA);
+}
+
+static void sbd_break_ctl(struct uart_port *uport, int break_state)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	if (break_state == -1)
+		write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_START_BREAK);
+	else
+		write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_STOP_BREAK);
+}
+
+
+static void sbd_receive_chars(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+	struct uart_icount *icount;
+	unsigned int status;
+	int count;
+	u8 ch, flag;
+
+	for (count = 16; count; count--) {
+		status = read_sbdchn(sport, R_DUART_STATUS);
+		if (!(status & M_DUART_RX_RDY))
+			break;
+
+		ch = read_sbdchn(sport, R_DUART_RX_HOLD);
+
+		flag = TTY_NORMAL;
+
+		icount = &uport->icount;
+		icount->rx++;
+
+		if (unlikely(status &
+			     (M_DUART_RCVD_BRK | M_DUART_FRM_ERR |
+			      M_DUART_PARITY_ERR | M_DUART_OVRUN_ERR))) {
+			if (status & M_DUART_RCVD_BRK) {
+				icount->brk++;
+				if (uart_handle_break(uport))
+					continue;
+			} else if (status & M_DUART_FRM_ERR)
+				icount->frame++;
+			else if (status & M_DUART_PARITY_ERR)
+				icount->parity++;
+			if (status & M_DUART_OVRUN_ERR)
+				icount->overrun++;
+
+			status &= uport->read_status_mask;
+			if (status & M_DUART_RCVD_BRK)
+				flag = TTY_BREAK;
+			else if (status & M_DUART_FRM_ERR)
+				flag = TTY_FRAME;
+			else if (status & M_DUART_PARITY_ERR)
+				flag = TTY_PARITY;
+		}
+
+		if (uart_handle_sysrq_char(uport, ch))
+			continue;
+
+		uart_insert_char(uport, status, M_DUART_OVRUN_ERR, ch, flag);
+	}
+
+	tty_flip_buffer_push(&uport->state->port);
+}
+
+static void sbd_transmit_chars(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	unsigned int mask;
+	int stop_tx;
+
+	/* XON/XOFF chars.  */
+	if (sport->port.x_char) {
+		write_sbdchn(sport, R_DUART_TX_HOLD, sport->port.x_char);
+		sport->port.icount.tx++;
+		sport->port.x_char = 0;
+		return;
+	}
+
+	/* If nothing to do or stopped or hardware stopped.  */
+	stop_tx = (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port));
+
+	/* Send char.  */
+	if (!stop_tx) {
+		write_sbdchn(sport, R_DUART_TX_HOLD, xmit->buf[xmit->tail]);
+		uart_xmit_advance(&sport->port, 1);
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&sport->port);
+	}
+
+	/* Are we are done?  */
+	if (stop_tx || uart_circ_empty(xmit)) {
+		/* Disable tx interrupts.  */
+		mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
+		mask &= ~M_DUART_IMR_TX;
+		write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
+	}
+}
+
+static void sbd_status_handle(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+	unsigned int delta;
+
+	delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
+	delta >>= (uport->line) % 2;
+
+	if (delta & (M_DUART_IN_PIN0_VAL << S_DUART_IN_PIN_CHNG))
+		uart_handle_cts_change(uport, !(delta & M_DUART_IN_PIN0_VAL));
+
+	if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG))
+		uport->icount.dsr++;
+
+	if (delta & ((M_DUART_IN_PIN2_VAL | M_DUART_IN_PIN0_VAL) <<
+		     S_DUART_IN_PIN_CHNG))
+		wake_up_interruptible(&uport->state->port.delta_msr_wait);
+}
+
+static irqreturn_t sbd_interrupt(int irq, void *dev_id)
+{
+	struct sbd_port *sport = dev_id;
+	struct uart_port *uport = &sport->port;
+	irqreturn_t status = IRQ_NONE;
+	unsigned int intstat;
+	int count;
+
+	for (count = 16; count; count--) {
+		intstat = read_sbdshr(sport,
+				      R_DUART_ISRREG((uport->line) % 2));
+		intstat &= read_sbdshr(sport,
+				       R_DUART_IMRREG((uport->line) % 2));
+		intstat &= M_DUART_ISR_ALL;
+		if (!intstat)
+			break;
+
+		if (intstat & M_DUART_ISR_RX)
+			sbd_receive_chars(sport);
+		if (intstat & M_DUART_ISR_IN)
+			sbd_status_handle(sport);
+		if (intstat & M_DUART_ISR_TX)
+			sbd_transmit_chars(sport);
+
+		status = IRQ_HANDLED;
+	}
+
+	return status;
+}
+
+
+static int sbd_startup(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mode1;
+	int ret;
+
+	ret = request_irq(sport->port.irq, sbd_interrupt,
+			  IRQF_SHARED, "sb1250-duart", sport);
+	if (ret)
+		return ret;
+
+	/* Clear the receive FIFO.  */
+	sbd_receive_drain(sport);
+
+	/* Clear the interrupt registers.  */
+	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT);
+	read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
+
+	/* Set rx/tx interrupt to FIFO available.  */
+	mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1);
+	mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT);
+	write_sbdchn(sport, R_DUART_MODE_REG_1, mode1);
+
+	/* Disable tx, enable rx.  */
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN);
+	sport->tx_stopped = 1;
+
+	/* Enable interrupts.  */
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
+		     M_DUART_IMR_IN | M_DUART_IMR_RX);
+
+	return 0;
+}
+
+static void sbd_shutdown(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
+	sport->tx_stopped = 1;
+	free_irq(sport->port.irq, sport);
+}
+
+
+static void sbd_init_port(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+
+	if (sport->initialised)
+		return;
+
+	/* There is no DUART reset feature, so just set some sane defaults.  */
+	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX);
+	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX);
+	write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8);
+	write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
+	write_sbdchn(sport, R_DUART_FULL_CTL,
+		     V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15));
+	write_sbdchn(sport, R_DUART_OPCR_X, 0);
+	write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
+
+	sport->initialised = 1;
+}
+
+static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
+			    const struct ktermios *old_termios)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mode1 = 0, mode2 = 0, aux = 0;
+	unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0;
+	unsigned int oldmode1, oldmode2, oldaux;
+	unsigned int baud, brg;
+	unsigned int command;
+
+	mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD |
+		       M_DUART_BITS_PER_CHAR);
+	mode2mask |= ~M_DUART_STOP_BIT_LEN_2;
+	auxmask |= ~M_DUART_CTS_CHNG_ENA;
+
+	/* Byte size.  */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+	case CS6:
+		/* Unsupported, leave unchanged.  */
+		mode1mask |= M_DUART_PARITY_MODE;
+		break;
+	case CS7:
+		mode1 |= V_DUART_BITS_PER_CHAR_7;
+		break;
+	case CS8:
+	default:
+		mode1 |= V_DUART_BITS_PER_CHAR_8;
+		break;
+	}
+
+	/* Parity and stop bits.  */
+	if (termios->c_cflag & CSTOPB)
+		mode2 |= M_DUART_STOP_BIT_LEN_2;
+	else
+		mode2 |= M_DUART_STOP_BIT_LEN_1;
+	if (termios->c_cflag & PARENB)
+		mode1 |= V_DUART_PARITY_MODE_ADD;
+	else
+		mode1 |= V_DUART_PARITY_MODE_NONE;
+	if (termios->c_cflag & PARODD)
+		mode1 |= M_DUART_PARITY_TYPE_ODD;
+	else
+		mode1 |= M_DUART_PARITY_TYPE_EVEN;
+
+	baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000);
+	brg = V_DUART_BAUD_RATE(baud);
+	/* The actual lower bound is 1221bps, so compensate.  */
+	if (brg > M_DUART_CLK_COUNTER)
+		brg = M_DUART_CLK_COUNTER;
+
+	uart_update_timeout(uport, termios->c_cflag, baud);
+
+	uport->read_status_mask = M_DUART_OVRUN_ERR;
+	if (termios->c_iflag & INPCK)
+		uport->read_status_mask |= M_DUART_FRM_ERR |
+					   M_DUART_PARITY_ERR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		uport->read_status_mask |= M_DUART_RCVD_BRK;
+
+	uport->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		uport->ignore_status_mask |= M_DUART_FRM_ERR |
+					     M_DUART_PARITY_ERR;
+	if (termios->c_iflag & IGNBRK) {
+		uport->ignore_status_mask |= M_DUART_RCVD_BRK;
+		if (termios->c_iflag & IGNPAR)
+			uport->ignore_status_mask |= M_DUART_OVRUN_ERR;
+	}
+
+	if (termios->c_cflag & CREAD)
+		command = M_DUART_RX_EN;
+	else
+		command = M_DUART_RX_DIS;
+
+	if (termios->c_cflag & CRTSCTS)
+		aux |= M_DUART_CTS_CHNG_ENA;
+	else
+		aux &= ~M_DUART_CTS_CHNG_ENA;
+
+	spin_lock(&uport->lock);
+
+	if (sport->tx_stopped)
+		command |= M_DUART_TX_DIS;
+	else
+		command |= M_DUART_TX_EN;
+
+	oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask;
+	oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
+	oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;
+
+	if (!sport->tx_stopped)
+		sbd_line_drain(sport);
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
+
+	write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1);
+	write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);
+	write_sbdchn(sport, R_DUART_CLK_SEL, brg);
+	write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);
+
+	write_sbdchn(sport, R_DUART_CMD, command);
+
+	spin_unlock(&uport->lock);
+}
+
+
+static const char *sbd_type(struct uart_port *uport)
+{
+	return "SB1250 DUART";
+}
+
+static void sbd_release_port(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	struct sbd_duart *duart = sport->duart;
+
+	iounmap(sport->memctrl);
+	sport->memctrl = NULL;
+	iounmap(uport->membase);
+	uport->membase = NULL;
+
+	if(refcount_dec_and_test(&duart->map_guard))
+		release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING);
+	release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
+}
+
+static int sbd_map_port(struct uart_port *uport)
+{
+	const char *err = KERN_ERR "sbd: Cannot map MMIO\n";
+	struct sbd_port *sport = to_sport(uport);
+	struct sbd_duart *duart = sport->duart;
+
+	if (!uport->membase)
+		uport->membase = ioremap(uport->mapbase,
+						 DUART_CHANREG_SPACING);
+	if (!uport->membase) {
+		printk(err);
+		return -ENOMEM;
+	}
+
+	if (!sport->memctrl)
+		sport->memctrl = ioremap(duart->mapctrl,
+						 DUART_CHANREG_SPACING);
+	if (!sport->memctrl) {
+		printk(err);
+		iounmap(uport->membase);
+		uport->membase = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int sbd_request_port(struct uart_port *uport)
+{
+	const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n";
+	struct sbd_duart *duart = to_sport(uport)->duart;
+	int ret = 0;
+
+	if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
+				"sb1250-duart")) {
+		printk(err);
+		return -EBUSY;
+	}
+	refcount_inc(&duart->map_guard);
+	if (refcount_read(&duart->map_guard) == 1) {
+		if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING,
+					"sb1250-duart")) {
+			refcount_dec(&duart->map_guard);
+			printk(err);
+			ret = -EBUSY;
+		}
+	}
+	if (!ret) {
+		ret = sbd_map_port(uport);
+		if (ret) {
+			if (refcount_dec_and_test(&duart->map_guard))
+				release_mem_region(duart->mapctrl,
+						   DUART_CHANREG_SPACING);
+		}
+	}
+	if (ret) {
+		release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
+		return ret;
+	}
+	return 0;
+}
+
+static void sbd_config_port(struct uart_port *uport, int flags)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	if (flags & UART_CONFIG_TYPE) {
+		if (sbd_request_port(uport))
+			return;
+
+		uport->type = PORT_SB1250_DUART;
+
+		sbd_init_port(sport);
+	}
+}
+
+static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART)
+		ret = -EINVAL;
+	if (ser->irq != uport->irq)
+		ret = -EINVAL;
+	if (ser->baud_base != uport->uartclk / 16)
+		ret = -EINVAL;
+	return ret;
+}
+
+
+static const struct uart_ops sbd_ops = {
+	.tx_empty	= sbd_tx_empty,
+	.set_mctrl	= sbd_set_mctrl,
+	.get_mctrl	= sbd_get_mctrl,
+	.stop_tx	= sbd_stop_tx,
+	.start_tx	= sbd_start_tx,
+	.stop_rx	= sbd_stop_rx,
+	.enable_ms	= sbd_enable_ms,
+	.break_ctl	= sbd_break_ctl,
+	.startup	= sbd_startup,
+	.shutdown	= sbd_shutdown,
+	.set_termios	= sbd_set_termios,
+	.type		= sbd_type,
+	.release_port	= sbd_release_port,
+	.request_port	= sbd_request_port,
+	.config_port	= sbd_config_port,
+	.verify_port	= sbd_verify_port,
+};
+
+/* Initialize SB1250 DUART port structures.  */
+static void __init sbd_probe_duarts(void)
+{
+	static int probed;
+	int chip, side;
+	int max_lines, line;
+
+	if (probed)
+		return;
+
+	/* Set the number of available units based on the SOC type.  */
+	switch (soc_type) {
+	case K_SYS_SOC_TYPE_BCM1x55:
+	case K_SYS_SOC_TYPE_BCM1x80:
+		max_lines = 4;
+		break;
+	default:
+		/* Assume at least two serial ports at the normal address.  */
+		max_lines = 2;
+		break;
+	}
+
+	probed = 1;
+
+	for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
+	     chip++) {
+		sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);
+
+		for (side = 0; side < DUART_MAX_SIDE && line < max_lines;
+		     side++, line++) {
+			struct sbd_port *sport = &sbd_duarts[chip].sport[side];
+			struct uart_port *uport = &sport->port;
+
+			sport->duart	= &sbd_duarts[chip];
+
+			uport->irq	= SBD_INT(line);
+			uport->uartclk	= 100000000 / 20 * 16;
+			uport->fifosize	= 16;
+			uport->iotype	= UPIO_MEM;
+			uport->flags	= UPF_BOOT_AUTOCONF;
+			uport->ops	= &sbd_ops;
+			uport->line	= line;
+			uport->mapbase	= SBD_CHANREGS(line);
+			uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SB1250_DUART_CONSOLE);
+		}
+	}
+}
+
+
+#ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
+/*
+ * Serial console stuff.  Very basic, polling driver for doing serial
+ * console output.  The console_lock is held by the caller, so we
+ * shouldn't be interrupted for more console activity.
+ */
+static void sbd_console_putchar(struct uart_port *uport, unsigned char ch)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	sbd_transmit_drain(sport);
+	write_sbdchn(sport, R_DUART_TX_HOLD, ch);
+}
+
+static void sbd_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	int chip = co->index / DUART_MAX_SIDE;
+	int side = co->index % DUART_MAX_SIDE;
+	struct sbd_port *sport = &sbd_duarts[chip].sport[side];
+	struct uart_port *uport = &sport->port;
+	unsigned long flags;
+	unsigned int mask;
+
+	/* Disable transmit interrupts and enable the transmitter. */
+	spin_lock_irqsave(&uport->lock, flags);
+	mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
+		     mask & ~M_DUART_IMR_TX);
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	uart_console_write(&sport->port, s, count, sbd_console_putchar);
+
+	/* Restore transmit interrupts and the transmitter enable. */
+	spin_lock_irqsave(&uport->lock, flags);
+	sbd_line_drain(sport);
+	if (sport->tx_stopped)
+		write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+static int __init sbd_console_setup(struct console *co, char *options)
+{
+	int chip = co->index / DUART_MAX_SIDE;
+	int side = co->index % DUART_MAX_SIDE;
+	struct sbd_port *sport = &sbd_duarts[chip].sport[side];
+	struct uart_port *uport = &sport->port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	if (!sport->duart)
+		return -ENXIO;
+
+	ret = sbd_map_port(uport);
+	if (ret)
+		return ret;
+
+	sbd_init_port(sport);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	return uart_set_options(uport, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sbd_reg;
+static struct console sbd_console = {
+	.name	= "duart",
+	.write	= sbd_console_write,
+	.device	= uart_console_device,
+	.setup	= sbd_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &sbd_reg
+};
+
+static int __init sbd_serial_console_init(void)
+{
+	sbd_probe_duarts();
+	register_console(&sbd_console);
+
+	return 0;
+}
+
+console_initcall(sbd_serial_console_init);
+
+#define SERIAL_SB1250_DUART_CONSOLE	&sbd_console
+#else
+#define SERIAL_SB1250_DUART_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */
+
+
+static struct uart_driver sbd_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "sb1250_duart",
+	.dev_name	= "duart",
+	.major		= TTY_MAJOR,
+	.minor		= SB1250_DUART_MINOR_BASE,
+	.nr		= DUART_MAX_CHIP * DUART_MAX_SIDE,
+	.cons		= SERIAL_SB1250_DUART_CONSOLE,
+};
+
+/* Set up the driver and register it.  */
+static int __init sbd_init(void)
+{
+	int i, ret;
+
+	sbd_probe_duarts();
+
+	ret = uart_register_driver(&sbd_reg);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) {
+		struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
+		struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
+		struct uart_port *uport = &sport->port;
+
+		if (sport->duart)
+			uart_add_one_port(&sbd_reg, uport);
+	}
+
+	return 0;
+}
+
+/* Unload the driver.  Unregister stuff, get ready to go away.  */
+static void __exit sbd_exit(void)
+{
+	int i;
+
+	for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) {
+		struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
+		struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
+		struct uart_port *uport = &sport->port;
+
+		if (sport->duart)
+			uart_remove_one_port(&sbd_reg, uport);
+	}
+
+	uart_unregister_driver(&sbd_reg);
+}
+
+module_init(sbd_init);
+module_exit(sbd_exit);
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
new file mode 100644
index 000000000..f75b8bceb
--- /dev/null
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -0,0 +1,1898 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint
+ * Author: Jon Ringle <jringle@gridpoint.com>
+ *
+ *  Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/spi/spi.h>
+#include <linux/uaccess.h>
+#include <linux/units.h>
+#include <uapi/linux/sched/types.h>
+
+#define SC16IS7XX_NAME			"sc16is7xx"
+#define SC16IS7XX_MAX_DEVS		8
+
+/* SC16IS7XX register definitions */
+#define SC16IS7XX_RHR_REG		(0x00) /* RX FIFO */
+#define SC16IS7XX_THR_REG		(0x00) /* TX FIFO */
+#define SC16IS7XX_IER_REG		(0x01) /* Interrupt enable */
+#define SC16IS7XX_IIR_REG		(0x02) /* Interrupt Identification */
+#define SC16IS7XX_FCR_REG		(0x02) /* FIFO control */
+#define SC16IS7XX_LCR_REG		(0x03) /* Line Control */
+#define SC16IS7XX_MCR_REG		(0x04) /* Modem Control */
+#define SC16IS7XX_LSR_REG		(0x05) /* Line Status */
+#define SC16IS7XX_MSR_REG		(0x06) /* Modem Status */
+#define SC16IS7XX_SPR_REG		(0x07) /* Scratch Pad */
+#define SC16IS7XX_TXLVL_REG		(0x08) /* TX FIFO level */
+#define SC16IS7XX_RXLVL_REG		(0x09) /* RX FIFO level */
+#define SC16IS7XX_IODIR_REG		(0x0a) /* I/O Direction
+						* - only on 75x/76x
+						*/
+#define SC16IS7XX_IOSTATE_REG		(0x0b) /* I/O State
+						* - only on 75x/76x
+						*/
+#define SC16IS7XX_IOINTENA_REG		(0x0c) /* I/O Interrupt Enable
+						* - only on 75x/76x
+						*/
+#define SC16IS7XX_IOCONTROL_REG		(0x0e) /* I/O Control
+						* - only on 75x/76x
+						*/
+#define SC16IS7XX_EFCR_REG		(0x0f) /* Extra Features Control */
+
+/* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
+#define SC16IS7XX_TCR_REG		(0x06) /* Transmit control */
+#define SC16IS7XX_TLR_REG		(0x07) /* Trigger level */
+
+/* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
+#define SC16IS7XX_DLL_REG		(0x00) /* Divisor Latch Low */
+#define SC16IS7XX_DLH_REG		(0x01) /* Divisor Latch High */
+
+/* Enhanced Register set: Only if (LCR == 0xBF) */
+#define SC16IS7XX_EFR_REG		(0x02) /* Enhanced Features */
+#define SC16IS7XX_XON1_REG		(0x04) /* Xon1 word */
+#define SC16IS7XX_XON2_REG		(0x05) /* Xon2 word */
+#define SC16IS7XX_XOFF1_REG		(0x06) /* Xoff1 word */
+#define SC16IS7XX_XOFF2_REG		(0x07) /* Xoff2 word */
+
+/* IER register bits */
+#define SC16IS7XX_IER_RDI_BIT		(1 << 0) /* Enable RX data interrupt */
+#define SC16IS7XX_IER_THRI_BIT		(1 << 1) /* Enable TX holding register
+						  * interrupt */
+#define SC16IS7XX_IER_RLSI_BIT		(1 << 2) /* Enable RX line status
+						  * interrupt */
+#define SC16IS7XX_IER_MSI_BIT		(1 << 3) /* Enable Modem status
+						  * interrupt */
+
+/* IER register bits - write only if (EFR[4] == 1) */
+#define SC16IS7XX_IER_SLEEP_BIT		(1 << 4) /* Enable Sleep mode */
+#define SC16IS7XX_IER_XOFFI_BIT		(1 << 5) /* Enable Xoff interrupt */
+#define SC16IS7XX_IER_RTSI_BIT		(1 << 6) /* Enable nRTS interrupt */
+#define SC16IS7XX_IER_CTSI_BIT		(1 << 7) /* Enable nCTS interrupt */
+
+/* FCR register bits */
+#define SC16IS7XX_FCR_FIFO_BIT		(1 << 0) /* Enable FIFO */
+#define SC16IS7XX_FCR_RXRESET_BIT	(1 << 1) /* Reset RX FIFO */
+#define SC16IS7XX_FCR_TXRESET_BIT	(1 << 2) /* Reset TX FIFO */
+#define SC16IS7XX_FCR_RXLVLL_BIT	(1 << 6) /* RX Trigger level LSB */
+#define SC16IS7XX_FCR_RXLVLH_BIT	(1 << 7) /* RX Trigger level MSB */
+
+/* FCR register bits - write only if (EFR[4] == 1) */
+#define SC16IS7XX_FCR_TXLVLL_BIT	(1 << 4) /* TX Trigger level LSB */
+#define SC16IS7XX_FCR_TXLVLH_BIT	(1 << 5) /* TX Trigger level MSB */
+
+/* IIR register bits */
+#define SC16IS7XX_IIR_NO_INT_BIT	(1 << 0) /* No interrupts pending */
+#define SC16IS7XX_IIR_ID_MASK		0x3e     /* Mask for the interrupt ID */
+#define SC16IS7XX_IIR_THRI_SRC		0x02     /* TX holding register empty */
+#define SC16IS7XX_IIR_RDI_SRC		0x04     /* RX data interrupt */
+#define SC16IS7XX_IIR_RLSE_SRC		0x06     /* RX line status error */
+#define SC16IS7XX_IIR_RTOI_SRC		0x0c     /* RX time-out interrupt */
+#define SC16IS7XX_IIR_MSI_SRC		0x00     /* Modem status interrupt
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_IIR_INPIN_SRC		0x30     /* Input pin change of state
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_IIR_XOFFI_SRC		0x10     /* Received Xoff */
+#define SC16IS7XX_IIR_CTSRTS_SRC	0x20     /* nCTS,nRTS change of state
+						  * from active (LOW)
+						  * to inactive (HIGH)
+						  */
+/* LCR register bits */
+#define SC16IS7XX_LCR_LENGTH0_BIT	(1 << 0) /* Word length bit 0 */
+#define SC16IS7XX_LCR_LENGTH1_BIT	(1 << 1) /* Word length bit 1
+						  *
+						  * Word length bits table:
+						  * 00 -> 5 bit words
+						  * 01 -> 6 bit words
+						  * 10 -> 7 bit words
+						  * 11 -> 8 bit words
+						  */
+#define SC16IS7XX_LCR_STOPLEN_BIT	(1 << 2) /* STOP length bit
+						  *
+						  * STOP length bit table:
+						  * 0 -> 1 stop bit
+						  * 1 -> 1-1.5 stop bits if
+						  *      word length is 5,
+						  *      2 stop bits otherwise
+						  */
+#define SC16IS7XX_LCR_PARITY_BIT	(1 << 3) /* Parity bit enable */
+#define SC16IS7XX_LCR_EVENPARITY_BIT	(1 << 4) /* Even parity bit enable */
+#define SC16IS7XX_LCR_FORCEPARITY_BIT	(1 << 5) /* 9-bit multidrop parity */
+#define SC16IS7XX_LCR_TXBREAK_BIT	(1 << 6) /* TX break enable */
+#define SC16IS7XX_LCR_DLAB_BIT		(1 << 7) /* Divisor Latch enable */
+#define SC16IS7XX_LCR_WORD_LEN_5	(0x00)
+#define SC16IS7XX_LCR_WORD_LEN_6	(0x01)
+#define SC16IS7XX_LCR_WORD_LEN_7	(0x02)
+#define SC16IS7XX_LCR_WORD_LEN_8	(0x03)
+#define SC16IS7XX_LCR_CONF_MODE_A	SC16IS7XX_LCR_DLAB_BIT /* Special
+								* reg set */
+#define SC16IS7XX_LCR_CONF_MODE_B	0xBF                   /* Enhanced
+								* reg set */
+
+/* MCR register bits */
+#define SC16IS7XX_MCR_DTR_BIT		(1 << 0) /* DTR complement
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MCR_RTS_BIT		(1 << 1) /* RTS complement */
+#define SC16IS7XX_MCR_TCRTLR_BIT	(1 << 2) /* TCR/TLR register enable */
+#define SC16IS7XX_MCR_LOOP_BIT		(1 << 4) /* Enable loopback test mode */
+#define SC16IS7XX_MCR_XONANY_BIT	(1 << 5) /* Enable Xon Any
+						  * - write enabled
+						  * if (EFR[4] == 1)
+						  */
+#define SC16IS7XX_MCR_IRDA_BIT		(1 << 6) /* Enable IrDA mode
+						  * - write enabled
+						  * if (EFR[4] == 1)
+						  */
+#define SC16IS7XX_MCR_CLKSEL_BIT	(1 << 7) /* Divide clock by 4
+						  * - write enabled
+						  * if (EFR[4] == 1)
+						  */
+
+/* LSR register bits */
+#define SC16IS7XX_LSR_DR_BIT		(1 << 0) /* Receiver data ready */
+#define SC16IS7XX_LSR_OE_BIT		(1 << 1) /* Overrun Error */
+#define SC16IS7XX_LSR_PE_BIT		(1 << 2) /* Parity Error */
+#define SC16IS7XX_LSR_FE_BIT		(1 << 3) /* Frame Error */
+#define SC16IS7XX_LSR_BI_BIT		(1 << 4) /* Break Interrupt */
+#define SC16IS7XX_LSR_BRK_ERROR_MASK	0x1E     /* BI, FE, PE, OE bits */
+#define SC16IS7XX_LSR_THRE_BIT		(1 << 5) /* TX holding register empty */
+#define SC16IS7XX_LSR_TEMT_BIT		(1 << 6) /* Transmitter empty */
+#define SC16IS7XX_LSR_FIFOE_BIT		(1 << 7) /* Fifo Error */
+
+/* MSR register bits */
+#define SC16IS7XX_MSR_DCTS_BIT		(1 << 0) /* Delta CTS Clear To Send */
+#define SC16IS7XX_MSR_DDSR_BIT		(1 << 1) /* Delta DSR Data Set Ready
+						  * or (IO4)
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MSR_DRI_BIT		(1 << 2) /* Delta RI Ring Indicator
+						  * or (IO7)
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MSR_DCD_BIT		(1 << 3) /* Delta CD Carrier Detect
+						  * or (IO6)
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MSR_CTS_BIT		(1 << 4) /* CTS */
+#define SC16IS7XX_MSR_DSR_BIT		(1 << 5) /* DSR (IO4)
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MSR_RI_BIT		(1 << 6) /* RI (IO7)
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MSR_CD_BIT		(1 << 7) /* CD (IO6)
+						  * - only on 75x/76x
+						  */
+#define SC16IS7XX_MSR_DELTA_MASK	0x0F     /* Any of the delta bits! */
+
+/*
+ * TCR register bits
+ * TCR trigger levels are available from 0 to 60 characters with a granularity
+ * of four.
+ * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
+ * no built-in hardware check to make sure this condition is met. Also, the TCR
+ * must be programmed with this condition before auto RTS or software flow
+ * control is enabled to avoid spurious operation of the device.
+ */
+#define SC16IS7XX_TCR_RX_HALT(words)	((((words) / 4) & 0x0f) << 0)
+#define SC16IS7XX_TCR_RX_RESUME(words)	((((words) / 4) & 0x0f) << 4)
+
+/*
+ * TLR register bits
+ * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
+ * FIFO Control Register (FCR) are used for the transmit and receive FIFO
+ * trigger levels. Trigger levels from 4 characters to 60 characters are
+ * available with a granularity of four.
+ *
+ * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
+ * trigger level setting defined in FCR. If TLR has non-zero trigger level value
+ * the trigger level defined in FCR is discarded. This applies to both transmit
+ * FIFO and receive FIFO trigger level setting.
+ *
+ * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
+ * default state, that is, '00'.
+ */
+#define SC16IS7XX_TLR_TX_TRIGGER(words)	((((words) / 4) & 0x0f) << 0)
+#define SC16IS7XX_TLR_RX_TRIGGER(words)	((((words) / 4) & 0x0f) << 4)
+
+/* IOControl register bits (Only 750/760) */
+#define SC16IS7XX_IOCONTROL_LATCH_BIT	(1 << 0) /* Enable input latching */
+#define SC16IS7XX_IOCONTROL_MODEM_A_BIT	(1 << 1) /* Enable GPIO[7:4] as modem A pins */
+#define SC16IS7XX_IOCONTROL_MODEM_B_BIT	(1 << 2) /* Enable GPIO[3:0] as modem B pins */
+#define SC16IS7XX_IOCONTROL_SRESET_BIT	(1 << 3) /* Software Reset */
+
+/* EFCR register bits */
+#define SC16IS7XX_EFCR_9BIT_MODE_BIT	(1 << 0) /* Enable 9-bit or Multidrop
+						  * mode (RS485) */
+#define SC16IS7XX_EFCR_RXDISABLE_BIT	(1 << 1) /* Disable receiver */
+#define SC16IS7XX_EFCR_TXDISABLE_BIT	(1 << 2) /* Disable transmitter */
+#define SC16IS7XX_EFCR_AUTO_RS485_BIT	(1 << 4) /* Auto RS485 RTS direction */
+#define SC16IS7XX_EFCR_RTS_INVERT_BIT	(1 << 5) /* RTS output inversion */
+#define SC16IS7XX_EFCR_IRDA_MODE_BIT	(1 << 7) /* IrDA mode
+						  * 0 = rate upto 115.2 kbit/s
+						  *   - Only 750/760
+						  * 1 = rate upto 1.152 Mbit/s
+						  *   - Only 760
+						  */
+
+/* EFR register bits */
+#define SC16IS7XX_EFR_AUTORTS_BIT	(1 << 6) /* Auto RTS flow ctrl enable */
+#define SC16IS7XX_EFR_AUTOCTS_BIT	(1 << 7) /* Auto CTS flow ctrl enable */
+#define SC16IS7XX_EFR_XOFF2_DETECT_BIT	(1 << 5) /* Enable Xoff2 detection */
+#define SC16IS7XX_EFR_ENABLE_BIT	(1 << 4) /* Enable enhanced functions
+						  * and writing to IER[7:4],
+						  * FCR[5:4], MCR[7:5]
+						  */
+#define SC16IS7XX_EFR_SWFLOW3_BIT	(1 << 3) /* SWFLOW bit 3 */
+#define SC16IS7XX_EFR_SWFLOW2_BIT	(1 << 2) /* SWFLOW bit 2
+						  *
+						  * SWFLOW bits 3 & 2 table:
+						  * 00 -> no transmitter flow
+						  *       control
+						  * 01 -> transmitter generates
+						  *       XON2 and XOFF2
+						  * 10 -> transmitter generates
+						  *       XON1 and XOFF1
+						  * 11 -> transmitter generates
+						  *       XON1, XON2, XOFF1 and
+						  *       XOFF2
+						  */
+#define SC16IS7XX_EFR_SWFLOW1_BIT	(1 << 1) /* SWFLOW bit 2 */
+#define SC16IS7XX_EFR_SWFLOW0_BIT	(1 << 0) /* SWFLOW bit 3
+						  *
+						  * SWFLOW bits 3 & 2 table:
+						  * 00 -> no received flow
+						  *       control
+						  * 01 -> receiver compares
+						  *       XON2 and XOFF2
+						  * 10 -> receiver compares
+						  *       XON1 and XOFF1
+						  * 11 -> receiver compares
+						  *       XON1, XON2, XOFF1 and
+						  *       XOFF2
+						  */
+#define SC16IS7XX_EFR_FLOWCTRL_BITS	(SC16IS7XX_EFR_AUTORTS_BIT | \
+					SC16IS7XX_EFR_AUTOCTS_BIT | \
+					SC16IS7XX_EFR_XOFF2_DETECT_BIT | \
+					SC16IS7XX_EFR_SWFLOW3_BIT | \
+					SC16IS7XX_EFR_SWFLOW2_BIT | \
+					SC16IS7XX_EFR_SWFLOW1_BIT | \
+					SC16IS7XX_EFR_SWFLOW0_BIT)
+
+
+/* Misc definitions */
+#define SC16IS7XX_SPI_READ_BIT		BIT(7)
+#define SC16IS7XX_FIFO_SIZE		(64)
+#define SC16IS7XX_GPIOS_PER_BANK	4
+
+struct sc16is7xx_devtype {
+	char	name[10];
+	int	nr_gpio;
+	int	nr_uart;
+};
+
+#define SC16IS7XX_RECONF_MD		(1 << 0)
+#define SC16IS7XX_RECONF_IER		(1 << 1)
+#define SC16IS7XX_RECONF_RS485		(1 << 2)
+
+struct sc16is7xx_one_config {
+	unsigned int			flags;
+	u8				ier_mask;
+	u8				ier_val;
+};
+
+struct sc16is7xx_one {
+	struct uart_port		port;
+	struct regmap			*regmap;
+	struct mutex			efr_lock; /* EFR registers access */
+	struct kthread_work		tx_work;
+	struct kthread_work		reg_work;
+	struct kthread_delayed_work	ms_work;
+	struct sc16is7xx_one_config	config;
+	bool				irda_mode;
+	unsigned int			old_mctrl;
+};
+
+struct sc16is7xx_port {
+	const struct sc16is7xx_devtype	*devtype;
+	struct clk			*clk;
+#ifdef CONFIG_GPIOLIB
+	struct gpio_chip		gpio;
+	unsigned long			gpio_valid_mask;
+#endif
+	u8				mctrl_mask;
+	unsigned char			buf[SC16IS7XX_FIFO_SIZE];
+	struct kthread_worker		kworker;
+	struct task_struct		*kworker_task;
+	struct sc16is7xx_one		p[];
+};
+
+static unsigned long sc16is7xx_lines;
+
+static struct uart_driver sc16is7xx_uart = {
+	.owner		= THIS_MODULE,
+	.dev_name	= "ttySC",
+	.nr		= SC16IS7XX_MAX_DEVS,
+};
+
+static void sc16is7xx_ier_set(struct uart_port *port, u8 bit);
+static void sc16is7xx_stop_tx(struct uart_port *port);
+
+#define to_sc16is7xx_port(p,e)	((container_of((p), struct sc16is7xx_port, e)))
+#define to_sc16is7xx_one(p,e)	((container_of((p), struct sc16is7xx_one, e)))
+
+static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	unsigned int val = 0;
+
+	regmap_read(one->regmap, reg, &val);
+
+	return val;
+}
+
+static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	regmap_write(one->regmap, reg, val);
+}
+
+static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, s->buf, rxlen);
+}
+
+static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	/*
+	 * Don't send zero-length data, at least on SPI it confuses the chip
+	 * delivering wrong TXLVL data.
+	 */
+	if (unlikely(!to_send))
+		return;
+
+	regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, s->buf, to_send);
+}
+
+static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
+				  u8 mask, u8 val)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	regmap_update_bits(one->regmap, reg, mask, val);
+}
+
+static void sc16is7xx_power(struct uart_port *port, int on)
+{
+	sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
+			      SC16IS7XX_IER_SLEEP_BIT,
+			      on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
+}
+
+static const struct sc16is7xx_devtype sc16is74x_devtype = {
+	.name		= "SC16IS74X",
+	.nr_gpio	= 0,
+	.nr_uart	= 1,
+};
+
+static const struct sc16is7xx_devtype sc16is750_devtype = {
+	.name		= "SC16IS750",
+	.nr_gpio	= 8,
+	.nr_uart	= 1,
+};
+
+static const struct sc16is7xx_devtype sc16is752_devtype = {
+	.name		= "SC16IS752",
+	.nr_gpio	= 8,
+	.nr_uart	= 2,
+};
+
+static const struct sc16is7xx_devtype sc16is760_devtype = {
+	.name		= "SC16IS760",
+	.nr_gpio	= 8,
+	.nr_uart	= 1,
+};
+
+static const struct sc16is7xx_devtype sc16is762_devtype = {
+	.name		= "SC16IS762",
+	.nr_gpio	= 8,
+	.nr_uart	= 2,
+};
+
+static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SC16IS7XX_RHR_REG:
+	case SC16IS7XX_IIR_REG:
+	case SC16IS7XX_LSR_REG:
+	case SC16IS7XX_MSR_REG:
+	case SC16IS7XX_TXLVL_REG:
+	case SC16IS7XX_RXLVL_REG:
+	case SC16IS7XX_IOSTATE_REG:
+	case SC16IS7XX_IOCONTROL_REG:
+		return true;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SC16IS7XX_RHR_REG:
+		return true;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
+{
+	return reg == SC16IS7XX_RHR_REG;
+}
+
+static int sc16is7xx_set_baud(struct uart_port *port, int baud)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	u8 lcr;
+	u8 prescaler = 0;
+	unsigned long clk = port->uartclk, div = clk / 16 / baud;
+
+	if (div > 0xffff) {
+		prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
+		div /= 4;
+	}
+
+	/* In an amazing feat of design, the Enhanced Features Register shares
+	 * the address of the Interrupt Identification Register, and is
+	 * switched in by writing a magic value (0xbf) to the Line Control
+	 * Register. Any interrupt firing during this time will see the EFR
+	 * where it expects the IIR to be, leading to "Unexpected interrupt"
+	 * messages.
+	 *
+	 * Prevent this possibility by claiming a mutex while accessing the
+	 * EFR, and claiming the same mutex from within the interrupt handler.
+	 * This is similar to disabling the interrupt, but that doesn't work
+	 * because the bulk of the interrupt processing is run as a workqueue
+	 * job in thread context.
+	 */
+	mutex_lock(&one->efr_lock);
+
+	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
+
+	/* Open the LCR divisors for configuration */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
+			     SC16IS7XX_LCR_CONF_MODE_B);
+
+	/* Enable enhanced features */
+	regcache_cache_bypass(one->regmap, true);
+	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
+			      SC16IS7XX_EFR_ENABLE_BIT,
+			      SC16IS7XX_EFR_ENABLE_BIT);
+
+	regcache_cache_bypass(one->regmap, false);
+
+	/* Put LCR back to the normal mode */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
+
+	mutex_unlock(&one->efr_lock);
+
+	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
+			      SC16IS7XX_MCR_CLKSEL_BIT,
+			      prescaler);
+
+	/* Open the LCR divisors for configuration */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
+			     SC16IS7XX_LCR_CONF_MODE_A);
+
+	/* Write the new divisor */
+	regcache_cache_bypass(one->regmap, true);
+	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
+	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
+	regcache_cache_bypass(one->regmap, false);
+
+	/* Put LCR back to the normal mode */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
+
+	return DIV_ROUND_CLOSEST(clk / 16, div);
+}
+
+static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
+				unsigned int iir)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	unsigned int lsr = 0, bytes_read, i;
+	bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
+	u8 ch, flag;
+
+	if (unlikely(rxlen >= sizeof(s->buf))) {
+		dev_warn_ratelimited(port->dev,
+				     "ttySC%i: Possible RX FIFO overrun: %d\n",
+				     port->line, rxlen);
+		port->icount.buf_overrun++;
+		/* Ensure sanity of RX level */
+		rxlen = sizeof(s->buf);
+	}
+
+	while (rxlen) {
+		/* Only read lsr if there are possible errors in FIFO */
+		if (read_lsr) {
+			lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
+			if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
+				read_lsr = false; /* No errors left in FIFO */
+		} else
+			lsr = 0;
+
+		if (read_lsr) {
+			s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
+			bytes_read = 1;
+		} else {
+			sc16is7xx_fifo_read(port, rxlen);
+			bytes_read = rxlen;
+		}
+
+		lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
+
+		port->icount.rx++;
+		flag = TTY_NORMAL;
+
+		if (unlikely(lsr)) {
+			if (lsr & SC16IS7XX_LSR_BI_BIT) {
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			} else if (lsr & SC16IS7XX_LSR_PE_BIT)
+				port->icount.parity++;
+			else if (lsr & SC16IS7XX_LSR_FE_BIT)
+				port->icount.frame++;
+			else if (lsr & SC16IS7XX_LSR_OE_BIT)
+				port->icount.overrun++;
+
+			lsr &= port->read_status_mask;
+			if (lsr & SC16IS7XX_LSR_BI_BIT)
+				flag = TTY_BREAK;
+			else if (lsr & SC16IS7XX_LSR_PE_BIT)
+				flag = TTY_PARITY;
+			else if (lsr & SC16IS7XX_LSR_FE_BIT)
+				flag = TTY_FRAME;
+			else if (lsr & SC16IS7XX_LSR_OE_BIT)
+				flag = TTY_OVERRUN;
+		}
+
+		for (i = 0; i < bytes_read; ++i) {
+			ch = s->buf[i];
+			if (uart_handle_sysrq_char(port, ch))
+				continue;
+
+			if (lsr & port->ignore_status_mask)
+				continue;
+
+			uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
+					 flag);
+		}
+		rxlen -= bytes_read;
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void sc16is7xx_handle_tx(struct uart_port *port)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int txlen, to_send, i;
+	unsigned long flags;
+
+	if (unlikely(port->x_char)) {
+		sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		uart_port_lock_irqsave(port, &flags);
+		sc16is7xx_stop_tx(port);
+		uart_port_unlock_irqrestore(port, flags);
+		return;
+	}
+
+	/* Get length of data pending in circular buffer */
+	to_send = uart_circ_chars_pending(xmit);
+	if (likely(to_send)) {
+		/* Limit to size of TX FIFO */
+		txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
+		if (txlen > SC16IS7XX_FIFO_SIZE) {
+			dev_err_ratelimited(port->dev,
+				"chip reports %d free bytes in TX fifo, but it only has %d",
+				txlen, SC16IS7XX_FIFO_SIZE);
+			txlen = 0;
+		}
+		to_send = (to_send > txlen) ? txlen : to_send;
+
+		/* Convert to linear buffer */
+		for (i = 0; i < to_send; ++i) {
+			s->buf[i] = xmit->buf[xmit->tail];
+			uart_xmit_advance(port, 1);
+		}
+
+		sc16is7xx_fifo_write(port, to_send);
+	}
+
+	uart_port_lock_irqsave(port, &flags);
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		sc16is7xx_stop_tx(port);
+	else
+		sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
+	uart_port_unlock_irqrestore(port, flags);
+}
+
+static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
+{
+	u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
+	unsigned int mctrl = 0;
+
+	mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
+	mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
+	mctrl |= (msr & SC16IS7XX_MSR_CD_BIT)  ? TIOCM_CAR : 0;
+	mctrl |= (msr & SC16IS7XX_MSR_RI_BIT)  ? TIOCM_RNG : 0;
+	return mctrl;
+}
+
+static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
+{
+	struct uart_port *port = &one->port;
+	unsigned long flags;
+	unsigned int status, changed;
+
+	lockdep_assert_held_once(&one->efr_lock);
+
+	status = sc16is7xx_get_hwmctrl(port);
+	changed = status ^ one->old_mctrl;
+
+	if (changed == 0)
+		return;
+
+	one->old_mctrl = status;
+
+	uart_port_lock_irqsave(port, &flags);
+	if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
+		port->icount.rng++;
+	if (changed & TIOCM_DSR)
+		port->icount.dsr++;
+	if (changed & TIOCM_CAR)
+		uart_handle_dcd_change(port, status & TIOCM_CAR);
+	if (changed & TIOCM_CTS)
+		uart_handle_cts_change(port, status & TIOCM_CTS);
+
+	wake_up_interruptible(&port->state->port.delta_msr_wait);
+	uart_port_unlock_irqrestore(port, flags);
+}
+
+static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
+{
+	bool rc = true;
+	unsigned int iir, rxlen;
+	struct uart_port *port = &s->p[portno].port;
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	mutex_lock(&one->efr_lock);
+
+	iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
+	if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
+		rc = false;
+		goto out_port_irq;
+	}
+
+	iir &= SC16IS7XX_IIR_ID_MASK;
+
+	switch (iir) {
+	case SC16IS7XX_IIR_RDI_SRC:
+	case SC16IS7XX_IIR_RLSE_SRC:
+	case SC16IS7XX_IIR_RTOI_SRC:
+	case SC16IS7XX_IIR_XOFFI_SRC:
+		rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
+
+		/*
+		 * There is a silicon bug that makes the chip report a
+		 * time-out interrupt but no data in the FIFO. This is
+		 * described in errata section 18.1.4.
+		 *
+		 * When this happens, read one byte from the FIFO to
+		 * clear the interrupt.
+		 */
+		if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
+			rxlen = 1;
+
+		if (rxlen)
+			sc16is7xx_handle_rx(port, rxlen, iir);
+		break;
+		/* CTSRTS interrupt comes only when CTS goes inactive */
+	case SC16IS7XX_IIR_CTSRTS_SRC:
+	case SC16IS7XX_IIR_MSI_SRC:
+		sc16is7xx_update_mlines(one);
+		break;
+	case SC16IS7XX_IIR_THRI_SRC:
+		sc16is7xx_handle_tx(port);
+		break;
+	default:
+		dev_err_ratelimited(port->dev,
+				    "ttySC%i: Unexpected interrupt: %x",
+				    port->line, iir);
+		break;
+	}
+
+out_port_irq:
+	mutex_unlock(&one->efr_lock);
+
+	return rc;
+}
+
+static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
+{
+	bool keep_polling;
+
+	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
+
+	do {
+		int i;
+
+		keep_polling = false;
+
+		for (i = 0; i < s->devtype->nr_uart; ++i)
+			keep_polling |= sc16is7xx_port_irq(s, i);
+	} while (keep_polling);
+
+	return IRQ_HANDLED;
+}
+
+static void sc16is7xx_tx_proc(struct kthread_work *ws)
+{
+	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	if ((port->rs485.flags & SER_RS485_ENABLED) &&
+	    (port->rs485.delay_rts_before_send > 0))
+		msleep(port->rs485.delay_rts_before_send);
+
+	mutex_lock(&one->efr_lock);
+	sc16is7xx_handle_tx(port);
+	mutex_unlock(&one->efr_lock);
+}
+
+static void sc16is7xx_reconf_rs485(struct uart_port *port)
+{
+	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
+			 SC16IS7XX_EFCR_RTS_INVERT_BIT;
+	u32 efcr = 0;
+	struct serial_rs485 *rs485 = &port->rs485;
+	unsigned long irqflags;
+
+	uart_port_lock_irqsave(port, &irqflags);
+	if (rs485->flags & SER_RS485_ENABLED) {
+		efcr |=	SC16IS7XX_EFCR_AUTO_RS485_BIT;
+
+		if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
+			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
+	}
+	uart_port_unlock_irqrestore(port, irqflags);
+
+	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
+}
+
+static void sc16is7xx_reg_proc(struct kthread_work *ws)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
+	struct sc16is7xx_one_config config;
+	unsigned long irqflags;
+
+	uart_port_lock_irqsave(&one->port, &irqflags);
+	config = one->config;
+	memset(&one->config, 0, sizeof(one->config));
+	uart_port_unlock_irqrestore(&one->port, irqflags);
+
+	if (config.flags & SC16IS7XX_RECONF_MD) {
+		u8 mcr = 0;
+
+		/* Device ignores RTS setting when hardware flow is enabled */
+		if (one->port.mctrl & TIOCM_RTS)
+			mcr |= SC16IS7XX_MCR_RTS_BIT;
+
+		if (one->port.mctrl & TIOCM_DTR)
+			mcr |= SC16IS7XX_MCR_DTR_BIT;
+
+		if (one->port.mctrl & TIOCM_LOOP)
+			mcr |= SC16IS7XX_MCR_LOOP_BIT;
+		sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
+				      SC16IS7XX_MCR_RTS_BIT |
+				      SC16IS7XX_MCR_DTR_BIT |
+				      SC16IS7XX_MCR_LOOP_BIT,
+				      mcr);
+	}
+
+	if (config.flags & SC16IS7XX_RECONF_IER)
+		sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
+				      config.ier_mask, config.ier_val);
+
+	if (config.flags & SC16IS7XX_RECONF_RS485)
+		sc16is7xx_reconf_rs485(&one->port);
+}
+
+static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	lockdep_assert_held_once(&port->lock);
+
+	one->config.flags |= SC16IS7XX_RECONF_IER;
+	one->config.ier_mask |= bit;
+	one->config.ier_val &= ~bit;
+	kthread_queue_work(&s->kworker, &one->reg_work);
+}
+
+static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	lockdep_assert_held_once(&port->lock);
+
+	one->config.flags |= SC16IS7XX_RECONF_IER;
+	one->config.ier_mask |= bit;
+	one->config.ier_val |= bit;
+	kthread_queue_work(&s->kworker, &one->reg_work);
+}
+
+static void sc16is7xx_stop_tx(struct uart_port *port)
+{
+	sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
+}
+
+static void sc16is7xx_stop_rx(struct uart_port *port)
+{
+	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
+}
+
+static void sc16is7xx_ms_proc(struct kthread_work *ws)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
+	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
+
+	if (one->port.state) {
+		mutex_lock(&one->efr_lock);
+		sc16is7xx_update_mlines(one);
+		mutex_unlock(&one->efr_lock);
+
+		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
+	}
+}
+
+static void sc16is7xx_enable_ms(struct uart_port *port)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+
+	lockdep_assert_held_once(&port->lock);
+
+	kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
+}
+
+static void sc16is7xx_start_tx(struct uart_port *port)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	kthread_queue_work(&s->kworker, &one->tx_work);
+}
+
+static void sc16is7xx_throttle(struct uart_port *port)
+{
+	unsigned long flags;
+
+	/*
+	 * Hardware flow control is enabled and thus the device ignores RTS
+	 * value set in MCR register. Stop reading data from RX FIFO so the
+	 * AutoRTS feature will de-activate RTS output.
+	 */
+	uart_port_lock_irqsave(port, &flags);
+	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
+	uart_port_unlock_irqrestore(port, flags);
+}
+
+static void sc16is7xx_unthrottle(struct uart_port *port)
+{
+	unsigned long flags;
+
+	uart_port_lock_irqsave(port, &flags);
+	sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
+	uart_port_unlock_irqrestore(port, flags);
+}
+
+static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
+{
+	unsigned int lsr;
+
+	lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
+
+	return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	/* Called with port lock taken so we can only return cached value */
+	return one->old_mctrl;
+}
+
+static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	one->config.flags |= SC16IS7XX_RECONF_MD;
+	kthread_queue_work(&s->kworker, &one->reg_work);
+}
+
+static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
+{
+	sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
+			      SC16IS7XX_LCR_TXBREAK_BIT,
+			      break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
+}
+
+static void sc16is7xx_set_termios(struct uart_port *port,
+				  struct ktermios *termios,
+				  const struct ktermios *old)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	unsigned int lcr, flow = 0;
+	int baud;
+	unsigned long flags;
+
+	kthread_cancel_delayed_work_sync(&one->ms_work);
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+
+	/* Word size */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr = SC16IS7XX_LCR_WORD_LEN_5;
+		break;
+	case CS6:
+		lcr = SC16IS7XX_LCR_WORD_LEN_6;
+		break;
+	case CS7:
+		lcr = SC16IS7XX_LCR_WORD_LEN_7;
+		break;
+	case CS8:
+		lcr = SC16IS7XX_LCR_WORD_LEN_8;
+		break;
+	default:
+		lcr = SC16IS7XX_LCR_WORD_LEN_8;
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+		break;
+	}
+
+	/* Parity */
+	if (termios->c_cflag & PARENB) {
+		lcr |= SC16IS7XX_LCR_PARITY_BIT;
+		if (!(termios->c_cflag & PARODD))
+			lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
+	}
+
+	/* Stop bits */
+	if (termios->c_cflag & CSTOPB)
+		lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
+
+	/* Set read status mask */
+	port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
+					  SC16IS7XX_LSR_FE_BIT;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNBRK)
+		port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
+
+	/* As above, claim the mutex while accessing the EFR. */
+	mutex_lock(&one->efr_lock);
+
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
+			     SC16IS7XX_LCR_CONF_MODE_B);
+
+	/* Configure flow control */
+	regcache_cache_bypass(one->regmap, true);
+	sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
+	sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
+
+	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
+	if (termios->c_cflag & CRTSCTS) {
+		flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
+			SC16IS7XX_EFR_AUTORTS_BIT;
+		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+	}
+	if (termios->c_iflag & IXON)
+		flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
+	if (termios->c_iflag & IXOFF)
+		flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
+
+	sc16is7xx_port_update(port,
+			      SC16IS7XX_EFR_REG,
+			      SC16IS7XX_EFR_FLOWCTRL_BITS,
+			      flow);
+	regcache_cache_bypass(one->regmap, false);
+
+	/* Update LCR register */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
+
+	mutex_unlock(&one->efr_lock);
+
+	/* Get baud rate generator configuration */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / 16 / 4 / 0xffff,
+				  port->uartclk / 16);
+
+	/* Setup baudrate generator */
+	baud = sc16is7xx_set_baud(port, baud);
+
+	uart_port_lock_irqsave(port, &flags);
+
+	/* Update timeout according to new baud rate */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		sc16is7xx_enable_ms(port);
+
+	uart_port_unlock_irqrestore(port, flags);
+}
+
+static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
+				  struct serial_rs485 *rs485)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		/*
+		 * RTS signal is handled by HW, it's timing can't be influenced.
+		 * However, it's sometimes useful to delay TX even without RTS
+		 * control therefore we try to handle .delay_rts_before_send.
+		 */
+		if (rs485->delay_rts_after_send)
+			return -EINVAL;
+	}
+
+	one->config.flags |= SC16IS7XX_RECONF_RS485;
+	kthread_queue_work(&s->kworker, &one->reg_work);
+
+	return 0;
+}
+
+static int sc16is7xx_startup(struct uart_port *port)
+{
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	unsigned int val;
+	unsigned long flags;
+
+	sc16is7xx_power(port, 1);
+
+	/* Reset FIFOs*/
+	val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
+	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
+	udelay(5);
+	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
+			     SC16IS7XX_FCR_FIFO_BIT);
+
+	/* Enable EFR */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
+			     SC16IS7XX_LCR_CONF_MODE_B);
+
+	regcache_cache_bypass(one->regmap, true);
+
+	/* Enable write access to enhanced features and internal clock div */
+	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
+			      SC16IS7XX_EFR_ENABLE_BIT,
+			      SC16IS7XX_EFR_ENABLE_BIT);
+
+	/* Enable TCR/TLR */
+	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
+			      SC16IS7XX_MCR_TCRTLR_BIT,
+			      SC16IS7XX_MCR_TCRTLR_BIT);
+
+	/* Configure flow control levels */
+	/* Flow control halt level 48, resume level 24 */
+	sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
+			     SC16IS7XX_TCR_RX_RESUME(24) |
+			     SC16IS7XX_TCR_RX_HALT(48));
+
+	regcache_cache_bypass(one->regmap, false);
+
+	/* Now, initialize the UART */
+	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
+
+	/* Enable IrDA mode if requested in DT */
+	/* This bit must be written with LCR[7] = 0 */
+	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
+			      SC16IS7XX_MCR_IRDA_BIT,
+			      one->irda_mode ?
+				SC16IS7XX_MCR_IRDA_BIT : 0);
+
+	/* Enable the Rx and Tx FIFO */
+	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
+			      SC16IS7XX_EFCR_RXDISABLE_BIT |
+			      SC16IS7XX_EFCR_TXDISABLE_BIT,
+			      0);
+
+	/* Enable RX, CTS change and modem lines interrupts */
+	val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
+	      SC16IS7XX_IER_MSI_BIT;
+	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
+
+	/* Enable modem status polling */
+	uart_port_lock_irqsave(port, &flags);
+	sc16is7xx_enable_ms(port);
+	uart_port_unlock_irqrestore(port, flags);
+
+	return 0;
+}
+
+static void sc16is7xx_shutdown(struct uart_port *port)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	kthread_cancel_delayed_work_sync(&one->ms_work);
+
+	/* Disable all interrupts */
+	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
+	/* Disable TX/RX */
+	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
+			      SC16IS7XX_EFCR_RXDISABLE_BIT |
+			      SC16IS7XX_EFCR_TXDISABLE_BIT,
+			      SC16IS7XX_EFCR_RXDISABLE_BIT |
+			      SC16IS7XX_EFCR_TXDISABLE_BIT);
+
+	sc16is7xx_power(port, 0);
+
+	kthread_flush_worker(&s->kworker);
+}
+
+static const char *sc16is7xx_type(struct uart_port *port)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+
+	return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
+}
+
+static int sc16is7xx_request_port(struct uart_port *port)
+{
+	/* Do nothing */
+	return 0;
+}
+
+static void sc16is7xx_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_SC16IS7XX;
+}
+
+static int sc16is7xx_verify_port(struct uart_port *port,
+				 struct serial_struct *s)
+{
+	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
+		return -EINVAL;
+	if (s->irq != port->irq)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
+			 unsigned int oldstate)
+{
+	sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
+}
+
+static void sc16is7xx_null_void(struct uart_port *port)
+{
+	/* Do nothing */
+}
+
+static const struct uart_ops sc16is7xx_ops = {
+	.tx_empty	= sc16is7xx_tx_empty,
+	.set_mctrl	= sc16is7xx_set_mctrl,
+	.get_mctrl	= sc16is7xx_get_mctrl,
+	.stop_tx	= sc16is7xx_stop_tx,
+	.start_tx	= sc16is7xx_start_tx,
+	.throttle	= sc16is7xx_throttle,
+	.unthrottle	= sc16is7xx_unthrottle,
+	.stop_rx	= sc16is7xx_stop_rx,
+	.enable_ms	= sc16is7xx_enable_ms,
+	.break_ctl	= sc16is7xx_break_ctl,
+	.startup	= sc16is7xx_startup,
+	.shutdown	= sc16is7xx_shutdown,
+	.set_termios	= sc16is7xx_set_termios,
+	.type		= sc16is7xx_type,
+	.request_port	= sc16is7xx_request_port,
+	.release_port	= sc16is7xx_null_void,
+	.config_port	= sc16is7xx_config_port,
+	.verify_port	= sc16is7xx_verify_port,
+	.pm		= sc16is7xx_pm,
+};
+
+#ifdef CONFIG_GPIOLIB
+static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	unsigned int val;
+	struct sc16is7xx_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[0].port;
+
+	val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
+
+	return !!(val & BIT(offset));
+}
+
+static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+	struct sc16is7xx_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[0].port;
+
+	sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
+			      val ? BIT(offset) : 0);
+}
+
+static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
+					  unsigned offset)
+{
+	struct sc16is7xx_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[0].port;
+
+	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
+
+	return 0;
+}
+
+static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
+					   unsigned offset, int val)
+{
+	struct sc16is7xx_port *s = gpiochip_get_data(chip);
+	struct uart_port *port = &s->p[0].port;
+	u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
+
+	if (val)
+		state |= BIT(offset);
+	else
+		state &= ~BIT(offset);
+
+	/*
+	 * If we write IOSTATE first, and then IODIR, the output value is not
+	 * transferred to the corresponding I/O pin.
+	 * The datasheet states that each register bit will be transferred to
+	 * the corresponding I/O pin programmed as output when writing to
+	 * IOSTATE. Therefore, configure direction first with IODIR, and then
+	 * set value after with IOSTATE.
+	 */
+	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
+			      BIT(offset));
+	sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
+
+	return 0;
+}
+
+static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip,
+					  unsigned long *valid_mask,
+					  unsigned int ngpios)
+{
+	struct sc16is7xx_port *s = gpiochip_get_data(chip);
+
+	*valid_mask = s->gpio_valid_mask;
+
+	return 0;
+}
+
+static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
+{
+	struct device *dev = s->p[0].port.dev;
+
+	if (!s->devtype->nr_gpio)
+		return 0;
+
+	switch (s->mctrl_mask) {
+	case 0:
+		s->gpio_valid_mask = GENMASK(7, 0);
+		break;
+	case SC16IS7XX_IOCONTROL_MODEM_A_BIT:
+		s->gpio_valid_mask = GENMASK(3, 0);
+		break;
+	case SC16IS7XX_IOCONTROL_MODEM_B_BIT:
+		s->gpio_valid_mask = GENMASK(7, 4);
+		break;
+	default:
+		break;
+	}
+
+	if (s->gpio_valid_mask == 0)
+		return 0;
+
+	s->gpio.owner		 = THIS_MODULE;
+	s->gpio.parent		 = dev;
+	s->gpio.label		 = dev_name(dev);
+	s->gpio.init_valid_mask	 = sc16is7xx_gpio_init_valid_mask;
+	s->gpio.direction_input	 = sc16is7xx_gpio_direction_input;
+	s->gpio.get		 = sc16is7xx_gpio_get;
+	s->gpio.direction_output = sc16is7xx_gpio_direction_output;
+	s->gpio.set		 = sc16is7xx_gpio_set;
+	s->gpio.base		 = -1;
+	s->gpio.ngpio		 = s->devtype->nr_gpio;
+	s->gpio.can_sleep	 = 1;
+
+	return gpiochip_add_data(&s->gpio, s);
+}
+#endif
+
+/*
+ * Configure ports designated to operate as modem control lines.
+ */
+static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
+				       struct regmap *regmap)
+{
+	int i;
+	int ret;
+	int count;
+	u32 mctrl_port[2];
+	struct device *dev = s->p[0].port.dev;
+
+	count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
+	if (count < 0 || count > ARRAY_SIZE(mctrl_port))
+		return 0;
+
+	ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports",
+					     mctrl_port, count);
+	if (ret)
+		return ret;
+
+	s->mctrl_mask = 0;
+
+	for (i = 0; i < count; i++) {
+		/* Use GPIO lines as modem control lines */
+		if (mctrl_port[i] == 0)
+			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
+		else if (mctrl_port[i] == 1)
+			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
+	}
+
+	if (s->mctrl_mask)
+		regmap_update_bits(
+			regmap,
+			SC16IS7XX_IOCONTROL_REG,
+			SC16IS7XX_IOCONTROL_MODEM_A_BIT |
+			SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
+
+	return 0;
+}
+
+static const struct serial_rs485 sc16is7xx_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
+};
+
+static int sc16is7xx_probe(struct device *dev,
+			   const struct sc16is7xx_devtype *devtype,
+			   struct regmap *regmaps[], int irq)
+{
+	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
+	unsigned int val;
+	u32 uartclk = 0;
+	int i, ret;
+	struct sc16is7xx_port *s;
+
+	for (i = 0; i < devtype->nr_uart; i++)
+		if (IS_ERR(regmaps[i]))
+			return PTR_ERR(regmaps[i]);
+
+	/*
+	 * This device does not have an identification register that would
+	 * tell us if we are really connected to the correct device.
+	 * The best we can do is to check if communication is at all possible.
+	 *
+	 * Note: regmap[0] is used in the probe function to access registers
+	 * common to all channels/ports, as it is guaranteed to be present on
+	 * all variants.
+	 */
+	ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
+	if (ret < 0)
+		return -EPROBE_DEFER;
+
+	/* Alloc port structure */
+	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
+	if (!s) {
+		dev_err(dev, "Error allocating port structure\n");
+		return -ENOMEM;
+	}
+
+	/* Always ask for fixed clock rate from a property. */
+	device_property_read_u32(dev, "clock-frequency", &uartclk);
+
+	s->clk = devm_clk_get_optional(dev, NULL);
+	if (IS_ERR(s->clk))
+		return PTR_ERR(s->clk);
+
+	ret = clk_prepare_enable(s->clk);
+	if (ret)
+		return ret;
+
+	freq = clk_get_rate(s->clk);
+	if (freq == 0) {
+		if (uartclk)
+			freq = uartclk;
+		if (pfreq)
+			freq = *pfreq;
+		if (freq)
+			dev_dbg(dev, "Clock frequency: %luHz\n", freq);
+		else
+			return -EINVAL;
+	}
+
+	s->devtype = devtype;
+	dev_set_drvdata(dev, s);
+
+	kthread_init_worker(&s->kworker);
+	s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
+				      "sc16is7xx");
+	if (IS_ERR(s->kworker_task)) {
+		ret = PTR_ERR(s->kworker_task);
+		goto out_clk;
+	}
+	sched_set_fifo(s->kworker_task);
+
+	/* reset device, purging any pending irq / data */
+	regmap_write(regmaps[0], SC16IS7XX_IOCONTROL_REG,
+		     SC16IS7XX_IOCONTROL_SRESET_BIT);
+
+	for (i = 0; i < devtype->nr_uart; ++i) {
+		s->p[i].port.line = find_first_zero_bit(&sc16is7xx_lines,
+							SC16IS7XX_MAX_DEVS);
+		if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
+			ret = -ERANGE;
+			goto out_ports;
+		}
+
+		/* Initialize port data */
+		s->p[i].port.dev	= dev;
+		s->p[i].port.irq	= irq;
+		s->p[i].port.type	= PORT_SC16IS7XX;
+		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
+		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
+		s->p[i].port.iobase	= i;
+		/*
+		 * Use all ones as membase to make sure uart_configure_port() in
+		 * serial_core.c does not abort for SPI/I2C devices where the
+		 * membase address is not applicable.
+		 */
+		s->p[i].port.membase	= (void __iomem *)~0;
+		s->p[i].port.iotype	= UPIO_PORT;
+		s->p[i].port.uartclk	= freq;
+		s->p[i].port.rs485_config = sc16is7xx_config_rs485;
+		s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
+		s->p[i].port.ops	= &sc16is7xx_ops;
+		s->p[i].old_mctrl	= 0;
+		s->p[i].regmap		= regmaps[i];
+
+		mutex_init(&s->p[i].efr_lock);
+
+		ret = uart_get_rs485_mode(&s->p[i].port);
+		if (ret)
+			goto out_ports;
+
+		/* Disable all interrupts */
+		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
+		/* Disable TX/RX */
+		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
+				     SC16IS7XX_EFCR_RXDISABLE_BIT |
+				     SC16IS7XX_EFCR_TXDISABLE_BIT);
+
+		/* Initialize kthread work structs */
+		kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
+		kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
+		kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
+
+		/* Register port */
+		ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
+		if (ret)
+			goto out_ports;
+
+		set_bit(s->p[i].port.line, &sc16is7xx_lines);
+
+		/* Enable EFR */
+		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
+				     SC16IS7XX_LCR_CONF_MODE_B);
+
+		regcache_cache_bypass(regmaps[i], true);
+
+		/* Enable write access to enhanced features */
+		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
+				     SC16IS7XX_EFR_ENABLE_BIT);
+
+		regcache_cache_bypass(regmaps[i], false);
+
+		/* Restore access to general registers */
+		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
+
+		/* Go to suspend mode */
+		sc16is7xx_power(&s->p[i].port, 0);
+	}
+
+	if (dev->of_node) {
+		struct property *prop;
+		const __be32 *p;
+		u32 u;
+
+		of_property_for_each_u32(dev->of_node, "irda-mode-ports",
+					 prop, p, u)
+			if (u < devtype->nr_uart)
+				s->p[u].irda_mode = true;
+	}
+
+	ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
+	if (ret)
+		goto out_ports;
+
+#ifdef CONFIG_GPIOLIB
+	ret = sc16is7xx_setup_gpio_chip(s);
+	if (ret)
+		goto out_ports;
+#endif
+
+	/*
+	 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
+	 * If that succeeds, we can allow sharing the interrupt as well.
+	 * In case the interrupt controller doesn't support that, we fall
+	 * back to a non-shared falling-edge trigger.
+	 */
+	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
+					IRQF_TRIGGER_LOW | IRQF_SHARED |
+					IRQF_ONESHOT,
+					dev_name(dev), s);
+	if (!ret)
+		return 0;
+
+	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					dev_name(dev), s);
+	if (!ret)
+		return 0;
+
+#ifdef CONFIG_GPIOLIB
+	if (s->gpio_valid_mask)
+		gpiochip_remove(&s->gpio);
+#endif
+
+out_ports:
+	for (i = 0; i < devtype->nr_uart; i++)
+		if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
+			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
+
+	kthread_stop(s->kworker_task);
+
+out_clk:
+	clk_disable_unprepare(s->clk);
+
+	return ret;
+}
+
+static void sc16is7xx_remove(struct device *dev)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(dev);
+	int i;
+
+#ifdef CONFIG_GPIOLIB
+	if (s->gpio_valid_mask)
+		gpiochip_remove(&s->gpio);
+#endif
+
+	for (i = 0; i < s->devtype->nr_uart; i++) {
+		kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
+		if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
+			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
+		sc16is7xx_power(&s->p[i].port, 0);
+	}
+
+	kthread_flush_worker(&s->kworker);
+	kthread_stop(s->kworker_task);
+
+	clk_disable_unprepare(s->clk);
+}
+
+static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
+	{ .compatible = "nxp,sc16is740",	.data = &sc16is74x_devtype, },
+	{ .compatible = "nxp,sc16is741",	.data = &sc16is74x_devtype, },
+	{ .compatible = "nxp,sc16is750",	.data = &sc16is750_devtype, },
+	{ .compatible = "nxp,sc16is752",	.data = &sc16is752_devtype, },
+	{ .compatible = "nxp,sc16is760",	.data = &sc16is760_devtype, },
+	{ .compatible = "nxp,sc16is762",	.data = &sc16is762_devtype, },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
+
+static struct regmap_config regcfg = {
+	.reg_bits = 5,
+	.pad_bits = 3,
+	.val_bits = 8,
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_reg = sc16is7xx_regmap_volatile,
+	.precious_reg = sc16is7xx_regmap_precious,
+	.writeable_noinc_reg = sc16is7xx_regmap_noinc,
+	.readable_noinc_reg = sc16is7xx_regmap_noinc,
+	.max_raw_read = SC16IS7XX_FIFO_SIZE,
+	.max_raw_write = SC16IS7XX_FIFO_SIZE,
+	.max_register = SC16IS7XX_EFCR_REG,
+};
+
+static const char *sc16is7xx_regmap_name(u8 port_id)
+{
+	switch (port_id) {
+	case 0:	return "port0";
+	case 1:	return "port1";
+	default:
+		WARN_ON(true);
+		return NULL;
+	}
+}
+
+static unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
+{
+	/* CH1,CH0 are at bits 2:1. */
+	return port_id << 1;
+}
+
+#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
+static int sc16is7xx_spi_probe(struct spi_device *spi)
+{
+	const struct sc16is7xx_devtype *devtype;
+	struct regmap *regmaps[2];
+	unsigned int i;
+	int ret;
+
+	/* Setup SPI bus */
+	spi->bits_per_word	= 8;
+	/* For all variants, only mode 0 is supported */
+	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
+		return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
+
+	spi->mode		= spi->mode ? : SPI_MODE_0;
+	spi->max_speed_hz	= spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
+	ret = spi_setup(spi);
+	if (ret)
+		return ret;
+
+	if (spi->dev.of_node) {
+		devtype = device_get_match_data(&spi->dev);
+		if (!devtype)
+			return -ENODEV;
+	} else {
+		const struct spi_device_id *id_entry = spi_get_device_id(spi);
+
+		devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
+	}
+
+	for (i = 0; i < devtype->nr_uart; i++) {
+		regcfg.name = sc16is7xx_regmap_name(i);
+		/*
+		 * If read_flag_mask is 0, the regmap code sets it to a default
+		 * of 0x80. Since we specify our own mask, we must add the READ
+		 * bit ourselves:
+		 */
+		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
+			SC16IS7XX_SPI_READ_BIT;
+		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
+	}
+
+	return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);
+}
+
+static void sc16is7xx_spi_remove(struct spi_device *spi)
+{
+	sc16is7xx_remove(&spi->dev);
+}
+
+static const struct spi_device_id sc16is7xx_spi_id_table[] = {
+	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
+	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
+	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
+	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
+
+static struct spi_driver sc16is7xx_spi_uart_driver = {
+	.driver = {
+		.name		= SC16IS7XX_NAME,
+		.of_match_table	= sc16is7xx_dt_ids,
+	},
+	.probe		= sc16is7xx_spi_probe,
+	.remove		= sc16is7xx_spi_remove,
+	.id_table	= sc16is7xx_spi_id_table,
+};
+
+MODULE_ALIAS("spi:sc16is7xx");
+#endif
+
+#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
+static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
+	const struct sc16is7xx_devtype *devtype;
+	struct regmap *regmaps[2];
+	unsigned int i;
+
+	if (i2c->dev.of_node) {
+		devtype = device_get_match_data(&i2c->dev);
+		if (!devtype)
+			return -ENODEV;
+	} else {
+		devtype = (struct sc16is7xx_devtype *)id->driver_data;
+	}
+
+	for (i = 0; i < devtype->nr_uart; i++) {
+		regcfg.name = sc16is7xx_regmap_name(i);
+		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regmaps[i] = devm_regmap_init_i2c(i2c, &regcfg);
+	}
+
+	return sc16is7xx_probe(&i2c->dev, devtype, regmaps, i2c->irq);
+}
+
+static void sc16is7xx_i2c_remove(struct i2c_client *client)
+{
+	sc16is7xx_remove(&client->dev);
+}
+
+static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
+	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
+	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
+	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
+	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
+
+static struct i2c_driver sc16is7xx_i2c_uart_driver = {
+	.driver = {
+		.name		= SC16IS7XX_NAME,
+		.of_match_table	= sc16is7xx_dt_ids,
+	},
+	.probe		= sc16is7xx_i2c_probe,
+	.remove		= sc16is7xx_i2c_remove,
+	.id_table	= sc16is7xx_i2c_id_table,
+};
+
+#endif
+
+static int __init sc16is7xx_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&sc16is7xx_uart);
+	if (ret) {
+		pr_err("Registering UART driver failed\n");
+		return ret;
+	}
+
+#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
+	ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
+	if (ret < 0) {
+		pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
+		goto err_i2c;
+	}
+#endif
+
+#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
+	ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
+	if (ret < 0) {
+		pr_err("failed to init sc16is7xx spi --> %d\n", ret);
+		goto err_spi;
+	}
+#endif
+	return ret;
+
+#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
+err_spi:
+#endif
+#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
+	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
+err_i2c:
+#endif
+	uart_unregister_driver(&sc16is7xx_uart);
+	return ret;
+}
+module_init(sc16is7xx_init);
+
+static void __exit sc16is7xx_exit(void)
+{
+#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
+	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
+#endif
+
+#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
+	spi_unregister_driver(&sc16is7xx_spi_uart_driver);
+#endif
+	uart_unregister_driver(&sc16is7xx_uart);
+}
+module_exit(sc16is7xx_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
+MODULE_DESCRIPTION("SC16IS7XX serial driver");
diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
new file mode 100644
index 000000000..2be2c1098
--- /dev/null
+++ b/drivers/tty/serial/sccnxp.c
@@ -0,0 +1,1057 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  NXP (Philips) SCC+++(SCN+++) serial driver
+ *
+ *  Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru>
+ *
+ *  Based on sc26xx.c, by Thomas Bogendörfer (tsbogend@alpha.franken.de)
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/device.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/io.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/serial-sccnxp.h>
+#include <linux/regulator/consumer.h>
+
+#define SCCNXP_NAME			"uart-sccnxp"
+#define SCCNXP_MAJOR			204
+#define SCCNXP_MINOR			205
+
+#define SCCNXP_MR_REG			(0x00)
+#	define MR0_BAUD_NORMAL		(0 << 0)
+#	define MR0_BAUD_EXT1		(1 << 0)
+#	define MR0_BAUD_EXT2		(5 << 0)
+#	define MR0_FIFO			(1 << 3)
+#	define MR0_TXLVL		(1 << 4)
+#	define MR1_BITS_5		(0 << 0)
+#	define MR1_BITS_6		(1 << 0)
+#	define MR1_BITS_7		(2 << 0)
+#	define MR1_BITS_8		(3 << 0)
+#	define MR1_PAR_EVN		(0 << 2)
+#	define MR1_PAR_ODD		(1 << 2)
+#	define MR1_PAR_NO		(4 << 2)
+#	define MR2_STOP1		(7 << 0)
+#	define MR2_STOP2		(0xf << 0)
+#define SCCNXP_SR_REG			(0x01)
+#	define SR_RXRDY			(1 << 0)
+#	define SR_FULL			(1 << 1)
+#	define SR_TXRDY			(1 << 2)
+#	define SR_TXEMT			(1 << 3)
+#	define SR_OVR			(1 << 4)
+#	define SR_PE			(1 << 5)
+#	define SR_FE			(1 << 6)
+#	define SR_BRK			(1 << 7)
+#define SCCNXP_CSR_REG			(SCCNXP_SR_REG)
+#	define CSR_TIMER_MODE		(0x0d)
+#define SCCNXP_CR_REG			(0x02)
+#	define CR_RX_ENABLE		(1 << 0)
+#	define CR_RX_DISABLE		(1 << 1)
+#	define CR_TX_ENABLE		(1 << 2)
+#	define CR_TX_DISABLE		(1 << 3)
+#	define CR_CMD_MRPTR1		(0x01 << 4)
+#	define CR_CMD_RX_RESET		(0x02 << 4)
+#	define CR_CMD_TX_RESET		(0x03 << 4)
+#	define CR_CMD_STATUS_RESET	(0x04 << 4)
+#	define CR_CMD_BREAK_RESET	(0x05 << 4)
+#	define CR_CMD_START_BREAK	(0x06 << 4)
+#	define CR_CMD_STOP_BREAK	(0x07 << 4)
+#	define CR_CMD_MRPTR0		(0x0b << 4)
+#define SCCNXP_RHR_REG			(0x03)
+#define SCCNXP_THR_REG			SCCNXP_RHR_REG
+#define SCCNXP_IPCR_REG			(0x04)
+#define SCCNXP_ACR_REG			SCCNXP_IPCR_REG
+#	define ACR_BAUD0		(0 << 7)
+#	define ACR_BAUD1		(1 << 7)
+#	define ACR_TIMER_MODE		(6 << 4)
+#define SCCNXP_ISR_REG			(0x05)
+#define SCCNXP_IMR_REG			SCCNXP_ISR_REG
+#	define IMR_TXRDY		(1 << 0)
+#	define IMR_RXRDY		(1 << 1)
+#	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
+#	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
+#define SCCNXP_CTPU_REG			(0x06)
+#define SCCNXP_CTPL_REG			(0x07)
+#define SCCNXP_IPR_REG			(0x0d)
+#define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
+#define SCCNXP_SOP_REG			(0x0e)
+#define SCCNXP_START_COUNTER_REG	SCCNXP_SOP_REG
+#define SCCNXP_ROP_REG			(0x0f)
+
+/* Route helpers */
+#define MCTRL_MASK(sig)			(0xf << (sig))
+#define MCTRL_IBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_IP0)
+#define MCTRL_OBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_OP0)
+
+#define SCCNXP_HAVE_IO		0x00000001
+#define SCCNXP_HAVE_MR0		0x00000002
+
+struct sccnxp_chip {
+	const char		*name;
+	unsigned int		nr;
+	unsigned long		freq_min;
+	unsigned long		freq_std;
+	unsigned long		freq_max;
+	unsigned int		flags;
+	unsigned int		fifosize;
+	/* Time between read/write cycles */
+	unsigned int		trwd;
+};
+
+struct sccnxp_port {
+	struct uart_driver	uart;
+	struct uart_port	port[SCCNXP_MAX_UARTS];
+	bool			opened[SCCNXP_MAX_UARTS];
+
+	int			irq;
+	u8			imr;
+
+	struct sccnxp_chip	*chip;
+
+#ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
+	struct console		console;
+#endif
+
+	spinlock_t		lock;
+
+	bool			poll;
+	struct timer_list	timer;
+
+	struct sccnxp_pdata	pdata;
+
+	struct regulator	*regulator;
+};
+
+static const struct sccnxp_chip sc2681 = {
+	.name		= "SC2681",
+	.nr		= 2,
+	.freq_min	= 1000000,
+	.freq_std	= 3686400,
+	.freq_max	= 4000000,
+	.flags		= SCCNXP_HAVE_IO,
+	.fifosize	= 3,
+	.trwd		= 200,
+};
+
+static const struct sccnxp_chip sc2691 = {
+	.name		= "SC2691",
+	.nr		= 1,
+	.freq_min	= 1000000,
+	.freq_std	= 3686400,
+	.freq_max	= 4000000,
+	.flags		= 0,
+	.fifosize	= 3,
+	.trwd		= 150,
+};
+
+static const struct sccnxp_chip sc2692 = {
+	.name		= "SC2692",
+	.nr		= 2,
+	.freq_min	= 1000000,
+	.freq_std	= 3686400,
+	.freq_max	= 4000000,
+	.flags		= SCCNXP_HAVE_IO,
+	.fifosize	= 3,
+	.trwd		= 30,
+};
+
+static const struct sccnxp_chip sc2891 = {
+	.name		= "SC2891",
+	.nr		= 1,
+	.freq_min	= 100000,
+	.freq_std	= 3686400,
+	.freq_max	= 8000000,
+	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
+	.fifosize	= 16,
+	.trwd		= 27,
+};
+
+static const struct sccnxp_chip sc2892 = {
+	.name		= "SC2892",
+	.nr		= 2,
+	.freq_min	= 100000,
+	.freq_std	= 3686400,
+	.freq_max	= 8000000,
+	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
+	.fifosize	= 16,
+	.trwd		= 17,
+};
+
+static const struct sccnxp_chip sc28202 = {
+	.name		= "SC28202",
+	.nr		= 2,
+	.freq_min	= 1000000,
+	.freq_std	= 14745600,
+	.freq_max	= 50000000,
+	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
+	.fifosize	= 256,
+	.trwd		= 10,
+};
+
+static const struct sccnxp_chip sc68681 = {
+	.name		= "SC68681",
+	.nr		= 2,
+	.freq_min	= 1000000,
+	.freq_std	= 3686400,
+	.freq_max	= 4000000,
+	.flags		= SCCNXP_HAVE_IO,
+	.fifosize	= 3,
+	.trwd		= 200,
+};
+
+static const struct sccnxp_chip sc68692 = {
+	.name		= "SC68692",
+	.nr		= 2,
+	.freq_min	= 1000000,
+	.freq_std	= 3686400,
+	.freq_max	= 4000000,
+	.flags		= SCCNXP_HAVE_IO,
+	.fifosize	= 3,
+	.trwd		= 200,
+};
+
+static u8 sccnxp_read(struct uart_port *port, u8 reg)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	u8 ret;
+
+	ret = readb(port->membase + (reg << port->regshift));
+
+	ndelay(s->chip->trwd);
+
+	return ret;
+}
+
+static void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	writeb(v, port->membase + (reg << port->regshift));
+
+	ndelay(s->chip->trwd);
+}
+
+static u8 sccnxp_port_read(struct uart_port *port, u8 reg)
+{
+	return sccnxp_read(port, (port->line << 3) + reg);
+}
+
+static void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
+{
+	sccnxp_write(port, (port->line << 3) + reg, v);
+}
+
+static int sccnxp_update_best_err(int a, int b, int *besterr)
+{
+	int err = abs(a - b);
+
+	if (*besterr > err) {
+		*besterr = err;
+		return 0;
+	}
+
+	return 1;
+}
+
+static const struct {
+	u8	csr;
+	u8	acr;
+	u8	mr0;
+	int	baud;
+} baud_std[] = {
+	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
+	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
+	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
+	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
+	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
+	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
+	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
+	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
+	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
+	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
+	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
+	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
+	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
+	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
+	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
+	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
+	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
+	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
+	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
+	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
+	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
+	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
+	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
+	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
+	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
+	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
+	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
+	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
+	{ 0, 0, 0, 0 }
+};
+
+static int sccnxp_set_baud(struct uart_port *port, int baud)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	int div_std, tmp_baud, bestbaud = INT_MAX, besterr = INT_MAX;
+	struct sccnxp_chip *chip = s->chip;
+	u8 i, acr = 0, csr = 0, mr0 = 0;
+
+	/* Find divisor to load to the timer preset registers */
+	div_std = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * baud);
+	if ((div_std >= 2) && (div_std <= 0xffff)) {
+		bestbaud = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * div_std);
+		sccnxp_update_best_err(baud, bestbaud, &besterr);
+		csr = CSR_TIMER_MODE;
+		sccnxp_port_write(port, SCCNXP_CTPU_REG, div_std >> 8);
+		sccnxp_port_write(port, SCCNXP_CTPL_REG, div_std);
+		/* Issue start timer/counter command */
+		sccnxp_port_read(port, SCCNXP_START_COUNTER_REG);
+	}
+
+	/* Find best baud from table */
+	for (i = 0; baud_std[i].baud && besterr; i++) {
+		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
+			continue;
+		div_std = DIV_ROUND_CLOSEST(chip->freq_std, baud_std[i].baud);
+		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
+		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
+			acr = baud_std[i].acr;
+			csr = baud_std[i].csr;
+			mr0 = baud_std[i].mr0;
+			bestbaud = tmp_baud;
+		}
+	}
+
+	if (chip->flags & SCCNXP_HAVE_MR0) {
+		/* Enable FIFO, set half level for TX */
+		mr0 |= MR0_FIFO | MR0_TXLVL;
+		/* Update MR0 */
+		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
+		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
+	}
+
+	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
+	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
+
+	if (baud != bestbaud)
+		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
+			baud, bestbaud);
+
+	return bestbaud;
+}
+
+static void sccnxp_enable_irq(struct uart_port *port, int mask)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	s->imr |= mask << (port->line * 4);
+	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
+}
+
+static void sccnxp_disable_irq(struct uart_port *port, int mask)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	s->imr &= ~(mask << (port->line * 4));
+	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
+}
+
+static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
+{
+	u8 bitmask;
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
+		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
+		if (state)
+			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
+		else
+			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
+	}
+}
+
+static void sccnxp_handle_rx(struct uart_port *port)
+{
+	u8 sr, ch, flag;
+
+	for (;;) {
+		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
+		if (!(sr & SR_RXRDY))
+			break;
+		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
+
+		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
+
+		port->icount.rx++;
+		flag = TTY_NORMAL;
+
+		if (unlikely(sr)) {
+			if (sr & SR_BRK) {
+				port->icount.brk++;
+				sccnxp_port_write(port, SCCNXP_CR_REG,
+						  CR_CMD_BREAK_RESET);
+				if (uart_handle_break(port))
+					continue;
+			} else if (sr & SR_PE)
+				port->icount.parity++;
+			else if (sr & SR_FE)
+				port->icount.frame++;
+			else if (sr & SR_OVR) {
+				port->icount.overrun++;
+				sccnxp_port_write(port, SCCNXP_CR_REG,
+						  CR_CMD_STATUS_RESET);
+			}
+
+			sr &= port->read_status_mask;
+			if (sr & SR_BRK)
+				flag = TTY_BREAK;
+			else if (sr & SR_PE)
+				flag = TTY_PARITY;
+			else if (sr & SR_FE)
+				flag = TTY_FRAME;
+			else if (sr & SR_OVR)
+				flag = TTY_OVERRUN;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		if (sr & port->ignore_status_mask)
+			continue;
+
+		uart_insert_char(port, sr, SR_OVR, ch, flag);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void sccnxp_handle_tx(struct uart_port *port)
+{
+	u8 sr;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	if (unlikely(port->x_char)) {
+		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		/* Disable TX if FIFO is empty */
+		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
+			sccnxp_disable_irq(port, IMR_TXRDY);
+
+			/* Set direction to input */
+			if (s->chip->flags & SCCNXP_HAVE_IO)
+				sccnxp_set_bit(port, DIR_OP, 0);
+		}
+		return;
+	}
+
+	while (!uart_circ_empty(xmit)) {
+		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
+		if (!(sr & SR_TXRDY))
+			break;
+
+		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
+		uart_xmit_advance(port, 1);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static void sccnxp_handle_events(struct sccnxp_port *s)
+{
+	int i;
+	u8 isr;
+
+	do {
+		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
+		isr &= s->imr;
+		if (!isr)
+			break;
+
+		for (i = 0; i < s->uart.nr; i++) {
+			if (s->opened[i] && (isr & ISR_RXRDY(i)))
+				sccnxp_handle_rx(&s->port[i]);
+			if (s->opened[i] && (isr & ISR_TXRDY(i)))
+				sccnxp_handle_tx(&s->port[i]);
+		}
+	} while (1);
+}
+
+static void sccnxp_timer(struct timer_list *t)
+{
+	struct sccnxp_port *s = from_timer(s, t, timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+	sccnxp_handle_events(s);
+	spin_unlock_irqrestore(&s->lock, flags);
+
+	mod_timer(&s->timer, jiffies + usecs_to_jiffies(s->pdata.poll_time_us));
+}
+
+static irqreturn_t sccnxp_ist(int irq, void *dev_id)
+{
+	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+	sccnxp_handle_events(s);
+	spin_unlock_irqrestore(&s->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static void sccnxp_start_tx(struct uart_port *port)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+
+	/* Set direction to output */
+	if (s->chip->flags & SCCNXP_HAVE_IO)
+		sccnxp_set_bit(port, DIR_OP, 1);
+
+	sccnxp_enable_irq(port, IMR_TXRDY);
+
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static void sccnxp_stop_tx(struct uart_port *port)
+{
+	/* Do nothing */
+}
+
+static void sccnxp_stop_rx(struct uart_port *port)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static unsigned int sccnxp_tx_empty(struct uart_port *port)
+{
+	u8 val;
+	unsigned long flags;
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	spin_lock_irqsave(&s->lock, flags);
+	val = sccnxp_port_read(port, SCCNXP_SR_REG);
+	spin_unlock_irqrestore(&s->lock, flags);
+
+	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
+}
+
+static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+
+	if (!(s->chip->flags & SCCNXP_HAVE_IO))
+		return;
+
+	spin_lock_irqsave(&s->lock, flags);
+
+	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
+	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
+
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static unsigned int sccnxp_get_mctrl(struct uart_port *port)
+{
+	u8 bitmask, ipr;
+	unsigned long flags;
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
+
+	if (!(s->chip->flags & SCCNXP_HAVE_IO))
+		return mctrl;
+
+	spin_lock_irqsave(&s->lock, flags);
+
+	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
+
+	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
+		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
+					  DSR_IP);
+		mctrl &= ~TIOCM_DSR;
+		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
+	}
+	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
+		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
+					  CTS_IP);
+		mctrl &= ~TIOCM_CTS;
+		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
+	}
+	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
+		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
+					  DCD_IP);
+		mctrl &= ~TIOCM_CAR;
+		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
+	}
+	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
+		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
+					  RNG_IP);
+		mctrl &= ~TIOCM_RNG;
+		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
+	}
+
+	spin_unlock_irqrestore(&s->lock, flags);
+
+	return mctrl;
+}
+
+static void sccnxp_break_ctl(struct uart_port *port, int break_state)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
+			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static void sccnxp_set_termios(struct uart_port *port,
+			       struct ktermios *termios,
+			       const struct ktermios *old)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+	u8 mr1, mr2;
+	int baud;
+
+	spin_lock_irqsave(&s->lock, flags);
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+
+	/* Disable RX & TX, reset break condition, status and FIFOs */
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
+					       CR_RX_DISABLE | CR_TX_DISABLE);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
+
+	/* Word size */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		mr1 = MR1_BITS_5;
+		break;
+	case CS6:
+		mr1 = MR1_BITS_6;
+		break;
+	case CS7:
+		mr1 = MR1_BITS_7;
+		break;
+	case CS8:
+	default:
+		mr1 = MR1_BITS_8;
+		break;
+	}
+
+	/* Parity */
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & PARODD)
+			mr1 |= MR1_PAR_ODD;
+	} else
+		mr1 |= MR1_PAR_NO;
+
+	/* Stop bits */
+	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
+
+	/* Update desired format */
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
+	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
+	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
+
+	/* Set read status mask */
+	port->read_status_mask = SR_OVR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= SR_PE | SR_FE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= SR_BRK;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNBRK)
+		port->ignore_status_mask |= SR_BRK;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= SR_PE;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
+
+	/* Setup baudrate */
+	baud = uart_get_baud_rate(port, termios, old, 50,
+				  (s->chip->flags & SCCNXP_HAVE_MR0) ?
+				  230400 : 38400);
+	baud = sccnxp_set_baud(port, baud);
+
+	/* Update timeout according to new baud rate */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* Report actual baudrate back to core */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	/* Enable RX & TX */
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
+
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static int sccnxp_startup(struct uart_port *port)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+
+	if (s->chip->flags & SCCNXP_HAVE_IO) {
+		/* Outputs are controlled manually */
+		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
+	}
+
+	/* Reset break condition, status and FIFOs */
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
+
+	/* Enable RX & TX */
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
+
+	/* Enable RX interrupt */
+	sccnxp_enable_irq(port, IMR_RXRDY);
+
+	s->opened[port->line] = 1;
+
+	spin_unlock_irqrestore(&s->lock, flags);
+
+	return 0;
+}
+
+static void sccnxp_shutdown(struct uart_port *port)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+
+	s->opened[port->line] = 0;
+
+	/* Disable interrupts */
+	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
+
+	/* Disable TX & RX */
+	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
+
+	/* Leave direction to input */
+	if (s->chip->flags & SCCNXP_HAVE_IO)
+		sccnxp_set_bit(port, DIR_OP, 0);
+
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static const char *sccnxp_type(struct uart_port *port)
+{
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
+	return (port->type == PORT_SC26XX) ? s->chip->name : NULL;
+}
+
+static void sccnxp_release_port(struct uart_port *port)
+{
+	/* Do nothing */
+}
+
+static int sccnxp_request_port(struct uart_port *port)
+{
+	/* Do nothing */
+	return 0;
+}
+
+static void sccnxp_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_SC26XX;
+}
+
+static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
+{
+	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
+		return 0;
+	if (s->irq == port->irq)
+		return 0;
+
+	return -EINVAL;
+}
+
+static const struct uart_ops sccnxp_ops = {
+	.tx_empty	= sccnxp_tx_empty,
+	.set_mctrl	= sccnxp_set_mctrl,
+	.get_mctrl	= sccnxp_get_mctrl,
+	.stop_tx	= sccnxp_stop_tx,
+	.start_tx	= sccnxp_start_tx,
+	.stop_rx	= sccnxp_stop_rx,
+	.break_ctl	= sccnxp_break_ctl,
+	.startup	= sccnxp_startup,
+	.shutdown	= sccnxp_shutdown,
+	.set_termios	= sccnxp_set_termios,
+	.type		= sccnxp_type,
+	.release_port	= sccnxp_release_port,
+	.request_port	= sccnxp_request_port,
+	.config_port	= sccnxp_config_port,
+	.verify_port	= sccnxp_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
+static void sccnxp_console_putchar(struct uart_port *port, unsigned char c)
+{
+	int tryes = 100000;
+
+	while (tryes--) {
+		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
+			sccnxp_port_write(port, SCCNXP_THR_REG, c);
+			break;
+		}
+		barrier();
+	}
+}
+
+static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
+{
+	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
+	struct uart_port *port = &s->port[co->index];
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->lock, flags);
+	uart_console_write(port, c, n, sccnxp_console_putchar);
+	spin_unlock_irqrestore(&s->lock, flags);
+}
+
+static int sccnxp_console_setup(struct console *co, char *options)
+{
+	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
+	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
+	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+#endif
+
+static const struct platform_device_id sccnxp_id_table[] = {
+	{ .name = "sc2681",	.driver_data = (kernel_ulong_t)&sc2681, },
+	{ .name = "sc2691",	.driver_data = (kernel_ulong_t)&sc2691, },
+	{ .name = "sc2692",	.driver_data = (kernel_ulong_t)&sc2692, },
+	{ .name = "sc2891",	.driver_data = (kernel_ulong_t)&sc2891, },
+	{ .name = "sc2892",	.driver_data = (kernel_ulong_t)&sc2892, },
+	{ .name = "sc28202",	.driver_data = (kernel_ulong_t)&sc28202, },
+	{ .name = "sc68681",	.driver_data = (kernel_ulong_t)&sc68681, },
+	{ .name = "sc68692",	.driver_data = (kernel_ulong_t)&sc68692, },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
+
+static int sccnxp_probe(struct platform_device *pdev)
+{
+	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct resource *res;
+	int i, ret, uartclk;
+	struct sccnxp_port *s;
+	void __iomem *membase;
+	struct clk *clk;
+
+	membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
+
+	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
+	if (!s) {
+		dev_err(&pdev->dev, "Error allocating port structure\n");
+		return -ENOMEM;
+	}
+	platform_set_drvdata(pdev, s);
+
+	spin_lock_init(&s->lock);
+
+	s->chip = (struct sccnxp_chip *)pdev->id_entry->driver_data;
+
+	s->regulator = devm_regulator_get(&pdev->dev, "vcc");
+	if (!IS_ERR(s->regulator)) {
+		ret = regulator_enable(s->regulator);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Failed to enable regulator: %i\n", ret);
+			return ret;
+		}
+	} else if (PTR_ERR(s->regulator) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		if (ret == -EPROBE_DEFER)
+			goto err_out;
+		uartclk = 0;
+	} else {
+		uartclk = clk_get_rate(clk);
+	}
+
+	if (!uartclk) {
+		dev_notice(&pdev->dev, "Using default clock frequency\n");
+		uartclk = s->chip->freq_std;
+	}
+
+	/* Check input frequency */
+	if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {
+		dev_err(&pdev->dev, "Frequency out of bounds\n");
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	if (pdata)
+		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
+
+	if (s->pdata.poll_time_us) {
+		dev_info(&pdev->dev, "Using poll mode, resolution %u usecs\n",
+			 s->pdata.poll_time_us);
+		s->poll = 1;
+	}
+
+	if (!s->poll) {
+		s->irq = platform_get_irq(pdev, 0);
+		if (s->irq < 0) {
+			ret = -ENXIO;
+			goto err_out;
+		}
+	}
+
+	s->uart.owner		= THIS_MODULE;
+	s->uart.dev_name	= "ttySC";
+	s->uart.major		= SCCNXP_MAJOR;
+	s->uart.minor		= SCCNXP_MINOR;
+	s->uart.nr		= s->chip->nr;
+#ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
+	s->uart.cons		= &s->console;
+	s->uart.cons->device	= uart_console_device;
+	s->uart.cons->write	= sccnxp_console_write;
+	s->uart.cons->setup	= sccnxp_console_setup;
+	s->uart.cons->flags	= CON_PRINTBUFFER;
+	s->uart.cons->index	= -1;
+	s->uart.cons->data	= s;
+	strcpy(s->uart.cons->name, "ttySC");
+#endif
+	ret = uart_register_driver(&s->uart);
+	if (ret) {
+		dev_err(&pdev->dev, "Registering UART driver failed\n");
+		goto err_out;
+	}
+
+	for (i = 0; i < s->uart.nr; i++) {
+		s->port[i].line		= i;
+		s->port[i].dev		= &pdev->dev;
+		s->port[i].irq		= s->irq;
+		s->port[i].type		= PORT_SC26XX;
+		s->port[i].fifosize	= s->chip->fifosize;
+		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
+		s->port[i].iotype	= UPIO_MEM;
+		s->port[i].mapbase	= res->start;
+		s->port[i].membase	= membase;
+		s->port[i].regshift	= s->pdata.reg_shift;
+		s->port[i].uartclk	= uartclk;
+		s->port[i].ops		= &sccnxp_ops;
+		s->port[i].has_sysrq = IS_ENABLED(CONFIG_SERIAL_SCCNXP_CONSOLE);
+		uart_add_one_port(&s->uart, &s->port[i]);
+		/* Set direction to input */
+		if (s->chip->flags & SCCNXP_HAVE_IO)
+			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
+	}
+
+	/* Disable interrupts */
+	s->imr = 0;
+	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
+
+	if (!s->poll) {
+		ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL,
+						sccnxp_ist,
+						IRQF_TRIGGER_FALLING |
+						IRQF_ONESHOT,
+						dev_name(&pdev->dev), s);
+		if (!ret)
+			return 0;
+
+		dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
+	} else {
+		timer_setup(&s->timer, sccnxp_timer, 0);
+		mod_timer(&s->timer, jiffies +
+			  usecs_to_jiffies(s->pdata.poll_time_us));
+		return 0;
+	}
+
+	uart_unregister_driver(&s->uart);
+err_out:
+	if (!IS_ERR(s->regulator))
+		regulator_disable(s->regulator);
+
+	return ret;
+}
+
+static int sccnxp_remove(struct platform_device *pdev)
+{
+	int i;
+	struct sccnxp_port *s = platform_get_drvdata(pdev);
+
+	if (!s->poll)
+		devm_free_irq(&pdev->dev, s->irq, s);
+	else
+		del_timer_sync(&s->timer);
+
+	for (i = 0; i < s->uart.nr; i++)
+		uart_remove_one_port(&s->uart, &s->port[i]);
+
+	uart_unregister_driver(&s->uart);
+
+	if (!IS_ERR(s->regulator))
+		return regulator_disable(s->regulator);
+
+	return 0;
+}
+
+static struct platform_driver sccnxp_uart_driver = {
+	.driver = {
+		.name	= SCCNXP_NAME,
+	},
+	.probe		= sccnxp_probe,
+	.remove		= sccnxp_remove,
+	.id_table	= sccnxp_id_table,
+};
+module_platform_driver(sccnxp_uart_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("SCCNXP serial driver");
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
new file mode 100644
index 000000000..d4ec943cb
--- /dev/null
+++ b/drivers/tty/serial/serial-tegra.c
@@ -0,0 +1,1700 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * serial_tegra.c
+ *
+ * High-speed serial driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (c) 2012-2019, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pagemap.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/termios.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define TEGRA_UART_TYPE				"TEGRA_UART"
+#define TX_EMPTY_STATUS				(UART_LSR_TEMT | UART_LSR_THRE)
+#define BYTES_TO_ALIGN(x)			((unsigned long)(x) & 0x3)
+
+#define TEGRA_UART_RX_DMA_BUFFER_SIZE		4096
+#define TEGRA_UART_LSR_TXFIFO_FULL		0x100
+#define TEGRA_UART_IER_EORD			0x20
+#define TEGRA_UART_MCR_RTS_EN			0x40
+#define TEGRA_UART_MCR_CTS_EN			0x20
+#define TEGRA_UART_LSR_ANY			(UART_LSR_OE | UART_LSR_BI | \
+						UART_LSR_PE | UART_LSR_FE)
+#define TEGRA_UART_IRDA_CSR			0x08
+#define TEGRA_UART_SIR_ENABLED			0x80
+
+#define TEGRA_UART_TX_PIO			1
+#define TEGRA_UART_TX_DMA			2
+#define TEGRA_UART_MIN_DMA			16
+#define TEGRA_UART_FIFO_SIZE			32
+
+/*
+ * Tx fifo trigger level setting in tegra uart is in
+ * reverse way then conventional uart.
+ */
+#define TEGRA_UART_TX_TRIG_16B			0x00
+#define TEGRA_UART_TX_TRIG_8B			0x10
+#define TEGRA_UART_TX_TRIG_4B			0x20
+#define TEGRA_UART_TX_TRIG_1B			0x30
+
+#define TEGRA_UART_MAXIMUM			8
+
+/* Default UART setting when started: 115200 no parity, stop, 8 data bits */
+#define TEGRA_UART_DEFAULT_BAUD			115200
+#define TEGRA_UART_DEFAULT_LSR			UART_LCR_WLEN8
+
+/* Tx transfer mode */
+#define TEGRA_TX_PIO				1
+#define TEGRA_TX_DMA				2
+
+#define TEGRA_UART_FCR_IIR_FIFO_EN		0x40
+
+/**
+ * struct tegra_uart_chip_data: SOC specific data.
+ *
+ * @tx_fifo_full_status: Status flag available for checking tx fifo full.
+ * @allow_txfifo_reset_fifo_mode: allow_tx fifo reset with fifo mode or not.
+ *			Tegra30 does not allow this.
+ * @support_clk_src_div: Clock source support the clock divider.
+ * @fifo_mode_enable_status: Is FIFO mode enabled?
+ * @uart_max_port: Maximum number of UART ports
+ * @max_dma_burst_bytes: Maximum size of DMA bursts
+ * @error_tolerance_low_range: Lowest number in the error tolerance range
+ * @error_tolerance_high_range: Highest number in the error tolerance range
+ */
+struct tegra_uart_chip_data {
+	bool	tx_fifo_full_status;
+	bool	allow_txfifo_reset_fifo_mode;
+	bool	support_clk_src_div;
+	bool	fifo_mode_enable_status;
+	int	uart_max_port;
+	int	max_dma_burst_bytes;
+	int	error_tolerance_low_range;
+	int	error_tolerance_high_range;
+};
+
+struct tegra_baud_tolerance {
+	u32 lower_range_baud;
+	u32 upper_range_baud;
+	s32 tolerance;
+};
+
+struct tegra_uart_port {
+	struct uart_port			uport;
+	const struct tegra_uart_chip_data	*cdata;
+
+	struct clk				*uart_clk;
+	struct reset_control			*rst;
+	unsigned int				current_baud;
+
+	/* Register shadow */
+	unsigned long				fcr_shadow;
+	unsigned long				mcr_shadow;
+	unsigned long				lcr_shadow;
+	unsigned long				ier_shadow;
+	bool					rts_active;
+
+	int					tx_in_progress;
+	unsigned int				tx_bytes;
+
+	bool					enable_modem_interrupt;
+
+	bool					rx_timeout;
+	int					rx_in_progress;
+	int					symb_bit;
+
+	struct dma_chan				*rx_dma_chan;
+	struct dma_chan				*tx_dma_chan;
+	dma_addr_t				rx_dma_buf_phys;
+	dma_addr_t				tx_dma_buf_phys;
+	unsigned char				*rx_dma_buf_virt;
+	unsigned char				*tx_dma_buf_virt;
+	struct dma_async_tx_descriptor		*tx_dma_desc;
+	struct dma_async_tx_descriptor		*rx_dma_desc;
+	dma_cookie_t				tx_cookie;
+	dma_cookie_t				rx_cookie;
+	unsigned int				tx_bytes_requested;
+	unsigned int				rx_bytes_requested;
+	struct tegra_baud_tolerance		*baud_tolerance;
+	int					n_adjustable_baud_rates;
+	int					required_rate;
+	int					configured_rate;
+	bool					use_rx_pio;
+	bool					use_tx_pio;
+	bool					rx_dma_active;
+};
+
+static void tegra_uart_start_next_tx(struct tegra_uart_port *tup);
+static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup);
+static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
+					bool dma_to_memory);
+
+static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup,
+		unsigned long reg)
+{
+	return readl(tup->uport.membase + (reg << tup->uport.regshift));
+}
+
+static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val,
+	unsigned long reg)
+{
+	writel(val, tup->uport.membase + (reg << tup->uport.regshift));
+}
+
+static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u)
+{
+	return container_of(u, struct tegra_uart_port, uport);
+}
+
+static unsigned int tegra_uart_get_mctrl(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+
+	/*
+	 * RI - Ring detector is active
+	 * CD/DCD/CAR - Carrier detect is always active. For some reason
+	 *	linux has different names for carrier detect.
+	 * DSR - Data Set ready is active as the hardware doesn't support it.
+	 *	Don't know if the linux support this yet?
+	 * CTS - Clear to send. Always set to active, as the hardware handles
+	 *	CTS automatically.
+	 */
+	if (tup->enable_modem_interrupt)
+		return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS;
+	return TIOCM_CTS;
+}
+
+static void set_rts(struct tegra_uart_port *tup, bool active)
+{
+	unsigned long mcr;
+
+	mcr = tup->mcr_shadow;
+	if (active)
+		mcr |= TEGRA_UART_MCR_RTS_EN;
+	else
+		mcr &= ~TEGRA_UART_MCR_RTS_EN;
+	if (mcr != tup->mcr_shadow) {
+		tegra_uart_write(tup, mcr, UART_MCR);
+		tup->mcr_shadow = mcr;
+	}
+}
+
+static void set_dtr(struct tegra_uart_port *tup, bool active)
+{
+	unsigned long mcr;
+
+	mcr = tup->mcr_shadow;
+	if (active)
+		mcr |= UART_MCR_DTR;
+	else
+		mcr &= ~UART_MCR_DTR;
+	if (mcr != tup->mcr_shadow) {
+		tegra_uart_write(tup, mcr, UART_MCR);
+		tup->mcr_shadow = mcr;
+	}
+}
+
+static void set_loopbk(struct tegra_uart_port *tup, bool active)
+{
+	unsigned long mcr = tup->mcr_shadow;
+
+	if (active)
+		mcr |= UART_MCR_LOOP;
+	else
+		mcr &= ~UART_MCR_LOOP;
+
+	if (mcr != tup->mcr_shadow) {
+		tegra_uart_write(tup, mcr, UART_MCR);
+		tup->mcr_shadow = mcr;
+	}
+}
+
+static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	int enable;
+
+	tup->rts_active = !!(mctrl & TIOCM_RTS);
+	set_rts(tup, tup->rts_active);
+
+	enable = !!(mctrl & TIOCM_DTR);
+	set_dtr(tup, enable);
+
+	enable = !!(mctrl & TIOCM_LOOP);
+	set_loopbk(tup, enable);
+}
+
+static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	unsigned long lcr;
+
+	lcr = tup->lcr_shadow;
+	if (break_ctl)
+		lcr |= UART_LCR_SBC;
+	else
+		lcr &= ~UART_LCR_SBC;
+	tegra_uart_write(tup, lcr, UART_LCR);
+	tup->lcr_shadow = lcr;
+}
+
+/**
+ * tegra_uart_wait_cycle_time: Wait for N UART clock periods
+ *
+ * @tup:	Tegra serial port data structure.
+ * @cycles:	Number of clock periods to wait.
+ *
+ * Tegra UARTs are clocked at 16X the baud/bit rate and hence the UART
+ * clock speed is 16X the current baud rate.
+ */
+static void tegra_uart_wait_cycle_time(struct tegra_uart_port *tup,
+				       unsigned int cycles)
+{
+	if (tup->current_baud)
+		udelay(DIV_ROUND_UP(cycles * 1000000, tup->current_baud * 16));
+}
+
+/* Wait for a symbol-time. */
+static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
+		unsigned int syms)
+{
+	if (tup->current_baud)
+		udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000,
+			tup->current_baud));
+}
+
+static int tegra_uart_wait_fifo_mode_enabled(struct tegra_uart_port *tup)
+{
+	unsigned long iir;
+	unsigned int tmout = 100;
+
+	do {
+		iir = tegra_uart_read(tup, UART_IIR);
+		if (iir & TEGRA_UART_FCR_IIR_FIFO_EN)
+			return 0;
+		udelay(1);
+	} while (--tmout);
+
+	return -ETIMEDOUT;
+}
+
+static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
+{
+	unsigned long fcr = tup->fcr_shadow;
+	unsigned int lsr, tmout = 10000;
+
+	if (tup->rts_active)
+		set_rts(tup, false);
+
+	if (tup->cdata->allow_txfifo_reset_fifo_mode) {
+		fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+		tegra_uart_write(tup, fcr, UART_FCR);
+	} else {
+		fcr &= ~UART_FCR_ENABLE_FIFO;
+		tegra_uart_write(tup, fcr, UART_FCR);
+		udelay(60);
+		fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+		tegra_uart_write(tup, fcr, UART_FCR);
+		fcr |= UART_FCR_ENABLE_FIFO;
+		tegra_uart_write(tup, fcr, UART_FCR);
+		if (tup->cdata->fifo_mode_enable_status)
+			tegra_uart_wait_fifo_mode_enabled(tup);
+	}
+
+	/* Dummy read to ensure the write is posted */
+	tegra_uart_read(tup, UART_SCR);
+
+	/*
+	 * For all tegra devices (up to t210), there is a hardware issue that
+	 * requires software to wait for 32 UART clock periods for the flush
+	 * to propagate, otherwise data could be lost.
+	 */
+	tegra_uart_wait_cycle_time(tup, 32);
+
+	do {
+		lsr = tegra_uart_read(tup, UART_LSR);
+		if ((lsr & UART_LSR_TEMT) && !(lsr & UART_LSR_DR))
+			break;
+		udelay(1);
+	} while (--tmout);
+
+	if (tup->rts_active)
+		set_rts(tup, true);
+}
+
+static long tegra_get_tolerance_rate(struct tegra_uart_port *tup,
+				     unsigned int baud, long rate)
+{
+	int i;
+
+	for (i = 0; i < tup->n_adjustable_baud_rates; ++i) {
+		if (baud >= tup->baud_tolerance[i].lower_range_baud &&
+		    baud <= tup->baud_tolerance[i].upper_range_baud)
+			return (rate + (rate *
+				tup->baud_tolerance[i].tolerance) / 10000);
+	}
+
+	return rate;
+}
+
+static int tegra_check_rate_in_range(struct tegra_uart_port *tup)
+{
+	long diff;
+
+	diff = ((long)(tup->configured_rate - tup->required_rate) * 10000)
+		/ tup->required_rate;
+	if (diff < (tup->cdata->error_tolerance_low_range * 100) ||
+	    diff > (tup->cdata->error_tolerance_high_range * 100)) {
+		dev_err(tup->uport.dev,
+			"configured baud rate is out of range by %ld", diff);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
+{
+	unsigned long rate;
+	unsigned int divisor;
+	unsigned long lcr;
+	unsigned long flags;
+	int ret;
+
+	if (tup->current_baud == baud)
+		return 0;
+
+	if (tup->cdata->support_clk_src_div) {
+		rate = baud * 16;
+		tup->required_rate = rate;
+
+		if (tup->n_adjustable_baud_rates)
+			rate = tegra_get_tolerance_rate(tup, baud, rate);
+
+		ret = clk_set_rate(tup->uart_clk, rate);
+		if (ret < 0) {
+			dev_err(tup->uport.dev,
+				"clk_set_rate() failed for rate %lu\n", rate);
+			return ret;
+		}
+		tup->configured_rate = clk_get_rate(tup->uart_clk);
+		divisor = 1;
+		ret = tegra_check_rate_in_range(tup);
+		if (ret < 0)
+			return ret;
+	} else {
+		rate = clk_get_rate(tup->uart_clk);
+		divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
+	}
+
+	spin_lock_irqsave(&tup->uport.lock, flags);
+	lcr = tup->lcr_shadow;
+	lcr |= UART_LCR_DLAB;
+	tegra_uart_write(tup, lcr, UART_LCR);
+
+	tegra_uart_write(tup, divisor & 0xFF, UART_TX);
+	tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER);
+
+	lcr &= ~UART_LCR_DLAB;
+	tegra_uart_write(tup, lcr, UART_LCR);
+
+	/* Dummy read to ensure the write is posted */
+	tegra_uart_read(tup, UART_SCR);
+	spin_unlock_irqrestore(&tup->uport.lock, flags);
+
+	tup->current_baud = baud;
+
+	/* wait two character intervals at new rate */
+	tegra_uart_wait_sym_time(tup, 2);
+	return 0;
+}
+
+static u8 tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
+			unsigned long lsr)
+{
+	u8 flag = TTY_NORMAL;
+
+	if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
+		if (lsr & UART_LSR_OE) {
+			/* Overrun error */
+			flag = TTY_OVERRUN;
+			tup->uport.icount.overrun++;
+			dev_dbg(tup->uport.dev, "Got overrun errors\n");
+		} else if (lsr & UART_LSR_PE) {
+			/* Parity error */
+			flag = TTY_PARITY;
+			tup->uport.icount.parity++;
+			dev_dbg(tup->uport.dev, "Got Parity errors\n");
+		} else if (lsr & UART_LSR_FE) {
+			flag = TTY_FRAME;
+			tup->uport.icount.frame++;
+			dev_dbg(tup->uport.dev, "Got frame errors\n");
+		} else if (lsr & UART_LSR_BI) {
+			/*
+			 * Break error
+			 * If FIFO read error without any data, reset Rx FIFO
+			 */
+			if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
+				tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
+			if (tup->uport.ignore_status_mask & UART_LSR_BI)
+				return TTY_BREAK;
+			flag = TTY_BREAK;
+			tup->uport.icount.brk++;
+			dev_dbg(tup->uport.dev, "Got Break\n");
+		}
+		uart_insert_char(&tup->uport, lsr, UART_LSR_OE, 0, flag);
+	}
+
+	return flag;
+}
+
+static int tegra_uart_request_port(struct uart_port *u)
+{
+	return 0;
+}
+
+static void tegra_uart_release_port(struct uart_port *u)
+{
+	/* Nothing to do here */
+}
+
+static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes)
+{
+	struct circ_buf *xmit = &tup->uport.state->xmit;
+	int i;
+
+	for (i = 0; i < max_bytes; i++) {
+		BUG_ON(uart_circ_empty(xmit));
+		if (tup->cdata->tx_fifo_full_status) {
+			unsigned long lsr = tegra_uart_read(tup, UART_LSR);
+			if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL))
+				break;
+		}
+		tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX);
+		uart_xmit_advance(&tup->uport, 1);
+	}
+}
+
+static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup,
+		unsigned int bytes)
+{
+	if (bytes > TEGRA_UART_MIN_DMA)
+		bytes = TEGRA_UART_MIN_DMA;
+
+	tup->tx_in_progress = TEGRA_UART_TX_PIO;
+	tup->tx_bytes = bytes;
+	tup->ier_shadow |= UART_IER_THRI;
+	tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+}
+
+static void tegra_uart_tx_dma_complete(void *args)
+{
+	struct tegra_uart_port *tup = args;
+	struct circ_buf *xmit = &tup->uport.state->xmit;
+	struct dma_tx_state state;
+	unsigned long flags;
+	unsigned int count;
+
+	dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
+	count = tup->tx_bytes_requested - state.residue;
+	async_tx_ack(tup->tx_dma_desc);
+	spin_lock_irqsave(&tup->uport.lock, flags);
+	uart_xmit_advance(&tup->uport, count);
+	tup->tx_in_progress = 0;
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&tup->uport);
+	tegra_uart_start_next_tx(tup);
+	spin_unlock_irqrestore(&tup->uport.lock, flags);
+}
+
+static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
+		unsigned long count)
+{
+	struct circ_buf *xmit = &tup->uport.state->xmit;
+	dma_addr_t tx_phys_addr;
+
+	tup->tx_bytes = count & ~(0xF);
+	tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail;
+
+	dma_sync_single_for_device(tup->uport.dev, tx_phys_addr,
+				   tup->tx_bytes, DMA_TO_DEVICE);
+
+	tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan,
+				tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV,
+				DMA_PREP_INTERRUPT);
+	if (!tup->tx_dma_desc) {
+		dev_err(tup->uport.dev, "Not able to get desc for Tx\n");
+		return -EIO;
+	}
+
+	tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete;
+	tup->tx_dma_desc->callback_param = tup;
+	tup->tx_in_progress = TEGRA_UART_TX_DMA;
+	tup->tx_bytes_requested = tup->tx_bytes;
+	tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc);
+	dma_async_issue_pending(tup->tx_dma_chan);
+	return 0;
+}
+
+static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
+{
+	unsigned long tail;
+	unsigned long count;
+	struct circ_buf *xmit = &tup->uport.state->xmit;
+
+	if (!tup->current_baud)
+		return;
+
+	tail = (unsigned long)&xmit->buf[xmit->tail];
+	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (!count)
+		return;
+
+	if (tup->use_tx_pio || count < TEGRA_UART_MIN_DMA)
+		tegra_uart_start_pio_tx(tup, count);
+	else if (BYTES_TO_ALIGN(tail) > 0)
+		tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
+	else
+		tegra_uart_start_tx_dma(tup, count);
+}
+
+/* Called by serial core driver with u->lock taken. */
+static void tegra_uart_start_tx(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	struct circ_buf *xmit = &u->state->xmit;
+
+	if (!uart_circ_empty(xmit) && !tup->tx_in_progress)
+		tegra_uart_start_next_tx(tup);
+}
+
+static unsigned int tegra_uart_tx_empty(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	unsigned int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&u->lock, flags);
+	if (!tup->tx_in_progress) {
+		unsigned long lsr = tegra_uart_read(tup, UART_LSR);
+		if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
+			ret = TIOCSER_TEMT;
+	}
+	spin_unlock_irqrestore(&u->lock, flags);
+	return ret;
+}
+
+static void tegra_uart_stop_tx(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	struct dma_tx_state state;
+	unsigned int count;
+
+	if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
+		return;
+
+	dmaengine_pause(tup->tx_dma_chan);
+	dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
+	dmaengine_terminate_all(tup->tx_dma_chan);
+	count = tup->tx_bytes_requested - state.residue;
+	async_tx_ack(tup->tx_dma_desc);
+	uart_xmit_advance(&tup->uport, count);
+	tup->tx_in_progress = 0;
+}
+
+static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup)
+{
+	struct circ_buf *xmit = &tup->uport.state->xmit;
+
+	tegra_uart_fill_tx_fifo(tup, tup->tx_bytes);
+	tup->tx_in_progress = 0;
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&tup->uport);
+	tegra_uart_start_next_tx(tup);
+}
+
+static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
+		struct tty_port *port)
+{
+	do {
+		unsigned long lsr = 0;
+		u8 ch, flag = TTY_NORMAL;
+
+		lsr = tegra_uart_read(tup, UART_LSR);
+		if (!(lsr & UART_LSR_DR))
+			break;
+
+		flag = tegra_uart_decode_rx_error(tup, lsr);
+		if (flag != TTY_NORMAL)
+			continue;
+
+		ch = (unsigned char) tegra_uart_read(tup, UART_RX);
+		tup->uport.icount.rx++;
+
+		if (uart_handle_sysrq_char(&tup->uport, ch))
+			continue;
+
+		if (tup->uport.ignore_status_mask & UART_LSR_DR)
+			continue;
+
+		tty_insert_flip_char(port, ch, flag);
+	} while (1);
+}
+
+static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
+				      struct tty_port *port,
+				      unsigned int count)
+{
+	int copied;
+
+	/* If count is zero, then there is no data to be copied */
+	if (!count)
+		return;
+
+	tup->uport.icount.rx += count;
+
+	if (tup->uport.ignore_status_mask & UART_LSR_DR)
+		return;
+
+	dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
+				count, DMA_FROM_DEVICE);
+	copied = tty_insert_flip_string(port,
+			((unsigned char *)(tup->rx_dma_buf_virt)), count);
+	if (copied != count) {
+		WARN_ON(1);
+		dev_err(tup->uport.dev, "RxData copy to tty layer failed\n");
+	}
+	dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
+				   count, DMA_TO_DEVICE);
+}
+
+static void do_handle_rx_pio(struct tegra_uart_port *tup)
+{
+	struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
+	struct tty_port *port = &tup->uport.state->port;
+
+	tegra_uart_handle_rx_pio(tup, port);
+	if (tty) {
+		tty_flip_buffer_push(port);
+		tty_kref_put(tty);
+	}
+}
+
+static void tegra_uart_rx_buffer_push(struct tegra_uart_port *tup,
+				      unsigned int residue)
+{
+	struct tty_port *port = &tup->uport.state->port;
+	unsigned int count;
+
+	async_tx_ack(tup->rx_dma_desc);
+	count = tup->rx_bytes_requested - residue;
+
+	/* If we are here, DMA is stopped */
+	tegra_uart_copy_rx_to_tty(tup, port, count);
+
+	do_handle_rx_pio(tup);
+}
+
+static void tegra_uart_rx_dma_complete(void *args)
+{
+	struct tegra_uart_port *tup = args;
+	struct uart_port *u = &tup->uport;
+	unsigned long flags;
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	spin_lock_irqsave(&u->lock, flags);
+
+	status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
+
+	if (status == DMA_IN_PROGRESS) {
+		dev_dbg(tup->uport.dev, "RX DMA is in progress\n");
+		goto done;
+	}
+
+	/* Deactivate flow control to stop sender */
+	if (tup->rts_active)
+		set_rts(tup, false);
+
+	tup->rx_dma_active = false;
+	tegra_uart_rx_buffer_push(tup, 0);
+	tegra_uart_start_rx_dma(tup);
+
+	/* Activate flow control to start transfer */
+	if (tup->rts_active)
+		set_rts(tup, true);
+
+done:
+	spin_unlock_irqrestore(&u->lock, flags);
+}
+
+static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup)
+{
+	struct dma_tx_state state;
+
+	if (!tup->rx_dma_active) {
+		do_handle_rx_pio(tup);
+		return;
+	}
+
+	dmaengine_pause(tup->rx_dma_chan);
+	dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
+	dmaengine_terminate_all(tup->rx_dma_chan);
+
+	tegra_uart_rx_buffer_push(tup, state.residue);
+	tup->rx_dma_active = false;
+}
+
+static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup)
+{
+	/* Deactivate flow control to stop sender */
+	if (tup->rts_active)
+		set_rts(tup, false);
+
+	tegra_uart_terminate_rx_dma(tup);
+
+	if (tup->rts_active)
+		set_rts(tup, true);
+}
+
+static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup)
+{
+	unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE;
+
+	if (tup->rx_dma_active)
+		return 0;
+
+	tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan,
+				tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
+				DMA_PREP_INTERRUPT);
+	if (!tup->rx_dma_desc) {
+		dev_err(tup->uport.dev, "Not able to get desc for Rx\n");
+		return -EIO;
+	}
+
+	tup->rx_dma_active = true;
+	tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete;
+	tup->rx_dma_desc->callback_param = tup;
+	tup->rx_bytes_requested = count;
+	tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc);
+	dma_async_issue_pending(tup->rx_dma_chan);
+	return 0;
+}
+
+static void tegra_uart_handle_modem_signal_change(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	unsigned long msr;
+
+	msr = tegra_uart_read(tup, UART_MSR);
+	if (!(msr & UART_MSR_ANY_DELTA))
+		return;
+
+	if (msr & UART_MSR_TERI)
+		tup->uport.icount.rng++;
+	if (msr & UART_MSR_DDSR)
+		tup->uport.icount.dsr++;
+	/* We may only get DDCD when HW init and reset */
+	if (msr & UART_MSR_DDCD)
+		uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD);
+	/* Will start/stop_tx accordingly */
+	if (msr & UART_MSR_DCTS)
+		uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS);
+}
+
+static irqreturn_t tegra_uart_isr(int irq, void *data)
+{
+	struct tegra_uart_port *tup = data;
+	struct uart_port *u = &tup->uport;
+	unsigned long iir;
+	unsigned long ier;
+	bool is_rx_start = false;
+	bool is_rx_int = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(&u->lock, flags);
+	while (1) {
+		iir = tegra_uart_read(tup, UART_IIR);
+		if (iir & UART_IIR_NO_INT) {
+			if (!tup->use_rx_pio && is_rx_int) {
+				tegra_uart_handle_rx_dma(tup);
+				if (tup->rx_in_progress) {
+					ier = tup->ier_shadow;
+					ier |= (UART_IER_RLSI | UART_IER_RTOIE |
+						TEGRA_UART_IER_EORD | UART_IER_RDI);
+					tup->ier_shadow = ier;
+					tegra_uart_write(tup, ier, UART_IER);
+				}
+			} else if (is_rx_start) {
+				tegra_uart_start_rx_dma(tup);
+			}
+			spin_unlock_irqrestore(&u->lock, flags);
+			return IRQ_HANDLED;
+		}
+
+		switch ((iir >> 1) & 0x7) {
+		case 0: /* Modem signal change interrupt */
+			tegra_uart_handle_modem_signal_change(u);
+			break;
+
+		case 1: /* Transmit interrupt only triggered when using PIO */
+			tup->ier_shadow &= ~UART_IER_THRI;
+			tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+			tegra_uart_handle_tx_pio(tup);
+			break;
+
+		case 4: /* End of data */
+		case 6: /* Rx timeout */
+			if (!tup->use_rx_pio) {
+				is_rx_int = tup->rx_in_progress;
+				/* Disable Rx interrupts */
+				ier = tup->ier_shadow;
+				ier &= ~(UART_IER_RDI | UART_IER_RLSI |
+					UART_IER_RTOIE | TEGRA_UART_IER_EORD);
+				tup->ier_shadow = ier;
+				tegra_uart_write(tup, ier, UART_IER);
+				break;
+			}
+			fallthrough;
+		case 2: /* Receive */
+			if (!tup->use_rx_pio) {
+				is_rx_start = tup->rx_in_progress;
+				tup->ier_shadow  &= ~UART_IER_RDI;
+				tegra_uart_write(tup, tup->ier_shadow,
+						 UART_IER);
+			} else {
+				do_handle_rx_pio(tup);
+			}
+			break;
+
+		case 3: /* Receive error */
+			tegra_uart_decode_rx_error(tup,
+					tegra_uart_read(tup, UART_LSR));
+			break;
+
+		case 5: /* break nothing to handle */
+		case 7: /* break nothing to handle */
+			break;
+		}
+	}
+}
+
+static void tegra_uart_stop_rx(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	struct tty_port *port = &tup->uport.state->port;
+	unsigned long ier;
+
+	if (tup->rts_active)
+		set_rts(tup, false);
+
+	if (!tup->rx_in_progress)
+		return;
+
+	tegra_uart_wait_sym_time(tup, 1); /* wait one character interval */
+
+	ier = tup->ier_shadow;
+	ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
+					TEGRA_UART_IER_EORD);
+	tup->ier_shadow = ier;
+	tegra_uart_write(tup, ier, UART_IER);
+	tup->rx_in_progress = 0;
+
+	if (!tup->use_rx_pio)
+		tegra_uart_terminate_rx_dma(tup);
+	else
+		tegra_uart_handle_rx_pio(tup, port);
+}
+
+static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
+{
+	unsigned long flags;
+	unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud);
+	unsigned long fifo_empty_time = tup->uport.fifosize * char_time;
+	unsigned long wait_time;
+	unsigned long lsr;
+	unsigned long msr;
+	unsigned long mcr;
+
+	/* Disable interrupts */
+	tegra_uart_write(tup, 0, UART_IER);
+
+	lsr = tegra_uart_read(tup, UART_LSR);
+	if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
+		msr = tegra_uart_read(tup, UART_MSR);
+		mcr = tegra_uart_read(tup, UART_MCR);
+		if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS))
+			dev_err(tup->uport.dev,
+				"Tx Fifo not empty, CTS disabled, waiting\n");
+
+		/* Wait for Tx fifo to be empty */
+		while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
+			wait_time = min(fifo_empty_time, 100lu);
+			udelay(wait_time);
+			fifo_empty_time -= wait_time;
+			if (!fifo_empty_time) {
+				msr = tegra_uart_read(tup, UART_MSR);
+				mcr = tegra_uart_read(tup, UART_MCR);
+				if ((mcr & TEGRA_UART_MCR_CTS_EN) &&
+					(msr & UART_MSR_CTS))
+					dev_err(tup->uport.dev,
+						"Slave not ready\n");
+				break;
+			}
+			lsr = tegra_uart_read(tup, UART_LSR);
+		}
+	}
+
+	spin_lock_irqsave(&tup->uport.lock, flags);
+	/* Reset the Rx and Tx FIFOs */
+	tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
+	tup->current_baud = 0;
+	spin_unlock_irqrestore(&tup->uport.lock, flags);
+
+	tup->rx_in_progress = 0;
+	tup->tx_in_progress = 0;
+
+	if (!tup->use_rx_pio)
+		tegra_uart_dma_channel_free(tup, true);
+	if (!tup->use_tx_pio)
+		tegra_uart_dma_channel_free(tup, false);
+
+	clk_disable_unprepare(tup->uart_clk);
+}
+
+static int tegra_uart_hw_init(struct tegra_uart_port *tup)
+{
+	int ret;
+
+	tup->fcr_shadow = 0;
+	tup->mcr_shadow = 0;
+	tup->lcr_shadow = 0;
+	tup->ier_shadow = 0;
+	tup->current_baud = 0;
+
+	ret = clk_prepare_enable(tup->uart_clk);
+	if (ret) {
+		dev_err(tup->uport.dev, "could not enable clk\n");
+		return ret;
+	}
+
+	/* Reset the UART controller to clear all previous status.*/
+	reset_control_assert(tup->rst);
+	udelay(10);
+	reset_control_deassert(tup->rst);
+
+	tup->rx_in_progress = 0;
+	tup->tx_in_progress = 0;
+
+	/*
+	 * Set the trigger level
+	 *
+	 * For PIO mode:
+	 *
+	 * For receive, this will interrupt the CPU after that many number of
+	 * bytes are received, for the remaining bytes the receive timeout
+	 * interrupt is received. Rx high watermark is set to 4.
+	 *
+	 * For transmit, if the trasnmit interrupt is enabled, this will
+	 * interrupt the CPU when the number of entries in the FIFO reaches the
+	 * low watermark. Tx low watermark is set to 16 bytes.
+	 *
+	 * For DMA mode:
+	 *
+	 * Set the Tx trigger to 16. This should match the DMA burst size that
+	 * programmed in the DMA registers.
+	 */
+	tup->fcr_shadow = UART_FCR_ENABLE_FIFO;
+
+	if (tup->use_rx_pio) {
+		tup->fcr_shadow |= UART_FCR_R_TRIG_11;
+	} else {
+		if (tup->cdata->max_dma_burst_bytes == 8)
+			tup->fcr_shadow |= UART_FCR_R_TRIG_10;
+		else
+			tup->fcr_shadow |= UART_FCR_R_TRIG_01;
+	}
+
+	tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B;
+	tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
+
+	/* Dummy read to ensure the write is posted */
+	tegra_uart_read(tup, UART_SCR);
+
+	if (tup->cdata->fifo_mode_enable_status) {
+		ret = tegra_uart_wait_fifo_mode_enabled(tup);
+		if (ret < 0) {
+			clk_disable_unprepare(tup->uart_clk);
+			dev_err(tup->uport.dev,
+				"Failed to enable FIFO mode: %d\n", ret);
+			return ret;
+		}
+	} else {
+		/*
+		 * For all tegra devices (up to t210), there is a hardware
+		 * issue that requires software to wait for 3 UART clock
+		 * periods after enabling the TX fifo, otherwise data could
+		 * be lost.
+		 */
+		tegra_uart_wait_cycle_time(tup, 3);
+	}
+
+	/*
+	 * Initialize the UART with default configuration
+	 * (115200, N, 8, 1) so that the receive DMA buffer may be
+	 * enqueued
+	 */
+	ret = tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
+	if (ret < 0) {
+		clk_disable_unprepare(tup->uart_clk);
+		dev_err(tup->uport.dev, "Failed to set baud rate\n");
+		return ret;
+	}
+	if (!tup->use_rx_pio) {
+		tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR;
+		tup->fcr_shadow |= UART_FCR_DMA_SELECT;
+		tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
+	} else {
+		tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
+	}
+	tup->rx_in_progress = 1;
+
+	/*
+	 * Enable IE_RXS for the receive status interrupts like line errors.
+	 * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd.
+	 *
+	 * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when
+	 * the DATA is sitting in the FIFO and couldn't be transferred to the
+	 * DMA as the DMA size alignment (4 bytes) is not met. EORD will be
+	 * triggered when there is a pause of the incomming data stream for 4
+	 * characters long.
+	 *
+	 * For pauses in the data which is not aligned to 4 bytes, we get
+	 * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first
+	 * then the EORD.
+	 */
+	tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | UART_IER_RDI;
+
+	/*
+	 * If using DMA mode, enable EORD interrupt to notify about RX
+	 * completion.
+	 */
+	if (!tup->use_rx_pio)
+		tup->ier_shadow |= TEGRA_UART_IER_EORD;
+
+	tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+	return 0;
+}
+
+static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
+		bool dma_to_memory)
+{
+	if (dma_to_memory) {
+		dmaengine_terminate_all(tup->rx_dma_chan);
+		dma_release_channel(tup->rx_dma_chan);
+		dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE,
+				tup->rx_dma_buf_virt, tup->rx_dma_buf_phys);
+		tup->rx_dma_chan = NULL;
+		tup->rx_dma_buf_phys = 0;
+		tup->rx_dma_buf_virt = NULL;
+	} else {
+		dmaengine_terminate_all(tup->tx_dma_chan);
+		dma_release_channel(tup->tx_dma_chan);
+		dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys,
+			UART_XMIT_SIZE, DMA_TO_DEVICE);
+		tup->tx_dma_chan = NULL;
+		tup->tx_dma_buf_phys = 0;
+		tup->tx_dma_buf_virt = NULL;
+	}
+}
+
+static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
+			bool dma_to_memory)
+{
+	struct dma_chan *dma_chan;
+	unsigned char *dma_buf;
+	dma_addr_t dma_phys;
+	int ret;
+	struct dma_slave_config dma_sconfig;
+
+	dma_chan = dma_request_chan(tup->uport.dev, dma_to_memory ? "rx" : "tx");
+	if (IS_ERR(dma_chan)) {
+		ret = PTR_ERR(dma_chan);
+		dev_err(tup->uport.dev,
+			"DMA channel alloc failed: %d\n", ret);
+		return ret;
+	}
+
+	if (dma_to_memory) {
+		dma_buf = dma_alloc_coherent(tup->uport.dev,
+				TEGRA_UART_RX_DMA_BUFFER_SIZE,
+				 &dma_phys, GFP_KERNEL);
+		if (!dma_buf) {
+			dev_err(tup->uport.dev,
+				"Not able to allocate the dma buffer\n");
+			dma_release_channel(dma_chan);
+			return -ENOMEM;
+		}
+		dma_sync_single_for_device(tup->uport.dev, dma_phys,
+					   TEGRA_UART_RX_DMA_BUFFER_SIZE,
+					   DMA_TO_DEVICE);
+		dma_sconfig.src_addr = tup->uport.mapbase;
+		dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		dma_sconfig.src_maxburst = tup->cdata->max_dma_burst_bytes;
+		tup->rx_dma_chan = dma_chan;
+		tup->rx_dma_buf_virt = dma_buf;
+		tup->rx_dma_buf_phys = dma_phys;
+	} else {
+		dma_phys = dma_map_single(tup->uport.dev,
+			tup->uport.state->xmit.buf, UART_XMIT_SIZE,
+			DMA_TO_DEVICE);
+		if (dma_mapping_error(tup->uport.dev, dma_phys)) {
+			dev_err(tup->uport.dev, "dma_map_single tx failed\n");
+			dma_release_channel(dma_chan);
+			return -ENOMEM;
+		}
+		dma_buf = tup->uport.state->xmit.buf;
+		dma_sconfig.dst_addr = tup->uport.mapbase;
+		dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		dma_sconfig.dst_maxburst = 16;
+		tup->tx_dma_chan = dma_chan;
+		tup->tx_dma_buf_virt = dma_buf;
+		tup->tx_dma_buf_phys = dma_phys;
+	}
+
+	ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
+	if (ret < 0) {
+		dev_err(tup->uport.dev,
+			"Dma slave config failed, err = %d\n", ret);
+		tegra_uart_dma_channel_free(tup, dma_to_memory);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int tegra_uart_startup(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	int ret;
+
+	if (!tup->use_tx_pio) {
+		ret = tegra_uart_dma_channel_allocate(tup, false);
+		if (ret < 0) {
+			dev_err(u->dev, "Tx Dma allocation failed, err = %d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	if (!tup->use_rx_pio) {
+		ret = tegra_uart_dma_channel_allocate(tup, true);
+		if (ret < 0) {
+			dev_err(u->dev, "Rx Dma allocation failed, err = %d\n",
+				ret);
+			goto fail_rx_dma;
+		}
+	}
+
+	ret = tegra_uart_hw_init(tup);
+	if (ret < 0) {
+		dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
+		goto fail_hw_init;
+	}
+
+	ret = request_irq(u->irq, tegra_uart_isr, 0,
+				dev_name(u->dev), tup);
+	if (ret < 0) {
+		dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
+		goto fail_request_irq;
+	}
+	return 0;
+
+fail_request_irq:
+	/* tup->uart_clk is already enabled in tegra_uart_hw_init */
+	clk_disable_unprepare(tup->uart_clk);
+fail_hw_init:
+	if (!tup->use_rx_pio)
+		tegra_uart_dma_channel_free(tup, true);
+fail_rx_dma:
+	if (!tup->use_tx_pio)
+		tegra_uart_dma_channel_free(tup, false);
+	return ret;
+}
+
+/*
+ * Flush any TX data submitted for DMA and PIO. Called when the
+ * TX circular buffer is reset.
+ */
+static void tegra_uart_flush_buffer(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+
+	tup->tx_bytes = 0;
+	if (tup->tx_dma_chan)
+		dmaengine_terminate_all(tup->tx_dma_chan);
+}
+
+static void tegra_uart_shutdown(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+
+	tegra_uart_hw_deinit(tup);
+	free_irq(u->irq, tup);
+}
+
+static void tegra_uart_enable_ms(struct uart_port *u)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+
+	if (tup->enable_modem_interrupt) {
+		tup->ier_shadow |= UART_IER_MSI;
+		tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+	}
+}
+
+static void tegra_uart_set_termios(struct uart_port *u,
+				   struct ktermios *termios,
+				   const struct ktermios *oldtermios)
+{
+	struct tegra_uart_port *tup = to_tegra_uport(u);
+	unsigned int baud;
+	unsigned long flags;
+	unsigned int lcr;
+	unsigned char char_bits;
+	struct clk *parent_clk = clk_get_parent(tup->uart_clk);
+	unsigned long parent_clk_rate = clk_get_rate(parent_clk);
+	int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
+	int ret;
+
+	max_divider *= 16;
+	spin_lock_irqsave(&u->lock, flags);
+
+	/* Changing configuration, it is safe to stop any rx now */
+	if (tup->rts_active)
+		set_rts(tup, false);
+
+	/* Clear all interrupts as configuration is going to be changed */
+	tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
+	tegra_uart_read(tup, UART_IER);
+	tegra_uart_write(tup, 0, UART_IER);
+	tegra_uart_read(tup, UART_IER);
+
+	/* Parity */
+	lcr = tup->lcr_shadow;
+	lcr &= ~UART_LCR_PARITY;
+
+	/* CMSPAR isn't supported by this driver */
+	termios->c_cflag &= ~CMSPAR;
+
+	if ((termios->c_cflag & PARENB) == PARENB) {
+		if (termios->c_cflag & PARODD) {
+			lcr |= UART_LCR_PARITY;
+			lcr &= ~UART_LCR_EPAR;
+			lcr &= ~UART_LCR_SPAR;
+		} else {
+			lcr |= UART_LCR_PARITY;
+			lcr |= UART_LCR_EPAR;
+			lcr &= ~UART_LCR_SPAR;
+		}
+	}
+
+	char_bits = tty_get_char_size(termios->c_cflag);
+	lcr &= ~UART_LCR_WLEN8;
+	lcr |= UART_LCR_WLEN(char_bits);
+
+	/* Stop bits */
+	if (termios->c_cflag & CSTOPB)
+		lcr |= UART_LCR_STOP;
+	else
+		lcr &= ~UART_LCR_STOP;
+
+	tegra_uart_write(tup, lcr, UART_LCR);
+	tup->lcr_shadow = lcr;
+	tup->symb_bit = tty_get_frame_size(termios->c_cflag);
+
+	/* Baud rate. */
+	baud = uart_get_baud_rate(u, termios, oldtermios,
+			parent_clk_rate/max_divider,
+			parent_clk_rate/16);
+	spin_unlock_irqrestore(&u->lock, flags);
+	ret = tegra_set_baudrate(tup, baud);
+	if (ret < 0) {
+		dev_err(tup->uport.dev, "Failed to set baud rate\n");
+		return;
+	}
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+	spin_lock_irqsave(&u->lock, flags);
+
+	/* Flow control */
+	if (termios->c_cflag & CRTSCTS)	{
+		tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN;
+		tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
+		tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
+		/* if top layer has asked to set rts active then do so here */
+		if (tup->rts_active)
+			set_rts(tup, true);
+	} else {
+		tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN;
+		tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
+		tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
+	}
+
+	/* update the port timeout based on new settings */
+	uart_update_timeout(u, termios->c_cflag, baud);
+
+	/* Make sure all writes have completed */
+	tegra_uart_read(tup, UART_IER);
+
+	/* Re-enable interrupt */
+	tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+	tegra_uart_read(tup, UART_IER);
+
+	tup->uport.ignore_status_mask = 0;
+	/* Ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0)
+		tup->uport.ignore_status_mask |= UART_LSR_DR;
+	if (termios->c_iflag & IGNBRK)
+		tup->uport.ignore_status_mask |= UART_LSR_BI;
+
+	spin_unlock_irqrestore(&u->lock, flags);
+}
+
+static const char *tegra_uart_type(struct uart_port *u)
+{
+	return TEGRA_UART_TYPE;
+}
+
+static const struct uart_ops tegra_uart_ops = {
+	.tx_empty	= tegra_uart_tx_empty,
+	.set_mctrl	= tegra_uart_set_mctrl,
+	.get_mctrl	= tegra_uart_get_mctrl,
+	.stop_tx	= tegra_uart_stop_tx,
+	.start_tx	= tegra_uart_start_tx,
+	.stop_rx	= tegra_uart_stop_rx,
+	.flush_buffer	= tegra_uart_flush_buffer,
+	.enable_ms	= tegra_uart_enable_ms,
+	.break_ctl	= tegra_uart_break_ctl,
+	.startup	= tegra_uart_startup,
+	.shutdown	= tegra_uart_shutdown,
+	.set_termios	= tegra_uart_set_termios,
+	.type		= tegra_uart_type,
+	.request_port	= tegra_uart_request_port,
+	.release_port	= tegra_uart_release_port,
+};
+
+static struct uart_driver tegra_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "tegra_hsuart",
+	.dev_name	= "ttyTHS",
+	.cons		= NULL,
+	.nr		= TEGRA_UART_MAXIMUM,
+};
+
+static int tegra_uart_parse_dt(struct platform_device *pdev,
+	struct tegra_uart_port *tup)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int port;
+	int ret;
+	int index;
+	u32 pval;
+	int count;
+	int n_entries;
+
+	port = of_alias_get_id(np, "serial");
+	if (port < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
+		return port;
+	}
+	tup->uport.line = port;
+
+	tup->enable_modem_interrupt = of_property_read_bool(np,
+					"nvidia,enable-modem-interrupt");
+
+	index = of_property_match_string(np, "dma-names", "rx");
+	if (index < 0) {
+		tup->use_rx_pio = true;
+		dev_info(&pdev->dev, "RX in PIO mode\n");
+	}
+	index = of_property_match_string(np, "dma-names", "tx");
+	if (index < 0) {
+		tup->use_tx_pio = true;
+		dev_info(&pdev->dev, "TX in PIO mode\n");
+	}
+
+	n_entries = of_property_count_u32_elems(np, "nvidia,adjust-baud-rates");
+	if (n_entries > 0) {
+		tup->n_adjustable_baud_rates = n_entries / 3;
+		tup->baud_tolerance =
+		devm_kzalloc(&pdev->dev, (tup->n_adjustable_baud_rates) *
+			     sizeof(*tup->baud_tolerance), GFP_KERNEL);
+		if (!tup->baud_tolerance)
+			return -ENOMEM;
+		for (count = 0, index = 0; count < n_entries; count += 3,
+		     index++) {
+			ret =
+			of_property_read_u32_index(np,
+						   "nvidia,adjust-baud-rates",
+						   count, &pval);
+			if (!ret)
+				tup->baud_tolerance[index].lower_range_baud =
+				pval;
+			ret =
+			of_property_read_u32_index(np,
+						   "nvidia,adjust-baud-rates",
+						   count + 1, &pval);
+			if (!ret)
+				tup->baud_tolerance[index].upper_range_baud =
+				pval;
+			ret =
+			of_property_read_u32_index(np,
+						   "nvidia,adjust-baud-rates",
+						   count + 2, &pval);
+			if (!ret)
+				tup->baud_tolerance[index].tolerance =
+				(s32)pval;
+		}
+	} else {
+		tup->n_adjustable_baud_rates = 0;
+	}
+
+	return 0;
+}
+
+static struct tegra_uart_chip_data tegra20_uart_chip_data = {
+	.tx_fifo_full_status		= false,
+	.allow_txfifo_reset_fifo_mode	= true,
+	.support_clk_src_div		= false,
+	.fifo_mode_enable_status	= false,
+	.uart_max_port			= 5,
+	.max_dma_burst_bytes		= 4,
+	.error_tolerance_low_range	= -4,
+	.error_tolerance_high_range	= 4,
+};
+
+static struct tegra_uart_chip_data tegra30_uart_chip_data = {
+	.tx_fifo_full_status		= true,
+	.allow_txfifo_reset_fifo_mode	= false,
+	.support_clk_src_div		= true,
+	.fifo_mode_enable_status	= false,
+	.uart_max_port			= 5,
+	.max_dma_burst_bytes		= 4,
+	.error_tolerance_low_range	= -4,
+	.error_tolerance_high_range	= 4,
+};
+
+static struct tegra_uart_chip_data tegra186_uart_chip_data = {
+	.tx_fifo_full_status		= true,
+	.allow_txfifo_reset_fifo_mode	= false,
+	.support_clk_src_div		= true,
+	.fifo_mode_enable_status	= true,
+	.uart_max_port			= 8,
+	.max_dma_burst_bytes		= 8,
+	.error_tolerance_low_range	= 0,
+	.error_tolerance_high_range	= 4,
+};
+
+static struct tegra_uart_chip_data tegra194_uart_chip_data = {
+	.tx_fifo_full_status		= true,
+	.allow_txfifo_reset_fifo_mode	= false,
+	.support_clk_src_div		= true,
+	.fifo_mode_enable_status	= true,
+	.uart_max_port			= 8,
+	.max_dma_burst_bytes		= 8,
+	.error_tolerance_low_range	= -2,
+	.error_tolerance_high_range	= 2,
+};
+
+static const struct of_device_id tegra_uart_of_match[] = {
+	{
+		.compatible	= "nvidia,tegra30-hsuart",
+		.data		= &tegra30_uart_chip_data,
+	}, {
+		.compatible	= "nvidia,tegra20-hsuart",
+		.data		= &tegra20_uart_chip_data,
+	}, {
+		.compatible     = "nvidia,tegra186-hsuart",
+		.data		= &tegra186_uart_chip_data,
+	}, {
+		.compatible     = "nvidia,tegra194-hsuart",
+		.data		= &tegra194_uart_chip_data,
+	}, {
+	},
+};
+MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
+
+static int tegra_uart_probe(struct platform_device *pdev)
+{
+	struct tegra_uart_port *tup;
+	struct uart_port *u;
+	struct resource *resource;
+	int ret;
+	const struct tegra_uart_chip_data *cdata;
+
+	cdata = of_device_get_match_data(&pdev->dev);
+	if (!cdata) {
+		dev_err(&pdev->dev, "Error: No device match found\n");
+		return -ENODEV;
+	}
+
+	tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL);
+	if (!tup) {
+		dev_err(&pdev->dev, "Failed to allocate memory for tup\n");
+		return -ENOMEM;
+	}
+
+	ret = tegra_uart_parse_dt(pdev, tup);
+	if (ret < 0)
+		return ret;
+
+	u = &tup->uport;
+	u->dev = &pdev->dev;
+	u->ops = &tegra_uart_ops;
+	u->type = PORT_TEGRA;
+	u->fifosize = 32;
+	tup->cdata = cdata;
+
+	platform_set_drvdata(pdev, tup);
+
+	u->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &resource);
+	if (IS_ERR(u->membase))
+		return PTR_ERR(u->membase);
+	u->mapbase = resource->start;
+
+	tup->uart_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(tup->uart_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(tup->uart_clk), "Couldn't get the clock");
+
+	tup->rst = devm_reset_control_get_exclusive(&pdev->dev, "serial");
+	if (IS_ERR(tup->rst)) {
+		dev_err(&pdev->dev, "Couldn't get the reset\n");
+		return PTR_ERR(tup->rst);
+	}
+
+	u->iotype = UPIO_MEM32;
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	u->irq = ret;
+	u->regshift = 2;
+	ret = uart_add_one_port(&tegra_uart_driver, u);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
+		return ret;
+	}
+	return ret;
+}
+
+static int tegra_uart_remove(struct platform_device *pdev)
+{
+	struct tegra_uart_port *tup = platform_get_drvdata(pdev);
+	struct uart_port *u = &tup->uport;
+
+	uart_remove_one_port(&tegra_uart_driver, u);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_uart_suspend(struct device *dev)
+{
+	struct tegra_uart_port *tup = dev_get_drvdata(dev);
+	struct uart_port *u = &tup->uport;
+
+	return uart_suspend_port(&tegra_uart_driver, u);
+}
+
+static int tegra_uart_resume(struct device *dev)
+{
+	struct tegra_uart_port *tup = dev_get_drvdata(dev);
+	struct uart_port *u = &tup->uport;
+
+	return uart_resume_port(&tegra_uart_driver, u);
+}
+#endif
+
+static const struct dev_pm_ops tegra_uart_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume)
+};
+
+static struct platform_driver tegra_uart_platform_driver = {
+	.probe		= tegra_uart_probe,
+	.remove		= tegra_uart_remove,
+	.driver		= {
+		.name	= "serial-tegra",
+		.of_match_table = tegra_uart_of_match,
+		.pm	= &tegra_uart_pm_ops,
+	},
+};
+
+static int __init tegra_uart_init(void)
+{
+	int ret;
+	struct device_node *node;
+	const struct of_device_id *match = NULL;
+	const struct tegra_uart_chip_data *cdata = NULL;
+
+	node = of_find_matching_node(NULL, tegra_uart_of_match);
+	if (node)
+		match = of_match_node(tegra_uart_of_match, node);
+	of_node_put(node);
+	if (match)
+		cdata = match->data;
+	if (cdata)
+		tegra_uart_driver.nr = cdata->uart_max_port;
+
+	ret = uart_register_driver(&tegra_uart_driver);
+	if (ret < 0) {
+		pr_err("Could not register %s driver\n",
+		       tegra_uart_driver.driver_name);
+		return ret;
+	}
+
+	ret = platform_driver_register(&tegra_uart_platform_driver);
+	if (ret < 0) {
+		pr_err("Uart platform driver register failed, e = %d\n", ret);
+		uart_unregister_driver(&tegra_uart_driver);
+		return ret;
+	}
+	return 0;
+}
+
+static void __exit tegra_uart_exit(void)
+{
+	pr_info("Unloading tegra uart driver\n");
+	platform_driver_unregister(&tegra_uart_platform_driver);
+	uart_unregister_driver(&tegra_uart_driver);
+}
+
+module_init(tegra_uart_init);
+module_exit(tegra_uart_exit);
+
+MODULE_ALIAS("platform:serial-tegra");
+MODULE_DESCRIPTION("High speed UART driver for tegra chipset");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/serial_base.h b/drivers/tty/serial/serial_base.h
new file mode 100644
index 000000000..c74c548f0
--- /dev/null
+++ b/drivers/tty/serial/serial_base.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Serial core related functions, serial port device drivers do not need this.
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ */
+
+#define to_serial_base_ctrl_device(d) container_of((d), struct serial_ctrl_device, dev)
+#define to_serial_base_port_device(d) container_of((d), struct serial_port_device, dev)
+
+struct uart_driver;
+struct uart_port;
+struct device_driver;
+struct device;
+
+struct serial_ctrl_device {
+	struct device dev;
+	struct ida port_ida;
+};
+
+struct serial_port_device {
+	struct device dev;
+	struct uart_port *port;
+};
+
+int serial_base_ctrl_init(void);
+void serial_base_ctrl_exit(void);
+
+int serial_base_port_init(void);
+void serial_base_port_exit(void);
+
+int serial_base_driver_register(struct device_driver *driver);
+void serial_base_driver_unregister(struct device_driver *driver);
+
+struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
+						struct device *parent);
+struct serial_port_device *serial_base_port_add(struct uart_port *port,
+						struct serial_ctrl_device *parent);
+void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev);
+void serial_base_port_device_remove(struct serial_port_device *port_dev);
+
+int serial_ctrl_register_port(struct uart_driver *drv, struct uart_port *port);
+void serial_ctrl_unregister_port(struct uart_driver *drv, struct uart_port *port);
+
+int serial_core_register_port(struct uart_driver *drv, struct uart_port *port);
+void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port);
diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
new file mode 100644
index 000000000..3dfcf20c4
--- /dev/null
+++ b/drivers/tty/serial/serial_base_bus.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial base bus layer for controllers
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ *
+ * The serial core bus manages the serial core controller instances.
+ */
+
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+static bool serial_base_initialized;
+
+static const struct device_type serial_ctrl_type = {
+	.name = "ctrl",
+};
+
+static const struct device_type serial_port_type = {
+	.name = "port",
+};
+
+static int serial_base_match(struct device *dev, struct device_driver *drv)
+{
+	if (dev->type == &serial_ctrl_type &&
+	    str_has_prefix(drv->name, serial_ctrl_type.name))
+		return 1;
+
+	if (dev->type == &serial_port_type &&
+	    str_has_prefix(drv->name, serial_port_type.name))
+		return 1;
+
+	return 0;
+}
+
+static struct bus_type serial_base_bus_type = {
+	.name = "serial-base",
+	.match = serial_base_match,
+};
+
+int serial_base_driver_register(struct device_driver *driver)
+{
+	driver->bus = &serial_base_bus_type;
+
+	return driver_register(driver);
+}
+
+void serial_base_driver_unregister(struct device_driver *driver)
+{
+	driver_unregister(driver);
+}
+
+static int serial_base_device_init(struct uart_port *port,
+				   struct device *dev,
+				   struct device *parent_dev,
+				   const struct device_type *type,
+				   void (*release)(struct device *dev),
+				   unsigned int ctrl_id,
+				   unsigned int port_id)
+{
+	device_initialize(dev);
+	dev->type = type;
+	dev->parent = parent_dev;
+	dev->bus = &serial_base_bus_type;
+	dev->release = release;
+
+	if (!serial_base_initialized) {
+		dev_dbg(port->dev, "uart_add_one_port() called before arch_initcall()?\n");
+		return -EPROBE_DEFER;
+	}
+
+	if (type == &serial_ctrl_type)
+		return dev_set_name(dev, "%s:%d", dev_name(port->dev), ctrl_id);
+
+	if (type == &serial_port_type)
+		return dev_set_name(dev, "%s:%d.%d", dev_name(port->dev),
+				    ctrl_id, port_id);
+
+	return -EINVAL;
+}
+
+static void serial_base_ctrl_release(struct device *dev)
+{
+	struct serial_ctrl_device *ctrl_dev = to_serial_base_ctrl_device(dev);
+
+	kfree(ctrl_dev);
+}
+
+void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev)
+{
+	if (!ctrl_dev)
+		return;
+
+	device_del(&ctrl_dev->dev);
+	put_device(&ctrl_dev->dev);
+}
+
+struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
+						struct device *parent)
+{
+	struct serial_ctrl_device *ctrl_dev;
+	int err;
+
+	ctrl_dev = kzalloc(sizeof(*ctrl_dev), GFP_KERNEL);
+	if (!ctrl_dev)
+		return ERR_PTR(-ENOMEM);
+
+	ida_init(&ctrl_dev->port_ida);
+
+	err = serial_base_device_init(port, &ctrl_dev->dev,
+				      parent, &serial_ctrl_type,
+				      serial_base_ctrl_release,
+				      port->ctrl_id, 0);
+	if (err)
+		goto err_put_device;
+
+	err = device_add(&ctrl_dev->dev);
+	if (err)
+		goto err_put_device;
+
+	return ctrl_dev;
+
+err_put_device:
+	put_device(&ctrl_dev->dev);
+
+	return ERR_PTR(err);
+}
+
+static void serial_base_port_release(struct device *dev)
+{
+	struct serial_port_device *port_dev = to_serial_base_port_device(dev);
+
+	kfree(port_dev);
+}
+
+struct serial_port_device *serial_base_port_add(struct uart_port *port,
+						struct serial_ctrl_device *ctrl_dev)
+{
+	struct serial_port_device *port_dev;
+	int min = 0, max = -1;	/* Use -1 for max to apply IDA defaults */
+	int err;
+
+	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
+	if (!port_dev)
+		return ERR_PTR(-ENOMEM);
+
+	/* Device driver specified port_id vs automatic assignment? */
+	if (port->port_id) {
+		min = port->port_id;
+		max = port->port_id;
+	}
+
+	err = ida_alloc_range(&ctrl_dev->port_ida, min, max, GFP_KERNEL);
+	if (err < 0) {
+		kfree(port_dev);
+		return ERR_PTR(err);
+	}
+
+	port->port_id = err;
+
+	err = serial_base_device_init(port, &port_dev->dev,
+				      &ctrl_dev->dev, &serial_port_type,
+				      serial_base_port_release,
+				      port->ctrl_id, port->port_id);
+	if (err)
+		goto err_put_device;
+
+	port_dev->port = port;
+
+	err = device_add(&port_dev->dev);
+	if (err)
+		goto err_put_device;
+
+	return port_dev;
+
+err_put_device:
+	put_device(&port_dev->dev);
+	ida_free(&ctrl_dev->port_ida, port->port_id);
+
+	return ERR_PTR(err);
+}
+
+void serial_base_port_device_remove(struct serial_port_device *port_dev)
+{
+	struct serial_ctrl_device *ctrl_dev;
+	struct device *parent;
+
+	if (!port_dev)
+		return;
+
+	parent = port_dev->dev.parent;
+	ctrl_dev = to_serial_base_ctrl_device(parent);
+
+	device_del(&port_dev->dev);
+	ida_free(&ctrl_dev->port_ida, port_dev->port->port_id);
+	put_device(&port_dev->dev);
+}
+
+static int serial_base_init(void)
+{
+	int ret;
+
+	ret = bus_register(&serial_base_bus_type);
+	if (ret)
+		return ret;
+
+	ret = serial_base_ctrl_init();
+	if (ret)
+		goto err_bus_unregister;
+
+	ret = serial_base_port_init();
+	if (ret)
+		goto err_ctrl_exit;
+
+	serial_base_initialized = true;
+
+	return 0;
+
+err_ctrl_exit:
+	serial_base_ctrl_exit();
+
+err_bus_unregister:
+	bus_unregister(&serial_base_bus_type);
+
+	return ret;
+}
+arch_initcall(serial_base_init);
+
+static void serial_base_exit(void)
+{
+	serial_base_port_exit();
+	serial_base_ctrl_exit();
+	bus_unregister(&serial_base_bus_type);
+}
+module_exit(serial_base_exit);
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial core bus");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
new file mode 100644
index 000000000..083ea4de4
--- /dev/null
+++ b/drivers/tty/serial/serial_core.c
@@ -0,0 +1,3671 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver core for serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright 1999 ARM Limited
+ *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
+ */
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/device.h>
+#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
+#include <linux/serial_core.h>
+#include <linux/sysrq.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/math64.h>
+#include <linux/security.h>
+
+#include <linux/irq.h>
+#include <linux/uaccess.h>
+
+#include "serial_base.h"
+
+/*
+ * This is used to lock changes in serial line configuration.
+ */
+static DEFINE_MUTEX(port_mutex);
+
+/*
+ * lockdep: port->lock is initialized in two places, but we
+ *          want only one lock-class:
+ */
+static struct lock_class_key port_lock_key;
+
+#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
+
+/*
+ * Max time with active RTS before/after data is sent.
+ */
+#define RS485_MAX_RTS_DELAY	100 /* msecs */
+
+static void uart_change_pm(struct uart_state *state,
+			   enum uart_pm_state pm_state);
+
+static void uart_port_shutdown(struct tty_port *port);
+
+static int uart_dcd_enabled(struct uart_port *uport)
+{
+	return !!(uport->status & UPSTAT_DCD_ENABLE);
+}
+
+static inline struct uart_port *uart_port_ref(struct uart_state *state)
+{
+	if (atomic_add_unless(&state->refcount, 1, 0))
+		return state->uart_port;
+	return NULL;
+}
+
+static inline void uart_port_deref(struct uart_port *uport)
+{
+	if (atomic_dec_and_test(&uport->state->refcount))
+		wake_up(&uport->state->remove_wait);
+}
+
+#define uart_port_lock(state, flags)					\
+	({								\
+		struct uart_port *__uport = uart_port_ref(state);	\
+		if (__uport)						\
+			spin_lock_irqsave(&__uport->lock, flags);	\
+		__uport;						\
+	})
+
+#define uart_port_unlock(uport, flags)					\
+	({								\
+		struct uart_port *__uport = uport;			\
+		if (__uport) {						\
+			spin_unlock_irqrestore(&__uport->lock, flags);	\
+			uart_port_deref(__uport);			\
+		}							\
+	})
+
+static inline struct uart_port *uart_port_check(struct uart_state *state)
+{
+	lockdep_assert_held(&state->port.mutex);
+	return state->uart_port;
+}
+
+/**
+ * uart_write_wakeup - schedule write processing
+ * @port: port to be processed
+ *
+ * This routine is used by the interrupt handler to schedule processing in the
+ * software interrupt portion of the driver. A driver is expected to call this
+ * function when the number of characters in the transmit buffer have dropped
+ * below a threshold.
+ *
+ * Locking: @port->lock should be held
+ */
+void uart_write_wakeup(struct uart_port *port)
+{
+	struct uart_state *state = port->state;
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	BUG_ON(!state);
+	tty_port_tty_wakeup(&state->port);
+}
+EXPORT_SYMBOL(uart_write_wakeup);
+
+static void uart_stop(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+
+	port = uart_port_lock(state, flags);
+	if (port)
+		port->ops->stop_tx(port);
+	uart_port_unlock(port, flags);
+}
+
+static void __uart_start(struct uart_state *state)
+{
+	struct uart_port *port = state->uart_port;
+	struct serial_port_device *port_dev;
+	int err;
+
+	if (!port || port->flags & UPF_DEAD || uart_tx_stopped(port))
+		return;
+
+	port_dev = port->port_dev;
+
+	/* Increment the runtime PM usage count for the active check below */
+	err = pm_runtime_get(&port_dev->dev);
+	if (err < 0 && err != -EINPROGRESS) {
+		pm_runtime_put_noidle(&port_dev->dev);
+		return;
+	}
+
+	/*
+	 * Start TX if enabled, and kick runtime PM. If the device is not
+	 * enabled, serial_port_runtime_resume() calls start_tx() again
+	 * after enabling the device.
+	 */
+	if (!pm_runtime_enabled(port->dev) || pm_runtime_active(port->dev))
+		port->ops->start_tx(port);
+	pm_runtime_mark_last_busy(&port_dev->dev);
+	pm_runtime_put_autosuspend(&port_dev->dev);
+}
+
+static void uart_start(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+
+	port = uart_port_lock(state, flags);
+	__uart_start(state);
+	uart_port_unlock(port, flags);
+}
+
+static void
+uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
+{
+	unsigned long flags;
+	unsigned int old;
+
+	spin_lock_irqsave(&port->lock, flags);
+	old = port->mctrl;
+	port->mctrl = (old & ~clear) | set;
+	if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED))
+		port->ops->set_mctrl(port, port->mctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#define uart_set_mctrl(port, set)	uart_update_mctrl(port, set, 0)
+#define uart_clear_mctrl(port, clear)	uart_update_mctrl(port, 0, clear)
+
+static void uart_port_dtr_rts(struct uart_port *uport, bool active)
+{
+	if (active)
+		uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+	else
+		uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+}
+
+/* Caller holds port mutex */
+static void uart_change_line_settings(struct tty_struct *tty, struct uart_state *state,
+				      const struct ktermios *old_termios)
+{
+	struct uart_port *uport = uart_port_check(state);
+	struct ktermios *termios;
+	bool old_hw_stopped;
+
+	/*
+	 * If we have no tty, termios, or the port does not exist,
+	 * then we can't set the parameters for this port.
+	 */
+	if (!tty || uport->type == PORT_UNKNOWN)
+		return;
+
+	termios = &tty->termios;
+	uport->ops->set_termios(uport, termios, old_termios);
+
+	/*
+	 * Set modem status enables based on termios cflag
+	 */
+	spin_lock_irq(&uport->lock);
+	if (termios->c_cflag & CRTSCTS)
+		uport->status |= UPSTAT_CTS_ENABLE;
+	else
+		uport->status &= ~UPSTAT_CTS_ENABLE;
+
+	if (termios->c_cflag & CLOCAL)
+		uport->status &= ~UPSTAT_DCD_ENABLE;
+	else
+		uport->status |= UPSTAT_DCD_ENABLE;
+
+	/* reset sw-assisted CTS flow control based on (possibly) new mode */
+	old_hw_stopped = uport->hw_stopped;
+	uport->hw_stopped = uart_softcts_mode(uport) &&
+			    !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
+	if (uport->hw_stopped != old_hw_stopped) {
+		if (!old_hw_stopped)
+			uport->ops->stop_tx(uport);
+		else
+			__uart_start(state);
+	}
+	spin_unlock_irq(&uport->lock);
+}
+
+/*
+ * Startup the port.  This will be called once per open.  All calls
+ * will be serialised by the per-port mutex.
+ */
+static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
+			     bool init_hw)
+{
+	struct uart_port *uport = uart_port_check(state);
+	unsigned long flags;
+	unsigned long page;
+	int retval = 0;
+
+	if (uport->type == PORT_UNKNOWN)
+		return 1;
+
+	/*
+	 * Make sure the device is in D0 state.
+	 */
+	uart_change_pm(state, UART_PM_STATE_ON);
+
+	/*
+	 * Initialise and allocate the transmit and temporary
+	 * buffer.
+	 */
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	uart_port_lock(state, flags);
+	if (!state->xmit.buf) {
+		state->xmit.buf = (unsigned char *) page;
+		uart_circ_clear(&state->xmit);
+		uart_port_unlock(uport, flags);
+	} else {
+		uart_port_unlock(uport, flags);
+		/*
+		 * Do not free() the page under the port lock, see
+		 * uart_shutdown().
+		 */
+		free_page(page);
+	}
+
+	retval = uport->ops->startup(uport);
+	if (retval == 0) {
+		if (uart_console(uport) && uport->cons->cflag) {
+			tty->termios.c_cflag = uport->cons->cflag;
+			tty->termios.c_ispeed = uport->cons->ispeed;
+			tty->termios.c_ospeed = uport->cons->ospeed;
+			uport->cons->cflag = 0;
+			uport->cons->ispeed = 0;
+			uport->cons->ospeed = 0;
+		}
+		/*
+		 * Initialise the hardware port settings.
+		 */
+		uart_change_line_settings(tty, state, NULL);
+
+		/*
+		 * Setup the RTS and DTR signals once the
+		 * port is open and ready to respond.
+		 */
+		if (init_hw && C_BAUD(tty))
+			uart_port_dtr_rts(uport, true);
+	}
+
+	/*
+	 * This is to allow setserial on this port. People may want to set
+	 * port/irq/type and then reconfigure the port properly if it failed
+	 * now.
+	 */
+	if (retval && capable(CAP_SYS_ADMIN))
+		return 1;
+
+	return retval;
+}
+
+static int uart_startup(struct tty_struct *tty, struct uart_state *state,
+			bool init_hw)
+{
+	struct tty_port *port = &state->port;
+	int retval;
+
+	if (tty_port_initialized(port))
+		return 0;
+
+	retval = uart_port_startup(tty, state, init_hw);
+	if (retval)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+
+	return retval;
+}
+
+/*
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.  Calls to
+ * uart_shutdown are serialised by the per-port semaphore.
+ *
+ * uport == NULL if uart_port has already been removed
+ */
+static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
+{
+	struct uart_port *uport = uart_port_check(state);
+	struct tty_port *port = &state->port;
+	unsigned long flags;
+	char *xmit_buf = NULL;
+
+	/*
+	 * Set the TTY IO error marker
+	 */
+	if (tty)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+
+	if (tty_port_initialized(port)) {
+		tty_port_set_initialized(port, false);
+
+		/*
+		 * Turn off DTR and RTS early.
+		 */
+		if (uport && uart_console(uport) && tty) {
+			uport->cons->cflag = tty->termios.c_cflag;
+			uport->cons->ispeed = tty->termios.c_ispeed;
+			uport->cons->ospeed = tty->termios.c_ospeed;
+		}
+
+		if (!tty || C_HUPCL(tty))
+			uart_port_dtr_rts(uport, false);
+
+		uart_port_shutdown(port);
+	}
+
+	/*
+	 * It's possible for shutdown to be called after suspend if we get
+	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so
+	 * we don't try to resume a port that has been shutdown.
+	 */
+	tty_port_set_suspended(port, false);
+
+	/*
+	 * Do not free() the transmit buffer page under the port lock since
+	 * this can create various circular locking scenarios. For instance,
+	 * console driver may need to allocate/free a debug object, which
+	 * can endup in printk() recursion.
+	 */
+	uart_port_lock(state, flags);
+	xmit_buf = state->xmit.buf;
+	state->xmit.buf = NULL;
+	uart_port_unlock(uport, flags);
+
+	free_page((unsigned long)xmit_buf);
+}
+
+/**
+ * uart_update_timeout - update per-port frame timing information
+ * @port: uart_port structure describing the port
+ * @cflag: termios cflag value
+ * @baud: speed of the port
+ *
+ * Set the @port frame timing information from which the FIFO timeout value is
+ * derived. The @cflag value should reflect the actual hardware settings as
+ * number of bits, parity, stop bits and baud rate is taken into account here.
+ *
+ * Locking: caller is expected to take @port->lock
+ */
+void
+uart_update_timeout(struct uart_port *port, unsigned int cflag,
+		    unsigned int baud)
+{
+	unsigned int size = tty_get_frame_size(cflag);
+	u64 frame_time;
+
+	frame_time = (u64)size * NSEC_PER_SEC;
+	port->frame_time = DIV64_U64_ROUND_UP(frame_time, baud);
+}
+EXPORT_SYMBOL(uart_update_timeout);
+
+/**
+ * uart_get_baud_rate - return baud rate for a particular port
+ * @port: uart_port structure describing the port in question.
+ * @termios: desired termios settings
+ * @old: old termios (or %NULL)
+ * @min: minimum acceptable baud rate
+ * @max: maximum acceptable baud rate
+ *
+ * Decode the termios structure into a numeric baud rate, taking account of the
+ * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600
+ * baud.
+ *
+ * If the new baud rate is invalid, try the @old termios setting. If it's still
+ * invalid, we try 9600 baud.
+ *
+ * The @termios structure is updated to reflect the baud rate we're actually
+ * going to be using. Don't do this for the case where B0 is requested ("hang
+ * up").
+ *
+ * Locking: caller dependent
+ */
+unsigned int
+uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
+		   const struct ktermios *old, unsigned int min, unsigned int max)
+{
+	unsigned int try;
+	unsigned int baud;
+	unsigned int altbaud;
+	int hung_up = 0;
+	upf_t flags = port->flags & UPF_SPD_MASK;
+
+	switch (flags) {
+	case UPF_SPD_HI:
+		altbaud = 57600;
+		break;
+	case UPF_SPD_VHI:
+		altbaud = 115200;
+		break;
+	case UPF_SPD_SHI:
+		altbaud = 230400;
+		break;
+	case UPF_SPD_WARP:
+		altbaud = 460800;
+		break;
+	default:
+		altbaud = 38400;
+		break;
+	}
+
+	for (try = 0; try < 2; try++) {
+		baud = tty_termios_baud_rate(termios);
+
+		/*
+		 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
+		 * Die! Die! Die!
+		 */
+		if (try == 0 && baud == 38400)
+			baud = altbaud;
+
+		/*
+		 * Special case: B0 rate.
+		 */
+		if (baud == 0) {
+			hung_up = 1;
+			baud = 9600;
+		}
+
+		if (baud >= min && baud <= max)
+			return baud;
+
+		/*
+		 * Oops, the quotient was zero.  Try again with
+		 * the old baud rate if possible.
+		 */
+		termios->c_cflag &= ~CBAUD;
+		if (old) {
+			baud = tty_termios_baud_rate(old);
+			if (!hung_up)
+				tty_termios_encode_baud_rate(termios,
+								baud, baud);
+			old = NULL;
+			continue;
+		}
+
+		/*
+		 * As a last resort, if the range cannot be met then clip to
+		 * the nearest chip supported rate.
+		 */
+		if (!hung_up) {
+			if (baud <= min)
+				tty_termios_encode_baud_rate(termios,
+							min + 1, min + 1);
+			else
+				tty_termios_encode_baud_rate(termios,
+							max - 1, max - 1);
+		}
+	}
+	/* Should never happen */
+	WARN_ON(1);
+	return 0;
+}
+EXPORT_SYMBOL(uart_get_baud_rate);
+
+/**
+ * uart_get_divisor - return uart clock divisor
+ * @port: uart_port structure describing the port
+ * @baud: desired baud rate
+ *
+ * Calculate the divisor (baud_base / baud) for the specified @baud,
+ * appropriately rounded.
+ *
+ * If 38400 baud and custom divisor is selected, return the custom divisor
+ * instead.
+ *
+ * Locking: caller dependent
+ */
+unsigned int
+uart_get_divisor(struct uart_port *port, unsigned int baud)
+{
+	unsigned int quot;
+
+	/*
+	 * Old custom speed handling.
+	 */
+	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
+		quot = port->custom_divisor;
+	else
+		quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
+
+	return quot;
+}
+EXPORT_SYMBOL(uart_get_divisor);
+
+static int uart_put_char(struct tty_struct *tty, u8 c)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	struct circ_buf *circ;
+	unsigned long flags;
+	int ret = 0;
+
+	circ = &state->xmit;
+	port = uart_port_lock(state, flags);
+	if (!circ->buf) {
+		uart_port_unlock(port, flags);
+		return 0;
+	}
+
+	if (port && uart_circ_chars_free(circ) != 0) {
+		circ->buf[circ->head] = c;
+		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
+		ret = 1;
+	}
+	uart_port_unlock(port, flags);
+	return ret;
+}
+
+static void uart_flush_chars(struct tty_struct *tty)
+{
+	uart_start(tty);
+}
+
+static ssize_t uart_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	struct circ_buf *circ;
+	unsigned long flags;
+	int c, ret = 0;
+
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	if (WARN_ON(!state))
+		return -EL3HLT;
+
+	port = uart_port_lock(state, flags);
+	circ = &state->xmit;
+	if (!circ->buf) {
+		uart_port_unlock(port, flags);
+		return 0;
+	}
+
+	while (port) {
+		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
+		if (count < c)
+			c = count;
+		if (c <= 0)
+			break;
+		memcpy(circ->buf + circ->head, buf, c);
+		circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
+		buf += c;
+		count -= c;
+		ret += c;
+	}
+
+	__uart_start(state);
+	uart_port_unlock(port, flags);
+	return ret;
+}
+
+static unsigned int uart_write_room(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+	unsigned int ret;
+
+	port = uart_port_lock(state, flags);
+	ret = uart_circ_chars_free(&state->xmit);
+	uart_port_unlock(port, flags);
+	return ret;
+}
+
+static unsigned int uart_chars_in_buffer(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+	unsigned int ret;
+
+	port = uart_port_lock(state, flags);
+	ret = uart_circ_chars_pending(&state->xmit);
+	uart_port_unlock(port, flags);
+	return ret;
+}
+
+static void uart_flush_buffer(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	if (WARN_ON(!state))
+		return;
+
+	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
+
+	port = uart_port_lock(state, flags);
+	if (!port)
+		return;
+	uart_circ_clear(&state->xmit);
+	if (port->ops->flush_buffer)
+		port->ops->flush_buffer(port);
+	uart_port_unlock(port, flags);
+	tty_port_tty_wakeup(&state->port);
+}
+
+/*
+ * This function performs low-level write of high-priority XON/XOFF
+ * character and accounting for it.
+ *
+ * Requires uart_port to implement .serial_out().
+ */
+void uart_xchar_out(struct uart_port *uport, int offset)
+{
+	serial_port_out(uport, offset, uport->x_char);
+	uport->icount.tx++;
+	uport->x_char = 0;
+}
+EXPORT_SYMBOL_GPL(uart_xchar_out);
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ */
+static void uart_send_xchar(struct tty_struct *tty, char ch)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+
+	port = uart_port_ref(state);
+	if (!port)
+		return;
+
+	if (port->ops->send_xchar)
+		port->ops->send_xchar(port, ch);
+	else {
+		spin_lock_irqsave(&port->lock, flags);
+		port->x_char = ch;
+		if (ch)
+			port->ops->start_tx(port);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+	uart_port_deref(port);
+}
+
+static void uart_throttle(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	upstat_t mask = UPSTAT_SYNC_FIFO;
+	struct uart_port *port;
+
+	port = uart_port_ref(state);
+	if (!port)
+		return;
+
+	if (I_IXOFF(tty))
+		mask |= UPSTAT_AUTOXOFF;
+	if (C_CRTSCTS(tty))
+		mask |= UPSTAT_AUTORTS;
+
+	if (port->status & mask) {
+		port->ops->throttle(port);
+		mask &= ~port->status;
+	}
+
+	if (mask & UPSTAT_AUTORTS)
+		uart_clear_mctrl(port, TIOCM_RTS);
+
+	if (mask & UPSTAT_AUTOXOFF)
+		uart_send_xchar(tty, STOP_CHAR(tty));
+
+	uart_port_deref(port);
+}
+
+static void uart_unthrottle(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	upstat_t mask = UPSTAT_SYNC_FIFO;
+	struct uart_port *port;
+
+	port = uart_port_ref(state);
+	if (!port)
+		return;
+
+	if (I_IXOFF(tty))
+		mask |= UPSTAT_AUTOXOFF;
+	if (C_CRTSCTS(tty))
+		mask |= UPSTAT_AUTORTS;
+
+	if (port->status & mask) {
+		port->ops->unthrottle(port);
+		mask &= ~port->status;
+	}
+
+	if (mask & UPSTAT_AUTORTS)
+		uart_set_mctrl(port, TIOCM_RTS);
+
+	if (mask & UPSTAT_AUTOXOFF)
+		uart_send_xchar(tty, START_CHAR(tty));
+
+	uart_port_deref(port);
+}
+
+static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	int ret = -ENODEV;
+
+	/*
+	 * Ensure the state we copy is consistent and no hardware changes
+	 * occur as we go
+	 */
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (!uport)
+		goto out;
+
+	retinfo->type	    = uport->type;
+	retinfo->line	    = uport->line;
+	retinfo->port	    = uport->iobase;
+	if (HIGH_BITS_OFFSET)
+		retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
+	retinfo->irq		    = uport->irq;
+	retinfo->flags	    = (__force int)uport->flags;
+	retinfo->xmit_fifo_size  = uport->fifosize;
+	retinfo->baud_base	    = uport->uartclk / 16;
+	retinfo->close_delay	    = jiffies_to_msecs(port->close_delay) / 10;
+	retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+				ASYNC_CLOSING_WAIT_NONE :
+				jiffies_to_msecs(port->closing_wait) / 10;
+	retinfo->custom_divisor  = uport->custom_divisor;
+	retinfo->hub6	    = uport->hub6;
+	retinfo->io_type         = uport->iotype;
+	retinfo->iomem_reg_shift = uport->regshift;
+	retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
+
+	ret = 0;
+out:
+	mutex_unlock(&port->mutex);
+	return ret;
+}
+
+static int uart_get_info_user(struct tty_struct *tty,
+			 struct serial_struct *ss)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+
+	return uart_get_info(port, ss) < 0 ? -EIO : 0;
+}
+
+static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
+			 struct uart_state *state,
+			 struct serial_struct *new_info)
+{
+	struct uart_port *uport = uart_port_check(state);
+	unsigned long new_port;
+	unsigned int change_irq, change_port, closing_wait;
+	unsigned int old_custom_divisor, close_delay;
+	upf_t old_flags, new_flags;
+	int retval = 0;
+
+	if (!uport)
+		return -EIO;
+
+	new_port = new_info->port;
+	if (HIGH_BITS_OFFSET)
+		new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
+
+	new_info->irq = irq_canonicalize(new_info->irq);
+	close_delay = msecs_to_jiffies(new_info->close_delay * 10);
+	closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+			ASYNC_CLOSING_WAIT_NONE :
+			msecs_to_jiffies(new_info->closing_wait * 10);
+
+
+	change_irq  = !(uport->flags & UPF_FIXED_PORT)
+		&& new_info->irq != uport->irq;
+
+	/*
+	 * Since changing the 'type' of the port changes its resource
+	 * allocations, we should treat type changes the same as
+	 * IO port changes.
+	 */
+	change_port = !(uport->flags & UPF_FIXED_PORT)
+		&& (new_port != uport->iobase ||
+		    (unsigned long)new_info->iomem_base != uport->mapbase ||
+		    new_info->hub6 != uport->hub6 ||
+		    new_info->io_type != uport->iotype ||
+		    new_info->iomem_reg_shift != uport->regshift ||
+		    new_info->type != uport->type);
+
+	old_flags = uport->flags;
+	new_flags = (__force upf_t)new_info->flags;
+	old_custom_divisor = uport->custom_divisor;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		retval = -EPERM;
+		if (change_irq || change_port ||
+		    (new_info->baud_base != uport->uartclk / 16) ||
+		    (close_delay != port->close_delay) ||
+		    (closing_wait != port->closing_wait) ||
+		    (new_info->xmit_fifo_size &&
+		     new_info->xmit_fifo_size != uport->fifosize) ||
+		    (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
+			goto exit;
+		uport->flags = ((uport->flags & ~UPF_USR_MASK) |
+			       (new_flags & UPF_USR_MASK));
+		uport->custom_divisor = new_info->custom_divisor;
+		goto check_and_exit;
+	}
+
+	if (change_irq || change_port) {
+		retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
+		if (retval)
+			goto exit;
+	}
+
+	/*
+	 * Ask the low level driver to verify the settings.
+	 */
+	if (uport->ops->verify_port)
+		retval = uport->ops->verify_port(uport, new_info);
+
+	if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
+	    (new_info->baud_base < 9600))
+		retval = -EINVAL;
+
+	if (retval)
+		goto exit;
+
+	if (change_port || change_irq) {
+		retval = -EBUSY;
+
+		/*
+		 * Make sure that we are the sole user of this port.
+		 */
+		if (tty_port_users(port) > 1)
+			goto exit;
+
+		/*
+		 * We need to shutdown the serial port at the old
+		 * port/type/irq combination.
+		 */
+		uart_shutdown(tty, state);
+	}
+
+	if (change_port) {
+		unsigned long old_iobase, old_mapbase;
+		unsigned int old_type, old_iotype, old_hub6, old_shift;
+
+		old_iobase = uport->iobase;
+		old_mapbase = uport->mapbase;
+		old_type = uport->type;
+		old_hub6 = uport->hub6;
+		old_iotype = uport->iotype;
+		old_shift = uport->regshift;
+
+		/*
+		 * Free and release old regions
+		 */
+		if (old_type != PORT_UNKNOWN && uport->ops->release_port)
+			uport->ops->release_port(uport);
+
+		uport->iobase = new_port;
+		uport->type = new_info->type;
+		uport->hub6 = new_info->hub6;
+		uport->iotype = new_info->io_type;
+		uport->regshift = new_info->iomem_reg_shift;
+		uport->mapbase = (unsigned long)new_info->iomem_base;
+
+		/*
+		 * Claim and map the new regions
+		 */
+		if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
+			retval = uport->ops->request_port(uport);
+		} else {
+			/* Always success - Jean II */
+			retval = 0;
+		}
+
+		/*
+		 * If we fail to request resources for the
+		 * new port, try to restore the old settings.
+		 */
+		if (retval) {
+			uport->iobase = old_iobase;
+			uport->type = old_type;
+			uport->hub6 = old_hub6;
+			uport->iotype = old_iotype;
+			uport->regshift = old_shift;
+			uport->mapbase = old_mapbase;
+
+			if (old_type != PORT_UNKNOWN) {
+				retval = uport->ops->request_port(uport);
+				/*
+				 * If we failed to restore the old settings,
+				 * we fail like this.
+				 */
+				if (retval)
+					uport->type = PORT_UNKNOWN;
+
+				/*
+				 * We failed anyway.
+				 */
+				retval = -EBUSY;
+			}
+
+			/* Added to return the correct error -Ram Gupta */
+			goto exit;
+		}
+	}
+
+	if (change_irq)
+		uport->irq      = new_info->irq;
+	if (!(uport->flags & UPF_FIXED_PORT))
+		uport->uartclk  = new_info->baud_base * 16;
+	uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
+				 (new_flags & UPF_CHANGE_MASK);
+	uport->custom_divisor   = new_info->custom_divisor;
+	port->close_delay     = close_delay;
+	port->closing_wait    = closing_wait;
+	if (new_info->xmit_fifo_size)
+		uport->fifosize = new_info->xmit_fifo_size;
+
+ check_and_exit:
+	retval = 0;
+	if (uport->type == PORT_UNKNOWN)
+		goto exit;
+	if (tty_port_initialized(port)) {
+		if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
+		    old_custom_divisor != uport->custom_divisor) {
+			/*
+			 * If they're setting up a custom divisor or speed,
+			 * instead of clearing it, then bitch about it.
+			 */
+			if (uport->flags & UPF_SPD_MASK) {
+				dev_notice_ratelimited(uport->dev,
+				       "%s sets custom speed on %s. This is deprecated.\n",
+				      current->comm,
+				      tty_name(port->tty));
+			}
+			uart_change_line_settings(tty, state, NULL);
+		}
+	} else {
+		retval = uart_startup(tty, state, true);
+		if (retval == 0)
+			tty_port_set_initialized(port, true);
+		if (retval > 0)
+			retval = 0;
+	}
+ exit:
+	return retval;
+}
+
+static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	int retval;
+
+	down_write(&tty->termios_rwsem);
+	/*
+	 * This semaphore protects port->count.  It is also
+	 * very useful to prevent opens.  Also, take the
+	 * port configuration semaphore to make sure that a
+	 * module insertion/removal doesn't change anything
+	 * under us.
+	 */
+	mutex_lock(&port->mutex);
+	retval = uart_set_info(tty, port, state, ss);
+	mutex_unlock(&port->mutex);
+	up_write(&tty->termios_rwsem);
+	return retval;
+}
+
+/**
+ * uart_get_lsr_info - get line status register info
+ * @tty: tty associated with the UART
+ * @state: UART being queried
+ * @value: returned modem value
+ */
+static int uart_get_lsr_info(struct tty_struct *tty,
+			struct uart_state *state, unsigned int __user *value)
+{
+	struct uart_port *uport = uart_port_check(state);
+	unsigned int result;
+
+	result = uport->ops->tx_empty(uport);
+
+	/*
+	 * If we're about to load something into the transmit
+	 * register, we'll pretend the transmitter isn't empty to
+	 * avoid a race condition (depending on when the transmit
+	 * interrupt happens).
+	 */
+	if (uport->x_char ||
+	    ((uart_circ_chars_pending(&state->xmit) > 0) &&
+	     !uart_tx_stopped(uport)))
+		result &= ~TIOCSER_TEMT;
+
+	return put_user(result, value);
+}
+
+static int uart_tiocmget(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	struct uart_port *uport;
+	int result = -EIO;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (!uport)
+		goto out;
+
+	if (!tty_io_error(tty)) {
+		result = uport->mctrl;
+		spin_lock_irq(&uport->lock);
+		result |= uport->ops->get_mctrl(uport);
+		spin_unlock_irq(&uport->lock);
+	}
+out:
+	mutex_unlock(&port->mutex);
+	return result;
+}
+
+static int
+uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	struct uart_port *uport;
+	int ret = -EIO;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (!uport)
+		goto out;
+
+	if (!tty_io_error(tty)) {
+		uart_update_mctrl(uport, set, clear);
+		ret = 0;
+	}
+out:
+	mutex_unlock(&port->mutex);
+	return ret;
+}
+
+static int uart_break_ctl(struct tty_struct *tty, int break_state)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	struct uart_port *uport;
+	int ret = -EIO;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (!uport)
+		goto out;
+
+	if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl)
+		uport->ops->break_ctl(uport, break_state);
+	ret = 0;
+out:
+	mutex_unlock(&port->mutex);
+	return ret;
+}
+
+static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
+{
+	struct tty_port *port = &state->port;
+	struct uart_port *uport;
+	int flags, ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/*
+	 * Take the per-port semaphore.  This prevents count from
+	 * changing, and hence any extra opens of the port while
+	 * we're auto-configuring.
+	 */
+	if (mutex_lock_interruptible(&port->mutex))
+		return -ERESTARTSYS;
+
+	uport = uart_port_check(state);
+	if (!uport) {
+		ret = -EIO;
+		goto out;
+	}
+
+	ret = -EBUSY;
+	if (tty_port_users(port) == 1) {
+		uart_shutdown(tty, state);
+
+		/*
+		 * If we already have a port type configured,
+		 * we must release its resources.
+		 */
+		if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
+			uport->ops->release_port(uport);
+
+		flags = UART_CONFIG_TYPE;
+		if (uport->flags & UPF_AUTO_IRQ)
+			flags |= UART_CONFIG_IRQ;
+
+		/*
+		 * This will claim the ports resources if
+		 * a port is found.
+		 */
+		uport->ops->config_port(uport, flags);
+
+		ret = uart_startup(tty, state, true);
+		if (ret == 0)
+			tty_port_set_initialized(port, true);
+		if (ret > 0)
+			ret = 0;
+	}
+out:
+	mutex_unlock(&port->mutex);
+	return ret;
+}
+
+static void uart_enable_ms(struct uart_port *uport)
+{
+	/*
+	 * Force modem status interrupts on
+	 */
+	if (uport->ops->enable_ms)
+		uport->ops->enable_ms(uport);
+}
+
+/*
+ * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
+ * - mask passed in arg for lines of interest
+ *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
+ * Caller should use TIOCGICOUNT to see which one it was
+ *
+ * FIXME: This wants extracting into a common all driver implementation
+ * of TIOCMWAIT using tty_port.
+ */
+static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
+{
+	struct uart_port *uport;
+	struct tty_port *port = &state->port;
+	DECLARE_WAITQUEUE(wait, current);
+	struct uart_icount cprev, cnow;
+	int ret;
+
+	/*
+	 * note the counters on entry
+	 */
+	uport = uart_port_ref(state);
+	if (!uport)
+		return -EIO;
+	spin_lock_irq(&uport->lock);
+	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
+	uart_enable_ms(uport);
+	spin_unlock_irq(&uport->lock);
+
+	add_wait_queue(&port->delta_msr_wait, &wait);
+	for (;;) {
+		spin_lock_irq(&uport->lock);
+		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
+		spin_unlock_irq(&uport->lock);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+		    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+		    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
+		    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
+			ret = 0;
+			break;
+		}
+
+		schedule();
+
+		/* see if a signal did it */
+		if (signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+
+		cprev = cnow;
+	}
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&port->delta_msr_wait, &wait);
+	uart_port_deref(uport);
+
+	return ret;
+}
+
+/*
+ * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
+ * Return: write counters to the user passed counter struct
+ * NB: both 1->0 and 0->1 transitions are counted except for
+ *     RI where only 0->1 is counted.
+ */
+static int uart_get_icount(struct tty_struct *tty,
+			  struct serial_icounter_struct *icount)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_icount cnow;
+	struct uart_port *uport;
+
+	uport = uart_port_ref(state);
+	if (!uport)
+		return -EIO;
+	spin_lock_irq(&uport->lock);
+	memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
+	spin_unlock_irq(&uport->lock);
+	uart_port_deref(uport);
+
+	icount->cts         = cnow.cts;
+	icount->dsr         = cnow.dsr;
+	icount->rng         = cnow.rng;
+	icount->dcd         = cnow.dcd;
+	icount->rx          = cnow.rx;
+	icount->tx          = cnow.tx;
+	icount->frame       = cnow.frame;
+	icount->overrun     = cnow.overrun;
+	icount->parity      = cnow.parity;
+	icount->brk         = cnow.brk;
+	icount->buf_overrun = cnow.buf_overrun;
+
+	return 0;
+}
+
+#define SER_RS485_LEGACY_FLAGS	(SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \
+				 SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \
+				 SER_RS485_TERMINATE_BUS)
+
+static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485)
+{
+	u32 flags = rs485->flags;
+
+	/* Don't return -EINVAL for unsupported legacy flags */
+	flags &= ~SER_RS485_LEGACY_FLAGS;
+
+	/*
+	 * For any bit outside of the legacy ones that is not supported by
+	 * the driver, return -EINVAL.
+	 */
+	if (flags & ~port->rs485_supported.flags)
+		return -EINVAL;
+
+	/* Asking for address w/o addressing mode? */
+	if (!(rs485->flags & SER_RS485_ADDRB) &&
+	    (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST)))
+		return -EINVAL;
+
+	/* Address given but not enabled? */
+	if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv)
+		return -EINVAL;
+	if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void uart_sanitize_serial_rs485_delays(struct uart_port *port,
+					      struct serial_rs485 *rs485)
+{
+	if (!port->rs485_supported.delay_rts_before_send) {
+		if (rs485->delay_rts_before_send) {
+			dev_warn_ratelimited(port->dev,
+				"%s (%d): RTS delay before sending not supported\n",
+				port->name, port->line);
+		}
+		rs485->delay_rts_before_send = 0;
+	} else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) {
+		rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY;
+		dev_warn_ratelimited(port->dev,
+			"%s (%d): RTS delay before sending clamped to %u ms\n",
+			port->name, port->line, rs485->delay_rts_before_send);
+	}
+
+	if (!port->rs485_supported.delay_rts_after_send) {
+		if (rs485->delay_rts_after_send) {
+			dev_warn_ratelimited(port->dev,
+				"%s (%d): RTS delay after sending not supported\n",
+				port->name, port->line);
+		}
+		rs485->delay_rts_after_send = 0;
+	} else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) {
+		rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY;
+		dev_warn_ratelimited(port->dev,
+			"%s (%d): RTS delay after sending clamped to %u ms\n",
+			port->name, port->line, rs485->delay_rts_after_send);
+	}
+}
+
+static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485)
+{
+	u32 supported_flags = port->rs485_supported.flags;
+
+	if (!(rs485->flags & SER_RS485_ENABLED)) {
+		memset(rs485, 0, sizeof(*rs485));
+		return;
+	}
+
+	rs485->flags &= supported_flags;
+
+	/* Pick sane settings if the user hasn't */
+	if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+	    !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
+		if (supported_flags & SER_RS485_RTS_ON_SEND) {
+			rs485->flags |= SER_RS485_RTS_ON_SEND;
+			rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
+
+			dev_warn_ratelimited(port->dev,
+				"%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n",
+				port->name, port->line);
+		} else {
+			rs485->flags |= SER_RS485_RTS_AFTER_SEND;
+			rs485->flags &= ~SER_RS485_RTS_ON_SEND;
+
+			dev_warn_ratelimited(port->dev,
+				"%s (%d): invalid RTS setting, using RTS_AFTER_SEND instead\n",
+				port->name, port->line);
+		}
+	}
+
+	uart_sanitize_serial_rs485_delays(port, rs485);
+
+	/* Return clean padding area to userspace */
+	memset(rs485->padding0, 0, sizeof(rs485->padding0));
+	memset(rs485->padding1, 0, sizeof(rs485->padding1));
+}
+
+static void uart_set_rs485_termination(struct uart_port *port,
+				       const struct serial_rs485 *rs485)
+{
+	if (!(rs485->flags & SER_RS485_ENABLED))
+		return;
+
+	gpiod_set_value_cansleep(port->rs485_term_gpio,
+				 !!(rs485->flags & SER_RS485_TERMINATE_BUS));
+}
+
+static void uart_set_rs485_rx_during_tx(struct uart_port *port,
+					const struct serial_rs485 *rs485)
+{
+	if (!(rs485->flags & SER_RS485_ENABLED))
+		return;
+
+	gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
+				 !!(rs485->flags & SER_RS485_RX_DURING_TX));
+}
+
+static int uart_rs485_config(struct uart_port *port)
+{
+	struct serial_rs485 *rs485 = &port->rs485;
+	unsigned long flags;
+	int ret;
+
+	if (!(rs485->flags & SER_RS485_ENABLED))
+		return 0;
+
+	uart_sanitize_serial_rs485(port, rs485);
+	uart_set_rs485_termination(port, rs485);
+	uart_set_rs485_rx_during_tx(port, rs485);
+
+	spin_lock_irqsave(&port->lock, flags);
+	ret = port->rs485_config(port, NULL, rs485);
+	spin_unlock_irqrestore(&port->lock, flags);
+	if (ret) {
+		memset(rs485, 0, sizeof(*rs485));
+		/* unset GPIOs */
+		gpiod_set_value_cansleep(port->rs485_term_gpio, 0);
+		gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0);
+	}
+
+	return ret;
+}
+
+static int uart_get_rs485_config(struct uart_port *port,
+			 struct serial_rs485 __user *rs485)
+{
+	unsigned long flags;
+	struct serial_rs485 aux;
+
+	spin_lock_irqsave(&port->lock, flags);
+	aux = port->rs485;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (copy_to_user(rs485, &aux, sizeof(aux)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
+			 struct serial_rs485 __user *rs485_user)
+{
+	struct serial_rs485 rs485;
+	int ret;
+	unsigned long flags;
+
+	if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
+		return -ENOTTY;
+
+	if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
+		return -EFAULT;
+
+	ret = uart_check_rs485_flags(port, &rs485);
+	if (ret)
+		return ret;
+	uart_sanitize_serial_rs485(port, &rs485);
+	uart_set_rs485_termination(port, &rs485);
+	uart_set_rs485_rx_during_tx(port, &rs485);
+
+	spin_lock_irqsave(&port->lock, flags);
+	ret = port->rs485_config(port, &tty->termios, &rs485);
+	if (!ret) {
+		port->rs485 = rs485;
+
+		/* Reset RTS and other mctrl lines when disabling RS485 */
+		if (!(rs485.flags & SER_RS485_ENABLED))
+			port->ops->set_mctrl(port, port->mctrl);
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+	if (ret) {
+		/* restore old GPIO settings */
+		gpiod_set_value_cansleep(port->rs485_term_gpio,
+			!!(port->rs485.flags & SER_RS485_TERMINATE_BUS));
+		gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
+			!!(port->rs485.flags & SER_RS485_RX_DURING_TX));
+		return ret;
+	}
+
+	if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uart_get_iso7816_config(struct uart_port *port,
+				   struct serial_iso7816 __user *iso7816)
+{
+	unsigned long flags;
+	struct serial_iso7816 aux;
+
+	if (!port->iso7816_config)
+		return -ENOTTY;
+
+	spin_lock_irqsave(&port->lock, flags);
+	aux = port->iso7816;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (copy_to_user(iso7816, &aux, sizeof(aux)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uart_set_iso7816_config(struct uart_port *port,
+				   struct serial_iso7816 __user *iso7816_user)
+{
+	struct serial_iso7816 iso7816;
+	int i, ret;
+	unsigned long flags;
+
+	if (!port->iso7816_config)
+		return -ENOTTY;
+
+	if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
+		return -EFAULT;
+
+	/*
+	 * There are 5 words reserved for future use. Check that userspace
+	 * doesn't put stuff in there to prevent breakages in the future.
+	 */
+	for (i = 0; i < ARRAY_SIZE(iso7816.reserved); i++)
+		if (iso7816.reserved[i])
+			return -EINVAL;
+
+	spin_lock_irqsave(&port->lock, flags);
+	ret = port->iso7816_config(port, &iso7816);
+	spin_unlock_irqrestore(&port->lock, flags);
+	if (ret)
+		return ret;
+
+	if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * Called via sys_ioctl.  We can use spin_lock_irq() here.
+ */
+static int
+uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	struct uart_port *uport;
+	void __user *uarg = (void __user *)arg;
+	int ret = -ENOIOCTLCMD;
+
+
+	/*
+	 * These ioctls don't rely on the hardware to be present.
+	 */
+	switch (cmd) {
+	case TIOCSERCONFIG:
+		down_write(&tty->termios_rwsem);
+		ret = uart_do_autoconfig(tty, state);
+		up_write(&tty->termios_rwsem);
+		break;
+	}
+
+	if (ret != -ENOIOCTLCMD)
+		goto out;
+
+	if (tty_io_error(tty)) {
+		ret = -EIO;
+		goto out;
+	}
+
+	/*
+	 * The following should only be used when hardware is present.
+	 */
+	switch (cmd) {
+	case TIOCMIWAIT:
+		ret = uart_wait_modem_status(state, arg);
+		break;
+	}
+
+	if (ret != -ENOIOCTLCMD)
+		goto out;
+
+	/* rs485_config requires more locking than others */
+	if (cmd == TIOCSRS485)
+		down_write(&tty->termios_rwsem);
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+
+	if (!uport || tty_io_error(tty)) {
+		ret = -EIO;
+		goto out_up;
+	}
+
+	/*
+	 * All these rely on hardware being present and need to be
+	 * protected against the tty being hung up.
+	 */
+
+	switch (cmd) {
+	case TIOCSERGETLSR: /* Get line status register */
+		ret = uart_get_lsr_info(tty, state, uarg);
+		break;
+
+	case TIOCGRS485:
+		ret = uart_get_rs485_config(uport, uarg);
+		break;
+
+	case TIOCSRS485:
+		ret = uart_set_rs485_config(tty, uport, uarg);
+		break;
+
+	case TIOCSISO7816:
+		ret = uart_set_iso7816_config(state->uart_port, uarg);
+		break;
+
+	case TIOCGISO7816:
+		ret = uart_get_iso7816_config(state->uart_port, uarg);
+		break;
+	default:
+		if (uport->ops->ioctl)
+			ret = uport->ops->ioctl(uport, cmd, arg);
+		break;
+	}
+out_up:
+	mutex_unlock(&port->mutex);
+	if (cmd == TIOCSRS485)
+		up_write(&tty->termios_rwsem);
+out:
+	return ret;
+}
+
+static void uart_set_ldisc(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *uport;
+	struct tty_port *port = &state->port;
+
+	if (!tty_port_initialized(port))
+		return;
+
+	mutex_lock(&state->port.mutex);
+	uport = uart_port_check(state);
+	if (uport && uport->ops->set_ldisc)
+		uport->ops->set_ldisc(uport, &tty->termios);
+	mutex_unlock(&state->port.mutex);
+}
+
+static void uart_set_termios(struct tty_struct *tty,
+			     const struct ktermios *old_termios)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *uport;
+	unsigned int cflag = tty->termios.c_cflag;
+	unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
+	bool sw_changed = false;
+
+	mutex_lock(&state->port.mutex);
+	uport = uart_port_check(state);
+	if (!uport)
+		goto out;
+
+	/*
+	 * Drivers doing software flow control also need to know
+	 * about changes to these input settings.
+	 */
+	if (uport->flags & UPF_SOFT_FLOW) {
+		iflag_mask |= IXANY|IXON|IXOFF;
+		sw_changed =
+		   tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
+		   tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
+	}
+
+	/*
+	 * These are the bits that are used to setup various
+	 * flags in the low level driver. We can ignore the Bfoo
+	 * bits in c_cflag; c_[io]speed will always be set
+	 * appropriately by set_termios() in tty_ioctl.c
+	 */
+	if ((cflag ^ old_termios->c_cflag) == 0 &&
+	    tty->termios.c_ospeed == old_termios->c_ospeed &&
+	    tty->termios.c_ispeed == old_termios->c_ispeed &&
+	    ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
+	    !sw_changed) {
+		goto out;
+	}
+
+	uart_change_line_settings(tty, state, old_termios);
+	/* reload cflag from termios; port driver may have overridden flags */
+	cflag = tty->termios.c_cflag;
+
+	/* Handle transition to B0 status */
+	if (((old_termios->c_cflag & CBAUD) != B0) && ((cflag & CBAUD) == B0))
+		uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
+	/* Handle transition away from B0 status */
+	else if (((old_termios->c_cflag & CBAUD) == B0) && ((cflag & CBAUD) != B0)) {
+		unsigned int mask = TIOCM_DTR;
+
+		if (!(cflag & CRTSCTS) || !tty_throttled(tty))
+			mask |= TIOCM_RTS;
+		uart_set_mctrl(uport, mask);
+	}
+out:
+	mutex_unlock(&state->port.mutex);
+}
+
+/*
+ * Calls to uart_close() are serialised via the tty_lock in
+ *   drivers/tty/tty_io.c:tty_release()
+ *   drivers/tty/tty_io.c:do_tty_hangup()
+ */
+static void uart_close(struct tty_struct *tty, struct file *filp)
+{
+	struct uart_state *state = tty->driver_data;
+
+	if (!state) {
+		struct uart_driver *drv = tty->driver->driver_state;
+		struct tty_port *port;
+
+		state = drv->state + tty->index;
+		port = &state->port;
+		spin_lock_irq(&port->lock);
+		--port->count;
+		spin_unlock_irq(&port->lock);
+		return;
+	}
+
+	pr_debug("uart_close(%d) called\n", tty->index);
+
+	tty_port_close(tty->port, tty, filp);
+}
+
+static void uart_tty_port_shutdown(struct tty_port *port)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport = uart_port_check(state);
+	char *buf;
+
+	/*
+	 * At this point, we stop accepting input.  To do this, we
+	 * disable the receive line status interrupts.
+	 */
+	if (WARN(!uport, "detached port still initialized!\n"))
+		return;
+
+	spin_lock_irq(&uport->lock);
+	uport->ops->stop_rx(uport);
+	spin_unlock_irq(&uport->lock);
+
+	uart_port_shutdown(port);
+
+	/*
+	 * It's possible for shutdown to be called after suspend if we get
+	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so
+	 * we don't try to resume a port that has been shutdown.
+	 */
+	tty_port_set_suspended(port, false);
+
+	/*
+	 * Free the transmit buffer.
+	 */
+	spin_lock_irq(&uport->lock);
+	buf = state->xmit.buf;
+	state->xmit.buf = NULL;
+	spin_unlock_irq(&uport->lock);
+
+	free_page((unsigned long)buf);
+
+	uart_change_pm(state, UART_PM_STATE_OFF);
+}
+
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long char_time, expire, fifo_timeout;
+
+	port = uart_port_ref(state);
+	if (!port)
+		return;
+
+	if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
+		uart_port_deref(port);
+		return;
+	}
+
+	/*
+	 * Set the check interval to be 1/5 of the estimated time to
+	 * send a single character, and make it at least 1.  The check
+	 * interval should also be less than the timeout.
+	 *
+	 * Note: we have to use pretty tight timings here to satisfy
+	 * the NIST-PCTS.
+	 */
+	char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL);
+
+	if (timeout && timeout < char_time)
+		char_time = timeout;
+
+	if (!uart_cts_enabled(port)) {
+		/*
+		 * If the transmitter hasn't cleared in twice the approximate
+		 * amount of time to send the entire FIFO, it probably won't
+		 * ever clear.  This assumes the UART isn't doing flow
+		 * control, which is currently the case.  Hence, if it ever
+		 * takes longer than FIFO timeout, this is probably due to a
+		 * UART bug of some kind.  So, we clamp the timeout parameter at
+		 * 2 * FIFO timeout.
+		 */
+		fifo_timeout = uart_fifo_timeout(port);
+		if (timeout == 0 || timeout > 2 * fifo_timeout)
+			timeout = 2 * fifo_timeout;
+	}
+
+	expire = jiffies + timeout;
+
+	pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
+		port->line, jiffies, expire);
+
+	/*
+	 * Check whether the transmitter is empty every 'char_time'.
+	 * 'timeout' / 'expire' give us the maximum amount of time
+	 * we wait.
+	 */
+	while (!port->ops->tx_empty(port)) {
+		msleep_interruptible(jiffies_to_msecs(char_time));
+		if (signal_pending(current))
+			break;
+		if (timeout && time_after(jiffies, expire))
+			break;
+	}
+	uart_port_deref(port);
+}
+
+/*
+ * Calls to uart_hangup() are serialised by the tty_lock in
+ *   drivers/tty/tty_io.c:do_tty_hangup()
+ * This runs from a workqueue and can sleep for a _short_ time only.
+ */
+static void uart_hangup(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	struct uart_port *uport;
+	unsigned long flags;
+
+	pr_debug("uart_hangup(%d)\n", tty->index);
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	WARN(!uport, "hangup of detached port!\n");
+
+	if (tty_port_active(port)) {
+		uart_flush_buffer(tty);
+		uart_shutdown(tty, state);
+		spin_lock_irqsave(&port->lock, flags);
+		port->count = 0;
+		spin_unlock_irqrestore(&port->lock, flags);
+		tty_port_set_active(port, false);
+		tty_port_tty_set(port, NULL);
+		if (uport && !uart_console(uport))
+			uart_change_pm(state, UART_PM_STATE_OFF);
+		wake_up_interruptible(&port->open_wait);
+		wake_up_interruptible(&port->delta_msr_wait);
+	}
+	mutex_unlock(&port->mutex);
+}
+
+/* uport == NULL if uart_port has already been removed */
+static void uart_port_shutdown(struct tty_port *port)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport = uart_port_check(state);
+
+	/*
+	 * clear delta_msr_wait queue to avoid mem leaks: we may free
+	 * the irq here so the queue might never be woken up.  Note
+	 * that we won't end up waiting on delta_msr_wait again since
+	 * any outstanding file descriptors should be pointing at
+	 * hung_up_tty_fops now.
+	 */
+	wake_up_interruptible(&port->delta_msr_wait);
+
+	if (uport) {
+		/* Free the IRQ and disable the port. */
+		uport->ops->shutdown(uport);
+
+		/* Ensure that the IRQ handler isn't running on another CPU. */
+		synchronize_irq(uport->irq);
+	}
+}
+
+static bool uart_carrier_raised(struct tty_port *port)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	int mctrl;
+
+	uport = uart_port_ref(state);
+	/*
+	 * Should never observe uport == NULL since checks for hangup should
+	 * abort the tty_port_block_til_ready() loop before checking for carrier
+	 * raised -- but report carrier raised if it does anyway so open will
+	 * continue and not sleep
+	 */
+	if (WARN_ON(!uport))
+		return true;
+	spin_lock_irq(&uport->lock);
+	uart_enable_ms(uport);
+	mctrl = uport->ops->get_mctrl(uport);
+	spin_unlock_irq(&uport->lock);
+	uart_port_deref(uport);
+
+	return mctrl & TIOCM_CAR;
+}
+
+static void uart_dtr_rts(struct tty_port *port, bool active)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+
+	uport = uart_port_ref(state);
+	if (!uport)
+		return;
+	uart_port_dtr_rts(uport, active);
+	uart_port_deref(uport);
+}
+
+static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + tty->index;
+
+	tty->driver_data = state;
+
+	return tty_standard_install(driver, tty);
+}
+
+/*
+ * Calls to uart_open are serialised by the tty_lock in
+ *   drivers/tty/tty_io.c:tty_open()
+ * Note that if this fails, then uart_close() _will_ be called.
+ *
+ * In time, we want to scrap the "opening nonpresent ports"
+ * behaviour and implement an alternative way for setserial
+ * to set base addresses/ports/types.  This will allow us to
+ * get rid of a certain amount of extra tests.
+ */
+static int uart_open(struct tty_struct *tty, struct file *filp)
+{
+	struct uart_state *state = tty->driver_data;
+	int retval;
+
+	retval = tty_port_open(&state->port, tty, filp);
+	if (retval > 0)
+		retval = 0;
+
+	return retval;
+}
+
+static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	int ret;
+
+	uport = uart_port_check(state);
+	if (!uport || uport->flags & UPF_DEAD)
+		return -ENXIO;
+
+	/*
+	 * Start up the serial port.
+	 */
+	ret = uart_startup(tty, state, false);
+	if (ret > 0)
+		tty_port_set_active(port, true);
+
+	return ret;
+}
+
+static const char *uart_type(struct uart_port *port)
+{
+	const char *str = NULL;
+
+	if (port->ops->type)
+		str = port->ops->type(port);
+
+	if (!str)
+		str = "unknown";
+
+	return str;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
+{
+	struct uart_state *state = drv->state + i;
+	struct tty_port *port = &state->port;
+	enum uart_pm_state pm_state;
+	struct uart_port *uport;
+	char stat_buf[32];
+	unsigned int status;
+	int mmio;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (!uport)
+		goto out;
+
+	mmio = uport->iotype >= UPIO_MEM;
+	seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
+			uport->line, uart_type(uport),
+			mmio ? "mmio:0x" : "port:",
+			mmio ? (unsigned long long)uport->mapbase
+			     : (unsigned long long)uport->iobase,
+			uport->irq);
+
+	if (uport->type == PORT_UNKNOWN) {
+		seq_putc(m, '\n');
+		goto out;
+	}
+
+	if (capable(CAP_SYS_ADMIN)) {
+		pm_state = state->pm_state;
+		if (pm_state != UART_PM_STATE_ON)
+			uart_change_pm(state, UART_PM_STATE_ON);
+		spin_lock_irq(&uport->lock);
+		status = uport->ops->get_mctrl(uport);
+		spin_unlock_irq(&uport->lock);
+		if (pm_state != UART_PM_STATE_ON)
+			uart_change_pm(state, pm_state);
+
+		seq_printf(m, " tx:%d rx:%d",
+				uport->icount.tx, uport->icount.rx);
+		if (uport->icount.frame)
+			seq_printf(m, " fe:%d",	uport->icount.frame);
+		if (uport->icount.parity)
+			seq_printf(m, " pe:%d",	uport->icount.parity);
+		if (uport->icount.brk)
+			seq_printf(m, " brk:%d", uport->icount.brk);
+		if (uport->icount.overrun)
+			seq_printf(m, " oe:%d", uport->icount.overrun);
+		if (uport->icount.buf_overrun)
+			seq_printf(m, " bo:%d", uport->icount.buf_overrun);
+
+#define INFOBIT(bit, str) \
+	if (uport->mctrl & (bit)) \
+		strncat(stat_buf, (str), sizeof(stat_buf) - \
+			strlen(stat_buf) - 2)
+#define STATBIT(bit, str) \
+	if (status & (bit)) \
+		strncat(stat_buf, (str), sizeof(stat_buf) - \
+		       strlen(stat_buf) - 2)
+
+		stat_buf[0] = '\0';
+		stat_buf[1] = '\0';
+		INFOBIT(TIOCM_RTS, "|RTS");
+		STATBIT(TIOCM_CTS, "|CTS");
+		INFOBIT(TIOCM_DTR, "|DTR");
+		STATBIT(TIOCM_DSR, "|DSR");
+		STATBIT(TIOCM_CAR, "|CD");
+		STATBIT(TIOCM_RNG, "|RI");
+		if (stat_buf[0])
+			stat_buf[0] = ' ';
+
+		seq_puts(m, stat_buf);
+	}
+	seq_putc(m, '\n');
+#undef STATBIT
+#undef INFOBIT
+out:
+	mutex_unlock(&port->mutex);
+}
+
+static int uart_proc_show(struct seq_file *m, void *v)
+{
+	struct tty_driver *ttydrv = m->private;
+	struct uart_driver *drv = ttydrv->driver_state;
+	int i;
+
+	seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
+	for (i = 0; i < drv->nr; i++)
+		uart_line_info(m, drv, i);
+	return 0;
+}
+#endif
+
+static void uart_port_spin_lock_init(struct uart_port *port)
+{
+	spin_lock_init(&port->lock);
+	lockdep_set_class(&port->lock, &port_lock_key);
+}
+
+#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
+/**
+ * uart_console_write - write a console message to a serial port
+ * @port: the port to write the message
+ * @s: array of characters
+ * @count: number of characters in string to write
+ * @putchar: function to write character to port
+ */
+void uart_console_write(struct uart_port *port, const char *s,
+			unsigned int count,
+			void (*putchar)(struct uart_port *, unsigned char))
+{
+	unsigned int i;
+
+	for (i = 0; i < count; i++, s++) {
+		if (*s == '\n')
+			putchar(port, '\r');
+		putchar(port, *s);
+	}
+}
+EXPORT_SYMBOL_GPL(uart_console_write);
+
+/**
+ * uart_get_console - get uart port for console
+ * @ports: ports to search in
+ * @nr: number of @ports
+ * @co: console to search for
+ * Returns: uart_port for the console @co
+ *
+ * Check whether an invalid uart number has been specified (as @co->index), and
+ * if so, search for the first available port that does have console support.
+ */
+struct uart_port * __init
+uart_get_console(struct uart_port *ports, int nr, struct console *co)
+{
+	int idx = co->index;
+
+	if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
+				     ports[idx].membase == NULL))
+		for (idx = 0; idx < nr; idx++)
+			if (ports[idx].iobase != 0 ||
+			    ports[idx].membase != NULL)
+				break;
+
+	co->index = idx;
+
+	return ports + idx;
+}
+
+/**
+ * uart_parse_earlycon - Parse earlycon options
+ * @p:	     ptr to 2nd field (ie., just beyond '<name>,')
+ * @iotype:  ptr for decoded iotype (out)
+ * @addr:    ptr for decoded mapbase/iobase (out)
+ * @options: ptr for <options> field; %NULL if not present (out)
+ *
+ * Decodes earlycon kernel command line parameters of the form:
+ *  * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
+ *  * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
+ *
+ * The optional form:
+ *  * earlycon=<name>,0x<addr>,<options>
+ *  * console=<name>,0x<addr>,<options>
+ *
+ * is also accepted; the returned @iotype will be %UPIO_MEM.
+ *
+ * Returns: 0 on success or -%EINVAL on failure
+ */
+int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
+			char **options)
+{
+	if (strncmp(p, "mmio,", 5) == 0) {
+		*iotype = UPIO_MEM;
+		p += 5;
+	} else if (strncmp(p, "mmio16,", 7) == 0) {
+		*iotype = UPIO_MEM16;
+		p += 7;
+	} else if (strncmp(p, "mmio32,", 7) == 0) {
+		*iotype = UPIO_MEM32;
+		p += 7;
+	} else if (strncmp(p, "mmio32be,", 9) == 0) {
+		*iotype = UPIO_MEM32BE;
+		p += 9;
+	} else if (strncmp(p, "mmio32native,", 13) == 0) {
+		*iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
+			UPIO_MEM32BE : UPIO_MEM32;
+		p += 13;
+	} else if (strncmp(p, "io,", 3) == 0) {
+		*iotype = UPIO_PORT;
+		p += 3;
+	} else if (strncmp(p, "0x", 2) == 0) {
+		*iotype = UPIO_MEM;
+	} else {
+		return -EINVAL;
+	}
+
+	/*
+	 * Before you replace it with kstrtoull(), think about options separator
+	 * (',') it will not tolerate
+	 */
+	*addr = simple_strtoull(p, NULL, 0);
+	p = strchr(p, ',');
+	if (p)
+		p++;
+
+	*options = p;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uart_parse_earlycon);
+
+/**
+ * uart_parse_options - Parse serial port baud/parity/bits/flow control.
+ * @options: pointer to option string
+ * @baud: pointer to an 'int' variable for the baud rate.
+ * @parity: pointer to an 'int' variable for the parity.
+ * @bits: pointer to an 'int' variable for the number of data bits.
+ * @flow: pointer to an 'int' variable for the flow control character.
+ *
+ * uart_parse_options() decodes a string containing the serial console
+ * options. The format of the string is <baud><parity><bits><flow>,
+ * eg: 115200n8r
+ */
+void
+uart_parse_options(const char *options, int *baud, int *parity,
+		   int *bits, int *flow)
+{
+	const char *s = options;
+
+	*baud = simple_strtoul(s, NULL, 10);
+	while (*s >= '0' && *s <= '9')
+		s++;
+	if (*s)
+		*parity = *s++;
+	if (*s)
+		*bits = *s++ - '0';
+	if (*s)
+		*flow = *s;
+}
+EXPORT_SYMBOL_GPL(uart_parse_options);
+
+/**
+ * uart_set_options - setup the serial console parameters
+ * @port: pointer to the serial ports uart_port structure
+ * @co: console pointer
+ * @baud: baud rate
+ * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
+ * @bits: number of data bits
+ * @flow: flow control character - 'r' (rts)
+ *
+ * Locking: Caller must hold console_list_lock in order to serialize
+ * early initialization of the serial-console lock.
+ */
+int
+uart_set_options(struct uart_port *port, struct console *co,
+		 int baud, int parity, int bits, int flow)
+{
+	struct ktermios termios;
+	static struct ktermios dummy;
+
+	/*
+	 * Ensure that the serial-console lock is initialised early.
+	 *
+	 * Note that the console-registered check is needed because
+	 * kgdboc can call uart_set_options() for an already registered
+	 * console via tty_find_polling_driver() and uart_poll_init().
+	 */
+	if (!uart_console_registered_locked(port) && !port->console_reinit)
+		uart_port_spin_lock_init(port);
+
+	memset(&termios, 0, sizeof(struct ktermios));
+
+	termios.c_cflag |= CREAD | HUPCL | CLOCAL;
+	tty_termios_encode_baud_rate(&termios, baud, baud);
+
+	if (bits == 7)
+		termios.c_cflag |= CS7;
+	else
+		termios.c_cflag |= CS8;
+
+	switch (parity) {
+	case 'o': case 'O':
+		termios.c_cflag |= PARODD;
+		fallthrough;
+	case 'e': case 'E':
+		termios.c_cflag |= PARENB;
+		break;
+	}
+
+	if (flow == 'r')
+		termios.c_cflag |= CRTSCTS;
+
+	/*
+	 * some uarts on other side don't support no flow control.
+	 * So we set * DTR in host uart to make them happy
+	 */
+	port->mctrl |= TIOCM_DTR;
+
+	port->ops->set_termios(port, &termios, &dummy);
+	/*
+	 * Allow the setting of the UART parameters with a NULL console
+	 * too:
+	 */
+	if (co) {
+		co->cflag = termios.c_cflag;
+		co->ispeed = termios.c_ispeed;
+		co->ospeed = termios.c_ospeed;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uart_set_options);
+#endif /* CONFIG_SERIAL_CORE_CONSOLE */
+
+/**
+ * uart_change_pm - set power state of the port
+ *
+ * @state: port descriptor
+ * @pm_state: new state
+ *
+ * Locking: port->mutex has to be held
+ */
+static void uart_change_pm(struct uart_state *state,
+			   enum uart_pm_state pm_state)
+{
+	struct uart_port *port = uart_port_check(state);
+
+	if (state->pm_state != pm_state) {
+		if (port && port->ops->pm)
+			port->ops->pm(port, pm_state, state->pm_state);
+		state->pm_state = pm_state;
+	}
+}
+
+struct uart_match {
+	struct uart_port *port;
+	struct uart_driver *driver;
+};
+
+static int serial_match_port(struct device *dev, void *data)
+{
+	struct uart_match *match = data;
+	struct tty_driver *tty_drv = match->driver->tty_driver;
+	dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
+		match->port->line;
+
+	return dev->devt == devt; /* Actually, only one tty per port */
+}
+
+int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
+{
+	struct uart_state *state = drv->state + uport->line;
+	struct tty_port *port = &state->port;
+	struct device *tty_dev;
+	struct uart_match match = {uport, drv};
+
+	mutex_lock(&port->mutex);
+
+	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+	if (tty_dev && device_may_wakeup(tty_dev)) {
+		enable_irq_wake(uport->irq);
+		put_device(tty_dev);
+		mutex_unlock(&port->mutex);
+		return 0;
+	}
+	put_device(tty_dev);
+
+	/*
+	 * Nothing to do if the console is not suspending
+	 * except stop_rx to prevent any asynchronous data
+	 * over RX line. However ensure that we will be
+	 * able to Re-start_rx later.
+	 */
+	if (!console_suspend_enabled && uart_console(uport)) {
+		if (uport->ops->start_rx) {
+			spin_lock_irq(&uport->lock);
+			uport->ops->stop_rx(uport);
+			spin_unlock_irq(&uport->lock);
+		}
+		goto unlock;
+	}
+
+	uport->suspended = 1;
+
+	if (tty_port_initialized(port)) {
+		const struct uart_ops *ops = uport->ops;
+		int tries;
+		unsigned int mctrl;
+
+		tty_port_set_suspended(port, true);
+		tty_port_set_initialized(port, false);
+
+		spin_lock_irq(&uport->lock);
+		ops->stop_tx(uport);
+		if (!(uport->rs485.flags & SER_RS485_ENABLED))
+			ops->set_mctrl(uport, 0);
+		/* save mctrl so it can be restored on resume */
+		mctrl = uport->mctrl;
+		uport->mctrl = 0;
+		ops->stop_rx(uport);
+		spin_unlock_irq(&uport->lock);
+
+		/*
+		 * Wait for the transmitter to empty.
+		 */
+		for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
+			msleep(10);
+		if (!tries)
+			dev_err(uport->dev, "%s: Unable to drain transmitter\n",
+				uport->name);
+
+		ops->shutdown(uport);
+		uport->mctrl = mctrl;
+	}
+
+	/*
+	 * Disable the console device before suspending.
+	 */
+	if (uart_console(uport))
+		console_stop(uport->cons);
+
+	uart_change_pm(state, UART_PM_STATE_OFF);
+unlock:
+	mutex_unlock(&port->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(uart_suspend_port);
+
+int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
+{
+	struct uart_state *state = drv->state + uport->line;
+	struct tty_port *port = &state->port;
+	struct device *tty_dev;
+	struct uart_match match = {uport, drv};
+	struct ktermios termios;
+
+	mutex_lock(&port->mutex);
+
+	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+	if (!uport->suspended && device_may_wakeup(tty_dev)) {
+		if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
+			disable_irq_wake(uport->irq);
+		put_device(tty_dev);
+		mutex_unlock(&port->mutex);
+		return 0;
+	}
+	put_device(tty_dev);
+	uport->suspended = 0;
+
+	/*
+	 * Re-enable the console device after suspending.
+	 */
+	if (uart_console(uport)) {
+		/*
+		 * First try to use the console cflag setting.
+		 */
+		memset(&termios, 0, sizeof(struct ktermios));
+		termios.c_cflag = uport->cons->cflag;
+		termios.c_ispeed = uport->cons->ispeed;
+		termios.c_ospeed = uport->cons->ospeed;
+
+		/*
+		 * If that's unset, use the tty termios setting.
+		 */
+		if (port->tty && termios.c_cflag == 0)
+			termios = port->tty->termios;
+
+		if (console_suspend_enabled)
+			uart_change_pm(state, UART_PM_STATE_ON);
+		uport->ops->set_termios(uport, &termios, NULL);
+		if (!console_suspend_enabled && uport->ops->start_rx) {
+			spin_lock_irq(&uport->lock);
+			uport->ops->start_rx(uport);
+			spin_unlock_irq(&uport->lock);
+		}
+		if (console_suspend_enabled)
+			console_start(uport->cons);
+	}
+
+	if (tty_port_suspended(port)) {
+		const struct uart_ops *ops = uport->ops;
+		int ret;
+
+		uart_change_pm(state, UART_PM_STATE_ON);
+		spin_lock_irq(&uport->lock);
+		if (!(uport->rs485.flags & SER_RS485_ENABLED))
+			ops->set_mctrl(uport, 0);
+		spin_unlock_irq(&uport->lock);
+		if (console_suspend_enabled || !uart_console(uport)) {
+			/* Protected by port mutex for now */
+			struct tty_struct *tty = port->tty;
+
+			ret = ops->startup(uport);
+			if (ret == 0) {
+				if (tty)
+					uart_change_line_settings(tty, state, NULL);
+				uart_rs485_config(uport);
+				spin_lock_irq(&uport->lock);
+				if (!(uport->rs485.flags & SER_RS485_ENABLED))
+					ops->set_mctrl(uport, uport->mctrl);
+				ops->start_tx(uport);
+				spin_unlock_irq(&uport->lock);
+				tty_port_set_initialized(port, true);
+			} else {
+				/*
+				 * Failed to resume - maybe hardware went away?
+				 * Clear the "initialized" flag so we won't try
+				 * to call the low level drivers shutdown method.
+				 */
+				uart_shutdown(tty, state);
+			}
+		}
+
+		tty_port_set_suspended(port, false);
+	}
+
+	mutex_unlock(&port->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(uart_resume_port);
+
+static inline void
+uart_report_port(struct uart_driver *drv, struct uart_port *port)
+{
+	char address[64];
+
+	switch (port->iotype) {
+	case UPIO_PORT:
+		snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
+		break;
+	case UPIO_HUB6:
+		snprintf(address, sizeof(address),
+			 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
+		break;
+	case UPIO_MEM:
+	case UPIO_MEM16:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_AU:
+	case UPIO_TSI:
+		snprintf(address, sizeof(address),
+			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
+		break;
+	default:
+		strscpy(address, "*unknown*", sizeof(address));
+		break;
+	}
+
+	pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
+	       port->dev ? dev_name(port->dev) : "",
+	       port->dev ? ": " : "",
+	       port->name,
+	       address, port->irq, port->uartclk / 16, uart_type(port));
+
+	/* The magic multiplier feature is a bit obscure, so report it too.  */
+	if (port->flags & UPF_MAGIC_MULTIPLIER)
+		pr_info("%s%s%s extra baud rates supported: %d, %d",
+			port->dev ? dev_name(port->dev) : "",
+			port->dev ? ": " : "",
+			port->name,
+			port->uartclk / 8, port->uartclk / 4);
+}
+
+static void
+uart_configure_port(struct uart_driver *drv, struct uart_state *state,
+		    struct uart_port *port)
+{
+	unsigned int flags;
+
+	/*
+	 * If there isn't a port here, don't do anything further.
+	 */
+	if (!port->iobase && !port->mapbase && !port->membase)
+		return;
+
+	/*
+	 * Now do the auto configuration stuff.  Note that config_port
+	 * is expected to claim the resources and map the port for us.
+	 */
+	flags = 0;
+	if (port->flags & UPF_AUTO_IRQ)
+		flags |= UART_CONFIG_IRQ;
+	if (port->flags & UPF_BOOT_AUTOCONF) {
+		if (!(port->flags & UPF_FIXED_TYPE)) {
+			port->type = PORT_UNKNOWN;
+			flags |= UART_CONFIG_TYPE;
+		}
+		port->ops->config_port(port, flags);
+	}
+
+	if (port->type != PORT_UNKNOWN) {
+		unsigned long flags;
+
+		uart_report_port(drv, port);
+
+		/* Power up port for set_mctrl() */
+		uart_change_pm(state, UART_PM_STATE_ON);
+
+		/*
+		 * Ensure that the modem control lines are de-activated.
+		 * keep the DTR setting that is set in uart_set_options()
+		 * We probably don't need a spinlock around this, but
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+		port->mctrl &= TIOCM_DTR;
+		if (!(port->rs485.flags & SER_RS485_ENABLED))
+			port->ops->set_mctrl(port, port->mctrl);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		uart_rs485_config(port);
+
+		/*
+		 * If this driver supports console, and it hasn't been
+		 * successfully registered yet, try to re-register it.
+		 * It may be that the port was not available.
+		 */
+		if (port->cons && !console_is_registered(port->cons))
+			register_console(port->cons);
+
+		/*
+		 * Power down all ports by default, except the
+		 * console if we have one.
+		 */
+		if (!uart_console(port))
+			uart_change_pm(state, UART_PM_STATE_OFF);
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static int uart_poll_init(struct tty_driver *driver, int line, char *options)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + line;
+	enum uart_pm_state pm_state;
+	struct tty_port *tport;
+	struct uart_port *port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret = 0;
+
+	tport = &state->port;
+	mutex_lock(&tport->mutex);
+
+	port = uart_port_check(state);
+	if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
+		ret = -1;
+		goto out;
+	}
+
+	pm_state = state->pm_state;
+	uart_change_pm(state, UART_PM_STATE_ON);
+
+	if (port->ops->poll_init) {
+		/*
+		 * We don't set initialized as we only initialized the hw,
+		 * e.g. state->xmit is still uninitialized.
+		 */
+		if (!tty_port_initialized(tport))
+			ret = port->ops->poll_init(port);
+	}
+
+	if (!ret && options) {
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+		console_list_lock();
+		ret = uart_set_options(port, NULL, baud, parity, bits, flow);
+		console_list_unlock();
+	}
+out:
+	if (ret)
+		uart_change_pm(state, pm_state);
+	mutex_unlock(&tport->mutex);
+	return ret;
+}
+
+static int uart_poll_get_char(struct tty_driver *driver, int line)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + line;
+	struct uart_port *port;
+	int ret = -1;
+
+	port = uart_port_ref(state);
+	if (port) {
+		ret = port->ops->poll_get_char(port);
+		uart_port_deref(port);
+	}
+
+	return ret;
+}
+
+static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + line;
+	struct uart_port *port;
+
+	port = uart_port_ref(state);
+	if (!port)
+		return;
+
+	if (ch == '\n')
+		port->ops->poll_put_char(port, '\r');
+	port->ops->poll_put_char(port, ch);
+	uart_port_deref(port);
+}
+#endif
+
+static const struct tty_operations uart_ops = {
+	.install	= uart_install,
+	.open		= uart_open,
+	.close		= uart_close,
+	.write		= uart_write,
+	.put_char	= uart_put_char,
+	.flush_chars	= uart_flush_chars,
+	.write_room	= uart_write_room,
+	.chars_in_buffer= uart_chars_in_buffer,
+	.flush_buffer	= uart_flush_buffer,
+	.ioctl		= uart_ioctl,
+	.throttle	= uart_throttle,
+	.unthrottle	= uart_unthrottle,
+	.send_xchar	= uart_send_xchar,
+	.set_termios	= uart_set_termios,
+	.set_ldisc	= uart_set_ldisc,
+	.stop		= uart_stop,
+	.start		= uart_start,
+	.hangup		= uart_hangup,
+	.break_ctl	= uart_break_ctl,
+	.wait_until_sent= uart_wait_until_sent,
+#ifdef CONFIG_PROC_FS
+	.proc_show	= uart_proc_show,
+#endif
+	.tiocmget	= uart_tiocmget,
+	.tiocmset	= uart_tiocmset,
+	.set_serial	= uart_set_info_user,
+	.get_serial	= uart_get_info_user,
+	.get_icount	= uart_get_icount,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init	= uart_poll_init,
+	.poll_get_char	= uart_poll_get_char,
+	.poll_put_char	= uart_poll_put_char,
+#endif
+};
+
+static const struct tty_port_operations uart_port_ops = {
+	.carrier_raised = uart_carrier_raised,
+	.dtr_rts	= uart_dtr_rts,
+	.activate	= uart_port_activate,
+	.shutdown	= uart_tty_port_shutdown,
+};
+
+/**
+ * uart_register_driver - register a driver with the uart core layer
+ * @drv: low level driver structure
+ *
+ * Register a uart driver with the core driver. We in turn register with the
+ * tty layer, and initialise the core driver per-port state.
+ *
+ * We have a proc file in /proc/tty/driver which is named after the normal
+ * driver.
+ *
+ * @drv->port should be %NULL, and the per-port structures should be registered
+ * using uart_add_one_port() after this call has succeeded.
+ *
+ * Locking: none, Interrupts: enabled
+ */
+int uart_register_driver(struct uart_driver *drv)
+{
+	struct tty_driver *normal;
+	int i, retval = -ENOMEM;
+
+	BUG_ON(drv->state);
+
+	/*
+	 * Maybe we should be using a slab cache for this, especially if
+	 * we have a large number of ports to handle.
+	 */
+	drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
+	if (!drv->state)
+		goto out;
+
+	normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(normal)) {
+		retval = PTR_ERR(normal);
+		goto out_kfree;
+	}
+
+	drv->tty_driver = normal;
+
+	normal->driver_name	= drv->driver_name;
+	normal->name		= drv->dev_name;
+	normal->major		= drv->major;
+	normal->minor_start	= drv->minor;
+	normal->type		= TTY_DRIVER_TYPE_SERIAL;
+	normal->subtype		= SERIAL_TYPE_NORMAL;
+	normal->init_termios	= tty_std_termios;
+	normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
+	normal->driver_state    = drv;
+	tty_set_operations(normal, &uart_ops);
+
+	/*
+	 * Initialise the UART state(s).
+	 */
+	for (i = 0; i < drv->nr; i++) {
+		struct uart_state *state = drv->state + i;
+		struct tty_port *port = &state->port;
+
+		tty_port_init(port);
+		port->ops = &uart_port_ops;
+	}
+
+	retval = tty_register_driver(normal);
+	if (retval >= 0)
+		return retval;
+
+	for (i = 0; i < drv->nr; i++)
+		tty_port_destroy(&drv->state[i].port);
+	tty_driver_kref_put(normal);
+out_kfree:
+	kfree(drv->state);
+out:
+	return retval;
+}
+EXPORT_SYMBOL(uart_register_driver);
+
+/**
+ * uart_unregister_driver - remove a driver from the uart core layer
+ * @drv: low level driver structure
+ *
+ * Remove all references to a driver from the core driver. The low level
+ * driver must have removed all its ports via the uart_remove_one_port() if it
+ * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.)
+ *
+ * Locking: none, Interrupts: enabled
+ */
+void uart_unregister_driver(struct uart_driver *drv)
+{
+	struct tty_driver *p = drv->tty_driver;
+	unsigned int i;
+
+	tty_unregister_driver(p);
+	tty_driver_kref_put(p);
+	for (i = 0; i < drv->nr; i++)
+		tty_port_destroy(&drv->state[i].port);
+	kfree(drv->state);
+	drv->state = NULL;
+	drv->tty_driver = NULL;
+}
+EXPORT_SYMBOL(uart_unregister_driver);
+
+struct tty_driver *uart_console_device(struct console *co, int *index)
+{
+	struct uart_driver *p = co->data;
+	*index = co->index;
+	return p->tty_driver;
+}
+EXPORT_SYMBOL_GPL(uart_console_device);
+
+static ssize_t uartclk_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.baud_base * 16);
+}
+
+static ssize_t type_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.type);
+}
+
+static ssize_t line_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.line);
+}
+
+static ssize_t port_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+	unsigned long ioaddr;
+
+	uart_get_info(port, &tmp);
+	ioaddr = tmp.port;
+	if (HIGH_BITS_OFFSET)
+		ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
+	return sprintf(buf, "0x%lX\n", ioaddr);
+}
+
+static ssize_t irq_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.irq);
+}
+
+static ssize_t flags_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "0x%X\n", tmp.flags);
+}
+
+static ssize_t xmit_fifo_size_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.xmit_fifo_size);
+}
+
+static ssize_t close_delay_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.close_delay);
+}
+
+static ssize_t closing_wait_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.closing_wait);
+}
+
+static ssize_t custom_divisor_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.custom_divisor);
+}
+
+static ssize_t io_type_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.io_type);
+}
+
+static ssize_t iomem_base_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base);
+}
+
+static ssize_t iomem_reg_shift_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct serial_struct tmp;
+	struct tty_port *port = dev_get_drvdata(dev);
+
+	uart_get_info(port, &tmp);
+	return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
+}
+
+static ssize_t console_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	bool console = false;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (uport)
+		console = uart_console_registered(uport);
+	mutex_unlock(&port->mutex);
+
+	return sprintf(buf, "%c\n", console ? 'Y' : 'N');
+}
+
+static ssize_t console_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	bool oldconsole, newconsole;
+	int ret;
+
+	ret = kstrtobool(buf, &newconsole);
+	if (ret)
+		return ret;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (uport) {
+		oldconsole = uart_console_registered(uport);
+		if (oldconsole && !newconsole) {
+			ret = unregister_console(uport->cons);
+		} else if (!oldconsole && newconsole) {
+			if (uart_console(uport)) {
+				uport->console_reinit = 1;
+				register_console(uport->cons);
+			} else {
+				ret = -ENOENT;
+			}
+		}
+	} else {
+		ret = -ENXIO;
+	}
+	mutex_unlock(&port->mutex);
+
+	return ret < 0 ? ret : count;
+}
+
+static DEVICE_ATTR_RO(uartclk);
+static DEVICE_ATTR_RO(type);
+static DEVICE_ATTR_RO(line);
+static DEVICE_ATTR_RO(port);
+static DEVICE_ATTR_RO(irq);
+static DEVICE_ATTR_RO(flags);
+static DEVICE_ATTR_RO(xmit_fifo_size);
+static DEVICE_ATTR_RO(close_delay);
+static DEVICE_ATTR_RO(closing_wait);
+static DEVICE_ATTR_RO(custom_divisor);
+static DEVICE_ATTR_RO(io_type);
+static DEVICE_ATTR_RO(iomem_base);
+static DEVICE_ATTR_RO(iomem_reg_shift);
+static DEVICE_ATTR_RW(console);
+
+static struct attribute *tty_dev_attrs[] = {
+	&dev_attr_uartclk.attr,
+	&dev_attr_type.attr,
+	&dev_attr_line.attr,
+	&dev_attr_port.attr,
+	&dev_attr_irq.attr,
+	&dev_attr_flags.attr,
+	&dev_attr_xmit_fifo_size.attr,
+	&dev_attr_close_delay.attr,
+	&dev_attr_closing_wait.attr,
+	&dev_attr_custom_divisor.attr,
+	&dev_attr_io_type.attr,
+	&dev_attr_iomem_base.attr,
+	&dev_attr_iomem_reg_shift.attr,
+	&dev_attr_console.attr,
+	NULL
+};
+
+static const struct attribute_group tty_dev_attr_group = {
+	.attrs = tty_dev_attrs,
+};
+
+/**
+ * serial_core_add_one_port - attach a driver-defined port structure
+ * @drv: pointer to the uart low level driver structure for this port
+ * @uport: uart port structure to use for this port.
+ *
+ * Context: task context, might sleep
+ *
+ * This allows the driver @drv to register its own uart_port structure with the
+ * core driver. The main purpose is to allow the low level uart drivers to
+ * expand uart_port, rather than having yet more levels of structures.
+ * Caller must hold port_mutex.
+ */
+static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *uport)
+{
+	struct uart_state *state;
+	struct tty_port *port;
+	int ret = 0;
+	struct device *tty_dev;
+	int num_groups;
+
+	if (uport->line >= drv->nr)
+		return -EINVAL;
+
+	state = drv->state + uport->line;
+	port = &state->port;
+
+	mutex_lock(&port->mutex);
+	if (state->uart_port) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Link the port to the driver state table and vice versa */
+	atomic_set(&state->refcount, 1);
+	init_waitqueue_head(&state->remove_wait);
+	state->uart_port = uport;
+	uport->state = state;
+
+	state->pm_state = UART_PM_STATE_UNDEFINED;
+	uport->cons = drv->cons;
+	uport->minor = drv->tty_driver->minor_start + uport->line;
+	uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
+				drv->tty_driver->name_base + uport->line);
+	if (!uport->name) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * If this port is in use as a console then the spinlock is already
+	 * initialised.
+	 */
+	if (!uart_console_registered(uport))
+		uart_port_spin_lock_init(uport);
+
+	if (uport->cons && uport->dev)
+		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
+
+	tty_port_link_device(port, drv->tty_driver, uport->line);
+	uart_configure_port(drv, state, uport);
+
+	port->console = uart_console(uport);
+
+	num_groups = 2;
+	if (uport->attr_group)
+		num_groups++;
+
+	uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
+				    GFP_KERNEL);
+	if (!uport->tty_groups) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	uport->tty_groups[0] = &tty_dev_attr_group;
+	if (uport->attr_group)
+		uport->tty_groups[1] = uport->attr_group;
+
+	/*
+	 * Register the port whether it's detected or not.  This allows
+	 * setserial to be used to alter this port's parameters.
+	 */
+	tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
+			uport->line, uport->dev, port, uport->tty_groups);
+	if (!IS_ERR(tty_dev)) {
+		device_set_wakeup_capable(tty_dev, 1);
+	} else {
+		dev_err(uport->dev, "Cannot register tty device on line %d\n",
+		       uport->line);
+	}
+
+ out:
+	mutex_unlock(&port->mutex);
+
+	return ret;
+}
+
+/**
+ * serial_core_remove_one_port - detach a driver defined port structure
+ * @drv: pointer to the uart low level driver structure for this port
+ * @uport: uart port structure for this port
+ *
+ * Context: task context, might sleep
+ *
+ * This unhooks (and hangs up) the specified port structure from the core
+ * driver. No further calls will be made to the low-level code for this port.
+ * Caller must hold port_mutex.
+ */
+static void serial_core_remove_one_port(struct uart_driver *drv,
+					struct uart_port *uport)
+{
+	struct uart_state *state = drv->state + uport->line;
+	struct tty_port *port = &state->port;
+	struct uart_port *uart_port;
+	struct tty_struct *tty;
+
+	mutex_lock(&port->mutex);
+	uart_port = uart_port_check(state);
+	if (uart_port != uport)
+		dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
+			  uart_port, uport);
+
+	if (!uart_port) {
+		mutex_unlock(&port->mutex);
+		return;
+	}
+	mutex_unlock(&port->mutex);
+
+	/*
+	 * Remove the devices from the tty layer
+	 */
+	tty_port_unregister_device(port, drv->tty_driver, uport->line);
+
+	tty = tty_port_tty_get(port);
+	if (tty) {
+		tty_vhangup(port->tty);
+		tty_kref_put(tty);
+	}
+
+	/*
+	 * If the port is used as a console, unregister it
+	 */
+	if (uart_console(uport))
+		unregister_console(uport->cons);
+
+	/*
+	 * Free the port IO and memory resources, if any.
+	 */
+	if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
+		uport->ops->release_port(uport);
+	kfree(uport->tty_groups);
+	kfree(uport->name);
+
+	/*
+	 * Indicate that there isn't a port here anymore.
+	 */
+	uport->type = PORT_UNKNOWN;
+	uport->port_dev = NULL;
+
+	mutex_lock(&port->mutex);
+	WARN_ON(atomic_dec_return(&state->refcount) < 0);
+	wait_event(state->remove_wait, !atomic_read(&state->refcount));
+	state->uart_port = NULL;
+	mutex_unlock(&port->mutex);
+}
+
+/**
+ * uart_match_port - are the two ports equivalent?
+ * @port1: first port
+ * @port2: second port
+ *
+ * This utility function can be used to determine whether two uart_port
+ * structures describe the same port.
+ */
+bool uart_match_port(const struct uart_port *port1,
+		const struct uart_port *port2)
+{
+	if (port1->iotype != port2->iotype)
+		return false;
+
+	switch (port1->iotype) {
+	case UPIO_PORT:
+		return port1->iobase == port2->iobase;
+	case UPIO_HUB6:
+		return port1->iobase == port2->iobase &&
+		       port1->hub6   == port2->hub6;
+	case UPIO_MEM:
+	case UPIO_MEM16:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_AU:
+	case UPIO_TSI:
+		return port1->mapbase == port2->mapbase;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(uart_match_port);
+
+static struct serial_ctrl_device *
+serial_core_get_ctrl_dev(struct serial_port_device *port_dev)
+{
+	struct device *dev = &port_dev->dev;
+
+	return to_serial_base_ctrl_device(dev->parent);
+}
+
+/*
+ * Find a registered serial core controller device if one exists. Returns
+ * the first device matching the ctrl_id. Caller must hold port_mutex.
+ */
+static struct serial_ctrl_device *serial_core_ctrl_find(struct uart_driver *drv,
+							struct device *phys_dev,
+							int ctrl_id)
+{
+	struct uart_state *state;
+	int i;
+
+	lockdep_assert_held(&port_mutex);
+
+	for (i = 0; i < drv->nr; i++) {
+		state = drv->state + i;
+		if (!state->uart_port || !state->uart_port->port_dev)
+			continue;
+
+		if (state->uart_port->dev == phys_dev &&
+		    state->uart_port->ctrl_id == ctrl_id)
+			return serial_core_get_ctrl_dev(state->uart_port->port_dev);
+	}
+
+	return NULL;
+}
+
+static struct serial_ctrl_device *serial_core_ctrl_device_add(struct uart_port *port)
+{
+	return serial_base_ctrl_add(port, port->dev);
+}
+
+static int serial_core_port_device_add(struct serial_ctrl_device *ctrl_dev,
+				       struct uart_port *port)
+{
+	struct serial_port_device *port_dev;
+
+	port_dev = serial_base_port_add(port, ctrl_dev);
+	if (IS_ERR(port_dev))
+		return PTR_ERR(port_dev);
+
+	port->port_dev = port_dev;
+
+	return 0;
+}
+
+/*
+ * Initialize a serial core port device, and a controller device if needed.
+ */
+int serial_core_register_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct serial_ctrl_device *ctrl_dev, *new_ctrl_dev = NULL;
+	int ret;
+
+	mutex_lock(&port_mutex);
+
+	/*
+	 * Prevent serial_port_runtime_resume() from trying to use the port
+	 * until serial_core_add_one_port() has completed
+	 */
+	port->flags |= UPF_DEAD;
+
+	/* Inititalize a serial core controller device if needed */
+	ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id);
+	if (!ctrl_dev) {
+		new_ctrl_dev = serial_core_ctrl_device_add(port);
+		if (IS_ERR(new_ctrl_dev)) {
+			ret = PTR_ERR(new_ctrl_dev);
+			goto err_unlock;
+		}
+		ctrl_dev = new_ctrl_dev;
+	}
+
+	/*
+	 * Initialize a serial core port device. Tag the port dead to prevent
+	 * serial_port_runtime_resume() trying to do anything until port has
+	 * been registered. It gets cleared by serial_core_add_one_port().
+	 */
+	ret = serial_core_port_device_add(ctrl_dev, port);
+	if (ret)
+		goto err_unregister_ctrl_dev;
+
+	ret = serial_core_add_one_port(drv, port);
+	if (ret)
+		goto err_unregister_port_dev;
+
+	port->flags &= ~UPF_DEAD;
+
+	mutex_unlock(&port_mutex);
+
+	return 0;
+
+err_unregister_port_dev:
+	serial_base_port_device_remove(port->port_dev);
+
+err_unregister_ctrl_dev:
+	serial_base_ctrl_device_remove(new_ctrl_dev);
+
+err_unlock:
+	mutex_unlock(&port_mutex);
+
+	return ret;
+}
+
+/*
+ * Removes a serial core port device, and the related serial core controller
+ * device if the last instance.
+ */
+void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct device *phys_dev = port->dev;
+	struct serial_port_device *port_dev = port->port_dev;
+	struct serial_ctrl_device *ctrl_dev = serial_core_get_ctrl_dev(port_dev);
+	int ctrl_id = port->ctrl_id;
+
+	mutex_lock(&port_mutex);
+
+	port->flags |= UPF_DEAD;
+
+	serial_core_remove_one_port(drv, port);
+
+	/* Note that struct uart_port *port is no longer valid at this point */
+	serial_base_port_device_remove(port_dev);
+
+	/* Drop the serial core controller device if no ports are using it */
+	if (!serial_core_ctrl_find(drv, phys_dev, ctrl_id))
+		serial_base_ctrl_device_remove(ctrl_dev);
+
+	mutex_unlock(&port_mutex);
+}
+
+/**
+ * uart_handle_dcd_change - handle a change of carrier detect state
+ * @uport: uart_port structure for the open port
+ * @active: new carrier detect status
+ *
+ * Caller must hold uport->lock.
+ */
+void uart_handle_dcd_change(struct uart_port *uport, bool active)
+{
+	struct tty_port *port = &uport->state->port;
+	struct tty_struct *tty = port->tty;
+	struct tty_ldisc *ld;
+
+	lockdep_assert_held_once(&uport->lock);
+
+	if (tty) {
+		ld = tty_ldisc_ref(tty);
+		if (ld) {
+			if (ld->ops->dcd_change)
+				ld->ops->dcd_change(tty, active);
+			tty_ldisc_deref(ld);
+		}
+	}
+
+	uport->icount.dcd++;
+
+	if (uart_dcd_enabled(uport)) {
+		if (active)
+			wake_up_interruptible(&port->open_wait);
+		else if (tty)
+			tty_hangup(tty);
+	}
+}
+EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
+
+/**
+ * uart_handle_cts_change - handle a change of clear-to-send state
+ * @uport: uart_port structure for the open port
+ * @active: new clear-to-send status
+ *
+ * Caller must hold uport->lock.
+ */
+void uart_handle_cts_change(struct uart_port *uport, bool active)
+{
+	lockdep_assert_held_once(&uport->lock);
+
+	uport->icount.cts++;
+
+	if (uart_softcts_mode(uport)) {
+		if (uport->hw_stopped) {
+			if (active) {
+				uport->hw_stopped = false;
+				uport->ops->start_tx(uport);
+				uart_write_wakeup(uport);
+			}
+		} else {
+			if (!active) {
+				uport->hw_stopped = true;
+				uport->ops->stop_tx(uport);
+			}
+		}
+
+	}
+}
+EXPORT_SYMBOL_GPL(uart_handle_cts_change);
+
+/**
+ * uart_insert_char - push a char to the uart layer
+ *
+ * User is responsible to call tty_flip_buffer_push when they are done with
+ * insertion.
+ *
+ * @port: corresponding port
+ * @status: state of the serial port RX buffer (LSR for 8250)
+ * @overrun: mask of overrun bits in @status
+ * @ch: character to push
+ * @flag: flag for the character (see TTY_NORMAL and friends)
+ */
+void uart_insert_char(struct uart_port *port, unsigned int status,
+		      unsigned int overrun, u8 ch, u8 flag)
+{
+	struct tty_port *tport = &port->state->port;
+
+	if ((status & port->ignore_status_mask & ~overrun) == 0)
+		if (tty_insert_flip_char(tport, ch, flag) == 0)
+			++port->icount.buf_overrun;
+
+	/*
+	 * Overrun is special.  Since it's reported immediately,
+	 * it doesn't affect the current character.
+	 */
+	if (status & ~port->ignore_status_mask & overrun)
+		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
+			++port->icount.buf_overrun;
+}
+EXPORT_SYMBOL_GPL(uart_insert_char);
+
+#ifdef CONFIG_MAGIC_SYSRQ_SERIAL
+static const u8 sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE;
+
+static void uart_sysrq_on(struct work_struct *w)
+{
+	int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
+
+	sysrq_toggle_support(1);
+	pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n",
+		sysrq_toggle_seq_len, sysrq_toggle_seq);
+}
+static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
+
+/**
+ * uart_try_toggle_sysrq - Enables SysRq from serial line
+ * @port: uart_port structure where char(s) after BREAK met
+ * @ch: new character in the sequence after received BREAK
+ *
+ * Enables magic SysRq when the required sequence is met on port
+ * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE).
+ *
+ * Returns: %false if @ch is out of enabling sequence and should be
+ * handled some other way, %true if @ch was consumed.
+ */
+bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch)
+{
+	int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
+
+	if (!sysrq_toggle_seq_len)
+		return false;
+
+	BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
+	if (sysrq_toggle_seq[port->sysrq_seq] != ch) {
+		port->sysrq_seq = 0;
+		return false;
+	}
+
+	if (++port->sysrq_seq < sysrq_toggle_seq_len) {
+		port->sysrq = jiffies + SYSRQ_TIMEOUT;
+		return true;
+	}
+
+	schedule_work(&sysrq_enable_work);
+
+	port->sysrq = 0;
+	return true;
+}
+EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq);
+#endif
+
+/**
+ * uart_get_rs485_mode() - retrieve rs485 properties for given uart
+ * @port: uart device's target port
+ *
+ * This function implements the device tree binding described in
+ * Documentation/devicetree/bindings/serial/rs485.txt.
+ */
+int uart_get_rs485_mode(struct uart_port *port)
+{
+	struct serial_rs485 *rs485conf = &port->rs485;
+	struct device *dev = port->dev;
+	enum gpiod_flags dflags;
+	struct gpio_desc *desc;
+	u32 rs485_delay[2];
+	int ret;
+
+	if (!(port->rs485_supported.flags & SER_RS485_ENABLED))
+		return 0;
+
+	ret = device_property_read_u32_array(dev, "rs485-rts-delay",
+					     rs485_delay, 2);
+	if (!ret) {
+		rs485conf->delay_rts_before_send = rs485_delay[0];
+		rs485conf->delay_rts_after_send = rs485_delay[1];
+	} else {
+		rs485conf->delay_rts_before_send = 0;
+		rs485conf->delay_rts_after_send = 0;
+	}
+
+	uart_sanitize_serial_rs485_delays(port, rs485conf);
+
+	/*
+	 * Clear full-duplex and enabled flags, set RTS polarity to active high
+	 * to get to a defined state with the following properties:
+	 */
+	rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
+			      SER_RS485_TERMINATE_BUS |
+			      SER_RS485_RTS_AFTER_SEND);
+	rs485conf->flags |= SER_RS485_RTS_ON_SEND;
+
+	if (device_property_read_bool(dev, "rs485-rx-during-tx"))
+		rs485conf->flags |= SER_RS485_RX_DURING_TX;
+
+	if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
+		rs485conf->flags |= SER_RS485_ENABLED;
+
+	if (device_property_read_bool(dev, "rs485-rts-active-low")) {
+		rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
+		rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+	}
+
+	/*
+	 * Disabling termination by default is the safe choice:  Else if many
+	 * bus participants enable it, no communication is possible at all.
+	 * Works fine for short cables and users may enable for longer cables.
+	 */
+	desc = devm_gpiod_get_optional(dev, "rs485-term", GPIOD_OUT_LOW);
+	if (IS_ERR(desc))
+		return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-term-gpios\n");
+	port->rs485_term_gpio = desc;
+	if (port->rs485_term_gpio)
+		port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS;
+
+	dflags = (rs485conf->flags & SER_RS485_RX_DURING_TX) ?
+		 GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	desc = devm_gpiod_get_optional(dev, "rs485-rx-during-tx", dflags);
+	if (IS_ERR(desc))
+		return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-rx-during-tx-gpios\n");
+	port->rs485_rx_during_tx_gpio = desc;
+	if (port->rs485_rx_during_tx_gpio)
+		port->rs485_supported.flags |= SER_RS485_RX_DURING_TX;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
+
+/* Compile-time assertions for serial_rs485 layout */
+static_assert(offsetof(struct serial_rs485, padding) ==
+              (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32)));
+static_assert(offsetof(struct serial_rs485, padding1) ==
+	      offsetof(struct serial_rs485, padding[1]));
+static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) ==
+	      sizeof(struct serial_rs485));
+
+MODULE_DESCRIPTION("Serial driver core");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/serial_ctrl.c b/drivers/tty/serial/serial_ctrl.c
new file mode 100644
index 000000000..6fcf63442
--- /dev/null
+++ b/drivers/tty/serial/serial_ctrl.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial core controller driver
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ *
+ * This driver manages the serial core controller struct device instances.
+ * The serial core controller devices are children of the physical serial
+ * port device.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+static int serial_ctrl_probe(struct device *dev)
+{
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static int serial_ctrl_remove(struct device *dev)
+{
+	pm_runtime_disable(dev);
+
+	return 0;
+}
+
+/*
+ * Serial core controller device init functions. Note that the physical
+ * serial port device driver may not have completed probe at this point.
+ */
+int serial_ctrl_register_port(struct uart_driver *drv, struct uart_port *port)
+{
+	return serial_core_register_port(drv, port);
+}
+
+void serial_ctrl_unregister_port(struct uart_driver *drv, struct uart_port *port)
+{
+	serial_core_unregister_port(drv, port);
+}
+
+static struct device_driver serial_ctrl_driver = {
+	.name = "ctrl",
+	.suppress_bind_attrs = true,
+	.probe = serial_ctrl_probe,
+	.remove = serial_ctrl_remove,
+};
+
+int serial_base_ctrl_init(void)
+{
+	return serial_base_driver_register(&serial_ctrl_driver);
+}
+
+void serial_base_ctrl_exit(void)
+{
+	serial_base_driver_unregister(&serial_ctrl_driver);
+}
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial core controller driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
new file mode 100644
index 000000000..7d5aaa8d4
--- /dev/null
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Helpers for controlling modem lines via GPIO
+ *
+ * Copyright (C) 2014 Paratronic S.A.
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/gpio/consumer.h>
+#include <linux/termios.h>
+#include <linux/serial_core.h>
+#include <linux/module.h>
+#include <linux/property.h>
+
+#include "serial_mctrl_gpio.h"
+
+struct mctrl_gpios {
+	struct uart_port *port;
+	struct gpio_desc *gpio[UART_GPIO_MAX];
+	int irq[UART_GPIO_MAX];
+	unsigned int mctrl_prev;
+	bool mctrl_on;
+};
+
+static const struct {
+	const char *name;
+	unsigned int mctrl;
+	enum gpiod_flags flags;
+} mctrl_gpios_desc[UART_GPIO_MAX] = {
+	{ "cts", TIOCM_CTS, GPIOD_IN, },
+	{ "dsr", TIOCM_DSR, GPIOD_IN, },
+	{ "dcd", TIOCM_CD,  GPIOD_IN, },
+	{ "rng", TIOCM_RNG, GPIOD_IN, },
+	{ "rts", TIOCM_RTS, GPIOD_OUT_LOW, },
+	{ "dtr", TIOCM_DTR, GPIOD_OUT_LOW, },
+};
+
+static bool mctrl_gpio_flags_is_dir_out(unsigned int idx)
+{
+	return mctrl_gpios_desc[idx].flags & GPIOD_FLAGS_BIT_DIR_OUT;
+}
+
+/**
+ * mctrl_gpio_set - set gpios according to mctrl state
+ * @gpios: gpios to set
+ * @mctrl: state to set
+ *
+ * Set the gpios according to the mctrl state.
+ */
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+	enum mctrl_gpio_idx i;
+	struct gpio_desc *desc_array[UART_GPIO_MAX];
+	DECLARE_BITMAP(values, UART_GPIO_MAX);
+	unsigned int count = 0;
+
+	if (gpios == NULL)
+		return;
+
+	for (i = 0; i < UART_GPIO_MAX; i++)
+		if (gpios->gpio[i] && mctrl_gpio_flags_is_dir_out(i)) {
+			desc_array[count] = gpios->gpio[i];
+			__assign_bit(count, values,
+				     mctrl & mctrl_gpios_desc[i].mctrl);
+			count++;
+		}
+	gpiod_set_array_value(count, desc_array, NULL, values);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_set);
+
+/**
+ * mctrl_gpio_to_gpiod - obtain gpio_desc of modem line index
+ * @gpios: gpios to look into
+ * @gidx: index of the modem line
+ * Returns: the gpio_desc structure associated to the modem line index
+ */
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+				      enum mctrl_gpio_idx gidx)
+{
+	if (gpios == NULL)
+		return NULL;
+
+	return gpios->gpio[gidx];
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
+
+/**
+ * mctrl_gpio_get - update mctrl with the gpios values.
+ * @gpios: gpios to get the info from
+ * @mctrl: mctrl to set
+ * Returns: modified mctrl (the same value as in @mctrl)
+ *
+ * Update mctrl with the gpios values.
+ */
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+	enum mctrl_gpio_idx i;
+
+	if (gpios == NULL)
+		return *mctrl;
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		if (gpios->gpio[i] && !mctrl_gpio_flags_is_dir_out(i)) {
+			if (gpiod_get_value(gpios->gpio[i]))
+				*mctrl |= mctrl_gpios_desc[i].mctrl;
+			else
+				*mctrl &= ~mctrl_gpios_desc[i].mctrl;
+		}
+	}
+
+	return *mctrl;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_get);
+
+unsigned int
+mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+	enum mctrl_gpio_idx i;
+
+	if (gpios == NULL)
+		return *mctrl;
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		if (gpios->gpio[i] && mctrl_gpio_flags_is_dir_out(i)) {
+			if (gpiod_get_value(gpios->gpio[i]))
+				*mctrl |= mctrl_gpios_desc[i].mctrl;
+			else
+				*mctrl &= ~mctrl_gpios_desc[i].mctrl;
+		}
+	}
+
+	return *mctrl;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_get_outputs);
+
+struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
+{
+	struct mctrl_gpios *gpios;
+	enum mctrl_gpio_idx i;
+
+	gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
+	if (!gpios)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		char *gpio_str;
+		bool present;
+
+		/* Check if GPIO property exists and continue if not */
+		gpio_str = kasprintf(GFP_KERNEL, "%s-gpios",
+				     mctrl_gpios_desc[i].name);
+		if (!gpio_str)
+			continue;
+
+		present = device_property_present(dev, gpio_str);
+		kfree(gpio_str);
+		if (!present)
+			continue;
+
+		gpios->gpio[i] =
+			devm_gpiod_get_index_optional(dev,
+						      mctrl_gpios_desc[i].name,
+						      idx,
+						      mctrl_gpios_desc[i].flags);
+
+		if (IS_ERR(gpios->gpio[i]))
+			return ERR_CAST(gpios->gpio[i]);
+	}
+
+	return gpios;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_init_noauto);
+
+#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
+static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
+{
+	struct mctrl_gpios *gpios = context;
+	struct uart_port *port = gpios->port;
+	u32 mctrl = gpios->mctrl_prev;
+	u32 mctrl_diff;
+	unsigned long flags;
+
+	mctrl_gpio_get(gpios, &mctrl);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	mctrl_diff = mctrl ^ gpios->mctrl_prev;
+	gpios->mctrl_prev = mctrl;
+
+	if (mctrl_diff & MCTRL_ANY_DELTA && port->state != NULL) {
+		if ((mctrl_diff & mctrl) & TIOCM_RI)
+			port->icount.rng++;
+
+		if ((mctrl_diff & mctrl) & TIOCM_DSR)
+			port->icount.dsr++;
+
+		if (mctrl_diff & TIOCM_CD)
+			uart_handle_dcd_change(port, mctrl & TIOCM_CD);
+
+		if (mctrl_diff & TIOCM_CTS)
+			uart_handle_cts_change(port, mctrl & TIOCM_CTS);
+
+		wake_up_interruptible(&port->state->port.delta_msr_wait);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * mctrl_gpio_init - initialize uart gpios
+ * @port: port to initialize gpios for
+ * @idx: index of the gpio in the @port's device
+ *
+ * This will get the {cts,rts,...}-gpios from device tree if they are present
+ * and request them, set direction etc, and return an allocated structure.
+ * `devm_*` functions are used, so there's no need to call mctrl_gpio_free().
+ * As this sets up the irq handling, make sure to not handle changes to the
+ * gpio input lines in your driver, too.
+ */
+struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
+{
+	struct mctrl_gpios *gpios;
+	enum mctrl_gpio_idx i;
+
+	gpios = mctrl_gpio_init_noauto(port->dev, idx);
+	if (IS_ERR(gpios))
+		return gpios;
+
+	gpios->port = port;
+
+	for (i = 0; i < UART_GPIO_MAX; ++i) {
+		int ret;
+
+		if (!gpios->gpio[i] || mctrl_gpio_flags_is_dir_out(i))
+			continue;
+
+		ret = gpiod_to_irq(gpios->gpio[i]);
+		if (ret < 0) {
+			dev_err(port->dev,
+				"failed to find corresponding irq for %s (idx=%d, err=%d)\n",
+				mctrl_gpios_desc[i].name, idx, ret);
+			return ERR_PTR(ret);
+		}
+		gpios->irq[i] = ret;
+
+		/* irqs should only be enabled in .enable_ms */
+		irq_set_status_flags(gpios->irq[i], IRQ_NOAUTOEN);
+
+		ret = devm_request_irq(port->dev, gpios->irq[i],
+				       mctrl_gpio_irq_handle,
+				       IRQ_TYPE_EDGE_BOTH, dev_name(port->dev),
+				       gpios);
+		if (ret) {
+			/* alternatively implement polling */
+			dev_err(port->dev,
+				"failed to request irq for %s (idx=%d, err=%d)\n",
+				mctrl_gpios_desc[i].name, idx, ret);
+			return ERR_PTR(ret);
+		}
+	}
+
+	return gpios;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_init);
+
+/**
+ * mctrl_gpio_free - explicitly free uart gpios
+ * @dev: uart port's device
+ * @gpios: gpios structure to be freed
+ *
+ * This will free the requested gpios in mctrl_gpio_init(). As `devm_*`
+ * functions are used, there's generally no need to call this function.
+ */
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
+{
+	enum mctrl_gpio_idx i;
+
+	if (gpios == NULL)
+		return;
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		if (gpios->irq[i])
+			devm_free_irq(gpios->port->dev, gpios->irq[i], gpios);
+
+		if (gpios->gpio[i])
+			devm_gpiod_put(dev, gpios->gpio[i]);
+	}
+	devm_kfree(dev, gpios);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_free);
+
+/**
+ * mctrl_gpio_enable_ms - enable irqs and handling of changes to the ms lines
+ * @gpios: gpios to enable
+ */
+void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
+{
+	enum mctrl_gpio_idx i;
+
+	if (gpios == NULL)
+		return;
+
+	/* .enable_ms may be called multiple times */
+	if (gpios->mctrl_on)
+		return;
+
+	gpios->mctrl_on = true;
+
+	/* get initial status of modem lines GPIOs */
+	mctrl_gpio_get(gpios, &gpios->mctrl_prev);
+
+	for (i = 0; i < UART_GPIO_MAX; ++i) {
+		if (!gpios->irq[i])
+			continue;
+
+		enable_irq(gpios->irq[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms);
+
+/**
+ * mctrl_gpio_disable_ms - disable irqs and handling of changes to the ms lines
+ * @gpios: gpios to disable
+ */
+void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
+{
+	enum mctrl_gpio_idx i;
+
+	if (gpios == NULL)
+		return;
+
+	if (!gpios->mctrl_on)
+		return;
+
+	gpios->mctrl_on = false;
+
+	for (i = 0; i < UART_GPIO_MAX; ++i) {
+		if (!gpios->irq[i])
+			continue;
+
+		disable_irq(gpios->irq[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
+
+void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios)
+{
+	enum mctrl_gpio_idx i;
+
+	if (!gpios)
+		return;
+
+	if (!gpios->mctrl_on)
+		return;
+
+	for (i = 0; i < UART_GPIO_MAX; ++i) {
+		if (!gpios->irq[i])
+			continue;
+
+		enable_irq_wake(gpios->irq[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_enable_irq_wake);
+
+void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios)
+{
+	enum mctrl_gpio_idx i;
+
+	if (!gpios)
+		return;
+
+	if (!gpios->mctrl_on)
+		return;
+
+	for (i = 0; i < UART_GPIO_MAX; ++i) {
+		if (!gpios->irq[i])
+			continue;
+
+		disable_irq_wake(gpios->irq[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_disable_irq_wake);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
new file mode 100644
index 000000000..fc76910fb
--- /dev/null
+++ b/drivers/tty/serial/serial_mctrl_gpio.h
@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Helpers for controlling modem lines via GPIO
+ *
+ * Copyright (C) 2014 Paratronic S.A.
+ */
+
+#ifndef __SERIAL_MCTRL_GPIO__
+#define __SERIAL_MCTRL_GPIO__
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+
+struct uart_port;
+
+enum mctrl_gpio_idx {
+	UART_GPIO_CTS,
+	UART_GPIO_DSR,
+	UART_GPIO_DCD,
+	UART_GPIO_RNG,
+	UART_GPIO_RI = UART_GPIO_RNG,
+	UART_GPIO_RTS,
+	UART_GPIO_DTR,
+	UART_GPIO_MAX,
+};
+
+/*
+ * Opaque descriptor for modem lines controlled by GPIOs
+ */
+struct mctrl_gpios;
+
+#ifdef CONFIG_GPIOLIB
+
+/*
+ * Set state of the modem control output lines via GPIOs.
+ */
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl);
+
+/*
+ * Get state of the modem control input lines from GPIOs.
+ * The mctrl flags are updated and returned.
+ */
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl);
+
+/*
+ * Get state of the modem control output lines from GPIOs.
+ * The mctrl flags are updated and returned.
+ */
+unsigned int
+mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl);
+
+/*
+ * Returns the associated struct gpio_desc to the modem line gidx
+ */
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+				      enum mctrl_gpio_idx gidx);
+
+/*
+ * Request and set direction of modem control line GPIOs and set up irq
+ * handling.
+ * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
+ * allocation error.
+ */
+struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
+
+/*
+ * Request and set direction of modem control line GPIOs.
+ * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
+ * allocation error.
+ */
+struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
+					   unsigned int idx);
+
+/*
+ * Free the mctrl_gpios structure.
+ * Normally, this function will not be called, as the GPIOs will
+ * be disposed of by the resource management code.
+ */
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
+
+/*
+ * Enable gpio interrupts to report status line changes.
+ */
+void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
+
+/*
+ * Disable gpio interrupts to report status line changes.
+ */
+void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
+
+/*
+ * Enable gpio wakeup interrupts to enable wake up source.
+ */
+void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios);
+
+/*
+ * Disable gpio wakeup interrupts to enable wake up source.
+ */
+void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios);
+
+#else /* GPIOLIB */
+
+static inline
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+}
+
+static inline
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+	return *mctrl;
+}
+
+static inline unsigned int
+mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+	return *mctrl;
+}
+
+static inline
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+				      enum mctrl_gpio_idx gidx)
+{
+	return NULL;
+}
+
+static inline
+struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
+{
+	return NULL;
+}
+
+static inline
+struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
+{
+	return NULL;
+}
+
+static inline
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
+{
+}
+
+static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
+{
+}
+
+static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
+{
+}
+
+static inline void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios)
+{
+}
+
+static inline void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios)
+{
+}
+
+#endif /* GPIOLIB */
+
+#endif
diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c
new file mode 100644
index 000000000..862423237
--- /dev/null
+++ b/drivers/tty/serial/serial_port.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial core port device driver
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+#define SERIAL_PORT_AUTOSUSPEND_DELAY_MS	500
+
+/* Only considers pending TX for now. Caller must take care of locking */
+static int __serial_port_busy(struct uart_port *port)
+{
+	return !uart_tx_stopped(port) &&
+		uart_circ_chars_pending(&port->state->xmit);
+}
+
+static int serial_port_runtime_resume(struct device *dev)
+{
+	struct serial_port_device *port_dev = to_serial_base_port_device(dev);
+	struct uart_port *port;
+	unsigned long flags;
+
+	port = port_dev->port;
+
+	if (port->flags & UPF_DEAD)
+		goto out;
+
+	/* Flush any pending TX for the port */
+	spin_lock_irqsave(&port->lock, flags);
+	if (__serial_port_busy(port))
+		port->ops->start_tx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+out:
+	pm_runtime_mark_last_busy(dev);
+
+	return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(serial_port_pm,
+				 NULL, serial_port_runtime_resume, NULL);
+
+static int serial_port_probe(struct device *dev)
+{
+	pm_runtime_enable(dev);
+	pm_runtime_set_autosuspend_delay(dev, SERIAL_PORT_AUTOSUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(dev);
+
+	return 0;
+}
+
+static int serial_port_remove(struct device *dev)
+{
+	pm_runtime_dont_use_autosuspend(dev);
+	pm_runtime_disable(dev);
+
+	return 0;
+}
+
+/*
+ * Serial core port device init functions. Note that the physical serial
+ * port device driver may not have completed probe at this point.
+ */
+int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
+{
+	return serial_ctrl_register_port(drv, port);
+}
+EXPORT_SYMBOL(uart_add_one_port);
+
+void uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
+{
+	serial_ctrl_unregister_port(drv, port);
+}
+EXPORT_SYMBOL(uart_remove_one_port);
+
+static struct device_driver serial_port_driver = {
+	.name = "port",
+	.suppress_bind_attrs = true,
+	.probe = serial_port_probe,
+	.remove = serial_port_remove,
+	.pm = pm_ptr(&serial_port_pm),
+};
+
+int serial_base_port_init(void)
+{
+	return serial_base_driver_register(&serial_port_driver);
+}
+
+void serial_base_port_exit(void)
+{
+	serial_base_driver_unregister(&serial_port_driver);
+}
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial controller port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
new file mode 100644
index 000000000..be08fb6f7
--- /dev/null
+++ b/drivers/tty/serial/serial_txx9.c
@@ -0,0 +1,1268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Derived from many drivers using generic_serial interface,
+ * especially serial_tx3912.c by Steven J. Hill and r39xx_serial.c
+ * (was in Linux/VR tree) by Jim Pick.
+ *
+ *  Copyright (C) 1999 Harald Koerfgen
+ *  Copyright (C) 2000 Jim Pick <jim@jimpick.com>
+ *  Copyright (C) 2001 Steven J. Hill (sjhill@realitydiluted.com)
+ *  Copyright (C) 2000-2002 Toshiba Corporation
+ *
+ *  Serial driver for TX3927/TX4927/TX4925/TX4938 internal SIO controller
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#include <linux/io.h>
+
+#define PASS_LIMIT	256
+
+#if !defined(CONFIG_SERIAL_TXX9_STDSERIAL)
+/* "ttyS" is used for standard serial driver */
+#define TXX9_TTY_NAME "ttyTX"
+#define TXX9_TTY_MINOR_START	196
+#define TXX9_TTY_MAJOR	204
+#else
+/* acts like standard serial driver */
+#define TXX9_TTY_NAME "ttyS"
+#define TXX9_TTY_MINOR_START	64
+#define TXX9_TTY_MAJOR	TTY_MAJOR
+#endif
+
+/* flag aliases */
+#define UPF_TXX9_HAVE_CTS_LINE	UPF_BUGGY_UART
+#define UPF_TXX9_USE_SCLK	UPF_MAGIC_MULTIPLIER
+
+#ifdef CONFIG_PCI
+/* support for Toshiba TC86C001 SIO */
+#define ENABLE_SERIAL_TXX9_PCI
+#endif
+
+/*
+ * Number of serial ports
+ */
+#define UART_NR  CONFIG_SERIAL_TXX9_NR_UARTS
+
+#define TXX9_REGION_SIZE	0x24
+
+/* TXX9 Serial Registers */
+#define TXX9_SILCR	0x00
+#define TXX9_SIDICR	0x04
+#define TXX9_SIDISR	0x08
+#define TXX9_SICISR	0x0c
+#define TXX9_SIFCR	0x10
+#define TXX9_SIFLCR	0x14
+#define TXX9_SIBGR	0x18
+#define TXX9_SITFIFO	0x1c
+#define TXX9_SIRFIFO	0x20
+
+/* SILCR : Line Control */
+#define TXX9_SILCR_SCS_MASK	0x00000060
+#define TXX9_SILCR_SCS_IMCLK	0x00000000
+#define TXX9_SILCR_SCS_IMCLK_BG	0x00000020
+#define TXX9_SILCR_SCS_SCLK	0x00000040
+#define TXX9_SILCR_SCS_SCLK_BG	0x00000060
+#define TXX9_SILCR_UEPS	0x00000010
+#define TXX9_SILCR_UPEN	0x00000008
+#define TXX9_SILCR_USBL_MASK	0x00000004
+#define TXX9_SILCR_USBL_1BIT	0x00000000
+#define TXX9_SILCR_USBL_2BIT	0x00000004
+#define TXX9_SILCR_UMODE_MASK	0x00000003
+#define TXX9_SILCR_UMODE_8BIT	0x00000000
+#define TXX9_SILCR_UMODE_7BIT	0x00000001
+
+/* SIDICR : DMA/Int. Control */
+#define TXX9_SIDICR_TDE	0x00008000
+#define TXX9_SIDICR_RDE	0x00004000
+#define TXX9_SIDICR_TIE	0x00002000
+#define TXX9_SIDICR_RIE	0x00001000
+#define TXX9_SIDICR_SPIE	0x00000800
+#define TXX9_SIDICR_CTSAC	0x00000600
+#define TXX9_SIDICR_STIE_MASK	0x0000003f
+#define TXX9_SIDICR_STIE_OERS		0x00000020
+#define TXX9_SIDICR_STIE_CTSS		0x00000010
+#define TXX9_SIDICR_STIE_RBRKD	0x00000008
+#define TXX9_SIDICR_STIE_TRDY		0x00000004
+#define TXX9_SIDICR_STIE_TXALS	0x00000002
+#define TXX9_SIDICR_STIE_UBRKD	0x00000001
+
+/* SIDISR : DMA/Int. Status */
+#define TXX9_SIDISR_UBRK	0x00008000
+#define TXX9_SIDISR_UVALID	0x00004000
+#define TXX9_SIDISR_UFER	0x00002000
+#define TXX9_SIDISR_UPER	0x00001000
+#define TXX9_SIDISR_UOER	0x00000800
+#define TXX9_SIDISR_ERI	0x00000400
+#define TXX9_SIDISR_TOUT	0x00000200
+#define TXX9_SIDISR_TDIS	0x00000100
+#define TXX9_SIDISR_RDIS	0x00000080
+#define TXX9_SIDISR_STIS	0x00000040
+#define TXX9_SIDISR_RFDN_MASK	0x0000001f
+
+/* SICISR : Change Int. Status */
+#define TXX9_SICISR_OERS	0x00000020
+#define TXX9_SICISR_CTSS	0x00000010
+#define TXX9_SICISR_RBRKD	0x00000008
+#define TXX9_SICISR_TRDY	0x00000004
+#define TXX9_SICISR_TXALS	0x00000002
+#define TXX9_SICISR_UBRKD	0x00000001
+
+/* SIFCR : FIFO Control */
+#define TXX9_SIFCR_SWRST	0x00008000
+#define TXX9_SIFCR_RDIL_MASK	0x00000180
+#define TXX9_SIFCR_RDIL_1	0x00000000
+#define TXX9_SIFCR_RDIL_4	0x00000080
+#define TXX9_SIFCR_RDIL_8	0x00000100
+#define TXX9_SIFCR_RDIL_12	0x00000180
+#define TXX9_SIFCR_RDIL_MAX	0x00000180
+#define TXX9_SIFCR_TDIL_MASK	0x00000018
+#define TXX9_SIFCR_TDIL_1	0x00000000
+#define TXX9_SIFCR_TDIL_4	0x00000001
+#define TXX9_SIFCR_TDIL_8	0x00000010
+#define TXX9_SIFCR_TDIL_MAX	0x00000010
+#define TXX9_SIFCR_TFRST	0x00000004
+#define TXX9_SIFCR_RFRST	0x00000002
+#define TXX9_SIFCR_FRSTE	0x00000001
+#define TXX9_SIO_TX_FIFO	8
+#define TXX9_SIO_RX_FIFO	16
+
+/* SIFLCR : Flow Control */
+#define TXX9_SIFLCR_RCS	0x00001000
+#define TXX9_SIFLCR_TES	0x00000800
+#define TXX9_SIFLCR_RTSSC	0x00000200
+#define TXX9_SIFLCR_RSDE	0x00000100
+#define TXX9_SIFLCR_TSDE	0x00000080
+#define TXX9_SIFLCR_RTSTL_MASK	0x0000001e
+#define TXX9_SIFLCR_RTSTL_MAX	0x0000001e
+#define TXX9_SIFLCR_TBRK	0x00000001
+
+/* SIBGR : Baudrate Control */
+#define TXX9_SIBGR_BCLK_MASK	0x00000300
+#define TXX9_SIBGR_BCLK_T0	0x00000000
+#define TXX9_SIBGR_BCLK_T2	0x00000100
+#define TXX9_SIBGR_BCLK_T4	0x00000200
+#define TXX9_SIBGR_BCLK_T6	0x00000300
+#define TXX9_SIBGR_BRD_MASK	0x000000ff
+
+static inline unsigned int sio_in(struct uart_port *up, int offset)
+{
+	switch (up->iotype) {
+	default:
+		return __raw_readl(up->membase + offset);
+	case UPIO_PORT:
+		return inl(up->iobase + offset);
+	}
+}
+
+static inline void
+sio_out(struct uart_port *up, int offset, int value)
+{
+	switch (up->iotype) {
+	default:
+		__raw_writel(value, up->membase + offset);
+		break;
+	case UPIO_PORT:
+		outl(value, up->iobase + offset);
+		break;
+	}
+}
+
+static inline void
+sio_mask(struct uart_port *up, int offset, unsigned int value)
+{
+	sio_out(up, offset, sio_in(up, offset) & ~value);
+}
+static inline void
+sio_set(struct uart_port *up, int offset, unsigned int value)
+{
+	sio_out(up, offset, sio_in(up, offset) | value);
+}
+
+static inline void
+sio_quot_set(struct uart_port *up, int quot)
+{
+	quot >>= 1;
+	if (quot < 256)
+		sio_out(up, TXX9_SIBGR, quot | TXX9_SIBGR_BCLK_T0);
+	else if (quot < (256 << 2))
+		sio_out(up, TXX9_SIBGR, (quot >> 2) | TXX9_SIBGR_BCLK_T2);
+	else if (quot < (256 << 4))
+		sio_out(up, TXX9_SIBGR, (quot >> 4) | TXX9_SIBGR_BCLK_T4);
+	else if (quot < (256 << 6))
+		sio_out(up, TXX9_SIBGR, (quot >> 6) | TXX9_SIBGR_BCLK_T6);
+	else
+		sio_out(up, TXX9_SIBGR, 0xff | TXX9_SIBGR_BCLK_T6);
+}
+
+static void serial_txx9_stop_tx(struct uart_port *up)
+{
+	sio_mask(up, TXX9_SIDICR, TXX9_SIDICR_TIE);
+}
+
+static void serial_txx9_start_tx(struct uart_port *up)
+{
+	sio_set(up, TXX9_SIDICR, TXX9_SIDICR_TIE);
+}
+
+static void serial_txx9_stop_rx(struct uart_port *up)
+{
+	up->read_status_mask &= ~TXX9_SIDISR_RDIS;
+}
+
+static void serial_txx9_initialize(struct uart_port *up)
+{
+	unsigned int tmout = 10000;
+
+	sio_out(up, TXX9_SIFCR, TXX9_SIFCR_SWRST);
+	/* TX4925 BUG WORKAROUND.  Accessing SIOC register
+	 * immediately after soft reset causes bus error. */
+	udelay(1);
+	while ((sio_in(up, TXX9_SIFCR) & TXX9_SIFCR_SWRST) && --tmout)
+		udelay(1);
+	/* TX Int by FIFO Empty, RX Int by Receiving 1 char. */
+	sio_set(up, TXX9_SIFCR,
+		TXX9_SIFCR_TDIL_MAX | TXX9_SIFCR_RDIL_1);
+	/* initial settings */
+	sio_out(up, TXX9_SILCR,
+		TXX9_SILCR_UMODE_8BIT | TXX9_SILCR_USBL_1BIT |
+		((up->flags & UPF_TXX9_USE_SCLK) ?
+		 TXX9_SILCR_SCS_SCLK_BG : TXX9_SILCR_SCS_IMCLK_BG));
+	sio_quot_set(up, uart_get_divisor(up, 9600));
+	sio_out(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSTL_MAX /* 15 */);
+	sio_out(up, TXX9_SIDICR, 0);
+}
+
+static inline void
+receive_chars(struct uart_port *up, unsigned int *status)
+{
+	unsigned int disr = *status;
+	int max_count = 256;
+	unsigned int next_ignore_status_mask;
+	u8 ch, flag;
+
+	do {
+		ch = sio_in(up, TXX9_SIRFIFO);
+		flag = TTY_NORMAL;
+		up->icount.rx++;
+
+		/* mask out RFDN_MASK bit added by previous overrun */
+		next_ignore_status_mask =
+			up->ignore_status_mask & ~TXX9_SIDISR_RFDN_MASK;
+		if (unlikely(disr & (TXX9_SIDISR_UBRK | TXX9_SIDISR_UPER |
+				     TXX9_SIDISR_UFER | TXX9_SIDISR_UOER))) {
+			/*
+			 * For statistics only
+			 */
+			if (disr & TXX9_SIDISR_UBRK) {
+				disr &= ~(TXX9_SIDISR_UFER | TXX9_SIDISR_UPER);
+				up->icount.brk++;
+				/*
+				 * We do the SysRQ and SAK checking
+				 * here because otherwise the break
+				 * may get masked by ignore_status_mask
+				 * or read_status_mask.
+				 */
+				if (uart_handle_break(up))
+					goto ignore_char;
+			} else if (disr & TXX9_SIDISR_UPER)
+				up->icount.parity++;
+			else if (disr & TXX9_SIDISR_UFER)
+				up->icount.frame++;
+			if (disr & TXX9_SIDISR_UOER) {
+				up->icount.overrun++;
+				/*
+				 * The receiver read buffer still hold
+				 * a char which caused overrun.
+				 * Ignore next char by adding RFDN_MASK
+				 * to ignore_status_mask temporarily.
+				 */
+				next_ignore_status_mask |=
+					TXX9_SIDISR_RFDN_MASK;
+			}
+
+			/*
+			 * Mask off conditions which should be ingored.
+			 */
+			disr &= up->read_status_mask;
+
+			if (disr & TXX9_SIDISR_UBRK) {
+				flag = TTY_BREAK;
+			} else if (disr & TXX9_SIDISR_UPER)
+				flag = TTY_PARITY;
+			else if (disr & TXX9_SIDISR_UFER)
+				flag = TTY_FRAME;
+		}
+		if (uart_handle_sysrq_char(up, ch))
+			goto ignore_char;
+
+		uart_insert_char(up, disr, TXX9_SIDISR_UOER, ch, flag);
+
+	ignore_char:
+		up->ignore_status_mask = next_ignore_status_mask;
+		disr = sio_in(up, TXX9_SIDISR);
+	} while (!(disr & TXX9_SIDISR_UVALID) && (max_count-- > 0));
+
+	tty_flip_buffer_push(&up->state->port);
+
+	*status = disr;
+}
+
+static inline void transmit_chars(struct uart_port *up)
+{
+	u8 ch;
+
+	uart_port_tx_limited(up, ch, TXX9_SIO_TX_FIFO,
+		true,
+		sio_out(up, TXX9_SITFIFO, ch),
+		({}));
+}
+
+static irqreturn_t serial_txx9_interrupt(int irq, void *dev_id)
+{
+	int pass_counter = 0;
+	struct uart_port *up = dev_id;
+	unsigned int status;
+
+	while (1) {
+		spin_lock(&up->lock);
+		status = sio_in(up, TXX9_SIDISR);
+		if (!(sio_in(up, TXX9_SIDICR) & TXX9_SIDICR_TIE))
+			status &= ~TXX9_SIDISR_TDIS;
+		if (!(status & (TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS |
+				TXX9_SIDISR_TOUT))) {
+			spin_unlock(&up->lock);
+			break;
+		}
+
+		if (status & TXX9_SIDISR_RDIS)
+			receive_chars(up, &status);
+		if (status & TXX9_SIDISR_TDIS)
+			transmit_chars(up);
+		/* Clear TX/RX Int. Status */
+		sio_mask(up, TXX9_SIDISR,
+			 TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS |
+			 TXX9_SIDISR_TOUT);
+		spin_unlock(&up->lock);
+
+		if (pass_counter++ > PASS_LIMIT)
+			break;
+	}
+
+	return pass_counter ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static unsigned int serial_txx9_tx_empty(struct uart_port *up)
+{
+	unsigned long flags;
+	unsigned int ret;
+
+	spin_lock_irqsave(&up->lock, flags);
+	ret = (sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS) ? TIOCSER_TEMT : 0;
+	spin_unlock_irqrestore(&up->lock, flags);
+
+	return ret;
+}
+
+static unsigned int serial_txx9_get_mctrl(struct uart_port *up)
+{
+	unsigned int ret;
+
+	/* no modem control lines */
+	ret = TIOCM_CAR | TIOCM_DSR;
+	ret |= (sio_in(up, TXX9_SIFLCR) & TXX9_SIFLCR_RTSSC) ? 0 : TIOCM_RTS;
+	ret |= (sio_in(up, TXX9_SICISR) & TXX9_SICISR_CTSS) ? 0 : TIOCM_CTS;
+
+	return ret;
+}
+
+static void serial_txx9_set_mctrl(struct uart_port *up, unsigned int mctrl)
+{
+
+	if (mctrl & TIOCM_RTS)
+		sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSSC);
+	else
+		sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSSC);
+}
+
+static void serial_txx9_break_ctl(struct uart_port *up, int break_state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->lock, flags);
+	if (break_state == -1)
+		sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
+	else
+		sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
+	spin_unlock_irqrestore(&up->lock, flags);
+}
+
+#if defined(CONFIG_SERIAL_TXX9_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_port *up)
+{
+	unsigned int tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	while (--tmout &&
+	       !(sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS))
+		udelay(1);
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		while (--tmout &&
+		       (sio_in(up, TXX9_SICISR) & TXX9_SICISR_CTSS))
+			udelay(1);
+	}
+}
+#endif
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial_txx9_get_poll_char(struct uart_port *up)
+{
+	unsigned int ier;
+	unsigned char c;
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = sio_in(up, TXX9_SIDICR);
+	sio_out(up, TXX9_SIDICR, 0);
+
+	while (sio_in(up, TXX9_SIDISR) & TXX9_SIDISR_UVALID)
+		;
+
+	c = sio_in(up, TXX9_SIRFIFO);
+
+	/*
+	 *	Finally, clear RX interrupt status
+	 *	and restore the IER
+	 */
+	sio_mask(up, TXX9_SIDISR, TXX9_SIDISR_RDIS);
+	sio_out(up, TXX9_SIDICR, ier);
+	return c;
+}
+
+
+static void serial_txx9_put_poll_char(struct uart_port *up, unsigned char c)
+{
+	unsigned int ier;
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = sio_in(up, TXX9_SIDICR);
+	sio_out(up, TXX9_SIDICR, 0);
+
+	wait_for_xmitr(up);
+	/*
+	 *	Send the character out.
+	 */
+	sio_out(up, TXX9_SITFIFO, c);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up);
+	sio_out(up, TXX9_SIDICR, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static int serial_txx9_startup(struct uart_port *up)
+{
+	unsigned long flags;
+	int retval;
+
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	sio_set(up, TXX9_SIFCR,
+		TXX9_SIFCR_TFRST | TXX9_SIFCR_RFRST | TXX9_SIFCR_FRSTE);
+	/* clear reset */
+	sio_mask(up, TXX9_SIFCR,
+		 TXX9_SIFCR_TFRST | TXX9_SIFCR_RFRST | TXX9_SIFCR_FRSTE);
+	sio_out(up, TXX9_SIDICR, 0);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	sio_out(up, TXX9_SIDISR, 0);
+
+	retval = request_irq(up->irq, serial_txx9_interrupt,
+			     IRQF_SHARED, "serial_txx9", up);
+	if (retval)
+		return retval;
+
+	/*
+	 * Now, initialize the UART
+	 */
+	spin_lock_irqsave(&up->lock, flags);
+	serial_txx9_set_mctrl(up, up->mctrl);
+	spin_unlock_irqrestore(&up->lock, flags);
+
+	/* Enable RX/TX */
+	sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RSDE | TXX9_SIFLCR_TSDE);
+
+	/*
+	 * Finally, enable interrupts.
+	 */
+	sio_set(up, TXX9_SIDICR, TXX9_SIDICR_RIE);
+
+	return 0;
+}
+
+static void serial_txx9_shutdown(struct uart_port *up)
+{
+	unsigned long flags;
+
+	/*
+	 * Disable interrupts from this port
+	 */
+	sio_out(up, TXX9_SIDICR, 0);	/* disable all intrs */
+
+	spin_lock_irqsave(&up->lock, flags);
+	serial_txx9_set_mctrl(up, up->mctrl);
+	spin_unlock_irqrestore(&up->lock, flags);
+
+	/*
+	 * Disable break condition
+	 */
+	sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
+
+#ifdef CONFIG_SERIAL_TXX9_CONSOLE
+	if (up->cons && up->line == up->cons->index) {
+		free_irq(up->irq, up);
+		return;
+	}
+#endif
+	/* reset FIFOs */
+	sio_set(up, TXX9_SIFCR,
+		TXX9_SIFCR_TFRST | TXX9_SIFCR_RFRST | TXX9_SIFCR_FRSTE);
+	/* clear reset */
+	sio_mask(up, TXX9_SIFCR,
+		 TXX9_SIFCR_TFRST | TXX9_SIFCR_RFRST | TXX9_SIFCR_FRSTE);
+
+	/* Disable RX/TX */
+	sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_RSDE | TXX9_SIFLCR_TSDE);
+
+	free_irq(up->irq, up);
+}
+
+static void
+serial_txx9_set_termios(struct uart_port *up, struct ktermios *termios,
+			const struct ktermios *old)
+{
+	unsigned int cval, fcr = 0;
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	/*
+	 * We don't support modem control lines.
+	 */
+	termios->c_cflag &= ~(HUPCL | CMSPAR);
+	termios->c_cflag |= CLOCAL;
+
+	cval = sio_in(up, TXX9_SILCR);
+	/* byte size and parity */
+	cval &= ~TXX9_SILCR_UMODE_MASK;
+	switch (termios->c_cflag & CSIZE) {
+	case CS7:
+		cval |= TXX9_SILCR_UMODE_7BIT;
+		break;
+	default:
+	case CS5:	/* not supported */
+	case CS6:	/* not supported */
+	case CS8:
+		cval |= TXX9_SILCR_UMODE_8BIT;
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+		break;
+	}
+
+	cval &= ~TXX9_SILCR_USBL_MASK;
+	if (termios->c_cflag & CSTOPB)
+		cval |= TXX9_SILCR_USBL_2BIT;
+	else
+		cval |= TXX9_SILCR_USBL_1BIT;
+	cval &= ~(TXX9_SILCR_UPEN | TXX9_SILCR_UEPS);
+	if (termios->c_cflag & PARENB)
+		cval |= TXX9_SILCR_UPEN;
+	if (!(termios->c_cflag & PARODD))
+		cval |= TXX9_SILCR_UEPS;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(up, termios, old, 0, up->uartclk/16/2);
+	quot = uart_get_divisor(up, baud);
+
+	/* Set up FIFOs */
+	/* TX Int by FIFO Empty, RX Int by Receiving 1 char. */
+	fcr = TXX9_SIFCR_TDIL_MAX | TXX9_SIFCR_RDIL_1;
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(up, termios->c_cflag, baud);
+
+	up->read_status_mask = TXX9_SIDISR_UOER |
+		TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS;
+	if (termios->c_iflag & INPCK)
+		up->read_status_mask |= TXX9_SIDISR_UFER | TXX9_SIDISR_UPER;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		up->read_status_mask |= TXX9_SIDISR_UBRK;
+
+	/*
+	 * Characteres to ignore
+	 */
+	up->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->ignore_status_mask |= TXX9_SIDISR_UPER | TXX9_SIDISR_UFER;
+	if (termios->c_iflag & IGNBRK) {
+		up->ignore_status_mask |= TXX9_SIDISR_UBRK;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->ignore_status_mask |= TXX9_SIDISR_UOER;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->ignore_status_mask |= TXX9_SIDISR_RDIS;
+
+	/* CTS flow control flag */
+	if ((termios->c_cflag & CRTSCTS) &&
+	    (up->flags & UPF_TXX9_HAVE_CTS_LINE)) {
+		sio_set(up, TXX9_SIFLCR,
+			TXX9_SIFLCR_RCS | TXX9_SIFLCR_TES);
+	} else {
+		sio_mask(up, TXX9_SIFLCR,
+			 TXX9_SIFLCR_RCS | TXX9_SIFLCR_TES);
+	}
+
+	sio_out(up, TXX9_SILCR, cval);
+	sio_quot_set(up, quot);
+	sio_out(up, TXX9_SIFCR, fcr);
+
+	serial_txx9_set_mctrl(up, up->mctrl);
+	spin_unlock_irqrestore(&up->lock, flags);
+}
+
+static void
+serial_txx9_pm(struct uart_port *port, unsigned int state,
+	      unsigned int oldstate)
+{
+	/*
+	 * If oldstate was -1 this is called from
+	 * uart_configure_port().  In this case do not initialize the
+	 * port now, because the port was already initialized (for
+	 * non-console port) or should not be initialized here (for
+	 * console port).  If we initialized the port here we lose
+	 * serial console settings.
+	 */
+	if (state == 0 && oldstate != -1)
+		serial_txx9_initialize(port);
+}
+
+static int serial_txx9_request_resource(struct uart_port *up)
+{
+	unsigned int size = TXX9_REGION_SIZE;
+	int ret = 0;
+
+	switch (up->iotype) {
+	default:
+		if (!up->mapbase)
+			break;
+
+		if (!request_mem_region(up->mapbase, size, "serial_txx9")) {
+			ret = -EBUSY;
+			break;
+		}
+
+		if (up->flags & UPF_IOREMAP) {
+			up->membase = ioremap(up->mapbase, size);
+			if (!up->membase) {
+				release_mem_region(up->mapbase, size);
+				ret = -ENOMEM;
+			}
+		}
+		break;
+
+	case UPIO_PORT:
+		if (!request_region(up->iobase, size, "serial_txx9"))
+			ret = -EBUSY;
+		break;
+	}
+	return ret;
+}
+
+static void serial_txx9_release_resource(struct uart_port *up)
+{
+	unsigned int size = TXX9_REGION_SIZE;
+
+	switch (up->iotype) {
+	default:
+		if (!up->mapbase)
+			break;
+
+		if (up->flags & UPF_IOREMAP) {
+			iounmap(up->membase);
+			up->membase = NULL;
+		}
+
+		release_mem_region(up->mapbase, size);
+		break;
+
+	case UPIO_PORT:
+		release_region(up->iobase, size);
+		break;
+	}
+}
+
+static void serial_txx9_release_port(struct uart_port *up)
+{
+	serial_txx9_release_resource(up);
+}
+
+static int serial_txx9_request_port(struct uart_port *up)
+{
+	return serial_txx9_request_resource(up);
+}
+
+static void serial_txx9_config_port(struct uart_port *up, int uflags)
+{
+	int ret;
+
+	/*
+	 * Find the region that we can probe for.  This in turn
+	 * tells us whether we can probe for the type of port.
+	 */
+	ret = serial_txx9_request_resource(up);
+	if (ret < 0)
+		return;
+	up->type = PORT_TXX9;
+	up->fifosize = TXX9_SIO_TX_FIFO;
+
+#ifdef CONFIG_SERIAL_TXX9_CONSOLE
+	if (up->line == up->cons->index)
+		return;
+#endif
+	serial_txx9_initialize(up);
+}
+
+static const char *
+serial_txx9_type(struct uart_port *port)
+{
+	return "txx9";
+}
+
+static const struct uart_ops serial_txx9_pops = {
+	.tx_empty	= serial_txx9_tx_empty,
+	.set_mctrl	= serial_txx9_set_mctrl,
+	.get_mctrl	= serial_txx9_get_mctrl,
+	.stop_tx	= serial_txx9_stop_tx,
+	.start_tx	= serial_txx9_start_tx,
+	.stop_rx	= serial_txx9_stop_rx,
+	.break_ctl	= serial_txx9_break_ctl,
+	.startup	= serial_txx9_startup,
+	.shutdown	= serial_txx9_shutdown,
+	.set_termios	= serial_txx9_set_termios,
+	.pm		= serial_txx9_pm,
+	.type		= serial_txx9_type,
+	.release_port	= serial_txx9_release_port,
+	.request_port	= serial_txx9_request_port,
+	.config_port	= serial_txx9_config_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= serial_txx9_get_poll_char,
+	.poll_put_char	= serial_txx9_put_poll_char,
+#endif
+};
+
+static struct uart_port serial_txx9_ports[UART_NR];
+
+static void __init serial_txx9_register_ports(struct uart_driver *drv,
+					      struct device *dev)
+{
+	int i;
+
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_port *up = &serial_txx9_ports[i];
+
+		up->line = i;
+		up->ops = &serial_txx9_pops;
+		up->dev = dev;
+		if (up->iobase || up->mapbase)
+			uart_add_one_port(drv, up);
+	}
+}
+
+#ifdef CONFIG_SERIAL_TXX9_CONSOLE
+
+static void serial_txx9_console_putchar(struct uart_port *up, unsigned char ch)
+{
+	wait_for_xmitr(up);
+	sio_out(up, TXX9_SITFIFO, ch);
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ */
+static void
+serial_txx9_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_port *up = &serial_txx9_ports[co->index];
+	unsigned int ier, flcr;
+
+	/*
+	 *	First save the UER then disable the interrupts
+	 */
+	ier = sio_in(up, TXX9_SIDICR);
+	sio_out(up, TXX9_SIDICR, 0);
+	/*
+	 *	Disable flow-control if enabled (and unnecessary)
+	 */
+	flcr = sio_in(up, TXX9_SIFLCR);
+	if (!(up->flags & UPF_CONS_FLOW) && (flcr & TXX9_SIFLCR_TES))
+		sio_out(up, TXX9_SIFLCR, flcr & ~TXX9_SIFLCR_TES);
+
+	uart_console_write(up, s, count, serial_txx9_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up);
+	sio_out(up, TXX9_SIFLCR, flcr);
+	sio_out(up, TXX9_SIDICR, ier);
+}
+
+static int __init serial_txx9_console_setup(struct console *co, char *options)
+{
+	struct uart_port *up;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= UART_NR)
+		co->index = 0;
+	up = &serial_txx9_ports[co->index];
+	if (!up->ops)
+		return -ENODEV;
+
+	serial_txx9_initialize(up);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(up, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver serial_txx9_reg;
+static struct console serial_txx9_console = {
+	.name		= TXX9_TTY_NAME,
+	.write		= serial_txx9_console_write,
+	.device		= uart_console_device,
+	.setup		= serial_txx9_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial_txx9_reg,
+};
+
+static int __init serial_txx9_console_init(void)
+{
+	register_console(&serial_txx9_console);
+	return 0;
+}
+console_initcall(serial_txx9_console_init);
+
+#define SERIAL_TXX9_CONSOLE	&serial_txx9_console
+#else
+#define SERIAL_TXX9_CONSOLE	NULL
+#endif
+
+static struct uart_driver serial_txx9_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "serial_txx9",
+	.dev_name		= TXX9_TTY_NAME,
+	.major			= TXX9_TTY_MAJOR,
+	.minor			= TXX9_TTY_MINOR_START,
+	.nr			= UART_NR,
+	.cons			= SERIAL_TXX9_CONSOLE,
+};
+
+int __init early_serial_txx9_setup(struct uart_port *port)
+{
+	if (port->line >= ARRAY_SIZE(serial_txx9_ports))
+		return -ENODEV;
+
+	serial_txx9_ports[port->line] = *port;
+	serial_txx9_ports[port->line].ops = &serial_txx9_pops;
+	serial_txx9_ports[port->line].flags |=
+		UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
+	return 0;
+}
+
+static DEFINE_MUTEX(serial_txx9_mutex);
+
+/**
+ *	serial_txx9_register_port - register a serial port
+ *	@port: serial port template
+ *
+ *	Configure the serial port specified by the request.
+ *
+ *	The port is then probed and if necessary the IRQ is autodetected
+ *	If this fails an error is returned.
+ *
+ *	On success the port is ready to use and the line number is returned.
+ */
+static int serial_txx9_register_port(struct uart_port *port)
+{
+	int i;
+	struct uart_port *uart;
+	int ret = -ENOSPC;
+
+	mutex_lock(&serial_txx9_mutex);
+	for (i = 0; i < UART_NR; i++) {
+		uart = &serial_txx9_ports[i];
+		if (uart_match_port(uart, port)) {
+			uart_remove_one_port(&serial_txx9_reg, uart);
+			break;
+		}
+	}
+	if (i == UART_NR) {
+		/* Find unused port */
+		for (i = 0; i < UART_NR; i++) {
+			uart = &serial_txx9_ports[i];
+			if (!(uart->iobase || uart->mapbase))
+				break;
+		}
+	}
+	if (i < UART_NR) {
+		uart->iobase = port->iobase;
+		uart->membase = port->membase;
+		uart->irq      = port->irq;
+		uart->uartclk  = port->uartclk;
+		uart->iotype   = port->iotype;
+		uart->flags    = port->flags
+			| UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
+		uart->mapbase  = port->mapbase;
+		if (port->dev)
+			uart->dev = port->dev;
+		ret = uart_add_one_port(&serial_txx9_reg, uart);
+		if (ret == 0)
+			ret = uart->line;
+	}
+	mutex_unlock(&serial_txx9_mutex);
+	return ret;
+}
+
+/**
+ *	serial_txx9_unregister_port - remove a txx9 serial port at runtime
+ *	@line: serial line number
+ *
+ *	Remove one serial port.  This may not be called from interrupt
+ *	context.  We hand the port back to the our control.
+ */
+static void serial_txx9_unregister_port(int line)
+{
+	struct uart_port *uart = &serial_txx9_ports[line];
+
+	mutex_lock(&serial_txx9_mutex);
+	uart_remove_one_port(&serial_txx9_reg, uart);
+	uart->flags = 0;
+	uart->type = PORT_UNKNOWN;
+	uart->iobase = 0;
+	uart->mapbase = 0;
+	uart->membase = NULL;
+	uart->dev = NULL;
+	mutex_unlock(&serial_txx9_mutex);
+}
+
+/*
+ * Register a set of serial devices attached to a platform device.
+ */
+static int serial_txx9_probe(struct platform_device *dev)
+{
+	struct uart_port *p = dev_get_platdata(&dev->dev);
+	struct uart_port port;
+	int ret, i;
+
+	memset(&port, 0, sizeof(struct uart_port));
+	for (i = 0; p && p->uartclk != 0; p++, i++) {
+		port.iobase	= p->iobase;
+		port.membase	= p->membase;
+		port.irq	= p->irq;
+		port.uartclk	= p->uartclk;
+		port.iotype	= p->iotype;
+		port.flags	= p->flags;
+		port.mapbase	= p->mapbase;
+		port.dev	= &dev->dev;
+		port.has_sysrq	= IS_ENABLED(CONFIG_SERIAL_TXX9_CONSOLE);
+		ret = serial_txx9_register_port(&port);
+		if (ret < 0) {
+			dev_err(&dev->dev, "unable to register port at index %d "
+				"(IO%lx MEM%llx IRQ%d): %d\n", i,
+				p->iobase, (unsigned long long)p->mapbase,
+				p->irq, ret);
+		}
+	}
+	return 0;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int serial_txx9_remove(struct platform_device *dev)
+{
+	int i;
+
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_port *up = &serial_txx9_ports[i];
+
+		if (up->dev == &dev->dev)
+			serial_txx9_unregister_port(i);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int serial_txx9_suspend(struct platform_device *dev, pm_message_t state)
+{
+	int i;
+
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_port *up = &serial_txx9_ports[i];
+
+		if (up->type != PORT_UNKNOWN && up->dev == &dev->dev)
+			uart_suspend_port(&serial_txx9_reg, up);
+	}
+
+	return 0;
+}
+
+static int serial_txx9_resume(struct platform_device *dev)
+{
+	int i;
+
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_port *up = &serial_txx9_ports[i];
+
+		if (up->type != PORT_UNKNOWN && up->dev == &dev->dev)
+			uart_resume_port(&serial_txx9_reg, up);
+	}
+
+	return 0;
+}
+#endif
+
+static struct platform_driver serial_txx9_plat_driver = {
+	.probe		= serial_txx9_probe,
+	.remove		= serial_txx9_remove,
+#ifdef CONFIG_PM
+	.suspend	= serial_txx9_suspend,
+	.resume		= serial_txx9_resume,
+#endif
+	.driver		= {
+		.name	= "serial_txx9",
+	},
+};
+
+#ifdef ENABLE_SERIAL_TXX9_PCI
+/*
+ * Probe one serial board.  Unfortunately, there is no rhyme nor reason
+ * to the arrangement of serial ports on a PCI card.
+ */
+static int
+pciserial_txx9_init_one(struct pci_dev *dev, const struct pci_device_id *ent)
+{
+	struct uart_port port;
+	int line;
+	int rc;
+
+	rc = pci_enable_device(dev);
+	if (rc)
+		return rc;
+
+	memset(&port, 0, sizeof(port));
+	port.ops = &serial_txx9_pops;
+	port.flags |= UPF_TXX9_HAVE_CTS_LINE;
+	port.uartclk = 66670000;
+	port.irq = dev->irq;
+	port.iotype = UPIO_PORT;
+	port.iobase = pci_resource_start(dev, 1);
+	port.dev = &dev->dev;
+	line = serial_txx9_register_port(&port);
+	if (line < 0) {
+		printk(KERN_WARNING "Couldn't register serial port %s: %d\n", pci_name(dev), line);
+		pci_disable_device(dev);
+		return line;
+	}
+	pci_set_drvdata(dev, &serial_txx9_ports[line]);
+
+	return 0;
+}
+
+static void pciserial_txx9_remove_one(struct pci_dev *dev)
+{
+	struct uart_port *up = pci_get_drvdata(dev);
+
+	if (up) {
+		serial_txx9_unregister_port(up->line);
+		pci_disable_device(dev);
+	}
+}
+
+#ifdef CONFIG_PM
+static int pciserial_txx9_suspend_one(struct pci_dev *dev, pm_message_t state)
+{
+	struct uart_port *up = pci_get_drvdata(dev);
+
+	if (up)
+		uart_suspend_port(&serial_txx9_reg, up);
+	pci_save_state(dev);
+	pci_set_power_state(dev, pci_choose_state(dev, state));
+	return 0;
+}
+
+static int pciserial_txx9_resume_one(struct pci_dev *dev)
+{
+	struct uart_port *up = pci_get_drvdata(dev);
+
+	pci_set_power_state(dev, PCI_D0);
+	pci_restore_state(dev);
+	if (up)
+		uart_resume_port(&serial_txx9_reg, up);
+	return 0;
+}
+#endif
+
+static const struct pci_device_id serial_txx9_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_TC86C001_MISC) },
+	{ 0, }
+};
+
+static struct pci_driver serial_txx9_pci_driver = {
+	.name		= "serial_txx9",
+	.probe		= pciserial_txx9_init_one,
+	.remove		= pciserial_txx9_remove_one,
+#ifdef CONFIG_PM
+	.suspend	= pciserial_txx9_suspend_one,
+	.resume		= pciserial_txx9_resume_one,
+#endif
+	.id_table	= serial_txx9_pci_tbl,
+};
+
+MODULE_DEVICE_TABLE(pci, serial_txx9_pci_tbl);
+#endif /* ENABLE_SERIAL_TXX9_PCI */
+
+static struct platform_device *serial_txx9_plat_devs;
+
+static int __init serial_txx9_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&serial_txx9_reg);
+	if (ret)
+		goto out;
+
+	serial_txx9_plat_devs = platform_device_alloc("serial_txx9", -1);
+	if (!serial_txx9_plat_devs) {
+		ret = -ENOMEM;
+		goto unreg_uart_drv;
+	}
+
+	ret = platform_device_add(serial_txx9_plat_devs);
+	if (ret)
+		goto put_dev;
+
+	serial_txx9_register_ports(&serial_txx9_reg,
+				   &serial_txx9_plat_devs->dev);
+
+	ret = platform_driver_register(&serial_txx9_plat_driver);
+	if (ret)
+		goto del_dev;
+
+#ifdef ENABLE_SERIAL_TXX9_PCI
+	ret = pci_register_driver(&serial_txx9_pci_driver);
+	if (ret) {
+		platform_driver_unregister(&serial_txx9_plat_driver);
+	}
+#endif
+	if (ret == 0)
+		goto out;
+
+ del_dev:
+	platform_device_del(serial_txx9_plat_devs);
+ put_dev:
+	platform_device_put(serial_txx9_plat_devs);
+ unreg_uart_drv:
+	uart_unregister_driver(&serial_txx9_reg);
+ out:
+	return ret;
+}
+
+static void __exit serial_txx9_exit(void)
+{
+	int i;
+
+#ifdef ENABLE_SERIAL_TXX9_PCI
+	pci_unregister_driver(&serial_txx9_pci_driver);
+#endif
+	platform_driver_unregister(&serial_txx9_plat_driver);
+	platform_device_unregister(serial_txx9_plat_devs);
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_port *up = &serial_txx9_ports[i];
+		if (up->iobase || up->mapbase)
+			uart_remove_one_port(&serial_txx9_reg, up);
+	}
+
+	uart_unregister_driver(&serial_txx9_reg);
+}
+
+module_init(serial_txx9_init);
+module_exit(serial_txx9_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TX39/49 serial driver");
+
+MODULE_ALIAS_CHARDEV_MAJOR(TXX9_TTY_MAJOR);
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
new file mode 100644
index 000000000..a560b729f
--- /dev/null
+++ b/drivers/tty/serial/sh-sci.c
@@ -0,0 +1,3571 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
+ *
+ *  Copyright (C) 2002 - 2011  Paul Mundt
+ *  Copyright (C) 2015 Glider bvba
+ *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
+ *
+ * based off of the old drivers/char/sh-sci.c by:
+ *
+ *   Copyright (C) 1999, 2000  Niibe Yutaka
+ *   Copyright (C) 2000  Sugioka Toshinobu
+ *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
+ *   Modified to support SecureEdge. David McCullough (2002)
+ *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
+ *   Removed SH7300 support (Jul 2007).
+ */
+#undef DEBUG
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/ktime.h>
+#include <linux/major.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/scatterlist.h>
+#include <linux/serial.h>
+#include <linux/serial_sci.h>
+#include <linux/sh_dma.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sysrq.h>
+#include <linux/timer.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#ifdef CONFIG_SUPERH
+#include <asm/sh_bios.h>
+#include <asm/platform_early.h>
+#endif
+
+#include "serial_mctrl_gpio.h"
+#include "sh-sci.h"
+
+/* Offsets into the sci_port->irqs array */
+enum {
+	SCIx_ERI_IRQ,
+	SCIx_RXI_IRQ,
+	SCIx_TXI_IRQ,
+	SCIx_BRI_IRQ,
+	SCIx_DRI_IRQ,
+	SCIx_TEI_IRQ,
+	SCIx_NR_IRQS,
+
+	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
+};
+
+#define SCIx_IRQ_IS_MUXED(port)			\
+	((port)->irqs[SCIx_ERI_IRQ] ==	\
+	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
+	((port)->irqs[SCIx_ERI_IRQ] &&	\
+	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
+
+enum SCI_CLKS {
+	SCI_FCK,		/* Functional Clock */
+	SCI_SCK,		/* Optional External Clock */
+	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
+	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
+	SCI_NUM_CLKS
+};
+
+/* Bit x set means sampling rate x + 1 is supported */
+#define SCI_SR(x)		BIT((x) - 1)
+#define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
+
+#define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
+				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
+				SCI_SR(19) | SCI_SR(27)
+
+#define min_sr(_port)		ffs((_port)->sampling_rate_mask)
+#define max_sr(_port)		fls((_port)->sampling_rate_mask)
+
+/* Iterate over all supported sampling rates, from high to low */
+#define for_each_sr(_sr, _port)						\
+	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
+		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
+
+struct plat_sci_reg {
+	u8 offset, size;
+};
+
+struct sci_port_params {
+	const struct plat_sci_reg regs[SCIx_NR_REGS];
+	unsigned int fifosize;
+	unsigned int overrun_reg;
+	unsigned int overrun_mask;
+	unsigned int sampling_rate_mask;
+	unsigned int error_mask;
+	unsigned int error_clear;
+};
+
+struct sci_port {
+	struct uart_port	port;
+
+	/* Platform configuration */
+	const struct sci_port_params *params;
+	const struct plat_sci_port *cfg;
+	unsigned int		sampling_rate_mask;
+	resource_size_t		reg_size;
+	struct mctrl_gpios	*gpios;
+
+	/* Clocks */
+	struct clk		*clks[SCI_NUM_CLKS];
+	unsigned long		clk_rates[SCI_NUM_CLKS];
+
+	int			irqs[SCIx_NR_IRQS];
+	char			*irqstr[SCIx_NR_IRQS];
+
+	struct dma_chan			*chan_tx;
+	struct dma_chan			*chan_rx;
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	struct dma_chan			*chan_tx_saved;
+	struct dma_chan			*chan_rx_saved;
+	dma_cookie_t			cookie_tx;
+	dma_cookie_t			cookie_rx[2];
+	dma_cookie_t			active_rx;
+	dma_addr_t			tx_dma_addr;
+	unsigned int			tx_dma_len;
+	struct scatterlist		sg_rx[2];
+	void				*rx_buf[2];
+	size_t				buf_len_rx;
+	struct work_struct		work_tx;
+	struct hrtimer			rx_timer;
+	unsigned int			rx_timeout;	/* microseconds */
+#endif
+	unsigned int			rx_frame;
+	int				rx_trigger;
+	struct timer_list		rx_fifo_timer;
+	int				rx_fifo_timeout;
+	u16				hscif_tot;
+
+	bool has_rtscts;
+	bool autorts;
+};
+
+#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
+
+static struct sci_port sci_ports[SCI_NPORTS];
+static unsigned long sci_ports_in_use;
+static struct uart_driver sci_uart_driver;
+
+static inline struct sci_port *
+to_sci_port(struct uart_port *uart)
+{
+	return container_of(uart, struct sci_port, port);
+}
+
+static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
+	/*
+	 * Common SCI definitions, dependent on the port's regshift
+	 * value.
+	 */
+	[SCIx_SCI_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00,  8 },
+			[SCBRR]		= { 0x01,  8 },
+			[SCSCR]		= { 0x02,  8 },
+			[SCxTDR]	= { 0x03,  8 },
+			[SCxSR]		= { 0x04,  8 },
+			[SCxRDR]	= { 0x05,  8 },
+		},
+		.fifosize = 1,
+		.overrun_reg = SCxSR,
+		.overrun_mask = SCI_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
+		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
+	},
+
+	/*
+	 * Common definitions for legacy IrDA ports.
+	 */
+	[SCIx_IRDA_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00,  8 },
+			[SCBRR]		= { 0x02,  8 },
+			[SCSCR]		= { 0x04,  8 },
+			[SCxTDR]	= { 0x06,  8 },
+			[SCxSR]		= { 0x08, 16 },
+			[SCxRDR]	= { 0x0a,  8 },
+			[SCFCR]		= { 0x0c,  8 },
+			[SCFDR]		= { 0x0e, 16 },
+		},
+		.fifosize = 1,
+		.overrun_reg = SCxSR,
+		.overrun_mask = SCI_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
+		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
+	},
+
+	/*
+	 * Common SCIFA definitions.
+	 */
+	[SCIx_SCIFA_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x20,  8 },
+			[SCxSR]		= { 0x14, 16 },
+			[SCxRDR]	= { 0x24,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCPCR]		= { 0x30, 16 },
+			[SCPDR]		= { 0x34, 16 },
+		},
+		.fifosize = 64,
+		.overrun_reg = SCxSR,
+		.overrun_mask = SCIFA_ORER,
+		.sampling_rate_mask = SCI_SR_SCIFAB,
+		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
+		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
+	},
+
+	/*
+	 * Common SCIFB definitions.
+	 */
+	[SCIx_SCIFB_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x40,  8 },
+			[SCxSR]		= { 0x14, 16 },
+			[SCxRDR]	= { 0x60,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCTFDR]	= { 0x38, 16 },
+			[SCRFDR]	= { 0x3c, 16 },
+			[SCPCR]		= { 0x30, 16 },
+			[SCPDR]		= { 0x34, 16 },
+		},
+		.fifosize = 256,
+		.overrun_reg = SCxSR,
+		.overrun_mask = SCIFA_ORER,
+		.sampling_rate_mask = SCI_SR_SCIFAB,
+		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
+		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
+	},
+
+	/*
+	 * Common SH-2(A) SCIF definitions for ports with FIFO data
+	 * count registers.
+	 */
+	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x0c,  8 },
+			[SCxSR]		= { 0x10, 16 },
+			[SCxRDR]	= { 0x14,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCSPTR]	= { 0x20, 16 },
+			[SCLSR]		= { 0x24, 16 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
+	 * It looks like a normal SCIF with FIFO data, but with a
+	 * compressed address space. Also, the break out of interrupts
+	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
+	 */
+	[SCIx_RZ_SCIFA_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x02,  8 },
+			[SCSCR]		= { 0x04, 16 },
+			[SCxTDR]	= { 0x06,  8 },
+			[SCxSR]		= { 0x08, 16 },
+			[SCxRDR]	= { 0x0A,  8 },
+			[SCFCR]		= { 0x0C, 16 },
+			[SCFDR]		= { 0x0E, 16 },
+			[SCSPTR]	= { 0x10, 16 },
+			[SCLSR]		= { 0x12, 16 },
+			[SEMR]		= { 0x14, 8 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * Common SH-3 SCIF definitions.
+	 */
+	[SCIx_SH3_SCIF_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00,  8 },
+			[SCBRR]		= { 0x02,  8 },
+			[SCSCR]		= { 0x04,  8 },
+			[SCxTDR]	= { 0x06,  8 },
+			[SCxSR]		= { 0x08, 16 },
+			[SCxRDR]	= { 0x0a,  8 },
+			[SCFCR]		= { 0x0c,  8 },
+			[SCFDR]		= { 0x0e, 16 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * Common SH-4(A) SCIF(B) definitions.
+	 */
+	[SCIx_SH4_SCIF_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x0c,  8 },
+			[SCxSR]		= { 0x10, 16 },
+			[SCxRDR]	= { 0x14,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCSPTR]	= { 0x20, 16 },
+			[SCLSR]		= { 0x24, 16 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * Common SCIF definitions for ports with a Baud Rate Generator for
+	 * External Clock (BRG).
+	 */
+	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x0c,  8 },
+			[SCxSR]		= { 0x10, 16 },
+			[SCxRDR]	= { 0x14,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCSPTR]	= { 0x20, 16 },
+			[SCLSR]		= { 0x24, 16 },
+			[SCDL]		= { 0x30, 16 },
+			[SCCKS]		= { 0x34, 16 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * Common HSCIF definitions.
+	 */
+	[SCIx_HSCIF_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x0c,  8 },
+			[SCxSR]		= { 0x10, 16 },
+			[SCxRDR]	= { 0x14,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCSPTR]	= { 0x20, 16 },
+			[SCLSR]		= { 0x24, 16 },
+			[HSSRR]		= { 0x40, 16 },
+			[SCDL]		= { 0x30, 16 },
+			[SCCKS]		= { 0x34, 16 },
+			[HSRTRGR]	= { 0x54, 16 },
+			[HSTTRGR]	= { 0x58, 16 },
+		},
+		.fifosize = 128,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
+	 * register.
+	 */
+	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x0c,  8 },
+			[SCxSR]		= { 0x10, 16 },
+			[SCxRDR]	= { 0x14,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCLSR]		= { 0x24, 16 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
+	 * count registers.
+	 */
+	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x0c,  8 },
+			[SCxSR]		= { 0x10, 16 },
+			[SCxRDR]	= { 0x14,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
+			[SCRFDR]	= { 0x20, 16 },
+			[SCSPTR]	= { 0x24, 16 },
+			[SCLSR]		= { 0x28, 16 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
+	/*
+	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
+	 * registers.
+	 */
+	[SCIx_SH7705_SCIF_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x04,  8 },
+			[SCSCR]		= { 0x08, 16 },
+			[SCxTDR]	= { 0x20,  8 },
+			[SCxSR]		= { 0x14, 16 },
+			[SCxRDR]	= { 0x24,  8 },
+			[SCFCR]		= { 0x18, 16 },
+			[SCFDR]		= { 0x1c, 16 },
+		},
+		.fifosize = 64,
+		.overrun_reg = SCxSR,
+		.overrun_mask = SCIFA_ORER,
+		.sampling_rate_mask = SCI_SR(16),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
+		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
+	},
+};
+
+#define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
+
+/*
+ * The "offset" here is rather misleading, in that it refers to an enum
+ * value relative to the port mapping rather than the fixed offset
+ * itself, which needs to be manually retrieved from the platform's
+ * register map for the given port.
+ */
+static unsigned int sci_serial_in(struct uart_port *p, int offset)
+{
+	const struct plat_sci_reg *reg = sci_getreg(p, offset);
+
+	if (reg->size == 8)
+		return ioread8(p->membase + (reg->offset << p->regshift));
+	else if (reg->size == 16)
+		return ioread16(p->membase + (reg->offset << p->regshift));
+	else
+		WARN(1, "Invalid register access\n");
+
+	return 0;
+}
+
+static void sci_serial_out(struct uart_port *p, int offset, int value)
+{
+	const struct plat_sci_reg *reg = sci_getreg(p, offset);
+
+	if (reg->size == 8)
+		iowrite8(value, p->membase + (reg->offset << p->regshift));
+	else if (reg->size == 16)
+		iowrite16(value, p->membase + (reg->offset << p->regshift));
+	else
+		WARN(1, "Invalid register access\n");
+}
+
+static void sci_port_enable(struct sci_port *sci_port)
+{
+	unsigned int i;
+
+	if (!sci_port->port.dev)
+		return;
+
+	pm_runtime_get_sync(sci_port->port.dev);
+
+	for (i = 0; i < SCI_NUM_CLKS; i++) {
+		clk_prepare_enable(sci_port->clks[i]);
+		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
+	}
+	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
+}
+
+static void sci_port_disable(struct sci_port *sci_port)
+{
+	unsigned int i;
+
+	if (!sci_port->port.dev)
+		return;
+
+	for (i = SCI_NUM_CLKS; i-- > 0; )
+		clk_disable_unprepare(sci_port->clks[i]);
+
+	pm_runtime_put_sync(sci_port->port.dev);
+}
+
+static inline unsigned long port_rx_irq_mask(struct uart_port *port)
+{
+	/*
+	 * Not all ports (such as SCIFA) will support REIE. Rather than
+	 * special-casing the port type, we check the port initialization
+	 * IRQ enable mask to see whether the IRQ is desired at all. If
+	 * it's unset, it's logically inferred that there's no point in
+	 * testing for it.
+	 */
+	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
+}
+
+static void sci_start_tx(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	unsigned short ctrl;
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		u16 new, scr = serial_port_in(port, SCSCR);
+		if (s->chan_tx)
+			new = scr | SCSCR_TDRQE;
+		else
+			new = scr & ~SCSCR_TDRQE;
+		if (new != scr)
+			serial_port_out(port, SCSCR, new);
+	}
+
+	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
+	    dma_submit_error(s->cookie_tx)) {
+		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
+			/* Switch irq from SCIF to DMA */
+			disable_irq_nosync(s->irqs[SCIx_TXI_IRQ]);
+
+		s->cookie_tx = 0;
+		schedule_work(&s->work_tx);
+	}
+#endif
+
+	if (!s->chan_tx || s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE ||
+	    port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
+		ctrl = serial_port_in(port, SCSCR);
+
+		/*
+		 * For SCI, TE (transmit enable) must be set after setting TIE
+		 * (transmit interrupt enable) or in the same instruction to start
+		 * the transmit process.
+		 */
+		if (port->type == PORT_SCI)
+			ctrl |= SCSCR_TE;
+
+		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
+	}
+}
+
+static void sci_stop_tx(struct uart_port *port)
+{
+	unsigned short ctrl;
+
+	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
+	ctrl = serial_port_in(port, SCSCR);
+
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		ctrl &= ~SCSCR_TDRQE;
+
+	ctrl &= ~SCSCR_TIE;
+
+	serial_port_out(port, SCSCR, ctrl);
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	if (to_sci_port(port)->chan_tx &&
+	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
+		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
+		to_sci_port(port)->cookie_tx = -EINVAL;
+	}
+#endif
+}
+
+static void sci_start_rx(struct uart_port *port)
+{
+	unsigned short ctrl;
+
+	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
+
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		ctrl &= ~SCSCR_RDRQE;
+
+	serial_port_out(port, SCSCR, ctrl);
+}
+
+static void sci_stop_rx(struct uart_port *port)
+{
+	unsigned short ctrl;
+
+	ctrl = serial_port_in(port, SCSCR);
+
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		ctrl &= ~SCSCR_RDRQE;
+
+	ctrl &= ~port_rx_irq_mask(port);
+
+	serial_port_out(port, SCSCR, ctrl);
+}
+
+static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
+{
+	if (port->type == PORT_SCI) {
+		/* Just store the mask */
+		serial_port_out(port, SCxSR, mask);
+	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
+		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
+		/* Only clear the status bits we want to clear */
+		serial_port_out(port, SCxSR,
+				serial_port_in(port, SCxSR) & mask);
+	} else {
+		/* Store the mask, clear parity/framing errors */
+		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
+	}
+}
+
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
+    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
+
+#ifdef CONFIG_CONSOLE_POLL
+static int sci_poll_get_char(struct uart_port *port)
+{
+	unsigned short status;
+	int c;
+
+	do {
+		status = serial_port_in(port, SCxSR);
+		if (status & SCxSR_ERRORS(port)) {
+			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
+			continue;
+		}
+		break;
+	} while (1);
+
+	if (!(status & SCxSR_RDxF(port)))
+		return NO_POLL_CHAR;
+
+	c = serial_port_in(port, SCxRDR);
+
+	/* Dummy read */
+	serial_port_in(port, SCxSR);
+	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
+
+	return c;
+}
+#endif
+
+static void sci_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned short status;
+
+	do {
+		status = serial_port_in(port, SCxSR);
+	} while (!(status & SCxSR_TDxE(port)));
+
+	serial_port_out(port, SCxTDR, c);
+	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
+}
+#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
+	  CONFIG_SERIAL_SH_SCI_EARLYCON */
+
+static void sci_init_pins(struct uart_port *port, unsigned int cflag)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	/*
+	 * Use port-specific handler if provided.
+	 */
+	if (s->cfg->ops && s->cfg->ops->init_pins) {
+		s->cfg->ops->init_pins(port, cflag);
+		return;
+	}
+
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		u16 data = serial_port_in(port, SCPDR);
+		u16 ctrl = serial_port_in(port, SCPCR);
+
+		/* Enable RXD and TXD pin functions */
+		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
+		if (to_sci_port(port)->has_rtscts) {
+			/* RTS# is output, active low, unless autorts */
+			if (!(port->mctrl & TIOCM_RTS)) {
+				ctrl |= SCPCR_RTSC;
+				data |= SCPDR_RTSD;
+			} else if (!s->autorts) {
+				ctrl |= SCPCR_RTSC;
+				data &= ~SCPDR_RTSD;
+			} else {
+				/* Enable RTS# pin function */
+				ctrl &= ~SCPCR_RTSC;
+			}
+			/* Enable CTS# pin function */
+			ctrl &= ~SCPCR_CTSC;
+		}
+		serial_port_out(port, SCPDR, data);
+		serial_port_out(port, SCPCR, ctrl);
+	} else if (sci_getreg(port, SCSPTR)->size) {
+		u16 status = serial_port_in(port, SCSPTR);
+
+		/* RTS# is always output; and active low, unless autorts */
+		status |= SCSPTR_RTSIO;
+		if (!(port->mctrl & TIOCM_RTS))
+			status |= SCSPTR_RTSDT;
+		else if (!s->autorts)
+			status &= ~SCSPTR_RTSDT;
+		/* CTS# and SCK are inputs */
+		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
+		serial_port_out(port, SCSPTR, status);
+	}
+}
+
+static int sci_txfill(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
+	const struct plat_sci_reg *reg;
+
+	reg = sci_getreg(port, SCTFDR);
+	if (reg->size)
+		return serial_port_in(port, SCTFDR) & fifo_mask;
+
+	reg = sci_getreg(port, SCFDR);
+	if (reg->size)
+		return serial_port_in(port, SCFDR) >> 8;
+
+	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
+}
+
+static int sci_txroom(struct uart_port *port)
+{
+	return port->fifosize - sci_txfill(port);
+}
+
+static int sci_rxfill(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
+	const struct plat_sci_reg *reg;
+
+	reg = sci_getreg(port, SCRFDR);
+	if (reg->size)
+		return serial_port_in(port, SCRFDR) & fifo_mask;
+
+	reg = sci_getreg(port, SCFDR);
+	if (reg->size)
+		return serial_port_in(port, SCFDR) & fifo_mask;
+
+	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
+}
+
+/* ********************************************************************** *
+ *                   the interrupt related routines                       *
+ * ********************************************************************** */
+
+static void sci_transmit_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int stopped = uart_tx_stopped(port);
+	unsigned short status;
+	unsigned short ctrl;
+	int count;
+
+	status = serial_port_in(port, SCxSR);
+	if (!(status & SCxSR_TDxE(port))) {
+		ctrl = serial_port_in(port, SCSCR);
+		if (uart_circ_empty(xmit))
+			ctrl &= ~SCSCR_TIE;
+		else
+			ctrl |= SCSCR_TIE;
+		serial_port_out(port, SCSCR, ctrl);
+		return;
+	}
+
+	count = sci_txroom(port);
+
+	do {
+		unsigned char c;
+
+		if (port->x_char) {
+			c = port->x_char;
+			port->x_char = 0;
+		} else if (!uart_circ_empty(xmit) && !stopped) {
+			c = xmit->buf[xmit->tail];
+			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		} else if (port->type == PORT_SCI && uart_circ_empty(xmit)) {
+			ctrl = serial_port_in(port, SCSCR);
+			ctrl &= ~SCSCR_TE;
+			serial_port_out(port, SCSCR, ctrl);
+			return;
+		} else {
+			break;
+		}
+
+		serial_port_out(port, SCxTDR, c);
+
+		port->icount.tx++;
+	} while (--count > 0);
+
+	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+	if (uart_circ_empty(xmit)) {
+		if (port->type == PORT_SCI) {
+			ctrl = serial_port_in(port, SCSCR);
+			ctrl &= ~SCSCR_TIE;
+			ctrl |= SCSCR_TEIE;
+			serial_port_out(port, SCSCR, ctrl);
+		}
+
+		sci_stop_tx(port);
+	}
+}
+
+static void sci_receive_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	int i, count, copied = 0;
+	unsigned short status;
+	unsigned char flag;
+
+	status = serial_port_in(port, SCxSR);
+	if (!(status & SCxSR_RDxF(port)))
+		return;
+
+	while (1) {
+		/* Don't copy more bytes than there is room for in the buffer */
+		count = tty_buffer_request_room(tport, sci_rxfill(port));
+
+		/* If for any reason we can't copy more data, we're done! */
+		if (count == 0)
+			break;
+
+		if (port->type == PORT_SCI) {
+			char c = serial_port_in(port, SCxRDR);
+			if (uart_handle_sysrq_char(port, c))
+				count = 0;
+			else
+				tty_insert_flip_char(tport, c, TTY_NORMAL);
+		} else {
+			for (i = 0; i < count; i++) {
+				char c;
+
+				if (port->type == PORT_SCIF ||
+				    port->type == PORT_HSCIF) {
+					status = serial_port_in(port, SCxSR);
+					c = serial_port_in(port, SCxRDR);
+				} else {
+					c = serial_port_in(port, SCxRDR);
+					status = serial_port_in(port, SCxSR);
+				}
+				if (uart_handle_sysrq_char(port, c)) {
+					count--; i--;
+					continue;
+				}
+
+				/* Store data and status */
+				if (status & SCxSR_FER(port)) {
+					flag = TTY_FRAME;
+					port->icount.frame++;
+				} else if (status & SCxSR_PER(port)) {
+					flag = TTY_PARITY;
+					port->icount.parity++;
+				} else
+					flag = TTY_NORMAL;
+
+				tty_insert_flip_char(tport, c, flag);
+			}
+		}
+
+		serial_port_in(port, SCxSR); /* dummy read */
+		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
+
+		copied += count;
+		port->icount.rx += count;
+	}
+
+	if (copied) {
+		/* Tell the rest of the system the news. New characters! */
+		tty_flip_buffer_push(tport);
+	} else {
+		/* TTY buffers full; read from RX reg to prevent lockup */
+		serial_port_in(port, SCxRDR);
+		serial_port_in(port, SCxSR); /* dummy read */
+		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
+	}
+}
+
+static int sci_handle_errors(struct uart_port *port)
+{
+	int copied = 0;
+	unsigned short status = serial_port_in(port, SCxSR);
+	struct tty_port *tport = &port->state->port;
+	struct sci_port *s = to_sci_port(port);
+
+	/* Handle overruns */
+	if (status & s->params->overrun_mask) {
+		port->icount.overrun++;
+
+		/* overrun error */
+		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
+			copied++;
+	}
+
+	if (status & SCxSR_FER(port)) {
+		/* frame error */
+		port->icount.frame++;
+
+		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
+			copied++;
+	}
+
+	if (status & SCxSR_PER(port)) {
+		/* parity error */
+		port->icount.parity++;
+
+		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
+			copied++;
+	}
+
+	if (copied)
+		tty_flip_buffer_push(tport);
+
+	return copied;
+}
+
+static int sci_handle_fifo_overrun(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	struct sci_port *s = to_sci_port(port);
+	const struct plat_sci_reg *reg;
+	int copied = 0;
+	u16 status;
+
+	reg = sci_getreg(port, s->params->overrun_reg);
+	if (!reg->size)
+		return 0;
+
+	status = serial_port_in(port, s->params->overrun_reg);
+	if (status & s->params->overrun_mask) {
+		status &= ~s->params->overrun_mask;
+		serial_port_out(port, s->params->overrun_reg, status);
+
+		port->icount.overrun++;
+
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+		tty_flip_buffer_push(tport);
+		copied++;
+	}
+
+	return copied;
+}
+
+static int sci_handle_breaks(struct uart_port *port)
+{
+	int copied = 0;
+	unsigned short status = serial_port_in(port, SCxSR);
+	struct tty_port *tport = &port->state->port;
+
+	if (uart_handle_break(port))
+		return 0;
+
+	if (status & SCxSR_BRK(port)) {
+		port->icount.brk++;
+
+		/* Notify of BREAK */
+		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
+			copied++;
+	}
+
+	if (copied)
+		tty_flip_buffer_push(tport);
+
+	copied += sci_handle_fifo_overrun(port);
+
+	return copied;
+}
+
+static int scif_set_rtrg(struct uart_port *port, int rx_trig)
+{
+	unsigned int bits;
+
+	if (rx_trig >= port->fifosize)
+		rx_trig = port->fifosize - 1;
+	if (rx_trig < 1)
+		rx_trig = 1;
+
+	/* HSCIF can be set to an arbitrary level. */
+	if (sci_getreg(port, HSRTRGR)->size) {
+		serial_port_out(port, HSRTRGR, rx_trig);
+		return rx_trig;
+	}
+
+	switch (port->type) {
+	case PORT_SCIF:
+		if (rx_trig < 4) {
+			bits = 0;
+			rx_trig = 1;
+		} else if (rx_trig < 8) {
+			bits = SCFCR_RTRG0;
+			rx_trig = 4;
+		} else if (rx_trig < 14) {
+			bits = SCFCR_RTRG1;
+			rx_trig = 8;
+		} else {
+			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
+			rx_trig = 14;
+		}
+		break;
+	case PORT_SCIFA:
+	case PORT_SCIFB:
+		if (rx_trig < 16) {
+			bits = 0;
+			rx_trig = 1;
+		} else if (rx_trig < 32) {
+			bits = SCFCR_RTRG0;
+			rx_trig = 16;
+		} else if (rx_trig < 48) {
+			bits = SCFCR_RTRG1;
+			rx_trig = 32;
+		} else {
+			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
+			rx_trig = 48;
+		}
+		break;
+	default:
+		WARN(1, "unknown FIFO configuration");
+		return 1;
+	}
+
+	serial_port_out(port, SCFCR,
+		(serial_port_in(port, SCFCR) &
+		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
+
+	return rx_trig;
+}
+
+static int scif_rtrg_enabled(struct uart_port *port)
+{
+	if (sci_getreg(port, HSRTRGR)->size)
+		return serial_port_in(port, HSRTRGR) != 0;
+	else
+		return (serial_port_in(port, SCFCR) &
+			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
+}
+
+static void rx_fifo_timer_fn(struct timer_list *t)
+{
+	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
+	struct uart_port *port = &s->port;
+
+	dev_dbg(port->dev, "Rx timed out\n");
+	scif_set_rtrg(port, 1);
+}
+
+static ssize_t rx_fifo_trigger_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct sci_port *sci = to_sci_port(port);
+
+	return sprintf(buf, "%d\n", sci->rx_trigger);
+}
+
+static ssize_t rx_fifo_trigger_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct sci_port *sci = to_sci_port(port);
+	int ret;
+	long r;
+
+	ret = kstrtol(buf, 0, &r);
+	if (ret)
+		return ret;
+
+	sci->rx_trigger = scif_set_rtrg(port, r);
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+		scif_set_rtrg(port, 1);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(rx_fifo_trigger);
+
+static ssize_t rx_fifo_timeout_show(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct sci_port *sci = to_sci_port(port);
+	int v;
+
+	if (port->type == PORT_HSCIF)
+		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
+	else
+		v = sci->rx_fifo_timeout;
+
+	return sprintf(buf, "%d\n", v);
+}
+
+static ssize_t rx_fifo_timeout_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf,
+				size_t count)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct sci_port *sci = to_sci_port(port);
+	int ret;
+	long r;
+
+	ret = kstrtol(buf, 0, &r);
+	if (ret)
+		return ret;
+
+	if (port->type == PORT_HSCIF) {
+		if (r < 0 || r > 3)
+			return -EINVAL;
+		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
+	} else {
+		sci->rx_fifo_timeout = r;
+		scif_set_rtrg(port, 1);
+		if (r > 0)
+			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(rx_fifo_timeout);
+
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+static void sci_dma_tx_complete(void *arg)
+{
+	struct sci_port *s = arg;
+	struct uart_port *port = &s->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
+
+	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_xmit_advance(port, s->tx_dma_len);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (!uart_circ_empty(xmit)) {
+		s->cookie_tx = 0;
+		schedule_work(&s->work_tx);
+	} else {
+		s->cookie_tx = -EINVAL;
+		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
+		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
+			u16 ctrl = serial_port_in(port, SCSCR);
+			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
+			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
+				/* Switch irq from DMA to SCIF */
+				dmaengine_pause(s->chan_tx_saved);
+				enable_irq(s->irqs[SCIx_TXI_IRQ]);
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Locking: called with port lock held */
+static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
+{
+	struct uart_port *port = &s->port;
+	struct tty_port *tport = &port->state->port;
+	int copied;
+
+	copied = tty_insert_flip_string(tport, buf, count);
+	if (copied < count)
+		port->icount.buf_overrun++;
+
+	port->icount.rx += copied;
+
+	return copied;
+}
+
+static int sci_dma_rx_find_active(struct sci_port *s)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
+		if (s->active_rx == s->cookie_rx[i])
+			return i;
+
+	return -1;
+}
+
+static void sci_dma_rx_chan_invalidate(struct sci_port *s)
+{
+	unsigned int i;
+
+	s->chan_rx = NULL;
+	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
+		s->cookie_rx[i] = -EINVAL;
+	s->active_rx = 0;
+}
+
+static void sci_dma_rx_release(struct sci_port *s)
+{
+	struct dma_chan *chan = s->chan_rx_saved;
+
+	s->chan_rx_saved = NULL;
+	sci_dma_rx_chan_invalidate(s);
+	dmaengine_terminate_sync(chan);
+	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
+			  sg_dma_address(&s->sg_rx[0]));
+	dma_release_channel(chan);
+}
+
+static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
+{
+	long sec = usec / 1000000;
+	long nsec = (usec % 1000000) * 1000;
+	ktime_t t = ktime_set(sec, nsec);
+
+	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
+}
+
+static void sci_dma_rx_reenable_irq(struct sci_port *s)
+{
+	struct uart_port *port = &s->port;
+	u16 scr;
+
+	/* Direct new serial port interrupts back to CPU */
+	scr = serial_port_in(port, SCSCR);
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
+	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
+		enable_irq(s->irqs[SCIx_RXI_IRQ]);
+		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
+			scif_set_rtrg(port, s->rx_trigger);
+		else
+			scr &= ~SCSCR_RDRQE;
+	}
+	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
+}
+
+static void sci_dma_rx_complete(void *arg)
+{
+	struct sci_port *s = arg;
+	struct dma_chan *chan = s->chan_rx;
+	struct uart_port *port = &s->port;
+	struct dma_async_tx_descriptor *desc;
+	unsigned long flags;
+	int active, count = 0;
+
+	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
+		s->active_rx);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	active = sci_dma_rx_find_active(s);
+	if (active >= 0)
+		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
+
+	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
+
+	if (count)
+		tty_flip_buffer_push(&port->state->port);
+
+	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
+				       DMA_DEV_TO_MEM,
+				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		goto fail;
+
+	desc->callback = sci_dma_rx_complete;
+	desc->callback_param = s;
+	s->cookie_rx[active] = dmaengine_submit(desc);
+	if (dma_submit_error(s->cookie_rx[active]))
+		goto fail;
+
+	s->active_rx = s->cookie_rx[!active];
+
+	dma_async_issue_pending(chan);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
+		__func__, s->cookie_rx[active], active, s->active_rx);
+	return;
+
+fail:
+	spin_unlock_irqrestore(&port->lock, flags);
+	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
+	/* Switch to PIO */
+	spin_lock_irqsave(&port->lock, flags);
+	dmaengine_terminate_async(chan);
+	sci_dma_rx_chan_invalidate(s);
+	sci_dma_rx_reenable_irq(s);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void sci_dma_tx_release(struct sci_port *s)
+{
+	struct dma_chan *chan = s->chan_tx_saved;
+
+	cancel_work_sync(&s->work_tx);
+	s->chan_tx_saved = s->chan_tx = NULL;
+	s->cookie_tx = -EINVAL;
+	dmaengine_terminate_sync(chan);
+	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
+			 DMA_TO_DEVICE);
+	dma_release_channel(chan);
+}
+
+static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
+{
+	struct dma_chan *chan = s->chan_rx;
+	struct uart_port *port = &s->port;
+	unsigned long flags;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct scatterlist *sg = &s->sg_rx[i];
+		struct dma_async_tx_descriptor *desc;
+
+		desc = dmaengine_prep_slave_sg(chan,
+			sg, 1, DMA_DEV_TO_MEM,
+			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+		if (!desc)
+			goto fail;
+
+		desc->callback = sci_dma_rx_complete;
+		desc->callback_param = s;
+		s->cookie_rx[i] = dmaengine_submit(desc);
+		if (dma_submit_error(s->cookie_rx[i]))
+			goto fail;
+
+	}
+
+	s->active_rx = s->cookie_rx[0];
+
+	dma_async_issue_pending(chan);
+	return 0;
+
+fail:
+	/* Switch to PIO */
+	if (!port_lock_held)
+		spin_lock_irqsave(&port->lock, flags);
+	if (i)
+		dmaengine_terminate_async(chan);
+	sci_dma_rx_chan_invalidate(s);
+	sci_start_rx(port);
+	if (!port_lock_held)
+		spin_unlock_irqrestore(&port->lock, flags);
+	return -EAGAIN;
+}
+
+static void sci_dma_tx_work_fn(struct work_struct *work)
+{
+	struct sci_port *s = container_of(work, struct sci_port, work_tx);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *chan = s->chan_tx;
+	struct uart_port *port = &s->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
+	dma_addr_t buf;
+	int head, tail;
+
+	/*
+	 * DMA is idle now.
+	 * Port xmit buffer is already mapped, and it is one page... Just adjust
+	 * offsets and lengths. Since it is a circular buffer, we have to
+	 * transmit till the end, and then the rest. Take the port lock to get a
+	 * consistent xmit buffer state.
+	 */
+	spin_lock_irq(&port->lock);
+	head = xmit->head;
+	tail = xmit->tail;
+	buf = s->tx_dma_addr + tail;
+	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
+	if (!s->tx_dma_len) {
+		/* Transmit buffer has been flushed */
+		spin_unlock_irq(&port->lock);
+		return;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
+					   DMA_MEM_TO_DEV,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		spin_unlock_irq(&port->lock);
+		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
+		goto switch_to_pio;
+	}
+
+	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
+				   DMA_TO_DEVICE);
+
+	desc->callback = sci_dma_tx_complete;
+	desc->callback_param = s;
+	s->cookie_tx = dmaengine_submit(desc);
+	if (dma_submit_error(s->cookie_tx)) {
+		spin_unlock_irq(&port->lock);
+		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
+		goto switch_to_pio;
+	}
+
+	spin_unlock_irq(&port->lock);
+	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
+		__func__, xmit->buf, tail, head, s->cookie_tx);
+
+	dma_async_issue_pending(chan);
+	return;
+
+switch_to_pio:
+	spin_lock_irqsave(&port->lock, flags);
+	s->chan_tx = NULL;
+	sci_start_tx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+	return;
+}
+
+static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
+{
+	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
+	struct dma_chan *chan = s->chan_rx;
+	struct uart_port *port = &s->port;
+	struct dma_tx_state state;
+	enum dma_status status;
+	unsigned long flags;
+	unsigned int read;
+	int active, count;
+
+	dev_dbg(port->dev, "DMA Rx timed out\n");
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	active = sci_dma_rx_find_active(s);
+	if (active < 0) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		return HRTIMER_NORESTART;
+	}
+
+	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
+	if (status == DMA_COMPLETE) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
+			s->active_rx, active);
+
+		/* Let packet complete handler take care of the packet */
+		return HRTIMER_NORESTART;
+	}
+
+	dmaengine_pause(chan);
+
+	/*
+	 * sometimes DMA transfer doesn't stop even if it is stopped and
+	 * data keeps on coming until transaction is complete so check
+	 * for DMA_COMPLETE again
+	 * Let packet complete handler take care of the packet
+	 */
+	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
+	if (status == DMA_COMPLETE) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
+		return HRTIMER_NORESTART;
+	}
+
+	/* Handle incomplete DMA receive */
+	dmaengine_terminate_async(s->chan_rx);
+	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
+
+	if (read) {
+		count = sci_dma_rx_push(s, s->rx_buf[active], read);
+		if (count)
+			tty_flip_buffer_push(&port->state->port);
+	}
+
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
+	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
+		sci_dma_rx_submit(s, true);
+
+	sci_dma_rx_reenable_irq(s);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return HRTIMER_NORESTART;
+}
+
+static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
+					     enum dma_transfer_direction dir)
+{
+	struct dma_chan *chan;
+	struct dma_slave_config cfg;
+	int ret;
+
+	chan = dma_request_slave_channel(port->dev,
+					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
+	if (!chan) {
+		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
+		return NULL;
+	}
+
+	memset(&cfg, 0, sizeof(cfg));
+	cfg.direction = dir;
+	cfg.dst_addr = port->mapbase +
+		(sci_getreg(port, SCxTDR)->offset << port->regshift);
+	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	cfg.src_addr = port->mapbase +
+		(sci_getreg(port, SCxRDR)->offset << port->regshift);
+	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+
+	ret = dmaengine_slave_config(chan, &cfg);
+	if (ret) {
+		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
+		dma_release_channel(chan);
+		return NULL;
+	}
+
+	return chan;
+}
+
+static void sci_request_dma(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	struct dma_chan *chan;
+
+	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
+
+	/*
+	 * DMA on console may interfere with Kernel log messages which use
+	 * plain putchar(). So, simply don't use it with a console.
+	 */
+	if (uart_console(port))
+		return;
+
+	if (!port->dev->of_node)
+		return;
+
+	s->cookie_tx = -EINVAL;
+
+	/*
+	 * Don't request a dma channel if no channel was specified
+	 * in the device tree.
+	 */
+	if (!of_property_present(port->dev->of_node, "dmas"))
+		return;
+
+	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
+	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
+	if (chan) {
+		/* UART circular tx buffer is an aligned page. */
+		s->tx_dma_addr = dma_map_single(chan->device->dev,
+						port->state->xmit.buf,
+						UART_XMIT_SIZE,
+						DMA_TO_DEVICE);
+		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
+			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
+			dma_release_channel(chan);
+		} else {
+			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
+				__func__, UART_XMIT_SIZE,
+				port->state->xmit.buf, &s->tx_dma_addr);
+
+			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
+			s->chan_tx_saved = s->chan_tx = chan;
+		}
+	}
+
+	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
+	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
+	if (chan) {
+		unsigned int i;
+		dma_addr_t dma;
+		void *buf;
+
+		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
+		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
+					 &dma, GFP_KERNEL);
+		if (!buf) {
+			dev_warn(port->dev,
+				 "Failed to allocate Rx dma buffer, using PIO\n");
+			dma_release_channel(chan);
+			return;
+		}
+
+		for (i = 0; i < 2; i++) {
+			struct scatterlist *sg = &s->sg_rx[i];
+
+			sg_init_table(sg, 1);
+			s->rx_buf[i] = buf;
+			sg_dma_address(sg) = dma;
+			sg_dma_len(sg) = s->buf_len_rx;
+
+			buf += s->buf_len_rx;
+			dma += s->buf_len_rx;
+		}
+
+		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+		s->rx_timer.function = sci_dma_rx_timer_fn;
+
+		s->chan_rx_saved = s->chan_rx = chan;
+
+		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
+		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
+			sci_dma_rx_submit(s, false);
+	}
+}
+
+static void sci_free_dma(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	if (s->chan_tx_saved)
+		sci_dma_tx_release(s);
+	if (s->chan_rx_saved)
+		sci_dma_rx_release(s);
+}
+
+static void sci_flush_buffer(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	/*
+	 * In uart_flush_buffer(), the xmit circular buffer has just been
+	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
+	 * pending transfers
+	 */
+	s->tx_dma_len = 0;
+	if (s->chan_tx) {
+		dmaengine_terminate_async(s->chan_tx);
+		s->cookie_tx = -EINVAL;
+	}
+}
+#else /* !CONFIG_SERIAL_SH_SCI_DMA */
+static inline void sci_request_dma(struct uart_port *port)
+{
+}
+
+static inline void sci_free_dma(struct uart_port *port)
+{
+}
+
+#define sci_flush_buffer	NULL
+#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
+
+static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	struct sci_port *s = to_sci_port(port);
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	if (s->chan_rx) {
+		u16 scr = serial_port_in(port, SCSCR);
+		u16 ssr = serial_port_in(port, SCxSR);
+
+		/* Disable future Rx interrupts */
+		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
+		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
+			disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
+			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
+				scif_set_rtrg(port, 1);
+				scr |= SCSCR_RIE;
+			} else {
+				scr |= SCSCR_RDRQE;
+			}
+		} else {
+			if (sci_dma_rx_submit(s, false) < 0)
+				goto handle_pio;
+
+			scr &= ~SCSCR_RIE;
+		}
+		serial_port_out(port, SCSCR, scr);
+		/* Clear current interrupt */
+		serial_port_out(port, SCxSR,
+				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
+		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
+			jiffies, s->rx_timeout);
+		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
+
+		return IRQ_HANDLED;
+	}
+
+handle_pio:
+#endif
+
+	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
+		if (!scif_rtrg_enabled(port))
+			scif_set_rtrg(port, s->rx_trigger);
+
+		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
+			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
+	}
+
+	/* I think sci_receive_chars has to be called irrespective
+	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
+	 * to be disabled?
+	 */
+	sci_receive_chars(port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	sci_transmit_chars(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	unsigned long flags;
+	unsigned short ctrl;
+
+	if (port->type != PORT_SCI)
+		return sci_tx_interrupt(irq, ptr);
+
+	spin_lock_irqsave(&port->lock, flags);
+	ctrl = serial_port_in(port, SCSCR);
+	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
+	serial_port_out(port, SCSCR, ctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_br_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+
+	/* Handle BREAKs */
+	sci_handle_breaks(port);
+
+	/* drop invalid character received before break was detected */
+	serial_port_in(port, SCxRDR);
+
+	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_er_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	struct sci_port *s = to_sci_port(port);
+
+	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
+		/* Break and Error interrupts are muxed */
+		unsigned short ssr_status = serial_port_in(port, SCxSR);
+
+		/* Break Interrupt */
+		if (ssr_status & SCxSR_BRK(port))
+			sci_br_interrupt(irq, ptr);
+
+		/* Break only? */
+		if (!(ssr_status & SCxSR_ERRORS(port)))
+			return IRQ_HANDLED;
+	}
+
+	/* Handle errors */
+	if (port->type == PORT_SCI) {
+		if (sci_handle_errors(port)) {
+			/* discard character in rx buffer */
+			serial_port_in(port, SCxSR);
+			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
+		}
+	} else {
+		sci_handle_fifo_overrun(port);
+		if (!s->chan_rx)
+			sci_receive_chars(port);
+	}
+
+	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
+
+	/* Kick the transmission */
+	if (!s->chan_tx)
+		sci_tx_interrupt(irq, ptr);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
+{
+	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
+	struct uart_port *port = ptr;
+	struct sci_port *s = to_sci_port(port);
+	irqreturn_t ret = IRQ_NONE;
+
+	ssr_status = serial_port_in(port, SCxSR);
+	scr_status = serial_port_in(port, SCSCR);
+	if (s->params->overrun_reg == SCxSR)
+		orer_status = ssr_status;
+	else if (sci_getreg(port, s->params->overrun_reg)->size)
+		orer_status = serial_port_in(port, s->params->overrun_reg);
+
+	err_enabled = scr_status & port_rx_irq_mask(port);
+
+	/* Tx Interrupt */
+	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
+	    !s->chan_tx)
+		ret = sci_tx_interrupt(irq, ptr);
+
+	/*
+	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
+	 * DR flags
+	 */
+	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
+	    (scr_status & SCSCR_RIE))
+		ret = sci_rx_interrupt(irq, ptr);
+
+	/* Error Interrupt */
+	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
+		ret = sci_er_interrupt(irq, ptr);
+
+	/* Break Interrupt */
+	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
+	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
+		ret = sci_br_interrupt(irq, ptr);
+
+	/* Overrun Interrupt */
+	if (orer_status & s->params->overrun_mask) {
+		sci_handle_fifo_overrun(port);
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+static const struct sci_irq_desc {
+	const char	*desc;
+	irq_handler_t	handler;
+} sci_irq_desc[] = {
+	/*
+	 * Split out handlers, the default case.
+	 */
+	[SCIx_ERI_IRQ] = {
+		.desc = "rx err",
+		.handler = sci_er_interrupt,
+	},
+
+	[SCIx_RXI_IRQ] = {
+		.desc = "rx full",
+		.handler = sci_rx_interrupt,
+	},
+
+	[SCIx_TXI_IRQ] = {
+		.desc = "tx empty",
+		.handler = sci_tx_interrupt,
+	},
+
+	[SCIx_BRI_IRQ] = {
+		.desc = "break",
+		.handler = sci_br_interrupt,
+	},
+
+	[SCIx_DRI_IRQ] = {
+		.desc = "rx ready",
+		.handler = sci_rx_interrupt,
+	},
+
+	[SCIx_TEI_IRQ] = {
+		.desc = "tx end",
+		.handler = sci_tx_end_interrupt,
+	},
+
+	/*
+	 * Special muxed handler.
+	 */
+	[SCIx_MUX_IRQ] = {
+		.desc = "mux",
+		.handler = sci_mpxed_interrupt,
+	},
+};
+
+static int sci_request_irq(struct sci_port *port)
+{
+	struct uart_port *up = &port->port;
+	int i, j, w, ret = 0;
+
+	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
+		const struct sci_irq_desc *desc;
+		int irq;
+
+		/* Check if already registered (muxed) */
+		for (w = 0; w < i; w++)
+			if (port->irqs[w] == port->irqs[i])
+				w = i + 1;
+		if (w > i)
+			continue;
+
+		if (SCIx_IRQ_IS_MUXED(port)) {
+			i = SCIx_MUX_IRQ;
+			irq = up->irq;
+		} else {
+			irq = port->irqs[i];
+
+			/*
+			 * Certain port types won't support all of the
+			 * available interrupt sources.
+			 */
+			if (unlikely(irq < 0))
+				continue;
+		}
+
+		desc = sci_irq_desc + i;
+		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
+					    dev_name(up->dev), desc->desc);
+		if (!port->irqstr[j]) {
+			ret = -ENOMEM;
+			goto out_nomem;
+		}
+
+		ret = request_irq(irq, desc->handler, up->irqflags,
+				  port->irqstr[j], port);
+		if (unlikely(ret)) {
+			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
+			goto out_noirq;
+		}
+	}
+
+	return 0;
+
+out_noirq:
+	while (--i >= 0)
+		free_irq(port->irqs[i], port);
+
+out_nomem:
+	while (--j >= 0)
+		kfree(port->irqstr[j]);
+
+	return ret;
+}
+
+static void sci_free_irq(struct sci_port *port)
+{
+	int i, j;
+
+	/*
+	 * Intentionally in reverse order so we iterate over the muxed
+	 * IRQ first.
+	 */
+	for (i = 0; i < SCIx_NR_IRQS; i++) {
+		int irq = port->irqs[i];
+
+		/*
+		 * Certain port types won't support all of the available
+		 * interrupt sources.
+		 */
+		if (unlikely(irq < 0))
+			continue;
+
+		/* Check if already freed (irq was muxed) */
+		for (j = 0; j < i; j++)
+			if (port->irqs[j] == irq)
+				j = i + 1;
+		if (j > i)
+			continue;
+
+		free_irq(port->irqs[i], port);
+		kfree(port->irqstr[i]);
+
+		if (SCIx_IRQ_IS_MUXED(port)) {
+			/* If there's only one IRQ, we're done. */
+			return;
+		}
+	}
+}
+
+static unsigned int sci_tx_empty(struct uart_port *port)
+{
+	unsigned short status = serial_port_in(port, SCxSR);
+	unsigned short in_tx_fifo = sci_txfill(port);
+
+	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
+}
+
+static void sci_set_rts(struct uart_port *port, bool state)
+{
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		u16 data = serial_port_in(port, SCPDR);
+
+		/* Active low */
+		if (state)
+			data &= ~SCPDR_RTSD;
+		else
+			data |= SCPDR_RTSD;
+		serial_port_out(port, SCPDR, data);
+
+		/* RTS# is output */
+		serial_port_out(port, SCPCR,
+				serial_port_in(port, SCPCR) | SCPCR_RTSC);
+	} else if (sci_getreg(port, SCSPTR)->size) {
+		u16 ctrl = serial_port_in(port, SCSPTR);
+
+		/* Active low */
+		if (state)
+			ctrl &= ~SCSPTR_RTSDT;
+		else
+			ctrl |= SCSPTR_RTSDT;
+		serial_port_out(port, SCSPTR, ctrl);
+	}
+}
+
+static bool sci_get_cts(struct uart_port *port)
+{
+	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+		/* Active low */
+		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
+	} else if (sci_getreg(port, SCSPTR)->size) {
+		/* Active low */
+		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
+	}
+
+	return true;
+}
+
+/*
+ * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
+ * CTS/RTS is supported in hardware by at least one port and controlled
+ * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
+ * handled via the ->init_pins() op, which is a bit of a one-way street,
+ * lacking any ability to defer pin control -- this will later be
+ * converted over to the GPIO framework).
+ *
+ * Other modes (such as loopback) are supported generically on certain
+ * port types, but not others. For these it's sufficient to test for the
+ * existence of the support register and simply ignore the port type.
+ */
+static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct sci_port *s = to_sci_port(port);
+
+	if (mctrl & TIOCM_LOOP) {
+		const struct plat_sci_reg *reg;
+
+		/*
+		 * Standard loopback mode for SCFCR ports.
+		 */
+		reg = sci_getreg(port, SCFCR);
+		if (reg->size)
+			serial_port_out(port, SCFCR,
+					serial_port_in(port, SCFCR) |
+					SCFCR_LOOP);
+	}
+
+	mctrl_gpio_set(s->gpios, mctrl);
+
+	if (!s->has_rtscts)
+		return;
+
+	if (!(mctrl & TIOCM_RTS)) {
+		/* Disable Auto RTS */
+		serial_port_out(port, SCFCR,
+				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
+
+		/* Clear RTS */
+		sci_set_rts(port, 0);
+	} else if (s->autorts) {
+		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
+			/* Enable RTS# pin function */
+			serial_port_out(port, SCPCR,
+				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
+		}
+
+		/* Enable Auto RTS */
+		serial_port_out(port, SCFCR,
+				serial_port_in(port, SCFCR) | SCFCR_MCE);
+	} else {
+		/* Set RTS */
+		sci_set_rts(port, 1);
+	}
+}
+
+static unsigned int sci_get_mctrl(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	struct mctrl_gpios *gpios = s->gpios;
+	unsigned int mctrl = 0;
+
+	mctrl_gpio_get(gpios, &mctrl);
+
+	/*
+	 * CTS/RTS is handled in hardware when supported, while nothing
+	 * else is wired up.
+	 */
+	if (s->autorts) {
+		if (sci_get_cts(port))
+			mctrl |= TIOCM_CTS;
+	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
+		mctrl |= TIOCM_CTS;
+	}
+	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
+		mctrl |= TIOCM_DSR;
+	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
+		mctrl |= TIOCM_CAR;
+
+	return mctrl;
+}
+
+static void sci_enable_ms(struct uart_port *port)
+{
+	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
+}
+
+static void sci_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned short scscr, scsptr;
+	unsigned long flags;
+
+	/* check whether the port has SCSPTR */
+	if (!sci_getreg(port, SCSPTR)->size) {
+		/*
+		 * Not supported by hardware. Most parts couple break and rx
+		 * interrupts together, with break detection always enabled.
+		 */
+		return;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+	scsptr = serial_port_in(port, SCSPTR);
+	scscr = serial_port_in(port, SCSCR);
+
+	if (break_state == -1) {
+		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
+		scscr &= ~SCSCR_TE;
+	} else {
+		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
+		scscr |= SCSCR_TE;
+	}
+
+	serial_port_out(port, SCSPTR, scsptr);
+	serial_port_out(port, SCSCR, scscr);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int sci_startup(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	int ret;
+
+	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+
+	sci_request_dma(port);
+
+	ret = sci_request_irq(s);
+	if (unlikely(ret < 0)) {
+		sci_free_dma(port);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void sci_shutdown(struct uart_port *port)
+{
+	struct sci_port *s = to_sci_port(port);
+	unsigned long flags;
+	u16 scr;
+
+	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+
+	s->autorts = false;
+	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
+
+	spin_lock_irqsave(&port->lock, flags);
+	sci_stop_rx(port);
+	sci_stop_tx(port);
+	/*
+	 * Stop RX and TX, disable related interrupts, keep clock source
+	 * and HSCIF TOT bits
+	 */
+	scr = serial_port_in(port, SCSCR);
+	serial_port_out(port, SCSCR, scr &
+			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
+	spin_unlock_irqrestore(&port->lock, flags);
+
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	if (s->chan_rx_saved) {
+		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
+			port->line);
+		hrtimer_cancel(&s->rx_timer);
+	}
+#endif
+
+	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
+		del_timer_sync(&s->rx_fifo_timer);
+	sci_free_irq(s);
+	sci_free_dma(port);
+}
+
+static int sci_sck_calc(struct sci_port *s, unsigned int bps,
+			unsigned int *srr)
+{
+	unsigned long freq = s->clk_rates[SCI_SCK];
+	int err, min_err = INT_MAX;
+	unsigned int sr;
+
+	if (s->port.type != PORT_HSCIF)
+		freq *= 2;
+
+	for_each_sr(sr, s) {
+		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
+		if (abs(err) >= abs(min_err))
+			continue;
+
+		min_err = err;
+		*srr = sr - 1;
+
+		if (!err)
+			break;
+	}
+
+	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
+		*srr + 1);
+	return min_err;
+}
+
+static int sci_brg_calc(struct sci_port *s, unsigned int bps,
+			unsigned long freq, unsigned int *dlr,
+			unsigned int *srr)
+{
+	int err, min_err = INT_MAX;
+	unsigned int sr, dl;
+
+	if (s->port.type != PORT_HSCIF)
+		freq *= 2;
+
+	for_each_sr(sr, s) {
+		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
+		dl = clamp(dl, 1U, 65535U);
+
+		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
+		if (abs(err) >= abs(min_err))
+			continue;
+
+		min_err = err;
+		*dlr = dl;
+		*srr = sr - 1;
+
+		if (!err)
+			break;
+	}
+
+	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
+		min_err, *dlr, *srr + 1);
+	return min_err;
+}
+
+/* calculate sample rate, BRR, and clock select */
+static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
+			  unsigned int *brr, unsigned int *srr,
+			  unsigned int *cks)
+{
+	unsigned long freq = s->clk_rates[SCI_FCK];
+	unsigned int sr, br, prediv, scrate, c;
+	int err, min_err = INT_MAX;
+
+	if (s->port.type != PORT_HSCIF)
+		freq *= 2;
+
+	/*
+	 * Find the combination of sample rate and clock select with the
+	 * smallest deviation from the desired baud rate.
+	 * Prefer high sample rates to maximise the receive margin.
+	 *
+	 * M: Receive margin (%)
+	 * N: Ratio of bit rate to clock (N = sampling rate)
+	 * D: Clock duty (D = 0 to 1.0)
+	 * L: Frame length (L = 9 to 12)
+	 * F: Absolute value of clock frequency deviation
+	 *
+	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
+	 *      (|D - 0.5| / N * (1 + F))|
+	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
+	 */
+	for_each_sr(sr, s) {
+		for (c = 0; c <= 3; c++) {
+			/* integerized formulas from HSCIF documentation */
+			prediv = sr << (2 * c + 1);
+
+			/*
+			 * We need to calculate:
+			 *
+			 *     br = freq / (prediv * bps) clamped to [1..256]
+			 *     err = freq / (br * prediv) - bps
+			 *
+			 * Watch out for overflow when calculating the desired
+			 * sampling clock rate!
+			 */
+			if (bps > UINT_MAX / prediv)
+				break;
+
+			scrate = prediv * bps;
+			br = DIV_ROUND_CLOSEST(freq, scrate);
+			br = clamp(br, 1U, 256U);
+
+			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
+			if (abs(err) >= abs(min_err))
+				continue;
+
+			min_err = err;
+			*brr = br - 1;
+			*srr = sr - 1;
+			*cks = c;
+
+			if (!err)
+				goto found;
+		}
+	}
+
+found:
+	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
+		min_err, *brr, *srr + 1, *cks);
+	return min_err;
+}
+
+static void sci_reset(struct uart_port *port)
+{
+	const struct plat_sci_reg *reg;
+	unsigned int status;
+	struct sci_port *s = to_sci_port(port);
+
+	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
+
+	reg = sci_getreg(port, SCFCR);
+	if (reg->size)
+		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
+
+	sci_clear_SCxSR(port,
+			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
+			SCxSR_BREAK_CLEAR(port));
+	if (sci_getreg(port, SCLSR)->size) {
+		status = serial_port_in(port, SCLSR);
+		status &= ~(SCLSR_TO | SCLSR_ORER);
+		serial_port_out(port, SCLSR, status);
+	}
+
+	if (s->rx_trigger > 1) {
+		if (s->rx_fifo_timeout) {
+			scif_set_rtrg(port, 1);
+			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
+		} else {
+			if (port->type == PORT_SCIFA ||
+			    port->type == PORT_SCIFB)
+				scif_set_rtrg(port, 1);
+			else
+				scif_set_rtrg(port, s->rx_trigger);
+		}
+	}
+}
+
+static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
+		            const struct ktermios *old)
+{
+	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
+	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
+	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
+	struct sci_port *s = to_sci_port(port);
+	const struct plat_sci_reg *reg;
+	int min_err = INT_MAX, err;
+	unsigned long max_freq = 0;
+	int best_clk = -1;
+	unsigned long flags;
+
+	if ((termios->c_cflag & CSIZE) == CS7) {
+		smr_val |= SCSMR_CHR;
+	} else {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+	}
+	if (termios->c_cflag & PARENB)
+		smr_val |= SCSMR_PE;
+	if (termios->c_cflag & PARODD)
+		smr_val |= SCSMR_PE | SCSMR_ODD;
+	if (termios->c_cflag & CSTOPB)
+		smr_val |= SCSMR_STOP;
+
+	/*
+	 * earlyprintk comes here early on with port->uartclk set to zero.
+	 * the clock framework is not up and running at this point so here
+	 * we assume that 115200 is the maximum baud rate. please note that
+	 * the baud rate is not programmed during earlyprintk - it is assumed
+	 * that the previous boot loader has enabled required clocks and
+	 * setup the baud rate generator hardware for us already.
+	 */
+	if (!port->uartclk) {
+		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
+		goto done;
+	}
+
+	for (i = 0; i < SCI_NUM_CLKS; i++)
+		max_freq = max(max_freq, s->clk_rates[i]);
+
+	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
+	if (!baud)
+		goto done;
+
+	/*
+	 * There can be multiple sources for the sampling clock.  Find the one
+	 * that gives us the smallest deviation from the desired baud rate.
+	 */
+
+	/* Optional Undivided External Clock */
+	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
+	    port->type != PORT_SCIFB) {
+		err = sci_sck_calc(s, baud, &srr1);
+		if (abs(err) < abs(min_err)) {
+			best_clk = SCI_SCK;
+			scr_val = SCSCR_CKE1;
+			sccks = SCCKS_CKS;
+			min_err = err;
+			srr = srr1;
+			if (!err)
+				goto done;
+		}
+	}
+
+	/* Optional BRG Frequency Divided External Clock */
+	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
+		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
+				   &srr1);
+		if (abs(err) < abs(min_err)) {
+			best_clk = SCI_SCIF_CLK;
+			scr_val = SCSCR_CKE1;
+			sccks = 0;
+			min_err = err;
+			dl = dl1;
+			srr = srr1;
+			if (!err)
+				goto done;
+		}
+	}
+
+	/* Optional BRG Frequency Divided Internal Clock */
+	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
+		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
+				   &srr1);
+		if (abs(err) < abs(min_err)) {
+			best_clk = SCI_BRG_INT;
+			scr_val = SCSCR_CKE1;
+			sccks = SCCKS_XIN;
+			min_err = err;
+			dl = dl1;
+			srr = srr1;
+			if (!min_err)
+				goto done;
+		}
+	}
+
+	/* Divided Functional Clock using standard Bit Rate Register */
+	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
+	if (abs(err) < abs(min_err)) {
+		best_clk = SCI_FCK;
+		scr_val = 0;
+		min_err = err;
+		brr = brr1;
+		srr = srr1;
+		cks = cks1;
+	}
+
+done:
+	if (best_clk >= 0)
+		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
+			s->clks[best_clk], baud, min_err);
+
+	sci_port_enable(s);
+
+	/*
+	 * Program the optional External Baud Rate Generator (BRG) first.
+	 * It controls the mux to select (H)SCK or frequency divided clock.
+	 */
+	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
+		serial_port_out(port, SCDL, dl);
+		serial_port_out(port, SCCKS, sccks);
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	sci_reset(port);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* byte size and parity */
+	bits = tty_get_frame_size(termios->c_cflag);
+
+	if (sci_getreg(port, SEMR)->size)
+		serial_port_out(port, SEMR, 0);
+
+	if (best_clk >= 0) {
+		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
+			switch (srr + 1) {
+			case 5:  smr_val |= SCSMR_SRC_5;  break;
+			case 7:  smr_val |= SCSMR_SRC_7;  break;
+			case 11: smr_val |= SCSMR_SRC_11; break;
+			case 13: smr_val |= SCSMR_SRC_13; break;
+			case 16: smr_val |= SCSMR_SRC_16; break;
+			case 17: smr_val |= SCSMR_SRC_17; break;
+			case 19: smr_val |= SCSMR_SRC_19; break;
+			case 27: smr_val |= SCSMR_SRC_27; break;
+			}
+		smr_val |= cks;
+		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
+		serial_port_out(port, SCSMR, smr_val);
+		serial_port_out(port, SCBRR, brr);
+		if (sci_getreg(port, HSSRR)->size) {
+			unsigned int hssrr = srr | HSCIF_SRE;
+			/* Calculate deviation from intended rate at the
+			 * center of the last stop bit in sampling clocks.
+			 */
+			int last_stop = bits * 2 - 1;
+			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
+							  (int)(srr + 1),
+							  2 * (int)baud);
+
+			if (abs(deviation) >= 2) {
+				/* At least two sampling clocks off at the
+				 * last stop bit; we can increase the error
+				 * margin by shifting the sampling point.
+				 */
+				int shift = clamp(deviation / 2, -8, 7);
+
+				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
+					 HSCIF_SRHP_MASK;
+				hssrr |= HSCIF_SRDE;
+			}
+			serial_port_out(port, HSSRR, hssrr);
+		}
+
+		/* Wait one bit interval */
+		udelay((1000000 + (baud - 1)) / baud);
+	} else {
+		/* Don't touch the bit rate configuration */
+		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
+		smr_val |= serial_port_in(port, SCSMR) &
+			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
+		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
+		serial_port_out(port, SCSMR, smr_val);
+	}
+
+	sci_init_pins(port, termios->c_cflag);
+
+	port->status &= ~UPSTAT_AUTOCTS;
+	s->autorts = false;
+	reg = sci_getreg(port, SCFCR);
+	if (reg->size) {
+		unsigned short ctrl = serial_port_in(port, SCFCR);
+
+		if ((port->flags & UPF_HARD_FLOW) &&
+		    (termios->c_cflag & CRTSCTS)) {
+			/* There is no CTS interrupt to restart the hardware */
+			port->status |= UPSTAT_AUTOCTS;
+			/* MCE is enabled when RTS is raised */
+			s->autorts = true;
+		}
+
+		/*
+		 * As we've done a sci_reset() above, ensure we don't
+		 * interfere with the FIFOs while toggling MCE. As the
+		 * reset values could still be set, simply mask them out.
+		 */
+		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
+
+		serial_port_out(port, SCFCR, ctrl);
+	}
+	if (port->flags & UPF_HARD_FLOW) {
+		/* Refresh (Auto) RTS */
+		sci_set_mctrl(port, port->mctrl);
+	}
+
+	/*
+	 * For SCI, TE (transmit enable) must be set after setting TIE
+	 * (transmit interrupt enable) or in the same instruction to
+	 * start the transmitting process. So skip setting TE here for SCI.
+	 */
+	if (port->type != PORT_SCI)
+		scr_val |= SCSCR_TE;
+	scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
+	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
+	if ((srr + 1 == 5) &&
+	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
+		/*
+		 * In asynchronous mode, when the sampling rate is 1/5, first
+		 * received data may become invalid on some SCIFA and SCIFB.
+		 * To avoid this problem wait more than 1 serial data time (1
+		 * bit time x serial data number) after setting SCSCR.RE = 1.
+		 */
+		udelay(DIV_ROUND_UP(10 * 1000000, baud));
+	}
+
+	/* Calculate delay for 2 DMA buffers (4 FIFO). */
+	s->rx_frame = (10000 * bits) / (baud / 100);
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
+#endif
+
+	if ((termios->c_cflag & CREAD) != 0)
+		sci_start_rx(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	sci_port_disable(s);
+
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		sci_enable_ms(port);
+}
+
+static void sci_pm(struct uart_port *port, unsigned int state,
+		   unsigned int oldstate)
+{
+	struct sci_port *sci_port = to_sci_port(port);
+
+	switch (state) {
+	case UART_PM_STATE_OFF:
+		sci_port_disable(sci_port);
+		break;
+	default:
+		sci_port_enable(sci_port);
+		break;
+	}
+}
+
+static const char *sci_type(struct uart_port *port)
+{
+	switch (port->type) {
+	case PORT_IRDA:
+		return "irda";
+	case PORT_SCI:
+		return "sci";
+	case PORT_SCIF:
+		return "scif";
+	case PORT_SCIFA:
+		return "scifa";
+	case PORT_SCIFB:
+		return "scifb";
+	case PORT_HSCIF:
+		return "hscif";
+	}
+
+	return NULL;
+}
+
+static int sci_remap_port(struct uart_port *port)
+{
+	struct sci_port *sport = to_sci_port(port);
+
+	/*
+	 * Nothing to do if there's already an established membase.
+	 */
+	if (port->membase)
+		return 0;
+
+	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
+		port->membase = ioremap(port->mapbase, sport->reg_size);
+		if (unlikely(!port->membase)) {
+			dev_err(port->dev, "can't remap port#%d\n", port->line);
+			return -ENXIO;
+		}
+	} else {
+		/*
+		 * For the simple (and majority of) cases where we don't
+		 * need to do any remapping, just cast the cookie
+		 * directly.
+		 */
+		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
+	}
+
+	return 0;
+}
+
+static void sci_release_port(struct uart_port *port)
+{
+	struct sci_port *sport = to_sci_port(port);
+
+	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
+		iounmap(port->membase);
+		port->membase = NULL;
+	}
+
+	release_mem_region(port->mapbase, sport->reg_size);
+}
+
+static int sci_request_port(struct uart_port *port)
+{
+	struct resource *res;
+	struct sci_port *sport = to_sci_port(port);
+	int ret;
+
+	res = request_mem_region(port->mapbase, sport->reg_size,
+				 dev_name(port->dev));
+	if (unlikely(res == NULL)) {
+		dev_err(port->dev, "request_mem_region failed.");
+		return -EBUSY;
+	}
+
+	ret = sci_remap_port(port);
+	if (unlikely(ret != 0)) {
+		release_resource(res);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void sci_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		struct sci_port *sport = to_sci_port(port);
+
+		port->type = sport->cfg->type;
+		sci_request_port(port);
+	}
+}
+
+static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (ser->baud_base < 2400)
+		/* No paper tape reader for Mitch.. */
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops sci_uart_ops = {
+	.tx_empty	= sci_tx_empty,
+	.set_mctrl	= sci_set_mctrl,
+	.get_mctrl	= sci_get_mctrl,
+	.start_tx	= sci_start_tx,
+	.stop_tx	= sci_stop_tx,
+	.stop_rx	= sci_stop_rx,
+	.enable_ms	= sci_enable_ms,
+	.break_ctl	= sci_break_ctl,
+	.startup	= sci_startup,
+	.shutdown	= sci_shutdown,
+	.flush_buffer	= sci_flush_buffer,
+	.set_termios	= sci_set_termios,
+	.pm		= sci_pm,
+	.type		= sci_type,
+	.release_port	= sci_release_port,
+	.request_port	= sci_request_port,
+	.config_port	= sci_config_port,
+	.verify_port	= sci_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= sci_poll_get_char,
+	.poll_put_char	= sci_poll_put_char,
+#endif
+};
+
+static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
+{
+	const char *clk_names[] = {
+		[SCI_FCK] = "fck",
+		[SCI_SCK] = "sck",
+		[SCI_BRG_INT] = "brg_int",
+		[SCI_SCIF_CLK] = "scif_clk",
+	};
+	struct clk *clk;
+	unsigned int i;
+
+	if (sci_port->cfg->type == PORT_HSCIF)
+		clk_names[SCI_SCK] = "hsck";
+
+	for (i = 0; i < SCI_NUM_CLKS; i++) {
+		clk = devm_clk_get_optional(dev, clk_names[i]);
+		if (IS_ERR(clk))
+			return PTR_ERR(clk);
+
+		if (!clk && i == SCI_FCK) {
+			/*
+			 * Not all SH platforms declare a clock lookup entry
+			 * for SCI devices, in which case we need to get the
+			 * global "peripheral_clk" clock.
+			 */
+			clk = devm_clk_get(dev, "peripheral_clk");
+			if (IS_ERR(clk))
+				return dev_err_probe(dev, PTR_ERR(clk),
+						     "failed to get %s\n",
+						     clk_names[i]);
+		}
+
+		if (!clk)
+			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
+		else
+			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
+				clk, clk_get_rate(clk));
+		sci_port->clks[i] = clk;
+	}
+	return 0;
+}
+
+static const struct sci_port_params *
+sci_probe_regmap(const struct plat_sci_port *cfg)
+{
+	unsigned int regtype;
+
+	if (cfg->regtype != SCIx_PROBE_REGTYPE)
+		return &sci_port_params[cfg->regtype];
+
+	switch (cfg->type) {
+	case PORT_SCI:
+		regtype = SCIx_SCI_REGTYPE;
+		break;
+	case PORT_IRDA:
+		regtype = SCIx_IRDA_REGTYPE;
+		break;
+	case PORT_SCIFA:
+		regtype = SCIx_SCIFA_REGTYPE;
+		break;
+	case PORT_SCIFB:
+		regtype = SCIx_SCIFB_REGTYPE;
+		break;
+	case PORT_SCIF:
+		/*
+		 * The SH-4 is a bit of a misnomer here, although that's
+		 * where this particular port layout originated. This
+		 * configuration (or some slight variation thereof)
+		 * remains the dominant model for all SCIFs.
+		 */
+		regtype = SCIx_SH4_SCIF_REGTYPE;
+		break;
+	case PORT_HSCIF:
+		regtype = SCIx_HSCIF_REGTYPE;
+		break;
+	default:
+		pr_err("Can't probe register map for given port\n");
+		return NULL;
+	}
+
+	return &sci_port_params[regtype];
+}
+
+static int sci_init_single(struct platform_device *dev,
+			   struct sci_port *sci_port, unsigned int index,
+			   const struct plat_sci_port *p, bool early)
+{
+	struct uart_port *port = &sci_port->port;
+	const struct resource *res;
+	unsigned int i;
+	int ret;
+
+	sci_port->cfg	= p;
+
+	port->ops	= &sci_uart_ops;
+	port->iotype	= UPIO_MEM;
+	port->line	= index;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (res == NULL)
+		return -ENOMEM;
+
+	port->mapbase = res->start;
+	sci_port->reg_size = resource_size(res);
+
+	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
+		if (i)
+			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
+		else
+			sci_port->irqs[i] = platform_get_irq(dev, i);
+	}
+
+	/*
+	 * The fourth interrupt on SCI port is transmit end interrupt, so
+	 * shuffle the interrupts.
+	 */
+	if (p->type == PORT_SCI)
+		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
+
+	/* The SCI generates several interrupts. They can be muxed together or
+	 * connected to different interrupt lines. In the muxed case only one
+	 * interrupt resource is specified as there is only one interrupt ID.
+	 * In the non-muxed case, up to 6 interrupt signals might be generated
+	 * from the SCI, however those signals might have their own individual
+	 * interrupt ID numbers, or muxed together with another interrupt.
+	 */
+	if (sci_port->irqs[0] < 0)
+		return -ENXIO;
+
+	if (sci_port->irqs[1] < 0)
+		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
+			sci_port->irqs[i] = sci_port->irqs[0];
+
+	sci_port->params = sci_probe_regmap(p);
+	if (unlikely(sci_port->params == NULL))
+		return -EINVAL;
+
+	switch (p->type) {
+	case PORT_SCIFB:
+		sci_port->rx_trigger = 48;
+		break;
+	case PORT_HSCIF:
+		sci_port->rx_trigger = 64;
+		break;
+	case PORT_SCIFA:
+		sci_port->rx_trigger = 32;
+		break;
+	case PORT_SCIF:
+		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
+			/* RX triggering not implemented for this IP */
+			sci_port->rx_trigger = 1;
+		else
+			sci_port->rx_trigger = 8;
+		break;
+	default:
+		sci_port->rx_trigger = 1;
+		break;
+	}
+
+	sci_port->rx_fifo_timeout = 0;
+	sci_port->hscif_tot = 0;
+
+	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
+	 * match the SoC datasheet, this should be investigated. Let platform
+	 * data override the sampling rate for now.
+	 */
+	sci_port->sampling_rate_mask = p->sampling_rate
+				     ? SCI_SR(p->sampling_rate)
+				     : sci_port->params->sampling_rate_mask;
+
+	if (!early) {
+		ret = sci_init_clocks(sci_port, &dev->dev);
+		if (ret < 0)
+			return ret;
+
+		port->dev = &dev->dev;
+
+		pm_runtime_enable(&dev->dev);
+	}
+
+	port->type		= p->type;
+	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
+	port->fifosize		= sci_port->params->fifosize;
+
+	if (port->type == PORT_SCI && !dev->dev.of_node) {
+		if (sci_port->reg_size >= 0x20)
+			port->regshift = 2;
+		else
+			port->regshift = 1;
+	}
+
+	/*
+	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
+	 * for the multi-IRQ ports, which is where we are primarily
+	 * concerned with the shutdown path synchronization.
+	 *
+	 * For the muxed case there's nothing more to do.
+	 */
+	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
+	port->irqflags		= 0;
+
+	port->serial_in		= sci_serial_in;
+	port->serial_out	= sci_serial_out;
+
+	return 0;
+}
+
+static void sci_cleanup_single(struct sci_port *port)
+{
+	pm_runtime_disable(port->port.dev);
+}
+
+#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
+    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
+static void serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	sci_poll_put_char(port, ch);
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ */
+static void serial_console_write(struct console *co, const char *s,
+				 unsigned count)
+{
+	struct sci_port *sci_port = &sci_ports[co->index];
+	struct uart_port *port = &sci_port->port;
+	unsigned short bits, ctrl, ctrl_temp;
+	unsigned long flags;
+	int locked = 1;
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/* first save SCSCR then disable interrupts, keep clock source */
+	ctrl = serial_port_in(port, SCSCR);
+	ctrl_temp = SCSCR_RE | SCSCR_TE |
+		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
+		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
+	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
+
+	uart_console_write(port, s, count, serial_console_putchar);
+
+	/* wait until fifo is empty and last bit has been transmitted */
+	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
+	while ((serial_port_in(port, SCxSR) & bits) != bits)
+		cpu_relax();
+
+	/* restore the SCSCR */
+	serial_port_out(port, SCSCR, ctrl);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int serial_console_setup(struct console *co, char *options)
+{
+	struct sci_port *sci_port;
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	/*
+	 * Refuse to handle any bogus ports.
+	 */
+	if (co->index < 0 || co->index >= SCI_NPORTS)
+		return -ENODEV;
+
+	sci_port = &sci_ports[co->index];
+	port = &sci_port->port;
+
+	/*
+	 * Refuse to handle uninitialized ports.
+	 */
+	if (!port->ops)
+		return -ENODEV;
+
+	ret = sci_remap_port(port);
+	if (unlikely(ret != 0))
+		return ret;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console serial_console = {
+	.name		= "ttySC",
+	.device		= uart_console_device,
+	.write		= serial_console_write,
+	.setup		= serial_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &sci_uart_driver,
+};
+
+#ifdef CONFIG_SUPERH
+static char early_serial_buf[32];
+
+static int early_serial_console_setup(struct console *co, char *options)
+{
+	/*
+	 * This early console is always registered using the earlyprintk=
+	 * parameter, which does not call add_preferred_console(). Thus
+	 * @options is always NULL and the options for this early console
+	 * are passed using a custom buffer.
+	 */
+	WARN_ON(options);
+
+	return serial_console_setup(co, early_serial_buf);
+}
+
+static struct console early_serial_console = {
+	.name           = "early_ttySC",
+	.write          = serial_console_write,
+	.setup		= early_serial_console_setup,
+	.flags          = CON_PRINTBUFFER,
+	.index		= -1,
+};
+
+static int sci_probe_earlyprintk(struct platform_device *pdev)
+{
+	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
+
+	if (early_serial_console.data)
+		return -EEXIST;
+
+	early_serial_console.index = pdev->id;
+
+	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
+
+	if (!strstr(early_serial_buf, "keep"))
+		early_serial_console.flags |= CON_BOOT;
+
+	register_console(&early_serial_console);
+	return 0;
+}
+#endif
+
+#define SCI_CONSOLE	(&serial_console)
+
+#else
+static inline int sci_probe_earlyprintk(struct platform_device *pdev)
+{
+	return -EINVAL;
+}
+
+#define SCI_CONSOLE	NULL
+
+#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
+
+static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
+
+static DEFINE_MUTEX(sci_uart_registration_lock);
+static struct uart_driver sci_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "sci",
+	.dev_name	= "ttySC",
+	.major		= SCI_MAJOR,
+	.minor		= SCI_MINOR_START,
+	.nr		= SCI_NPORTS,
+	.cons		= SCI_CONSOLE,
+};
+
+static int sci_remove(struct platform_device *dev)
+{
+	struct sci_port *port = platform_get_drvdata(dev);
+	unsigned int type = port->port.type;	/* uart_remove_... clears it */
+
+	sci_ports_in_use &= ~BIT(port->port.line);
+	uart_remove_one_port(&sci_uart_driver, &port->port);
+
+	sci_cleanup_single(port);
+
+	if (port->port.fifosize > 1)
+		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
+	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
+		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
+
+	return 0;
+}
+
+
+#define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
+#define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
+#define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
+
+static const struct of_device_id of_sci_match[] __maybe_unused = {
+	/* SoC-specific types */
+	{
+		.compatible = "renesas,scif-r7s72100",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
+	},
+	{
+		.compatible = "renesas,scif-r7s9210",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
+	},
+	{
+		.compatible = "renesas,scif-r9a07g044",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
+	},
+	/* Family-specific types */
+	{
+		.compatible = "renesas,rcar-gen1-scif",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
+	}, {
+		.compatible = "renesas,rcar-gen2-scif",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
+	}, {
+		.compatible = "renesas,rcar-gen3-scif",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
+	}, {
+		.compatible = "renesas,rcar-gen4-scif",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
+	},
+	/* Generic types */
+	{
+		.compatible = "renesas,scif",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
+	}, {
+		.compatible = "renesas,scifa",
+		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
+	}, {
+		.compatible = "renesas,scifb",
+		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
+	}, {
+		.compatible = "renesas,hscif",
+		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
+	}, {
+		.compatible = "renesas,sci",
+		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
+	}, {
+		/* Terminator */
+	},
+};
+MODULE_DEVICE_TABLE(of, of_sci_match);
+
+static void sci_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
+					  unsigned int *dev_id)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct reset_control *rstc;
+	struct plat_sci_port *p;
+	struct sci_port *sp;
+	const void *data;
+	int id, ret;
+
+	if (!IS_ENABLED(CONFIG_OF) || !np)
+		return ERR_PTR(-EINVAL);
+
+	data = of_device_get_match_data(&pdev->dev);
+
+	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(rstc))
+		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
+					     "failed to get reset ctrl\n"));
+
+	ret = reset_control_deassert(rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
+			ret);
+		return ERR_PTR(ret);
+	}
+
+	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
+	if (!p)
+		return ERR_PTR(-ENOMEM);
+
+	/* Get the line number from the aliases node. */
+	id = of_alias_get_id(np, "serial");
+	if (id < 0 && ~sci_ports_in_use)
+		id = ffz(sci_ports_in_use);
+	if (id < 0) {
+		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
+		return ERR_PTR(-EINVAL);
+	}
+	if (id >= ARRAY_SIZE(sci_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n", id);
+		return ERR_PTR(-EINVAL);
+	}
+
+	sp = &sci_ports[id];
+	*dev_id = id;
+
+	p->type = SCI_OF_TYPE(data);
+	p->regtype = SCI_OF_REGTYPE(data);
+
+	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
+
+	return p;
+}
+
+static int sci_probe_single(struct platform_device *dev,
+				      unsigned int index,
+				      struct plat_sci_port *p,
+				      struct sci_port *sciport)
+{
+	int ret;
+
+	/* Sanity check */
+	if (unlikely(index >= SCI_NPORTS)) {
+		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
+			   index+1, SCI_NPORTS);
+		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
+		return -EINVAL;
+	}
+	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
+	if (sci_ports_in_use & BIT(index))
+		return -EBUSY;
+
+	mutex_lock(&sci_uart_registration_lock);
+	if (!sci_uart_driver.state) {
+		ret = uart_register_driver(&sci_uart_driver);
+		if (ret) {
+			mutex_unlock(&sci_uart_registration_lock);
+			return ret;
+		}
+	}
+	mutex_unlock(&sci_uart_registration_lock);
+
+	ret = sci_init_single(dev, sciport, index, p, false);
+	if (ret)
+		return ret;
+
+	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
+	if (IS_ERR(sciport->gpios))
+		return PTR_ERR(sciport->gpios);
+
+	if (sciport->has_rtscts) {
+		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
+		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
+			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
+			return -EINVAL;
+		}
+		sciport->port.flags |= UPF_HARD_FLOW;
+	}
+
+	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
+	if (ret) {
+		sci_cleanup_single(sciport);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int sci_probe(struct platform_device *dev)
+{
+	struct plat_sci_port *p;
+	struct sci_port *sp;
+	unsigned int dev_id;
+	int ret;
+
+	/*
+	 * If we've come here via earlyprintk initialization, head off to
+	 * the special early probe. We don't have sufficient device state
+	 * to make it beyond this yet.
+	 */
+#ifdef CONFIG_SUPERH
+	if (is_sh_early_platform_device(dev))
+		return sci_probe_earlyprintk(dev);
+#endif
+
+	if (dev->dev.of_node) {
+		p = sci_parse_dt(dev, &dev_id);
+		if (IS_ERR(p))
+			return PTR_ERR(p);
+	} else {
+		p = dev->dev.platform_data;
+		if (p == NULL) {
+			dev_err(&dev->dev, "no platform data supplied\n");
+			return -EINVAL;
+		}
+
+		dev_id = dev->id;
+	}
+
+	sp = &sci_ports[dev_id];
+	platform_set_drvdata(dev, sp);
+
+	ret = sci_probe_single(dev, dev_id, p, sp);
+	if (ret)
+		return ret;
+
+	if (sp->port.fifosize > 1) {
+		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
+		if (ret)
+			return ret;
+	}
+	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
+	    sp->port.type == PORT_HSCIF) {
+		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
+		if (ret) {
+			if (sp->port.fifosize > 1) {
+				device_remove_file(&dev->dev,
+						   &dev_attr_rx_fifo_trigger);
+			}
+			return ret;
+		}
+	}
+
+#ifdef CONFIG_SH_STANDARD_BIOS
+	sh_bios_gdb_detach();
+#endif
+
+	sci_ports_in_use |= BIT(dev_id);
+	return 0;
+}
+
+static __maybe_unused int sci_suspend(struct device *dev)
+{
+	struct sci_port *sport = dev_get_drvdata(dev);
+
+	if (sport)
+		uart_suspend_port(&sci_uart_driver, &sport->port);
+
+	return 0;
+}
+
+static __maybe_unused int sci_resume(struct device *dev)
+{
+	struct sci_port *sport = dev_get_drvdata(dev);
+
+	if (sport)
+		uart_resume_port(&sci_uart_driver, &sport->port);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
+
+static struct platform_driver sci_driver = {
+	.probe		= sci_probe,
+	.remove		= sci_remove,
+	.driver		= {
+		.name	= "sh-sci",
+		.pm	= &sci_dev_pm_ops,
+		.of_match_table = of_match_ptr(of_sci_match),
+	},
+};
+
+static int __init sci_init(void)
+{
+	pr_info("%s\n", banner);
+
+	return platform_driver_register(&sci_driver);
+}
+
+static void __exit sci_exit(void)
+{
+	platform_driver_unregister(&sci_driver);
+
+	if (sci_uart_driver.state)
+		uart_unregister_driver(&sci_uart_driver);
+}
+
+#if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
+sh_early_platform_init_buffer("earlyprintk", &sci_driver,
+			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
+#endif
+#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
+static struct plat_sci_port port_cfg __initdata;
+
+static int __init early_console_setup(struct earlycon_device *device,
+				      int type)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.serial_in = sci_serial_in;
+	device->port.serial_out	= sci_serial_out;
+	device->port.type = type;
+	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
+	port_cfg.type = type;
+	sci_ports[0].cfg = &port_cfg;
+	sci_ports[0].params = sci_probe_regmap(&port_cfg);
+	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
+	sci_serial_out(&sci_ports[0].port, SCSCR,
+		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
+
+	device->con->write = serial_console_write;
+	return 0;
+}
+static int __init sci_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCI);
+}
+static int __init scif_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCIF);
+}
+static int __init rzscifa_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
+	return early_console_setup(device, PORT_SCIF);
+}
+
+static int __init scifa_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCIFA);
+}
+static int __init scifb_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCIFB);
+}
+static int __init hscif_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_HSCIF);
+}
+
+OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
+OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
+OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
+OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
+OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
+OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
+OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
+#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
+
+module_init(sci_init);
+module_exit(sci_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sh-sci");
+MODULE_AUTHOR("Paul Mundt");
+MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
diff --git a/drivers/tty/serial/sh-sci.h b/drivers/tty/serial/sh-sci.h
new file mode 100644
index 000000000..0b65563c4
--- /dev/null
+++ b/drivers/tty/serial/sh-sci.h
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/bitops.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+
+#define SCI_MAJOR		204
+#define SCI_MINOR_START		8
+
+
+/*
+ * SCI register subset common for all port types.
+ * Not all registers will exist on all parts.
+ */
+enum {
+	SCSMR,				/* Serial Mode Register */
+	SCBRR,				/* Bit Rate Register */
+	SCSCR,				/* Serial Control Register */
+	SCxSR,				/* Serial Status Register */
+	SCFCR,				/* FIFO Control Register */
+	SCFDR,				/* FIFO Data Count Register */
+	SCxTDR,				/* Transmit (FIFO) Data Register */
+	SCxRDR,				/* Receive (FIFO) Data Register */
+	SCLSR,				/* Line Status Register */
+	SCTFDR,				/* Transmit FIFO Data Count Register */
+	SCRFDR,				/* Receive FIFO Data Count Register */
+	SCSPTR,				/* Serial Port Register */
+	HSSRR,				/* Sampling Rate Register */
+	SCPCR,				/* Serial Port Control Register */
+	SCPDR,				/* Serial Port Data Register */
+	SCDL,				/* BRG Frequency Division Register */
+	SCCKS,				/* BRG Clock Select Register */
+	HSRTRGR,			/* Rx FIFO Data Count Trigger Register */
+	HSTTRGR,			/* Tx FIFO Data Count Trigger Register */
+	SEMR,				/* Serial extended mode register */
+
+	SCIx_NR_REGS,
+};
+
+
+/* SCSMR (Serial Mode Register) */
+#define SCSMR_C_A	BIT(7)	/* Communication Mode */
+#define SCSMR_CSYNC	BIT(7)	/*   - Clocked synchronous mode */
+#define SCSMR_ASYNC	0	/*   - Asynchronous mode */
+#define SCSMR_CHR	BIT(6)	/* 7-bit Character Length */
+#define SCSMR_PE	BIT(5)	/* Parity Enable */
+#define SCSMR_ODD	BIT(4)	/* Odd Parity */
+#define SCSMR_STOP	BIT(3)	/* Stop Bit Length */
+#define SCSMR_CKS	0x0003	/* Clock Select */
+
+/* Serial Mode Register, SCIFA/SCIFB only bits */
+#define SCSMR_CKEDG	BIT(12)	/* Transmit/Receive Clock Edge Select */
+#define SCSMR_SRC_MASK	0x0700	/* Sampling Control */
+#define SCSMR_SRC_16	0x0000	/* Sampling rate 1/16 */
+#define SCSMR_SRC_5	0x0100	/* Sampling rate 1/5 */
+#define SCSMR_SRC_7	0x0200	/* Sampling rate 1/7 */
+#define SCSMR_SRC_11	0x0300	/* Sampling rate 1/11 */
+#define SCSMR_SRC_13	0x0400	/* Sampling rate 1/13 */
+#define SCSMR_SRC_17	0x0500	/* Sampling rate 1/17 */
+#define SCSMR_SRC_19	0x0600	/* Sampling rate 1/19 */
+#define SCSMR_SRC_27	0x0700	/* Sampling rate 1/27 */
+
+/* Serial Control Register, SCI only bits */
+#define SCSCR_TEIE	BIT(2)  /* Transmit End Interrupt Enable */
+
+/* Serial Control Register, SCIFA/SCIFB only bits */
+#define SCSCR_TDRQE	BIT(15)	/* Tx Data Transfer Request Enable */
+#define SCSCR_RDRQE	BIT(14)	/* Rx Data Transfer Request Enable */
+
+/* Serial Control Register, HSCIF-only bits */
+#define HSSCR_TOT_SHIFT	14
+
+/* SCxSR (Serial Status Register) on SCI */
+#define SCI_TDRE	BIT(7)	/* Transmit Data Register Empty */
+#define SCI_RDRF	BIT(6)	/* Receive Data Register Full */
+#define SCI_ORER	BIT(5)	/* Overrun Error */
+#define SCI_FER		BIT(4)	/* Framing Error */
+#define SCI_PER		BIT(3)	/* Parity Error */
+#define SCI_TEND	BIT(2)	/* Transmit End */
+#define SCI_RESERVED	0x03	/* All reserved bits */
+
+#define SCI_DEFAULT_ERROR_MASK (SCI_PER | SCI_FER)
+
+#define SCI_RDxF_CLEAR	(u32)(~(SCI_RESERVED | SCI_RDRF))
+#define SCI_ERROR_CLEAR	(u32)(~(SCI_RESERVED | SCI_PER | SCI_FER | SCI_ORER))
+#define SCI_TDxE_CLEAR	(u32)(~(SCI_RESERVED | SCI_TEND | SCI_TDRE))
+#define SCI_BREAK_CLEAR	(u32)(~(SCI_RESERVED | SCI_PER | SCI_FER | SCI_ORER))
+
+/* SCxSR (Serial Status Register) on SCIF, SCIFA, SCIFB, HSCIF */
+#define SCIF_ER		BIT(7)	/* Receive Error */
+#define SCIF_TEND	BIT(6)	/* Transmission End */
+#define SCIF_TDFE	BIT(5)	/* Transmit FIFO Data Empty */
+#define SCIF_BRK	BIT(4)	/* Break Detect */
+#define SCIF_FER	BIT(3)	/* Framing Error */
+#define SCIF_PER	BIT(2)	/* Parity Error */
+#define SCIF_RDF	BIT(1)	/* Receive FIFO Data Full */
+#define SCIF_DR		BIT(0)	/* Receive Data Ready */
+/* SCIF only (optional) */
+#define SCIF_PERC	0xf000	/* Number of Parity Errors */
+#define SCIF_FERC	0x0f00	/* Number of Framing Errors */
+/*SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 only */
+#define SCIFA_ORER	BIT(9)	/* Overrun Error */
+
+#define SCIF_DEFAULT_ERROR_MASK (SCIF_PER | SCIF_FER | SCIF_BRK | SCIF_ER)
+
+#define SCIF_RDxF_CLEAR		(u32)(~(SCIF_DR | SCIF_RDF))
+#define SCIF_ERROR_CLEAR	(u32)(~(SCIF_PER | SCIF_FER | SCIF_ER))
+#define SCIF_TDxE_CLEAR		(u32)(~(SCIF_TDFE))
+#define SCIF_BREAK_CLEAR	(u32)(~(SCIF_PER | SCIF_FER | SCIF_BRK))
+
+/* SCFCR (FIFO Control Register) */
+#define SCFCR_RTRG1	BIT(7)	/* Receive FIFO Data Count Trigger */
+#define SCFCR_RTRG0	BIT(6)
+#define SCFCR_TTRG1	BIT(5)	/* Transmit FIFO Data Count Trigger */
+#define SCFCR_TTRG0	BIT(4)
+#define SCFCR_MCE	BIT(3)	/* Modem Control Enable */
+#define SCFCR_TFRST	BIT(2)	/* Transmit FIFO Data Register Reset */
+#define SCFCR_RFRST	BIT(1)	/* Receive FIFO Data Register Reset */
+#define SCFCR_LOOP	BIT(0)	/* Loopback Test */
+
+/* SCLSR (Line Status Register) on (H)SCIF */
+#define SCLSR_TO	BIT(2)	/* Timeout */
+#define SCLSR_ORER	BIT(0)	/* Overrun Error */
+
+/* SCSPTR (Serial Port Register), optional */
+#define SCSPTR_RTSIO	BIT(7)	/* Serial Port RTS# Pin Input/Output */
+#define SCSPTR_RTSDT	BIT(6)	/* Serial Port RTS# Pin Data */
+#define SCSPTR_CTSIO	BIT(5)	/* Serial Port CTS# Pin Input/Output */
+#define SCSPTR_CTSDT	BIT(4)	/* Serial Port CTS# Pin Data */
+#define SCSPTR_SCKIO	BIT(3)	/* Serial Port Clock Pin Input/Output */
+#define SCSPTR_SCKDT	BIT(2)	/* Serial Port Clock Pin Data */
+#define SCSPTR_SPB2IO	BIT(1)	/* Serial Port Break Input/Output */
+#define SCSPTR_SPB2DT	BIT(0)	/* Serial Port Break Data */
+
+/* HSSRR HSCIF */
+#define HSCIF_SRE	BIT(15)	/* Sampling Rate Register Enable */
+#define HSCIF_SRDE	BIT(14) /* Sampling Point Register Enable */
+
+#define HSCIF_SRHP_SHIFT	8
+#define HSCIF_SRHP_MASK		0x0f00
+
+/* SCPCR (Serial Port Control Register), SCIFA/SCIFB only */
+#define SCPCR_RTSC	BIT(4)	/* Serial Port RTS# Pin / Output Pin */
+#define SCPCR_CTSC	BIT(3)	/* Serial Port CTS# Pin / Input Pin */
+#define SCPCR_SCKC	BIT(2)	/* Serial Port SCK Pin / Output Pin */
+#define SCPCR_RXDC	BIT(1)	/* Serial Port RXD Pin / Input Pin */
+#define SCPCR_TXDC	BIT(0)	/* Serial Port TXD Pin / Output Pin */
+
+/* SCPDR (Serial Port Data Register), SCIFA/SCIFB only */
+#define SCPDR_RTSD	BIT(4)	/* Serial Port RTS# Output Pin Data */
+#define SCPDR_CTSD	BIT(3)	/* Serial Port CTS# Input Pin Data */
+#define SCPDR_SCKD	BIT(2)	/* Serial Port SCK Output Pin Data */
+#define SCPDR_RXDD	BIT(1)	/* Serial Port RXD Input Pin Data */
+#define SCPDR_TXDD	BIT(0)	/* Serial Port TXD Output Pin Data */
+
+/*
+ * BRG Clock Select Register (Some SCIF and HSCIF)
+ * The Baud Rate Generator for external clock can provide a clock source for
+ * the sampling clock. It outputs either its frequency divided clock, or the
+ * (undivided) (H)SCK external clock.
+ */
+#define SCCKS_CKS	BIT(15)	/* Select (H)SCK (1) or divided SC_CLK (0) */
+#define SCCKS_XIN	BIT(14)	/* SC_CLK uses bus clock (1) or SCIF_CLK (0) */
+
+#define SCxSR_TEND(port)	(((port)->type == PORT_SCI) ? SCI_TEND   : SCIF_TEND)
+#define SCxSR_RDxF(port)	(((port)->type == PORT_SCI) ? SCI_RDRF   : SCIF_DR | SCIF_RDF)
+#define SCxSR_TDxE(port)	(((port)->type == PORT_SCI) ? SCI_TDRE   : SCIF_TDFE)
+#define SCxSR_FER(port)		(((port)->type == PORT_SCI) ? SCI_FER    : SCIF_FER)
+#define SCxSR_PER(port)		(((port)->type == PORT_SCI) ? SCI_PER    : SCIF_PER)
+#define SCxSR_BRK(port)		(((port)->type == PORT_SCI) ? 0x00       : SCIF_BRK)
+
+#define SCxSR_ERRORS(port)	(to_sci_port(port)->params->error_mask)
+
+#define SCxSR_RDxF_CLEAR(port) \
+	(((port)->type == PORT_SCI) ? SCI_RDxF_CLEAR : SCIF_RDxF_CLEAR)
+#define SCxSR_ERROR_CLEAR(port) \
+	(to_sci_port(port)->params->error_clear)
+#define SCxSR_TDxE_CLEAR(port) \
+	(((port)->type == PORT_SCI) ? SCI_TDxE_CLEAR : SCIF_TDxE_CLEAR)
+#define SCxSR_BREAK_CLEAR(port) \
+	(((port)->type == PORT_SCI) ? SCI_BREAK_CLEAR : SCIF_BREAK_CLEAR)
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
new file mode 100644
index 000000000..d195c5de5
--- /dev/null
+++ b/drivers/tty/serial/sifive.c
@@ -0,0 +1,1087 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SiFive UART driver
+ * Copyright (C) 2018 Paul Walmsley <paul@pwsan.com>
+ * Copyright (C) 2018-2019 SiFive
+ *
+ * Based partially on:
+ * - drivers/tty/serial/pxa.c
+ * - drivers/tty/serial/amba-pl011.c
+ * - drivers/tty/serial/uartlite.c
+ * - drivers/tty/serial/omap-serial.c
+ * - drivers/pwm/pwm-sifive.c
+ *
+ * See the following sources for further documentation:
+ * - Chapter 19 "Universal Asynchronous Receiver/Transmitter (UART)" of
+ *   SiFive FE310-G000 v2p3
+ * - The tree/master/src/main/scala/devices/uart directory of
+ *   https://github.com/sifive/sifive-blocks/
+ *
+ * The SiFive UART design is not 8250-compatible.  The following common
+ * features are not supported:
+ * - Word lengths other than 8 bits
+ * - Break handling
+ * - Parity
+ * - Flow control
+ * - Modem signals (DSR, RI, etc.)
+ * On the other hand, the design is free from the baggage of the 8250
+ * programming model.
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/*
+ * Register offsets
+ */
+
+/* TXDATA */
+#define SIFIVE_SERIAL_TXDATA_OFFS		0x0
+#define SIFIVE_SERIAL_TXDATA_FULL_SHIFT		31
+#define SIFIVE_SERIAL_TXDATA_FULL_MASK		(1 << SIFIVE_SERIAL_TXDATA_FULL_SHIFT)
+#define SIFIVE_SERIAL_TXDATA_DATA_SHIFT		0
+#define SIFIVE_SERIAL_TXDATA_DATA_MASK		(0xff << SIFIVE_SERIAL_TXDATA_DATA_SHIFT)
+
+/* RXDATA */
+#define SIFIVE_SERIAL_RXDATA_OFFS		0x4
+#define SIFIVE_SERIAL_RXDATA_EMPTY_SHIFT	31
+#define SIFIVE_SERIAL_RXDATA_EMPTY_MASK		(1 << SIFIVE_SERIAL_RXDATA_EMPTY_SHIFT)
+#define SIFIVE_SERIAL_RXDATA_DATA_SHIFT		0
+#define SIFIVE_SERIAL_RXDATA_DATA_MASK		(0xff << SIFIVE_SERIAL_RXDATA_DATA_SHIFT)
+
+/* TXCTRL */
+#define SIFIVE_SERIAL_TXCTRL_OFFS		0x8
+#define SIFIVE_SERIAL_TXCTRL_TXCNT_SHIFT	16
+#define SIFIVE_SERIAL_TXCTRL_TXCNT_MASK		(0x7 << SIFIVE_SERIAL_TXCTRL_TXCNT_SHIFT)
+#define SIFIVE_SERIAL_TXCTRL_NSTOP_SHIFT	1
+#define SIFIVE_SERIAL_TXCTRL_NSTOP_MASK		(1 << SIFIVE_SERIAL_TXCTRL_NSTOP_SHIFT)
+#define SIFIVE_SERIAL_TXCTRL_TXEN_SHIFT		0
+#define SIFIVE_SERIAL_TXCTRL_TXEN_MASK		(1 << SIFIVE_SERIAL_TXCTRL_TXEN_SHIFT)
+
+/* RXCTRL */
+#define SIFIVE_SERIAL_RXCTRL_OFFS		0xC
+#define SIFIVE_SERIAL_RXCTRL_RXCNT_SHIFT	16
+#define SIFIVE_SERIAL_RXCTRL_RXCNT_MASK		(0x7 << SIFIVE_SERIAL_TXCTRL_TXCNT_SHIFT)
+#define SIFIVE_SERIAL_RXCTRL_RXEN_SHIFT		0
+#define SIFIVE_SERIAL_RXCTRL_RXEN_MASK		(1 << SIFIVE_SERIAL_RXCTRL_RXEN_SHIFT)
+
+/* IE */
+#define SIFIVE_SERIAL_IE_OFFS			0x10
+#define SIFIVE_SERIAL_IE_RXWM_SHIFT		1
+#define SIFIVE_SERIAL_IE_RXWM_MASK		(1 << SIFIVE_SERIAL_IE_RXWM_SHIFT)
+#define SIFIVE_SERIAL_IE_TXWM_SHIFT		0
+#define SIFIVE_SERIAL_IE_TXWM_MASK		(1 << SIFIVE_SERIAL_IE_TXWM_SHIFT)
+
+/* IP */
+#define SIFIVE_SERIAL_IP_OFFS			0x14
+#define SIFIVE_SERIAL_IP_RXWM_SHIFT		1
+#define SIFIVE_SERIAL_IP_RXWM_MASK		(1 << SIFIVE_SERIAL_IP_RXWM_SHIFT)
+#define SIFIVE_SERIAL_IP_TXWM_SHIFT		0
+#define SIFIVE_SERIAL_IP_TXWM_MASK		(1 << SIFIVE_SERIAL_IP_TXWM_SHIFT)
+
+/* DIV */
+#define SIFIVE_SERIAL_DIV_OFFS			0x18
+#define SIFIVE_SERIAL_DIV_DIV_SHIFT		0
+#define SIFIVE_SERIAL_DIV_DIV_MASK		(0xffff << SIFIVE_SERIAL_IP_DIV_SHIFT)
+
+/*
+ * Config macros
+ */
+
+/*
+ * SIFIVE_SERIAL_MAX_PORTS: maximum number of UARTs on a device that can
+ *                          host a serial console
+ */
+#define SIFIVE_SERIAL_MAX_PORTS			8
+
+/*
+ * SIFIVE_DEFAULT_BAUD_RATE: default baud rate that the driver should
+ *                           configure itself to use
+ */
+#define SIFIVE_DEFAULT_BAUD_RATE		115200
+
+/* SIFIVE_SERIAL_NAME: our driver's name that we pass to the operating system */
+#define SIFIVE_SERIAL_NAME			"sifive-serial"
+
+/* SIFIVE_TTY_PREFIX: tty name prefix for SiFive serial ports */
+#define SIFIVE_TTY_PREFIX			"ttySIF"
+
+/* SIFIVE_TX_FIFO_DEPTH: depth of the TX FIFO (in bytes) */
+#define SIFIVE_TX_FIFO_DEPTH			8
+
+/* SIFIVE_RX_FIFO_DEPTH: depth of the TX FIFO (in bytes) */
+#define SIFIVE_RX_FIFO_DEPTH			8
+
+#if (SIFIVE_TX_FIFO_DEPTH != SIFIVE_RX_FIFO_DEPTH)
+#error Driver does not support configurations with different TX, RX FIFO sizes
+#endif
+
+/*
+ *
+ */
+
+/**
+ * struct sifive_serial_port - driver-specific data extension to struct uart_port
+ * @port: struct uart_port embedded in this struct
+ * @dev: struct device *
+ * @ier: shadowed copy of the interrupt enable register
+ * @baud_rate: UART serial line rate (e.g., 115200 baud)
+ * @clk: reference to this device's clock
+ * @clk_notifier: clock rate change notifier for upstream clock changes
+ *
+ * Configuration data specific to this SiFive UART.
+ */
+struct sifive_serial_port {
+	struct uart_port	port;
+	struct device		*dev;
+	unsigned char		ier;
+	unsigned long		baud_rate;
+	struct clk		*clk;
+	struct notifier_block	clk_notifier;
+};
+
+/*
+ * Structure container-of macros
+ */
+
+#define port_to_sifive_serial_port(p) (container_of((p), \
+						    struct sifive_serial_port, \
+						    port))
+
+#define notifier_to_sifive_serial_port(nb) (container_of((nb), \
+							 struct sifive_serial_port, \
+							 clk_notifier))
+
+/*
+ * Forward declarations
+ */
+static void sifive_serial_stop_tx(struct uart_port *port);
+
+/*
+ * Internal functions
+ */
+
+/**
+ * __ssp_early_writel() - write to a SiFive serial port register (early)
+ * @port: pointer to a struct uart_port record
+ * @offs: register address offset from the IP block base address
+ * @v: value to write to the register
+ *
+ * Given a pointer @port to a struct uart_port record, write the value
+ * @v to the IP block register address offset @offs.  This function is
+ * intended for early console use.
+ *
+ * Context: Intended to be used only by the earlyconsole code.
+ */
+static void __ssp_early_writel(u32 v, u16 offs, struct uart_port *port)
+{
+	writel_relaxed(v, port->membase + offs);
+}
+
+/**
+ * __ssp_early_readl() - read from a SiFive serial port register (early)
+ * @port: pointer to a struct uart_port record
+ * @offs: register address offset from the IP block base address
+ *
+ * Given a pointer @port to a struct uart_port record, read the
+ * contents of the IP block register located at offset @offs from the
+ * IP block base and return it.  This function is intended for early
+ * console use.
+ *
+ * Context: Intended to be called only by the earlyconsole code or by
+ *          __ssp_readl() or __ssp_writel() (in this driver)
+ *
+ * Returns: the register value read from the UART.
+ */
+static u32 __ssp_early_readl(struct uart_port *port, u16 offs)
+{
+	return readl_relaxed(port->membase + offs);
+}
+
+/**
+ * __ssp_writel() - write to a SiFive serial port register
+ * @v: value to write to the register
+ * @offs: register address offset from the IP block base address
+ * @ssp: pointer to a struct sifive_serial_port record
+ *
+ * Write the value @v to the IP block register located at offset @offs from the
+ * IP block base, given a pointer @ssp to a struct sifive_serial_port record.
+ *
+ * Context: Any context.
+ */
+static void __ssp_writel(u32 v, u16 offs, struct sifive_serial_port *ssp)
+{
+	__ssp_early_writel(v, offs, &ssp->port);
+}
+
+/**
+ * __ssp_readl() - read from a SiFive serial port register
+ * @ssp: pointer to a struct sifive_serial_port record
+ * @offs: register address offset from the IP block base address
+ *
+ * Read the contents of the IP block register located at offset @offs from the
+ * IP block base, given a pointer @ssp to a struct sifive_serial_port record.
+ *
+ * Context: Any context.
+ *
+ * Returns: the value of the UART register
+ */
+static u32 __ssp_readl(struct sifive_serial_port *ssp, u16 offs)
+{
+	return __ssp_early_readl(&ssp->port, offs);
+}
+
+/**
+ * sifive_serial_is_txfifo_full() - is the TXFIFO full?
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Read the transmit FIFO "full" bit, returning a non-zero value if the
+ * TX FIFO is full, or zero if space remains.  Intended to be used to prevent
+ * writes to the TX FIFO when it's full.
+ *
+ * Returns: SIFIVE_SERIAL_TXDATA_FULL_MASK (non-zero) if the transmit FIFO
+ * is full, or 0 if space remains.
+ */
+static int sifive_serial_is_txfifo_full(struct sifive_serial_port *ssp)
+{
+	return __ssp_readl(ssp, SIFIVE_SERIAL_TXDATA_OFFS) &
+		SIFIVE_SERIAL_TXDATA_FULL_MASK;
+}
+
+/**
+ * __ssp_transmit_char() - enqueue a byte to transmit onto the TX FIFO
+ * @ssp: pointer to a struct sifive_serial_port
+ * @ch: character to transmit
+ *
+ * Enqueue a byte @ch onto the transmit FIFO, given a pointer @ssp to the
+ * struct sifive_serial_port * to transmit on.  Caller should first check to
+ * ensure that the TXFIFO has space; see sifive_serial_is_txfifo_full().
+ *
+ * Context: Any context.
+ */
+static void __ssp_transmit_char(struct sifive_serial_port *ssp, int ch)
+{
+	__ssp_writel(ch, SIFIVE_SERIAL_TXDATA_OFFS, ssp);
+}
+
+/**
+ * __ssp_transmit_chars() - enqueue multiple bytes onto the TX FIFO
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Transfer up to a TX FIFO size's worth of characters from the Linux serial
+ * transmit buffer to the SiFive UART TX FIFO.
+ *
+ * Context: Any context.  Expects @ssp->port.lock to be held by caller.
+ */
+static void __ssp_transmit_chars(struct sifive_serial_port *ssp)
+{
+	u8 ch;
+
+	uart_port_tx_limited(&ssp->port, ch, SIFIVE_TX_FIFO_DEPTH,
+		true,
+		__ssp_transmit_char(ssp, ch),
+		({}));
+}
+
+/**
+ * __ssp_enable_txwm() - enable transmit watermark interrupts
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Enable interrupt generation when the transmit FIFO watermark is reached
+ * on the SiFive UART referred to by @ssp.
+ */
+static void __ssp_enable_txwm(struct sifive_serial_port *ssp)
+{
+	if (ssp->ier & SIFIVE_SERIAL_IE_TXWM_MASK)
+		return;
+
+	ssp->ier |= SIFIVE_SERIAL_IE_TXWM_MASK;
+	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);
+}
+
+/**
+ * __ssp_enable_rxwm() - enable receive watermark interrupts
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Enable interrupt generation when the receive FIFO watermark is reached
+ * on the SiFive UART referred to by @ssp.
+ */
+static void __ssp_enable_rxwm(struct sifive_serial_port *ssp)
+{
+	if (ssp->ier & SIFIVE_SERIAL_IE_RXWM_MASK)
+		return;
+
+	ssp->ier |= SIFIVE_SERIAL_IE_RXWM_MASK;
+	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);
+}
+
+/**
+ * __ssp_disable_txwm() - disable transmit watermark interrupts
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Disable interrupt generation when the transmit FIFO watermark is reached
+ * on the UART referred to by @ssp.
+ */
+static void __ssp_disable_txwm(struct sifive_serial_port *ssp)
+{
+	if (!(ssp->ier & SIFIVE_SERIAL_IE_TXWM_MASK))
+		return;
+
+	ssp->ier &= ~SIFIVE_SERIAL_IE_TXWM_MASK;
+	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);
+}
+
+/**
+ * __ssp_disable_rxwm() - disable receive watermark interrupts
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Disable interrupt generation when the receive FIFO watermark is reached
+ * on the UART referred to by @ssp.
+ */
+static void __ssp_disable_rxwm(struct sifive_serial_port *ssp)
+{
+	if (!(ssp->ier & SIFIVE_SERIAL_IE_RXWM_MASK))
+		return;
+
+	ssp->ier &= ~SIFIVE_SERIAL_IE_RXWM_MASK;
+	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);
+}
+
+/**
+ * __ssp_receive_char() - receive a byte from the UART
+ * @ssp: pointer to a struct sifive_serial_port
+ * @is_empty: char pointer to return whether the RX FIFO is empty
+ *
+ * Try to read a byte from the SiFive UART RX FIFO, referenced by
+ * @ssp, and to return it.  Also returns the RX FIFO empty bit in
+ * the char pointed to by @ch.  The caller must pass the byte back to the
+ * Linux serial layer if needed.
+ *
+ * Returns: the byte read from the UART RX FIFO.
+ */
+static char __ssp_receive_char(struct sifive_serial_port *ssp, char *is_empty)
+{
+	u32 v;
+	u8 ch;
+
+	v = __ssp_readl(ssp, SIFIVE_SERIAL_RXDATA_OFFS);
+
+	if (!is_empty)
+		WARN_ON(1);
+	else
+		*is_empty = (v & SIFIVE_SERIAL_RXDATA_EMPTY_MASK) >>
+			SIFIVE_SERIAL_RXDATA_EMPTY_SHIFT;
+
+	ch = (v & SIFIVE_SERIAL_RXDATA_DATA_MASK) >>
+		SIFIVE_SERIAL_RXDATA_DATA_SHIFT;
+
+	return ch;
+}
+
+/**
+ * __ssp_receive_chars() - receive multiple bytes from the UART
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Receive up to an RX FIFO's worth of bytes from the SiFive UART referred
+ * to by @ssp and pass them up to the Linux serial layer.
+ *
+ * Context: Expects ssp->port.lock to be held by caller.
+ */
+static void __ssp_receive_chars(struct sifive_serial_port *ssp)
+{
+	char is_empty;
+	int c;
+	u8 ch;
+
+	for (c = SIFIVE_RX_FIFO_DEPTH; c > 0; --c) {
+		ch = __ssp_receive_char(ssp, &is_empty);
+		if (is_empty)
+			break;
+
+		ssp->port.icount.rx++;
+		uart_insert_char(&ssp->port, 0, 0, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(&ssp->port.state->port);
+}
+
+/**
+ * __ssp_update_div() - calculate the divisor setting by the line rate
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Calculate the appropriate value of the clock divisor for the UART
+ * and target line rate referred to by @ssp and write it into the
+ * hardware.
+ */
+static void __ssp_update_div(struct sifive_serial_port *ssp)
+{
+	u16 div;
+
+	div = DIV_ROUND_UP(ssp->port.uartclk, ssp->baud_rate) - 1;
+
+	__ssp_writel(div, SIFIVE_SERIAL_DIV_OFFS, ssp);
+}
+
+/**
+ * __ssp_update_baud_rate() - set the UART "baud rate"
+ * @ssp: pointer to a struct sifive_serial_port
+ * @rate: new target bit rate
+ *
+ * Calculate the UART divisor value for the target bit rate @rate for the
+ * SiFive UART described by @ssp and program it into the UART.  There may
+ * be some error between the target bit rate and the actual bit rate implemented
+ * by the UART due to clock ratio granularity.
+ */
+static void __ssp_update_baud_rate(struct sifive_serial_port *ssp,
+				   unsigned int rate)
+{
+	if (ssp->baud_rate == rate)
+		return;
+
+	ssp->baud_rate = rate;
+	__ssp_update_div(ssp);
+}
+
+/**
+ * __ssp_set_stop_bits() - set the number of stop bits
+ * @ssp: pointer to a struct sifive_serial_port
+ * @nstop: 1 or 2 (stop bits)
+ *
+ * Program the SiFive UART referred to by @ssp to use @nstop stop bits.
+ */
+static void __ssp_set_stop_bits(struct sifive_serial_port *ssp, char nstop)
+{
+	u32 v;
+
+	if (nstop < 1 || nstop > 2) {
+		WARN_ON(1);
+		return;
+	}
+
+	v = __ssp_readl(ssp, SIFIVE_SERIAL_TXCTRL_OFFS);
+	v &= ~SIFIVE_SERIAL_TXCTRL_NSTOP_MASK;
+	v |= (nstop - 1) << SIFIVE_SERIAL_TXCTRL_NSTOP_SHIFT;
+	__ssp_writel(v, SIFIVE_SERIAL_TXCTRL_OFFS, ssp);
+}
+
+/**
+ * __ssp_wait_for_xmitr() - wait for an empty slot on the TX FIFO
+ * @ssp: pointer to a struct sifive_serial_port
+ *
+ * Delay while the UART TX FIFO referred to by @ssp is marked as full.
+ *
+ * Context: Any context.
+ */
+static void __maybe_unused __ssp_wait_for_xmitr(struct sifive_serial_port *ssp)
+{
+	while (sifive_serial_is_txfifo_full(ssp))
+		udelay(1); /* XXX Could probably be more intelligent here */
+}
+
+/*
+ * Linux serial API functions
+ */
+
+static void sifive_serial_stop_tx(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_disable_txwm(ssp);
+}
+
+static void sifive_serial_stop_rx(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_disable_rxwm(ssp);
+}
+
+static void sifive_serial_start_tx(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_enable_txwm(ssp);
+}
+
+static irqreturn_t sifive_serial_irq(int irq, void *dev_id)
+{
+	struct sifive_serial_port *ssp = dev_id;
+	u32 ip;
+
+	spin_lock(&ssp->port.lock);
+
+	ip = __ssp_readl(ssp, SIFIVE_SERIAL_IP_OFFS);
+	if (!ip) {
+		spin_unlock(&ssp->port.lock);
+		return IRQ_NONE;
+	}
+
+	if (ip & SIFIVE_SERIAL_IP_RXWM_MASK)
+		__ssp_receive_chars(ssp);
+	if (ip & SIFIVE_SERIAL_IP_TXWM_MASK)
+		__ssp_transmit_chars(ssp);
+
+	spin_unlock(&ssp->port.lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int sifive_serial_tx_empty(struct uart_port *port)
+{
+	return TIOCSER_TEMT;
+}
+
+static unsigned int sifive_serial_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
+}
+
+static void sifive_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* IP block does not support these signals */
+}
+
+static void sifive_serial_break_ctl(struct uart_port *port, int break_state)
+{
+	/* IP block does not support sending a break */
+}
+
+static int sifive_serial_startup(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_enable_rxwm(ssp);
+
+	return 0;
+}
+
+static void sifive_serial_shutdown(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_disable_rxwm(ssp);
+	__ssp_disable_txwm(ssp);
+}
+
+/**
+ * sifive_serial_clk_notifier() - clock post-rate-change notifier
+ * @nb: pointer to the struct notifier_block, from the notifier code
+ * @event: event mask from the notifier code
+ * @data: pointer to the struct clk_notifier_data from the notifier code
+ *
+ * On the V0 SoC, the UART IP block is derived from the CPU clock source
+ * after a synchronous divide-by-two divider, so any CPU clock rate change
+ * requires the UART baud rate to be updated.  This presumably corrupts any
+ * serial word currently being transmitted or received.  In order to avoid
+ * corrupting the output data stream, we drain the transmit queue before
+ * allowing the clock's rate to be changed.
+ */
+static int sifive_serial_clk_notifier(struct notifier_block *nb,
+				      unsigned long event, void *data)
+{
+	struct clk_notifier_data *cnd = data;
+	struct sifive_serial_port *ssp = notifier_to_sifive_serial_port(nb);
+
+	if (event == PRE_RATE_CHANGE) {
+		/*
+		 * The TX watermark is always set to 1 by this driver, which
+		 * means that the TX busy bit will lower when there are 0 bytes
+		 * left in the TX queue -- in other words, when the TX FIFO is
+		 * empty.
+		 */
+		__ssp_wait_for_xmitr(ssp);
+		/*
+		 * On the cycle the TX FIFO goes empty there is still a full
+		 * UART frame left to be transmitted in the shift register.
+		 * The UART provides no way for software to directly determine
+		 * when that last frame has been transmitted, so we just sleep
+		 * here instead.  As we're not tracking the number of stop bits
+		 * they're just worst cased here.  The rest of the serial
+		 * framing parameters aren't configurable by software.
+		 */
+		udelay(DIV_ROUND_UP(12 * 1000 * 1000, ssp->baud_rate));
+	}
+
+	if (event == POST_RATE_CHANGE && ssp->port.uartclk != cnd->new_rate) {
+		ssp->port.uartclk = cnd->new_rate;
+		__ssp_update_div(ssp);
+	}
+
+	return NOTIFY_OK;
+}
+
+static void sifive_serial_set_termios(struct uart_port *port,
+				      struct ktermios *termios,
+				      const struct ktermios *old)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+	unsigned long flags;
+	u32 v, old_v;
+	int rate;
+	char nstop;
+
+	if ((termios->c_cflag & CSIZE) != CS8) {
+		dev_err_once(ssp->port.dev, "only 8-bit words supported\n");
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+	}
+	if (termios->c_iflag & (INPCK | PARMRK))
+		dev_err_once(ssp->port.dev, "parity checking not supported\n");
+	if (termios->c_iflag & BRKINT)
+		dev_err_once(ssp->port.dev, "BREAK detection not supported\n");
+	termios->c_iflag &= ~(INPCK|PARMRK|BRKINT);
+
+	/* Set number of stop bits */
+	nstop = (termios->c_cflag & CSTOPB) ? 2 : 1;
+	__ssp_set_stop_bits(ssp, nstop);
+
+	/* Set line rate */
+	rate = uart_get_baud_rate(port, termios, old, 0,
+				  ssp->port.uartclk / 16);
+	__ssp_update_baud_rate(ssp, rate);
+
+	spin_lock_irqsave(&ssp->port.lock, flags);
+
+	/* Update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, rate);
+
+	ssp->port.read_status_mask = 0;
+
+	/* Ignore all characters if CREAD is not set */
+	v = __ssp_readl(ssp, SIFIVE_SERIAL_RXCTRL_OFFS);
+	old_v = v;
+	if ((termios->c_cflag & CREAD) == 0)
+		v &= SIFIVE_SERIAL_RXCTRL_RXEN_MASK;
+	else
+		v |= SIFIVE_SERIAL_RXCTRL_RXEN_MASK;
+	if (v != old_v)
+		__ssp_writel(v, SIFIVE_SERIAL_RXCTRL_OFFS, ssp);
+
+	spin_unlock_irqrestore(&ssp->port.lock, flags);
+}
+
+static void sifive_serial_release_port(struct uart_port *port)
+{
+}
+
+static int sifive_serial_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sifive_serial_config_port(struct uart_port *port, int flags)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	ssp->port.type = PORT_SIFIVE_V0;
+}
+
+static int sifive_serial_verify_port(struct uart_port *port,
+				     struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const char *sifive_serial_type(struct uart_port *port)
+{
+	return port->type == PORT_SIFIVE_V0 ? "SiFive UART v0" : NULL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int sifive_serial_poll_get_char(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+	char is_empty, ch;
+
+	ch = __ssp_receive_char(ssp, &is_empty);
+	if (is_empty)
+		return NO_POLL_CHAR;
+
+	return ch;
+}
+
+static void sifive_serial_poll_put_char(struct uart_port *port,
+					unsigned char c)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_wait_for_xmitr(ssp);
+	__ssp_transmit_char(ssp, c);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+/*
+ * Early console support
+ */
+
+#ifdef CONFIG_SERIAL_EARLYCON
+static void early_sifive_serial_putc(struct uart_port *port, unsigned char c)
+{
+	while (__ssp_early_readl(port, SIFIVE_SERIAL_TXDATA_OFFS) &
+	       SIFIVE_SERIAL_TXDATA_FULL_MASK)
+		cpu_relax();
+
+	__ssp_early_writel(c, SIFIVE_SERIAL_TXDATA_OFFS, port);
+}
+
+static void early_sifive_serial_write(struct console *con, const char *s,
+				      unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+	struct uart_port *port = &dev->port;
+
+	uart_console_write(port, s, n, early_sifive_serial_putc);
+}
+
+static int __init early_sifive_serial_setup(struct earlycon_device *dev,
+					    const char *options)
+{
+	struct uart_port *port = &dev->port;
+
+	if (!port->membase)
+		return -ENODEV;
+
+	dev->con->write = early_sifive_serial_write;
+
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(sifive, "sifive,uart0", early_sifive_serial_setup);
+OF_EARLYCON_DECLARE(sifive, "sifive,fu540-c000-uart0",
+		    early_sifive_serial_setup);
+#endif /* CONFIG_SERIAL_EARLYCON */
+
+/*
+ * Linux console interface
+ */
+
+#ifdef CONFIG_SERIAL_SIFIVE_CONSOLE
+
+static struct sifive_serial_port *sifive_serial_console_ports[SIFIVE_SERIAL_MAX_PORTS];
+
+static void sifive_serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_wait_for_xmitr(ssp);
+	__ssp_transmit_char(ssp, ch);
+}
+
+static void sifive_serial_console_write(struct console *co, const char *s,
+					unsigned int count)
+{
+	struct sifive_serial_port *ssp = sifive_serial_console_ports[co->index];
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	if (!ssp)
+		return;
+
+	local_irq_save(flags);
+	if (ssp->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&ssp->port.lock);
+	else
+		spin_lock(&ssp->port.lock);
+
+	ier = __ssp_readl(ssp, SIFIVE_SERIAL_IE_OFFS);
+	__ssp_writel(0, SIFIVE_SERIAL_IE_OFFS, ssp);
+
+	uart_console_write(&ssp->port, s, count, sifive_serial_console_putchar);
+
+	__ssp_writel(ier, SIFIVE_SERIAL_IE_OFFS, ssp);
+
+	if (locked)
+		spin_unlock(&ssp->port.lock);
+	local_irq_restore(flags);
+}
+
+static int sifive_serial_console_setup(struct console *co, char *options)
+{
+	struct sifive_serial_port *ssp;
+	int baud = SIFIVE_DEFAULT_BAUD_RATE;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= SIFIVE_SERIAL_MAX_PORTS)
+		return -ENODEV;
+
+	ssp = sifive_serial_console_ports[co->index];
+	if (!ssp)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&ssp->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sifive_serial_uart_driver;
+
+static struct console sifive_serial_console = {
+	.name		= SIFIVE_TTY_PREFIX,
+	.write		= sifive_serial_console_write,
+	.device		= uart_console_device,
+	.setup		= sifive_serial_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &sifive_serial_uart_driver,
+};
+
+static int __init sifive_console_init(void)
+{
+	register_console(&sifive_serial_console);
+	return 0;
+}
+
+console_initcall(sifive_console_init);
+
+static void __ssp_add_console_port(struct sifive_serial_port *ssp)
+{
+	sifive_serial_console_ports[ssp->port.line] = ssp;
+}
+
+static void __ssp_remove_console_port(struct sifive_serial_port *ssp)
+{
+	sifive_serial_console_ports[ssp->port.line] = NULL;
+}
+
+#define SIFIVE_SERIAL_CONSOLE	(&sifive_serial_console)
+
+#else
+
+#define SIFIVE_SERIAL_CONSOLE	NULL
+
+static void __ssp_add_console_port(struct sifive_serial_port *ssp)
+{}
+static void __ssp_remove_console_port(struct sifive_serial_port *ssp)
+{}
+
+#endif
+
+static const struct uart_ops sifive_serial_uops = {
+	.tx_empty	= sifive_serial_tx_empty,
+	.set_mctrl	= sifive_serial_set_mctrl,
+	.get_mctrl	= sifive_serial_get_mctrl,
+	.stop_tx	= sifive_serial_stop_tx,
+	.start_tx	= sifive_serial_start_tx,
+	.stop_rx	= sifive_serial_stop_rx,
+	.break_ctl	= sifive_serial_break_ctl,
+	.startup	= sifive_serial_startup,
+	.shutdown	= sifive_serial_shutdown,
+	.set_termios	= sifive_serial_set_termios,
+	.type		= sifive_serial_type,
+	.release_port	= sifive_serial_release_port,
+	.request_port	= sifive_serial_request_port,
+	.config_port	= sifive_serial_config_port,
+	.verify_port	= sifive_serial_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= sifive_serial_poll_get_char,
+	.poll_put_char	= sifive_serial_poll_put_char,
+#endif
+};
+
+static struct uart_driver sifive_serial_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= SIFIVE_SERIAL_NAME,
+	.dev_name	= SIFIVE_TTY_PREFIX,
+	.nr		= SIFIVE_SERIAL_MAX_PORTS,
+	.cons		= SIFIVE_SERIAL_CONSOLE,
+};
+
+static int sifive_serial_probe(struct platform_device *pdev)
+{
+	struct sifive_serial_port *ssp;
+	struct resource *mem;
+	struct clk *clk;
+	void __iomem *base;
+	int irq, id, r;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -EPROBE_DEFER;
+
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "unable to find controller clock\n");
+		return PTR_ERR(clk);
+	}
+
+	id = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (id < 0) {
+		dev_err(&pdev->dev, "missing aliases entry\n");
+		return id;
+	}
+
+#ifdef CONFIG_SERIAL_SIFIVE_CONSOLE
+	if (id > SIFIVE_SERIAL_MAX_PORTS) {
+		dev_err(&pdev->dev, "too many UARTs (%d)\n", id);
+		return -EINVAL;
+	}
+#endif
+
+	ssp = devm_kzalloc(&pdev->dev, sizeof(*ssp), GFP_KERNEL);
+	if (!ssp)
+		return -ENOMEM;
+
+	ssp->port.dev = &pdev->dev;
+	ssp->port.type = PORT_SIFIVE_V0;
+	ssp->port.iotype = UPIO_MEM;
+	ssp->port.irq = irq;
+	ssp->port.fifosize = SIFIVE_TX_FIFO_DEPTH;
+	ssp->port.ops = &sifive_serial_uops;
+	ssp->port.line = id;
+	ssp->port.mapbase = mem->start;
+	ssp->port.membase = base;
+	ssp->dev = &pdev->dev;
+	ssp->clk = clk;
+	ssp->clk_notifier.notifier_call = sifive_serial_clk_notifier;
+
+	r = clk_notifier_register(ssp->clk, &ssp->clk_notifier);
+	if (r) {
+		dev_err(&pdev->dev, "could not register clock notifier: %d\n",
+			r);
+		goto probe_out1;
+	}
+
+	/* Set up clock divider */
+	ssp->port.uartclk = clk_get_rate(ssp->clk);
+	ssp->baud_rate = SIFIVE_DEFAULT_BAUD_RATE;
+	__ssp_update_div(ssp);
+
+	platform_set_drvdata(pdev, ssp);
+
+	/* Enable transmits and set the watermark level to 1 */
+	__ssp_writel((1 << SIFIVE_SERIAL_TXCTRL_TXCNT_SHIFT) |
+		     SIFIVE_SERIAL_TXCTRL_TXEN_MASK,
+		     SIFIVE_SERIAL_TXCTRL_OFFS, ssp);
+
+	/* Enable receives and set the watermark level to 0 */
+	__ssp_writel((0 << SIFIVE_SERIAL_RXCTRL_RXCNT_SHIFT) |
+		     SIFIVE_SERIAL_RXCTRL_RXEN_MASK,
+		     SIFIVE_SERIAL_RXCTRL_OFFS, ssp);
+
+	r = request_irq(ssp->port.irq, sifive_serial_irq, ssp->port.irqflags,
+			dev_name(&pdev->dev), ssp);
+	if (r) {
+		dev_err(&pdev->dev, "could not attach interrupt: %d\n", r);
+		goto probe_out2;
+	}
+
+	__ssp_add_console_port(ssp);
+
+	r = uart_add_one_port(&sifive_serial_uart_driver, &ssp->port);
+	if (r != 0) {
+		dev_err(&pdev->dev, "could not add uart: %d\n", r);
+		goto probe_out3;
+	}
+
+	return 0;
+
+probe_out3:
+	__ssp_remove_console_port(ssp);
+	free_irq(ssp->port.irq, ssp);
+probe_out2:
+	clk_notifier_unregister(ssp->clk, &ssp->clk_notifier);
+probe_out1:
+	return r;
+}
+
+static int sifive_serial_remove(struct platform_device *dev)
+{
+	struct sifive_serial_port *ssp = platform_get_drvdata(dev);
+
+	__ssp_remove_console_port(ssp);
+	uart_remove_one_port(&sifive_serial_uart_driver, &ssp->port);
+	free_irq(ssp->port.irq, ssp);
+	clk_notifier_unregister(ssp->clk, &ssp->clk_notifier);
+
+	return 0;
+}
+
+static int sifive_serial_suspend(struct device *dev)
+{
+	struct sifive_serial_port *ssp = dev_get_drvdata(dev);
+
+	return uart_suspend_port(&sifive_serial_uart_driver, &ssp->port);
+}
+
+static int sifive_serial_resume(struct device *dev)
+{
+	struct sifive_serial_port *ssp = dev_get_drvdata(dev);
+
+	return uart_resume_port(&sifive_serial_uart_driver, &ssp->port);
+}
+
+DEFINE_SIMPLE_DEV_PM_OPS(sifive_uart_pm_ops, sifive_serial_suspend,
+			 sifive_serial_resume);
+
+static const struct of_device_id sifive_serial_of_match[] = {
+	{ .compatible = "sifive,fu540-c000-uart0" },
+	{ .compatible = "sifive,uart0" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sifive_serial_of_match);
+
+static struct platform_driver sifive_serial_platform_driver = {
+	.probe		= sifive_serial_probe,
+	.remove		= sifive_serial_remove,
+	.driver		= {
+		.name	= SIFIVE_SERIAL_NAME,
+		.pm = pm_sleep_ptr(&sifive_uart_pm_ops),
+		.of_match_table = sifive_serial_of_match,
+	},
+};
+
+static int __init sifive_serial_init(void)
+{
+	int r;
+
+	r = uart_register_driver(&sifive_serial_uart_driver);
+	if (r)
+		goto init_out1;
+
+	r = platform_driver_register(&sifive_serial_platform_driver);
+	if (r)
+		goto init_out2;
+
+	return 0;
+
+init_out2:
+	uart_unregister_driver(&sifive_serial_uart_driver);
+init_out1:
+	return r;
+}
+
+static void __exit sifive_serial_exit(void)
+{
+	platform_driver_unregister(&sifive_serial_platform_driver);
+	uart_unregister_driver(&sifive_serial_uart_driver);
+}
+
+module_init(sifive_serial_init);
+module_exit(sifive_serial_exit);
+
+MODULE_DESCRIPTION("SiFive UART serial driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul Walmsley <paul@pwsan.com>");
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
new file mode 100644
index 000000000..f328fa572
--- /dev/null
+++ b/drivers/tty/serial/sprd_serial.c
@@ -0,0 +1,1271 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012-2015 Spreadtrum Communications Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma/sprd-dma.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/* device name */
+#define UART_NR_MAX		8
+#define SPRD_TTY_NAME		"ttyS"
+#define SPRD_FIFO_SIZE		128
+#define SPRD_DEF_RATE		26000000
+#define SPRD_BAUD_IO_LIMIT	3000000
+#define SPRD_TIMEOUT		256000
+
+/* the offset of serial registers and BITs for them */
+/* data registers */
+#define SPRD_TXD		0x0000
+#define SPRD_RXD		0x0004
+
+/* line status register and its BITs  */
+#define SPRD_LSR		0x0008
+#define SPRD_LSR_OE		BIT(4)
+#define SPRD_LSR_FE		BIT(3)
+#define SPRD_LSR_PE		BIT(2)
+#define SPRD_LSR_BI		BIT(7)
+#define SPRD_LSR_TX_OVER	BIT(15)
+
+/* data number in TX and RX fifo */
+#define SPRD_STS1		0x000C
+#define SPRD_RX_FIFO_CNT_MASK	GENMASK(7, 0)
+#define SPRD_TX_FIFO_CNT_MASK	GENMASK(15, 8)
+
+/* interrupt enable register and its BITs */
+#define SPRD_IEN		0x0010
+#define SPRD_IEN_RX_FULL	BIT(0)
+#define SPRD_IEN_TX_EMPTY	BIT(1)
+#define SPRD_IEN_BREAK_DETECT	BIT(7)
+#define SPRD_IEN_TIMEOUT	BIT(13)
+
+/* interrupt clear register */
+#define SPRD_ICLR		0x0014
+#define SPRD_ICLR_TIMEOUT	BIT(13)
+
+/* line control register */
+#define SPRD_LCR		0x0018
+#define SPRD_LCR_STOP_1BIT	0x10
+#define SPRD_LCR_STOP_2BIT	0x30
+#define SPRD_LCR_DATA_LEN	(BIT(2) | BIT(3))
+#define SPRD_LCR_DATA_LEN5	0x0
+#define SPRD_LCR_DATA_LEN6	0x4
+#define SPRD_LCR_DATA_LEN7	0x8
+#define SPRD_LCR_DATA_LEN8	0xc
+#define SPRD_LCR_PARITY		(BIT(0) | BIT(1))
+#define SPRD_LCR_PARITY_EN	0x2
+#define SPRD_LCR_EVEN_PAR	0x0
+#define SPRD_LCR_ODD_PAR	0x1
+
+/* control register 1 */
+#define SPRD_CTL1		0x001C
+#define SPRD_DMA_EN		BIT(15)
+#define SPRD_LOOPBACK_EN	BIT(14)
+#define RX_HW_FLOW_CTL_THLD	BIT(6)
+#define RX_HW_FLOW_CTL_EN	BIT(7)
+#define TX_HW_FLOW_CTL_EN	BIT(8)
+#define RX_TOUT_THLD_DEF	0x3E00
+#define RX_HFC_THLD_DEF		0x40
+
+/* fifo threshold register */
+#define SPRD_CTL2		0x0020
+#define THLD_TX_EMPTY		0x40
+#define THLD_TX_EMPTY_SHIFT	8
+#define THLD_RX_FULL		0x40
+#define THLD_RX_FULL_MASK	GENMASK(6, 0)
+
+/* config baud rate register */
+#define SPRD_CLKD0		0x0024
+#define SPRD_CLKD0_MASK		GENMASK(15, 0)
+#define SPRD_CLKD1		0x0028
+#define SPRD_CLKD1_MASK		GENMASK(20, 16)
+#define SPRD_CLKD1_SHIFT	16
+
+/* interrupt mask status register */
+#define SPRD_IMSR		0x002C
+#define SPRD_IMSR_RX_FIFO_FULL	BIT(0)
+#define SPRD_IMSR_TX_FIFO_EMPTY	BIT(1)
+#define SPRD_IMSR_BREAK_DETECT	BIT(7)
+#define SPRD_IMSR_TIMEOUT	BIT(13)
+#define SPRD_DEFAULT_SOURCE_CLK	26000000
+
+#define SPRD_RX_DMA_STEP	1
+#define SPRD_RX_FIFO_FULL	1
+#define SPRD_TX_FIFO_FULL	0x20
+#define SPRD_UART_RX_SIZE	(UART_XMIT_SIZE / 4)
+
+struct sprd_uart_dma {
+	struct dma_chan *chn;
+	unsigned char *virt;
+	dma_addr_t phys_addr;
+	dma_cookie_t cookie;
+	u32 trans_len;
+	bool enable;
+};
+
+struct sprd_uart_port {
+	struct uart_port port;
+	char name[16];
+	struct clk *clk;
+	struct sprd_uart_dma tx_dma;
+	struct sprd_uart_dma rx_dma;
+	dma_addr_t pos;
+	unsigned char *rx_buf_tail;
+};
+
+static struct sprd_uart_port *sprd_port[UART_NR_MAX];
+static int sprd_ports_num;
+
+static int sprd_start_dma_rx(struct uart_port *port);
+static int sprd_tx_dma_config(struct uart_port *port);
+
+static inline unsigned int serial_in(struct uart_port *port,
+				     unsigned int offset)
+{
+	return readl_relaxed(port->membase + offset);
+}
+
+static inline void serial_out(struct uart_port *port, unsigned int offset,
+			      int value)
+{
+	writel_relaxed(value, port->membase + offset);
+}
+
+static unsigned int sprd_tx_empty(struct uart_port *port)
+{
+	if (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
+		return 0;
+	else
+		return TIOCSER_TEMT;
+}
+
+static unsigned int sprd_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_DSR | TIOCM_CTS;
+}
+
+static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 val = serial_in(port, SPRD_CTL1);
+
+	if (mctrl & TIOCM_LOOP)
+		val |= SPRD_LOOPBACK_EN;
+	else
+		val &= ~SPRD_LOOPBACK_EN;
+
+	serial_out(port, SPRD_CTL1, val);
+}
+
+static void sprd_stop_rx(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	unsigned int ien, iclr;
+
+	if (sp->rx_dma.enable)
+		dmaengine_terminate_all(sp->rx_dma.chn);
+
+	iclr = serial_in(port, SPRD_ICLR);
+	ien = serial_in(port, SPRD_IEN);
+
+	ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
+	iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
+
+	serial_out(port, SPRD_IEN, ien);
+	serial_out(port, SPRD_ICLR, iclr);
+}
+
+static void sprd_uart_dma_enable(struct uart_port *port, bool enable)
+{
+	u32 val = serial_in(port, SPRD_CTL1);
+
+	if (enable)
+		val |= SPRD_DMA_EN;
+	else
+		val &= ~SPRD_DMA_EN;
+
+	serial_out(port, SPRD_CTL1, val);
+}
+
+static void sprd_stop_tx_dma(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct dma_tx_state state;
+	u32 trans_len;
+
+	dmaengine_pause(sp->tx_dma.chn);
+
+	dmaengine_tx_status(sp->tx_dma.chn, sp->tx_dma.cookie, &state);
+	if (state.residue) {
+		trans_len = state.residue - sp->tx_dma.phys_addr;
+		uart_xmit_advance(port, trans_len);
+		dma_unmap_single(port->dev, sp->tx_dma.phys_addr,
+				 sp->tx_dma.trans_len, DMA_TO_DEVICE);
+	}
+
+	dmaengine_terminate_all(sp->tx_dma.chn);
+	sp->tx_dma.trans_len = 0;
+}
+
+static int sprd_tx_buf_remap(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	sp->tx_dma.trans_len =
+		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	sp->tx_dma.phys_addr = dma_map_single(port->dev,
+					      (void *)&(xmit->buf[xmit->tail]),
+					      sp->tx_dma.trans_len,
+					      DMA_TO_DEVICE);
+	return dma_mapping_error(port->dev, sp->tx_dma.phys_addr);
+}
+
+static void sprd_complete_tx_dma(void *data)
+{
+	struct uart_port *port = (struct uart_port *)data;
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	dma_unmap_single(port->dev, sp->tx_dma.phys_addr,
+			 sp->tx_dma.trans_len, DMA_TO_DEVICE);
+
+	uart_xmit_advance(port, sp->tx_dma.trans_len);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit) || sprd_tx_buf_remap(port) ||
+	    sprd_tx_dma_config(port))
+		sp->tx_dma.trans_len = 0;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int sprd_uart_dma_submit(struct uart_port *port,
+				struct sprd_uart_dma *ud, u32 trans_len,
+				enum dma_transfer_direction direction,
+				dma_async_tx_callback callback)
+{
+	struct dma_async_tx_descriptor *dma_des;
+	unsigned long flags;
+
+	flags = SPRD_DMA_FLAGS(SPRD_DMA_CHN_MODE_NONE,
+			       SPRD_DMA_NO_TRG,
+			       SPRD_DMA_FRAG_REQ,
+			       SPRD_DMA_TRANS_INT);
+
+	dma_des = dmaengine_prep_slave_single(ud->chn, ud->phys_addr, trans_len,
+					      direction, flags);
+	if (!dma_des)
+		return -ENODEV;
+
+	dma_des->callback = callback;
+	dma_des->callback_param = port;
+
+	ud->cookie = dmaengine_submit(dma_des);
+	if (dma_submit_error(ud->cookie))
+		return dma_submit_error(ud->cookie);
+
+	dma_async_issue_pending(ud->chn);
+
+	return 0;
+}
+
+static int sprd_tx_dma_config(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	u32 burst = sp->tx_dma.trans_len > SPRD_TX_FIFO_FULL ?
+		SPRD_TX_FIFO_FULL : sp->tx_dma.trans_len;
+	int ret;
+	struct dma_slave_config cfg = {
+		.dst_addr = port->mapbase + SPRD_TXD,
+		.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+		.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+		.src_maxburst = burst,
+	};
+
+	ret = dmaengine_slave_config(sp->tx_dma.chn, &cfg);
+	if (ret < 0)
+		return ret;
+
+	return sprd_uart_dma_submit(port, &sp->tx_dma, sp->tx_dma.trans_len,
+				    DMA_MEM_TO_DEV, sprd_complete_tx_dma);
+}
+
+static void sprd_start_tx_dma(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (port->x_char) {
+		serial_out(port, SPRD_TXD, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		sprd_stop_tx_dma(port);
+		return;
+	}
+
+	if (sp->tx_dma.trans_len)
+		return;
+
+	if (sprd_tx_buf_remap(port) || sprd_tx_dma_config(port))
+		sp->tx_dma.trans_len = 0;
+}
+
+static void sprd_rx_full_thld(struct uart_port *port, u32 thld)
+{
+	u32 val = serial_in(port, SPRD_CTL2);
+
+	val &= ~THLD_RX_FULL_MASK;
+	val |= thld & THLD_RX_FULL_MASK;
+	serial_out(port, SPRD_CTL2, val);
+}
+
+static int sprd_rx_alloc_buf(struct sprd_uart_port *sp)
+{
+	sp->rx_dma.virt = dma_alloc_coherent(sp->port.dev, SPRD_UART_RX_SIZE,
+					     &sp->rx_dma.phys_addr, GFP_KERNEL);
+	if (!sp->rx_dma.virt)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void sprd_rx_free_buf(struct sprd_uart_port *sp)
+{
+	if (sp->rx_dma.virt)
+		dma_free_coherent(sp->port.dev, SPRD_UART_RX_SIZE,
+				  sp->rx_dma.virt, sp->rx_dma.phys_addr);
+	sp->rx_dma.virt = NULL;
+}
+
+static int sprd_rx_dma_config(struct uart_port *port, u32 burst)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct dma_slave_config cfg = {
+		.src_addr = port->mapbase + SPRD_RXD,
+		.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+		.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+		.src_maxburst = burst,
+	};
+
+	return dmaengine_slave_config(sp->rx_dma.chn, &cfg);
+}
+
+static void sprd_uart_dma_rx(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct tty_port *tty = &port->state->port;
+
+	port->icount.rx += sp->rx_dma.trans_len;
+	tty_insert_flip_string(tty, sp->rx_buf_tail, sp->rx_dma.trans_len);
+	tty_flip_buffer_push(tty);
+}
+
+static void sprd_uart_dma_irq(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(sp->rx_dma.chn,
+				     sp->rx_dma.cookie, &state);
+	if (status == DMA_ERROR)
+		sprd_stop_rx(port);
+
+	if (!state.residue && sp->pos == sp->rx_dma.phys_addr)
+		return;
+
+	if (!state.residue) {
+		sp->rx_dma.trans_len = SPRD_UART_RX_SIZE +
+			sp->rx_dma.phys_addr - sp->pos;
+		sp->pos = sp->rx_dma.phys_addr;
+	} else {
+		sp->rx_dma.trans_len = state.residue - sp->pos;
+		sp->pos = state.residue;
+	}
+
+	sprd_uart_dma_rx(port);
+	sp->rx_buf_tail += sp->rx_dma.trans_len;
+}
+
+static void sprd_complete_rx_dma(void *data)
+{
+	struct uart_port *port = (struct uart_port *)data;
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	struct dma_tx_state state;
+	enum dma_status status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	status = dmaengine_tx_status(sp->rx_dma.chn,
+				     sp->rx_dma.cookie, &state);
+	if (status != DMA_COMPLETE) {
+		sprd_stop_rx(port);
+		spin_unlock_irqrestore(&port->lock, flags);
+		return;
+	}
+
+	if (sp->pos != sp->rx_dma.phys_addr) {
+		sp->rx_dma.trans_len =  SPRD_UART_RX_SIZE +
+			sp->rx_dma.phys_addr - sp->pos;
+		sprd_uart_dma_rx(port);
+		sp->rx_buf_tail += sp->rx_dma.trans_len;
+	}
+
+	if (sprd_start_dma_rx(port))
+		sprd_stop_rx(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int sprd_start_dma_rx(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+	int ret;
+
+	if (!sp->rx_dma.enable)
+		return 0;
+
+	sp->pos = sp->rx_dma.phys_addr;
+	sp->rx_buf_tail = sp->rx_dma.virt;
+	sprd_rx_full_thld(port, SPRD_RX_FIFO_FULL);
+	ret = sprd_rx_dma_config(port, SPRD_RX_DMA_STEP);
+	if (ret)
+		return ret;
+
+	return sprd_uart_dma_submit(port, &sp->rx_dma, SPRD_UART_RX_SIZE,
+				    DMA_DEV_TO_MEM, sprd_complete_rx_dma);
+}
+
+static void sprd_release_dma(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+
+	sprd_uart_dma_enable(port, false);
+
+	if (sp->rx_dma.enable)
+		dma_release_channel(sp->rx_dma.chn);
+
+	if (sp->tx_dma.enable)
+		dma_release_channel(sp->tx_dma.chn);
+
+	sp->tx_dma.enable = false;
+	sp->rx_dma.enable = false;
+}
+
+static void sprd_request_dma(struct uart_port *port)
+{
+	struct sprd_uart_port *sp =
+		container_of(port, struct sprd_uart_port, port);
+
+	sp->tx_dma.enable = true;
+	sp->rx_dma.enable = true;
+
+	sp->tx_dma.chn = dma_request_chan(port->dev, "tx");
+	if (IS_ERR(sp->tx_dma.chn)) {
+		dev_err(port->dev, "request TX DMA channel failed, ret = %ld\n",
+			PTR_ERR(sp->tx_dma.chn));
+		sp->tx_dma.enable = false;
+	}
+
+	sp->rx_dma.chn = dma_request_chan(port->dev, "rx");
+	if (IS_ERR(sp->rx_dma.chn)) {
+		dev_err(port->dev, "request RX DMA channel failed, ret = %ld\n",
+			PTR_ERR(sp->rx_dma.chn));
+		sp->rx_dma.enable = false;
+	}
+}
+
+static void sprd_stop_tx(struct uart_port *port)
+{
+	struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port,
+						 port);
+	unsigned int ien, iclr;
+
+	if (sp->tx_dma.enable) {
+		sprd_stop_tx_dma(port);
+		return;
+	}
+
+	iclr = serial_in(port, SPRD_ICLR);
+	ien = serial_in(port, SPRD_IEN);
+
+	iclr |= SPRD_IEN_TX_EMPTY;
+	ien &= ~SPRD_IEN_TX_EMPTY;
+
+	serial_out(port, SPRD_IEN, ien);
+	serial_out(port, SPRD_ICLR, iclr);
+}
+
+static void sprd_start_tx(struct uart_port *port)
+{
+	struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port,
+						 port);
+	unsigned int ien;
+
+	if (sp->tx_dma.enable) {
+		sprd_start_tx_dma(port);
+		return;
+	}
+
+	ien = serial_in(port, SPRD_IEN);
+	if (!(ien & SPRD_IEN_TX_EMPTY)) {
+		ien |= SPRD_IEN_TX_EMPTY;
+		serial_out(port, SPRD_IEN, ien);
+	}
+}
+
+/* The Sprd serial does not support this function. */
+static void sprd_break_ctl(struct uart_port *port, int break_state)
+{
+	/* nothing to do */
+}
+
+static int handle_lsr_errors(struct uart_port *port,
+			     u8 *flag,
+			     unsigned int *lsr)
+{
+	int ret = 0;
+
+	/* statistics */
+	if (*lsr & SPRD_LSR_BI) {
+		*lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
+		port->icount.brk++;
+		ret = uart_handle_break(port);
+		if (ret)
+			return ret;
+	} else if (*lsr & SPRD_LSR_PE)
+		port->icount.parity++;
+	else if (*lsr & SPRD_LSR_FE)
+		port->icount.frame++;
+	if (*lsr & SPRD_LSR_OE)
+		port->icount.overrun++;
+
+	/* mask off conditions which should be ignored */
+	*lsr &= port->read_status_mask;
+	if (*lsr & SPRD_LSR_BI)
+		*flag = TTY_BREAK;
+	else if (*lsr & SPRD_LSR_PE)
+		*flag = TTY_PARITY;
+	else if (*lsr & SPRD_LSR_FE)
+		*flag = TTY_FRAME;
+
+	return ret;
+}
+
+static inline void sprd_rx(struct uart_port *port)
+{
+	struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port,
+						 port);
+	struct tty_port *tty = &port->state->port;
+	unsigned int lsr, max_count = SPRD_TIMEOUT;
+	u8 ch, flag;
+
+	if (sp->rx_dma.enable) {
+		sprd_uart_dma_irq(port);
+		return;
+	}
+
+	while ((serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) &&
+	       max_count--) {
+		lsr = serial_in(port, SPRD_LSR);
+		ch = serial_in(port, SPRD_RXD);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE |
+			   SPRD_LSR_FE | SPRD_LSR_OE))
+			if (handle_lsr_errors(port, &flag, &lsr))
+				continue;
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
+	}
+
+	tty_flip_buffer_push(tty);
+}
+
+static inline void sprd_tx(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx_limited(port, ch, THLD_TX_EMPTY,
+		true,
+		serial_out(port, SPRD_TXD, ch),
+		({}));
+}
+
+/* this handles the interrupt from one port */
+static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned int ims;
+
+	spin_lock(&port->lock);
+
+	ims = serial_in(port, SPRD_IMSR);
+
+	if (!ims) {
+		spin_unlock(&port->lock);
+		return IRQ_NONE;
+	}
+
+	if (ims & SPRD_IMSR_TIMEOUT)
+		serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT);
+
+	if (ims & SPRD_IMSR_BREAK_DETECT)
+		serial_out(port, SPRD_ICLR, SPRD_IMSR_BREAK_DETECT);
+
+	if (ims & (SPRD_IMSR_RX_FIFO_FULL | SPRD_IMSR_BREAK_DETECT |
+		   SPRD_IMSR_TIMEOUT))
+		sprd_rx(port);
+
+	if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
+		sprd_tx(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void sprd_uart_dma_startup(struct uart_port *port,
+				  struct sprd_uart_port *sp)
+{
+	int ret;
+
+	sprd_request_dma(port);
+	if (!(sp->rx_dma.enable || sp->tx_dma.enable))
+		return;
+
+	ret = sprd_start_dma_rx(port);
+	if (ret) {
+		sp->rx_dma.enable = false;
+		dma_release_channel(sp->rx_dma.chn);
+		dev_warn(port->dev, "fail to start RX dma mode\n");
+	}
+
+	sprd_uart_dma_enable(port, true);
+}
+
+static int sprd_startup(struct uart_port *port)
+{
+	int ret = 0;
+	unsigned int ien, fc;
+	unsigned int timeout;
+	struct sprd_uart_port *sp;
+	unsigned long flags;
+
+	serial_out(port, SPRD_CTL2,
+		   THLD_TX_EMPTY << THLD_TX_EMPTY_SHIFT | THLD_RX_FULL);
+
+	/* clear rx fifo */
+	timeout = SPRD_TIMEOUT;
+	while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK)
+		serial_in(port, SPRD_RXD);
+
+	/* clear tx fifo */
+	timeout = SPRD_TIMEOUT;
+	while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
+		cpu_relax();
+
+	/* clear interrupt */
+	serial_out(port, SPRD_IEN, 0);
+	serial_out(port, SPRD_ICLR, ~0);
+
+	/* allocate irq */
+	sp = container_of(port, struct sprd_uart_port, port);
+	snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
+
+	sprd_uart_dma_startup(port, sp);
+
+	ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
+			       IRQF_SHARED, sp->name, port);
+	if (ret) {
+		dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
+			port->irq, ret);
+		return ret;
+	}
+	fc = serial_in(port, SPRD_CTL1);
+	fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
+	serial_out(port, SPRD_CTL1, fc);
+
+	/* enable interrupt */
+	spin_lock_irqsave(&port->lock, flags);
+	ien = serial_in(port, SPRD_IEN);
+	ien |= SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
+	if (!sp->rx_dma.enable)
+		ien |= SPRD_IEN_RX_FULL;
+	serial_out(port, SPRD_IEN, ien);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void sprd_shutdown(struct uart_port *port)
+{
+	sprd_release_dma(port);
+	serial_out(port, SPRD_IEN, 0);
+	serial_out(port, SPRD_ICLR, ~0);
+	devm_free_irq(port->dev, port->irq, port);
+}
+
+static void sprd_set_termios(struct uart_port *port, struct ktermios *termios,
+		             const struct ktermios *old)
+{
+	unsigned int baud, quot;
+	unsigned int lcr = 0, fc;
+	unsigned long flags;
+
+	/* ask the core to calculate the divisor for us */
+	baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT);
+
+	quot = port->uartclk / baud;
+
+	/* set data length */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr |= SPRD_LCR_DATA_LEN5;
+		break;
+	case CS6:
+		lcr |= SPRD_LCR_DATA_LEN6;
+		break;
+	case CS7:
+		lcr |= SPRD_LCR_DATA_LEN7;
+		break;
+	case CS8:
+	default:
+		lcr |= SPRD_LCR_DATA_LEN8;
+		break;
+	}
+
+	/* calculate stop bits */
+	lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
+	if (termios->c_cflag & CSTOPB)
+		lcr |= SPRD_LCR_STOP_2BIT;
+	else
+		lcr |= SPRD_LCR_STOP_1BIT;
+
+	/* calculate parity */
+	lcr &= ~SPRD_LCR_PARITY;
+	termios->c_cflag &= ~CMSPAR;	/* no support mark/space */
+	if (termios->c_cflag & PARENB) {
+		lcr |= SPRD_LCR_PARITY_EN;
+		if (termios->c_cflag & PARODD)
+			lcr |= SPRD_LCR_ODD_PAR;
+		else
+			lcr |= SPRD_LCR_EVEN_PAR;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = SPRD_LSR_OE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= SPRD_LSR_BI;
+
+	/* characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= SPRD_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= SPRD_LSR_OE;
+	}
+
+	/* flow control */
+	fc = serial_in(port, SPRD_CTL1);
+	fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
+	if (termios->c_cflag & CRTSCTS) {
+		fc |= RX_HW_FLOW_CTL_THLD;
+		fc |= RX_HW_FLOW_CTL_EN;
+		fc |= TX_HW_FLOW_CTL_EN;
+	}
+
+	/* clock divider bit0~bit15 */
+	serial_out(port, SPRD_CLKD0, quot & SPRD_CLKD0_MASK);
+
+	/* clock divider bit16~bit20 */
+	serial_out(port, SPRD_CLKD1,
+		   (quot & SPRD_CLKD1_MASK) >> SPRD_CLKD1_SHIFT);
+	serial_out(port, SPRD_LCR, lcr);
+	fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
+	serial_out(port, SPRD_CTL1, fc);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *sprd_type(struct uart_port *port)
+{
+	return "SPX";
+}
+
+static void sprd_release_port(struct uart_port *port)
+{
+	/* nothing to do */
+}
+
+static int sprd_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sprd_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_SPRD;
+}
+
+static int sprd_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (ser->type != PORT_SPRD)
+		return -EINVAL;
+	if (port->irq != ser->irq)
+		return -EINVAL;
+	if (port->iotype != ser->io_type)
+		return -EINVAL;
+	return 0;
+}
+
+static void sprd_pm(struct uart_port *port, unsigned int state,
+		unsigned int oldstate)
+{
+	struct sprd_uart_port *sup =
+		container_of(port, struct sprd_uart_port, port);
+
+	switch (state) {
+	case UART_PM_STATE_ON:
+		clk_prepare_enable(sup->clk);
+		break;
+	case UART_PM_STATE_OFF:
+		clk_disable_unprepare(sup->clk);
+		break;
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int sprd_poll_init(struct uart_port *port)
+{
+	if (port->state->pm_state != UART_PM_STATE_ON) {
+		sprd_pm(port, UART_PM_STATE_ON, 0);
+		port->state->pm_state = UART_PM_STATE_ON;
+	}
+
+	return 0;
+}
+
+static int sprd_poll_get_char(struct uart_port *port)
+{
+	while (!(serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK))
+		cpu_relax();
+
+	return serial_in(port, SPRD_RXD);
+}
+
+static void sprd_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+	while (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK)
+		cpu_relax();
+
+	serial_out(port, SPRD_TXD, ch);
+}
+#endif
+
+static const struct uart_ops serial_sprd_ops = {
+	.tx_empty = sprd_tx_empty,
+	.get_mctrl = sprd_get_mctrl,
+	.set_mctrl = sprd_set_mctrl,
+	.stop_tx = sprd_stop_tx,
+	.start_tx = sprd_start_tx,
+	.stop_rx = sprd_stop_rx,
+	.break_ctl = sprd_break_ctl,
+	.startup = sprd_startup,
+	.shutdown = sprd_shutdown,
+	.set_termios = sprd_set_termios,
+	.type = sprd_type,
+	.release_port = sprd_release_port,
+	.request_port = sprd_request_port,
+	.config_port = sprd_config_port,
+	.verify_port = sprd_verify_port,
+	.pm = sprd_pm,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init	= sprd_poll_init,
+	.poll_get_char	= sprd_poll_get_char,
+	.poll_put_char	= sprd_poll_put_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_SPRD_CONSOLE
+static void wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int status, tmout = 10000;
+
+	/* wait up to 10ms for the character(s) to be sent */
+	do {
+		status = serial_in(port, SPRD_STS1);
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (status & SPRD_TX_FIFO_CNT_MASK);
+}
+
+static void sprd_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	wait_for_xmitr(port);
+	serial_out(port, SPRD_TXD, ch);
+}
+
+static void sprd_console_write(struct console *co, const char *s,
+			       unsigned int count)
+{
+	struct uart_port *port = &sprd_port[co->index]->port;
+	int locked = 1;
+	unsigned long flags;
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	uart_console_write(port, s, count, sprd_console_putchar);
+
+	/* wait for transmitter to become empty */
+	wait_for_xmitr(port);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int sprd_console_setup(struct console *co, char *options)
+{
+	struct sprd_uart_port *sprd_uart_port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= UART_NR_MAX || co->index < 0)
+		co->index = 0;
+
+	sprd_uart_port = sprd_port[co->index];
+	if (!sprd_uart_port || !sprd_uart_port->port.membase) {
+		pr_info("serial port %d not yet initialized\n", co->index);
+		return -ENODEV;
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&sprd_uart_port->port, co, baud,
+				parity, bits, flow);
+}
+
+static struct uart_driver sprd_uart_driver;
+static struct console sprd_console = {
+	.name = SPRD_TTY_NAME,
+	.write = sprd_console_write,
+	.device = uart_console_device,
+	.setup = sprd_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &sprd_uart_driver,
+};
+
+static int __init sprd_serial_console_init(void)
+{
+	register_console(&sprd_console);
+	return 0;
+}
+console_initcall(sprd_serial_console_init);
+
+#define SPRD_CONSOLE	(&sprd_console)
+
+/* Support for earlycon */
+static void sprd_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned int timeout = SPRD_TIMEOUT;
+
+	while (timeout-- &&
+	       !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
+		cpu_relax();
+
+	writeb(c, port->membase + SPRD_TXD);
+}
+
+static void sprd_early_write(struct console *con, const char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, sprd_putc);
+}
+
+static int __init sprd_early_console_setup(struct earlycon_device *device,
+					   const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = sprd_early_write;
+	return 0;
+}
+OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
+		    sprd_early_console_setup);
+
+#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
+#define SPRD_CONSOLE		NULL
+#endif
+
+static struct uart_driver sprd_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "sprd_serial",
+	.dev_name = SPRD_TTY_NAME,
+	.major = 0,
+	.minor = 0,
+	.nr = UART_NR_MAX,
+	.cons = SPRD_CONSOLE,
+};
+
+static int sprd_remove(struct platform_device *dev)
+{
+	struct sprd_uart_port *sup = platform_get_drvdata(dev);
+
+	if (sup) {
+		uart_remove_one_port(&sprd_uart_driver, &sup->port);
+		sprd_port[sup->port.line] = NULL;
+		sprd_rx_free_buf(sup);
+		sprd_ports_num--;
+	}
+
+	if (!sprd_ports_num)
+		uart_unregister_driver(&sprd_uart_driver);
+
+	return 0;
+}
+
+static bool sprd_uart_is_console(struct uart_port *uport)
+{
+	struct console *cons = sprd_uart_driver.cons;
+
+	if ((cons && cons->index >= 0 && cons->index == uport->line) ||
+	    of_console_check(uport->dev->of_node, SPRD_TTY_NAME, uport->line))
+		return true;
+
+	return false;
+}
+
+static int sprd_clk_init(struct uart_port *uport)
+{
+	struct clk *clk_uart, *clk_parent;
+	struct sprd_uart_port *u = container_of(uport, struct sprd_uart_port, port);
+
+	clk_uart = devm_clk_get(uport->dev, "uart");
+	if (IS_ERR(clk_uart)) {
+		dev_warn(uport->dev, "uart%d can't get uart clock\n",
+			 uport->line);
+		clk_uart = NULL;
+	}
+
+	clk_parent = devm_clk_get(uport->dev, "source");
+	if (IS_ERR(clk_parent)) {
+		dev_warn(uport->dev, "uart%d can't get source clock\n",
+			 uport->line);
+		clk_parent = NULL;
+	}
+
+	if (!clk_uart || clk_set_parent(clk_uart, clk_parent))
+		uport->uartclk = SPRD_DEFAULT_SOURCE_CLK;
+	else
+		uport->uartclk = clk_get_rate(clk_uart);
+
+	u->clk = devm_clk_get(uport->dev, "enable");
+	if (IS_ERR(u->clk)) {
+		if (PTR_ERR(u->clk) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		dev_warn(uport->dev, "uart%d can't get enable clock\n",
+			uport->line);
+
+		/* To keep console alive even if the error occurred */
+		if (!sprd_uart_is_console(uport))
+			return PTR_ERR(u->clk);
+
+		u->clk = NULL;
+	}
+
+	return 0;
+}
+
+static int sprd_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct uart_port *up;
+	struct sprd_uart_port *sport;
+	int irq;
+	int index;
+	int ret;
+
+	index = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (index < 0 || index >= UART_NR_MAX) {
+		dev_err(&pdev->dev, "got a wrong serial alias id %d\n", index);
+		return -EINVAL;
+	}
+
+	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	up = &sport->port;
+	up->dev = &pdev->dev;
+	up->line = index;
+	up->type = PORT_SPRD;
+	up->iotype = UPIO_MEM;
+	up->uartclk = SPRD_DEF_RATE;
+	up->fifosize = SPRD_FIFO_SIZE;
+	up->ops = &serial_sprd_ops;
+	up->flags = UPF_BOOT_AUTOCONF;
+	up->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SPRD_CONSOLE);
+
+	ret = sprd_clk_init(up);
+	if (ret)
+		return ret;
+
+	up->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(up->membase))
+		return PTR_ERR(up->membase);
+
+	up->mapbase = res->start;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	up->irq = irq;
+
+	/*
+	 * Allocate one dma buffer to prepare for receive transfer, in case
+	 * memory allocation failure at runtime.
+	 */
+	ret = sprd_rx_alloc_buf(sport);
+	if (ret)
+		return ret;
+
+	if (!sprd_ports_num) {
+		ret = uart_register_driver(&sprd_uart_driver);
+		if (ret < 0) {
+			pr_err("Failed to register SPRD-UART driver\n");
+			goto free_rx_buf;
+		}
+	}
+
+	sprd_ports_num++;
+	sprd_port[index] = sport;
+
+	ret = uart_add_one_port(&sprd_uart_driver, up);
+	if (ret)
+		goto clean_port;
+
+	platform_set_drvdata(pdev, up);
+
+	return 0;
+
+clean_port:
+	sprd_port[index] = NULL;
+	if (--sprd_ports_num == 0)
+		uart_unregister_driver(&sprd_uart_driver);
+free_rx_buf:
+	sprd_rx_free_buf(sport);
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int sprd_suspend(struct device *dev)
+{
+	struct sprd_uart_port *sup = dev_get_drvdata(dev);
+
+	uart_suspend_port(&sprd_uart_driver, &sup->port);
+
+	return 0;
+}
+
+static int sprd_resume(struct device *dev)
+{
+	struct sprd_uart_port *sup = dev_get_drvdata(dev);
+
+	uart_resume_port(&sprd_uart_driver, &sup->port);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
+
+static const struct of_device_id serial_ids[] = {
+	{.compatible = "sprd,sc9836-uart",},
+	{}
+};
+MODULE_DEVICE_TABLE(of, serial_ids);
+
+static struct platform_driver sprd_platform_driver = {
+	.probe		= sprd_probe,
+	.remove		= sprd_remove,
+	.driver		= {
+		.name	= "sprd_serial",
+		.of_match_table = serial_ids,
+		.pm	= &sprd_pm_ops,
+	},
+};
+
+module_platform_driver(sprd_platform_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
new file mode 100644
index 000000000..92b9f6894
--- /dev/null
+++ b/drivers/tty/serial/st-asc.c
@@ -0,0 +1,974 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * st-asc.c: ST Asynchronous serial controller (ASC) driver
+ *
+ * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
+ */
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/serial_core.h>
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+
+#define DRIVER_NAME "st-asc"
+#define ASC_SERIAL_NAME "ttyAS"
+#define ASC_FIFO_SIZE 16
+#define ASC_MAX_PORTS 8
+
+/* Pinctrl states */
+#define DEFAULT		0
+#define NO_HW_FLOWCTRL	1
+
+struct asc_port {
+	struct uart_port port;
+	struct gpio_desc *rts;
+	struct clk *clk;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *states[2];
+	unsigned int hw_flow_control:1;
+	unsigned int force_m1:1;
+};
+
+static struct asc_port asc_ports[ASC_MAX_PORTS];
+static struct uart_driver asc_uart_driver;
+
+/*---- UART Register definitions ------------------------------*/
+
+/* Register offsets */
+
+#define ASC_BAUDRATE			0x00
+#define ASC_TXBUF			0x04
+#define ASC_RXBUF			0x08
+#define ASC_CTL				0x0C
+#define ASC_INTEN			0x10
+#define ASC_STA				0x14
+#define ASC_GUARDTIME			0x18
+#define ASC_TIMEOUT			0x1C
+#define ASC_TXRESET			0x20
+#define ASC_RXRESET			0x24
+#define ASC_RETRIES			0x28
+
+/* ASC_RXBUF */
+#define ASC_RXBUF_PE			0x100
+#define ASC_RXBUF_FE			0x200
+/*
+ * Some of status comes from higher bits of the character and some come from
+ * the status register. Combining both of them in to single status using dummy
+ * bits.
+ */
+#define ASC_RXBUF_DUMMY_RX		0x10000
+#define ASC_RXBUF_DUMMY_BE		0x20000
+#define ASC_RXBUF_DUMMY_OE		0x40000
+
+/* ASC_CTL */
+
+#define ASC_CTL_MODE_MSK		0x0007
+#define  ASC_CTL_MODE_8BIT		0x0001
+#define  ASC_CTL_MODE_7BIT_PAR		0x0003
+#define  ASC_CTL_MODE_9BIT		0x0004
+#define  ASC_CTL_MODE_8BIT_WKUP		0x0005
+#define  ASC_CTL_MODE_8BIT_PAR		0x0007
+#define ASC_CTL_STOP_MSK		0x0018
+#define  ASC_CTL_STOP_HALFBIT		0x0000
+#define  ASC_CTL_STOP_1BIT		0x0008
+#define  ASC_CTL_STOP_1_HALFBIT		0x0010
+#define  ASC_CTL_STOP_2BIT		0x0018
+#define ASC_CTL_PARITYODD		0x0020
+#define ASC_CTL_LOOPBACK		0x0040
+#define ASC_CTL_RUN			0x0080
+#define ASC_CTL_RXENABLE		0x0100
+#define ASC_CTL_SCENABLE		0x0200
+#define ASC_CTL_FIFOENABLE		0x0400
+#define ASC_CTL_CTSENABLE		0x0800
+#define ASC_CTL_BAUDMODE		0x1000
+
+/* ASC_GUARDTIME */
+
+#define ASC_GUARDTIME_MSK		0x00FF
+
+/* ASC_INTEN */
+
+#define ASC_INTEN_RBE			0x0001
+#define ASC_INTEN_TE			0x0002
+#define ASC_INTEN_THE			0x0004
+#define ASC_INTEN_PE			0x0008
+#define ASC_INTEN_FE			0x0010
+#define ASC_INTEN_OE			0x0020
+#define ASC_INTEN_TNE			0x0040
+#define ASC_INTEN_TOI			0x0080
+#define ASC_INTEN_RHF			0x0100
+
+/* ASC_RETRIES */
+
+#define ASC_RETRIES_MSK			0x00FF
+
+/* ASC_RXBUF */
+
+#define ASC_RXBUF_MSK			0x03FF
+
+/* ASC_STA */
+
+#define ASC_STA_RBF			0x0001
+#define ASC_STA_TE			0x0002
+#define ASC_STA_THE			0x0004
+#define ASC_STA_PE			0x0008
+#define ASC_STA_FE			0x0010
+#define ASC_STA_OE			0x0020
+#define ASC_STA_TNE			0x0040
+#define ASC_STA_TOI			0x0080
+#define ASC_STA_RHF			0x0100
+#define ASC_STA_TF			0x0200
+#define ASC_STA_NKD			0x0400
+
+/* ASC_TIMEOUT */
+
+#define ASC_TIMEOUT_MSK			0x00FF
+
+/* ASC_TXBUF */
+
+#define ASC_TXBUF_MSK			0x01FF
+
+/*---- Inline function definitions ---------------------------*/
+
+static inline struct asc_port *to_asc_port(struct uart_port *port)
+{
+	return container_of(port, struct asc_port, port);
+}
+
+static inline u32 asc_in(struct uart_port *port, u32 offset)
+{
+#ifdef readl_relaxed
+	return readl_relaxed(port->membase + offset);
+#else
+	return readl(port->membase + offset);
+#endif
+}
+
+static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
+{
+#ifdef writel_relaxed
+	writel_relaxed(value, port->membase + offset);
+#else
+	writel(value, port->membase + offset);
+#endif
+}
+
+/*
+ * Some simple utility functions to enable and disable interrupts.
+ * Note that these need to be called with interrupts disabled.
+ */
+static inline void asc_disable_tx_interrupts(struct uart_port *port)
+{
+	u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE;
+	asc_out(port, ASC_INTEN, intenable);
+	(void)asc_in(port, ASC_INTEN);	/* Defeat bus write posting */
+}
+
+static inline void asc_enable_tx_interrupts(struct uart_port *port)
+{
+	u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE;
+	asc_out(port, ASC_INTEN, intenable);
+}
+
+static inline void asc_disable_rx_interrupts(struct uart_port *port)
+{
+	u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE;
+	asc_out(port, ASC_INTEN, intenable);
+	(void)asc_in(port, ASC_INTEN);	/* Defeat bus write posting */
+}
+
+static inline void asc_enable_rx_interrupts(struct uart_port *port)
+{
+	u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE;
+	asc_out(port, ASC_INTEN, intenable);
+}
+
+static inline u32 asc_txfifo_is_empty(struct uart_port *port)
+{
+	return asc_in(port, ASC_STA) & ASC_STA_TE;
+}
+
+static inline u32 asc_txfifo_is_half_empty(struct uart_port *port)
+{
+	return asc_in(port, ASC_STA) & ASC_STA_THE;
+}
+
+static inline const char *asc_port_name(struct uart_port *port)
+{
+	return to_platform_device(port->dev)->name;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * This section contains code to support the use of the ASC as a
+ * generic serial port.
+ */
+
+static inline unsigned asc_hw_txroom(struct uart_port *port)
+{
+	u32 status = asc_in(port, ASC_STA);
+
+	if (status & ASC_STA_THE)
+		return port->fifosize / 2;
+	else if (!(status & ASC_STA_TF))
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Start transmitting chars.
+ * This is called from both interrupt and task level.
+ * Either way interrupts are disabled.
+ */
+static void asc_transmit_chars(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx_limited(port, ch, asc_hw_txroom(port),
+		true,
+		asc_out(port, ASC_TXBUF, ch),
+		({}));
+}
+
+static void asc_receive_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned long status, mode;
+	unsigned long c = 0;
+	u8 flag;
+	bool ignore_pe = false;
+
+	/*
+	 * Datasheet states: If the MODE field selects an 8-bit frame then
+	 * this [parity error] bit is undefined. Software should ignore this
+	 * bit when reading 8-bit frames.
+	 */
+	mode = asc_in(port, ASC_CTL) & ASC_CTL_MODE_MSK;
+	if (mode == ASC_CTL_MODE_8BIT || mode == ASC_CTL_MODE_8BIT_PAR)
+		ignore_pe = true;
+
+	if (irqd_is_wakeup_set(irq_get_irq_data(port->irq)))
+		pm_wakeup_event(tport->tty->dev, 0);
+
+	while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) {
+		c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX;
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (status & ASC_STA_OE || c & ASC_RXBUF_FE ||
+		    (c & ASC_RXBUF_PE && !ignore_pe)) {
+
+			if (c & ASC_RXBUF_FE) {
+				if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) {
+					port->icount.brk++;
+					if (uart_handle_break(port))
+						continue;
+					c |= ASC_RXBUF_DUMMY_BE;
+				} else {
+					port->icount.frame++;
+				}
+			} else if (c & ASC_RXBUF_PE) {
+				port->icount.parity++;
+			}
+			/*
+			 * Reading any data from the RX FIFO clears the
+			 * overflow error condition.
+			 */
+			if (status & ASC_STA_OE) {
+				port->icount.overrun++;
+				c |= ASC_RXBUF_DUMMY_OE;
+			}
+
+			c &= port->read_status_mask;
+
+			if (c & ASC_RXBUF_DUMMY_BE)
+				flag = TTY_BREAK;
+			else if (c & ASC_RXBUF_PE)
+				flag = TTY_PARITY;
+			else if (c & ASC_RXBUF_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, c & 0xff))
+			continue;
+
+		uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag);
+	}
+
+	/* Tell the rest of the system the news. New characters! */
+	tty_flip_buffer_push(tport);
+}
+
+static irqreturn_t asc_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	u32 status;
+
+	spin_lock(&port->lock);
+
+	status = asc_in(port, ASC_STA);
+
+	if (status & ASC_STA_RBF) {
+		/* Receive FIFO not empty */
+		asc_receive_chars(port);
+	}
+
+	if ((status & ASC_STA_THE) &&
+	    (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) {
+		/* Transmitter FIFO at least half empty */
+		asc_transmit_chars(port);
+	}
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * UART Functions
+ */
+
+static unsigned int asc_tx_empty(struct uart_port *port)
+{
+	return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
+}
+
+static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct asc_port *ascport = to_asc_port(port);
+
+	/*
+	 * This routine is used for seting signals of: DTR, DCD, CTS and RTS.
+	 * We use ASC's hardware for CTS/RTS when hardware flow-control is
+	 * enabled, however if the RTS line is required for another purpose,
+	 * commonly controlled using HUP from userspace, then we need to toggle
+	 * it manually, using GPIO.
+	 *
+	 * Some boards also have DTR and DCD implemented using PIO pins, code to
+	 * do this should be hooked in here.
+	 */
+
+	if (!ascport->rts)
+		return;
+
+	/* If HW flow-control is enabled, we can't fiddle with the RTS line */
+	if (asc_in(port, ASC_CTL) & ASC_CTL_CTSENABLE)
+		return;
+
+	gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
+}
+
+static unsigned int asc_get_mctrl(struct uart_port *port)
+{
+	/*
+	 * This routine is used for geting signals of: DTR, DCD, DSR, RI,
+	 * and CTS/RTS
+	 */
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/* There are probably characters waiting to be transmitted. */
+static void asc_start_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (!uart_circ_empty(xmit))
+		asc_enable_tx_interrupts(port);
+}
+
+/* Transmit stop */
+static void asc_stop_tx(struct uart_port *port)
+{
+	asc_disable_tx_interrupts(port);
+}
+
+/* Receive stop */
+static void asc_stop_rx(struct uart_port *port)
+{
+	asc_disable_rx_interrupts(port);
+}
+
+/* Handle breaks - ignored by us */
+static void asc_break_ctl(struct uart_port *port, int break_state)
+{
+	/* Nothing here yet .. */
+}
+
+/*
+ * Enable port for reception.
+ */
+static int asc_startup(struct uart_port *port)
+{
+	if (request_irq(port->irq, asc_interrupt, 0,
+			asc_port_name(port), port)) {
+		dev_err(port->dev, "cannot allocate irq.\n");
+		return -ENODEV;
+	}
+
+	asc_transmit_chars(port);
+	asc_enable_rx_interrupts(port);
+
+	return 0;
+}
+
+static void asc_shutdown(struct uart_port *port)
+{
+	asc_disable_tx_interrupts(port);
+	asc_disable_rx_interrupts(port);
+	free_irq(port->irq, port);
+}
+
+static void asc_pm(struct uart_port *port, unsigned int state,
+		unsigned int oldstate)
+{
+	struct asc_port *ascport = to_asc_port(port);
+	unsigned long flags;
+	u32 ctl;
+
+	switch (state) {
+	case UART_PM_STATE_ON:
+		clk_prepare_enable(ascport->clk);
+		break;
+	case UART_PM_STATE_OFF:
+		/*
+		 * Disable the ASC baud rate generator, which is as close as
+		 * we can come to turning it off. Note this is not called with
+		 * the port spinlock held.
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+		ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
+		asc_out(port, ASC_CTL, ctl);
+		spin_unlock_irqrestore(&port->lock, flags);
+		clk_disable_unprepare(ascport->clk);
+		break;
+	}
+}
+
+static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
+			    const struct ktermios *old)
+{
+	struct asc_port *ascport = to_asc_port(port);
+	struct gpio_desc *gpiod;
+	unsigned int baud;
+	u32 ctrl_val;
+	tcflag_t cflag;
+	unsigned long flags;
+
+	/* Update termios to reflect hardware capabilities */
+	termios->c_cflag &= ~(CMSPAR |
+			 (ascport->hw_flow_control ? 0 : CRTSCTS));
+
+	port->uartclk = clk_get_rate(ascport->clk);
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+	cflag = termios->c_cflag;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* read control register */
+	ctrl_val = asc_in(port, ASC_CTL);
+
+	/* stop serial port and reset value */
+	asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN));
+	ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE;
+
+	/* reset fifo rx & tx */
+	asc_out(port, ASC_TXRESET, 1);
+	asc_out(port, ASC_RXRESET, 1);
+
+	/* set character length */
+	if ((cflag & CSIZE) == CS7) {
+		ctrl_val |= ASC_CTL_MODE_7BIT_PAR;
+		cflag |= PARENB;
+	} else {
+		ctrl_val |= (cflag & PARENB) ?  ASC_CTL_MODE_8BIT_PAR :
+						ASC_CTL_MODE_8BIT;
+		cflag &= ~CSIZE;
+		cflag |= CS8;
+	}
+	termios->c_cflag = cflag;
+
+	/* set stop bit */
+	ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;
+
+	/* odd parity */
+	if (cflag & PARODD)
+		ctrl_val |= ASC_CTL_PARITYODD;
+
+	/* hardware flow control */
+	if ((cflag & CRTSCTS)) {
+		ctrl_val |= ASC_CTL_CTSENABLE;
+
+		/* If flow-control selected, stop handling RTS manually */
+		if (ascport->rts) {
+			devm_gpiod_put(port->dev, ascport->rts);
+			ascport->rts = NULL;
+
+			pinctrl_select_state(ascport->pinctrl,
+					     ascport->states[DEFAULT]);
+		}
+	} else {
+		/* If flow-control disabled, it's safe to handle RTS manually */
+		if (!ascport->rts && ascport->states[NO_HW_FLOWCTRL]) {
+			pinctrl_select_state(ascport->pinctrl,
+					     ascport->states[NO_HW_FLOWCTRL]);
+
+			gpiod = devm_gpiod_get(port->dev, "rts", GPIOD_OUT_LOW);
+			if (!IS_ERR(gpiod)) {
+				gpiod_set_consumer_name(gpiod,
+						port->dev->of_node->name);
+				ascport->rts = gpiod;
+			}
+		}
+	}
+
+	if ((baud < 19200) && !ascport->force_m1) {
+		asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));
+	} else {
+		/*
+		 * MODE 1: recommended for high bit rates (above 19.2K)
+		 *
+		 *                   baudrate * 16 * 2^16
+		 * ASCBaudRate =   ------------------------
+		 *                          inputclock
+		 *
+		 * To keep maths inside 64bits, we divide inputclock by 16.
+		 */
+		u64 dividend = (u64)baud * (1 << 16);
+
+		do_div(dividend, port->uartclk / 16);
+		asc_out(port, ASC_BAUDRATE, dividend);
+		ctrl_val |= ASC_CTL_BAUDMODE;
+	}
+
+	uart_update_timeout(port, cflag, baud);
+
+	ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE;
+	if (termios->c_iflag & INPCK)
+		ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE;
+
+	/*
+	 * Characters to ignore
+	 */
+	ascport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
+	if (termios->c_iflag & IGNBRK) {
+		ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE;
+	}
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if (!(termios->c_cflag & CREAD))
+		ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX;
+
+	/* Set the timeout */
+	asc_out(port, ASC_TIMEOUT, 20);
+
+	/* write final value and enable port */
+	asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *asc_type(struct uart_port *port)
+{
+	return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
+}
+
+static void asc_release_port(struct uart_port *port)
+{
+}
+
+static int asc_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/*
+ * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set
+ * Set type field if successful
+ */
+static void asc_config_port(struct uart_port *port, int flags)
+{
+	if ((flags & UART_CONFIG_TYPE))
+		port->type = PORT_ASC;
+}
+
+static int
+asc_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* No user changeable parameters */
+	return -EINVAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int asc_get_poll_char(struct uart_port *port)
+{
+	if (!(asc_in(port, ASC_STA) & ASC_STA_RBF))
+		return NO_POLL_CHAR;
+
+	return asc_in(port, ASC_RXBUF);
+}
+
+static void asc_put_poll_char(struct uart_port *port, unsigned char c)
+{
+	while (!asc_txfifo_is_half_empty(port))
+		cpu_relax();
+	asc_out(port, ASC_TXBUF, c);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+/*---------------------------------------------------------------------*/
+
+static const struct uart_ops asc_uart_ops = {
+	.tx_empty	= asc_tx_empty,
+	.set_mctrl	= asc_set_mctrl,
+	.get_mctrl	= asc_get_mctrl,
+	.start_tx	= asc_start_tx,
+	.stop_tx	= asc_stop_tx,
+	.stop_rx	= asc_stop_rx,
+	.break_ctl	= asc_break_ctl,
+	.startup	= asc_startup,
+	.shutdown	= asc_shutdown,
+	.set_termios	= asc_set_termios,
+	.type		= asc_type,
+	.release_port	= asc_release_port,
+	.request_port	= asc_request_port,
+	.config_port	= asc_config_port,
+	.verify_port	= asc_verify_port,
+	.pm		= asc_pm,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = asc_get_poll_char,
+	.poll_put_char = asc_put_poll_char,
+#endif /* CONFIG_CONSOLE_POLL */
+};
+
+static int asc_init_port(struct asc_port *ascport,
+			  struct platform_device *pdev)
+{
+	struct uart_port *port = &ascport->port;
+	struct resource *res;
+	int ret;
+
+	port->iotype	= UPIO_MEM;
+	port->flags	= UPF_BOOT_AUTOCONF;
+	port->ops	= &asc_uart_ops;
+	port->fifosize	= ASC_FIFO_SIZE;
+	port->dev	= &pdev->dev;
+	port->irq	= platform_get_irq(pdev, 0);
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ST_ASC_CONSOLE);
+
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+	port->mapbase = res->start;
+
+	spin_lock_init(&port->lock);
+
+	ascport->clk = devm_clk_get(&pdev->dev, NULL);
+
+	if (WARN_ON(IS_ERR(ascport->clk)))
+		return -EINVAL;
+	/* ensure that clk rate is correct by enabling the clk */
+	ret = clk_prepare_enable(ascport->clk);
+	if (ret)
+		return ret;
+	ascport->port.uartclk = clk_get_rate(ascport->clk);
+	WARN_ON(ascport->port.uartclk == 0);
+	clk_disable_unprepare(ascport->clk);
+
+	ascport->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(ascport->pinctrl)) {
+		ret = PTR_ERR(ascport->pinctrl);
+		dev_err(&pdev->dev, "Failed to get Pinctrl: %d\n", ret);
+		return ret;
+	}
+
+	ascport->states[DEFAULT] =
+		pinctrl_lookup_state(ascport->pinctrl, "default");
+	if (IS_ERR(ascport->states[DEFAULT])) {
+		ret = PTR_ERR(ascport->states[DEFAULT]);
+		dev_err(&pdev->dev,
+			"Failed to look up Pinctrl state 'default': %d\n", ret);
+		return ret;
+	}
+
+	/* "no-hw-flowctrl" state is optional */
+	ascport->states[NO_HW_FLOWCTRL] =
+		pinctrl_lookup_state(ascport->pinctrl, "no-hw-flowctrl");
+	if (IS_ERR(ascport->states[NO_HW_FLOWCTRL]))
+		ascport->states[NO_HW_FLOWCTRL] = NULL;
+
+	return 0;
+}
+
+static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int id;
+
+	if (!np)
+		return NULL;
+
+	id = of_alias_get_id(np, "serial");
+	if (id < 0)
+		id = of_alias_get_id(np, ASC_SERIAL_NAME);
+
+	if (id < 0)
+		id = 0;
+
+	if (WARN_ON(id >= ASC_MAX_PORTS))
+		return NULL;
+
+	asc_ports[id].hw_flow_control = of_property_read_bool(np,
+							"uart-has-rtscts");
+	asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force-m1");
+	asc_ports[id].port.line = id;
+	asc_ports[id].rts = NULL;
+
+	return &asc_ports[id];
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id asc_match[] = {
+	{ .compatible = "st,asc", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, asc_match);
+#endif
+
+static int asc_serial_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct asc_port *ascport;
+
+	ascport = asc_of_get_asc_port(pdev);
+	if (!ascport)
+		return -ENODEV;
+
+	ret = asc_init_port(ascport, pdev);
+	if (ret)
+		return ret;
+
+	ret = uart_add_one_port(&asc_uart_driver, &ascport->port);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, &ascport->port);
+
+	return 0;
+}
+
+static int asc_serial_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&asc_uart_driver, port);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int asc_serial_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	return uart_suspend_port(&asc_uart_driver, port);
+}
+
+static int asc_serial_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	return uart_resume_port(&asc_uart_driver, port);
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+/*----------------------------------------------------------------------*/
+
+#ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
+static void asc_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned int timeout = 1000000;
+
+	/* Wait for upto 1 second in case flow control is stopping us. */
+	while (--timeout && !asc_txfifo_is_half_empty(port))
+		udelay(1);
+
+	asc_out(port, ASC_TXBUF, ch);
+}
+
+/*
+ *  Print a string to the serial port trying not to disturb
+ *  any possible real use of the port...
+ */
+
+static void asc_console_write(struct console *co, const char *s, unsigned count)
+{
+	struct uart_port *port = &asc_ports[co->index].port;
+	unsigned long flags;
+	unsigned long timeout = 1000000;
+	int locked = 1;
+	u32 intenable;
+
+	if (port->sysrq)
+		locked = 0; /* asc_interrupt has already claimed the lock */
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Disable interrupts so we don't get the IRQ line bouncing
+	 * up and down while interrupts are disabled.
+	 */
+	intenable = asc_in(port, ASC_INTEN);
+	asc_out(port, ASC_INTEN, 0);
+	(void)asc_in(port, ASC_INTEN);	/* Defeat bus write posting */
+
+	uart_console_write(port, s, count, asc_console_putchar);
+
+	while (--timeout && !asc_txfifo_is_empty(port))
+		udelay(1);
+
+	asc_out(port, ASC_INTEN, intenable);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int asc_console_setup(struct console *co, char *options)
+{
+	struct asc_port *ascport;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= ASC_MAX_PORTS)
+		return -ENODEV;
+
+	ascport = &asc_ports[co->index];
+
+	/*
+	 * This driver does not support early console initialization
+	 * (use ARM early printk support instead), so we only expect
+	 * this to be called during the uart port registration when the
+	 * driver gets probed and the port should be mapped at that point.
+	 */
+	if (ascport->port.mapbase == 0 || ascport->port.membase == NULL)
+		return -ENXIO;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&ascport->port, co, baud, parity, bits, flow);
+}
+
+static struct console asc_console = {
+	.name		= ASC_SERIAL_NAME,
+	.device		= uart_console_device,
+	.write		= asc_console_write,
+	.setup		= asc_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &asc_uart_driver,
+};
+
+#define ASC_SERIAL_CONSOLE (&asc_console)
+
+#else
+#define ASC_SERIAL_CONSOLE NULL
+#endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */
+
+static struct uart_driver asc_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= ASC_SERIAL_NAME,
+	.major		= 0,
+	.minor		= 0,
+	.nr		= ASC_MAX_PORTS,
+	.cons		= ASC_SERIAL_CONSOLE,
+};
+
+static const struct dev_pm_ops asc_serial_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
+};
+
+static struct platform_driver asc_serial_driver = {
+	.probe		= asc_serial_probe,
+	.remove		= asc_serial_remove,
+	.driver	= {
+		.name	= DRIVER_NAME,
+		.pm	= &asc_serial_pm_ops,
+		.of_match_table = of_match_ptr(asc_match),
+	},
+};
+
+static int __init asc_init(void)
+{
+	int ret;
+	static const char banner[] __initconst =
+		KERN_INFO "STMicroelectronics ASC driver initialized\n";
+
+	printk(banner);
+
+	ret = uart_register_driver(&asc_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&asc_serial_driver);
+	if (ret)
+		uart_unregister_driver(&asc_uart_driver);
+
+	return ret;
+}
+
+static void __exit asc_exit(void)
+{
+	platform_driver_unregister(&asc_serial_driver);
+	uart_unregister_driver(&asc_uart_driver);
+}
+
+module_init(asc_init);
+module_exit(asc_exit);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
+MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
new file mode 100644
index 000000000..b6f4f436a
--- /dev/null
+++ b/drivers/tty/serial/stm32-usart.c
@@ -0,0 +1,2171 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Copyright (C) STMicroelectronics SA 2017
+ * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ *	     Gerald Baeza <gerald.baeza@foss.st.com>
+ *	     Erwan Le Ray <erwan.leray@foss.st.com>
+ *
+ * Inspired by st-asc.c from STMicroelectronics (c)
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/dma-direction.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/spinlock.h>
+#include <linux/sysrq.h>
+#include <linux/tty_flip.h>
+#include <linux/tty.h>
+
+#include "serial_mctrl_gpio.h"
+#include "stm32-usart.h"
+
+
+/* Register offsets */
+static struct stm32_usart_info __maybe_unused stm32f4_info = {
+	.ofs = {
+		.isr	= 0x00,
+		.rdr	= 0x04,
+		.tdr	= 0x04,
+		.brr	= 0x08,
+		.cr1	= 0x0c,
+		.cr2	= 0x10,
+		.cr3	= 0x14,
+		.gtpr	= 0x18,
+		.rtor	= UNDEF_REG,
+		.rqr	= UNDEF_REG,
+		.icr	= UNDEF_REG,
+	},
+	.cfg = {
+		.uart_enable_bit = 13,
+		.has_7bits_data = false,
+		.fifosize = 1,
+	}
+};
+
+static struct stm32_usart_info __maybe_unused stm32f7_info = {
+	.ofs = {
+		.cr1	= 0x00,
+		.cr2	= 0x04,
+		.cr3	= 0x08,
+		.brr	= 0x0c,
+		.gtpr	= 0x10,
+		.rtor	= 0x14,
+		.rqr	= 0x18,
+		.isr	= 0x1c,
+		.icr	= 0x20,
+		.rdr	= 0x24,
+		.tdr	= 0x28,
+	},
+	.cfg = {
+		.uart_enable_bit = 0,
+		.has_7bits_data = true,
+		.has_swap = true,
+		.fifosize = 1,
+	}
+};
+
+static struct stm32_usart_info __maybe_unused stm32h7_info = {
+	.ofs = {
+		.cr1	= 0x00,
+		.cr2	= 0x04,
+		.cr3	= 0x08,
+		.brr	= 0x0c,
+		.gtpr	= 0x10,
+		.rtor	= 0x14,
+		.rqr	= 0x18,
+		.isr	= 0x1c,
+		.icr	= 0x20,
+		.rdr	= 0x24,
+		.tdr	= 0x28,
+	},
+	.cfg = {
+		.uart_enable_bit = 0,
+		.has_7bits_data = true,
+		.has_swap = true,
+		.has_wakeup = true,
+		.has_fifo = true,
+		.fifosize = 16,
+	}
+};
+
+static void stm32_usart_stop_tx(struct uart_port *port);
+static void stm32_usart_transmit_chars(struct uart_port *port);
+static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch);
+
+static inline struct stm32_port *to_stm32_port(struct uart_port *port)
+{
+	return container_of(port, struct stm32_port, port);
+}
+
+static void stm32_usart_set_bits(struct uart_port *port, u32 reg, u32 bits)
+{
+	u32 val;
+
+	val = readl_relaxed(port->membase + reg);
+	val |= bits;
+	writel_relaxed(val, port->membase + reg);
+}
+
+static void stm32_usart_clr_bits(struct uart_port *port, u32 reg, u32 bits)
+{
+	u32 val;
+
+	val = readl_relaxed(port->membase + reg);
+	val &= ~bits;
+	writel_relaxed(val, port->membase + reg);
+}
+
+static unsigned int stm32_usart_tx_empty(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static void stm32_usart_rs485_rts_enable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	if (stm32_port->hw_flow_control ||
+	    !(rs485conf->flags & SER_RS485_ENABLED))
+		return;
+
+	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl | TIOCM_RTS);
+	} else {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl & ~TIOCM_RTS);
+	}
+}
+
+static void stm32_usart_rs485_rts_disable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	if (stm32_port->hw_flow_control ||
+	    !(rs485conf->flags & SER_RS485_ENABLED))
+		return;
+
+	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl & ~TIOCM_RTS);
+	} else {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl | TIOCM_RTS);
+	}
+}
+
+static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
+					 u32 delay_DDE, u32 baud)
+{
+	u32 rs485_deat_dedt;
+	u32 rs485_deat_dedt_max = (USART_CR1_DEAT_MASK >> USART_CR1_DEAT_SHIFT);
+	bool over8;
+
+	*cr3 |= USART_CR3_DEM;
+	over8 = *cr1 & USART_CR1_OVER8;
+
+	*cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);
+
+	if (over8)
+		rs485_deat_dedt = delay_ADE * baud * 8;
+	else
+		rs485_deat_dedt = delay_ADE * baud * 16;
+
+	rs485_deat_dedt = DIV_ROUND_CLOSEST(rs485_deat_dedt, 1000);
+	rs485_deat_dedt = rs485_deat_dedt > rs485_deat_dedt_max ?
+			  rs485_deat_dedt_max : rs485_deat_dedt;
+	rs485_deat_dedt = (rs485_deat_dedt << USART_CR1_DEAT_SHIFT) &
+			   USART_CR1_DEAT_MASK;
+	*cr1 |= rs485_deat_dedt;
+
+	if (over8)
+		rs485_deat_dedt = delay_DDE * baud * 8;
+	else
+		rs485_deat_dedt = delay_DDE * baud * 16;
+
+	rs485_deat_dedt = DIV_ROUND_CLOSEST(rs485_deat_dedt, 1000);
+	rs485_deat_dedt = rs485_deat_dedt > rs485_deat_dedt_max ?
+			  rs485_deat_dedt_max : rs485_deat_dedt;
+	rs485_deat_dedt = (rs485_deat_dedt << USART_CR1_DEDT_SHIFT) &
+			   USART_CR1_DEDT_MASK;
+	*cr1 |= rs485_deat_dedt;
+}
+
+static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *termios,
+				    struct serial_rs485 *rs485conf)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	const struct stm32_usart_config *cfg = &stm32_port->info->cfg;
+	u32 usartdiv, baud, cr1, cr3;
+	bool over8;
+
+	stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+
+	if (rs485conf->flags & SER_RS485_ENABLED) {
+		cr1 = readl_relaxed(port->membase + ofs->cr1);
+		cr3 = readl_relaxed(port->membase + ofs->cr3);
+		usartdiv = readl_relaxed(port->membase + ofs->brr);
+		usartdiv = usartdiv & GENMASK(15, 0);
+		over8 = cr1 & USART_CR1_OVER8;
+
+		if (over8)
+			usartdiv = usartdiv | (usartdiv & GENMASK(4, 0))
+				   << USART_BRR_04_R_SHIFT;
+
+		baud = DIV_ROUND_CLOSEST(port->uartclk, usartdiv);
+		stm32_usart_config_reg_rs485(&cr1, &cr3,
+					     rs485conf->delay_rts_before_send,
+					     rs485conf->delay_rts_after_send,
+					     baud);
+
+		if (rs485conf->flags & SER_RS485_RTS_ON_SEND)
+			cr3 &= ~USART_CR3_DEP;
+		else
+			cr3 |= USART_CR3_DEP;
+
+		writel_relaxed(cr3, port->membase + ofs->cr3);
+		writel_relaxed(cr1, port->membase + ofs->cr1);
+
+		rs485conf->flags |= SER_RS485_RX_DURING_TX;
+	} else {
+		stm32_usart_clr_bits(port, ofs->cr3,
+				     USART_CR3_DEM | USART_CR3_DEP);
+		stm32_usart_clr_bits(port, ofs->cr1,
+				     USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);
+	}
+
+	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+
+	/* Adjust RTS polarity in case it's driven in software */
+	if (stm32_usart_tx_empty(port))
+		stm32_usart_rs485_rts_disable(port);
+	else
+		stm32_usart_rs485_rts_enable(port);
+
+	return 0;
+}
+
+static int stm32_usart_init_rs485(struct uart_port *port,
+				  struct platform_device *pdev)
+{
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	rs485conf->flags = 0;
+	rs485conf->delay_rts_before_send = 0;
+	rs485conf->delay_rts_after_send = 0;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	return uart_get_rs485_mode(port);
+}
+
+static bool stm32_usart_rx_dma_started(struct stm32_port *stm32_port)
+{
+	return stm32_port->rx_ch ? stm32_port->rx_dma_busy : false;
+}
+
+static void stm32_usart_rx_dma_terminate(struct stm32_port *stm32_port)
+{
+	dmaengine_terminate_async(stm32_port->rx_ch);
+	stm32_port->rx_dma_busy = false;
+}
+
+static int stm32_usart_dma_pause_resume(struct stm32_port *stm32_port,
+					struct dma_chan *chan,
+					enum dma_status expected_status,
+					int dmaengine_pause_or_resume(struct dma_chan *),
+					bool stm32_usart_xx_dma_started(struct stm32_port *),
+					void stm32_usart_xx_dma_terminate(struct stm32_port *))
+{
+	struct uart_port *port = &stm32_port->port;
+	enum dma_status dma_status;
+	int ret;
+
+	if (!stm32_usart_xx_dma_started(stm32_port))
+		return -EPERM;
+
+	dma_status = dmaengine_tx_status(chan, chan->cookie, NULL);
+	if (dma_status != expected_status)
+		return -EAGAIN;
+
+	ret = dmaengine_pause_or_resume(chan);
+	if (ret) {
+		dev_err(port->dev, "DMA failed with error code: %d\n", ret);
+		stm32_usart_xx_dma_terminate(stm32_port);
+	}
+	return ret;
+}
+
+static int stm32_usart_rx_dma_pause(struct stm32_port *stm32_port)
+{
+	return stm32_usart_dma_pause_resume(stm32_port, stm32_port->rx_ch,
+					    DMA_IN_PROGRESS, dmaengine_pause,
+					    stm32_usart_rx_dma_started,
+					    stm32_usart_rx_dma_terminate);
+}
+
+static int stm32_usart_rx_dma_resume(struct stm32_port *stm32_port)
+{
+	return stm32_usart_dma_pause_resume(stm32_port, stm32_port->rx_ch,
+					    DMA_PAUSED, dmaengine_resume,
+					    stm32_usart_rx_dma_started,
+					    stm32_usart_rx_dma_terminate);
+}
+
+/* Return true when data is pending (in pio mode), and false when no data is pending. */
+static bool stm32_usart_pending_rx_pio(struct uart_port *port, u32 *sr)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	*sr = readl_relaxed(port->membase + ofs->isr);
+	/* Get pending characters in RDR or FIFO */
+	if (*sr & USART_SR_RXNE) {
+		/* Get all pending characters from the RDR or the FIFO when using interrupts */
+		if (!stm32_usart_rx_dma_started(stm32_port))
+			return true;
+
+		/* Handle only RX data errors when using DMA */
+		if (*sr & USART_SR_ERR_MASK)
+			return true;
+	}
+
+	return false;
+}
+
+static u8 stm32_usart_get_char_pio(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	unsigned long c;
+
+	c = readl_relaxed(port->membase + ofs->rdr);
+	/* Apply RDR data mask */
+	c &= stm32_port->rdr_mask;
+
+	return c;
+}
+
+static unsigned int stm32_usart_receive_chars_pio(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	unsigned int size = 0;
+	u32 sr;
+	u8 c, flag;
+
+	while (stm32_usart_pending_rx_pio(port, &sr)) {
+		sr |= USART_SR_DUMMY_RX;
+		flag = TTY_NORMAL;
+
+		/*
+		 * Status bits has to be cleared before reading the RDR:
+		 * In FIFO mode, reading the RDR will pop the next data
+		 * (if any) along with its status bits into the SR.
+		 * Not doing so leads to misalignement between RDR and SR,
+		 * and clear status bits of the next rx data.
+		 *
+		 * Clear errors flags for stm32f7 and stm32h7 compatible
+		 * devices. On stm32f4 compatible devices, the error bit is
+		 * cleared by the sequence [read SR - read DR].
+		 */
+		if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG)
+			writel_relaxed(sr & USART_SR_ERR_MASK,
+				       port->membase + ofs->icr);
+
+		c = stm32_usart_get_char_pio(port);
+		port->icount.rx++;
+		size++;
+		if (sr & USART_SR_ERR_MASK) {
+			if (sr & USART_SR_ORE) {
+				port->icount.overrun++;
+			} else if (sr & USART_SR_PE) {
+				port->icount.parity++;
+			} else if (sr & USART_SR_FE) {
+				/* Break detection if character is null */
+				if (!c) {
+					port->icount.brk++;
+					if (uart_handle_break(port))
+						continue;
+				} else {
+					port->icount.frame++;
+				}
+			}
+
+			sr &= port->read_status_mask;
+
+			if (sr & USART_SR_PE) {
+				flag = TTY_PARITY;
+			} else if (sr & USART_SR_FE) {
+				if (!c)
+					flag = TTY_BREAK;
+				else
+					flag = TTY_FRAME;
+			}
+		}
+
+		if (uart_prepare_sysrq_char(port, c))
+			continue;
+		uart_insert_char(port, sr, USART_SR_ORE, c, flag);
+	}
+
+	return size;
+}
+
+static void stm32_usart_push_buffer_dma(struct uart_port *port, unsigned int dma_size)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct tty_port *ttyport = &stm32_port->port.state->port;
+	unsigned char *dma_start;
+	int dma_count, i;
+
+	dma_start = stm32_port->rx_buf + (RX_BUF_L - stm32_port->last_res);
+
+	/*
+	 * Apply rdr_mask on buffer in order to mask parity bit.
+	 * This loop is useless in cs8 mode because DMA copies only
+	 * 8 bits and already ignores parity bit.
+	 */
+	if (!(stm32_port->rdr_mask == (BIT(8) - 1)))
+		for (i = 0; i < dma_size; i++)
+			*(dma_start + i) &= stm32_port->rdr_mask;
+
+	dma_count = tty_insert_flip_string(ttyport, dma_start, dma_size);
+	port->icount.rx += dma_count;
+	if (dma_count != dma_size)
+		port->icount.buf_overrun++;
+	stm32_port->last_res -= dma_count;
+	if (stm32_port->last_res == 0)
+		stm32_port->last_res = RX_BUF_L;
+}
+
+static unsigned int stm32_usart_receive_chars_dma(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	unsigned int dma_size, size = 0;
+
+	/* DMA buffer is configured in cyclic mode and handles the rollback of the buffer. */
+	if (stm32_port->rx_dma_state.residue > stm32_port->last_res) {
+		/* Conditional first part: from last_res to end of DMA buffer */
+		dma_size = stm32_port->last_res;
+		stm32_usart_push_buffer_dma(port, dma_size);
+		size = dma_size;
+	}
+
+	dma_size = stm32_port->last_res - stm32_port->rx_dma_state.residue;
+	stm32_usart_push_buffer_dma(port, dma_size);
+	size += dma_size;
+
+	return size;
+}
+
+static unsigned int stm32_usart_receive_chars(struct uart_port *port, bool force_dma_flush)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	enum dma_status rx_dma_status;
+	u32 sr;
+	unsigned int size = 0;
+
+	if (stm32_usart_rx_dma_started(stm32_port) || force_dma_flush) {
+		rx_dma_status = dmaengine_tx_status(stm32_port->rx_ch,
+						    stm32_port->rx_ch->cookie,
+						    &stm32_port->rx_dma_state);
+		if (rx_dma_status == DMA_IN_PROGRESS ||
+		    rx_dma_status == DMA_PAUSED) {
+			/* Empty DMA buffer */
+			size = stm32_usart_receive_chars_dma(port);
+			sr = readl_relaxed(port->membase + ofs->isr);
+			if (sr & USART_SR_ERR_MASK) {
+				/* Disable DMA request line */
+				stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+
+				/* Switch to PIO mode to handle the errors */
+				size += stm32_usart_receive_chars_pio(port);
+
+				/* Switch back to DMA mode */
+				stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAR);
+			}
+		} else {
+			/* Disable RX DMA */
+			stm32_usart_rx_dma_terminate(stm32_port);
+			/* Fall back to interrupt mode */
+			dev_dbg(port->dev, "DMA error, fallback to irq mode\n");
+			size = stm32_usart_receive_chars_pio(port);
+		}
+	} else {
+		size = stm32_usart_receive_chars_pio(port);
+	}
+
+	return size;
+}
+
+static void stm32_usart_rx_dma_complete(void *arg)
+{
+	struct uart_port *port = arg;
+	struct tty_port *tport = &port->state->port;
+	unsigned int size;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	size = stm32_usart_receive_chars(port, false);
+	uart_unlock_and_check_sysrq_irqrestore(port, flags);
+	if (size)
+		tty_flip_buffer_push(tport);
+}
+
+static int stm32_usart_rx_dma_start_or_resume(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct dma_async_tx_descriptor *desc;
+	enum dma_status rx_dma_status;
+	int ret;
+
+	if (stm32_port->throttled)
+		return 0;
+
+	if (stm32_port->rx_dma_busy) {
+		rx_dma_status = dmaengine_tx_status(stm32_port->rx_ch,
+						    stm32_port->rx_ch->cookie,
+						    NULL);
+		if (rx_dma_status == DMA_IN_PROGRESS)
+			return 0;
+
+		if (rx_dma_status == DMA_PAUSED && !stm32_usart_rx_dma_resume(stm32_port))
+			return 0;
+
+		dev_err(port->dev, "DMA failed : status error.\n");
+		stm32_usart_rx_dma_terminate(stm32_port);
+	}
+
+	stm32_port->rx_dma_busy = true;
+
+	stm32_port->last_res = RX_BUF_L;
+	/* Prepare a DMA cyclic transaction */
+	desc = dmaengine_prep_dma_cyclic(stm32_port->rx_ch,
+					 stm32_port->rx_dma_buf,
+					 RX_BUF_L, RX_BUF_P,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(port->dev, "rx dma prep cyclic failed\n");
+		stm32_port->rx_dma_busy = false;
+		return -ENODEV;
+	}
+
+	desc->callback = stm32_usart_rx_dma_complete;
+	desc->callback_param = port;
+
+	/* Push current DMA transaction in the pending queue */
+	ret = dma_submit_error(dmaengine_submit(desc));
+	if (ret) {
+		dmaengine_terminate_sync(stm32_port->rx_ch);
+		stm32_port->rx_dma_busy = false;
+		return ret;
+	}
+
+	/* Issue pending DMA requests */
+	dma_async_issue_pending(stm32_port->rx_ch);
+
+	return 0;
+}
+
+static void stm32_usart_tx_dma_terminate(struct stm32_port *stm32_port)
+{
+	dmaengine_terminate_async(stm32_port->tx_ch);
+	stm32_port->tx_dma_busy = false;
+}
+
+static bool stm32_usart_tx_dma_started(struct stm32_port *stm32_port)
+{
+	/*
+	 * We cannot use the function "dmaengine_tx_status" to know the
+	 * status of DMA. This function does not show if the "dma complete"
+	 * callback of the DMA transaction has been called. So we prefer
+	 * to use "tx_dma_busy" flag to prevent dual DMA transaction at the
+	 * same time.
+	 */
+	return stm32_port->tx_dma_busy;
+}
+
+static int stm32_usart_tx_dma_pause(struct stm32_port *stm32_port)
+{
+	return stm32_usart_dma_pause_resume(stm32_port, stm32_port->tx_ch,
+					    DMA_IN_PROGRESS, dmaengine_pause,
+					    stm32_usart_tx_dma_started,
+					    stm32_usart_tx_dma_terminate);
+}
+
+static int stm32_usart_tx_dma_resume(struct stm32_port *stm32_port)
+{
+	return stm32_usart_dma_pause_resume(stm32_port, stm32_port->tx_ch,
+					    DMA_PAUSED, dmaengine_resume,
+					    stm32_usart_tx_dma_started,
+					    stm32_usart_tx_dma_terminate);
+}
+
+static void stm32_usart_tx_dma_complete(void *arg)
+{
+	struct uart_port *port = arg;
+	struct stm32_port *stm32port = to_stm32_port(port);
+	unsigned long flags;
+
+	stm32_usart_tx_dma_terminate(stm32port);
+
+	/* Let's see if we have pending data to send */
+	spin_lock_irqsave(&port->lock, flags);
+	stm32_usart_transmit_chars(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	/*
+	 * Enables TX FIFO threashold irq when FIFO is enabled,
+	 * or TX empty irq when FIFO is disabled
+	 */
+	if (stm32_port->fifoen && stm32_port->txftcfg >= 0)
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_TXFTIE);
+	else
+		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
+}
+
+static void stm32_usart_tc_interrupt_enable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TCIE);
+}
+
+static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (stm32_port->fifoen && stm32_port->txftcfg >= 0)
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_TXFTIE);
+	else
+		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
+}
+
+static void stm32_usart_tc_interrupt_disable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TCIE);
+}
+
+static void stm32_usart_transmit_chars_pio(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	struct circ_buf *xmit = &port->state->xmit;
+
+	while (!uart_circ_empty(xmit)) {
+		/* Check that TDR is empty before filling FIFO */
+		if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE))
+			break;
+		writel_relaxed(xmit->buf[xmit->tail], port->membase + ofs->tdr);
+		uart_xmit_advance(port, 1);
+	}
+
+	/* rely on TXE irq (mask or unmask) for sending remaining data */
+	if (uart_circ_empty(xmit))
+		stm32_usart_tx_interrupt_disable(port);
+	else
+		stm32_usart_tx_interrupt_enable(port);
+}
+
+static void stm32_usart_transmit_chars_dma(struct uart_port *port)
+{
+	struct stm32_port *stm32port = to_stm32_port(port);
+	struct circ_buf *xmit = &port->state->xmit;
+	struct dma_async_tx_descriptor *desc = NULL;
+	unsigned int count;
+	int ret;
+
+	if (stm32_usart_tx_dma_started(stm32port)) {
+		ret = stm32_usart_tx_dma_resume(stm32port);
+		if (ret < 0 && ret != -EAGAIN)
+			goto fallback_err;
+		return;
+	}
+
+	count = uart_circ_chars_pending(xmit);
+
+	if (count > TX_BUF_L)
+		count = TX_BUF_L;
+
+	if (xmit->tail < xmit->head) {
+		memcpy(&stm32port->tx_buf[0], &xmit->buf[xmit->tail], count);
+	} else {
+		size_t one = UART_XMIT_SIZE - xmit->tail;
+		size_t two;
+
+		if (one > count)
+			one = count;
+		two = count - one;
+
+		memcpy(&stm32port->tx_buf[0], &xmit->buf[xmit->tail], one);
+		if (two)
+			memcpy(&stm32port->tx_buf[one], &xmit->buf[0], two);
+	}
+
+	desc = dmaengine_prep_slave_single(stm32port->tx_ch,
+					   stm32port->tx_dma_buf,
+					   count,
+					   DMA_MEM_TO_DEV,
+					   DMA_PREP_INTERRUPT);
+
+	if (!desc)
+		goto fallback_err;
+
+	/*
+	 * Set "tx_dma_busy" flag. This flag will be released when
+	 * dmaengine_terminate_async will be called. This flag helps
+	 * transmit_chars_dma not to start another DMA transaction
+	 * if the callback of the previous is not yet called.
+	 */
+	stm32port->tx_dma_busy = true;
+
+	desc->callback = stm32_usart_tx_dma_complete;
+	desc->callback_param = port;
+
+	/* Push current DMA TX transaction in the pending queue */
+	/* DMA no yet started, safe to free resources */
+	ret = dma_submit_error(dmaengine_submit(desc));
+	if (ret) {
+		dev_err(port->dev, "DMA failed with error code: %d\n", ret);
+		stm32_usart_tx_dma_terminate(stm32port);
+		goto fallback_err;
+	}
+
+	/* Issue pending DMA TX requests */
+	dma_async_issue_pending(stm32port->tx_ch);
+
+	uart_xmit_advance(port, count);
+
+	return;
+
+fallback_err:
+	stm32_usart_transmit_chars_pio(port);
+}
+
+static void stm32_usart_transmit_chars(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	struct circ_buf *xmit = &port->state->xmit;
+	u32 isr;
+	int ret;
+
+	if (!stm32_port->hw_flow_control &&
+	    port->rs485.flags & SER_RS485_ENABLED &&
+	    (port->x_char ||
+	     !(uart_circ_empty(xmit) || uart_tx_stopped(port)))) {
+		stm32_usart_tc_interrupt_disable(port);
+		stm32_usart_rs485_rts_enable(port);
+	}
+
+	if (port->x_char) {
+		/* dma terminate may have been called in case of dma pause failure */
+		stm32_usart_tx_dma_pause(stm32_port);
+
+		/* Check that TDR is empty before filling FIFO */
+		ret =
+		readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
+						  isr,
+						  (isr & USART_SR_TXE),
+						  10, 1000);
+		if (ret)
+			dev_warn(port->dev, "1 character may be erased\n");
+
+		writel_relaxed(port->x_char, port->membase + ofs->tdr);
+		port->x_char = 0;
+		port->icount.tx++;
+
+		/* dma terminate may have been called in case of dma resume failure */
+		stm32_usart_tx_dma_resume(stm32_port);
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		stm32_usart_tx_interrupt_disable(port);
+		return;
+	}
+
+	if (ofs->icr == UNDEF_REG)
+		stm32_usart_clr_bits(port, ofs->isr, USART_SR_TC);
+	else
+		writel_relaxed(USART_ICR_TCCF, port->membase + ofs->icr);
+
+	if (stm32_port->tx_ch)
+		stm32_usart_transmit_chars_dma(port);
+	else
+		stm32_usart_transmit_chars_pio(port);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit)) {
+		stm32_usart_tx_interrupt_disable(port);
+		if (!stm32_port->hw_flow_control &&
+		    port->rs485.flags & SER_RS485_ENABLED) {
+			stm32_usart_tc_interrupt_enable(port);
+		}
+	}
+}
+
+static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	struct tty_port *tport = &port->state->port;
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	u32 sr;
+	unsigned int size;
+
+	sr = readl_relaxed(port->membase + ofs->isr);
+
+	if (!stm32_port->hw_flow_control &&
+	    port->rs485.flags & SER_RS485_ENABLED &&
+	    (sr & USART_SR_TC)) {
+		stm32_usart_tc_interrupt_disable(port);
+		stm32_usart_rs485_rts_disable(port);
+	}
+
+	if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG)
+		writel_relaxed(USART_ICR_RTOCF,
+			       port->membase + ofs->icr);
+
+	if ((sr & USART_SR_WUF) && ofs->icr != UNDEF_REG) {
+		/* Clear wake up flag and disable wake up interrupt */
+		writel_relaxed(USART_ICR_WUCF,
+			       port->membase + ofs->icr);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE);
+		if (irqd_is_wakeup_set(irq_get_irq_data(port->irq)))
+			pm_wakeup_event(tport->tty->dev, 0);
+	}
+
+	/*
+	 * rx errors in dma mode has to be handled ASAP to avoid overrun as the DMA request
+	 * line has been masked by HW and rx data are stacking in FIFO.
+	 */
+	if (!stm32_port->throttled) {
+		if (((sr & USART_SR_RXNE) && !stm32_usart_rx_dma_started(stm32_port)) ||
+		    ((sr & USART_SR_ERR_MASK) && stm32_usart_rx_dma_started(stm32_port))) {
+			spin_lock(&port->lock);
+			size = stm32_usart_receive_chars(port, false);
+			uart_unlock_and_check_sysrq(port);
+			if (size)
+				tty_flip_buffer_push(tport);
+		}
+	}
+
+	if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) {
+		spin_lock(&port->lock);
+		stm32_usart_transmit_chars(port);
+		spin_unlock(&port->lock);
+	}
+
+	/* Receiver timeout irq for DMA RX */
+	if (stm32_usart_rx_dma_started(stm32_port) && !stm32_port->throttled) {
+		spin_lock(&port->lock);
+		size = stm32_usart_receive_chars(port, false);
+		uart_unlock_and_check_sysrq(port);
+		if (size)
+			tty_flip_buffer_push(tport);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_RTSE);
+	else
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_RTSE);
+
+	mctrl_gpio_set(stm32_port->gpios, mctrl);
+}
+
+static unsigned int stm32_usart_get_mctrl(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	unsigned int ret;
+
+	/* This routine is used to get signals of: DCD, DSR, RI, and CTS */
+	ret = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+
+	return mctrl_gpio_get(stm32_port->gpios, &ret);
+}
+
+static void stm32_usart_enable_ms(struct uart_port *port)
+{
+	mctrl_gpio_enable_ms(to_stm32_port(port)->gpios);
+}
+
+static void stm32_usart_disable_ms(struct uart_port *port)
+{
+	mctrl_gpio_disable_ms(to_stm32_port(port)->gpios);
+}
+
+/* Transmit stop */
+static void stm32_usart_stop_tx(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+
+	stm32_usart_tx_interrupt_disable(port);
+
+	/* dma terminate may have been called in case of dma pause failure */
+	stm32_usart_tx_dma_pause(stm32_port);
+
+	stm32_usart_rs485_rts_disable(port);
+}
+
+/* There are probably characters waiting to be transmitted. */
+static void stm32_usart_start_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (uart_circ_empty(xmit) && !port->x_char) {
+		stm32_usart_rs485_rts_disable(port);
+		return;
+	}
+
+	stm32_usart_rs485_rts_enable(port);
+
+	stm32_usart_transmit_chars(port);
+}
+
+/* Flush the transmit buffer. */
+static void stm32_usart_flush_buffer(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+
+	if (stm32_port->tx_ch)
+		stm32_usart_tx_dma_terminate(stm32_port);
+}
+
+/* Throttle the remote when input buffer is about to overflow. */
+static void stm32_usart_throttle(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Pause DMA transfer, so the RX data gets queued into the FIFO.
+	 * Hardware flow control is triggered when RX FIFO is full.
+	 */
+	stm32_usart_rx_dma_pause(stm32_port);
+
+	stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	if (stm32_port->cr3_irq)
+		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+
+	stm32_port->throttled = true;
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Unthrottle the remote, the input buffer can now accept data. */
+static void stm32_usart_unthrottle(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	stm32_usart_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	if (stm32_port->cr3_irq)
+		stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
+
+	stm32_port->throttled = false;
+
+	/*
+	 * Switch back to DMA mode (resume DMA).
+	 * Hardware flow control is stopped when FIFO is not full any more.
+	 */
+	if (stm32_port->rx_ch)
+		stm32_usart_rx_dma_start_or_resume(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Receive stop */
+static void stm32_usart_stop_rx(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	/* Disable DMA request line. */
+	stm32_usart_rx_dma_pause(stm32_port);
+
+	stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	if (stm32_port->cr3_irq)
+		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+}
+
+/* Handle breaks - ignored by us */
+static void stm32_usart_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int stm32_usart_startup(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	const struct stm32_usart_config *cfg = &stm32_port->info->cfg;
+	const char *name = to_platform_device(port->dev)->name;
+	u32 val;
+	int ret;
+
+	ret = request_irq(port->irq, stm32_usart_interrupt,
+			  IRQF_NO_SUSPEND, name, port);
+	if (ret)
+		return ret;
+
+	if (stm32_port->swap) {
+		val = readl_relaxed(port->membase + ofs->cr2);
+		val |= USART_CR2_SWAP;
+		writel_relaxed(val, port->membase + ofs->cr2);
+	}
+
+	/* RX FIFO Flush */
+	if (ofs->rqr != UNDEF_REG)
+		writel_relaxed(USART_RQR_RXFRQ, port->membase + ofs->rqr);
+
+	if (stm32_port->rx_ch) {
+		ret = stm32_usart_rx_dma_start_or_resume(port);
+		if (ret) {
+			free_irq(port->irq, port);
+			return ret;
+		}
+	}
+
+	/* RX enabling */
+	val = stm32_port->cr1_irq | USART_CR1_RE | BIT(cfg->uart_enable_bit);
+	stm32_usart_set_bits(port, ofs->cr1, val);
+
+	return 0;
+}
+
+static void stm32_usart_shutdown(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	const struct stm32_usart_config *cfg = &stm32_port->info->cfg;
+	u32 val, isr;
+	int ret;
+
+	if (stm32_usart_tx_dma_started(stm32_port))
+		stm32_usart_tx_dma_terminate(stm32_port);
+
+	if (stm32_port->tx_ch)
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+
+	/* Disable modem control interrupts */
+	stm32_usart_disable_ms(port);
+
+	val = USART_CR1_TXEIE | USART_CR1_TE;
+	val |= stm32_port->cr1_irq | USART_CR1_RE;
+	val |= BIT(cfg->uart_enable_bit);
+	if (stm32_port->fifoen)
+		val |= USART_CR1_FIFOEN;
+
+	ret = readl_relaxed_poll_timeout(port->membase + ofs->isr,
+					 isr, (isr & USART_SR_TC),
+					 10, 100000);
+
+	/* Send the TC error message only when ISR_TC is not set */
+	if (ret)
+		dev_err(port->dev, "Transmission is not complete\n");
+
+	/* Disable RX DMA. */
+	if (stm32_port->rx_ch) {
+		stm32_usart_rx_dma_terminate(stm32_port);
+		dmaengine_synchronize(stm32_port->rx_ch);
+	}
+
+	/* flush RX & TX FIFO */
+	if (ofs->rqr != UNDEF_REG)
+		writel_relaxed(USART_RQR_TXFRQ | USART_RQR_RXFRQ,
+			       port->membase + ofs->rqr);
+
+	stm32_usart_clr_bits(port, ofs->cr1, val);
+
+	free_irq(port->irq, port);
+}
+
+static void stm32_usart_set_termios(struct uart_port *port,
+				    struct ktermios *termios,
+				    const struct ktermios *old)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	const struct stm32_usart_config *cfg = &stm32_port->info->cfg;
+	struct serial_rs485 *rs485conf = &port->rs485;
+	unsigned int baud, bits;
+	u32 usartdiv, mantissa, fraction, oversampling;
+	tcflag_t cflag = termios->c_cflag;
+	u32 cr1, cr2, cr3, isr;
+	unsigned long flags;
+	int ret;
+
+	if (!stm32_port->hw_flow_control)
+		cflag &= ~CRTSCTS;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 8);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
+						isr,
+						(isr & USART_SR_TC),
+						10, 100000);
+
+	/* Send the TC error message only when ISR_TC is not set. */
+	if (ret)
+		dev_err(port->dev, "Transmission is not complete\n");
+
+	/* Stop serial port and reset value */
+	writel_relaxed(0, port->membase + ofs->cr1);
+
+	/* flush RX & TX FIFO */
+	if (ofs->rqr != UNDEF_REG)
+		writel_relaxed(USART_RQR_TXFRQ | USART_RQR_RXFRQ,
+			       port->membase + ofs->rqr);
+
+	cr1 = USART_CR1_TE | USART_CR1_RE;
+	if (stm32_port->fifoen)
+		cr1 |= USART_CR1_FIFOEN;
+	cr2 = stm32_port->swap ? USART_CR2_SWAP : 0;
+
+	/* Tx and RX FIFO configuration */
+	cr3 = readl_relaxed(port->membase + ofs->cr3);
+	cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTIE;
+	if (stm32_port->fifoen) {
+		if (stm32_port->txftcfg >= 0)
+			cr3 |= stm32_port->txftcfg << USART_CR3_TXFTCFG_SHIFT;
+		if (stm32_port->rxftcfg >= 0)
+			cr3 |= stm32_port->rxftcfg << USART_CR3_RXFTCFG_SHIFT;
+	}
+
+	if (cflag & CSTOPB)
+		cr2 |= USART_CR2_STOP_2B;
+
+	bits = tty_get_char_size(cflag);
+	stm32_port->rdr_mask = (BIT(bits) - 1);
+
+	if (cflag & PARENB) {
+		bits++;
+		cr1 |= USART_CR1_PCE;
+	}
+
+	/*
+	 * Word length configuration:
+	 * CS8 + parity, 9 bits word aka [M1:M0] = 0b01
+	 * CS7 or (CS6 + parity), 7 bits word aka [M1:M0] = 0b10
+	 * CS8 or (CS7 + parity), 8 bits word aka [M1:M0] = 0b00
+	 * M0 and M1 already cleared by cr1 initialization.
+	 */
+	if (bits == 9) {
+		cr1 |= USART_CR1_M0;
+	} else if ((bits == 7) && cfg->has_7bits_data) {
+		cr1 |= USART_CR1_M1;
+	} else if (bits != 8) {
+		dev_dbg(port->dev, "Unsupported data bits config: %u bits\n"
+			, bits);
+		cflag &= ~CSIZE;
+		cflag |= CS8;
+		termios->c_cflag = cflag;
+		bits = 8;
+		if (cflag & PARENB) {
+			bits++;
+			cr1 |= USART_CR1_M0;
+		}
+	}
+
+	if (ofs->rtor != UNDEF_REG && (stm32_port->rx_ch ||
+				       (stm32_port->fifoen &&
+					stm32_port->rxftcfg >= 0))) {
+		if (cflag & CSTOPB)
+			bits = bits + 3; /* 1 start bit + 2 stop bits */
+		else
+			bits = bits + 2; /* 1 start bit + 1 stop bit */
+
+		/* RX timeout irq to occur after last stop bit + bits */
+		stm32_port->cr1_irq = USART_CR1_RTOIE;
+		writel_relaxed(bits, port->membase + ofs->rtor);
+		cr2 |= USART_CR2_RTOEN;
+		/*
+		 * Enable fifo threshold irq in two cases, either when there is no DMA, or when
+		 * wake up over usart, from low power until the DMA gets re-enabled by resume.
+		 */
+		stm32_port->cr3_irq =  USART_CR3_RXFTIE;
+	}
+
+	cr1 |= stm32_port->cr1_irq;
+	cr3 |= stm32_port->cr3_irq;
+
+	if (cflag & PARODD)
+		cr1 |= USART_CR1_PS;
+
+	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
+	if (cflag & CRTSCTS) {
+		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+		cr3 |= USART_CR3_CTSE | USART_CR3_RTSE;
+	}
+
+	usartdiv = DIV_ROUND_CLOSEST(port->uartclk, baud);
+
+	/*
+	 * The USART supports 16 or 8 times oversampling.
+	 * By default we prefer 16 times oversampling, so that the receiver
+	 * has a better tolerance to clock deviations.
+	 * 8 times oversampling is only used to achieve higher speeds.
+	 */
+	if (usartdiv < 16) {
+		oversampling = 8;
+		cr1 |= USART_CR1_OVER8;
+		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_OVER8);
+	} else {
+		oversampling = 16;
+		cr1 &= ~USART_CR1_OVER8;
+		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_OVER8);
+	}
+
+	mantissa = (usartdiv / oversampling) << USART_BRR_DIV_M_SHIFT;
+	fraction = usartdiv % oversampling;
+	writel_relaxed(mantissa | fraction, port->membase + ofs->brr);
+
+	uart_update_timeout(port, cflag, baud);
+
+	port->read_status_mask = USART_SR_ORE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= USART_SR_PE | USART_SR_FE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= USART_SR_FE;
+
+	/* Characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask = USART_SR_PE | USART_SR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= USART_SR_FE;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= USART_SR_ORE;
+	}
+
+	/* Ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= USART_SR_DUMMY_RX;
+
+	if (stm32_port->rx_ch) {
+		/*
+		 * Setup DMA to collect only valid data and enable error irqs.
+		 * This also enables break reception when using DMA.
+		 */
+		cr1 |= USART_CR1_PEIE;
+		cr3 |= USART_CR3_EIE;
+		cr3 |= USART_CR3_DMAR;
+		cr3 |= USART_CR3_DDRE;
+	}
+
+	if (stm32_port->tx_ch)
+		cr3 |= USART_CR3_DMAT;
+
+	if (rs485conf->flags & SER_RS485_ENABLED) {
+		stm32_usart_config_reg_rs485(&cr1, &cr3,
+					     rs485conf->delay_rts_before_send,
+					     rs485conf->delay_rts_after_send,
+					     baud);
+		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+			cr3 &= ~USART_CR3_DEP;
+			rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
+		} else {
+			cr3 |= USART_CR3_DEP;
+			rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+		}
+
+	} else {
+		cr3 &= ~(USART_CR3_DEM | USART_CR3_DEP);
+		cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);
+	}
+
+	/* Configure wake up from low power on start bit detection */
+	if (stm32_port->wakeup_src) {
+		cr3 &= ~USART_CR3_WUS_MASK;
+		cr3 |= USART_CR3_WUS_START_BIT;
+	}
+
+	writel_relaxed(cr3, port->membase + ofs->cr3);
+	writel_relaxed(cr2, port->membase + ofs->cr2);
+	writel_relaxed(cr1, port->membase + ofs->cr1);
+
+	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Handle modem control interrupts */
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		stm32_usart_enable_ms(port);
+	else
+		stm32_usart_disable_ms(port);
+}
+
+static const char *stm32_usart_type(struct uart_port *port)
+{
+	return (port->type == PORT_STM32) ? DRIVER_NAME : NULL;
+}
+
+static void stm32_usart_release_port(struct uart_port *port)
+{
+}
+
+static int stm32_usart_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void stm32_usart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_STM32;
+}
+
+static int
+stm32_usart_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* No user changeable parameters */
+	return -EINVAL;
+}
+
+static void stm32_usart_pm(struct uart_port *port, unsigned int state,
+			   unsigned int oldstate)
+{
+	struct stm32_port *stm32port = container_of(port,
+			struct stm32_port, port);
+	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
+	const struct stm32_usart_config *cfg = &stm32port->info->cfg;
+	unsigned long flags;
+
+	switch (state) {
+	case UART_PM_STATE_ON:
+		pm_runtime_get_sync(port->dev);
+		break;
+	case UART_PM_STATE_OFF:
+		spin_lock_irqsave(&port->lock, flags);
+		stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+		spin_unlock_irqrestore(&port->lock, flags);
+		pm_runtime_put_sync(port->dev);
+		break;
+	}
+}
+
+#if defined(CONFIG_CONSOLE_POLL)
+
+ /* Callbacks for characters polling in debug context (i.e. KGDB). */
+static int stm32_usart_poll_init(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+
+	return clk_prepare_enable(stm32_port->clk);
+}
+
+static int stm32_usart_poll_get_char(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_RXNE))
+		return NO_POLL_CHAR;
+
+	return readl_relaxed(port->membase + ofs->rdr) & stm32_port->rdr_mask;
+}
+
+static void stm32_usart_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+	stm32_usart_console_putchar(port, ch);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops stm32_uart_ops = {
+	.tx_empty	= stm32_usart_tx_empty,
+	.set_mctrl	= stm32_usart_set_mctrl,
+	.get_mctrl	= stm32_usart_get_mctrl,
+	.stop_tx	= stm32_usart_stop_tx,
+	.start_tx	= stm32_usart_start_tx,
+	.throttle	= stm32_usart_throttle,
+	.unthrottle	= stm32_usart_unthrottle,
+	.stop_rx	= stm32_usart_stop_rx,
+	.enable_ms	= stm32_usart_enable_ms,
+	.break_ctl	= stm32_usart_break_ctl,
+	.startup	= stm32_usart_startup,
+	.shutdown	= stm32_usart_shutdown,
+	.flush_buffer	= stm32_usart_flush_buffer,
+	.set_termios	= stm32_usart_set_termios,
+	.pm		= stm32_usart_pm,
+	.type		= stm32_usart_type,
+	.release_port	= stm32_usart_release_port,
+	.request_port	= stm32_usart_request_port,
+	.config_port	= stm32_usart_config_port,
+	.verify_port	= stm32_usart_verify_port,
+#if defined(CONFIG_CONSOLE_POLL)
+	.poll_init      = stm32_usart_poll_init,
+	.poll_get_char	= stm32_usart_poll_get_char,
+	.poll_put_char	= stm32_usart_poll_put_char,
+#endif /* CONFIG_CONSOLE_POLL */
+};
+
+/*
+ * STM32H7 RX & TX FIFO threshold configuration (CR3 RXFTCFG / TXFTCFG)
+ * Note: 1 isn't a valid value in RXFTCFG / TXFTCFG. In this case,
+ * RXNEIE / TXEIE can be used instead of threshold irqs: RXFTIE / TXFTIE.
+ * So, RXFTCFG / TXFTCFG bitfields values are encoded as array index + 1.
+ */
+static const u32 stm32h7_usart_fifo_thresh_cfg[] = { 1, 2, 4, 8, 12, 14, 16 };
+
+static void stm32_usart_get_ftcfg(struct platform_device *pdev, const char *p,
+				  int *ftcfg)
+{
+	u32 bytes, i;
+
+	/* DT option to get RX & TX FIFO threshold (default to 8 bytes) */
+	if (of_property_read_u32(pdev->dev.of_node, p, &bytes))
+		bytes = 8;
+
+	for (i = 0; i < ARRAY_SIZE(stm32h7_usart_fifo_thresh_cfg); i++)
+		if (stm32h7_usart_fifo_thresh_cfg[i] >= bytes)
+			break;
+	if (i >= ARRAY_SIZE(stm32h7_usart_fifo_thresh_cfg))
+		i = ARRAY_SIZE(stm32h7_usart_fifo_thresh_cfg) - 1;
+
+	dev_dbg(&pdev->dev, "%s set to %d bytes\n", p,
+		stm32h7_usart_fifo_thresh_cfg[i]);
+
+	/* Provide FIFO threshold ftcfg (1 is invalid: threshold irq unused) */
+	if (i)
+		*ftcfg = i - 1;
+	else
+		*ftcfg = -EINVAL;
+}
+
+static void stm32_usart_deinit_port(struct stm32_port *stm32port)
+{
+	clk_disable_unprepare(stm32port->clk);
+}
+
+static const struct serial_rs485 stm32_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+		 SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
+static int stm32_usart_init_port(struct stm32_port *stm32port,
+				 struct platform_device *pdev)
+{
+	struct uart_port *port = &stm32port->port;
+	struct resource *res;
+	int ret, irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	port->iotype	= UPIO_MEM;
+	port->flags	= UPF_BOOT_AUTOCONF;
+	port->ops	= &stm32_uart_ops;
+	port->dev	= &pdev->dev;
+	port->fifosize	= stm32port->info->cfg.fifosize;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_STM32_CONSOLE);
+	port->irq = irq;
+	port->rs485_config = stm32_usart_config_rs485;
+	port->rs485_supported = stm32_rs485_supported;
+
+	ret = stm32_usart_init_rs485(port, pdev);
+	if (ret)
+		return ret;
+
+	stm32port->wakeup_src = stm32port->info->cfg.has_wakeup &&
+		of_property_read_bool(pdev->dev.of_node, "wakeup-source");
+
+	stm32port->swap = stm32port->info->cfg.has_swap &&
+		of_property_read_bool(pdev->dev.of_node, "rx-tx-swap");
+
+	stm32port->fifoen = stm32port->info->cfg.has_fifo;
+	if (stm32port->fifoen) {
+		stm32_usart_get_ftcfg(pdev, "rx-threshold",
+				      &stm32port->rxftcfg);
+		stm32_usart_get_ftcfg(pdev, "tx-threshold",
+				      &stm32port->txftcfg);
+	}
+
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+	port->mapbase = res->start;
+
+	spin_lock_init(&port->lock);
+
+	stm32port->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(stm32port->clk))
+		return PTR_ERR(stm32port->clk);
+
+	/* Ensure that clk rate is correct by enabling the clk */
+	ret = clk_prepare_enable(stm32port->clk);
+	if (ret)
+		return ret;
+
+	stm32port->port.uartclk = clk_get_rate(stm32port->clk);
+	if (!stm32port->port.uartclk) {
+		ret = -EINVAL;
+		goto err_clk;
+	}
+
+	stm32port->gpios = mctrl_gpio_init(&stm32port->port, 0);
+	if (IS_ERR(stm32port->gpios)) {
+		ret = PTR_ERR(stm32port->gpios);
+		goto err_clk;
+	}
+
+	/*
+	 * Both CTS/RTS gpios and "st,hw-flow-ctrl" (deprecated) or "uart-has-rtscts"
+	 * properties should not be specified.
+	 */
+	if (stm32port->hw_flow_control) {
+		if (mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_CTS) ||
+		    mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_RTS)) {
+			dev_err(&pdev->dev, "Conflicting RTS/CTS config\n");
+			ret = -EINVAL;
+			goto err_clk;
+		}
+	}
+
+	return ret;
+
+err_clk:
+	clk_disable_unprepare(stm32port->clk);
+
+	return ret;
+}
+
+static struct stm32_port *stm32_usart_of_get_port(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int id;
+
+	if (!np)
+		return NULL;
+
+	id = of_alias_get_id(np, "serial");
+	if (id < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", id);
+		return NULL;
+	}
+
+	if (WARN_ON(id >= STM32_MAX_PORTS))
+		return NULL;
+
+	stm32_ports[id].hw_flow_control =
+		of_property_read_bool (np, "st,hw-flow-ctrl") /*deprecated*/ ||
+		of_property_read_bool (np, "uart-has-rtscts");
+	stm32_ports[id].port.line = id;
+	stm32_ports[id].cr1_irq = USART_CR1_RXNEIE;
+	stm32_ports[id].cr3_irq = 0;
+	stm32_ports[id].last_res = RX_BUF_L;
+	return &stm32_ports[id];
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id stm32_match[] = {
+	{ .compatible = "st,stm32-uart", .data = &stm32f4_info},
+	{ .compatible = "st,stm32f7-uart", .data = &stm32f7_info},
+	{ .compatible = "st,stm32h7-uart", .data = &stm32h7_info},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, stm32_match);
+#endif
+
+static void stm32_usart_of_dma_rx_remove(struct stm32_port *stm32port,
+					 struct platform_device *pdev)
+{
+	if (stm32port->rx_buf)
+		dma_free_coherent(&pdev->dev, RX_BUF_L, stm32port->rx_buf,
+				  stm32port->rx_dma_buf);
+}
+
+static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
+				       struct platform_device *pdev)
+{
+	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
+	struct uart_port *port = &stm32port->port;
+	struct device *dev = &pdev->dev;
+	struct dma_slave_config config;
+	int ret;
+
+	stm32port->rx_buf = dma_alloc_coherent(dev, RX_BUF_L,
+					       &stm32port->rx_dma_buf,
+					       GFP_KERNEL);
+	if (!stm32port->rx_buf)
+		return -ENOMEM;
+
+	/* Configure DMA channel */
+	memset(&config, 0, sizeof(config));
+	config.src_addr = port->mapbase + ofs->rdr;
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+
+	ret = dmaengine_slave_config(stm32port->rx_ch, &config);
+	if (ret < 0) {
+		dev_err(dev, "rx dma channel config failed\n");
+		stm32_usart_of_dma_rx_remove(stm32port, pdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void stm32_usart_of_dma_tx_remove(struct stm32_port *stm32port,
+					 struct platform_device *pdev)
+{
+	if (stm32port->tx_buf)
+		dma_free_coherent(&pdev->dev, TX_BUF_L, stm32port->tx_buf,
+				  stm32port->tx_dma_buf);
+}
+
+static int stm32_usart_of_dma_tx_probe(struct stm32_port *stm32port,
+				       struct platform_device *pdev)
+{
+	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
+	struct uart_port *port = &stm32port->port;
+	struct device *dev = &pdev->dev;
+	struct dma_slave_config config;
+	int ret;
+
+	stm32port->tx_buf = dma_alloc_coherent(dev, TX_BUF_L,
+					       &stm32port->tx_dma_buf,
+					       GFP_KERNEL);
+	if (!stm32port->tx_buf)
+		return -ENOMEM;
+
+	/* Configure DMA channel */
+	memset(&config, 0, sizeof(config));
+	config.dst_addr = port->mapbase + ofs->tdr;
+	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+
+	ret = dmaengine_slave_config(stm32port->tx_ch, &config);
+	if (ret < 0) {
+		dev_err(dev, "tx dma channel config failed\n");
+		stm32_usart_of_dma_tx_remove(stm32port, pdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_usart_serial_probe(struct platform_device *pdev)
+{
+	struct stm32_port *stm32port;
+	int ret;
+
+	stm32port = stm32_usart_of_get_port(pdev);
+	if (!stm32port)
+		return -ENODEV;
+
+	stm32port->info = of_device_get_match_data(&pdev->dev);
+	if (!stm32port->info)
+		return -EINVAL;
+
+	stm32port->rx_ch = dma_request_chan(&pdev->dev, "rx");
+	if (PTR_ERR(stm32port->rx_ch) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	/* Fall back in interrupt mode for any non-deferral error */
+	if (IS_ERR(stm32port->rx_ch))
+		stm32port->rx_ch = NULL;
+
+	stm32port->tx_ch = dma_request_chan(&pdev->dev, "tx");
+	if (PTR_ERR(stm32port->tx_ch) == -EPROBE_DEFER) {
+		ret = -EPROBE_DEFER;
+		goto err_dma_rx;
+	}
+	/* Fall back in interrupt mode for any non-deferral error */
+	if (IS_ERR(stm32port->tx_ch))
+		stm32port->tx_ch = NULL;
+
+	ret = stm32_usart_init_port(stm32port, pdev);
+	if (ret)
+		goto err_dma_tx;
+
+	if (stm32port->wakeup_src) {
+		device_set_wakeup_capable(&pdev->dev, true);
+		ret = dev_pm_set_wake_irq(&pdev->dev, stm32port->port.irq);
+		if (ret)
+			goto err_deinit_port;
+	}
+
+	if (stm32port->rx_ch && stm32_usart_of_dma_rx_probe(stm32port, pdev)) {
+		/* Fall back in interrupt mode */
+		dma_release_channel(stm32port->rx_ch);
+		stm32port->rx_ch = NULL;
+	}
+
+	if (stm32port->tx_ch && stm32_usart_of_dma_tx_probe(stm32port, pdev)) {
+		/* Fall back in interrupt mode */
+		dma_release_channel(stm32port->tx_ch);
+		stm32port->tx_ch = NULL;
+	}
+
+	if (!stm32port->rx_ch)
+		dev_info(&pdev->dev, "interrupt mode for rx (no dma)\n");
+	if (!stm32port->tx_ch)
+		dev_info(&pdev->dev, "interrupt mode for tx (no dma)\n");
+
+	platform_set_drvdata(pdev, &stm32port->port);
+
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
+	if (ret)
+		goto err_port;
+
+	pm_runtime_put_sync(&pdev->dev);
+
+	return 0;
+
+err_port:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+
+	if (stm32port->tx_ch)
+		stm32_usart_of_dma_tx_remove(stm32port, pdev);
+	if (stm32port->rx_ch)
+		stm32_usart_of_dma_rx_remove(stm32port, pdev);
+
+	if (stm32port->wakeup_src)
+		dev_pm_clear_wake_irq(&pdev->dev);
+
+err_deinit_port:
+	if (stm32port->wakeup_src)
+		device_set_wakeup_capable(&pdev->dev, false);
+
+	stm32_usart_deinit_port(stm32port);
+
+err_dma_tx:
+	if (stm32port->tx_ch)
+		dma_release_channel(stm32port->tx_ch);
+
+err_dma_rx:
+	if (stm32port->rx_ch)
+		dma_release_channel(stm32port->rx_ch);
+
+	return ret;
+}
+
+static int stm32_usart_serial_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	u32 cr3;
+
+	pm_runtime_get_sync(&pdev->dev);
+	uart_remove_one_port(&stm32_usart_driver, port);
+
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+
+	stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_PEIE);
+
+	if (stm32_port->tx_ch) {
+		stm32_usart_of_dma_tx_remove(stm32_port, pdev);
+		dma_release_channel(stm32_port->tx_ch);
+	}
+
+	if (stm32_port->rx_ch) {
+		stm32_usart_of_dma_rx_remove(stm32_port, pdev);
+		dma_release_channel(stm32_port->rx_ch);
+	}
+
+	cr3 = readl_relaxed(port->membase + ofs->cr3);
+	cr3 &= ~USART_CR3_EIE;
+	cr3 &= ~USART_CR3_DMAR;
+	cr3 &= ~USART_CR3_DMAT;
+	cr3 &= ~USART_CR3_DDRE;
+	writel_relaxed(cr3, port->membase + ofs->cr3);
+
+	if (stm32_port->wakeup_src) {
+		dev_pm_clear_wake_irq(&pdev->dev);
+		device_init_wakeup(&pdev->dev, false);
+	}
+
+	stm32_usart_deinit_port(stm32_port);
+
+	return 0;
+}
+
+static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	u32 isr;
+	int ret;
+
+	ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, isr,
+						(isr & USART_SR_TXE), 100,
+						STM32_USART_TIMEOUT_USEC);
+	if (ret != 0) {
+		dev_err(port->dev, "Error while sending data in UART TX : %d\n", ret);
+		return;
+	}
+	writel_relaxed(ch, port->membase + ofs->tdr);
+}
+
+#ifdef CONFIG_SERIAL_STM32_CONSOLE
+static void stm32_usart_console_write(struct console *co, const char *s,
+				      unsigned int cnt)
+{
+	struct uart_port *port = &stm32_ports[co->index].port;
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	const struct stm32_usart_config *cfg = &stm32_port->info->cfg;
+	unsigned long flags;
+	u32 old_cr1, new_cr1;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/* Save and disable interrupts, enable the transmitter */
+	old_cr1 = readl_relaxed(port->membase + ofs->cr1);
+	new_cr1 = old_cr1 & ~USART_CR1_IE_MASK;
+	new_cr1 |=  USART_CR1_TE | BIT(cfg->uart_enable_bit);
+	writel_relaxed(new_cr1, port->membase + ofs->cr1);
+
+	uart_console_write(port, s, cnt, stm32_usart_console_putchar);
+
+	/* Restore interrupt state */
+	writel_relaxed(old_cr1, port->membase + ofs->cr1);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int stm32_usart_console_setup(struct console *co, char *options)
+{
+	struct stm32_port *stm32port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= STM32_MAX_PORTS)
+		return -ENODEV;
+
+	stm32port = &stm32_ports[co->index];
+
+	/*
+	 * This driver does not support early console initialization
+	 * (use ARM early printk support instead), so we only expect
+	 * this to be called during the uart port registration when the
+	 * driver gets probed and the port should be mapped at that point.
+	 */
+	if (stm32port->port.mapbase == 0 || !stm32port->port.membase)
+		return -ENXIO;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&stm32port->port, co, baud, parity, bits, flow);
+}
+
+static struct console stm32_console = {
+	.name		= STM32_SERIAL_NAME,
+	.device		= uart_console_device,
+	.write		= stm32_usart_console_write,
+	.setup		= stm32_usart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &stm32_usart_driver,
+};
+
+#define STM32_SERIAL_CONSOLE (&stm32_console)
+
+#else
+#define STM32_SERIAL_CONSOLE NULL
+#endif /* CONFIG_SERIAL_STM32_CONSOLE */
+
+#ifdef CONFIG_SERIAL_EARLYCON
+static void early_stm32_usart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct stm32_usart_info *info = port->private_data;
+
+	while (!(readl_relaxed(port->membase + info->ofs.isr) & USART_SR_TXE))
+		cpu_relax();
+
+	writel_relaxed(ch, port->membase + info->ofs.tdr);
+}
+
+static void early_stm32_serial_write(struct console *console, const char *s, unsigned int count)
+{
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+
+	uart_console_write(port, s, count, early_stm32_usart_console_putchar);
+}
+
+static int __init early_stm32_h7_serial_setup(struct earlycon_device *device, const char *options)
+{
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+	device->port.private_data = &stm32h7_info;
+	device->con->write = early_stm32_serial_write;
+	return 0;
+}
+
+static int __init early_stm32_f7_serial_setup(struct earlycon_device *device, const char *options)
+{
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+	device->port.private_data = &stm32f7_info;
+	device->con->write = early_stm32_serial_write;
+	return 0;
+}
+
+static int __init early_stm32_f4_serial_setup(struct earlycon_device *device, const char *options)
+{
+	if (!(device->port.membase || device->port.iobase))
+		return -ENODEV;
+	device->port.private_data = &stm32f4_info;
+	device->con->write = early_stm32_serial_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(stm32, "st,stm32h7-uart", early_stm32_h7_serial_setup);
+OF_EARLYCON_DECLARE(stm32, "st,stm32f7-uart", early_stm32_f7_serial_setup);
+OF_EARLYCON_DECLARE(stm32, "st,stm32-uart", early_stm32_f4_serial_setup);
+#endif /* CONFIG_SERIAL_EARLYCON */
+
+static struct uart_driver stm32_usart_driver = {
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= STM32_SERIAL_NAME,
+	.major		= 0,
+	.minor		= 0,
+	.nr		= STM32_MAX_PORTS,
+	.cons		= STM32_SERIAL_CONSOLE,
+};
+
+static int __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port,
+						       bool enable)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	struct tty_port *tport = &port->state->port;
+	int ret;
+	unsigned int size = 0;
+	unsigned long flags;
+
+	if (!stm32_port->wakeup_src || !tty_port_initialized(tport))
+		return 0;
+
+	/*
+	 * Enable low-power wake-up and wake-up irq if argument is set to
+	 * "enable", disable low-power wake-up and wake-up irq otherwise
+	 */
+	if (enable) {
+		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_UESM);
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_WUFIE);
+		mctrl_gpio_enable_irq_wake(stm32_port->gpios);
+
+		/*
+		 * When DMA is used for reception, it must be disabled before
+		 * entering low-power mode and re-enabled when exiting from
+		 * low-power mode.
+		 */
+		if (stm32_port->rx_ch) {
+			spin_lock_irqsave(&port->lock, flags);
+			/* Poll data from DMA RX buffer if any */
+			if (!stm32_usart_rx_dma_pause(stm32_port))
+				size += stm32_usart_receive_chars(port, true);
+			stm32_usart_rx_dma_terminate(stm32_port);
+			uart_unlock_and_check_sysrq_irqrestore(port, flags);
+			if (size)
+				tty_flip_buffer_push(tport);
+		}
+
+		/* Poll data from RX FIFO if any */
+		stm32_usart_receive_chars(port, false);
+	} else {
+		if (stm32_port->rx_ch) {
+			ret = stm32_usart_rx_dma_start_or_resume(port);
+			if (ret)
+				return ret;
+		}
+		mctrl_gpio_disable_irq_wake(stm32_port->gpios);
+		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_UESM);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused stm32_usart_serial_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	int ret;
+
+	uart_suspend_port(&stm32_usart_driver, port);
+
+	if (device_may_wakeup(dev) || device_wakeup_path(dev)) {
+		ret = stm32_usart_serial_en_wakeup(port, true);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * When "no_console_suspend" is enabled, keep the pinctrl default state
+	 * and rely on bootloader stage to restore this state upon resume.
+	 * Otherwise, apply the idle or sleep states depending on wakeup
+	 * capabilities.
+	 */
+	if (console_suspend_enabled || !uart_console(port)) {
+		if (device_may_wakeup(dev) || device_wakeup_path(dev))
+			pinctrl_pm_select_idle_state(dev);
+		else
+			pinctrl_pm_select_sleep_state(dev);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused stm32_usart_serial_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	int ret;
+
+	pinctrl_pm_select_default_state(dev);
+
+	if (device_may_wakeup(dev) || device_wakeup_path(dev)) {
+		ret = stm32_usart_serial_en_wakeup(port, false);
+		if (ret)
+			return ret;
+	}
+
+	return uart_resume_port(&stm32_usart_driver, port);
+}
+
+static int __maybe_unused stm32_usart_runtime_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct stm32_port *stm32port = container_of(port,
+			struct stm32_port, port);
+
+	clk_disable_unprepare(stm32port->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_usart_runtime_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct stm32_port *stm32port = container_of(port,
+			struct stm32_port, port);
+
+	return clk_prepare_enable(stm32port->clk);
+}
+
+static const struct dev_pm_ops stm32_serial_pm_ops = {
+	SET_RUNTIME_PM_OPS(stm32_usart_runtime_suspend,
+			   stm32_usart_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(stm32_usart_serial_suspend,
+				stm32_usart_serial_resume)
+};
+
+static struct platform_driver stm32_serial_driver = {
+	.probe		= stm32_usart_serial_probe,
+	.remove		= stm32_usart_serial_remove,
+	.driver	= {
+		.name	= DRIVER_NAME,
+		.pm	= &stm32_serial_pm_ops,
+		.of_match_table = of_match_ptr(stm32_match),
+	},
+};
+
+static int __init stm32_usart_init(void)
+{
+	static char banner[] __initdata = "STM32 USART driver initialized";
+	int ret;
+
+	pr_info("%s\n", banner);
+
+	ret = uart_register_driver(&stm32_usart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&stm32_serial_driver);
+	if (ret)
+		uart_unregister_driver(&stm32_usart_driver);
+
+	return ret;
+}
+
+static void __exit stm32_usart_exit(void)
+{
+	platform_driver_unregister(&stm32_serial_driver);
+	uart_unregister_driver(&stm32_usart_driver);
+}
+
+module_init(stm32_usart_init);
+module_exit(stm32_usart_exit);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_DESCRIPTION("STMicroelectronics STM32 serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
new file mode 100644
index 000000000..f59f831b2
--- /dev/null
+++ b/drivers/tty/serial/stm32-usart.h
@@ -0,0 +1,216 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Copyright (C) STMicroelectronics SA 2017
+ * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ *	     Gerald Baeza <gerald_baeza@yahoo.fr>
+ */
+
+#define DRIVER_NAME "stm32-usart"
+
+struct stm32_usart_offsets {
+	u8 cr1;
+	u8 cr2;
+	u8 cr3;
+	u8 brr;
+	u8 gtpr;
+	u8 rtor;
+	u8 rqr;
+	u8 isr;
+	u8 icr;
+	u8 rdr;
+	u8 tdr;
+};
+
+struct stm32_usart_config {
+	u8 uart_enable_bit; /* USART_CR1_UE */
+	bool has_7bits_data;
+	bool has_swap;
+	bool has_wakeup;
+	bool has_fifo;
+	int fifosize;
+};
+
+struct stm32_usart_info {
+	struct stm32_usart_offsets ofs;
+	struct stm32_usart_config cfg;
+};
+
+#define UNDEF_REG 0xff
+
+/* USART_SR (F4) / USART_ISR (F7) */
+#define USART_SR_PE		BIT(0)
+#define USART_SR_FE		BIT(1)
+#define USART_SR_NE		BIT(2)		/* F7 (NF for F4) */
+#define USART_SR_ORE		BIT(3)
+#define USART_SR_IDLE		BIT(4)
+#define USART_SR_RXNE		BIT(5)
+#define USART_SR_TC		BIT(6)
+#define USART_SR_TXE		BIT(7)
+#define USART_SR_CTSIF		BIT(9)
+#define USART_SR_CTS		BIT(10)		/* F7 */
+#define USART_SR_RTOF		BIT(11)		/* F7 */
+#define USART_SR_EOBF		BIT(12)		/* F7 */
+#define USART_SR_ABRE		BIT(14)		/* F7 */
+#define USART_SR_ABRF		BIT(15)		/* F7 */
+#define USART_SR_BUSY		BIT(16)		/* F7 */
+#define USART_SR_CMF		BIT(17)		/* F7 */
+#define USART_SR_SBKF		BIT(18)		/* F7 */
+#define USART_SR_WUF		BIT(20)		/* H7 */
+#define USART_SR_TEACK		BIT(21)		/* F7 */
+#define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_NE | USART_SR_FE |\
+				 USART_SR_PE)
+/* Dummy bits */
+#define USART_SR_DUMMY_RX	BIT(16)
+
+/* USART_DR */
+#define USART_DR_MASK		GENMASK(8, 0)
+
+/* USART_BRR */
+#define USART_BRR_DIV_F_MASK	GENMASK(3, 0)
+#define USART_BRR_DIV_M_MASK	GENMASK(15, 4)
+#define USART_BRR_DIV_M_SHIFT	4
+#define USART_BRR_04_R_SHIFT	1
+
+/* USART_CR1 */
+#define USART_CR1_SBK		BIT(0)
+#define USART_CR1_RWU		BIT(1)		/* F4 */
+#define USART_CR1_UESM		BIT(1)		/* H7 */
+#define USART_CR1_RE		BIT(2)
+#define USART_CR1_TE		BIT(3)
+#define USART_CR1_IDLEIE	BIT(4)
+#define USART_CR1_RXNEIE	BIT(5)
+#define USART_CR1_TCIE		BIT(6)
+#define USART_CR1_TXEIE		BIT(7)
+#define USART_CR1_PEIE		BIT(8)
+#define USART_CR1_PS		BIT(9)
+#define USART_CR1_PCE		BIT(10)
+#define USART_CR1_WAKE		BIT(11)
+#define USART_CR1_M0		BIT(12)		/* F7 (CR1_M for F4) */
+#define USART_CR1_MME		BIT(13)		/* F7 */
+#define USART_CR1_CMIE		BIT(14)		/* F7 */
+#define USART_CR1_OVER8		BIT(15)
+#define USART_CR1_DEDT_MASK	GENMASK(20, 16)	/* F7 */
+#define USART_CR1_DEAT_MASK	GENMASK(25, 21)	/* F7 */
+#define USART_CR1_RTOIE		BIT(26)		/* F7 */
+#define USART_CR1_EOBIE		BIT(27)		/* F7 */
+#define USART_CR1_M1		BIT(28)		/* F7 */
+#define USART_CR1_IE_MASK	(GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
+#define USART_CR1_FIFOEN	BIT(29)		/* H7 */
+#define USART_CR1_DEAT_SHIFT 21
+#define USART_CR1_DEDT_SHIFT 16
+
+/* USART_CR2 */
+#define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
+#define USART_CR2_ADDM7		BIT(4)		/* F7 */
+#define USART_CR2_LBCL		BIT(8)
+#define USART_CR2_CPHA		BIT(9)
+#define USART_CR2_CPOL		BIT(10)
+#define USART_CR2_CLKEN		BIT(11)
+#define USART_CR2_STOP_2B	BIT(13)
+#define USART_CR2_STOP_MASK	GENMASK(13, 12)
+#define USART_CR2_LINEN		BIT(14)
+#define USART_CR2_SWAP		BIT(15)		/* F7 */
+#define USART_CR2_RXINV		BIT(16)		/* F7 */
+#define USART_CR2_TXINV		BIT(17)		/* F7 */
+#define USART_CR2_DATAINV	BIT(18)		/* F7 */
+#define USART_CR2_MSBFIRST	BIT(19)		/* F7 */
+#define USART_CR2_ABREN		BIT(20)		/* F7 */
+#define USART_CR2_ABRMOD_MASK	GENMASK(22, 21)	/* F7 */
+#define USART_CR2_RTOEN		BIT(23)		/* F7 */
+#define USART_CR2_ADD_F7_MASK	GENMASK(31, 24)	/* F7 */
+
+/* USART_CR3 */
+#define USART_CR3_EIE		BIT(0)
+#define USART_CR3_IREN		BIT(1)
+#define USART_CR3_IRLP		BIT(2)
+#define USART_CR3_HDSEL		BIT(3)
+#define USART_CR3_NACK		BIT(4)
+#define USART_CR3_SCEN		BIT(5)
+#define USART_CR3_DMAR		BIT(6)
+#define USART_CR3_DMAT		BIT(7)
+#define USART_CR3_RTSE		BIT(8)
+#define USART_CR3_CTSE		BIT(9)
+#define USART_CR3_CTSIE		BIT(10)
+#define USART_CR3_ONEBIT	BIT(11)
+#define USART_CR3_OVRDIS	BIT(12)		/* F7 */
+#define USART_CR3_DDRE		BIT(13)		/* F7 */
+#define USART_CR3_DEM		BIT(14)		/* F7 */
+#define USART_CR3_DEP		BIT(15)		/* F7 */
+#define USART_CR3_SCARCNT_MASK	GENMASK(19, 17)	/* F7 */
+#define USART_CR3_WUS_MASK	GENMASK(21, 20)	/* H7 */
+#define USART_CR3_WUS_START_BIT	BIT(21)		/* H7 */
+#define USART_CR3_WUFIE		BIT(22)		/* H7 */
+#define USART_CR3_TXFTIE	BIT(23)		/* H7 */
+#define USART_CR3_TCBGTIE	BIT(24)		/* H7 */
+#define USART_CR3_RXFTCFG_MASK	GENMASK(27, 25)	/* H7 */
+#define USART_CR3_RXFTCFG_SHIFT	25		/* H7 */
+#define USART_CR3_RXFTIE	BIT(28)		/* H7 */
+#define USART_CR3_TXFTCFG_MASK	GENMASK(31, 29)	/* H7 */
+#define USART_CR3_TXFTCFG_SHIFT	29		/* H7 */
+
+/* USART_GTPR */
+#define USART_GTPR_PSC_MASK	GENMASK(7, 0)
+#define USART_GTPR_GT_MASK	GENMASK(15, 8)
+
+/* USART_RTOR */
+#define USART_RTOR_RTO_MASK	GENMASK(23, 0)	/* F7 */
+#define USART_RTOR_BLEN_MASK	GENMASK(31, 24)	/* F7 */
+
+/* USART_RQR */
+#define USART_RQR_ABRRQ		BIT(0)		/* F7 */
+#define USART_RQR_SBKRQ		BIT(1)		/* F7 */
+#define USART_RQR_MMRQ		BIT(2)		/* F7 */
+#define USART_RQR_RXFRQ		BIT(3)		/* F7 */
+#define USART_RQR_TXFRQ		BIT(4)		/* F7 */
+
+/* USART_ICR */
+#define USART_ICR_PECF		BIT(0)		/* F7 */
+#define USART_ICR_FECF		BIT(1)		/* F7 */
+#define USART_ICR_ORECF		BIT(3)		/* F7 */
+#define USART_ICR_IDLECF	BIT(4)		/* F7 */
+#define USART_ICR_TCCF		BIT(6)		/* F7 */
+#define USART_ICR_CTSCF		BIT(9)		/* F7 */
+#define USART_ICR_RTOCF		BIT(11)		/* F7 */
+#define USART_ICR_EOBCF		BIT(12)		/* F7 */
+#define USART_ICR_CMCF		BIT(17)		/* F7 */
+#define USART_ICR_WUCF		BIT(20)		/* H7 */
+
+#define STM32_SERIAL_NAME "ttySTM"
+#define STM32_MAX_PORTS 8
+
+#define RX_BUF_L 4096		 /* dma rx buffer length     */
+#define RX_BUF_P (RX_BUF_L / 2)	 /* dma rx buffer period     */
+#define TX_BUF_L RX_BUF_L	 /* dma tx buffer length     */
+
+#define STM32_USART_TIMEOUT_USEC USEC_PER_SEC /* 1s timeout in µs */
+
+struct stm32_port {
+	struct uart_port port;
+	struct clk *clk;
+	const struct stm32_usart_info *info;
+	struct dma_chan *rx_ch;  /* dma rx channel            */
+	dma_addr_t rx_dma_buf;   /* dma rx buffer bus address */
+	unsigned char *rx_buf;   /* dma rx buffer cpu address */
+	struct dma_chan *tx_ch;  /* dma tx channel            */
+	dma_addr_t tx_dma_buf;   /* dma tx buffer bus address */
+	unsigned char *tx_buf;   /* dma tx buffer cpu address */
+	u32 cr1_irq;		 /* USART_CR1_RXNEIE or RTOIE */
+	u32 cr3_irq;		 /* USART_CR3_RXFTIE */
+	int last_res;
+	bool tx_dma_busy;	 /* dma tx transaction in progress */
+	bool rx_dma_busy;	 /* dma rx transaction in progress */
+	bool throttled;		 /* port throttled            */
+	bool hw_flow_control;
+	bool swap;		 /* swap RX & TX pins */
+	bool fifoen;
+	int rxftcfg;		/* RX FIFO threshold CFG      */
+	int txftcfg;		/* TX FIFO threshold CFG      */
+	bool wakeup_src;
+	int rdr_mask;		/* receive data register mask */
+	struct mctrl_gpios *gpios; /* modem control gpios */
+	struct dma_tx_state rx_dma_state;
+};
+
+static struct stm32_port stm32_ports[STM32_MAX_PORTS];
+static struct uart_driver stm32_usart_driver;
diff --git a/drivers/tty/serial/suncore.c b/drivers/tty/serial/suncore.c
new file mode 100644
index 000000000..2491551c2
--- /dev/null
+++ b/drivers/tty/serial/suncore.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/* suncore.c
+ *
+ * Common SUN serial routines.  Based entirely
+ * upon drivers/sbus/char/sunserial.c which is:
+ *
+ * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
+ *
+ * Adaptation to new UART layer is:
+ *
+ * Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/serial_core.h>
+#include <linux/sunserialcore.h>
+#include <linux/init.h>
+
+#include <asm/prom.h>
+
+
+static int sunserial_current_minor = 64;
+
+int sunserial_register_minors(struct uart_driver *drv, int count)
+{
+	int err = 0;
+
+	drv->minor = sunserial_current_minor;
+	drv->nr += count;
+	/* Register the driver on the first call */
+	if (drv->nr == count)
+		err = uart_register_driver(drv);
+	if (err == 0) {
+		sunserial_current_minor += count;
+		drv->tty_driver->name_base = drv->minor - 64;
+	}
+	return err;
+}
+EXPORT_SYMBOL(sunserial_register_minors);
+
+void sunserial_unregister_minors(struct uart_driver *drv, int count)
+{
+	drv->nr -= count;
+	sunserial_current_minor -= count;
+
+	if (drv->nr == 0)
+		uart_unregister_driver(drv);
+}
+EXPORT_SYMBOL(sunserial_unregister_minors);
+
+int sunserial_console_match(struct console *con, struct device_node *dp,
+			    struct uart_driver *drv, int line, bool ignore_line)
+{
+	if (!con)
+		return 0;
+
+	drv->cons = con;
+
+	if (of_console_device != dp)
+		return 0;
+
+	if (!ignore_line) {
+		int off = 0;
+
+		if (of_console_options &&
+		    *of_console_options == 'b')
+			off = 1;
+
+		if ((line & 1) != off)
+			return 0;
+	}
+
+	if (!console_set_on_cmdline) {
+		con->index = line;
+		add_preferred_console(con->name, line, NULL);
+	}
+	return 1;
+}
+EXPORT_SYMBOL(sunserial_console_match);
+
+void sunserial_console_termios(struct console *con, struct device_node *uart_dp)
+{
+	const char *mode, *s;
+	char mode_prop[] = "ttyX-mode";
+	int baud, bits, stop, cflag;
+	char parity;
+
+	if (of_node_name_eq(uart_dp, "rsc") ||
+	    of_node_name_eq(uart_dp, "rsc-console") ||
+	    of_node_name_eq(uart_dp, "rsc-control")) {
+		mode = of_get_property(uart_dp,
+				       "ssp-console-modes", NULL);
+		if (!mode)
+			mode = "115200,8,n,1,-";
+	} else if (of_node_name_eq(uart_dp, "lom-console")) {
+		mode = "9600,8,n,1,-";
+	} else {
+		struct device_node *dp;
+		char c;
+
+		c = 'a';
+		if (of_console_options)
+			c = *of_console_options;
+
+		mode_prop[3] = c;
+
+		dp = of_find_node_by_path("/options");
+		mode = of_get_property(dp, mode_prop, NULL);
+		if (!mode)
+			mode = "9600,8,n,1,-";
+		of_node_put(dp);
+	}
+
+	cflag = CREAD | HUPCL | CLOCAL;
+
+	s = mode;
+	baud = simple_strtoul(s, NULL, 0);
+	s = strchr(s, ',');
+	bits = simple_strtoul(++s, NULL, 0);
+	s = strchr(s, ',');
+	parity = *(++s);
+	s = strchr(s, ',');
+	stop = simple_strtoul(++s, NULL, 0);
+	s = strchr(s, ',');
+	/* XXX handshake is not handled here. */
+
+	switch (baud) {
+		case 150: cflag |= B150; break;
+		case 300: cflag |= B300; break;
+		case 600: cflag |= B600; break;
+		case 1200: cflag |= B1200; break;
+		case 2400: cflag |= B2400; break;
+		case 4800: cflag |= B4800; break;
+		case 9600: cflag |= B9600; break;
+		case 19200: cflag |= B19200; break;
+		case 38400: cflag |= B38400; break;
+		case 57600: cflag |= B57600; break;
+		case 115200: cflag |= B115200; break;
+		case 230400: cflag |= B230400; break;
+		case 460800: cflag |= B460800; break;
+		default: baud = 9600; cflag |= B9600; break;
+	}
+
+	switch (bits) {
+		case 5: cflag |= CS5; break;
+		case 6: cflag |= CS6; break;
+		case 7: cflag |= CS7; break;
+		case 8: cflag |= CS8; break;
+		default: cflag |= CS8; break;
+	}
+
+	switch (parity) {
+		case 'o': cflag |= (PARENB | PARODD); break;
+		case 'e': cflag |= PARENB; break;
+		case 'n': default: break;
+	}
+
+	switch (stop) {
+		case 2: cflag |= CSTOPB; break;
+		case 1: default: break;
+	}
+
+	con->cflag = cflag;
+}
+
+/* Sun serial MOUSE auto baud rate detection.  */
+static struct mouse_baud_cflag {
+	int baud;
+	unsigned int cflag;
+} mouse_baud_table[] = {
+	{ 1200, B1200 },
+	{ 2400, B2400 },
+	{ 4800, B4800 },
+	{ 9600, B9600 },
+	{ -1, ~0 },
+	{ -1, ~0 },
+};
+
+unsigned int suncore_mouse_baud_cflag_next(unsigned int cflag, int *new_baud)
+{
+	int i;
+
+	for (i = 0; mouse_baud_table[i].baud != -1; i++)
+		if (mouse_baud_table[i].cflag == (cflag & CBAUD))
+			break;
+
+	i += 1;
+	if (mouse_baud_table[i].baud == -1)
+		i = 0;
+
+	*new_baud = mouse_baud_table[i].baud;
+	return mouse_baud_table[i].cflag;
+}
+
+EXPORT_SYMBOL(suncore_mouse_baud_cflag_next);
+
+/* Basically, when the baud rate is wrong the mouse spits out
+ * breaks to us.
+ */
+int suncore_mouse_baud_detection(unsigned char ch, int is_break)
+{
+	static int mouse_got_break = 0;
+	static int ctr = 0;
+
+	if (is_break) {
+		/* Let a few normal bytes go by before we jump the gun
+		 * and say we need to try another baud rate.
+		 */
+		if (mouse_got_break && ctr < 8)
+			return 1;
+
+		/* Ok, we need to try another baud. */
+		ctr = 0;
+		mouse_got_break = 1;
+		return 2;
+	}
+	if (mouse_got_break) {
+		ctr++;
+		if (ch == 0x87) {
+			/* Correct baud rate determined. */
+			mouse_got_break = 0;
+		}
+		return 1;
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(suncore_mouse_baud_detection);
+
+static int __init suncore_init(void)
+{
+	return 0;
+}
+device_initcall(suncore_init);
+
+#if 0 /* ..def MODULE ; never supported as such */
+MODULE_AUTHOR("Eddie C. Dost, David S. Miller");
+MODULE_DESCRIPTION("Sun serial common layer");
+MODULE_LICENSE("GPL");
+#endif
diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
new file mode 100644
index 000000000..c671d674b
--- /dev/null
+++ b/drivers/tty/serial/sunhv.c
@@ -0,0 +1,650 @@
+// SPDX-License-Identifier: GPL-2.0
+/* sunhv.c: Serial driver for SUN4V hypervisor console.
+ *
+ * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <asm/hypervisor.h>
+#include <asm/spitfire.h>
+#include <asm/irq.h>
+#include <asm/setup.h>
+
+#include <linux/serial_core.h>
+#include <linux/sunserialcore.h>
+
+#define CON_BREAK	((long)-1)
+#define CON_HUP		((long)-2)
+
+#define IGNORE_BREAK	0x1
+#define IGNORE_ALL	0x2
+
+static char *con_write_page;
+static char *con_read_page;
+
+static int hung_up = 0;
+
+static void transmit_chars_putchar(struct uart_port *port, struct circ_buf *xmit)
+{
+	while (!uart_circ_empty(xmit)) {
+		long status = sun4v_con_putchar(xmit->buf[xmit->tail]);
+
+		if (status != HV_EOK)
+			break;
+
+		uart_xmit_advance(port, 1);
+	}
+}
+
+static void transmit_chars_write(struct uart_port *port, struct circ_buf *xmit)
+{
+	while (!uart_circ_empty(xmit)) {
+		unsigned long ra = __pa(xmit->buf + xmit->tail);
+		unsigned long len, status, sent;
+
+		len = CIRC_CNT_TO_END(xmit->head, xmit->tail,
+				      UART_XMIT_SIZE);
+		status = sun4v_con_write(ra, len, &sent);
+		if (status != HV_EOK)
+			break;
+		uart_xmit_advance(port, sent);
+	}
+}
+
+static int receive_chars_getchar(struct uart_port *port)
+{
+	int saw_console_brk = 0;
+	int limit = 10000;
+
+	while (limit-- > 0) {
+		long status;
+		long c = sun4v_con_getchar(&status);
+
+		if (status == HV_EWOULDBLOCK)
+			break;
+
+		if (c == CON_BREAK) {
+			if (uart_handle_break(port))
+				continue;
+			saw_console_brk = 1;
+			c = 0;
+		}
+
+		if (c == CON_HUP) {
+			hung_up = 1;
+			uart_handle_dcd_change(port, false);
+		} else if (hung_up) {
+			hung_up = 0;
+			uart_handle_dcd_change(port, true);
+		}
+
+		if (port->state == NULL) {
+			uart_handle_sysrq_char(port, c);
+			continue;
+		}
+
+		port->icount.rx++;
+
+		if (uart_handle_sysrq_char(port, c))
+			continue;
+
+		tty_insert_flip_char(&port->state->port, c, TTY_NORMAL);
+	}
+
+	return saw_console_brk;
+}
+
+static int receive_chars_read(struct uart_port *port)
+{
+	static int saw_console_brk;
+	int limit = 10000;
+
+	while (limit-- > 0) {
+		unsigned long ra = __pa(con_read_page);
+		unsigned long bytes_read, i;
+		long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read);
+
+		if (stat != HV_EOK) {
+			bytes_read = 0;
+
+			if (stat == CON_BREAK) {
+				if (saw_console_brk)
+					sun_do_break();
+
+				if (uart_handle_break(port))
+					continue;
+				saw_console_brk = 1;
+				*con_read_page = 0;
+				bytes_read = 1;
+			} else if (stat == CON_HUP) {
+				hung_up = 1;
+				uart_handle_dcd_change(port, false);
+				continue;
+			} else {
+				/* HV_EWOULDBLOCK, etc.  */
+				break;
+			}
+		}
+
+		if (hung_up) {
+			hung_up = 0;
+			uart_handle_dcd_change(port, true);
+		}
+
+		if (port->sysrq != 0 &&  *con_read_page) {
+			for (i = 0; i < bytes_read; i++)
+				uart_handle_sysrq_char(port, con_read_page[i]);
+			saw_console_brk = 0;
+		}
+
+		if (port->state == NULL)
+			continue;
+
+		port->icount.rx += bytes_read;
+
+		tty_insert_flip_string(&port->state->port, con_read_page,
+				bytes_read);
+	}
+
+	return saw_console_brk;
+}
+
+struct sunhv_ops {
+	void (*transmit_chars)(struct uart_port *port, struct circ_buf *xmit);
+	int (*receive_chars)(struct uart_port *port);
+};
+
+static const struct sunhv_ops bychar_ops = {
+	.transmit_chars = transmit_chars_putchar,
+	.receive_chars = receive_chars_getchar,
+};
+
+static const struct sunhv_ops bywrite_ops = {
+	.transmit_chars = transmit_chars_write,
+	.receive_chars = receive_chars_read,
+};
+
+static const struct sunhv_ops *sunhv_ops = &bychar_ops;
+
+static struct tty_port *receive_chars(struct uart_port *port)
+{
+	struct tty_port *tport = NULL;
+
+	if (port->state != NULL)		/* Unopened serial console */
+		tport = &port->state->port;
+
+	if (sunhv_ops->receive_chars(port))
+		sun_do_break();
+
+	return tport;
+}
+
+static void transmit_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit;
+
+	if (!port->state)
+		return;
+
+	xmit = &port->state->xmit;
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return;
+
+	sunhv_ops->transmit_chars(port, xmit);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct tty_port *tport;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tport = receive_chars(port);
+	transmit_chars(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (tport)
+		tty_flip_buffer_push(tport);
+
+	return IRQ_HANDLED;
+}
+
+/* port->lock is not held.  */
+static unsigned int sunhv_tx_empty(struct uart_port *port)
+{
+	/* Transmitter is always empty for us.  If the circ buffer
+	 * is non-empty or there is an x_char pending, our caller
+	 * will do the right thing and ignore what we return here.
+	 */
+	return TIOCSER_TEMT;
+}
+
+/* port->lock held by caller.  */
+static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	return;
+}
+
+/* port->lock is held by caller and interrupts are disabled.  */
+static unsigned int sunhv_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;
+}
+
+/* port->lock held by caller.  */
+static void sunhv_stop_tx(struct uart_port *port)
+{
+	return;
+}
+
+/* port->lock held by caller.  */
+static void sunhv_start_tx(struct uart_port *port)
+{
+	transmit_chars(port);
+}
+
+/* port->lock is not held.  */
+static void sunhv_send_xchar(struct uart_port *port, char ch)
+{
+	unsigned long flags;
+	int limit = 10000;
+
+	if (ch == __DISABLED_CHAR)
+		return;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (limit-- > 0) {
+		long status = sun4v_con_putchar(ch);
+		if (status == HV_EOK)
+			break;
+		udelay(1);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* port->lock held by caller.  */
+static void sunhv_stop_rx(struct uart_port *port)
+{
+}
+
+/* port->lock is not held.  */
+static void sunhv_break_ctl(struct uart_port *port, int break_state)
+{
+	if (break_state) {
+		unsigned long flags;
+		int limit = 10000;
+
+		spin_lock_irqsave(&port->lock, flags);
+
+		while (limit-- > 0) {
+			long status = sun4v_con_putchar(CON_BREAK);
+			if (status == HV_EOK)
+				break;
+			udelay(1);
+		}
+
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+}
+
+/* port->lock is not held.  */
+static int sunhv_startup(struct uart_port *port)
+{
+	return 0;
+}
+
+/* port->lock is not held.  */
+static void sunhv_shutdown(struct uart_port *port)
+{
+}
+
+/* port->lock is not held.  */
+static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
+			      const struct ktermios *old)
+{
+	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+	unsigned int quot = uart_get_divisor(port, baud);
+	unsigned int iflag, cflag;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	iflag = termios->c_iflag;
+	cflag = termios->c_cflag;
+
+	port->ignore_status_mask = 0;
+	if (iflag & IGNBRK)
+		port->ignore_status_mask |= IGNORE_BREAK;
+	if ((cflag & CREAD) == 0)
+		port->ignore_status_mask |= IGNORE_ALL;
+
+	/* XXX */
+	uart_update_timeout(port, cflag,
+			    (port->uartclk / (16 * quot)));
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *sunhv_type(struct uart_port *port)
+{
+	return "SUN4V HCONS";
+}
+
+static void sunhv_release_port(struct uart_port *port)
+{
+}
+
+static int sunhv_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sunhv_config_port(struct uart_port *port, int flags)
+{
+}
+
+static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const struct uart_ops sunhv_pops = {
+	.tx_empty	= sunhv_tx_empty,
+	.set_mctrl	= sunhv_set_mctrl,
+	.get_mctrl	= sunhv_get_mctrl,
+	.stop_tx	= sunhv_stop_tx,
+	.start_tx	= sunhv_start_tx,
+	.send_xchar	= sunhv_send_xchar,
+	.stop_rx	= sunhv_stop_rx,
+	.break_ctl	= sunhv_break_ctl,
+	.startup	= sunhv_startup,
+	.shutdown	= sunhv_shutdown,
+	.set_termios	= sunhv_set_termios,
+	.type		= sunhv_type,
+	.release_port	= sunhv_release_port,
+	.request_port	= sunhv_request_port,
+	.config_port	= sunhv_config_port,
+	.verify_port	= sunhv_verify_port,
+};
+
+static struct uart_driver sunhv_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "sunhv",
+	.dev_name		= "ttyHV",
+	.major			= TTY_MAJOR,
+};
+
+static struct uart_port *sunhv_port;
+
+void sunhv_migrate_hvcons_irq(int cpu)
+{
+	/* Migrate hvcons irq to param cpu */
+	irq_force_affinity(sunhv_port->irq, cpumask_of(cpu));
+}
+
+/* Copy 's' into the con_write_page, decoding "\n" into
+ * "\r\n" along the way.  We have to return two lengths
+ * because the caller needs to know how much to advance
+ * 's' and also how many bytes to output via con_write_page.
+ */
+static int fill_con_write_page(const char *s, unsigned int n,
+			       unsigned long *page_bytes)
+{
+	const char *orig_s = s;
+	char *p = con_write_page;
+	int left = PAGE_SIZE;
+
+	while (n--) {
+		if (*s == '\n') {
+			if (left < 2)
+				break;
+			*p++ = '\r';
+			left--;
+		} else if (left < 1)
+			break;
+		*p++ = *s++;
+		left--;
+	}
+	*page_bytes = p - con_write_page;
+	return s - orig_s;
+}
+
+static void sunhv_console_write_paged(struct console *con, const char *s, unsigned n)
+{
+	struct uart_port *port = sunhv_port;
+	unsigned long flags;
+	int locked = 1;
+
+	if (port->sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	while (n > 0) {
+		unsigned long ra = __pa(con_write_page);
+		unsigned long page_bytes;
+		unsigned int cpy = fill_con_write_page(s, n,
+						       &page_bytes);
+
+		n -= cpy;
+		s += cpy;
+		while (page_bytes > 0) {
+			unsigned long written;
+			int limit = 1000000;
+
+			while (limit--) {
+				unsigned long stat;
+
+				stat = sun4v_con_write(ra, page_bytes,
+						       &written);
+				if (stat == HV_EOK)
+					break;
+				udelay(1);
+			}
+			if (limit < 0)
+				break;
+			page_bytes -= written;
+			ra += written;
+		}
+	}
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static inline void sunhv_console_putchar(struct uart_port *port, char c)
+{
+	int limit = 1000000;
+
+	while (limit-- > 0) {
+		long status = sun4v_con_putchar(c);
+		if (status == HV_EOK)
+			break;
+		udelay(1);
+	}
+}
+
+static void sunhv_console_write_bychar(struct console *con, const char *s, unsigned n)
+{
+	struct uart_port *port = sunhv_port;
+	unsigned long flags;
+	int i, locked = 1;
+
+	if (port->sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	for (i = 0; i < n; i++) {
+		if (*s == '\n')
+			sunhv_console_putchar(port, '\r');
+		sunhv_console_putchar(port, *s++);
+	}
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static struct console sunhv_console = {
+	.name	=	"ttyHV",
+	.write	=	sunhv_console_write_bychar,
+	.device	=	uart_console_device,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data	=	&sunhv_reg,
+};
+
+static int hv_probe(struct platform_device *op)
+{
+	struct uart_port *port;
+	unsigned long minor;
+	int err;
+
+	if (op->archdata.irqs[0] == 0xffffffff)
+		return -ENODEV;
+
+	port = kzalloc(sizeof(struct uart_port), GFP_KERNEL);
+	if (unlikely(!port))
+		return -ENOMEM;
+
+	minor = 1;
+	if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 &&
+	    minor >= 1) {
+		err = -ENOMEM;
+		con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!con_write_page)
+			goto out_free_port;
+
+		con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!con_read_page)
+			goto out_free_con_write_page;
+
+		sunhv_console.write = sunhv_console_write_paged;
+		sunhv_ops = &bywrite_ops;
+	}
+
+	sunhv_port = port;
+
+	port->has_sysrq = 1;
+	port->line = 0;
+	port->ops = &sunhv_pops;
+	port->type = PORT_SUNHV;
+	port->uartclk = ( 29491200 / 16 ); /* arbitrary */
+
+	port->membase = (unsigned char __iomem *) __pa(port);
+
+	port->irq = op->archdata.irqs[0];
+
+	port->dev = &op->dev;
+
+	err = sunserial_register_minors(&sunhv_reg, 1);
+	if (err)
+		goto out_free_con_read_page;
+
+	sunserial_console_match(&sunhv_console, op->dev.of_node,
+				&sunhv_reg, port->line, false);
+
+	err = uart_add_one_port(&sunhv_reg, port);
+	if (err)
+		goto out_unregister_driver;
+
+	err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port);
+	if (err)
+		goto out_remove_port;
+
+	platform_set_drvdata(op, port);
+
+	return 0;
+
+out_remove_port:
+	uart_remove_one_port(&sunhv_reg, port);
+
+out_unregister_driver:
+	sunserial_unregister_minors(&sunhv_reg, 1);
+
+out_free_con_read_page:
+	kfree(con_read_page);
+
+out_free_con_write_page:
+	kfree(con_write_page);
+
+out_free_port:
+	kfree(port);
+	sunhv_port = NULL;
+	return err;
+}
+
+static int hv_remove(struct platform_device *dev)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+
+	free_irq(port->irq, port);
+
+	uart_remove_one_port(&sunhv_reg, port);
+
+	sunserial_unregister_minors(&sunhv_reg, 1);
+	kfree(con_read_page);
+	kfree(con_write_page);
+	kfree(port);
+	sunhv_port = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id hv_match[] = {
+	{
+		.name = "console",
+		.compatible = "qcn",
+	},
+	{
+		.name = "console",
+		.compatible = "SUNW,sun4v-console",
+	},
+	{},
+};
+
+static struct platform_driver hv_driver = {
+	.driver = {
+		.name = "hv",
+		.of_match_table = hv_match,
+	},
+	.probe		= hv_probe,
+	.remove		= hv_remove,
+};
+
+static int __init sunhv_init(void)
+{
+	if (tlb_type != hypervisor)
+		return -ENODEV;
+
+	return platform_driver_register(&hv_driver);
+}
+device_initcall(sunhv_init);
+
+#if 0 /* ...def MODULE ; never supported as such */
+MODULE_AUTHOR("David S. Miller");
+MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
+MODULE_VERSION("2.0");
+MODULE_LICENSE("GPL");
+#endif
diff --git a/drivers/tty/serial/sunplus-uart.c b/drivers/tty/serial/sunplus-uart.c
new file mode 100644
index 000000000..3aacd5eb4
--- /dev/null
+++ b/drivers/tty/serial/sunplus-uart.c
@@ -0,0 +1,773 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sunplus SoC UART driver
+ *
+ * Author: Hammer Hsieh <hammerh0314@gmail.com>
+ *
+ * Note1: This driver is 8250-like uart, but are not register compatible.
+ *
+ * Note2: On some buses, for preventing data incoherence, must do a read
+ * for ensure write made it to hardware. In this driver, function startup
+ * and shutdown did not do a read but only do a write directly. For what?
+ * In Sunplus bus communication between memory bus and peripheral bus with
+ * posted write, it will send a specific command after last write command
+ * to make sure write done. Then memory bus identify the specific command
+ * and send done signal back to master device. After master device received
+ * done signal, then proceed next write command. It is no need to do a read
+ * before write.
+ */
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <asm/irq.h>
+
+/* Register offsets */
+#define SUP_UART_DATA			0x00
+#define SUP_UART_LSR			0x04
+#define SUP_UART_MSR			0x08
+#define SUP_UART_LCR			0x0C
+#define SUP_UART_MCR			0x10
+#define SUP_UART_DIV_L			0x14
+#define SUP_UART_DIV_H			0x18
+#define SUP_UART_ISC			0x1C
+#define SUP_UART_TX_RESIDUE		0x20
+#define SUP_UART_RX_RESIDUE		0x24
+
+/* Line Status Register bits */
+#define SUP_UART_LSR_BC			BIT(5) /* break condition status */
+#define SUP_UART_LSR_FE			BIT(4) /* frame error status */
+#define SUP_UART_LSR_OE			BIT(3) /* overrun error status */
+#define SUP_UART_LSR_PE			BIT(2) /* parity error status */
+#define SUP_UART_LSR_RX			BIT(1) /* 1: receive fifo not empty */
+#define SUP_UART_LSR_TX			BIT(0) /* 1: transmit fifo is not full */
+#define SUP_UART_LSR_TX_NOT_FULL	1
+#define SUP_UART_LSR_BRK_ERROR_BITS	GENMASK(5, 2)
+
+/* Line Control Register bits */
+#define SUP_UART_LCR_SBC		BIT(5) /* select break condition */
+
+/* Modem Control Register bits */
+#define SUP_UART_MCR_RI			BIT(3) /* ring indicator */
+#define SUP_UART_MCR_DCD		BIT(2) /* data carrier detect */
+
+/* Interrupt Status/Control Register bits */
+#define SUP_UART_ISC_RXM		BIT(5) /* RX interrupt enable */
+#define SUP_UART_ISC_TXM		BIT(4) /* TX interrupt enable */
+#define SUP_UART_ISC_RX			BIT(1) /* RX interrupt status */
+#define SUP_UART_ISC_TX			BIT(0) /* TX interrupt status */
+
+#define SUP_DUMMY_READ			BIT(16) /* drop bytes received on a !CREAD port */
+#define SUP_UART_NR			5
+
+struct sunplus_uart_port {
+	struct uart_port port;
+	struct clk *clk;
+	struct reset_control *rstc;
+};
+
+static void sp_uart_put_char(struct uart_port *port, unsigned int ch)
+{
+	writel(ch, port->membase + SUP_UART_DATA);
+}
+
+static u32 sunplus_tx_buf_not_full(struct uart_port *port)
+{
+	unsigned int lsr = readl(port->membase + SUP_UART_LSR);
+
+	return (lsr & SUP_UART_LSR_TX) ? SUP_UART_LSR_TX_NOT_FULL : 0;
+}
+
+static unsigned int sunplus_tx_empty(struct uart_port *port)
+{
+	unsigned int lsr = readl(port->membase + SUP_UART_LSR);
+
+	return (lsr & UART_LSR_TEMT) ? TIOCSER_TEMT : 0;
+}
+
+static void sunplus_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int mcr = readl(port->membase + SUP_UART_MCR);
+
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	else
+		mcr &= ~UART_MCR_DTR;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	else
+		mcr &= ~UART_MCR_RTS;
+
+	if (mctrl & TIOCM_CAR)
+		mcr |= SUP_UART_MCR_DCD;
+	else
+		mcr &= ~SUP_UART_MCR_DCD;
+
+	if (mctrl & TIOCM_RI)
+		mcr |= SUP_UART_MCR_RI;
+	else
+		mcr &= ~SUP_UART_MCR_RI;
+
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+	else
+		mcr &= ~UART_MCR_LOOP;
+
+	writel(mcr, port->membase + SUP_UART_MCR);
+}
+
+static unsigned int sunplus_get_mctrl(struct uart_port *port)
+{
+	unsigned int mcr, ret = 0;
+
+	mcr = readl(port->membase + SUP_UART_MCR);
+
+	if (mcr & UART_MCR_DTR)
+		ret |= TIOCM_DTR;
+
+	if (mcr & UART_MCR_RTS)
+		ret |= TIOCM_RTS;
+
+	if (mcr & SUP_UART_MCR_DCD)
+		ret |= TIOCM_CAR;
+
+	if (mcr & SUP_UART_MCR_RI)
+		ret |= TIOCM_RI;
+
+	if (mcr & UART_MCR_LOOP)
+		ret |= TIOCM_LOOP;
+
+	return ret;
+}
+
+static void sunplus_stop_tx(struct uart_port *port)
+{
+	unsigned int isc;
+
+	isc = readl(port->membase + SUP_UART_ISC);
+	isc &= ~SUP_UART_ISC_TXM;
+	writel(isc, port->membase + SUP_UART_ISC);
+}
+
+static void sunplus_start_tx(struct uart_port *port)
+{
+	unsigned int isc;
+
+	isc = readl(port->membase + SUP_UART_ISC);
+	isc |= SUP_UART_ISC_TXM;
+	writel(isc, port->membase + SUP_UART_ISC);
+}
+
+static void sunplus_stop_rx(struct uart_port *port)
+{
+	unsigned int isc;
+
+	isc = readl(port->membase + SUP_UART_ISC);
+	isc &= ~SUP_UART_ISC_RXM;
+	writel(isc, port->membase + SUP_UART_ISC);
+}
+
+static void sunplus_break_ctl(struct uart_port *port, int ctl)
+{
+	unsigned long flags;
+	unsigned int lcr;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	lcr = readl(port->membase + SUP_UART_LCR);
+
+	if (ctl)
+		lcr |= SUP_UART_LCR_SBC; /* start break */
+	else
+		lcr &= ~SUP_UART_LCR_SBC; /* stop break */
+
+	writel(lcr, port->membase + SUP_UART_LCR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void transmit_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (port->x_char) {
+		sp_uart_put_char(port, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		sunplus_stop_tx(port);
+		return;
+	}
+
+	do {
+		sp_uart_put_char(port, xmit->buf[xmit->tail]);
+		uart_xmit_advance(port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+	} while (sunplus_tx_buf_not_full(port));
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		sunplus_stop_tx(port);
+}
+
+static void receive_chars(struct uart_port *port)
+{
+	unsigned int lsr = readl(port->membase + SUP_UART_LSR);
+	u8 ch, flag;
+
+	do {
+		ch = readl(port->membase + SUP_UART_DATA);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (unlikely(lsr & SUP_UART_LSR_BRK_ERROR_BITS)) {
+			if (lsr & SUP_UART_LSR_BC) {
+				lsr &= ~(SUP_UART_LSR_FE | SUP_UART_LSR_PE);
+				port->icount.brk++;
+				flag = TTY_BREAK;
+				if (uart_handle_break(port))
+					goto ignore_char;
+			} else if (lsr & SUP_UART_LSR_PE) {
+				port->icount.parity++;
+				flag = TTY_PARITY;
+			} else if (lsr & SUP_UART_LSR_FE) {
+				port->icount.frame++;
+				flag = TTY_FRAME;
+			}
+
+			if (lsr & SUP_UART_LSR_OE)
+				port->icount.overrun++;
+		}
+
+		if (port->ignore_status_mask & SUP_DUMMY_READ)
+			goto ignore_char;
+
+		if (uart_handle_sysrq_char(port, ch))
+			goto ignore_char;
+
+		uart_insert_char(port, lsr, SUP_UART_LSR_OE, ch, flag);
+
+ignore_char:
+		lsr = readl(port->membase + SUP_UART_LSR);
+	} while (lsr & SUP_UART_LSR_RX);
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static irqreturn_t sunplus_uart_irq(int irq, void *args)
+{
+	struct uart_port *port = args;
+	unsigned int isc;
+
+	spin_lock(&port->lock);
+
+	isc = readl(port->membase + SUP_UART_ISC);
+
+	if (isc & SUP_UART_ISC_RX)
+		receive_chars(port);
+
+	if (isc & SUP_UART_ISC_TX)
+		transmit_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sunplus_startup(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned int isc = 0;
+	int ret;
+
+	ret = request_irq(port->irq, sunplus_uart_irq, 0, "sunplus_uart", port);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+	/* isc define Bit[7:4] int setting, Bit[3:0] int status
+	 * isc register will clean Bit[3:0] int status after read
+	 * only do a write to Bit[7:4] int setting
+	 */
+	isc |= SUP_UART_ISC_RXM;
+	writel(isc, port->membase + SUP_UART_ISC);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void sunplus_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	/* isc define Bit[7:4] int setting, Bit[3:0] int status
+	 * isc register will clean Bit[3:0] int status after read
+	 * only do a write to Bit[7:4] int setting
+	 */
+	writel(0, port->membase + SUP_UART_ISC); /* disable all interrupt */
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+static void sunplus_set_termios(struct uart_port *port,
+				struct ktermios *termios,
+				const struct ktermios *oldtermios)
+{
+	u32 ext, div, div_l, div_h, baud, lcr;
+	u32 clk = port->uartclk;
+	unsigned long flags;
+
+	baud = uart_get_baud_rate(port, termios, oldtermios, 0, port->uartclk / 16);
+
+	/* baud rate = uartclk / ((16 * divisor + 1) + divisor_ext) */
+	clk += baud >> 1;
+	div = clk / baud;
+	ext = div & 0x0F;
+	div = (div >> 4) - 1;
+	div_l = (div & 0xFF) | (ext << 12);
+	div_h = div >> 8;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr = UART_LCR_WLEN5;
+		break;
+	case CS6:
+		lcr = UART_LCR_WLEN6;
+		break;
+	case CS7:
+		lcr = UART_LCR_WLEN7;
+		break;
+	default:
+		lcr = UART_LCR_WLEN8;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		lcr |= UART_LCR_STOP;
+
+	if (termios->c_cflag & PARENB) {
+		lcr |= UART_LCR_PARITY;
+
+		if (!(termios->c_cflag & PARODD))
+			lcr |= UART_LCR_EPAR;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= SUP_UART_LSR_PE | SUP_UART_LSR_FE;
+
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		port->read_status_mask |= SUP_UART_LSR_BC;
+
+	/* Characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= SUP_UART_LSR_FE | SUP_UART_LSR_PE;
+
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= SUP_UART_LSR_BC;
+
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= SUP_UART_LSR_OE;
+	}
+
+	/* Ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0) {
+		port->ignore_status_mask |= SUP_DUMMY_READ;
+		/* flush rx data FIFO */
+		writel(0, port->membase + SUP_UART_RX_RESIDUE);
+	}
+
+	/* Settings for baud rate divisor and lcr */
+	writel(div_h, port->membase + SUP_UART_DIV_H);
+	writel(div_l, port->membase + SUP_UART_DIV_L);
+	writel(lcr, port->membase + SUP_UART_LCR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void sunplus_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	int new = termios->c_line;
+
+	if (new == N_PPS)
+		port->flags |= UPF_HARDPPS_CD;
+	else
+		port->flags &= ~UPF_HARDPPS_CD;
+}
+
+static const char *sunplus_type(struct uart_port *port)
+{
+	return port->type == PORT_SUNPLUS ? "sunplus_uart" : NULL;
+}
+
+static void sunplus_config_port(struct uart_port *port, int type)
+{
+	if (type & UART_CONFIG_TYPE)
+		port->type = PORT_SUNPLUS;
+}
+
+static int sunplus_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SUNPLUS)
+		return -EINVAL;
+
+	return 0;
+}
+
+#if defined(CONFIG_SERIAL_SUNPLUS_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
+static void wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int val;
+	int ret;
+
+	/* Wait while FIFO is full or timeout */
+	ret = readl_poll_timeout_atomic(port->membase + SUP_UART_LSR, val,
+					(val & SUP_UART_LSR_TX), 1, 10000);
+
+	if (ret == -ETIMEDOUT) {
+		dev_err(port->dev, "Timeout waiting while UART TX FULL\n");
+		return;
+	}
+}
+#endif
+
+#ifdef CONFIG_CONSOLE_POLL
+static void sunplus_poll_put_char(struct uart_port *port, unsigned char data)
+{
+	wait_for_xmitr(port);
+	sp_uart_put_char(port, data);
+}
+
+static int sunplus_poll_get_char(struct uart_port *port)
+{
+	unsigned int lsr = readl(port->membase + SUP_UART_LSR);
+
+	if (!(lsr & SUP_UART_LSR_RX))
+		return NO_POLL_CHAR;
+
+	return readl(port->membase + SUP_UART_DATA);
+}
+#endif
+
+static const struct uart_ops sunplus_uart_ops = {
+	.tx_empty	= sunplus_tx_empty,
+	.set_mctrl	= sunplus_set_mctrl,
+	.get_mctrl	= sunplus_get_mctrl,
+	.stop_tx	= sunplus_stop_tx,
+	.start_tx	= sunplus_start_tx,
+	.stop_rx	= sunplus_stop_rx,
+	.break_ctl	= sunplus_break_ctl,
+	.startup	= sunplus_startup,
+	.shutdown	= sunplus_shutdown,
+	.set_termios	= sunplus_set_termios,
+	.set_ldisc	= sunplus_set_ldisc,
+	.type		= sunplus_type,
+	.config_port	= sunplus_config_port,
+	.verify_port	= sunplus_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_put_char	= sunplus_poll_put_char,
+	.poll_get_char	= sunplus_poll_get_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_SUNPLUS_CONSOLE
+static struct sunplus_uart_port *sunplus_console_ports[SUP_UART_NR];
+
+static void sunplus_uart_console_putchar(struct uart_port *port,
+					 unsigned char ch)
+{
+	wait_for_xmitr(port);
+	sp_uart_put_char(port, ch);
+}
+
+static void sunplus_console_write(struct console *co,
+				  const char *s,
+				  unsigned int count)
+{
+	unsigned long flags;
+	int locked = 1;
+
+	local_irq_save(flags);
+
+	if (sunplus_console_ports[co->index]->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&sunplus_console_ports[co->index]->port.lock);
+	else
+		spin_lock(&sunplus_console_ports[co->index]->port.lock);
+
+	uart_console_write(&sunplus_console_ports[co->index]->port, s, count,
+			   sunplus_uart_console_putchar);
+
+	if (locked)
+		spin_unlock(&sunplus_console_ports[co->index]->port.lock);
+
+	local_irq_restore(flags);
+}
+
+static int __init sunplus_console_setup(struct console *co, char *options)
+{
+	struct sunplus_uart_port *sup;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= SUP_UART_NR)
+		return -EINVAL;
+
+	sup = sunplus_console_ports[co->index];
+	if (!sup)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&sup->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sunplus_uart_driver;
+static struct console sunplus_uart_console = {
+	.name		= "ttySUP",
+	.write		= sunplus_console_write,
+	.device		= uart_console_device,
+	.setup		= sunplus_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &sunplus_uart_driver
+};
+
+#define	SERIAL_SUNPLUS_CONSOLE	(&sunplus_uart_console)
+#else
+#define	SERIAL_SUNPLUS_CONSOLE	NULL
+#endif
+
+static struct uart_driver sunplus_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "sunplus_uart",
+	.dev_name	= "ttySUP",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= SUP_UART_NR,
+	.cons		= SERIAL_SUNPLUS_CONSOLE,
+};
+
+static void sunplus_uart_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static void sunplus_uart_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int sunplus_uart_probe(struct platform_device *pdev)
+{
+	struct sunplus_uart_port *sup;
+	struct uart_port *port;
+	struct resource *res;
+	int ret, irq;
+
+	pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+
+	if (pdev->id < 0 || pdev->id >= SUP_UART_NR)
+		return -EINVAL;
+
+	sup = devm_kzalloc(&pdev->dev, sizeof(*sup), GFP_KERNEL);
+	if (!sup)
+		return -ENOMEM;
+
+	sup->clk = devm_clk_get_optional(&pdev->dev, NULL);
+	if (IS_ERR(sup->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(sup->clk), "clk not found\n");
+
+	ret = clk_prepare_enable(sup->clk);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(&pdev->dev, sunplus_uart_disable_unprepare, sup->clk);
+	if (ret)
+		return ret;
+
+	sup->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(sup->rstc))
+		return dev_err_probe(&pdev->dev, PTR_ERR(sup->rstc), "rstc not found\n");
+
+	port = &sup->port;
+
+	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(port->membase))
+		return dev_err_probe(&pdev->dev, PTR_ERR(port->membase), "membase not found\n");
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	port->mapbase = res->start;
+	port->uartclk = clk_get_rate(sup->clk);
+	port->line = pdev->id;
+	port->irq = irq;
+	port->dev = &pdev->dev;
+	port->iotype = UPIO_MEM;
+	port->ops = &sunplus_uart_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->fifosize = 128;
+
+	ret = reset_control_deassert(sup->rstc);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(&pdev->dev, sunplus_uart_reset_control_assert, sup->rstc);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_SERIAL_SUNPLUS_CONSOLE
+	sunplus_console_ports[sup->port.line] = sup;
+#endif
+
+	platform_set_drvdata(pdev, &sup->port);
+
+	ret = uart_add_one_port(&sunplus_uart_driver, &sup->port);
+#ifdef CONFIG_SERIAL_SUNPLUS_CONSOLE
+	if (ret)
+		sunplus_console_ports[sup->port.line] = NULL;
+#endif
+
+	return ret;
+}
+
+static int sunplus_uart_remove(struct platform_device *pdev)
+{
+	struct sunplus_uart_port *sup = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&sunplus_uart_driver, &sup->port);
+
+	return 0;
+}
+
+static int __maybe_unused sunplus_uart_suspend(struct device *dev)
+{
+	struct sunplus_uart_port *sup = dev_get_drvdata(dev);
+
+	if (!uart_console(&sup->port))
+		uart_suspend_port(&sunplus_uart_driver, &sup->port);
+
+	return 0;
+}
+
+static int __maybe_unused sunplus_uart_resume(struct device *dev)
+{
+	struct sunplus_uart_port *sup = dev_get_drvdata(dev);
+
+	if (!uart_console(&sup->port))
+		uart_resume_port(&sunplus_uart_driver, &sup->port);
+
+	return 0;
+}
+
+static const struct dev_pm_ops sunplus_uart_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(sunplus_uart_suspend, sunplus_uart_resume)
+};
+
+static const struct of_device_id sp_uart_of_match[] = {
+	{ .compatible = "sunplus,sp7021-uart" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sp_uart_of_match);
+
+static struct platform_driver sunplus_uart_platform_driver = {
+	.probe		= sunplus_uart_probe,
+	.remove		= sunplus_uart_remove,
+	.driver = {
+		.name	= "sunplus_uart",
+		.of_match_table = sp_uart_of_match,
+		.pm     = &sunplus_uart_pm_ops,
+	}
+};
+
+static int __init sunplus_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&sunplus_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&sunplus_uart_platform_driver);
+	if (ret)
+		uart_unregister_driver(&sunplus_uart_driver);
+
+	return ret;
+}
+module_init(sunplus_uart_init);
+
+static void __exit sunplus_uart_exit(void)
+{
+	platform_driver_unregister(&sunplus_uart_platform_driver);
+	uart_unregister_driver(&sunplus_uart_driver);
+}
+module_exit(sunplus_uart_exit);
+
+#ifdef CONFIG_SERIAL_EARLYCON
+static void sunplus_uart_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned int val;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(port->membase + SUP_UART_LSR, val,
+					(val & UART_LSR_TEMT), 1, 10000);
+	if (ret)
+		return;
+
+	writel(c, port->membase + SUP_UART_DATA);
+}
+
+static void sunplus_uart_early_write(struct console *con, const char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, sunplus_uart_putc);
+}
+
+static int __init
+sunplus_uart_early_setup(struct earlycon_device *dev, const char *opt)
+{
+	if (!(dev->port.membase || dev->port.iobase))
+		return -ENODEV;
+
+	dev->con->write = sunplus_uart_early_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(sunplus_uart, "sunplus,sp7021-uart", sunplus_uart_early_setup);
+#endif
+
+MODULE_DESCRIPTION("Sunplus UART driver");
+MODULE_AUTHOR("Hammer Hsieh <hammerh0314@gmail.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
new file mode 100644
index 000000000..40eeaf835
--- /dev/null
+++ b/drivers/tty/serial/sunsab.c
@@ -0,0 +1,1160 @@
+// SPDX-License-Identifier: GPL-2.0
+/* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
+ *
+ * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
+ * Copyright (C) 2002, 2006  David S. Miller (davem@davemloft.net)
+ *
+ * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
+ *   Maxim Krasnyanskiy <maxk@qualcomm.com>
+ *
+ * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
+ * rates to be programmed into the UART.  Also eliminated a lot of
+ * duplicated code in the console setup.
+ *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
+ *
+ * Ported to new 2.5.x UART layer.
+ *   David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <asm/prom.h>
+#include <asm/setup.h>
+
+#include <linux/serial_core.h>
+#include <linux/sunserialcore.h>
+
+#include "sunsab.h"
+
+struct uart_sunsab_port {
+	struct uart_port		port;		/* Generic UART port	*/
+	union sab82532_async_regs	__iomem *regs;	/* Chip registers	*/
+	unsigned long			irqflags;	/* IRQ state flags	*/
+	int				dsr;		/* Current DSR state	*/
+	unsigned int			cec_timeout;	/* Chip poll timeout... */
+	unsigned int			tec_timeout;	/* likewise		*/
+	unsigned char			interrupt_mask0;/* ISR0 masking		*/
+	unsigned char			interrupt_mask1;/* ISR1 masking		*/
+	unsigned char			pvr_dtr_bit;	/* Which PVR bit is DTR */
+	unsigned char			pvr_dsr_bit;	/* Which PVR bit is DSR */
+	unsigned int			gis_shift;
+	int				type;		/* SAB82532 version	*/
+
+	/* Setting configuration bits while the transmitter is active
+	 * can cause garbage characters to get emitted by the chip.
+	 * Therefore, we cache such writes here and do the real register
+	 * write the next time the transmitter becomes idle.
+	 */
+	unsigned int			cached_ebrg;
+	unsigned char			cached_mode;
+	unsigned char			cached_pvr;
+	unsigned char			cached_dafo;
+};
+
+/*
+ * This assumes you have a 29.4912 MHz clock for your UART.
+ */
+#define SAB_BASE_BAUD ( 29491200 / 16 )
+
+static char *sab82532_version[16] = {
+	"V1.0", "V2.0", "V3.2", "V(0x03)",
+	"V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
+	"V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
+	"V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
+};
+
+#define SAB82532_MAX_TEC_TIMEOUT 200000	/* 1 character time (at 50 baud) */
+#define SAB82532_MAX_CEC_TIMEOUT  50000	/* 2.5 TX CLKs (at 50 baud) */
+
+#define SAB82532_RECV_FIFO_SIZE	32      /* Standard async fifo sizes */
+#define SAB82532_XMIT_FIFO_SIZE	32
+
+static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
+{
+	int timeout = up->tec_timeout;
+
+	while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
+		udelay(1);
+}
+
+static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
+{
+	int timeout = up->cec_timeout;
+
+	while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
+		udelay(1);
+}
+
+static struct tty_port *
+receive_chars(struct uart_sunsab_port *up,
+	      union sab82532_irq_status *stat)
+{
+	struct tty_port *port = NULL;
+	unsigned char buf[32];
+	int saw_console_brk = 0;
+	int free_fifo = 0;
+	int count = 0;
+	int i;
+
+	if (up->port.state != NULL)		/* Unopened serial console */
+		port = &up->port.state->port;
+
+	/* Read number of BYTES (Character + Status) available. */
+	if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
+		count = SAB82532_RECV_FIFO_SIZE;
+		free_fifo++;
+	}
+
+	if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
+		count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
+		free_fifo++;
+	}
+
+	/* Issue a FIFO read command in case we where idle. */
+	if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
+		sunsab_cec_wait(up);
+		writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
+		return port;
+	}
+
+	if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
+		free_fifo++;
+
+	/* Read the FIFO. */
+	for (i = 0; i < count; i++)
+		buf[i] = readb(&up->regs->r.rfifo[i]);
+
+	/* Issue Receive Message Complete command. */
+	if (free_fifo) {
+		sunsab_cec_wait(up);
+		writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
+	}
+
+	/* Count may be zero for BRK, so we check for it here */
+	if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
+	    (up->port.line == up->port.cons->index))
+		saw_console_brk = 1;
+
+	if (count == 0) {
+		if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
+			stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
+					     SAB82532_ISR0_FERR);
+			up->port.icount.brk++;
+			uart_handle_break(&up->port);
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		unsigned char ch = buf[i], flag;
+
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
+						SAB82532_ISR0_FERR |
+						SAB82532_ISR0_RFO)) ||
+		    unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
+			/*
+			 * For statistics only
+			 */
+			if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
+				stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
+						     SAB82532_ISR0_FERR);
+				up->port.icount.brk++;
+				/*
+				 * We do the SysRQ and SAK checking
+				 * here because otherwise the break
+				 * may get masked by ignore_status_mask
+				 * or read_status_mask.
+				 */
+				if (uart_handle_break(&up->port))
+					continue;
+			} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
+				up->port.icount.parity++;
+			else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
+				up->port.icount.frame++;
+			if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
+				up->port.icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ingored.
+			 */
+			stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
+			stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
+
+			if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
+				flag = TTY_BREAK;
+			} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
+				flag = TTY_PARITY;
+			else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(&up->port, ch) || !port)
+			continue;
+
+		if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
+		    (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
+			tty_insert_flip_char(port, ch, flag);
+		if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
+			tty_insert_flip_char(port, 0, TTY_OVERRUN);
+	}
+
+	if (saw_console_brk)
+		sun_do_break();
+
+	return port;
+}
+
+static void sunsab_stop_tx(struct uart_port *);
+static void sunsab_tx_idle(struct uart_sunsab_port *);
+
+static void transmit_chars(struct uart_sunsab_port *up,
+			   union sab82532_irq_status *stat)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int i;
+
+	if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
+		up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
+		writeb(up->interrupt_mask1, &up->regs->w.imr1);
+		set_bit(SAB82532_ALLS, &up->irqflags);
+	}
+
+#if 0 /* bde@nwlink.com says this check causes problems */
+	if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
+		return;
+#endif
+
+	if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
+		return;
+
+	set_bit(SAB82532_XPR, &up->irqflags);
+	sunsab_tx_idle(up);
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
+		up->interrupt_mask1 |= SAB82532_IMR1_XPR;
+		writeb(up->interrupt_mask1, &up->regs->w.imr1);
+		return;
+	}
+
+	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+	clear_bit(SAB82532_ALLS, &up->irqflags);
+
+	/* Stuff 32 bytes into Transmit FIFO. */
+	clear_bit(SAB82532_XPR, &up->irqflags);
+	for (i = 0; i < up->port.fifosize; i++) {
+		writeb(xmit->buf[xmit->tail],
+		       &up->regs->w.xfifo[i]);
+		uart_xmit_advance(&up->port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+	}
+
+	/* Issue a Transmit Frame command. */
+	sunsab_cec_wait(up);
+	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (uart_circ_empty(xmit))
+		sunsab_stop_tx(&up->port);
+}
+
+static void check_status(struct uart_sunsab_port *up,
+			 union sab82532_irq_status *stat)
+{
+	if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
+		uart_handle_dcd_change(&up->port,
+				       !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
+
+	if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
+		uart_handle_cts_change(&up->port,
+				       (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
+
+	if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
+		up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
+		up->port.icount.dsr++;
+	}
+
+	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+}
+
+static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
+{
+	struct uart_sunsab_port *up = dev_id;
+	struct tty_port *port = NULL;
+	union sab82532_irq_status status;
+	unsigned long flags;
+	unsigned char gis;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	status.stat = 0;
+	gis = readb(&up->regs->r.gis) >> up->gis_shift;
+	if (gis & 1)
+		status.sreg.isr0 = readb(&up->regs->r.isr0);
+	if (gis & 2)
+		status.sreg.isr1 = readb(&up->regs->r.isr1);
+
+	if (status.stat) {
+		if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
+					 SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
+		    (status.sreg.isr1 & SAB82532_ISR1_BRK))
+			port = receive_chars(up, &status);
+		if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
+		    (status.sreg.isr1 & SAB82532_ISR1_CSC))
+			check_status(up, &status);
+		if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
+			transmit_chars(up, &status);
+	}
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	if (port)
+		tty_flip_buffer_push(port);
+
+	return IRQ_HANDLED;
+}
+
+/* port->lock is not held.  */
+static unsigned int sunsab_tx_empty(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	int ret;
+
+	/* Do not need a lock for a state test like this.  */
+	if (test_bit(SAB82532_ALLS, &up->irqflags))
+		ret = TIOCSER_TEMT;
+	else
+		ret = 0;
+
+	return ret;
+}
+
+/* port->lock held by caller.  */
+static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	if (mctrl & TIOCM_RTS) {
+		up->cached_mode &= ~SAB82532_MODE_FRTS;
+		up->cached_mode |= SAB82532_MODE_RTS;
+	} else {
+		up->cached_mode |= (SAB82532_MODE_FRTS |
+				    SAB82532_MODE_RTS);
+	}
+	if (mctrl & TIOCM_DTR) {
+		up->cached_pvr &= ~(up->pvr_dtr_bit);
+	} else {
+		up->cached_pvr |= up->pvr_dtr_bit;
+	}
+
+	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
+	if (test_bit(SAB82532_XPR, &up->irqflags))
+		sunsab_tx_idle(up);
+}
+
+/* port->lock is held by caller and interrupts are disabled.  */
+static unsigned int sunsab_get_mctrl(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned char val;
+	unsigned int result;
+
+	result = 0;
+
+	val = readb(&up->regs->r.pvr);
+	result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
+
+	val = readb(&up->regs->r.vstr);
+	result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
+
+	val = readb(&up->regs->r.star);
+	result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
+
+	return result;
+}
+
+/* port->lock held by caller.  */
+static void sunsab_stop_tx(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	up->interrupt_mask1 |= SAB82532_IMR1_XPR;
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+}
+
+/* port->lock held by caller.  */
+static void sunsab_tx_idle(struct uart_sunsab_port *up)
+{
+	if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
+		u8 tmp;
+
+		clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
+		writeb(up->cached_mode, &up->regs->rw.mode);
+		writeb(up->cached_pvr, &up->regs->rw.pvr);
+		writeb(up->cached_dafo, &up->regs->w.dafo);
+
+		writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
+		tmp = readb(&up->regs->rw.ccr2);
+		tmp &= ~0xc0;
+		tmp |= (up->cached_ebrg >> 2) & 0xc0;
+		writeb(tmp, &up->regs->rw.ccr2);
+	}
+}
+
+/* port->lock held by caller.  */
+static void sunsab_start_tx(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int i;
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return;
+
+	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+	
+	if (!test_bit(SAB82532_XPR, &up->irqflags))
+		return;
+
+	clear_bit(SAB82532_ALLS, &up->irqflags);
+	clear_bit(SAB82532_XPR, &up->irqflags);
+
+	for (i = 0; i < up->port.fifosize; i++) {
+		writeb(xmit->buf[xmit->tail],
+		       &up->regs->w.xfifo[i]);
+		uart_xmit_advance(&up->port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+	}
+
+	/* Issue a Transmit Frame command.  */
+	sunsab_cec_wait(up);
+	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
+}
+
+/* port->lock is not held.  */
+static void sunsab_send_xchar(struct uart_port *port, char ch)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+
+	if (ch == __DISABLED_CHAR)
+		return;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	sunsab_tec_wait(up);
+	writeb(ch, &up->regs->w.tic);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/* port->lock held by caller.  */
+static void sunsab_stop_rx(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	up->interrupt_mask0 |= SAB82532_IMR0_TCD;
+	writeb(up->interrupt_mask1, &up->regs->w.imr0);
+}
+
+/* port->lock is not held.  */
+static void sunsab_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+	unsigned char val;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	val = up->cached_dafo;
+	if (break_state)
+		val |= SAB82532_DAFO_XBRK;
+	else
+		val &= ~SAB82532_DAFO_XBRK;
+	up->cached_dafo = val;
+
+	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
+	if (test_bit(SAB82532_XPR, &up->irqflags))
+		sunsab_tx_idle(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/* port->lock is not held.  */
+static int sunsab_startup(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+	unsigned char tmp;
+	int err = request_irq(up->port.irq, sunsab_interrupt,
+			      IRQF_SHARED, "sab", up);
+	if (err)
+		return err;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Wait for any commands or immediate characters
+	 */
+	sunsab_cec_wait(up);
+	sunsab_tec_wait(up);
+
+	/*
+	 * Clear the FIFO buffers.
+	 */
+	writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
+	sunsab_cec_wait(up);
+	writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) readb(&up->regs->r.isr0);
+	(void) readb(&up->regs->r.isr1);
+
+	/*
+	 * Now, initialize the UART 
+	 */
+	writeb(0, &up->regs->w.ccr0);				/* power-down */
+	writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
+	       SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
+	writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
+	writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
+	       SAB82532_CCR2_TOE, &up->regs->w.ccr2);
+	writeb(0, &up->regs->w.ccr3);
+	writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
+	up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
+			   SAB82532_MODE_RAC);
+	writeb(up->cached_mode, &up->regs->w.mode);
+	writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
+	
+	tmp = readb(&up->regs->rw.ccr0);
+	tmp |= SAB82532_CCR0_PU;	/* power-up */
+	writeb(tmp, &up->regs->rw.ccr0);
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
+			       SAB82532_IMR0_PLLA);
+	writeb(up->interrupt_mask0, &up->regs->w.imr0);
+	up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
+			       SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
+			       SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
+			       SAB82532_IMR1_XPR);
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+	set_bit(SAB82532_ALLS, &up->irqflags);
+	set_bit(SAB82532_XPR, &up->irqflags);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return 0;
+}
+
+/* port->lock is not held.  */
+static void sunsab_shutdown(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/* Disable Interrupts */
+	up->interrupt_mask0 = 0xff;
+	writeb(up->interrupt_mask0, &up->regs->w.imr0);
+	up->interrupt_mask1 = 0xff;
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+
+	/* Disable break condition */
+	up->cached_dafo = readb(&up->regs->rw.dafo);
+	up->cached_dafo &= ~SAB82532_DAFO_XBRK;
+	writeb(up->cached_dafo, &up->regs->rw.dafo);
+
+	/* Disable Receiver */	
+	up->cached_mode &= ~SAB82532_MODE_RAC;
+	writeb(up->cached_mode, &up->regs->rw.mode);
+
+	/*
+	 * XXX FIXME
+	 *
+	 * If the chip is powered down here the system hangs/crashes during
+	 * reboot or shutdown.  This needs to be investigated further,
+	 * similar behaviour occurs in 2.4 when the driver is configured
+	 * as a module only.  One hint may be that data is sometimes
+	 * transmitted at 9600 baud during shutdown (regardless of the
+	 * speed the chip was configured for when the port was open).
+	 */
+#if 0
+	/* Power Down */	
+	tmp = readb(&up->regs->rw.ccr0);
+	tmp &= ~SAB82532_CCR0_PU;
+	writeb(tmp, &up->regs->rw.ccr0);
+#endif
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	free_irq(up->port.irq, up);
+}
+
+/*
+ * This is used to figure out the divisor speeds.
+ *
+ * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
+ *
+ * with               0 <= N < 64 and 0 <= M < 16
+ */
+
+static void calc_ebrg(int baud, int *n_ret, int *m_ret)
+{
+	int	n, m;
+
+	if (baud == 0) {
+		*n_ret = 0;
+		*m_ret = 0;
+		return;
+	}
+     
+	/*
+	 * We scale numbers by 10 so that we get better accuracy
+	 * without having to use floating point.  Here we increment m
+	 * until n is within the valid range.
+	 */
+	n = (SAB_BASE_BAUD * 10) / baud;
+	m = 0;
+	while (n >= 640) {
+		n = n / 2;
+		m++;
+	}
+	n = (n+5) / 10;
+	/*
+	 * We try very hard to avoid speeds with M == 0 since they may
+	 * not work correctly for XTAL frequences above 10 MHz.
+	 */
+	if ((m == 0) && ((n & 1) == 0)) {
+		n = n / 2;
+		m++;
+	}
+	*n_ret = n - 1;
+	*m_ret = m;
+}
+
+/* Internal routine, port->lock is held and local interrupts are disabled.  */
+static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
+				  unsigned int iflag, unsigned int baud,
+				  unsigned int quot)
+{
+	unsigned char dafo;
+	int n, m;
+
+	/* Byte size and parity */
+	switch (cflag & CSIZE) {
+	      case CS5: dafo = SAB82532_DAFO_CHL5; break;
+	      case CS6: dafo = SAB82532_DAFO_CHL6; break;
+	      case CS7: dafo = SAB82532_DAFO_CHL7; break;
+	      case CS8: dafo = SAB82532_DAFO_CHL8; break;
+	      /* Never happens, but GCC is too dumb to figure it out */
+	      default:  dafo = SAB82532_DAFO_CHL5; break;
+	}
+
+	if (cflag & CSTOPB)
+		dafo |= SAB82532_DAFO_STOP;
+
+	if (cflag & PARENB)
+		dafo |= SAB82532_DAFO_PARE;
+
+	if (cflag & PARODD) {
+		dafo |= SAB82532_DAFO_PAR_ODD;
+	} else {
+		dafo |= SAB82532_DAFO_PAR_EVEN;
+	}
+	up->cached_dafo = dafo;
+
+	calc_ebrg(baud, &n, &m);
+
+	up->cached_ebrg = n | (m << 6);
+
+	up->tec_timeout = (10 * 1000000) / baud;
+	up->cec_timeout = up->tec_timeout >> 2;
+
+	/* CTS flow control flags */
+	/* We encode read_status_mask and ignore_status_mask like so:
+	 *
+	 * ---------------------
+	 * | ... | ISR1 | ISR0 |
+	 * ---------------------
+	 *  ..    15   8 7    0
+	 */
+
+	up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
+				     SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
+				     SAB82532_ISR0_CDSC);
+	up->port.read_status_mask |= (SAB82532_ISR1_CSC |
+				      SAB82532_ISR1_ALLS |
+				      SAB82532_ISR1_XPR) << 8;
+	if (iflag & INPCK)
+		up->port.read_status_mask |= (SAB82532_ISR0_PERR |
+					      SAB82532_ISR0_FERR);
+	if (iflag & (IGNBRK | BRKINT | PARMRK))
+		up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
+
+	/*
+	 * Characteres to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
+						SAB82532_ISR0_FERR);
+	if (iflag & IGNBRK) {
+		up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (iflag & IGNPAR)
+			up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
+						SAB82532_ISR0_TCD);
+
+	uart_update_timeout(&up->port, cflag,
+			    (up->port.uartclk / (16 * quot)));
+
+	/* Now schedule a register update when the chip's
+	 * transmitter is idle.
+	 */
+	up->cached_mode |= SAB82532_MODE_RAC;
+	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
+	if (test_bit(SAB82532_XPR, &up->irqflags))
+		sunsab_tx_idle(up);
+}
+
+/* port->lock is not held.  */
+static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
+			       const struct ktermios *old)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+	unsigned int quot = uart_get_divisor(port, baud);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *sunsab_type(struct uart_port *port)
+{
+	struct uart_sunsab_port *up = (void *)port;
+	static char buf[36];
+	
+	sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
+	return buf;
+}
+
+static void sunsab_release_port(struct uart_port *port)
+{
+}
+
+static int sunsab_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sunsab_config_port(struct uart_port *port, int flags)
+{
+}
+
+static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const struct uart_ops sunsab_pops = {
+	.tx_empty	= sunsab_tx_empty,
+	.set_mctrl	= sunsab_set_mctrl,
+	.get_mctrl	= sunsab_get_mctrl,
+	.stop_tx	= sunsab_stop_tx,
+	.start_tx	= sunsab_start_tx,
+	.send_xchar	= sunsab_send_xchar,
+	.stop_rx	= sunsab_stop_rx,
+	.break_ctl	= sunsab_break_ctl,
+	.startup	= sunsab_startup,
+	.shutdown	= sunsab_shutdown,
+	.set_termios	= sunsab_set_termios,
+	.type		= sunsab_type,
+	.release_port	= sunsab_release_port,
+	.request_port	= sunsab_request_port,
+	.config_port	= sunsab_config_port,
+	.verify_port	= sunsab_verify_port,
+};
+
+static struct uart_driver sunsab_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "sunsab",
+	.dev_name		= "ttyS",
+	.major			= TTY_MAJOR,
+};
+
+static struct uart_sunsab_port *sunsab_ports;
+
+#ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
+
+static void sunsab_console_putchar(struct uart_port *port, unsigned char c)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	sunsab_tec_wait(up);
+	writeb(c, &up->regs->w.tic);
+}
+
+static void sunsab_console_write(struct console *con, const char *s, unsigned n)
+{
+	struct uart_sunsab_port *up = &sunsab_ports[con->index];
+	unsigned long flags;
+	int locked = 1;
+
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
+
+	uart_console_write(&up->port, s, n, sunsab_console_putchar);
+	sunsab_tec_wait(up);
+
+	if (locked)
+		spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int sunsab_console_setup(struct console *con, char *options)
+{
+	struct uart_sunsab_port *up = &sunsab_ports[con->index];
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	/*
+	 * The console framework calls us for each and every port
+	 * registered. Defer the console setup until the requested
+	 * port has been properly discovered. A bit of a hack,
+	 * though...
+	 */
+	if (up->port.type != PORT_SUNSAB)
+		return -EINVAL;
+
+	printk("Console: ttyS%d (SAB82532)\n",
+	       (sunsab_reg.minor - 64) + con->index);
+
+	sunserial_console_termios(con, up->port.dev->of_node);
+
+	switch (con->cflag & CBAUD) {
+	case B150: baud = 150; break;
+	case B300: baud = 300; break;
+	case B600: baud = 600; break;
+	case B1200: baud = 1200; break;
+	case B2400: baud = 2400; break;
+	case B4800: baud = 4800; break;
+	default: case B9600: baud = 9600; break;
+	case B19200: baud = 19200; break;
+	case B38400: baud = 38400; break;
+	case B57600: baud = 57600; break;
+	case B115200: baud = 115200; break;
+	case B230400: baud = 230400; break;
+	case B460800: baud = 460800; break;
+	}
+
+	/*
+	 * Temporary fix.
+	 */
+	spin_lock_init(&up->port.lock);
+
+	/*
+	 * Initialize the hardware
+	 */
+	sunsab_startup(&up->port);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
+				SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
+	writeb(up->interrupt_mask0, &up->regs->w.imr0);
+	up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
+				SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
+				SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
+				SAB82532_IMR1_XPR;
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+
+	quot = uart_get_divisor(&up->port, baud);
+	sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
+	sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	
+	return 0;
+}
+
+static struct console sunsab_console = {
+	.name	=	"ttyS",
+	.write	=	sunsab_console_write,
+	.device	=	uart_console_device,
+	.setup	=	sunsab_console_setup,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data	=	&sunsab_reg,
+};
+
+static inline struct console *SUNSAB_CONSOLE(void)
+{
+	return &sunsab_console;
+}
+#else
+#define SUNSAB_CONSOLE()	(NULL)
+#define sunsab_console_init()	do { } while (0)
+#endif
+
+static int sunsab_init_one(struct uart_sunsab_port *up,
+				     struct platform_device *op,
+				     unsigned long offset,
+				     int line)
+{
+	up->port.line = line;
+	up->port.dev = &op->dev;
+
+	up->port.mapbase = op->resource[0].start + offset;
+	up->port.membase = of_ioremap(&op->resource[0], offset,
+				      sizeof(union sab82532_async_regs),
+				      "sab");
+	if (!up->port.membase)
+		return -ENOMEM;
+	up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
+
+	up->port.irq = op->archdata.irqs[0];
+
+	up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
+	up->port.iotype = UPIO_MEM;
+	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSAB_CONSOLE);
+
+	writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
+
+	up->port.ops = &sunsab_pops;
+	up->port.type = PORT_SUNSAB;
+	up->port.uartclk = SAB_BASE_BAUD;
+
+	up->type = readb(&up->regs->r.vstr) & 0x0f;
+	writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
+	writeb(0xff, &up->regs->w.pim);
+	if ((up->port.line & 0x1) == 0) {
+		up->pvr_dsr_bit = (1 << 0);
+		up->pvr_dtr_bit = (1 << 1);
+		up->gis_shift = 2;
+	} else {
+		up->pvr_dsr_bit = (1 << 3);
+		up->pvr_dtr_bit = (1 << 2);
+		up->gis_shift = 0;
+	}
+	up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
+	writeb(up->cached_pvr, &up->regs->w.pvr);
+	up->cached_mode = readb(&up->regs->rw.mode);
+	up->cached_mode |= SAB82532_MODE_FRTS;
+	writeb(up->cached_mode, &up->regs->rw.mode);
+	up->cached_mode |= SAB82532_MODE_RTS;
+	writeb(up->cached_mode, &up->regs->rw.mode);
+
+	up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
+	up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
+
+	return 0;
+}
+
+static int sab_probe(struct platform_device *op)
+{
+	static int inst;
+	struct uart_sunsab_port *up;
+	int err;
+
+	up = &sunsab_ports[inst * 2];
+
+	err = sunsab_init_one(&up[0], op,
+			      0,
+			      (inst * 2) + 0);
+	if (err)
+		goto out;
+
+	err = sunsab_init_one(&up[1], op,
+			      sizeof(union sab82532_async_regs),
+			      (inst * 2) + 1);
+	if (err)
+		goto out1;
+
+	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
+				&sunsab_reg, up[0].port.line,
+				false);
+
+	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
+				&sunsab_reg, up[1].port.line,
+				false);
+
+	err = uart_add_one_port(&sunsab_reg, &up[0].port);
+	if (err)
+		goto out2;
+
+	err = uart_add_one_port(&sunsab_reg, &up[1].port);
+	if (err)
+		goto out3;
+
+	platform_set_drvdata(op, &up[0]);
+
+	inst++;
+
+	return 0;
+
+out3:
+	uart_remove_one_port(&sunsab_reg, &up[0].port);
+out2:
+	of_iounmap(&op->resource[0],
+		   up[1].port.membase,
+		   sizeof(union sab82532_async_regs));
+out1:
+	of_iounmap(&op->resource[0],
+		   up[0].port.membase,
+		   sizeof(union sab82532_async_regs));
+out:
+	return err;
+}
+
+static int sab_remove(struct platform_device *op)
+{
+	struct uart_sunsab_port *up = platform_get_drvdata(op);
+
+	uart_remove_one_port(&sunsab_reg, &up[1].port);
+	uart_remove_one_port(&sunsab_reg, &up[0].port);
+	of_iounmap(&op->resource[0],
+		   up[1].port.membase,
+		   sizeof(union sab82532_async_regs));
+	of_iounmap(&op->resource[0],
+		   up[0].port.membase,
+		   sizeof(union sab82532_async_regs));
+
+	return 0;
+}
+
+static const struct of_device_id sab_match[] = {
+	{
+		.name = "se",
+	},
+	{
+		.name = "serial",
+		.compatible = "sab82532",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, sab_match);
+
+static struct platform_driver sab_driver = {
+	.driver = {
+		.name = "sab",
+		.of_match_table = sab_match,
+	},
+	.probe		= sab_probe,
+	.remove		= sab_remove,
+};
+
+static int __init sunsab_init(void)
+{
+	struct device_node *dp;
+	int err;
+	int num_channels = 0;
+
+	for_each_node_by_name(dp, "se")
+		num_channels += 2;
+	for_each_node_by_name(dp, "serial") {
+		if (of_device_is_compatible(dp, "sab82532"))
+			num_channels += 2;
+	}
+
+	if (num_channels) {
+		sunsab_ports = kcalloc(num_channels,
+				       sizeof(struct uart_sunsab_port),
+				       GFP_KERNEL);
+		if (!sunsab_ports)
+			return -ENOMEM;
+
+		err = sunserial_register_minors(&sunsab_reg, num_channels);
+		if (err) {
+			kfree(sunsab_ports);
+			sunsab_ports = NULL;
+
+			return err;
+		}
+	}
+
+	err = platform_driver_register(&sab_driver);
+	if (err) {
+		kfree(sunsab_ports);
+		sunsab_ports = NULL;
+	}
+
+	return err;
+}
+
+static void __exit sunsab_exit(void)
+{
+	platform_driver_unregister(&sab_driver);
+	if (sunsab_reg.nr) {
+		sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
+	}
+
+	kfree(sunsab_ports);
+	sunsab_ports = NULL;
+}
+
+module_init(sunsab_init);
+module_exit(sunsab_exit);
+
+MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
+MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/sunsab.h b/drivers/tty/serial/sunsab.h
new file mode 100644
index 000000000..1644031aa
--- /dev/null
+++ b/drivers/tty/serial/sunsab.h
@@ -0,0 +1,323 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* sunsab.h: Register Definitions for the Siemens SAB82532 DUSCC
+ *
+ * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
+ */
+
+#ifndef _SUNSAB_H
+#define _SUNSAB_H
+
+struct sab82532_async_rd_regs {
+	u8	rfifo[0x20];	/* Receive FIFO				*/
+	u8	star;		/* Status Register			*/
+	u8	__pad1;
+	u8	mode;		/* Mode Register			*/
+	u8	timr;		/* Timer Register			*/
+	u8	xon;		/* XON Character			*/
+	u8	xoff;		/* XOFF Character			*/
+	u8	tcr;		/* Termination Character Register	*/
+	u8	dafo;		/* Data Format				*/
+	u8	rfc;		/* RFIFO Control Register		*/
+	u8	__pad2;
+	u8	rbcl;		/* Receive Byte Count Low		*/
+	u8	rbch;		/* Receive Byte Count High		*/
+	u8	ccr0;		/* Channel Configuration Register 0	*/
+	u8	ccr1;		/* Channel Configuration Register 1	*/
+	u8	ccr2;		/* Channel Configuration Register 2	*/
+	u8	ccr3;		/* Channel Configuration Register 3	*/
+	u8	__pad3[4];
+	u8	vstr;		/* Version Status Register		*/
+	u8	__pad4[3];
+	u8	gis;		/* Global Interrupt Status		*/
+	u8	ipc;		/* Interrupt Port Configuration		*/
+	u8	isr0;		/* Interrupt Status 0			*/
+	u8	isr1;		/* Interrupt Status 1			*/
+	u8	pvr;		/* Port Value Register			*/
+	u8	pis;		/* Port Interrupt Status		*/
+	u8	pcr;		/* Port Configuration Register		*/
+	u8	ccr4;		/* Channel Configuration Register 4	*/
+};
+
+struct sab82532_async_wr_regs {
+	u8	xfifo[0x20];	/* Transmit FIFO			*/
+	u8	cmdr;		/* Command Register			*/
+	u8	__pad1;
+	u8	mode;
+	u8	timr;
+	u8	xon;
+	u8	xoff;
+	u8	tcr;
+	u8	dafo;
+	u8	rfc;
+	u8	__pad2;
+	u8	xbcl;		/* Transmit Byte Count Low		*/
+	u8	xbch;		/* Transmit Byte Count High		*/
+	u8	ccr0;
+	u8	ccr1;
+	u8	ccr2;
+	u8	ccr3;
+	u8	tsax;		/* Time-Slot Assignment Reg. Transmit	*/
+	u8	tsar;		/* Time-Slot Assignment Reg. Receive	*/
+	u8	xccr;		/* Transmit Channel Capacity Register	*/
+	u8	rccr;		/* Receive Channel Capacity Register	*/
+	u8	bgr;		/* Baud Rate Generator Register		*/
+	u8	tic;		/* Transmit Immediate Character		*/
+	u8	mxn;		/* Mask XON Character			*/
+	u8	mxf;		/* Mask XOFF Character			*/
+	u8	iva;		/* Interrupt Vector Address		*/
+	u8	ipc;
+	u8	imr0;		/* Interrupt Mask Register 0		*/
+	u8	imr1;		/* Interrupt Mask Register 1		*/
+	u8	pvr;
+	u8	pim;		/* Port Interrupt Mask			*/
+	u8	pcr;
+	u8	ccr4;
+};
+
+struct sab82532_async_rw_regs {	/* Read/Write registers			*/
+	u8	__pad1[0x20];
+	u8	__pad2;
+	u8	__pad3;
+	u8	mode;
+	u8	timr;
+	u8	xon;
+	u8	xoff;
+	u8	tcr;
+	u8	dafo;
+	u8	rfc;
+	u8	__pad4;
+	u8	__pad5;
+	u8	__pad6;
+	u8	ccr0;
+	u8	ccr1;
+	u8	ccr2;
+	u8	ccr3;
+	u8	__pad7;
+	u8	__pad8;
+	u8	__pad9;
+	u8	__pad10;
+	u8	__pad11;
+	u8	__pad12;
+	u8	__pad13;
+	u8	__pad14;
+	u8	__pad15;
+	u8	ipc;
+	u8	__pad16;
+	u8	__pad17;
+	u8	pvr;
+	u8	__pad18;
+	u8	pcr;
+	u8	ccr4;
+};
+
+union sab82532_async_regs {
+	__volatile__ struct sab82532_async_rd_regs	r;
+	__volatile__ struct sab82532_async_wr_regs	w;
+	__volatile__ struct sab82532_async_rw_regs	rw;
+};
+
+union sab82532_irq_status {
+	unsigned short			 stat;
+	struct {
+		unsigned char		 isr0;
+		unsigned char		 isr1;
+	} sreg;
+};
+
+/* irqflags bits */
+#define SAB82532_ALLS			0x00000001
+#define SAB82532_XPR			0x00000002
+#define SAB82532_REGS_PENDING		0x00000004
+
+/* RFIFO Status Byte */
+#define SAB82532_RSTAT_PE		0x80
+#define SAB82532_RSTAT_FE		0x40
+#define SAB82532_RSTAT_PARITY		0x01
+
+/* Status Register (STAR) */
+#define SAB82532_STAR_XDOV		0x80
+#define SAB82532_STAR_XFW		0x40
+#define SAB82532_STAR_RFNE		0x20
+#define SAB82532_STAR_FCS		0x10
+#define SAB82532_STAR_TEC		0x08
+#define SAB82532_STAR_CEC		0x04
+#define SAB82532_STAR_CTS		0x02
+
+/* Command Register (CMDR) */
+#define SAB82532_CMDR_RMC		0x80
+#define SAB82532_CMDR_RRES		0x40
+#define SAB82532_CMDR_RFRD		0x20
+#define SAB82532_CMDR_STI		0x10
+#define SAB82532_CMDR_XF		0x08
+#define SAB82532_CMDR_XRES		0x01
+
+/* Mode Register (MODE) */
+#define SAB82532_MODE_FRTS		0x40
+#define SAB82532_MODE_FCTS		0x20
+#define SAB82532_MODE_FLON		0x10
+#define SAB82532_MODE_RAC		0x08
+#define SAB82532_MODE_RTS		0x04
+#define SAB82532_MODE_TRS		0x02
+#define SAB82532_MODE_TLP		0x01
+
+/* Timer Register (TIMR) */
+#define SAB82532_TIMR_CNT_MASK		0xe0
+#define SAB82532_TIMR_VALUE_MASK	0x1f
+
+/* Data Format (DAFO) */
+#define SAB82532_DAFO_XBRK		0x40
+#define SAB82532_DAFO_STOP		0x20
+#define SAB82532_DAFO_PAR_SPACE		0x00
+#define SAB82532_DAFO_PAR_ODD		0x08
+#define SAB82532_DAFO_PAR_EVEN		0x10
+#define SAB82532_DAFO_PAR_MARK		0x18
+#define SAB82532_DAFO_PARE		0x04
+#define SAB82532_DAFO_CHL8		0x00
+#define SAB82532_DAFO_CHL7		0x01
+#define SAB82532_DAFO_CHL6		0x02
+#define SAB82532_DAFO_CHL5		0x03
+
+/* RFIFO Control Register (RFC) */
+#define SAB82532_RFC_DPS		0x40
+#define SAB82532_RFC_DXS		0x20
+#define SAB82532_RFC_RFDF		0x10
+#define SAB82532_RFC_RFTH_1		0x00
+#define SAB82532_RFC_RFTH_4		0x04
+#define SAB82532_RFC_RFTH_16		0x08
+#define SAB82532_RFC_RFTH_32		0x0c
+#define SAB82532_RFC_TCDE		0x01
+
+/* Received Byte Count High (RBCH) */
+#define SAB82532_RBCH_DMA		0x80
+#define SAB82532_RBCH_CAS		0x20
+
+/* Transmit Byte Count High (XBCH) */
+#define SAB82532_XBCH_DMA		0x80
+#define SAB82532_XBCH_CAS		0x20
+#define SAB82532_XBCH_XC		0x10
+
+/* Channel Configuration Register 0 (CCR0) */
+#define SAB82532_CCR0_PU		0x80
+#define SAB82532_CCR0_MCE		0x40
+#define SAB82532_CCR0_SC_NRZ		0x00
+#define SAB82532_CCR0_SC_NRZI		0x08
+#define SAB82532_CCR0_SC_FM0		0x10
+#define SAB82532_CCR0_SC_FM1		0x14
+#define SAB82532_CCR0_SC_MANCH		0x18
+#define SAB82532_CCR0_SM_HDLC		0x00
+#define SAB82532_CCR0_SM_SDLC_LOOP	0x01
+#define SAB82532_CCR0_SM_BISYNC		0x02
+#define SAB82532_CCR0_SM_ASYNC		0x03
+
+/* Channel Configuration Register 1 (CCR1) */
+#define SAB82532_CCR1_ODS		0x10
+#define SAB82532_CCR1_BCR		0x08
+#define SAB82532_CCR1_CM_MASK		0x07
+
+/* Channel Configuration Register 2 (CCR2) */
+#define SAB82532_CCR2_SOC1		0x80
+#define SAB82532_CCR2_SOC0		0x40
+#define SAB82532_CCR2_BR9		0x80
+#define SAB82532_CCR2_BR8		0x40
+#define SAB82532_CCR2_BDF		0x20
+#define SAB82532_CCR2_SSEL		0x10
+#define SAB82532_CCR2_XCS0		0x20
+#define SAB82532_CCR2_RCS0		0x10
+#define SAB82532_CCR2_TOE		0x08
+#define SAB82532_CCR2_RWX		0x04
+#define SAB82532_CCR2_DIV		0x01
+
+/* Channel Configuration Register 3 (CCR3) */
+#define SAB82532_CCR3_PSD		0x01
+
+/* Time Slot Assignment Register Transmit (TSAX) */
+#define SAB82532_TSAX_TSNX_MASK		0xfc
+#define SAB82532_TSAX_XCS2		0x02	/* see also CCR2 */
+#define SAB82532_TSAX_XCS1		0x01
+
+/* Time Slot Assignment Register Receive (TSAR) */
+#define SAB82532_TSAR_TSNR_MASK		0xfc
+#define SAB82532_TSAR_RCS2		0x02	/* see also CCR2 */
+#define SAB82532_TSAR_RCS1		0x01
+
+/* Version Status Register (VSTR) */
+#define SAB82532_VSTR_CD		0x80
+#define SAB82532_VSTR_DPLA		0x40
+#define SAB82532_VSTR_VN_MASK		0x0f
+#define SAB82532_VSTR_VN_1		0x00
+#define SAB82532_VSTR_VN_2		0x01
+#define SAB82532_VSTR_VN_3_2		0x02
+
+/* Global Interrupt Status Register (GIS) */
+#define SAB82532_GIS_PI			0x80
+#define SAB82532_GIS_ISA1		0x08
+#define SAB82532_GIS_ISA0		0x04
+#define SAB82532_GIS_ISB1		0x02
+#define SAB82532_GIS_ISB0		0x01
+
+/* Interrupt Vector Address (IVA) */
+#define SAB82532_IVA_MASK		0xf1
+
+/* Interrupt Port Configuration (IPC) */
+#define SAB82532_IPC_VIS		0x80
+#define SAB82532_IPC_SLA1		0x10
+#define SAB82532_IPC_SLA0		0x08
+#define SAB82532_IPC_CASM		0x04
+#define SAB82532_IPC_IC_OPEN_DRAIN	0x00
+#define SAB82532_IPC_IC_ACT_LOW		0x01
+#define SAB82532_IPC_IC_ACT_HIGH	0x03
+
+/* Interrupt Status Register 0 (ISR0) */
+#define SAB82532_ISR0_TCD		0x80
+#define SAB82532_ISR0_TIME		0x40
+#define SAB82532_ISR0_PERR		0x20
+#define SAB82532_ISR0_FERR		0x10
+#define SAB82532_ISR0_PLLA		0x08
+#define SAB82532_ISR0_CDSC		0x04
+#define SAB82532_ISR0_RFO		0x02
+#define SAB82532_ISR0_RPF		0x01
+
+/* Interrupt Status Register 1 (ISR1) */
+#define SAB82532_ISR1_BRK		0x80
+#define SAB82532_ISR1_BRKT		0x40
+#define SAB82532_ISR1_ALLS		0x20
+#define SAB82532_ISR1_XOFF		0x10
+#define SAB82532_ISR1_TIN		0x08
+#define SAB82532_ISR1_CSC		0x04
+#define SAB82532_ISR1_XON		0x02
+#define SAB82532_ISR1_XPR		0x01
+
+/* Interrupt Mask Register 0 (IMR0) */
+#define SAB82532_IMR0_TCD		0x80
+#define SAB82532_IMR0_TIME		0x40
+#define SAB82532_IMR0_PERR		0x20
+#define SAB82532_IMR0_FERR		0x10
+#define SAB82532_IMR0_PLLA		0x08
+#define SAB82532_IMR0_CDSC		0x04
+#define SAB82532_IMR0_RFO		0x02
+#define SAB82532_IMR0_RPF		0x01
+
+/* Interrupt Mask Register 1 (IMR1) */
+#define SAB82532_IMR1_BRK		0x80
+#define SAB82532_IMR1_BRKT		0x40
+#define SAB82532_IMR1_ALLS		0x20
+#define SAB82532_IMR1_XOFF		0x10
+#define SAB82532_IMR1_TIN		0x08
+#define SAB82532_IMR1_CSC		0x04
+#define SAB82532_IMR1_XON		0x02
+#define SAB82532_IMR1_XPR		0x01
+
+/* Port Interrupt Status Register (PIS) */
+#define SAB82532_PIS_SYNC_B		0x08
+#define SAB82532_PIS_DTR_B		0x04
+#define SAB82532_PIS_DTR_A		0x02
+#define SAB82532_PIS_SYNC_A		0x01
+
+/* Channel Configuration Register 4 (CCR4) */
+#define SAB82532_CCR4_MCK4		0x80
+#define SAB82532_CCR4_EBRG		0x40
+#define SAB82532_CCR4_TST1		0x20
+#define SAB82532_CCR4_ICD		0x10
+
+
+#endif /* !(_SUNSAB_H) */
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
new file mode 100644
index 000000000..58a4342ad
--- /dev/null
+++ b/drivers/tty/serial/sunsu.c
@@ -0,0 +1,1624 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * su.c: Small serial driver for keyboard/mouse interface on sparc32/PCI
+ *
+ * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
+ * Copyright (C) 1998-1999  Pete Zaitcev   (zaitcev@yahoo.com)
+ *
+ * This is mainly a variation of 8250.c, credits go to authors mentioned
+ * therein.  In fact this driver should be merged into the generic 8250.c
+ * infrastructure perhaps using a 8250_sparc.c module.
+ *
+ * Fixed to use tty_get_baud_rate().
+ *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
+ *
+ * Converted to new 2.5.x UART layer.
+ *   David S. Miller (davem@davemloft.net), 2002-Jul-29
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/slab.h>
+#ifdef CONFIG_SERIO
+#include <linux/serio.h>
+#endif
+#include <linux/serial_reg.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <asm/setup.h>
+
+#include <linux/serial_core.h>
+#include <linux/sunserialcore.h>
+
+/* We are on a NS PC87303 clocked with 24.0 MHz, which results
+ * in a UART clock of 1.8462 MHz.
+ */
+#define SU_BASE_BAUD	(1846200 / 16)
+
+enum su_type { SU_PORT_NONE, SU_PORT_MS, SU_PORT_KBD, SU_PORT_PORT };
+static char *su_typev[] = { "su(???)", "su(mouse)", "su(kbd)", "su(serial)" };
+
+struct serial_uart_config {
+	char	*name;
+	int	dfl_xmit_fifo_size;
+	int	flags;
+};
+
+/*
+ * Here we define the default xmit fifo size used for each type of UART.
+ */
+static const struct serial_uart_config uart_config[] = {
+	{ "unknown",	1,	0 },
+	{ "8250",	1,	0 },
+	{ "16450",	1,	0 },
+	{ "16550",	1,	0 },
+	{ "16550A",	16,	UART_CLEAR_FIFO | UART_USE_FIFO },
+	{ "Cirrus",	1, 	0 },
+	{ "ST16650",	1,	UART_CLEAR_FIFO | UART_STARTECH },
+	{ "ST16650V2",	32,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
+	{ "TI16750",	64,	UART_CLEAR_FIFO | UART_USE_FIFO },
+	{ "Startech",	1,	0 },
+	{ "16C950/954",	128,	UART_CLEAR_FIFO | UART_USE_FIFO },
+	{ "ST16654",	64,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
+	{ "XR16850",	128,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
+	{ "RSA",	2048,	UART_CLEAR_FIFO | UART_USE_FIFO }
+};
+
+struct uart_sunsu_port {
+	struct uart_port	port;
+	unsigned char		acr;
+	unsigned char		ier;
+	unsigned short		rev;
+	unsigned char		lcr;
+	unsigned int		lsr_break_flag;
+	unsigned int		cflag;
+
+	/* Probing information.  */
+	enum su_type		su_type;
+	unsigned int		type_probed;	/* XXX Stupid */
+	unsigned long		reg_size;
+
+#ifdef CONFIG_SERIO
+	struct serio		serio;
+	int			serio_open;
+#endif
+};
+
+static unsigned int serial_in(struct uart_sunsu_port *up, int offset)
+{
+	offset <<= up->port.regshift;
+
+	switch (up->port.iotype) {
+	case UPIO_HUB6:
+		outb(up->port.hub6 - 1 + offset, up->port.iobase);
+		return inb(up->port.iobase + 1);
+
+	case UPIO_MEM:
+		return readb(up->port.membase + offset);
+
+	default:
+		return inb(up->port.iobase + offset);
+	}
+}
+
+static void serial_out(struct uart_sunsu_port *up, int offset, int value)
+{
+#ifndef CONFIG_SPARC64
+	/*
+	 * MrCoffee has weird schematics: IRQ4 & P10(?) pins of SuperIO are
+	 * connected with a gate then go to SlavIO. When IRQ4 goes tristated
+	 * gate outputs a logical one. Since we use level triggered interrupts
+	 * we have lockup and watchdog reset. We cannot mask IRQ because
+	 * keyboard shares IRQ with us (Word has it as Bob Smelik's design).
+	 * This problem is similar to what Alpha people suffer, see
+	 * 8250_alpha.c.
+	 */
+	if (offset == UART_MCR)
+		value |= UART_MCR_OUT2;
+#endif
+	offset <<= up->port.regshift;
+
+	switch (up->port.iotype) {
+	case UPIO_HUB6:
+		outb(up->port.hub6 - 1 + offset, up->port.iobase);
+		outb(value, up->port.iobase + 1);
+		break;
+
+	case UPIO_MEM:
+		writeb(value, up->port.membase + offset);
+		break;
+
+	default:
+		outb(value, up->port.iobase + offset);
+	}
+}
+
+/*
+ * We used to support using pause I/O for certain machines.  We
+ * haven't supported this for a while, but just in case it's badly
+ * needed for certain old 386 machines, I've left these #define's
+ * in....
+ */
+#define serial_inp(up, offset)		serial_in(up, offset)
+#define serial_outp(up, offset, value)	serial_out(up, offset, value)
+
+
+/*
+ * For the 16C950
+ */
+static void serial_icr_write(struct uart_sunsu_port *up, int offset, int value)
+{
+	serial_out(up, UART_SCR, offset);
+	serial_out(up, UART_ICR, value);
+}
+
+#if 0 /* Unused currently */
+static unsigned int serial_icr_read(struct uart_sunsu_port *up, int offset)
+{
+	unsigned int value;
+
+	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
+	serial_out(up, UART_SCR, offset);
+	value = serial_in(up, UART_ICR);
+	serial_icr_write(up, UART_ACR, up->acr);
+
+	return value;
+}
+#endif
+
+#ifdef CONFIG_SERIAL_8250_RSA
+/*
+ * Attempts to turn on the RSA FIFO.  Returns zero on failure.
+ * We set the port uart clock rate if we succeed.
+ */
+static int __enable_rsa(struct uart_sunsu_port *up)
+{
+	unsigned char mode;
+	int result;
+
+	mode = serial_inp(up, UART_RSA_MSR);
+	result = mode & UART_RSA_MSR_FIFO;
+
+	if (!result) {
+		serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
+		mode = serial_inp(up, UART_RSA_MSR);
+		result = mode & UART_RSA_MSR_FIFO;
+	}
+
+	if (result)
+		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
+
+	return result;
+}
+
+static void enable_rsa(struct uart_sunsu_port *up)
+{
+	if (up->port.type == PORT_RSA) {
+		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
+			spin_lock_irq(&up->port.lock);
+			__enable_rsa(up);
+			spin_unlock_irq(&up->port.lock);
+		}
+		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
+			serial_outp(up, UART_RSA_FRR, 0);
+	}
+}
+
+/*
+ * Attempts to turn off the RSA FIFO.  Returns zero on failure.
+ * It is unknown why interrupts were disabled in here.  However,
+ * the caller is expected to preserve this behaviour by grabbing
+ * the spinlock before calling this function.
+ */
+static void disable_rsa(struct uart_sunsu_port *up)
+{
+	unsigned char mode;
+	int result;
+
+	if (up->port.type == PORT_RSA &&
+	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
+		spin_lock_irq(&up->port.lock);
+
+		mode = serial_inp(up, UART_RSA_MSR);
+		result = !(mode & UART_RSA_MSR_FIFO);
+
+		if (!result) {
+			serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
+			mode = serial_inp(up, UART_RSA_MSR);
+			result = !(mode & UART_RSA_MSR_FIFO);
+		}
+
+		if (result)
+			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
+		spin_unlock_irq(&up->port.lock);
+	}
+}
+#endif /* CONFIG_SERIAL_8250_RSA */
+
+static inline void __stop_tx(struct uart_sunsu_port *p)
+{
+	if (p->ier & UART_IER_THRI) {
+		p->ier &= ~UART_IER_THRI;
+		serial_out(p, UART_IER, p->ier);
+	}
+}
+
+static void sunsu_stop_tx(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+
+	__stop_tx(up);
+
+	/*
+	 * We really want to stop the transmitter from sending.
+	 */
+	if (up->port.type == PORT_16C950) {
+		up->acr |= UART_ACR_TXDIS;
+		serial_icr_write(up, UART_ACR, up->acr);
+	}
+}
+
+static void sunsu_start_tx(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+
+	if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+
+	/*
+	 * Re-enable the transmitter if we disabled it.
+	 */
+	if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
+		up->acr &= ~UART_ACR_TXDIS;
+		serial_icr_write(up, UART_ACR, up->acr);
+	}
+}
+
+static void sunsu_stop_rx(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+
+	up->ier &= ~UART_IER_RLSI;
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void sunsu_enable_ms(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void
+receive_chars(struct uart_sunsu_port *up, unsigned char *status)
+{
+	struct tty_port *port = &up->port.state->port;
+	unsigned char ch, flag;
+	int max_count = 256;
+	int saw_console_brk = 0;
+
+	do {
+		ch = serial_inp(up, UART_RX);
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
+				       UART_LSR_FE | UART_LSR_OE))) {
+			/*
+			 * For statistics only
+			 */
+			if (*status & UART_LSR_BI) {
+				*status &= ~(UART_LSR_FE | UART_LSR_PE);
+				up->port.icount.brk++;
+				if (up->port.cons != NULL &&
+				    up->port.line == up->port.cons->index)
+					saw_console_brk = 1;
+				/*
+				 * We do the SysRQ and SAK checking
+				 * here because otherwise the break
+				 * may get masked by ignore_status_mask
+				 * or read_status_mask.
+				 */
+				if (uart_handle_break(&up->port))
+					goto ignore_char;
+			} else if (*status & UART_LSR_PE)
+				up->port.icount.parity++;
+			else if (*status & UART_LSR_FE)
+				up->port.icount.frame++;
+			if (*status & UART_LSR_OE)
+				up->port.icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ingored.
+			 */
+			*status &= up->port.read_status_mask;
+
+			if (up->port.cons != NULL &&
+			    up->port.line == up->port.cons->index) {
+				/* Recover the break flag from console xmit */
+				*status |= up->lsr_break_flag;
+				up->lsr_break_flag = 0;
+			}
+
+			if (*status & UART_LSR_BI) {
+				flag = TTY_BREAK;
+			} else if (*status & UART_LSR_PE)
+				flag = TTY_PARITY;
+			else if (*status & UART_LSR_FE)
+				flag = TTY_FRAME;
+		}
+		if (uart_handle_sysrq_char(&up->port, ch))
+			goto ignore_char;
+		if ((*status & up->port.ignore_status_mask) == 0)
+			tty_insert_flip_char(port, ch, flag);
+		if (*status & UART_LSR_OE)
+			/*
+			 * Overrun is special, since it's reported
+			 * immediately, and doesn't affect the current
+			 * character.
+			 */
+			 tty_insert_flip_char(port, 0, TTY_OVERRUN);
+	ignore_char:
+		*status = serial_inp(up, UART_LSR);
+	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
+
+	if (saw_console_brk)
+		sun_do_break();
+}
+
+static void transmit_chars(struct uart_sunsu_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int count;
+
+	if (up->port.x_char) {
+		serial_outp(up, UART_TX, up->port.x_char);
+		up->port.icount.tx++;
+		up->port.x_char = 0;
+		return;
+	}
+	if (uart_tx_stopped(&up->port)) {
+		sunsu_stop_tx(&up->port);
+		return;
+	}
+	if (uart_circ_empty(xmit)) {
+		__stop_tx(up);
+		return;
+	}
+
+	count = up->port.fifosize;
+	do {
+		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		uart_xmit_advance(&up->port, 1);
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (uart_circ_empty(xmit))
+		__stop_tx(up);
+}
+
+static void check_modem_status(struct uart_sunsu_port *up)
+{
+	int status;
+
+	status = serial_in(up, UART_MSR);
+
+	if ((status & UART_MSR_ANY_DELTA) == 0)
+		return;
+
+	if (status & UART_MSR_TERI)
+		up->port.icount.rng++;
+	if (status & UART_MSR_DDSR)
+		up->port.icount.dsr++;
+	if (status & UART_MSR_DDCD)
+		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
+	if (status & UART_MSR_DCTS)
+		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
+
+	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+}
+
+static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id)
+{
+	struct uart_sunsu_port *up = dev_id;
+	unsigned long flags;
+	unsigned char status;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	do {
+		status = serial_inp(up, UART_LSR);
+		if (status & UART_LSR_DR)
+			receive_chars(up, &status);
+		check_modem_status(up);
+		if (status & UART_LSR_THRE)
+			transmit_chars(up);
+
+		tty_flip_buffer_push(&up->port.state->port);
+
+	} while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT));
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+/* Separate interrupt handling path for keyboard/mouse ports.  */
+
+static void
+sunsu_change_speed(struct uart_port *port, unsigned int cflag,
+		   unsigned int iflag, unsigned int quot);
+
+static void sunsu_change_mouse_baud(struct uart_sunsu_port *up)
+{
+	unsigned int cur_cflag = up->cflag;
+	int quot, new_baud;
+
+	up->cflag &= ~CBAUD;
+	up->cflag |= suncore_mouse_baud_cflag_next(cur_cflag, &new_baud);
+
+	quot = up->port.uartclk / (16 * new_baud);
+
+	sunsu_change_speed(&up->port, up->cflag, 0, quot);
+}
+
+static void receive_kbd_ms_chars(struct uart_sunsu_port *up, int is_break)
+{
+	do {
+		unsigned char ch = serial_inp(up, UART_RX);
+
+		/* Stop-A is handled by drivers/char/keyboard.c now. */
+		if (up->su_type == SU_PORT_KBD) {
+#ifdef CONFIG_SERIO
+			serio_interrupt(&up->serio, ch, 0);
+#endif
+		} else if (up->su_type == SU_PORT_MS) {
+			int ret = suncore_mouse_baud_detection(ch, is_break);
+
+			switch (ret) {
+			case 2:
+				sunsu_change_mouse_baud(up);
+				fallthrough;
+			case 1:
+				break;
+
+			case 0:
+#ifdef CONFIG_SERIO
+				serio_interrupt(&up->serio, ch, 0);
+#endif
+				break;
+			}
+		}
+	} while (serial_in(up, UART_LSR) & UART_LSR_DR);
+}
+
+static irqreturn_t sunsu_kbd_ms_interrupt(int irq, void *dev_id)
+{
+	struct uart_sunsu_port *up = dev_id;
+
+	if (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT)) {
+		unsigned char status = serial_inp(up, UART_LSR);
+
+		if ((status & UART_LSR_DR) || (status & UART_LSR_BI))
+			receive_kbd_ms_chars(up, (status & UART_LSR_BI) != 0);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int sunsu_tx_empty(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned long flags;
+	unsigned int ret;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return ret;
+}
+
+static unsigned int sunsu_get_mctrl(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned char status;
+	unsigned int ret;
+
+	status = serial_in(up, UART_MSR);
+
+	ret = 0;
+	if (status & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+	if (status & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+	if (status & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+	if (status & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void sunsu_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned char mcr = 0;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (mctrl & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	serial_out(up, UART_MCR, mcr);
+}
+
+static void sunsu_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_out(up, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int sunsu_startup(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned long flags;
+	int retval;
+
+	if (up->port.type == PORT_16C950) {
+		/* Wake up and initialize UART */
+		up->acr = 0;
+		serial_outp(up, UART_LCR, 0xBF);
+		serial_outp(up, UART_EFR, UART_EFR_ECB);
+		serial_outp(up, UART_IER, 0);
+		serial_outp(up, UART_LCR, 0);
+		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
+		serial_outp(up, UART_LCR, 0xBF);
+		serial_outp(up, UART_EFR, UART_EFR_ECB);
+		serial_outp(up, UART_LCR, 0);
+	}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * If this is an RSA port, see if we can kick it up to the
+	 * higher speed clock.
+	 */
+	enable_rsa(up);
+#endif
+
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	if (uart_config[up->port.type].flags & UART_CLEAR_FIFO) {
+		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+		serial_outp(up, UART_FCR, 0);
+	}
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) serial_inp(up, UART_LSR);
+	(void) serial_inp(up, UART_RX);
+	(void) serial_inp(up, UART_IIR);
+	(void) serial_inp(up, UART_MSR);
+
+	/*
+	 * At this point, there's no way the LSR could still be 0xff;
+	 * if it is, then bail out, because there's likely no UART
+	 * here.
+	 */
+	if (!(up->port.flags & UPF_BUGGY_UART) &&
+	    (serial_inp(up, UART_LSR) == 0xff)) {
+		printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
+		return -ENODEV;
+	}
+
+	if (up->su_type != SU_PORT_PORT) {
+		retval = request_irq(up->port.irq, sunsu_kbd_ms_interrupt,
+				     IRQF_SHARED, su_typev[up->su_type], up);
+	} else {
+		retval = request_irq(up->port.irq, sunsu_serial_interrupt,
+				     IRQF_SHARED, su_typev[up->su_type], up);
+	}
+	if (retval) {
+		printk("su: Cannot register IRQ %d\n", up->port.irq);
+		return retval;
+	}
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_outp(up, UART_LCR, UART_LCR_WLEN8);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->port.mctrl |= TIOCM_OUT2;
+
+	sunsu_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/*
+	 * Finally, enable interrupts.  Note: Modem status interrupts
+	 * are set via set_termios(), which will be occurring imminently
+	 * anyway, so we don't enable them here.
+	 */
+	up->ier = UART_IER_RLSI | UART_IER_RDI;
+	serial_outp(up, UART_IER, up->ier);
+
+	if (up->port.flags & UPF_FOURPORT) {
+		unsigned int icp;
+		/*
+		 * Enable interrupts on the AST Fourport board
+		 */
+		icp = (up->port.iobase & 0xfe0) | 0x01f;
+		outb_p(0x80, icp);
+		(void) inb_p(icp);
+	}
+
+	/*
+	 * And clear the interrupt registers again for luck.
+	 */
+	(void) serial_inp(up, UART_LSR);
+	(void) serial_inp(up, UART_RX);
+	(void) serial_inp(up, UART_IIR);
+	(void) serial_inp(up, UART_MSR);
+
+	return 0;
+}
+
+static void sunsu_shutdown(struct uart_port *port)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned long flags;
+
+	/*
+	 * Disable interrupts from this port
+	 */
+	up->ier = 0;
+	serial_outp(up, UART_IER, 0);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (up->port.flags & UPF_FOURPORT) {
+		/* reset interrupts on the AST Fourport board */
+		inb((up->port.iobase & 0xfe0) | 0x1f);
+		up->port.mctrl |= TIOCM_OUT1;
+	} else
+		up->port.mctrl &= ~TIOCM_OUT2;
+
+	sunsu_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+				  UART_FCR_CLEAR_RCVR |
+				  UART_FCR_CLEAR_XMIT);
+	serial_outp(up, UART_FCR, 0);
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * Reset the RSA board back to 115kbps compat mode.
+	 */
+	disable_rsa(up);
+#endif
+
+	/*
+	 * Read data port to reset things.
+	 */
+	(void) serial_in(up, UART_RX);
+
+	free_irq(up->port.irq, up);
+}
+
+static void
+sunsu_change_speed(struct uart_port *port, unsigned int cflag,
+		   unsigned int iflag, unsigned int quot)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+	unsigned char cval, fcr = 0;
+	unsigned long flags;
+
+	switch (cflag & CSIZE) {
+	case CS5:
+		cval = 0x00;
+		break;
+	case CS6:
+		cval = 0x01;
+		break;
+	case CS7:
+		cval = 0x02;
+		break;
+	default:
+	case CS8:
+		cval = 0x03;
+		break;
+	}
+
+	if (cflag & CSTOPB)
+		cval |= 0x04;
+	if (cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	if (cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+
+	/*
+	 * Work around a bug in the Oxford Semiconductor 952 rev B
+	 * chip which causes it to seriously miscalculate baud rates
+	 * when DLL is 0.
+	 */
+	if ((quot & 0xff) == 0 && up->port.type == PORT_16C950 &&
+	    up->rev == 0x5201)
+		quot ++;
+
+	if (uart_config[up->port.type].flags & UART_USE_FIFO) {
+		if ((up->port.uartclk / quot) < (2400 * 16))
+			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
+#ifdef CONFIG_SERIAL_8250_RSA
+		else if (up->port.type == PORT_RSA)
+			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_14;
+#endif
+		else
+			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_8;
+	}
+	if (up->port.type == PORT_16750)
+		fcr |= UART_FCR7_64BYTE;
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, cflag, (port->uartclk / (16 * quot)));
+
+	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (iflag & INPCK)
+		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (iflag & (IGNBRK | BRKINT | PARMRK))
+		up->port.read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characteres to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (iflag & IGNBRK) {
+		up->port.ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (iflag & IGNPAR)
+			up->port.ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * CTS flow control flag and modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (UART_ENABLE_MS(&up->port, cflag))
+		up->ier |= UART_IER_MSI;
+
+	serial_out(up, UART_IER, up->ier);
+
+	if (uart_config[up->port.type].flags & UART_STARTECH) {
+		serial_outp(up, UART_LCR, 0xBF);
+		serial_outp(up, UART_EFR, cflag & CRTSCTS ? UART_EFR_CTS :0);
+	}
+	serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
+	serial_outp(up, UART_DLL, quot & 0xff);		/* LS of divisor */
+	serial_outp(up, UART_DLM, quot >> 8);		/* MS of divisor */
+	if (up->port.type == PORT_16750)
+		serial_outp(up, UART_FCR, fcr);		/* set fcr */
+	serial_outp(up, UART_LCR, cval);		/* reset DLAB */
+	up->lcr = cval;					/* Save LCR */
+	if (up->port.type != PORT_16750) {
+		if (fcr & UART_FCR_ENABLE_FIFO) {
+			/* emulated UARTs (Lucent Venus 167x) need two steps */
+			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+		}
+		serial_outp(up, UART_FCR, fcr);		/* set fcr */
+	}
+
+	up->cflag = cflag;
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void
+sunsu_set_termios(struct uart_port *port, struct ktermios *termios,
+		  const struct ktermios *old)
+{
+	unsigned int baud, quot;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
+	quot = uart_get_divisor(port, baud);
+
+	sunsu_change_speed(port, termios->c_cflag, termios->c_iflag, quot);
+}
+
+static void sunsu_release_port(struct uart_port *port)
+{
+}
+
+static int sunsu_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sunsu_config_port(struct uart_port *port, int flags)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+
+	if (flags & UART_CONFIG_TYPE) {
+		/*
+		 * We are supposed to call autoconfig here, but this requires
+		 * splitting all the OBP probing crap from the UART probing.
+		 * We'll do it when we kill sunsu.c altogether.
+		 */
+		port->type = up->type_probed;	/* XXX */
+	}
+}
+
+static int
+sunsu_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const char *
+sunsu_type(struct uart_port *port)
+{
+	int type = port->type;
+
+	if (type >= ARRAY_SIZE(uart_config))
+		type = 0;
+	return uart_config[type].name;
+}
+
+static const struct uart_ops sunsu_pops = {
+	.tx_empty	= sunsu_tx_empty,
+	.set_mctrl	= sunsu_set_mctrl,
+	.get_mctrl	= sunsu_get_mctrl,
+	.stop_tx	= sunsu_stop_tx,
+	.start_tx	= sunsu_start_tx,
+	.stop_rx	= sunsu_stop_rx,
+	.enable_ms	= sunsu_enable_ms,
+	.break_ctl	= sunsu_break_ctl,
+	.startup	= sunsu_startup,
+	.shutdown	= sunsu_shutdown,
+	.set_termios	= sunsu_set_termios,
+	.type		= sunsu_type,
+	.release_port	= sunsu_release_port,
+	.request_port	= sunsu_request_port,
+	.config_port	= sunsu_config_port,
+	.verify_port	= sunsu_verify_port,
+};
+
+#define UART_NR	4
+
+static struct uart_sunsu_port sunsu_ports[UART_NR];
+static int nr_inst; /* Number of already registered ports */
+
+#ifdef CONFIG_SERIO
+
+static DEFINE_SPINLOCK(sunsu_serio_lock);
+
+static int sunsu_serio_write(struct serio *serio, unsigned char ch)
+{
+	struct uart_sunsu_port *up = serio->port_data;
+	unsigned long flags;
+	int lsr;
+
+	spin_lock_irqsave(&sunsu_serio_lock, flags);
+
+	do {
+		lsr = serial_in(up, UART_LSR);
+	} while (!(lsr & UART_LSR_THRE));
+
+	/* Send the character out. */
+	serial_out(up, UART_TX, ch);
+
+	spin_unlock_irqrestore(&sunsu_serio_lock, flags);
+
+	return 0;
+}
+
+static int sunsu_serio_open(struct serio *serio)
+{
+	struct uart_sunsu_port *up = serio->port_data;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&sunsu_serio_lock, flags);
+	if (!up->serio_open) {
+		up->serio_open = 1;
+		ret = 0;
+	} else
+		ret = -EBUSY;
+	spin_unlock_irqrestore(&sunsu_serio_lock, flags);
+
+	return ret;
+}
+
+static void sunsu_serio_close(struct serio *serio)
+{
+	struct uart_sunsu_port *up = serio->port_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sunsu_serio_lock, flags);
+	up->serio_open = 0;
+	spin_unlock_irqrestore(&sunsu_serio_lock, flags);
+}
+
+#endif /* CONFIG_SERIO */
+
+static void sunsu_autoconfig(struct uart_sunsu_port *up)
+{
+	unsigned char status1, status2, scratch, scratch2, scratch3;
+	unsigned char save_lcr, save_mcr;
+	unsigned long flags;
+
+	if (up->su_type == SU_PORT_NONE)
+		return;
+
+	up->type_probed = PORT_UNKNOWN;
+	up->port.iotype = UPIO_MEM;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	if (!(up->port.flags & UPF_BUGGY_UART)) {
+		/*
+		 * Do a simple existence test first; if we fail this, there's
+		 * no point trying anything else.
+		 *
+		 * 0x80 is used as a nonsense port to prevent against false
+		 * positives due to ISA bus float.  The assumption is that
+		 * 0x80 is a non-existent port; which should be safe since
+		 * include/asm/io.h also makes this assumption.
+		 */
+		scratch = serial_inp(up, UART_IER);
+		serial_outp(up, UART_IER, 0);
+#ifdef __i386__
+		outb(0xff, 0x080);
+#endif
+		scratch2 = serial_inp(up, UART_IER);
+		serial_outp(up, UART_IER, 0x0f);
+#ifdef __i386__
+		outb(0, 0x080);
+#endif
+		scratch3 = serial_inp(up, UART_IER);
+		serial_outp(up, UART_IER, scratch);
+		if (scratch2 != 0 || scratch3 != 0x0F)
+			goto out;	/* We failed; there's nothing here */
+	}
+
+	save_mcr = serial_in(up, UART_MCR);
+	save_lcr = serial_in(up, UART_LCR);
+
+	/* 
+	 * Check to see if a UART is really there.  Certain broken
+	 * internal modems based on the Rockwell chipset fail this
+	 * test, because they apparently don't implement the loopback
+	 * test mode.  So this test is skipped on the COM 1 through
+	 * COM 4 ports.  This *should* be safe, since no board
+	 * manufacturer would be stupid enough to design a board
+	 * that conflicts with COM 1-4 --- we hope!
+	 */
+	if (!(up->port.flags & UPF_SKIP_TEST)) {
+		serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
+		status1 = serial_inp(up, UART_MSR) & 0xF0;
+		serial_outp(up, UART_MCR, save_mcr);
+		if (status1 != 0x90)
+			goto out;	/* We failed loopback test */
+	}
+	serial_outp(up, UART_LCR, 0xBF);	/* set up for StarTech test */
+	serial_outp(up, UART_EFR, 0);		/* EFR is the same as FCR */
+	serial_outp(up, UART_LCR, 0);
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	scratch = serial_in(up, UART_IIR) >> 6;
+	switch (scratch) {
+		case 0:
+			up->port.type = PORT_16450;
+			break;
+		case 1:
+			up->port.type = PORT_UNKNOWN;
+			break;
+		case 2:
+			up->port.type = PORT_16550;
+			break;
+		case 3:
+			up->port.type = PORT_16550A;
+			break;
+	}
+	if (up->port.type == PORT_16550A) {
+		/* Check for Startech UART's */
+		serial_outp(up, UART_LCR, UART_LCR_DLAB);
+		if (serial_in(up, UART_EFR) == 0) {
+			up->port.type = PORT_16650;
+		} else {
+			serial_outp(up, UART_LCR, 0xBF);
+			if (serial_in(up, UART_EFR) == 0)
+				up->port.type = PORT_16650V2;
+		}
+	}
+	if (up->port.type == PORT_16550A) {
+		/* Check for TI 16750 */
+		serial_outp(up, UART_LCR, save_lcr | UART_LCR_DLAB);
+		serial_outp(up, UART_FCR,
+			    UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+		scratch = serial_in(up, UART_IIR) >> 5;
+		if (scratch == 7) {
+			/*
+			 * If this is a 16750, and not a cheap UART
+			 * clone, then it should only go into 64 byte
+			 * mode if the UART_FCR7_64BYTE bit was set
+			 * while UART_LCR_DLAB was latched.
+			 */
+ 			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+			serial_outp(up, UART_LCR, 0);
+			serial_outp(up, UART_FCR,
+				    UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+			scratch = serial_in(up, UART_IIR) >> 5;
+			if (scratch == 6)
+				up->port.type = PORT_16750;
+		}
+		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	}
+	serial_outp(up, UART_LCR, save_lcr);
+	if (up->port.type == PORT_16450) {
+		scratch = serial_in(up, UART_SCR);
+		serial_outp(up, UART_SCR, 0xa5);
+		status1 = serial_in(up, UART_SCR);
+		serial_outp(up, UART_SCR, 0x5a);
+		status2 = serial_in(up, UART_SCR);
+		serial_outp(up, UART_SCR, scratch);
+
+		if ((status1 != 0xa5) || (status2 != 0x5a))
+			up->port.type = PORT_8250;
+	}
+
+	up->port.fifosize = uart_config[up->port.type].dfl_xmit_fifo_size;
+
+	if (up->port.type == PORT_UNKNOWN)
+		goto out;
+	up->type_probed = up->port.type;	/* XXX */
+
+	/*
+	 * Reset the UART.
+	 */
+#ifdef CONFIG_SERIAL_8250_RSA
+	if (up->port.type == PORT_RSA)
+		serial_outp(up, UART_RSA_FRR, 0);
+#endif
+	serial_outp(up, UART_MCR, save_mcr);
+	serial_outp(up, UART_FCR, (UART_FCR_ENABLE_FIFO |
+				     UART_FCR_CLEAR_RCVR |
+				     UART_FCR_CLEAR_XMIT));
+	serial_outp(up, UART_FCR, 0);
+	(void)serial_in(up, UART_RX);
+	serial_outp(up, UART_IER, 0);
+
+out:
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static struct uart_driver sunsu_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "sunsu",
+	.dev_name		= "ttyS",
+	.major			= TTY_MAJOR,
+};
+
+static int sunsu_kbd_ms_init(struct uart_sunsu_port *up)
+{
+	int quot, baud;
+#ifdef CONFIG_SERIO
+	struct serio *serio;
+#endif
+
+	if (up->su_type == SU_PORT_KBD) {
+		up->cflag = B1200 | CS8 | CLOCAL | CREAD;
+		baud = 1200;
+	} else {
+		up->cflag = B4800 | CS8 | CLOCAL | CREAD;
+		baud = 4800;
+	}
+	quot = up->port.uartclk / (16 * baud);
+
+	sunsu_autoconfig(up);
+	if (up->port.type == PORT_UNKNOWN)
+		return -ENODEV;
+
+	printk("%pOF: %s port at %llx, irq %u\n",
+	       up->port.dev->of_node,
+	       (up->su_type == SU_PORT_KBD) ? "Keyboard" : "Mouse",
+	       (unsigned long long) up->port.mapbase,
+	       up->port.irq);
+
+#ifdef CONFIG_SERIO
+	serio = &up->serio;
+	serio->port_data = up;
+
+	serio->id.type = SERIO_RS232;
+	if (up->su_type == SU_PORT_KBD) {
+		serio->id.proto = SERIO_SUNKBD;
+		strscpy(serio->name, "sukbd", sizeof(serio->name));
+	} else {
+		serio->id.proto = SERIO_SUN;
+		serio->id.extra = 1;
+		strscpy(serio->name, "sums", sizeof(serio->name));
+	}
+	strscpy(serio->phys,
+		(!(up->port.line & 1) ? "su/serio0" : "su/serio1"),
+		sizeof(serio->phys));
+
+	serio->write = sunsu_serio_write;
+	serio->open = sunsu_serio_open;
+	serio->close = sunsu_serio_close;
+	serio->dev.parent = up->port.dev;
+
+	serio_register_port(serio);
+#endif
+
+	sunsu_change_speed(&up->port, up->cflag, 0, quot);
+
+	sunsu_startup(&up->port);
+	return 0;
+}
+
+/*
+ * ------------------------------------------------------------
+ * Serial console driver
+ * ------------------------------------------------------------
+ */
+
+#ifdef CONFIG_SERIAL_SUNSU_CONSOLE
+
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_sunsu_port *up)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	do {
+		status = serial_in(up, UART_LSR);
+
+		if (status & UART_LSR_BI)
+			up->lsr_break_flag = UART_LSR_BI;
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (!uart_lsr_tx_empty(status));
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		while (--tmout &&
+		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
+			udelay(1);
+	}
+}
+
+static void sunsu_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_sunsu_port *up =
+		container_of(port, struct uart_sunsu_port, port);
+
+	wait_for_xmitr(up);
+	serial_out(up, UART_TX, ch);
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ */
+static void sunsu_console_write(struct console *co, const char *s,
+				unsigned int count)
+{
+	struct uart_sunsu_port *up = &sunsu_ports[co->index];
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 *	First save the UER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, 0);
+
+	uart_console_write(&up->port, s, count, sunsu_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, UART_IER, ier);
+
+	if (locked)
+		spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/*
+ *	Setup initial baud/bits/parity. We do two things here:
+ *	- construct a cflag setting for the first su_open()
+ *	- initialize the serial port
+ *	Return non-zero if we didn't find a serial port.
+ */
+static int __init sunsu_console_setup(struct console *co, char *options)
+{
+	static struct ktermios dummy;
+	struct ktermios termios;
+	struct uart_port *port;
+
+	printk("Console: ttyS%d (SU)\n",
+	       (sunsu_reg.minor - 64) + co->index);
+
+	if (co->index > nr_inst)
+		return -ENODEV;
+	port = &sunsu_ports[co->index].port;
+
+	/*
+	 * Temporary fix.
+	 */
+	spin_lock_init(&port->lock);
+
+	/* Get firmware console settings.  */
+	sunserial_console_termios(co, port->dev->of_node);
+
+	memset(&termios, 0, sizeof(struct ktermios));
+	termios.c_cflag = co->cflag;
+	port->mctrl |= TIOCM_DTR;
+	port->ops->set_termios(port, &termios, &dummy);
+
+	return 0;
+}
+
+static struct console sunsu_console = {
+	.name	=	"ttyS",
+	.write	=	sunsu_console_write,
+	.device	=	uart_console_device,
+	.setup	=	sunsu_console_setup,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data	=	&sunsu_reg,
+};
+
+/*
+ *	Register console.
+ */
+
+static inline struct console *SUNSU_CONSOLE(void)
+{
+	return &sunsu_console;
+}
+#else
+#define SUNSU_CONSOLE()			(NULL)
+#define sunsu_serial_console_init()	do { } while (0)
+#endif
+
+static enum su_type su_get_type(struct device_node *dp)
+{
+	struct device_node *ap = of_find_node_by_path("/aliases");
+	enum su_type rc = SU_PORT_PORT;
+
+	if (ap) {
+		const char *keyb = of_get_property(ap, "keyboard", NULL);
+		const char *ms = of_get_property(ap, "mouse", NULL);
+		struct device_node *match;
+
+		if (keyb) {
+			match = of_find_node_by_path(keyb);
+
+			/*
+			 * The pointer is used as an identifier not
+			 * as a pointer, we can drop the refcount on
+			 * the of__node immediately after getting it.
+			 */
+			of_node_put(match);
+
+			if (dp == match) {
+				rc = SU_PORT_KBD;
+				goto out;
+			}
+		}
+		if (ms) {
+			match = of_find_node_by_path(ms);
+
+			of_node_put(match);
+
+			if (dp == match) {
+				rc = SU_PORT_MS;
+				goto out;
+			}
+		}
+	}
+
+out:
+	of_node_put(ap);
+	return rc;
+}
+
+static int su_probe(struct platform_device *op)
+{
+	struct device_node *dp = op->dev.of_node;
+	struct uart_sunsu_port *up;
+	struct resource *rp;
+	enum su_type type;
+	bool ignore_line;
+	int err;
+
+	type = su_get_type(dp);
+	if (type == SU_PORT_PORT) {
+		if (nr_inst >= UART_NR)
+			return -EINVAL;
+		up = &sunsu_ports[nr_inst];
+	} else {
+		up = kzalloc(sizeof(*up), GFP_KERNEL);
+		if (!up)
+			return -ENOMEM;
+	}
+
+	up->port.line = nr_inst;
+
+	spin_lock_init(&up->port.lock);
+
+	up->su_type = type;
+
+	rp = &op->resource[0];
+	up->port.mapbase = rp->start;
+	up->reg_size = resource_size(rp);
+	up->port.membase = of_ioremap(rp, 0, up->reg_size, "su");
+	if (!up->port.membase) {
+		if (type != SU_PORT_PORT)
+			kfree(up);
+		return -ENOMEM;
+	}
+
+	up->port.irq = op->archdata.irqs[0];
+
+	up->port.dev = &op->dev;
+
+	up->port.type = PORT_UNKNOWN;
+	up->port.uartclk = (SU_BASE_BAUD * 16);
+	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSU_CONSOLE);
+
+	err = 0;
+	if (up->su_type == SU_PORT_KBD || up->su_type == SU_PORT_MS) {
+		err = sunsu_kbd_ms_init(up);
+		if (err) {
+			of_iounmap(&op->resource[0],
+				   up->port.membase, up->reg_size);
+			kfree(up);
+			return err;
+		}
+		platform_set_drvdata(op, up);
+
+		nr_inst++;
+
+		return 0;
+	}
+
+	up->port.flags |= UPF_BOOT_AUTOCONF;
+
+	sunsu_autoconfig(up);
+
+	err = -ENODEV;
+	if (up->port.type == PORT_UNKNOWN)
+		goto out_unmap;
+
+	up->port.ops = &sunsu_pops;
+
+	ignore_line = false;
+	if (of_node_name_eq(dp, "rsc-console") ||
+	    of_node_name_eq(dp, "lom-console"))
+		ignore_line = true;
+
+	sunserial_console_match(SUNSU_CONSOLE(), dp,
+				&sunsu_reg, up->port.line,
+				ignore_line);
+	err = uart_add_one_port(&sunsu_reg, &up->port);
+	if (err)
+		goto out_unmap;
+
+	platform_set_drvdata(op, up);
+
+	nr_inst++;
+
+	return 0;
+
+out_unmap:
+	of_iounmap(&op->resource[0], up->port.membase, up->reg_size);
+	kfree(up);
+	return err;
+}
+
+static int su_remove(struct platform_device *op)
+{
+	struct uart_sunsu_port *up = platform_get_drvdata(op);
+	bool kbdms = false;
+
+	if (up->su_type == SU_PORT_MS ||
+	    up->su_type == SU_PORT_KBD)
+		kbdms = true;
+
+	if (kbdms) {
+#ifdef CONFIG_SERIO
+		serio_unregister_port(&up->serio);
+#endif
+	} else if (up->port.type != PORT_UNKNOWN)
+		uart_remove_one_port(&sunsu_reg, &up->port);
+
+	if (up->port.membase)
+		of_iounmap(&op->resource[0], up->port.membase, up->reg_size);
+
+	if (kbdms)
+		kfree(up);
+
+	return 0;
+}
+
+static const struct of_device_id su_match[] = {
+	{
+		.name = "su",
+	},
+	{
+		.name = "su_pnp",
+	},
+	{
+		.name = "serial",
+		.compatible = "su",
+	},
+	{
+		.type = "serial",
+		.compatible = "su",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, su_match);
+
+static struct platform_driver su_driver = {
+	.driver = {
+		.name = "su",
+		.of_match_table = su_match,
+	},
+	.probe		= su_probe,
+	.remove		= su_remove,
+};
+
+static int __init sunsu_init(void)
+{
+	struct device_node *dp;
+	int err;
+	int num_uart = 0;
+
+	for_each_node_by_name(dp, "su") {
+		if (su_get_type(dp) == SU_PORT_PORT)
+			num_uart++;
+	}
+	for_each_node_by_name(dp, "su_pnp") {
+		if (su_get_type(dp) == SU_PORT_PORT)
+			num_uart++;
+	}
+	for_each_node_by_name(dp, "serial") {
+		if (of_device_is_compatible(dp, "su")) {
+			if (su_get_type(dp) == SU_PORT_PORT)
+				num_uart++;
+		}
+	}
+	for_each_node_by_type(dp, "serial") {
+		if (of_device_is_compatible(dp, "su")) {
+			if (su_get_type(dp) == SU_PORT_PORT)
+				num_uart++;
+		}
+	}
+
+	if (num_uart) {
+		err = sunserial_register_minors(&sunsu_reg, num_uart);
+		if (err)
+			return err;
+	}
+
+	err = platform_driver_register(&su_driver);
+	if (err && num_uart)
+		sunserial_unregister_minors(&sunsu_reg, num_uart);
+
+	return err;
+}
+
+static void __exit sunsu_exit(void)
+{
+	platform_driver_unregister(&su_driver);
+	if (sunsu_reg.nr)
+		sunserial_unregister_minors(&sunsu_reg, sunsu_reg.nr);
+}
+
+module_init(sunsu_init);
+module_exit(sunsu_exit);
+
+MODULE_AUTHOR("Eddie C. Dost, Peter Zaitcev, and David S. Miller");
+MODULE_DESCRIPTION("Sun SU serial port driver");
+MODULE_VERSION("2.0");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
new file mode 100644
index 000000000..c8c71c562
--- /dev/null
+++ b/drivers/tty/serial/sunzilog.c
@@ -0,0 +1,1649 @@
+// SPDX-License-Identifier: GPL-2.0
+/* sunzilog.c: Zilog serial driver for Sparc systems.
+ *
+ * Driver for Zilog serial chips found on Sun workstations and
+ * servers.  This driver could actually be made more generic.
+ *
+ * This is based on the old drivers/sbus/char/zs.c code.  A lot
+ * of code has been simply moved over directly from there but
+ * much has been rewritten.  Credits therefore go out to Eddie
+ * C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell for their
+ * work there.
+ *
+ * Copyright (C) 2002, 2006, 2007 David S. Miller (davem@davemloft.net)
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/spinlock.h>
+#ifdef CONFIG_SERIO
+#include <linux/serio.h>
+#endif
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <asm/setup.h>
+
+#include <linux/serial_core.h>
+#include <linux/sunserialcore.h>
+
+#include "sunzilog.h"
+
+/* On 32-bit sparcs we need to delay after register accesses
+ * to accommodate sun4 systems, but we do not need to flush writes.
+ * On 64-bit sparc we only need to flush single writes to ensure
+ * completion.
+ */
+#ifndef CONFIG_SPARC64
+#define ZSDELAY()		udelay(5)
+#define ZSDELAY_LONG()		udelay(20)
+#define ZS_WSYNC(channel)	do { } while (0)
+#else
+#define ZSDELAY()
+#define ZSDELAY_LONG()
+#define ZS_WSYNC(__channel) \
+	readb(&((__channel)->control))
+#endif
+
+#define ZS_CLOCK		4915200 /* Zilog input clock rate. */
+#define ZS_CLOCK_DIVISOR	16      /* Divisor this driver uses. */
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_sunzilog_port {
+	struct uart_port		port;
+
+	/* IRQ servicing chain.  */
+	struct uart_sunzilog_port	*next;
+
+	/* Current values of Zilog write registers.  */
+	unsigned char			curregs[NUM_ZSREGS];
+
+	unsigned int			flags;
+#define SUNZILOG_FLAG_CONS_KEYB		0x00000001
+#define SUNZILOG_FLAG_CONS_MOUSE	0x00000002
+#define SUNZILOG_FLAG_IS_CONS		0x00000004
+#define SUNZILOG_FLAG_IS_KGDB		0x00000008
+#define SUNZILOG_FLAG_MODEM_STATUS	0x00000010
+#define SUNZILOG_FLAG_IS_CHANNEL_A	0x00000020
+#define SUNZILOG_FLAG_REGS_HELD		0x00000040
+#define SUNZILOG_FLAG_TX_STOPPED	0x00000080
+#define SUNZILOG_FLAG_TX_ACTIVE		0x00000100
+#define SUNZILOG_FLAG_ESCC		0x00000200
+#define SUNZILOG_FLAG_ISR_HANDLER	0x00000400
+
+	unsigned int cflag;
+
+	unsigned char			parity_mask;
+	unsigned char			prev_status;
+
+#ifdef CONFIG_SERIO
+	struct serio			serio;
+	int				serio_open;
+#endif
+};
+
+static void sunzilog_putchar(struct uart_port *port, unsigned char ch);
+
+#define ZILOG_CHANNEL_FROM_PORT(PORT)	((struct zilog_channel __iomem *)((PORT)->membase))
+#define UART_ZILOG(PORT)		((struct uart_sunzilog_port *)(PORT))
+
+#define ZS_IS_KEYB(UP)	((UP)->flags & SUNZILOG_FLAG_CONS_KEYB)
+#define ZS_IS_MOUSE(UP)	((UP)->flags & SUNZILOG_FLAG_CONS_MOUSE)
+#define ZS_IS_CONS(UP)	((UP)->flags & SUNZILOG_FLAG_IS_CONS)
+#define ZS_IS_KGDB(UP)	((UP)->flags & SUNZILOG_FLAG_IS_KGDB)
+#define ZS_WANTS_MODEM_STATUS(UP)	((UP)->flags & SUNZILOG_FLAG_MODEM_STATUS)
+#define ZS_IS_CHANNEL_A(UP)	((UP)->flags & SUNZILOG_FLAG_IS_CHANNEL_A)
+#define ZS_REGS_HELD(UP)	((UP)->flags & SUNZILOG_FLAG_REGS_HELD)
+#define ZS_TX_STOPPED(UP)	((UP)->flags & SUNZILOG_FLAG_TX_STOPPED)
+#define ZS_TX_ACTIVE(UP)	((UP)->flags & SUNZILOG_FLAG_TX_ACTIVE)
+
+/* Reading and writing Zilog8530 registers.  The delays are to make this
+ * driver work on the Sun4 which needs a settling delay after each chip
+ * register access, other machines handle this in hardware via auxiliary
+ * flip-flops which implement the settle time we do in software.
+ *
+ * The port lock must be held and local IRQs must be disabled
+ * when {read,write}_zsreg is invoked.
+ */
+static unsigned char read_zsreg(struct zilog_channel __iomem *channel,
+				unsigned char reg)
+{
+	unsigned char retval;
+
+	writeb(reg, &channel->control);
+	ZSDELAY();
+	retval = readb(&channel->control);
+	ZSDELAY();
+
+	return retval;
+}
+
+static void write_zsreg(struct zilog_channel __iomem *channel,
+			unsigned char reg, unsigned char value)
+{
+	writeb(reg, &channel->control);
+	ZSDELAY();
+	writeb(value, &channel->control);
+	ZSDELAY();
+}
+
+static void sunzilog_clear_fifo(struct zilog_channel __iomem *channel)
+{
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		unsigned char regval;
+
+		regval = readb(&channel->control);
+		ZSDELAY();
+		if (regval & Rx_CH_AV)
+			break;
+
+		regval = read_zsreg(channel, R1);
+		readb(&channel->data);
+		ZSDELAY();
+
+		if (regval & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+			writeb(ERR_RES, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+		}
+	}
+}
+
+/* This function must only be called when the TX is not busy.  The UART
+ * port lock must be held and local interrupts disabled.
+ */
+static int __load_zsregs(struct zilog_channel __iomem *channel, unsigned char *regs)
+{
+	int i;
+	int escc;
+	unsigned char r15;
+
+	/* Let pending transmits finish.  */
+	for (i = 0; i < 1000; i++) {
+		unsigned char stat = read_zsreg(channel, R1);
+		if (stat & ALL_SNT)
+			break;
+		udelay(100);
+	}
+
+	writeb(ERR_RES, &channel->control);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+
+	sunzilog_clear_fifo(channel);
+
+	/* Disable all interrupts.  */
+	write_zsreg(channel, R1,
+		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
+
+	/* Set parity, sync config, stop bits, and clock divisor.  */
+	write_zsreg(channel, R4, regs[R4]);
+
+	/* Set misc. TX/RX control bits.  */
+	write_zsreg(channel, R10, regs[R10]);
+
+	/* Set TX/RX controls sans the enable bits.  */
+	write_zsreg(channel, R3, regs[R3] & ~RxENAB);
+	write_zsreg(channel, R5, regs[R5] & ~TxENAB);
+
+	/* Synchronous mode config.  */
+	write_zsreg(channel, R6, regs[R6]);
+	write_zsreg(channel, R7, regs[R7]);
+
+	/* Don't mess with the interrupt vector (R2, unused by us) and
+	 * master interrupt control (R9).  We make sure this is setup
+	 * properly at probe time then never touch it again.
+	 */
+
+	/* Disable baud generator.  */
+	write_zsreg(channel, R14, regs[R14] & ~BRENAB);
+
+	/* Clock mode control.  */
+	write_zsreg(channel, R11, regs[R11]);
+
+	/* Lower and upper byte of baud rate generator divisor.  */
+	write_zsreg(channel, R12, regs[R12]);
+	write_zsreg(channel, R13, regs[R13]);
+	
+	/* Now rewrite R14, with BRENAB (if set).  */
+	write_zsreg(channel, R14, regs[R14]);
+
+	/* External status interrupt control.  */
+	write_zsreg(channel, R15, (regs[R15] | WR7pEN) & ~FIFOEN);
+
+	/* ESCC Extension Register */
+	r15 = read_zsreg(channel, R15);
+	if (r15 & 0x01)	{
+		write_zsreg(channel, R7,  regs[R7p]);
+
+		/* External status interrupt and FIFO control.  */
+		write_zsreg(channel, R15, regs[R15] & ~WR7pEN);
+		escc = 1;
+	} else {
+		 /* Clear FIFO bit case it is an issue */
+		regs[R15] &= ~FIFOEN;
+		escc = 0;
+	}
+
+	/* Reset external status interrupts.  */
+	write_zsreg(channel, R0, RES_EXT_INT); /* First Latch  */
+	write_zsreg(channel, R0, RES_EXT_INT); /* Second Latch */
+
+	/* Rewrite R3/R5, this time without enables masked.  */
+	write_zsreg(channel, R3, regs[R3]);
+	write_zsreg(channel, R5, regs[R5]);
+
+	/* Rewrite R1, this time without IRQ enabled masked.  */
+	write_zsreg(channel, R1, regs[R1]);
+
+	return escc;
+}
+
+/* Reprogram the Zilog channel HW registers with the copies found in the
+ * software state struct.  If the transmitter is busy, we defer this update
+ * until the next TX complete interrupt.  Else, we do it right now.
+ *
+ * The UART port lock must be held and local interrupts disabled.
+ */
+static void sunzilog_maybe_update_regs(struct uart_sunzilog_port *up,
+				       struct zilog_channel __iomem *channel)
+{
+	if (!ZS_REGS_HELD(up)) {
+		if (ZS_TX_ACTIVE(up)) {
+			up->flags |= SUNZILOG_FLAG_REGS_HELD;
+		} else {
+			__load_zsregs(channel, up->curregs);
+		}
+	}
+}
+
+static void sunzilog_change_mouse_baud(struct uart_sunzilog_port *up)
+{
+	unsigned int cur_cflag = up->cflag;
+	int brg, new_baud;
+
+	up->cflag &= ~CBAUD;
+	up->cflag |= suncore_mouse_baud_cflag_next(cur_cflag, &new_baud);
+
+	brg = BPS_TO_BRG(new_baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+	up->curregs[R12] = (brg & 0xff);
+	up->curregs[R13] = (brg >> 8) & 0xff;
+	sunzilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(&up->port));
+}
+
+static void sunzilog_kbdms_receive_chars(struct uart_sunzilog_port *up,
+					 unsigned char ch, int is_break)
+{
+	if (ZS_IS_KEYB(up)) {
+		/* Stop-A is handled by drivers/char/keyboard.c now. */
+#ifdef CONFIG_SERIO
+		if (up->serio_open)
+			serio_interrupt(&up->serio, ch, 0);
+#endif
+	} else if (ZS_IS_MOUSE(up)) {
+		int ret = suncore_mouse_baud_detection(ch, is_break);
+
+		switch (ret) {
+		case 2:
+			sunzilog_change_mouse_baud(up);
+			fallthrough;
+		case 1:
+			break;
+
+		case 0:
+#ifdef CONFIG_SERIO
+			if (up->serio_open)
+				serio_interrupt(&up->serio, ch, 0);
+#endif
+			break;
+		}
+	}
+}
+
+static struct tty_port *
+sunzilog_receive_chars(struct uart_sunzilog_port *up,
+		       struct zilog_channel __iomem *channel)
+{
+	struct tty_port *port = NULL;
+	unsigned char ch, r1, flag;
+
+	if (up->port.state != NULL)		/* Unopened serial console */
+		port = &up->port.state->port;
+
+	for (;;) {
+
+		r1 = read_zsreg(channel, R1);
+		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+			writeb(ERR_RES, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+		}
+
+		ch = readb(&channel->control);
+		ZSDELAY();
+
+		/* This funny hack depends upon BRK_ABRT not interfering
+		 * with the other bits we care about in R1.
+		 */
+		if (ch & BRK_ABRT)
+			r1 |= BRK_ABRT;
+
+		if (!(ch & Rx_CH_AV))
+			break;
+
+		ch = readb(&channel->data);
+		ZSDELAY();
+
+		ch &= up->parity_mask;
+
+		if (unlikely(ZS_IS_KEYB(up)) || unlikely(ZS_IS_MOUSE(up))) {
+			sunzilog_kbdms_receive_chars(up, ch, 0);
+			continue;
+		}
+
+		/* A real serial line, record the character and status.  */
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+		if (r1 & (BRK_ABRT | PAR_ERR | Rx_OVR | CRC_ERR)) {
+			if (r1 & BRK_ABRT) {
+				r1 &= ~(PAR_ERR | CRC_ERR);
+				up->port.icount.brk++;
+				if (uart_handle_break(&up->port))
+					continue;
+			}
+			else if (r1 & PAR_ERR)
+				up->port.icount.parity++;
+			else if (r1 & CRC_ERR)
+				up->port.icount.frame++;
+			if (r1 & Rx_OVR)
+				up->port.icount.overrun++;
+			r1 &= up->port.read_status_mask;
+			if (r1 & BRK_ABRT)
+				flag = TTY_BREAK;
+			else if (r1 & PAR_ERR)
+				flag = TTY_PARITY;
+			else if (r1 & CRC_ERR)
+				flag = TTY_FRAME;
+		}
+		if (uart_handle_sysrq_char(&up->port, ch) || !port)
+			continue;
+
+		if (up->port.ignore_status_mask == 0xff ||
+		    (r1 & up->port.ignore_status_mask) == 0) {
+		    	tty_insert_flip_char(port, ch, flag);
+		}
+		if (r1 & Rx_OVR)
+			tty_insert_flip_char(port, 0, TTY_OVERRUN);
+	}
+
+	return port;
+}
+
+static void sunzilog_status_handle(struct uart_sunzilog_port *up,
+				   struct zilog_channel __iomem *channel)
+{
+	unsigned char status;
+
+	status = readb(&channel->control);
+	ZSDELAY();
+
+	writeb(RES_EXT_INT, &channel->control);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+
+	if (status & BRK_ABRT) {
+		if (ZS_IS_MOUSE(up))
+			sunzilog_kbdms_receive_chars(up, 0, 1);
+		if (ZS_IS_CONS(up)) {
+			/* Wait for BREAK to deassert to avoid potentially
+			 * confusing the PROM.
+			 */
+			while (1) {
+				status = readb(&channel->control);
+				ZSDELAY();
+				if (!(status & BRK_ABRT))
+					break;
+			}
+			sun_do_break();
+			return;
+		}
+	}
+
+	if (ZS_WANTS_MODEM_STATUS(up)) {
+		if (status & SYNC)
+			up->port.icount.dsr++;
+
+		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
+		 * But it does not tell us which bit has changed, we have to keep
+		 * track of this ourselves.
+		 */
+		if ((status ^ up->prev_status) ^ DCD)
+			uart_handle_dcd_change(&up->port,
+					       (status & DCD));
+		if ((status ^ up->prev_status) ^ CTS)
+			uart_handle_cts_change(&up->port,
+					       (status & CTS));
+
+		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+	}
+
+	up->prev_status = status;
+}
+
+static void sunzilog_transmit_chars(struct uart_sunzilog_port *up,
+				    struct zilog_channel __iomem *channel)
+{
+	struct circ_buf *xmit;
+
+	if (ZS_IS_CONS(up)) {
+		unsigned char status = readb(&channel->control);
+		ZSDELAY();
+
+		/* TX still busy?  Just wait for the next TX done interrupt.
+		 *
+		 * It can occur because of how we do serial console writes.  It would
+		 * be nice to transmit console writes just like we normally would for
+		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
+		 * easy because console writes cannot sleep.  One solution might be
+		 * to poll on enough port->xmit space becoming free.  -DaveM
+		 */
+		if (!(status & Tx_BUF_EMP))
+			return;
+	}
+
+	up->flags &= ~SUNZILOG_FLAG_TX_ACTIVE;
+
+	if (ZS_REGS_HELD(up)) {
+		__load_zsregs(channel, up->curregs);
+		up->flags &= ~SUNZILOG_FLAG_REGS_HELD;
+	}
+
+	if (ZS_TX_STOPPED(up)) {
+		up->flags &= ~SUNZILOG_FLAG_TX_STOPPED;
+		goto ack_tx_int;
+	}
+
+	if (up->port.x_char) {
+		up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
+		writeb(up->port.x_char, &channel->data);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+
+		up->port.icount.tx++;
+		up->port.x_char = 0;
+		return;
+	}
+
+	if (up->port.state == NULL)
+		goto ack_tx_int;
+	xmit = &up->port.state->xmit;
+	if (uart_circ_empty(xmit))
+		goto ack_tx_int;
+
+	if (uart_tx_stopped(&up->port))
+		goto ack_tx_int;
+
+	up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
+	writeb(xmit->buf[xmit->tail], &channel->data);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+
+	uart_xmit_advance(&up->port, 1);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	return;
+
+ack_tx_int:
+	writeb(RES_Tx_P, &channel->control);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+}
+
+static irqreturn_t sunzilog_interrupt(int irq, void *dev_id)
+{
+	struct uart_sunzilog_port *up = dev_id;
+
+	while (up) {
+		struct zilog_channel __iomem *channel
+			= ZILOG_CHANNEL_FROM_PORT(&up->port);
+		struct tty_port *port;
+		unsigned char r3;
+
+		spin_lock(&up->port.lock);
+		r3 = read_zsreg(channel, R3);
+
+		/* Channel A */
+		port = NULL;
+		if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
+			writeb(RES_H_IUS, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+
+			if (r3 & CHARxIP)
+				port = sunzilog_receive_chars(up, channel);
+			if (r3 & CHAEXT)
+				sunzilog_status_handle(up, channel);
+			if (r3 & CHATxIP)
+				sunzilog_transmit_chars(up, channel);
+		}
+		spin_unlock(&up->port.lock);
+
+		if (port)
+			tty_flip_buffer_push(port);
+
+		/* Channel B */
+		up = up->next;
+		channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+
+		spin_lock(&up->port.lock);
+		port = NULL;
+		if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
+			writeb(RES_H_IUS, &channel->control);
+			ZSDELAY();
+			ZS_WSYNC(channel);
+
+			if (r3 & CHBRxIP)
+				port = sunzilog_receive_chars(up, channel);
+			if (r3 & CHBEXT)
+				sunzilog_status_handle(up, channel);
+			if (r3 & CHBTxIP)
+				sunzilog_transmit_chars(up, channel);
+		}
+		spin_unlock(&up->port.lock);
+
+		if (port)
+			tty_flip_buffer_push(port);
+
+		up = up->next;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/* A convenient way to quickly get R0 status.  The caller must _not_ hold the
+ * port lock, it is acquired here.
+ */
+static __inline__ unsigned char sunzilog_read_channel_status(struct uart_port *port)
+{
+	struct zilog_channel __iomem *channel;
+	unsigned char status;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(port);
+	status = readb(&channel->control);
+	ZSDELAY();
+
+	return status;
+}
+
+/* The port lock is not held.  */
+static unsigned int sunzilog_tx_empty(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned char status;
+	unsigned int ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	status = sunzilog_read_channel_status(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (status & Tx_BUF_EMP)
+		ret = TIOCSER_TEMT;
+	else
+		ret = 0;
+
+	return ret;
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static unsigned int sunzilog_get_mctrl(struct uart_port *port)
+{
+	unsigned char status;
+	unsigned int ret;
+
+	status = sunzilog_read_channel_status(port);
+
+	ret = 0;
+	if (status & DCD)
+		ret |= TIOCM_CAR;
+	if (status & SYNC)
+		ret |= TIOCM_DSR;
+	if (status & CTS)
+		ret |= TIOCM_CTS;
+
+	return ret;
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void sunzilog_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+	struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char set_bits, clear_bits;
+
+	set_bits = clear_bits = 0;
+
+	if (mctrl & TIOCM_RTS)
+		set_bits |= RTS;
+	else
+		clear_bits |= RTS;
+	if (mctrl & TIOCM_DTR)
+		set_bits |= DTR;
+	else
+		clear_bits |= DTR;
+
+	/* NOTE: Not subject to 'transmitter active' rule.  */ 
+	up->curregs[R5] |= set_bits;
+	up->curregs[R5] &= ~clear_bits;
+	write_zsreg(channel, R5, up->curregs[R5]);
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void sunzilog_stop_tx(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+
+	up->flags |= SUNZILOG_FLAG_TX_STOPPED;
+}
+
+/* The port lock is held and interrupts are disabled.  */
+static void sunzilog_start_tx(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+	struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char status;
+
+	up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
+	up->flags &= ~SUNZILOG_FLAG_TX_STOPPED;
+
+	status = readb(&channel->control);
+	ZSDELAY();
+
+	/* TX busy?  Just wait for the TX done interrupt.  */
+	if (!(status & Tx_BUF_EMP))
+		return;
+
+	/* Send the first character to jump-start the TX done
+	 * IRQ sending engine.
+	 */
+	if (port->x_char) {
+		writeb(port->x_char, &channel->data);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+
+		port->icount.tx++;
+		port->x_char = 0;
+	} else {
+		struct circ_buf *xmit = &port->state->xmit;
+
+		if (uart_circ_empty(xmit))
+			return;
+		writeb(xmit->buf[xmit->tail], &channel->data);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+
+		uart_xmit_advance(port, 1);
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&up->port);
+	}
+}
+
+/* The port lock is held.  */
+static void sunzilog_stop_rx(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up = UART_ZILOG(port);
+	struct zilog_channel __iomem *channel;
+
+	if (ZS_IS_CONS(up))
+		return;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(port);
+
+	/* Disable all RX interrupts.  */
+	up->curregs[R1] &= ~RxINT_MASK;
+	sunzilog_maybe_update_regs(up, channel);
+}
+
+/* The port lock is held.  */
+static void sunzilog_enable_ms(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+	struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char new_reg;
+
+	new_reg = up->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
+	if (new_reg != up->curregs[R15]) {
+		up->curregs[R15] = new_reg;
+
+		/* NOTE: Not subject to 'transmitter active' rule.  */ 
+		write_zsreg(channel, R15, up->curregs[R15] & ~WR7pEN);
+	}
+}
+
+/* The port lock is not held.  */
+static void sunzilog_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+	struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	unsigned char set_bits, clear_bits, new_reg;
+	unsigned long flags;
+
+	set_bits = clear_bits = 0;
+
+	if (break_state)
+		set_bits |= SND_BRK;
+	else
+		clear_bits |= SND_BRK;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
+	if (new_reg != up->curregs[R5]) {
+		up->curregs[R5] = new_reg;
+
+		/* NOTE: Not subject to 'transmitter active' rule.  */ 
+		write_zsreg(channel, R5, up->curregs[R5]);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void __sunzilog_startup(struct uart_sunzilog_port *up)
+{
+	struct zilog_channel __iomem *channel;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+	up->prev_status = readb(&channel->control);
+
+	/* Enable receiver and transmitter.  */
+	up->curregs[R3] |= RxENAB;
+	up->curregs[R5] |= TxENAB;
+
+	up->curregs[R1] |= EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+	sunzilog_maybe_update_regs(up, channel);
+}
+
+static int sunzilog_startup(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up = UART_ZILOG(port);
+	unsigned long flags;
+
+	if (ZS_IS_CONS(up))
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+	__sunzilog_startup(up);
+	spin_unlock_irqrestore(&port->lock, flags);
+	return 0;
+}
+
+/*
+ * The test for ZS_IS_CONS is explained by the following e-mail:
+ *****
+ * From: Russell King <rmk@arm.linux.org.uk>
+ * Date: Sun, 8 Dec 2002 10:18:38 +0000
+ *
+ * On Sun, Dec 08, 2002 at 02:43:36AM -0500, Pete Zaitcev wrote:
+ * > I boot my 2.5 boxes using "console=ttyS0,9600" argument,
+ * > and I noticed that something is not right with reference
+ * > counting in this case. It seems that when the console
+ * > is open by kernel initially, this is not accounted
+ * > as an open, and uart_startup is not called.
+ *
+ * That is correct.  We are unable to call uart_startup when the serial
+ * console is initialised because it may need to allocate memory (as
+ * request_irq does) and the memory allocators may not have been
+ * initialised.
+ *
+ * 1. initialise the port into a state where it can send characters in the
+ *    console write method.
+ *
+ * 2. don't do the actual hardware shutdown in your shutdown() method (but
+ *    do the normal software shutdown - ie, free irqs etc)
+ *****
+ */
+static void sunzilog_shutdown(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up = UART_ZILOG(port);
+	struct zilog_channel __iomem *channel;
+	unsigned long flags;
+
+	if (ZS_IS_CONS(up))
+		return;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	channel = ZILOG_CHANNEL_FROM_PORT(port);
+
+	/* Disable receiver and transmitter.  */
+	up->curregs[R3] &= ~RxENAB;
+	up->curregs[R5] &= ~TxENAB;
+
+	/* Disable all interrupts and BRK assertion.  */
+	up->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
+	up->curregs[R5] &= ~SND_BRK;
+	sunzilog_maybe_update_regs(up, channel);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* Shared by TTY driver and serial console setup.  The port lock is held
+ * and local interrupts are disabled.
+ */
+static void
+sunzilog_convert_to_zs(struct uart_sunzilog_port *up, unsigned int cflag,
+		       unsigned int iflag, int brg)
+{
+
+	up->curregs[R10] = NRZ;
+	up->curregs[R11] = TCBR | RCBR;
+
+	/* Program BAUD and clock source. */
+	up->curregs[R4] &= ~XCLK_MASK;
+	up->curregs[R4] |= X16CLK;
+	up->curregs[R12] = brg & 0xff;
+	up->curregs[R13] = (brg >> 8) & 0xff;
+	up->curregs[R14] = BRSRC | BRENAB;
+
+	/* Character size, stop bits, and parity. */
+	up->curregs[R3] &= ~RxN_MASK;
+	up->curregs[R5] &= ~TxN_MASK;
+	switch (cflag & CSIZE) {
+	case CS5:
+		up->curregs[R3] |= Rx5;
+		up->curregs[R5] |= Tx5;
+		up->parity_mask = 0x1f;
+		break;
+	case CS6:
+		up->curregs[R3] |= Rx6;
+		up->curregs[R5] |= Tx6;
+		up->parity_mask = 0x3f;
+		break;
+	case CS7:
+		up->curregs[R3] |= Rx7;
+		up->curregs[R5] |= Tx7;
+		up->parity_mask = 0x7f;
+		break;
+	case CS8:
+	default:
+		up->curregs[R3] |= Rx8;
+		up->curregs[R5] |= Tx8;
+		up->parity_mask = 0xff;
+		break;
+	}
+	up->curregs[R4] &= ~0x0c;
+	if (cflag & CSTOPB)
+		up->curregs[R4] |= SB2;
+	else
+		up->curregs[R4] |= SB1;
+	if (cflag & PARENB)
+		up->curregs[R4] |= PAR_ENAB;
+	else
+		up->curregs[R4] &= ~PAR_ENAB;
+	if (!(cflag & PARODD))
+		up->curregs[R4] |= PAR_EVEN;
+	else
+		up->curregs[R4] &= ~PAR_EVEN;
+
+	up->port.read_status_mask = Rx_OVR;
+	if (iflag & INPCK)
+		up->port.read_status_mask |= CRC_ERR | PAR_ERR;
+	if (iflag & (IGNBRK | BRKINT | PARMRK))
+		up->port.read_status_mask |= BRK_ABRT;
+
+	up->port.ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		up->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
+	if (iflag & IGNBRK) {
+		up->port.ignore_status_mask |= BRK_ABRT;
+		if (iflag & IGNPAR)
+			up->port.ignore_status_mask |= Rx_OVR;
+	}
+
+	if ((cflag & CREAD) == 0)
+		up->port.ignore_status_mask = 0xff;
+}
+
+/* The port lock is not held.  */
+static void
+sunzilog_set_termios(struct uart_port *port, struct ktermios *termios,
+		     const struct ktermios *old)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+	unsigned long flags;
+	int baud, brg;
+
+	baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+
+	sunzilog_convert_to_zs(up, termios->c_cflag, termios->c_iflag, brg);
+
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->flags |= SUNZILOG_FLAG_MODEM_STATUS;
+	else
+		up->flags &= ~SUNZILOG_FLAG_MODEM_STATUS;
+
+	up->cflag = termios->c_cflag;
+
+	sunzilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port));
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *sunzilog_type(struct uart_port *port)
+{
+	struct uart_sunzilog_port *up = UART_ZILOG(port);
+
+	return (up->flags & SUNZILOG_FLAG_ESCC) ? "zs (ESCC)" : "zs";
+}
+
+/* We do not request/release mappings of the registers here, this
+ * happens at early serial probe time.
+ */
+static void sunzilog_release_port(struct uart_port *port)
+{
+}
+
+static int sunzilog_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/* These do not need to do anything interesting either.  */
+static void sunzilog_config_port(struct uart_port *port, int flags)
+{
+}
+
+/* We do not support letting the user mess with the divisor, IRQ, etc. */
+static int sunzilog_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int sunzilog_get_poll_char(struct uart_port *port)
+{
+	unsigned char ch, r1;
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+	struct zilog_channel __iomem *channel
+		= ZILOG_CHANNEL_FROM_PORT(&up->port);
+
+
+	r1 = read_zsreg(channel, R1);
+	if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
+		writeb(ERR_RES, &channel->control);
+		ZSDELAY();
+		ZS_WSYNC(channel);
+	}
+
+	ch = readb(&channel->control);
+	ZSDELAY();
+
+	/* This funny hack depends upon BRK_ABRT not interfering
+	 * with the other bits we care about in R1.
+	 */
+	if (ch & BRK_ABRT)
+		r1 |= BRK_ABRT;
+
+	if (!(ch & Rx_CH_AV))
+		return NO_POLL_CHAR;
+
+	ch = readb(&channel->data);
+	ZSDELAY();
+
+	ch &= up->parity_mask;
+	return ch;
+}
+
+static void sunzilog_put_poll_char(struct uart_port *port,
+			unsigned char ch)
+{
+	struct uart_sunzilog_port *up =
+		container_of(port, struct uart_sunzilog_port, port);
+
+	sunzilog_putchar(&up->port, ch);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops sunzilog_pops = {
+	.tx_empty	=	sunzilog_tx_empty,
+	.set_mctrl	=	sunzilog_set_mctrl,
+	.get_mctrl	=	sunzilog_get_mctrl,
+	.stop_tx	=	sunzilog_stop_tx,
+	.start_tx	=	sunzilog_start_tx,
+	.stop_rx	=	sunzilog_stop_rx,
+	.enable_ms	=	sunzilog_enable_ms,
+	.break_ctl	=	sunzilog_break_ctl,
+	.startup	=	sunzilog_startup,
+	.shutdown	=	sunzilog_shutdown,
+	.set_termios	=	sunzilog_set_termios,
+	.type		=	sunzilog_type,
+	.release_port	=	sunzilog_release_port,
+	.request_port	=	sunzilog_request_port,
+	.config_port	=	sunzilog_config_port,
+	.verify_port	=	sunzilog_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	=	sunzilog_get_poll_char,
+	.poll_put_char	=	sunzilog_put_poll_char,
+#endif
+};
+
+static int uart_chip_count;
+static struct uart_sunzilog_port *sunzilog_port_table;
+static struct zilog_layout __iomem **sunzilog_chip_regs;
+
+static struct uart_sunzilog_port *sunzilog_irq_chain;
+
+static struct uart_driver sunzilog_reg = {
+	.owner		=	THIS_MODULE,
+	.driver_name	=	"sunzilog",
+	.dev_name	=	"ttyS",
+	.major		=	TTY_MAJOR,
+};
+
+static int __init sunzilog_alloc_tables(int num_sunzilog)
+{
+	struct uart_sunzilog_port *up;
+	unsigned long size;
+	int num_channels = num_sunzilog * 2;
+	int i;
+
+	size = num_channels * sizeof(struct uart_sunzilog_port);
+	sunzilog_port_table = kzalloc(size, GFP_KERNEL);
+	if (!sunzilog_port_table)
+		return -ENOMEM;
+
+	for (i = 0; i < num_channels; i++) {
+		up = &sunzilog_port_table[i];
+
+		spin_lock_init(&up->port.lock);
+
+		if (i == 0)
+			sunzilog_irq_chain = up;
+
+		if (i < num_channels - 1)
+			up->next = up + 1;
+		else
+			up->next = NULL;
+	}
+
+	size = num_sunzilog * sizeof(struct zilog_layout __iomem *);
+	sunzilog_chip_regs = kzalloc(size, GFP_KERNEL);
+	if (!sunzilog_chip_regs) {
+		kfree(sunzilog_port_table);
+		sunzilog_irq_chain = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void sunzilog_free_tables(void)
+{
+	kfree(sunzilog_port_table);
+	sunzilog_irq_chain = NULL;
+	kfree(sunzilog_chip_regs);
+}
+
+#define ZS_PUT_CHAR_MAX_DELAY	2000	/* 10 ms */
+
+static void __maybe_unused sunzilog_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
+	int loops = ZS_PUT_CHAR_MAX_DELAY;
+
+	/* This is a timed polling loop so do not switch the explicit
+	 * udelay with ZSDELAY as that is a NOP on some platforms.  -DaveM
+	 */
+	do {
+		unsigned char val = readb(&channel->control);
+		if (val & Tx_BUF_EMP) {
+			ZSDELAY();
+			break;
+		}
+		udelay(5);
+	} while (--loops);
+
+	writeb(ch, &channel->data);
+	ZSDELAY();
+	ZS_WSYNC(channel);
+}
+
+#ifdef CONFIG_SERIO
+
+static DEFINE_SPINLOCK(sunzilog_serio_lock);
+
+static int sunzilog_serio_write(struct serio *serio, unsigned char ch)
+{
+	struct uart_sunzilog_port *up = serio->port_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sunzilog_serio_lock, flags);
+
+	sunzilog_putchar(&up->port, ch);
+
+	spin_unlock_irqrestore(&sunzilog_serio_lock, flags);
+
+	return 0;
+}
+
+static int sunzilog_serio_open(struct serio *serio)
+{
+	struct uart_sunzilog_port *up = serio->port_data;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&sunzilog_serio_lock, flags);
+	if (!up->serio_open) {
+		up->serio_open = 1;
+		ret = 0;
+	} else
+		ret = -EBUSY;
+	spin_unlock_irqrestore(&sunzilog_serio_lock, flags);
+
+	return ret;
+}
+
+static void sunzilog_serio_close(struct serio *serio)
+{
+	struct uart_sunzilog_port *up = serio->port_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sunzilog_serio_lock, flags);
+	up->serio_open = 0;
+	spin_unlock_irqrestore(&sunzilog_serio_lock, flags);
+}
+
+#endif /* CONFIG_SERIO */
+
+#ifdef CONFIG_SERIAL_SUNZILOG_CONSOLE
+static void
+sunzilog_console_write(struct console *con, const char *s, unsigned int count)
+{
+	struct uart_sunzilog_port *up = &sunzilog_port_table[con->index];
+	unsigned long flags;
+	int locked = 1;
+
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
+
+	uart_console_write(&up->port, s, count, sunzilog_putchar);
+	udelay(2);
+
+	if (locked)
+		spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init sunzilog_console_setup(struct console *con, char *options)
+{
+	struct uart_sunzilog_port *up = &sunzilog_port_table[con->index];
+	unsigned long flags;
+	int baud, brg;
+
+	if (up->port.type != PORT_SUNZILOG)
+		return -EINVAL;
+
+	printk(KERN_INFO "Console: ttyS%d (SunZilog zs%d)\n",
+	       (sunzilog_reg.minor - 64) + con->index, con->index);
+
+	/* Get firmware console settings.  */
+	sunserial_console_termios(con, up->port.dev->of_node);
+
+	/* Firmware console speed is limited to 150-->38400 baud so
+	 * this hackish cflag thing is OK.
+	 */
+	switch (con->cflag & CBAUD) {
+	case B150: baud = 150; break;
+	case B300: baud = 300; break;
+	case B600: baud = 600; break;
+	case B1200: baud = 1200; break;
+	case B2400: baud = 2400; break;
+	case B4800: baud = 4800; break;
+	default: case B9600: baud = 9600; break;
+	case B19200: baud = 19200; break;
+	case B38400: baud = 38400; break;
+	}
+
+	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->curregs[R15] |= BRKIE;
+	sunzilog_convert_to_zs(up, con->cflag, 0, brg);
+
+	sunzilog_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
+	__sunzilog_startup(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return 0;
+}
+
+static struct console sunzilog_console_ops = {
+	.name	=	"ttyS",
+	.write	=	sunzilog_console_write,
+	.device	=	uart_console_device,
+	.setup	=	sunzilog_console_setup,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data   =	&sunzilog_reg,
+};
+
+static inline struct console *SUNZILOG_CONSOLE(void)
+{
+	return &sunzilog_console_ops;
+}
+
+#else
+#define SUNZILOG_CONSOLE()	(NULL)
+#endif
+
+static void sunzilog_init_kbdms(struct uart_sunzilog_port *up)
+{
+	int baud, brg;
+
+	if (up->flags & SUNZILOG_FLAG_CONS_KEYB) {
+		up->cflag = B1200 | CS8 | CLOCAL | CREAD;
+		baud = 1200;
+	} else {
+		up->cflag = B4800 | CS8 | CLOCAL | CREAD;
+		baud = 4800;
+	}
+
+	up->curregs[R15] |= BRKIE;
+	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+	sunzilog_convert_to_zs(up, up->cflag, 0, brg);
+	sunzilog_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
+	__sunzilog_startup(up);
+}
+
+#ifdef CONFIG_SERIO
+static void sunzilog_register_serio(struct uart_sunzilog_port *up)
+{
+	struct serio *serio = &up->serio;
+
+	serio->port_data = up;
+
+	serio->id.type = SERIO_RS232;
+	if (up->flags & SUNZILOG_FLAG_CONS_KEYB) {
+		serio->id.proto = SERIO_SUNKBD;
+		strscpy(serio->name, "zskbd", sizeof(serio->name));
+	} else {
+		serio->id.proto = SERIO_SUN;
+		serio->id.extra = 1;
+		strscpy(serio->name, "zsms", sizeof(serio->name));
+	}
+	strscpy(serio->phys,
+		((up->flags & SUNZILOG_FLAG_CONS_KEYB) ?
+		 "zs/serio0" : "zs/serio1"),
+		sizeof(serio->phys));
+
+	serio->write = sunzilog_serio_write;
+	serio->open = sunzilog_serio_open;
+	serio->close = sunzilog_serio_close;
+	serio->dev.parent = up->port.dev;
+
+	serio_register_port(serio);
+}
+#endif
+
+static void sunzilog_init_hw(struct uart_sunzilog_port *up)
+{
+	struct zilog_channel __iomem *channel;
+	unsigned long flags;
+	int baud, brg;
+
+	channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (ZS_IS_CHANNEL_A(up)) {
+		write_zsreg(channel, R9, FHWRES);
+		ZSDELAY_LONG();
+		(void) read_zsreg(channel, R0);
+	}
+
+	if (up->flags & (SUNZILOG_FLAG_CONS_KEYB |
+			 SUNZILOG_FLAG_CONS_MOUSE)) {
+		up->curregs[R1] = EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+		up->curregs[R4] = PAR_EVEN | X16CLK | SB1;
+		up->curregs[R3] = RxENAB | Rx8;
+		up->curregs[R5] = TxENAB | Tx8;
+		up->curregs[R6] = 0x00; /* SDLC Address */
+		up->curregs[R7] = 0x7E; /* SDLC Flag    */
+		up->curregs[R9] = NV;
+		up->curregs[R7p] = 0x00;
+		sunzilog_init_kbdms(up);
+		/* Only enable interrupts if an ISR handler available */
+		if (up->flags & SUNZILOG_FLAG_ISR_HANDLER)
+			up->curregs[R9] |= MIE;
+		write_zsreg(channel, R9, up->curregs[R9]);
+	} else {
+		/* Normal serial TTY. */
+		up->parity_mask = 0xff;
+		up->curregs[R1] = EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
+		up->curregs[R4] = PAR_EVEN | X16CLK | SB1;
+		up->curregs[R3] = RxENAB | Rx8;
+		up->curregs[R5] = TxENAB | Tx8;
+		up->curregs[R6] = 0x00; /* SDLC Address */
+		up->curregs[R7] = 0x7E; /* SDLC Flag    */
+		up->curregs[R9] = NV;
+		up->curregs[R10] = NRZ;
+		up->curregs[R11] = TCBR | RCBR;
+		baud = 9600;
+		brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
+		up->curregs[R12] = (brg & 0xff);
+		up->curregs[R13] = (brg >> 8) & 0xff;
+		up->curregs[R14] = BRSRC | BRENAB;
+		up->curregs[R15] = FIFOEN; /* Use FIFO if on ESCC */
+		up->curregs[R7p] = TxFIFO_LVL | RxFIFO_LVL;
+		if (__load_zsregs(channel, up->curregs)) {
+			up->flags |= SUNZILOG_FLAG_ESCC;
+		}
+		/* Only enable interrupts if an ISR handler available */
+		if (up->flags & SUNZILOG_FLAG_ISR_HANDLER)
+			up->curregs[R9] |= MIE;
+		write_zsreg(channel, R9, up->curregs[R9]);
+	}
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+#ifdef CONFIG_SERIO
+	if (up->flags & (SUNZILOG_FLAG_CONS_KEYB |
+			 SUNZILOG_FLAG_CONS_MOUSE))
+		sunzilog_register_serio(up);
+#endif
+}
+
+static int zilog_irq;
+
+static int zs_probe(struct platform_device *op)
+{
+	static int kbm_inst, uart_inst;
+	int inst;
+	struct uart_sunzilog_port *up;
+	struct zilog_layout __iomem *rp;
+	int keyboard_mouse = 0;
+	int err;
+
+	if (of_property_present(op->dev.of_node, "keyboard"))
+		keyboard_mouse = 1;
+
+	/* uarts must come before keyboards/mice */
+	if (keyboard_mouse)
+		inst = uart_chip_count + kbm_inst;
+	else
+		inst = uart_inst;
+
+	sunzilog_chip_regs[inst] = of_ioremap(&op->resource[0], 0,
+					      sizeof(struct zilog_layout),
+					      "zs");
+	if (!sunzilog_chip_regs[inst])
+		return -ENOMEM;
+
+	rp = sunzilog_chip_regs[inst];
+
+	if (!zilog_irq)
+		zilog_irq = op->archdata.irqs[0];
+
+	up = &sunzilog_port_table[inst * 2];
+
+	/* Channel A */
+	up[0].port.mapbase = op->resource[0].start + 0x00;
+	up[0].port.membase = (void __iomem *) &rp->channelA;
+	up[0].port.iotype = UPIO_MEM;
+	up[0].port.irq = op->archdata.irqs[0];
+	up[0].port.uartclk = ZS_CLOCK;
+	up[0].port.fifosize = 1;
+	up[0].port.ops = &sunzilog_pops;
+	up[0].port.type = PORT_SUNZILOG;
+	up[0].port.flags = 0;
+	up[0].port.line = (inst * 2) + 0;
+	up[0].port.dev = &op->dev;
+	up[0].flags |= SUNZILOG_FLAG_IS_CHANNEL_A;
+	up[0].port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNZILOG_CONSOLE);
+	if (keyboard_mouse)
+		up[0].flags |= SUNZILOG_FLAG_CONS_KEYB;
+	sunzilog_init_hw(&up[0]);
+
+	/* Channel B */
+	up[1].port.mapbase = op->resource[0].start + 0x04;
+	up[1].port.membase = (void __iomem *) &rp->channelB;
+	up[1].port.iotype = UPIO_MEM;
+	up[1].port.irq = op->archdata.irqs[0];
+	up[1].port.uartclk = ZS_CLOCK;
+	up[1].port.fifosize = 1;
+	up[1].port.ops = &sunzilog_pops;
+	up[1].port.type = PORT_SUNZILOG;
+	up[1].port.flags = 0;
+	up[1].port.line = (inst * 2) + 1;
+	up[1].port.dev = &op->dev;
+	up[1].flags |= 0;
+	up[1].port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNZILOG_CONSOLE);
+	if (keyboard_mouse)
+		up[1].flags |= SUNZILOG_FLAG_CONS_MOUSE;
+	sunzilog_init_hw(&up[1]);
+
+	if (!keyboard_mouse) {
+		if (sunserial_console_match(SUNZILOG_CONSOLE(), op->dev.of_node,
+					    &sunzilog_reg, up[0].port.line,
+					    false))
+			up->flags |= SUNZILOG_FLAG_IS_CONS;
+		err = uart_add_one_port(&sunzilog_reg, &up[0].port);
+		if (err) {
+			of_iounmap(&op->resource[0],
+				   rp, sizeof(struct zilog_layout));
+			return err;
+		}
+		if (sunserial_console_match(SUNZILOG_CONSOLE(), op->dev.of_node,
+					    &sunzilog_reg, up[1].port.line,
+					    false))
+			up->flags |= SUNZILOG_FLAG_IS_CONS;
+		err = uart_add_one_port(&sunzilog_reg, &up[1].port);
+		if (err) {
+			uart_remove_one_port(&sunzilog_reg, &up[0].port);
+			of_iounmap(&op->resource[0],
+				   rp, sizeof(struct zilog_layout));
+			return err;
+		}
+		uart_inst++;
+	} else {
+		printk(KERN_INFO "%s: Keyboard at MMIO 0x%llx (irq = %d) "
+		       "is a %s\n",
+		       dev_name(&op->dev),
+		       (unsigned long long) up[0].port.mapbase,
+		       op->archdata.irqs[0], sunzilog_type(&up[0].port));
+		printk(KERN_INFO "%s: Mouse at MMIO 0x%llx (irq = %d) "
+		       "is a %s\n",
+		       dev_name(&op->dev),
+		       (unsigned long long) up[1].port.mapbase,
+		       op->archdata.irqs[0], sunzilog_type(&up[1].port));
+		kbm_inst++;
+	}
+
+	platform_set_drvdata(op, &up[0]);
+
+	return 0;
+}
+
+static void zs_remove_one(struct uart_sunzilog_port *up)
+{
+	if (ZS_IS_KEYB(up) || ZS_IS_MOUSE(up)) {
+#ifdef CONFIG_SERIO
+		serio_unregister_port(&up->serio);
+#endif
+	} else
+		uart_remove_one_port(&sunzilog_reg, &up->port);
+}
+
+static int zs_remove(struct platform_device *op)
+{
+	struct uart_sunzilog_port *up = platform_get_drvdata(op);
+	struct zilog_layout __iomem *regs;
+
+	zs_remove_one(&up[0]);
+	zs_remove_one(&up[1]);
+
+	regs = sunzilog_chip_regs[up[0].port.line / 2];
+	of_iounmap(&op->resource[0], regs, sizeof(struct zilog_layout));
+
+	return 0;
+}
+
+static const struct of_device_id zs_match[] = {
+	{
+		.name = "zs",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, zs_match);
+
+static struct platform_driver zs_driver = {
+	.driver = {
+		.name = "zs",
+		.of_match_table = zs_match,
+	},
+	.probe		= zs_probe,
+	.remove		= zs_remove,
+};
+
+static int __init sunzilog_init(void)
+{
+	struct device_node *dp;
+	int err;
+	int num_keybms = 0;
+	int num_sunzilog = 0;
+
+	for_each_node_by_name(dp, "zs") {
+		num_sunzilog++;
+		if (of_property_present(dp, "keyboard"))
+			num_keybms++;
+	}
+
+	if (num_sunzilog) {
+		err = sunzilog_alloc_tables(num_sunzilog);
+		if (err)
+			goto out;
+
+		uart_chip_count = num_sunzilog - num_keybms;
+
+		err = sunserial_register_minors(&sunzilog_reg,
+						uart_chip_count * 2);
+		if (err)
+			goto out_free_tables;
+	}
+
+	err = platform_driver_register(&zs_driver);
+	if (err)
+		goto out_unregister_uart;
+
+	if (zilog_irq) {
+		struct uart_sunzilog_port *up = sunzilog_irq_chain;
+		err = request_irq(zilog_irq, sunzilog_interrupt, IRQF_SHARED,
+				  "zs", sunzilog_irq_chain);
+		if (err)
+			goto out_unregister_driver;
+
+		/* Enable Interrupts */
+		while (up) {
+			struct zilog_channel __iomem *channel;
+
+			/* printk (KERN_INFO "Enable IRQ for ZILOG Hardware %p\n", up); */
+			channel          = ZILOG_CHANNEL_FROM_PORT(&up->port);
+			up->flags       |= SUNZILOG_FLAG_ISR_HANDLER;
+			up->curregs[R9] |= MIE;
+			write_zsreg(channel, R9, up->curregs[R9]);
+			up = up->next;
+		}
+	}
+
+out:
+	return err;
+
+out_unregister_driver:
+	platform_driver_unregister(&zs_driver);
+
+out_unregister_uart:
+	if (num_sunzilog) {
+		sunserial_unregister_minors(&sunzilog_reg, num_sunzilog);
+		sunzilog_reg.cons = NULL;
+	}
+
+out_free_tables:
+	sunzilog_free_tables();
+	goto out;
+}
+
+static void __exit sunzilog_exit(void)
+{
+	platform_driver_unregister(&zs_driver);
+
+	if (zilog_irq) {
+		struct uart_sunzilog_port *up = sunzilog_irq_chain;
+
+		/* Disable Interrupts */
+		while (up) {
+			struct zilog_channel __iomem *channel;
+
+			/* printk (KERN_INFO "Disable IRQ for ZILOG Hardware %p\n", up); */
+			channel          = ZILOG_CHANNEL_FROM_PORT(&up->port);
+			up->flags       &= ~SUNZILOG_FLAG_ISR_HANDLER;
+			up->curregs[R9] &= ~MIE;
+			write_zsreg(channel, R9, up->curregs[R9]);
+			up = up->next;
+		}
+
+		free_irq(zilog_irq, sunzilog_irq_chain);
+		zilog_irq = 0;
+	}
+
+	if (sunzilog_reg.nr) {
+		sunserial_unregister_minors(&sunzilog_reg, sunzilog_reg.nr);
+		sunzilog_free_tables();
+	}
+}
+
+module_init(sunzilog_init);
+module_exit(sunzilog_exit);
+
+MODULE_AUTHOR("David S. Miller");
+MODULE_DESCRIPTION("Sun Zilog serial port driver");
+MODULE_VERSION("2.0");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/sunzilog.h b/drivers/tty/serial/sunzilog.h
new file mode 100644
index 000000000..6d6764f0a
--- /dev/null
+++ b/drivers/tty/serial/sunzilog.h
@@ -0,0 +1,290 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SUNZILOG_H
+#define _SUNZILOG_H
+
+struct zilog_channel {
+	volatile unsigned char control;
+	volatile unsigned char __pad1;
+	volatile unsigned char data;
+	volatile unsigned char __pad2;
+};
+
+struct zilog_layout {
+	struct zilog_channel channelB;
+	struct zilog_channel channelA;
+};
+
+#define	NUM_ZSREGS	17
+#define	R7p		16 /* Written as R7 with P15 bit 0 set */
+
+/* Conversion routines to/from brg time constants from/to bits
+ * per second.
+ */
+#define BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
+#define BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)
+
+/* The Zilog register set */
+
+#define	FLAG	0x7e
+
+/* Write Register 0 */
+#define	R0	0		/* Register selects */
+#define	R1	1
+#define	R2	2
+#define	R3	3
+#define	R4	4
+#define	R5	5
+#define	R6	6
+#define	R7	7
+#define	R8	8
+#define	R9	9
+#define	R10	10
+#define	R11	11
+#define	R12	12
+#define	R13	13
+#define	R14	14
+#define	R15	15
+
+#define	NULLCODE	0	/* Null Code */
+#define	POINT_HIGH	0x8	/* Select upper half of registers */
+#define	RES_EXT_INT	0x10	/* Reset Ext. Status Interrupts */
+#define	SEND_ABORT	0x18	/* HDLC Abort */
+#define	RES_RxINT_FC	0x20	/* Reset RxINT on First Character */
+#define	RES_Tx_P	0x28	/* Reset TxINT Pending */
+#define	ERR_RES		0x30	/* Error Reset */
+#define	RES_H_IUS	0x38	/* Reset highest IUS */
+
+#define	RES_Rx_CRC	0x40	/* Reset Rx CRC Checker */
+#define	RES_Tx_CRC	0x80	/* Reset Tx CRC Checker */
+#define	RES_EOM_L	0xC0	/* Reset EOM latch */
+
+/* Write Register 1 */
+
+#define	EXT_INT_ENAB	0x1	/* Ext Int Enable */
+#define	TxINT_ENAB	0x2	/* Tx Int Enable */
+#define	PAR_SPEC	0x4	/* Parity is special condition */
+
+#define	RxINT_DISAB	0	/* Rx Int Disable */
+#define	RxINT_FCERR	0x8	/* Rx Int on First Character Only or Error */
+#define	INT_ALL_Rx	0x10	/* Int on all Rx Characters or error */
+#define	INT_ERR_Rx	0x18	/* Int on error only */
+#define RxINT_MASK	0x18
+
+#define	WT_RDY_RT	0x20	/* Wait/Ready on R/T */
+#define	WT_FN_RDYFN	0x40	/* Wait/FN/Ready FN */
+#define	WT_RDY_ENAB	0x80	/* Wait/Ready Enable */
+
+/* Write Register #2 (Interrupt Vector) */
+
+/* Write Register 3 */
+
+#define	RxENAB  	0x1	/* Rx Enable */
+#define	SYNC_L_INH	0x2	/* Sync Character Load Inhibit */
+#define	ADD_SM		0x4	/* Address Search Mode (SDLC) */
+#define	RxCRC_ENAB	0x8	/* Rx CRC Enable */
+#define	ENT_HM		0x10	/* Enter Hunt Mode */
+#define	AUTO_ENAB	0x20	/* Auto Enables */
+#define	Rx5		0x0	/* Rx 5 Bits/Character */
+#define	Rx7		0x40	/* Rx 7 Bits/Character */
+#define	Rx6		0x80	/* Rx 6 Bits/Character */
+#define	Rx8		0xc0	/* Rx 8 Bits/Character */
+#define RxN_MASK	0xc0
+
+/* Write Register 4 */
+
+#define	PAR_ENAB	0x1	/* Parity Enable */
+#define	PAR_EVEN	0x2	/* Parity Even/Odd* */
+
+#define	SYNC_ENAB	0	/* Sync Modes Enable */
+#define	SB1		0x4	/* 1 stop bit/char */
+#define	SB15		0x8	/* 1.5 stop bits/char */
+#define	SB2		0xc	/* 2 stop bits/char */
+
+#define	MONSYNC		0	/* 8 Bit Sync character */
+#define	BISYNC		0x10	/* 16 bit sync character */
+#define	SDLC		0x20	/* SDLC Mode (01111110 Sync Flag) */
+#define	EXTSYNC		0x30	/* External Sync Mode */
+
+#define	X1CLK		0x0	/* x1 clock mode */
+#define	X16CLK		0x40	/* x16 clock mode */
+#define	X32CLK		0x80	/* x32 clock mode */
+#define	X64CLK		0xC0	/* x64 clock mode */
+#define XCLK_MASK	0xC0
+
+/* Write Register 5 */
+
+#define	TxCRC_ENAB	0x1	/* Tx CRC Enable */
+#define	RTS		0x2	/* RTS */
+#define	SDLC_CRC	0x4	/* SDLC/CRC-16 */
+#define	TxENAB		0x8	/* Tx Enable */
+#define	SND_BRK		0x10	/* Send Break */
+#define	Tx5		0x0	/* Tx 5 bits (or less)/character */
+#define	Tx7		0x20	/* Tx 7 bits/character */
+#define	Tx6		0x40	/* Tx 6 bits/character */
+#define	Tx8		0x60	/* Tx 8 bits/character */
+#define TxN_MASK	0x60
+#define	DTR		0x80	/* DTR */
+
+/* Write Register 6 (Sync bits 0-7/SDLC Address Field) */
+
+/* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
+
+/* Write Register 7' (ESCC Only) */
+#define	AUTO_TxFLAG	1	/* Automatic Tx SDLC Flag */
+#define	AUTO_EOM_RST	2	/* Automatic EOM Reset */
+#define	AUTOnRTS	4	/* Automatic /RTS pin deactivation */
+#define	RxFIFO_LVL	8	/* Receive FIFO interrupt level */
+#define	nDTRnREQ	0x10	/* /DTR/REQ timing */
+#define	TxFIFO_LVL	0x20	/* Transmit FIFO interrupt level */
+#define	EXT_RD_EN	0x40	/* Extended read register enable */
+
+/* Write Register 8 (transmit buffer) */
+
+/* Write Register 9 (Master interrupt control) */
+#define	VIS	1	/* Vector Includes Status */
+#define	NV	2	/* No Vector */
+#define	DLC	4	/* Disable Lower Chain */
+#define	MIE	8	/* Master Interrupt Enable */
+#define	STATHI	0x10	/* Status high */
+#define	SWIACK  0x20    /* Software Interrupt Ack (not on NMOS) */
+#define	NORESET	0	/* No reset on write to R9 */
+#define	CHRB	0x40	/* Reset channel B */
+#define	CHRA	0x80	/* Reset channel A */
+#define	FHWRES	0xc0	/* Force hardware reset */
+
+/* Write Register 10 (misc control bits) */
+#define	BIT6	1	/* 6 bit/8bit sync */
+#define	LOOPMODE 2	/* SDLC Loop mode */
+#define	ABUNDER	4	/* Abort/flag on SDLC xmit underrun */
+#define	MARKIDLE 8	/* Mark/flag on idle */
+#define	GAOP	0x10	/* Go active on poll */
+#define	NRZ	0	/* NRZ mode */
+#define	NRZI	0x20	/* NRZI mode */
+#define	FM1	0x40	/* FM1 (transition = 1) */
+#define	FM0	0x60	/* FM0 (transition = 0) */
+#define	CRCPS	0x80	/* CRC Preset I/O */
+
+/* Write Register 11 (Clock Mode control) */
+#define	TRxCXT	0	/* TRxC = Xtal output */
+#define	TRxCTC	1	/* TRxC = Transmit clock */
+#define	TRxCBR	2	/* TRxC = BR Generator Output */
+#define	TRxCDP	3	/* TRxC = DPLL output */
+#define	TRxCOI	4	/* TRxC O/I */
+#define	TCRTxCP	0	/* Transmit clock = RTxC pin */
+#define	TCTRxCP	8	/* Transmit clock = TRxC pin */
+#define	TCBR	0x10	/* Transmit clock = BR Generator output */
+#define	TCDPLL	0x18	/* Transmit clock = DPLL output */
+#define	RCRTxCP	0	/* Receive clock = RTxC pin */
+#define	RCTRxCP	0x20	/* Receive clock = TRxC pin */
+#define	RCBR	0x40	/* Receive clock = BR Generator output */
+#define	RCDPLL	0x60	/* Receive clock = DPLL output */
+#define	RTxCX	0x80	/* RTxC Xtal/No Xtal */
+
+/* Write Register 12 (lower byte of baud rate generator time constant) */
+
+/* Write Register 13 (upper byte of baud rate generator time constant) */
+
+/* Write Register 14 (Misc control bits) */
+#define	BRENAB 	1	/* Baud rate generator enable */
+#define	BRSRC	2	/* Baud rate generator source */
+#define	DTRREQ	4	/* DTR/Request function */
+#define	AUTOECHO 8	/* Auto Echo */
+#define	LOOPBAK	0x10	/* Local loopback */
+#define	SEARCH	0x20	/* Enter search mode */
+#define	RMC	0x40	/* Reset missing clock */
+#define	DISDPLL	0x60	/* Disable DPLL */
+#define	SSBR	0x80	/* Set DPLL source = BR generator */
+#define	SSRTxC	0xa0	/* Set DPLL source = RTxC */
+#define	SFMM	0xc0	/* Set FM mode */
+#define	SNRZI	0xe0	/* Set NRZI mode */
+
+/* Write Register 15 (external/status interrupt control) */
+#define	WR7pEN	1	/* WR7' Enable (ESCC only) */
+#define	ZCIE	2	/* Zero count IE */
+#define	FIFOEN	4	/* FIFO Enable (ESCC only) */
+#define	DCDIE	8	/* DCD IE */
+#define	SYNCIE	0x10	/* Sync/hunt IE */
+#define	CTSIE	0x20	/* CTS IE */
+#define	TxUIE	0x40	/* Tx Underrun/EOM IE */
+#define	BRKIE	0x80	/* Break/Abort IE */
+
+
+/* Read Register 0 */
+#define	Rx_CH_AV	0x1	/* Rx Character Available */
+#define	ZCOUNT		0x2	/* Zero count */
+#define	Tx_BUF_EMP	0x4	/* Tx Buffer empty */
+#define	DCD		0x8	/* DCD */
+#define	SYNC		0x10	/* Sync/hunt */
+#define	CTS		0x20	/* CTS */
+#define	TxEOM		0x40	/* Tx underrun */
+#define	BRK_ABRT	0x80	/* Break/Abort */
+
+/* Read Register 1 */
+#define	ALL_SNT		0x1	/* All sent */
+/* Residue Data for 8 Rx bits/char programmed */
+#define	RES3		0x8	/* 0/3 */
+#define	RES4		0x4	/* 0/4 */
+#define	RES5		0xc	/* 0/5 */
+#define	RES6		0x2	/* 0/6 */
+#define	RES7		0xa	/* 0/7 */
+#define	RES8		0x6	/* 0/8 */
+#define	RES18		0xe	/* 1/8 */
+#define	RES28		0x0	/* 2/8 */
+/* Special Rx Condition Interrupts */
+#define	PAR_ERR		0x10	/* Parity error */
+#define	Rx_OVR		0x20	/* Rx Overrun Error */
+#define	CRC_ERR		0x40	/* CRC/Framing Error */
+#define	END_FR		0x80	/* End of Frame (SDLC) */
+
+/* Read Register 2 (channel b only) - Interrupt vector */
+#define CHB_Tx_EMPTY	0x00
+#define CHB_EXT_STAT	0x02
+#define CHB_Rx_AVAIL	0x04
+#define CHB_SPECIAL	0x06
+#define CHA_Tx_EMPTY	0x08
+#define CHA_EXT_STAT	0x0a
+#define CHA_Rx_AVAIL	0x0c
+#define CHA_SPECIAL	0x0e
+#define STATUS_MASK	0x0e
+
+/* Read Register 3 (interrupt pending register) ch a only */
+#define	CHBEXT	0x1		/* Channel B Ext/Stat IP */
+#define	CHBTxIP	0x2		/* Channel B Tx IP */
+#define	CHBRxIP	0x4		/* Channel B Rx IP */
+#define	CHAEXT	0x8		/* Channel A Ext/Stat IP */
+#define	CHATxIP	0x10		/* Channel A Tx IP */
+#define	CHARxIP	0x20		/* Channel A Rx IP */
+
+/* Read Register 6 (LSB frame byte count [Not on NMOS]) */
+
+/* Read Register 7 (MSB frame byte count and FIFO status [Not on NMOS]) */
+
+/* Read Register 8 (receive data register) */
+
+/* Read Register 10  (misc status bits) */
+#define	ONLOOP	2		/* On loop */
+#define	LOOPSEND 0x10		/* Loop sending */
+#define	CLK2MIS	0x40		/* Two clocks missing */
+#define	CLK1MIS	0x80		/* One clock missing */
+
+/* Read Register 12 (lower byte of baud rate generator constant) */
+
+/* Read Register 13 (upper byte of baud rate generator constant) */
+
+/* Read Register 15 (value of WR 15) */
+
+/* Misc macros */
+#define ZS_CLEARERR(channel)    do { sbus_writeb(ERR_RES, &channel->control); \
+				     udelay(5); } while(0)
+
+#define ZS_CLEARSTAT(channel)   do { sbus_writeb(RES_EXT_INT, &channel->control); \
+				     udelay(5); } while(0)
+
+#define ZS_CLEARFIFO(channel)   do { sbus_readb(&channel->data); \
+				     udelay(2); \
+				     sbus_readb(&channel->data); \
+				     udelay(2); \
+				     sbus_readb(&channel->data); \
+				     udelay(2); } while(0)
+
+#endif /* _SUNZILOG_H */
diff --git a/drivers/tty/serial/tegra-tcu.c b/drivers/tty/serial/tegra-tcu.c
new file mode 100644
index 000000000..65069daf3
--- /dev/null
+++ b/drivers/tty/serial/tegra-tcu.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/console.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define TCU_MBOX_BYTE(i, x)			((x) << (i * 8))
+#define TCU_MBOX_BYTE_V(x, i)			(((x) >> (i * 8)) & 0xff)
+#define TCU_MBOX_NUM_BYTES(x)			((x) << 24)
+#define TCU_MBOX_NUM_BYTES_V(x)			(((x) >> 24) & 0x3)
+
+struct tegra_tcu {
+	struct uart_driver driver;
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
+	struct console console;
+#endif
+	struct uart_port port;
+
+	struct mbox_client tx_client, rx_client;
+	struct mbox_chan *tx, *rx;
+};
+
+static unsigned int tegra_tcu_uart_tx_empty(struct uart_port *port)
+{
+	return TIOCSER_TEMT;
+}
+
+static void tegra_tcu_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int tegra_tcu_uart_get_mctrl(struct uart_port *port)
+{
+	return 0;
+}
+
+static void tegra_tcu_uart_stop_tx(struct uart_port *port)
+{
+}
+
+static void tegra_tcu_write_one(struct tegra_tcu *tcu, u32 value,
+				unsigned int count)
+{
+	void *msg;
+
+	value |= TCU_MBOX_NUM_BYTES(count);
+	msg = (void *)(unsigned long)value;
+	mbox_send_message(tcu->tx, msg);
+	mbox_flush(tcu->tx, 1000);
+}
+
+static void tegra_tcu_write(struct tegra_tcu *tcu, const char *s,
+			    unsigned int count)
+{
+	unsigned int written = 0, i = 0;
+	bool insert_nl = false;
+	u32 value = 0;
+
+	while (i < count) {
+		if (insert_nl) {
+			value |= TCU_MBOX_BYTE(written++, '\n');
+			insert_nl = false;
+			i++;
+		} else if (s[i] == '\n') {
+			value |= TCU_MBOX_BYTE(written++, '\r');
+			insert_nl = true;
+		} else {
+			value |= TCU_MBOX_BYTE(written++, s[i++]);
+		}
+
+		if (written == 3) {
+			tegra_tcu_write_one(tcu, value, 3);
+			value = written = 0;
+		}
+	}
+
+	if (written)
+		tegra_tcu_write_one(tcu, value, written);
+}
+
+static void tegra_tcu_uart_start_tx(struct uart_port *port)
+{
+	struct tegra_tcu *tcu = port->private_data;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long count;
+
+	for (;;) {
+		count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+		if (!count)
+			break;
+
+		tegra_tcu_write(tcu, &xmit->buf[xmit->tail], count);
+		uart_xmit_advance(port, count);
+	}
+
+	uart_write_wakeup(port);
+}
+
+static void tegra_tcu_uart_stop_rx(struct uart_port *port)
+{
+}
+
+static void tegra_tcu_uart_break_ctl(struct uart_port *port, int ctl)
+{
+}
+
+static int tegra_tcu_uart_startup(struct uart_port *port)
+{
+	return 0;
+}
+
+static void tegra_tcu_uart_shutdown(struct uart_port *port)
+{
+}
+
+static void tegra_tcu_uart_set_termios(struct uart_port *port,
+				       struct ktermios *new,
+				       const struct ktermios *old)
+{
+}
+
+static const struct uart_ops tegra_tcu_uart_ops = {
+	.tx_empty = tegra_tcu_uart_tx_empty,
+	.set_mctrl = tegra_tcu_uart_set_mctrl,
+	.get_mctrl = tegra_tcu_uart_get_mctrl,
+	.stop_tx = tegra_tcu_uart_stop_tx,
+	.start_tx = tegra_tcu_uart_start_tx,
+	.stop_rx = tegra_tcu_uart_stop_rx,
+	.break_ctl = tegra_tcu_uart_break_ctl,
+	.startup = tegra_tcu_uart_startup,
+	.shutdown = tegra_tcu_uart_shutdown,
+	.set_termios = tegra_tcu_uart_set_termios,
+};
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
+static void tegra_tcu_console_write(struct console *cons, const char *s,
+				    unsigned int count)
+{
+	struct tegra_tcu *tcu = container_of(cons, struct tegra_tcu, console);
+
+	tegra_tcu_write(tcu, s, count);
+}
+
+static int tegra_tcu_console_setup(struct console *cons, char *options)
+{
+	return 0;
+}
+#endif
+
+static void tegra_tcu_receive(struct mbox_client *cl, void *msg)
+{
+	struct tegra_tcu *tcu = container_of(cl, struct tegra_tcu, rx_client);
+	struct tty_port *port = &tcu->port.state->port;
+	u32 value = (u32)(unsigned long)msg;
+	unsigned int num_bytes, i;
+
+	num_bytes = TCU_MBOX_NUM_BYTES_V(value);
+
+	for (i = 0; i < num_bytes; i++)
+		tty_insert_flip_char(port, TCU_MBOX_BYTE_V(value, i),
+				     TTY_NORMAL);
+
+	tty_flip_buffer_push(port);
+}
+
+static int tegra_tcu_probe(struct platform_device *pdev)
+{
+	struct uart_port *port;
+	struct tegra_tcu *tcu;
+	int err;
+
+	tcu = devm_kzalloc(&pdev->dev, sizeof(*tcu), GFP_KERNEL);
+	if (!tcu)
+		return -ENOMEM;
+
+	tcu->tx_client.dev = &pdev->dev;
+	tcu->rx_client.dev = &pdev->dev;
+	tcu->rx_client.rx_callback = tegra_tcu_receive;
+
+	tcu->tx = mbox_request_channel_byname(&tcu->tx_client, "tx");
+	if (IS_ERR(tcu->tx)) {
+		err = PTR_ERR(tcu->tx);
+		dev_err(&pdev->dev, "failed to get tx mailbox: %d\n", err);
+		return err;
+	}
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
+	/* setup the console */
+	strcpy(tcu->console.name, "ttyTCU");
+	tcu->console.device = uart_console_device;
+	tcu->console.flags = CON_PRINTBUFFER | CON_ANYTIME;
+	tcu->console.index = -1;
+	tcu->console.write = tegra_tcu_console_write;
+	tcu->console.setup = tegra_tcu_console_setup;
+	tcu->console.data = &tcu->driver;
+#endif
+
+	/* setup the driver */
+	tcu->driver.owner = THIS_MODULE;
+	tcu->driver.driver_name = "tegra-tcu";
+	tcu->driver.dev_name = "ttyTCU";
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
+	tcu->driver.cons = &tcu->console;
+#endif
+	tcu->driver.nr = 1;
+
+	err = uart_register_driver(&tcu->driver);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register UART driver: %d\n",
+			err);
+		goto free_tx;
+	}
+
+	/* setup the port */
+	port = &tcu->port;
+	spin_lock_init(&port->lock);
+	port->dev = &pdev->dev;
+	port->type = PORT_TEGRA_TCU;
+	port->ops = &tegra_tcu_uart_ops;
+	port->fifosize = 1;
+	port->iotype = UPIO_MEM;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->private_data = tcu;
+
+	err = uart_add_one_port(&tcu->driver, port);
+	if (err) {
+		dev_err(&pdev->dev, "failed to add UART port: %d\n", err);
+		goto unregister_uart;
+	}
+
+	/*
+	 * Request RX channel after creating port to ensure tcu->port
+	 * is ready for any immediate incoming bytes.
+	 */
+	tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");
+	if (IS_ERR(tcu->rx)) {
+		err = PTR_ERR(tcu->rx);
+		dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);
+		goto remove_uart_port;
+	}
+
+	platform_set_drvdata(pdev, tcu);
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
+	register_console(&tcu->console);
+#endif
+
+	return 0;
+
+remove_uart_port:
+	uart_remove_one_port(&tcu->driver, &tcu->port);
+unregister_uart:
+	uart_unregister_driver(&tcu->driver);
+free_tx:
+	mbox_free_channel(tcu->tx);
+
+	return err;
+}
+
+static int tegra_tcu_remove(struct platform_device *pdev)
+{
+	struct tegra_tcu *tcu = platform_get_drvdata(pdev);
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
+	unregister_console(&tcu->console);
+#endif
+	mbox_free_channel(tcu->rx);
+	uart_remove_one_port(&tcu->driver, &tcu->port);
+	uart_unregister_driver(&tcu->driver);
+	mbox_free_channel(tcu->tx);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_tcu_match[] = {
+	{ .compatible = "nvidia,tegra194-tcu" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tegra_tcu_match);
+
+static struct platform_driver tegra_tcu_driver = {
+	.driver = {
+		.name = "tegra-tcu",
+		.of_match_table = tegra_tcu_match,
+	},
+	.probe = tegra_tcu_probe,
+	.remove = tegra_tcu_remove,
+};
+module_platform_driver(tegra_tcu_driver);
+
+MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("NVIDIA Tegra Combined UART driver");
diff --git a/drivers/tty/serial/timbuart.c b/drivers/tty/serial/timbuart.c
new file mode 100644
index 000000000..0859394a7
--- /dev/null
+++ b/drivers/tty/serial/timbuart.c
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * timbuart.c timberdale FPGA UART driver
+ * Copyright (c) 2009 Intel Corporation
+ */
+
+/* Supports:
+ * Timberdale FPGA UART
+ */
+
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "timbuart.h"
+
+struct timbuart_port {
+	struct uart_port	port;
+	struct tasklet_struct	tasklet;
+	int			usedma;
+	u32			last_ier;
+	struct platform_device  *dev;
+};
+
+static int baudrates[] = {9600, 19200, 38400, 57600, 115200, 230400, 460800,
+	921600, 1843200, 3250000};
+
+static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier);
+
+static irqreturn_t timbuart_handleinterrupt(int irq, void *devid);
+
+static void timbuart_stop_rx(struct uart_port *port)
+{
+	/* spin lock held by upper layer, disable all RX interrupts */
+	u32 ier = ioread32(port->membase + TIMBUART_IER) & ~RXFLAGS;
+	iowrite32(ier, port->membase + TIMBUART_IER);
+}
+
+static void timbuart_stop_tx(struct uart_port *port)
+{
+	/* spinlock held by upper layer, disable TX interrupt */
+	u32 ier = ioread32(port->membase + TIMBUART_IER) & ~TXBAE;
+	iowrite32(ier, port->membase + TIMBUART_IER);
+}
+
+static void timbuart_start_tx(struct uart_port *port)
+{
+	struct timbuart_port *uart =
+		container_of(port, struct timbuart_port, port);
+
+	/* do not transfer anything here -> fire off the tasklet */
+	tasklet_schedule(&uart->tasklet);
+}
+
+static unsigned int timbuart_tx_empty(struct uart_port *port)
+{
+	u32 isr = ioread32(port->membase + TIMBUART_ISR);
+
+	return (isr & TXBE) ? TIOCSER_TEMT : 0;
+}
+
+static void timbuart_flush_buffer(struct uart_port *port)
+{
+	if (!timbuart_tx_empty(port)) {
+		u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
+			TIMBUART_CTRL_FLSHTX;
+
+		iowrite8(ctl, port->membase + TIMBUART_CTRL);
+		iowrite32(TXBF, port->membase + TIMBUART_ISR);
+	}
+}
+
+static void timbuart_rx_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+
+	while (ioread32(port->membase + TIMBUART_ISR) & RXDP) {
+		u8 ch = ioread8(port->membase + TIMBUART_RXFIFO);
+		port->icount.rx++;
+		tty_insert_flip_char(tport, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(tport);
+
+	dev_dbg(port->dev, "%s - total read %d bytes\n",
+		__func__, port->icount.rx);
+}
+
+static void timbuart_tx_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+
+	while (!(ioread32(port->membase + TIMBUART_ISR) & TXBF) &&
+		!uart_circ_empty(xmit)) {
+		iowrite8(xmit->buf[xmit->tail],
+			port->membase + TIMBUART_TXFIFO);
+		uart_xmit_advance(port, 1);
+	}
+
+	dev_dbg(port->dev,
+		"%s - total written %d bytes, CTL: %x, RTS: %x, baud: %x\n",
+		 __func__,
+		port->icount.tx,
+		ioread8(port->membase + TIMBUART_CTRL),
+		port->mctrl & TIOCM_RTS,
+		ioread8(port->membase + TIMBUART_BAUDRATE));
+}
+
+static void timbuart_handle_tx_port(struct uart_port *port, u32 isr, u32 *ier)
+{
+	struct timbuart_port *uart =
+		container_of(port, struct timbuart_port, port);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return;
+
+	if (port->x_char)
+		return;
+
+	if (isr & TXFLAGS) {
+		timbuart_tx_chars(port);
+		/* clear all TX interrupts */
+		iowrite32(TXFLAGS, port->membase + TIMBUART_ISR);
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(port);
+	} else
+		/* Re-enable any tx interrupt */
+		*ier |= uart->last_ier & TXFLAGS;
+
+	/* enable interrupts if there are chars in the transmit buffer,
+	 * Or if we delivered some bytes and want the almost empty interrupt
+	 * we wake up the upper layer later when we got the interrupt
+	 * to give it some time to go out...
+	 */
+	if (!uart_circ_empty(xmit))
+		*ier |= TXBAE;
+
+	dev_dbg(port->dev, "%s - leaving\n", __func__);
+}
+
+static void timbuart_handle_rx_port(struct uart_port *port, u32 isr, u32 *ier)
+{
+	if (isr & RXFLAGS) {
+		/* Some RX status is set */
+		if (isr & RXBF) {
+			u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
+				TIMBUART_CTRL_FLSHRX;
+			iowrite8(ctl, port->membase + TIMBUART_CTRL);
+			port->icount.overrun++;
+		} else if (isr & (RXDP))
+			timbuart_rx_chars(port);
+
+		/* ack all RX interrupts */
+		iowrite32(RXFLAGS, port->membase + TIMBUART_ISR);
+	}
+
+	/* always have the RX interrupts enabled */
+	*ier |= RXBAF | RXBF | RXTT;
+
+	dev_dbg(port->dev, "%s - leaving\n", __func__);
+}
+
+static void timbuart_tasklet(struct tasklet_struct *t)
+{
+	struct timbuart_port *uart = from_tasklet(uart, t, tasklet);
+	u32 isr, ier = 0;
+
+	spin_lock(&uart->port.lock);
+
+	isr = ioread32(uart->port.membase + TIMBUART_ISR);
+	dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
+
+	if (!uart->usedma)
+		timbuart_handle_tx_port(&uart->port, isr, &ier);
+
+	timbuart_mctrl_check(&uart->port, isr, &ier);
+
+	if (!uart->usedma)
+		timbuart_handle_rx_port(&uart->port, isr, &ier);
+
+	iowrite32(ier, uart->port.membase + TIMBUART_IER);
+
+	spin_unlock(&uart->port.lock);
+	dev_dbg(uart->port.dev, "%s leaving\n", __func__);
+}
+
+static unsigned int timbuart_get_mctrl(struct uart_port *port)
+{
+	u8 cts = ioread8(port->membase + TIMBUART_CTRL);
+	dev_dbg(port->dev, "%s - cts %x\n", __func__, cts);
+
+	if (cts & TIMBUART_CTRL_CTS)
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+	else
+		return TIOCM_DSR | TIOCM_CAR;
+}
+
+static void timbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	dev_dbg(port->dev, "%s - %x\n", __func__, mctrl);
+
+	if (mctrl & TIOCM_RTS)
+		iowrite8(TIMBUART_CTRL_RTS, port->membase + TIMBUART_CTRL);
+	else
+		iowrite8(0, port->membase + TIMBUART_CTRL);
+}
+
+static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier)
+{
+	unsigned int cts;
+
+	if (isr & CTS_DELTA) {
+		/* ack */
+		iowrite32(CTS_DELTA, port->membase + TIMBUART_ISR);
+		cts = timbuart_get_mctrl(port);
+		uart_handle_cts_change(port, cts & TIOCM_CTS);
+		wake_up_interruptible(&port->state->port.delta_msr_wait);
+	}
+
+	*ier |= CTS_DELTA;
+}
+
+static void timbuart_break_ctl(struct uart_port *port, int ctl)
+{
+	/* N/A */
+}
+
+static int timbuart_startup(struct uart_port *port)
+{
+	struct timbuart_port *uart =
+		container_of(port, struct timbuart_port, port);
+
+	dev_dbg(port->dev, "%s\n", __func__);
+
+	iowrite8(TIMBUART_CTRL_FLSHRX, port->membase + TIMBUART_CTRL);
+	iowrite32(0x1ff, port->membase + TIMBUART_ISR);
+	/* Enable all but TX interrupts */
+	iowrite32(RXBAF | RXBF | RXTT | CTS_DELTA,
+		port->membase + TIMBUART_IER);
+
+	return request_irq(port->irq, timbuart_handleinterrupt, IRQF_SHARED,
+		"timb-uart", uart);
+}
+
+static void timbuart_shutdown(struct uart_port *port)
+{
+	struct timbuart_port *uart =
+		container_of(port, struct timbuart_port, port);
+	dev_dbg(port->dev, "%s\n", __func__);
+	free_irq(port->irq, uart);
+	iowrite32(0, port->membase + TIMBUART_IER);
+
+	timbuart_flush_buffer(port);
+}
+
+static int get_bindex(int baud)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(baudrates); i++)
+		if (baud <= baudrates[i])
+			return i;
+
+	return -1;
+}
+
+static void timbuart_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	unsigned int baud;
+	short bindex;
+	unsigned long flags;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+	bindex = get_bindex(baud);
+	dev_dbg(port->dev, "%s - bindex %d\n", __func__, bindex);
+
+	if (bindex < 0)
+		bindex = 0;
+	baud = baudrates[bindex];
+
+	/* The serial layer calls into this once with old = NULL when setting
+	   up initially */
+	if (old)
+		tty_termios_copy_hw(termios, old);
+	tty_termios_encode_baud_rate(termios, baud, baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+	iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
+	uart_update_timeout(port, termios->c_cflag, baud);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *timbuart_type(struct uart_port *port)
+{
+	return port->type == PORT_UNKNOWN ? "timbuart" : NULL;
+}
+
+/* We do not request/release mappings of the registers here,
+ * currently it's done in the proble function.
+ */
+static void timbuart_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	int size =
+		resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
+
+	if (port->flags & UPF_IOREMAP) {
+		iounmap(port->membase);
+		port->membase = NULL;
+	}
+
+	release_mem_region(port->mapbase, size);
+}
+
+static int timbuart_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	int size =
+		resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
+
+	if (!request_mem_region(port->mapbase, size, "timb-uart"))
+		return -EBUSY;
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = ioremap(port->mapbase, size);
+		if (port->membase == NULL) {
+			release_mem_region(port->mapbase, size);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+static irqreturn_t timbuart_handleinterrupt(int irq, void *devid)
+{
+	struct timbuart_port *uart = (struct timbuart_port *)devid;
+
+	if (ioread8(uart->port.membase + TIMBUART_IPR)) {
+		uart->last_ier = ioread32(uart->port.membase + TIMBUART_IER);
+
+		/* disable interrupts, the tasklet enables them again */
+		iowrite32(0, uart->port.membase + TIMBUART_IER);
+
+		/* fire off bottom half */
+		tasklet_schedule(&uart->tasklet);
+
+		return IRQ_HANDLED;
+	} else
+		return IRQ_NONE;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void timbuart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_TIMBUART;
+		timbuart_request_port(port);
+	}
+}
+
+static int timbuart_verify_port(struct uart_port *port,
+	struct serial_struct *ser)
+{
+	/* we don't want the core code to modify any port params */
+	return -EINVAL;
+}
+
+static const struct uart_ops timbuart_ops = {
+	.tx_empty = timbuart_tx_empty,
+	.set_mctrl = timbuart_set_mctrl,
+	.get_mctrl = timbuart_get_mctrl,
+	.stop_tx = timbuart_stop_tx,
+	.start_tx = timbuart_start_tx,
+	.flush_buffer = timbuart_flush_buffer,
+	.stop_rx = timbuart_stop_rx,
+	.break_ctl = timbuart_break_ctl,
+	.startup = timbuart_startup,
+	.shutdown = timbuart_shutdown,
+	.set_termios = timbuart_set_termios,
+	.type = timbuart_type,
+	.release_port = timbuart_release_port,
+	.request_port = timbuart_request_port,
+	.config_port = timbuart_config_port,
+	.verify_port = timbuart_verify_port
+};
+
+static struct uart_driver timbuart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "timberdale_uart",
+	.dev_name = "ttyTU",
+	.major = TIMBUART_MAJOR,
+	.minor = TIMBUART_MINOR,
+	.nr = 1
+};
+
+static int timbuart_probe(struct platform_device *dev)
+{
+	int err, irq;
+	struct timbuart_port *uart;
+	struct resource *iomem;
+
+	dev_dbg(&dev->dev, "%s\n", __func__);
+
+	uart = kzalloc(sizeof(*uart), GFP_KERNEL);
+	if (!uart) {
+		err = -EINVAL;
+		goto err_mem;
+	}
+
+	uart->usedma = 0;
+
+	uart->port.uartclk = 3250000 * 16;
+	uart->port.fifosize  = TIMBUART_FIFO_SIZE;
+	uart->port.regshift  = 2;
+	uart->port.iotype  = UPIO_MEM;
+	uart->port.ops = &timbuart_ops;
+	uart->port.irq = 0;
+	uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+	uart->port.line  = 0;
+	uart->port.dev	= &dev->dev;
+
+	iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!iomem) {
+		err = -ENOMEM;
+		goto err_register;
+	}
+	uart->port.mapbase = iomem->start;
+	uart->port.membase = NULL;
+
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0) {
+		err = -EINVAL;
+		goto err_register;
+	}
+	uart->port.irq = irq;
+
+	tasklet_setup(&uart->tasklet, timbuart_tasklet);
+
+	err = uart_register_driver(&timbuart_driver);
+	if (err)
+		goto err_register;
+
+	err = uart_add_one_port(&timbuart_driver, &uart->port);
+	if (err)
+		goto err_add_port;
+
+	platform_set_drvdata(dev, uart);
+
+	return 0;
+
+err_add_port:
+	uart_unregister_driver(&timbuart_driver);
+err_register:
+	kfree(uart);
+err_mem:
+	printk(KERN_ERR "timberdale: Failed to register Timberdale UART: %d\n",
+		err);
+
+	return err;
+}
+
+static int timbuart_remove(struct platform_device *dev)
+{
+	struct timbuart_port *uart = platform_get_drvdata(dev);
+
+	tasklet_kill(&uart->tasklet);
+	uart_remove_one_port(&timbuart_driver, &uart->port);
+	uart_unregister_driver(&timbuart_driver);
+	kfree(uart);
+
+	return 0;
+}
+
+static struct platform_driver timbuart_platform_driver = {
+	.driver = {
+		.name	= "timb-uart",
+	},
+	.probe		= timbuart_probe,
+	.remove		= timbuart_remove,
+};
+
+module_platform_driver(timbuart_platform_driver);
+
+MODULE_DESCRIPTION("Timberdale UART driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:timb-uart");
+
diff --git a/drivers/tty/serial/timbuart.h b/drivers/tty/serial/timbuart.h
new file mode 100644
index 000000000..007e59af6
--- /dev/null
+++ b/drivers/tty/serial/timbuart.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * timbuart.c timberdale FPGA GPIO driver
+ * Copyright (c) 2009 Intel Corporation
+ */
+
+/* Supports:
+ * Timberdale FPGA UART
+ */
+
+#ifndef _TIMBUART_H
+#define _TIMBUART_H
+
+#define TIMBUART_FIFO_SIZE	2048
+
+#define TIMBUART_RXFIFO		0x08
+#define TIMBUART_TXFIFO		0x0c
+#define TIMBUART_IER		0x10
+#define TIMBUART_IPR		0x14
+#define TIMBUART_ISR		0x18
+#define TIMBUART_CTRL		0x1c
+#define TIMBUART_BAUDRATE	0x20
+
+#define TIMBUART_CTRL_RTS	0x01
+#define TIMBUART_CTRL_CTS	0x02
+#define TIMBUART_CTRL_FLSHTX	0x40
+#define TIMBUART_CTRL_FLSHRX	0x80
+
+#define TXBF		0x01
+#define TXBAE		0x02
+#define CTS_DELTA	0x04
+#define RXDP		0x08
+#define RXBAF		0x10
+#define RXBF		0x20
+#define RXTT		0x40
+#define RXBNAE		0x80
+#define TXBE		0x100
+
+#define RXFLAGS (RXDP | RXBAF | RXBF | RXTT | RXBNAE)
+#define TXFLAGS (TXBF | TXBAE)
+
+#define TIMBUART_MAJOR 204
+#define TIMBUART_MINOR 192
+
+#endif /* _TIMBUART_H */
+
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
new file mode 100644
index 000000000..b225a78f6
--- /dev/null
+++ b/drivers/tty/serial/uartlite.c
@@ -0,0 +1,942 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * uartlite.c: Serial driver for Xilinx uartlite serial controller
+ *
+ * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
+ * Copyright (C) 2007 Secret Lab Technologies Ltd.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/bitfield.h>
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+
+#define ULITE_NAME		"ttyUL"
+#define ULITE_MAJOR		204
+#define ULITE_MINOR		187
+#define ULITE_NR_UARTS		CONFIG_SERIAL_UARTLITE_NR_UARTS
+
+/* ---------------------------------------------------------------------
+ * Register definitions
+ *
+ * For register details see datasheet:
+ * https://www.xilinx.com/support/documentation/ip_documentation/opb_uartlite.pdf
+ */
+
+#define ULITE_RX		0x00
+#define ULITE_TX		0x04
+#define ULITE_STATUS		0x08
+#define ULITE_CONTROL		0x0c
+
+#define ULITE_REGION		16
+
+#define ULITE_STATUS_RXVALID	0x01
+#define ULITE_STATUS_RXFULL	0x02
+#define ULITE_STATUS_TXEMPTY	0x04
+#define ULITE_STATUS_TXFULL	0x08
+#define ULITE_STATUS_IE		0x10
+#define ULITE_STATUS_OVERRUN	0x20
+#define ULITE_STATUS_FRAME	0x40
+#define ULITE_STATUS_PARITY	0x80
+
+#define ULITE_CONTROL_RST_TX	0x01
+#define ULITE_CONTROL_RST_RX	0x02
+#define ULITE_CONTROL_IE	0x10
+#define UART_AUTOSUSPEND_TIMEOUT	3000	/* ms */
+
+/* Static pointer to console port */
+#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
+static struct uart_port *console_port;
+#endif
+
+/**
+ * struct uartlite_data: Driver private data
+ * reg_ops: Functions to read/write registers
+ * clk: Our parent clock, if present
+ * baud: The baud rate configured when this device was synthesized
+ * cflags: The cflags for parity and data bits
+ */
+struct uartlite_data {
+	const struct uartlite_reg_ops *reg_ops;
+	struct clk *clk;
+	unsigned int baud;
+	tcflag_t cflags;
+};
+
+struct uartlite_reg_ops {
+	u32 (*in)(void __iomem *addr);
+	void (*out)(u32 val, void __iomem *addr);
+};
+
+static u32 uartlite_inbe32(void __iomem *addr)
+{
+	return ioread32be(addr);
+}
+
+static void uartlite_outbe32(u32 val, void __iomem *addr)
+{
+	iowrite32be(val, addr);
+}
+
+static const struct uartlite_reg_ops uartlite_be = {
+	.in = uartlite_inbe32,
+	.out = uartlite_outbe32,
+};
+
+static u32 uartlite_inle32(void __iomem *addr)
+{
+	return ioread32(addr);
+}
+
+static void uartlite_outle32(u32 val, void __iomem *addr)
+{
+	iowrite32(val, addr);
+}
+
+static const struct uartlite_reg_ops uartlite_le = {
+	.in = uartlite_inle32,
+	.out = uartlite_outle32,
+};
+
+static inline u32 uart_in32(u32 offset, struct uart_port *port)
+{
+	struct uartlite_data *pdata = port->private_data;
+
+	return pdata->reg_ops->in(port->membase + offset);
+}
+
+static inline void uart_out32(u32 val, u32 offset, struct uart_port *port)
+{
+	struct uartlite_data *pdata = port->private_data;
+
+	pdata->reg_ops->out(val, port->membase + offset);
+}
+
+static struct uart_port ulite_ports[ULITE_NR_UARTS];
+
+static struct uart_driver ulite_uart_driver;
+
+/* ---------------------------------------------------------------------
+ * Core UART driver operations
+ */
+
+static int ulite_receive(struct uart_port *port, int stat)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned char ch = 0;
+	char flag = TTY_NORMAL;
+
+	if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
+		     | ULITE_STATUS_FRAME)) == 0)
+		return 0;
+
+	/* stats */
+	if (stat & ULITE_STATUS_RXVALID) {
+		port->icount.rx++;
+		ch = uart_in32(ULITE_RX, port);
+
+		if (stat & ULITE_STATUS_PARITY)
+			port->icount.parity++;
+	}
+
+	if (stat & ULITE_STATUS_OVERRUN)
+		port->icount.overrun++;
+
+	if (stat & ULITE_STATUS_FRAME)
+		port->icount.frame++;
+
+
+	/* drop byte with parity error if IGNPAR specificed */
+	if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
+		stat &= ~ULITE_STATUS_RXVALID;
+
+	stat &= port->read_status_mask;
+
+	if (stat & ULITE_STATUS_PARITY)
+		flag = TTY_PARITY;
+
+
+	stat &= ~port->ignore_status_mask;
+
+	if (stat & ULITE_STATUS_RXVALID)
+		tty_insert_flip_char(tport, ch, flag);
+
+	if (stat & ULITE_STATUS_FRAME)
+		tty_insert_flip_char(tport, 0, TTY_FRAME);
+
+	if (stat & ULITE_STATUS_OVERRUN)
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+
+	return 1;
+}
+
+static int ulite_transmit(struct uart_port *port, int stat)
+{
+	struct circ_buf *xmit  = &port->state->xmit;
+
+	if (stat & ULITE_STATUS_TXFULL)
+		return 0;
+
+	if (port->x_char) {
+		uart_out32(port->x_char, ULITE_TX, port);
+		port->x_char = 0;
+		port->icount.tx++;
+		return 1;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return 0;
+
+	uart_out32(xmit->buf[xmit->tail], ULITE_TX, port);
+	uart_xmit_advance(port, 1);
+
+	/* wake up */
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	return 1;
+}
+
+static irqreturn_t ulite_isr(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	int stat, busy, n = 0;
+	unsigned long flags;
+
+	do {
+		spin_lock_irqsave(&port->lock, flags);
+		stat = uart_in32(ULITE_STATUS, port);
+		busy  = ulite_receive(port, stat);
+		busy |= ulite_transmit(port, stat);
+		spin_unlock_irqrestore(&port->lock, flags);
+		n++;
+	} while (busy);
+
+	/* work done? */
+	if (n > 1) {
+		tty_flip_buffer_push(&port->state->port);
+		return IRQ_HANDLED;
+	} else {
+		return IRQ_NONE;
+	}
+}
+
+static unsigned int ulite_tx_empty(struct uart_port *port)
+{
+	unsigned long flags;
+	unsigned int ret;
+
+	spin_lock_irqsave(&port->lock, flags);
+	ret = uart_in32(ULITE_STATUS, port);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int ulite_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* N/A */
+}
+
+static void ulite_stop_tx(struct uart_port *port)
+{
+	/* N/A */
+}
+
+static void ulite_start_tx(struct uart_port *port)
+{
+	ulite_transmit(port, uart_in32(ULITE_STATUS, port));
+}
+
+static void ulite_stop_rx(struct uart_port *port)
+{
+	/* don't forward any more data (like !CREAD) */
+	port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
+		| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
+}
+
+static void ulite_break_ctl(struct uart_port *port, int ctl)
+{
+	/* N/A */
+}
+
+static int ulite_startup(struct uart_port *port)
+{
+	struct uartlite_data *pdata = port->private_data;
+	int ret;
+
+	ret = clk_enable(pdata->clk);
+	if (ret) {
+		dev_err(port->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	ret = request_irq(port->irq, ulite_isr, IRQF_SHARED | IRQF_TRIGGER_RISING,
+			  "uartlite", port);
+	if (ret)
+		return ret;
+
+	uart_out32(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
+		ULITE_CONTROL, port);
+	uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
+
+	return 0;
+}
+
+static void ulite_shutdown(struct uart_port *port)
+{
+	struct uartlite_data *pdata = port->private_data;
+
+	uart_out32(0, ULITE_CONTROL, port);
+	uart_in32(ULITE_CONTROL, port); /* dummy */
+	free_irq(port->irq, port);
+	clk_disable(pdata->clk);
+}
+
+static void ulite_set_termios(struct uart_port *port,
+			      struct ktermios *termios,
+			      const struct ktermios *old)
+{
+	unsigned long flags;
+	struct uartlite_data *pdata = port->private_data;
+
+	/* Set termios to what the hardware supports */
+	termios->c_iflag &= ~BRKINT;
+	termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CSIZE);
+	termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE);
+	tty_termios_encode_baud_rate(termios, pdata->baud, pdata->baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
+		| ULITE_STATUS_TXFULL;
+
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |=
+			ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
+
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= ULITE_STATUS_PARITY
+			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
+
+	/* ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |=
+			ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
+			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
+
+	/* update timeout */
+	uart_update_timeout(port, termios->c_cflag, pdata->baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *ulite_type(struct uart_port *port)
+{
+	return port->type == PORT_UARTLITE ? "uartlite" : NULL;
+}
+
+static void ulite_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, ULITE_REGION);
+	iounmap(port->membase);
+	port->membase = NULL;
+}
+
+static int ulite_request_port(struct uart_port *port)
+{
+	struct uartlite_data *pdata = port->private_data;
+	int ret;
+
+	pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
+		 port, (unsigned long long) port->mapbase);
+
+	if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
+		dev_err(port->dev, "Memory region busy\n");
+		return -EBUSY;
+	}
+
+	port->membase = ioremap(port->mapbase, ULITE_REGION);
+	if (!port->membase) {
+		dev_err(port->dev, "Unable to map registers\n");
+		release_mem_region(port->mapbase, ULITE_REGION);
+		return -EBUSY;
+	}
+
+	pdata->reg_ops = &uartlite_be;
+	ret = uart_in32(ULITE_CONTROL, port);
+	uart_out32(ULITE_CONTROL_RST_TX, ULITE_CONTROL, port);
+	ret = uart_in32(ULITE_STATUS, port);
+	/* Endianess detection */
+	if ((ret & ULITE_STATUS_TXEMPTY) != ULITE_STATUS_TXEMPTY)
+		pdata->reg_ops = &uartlite_le;
+
+	return 0;
+}
+
+static void ulite_config_port(struct uart_port *port, int flags)
+{
+	if (!ulite_request_port(port))
+		port->type = PORT_UARTLITE;
+}
+
+static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* we don't want the core code to modify any port params */
+	return -EINVAL;
+}
+
+static void ulite_pm(struct uart_port *port, unsigned int state,
+		     unsigned int oldstate)
+{
+	int ret;
+
+	if (!state) {
+		ret = pm_runtime_get_sync(port->dev);
+		if (ret < 0)
+			dev_err(port->dev, "Failed to enable clocks\n");
+	} else {
+		pm_runtime_mark_last_busy(port->dev);
+		pm_runtime_put_autosuspend(port->dev);
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int ulite_get_poll_char(struct uart_port *port)
+{
+	if (!(uart_in32(ULITE_STATUS, port) & ULITE_STATUS_RXVALID))
+		return NO_POLL_CHAR;
+
+	return uart_in32(ULITE_RX, port);
+}
+
+static void ulite_put_poll_char(struct uart_port *port, unsigned char ch)
+{
+	while (uart_in32(ULITE_STATUS, port) & ULITE_STATUS_TXFULL)
+		cpu_relax();
+
+	/* write char to device */
+	uart_out32(ch, ULITE_TX, port);
+}
+#endif
+
+static const struct uart_ops ulite_ops = {
+	.tx_empty	= ulite_tx_empty,
+	.set_mctrl	= ulite_set_mctrl,
+	.get_mctrl	= ulite_get_mctrl,
+	.stop_tx	= ulite_stop_tx,
+	.start_tx	= ulite_start_tx,
+	.stop_rx	= ulite_stop_rx,
+	.break_ctl	= ulite_break_ctl,
+	.startup	= ulite_startup,
+	.shutdown	= ulite_shutdown,
+	.set_termios	= ulite_set_termios,
+	.type		= ulite_type,
+	.release_port	= ulite_release_port,
+	.request_port	= ulite_request_port,
+	.config_port	= ulite_config_port,
+	.verify_port	= ulite_verify_port,
+	.pm		= ulite_pm,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= ulite_get_poll_char,
+	.poll_put_char	= ulite_put_poll_char,
+#endif
+};
+
+/* ---------------------------------------------------------------------
+ * Console driver operations
+ */
+
+#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
+static void ulite_console_wait_tx(struct uart_port *port)
+{
+	u8 val;
+
+	/*
+	 * Spin waiting for TX fifo to have space available.
+	 * When using the Microblaze Debug Module this can take up to 1s
+	 */
+	if (read_poll_timeout_atomic(uart_in32, val, !(val & ULITE_STATUS_TXFULL),
+				     0, 1000000, false, ULITE_STATUS, port))
+		dev_warn(port->dev,
+			 "timeout waiting for TX buffer empty\n");
+}
+
+static void ulite_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	ulite_console_wait_tx(port);
+	uart_out32(ch, ULITE_TX, port);
+}
+
+static void ulite_console_write(struct console *co, const char *s,
+				unsigned int count)
+{
+	struct uart_port *port = console_port;
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	if (oops_in_progress) {
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	} else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/* save and disable interrupt */
+	ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
+	uart_out32(0, ULITE_CONTROL, port);
+
+	uart_console_write(port, s, count, ulite_console_putchar);
+
+	ulite_console_wait_tx(port);
+
+	/* restore interrupt state */
+	if (ier)
+		uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int ulite_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port = NULL;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= 0 && co->index < ULITE_NR_UARTS)
+		port = ulite_ports + co->index;
+
+	/* Has the device been initialized yet? */
+	if (!port || !port->mapbase) {
+		pr_debug("console on ttyUL%i not present\n", co->index);
+		return -ENODEV;
+	}
+
+	console_port = port;
+
+	/* not initialized yet? */
+	if (!port->membase) {
+		if (ulite_request_port(port))
+			return -ENODEV;
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console ulite_console = {
+	.name	= ULITE_NAME,
+	.write	= ulite_console_write,
+	.device	= uart_console_device,
+	.setup	= ulite_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
+	.data	= &ulite_uart_driver,
+};
+
+static void early_uartlite_putc(struct uart_port *port, unsigned char c)
+{
+	/*
+	 * Limit how many times we'll spin waiting for TX FIFO status.
+	 * This will prevent lockups if the base address is incorrectly
+	 * set, or any other issue on the UARTLITE.
+	 * This limit is pretty arbitrary, unless we are at about 10 baud
+	 * we'll never timeout on a working UART.
+	 */
+	unsigned retries = 1000000;
+
+	while (--retries &&
+	       (readl(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL))
+		;
+
+	/* Only attempt the iowrite if we didn't timeout */
+	if (retries)
+		writel(c & 0xff, port->membase + ULITE_TX);
+}
+
+static void early_uartlite_write(struct console *console,
+				 const char *s, unsigned n)
+{
+	struct earlycon_device *device = console->data;
+	uart_console_write(&device->port, s, n, early_uartlite_putc);
+}
+
+static int __init early_uartlite_setup(struct earlycon_device *device,
+				       const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = early_uartlite_write;
+	return 0;
+}
+EARLYCON_DECLARE(uartlite, early_uartlite_setup);
+OF_EARLYCON_DECLARE(uartlite_b, "xlnx,opb-uartlite-1.00.b", early_uartlite_setup);
+OF_EARLYCON_DECLARE(uartlite_a, "xlnx,xps-uartlite-1.00.a", early_uartlite_setup);
+
+#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
+
+static struct uart_driver ulite_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "uartlite",
+	.dev_name	= ULITE_NAME,
+	.major		= ULITE_MAJOR,
+	.minor		= ULITE_MINOR,
+	.nr		= ULITE_NR_UARTS,
+#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
+	.cons		= &ulite_console,
+#endif
+};
+
+/* ---------------------------------------------------------------------
+ * Port assignment functions (mapping devices to uart_port structures)
+ */
+
+/** ulite_assign: register a uartlite device with the driver
+ *
+ * @dev: pointer to device structure
+ * @id: requested id number.  Pass -1 for automatic port assignment
+ * @base: base address of uartlite registers
+ * @irq: irq number for uartlite
+ * @pdata: private data for uartlite
+ *
+ * Returns: 0 on success, <0 otherwise
+ */
+static int ulite_assign(struct device *dev, int id, phys_addr_t base, int irq,
+			struct uartlite_data *pdata)
+{
+	struct uart_port *port;
+	int rc;
+
+	/* if id = -1; then scan for a free id and use that */
+	if (id < 0) {
+		for (id = 0; id < ULITE_NR_UARTS; id++)
+			if (ulite_ports[id].mapbase == 0)
+				break;
+	}
+	if (id < 0 || id >= ULITE_NR_UARTS) {
+		dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
+		return -EINVAL;
+	}
+
+	if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
+		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
+			ULITE_NAME, id);
+		return -EBUSY;
+	}
+
+	port = &ulite_ports[id];
+
+	spin_lock_init(&port->lock);
+	port->fifosize = 16;
+	port->regshift = 2;
+	port->iotype = UPIO_MEM;
+	port->iobase = 1; /* mark port in use */
+	port->mapbase = base;
+	port->membase = NULL;
+	port->ops = &ulite_ops;
+	port->irq = irq;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = dev;
+	port->type = PORT_UNKNOWN;
+	port->line = id;
+	port->private_data = pdata;
+
+	dev_set_drvdata(dev, port);
+
+	/* Register the port */
+	rc = uart_add_one_port(&ulite_uart_driver, port);
+	if (rc) {
+		dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
+		port->mapbase = 0;
+		dev_set_drvdata(dev, NULL);
+		return rc;
+	}
+
+	return 0;
+}
+
+/** ulite_release: register a uartlite device with the driver
+ *
+ * @dev: pointer to device structure
+ */
+static void ulite_release(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	if (port) {
+		uart_remove_one_port(&ulite_uart_driver, port);
+		dev_set_drvdata(dev, NULL);
+		port->mapbase = 0;
+	}
+}
+
+/**
+ * ulite_suspend - Stop the device.
+ *
+ * @dev: handle to the device structure.
+ * Return: 0 always.
+ */
+static int __maybe_unused ulite_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	if (port)
+		uart_suspend_port(&ulite_uart_driver, port);
+
+	return 0;
+}
+
+/**
+ * ulite_resume - Resume the device.
+ *
+ * @dev: handle to the device structure.
+ * Return: 0 on success, errno otherwise.
+ */
+static int __maybe_unused ulite_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	if (port)
+		uart_resume_port(&ulite_uart_driver, port);
+
+	return 0;
+}
+
+static int __maybe_unused ulite_runtime_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct uartlite_data *pdata = port->private_data;
+
+	clk_disable(pdata->clk);
+	return 0;
+};
+
+static int __maybe_unused ulite_runtime_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct uartlite_data *pdata = port->private_data;
+	int ret;
+
+	ret = clk_enable(pdata->clk);
+	if (ret) {
+		dev_err(dev, "Cannot enable clock.\n");
+		return ret;
+	}
+	return 0;
+}
+
+/* ---------------------------------------------------------------------
+ * Platform bus binding
+ */
+
+static const struct dev_pm_ops ulite_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume)
+	SET_RUNTIME_PM_OPS(ulite_runtime_suspend,
+			   ulite_runtime_resume, NULL)
+};
+
+#if defined(CONFIG_OF)
+/* Match table for of_platform binding */
+static const struct of_device_id ulite_of_match[] = {
+	{ .compatible = "xlnx,opb-uartlite-1.00.b", },
+	{ .compatible = "xlnx,xps-uartlite-1.00.a", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ulite_of_match);
+#endif /* CONFIG_OF */
+
+static int ulite_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct uartlite_data *pdata;
+	int irq, ret;
+	int id = pdev->id;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data),
+			     GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	if (IS_ENABLED(CONFIG_OF)) {
+		const char *prop;
+		struct device_node *np = pdev->dev.of_node;
+		u32 val = 0;
+
+		prop = "port-number";
+		ret = of_property_read_u32(np, prop, &id);
+		if (ret && ret != -EINVAL)
+of_err:
+			return dev_err_probe(&pdev->dev, ret,
+					     "could not read %s\n", prop);
+
+		prop = "current-speed";
+		ret = of_property_read_u32(np, prop, &pdata->baud);
+		if (ret)
+			goto of_err;
+
+		prop = "xlnx,use-parity";
+		ret = of_property_read_u32(np, prop, &val);
+		if (ret && ret != -EINVAL)
+			goto of_err;
+
+		if (val) {
+			prop = "xlnx,odd-parity";
+			ret = of_property_read_u32(np, prop, &val);
+			if (ret)
+				goto of_err;
+
+			if (val)
+				pdata->cflags |= PARODD;
+			pdata->cflags |= PARENB;
+		}
+
+		val = 8;
+		prop = "xlnx,data-bits";
+		ret = of_property_read_u32(np, prop, &val);
+		if (ret && ret != -EINVAL)
+			goto of_err;
+
+		switch (val) {
+		case 5:
+			pdata->cflags |= CS5;
+			break;
+		case 6:
+			pdata->cflags |= CS6;
+			break;
+		case 7:
+			pdata->cflags |= CS7;
+			break;
+		case 8:
+			pdata->cflags |= CS8;
+			break;
+		default:
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "bad data bits %d\n", val);
+		}
+	} else {
+		pdata->baud = 9600;
+		pdata->cflags = CS8;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	pdata->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
+	if (IS_ERR(pdata->clk)) {
+		if (PTR_ERR(pdata->clk) != -ENOENT)
+			return PTR_ERR(pdata->clk);
+
+		/*
+		 * Clock framework support is optional, continue on
+		 * anyways if we don't find a matching clock.
+		 */
+		pdata->clk = NULL;
+	}
+
+	ret = clk_prepare_enable(pdata->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to prepare clock\n");
+		return ret;
+	}
+
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	if (!ulite_uart_driver.state) {
+		dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n");
+		ret = uart_register_driver(&ulite_uart_driver);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Failed to register driver\n");
+			clk_disable_unprepare(pdata->clk);
+			return ret;
+		}
+	}
+
+	ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata);
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
+	return ret;
+}
+
+static int ulite_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = dev_get_drvdata(&pdev->dev);
+	struct uartlite_data *pdata = port->private_data;
+
+	clk_disable_unprepare(pdata->clk);
+	ulite_release(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:uartlite");
+
+static struct platform_driver ulite_platform_driver = {
+	.probe = ulite_probe,
+	.remove = ulite_remove,
+	.driver = {
+		.name  = "uartlite",
+		.of_match_table = of_match_ptr(ulite_of_match),
+		.pm = &ulite_pm_ops,
+	},
+};
+
+/* ---------------------------------------------------------------------
+ * Module setup/teardown
+ */
+
+static int __init ulite_init(void)
+{
+
+	pr_debug("uartlite: calling platform_driver_register()\n");
+	return platform_driver_register(&ulite_platform_driver);
+}
+
+static void __exit ulite_exit(void)
+{
+	platform_driver_unregister(&ulite_platform_driver);
+	if (ulite_uart_driver.state)
+		uart_unregister_driver(&ulite_uart_driver);
+}
+
+module_init(ulite_init);
+module_exit(ulite_exit);
+
+MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
+MODULE_DESCRIPTION("Xilinx uartlite serial driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
new file mode 100644
index 000000000..b06661b80
--- /dev/null
+++ b/drivers/tty/serial/ucc_uart.c
@@ -0,0 +1,1539 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Freescale QUICC Engine UART device driver
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * Copyright 2007 Freescale Semiconductor, Inc.
+ *
+ * This driver adds support for UART devices via Freescale's QUICC Engine
+ * found on some Freescale SOCs.
+ *
+ * If Soft-UART support is needed but not already present, then this driver
+ * will request and upload the "Soft-UART" microcode upon probe.  The
+ * filename of the microcode should be fsl_qe_ucode_uart_X_YZ.bin, where "X"
+ * is the name of the SOC (e.g. 8323), and YZ is the revision of the SOC,
+ * (e.g. "11" for 1.1).
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/dma-mapping.h>
+
+#include <soc/fsl/qe/ucc_slow.h>
+
+#include <linux/firmware.h>
+#include <soc/fsl/cpm.h>
+
+#ifdef CONFIG_PPC32
+#include <asm/reg.h> /* mfspr, SPRN_SVR */
+#endif
+
+/*
+ * The GUMR flag for Soft UART.  This would normally be defined in qe.h,
+ * but Soft-UART is a hack and we want to keep everything related to it in
+ * this file.
+ */
+#define UCC_SLOW_GUMR_H_SUART   	0x00004000      /* Soft-UART */
+
+/*
+ * soft_uart is 1 if we need to use Soft-UART mode
+ */
+static int soft_uart;
+/*
+ * firmware_loaded is 1 if the firmware has been loaded, 0 otherwise.
+ */
+static int firmware_loaded;
+
+/* Enable this macro to configure all serial ports in internal loopback
+   mode */
+/* #define LOOPBACK */
+
+/* The major and minor device numbers are defined in
+ * Documentation/admin-guide/devices.txt.  For the QE
+ * UART, we have major number 204 and minor numbers 46 - 49, which are the
+ * same as for the CPM2.  This decision was made because no Freescale part
+ * has both a CPM and a QE.
+ */
+#define SERIAL_QE_MAJOR 204
+#define SERIAL_QE_MINOR 46
+
+/* Since we only have minor numbers 46 - 49, there is a hard limit of 4 ports */
+#define UCC_MAX_UART    4
+
+/* The number of buffer descriptors for receiving characters. */
+#define RX_NUM_FIFO     4
+
+/* The number of buffer descriptors for transmitting characters. */
+#define TX_NUM_FIFO     4
+
+/* The maximum size of the character buffer for a single RX BD. */
+#define RX_BUF_SIZE     32
+
+/* The maximum size of the character buffer for a single TX BD. */
+#define TX_BUF_SIZE     32
+
+/*
+ * The number of jiffies to wait after receiving a close command before the
+ * device is actually closed.  This allows the last few characters to be
+ * sent over the wire.
+ */
+#define UCC_WAIT_CLOSING 100
+
+struct ucc_uart_pram {
+	struct ucc_slow_pram common;
+	u8 res1[8];     	/* reserved */
+	__be16 maxidl;  	/* Maximum idle chars */
+	__be16 idlc;    	/* temp idle counter */
+	__be16 brkcr;   	/* Break count register */
+	__be16 parec;   	/* receive parity error counter */
+	__be16 frmec;   	/* receive framing error counter */
+	__be16 nosec;   	/* receive noise counter */
+	__be16 brkec;   	/* receive break condition counter */
+	__be16 brkln;   	/* last received break length */
+	__be16 uaddr[2];	/* UART address character 1 & 2 */
+	__be16 rtemp;   	/* Temp storage */
+	__be16 toseq;   	/* Transmit out of sequence char */
+	__be16 cchars[8];       /* control characters 1-8 */
+	__be16 rccm;    	/* receive control character mask */
+	__be16 rccr;    	/* receive control character register */
+	__be16 rlbc;    	/* receive last break character */
+	__be16 res2;    	/* reserved */
+	__be32 res3;    	/* reserved, should be cleared */
+	u8 res4;		/* reserved, should be cleared */
+	u8 res5[3];     	/* reserved, should be cleared */
+	__be32 res6;    	/* reserved, should be cleared */
+	__be32 res7;    	/* reserved, should be cleared */
+	__be32 res8;    	/* reserved, should be cleared */
+	__be32 res9;    	/* reserved, should be cleared */
+	__be32 res10;   	/* reserved, should be cleared */
+	__be32 res11;   	/* reserved, should be cleared */
+	__be32 res12;   	/* reserved, should be cleared */
+	__be32 res13;   	/* reserved, should be cleared */
+/* The rest is for Soft-UART only */
+	__be16 supsmr;  	/* 0x90, Shadow UPSMR */
+	__be16 res92;   	/* 0x92, reserved, initialize to 0 */
+	__be32 rx_state;	/* 0x94, RX state, initialize to 0 */
+	__be32 rx_cnt;  	/* 0x98, RX count, initialize to 0 */
+	u8 rx_length;   	/* 0x9C, Char length, set to 1+CL+PEN+1+SL */
+	u8 rx_bitmark;  	/* 0x9D, reserved, initialize to 0 */
+	u8 rx_temp_dlst_qe;     /* 0x9E, reserved, initialize to 0 */
+	u8 res14[0xBC - 0x9F];  /* reserved */
+	__be32 dump_ptr;	/* 0xBC, Dump pointer */
+	__be32 rx_frame_rem;    /* 0xC0, reserved, initialize to 0 */
+	u8 rx_frame_rem_size;   /* 0xC4, reserved, initialize to 0 */
+	u8 tx_mode;     	/* 0xC5, mode, 0=AHDLC, 1=UART */
+	__be16 tx_state;	/* 0xC6, TX state */
+	u8 res15[0xD0 - 0xC8];  /* reserved */
+	__be32 resD0;   	/* 0xD0, reserved, initialize to 0 */
+	u8 resD4;       	/* 0xD4, reserved, initialize to 0 */
+	__be16 resD5;   	/* 0xD5, reserved, initialize to 0 */
+} __attribute__ ((packed));
+
+/* SUPSMR definitions, for Soft-UART only */
+#define UCC_UART_SUPSMR_SL      	0x8000
+#define UCC_UART_SUPSMR_RPM_MASK	0x6000
+#define UCC_UART_SUPSMR_RPM_ODD 	0x0000
+#define UCC_UART_SUPSMR_RPM_LOW 	0x2000
+#define UCC_UART_SUPSMR_RPM_EVEN	0x4000
+#define UCC_UART_SUPSMR_RPM_HIGH	0x6000
+#define UCC_UART_SUPSMR_PEN     	0x1000
+#define UCC_UART_SUPSMR_TPM_MASK	0x0C00
+#define UCC_UART_SUPSMR_TPM_ODD 	0x0000
+#define UCC_UART_SUPSMR_TPM_LOW 	0x0400
+#define UCC_UART_SUPSMR_TPM_EVEN	0x0800
+#define UCC_UART_SUPSMR_TPM_HIGH	0x0C00
+#define UCC_UART_SUPSMR_FRZ     	0x0100
+#define UCC_UART_SUPSMR_UM_MASK 	0x00c0
+#define UCC_UART_SUPSMR_UM_NORMAL       0x0000
+#define UCC_UART_SUPSMR_UM_MAN_MULTI    0x0040
+#define UCC_UART_SUPSMR_UM_AUTO_MULTI   0x00c0
+#define UCC_UART_SUPSMR_CL_MASK 	0x0030
+#define UCC_UART_SUPSMR_CL_8    	0x0030
+#define UCC_UART_SUPSMR_CL_7    	0x0020
+#define UCC_UART_SUPSMR_CL_6    	0x0010
+#define UCC_UART_SUPSMR_CL_5    	0x0000
+
+#define UCC_UART_TX_STATE_AHDLC 	0x00
+#define UCC_UART_TX_STATE_UART  	0x01
+#define UCC_UART_TX_STATE_X1    	0x00
+#define UCC_UART_TX_STATE_X16   	0x80
+
+#define UCC_UART_PRAM_ALIGNMENT 0x100
+
+#define UCC_UART_SIZE_OF_BD     UCC_SLOW_SIZE_OF_BD
+#define NUM_CONTROL_CHARS       8
+
+/* Private per-port data structure */
+struct uart_qe_port {
+	struct uart_port port;
+	struct ucc_slow __iomem *uccp;
+	struct ucc_uart_pram __iomem *uccup;
+	struct ucc_slow_info us_info;
+	struct ucc_slow_private *us_private;
+	struct device_node *np;
+	unsigned int ucc_num;   /* First ucc is 0, not 1 */
+
+	u16 rx_nrfifos;
+	u16 rx_fifosize;
+	u16 tx_nrfifos;
+	u16 tx_fifosize;
+	int wait_closing;
+	u32 flags;
+	struct qe_bd *rx_bd_base;
+	struct qe_bd *rx_cur;
+	struct qe_bd *tx_bd_base;
+	struct qe_bd *tx_cur;
+	unsigned char *tx_buf;
+	unsigned char *rx_buf;
+	void *bd_virt;  	/* virtual address of the BD buffers */
+	dma_addr_t bd_dma_addr; /* bus address of the BD buffers */
+	unsigned int bd_size;   /* size of BD buffer space */
+};
+
+static struct uart_driver ucc_uart_driver = {
+	.owner  	= THIS_MODULE,
+	.driver_name    = "ucc_uart",
+	.dev_name       = "ttyQE",
+	.major  	= SERIAL_QE_MAJOR,
+	.minor  	= SERIAL_QE_MINOR,
+	.nr     	= UCC_MAX_UART,
+};
+
+/*
+ * Virtual to physical address translation.
+ *
+ * Given the virtual address for a character buffer, this function returns
+ * the physical (DMA) equivalent.
+ */
+static inline dma_addr_t cpu2qe_addr(void *addr, struct uart_qe_port *qe_port)
+{
+	if (likely((addr >= qe_port->bd_virt)) &&
+	    (addr < (qe_port->bd_virt + qe_port->bd_size)))
+		return qe_port->bd_dma_addr + (addr - qe_port->bd_virt);
+
+	/* something nasty happened */
+	printk(KERN_ERR "%s: addr=%p\n", __func__, addr);
+	BUG();
+	return 0;
+}
+
+/*
+ * Physical to virtual address translation.
+ *
+ * Given the physical (DMA) address for a character buffer, this function
+ * returns the virtual equivalent.
+ */
+static inline void *qe2cpu_addr(dma_addr_t addr, struct uart_qe_port *qe_port)
+{
+	/* sanity check */
+	if (likely((addr >= qe_port->bd_dma_addr) &&
+		   (addr < (qe_port->bd_dma_addr + qe_port->bd_size))))
+		return qe_port->bd_virt + (addr - qe_port->bd_dma_addr);
+
+	/* something nasty happened */
+	printk(KERN_ERR "%s: addr=%llx\n", __func__, (u64)addr);
+	BUG();
+	return NULL;
+}
+
+/*
+ * Return 1 if the QE is done transmitting all buffers for this port
+ *
+ * This function scans each BD in sequence.  If we find a BD that is not
+ * ready (READY=1), then we return 0 indicating that the QE is still sending
+ * data.  If we reach the last BD (WRAP=1), then we know we've scanned
+ * the entire list, and all BDs are done.
+ */
+static unsigned int qe_uart_tx_empty(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct qe_bd *bdp = qe_port->tx_bd_base;
+
+	while (1) {
+		if (ioread16be(&bdp->status) & BD_SC_READY)
+			/* This BD is not done, so return "not done" */
+			return 0;
+
+		if (ioread16be(&bdp->status) & BD_SC_WRAP)
+			/*
+			 * This BD is done and it's the last one, so return
+			 * "done"
+			 */
+			return 1;
+
+		bdp++;
+	}
+}
+
+/*
+ * Set the modem control lines
+ *
+ * Although the QE can control the modem control lines (e.g. CTS), we
+ * don't need that support. This function must exist, however, otherwise
+ * the kernel will panic.
+ */
+static void qe_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+/*
+ * Get the current modem control line status
+ *
+ * Although the QE can control the modem control lines (e.g. CTS), this
+ * driver currently doesn't support that, so we always return Carrier
+ * Detect, Data Set Ready, and Clear To Send.
+ */
+static unsigned int qe_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/*
+ * Disable the transmit interrupt.
+ *
+ * Although this function is called "stop_tx", it does not actually stop
+ * transmission of data.  Instead, it tells the QE to not generate an
+ * interrupt when the UCC is finished sending characters.
+ */
+static void qe_uart_stop_tx(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	qe_clrbits_be16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX);
+}
+
+/*
+ * Transmit as many characters to the HW as possible.
+ *
+ * This function will attempt to stuff of all the characters from the
+ * kernel's transmit buffer into TX BDs.
+ *
+ * A return value of non-zero indicates that it successfully stuffed all
+ * characters from the kernel buffer.
+ *
+ * A return value of zero indicates that there are still characters in the
+ * kernel's buffer that have not been transmitted, but there are no more BDs
+ * available.  This function should be called again after a BD has been made
+ * available.
+ */
+static int qe_uart_tx_pump(struct uart_qe_port *qe_port)
+{
+	struct qe_bd *bdp;
+	unsigned char *p;
+	unsigned int count;
+	struct uart_port *port = &qe_port->port;
+	struct circ_buf *xmit = &port->state->xmit;
+
+	/* Handle xon/xoff */
+	if (port->x_char) {
+		/* Pick next descriptor and fill from buffer */
+		bdp = qe_port->tx_cur;
+
+		p = qe2cpu_addr(be32_to_cpu(bdp->buf), qe_port);
+
+		*p++ = port->x_char;
+		iowrite16be(1, &bdp->length);
+		qe_setbits_be16(&bdp->status, BD_SC_READY);
+		/* Get next BD. */
+		if (ioread16be(&bdp->status) & BD_SC_WRAP)
+			bdp = qe_port->tx_bd_base;
+		else
+			bdp++;
+		qe_port->tx_cur = bdp;
+
+		port->icount.tx++;
+		port->x_char = 0;
+		return 1;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		qe_uart_stop_tx(port);
+		return 0;
+	}
+
+	/* Pick next descriptor and fill from buffer */
+	bdp = qe_port->tx_cur;
+
+	while (!(ioread16be(&bdp->status) & BD_SC_READY) && !uart_circ_empty(xmit)) {
+		count = 0;
+		p = qe2cpu_addr(be32_to_cpu(bdp->buf), qe_port);
+		while (count < qe_port->tx_fifosize) {
+			*p++ = xmit->buf[xmit->tail];
+			uart_xmit_advance(port, 1);
+			count++;
+			if (uart_circ_empty(xmit))
+				break;
+		}
+
+		iowrite16be(count, &bdp->length);
+		qe_setbits_be16(&bdp->status, BD_SC_READY);
+
+		/* Get next BD. */
+		if (ioread16be(&bdp->status) & BD_SC_WRAP)
+			bdp = qe_port->tx_bd_base;
+		else
+			bdp++;
+	}
+	qe_port->tx_cur = bdp;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit)) {
+		/* The kernel buffer is empty, so turn off TX interrupts.  We
+		   don't need to be told when the QE is finished transmitting
+		   the data. */
+		qe_uart_stop_tx(port);
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * Start transmitting data
+ *
+ * This function will start transmitting any available data, if the port
+ * isn't already transmitting data.
+ */
+static void qe_uart_start_tx(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	/* If we currently are transmitting, then just return */
+	if (ioread16be(&qe_port->uccp->uccm) & UCC_UART_UCCE_TX)
+		return;
+
+	/* Otherwise, pump the port and start transmission */
+	if (qe_uart_tx_pump(qe_port))
+		qe_setbits_be16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX);
+}
+
+/*
+ * Stop transmitting data
+ */
+static void qe_uart_stop_rx(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	qe_clrbits_be16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX);
+}
+
+/* Start or stop sending  break signal
+ *
+ * This function controls the sending of a break signal.  If break_state=1,
+ * then we start sending a break signal.  If break_state=0, then we stop
+ * sending the break signal.
+ */
+static void qe_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	if (break_state)
+		ucc_slow_stop_tx(qe_port->us_private);
+	else
+		ucc_slow_restart_tx(qe_port->us_private);
+}
+
+/* ISR helper function for receiving character.
+ *
+ * This function is called by the ISR to handling receiving characters
+ */
+static void qe_uart_int_rx(struct uart_qe_port *qe_port)
+{
+	int i;
+	unsigned char ch, *cp;
+	struct uart_port *port = &qe_port->port;
+	struct tty_port *tport = &port->state->port;
+	struct qe_bd *bdp;
+	u16 status;
+	unsigned int flg;
+
+	/* Just loop through the closed BDs and copy the characters into
+	 * the buffer.
+	 */
+	bdp = qe_port->rx_cur;
+	while (1) {
+		status = ioread16be(&bdp->status);
+
+		/* If this one is empty, then we assume we've read them all */
+		if (status & BD_SC_EMPTY)
+			break;
+
+		/* get number of characters, and check space in RX buffer */
+		i = ioread16be(&bdp->length);
+
+		/* If we don't have enough room in RX buffer for the entire BD,
+		 * then we try later, which will be the next RX interrupt.
+		 */
+		if (tty_buffer_request_room(tport, i) < i) {
+			dev_dbg(port->dev, "ucc-uart: no room in RX buffer\n");
+			return;
+		}
+
+		/* get pointer */
+		cp = qe2cpu_addr(be32_to_cpu(bdp->buf), qe_port);
+
+		/* loop through the buffer */
+		while (i-- > 0) {
+			ch = *cp++;
+			port->icount.rx++;
+			flg = TTY_NORMAL;
+
+			if (!i && status &
+			    (BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV))
+				goto handle_error;
+			if (uart_handle_sysrq_char(port, ch))
+				continue;
+
+error_return:
+			tty_insert_flip_char(tport, ch, flg);
+
+		}
+
+		/* This BD is ready to be used again. Clear status. get next */
+		qe_clrsetbits_be16(&bdp->status,
+				   BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV | BD_SC_ID,
+				   BD_SC_EMPTY);
+		if (ioread16be(&bdp->status) & BD_SC_WRAP)
+			bdp = qe_port->rx_bd_base;
+		else
+			bdp++;
+
+	}
+
+	/* Write back buffer pointer */
+	qe_port->rx_cur = bdp;
+
+	/* Activate BH processing */
+	tty_flip_buffer_push(tport);
+
+	return;
+
+	/* Error processing */
+
+handle_error:
+	/* Statistics */
+	if (status & BD_SC_BR)
+		port->icount.brk++;
+	if (status & BD_SC_PR)
+		port->icount.parity++;
+	if (status & BD_SC_FR)
+		port->icount.frame++;
+	if (status & BD_SC_OV)
+		port->icount.overrun++;
+
+	/* Mask out ignored conditions */
+	status &= port->read_status_mask;
+
+	/* Handle the remaining ones */
+	if (status & BD_SC_BR)
+		flg = TTY_BREAK;
+	else if (status & BD_SC_PR)
+		flg = TTY_PARITY;
+	else if (status & BD_SC_FR)
+		flg = TTY_FRAME;
+
+	/* Overrun does not affect the current character ! */
+	if (status & BD_SC_OV)
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+	port->sysrq = 0;
+	goto error_return;
+}
+
+/* Interrupt handler
+ *
+ * This interrupt handler is called after a BD is processed.
+ */
+static irqreturn_t qe_uart_int(int irq, void *data)
+{
+	struct uart_qe_port *qe_port = (struct uart_qe_port *) data;
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	u16 events;
+
+	/* Clear the interrupts */
+	events = ioread16be(&uccp->ucce);
+	iowrite16be(events, &uccp->ucce);
+
+	if (events & UCC_UART_UCCE_BRKE)
+		uart_handle_break(&qe_port->port);
+
+	if (events & UCC_UART_UCCE_RX)
+		qe_uart_int_rx(qe_port);
+
+	if (events & UCC_UART_UCCE_TX)
+		qe_uart_tx_pump(qe_port);
+
+	return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+/* Initialize buffer descriptors
+ *
+ * This function initializes all of the RX and TX buffer descriptors.
+ */
+static void qe_uart_initbd(struct uart_qe_port *qe_port)
+{
+	int i;
+	void *bd_virt;
+	struct qe_bd *bdp;
+
+	/* Set the physical address of the host memory buffers in the buffer
+	 * descriptors, and the virtual address for us to work with.
+	 */
+	bd_virt = qe_port->bd_virt;
+	bdp = qe_port->rx_bd_base;
+	qe_port->rx_cur = qe_port->rx_bd_base;
+	for (i = 0; i < (qe_port->rx_nrfifos - 1); i++) {
+		iowrite16be(BD_SC_EMPTY | BD_SC_INTRPT, &bdp->status);
+		iowrite32be(cpu2qe_addr(bd_virt, qe_port), &bdp->buf);
+		iowrite16be(0, &bdp->length);
+		bd_virt += qe_port->rx_fifosize;
+		bdp++;
+	}
+
+	/* */
+	iowrite16be(BD_SC_WRAP | BD_SC_EMPTY | BD_SC_INTRPT, &bdp->status);
+	iowrite32be(cpu2qe_addr(bd_virt, qe_port), &bdp->buf);
+	iowrite16be(0, &bdp->length);
+
+	/* Set the physical address of the host memory
+	 * buffers in the buffer descriptors, and the
+	 * virtual address for us to work with.
+	 */
+	bd_virt = qe_port->bd_virt +
+		L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize);
+	qe_port->tx_cur = qe_port->tx_bd_base;
+	bdp = qe_port->tx_bd_base;
+	for (i = 0; i < (qe_port->tx_nrfifos - 1); i++) {
+		iowrite16be(BD_SC_INTRPT, &bdp->status);
+		iowrite32be(cpu2qe_addr(bd_virt, qe_port), &bdp->buf);
+		iowrite16be(0, &bdp->length);
+		bd_virt += qe_port->tx_fifosize;
+		bdp++;
+	}
+
+	/* Loopback requires the preamble bit to be set on the first TX BD */
+#ifdef LOOPBACK
+	qe_setbits_be16(&qe_port->tx_cur->status, BD_SC_P);
+#endif
+
+	iowrite16be(BD_SC_WRAP | BD_SC_INTRPT, &bdp->status);
+	iowrite32be(cpu2qe_addr(bd_virt, qe_port), &bdp->buf);
+	iowrite16be(0, &bdp->length);
+}
+
+/*
+ * Initialize a UCC for UART.
+ *
+ * This function configures a given UCC to be used as a UART device. Basic
+ * UCC initialization is handled in qe_uart_request_port().  This function
+ * does all the UART-specific stuff.
+ */
+static void qe_uart_init_ucc(struct uart_qe_port *qe_port)
+{
+	u32 cecr_subblock;
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	struct ucc_uart_pram *uccup = qe_port->uccup;
+
+	unsigned int i;
+
+	/* First, disable TX and RX in the UCC */
+	ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX);
+
+	/* Program the UCC UART parameter RAM */
+	iowrite8(UCC_BMR_GBL | UCC_BMR_BO_BE, &uccup->common.rbmr);
+	iowrite8(UCC_BMR_GBL | UCC_BMR_BO_BE, &uccup->common.tbmr);
+	iowrite16be(qe_port->rx_fifosize, &uccup->common.mrblr);
+	iowrite16be(0x10, &uccup->maxidl);
+	iowrite16be(1, &uccup->brkcr);
+	iowrite16be(0, &uccup->parec);
+	iowrite16be(0, &uccup->frmec);
+	iowrite16be(0, &uccup->nosec);
+	iowrite16be(0, &uccup->brkec);
+	iowrite16be(0, &uccup->uaddr[0]);
+	iowrite16be(0, &uccup->uaddr[1]);
+	iowrite16be(0, &uccup->toseq);
+	for (i = 0; i < 8; i++)
+		iowrite16be(0xC000, &uccup->cchars[i]);
+	iowrite16be(0xc0ff, &uccup->rccm);
+
+	/* Configure the GUMR registers for UART */
+	if (soft_uart) {
+		/* Soft-UART requires a 1X multiplier for TX */
+		qe_clrsetbits_be32(&uccp->gumr_l,
+				   UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK | UCC_SLOW_GUMR_L_RDCR_MASK,
+				   UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_1 | UCC_SLOW_GUMR_L_RDCR_16);
+
+		qe_clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW,
+				   UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX);
+	} else {
+		qe_clrsetbits_be32(&uccp->gumr_l,
+				   UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK | UCC_SLOW_GUMR_L_RDCR_MASK,
+				   UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_16 | UCC_SLOW_GUMR_L_RDCR_16);
+
+		qe_clrsetbits_be32(&uccp->gumr_h,
+				   UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX,
+				   UCC_SLOW_GUMR_H_RFW);
+	}
+
+#ifdef LOOPBACK
+	qe_clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
+			   UCC_SLOW_GUMR_L_DIAG_LOOP);
+	qe_clrsetbits_be32(&uccp->gumr_h,
+			   UCC_SLOW_GUMR_H_CTSP | UCC_SLOW_GUMR_H_RSYN,
+			   UCC_SLOW_GUMR_H_CDS);
+#endif
+
+	/* Disable rx interrupts  and clear all pending events.  */
+	iowrite16be(0, &uccp->uccm);
+	iowrite16be(0xffff, &uccp->ucce);
+	iowrite16be(0x7e7e, &uccp->udsr);
+
+	/* Initialize UPSMR */
+	iowrite16be(0, &uccp->upsmr);
+
+	if (soft_uart) {
+		iowrite16be(0x30, &uccup->supsmr);
+		iowrite16be(0, &uccup->res92);
+		iowrite32be(0, &uccup->rx_state);
+		iowrite32be(0, &uccup->rx_cnt);
+		iowrite8(0, &uccup->rx_bitmark);
+		iowrite8(10, &uccup->rx_length);
+		iowrite32be(0x4000, &uccup->dump_ptr);
+		iowrite8(0, &uccup->rx_temp_dlst_qe);
+		iowrite32be(0, &uccup->rx_frame_rem);
+		iowrite8(0, &uccup->rx_frame_rem_size);
+		/* Soft-UART requires TX to be 1X */
+		iowrite8(UCC_UART_TX_STATE_UART | UCC_UART_TX_STATE_X1,
+			    &uccup->tx_mode);
+		iowrite16be(0, &uccup->tx_state);
+		iowrite8(0, &uccup->resD4);
+		iowrite16be(0, &uccup->resD5);
+
+		/* Set UART mode.
+		 * Enable receive and transmit.
+		 */
+
+		/* From the microcode errata:
+		 * 1.GUMR_L register, set mode=0010 (QMC).
+		 * 2.Set GUMR_H[17] bit. (UART/AHDLC mode).
+		 * 3.Set GUMR_H[19:20] (Transparent mode)
+		 * 4.Clear GUMR_H[26] (RFW)
+		 * ...
+		 * 6.Receiver must use 16x over sampling
+		 */
+		qe_clrsetbits_be32(&uccp->gumr_l,
+				   UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK | UCC_SLOW_GUMR_L_RDCR_MASK,
+				   UCC_SLOW_GUMR_L_MODE_QMC | UCC_SLOW_GUMR_L_TDCR_16 | UCC_SLOW_GUMR_L_RDCR_16);
+
+		qe_clrsetbits_be32(&uccp->gumr_h,
+				   UCC_SLOW_GUMR_H_RFW | UCC_SLOW_GUMR_H_RSYN,
+				   UCC_SLOW_GUMR_H_SUART | UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX | UCC_SLOW_GUMR_H_TFL);
+
+#ifdef LOOPBACK
+		qe_clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
+				   UCC_SLOW_GUMR_L_DIAG_LOOP);
+		qe_clrbits_be32(&uccp->gumr_h,
+				UCC_SLOW_GUMR_H_CTSP | UCC_SLOW_GUMR_H_CDS);
+#endif
+
+		cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num);
+		qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock,
+			QE_CR_PROTOCOL_UNSPECIFIED, 0);
+	} else {
+		cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num);
+		qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock,
+			QE_CR_PROTOCOL_UART, 0);
+	}
+}
+
+/*
+ * Initialize the port.
+ */
+static int qe_uart_startup(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	int ret;
+
+	/*
+	 * If we're using Soft-UART mode, then we need to make sure the
+	 * firmware has been uploaded first.
+	 */
+	if (soft_uart && !firmware_loaded) {
+		dev_err(port->dev, "Soft-UART firmware not uploaded\n");
+		return -ENODEV;
+	}
+
+	qe_uart_initbd(qe_port);
+	qe_uart_init_ucc(qe_port);
+
+	/* Install interrupt handler. */
+	ret = request_irq(port->irq, qe_uart_int, IRQF_SHARED, "ucc-uart",
+		qe_port);
+	if (ret) {
+		dev_err(port->dev, "could not claim IRQ %u\n", port->irq);
+		return ret;
+	}
+
+	/* Startup rx-int */
+	qe_setbits_be16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX);
+	ucc_slow_enable(qe_port->us_private, COMM_DIR_RX_AND_TX);
+
+	return 0;
+}
+
+/*
+ * Shutdown the port.
+ */
+static void qe_uart_shutdown(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	unsigned int timeout = 20;
+
+	/* Disable RX and TX */
+
+	/* Wait for all the BDs marked sent */
+	while (!qe_uart_tx_empty(port)) {
+		if (!--timeout) {
+			dev_warn(port->dev, "shutdown timeout\n");
+			break;
+		}
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(2);
+	}
+
+	if (qe_port->wait_closing) {
+		/* Wait a bit longer */
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(qe_port->wait_closing);
+	}
+
+	/* Stop uarts */
+	ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX);
+	qe_clrbits_be16(&uccp->uccm, UCC_UART_UCCE_TX | UCC_UART_UCCE_RX);
+
+	/* Shut them really down and reinit buffer descriptors */
+	ucc_slow_graceful_stop_tx(qe_port->us_private);
+	qe_uart_initbd(qe_port);
+
+	free_irq(port->irq, qe_port);
+}
+
+/*
+ * Set the serial port parameters.
+ */
+static void qe_uart_set_termios(struct uart_port *port,
+				struct ktermios *termios,
+				const struct ktermios *old)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	unsigned int baud;
+	unsigned long flags;
+	u16 upsmr = ioread16be(&uccp->upsmr);
+	struct ucc_uart_pram __iomem *uccup = qe_port->uccup;
+	u16 supsmr = ioread16be(&uccup->supsmr);
+
+	/* byte size */
+	upsmr &= UCC_UART_UPSMR_CL_MASK;
+	supsmr &= UCC_UART_SUPSMR_CL_MASK;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		upsmr |= UCC_UART_UPSMR_CL_5;
+		supsmr |= UCC_UART_SUPSMR_CL_5;
+		break;
+	case CS6:
+		upsmr |= UCC_UART_UPSMR_CL_6;
+		supsmr |= UCC_UART_SUPSMR_CL_6;
+		break;
+	case CS7:
+		upsmr |= UCC_UART_UPSMR_CL_7;
+		supsmr |= UCC_UART_SUPSMR_CL_7;
+		break;
+	default:	/* case CS8 */
+		upsmr |= UCC_UART_UPSMR_CL_8;
+		supsmr |= UCC_UART_SUPSMR_CL_8;
+		break;
+	}
+
+	/* If CSTOPB is set, we want two stop bits */
+	if (termios->c_cflag & CSTOPB) {
+		upsmr |= UCC_UART_UPSMR_SL;
+		supsmr |= UCC_UART_SUPSMR_SL;
+	}
+
+	if (termios->c_cflag & PARENB) {
+		upsmr |= UCC_UART_UPSMR_PEN;
+		supsmr |= UCC_UART_SUPSMR_PEN;
+
+		if (!(termios->c_cflag & PARODD)) {
+			upsmr &= ~(UCC_UART_UPSMR_RPM_MASK |
+				   UCC_UART_UPSMR_TPM_MASK);
+			upsmr |= UCC_UART_UPSMR_RPM_EVEN |
+				UCC_UART_UPSMR_TPM_EVEN;
+			supsmr &= ~(UCC_UART_SUPSMR_RPM_MASK |
+				    UCC_UART_SUPSMR_TPM_MASK);
+			supsmr |= UCC_UART_SUPSMR_RPM_EVEN |
+				UCC_UART_SUPSMR_TPM_EVEN;
+		}
+	}
+
+	/*
+	 * Set up parity check flag
+	 */
+	port->read_status_mask = BD_SC_EMPTY | BD_SC_OV;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= BD_SC_FR | BD_SC_PR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= BD_SC_BR;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= BD_SC_PR | BD_SC_FR;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= BD_SC_BR;
+		/*
+		 * If we're ignore parity and break indicators, ignore
+		 * overruns too.  (For real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= BD_SC_OV;
+	}
+	/*
+	 * !!! ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->read_status_mask &= ~BD_SC_EMPTY;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+
+	/* Do we really need a spinlock here? */
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Update the per-port timeout. */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	iowrite16be(upsmr, &uccp->upsmr);
+	if (soft_uart) {
+		iowrite16be(supsmr, &uccup->supsmr);
+		iowrite8(tty_get_frame_size(termios->c_cflag), &uccup->rx_length);
+
+		/* Soft-UART requires a 1X multiplier for TX */
+		qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
+		qe_setbrg(qe_port->us_info.tx_clock, baud, 1);
+	} else {
+		qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
+		qe_setbrg(qe_port->us_info.tx_clock, baud, 16);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * Return a pointer to a string that describes what kind of port this is.
+ */
+static const char *qe_uart_type(struct uart_port *port)
+{
+	return "QE";
+}
+
+/*
+ * Allocate any memory and I/O resources required by the port.
+ */
+static int qe_uart_request_port(struct uart_port *port)
+{
+	int ret;
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow_info *us_info = &qe_port->us_info;
+	struct ucc_slow_private *uccs;
+	unsigned int rx_size, tx_size;
+	void *bd_virt;
+	dma_addr_t bd_dma_addr = 0;
+
+	ret = ucc_slow_init(us_info, &uccs);
+	if (ret) {
+		dev_err(port->dev, "could not initialize UCC%u\n",
+		       qe_port->ucc_num);
+		return ret;
+	}
+
+	qe_port->us_private = uccs;
+	qe_port->uccp = uccs->us_regs;
+	qe_port->uccup = (struct ucc_uart_pram *) uccs->us_pram;
+	qe_port->rx_bd_base = uccs->rx_bd;
+	qe_port->tx_bd_base = uccs->tx_bd;
+
+	/*
+	 * Allocate the transmit and receive data buffers.
+	 */
+
+	rx_size = L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize);
+	tx_size = L1_CACHE_ALIGN(qe_port->tx_nrfifos * qe_port->tx_fifosize);
+
+	bd_virt = dma_alloc_coherent(port->dev, rx_size + tx_size, &bd_dma_addr,
+		GFP_KERNEL);
+	if (!bd_virt) {
+		dev_err(port->dev, "could not allocate buffer descriptors\n");
+		return -ENOMEM;
+	}
+
+	qe_port->bd_virt = bd_virt;
+	qe_port->bd_dma_addr = bd_dma_addr;
+	qe_port->bd_size = rx_size + tx_size;
+
+	qe_port->rx_buf = bd_virt;
+	qe_port->tx_buf = qe_port->rx_buf + rx_size;
+
+	return 0;
+}
+
+/*
+ * Configure the port.
+ *
+ * We say we're a CPM-type port because that's mostly true.  Once the device
+ * is configured, this driver operates almost identically to the CPM serial
+ * driver.
+ */
+static void qe_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_CPM;
+		qe_uart_request_port(port);
+	}
+}
+
+/*
+ * Release any memory and I/O resources that were allocated in
+ * qe_uart_request_port().
+ */
+static void qe_uart_release_port(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow_private *uccs = qe_port->us_private;
+
+	dma_free_coherent(port->dev, qe_port->bd_size, qe_port->bd_virt,
+			  qe_port->bd_dma_addr);
+
+	ucc_slow_free(uccs);
+}
+
+/*
+ * Verify that the data in serial_struct is suitable for this device.
+ */
+static int qe_uart_verify_port(struct uart_port *port,
+			       struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_CPM)
+		return -EINVAL;
+
+	if (ser->irq < 0 || ser->irq >= nr_irqs)
+		return -EINVAL;
+
+	if (ser->baud_base < 9600)
+		return -EINVAL;
+
+	return 0;
+}
+/* UART operations
+ *
+ * Details on these functions can be found in Documentation/driver-api/serial/driver.rst
+ */
+static const struct uart_ops qe_uart_pops = {
+	.tx_empty       = qe_uart_tx_empty,
+	.set_mctrl      = qe_uart_set_mctrl,
+	.get_mctrl      = qe_uart_get_mctrl,
+	.stop_tx	= qe_uart_stop_tx,
+	.start_tx       = qe_uart_start_tx,
+	.stop_rx	= qe_uart_stop_rx,
+	.break_ctl      = qe_uart_break_ctl,
+	.startup	= qe_uart_startup,
+	.shutdown       = qe_uart_shutdown,
+	.set_termios    = qe_uart_set_termios,
+	.type   	= qe_uart_type,
+	.release_port   = qe_uart_release_port,
+	.request_port   = qe_uart_request_port,
+	.config_port    = qe_uart_config_port,
+	.verify_port    = qe_uart_verify_port,
+};
+
+
+#ifdef CONFIG_PPC32
+/*
+ * Obtain the SOC model number and revision level
+ *
+ * This function parses the device tree to obtain the SOC model.  It then
+ * reads the SVR register to the revision.
+ *
+ * The device tree stores the SOC model two different ways.
+ *
+ * The new way is:
+ *
+ *      	cpu@0 {
+ *      		compatible = "PowerPC,8323";
+ *      		device_type = "cpu";
+ *      		...
+ *
+ *
+ * The old way is:
+ *      	 PowerPC,8323@0 {
+ *      		device_type = "cpu";
+ *      		...
+ *
+ * This code first checks the new way, and then the old way.
+ */
+static unsigned int soc_info(unsigned int *rev_h, unsigned int *rev_l)
+{
+	struct device_node *np;
+	const char *soc_string;
+	unsigned int svr;
+	unsigned int soc;
+
+	/* Find the CPU node */
+	np = of_find_node_by_type(NULL, "cpu");
+	if (!np)
+		return 0;
+	/* Find the compatible property */
+	soc_string = of_get_property(np, "compatible", NULL);
+	if (!soc_string)
+		/* No compatible property, so try the name. */
+		soc_string = np->name;
+
+	of_node_put(np);
+
+	/* Extract the SOC number from the "PowerPC," string */
+	if ((sscanf(soc_string, "PowerPC,%u", &soc) != 1) || !soc)
+		return 0;
+
+	/* Get the revision from the SVR */
+	svr = mfspr(SPRN_SVR);
+	*rev_h = (svr >> 4) & 0xf;
+	*rev_l = svr & 0xf;
+
+	return soc;
+}
+
+/*
+ * requst_firmware_nowait() callback function
+ *
+ * This function is called by the kernel when a firmware is made available,
+ * or if it times out waiting for the firmware.
+ */
+static void uart_firmware_cont(const struct firmware *fw, void *context)
+{
+	struct qe_firmware *firmware;
+	struct device *dev = context;
+	int ret;
+
+	if (!fw) {
+		dev_err(dev, "firmware not found\n");
+		return;
+	}
+
+	firmware = (struct qe_firmware *) fw->data;
+
+	if (firmware->header.length != fw->size) {
+		dev_err(dev, "invalid firmware\n");
+		goto out;
+	}
+
+	ret = qe_upload_firmware(firmware);
+	if (ret) {
+		dev_err(dev, "could not load firmware\n");
+		goto out;
+	}
+
+	firmware_loaded = 1;
+ out:
+	release_firmware(fw);
+}
+
+static int soft_uart_init(struct platform_device *ofdev)
+{
+	struct device_node *np = ofdev->dev.of_node;
+	struct qe_firmware_info *qe_fw_info;
+	int ret;
+
+	if (of_property_read_bool(np, "soft-uart")) {
+		dev_dbg(&ofdev->dev, "using Soft-UART mode\n");
+		soft_uart = 1;
+	} else {
+		return 0;
+	}
+
+	qe_fw_info = qe_get_firmware_info();
+
+	/* Check if the firmware has been uploaded. */
+	if (qe_fw_info && strstr(qe_fw_info->id, "Soft-UART")) {
+		firmware_loaded = 1;
+	} else {
+		char filename[32];
+		unsigned int soc;
+		unsigned int rev_h;
+		unsigned int rev_l;
+
+		soc = soc_info(&rev_h, &rev_l);
+		if (!soc) {
+			dev_err(&ofdev->dev, "unknown CPU model\n");
+			return -ENXIO;
+		}
+		sprintf(filename, "fsl_qe_ucode_uart_%u_%u%u.bin",
+			soc, rev_h, rev_l);
+
+		dev_info(&ofdev->dev, "waiting for firmware %s\n",
+			 filename);
+
+		/*
+		 * We call request_firmware_nowait instead of
+		 * request_firmware so that the driver can load and
+		 * initialize the ports without holding up the rest of
+		 * the kernel.  If hotplug support is enabled in the
+		 * kernel, then we use it.
+		 */
+		ret = request_firmware_nowait(THIS_MODULE,
+					      FW_ACTION_UEVENT, filename, &ofdev->dev,
+					      GFP_KERNEL, &ofdev->dev, uart_firmware_cont);
+		if (ret) {
+			dev_err(&ofdev->dev,
+				"could not load firmware %s\n",
+				filename);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+#else /* !CONFIG_PPC32 */
+
+static int soft_uart_init(struct platform_device *ofdev)
+{
+	return 0;
+}
+
+#endif
+
+
+static int ucc_uart_probe(struct platform_device *ofdev)
+{
+	struct device_node *np = ofdev->dev.of_node;
+	const char *sprop;      /* String OF properties */
+	struct uart_qe_port *qe_port = NULL;
+	struct resource res;
+	u32 val;
+	int ret;
+
+	/*
+	 * Determine if we need Soft-UART mode
+	 */
+	ret = soft_uart_init(ofdev);
+	if (ret)
+		return ret;
+
+	qe_port = kzalloc(sizeof(struct uart_qe_port), GFP_KERNEL);
+	if (!qe_port) {
+		dev_err(&ofdev->dev, "can't allocate QE port structure\n");
+		return -ENOMEM;
+	}
+
+	/* Search for IRQ and mapbase */
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		dev_err(&ofdev->dev, "missing 'reg' property in device tree\n");
+		goto out_free;
+	}
+	if (!res.start) {
+		dev_err(&ofdev->dev, "invalid 'reg' property in device tree\n");
+		ret = -EINVAL;
+		goto out_free;
+	}
+	qe_port->port.mapbase = res.start;
+
+	/* Get the UCC number (device ID) */
+	/* UCCs are numbered 1-7 */
+	if (of_property_read_u32(np, "cell-index", &val)) {
+		if (of_property_read_u32(np, "device-id", &val)) {
+			dev_err(&ofdev->dev, "UCC is unspecified in device tree\n");
+			ret = -EINVAL;
+			goto out_free;
+		}
+	}
+
+	if (val < 1 || val > UCC_MAX_NUM) {
+		dev_err(&ofdev->dev, "no support for UCC%u\n", val);
+		ret = -ENODEV;
+		goto out_free;
+	}
+	qe_port->ucc_num = val - 1;
+
+	/*
+	 * In the future, we should not require the BRG to be specified in the
+	 * device tree.  If no clock-source is specified, then just pick a BRG
+	 * to use.  This requires a new QE library function that manages BRG
+	 * assignments.
+	 */
+
+	sprop = of_get_property(np, "rx-clock-name", NULL);
+	if (!sprop) {
+		dev_err(&ofdev->dev, "missing rx-clock-name in device tree\n");
+		ret = -ENODEV;
+		goto out_free;
+	}
+
+	qe_port->us_info.rx_clock = qe_clock_source(sprop);
+	if ((qe_port->us_info.rx_clock < QE_BRG1) ||
+	    (qe_port->us_info.rx_clock > QE_BRG16)) {
+		dev_err(&ofdev->dev, "rx-clock-name must be a BRG for UART\n");
+		ret = -ENODEV;
+		goto out_free;
+	}
+
+#ifdef LOOPBACK
+	/* In internal loopback mode, TX and RX must use the same clock */
+	qe_port->us_info.tx_clock = qe_port->us_info.rx_clock;
+#else
+	sprop = of_get_property(np, "tx-clock-name", NULL);
+	if (!sprop) {
+		dev_err(&ofdev->dev, "missing tx-clock-name in device tree\n");
+		ret = -ENODEV;
+		goto out_free;
+	}
+	qe_port->us_info.tx_clock = qe_clock_source(sprop);
+#endif
+	if ((qe_port->us_info.tx_clock < QE_BRG1) ||
+	    (qe_port->us_info.tx_clock > QE_BRG16)) {
+		dev_err(&ofdev->dev, "tx-clock-name must be a BRG for UART\n");
+		ret = -ENODEV;
+		goto out_free;
+	}
+
+	/* Get the port number, numbered 0-3 */
+	if (of_property_read_u32(np, "port-number", &val)) {
+		dev_err(&ofdev->dev, "missing port-number in device tree\n");
+		ret = -EINVAL;
+		goto out_free;
+	}
+	qe_port->port.line = val;
+	if (qe_port->port.line >= UCC_MAX_UART) {
+		dev_err(&ofdev->dev, "port-number must be 0-%u\n",
+			UCC_MAX_UART - 1);
+		ret = -EINVAL;
+		goto out_free;
+	}
+
+	qe_port->port.irq = irq_of_parse_and_map(np, 0);
+	if (qe_port->port.irq == 0) {
+		dev_err(&ofdev->dev, "could not map IRQ for UCC%u\n",
+		       qe_port->ucc_num + 1);
+		ret = -EINVAL;
+		goto out_free;
+	}
+
+	/*
+	 * Newer device trees have an "fsl,qe" compatible property for the QE
+	 * node, but we still need to support older device trees.
+	 */
+	np = of_find_compatible_node(NULL, NULL, "fsl,qe");
+	if (!np) {
+		np = of_find_node_by_type(NULL, "qe");
+		if (!np) {
+			dev_err(&ofdev->dev, "could not find 'qe' node\n");
+			ret = -EINVAL;
+			goto out_free;
+		}
+	}
+
+	if (of_property_read_u32(np, "brg-frequency", &val)) {
+		dev_err(&ofdev->dev,
+		       "missing brg-frequency in device tree\n");
+		ret = -EINVAL;
+		goto out_np;
+	}
+
+	if (val)
+		qe_port->port.uartclk = val;
+	else {
+		if (!IS_ENABLED(CONFIG_PPC32)) {
+			dev_err(&ofdev->dev,
+				"invalid brg-frequency in device tree\n");
+			ret = -EINVAL;
+			goto out_np;
+		}
+
+		/*
+		 * Older versions of U-Boot do not initialize the brg-frequency
+		 * property, so in this case we assume the BRG frequency is
+		 * half the QE bus frequency.
+		 */
+		if (of_property_read_u32(np, "bus-frequency", &val)) {
+			dev_err(&ofdev->dev,
+				"missing QE bus-frequency in device tree\n");
+			ret = -EINVAL;
+			goto out_np;
+		}
+		if (val)
+			qe_port->port.uartclk = val / 2;
+		else {
+			dev_err(&ofdev->dev,
+				"invalid QE bus-frequency in device tree\n");
+			ret = -EINVAL;
+			goto out_np;
+		}
+	}
+
+	spin_lock_init(&qe_port->port.lock);
+	qe_port->np = np;
+	qe_port->port.dev = &ofdev->dev;
+	qe_port->port.ops = &qe_uart_pops;
+	qe_port->port.iotype = UPIO_MEM;
+
+	qe_port->tx_nrfifos = TX_NUM_FIFO;
+	qe_port->tx_fifosize = TX_BUF_SIZE;
+	qe_port->rx_nrfifos = RX_NUM_FIFO;
+	qe_port->rx_fifosize = RX_BUF_SIZE;
+
+	qe_port->wait_closing = UCC_WAIT_CLOSING;
+	qe_port->port.fifosize = 512;
+	qe_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+
+	qe_port->us_info.ucc_num = qe_port->ucc_num;
+	qe_port->us_info.regs = (phys_addr_t) res.start;
+	qe_port->us_info.irq = qe_port->port.irq;
+
+	qe_port->us_info.rx_bd_ring_len = qe_port->rx_nrfifos;
+	qe_port->us_info.tx_bd_ring_len = qe_port->tx_nrfifos;
+
+	/* Make sure ucc_slow_init() initializes both TX and RX */
+	qe_port->us_info.init_tx = 1;
+	qe_port->us_info.init_rx = 1;
+
+	/* Add the port to the uart sub-system.  This will cause
+	 * qe_uart_config_port() to be called, so the us_info structure must
+	 * be initialized.
+	 */
+	ret = uart_add_one_port(&ucc_uart_driver, &qe_port->port);
+	if (ret) {
+		dev_err(&ofdev->dev, "could not add /dev/ttyQE%u\n",
+		       qe_port->port.line);
+		goto out_np;
+	}
+
+	platform_set_drvdata(ofdev, qe_port);
+
+	dev_info(&ofdev->dev, "UCC%u assigned to /dev/ttyQE%u\n",
+		qe_port->ucc_num + 1, qe_port->port.line);
+
+	/* Display the mknod command for this device */
+	dev_dbg(&ofdev->dev, "mknod command is 'mknod /dev/ttyQE%u c %u %u'\n",
+	       qe_port->port.line, SERIAL_QE_MAJOR,
+	       SERIAL_QE_MINOR + qe_port->port.line);
+
+	return 0;
+out_np:
+	of_node_put(np);
+out_free:
+	kfree(qe_port);
+	return ret;
+}
+
+static int ucc_uart_remove(struct platform_device *ofdev)
+{
+	struct uart_qe_port *qe_port = platform_get_drvdata(ofdev);
+
+	dev_info(&ofdev->dev, "removing /dev/ttyQE%u\n", qe_port->port.line);
+
+	uart_remove_one_port(&ucc_uart_driver, &qe_port->port);
+
+	of_node_put(qe_port->np);
+
+	kfree(qe_port);
+
+	return 0;
+}
+
+static const struct of_device_id ucc_uart_match[] = {
+	{
+		.type = "serial",
+		.compatible = "ucc_uart",
+	},
+	{
+		.compatible = "fsl,t1040-ucc-uart",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ucc_uart_match);
+
+static struct platform_driver ucc_uart_of_driver = {
+	.driver = {
+		.name = "ucc_uart",
+		.of_match_table    = ucc_uart_match,
+	},
+	.probe  	= ucc_uart_probe,
+	.remove 	= ucc_uart_remove,
+};
+
+static int __init ucc_uart_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Freescale QUICC Engine UART device driver\n");
+#ifdef LOOPBACK
+	printk(KERN_INFO "ucc-uart: Using loopback mode\n");
+#endif
+
+	ret = uart_register_driver(&ucc_uart_driver);
+	if (ret) {
+		printk(KERN_ERR "ucc-uart: could not register UART driver\n");
+		return ret;
+	}
+
+	ret = platform_driver_register(&ucc_uart_of_driver);
+	if (ret) {
+		printk(KERN_ERR
+		       "ucc-uart: could not register platform driver\n");
+		uart_unregister_driver(&ucc_uart_driver);
+	}
+
+	return ret;
+}
+
+static void __exit ucc_uart_exit(void)
+{
+	printk(KERN_INFO
+	       "Freescale QUICC Engine UART device driver unloading\n");
+
+	platform_driver_unregister(&ucc_uart_of_driver);
+	uart_unregister_driver(&ucc_uart_driver);
+}
+
+module_init(ucc_uart_init);
+module_exit(ucc_uart_exit);
+
+MODULE_DESCRIPTION("Freescale QUICC Engine (QE) UART");
+MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_QE_MAJOR);
+
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
new file mode 100644
index 000000000..c5d5c2765
--- /dev/null
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -0,0 +1,719 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
+ *
+ * Based on msm_serial.c, which is:
+ * Copyright (C) 2007 Google, Inc.
+ * Author: Robert Love <rlove@google.com>
+ */
+
+#include <linux/hrtimer.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/err.h>
+
+/*
+ * UART Register offsets
+ */
+
+#define VT8500_URTDR		0x0000	/* Transmit data */
+#define VT8500_URRDR		0x0004	/* Receive data */
+#define VT8500_URDIV		0x0008	/* Clock/Baud rate divisor */
+#define VT8500_URLCR		0x000C	/* Line control */
+#define VT8500_URICR		0x0010	/* IrDA control */
+#define VT8500_URIER		0x0014	/* Interrupt enable */
+#define VT8500_URISR		0x0018	/* Interrupt status */
+#define VT8500_URUSR		0x001c	/* UART status */
+#define VT8500_URFCR		0x0020	/* FIFO control */
+#define VT8500_URFIDX		0x0024	/* FIFO index */
+#define VT8500_URBKR		0x0028	/* Break signal count */
+#define VT8500_URTOD		0x002c	/* Time out divisor */
+#define VT8500_TXFIFO		0x1000	/* Transmit FIFO (16x8) */
+#define VT8500_RXFIFO		0x1020	/* Receive FIFO (16x10) */
+
+/*
+ * Interrupt enable and status bits
+ */
+
+#define TXDE	(1 << 0)	/* Tx Data empty */
+#define RXDF	(1 << 1)	/* Rx Data full */
+#define TXFAE	(1 << 2)	/* Tx FIFO almost empty */
+#define TXFE	(1 << 3)	/* Tx FIFO empty */
+#define RXFAF	(1 << 4)	/* Rx FIFO almost full */
+#define RXFF	(1 << 5)	/* Rx FIFO full */
+#define TXUDR	(1 << 6)	/* Tx underrun */
+#define RXOVER	(1 << 7)	/* Rx overrun */
+#define PER	(1 << 8)	/* Parity error */
+#define FER	(1 << 9)	/* Frame error */
+#define TCTS	(1 << 10)	/* Toggle of CTS */
+#define RXTOUT	(1 << 11)	/* Rx timeout */
+#define BKDONE	(1 << 12)	/* Break signal done */
+#define ERR	(1 << 13)	/* AHB error response */
+
+#define RX_FIFO_INTS	(RXFAF | RXFF | RXOVER | PER | FER | RXTOUT)
+#define TX_FIFO_INTS	(TXFAE | TXFE | TXUDR)
+
+/*
+ * Line control bits
+ */
+
+#define VT8500_TXEN	(1 << 0)	/* Enable transmit logic */
+#define VT8500_RXEN	(1 << 1)	/* Enable receive logic */
+#define VT8500_CS8	(1 << 2)	/* 8-bit data length (vs. 7-bit) */
+#define VT8500_CSTOPB	(1 << 3)	/* 2 stop bits (vs. 1) */
+#define VT8500_PARENB	(1 << 4)	/* Enable parity */
+#define VT8500_PARODD	(1 << 5)	/* Odd parity (vs. even) */
+#define VT8500_RTS	(1 << 6)	/* Ready to send */
+#define VT8500_LOOPBK	(1 << 7)	/* Enable internal loopback */
+#define VT8500_DMA	(1 << 8)	/* Enable DMA mode (needs FIFO) */
+#define VT8500_BREAK	(1 << 9)	/* Initiate break signal */
+#define VT8500_PSLVERR	(1 << 10)	/* APB error upon empty RX FIFO read */
+#define VT8500_SWRTSCTS	(1 << 11)	/* Software-controlled RTS/CTS */
+
+/*
+ * Capability flags (driver-internal)
+ */
+
+#define VT8500_HAS_SWRTSCTS_SWITCH	(1 << 1)
+
+#define VT8500_RECOMMENDED_CLK		12000000
+#define VT8500_OVERSAMPLING_DIVISOR	13
+#define VT8500_MAX_PORTS	6
+
+struct vt8500_port {
+	struct uart_port	uart;
+	char			name[16];
+	struct clk		*clk;
+	unsigned int		clk_predivisor;
+	unsigned int		ier;
+	unsigned int		vt8500_uart_flags;
+};
+
+/*
+ * we use this variable to keep track of which ports
+ * have been allocated as we can't use pdev->id in
+ * devicetree
+ */
+static DECLARE_BITMAP(vt8500_ports_in_use, VT8500_MAX_PORTS);
+
+static inline void vt8500_write(struct uart_port *port, unsigned int val,
+			     unsigned int off)
+{
+	writel(val, port->membase + off);
+}
+
+static inline unsigned int vt8500_read(struct uart_port *port, unsigned int off)
+{
+	return readl(port->membase + off);
+}
+
+static void vt8500_stop_tx(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port = container_of(port,
+						       struct vt8500_port,
+						       uart);
+
+	vt8500_port->ier &= ~TX_FIFO_INTS;
+	vt8500_write(port, vt8500_port->ier, VT8500_URIER);
+}
+
+static void vt8500_stop_rx(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port = container_of(port,
+						       struct vt8500_port,
+						       uart);
+
+	vt8500_port->ier &= ~RX_FIFO_INTS;
+	vt8500_write(port, vt8500_port->ier, VT8500_URIER);
+}
+
+static void vt8500_enable_ms(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port = container_of(port,
+						       struct vt8500_port,
+						       uart);
+
+	vt8500_port->ier |= TCTS;
+	vt8500_write(port, vt8500_port->ier, VT8500_URIER);
+}
+
+static void handle_rx(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+
+	/*
+	 * Handle overrun
+	 */
+	if ((vt8500_read(port, VT8500_URISR) & RXOVER)) {
+		port->icount.overrun++;
+		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+	}
+
+	/* and now the main RX loop */
+	while (vt8500_read(port, VT8500_URFIDX) & 0x1f00) {
+		unsigned int c;
+		char flag = TTY_NORMAL;
+
+		c = readw(port->membase + VT8500_RXFIFO) & 0x3ff;
+
+		/* Mask conditions we're ignoring. */
+		c &= ~port->read_status_mask;
+
+		if (c & FER) {
+			port->icount.frame++;
+			flag = TTY_FRAME;
+		} else if (c & PER) {
+			port->icount.parity++;
+			flag = TTY_PARITY;
+		}
+		port->icount.rx++;
+
+		if (!uart_handle_sysrq_char(port, c))
+			tty_insert_flip_char(tport, c, flag);
+	}
+
+	tty_flip_buffer_push(tport);
+}
+
+static unsigned int vt8500_tx_empty(struct uart_port *port)
+{
+	unsigned int idx = vt8500_read(port, VT8500_URFIDX) & 0x1f;
+
+	return idx < 16 ? TIOCSER_TEMT : 0;
+}
+
+static void handle_tx(struct uart_port *port)
+{
+	u8 ch;
+
+	uart_port_tx(port, ch,
+		vt8500_tx_empty(port),
+		writeb(ch, port->membase + VT8500_TXFIFO));
+}
+
+static void vt8500_start_tx(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port = container_of(port,
+						       struct vt8500_port,
+						       uart);
+
+	vt8500_port->ier &= ~TX_FIFO_INTS;
+	vt8500_write(port, vt8500_port->ier, VT8500_URIER);
+	handle_tx(port);
+	vt8500_port->ier |= TX_FIFO_INTS;
+	vt8500_write(port, vt8500_port->ier, VT8500_URIER);
+}
+
+static void handle_delta_cts(struct uart_port *port)
+{
+	port->icount.cts++;
+	wake_up_interruptible(&port->state->port.delta_msr_wait);
+}
+
+static irqreturn_t vt8500_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned long isr;
+
+	spin_lock(&port->lock);
+	isr = vt8500_read(port, VT8500_URISR);
+
+	/* Acknowledge active status bits */
+	vt8500_write(port, isr, VT8500_URISR);
+
+	if (isr & RX_FIFO_INTS)
+		handle_rx(port);
+	if (isr & TX_FIFO_INTS)
+		handle_tx(port);
+	if (isr & TCTS)
+		handle_delta_cts(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int vt8500_get_mctrl(struct uart_port *port)
+{
+	unsigned int usr;
+
+	usr = vt8500_read(port, VT8500_URUSR);
+	if (usr & (1 << 4))
+		return TIOCM_CTS;
+	else
+		return 0;
+}
+
+static void vt8500_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int lcr = vt8500_read(port, VT8500_URLCR);
+
+	if (mctrl & TIOCM_RTS)
+		lcr |= VT8500_RTS;
+	else
+		lcr &= ~VT8500_RTS;
+
+	vt8500_write(port, lcr, VT8500_URLCR);
+}
+
+static void vt8500_break_ctl(struct uart_port *port, int break_ctl)
+{
+	if (break_ctl)
+		vt8500_write(port,
+			     vt8500_read(port, VT8500_URLCR) | VT8500_BREAK,
+			     VT8500_URLCR);
+}
+
+static int vt8500_set_baud_rate(struct uart_port *port, unsigned int baud)
+{
+	struct vt8500_port *vt8500_port =
+			container_of(port, struct vt8500_port, uart);
+	unsigned long div;
+	unsigned int loops = 1000;
+
+	div = ((vt8500_port->clk_predivisor - 1) & 0xf) << 16;
+	div |= (uart_get_divisor(port, baud) - 1) & 0x3ff;
+
+	/* Effective baud rate */
+	baud = port->uartclk / 16 / ((div & 0x3ff) + 1);
+
+	while ((vt8500_read(port, VT8500_URUSR) & (1 << 5)) && --loops)
+		cpu_relax();
+
+	vt8500_write(port, div, VT8500_URDIV);
+
+	/* Break signal timing depends on baud rate, update accordingly */
+	vt8500_write(port, mult_frac(baud, 4096, 1000000), VT8500_URBKR);
+
+	return baud;
+}
+
+static int vt8500_startup(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port =
+			container_of(port, struct vt8500_port, uart);
+	int ret;
+
+	snprintf(vt8500_port->name, sizeof(vt8500_port->name),
+		 "vt8500_serial%d", port->line);
+
+	ret = request_irq(port->irq, vt8500_irq, IRQF_TRIGGER_HIGH,
+			  vt8500_port->name, port);
+	if (unlikely(ret))
+		return ret;
+
+	vt8500_write(port, 0x03, VT8500_URLCR);	/* enable TX & RX */
+
+	return 0;
+}
+
+static void vt8500_shutdown(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port =
+			container_of(port, struct vt8500_port, uart);
+
+	vt8500_port->ier = 0;
+
+	/* disable interrupts and FIFOs */
+	vt8500_write(&vt8500_port->uart, 0, VT8500_URIER);
+	vt8500_write(&vt8500_port->uart, 0x880, VT8500_URFCR);
+	free_irq(port->irq, port);
+}
+
+static void vt8500_set_termios(struct uart_port *port,
+			       struct ktermios *termios,
+			       const struct ktermios *old)
+{
+	struct vt8500_port *vt8500_port =
+			container_of(port, struct vt8500_port, uart);
+	unsigned long flags;
+	unsigned int baud, lcr;
+	unsigned int loops = 1000;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* calculate and set baud rate */
+	baud = uart_get_baud_rate(port, termios, old, 900, 921600);
+	baud = vt8500_set_baud_rate(port, baud);
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	/* calculate parity */
+	lcr = vt8500_read(&vt8500_port->uart, VT8500_URLCR);
+	lcr &= ~(VT8500_PARENB | VT8500_PARODD);
+	if (termios->c_cflag & PARENB) {
+		lcr |= VT8500_PARENB;
+		termios->c_cflag &= ~CMSPAR;
+		if (termios->c_cflag & PARODD)
+			lcr |= VT8500_PARODD;
+	}
+
+	/* calculate bits per char */
+	lcr &= ~VT8500_CS8;
+	switch (termios->c_cflag & CSIZE) {
+	case CS7:
+		break;
+	case CS8:
+	default:
+		lcr |= VT8500_CS8;
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+		break;
+	}
+
+	/* calculate stop bits */
+	lcr &= ~VT8500_CSTOPB;
+	if (termios->c_cflag & CSTOPB)
+		lcr |= VT8500_CSTOPB;
+
+	lcr &= ~VT8500_SWRTSCTS;
+	if (vt8500_port->vt8500_uart_flags & VT8500_HAS_SWRTSCTS_SWITCH)
+		lcr |= VT8500_SWRTSCTS;
+
+	/* set parity, bits per char, and stop bit */
+	vt8500_write(&vt8500_port->uart, lcr, VT8500_URLCR);
+
+	/* Configure status bits to ignore based on termio flags. */
+	port->read_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->read_status_mask = FER | PER;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* Reset FIFOs */
+	vt8500_write(&vt8500_port->uart, 0x88c, VT8500_URFCR);
+	while ((vt8500_read(&vt8500_port->uart, VT8500_URFCR) & 0xc)
+							&& --loops)
+		cpu_relax();
+
+	/* Every possible FIFO-related interrupt */
+	vt8500_port->ier = RX_FIFO_INTS | TX_FIFO_INTS;
+
+	/*
+	 * CTS flow control
+	 */
+	if (UART_ENABLE_MS(&vt8500_port->uart, termios->c_cflag))
+		vt8500_port->ier |= TCTS;
+
+	vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
+	vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *vt8500_type(struct uart_port *port)
+{
+	struct vt8500_port *vt8500_port =
+			container_of(port, struct vt8500_port, uart);
+	return vt8500_port->name;
+}
+
+static void vt8500_release_port(struct uart_port *port)
+{
+}
+
+static int vt8500_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void vt8500_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_VT8500;
+}
+
+static int vt8500_verify_port(struct uart_port *port,
+			      struct serial_struct *ser)
+{
+	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_VT8500))
+		return -EINVAL;
+	if (unlikely(port->irq != ser->irq))
+		return -EINVAL;
+	return 0;
+}
+
+static struct vt8500_port *vt8500_uart_ports[VT8500_MAX_PORTS];
+static struct uart_driver vt8500_uart_driver;
+
+#ifdef CONFIG_SERIAL_VT8500_CONSOLE
+
+static void wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	do {
+		status = vt8500_read(port, VT8500_URFIDX);
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (status & 0x10);
+}
+
+static void vt8500_console_putchar(struct uart_port *port, unsigned char c)
+{
+	wait_for_xmitr(port);
+	writeb(c, port->membase + VT8500_TXFIFO);
+}
+
+static void vt8500_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	struct vt8500_port *vt8500_port = vt8500_uart_ports[co->index];
+	unsigned long ier;
+
+	BUG_ON(co->index < 0 || co->index >= vt8500_uart_driver.nr);
+
+	ier = vt8500_read(&vt8500_port->uart, VT8500_URIER);
+	vt8500_write(&vt8500_port->uart, VT8500_URIER, 0);
+
+	uart_console_write(&vt8500_port->uart, s, count,
+			   vt8500_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and switch back to FIFO
+	 */
+	wait_for_xmitr(&vt8500_port->uart);
+	vt8500_write(&vt8500_port->uart, VT8500_URIER, ier);
+}
+
+static int __init vt8500_console_setup(struct console *co, char *options)
+{
+	struct vt8500_port *vt8500_port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (unlikely(co->index >= vt8500_uart_driver.nr || co->index < 0))
+		return -ENXIO;
+
+	vt8500_port = vt8500_uart_ports[co->index];
+
+	if (!vt8500_port)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&vt8500_port->uart,
+				 co, baud, parity, bits, flow);
+}
+
+static struct console vt8500_console = {
+	.name = "ttyWMT",
+	.write = vt8500_console_write,
+	.device = uart_console_device,
+	.setup = vt8500_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &vt8500_uart_driver,
+};
+
+#define VT8500_CONSOLE	(&vt8500_console)
+
+#else
+#define VT8500_CONSOLE	NULL
+#endif
+
+#ifdef CONFIG_CONSOLE_POLL
+static int vt8500_get_poll_char(struct uart_port *port)
+{
+	unsigned int status = vt8500_read(port, VT8500_URFIDX);
+
+	if (!(status & 0x1f00))
+		return NO_POLL_CHAR;
+
+	return vt8500_read(port, VT8500_RXFIFO) & 0xff;
+}
+
+static void vt8500_put_poll_char(struct uart_port *port, unsigned char c)
+{
+	unsigned int status, tmout = 10000;
+
+	do {
+		status = vt8500_read(port, VT8500_URFIDX);
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (status & 0x10);
+
+	vt8500_write(port, c, VT8500_TXFIFO);
+}
+#endif
+
+static const struct uart_ops vt8500_uart_pops = {
+	.tx_empty	= vt8500_tx_empty,
+	.set_mctrl	= vt8500_set_mctrl,
+	.get_mctrl	= vt8500_get_mctrl,
+	.stop_tx	= vt8500_stop_tx,
+	.start_tx	= vt8500_start_tx,
+	.stop_rx	= vt8500_stop_rx,
+	.enable_ms	= vt8500_enable_ms,
+	.break_ctl	= vt8500_break_ctl,
+	.startup	= vt8500_startup,
+	.shutdown	= vt8500_shutdown,
+	.set_termios	= vt8500_set_termios,
+	.type		= vt8500_type,
+	.release_port	= vt8500_release_port,
+	.request_port	= vt8500_request_port,
+	.config_port	= vt8500_config_port,
+	.verify_port	= vt8500_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= vt8500_get_poll_char,
+	.poll_put_char	= vt8500_put_poll_char,
+#endif
+};
+
+static struct uart_driver vt8500_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "vt8500_serial",
+	.dev_name	= "ttyWMT",
+	.nr		= 6,
+	.cons		= VT8500_CONSOLE,
+};
+
+static unsigned int vt8500_flags; /* none required so far */
+static unsigned int wm8880_flags = VT8500_HAS_SWRTSCTS_SWITCH;
+
+static const struct of_device_id wmt_dt_ids[] = {
+	{ .compatible = "via,vt8500-uart", .data = &vt8500_flags},
+	{ .compatible = "wm,wm8880-uart", .data = &wm8880_flags},
+	{}
+};
+
+static int vt8500_serial_probe(struct platform_device *pdev)
+{
+	struct vt8500_port *vt8500_port;
+	struct resource *mmres;
+	struct device_node *np = pdev->dev.of_node;
+	const unsigned int *flags;
+	int ret;
+	int port;
+	int irq;
+
+	flags = of_device_get_match_data(&pdev->dev);
+	if (!flags)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	if (np) {
+		port = of_alias_get_id(np, "serial");
+		if (port >= VT8500_MAX_PORTS)
+			port = -1;
+	} else {
+		port = -1;
+	}
+
+	if (port < 0) {
+		/* calculate the port id */
+		port = find_first_zero_bit(vt8500_ports_in_use,
+					   VT8500_MAX_PORTS);
+	}
+
+	if (port >= VT8500_MAX_PORTS)
+		return -ENODEV;
+
+	/* reserve the port id */
+	if (test_and_set_bit(port, vt8500_ports_in_use)) {
+		/* port already in use - shouldn't really happen */
+		return -EBUSY;
+	}
+
+	vt8500_port = devm_kzalloc(&pdev->dev, sizeof(struct vt8500_port),
+				   GFP_KERNEL);
+	if (!vt8500_port)
+		return -ENOMEM;
+
+	vt8500_port->uart.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &mmres);
+	if (IS_ERR(vt8500_port->uart.membase))
+		return PTR_ERR(vt8500_port->uart.membase);
+
+	vt8500_port->clk = of_clk_get(pdev->dev.of_node, 0);
+	if (IS_ERR(vt8500_port->clk)) {
+		dev_err(&pdev->dev, "failed to get clock\n");
+		return  -EINVAL;
+	}
+
+	ret = clk_prepare_enable(vt8500_port->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clock\n");
+		return ret;
+	}
+
+	vt8500_port->vt8500_uart_flags = *flags;
+	vt8500_port->clk_predivisor = DIV_ROUND_CLOSEST(
+					clk_get_rate(vt8500_port->clk),
+					VT8500_RECOMMENDED_CLK
+				      );
+	vt8500_port->uart.type = PORT_VT8500;
+	vt8500_port->uart.iotype = UPIO_MEM;
+	vt8500_port->uart.mapbase = mmres->start;
+	vt8500_port->uart.irq = irq;
+	vt8500_port->uart.fifosize = 16;
+	vt8500_port->uart.ops = &vt8500_uart_pops;
+	vt8500_port->uart.line = port;
+	vt8500_port->uart.dev = &pdev->dev;
+	vt8500_port->uart.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
+	vt8500_port->uart.has_sysrq = IS_ENABLED(CONFIG_SERIAL_VT8500_CONSOLE);
+
+	/* Serial core uses the magic "16" everywhere - adjust for it */
+	vt8500_port->uart.uartclk = 16 * clk_get_rate(vt8500_port->clk) /
+					vt8500_port->clk_predivisor /
+					VT8500_OVERSAMPLING_DIVISOR;
+
+	snprintf(vt8500_port->name, sizeof(vt8500_port->name),
+		 "VT8500 UART%d", pdev->id);
+
+	vt8500_uart_ports[port] = vt8500_port;
+
+	uart_add_one_port(&vt8500_uart_driver, &vt8500_port->uart);
+
+	platform_set_drvdata(pdev, vt8500_port);
+
+	return 0;
+}
+
+static struct platform_driver vt8500_platform_driver = {
+	.probe  = vt8500_serial_probe,
+	.driver = {
+		.name = "vt8500_serial",
+		.of_match_table = wmt_dt_ids,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init vt8500_serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&vt8500_uart_driver);
+	if (unlikely(ret))
+		return ret;
+
+	ret = platform_driver_register(&vt8500_platform_driver);
+
+	if (unlikely(ret))
+		uart_unregister_driver(&vt8500_uart_driver);
+
+	return ret;
+}
+device_initcall(vt8500_serial_init);
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
new file mode 100644
index 000000000..2e5e86a00
--- /dev/null
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -0,0 +1,1726 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Cadence UART driver (found in Xilinx Zynq)
+ *
+ * Copyright (c) 2011 - 2014 Xilinx, Inc.
+ *
+ * This driver has originally been pushed by Xilinx using a Zynq-branding. This
+ * still shows in the naming of this file, the kconfig symbols and some symbols
+ * in the code.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/iopoll.h>
+
+#define CDNS_UART_TTY_NAME	"ttyPS"
+#define CDNS_UART_NAME		"xuartps"
+#define CDNS_UART_MAJOR		0	/* use dynamic node allocation */
+#define CDNS_UART_MINOR		0	/* works best with devtmpfs */
+#define CDNS_UART_NR_PORTS	16
+#define CDNS_UART_FIFO_SIZE	64	/* FIFO size */
+#define CDNS_UART_REGISTER_SPACE	0x1000
+#define TX_TIMEOUT		500000
+
+/* Rx Trigger level */
+static int rx_trigger_level = 56;
+module_param(rx_trigger_level, uint, 0444);
+MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
+
+/* Rx Timeout */
+static int rx_timeout = 10;
+module_param(rx_timeout, uint, 0444);
+MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
+
+/* Register offsets for the UART. */
+#define CDNS_UART_CR		0x00  /* Control Register */
+#define CDNS_UART_MR		0x04  /* Mode Register */
+#define CDNS_UART_IER		0x08  /* Interrupt Enable */
+#define CDNS_UART_IDR		0x0C  /* Interrupt Disable */
+#define CDNS_UART_IMR		0x10  /* Interrupt Mask */
+#define CDNS_UART_ISR		0x14  /* Interrupt Status */
+#define CDNS_UART_BAUDGEN	0x18  /* Baud Rate Generator */
+#define CDNS_UART_RXTOUT	0x1C  /* RX Timeout */
+#define CDNS_UART_RXWM		0x20  /* RX FIFO Trigger Level */
+#define CDNS_UART_MODEMCR	0x24  /* Modem Control */
+#define CDNS_UART_MODEMSR	0x28  /* Modem Status */
+#define CDNS_UART_SR		0x2C  /* Channel Status */
+#define CDNS_UART_FIFO		0x30  /* FIFO */
+#define CDNS_UART_BAUDDIV	0x34  /* Baud Rate Divider */
+#define CDNS_UART_FLOWDEL	0x38  /* Flow Delay */
+#define CDNS_UART_IRRX_PWIDTH	0x3C  /* IR Min Received Pulse Width */
+#define CDNS_UART_IRTX_PWIDTH	0x40  /* IR Transmitted pulse Width */
+#define CDNS_UART_TXWM		0x44  /* TX FIFO Trigger Level */
+#define CDNS_UART_RXBS		0x48  /* RX FIFO byte status register */
+
+/* Control Register Bit Definitions */
+#define CDNS_UART_CR_STOPBRK	0x00000100  /* Stop TX break */
+#define CDNS_UART_CR_STARTBRK	0x00000080  /* Set TX break */
+#define CDNS_UART_CR_TX_DIS	0x00000020  /* TX disabled. */
+#define CDNS_UART_CR_TX_EN	0x00000010  /* TX enabled */
+#define CDNS_UART_CR_RX_DIS	0x00000008  /* RX disabled. */
+#define CDNS_UART_CR_RX_EN	0x00000004  /* RX enabled */
+#define CDNS_UART_CR_TXRST	0x00000002  /* TX logic reset */
+#define CDNS_UART_CR_RXRST	0x00000001  /* RX logic reset */
+#define CDNS_UART_CR_RST_TO	0x00000040  /* Restart Timeout Counter */
+#define CDNS_UART_RXBS_PARITY    0x00000001 /* Parity error status */
+#define CDNS_UART_RXBS_FRAMING   0x00000002 /* Framing error status */
+#define CDNS_UART_RXBS_BRK       0x00000004 /* Overrun error status */
+
+/*
+ * Mode Register:
+ * The mode register (MR) defines the mode of transfer as well as the data
+ * format. If this register is modified during transmission or reception,
+ * data validity cannot be guaranteed.
+ */
+#define CDNS_UART_MR_CLKSEL		0x00000001  /* Pre-scalar selection */
+#define CDNS_UART_MR_CHMODE_L_LOOP	0x00000200  /* Local loop back mode */
+#define CDNS_UART_MR_CHMODE_NORM	0x00000000  /* Normal mode */
+#define CDNS_UART_MR_CHMODE_MASK	0x00000300  /* Mask for mode bits */
+
+#define CDNS_UART_MR_STOPMODE_2_BIT	0x00000080  /* 2 stop bits */
+#define CDNS_UART_MR_STOPMODE_1_BIT	0x00000000  /* 1 stop bit */
+
+#define CDNS_UART_MR_PARITY_NONE	0x00000020  /* No parity mode */
+#define CDNS_UART_MR_PARITY_MARK	0x00000018  /* Mark parity mode */
+#define CDNS_UART_MR_PARITY_SPACE	0x00000010  /* Space parity mode */
+#define CDNS_UART_MR_PARITY_ODD		0x00000008  /* Odd parity mode */
+#define CDNS_UART_MR_PARITY_EVEN	0x00000000  /* Even parity mode */
+
+#define CDNS_UART_MR_CHARLEN_6_BIT	0x00000006  /* 6 bits data */
+#define CDNS_UART_MR_CHARLEN_7_BIT	0x00000004  /* 7 bits data */
+#define CDNS_UART_MR_CHARLEN_8_BIT	0x00000000  /* 8 bits data */
+
+/*
+ * Interrupt Registers:
+ * Interrupt control logic uses the interrupt enable register (IER) and the
+ * interrupt disable register (IDR) to set the value of the bits in the
+ * interrupt mask register (IMR). The IMR determines whether to pass an
+ * interrupt to the interrupt status register (ISR).
+ * Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
+ * interrupt. IMR and ISR are read only, and IER and IDR are write only.
+ * Reading either IER or IDR returns 0x00.
+ * All four registers have the same bit definitions.
+ */
+#define CDNS_UART_IXR_TOUT	0x00000100 /* RX Timeout error interrupt */
+#define CDNS_UART_IXR_PARITY	0x00000080 /* Parity error interrupt */
+#define CDNS_UART_IXR_FRAMING	0x00000040 /* Framing error interrupt */
+#define CDNS_UART_IXR_OVERRUN	0x00000020 /* Overrun error interrupt */
+#define CDNS_UART_IXR_TXFULL	0x00000010 /* TX FIFO Full interrupt */
+#define CDNS_UART_IXR_TXEMPTY	0x00000008 /* TX FIFO empty interrupt */
+#define CDNS_UART_ISR_RXEMPTY	0x00000002 /* RX FIFO empty interrupt */
+#define CDNS_UART_IXR_RXTRIG	0x00000001 /* RX FIFO trigger interrupt */
+#define CDNS_UART_IXR_RXFULL	0x00000004 /* RX FIFO full interrupt. */
+#define CDNS_UART_IXR_RXEMPTY	0x00000002 /* RX FIFO empty interrupt. */
+#define CDNS_UART_IXR_RXMASK	0x000021e7 /* Valid RX bit mask */
+
+	/*
+	 * Do not enable parity error interrupt for the following
+	 * reason: When parity error interrupt is enabled, each Rx
+	 * parity error always results in 2 events. The first one
+	 * being parity error interrupt and the second one with a
+	 * proper Rx interrupt with the incoming data.  Disabling
+	 * parity error interrupt ensures better handling of parity
+	 * error events. With this change, for a parity error case, we
+	 * get a Rx interrupt with parity error set in ISR register
+	 * and we still handle parity errors in the desired way.
+	 */
+
+#define CDNS_UART_RX_IRQS	(CDNS_UART_IXR_FRAMING | \
+				 CDNS_UART_IXR_OVERRUN | \
+				 CDNS_UART_IXR_RXTRIG |	 \
+				 CDNS_UART_IXR_TOUT)
+
+/* Goes in read_status_mask for break detection as the HW doesn't do it*/
+#define CDNS_UART_IXR_BRK	0x00002000
+
+#define CDNS_UART_RXBS_SUPPORT BIT(1)
+/*
+ * Modem Control register:
+ * The read/write Modem Control register controls the interface with the modem
+ * or data set, or a peripheral device emulating a modem.
+ */
+#define CDNS_UART_MODEMCR_FCM	0x00000020 /* Automatic flow control mode */
+#define CDNS_UART_MODEMCR_RTS	0x00000002 /* Request to send output control */
+#define CDNS_UART_MODEMCR_DTR	0x00000001 /* Data Terminal Ready */
+
+/*
+ * Modem Status register:
+ * The read/write Modem Status register reports the interface with the modem
+ * or data set, or a peripheral device emulating a modem.
+ */
+#define CDNS_UART_MODEMSR_DCD	BIT(7) /* Data Carrier Detect */
+#define CDNS_UART_MODEMSR_RI	BIT(6) /* Ting Indicator */
+#define CDNS_UART_MODEMSR_DSR	BIT(5) /* Data Set Ready */
+#define CDNS_UART_MODEMSR_CTS	BIT(4) /* Clear To Send */
+
+/*
+ * Channel Status Register:
+ * The channel status register (CSR) is provided to enable the control logic
+ * to monitor the status of bits in the channel interrupt status register,
+ * even if these are masked out by the interrupt mask register.
+ */
+#define CDNS_UART_SR_RXEMPTY	0x00000002 /* RX FIFO empty */
+#define CDNS_UART_SR_TXEMPTY	0x00000008 /* TX FIFO empty */
+#define CDNS_UART_SR_TXFULL	0x00000010 /* TX FIFO full */
+#define CDNS_UART_SR_RXTRIG	0x00000001 /* Rx Trigger */
+#define CDNS_UART_SR_TACTIVE	0x00000800 /* TX state machine active */
+
+/* baud dividers min/max values */
+#define CDNS_UART_BDIV_MIN	4
+#define CDNS_UART_BDIV_MAX	255
+#define CDNS_UART_CD_MAX	65535
+#define UART_AUTOSUSPEND_TIMEOUT	3000
+
+/**
+ * struct cdns_uart - device data
+ * @port:		Pointer to the UART port
+ * @uartclk:		Reference clock
+ * @pclk:		APB clock
+ * @cdns_uart_driver:	Pointer to UART driver
+ * @baud:		Current baud rate
+ * @clk_rate_change_nb:	Notifier block for clock changes
+ * @quirks:		Flags for RXBS support.
+ * @cts_override:	Modem control state override
+ */
+struct cdns_uart {
+	struct uart_port	*port;
+	struct clk		*uartclk;
+	struct clk		*pclk;
+	struct uart_driver	*cdns_uart_driver;
+	unsigned int		baud;
+	struct notifier_block	clk_rate_change_nb;
+	u32			quirks;
+	bool cts_override;
+};
+struct cdns_platform_data {
+	u32 quirks;
+};
+#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
+		clk_rate_change_nb)
+
+/**
+ * cdns_uart_handle_rx - Handle the received bytes along with Rx errors.
+ * @dev_id: Id of the UART port
+ * @isrstatus: The interrupt status register value as read
+ * Return: None
+ */
+static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+	struct cdns_uart *cdns_uart = port->private_data;
+	unsigned int data;
+	unsigned int rxbs_status = 0;
+	unsigned int status_mask;
+	unsigned int framerrprocessed = 0;
+	char status = TTY_NORMAL;
+	bool is_rxbs_support;
+
+	is_rxbs_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
+
+	while ((readl(port->membase + CDNS_UART_SR) &
+		CDNS_UART_SR_RXEMPTY) != CDNS_UART_SR_RXEMPTY) {
+		if (is_rxbs_support)
+			rxbs_status = readl(port->membase + CDNS_UART_RXBS);
+		data = readl(port->membase + CDNS_UART_FIFO);
+		port->icount.rx++;
+		/*
+		 * There is no hardware break detection in Zynq, so we interpret
+		 * framing error with all-zeros data as a break sequence.
+		 * Most of the time, there's another non-zero byte at the
+		 * end of the sequence.
+		 */
+		if (!is_rxbs_support && (isrstatus & CDNS_UART_IXR_FRAMING)) {
+			if (!data) {
+				port->read_status_mask |= CDNS_UART_IXR_BRK;
+				framerrprocessed = 1;
+				continue;
+			}
+		}
+		if (is_rxbs_support && (rxbs_status & CDNS_UART_RXBS_BRK)) {
+			port->icount.brk++;
+			status = TTY_BREAK;
+			if (uart_handle_break(port))
+				continue;
+		}
+
+		isrstatus &= port->read_status_mask;
+		isrstatus &= ~port->ignore_status_mask;
+		status_mask = port->read_status_mask;
+		status_mask &= ~port->ignore_status_mask;
+
+		if (data &&
+		    (port->read_status_mask & CDNS_UART_IXR_BRK)) {
+			port->read_status_mask &= ~CDNS_UART_IXR_BRK;
+			port->icount.brk++;
+			if (uart_handle_break(port))
+				continue;
+		}
+
+		if (uart_handle_sysrq_char(port, data))
+			continue;
+
+		if (is_rxbs_support) {
+			if ((rxbs_status & CDNS_UART_RXBS_PARITY)
+			    && (status_mask & CDNS_UART_IXR_PARITY)) {
+				port->icount.parity++;
+				status = TTY_PARITY;
+			}
+			if ((rxbs_status & CDNS_UART_RXBS_FRAMING)
+			    && (status_mask & CDNS_UART_IXR_PARITY)) {
+				port->icount.frame++;
+				status = TTY_FRAME;
+			}
+		} else {
+			if (isrstatus & CDNS_UART_IXR_PARITY) {
+				port->icount.parity++;
+				status = TTY_PARITY;
+			}
+			if ((isrstatus & CDNS_UART_IXR_FRAMING) &&
+			    !framerrprocessed) {
+				port->icount.frame++;
+				status = TTY_FRAME;
+			}
+		}
+		if (isrstatus & CDNS_UART_IXR_OVERRUN) {
+			port->icount.overrun++;
+			tty_insert_flip_char(&port->state->port, 0,
+					     TTY_OVERRUN);
+		}
+		tty_insert_flip_char(&port->state->port, data, status);
+		isrstatus = 0;
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+/**
+ * cdns_uart_handle_tx - Handle the bytes to be Txed.
+ * @dev_id: Id of the UART port
+ * Return: None
+ */
+static void cdns_uart_handle_tx(void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int numbytes;
+
+	if (uart_circ_empty(xmit)) {
+		writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR);
+		return;
+	}
+
+	numbytes = port->fifosize;
+	while (numbytes && !uart_circ_empty(xmit) &&
+	       !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) {
+
+		writel(xmit->buf[xmit->tail], port->membase + CDNS_UART_FIFO);
+		uart_xmit_advance(port, 1);
+		numbytes--;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+/**
+ * cdns_uart_isr - Interrupt handler
+ * @irq: Irq number
+ * @dev_id: Id of the port
+ *
+ * Return: IRQHANDLED
+ */
+static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
+{
+	struct uart_port *port = (struct uart_port *)dev_id;
+	unsigned int isrstatus;
+
+	spin_lock(&port->lock);
+
+	/* Read the interrupt status register to determine which
+	 * interrupt(s) is/are active and clear them.
+	 */
+	isrstatus = readl(port->membase + CDNS_UART_ISR);
+	writel(isrstatus, port->membase + CDNS_UART_ISR);
+
+	if (isrstatus & CDNS_UART_IXR_TXEMPTY) {
+		cdns_uart_handle_tx(dev_id);
+		isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
+	}
+
+	isrstatus &= port->read_status_mask;
+	isrstatus &= ~port->ignore_status_mask;
+	/*
+	 * Skip RX processing if RX is disabled as RXEMPTY will never be set
+	 * as read bytes will not be removed from the FIFO.
+	 */
+	if (isrstatus & CDNS_UART_IXR_RXMASK &&
+	    !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS))
+		cdns_uart_handle_rx(dev_id, isrstatus);
+
+	spin_unlock(&port->lock);
+	return IRQ_HANDLED;
+}
+
+/**
+ * cdns_uart_calc_baud_divs - Calculate baud rate divisors
+ * @clk: UART module input clock
+ * @baud: Desired baud rate
+ * @rbdiv: BDIV value (return value)
+ * @rcd: CD value (return value)
+ * @div8: Value for clk_sel bit in mod (return value)
+ * Return: baud rate, requested baud when possible, or actual baud when there
+ *	was too much error, zero if no valid divisors are found.
+ *
+ * Formula to obtain baud rate is
+ *	baud_tx/rx rate = clk/CD * (BDIV + 1)
+ *	input_clk = (Uart User Defined Clock or Apb Clock)
+ *		depends on UCLKEN in MR Reg
+ *	clk = input_clk or input_clk/8;
+ *		depends on CLKS in MR reg
+ *	CD and BDIV depends on values in
+ *			baud rate generate register
+ *			baud rate clock divisor register
+ */
+static unsigned int cdns_uart_calc_baud_divs(unsigned int clk,
+		unsigned int baud, u32 *rbdiv, u32 *rcd, int *div8)
+{
+	u32 cd, bdiv;
+	unsigned int calc_baud;
+	unsigned int bestbaud = 0;
+	unsigned int bauderror;
+	unsigned int besterror = ~0;
+
+	if (baud < clk / ((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX)) {
+		*div8 = 1;
+		clk /= 8;
+	} else {
+		*div8 = 0;
+	}
+
+	for (bdiv = CDNS_UART_BDIV_MIN; bdiv <= CDNS_UART_BDIV_MAX; bdiv++) {
+		cd = DIV_ROUND_CLOSEST(clk, baud * (bdiv + 1));
+		if (cd < 1 || cd > CDNS_UART_CD_MAX)
+			continue;
+
+		calc_baud = clk / (cd * (bdiv + 1));
+
+		if (baud > calc_baud)
+			bauderror = baud - calc_baud;
+		else
+			bauderror = calc_baud - baud;
+
+		if (besterror > bauderror) {
+			*rbdiv = bdiv;
+			*rcd = cd;
+			bestbaud = calc_baud;
+			besterror = bauderror;
+		}
+	}
+	/* use the values when percent error is acceptable */
+	if (((besterror * 100) / baud) < 3)
+		bestbaud = baud;
+
+	return bestbaud;
+}
+
+/**
+ * cdns_uart_set_baud_rate - Calculate and set the baud rate
+ * @port: Handle to the uart port structure
+ * @baud: Baud rate to set
+ * Return: baud rate, requested baud when possible, or actual baud when there
+ *	   was too much error, zero if no valid divisors are found.
+ */
+static unsigned int cdns_uart_set_baud_rate(struct uart_port *port,
+		unsigned int baud)
+{
+	unsigned int calc_baud;
+	u32 cd = 0, bdiv = 0;
+	u32 mreg;
+	int div8;
+	struct cdns_uart *cdns_uart = port->private_data;
+
+	calc_baud = cdns_uart_calc_baud_divs(port->uartclk, baud, &bdiv, &cd,
+			&div8);
+
+	/* Write new divisors to hardware */
+	mreg = readl(port->membase + CDNS_UART_MR);
+	if (div8)
+		mreg |= CDNS_UART_MR_CLKSEL;
+	else
+		mreg &= ~CDNS_UART_MR_CLKSEL;
+	writel(mreg, port->membase + CDNS_UART_MR);
+	writel(cd, port->membase + CDNS_UART_BAUDGEN);
+	writel(bdiv, port->membase + CDNS_UART_BAUDDIV);
+	cdns_uart->baud = baud;
+
+	return calc_baud;
+}
+
+#ifdef CONFIG_COMMON_CLK
+/**
+ * cdns_uart_clk_notifier_cb - Clock notifier callback
+ * @nb:		Notifier block
+ * @event:	Notify event
+ * @data:	Notifier data
+ * Return:	NOTIFY_OK or NOTIFY_DONE on success, NOTIFY_BAD on error.
+ */
+static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
+		unsigned long event, void *data)
+{
+	u32 ctrl_reg;
+	struct uart_port *port;
+	int locked = 0;
+	struct clk_notifier_data *ndata = data;
+	struct cdns_uart *cdns_uart = to_cdns_uart(nb);
+	unsigned long flags;
+
+	port = cdns_uart->port;
+	if (port->suspended)
+		return NOTIFY_OK;
+
+	switch (event) {
+	case PRE_RATE_CHANGE:
+	{
+		u32 bdiv, cd;
+		int div8;
+
+		/*
+		 * Find out if current baud-rate can be achieved with new clock
+		 * frequency.
+		 */
+		if (!cdns_uart_calc_baud_divs(ndata->new_rate, cdns_uart->baud,
+					&bdiv, &cd, &div8)) {
+			dev_warn(port->dev, "clock rate change rejected\n");
+			return NOTIFY_BAD;
+		}
+
+		spin_lock_irqsave(&cdns_uart->port->lock, flags);
+
+		/* Disable the TX and RX to set baud rate */
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
+		writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+		spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
+
+		return NOTIFY_OK;
+	}
+	case POST_RATE_CHANGE:
+		/*
+		 * Set clk dividers to generate correct baud with new clock
+		 * frequency.
+		 */
+
+		spin_lock_irqsave(&cdns_uart->port->lock, flags);
+
+		locked = 1;
+		port->uartclk = ndata->new_rate;
+
+		cdns_uart->baud = cdns_uart_set_baud_rate(cdns_uart->port,
+				cdns_uart->baud);
+		fallthrough;
+	case ABORT_RATE_CHANGE:
+		if (!locked)
+			spin_lock_irqsave(&cdns_uart->port->lock, flags);
+
+		/* Set TX/RX Reset */
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
+		writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+		while (readl(port->membase + CDNS_UART_CR) &
+				(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
+			cpu_relax();
+
+		/*
+		 * Clear the RX disable and TX disable bits and then set the TX
+		 * enable bit and RX enable bit to enable the transmitter and
+		 * receiver.
+		 */
+		writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
+		ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
+		writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+		spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
+
+		return NOTIFY_OK;
+	default:
+		return NOTIFY_DONE;
+	}
+}
+#endif
+
+/**
+ * cdns_uart_start_tx -  Start transmitting bytes
+ * @port: Handle to the uart port structure
+ */
+static void cdns_uart_start_tx(struct uart_port *port)
+{
+	unsigned int status;
+
+	if (uart_tx_stopped(port))
+		return;
+
+	/*
+	 * Set the TX enable bit and clear the TX disable bit to enable the
+	 * transmitter.
+	 */
+	status = readl(port->membase + CDNS_UART_CR);
+	status &= ~CDNS_UART_CR_TX_DIS;
+	status |= CDNS_UART_CR_TX_EN;
+	writel(status, port->membase + CDNS_UART_CR);
+
+	if (uart_circ_empty(&port->state->xmit))
+		return;
+
+	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
+
+	cdns_uart_handle_tx(port);
+
+	/* Enable the TX Empty interrupt */
+	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);
+}
+
+/**
+ * cdns_uart_stop_tx - Stop TX
+ * @port: Handle to the uart port structure
+ */
+static void cdns_uart_stop_tx(struct uart_port *port)
+{
+	unsigned int regval;
+
+	regval = readl(port->membase + CDNS_UART_CR);
+	regval |= CDNS_UART_CR_TX_DIS;
+	/* Disable the transmitter */
+	writel(regval, port->membase + CDNS_UART_CR);
+}
+
+/**
+ * cdns_uart_stop_rx - Stop RX
+ * @port: Handle to the uart port structure
+ */
+static void cdns_uart_stop_rx(struct uart_port *port)
+{
+	unsigned int regval;
+
+	/* Disable RX IRQs */
+	writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IDR);
+
+	/* Disable the receiver */
+	regval = readl(port->membase + CDNS_UART_CR);
+	regval |= CDNS_UART_CR_RX_DIS;
+	writel(regval, port->membase + CDNS_UART_CR);
+}
+
+/**
+ * cdns_uart_tx_empty -  Check whether TX is empty
+ * @port: Handle to the uart port structure
+ *
+ * Return: TIOCSER_TEMT on success, 0 otherwise
+ */
+static unsigned int cdns_uart_tx_empty(struct uart_port *port)
+{
+	unsigned int status;
+
+	status = readl(port->membase + CDNS_UART_SR) &
+		       (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE);
+	return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0;
+}
+
+/**
+ * cdns_uart_break_ctl - Based on the input ctl we have to start or stop
+ *			transmitting char breaks
+ * @port: Handle to the uart port structure
+ * @ctl: Value based on which start or stop decision is taken
+ */
+static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	unsigned int status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	status = readl(port->membase + CDNS_UART_CR);
+
+	if (ctl == -1)
+		writel(CDNS_UART_CR_STARTBRK | status,
+				port->membase + CDNS_UART_CR);
+	else {
+		if ((status & CDNS_UART_CR_STOPBRK) == 0)
+			writel(CDNS_UART_CR_STOPBRK | status,
+					port->membase + CDNS_UART_CR);
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/**
+ * cdns_uart_set_termios - termios operations, handling data length, parity,
+ *				stop bits, flow control, baud rate
+ * @port: Handle to the uart port structure
+ * @termios: Handle to the input termios structure
+ * @old: Values of the previously saved termios structure
+ */
+static void cdns_uart_set_termios(struct uart_port *port,
+				  struct ktermios *termios,
+				  const struct ktermios *old)
+{
+	u32 cval = 0;
+	unsigned int baud, minbaud, maxbaud;
+	unsigned long flags;
+	unsigned int ctrl_reg, mode_reg;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable the TX and RX to set baud rate */
+	ctrl_reg = readl(port->membase + CDNS_UART_CR);
+	ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
+	writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+	/*
+	 * Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk
+	 * min and max baud should be calculated here based on port->uartclk.
+	 * this way we get a valid baud and can safely call set_baud()
+	 */
+	minbaud = port->uartclk /
+			((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX * 8);
+	maxbaud = port->uartclk / (CDNS_UART_BDIV_MIN + 1);
+	baud = uart_get_baud_rate(port, termios, old, minbaud, maxbaud);
+	baud = cdns_uart_set_baud_rate(port, baud);
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+	/* Update the per-port timeout. */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* Set TX/RX Reset */
+	ctrl_reg = readl(port->membase + CDNS_UART_CR);
+	ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
+	writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+	while (readl(port->membase + CDNS_UART_CR) &
+		(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
+		cpu_relax();
+
+	/*
+	 * Clear the RX disable and TX disable bits and then set the TX enable
+	 * bit and RX enable bit to enable the transmitter and receiver.
+	 */
+	ctrl_reg = readl(port->membase + CDNS_UART_CR);
+	ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
+	ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
+	writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+	writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
+
+	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
+			CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
+	port->ignore_status_mask = 0;
+
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= CDNS_UART_IXR_PARITY |
+		CDNS_UART_IXR_FRAMING;
+
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= CDNS_UART_IXR_PARITY |
+			CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
+
+	/* ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= CDNS_UART_IXR_RXTRIG |
+			CDNS_UART_IXR_TOUT | CDNS_UART_IXR_PARITY |
+			CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
+
+	mode_reg = readl(port->membase + CDNS_UART_MR);
+
+	/* Handling Data Size */
+	switch (termios->c_cflag & CSIZE) {
+	case CS6:
+		cval |= CDNS_UART_MR_CHARLEN_6_BIT;
+		break;
+	case CS7:
+		cval |= CDNS_UART_MR_CHARLEN_7_BIT;
+		break;
+	default:
+	case CS8:
+		cval |= CDNS_UART_MR_CHARLEN_8_BIT;
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+		break;
+	}
+
+	/* Handling Parity and Stop Bits length */
+	if (termios->c_cflag & CSTOPB)
+		cval |= CDNS_UART_MR_STOPMODE_2_BIT; /* 2 STOP bits */
+	else
+		cval |= CDNS_UART_MR_STOPMODE_1_BIT; /* 1 STOP bit */
+
+	if (termios->c_cflag & PARENB) {
+		/* Mark or Space parity */
+		if (termios->c_cflag & CMSPAR) {
+			if (termios->c_cflag & PARODD)
+				cval |= CDNS_UART_MR_PARITY_MARK;
+			else
+				cval |= CDNS_UART_MR_PARITY_SPACE;
+		} else {
+			if (termios->c_cflag & PARODD)
+				cval |= CDNS_UART_MR_PARITY_ODD;
+			else
+				cval |= CDNS_UART_MR_PARITY_EVEN;
+		}
+	} else {
+		cval |= CDNS_UART_MR_PARITY_NONE;
+	}
+	cval |= mode_reg & 1;
+	writel(cval, port->membase + CDNS_UART_MR);
+
+	cval = readl(port->membase + CDNS_UART_MODEMCR);
+	if (termios->c_cflag & CRTSCTS)
+		cval |= CDNS_UART_MODEMCR_FCM;
+	else
+		cval &= ~CDNS_UART_MODEMCR_FCM;
+	writel(cval, port->membase + CDNS_UART_MODEMCR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/**
+ * cdns_uart_startup - Called when an application opens a cdns_uart port
+ * @port: Handle to the uart port structure
+ *
+ * Return: 0 on success, negative errno otherwise
+ */
+static int cdns_uart_startup(struct uart_port *port)
+{
+	struct cdns_uart *cdns_uart = port->private_data;
+	bool is_brk_support;
+	int ret;
+	unsigned long flags;
+	unsigned int status = 0;
+
+	is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable the TX and RX */
+	writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
+			port->membase + CDNS_UART_CR);
+
+	/* Set the Control Register with TX/RX Enable, TX/RX Reset,
+	 * no break chars.
+	 */
+	writel(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST,
+			port->membase + CDNS_UART_CR);
+
+	while (readl(port->membase + CDNS_UART_CR) &
+		(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
+		cpu_relax();
+
+	/*
+	 * Clear the RX disable bit and then set the RX enable bit to enable
+	 * the receiver.
+	 */
+	status = readl(port->membase + CDNS_UART_CR);
+	status &= ~CDNS_UART_CR_RX_DIS;
+	status |= CDNS_UART_CR_RX_EN;
+	writel(status, port->membase + CDNS_UART_CR);
+
+	/* Set the Mode Register with normal mode,8 data bits,1 stop bit,
+	 * no parity.
+	 */
+	writel(CDNS_UART_MR_CHMODE_NORM | CDNS_UART_MR_STOPMODE_1_BIT
+		| CDNS_UART_MR_PARITY_NONE | CDNS_UART_MR_CHARLEN_8_BIT,
+		port->membase + CDNS_UART_MR);
+
+	/*
+	 * Set the RX FIFO Trigger level to use most of the FIFO, but it
+	 * can be tuned with a module parameter
+	 */
+	writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
+
+	/*
+	 * Receive Timeout register is enabled but it
+	 * can be tuned with a module parameter
+	 */
+	writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
+
+	/* Clear out any pending interrupts before enabling them */
+	writel(readl(port->membase + CDNS_UART_ISR),
+			port->membase + CDNS_UART_ISR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	ret = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, port);
+	if (ret) {
+		dev_err(port->dev, "request_irq '%d' failed with %d\n",
+			port->irq, ret);
+		return ret;
+	}
+
+	/* Set the Interrupt Registers with desired interrupts */
+	if (is_brk_support)
+		writel(CDNS_UART_RX_IRQS | CDNS_UART_IXR_BRK,
+					port->membase + CDNS_UART_IER);
+	else
+		writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER);
+
+	return 0;
+}
+
+/**
+ * cdns_uart_shutdown - Called when an application closes a cdns_uart port
+ * @port: Handle to the uart port structure
+ */
+static void cdns_uart_shutdown(struct uart_port *port)
+{
+	int status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable interrupts */
+	status = readl(port->membase + CDNS_UART_IMR);
+	writel(status, port->membase + CDNS_UART_IDR);
+	writel(0xffffffff, port->membase + CDNS_UART_ISR);
+
+	/* Disable the TX and RX */
+	writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
+			port->membase + CDNS_UART_CR);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+/**
+ * cdns_uart_type - Set UART type to cdns_uart port
+ * @port: Handle to the uart port structure
+ *
+ * Return: string on success, NULL otherwise
+ */
+static const char *cdns_uart_type(struct uart_port *port)
+{
+	return port->type == PORT_XUARTPS ? CDNS_UART_NAME : NULL;
+}
+
+/**
+ * cdns_uart_verify_port - Verify the port params
+ * @port: Handle to the uart port structure
+ * @ser: Handle to the structure whose members are compared
+ *
+ * Return: 0 on success, negative errno otherwise.
+ */
+static int cdns_uart_verify_port(struct uart_port *port,
+					struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)
+		return -EINVAL;
+	if (port->irq != ser->irq)
+		return -EINVAL;
+	if (ser->io_type != UPIO_MEM)
+		return -EINVAL;
+	if (port->iobase != ser->port)
+		return -EINVAL;
+	if (ser->hub6 != 0)
+		return -EINVAL;
+	return 0;
+}
+
+/**
+ * cdns_uart_request_port - Claim the memory region attached to cdns_uart port,
+ *				called when the driver adds a cdns_uart port via
+ *				uart_add_one_port()
+ * @port: Handle to the uart port structure
+ *
+ * Return: 0 on success, negative errno otherwise.
+ */
+static int cdns_uart_request_port(struct uart_port *port)
+{
+	if (!request_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE,
+					 CDNS_UART_NAME)) {
+		return -ENOMEM;
+	}
+
+	port->membase = ioremap(port->mapbase, CDNS_UART_REGISTER_SPACE);
+	if (!port->membase) {
+		dev_err(port->dev, "Unable to map registers\n");
+		release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+/**
+ * cdns_uart_release_port - Release UART port
+ * @port: Handle to the uart port structure
+ *
+ * Release the memory region attached to a cdns_uart port. Called when the
+ * driver removes a cdns_uart port via uart_remove_one_port().
+ */
+static void cdns_uart_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);
+	iounmap(port->membase);
+	port->membase = NULL;
+}
+
+/**
+ * cdns_uart_config_port - Configure UART port
+ * @port: Handle to the uart port structure
+ * @flags: If any
+ */
+static void cdns_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE && cdns_uart_request_port(port) == 0)
+		port->type = PORT_XUARTPS;
+}
+
+/**
+ * cdns_uart_get_mctrl - Get the modem control state
+ * @port: Handle to the uart port structure
+ *
+ * Return: the modem control state
+ */
+static unsigned int cdns_uart_get_mctrl(struct uart_port *port)
+{
+	u32 val;
+	unsigned int mctrl = 0;
+	struct cdns_uart *cdns_uart_data = port->private_data;
+
+	if (cdns_uart_data->cts_override)
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	val = readl(port->membase + CDNS_UART_MODEMSR);
+	if (val & CDNS_UART_MODEMSR_CTS)
+		mctrl |= TIOCM_CTS;
+	if (val & CDNS_UART_MODEMSR_DSR)
+		mctrl |= TIOCM_DSR;
+	if (val & CDNS_UART_MODEMSR_RI)
+		mctrl |= TIOCM_RNG;
+	if (val & CDNS_UART_MODEMSR_DCD)
+		mctrl |= TIOCM_CAR;
+
+	return mctrl;
+}
+
+static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 val;
+	u32 mode_reg;
+	struct cdns_uart *cdns_uart_data = port->private_data;
+
+	if (cdns_uart_data->cts_override)
+		return;
+
+	val = readl(port->membase + CDNS_UART_MODEMCR);
+	mode_reg = readl(port->membase + CDNS_UART_MR);
+
+	val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR);
+	mode_reg &= ~CDNS_UART_MR_CHMODE_MASK;
+
+	if (mctrl & TIOCM_RTS)
+		val |= CDNS_UART_MODEMCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		val |= CDNS_UART_MODEMCR_DTR;
+	if (mctrl & TIOCM_LOOP)
+		mode_reg |= CDNS_UART_MR_CHMODE_L_LOOP;
+	else
+		mode_reg |= CDNS_UART_MR_CHMODE_NORM;
+
+	writel(val, port->membase + CDNS_UART_MODEMCR);
+	writel(mode_reg, port->membase + CDNS_UART_MR);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int cdns_uart_poll_get_char(struct uart_port *port)
+{
+	int c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Check if FIFO is empty */
+	if (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_RXEMPTY)
+		c = NO_POLL_CHAR;
+	else /* Read a character */
+		c = (unsigned char) readl(port->membase + CDNS_UART_FIFO);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return c;
+}
+
+static void cdns_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Wait until FIFO is empty */
+	while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
+		cpu_relax();
+
+	/* Write a character */
+	writel(c, port->membase + CDNS_UART_FIFO);
+
+	/* Wait until FIFO is empty */
+	while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
+		cpu_relax();
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+#endif
+
+static void cdns_uart_pm(struct uart_port *port, unsigned int state,
+		   unsigned int oldstate)
+{
+	switch (state) {
+	case UART_PM_STATE_OFF:
+		pm_runtime_mark_last_busy(port->dev);
+		pm_runtime_put_autosuspend(port->dev);
+		break;
+	default:
+		pm_runtime_get_sync(port->dev);
+		break;
+	}
+}
+
+static const struct uart_ops cdns_uart_ops = {
+	.set_mctrl	= cdns_uart_set_mctrl,
+	.get_mctrl	= cdns_uart_get_mctrl,
+	.start_tx	= cdns_uart_start_tx,
+	.stop_tx	= cdns_uart_stop_tx,
+	.stop_rx	= cdns_uart_stop_rx,
+	.tx_empty	= cdns_uart_tx_empty,
+	.break_ctl	= cdns_uart_break_ctl,
+	.set_termios	= cdns_uart_set_termios,
+	.startup	= cdns_uart_startup,
+	.shutdown	= cdns_uart_shutdown,
+	.pm		= cdns_uart_pm,
+	.type		= cdns_uart_type,
+	.verify_port	= cdns_uart_verify_port,
+	.request_port	= cdns_uart_request_port,
+	.release_port	= cdns_uart_release_port,
+	.config_port	= cdns_uart_config_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= cdns_uart_poll_get_char,
+	.poll_put_char	= cdns_uart_poll_put_char,
+#endif
+};
+
+static struct uart_driver cdns_uart_uart_driver;
+
+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+/**
+ * cdns_uart_console_putchar - write the character to the FIFO buffer
+ * @port: Handle to the uart port structure
+ * @ch: Character to be written
+ */
+static void cdns_uart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	unsigned int ctrl_reg;
+	unsigned long timeout;
+
+	timeout = jiffies + msecs_to_jiffies(1000);
+	while (1) {
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		if (!(ctrl_reg & CDNS_UART_CR_TX_DIS))
+			break;
+		if (time_after(jiffies, timeout)) {
+			dev_warn(port->dev,
+				 "timeout waiting for Enable\n");
+			return;
+		}
+		cpu_relax();
+	}
+
+	timeout = jiffies + msecs_to_jiffies(1000);
+	while (1) {
+		ctrl_reg = readl(port->membase + CDNS_UART_SR);
+
+		if (!(ctrl_reg & CDNS_UART_SR_TXFULL))
+			break;
+		if (time_after(jiffies, timeout)) {
+			dev_warn(port->dev,
+				 "timeout waiting for TX fifo\n");
+			return;
+		}
+		cpu_relax();
+	}
+	writel(ch, port->membase + CDNS_UART_FIFO);
+}
+
+static void cdns_early_write(struct console *con, const char *s,
+				    unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, cdns_uart_console_putchar);
+}
+
+static int __init cdns_early_console_setup(struct earlycon_device *device,
+					   const char *opt)
+{
+	struct uart_port *port = &device->port;
+
+	if (!port->membase)
+		return -ENODEV;
+
+	/* initialise control register */
+	writel(CDNS_UART_CR_TX_EN|CDNS_UART_CR_TXRST|CDNS_UART_CR_RXRST,
+	       port->membase + CDNS_UART_CR);
+
+	/* only set baud if specified on command line - otherwise
+	 * assume it has been initialized by a boot loader.
+	 */
+	if (port->uartclk && device->baud) {
+		u32 cd = 0, bdiv = 0;
+		u32 mr;
+		int div8;
+
+		cdns_uart_calc_baud_divs(port->uartclk, device->baud,
+					 &bdiv, &cd, &div8);
+		mr = CDNS_UART_MR_PARITY_NONE;
+		if (div8)
+			mr |= CDNS_UART_MR_CLKSEL;
+
+		writel(mr,   port->membase + CDNS_UART_MR);
+		writel(cd,   port->membase + CDNS_UART_BAUDGEN);
+		writel(bdiv, port->membase + CDNS_UART_BAUDDIV);
+	}
+
+	device->con->write = cdns_early_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(cdns, "xlnx,xuartps", cdns_early_console_setup);
+OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p8", cdns_early_console_setup);
+OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p12", cdns_early_console_setup);
+OF_EARLYCON_DECLARE(cdns, "xlnx,zynqmp-uart", cdns_early_console_setup);
+
+
+/* Static pointer to console port */
+static struct uart_port *console_port;
+
+/**
+ * cdns_uart_console_write - perform write operation
+ * @co: Console handle
+ * @s: Pointer to character array
+ * @count: No of characters
+ */
+static void cdns_uart_console_write(struct console *co, const char *s,
+				unsigned int count)
+{
+	struct uart_port *port = console_port;
+	unsigned long flags;
+	unsigned int imr, ctrl;
+	int locked = 1;
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/* save and disable interrupt */
+	imr = readl(port->membase + CDNS_UART_IMR);
+	writel(imr, port->membase + CDNS_UART_IDR);
+
+	/*
+	 * Make sure that the tx part is enabled. Set the TX enable bit and
+	 * clear the TX disable bit to enable the transmitter.
+	 */
+	ctrl = readl(port->membase + CDNS_UART_CR);
+	ctrl &= ~CDNS_UART_CR_TX_DIS;
+	ctrl |= CDNS_UART_CR_TX_EN;
+	writel(ctrl, port->membase + CDNS_UART_CR);
+
+	uart_console_write(port, s, count, cdns_uart_console_putchar);
+	while (cdns_uart_tx_empty(port) != TIOCSER_TEMT)
+		cpu_relax();
+
+	/* restore interrupt state */
+	writel(imr, port->membase + CDNS_UART_IER);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/**
+ * cdns_uart_console_setup - Initialize the uart to default config
+ * @co: Console handle
+ * @options: Initial settings of uart
+ *
+ * Return: 0 on success, negative errno otherwise.
+ */
+static int cdns_uart_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port = console_port;
+
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	unsigned long time_out;
+
+	if (!port->membase) {
+		pr_debug("console on " CDNS_UART_TTY_NAME "%i not present\n",
+			 co->index);
+		return -ENODEV;
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	/* Wait for tx_empty before setting up the console */
+	time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT);
+
+	while (time_before(jiffies, time_out) &&
+	       cdns_uart_tx_empty(port) != TIOCSER_TEMT)
+		cpu_relax();
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console cdns_uart_console = {
+	.name	= CDNS_UART_TTY_NAME,
+	.write	= cdns_uart_console_write,
+	.device	= uart_console_device,
+	.setup	= cdns_uart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
+	.data	= &cdns_uart_uart_driver,
+};
+#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * cdns_uart_suspend - suspend event
+ * @device: Pointer to the device structure
+ *
+ * Return: 0
+ */
+static int cdns_uart_suspend(struct device *device)
+{
+	struct uart_port *port = dev_get_drvdata(device);
+	struct cdns_uart *cdns_uart = port->private_data;
+	int may_wake;
+
+	may_wake = device_may_wakeup(device);
+
+	if (console_suspend_enabled && uart_console(port) && may_wake) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&port->lock, flags);
+		/* Empty the receive FIFO 1st before making changes */
+		while (!(readl(port->membase + CDNS_UART_SR) &
+					CDNS_UART_SR_RXEMPTY))
+			readl(port->membase + CDNS_UART_FIFO);
+		/* set RX trigger level to 1 */
+		writel(1, port->membase + CDNS_UART_RXWM);
+		/* disable RX timeout interrups */
+		writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IDR);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+
+	/*
+	 * Call the API provided in serial_core.c file which handles
+	 * the suspend.
+	 */
+	return uart_suspend_port(cdns_uart->cdns_uart_driver, port);
+}
+
+/**
+ * cdns_uart_resume - Resume after a previous suspend
+ * @device: Pointer to the device structure
+ *
+ * Return: 0
+ */
+static int cdns_uart_resume(struct device *device)
+{
+	struct uart_port *port = dev_get_drvdata(device);
+	struct cdns_uart *cdns_uart = port->private_data;
+	unsigned long flags;
+	u32 ctrl_reg;
+	int may_wake;
+	int ret;
+
+	may_wake = device_may_wakeup(device);
+
+	if (console_suspend_enabled && uart_console(port) && !may_wake) {
+		ret = clk_enable(cdns_uart->pclk);
+		if (ret)
+			return ret;
+
+		ret = clk_enable(cdns_uart->uartclk);
+		if (ret) {
+			clk_disable(cdns_uart->pclk);
+			return ret;
+		}
+
+		spin_lock_irqsave(&port->lock, flags);
+
+		/* Set TX/RX Reset */
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
+		writel(ctrl_reg, port->membase + CDNS_UART_CR);
+		while (readl(port->membase + CDNS_UART_CR) &
+				(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
+			cpu_relax();
+
+		/* restore rx timeout value */
+		writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
+		/* Enable Tx/Rx */
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
+		ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
+		writel(ctrl_reg, port->membase + CDNS_UART_CR);
+
+		clk_disable(cdns_uart->uartclk);
+		clk_disable(cdns_uart->pclk);
+		spin_unlock_irqrestore(&port->lock, flags);
+	} else {
+		spin_lock_irqsave(&port->lock, flags);
+		/* restore original rx trigger level */
+		writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
+		/* enable RX timeout interrupt */
+		writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER);
+		spin_unlock_irqrestore(&port->lock, flags);
+	}
+
+	return uart_resume_port(cdns_uart->cdns_uart_driver, port);
+}
+#endif /* ! CONFIG_PM_SLEEP */
+static int __maybe_unused cdns_runtime_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct cdns_uart *cdns_uart = port->private_data;
+
+	clk_disable(cdns_uart->uartclk);
+	clk_disable(cdns_uart->pclk);
+	return 0;
+};
+
+static int __maybe_unused cdns_runtime_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct cdns_uart *cdns_uart = port->private_data;
+	int ret;
+
+	ret = clk_enable(cdns_uart->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(cdns_uart->uartclk);
+	if (ret) {
+		clk_disable(cdns_uart->pclk);
+		return ret;
+	}
+	return 0;
+};
+
+static const struct dev_pm_ops cdns_uart_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(cdns_uart_suspend, cdns_uart_resume)
+	SET_RUNTIME_PM_OPS(cdns_runtime_suspend,
+			   cdns_runtime_resume, NULL)
+};
+
+static const struct cdns_platform_data zynqmp_uart_def = {
+				.quirks = CDNS_UART_RXBS_SUPPORT, };
+
+/* Match table for of_platform binding */
+static const struct of_device_id cdns_uart_of_match[] = {
+	{ .compatible = "xlnx,xuartps", },
+	{ .compatible = "cdns,uart-r1p8", },
+	{ .compatible = "cdns,uart-r1p12", .data = &zynqmp_uart_def },
+	{ .compatible = "xlnx,zynqmp-uart", .data = &zynqmp_uart_def },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cdns_uart_of_match);
+
+/* Temporary variable for storing number of instances */
+static int instances;
+
+/**
+ * cdns_uart_probe - Platform driver probe
+ * @pdev: Pointer to the platform device structure
+ *
+ * Return: 0 on success, negative errno otherwise
+ */
+static int cdns_uart_probe(struct platform_device *pdev)
+{
+	int rc, id, irq;
+	struct uart_port *port;
+	struct resource *res;
+	struct cdns_uart *cdns_uart_data;
+	const struct of_device_id *match;
+
+	cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data),
+			GFP_KERNEL);
+	if (!cdns_uart_data)
+		return -ENOMEM;
+	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	/* Look for a serialN alias */
+	id = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (id < 0)
+		id = 0;
+
+	if (id >= CDNS_UART_NR_PORTS) {
+		dev_err(&pdev->dev, "Cannot get uart_port structure\n");
+		return -ENODEV;
+	}
+
+	if (!cdns_uart_uart_driver.state) {
+		cdns_uart_uart_driver.owner = THIS_MODULE;
+		cdns_uart_uart_driver.driver_name = CDNS_UART_NAME;
+		cdns_uart_uart_driver.dev_name = CDNS_UART_TTY_NAME;
+		cdns_uart_uart_driver.major = CDNS_UART_MAJOR;
+		cdns_uart_uart_driver.minor = CDNS_UART_MINOR;
+		cdns_uart_uart_driver.nr = CDNS_UART_NR_PORTS;
+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+		cdns_uart_uart_driver.cons = &cdns_uart_console;
+#endif
+
+		rc = uart_register_driver(&cdns_uart_uart_driver);
+		if (rc < 0) {
+			dev_err(&pdev->dev, "Failed to register driver\n");
+			return rc;
+		}
+	}
+
+	cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver;
+
+	match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);
+	if (match && match->data) {
+		const struct cdns_platform_data *data = match->data;
+
+		cdns_uart_data->quirks = data->quirks;
+	}
+
+	cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "pclk");
+	if (PTR_ERR(cdns_uart_data->pclk) == -EPROBE_DEFER) {
+		rc = PTR_ERR(cdns_uart_data->pclk);
+		goto err_out_unregister_driver;
+	}
+
+	if (IS_ERR(cdns_uart_data->pclk)) {
+		cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "aper_clk");
+		if (IS_ERR(cdns_uart_data->pclk)) {
+			rc = PTR_ERR(cdns_uart_data->pclk);
+			goto err_out_unregister_driver;
+		}
+		dev_err(&pdev->dev, "clock name 'aper_clk' is deprecated.\n");
+	}
+
+	cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
+	if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER) {
+		rc = PTR_ERR(cdns_uart_data->uartclk);
+		goto err_out_unregister_driver;
+	}
+
+	if (IS_ERR(cdns_uart_data->uartclk)) {
+		cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "ref_clk");
+		if (IS_ERR(cdns_uart_data->uartclk)) {
+			rc = PTR_ERR(cdns_uart_data->uartclk);
+			goto err_out_unregister_driver;
+		}
+		dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
+	}
+
+	rc = clk_prepare_enable(cdns_uart_data->pclk);
+	if (rc) {
+		dev_err(&pdev->dev, "Unable to enable pclk clock.\n");
+		goto err_out_unregister_driver;
+	}
+	rc = clk_prepare_enable(cdns_uart_data->uartclk);
+	if (rc) {
+		dev_err(&pdev->dev, "Unable to enable device clock.\n");
+		goto err_out_clk_dis_pclk;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		rc = -ENODEV;
+		goto err_out_clk_disable;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		rc = irq;
+		goto err_out_clk_disable;
+	}
+
+#ifdef CONFIG_COMMON_CLK
+	cdns_uart_data->clk_rate_change_nb.notifier_call =
+			cdns_uart_clk_notifier_cb;
+	if (clk_notifier_register(cdns_uart_data->uartclk,
+				&cdns_uart_data->clk_rate_change_nb))
+		dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
+#endif
+
+	/* At this point, we've got an empty uart_port struct, initialize it */
+	spin_lock_init(&port->lock);
+	port->type	= PORT_UNKNOWN;
+	port->iotype	= UPIO_MEM32;
+	port->flags	= UPF_BOOT_AUTOCONF;
+	port->ops	= &cdns_uart_ops;
+	port->fifosize	= CDNS_UART_FIFO_SIZE;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_XILINX_PS_UART_CONSOLE);
+	port->line	= id;
+
+	/*
+	 * Register the port.
+	 * This function also registers this device with the tty layer
+	 * and triggers invocation of the config_port() entry point.
+	 */
+	port->mapbase = res->start;
+	port->irq = irq;
+	port->dev = &pdev->dev;
+	port->uartclk = clk_get_rate(cdns_uart_data->uartclk);
+	port->private_data = cdns_uart_data;
+	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
+			CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
+	cdns_uart_data->port = port;
+	platform_set_drvdata(pdev, port);
+
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	device_init_wakeup(port->dev, true);
+
+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+	/*
+	 * If console hasn't been found yet try to assign this port
+	 * because it is required to be assigned for console setup function.
+	 * If register_console() don't assign value, then console_port pointer
+	 * is cleanup.
+	 */
+	if (!console_port) {
+		cdns_uart_console.index = id;
+		console_port = port;
+	}
+#endif
+
+	rc = uart_add_one_port(&cdns_uart_uart_driver, port);
+	if (rc) {
+		dev_err(&pdev->dev,
+			"uart_add_one_port() failed; err=%i\n", rc);
+		goto err_out_pm_disable;
+	}
+
+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+	/* This is not port which is used for console that's why clean it up */
+	if (console_port == port &&
+	    !console_is_registered(cdns_uart_uart_driver.cons)) {
+		console_port = NULL;
+		cdns_uart_console.index = -1;
+	}
+#endif
+
+	cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
+							     "cts-override");
+
+	instances++;
+
+	return 0;
+
+err_out_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+#ifdef CONFIG_COMMON_CLK
+	clk_notifier_unregister(cdns_uart_data->uartclk,
+			&cdns_uart_data->clk_rate_change_nb);
+#endif
+err_out_clk_disable:
+	clk_disable_unprepare(cdns_uart_data->uartclk);
+err_out_clk_dis_pclk:
+	clk_disable_unprepare(cdns_uart_data->pclk);
+err_out_unregister_driver:
+	if (!instances)
+		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
+	return rc;
+}
+
+/**
+ * cdns_uart_remove - called when the platform driver is unregistered
+ * @pdev: Pointer to the platform device structure
+ *
+ * Return: 0 on success, negative errno otherwise
+ */
+static int cdns_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+	struct cdns_uart *cdns_uart_data = port->private_data;
+
+	/* Remove the cdns_uart port from the serial core */
+#ifdef CONFIG_COMMON_CLK
+	clk_notifier_unregister(cdns_uart_data->uartclk,
+			&cdns_uart_data->clk_rate_change_nb);
+#endif
+	uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);
+	port->mapbase = 0;
+	clk_disable_unprepare(cdns_uart_data->uartclk);
+	clk_disable_unprepare(cdns_uart_data->pclk);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	device_init_wakeup(&pdev->dev, false);
+
+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+	if (console_port == port)
+		console_port = NULL;
+#endif
+
+	if (!--instances)
+		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
+	return 0;
+}
+
+static struct platform_driver cdns_uart_platform_driver = {
+	.probe   = cdns_uart_probe,
+	.remove  = cdns_uart_remove,
+	.driver  = {
+		.name = CDNS_UART_NAME,
+		.of_match_table = cdns_uart_of_match,
+		.pm = &cdns_uart_dev_pm_ops,
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_XILINX_PS_UART),
+		},
+};
+
+static int __init cdns_uart_init(void)
+{
+	/* Register the platform driver */
+	return platform_driver_register(&cdns_uart_platform_driver);
+}
+
+static void __exit cdns_uart_exit(void)
+{
+	/* Unregister the platform driver */
+	platform_driver_unregister(&cdns_uart_platform_driver);
+}
+
+arch_initcall(cdns_uart_init);
+module_exit(cdns_uart_exit);
+
+MODULE_DESCRIPTION("Driver for Cadence UART");
+MODULE_AUTHOR("Xilinx Inc.");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/zs.c b/drivers/tty/serial/zs.c
new file mode 100644
index 000000000..65ca4da6e
--- /dev/null
+++ b/drivers/tty/serial/zs.c
@@ -0,0 +1,1307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * zs.c: Serial port driver for IOASIC DECstations.
+ *
+ * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras.
+ * Derived from drivers/macintosh/macserial.c by Harald Koerfgen.
+ *
+ * DECstation changes
+ * Copyright (C) 1998-2000 Harald Koerfgen
+ * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007  Maciej W. Rozycki
+ *
+ * For the rest of the code the original Copyright applies:
+ * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ *
+ *
+ * Note: for IOASIC systems the wiring is as follows:
+ *
+ * mouse/keyboard:
+ * DIN-7 MJ-4  signal        SCC
+ * 2     1     TxD       <-  A.TxD
+ * 3     4     RxD       ->  A.RxD
+ *
+ * EIA-232/EIA-423:
+ * DB-25 MMJ-6 signal        SCC
+ * 2     2     TxD       <-  B.TxD
+ * 3     5     RxD       ->  B.RxD
+ * 4           RTS       <- ~A.RTS
+ * 5           CTS       -> ~B.CTS
+ * 6     6     DSR       -> ~A.SYNC
+ * 8           CD        -> ~B.DCD
+ * 12          DSRS(DCE) -> ~A.CTS  (*)
+ * 15          TxC       ->  B.TxC
+ * 17          RxC       ->  B.RxC
+ * 20    1     DTR       <- ~A.DTR
+ * 22          RI        -> ~A.DCD
+ * 23          DSRS(DTE) <- ~B.RTS
+ *
+ * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE)
+ *     is shared with DSRS(DTE) at pin 23.
+ *
+ * As you can immediately notice the wiring of the RTS, DTR and DSR signals
+ * is a bit odd.  This makes the handling of port B unnecessarily
+ * complicated and prevents the use of some automatic modes of operation.
+ */
+
+#include <linux/bug.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irqflags.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/major.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+
+#include <linux/atomic.h>
+
+#include <asm/dec/interrupts.h>
+#include <asm/dec/ioasic_addrs.h>
+#include <asm/dec/system.h>
+
+#include "zs.h"
+
+
+MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
+MODULE_DESCRIPTION("DECstation Z85C30 serial driver");
+MODULE_LICENSE("GPL");
+
+
+static char zs_name[] __initdata = "DECstation Z85C30 serial driver version ";
+static char zs_version[] __initdata = "0.10";
+
+/*
+ * It would be nice to dynamically allocate everything that
+ * depends on ZS_NUM_SCCS, so we could support any number of
+ * Z85C30s, but for now...
+ */
+#define ZS_NUM_SCCS	2		/* Max # of ZS chips supported.  */
+#define ZS_NUM_CHAN	2		/* 2 channels per chip.  */
+#define ZS_CHAN_A	0		/* Index of the channel A.  */
+#define ZS_CHAN_B	1		/* Index of the channel B.  */
+#define ZS_CHAN_IO_SIZE 8		/* IOMEM space size.  */
+#define ZS_CHAN_IO_STRIDE 4		/* Register alignment.  */
+#define ZS_CHAN_IO_OFFSET 1		/* The SCC resides on the high byte
+					   of the 16-bit IOBUS.  */
+#define ZS_CLOCK        7372800 	/* Z85C30 PCLK input clock rate.  */
+
+#define to_zport(uport) container_of(uport, struct zs_port, port)
+
+struct zs_parms {
+	resource_size_t scc[ZS_NUM_SCCS];
+	int irq[ZS_NUM_SCCS];
+};
+
+static struct zs_scc zs_sccs[ZS_NUM_SCCS];
+
+static u8 zs_init_regs[ZS_NUM_REGS] __initdata = {
+	0,				/* write 0 */
+	PAR_SPEC,			/* write 1 */
+	0,				/* write 2 */
+	0,				/* write 3 */
+	X16CLK | SB1,			/* write 4 */
+	0,				/* write 5 */
+	0, 0, 0,			/* write 6, 7, 8 */
+	MIE | DLC | NV,			/* write 9 */
+	NRZ,				/* write 10 */
+	TCBR | RCBR,			/* write 11 */
+	0, 0,				/* BRG time constant, write 12 + 13 */
+	BRSRC | BRENABL,		/* write 14 */
+	0,				/* write 15 */
+};
+
+/*
+ * Debugging.
+ */
+#undef ZS_DEBUG_REGS
+
+
+/*
+ * Reading and writing Z85C30 registers.
+ */
+static void recovery_delay(void)
+{
+	udelay(2);
+}
+
+static u8 read_zsreg(struct zs_port *zport, int reg)
+{
+	void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET;
+	u8 retval;
+
+	if (reg != 0) {
+		writeb(reg & 0xf, control);
+		fast_iob();
+		recovery_delay();
+	}
+	retval = readb(control);
+	recovery_delay();
+	return retval;
+}
+
+static void write_zsreg(struct zs_port *zport, int reg, u8 value)
+{
+	void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET;
+
+	if (reg != 0) {
+		writeb(reg & 0xf, control);
+		fast_iob(); recovery_delay();
+	}
+	writeb(value, control);
+	fast_iob();
+	recovery_delay();
+	return;
+}
+
+static u8 read_zsdata(struct zs_port *zport)
+{
+	void __iomem *data = zport->port.membase +
+			     ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET;
+	u8 retval;
+
+	retval = readb(data);
+	recovery_delay();
+	return retval;
+}
+
+static void write_zsdata(struct zs_port *zport, u8 value)
+{
+	void __iomem *data = zport->port.membase +
+			     ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET;
+
+	writeb(value, data);
+	fast_iob();
+	recovery_delay();
+	return;
+}
+
+#ifdef ZS_DEBUG_REGS
+void zs_dump(void)
+{
+	struct zs_port *zport;
+	int i, j;
+
+	for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
+		zport = &zs_sccs[i / ZS_NUM_CHAN].zport[i % ZS_NUM_CHAN];
+
+		if (!zport->scc)
+			continue;
+
+		for (j = 0; j < 16; j++)
+			printk("W%-2d = 0x%02x\t", j, zport->regs[j]);
+		printk("\n");
+		for (j = 0; j < 16; j++)
+			printk("R%-2d = 0x%02x\t", j, read_zsreg(zport, j));
+		printk("\n\n");
+	}
+}
+#endif
+
+
+static void zs_spin_lock_cond_irq(spinlock_t *lock, int irq)
+{
+	if (irq)
+		spin_lock_irq(lock);
+	else
+		spin_lock(lock);
+}
+
+static void zs_spin_unlock_cond_irq(spinlock_t *lock, int irq)
+{
+	if (irq)
+		spin_unlock_irq(lock);
+	else
+		spin_unlock(lock);
+}
+
+static int zs_receive_drain(struct zs_port *zport)
+{
+	int loops = 10000;
+
+	while ((read_zsreg(zport, R0) & Rx_CH_AV) && --loops)
+		read_zsdata(zport);
+	return loops;
+}
+
+static int zs_transmit_drain(struct zs_port *zport, int irq)
+{
+	struct zs_scc *scc = zport->scc;
+	int loops = 10000;
+
+	while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && --loops) {
+		zs_spin_unlock_cond_irq(&scc->zlock, irq);
+		udelay(2);
+		zs_spin_lock_cond_irq(&scc->zlock, irq);
+	}
+	return loops;
+}
+
+static int zs_line_drain(struct zs_port *zport, int irq)
+{
+	struct zs_scc *scc = zport->scc;
+	int loops = 10000;
+
+	while (!(read_zsreg(zport, R1) & ALL_SNT) && --loops) {
+		zs_spin_unlock_cond_irq(&scc->zlock, irq);
+		udelay(2);
+		zs_spin_lock_cond_irq(&scc->zlock, irq);
+	}
+	return loops;
+}
+
+
+static void load_zsregs(struct zs_port *zport, u8 *regs, int irq)
+{
+	/* Let the current transmission finish.  */
+	zs_line_drain(zport, irq);
+	/* Load 'em up.  */
+	write_zsreg(zport, R3, regs[3] & ~RxENABLE);
+	write_zsreg(zport, R5, regs[5] & ~TxENAB);
+	write_zsreg(zport, R4, regs[4]);
+	write_zsreg(zport, R9, regs[9]);
+	write_zsreg(zport, R1, regs[1]);
+	write_zsreg(zport, R2, regs[2]);
+	write_zsreg(zport, R10, regs[10]);
+	write_zsreg(zport, R14, regs[14] & ~BRENABL);
+	write_zsreg(zport, R11, regs[11]);
+	write_zsreg(zport, R12, regs[12]);
+	write_zsreg(zport, R13, regs[13]);
+	write_zsreg(zport, R14, regs[14]);
+	write_zsreg(zport, R15, regs[15]);
+	if (regs[3] & RxENABLE)
+		write_zsreg(zport, R3, regs[3]);
+	if (regs[5] & TxENAB)
+		write_zsreg(zport, R5, regs[5]);
+	return;
+}
+
+
+/*
+ * Status handling routines.
+ */
+
+/*
+ * zs_tx_empty() -- get the transmitter empty status
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ * 	    is emptied.  On bus types like RS485, the transmitter must
+ * 	    release the bus after transmitting.  This must be done when
+ * 	    the transmit shift register is empty, not be done when the
+ * 	    transmit holding register is empty.  This functionality
+ * 	    allows an RS485 driver to be written in user space.
+ */
+static unsigned int zs_tx_empty(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	unsigned long flags;
+	u8 status;
+
+	spin_lock_irqsave(&scc->zlock, flags);
+	status = read_zsreg(zport, R1);
+	spin_unlock_irqrestore(&scc->zlock, flags);
+
+	return status & ALL_SNT ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int zs_raw_get_ab_mctrl(struct zs_port *zport_a,
+					struct zs_port *zport_b)
+{
+	u8 status_a, status_b;
+	unsigned int mctrl;
+
+	status_a = read_zsreg(zport_a, R0);
+	status_b = read_zsreg(zport_b, R0);
+
+	mctrl = ((status_b & CTS) ? TIOCM_CTS : 0) |
+		((status_b & DCD) ? TIOCM_CAR : 0) |
+		((status_a & DCD) ? TIOCM_RNG : 0) |
+		((status_a & SYNC_HUNT) ? TIOCM_DSR : 0);
+
+	return mctrl;
+}
+
+static unsigned int zs_raw_get_mctrl(struct zs_port *zport)
+{
+	struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A];
+
+	return zport != zport_a ? zs_raw_get_ab_mctrl(zport_a, zport) : 0;
+}
+
+static unsigned int zs_raw_xor_mctrl(struct zs_port *zport)
+{
+	struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A];
+	unsigned int mmask, mctrl, delta;
+	u8 mask_a, mask_b;
+
+	if (zport == zport_a)
+		return 0;
+
+	mask_a = zport_a->regs[15];
+	mask_b = zport->regs[15];
+
+	mmask = ((mask_b & CTSIE) ? TIOCM_CTS : 0) |
+		((mask_b & DCDIE) ? TIOCM_CAR : 0) |
+		((mask_a & DCDIE) ? TIOCM_RNG : 0) |
+		((mask_a & SYNCIE) ? TIOCM_DSR : 0);
+
+	mctrl = zport->mctrl;
+	if (mmask) {
+		mctrl &= ~mmask;
+		mctrl |= zs_raw_get_ab_mctrl(zport_a, zport) & mmask;
+	}
+
+	delta = mctrl ^ zport->mctrl;
+	if (delta)
+		zport->mctrl = mctrl;
+
+	return delta;
+}
+
+static unsigned int zs_get_mctrl(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	unsigned int mctrl;
+
+	spin_lock(&scc->zlock);
+	mctrl = zs_raw_get_mctrl(zport);
+	spin_unlock(&scc->zlock);
+
+	return mctrl;
+}
+
+static void zs_set_mctrl(struct uart_port *uport, unsigned int mctrl)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
+	u8 oldloop, newloop;
+
+	spin_lock(&scc->zlock);
+	if (zport != zport_a) {
+		if (mctrl & TIOCM_DTR)
+			zport_a->regs[5] |= DTR;
+		else
+			zport_a->regs[5] &= ~DTR;
+		if (mctrl & TIOCM_RTS)
+			zport_a->regs[5] |= RTS;
+		else
+			zport_a->regs[5] &= ~RTS;
+		write_zsreg(zport_a, R5, zport_a->regs[5]);
+	}
+
+	/* Rarely modified, so don't poke at hardware unless necessary. */
+	oldloop = zport->regs[14];
+	newloop = oldloop;
+	if (mctrl & TIOCM_LOOP)
+		newloop |= LOOPBAK;
+	else
+		newloop &= ~LOOPBAK;
+	if (newloop != oldloop) {
+		zport->regs[14] = newloop;
+		write_zsreg(zport, R14, zport->regs[14]);
+	}
+	spin_unlock(&scc->zlock);
+}
+
+static void zs_raw_stop_tx(struct zs_port *zport)
+{
+	write_zsreg(zport, R0, RES_Tx_P);
+	zport->tx_stopped = 1;
+}
+
+static void zs_stop_tx(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+
+	spin_lock(&scc->zlock);
+	zs_raw_stop_tx(zport);
+	spin_unlock(&scc->zlock);
+}
+
+static void zs_raw_transmit_chars(struct zs_port *);
+
+static void zs_start_tx(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+
+	spin_lock(&scc->zlock);
+	if (zport->tx_stopped) {
+		zs_transmit_drain(zport, 0);
+		zport->tx_stopped = 0;
+		zs_raw_transmit_chars(zport);
+	}
+	spin_unlock(&scc->zlock);
+}
+
+static void zs_stop_rx(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
+
+	spin_lock(&scc->zlock);
+	zport->regs[15] &= ~BRKIE;
+	zport->regs[1] &= ~(RxINT_MASK | TxINT_ENAB);
+	zport->regs[1] |= RxINT_DISAB;
+
+	if (zport != zport_a) {
+		/* A-side DCD tracks RI and SYNC tracks DSR.  */
+		zport_a->regs[15] &= ~(DCDIE | SYNCIE);
+		write_zsreg(zport_a, R15, zport_a->regs[15]);
+		if (!(zport_a->regs[15] & BRKIE)) {
+			zport_a->regs[1] &= ~EXT_INT_ENAB;
+			write_zsreg(zport_a, R1, zport_a->regs[1]);
+		}
+
+		/* This-side DCD tracks DCD and CTS tracks CTS.  */
+		zport->regs[15] &= ~(DCDIE | CTSIE);
+		zport->regs[1] &= ~EXT_INT_ENAB;
+	} else {
+		/* DCD tracks RI and SYNC tracks DSR for the B side.  */
+		if (!(zport->regs[15] & (DCDIE | SYNCIE)))
+			zport->regs[1] &= ~EXT_INT_ENAB;
+	}
+
+	write_zsreg(zport, R15, zport->regs[15]);
+	write_zsreg(zport, R1, zport->regs[1]);
+	spin_unlock(&scc->zlock);
+}
+
+static void zs_enable_ms(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
+
+	if (zport == zport_a)
+		return;
+
+	spin_lock(&scc->zlock);
+
+	/* Clear Ext interrupts if not being handled already.  */
+	if (!(zport_a->regs[1] & EXT_INT_ENAB))
+		write_zsreg(zport_a, R0, RES_EXT_INT);
+
+	/* A-side DCD tracks RI and SYNC tracks DSR.  */
+	zport_a->regs[1] |= EXT_INT_ENAB;
+	zport_a->regs[15] |= DCDIE | SYNCIE;
+
+	/* This-side DCD tracks DCD and CTS tracks CTS.  */
+	zport->regs[15] |= DCDIE | CTSIE;
+
+	zs_raw_xor_mctrl(zport);
+
+	write_zsreg(zport_a, R1, zport_a->regs[1]);
+	write_zsreg(zport_a, R15, zport_a->regs[15]);
+	write_zsreg(zport, R15, zport->regs[15]);
+	spin_unlock(&scc->zlock);
+}
+
+static void zs_break_ctl(struct uart_port *uport, int break_state)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&scc->zlock, flags);
+	if (break_state == -1)
+		zport->regs[5] |= SND_BRK;
+	else
+		zport->regs[5] &= ~SND_BRK;
+	write_zsreg(zport, R5, zport->regs[5]);
+	spin_unlock_irqrestore(&scc->zlock, flags);
+}
+
+
+/*
+ * Interrupt handling routines.
+ */
+#define Rx_BRK 0x0100			/* BREAK event software flag.  */
+#define Rx_SYS 0x0200			/* SysRq event software flag.  */
+
+static void zs_receive_chars(struct zs_port *zport)
+{
+	struct uart_port *uport = &zport->port;
+	struct zs_scc *scc = zport->scc;
+	struct uart_icount *icount;
+	unsigned int avail, status;
+	int count;
+	u8 ch, flag;
+
+	for (count = 16; count; count--) {
+		spin_lock(&scc->zlock);
+		avail = read_zsreg(zport, R0) & Rx_CH_AV;
+		spin_unlock(&scc->zlock);
+		if (!avail)
+			break;
+
+		spin_lock(&scc->zlock);
+		status = read_zsreg(zport, R1) & (Rx_OVR | FRM_ERR | PAR_ERR);
+		ch = read_zsdata(zport);
+		spin_unlock(&scc->zlock);
+
+		flag = TTY_NORMAL;
+
+		icount = &uport->icount;
+		icount->rx++;
+
+		/* Handle the null char got when BREAK is removed.  */
+		if (!ch)
+			status |= zport->tty_break;
+		if (unlikely(status &
+			     (Rx_OVR | FRM_ERR | PAR_ERR | Rx_SYS | Rx_BRK))) {
+			zport->tty_break = 0;
+
+			/* Reset the error indication.  */
+			if (status & (Rx_OVR | FRM_ERR | PAR_ERR)) {
+				spin_lock(&scc->zlock);
+				write_zsreg(zport, R0, ERR_RES);
+				spin_unlock(&scc->zlock);
+			}
+
+			if (status & (Rx_SYS | Rx_BRK)) {
+				icount->brk++;
+				/* SysRq discards the null char.  */
+				if (status & Rx_SYS)
+					continue;
+			} else if (status & FRM_ERR)
+				icount->frame++;
+			else if (status & PAR_ERR)
+				icount->parity++;
+			if (status & Rx_OVR)
+				icount->overrun++;
+
+			status &= uport->read_status_mask;
+			if (status & Rx_BRK)
+				flag = TTY_BREAK;
+			else if (status & FRM_ERR)
+				flag = TTY_FRAME;
+			else if (status & PAR_ERR)
+				flag = TTY_PARITY;
+		}
+
+		if (uart_handle_sysrq_char(uport, ch))
+			continue;
+
+		uart_insert_char(uport, status, Rx_OVR, ch, flag);
+	}
+
+	tty_flip_buffer_push(&uport->state->port);
+}
+
+static void zs_raw_transmit_chars(struct zs_port *zport)
+{
+	struct circ_buf *xmit = &zport->port.state->xmit;
+
+	/* XON/XOFF chars.  */
+	if (zport->port.x_char) {
+		write_zsdata(zport, zport->port.x_char);
+		zport->port.icount.tx++;
+		zport->port.x_char = 0;
+		return;
+	}
+
+	/* If nothing to do or stopped or hardware stopped.  */
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&zport->port)) {
+		zs_raw_stop_tx(zport);
+		return;
+	}
+
+	/* Send char.  */
+	write_zsdata(zport, xmit->buf[xmit->tail]);
+	uart_xmit_advance(&zport->port, 1);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&zport->port);
+
+	/* Are we are done?  */
+	if (uart_circ_empty(xmit))
+		zs_raw_stop_tx(zport);
+}
+
+static void zs_transmit_chars(struct zs_port *zport)
+{
+	struct zs_scc *scc = zport->scc;
+
+	spin_lock(&scc->zlock);
+	zs_raw_transmit_chars(zport);
+	spin_unlock(&scc->zlock);
+}
+
+static void zs_status_handle(struct zs_port *zport, struct zs_port *zport_a)
+{
+	struct uart_port *uport = &zport->port;
+	struct zs_scc *scc = zport->scc;
+	unsigned int delta;
+	u8 status, brk;
+
+	spin_lock(&scc->zlock);
+
+	/* Get status from Read Register 0.  */
+	status = read_zsreg(zport, R0);
+
+	if (zport->regs[15] & BRKIE) {
+		brk = status & BRK_ABRT;
+		if (brk && !zport->brk) {
+			spin_unlock(&scc->zlock);
+			if (uart_handle_break(uport))
+				zport->tty_break = Rx_SYS;
+			else
+				zport->tty_break = Rx_BRK;
+			spin_lock(&scc->zlock);
+		}
+		zport->brk = brk;
+	}
+
+	if (zport != zport_a) {
+		delta = zs_raw_xor_mctrl(zport);
+		spin_unlock(&scc->zlock);
+
+		if (delta & TIOCM_CTS)
+			uart_handle_cts_change(uport,
+					       zport->mctrl & TIOCM_CTS);
+		if (delta & TIOCM_CAR)
+			uart_handle_dcd_change(uport,
+					       zport->mctrl & TIOCM_CAR);
+		if (delta & TIOCM_RNG)
+			uport->icount.dsr++;
+		if (delta & TIOCM_DSR)
+			uport->icount.rng++;
+
+		if (delta)
+			wake_up_interruptible(&uport->state->port.delta_msr_wait);
+
+		spin_lock(&scc->zlock);
+	}
+
+	/* Clear the status condition...  */
+	write_zsreg(zport, R0, RES_EXT_INT);
+
+	spin_unlock(&scc->zlock);
+}
+
+/*
+ * This is the Z85C30 driver's generic interrupt routine.
+ */
+static irqreturn_t zs_interrupt(int irq, void *dev_id)
+{
+	struct zs_scc *scc = dev_id;
+	struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
+	struct zs_port *zport_b = &scc->zport[ZS_CHAN_B];
+	irqreturn_t status = IRQ_NONE;
+	u8 zs_intreg;
+	int count;
+
+	/*
+	 * NOTE: The read register 3, which holds the irq status,
+	 *       does so for both channels on each chip.  Although
+	 *       the status value itself must be read from the A
+	 *       channel and is only valid when read from channel A.
+	 *       Yes... broken hardware...
+	 */
+	for (count = 16; count; count--) {
+		spin_lock(&scc->zlock);
+		zs_intreg = read_zsreg(zport_a, R3);
+		spin_unlock(&scc->zlock);
+		if (!zs_intreg)
+			break;
+
+		/*
+		 * We do not like losing characters, so we prioritise
+		 * interrupt sources a little bit differently than
+		 * the SCC would, was it allowed to.
+		 */
+		if (zs_intreg & CHBRxIP)
+			zs_receive_chars(zport_b);
+		if (zs_intreg & CHARxIP)
+			zs_receive_chars(zport_a);
+		if (zs_intreg & CHBEXT)
+			zs_status_handle(zport_b, zport_a);
+		if (zs_intreg & CHAEXT)
+			zs_status_handle(zport_a, zport_a);
+		if (zs_intreg & CHBTxIP)
+			zs_transmit_chars(zport_b);
+		if (zs_intreg & CHATxIP)
+			zs_transmit_chars(zport_a);
+
+		status = IRQ_HANDLED;
+	}
+
+	return status;
+}
+
+
+/*
+ * Finally, routines used to initialize the serial port.
+ */
+static int zs_startup(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	unsigned long flags;
+	int irq_guard;
+	int ret;
+
+	irq_guard = atomic_add_return(1, &scc->irq_guard);
+	if (irq_guard == 1) {
+		ret = request_irq(zport->port.irq, zs_interrupt,
+				  IRQF_SHARED, "scc", scc);
+		if (ret) {
+			atomic_add(-1, &scc->irq_guard);
+			printk(KERN_ERR "zs: can't get irq %d\n",
+			       zport->port.irq);
+			return ret;
+		}
+	}
+
+	spin_lock_irqsave(&scc->zlock, flags);
+
+	/* Clear the receive FIFO.  */
+	zs_receive_drain(zport);
+
+	/* Clear the interrupt registers.  */
+	write_zsreg(zport, R0, ERR_RES);
+	write_zsreg(zport, R0, RES_Tx_P);
+	/* But Ext only if not being handled already.  */
+	if (!(zport->regs[1] & EXT_INT_ENAB))
+		write_zsreg(zport, R0, RES_EXT_INT);
+
+	/* Finally, enable sequencing and interrupts.  */
+	zport->regs[1] &= ~RxINT_MASK;
+	zport->regs[1] |= RxINT_ALL | TxINT_ENAB | EXT_INT_ENAB;
+	zport->regs[3] |= RxENABLE;
+	zport->regs[15] |= BRKIE;
+	write_zsreg(zport, R1, zport->regs[1]);
+	write_zsreg(zport, R3, zport->regs[3]);
+	write_zsreg(zport, R5, zport->regs[5]);
+	write_zsreg(zport, R15, zport->regs[15]);
+
+	/* Record the current state of RR0.  */
+	zport->mctrl = zs_raw_get_mctrl(zport);
+	zport->brk = read_zsreg(zport, R0) & BRK_ABRT;
+
+	zport->tx_stopped = 1;
+
+	spin_unlock_irqrestore(&scc->zlock, flags);
+
+	return 0;
+}
+
+static void zs_shutdown(struct uart_port *uport)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	unsigned long flags;
+	int irq_guard;
+
+	spin_lock_irqsave(&scc->zlock, flags);
+
+	zport->regs[3] &= ~RxENABLE;
+	write_zsreg(zport, R5, zport->regs[5]);
+	write_zsreg(zport, R3, zport->regs[3]);
+
+	spin_unlock_irqrestore(&scc->zlock, flags);
+
+	irq_guard = atomic_add_return(-1, &scc->irq_guard);
+	if (!irq_guard)
+		free_irq(zport->port.irq, scc);
+}
+
+
+static void zs_reset(struct zs_port *zport)
+{
+	struct zs_scc *scc = zport->scc;
+	int irq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&scc->zlock, flags);
+	irq = !irqs_disabled_flags(flags);
+	if (!scc->initialised) {
+		/* Reset the pointer first, just in case...  */
+		read_zsreg(zport, R0);
+		/* And let the current transmission finish.  */
+		zs_line_drain(zport, irq);
+		write_zsreg(zport, R9, FHWRES);
+		udelay(10);
+		write_zsreg(zport, R9, 0);
+		scc->initialised = 1;
+	}
+	load_zsregs(zport, zport->regs, irq);
+	spin_unlock_irqrestore(&scc->zlock, flags);
+}
+
+static void zs_set_termios(struct uart_port *uport, struct ktermios *termios,
+			   const struct ktermios *old_termios)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
+	int irq;
+	unsigned int baud, brg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&scc->zlock, flags);
+	irq = !irqs_disabled_flags(flags);
+
+	/* Byte size.  */
+	zport->regs[3] &= ~RxNBITS_MASK;
+	zport->regs[5] &= ~TxNBITS_MASK;
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		zport->regs[3] |= Rx5;
+		zport->regs[5] |= Tx5;
+		break;
+	case CS6:
+		zport->regs[3] |= Rx6;
+		zport->regs[5] |= Tx6;
+		break;
+	case CS7:
+		zport->regs[3] |= Rx7;
+		zport->regs[5] |= Tx7;
+		break;
+	case CS8:
+	default:
+		zport->regs[3] |= Rx8;
+		zport->regs[5] |= Tx8;
+		break;
+	}
+
+	/* Parity and stop bits.  */
+	zport->regs[4] &= ~(XCLK_MASK | SB_MASK | PAR_ENA | PAR_EVEN);
+	if (termios->c_cflag & CSTOPB)
+		zport->regs[4] |= SB2;
+	else
+		zport->regs[4] |= SB1;
+	if (termios->c_cflag & PARENB)
+		zport->regs[4] |= PAR_ENA;
+	if (!(termios->c_cflag & PARODD))
+		zport->regs[4] |= PAR_EVEN;
+	switch (zport->clk_mode) {
+	case 64:
+		zport->regs[4] |= X64CLK;
+		break;
+	case 32:
+		zport->regs[4] |= X32CLK;
+		break;
+	case 16:
+		zport->regs[4] |= X16CLK;
+		break;
+	case 1:
+		zport->regs[4] |= X1CLK;
+		break;
+	default:
+		BUG();
+	}
+
+	baud = uart_get_baud_rate(uport, termios, old_termios, 0,
+				  uport->uartclk / zport->clk_mode / 4);
+
+	brg = ZS_BPS_TO_BRG(baud, uport->uartclk / zport->clk_mode);
+	zport->regs[12] = brg & 0xff;
+	zport->regs[13] = (brg >> 8) & 0xff;
+
+	uart_update_timeout(uport, termios->c_cflag, baud);
+
+	uport->read_status_mask = Rx_OVR;
+	if (termios->c_iflag & INPCK)
+		uport->read_status_mask |= FRM_ERR | PAR_ERR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		uport->read_status_mask |= Rx_BRK;
+
+	uport->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		uport->ignore_status_mask |= FRM_ERR | PAR_ERR;
+	if (termios->c_iflag & IGNBRK) {
+		uport->ignore_status_mask |= Rx_BRK;
+		if (termios->c_iflag & IGNPAR)
+			uport->ignore_status_mask |= Rx_OVR;
+	}
+
+	if (termios->c_cflag & CREAD)
+		zport->regs[3] |= RxENABLE;
+	else
+		zport->regs[3] &= ~RxENABLE;
+
+	if (zport != zport_a) {
+		if (!(termios->c_cflag & CLOCAL)) {
+			zport->regs[15] |= DCDIE;
+		} else
+			zport->regs[15] &= ~DCDIE;
+		if (termios->c_cflag & CRTSCTS) {
+			zport->regs[15] |= CTSIE;
+		} else
+			zport->regs[15] &= ~CTSIE;
+		zs_raw_xor_mctrl(zport);
+	}
+
+	/* Load up the new values.  */
+	load_zsregs(zport, zport->regs, irq);
+
+	spin_unlock_irqrestore(&scc->zlock, flags);
+}
+
+/*
+ * Hack alert!
+ * Required solely so that the initial PROM-based console
+ * works undisturbed in parallel with this one.
+ */
+static void zs_pm(struct uart_port *uport, unsigned int state,
+		  unsigned int oldstate)
+{
+	struct zs_port *zport = to_zport(uport);
+
+	if (state < 3)
+		zport->regs[5] |= TxENAB;
+	else
+		zport->regs[5] &= ~TxENAB;
+	write_zsreg(zport, R5, zport->regs[5]);
+}
+
+
+static const char *zs_type(struct uart_port *uport)
+{
+	return "Z85C30 SCC";
+}
+
+static void zs_release_port(struct uart_port *uport)
+{
+	iounmap(uport->membase);
+	uport->membase = NULL;
+	release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
+}
+
+static int zs_map_port(struct uart_port *uport)
+{
+	if (!uport->membase)
+		uport->membase = ioremap(uport->mapbase,
+						 ZS_CHAN_IO_SIZE);
+	if (!uport->membase) {
+		printk(KERN_ERR "zs: Cannot map MMIO\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static int zs_request_port(struct uart_port *uport)
+{
+	int ret;
+
+	if (!request_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE, "scc")) {
+		printk(KERN_ERR "zs: Unable to reserve MMIO resource\n");
+		return -EBUSY;
+	}
+	ret = zs_map_port(uport);
+	if (ret) {
+		release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
+		return ret;
+	}
+	return 0;
+}
+
+static void zs_config_port(struct uart_port *uport, int flags)
+{
+	struct zs_port *zport = to_zport(uport);
+
+	if (flags & UART_CONFIG_TYPE) {
+		if (zs_request_port(uport))
+			return;
+
+		uport->type = PORT_ZS;
+
+		zs_reset(zport);
+	}
+}
+
+static int zs_verify_port(struct uart_port *uport, struct serial_struct *ser)
+{
+	struct zs_port *zport = to_zport(uport);
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_ZS)
+		ret = -EINVAL;
+	if (ser->irq != uport->irq)
+		ret = -EINVAL;
+	if (ser->baud_base != uport->uartclk / zport->clk_mode / 4)
+		ret = -EINVAL;
+	return ret;
+}
+
+
+static const struct uart_ops zs_ops = {
+	.tx_empty	= zs_tx_empty,
+	.set_mctrl	= zs_set_mctrl,
+	.get_mctrl	= zs_get_mctrl,
+	.stop_tx	= zs_stop_tx,
+	.start_tx	= zs_start_tx,
+	.stop_rx	= zs_stop_rx,
+	.enable_ms	= zs_enable_ms,
+	.break_ctl	= zs_break_ctl,
+	.startup	= zs_startup,
+	.shutdown	= zs_shutdown,
+	.set_termios	= zs_set_termios,
+	.pm		= zs_pm,
+	.type		= zs_type,
+	.release_port	= zs_release_port,
+	.request_port	= zs_request_port,
+	.config_port	= zs_config_port,
+	.verify_port	= zs_verify_port,
+};
+
+/*
+ * Initialize Z85C30 port structures.
+ */
+static int __init zs_probe_sccs(void)
+{
+	static int probed;
+	struct zs_parms zs_parms;
+	int chip, side, irq;
+	int n_chips = 0;
+	int i;
+
+	if (probed)
+		return 0;
+
+	irq = dec_interrupt[DEC_IRQ_SCC0];
+	if (irq >= 0) {
+		zs_parms.scc[n_chips] = IOASIC_SCC0;
+		zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC0];
+		n_chips++;
+	}
+	irq = dec_interrupt[DEC_IRQ_SCC1];
+	if (irq >= 0) {
+		zs_parms.scc[n_chips] = IOASIC_SCC1;
+		zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC1];
+		n_chips++;
+	}
+	if (!n_chips)
+		return -ENXIO;
+
+	probed = 1;
+
+	for (chip = 0; chip < n_chips; chip++) {
+		spin_lock_init(&zs_sccs[chip].zlock);
+		for (side = 0; side < ZS_NUM_CHAN; side++) {
+			struct zs_port *zport = &zs_sccs[chip].zport[side];
+			struct uart_port *uport = &zport->port;
+
+			zport->scc	= &zs_sccs[chip];
+			zport->clk_mode	= 16;
+
+			uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ZS_CONSOLE);
+			uport->irq	= zs_parms.irq[chip];
+			uport->uartclk	= ZS_CLOCK;
+			uport->fifosize	= 1;
+			uport->iotype	= UPIO_MEM;
+			uport->flags	= UPF_BOOT_AUTOCONF;
+			uport->ops	= &zs_ops;
+			uport->line	= chip * ZS_NUM_CHAN + side;
+			uport->mapbase	= dec_kn_slot_base +
+					  zs_parms.scc[chip] +
+					  (side ^ ZS_CHAN_B) * ZS_CHAN_IO_SIZE;
+
+			for (i = 0; i < ZS_NUM_REGS; i++)
+				zport->regs[i] = zs_init_regs[i];
+		}
+	}
+
+	return 0;
+}
+
+
+#ifdef CONFIG_SERIAL_ZS_CONSOLE
+static void zs_console_putchar(struct uart_port *uport, unsigned char ch)
+{
+	struct zs_port *zport = to_zport(uport);
+	struct zs_scc *scc = zport->scc;
+	int irq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&scc->zlock, flags);
+	irq = !irqs_disabled_flags(flags);
+	if (zs_transmit_drain(zport, irq))
+		write_zsdata(zport, ch);
+	spin_unlock_irqrestore(&scc->zlock, flags);
+}
+
+/*
+ * Print a string to the serial port trying not to disturb
+ * any possible real use of the port...
+ */
+static void zs_console_write(struct console *co, const char *s,
+			     unsigned int count)
+{
+	int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
+	struct zs_port *zport = &zs_sccs[chip].zport[side];
+	struct zs_scc *scc = zport->scc;
+	unsigned long flags;
+	u8 txint, txenb;
+	int irq;
+
+	/* Disable transmit interrupts and enable the transmitter. */
+	spin_lock_irqsave(&scc->zlock, flags);
+	txint = zport->regs[1];
+	txenb = zport->regs[5];
+	if (txint & TxINT_ENAB) {
+		zport->regs[1] = txint & ~TxINT_ENAB;
+		write_zsreg(zport, R1, zport->regs[1]);
+	}
+	if (!(txenb & TxENAB)) {
+		zport->regs[5] = txenb | TxENAB;
+		write_zsreg(zport, R5, zport->regs[5]);
+	}
+	spin_unlock_irqrestore(&scc->zlock, flags);
+
+	uart_console_write(&zport->port, s, count, zs_console_putchar);
+
+	/* Restore transmit interrupts and the transmitter enable. */
+	spin_lock_irqsave(&scc->zlock, flags);
+	irq = !irqs_disabled_flags(flags);
+	zs_line_drain(zport, irq);
+	if (!(txenb & TxENAB)) {
+		zport->regs[5] &= ~TxENAB;
+		write_zsreg(zport, R5, zport->regs[5]);
+	}
+	if (txint & TxINT_ENAB) {
+		zport->regs[1] |= TxINT_ENAB;
+		write_zsreg(zport, R1, zport->regs[1]);
+
+		/* Resume any transmission as the TxIP bit won't be set.  */
+		if (!zport->tx_stopped)
+			zs_raw_transmit_chars(zport);
+	}
+	spin_unlock_irqrestore(&scc->zlock, flags);
+}
+
+/*
+ * Setup serial console baud/bits/parity.  We do two things here:
+ * - construct a cflag setting for the first uart_open()
+ * - initialise the serial port
+ * Return non-zero if we didn't find a serial port.
+ */
+static int __init zs_console_setup(struct console *co, char *options)
+{
+	int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
+	struct zs_port *zport = &zs_sccs[chip].zport[side];
+	struct uart_port *uport = &zport->port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	ret = zs_map_port(uport);
+	if (ret)
+		return ret;
+
+	zs_reset(zport);
+	zs_pm(uport, 0, -1);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	return uart_set_options(uport, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver zs_reg;
+static struct console zs_console = {
+	.name	= "ttyS",
+	.write	= zs_console_write,
+	.device	= uart_console_device,
+	.setup	= zs_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &zs_reg,
+};
+
+/*
+ *	Register console.
+ */
+static int __init zs_serial_console_init(void)
+{
+	int ret;
+
+	ret = zs_probe_sccs();
+	if (ret)
+		return ret;
+	register_console(&zs_console);
+
+	return 0;
+}
+
+console_initcall(zs_serial_console_init);
+
+#define SERIAL_ZS_CONSOLE	&zs_console
+#else
+#define SERIAL_ZS_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_ZS_CONSOLE */
+
+static struct uart_driver zs_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "serial",
+	.dev_name		= "ttyS",
+	.major			= TTY_MAJOR,
+	.minor			= 64,
+	.nr			= ZS_NUM_SCCS * ZS_NUM_CHAN,
+	.cons			= SERIAL_ZS_CONSOLE,
+};
+
+/* zs_init inits the driver. */
+static int __init zs_init(void)
+{
+	int i, ret;
+
+	pr_info("%s%s\n", zs_name, zs_version);
+
+	/* Find out how many Z85C30 SCCs we have.  */
+	ret = zs_probe_sccs();
+	if (ret)
+		return ret;
+
+	ret = uart_register_driver(&zs_reg);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
+		struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
+		struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
+		struct uart_port *uport = &zport->port;
+
+		if (zport->scc)
+			uart_add_one_port(&zs_reg, uport);
+	}
+
+	return 0;
+}
+
+static void __exit zs_exit(void)
+{
+	int i;
+
+	for (i = ZS_NUM_SCCS * ZS_NUM_CHAN - 1; i >= 0; i--) {
+		struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
+		struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
+		struct uart_port *uport = &zport->port;
+
+		if (zport->scc)
+			uart_remove_one_port(&zs_reg, uport);
+	}
+
+	uart_unregister_driver(&zs_reg);
+}
+
+module_init(zs_init);
+module_exit(zs_exit);
diff --git a/drivers/tty/serial/zs.h b/drivers/tty/serial/zs.h
new file mode 100644
index 000000000..26ef8eafa
--- /dev/null
+++ b/drivers/tty/serial/zs.h
@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * zs.h: Definitions for the DECstation Z85C30 serial driver.
+ *
+ * Adapted from drivers/sbus/char/sunserial.h by Paul Mackerras.
+ * Adapted from drivers/macintosh/macserial.h by Harald Koerfgen.
+ *
+ * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 2004, 2005, 2007  Maciej W. Rozycki
+ */
+#ifndef _SERIAL_ZS_H
+#define _SERIAL_ZS_H
+
+#ifdef __KERNEL__
+
+#define ZS_NUM_REGS 16
+
+/*
+ * This is our internal structure for each serial port's state.
+ */
+struct zs_port {
+	struct zs_scc	*scc;			/* Containing SCC.  */
+	struct uart_port port;			/* Underlying UART.  */
+
+	int		clk_mode;		/* May be 1, 16, 32, or 64.  */
+
+	unsigned int	tty_break;		/* Set on BREAK condition.  */
+	int		tx_stopped;		/* Output is suspended.  */
+
+	unsigned int	mctrl;			/* State of modem lines.  */
+	u8		brk;			/* BREAK state from RR0.  */
+
+	u8		regs[ZS_NUM_REGS];	/* Channel write registers.  */
+};
+
+/*
+ * Per-SCC state for locking and the interrupt handler.
+ */
+struct zs_scc {
+	struct zs_port	zport[2];
+	spinlock_t	zlock;
+	atomic_t	irq_guard;
+	int		initialised;
+};
+
+#endif /* __KERNEL__ */
+
+/*
+ * Conversion routines to/from brg time constants from/to bits per second.
+ */
+#define ZS_BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
+#define ZS_BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)
+
+/*
+ * The Zilog register set.
+ */
+
+/* Write Register 0 (Command) */
+#define R0		0	/* Register selects */
+#define R1		1
+#define R2		2
+#define R3		3
+#define R4		4
+#define R5		5
+#define R6		6
+#define R7		7
+#define R8		8
+#define R9		9
+#define R10		10
+#define R11		11
+#define R12		12
+#define R13		13
+#define R14		14
+#define R15		15
+
+#define NULLCODE	0	/* Null Code */
+#define POINT_HIGH	0x8	/* Select upper half of registers */
+#define RES_EXT_INT	0x10	/* Reset Ext. Status Interrupts */
+#define SEND_ABORT	0x18	/* HDLC Abort */
+#define RES_RxINT_FC	0x20	/* Reset RxINT on First Character */
+#define RES_Tx_P	0x28	/* Reset TxINT Pending */
+#define ERR_RES		0x30	/* Error Reset */
+#define RES_H_IUS	0x38	/* Reset highest IUS */
+
+#define RES_Rx_CRC	0x40	/* Reset Rx CRC Checker */
+#define RES_Tx_CRC	0x80	/* Reset Tx CRC Checker */
+#define RES_EOM_L	0xC0	/* Reset EOM latch */
+
+/* Write Register 1 (Tx/Rx/Ext Int Enable and WAIT/DMA Commands) */
+#define EXT_INT_ENAB	0x1	/* Ext Int Enable */
+#define TxINT_ENAB	0x2	/* Tx Int Enable */
+#define PAR_SPEC	0x4	/* Parity is special condition */
+
+#define RxINT_DISAB	0	/* Rx Int Disable */
+#define RxINT_FCERR	0x8	/* Rx Int on First Character Only or Error */
+#define RxINT_ALL	0x10	/* Int on all Rx Characters or error */
+#define RxINT_ERR	0x18	/* Int on error only */
+#define RxINT_MASK	0x18
+
+#define WT_RDY_RT	0x20	/* Wait/Ready on R/T */
+#define WT_FN_RDYFN	0x40	/* Wait/FN/Ready FN */
+#define WT_RDY_ENAB	0x80	/* Wait/Ready Enable */
+
+/* Write Register 2 (Interrupt Vector) */
+
+/* Write Register 3 (Receive Parameters and Control) */
+#define RxENABLE	0x1	/* Rx Enable */
+#define SYNC_L_INH	0x2	/* Sync Character Load Inhibit */
+#define ADD_SM		0x4	/* Address Search Mode (SDLC) */
+#define RxCRC_ENAB	0x8	/* Rx CRC Enable */
+#define ENT_HM		0x10	/* Enter Hunt Mode */
+#define AUTO_ENAB	0x20	/* Auto Enables */
+#define Rx5		0x0	/* Rx 5 Bits/Character */
+#define Rx7		0x40	/* Rx 7 Bits/Character */
+#define Rx6		0x80	/* Rx 6 Bits/Character */
+#define Rx8		0xc0	/* Rx 8 Bits/Character */
+#define RxNBITS_MASK	0xc0
+
+/* Write Register 4 (Transmit/Receive Miscellaneous Parameters and Modes) */
+#define PAR_ENA		0x1	/* Parity Enable */
+#define PAR_EVEN	0x2	/* Parity Even/Odd* */
+
+#define SYNC_ENAB	0	/* Sync Modes Enable */
+#define SB1		0x4	/* 1 stop bit/char */
+#define SB15		0x8	/* 1.5 stop bits/char */
+#define SB2		0xc	/* 2 stop bits/char */
+#define SB_MASK		0xc
+
+#define MONSYNC		0	/* 8 Bit Sync character */
+#define BISYNC		0x10	/* 16 bit sync character */
+#define SDLC		0x20	/* SDLC Mode (01111110 Sync Flag) */
+#define EXTSYNC		0x30	/* External Sync Mode */
+
+#define X1CLK		0x0	/* x1 clock mode */
+#define X16CLK		0x40	/* x16 clock mode */
+#define X32CLK		0x80	/* x32 clock mode */
+#define X64CLK		0xc0	/* x64 clock mode */
+#define XCLK_MASK	0xc0
+
+/* Write Register 5 (Transmit Parameters and Controls) */
+#define TxCRC_ENAB	0x1	/* Tx CRC Enable */
+#define RTS		0x2	/* RTS */
+#define SDLC_CRC	0x4	/* SDLC/CRC-16 */
+#define TxENAB		0x8	/* Tx Enable */
+#define SND_BRK		0x10	/* Send Break */
+#define Tx5		0x0	/* Tx 5 bits (or less)/character */
+#define Tx7		0x20	/* Tx 7 bits/character */
+#define Tx6		0x40	/* Tx 6 bits/character */
+#define Tx8		0x60	/* Tx 8 bits/character */
+#define TxNBITS_MASK	0x60
+#define DTR		0x80	/* DTR */
+
+/* Write Register 6 (Sync bits 0-7/SDLC Address Field) */
+
+/* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
+
+/* Write Register 8 (Transmit Buffer) */
+
+/* Write Register 9 (Master Interrupt Control) */
+#define VIS		1	/* Vector Includes Status */
+#define NV		2	/* No Vector */
+#define DLC		4	/* Disable Lower Chain */
+#define MIE		8	/* Master Interrupt Enable */
+#define STATHI		0x10	/* Status high */
+#define SOFTACK		0x20	/* Software Interrupt Acknowledge */
+#define NORESET		0	/* No reset on write to R9 */
+#define CHRB		0x40	/* Reset channel B */
+#define CHRA		0x80	/* Reset channel A */
+#define FHWRES		0xc0	/* Force hardware reset */
+
+/* Write Register 10 (Miscellaneous Transmitter/Receiver Control Bits) */
+#define BIT6		1	/* 6 bit/8bit sync */
+#define LOOPMODE	2	/* SDLC Loop mode */
+#define ABUNDER		4	/* Abort/flag on SDLC xmit underrun */
+#define MARKIDLE	8	/* Mark/flag on idle */
+#define GAOP		0x10	/* Go active on poll */
+#define NRZ		0	/* NRZ mode */
+#define NRZI		0x20	/* NRZI mode */
+#define FM1		0x40	/* FM1 (transition = 1) */
+#define FM0		0x60	/* FM0 (transition = 0) */
+#define CRCPS		0x80	/* CRC Preset I/O */
+
+/* Write Register 11 (Clock Mode Control) */
+#define TRxCXT		0	/* TRxC = Xtal output */
+#define TRxCTC		1	/* TRxC = Transmit clock */
+#define TRxCBR		2	/* TRxC = BR Generator Output */
+#define TRxCDP		3	/* TRxC = DPLL output */
+#define TRxCOI		4	/* TRxC O/I */
+#define TCRTxCP		0	/* Transmit clock = RTxC pin */
+#define TCTRxCP		8	/* Transmit clock = TRxC pin */
+#define TCBR		0x10	/* Transmit clock = BR Generator output */
+#define TCDPLL		0x18	/* Transmit clock = DPLL output */
+#define RCRTxCP		0	/* Receive clock = RTxC pin */
+#define RCTRxCP		0x20	/* Receive clock = TRxC pin */
+#define RCBR		0x40	/* Receive clock = BR Generator output */
+#define RCDPLL		0x60	/* Receive clock = DPLL output */
+#define RTxCX		0x80	/* RTxC Xtal/No Xtal */
+
+/* Write Register 12 (Lower Byte of Baud Rate Generator Time Constant) */
+
+/* Write Register 13 (Upper Byte of Baud Rate Generator Time Constant) */
+
+/* Write Register 14 (Miscellaneous Control Bits) */
+#define BRENABL		1	/* Baud rate generator enable */
+#define BRSRC		2	/* Baud rate generator source */
+#define DTRREQ		4	/* DTR/Request function */
+#define AUTOECHO	8	/* Auto Echo */
+#define LOOPBAK		0x10	/* Local loopback */
+#define SEARCH		0x20	/* Enter search mode */
+#define RMC		0x40	/* Reset missing clock */
+#define DISDPLL		0x60	/* Disable DPLL */
+#define SSBR		0x80	/* Set DPLL source = BR generator */
+#define SSRTxC		0xa0	/* Set DPLL source = RTxC */
+#define SFMM		0xc0	/* Set FM mode */
+#define SNRZI		0xe0	/* Set NRZI mode */
+
+/* Write Register 15 (External/Status Interrupt Control) */
+#define WR7P_EN		1	/* WR7 Prime SDLC Feature Enable */
+#define ZCIE		2	/* Zero count IE */
+#define DCDIE		8	/* DCD IE */
+#define SYNCIE		0x10	/* Sync/hunt IE */
+#define CTSIE		0x20	/* CTS IE */
+#define TxUIE		0x40	/* Tx Underrun/EOM IE */
+#define BRKIE		0x80	/* Break/Abort IE */
+
+
+/* Read Register 0 (Transmit/Receive Buffer Status and External Status) */
+#define Rx_CH_AV	0x1	/* Rx Character Available */
+#define ZCOUNT		0x2	/* Zero count */
+#define Tx_BUF_EMP	0x4	/* Tx Buffer empty */
+#define DCD		0x8	/* DCD */
+#define SYNC_HUNT	0x10	/* Sync/hunt */
+#define CTS		0x20	/* CTS */
+#define TxEOM		0x40	/* Tx underrun */
+#define BRK_ABRT	0x80	/* Break/Abort */
+
+/* Read Register 1 (Special Receive Condition Status) */
+#define ALL_SNT		0x1	/* All sent */
+/* Residue Data for 8 Rx bits/char programmed */
+#define RES3		0x8	/* 0/3 */
+#define RES4		0x4	/* 0/4 */
+#define RES5		0xc	/* 0/5 */
+#define RES6		0x2	/* 0/6 */
+#define RES7		0xa	/* 0/7 */
+#define RES8		0x6	/* 0/8 */
+#define RES18		0xe	/* 1/8 */
+#define RES28		0x0	/* 2/8 */
+/* Special Rx Condition Interrupts */
+#define PAR_ERR		0x10	/* Parity Error */
+#define Rx_OVR		0x20	/* Rx Overrun Error */
+#define FRM_ERR		0x40	/* CRC/Framing Error */
+#define END_FR		0x80	/* End of Frame (SDLC) */
+
+/* Read Register 2 (Interrupt Vector (WR2) -- channel A).  */
+
+/* Read Register 2 (Modified Interrupt Vector -- channel B).  */
+
+/* Read Register 3 (Interrupt Pending Bits -- channel A only).  */
+#define CHBEXT		0x1	/* Channel B Ext/Stat IP */
+#define CHBTxIP		0x2	/* Channel B Tx IP */
+#define CHBRxIP		0x4	/* Channel B Rx IP */
+#define CHAEXT		0x8	/* Channel A Ext/Stat IP */
+#define CHATxIP		0x10	/* Channel A Tx IP */
+#define CHARxIP		0x20	/* Channel A Rx IP */
+
+/* Read Register 6 (SDLC FIFO Status and Byte Count LSB) */
+
+/* Read Register 7 (SDLC FIFO Status and Byte Count MSB) */
+
+/* Read Register 8 (Receive Data) */
+
+/* Read Register 10 (Miscellaneous Status Bits) */
+#define ONLOOP		2	/* On loop */
+#define LOOPSEND	0x10	/* Loop sending */
+#define CLK2MIS		0x40	/* Two clocks missing */
+#define CLK1MIS		0x80	/* One clock missing */
+
+/* Read Register 12 (Lower Byte of Baud Rate Generator Constant (WR12)) */
+
+/* Read Register 13 (Upper Byte of Baud Rate Generator Constant (WR13) */
+
+/* Read Register 15 (External/Status Interrupt Control (WR15)) */
+
+#endif /* _SERIAL_ZS_H */
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
new file mode 100644
index 000000000..8112d9d5a
--- /dev/null
+++ b/drivers/tty/synclink_gt.c
@@ -0,0 +1,5037 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * Device driver for Microgate SyncLink GT serial adapters.
+ *
+ * written by Paul Fulghum for Microgate Corporation
+ * paulkf@microgate.com
+ *
+ * Microgate and SyncLink are trademarks of Microgate Corporation
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * DEBUG OUTPUT DEFINITIONS
+ *
+ * uncomment lines below to enable specific types of debug output
+ *
+ * DBGINFO   information - most verbose output
+ * DBGERR    serious errors
+ * DBGBH     bottom half service routine debugging
+ * DBGISR    interrupt service routine debugging
+ * DBGDATA   output receive and transmit data
+ * DBGTBUF   output transmit DMA buffers and registers
+ * DBGRBUF   output receive DMA buffers and registers
+ */
+
+#define DBGINFO(fmt) if (debug_level >= DEBUG_LEVEL_INFO) printk fmt
+#define DBGERR(fmt) if (debug_level >= DEBUG_LEVEL_ERROR) printk fmt
+#define DBGBH(fmt) if (debug_level >= DEBUG_LEVEL_BH) printk fmt
+#define DBGISR(fmt) if (debug_level >= DEBUG_LEVEL_ISR) printk fmt
+#define DBGDATA(info, buf, size, label) if (debug_level >= DEBUG_LEVEL_DATA) trace_block((info), (buf), (size), (label))
+/*#define DBGTBUF(info) dump_tbufs(info)*/
+/*#define DBGRBUF(info) dump_rbufs(info)*/
+
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/ioctl.h>
+#include <linux/termios.h>
+#include <linux/bitops.h>
+#include <linux/workqueue.h>
+#include <linux/hdlc.h>
+#include <linux/synclink.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/dma.h>
+#include <asm/types.h>
+#include <linux/uaccess.h>
+
+#if defined(CONFIG_HDLC) || (defined(CONFIG_HDLC_MODULE) && defined(CONFIG_SYNCLINK_GT_MODULE))
+#define SYNCLINK_GENERIC_HDLC 1
+#else
+#define SYNCLINK_GENERIC_HDLC 0
+#endif
+
+/*
+ * module identification
+ */
+static const char driver_name[] = "SyncLink GT";
+static const char tty_dev_prefix[] = "ttySLG";
+MODULE_LICENSE("GPL");
+#define MAX_DEVICES 32
+
+static const struct pci_device_id pci_table[] = {
+	{ PCI_VDEVICE(MICROGATE, SYNCLINK_GT_DEVICE_ID) },
+	{ PCI_VDEVICE(MICROGATE, SYNCLINK_GT2_DEVICE_ID) },
+	{ PCI_VDEVICE(MICROGATE, SYNCLINK_GT4_DEVICE_ID) },
+	{ PCI_VDEVICE(MICROGATE, SYNCLINK_AC_DEVICE_ID) },
+	{ 0 }, /* terminate list */
+};
+MODULE_DEVICE_TABLE(pci, pci_table);
+
+static int  init_one(struct pci_dev *dev,const struct pci_device_id *ent);
+static void remove_one(struct pci_dev *dev);
+static struct pci_driver pci_driver = {
+	.name		= "synclink_gt",
+	.id_table	= pci_table,
+	.probe		= init_one,
+	.remove		= remove_one,
+};
+
+static bool pci_registered;
+
+/*
+ * module configuration and status
+ */
+static struct slgt_info *slgt_device_list;
+static int slgt_device_count;
+
+static int ttymajor;
+static int debug_level;
+static int maxframe[MAX_DEVICES];
+
+module_param(ttymajor, int, 0);
+module_param(debug_level, int, 0);
+module_param_array(maxframe, int, NULL, 0);
+
+MODULE_PARM_DESC(ttymajor, "TTY major device number override: 0=auto assigned");
+MODULE_PARM_DESC(debug_level, "Debug syslog output: 0=disabled, 1 to 5=increasing detail");
+MODULE_PARM_DESC(maxframe, "Maximum frame size used by device (4096 to 65535)");
+
+/*
+ * tty support and callbacks
+ */
+static struct tty_driver *serial_driver;
+
+static void wait_until_sent(struct tty_struct *tty, int timeout);
+static void flush_buffer(struct tty_struct *tty);
+static void tx_release(struct tty_struct *tty);
+
+/*
+ * generic HDLC support
+ */
+#define dev_to_port(D) (dev_to_hdlc(D)->priv)
+
+
+/*
+ * device specific structures, macros and functions
+ */
+
+#define SLGT_MAX_PORTS 4
+#define SLGT_REG_SIZE  256
+
+/*
+ * conditional wait facility
+ */
+struct cond_wait {
+	struct cond_wait *next;
+	wait_queue_head_t q;
+	wait_queue_entry_t wait;
+	unsigned int data;
+};
+static void flush_cond_wait(struct cond_wait **head);
+
+/*
+ * DMA buffer descriptor and access macros
+ */
+struct slgt_desc
+{
+	__le16 count;
+	__le16 status;
+	__le32 pbuf;  /* physical address of data buffer */
+	__le32 next;  /* physical address of next descriptor */
+
+	/* driver book keeping */
+	char *buf;          /* virtual  address of data buffer */
+    	unsigned int pdesc; /* physical address of this descriptor */
+	dma_addr_t buf_dma_addr;
+	unsigned short buf_count;
+};
+
+#define set_desc_buffer(a,b) (a).pbuf = cpu_to_le32((unsigned int)(b))
+#define set_desc_next(a,b) (a).next   = cpu_to_le32((unsigned int)(b))
+#define set_desc_count(a,b)(a).count  = cpu_to_le16((unsigned short)(b))
+#define set_desc_eof(a,b)  (a).status = cpu_to_le16((b) ? (le16_to_cpu((a).status) | BIT0) : (le16_to_cpu((a).status) & ~BIT0))
+#define set_desc_status(a, b) (a).status = cpu_to_le16((unsigned short)(b))
+#define desc_count(a)      (le16_to_cpu((a).count))
+#define desc_status(a)     (le16_to_cpu((a).status))
+#define desc_complete(a)   (le16_to_cpu((a).status) & BIT15)
+#define desc_eof(a)        (le16_to_cpu((a).status) & BIT2)
+#define desc_crc_error(a)  (le16_to_cpu((a).status) & BIT1)
+#define desc_abort(a)      (le16_to_cpu((a).status) & BIT0)
+#define desc_residue(a)    ((le16_to_cpu((a).status) & 0x38) >> 3)
+
+struct _input_signal_events {
+	int ri_up;
+	int ri_down;
+	int dsr_up;
+	int dsr_down;
+	int dcd_up;
+	int dcd_down;
+	int cts_up;
+	int cts_down;
+};
+
+/*
+ * device instance data structure
+ */
+struct slgt_info {
+	void *if_ptr;		/* General purpose pointer (used by SPPP) */
+	struct tty_port port;
+
+	struct slgt_info *next_device;	/* device list link */
+
+	char device_name[25];
+	struct pci_dev *pdev;
+
+	int port_count;  /* count of ports on adapter */
+	int adapter_num; /* adapter instance number */
+	int port_num;    /* port instance number */
+
+	/* array of pointers to port contexts on this adapter */
+	struct slgt_info *port_array[SLGT_MAX_PORTS];
+
+	int			line;		/* tty line instance number */
+
+	struct mgsl_icount	icount;
+
+	int			timeout;
+	int			x_char;		/* xon/xoff character */
+	unsigned int		read_status_mask;
+	unsigned int 		ignore_status_mask;
+
+	wait_queue_head_t	status_event_wait_q;
+	wait_queue_head_t	event_wait_q;
+	struct timer_list	tx_timer;
+	struct timer_list	rx_timer;
+
+	unsigned int            gpio_present;
+	struct cond_wait        *gpio_wait_q;
+
+	spinlock_t lock;	/* spinlock for synchronizing with ISR */
+
+	struct work_struct task;
+	u32 pending_bh;
+	bool bh_requested;
+	bool bh_running;
+
+	int isr_overflow;
+	bool irq_requested;	/* true if IRQ requested */
+	bool irq_occurred;	/* for diagnostics use */
+
+	/* device configuration */
+
+	unsigned int bus_type;
+	unsigned int irq_level;
+	unsigned long irq_flags;
+
+	unsigned char __iomem * reg_addr;  /* memory mapped registers address */
+	u32 phys_reg_addr;
+	bool reg_addr_requested;
+
+	MGSL_PARAMS params;       /* communications parameters */
+	u32 idle_mode;
+	u32 max_frame_size;       /* as set by device config */
+
+	unsigned int rbuf_fill_level;
+	unsigned int rx_pio;
+	unsigned int if_mode;
+	unsigned int base_clock;
+	unsigned int xsync;
+	unsigned int xctrl;
+
+	/* device status */
+
+	bool rx_enabled;
+	bool rx_restart;
+
+	bool tx_enabled;
+	bool tx_active;
+
+	unsigned char signals;    /* serial signal states */
+	int init_error;  /* initialization error */
+
+	unsigned char *tx_buf;
+	int tx_count;
+
+	bool drop_rts_on_tx_done;
+	struct	_input_signal_events	input_signal_events;
+
+	int dcd_chkcount;	/* check counts to prevent */
+	int cts_chkcount;	/* too many IRQs if a signal */
+	int dsr_chkcount;	/* is floating */
+	int ri_chkcount;
+
+	char *bufs;		/* virtual address of DMA buffer lists */
+	dma_addr_t bufs_dma_addr; /* physical address of buffer descriptors */
+
+	unsigned int rbuf_count;
+	struct slgt_desc *rbufs;
+	unsigned int rbuf_current;
+	unsigned int rbuf_index;
+	unsigned int rbuf_fill_index;
+	unsigned short rbuf_fill_count;
+
+	unsigned int tbuf_count;
+	struct slgt_desc *tbufs;
+	unsigned int tbuf_current;
+	unsigned int tbuf_start;
+
+	unsigned char *tmp_rbuf;
+	unsigned int tmp_rbuf_count;
+
+	/* SPPP/Cisco HDLC device parts */
+
+	int netcount;
+	spinlock_t netlock;
+#if SYNCLINK_GENERIC_HDLC
+	struct net_device *netdev;
+#endif
+
+};
+
+static const MGSL_PARAMS default_params = {
+	.mode            = MGSL_MODE_HDLC,
+	.loopback        = 0,
+	.flags           = HDLC_FLAG_UNDERRUN_ABORT15,
+	.encoding        = HDLC_ENCODING_NRZI_SPACE,
+	.clock_speed     = 0,
+	.addr_filter     = 0xff,
+	.crc_type        = HDLC_CRC_16_CCITT,
+	.preamble_length = HDLC_PREAMBLE_LENGTH_8BITS,
+	.preamble        = HDLC_PREAMBLE_PATTERN_NONE,
+	.data_rate       = 9600,
+	.data_bits       = 8,
+	.stop_bits       = 1,
+	.parity          = ASYNC_PARITY_NONE
+};
+
+
+#define BH_RECEIVE  1
+#define BH_TRANSMIT 2
+#define BH_STATUS   4
+#define IO_PIN_SHUTDOWN_LIMIT 100
+
+#define DMABUFSIZE 256
+#define DESC_LIST_SIZE 4096
+
+#define MASK_PARITY  BIT1
+#define MASK_FRAMING BIT0
+#define MASK_BREAK   BIT14
+#define MASK_OVERRUN BIT4
+
+#define GSR   0x00 /* global status */
+#define JCR   0x04 /* JTAG control */
+#define IODR  0x08 /* GPIO direction */
+#define IOER  0x0c /* GPIO interrupt enable */
+#define IOVR  0x10 /* GPIO value */
+#define IOSR  0x14 /* GPIO interrupt status */
+#define TDR   0x80 /* tx data */
+#define RDR   0x80 /* rx data */
+#define TCR   0x82 /* tx control */
+#define TIR   0x84 /* tx idle */
+#define TPR   0x85 /* tx preamble */
+#define RCR   0x86 /* rx control */
+#define VCR   0x88 /* V.24 control */
+#define CCR   0x89 /* clock control */
+#define BDR   0x8a /* baud divisor */
+#define SCR   0x8c /* serial control */
+#define SSR   0x8e /* serial status */
+#define RDCSR 0x90 /* rx DMA control/status */
+#define TDCSR 0x94 /* tx DMA control/status */
+#define RDDAR 0x98 /* rx DMA descriptor address */
+#define TDDAR 0x9c /* tx DMA descriptor address */
+#define XSR   0x40 /* extended sync pattern */
+#define XCR   0x44 /* extended control */
+
+#define RXIDLE      BIT14
+#define RXBREAK     BIT14
+#define IRQ_TXDATA  BIT13
+#define IRQ_TXIDLE  BIT12
+#define IRQ_TXUNDER BIT11 /* HDLC */
+#define IRQ_RXDATA  BIT10
+#define IRQ_RXIDLE  BIT9  /* HDLC */
+#define IRQ_RXBREAK BIT9  /* async */
+#define IRQ_RXOVER  BIT8
+#define IRQ_DSR     BIT7
+#define IRQ_CTS     BIT6
+#define IRQ_DCD     BIT5
+#define IRQ_RI      BIT4
+#define IRQ_ALL     0x3ff0
+#define IRQ_MASTER  BIT0
+
+#define slgt_irq_on(info, mask) \
+	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) | (mask)))
+#define slgt_irq_off(info, mask) \
+	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) & ~(mask)))
+
+static __u8  rd_reg8(struct slgt_info *info, unsigned int addr);
+static void  wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value);
+static __u16 rd_reg16(struct slgt_info *info, unsigned int addr);
+static void  wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value);
+static __u32 rd_reg32(struct slgt_info *info, unsigned int addr);
+static void  wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value);
+
+static void  msc_set_vcr(struct slgt_info *info);
+
+static int  startup(struct slgt_info *info);
+static int  block_til_ready(struct tty_struct *tty, struct file * filp,struct slgt_info *info);
+static void shutdown(struct slgt_info *info);
+static void program_hw(struct slgt_info *info);
+static void change_params(struct slgt_info *info);
+
+static int  adapter_test(struct slgt_info *info);
+
+static void reset_port(struct slgt_info *info);
+static void async_mode(struct slgt_info *info);
+static void sync_mode(struct slgt_info *info);
+
+static void rx_stop(struct slgt_info *info);
+static void rx_start(struct slgt_info *info);
+static void reset_rbufs(struct slgt_info *info);
+static void free_rbufs(struct slgt_info *info, unsigned int first, unsigned int last);
+static bool rx_get_frame(struct slgt_info *info);
+static bool rx_get_buf(struct slgt_info *info);
+
+static void tx_start(struct slgt_info *info);
+static void tx_stop(struct slgt_info *info);
+static void tx_set_idle(struct slgt_info *info);
+static unsigned int tbuf_bytes(struct slgt_info *info);
+static void reset_tbufs(struct slgt_info *info);
+static void tdma_reset(struct slgt_info *info);
+static bool tx_load(struct slgt_info *info, const u8 *buf, unsigned int count);
+
+static void get_gtsignals(struct slgt_info *info);
+static void set_gtsignals(struct slgt_info *info);
+static void set_rate(struct slgt_info *info, u32 data_rate);
+
+static void bh_transmit(struct slgt_info *info);
+static void isr_txeom(struct slgt_info *info, unsigned short status);
+
+static void tx_timeout(struct timer_list *t);
+static void rx_timeout(struct timer_list *t);
+
+/*
+ * ioctl handlers
+ */
+static int  get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount);
+static int  get_params(struct slgt_info *info, MGSL_PARAMS __user *params);
+static int  set_params(struct slgt_info *info, MGSL_PARAMS __user *params);
+static int  get_txidle(struct slgt_info *info, int __user *idle_mode);
+static int  set_txidle(struct slgt_info *info, int idle_mode);
+static int  tx_enable(struct slgt_info *info, int enable);
+static int  tx_abort(struct slgt_info *info);
+static int  rx_enable(struct slgt_info *info, int enable);
+static int  modem_input_wait(struct slgt_info *info,int arg);
+static int  wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr);
+static int  get_interface(struct slgt_info *info, int __user *if_mode);
+static int  set_interface(struct slgt_info *info, int if_mode);
+static int  set_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
+static int  get_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
+static int  wait_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
+static int  get_xsync(struct slgt_info *info, int __user *if_mode);
+static int  set_xsync(struct slgt_info *info, int if_mode);
+static int  get_xctrl(struct slgt_info *info, int __user *if_mode);
+static int  set_xctrl(struct slgt_info *info, int if_mode);
+
+/*
+ * driver functions
+ */
+static void release_resources(struct slgt_info *info);
+
+/*
+ * DEBUG OUTPUT CODE
+ */
+#ifndef DBGINFO
+#define DBGINFO(fmt)
+#endif
+#ifndef DBGERR
+#define DBGERR(fmt)
+#endif
+#ifndef DBGBH
+#define DBGBH(fmt)
+#endif
+#ifndef DBGISR
+#define DBGISR(fmt)
+#endif
+
+#ifdef DBGDATA
+static void trace_block(struct slgt_info *info, const char *data, int count, const char *label)
+{
+	int i;
+	int linecount;
+	printk("%s %s data:\n",info->device_name, label);
+	while(count) {
+		linecount = (count > 16) ? 16 : count;
+		for(i=0; i < linecount; i++)
+			printk("%02X ",(unsigned char)data[i]);
+		for(;i<17;i++)
+			printk("   ");
+		for(i=0;i<linecount;i++) {
+			if (data[i]>=040 && data[i]<=0176)
+				printk("%c",data[i]);
+			else
+				printk(".");
+		}
+		printk("\n");
+		data  += linecount;
+		count -= linecount;
+	}
+}
+#else
+#define DBGDATA(info, buf, size, label)
+#endif
+
+#ifdef DBGTBUF
+static void dump_tbufs(struct slgt_info *info)
+{
+	int i;
+	printk("tbuf_current=%d\n", info->tbuf_current);
+	for (i=0 ; i < info->tbuf_count ; i++) {
+		printk("%d: count=%04X status=%04X\n",
+			i, le16_to_cpu(info->tbufs[i].count), le16_to_cpu(info->tbufs[i].status));
+	}
+}
+#else
+#define DBGTBUF(info)
+#endif
+
+#ifdef DBGRBUF
+static void dump_rbufs(struct slgt_info *info)
+{
+	int i;
+	printk("rbuf_current=%d\n", info->rbuf_current);
+	for (i=0 ; i < info->rbuf_count ; i++) {
+		printk("%d: count=%04X status=%04X\n",
+			i, le16_to_cpu(info->rbufs[i].count), le16_to_cpu(info->rbufs[i].status));
+	}
+}
+#else
+#define DBGRBUF(info)
+#endif
+
+static inline int sanity_check(struct slgt_info *info, char *devname, const char *name)
+{
+#ifdef SANITY_CHECK
+	if (!info) {
+		printk("null struct slgt_info for (%s) in %s\n", devname, name);
+		return 1;
+	}
+#else
+	if (!info)
+		return 1;
+#endif
+	return 0;
+}
+
+/*
+ * line discipline callback wrappers
+ *
+ * The wrappers maintain line discipline references
+ * while calling into the line discipline.
+ *
+ * ldisc_receive_buf  - pass receive data to line discipline
+ */
+static void ldisc_receive_buf(struct tty_struct *tty,
+			      const __u8 *data, char *flags, int count)
+{
+	struct tty_ldisc *ld;
+	if (!tty)
+		return;
+	ld = tty_ldisc_ref(tty);
+	if (ld) {
+		if (ld->ops->receive_buf)
+			ld->ops->receive_buf(tty, data, flags, count);
+		tty_ldisc_deref(ld);
+	}
+}
+
+/* tty callbacks */
+
+static int open(struct tty_struct *tty, struct file *filp)
+{
+	struct slgt_info *info;
+	int retval, line;
+	unsigned long flags;
+
+	line = tty->index;
+	if (line >= slgt_device_count) {
+		DBGERR(("%s: open with invalid line #%d.\n", driver_name, line));
+		return -ENODEV;
+	}
+
+	info = slgt_device_list;
+	while(info && info->line != line)
+		info = info->next_device;
+	if (sanity_check(info, tty->name, "open"))
+		return -ENODEV;
+	if (info->init_error) {
+		DBGERR(("%s init error=%d\n", info->device_name, info->init_error));
+		return -ENODEV;
+	}
+
+	tty->driver_data = info;
+	info->port.tty = tty;
+
+	DBGINFO(("%s open, old ref count = %d\n", info->device_name, info->port.count));
+
+	mutex_lock(&info->port.mutex);
+
+	spin_lock_irqsave(&info->netlock, flags);
+	if (info->netcount) {
+		retval = -EBUSY;
+		spin_unlock_irqrestore(&info->netlock, flags);
+		mutex_unlock(&info->port.mutex);
+		goto cleanup;
+	}
+	info->port.count++;
+	spin_unlock_irqrestore(&info->netlock, flags);
+
+	if (info->port.count == 1) {
+		/* 1st open on this device, init hardware */
+		retval = startup(info);
+		if (retval < 0) {
+			mutex_unlock(&info->port.mutex);
+			goto cleanup;
+		}
+	}
+	mutex_unlock(&info->port.mutex);
+	retval = block_til_ready(tty, filp, info);
+	if (retval) {
+		DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval));
+		goto cleanup;
+	}
+
+	retval = 0;
+
+cleanup:
+	if (retval) {
+		if (tty->count == 1)
+			info->port.tty = NULL; /* tty layer will release tty struct */
+		if(info->port.count)
+			info->port.count--;
+	}
+
+	DBGINFO(("%s open rc=%d\n", info->device_name, retval));
+	return retval;
+}
+
+static void close(struct tty_struct *tty, struct file *filp)
+{
+	struct slgt_info *info = tty->driver_data;
+
+	if (sanity_check(info, tty->name, "close"))
+		return;
+	DBGINFO(("%s close entry, count=%d\n", info->device_name, info->port.count));
+
+	if (tty_port_close_start(&info->port, tty, filp) == 0)
+		goto cleanup;
+
+	mutex_lock(&info->port.mutex);
+	if (tty_port_initialized(&info->port))
+ 		wait_until_sent(tty, info->timeout);
+	flush_buffer(tty);
+	tty_ldisc_flush(tty);
+
+	shutdown(info);
+	mutex_unlock(&info->port.mutex);
+
+	tty_port_close_end(&info->port, tty);
+	info->port.tty = NULL;
+cleanup:
+	DBGINFO(("%s close exit, count=%d\n", tty->driver->name, info->port.count));
+}
+
+static void hangup(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "hangup"))
+		return;
+	DBGINFO(("%s hangup\n", info->device_name));
+
+	flush_buffer(tty);
+
+	mutex_lock(&info->port.mutex);
+	shutdown(info);
+
+	spin_lock_irqsave(&info->port.lock, flags);
+	info->port.count = 0;
+	info->port.tty = NULL;
+	spin_unlock_irqrestore(&info->port.lock, flags);
+	tty_port_set_active(&info->port, false);
+	mutex_unlock(&info->port.mutex);
+
+	wake_up_interruptible(&info->port.open_wait);
+}
+
+static void set_termios(struct tty_struct *tty,
+			const struct ktermios *old_termios)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	DBGINFO(("%s set_termios\n", tty->driver->name));
+
+	change_params(info);
+
+	/* Handle transition to B0 status */
+	if ((old_termios->c_cflag & CBAUD) && !C_BAUD(tty)) {
+		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
+		spin_lock_irqsave(&info->lock,flags);
+		set_gtsignals(info);
+		spin_unlock_irqrestore(&info->lock,flags);
+	}
+
+	/* Handle transition away from B0 status */
+	if (!(old_termios->c_cflag & CBAUD) && C_BAUD(tty)) {
+		info->signals |= SerialSignal_DTR;
+		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
+			info->signals |= SerialSignal_RTS;
+		spin_lock_irqsave(&info->lock,flags);
+	 	set_gtsignals(info);
+		spin_unlock_irqrestore(&info->lock,flags);
+	}
+
+	/* Handle turning off CRTSCTS */
+	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
+		tty->hw_stopped = false;
+		tx_release(tty);
+	}
+}
+
+static void update_tx_timer(struct slgt_info *info)
+{
+	/*
+	 * use worst case speed of 1200bps to calculate transmit timeout
+	 * based on data in buffers (tbuf_bytes) and FIFO (128 bytes)
+	 */
+	if (info->params.mode == MGSL_MODE_HDLC) {
+		int timeout  = (tbuf_bytes(info) * 7) + 1000;
+		mod_timer(&info->tx_timer, jiffies + msecs_to_jiffies(timeout));
+	}
+}
+
+static ssize_t write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	int ret = 0;
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "write"))
+		return -EIO;
+
+	DBGINFO(("%s write count=%zu\n", info->device_name, count));
+
+	if (!info->tx_buf || (count > info->max_frame_size))
+		return -EIO;
+
+	if (!count || tty->flow.stopped || tty->hw_stopped)
+		return 0;
+
+	spin_lock_irqsave(&info->lock, flags);
+
+	if (info->tx_count) {
+		/* send accumulated data from send_char() */
+		if (!tx_load(info, info->tx_buf, info->tx_count))
+			goto cleanup;
+		info->tx_count = 0;
+	}
+
+	if (tx_load(info, buf, count))
+		ret = count;
+
+cleanup:
+	spin_unlock_irqrestore(&info->lock, flags);
+	DBGINFO(("%s write rc=%d\n", info->device_name, ret));
+	return ret;
+}
+
+static int put_char(struct tty_struct *tty, u8 ch)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+	int ret = 0;
+
+	if (sanity_check(info, tty->name, "put_char"))
+		return 0;
+	DBGINFO(("%s put_char(%u)\n", info->device_name, ch));
+	if (!info->tx_buf)
+		return 0;
+	spin_lock_irqsave(&info->lock,flags);
+	if (info->tx_count < info->max_frame_size) {
+		info->tx_buf[info->tx_count++] = ch;
+		ret = 1;
+	}
+	spin_unlock_irqrestore(&info->lock,flags);
+	return ret;
+}
+
+static void send_xchar(struct tty_struct *tty, char ch)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "send_xchar"))
+		return;
+	DBGINFO(("%s send_xchar(%d)\n", info->device_name, ch));
+	info->x_char = ch;
+	if (ch) {
+		spin_lock_irqsave(&info->lock,flags);
+		if (!info->tx_enabled)
+		 	tx_start(info);
+		spin_unlock_irqrestore(&info->lock,flags);
+	}
+}
+
+static void wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long orig_jiffies, char_time;
+
+	if (!info )
+		return;
+	if (sanity_check(info, tty->name, "wait_until_sent"))
+		return;
+	DBGINFO(("%s wait_until_sent entry\n", info->device_name));
+	if (!tty_port_initialized(&info->port))
+		goto exit;
+
+	orig_jiffies = jiffies;
+
+	/* Set check interval to 1/5 of estimated time to
+	 * send a character, and make it at least 1. The check
+	 * interval should also be less than the timeout.
+	 * Note: use tight timings here to satisfy the NIST-PCTS.
+	 */
+
+	if (info->params.data_rate) {
+	       	char_time = info->timeout/(32 * 5);
+		if (!char_time)
+			char_time++;
+	} else
+		char_time = 1;
+
+	if (timeout)
+		char_time = min_t(unsigned long, char_time, timeout);
+
+	while (info->tx_active) {
+		msleep_interruptible(jiffies_to_msecs(char_time));
+		if (signal_pending(current))
+			break;
+		if (timeout && time_after(jiffies, orig_jiffies + timeout))
+			break;
+	}
+exit:
+	DBGINFO(("%s wait_until_sent exit\n", info->device_name));
+}
+
+static unsigned int write_room(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned int ret;
+
+	if (sanity_check(info, tty->name, "write_room"))
+		return 0;
+	ret = (info->tx_active) ? 0 : HDLC_MAX_FRAME_SIZE;
+	DBGINFO(("%s write_room=%u\n", info->device_name, ret));
+	return ret;
+}
+
+static void flush_chars(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "flush_chars"))
+		return;
+	DBGINFO(("%s flush_chars entry tx_count=%d\n", info->device_name, info->tx_count));
+
+	if (info->tx_count <= 0 || tty->flow.stopped ||
+	    tty->hw_stopped || !info->tx_buf)
+		return;
+
+	DBGINFO(("%s flush_chars start transmit\n", info->device_name));
+
+	spin_lock_irqsave(&info->lock,flags);
+	if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
+		info->tx_count = 0;
+	spin_unlock_irqrestore(&info->lock,flags);
+}
+
+static void flush_buffer(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "flush_buffer"))
+		return;
+	DBGINFO(("%s flush_buffer\n", info->device_name));
+
+	spin_lock_irqsave(&info->lock, flags);
+	info->tx_count = 0;
+	spin_unlock_irqrestore(&info->lock, flags);
+
+	tty_wakeup(tty);
+}
+
+/*
+ * throttle (stop) transmitter
+ */
+static void tx_hold(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "tx_hold"))
+		return;
+	DBGINFO(("%s tx_hold\n", info->device_name));
+	spin_lock_irqsave(&info->lock,flags);
+	if (info->tx_enabled && info->params.mode == MGSL_MODE_ASYNC)
+	 	tx_stop(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+}
+
+/*
+ * release (start) transmitter
+ */
+static void tx_release(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "tx_release"))
+		return;
+	DBGINFO(("%s tx_release\n", info->device_name));
+	spin_lock_irqsave(&info->lock, flags);
+	if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
+		info->tx_count = 0;
+	spin_unlock_irqrestore(&info->lock, flags);
+}
+
+/*
+ * Service an IOCTL request
+ *
+ * Arguments
+ *
+ * 	tty	pointer to tty instance data
+ * 	cmd	IOCTL command code
+ * 	arg	command argument/context
+ *
+ * Return 0 if success, otherwise error code
+ */
+static int ioctl(struct tty_struct *tty,
+		 unsigned int cmd, unsigned long arg)
+{
+	struct slgt_info *info = tty->driver_data;
+	void __user *argp = (void __user *)arg;
+	int ret;
+
+	if (sanity_check(info, tty->name, "ioctl"))
+		return -ENODEV;
+	DBGINFO(("%s ioctl() cmd=%08X\n", info->device_name, cmd));
+
+	if (cmd != TIOCMIWAIT) {
+		if (tty_io_error(tty))
+		    return -EIO;
+	}
+
+	switch (cmd) {
+	case MGSL_IOCWAITEVENT:
+		return wait_mgsl_event(info, argp);
+	case TIOCMIWAIT:
+		return modem_input_wait(info,(int)arg);
+	case MGSL_IOCSGPIO:
+		return set_gpio(info, argp);
+	case MGSL_IOCGGPIO:
+		return get_gpio(info, argp);
+	case MGSL_IOCWAITGPIO:
+		return wait_gpio(info, argp);
+	case MGSL_IOCGXSYNC:
+		return get_xsync(info, argp);
+	case MGSL_IOCSXSYNC:
+		return set_xsync(info, (int)arg);
+	case MGSL_IOCGXCTRL:
+		return get_xctrl(info, argp);
+	case MGSL_IOCSXCTRL:
+		return set_xctrl(info, (int)arg);
+	}
+	mutex_lock(&info->port.mutex);
+	switch (cmd) {
+	case MGSL_IOCGPARAMS:
+		ret = get_params(info, argp);
+		break;
+	case MGSL_IOCSPARAMS:
+		ret = set_params(info, argp);
+		break;
+	case MGSL_IOCGTXIDLE:
+		ret = get_txidle(info, argp);
+		break;
+	case MGSL_IOCSTXIDLE:
+		ret = set_txidle(info, (int)arg);
+		break;
+	case MGSL_IOCTXENABLE:
+		ret = tx_enable(info, (int)arg);
+		break;
+	case MGSL_IOCRXENABLE:
+		ret = rx_enable(info, (int)arg);
+		break;
+	case MGSL_IOCTXABORT:
+		ret = tx_abort(info);
+		break;
+	case MGSL_IOCGSTATS:
+		ret = get_stats(info, argp);
+		break;
+	case MGSL_IOCGIF:
+		ret = get_interface(info, argp);
+		break;
+	case MGSL_IOCSIF:
+		ret = set_interface(info,(int)arg);
+		break;
+	default:
+		ret = -ENOIOCTLCMD;
+	}
+	mutex_unlock(&info->port.mutex);
+	return ret;
+}
+
+static int get_icount(struct tty_struct *tty,
+				struct serial_icounter_struct *icount)
+
+{
+	struct slgt_info *info = tty->driver_data;
+	struct mgsl_icount cnow;	/* kernel counter temps */
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->lock,flags);
+	cnow = info->icount;
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	icount->cts = cnow.cts;
+	icount->dsr = cnow.dsr;
+	icount->rng = cnow.rng;
+	icount->dcd = cnow.dcd;
+	icount->rx = cnow.rx;
+	icount->tx = cnow.tx;
+	icount->frame = cnow.frame;
+	icount->overrun = cnow.overrun;
+	icount->parity = cnow.parity;
+	icount->brk = cnow.brk;
+	icount->buf_overrun = cnow.buf_overrun;
+
+	return 0;
+}
+
+/*
+ * support for 32 bit ioctl calls on 64 bit systems
+ */
+#ifdef CONFIG_COMPAT
+static long get_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *user_params)
+{
+	struct MGSL_PARAMS32 tmp_params;
+
+	DBGINFO(("%s get_params32\n", info->device_name));
+	memset(&tmp_params, 0, sizeof(tmp_params));
+	tmp_params.mode            = (compat_ulong_t)info->params.mode;
+	tmp_params.loopback        = info->params.loopback;
+	tmp_params.flags           = info->params.flags;
+	tmp_params.encoding        = info->params.encoding;
+	tmp_params.clock_speed     = (compat_ulong_t)info->params.clock_speed;
+	tmp_params.addr_filter     = info->params.addr_filter;
+	tmp_params.crc_type        = info->params.crc_type;
+	tmp_params.preamble_length = info->params.preamble_length;
+	tmp_params.preamble        = info->params.preamble;
+	tmp_params.data_rate       = (compat_ulong_t)info->params.data_rate;
+	tmp_params.data_bits       = info->params.data_bits;
+	tmp_params.stop_bits       = info->params.stop_bits;
+	tmp_params.parity          = info->params.parity;
+	if (copy_to_user(user_params, &tmp_params, sizeof(struct MGSL_PARAMS32)))
+		return -EFAULT;
+	return 0;
+}
+
+static long set_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *new_params)
+{
+	struct MGSL_PARAMS32 tmp_params;
+	unsigned long flags;
+
+	DBGINFO(("%s set_params32\n", info->device_name));
+	if (copy_from_user(&tmp_params, new_params, sizeof(struct MGSL_PARAMS32)))
+		return -EFAULT;
+
+	spin_lock_irqsave(&info->lock, flags);
+	if (tmp_params.mode == MGSL_MODE_BASE_CLOCK) {
+		info->base_clock = tmp_params.clock_speed;
+	} else {
+		info->params.mode            = tmp_params.mode;
+		info->params.loopback        = tmp_params.loopback;
+		info->params.flags           = tmp_params.flags;
+		info->params.encoding        = tmp_params.encoding;
+		info->params.clock_speed     = tmp_params.clock_speed;
+		info->params.addr_filter     = tmp_params.addr_filter;
+		info->params.crc_type        = tmp_params.crc_type;
+		info->params.preamble_length = tmp_params.preamble_length;
+		info->params.preamble        = tmp_params.preamble;
+		info->params.data_rate       = tmp_params.data_rate;
+		info->params.data_bits       = tmp_params.data_bits;
+		info->params.stop_bits       = tmp_params.stop_bits;
+		info->params.parity          = tmp_params.parity;
+	}
+	spin_unlock_irqrestore(&info->lock, flags);
+
+	program_hw(info);
+
+	return 0;
+}
+
+static long slgt_compat_ioctl(struct tty_struct *tty,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct slgt_info *info = tty->driver_data;
+	int rc;
+
+	if (sanity_check(info, tty->name, "compat_ioctl"))
+		return -ENODEV;
+	DBGINFO(("%s compat_ioctl() cmd=%08X\n", info->device_name, cmd));
+
+	switch (cmd) {
+	case MGSL_IOCSPARAMS32:
+		rc = set_params32(info, compat_ptr(arg));
+		break;
+
+	case MGSL_IOCGPARAMS32:
+		rc = get_params32(info, compat_ptr(arg));
+		break;
+
+	case MGSL_IOCGPARAMS:
+	case MGSL_IOCSPARAMS:
+	case MGSL_IOCGTXIDLE:
+	case MGSL_IOCGSTATS:
+	case MGSL_IOCWAITEVENT:
+	case MGSL_IOCGIF:
+	case MGSL_IOCSGPIO:
+	case MGSL_IOCGGPIO:
+	case MGSL_IOCWAITGPIO:
+	case MGSL_IOCGXSYNC:
+	case MGSL_IOCGXCTRL:
+		rc = ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
+		break;
+	default:
+		rc = ioctl(tty, cmd, arg);
+	}
+	DBGINFO(("%s compat_ioctl() cmd=%08X rc=%d\n", info->device_name, cmd, rc));
+	return rc;
+}
+#else
+#define slgt_compat_ioctl NULL
+#endif /* ifdef CONFIG_COMPAT */
+
+/*
+ * proc fs support
+ */
+static inline void line_info(struct seq_file *m, struct slgt_info *info)
+{
+	char stat_buf[30];
+	unsigned long flags;
+
+	seq_printf(m, "%s: IO=%08X IRQ=%d MaxFrameSize=%u\n",
+		      info->device_name, info->phys_reg_addr,
+		      info->irq_level, info->max_frame_size);
+
+	/* output current serial signal states */
+	spin_lock_irqsave(&info->lock,flags);
+	get_gtsignals(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	stat_buf[0] = 0;
+	stat_buf[1] = 0;
+	if (info->signals & SerialSignal_RTS)
+		strcat(stat_buf, "|RTS");
+	if (info->signals & SerialSignal_CTS)
+		strcat(stat_buf, "|CTS");
+	if (info->signals & SerialSignal_DTR)
+		strcat(stat_buf, "|DTR");
+	if (info->signals & SerialSignal_DSR)
+		strcat(stat_buf, "|DSR");
+	if (info->signals & SerialSignal_DCD)
+		strcat(stat_buf, "|CD");
+	if (info->signals & SerialSignal_RI)
+		strcat(stat_buf, "|RI");
+
+	if (info->params.mode != MGSL_MODE_ASYNC) {
+		seq_printf(m, "\tHDLC txok:%d rxok:%d",
+			       info->icount.txok, info->icount.rxok);
+		if (info->icount.txunder)
+			seq_printf(m, " txunder:%d", info->icount.txunder);
+		if (info->icount.txabort)
+			seq_printf(m, " txabort:%d", info->icount.txabort);
+		if (info->icount.rxshort)
+			seq_printf(m, " rxshort:%d", info->icount.rxshort);
+		if (info->icount.rxlong)
+			seq_printf(m, " rxlong:%d", info->icount.rxlong);
+		if (info->icount.rxover)
+			seq_printf(m, " rxover:%d", info->icount.rxover);
+		if (info->icount.rxcrc)
+			seq_printf(m, " rxcrc:%d", info->icount.rxcrc);
+	} else {
+		seq_printf(m, "\tASYNC tx:%d rx:%d",
+			       info->icount.tx, info->icount.rx);
+		if (info->icount.frame)
+			seq_printf(m, " fe:%d", info->icount.frame);
+		if (info->icount.parity)
+			seq_printf(m, " pe:%d", info->icount.parity);
+		if (info->icount.brk)
+			seq_printf(m, " brk:%d", info->icount.brk);
+		if (info->icount.overrun)
+			seq_printf(m, " oe:%d", info->icount.overrun);
+	}
+
+	/* Append serial signal status to end */
+	seq_printf(m, " %s\n", stat_buf+1);
+
+	seq_printf(m, "\ttxactive=%d bh_req=%d bh_run=%d pending_bh=%x\n",
+		       info->tx_active,info->bh_requested,info->bh_running,
+		       info->pending_bh);
+}
+
+/* Called to print information about devices
+ */
+static int synclink_gt_proc_show(struct seq_file *m, void *v)
+{
+	struct slgt_info *info;
+
+	seq_puts(m, "synclink_gt driver\n");
+
+	info = slgt_device_list;
+	while( info ) {
+		line_info(m, info);
+		info = info->next_device;
+	}
+	return 0;
+}
+
+/*
+ * return count of bytes in transmit buffer
+ */
+static unsigned int chars_in_buffer(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned int count;
+	if (sanity_check(info, tty->name, "chars_in_buffer"))
+		return 0;
+	count = tbuf_bytes(info);
+	DBGINFO(("%s chars_in_buffer()=%u\n", info->device_name, count));
+	return count;
+}
+
+/*
+ * signal remote device to throttle send data (our receive data)
+ */
+static void throttle(struct tty_struct * tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "throttle"))
+		return;
+	DBGINFO(("%s throttle\n", info->device_name));
+	if (I_IXOFF(tty))
+		send_xchar(tty, STOP_CHAR(tty));
+	if (C_CRTSCTS(tty)) {
+		spin_lock_irqsave(&info->lock,flags);
+		info->signals &= ~SerialSignal_RTS;
+		set_gtsignals(info);
+		spin_unlock_irqrestore(&info->lock,flags);
+	}
+}
+
+/*
+ * signal remote device to stop throttling send data (our receive data)
+ */
+static void unthrottle(struct tty_struct * tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "unthrottle"))
+		return;
+	DBGINFO(("%s unthrottle\n", info->device_name));
+	if (I_IXOFF(tty)) {
+		if (info->x_char)
+			info->x_char = 0;
+		else
+			send_xchar(tty, START_CHAR(tty));
+	}
+	if (C_CRTSCTS(tty)) {
+		spin_lock_irqsave(&info->lock,flags);
+		info->signals |= SerialSignal_RTS;
+		set_gtsignals(info);
+		spin_unlock_irqrestore(&info->lock,flags);
+	}
+}
+
+/*
+ * set or clear transmit break condition
+ * break_state	-1=set break condition, 0=clear
+ */
+static int set_break(struct tty_struct *tty, int break_state)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned short value;
+	unsigned long flags;
+
+	if (sanity_check(info, tty->name, "set_break"))
+		return -EINVAL;
+	DBGINFO(("%s set_break(%d)\n", info->device_name, break_state));
+
+	spin_lock_irqsave(&info->lock,flags);
+	value = rd_reg16(info, TCR);
+ 	if (break_state == -1)
+		value |= BIT6;
+	else
+		value &= ~BIT6;
+	wr_reg16(info, TCR, value);
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+#if SYNCLINK_GENERIC_HDLC
+
+/**
+ * hdlcdev_attach - called by generic HDLC layer when protocol selected (PPP, frame relay, etc.)
+ * @dev:      pointer to network device structure
+ * @encoding: serial encoding setting
+ * @parity:   FCS setting
+ *
+ * Set encoding and frame check sequence (FCS) options.
+ *
+ * Return: 0 if success, otherwise error code
+ */
+static int hdlcdev_attach(struct net_device *dev, unsigned short encoding,
+			  unsigned short parity)
+{
+	struct slgt_info *info = dev_to_port(dev);
+	unsigned char  new_encoding;
+	unsigned short new_crctype;
+
+	/* return error if TTY interface open */
+	if (info->port.count)
+		return -EBUSY;
+
+	DBGINFO(("%s hdlcdev_attach\n", info->device_name));
+
+	switch (encoding)
+	{
+	case ENCODING_NRZ:        new_encoding = HDLC_ENCODING_NRZ; break;
+	case ENCODING_NRZI:       new_encoding = HDLC_ENCODING_NRZI_SPACE; break;
+	case ENCODING_FM_MARK:    new_encoding = HDLC_ENCODING_BIPHASE_MARK; break;
+	case ENCODING_FM_SPACE:   new_encoding = HDLC_ENCODING_BIPHASE_SPACE; break;
+	case ENCODING_MANCHESTER: new_encoding = HDLC_ENCODING_BIPHASE_LEVEL; break;
+	default: return -EINVAL;
+	}
+
+	switch (parity)
+	{
+	case PARITY_NONE:            new_crctype = HDLC_CRC_NONE; break;
+	case PARITY_CRC16_PR1_CCITT: new_crctype = HDLC_CRC_16_CCITT; break;
+	case PARITY_CRC32_PR1_CCITT: new_crctype = HDLC_CRC_32_CCITT; break;
+	default: return -EINVAL;
+	}
+
+	info->params.encoding = new_encoding;
+	info->params.crc_type = new_crctype;
+
+	/* if network interface up, reprogram hardware */
+	if (info->netcount)
+		program_hw(info);
+
+	return 0;
+}
+
+/**
+ * hdlcdev_xmit - called by generic HDLC layer to send a frame
+ * @skb: socket buffer containing HDLC frame
+ * @dev: pointer to network device structure
+ */
+static netdev_tx_t hdlcdev_xmit(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	struct slgt_info *info = dev_to_port(dev);
+	unsigned long flags;
+
+	DBGINFO(("%s hdlc_xmit\n", dev->name));
+
+	if (!skb->len)
+		return NETDEV_TX_OK;
+
+	/* stop sending until this frame completes */
+	netif_stop_queue(dev);
+
+	/* update network statistics */
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += skb->len;
+
+	/* save start time for transmit timeout detection */
+	netif_trans_update(dev);
+
+	spin_lock_irqsave(&info->lock, flags);
+	tx_load(info, skb->data, skb->len);
+	spin_unlock_irqrestore(&info->lock, flags);
+
+	/* done with socket buffer, so free it */
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+/**
+ * hdlcdev_open - called by network layer when interface enabled
+ * @dev: pointer to network device structure
+ *
+ * Claim resources and initialize hardware.
+ *
+ * Return: 0 if success, otherwise error code
+ */
+static int hdlcdev_open(struct net_device *dev)
+{
+	struct slgt_info *info = dev_to_port(dev);
+	int rc;
+	unsigned long flags;
+
+	DBGINFO(("%s hdlcdev_open\n", dev->name));
+
+	/* arbitrate between network and tty opens */
+	spin_lock_irqsave(&info->netlock, flags);
+	if (info->port.count != 0 || info->netcount != 0) {
+		DBGINFO(("%s hdlc_open busy\n", dev->name));
+		spin_unlock_irqrestore(&info->netlock, flags);
+		return -EBUSY;
+	}
+	info->netcount=1;
+	spin_unlock_irqrestore(&info->netlock, flags);
+
+	/* claim resources and init adapter */
+	if ((rc = startup(info)) != 0) {
+		spin_lock_irqsave(&info->netlock, flags);
+		info->netcount=0;
+		spin_unlock_irqrestore(&info->netlock, flags);
+		return rc;
+	}
+
+	/* generic HDLC layer open processing */
+	rc = hdlc_open(dev);
+	if (rc) {
+		shutdown(info);
+		spin_lock_irqsave(&info->netlock, flags);
+		info->netcount = 0;
+		spin_unlock_irqrestore(&info->netlock, flags);
+		return rc;
+	}
+
+	/* assert RTS and DTR, apply hardware settings */
+	info->signals |= SerialSignal_RTS | SerialSignal_DTR;
+	program_hw(info);
+
+	/* enable network layer transmit */
+	netif_trans_update(dev);
+	netif_start_queue(dev);
+
+	/* inform generic HDLC layer of current DCD status */
+	spin_lock_irqsave(&info->lock, flags);
+	get_gtsignals(info);
+	spin_unlock_irqrestore(&info->lock, flags);
+	if (info->signals & SerialSignal_DCD)
+		netif_carrier_on(dev);
+	else
+		netif_carrier_off(dev);
+	return 0;
+}
+
+/**
+ * hdlcdev_close - called by network layer when interface is disabled
+ * @dev:  pointer to network device structure
+ *
+ * Shutdown hardware and release resources.
+ *
+ * Return: 0 if success, otherwise error code
+ */
+static int hdlcdev_close(struct net_device *dev)
+{
+	struct slgt_info *info = dev_to_port(dev);
+	unsigned long flags;
+
+	DBGINFO(("%s hdlcdev_close\n", dev->name));
+
+	netif_stop_queue(dev);
+
+	/* shutdown adapter and release resources */
+	shutdown(info);
+
+	hdlc_close(dev);
+
+	spin_lock_irqsave(&info->netlock, flags);
+	info->netcount=0;
+	spin_unlock_irqrestore(&info->netlock, flags);
+
+	return 0;
+}
+
+/**
+ * hdlcdev_ioctl - called by network layer to process IOCTL call to network device
+ * @dev: pointer to network device structure
+ * @ifr: pointer to network interface request structure
+ * @cmd: IOCTL command code
+ *
+ * Return: 0 if success, otherwise error code
+ */
+static int hdlcdev_ioctl(struct net_device *dev, struct if_settings *ifs)
+{
+	const size_t size = sizeof(sync_serial_settings);
+	sync_serial_settings new_line;
+	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
+	struct slgt_info *info = dev_to_port(dev);
+	unsigned int flags;
+
+	DBGINFO(("%s hdlcdev_ioctl\n", dev->name));
+
+	/* return error if TTY interface open */
+	if (info->port.count)
+		return -EBUSY;
+
+	memset(&new_line, 0, sizeof(new_line));
+
+	switch (ifs->type) {
+	case IF_GET_IFACE: /* return current sync_serial_settings */
+
+		ifs->type = IF_IFACE_SYNC_SERIAL;
+		if (ifs->size < size) {
+			ifs->size = size; /* data size wanted */
+			return -ENOBUFS;
+		}
+
+		flags = info->params.flags & (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
+					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
+					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
+					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
+
+		switch (flags){
+		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
+		case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
+		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_TXINT; break;
+		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN): new_line.clock_type = CLOCK_TXFROMRX; break;
+		default: new_line.clock_type = CLOCK_DEFAULT;
+		}
+
+		new_line.clock_rate = info->params.clock_speed;
+		new_line.loopback   = info->params.loopback ? 1:0;
+
+		if (copy_to_user(line, &new_line, size))
+			return -EFAULT;
+		return 0;
+
+	case IF_IFACE_SYNC_SERIAL: /* set sync_serial_settings */
+
+		if(!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (copy_from_user(&new_line, line, size))
+			return -EFAULT;
+
+		switch (new_line.clock_type)
+		{
+		case CLOCK_EXT:      flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN; break;
+		case CLOCK_TXFROMRX: flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN; break;
+		case CLOCK_INT:      flags = HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG;    break;
+		case CLOCK_TXINT:    flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG;    break;
+		case CLOCK_DEFAULT:  flags = info->params.flags &
+					     (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
+					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
+					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
+					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN); break;
+		default: return -EINVAL;
+		}
+
+		if (new_line.loopback != 0 && new_line.loopback != 1)
+			return -EINVAL;
+
+		info->params.flags &= ~(HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
+					HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
+					HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
+					HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
+		info->params.flags |= flags;
+
+		info->params.loopback = new_line.loopback;
+
+		if (flags & (HDLC_FLAG_RXC_BRG | HDLC_FLAG_TXC_BRG))
+			info->params.clock_speed = new_line.clock_rate;
+		else
+			info->params.clock_speed = 0;
+
+		/* if network interface up, reprogram hardware */
+		if (info->netcount)
+			program_hw(info);
+		return 0;
+
+	default:
+		return hdlc_ioctl(dev, ifs);
+	}
+}
+
+/**
+ * hdlcdev_tx_timeout - called by network layer when transmit timeout is detected
+ * @dev: pointer to network device structure
+ * @txqueue: unused
+ */
+static void hdlcdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
+{
+	struct slgt_info *info = dev_to_port(dev);
+	unsigned long flags;
+
+	DBGINFO(("%s hdlcdev_tx_timeout\n", dev->name));
+
+	dev->stats.tx_errors++;
+	dev->stats.tx_aborted_errors++;
+
+	spin_lock_irqsave(&info->lock,flags);
+	tx_stop(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	netif_wake_queue(dev);
+}
+
+/**
+ * hdlcdev_tx_done - called by device driver when transmit completes
+ * @info: pointer to device instance information
+ *
+ * Reenable network layer transmit if stopped.
+ */
+static void hdlcdev_tx_done(struct slgt_info *info)
+{
+	if (netif_queue_stopped(info->netdev))
+		netif_wake_queue(info->netdev);
+}
+
+/**
+ * hdlcdev_rx - called by device driver when frame received
+ * @info: pointer to device instance information
+ * @buf:  pointer to buffer contianing frame data
+ * @size: count of data bytes in buf
+ *
+ * Pass frame to network layer.
+ */
+static void hdlcdev_rx(struct slgt_info *info, char *buf, int size)
+{
+	struct sk_buff *skb = dev_alloc_skb(size);
+	struct net_device *dev = info->netdev;
+
+	DBGINFO(("%s hdlcdev_rx\n", dev->name));
+
+	if (skb == NULL) {
+		DBGERR(("%s: can't alloc skb, drop packet\n", dev->name));
+		dev->stats.rx_dropped++;
+		return;
+	}
+
+	skb_put_data(skb, buf, size);
+
+	skb->protocol = hdlc_type_trans(skb, dev);
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += size;
+
+	netif_rx(skb);
+}
+
+static const struct net_device_ops hdlcdev_ops = {
+	.ndo_open       = hdlcdev_open,
+	.ndo_stop       = hdlcdev_close,
+	.ndo_start_xmit = hdlc_start_xmit,
+	.ndo_siocwandev = hdlcdev_ioctl,
+	.ndo_tx_timeout = hdlcdev_tx_timeout,
+};
+
+/**
+ * hdlcdev_init - called by device driver when adding device instance
+ * @info: pointer to device instance information
+ *
+ * Do generic HDLC initialization.
+ *
+ * Return: 0 if success, otherwise error code
+ */
+static int hdlcdev_init(struct slgt_info *info)
+{
+	int rc;
+	struct net_device *dev;
+	hdlc_device *hdlc;
+
+	/* allocate and initialize network and HDLC layer objects */
+
+	dev = alloc_hdlcdev(info);
+	if (!dev) {
+		printk(KERN_ERR "%s hdlc device alloc failure\n", info->device_name);
+		return -ENOMEM;
+	}
+
+	/* for network layer reporting purposes only */
+	dev->mem_start = info->phys_reg_addr;
+	dev->mem_end   = info->phys_reg_addr + SLGT_REG_SIZE - 1;
+	dev->irq       = info->irq_level;
+
+	/* network layer callbacks and settings */
+	dev->netdev_ops	    = &hdlcdev_ops;
+	dev->watchdog_timeo = 10 * HZ;
+	dev->tx_queue_len   = 50;
+
+	/* generic HDLC layer callbacks and settings */
+	hdlc         = dev_to_hdlc(dev);
+	hdlc->attach = hdlcdev_attach;
+	hdlc->xmit   = hdlcdev_xmit;
+
+	/* register objects with HDLC layer */
+	rc = register_hdlc_device(dev);
+	if (rc) {
+		printk(KERN_WARNING "%s:unable to register hdlc device\n",__FILE__);
+		free_netdev(dev);
+		return rc;
+	}
+
+	info->netdev = dev;
+	return 0;
+}
+
+/**
+ * hdlcdev_exit - called by device driver when removing device instance
+ * @info: pointer to device instance information
+ *
+ * Do generic HDLC cleanup.
+ */
+static void hdlcdev_exit(struct slgt_info *info)
+{
+	if (!info->netdev)
+		return;
+	unregister_hdlc_device(info->netdev);
+	free_netdev(info->netdev);
+	info->netdev = NULL;
+}
+
+#endif /* ifdef CONFIG_HDLC */
+
+/*
+ * get async data from rx DMA buffers
+ */
+static void rx_async(struct slgt_info *info)
+{
+ 	struct mgsl_icount *icount = &info->icount;
+	unsigned int start, end;
+	unsigned char *p;
+	unsigned char status;
+	struct slgt_desc *bufs = info->rbufs;
+	int i, count;
+	int chars = 0;
+	int stat;
+	unsigned char ch;
+
+	start = end = info->rbuf_current;
+
+	while(desc_complete(bufs[end])) {
+		count = desc_count(bufs[end]) - info->rbuf_index;
+		p     = bufs[end].buf + info->rbuf_index;
+
+		DBGISR(("%s rx_async count=%d\n", info->device_name, count));
+		DBGDATA(info, p, count, "rx");
+
+		for(i=0 ; i < count; i+=2, p+=2) {
+			ch = *p;
+			icount->rx++;
+
+			stat = 0;
+
+			status = *(p + 1) & (BIT1 + BIT0);
+			if (status) {
+				if (status & BIT1)
+					icount->parity++;
+				else if (status & BIT0)
+					icount->frame++;
+				/* discard char if tty control flags say so */
+				if (status & info->ignore_status_mask)
+					continue;
+				if (status & BIT1)
+					stat = TTY_PARITY;
+				else if (status & BIT0)
+					stat = TTY_FRAME;
+			}
+			tty_insert_flip_char(&info->port, ch, stat);
+			chars++;
+		}
+
+		if (i < count) {
+			/* receive buffer not completed */
+			info->rbuf_index += i;
+			mod_timer(&info->rx_timer, jiffies + 1);
+			break;
+		}
+
+		info->rbuf_index = 0;
+		free_rbufs(info, end, end);
+
+		if (++end == info->rbuf_count)
+			end = 0;
+
+		/* if entire list searched then no frame available */
+		if (end == start)
+			break;
+	}
+
+	if (chars)
+		tty_flip_buffer_push(&info->port);
+}
+
+/*
+ * return next bottom half action to perform
+ */
+static int bh_action(struct slgt_info *info)
+{
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&info->lock,flags);
+
+	if (info->pending_bh & BH_RECEIVE) {
+		info->pending_bh &= ~BH_RECEIVE;
+		rc = BH_RECEIVE;
+	} else if (info->pending_bh & BH_TRANSMIT) {
+		info->pending_bh &= ~BH_TRANSMIT;
+		rc = BH_TRANSMIT;
+	} else if (info->pending_bh & BH_STATUS) {
+		info->pending_bh &= ~BH_STATUS;
+		rc = BH_STATUS;
+	} else {
+		/* Mark BH routine as complete */
+		info->bh_running = false;
+		info->bh_requested = false;
+		rc = 0;
+	}
+
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	return rc;
+}
+
+/*
+ * perform bottom half processing
+ */
+static void bh_handler(struct work_struct *work)
+{
+	struct slgt_info *info = container_of(work, struct slgt_info, task);
+	int action;
+
+	info->bh_running = true;
+
+	while((action = bh_action(info))) {
+		switch (action) {
+		case BH_RECEIVE:
+			DBGBH(("%s bh receive\n", info->device_name));
+			switch(info->params.mode) {
+			case MGSL_MODE_ASYNC:
+				rx_async(info);
+				break;
+			case MGSL_MODE_HDLC:
+				while(rx_get_frame(info));
+				break;
+			case MGSL_MODE_RAW:
+			case MGSL_MODE_MONOSYNC:
+			case MGSL_MODE_BISYNC:
+			case MGSL_MODE_XSYNC:
+				while(rx_get_buf(info));
+				break;
+			}
+			/* restart receiver if rx DMA buffers exhausted */
+			if (info->rx_restart)
+				rx_start(info);
+			break;
+		case BH_TRANSMIT:
+			bh_transmit(info);
+			break;
+		case BH_STATUS:
+			DBGBH(("%s bh status\n", info->device_name));
+			info->ri_chkcount = 0;
+			info->dsr_chkcount = 0;
+			info->dcd_chkcount = 0;
+			info->cts_chkcount = 0;
+			break;
+		default:
+			DBGBH(("%s unknown action\n", info->device_name));
+			break;
+		}
+	}
+	DBGBH(("%s bh_handler exit\n", info->device_name));
+}
+
+static void bh_transmit(struct slgt_info *info)
+{
+	struct tty_struct *tty = info->port.tty;
+
+	DBGBH(("%s bh_transmit\n", info->device_name));
+	if (tty)
+		tty_wakeup(tty);
+}
+
+static void dsr_change(struct slgt_info *info, unsigned short status)
+{
+	if (status & BIT3) {
+		info->signals |= SerialSignal_DSR;
+		info->input_signal_events.dsr_up++;
+	} else {
+		info->signals &= ~SerialSignal_DSR;
+		info->input_signal_events.dsr_down++;
+	}
+	DBGISR(("dsr_change %s signals=%04X\n", info->device_name, info->signals));
+	if ((info->dsr_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
+		slgt_irq_off(info, IRQ_DSR);
+		return;
+	}
+	info->icount.dsr++;
+	wake_up_interruptible(&info->status_event_wait_q);
+	wake_up_interruptible(&info->event_wait_q);
+	info->pending_bh |= BH_STATUS;
+}
+
+static void cts_change(struct slgt_info *info, unsigned short status)
+{
+	if (status & BIT2) {
+		info->signals |= SerialSignal_CTS;
+		info->input_signal_events.cts_up++;
+	} else {
+		info->signals &= ~SerialSignal_CTS;
+		info->input_signal_events.cts_down++;
+	}
+	DBGISR(("cts_change %s signals=%04X\n", info->device_name, info->signals));
+	if ((info->cts_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
+		slgt_irq_off(info, IRQ_CTS);
+		return;
+	}
+	info->icount.cts++;
+	wake_up_interruptible(&info->status_event_wait_q);
+	wake_up_interruptible(&info->event_wait_q);
+	info->pending_bh |= BH_STATUS;
+
+	if (tty_port_cts_enabled(&info->port)) {
+		if (info->port.tty) {
+			if (info->port.tty->hw_stopped) {
+				if (info->signals & SerialSignal_CTS) {
+					info->port.tty->hw_stopped = false;
+					info->pending_bh |= BH_TRANSMIT;
+					return;
+				}
+			} else {
+				if (!(info->signals & SerialSignal_CTS))
+					info->port.tty->hw_stopped = true;
+			}
+		}
+	}
+}
+
+static void dcd_change(struct slgt_info *info, unsigned short status)
+{
+	if (status & BIT1) {
+		info->signals |= SerialSignal_DCD;
+		info->input_signal_events.dcd_up++;
+	} else {
+		info->signals &= ~SerialSignal_DCD;
+		info->input_signal_events.dcd_down++;
+	}
+	DBGISR(("dcd_change %s signals=%04X\n", info->device_name, info->signals));
+	if ((info->dcd_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
+		slgt_irq_off(info, IRQ_DCD);
+		return;
+	}
+	info->icount.dcd++;
+#if SYNCLINK_GENERIC_HDLC
+	if (info->netcount) {
+		if (info->signals & SerialSignal_DCD)
+			netif_carrier_on(info->netdev);
+		else
+			netif_carrier_off(info->netdev);
+	}
+#endif
+	wake_up_interruptible(&info->status_event_wait_q);
+	wake_up_interruptible(&info->event_wait_q);
+	info->pending_bh |= BH_STATUS;
+
+	if (tty_port_check_carrier(&info->port)) {
+		if (info->signals & SerialSignal_DCD)
+			wake_up_interruptible(&info->port.open_wait);
+		else {
+			if (info->port.tty)
+				tty_hangup(info->port.tty);
+		}
+	}
+}
+
+static void ri_change(struct slgt_info *info, unsigned short status)
+{
+	if (status & BIT0) {
+		info->signals |= SerialSignal_RI;
+		info->input_signal_events.ri_up++;
+	} else {
+		info->signals &= ~SerialSignal_RI;
+		info->input_signal_events.ri_down++;
+	}
+	DBGISR(("ri_change %s signals=%04X\n", info->device_name, info->signals));
+	if ((info->ri_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
+		slgt_irq_off(info, IRQ_RI);
+		return;
+	}
+	info->icount.rng++;
+	wake_up_interruptible(&info->status_event_wait_q);
+	wake_up_interruptible(&info->event_wait_q);
+	info->pending_bh |= BH_STATUS;
+}
+
+static void isr_rxdata(struct slgt_info *info)
+{
+	unsigned int count = info->rbuf_fill_count;
+	unsigned int i = info->rbuf_fill_index;
+	unsigned short reg;
+
+	while (rd_reg16(info, SSR) & IRQ_RXDATA) {
+		reg = rd_reg16(info, RDR);
+		DBGISR(("isr_rxdata %s RDR=%04X\n", info->device_name, reg));
+		if (desc_complete(info->rbufs[i])) {
+			/* all buffers full */
+			rx_stop(info);
+			info->rx_restart = true;
+			continue;
+		}
+		info->rbufs[i].buf[count++] = (unsigned char)reg;
+		/* async mode saves status byte to buffer for each data byte */
+		if (info->params.mode == MGSL_MODE_ASYNC)
+			info->rbufs[i].buf[count++] = (unsigned char)(reg >> 8);
+		if (count == info->rbuf_fill_level || (reg & BIT10)) {
+			/* buffer full or end of frame */
+			set_desc_count(info->rbufs[i], count);
+			set_desc_status(info->rbufs[i], BIT15 | (reg >> 8));
+			info->rbuf_fill_count = count = 0;
+			if (++i == info->rbuf_count)
+				i = 0;
+			info->pending_bh |= BH_RECEIVE;
+		}
+	}
+
+	info->rbuf_fill_index = i;
+	info->rbuf_fill_count = count;
+}
+
+static void isr_serial(struct slgt_info *info)
+{
+	unsigned short status = rd_reg16(info, SSR);
+
+	DBGISR(("%s isr_serial status=%04X\n", info->device_name, status));
+
+	wr_reg16(info, SSR, status); /* clear pending */
+
+	info->irq_occurred = true;
+
+	if (info->params.mode == MGSL_MODE_ASYNC) {
+		if (status & IRQ_TXIDLE) {
+			if (info->tx_active)
+				isr_txeom(info, status);
+		}
+		if (info->rx_pio && (status & IRQ_RXDATA))
+			isr_rxdata(info);
+		if ((status & IRQ_RXBREAK) && (status & RXBREAK)) {
+			info->icount.brk++;
+			/* process break detection if tty control allows */
+			if (info->port.tty) {
+				if (!(status & info->ignore_status_mask)) {
+					if (info->read_status_mask & MASK_BREAK) {
+						tty_insert_flip_char(&info->port, 0, TTY_BREAK);
+						if (info->port.flags & ASYNC_SAK)
+							do_SAK(info->port.tty);
+					}
+				}
+			}
+		}
+	} else {
+		if (status & (IRQ_TXIDLE + IRQ_TXUNDER))
+			isr_txeom(info, status);
+		if (info->rx_pio && (status & IRQ_RXDATA))
+			isr_rxdata(info);
+		if (status & IRQ_RXIDLE) {
+			if (status & RXIDLE)
+				info->icount.rxidle++;
+			else
+				info->icount.exithunt++;
+			wake_up_interruptible(&info->event_wait_q);
+		}
+
+		if (status & IRQ_RXOVER)
+			rx_start(info);
+	}
+
+	if (status & IRQ_DSR)
+		dsr_change(info, status);
+	if (status & IRQ_CTS)
+		cts_change(info, status);
+	if (status & IRQ_DCD)
+		dcd_change(info, status);
+	if (status & IRQ_RI)
+		ri_change(info, status);
+}
+
+static void isr_rdma(struct slgt_info *info)
+{
+	unsigned int status = rd_reg32(info, RDCSR);
+
+	DBGISR(("%s isr_rdma status=%08x\n", info->device_name, status));
+
+	/* RDCSR (rx DMA control/status)
+	 *
+	 * 31..07  reserved
+	 * 06      save status byte to DMA buffer
+	 * 05      error
+	 * 04      eol (end of list)
+	 * 03      eob (end of buffer)
+	 * 02      IRQ enable
+	 * 01      reset
+	 * 00      enable
+	 */
+	wr_reg32(info, RDCSR, status);	/* clear pending */
+
+	if (status & (BIT5 + BIT4)) {
+		DBGISR(("%s isr_rdma rx_restart=1\n", info->device_name));
+		info->rx_restart = true;
+	}
+	info->pending_bh |= BH_RECEIVE;
+}
+
+static void isr_tdma(struct slgt_info *info)
+{
+	unsigned int status = rd_reg32(info, TDCSR);
+
+	DBGISR(("%s isr_tdma status=%08x\n", info->device_name, status));
+
+	/* TDCSR (tx DMA control/status)
+	 *
+	 * 31..06  reserved
+	 * 05      error
+	 * 04      eol (end of list)
+	 * 03      eob (end of buffer)
+	 * 02      IRQ enable
+	 * 01      reset
+	 * 00      enable
+	 */
+	wr_reg32(info, TDCSR, status);	/* clear pending */
+
+	if (status & (BIT5 + BIT4 + BIT3)) {
+		// another transmit buffer has completed
+		// run bottom half to get more send data from user
+		info->pending_bh |= BH_TRANSMIT;
+	}
+}
+
+/*
+ * return true if there are unsent tx DMA buffers, otherwise false
+ *
+ * if there are unsent buffers then info->tbuf_start
+ * is set to index of first unsent buffer
+ */
+static bool unsent_tbufs(struct slgt_info *info)
+{
+	unsigned int i = info->tbuf_current;
+	bool rc = false;
+
+	/*
+	 * search backwards from last loaded buffer (precedes tbuf_current)
+	 * for first unsent buffer (desc_count > 0)
+	 */
+
+	do {
+		if (i)
+			i--;
+		else
+			i = info->tbuf_count - 1;
+		if (!desc_count(info->tbufs[i]))
+			break;
+		info->tbuf_start = i;
+		rc = true;
+	} while (i != info->tbuf_current);
+
+	return rc;
+}
+
+static void isr_txeom(struct slgt_info *info, unsigned short status)
+{
+	DBGISR(("%s txeom status=%04x\n", info->device_name, status));
+
+	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
+	tdma_reset(info);
+	if (status & IRQ_TXUNDER) {
+		unsigned short val = rd_reg16(info, TCR);
+		wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
+		wr_reg16(info, TCR, val); /* clear reset bit */
+	}
+
+	if (info->tx_active) {
+		if (info->params.mode != MGSL_MODE_ASYNC) {
+			if (status & IRQ_TXUNDER)
+				info->icount.txunder++;
+			else if (status & IRQ_TXIDLE)
+				info->icount.txok++;
+		}
+
+		if (unsent_tbufs(info)) {
+			tx_start(info);
+			update_tx_timer(info);
+			return;
+		}
+		info->tx_active = false;
+
+		del_timer(&info->tx_timer);
+
+		if (info->params.mode != MGSL_MODE_ASYNC && info->drop_rts_on_tx_done) {
+			info->signals &= ~SerialSignal_RTS;
+			info->drop_rts_on_tx_done = false;
+			set_gtsignals(info);
+		}
+
+#if SYNCLINK_GENERIC_HDLC
+		if (info->netcount)
+			hdlcdev_tx_done(info);
+		else
+#endif
+		{
+			if (info->port.tty && (info->port.tty->flow.stopped || info->port.tty->hw_stopped)) {
+				tx_stop(info);
+				return;
+			}
+			info->pending_bh |= BH_TRANSMIT;
+		}
+	}
+}
+
+static void isr_gpio(struct slgt_info *info, unsigned int changed, unsigned int state)
+{
+	struct cond_wait *w, *prev;
+
+	/* wake processes waiting for specific transitions */
+	for (w = info->gpio_wait_q, prev = NULL ; w != NULL ; w = w->next) {
+		if (w->data & changed) {
+			w->data = state;
+			wake_up_interruptible(&w->q);
+			if (prev != NULL)
+				prev->next = w->next;
+			else
+				info->gpio_wait_q = w->next;
+		} else
+			prev = w;
+	}
+}
+
+/* interrupt service routine
+ *
+ * 	irq	interrupt number
+ * 	dev_id	device ID supplied during interrupt registration
+ */
+static irqreturn_t slgt_interrupt(int dummy, void *dev_id)
+{
+	struct slgt_info *info = dev_id;
+	unsigned int gsr;
+	unsigned int i;
+
+	DBGISR(("slgt_interrupt irq=%d entry\n", info->irq_level));
+
+	while((gsr = rd_reg32(info, GSR) & 0xffffff00)) {
+		DBGISR(("%s gsr=%08x\n", info->device_name, gsr));
+		info->irq_occurred = true;
+		for(i=0; i < info->port_count ; i++) {
+			if (info->port_array[i] == NULL)
+				continue;
+			spin_lock(&info->port_array[i]->lock);
+			if (gsr & (BIT8 << i))
+				isr_serial(info->port_array[i]);
+			if (gsr & (BIT16 << (i*2)))
+				isr_rdma(info->port_array[i]);
+			if (gsr & (BIT17 << (i*2)))
+				isr_tdma(info->port_array[i]);
+			spin_unlock(&info->port_array[i]->lock);
+		}
+	}
+
+	if (info->gpio_present) {
+		unsigned int state;
+		unsigned int changed;
+		spin_lock(&info->lock);
+		while ((changed = rd_reg32(info, IOSR)) != 0) {
+			DBGISR(("%s iosr=%08x\n", info->device_name, changed));
+			/* read latched state of GPIO signals */
+			state = rd_reg32(info, IOVR);
+			/* clear pending GPIO interrupt bits */
+			wr_reg32(info, IOSR, changed);
+			for (i=0 ; i < info->port_count ; i++) {
+				if (info->port_array[i] != NULL)
+					isr_gpio(info->port_array[i], changed, state);
+			}
+		}
+		spin_unlock(&info->lock);
+	}
+
+	for(i=0; i < info->port_count ; i++) {
+		struct slgt_info *port = info->port_array[i];
+		if (port == NULL)
+			continue;
+		spin_lock(&port->lock);
+		if ((port->port.count || port->netcount) &&
+		    port->pending_bh && !port->bh_running &&
+		    !port->bh_requested) {
+			DBGISR(("%s bh queued\n", port->device_name));
+			schedule_work(&port->task);
+			port->bh_requested = true;
+		}
+		spin_unlock(&port->lock);
+	}
+
+	DBGISR(("slgt_interrupt irq=%d exit\n", info->irq_level));
+	return IRQ_HANDLED;
+}
+
+static int startup(struct slgt_info *info)
+{
+	DBGINFO(("%s startup\n", info->device_name));
+
+	if (tty_port_initialized(&info->port))
+		return 0;
+
+	if (!info->tx_buf) {
+		info->tx_buf = kmalloc(info->max_frame_size, GFP_KERNEL);
+		if (!info->tx_buf) {
+			DBGERR(("%s can't allocate tx buffer\n", info->device_name));
+			return -ENOMEM;
+		}
+	}
+
+	info->pending_bh = 0;
+
+	memset(&info->icount, 0, sizeof(info->icount));
+
+	/* program hardware for current parameters */
+	change_params(info);
+
+	if (info->port.tty)
+		clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+
+	tty_port_set_initialized(&info->port, true);
+
+	return 0;
+}
+
+/*
+ *  called by close() and hangup() to shutdown hardware
+ */
+static void shutdown(struct slgt_info *info)
+{
+	unsigned long flags;
+
+	if (!tty_port_initialized(&info->port))
+		return;
+
+	DBGINFO(("%s shutdown\n", info->device_name));
+
+	/* clear status wait queue because status changes */
+	/* can't happen after shutting down the hardware */
+	wake_up_interruptible(&info->status_event_wait_q);
+	wake_up_interruptible(&info->event_wait_q);
+
+	del_timer_sync(&info->tx_timer);
+	del_timer_sync(&info->rx_timer);
+
+	kfree(info->tx_buf);
+	info->tx_buf = NULL;
+
+	spin_lock_irqsave(&info->lock,flags);
+
+	tx_stop(info);
+	rx_stop(info);
+
+	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
+
+ 	if (!info->port.tty || info->port.tty->termios.c_cflag & HUPCL) {
+		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
+		set_gtsignals(info);
+	}
+
+	flush_cond_wait(&info->gpio_wait_q);
+
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	if (info->port.tty)
+		set_bit(TTY_IO_ERROR, &info->port.tty->flags);
+
+	tty_port_set_initialized(&info->port, false);
+}
+
+static void program_hw(struct slgt_info *info)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->lock,flags);
+
+	rx_stop(info);
+	tx_stop(info);
+
+	if (info->params.mode != MGSL_MODE_ASYNC ||
+	    info->netcount)
+		sync_mode(info);
+	else
+		async_mode(info);
+
+	set_gtsignals(info);
+
+	info->dcd_chkcount = 0;
+	info->cts_chkcount = 0;
+	info->ri_chkcount = 0;
+	info->dsr_chkcount = 0;
+
+	slgt_irq_on(info, IRQ_DCD | IRQ_CTS | IRQ_DSR | IRQ_RI);
+	get_gtsignals(info);
+
+	if (info->netcount ||
+	    (info->port.tty && info->port.tty->termios.c_cflag & CREAD))
+		rx_start(info);
+
+	spin_unlock_irqrestore(&info->lock,flags);
+}
+
+/*
+ * reconfigure adapter based on new parameters
+ */
+static void change_params(struct slgt_info *info)
+{
+	unsigned cflag;
+	int bits_per_char;
+
+	if (!info->port.tty)
+		return;
+	DBGINFO(("%s change_params\n", info->device_name));
+
+	cflag = info->port.tty->termios.c_cflag;
+
+	/* if B0 rate (hangup) specified then negate RTS and DTR */
+	/* otherwise assert RTS and DTR */
+ 	if (cflag & CBAUD)
+		info->signals |= SerialSignal_RTS | SerialSignal_DTR;
+	else
+		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
+
+	/* byte size and parity */
+
+	info->params.data_bits = tty_get_char_size(cflag);
+	info->params.stop_bits = (cflag & CSTOPB) ? 2 : 1;
+
+	if (cflag & PARENB)
+		info->params.parity = (cflag & PARODD) ? ASYNC_PARITY_ODD : ASYNC_PARITY_EVEN;
+	else
+		info->params.parity = ASYNC_PARITY_NONE;
+
+	/* calculate number of jiffies to transmit a full
+	 * FIFO (32 bytes) at specified data rate
+	 */
+	bits_per_char = info->params.data_bits +
+			info->params.stop_bits + 1;
+
+	info->params.data_rate = tty_get_baud_rate(info->port.tty);
+
+	if (info->params.data_rate) {
+		info->timeout = (32*HZ*bits_per_char) /
+				info->params.data_rate;
+	}
+	info->timeout += HZ/50;		/* Add .02 seconds of slop */
+
+	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
+	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
+
+	/* process tty input control flags */
+
+	info->read_status_mask = IRQ_RXOVER;
+	if (I_INPCK(info->port.tty))
+		info->read_status_mask |= MASK_PARITY | MASK_FRAMING;
+	if (I_BRKINT(info->port.tty) || I_PARMRK(info->port.tty))
+		info->read_status_mask |= MASK_BREAK;
+	if (I_IGNPAR(info->port.tty))
+		info->ignore_status_mask |= MASK_PARITY | MASK_FRAMING;
+	if (I_IGNBRK(info->port.tty)) {
+		info->ignore_status_mask |= MASK_BREAK;
+		/* If ignoring parity and break indicators, ignore
+		 * overruns too.  (For real raw support).
+		 */
+		if (I_IGNPAR(info->port.tty))
+			info->ignore_status_mask |= MASK_OVERRUN;
+	}
+
+	program_hw(info);
+}
+
+static int get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount)
+{
+	DBGINFO(("%s get_stats\n",  info->device_name));
+	if (!user_icount) {
+		memset(&info->icount, 0, sizeof(info->icount));
+	} else {
+		if (copy_to_user(user_icount, &info->icount, sizeof(struct mgsl_icount)))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+static int get_params(struct slgt_info *info, MGSL_PARAMS __user *user_params)
+{
+	DBGINFO(("%s get_params\n", info->device_name));
+	if (copy_to_user(user_params, &info->params, sizeof(MGSL_PARAMS)))
+		return -EFAULT;
+	return 0;
+}
+
+static int set_params(struct slgt_info *info, MGSL_PARAMS __user *new_params)
+{
+ 	unsigned long flags;
+	MGSL_PARAMS tmp_params;
+
+	DBGINFO(("%s set_params\n", info->device_name));
+	if (copy_from_user(&tmp_params, new_params, sizeof(MGSL_PARAMS)))
+		return -EFAULT;
+
+	spin_lock_irqsave(&info->lock, flags);
+	if (tmp_params.mode == MGSL_MODE_BASE_CLOCK)
+		info->base_clock = tmp_params.clock_speed;
+	else
+		memcpy(&info->params, &tmp_params, sizeof(MGSL_PARAMS));
+	spin_unlock_irqrestore(&info->lock, flags);
+
+	program_hw(info);
+
+	return 0;
+}
+
+static int get_txidle(struct slgt_info *info, int __user *idle_mode)
+{
+	DBGINFO(("%s get_txidle=%d\n", info->device_name, info->idle_mode));
+	if (put_user(info->idle_mode, idle_mode))
+		return -EFAULT;
+	return 0;
+}
+
+static int set_txidle(struct slgt_info *info, int idle_mode)
+{
+ 	unsigned long flags;
+	DBGINFO(("%s set_txidle(%d)\n", info->device_name, idle_mode));
+	spin_lock_irqsave(&info->lock,flags);
+	info->idle_mode = idle_mode;
+	if (info->params.mode != MGSL_MODE_ASYNC)
+		tx_set_idle(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+static int tx_enable(struct slgt_info *info, int enable)
+{
+ 	unsigned long flags;
+	DBGINFO(("%s tx_enable(%d)\n", info->device_name, enable));
+	spin_lock_irqsave(&info->lock,flags);
+	if (enable) {
+		if (!info->tx_enabled)
+			tx_start(info);
+	} else {
+		if (info->tx_enabled)
+			tx_stop(info);
+	}
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+/*
+ * abort transmit HDLC frame
+ */
+static int tx_abort(struct slgt_info *info)
+{
+ 	unsigned long flags;
+	DBGINFO(("%s tx_abort\n", info->device_name));
+	spin_lock_irqsave(&info->lock,flags);
+	tdma_reset(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+static int rx_enable(struct slgt_info *info, int enable)
+{
+ 	unsigned long flags;
+	unsigned int rbuf_fill_level;
+	DBGINFO(("%s rx_enable(%08x)\n", info->device_name, enable));
+	spin_lock_irqsave(&info->lock,flags);
+	/*
+	 * enable[31..16] = receive DMA buffer fill level
+	 * 0 = noop (leave fill level unchanged)
+	 * fill level must be multiple of 4 and <= buffer size
+	 */
+	rbuf_fill_level = ((unsigned int)enable) >> 16;
+	if (rbuf_fill_level) {
+		if ((rbuf_fill_level > DMABUFSIZE) || (rbuf_fill_level % 4)) {
+			spin_unlock_irqrestore(&info->lock, flags);
+			return -EINVAL;
+		}
+		info->rbuf_fill_level = rbuf_fill_level;
+		if (rbuf_fill_level < 128)
+			info->rx_pio = 1; /* PIO mode */
+		else
+			info->rx_pio = 0; /* DMA mode */
+		rx_stop(info); /* restart receiver to use new fill level */
+	}
+
+	/*
+	 * enable[1..0] = receiver enable command
+	 * 0 = disable
+	 * 1 = enable
+	 * 2 = enable or force hunt mode if already enabled
+	 */
+	enable &= 3;
+	if (enable) {
+		if (!info->rx_enabled)
+			rx_start(info);
+		else if (enable == 2) {
+			/* force hunt mode (write 1 to RCR[3]) */
+			wr_reg16(info, RCR, rd_reg16(info, RCR) | BIT3);
+		}
+	} else {
+		if (info->rx_enabled)
+			rx_stop(info);
+	}
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+/*
+ *  wait for specified event to occur
+ */
+static int wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr)
+{
+ 	unsigned long flags;
+	int s;
+	int rc=0;
+	struct mgsl_icount cprev, cnow;
+	int events;
+	int mask;
+	struct	_input_signal_events oldsigs, newsigs;
+	DECLARE_WAITQUEUE(wait, current);
+
+	if (get_user(mask, mask_ptr))
+		return -EFAULT;
+
+	DBGINFO(("%s wait_mgsl_event(%d)\n", info->device_name, mask));
+
+	spin_lock_irqsave(&info->lock,flags);
+
+	/* return immediately if state matches requested events */
+	get_gtsignals(info);
+	s = info->signals;
+
+	events = mask &
+		( ((s & SerialSignal_DSR) ? MgslEvent_DsrActive:MgslEvent_DsrInactive) +
+ 		  ((s & SerialSignal_DCD) ? MgslEvent_DcdActive:MgslEvent_DcdInactive) +
+		  ((s & SerialSignal_CTS) ? MgslEvent_CtsActive:MgslEvent_CtsInactive) +
+		  ((s & SerialSignal_RI)  ? MgslEvent_RiActive :MgslEvent_RiInactive) );
+	if (events) {
+		spin_unlock_irqrestore(&info->lock,flags);
+		goto exit;
+	}
+
+	/* save current irq counts */
+	cprev = info->icount;
+	oldsigs = info->input_signal_events;
+
+	/* enable hunt and idle irqs if needed */
+	if (mask & (MgslEvent_ExitHuntMode+MgslEvent_IdleReceived)) {
+		unsigned short val = rd_reg16(info, SCR);
+		if (!(val & IRQ_RXIDLE))
+			wr_reg16(info, SCR, (unsigned short)(val | IRQ_RXIDLE));
+	}
+
+	set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&info->event_wait_q, &wait);
+
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	for(;;) {
+		schedule();
+		if (signal_pending(current)) {
+			rc = -ERESTARTSYS;
+			break;
+		}
+
+		/* get current irq counts */
+		spin_lock_irqsave(&info->lock,flags);
+		cnow = info->icount;
+		newsigs = info->input_signal_events;
+		set_current_state(TASK_INTERRUPTIBLE);
+		spin_unlock_irqrestore(&info->lock,flags);
+
+		/* if no change, wait aborted for some reason */
+		if (newsigs.dsr_up   == oldsigs.dsr_up   &&
+		    newsigs.dsr_down == oldsigs.dsr_down &&
+		    newsigs.dcd_up   == oldsigs.dcd_up   &&
+		    newsigs.dcd_down == oldsigs.dcd_down &&
+		    newsigs.cts_up   == oldsigs.cts_up   &&
+		    newsigs.cts_down == oldsigs.cts_down &&
+		    newsigs.ri_up    == oldsigs.ri_up    &&
+		    newsigs.ri_down  == oldsigs.ri_down  &&
+		    cnow.exithunt    == cprev.exithunt   &&
+		    cnow.rxidle      == cprev.rxidle) {
+			rc = -EIO;
+			break;
+		}
+
+		events = mask &
+			( (newsigs.dsr_up   != oldsigs.dsr_up   ? MgslEvent_DsrActive:0)   +
+			  (newsigs.dsr_down != oldsigs.dsr_down ? MgslEvent_DsrInactive:0) +
+			  (newsigs.dcd_up   != oldsigs.dcd_up   ? MgslEvent_DcdActive:0)   +
+			  (newsigs.dcd_down != oldsigs.dcd_down ? MgslEvent_DcdInactive:0) +
+			  (newsigs.cts_up   != oldsigs.cts_up   ? MgslEvent_CtsActive:0)   +
+			  (newsigs.cts_down != oldsigs.cts_down ? MgslEvent_CtsInactive:0) +
+			  (newsigs.ri_up    != oldsigs.ri_up    ? MgslEvent_RiActive:0)    +
+			  (newsigs.ri_down  != oldsigs.ri_down  ? MgslEvent_RiInactive:0)  +
+			  (cnow.exithunt    != cprev.exithunt   ? MgslEvent_ExitHuntMode:0) +
+			  (cnow.rxidle      != cprev.rxidle     ? MgslEvent_IdleReceived:0) );
+		if (events)
+			break;
+
+		cprev = cnow;
+		oldsigs = newsigs;
+	}
+
+	remove_wait_queue(&info->event_wait_q, &wait);
+	set_current_state(TASK_RUNNING);
+
+
+	if (mask & (MgslEvent_ExitHuntMode + MgslEvent_IdleReceived)) {
+		spin_lock_irqsave(&info->lock,flags);
+		if (!waitqueue_active(&info->event_wait_q)) {
+			/* disable enable exit hunt mode/idle rcvd IRQs */
+			wr_reg16(info, SCR,
+				(unsigned short)(rd_reg16(info, SCR) & ~IRQ_RXIDLE));
+		}
+		spin_unlock_irqrestore(&info->lock,flags);
+	}
+exit:
+	if (rc == 0)
+		rc = put_user(events, mask_ptr);
+	return rc;
+}
+
+static int get_interface(struct slgt_info *info, int __user *if_mode)
+{
+	DBGINFO(("%s get_interface=%x\n", info->device_name, info->if_mode));
+	if (put_user(info->if_mode, if_mode))
+		return -EFAULT;
+	return 0;
+}
+
+static int set_interface(struct slgt_info *info, int if_mode)
+{
+ 	unsigned long flags;
+	unsigned short val;
+
+	DBGINFO(("%s set_interface=%x)\n", info->device_name, if_mode));
+	spin_lock_irqsave(&info->lock,flags);
+	info->if_mode = if_mode;
+
+	msc_set_vcr(info);
+
+	/* TCR (tx control) 07  1=RTS driver control */
+	val = rd_reg16(info, TCR);
+	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
+		val |= BIT7;
+	else
+		val &= ~BIT7;
+	wr_reg16(info, TCR, val);
+
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+static int get_xsync(struct slgt_info *info, int __user *xsync)
+{
+	DBGINFO(("%s get_xsync=%x\n", info->device_name, info->xsync));
+	if (put_user(info->xsync, xsync))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * set extended sync pattern (1 to 4 bytes) for extended sync mode
+ *
+ * sync pattern is contained in least significant bytes of value
+ * most significant byte of sync pattern is oldest (1st sent/detected)
+ */
+static int set_xsync(struct slgt_info *info, int xsync)
+{
+	unsigned long flags;
+
+	DBGINFO(("%s set_xsync=%x)\n", info->device_name, xsync));
+	spin_lock_irqsave(&info->lock, flags);
+	info->xsync = xsync;
+	wr_reg32(info, XSR, xsync);
+	spin_unlock_irqrestore(&info->lock, flags);
+	return 0;
+}
+
+static int get_xctrl(struct slgt_info *info, int __user *xctrl)
+{
+	DBGINFO(("%s get_xctrl=%x\n", info->device_name, info->xctrl));
+	if (put_user(info->xctrl, xctrl))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * set extended control options
+ *
+ * xctrl[31:19] reserved, must be zero
+ * xctrl[18:17] extended sync pattern length in bytes
+ *              00 = 1 byte  in xsr[7:0]
+ *              01 = 2 bytes in xsr[15:0]
+ *              10 = 3 bytes in xsr[23:0]
+ *              11 = 4 bytes in xsr[31:0]
+ * xctrl[16]    1 = enable terminal count, 0=disabled
+ * xctrl[15:0]  receive terminal count for fixed length packets
+ *              value is count minus one (0 = 1 byte packet)
+ *              when terminal count is reached, receiver
+ *              automatically returns to hunt mode and receive
+ *              FIFO contents are flushed to DMA buffers with
+ *              end of frame (EOF) status
+ */
+static int set_xctrl(struct slgt_info *info, int xctrl)
+{
+	unsigned long flags;
+
+	DBGINFO(("%s set_xctrl=%x)\n", info->device_name, xctrl));
+	spin_lock_irqsave(&info->lock, flags);
+	info->xctrl = xctrl;
+	wr_reg32(info, XCR, xctrl);
+	spin_unlock_irqrestore(&info->lock, flags);
+	return 0;
+}
+
+/*
+ * set general purpose IO pin state and direction
+ *
+ * user_gpio fields:
+ * state   each bit indicates a pin state
+ * smask   set bit indicates pin state to set
+ * dir     each bit indicates a pin direction (0=input, 1=output)
+ * dmask   set bit indicates pin direction to set
+ */
+static int set_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
+{
+ 	unsigned long flags;
+	struct gpio_desc gpio;
+	__u32 data;
+
+	if (!info->gpio_present)
+		return -EINVAL;
+	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
+		return -EFAULT;
+	DBGINFO(("%s set_gpio state=%08x smask=%08x dir=%08x dmask=%08x\n",
+		 info->device_name, gpio.state, gpio.smask,
+		 gpio.dir, gpio.dmask));
+
+	spin_lock_irqsave(&info->port_array[0]->lock, flags);
+	if (gpio.dmask) {
+		data = rd_reg32(info, IODR);
+		data |= gpio.dmask & gpio.dir;
+		data &= ~(gpio.dmask & ~gpio.dir);
+		wr_reg32(info, IODR, data);
+	}
+	if (gpio.smask) {
+		data = rd_reg32(info, IOVR);
+		data |= gpio.smask & gpio.state;
+		data &= ~(gpio.smask & ~gpio.state);
+		wr_reg32(info, IOVR, data);
+	}
+	spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
+
+	return 0;
+}
+
+/*
+ * get general purpose IO pin state and direction
+ */
+static int get_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
+{
+	struct gpio_desc gpio;
+	if (!info->gpio_present)
+		return -EINVAL;
+	gpio.state = rd_reg32(info, IOVR);
+	gpio.smask = 0xffffffff;
+	gpio.dir   = rd_reg32(info, IODR);
+	gpio.dmask = 0xffffffff;
+	if (copy_to_user(user_gpio, &gpio, sizeof(gpio)))
+		return -EFAULT;
+	DBGINFO(("%s get_gpio state=%08x dir=%08x\n",
+		 info->device_name, gpio.state, gpio.dir));
+	return 0;
+}
+
+/*
+ * conditional wait facility
+ */
+static void init_cond_wait(struct cond_wait *w, unsigned int data)
+{
+	init_waitqueue_head(&w->q);
+	init_waitqueue_entry(&w->wait, current);
+	w->data = data;
+}
+
+static void add_cond_wait(struct cond_wait **head, struct cond_wait *w)
+{
+	set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&w->q, &w->wait);
+	w->next = *head;
+	*head = w;
+}
+
+static void remove_cond_wait(struct cond_wait **head, struct cond_wait *cw)
+{
+	struct cond_wait *w, *prev;
+	remove_wait_queue(&cw->q, &cw->wait);
+	set_current_state(TASK_RUNNING);
+	for (w = *head, prev = NULL ; w != NULL ; prev = w, w = w->next) {
+		if (w == cw) {
+			if (prev != NULL)
+				prev->next = w->next;
+			else
+				*head = w->next;
+			break;
+		}
+	}
+}
+
+static void flush_cond_wait(struct cond_wait **head)
+{
+	while (*head != NULL) {
+		wake_up_interruptible(&(*head)->q);
+		*head = (*head)->next;
+	}
+}
+
+/*
+ * wait for general purpose I/O pin(s) to enter specified state
+ *
+ * user_gpio fields:
+ * state - bit indicates target pin state
+ * smask - set bit indicates watched pin
+ *
+ * The wait ends when at least one watched pin enters the specified
+ * state. When 0 (no error) is returned, user_gpio->state is set to the
+ * state of all GPIO pins when the wait ends.
+ *
+ * Note: Each pin may be a dedicated input, dedicated output, or
+ * configurable input/output. The number and configuration of pins
+ * varies with the specific adapter model. Only input pins (dedicated
+ * or configured) can be monitored with this function.
+ */
+static int wait_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
+{
+ 	unsigned long flags;
+	int rc = 0;
+	struct gpio_desc gpio;
+	struct cond_wait wait;
+	u32 state;
+
+	if (!info->gpio_present)
+		return -EINVAL;
+	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
+		return -EFAULT;
+	DBGINFO(("%s wait_gpio() state=%08x smask=%08x\n",
+		 info->device_name, gpio.state, gpio.smask));
+	/* ignore output pins identified by set IODR bit */
+	if ((gpio.smask &= ~rd_reg32(info, IODR)) == 0)
+		return -EINVAL;
+	init_cond_wait(&wait, gpio.smask);
+
+	spin_lock_irqsave(&info->port_array[0]->lock, flags);
+	/* enable interrupts for watched pins */
+	wr_reg32(info, IOER, rd_reg32(info, IOER) | gpio.smask);
+	/* get current pin states */
+	state = rd_reg32(info, IOVR);
+
+	if (gpio.smask & ~(state ^ gpio.state)) {
+		/* already in target state */
+		gpio.state = state;
+	} else {
+		/* wait for target state */
+		add_cond_wait(&info->gpio_wait_q, &wait);
+		spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
+		schedule();
+		if (signal_pending(current))
+			rc = -ERESTARTSYS;
+		else
+			gpio.state = wait.data;
+		spin_lock_irqsave(&info->port_array[0]->lock, flags);
+		remove_cond_wait(&info->gpio_wait_q, &wait);
+	}
+
+	/* disable all GPIO interrupts if no waiting processes */
+	if (info->gpio_wait_q == NULL)
+		wr_reg32(info, IOER, 0);
+	spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
+
+	if ((rc == 0) && copy_to_user(user_gpio, &gpio, sizeof(gpio)))
+		rc = -EFAULT;
+	return rc;
+}
+
+static int modem_input_wait(struct slgt_info *info,int arg)
+{
+ 	unsigned long flags;
+	int rc;
+	struct mgsl_icount cprev, cnow;
+	DECLARE_WAITQUEUE(wait, current);
+
+	/* save current irq counts */
+	spin_lock_irqsave(&info->lock,flags);
+	cprev = info->icount;
+	add_wait_queue(&info->status_event_wait_q, &wait);
+	set_current_state(TASK_INTERRUPTIBLE);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	for(;;) {
+		schedule();
+		if (signal_pending(current)) {
+			rc = -ERESTARTSYS;
+			break;
+		}
+
+		/* get new irq counts */
+		spin_lock_irqsave(&info->lock,flags);
+		cnow = info->icount;
+		set_current_state(TASK_INTERRUPTIBLE);
+		spin_unlock_irqrestore(&info->lock,flags);
+
+		/* if no change, wait aborted for some reason */
+		if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
+		    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
+			rc = -EIO;
+			break;
+		}
+
+		/* check for change in caller specified modem input */
+		if ((arg & TIOCM_RNG && cnow.rng != cprev.rng) ||
+		    (arg & TIOCM_DSR && cnow.dsr != cprev.dsr) ||
+		    (arg & TIOCM_CD  && cnow.dcd != cprev.dcd) ||
+		    (arg & TIOCM_CTS && cnow.cts != cprev.cts)) {
+			rc = 0;
+			break;
+		}
+
+		cprev = cnow;
+	}
+	remove_wait_queue(&info->status_event_wait_q, &wait);
+	set_current_state(TASK_RUNNING);
+	return rc;
+}
+
+/*
+ *  return state of serial control and status signals
+ */
+static int tiocmget(struct tty_struct *tty)
+{
+	struct slgt_info *info = tty->driver_data;
+	unsigned int result;
+ 	unsigned long flags;
+
+	spin_lock_irqsave(&info->lock,flags);
+ 	get_gtsignals(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	result = ((info->signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
+		((info->signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
+		((info->signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
+		((info->signals & SerialSignal_RI)  ? TIOCM_RNG:0) +
+		((info->signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
+		((info->signals & SerialSignal_CTS) ? TIOCM_CTS:0);
+
+	DBGINFO(("%s tiocmget value=%08X\n", info->device_name, result));
+	return result;
+}
+
+/*
+ * set modem control signals (DTR/RTS)
+ *
+ * 	cmd	signal command: TIOCMBIS = set bit TIOCMBIC = clear bit
+ *		TIOCMSET = set/clear signal values
+ * 	value	bit mask for command
+ */
+static int tiocmset(struct tty_struct *tty,
+		    unsigned int set, unsigned int clear)
+{
+	struct slgt_info *info = tty->driver_data;
+ 	unsigned long flags;
+
+	DBGINFO(("%s tiocmset(%x,%x)\n", info->device_name, set, clear));
+
+	if (set & TIOCM_RTS)
+		info->signals |= SerialSignal_RTS;
+	if (set & TIOCM_DTR)
+		info->signals |= SerialSignal_DTR;
+	if (clear & TIOCM_RTS)
+		info->signals &= ~SerialSignal_RTS;
+	if (clear & TIOCM_DTR)
+		info->signals &= ~SerialSignal_DTR;
+
+	spin_lock_irqsave(&info->lock,flags);
+	set_gtsignals(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+	return 0;
+}
+
+static bool carrier_raised(struct tty_port *port)
+{
+	unsigned long flags;
+	struct slgt_info *info = container_of(port, struct slgt_info, port);
+
+	spin_lock_irqsave(&info->lock,flags);
+	get_gtsignals(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	return info->signals & SerialSignal_DCD;
+}
+
+static void dtr_rts(struct tty_port *port, bool active)
+{
+	unsigned long flags;
+	struct slgt_info *info = container_of(port, struct slgt_info, port);
+
+	spin_lock_irqsave(&info->lock,flags);
+	if (active)
+		info->signals |= SerialSignal_RTS | SerialSignal_DTR;
+	else
+		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
+	set_gtsignals(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+}
+
+
+/*
+ *  block current process until the device is ready to open
+ */
+static int block_til_ready(struct tty_struct *tty, struct file *filp,
+			   struct slgt_info *info)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	int		retval;
+	bool		do_clocal = false;
+	unsigned long	flags;
+	bool		cd;
+	struct tty_port *port = &info->port;
+
+	DBGINFO(("%s block_til_ready\n", tty->driver->name));
+
+	if (filp->f_flags & O_NONBLOCK || tty_io_error(tty)) {
+		/* nonblock mode is set or port is not enabled */
+		tty_port_set_active(port, true);
+		return 0;
+	}
+
+	if (C_CLOCAL(tty))
+		do_clocal = true;
+
+	/* Wait for carrier detect and the line to become
+	 * free (i.e., not in use by the callout).  While we are in
+	 * this loop, port->count is dropped by one, so that
+	 * close() knows when to free things.  We restore it upon
+	 * exit, either normal or abnormal.
+	 */
+
+	retval = 0;
+	add_wait_queue(&port->open_wait, &wait);
+
+	spin_lock_irqsave(&info->lock, flags);
+	port->count--;
+	spin_unlock_irqrestore(&info->lock, flags);
+	port->blocked_open++;
+
+	while (1) {
+		if (C_BAUD(tty) && tty_port_initialized(port))
+			tty_port_raise_dtr_rts(port);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
+			retval = (port->flags & ASYNC_HUP_NOTIFY) ?
+					-EAGAIN : -ERESTARTSYS;
+			break;
+		}
+
+		cd = tty_port_carrier_raised(port);
+		if (do_clocal || cd)
+			break;
+
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+
+		DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
+		tty_unlock(tty);
+		schedule();
+		tty_lock(tty);
+	}
+
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&port->open_wait, &wait);
+
+	if (!tty_hung_up_p(filp))
+		port->count++;
+	port->blocked_open--;
+
+	if (!retval)
+		tty_port_set_active(port, true);
+
+	DBGINFO(("%s block_til_ready ready, rc=%d\n", tty->driver->name, retval));
+	return retval;
+}
+
+/*
+ * allocate buffers used for calling line discipline receive_buf
+ * directly in synchronous mode
+ * note: add 5 bytes to max frame size to allow appending
+ * 32-bit CRC and status byte when configured to do so
+ */
+static int alloc_tmp_rbuf(struct slgt_info *info)
+{
+	info->tmp_rbuf = kmalloc(info->max_frame_size + 5, GFP_KERNEL);
+	if (info->tmp_rbuf == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void free_tmp_rbuf(struct slgt_info *info)
+{
+	kfree(info->tmp_rbuf);
+	info->tmp_rbuf = NULL;
+}
+
+/*
+ * allocate DMA descriptor lists.
+ */
+static int alloc_desc(struct slgt_info *info)
+{
+	unsigned int i;
+	unsigned int pbufs;
+
+	/* allocate memory to hold descriptor lists */
+	info->bufs = dma_alloc_coherent(&info->pdev->dev, DESC_LIST_SIZE,
+					&info->bufs_dma_addr, GFP_KERNEL);
+	if (info->bufs == NULL)
+		return -ENOMEM;
+
+	info->rbufs = (struct slgt_desc*)info->bufs;
+	info->tbufs = ((struct slgt_desc*)info->bufs) + info->rbuf_count;
+
+	pbufs = (unsigned int)info->bufs_dma_addr;
+
+	/*
+	 * Build circular lists of descriptors
+	 */
+
+	for (i=0; i < info->rbuf_count; i++) {
+		/* physical address of this descriptor */
+		info->rbufs[i].pdesc = pbufs + (i * sizeof(struct slgt_desc));
+
+		/* physical address of next descriptor */
+		if (i == info->rbuf_count - 1)
+			info->rbufs[i].next = cpu_to_le32(pbufs);
+		else
+			info->rbufs[i].next = cpu_to_le32(pbufs + ((i+1) * sizeof(struct slgt_desc)));
+		set_desc_count(info->rbufs[i], DMABUFSIZE);
+	}
+
+	for (i=0; i < info->tbuf_count; i++) {
+		/* physical address of this descriptor */
+		info->tbufs[i].pdesc = pbufs + ((info->rbuf_count + i) * sizeof(struct slgt_desc));
+
+		/* physical address of next descriptor */
+		if (i == info->tbuf_count - 1)
+			info->tbufs[i].next = cpu_to_le32(pbufs + info->rbuf_count * sizeof(struct slgt_desc));
+		else
+			info->tbufs[i].next = cpu_to_le32(pbufs + ((info->rbuf_count + i + 1) * sizeof(struct slgt_desc)));
+	}
+
+	return 0;
+}
+
+static void free_desc(struct slgt_info *info)
+{
+	if (info->bufs != NULL) {
+		dma_free_coherent(&info->pdev->dev, DESC_LIST_SIZE,
+				  info->bufs, info->bufs_dma_addr);
+		info->bufs  = NULL;
+		info->rbufs = NULL;
+		info->tbufs = NULL;
+	}
+}
+
+static int alloc_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
+{
+	int i;
+	for (i=0; i < count; i++) {
+		bufs[i].buf = dma_alloc_coherent(&info->pdev->dev, DMABUFSIZE,
+						 &bufs[i].buf_dma_addr, GFP_KERNEL);
+		if (!bufs[i].buf)
+			return -ENOMEM;
+		bufs[i].pbuf  = cpu_to_le32((unsigned int)bufs[i].buf_dma_addr);
+	}
+	return 0;
+}
+
+static void free_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
+{
+	int i;
+	for (i=0; i < count; i++) {
+		if (bufs[i].buf == NULL)
+			continue;
+		dma_free_coherent(&info->pdev->dev, DMABUFSIZE, bufs[i].buf,
+				  bufs[i].buf_dma_addr);
+		bufs[i].buf = NULL;
+	}
+}
+
+static int alloc_dma_bufs(struct slgt_info *info)
+{
+	info->rbuf_count = 32;
+	info->tbuf_count = 32;
+
+	if (alloc_desc(info) < 0 ||
+	    alloc_bufs(info, info->rbufs, info->rbuf_count) < 0 ||
+	    alloc_bufs(info, info->tbufs, info->tbuf_count) < 0 ||
+	    alloc_tmp_rbuf(info) < 0) {
+		DBGERR(("%s DMA buffer alloc fail\n", info->device_name));
+		return -ENOMEM;
+	}
+	reset_rbufs(info);
+	return 0;
+}
+
+static void free_dma_bufs(struct slgt_info *info)
+{
+	if (info->bufs) {
+		free_bufs(info, info->rbufs, info->rbuf_count);
+		free_bufs(info, info->tbufs, info->tbuf_count);
+		free_desc(info);
+	}
+	free_tmp_rbuf(info);
+}
+
+static int claim_resources(struct slgt_info *info)
+{
+	if (request_mem_region(info->phys_reg_addr, SLGT_REG_SIZE, "synclink_gt") == NULL) {
+		DBGERR(("%s reg addr conflict, addr=%08X\n",
+			info->device_name, info->phys_reg_addr));
+		info->init_error = DiagStatus_AddressConflict;
+		goto errout;
+	}
+	else
+		info->reg_addr_requested = true;
+
+	info->reg_addr = ioremap(info->phys_reg_addr, SLGT_REG_SIZE);
+	if (!info->reg_addr) {
+		DBGERR(("%s can't map device registers, addr=%08X\n",
+			info->device_name, info->phys_reg_addr));
+		info->init_error = DiagStatus_CantAssignPciResources;
+		goto errout;
+	}
+	return 0;
+
+errout:
+	release_resources(info);
+	return -ENODEV;
+}
+
+static void release_resources(struct slgt_info *info)
+{
+	if (info->irq_requested) {
+		free_irq(info->irq_level, info);
+		info->irq_requested = false;
+	}
+
+	if (info->reg_addr_requested) {
+		release_mem_region(info->phys_reg_addr, SLGT_REG_SIZE);
+		info->reg_addr_requested = false;
+	}
+
+	if (info->reg_addr) {
+		iounmap(info->reg_addr);
+		info->reg_addr = NULL;
+	}
+}
+
+/* Add the specified device instance data structure to the
+ * global linked list of devices and increment the device count.
+ */
+static void add_device(struct slgt_info *info)
+{
+	char *devstr;
+
+	info->next_device = NULL;
+	info->line = slgt_device_count;
+	sprintf(info->device_name, "%s%d", tty_dev_prefix, info->line);
+
+	if (info->line < MAX_DEVICES) {
+		if (maxframe[info->line])
+			info->max_frame_size = maxframe[info->line];
+	}
+
+	slgt_device_count++;
+
+	if (!slgt_device_list)
+		slgt_device_list = info;
+	else {
+		struct slgt_info *current_dev = slgt_device_list;
+		while(current_dev->next_device)
+			current_dev = current_dev->next_device;
+		current_dev->next_device = info;
+	}
+
+	if (info->max_frame_size < 4096)
+		info->max_frame_size = 4096;
+	else if (info->max_frame_size > 65535)
+		info->max_frame_size = 65535;
+
+	switch(info->pdev->device) {
+	case SYNCLINK_GT_DEVICE_ID:
+		devstr = "GT";
+		break;
+	case SYNCLINK_GT2_DEVICE_ID:
+		devstr = "GT2";
+		break;
+	case SYNCLINK_GT4_DEVICE_ID:
+		devstr = "GT4";
+		break;
+	case SYNCLINK_AC_DEVICE_ID:
+		devstr = "AC";
+		info->params.mode = MGSL_MODE_ASYNC;
+		break;
+	default:
+		devstr = "(unknown model)";
+	}
+	printk("SyncLink %s %s IO=%08x IRQ=%d MaxFrameSize=%u\n",
+		devstr, info->device_name, info->phys_reg_addr,
+		info->irq_level, info->max_frame_size);
+
+#if SYNCLINK_GENERIC_HDLC
+	hdlcdev_init(info);
+#endif
+}
+
+static const struct tty_port_operations slgt_port_ops = {
+	.carrier_raised = carrier_raised,
+	.dtr_rts = dtr_rts,
+};
+
+/*
+ *  allocate device instance structure, return NULL on failure
+ */
+static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev *pdev)
+{
+	struct slgt_info *info;
+
+	info = kzalloc(sizeof(struct slgt_info), GFP_KERNEL);
+
+	if (!info) {
+		DBGERR(("%s device alloc failed adapter=%d port=%d\n",
+			driver_name, adapter_num, port_num));
+	} else {
+		tty_port_init(&info->port);
+		info->port.ops = &slgt_port_ops;
+		INIT_WORK(&info->task, bh_handler);
+		info->max_frame_size = 4096;
+		info->base_clock = 14745600;
+		info->rbuf_fill_level = DMABUFSIZE;
+		init_waitqueue_head(&info->status_event_wait_q);
+		init_waitqueue_head(&info->event_wait_q);
+		spin_lock_init(&info->netlock);
+		memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
+		info->idle_mode = HDLC_TXIDLE_FLAGS;
+		info->adapter_num = adapter_num;
+		info->port_num = port_num;
+
+		timer_setup(&info->tx_timer, tx_timeout, 0);
+		timer_setup(&info->rx_timer, rx_timeout, 0);
+
+		/* Copy configuration info to device instance data */
+		info->pdev = pdev;
+		info->irq_level = pdev->irq;
+		info->phys_reg_addr = pci_resource_start(pdev,0);
+
+		info->bus_type = MGSL_BUS_TYPE_PCI;
+		info->irq_flags = IRQF_SHARED;
+
+		info->init_error = -1; /* assume error, set to 0 on successful init */
+	}
+
+	return info;
+}
+
+static void device_init(int adapter_num, struct pci_dev *pdev)
+{
+	struct slgt_info *port_array[SLGT_MAX_PORTS];
+	int i;
+	int port_count = 1;
+
+	if (pdev->device == SYNCLINK_GT2_DEVICE_ID)
+		port_count = 2;
+	else if (pdev->device == SYNCLINK_GT4_DEVICE_ID)
+		port_count = 4;
+
+	/* allocate device instances for all ports */
+	for (i=0; i < port_count; ++i) {
+		port_array[i] = alloc_dev(adapter_num, i, pdev);
+		if (port_array[i] == NULL) {
+			for (--i; i >= 0; --i) {
+				tty_port_destroy(&port_array[i]->port);
+				kfree(port_array[i]);
+			}
+			return;
+		}
+	}
+
+	/* give copy of port_array to all ports and add to device list  */
+	for (i=0; i < port_count; ++i) {
+		memcpy(port_array[i]->port_array, port_array, sizeof(port_array));
+		add_device(port_array[i]);
+		port_array[i]->port_count = port_count;
+		spin_lock_init(&port_array[i]->lock);
+	}
+
+	/* Allocate and claim adapter resources */
+	if (!claim_resources(port_array[0])) {
+
+		alloc_dma_bufs(port_array[0]);
+
+		/* copy resource information from first port to others */
+		for (i = 1; i < port_count; ++i) {
+			port_array[i]->irq_level = port_array[0]->irq_level;
+			port_array[i]->reg_addr  = port_array[0]->reg_addr;
+			alloc_dma_bufs(port_array[i]);
+		}
+
+		if (request_irq(port_array[0]->irq_level,
+					slgt_interrupt,
+					port_array[0]->irq_flags,
+					port_array[0]->device_name,
+					port_array[0]) < 0) {
+			DBGERR(("%s request_irq failed IRQ=%d\n",
+				port_array[0]->device_name,
+				port_array[0]->irq_level));
+		} else {
+			port_array[0]->irq_requested = true;
+			adapter_test(port_array[0]);
+			for (i=1 ; i < port_count ; i++) {
+				port_array[i]->init_error = port_array[0]->init_error;
+				port_array[i]->gpio_present = port_array[0]->gpio_present;
+			}
+		}
+	}
+
+	for (i = 0; i < port_count; ++i) {
+		struct slgt_info *info = port_array[i];
+		tty_port_register_device(&info->port, serial_driver, info->line,
+				&info->pdev->dev);
+	}
+}
+
+static int init_one(struct pci_dev *dev,
+			      const struct pci_device_id *ent)
+{
+	if (pci_enable_device(dev)) {
+		printk("error enabling pci device %p\n", dev);
+		return -EIO;
+	}
+	pci_set_master(dev);
+	device_init(slgt_device_count, dev);
+	return 0;
+}
+
+static void remove_one(struct pci_dev *dev)
+{
+}
+
+static const struct tty_operations ops = {
+	.open = open,
+	.close = close,
+	.write = write,
+	.put_char = put_char,
+	.flush_chars = flush_chars,
+	.write_room = write_room,
+	.chars_in_buffer = chars_in_buffer,
+	.flush_buffer = flush_buffer,
+	.ioctl = ioctl,
+	.compat_ioctl = slgt_compat_ioctl,
+	.throttle = throttle,
+	.unthrottle = unthrottle,
+	.send_xchar = send_xchar,
+	.break_ctl = set_break,
+	.wait_until_sent = wait_until_sent,
+	.set_termios = set_termios,
+	.stop = tx_hold,
+	.start = tx_release,
+	.hangup = hangup,
+	.tiocmget = tiocmget,
+	.tiocmset = tiocmset,
+	.get_icount = get_icount,
+	.proc_show = synclink_gt_proc_show,
+};
+
+static void slgt_cleanup(void)
+{
+	struct slgt_info *info;
+	struct slgt_info *tmp;
+
+	if (serial_driver) {
+		for (info=slgt_device_list ; info != NULL ; info=info->next_device)
+			tty_unregister_device(serial_driver, info->line);
+		tty_unregister_driver(serial_driver);
+		tty_driver_kref_put(serial_driver);
+	}
+
+	/* reset devices */
+	info = slgt_device_list;
+	while(info) {
+		reset_port(info);
+		info = info->next_device;
+	}
+
+	/* release devices */
+	info = slgt_device_list;
+	while(info) {
+#if SYNCLINK_GENERIC_HDLC
+		hdlcdev_exit(info);
+#endif
+		free_dma_bufs(info);
+		free_tmp_rbuf(info);
+		if (info->port_num == 0)
+			release_resources(info);
+		tmp = info;
+		info = info->next_device;
+		tty_port_destroy(&tmp->port);
+		kfree(tmp);
+	}
+
+	if (pci_registered)
+		pci_unregister_driver(&pci_driver);
+}
+
+/*
+ *  Driver initialization entry point.
+ */
+static int __init slgt_init(void)
+{
+	int rc;
+
+	serial_driver = tty_alloc_driver(MAX_DEVICES, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(serial_driver)) {
+		printk("%s can't allocate tty driver\n", driver_name);
+		return PTR_ERR(serial_driver);
+	}
+
+	/* Initialize the tty_driver structure */
+
+	serial_driver->driver_name = "synclink_gt";
+	serial_driver->name = tty_dev_prefix;
+	serial_driver->major = ttymajor;
+	serial_driver->minor_start = 64;
+	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	serial_driver->subtype = SERIAL_TYPE_NORMAL;
+	serial_driver->init_termios = tty_std_termios;
+	serial_driver->init_termios.c_cflag =
+		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	serial_driver->init_termios.c_ispeed = 9600;
+	serial_driver->init_termios.c_ospeed = 9600;
+	tty_set_operations(serial_driver, &ops);
+	if ((rc = tty_register_driver(serial_driver)) < 0) {
+		DBGERR(("%s can't register serial driver\n", driver_name));
+		tty_driver_kref_put(serial_driver);
+		serial_driver = NULL;
+		goto error;
+	}
+
+	slgt_device_count = 0;
+	if ((rc = pci_register_driver(&pci_driver)) < 0) {
+		printk("%s pci_register_driver error=%d\n", driver_name, rc);
+		goto error;
+	}
+	pci_registered = true;
+
+	return 0;
+
+error:
+	slgt_cleanup();
+	return rc;
+}
+
+static void __exit slgt_exit(void)
+{
+	slgt_cleanup();
+}
+
+module_init(slgt_init);
+module_exit(slgt_exit);
+
+/*
+ * register access routines
+ */
+
+static inline void __iomem *calc_regaddr(struct slgt_info *info,
+					 unsigned int addr)
+{
+	void __iomem *reg_addr = info->reg_addr + addr;
+
+	if (addr >= 0x80)
+		reg_addr += info->port_num * 32;
+	else if (addr >= 0x40)
+		reg_addr += info->port_num * 16;
+
+	return reg_addr;
+}
+
+static __u8 rd_reg8(struct slgt_info *info, unsigned int addr)
+{
+	return readb(calc_regaddr(info, addr));
+}
+
+static void wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value)
+{
+	writeb(value, calc_regaddr(info, addr));
+}
+
+static __u16 rd_reg16(struct slgt_info *info, unsigned int addr)
+{
+	return readw(calc_regaddr(info, addr));
+}
+
+static void wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value)
+{
+	writew(value, calc_regaddr(info, addr));
+}
+
+static __u32 rd_reg32(struct slgt_info *info, unsigned int addr)
+{
+	return readl(calc_regaddr(info, addr));
+}
+
+static void wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value)
+{
+	writel(value, calc_regaddr(info, addr));
+}
+
+static void rdma_reset(struct slgt_info *info)
+{
+	unsigned int i;
+
+	/* set reset bit */
+	wr_reg32(info, RDCSR, BIT1);
+
+	/* wait for enable bit cleared */
+	for(i=0 ; i < 1000 ; i++)
+		if (!(rd_reg32(info, RDCSR) & BIT0))
+			break;
+}
+
+static void tdma_reset(struct slgt_info *info)
+{
+	unsigned int i;
+
+	/* set reset bit */
+	wr_reg32(info, TDCSR, BIT1);
+
+	/* wait for enable bit cleared */
+	for(i=0 ; i < 1000 ; i++)
+		if (!(rd_reg32(info, TDCSR) & BIT0))
+			break;
+}
+
+/*
+ * enable internal loopback
+ * TxCLK and RxCLK are generated from BRG
+ * and TxD is looped back to RxD internally.
+ */
+static void enable_loopback(struct slgt_info *info)
+{
+	/* SCR (serial control) BIT2=loopback enable */
+	wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT2));
+
+	if (info->params.mode != MGSL_MODE_ASYNC) {
+		/* CCR (clock control)
+		 * 07..05  tx clock source (010 = BRG)
+		 * 04..02  rx clock source (010 = BRG)
+		 * 01      auxclk enable   (0 = disable)
+		 * 00      BRG enable      (1 = enable)
+		 *
+		 * 0100 1001
+		 */
+		wr_reg8(info, CCR, 0x49);
+
+		/* set speed if available, otherwise use default */
+		if (info->params.clock_speed)
+			set_rate(info, info->params.clock_speed);
+		else
+			set_rate(info, 3686400);
+	}
+}
+
+/*
+ *  set baud rate generator to specified rate
+ */
+static void set_rate(struct slgt_info *info, u32 rate)
+{
+	unsigned int div;
+	unsigned int osc = info->base_clock;
+
+	/* div = osc/rate - 1
+	 *
+	 * Round div up if osc/rate is not integer to
+	 * force to next slowest rate.
+	 */
+
+	if (rate) {
+		div = osc/rate;
+		if (!(osc % rate) && div)
+			div--;
+		wr_reg16(info, BDR, (unsigned short)div);
+	}
+}
+
+static void rx_stop(struct slgt_info *info)
+{
+	unsigned short val;
+
+	/* disable and reset receiver */
+	val = rd_reg16(info, RCR) & ~BIT1;          /* clear enable bit */
+	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
+	wr_reg16(info, RCR, val);                  /* clear reset bit */
+
+	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA + IRQ_RXIDLE);
+
+	/* clear pending rx interrupts */
+	wr_reg16(info, SSR, IRQ_RXIDLE + IRQ_RXOVER);
+
+	rdma_reset(info);
+
+	info->rx_enabled = false;
+	info->rx_restart = false;
+}
+
+static void rx_start(struct slgt_info *info)
+{
+	unsigned short val;
+
+	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA);
+
+	/* clear pending rx overrun IRQ */
+	wr_reg16(info, SSR, IRQ_RXOVER);
+
+	/* reset and disable receiver */
+	val = rd_reg16(info, RCR) & ~BIT1; /* clear enable bit */
+	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
+	wr_reg16(info, RCR, val);                  /* clear reset bit */
+
+	rdma_reset(info);
+	reset_rbufs(info);
+
+	if (info->rx_pio) {
+		/* rx request when rx FIFO not empty */
+		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) & ~BIT14));
+		slgt_irq_on(info, IRQ_RXDATA);
+		if (info->params.mode == MGSL_MODE_ASYNC) {
+			/* enable saving of rx status */
+			wr_reg32(info, RDCSR, BIT6);
+		}
+	} else {
+		/* rx request when rx FIFO half full */
+		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT14));
+		/* set 1st descriptor address */
+		wr_reg32(info, RDDAR, info->rbufs[0].pdesc);
+
+		if (info->params.mode != MGSL_MODE_ASYNC) {
+			/* enable rx DMA and DMA interrupt */
+			wr_reg32(info, RDCSR, (BIT2 + BIT0));
+		} else {
+			/* enable saving of rx status, rx DMA and DMA interrupt */
+			wr_reg32(info, RDCSR, (BIT6 + BIT2 + BIT0));
+		}
+	}
+
+	slgt_irq_on(info, IRQ_RXOVER);
+
+	/* enable receiver */
+	wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | BIT1));
+
+	info->rx_restart = false;
+	info->rx_enabled = true;
+}
+
+static void tx_start(struct slgt_info *info)
+{
+	if (!info->tx_enabled) {
+		wr_reg16(info, TCR,
+			 (unsigned short)((rd_reg16(info, TCR) | BIT1) & ~BIT2));
+		info->tx_enabled = true;
+	}
+
+	if (desc_count(info->tbufs[info->tbuf_start])) {
+		info->drop_rts_on_tx_done = false;
+
+		if (info->params.mode != MGSL_MODE_ASYNC) {
+			if (info->params.flags & HDLC_FLAG_AUTO_RTS) {
+				get_gtsignals(info);
+				if (!(info->signals & SerialSignal_RTS)) {
+					info->signals |= SerialSignal_RTS;
+					set_gtsignals(info);
+					info->drop_rts_on_tx_done = true;
+				}
+			}
+
+			slgt_irq_off(info, IRQ_TXDATA);
+			slgt_irq_on(info, IRQ_TXUNDER + IRQ_TXIDLE);
+			/* clear tx idle and underrun status bits */
+			wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
+		} else {
+			slgt_irq_off(info, IRQ_TXDATA);
+			slgt_irq_on(info, IRQ_TXIDLE);
+			/* clear tx idle status bit */
+			wr_reg16(info, SSR, IRQ_TXIDLE);
+		}
+		/* set 1st descriptor address and start DMA */
+		wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
+		wr_reg32(info, TDCSR, BIT2 + BIT0);
+		info->tx_active = true;
+	}
+}
+
+static void tx_stop(struct slgt_info *info)
+{
+	unsigned short val;
+
+	del_timer(&info->tx_timer);
+
+	tdma_reset(info);
+
+	/* reset and disable transmitter */
+	val = rd_reg16(info, TCR) & ~BIT1;          /* clear enable bit */
+	wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
+
+	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
+
+	/* clear tx idle and underrun status bit */
+	wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
+
+	reset_tbufs(info);
+
+	info->tx_enabled = false;
+	info->tx_active = false;
+}
+
+static void reset_port(struct slgt_info *info)
+{
+	if (!info->reg_addr)
+		return;
+
+	tx_stop(info);
+	rx_stop(info);
+
+	info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
+	set_gtsignals(info);
+
+	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
+}
+
+static void reset_adapter(struct slgt_info *info)
+{
+	int i;
+	for (i=0; i < info->port_count; ++i) {
+		if (info->port_array[i])
+			reset_port(info->port_array[i]);
+	}
+}
+
+static void async_mode(struct slgt_info *info)
+{
+  	unsigned short val;
+
+	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
+	tx_stop(info);
+	rx_stop(info);
+
+	/* TCR (tx control)
+	 *
+	 * 15..13  mode, 010=async
+	 * 12..10  encoding, 000=NRZ
+	 * 09      parity enable
+	 * 08      1=odd parity, 0=even parity
+	 * 07      1=RTS driver control
+	 * 06      1=break enable
+	 * 05..04  character length
+	 *         00=5 bits
+	 *         01=6 bits
+	 *         10=7 bits
+	 *         11=8 bits
+	 * 03      0=1 stop bit, 1=2 stop bits
+	 * 02      reset
+	 * 01      enable
+	 * 00      auto-CTS enable
+	 */
+	val = 0x4000;
+
+	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
+		val |= BIT7;
+
+	if (info->params.parity != ASYNC_PARITY_NONE) {
+		val |= BIT9;
+		if (info->params.parity == ASYNC_PARITY_ODD)
+			val |= BIT8;
+	}
+
+	switch (info->params.data_bits)
+	{
+	case 6: val |= BIT4; break;
+	case 7: val |= BIT5; break;
+	case 8: val |= BIT5 + BIT4; break;
+	}
+
+	if (info->params.stop_bits != 1)
+		val |= BIT3;
+
+	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
+		val |= BIT0;
+
+	wr_reg16(info, TCR, val);
+
+	/* RCR (rx control)
+	 *
+	 * 15..13  mode, 010=async
+	 * 12..10  encoding, 000=NRZ
+	 * 09      parity enable
+	 * 08      1=odd parity, 0=even parity
+	 * 07..06  reserved, must be 0
+	 * 05..04  character length
+	 *         00=5 bits
+	 *         01=6 bits
+	 *         10=7 bits
+	 *         11=8 bits
+	 * 03      reserved, must be zero
+	 * 02      reset
+	 * 01      enable
+	 * 00      auto-DCD enable
+	 */
+	val = 0x4000;
+
+	if (info->params.parity != ASYNC_PARITY_NONE) {
+		val |= BIT9;
+		if (info->params.parity == ASYNC_PARITY_ODD)
+			val |= BIT8;
+	}
+
+	switch (info->params.data_bits)
+	{
+	case 6: val |= BIT4; break;
+	case 7: val |= BIT5; break;
+	case 8: val |= BIT5 + BIT4; break;
+	}
+
+	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
+		val |= BIT0;
+
+	wr_reg16(info, RCR, val);
+
+	/* CCR (clock control)
+	 *
+	 * 07..05  011 = tx clock source is BRG/16
+	 * 04..02  010 = rx clock source is BRG
+	 * 01      0 = auxclk disabled
+	 * 00      1 = BRG enabled
+	 *
+	 * 0110 1001
+	 */
+	wr_reg8(info, CCR, 0x69);
+
+	msc_set_vcr(info);
+
+	/* SCR (serial control)
+	 *
+	 * 15  1=tx req on FIFO half empty
+	 * 14  1=rx req on FIFO half full
+	 * 13  tx data  IRQ enable
+	 * 12  tx idle  IRQ enable
+	 * 11  rx break on IRQ enable
+	 * 10  rx data  IRQ enable
+	 * 09  rx break off IRQ enable
+	 * 08  overrun  IRQ enable
+	 * 07  DSR      IRQ enable
+	 * 06  CTS      IRQ enable
+	 * 05  DCD      IRQ enable
+	 * 04  RI       IRQ enable
+	 * 03  0=16x sampling, 1=8x sampling
+	 * 02  1=txd->rxd internal loopback enable
+	 * 01  reserved, must be zero
+	 * 00  1=master IRQ enable
+	 */
+	val = BIT15 + BIT14 + BIT0;
+	/* JCR[8] : 1 = x8 async mode feature available */
+	if ((rd_reg32(info, JCR) & BIT8) && info->params.data_rate &&
+	    ((info->base_clock < (info->params.data_rate * 16)) ||
+	     (info->base_clock % (info->params.data_rate * 16)))) {
+		/* use 8x sampling */
+		val |= BIT3;
+		set_rate(info, info->params.data_rate * 8);
+	} else {
+		/* use 16x sampling */
+		set_rate(info, info->params.data_rate * 16);
+	}
+	wr_reg16(info, SCR, val);
+
+	slgt_irq_on(info, IRQ_RXBREAK | IRQ_RXOVER);
+
+	if (info->params.loopback)
+		enable_loopback(info);
+}
+
+static void sync_mode(struct slgt_info *info)
+{
+	unsigned short val;
+
+	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
+	tx_stop(info);
+	rx_stop(info);
+
+	/* TCR (tx control)
+	 *
+	 * 15..13  mode
+	 *         000=HDLC/SDLC
+	 *         001=raw bit synchronous
+	 *         010=asynchronous/isochronous
+	 *         011=monosync byte synchronous
+	 *         100=bisync byte synchronous
+	 *         101=xsync byte synchronous
+	 * 12..10  encoding
+	 * 09      CRC enable
+	 * 08      CRC32
+	 * 07      1=RTS driver control
+	 * 06      preamble enable
+	 * 05..04  preamble length
+	 * 03      share open/close flag
+	 * 02      reset
+	 * 01      enable
+	 * 00      auto-CTS enable
+	 */
+	val = BIT2;
+
+	switch(info->params.mode) {
+	case MGSL_MODE_XSYNC:
+		val |= BIT15 + BIT13;
+		break;
+	case MGSL_MODE_MONOSYNC: val |= BIT14 + BIT13; break;
+	case MGSL_MODE_BISYNC:   val |= BIT15; break;
+	case MGSL_MODE_RAW:      val |= BIT13; break;
+	}
+	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
+		val |= BIT7;
+
+	switch(info->params.encoding)
+	{
+	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
+	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
+	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
+	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
+	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
+	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
+	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
+	}
+
+	switch (info->params.crc_type & HDLC_CRC_MASK)
+	{
+	case HDLC_CRC_16_CCITT: val |= BIT9; break;
+	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
+	}
+
+	if (info->params.preamble != HDLC_PREAMBLE_PATTERN_NONE)
+		val |= BIT6;
+
+	switch (info->params.preamble_length)
+	{
+	case HDLC_PREAMBLE_LENGTH_16BITS: val |= BIT5; break;
+	case HDLC_PREAMBLE_LENGTH_32BITS: val |= BIT4; break;
+	case HDLC_PREAMBLE_LENGTH_64BITS: val |= BIT5 + BIT4; break;
+	}
+
+	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
+		val |= BIT0;
+
+	wr_reg16(info, TCR, val);
+
+	/* TPR (transmit preamble) */
+
+	switch (info->params.preamble)
+	{
+	case HDLC_PREAMBLE_PATTERN_FLAGS: val = 0x7e; break;
+	case HDLC_PREAMBLE_PATTERN_ONES:  val = 0xff; break;
+	case HDLC_PREAMBLE_PATTERN_ZEROS: val = 0x00; break;
+	case HDLC_PREAMBLE_PATTERN_10:    val = 0x55; break;
+	case HDLC_PREAMBLE_PATTERN_01:    val = 0xaa; break;
+	default:                          val = 0x7e; break;
+	}
+	wr_reg8(info, TPR, (unsigned char)val);
+
+	/* RCR (rx control)
+	 *
+	 * 15..13  mode
+	 *         000=HDLC/SDLC
+	 *         001=raw bit synchronous
+	 *         010=asynchronous/isochronous
+	 *         011=monosync byte synchronous
+	 *         100=bisync byte synchronous
+	 *         101=xsync byte synchronous
+	 * 12..10  encoding
+	 * 09      CRC enable
+	 * 08      CRC32
+	 * 07..03  reserved, must be 0
+	 * 02      reset
+	 * 01      enable
+	 * 00      auto-DCD enable
+	 */
+	val = 0;
+
+	switch(info->params.mode) {
+	case MGSL_MODE_XSYNC:
+		val |= BIT15 + BIT13;
+		break;
+	case MGSL_MODE_MONOSYNC: val |= BIT14 + BIT13; break;
+	case MGSL_MODE_BISYNC:   val |= BIT15; break;
+	case MGSL_MODE_RAW:      val |= BIT13; break;
+	}
+
+	switch(info->params.encoding)
+	{
+	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
+	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
+	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
+	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
+	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
+	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
+	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
+	}
+
+	switch (info->params.crc_type & HDLC_CRC_MASK)
+	{
+	case HDLC_CRC_16_CCITT: val |= BIT9; break;
+	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
+	}
+
+	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
+		val |= BIT0;
+
+	wr_reg16(info, RCR, val);
+
+	/* CCR (clock control)
+	 *
+	 * 07..05  tx clock source
+	 * 04..02  rx clock source
+	 * 01      auxclk enable
+	 * 00      BRG enable
+	 */
+	val = 0;
+
+	if (info->params.flags & HDLC_FLAG_TXC_BRG)
+	{
+		// when RxC source is DPLL, BRG generates 16X DPLL
+		// reference clock, so take TxC from BRG/16 to get
+		// transmit clock at actual data rate
+		if (info->params.flags & HDLC_FLAG_RXC_DPLL)
+			val |= BIT6 + BIT5;	/* 011, txclk = BRG/16 */
+		else
+			val |= BIT6;	/* 010, txclk = BRG */
+	}
+	else if (info->params.flags & HDLC_FLAG_TXC_DPLL)
+		val |= BIT7;	/* 100, txclk = DPLL Input */
+	else if (info->params.flags & HDLC_FLAG_TXC_RXCPIN)
+		val |= BIT5;	/* 001, txclk = RXC Input */
+
+	if (info->params.flags & HDLC_FLAG_RXC_BRG)
+		val |= BIT3;	/* 010, rxclk = BRG */
+	else if (info->params.flags & HDLC_FLAG_RXC_DPLL)
+		val |= BIT4;	/* 100, rxclk = DPLL */
+	else if (info->params.flags & HDLC_FLAG_RXC_TXCPIN)
+		val |= BIT2;	/* 001, rxclk = TXC Input */
+
+	if (info->params.clock_speed)
+		val |= BIT1 + BIT0;
+
+	wr_reg8(info, CCR, (unsigned char)val);
+
+	if (info->params.flags & (HDLC_FLAG_TXC_DPLL + HDLC_FLAG_RXC_DPLL))
+	{
+		// program DPLL mode
+		switch(info->params.encoding)
+		{
+		case HDLC_ENCODING_BIPHASE_MARK:
+		case HDLC_ENCODING_BIPHASE_SPACE:
+			val = BIT7; break;
+		case HDLC_ENCODING_BIPHASE_LEVEL:
+		case HDLC_ENCODING_DIFF_BIPHASE_LEVEL:
+			val = BIT7 + BIT6; break;
+		default: val = BIT6;	// NRZ encodings
+		}
+		wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | val));
+
+		// DPLL requires a 16X reference clock from BRG
+		set_rate(info, info->params.clock_speed * 16);
+	}
+	else
+		set_rate(info, info->params.clock_speed);
+
+	tx_set_idle(info);
+
+	msc_set_vcr(info);
+
+	/* SCR (serial control)
+	 *
+	 * 15  1=tx req on FIFO half empty
+	 * 14  1=rx req on FIFO half full
+	 * 13  tx data  IRQ enable
+	 * 12  tx idle  IRQ enable
+	 * 11  underrun IRQ enable
+	 * 10  rx data  IRQ enable
+	 * 09  rx idle  IRQ enable
+	 * 08  overrun  IRQ enable
+	 * 07  DSR      IRQ enable
+	 * 06  CTS      IRQ enable
+	 * 05  DCD      IRQ enable
+	 * 04  RI       IRQ enable
+	 * 03  reserved, must be zero
+	 * 02  1=txd->rxd internal loopback enable
+	 * 01  reserved, must be zero
+	 * 00  1=master IRQ enable
+	 */
+	wr_reg16(info, SCR, BIT15 + BIT14 + BIT0);
+
+	if (info->params.loopback)
+		enable_loopback(info);
+}
+
+/*
+ *  set transmit idle mode
+ */
+static void tx_set_idle(struct slgt_info *info)
+{
+	unsigned char val;
+	unsigned short tcr;
+
+	/* if preamble enabled (tcr[6] == 1) then tx idle size = 8 bits
+	 * else tcr[5:4] = tx idle size: 00 = 8 bits, 01 = 16 bits
+	 */
+	tcr = rd_reg16(info, TCR);
+	if (info->idle_mode & HDLC_TXIDLE_CUSTOM_16) {
+		/* disable preamble, set idle size to 16 bits */
+		tcr = (tcr & ~(BIT6 + BIT5)) | BIT4;
+		/* MSB of 16 bit idle specified in tx preamble register (TPR) */
+		wr_reg8(info, TPR, (unsigned char)((info->idle_mode >> 8) & 0xff));
+	} else if (!(tcr & BIT6)) {
+		/* preamble is disabled, set idle size to 8 bits */
+		tcr &= ~(BIT5 + BIT4);
+	}
+	wr_reg16(info, TCR, tcr);
+
+	if (info->idle_mode & (HDLC_TXIDLE_CUSTOM_8 | HDLC_TXIDLE_CUSTOM_16)) {
+		/* LSB of custom tx idle specified in tx idle register */
+		val = (unsigned char)(info->idle_mode & 0xff);
+	} else {
+		/* standard 8 bit idle patterns */
+		switch(info->idle_mode)
+		{
+		case HDLC_TXIDLE_FLAGS:          val = 0x7e; break;
+		case HDLC_TXIDLE_ALT_ZEROS_ONES:
+		case HDLC_TXIDLE_ALT_MARK_SPACE: val = 0xaa; break;
+		case HDLC_TXIDLE_ZEROS:
+		case HDLC_TXIDLE_SPACE:          val = 0x00; break;
+		default:                         val = 0xff;
+		}
+	}
+
+	wr_reg8(info, TIR, val);
+}
+
+/*
+ * get state of V24 status (input) signals
+ */
+static void get_gtsignals(struct slgt_info *info)
+{
+	unsigned short status = rd_reg16(info, SSR);
+
+	/* clear all serial signals except RTS and DTR */
+	info->signals &= SerialSignal_RTS | SerialSignal_DTR;
+
+	if (status & BIT3)
+		info->signals |= SerialSignal_DSR;
+	if (status & BIT2)
+		info->signals |= SerialSignal_CTS;
+	if (status & BIT1)
+		info->signals |= SerialSignal_DCD;
+	if (status & BIT0)
+		info->signals |= SerialSignal_RI;
+}
+
+/*
+ * set V.24 Control Register based on current configuration
+ */
+static void msc_set_vcr(struct slgt_info *info)
+{
+	unsigned char val = 0;
+
+	/* VCR (V.24 control)
+	 *
+	 * 07..04  serial IF select
+	 * 03      DTR
+	 * 02      RTS
+	 * 01      LL
+	 * 00      RL
+	 */
+
+	switch(info->if_mode & MGSL_INTERFACE_MASK)
+	{
+	case MGSL_INTERFACE_RS232:
+		val |= BIT5; /* 0010 */
+		break;
+	case MGSL_INTERFACE_V35:
+		val |= BIT7 + BIT6 + BIT5; /* 1110 */
+		break;
+	case MGSL_INTERFACE_RS422:
+		val |= BIT6; /* 0100 */
+		break;
+	}
+
+	if (info->if_mode & MGSL_INTERFACE_MSB_FIRST)
+		val |= BIT4;
+	if (info->signals & SerialSignal_DTR)
+		val |= BIT3;
+	if (info->signals & SerialSignal_RTS)
+		val |= BIT2;
+	if (info->if_mode & MGSL_INTERFACE_LL)
+		val |= BIT1;
+	if (info->if_mode & MGSL_INTERFACE_RL)
+		val |= BIT0;
+	wr_reg8(info, VCR, val);
+}
+
+/*
+ * set state of V24 control (output) signals
+ */
+static void set_gtsignals(struct slgt_info *info)
+{
+	unsigned char val = rd_reg8(info, VCR);
+	if (info->signals & SerialSignal_DTR)
+		val |= BIT3;
+	else
+		val &= ~BIT3;
+	if (info->signals & SerialSignal_RTS)
+		val |= BIT2;
+	else
+		val &= ~BIT2;
+	wr_reg8(info, VCR, val);
+}
+
+/*
+ * free range of receive DMA buffers (i to last)
+ */
+static void free_rbufs(struct slgt_info *info, unsigned int i, unsigned int last)
+{
+	int done = 0;
+
+	while(!done) {
+		/* reset current buffer for reuse */
+		info->rbufs[i].status = 0;
+		set_desc_count(info->rbufs[i], info->rbuf_fill_level);
+		if (i == last)
+			done = 1;
+		if (++i == info->rbuf_count)
+			i = 0;
+	}
+	info->rbuf_current = i;
+}
+
+/*
+ * mark all receive DMA buffers as free
+ */
+static void reset_rbufs(struct slgt_info *info)
+{
+	free_rbufs(info, 0, info->rbuf_count - 1);
+	info->rbuf_fill_index = 0;
+	info->rbuf_fill_count = 0;
+}
+
+/*
+ * pass receive HDLC frame to upper layer
+ *
+ * return true if frame available, otherwise false
+ */
+static bool rx_get_frame(struct slgt_info *info)
+{
+	unsigned int start, end;
+	unsigned short status;
+	unsigned int framesize = 0;
+	unsigned long flags;
+	struct tty_struct *tty = info->port.tty;
+	unsigned char addr_field = 0xff;
+	unsigned int crc_size = 0;
+
+	switch (info->params.crc_type & HDLC_CRC_MASK) {
+	case HDLC_CRC_16_CCITT: crc_size = 2; break;
+	case HDLC_CRC_32_CCITT: crc_size = 4; break;
+	}
+
+check_again:
+
+	framesize = 0;
+	addr_field = 0xff;
+	start = end = info->rbuf_current;
+
+	for (;;) {
+		if (!desc_complete(info->rbufs[end]))
+			goto cleanup;
+
+		if (framesize == 0 && info->params.addr_filter != 0xff)
+			addr_field = info->rbufs[end].buf[0];
+
+		framesize += desc_count(info->rbufs[end]);
+
+		if (desc_eof(info->rbufs[end]))
+			break;
+
+		if (++end == info->rbuf_count)
+			end = 0;
+
+		if (end == info->rbuf_current) {
+			if (info->rx_enabled){
+				spin_lock_irqsave(&info->lock,flags);
+				rx_start(info);
+				spin_unlock_irqrestore(&info->lock,flags);
+			}
+			goto cleanup;
+		}
+	}
+
+	/* status
+	 *
+	 * 15      buffer complete
+	 * 14..06  reserved
+	 * 05..04  residue
+	 * 02      eof (end of frame)
+	 * 01      CRC error
+	 * 00      abort
+	 */
+	status = desc_status(info->rbufs[end]);
+
+	/* ignore CRC bit if not using CRC (bit is undefined) */
+	if ((info->params.crc_type & HDLC_CRC_MASK) == HDLC_CRC_NONE)
+		status &= ~BIT1;
+
+	if (framesize == 0 ||
+		 (addr_field != 0xff && addr_field != info->params.addr_filter)) {
+		free_rbufs(info, start, end);
+		goto check_again;
+	}
+
+	if (framesize < (2 + crc_size) || status & BIT0) {
+		info->icount.rxshort++;
+		framesize = 0;
+	} else if (status & BIT1) {
+		info->icount.rxcrc++;
+		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX))
+			framesize = 0;
+	}
+
+#if SYNCLINK_GENERIC_HDLC
+	if (framesize == 0) {
+		info->netdev->stats.rx_errors++;
+		info->netdev->stats.rx_frame_errors++;
+	}
+#endif
+
+	DBGBH(("%s rx frame status=%04X size=%d\n",
+		info->device_name, status, framesize));
+	DBGDATA(info, info->rbufs[start].buf, min_t(int, framesize, info->rbuf_fill_level), "rx");
+
+	if (framesize) {
+		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX)) {
+			framesize -= crc_size;
+			crc_size = 0;
+		}
+
+		if (framesize > info->max_frame_size + crc_size)
+			info->icount.rxlong++;
+		else {
+			/* copy dma buffer(s) to contiguous temp buffer */
+			int copy_count = framesize;
+			int i = start;
+			unsigned char *p = info->tmp_rbuf;
+			info->tmp_rbuf_count = framesize;
+
+			info->icount.rxok++;
+
+			while(copy_count) {
+				int partial_count = min_t(int, copy_count, info->rbuf_fill_level);
+				memcpy(p, info->rbufs[i].buf, partial_count);
+				p += partial_count;
+				copy_count -= partial_count;
+				if (++i == info->rbuf_count)
+					i = 0;
+			}
+
+			if (info->params.crc_type & HDLC_CRC_RETURN_EX) {
+				*p = (status & BIT1) ? RX_CRC_ERROR : RX_OK;
+				framesize++;
+			}
+
+#if SYNCLINK_GENERIC_HDLC
+			if (info->netcount)
+				hdlcdev_rx(info,info->tmp_rbuf, framesize);
+			else
+#endif
+				ldisc_receive_buf(tty, info->tmp_rbuf, NULL,
+						  framesize);
+		}
+	}
+	free_rbufs(info, start, end);
+	return true;
+
+cleanup:
+	return false;
+}
+
+/*
+ * pass receive buffer (RAW synchronous mode) to tty layer
+ * return true if buffer available, otherwise false
+ */
+static bool rx_get_buf(struct slgt_info *info)
+{
+	unsigned int i = info->rbuf_current;
+	unsigned int count;
+
+	if (!desc_complete(info->rbufs[i]))
+		return false;
+	count = desc_count(info->rbufs[i]);
+	switch(info->params.mode) {
+	case MGSL_MODE_MONOSYNC:
+	case MGSL_MODE_BISYNC:
+	case MGSL_MODE_XSYNC:
+		/* ignore residue in byte synchronous modes */
+		if (desc_residue(info->rbufs[i]))
+			count--;
+		break;
+	}
+	DBGDATA(info, info->rbufs[i].buf, count, "rx");
+	DBGINFO(("rx_get_buf size=%d\n", count));
+	if (count)
+		ldisc_receive_buf(info->port.tty, info->rbufs[i].buf, NULL,
+				  count);
+	free_rbufs(info, i, i);
+	return true;
+}
+
+static void reset_tbufs(struct slgt_info *info)
+{
+	unsigned int i;
+	info->tbuf_current = 0;
+	for (i=0 ; i < info->tbuf_count ; i++) {
+		info->tbufs[i].status = 0;
+		info->tbufs[i].count  = 0;
+	}
+}
+
+/*
+ * return number of free transmit DMA buffers
+ */
+static unsigned int free_tbuf_count(struct slgt_info *info)
+{
+	unsigned int count = 0;
+	unsigned int i = info->tbuf_current;
+
+	do
+	{
+		if (desc_count(info->tbufs[i]))
+			break; /* buffer in use */
+		++count;
+		if (++i == info->tbuf_count)
+			i=0;
+	} while (i != info->tbuf_current);
+
+	/* if tx DMA active, last zero count buffer is in use */
+	if (count && (rd_reg32(info, TDCSR) & BIT0))
+		--count;
+
+	return count;
+}
+
+/*
+ * return number of bytes in unsent transmit DMA buffers
+ * and the serial controller tx FIFO
+ */
+static unsigned int tbuf_bytes(struct slgt_info *info)
+{
+	unsigned int total_count = 0;
+	unsigned int i = info->tbuf_current;
+	unsigned int reg_value;
+	unsigned int count;
+	unsigned int active_buf_count = 0;
+
+	/*
+	 * Add descriptor counts for all tx DMA buffers.
+	 * If count is zero (cleared by DMA controller after read),
+	 * the buffer is complete or is actively being read from.
+	 *
+	 * Record buf_count of last buffer with zero count starting
+	 * from current ring position. buf_count is mirror
+	 * copy of count and is not cleared by serial controller.
+	 * If DMA controller is active, that buffer is actively
+	 * being read so add to total.
+	 */
+	do {
+		count = desc_count(info->tbufs[i]);
+		if (count)
+			total_count += count;
+		else if (!total_count)
+			active_buf_count = info->tbufs[i].buf_count;
+		if (++i == info->tbuf_count)
+			i = 0;
+	} while (i != info->tbuf_current);
+
+	/* read tx DMA status register */
+	reg_value = rd_reg32(info, TDCSR);
+
+	/* if tx DMA active, last zero count buffer is in use */
+	if (reg_value & BIT0)
+		total_count += active_buf_count;
+
+	/* add tx FIFO count = reg_value[15..8] */
+	total_count += (reg_value >> 8) & 0xff;
+
+	/* if transmitter active add one byte for shift register */
+	if (info->tx_active)
+		total_count++;
+
+	return total_count;
+}
+
+/*
+ * load data into transmit DMA buffer ring and start transmitter if needed
+ * return true if data accepted, otherwise false (buffers full)
+ */
+static bool tx_load(struct slgt_info *info, const u8 *buf, unsigned int size)
+{
+	unsigned short count;
+	unsigned int i;
+	struct slgt_desc *d;
+
+	/* check required buffer space */
+	if (DIV_ROUND_UP(size, DMABUFSIZE) > free_tbuf_count(info))
+		return false;
+
+	DBGDATA(info, buf, size, "tx");
+
+	/*
+	 * copy data to one or more DMA buffers in circular ring
+	 * tbuf_start   = first buffer for this data
+	 * tbuf_current = next free buffer
+	 *
+	 * Copy all data before making data visible to DMA controller by
+	 * setting descriptor count of the first buffer.
+	 * This prevents an active DMA controller from reading the first DMA
+	 * buffers of a frame and stopping before the final buffers are filled.
+	 */
+
+	info->tbuf_start = i = info->tbuf_current;
+
+	while (size) {
+		d = &info->tbufs[i];
+
+		count = (unsigned short)((size > DMABUFSIZE) ? DMABUFSIZE : size);
+		memcpy(d->buf, buf, count);
+
+		size -= count;
+		buf  += count;
+
+		/*
+		 * set EOF bit for last buffer of HDLC frame or
+		 * for every buffer in raw mode
+		 */
+		if ((!size && info->params.mode == MGSL_MODE_HDLC) ||
+		    info->params.mode == MGSL_MODE_RAW)
+			set_desc_eof(*d, 1);
+		else
+			set_desc_eof(*d, 0);
+
+		/* set descriptor count for all but first buffer */
+		if (i != info->tbuf_start)
+			set_desc_count(*d, count);
+		d->buf_count = count;
+
+		if (++i == info->tbuf_count)
+			i = 0;
+	}
+
+	info->tbuf_current = i;
+
+	/* set first buffer count to make new data visible to DMA controller */
+	d = &info->tbufs[info->tbuf_start];
+	set_desc_count(*d, d->buf_count);
+
+	/* start transmitter if needed and update transmit timeout */
+	if (!info->tx_active)
+		tx_start(info);
+	update_tx_timer(info);
+
+	return true;
+}
+
+static int register_test(struct slgt_info *info)
+{
+	static unsigned short patterns[] =
+		{0x0000, 0xffff, 0xaaaa, 0x5555, 0x6969, 0x9696};
+	static unsigned int count = ARRAY_SIZE(patterns);
+	unsigned int i;
+	int rc = 0;
+
+	for (i=0 ; i < count ; i++) {
+		wr_reg16(info, TIR, patterns[i]);
+		wr_reg16(info, BDR, patterns[(i+1)%count]);
+		if ((rd_reg16(info, TIR) != patterns[i]) ||
+		    (rd_reg16(info, BDR) != patterns[(i+1)%count])) {
+			rc = -ENODEV;
+			break;
+		}
+	}
+	info->gpio_present = (rd_reg32(info, JCR) & BIT5) ? 1 : 0;
+	info->init_error = rc ? 0 : DiagStatus_AddressFailure;
+	return rc;
+}
+
+static int irq_test(struct slgt_info *info)
+{
+	unsigned long timeout;
+	unsigned long flags;
+	struct tty_struct *oldtty = info->port.tty;
+	u32 speed = info->params.data_rate;
+
+	info->params.data_rate = 921600;
+	info->port.tty = NULL;
+
+	spin_lock_irqsave(&info->lock, flags);
+	async_mode(info);
+	slgt_irq_on(info, IRQ_TXIDLE);
+
+	/* enable transmitter */
+	wr_reg16(info, TCR,
+		(unsigned short)(rd_reg16(info, TCR) | BIT1));
+
+	/* write one byte and wait for tx idle */
+	wr_reg16(info, TDR, 0);
+
+	/* assume failure */
+	info->init_error = DiagStatus_IrqFailure;
+	info->irq_occurred = false;
+
+	spin_unlock_irqrestore(&info->lock, flags);
+
+	timeout=100;
+	while(timeout-- && !info->irq_occurred)
+		msleep_interruptible(10);
+
+	spin_lock_irqsave(&info->lock,flags);
+	reset_port(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	info->params.data_rate = speed;
+	info->port.tty = oldtty;
+
+	info->init_error = info->irq_occurred ? 0 : DiagStatus_IrqFailure;
+	return info->irq_occurred ? 0 : -ENODEV;
+}
+
+static int loopback_test_rx(struct slgt_info *info)
+{
+	unsigned char *src, *dest;
+	int count;
+
+	if (desc_complete(info->rbufs[0])) {
+		count = desc_count(info->rbufs[0]);
+		src   = info->rbufs[0].buf;
+		dest  = info->tmp_rbuf;
+
+		for( ; count ; count-=2, src+=2) {
+			/* src=data byte (src+1)=status byte */
+			if (!(*(src+1) & (BIT9 + BIT8))) {
+				*dest = *src;
+				dest++;
+				info->tmp_rbuf_count++;
+			}
+		}
+		DBGDATA(info, info->tmp_rbuf, info->tmp_rbuf_count, "rx");
+		return 1;
+	}
+	return 0;
+}
+
+static int loopback_test(struct slgt_info *info)
+{
+#define TESTFRAMESIZE 20
+
+	unsigned long timeout;
+	u16 count;
+	unsigned char buf[TESTFRAMESIZE];
+	int rc = -ENODEV;
+	unsigned long flags;
+
+	struct tty_struct *oldtty = info->port.tty;
+	MGSL_PARAMS params;
+
+	memcpy(&params, &info->params, sizeof(params));
+
+	info->params.mode = MGSL_MODE_ASYNC;
+	info->params.data_rate = 921600;
+	info->params.loopback = 1;
+	info->port.tty = NULL;
+
+	/* build and send transmit frame */
+	for (count = 0; count < TESTFRAMESIZE; ++count)
+		buf[count] = (unsigned char)count;
+
+	info->tmp_rbuf_count = 0;
+	memset(info->tmp_rbuf, 0, TESTFRAMESIZE);
+
+	/* program hardware for HDLC and enabled receiver */
+	spin_lock_irqsave(&info->lock,flags);
+	async_mode(info);
+	rx_start(info);
+	tx_load(info, buf, count);
+	spin_unlock_irqrestore(&info->lock, flags);
+
+	/* wait for receive complete */
+	for (timeout = 100; timeout; --timeout) {
+		msleep_interruptible(10);
+		if (loopback_test_rx(info)) {
+			rc = 0;
+			break;
+		}
+	}
+
+	/* verify received frame length and contents */
+	if (!rc && (info->tmp_rbuf_count != count ||
+		  memcmp(buf, info->tmp_rbuf, count))) {
+		rc = -ENODEV;
+	}
+
+	spin_lock_irqsave(&info->lock,flags);
+	reset_adapter(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+	memcpy(&info->params, &params, sizeof(info->params));
+	info->port.tty = oldtty;
+
+	info->init_error = rc ? DiagStatus_DmaFailure : 0;
+	return rc;
+}
+
+static int adapter_test(struct slgt_info *info)
+{
+	DBGINFO(("testing %s\n", info->device_name));
+	if (register_test(info) < 0) {
+		printk("register test failure %s addr=%08X\n",
+			info->device_name, info->phys_reg_addr);
+	} else if (irq_test(info) < 0) {
+		printk("IRQ test failure %s IRQ=%d\n",
+			info->device_name, info->irq_level);
+	} else if (loopback_test(info) < 0) {
+		printk("loopback test failure %s\n", info->device_name);
+	}
+	return info->init_error;
+}
+
+/*
+ * transmit timeout handler
+ */
+static void tx_timeout(struct timer_list *t)
+{
+	struct slgt_info *info = from_timer(info, t, tx_timer);
+	unsigned long flags;
+
+	DBGINFO(("%s tx_timeout\n", info->device_name));
+	if(info->tx_active && info->params.mode == MGSL_MODE_HDLC) {
+		info->icount.txtimeout++;
+	}
+	spin_lock_irqsave(&info->lock,flags);
+	tx_stop(info);
+	spin_unlock_irqrestore(&info->lock,flags);
+
+#if SYNCLINK_GENERIC_HDLC
+	if (info->netcount)
+		hdlcdev_tx_done(info);
+	else
+#endif
+		bh_transmit(info);
+}
+
+/*
+ * receive buffer polling timer
+ */
+static void rx_timeout(struct timer_list *t)
+{
+	struct slgt_info *info = from_timer(info, t, rx_timer);
+	unsigned long flags;
+
+	DBGINFO(("%s rx_timeout\n", info->device_name));
+	spin_lock_irqsave(&info->lock, flags);
+	info->pending_bh |= BH_RECEIVE;
+	spin_unlock_irqrestore(&info->lock, flags);
+	bh_handler(&info->task);
+}
+
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
new file mode 100644
index 000000000..6b4a28bcf
--- /dev/null
+++ b/drivers/tty/sysrq.c
@@ -0,0 +1,1197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *	Linux Magic System Request Key Hacks
+ *
+ *	(c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *	based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
+ *
+ *	(c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
+ *	overhauled to use key registration
+ *	based upon discusions in irc://irc.openprojects.net/#kernelnewbies
+ *
+ *	Copyright (c) 2010 Dmitry Torokhov
+ *	Input handler conversion
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/sched/signal.h>
+#include <linux/sched/rt.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/ctype.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/kdev_t.h>
+#include <linux/major.h>
+#include <linux/reboot.h>
+#include <linux/sysrq.h>
+#include <linux/kbd_kern.h>
+#include <linux/proc_fs.h>
+#include <linux/nmi.h>
+#include <linux/quotaops.h>
+#include <linux/perf_event.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/suspend.h>
+#include <linux/writeback.h>
+#include <linux/swap.h>
+#include <linux/spinlock.h>
+#include <linux/vt_kern.h>
+#include <linux/workqueue.h>
+#include <linux/hrtimer.h>
+#include <linux/oom.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/uaccess.h>
+#include <linux/moduleparam.h>
+#include <linux/jiffies.h>
+#include <linux/syscalls.h>
+#include <linux/of.h>
+#include <linux/rcupdate.h>
+
+#include <asm/ptrace.h>
+#include <asm/irq_regs.h>
+
+/* Whether we react on sysrq keys or just ignore them */
+static int __read_mostly sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
+static bool __read_mostly sysrq_always_enabled;
+
+static bool sysrq_on(void)
+{
+	return sysrq_enabled || sysrq_always_enabled;
+}
+
+/**
+ * sysrq_mask - Getter for sysrq_enabled mask.
+ *
+ * Return: 1 if sysrq is always enabled, enabled sysrq_key_op mask otherwise.
+ */
+int sysrq_mask(void)
+{
+	if (sysrq_always_enabled)
+		return 1;
+	return sysrq_enabled;
+}
+EXPORT_SYMBOL_GPL(sysrq_mask);
+
+/*
+ * A value of 1 means 'all', other nonzero values are an op mask:
+ */
+static bool sysrq_on_mask(int mask)
+{
+	return sysrq_always_enabled ||
+	       sysrq_enabled == 1 ||
+	       (sysrq_enabled & mask);
+}
+
+static int __init sysrq_always_enabled_setup(char *str)
+{
+	sysrq_always_enabled = true;
+	pr_info("sysrq always enabled.\n");
+
+	return 1;
+}
+
+__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
+
+
+static void sysrq_handle_loglevel(u8 key)
+{
+	u8 loglevel = key - '0';
+
+	console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
+	pr_info("Loglevel set to %u\n", loglevel);
+	console_loglevel = loglevel;
+}
+static const struct sysrq_key_op sysrq_loglevel_op = {
+	.handler	= sysrq_handle_loglevel,
+	.help_msg	= "loglevel(0-9)",
+	.action_msg	= "Changing Loglevel",
+	.enable_mask	= SYSRQ_ENABLE_LOG,
+};
+
+#ifdef CONFIG_VT
+static void sysrq_handle_SAK(u8 key)
+{
+	struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+
+	schedule_work(SAK_work);
+}
+static const struct sysrq_key_op sysrq_SAK_op = {
+	.handler	= sysrq_handle_SAK,
+	.help_msg	= "sak(k)",
+	.action_msg	= "SAK",
+	.enable_mask	= SYSRQ_ENABLE_KEYBOARD,
+};
+#else
+#define sysrq_SAK_op (*(const struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_VT
+static void sysrq_handle_unraw(u8 key)
+{
+	vt_reset_unicode(fg_console);
+}
+
+static const struct sysrq_key_op sysrq_unraw_op = {
+	.handler	= sysrq_handle_unraw,
+	.help_msg	= "unraw(r)",
+	.action_msg	= "Keyboard mode set to system default",
+	.enable_mask	= SYSRQ_ENABLE_KEYBOARD,
+};
+#else
+#define sysrq_unraw_op (*(const struct sysrq_key_op *)NULL)
+#endif /* CONFIG_VT */
+
+static void sysrq_handle_crash(u8 key)
+{
+	/* release the RCU read lock before crashing */
+	rcu_read_unlock();
+
+	panic("sysrq triggered crash\n");
+}
+static const struct sysrq_key_op sysrq_crash_op = {
+	.handler	= sysrq_handle_crash,
+	.help_msg	= "crash(c)",
+	.action_msg	= "Trigger a crash",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_reboot(u8 key)
+{
+	lockdep_off();
+	local_irq_enable();
+	emergency_restart();
+}
+static const struct sysrq_key_op sysrq_reboot_op = {
+	.handler	= sysrq_handle_reboot,
+	.help_msg	= "reboot(b)",
+	.action_msg	= "Resetting",
+	.enable_mask	= SYSRQ_ENABLE_BOOT,
+};
+
+const struct sysrq_key_op *__sysrq_reboot_op = &sysrq_reboot_op;
+
+static void sysrq_handle_sync(u8 key)
+{
+	emergency_sync();
+}
+static const struct sysrq_key_op sysrq_sync_op = {
+	.handler	= sysrq_handle_sync,
+	.help_msg	= "sync(s)",
+	.action_msg	= "Emergency Sync",
+	.enable_mask	= SYSRQ_ENABLE_SYNC,
+};
+
+static void sysrq_handle_show_timers(u8 key)
+{
+	sysrq_timer_list_show();
+}
+
+static const struct sysrq_key_op sysrq_show_timers_op = {
+	.handler	= sysrq_handle_show_timers,
+	.help_msg	= "show-all-timers(q)",
+	.action_msg	= "Show clockevent devices & pending hrtimers (no others)",
+};
+
+static void sysrq_handle_mountro(u8 key)
+{
+	emergency_remount();
+}
+static const struct sysrq_key_op sysrq_mountro_op = {
+	.handler	= sysrq_handle_mountro,
+	.help_msg	= "unmount(u)",
+	.action_msg	= "Emergency Remount R/O",
+	.enable_mask	= SYSRQ_ENABLE_REMOUNT,
+};
+
+#ifdef CONFIG_LOCKDEP
+static void sysrq_handle_showlocks(u8 key)
+{
+	debug_show_all_locks();
+}
+
+static const struct sysrq_key_op sysrq_showlocks_op = {
+	.handler	= sysrq_handle_showlocks,
+	.help_msg	= "show-all-locks(d)",
+	.action_msg	= "Show Locks Held",
+};
+#else
+#define sysrq_showlocks_op (*(const struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_SMP
+static DEFINE_RAW_SPINLOCK(show_lock);
+
+static void showacpu(void *dummy)
+{
+	unsigned long flags;
+
+	/* Idle CPUs have no interesting backtrace. */
+	if (idle_cpu(smp_processor_id())) {
+		pr_info("CPU%d: backtrace skipped as idling\n", smp_processor_id());
+		return;
+	}
+
+	raw_spin_lock_irqsave(&show_lock, flags);
+	pr_info("CPU%d:\n", smp_processor_id());
+	show_stack(NULL, NULL, KERN_INFO);
+	raw_spin_unlock_irqrestore(&show_lock, flags);
+}
+
+static void sysrq_showregs_othercpus(struct work_struct *dummy)
+{
+	smp_call_function(showacpu, NULL, 0);
+}
+
+static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
+
+static void sysrq_handle_showallcpus(u8 key)
+{
+	/*
+	 * Fall back to the workqueue based printing if the
+	 * backtrace printing did not succeed or the
+	 * architecture has no support for it:
+	 */
+	if (!trigger_all_cpu_backtrace()) {
+		struct pt_regs *regs = NULL;
+
+		if (in_hardirq())
+			regs = get_irq_regs();
+
+		pr_info("CPU%d:\n", get_cpu());
+		if (regs)
+			show_regs(regs);
+		else
+			show_stack(NULL, NULL, KERN_INFO);
+
+		schedule_work(&sysrq_showallcpus);
+		put_cpu();
+	}
+}
+
+static const struct sysrq_key_op sysrq_showallcpus_op = {
+	.handler	= sysrq_handle_showallcpus,
+	.help_msg	= "show-backtrace-all-active-cpus(l)",
+	.action_msg	= "Show backtrace of all active CPUs",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+#else
+#define sysrq_showallcpus_op (*(const struct sysrq_key_op *)NULL)
+#endif
+
+static void sysrq_handle_showregs(u8 key)
+{
+	struct pt_regs *regs = NULL;
+
+	if (in_hardirq())
+		regs = get_irq_regs();
+	if (regs)
+		show_regs(regs);
+	perf_event_print_debug();
+}
+static const struct sysrq_key_op sysrq_showregs_op = {
+	.handler	= sysrq_handle_showregs,
+	.help_msg	= "show-registers(p)",
+	.action_msg	= "Show Regs",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_showstate(u8 key)
+{
+	show_state();
+	show_all_workqueues();
+}
+static const struct sysrq_key_op sysrq_showstate_op = {
+	.handler	= sysrq_handle_showstate,
+	.help_msg	= "show-task-states(t)",
+	.action_msg	= "Show State",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_showstate_blocked(u8 key)
+{
+	show_state_filter(TASK_UNINTERRUPTIBLE);
+}
+static const struct sysrq_key_op sysrq_showstate_blocked_op = {
+	.handler	= sysrq_handle_showstate_blocked,
+	.help_msg	= "show-blocked-tasks(w)",
+	.action_msg	= "Show Blocked State",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+#ifdef CONFIG_TRACING
+#include <linux/ftrace.h>
+
+static void sysrq_ftrace_dump(u8 key)
+{
+	ftrace_dump(DUMP_ALL);
+}
+static const struct sysrq_key_op sysrq_ftrace_dump_op = {
+	.handler	= sysrq_ftrace_dump,
+	.help_msg	= "dump-ftrace-buffer(z)",
+	.action_msg	= "Dump ftrace buffer",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+#else
+#define sysrq_ftrace_dump_op (*(const struct sysrq_key_op *)NULL)
+#endif
+
+static void sysrq_handle_showmem(u8 key)
+{
+	show_mem();
+}
+static const struct sysrq_key_op sysrq_showmem_op = {
+	.handler	= sysrq_handle_showmem,
+	.help_msg	= "show-memory-usage(m)",
+	.action_msg	= "Show Memory",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+/*
+ * Signal sysrq helper function.  Sends a signal to all user processes.
+ */
+static void send_sig_all(int sig)
+{
+	struct task_struct *p;
+
+	read_lock(&tasklist_lock);
+	for_each_process(p) {
+		if (p->flags & PF_KTHREAD)
+			continue;
+		if (is_global_init(p))
+			continue;
+
+		do_send_sig_info(sig, SEND_SIG_PRIV, p, PIDTYPE_MAX);
+	}
+	read_unlock(&tasklist_lock);
+}
+
+static void sysrq_handle_term(u8 key)
+{
+	send_sig_all(SIGTERM);
+	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
+}
+static const struct sysrq_key_op sysrq_term_op = {
+	.handler	= sysrq_handle_term,
+	.help_msg	= "terminate-all-tasks(e)",
+	.action_msg	= "Terminate All Tasks",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+
+static void moom_callback(struct work_struct *ignored)
+{
+	const gfp_t gfp_mask = GFP_KERNEL;
+	struct oom_control oc = {
+		.zonelist = node_zonelist(first_memory_node, gfp_mask),
+		.nodemask = NULL,
+		.memcg = NULL,
+		.gfp_mask = gfp_mask,
+		.order = -1,
+	};
+
+	mutex_lock(&oom_lock);
+	if (!out_of_memory(&oc))
+		pr_info("OOM request ignored. No task eligible\n");
+	mutex_unlock(&oom_lock);
+}
+
+static DECLARE_WORK(moom_work, moom_callback);
+
+static void sysrq_handle_moom(u8 key)
+{
+	schedule_work(&moom_work);
+}
+static const struct sysrq_key_op sysrq_moom_op = {
+	.handler	= sysrq_handle_moom,
+	.help_msg	= "memory-full-oom-kill(f)",
+	.action_msg	= "Manual OOM execution",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+
+#ifdef CONFIG_BLOCK
+static void sysrq_handle_thaw(u8 key)
+{
+	emergency_thaw_all();
+}
+static const struct sysrq_key_op sysrq_thaw_op = {
+	.handler	= sysrq_handle_thaw,
+	.help_msg	= "thaw-filesystems(j)",
+	.action_msg	= "Emergency Thaw of all frozen filesystems",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+#else
+#define sysrq_thaw_op (*(const struct sysrq_key_op *)NULL)
+#endif
+
+static void sysrq_handle_kill(u8 key)
+{
+	send_sig_all(SIGKILL);
+	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
+}
+static const struct sysrq_key_op sysrq_kill_op = {
+	.handler	= sysrq_handle_kill,
+	.help_msg	= "kill-all-tasks(i)",
+	.action_msg	= "Kill All Tasks",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+
+static void sysrq_handle_unrt(u8 key)
+{
+	normalize_rt_tasks();
+}
+static const struct sysrq_key_op sysrq_unrt_op = {
+	.handler	= sysrq_handle_unrt,
+	.help_msg	= "nice-all-RT-tasks(n)",
+	.action_msg	= "Nice All RT Tasks",
+	.enable_mask	= SYSRQ_ENABLE_RTNICE,
+};
+
+/* Key Operations table and lock */
+static DEFINE_SPINLOCK(sysrq_key_table_lock);
+
+static const struct sysrq_key_op *sysrq_key_table[62] = {
+	&sysrq_loglevel_op,		/* 0 */
+	&sysrq_loglevel_op,		/* 1 */
+	&sysrq_loglevel_op,		/* 2 */
+	&sysrq_loglevel_op,		/* 3 */
+	&sysrq_loglevel_op,		/* 4 */
+	&sysrq_loglevel_op,		/* 5 */
+	&sysrq_loglevel_op,		/* 6 */
+	&sysrq_loglevel_op,		/* 7 */
+	&sysrq_loglevel_op,		/* 8 */
+	&sysrq_loglevel_op,		/* 9 */
+
+	/*
+	 * a: Don't use for system provided sysrqs, it is handled specially on
+	 * sparc and will never arrive.
+	 */
+	NULL,				/* a */
+	&sysrq_reboot_op,		/* b */
+	&sysrq_crash_op,		/* c */
+	&sysrq_showlocks_op,		/* d */
+	&sysrq_term_op,			/* e */
+	&sysrq_moom_op,			/* f */
+	/* g: May be registered for the kernel debugger */
+	NULL,				/* g */
+	NULL,				/* h - reserved for help */
+	&sysrq_kill_op,			/* i */
+	&sysrq_thaw_op,			/* j */
+	&sysrq_SAK_op,			/* k */
+	&sysrq_showallcpus_op,		/* l */
+	&sysrq_showmem_op,		/* m */
+	&sysrq_unrt_op,			/* n */
+	/* o: This will often be registered as 'Off' at init time */
+	NULL,				/* o */
+	&sysrq_showregs_op,		/* p */
+	&sysrq_show_timers_op,		/* q */
+	&sysrq_unraw_op,		/* r */
+	&sysrq_sync_op,			/* s */
+	&sysrq_showstate_op,		/* t */
+	&sysrq_mountro_op,		/* u */
+	/* v: May be registered for frame buffer console restore */
+	NULL,				/* v */
+	&sysrq_showstate_blocked_op,	/* w */
+	/* x: May be registered on mips for TLB dump */
+	/* x: May be registered on ppc/powerpc for xmon */
+	/* x: May be registered on sparc64 for global PMU dump */
+	NULL,				/* x */
+	/* y: May be registered on sparc64 for global register dump */
+	NULL,				/* y */
+	&sysrq_ftrace_dump_op,		/* z */
+	NULL,				/* A */
+	NULL,				/* B */
+	NULL,				/* C */
+	NULL,				/* D */
+	NULL,				/* E */
+	NULL,				/* F */
+	NULL,				/* G */
+	NULL,				/* H */
+	NULL,				/* I */
+	NULL,				/* J */
+	NULL,				/* K */
+	NULL,				/* L */
+	NULL,				/* M */
+	NULL,				/* N */
+	NULL,				/* O */
+	NULL,				/* P */
+	NULL,				/* Q */
+	NULL,				/* R */
+	NULL,				/* S */
+	NULL,				/* T */
+	NULL,				/* U */
+	NULL,				/* V */
+	NULL,				/* W */
+	NULL,				/* X */
+	NULL,				/* Y */
+	NULL,				/* Z */
+};
+
+/* key2index calculation, -1 on invalid index */
+static int sysrq_key_table_key2index(u8 key)
+{
+	switch (key) {
+	case '0' ... '9':
+		return key - '0';
+	case 'a' ... 'z':
+		return key - 'a' + 10;
+	case 'A' ... 'Z':
+		return key - 'A' + 10 + 26;
+	default:
+		return -1;
+	}
+}
+
+/*
+ * get and put functions for the table, exposed to modules.
+ */
+static const struct sysrq_key_op *__sysrq_get_key_op(u8 key)
+{
+	const struct sysrq_key_op *op_p = NULL;
+	int i;
+
+	i = sysrq_key_table_key2index(key);
+	if (i != -1)
+		op_p = sysrq_key_table[i];
+
+	return op_p;
+}
+
+static void __sysrq_put_key_op(u8 key, const struct sysrq_key_op *op_p)
+{
+	int i = sysrq_key_table_key2index(key);
+
+	if (i != -1)
+		sysrq_key_table[i] = op_p;
+}
+
+void __handle_sysrq(u8 key, bool check_mask)
+{
+	const struct sysrq_key_op *op_p;
+	int orig_log_level;
+	int orig_suppress_printk;
+	int i;
+
+	orig_suppress_printk = suppress_printk;
+	suppress_printk = 0;
+
+	rcu_sysrq_start();
+	rcu_read_lock();
+	/*
+	 * Raise the apparent loglevel to maximum so that the sysrq header
+	 * is shown to provide the user with positive feedback.  We do not
+	 * simply emit this at KERN_EMERG as that would change message
+	 * routing in the consumers of /proc/kmsg.
+	 */
+	orig_log_level = console_loglevel;
+	console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
+
+	op_p = __sysrq_get_key_op(key);
+	if (op_p) {
+		/*
+		 * Should we check for enabled operations (/proc/sysrq-trigger
+		 * should not) and is the invoked operation enabled?
+		 */
+		if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
+			pr_info("%s\n", op_p->action_msg);
+			console_loglevel = orig_log_level;
+			op_p->handler(key);
+		} else {
+			pr_info("This sysrq operation is disabled.\n");
+			console_loglevel = orig_log_level;
+		}
+	} else {
+		pr_info("HELP : ");
+		/* Only print the help msg once per handler */
+		for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
+			if (sysrq_key_table[i]) {
+				int j;
+
+				for (j = 0; sysrq_key_table[i] !=
+						sysrq_key_table[j]; j++)
+					;
+				if (j != i)
+					continue;
+				pr_cont("%s ", sysrq_key_table[i]->help_msg);
+			}
+		}
+		pr_cont("\n");
+		console_loglevel = orig_log_level;
+	}
+	rcu_read_unlock();
+	rcu_sysrq_end();
+
+	suppress_printk = orig_suppress_printk;
+}
+
+void handle_sysrq(u8 key)
+{
+	if (sysrq_on())
+		__handle_sysrq(key, true);
+}
+EXPORT_SYMBOL(handle_sysrq);
+
+#ifdef CONFIG_INPUT
+static int sysrq_reset_downtime_ms;
+
+/* Simple translation table for the SysRq keys */
+static const unsigned char sysrq_xlate[KEY_CNT] =
+	"\000\0331234567890-=\177\t"                    /* 0x00 - 0x0f */
+	"qwertyuiop[]\r\000as"                          /* 0x10 - 0x1f */
+	"dfghjkl;'`\000\\zxcv"                          /* 0x20 - 0x2f */
+	"bnm,./\000*\000 \000\201\202\203\204\205"      /* 0x30 - 0x3f */
+	"\206\207\210\211\212\000\000789-456+1"         /* 0x40 - 0x4f */
+	"230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
+	"\r\000/";                                      /* 0x60 - 0x6f */
+
+struct sysrq_state {
+	struct input_handle handle;
+	struct work_struct reinject_work;
+	unsigned long key_down[BITS_TO_LONGS(KEY_CNT)];
+	unsigned int alt;
+	unsigned int alt_use;
+	unsigned int shift;
+	unsigned int shift_use;
+	bool active;
+	bool need_reinject;
+	bool reinjecting;
+
+	/* reset sequence handling */
+	bool reset_canceled;
+	bool reset_requested;
+	unsigned long reset_keybit[BITS_TO_LONGS(KEY_CNT)];
+	int reset_seq_len;
+	int reset_seq_cnt;
+	int reset_seq_version;
+	struct timer_list keyreset_timer;
+};
+
+#define SYSRQ_KEY_RESET_MAX	20 /* Should be plenty */
+static unsigned short sysrq_reset_seq[SYSRQ_KEY_RESET_MAX];
+static unsigned int sysrq_reset_seq_len;
+static unsigned int sysrq_reset_seq_version = 1;
+
+static void sysrq_parse_reset_sequence(struct sysrq_state *state)
+{
+	int i;
+	unsigned short key;
+
+	state->reset_seq_cnt = 0;
+
+	for (i = 0; i < sysrq_reset_seq_len; i++) {
+		key = sysrq_reset_seq[i];
+
+		if (key == KEY_RESERVED || key > KEY_MAX)
+			break;
+
+		__set_bit(key, state->reset_keybit);
+		state->reset_seq_len++;
+
+		if (test_bit(key, state->key_down))
+			state->reset_seq_cnt++;
+	}
+
+	/* Disable reset until old keys are not released */
+	state->reset_canceled = state->reset_seq_cnt != 0;
+
+	state->reset_seq_version = sysrq_reset_seq_version;
+}
+
+static void sysrq_do_reset(struct timer_list *t)
+{
+	struct sysrq_state *state = from_timer(state, t, keyreset_timer);
+
+	state->reset_requested = true;
+
+	orderly_reboot();
+}
+
+static void sysrq_handle_reset_request(struct sysrq_state *state)
+{
+	if (state->reset_requested)
+		__handle_sysrq(sysrq_xlate[KEY_B], false);
+
+	if (sysrq_reset_downtime_ms)
+		mod_timer(&state->keyreset_timer,
+			jiffies + msecs_to_jiffies(sysrq_reset_downtime_ms));
+	else
+		sysrq_do_reset(&state->keyreset_timer);
+}
+
+static void sysrq_detect_reset_sequence(struct sysrq_state *state,
+					unsigned int code, int value)
+{
+	if (!test_bit(code, state->reset_keybit)) {
+		/*
+		 * Pressing any key _not_ in reset sequence cancels
+		 * the reset sequence.  Also cancelling the timer in
+		 * case additional keys were pressed after a reset
+		 * has been requested.
+		 */
+		if (value && state->reset_seq_cnt) {
+			state->reset_canceled = true;
+			del_timer(&state->keyreset_timer);
+		}
+	} else if (value == 0) {
+		/*
+		 * Key release - all keys in the reset sequence need
+		 * to be pressed and held for the reset timeout
+		 * to hold.
+		 */
+		del_timer(&state->keyreset_timer);
+
+		if (--state->reset_seq_cnt == 0)
+			state->reset_canceled = false;
+	} else if (value == 1) {
+		/* key press, not autorepeat */
+		if (++state->reset_seq_cnt == state->reset_seq_len &&
+		    !state->reset_canceled) {
+			sysrq_handle_reset_request(state);
+		}
+	}
+}
+
+#ifdef CONFIG_OF
+static void sysrq_of_get_keyreset_config(void)
+{
+	u32 key;
+	struct device_node *np;
+	struct property *prop;
+	const __be32 *p;
+
+	np = of_find_node_by_path("/chosen/linux,sysrq-reset-seq");
+	if (!np) {
+		pr_debug("No sysrq node found");
+		return;
+	}
+
+	/* Reset in case a __weak definition was present */
+	sysrq_reset_seq_len = 0;
+
+	of_property_for_each_u32(np, "keyset", prop, p, key) {
+		if (key == KEY_RESERVED || key > KEY_MAX ||
+		    sysrq_reset_seq_len == SYSRQ_KEY_RESET_MAX)
+			break;
+
+		sysrq_reset_seq[sysrq_reset_seq_len++] = (unsigned short)key;
+	}
+
+	/* Get reset timeout if any. */
+	of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms);
+
+	of_node_put(np);
+}
+#else
+static void sysrq_of_get_keyreset_config(void)
+{
+}
+#endif
+
+static void sysrq_reinject_alt_sysrq(struct work_struct *work)
+{
+	struct sysrq_state *sysrq =
+			container_of(work, struct sysrq_state, reinject_work);
+	struct input_handle *handle = &sysrq->handle;
+	unsigned int alt_code = sysrq->alt_use;
+
+	if (sysrq->need_reinject) {
+		/* we do not want the assignment to be reordered */
+		sysrq->reinjecting = true;
+		mb();
+
+		/* Simulate press and release of Alt + SysRq */
+		input_inject_event(handle, EV_KEY, alt_code, 1);
+		input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1);
+		input_inject_event(handle, EV_SYN, SYN_REPORT, 1);
+
+		input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0);
+		input_inject_event(handle, EV_KEY, alt_code, 0);
+		input_inject_event(handle, EV_SYN, SYN_REPORT, 1);
+
+		mb();
+		sysrq->reinjecting = false;
+	}
+}
+
+static bool sysrq_handle_keypress(struct sysrq_state *sysrq,
+				  unsigned int code, int value)
+{
+	bool was_active = sysrq->active;
+	bool suppress;
+
+	switch (code) {
+
+	case KEY_LEFTALT:
+	case KEY_RIGHTALT:
+		if (!value) {
+			/* One of ALTs is being released */
+			if (sysrq->active && code == sysrq->alt_use)
+				sysrq->active = false;
+
+			sysrq->alt = KEY_RESERVED;
+
+		} else if (value != 2) {
+			sysrq->alt = code;
+			sysrq->need_reinject = false;
+		}
+		break;
+
+	case KEY_LEFTSHIFT:
+	case KEY_RIGHTSHIFT:
+		if (!value)
+			sysrq->shift = KEY_RESERVED;
+		else if (value != 2)
+			sysrq->shift = code;
+		if (sysrq->active)
+			sysrq->shift_use = sysrq->shift;
+		break;
+
+	case KEY_SYSRQ:
+		if (value == 1 && sysrq->alt != KEY_RESERVED) {
+			sysrq->active = true;
+			sysrq->alt_use = sysrq->alt;
+			/* either RESERVED (for released) or actual code */
+			sysrq->shift_use = sysrq->shift;
+			/*
+			 * If nothing else will be pressed we'll need
+			 * to re-inject Alt-SysRq keysroke.
+			 */
+			sysrq->need_reinject = true;
+		}
+
+		/*
+		 * Pretend that sysrq was never pressed at all. This
+		 * is needed to properly handle KGDB which will try
+		 * to release all keys after exiting debugger. If we
+		 * do not clear key bit it KGDB will end up sending
+		 * release events for Alt and SysRq, potentially
+		 * triggering print screen function.
+		 */
+		if (sysrq->active)
+			clear_bit(KEY_SYSRQ, sysrq->handle.dev->key);
+
+		break;
+
+	default:
+		if (sysrq->active && value && value != 2) {
+			unsigned char c = sysrq_xlate[code];
+
+			sysrq->need_reinject = false;
+			if (sysrq->shift_use != KEY_RESERVED)
+				c = toupper(c);
+			__handle_sysrq(c, true);
+		}
+		break;
+	}
+
+	suppress = sysrq->active;
+
+	if (!sysrq->active) {
+
+		/*
+		 * See if reset sequence has changed since the last time.
+		 */
+		if (sysrq->reset_seq_version != sysrq_reset_seq_version)
+			sysrq_parse_reset_sequence(sysrq);
+
+		/*
+		 * If we are not suppressing key presses keep track of
+		 * keyboard state so we can release keys that have been
+		 * pressed before entering SysRq mode.
+		 */
+		if (value)
+			set_bit(code, sysrq->key_down);
+		else
+			clear_bit(code, sysrq->key_down);
+
+		if (was_active)
+			schedule_work(&sysrq->reinject_work);
+
+		/* Check for reset sequence */
+		sysrq_detect_reset_sequence(sysrq, code, value);
+
+	} else if (value == 0 && test_and_clear_bit(code, sysrq->key_down)) {
+		/*
+		 * Pass on release events for keys that was pressed before
+		 * entering SysRq mode.
+		 */
+		suppress = false;
+	}
+
+	return suppress;
+}
+
+static bool sysrq_filter(struct input_handle *handle,
+			 unsigned int type, unsigned int code, int value)
+{
+	struct sysrq_state *sysrq = handle->private;
+	bool suppress;
+
+	/*
+	 * Do not filter anything if we are in the process of re-injecting
+	 * Alt+SysRq combination.
+	 */
+	if (sysrq->reinjecting)
+		return false;
+
+	switch (type) {
+
+	case EV_SYN:
+		suppress = false;
+		break;
+
+	case EV_KEY:
+		suppress = sysrq_handle_keypress(sysrq, code, value);
+		break;
+
+	default:
+		suppress = sysrq->active;
+		break;
+	}
+
+	return suppress;
+}
+
+static int sysrq_connect(struct input_handler *handler,
+			 struct input_dev *dev,
+			 const struct input_device_id *id)
+{
+	struct sysrq_state *sysrq;
+	int error;
+
+	sysrq = kzalloc(sizeof(struct sysrq_state), GFP_KERNEL);
+	if (!sysrq)
+		return -ENOMEM;
+
+	INIT_WORK(&sysrq->reinject_work, sysrq_reinject_alt_sysrq);
+
+	sysrq->handle.dev = dev;
+	sysrq->handle.handler = handler;
+	sysrq->handle.name = "sysrq";
+	sysrq->handle.private = sysrq;
+	timer_setup(&sysrq->keyreset_timer, sysrq_do_reset, 0);
+
+	error = input_register_handle(&sysrq->handle);
+	if (error) {
+		pr_err("Failed to register input sysrq handler, error %d\n",
+			error);
+		goto err_free;
+	}
+
+	error = input_open_device(&sysrq->handle);
+	if (error) {
+		pr_err("Failed to open input device, error %d\n", error);
+		goto err_unregister;
+	}
+
+	return 0;
+
+ err_unregister:
+	input_unregister_handle(&sysrq->handle);
+ err_free:
+	kfree(sysrq);
+	return error;
+}
+
+static void sysrq_disconnect(struct input_handle *handle)
+{
+	struct sysrq_state *sysrq = handle->private;
+
+	input_close_device(handle);
+	cancel_work_sync(&sysrq->reinject_work);
+	timer_shutdown_sync(&sysrq->keyreset_timer);
+	input_unregister_handle(handle);
+	kfree(sysrq);
+}
+
+/*
+ * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all
+ * keyboards have SysRq key predefined and so user may add it to keymap
+ * later, but we expect all such keyboards to have left alt.
+ */
+static const struct input_device_id sysrq_ids[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+				INPUT_DEVICE_ID_MATCH_KEYBIT,
+		.evbit = { [BIT_WORD(EV_KEY)] = BIT_MASK(EV_KEY) },
+		.keybit = { [BIT_WORD(KEY_LEFTALT)] = BIT_MASK(KEY_LEFTALT) },
+	},
+	{ },
+};
+
+static struct input_handler sysrq_handler = {
+	.filter		= sysrq_filter,
+	.connect	= sysrq_connect,
+	.disconnect	= sysrq_disconnect,
+	.name		= "sysrq",
+	.id_table	= sysrq_ids,
+};
+
+static inline void sysrq_register_handler(void)
+{
+	int error;
+
+	sysrq_of_get_keyreset_config();
+
+	error = input_register_handler(&sysrq_handler);
+	if (error)
+		pr_err("Failed to register input handler, error %d", error);
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+	input_unregister_handler(&sysrq_handler);
+}
+
+static int sysrq_reset_seq_param_set(const char *buffer,
+				     const struct kernel_param *kp)
+{
+	unsigned long val;
+	int error;
+
+	error = kstrtoul(buffer, 0, &val);
+	if (error < 0)
+		return error;
+
+	if (val > KEY_MAX)
+		return -EINVAL;
+
+	*((unsigned short *)kp->arg) = val;
+	sysrq_reset_seq_version++;
+
+	return 0;
+}
+
+static const struct kernel_param_ops param_ops_sysrq_reset_seq = {
+	.get	= param_get_ushort,
+	.set	= sysrq_reset_seq_param_set,
+};
+
+#define param_check_sysrq_reset_seq(name, p)	\
+	__param_check(name, p, unsigned short)
+
+/*
+ * not really modular, but the easiest way to keep compat with existing
+ * bootargs behaviour is to continue using module_param here.
+ */
+module_param_array_named(reset_seq, sysrq_reset_seq, sysrq_reset_seq,
+			 &sysrq_reset_seq_len, 0644);
+
+module_param_named(sysrq_downtime_ms, sysrq_reset_downtime_ms, int, 0644);
+
+#else
+
+static inline void sysrq_register_handler(void)
+{
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+}
+
+#endif /* CONFIG_INPUT */
+
+int sysrq_toggle_support(int enable_mask)
+{
+	bool was_enabled = sysrq_on();
+
+	sysrq_enabled = enable_mask;
+
+	if (was_enabled != sysrq_on()) {
+		if (sysrq_on())
+			sysrq_register_handler();
+		else
+			sysrq_unregister_handler();
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sysrq_toggle_support);
+
+static int __sysrq_swap_key_ops(u8 key, const struct sysrq_key_op *insert_op_p,
+				const struct sysrq_key_op *remove_op_p)
+{
+	int retval;
+
+	spin_lock(&sysrq_key_table_lock);
+	if (__sysrq_get_key_op(key) == remove_op_p) {
+		__sysrq_put_key_op(key, insert_op_p);
+		retval = 0;
+	} else {
+		retval = -1;
+	}
+	spin_unlock(&sysrq_key_table_lock);
+
+	/*
+	 * A concurrent __handle_sysrq either got the old op or the new op.
+	 * Wait for it to go away before returning, so the code for an old
+	 * op is not freed (eg. on module unload) while it is in use.
+	 */
+	synchronize_rcu();
+
+	return retval;
+}
+
+int register_sysrq_key(u8 key, const struct sysrq_key_op *op_p)
+{
+	return __sysrq_swap_key_ops(key, op_p, NULL);
+}
+EXPORT_SYMBOL(register_sysrq_key);
+
+int unregister_sysrq_key(u8 key, const struct sysrq_key_op *op_p)
+{
+	return __sysrq_swap_key_ops(key, NULL, op_p);
+}
+EXPORT_SYMBOL(unregister_sysrq_key);
+
+#ifdef CONFIG_PROC_FS
+/*
+ * writing 'C' to /proc/sysrq-trigger is like sysrq-C
+ */
+static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	if (count) {
+		char c;
+
+		if (get_user(c, buf))
+			return -EFAULT;
+		__handle_sysrq(c, false);
+	}
+
+	return count;
+}
+
+static const struct proc_ops sysrq_trigger_proc_ops = {
+	.proc_write	= write_sysrq_trigger,
+	.proc_lseek	= noop_llseek,
+};
+
+static void sysrq_init_procfs(void)
+{
+	if (!proc_create("sysrq-trigger", S_IWUSR, NULL,
+			 &sysrq_trigger_proc_ops))
+		pr_err("Failed to register proc interface\n");
+}
+
+#else
+
+static inline void sysrq_init_procfs(void)
+{
+}
+
+#endif /* CONFIG_PROC_FS */
+
+static int __init sysrq_init(void)
+{
+	sysrq_init_procfs();
+
+	if (sysrq_on())
+		sysrq_register_handler();
+
+	return 0;
+}
+device_initcall(sysrq_init);
diff --git a/drivers/tty/tty.h b/drivers/tty/tty.h
new file mode 100644
index 000000000..50862f982
--- /dev/null
+++ b/drivers/tty/tty.h
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * TTY core internal functions
+ */
+
+#ifndef _TTY_INTERNAL_H
+#define _TTY_INTERNAL_H
+
+#define tty_msg(fn, tty, f, ...) \
+	fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
+
+#define tty_debug(tty, f, ...)	tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
+#define tty_notice(tty, f, ...)	tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
+#define tty_warn(tty, f, ...)	tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
+#define tty_err(tty, f, ...)	tty_msg(pr_err, tty, f, ##__VA_ARGS__)
+
+#define tty_info_ratelimited(tty, f, ...) \
+		tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
+
+/*
+ * Lock subclasses for tty locks
+ *
+ * TTY_LOCK_NORMAL is for normal ttys and master ptys.
+ * TTY_LOCK_SLAVE is for slave ptys only.
+ *
+ * Lock subclasses are necessary for handling nested locking with pty pairs.
+ * tty locks which use nested locking:
+ *
+ * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
+ *		  The stable lock order is master pty first, then slave pty.
+ * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
+ *		   Subclassing this lock enables the slave pty to hold its
+ *		   termios_rwsem when claiming the master tty_buffer lock.
+ * tty_buffer lock - slave ptys can claim nested buffer lock when handling
+ *		     signal chars. The stable lock order is slave pty, then
+ *		     master.
+ */
+enum {
+	TTY_LOCK_NORMAL = 0,
+	TTY_LOCK_SLAVE,
+};
+
+/* Values for tty->flow_change */
+#define TTY_THROTTLE_SAFE	1
+#define TTY_UNTHROTTLE_SAFE	2
+
+static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
+{
+	tty->flow_change = val;
+}
+
+static inline void tty_set_flow_change(struct tty_struct *tty, int val)
+{
+	tty->flow_change = val;
+	smp_mb();
+}
+
+int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
+void tty_ldisc_unlock(struct tty_struct *tty);
+
+int __tty_check_change(struct tty_struct *tty, int sig);
+int tty_check_change(struct tty_struct *tty);
+void __stop_tty(struct tty_struct *tty);
+void __start_tty(struct tty_struct *tty);
+void tty_write_unlock(struct tty_struct *tty);
+int tty_write_lock(struct tty_struct *tty, bool ndelay);
+void tty_vhangup_session(struct tty_struct *tty);
+void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
+int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
+void session_clear_tty(struct pid *session);
+void tty_buffer_free_all(struct tty_port *port);
+void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
+void tty_buffer_init(struct tty_port *port);
+void tty_buffer_set_lock_subclass(struct tty_port *port);
+bool tty_buffer_restart_work(struct tty_port *port);
+bool tty_buffer_cancel_work(struct tty_port *port);
+void tty_buffer_flush_work(struct tty_port *port);
+speed_t tty_termios_input_baud_rate(const struct ktermios *termios);
+void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
+int tty_ldisc_reinit(struct tty_struct *tty, int disc);
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
+		       struct file *file, unsigned int cmd, unsigned long arg);
+void tty_default_fops(struct file_operations *fops);
+struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
+int tty_alloc_file(struct file *file);
+void tty_add_file(struct tty_struct *tty, struct file *file);
+void tty_free_file(struct file *file);
+int tty_release(struct inode *inode, struct file *filp);
+
+#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
+
+int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
+void tty_ldisc_release(struct tty_struct *tty);
+int __must_check tty_ldisc_init(struct tty_struct *tty);
+void tty_ldisc_deinit(struct tty_struct *tty);
+
+extern int tty_ldisc_autoload;
+
+/* tty_audit.c */
+#ifdef CONFIG_AUDIT
+void tty_audit_add_data(const struct tty_struct *tty, const void *data,
+			size_t size);
+void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch);
+#else
+static inline void tty_audit_add_data(const struct tty_struct *tty,
+				      const void *data, size_t size)
+{
+}
+static inline void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
+{
+}
+#endif
+
+ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
+
+int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
+					   const u8 *chars, size_t cnt);
+
+#endif
diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
new file mode 100644
index 000000000..1d81eeefb
--- /dev/null
+++ b/drivers/tty/tty_audit.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Creating audit events from TTY input.
+ *
+ * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
+ *
+ * Authors: Miloslav Trmac <mitr@redhat.com>
+ */
+
+#include <linux/audit.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include "tty.h"
+
+struct tty_audit_buf {
+	struct mutex mutex;	/* Protects all data below */
+	dev_t dev;		/* The TTY which the data is from */
+	bool icanon;
+	size_t valid;
+	u8 *data;		/* Allocated size N_TTY_BUF_SIZE */
+};
+
+static struct tty_audit_buf *tty_audit_buf_ref(void)
+{
+	struct tty_audit_buf *buf;
+
+	buf = current->signal->tty_audit_buf;
+	WARN_ON(buf == ERR_PTR(-ESRCH));
+	return buf;
+}
+
+static struct tty_audit_buf *tty_audit_buf_alloc(void)
+{
+	struct tty_audit_buf *buf;
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		goto err;
+
+	buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+	if (!buf->data)
+		goto err_buf;
+
+	mutex_init(&buf->mutex);
+
+	return buf;
+
+err_buf:
+	kfree(buf);
+err:
+	return NULL;
+}
+
+static void tty_audit_buf_free(struct tty_audit_buf *buf)
+{
+	WARN_ON(buf->valid != 0);
+	kfree(buf->data);
+	kfree(buf);
+}
+
+static void tty_audit_log(const char *description, dev_t dev,
+			  const u8 *data, size_t size)
+{
+	struct audit_buffer *ab;
+	pid_t pid = task_pid_nr(current);
+	uid_t uid = from_kuid(&init_user_ns, task_uid(current));
+	uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
+	unsigned int sessionid = audit_get_sessionid(current);
+	char name[TASK_COMM_LEN];
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_TTY);
+	if (!ab)
+		return;
+
+	audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d minor=%d comm=",
+			 description, pid, uid, loginuid, sessionid,
+			 MAJOR(dev), MINOR(dev));
+	get_task_comm(name, current);
+	audit_log_untrustedstring(ab, name);
+	audit_log_format(ab, " data=");
+	audit_log_n_hex(ab, data, size);
+	audit_log_end(ab);
+}
+
+/*
+ *	tty_audit_buf_push	-	Push buffered data out
+ *
+ *	Generate an audit message from the contents of @buf, which is owned by
+ *	the current task.  @buf->mutex must be locked.
+ */
+static void tty_audit_buf_push(struct tty_audit_buf *buf)
+{
+	if (buf->valid == 0)
+		return;
+	if (audit_enabled == AUDIT_OFF) {
+		buf->valid = 0;
+		return;
+	}
+	tty_audit_log("tty", buf->dev, buf->data, buf->valid);
+	buf->valid = 0;
+}
+
+/**
+ *	tty_audit_exit	-	Handle a task exit
+ *
+ *	Make sure all buffered data is written out and deallocate the buffer.
+ *	Only needs to be called if current->signal->tty_audit_buf != %NULL.
+ *
+ *	The process is single-threaded at this point; no other threads share
+ *	current->signal.
+ */
+void tty_audit_exit(void)
+{
+	struct tty_audit_buf *buf;
+
+	buf = xchg(&current->signal->tty_audit_buf, ERR_PTR(-ESRCH));
+	if (!buf)
+		return;
+
+	tty_audit_buf_push(buf);
+	tty_audit_buf_free(buf);
+}
+
+/*
+ *	tty_audit_fork	-	Copy TTY audit state for a new task
+ *
+ *	Set up TTY audit state in @sig from current.  @sig needs no locking.
+ */
+void tty_audit_fork(struct signal_struct *sig)
+{
+	sig->audit_tty = current->signal->audit_tty;
+}
+
+/*
+ *	tty_audit_tiocsti	-	Log TIOCSTI
+ */
+void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
+{
+	dev_t dev;
+
+	dev = MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+	if (tty_audit_push())
+		return;
+
+	if (audit_enabled)
+		tty_audit_log("ioctl=TIOCSTI", dev, &ch, 1);
+}
+
+/*
+ *	tty_audit_push	-	Flush current's pending audit data
+ *
+ *	Returns 0 if success, -EPERM if tty audit is disabled
+ */
+int tty_audit_push(void)
+{
+	struct tty_audit_buf *buf;
+
+	if (~current->signal->audit_tty & AUDIT_TTY_ENABLE)
+		return -EPERM;
+
+	buf = tty_audit_buf_ref();
+	if (!IS_ERR_OR_NULL(buf)) {
+		mutex_lock(&buf->mutex);
+		tty_audit_buf_push(buf);
+		mutex_unlock(&buf->mutex);
+	}
+	return 0;
+}
+
+/*
+ *	tty_audit_buf_get	-	Get an audit buffer.
+ *
+ *	Get an audit buffer, allocate it if necessary.  Return %NULL
+ *	if out of memory or ERR_PTR(-ESRCH) if tty_audit_exit() has already
+ *	occurred.  Otherwise, return a new reference to the buffer.
+ */
+static struct tty_audit_buf *tty_audit_buf_get(void)
+{
+	struct tty_audit_buf *buf;
+
+	buf = tty_audit_buf_ref();
+	if (buf)
+		return buf;
+
+	buf = tty_audit_buf_alloc();
+	if (buf == NULL) {
+		audit_log_lost("out of memory in TTY auditing");
+		return NULL;
+	}
+
+	/* Race to use this buffer, free it if another wins */
+	if (cmpxchg(&current->signal->tty_audit_buf, NULL, buf) != NULL)
+		tty_audit_buf_free(buf);
+	return tty_audit_buf_ref();
+}
+
+/*
+ *	tty_audit_add_data	-	Add data for TTY auditing.
+ *
+ *	Audit @data of @size from @tty, if necessary.
+ */
+void tty_audit_add_data(const struct tty_struct *tty, const void *data,
+			size_t size)
+{
+	struct tty_audit_buf *buf;
+	unsigned int audit_tty;
+	bool icanon = L_ICANON(tty);
+	dev_t dev;
+
+	audit_tty = READ_ONCE(current->signal->audit_tty);
+	if (~audit_tty & AUDIT_TTY_ENABLE)
+		return;
+
+	if (unlikely(size == 0))
+		return;
+
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY
+	    && tty->driver->subtype == PTY_TYPE_MASTER)
+		return;
+
+	if ((~audit_tty & AUDIT_TTY_LOG_PASSWD) && icanon && !L_ECHO(tty))
+		return;
+
+	buf = tty_audit_buf_get();
+	if (IS_ERR_OR_NULL(buf))
+		return;
+
+	mutex_lock(&buf->mutex);
+	dev = MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+	if (buf->dev != dev || buf->icanon != icanon) {
+		tty_audit_buf_push(buf);
+		buf->dev = dev;
+		buf->icanon = icanon;
+	}
+	do {
+		size_t run;
+
+		run = N_TTY_BUF_SIZE - buf->valid;
+		if (run > size)
+			run = size;
+		memcpy(buf->data + buf->valid, data, run);
+		buf->valid += run;
+		data += run;
+		size -= run;
+		if (buf->valid == N_TTY_BUF_SIZE)
+			tty_audit_buf_push(buf);
+	} while (size != 0);
+	mutex_unlock(&buf->mutex);
+}
diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c
new file mode 100644
index 000000000..f9b49939c
--- /dev/null
+++ b/drivers/tty/tty_baudrate.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/termios.h>
+#include <linux/tty.h>
+#include <linux/export.h>
+#include "tty.h"
+
+
+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static const speed_t baud_table[] = {
+	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
+	4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+	76800, 153600, 307200, 614400, 921600, 500000, 576000,
+	1000000, 1152000, 1500000, 2000000
+#else
+	500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+	2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+static const tcflag_t baud_bits[] = {
+	B0, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400,
+	B4800, B9600, B19200, B38400, B57600, B115200, B230400, B460800,
+#ifdef __sparc__
+	B76800, B153600, B307200, B614400, B921600, B500000, B576000,
+	B1000000, B1152000, B1500000, B2000000
+#else
+	B500000, B576000, B921600, B1000000, B1152000, B1500000, B2000000,
+	B2500000, B3000000, B3500000, B4000000
+#endif
+};
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ *	tty_termios_baud_rate
+ *	@termios: termios structure
+ *
+ *	Convert termios baud rate data into a speed. This should be called
+ *	with the termios lock held if this termios is a terminal termios
+ *	structure. Device drivers can call this function but should use
+ *	->c_[io]speed directly as they are updated.
+ *
+ *	Locking: none
+ */
+
+speed_t tty_termios_baud_rate(const struct ktermios *termios)
+{
+	unsigned int cbaud;
+
+	cbaud = termios->c_cflag & CBAUD;
+
+	/* Magic token for arbitrary speed via c_ispeed/c_ospeed */
+	if (cbaud == BOTHER)
+		return termios->c_ospeed;
+
+	if (cbaud & CBAUDEX) {
+		cbaud &= ~CBAUDEX;
+		cbaud += 15;
+	}
+	return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ *	tty_termios_input_baud_rate
+ *	@termios: termios structure
+ *
+ *	Convert termios baud rate data into a speed. This should be called
+ *	with the termios lock held if this termios is a terminal termios
+ *	structure. Device drivers can call this function but should use
+ *	->c_[io]speed directly as they are updated.
+ *
+ *	Locking: none
+ */
+
+speed_t tty_termios_input_baud_rate(const struct ktermios *termios)
+{
+	unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
+
+	if (cbaud == B0)
+		return tty_termios_baud_rate(termios);
+
+	/* Magic token for arbitrary speed via c_ispeed */
+	if (cbaud == BOTHER)
+		return termios->c_ispeed;
+
+	if (cbaud & CBAUDEX) {
+		cbaud &= ~CBAUDEX;
+		cbaud += 15;
+	}
+	return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+/**
+ *	tty_termios_encode_baud_rate
+ *	@termios: ktermios structure holding user requested state
+ *	@ibaud: input speed
+ *	@obaud: output speed
+ *
+ *	Encode the speeds set into the passed termios structure. This is
+ *	used as a library helper for drivers so that they can report back
+ *	the actual speed selected when it differs from the speed requested
+ *
+ *	For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ *	we need to carefully set the bits when the user does not get the
+ *	desired speed. We allow small margins and preserve as much of possible
+ *	of the input intent to keep compatibility.
+ *
+ *	Locking: Caller should hold termios lock. This is already held
+ *	when calling this function from the driver termios handler.
+ *
+ *	The ifdefs deal with platforms whose owners have yet to update them
+ *	and will all go away once this is done.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios,
+				  speed_t ibaud, speed_t obaud)
+{
+	int i = 0;
+	int ifound = -1, ofound = -1;
+	int iclose = ibaud/50, oclose = obaud/50;
+	int ibinput = 0;
+
+	if (obaud == 0)			/* CD dropped */
+		ibaud = 0;		/* Clear ibaud to be sure */
+
+	termios->c_ispeed = ibaud;
+	termios->c_ospeed = obaud;
+
+	if (((termios->c_cflag >> IBSHIFT) & CBAUD) != B0)
+		ibinput = 1;	/* An input speed was specified */
+
+	/* If the user asked for a precise weird speed give a precise weird
+	 * answer. If they asked for a Bfoo speed they may have problems
+	 * digesting non-exact replies so fuzz a bit.
+	 */
+
+	if ((termios->c_cflag & CBAUD) == BOTHER) {
+		oclose = 0;
+		if (!ibinput)
+			iclose = 0;
+	}
+	if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+		iclose = 0;
+
+	termios->c_cflag &= ~CBAUD;
+	termios->c_cflag &= ~(CBAUD << IBSHIFT);
+
+	/*
+	 *	Our goal is to find a close match to the standard baud rate
+	 *	returned. Walk the baud rate table and if we get a very close
+	 *	match then report back the speed as a POSIX Bxxxx value by
+	 *	preference
+	 */
+
+	do {
+		if (obaud - oclose <= baud_table[i] &&
+		    obaud + oclose >= baud_table[i]) {
+			termios->c_cflag |= baud_bits[i];
+			ofound = i;
+		}
+		if (ibaud - iclose <= baud_table[i] &&
+		    ibaud + iclose >= baud_table[i]) {
+			/* For the case input == output don't set IBAUD bits
+			 * if the user didn't do so.
+			 */
+			if (ofound == i && !ibinput) {
+				ifound  = i;
+			} else {
+				ifound = i;
+				termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+			}
+		}
+	} while (++i < n_baud_table);
+
+	/* If we found no match then use BOTHER. */
+	if (ofound == -1)
+		termios->c_cflag |= BOTHER;
+	/* Set exact input bits only if the input and output differ or the
+	 * user already did.
+	 */
+	if (ifound == -1 && (ibaud != obaud || ibinput))
+		termios->c_cflag |= (BOTHER << IBSHIFT);
+}
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+/**
+ *	tty_encode_baud_rate		-	set baud rate of the tty
+ *	@tty:   terminal device
+ *	@ibaud: input baud rate
+ *	@obaud: output baud rate
+ *
+ *	Update the current termios data for the tty with the new speed
+ *	settings. The caller must hold the termios_rwsem for the tty in
+ *	question.
+ */
+
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
+{
+	tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
+}
+EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
new file mode 100644
index 000000000..5f6d0cf67
--- /dev/null
+++ b/drivers/tty/tty_buffer.c
@@ -0,0 +1,628 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tty buffer allocation management
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/minmax.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/ratelimit.h>
+#include "tty.h"
+
+#define MIN_TTYB_SIZE	256
+#define TTYB_ALIGN_MASK	0xff
+
+/*
+ * Byte threshold to limit memory consumption for flip buffers.
+ * The actual memory limit is > 2x this amount.
+ */
+#define TTYB_DEFAULT_MEM_LIMIT	(640 * 1024UL)
+
+/*
+ * We default to dicing tty buffer allocations to this many characters
+ * in order to avoid multiple page allocations. We know the size of
+ * tty_buffer itself but it must also be taken into account that the
+ * buffer is 256 byte aligned. See tty_buffer_find for the allocation
+ * logic this must match.
+ */
+
+#define TTY_BUFFER_PAGE	(((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~TTYB_ALIGN_MASK)
+
+/**
+ * tty_buffer_lock_exclusive	-	gain exclusive access to buffer
+ * @port: tty port owning the flip buffer
+ *
+ * Guarantees safe use of the &tty_ldisc_ops.receive_buf() method by excluding
+ * the buffer work and any pending flush from using the flip buffer. Data can
+ * continue to be added concurrently to the flip buffer from the driver side.
+ *
+ * See also tty_buffer_unlock_exclusive().
+ */
+void tty_buffer_lock_exclusive(struct tty_port *port)
+{
+	struct tty_bufhead *buf = &port->buf;
+
+	atomic_inc(&buf->priority);
+	mutex_lock(&buf->lock);
+}
+EXPORT_SYMBOL_GPL(tty_buffer_lock_exclusive);
+
+/**
+ * tty_buffer_unlock_exclusive	-	release exclusive access
+ * @port: tty port owning the flip buffer
+ *
+ * The buffer work is restarted if there is data in the flip buffer.
+ *
+ * See also tty_buffer_lock_exclusive().
+ */
+void tty_buffer_unlock_exclusive(struct tty_port *port)
+{
+	struct tty_bufhead *buf = &port->buf;
+	int restart;
+
+	restart = buf->head->commit != buf->head->read;
+
+	atomic_dec(&buf->priority);
+	mutex_unlock(&buf->lock);
+	if (restart)
+		queue_work(system_unbound_wq, &buf->work);
+}
+EXPORT_SYMBOL_GPL(tty_buffer_unlock_exclusive);
+
+/**
+ * tty_buffer_space_avail	-	return unused buffer space
+ * @port: tty port owning the flip buffer
+ *
+ * Returns: the # of bytes which can be written by the driver without reaching
+ * the buffer limit.
+ *
+ * Note: this does not guarantee that memory is available to write the returned
+ * # of bytes (use tty_prepare_flip_string() to pre-allocate if memory
+ * guarantee is required).
+ */
+unsigned int tty_buffer_space_avail(struct tty_port *port)
+{
+	int space = port->buf.mem_limit - atomic_read(&port->buf.mem_used);
+
+	return max(space, 0);
+}
+EXPORT_SYMBOL_GPL(tty_buffer_space_avail);
+
+static void tty_buffer_reset(struct tty_buffer *p, size_t size)
+{
+	p->used = 0;
+	p->size = size;
+	p->next = NULL;
+	p->commit = 0;
+	p->lookahead = 0;
+	p->read = 0;
+	p->flags = true;
+}
+
+/**
+ * tty_buffer_free_all		-	free buffers used by a tty
+ * @port: tty port to free from
+ *
+ * Remove all the buffers pending on a tty whether queued with data or in the
+ * free ring. Must be called when the tty is no longer in use.
+ */
+void tty_buffer_free_all(struct tty_port *port)
+{
+	struct tty_bufhead *buf = &port->buf;
+	struct tty_buffer *p, *next;
+	struct llist_node *llist;
+	unsigned int freed = 0;
+	int still_used;
+
+	while ((p = buf->head) != NULL) {
+		buf->head = p->next;
+		freed += p->size;
+		if (p->size > 0)
+			kfree(p);
+	}
+	llist = llist_del_all(&buf->free);
+	llist_for_each_entry_safe(p, next, llist, free)
+		kfree(p);
+
+	tty_buffer_reset(&buf->sentinel, 0);
+	buf->head = &buf->sentinel;
+	buf->tail = &buf->sentinel;
+
+	still_used = atomic_xchg(&buf->mem_used, 0);
+	WARN(still_used != freed, "we still have not freed %d bytes!",
+			still_used - freed);
+}
+
+/**
+ * tty_buffer_alloc	-	allocate a tty buffer
+ * @port: tty port
+ * @size: desired size (characters)
+ *
+ * Allocate a new tty buffer to hold the desired number of characters. We
+ * round our buffers off in 256 character chunks to get better allocation
+ * behaviour.
+ *
+ * Returns: %NULL if out of memory or the allocation would exceed the per
+ * device queue.
+ */
+static struct tty_buffer *tty_buffer_alloc(struct tty_port *port, size_t size)
+{
+	struct llist_node *free;
+	struct tty_buffer *p;
+
+	/* Round the buffer size out */
+	size = __ALIGN_MASK(size, TTYB_ALIGN_MASK);
+
+	if (size <= MIN_TTYB_SIZE) {
+		free = llist_del_first(&port->buf.free);
+		if (free) {
+			p = llist_entry(free, struct tty_buffer, free);
+			goto found;
+		}
+	}
+
+	/* Should possibly check if this fails for the largest buffer we
+	 * have queued and recycle that ?
+	 */
+	if (atomic_read(&port->buf.mem_used) > port->buf.mem_limit)
+		return NULL;
+	p = kmalloc(struct_size(p, data, 2 * size), GFP_ATOMIC | __GFP_NOWARN);
+	if (p == NULL)
+		return NULL;
+
+found:
+	tty_buffer_reset(p, size);
+	atomic_add(size, &port->buf.mem_used);
+	return p;
+}
+
+/**
+ * tty_buffer_free		-	free a tty buffer
+ * @port: tty port owning the buffer
+ * @b: the buffer to free
+ *
+ * Free a tty buffer, or add it to the free list according to our internal
+ * strategy.
+ */
+static void tty_buffer_free(struct tty_port *port, struct tty_buffer *b)
+{
+	struct tty_bufhead *buf = &port->buf;
+
+	/* Dumb strategy for now - should keep some stats */
+	WARN_ON(atomic_sub_return(b->size, &buf->mem_used) < 0);
+
+	if (b->size > MIN_TTYB_SIZE)
+		kfree(b);
+	else if (b->size > 0)
+		llist_add(&b->free, &buf->free);
+}
+
+/**
+ * tty_buffer_flush		-	flush full tty buffers
+ * @tty: tty to flush
+ * @ld: optional ldisc ptr (must be referenced)
+ *
+ * Flush all the buffers containing receive data. If @ld != %NULL, flush the
+ * ldisc input buffer.
+ *
+ * Locking: takes buffer lock to ensure single-threaded flip buffer 'consumer'.
+ */
+void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	struct tty_port *port = tty->port;
+	struct tty_bufhead *buf = &port->buf;
+	struct tty_buffer *next;
+
+	atomic_inc(&buf->priority);
+
+	mutex_lock(&buf->lock);
+	/* paired w/ release in __tty_buffer_request_room; ensures there are
+	 * no pending memory accesses to the freed buffer
+	 */
+	while ((next = smp_load_acquire(&buf->head->next)) != NULL) {
+		tty_buffer_free(port, buf->head);
+		buf->head = next;
+	}
+	buf->head->read = buf->head->commit;
+	buf->head->lookahead = buf->head->read;
+
+	if (ld && ld->ops->flush_buffer)
+		ld->ops->flush_buffer(tty);
+
+	atomic_dec(&buf->priority);
+	mutex_unlock(&buf->lock);
+}
+
+/**
+ * __tty_buffer_request_room	-	grow tty buffer if needed
+ * @port: tty port
+ * @size: size desired
+ * @flags: buffer has to store flags along character data
+ *
+ * Make at least @size bytes of linear space available for the tty buffer.
+ *
+ * Will change over to a new buffer if the current buffer is encoded as
+ * %TTY_NORMAL (so has no flags buffer) and the new buffer requires a flags
+ * buffer.
+ *
+ * Returns: the size we managed to find.
+ */
+static int __tty_buffer_request_room(struct tty_port *port, size_t size,
+				     bool flags)
+{
+	struct tty_bufhead *buf = &port->buf;
+	struct tty_buffer *n, *b = buf->tail;
+	size_t left = (b->flags ? 1 : 2) * b->size - b->used;
+	bool change = !b->flags && flags;
+
+	if (!change && left >= size)
+		return size;
+
+	/* This is the slow path - looking for new buffers to use */
+	n = tty_buffer_alloc(port, size);
+	if (n == NULL)
+		return change ? 0 : left;
+
+	n->flags = flags;
+	buf->tail = n;
+	/*
+	 * Paired w/ acquire in flush_to_ldisc() and lookahead_bufs()
+	 * ensures they see all buffer data.
+	 */
+	smp_store_release(&b->commit, b->used);
+	/*
+	 * Paired w/ acquire in flush_to_ldisc() and lookahead_bufs()
+	 * ensures the latest commit value can be read before the head
+	 * is advanced to the next buffer.
+	 */
+	smp_store_release(&b->next, n);
+
+	return size;
+}
+
+int tty_buffer_request_room(struct tty_port *port, size_t size)
+{
+	return __tty_buffer_request_room(port, size, true);
+}
+EXPORT_SYMBOL_GPL(tty_buffer_request_room);
+
+size_t __tty_insert_flip_string_flags(struct tty_port *port, const u8 *chars,
+				      const u8 *flags, bool mutable_flags,
+				      size_t size)
+{
+	bool need_flags = mutable_flags || flags[0] != TTY_NORMAL;
+	size_t copied = 0;
+
+	do {
+		size_t goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
+		size_t space = __tty_buffer_request_room(port, goal, need_flags);
+		struct tty_buffer *tb = port->buf.tail;
+
+		if (unlikely(space == 0))
+			break;
+
+		memcpy(char_buf_ptr(tb, tb->used), chars, space);
+
+		if (mutable_flags) {
+			memcpy(flag_buf_ptr(tb, tb->used), flags, space);
+			flags += space;
+		} else if (tb->flags) {
+			memset(flag_buf_ptr(tb, tb->used), flags[0], space);
+		} else {
+			/* tb->flags should be available once requested */
+			WARN_ON_ONCE(need_flags);
+		}
+
+		tb->used += space;
+		copied += space;
+		chars += space;
+
+		/* There is a small chance that we need to split the data over
+		 * several buffers. If this is the case we must loop.
+		 */
+	} while (unlikely(size > copied));
+
+	return copied;
+}
+EXPORT_SYMBOL(__tty_insert_flip_string_flags);
+
+/**
+ * tty_prepare_flip_string	-	make room for characters
+ * @port: tty port
+ * @chars: return pointer for character write area
+ * @size: desired size
+ *
+ * Prepare a block of space in the buffer for data.
+ *
+ * This is used for drivers that need their own block copy routines into the
+ * buffer. There is no guarantee the buffer is a DMA target!
+ *
+ * Returns: the length available and buffer pointer (@chars) to the space which
+ * is now allocated and accounted for as ready for normal characters.
+ */
+size_t tty_prepare_flip_string(struct tty_port *port, u8 **chars, size_t size)
+{
+	size_t space = __tty_buffer_request_room(port, size, false);
+
+	if (likely(space)) {
+		struct tty_buffer *tb = port->buf.tail;
+
+		*chars = char_buf_ptr(tb, tb->used);
+		if (tb->flags)
+			memset(flag_buf_ptr(tb, tb->used), TTY_NORMAL, space);
+		tb->used += space;
+	}
+
+	return space;
+}
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
+
+/**
+ * tty_ldisc_receive_buf	-	forward data to line discipline
+ * @ld: line discipline to process input
+ * @p: char buffer
+ * @f: %TTY_NORMAL, %TTY_BREAK, etc. flags buffer
+ * @count: number of bytes to process
+ *
+ * Callers other than flush_to_ldisc() need to exclude the kworker from
+ * concurrent use of the line discipline, see paste_selection().
+ *
+ * Returns: the number of bytes processed.
+ */
+size_t tty_ldisc_receive_buf(struct tty_ldisc *ld, const u8 *p, const u8 *f,
+			     size_t count)
+{
+	if (ld->ops->receive_buf2)
+		count = ld->ops->receive_buf2(ld->tty, p, f, count);
+	else {
+		count = min_t(size_t, count, ld->tty->receive_room);
+		if (count && ld->ops->receive_buf)
+			ld->ops->receive_buf(ld->tty, p, f, count);
+	}
+	return count;
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_receive_buf);
+
+static void lookahead_bufs(struct tty_port *port, struct tty_buffer *head)
+{
+	head->lookahead = max(head->lookahead, head->read);
+
+	while (head) {
+		struct tty_buffer *next;
+		unsigned int count;
+
+		/*
+		 * Paired w/ release in __tty_buffer_request_room();
+		 * ensures commit value read is not stale if the head
+		 * is advancing to the next buffer.
+		 */
+		next = smp_load_acquire(&head->next);
+		/*
+		 * Paired w/ release in __tty_buffer_request_room() or in
+		 * tty_buffer_flush(); ensures we see the committed buffer data.
+		 */
+		count = smp_load_acquire(&head->commit) - head->lookahead;
+		if (!count) {
+			head = next;
+			continue;
+		}
+
+		if (port->client_ops->lookahead_buf) {
+			u8 *p, *f = NULL;
+
+			p = char_buf_ptr(head, head->lookahead);
+			if (head->flags)
+				f = flag_buf_ptr(head, head->lookahead);
+
+			port->client_ops->lookahead_buf(port, p, f, count);
+		}
+
+		head->lookahead += count;
+	}
+}
+
+static size_t
+receive_buf(struct tty_port *port, struct tty_buffer *head, size_t count)
+{
+	u8 *p = char_buf_ptr(head, head->read);
+	const u8 *f = NULL;
+	size_t n;
+
+	if (head->flags)
+		f = flag_buf_ptr(head, head->read);
+
+	n = port->client_ops->receive_buf(port, p, f, count);
+	if (n > 0)
+		memset(p, 0, n);
+	return n;
+}
+
+/**
+ * flush_to_ldisc		-	flush data from buffer to ldisc
+ * @work: tty structure passed from work queue.
+ *
+ * This routine is called out of the software interrupt to flush data from the
+ * buffer chain to the line discipline.
+ *
+ * The receive_buf() method is single threaded for each tty instance.
+ *
+ * Locking: takes buffer lock to ensure single-threaded flip buffer 'consumer'.
+ */
+static void flush_to_ldisc(struct work_struct *work)
+{
+	struct tty_port *port = container_of(work, struct tty_port, buf.work);
+	struct tty_bufhead *buf = &port->buf;
+
+	mutex_lock(&buf->lock);
+
+	while (1) {
+		struct tty_buffer *head = buf->head;
+		struct tty_buffer *next;
+		size_t count, rcvd;
+
+		/* Ldisc or user is trying to gain exclusive access */
+		if (atomic_read(&buf->priority))
+			break;
+
+		/* paired w/ release in __tty_buffer_request_room();
+		 * ensures commit value read is not stale if the head
+		 * is advancing to the next buffer
+		 */
+		next = smp_load_acquire(&head->next);
+		/* paired w/ release in __tty_buffer_request_room() or in
+		 * tty_buffer_flush(); ensures we see the committed buffer data
+		 */
+		count = smp_load_acquire(&head->commit) - head->read;
+		if (!count) {
+			if (next == NULL)
+				break;
+			buf->head = next;
+			tty_buffer_free(port, head);
+			continue;
+		}
+
+		rcvd = receive_buf(port, head, count);
+		head->read += rcvd;
+		if (rcvd < count)
+			lookahead_bufs(port, head);
+		if (!rcvd)
+			break;
+
+		if (need_resched())
+			cond_resched();
+	}
+
+	mutex_unlock(&buf->lock);
+
+}
+
+static inline void tty_flip_buffer_commit(struct tty_buffer *tail)
+{
+	/*
+	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees
+	 * buffer data.
+	 */
+	smp_store_release(&tail->commit, tail->used);
+}
+
+/**
+ * tty_flip_buffer_push		-	push terminal buffers
+ * @port: tty port to push
+ *
+ * Queue a push of the terminal flip buffers to the line discipline. Can be
+ * called from IRQ/atomic context.
+ *
+ * In the event of the queue being busy for flipping the work will be held off
+ * and retried later.
+ */
+void tty_flip_buffer_push(struct tty_port *port)
+{
+	struct tty_bufhead *buf = &port->buf;
+
+	tty_flip_buffer_commit(buf->tail);
+	queue_work(system_unbound_wq, &buf->work);
+}
+EXPORT_SYMBOL(tty_flip_buffer_push);
+
+/**
+ * tty_insert_flip_string_and_push_buffer - add characters to the tty buffer and
+ *	push
+ * @port: tty port
+ * @chars: characters
+ * @size: size
+ *
+ * The function combines tty_insert_flip_string() and tty_flip_buffer_push()
+ * with the exception of properly holding the @port->lock.
+ *
+ * To be used only internally (by pty currently).
+ *
+ * Returns: the number added.
+ */
+int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
+					   const u8 *chars, size_t size)
+{
+	struct tty_bufhead *buf = &port->buf;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	size = tty_insert_flip_string(port, chars, size);
+	if (size)
+		tty_flip_buffer_commit(buf->tail);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	queue_work(system_unbound_wq, &buf->work);
+
+	return size;
+}
+
+/**
+ * tty_buffer_init		-	prepare a tty buffer structure
+ * @port: tty port to initialise
+ *
+ * Set up the initial state of the buffer management for a tty device. Must be
+ * called before the other tty buffer functions are used.
+ */
+void tty_buffer_init(struct tty_port *port)
+{
+	struct tty_bufhead *buf = &port->buf;
+
+	mutex_init(&buf->lock);
+	tty_buffer_reset(&buf->sentinel, 0);
+	buf->head = &buf->sentinel;
+	buf->tail = &buf->sentinel;
+	init_llist_head(&buf->free);
+	atomic_set(&buf->mem_used, 0);
+	atomic_set(&buf->priority, 0);
+	INIT_WORK(&buf->work, flush_to_ldisc);
+	buf->mem_limit = TTYB_DEFAULT_MEM_LIMIT;
+}
+
+/**
+ * tty_buffer_set_limit		-	change the tty buffer memory limit
+ * @port: tty port to change
+ * @limit: memory limit to set
+ *
+ * Change the tty buffer memory limit.
+ *
+ * Must be called before the other tty buffer functions are used.
+ */
+int tty_buffer_set_limit(struct tty_port *port, int limit)
+{
+	if (limit < MIN_TTYB_SIZE)
+		return -EINVAL;
+	port->buf.mem_limit = limit;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tty_buffer_set_limit);
+
+/* slave ptys can claim nested buffer lock when handling BRK and INTR */
+void tty_buffer_set_lock_subclass(struct tty_port *port)
+{
+	lockdep_set_subclass(&port->buf.lock, TTY_LOCK_SLAVE);
+}
+
+bool tty_buffer_restart_work(struct tty_port *port)
+{
+	return queue_work(system_unbound_wq, &port->buf.work);
+}
+
+bool tty_buffer_cancel_work(struct tty_port *port)
+{
+	return cancel_work_sync(&port->buf.work);
+}
+
+void tty_buffer_flush_work(struct tty_port *port)
+{
+	flush_work(&port->buf.work);
+}
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
new file mode 100644
index 000000000..493fc4742
--- /dev/null
+++ b/drivers/tty/tty_io.c
@@ -0,0 +1,3644 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
+ * or rs-channels. It also implements echoing, cooked mode etc.
+ *
+ * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
+ *
+ * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
+ * tty_struct and tty_queue structures.  Previously there was an array
+ * of 256 tty_struct's which was statically allocated, and the
+ * tty_queue structures were allocated at boot time.  Both are now
+ * dynamically allocated only when the tty is open.
+ *
+ * Also restructured routines so that there is more of a separation
+ * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
+ * the low-level tty routines (serial.c, pty.c, console.c).  This
+ * makes for cleaner and more compact code.  -TYT, 9/17/92
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ *
+ * NOTE: pay no attention to the line discipline code (yet); its
+ * interface is still subject to change in this version...
+ * -- TYT, 1/31/92
+ *
+ * Added functionality to the OPOST tty handling.  No delays, but all
+ * other bits should be there.
+ *	-- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
+ *
+ * Rewrote canonical mode and added more termios flags.
+ *	-- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
+ *
+ * Reorganized FASYNC support so mouse code can share it.
+ *	-- ctm@ardi.com, 9Sep95
+ *
+ * New TIOCLINUX variants added.
+ *	-- mj@k332.feld.cvut.cz, 19-Nov-95
+ *
+ * Restrict vt switching via ioctl()
+ *      -- grif@cs.ucr.edu, 5-Dec-95
+ *
+ * Move console and virtual terminal code to more appropriate files,
+ * implement CONFIG_VT and generalize console device interface.
+ *	-- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
+ *
+ * Rewrote tty_init_dev and tty_release_dev to eliminate races.
+ *	-- Bill Hawes <whawes@star.net>, June 97
+ *
+ * Added devfs support.
+ *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
+ *
+ * Added support for a Unix98-style ptmx device.
+ *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ * Reduced memory usage for older ARM systems
+ *      -- Russell King <rmk@arm.linux.org.uk>
+ *
+ * Move do_SAK() into process context.  Less stack use in devfs functions.
+ * alloc_tty_struct() always uses kmalloc()
+ *			 -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/ppp-ioctl.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+#include <linux/serial.h>
+#include <linux/ratelimit.h>
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+#include <linux/termios_internal.h>
+#include <linux/fs.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+
+#include <linux/kmod.h>
+#include <linux/nsproxy.h>
+#include "tty.h"
+
+#undef TTY_DEBUG_HANGUP
+#ifdef TTY_DEBUG_HANGUP
+# define tty_debug_hangup(tty, f, args...)	tty_debug(tty, f, ##args)
+#else
+# define tty_debug_hangup(tty, f, args...)	do { } while (0)
+#endif
+
+#define TTY_PARANOIA_CHECK 1
+#define CHECK_TTY_COUNT 1
+
+struct ktermios tty_std_termios = {	/* for the benefit of tty drivers  */
+	.c_iflag = ICRNL | IXON,
+	.c_oflag = OPOST | ONLCR,
+	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
+	.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
+		   ECHOCTL | ECHOKE | IEXTEN,
+	.c_cc = INIT_C_CC,
+	.c_ispeed = 38400,
+	.c_ospeed = 38400,
+	/* .c_line = N_TTY, */
+};
+EXPORT_SYMBOL(tty_std_termios);
+
+/* This list gets poked at by procfs and various bits of boot up code. This
+ * could do with some rationalisation such as pulling the tty proc function
+ * into this file.
+ */
+
+LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
+
+/* Mutex to protect creating and releasing a tty */
+DEFINE_MUTEX(tty_mutex);
+
+static ssize_t tty_read(struct kiocb *, struct iov_iter *);
+static ssize_t tty_write(struct kiocb *, struct iov_iter *);
+static __poll_t tty_poll(struct file *, poll_table *);
+static int tty_open(struct inode *, struct file *);
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg);
+#else
+#define tty_compat_ioctl NULL
+#endif
+static int __tty_fasync(int fd, struct file *filp, int on);
+static int tty_fasync(int fd, struct file *filp, int on);
+static void release_tty(struct tty_struct *tty, int idx);
+
+/**
+ * free_tty_struct	-	free a disused tty
+ * @tty: tty struct to free
+ *
+ * Free the write buffers, tty queue and tty memory itself.
+ *
+ * Locking: none. Must be called after tty is definitely unused
+ */
+static void free_tty_struct(struct tty_struct *tty)
+{
+	tty_ldisc_deinit(tty);
+	put_device(tty->dev);
+	kvfree(tty->write_buf);
+	kfree(tty);
+}
+
+static inline struct tty_struct *file_tty(struct file *file)
+{
+	return ((struct tty_file_private *)file->private_data)->tty;
+}
+
+int tty_alloc_file(struct file *file)
+{
+	struct tty_file_private *priv;
+
+	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	file->private_data = priv;
+
+	return 0;
+}
+
+/* Associate a new file with the tty structure */
+void tty_add_file(struct tty_struct *tty, struct file *file)
+{
+	struct tty_file_private *priv = file->private_data;
+
+	priv->tty = tty;
+	priv->file = file;
+
+	spin_lock(&tty->files_lock);
+	list_add(&priv->list, &tty->tty_files);
+	spin_unlock(&tty->files_lock);
+}
+
+/**
+ * tty_free_file - free file->private_data
+ * @file: to free private_data of
+ *
+ * This shall be used only for fail path handling when tty_add_file was not
+ * called yet.
+ */
+void tty_free_file(struct file *file)
+{
+	struct tty_file_private *priv = file->private_data;
+
+	file->private_data = NULL;
+	kfree(priv);
+}
+
+/* Delete file from its tty */
+static void tty_del_file(struct file *file)
+{
+	struct tty_file_private *priv = file->private_data;
+	struct tty_struct *tty = priv->tty;
+
+	spin_lock(&tty->files_lock);
+	list_del(&priv->list);
+	spin_unlock(&tty->files_lock);
+	tty_free_file(file);
+}
+
+/**
+ * tty_name	-	return tty naming
+ * @tty: tty structure
+ *
+ * Convert a tty structure into a name. The name reflects the kernel naming
+ * policy and if udev is in use may not reflect user space
+ *
+ * Locking: none
+ */
+const char *tty_name(const struct tty_struct *tty)
+{
+	if (!tty) /* Hmm.  NULL pointer.  That's fun. */
+		return "NULL tty";
+	return tty->name;
+}
+EXPORT_SYMBOL(tty_name);
+
+const char *tty_driver_name(const struct tty_struct *tty)
+{
+	if (!tty || !tty->driver)
+		return "";
+	return tty->driver->name;
+}
+
+static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
+			      const char *routine)
+{
+#ifdef TTY_PARANOIA_CHECK
+	if (!tty) {
+		pr_warn("(%d:%d): %s: NULL tty\n",
+			imajor(inode), iminor(inode), routine);
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+/* Caller must hold tty_lock */
+static void check_tty_count(struct tty_struct *tty, const char *routine)
+{
+#ifdef CHECK_TTY_COUNT
+	struct list_head *p;
+	int count = 0, kopen_count = 0;
+
+	spin_lock(&tty->files_lock);
+	list_for_each(p, &tty->tty_files) {
+		count++;
+	}
+	spin_unlock(&tty->files_lock);
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_SLAVE &&
+	    tty->link && tty->link->count)
+		count++;
+	if (tty_port_kopened(tty->port))
+		kopen_count++;
+	if (tty->count != (count + kopen_count)) {
+		tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n",
+			 routine, tty->count, count, kopen_count);
+	}
+#endif
+}
+
+/**
+ * get_tty_driver		-	find device of a tty
+ * @device: device identifier
+ * @index: returns the index of the tty
+ *
+ * This routine returns a tty driver structure, given a device number and also
+ * passes back the index number.
+ *
+ * Locking: caller must hold tty_mutex
+ */
+static struct tty_driver *get_tty_driver(dev_t device, int *index)
+{
+	struct tty_driver *p;
+
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		dev_t base = MKDEV(p->major, p->minor_start);
+
+		if (device < base || device >= base + p->num)
+			continue;
+		*index = device - base;
+		return tty_driver_kref_get(p);
+	}
+	return NULL;
+}
+
+/**
+ * tty_dev_name_to_number	-	return dev_t for device name
+ * @name: user space name of device under /dev
+ * @number: pointer to dev_t that this function will populate
+ *
+ * This function converts device names like ttyS0 or ttyUSB1 into dev_t like
+ * (4, 64) or (188, 1). If no corresponding driver is registered then the
+ * function returns -%ENODEV.
+ *
+ * Locking: this acquires tty_mutex to protect the tty_drivers list from
+ *	being modified while we are traversing it, and makes sure to
+ *	release it before exiting.
+ */
+int tty_dev_name_to_number(const char *name, dev_t *number)
+{
+	struct tty_driver *p;
+	int ret;
+	int index, prefix_length = 0;
+	const char *str;
+
+	for (str = name; *str && !isdigit(*str); str++)
+		;
+
+	if (!*str)
+		return -EINVAL;
+
+	ret = kstrtoint(str, 10, &index);
+	if (ret)
+		return ret;
+
+	prefix_length = str - name;
+	mutex_lock(&tty_mutex);
+
+	list_for_each_entry(p, &tty_drivers, tty_drivers)
+		if (prefix_length == strlen(p->name) && strncmp(name,
+					p->name, prefix_length) == 0) {
+			if (index < p->num) {
+				*number = MKDEV(p->major, p->minor_start + index);
+				goto out;
+			}
+		}
+
+	/* if here then driver wasn't found */
+	ret = -ENODEV;
+out:
+	mutex_unlock(&tty_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tty_dev_name_to_number);
+
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ * tty_find_polling_driver	-	find device of a polled tty
+ * @name: name string to match
+ * @line: pointer to resulting tty line nr
+ *
+ * This routine returns a tty driver structure, given a name and the condition
+ * that the tty driver is capable of polled operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+	struct tty_driver *p, *res = NULL;
+	int tty_line = 0;
+	int len;
+	char *str, *stp;
+
+	for (str = name; *str; str++)
+		if ((*str >= '0' && *str <= '9') || *str == ',')
+			break;
+	if (!*str)
+		return NULL;
+
+	len = str - name;
+	tty_line = simple_strtoul(str, &str, 10);
+
+	mutex_lock(&tty_mutex);
+	/* Search through the tty devices to look for a match */
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		if (!len || strncmp(name, p->name, len) != 0)
+			continue;
+		stp = str;
+		if (*stp == ',')
+			stp++;
+		if (*stp == '\0')
+			stp = NULL;
+
+		if (tty_line >= 0 && tty_line < p->num && p->ops &&
+		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
+			res = tty_driver_kref_get(p);
+			*line = tty_line;
+			break;
+		}
+	}
+	mutex_unlock(&tty_mutex);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
+static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to)
+{
+	return 0;
+}
+
+static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from)
+{
+	return -EIO;
+}
+
+/* No kernel lock held - none needed ;) */
+static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait)
+{
+	return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM;
+}
+
+static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
+{
+	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static long hung_up_tty_compat_ioctl(struct file *file,
+				     unsigned int cmd, unsigned long arg)
+{
+	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static int hung_up_tty_fasync(int fd, struct file *file, int on)
+{
+	return -ENOTTY;
+}
+
+static void tty_show_fdinfo(struct seq_file *m, struct file *file)
+{
+	struct tty_struct *tty = file_tty(file);
+
+	if (tty && tty->ops && tty->ops->show_fdinfo)
+		tty->ops->show_fdinfo(tty, m);
+}
+
+static const struct file_operations tty_fops = {
+	.llseek		= no_llseek,
+	.read_iter	= tty_read,
+	.write_iter	= tty_write,
+	.splice_read	= copy_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.poll		= tty_poll,
+	.unlocked_ioctl	= tty_ioctl,
+	.compat_ioctl	= tty_compat_ioctl,
+	.open		= tty_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+	.show_fdinfo	= tty_show_fdinfo,
+};
+
+static const struct file_operations console_fops = {
+	.llseek		= no_llseek,
+	.read_iter	= tty_read,
+	.write_iter	= redirected_tty_write,
+	.splice_read	= copy_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.poll		= tty_poll,
+	.unlocked_ioctl	= tty_ioctl,
+	.compat_ioctl	= tty_compat_ioctl,
+	.open		= tty_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+};
+
+static const struct file_operations hung_up_tty_fops = {
+	.llseek		= no_llseek,
+	.read_iter	= hung_up_tty_read,
+	.write_iter	= hung_up_tty_write,
+	.poll		= hung_up_tty_poll,
+	.unlocked_ioctl	= hung_up_tty_ioctl,
+	.compat_ioctl	= hung_up_tty_compat_ioctl,
+	.release	= tty_release,
+	.fasync		= hung_up_tty_fasync,
+};
+
+static DEFINE_SPINLOCK(redirect_lock);
+static struct file *redirect;
+
+/**
+ * tty_wakeup	-	request more data
+ * @tty: terminal
+ *
+ * Internal and external helper for wakeups of tty. This function informs the
+ * line discipline if present that the driver is ready to receive more output
+ * data.
+ */
+void tty_wakeup(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+
+	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
+		ld = tty_ldisc_ref(tty);
+		if (ld) {
+			if (ld->ops->write_wakeup)
+				ld->ops->write_wakeup(tty);
+			tty_ldisc_deref(ld);
+		}
+	}
+	wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
+}
+EXPORT_SYMBOL_GPL(tty_wakeup);
+
+/**
+ * tty_release_redirect	-	Release a redirect on a pty if present
+ * @tty: tty device
+ *
+ * This is available to the pty code so if the master closes, if the slave is a
+ * redirect it can release the redirect.
+ */
+static struct file *tty_release_redirect(struct tty_struct *tty)
+{
+	struct file *f = NULL;
+
+	spin_lock(&redirect_lock);
+	if (redirect && file_tty(redirect) == tty) {
+		f = redirect;
+		redirect = NULL;
+	}
+	spin_unlock(&redirect_lock);
+
+	return f;
+}
+
+/**
+ * __tty_hangup		-	actual handler for hangup events
+ * @tty: tty device
+ * @exit_session: if non-zero, signal all foreground group processes
+ *
+ * This can be called by a "kworker" kernel thread. That is process synchronous
+ * but doesn't hold any locks, so we need to make sure we have the appropriate
+ * locks for what we're doing.
+ *
+ * The hangup event clears any pending redirections onto the hung up device. It
+ * ensures future writes will error and it does the needed line discipline
+ * hangup and signal delivery. The tty object itself remains intact.
+ *
+ * Locking:
+ *  * BTM
+ *
+ *   * redirect lock for undoing redirection
+ *   * file list lock for manipulating list of ttys
+ *   * tty_ldiscs_lock from called functions
+ *   * termios_rwsem resetting termios data
+ *   * tasklist_lock to walk task list for hangup event
+ *
+ *    * ->siglock to protect ->signal/->sighand
+ *
+ */
+static void __tty_hangup(struct tty_struct *tty, int exit_session)
+{
+	struct file *cons_filp = NULL;
+	struct file *filp, *f;
+	struct tty_file_private *priv;
+	int    closecount = 0, n;
+	int refs;
+
+	if (!tty)
+		return;
+
+	f = tty_release_redirect(tty);
+
+	tty_lock(tty);
+
+	if (test_bit(TTY_HUPPED, &tty->flags)) {
+		tty_unlock(tty);
+		return;
+	}
+
+	/*
+	 * Some console devices aren't actually hung up for technical and
+	 * historical reasons, which can lead to indefinite interruptible
+	 * sleep in n_tty_read().  The following explicitly tells
+	 * n_tty_read() to abort readers.
+	 */
+	set_bit(TTY_HUPPING, &tty->flags);
+
+	/* inuse_filps is protected by the single tty lock,
+	 * this really needs to change if we want to flush the
+	 * workqueue with the lock held.
+	 */
+	check_tty_count(tty, "tty_hangup");
+
+	spin_lock(&tty->files_lock);
+	/* This breaks for file handles being sent over AF_UNIX sockets ? */
+	list_for_each_entry(priv, &tty->tty_files, list) {
+		filp = priv->file;
+		if (filp->f_op->write_iter == redirected_tty_write)
+			cons_filp = filp;
+		if (filp->f_op->write_iter != tty_write)
+			continue;
+		closecount++;
+		__tty_fasync(-1, filp, 0);	/* can't block */
+		filp->f_op = &hung_up_tty_fops;
+	}
+	spin_unlock(&tty->files_lock);
+
+	refs = tty_signal_session_leader(tty, exit_session);
+	/* Account for the p->signal references we killed */
+	while (refs--)
+		tty_kref_put(tty);
+
+	tty_ldisc_hangup(tty, cons_filp != NULL);
+
+	spin_lock_irq(&tty->ctrl.lock);
+	clear_bit(TTY_THROTTLED, &tty->flags);
+	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	put_pid(tty->ctrl.session);
+	put_pid(tty->ctrl.pgrp);
+	tty->ctrl.session = NULL;
+	tty->ctrl.pgrp = NULL;
+	tty->ctrl.pktstatus = 0;
+	spin_unlock_irq(&tty->ctrl.lock);
+
+	/*
+	 * If one of the devices matches a console pointer, we
+	 * cannot just call hangup() because that will cause
+	 * tty->count and state->count to go out of sync.
+	 * So we just call close() the right number of times.
+	 */
+	if (cons_filp) {
+		if (tty->ops->close)
+			for (n = 0; n < closecount; n++)
+				tty->ops->close(tty, cons_filp);
+	} else if (tty->ops->hangup)
+		tty->ops->hangup(tty);
+	/*
+	 * We don't want to have driver/ldisc interactions beyond the ones
+	 * we did here. The driver layer expects no calls after ->hangup()
+	 * from the ldisc side, which is now guaranteed.
+	 */
+	set_bit(TTY_HUPPED, &tty->flags);
+	clear_bit(TTY_HUPPING, &tty->flags);
+	tty_unlock(tty);
+
+	if (f)
+		fput(f);
+}
+
+static void do_tty_hangup(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, hangup_work);
+
+	__tty_hangup(tty, 0);
+}
+
+/**
+ * tty_hangup		-	trigger a hangup event
+ * @tty: tty to hangup
+ *
+ * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a
+ * hangup sequence to run after this event.
+ */
+void tty_hangup(struct tty_struct *tty)
+{
+	tty_debug_hangup(tty, "hangup\n");
+	schedule_work(&tty->hangup_work);
+}
+EXPORT_SYMBOL(tty_hangup);
+
+/**
+ * tty_vhangup		-	process vhangup
+ * @tty: tty to hangup
+ *
+ * The user has asked via system call for the terminal to be hung up. We do
+ * this synchronously so that when the syscall returns the process is complete.
+ * That guarantee is necessary for security reasons.
+ */
+void tty_vhangup(struct tty_struct *tty)
+{
+	tty_debug_hangup(tty, "vhangup\n");
+	__tty_hangup(tty, 0);
+}
+EXPORT_SYMBOL(tty_vhangup);
+
+
+/**
+ * tty_vhangup_self	-	process vhangup for own ctty
+ *
+ * Perform a vhangup on the current controlling tty
+ */
+void tty_vhangup_self(void)
+{
+	struct tty_struct *tty;
+
+	tty = get_current_tty();
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+}
+
+/**
+ * tty_vhangup_session	-	hangup session leader exit
+ * @tty: tty to hangup
+ *
+ * The session leader is exiting and hanging up its controlling terminal.
+ * Every process in the foreground process group is signalled %SIGHUP.
+ *
+ * We do this synchronously so that when the syscall returns the process is
+ * complete. That guarantee is necessary for security reasons.
+ */
+void tty_vhangup_session(struct tty_struct *tty)
+{
+	tty_debug_hangup(tty, "session hangup\n");
+	__tty_hangup(tty, 1);
+}
+
+/**
+ * tty_hung_up_p	-	was tty hung up
+ * @filp: file pointer of tty
+ *
+ * Return: true if the tty has been subject to a vhangup or a carrier loss
+ */
+int tty_hung_up_p(struct file *filp)
+{
+	return (filp && filp->f_op == &hung_up_tty_fops);
+}
+EXPORT_SYMBOL(tty_hung_up_p);
+
+void __stop_tty(struct tty_struct *tty)
+{
+	if (tty->flow.stopped)
+		return;
+	tty->flow.stopped = true;
+	if (tty->ops->stop)
+		tty->ops->stop(tty);
+}
+
+/**
+ * stop_tty	-	propagate flow control
+ * @tty: tty to stop
+ *
+ * Perform flow control to the driver. May be called on an already stopped
+ * device and will not re-call the &tty_driver->stop() method.
+ *
+ * This functionality is used by both the line disciplines for halting incoming
+ * flow and by the driver. It may therefore be called from any context, may be
+ * under the tty %atomic_write_lock but not always.
+ *
+ * Locking:
+ *	flow.lock
+ */
+void stop_tty(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->flow.lock, flags);
+	__stop_tty(tty);
+	spin_unlock_irqrestore(&tty->flow.lock, flags);
+}
+EXPORT_SYMBOL(stop_tty);
+
+void __start_tty(struct tty_struct *tty)
+{
+	if (!tty->flow.stopped || tty->flow.tco_stopped)
+		return;
+	tty->flow.stopped = false;
+	if (tty->ops->start)
+		tty->ops->start(tty);
+	tty_wakeup(tty);
+}
+
+/**
+ * start_tty	-	propagate flow control
+ * @tty: tty to start
+ *
+ * Start a tty that has been stopped if at all possible. If @tty was previously
+ * stopped and is now being started, the &tty_driver->start() method is invoked
+ * and the line discipline woken.
+ *
+ * Locking:
+ *	flow.lock
+ */
+void start_tty(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->flow.lock, flags);
+	__start_tty(tty);
+	spin_unlock_irqrestore(&tty->flow.lock, flags);
+}
+EXPORT_SYMBOL(start_tty);
+
+static void tty_update_time(struct tty_struct *tty, bool mtime)
+{
+	time64_t sec = ktime_get_real_seconds();
+	struct tty_file_private *priv;
+
+	spin_lock(&tty->files_lock);
+	list_for_each_entry(priv, &tty->tty_files, list) {
+		struct inode *inode = file_inode(priv->file);
+		struct timespec64 *time = mtime ? &inode->i_mtime : &inode->i_atime;
+
+		/*
+		 * We only care if the two values differ in anything other than the
+		 * lower three bits (i.e every 8 seconds).  If so, then we can update
+		 * the time of the tty device, otherwise it could be construded as a
+		 * security leak to let userspace know the exact timing of the tty.
+		 */
+		if ((sec ^ time->tv_sec) & ~7)
+			time->tv_sec = sec;
+	}
+	spin_unlock(&tty->files_lock);
+}
+
+/*
+ * Iterate on the ldisc ->read() function until we've gotten all
+ * the data the ldisc has for us.
+ *
+ * The "cookie" is something that the ldisc read function can fill
+ * in to let us know that there is more data to be had.
+ *
+ * We promise to continue to call the ldisc until it stops returning
+ * data or clears the cookie. The cookie may be something that the
+ * ldisc maintains state for and needs to free.
+ */
+static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
+				struct file *file, struct iov_iter *to)
+{
+	void *cookie = NULL;
+	unsigned long offset = 0;
+	char kernel_buf[64];
+	ssize_t retval = 0;
+	size_t copied, count = iov_iter_count(to);
+
+	do {
+		ssize_t size = min(count, sizeof(kernel_buf));
+
+		size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset);
+		if (!size)
+			break;
+
+		if (size < 0) {
+			/* Did we have an earlier error (ie -EFAULT)? */
+			if (retval)
+				break;
+			retval = size;
+
+			/*
+			 * -EOVERFLOW means we didn't have enough space
+			 * for a whole packet, and we shouldn't return
+			 * a partial result.
+			 */
+			if (retval == -EOVERFLOW)
+				offset = 0;
+			break;
+		}
+
+		copied = copy_to_iter(kernel_buf, size, to);
+		offset += copied;
+		count -= copied;
+
+		/*
+		 * If the user copy failed, we still need to do another ->read()
+		 * call if we had a cookie to let the ldisc clear up.
+		 *
+		 * But make sure size is zeroed.
+		 */
+		if (unlikely(copied != size)) {
+			count = 0;
+			retval = -EFAULT;
+		}
+	} while (cookie);
+
+	/* We always clear tty buffer in case they contained passwords */
+	memzero_explicit(kernel_buf, sizeof(kernel_buf));
+	return offset ? offset : retval;
+}
+
+
+/**
+ * tty_read	-	read method for tty device files
+ * @iocb: kernel I/O control block
+ * @to: destination for the data read
+ *
+ * Perform the read system call function on this terminal device. Checks
+ * for hung up devices before calling the line discipline method.
+ *
+ * Locking:
+ *	Locks the line discipline internally while needed. Multiple read calls
+ *	may be outstanding in parallel.
+ */
+static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	struct tty_struct *tty = file_tty(file);
+	struct tty_ldisc *ld;
+	ssize_t ret;
+
+	if (tty_paranoia_check(tty, inode, "tty_read"))
+		return -EIO;
+	if (!tty || tty_io_error(tty))
+		return -EIO;
+
+	/* We want to wait for the line discipline to sort out in this
+	 * situation.
+	 */
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return hung_up_tty_read(iocb, to);
+	ret = -EIO;
+	if (ld->ops->read)
+		ret = iterate_tty_read(ld, tty, file, to);
+	tty_ldisc_deref(ld);
+
+	if (ret > 0)
+		tty_update_time(tty, false);
+
+	return ret;
+}
+
+void tty_write_unlock(struct tty_struct *tty)
+{
+	mutex_unlock(&tty->atomic_write_lock);
+	wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
+}
+
+int tty_write_lock(struct tty_struct *tty, bool ndelay)
+{
+	if (!mutex_trylock(&tty->atomic_write_lock)) {
+		if (ndelay)
+			return -EAGAIN;
+		if (mutex_lock_interruptible(&tty->atomic_write_lock))
+			return -ERESTARTSYS;
+	}
+	return 0;
+}
+
+/*
+ * Split writes up in sane blocksizes to avoid
+ * denial-of-service type attacks
+ */
+static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty,
+				 struct file *file, struct iov_iter *from)
+{
+	size_t chunk, count = iov_iter_count(from);
+	ssize_t ret, written = 0;
+
+	ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * We chunk up writes into a temporary buffer. This
+	 * simplifies low-level drivers immensely, since they
+	 * don't have locking issues and user mode accesses.
+	 *
+	 * But if TTY_NO_WRITE_SPLIT is set, we should use a
+	 * big chunk-size..
+	 *
+	 * The default chunk-size is 2kB, because the NTTY
+	 * layer has problems with bigger chunks. It will
+	 * claim to be able to handle more characters than
+	 * it actually does.
+	 */
+	chunk = 2048;
+	if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
+		chunk = 65536;
+	if (count < chunk)
+		chunk = count;
+
+	/* write_buf/write_cnt is protected by the atomic_write_lock mutex */
+	if (tty->write_cnt < chunk) {
+		unsigned char *buf_chunk;
+
+		if (chunk < 1024)
+			chunk = 1024;
+
+		buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+		if (!buf_chunk) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		kvfree(tty->write_buf);
+		tty->write_cnt = chunk;
+		tty->write_buf = buf_chunk;
+	}
+
+	/* Do the write .. */
+	for (;;) {
+		size_t size = min(chunk, count);
+
+		ret = -EFAULT;
+		if (copy_from_iter(tty->write_buf, size, from) != size)
+			break;
+
+		ret = ld->ops->write(tty, file, tty->write_buf, size);
+		if (ret <= 0)
+			break;
+
+		written += ret;
+		if (ret > size)
+			break;
+
+		/* FIXME! Have Al check this! */
+		if (ret != size)
+			iov_iter_revert(from, size-ret);
+
+		count -= ret;
+		if (!count)
+			break;
+		ret = -ERESTARTSYS;
+		if (signal_pending(current))
+			break;
+		cond_resched();
+	}
+	if (written) {
+		tty_update_time(tty, true);
+		ret = written;
+	}
+out:
+	tty_write_unlock(tty);
+	return ret;
+}
+
+/**
+ * tty_write_message - write a message to a certain tty, not just the console.
+ * @tty: the destination tty_struct
+ * @msg: the message to write
+ *
+ * This is used for messages that need to be redirected to a specific tty. We
+ * don't put it into the syslog queue right now maybe in the future if really
+ * needed.
+ *
+ * We must still hold the BTM and test the CLOSING flag for the moment.
+ */
+void tty_write_message(struct tty_struct *tty, char *msg)
+{
+	if (tty) {
+		mutex_lock(&tty->atomic_write_lock);
+		tty_lock(tty);
+		if (tty->ops->write && tty->count > 0)
+			tty->ops->write(tty, msg, strlen(msg));
+		tty_unlock(tty);
+		tty_write_unlock(tty);
+	}
+}
+
+static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from)
+{
+	struct tty_struct *tty = file_tty(file);
+	struct tty_ldisc *ld;
+	ssize_t ret;
+
+	if (tty_paranoia_check(tty, file_inode(file), "tty_write"))
+		return -EIO;
+	if (!tty || !tty->ops->write ||	tty_io_error(tty))
+		return -EIO;
+	/* Short term debug to catch buggy drivers */
+	if (tty->ops->write_room == NULL)
+		tty_err(tty, "missing write_room method\n");
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return hung_up_tty_write(iocb, from);
+	if (!ld->ops->write)
+		ret = -EIO;
+	else
+		ret = iterate_tty_write(ld, tty, file, from);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+/**
+ * tty_write		-	write method for tty device file
+ * @iocb: kernel I/O control block
+ * @from: iov_iter with data to write
+ *
+ * Write data to a tty device via the line discipline.
+ *
+ * Locking:
+ *	Locks the line discipline as required
+ *	Writes to the tty driver are serialized by the atomic_write_lock
+ *	and are then processed in chunks to the device. The line
+ *	discipline write method will not be invoked in parallel for
+ *	each device.
+ */
+static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from)
+{
+	return file_tty_write(iocb->ki_filp, iocb, from);
+}
+
+ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct file *p = NULL;
+
+	spin_lock(&redirect_lock);
+	if (redirect)
+		p = get_file(redirect);
+	spin_unlock(&redirect_lock);
+
+	/*
+	 * We know the redirected tty is just another tty, we can
+	 * call file_tty_write() directly with that file pointer.
+	 */
+	if (p) {
+		ssize_t res;
+
+		res = file_tty_write(p, iocb, iter);
+		fput(p);
+		return res;
+	}
+	return tty_write(iocb, iter);
+}
+
+/**
+ * tty_send_xchar	-	send priority character
+ * @tty: the tty to send to
+ * @ch: xchar to send
+ *
+ * Send a high priority character to the tty even if stopped.
+ *
+ * Locking: none for xchar method, write ordering for write method.
+ */
+int tty_send_xchar(struct tty_struct *tty, char ch)
+{
+	bool was_stopped = tty->flow.stopped;
+
+	if (tty->ops->send_xchar) {
+		down_read(&tty->termios_rwsem);
+		tty->ops->send_xchar(tty, ch);
+		up_read(&tty->termios_rwsem);
+		return 0;
+	}
+
+	if (tty_write_lock(tty, false) < 0)
+		return -ERESTARTSYS;
+
+	down_read(&tty->termios_rwsem);
+	if (was_stopped)
+		start_tty(tty);
+	tty->ops->write(tty, &ch, 1);
+	if (was_stopped)
+		stop_tty(tty);
+	up_read(&tty->termios_rwsem);
+	tty_write_unlock(tty);
+	return 0;
+}
+
+/**
+ * pty_line_name	-	generate name for a pty
+ * @driver: the tty driver in use
+ * @index: the minor number
+ * @p: output buffer of at least 6 bytes
+ *
+ * Generate a name from a @driver reference and write it to the output buffer
+ * @p.
+ *
+ * Locking: None
+ */
+static void pty_line_name(struct tty_driver *driver, int index, char *p)
+{
+	static const char ptychar[] = "pqrstuvwxyzabcde";
+	int i = index + driver->name_base;
+	/* ->name is initialized to "ttyp", but "tty" is expected */
+	sprintf(p, "%s%c%x",
+		driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
+		ptychar[i >> 4 & 0xf], i & 0xf);
+}
+
+/**
+ * tty_line_name	-	generate name for a tty
+ * @driver: the tty driver in use
+ * @index: the minor number
+ * @p: output buffer of at least 7 bytes
+ *
+ * Generate a name from a @driver reference and write it to the output buffer
+ * @p.
+ *
+ * Locking: None
+ */
+static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
+{
+	if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE)
+		return sprintf(p, "%s", driver->name);
+	else
+		return sprintf(p, "%s%d", driver->name,
+			       index + driver->name_base);
+}
+
+/**
+ * tty_driver_lookup_tty() - find an existing tty, if any
+ * @driver: the driver for the tty
+ * @file: file object
+ * @idx: the minor number
+ *
+ * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the
+ * driver lookup() method returns an error.
+ *
+ * Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
+ */
+static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
+		struct file *file, int idx)
+{
+	struct tty_struct *tty;
+
+	if (driver->ops->lookup) {
+		if (!file)
+			tty = ERR_PTR(-EIO);
+		else
+			tty = driver->ops->lookup(driver, file, idx);
+	} else {
+		if (idx >= driver->num)
+			return ERR_PTR(-EINVAL);
+		tty = driver->ttys[idx];
+	}
+	if (!IS_ERR(tty))
+		tty_kref_get(tty);
+	return tty;
+}
+
+/**
+ * tty_init_termios	-  helper for termios setup
+ * @tty: the tty to set up
+ *
+ * Initialise the termios structure for this tty. This runs under the
+ * %tty_mutex currently so we can be relaxed about ordering.
+ */
+void tty_init_termios(struct tty_struct *tty)
+{
+	struct ktermios *tp;
+	int idx = tty->index;
+
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+		tty->termios = tty->driver->init_termios;
+	else {
+		/* Check for lazy saved data */
+		tp = tty->driver->termios[idx];
+		if (tp != NULL) {
+			tty->termios = *tp;
+			tty->termios.c_line  = tty->driver->init_termios.c_line;
+		} else
+			tty->termios = tty->driver->init_termios;
+	}
+	/* Compatibility until drivers always set this */
+	tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
+	tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
+}
+EXPORT_SYMBOL_GPL(tty_init_termios);
+
+/**
+ * tty_standard_install - usual tty->ops->install
+ * @driver: the driver for the tty
+ * @tty: the tty
+ *
+ * If the @driver overrides @tty->ops->install, it still can call this function
+ * to perform the standard install operations.
+ */
+int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	tty_init_termios(tty);
+	tty_driver_kref_get(driver);
+	tty->count++;
+	driver->ttys[tty->index] = tty;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tty_standard_install);
+
+/**
+ * tty_driver_install_tty() - install a tty entry in the driver
+ * @driver: the driver for the tty
+ * @tty: the tty
+ *
+ * Install a tty object into the driver tables. The @tty->index field will be
+ * set by the time this is called. This method is responsible for ensuring any
+ * need additional structures are allocated and configured.
+ *
+ * Locking: tty_mutex for now
+ */
+static int tty_driver_install_tty(struct tty_driver *driver,
+						struct tty_struct *tty)
+{
+	return driver->ops->install ? driver->ops->install(driver, tty) :
+		tty_standard_install(driver, tty);
+}
+
+/**
+ * tty_driver_remove_tty() - remove a tty from the driver tables
+ * @driver: the driver for the tty
+ * @tty: tty to remove
+ *
+ * Remove a tty object from the driver tables. The tty->index field will be set
+ * by the time this is called.
+ *
+ * Locking: tty_mutex for now
+ */
+static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty)
+{
+	if (driver->ops->remove)
+		driver->ops->remove(driver, tty);
+	else
+		driver->ttys[tty->index] = NULL;
+}
+
+/**
+ * tty_reopen()	- fast re-open of an open tty
+ * @tty: the tty to open
+ *
+ * Re-opens on master ptys are not allowed and return -%EIO.
+ *
+ * Locking: Caller must hold tty_lock
+ * Return: 0 on success, -errno on error.
+ */
+static int tty_reopen(struct tty_struct *tty)
+{
+	struct tty_driver *driver = tty->driver;
+	struct tty_ldisc *ld;
+	int retval = 0;
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY &&
+	    driver->subtype == PTY_TYPE_MASTER)
+		return -EIO;
+
+	if (!tty->count)
+		return -EAGAIN;
+
+	if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
+		return -EBUSY;
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (ld) {
+		tty_ldisc_deref(ld);
+	} else {
+		retval = tty_ldisc_lock(tty, 5 * HZ);
+		if (retval)
+			return retval;
+
+		if (!tty->ldisc)
+			retval = tty_ldisc_reinit(tty, tty->termios.c_line);
+		tty_ldisc_unlock(tty);
+	}
+
+	if (retval == 0)
+		tty->count++;
+
+	return retval;
+}
+
+/**
+ * tty_init_dev		-	initialise a tty device
+ * @driver: tty driver we are opening a device on
+ * @idx: device index
+ *
+ * Prepare a tty device. This may not be a "new" clean device but could also be
+ * an active device. The pty drivers require special handling because of this.
+ *
+ * Locking:
+ *	The function is called under the tty_mutex, which protects us from the
+ *	tty struct or driver itself going away.
+ *
+ * On exit the tty device has the line discipline attached and a reference
+ * count of 1. If a pair was created for pty/tty use and the other was a pty
+ * master then it too has a reference count of 1.
+ *
+ * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed
+ * open. The new code protects the open with a mutex, so it's really quite
+ * straightforward. The mutex locking can probably be relaxed for the (most
+ * common) case of reopening a tty.
+ *
+ * Return: new tty structure
+ */
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
+{
+	struct tty_struct *tty;
+	int retval;
+
+	/*
+	 * First time open is complex, especially for PTY devices.
+	 * This code guarantees that either everything succeeds and the
+	 * TTY is ready for operation, or else the table slots are vacated
+	 * and the allocated memory released.  (Except that the termios
+	 * may be retained.)
+	 */
+
+	if (!try_module_get(driver->owner))
+		return ERR_PTR(-ENODEV);
+
+	tty = alloc_tty_struct(driver, idx);
+	if (!tty) {
+		retval = -ENOMEM;
+		goto err_module_put;
+	}
+
+	tty_lock(tty);
+	retval = tty_driver_install_tty(driver, tty);
+	if (retval < 0)
+		goto err_free_tty;
+
+	if (!tty->port)
+		tty->port = driver->ports[idx];
+
+	if (WARN_RATELIMIT(!tty->port,
+			"%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n",
+			__func__, tty->driver->name)) {
+		retval = -EINVAL;
+		goto err_release_lock;
+	}
+
+	retval = tty_ldisc_lock(tty, 5 * HZ);
+	if (retval)
+		goto err_release_lock;
+	tty->port->itty = tty;
+
+	/*
+	 * Structures all installed ... call the ldisc open routines.
+	 * If we fail here just call release_tty to clean up.  No need
+	 * to decrement the use counts, as release_tty doesn't care.
+	 */
+	retval = tty_ldisc_setup(tty, tty->link);
+	if (retval)
+		goto err_release_tty;
+	tty_ldisc_unlock(tty);
+	/* Return the tty locked so that it cannot vanish under the caller */
+	return tty;
+
+err_free_tty:
+	tty_unlock(tty);
+	free_tty_struct(tty);
+err_module_put:
+	module_put(driver->owner);
+	return ERR_PTR(retval);
+
+	/* call the tty release_tty routine to clean out this slot */
+err_release_tty:
+	tty_ldisc_unlock(tty);
+	tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n",
+			     retval, idx);
+err_release_lock:
+	tty_unlock(tty);
+	release_tty(tty, idx);
+	return ERR_PTR(retval);
+}
+
+/**
+ * tty_save_termios() - save tty termios data in driver table
+ * @tty: tty whose termios data to save
+ *
+ * Locking: Caller guarantees serialisation with tty_init_termios().
+ */
+void tty_save_termios(struct tty_struct *tty)
+{
+	struct ktermios *tp;
+	int idx = tty->index;
+
+	/* If the port is going to reset then it has no termios to save */
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+		return;
+
+	/* Stash the termios data */
+	tp = tty->driver->termios[idx];
+	if (tp == NULL) {
+		tp = kmalloc(sizeof(*tp), GFP_KERNEL);
+		if (tp == NULL)
+			return;
+		tty->driver->termios[idx] = tp;
+	}
+	*tp = tty->termios;
+}
+EXPORT_SYMBOL_GPL(tty_save_termios);
+
+/**
+ * tty_flush_works	-	flush all works of a tty/pty pair
+ * @tty: tty device to flush works for (or either end of a pty pair)
+ *
+ * Sync flush all works belonging to @tty (and the 'other' tty).
+ */
+static void tty_flush_works(struct tty_struct *tty)
+{
+	flush_work(&tty->SAK_work);
+	flush_work(&tty->hangup_work);
+	if (tty->link) {
+		flush_work(&tty->link->SAK_work);
+		flush_work(&tty->link->hangup_work);
+	}
+}
+
+/**
+ * release_one_tty	-	release tty structure memory
+ * @work: work of tty we are obliterating
+ *
+ * Releases memory associated with a tty structure, and clears out the
+ * driver table slots. This function is called when a device is no longer
+ * in use. It also gets called when setup of a device fails.
+ *
+ * Locking:
+ *	takes the file list lock internally when working on the list of ttys
+ *	that the driver keeps.
+ *
+ * This method gets called from a work queue so that the driver private
+ * cleanup ops can sleep (needed for USB at least)
+ */
+static void release_one_tty(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, hangup_work);
+	struct tty_driver *driver = tty->driver;
+	struct module *owner = driver->owner;
+
+	if (tty->ops->cleanup)
+		tty->ops->cleanup(tty);
+
+	tty_driver_kref_put(driver);
+	module_put(owner);
+
+	spin_lock(&tty->files_lock);
+	list_del_init(&tty->tty_files);
+	spin_unlock(&tty->files_lock);
+
+	put_pid(tty->ctrl.pgrp);
+	put_pid(tty->ctrl.session);
+	free_tty_struct(tty);
+}
+
+static void queue_release_one_tty(struct kref *kref)
+{
+	struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
+
+	/* The hangup queue is now free so we can reuse it rather than
+	 *  waste a chunk of memory for each port.
+	 */
+	INIT_WORK(&tty->hangup_work, release_one_tty);
+	schedule_work(&tty->hangup_work);
+}
+
+/**
+ * tty_kref_put		-	release a tty kref
+ * @tty: tty device
+ *
+ * Release a reference to the @tty device and if need be let the kref layer
+ * destruct the object for us.
+ */
+void tty_kref_put(struct tty_struct *tty)
+{
+	if (tty)
+		kref_put(&tty->kref, queue_release_one_tty);
+}
+EXPORT_SYMBOL(tty_kref_put);
+
+/**
+ * release_tty		-	release tty structure memory
+ * @tty: tty device release
+ * @idx: index of the tty device release
+ *
+ * Release both @tty and a possible linked partner (think pty pair),
+ * and decrement the refcount of the backing module.
+ *
+ * Locking:
+ *	tty_mutex
+ *	takes the file list lock internally when working on the list of ttys
+ *	that the driver keeps.
+ */
+static void release_tty(struct tty_struct *tty, int idx)
+{
+	/* This should always be true but check for the moment */
+	WARN_ON(tty->index != idx);
+	WARN_ON(!mutex_is_locked(&tty_mutex));
+	if (tty->ops->shutdown)
+		tty->ops->shutdown(tty);
+	tty_save_termios(tty);
+	tty_driver_remove_tty(tty->driver, tty);
+	if (tty->port)
+		tty->port->itty = NULL;
+	if (tty->link)
+		tty->link->port->itty = NULL;
+	if (tty->port)
+		tty_buffer_cancel_work(tty->port);
+	if (tty->link)
+		tty_buffer_cancel_work(tty->link->port);
+
+	tty_kref_put(tty->link);
+	tty_kref_put(tty);
+}
+
+/**
+ * tty_release_checks - check a tty before real release
+ * @tty: tty to check
+ * @idx: index of the tty
+ *
+ * Performs some paranoid checking before true release of the @tty. This is a
+ * no-op unless %TTY_PARANOIA_CHECK is defined.
+ */
+static int tty_release_checks(struct tty_struct *tty, int idx)
+{
+#ifdef TTY_PARANOIA_CHECK
+	if (idx < 0 || idx >= tty->driver->num) {
+		tty_debug(tty, "bad idx %d\n", idx);
+		return -1;
+	}
+
+	/* not much to check for devpts */
+	if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)
+		return 0;
+
+	if (tty != tty->driver->ttys[idx]) {
+		tty_debug(tty, "bad driver table[%d] = %p\n",
+			  idx, tty->driver->ttys[idx]);
+		return -1;
+	}
+	if (tty->driver->other) {
+		struct tty_struct *o_tty = tty->link;
+
+		if (o_tty != tty->driver->other->ttys[idx]) {
+			tty_debug(tty, "bad other table[%d] = %p\n",
+				  idx, tty->driver->other->ttys[idx]);
+			return -1;
+		}
+		if (o_tty->link != tty) {
+			tty_debug(tty, "bad link = %p\n", o_tty->link);
+			return -1;
+		}
+	}
+#endif
+	return 0;
+}
+
+/**
+ * tty_kclose      -       closes tty opened by tty_kopen
+ * @tty: tty device
+ *
+ * Performs the final steps to release and free a tty device. It is the same as
+ * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on
+ * @tty->port.
+ */
+void tty_kclose(struct tty_struct *tty)
+{
+	/*
+	 * Ask the line discipline code to release its structures
+	 */
+	tty_ldisc_release(tty);
+
+	/* Wait for pending work before tty destruction commences */
+	tty_flush_works(tty);
+
+	tty_debug_hangup(tty, "freeing structure\n");
+	/*
+	 * The release_tty function takes care of the details of clearing
+	 * the slots and preserving the termios structure.
+	 */
+	mutex_lock(&tty_mutex);
+	tty_port_set_kopened(tty->port, 0);
+	release_tty(tty, tty->index);
+	mutex_unlock(&tty_mutex);
+}
+EXPORT_SYMBOL_GPL(tty_kclose);
+
+/**
+ * tty_release_struct	-	release a tty struct
+ * @tty: tty device
+ * @idx: index of the tty
+ *
+ * Performs the final steps to release and free a tty device. It is roughly the
+ * reverse of tty_init_dev().
+ */
+void tty_release_struct(struct tty_struct *tty, int idx)
+{
+	/*
+	 * Ask the line discipline code to release its structures
+	 */
+	tty_ldisc_release(tty);
+
+	/* Wait for pending work before tty destruction commmences */
+	tty_flush_works(tty);
+
+	tty_debug_hangup(tty, "freeing structure\n");
+	/*
+	 * The release_tty function takes care of the details of clearing
+	 * the slots and preserving the termios structure.
+	 */
+	mutex_lock(&tty_mutex);
+	release_tty(tty, idx);
+	mutex_unlock(&tty_mutex);
+}
+EXPORT_SYMBOL_GPL(tty_release_struct);
+
+/**
+ * tty_release		-	vfs callback for close
+ * @inode: inode of tty
+ * @filp: file pointer for handle to tty
+ *
+ * Called the last time each file handle is closed that references this tty.
+ * There may however be several such references.
+ *
+ * Locking:
+ *	Takes BKL. See tty_release_dev().
+ *
+ * Even releasing the tty structures is a tricky business. We have to be very
+ * careful that the structures are all released at the same time, as interrupts
+ * might otherwise get the wrong pointers.
+ *
+ * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
+ * lead to double frees or releasing memory still in use.
+ */
+int tty_release(struct inode *inode, struct file *filp)
+{
+	struct tty_struct *tty = file_tty(filp);
+	struct tty_struct *o_tty = NULL;
+	int	do_sleep, final;
+	int	idx;
+	long	timeout = 0;
+	int	once = 1;
+
+	if (tty_paranoia_check(tty, inode, __func__))
+		return 0;
+
+	tty_lock(tty);
+	check_tty_count(tty, __func__);
+
+	__tty_fasync(-1, filp, 0);
+
+	idx = tty->index;
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		o_tty = tty->link;
+
+	if (tty_release_checks(tty, idx)) {
+		tty_unlock(tty);
+		return 0;
+	}
+
+	tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count);
+
+	if (tty->ops->close)
+		tty->ops->close(tty, filp);
+
+	/* If tty is pty master, lock the slave pty (stable lock order) */
+	tty_lock_slave(o_tty);
+
+	/*
+	 * Sanity check: if tty->count is going to zero, there shouldn't be
+	 * any waiters on tty->read_wait or tty->write_wait.  We test the
+	 * wait queues and kick everyone out _before_ actually starting to
+	 * close.  This ensures that we won't block while releasing the tty
+	 * structure.
+	 *
+	 * The test for the o_tty closing is necessary, since the master and
+	 * slave sides may close in any order.  If the slave side closes out
+	 * first, its count will be one, since the master side holds an open.
+	 * Thus this test wouldn't be triggered at the time the slave closed,
+	 * so we do it now.
+	 */
+	while (1) {
+		do_sleep = 0;
+
+		if (tty->count <= 1) {
+			if (waitqueue_active(&tty->read_wait)) {
+				wake_up_poll(&tty->read_wait, EPOLLIN);
+				do_sleep++;
+			}
+			if (waitqueue_active(&tty->write_wait)) {
+				wake_up_poll(&tty->write_wait, EPOLLOUT);
+				do_sleep++;
+			}
+		}
+		if (o_tty && o_tty->count <= 1) {
+			if (waitqueue_active(&o_tty->read_wait)) {
+				wake_up_poll(&o_tty->read_wait, EPOLLIN);
+				do_sleep++;
+			}
+			if (waitqueue_active(&o_tty->write_wait)) {
+				wake_up_poll(&o_tty->write_wait, EPOLLOUT);
+				do_sleep++;
+			}
+		}
+		if (!do_sleep)
+			break;
+
+		if (once) {
+			once = 0;
+			tty_warn(tty, "read/write wait queue active!\n");
+		}
+		schedule_timeout_killable(timeout);
+		if (timeout < 120 * HZ)
+			timeout = 2 * timeout + 1;
+		else
+			timeout = MAX_SCHEDULE_TIMEOUT;
+	}
+
+	if (o_tty) {
+		if (--o_tty->count < 0) {
+			tty_warn(tty, "bad slave count (%d)\n", o_tty->count);
+			o_tty->count = 0;
+		}
+	}
+	if (--tty->count < 0) {
+		tty_warn(tty, "bad tty->count (%d)\n", tty->count);
+		tty->count = 0;
+	}
+
+	/*
+	 * We've decremented tty->count, so we need to remove this file
+	 * descriptor off the tty->tty_files list; this serves two
+	 * purposes:
+	 *  - check_tty_count sees the correct number of file descriptors
+	 *    associated with this tty.
+	 *  - do_tty_hangup no longer sees this file descriptor as
+	 *    something that needs to be handled for hangups.
+	 */
+	tty_del_file(filp);
+
+	/*
+	 * Perform some housekeeping before deciding whether to return.
+	 *
+	 * If _either_ side is closing, make sure there aren't any
+	 * processes that still think tty or o_tty is their controlling
+	 * tty.
+	 */
+	if (!tty->count) {
+		read_lock(&tasklist_lock);
+		session_clear_tty(tty->ctrl.session);
+		if (o_tty)
+			session_clear_tty(o_tty->ctrl.session);
+		read_unlock(&tasklist_lock);
+	}
+
+	/* check whether both sides are closing ... */
+	final = !tty->count && !(o_tty && o_tty->count);
+
+	tty_unlock_slave(o_tty);
+	tty_unlock(tty);
+
+	/* At this point, the tty->count == 0 should ensure a dead tty
+	 * cannot be re-opened by a racing opener.
+	 */
+
+	if (!final)
+		return 0;
+
+	tty_debug_hangup(tty, "final close\n");
+
+	tty_release_struct(tty, idx);
+	return 0;
+}
+
+/**
+ * tty_open_current_tty - get locked tty of current task
+ * @device: device number
+ * @filp: file pointer to tty
+ * @return: locked tty of the current task iff @device is /dev/tty
+ *
+ * Performs a re-open of the current task's controlling tty.
+ *
+ * We cannot return driver and index like for the other nodes because devpts
+ * will not work then. It expects inodes to be from devpts FS.
+ */
+static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
+{
+	struct tty_struct *tty;
+	int retval;
+
+	if (device != MKDEV(TTYAUX_MAJOR, 0))
+		return NULL;
+
+	tty = get_current_tty();
+	if (!tty)
+		return ERR_PTR(-ENXIO);
+
+	filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
+	/* noctty = 1; */
+	tty_lock(tty);
+	tty_kref_put(tty);	/* safe to drop the kref now */
+
+	retval = tty_reopen(tty);
+	if (retval < 0) {
+		tty_unlock(tty);
+		tty = ERR_PTR(retval);
+	}
+	return tty;
+}
+
+/**
+ * tty_lookup_driver - lookup a tty driver for a given device file
+ * @device: device number
+ * @filp: file pointer to tty
+ * @index: index for the device in the @return driver
+ *
+ * If returned value is not erroneous, the caller is responsible to decrement
+ * the refcount by tty_driver_kref_put().
+ *
+ * Locking: %tty_mutex protects get_tty_driver()
+ *
+ * Return: driver for this inode (with increased refcount)
+ */
+static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
+		int *index)
+{
+	struct tty_driver *driver = NULL;
+
+	switch (device) {
+#ifdef CONFIG_VT
+	case MKDEV(TTY_MAJOR, 0): {
+		extern struct tty_driver *console_driver;
+
+		driver = tty_driver_kref_get(console_driver);
+		*index = fg_console;
+		break;
+	}
+#endif
+	case MKDEV(TTYAUX_MAJOR, 1): {
+		struct tty_driver *console_driver = console_device(index);
+
+		if (console_driver) {
+			driver = tty_driver_kref_get(console_driver);
+			if (driver && filp) {
+				/* Don't let /dev/console block */
+				filp->f_flags |= O_NONBLOCK;
+				break;
+			}
+		}
+		if (driver)
+			tty_driver_kref_put(driver);
+		return ERR_PTR(-ENODEV);
+	}
+	default:
+		driver = get_tty_driver(device, index);
+		if (!driver)
+			return ERR_PTR(-ENODEV);
+		break;
+	}
+	return driver;
+}
+
+static struct tty_struct *tty_kopen(dev_t device, int shared)
+{
+	struct tty_struct *tty;
+	struct tty_driver *driver;
+	int index = -1;
+
+	mutex_lock(&tty_mutex);
+	driver = tty_lookup_driver(device, NULL, &index);
+	if (IS_ERR(driver)) {
+		mutex_unlock(&tty_mutex);
+		return ERR_CAST(driver);
+	}
+
+	/* check whether we're reopening an existing tty */
+	tty = tty_driver_lookup_tty(driver, NULL, index);
+	if (IS_ERR(tty) || shared)
+		goto out;
+
+	if (tty) {
+		/* drop kref from tty_driver_lookup_tty() */
+		tty_kref_put(tty);
+		tty = ERR_PTR(-EBUSY);
+	} else { /* tty_init_dev returns tty with the tty_lock held */
+		tty = tty_init_dev(driver, index);
+		if (IS_ERR(tty))
+			goto out;
+		tty_port_set_kopened(tty->port, 1);
+	}
+out:
+	mutex_unlock(&tty_mutex);
+	tty_driver_kref_put(driver);
+	return tty;
+}
+
+/**
+ * tty_kopen_exclusive	-	open a tty device for kernel
+ * @device: dev_t of device to open
+ *
+ * Opens tty exclusively for kernel. Performs the driver lookup, makes sure
+ * it's not already opened and performs the first-time tty initialization.
+ *
+ * Claims the global %tty_mutex to serialize:
+ *  * concurrent first-time tty initialization
+ *  * concurrent tty driver removal w/ lookup
+ *  * concurrent tty removal from driver table
+ *
+ * Return: the locked initialized &tty_struct
+ */
+struct tty_struct *tty_kopen_exclusive(dev_t device)
+{
+	return tty_kopen(device, 0);
+}
+EXPORT_SYMBOL_GPL(tty_kopen_exclusive);
+
+/**
+ * tty_kopen_shared	-	open a tty device for shared in-kernel use
+ * @device: dev_t of device to open
+ *
+ * Opens an already existing tty for in-kernel use. Compared to
+ * tty_kopen_exclusive() above it doesn't ensure to be the only user.
+ *
+ * Locking: identical to tty_kopen() above.
+ */
+struct tty_struct *tty_kopen_shared(dev_t device)
+{
+	return tty_kopen(device, 1);
+}
+EXPORT_SYMBOL_GPL(tty_kopen_shared);
+
+/**
+ * tty_open_by_driver	-	open a tty device
+ * @device: dev_t of device to open
+ * @filp: file pointer to tty
+ *
+ * Performs the driver lookup, checks for a reopen, or otherwise performs the
+ * first-time tty initialization.
+ *
+ *
+ * Claims the global tty_mutex to serialize:
+ *  * concurrent first-time tty initialization
+ *  * concurrent tty driver removal w/ lookup
+ *  * concurrent tty removal from driver table
+ *
+ * Return: the locked initialized or re-opened &tty_struct
+ */
+static struct tty_struct *tty_open_by_driver(dev_t device,
+					     struct file *filp)
+{
+	struct tty_struct *tty;
+	struct tty_driver *driver = NULL;
+	int index = -1;
+	int retval;
+
+	mutex_lock(&tty_mutex);
+	driver = tty_lookup_driver(device, filp, &index);
+	if (IS_ERR(driver)) {
+		mutex_unlock(&tty_mutex);
+		return ERR_CAST(driver);
+	}
+
+	/* check whether we're reopening an existing tty */
+	tty = tty_driver_lookup_tty(driver, filp, index);
+	if (IS_ERR(tty)) {
+		mutex_unlock(&tty_mutex);
+		goto out;
+	}
+
+	if (tty) {
+		if (tty_port_kopened(tty->port)) {
+			tty_kref_put(tty);
+			mutex_unlock(&tty_mutex);
+			tty = ERR_PTR(-EBUSY);
+			goto out;
+		}
+		mutex_unlock(&tty_mutex);
+		retval = tty_lock_interruptible(tty);
+		tty_kref_put(tty);  /* drop kref from tty_driver_lookup_tty() */
+		if (retval) {
+			if (retval == -EINTR)
+				retval = -ERESTARTSYS;
+			tty = ERR_PTR(retval);
+			goto out;
+		}
+		retval = tty_reopen(tty);
+		if (retval < 0) {
+			tty_unlock(tty);
+			tty = ERR_PTR(retval);
+		}
+	} else { /* Returns with the tty_lock held for now */
+		tty = tty_init_dev(driver, index);
+		mutex_unlock(&tty_mutex);
+	}
+out:
+	tty_driver_kref_put(driver);
+	return tty;
+}
+
+/**
+ * tty_open	-	open a tty device
+ * @inode: inode of device file
+ * @filp: file pointer to tty
+ *
+ * tty_open() and tty_release() keep up the tty count that contains the number
+ * of opens done on a tty. We cannot use the inode-count, as different inodes
+ * might point to the same tty.
+ *
+ * Open-counting is needed for pty masters, as well as for keeping track of
+ * serial lines: DTR is dropped when the last close happens.
+ * (This is not done solely through tty->count, now.  - Ted 1/27/92)
+ *
+ * The termios state of a pty is reset on the first open so that settings don't
+ * persist across reuse.
+ *
+ * Locking:
+ *  * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev().
+ *  * @tty->count should protect the rest.
+ *  * ->siglock protects ->signal/->sighand
+ *
+ * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex
+ */
+static int tty_open(struct inode *inode, struct file *filp)
+{
+	struct tty_struct *tty;
+	int noctty, retval;
+	dev_t device = inode->i_rdev;
+	unsigned saved_flags = filp->f_flags;
+
+	nonseekable_open(inode, filp);
+
+retry_open:
+	retval = tty_alloc_file(filp);
+	if (retval)
+		return -ENOMEM;
+
+	tty = tty_open_current_tty(device, filp);
+	if (!tty)
+		tty = tty_open_by_driver(device, filp);
+
+	if (IS_ERR(tty)) {
+		tty_free_file(filp);
+		retval = PTR_ERR(tty);
+		if (retval != -EAGAIN || signal_pending(current))
+			return retval;
+		schedule();
+		goto retry_open;
+	}
+
+	tty_add_file(tty, filp);
+
+	check_tty_count(tty, __func__);
+	tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
+
+	if (tty->ops->open)
+		retval = tty->ops->open(tty, filp);
+	else
+		retval = -ENODEV;
+	filp->f_flags = saved_flags;
+
+	if (retval) {
+		tty_debug_hangup(tty, "open error %d, releasing\n", retval);
+
+		tty_unlock(tty); /* need to call tty_release without BTM */
+		tty_release(inode, filp);
+		if (retval != -ERESTARTSYS)
+			return retval;
+
+		if (signal_pending(current))
+			return retval;
+
+		schedule();
+		/*
+		 * Need to reset f_op in case a hangup happened.
+		 */
+		if (tty_hung_up_p(filp))
+			filp->f_op = &tty_fops;
+		goto retry_open;
+	}
+	clear_bit(TTY_HUPPED, &tty->flags);
+
+	noctty = (filp->f_flags & O_NOCTTY) ||
+		 (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) ||
+		 device == MKDEV(TTYAUX_MAJOR, 1) ||
+		 (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+		  tty->driver->subtype == PTY_TYPE_MASTER);
+	if (!noctty)
+		tty_open_proc_set_tty(filp, tty);
+	tty_unlock(tty);
+	return 0;
+}
+
+
+/**
+ * tty_poll	-	check tty status
+ * @filp: file being polled
+ * @wait: poll wait structures to update
+ *
+ * Call the line discipline polling method to obtain the poll status of the
+ * device.
+ *
+ * Locking: locks called line discipline but ldisc poll method may be
+ * re-entered freely by other callers.
+ */
+static __poll_t tty_poll(struct file *filp, poll_table *wait)
+{
+	struct tty_struct *tty = file_tty(filp);
+	struct tty_ldisc *ld;
+	__poll_t ret = 0;
+
+	if (tty_paranoia_check(tty, file_inode(filp), "tty_poll"))
+		return 0;
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return hung_up_tty_poll(filp, wait);
+	if (ld->ops->poll)
+		ret = ld->ops->poll(tty, filp, wait);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+static int __tty_fasync(int fd, struct file *filp, int on)
+{
+	struct tty_struct *tty = file_tty(filp);
+	unsigned long flags;
+	int retval = 0;
+
+	if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync"))
+		goto out;
+
+	retval = fasync_helper(fd, filp, on, &tty->fasync);
+	if (retval <= 0)
+		goto out;
+
+	if (on) {
+		enum pid_type type;
+		struct pid *pid;
+
+		spin_lock_irqsave(&tty->ctrl.lock, flags);
+		if (tty->ctrl.pgrp) {
+			pid = tty->ctrl.pgrp;
+			type = PIDTYPE_PGID;
+		} else {
+			pid = task_pid(current);
+			type = PIDTYPE_TGID;
+		}
+		get_pid(pid);
+		spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+		__f_setown(filp, pid, type, 0);
+		put_pid(pid);
+		retval = 0;
+	}
+out:
+	return retval;
+}
+
+static int tty_fasync(int fd, struct file *filp, int on)
+{
+	struct tty_struct *tty = file_tty(filp);
+	int retval = -ENOTTY;
+
+	tty_lock(tty);
+	if (!tty_hung_up_p(filp))
+		retval = __tty_fasync(fd, filp, on);
+	tty_unlock(tty);
+
+	return retval;
+}
+
+static bool tty_legacy_tiocsti __read_mostly = IS_ENABLED(CONFIG_LEGACY_TIOCSTI);
+/**
+ * tiocsti		-	fake input character
+ * @tty: tty to fake input into
+ * @p: pointer to character
+ *
+ * Fake input to a tty device. Does the necessary locking and input management.
+ *
+ * FIXME: does not honour flow control ??
+ *
+ * Locking:
+ *  * Called functions take tty_ldiscs_lock
+ *  * current->signal->tty check is safe without locks
+ */
+static int tiocsti(struct tty_struct *tty, char __user *p)
+{
+	char ch, mbz = 0;
+	struct tty_ldisc *ld;
+
+	if (!tty_legacy_tiocsti && !capable(CAP_SYS_ADMIN))
+		return -EIO;
+
+	if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (get_user(ch, p))
+		return -EFAULT;
+	tty_audit_tiocsti(tty, ch);
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return -EIO;
+	tty_buffer_lock_exclusive(tty->port);
+	if (ld->ops->receive_buf)
+		ld->ops->receive_buf(tty, &ch, &mbz, 1);
+	tty_buffer_unlock_exclusive(tty->port);
+	tty_ldisc_deref(ld);
+	return 0;
+}
+
+/**
+ * tiocgwinsz		-	implement window query ioctl
+ * @tty: tty
+ * @arg: user buffer for result
+ *
+ * Copies the kernel idea of the window size into the user buffer.
+ *
+ * Locking: @tty->winsize_mutex is taken to ensure the winsize data is
+ * consistent.
+ */
+static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
+{
+	int err;
+
+	mutex_lock(&tty->winsize_mutex);
+	err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
+	mutex_unlock(&tty->winsize_mutex);
+
+	return err ? -EFAULT : 0;
+}
+
+/**
+ * tty_do_resize	-	resize event
+ * @tty: tty being resized
+ * @ws: new dimensions
+ *
+ * Update the termios variables and send the necessary signals to peform a
+ * terminal resize correctly.
+ */
+int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
+{
+	struct pid *pgrp;
+
+	/* Lock the tty */
+	mutex_lock(&tty->winsize_mutex);
+	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+		goto done;
+
+	/* Signal the foreground process group */
+	pgrp = tty_get_pgrp(tty);
+	if (pgrp)
+		kill_pgrp(pgrp, SIGWINCH, 1);
+	put_pid(pgrp);
+
+	tty->winsize = *ws;
+done:
+	mutex_unlock(&tty->winsize_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(tty_do_resize);
+
+/**
+ * tiocswinsz		-	implement window size set ioctl
+ * @tty: tty side of tty
+ * @arg: user buffer for result
+ *
+ * Copies the user idea of the window size to the kernel. Traditionally this is
+ * just advisory information but for the Linux console it actually has driver
+ * level meaning and triggers a VC resize.
+ *
+ * Locking:
+ *	Driver dependent. The default do_resize method takes the tty termios
+ *	mutex and ctrl.lock. The console takes its own lock then calls into the
+ *	default method.
+ */
+static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
+{
+	struct winsize tmp_ws;
+
+	if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
+		return -EFAULT;
+
+	if (tty->ops->resize)
+		return tty->ops->resize(tty, &tmp_ws);
+	else
+		return tty_do_resize(tty, &tmp_ws);
+}
+
+/**
+ * tioccons	-	allow admin to move logical console
+ * @file: the file to become console
+ *
+ * Allow the administrator to move the redirected console device.
+ *
+ * Locking: uses redirect_lock to guard the redirect information
+ */
+static int tioccons(struct file *file)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (file->f_op->write_iter == redirected_tty_write) {
+		struct file *f;
+
+		spin_lock(&redirect_lock);
+		f = redirect;
+		redirect = NULL;
+		spin_unlock(&redirect_lock);
+		if (f)
+			fput(f);
+		return 0;
+	}
+	if (file->f_op->write_iter != tty_write)
+		return -ENOTTY;
+	if (!(file->f_mode & FMODE_WRITE))
+		return -EBADF;
+	if (!(file->f_mode & FMODE_CAN_WRITE))
+		return -EINVAL;
+	spin_lock(&redirect_lock);
+	if (redirect) {
+		spin_unlock(&redirect_lock);
+		return -EBUSY;
+	}
+	redirect = get_file(file);
+	spin_unlock(&redirect_lock);
+	return 0;
+}
+
+/**
+ * tiocsetd	-	set line discipline
+ * @tty: tty device
+ * @p: pointer to user data
+ *
+ * Set the line discipline according to user request.
+ *
+ * Locking: see tty_set_ldisc(), this function is just a helper
+ */
+static int tiocsetd(struct tty_struct *tty, int __user *p)
+{
+	int disc;
+	int ret;
+
+	if (get_user(disc, p))
+		return -EFAULT;
+
+	ret = tty_set_ldisc(tty, disc);
+
+	return ret;
+}
+
+/**
+ * tiocgetd	-	get line discipline
+ * @tty: tty device
+ * @p: pointer to user data
+ *
+ * Retrieves the line discipline id directly from the ldisc.
+ *
+ * Locking: waits for ldisc reference (in case the line discipline is changing
+ * or the @tty is being hungup)
+ */
+static int tiocgetd(struct tty_struct *tty, int __user *p)
+{
+	struct tty_ldisc *ld;
+	int ret;
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return -EIO;
+	ret = put_user(ld->ops->num, p);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+/**
+ * send_break	-	performed time break
+ * @tty: device to break on
+ * @duration: timeout in mS
+ *
+ * Perform a timed break on hardware that lacks its own driver level timed
+ * break functionality.
+ *
+ * Locking:
+ *	@tty->atomic_write_lock serializes
+ */
+static int send_break(struct tty_struct *tty, unsigned int duration)
+{
+	int retval;
+
+	if (tty->ops->break_ctl == NULL)
+		return 0;
+
+	if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
+		return tty->ops->break_ctl(tty, duration);
+
+	/* Do the work ourselves */
+	if (tty_write_lock(tty, false) < 0)
+		return -EINTR;
+
+	retval = tty->ops->break_ctl(tty, -1);
+	if (!retval) {
+		msleep_interruptible(duration);
+		retval = tty->ops->break_ctl(tty, 0);
+	} else if (retval == -EOPNOTSUPP) {
+		/* some drivers can tell only dynamically */
+		retval = 0;
+	}
+	tty_write_unlock(tty);
+
+	if (signal_pending(current))
+		retval = -EINTR;
+
+	return retval;
+}
+
+/**
+ * tty_tiocmget		-	get modem status
+ * @tty: tty device
+ * @p: pointer to result
+ *
+ * Obtain the modem status bits from the tty driver if the feature is
+ * supported. Return -%ENOTTY if it is not available.
+ *
+ * Locking: none (up to the driver)
+ */
+static int tty_tiocmget(struct tty_struct *tty, int __user *p)
+{
+	int retval = -ENOTTY;
+
+	if (tty->ops->tiocmget) {
+		retval = tty->ops->tiocmget(tty);
+
+		if (retval >= 0)
+			retval = put_user(retval, p);
+	}
+	return retval;
+}
+
+/**
+ * tty_tiocmset		-	set modem status
+ * @tty: tty device
+ * @cmd: command - clear bits, set bits or set all
+ * @p: pointer to desired bits
+ *
+ * Set the modem status bits from the tty driver if the feature
+ * is supported. Return -%ENOTTY if it is not available.
+ *
+ * Locking: none (up to the driver)
+ */
+static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd,
+	     unsigned __user *p)
+{
+	int retval;
+	unsigned int set, clear, val;
+
+	if (tty->ops->tiocmset == NULL)
+		return -ENOTTY;
+
+	retval = get_user(val, p);
+	if (retval)
+		return retval;
+	set = clear = 0;
+	switch (cmd) {
+	case TIOCMBIS:
+		set = val;
+		break;
+	case TIOCMBIC:
+		clear = val;
+		break;
+	case TIOCMSET:
+		set = val;
+		clear = ~val;
+		break;
+	}
+	set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+	clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+	return tty->ops->tiocmset(tty, set, clear);
+}
+
+/**
+ * tty_get_icount	-	get tty statistics
+ * @tty: tty device
+ * @icount: output parameter
+ *
+ * Gets a copy of the @tty's icount statistics.
+ *
+ * Locking: none (up to the driver)
+ */
+int tty_get_icount(struct tty_struct *tty,
+		   struct serial_icounter_struct *icount)
+{
+	memset(icount, 0, sizeof(*icount));
+
+	if (tty->ops->get_icount)
+		return tty->ops->get_icount(tty, icount);
+	else
+		return -ENOTTY;
+}
+EXPORT_SYMBOL_GPL(tty_get_icount);
+
+static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
+{
+	struct serial_icounter_struct icount;
+	int retval;
+
+	retval = tty_get_icount(tty, &icount);
+	if (retval != 0)
+		return retval;
+
+	if (copy_to_user(arg, &icount, sizeof(icount)))
+		return -EFAULT;
+	return 0;
+}
+
+static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss)
+{
+	char comm[TASK_COMM_LEN];
+	int flags;
+
+	flags = ss->flags & ASYNC_DEPRECATED;
+
+	if (flags)
+		pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
+				__func__, get_task_comm(comm, current), flags);
+
+	if (!tty->ops->set_serial)
+		return -ENOTTY;
+
+	return tty->ops->set_serial(tty, ss);
+}
+
+static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss)
+{
+	struct serial_struct v;
+
+	if (copy_from_user(&v, ss, sizeof(*ss)))
+		return -EFAULT;
+
+	return tty_set_serial(tty, &v);
+}
+
+static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss)
+{
+	struct serial_struct v;
+	int err;
+
+	memset(&v, 0, sizeof(v));
+	if (!tty->ops->get_serial)
+		return -ENOTTY;
+	err = tty->ops->get_serial(tty, &v);
+	if (!err && copy_to_user(ss, &v, sizeof(v)))
+		err = -EFAULT;
+	return err;
+}
+
+/*
+ * if pty, return the slave side (real_tty)
+ * otherwise, return self
+ */
+static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+{
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		tty = tty->link;
+	return tty;
+}
+
+/*
+ * Split this up, as gcc can choke on it otherwise..
+ */
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct tty_struct *tty = file_tty(file);
+	struct tty_struct *real_tty;
+	void __user *p = (void __user *)arg;
+	int retval;
+	struct tty_ldisc *ld;
+
+	if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
+		return -EINVAL;
+
+	real_tty = tty_pair_get_tty(tty);
+
+	/*
+	 * Factor out some common prep work
+	 */
+	switch (cmd) {
+	case TIOCSETD:
+	case TIOCSBRK:
+	case TIOCCBRK:
+	case TCSBRK:
+	case TCSBRKP:
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+		if (cmd != TIOCCBRK) {
+			tty_wait_until_sent(tty, 0);
+			if (signal_pending(current))
+				return -EINTR;
+		}
+		break;
+	}
+
+	/*
+	 *	Now do the stuff.
+	 */
+	switch (cmd) {
+	case TIOCSTI:
+		return tiocsti(tty, p);
+	case TIOCGWINSZ:
+		return tiocgwinsz(real_tty, p);
+	case TIOCSWINSZ:
+		return tiocswinsz(real_tty, p);
+	case TIOCCONS:
+		return real_tty != tty ? -EINVAL : tioccons(file);
+	case TIOCEXCL:
+		set_bit(TTY_EXCLUSIVE, &tty->flags);
+		return 0;
+	case TIOCNXCL:
+		clear_bit(TTY_EXCLUSIVE, &tty->flags);
+		return 0;
+	case TIOCGEXCL:
+	{
+		int excl = test_bit(TTY_EXCLUSIVE, &tty->flags);
+
+		return put_user(excl, (int __user *)p);
+	}
+	case TIOCGETD:
+		return tiocgetd(tty, p);
+	case TIOCSETD:
+		return tiocsetd(tty, p);
+	case TIOCVHANGUP:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		tty_vhangup(tty);
+		return 0;
+	case TIOCGDEV:
+	{
+		unsigned int ret = new_encode_dev(tty_devnum(real_tty));
+
+		return put_user(ret, (unsigned int __user *)p);
+	}
+	/*
+	 * Break handling
+	 */
+	case TIOCSBRK:	/* Turn break on, unconditionally */
+		if (tty->ops->break_ctl)
+			return tty->ops->break_ctl(tty, -1);
+		return 0;
+	case TIOCCBRK:	/* Turn break off, unconditionally */
+		if (tty->ops->break_ctl)
+			return tty->ops->break_ctl(tty, 0);
+		return 0;
+	case TCSBRK:   /* SVID version: non-zero arg --> no break */
+		/* non-zero arg means wait for all output data
+		 * to be sent (performed above) but don't send break.
+		 * This is used by the tcdrain() termios function.
+		 */
+		if (!arg)
+			return send_break(tty, 250);
+		return 0;
+	case TCSBRKP:	/* support for POSIX tcsendbreak() */
+		return send_break(tty, arg ? arg*100 : 250);
+
+	case TIOCMGET:
+		return tty_tiocmget(tty, p);
+	case TIOCMSET:
+	case TIOCMBIC:
+	case TIOCMBIS:
+		return tty_tiocmset(tty, cmd, p);
+	case TIOCGICOUNT:
+		return tty_tiocgicount(tty, p);
+	case TCFLSH:
+		switch (arg) {
+		case TCIFLUSH:
+		case TCIOFLUSH:
+		/* flush tty buffer and allow ldisc to process ioctl */
+			tty_buffer_flush(tty, NULL);
+			break;
+		}
+		break;
+	case TIOCSSERIAL:
+		return tty_tiocsserial(tty, p);
+	case TIOCGSERIAL:
+		return tty_tiocgserial(tty, p);
+	case TIOCGPTPEER:
+		/* Special because the struct file is needed */
+		return ptm_open_peer(file, tty, (int)arg);
+	default:
+		retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg);
+		if (retval != -ENOIOCTLCMD)
+			return retval;
+	}
+	if (tty->ops->ioctl) {
+		retval = tty->ops->ioctl(tty, cmd, arg);
+		if (retval != -ENOIOCTLCMD)
+			return retval;
+	}
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return hung_up_tty_ioctl(file, cmd, arg);
+	retval = -EINVAL;
+	if (ld->ops->ioctl) {
+		retval = ld->ops->ioctl(tty, cmd, arg);
+		if (retval == -ENOIOCTLCMD)
+			retval = -ENOTTY;
+	}
+	tty_ldisc_deref(ld);
+	return retval;
+}
+
+#ifdef CONFIG_COMPAT
+
+struct serial_struct32 {
+	compat_int_t    type;
+	compat_int_t    line;
+	compat_uint_t   port;
+	compat_int_t    irq;
+	compat_int_t    flags;
+	compat_int_t    xmit_fifo_size;
+	compat_int_t    custom_divisor;
+	compat_int_t    baud_base;
+	unsigned short  close_delay;
+	char    io_type;
+	char    reserved_char;
+	compat_int_t    hub6;
+	unsigned short  closing_wait; /* time to wait before closing */
+	unsigned short  closing_wait2; /* no longer used... */
+	compat_uint_t   iomem_base;
+	unsigned short  iomem_reg_shift;
+	unsigned int    port_high;
+	/* compat_ulong_t  iomap_base FIXME */
+	compat_int_t    reserved;
+};
+
+static int compat_tty_tiocsserial(struct tty_struct *tty,
+		struct serial_struct32 __user *ss)
+{
+	struct serial_struct32 v32;
+	struct serial_struct v;
+
+	if (copy_from_user(&v32, ss, sizeof(*ss)))
+		return -EFAULT;
+
+	memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base));
+	v.iomem_base = compat_ptr(v32.iomem_base);
+	v.iomem_reg_shift = v32.iomem_reg_shift;
+	v.port_high = v32.port_high;
+	v.iomap_base = 0;
+
+	return tty_set_serial(tty, &v);
+}
+
+static int compat_tty_tiocgserial(struct tty_struct *tty,
+			struct serial_struct32 __user *ss)
+{
+	struct serial_struct32 v32;
+	struct serial_struct v;
+	int err;
+
+	memset(&v, 0, sizeof(v));
+	memset(&v32, 0, sizeof(v32));
+
+	if (!tty->ops->get_serial)
+		return -ENOTTY;
+	err = tty->ops->get_serial(tty, &v);
+	if (!err) {
+		memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base));
+		v32.iomem_base = (unsigned long)v.iomem_base >> 32 ?
+			0xfffffff : ptr_to_compat(v.iomem_base);
+		v32.iomem_reg_shift = v.iomem_reg_shift;
+		v32.port_high = v.port_high;
+		if (copy_to_user(ss, &v32, sizeof(v32)))
+			err = -EFAULT;
+	}
+	return err;
+}
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	struct tty_struct *tty = file_tty(file);
+	struct tty_ldisc *ld;
+	int retval = -ENOIOCTLCMD;
+
+	switch (cmd) {
+	case TIOCOUTQ:
+	case TIOCSTI:
+	case TIOCGWINSZ:
+	case TIOCSWINSZ:
+	case TIOCGEXCL:
+	case TIOCGETD:
+	case TIOCSETD:
+	case TIOCGDEV:
+	case TIOCMGET:
+	case TIOCMSET:
+	case TIOCMBIC:
+	case TIOCMBIS:
+	case TIOCGICOUNT:
+	case TIOCGPGRP:
+	case TIOCSPGRP:
+	case TIOCGSID:
+	case TIOCSERGETLSR:
+	case TIOCGRS485:
+	case TIOCSRS485:
+#ifdef TIOCGETP
+	case TIOCGETP:
+	case TIOCSETP:
+	case TIOCSETN:
+#endif
+#ifdef TIOCGETC
+	case TIOCGETC:
+	case TIOCSETC:
+#endif
+#ifdef TIOCGLTC
+	case TIOCGLTC:
+	case TIOCSLTC:
+#endif
+	case TCSETSF:
+	case TCSETSW:
+	case TCSETS:
+	case TCGETS:
+#ifdef TCGETS2
+	case TCGETS2:
+	case TCSETSF2:
+	case TCSETSW2:
+	case TCSETS2:
+#endif
+	case TCGETA:
+	case TCSETAF:
+	case TCSETAW:
+	case TCSETA:
+	case TIOCGLCKTRMIOS:
+	case TIOCSLCKTRMIOS:
+#ifdef TCGETX
+	case TCGETX:
+	case TCSETX:
+	case TCSETXW:
+	case TCSETXF:
+#endif
+	case TIOCGSOFTCAR:
+	case TIOCSSOFTCAR:
+
+	case PPPIOCGCHAN:
+	case PPPIOCGUNIT:
+		return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+	case TIOCCONS:
+	case TIOCEXCL:
+	case TIOCNXCL:
+	case TIOCVHANGUP:
+	case TIOCSBRK:
+	case TIOCCBRK:
+	case TCSBRK:
+	case TCSBRKP:
+	case TCFLSH:
+	case TIOCGPTPEER:
+	case TIOCNOTTY:
+	case TIOCSCTTY:
+	case TCXONC:
+	case TIOCMIWAIT:
+	case TIOCSERCONFIG:
+		return tty_ioctl(file, cmd, arg);
+	}
+
+	if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
+		return -EINVAL;
+
+	switch (cmd) {
+	case TIOCSSERIAL:
+		return compat_tty_tiocsserial(tty, compat_ptr(arg));
+	case TIOCGSERIAL:
+		return compat_tty_tiocgserial(tty, compat_ptr(arg));
+	}
+	if (tty->ops->compat_ioctl) {
+		retval = tty->ops->compat_ioctl(tty, cmd, arg);
+		if (retval != -ENOIOCTLCMD)
+			return retval;
+	}
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return hung_up_tty_compat_ioctl(file, cmd, arg);
+	if (ld->ops->compat_ioctl)
+		retval = ld->ops->compat_ioctl(tty, cmd, arg);
+	if (retval == -ENOIOCTLCMD && ld->ops->ioctl)
+		retval = ld->ops->ioctl(tty, (unsigned long)compat_ptr(cmd),
+				arg);
+	tty_ldisc_deref(ld);
+
+	return retval;
+}
+#endif
+
+static int this_tty(const void *t, struct file *file, unsigned fd)
+{
+	if (likely(file->f_op->read_iter != tty_read))
+		return 0;
+	return file_tty(file) != t ? 0 : fd + 1;
+}
+
+/*
+ * This implements the "Secure Attention Key" ---  the idea is to
+ * prevent trojan horses by killing all processes associated with this
+ * tty when the user hits the "Secure Attention Key".  Required for
+ * super-paranoid applications --- see the Orange Book for more details.
+ *
+ * This code could be nicer; ideally it should send a HUP, wait a few
+ * seconds, then send a INT, and then a KILL signal.  But you then
+ * have to coordinate with the init process, since all processes associated
+ * with the current tty must be dead before the new getty is allowed
+ * to spawn.
+ *
+ * Now, if it would be correct ;-/ The current code has a nasty hole -
+ * it doesn't catch files in flight. We may send the descriptor to ourselves
+ * via AF_UNIX socket, close it and later fetch from socket. FIXME.
+ *
+ * Nasty bug: do_SAK is being called in interrupt context.  This can
+ * deadlock.  We punt it up to process context.  AKPM - 16Mar2001
+ */
+void __do_SAK(struct tty_struct *tty)
+{
+	struct task_struct *g, *p;
+	struct pid *session;
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->ctrl.lock, flags);
+	session = get_pid(tty->ctrl.session);
+	spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+
+	tty_ldisc_flush(tty);
+
+	tty_driver_flush_buffer(tty);
+
+	read_lock(&tasklist_lock);
+	/* Kill the entire session */
+	do_each_pid_task(session, PIDTYPE_SID, p) {
+		tty_notice(tty, "SAK: killed process %d (%s): by session\n",
+			   task_pid_nr(p), p->comm);
+		group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID);
+	} while_each_pid_task(session, PIDTYPE_SID, p);
+
+	/* Now kill any processes that happen to have the tty open */
+	for_each_process_thread(g, p) {
+		if (p->signal->tty == tty) {
+			tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n",
+				   task_pid_nr(p), p->comm);
+			group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p,
+					PIDTYPE_SID);
+			continue;
+		}
+		task_lock(p);
+		i = iterate_fd(p->files, 0, this_tty, tty);
+		if (i != 0) {
+			tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n",
+				   task_pid_nr(p), p->comm, i - 1);
+			group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p,
+					PIDTYPE_SID);
+		}
+		task_unlock(p);
+	}
+	read_unlock(&tasklist_lock);
+	put_pid(session);
+}
+
+static void do_SAK_work(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, SAK_work);
+	__do_SAK(tty);
+}
+
+/*
+ * The tq handling here is a little racy - tty->SAK_work may already be queued.
+ * Fortunately we don't need to worry, because if ->SAK_work is already queued,
+ * the values which we write to it will be identical to the values which it
+ * already has. --akpm
+ */
+void do_SAK(struct tty_struct *tty)
+{
+	if (!tty)
+		return;
+	schedule_work(&tty->SAK_work);
+}
+EXPORT_SYMBOL(do_SAK);
+
+/* Must put_device() after it's unused! */
+static struct device *tty_get_device(struct tty_struct *tty)
+{
+	dev_t devt = tty_devnum(tty);
+
+	return class_find_device_by_devt(&tty_class, devt);
+}
+
+
+/**
+ * alloc_tty_struct - allocate a new tty
+ * @driver: driver which will handle the returned tty
+ * @idx: minor of the tty
+ *
+ * This subroutine allocates and initializes a tty structure.
+ *
+ * Locking: none - @tty in question is not exposed at this point
+ */
+struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
+{
+	struct tty_struct *tty;
+
+	tty = kzalloc(sizeof(*tty), GFP_KERNEL_ACCOUNT);
+	if (!tty)
+		return NULL;
+
+	kref_init(&tty->kref);
+	if (tty_ldisc_init(tty)) {
+		kfree(tty);
+		return NULL;
+	}
+	tty->ctrl.session = NULL;
+	tty->ctrl.pgrp = NULL;
+	mutex_init(&tty->legacy_mutex);
+	mutex_init(&tty->throttle_mutex);
+	init_rwsem(&tty->termios_rwsem);
+	mutex_init(&tty->winsize_mutex);
+	init_ldsem(&tty->ldisc_sem);
+	init_waitqueue_head(&tty->write_wait);
+	init_waitqueue_head(&tty->read_wait);
+	INIT_WORK(&tty->hangup_work, do_tty_hangup);
+	mutex_init(&tty->atomic_write_lock);
+	spin_lock_init(&tty->ctrl.lock);
+	spin_lock_init(&tty->flow.lock);
+	spin_lock_init(&tty->files_lock);
+	INIT_LIST_HEAD(&tty->tty_files);
+	INIT_WORK(&tty->SAK_work, do_SAK_work);
+
+	tty->driver = driver;
+	tty->ops = driver->ops;
+	tty->index = idx;
+	tty_line_name(driver, idx, tty->name);
+	tty->dev = tty_get_device(tty);
+
+	return tty;
+}
+
+/**
+ * tty_put_char	- write one character to a tty
+ * @tty: tty
+ * @ch: character to write
+ *
+ * Write one byte to the @tty using the provided @tty->ops->put_char() method
+ * if present.
+ *
+ * Note: the specific put_char operation in the driver layer may go
+ * away soon. Don't call it directly, use this method
+ *
+ * Return: the number of characters successfully output.
+ */
+int tty_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	if (tty->ops->put_char)
+		return tty->ops->put_char(tty, ch);
+	return tty->ops->write(tty, &ch, 1);
+}
+EXPORT_SYMBOL_GPL(tty_put_char);
+
+static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
+		unsigned int index, unsigned int count)
+{
+	int err;
+
+	/* init here, since reused cdevs cause crashes */
+	driver->cdevs[index] = cdev_alloc();
+	if (!driver->cdevs[index])
+		return -ENOMEM;
+	driver->cdevs[index]->ops = &tty_fops;
+	driver->cdevs[index]->owner = driver->owner;
+	err = cdev_add(driver->cdevs[index], dev, count);
+	if (err)
+		kobject_put(&driver->cdevs[index]->kobj);
+	return err;
+}
+
+/**
+ * tty_register_device - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ *	This field is optional, if there is no known struct device
+ *	for this tty device it can be set to NULL safely.
+ *
+ * This call is required to be made to register an individual tty device
+ * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set.  If
+ * that bit is not set, this function should not be called by a tty
+ * driver.
+ *
+ * Locking: ??
+ *
+ * Return: A pointer to the struct device for this tty device (or
+ * ERR_PTR(-EFOO) on error).
+ */
+struct device *tty_register_device(struct tty_driver *driver, unsigned index,
+				   struct device *device)
+{
+	return tty_register_device_attr(driver, index, device, NULL, NULL);
+}
+EXPORT_SYMBOL(tty_register_device);
+
+static void tty_device_create_release(struct device *dev)
+{
+	dev_dbg(dev, "releasing...\n");
+	kfree(dev);
+}
+
+/**
+ * tty_register_device_attr - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ *	This field is optional, if there is no known struct device
+ *	for this tty device it can be set to %NULL safely.
+ * @drvdata: Driver data to be set to device.
+ * @attr_grp: Attribute group to be set on device.
+ *
+ * This call is required to be made to register an individual tty device if the
+ * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is
+ * not set, this function should not be called by a tty driver.
+ *
+ * Locking: ??
+ *
+ * Return: A pointer to the struct device for this tty device (or
+ * ERR_PTR(-EFOO) on error).
+ */
+struct device *tty_register_device_attr(struct tty_driver *driver,
+				   unsigned index, struct device *device,
+				   void *drvdata,
+				   const struct attribute_group **attr_grp)
+{
+	char name[64];
+	dev_t devt = MKDEV(driver->major, driver->minor_start) + index;
+	struct ktermios *tp;
+	struct device *dev;
+	int retval;
+
+	if (index >= driver->num) {
+		pr_err("%s: Attempt to register invalid tty line number (%d)\n",
+		       driver->name, index);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY)
+		pty_line_name(driver, index, name);
+	else
+		tty_line_name(driver, index, name);
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	dev->devt = devt;
+	dev->class = &tty_class;
+	dev->parent = device;
+	dev->release = tty_device_create_release;
+	dev_set_name(dev, "%s", name);
+	dev->groups = attr_grp;
+	dev_set_drvdata(dev, drvdata);
+
+	dev_set_uevent_suppress(dev, 1);
+
+	retval = device_register(dev);
+	if (retval)
+		goto err_put;
+
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+		/*
+		 * Free any saved termios data so that the termios state is
+		 * reset when reusing a minor number.
+		 */
+		tp = driver->termios[index];
+		if (tp) {
+			driver->termios[index] = NULL;
+			kfree(tp);
+		}
+
+		retval = tty_cdev_add(driver, devt, index, 1);
+		if (retval)
+			goto err_del;
+	}
+
+	dev_set_uevent_suppress(dev, 0);
+	kobject_uevent(&dev->kobj, KOBJ_ADD);
+
+	return dev;
+
+err_del:
+	device_del(dev);
+err_put:
+	put_device(dev);
+
+	return ERR_PTR(retval);
+}
+EXPORT_SYMBOL_GPL(tty_register_device_attr);
+
+/**
+ * tty_unregister_device - unregister a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ *
+ * If a tty device is registered with a call to tty_register_device() then
+ * this function must be called when the tty device is gone.
+ *
+ * Locking: ??
+ */
+void tty_unregister_device(struct tty_driver *driver, unsigned index)
+{
+	device_destroy(&tty_class, MKDEV(driver->major, driver->minor_start) + index);
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+		cdev_del(driver->cdevs[index]);
+		driver->cdevs[index] = NULL;
+	}
+}
+EXPORT_SYMBOL(tty_unregister_device);
+
+/**
+ * __tty_alloc_driver -- allocate tty driver
+ * @lines: count of lines this driver can handle at most
+ * @owner: module which is responsible for this driver
+ * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags
+ *
+ * This should not be called directly, some of the provided macros should be
+ * used instead. Use IS_ERR() and friends on @retval.
+ */
+struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
+		unsigned long flags)
+{
+	struct tty_driver *driver;
+	unsigned int cdevs = 1;
+	int err;
+
+	if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1))
+		return ERR_PTR(-EINVAL);
+
+	driver = kzalloc(sizeof(*driver), GFP_KERNEL);
+	if (!driver)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&driver->kref);
+	driver->num = lines;
+	driver->owner = owner;
+	driver->flags = flags;
+
+	if (!(flags & TTY_DRIVER_DEVPTS_MEM)) {
+		driver->ttys = kcalloc(lines, sizeof(*driver->ttys),
+				GFP_KERNEL);
+		driver->termios = kcalloc(lines, sizeof(*driver->termios),
+				GFP_KERNEL);
+		if (!driver->ttys || !driver->termios) {
+			err = -ENOMEM;
+			goto err_free_all;
+		}
+	}
+
+	if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+		driver->ports = kcalloc(lines, sizeof(*driver->ports),
+				GFP_KERNEL);
+		if (!driver->ports) {
+			err = -ENOMEM;
+			goto err_free_all;
+		}
+		cdevs = lines;
+	}
+
+	driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL);
+	if (!driver->cdevs) {
+		err = -ENOMEM;
+		goto err_free_all;
+	}
+
+	return driver;
+err_free_all:
+	kfree(driver->ports);
+	kfree(driver->ttys);
+	kfree(driver->termios);
+	kfree(driver->cdevs);
+	kfree(driver);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(__tty_alloc_driver);
+
+static void destruct_tty_driver(struct kref *kref)
+{
+	struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
+	int i;
+	struct ktermios *tp;
+
+	if (driver->flags & TTY_DRIVER_INSTALLED) {
+		for (i = 0; i < driver->num; i++) {
+			tp = driver->termios[i];
+			if (tp) {
+				driver->termios[i] = NULL;
+				kfree(tp);
+			}
+			if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
+				tty_unregister_device(driver, i);
+		}
+		proc_tty_unregister_driver(driver);
+		if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)
+			cdev_del(driver->cdevs[0]);
+	}
+	kfree(driver->cdevs);
+	kfree(driver->ports);
+	kfree(driver->termios);
+	kfree(driver->ttys);
+	kfree(driver);
+}
+
+/**
+ * tty_driver_kref_put -- drop a reference to a tty driver
+ * @driver: driver of which to drop the reference
+ *
+ * The final put will destroy and free up the driver.
+ */
+void tty_driver_kref_put(struct tty_driver *driver)
+{
+	kref_put(&driver->kref, destruct_tty_driver);
+}
+EXPORT_SYMBOL(tty_driver_kref_put);
+
+/**
+ * tty_register_driver -- register a tty driver
+ * @driver: driver to register
+ *
+ * Called by a tty driver to register itself.
+ */
+int tty_register_driver(struct tty_driver *driver)
+{
+	int error;
+	int i;
+	dev_t dev;
+	struct device *d;
+
+	if (!driver->major) {
+		error = alloc_chrdev_region(&dev, driver->minor_start,
+						driver->num, driver->name);
+		if (!error) {
+			driver->major = MAJOR(dev);
+			driver->minor_start = MINOR(dev);
+		}
+	} else {
+		dev = MKDEV(driver->major, driver->minor_start);
+		error = register_chrdev_region(dev, driver->num, driver->name);
+	}
+	if (error < 0)
+		goto err;
+
+	if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) {
+		error = tty_cdev_add(driver, dev, 0, driver->num);
+		if (error)
+			goto err_unreg_char;
+	}
+
+	mutex_lock(&tty_mutex);
+	list_add(&driver->tty_drivers, &tty_drivers);
+	mutex_unlock(&tty_mutex);
+
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
+		for (i = 0; i < driver->num; i++) {
+			d = tty_register_device(driver, i, NULL);
+			if (IS_ERR(d)) {
+				error = PTR_ERR(d);
+				goto err_unreg_devs;
+			}
+		}
+	}
+	proc_tty_register_driver(driver);
+	driver->flags |= TTY_DRIVER_INSTALLED;
+	return 0;
+
+err_unreg_devs:
+	for (i--; i >= 0; i--)
+		tty_unregister_device(driver, i);
+
+	mutex_lock(&tty_mutex);
+	list_del(&driver->tty_drivers);
+	mutex_unlock(&tty_mutex);
+
+err_unreg_char:
+	unregister_chrdev_region(dev, driver->num);
+err:
+	return error;
+}
+EXPORT_SYMBOL(tty_register_driver);
+
+/**
+ * tty_unregister_driver -- unregister a tty driver
+ * @driver: driver to unregister
+ *
+ * Called by a tty driver to unregister itself.
+ */
+void tty_unregister_driver(struct tty_driver *driver)
+{
+	unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
+				driver->num);
+	mutex_lock(&tty_mutex);
+	list_del(&driver->tty_drivers);
+	mutex_unlock(&tty_mutex);
+}
+EXPORT_SYMBOL(tty_unregister_driver);
+
+dev_t tty_devnum(struct tty_struct *tty)
+{
+	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+}
+EXPORT_SYMBOL(tty_devnum);
+
+void tty_default_fops(struct file_operations *fops)
+{
+	*fops = tty_fops;
+}
+
+static char *tty_devnode(const struct device *dev, umode_t *mode)
+{
+	if (!mode)
+		return NULL;
+	if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) ||
+	    dev->devt == MKDEV(TTYAUX_MAJOR, 2))
+		*mode = 0666;
+	return NULL;
+}
+
+const struct class tty_class = {
+	.name		= "tty",
+	.devnode	= tty_devnode,
+};
+
+static int __init tty_class_init(void)
+{
+	return class_register(&tty_class);
+}
+
+postcore_initcall(tty_class_init);
+
+/* 3/2004 jmc: why do these devices exist? */
+static struct cdev tty_cdev, console_cdev;
+
+static ssize_t show_cons_active(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct console *cs[16];
+	int i = 0;
+	struct console *c;
+	ssize_t count = 0;
+
+	/*
+	 * Hold the console_list_lock to guarantee that no consoles are
+	 * unregistered until all console processing is complete.
+	 * This also allows safe traversal of the console list and
+	 * race-free reading of @flags.
+	 */
+	console_list_lock();
+
+	for_each_console(c) {
+		if (!c->device)
+			continue;
+		if (!c->write)
+			continue;
+		if ((c->flags & CON_ENABLED) == 0)
+			continue;
+		cs[i++] = c;
+		if (i >= ARRAY_SIZE(cs))
+			break;
+	}
+
+	/*
+	 * Take console_lock to serialize device() callback with
+	 * other console operations. For example, fg_console is
+	 * modified under console_lock when switching vt.
+	 */
+	console_lock();
+	while (i--) {
+		int index = cs[i]->index;
+		struct tty_driver *drv = cs[i]->device(cs[i], &index);
+
+		/* don't resolve tty0 as some programs depend on it */
+		if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR))
+			count += tty_line_name(drv, index, buf + count);
+		else
+			count += sprintf(buf + count, "%s%d",
+					 cs[i]->name, cs[i]->index);
+
+		count += sprintf(buf + count, "%c", i ? ' ':'\n');
+	}
+	console_unlock();
+
+	console_list_unlock();
+
+	return count;
+}
+static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL);
+
+static struct attribute *cons_dev_attrs[] = {
+	&dev_attr_active.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(cons_dev);
+
+static struct device *consdev;
+
+void console_sysfs_notify(void)
+{
+	if (consdev)
+		sysfs_notify(&consdev->kobj, NULL, "active");
+}
+
+static struct ctl_table tty_table[] = {
+	{
+		.procname	= "legacy_tiocsti",
+		.data		= &tty_legacy_tiocsti,
+		.maxlen		= sizeof(tty_legacy_tiocsti),
+		.mode		= 0644,
+		.proc_handler	= proc_dobool,
+	},
+	{
+		.procname	= "ldisc_autoload",
+		.data		= &tty_ldisc_autoload,
+		.maxlen		= sizeof(tty_ldisc_autoload),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{ }
+};
+
+/*
+ * Ok, now we can initialize the rest of the tty devices and can count
+ * on memory allocations, interrupts etc..
+ */
+int __init tty_init(void)
+{
+	register_sysctl_init("dev/tty", tty_table);
+	cdev_init(&tty_cdev, &tty_fops);
+	if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
+		panic("Couldn't register /dev/tty driver\n");
+	device_create(&tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
+
+	cdev_init(&console_cdev, &console_fops);
+	if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
+		panic("Couldn't register /dev/console driver\n");
+	consdev = device_create_with_groups(&tty_class, NULL,
+					    MKDEV(TTYAUX_MAJOR, 1), NULL,
+					    cons_dev_groups, "console");
+	if (IS_ERR(consdev))
+		consdev = NULL;
+
+#ifdef CONFIG_VT
+	vty_init(&console_fops);
+#endif
+	return 0;
+}
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
new file mode 100644
index 000000000..7958bf6d2
--- /dev/null
+++ b/drivers/tty/tty_ioctl.c
@@ -0,0 +1,995 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ */
+
+#include <linux/bits.h>
+#include <linux/types.h>
+#include <linux/termios.h>
+#include <linux/errno.h>
+#include <linux/sched/signal.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/tty.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
+#include <linux/compat.h>
+#include <linux/termios_internal.h>
+#include "tty.h"
+
+#include <asm/io.h>
+#include <linux/uaccess.h>
+
+#undef	DEBUG
+
+/*
+ * Internal flag options for termios setting behavior
+ */
+#define TERMIOS_FLUSH	BIT(0)
+#define TERMIOS_WAIT	BIT(1)
+#define TERMIOS_TERMIO	BIT(2)
+#define TERMIOS_OLD	BIT(3)
+
+
+/**
+ *	tty_chars_in_buffer	-	characters pending
+ *	@tty: terminal
+ *
+ *	Return the number of bytes of data in the device private
+ *	output queue. If no private method is supplied there is assumed
+ *	to be no queue on the device.
+ */
+
+unsigned int tty_chars_in_buffer(struct tty_struct *tty)
+{
+	if (tty->ops->chars_in_buffer)
+		return tty->ops->chars_in_buffer(tty);
+	return 0;
+}
+EXPORT_SYMBOL(tty_chars_in_buffer);
+
+/**
+ *	tty_write_room		-	write queue space
+ *	@tty: terminal
+ *
+ *	Return the number of bytes that can be queued to this device
+ *	at the present time. The result should be treated as a guarantee
+ *	and the driver cannot offer a value it later shrinks by more than
+ *	the number of bytes written. If no method is provided 2K is always
+ *	returned and data may be lost as there will be no flow control.
+ */
+ 
+unsigned int tty_write_room(struct tty_struct *tty)
+{
+	if (tty->ops->write_room)
+		return tty->ops->write_room(tty);
+	return 2048;
+}
+EXPORT_SYMBOL(tty_write_room);
+
+/**
+ *	tty_driver_flush_buffer	-	discard internal buffer
+ *	@tty: terminal
+ *
+ *	Discard the internal output buffer for this device. If no method
+ *	is provided then either the buffer cannot be hardware flushed or
+ *	there is no buffer driver side.
+ */
+void tty_driver_flush_buffer(struct tty_struct *tty)
+{
+	if (tty->ops->flush_buffer)
+		tty->ops->flush_buffer(tty);
+}
+EXPORT_SYMBOL(tty_driver_flush_buffer);
+
+/**
+ *	tty_unthrottle		-	flow control
+ *	@tty: terminal
+ *
+ *	Indicate that a tty may continue transmitting data down the stack.
+ *	Takes the termios rwsem to protect against parallel throttle/unthrottle
+ *	and also to ensure the driver can consistently reference its own
+ *	termios data at this point when implementing software flow control.
+ *
+ *	Drivers should however remember that the stack can issue a throttle,
+ *	then change flow control method, then unthrottle.
+ */
+
+void tty_unthrottle(struct tty_struct *tty)
+{
+	down_write(&tty->termios_rwsem);
+	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
+	    tty->ops->unthrottle)
+		tty->ops->unthrottle(tty);
+	tty->flow_change = 0;
+	up_write(&tty->termios_rwsem);
+}
+EXPORT_SYMBOL(tty_unthrottle);
+
+/**
+ *	tty_throttle_safe	-	flow control
+ *	@tty: terminal
+ *
+ *	Indicate that a tty should stop transmitting data down the stack.
+ *	tty_throttle_safe will only attempt throttle if tty->flow_change is
+ *	TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race
+ *	conditions when throttling is conditional on factors evaluated prior to
+ *	throttling.
+ *
+ *	Returns 0 if tty is throttled (or was already throttled)
+ */
+
+int tty_throttle_safe(struct tty_struct *tty)
+{
+	int ret = 0;
+
+	mutex_lock(&tty->throttle_mutex);
+	if (!tty_throttled(tty)) {
+		if (tty->flow_change != TTY_THROTTLE_SAFE)
+			ret = 1;
+		else {
+			set_bit(TTY_THROTTLED, &tty->flags);
+			if (tty->ops->throttle)
+				tty->ops->throttle(tty);
+		}
+	}
+	mutex_unlock(&tty->throttle_mutex);
+
+	return ret;
+}
+
+/**
+ *	tty_unthrottle_safe	-	flow control
+ *	@tty: terminal
+ *
+ *	Similar to tty_unthrottle() but will only attempt unthrottle
+ *	if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
+ *	unthrottle due to race conditions when unthrottling is conditional
+ *	on factors evaluated prior to unthrottling.
+ *
+ *	Returns 0 if tty is unthrottled (or was already unthrottled)
+ */
+
+int tty_unthrottle_safe(struct tty_struct *tty)
+{
+	int ret = 0;
+
+	mutex_lock(&tty->throttle_mutex);
+	if (tty_throttled(tty)) {
+		if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
+			ret = 1;
+		else {
+			clear_bit(TTY_THROTTLED, &tty->flags);
+			if (tty->ops->unthrottle)
+				tty->ops->unthrottle(tty);
+		}
+	}
+	mutex_unlock(&tty->throttle_mutex);
+
+	return ret;
+}
+
+/**
+ *	tty_wait_until_sent	-	wait for I/O to finish
+ *	@tty: tty we are waiting for
+ *	@timeout: how long we will wait
+ *
+ *	Wait for characters pending in a tty driver to hit the wire, or
+ *	for a timeout to occur (eg due to flow control)
+ *
+ *	Locking: none
+ */
+
+void tty_wait_until_sent(struct tty_struct *tty, long timeout)
+{
+	if (!timeout)
+		timeout = MAX_SCHEDULE_TIMEOUT;
+
+	timeout = wait_event_interruptible_timeout(tty->write_wait,
+			!tty_chars_in_buffer(tty), timeout);
+	if (timeout <= 0)
+		return;
+
+	if (timeout == MAX_SCHEDULE_TIMEOUT)
+		timeout = 0;
+
+	if (tty->ops->wait_until_sent)
+		tty->ops->wait_until_sent(tty, timeout);
+}
+EXPORT_SYMBOL(tty_wait_until_sent);
+
+
+/*
+ *		Termios Helper Methods
+ */
+
+static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old)
+{
+	struct ktermios *termios = &tty->termios;
+	struct ktermios *locked  = &tty->termios_locked;
+	int	i;
+
+#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
+
+	NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
+	NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
+	NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
+	NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
+	termios->c_line = locked->c_line ? old->c_line : termios->c_line;
+	for (i = 0; i < NCCS; i++)
+		termios->c_cc[i] = locked->c_cc[i] ?
+			old->c_cc[i] : termios->c_cc[i];
+	/* FIXME: What should we do for i/ospeed */
+}
+
+/**
+ *	tty_termios_copy_hw	-	copy hardware settings
+ *	@new: New termios
+ *	@old: Old termios
+ *
+ *	Propagate the hardware specific terminal setting bits from
+ *	the old termios structure to the new one. This is used in cases
+ *	where the hardware does not support reconfiguration or as a helper
+ *	in some cases where only minimal reconfiguration is supported
+ */
+
+void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
+{
+	/* The bits a dumb device handles in software. Smart devices need
+	   to always provide a set_termios method */
+	new->c_cflag &= HUPCL | CREAD | CLOCAL;
+	new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
+	new->c_ispeed = old->c_ispeed;
+	new->c_ospeed = old->c_ospeed;
+}
+EXPORT_SYMBOL(tty_termios_copy_hw);
+
+/**
+ *	tty_termios_hw_change	-	check for setting change
+ *	@a: termios
+ *	@b: termios to compare
+ *
+ *	Check if any of the bits that affect a dumb device have changed
+ *	between the two termios structures, or a speed change is needed.
+ */
+
+bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
+{
+	if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
+		return true;
+	if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(tty_termios_hw_change);
+
+/**
+ *	tty_get_char_size	-	get size of a character
+ *	@cflag: termios cflag value
+ *
+ *	Get the size (in bits) of a character depending on @cflag's %CSIZE
+ *	setting.
+ */
+unsigned char tty_get_char_size(unsigned int cflag)
+{
+	switch (cflag & CSIZE) {
+	case CS5:
+		return 5;
+	case CS6:
+		return 6;
+	case CS7:
+		return 7;
+	case CS8:
+	default:
+		return 8;
+	}
+}
+EXPORT_SYMBOL_GPL(tty_get_char_size);
+
+/**
+ *	tty_get_frame_size	-	get size of a frame
+ *	@cflag: termios cflag value
+ *
+ *	Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB,
+ *	and %PARENB setting. The result is a sum of character size, start and
+ *	stop bits -- one bit each -- second stop bit (if set), and parity bit
+ *	(if set).
+ */
+unsigned char tty_get_frame_size(unsigned int cflag)
+{
+	unsigned char bits = 2 + tty_get_char_size(cflag);
+
+	if (cflag & CSTOPB)
+		bits++;
+	if (cflag & PARENB)
+		bits++;
+	if (cflag & ADDRB)
+		bits++;
+
+	return bits;
+}
+EXPORT_SYMBOL_GPL(tty_get_frame_size);
+
+/**
+ *	tty_set_termios		-	update termios values
+ *	@tty: tty to update
+ *	@new_termios: desired new value
+ *
+ *	Perform updates to the termios values set on this terminal.
+ *	A master pty's termios should never be set.
+ *
+ *	Locking: termios_rwsem
+ */
+
+int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
+{
+	struct ktermios old_termios;
+	struct tty_ldisc *ld;
+
+	WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+		tty->driver->subtype == PTY_TYPE_MASTER);
+	/*
+	 *	Perform the actual termios internal changes under lock.
+	 */
+
+
+	/* FIXME: we need to decide on some locking/ordering semantics
+	   for the set_termios notification eventually */
+	down_write(&tty->termios_rwsem);
+	old_termios = tty->termios;
+	tty->termios = *new_termios;
+	unset_locked_termios(tty, &old_termios);
+	/* Reset any ADDRB changes, ADDRB is changed through ->rs485_config() */
+	tty->termios.c_cflag ^= (tty->termios.c_cflag ^ old_termios.c_cflag) & ADDRB;
+
+	if (tty->ops->set_termios)
+		tty->ops->set_termios(tty, &old_termios);
+	else
+		tty_termios_copy_hw(&tty->termios, &old_termios);
+
+	ld = tty_ldisc_ref(tty);
+	if (ld != NULL) {
+		if (ld->ops->set_termios)
+			ld->ops->set_termios(tty, &old_termios);
+		tty_ldisc_deref(ld);
+	}
+	up_write(&tty->termios_rwsem);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tty_set_termios);
+
+
+/*
+ * Translate a "termio" structure into a "termios". Ugh.
+ */
+__weak int user_termio_to_kernel_termios(struct ktermios *termios,
+						struct termio __user *termio)
+{
+	struct termio v;
+
+	if (copy_from_user(&v, termio, sizeof(struct termio)))
+		return -EFAULT;
+
+	termios->c_iflag = (0xffff0000 & termios->c_iflag) | v.c_iflag;
+	termios->c_oflag = (0xffff0000 & termios->c_oflag) | v.c_oflag;
+	termios->c_cflag = (0xffff0000 & termios->c_cflag) | v.c_cflag;
+	termios->c_lflag = (0xffff0000 & termios->c_lflag) | v.c_lflag;
+	termios->c_line = (0xffff0000 & termios->c_lflag) | v.c_line;
+	memcpy(termios->c_cc, v.c_cc, NCC);
+	return 0;
+}
+
+/*
+ * Translate a "termios" structure into a "termio". Ugh.
+ */
+__weak int kernel_termios_to_user_termio(struct termio __user *termio,
+						struct ktermios *termios)
+{
+	struct termio v;
+	memset(&v, 0, sizeof(struct termio));
+	v.c_iflag = termios->c_iflag;
+	v.c_oflag = termios->c_oflag;
+	v.c_cflag = termios->c_cflag;
+	v.c_lflag = termios->c_lflag;
+	v.c_line = termios->c_line;
+	memcpy(v.c_cc, termios->c_cc, NCC);
+	return copy_to_user(termio, &v, sizeof(struct termio));
+}
+
+#ifdef TCGETS2
+__weak int user_termios_to_kernel_termios(struct ktermios *k,
+						 struct termios2 __user *u)
+{
+	return copy_from_user(k, u, sizeof(struct termios2));
+}
+__weak int kernel_termios_to_user_termios(struct termios2 __user *u,
+						 struct ktermios *k)
+{
+	return copy_to_user(u, k, sizeof(struct termios2));
+}
+__weak int user_termios_to_kernel_termios_1(struct ktermios *k,
+						   struct termios __user *u)
+{
+	return copy_from_user(k, u, sizeof(struct termios));
+}
+__weak int kernel_termios_to_user_termios_1(struct termios __user *u,
+						   struct ktermios *k)
+{
+	return copy_to_user(u, k, sizeof(struct termios));
+}
+
+#else
+
+__weak int user_termios_to_kernel_termios(struct ktermios *k,
+						 struct termios __user *u)
+{
+	return copy_from_user(k, u, sizeof(struct termios));
+}
+__weak int kernel_termios_to_user_termios(struct termios __user *u,
+						 struct ktermios *k)
+{
+	return copy_to_user(u, k, sizeof(struct termios));
+}
+#endif /* TCGETS2 */
+
+/**
+ *	set_termios		-	set termios values for a tty
+ *	@tty: terminal device
+ *	@arg: user data
+ *	@opt: option information
+ *
+ *	Helper function to prepare termios data and run necessary other
+ *	functions before using tty_set_termios to do the actual changes.
+ *
+ *	Locking:
+ *		Called functions take ldisc and termios_rwsem locks
+ */
+
+static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
+{
+	struct ktermios tmp_termios;
+	struct tty_ldisc *ld;
+	int retval = tty_check_change(tty);
+
+	if (retval)
+		return retval;
+
+	down_read(&tty->termios_rwsem);
+	tmp_termios = tty->termios;
+	up_read(&tty->termios_rwsem);
+
+	if (opt & TERMIOS_TERMIO) {
+		if (user_termio_to_kernel_termios(&tmp_termios,
+						(struct termio __user *)arg))
+			return -EFAULT;
+#ifdef TCGETS2
+	} else if (opt & TERMIOS_OLD) {
+		if (user_termios_to_kernel_termios_1(&tmp_termios,
+						(struct termios __user *)arg))
+			return -EFAULT;
+	} else {
+		if (user_termios_to_kernel_termios(&tmp_termios,
+						(struct termios2 __user *)arg))
+			return -EFAULT;
+	}
+#else
+	} else if (user_termios_to_kernel_termios(&tmp_termios,
+					(struct termios __user *)arg))
+		return -EFAULT;
+#endif
+
+	/* If old style Bfoo values are used then load c_ispeed/c_ospeed
+	 * with the real speed so its unconditionally usable */
+	tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
+	tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
+
+	if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) {
+retry_write_wait:
+		retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty));
+		if (retval < 0)
+			return retval;
+
+		if (tty_write_lock(tty, false) < 0)
+			goto retry_write_wait;
+
+		/* Racing writer? */
+		if (tty_chars_in_buffer(tty)) {
+			tty_write_unlock(tty);
+			goto retry_write_wait;
+		}
+
+		ld = tty_ldisc_ref(tty);
+		if (ld != NULL) {
+			if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+				ld->ops->flush_buffer(tty);
+			tty_ldisc_deref(ld);
+		}
+
+		if ((opt & TERMIOS_WAIT) && tty->ops->wait_until_sent) {
+			tty->ops->wait_until_sent(tty, 0);
+			if (signal_pending(current)) {
+				tty_write_unlock(tty);
+				return -ERESTARTSYS;
+			}
+		}
+
+		tty_set_termios(tty, &tmp_termios);
+
+		tty_write_unlock(tty);
+	} else {
+		tty_set_termios(tty, &tmp_termios);
+	}
+
+	/* FIXME: Arguably if tmp_termios == tty->termios AND the
+	   actual requested termios was not tmp_termios then we may
+	   want to return an error as no user requested change has
+	   succeeded */
+	return 0;
+}
+
+static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
+{
+	down_read(&tty->termios_rwsem);
+	*kterm = tty->termios;
+	up_read(&tty->termios_rwsem);
+}
+
+static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
+{
+	down_read(&tty->termios_rwsem);
+	*kterm = tty->termios_locked;
+	up_read(&tty->termios_rwsem);
+}
+
+static int get_termio(struct tty_struct *tty, struct termio __user *termio)
+{
+	struct ktermios kterm;
+	copy_termios(tty, &kterm);
+	if (kernel_termios_to_user_termio(termio, &kterm))
+		return -EFAULT;
+	return 0;
+}
+
+#ifdef TIOCGETP
+/*
+ * These are deprecated, but there is limited support..
+ *
+ * The "sg_flags" translation is a joke..
+ */
+static int get_sgflags(struct tty_struct *tty)
+{
+	int flags = 0;
+
+	if (!L_ICANON(tty)) {
+		if (L_ISIG(tty))
+			flags |= 0x02;		/* cbreak */
+		else
+			flags |= 0x20;		/* raw */
+	}
+	if (L_ECHO(tty))
+		flags |= 0x08;			/* echo */
+	if (O_OPOST(tty))
+		if (O_ONLCR(tty))
+			flags |= 0x10;		/* crmod */
+	return flags;
+}
+
+static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
+{
+	struct sgttyb tmp;
+
+	down_read(&tty->termios_rwsem);
+	tmp.sg_ispeed = tty->termios.c_ispeed;
+	tmp.sg_ospeed = tty->termios.c_ospeed;
+	tmp.sg_erase = tty->termios.c_cc[VERASE];
+	tmp.sg_kill = tty->termios.c_cc[VKILL];
+	tmp.sg_flags = get_sgflags(tty);
+	up_read(&tty->termios_rwsem);
+
+	return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static void set_sgflags(struct ktermios *termios, int flags)
+{
+	termios->c_iflag = ICRNL | IXON;
+	termios->c_oflag = 0;
+	termios->c_lflag = ISIG | ICANON;
+	if (flags & 0x02) {	/* cbreak */
+		termios->c_iflag = 0;
+		termios->c_lflag &= ~ICANON;
+	}
+	if (flags & 0x08) {		/* echo */
+		termios->c_lflag |= ECHO | ECHOE | ECHOK |
+				    ECHOCTL | ECHOKE | IEXTEN;
+	}
+	if (flags & 0x10) {		/* crmod */
+		termios->c_oflag |= OPOST | ONLCR;
+	}
+	if (flags & 0x20) {	/* raw */
+		termios->c_iflag = 0;
+		termios->c_lflag &= ~(ISIG | ICANON);
+	}
+	if (!(termios->c_lflag & ICANON)) {
+		termios->c_cc[VMIN] = 1;
+		termios->c_cc[VTIME] = 0;
+	}
+}
+
+/**
+ *	set_sgttyb		-	set legacy terminal values
+ *	@tty: tty structure
+ *	@sgttyb: pointer to old style terminal structure
+ *
+ *	Updates a terminal from the legacy BSD style terminal information
+ *	structure.
+ *
+ *	Locking: termios_rwsem
+ */
+
+static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
+{
+	int retval;
+	struct sgttyb tmp;
+	struct ktermios termios;
+
+	retval = tty_check_change(tty);
+	if (retval)
+		return retval;
+
+	if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
+		return -EFAULT;
+
+	down_write(&tty->termios_rwsem);
+	termios = tty->termios;
+	termios.c_cc[VERASE] = tmp.sg_erase;
+	termios.c_cc[VKILL] = tmp.sg_kill;
+	set_sgflags(&termios, tmp.sg_flags);
+	/* Try and encode into Bfoo format */
+	tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
+						termios.c_ospeed);
+	up_write(&tty->termios_rwsem);
+	tty_set_termios(tty, &termios);
+	return 0;
+}
+#endif
+
+#ifdef TIOCGETC
+static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
+{
+	struct tchars tmp;
+
+	down_read(&tty->termios_rwsem);
+	tmp.t_intrc = tty->termios.c_cc[VINTR];
+	tmp.t_quitc = tty->termios.c_cc[VQUIT];
+	tmp.t_startc = tty->termios.c_cc[VSTART];
+	tmp.t_stopc = tty->termios.c_cc[VSTOP];
+	tmp.t_eofc = tty->termios.c_cc[VEOF];
+	tmp.t_brkc = tty->termios.c_cc[VEOL2];	/* what is brkc anyway? */
+	up_read(&tty->termios_rwsem);
+	return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
+{
+	struct tchars tmp;
+
+	if (copy_from_user(&tmp, tchars, sizeof(tmp)))
+		return -EFAULT;
+	down_write(&tty->termios_rwsem);
+	tty->termios.c_cc[VINTR] = tmp.t_intrc;
+	tty->termios.c_cc[VQUIT] = tmp.t_quitc;
+	tty->termios.c_cc[VSTART] = tmp.t_startc;
+	tty->termios.c_cc[VSTOP] = tmp.t_stopc;
+	tty->termios.c_cc[VEOF] = tmp.t_eofc;
+	tty->termios.c_cc[VEOL2] = tmp.t_brkc;	/* what is brkc anyway? */
+	up_write(&tty->termios_rwsem);
+	return 0;
+}
+#endif
+
+#ifdef TIOCGLTC
+static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
+{
+	struct ltchars tmp;
+
+	down_read(&tty->termios_rwsem);
+	tmp.t_suspc = tty->termios.c_cc[VSUSP];
+	/* what is dsuspc anyway? */
+	tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
+	tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
+	/* what is flushc anyway? */
+	tmp.t_flushc = tty->termios.c_cc[VEOL2];
+	tmp.t_werasc = tty->termios.c_cc[VWERASE];
+	tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
+	up_read(&tty->termios_rwsem);
+	return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
+{
+	struct ltchars tmp;
+
+	if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
+		return -EFAULT;
+
+	down_write(&tty->termios_rwsem);
+	tty->termios.c_cc[VSUSP] = tmp.t_suspc;
+	/* what is dsuspc anyway? */
+	tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
+	tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
+	/* what is flushc anyway? */
+	tty->termios.c_cc[VEOL2] = tmp.t_flushc;
+	tty->termios.c_cc[VWERASE] = tmp.t_werasc;
+	tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
+	up_write(&tty->termios_rwsem);
+	return 0;
+}
+#endif
+
+/**
+ *	tty_change_softcar	-	carrier change ioctl helper
+ *	@tty: tty to update
+ *	@enable: enable/disable CLOCAL
+ *
+ *	Perform a change to the CLOCAL state and call into the driver
+ *	layer to make it visible. All done with the termios rwsem
+ */
+
+static int tty_change_softcar(struct tty_struct *tty, bool enable)
+{
+	int ret = 0;
+	struct ktermios old;
+	tcflag_t bit = enable ? CLOCAL : 0;
+
+	down_write(&tty->termios_rwsem);
+	old = tty->termios;
+	tty->termios.c_cflag &= ~CLOCAL;
+	tty->termios.c_cflag |= bit;
+	if (tty->ops->set_termios)
+		tty->ops->set_termios(tty, &old);
+	if (C_CLOCAL(tty) != bit)
+		ret = -EINVAL;
+	up_write(&tty->termios_rwsem);
+	return ret;
+}
+
+/**
+ *	tty_mode_ioctl		-	mode related ioctls
+ *	@tty: tty for the ioctl
+ *	@cmd: command
+ *	@arg: ioctl argument
+ *
+ *	Perform non line discipline specific mode control ioctls. This
+ *	is designed to be called by line disciplines to ensure they provide
+ *	consistent mode setting.
+ */
+
+int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
+{
+	struct tty_struct *real_tty;
+	void __user *p = (void __user *)arg;
+	int ret = 0;
+	struct ktermios kterm;
+
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		real_tty = tty->link;
+	else
+		real_tty = tty;
+
+	switch (cmd) {
+#ifdef TIOCGETP
+	case TIOCGETP:
+		return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
+	case TIOCSETP:
+	case TIOCSETN:
+		return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
+#endif
+#ifdef TIOCGETC
+	case TIOCGETC:
+		return get_tchars(real_tty, p);
+	case TIOCSETC:
+		return set_tchars(real_tty, p);
+#endif
+#ifdef TIOCGLTC
+	case TIOCGLTC:
+		return get_ltchars(real_tty, p);
+	case TIOCSLTC:
+		return set_ltchars(real_tty, p);
+#endif
+	case TCSETSF:
+		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
+	case TCSETSW:
+		return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
+	case TCSETS:
+		return set_termios(real_tty, p, TERMIOS_OLD);
+#ifndef TCGETS2
+	case TCGETS:
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+#else
+	case TCGETS:
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TCGETS2:
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TCSETSF2:
+		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
+	case TCSETSW2:
+		return set_termios(real_tty, p, TERMIOS_WAIT);
+	case TCSETS2:
+		return set_termios(real_tty, p, 0);
+#endif
+	case TCGETA:
+		return get_termio(real_tty, p);
+	case TCSETAF:
+		return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
+	case TCSETAW:
+		return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
+	case TCSETA:
+		return set_termios(real_tty, p, TERMIOS_TERMIO);
+#ifndef TCGETS2
+	case TIOCGLCKTRMIOS:
+		copy_termios_locked(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TIOCSLCKTRMIOS:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		copy_termios_locked(real_tty, &kterm);
+		if (user_termios_to_kernel_termios(&kterm,
+					       (struct termios __user *) arg))
+			return -EFAULT;
+		down_write(&real_tty->termios_rwsem);
+		real_tty->termios_locked = kterm;
+		up_write(&real_tty->termios_rwsem);
+		return 0;
+#else
+	case TIOCGLCKTRMIOS:
+		copy_termios_locked(real_tty, &kterm);
+		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TIOCSLCKTRMIOS:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		copy_termios_locked(real_tty, &kterm);
+		if (user_termios_to_kernel_termios_1(&kterm,
+					       (struct termios __user *) arg))
+			return -EFAULT;
+		down_write(&real_tty->termios_rwsem);
+		real_tty->termios_locked = kterm;
+		up_write(&real_tty->termios_rwsem);
+		return ret;
+#endif
+#ifdef TCGETX
+	case TCGETX:
+	case TCSETX:
+	case TCSETXW:
+	case TCSETXF:
+		return -ENOTTY;
+#endif
+	case TIOCGSOFTCAR:
+		copy_termios(real_tty, &kterm);
+		ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
+						(int __user *)arg);
+		return ret;
+	case TIOCSSOFTCAR:
+		if (get_user(arg, (unsigned int __user *) arg))
+			return -EFAULT;
+		return tty_change_softcar(real_tty, arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+EXPORT_SYMBOL_GPL(tty_mode_ioctl);
+
+
+/* Caller guarantees ldisc reference is held */
+static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
+{
+	struct tty_ldisc *ld = tty->ldisc;
+
+	switch (arg) {
+	case TCIFLUSH:
+		if (ld && ld->ops->flush_buffer) {
+			ld->ops->flush_buffer(tty);
+			tty_unthrottle(tty);
+		}
+		break;
+	case TCIOFLUSH:
+		if (ld && ld->ops->flush_buffer) {
+			ld->ops->flush_buffer(tty);
+			tty_unthrottle(tty);
+		}
+		fallthrough;
+	case TCOFLUSH:
+		tty_driver_flush_buffer(tty);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
+{
+	struct tty_ldisc *ld;
+	int retval = tty_check_change(tty);
+	if (retval)
+		return retval;
+
+	ld = tty_ldisc_ref_wait(tty);
+	retval = __tty_perform_flush(tty, arg);
+	if (ld)
+		tty_ldisc_deref(ld);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(tty_perform_flush);
+
+int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
+		unsigned long arg)
+{
+	int retval;
+
+	switch (cmd) {
+	case TCXONC:
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+		switch (arg) {
+		case TCOOFF:
+			spin_lock_irq(&tty->flow.lock);
+			if (!tty->flow.tco_stopped) {
+				tty->flow.tco_stopped = true;
+				__stop_tty(tty);
+			}
+			spin_unlock_irq(&tty->flow.lock);
+			break;
+		case TCOON:
+			spin_lock_irq(&tty->flow.lock);
+			if (tty->flow.tco_stopped) {
+				tty->flow.tco_stopped = false;
+				__start_tty(tty);
+			}
+			spin_unlock_irq(&tty->flow.lock);
+			break;
+		case TCIOFF:
+			if (STOP_CHAR(tty) != __DISABLED_CHAR)
+				retval = tty_send_xchar(tty, STOP_CHAR(tty));
+			break;
+		case TCION:
+			if (START_CHAR(tty) != __DISABLED_CHAR)
+				retval = tty_send_xchar(tty, START_CHAR(tty));
+			break;
+		default:
+			return -EINVAL;
+		}
+		return retval;
+	case TCFLSH:
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+		return __tty_perform_flush(tty, arg);
+	default:
+		/* Try the mode commands */
+		return tty_mode_ioctl(tty, cmd, arg);
+	}
+}
+EXPORT_SYMBOL(n_tty_ioctl_helper);
diff --git a/drivers/tty/tty_jobctrl.c b/drivers/tty/tty_jobctrl.c
new file mode 100644
index 000000000..ef8741c3e
--- /dev/null
+++ b/drivers/tty/tty_jobctrl.c
@@ -0,0 +1,593 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task.h>
+#include <linux/tty.h>
+#include <linux/fcntl.h>
+#include <linux/uaccess.h>
+#include "tty.h"
+
+static int is_ignored(int sig)
+{
+	return (sigismember(&current->blocked, sig) ||
+		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
+}
+
+/**
+ *	__tty_check_change	-	check for POSIX terminal changes
+ *	@tty: tty to check
+ *	@sig: signal to send
+ *
+ *	If we try to write to, or set the state of, a terminal and we're
+ *	not in the foreground, send a SIGTTOU.  If the signal is blocked or
+ *	ignored, go ahead and perform the operation.  (POSIX 7.2)
+ *
+ *	Locking: ctrl.lock
+ */
+int __tty_check_change(struct tty_struct *tty, int sig)
+{
+	unsigned long flags;
+	struct pid *pgrp, *tty_pgrp;
+	int ret = 0;
+
+	if (current->signal->tty != tty)
+		return 0;
+
+	rcu_read_lock();
+	pgrp = task_pgrp(current);
+
+	spin_lock_irqsave(&tty->ctrl.lock, flags);
+	tty_pgrp = tty->ctrl.pgrp;
+	spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+
+	if (tty_pgrp && pgrp != tty_pgrp) {
+		if (is_ignored(sig)) {
+			if (sig == SIGTTIN)
+				ret = -EIO;
+		} else if (is_current_pgrp_orphaned())
+			ret = -EIO;
+		else {
+			kill_pgrp(pgrp, sig, 1);
+			set_thread_flag(TIF_SIGPENDING);
+			ret = -ERESTARTSYS;
+		}
+	}
+	rcu_read_unlock();
+
+	if (!tty_pgrp)
+		tty_warn(tty, "sig=%d, tty->pgrp == NULL!\n", sig);
+
+	return ret;
+}
+
+int tty_check_change(struct tty_struct *tty)
+{
+	return __tty_check_change(tty, SIGTTOU);
+}
+EXPORT_SYMBOL(tty_check_change);
+
+void proc_clear_tty(struct task_struct *p)
+{
+	unsigned long flags;
+	struct tty_struct *tty;
+
+	spin_lock_irqsave(&p->sighand->siglock, flags);
+	tty = p->signal->tty;
+	p->signal->tty = NULL;
+	spin_unlock_irqrestore(&p->sighand->siglock, flags);
+	tty_kref_put(tty);
+}
+
+/**
+ * __proc_set_tty -  set the controlling terminal
+ *	@tty: tty structure
+ *
+ * Only callable by the session leader and only if it does not already have
+ * a controlling terminal.
+ *
+ * Caller must hold:  tty_lock()
+ *		      a readlock on tasklist_lock
+ *		      sighand lock
+ */
+static void __proc_set_tty(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->ctrl.lock, flags);
+	/*
+	 * The session and fg pgrp references will be non-NULL if
+	 * tiocsctty() is stealing the controlling tty
+	 */
+	put_pid(tty->ctrl.session);
+	put_pid(tty->ctrl.pgrp);
+	tty->ctrl.pgrp = get_pid(task_pgrp(current));
+	tty->ctrl.session = get_pid(task_session(current));
+	spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+	if (current->signal->tty) {
+		tty_debug(tty, "current tty %s not NULL!!\n",
+			  current->signal->tty->name);
+		tty_kref_put(current->signal->tty);
+	}
+	put_pid(current->signal->tty_old_pgrp);
+	current->signal->tty = tty_kref_get(tty);
+	current->signal->tty_old_pgrp = NULL;
+}
+
+static void proc_set_tty(struct tty_struct *tty)
+{
+	spin_lock_irq(&current->sighand->siglock);
+	__proc_set_tty(tty);
+	spin_unlock_irq(&current->sighand->siglock);
+}
+
+/*
+ * Called by tty_open() to set the controlling tty if applicable.
+ */
+void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty)
+{
+	read_lock(&tasklist_lock);
+	spin_lock_irq(&current->sighand->siglock);
+	if (current->signal->leader &&
+	    !current->signal->tty &&
+	    tty->ctrl.session == NULL) {
+		/*
+		 * Don't let a process that only has write access to the tty
+		 * obtain the privileges associated with having a tty as
+		 * controlling terminal (being able to reopen it with full
+		 * access through /dev/tty, being able to perform pushback).
+		 * Many distributions set the group of all ttys to "tty" and
+		 * grant write-only access to all terminals for setgid tty
+		 * binaries, which should not imply full privileges on all ttys.
+		 *
+		 * This could theoretically break old code that performs open()
+		 * on a write-only file descriptor. In that case, it might be
+		 * necessary to also permit this if
+		 * inode_permission(inode, MAY_READ) == 0.
+		 */
+		if (filp->f_mode & FMODE_READ)
+			__proc_set_tty(tty);
+	}
+	spin_unlock_irq(&current->sighand->siglock);
+	read_unlock(&tasklist_lock);
+}
+
+struct tty_struct *get_current_tty(void)
+{
+	struct tty_struct *tty;
+	unsigned long flags;
+
+	spin_lock_irqsave(&current->sighand->siglock, flags);
+	tty = tty_kref_get(current->signal->tty);
+	spin_unlock_irqrestore(&current->sighand->siglock, flags);
+	return tty;
+}
+EXPORT_SYMBOL_GPL(get_current_tty);
+
+/*
+ * Called from tty_release().
+ */
+void session_clear_tty(struct pid *session)
+{
+	struct task_struct *p;
+
+	do_each_pid_task(session, PIDTYPE_SID, p) {
+		proc_clear_tty(p);
+	} while_each_pid_task(session, PIDTYPE_SID, p);
+}
+
+/**
+ *	tty_signal_session_leader	- sends SIGHUP to session leader
+ *	@tty: controlling tty
+ *	@exit_session: if non-zero, signal all foreground group processes
+ *
+ *	Send SIGHUP and SIGCONT to the session leader and its process group.
+ *	Optionally, signal all processes in the foreground process group.
+ *
+ *	Returns the number of processes in the session with this tty
+ *	as their controlling terminal. This value is used to drop
+ *	tty references for those processes.
+ */
+int tty_signal_session_leader(struct tty_struct *tty, int exit_session)
+{
+	struct task_struct *p;
+	int refs = 0;
+	struct pid *tty_pgrp = NULL;
+
+	read_lock(&tasklist_lock);
+	if (tty->ctrl.session) {
+		do_each_pid_task(tty->ctrl.session, PIDTYPE_SID, p) {
+			spin_lock_irq(&p->sighand->siglock);
+			if (p->signal->tty == tty) {
+				p->signal->tty = NULL;
+				/*
+				 * We defer the dereferences outside of
+				 * the tasklist lock.
+				 */
+				refs++;
+			}
+			if (!p->signal->leader) {
+				spin_unlock_irq(&p->sighand->siglock);
+				continue;
+			}
+			send_signal_locked(SIGHUP, SEND_SIG_PRIV, p, PIDTYPE_TGID);
+			send_signal_locked(SIGCONT, SEND_SIG_PRIV, p, PIDTYPE_TGID);
+			put_pid(p->signal->tty_old_pgrp);  /* A noop */
+			spin_lock(&tty->ctrl.lock);
+			tty_pgrp = get_pid(tty->ctrl.pgrp);
+			if (tty->ctrl.pgrp)
+				p->signal->tty_old_pgrp =
+					get_pid(tty->ctrl.pgrp);
+			spin_unlock(&tty->ctrl.lock);
+			spin_unlock_irq(&p->sighand->siglock);
+		} while_each_pid_task(tty->ctrl.session, PIDTYPE_SID, p);
+	}
+	read_unlock(&tasklist_lock);
+
+	if (tty_pgrp) {
+		if (exit_session)
+			kill_pgrp(tty_pgrp, SIGHUP, exit_session);
+		put_pid(tty_pgrp);
+	}
+
+	return refs;
+}
+
+/**
+ *	disassociate_ctty	-	disconnect controlling tty
+ *	@on_exit: true if exiting so need to "hang up" the session
+ *
+ *	This function is typically called only by the session leader, when
+ *	it wants to disassociate itself from its controlling tty.
+ *
+ *	It performs the following functions:
+ *	(1)  Sends a SIGHUP and SIGCONT to the foreground process group
+ *	(2)  Clears the tty from being controlling the session
+ *	(3)  Clears the controlling tty for all processes in the
+ *		session group.
+ *
+ *	The argument on_exit is set to 1 if called when a process is
+ *	exiting; it is 0 if called by the ioctl TIOCNOTTY.
+ *
+ *	Locking:
+ *		BTM is taken for hysterical raisons, and held when
+ *		  called from no_tty().
+ *		  tty_mutex is taken to protect tty
+ *		  ->siglock is taken to protect ->signal/->sighand
+ *		  tasklist_lock is taken to walk process list for sessions
+ *		    ->siglock is taken to protect ->signal/->sighand
+ */
+void disassociate_ctty(int on_exit)
+{
+	struct tty_struct *tty;
+
+	if (!current->signal->leader)
+		return;
+
+	tty = get_current_tty();
+	if (tty) {
+		if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) {
+			tty_vhangup_session(tty);
+		} else {
+			struct pid *tty_pgrp = tty_get_pgrp(tty);
+
+			if (tty_pgrp) {
+				kill_pgrp(tty_pgrp, SIGHUP, on_exit);
+				if (!on_exit)
+					kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+				put_pid(tty_pgrp);
+			}
+		}
+		tty_kref_put(tty);
+
+	} else if (on_exit) {
+		struct pid *old_pgrp;
+
+		spin_lock_irq(&current->sighand->siglock);
+		old_pgrp = current->signal->tty_old_pgrp;
+		current->signal->tty_old_pgrp = NULL;
+		spin_unlock_irq(&current->sighand->siglock);
+		if (old_pgrp) {
+			kill_pgrp(old_pgrp, SIGHUP, on_exit);
+			kill_pgrp(old_pgrp, SIGCONT, on_exit);
+			put_pid(old_pgrp);
+		}
+		return;
+	}
+
+	tty = get_current_tty();
+	if (tty) {
+		unsigned long flags;
+
+		tty_lock(tty);
+		spin_lock_irqsave(&tty->ctrl.lock, flags);
+		put_pid(tty->ctrl.session);
+		put_pid(tty->ctrl.pgrp);
+		tty->ctrl.session = NULL;
+		tty->ctrl.pgrp = NULL;
+		spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+		tty_unlock(tty);
+		tty_kref_put(tty);
+	}
+
+	/* If tty->ctrl.pgrp is not NULL, it may be assigned to
+	 * current->signal->tty_old_pgrp in a race condition, and
+	 * cause pid memleak. Release current->signal->tty_old_pgrp
+	 * after tty->ctrl.pgrp set to NULL.
+	 */
+	spin_lock_irq(&current->sighand->siglock);
+	put_pid(current->signal->tty_old_pgrp);
+	current->signal->tty_old_pgrp = NULL;
+	spin_unlock_irq(&current->sighand->siglock);
+
+	/* Now clear signal->tty under the lock */
+	read_lock(&tasklist_lock);
+	session_clear_tty(task_session(current));
+	read_unlock(&tasklist_lock);
+}
+
+/*
+ *
+ *	no_tty	- Ensure the current process does not have a controlling tty
+ */
+void no_tty(void)
+{
+	/*
+	 * FIXME: Review locking here. The tty_lock never covered any race
+	 * between a new association and proc_clear_tty but possibly we need
+	 * to protect against this anyway.
+	 */
+	struct task_struct *tsk = current;
+
+	disassociate_ctty(0);
+	proc_clear_tty(tsk);
+}
+
+/**
+ *	tiocsctty	-	set controlling tty
+ *	@tty: tty structure
+ *	@file: file structure used to check permissions
+ *	@arg: user argument
+ *
+ *	This ioctl is used to manage job control. It permits a session
+ *	leader to set this tty as the controlling tty for the session.
+ *
+ *	Locking:
+ *		Takes tty_lock() to serialize proc_set_tty() for this tty
+ *		Takes tasklist_lock internally to walk sessions
+ *		Takes ->siglock() when updating signal->tty
+ */
+static int tiocsctty(struct tty_struct *tty, struct file *file, int arg)
+{
+	int ret = 0;
+
+	tty_lock(tty);
+	read_lock(&tasklist_lock);
+
+	if (current->signal->leader &&
+			task_session(current) == tty->ctrl.session)
+		goto unlock;
+
+	/*
+	 * The process must be a session leader and
+	 * not have a controlling tty already.
+	 */
+	if (!current->signal->leader || current->signal->tty) {
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	if (tty->ctrl.session) {
+		/*
+		 * This tty is already the controlling
+		 * tty for another session group!
+		 */
+		if (arg == 1 && capable(CAP_SYS_ADMIN)) {
+			/*
+			 * Steal it away
+			 */
+			session_clear_tty(tty->ctrl.session);
+		} else {
+			ret = -EPERM;
+			goto unlock;
+		}
+	}
+
+	/* See the comment in tty_open_proc_set_tty(). */
+	if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) {
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	proc_set_tty(tty);
+unlock:
+	read_unlock(&tasklist_lock);
+	tty_unlock(tty);
+	return ret;
+}
+
+/**
+ *	tty_get_pgrp	-	return a ref counted pgrp pid
+ *	@tty: tty to read
+ *
+ *	Returns a refcounted instance of the pid struct for the process
+ *	group controlling the tty.
+ */
+struct pid *tty_get_pgrp(struct tty_struct *tty)
+{
+	unsigned long flags;
+	struct pid *pgrp;
+
+	spin_lock_irqsave(&tty->ctrl.lock, flags);
+	pgrp = get_pid(tty->ctrl.pgrp);
+	spin_unlock_irqrestore(&tty->ctrl.lock, flags);
+
+	return pgrp;
+}
+EXPORT_SYMBOL_GPL(tty_get_pgrp);
+
+/*
+ * This checks not only the pgrp, but falls back on the pid if no
+ * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
+ * without this...
+ *
+ * The caller must hold rcu lock or the tasklist lock.
+ */
+static struct pid *session_of_pgrp(struct pid *pgrp)
+{
+	struct task_struct *p;
+	struct pid *sid = NULL;
+
+	p = pid_task(pgrp, PIDTYPE_PGID);
+	if (p == NULL)
+		p = pid_task(pgrp, PIDTYPE_PID);
+	if (p != NULL)
+		sid = task_session(p);
+
+	return sid;
+}
+
+/**
+ *	tiocgpgrp		-	get process group
+ *	@tty: tty passed by user
+ *	@real_tty: tty side of the tty passed by the user if a pty else the tty
+ *	@p: returned pid
+ *
+ *	Obtain the process group of the tty. If there is no process group
+ *	return an error.
+ *
+ *	Locking: none. Reference to current->signal->tty is safe.
+ */
+static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	struct pid *pid;
+	int ret;
+	/*
+	 * (tty == real_tty) is a cheap way of
+	 * testing if the tty is NOT a master pty.
+	 */
+	if (tty == real_tty && current->signal->tty != real_tty)
+		return -ENOTTY;
+	pid = tty_get_pgrp(real_tty);
+	ret =  put_user(pid_vnr(pid), p);
+	put_pid(pid);
+	return ret;
+}
+
+/**
+ *	tiocspgrp		-	attempt to set process group
+ *	@tty: tty passed by user
+ *	@real_tty: tty side device matching tty passed by user
+ *	@p: pid pointer
+ *
+ *	Set the process group of the tty to the session passed. Only
+ *	permitted where the tty session is our session.
+ *
+ *	Locking: RCU, ctrl lock
+ */
+static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	struct pid *pgrp;
+	pid_t pgrp_nr;
+	int retval = tty_check_change(real_tty);
+
+	if (retval == -EIO)
+		return -ENOTTY;
+	if (retval)
+		return retval;
+
+	if (get_user(pgrp_nr, p))
+		return -EFAULT;
+	if (pgrp_nr < 0)
+		return -EINVAL;
+
+	spin_lock_irq(&real_tty->ctrl.lock);
+	if (!current->signal->tty ||
+	    (current->signal->tty != real_tty) ||
+	    (real_tty->ctrl.session != task_session(current))) {
+		retval = -ENOTTY;
+		goto out_unlock_ctrl;
+	}
+	rcu_read_lock();
+	pgrp = find_vpid(pgrp_nr);
+	retval = -ESRCH;
+	if (!pgrp)
+		goto out_unlock;
+	retval = -EPERM;
+	if (session_of_pgrp(pgrp) != task_session(current))
+		goto out_unlock;
+	retval = 0;
+	put_pid(real_tty->ctrl.pgrp);
+	real_tty->ctrl.pgrp = get_pid(pgrp);
+out_unlock:
+	rcu_read_unlock();
+out_unlock_ctrl:
+	spin_unlock_irq(&real_tty->ctrl.lock);
+	return retval;
+}
+
+/**
+ *	tiocgsid		-	get session id
+ *	@tty: tty passed by user
+ *	@real_tty: tty side of the tty passed by the user if a pty else the tty
+ *	@p: pointer to returned session id
+ *
+ *	Obtain the session id of the tty. If there is no session
+ *	return an error.
+ */
+static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	unsigned long flags;
+	pid_t sid;
+
+	/*
+	 * (tty == real_tty) is a cheap way of
+	 * testing if the tty is NOT a master pty.
+	 */
+	if (tty == real_tty && current->signal->tty != real_tty)
+		return -ENOTTY;
+
+	spin_lock_irqsave(&real_tty->ctrl.lock, flags);
+	if (!real_tty->ctrl.session)
+		goto err;
+	sid = pid_vnr(real_tty->ctrl.session);
+	spin_unlock_irqrestore(&real_tty->ctrl.lock, flags);
+
+	return put_user(sid, p);
+
+err:
+	spin_unlock_irqrestore(&real_tty->ctrl.lock, flags);
+	return -ENOTTY;
+}
+
+/*
+ * Called from tty_ioctl(). If tty is a pty then real_tty is the slave side,
+ * if not then tty == real_tty.
+ */
+long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
+		       struct file *file, unsigned int cmd, unsigned long arg)
+{
+	void __user *p = (void __user *)arg;
+
+	switch (cmd) {
+	case TIOCNOTTY:
+		if (current->signal->tty != tty)
+			return -ENOTTY;
+		no_tty();
+		return 0;
+	case TIOCSCTTY:
+		return tiocsctty(real_tty, file, arg);
+	case TIOCGPGRP:
+		return tiocgpgrp(tty, real_tty, p);
+	case TIOCSPGRP:
+		return tiocspgrp(tty, real_tty, p);
+	case TIOCGSID:
+		return tiocgsid(tty, real_tty, p);
+	}
+	return -ENOIOCTLCMD;
+}
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
new file mode 100644
index 000000000..3f68e213d
--- /dev/null
+++ b/drivers/tty/tty_ldisc.c
@@ -0,0 +1,818 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kmod.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/ratelimit.h>
+#include "tty.h"
+
+#undef LDISC_DEBUG_HANGUP
+
+#ifdef LDISC_DEBUG_HANGUP
+#define tty_ldisc_debug(tty, f, args...)	tty_debug(tty, f, ##args)
+#else
+#define tty_ldisc_debug(tty, f, args...)
+#endif
+
+/* lockdep nested classes for tty->ldisc_sem */
+enum {
+	LDISC_SEM_NORMAL,
+	LDISC_SEM_OTHER,
+};
+
+
+/*
+ *	This guards the refcounted line discipline lists. The lock
+ *	must be taken with irqs off because there are hangup path
+ *	callers who will do ldisc lookups and cannot sleep.
+ */
+
+static DEFINE_RAW_SPINLOCK(tty_ldiscs_lock);
+/* Line disc dispatch table */
+static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
+
+/**
+ * tty_register_ldisc	-	install a line discipline
+ * @new_ldisc: pointer to the ldisc object
+ *
+ * Installs a new line discipline into the kernel. The discipline is set up as
+ * unreferenced and then made available to the kernel from this point onwards.
+ *
+ * Locking: takes %tty_ldiscs_lock to guard against ldisc races
+ */
+int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
+{
+	unsigned long flags;
+
+	if (new_ldisc->num < N_TTY || new_ldisc->num >= NR_LDISCS)
+		return -EINVAL;
+
+	raw_spin_lock_irqsave(&tty_ldiscs_lock, flags);
+	tty_ldiscs[new_ldisc->num] = new_ldisc;
+	raw_spin_unlock_irqrestore(&tty_ldiscs_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(tty_register_ldisc);
+
+/**
+ * tty_unregister_ldisc	-	unload a line discipline
+ * @ldisc: ldisc number
+ *
+ * Remove a line discipline from the kernel providing it is not currently in
+ * use.
+ *
+ * Locking: takes %tty_ldiscs_lock to guard against ldisc races
+ */
+
+void tty_unregister_ldisc(struct tty_ldisc_ops *ldisc)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&tty_ldiscs_lock, flags);
+	tty_ldiscs[ldisc->num] = NULL;
+	raw_spin_unlock_irqrestore(&tty_ldiscs_lock, flags);
+}
+EXPORT_SYMBOL(tty_unregister_ldisc);
+
+static struct tty_ldisc_ops *get_ldops(int disc)
+{
+	unsigned long flags;
+	struct tty_ldisc_ops *ldops, *ret;
+
+	raw_spin_lock_irqsave(&tty_ldiscs_lock, flags);
+	ret = ERR_PTR(-EINVAL);
+	ldops = tty_ldiscs[disc];
+	if (ldops) {
+		ret = ERR_PTR(-EAGAIN);
+		if (try_module_get(ldops->owner))
+			ret = ldops;
+	}
+	raw_spin_unlock_irqrestore(&tty_ldiscs_lock, flags);
+	return ret;
+}
+
+static void put_ldops(struct tty_ldisc_ops *ldops)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&tty_ldiscs_lock, flags);
+	module_put(ldops->owner);
+	raw_spin_unlock_irqrestore(&tty_ldiscs_lock, flags);
+}
+
+int tty_ldisc_autoload = IS_BUILTIN(CONFIG_LDISC_AUTOLOAD);
+
+/**
+ * tty_ldisc_get	-	take a reference to an ldisc
+ * @tty: tty device
+ * @disc: ldisc number
+ *
+ * Takes a reference to a line discipline. Deals with refcounts and module
+ * locking counts. If the discipline is not available, its module loaded, if
+ * possible.
+ *
+ * Returns:
+ * * -%EINVAL if the discipline index is not [%N_TTY .. %NR_LDISCS] or if the
+ *   discipline is not registered
+ * * -%EAGAIN if request_module() failed to load or register the discipline
+ * * -%ENOMEM if allocation failure
+ * * Otherwise, returns a pointer to the discipline and bumps the ref count
+ *
+ * Locking: takes %tty_ldiscs_lock to guard against ldisc races
+ */
+static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
+{
+	struct tty_ldisc *ld;
+	struct tty_ldisc_ops *ldops;
+
+	if (disc < N_TTY || disc >= NR_LDISCS)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * Get the ldisc ops - we may need to request them to be loaded
+	 * dynamically and try again.
+	 */
+	ldops = get_ldops(disc);
+	if (IS_ERR(ldops)) {
+		if (!capable(CAP_SYS_MODULE) && !tty_ldisc_autoload)
+			return ERR_PTR(-EPERM);
+		request_module("tty-ldisc-%d", disc);
+		ldops = get_ldops(disc);
+		if (IS_ERR(ldops))
+			return ERR_CAST(ldops);
+	}
+
+	/*
+	 * There is no way to handle allocation failure of only 16 bytes.
+	 * Let's simplify error handling and save more memory.
+	 */
+	ld = kmalloc(sizeof(struct tty_ldisc), GFP_KERNEL | __GFP_NOFAIL);
+	ld->ops = ldops;
+	ld->tty = tty;
+
+	return ld;
+}
+
+/**
+ * tty_ldisc_put	-	release the ldisc
+ * @ld: lisdsc to release
+ *
+ * Complement of tty_ldisc_get().
+ */
+static void tty_ldisc_put(struct tty_ldisc *ld)
+{
+	if (WARN_ON_ONCE(!ld))
+		return;
+
+	put_ldops(ld->ops);
+	kfree(ld);
+}
+
+static void *tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
+{
+	return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void *tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
+{
+	int i = *(loff_t *)v;
+	struct tty_ldisc_ops *ldops;
+
+	ldops = get_ldops(i);
+	if (IS_ERR(ldops))
+		return 0;
+	seq_printf(m, "%-10s %2d\n", ldops->name ? ldops->name : "???", i);
+	put_ldops(ldops);
+	return 0;
+}
+
+const struct seq_operations tty_ldiscs_seq_ops = {
+	.start	= tty_ldiscs_seq_start,
+	.next	= tty_ldiscs_seq_next,
+	.stop	= tty_ldiscs_seq_stop,
+	.show	= tty_ldiscs_seq_show,
+};
+
+/**
+ * tty_ldisc_ref_wait	-	wait for the tty ldisc
+ * @tty: tty device
+ *
+ * Dereference the line discipline for the terminal and take a reference to it.
+ * If the line discipline is in flux then wait patiently until it changes.
+ *
+ * Returns: %NULL if the tty has been hungup and not re-opened with a new file
+ * descriptor, otherwise valid ldisc reference
+ *
+ * Note 1: Must not be called from an IRQ/timer context. The caller must also
+ * be careful not to hold other locks that will deadlock against a discipline
+ * change, such as an existing ldisc reference (which we check for).
+ *
+ * Note 2: a file_operations routine (read/poll/write) should use this function
+ * to wait for any ldisc lifetime events to finish.
+ */
+struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+
+	ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT);
+	ld = tty->ldisc;
+	if (!ld)
+		ldsem_up_read(&tty->ldisc_sem);
+	return ld;
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
+
+/**
+ * tty_ldisc_ref	-	get the tty ldisc
+ * @tty: tty device
+ *
+ * Dereference the line discipline for the terminal and take a reference to it.
+ * If the line discipline is in flux then return %NULL. Can be called from IRQ
+ * and timer functions.
+ */
+struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld = NULL;
+
+	if (ldsem_down_read_trylock(&tty->ldisc_sem)) {
+		ld = tty->ldisc;
+		if (!ld)
+			ldsem_up_read(&tty->ldisc_sem);
+	}
+	return ld;
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_ref);
+
+/**
+ * tty_ldisc_deref	-	free a tty ldisc reference
+ * @ld: reference to free up
+ *
+ * Undoes the effect of tty_ldisc_ref() or tty_ldisc_ref_wait(). May be called
+ * in IRQ context.
+ */
+void tty_ldisc_deref(struct tty_ldisc *ld)
+{
+	ldsem_up_read(&ld->tty->ldisc_sem);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_deref);
+
+
+static inline int
+__tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
+{
+	return ldsem_down_write(&tty->ldisc_sem, timeout);
+}
+
+static inline int
+__tty_ldisc_lock_nested(struct tty_struct *tty, unsigned long timeout)
+{
+	return ldsem_down_write_nested(&tty->ldisc_sem,
+				       LDISC_SEM_OTHER, timeout);
+}
+
+static inline void __tty_ldisc_unlock(struct tty_struct *tty)
+{
+	ldsem_up_write(&tty->ldisc_sem);
+}
+
+int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
+{
+	int ret;
+
+	/* Kindly asking blocked readers to release the read side */
+	set_bit(TTY_LDISC_CHANGING, &tty->flags);
+	wake_up_interruptible_all(&tty->read_wait);
+	wake_up_interruptible_all(&tty->write_wait);
+
+	ret = __tty_ldisc_lock(tty, timeout);
+	if (!ret)
+		return -EBUSY;
+	set_bit(TTY_LDISC_HALTED, &tty->flags);
+	return 0;
+}
+
+void tty_ldisc_unlock(struct tty_struct *tty)
+{
+	clear_bit(TTY_LDISC_HALTED, &tty->flags);
+	/* Can be cleared here - ldisc_unlock will wake up writers firstly */
+	clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+	__tty_ldisc_unlock(tty);
+}
+
+static int
+tty_ldisc_lock_pair_timeout(struct tty_struct *tty, struct tty_struct *tty2,
+			    unsigned long timeout)
+{
+	int ret;
+
+	if (tty < tty2) {
+		ret = __tty_ldisc_lock(tty, timeout);
+		if (ret) {
+			ret = __tty_ldisc_lock_nested(tty2, timeout);
+			if (!ret)
+				__tty_ldisc_unlock(tty);
+		}
+	} else {
+		/* if this is possible, it has lots of implications */
+		WARN_ON_ONCE(tty == tty2);
+		if (tty2 && tty != tty2) {
+			ret = __tty_ldisc_lock(tty2, timeout);
+			if (ret) {
+				ret = __tty_ldisc_lock_nested(tty, timeout);
+				if (!ret)
+					__tty_ldisc_unlock(tty2);
+			}
+		} else
+			ret = __tty_ldisc_lock(tty, timeout);
+	}
+
+	if (!ret)
+		return -EBUSY;
+
+	set_bit(TTY_LDISC_HALTED, &tty->flags);
+	if (tty2)
+		set_bit(TTY_LDISC_HALTED, &tty2->flags);
+	return 0;
+}
+
+static void tty_ldisc_lock_pair(struct tty_struct *tty, struct tty_struct *tty2)
+{
+	tty_ldisc_lock_pair_timeout(tty, tty2, MAX_SCHEDULE_TIMEOUT);
+}
+
+static void tty_ldisc_unlock_pair(struct tty_struct *tty,
+				  struct tty_struct *tty2)
+{
+	__tty_ldisc_unlock(tty);
+	if (tty2)
+		__tty_ldisc_unlock(tty2);
+}
+
+/**
+ * tty_ldisc_flush		-	flush line discipline queue
+ * @tty: tty to flush ldisc for
+ *
+ * Flush the line discipline queue (if any) and the tty flip buffers for this
+ * @tty.
+ */
+void tty_ldisc_flush(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld = tty_ldisc_ref(tty);
+
+	tty_buffer_flush(tty, ld);
+	if (ld)
+		tty_ldisc_deref(ld);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+
+/**
+ * tty_set_termios_ldisc	-	set ldisc field
+ * @tty: tty structure
+ * @disc: line discipline number
+ *
+ * This is probably overkill for real world processors but they are not on hot
+ * paths so a little discipline won't do any harm.
+ *
+ * The line discipline-related tty_struct fields are reset to prevent the ldisc
+ * driver from re-using stale information for the new ldisc instance.
+ *
+ * Locking: takes termios_rwsem
+ */
+static void tty_set_termios_ldisc(struct tty_struct *tty, int disc)
+{
+	down_write(&tty->termios_rwsem);
+	tty->termios.c_line = disc;
+	up_write(&tty->termios_rwsem);
+
+	tty->disc_data = NULL;
+	tty->receive_room = 0;
+}
+
+/**
+ * tty_ldisc_open		-	open a line discipline
+ * @tty: tty we are opening the ldisc on
+ * @ld: discipline to open
+ *
+ * A helper opening method. Also a convenient debugging and check point.
+ *
+ * Locking: always called with BTM already held.
+ */
+static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
+	if (ld->ops->open) {
+		int ret;
+		/* BTM here locks versus a hangup event */
+		ret = ld->ops->open(tty);
+		if (ret)
+			clear_bit(TTY_LDISC_OPEN, &tty->flags);
+
+		tty_ldisc_debug(tty, "%p: opened\n", ld);
+		return ret;
+	}
+	return 0;
+}
+
+/**
+ * tty_ldisc_close		-	close a line discipline
+ * @tty: tty we are opening the ldisc on
+ * @ld: discipline to close
+ *
+ * A helper close method. Also a convenient debugging and check point.
+ */
+static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	lockdep_assert_held_write(&tty->ldisc_sem);
+	WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));
+	clear_bit(TTY_LDISC_OPEN, &tty->flags);
+	if (ld->ops->close)
+		ld->ops->close(tty);
+	tty_ldisc_debug(tty, "%p: closed\n", ld);
+}
+
+/**
+ * tty_ldisc_failto	-	helper for ldisc failback
+ * @tty: tty to open the ldisc on
+ * @ld: ldisc we are trying to fail back to
+ *
+ * Helper to try and recover a tty when switching back to the old ldisc fails
+ * and we need something attached.
+ */
+static int tty_ldisc_failto(struct tty_struct *tty, int ld)
+{
+	struct tty_ldisc *disc = tty_ldisc_get(tty, ld);
+	int r;
+
+	lockdep_assert_held_write(&tty->ldisc_sem);
+	if (IS_ERR(disc))
+		return PTR_ERR(disc);
+	tty->ldisc = disc;
+	tty_set_termios_ldisc(tty, ld);
+	r = tty_ldisc_open(tty, disc);
+	if (r < 0)
+		tty_ldisc_put(disc);
+	return r;
+}
+
+/**
+ * tty_ldisc_restore	-	helper for tty ldisc change
+ * @tty: tty to recover
+ * @old: previous ldisc
+ *
+ * Restore the previous line discipline or %N_TTY when a line discipline change
+ * fails due to an open error
+ */
+static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
+{
+	/* There is an outstanding reference here so this is safe */
+	if (tty_ldisc_failto(tty, old->ops->num) < 0) {
+		const char *name = tty_name(tty);
+
+		pr_warn("Falling back ldisc for %s.\n", name);
+		/*
+		 * The traditional behaviour is to fall back to N_TTY, we
+		 * want to avoid falling back to N_NULL unless we have no
+		 * choice to avoid the risk of breaking anything
+		 */
+		if (tty_ldisc_failto(tty, N_TTY) < 0 &&
+		    tty_ldisc_failto(tty, N_NULL) < 0)
+			panic("Couldn't open N_NULL ldisc for %s.", name);
+	}
+}
+
+/**
+ * tty_set_ldisc		-	set line discipline
+ * @tty: the terminal to set
+ * @disc: the line discipline number
+ *
+ * Set the discipline of a tty line. Must be called from a process context. The
+ * ldisc change logic has to protect itself against any overlapping ldisc
+ * change (including on the other end of pty pairs), the close of one side of a
+ * tty/pty pair, and eventually hangup.
+ */
+int tty_set_ldisc(struct tty_struct *tty, int disc)
+{
+	int retval;
+	struct tty_ldisc *old_ldisc, *new_ldisc;
+
+	new_ldisc = tty_ldisc_get(tty, disc);
+	if (IS_ERR(new_ldisc))
+		return PTR_ERR(new_ldisc);
+
+	tty_lock(tty);
+	retval = tty_ldisc_lock(tty, 5 * HZ);
+	if (retval)
+		goto err;
+
+	if (!tty->ldisc) {
+		retval = -EIO;
+		goto out;
+	}
+
+	/* Check the no-op case */
+	if (tty->ldisc->ops->num == disc)
+		goto out;
+
+	if (test_bit(TTY_HUPPED, &tty->flags)) {
+		/* We were raced by hangup */
+		retval = -EIO;
+		goto out;
+	}
+
+	old_ldisc = tty->ldisc;
+
+	/* Shutdown the old discipline. */
+	tty_ldisc_close(tty, old_ldisc);
+
+	/* Now set up the new line discipline. */
+	tty->ldisc = new_ldisc;
+	tty_set_termios_ldisc(tty, disc);
+
+	retval = tty_ldisc_open(tty, new_ldisc);
+	if (retval < 0) {
+		/* Back to the old one or N_TTY if we can't */
+		tty_ldisc_put(new_ldisc);
+		tty_ldisc_restore(tty, old_ldisc);
+	}
+
+	if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) {
+		down_read(&tty->termios_rwsem);
+		tty->ops->set_ldisc(tty);
+		up_read(&tty->termios_rwsem);
+	}
+
+	/*
+	 * At this point we hold a reference to the new ldisc and a
+	 * reference to the old ldisc, or we hold two references to
+	 * the old ldisc (if it was restored as part of error cleanup
+	 * above). In either case, releasing a single reference from
+	 * the old ldisc is correct.
+	 */
+	new_ldisc = old_ldisc;
+out:
+	tty_ldisc_unlock(tty);
+
+	/*
+	 * Restart the work queue in case no characters kick it off. Safe if
+	 * already running
+	 */
+	tty_buffer_restart_work(tty->port);
+err:
+	tty_ldisc_put(new_ldisc);	/* drop the extra reference */
+	tty_unlock(tty);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(tty_set_ldisc);
+
+/**
+ * tty_ldisc_kill	-	teardown ldisc
+ * @tty: tty being released
+ *
+ * Perform final close of the ldisc and reset @tty->ldisc
+ */
+static void tty_ldisc_kill(struct tty_struct *tty)
+{
+	lockdep_assert_held_write(&tty->ldisc_sem);
+	if (!tty->ldisc)
+		return;
+	/*
+	 * Now kill off the ldisc
+	 */
+	tty_ldisc_close(tty, tty->ldisc);
+	tty_ldisc_put(tty->ldisc);
+	/* Force an oops if we mess this up */
+	tty->ldisc = NULL;
+}
+
+/**
+ * tty_reset_termios	-	reset terminal state
+ * @tty: tty to reset
+ *
+ * Restore a terminal to the driver default state.
+ */
+static void tty_reset_termios(struct tty_struct *tty)
+{
+	down_write(&tty->termios_rwsem);
+	tty->termios = tty->driver->init_termios;
+	tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
+	tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
+	up_write(&tty->termios_rwsem);
+}
+
+
+/**
+ * tty_ldisc_reinit	-	reinitialise the tty ldisc
+ * @tty: tty to reinit
+ * @disc: line discipline to reinitialize
+ *
+ * Completely reinitialize the line discipline state, by closing the current
+ * instance, if there is one, and opening a new instance. If an error occurs
+ * opening the new non-%N_TTY instance, the instance is dropped and @tty->ldisc
+ * reset to %NULL. The caller can then retry with %N_TTY instead.
+ *
+ * Returns: 0 if successful, otherwise error code < 0
+ */
+int tty_ldisc_reinit(struct tty_struct *tty, int disc)
+{
+	struct tty_ldisc *ld;
+	int retval;
+
+	lockdep_assert_held_write(&tty->ldisc_sem);
+	ld = tty_ldisc_get(tty, disc);
+	if (IS_ERR(ld)) {
+		BUG_ON(disc == N_TTY);
+		return PTR_ERR(ld);
+	}
+
+	if (tty->ldisc) {
+		tty_ldisc_close(tty, tty->ldisc);
+		tty_ldisc_put(tty->ldisc);
+	}
+
+	/* switch the line discipline */
+	tty->ldisc = ld;
+	tty_set_termios_ldisc(tty, disc);
+	retval = tty_ldisc_open(tty, tty->ldisc);
+	if (retval) {
+		tty_ldisc_put(tty->ldisc);
+		tty->ldisc = NULL;
+	}
+	return retval;
+}
+
+/**
+ * tty_ldisc_hangup	-	hangup ldisc reset
+ * @tty: tty being hung up
+ * @reinit: whether to re-initialise the tty
+ *
+ * Some tty devices reset their termios when they receive a hangup event. In
+ * that situation we must also switch back to %N_TTY properly before we reset
+ * the termios data.
+ *
+ * Locking: We can take the ldisc mutex as the rest of the code is careful to
+ * allow for this.
+ *
+ * In the pty pair case this occurs in the close() path of the tty itself so we
+ * must be careful about locking rules.
+ */
+void tty_ldisc_hangup(struct tty_struct *tty, bool reinit)
+{
+	struct tty_ldisc *ld;
+
+	tty_ldisc_debug(tty, "%p: hangup\n", tty->ldisc);
+
+	ld = tty_ldisc_ref(tty);
+	if (ld != NULL) {
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_driver_flush_buffer(tty);
+		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
+		    ld->ops->write_wakeup)
+			ld->ops->write_wakeup(tty);
+		if (ld->ops->hangup)
+			ld->ops->hangup(tty);
+		tty_ldisc_deref(ld);
+	}
+
+	wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
+	wake_up_interruptible_poll(&tty->read_wait, EPOLLIN);
+
+	/*
+	 * Shutdown the current line discipline, and reset it to
+	 * N_TTY if need be.
+	 *
+	 * Avoid racing set_ldisc or tty_ldisc_release
+	 */
+	tty_ldisc_lock(tty, MAX_SCHEDULE_TIMEOUT);
+
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+		tty_reset_termios(tty);
+
+	if (tty->ldisc) {
+		if (reinit) {
+			if (tty_ldisc_reinit(tty, tty->termios.c_line) < 0 &&
+			    tty_ldisc_reinit(tty, N_TTY) < 0)
+				WARN_ON(tty_ldisc_reinit(tty, N_NULL) < 0);
+		} else
+			tty_ldisc_kill(tty);
+	}
+	tty_ldisc_unlock(tty);
+}
+
+/**
+ * tty_ldisc_setup	-	open line discipline
+ * @tty: tty being shut down
+ * @o_tty: pair tty for pty/tty pairs
+ *
+ * Called during the initial open of a tty/pty pair in order to set up the line
+ * disciplines and bind them to the @tty. This has no locking issues as the
+ * device isn't yet active.
+ */
+int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
+{
+	int retval = tty_ldisc_open(tty, tty->ldisc);
+
+	if (retval)
+		return retval;
+
+	if (o_tty) {
+		/*
+		 * Called without o_tty->ldisc_sem held, as o_tty has been
+		 * just allocated and no one has a reference to it.
+		 */
+		retval = tty_ldisc_open(o_tty, o_tty->ldisc);
+		if (retval) {
+			tty_ldisc_close(tty, tty->ldisc);
+			return retval;
+		}
+	}
+	return 0;
+}
+
+/**
+ * tty_ldisc_release	-	release line discipline
+ * @tty: tty being shut down (or one end of pty pair)
+ *
+ * Called during the final close of a tty or a pty pair in order to shut down
+ * the line discpline layer. On exit, each tty's ldisc is %NULL.
+ */
+void tty_ldisc_release(struct tty_struct *tty)
+{
+	struct tty_struct *o_tty = tty->link;
+
+	/*
+	 * Shutdown this line discipline. As this is the final close,
+	 * it does not race with the set_ldisc code path.
+	 */
+
+	tty_ldisc_lock_pair(tty, o_tty);
+	tty_ldisc_kill(tty);
+	if (o_tty)
+		tty_ldisc_kill(o_tty);
+	tty_ldisc_unlock_pair(tty, o_tty);
+
+	/*
+	 * And the memory resources remaining (buffers, termios) will be
+	 * disposed of when the kref hits zero
+	 */
+
+	tty_ldisc_debug(tty, "released\n");
+}
+
+/**
+ * tty_ldisc_init	-	ldisc setup for new tty
+ * @tty: tty being allocated
+ *
+ * Set up the line discipline objects for a newly allocated tty. Note that the
+ * tty structure is not completely set up when this call is made.
+ */
+int tty_ldisc_init(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld = tty_ldisc_get(tty, N_TTY);
+
+	if (IS_ERR(ld))
+		return PTR_ERR(ld);
+	tty->ldisc = ld;
+	return 0;
+}
+
+/**
+ * tty_ldisc_deinit	-	ldisc cleanup for new tty
+ * @tty: tty that was allocated recently
+ *
+ * The tty structure must not be completely set up (tty_ldisc_setup()) when
+ * this call is made.
+ */
+void tty_ldisc_deinit(struct tty_struct *tty)
+{
+	/* no ldisc_sem, tty is being destroyed */
+	if (tty->ldisc)
+		tty_ldisc_put(tty->ldisc);
+	tty->ldisc = NULL;
+}
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
new file mode 100644
index 000000000..3be428c16
--- /dev/null
+++ b/drivers/tty/tty_ldsem.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ldisc rw semaphore
+ *
+ * The ldisc semaphore is semantically a rw_semaphore but which enforces
+ * an alternate policy, namely:
+ *   1) Supports lock wait timeouts
+ *   2) Write waiter has priority
+ *   3) Downgrading is not supported
+ *
+ * Implementation notes:
+ *   1) Upper half of semaphore count is a wait count (differs from rwsem
+ *	in that rwsem normalizes the upper half to the wait bias)
+ *   2) Lacks overflow checking
+ *
+ * The generic counting was copied and modified from include/asm-generic/rwsem.h
+ * by Paul Mackerras <paulus@samba.org>.
+ *
+ * The scheduling policy was copied and modified from lib/rwsem.c
+ * Written by David Howells (dhowells@redhat.com).
+ *
+ * This implementation incorporates the write lock stealing work of
+ * Michel Lespinasse <walken@google.com>.
+ *
+ * Copyright (C) 2013 Peter Hurley <peter@hurleysoftware.com>
+ */
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/atomic.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+
+
+#if BITS_PER_LONG == 64
+# define LDSEM_ACTIVE_MASK	0xffffffffL
+#else
+# define LDSEM_ACTIVE_MASK	0x0000ffffL
+#endif
+
+#define LDSEM_UNLOCKED		0L
+#define LDSEM_ACTIVE_BIAS	1L
+#define LDSEM_WAIT_BIAS		(-LDSEM_ACTIVE_MASK-1)
+#define LDSEM_READ_BIAS		LDSEM_ACTIVE_BIAS
+#define LDSEM_WRITE_BIAS	(LDSEM_WAIT_BIAS + LDSEM_ACTIVE_BIAS)
+
+struct ldsem_waiter {
+	struct list_head list;
+	struct task_struct *task;
+};
+
+/*
+ * Initialize an ldsem:
+ */
+void __init_ldsem(struct ld_semaphore *sem, const char *name,
+		  struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held semaphore:
+	 */
+	debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+	lockdep_init_map(&sem->dep_map, name, key, 0);
+#endif
+	atomic_long_set(&sem->count, LDSEM_UNLOCKED);
+	sem->wait_readers = 0;
+	raw_spin_lock_init(&sem->wait_lock);
+	INIT_LIST_HEAD(&sem->read_wait);
+	INIT_LIST_HEAD(&sem->write_wait);
+}
+
+static void __ldsem_wake_readers(struct ld_semaphore *sem)
+{
+	struct ldsem_waiter *waiter, *next;
+	struct task_struct *tsk;
+	long adjust, count;
+
+	/*
+	 * Try to grant read locks to all readers on the read wait list.
+	 * Note the 'active part' of the count is incremented by
+	 * the number of readers before waking any processes up.
+	 */
+	adjust = sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS);
+	count = atomic_long_add_return(adjust, &sem->count);
+	do {
+		if (count > 0)
+			break;
+		if (atomic_long_try_cmpxchg(&sem->count, &count, count - adjust))
+			return;
+	} while (1);
+
+	list_for_each_entry_safe(waiter, next, &sem->read_wait, list) {
+		tsk = waiter->task;
+		smp_store_release(&waiter->task, NULL);
+		wake_up_process(tsk);
+		put_task_struct(tsk);
+	}
+	INIT_LIST_HEAD(&sem->read_wait);
+	sem->wait_readers = 0;
+}
+
+static inline int writer_trylock(struct ld_semaphore *sem)
+{
+	/*
+	 * Only wake this writer if the active part of the count can be
+	 * transitioned from 0 -> 1
+	 */
+	long count = atomic_long_add_return(LDSEM_ACTIVE_BIAS, &sem->count);
+	do {
+		if ((count & LDSEM_ACTIVE_MASK) == LDSEM_ACTIVE_BIAS)
+			return 1;
+		if (atomic_long_try_cmpxchg(&sem->count, &count, count - LDSEM_ACTIVE_BIAS))
+			return 0;
+	} while (1);
+}
+
+static void __ldsem_wake_writer(struct ld_semaphore *sem)
+{
+	struct ldsem_waiter *waiter;
+
+	waiter = list_entry(sem->write_wait.next, struct ldsem_waiter, list);
+	wake_up_process(waiter->task);
+}
+
+/*
+ * handle the lock release when processes blocked on it that can now run
+ * - if we come here from up_xxxx(), then:
+ *   - the 'active part' of count (&0x0000ffff) reached 0 (but may have changed)
+ *   - the 'waiting part' of count (&0xffff0000) is -ve (and will still be so)
+ * - the spinlock must be held by the caller
+ * - woken process blocks are discarded from the list after having task zeroed
+ */
+static void __ldsem_wake(struct ld_semaphore *sem)
+{
+	if (!list_empty(&sem->write_wait))
+		__ldsem_wake_writer(sem);
+	else if (!list_empty(&sem->read_wait))
+		__ldsem_wake_readers(sem);
+}
+
+static void ldsem_wake(struct ld_semaphore *sem)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&sem->wait_lock, flags);
+	__ldsem_wake(sem);
+	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
+}
+
+/*
+ * wait for the read lock to be granted
+ */
+static struct ld_semaphore __sched *
+down_read_failed(struct ld_semaphore *sem, long count, long timeout)
+{
+	struct ldsem_waiter waiter;
+	long adjust = -LDSEM_ACTIVE_BIAS + LDSEM_WAIT_BIAS;
+
+	/* set up my own style of waitqueue */
+	raw_spin_lock_irq(&sem->wait_lock);
+
+	/*
+	 * Try to reverse the lock attempt but if the count has changed
+	 * so that reversing fails, check if there are no waiters,
+	 * and early-out if not
+	 */
+	do {
+		if (atomic_long_try_cmpxchg(&sem->count, &count, count + adjust)) {
+			count += adjust;
+			break;
+		}
+		if (count > 0) {
+			raw_spin_unlock_irq(&sem->wait_lock);
+			return sem;
+		}
+	} while (1);
+
+	list_add_tail(&waiter.list, &sem->read_wait);
+	sem->wait_readers++;
+
+	waiter.task = current;
+	get_task_struct(current);
+
+	/* if there are no active locks, wake the new lock owner(s) */
+	if ((count & LDSEM_ACTIVE_MASK) == 0)
+		__ldsem_wake(sem);
+
+	raw_spin_unlock_irq(&sem->wait_lock);
+
+	/* wait to be given the lock */
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+
+		if (!smp_load_acquire(&waiter.task))
+			break;
+		if (!timeout)
+			break;
+		timeout = schedule_timeout(timeout);
+	}
+
+	__set_current_state(TASK_RUNNING);
+
+	if (!timeout) {
+		/*
+		 * Lock timed out but check if this task was just
+		 * granted lock ownership - if so, pretend there
+		 * was no timeout; otherwise, cleanup lock wait.
+		 */
+		raw_spin_lock_irq(&sem->wait_lock);
+		if (waiter.task) {
+			atomic_long_add_return(-LDSEM_WAIT_BIAS, &sem->count);
+			sem->wait_readers--;
+			list_del(&waiter.list);
+			raw_spin_unlock_irq(&sem->wait_lock);
+			put_task_struct(waiter.task);
+			return NULL;
+		}
+		raw_spin_unlock_irq(&sem->wait_lock);
+	}
+
+	return sem;
+}
+
+/*
+ * wait for the write lock to be granted
+ */
+static struct ld_semaphore __sched *
+down_write_failed(struct ld_semaphore *sem, long count, long timeout)
+{
+	struct ldsem_waiter waiter;
+	long adjust = -LDSEM_ACTIVE_BIAS;
+	int locked = 0;
+
+	/* set up my own style of waitqueue */
+	raw_spin_lock_irq(&sem->wait_lock);
+
+	/*
+	 * Try to reverse the lock attempt but if the count has changed
+	 * so that reversing fails, check if the lock is now owned,
+	 * and early-out if so.
+	 */
+	do {
+		if (atomic_long_try_cmpxchg(&sem->count, &count, count + adjust))
+			break;
+		if ((count & LDSEM_ACTIVE_MASK) == LDSEM_ACTIVE_BIAS) {
+			raw_spin_unlock_irq(&sem->wait_lock);
+			return sem;
+		}
+	} while (1);
+
+	list_add_tail(&waiter.list, &sem->write_wait);
+
+	waiter.task = current;
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	for (;;) {
+		if (!timeout)
+			break;
+		raw_spin_unlock_irq(&sem->wait_lock);
+		timeout = schedule_timeout(timeout);
+		raw_spin_lock_irq(&sem->wait_lock);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		locked = writer_trylock(sem);
+		if (locked)
+			break;
+	}
+
+	if (!locked)
+		atomic_long_add_return(-LDSEM_WAIT_BIAS, &sem->count);
+	list_del(&waiter.list);
+
+	/*
+	 * In case of timeout, wake up every reader who gave the right of way
+	 * to writer. Prevent separation readers into two groups:
+	 * one that helds semaphore and another that sleeps.
+	 * (in case of no contention with a writer)
+	 */
+	if (!locked && list_empty(&sem->write_wait))
+		__ldsem_wake_readers(sem);
+
+	raw_spin_unlock_irq(&sem->wait_lock);
+
+	__set_current_state(TASK_RUNNING);
+
+	/* lock wait may have timed out */
+	if (!locked)
+		return NULL;
+	return sem;
+}
+
+
+
+static int __ldsem_down_read_nested(struct ld_semaphore *sem,
+					   int subclass, long timeout)
+{
+	long count;
+
+	rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_);
+
+	count = atomic_long_add_return(LDSEM_READ_BIAS, &sem->count);
+	if (count <= 0) {
+		lock_contended(&sem->dep_map, _RET_IP_);
+		if (!down_read_failed(sem, count, timeout)) {
+			rwsem_release(&sem->dep_map, _RET_IP_);
+			return 0;
+		}
+	}
+	lock_acquired(&sem->dep_map, _RET_IP_);
+	return 1;
+}
+
+static int __ldsem_down_write_nested(struct ld_semaphore *sem,
+					    int subclass, long timeout)
+{
+	long count;
+
+	rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_);
+
+	count = atomic_long_add_return(LDSEM_WRITE_BIAS, &sem->count);
+	if ((count & LDSEM_ACTIVE_MASK) != LDSEM_ACTIVE_BIAS) {
+		lock_contended(&sem->dep_map, _RET_IP_);
+		if (!down_write_failed(sem, count, timeout)) {
+			rwsem_release(&sem->dep_map, _RET_IP_);
+			return 0;
+		}
+	}
+	lock_acquired(&sem->dep_map, _RET_IP_);
+	return 1;
+}
+
+
+/*
+ * lock for reading -- returns 1 if successful, 0 if timed out
+ */
+int __sched ldsem_down_read(struct ld_semaphore *sem, long timeout)
+{
+	might_sleep();
+	return __ldsem_down_read_nested(sem, 0, timeout);
+}
+
+/*
+ * trylock for reading -- returns 1 if successful, 0 if contention
+ */
+int ldsem_down_read_trylock(struct ld_semaphore *sem)
+{
+	long count = atomic_long_read(&sem->count);
+
+	while (count >= 0) {
+		if (atomic_long_try_cmpxchg(&sem->count, &count, count + LDSEM_READ_BIAS)) {
+			rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
+			lock_acquired(&sem->dep_map, _RET_IP_);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * lock for writing -- returns 1 if successful, 0 if timed out
+ */
+int __sched ldsem_down_write(struct ld_semaphore *sem, long timeout)
+{
+	might_sleep();
+	return __ldsem_down_write_nested(sem, 0, timeout);
+}
+
+/*
+ * trylock for writing -- returns 1 if successful, 0 if contention
+ */
+int ldsem_down_write_trylock(struct ld_semaphore *sem)
+{
+	long count = atomic_long_read(&sem->count);
+
+	while ((count & LDSEM_ACTIVE_MASK) == 0) {
+		if (atomic_long_try_cmpxchg(&sem->count, &count, count + LDSEM_WRITE_BIAS)) {
+			rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
+			lock_acquired(&sem->dep_map, _RET_IP_);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * release a read lock
+ */
+void ldsem_up_read(struct ld_semaphore *sem)
+{
+	long count;
+
+	rwsem_release(&sem->dep_map, _RET_IP_);
+
+	count = atomic_long_add_return(-LDSEM_READ_BIAS, &sem->count);
+	if (count < 0 && (count & LDSEM_ACTIVE_MASK) == 0)
+		ldsem_wake(sem);
+}
+
+/*
+ * release a write lock
+ */
+void ldsem_up_write(struct ld_semaphore *sem)
+{
+	long count;
+
+	rwsem_release(&sem->dep_map, _RET_IP_);
+
+	count = atomic_long_add_return(-LDSEM_WRITE_BIAS, &sem->count);
+	if (count < 0)
+		ldsem_wake(sem);
+}
+
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass, long timeout)
+{
+	might_sleep();
+	return __ldsem_down_read_nested(sem, subclass, timeout);
+}
+
+int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
+			    long timeout)
+{
+	might_sleep();
+	return __ldsem_down_write_nested(sem, subclass, timeout);
+}
+
+#endif
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
new file mode 100644
index 000000000..784e46a0a
--- /dev/null
+++ b/drivers/tty/tty_mutex.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+#include "tty.h"
+
+/* Legacy tty mutex glue */
+
+/*
+ * Getting the big tty mutex.
+ */
+
+void tty_lock(struct tty_struct *tty)
+{
+	tty_kref_get(tty);
+	mutex_lock(&tty->legacy_mutex);
+}
+EXPORT_SYMBOL(tty_lock);
+
+int tty_lock_interruptible(struct tty_struct *tty)
+{
+	int ret;
+
+	tty_kref_get(tty);
+	ret = mutex_lock_interruptible(&tty->legacy_mutex);
+	if (ret)
+		tty_kref_put(tty);
+	return ret;
+}
+
+void tty_unlock(struct tty_struct *tty)
+{
+	mutex_unlock(&tty->legacy_mutex);
+	tty_kref_put(tty);
+}
+EXPORT_SYMBOL(tty_unlock);
+
+void tty_lock_slave(struct tty_struct *tty)
+{
+	if (tty && tty != tty->link)
+		tty_lock(tty);
+}
+
+void tty_unlock_slave(struct tty_struct *tty)
+{
+	if (tty && tty != tty->link)
+		tty_unlock(tty);
+}
+
+void tty_set_lock_subclass(struct tty_struct *tty)
+{
+	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
+}
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
new file mode 100644
index 000000000..624d104bd
--- /dev/null
+++ b/drivers/tty/tty_port.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tty port functions
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/serdev.h>
+#include "tty.h"
+
+static size_t tty_port_default_receive_buf(struct tty_port *port, const u8 *p,
+					   const u8 *f, size_t count)
+{
+	struct tty_struct *tty;
+	struct tty_ldisc *ld;
+
+	tty = READ_ONCE(port->itty);
+	if (!tty)
+		return 0;
+
+	ld = tty_ldisc_ref(tty);
+	if (!ld)
+		return 0;
+
+	count = tty_ldisc_receive_buf(ld, p, f, count);
+
+	tty_ldisc_deref(ld);
+
+	return count;
+}
+
+static void tty_port_default_lookahead_buf(struct tty_port *port, const u8 *p,
+					   const u8 *f, size_t count)
+{
+	struct tty_struct *tty;
+	struct tty_ldisc *ld;
+
+	tty = READ_ONCE(port->itty);
+	if (!tty)
+		return;
+
+	ld = tty_ldisc_ref(tty);
+	if (!ld)
+		return;
+
+	if (ld->ops->lookahead_buf)
+		ld->ops->lookahead_buf(ld->tty, p, f, count);
+
+	tty_ldisc_deref(ld);
+}
+
+static void tty_port_default_wakeup(struct tty_port *port)
+{
+	struct tty_struct *tty = tty_port_tty_get(port);
+
+	if (tty) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
+	}
+}
+
+const struct tty_port_client_operations tty_port_default_client_ops = {
+	.receive_buf = tty_port_default_receive_buf,
+	.lookahead_buf = tty_port_default_lookahead_buf,
+	.write_wakeup = tty_port_default_wakeup,
+};
+EXPORT_SYMBOL_GPL(tty_port_default_client_ops);
+
+/**
+ * tty_port_init -- initialize tty_port
+ * @port: tty_port to initialize
+ *
+ * Initializes the state of struct tty_port. When a port was initialized using
+ * this function, one has to destroy the port by tty_port_destroy(). Either
+ * indirectly by using &tty_port refcounting (tty_port_put()) or directly if
+ * refcounting is not used.
+ */
+void tty_port_init(struct tty_port *port)
+{
+	memset(port, 0, sizeof(*port));
+	tty_buffer_init(port);
+	init_waitqueue_head(&port->open_wait);
+	init_waitqueue_head(&port->delta_msr_wait);
+	mutex_init(&port->mutex);
+	mutex_init(&port->buf_mutex);
+	spin_lock_init(&port->lock);
+	port->close_delay = (50 * HZ) / 100;
+	port->closing_wait = (3000 * HZ) / 100;
+	port->client_ops = &tty_port_default_client_ops;
+	kref_init(&port->kref);
+}
+EXPORT_SYMBOL(tty_port_init);
+
+/**
+ * tty_port_link_device - link tty and tty_port
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ *
+ * Provide the tty layer with a link from a tty (specified by @index) to a
+ * tty_port (@port). Use this only if neither tty_port_register_device() nor
+ * tty_port_install() is used in the driver. If used, this has to be called
+ * before tty_register_driver().
+ */
+void tty_port_link_device(struct tty_port *port,
+		struct tty_driver *driver, unsigned index)
+{
+	if (WARN_ON(index >= driver->num))
+		return;
+	driver->ports[index] = port;
+}
+EXPORT_SYMBOL_GPL(tty_port_link_device);
+
+/**
+ * tty_port_register_device - register tty device
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ * @device: parent if exists, otherwise NULL
+ *
+ * It is the same as tty_register_device() except the provided @port is linked
+ * to a concrete tty specified by @index. Use this or tty_port_install() (or
+ * both). Call tty_port_link_device() as a last resort.
+ */
+struct device *tty_port_register_device(struct tty_port *port,
+		struct tty_driver *driver, unsigned index,
+		struct device *device)
+{
+	return tty_port_register_device_attr(port, driver, index, device, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(tty_port_register_device);
+
+/**
+ * tty_port_register_device_attr - register tty device
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ * @device: parent if exists, otherwise NULL
+ * @drvdata: Driver data to be set to device.
+ * @attr_grp: Attribute group to be set on device.
+ *
+ * It is the same as tty_register_device_attr() except the provided @port is
+ * linked to a concrete tty specified by @index. Use this or tty_port_install()
+ * (or both). Call tty_port_link_device() as a last resort.
+ */
+struct device *tty_port_register_device_attr(struct tty_port *port,
+		struct tty_driver *driver, unsigned index,
+		struct device *device, void *drvdata,
+		const struct attribute_group **attr_grp)
+{
+	tty_port_link_device(port, driver, index);
+	return tty_register_device_attr(driver, index, device, drvdata,
+			attr_grp);
+}
+EXPORT_SYMBOL_GPL(tty_port_register_device_attr);
+
+/**
+ * tty_port_register_device_attr_serdev - register tty or serdev device
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ * @device: parent if exists, otherwise NULL
+ * @drvdata: driver data for the device
+ * @attr_grp: attribute group for the device
+ *
+ * Register a serdev or tty device depending on if the parent device has any
+ * defined serdev clients or not.
+ */
+struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
+		struct tty_driver *driver, unsigned index,
+		struct device *device, void *drvdata,
+		const struct attribute_group **attr_grp)
+{
+	struct device *dev;
+
+	tty_port_link_device(port, driver, index);
+
+	dev = serdev_tty_port_register(port, device, driver, index);
+	if (PTR_ERR(dev) != -ENODEV) {
+		/* Skip creating cdev if we registered a serdev device */
+		return dev;
+	}
+
+	return tty_register_device_attr(driver, index, device, drvdata,
+			attr_grp);
+}
+EXPORT_SYMBOL_GPL(tty_port_register_device_attr_serdev);
+
+/**
+ * tty_port_register_device_serdev - register tty or serdev device
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ * @device: parent if exists, otherwise NULL
+ *
+ * Register a serdev or tty device depending on if the parent device has any
+ * defined serdev clients or not.
+ */
+struct device *tty_port_register_device_serdev(struct tty_port *port,
+		struct tty_driver *driver, unsigned index,
+		struct device *device)
+{
+	return tty_port_register_device_attr_serdev(port, driver, index,
+			device, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(tty_port_register_device_serdev);
+
+/**
+ * tty_port_unregister_device - deregister a tty or serdev device
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ *
+ * If a tty or serdev device is registered with a call to
+ * tty_port_register_device_serdev() then this function must be called when
+ * the device is gone.
+ */
+void tty_port_unregister_device(struct tty_port *port,
+		struct tty_driver *driver, unsigned index)
+{
+	int ret;
+
+	ret = serdev_tty_port_unregister(port);
+	if (ret == 0)
+		return;
+
+	tty_unregister_device(driver, index);
+}
+EXPORT_SYMBOL_GPL(tty_port_unregister_device);
+
+int tty_port_alloc_xmit_buf(struct tty_port *port)
+{
+	/* We may sleep in get_zeroed_page() */
+	mutex_lock(&port->buf_mutex);
+	if (port->xmit_buf == NULL) {
+		port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
+		if (port->xmit_buf)
+			kfifo_init(&port->xmit_fifo, port->xmit_buf, PAGE_SIZE);
+	}
+	mutex_unlock(&port->buf_mutex);
+	if (port->xmit_buf == NULL)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
+
+void tty_port_free_xmit_buf(struct tty_port *port)
+{
+	mutex_lock(&port->buf_mutex);
+	free_page((unsigned long)port->xmit_buf);
+	port->xmit_buf = NULL;
+	INIT_KFIFO(port->xmit_fifo);
+	mutex_unlock(&port->buf_mutex);
+}
+EXPORT_SYMBOL(tty_port_free_xmit_buf);
+
+/**
+ * tty_port_destroy -- destroy inited port
+ * @port: tty port to be destroyed
+ *
+ * When a port was initialized using tty_port_init(), one has to destroy the
+ * port by this function. Either indirectly by using &tty_port refcounting
+ * (tty_port_put()) or directly if refcounting is not used.
+ */
+void tty_port_destroy(struct tty_port *port)
+{
+	tty_buffer_cancel_work(port);
+	tty_buffer_free_all(port);
+}
+EXPORT_SYMBOL(tty_port_destroy);
+
+static void tty_port_destructor(struct kref *kref)
+{
+	struct tty_port *port = container_of(kref, struct tty_port, kref);
+
+	/* check if last port ref was dropped before tty release */
+	if (WARN_ON(port->itty))
+		return;
+	free_page((unsigned long)port->xmit_buf);
+	tty_port_destroy(port);
+	if (port->ops && port->ops->destruct)
+		port->ops->destruct(port);
+	else
+		kfree(port);
+}
+
+/**
+ * tty_port_put -- drop a reference to tty_port
+ * @port: port to drop a reference of (can be NULL)
+ *
+ * The final put will destroy and free up the @port using
+ * @port->ops->destruct() hook, or using kfree() if not provided.
+ */
+void tty_port_put(struct tty_port *port)
+{
+	if (port)
+		kref_put(&port->kref, tty_port_destructor);
+}
+EXPORT_SYMBOL(tty_port_put);
+
+/**
+ * tty_port_tty_get	-	get a tty reference
+ * @port: tty port
+ *
+ * Return a refcount protected tty instance or %NULL if the port is not
+ * associated with a tty (eg due to close or hangup).
+ */
+struct tty_struct *tty_port_tty_get(struct tty_port *port)
+{
+	unsigned long flags;
+	struct tty_struct *tty;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tty = tty_kref_get(port->tty);
+	spin_unlock_irqrestore(&port->lock, flags);
+	return tty;
+}
+EXPORT_SYMBOL(tty_port_tty_get);
+
+/**
+ * tty_port_tty_set	-	set the tty of a port
+ * @port: tty port
+ * @tty: the tty
+ *
+ * Associate the port and tty pair. Manages any internal refcounts. Pass %NULL
+ * to deassociate a port.
+ */
+void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tty_kref_put(port->tty);
+	port->tty = tty_kref_get(tty);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_tty_set);
+
+/**
+ * tty_port_shutdown - internal helper to shutdown the device
+ * @port: tty port to be shut down
+ * @tty: the associated tty
+ *
+ * It is used by tty_port_hangup() and tty_port_close(). Its task is to
+ * shutdown the device if it was initialized (note consoles remain
+ * functioning). It lowers DTR/RTS (if @tty has HUPCL set) and invokes
+ * @port->ops->shutdown().
+ */
+static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty)
+{
+	mutex_lock(&port->mutex);
+	if (port->console)
+		goto out;
+
+	if (tty_port_initialized(port)) {
+		tty_port_set_initialized(port, false);
+		/*
+		 * Drop DTR/RTS if HUPCL is set. This causes any attached
+		 * modem to hang up the line.
+		 */
+		if (tty && C_HUPCL(tty))
+			tty_port_lower_dtr_rts(port);
+
+		if (port->ops->shutdown)
+			port->ops->shutdown(port);
+	}
+out:
+	mutex_unlock(&port->mutex);
+}
+
+/**
+ * tty_port_hangup		-	hangup helper
+ * @port: tty port
+ *
+ * Perform port level tty hangup flag and count changes. Drop the tty
+ * reference.
+ *
+ * Caller holds tty lock.
+ */
+void tty_port_hangup(struct tty_port *port)
+{
+	struct tty_struct *tty;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->count = 0;
+	tty = port->tty;
+	if (tty)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+	port->tty = NULL;
+	spin_unlock_irqrestore(&port->lock, flags);
+	tty_port_set_active(port, false);
+	tty_port_shutdown(port, tty);
+	tty_kref_put(tty);
+	wake_up_interruptible(&port->open_wait);
+	wake_up_interruptible(&port->delta_msr_wait);
+}
+EXPORT_SYMBOL(tty_port_hangup);
+
+/**
+ * tty_port_tty_hangup - helper to hang up a tty
+ * @port: tty port
+ * @check_clocal: hang only ttys with %CLOCAL unset?
+ */
+void tty_port_tty_hangup(struct tty_port *port, bool check_clocal)
+{
+	struct tty_struct *tty = tty_port_tty_get(port);
+
+	if (tty && (!check_clocal || !C_CLOCAL(tty)))
+		tty_hangup(tty);
+	tty_kref_put(tty);
+}
+EXPORT_SYMBOL_GPL(tty_port_tty_hangup);
+
+/**
+ * tty_port_tty_wakeup - helper to wake up a tty
+ * @port: tty port
+ */
+void tty_port_tty_wakeup(struct tty_port *port)
+{
+	port->client_ops->write_wakeup(port);
+}
+EXPORT_SYMBOL_GPL(tty_port_tty_wakeup);
+
+/**
+ * tty_port_carrier_raised	-	carrier raised check
+ * @port: tty port
+ *
+ * Wrapper for the carrier detect logic. For the moment this is used
+ * to hide some internal details. This will eventually become entirely
+ * internal to the tty port.
+ */
+bool tty_port_carrier_raised(struct tty_port *port)
+{
+	if (port->ops->carrier_raised == NULL)
+		return true;
+	return port->ops->carrier_raised(port);
+}
+EXPORT_SYMBOL(tty_port_carrier_raised);
+
+/**
+ * tty_port_raise_dtr_rts	-	Raise DTR/RTS
+ * @port: tty port
+ *
+ * Wrapper for the DTR/RTS raise logic. For the moment this is used to hide
+ * some internal details. This will eventually become entirely internal to the
+ * tty port.
+ */
+void tty_port_raise_dtr_rts(struct tty_port *port)
+{
+	if (port->ops->dtr_rts)
+		port->ops->dtr_rts(port, true);
+}
+EXPORT_SYMBOL(tty_port_raise_dtr_rts);
+
+/**
+ * tty_port_lower_dtr_rts	-	Lower DTR/RTS
+ * @port: tty port
+ *
+ * Wrapper for the DTR/RTS raise logic. For the moment this is used to hide
+ * some internal details. This will eventually become entirely internal to the
+ * tty port.
+ */
+void tty_port_lower_dtr_rts(struct tty_port *port)
+{
+	if (port->ops->dtr_rts)
+		port->ops->dtr_rts(port, false);
+}
+EXPORT_SYMBOL(tty_port_lower_dtr_rts);
+
+/**
+ * tty_port_block_til_ready	-	Waiting logic for tty open
+ * @port: the tty port being opened
+ * @tty: the tty device being bound
+ * @filp: the file pointer of the opener or %NULL
+ *
+ * Implement the core POSIX/SuS tty behaviour when opening a tty device.
+ * Handles:
+ *
+ *	- hangup (both before and during)
+ *	- non blocking open
+ *	- rts/dtr/dcd
+ *	- signals
+ *	- port flags and counts
+ *
+ * The passed @port must implement the @port->ops->carrier_raised method if it
+ * can do carrier detect and the @port->ops->dtr_rts method if it supports
+ * software management of these lines. Note that the dtr/rts raise is done each
+ * iteration as a hangup may have previously dropped them while we wait.
+ *
+ * Caller holds tty lock.
+ *
+ * Note: May drop and reacquire tty lock when blocking, so @tty and @port may
+ * have changed state (eg., may have been hung up).
+ */
+int tty_port_block_til_ready(struct tty_port *port,
+				struct tty_struct *tty, struct file *filp)
+{
+	int do_clocal = 0, retval;
+	unsigned long flags;
+	DEFINE_WAIT(wait);
+
+	/* if non-blocking mode is set we can pass directly to open unless
+	 * the port has just hung up or is in another error state.
+	 */
+	if (tty_io_error(tty)) {
+		tty_port_set_active(port, true);
+		return 0;
+	}
+	if (filp == NULL || (filp->f_flags & O_NONBLOCK)) {
+		/* Indicate we are open */
+		if (C_BAUD(tty))
+			tty_port_raise_dtr_rts(port);
+		tty_port_set_active(port, true);
+		return 0;
+	}
+
+	if (C_CLOCAL(tty))
+		do_clocal = 1;
+
+	/* Block waiting until we can proceed. We may need to wait for the
+	 * carrier, but we must also wait for any close that is in progress
+	 * before the next open may complete.
+	 */
+
+	retval = 0;
+
+	/* The port lock protects the port counts */
+	spin_lock_irqsave(&port->lock, flags);
+	port->count--;
+	port->blocked_open++;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	while (1) {
+		/* Indicate we are open */
+		if (C_BAUD(tty) && tty_port_initialized(port))
+			tty_port_raise_dtr_rts(port);
+
+		prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
+		/* Check for a hangup or uninitialised port.
+		 * Return accordingly.
+		 */
+		if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
+			if (port->flags & ASYNC_HUP_NOTIFY)
+				retval = -EAGAIN;
+			else
+				retval = -ERESTARTSYS;
+			break;
+		}
+		/*
+		 * Probe the carrier. For devices with no carrier detect
+		 * tty_port_carrier_raised will always return true.
+		 * Never ask drivers if CLOCAL is set, this causes troubles
+		 * on some hardware.
+		 */
+		if (do_clocal || tty_port_carrier_raised(port))
+			break;
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+		tty_unlock(tty);
+		schedule();
+		tty_lock(tty);
+	}
+	finish_wait(&port->open_wait, &wait);
+
+	/* Update counts. A parallel hangup will have set count to zero and
+	 * we must not mess that up further.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+	if (!tty_hung_up_p(filp))
+		port->count++;
+	port->blocked_open--;
+	spin_unlock_irqrestore(&port->lock, flags);
+	if (retval == 0)
+		tty_port_set_active(port, true);
+	return retval;
+}
+EXPORT_SYMBOL(tty_port_block_til_ready);
+
+static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty)
+{
+	unsigned int bps = tty_get_baud_rate(tty);
+	long timeout;
+
+	if (bps > 1200) {
+		timeout = (HZ * 10 * port->drain_delay) / bps;
+		timeout = max_t(long, timeout, HZ / 10);
+	} else {
+		timeout = 2 * HZ;
+	}
+	schedule_timeout_interruptible(timeout);
+}
+
+/**
+ * tty_port_close_start - helper for tty->ops->close, part 1/2
+ * @port: tty_port of the device
+ * @tty: tty being closed
+ * @filp: passed file pointer
+ *
+ * Decrements and checks open count. Flushes the port if this is the last
+ * close. That means, dropping the data from the outpu buffer on the device and
+ * waiting for sending logic to finish. The rest of close handling is performed
+ * in tty_port_close_end().
+ *
+ * Locking: Caller holds tty lock.
+ *
+ * Return: 1 if this is the last close, otherwise 0
+ */
+int tty_port_close_start(struct tty_port *port,
+				struct tty_struct *tty, struct file *filp)
+{
+	unsigned long flags;
+
+	if (tty_hung_up_p(filp))
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (tty->count == 1 && port->count != 1) {
+		tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__,
+			 port->count);
+		port->count = 1;
+	}
+	if (--port->count < 0) {
+		tty_warn(tty, "%s: bad port count (%d)\n", __func__,
+			 port->count);
+		port->count = 0;
+	}
+
+	if (port->count) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		return 0;
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	tty->closing = 1;
+
+	if (tty_port_initialized(port)) {
+		/* Don't block on a stalled port, just pull the chain */
+		if (tty->flow.tco_stopped)
+			tty_driver_flush_buffer(tty);
+		if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+			tty_wait_until_sent(tty, port->closing_wait);
+		if (port->drain_delay)
+			tty_port_drain_delay(port, tty);
+	}
+	/* Flush the ldisc buffering */
+	tty_ldisc_flush(tty);
+
+	/* Report to caller this is the last port reference */
+	return 1;
+}
+EXPORT_SYMBOL(tty_port_close_start);
+
+/**
+ * tty_port_close_end - helper for tty->ops->close, part 2/2
+ * @port: tty_port of the device
+ * @tty: tty being closed
+ *
+ * This is a continuation of the first part: tty_port_close_start(). This
+ * should be called after turning off the device. It flushes the data from the
+ * line discipline and delays the close by @port->close_delay.
+ *
+ * Locking: Caller holds tty lock.
+ */
+void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	tty_ldisc_flush(tty);
+	tty->closing = 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (port->blocked_open) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		if (port->close_delay)
+			msleep_interruptible(jiffies_to_msecs(port->close_delay));
+		spin_lock_irqsave(&port->lock, flags);
+		wake_up_interruptible(&port->open_wait);
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+	tty_port_set_active(port, false);
+}
+EXPORT_SYMBOL(tty_port_close_end);
+
+/**
+ * tty_port_close - generic tty->ops->close handler
+ * @port: tty_port of the device
+ * @tty: tty being closed
+ * @filp: passed file pointer
+ *
+ * It is a generic helper to be used in driver's @tty->ops->close. It wraps a
+ * sequence of tty_port_close_start(), tty_port_shutdown(), and
+ * tty_port_close_end(). The latter two are called only if this is the last
+ * close. See the respective functions for the details.
+ *
+ * Locking: Caller holds tty lock
+ */
+void tty_port_close(struct tty_port *port, struct tty_struct *tty,
+							struct file *filp)
+{
+	if (tty_port_close_start(port, tty, filp) == 0)
+		return;
+	tty_port_shutdown(port, tty);
+	if (!port->console)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+	tty_port_close_end(port, tty);
+	tty_port_tty_set(port, NULL);
+}
+EXPORT_SYMBOL(tty_port_close);
+
+/**
+ * tty_port_install - generic tty->ops->install handler
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @tty: tty to be installed
+ *
+ * It is the same as tty_standard_install() except the provided @port is linked
+ * to a concrete tty specified by @tty. Use this or tty_port_register_device()
+ * (or both). Call tty_port_link_device() as a last resort.
+ */
+int tty_port_install(struct tty_port *port, struct tty_driver *driver,
+		struct tty_struct *tty)
+{
+	tty->port = port;
+	return tty_standard_install(driver, tty);
+}
+EXPORT_SYMBOL_GPL(tty_port_install);
+
+/**
+ * tty_port_open - generic tty->ops->open handler
+ * @port: tty_port of the device
+ * @tty: tty to be opened
+ * @filp: passed file pointer
+ *
+ * It is a generic helper to be used in driver's @tty->ops->open. It activates
+ * the devices using @port->ops->activate if not active already. And waits for
+ * the device to be ready using tty_port_block_til_ready() (e.g.  raises
+ * DTR/CTS and waits for carrier).
+ *
+ * Note that @port->ops->shutdown is not called when @port->ops->activate
+ * returns an error (on the contrary, @tty->ops->close is).
+ *
+ * Locking: Caller holds tty lock.
+ *
+ * Note: may drop and reacquire tty lock (in tty_port_block_til_ready()) so
+ * @tty and @port may have changed state (eg., may be hung up now).
+ */
+int tty_port_open(struct tty_port *port, struct tty_struct *tty,
+							struct file *filp)
+{
+	spin_lock_irq(&port->lock);
+	++port->count;
+	spin_unlock_irq(&port->lock);
+	tty_port_tty_set(port, tty);
+
+	/*
+	 * Do the device-specific open only if the hardware isn't
+	 * already initialized. Serialize open and shutdown using the
+	 * port mutex.
+	 */
+
+	mutex_lock(&port->mutex);
+
+	if (!tty_port_initialized(port)) {
+		clear_bit(TTY_IO_ERROR, &tty->flags);
+		if (port->ops->activate) {
+			int retval = port->ops->activate(port, tty);
+
+			if (retval) {
+				mutex_unlock(&port->mutex);
+				return retval;
+			}
+		}
+		tty_port_set_initialized(port, true);
+	}
+	mutex_unlock(&port->mutex);
+	return tty_port_block_til_ready(port, tty, filp);
+}
+EXPORT_SYMBOL(tty_port_open);
diff --git a/drivers/tty/ttynull.c b/drivers/tty/ttynull.c
new file mode 100644
index 000000000..e4c427399
--- /dev/null
+++ b/drivers/tty/ttynull.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Axis Communications AB
+ *
+ * Based on ttyprintk.c:
+ *  Copyright (C) 2010 Samo Pogacnik
+ */
+
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+
+static const struct tty_port_operations ttynull_port_ops;
+static struct tty_driver *ttynull_driver;
+static struct tty_port ttynull_port;
+
+static int ttynull_open(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_open(&ttynull_port, tty, filp);
+}
+
+static void ttynull_close(struct tty_struct *tty, struct file *filp)
+{
+	tty_port_close(&ttynull_port, tty, filp);
+}
+
+static void ttynull_hangup(struct tty_struct *tty)
+{
+	tty_port_hangup(&ttynull_port);
+}
+
+static ssize_t ttynull_write(struct tty_struct *tty, const u8 *buf,
+			     size_t count)
+{
+	return count;
+}
+
+static unsigned int ttynull_write_room(struct tty_struct *tty)
+{
+	return 65536;
+}
+
+static const struct tty_operations ttynull_ops = {
+	.open = ttynull_open,
+	.close = ttynull_close,
+	.hangup = ttynull_hangup,
+	.write = ttynull_write,
+	.write_room = ttynull_write_room,
+};
+
+static struct tty_driver *ttynull_device(struct console *c, int *index)
+{
+	*index = 0;
+	return ttynull_driver;
+}
+
+static struct console ttynull_console = {
+	.name = "ttynull",
+	.device = ttynull_device,
+};
+
+static int __init ttynull_init(void)
+{
+	struct tty_driver *driver;
+	int ret;
+
+	driver = tty_alloc_driver(1,
+		TTY_DRIVER_RESET_TERMIOS |
+		TTY_DRIVER_REAL_RAW |
+		TTY_DRIVER_UNNUMBERED_NODE);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
+
+	tty_port_init(&ttynull_port);
+	ttynull_port.ops = &ttynull_port_ops;
+
+	driver->driver_name = "ttynull";
+	driver->name = "ttynull";
+	driver->type = TTY_DRIVER_TYPE_CONSOLE;
+	driver->init_termios = tty_std_termios;
+	driver->init_termios.c_oflag = OPOST | OCRNL | ONOCR | ONLRET;
+	tty_set_operations(driver, &ttynull_ops);
+	tty_port_link_device(&ttynull_port, driver, 0);
+
+	ret = tty_register_driver(driver);
+	if (ret < 0) {
+		tty_driver_kref_put(driver);
+		tty_port_destroy(&ttynull_port);
+		return ret;
+	}
+
+	ttynull_driver = driver;
+	register_console(&ttynull_console);
+
+	return 0;
+}
+
+static void __exit ttynull_exit(void)
+{
+	unregister_console(&ttynull_console);
+	tty_unregister_driver(ttynull_driver);
+	tty_driver_kref_put(ttynull_driver);
+	tty_port_destroy(&ttynull_port);
+}
+
+module_init(ttynull_init);
+module_exit(ttynull_exit);
+
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c
new file mode 100644
index 000000000..5b625f202
--- /dev/null
+++ b/drivers/tty/vcc.c
@@ -0,0 +1,1091 @@
+// SPDX-License-Identifier: GPL-2.0
+/* vcc.c: sun4v virtual channel concentrator
+ *
+ * Copyright (C) 2017 Oracle. All rights reserved.
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/termios_internal.h>
+#include <asm/vio.h>
+#include <asm/ldc.h>
+
+MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.1");
+
+struct vcc_port {
+	struct vio_driver_state vio;
+
+	spinlock_t lock;
+	char *domain;
+	struct tty_struct *tty;	/* only populated while dev is open */
+	unsigned long index;	/* index into the vcc_table */
+
+	u64 refcnt;
+	bool excl_locked;
+
+	bool removed;
+
+	/* This buffer is required to support the tty write_room interface
+	 * and guarantee that any characters that the driver accepts will
+	 * be eventually sent, either immediately or later.
+	 */
+	size_t chars_in_buffer;
+	struct vio_vcc buffer;
+
+	struct timer_list rx_timer;
+	struct timer_list tx_timer;
+};
+
+/* Microseconds that thread will delay waiting for a vcc port ref */
+#define VCC_REF_DELAY		100
+
+#define VCC_MAX_PORTS		1024
+#define VCC_MINOR_START		0	/* must be zero */
+#define VCC_BUFF_LEN		VIO_VCC_MTU_SIZE
+
+#define VCC_CTL_BREAK		-1
+#define VCC_CTL_HUP		-2
+
+static struct tty_driver *vcc_tty_driver;
+
+static struct vcc_port *vcc_table[VCC_MAX_PORTS];
+static DEFINE_SPINLOCK(vcc_table_lock);
+
+static unsigned int vcc_dbg;
+static unsigned int vcc_dbg_ldc;
+static unsigned int vcc_dbg_vio;
+
+module_param(vcc_dbg, uint, 0664);
+module_param(vcc_dbg_ldc, uint, 0664);
+module_param(vcc_dbg_vio, uint, 0664);
+
+#define VCC_DBG_DRV	0x1
+#define VCC_DBG_LDC	0x2
+#define VCC_DBG_PKT	0x4
+
+#define vccdbg(f, a...)						\
+	do {							\
+		if (vcc_dbg & VCC_DBG_DRV)			\
+			pr_info(f, ## a);			\
+	} while (0)						\
+
+#define vccdbgl(l)						\
+	do {							\
+		if (vcc_dbg & VCC_DBG_LDC)			\
+			ldc_print(l);				\
+	} while (0)						\
+
+#define vccdbgp(pkt)						\
+	do {							\
+		if (vcc_dbg & VCC_DBG_PKT) {			\
+			int i;					\
+			for (i = 0; i < pkt.tag.stype; i++)	\
+				pr_info("[%c]", pkt.data[i]);	\
+		}						\
+	} while (0)						\
+
+/* Note: Be careful when adding flags to this line discipline.  Don't
+ * add anything that will cause echoing or we'll go into recursive
+ * loop echoing chars back and forth with the console drivers.
+ */
+static const struct ktermios vcc_tty_termios = {
+	.c_iflag = IGNBRK | IGNPAR,
+	.c_oflag = OPOST,
+	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
+	.c_cc = INIT_C_CC,
+	.c_ispeed = 38400,
+	.c_ospeed = 38400
+};
+
+/**
+ * vcc_table_add() - Add VCC port to the VCC table
+ * @port: pointer to the VCC port
+ *
+ * Return: index of the port in the VCC table on success,
+ *	   -1 on failure
+ */
+static int vcc_table_add(struct vcc_port *port)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&vcc_table_lock, flags);
+	for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) {
+		if (!vcc_table[i]) {
+			vcc_table[i] = port;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&vcc_table_lock, flags);
+
+	if (i < VCC_MAX_PORTS)
+		return i;
+	else
+		return -1;
+}
+
+/**
+ * vcc_table_remove() - Removes a VCC port from the VCC table
+ * @index: Index into the VCC table
+ */
+static void vcc_table_remove(unsigned long index)
+{
+	unsigned long flags;
+
+	if (WARN_ON(index >= VCC_MAX_PORTS))
+		return;
+
+	spin_lock_irqsave(&vcc_table_lock, flags);
+	vcc_table[index] = NULL;
+	spin_unlock_irqrestore(&vcc_table_lock, flags);
+}
+
+/**
+ * vcc_get() - Gets a reference to VCC port
+ * @index: Index into the VCC table
+ * @excl: Indicates if an exclusive access is requested
+ *
+ * Return: reference to the VCC port, if found
+ *	   NULL, if port not found
+ */
+static struct vcc_port *vcc_get(unsigned long index, bool excl)
+{
+	struct vcc_port *port;
+	unsigned long flags;
+
+try_again:
+	spin_lock_irqsave(&vcc_table_lock, flags);
+
+	port = vcc_table[index];
+	if (!port) {
+		spin_unlock_irqrestore(&vcc_table_lock, flags);
+		return NULL;
+	}
+
+	if (!excl) {
+		if (port->excl_locked) {
+			spin_unlock_irqrestore(&vcc_table_lock, flags);
+			udelay(VCC_REF_DELAY);
+			goto try_again;
+		}
+		port->refcnt++;
+		spin_unlock_irqrestore(&vcc_table_lock, flags);
+		return port;
+	}
+
+	if (port->refcnt) {
+		spin_unlock_irqrestore(&vcc_table_lock, flags);
+		/* Threads wanting exclusive access will wait half the time,
+		 * probably giving them higher priority in the case of
+		 * multiple waiters.
+		 */
+		udelay(VCC_REF_DELAY/2);
+		goto try_again;
+	}
+
+	port->refcnt++;
+	port->excl_locked = true;
+	spin_unlock_irqrestore(&vcc_table_lock, flags);
+
+	return port;
+}
+
+/**
+ * vcc_put() - Returns a reference to VCC port
+ * @port: pointer to VCC port
+ * @excl: Indicates if the returned reference is an exclusive reference
+ *
+ * Note: It's the caller's responsibility to ensure the correct value
+ *	 for the excl flag
+ */
+static void vcc_put(struct vcc_port *port, bool excl)
+{
+	unsigned long flags;
+
+	if (!port)
+		return;
+
+	spin_lock_irqsave(&vcc_table_lock, flags);
+
+	/* check if caller attempted to put with the wrong flags */
+	if (WARN_ON((excl && !port->excl_locked) ||
+		    (!excl && port->excl_locked)))
+		goto done;
+
+	port->refcnt--;
+
+	if (excl)
+		port->excl_locked = false;
+
+done:
+	spin_unlock_irqrestore(&vcc_table_lock, flags);
+}
+
+/**
+ * vcc_get_ne() - Get a non-exclusive reference to VCC port
+ * @index: Index into the VCC table
+ *
+ * Gets a non-exclusive reference to VCC port, if it's not removed
+ *
+ * Return: pointer to the VCC port, if found
+ *	   NULL, if port not found
+ */
+static struct vcc_port *vcc_get_ne(unsigned long index)
+{
+	struct vcc_port *port;
+
+	port = vcc_get(index, false);
+
+	if (port && port->removed) {
+		vcc_put(port, false);
+		return NULL;
+	}
+
+	return port;
+}
+
+static void vcc_kick_rx(struct vcc_port *port)
+{
+	struct vio_driver_state *vio = &port->vio;
+
+	assert_spin_locked(&port->lock);
+
+	if (!timer_pending(&port->rx_timer) && !port->removed) {
+		disable_irq_nosync(vio->vdev->rx_irq);
+		port->rx_timer.expires = (jiffies + 1);
+		add_timer(&port->rx_timer);
+	}
+}
+
+static void vcc_kick_tx(struct vcc_port *port)
+{
+	assert_spin_locked(&port->lock);
+
+	if (!timer_pending(&port->tx_timer) && !port->removed) {
+		port->tx_timer.expires = (jiffies + 1);
+		add_timer(&port->tx_timer);
+	}
+}
+
+static int vcc_rx_check(struct tty_struct *tty, int size)
+{
+	if (WARN_ON(!tty || !tty->port))
+		return 1;
+
+	/* tty_buffer_request_room won't sleep because it uses
+	 * GFP_ATOMIC flag to allocate buffer
+	 */
+	if (test_bit(TTY_THROTTLED, &tty->flags) ||
+	    (tty_buffer_request_room(tty->port, VCC_BUFF_LEN) < VCC_BUFF_LEN))
+		return 0;
+
+	return 1;
+}
+
+static int vcc_rx(struct tty_struct *tty, char *buf, int size)
+{
+	int len = 0;
+
+	if (WARN_ON(!tty || !tty->port))
+		return len;
+
+	len = tty_insert_flip_string(tty->port, buf, size);
+	if (len)
+		tty_flip_buffer_push(tty->port);
+
+	return len;
+}
+
+static int vcc_ldc_read(struct vcc_port *port)
+{
+	struct vio_driver_state *vio = &port->vio;
+	struct tty_struct *tty;
+	struct vio_vcc pkt;
+	int rv = 0;
+
+	tty = port->tty;
+	if (!tty) {
+		rv = ldc_rx_reset(vio->lp);
+		vccdbg("VCC: reset rx q: rv=%d\n", rv);
+		goto done;
+	}
+
+	/* Read as long as LDC has incoming data. */
+	while (1) {
+		if (!vcc_rx_check(tty, VIO_VCC_MTU_SIZE)) {
+			vcc_kick_rx(port);
+			break;
+		}
+
+		vccdbgl(vio->lp);
+
+		rv = ldc_read(vio->lp, &pkt, sizeof(pkt));
+		if (rv <= 0)
+			break;
+
+		vccdbg("VCC: ldc_read()=%d\n", rv);
+		vccdbg("TAG [%02x:%02x:%04x:%08x]\n",
+		       pkt.tag.type, pkt.tag.stype,
+		       pkt.tag.stype_env, pkt.tag.sid);
+
+		if (pkt.tag.type == VIO_TYPE_DATA) {
+			vccdbgp(pkt);
+			/* vcc_rx_check ensures memory availability */
+			vcc_rx(tty, pkt.data, pkt.tag.stype);
+		} else {
+			pr_err("VCC: unknown msg [%02x:%02x:%04x:%08x]\n",
+			       pkt.tag.type, pkt.tag.stype,
+			       pkt.tag.stype_env, pkt.tag.sid);
+			rv = -ECONNRESET;
+			break;
+		}
+
+		WARN_ON(rv != LDC_PACKET_SIZE);
+	}
+
+done:
+	return rv;
+}
+
+static void vcc_rx_timer(struct timer_list *t)
+{
+	struct vcc_port *port = from_timer(port, t, rx_timer);
+	struct vio_driver_state *vio;
+	unsigned long flags;
+	int rv;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->rx_timer.expires = 0;
+
+	vio = &port->vio;
+
+	enable_irq(vio->vdev->rx_irq);
+
+	if (!port->tty || port->removed)
+		goto done;
+
+	rv = vcc_ldc_read(port);
+	if (rv == -ECONNRESET)
+		vio_conn_reset(vio);
+
+done:
+	spin_unlock_irqrestore(&port->lock, flags);
+	vcc_put(port, false);
+}
+
+static void vcc_tx_timer(struct timer_list *t)
+{
+	struct vcc_port *port = from_timer(port, t, tx_timer);
+	struct vio_vcc *pkt;
+	unsigned long flags;
+	size_t tosend = 0;
+	int rv;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->tx_timer.expires = 0;
+
+	if (!port->tty || port->removed)
+		goto done;
+
+	tosend = min(VCC_BUFF_LEN, port->chars_in_buffer);
+	if (!tosend)
+		goto done;
+
+	pkt = &port->buffer;
+	pkt->tag.type = VIO_TYPE_DATA;
+	pkt->tag.stype = tosend;
+	vccdbgl(port->vio.lp);
+
+	rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend));
+	WARN_ON(!rv);
+
+	if (rv < 0) {
+		vccdbg("VCC: ldc_write()=%d\n", rv);
+		vcc_kick_tx(port);
+	} else {
+		struct tty_struct *tty = port->tty;
+
+		port->chars_in_buffer = 0;
+		if (tty)
+			tty_wakeup(tty);
+	}
+
+done:
+	spin_unlock_irqrestore(&port->lock, flags);
+	vcc_put(port, false);
+}
+
+/**
+ * vcc_event() - LDC event processing engine
+ * @arg: VCC private data
+ * @event: LDC event
+ *
+ * Handles LDC events for VCC
+ */
+static void vcc_event(void *arg, int event)
+{
+	struct vio_driver_state *vio;
+	struct vcc_port *port;
+	unsigned long flags;
+	int rv;
+
+	port = arg;
+	vio = &port->vio;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	switch (event) {
+	case LDC_EVENT_RESET:
+	case LDC_EVENT_UP:
+		vio_link_state_change(vio, event);
+		break;
+
+	case LDC_EVENT_DATA_READY:
+		rv = vcc_ldc_read(port);
+		if (rv == -ECONNRESET)
+			vio_conn_reset(vio);
+		break;
+
+	default:
+		pr_err("VCC: unexpected LDC event(%d)\n", event);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static struct ldc_channel_config vcc_ldc_cfg = {
+	.event		= vcc_event,
+	.mtu		= VIO_VCC_MTU_SIZE,
+	.mode		= LDC_MODE_RAW,
+	.debug		= 0,
+};
+
+/* Ordered from largest major to lowest */
+static struct vio_version vcc_versions[] = {
+	{ .major = 1, .minor = 0 },
+};
+
+static struct tty_port_operations vcc_port_ops = { 0 };
+
+static ssize_t domain_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct vcc_port *port;
+	int rv;
+
+	port = dev_get_drvdata(dev);
+	if (!port)
+		return -ENODEV;
+
+	rv = scnprintf(buf, PAGE_SIZE, "%s\n", port->domain);
+
+	return rv;
+}
+
+static int vcc_send_ctl(struct vcc_port *port, int ctl)
+{
+	struct vio_vcc pkt;
+	int rv;
+
+	pkt.tag.type = VIO_TYPE_CTRL;
+	pkt.tag.sid = ctl;
+	pkt.tag.stype = 0;
+
+	rv = ldc_write(port->vio.lp, &pkt, sizeof(pkt.tag));
+	WARN_ON(!rv);
+	vccdbg("VCC: ldc_write(%ld)=%d\n", sizeof(pkt.tag), rv);
+
+	return rv;
+}
+
+static ssize_t break_store(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct vcc_port *port;
+	unsigned long flags;
+	int rv = count;
+	int brk;
+
+	port = dev_get_drvdata(dev);
+	if (!port)
+		return -ENODEV;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (sscanf(buf, "%ud", &brk) != 1 || brk != 1)
+		rv = -EINVAL;
+	else if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0)
+		vcc_kick_tx(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return rv;
+}
+
+static DEVICE_ATTR_ADMIN_RO(domain);
+static DEVICE_ATTR_WO(break);
+
+static struct attribute *vcc_sysfs_entries[] = {
+	&dev_attr_domain.attr,
+	&dev_attr_break.attr,
+	NULL
+};
+
+static struct attribute_group vcc_attribute_group = {
+	.name = NULL,
+	.attrs = vcc_sysfs_entries,
+};
+
+/**
+ * vcc_probe() - Initialize VCC port
+ * @vdev: Pointer to VIO device of the new VCC port
+ * @id: VIO device ID
+ *
+ * Initializes a VCC port to receive serial console data from
+ * the guest domain. Sets up a TTY end point on the control
+ * domain. Sets up VIO/LDC link between the guest & control
+ * domain endpoints.
+ *
+ * Return: status of the probe
+ */
+static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
+{
+	struct mdesc_handle *hp;
+	struct vcc_port *port;
+	struct device *dev;
+	const char *domain;
+	char *name;
+	u64 node;
+	int rv;
+
+	vccdbg("VCC: name=%s\n", dev_name(&vdev->dev));
+
+	if (!vcc_tty_driver) {
+		pr_err("VCC: TTY driver not registered\n");
+		return -ENODEV;
+	}
+
+	port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL);
+	if (!name) {
+		rv = -ENOMEM;
+		goto free_port;
+	}
+
+	rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions,
+			     ARRAY_SIZE(vcc_versions), NULL, name);
+	if (rv)
+		goto free_name;
+
+	port->vio.debug = vcc_dbg_vio;
+	vcc_ldc_cfg.debug = vcc_dbg_ldc;
+
+	rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port);
+	if (rv)
+		goto free_name;
+
+	spin_lock_init(&port->lock);
+
+	port->index = vcc_table_add(port);
+	if (port->index == -1) {
+		pr_err("VCC: no more TTY indices left for allocation\n");
+		rv = -ENOMEM;
+		goto free_ldc;
+	}
+
+	/* Register the device using VCC table index as TTY index */
+	dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev);
+	if (IS_ERR(dev)) {
+		rv = PTR_ERR(dev);
+		goto free_table;
+	}
+
+	hp = mdesc_grab();
+
+	node = vio_vdev_node(hp, vdev);
+	if (node == MDESC_NODE_NULL) {
+		rv = -ENXIO;
+		mdesc_release(hp);
+		goto unreg_tty;
+	}
+
+	domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL);
+	if (!domain) {
+		rv = -ENXIO;
+		mdesc_release(hp);
+		goto unreg_tty;
+	}
+	port->domain = kstrdup(domain, GFP_KERNEL);
+	if (!port->domain) {
+		rv = -ENOMEM;
+		goto unreg_tty;
+	}
+
+
+	mdesc_release(hp);
+
+	rv = sysfs_create_group(&vdev->dev.kobj, &vcc_attribute_group);
+	if (rv)
+		goto free_domain;
+
+	timer_setup(&port->rx_timer, vcc_rx_timer, 0);
+	timer_setup(&port->tx_timer, vcc_tx_timer, 0);
+
+	dev_set_drvdata(&vdev->dev, port);
+
+	/* It's possible to receive IRQs in the middle of vio_port_up. Disable
+	 * IRQs until the port is up.
+	 */
+	disable_irq_nosync(vdev->rx_irq);
+	vio_port_up(&port->vio);
+	enable_irq(vdev->rx_irq);
+
+	return 0;
+
+free_domain:
+	kfree(port->domain);
+unreg_tty:
+	tty_unregister_device(vcc_tty_driver, port->index);
+free_table:
+	vcc_table_remove(port->index);
+free_ldc:
+	vio_ldc_free(&port->vio);
+free_name:
+	kfree(name);
+free_port:
+	kfree(port);
+
+	return rv;
+}
+
+/**
+ * vcc_remove() - Terminate a VCC port
+ * @vdev: Pointer to VIO device of the VCC port
+ *
+ * Terminates a VCC port. Sets up the teardown of TTY and
+ * VIO/LDC link between guest and primary domains.
+ *
+ * Return: status of removal
+ */
+static void vcc_remove(struct vio_dev *vdev)
+{
+	struct vcc_port *port = dev_get_drvdata(&vdev->dev);
+
+	del_timer_sync(&port->rx_timer);
+	del_timer_sync(&port->tx_timer);
+
+	/* If there's a process with the device open, do a synchronous
+	 * hangup of the TTY. This *may* cause the process to call close
+	 * asynchronously, but it's not guaranteed.
+	 */
+	if (port->tty)
+		tty_vhangup(port->tty);
+
+	/* Get exclusive reference to VCC, ensures that there are no other
+	 * clients to this port. This cannot fail.
+	 */
+	vcc_get(port->index, true);
+
+	tty_unregister_device(vcc_tty_driver, port->index);
+
+	del_timer_sync(&port->vio.timer);
+	vio_ldc_free(&port->vio);
+	sysfs_remove_group(&vdev->dev.kobj, &vcc_attribute_group);
+	dev_set_drvdata(&vdev->dev, NULL);
+	if (port->tty) {
+		port->removed = true;
+		vcc_put(port, true);
+	} else {
+		vcc_table_remove(port->index);
+
+		kfree(port->vio.name);
+		kfree(port->domain);
+		kfree(port);
+	}
+}
+
+static const struct vio_device_id vcc_match[] = {
+	{
+		.type = "vcc-port",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(vio, vcc_match);
+
+static struct vio_driver vcc_driver = {
+	.id_table	= vcc_match,
+	.probe		= vcc_probe,
+	.remove		= vcc_remove,
+	.name		= "vcc",
+};
+
+static int vcc_open(struct tty_struct *tty, struct file *vcc_file)
+{
+	struct vcc_port *port;
+
+	if (tty->count > 1)
+		return -EBUSY;
+
+	port = vcc_get_ne(tty->index);
+	if (unlikely(!port)) {
+		pr_err("VCC: open: Failed to find VCC port\n");
+		return -ENODEV;
+	}
+
+	if (unlikely(!port->vio.lp)) {
+		pr_err("VCC: open: LDC channel not configured\n");
+		vcc_put(port, false);
+		return -EPIPE;
+	}
+	vccdbgl(port->vio.lp);
+
+	vcc_put(port, false);
+
+	if (unlikely(!tty->port)) {
+		pr_err("VCC: open: TTY port not found\n");
+		return -ENXIO;
+	}
+
+	if (unlikely(!tty->port->ops)) {
+		pr_err("VCC: open: TTY ops not defined\n");
+		return -ENXIO;
+	}
+
+	return tty_port_open(tty->port, tty, vcc_file);
+}
+
+static void vcc_close(struct tty_struct *tty, struct file *vcc_file)
+{
+	if (unlikely(tty->count > 1))
+		return;
+
+	if (unlikely(!tty->port)) {
+		pr_err("VCC: close: TTY port not found\n");
+		return;
+	}
+
+	tty_port_close(tty->port, tty, vcc_file);
+}
+
+static void vcc_ldc_hup(struct vcc_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (vcc_send_ctl(port, VCC_CTL_HUP) < 0)
+		vcc_kick_tx(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void vcc_hangup(struct tty_struct *tty)
+{
+	struct vcc_port *port;
+
+	port = vcc_get_ne(tty->index);
+	if (unlikely(!port)) {
+		pr_err("VCC: hangup: Failed to find VCC port\n");
+		return;
+	}
+
+	if (unlikely(!tty->port)) {
+		pr_err("VCC: hangup: TTY port not found\n");
+		vcc_put(port, false);
+		return;
+	}
+
+	vcc_ldc_hup(port);
+
+	vcc_put(port, false);
+
+	tty_port_hangup(tty->port);
+}
+
+static ssize_t vcc_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	struct vcc_port *port;
+	struct vio_vcc *pkt;
+	unsigned long flags;
+	size_t total_sent = 0;
+	size_t tosend = 0;
+	int rv = -EINVAL;
+
+	port = vcc_get_ne(tty->index);
+	if (unlikely(!port)) {
+		pr_err("VCC: write: Failed to find VCC port");
+		return -ENODEV;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	pkt = &port->buffer;
+	pkt->tag.type = VIO_TYPE_DATA;
+
+	while (count > 0) {
+		/* Minimum of data to write and space available */
+		tosend = min_t(size_t, count,
+			       (VCC_BUFF_LEN - port->chars_in_buffer));
+
+		if (!tosend)
+			break;
+
+		memcpy(&pkt->data[port->chars_in_buffer], &buf[total_sent],
+		       tosend);
+		port->chars_in_buffer += tosend;
+		pkt->tag.stype = tosend;
+
+		vccdbg("TAG [%02x:%02x:%04x:%08x]\n", pkt->tag.type,
+		       pkt->tag.stype, pkt->tag.stype_env, pkt->tag.sid);
+		vccdbg("DATA [%s]\n", pkt->data);
+		vccdbgl(port->vio.lp);
+
+		/* Since we know we have enough room in VCC buffer for tosend
+		 * we record that it was sent regardless of whether the
+		 * hypervisor actually took it because we have it buffered.
+		 */
+		rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend));
+		vccdbg("VCC: write: ldc_write(%zu)=%d\n",
+		       (VIO_TAG_SIZE + tosend), rv);
+
+		total_sent += tosend;
+		count -= tosend;
+		if (rv < 0) {
+			vcc_kick_tx(port);
+			break;
+		}
+
+		port->chars_in_buffer = 0;
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	vcc_put(port, false);
+
+	vccdbg("VCC: write: total=%zu rv=%d", total_sent, rv);
+
+	return total_sent ? total_sent : rv;
+}
+
+static unsigned int vcc_write_room(struct tty_struct *tty)
+{
+	struct vcc_port *port;
+	unsigned int num;
+
+	port = vcc_get_ne(tty->index);
+	if (unlikely(!port)) {
+		pr_err("VCC: write_room: Failed to find VCC port\n");
+		return 0;
+	}
+
+	num = VCC_BUFF_LEN - port->chars_in_buffer;
+
+	vcc_put(port, false);
+
+	return num;
+}
+
+static unsigned int vcc_chars_in_buffer(struct tty_struct *tty)
+{
+	struct vcc_port *port;
+	unsigned int num;
+
+	port = vcc_get_ne(tty->index);
+	if (unlikely(!port)) {
+		pr_err("VCC: chars_in_buffer: Failed to find VCC port\n");
+		return 0;
+	}
+
+	num = port->chars_in_buffer;
+
+	vcc_put(port, false);
+
+	return num;
+}
+
+static int vcc_break_ctl(struct tty_struct *tty, int state)
+{
+	struct vcc_port *port;
+	unsigned long flags;
+
+	port = vcc_get_ne(tty->index);
+	if (unlikely(!port)) {
+		pr_err("VCC: break_ctl: Failed to find VCC port\n");
+		return -ENODEV;
+	}
+
+	/* Turn off break */
+	if (state == 0) {
+		vcc_put(port, false);
+		return 0;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0)
+		vcc_kick_tx(port);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	vcc_put(port, false);
+
+	return 0;
+}
+
+static int vcc_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct vcc_port *port_vcc;
+	struct tty_port *port_tty;
+	int ret;
+
+	if (tty->index >= VCC_MAX_PORTS)
+		return -EINVAL;
+
+	ret = tty_standard_install(driver, tty);
+	if (ret)
+		return ret;
+
+	port_tty = kzalloc(sizeof(struct tty_port), GFP_KERNEL);
+	if (!port_tty)
+		return -ENOMEM;
+
+	port_vcc = vcc_get(tty->index, true);
+	if (!port_vcc) {
+		pr_err("VCC: install: Failed to find VCC port\n");
+		tty->port = NULL;
+		kfree(port_tty);
+		return -ENODEV;
+	}
+
+	tty_port_init(port_tty);
+	port_tty->ops = &vcc_port_ops;
+	tty->port = port_tty;
+
+	port_vcc->tty = tty;
+
+	vcc_put(port_vcc, true);
+
+	return 0;
+}
+
+static void vcc_cleanup(struct tty_struct *tty)
+{
+	struct vcc_port *port;
+
+	port = vcc_get(tty->index, true);
+	if (port) {
+		port->tty = NULL;
+
+		if (port->removed) {
+			vcc_table_remove(tty->index);
+			kfree(port->vio.name);
+			kfree(port->domain);
+			kfree(port);
+		} else {
+			vcc_put(port, true);
+		}
+	}
+
+	tty_port_destroy(tty->port);
+	kfree(tty->port);
+	tty->port = NULL;
+}
+
+static const struct tty_operations vcc_ops = {
+	.open			= vcc_open,
+	.close			= vcc_close,
+	.hangup			= vcc_hangup,
+	.write			= vcc_write,
+	.write_room		= vcc_write_room,
+	.chars_in_buffer	= vcc_chars_in_buffer,
+	.break_ctl		= vcc_break_ctl,
+	.install		= vcc_install,
+	.cleanup		= vcc_cleanup,
+};
+
+#define VCC_TTY_FLAGS   (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW)
+
+static int vcc_tty_init(void)
+{
+	int rv;
+
+	vcc_tty_driver = tty_alloc_driver(VCC_MAX_PORTS, VCC_TTY_FLAGS);
+	if (IS_ERR(vcc_tty_driver)) {
+		pr_err("VCC: TTY driver alloc failed\n");
+		return PTR_ERR(vcc_tty_driver);
+	}
+
+	vcc_tty_driver->driver_name = "vcc";
+	vcc_tty_driver->name = "vcc";
+
+	vcc_tty_driver->minor_start = VCC_MINOR_START;
+	vcc_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
+	vcc_tty_driver->init_termios = vcc_tty_termios;
+
+	tty_set_operations(vcc_tty_driver, &vcc_ops);
+
+	rv = tty_register_driver(vcc_tty_driver);
+	if (rv) {
+		pr_err("VCC: TTY driver registration failed\n");
+		tty_driver_kref_put(vcc_tty_driver);
+		vcc_tty_driver = NULL;
+		return rv;
+	}
+
+	vccdbg("VCC: TTY driver registered\n");
+
+	return 0;
+}
+
+static void vcc_tty_exit(void)
+{
+	tty_unregister_driver(vcc_tty_driver);
+	tty_driver_kref_put(vcc_tty_driver);
+	vccdbg("VCC: TTY driver unregistered\n");
+
+	vcc_tty_driver = NULL;
+}
+
+static int __init vcc_init(void)
+{
+	int rv;
+
+	rv = vcc_tty_init();
+	if (rv) {
+		pr_err("VCC: TTY init failed\n");
+		return rv;
+	}
+
+	rv = vio_register_driver(&vcc_driver);
+	if (rv) {
+		pr_err("VCC: VIO driver registration failed\n");
+		vcc_tty_exit();
+	} else {
+		vccdbg("VCC: VIO driver registered successfully\n");
+	}
+
+	return rv;
+}
+
+static void __exit vcc_exit(void)
+{
+	vio_unregister_driver(&vcc_driver);
+	vccdbg("VCC: VIO driver unregistered\n");
+	vcc_tty_exit();
+	vccdbg("VCC: TTY driver unregistered\n");
+}
+
+module_init(vcc_init);
+module_exit(vcc_exit);
diff --git a/drivers/tty/vt/.gitignore b/drivers/tty/vt/.gitignore
new file mode 100644
index 000000000..0221709b1
--- /dev/null
+++ b/drivers/tty/vt/.gitignore
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+/conmakehash
+/consolemap_deftbl.c
+/defkeymap.c
diff --git a/drivers/tty/vt/Makefile b/drivers/tty/vt/Makefile
new file mode 100644
index 000000000..b3dfe9d57
--- /dev/null
+++ b/drivers/tty/vt/Makefile
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# This file contains the font map for the default (hardware) font
+#
+FONTMAPFILE = cp437.uni
+
+obj-$(CONFIG_VT)			+= vt_ioctl.o vc_screen.o \
+					   selection.o keyboard.o
+obj-$(CONFIG_CONSOLE_TRANSLATIONS)	+= consolemap.o consolemap_deftbl.o
+obj-$(CONFIG_HW_CONSOLE)		+= vt.o defkeymap.o
+
+# Files generated that shall be removed upon make clean
+clean-files := consolemap_deftbl.c defkeymap.c
+
+hostprogs += conmakehash
+
+quiet_cmd_conmk = CONMK   $@
+      cmd_conmk = $(obj)/conmakehash $< > $@
+
+$(obj)/consolemap_deftbl.c: $(src)/$(FONTMAPFILE) $(obj)/conmakehash
+	$(call cmd,conmk)
+
+$(obj)/defkeymap.o:  $(obj)/defkeymap.c
+
+# Uncomment if you're changing the keymap and have an appropriate
+# loadkeys version for the map. By default, we'll use the shipped
+# versions.
+# GENERATE_KEYMAP := 1
+
+ifdef GENERATE_KEYMAP
+
+$(obj)/defkeymap.c: $(obj)/%.c: $(src)/%.map
+	loadkeys --mktable --unicode $< > $@
+
+endif
diff --git a/drivers/tty/vt/conmakehash.c b/drivers/tty/vt/conmakehash.c
new file mode 100644
index 000000000..cddd789fe
--- /dev/null
+++ b/drivers/tty/vt/conmakehash.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * conmakehash.c
+ *
+ * Create arrays for initializing the kernel folded tables (using a hash
+ * table turned out to be to limiting...)  Unfortunately we can't simply
+ * preinitialize the tables at compile time since kfree() cannot accept
+ * memory not allocated by kmalloc(), and doing our own memory management
+ * just for this seems like massive overkill.
+ *
+ * Copyright (C) 1995-1997 H. Peter Anvin
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sysexits.h>
+#include <string.h>
+#include <ctype.h>
+
+#define MAX_FONTLEN 256
+
+typedef unsigned short unicode;
+
+static void usage(char *argv0)
+{
+  fprintf(stderr, "Usage: \n"
+         "        %s chartable [hashsize] [hashstep] [maxhashlevel]\n", argv0);
+  exit(EX_USAGE);
+}
+
+static int getunicode(char **p0)
+{
+  char *p = *p0;
+
+  while (*p == ' ' || *p == '\t')
+    p++;
+  if (*p != 'U' || p[1] != '+' ||
+      !isxdigit(p[2]) || !isxdigit(p[3]) || !isxdigit(p[4]) ||
+      !isxdigit(p[5]) || isxdigit(p[6]))
+    return -1;
+  *p0 = p+6;
+  return strtol(p+2,0,16);
+}
+
+unicode unitable[MAX_FONTLEN][255];
+				/* Massive overkill, but who cares? */
+int unicount[MAX_FONTLEN];
+
+static void addpair(int fp, int un)
+{
+  int i;
+
+  if ( un <= 0xfffe )
+    {
+      /* Check it isn't a duplicate */
+
+      for ( i = 0 ; i < unicount[fp] ; i++ )
+	if ( unitable[fp][i] == un )
+	  return;
+
+      /* Add to list */
+
+      if ( unicount[fp] > 254 )
+	{
+	  fprintf(stderr, "ERROR: Only 255 unicodes/glyph permitted!\n");
+	  exit(EX_DATAERR);
+	}
+
+      unitable[fp][unicount[fp]] = un;
+      unicount[fp]++;
+    }
+
+  /* otherwise: ignore */
+}
+
+int main(int argc, char *argv[])
+{
+  FILE *ctbl;
+  char *tblname;
+  char buffer[65536];
+  int fontlen;
+  int i, nuni, nent;
+  int fp0, fp1, un0, un1;
+  char *p, *p1;
+
+  if ( argc < 2 || argc > 5 )
+    usage(argv[0]);
+
+  if ( !strcmp(argv[1],"-") )
+    {
+      ctbl = stdin;
+      tblname = "stdin";
+    }
+  else
+    {
+      ctbl = fopen(tblname = argv[1], "r");
+      if ( !ctbl )
+	{
+	  perror(tblname);
+	  exit(EX_NOINPUT);
+	}
+    }
+
+  /* For now we assume the default font is always 256 characters. */
+  fontlen = 256;
+
+  /* Initialize table */
+
+  for ( i = 0 ; i < fontlen ; i++ )
+    unicount[i] = 0;
+
+  /* Now we come to the tricky part.  Parse the input table. */
+
+  while ( fgets(buffer, sizeof(buffer), ctbl) != NULL )
+    {
+      if ( (p = strchr(buffer, '\n')) != NULL )
+	*p = '\0';
+      else
+	fprintf(stderr, "%s: Warning: line too long\n", tblname);
+
+      p = buffer;
+
+/*
+ * Syntax accepted:
+ *	<fontpos>	<unicode> <unicode> ...
+ *	<range>		idem
+ *	<range>		<unicode range>
+ *
+ * where <range> ::= <fontpos>-<fontpos>
+ * and <unicode> ::= U+<h><h><h><h>
+ * and <h> ::= <hexadecimal digit>
+ */
+
+      while (*p == ' ' || *p == '\t')
+	p++;
+      if (!*p || *p == '#')
+	continue;	/* skip comment or blank line */
+
+      fp0 = strtol(p, &p1, 0);
+      if (p1 == p)
+	{
+	  fprintf(stderr, "Bad input line: %s\n", buffer);
+	  exit(EX_DATAERR);
+        }
+      p = p1;
+
+      while (*p == ' ' || *p == '\t')
+	p++;
+      if (*p == '-')
+	{
+	  p++;
+	  fp1 = strtol(p, &p1, 0);
+	  if (p1 == p)
+	    {
+	      fprintf(stderr, "Bad input line: %s\n", buffer);
+	      exit(EX_DATAERR);
+	    }
+	  p = p1;
+        }
+      else
+	fp1 = 0;
+
+      if ( fp0 < 0 || fp0 >= fontlen )
+	{
+	    fprintf(stderr,
+		    "%s: Glyph number (0x%x) larger than font length\n",
+		    tblname, fp0);
+	    exit(EX_DATAERR);
+	}
+      if ( fp1 && (fp1 < fp0 || fp1 >= fontlen) )
+	{
+	    fprintf(stderr,
+		    "%s: Bad end of range (0x%x)\n",
+		    tblname, fp1);
+	    exit(EX_DATAERR);
+	}
+
+      if (fp1)
+	{
+	  /* we have a range; expect the word "idem" or a Unicode range of the
+	     same length */
+	  while (*p == ' ' || *p == '\t')
+	    p++;
+	  if (!strncmp(p, "idem", 4))
+	    {
+	      for (i=fp0; i<=fp1; i++)
+		addpair(i,i);
+	      p += 4;
+	    }
+	  else
+	    {
+	      un0 = getunicode(&p);
+	      while (*p == ' ' || *p == '\t')
+		p++;
+	      if (*p != '-')
+		{
+		  fprintf(stderr,
+"%s: Corresponding to a range of font positions, there should be a Unicode range\n",
+			  tblname);
+		  exit(EX_DATAERR);
+	        }
+	      p++;
+	      un1 = getunicode(&p);
+	      if (un0 < 0 || un1 < 0)
+		{
+		  fprintf(stderr,
+"%s: Bad Unicode range corresponding to font position range 0x%x-0x%x\n",
+			  tblname, fp0, fp1);
+		  exit(EX_DATAERR);
+	        }
+	      if (un1 - un0 != fp1 - fp0)
+		{
+		  fprintf(stderr,
+"%s: Unicode range U+%x-U+%x not of the same length as font position range 0x%x-0x%x\n",
+			  tblname, un0, un1, fp0, fp1);
+		  exit(EX_DATAERR);
+	        }
+	      for(i=fp0; i<=fp1; i++)
+		addpair(i,un0-fp0+i);
+	    }
+        }
+      else
+	{
+	    /* no range; expect a list of unicode values for a single font position */
+
+	    while ( (un0 = getunicode(&p)) >= 0 )
+	      addpair(fp0, un0);
+	}
+      while (*p == ' ' || *p == '\t')
+	p++;
+      if (*p && *p != '#')
+	fprintf(stderr, "%s: trailing junk (%s) ignored\n", tblname, p);
+    }
+
+  /* Okay, we hit EOF, now output hash table */
+
+  fclose(ctbl);
+
+
+  /* Compute total size of Unicode list */
+  nuni = 0;
+  for ( i = 0 ; i < fontlen ; i++ )
+    nuni += unicount[i];
+
+  printf("\
+/*\n\
+ * Do not edit this file; it was automatically generated by\n\
+ *\n\
+ * conmakehash %s > [this file]\n\
+ *\n\
+ */\n\
+\n\
+#include <linux/types.h>\n\
+\n\
+u8 dfont_unicount[%d] = \n\
+{\n\t", argv[1], fontlen);
+
+  for ( i = 0 ; i < fontlen ; i++ )
+    {
+      printf("%3d", unicount[i]);
+      if ( i == fontlen-1 )
+        printf("\n};\n");
+      else if ( i % 8 == 7 )
+        printf(",\n\t");
+      else
+        printf(", ");
+    }
+
+  printf("\nu16 dfont_unitable[%d] = \n{\n\t", nuni);
+
+  fp0 = 0;
+  nent = 0;
+  for ( i = 0 ; i < nuni ; i++ )
+    {
+      while ( nent >= unicount[fp0] )
+	{
+	  fp0++;
+	  nent = 0;
+	}
+      printf("0x%04x", unitable[fp0][nent++]);
+      if ( i == nuni-1 )
+         printf("\n};\n");
+       else if ( i % 8 == 7 )
+         printf(",\n\t");
+       else
+         printf(", ");
+    }
+
+  exit(EX_OK);
+}
diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
new file mode 100644
index 000000000..f02d21e2a
--- /dev/null
+++ b/drivers/tty/vt/consolemap.c
@@ -0,0 +1,916 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * consolemap.c
+ *
+ * Mapping from internal code (such as Latin-1 or Unicode or IBM PC code)
+ * to font positions.
+ *
+ * aeb, 950210
+ *
+ * Support for multiple unimaps by Jakub Jelinek <jj@ultra.linux.cz>, July 1998
+ *
+ * Fix bug in inverse translation. Stanislav Voronyi <stas@cnti.uanet.kharkov.ua>, Dec 1998
+ *
+ * In order to prevent the following circular lock dependency:
+ *   &mm->mmap_lock --> cpu_hotplug.lock --> console_lock --> &mm->mmap_lock
+ *
+ * We cannot allow page fault to happen while holding the console_lock.
+ * Therefore, all the userspace copy operations have to be done outside
+ * the console_lock critical sections.
+ *
+ * As all the affected functions are all called directly from vt_ioctl(), we
+ * can allocate some small buffers directly on stack without worrying about
+ * stack overflow.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/module.h>
+#include <linux/kd.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/tty.h>
+#include <linux/uaccess.h>
+#include <linux/console.h>
+#include <linux/consolemap.h>
+#include <linux/vt_kern.h>
+#include <linux/string.h>
+
+static unsigned short translations[][E_TABSZ] = {
+  /* 8-bit Latin-1 mapped to Unicode -- trivial mapping */
+  [LAT1_MAP] = {
+    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
+    0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
+    0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
+    0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
+    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
+    0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
+    0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
+    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
+    0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x007f,
+    0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
+    0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
+    0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
+    0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
+    0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
+    0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
+    0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
+    0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
+    0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
+    0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
+    0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
+    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
+    0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
+    0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
+    0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
+    0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
+  },
+  /* VT100 graphics mapped to Unicode */
+  [GRAF_MAP] = {
+    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
+    0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
+    0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
+    0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
+    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+    0x0028, 0x0029, 0x002a, 0x2192, 0x2190, 0x2191, 0x2193, 0x002f,
+    0x2588, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x00a0,
+    0x25c6, 0x2592, 0x2409, 0x240c, 0x240d, 0x240a, 0x00b0, 0x00b1,
+    0x2591, 0x240b, 0x2518, 0x2510, 0x250c, 0x2514, 0x253c, 0x23ba,
+    0x23bb, 0x2500, 0x23bc, 0x23bd, 0x251c, 0x2524, 0x2534, 0x252c,
+    0x2502, 0x2264, 0x2265, 0x03c0, 0x2260, 0x00a3, 0x00b7, 0x007f,
+    0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
+    0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
+    0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
+    0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
+    0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
+    0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
+    0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
+    0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
+    0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
+    0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
+    0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
+    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
+    0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
+    0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
+    0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
+    0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
+  },
+  /* IBM Codepage 437 mapped to Unicode */
+  [IBMPC_MAP] = {
+    0x0000, 0x263a, 0x263b, 0x2665, 0x2666, 0x2663, 0x2660, 0x2022,
+    0x25d8, 0x25cb, 0x25d9, 0x2642, 0x2640, 0x266a, 0x266b, 0x263c,
+    0x25b6, 0x25c0, 0x2195, 0x203c, 0x00b6, 0x00a7, 0x25ac, 0x21a8,
+    0x2191, 0x2193, 0x2192, 0x2190, 0x221f, 0x2194, 0x25b2, 0x25bc,
+    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
+    0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
+    0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
+    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
+    0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x2302,
+    0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0, 0x00e5, 0x00e7,
+    0x00ea, 0x00eb, 0x00e8, 0x00ef, 0x00ee, 0x00ec, 0x00c4, 0x00c5,
+    0x00c9, 0x00e6, 0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9,
+    0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5, 0x20a7, 0x0192,
+    0x00e1, 0x00ed, 0x00f3, 0x00fa, 0x00f1, 0x00d1, 0x00aa, 0x00ba,
+    0x00bf, 0x2310, 0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb,
+    0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556,
+    0x2555, 0x2563, 0x2551, 0x2557, 0x255d, 0x255c, 0x255b, 0x2510,
+    0x2514, 0x2534, 0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f,
+    0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256c, 0x2567,
+    0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256b,
+    0x256a, 0x2518, 0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580,
+    0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3, 0x00b5, 0x03c4,
+    0x03a6, 0x0398, 0x03a9, 0x03b4, 0x221e, 0x03c6, 0x03b5, 0x2229,
+    0x2261, 0x00b1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248,
+    0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2, 0x25a0, 0x00a0
+  },
+  /* User mapping -- default to codes for direct font mapping */
+  [USER_MAP] = {
+    0xf000, 0xf001, 0xf002, 0xf003, 0xf004, 0xf005, 0xf006, 0xf007,
+    0xf008, 0xf009, 0xf00a, 0xf00b, 0xf00c, 0xf00d, 0xf00e, 0xf00f,
+    0xf010, 0xf011, 0xf012, 0xf013, 0xf014, 0xf015, 0xf016, 0xf017,
+    0xf018, 0xf019, 0xf01a, 0xf01b, 0xf01c, 0xf01d, 0xf01e, 0xf01f,
+    0xf020, 0xf021, 0xf022, 0xf023, 0xf024, 0xf025, 0xf026, 0xf027,
+    0xf028, 0xf029, 0xf02a, 0xf02b, 0xf02c, 0xf02d, 0xf02e, 0xf02f,
+    0xf030, 0xf031, 0xf032, 0xf033, 0xf034, 0xf035, 0xf036, 0xf037,
+    0xf038, 0xf039, 0xf03a, 0xf03b, 0xf03c, 0xf03d, 0xf03e, 0xf03f,
+    0xf040, 0xf041, 0xf042, 0xf043, 0xf044, 0xf045, 0xf046, 0xf047,
+    0xf048, 0xf049, 0xf04a, 0xf04b, 0xf04c, 0xf04d, 0xf04e, 0xf04f,
+    0xf050, 0xf051, 0xf052, 0xf053, 0xf054, 0xf055, 0xf056, 0xf057,
+    0xf058, 0xf059, 0xf05a, 0xf05b, 0xf05c, 0xf05d, 0xf05e, 0xf05f,
+    0xf060, 0xf061, 0xf062, 0xf063, 0xf064, 0xf065, 0xf066, 0xf067,
+    0xf068, 0xf069, 0xf06a, 0xf06b, 0xf06c, 0xf06d, 0xf06e, 0xf06f,
+    0xf070, 0xf071, 0xf072, 0xf073, 0xf074, 0xf075, 0xf076, 0xf077,
+    0xf078, 0xf079, 0xf07a, 0xf07b, 0xf07c, 0xf07d, 0xf07e, 0xf07f,
+    0xf080, 0xf081, 0xf082, 0xf083, 0xf084, 0xf085, 0xf086, 0xf087,
+    0xf088, 0xf089, 0xf08a, 0xf08b, 0xf08c, 0xf08d, 0xf08e, 0xf08f,
+    0xf090, 0xf091, 0xf092, 0xf093, 0xf094, 0xf095, 0xf096, 0xf097,
+    0xf098, 0xf099, 0xf09a, 0xf09b, 0xf09c, 0xf09d, 0xf09e, 0xf09f,
+    0xf0a0, 0xf0a1, 0xf0a2, 0xf0a3, 0xf0a4, 0xf0a5, 0xf0a6, 0xf0a7,
+    0xf0a8, 0xf0a9, 0xf0aa, 0xf0ab, 0xf0ac, 0xf0ad, 0xf0ae, 0xf0af,
+    0xf0b0, 0xf0b1, 0xf0b2, 0xf0b3, 0xf0b4, 0xf0b5, 0xf0b6, 0xf0b7,
+    0xf0b8, 0xf0b9, 0xf0ba, 0xf0bb, 0xf0bc, 0xf0bd, 0xf0be, 0xf0bf,
+    0xf0c0, 0xf0c1, 0xf0c2, 0xf0c3, 0xf0c4, 0xf0c5, 0xf0c6, 0xf0c7,
+    0xf0c8, 0xf0c9, 0xf0ca, 0xf0cb, 0xf0cc, 0xf0cd, 0xf0ce, 0xf0cf,
+    0xf0d0, 0xf0d1, 0xf0d2, 0xf0d3, 0xf0d4, 0xf0d5, 0xf0d6, 0xf0d7,
+    0xf0d8, 0xf0d9, 0xf0da, 0xf0db, 0xf0dc, 0xf0dd, 0xf0de, 0xf0df,
+    0xf0e0, 0xf0e1, 0xf0e2, 0xf0e3, 0xf0e4, 0xf0e5, 0xf0e6, 0xf0e7,
+    0xf0e8, 0xf0e9, 0xf0ea, 0xf0eb, 0xf0ec, 0xf0ed, 0xf0ee, 0xf0ef,
+    0xf0f0, 0xf0f1, 0xf0f2, 0xf0f3, 0xf0f4, 0xf0f5, 0xf0f6, 0xf0f7,
+    0xf0f8, 0xf0f9, 0xf0fa, 0xf0fb, 0xf0fc, 0xf0fd, 0xf0fe, 0xf0ff
+  }
+};
+
+/* The standard kernel character-to-font mappings are not invertible
+   -- this is just a best effort. */
+
+#define MAX_GLYPH 512		/* Max possible glyph value */
+
+static enum translation_map inv_translate[MAX_NR_CONSOLES];
+
+#define UNI_DIRS	32U
+#define UNI_DIR_ROWS	32U
+#define UNI_ROW_GLYPHS	64U
+
+#define UNI_DIR_BITS		GENMASK(15, 11)
+#define UNI_ROW_BITS		GENMASK(10,  6)
+#define UNI_GLYPH_BITS		GENMASK( 5,  0)
+
+#define UNI_DIR(uni)		FIELD_GET(UNI_DIR_BITS, (uni))
+#define UNI_ROW(uni)		FIELD_GET(UNI_ROW_BITS, (uni))
+#define UNI_GLYPH(uni)		FIELD_GET(UNI_GLYPH_BITS, (uni))
+
+#define UNI(dir, row, glyph)	(FIELD_PREP(UNI_DIR_BITS, (dir)) | \
+				 FIELD_PREP(UNI_ROW_BITS, (row)) | \
+				 FIELD_PREP(UNI_GLYPH_BITS, (glyph)))
+
+/**
+ * struct uni_pagedict -- unicode directory
+ *
+ * @uni_pgdir: 32*32*64 table with glyphs
+ * @refcount: reference count of this structure
+ * @sum: checksum
+ * @inverse_translations: best-effort inverse mapping
+ * @inverse_trans_unicode: best-effort inverse mapping to unicode
+ */
+struct uni_pagedict {
+	u16		**uni_pgdir[UNI_DIRS];
+	unsigned long	refcount;
+	unsigned long	sum;
+	unsigned char	*inverse_translations[LAST_MAP + 1];
+	u16		*inverse_trans_unicode;
+};
+
+static struct uni_pagedict *dflt;
+
+static void set_inverse_transl(struct vc_data *conp, struct uni_pagedict *dict,
+	       enum translation_map m)
+{
+	unsigned short *t = translations[m];
+	unsigned char *inv;
+
+	if (!dict)
+		return;
+	inv = dict->inverse_translations[m];
+
+	if (!inv) {
+		inv = dict->inverse_translations[m] = kmalloc(MAX_GLYPH,
+				GFP_KERNEL);
+		if (!inv)
+			return;
+	}
+	memset(inv, 0, MAX_GLYPH);
+
+	for (unsigned int ch = 0; ch < ARRAY_SIZE(translations[m]); ch++) {
+		int glyph = conv_uni_to_pc(conp, t[ch]);
+		if (glyph >= 0 && glyph < MAX_GLYPH && inv[glyph] < 32) {
+			/* prefer '-' above SHY etc. */
+			inv[glyph] = ch;
+		}
+	}
+}
+
+static void set_inverse_trans_unicode(struct uni_pagedict *dict)
+{
+	unsigned int d, r, g;
+	u16 *inv;
+
+	if (!dict)
+		return;
+
+	inv = dict->inverse_trans_unicode;
+	if (!inv) {
+		inv = dict->inverse_trans_unicode = kmalloc_array(MAX_GLYPH,
+				sizeof(*inv), GFP_KERNEL);
+		if (!inv)
+			return;
+	}
+	memset(inv, 0, MAX_GLYPH * sizeof(*inv));
+
+	for (d = 0; d < UNI_DIRS; d++) {
+		u16 **dir = dict->uni_pgdir[d];
+		if (!dir)
+			continue;
+		for (r = 0; r < UNI_DIR_ROWS; r++) {
+			u16 *row = dir[r];
+			if (!row)
+				continue;
+			for (g = 0; g < UNI_ROW_GLYPHS; g++) {
+				u16 glyph = row[g];
+				if (glyph < MAX_GLYPH && inv[glyph] < 32)
+					inv[glyph] = UNI(d, r, g);
+			}
+		}
+	}
+}
+
+unsigned short *set_translate(enum translation_map m, struct vc_data *vc)
+{
+	inv_translate[vc->vc_num] = m;
+	return translations[m];
+}
+
+/*
+ * Inverse translation is impossible for several reasons:
+ * 1. The font<->character maps are not 1-1.
+ * 2. The text may have been written while a different translation map
+ *    was active.
+ * Still, it is now possible to a certain extent to cut and paste non-ASCII.
+ */
+u16 inverse_translate(const struct vc_data *conp, u16 glyph, bool use_unicode)
+{
+	struct uni_pagedict *p;
+	enum translation_map m;
+
+	if (glyph >= MAX_GLYPH)
+		return 0;
+
+	p = *conp->uni_pagedict_loc;
+	if (!p)
+		return glyph;
+
+	if (use_unicode) {
+		if (!p->inverse_trans_unicode)
+			return glyph;
+
+		return p->inverse_trans_unicode[glyph];
+	}
+
+	m = inv_translate[conp->vc_num];
+	if (!p->inverse_translations[m])
+		return glyph;
+
+	return p->inverse_translations[m][glyph];
+}
+EXPORT_SYMBOL_GPL(inverse_translate);
+
+static void update_user_maps(void)
+{
+	int i;
+	struct uni_pagedict *p, *q = NULL;
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		if (!vc_cons_allocated(i))
+			continue;
+		p = *vc_cons[i].d->uni_pagedict_loc;
+		if (p && p != q) {
+			set_inverse_transl(vc_cons[i].d, p, USER_MAP);
+			set_inverse_trans_unicode(p);
+			q = p;
+		}
+	}
+}
+
+/*
+ * Load customizable translation table
+ * arg points to a 256 byte translation table.
+ *
+ * The "old" variants are for translation directly to font (using the
+ * 0xf000-0xf0ff "transparent" Unicodes) whereas the "new" variants set
+ * Unicodes explicitly.
+ */
+int con_set_trans_old(unsigned char __user * arg)
+{
+	unsigned short inbuf[E_TABSZ];
+	unsigned int i;
+	unsigned char ch;
+
+	for (i = 0; i < ARRAY_SIZE(inbuf); i++) {
+		if (get_user(ch, &arg[i]))
+			return -EFAULT;
+		inbuf[i] = UNI_DIRECT_BASE | ch;
+	}
+
+	console_lock();
+	memcpy(translations[USER_MAP], inbuf, sizeof(inbuf));
+	update_user_maps();
+	console_unlock();
+	return 0;
+}
+
+int con_get_trans_old(unsigned char __user * arg)
+{
+	int i, ch;
+	unsigned short *p = translations[USER_MAP];
+	unsigned char outbuf[E_TABSZ];
+
+	console_lock();
+	for (i = 0; i < ARRAY_SIZE(outbuf); i++)
+	{
+		ch = conv_uni_to_pc(vc_cons[fg_console].d, p[i]);
+		outbuf[i] = (ch & ~0xff) ? 0 : ch;
+	}
+	console_unlock();
+
+	return copy_to_user(arg, outbuf, sizeof(outbuf)) ? -EFAULT : 0;
+}
+
+int con_set_trans_new(ushort __user * arg)
+{
+	unsigned short inbuf[E_TABSZ];
+
+	if (copy_from_user(inbuf, arg, sizeof(inbuf)))
+		return -EFAULT;
+
+	console_lock();
+	memcpy(translations[USER_MAP], inbuf, sizeof(inbuf));
+	update_user_maps();
+	console_unlock();
+	return 0;
+}
+
+int con_get_trans_new(ushort __user * arg)
+{
+	unsigned short outbuf[E_TABSZ];
+
+	console_lock();
+	memcpy(outbuf, translations[USER_MAP], sizeof(outbuf));
+	console_unlock();
+
+	return copy_to_user(arg, outbuf, sizeof(outbuf)) ? -EFAULT : 0;
+}
+
+/*
+ * Unicode -> current font conversion
+ *
+ * A font has at most 512 chars, usually 256.
+ * But one font position may represent several Unicode chars.
+ * A hashtable is somewhat of a pain to deal with, so use a
+ * "paged table" instead.  Simulation has shown the memory cost of
+ * this 3-level paged table scheme to be comparable to a hash table.
+ */
+
+extern u8 dfont_unicount[];	/* Defined in console_defmap.c */
+extern u16 dfont_unitable[];
+
+static void con_release_unimap(struct uni_pagedict *dict)
+{
+	unsigned int d, r;
+
+	if (dict == dflt)
+		dflt = NULL;
+
+	for (d = 0; d < UNI_DIRS; d++) {
+		u16 **dir = dict->uni_pgdir[d];
+		if (dir != NULL) {
+			for (r = 0; r < UNI_DIR_ROWS; r++)
+				kfree(dir[r]);
+			kfree(dir);
+		}
+		dict->uni_pgdir[d] = NULL;
+	}
+
+	for (r = 0; r < ARRAY_SIZE(dict->inverse_translations); r++) {
+		kfree(dict->inverse_translations[r]);
+		dict->inverse_translations[r] = NULL;
+	}
+
+	kfree(dict->inverse_trans_unicode);
+	dict->inverse_trans_unicode = NULL;
+}
+
+/* Caller must hold the console lock */
+void con_free_unimap(struct vc_data *vc)
+{
+	struct uni_pagedict *p;
+
+	p = *vc->uni_pagedict_loc;
+	if (!p)
+		return;
+	*vc->uni_pagedict_loc = NULL;
+	if (--p->refcount)
+		return;
+	con_release_unimap(p);
+	kfree(p);
+}
+
+static int con_unify_unimap(struct vc_data *conp, struct uni_pagedict *dict1)
+{
+	struct uni_pagedict *dict2;
+	unsigned int cons, d, r;
+
+	for (cons = 0; cons < MAX_NR_CONSOLES; cons++) {
+		if (!vc_cons_allocated(cons))
+			continue;
+		dict2 = *vc_cons[cons].d->uni_pagedict_loc;
+		if (!dict2 || dict2 == dict1 || dict2->sum != dict1->sum)
+			continue;
+		for (d = 0; d < UNI_DIRS; d++) {
+			u16 **dir1 = dict1->uni_pgdir[d];
+			u16 **dir2 = dict2->uni_pgdir[d];
+			if (!dir1 && !dir2)
+				continue;
+			if (!dir1 || !dir2)
+				break;
+			for (r = 0; r < UNI_DIR_ROWS; r++) {
+				if (!dir1[r] && !dir2[r])
+					continue;
+				if (!dir1[r] || !dir2[r])
+					break;
+				if (memcmp(dir1[r], dir2[r], UNI_ROW_GLYPHS *
+							sizeof(*dir1[r])))
+					break;
+			}
+			if (r < UNI_DIR_ROWS)
+				break;
+		}
+		if (d == UNI_DIRS) {
+			dict2->refcount++;
+			*conp->uni_pagedict_loc = dict2;
+			con_release_unimap(dict1);
+			kfree(dict1);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int
+con_insert_unipair(struct uni_pagedict *p, u_short unicode, u_short fontpos)
+{
+	u16 **dir, *row;
+	unsigned int n;
+
+	n = UNI_DIR(unicode);
+	dir = p->uni_pgdir[n];
+	if (!dir) {
+		dir = p->uni_pgdir[n] = kcalloc(UNI_DIR_ROWS, sizeof(*dir),
+				GFP_KERNEL);
+		if (!dir)
+			return -ENOMEM;
+	}
+
+	n = UNI_ROW(unicode);
+	row = dir[n];
+	if (!row) {
+		row = dir[n] = kmalloc_array(UNI_ROW_GLYPHS, sizeof(*row),
+				GFP_KERNEL);
+		if (!row)
+			return -ENOMEM;
+		/* No glyphs for the characters (yet) */
+		memset(row, 0xff, UNI_ROW_GLYPHS * sizeof(*row));
+	}
+
+	row[UNI_GLYPH(unicode)] = fontpos;
+
+	p->sum += (fontpos << 20U) + unicode;
+
+	return 0;
+}
+
+static int con_allocate_new(struct vc_data *vc)
+{
+	struct uni_pagedict *new, *old = *vc->uni_pagedict_loc;
+
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		return -ENOMEM;
+
+	new->refcount = 1;
+	*vc->uni_pagedict_loc = new;
+
+	if (old)
+		old->refcount--;
+
+	return 0;
+}
+
+/* Caller must hold the lock */
+static int con_do_clear_unimap(struct vc_data *vc)
+{
+	struct uni_pagedict *old = *vc->uni_pagedict_loc;
+
+	if (!old || old->refcount > 1)
+		return con_allocate_new(vc);
+
+	old->sum = 0;
+	con_release_unimap(old);
+
+	return 0;
+}
+
+int con_clear_unimap(struct vc_data *vc)
+{
+	int ret;
+	console_lock();
+	ret = con_do_clear_unimap(vc);
+	console_unlock();
+	return ret;
+}
+
+static struct uni_pagedict *con_unshare_unimap(struct vc_data *vc,
+		struct uni_pagedict *old)
+{
+	struct uni_pagedict *new;
+	unsigned int d, r, g;
+	int ret;
+	u16 uni = 0;
+
+	ret = con_allocate_new(vc);
+	if (ret)
+		return ERR_PTR(ret);
+
+	new = *vc->uni_pagedict_loc;
+
+	/*
+	 * uni_pgdir is a 32*32*64 table with rows allocated when its first
+	 * entry is added. The unicode value must still be incremented for
+	 * empty rows. We are copying entries from "old" to "new".
+	 */
+	for (d = 0; d < UNI_DIRS; d++) {
+		u16 **dir = old->uni_pgdir[d];
+		if (!dir) {
+			/* Account for empty table */
+			uni += UNI_DIR_ROWS * UNI_ROW_GLYPHS;
+			continue;
+		}
+
+		for (r = 0; r < UNI_DIR_ROWS; r++) {
+			u16 *row = dir[r];
+			if (!row) {
+				/* Account for row of 64 empty entries */
+				uni += UNI_ROW_GLYPHS;
+				continue;
+			}
+
+			for (g = 0; g < UNI_ROW_GLYPHS; g++, uni++) {
+				if (row[g] == 0xffff)
+					continue;
+				/*
+				 * Found one, copy entry for unicode uni with
+				 * fontpos value row[g].
+				 */
+				ret = con_insert_unipair(new, uni, row[g]);
+				if (ret) {
+					old->refcount++;
+					*vc->uni_pagedict_loc = old;
+					con_release_unimap(new);
+					kfree(new);
+					return ERR_PTR(ret);
+				}
+			}
+		}
+	}
+
+	return new;
+}
+
+int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
+{
+	int err = 0, err1;
+	struct uni_pagedict *dict;
+	struct unipair *unilist, *plist;
+
+	if (!ct)
+		return 0;
+
+	unilist = vmemdup_user(list, array_size(sizeof(*unilist), ct));
+	if (IS_ERR(unilist))
+		return PTR_ERR(unilist);
+
+	console_lock();
+
+	/* Save original vc_unipagdir_loc in case we allocate a new one */
+	dict = *vc->uni_pagedict_loc;
+	if (!dict) {
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	if (dict->refcount > 1) {
+		dict = con_unshare_unimap(vc, dict);
+		if (IS_ERR(dict)) {
+			err = PTR_ERR(dict);
+			goto out_unlock;
+		}
+	} else if (dict == dflt) {
+		dflt = NULL;
+	}
+
+	/*
+	 * Insert user specified unicode pairs into new table.
+	 */
+	for (plist = unilist; ct; ct--, plist++) {
+		err1 = con_insert_unipair(dict, plist->unicode, plist->fontpos);
+		if (err1)
+			err = err1;
+	}
+
+	/*
+	 * Merge with fontmaps of any other virtual consoles.
+	 */
+	if (con_unify_unimap(vc, dict))
+		goto out_unlock;
+
+	for (enum translation_map m = FIRST_MAP; m <= LAST_MAP; m++)
+		set_inverse_transl(vc, dict, m);
+	set_inverse_trans_unicode(dict);
+
+out_unlock:
+	console_unlock();
+	kvfree(unilist);
+	return err;
+}
+
+/**
+ *	con_set_default_unimap	-	set default unicode map
+ *	@vc: the console we are updating
+ *
+ *	Loads the unimap for the hardware font, as defined in uni_hash.tbl.
+ *	The representation used was the most compact I could come up
+ *	with.  This routine is executed at video setup, and when the
+ *	PIO_FONTRESET ioctl is called.
+ *
+ *	The caller must hold the console lock
+ */
+int con_set_default_unimap(struct vc_data *vc)
+{
+	struct uni_pagedict *dict;
+	unsigned int fontpos, count;
+	int err = 0, err1;
+	u16 *dfont;
+
+	if (dflt) {
+		dict = *vc->uni_pagedict_loc;
+		if (dict == dflt)
+			return 0;
+
+		dflt->refcount++;
+		*vc->uni_pagedict_loc = dflt;
+		if (dict && !--dict->refcount) {
+			con_release_unimap(dict);
+			kfree(dict);
+		}
+		return 0;
+	}
+
+	/* The default font is always 256 characters */
+
+	err = con_do_clear_unimap(vc);
+	if (err)
+		return err;
+
+	dict = *vc->uni_pagedict_loc;
+	dfont = dfont_unitable;
+
+	for (fontpos = 0; fontpos < 256U; fontpos++)
+		for (count = dfont_unicount[fontpos]; count; count--) {
+			err1 = con_insert_unipair(dict, *(dfont++), fontpos);
+			if (err1)
+				err = err1;
+		}
+
+	if (con_unify_unimap(vc, dict)) {
+		dflt = *vc->uni_pagedict_loc;
+		return err;
+	}
+
+	for (enum translation_map m = FIRST_MAP; m <= LAST_MAP; m++)
+		set_inverse_transl(vc, dict, m);
+	set_inverse_trans_unicode(dict);
+	dflt = dict;
+	return err;
+}
+EXPORT_SYMBOL(con_set_default_unimap);
+
+/**
+ *	con_copy_unimap		-	copy unimap between two vts
+ *	@dst_vc: target
+ *	@src_vc: source
+ *
+ *	The caller must hold the console lock when invoking this method
+ */
+int con_copy_unimap(struct vc_data *dst_vc, struct vc_data *src_vc)
+{
+	struct uni_pagedict *src;
+
+	if (!*src_vc->uni_pagedict_loc)
+		return -EINVAL;
+	if (*dst_vc->uni_pagedict_loc == *src_vc->uni_pagedict_loc)
+		return 0;
+	con_free_unimap(dst_vc);
+	src = *src_vc->uni_pagedict_loc;
+	src->refcount++;
+	*dst_vc->uni_pagedict_loc = src;
+	return 0;
+}
+EXPORT_SYMBOL(con_copy_unimap);
+
+/*
+ *	con_get_unimap		-	get the unicode map
+ *
+ *	Read the console unicode data for this console. Called from the ioctl
+ *	handlers.
+ */
+int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct,
+		struct unipair __user *list)
+{
+	ushort ect;
+	struct uni_pagedict *dict;
+	struct unipair *unilist;
+	unsigned int d, r, g;
+	int ret = 0;
+
+	unilist = kvmalloc_array(ct, sizeof(*unilist), GFP_KERNEL);
+	if (!unilist)
+		return -ENOMEM;
+
+	console_lock();
+
+	ect = 0;
+	dict = *vc->uni_pagedict_loc;
+	if (!dict)
+		goto unlock;
+
+	for (d = 0; d < UNI_DIRS; d++) {
+		u16 **dir = dict->uni_pgdir[d];
+		if (!dir)
+			continue;
+
+		for (r = 0; r < UNI_DIR_ROWS; r++) {
+			u16 *row = dir[r];
+			if (!row)
+				continue;
+
+			for (g = 0; g < UNI_ROW_GLYPHS; g++, row++) {
+				if (*row >= MAX_GLYPH)
+					continue;
+				if (ect < ct) {
+					unilist[ect].unicode = UNI(d, r, g);
+					unilist[ect].fontpos = *row;
+				}
+				ect++;
+			}
+		}
+	}
+unlock:
+	console_unlock();
+	if (copy_to_user(list, unilist, min(ect, ct) * sizeof(*unilist)))
+		ret = -EFAULT;
+	if (put_user(ect, uct))
+		ret = -EFAULT;
+	kvfree(unilist);
+	return ret ? ret : (ect <= ct) ? 0 : -ENOMEM;
+}
+
+/*
+ * Always use USER_MAP. These functions are used by the keyboard,
+ * which shouldn't be affected by G0/G1 switching, etc.
+ * If the user map still contains default values, i.e. the
+ * direct-to-font mapping, then assume user is using Latin1.
+ *
+ * FIXME: at some point we need to decide if we want to lock the table
+ * update element itself via the keyboard_event_lock for consistency with the
+ * keyboard driver as well as the consoles
+ */
+/* may be called during an interrupt */
+u32 conv_8bit_to_uni(unsigned char c)
+{
+	unsigned short uni = translations[USER_MAP][c];
+	return uni == (0xf000 | c) ? c : uni;
+}
+
+int conv_uni_to_8bit(u32 uni)
+{
+	int c;
+	for (c = 0; c < ARRAY_SIZE(translations[USER_MAP]); c++)
+		if (translations[USER_MAP][c] == uni ||
+		   (translations[USER_MAP][c] == (c | 0xf000) && uni == c))
+			return c;
+	return -1;
+}
+
+int conv_uni_to_pc(struct vc_data *conp, long ucs)
+{
+	struct uni_pagedict *dict;
+	u16 **dir, *row, glyph;
+
+	/* Only 16-bit codes supported at this time */
+	if (ucs > 0xffff)
+		return -4;		/* Not found */
+	else if (ucs < 0x20)
+		return -1;		/* Not a printable character */
+	else if (ucs == 0xfeff || (ucs >= 0x200b && ucs <= 0x200f))
+		return -2;			/* Zero-width space */
+	/*
+	 * UNI_DIRECT_BASE indicates the start of the region in the User Zone
+	 * which always has a 1:1 mapping to the currently loaded font.  The
+	 * UNI_DIRECT_MASK indicates the bit span of the region.
+	 */
+	else if ((ucs & ~UNI_DIRECT_MASK) == UNI_DIRECT_BASE)
+		return ucs & UNI_DIRECT_MASK;
+
+	dict = *conp->uni_pagedict_loc;
+	if (!dict)
+		return -3;
+
+	dir = dict->uni_pgdir[UNI_DIR(ucs)];
+	if (!dir)
+		return -4;
+
+	row = dir[UNI_ROW(ucs)];
+	if (!row)
+		return -4;
+
+	glyph = row[UNI_GLYPH(ucs)];
+	if (glyph >= MAX_GLYPH)
+		return -4;
+
+	return glyph;
+}
+
+/*
+ * This is called at sys_setup time, after memory and the console are
+ * initialized.  It must be possible to call kmalloc(..., GFP_KERNEL)
+ * from this function, hence the call from sys_setup.
+ */
+void __init
+console_map_init(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++)
+		if (vc_cons_allocated(i) && !*vc_cons[i].d->uni_pagedict_loc)
+			con_set_default_unimap(vc_cons[i].d);
+}
+
diff --git a/drivers/tty/vt/cp437.uni b/drivers/tty/vt/cp437.uni
new file mode 100644
index 000000000..a1991904c
--- /dev/null
+++ b/drivers/tty/vt/cp437.uni
@@ -0,0 +1,292 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Unicode table for IBM Codepage 437.  Note that there are many more
+# substitutions that could be conceived (for example, thick-line
+# graphs probably should be replaced with double-line ones, accented
+# Latin characters should replaced with their nonaccented versions,
+# and some upper case Greek characters could be replaced by Latin), however,
+# I have limited myself to the Unicodes used by the kernel ISO 8859-1,
+# DEC VT, and IBM CP 437 tables.
+#
+# --------------------------------
+#
+# Basic IBM dingbats, some of which will never have a purpose clear
+# to mankind
+#
+0x00	U+0000
+0x01	U+263a
+0x02	U+263b
+0x03	U+2665
+0x04	U+2666 U+25c6
+0x05	U+2663
+0x06	U+2660
+0x07	U+2022
+0x08	U+25d8
+0x09	U+25cb
+0x0a	U+25d9
+0x0b	U+2642
+0x0c	U+2640
+0x0d	U+266a
+0x0e	U+266b
+0x0f	U+263c U+00a4
+0x10	U+25b6 U+25ba
+0x11	U+25c0 U+25c4
+0x12	U+2195
+0x13	U+203c
+0x14	U+00b6
+0x15	U+00a7
+0x16	U+25ac
+0x17	U+21a8
+0x18	U+2191
+0x19	U+2193
+0x1a	U+2192
+0x1b	U+2190
+0x1c	U+221f
+0x1d	U+2194
+0x1e	U+25b2
+0x1f	U+25bc
+#
+# The ASCII range is identity-mapped, but some of the characters also
+# have to act as substitutes, especially the upper-case characters.
+#
+0x20	U+0020
+0x21	U+0021
+0x22	U+0022 U+00a8
+0x23	U+0023
+0x24	U+0024
+0x25	U+0025
+0x26	U+0026
+0x27	U+0027 U+00b4
+0x28	U+0028
+0x29	U+0029
+0x2a	U+002a
+0x2b	U+002b
+0x2c	U+002c U+00b8
+0x2d	U+002d U+00ad
+0x2e	U+002e
+0x2f	U+002f
+0x30	U+0030
+0x31	U+0031
+0x32	U+0032
+0x33	U+0033
+0x34	U+0034
+0x35	U+0035
+0x36	U+0036
+0x37	U+0037
+0x38	U+0038
+0x39	U+0039
+0x3a	U+003a
+0x3b	U+003b
+0x3c	U+003c
+0x3d	U+003d
+0x3e	U+003e
+0x3f	U+003f
+0x40	U+0040
+0x41	U+0041 U+00c0 U+00c1 U+00c2 U+00c3
+0x42	U+0042
+0x43	U+0043 U+00a9
+0x44	U+0044 U+00d0
+0x45	U+0045 U+00c8 U+00ca U+00cb
+0x46	U+0046
+0x47	U+0047
+0x48	U+0048
+0x49	U+0049 U+00cc U+00cd U+00ce U+00cf
+0x4a	U+004a
+0x4b	U+004b U+212a
+0x4c	U+004c
+0x4d	U+004d
+0x4e	U+004e
+0x4f	U+004f U+00d2 U+00d3 U+00d4 U+00d5
+0x50	U+0050
+0x51	U+0051
+0x52	U+0052 U+00ae
+0x53	U+0053
+0x54	U+0054
+0x55	U+0055 U+00d9 U+00da U+00db
+0x56	U+0056
+0x57	U+0057
+0x58	U+0058
+0x59	U+0059 U+00dd
+0x5a	U+005a
+0x5b	U+005b
+0x5c	U+005c
+0x5d	U+005d
+0x5e	U+005e
+0x5f	U+005f U+23bd U+f804
+0x60	U+0060
+0x61	U+0061 U+00e3
+0x62	U+0062
+0x63	U+0063
+0x64	U+0064
+0x65	U+0065
+0x66	U+0066
+0x67	U+0067
+0x68	U+0068
+0x69	U+0069
+0x6a	U+006a
+0x6b	U+006b
+0x6c	U+006c
+0x6d	U+006d
+0x6e	U+006e
+0x6f	U+006f U+00f5
+0x70	U+0070
+0x71	U+0071
+0x72	U+0072
+0x73	U+0073
+0x74	U+0074
+0x75	U+0075
+0x76	U+0076
+0x77	U+0077
+0x78	U+0078 U+00d7
+0x79	U+0079 U+00fd
+0x7a	U+007a
+0x7b	U+007b
+0x7c	U+007c U+00a6
+0x7d	U+007d
+0x7e	U+007e
+#
+# Okay, what on Earth is this one supposed to be used for?
+#
+0x7f	U+2302
+#
+# Non-English characters, mostly lower case letters...
+#
+0x80	U+00c7
+0x81	U+00fc
+0x82	U+00e9
+0x83	U+00e2
+0x84	U+00e4
+0x85	U+00e0
+0x86	U+00e5
+0x87	U+00e7
+0x88	U+00ea
+0x89	U+00eb
+0x8a	U+00e8
+0x8b	U+00ef
+0x8c	U+00ee
+0x8d	U+00ec
+0x8e	U+00c4
+0x8f	U+00c5 U+212b
+0x90	U+00c9
+0x91	U+00e6
+0x92	U+00c6
+0x93	U+00f4
+0x94	U+00f6
+0x95	U+00f2
+0x96	U+00fb
+0x97	U+00f9
+0x98	U+00ff
+0x99	U+00d6
+0x9a	U+00dc
+0x9b	U+00a2
+0x9c	U+00a3
+0x9d	U+00a5
+0x9e	U+20a7
+0x9f	U+0192
+0xa0	U+00e1
+0xa1	U+00ed
+0xa2	U+00f3
+0xa3	U+00fa
+0xa4	U+00f1
+0xa5	U+00d1
+0xa6	U+00aa
+0xa7	U+00ba
+0xa8	U+00bf
+0xa9	U+2310
+0xaa	U+00ac
+0xab	U+00bd
+0xac	U+00bc
+0xad	U+00a1
+0xae	U+00ab
+0xaf	U+00bb
+#
+# Block graphics
+#
+0xb0	U+2591
+0xb1	U+2592
+0xb2	U+2593
+0xb3	U+2502
+0xb4	U+2524
+0xb5	U+2561
+0xb6	U+2562
+0xb7	U+2556
+0xb8	U+2555
+0xb9	U+2563
+0xba	U+2551
+0xbb	U+2557
+0xbc	U+255d
+0xbd	U+255c
+0xbe	U+255b
+0xbf	U+2510
+0xc0	U+2514
+0xc1	U+2534
+0xc2	U+252c
+0xc3	U+251c
+0xc4	U+2500
+0xc5	U+253c
+0xc6	U+255e
+0xc7	U+255f
+0xc8	U+255a
+0xc9	U+2554
+0xca	U+2569
+0xcb	U+2566
+0xcc	U+2560
+0xcd	U+2550
+0xce	U+256c
+0xcf	U+2567
+0xd0	U+2568
+0xd1	U+2564
+0xd2	U+2565
+0xd3	U+2559
+0xd4	U+2558
+0xd5	U+2552
+0xd6	U+2553
+0xd7	U+256b
+0xd8	U+256a
+0xd9	U+2518
+0xda	U+250c
+0xdb	U+2588
+0xdc	U+2584
+0xdd	U+258c
+0xde	U+2590
+0xdf	U+2580
+#
+# Greek letters and mathematical symbols
+#
+0xe0	U+03b1
+0xe1	U+03b2 U+00df
+0xe2	U+0393
+0xe3	U+03c0
+0xe4	U+03a3
+0xe5	U+03c3
+0xe6	U+00b5 U+03bc
+0xe7	U+03c4
+0xe8	U+03a6 U+00d8
+0xe9	U+0398
+0xea	U+03a9 U+2126
+0xeb	U+03b4 U+00f0
+0xec	U+221e
+0xed	U+03c6 U+00f8
+0xee	U+03b5 U+2208
+0xef	U+2229
+0xf0	U+2261
+0xf1	U+00b1
+0xf2	U+2265
+0xf3	U+2264
+0xf4	U+2320
+0xf5	U+2321
+0xf6	U+00f7
+0xf7	U+2248
+0xf8	U+00b0
+0xf9	U+2219
+0xfa	U+00b7
+0xfb	U+221a
+0xfc	U+207f
+0xfd	U+00b2
+#
+# Square bullet, non-spacing blank
+# Mapping U+fffd to the square bullet means it is the substitution
+# character
+# 
+0xfe	U+25a0 U+fffd
+0xff	U+00a0
diff --git a/drivers/tty/vt/defkeymap.c_shipped b/drivers/tty/vt/defkeymap.c_shipped
new file mode 100644
index 000000000..0c043e4f2
--- /dev/null
+++ b/drivers/tty/vt/defkeymap.c_shipped
@@ -0,0 +1,263 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Do not edit this file! It was automatically generated by     */
+/*    loadkeys --mktable --unicode defkeymap.map > defkeymap.c  */
+
+#include <linux/types.h>
+#include <linux/keyboard.h>
+#include <linux/kd.h>
+
+unsigned short plain_map[NR_KEYS] = {
+	0xf200,	0xf01b,	0xf031,	0xf032,	0xf033,	0xf034,	0xf035,	0xf036,
+	0xf037,	0xf038,	0xf039,	0xf030,	0xf02d,	0xf03d,	0xf07f,	0xf009,
+	0xfb71,	0xfb77,	0xfb65,	0xfb72,	0xfb74,	0xfb79,	0xfb75,	0xfb69,
+	0xfb6f,	0xfb70,	0xf05b,	0xf05d,	0xf201,	0xf702,	0xfb61,	0xfb73,
+	0xfb64,	0xfb66,	0xfb67,	0xfb68,	0xfb6a,	0xfb6b,	0xfb6c,	0xf03b,
+	0xf027,	0xf060,	0xf700,	0xf05c,	0xfb7a,	0xfb78,	0xfb63,	0xfb76,
+	0xfb62,	0xfb6e,	0xfb6d,	0xf02c,	0xf02e,	0xf02f,	0xf700,	0xf30c,
+	0xf703,	0xf020,	0xf207,	0xf100,	0xf101,	0xf102,	0xf103,	0xf104,
+	0xf105,	0xf106,	0xf107,	0xf108,	0xf109,	0xf208,	0xf209,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf03c,	0xf10a,
+	0xf10b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf01c,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+static unsigned short shift_map[NR_KEYS] = {
+	0xf200,	0xf01b,	0xf021,	0xf040,	0xf023,	0xf024,	0xf025,	0xf05e,
+	0xf026,	0xf02a,	0xf028,	0xf029,	0xf05f,	0xf02b,	0xf07f,	0xf009,
+	0xfb51,	0xfb57,	0xfb45,	0xfb52,	0xfb54,	0xfb59,	0xfb55,	0xfb49,
+	0xfb4f,	0xfb50,	0xf07b,	0xf07d,	0xf201,	0xf702,	0xfb41,	0xfb53,
+	0xfb44,	0xfb46,	0xfb47,	0xfb48,	0xfb4a,	0xfb4b,	0xfb4c,	0xf03a,
+	0xf022,	0xf07e,	0xf700,	0xf07c,	0xfb5a,	0xfb58,	0xfb43,	0xfb56,
+	0xfb42,	0xfb4e,	0xfb4d,	0xf03c,	0xf03e,	0xf03f,	0xf700,	0xf30c,
+	0xf703,	0xf020,	0xf207,	0xf10a,	0xf10b,	0xf10c,	0xf10d,	0xf10e,
+	0xf10f,	0xf110,	0xf111,	0xf112,	0xf113,	0xf213,	0xf203,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf03e,	0xf10a,
+	0xf10b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf20b,	0xf601,	0xf602,	0xf117,	0xf600,	0xf20a,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+static unsigned short altgr_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf040,	0xf200,	0xf024,	0xf200,	0xf200,
+	0xf07b,	0xf05b,	0xf05d,	0xf07d,	0xf05c,	0xf200,	0xf200,	0xf200,
+	0xfb71,	0xfb77,	0xf918,	0xfb72,	0xfb74,	0xfb79,	0xfb75,	0xfb69,
+	0xfb6f,	0xfb70,	0xf200,	0xf07e,	0xf201,	0xf702,	0xf914,	0xfb73,
+	0xf917,	0xf919,	0xfb67,	0xfb68,	0xfb6a,	0xfb6b,	0xfb6c,	0xf200,
+	0xf200,	0xf200,	0xf700,	0xf200,	0xfb7a,	0xfb78,	0xf916,	0xfb76,
+	0xf915,	0xfb6e,	0xfb6d,	0xf200,	0xf200,	0xf200,	0xf700,	0xf30c,
+	0xf703,	0xf200,	0xf207,	0xf50c,	0xf50d,	0xf50e,	0xf50f,	0xf510,
+	0xf511,	0xf512,	0xf513,	0xf514,	0xf515,	0xf208,	0xf202,	0xf911,
+	0xf912,	0xf913,	0xf30b,	0xf90e,	0xf90f,	0xf910,	0xf30a,	0xf90b,
+	0xf90c,	0xf90d,	0xf90a,	0xf310,	0xf206,	0xf200,	0xf07c,	0xf516,
+	0xf517,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+static unsigned short ctrl_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf000,	0xf01b,	0xf01c,	0xf01d,	0xf01e,
+	0xf01f,	0xf07f,	0xf200,	0xf200,	0xf01f,	0xf200,	0xf008,	0xf200,
+	0xf011,	0xf017,	0xf005,	0xf012,	0xf014,	0xf019,	0xf015,	0xf009,
+	0xf00f,	0xf010,	0xf01b,	0xf01d,	0xf201,	0xf702,	0xf001,	0xf013,
+	0xf004,	0xf006,	0xf007,	0xf008,	0xf00a,	0xf00b,	0xf00c,	0xf200,
+	0xf007,	0xf000,	0xf700,	0xf01c,	0xf01a,	0xf018,	0xf003,	0xf016,
+	0xf002,	0xf00e,	0xf00d,	0xf200,	0xf20e,	0xf07f,	0xf700,	0xf30c,
+	0xf703,	0xf000,	0xf207,	0xf100,	0xf101,	0xf102,	0xf103,	0xf104,
+	0xf105,	0xf106,	0xf107,	0xf108,	0xf109,	0xf208,	0xf204,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf200,	0xf10a,
+	0xf10b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf01c,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+static unsigned short shift_ctrl_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf000,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf01f,	0xf200,	0xf200,	0xf200,
+	0xf011,	0xf017,	0xf005,	0xf012,	0xf014,	0xf019,	0xf015,	0xf009,
+	0xf00f,	0xf010,	0xf200,	0xf200,	0xf201,	0xf702,	0xf001,	0xf013,
+	0xf004,	0xf006,	0xf007,	0xf008,	0xf00a,	0xf00b,	0xf00c,	0xf200,
+	0xf200,	0xf200,	0xf700,	0xf200,	0xf01a,	0xf018,	0xf003,	0xf016,
+	0xf002,	0xf00e,	0xf00d,	0xf200,	0xf200,	0xf200,	0xf700,	0xf30c,
+	0xf703,	0xf200,	0xf207,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf208,	0xf200,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+static unsigned short alt_map[NR_KEYS] = {
+	0xf200,	0xf81b,	0xf831,	0xf832,	0xf833,	0xf834,	0xf835,	0xf836,
+	0xf837,	0xf838,	0xf839,	0xf830,	0xf82d,	0xf83d,	0xf87f,	0xf809,
+	0xf871,	0xf877,	0xf865,	0xf872,	0xf874,	0xf879,	0xf875,	0xf869,
+	0xf86f,	0xf870,	0xf85b,	0xf85d,	0xf80d,	0xf702,	0xf861,	0xf873,
+	0xf864,	0xf866,	0xf867,	0xf868,	0xf86a,	0xf86b,	0xf86c,	0xf83b,
+	0xf827,	0xf860,	0xf700,	0xf85c,	0xf87a,	0xf878,	0xf863,	0xf876,
+	0xf862,	0xf86e,	0xf86d,	0xf82c,	0xf82e,	0xf82f,	0xf700,	0xf30c,
+	0xf703,	0xf820,	0xf207,	0xf500,	0xf501,	0xf502,	0xf503,	0xf504,
+	0xf505,	0xf506,	0xf507,	0xf508,	0xf509,	0xf208,	0xf209,	0xf907,
+	0xf908,	0xf909,	0xf30b,	0xf904,	0xf905,	0xf906,	0xf30a,	0xf901,
+	0xf902,	0xf903,	0xf900,	0xf310,	0xf206,	0xf200,	0xf83c,	0xf50a,
+	0xf50b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf01c,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf210,	0xf211,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+static unsigned short ctrl_alt_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf811,	0xf817,	0xf805,	0xf812,	0xf814,	0xf819,	0xf815,	0xf809,
+	0xf80f,	0xf810,	0xf200,	0xf200,	0xf201,	0xf702,	0xf801,	0xf813,
+	0xf804,	0xf806,	0xf807,	0xf808,	0xf80a,	0xf80b,	0xf80c,	0xf200,
+	0xf200,	0xf200,	0xf700,	0xf200,	0xf81a,	0xf818,	0xf803,	0xf816,
+	0xf802,	0xf80e,	0xf80d,	0xf200,	0xf200,	0xf200,	0xf700,	0xf30c,
+	0xf703,	0xf200,	0xf207,	0xf500,	0xf501,	0xf502,	0xf503,	0xf504,
+	0xf505,	0xf506,	0xf507,	0xf508,	0xf509,	0xf208,	0xf200,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf20c,	0xf206,	0xf200,	0xf200,	0xf50a,
+	0xf50b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf20c,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+unsigned short *key_maps[MAX_NR_KEYMAPS] = {
+	plain_map, shift_map, altgr_map, NULL,
+	ctrl_map, shift_ctrl_map, NULL, NULL,
+	alt_map, NULL, NULL, NULL,
+	ctrl_alt_map, NULL
+};
+
+unsigned int keymap_count = 7;
+
+/*
+ * Philosophy: most people do not define more strings, but they who do
+ * often want quite a lot of string space. So, we statically allocate
+ * the default and allocate dynamically in chunks of 512 bytes.
+ */
+
+char func_buf[] = {
+	'\033', '[', '[', 'A', 0, 
+	'\033', '[', '[', 'B', 0, 
+	'\033', '[', '[', 'C', 0, 
+	'\033', '[', '[', 'D', 0, 
+	'\033', '[', '[', 'E', 0, 
+	'\033', '[', '1', '7', '~', 0, 
+	'\033', '[', '1', '8', '~', 0, 
+	'\033', '[', '1', '9', '~', 0, 
+	'\033', '[', '2', '0', '~', 0, 
+	'\033', '[', '2', '1', '~', 0, 
+	'\033', '[', '2', '3', '~', 0, 
+	'\033', '[', '2', '4', '~', 0, 
+	'\033', '[', '2', '5', '~', 0, 
+	'\033', '[', '2', '6', '~', 0, 
+	'\033', '[', '2', '8', '~', 0, 
+	'\033', '[', '2', '9', '~', 0, 
+	'\033', '[', '3', '1', '~', 0, 
+	'\033', '[', '3', '2', '~', 0, 
+	'\033', '[', '3', '3', '~', 0, 
+	'\033', '[', '3', '4', '~', 0, 
+	'\033', '[', '1', '~', 0, 
+	'\033', '[', '2', '~', 0, 
+	'\033', '[', '3', '~', 0, 
+	'\033', '[', '4', '~', 0, 
+	'\033', '[', '5', '~', 0, 
+	'\033', '[', '6', '~', 0, 
+	'\033', '[', 'M', 0, 
+	'\033', '[', 'P', 0, 
+};
+
+char *funcbufptr = func_buf;
+int funcbufsize = sizeof(func_buf);
+int funcbufleft = 0;          /* space left */
+
+char *func_table[MAX_NR_FUNC] = {
+	func_buf + 0,
+	func_buf + 5,
+	func_buf + 10,
+	func_buf + 15,
+	func_buf + 20,
+	func_buf + 25,
+	func_buf + 31,
+	func_buf + 37,
+	func_buf + 43,
+	func_buf + 49,
+	func_buf + 55,
+	func_buf + 61,
+	func_buf + 67,
+	func_buf + 73,
+	func_buf + 79,
+	func_buf + 85,
+	func_buf + 91,
+	func_buf + 97,
+	func_buf + 103,
+	func_buf + 109,
+	func_buf + 115,
+	func_buf + 120,
+	func_buf + 125,
+	func_buf + 130,
+	func_buf + 135,
+	func_buf + 140,
+	func_buf + 145,
+	NULL,
+	NULL,
+	func_buf + 149,
+	NULL,
+};
+
+struct kbdiacruc accent_table[MAX_DIACR] = {
+	{'`', 'A', 0x00c0},	{'`', 'a', 0x00e0},
+	{'\'', 'A', 0x00c1},	{'\'', 'a', 0x00e1},
+	{'^', 'A', 0x00c2},	{'^', 'a', 0x00e2},
+	{'~', 'A', 0x00c3},	{'~', 'a', 0x00e3},
+	{'"', 'A', 0x00c4},	{'"', 'a', 0x00e4},
+	{'O', 'A', 0x00c5},	{'o', 'a', 0x00e5},
+	{'0', 'A', 0x00c5},	{'0', 'a', 0x00e5},
+	{'A', 'A', 0x00c5},	{'a', 'a', 0x00e5},
+	{'A', 'E', 0x00c6},	{'a', 'e', 0x00e6},
+	{',', 'C', 0x00c7},	{',', 'c', 0x00e7},
+	{'`', 'E', 0x00c8},	{'`', 'e', 0x00e8},
+	{'\'', 'E', 0x00c9},	{'\'', 'e', 0x00e9},
+	{'^', 'E', 0x00ca},	{'^', 'e', 0x00ea},
+	{'"', 'E', 0x00cb},	{'"', 'e', 0x00eb},
+	{'`', 'I', 0x00cc},	{'`', 'i', 0x00ec},
+	{'\'', 'I', 0x00cd},	{'\'', 'i', 0x00ed},
+	{'^', 'I', 0x00ce},	{'^', 'i', 0x00ee},
+	{'"', 'I', 0x00cf},	{'"', 'i', 0x00ef},
+	{'-', 'D', 0x00d0},	{'-', 'd', 0x00f0},
+	{'~', 'N', 0x00d1},	{'~', 'n', 0x00f1},
+	{'`', 'O', 0x00d2},	{'`', 'o', 0x00f2},
+	{'\'', 'O', 0x00d3},	{'\'', 'o', 0x00f3},
+	{'^', 'O', 0x00d4},	{'^', 'o', 0x00f4},
+	{'~', 'O', 0x00d5},	{'~', 'o', 0x00f5},
+	{'"', 'O', 0x00d6},	{'"', 'o', 0x00f6},
+	{'/', 'O', 0x00d8},	{'/', 'o', 0x00f8},
+	{'`', 'U', 0x00d9},	{'`', 'u', 0x00f9},
+	{'\'', 'U', 0x00da},	{'\'', 'u', 0x00fa},
+	{'^', 'U', 0x00db},	{'^', 'u', 0x00fb},
+	{'"', 'U', 0x00dc},	{'"', 'u', 0x00fc},
+	{'\'', 'Y', 0x00dd},	{'\'', 'y', 0x00fd},
+	{'T', 'H', 0x00de},	{'t', 'h', 0x00fe},
+	{'s', 's', 0x00df},	{'"', 'y', 0x00ff},
+	{'s', 'z', 0x00df},	{'i', 'j', 0x00ff},
+};
+
+unsigned int accent_table_size = 68;
diff --git a/drivers/tty/vt/defkeymap.map b/drivers/tty/vt/defkeymap.map
new file mode 100644
index 000000000..37f1ac6dd
--- /dev/null
+++ b/drivers/tty/vt/defkeymap.map
@@ -0,0 +1,358 @@
+# SPDX-License-Identifier: GPL-2.0
+# Default kernel keymap. This uses 7 modifier combinations.
+keymaps 0-2,4-5,8,12
+# Change the above line into
+#	keymaps 0-2,4-6,8,12
+# in case you want the entries
+#	altgr   control keycode  83 = Boot            
+#	altgr   control keycode 111 = Boot            
+# below.
+#
+# In fact AltGr is used very little, and one more keymap can
+# be saved by mapping AltGr to Alt (and adapting a few entries):
+# keycode 100 = Alt
+#
+keycode   1 = Escape           Escape          
+	alt     keycode   1 = Meta_Escape     
+keycode   2 = one              exclam          
+	alt     keycode   2 = Meta_one        
+keycode   3 = two              at               at              
+	control	keycode   3 = nul             
+	shift	control	keycode   3 = nul             
+	alt	keycode   3 = Meta_two        
+keycode   4 = three            numbersign      
+	control keycode   4 = Escape          
+	alt     keycode   4 = Meta_three      
+keycode   5 = four             dollar           dollar          
+	control keycode   5 = Control_backslash
+	alt     keycode   5 = Meta_four       
+keycode   6 = five             percent         
+	control keycode   6 = Control_bracketright
+	alt     keycode   6 = Meta_five       
+keycode   7 = six              asciicircum     
+	control keycode   7 = Control_asciicircum
+	alt     keycode   7 = Meta_six        
+keycode   8 = seven            ampersand        braceleft       
+	control keycode   8 = Control_underscore
+	alt     keycode   8 = Meta_seven      
+keycode   9 = eight            asterisk         bracketleft     
+	control keycode   9 = Delete          
+	alt     keycode   9 = Meta_eight      
+keycode  10 = nine             parenleft        bracketright    
+	alt     keycode  10 = Meta_nine       
+keycode  11 = zero             parenright       braceright      
+	alt     keycode  11 = Meta_zero       
+keycode  12 = minus            underscore       backslash       
+	control	keycode  12 = Control_underscore
+	shift	control	keycode  12 = Control_underscore
+	alt	keycode  12 = Meta_minus      
+keycode  13 = equal            plus            
+	alt     keycode  13 = Meta_equal      
+keycode  14 = Delete           Delete          
+	control keycode  14 = BackSpace
+	alt     keycode  14 = Meta_Delete     
+keycode  15 = Tab              Tab             
+	alt     keycode  15 = Meta_Tab        
+keycode  16 = q               
+keycode  17 = w               
+keycode  18 = e
+	altgr   keycode  18 = Hex_E   
+keycode  19 = r               
+keycode  20 = t               
+keycode  21 = y               
+keycode  22 = u               
+keycode  23 = i               
+keycode  24 = o               
+keycode  25 = p               
+keycode  26 = bracketleft      braceleft       
+	control keycode  26 = Escape          
+	alt     keycode  26 = Meta_bracketleft
+keycode  27 = bracketright     braceright       asciitilde      
+	control keycode  27 = Control_bracketright
+	alt     keycode  27 = Meta_bracketright
+keycode  28 = Return          
+	alt     keycode  28 = Meta_Control_m  
+keycode  29 = Control         
+keycode  30 = a
+	altgr   keycode  30 = Hex_A
+keycode  31 = s               
+keycode  32 = d
+	altgr   keycode  32 = Hex_D   
+keycode  33 = f
+	altgr   keycode  33 = Hex_F               
+keycode  34 = g               
+keycode  35 = h               
+keycode  36 = j               
+keycode  37 = k               
+keycode  38 = l               
+keycode  39 = semicolon        colon           
+	alt     keycode  39 = Meta_semicolon  
+keycode  40 = apostrophe       quotedbl        
+	control keycode  40 = Control_g       
+	alt     keycode  40 = Meta_apostrophe 
+keycode  41 = grave            asciitilde      
+	control keycode  41 = nul             
+	alt     keycode  41 = Meta_grave      
+keycode  42 = Shift           
+keycode  43 = backslash        bar             
+	control keycode  43 = Control_backslash
+	alt     keycode  43 = Meta_backslash  
+keycode  44 = z               
+keycode  45 = x               
+keycode  46 = c
+	altgr   keycode  46 = Hex_C   
+keycode  47 = v               
+keycode  48 = b
+	altgr   keycode  48 = Hex_B
+keycode  49 = n               
+keycode  50 = m               
+keycode  51 = comma            less            
+	alt     keycode  51 = Meta_comma      
+keycode  52 = period           greater         
+	control keycode  52 = Compose         
+	alt     keycode  52 = Meta_period     
+keycode  53 = slash            question        
+	control keycode  53 = Delete          
+	alt     keycode  53 = Meta_slash      
+keycode  54 = Shift           
+keycode  55 = KP_Multiply     
+keycode  56 = Alt             
+keycode  57 = space            space           
+	control keycode  57 = nul             
+	alt     keycode  57 = Meta_space      
+keycode  58 = Caps_Lock       
+keycode  59 = F1               F11              Console_13      
+	control keycode  59 = F1              
+	alt     keycode  59 = Console_1       
+	control alt     keycode  59 = Console_1       
+keycode  60 = F2               F12              Console_14      
+	control keycode  60 = F2              
+	alt     keycode  60 = Console_2       
+	control alt     keycode  60 = Console_2       
+keycode  61 = F3               F13              Console_15      
+	control keycode  61 = F3              
+	alt     keycode  61 = Console_3       
+	control alt     keycode  61 = Console_3       
+keycode  62 = F4               F14              Console_16      
+	control keycode  62 = F4              
+	alt     keycode  62 = Console_4       
+	control alt     keycode  62 = Console_4       
+keycode  63 = F5               F15              Console_17      
+	control keycode  63 = F5              
+	alt     keycode  63 = Console_5       
+	control alt     keycode  63 = Console_5       
+keycode  64 = F6               F16              Console_18      
+	control keycode  64 = F6              
+	alt     keycode  64 = Console_6       
+	control alt     keycode  64 = Console_6       
+keycode  65 = F7               F17              Console_19      
+	control keycode  65 = F7              
+	alt     keycode  65 = Console_7       
+	control alt     keycode  65 = Console_7       
+keycode  66 = F8               F18              Console_20      
+	control keycode  66 = F8              
+	alt     keycode  66 = Console_8       
+	control alt     keycode  66 = Console_8       
+keycode  67 = F9               F19              Console_21      
+	control keycode  67 = F9              
+	alt     keycode  67 = Console_9       
+	control alt     keycode  67 = Console_9       
+keycode  68 = F10              F20              Console_22      
+	control keycode  68 = F10             
+	alt     keycode  68 = Console_10      
+	control alt     keycode  68 = Console_10      
+keycode  69 = Num_Lock
+	shift   keycode  69 = Bare_Num_Lock
+keycode  70 = Scroll_Lock      Show_Memory      Show_Registers  
+	control keycode  70 = Show_State      
+	alt     keycode  70 = Scroll_Lock     
+keycode  71 = KP_7            
+	alt     keycode  71 = Ascii_7         
+	altgr   keycode  71 = Hex_7         
+keycode  72 = KP_8            
+	alt     keycode  72 = Ascii_8         
+	altgr   keycode  72 = Hex_8         
+keycode  73 = KP_9            
+	alt     keycode  73 = Ascii_9         
+	altgr   keycode  73 = Hex_9         
+keycode  74 = KP_Subtract     
+keycode  75 = KP_4            
+	alt     keycode  75 = Ascii_4         
+	altgr   keycode  75 = Hex_4         
+keycode  76 = KP_5            
+	alt     keycode  76 = Ascii_5         
+	altgr   keycode  76 = Hex_5         
+keycode  77 = KP_6            
+	alt     keycode  77 = Ascii_6         
+	altgr   keycode  77 = Hex_6         
+keycode  78 = KP_Add          
+keycode  79 = KP_1            
+	alt     keycode  79 = Ascii_1         
+	altgr   keycode  79 = Hex_1         
+keycode  80 = KP_2            
+	alt     keycode  80 = Ascii_2         
+	altgr   keycode  80 = Hex_2         
+keycode  81 = KP_3            
+	alt     keycode  81 = Ascii_3         
+	altgr   keycode  81 = Hex_3         
+keycode  82 = KP_0            
+	alt     keycode  82 = Ascii_0         
+	altgr   keycode  82 = Hex_0         
+keycode  83 = KP_Period       
+#	altgr   control keycode  83 = Boot            
+	control alt     keycode  83 = Boot            
+keycode  84 = Last_Console    
+keycode  85 =
+keycode  86 = less             greater          bar             
+	alt     keycode  86 = Meta_less       
+keycode  87 = F11              F11              Console_23      
+	control keycode  87 = F11             
+	alt     keycode  87 = Console_11      
+	control alt     keycode  87 = Console_11      
+keycode  88 = F12              F12              Console_24      
+	control keycode  88 = F12             
+	alt     keycode  88 = Console_12      
+	control alt     keycode  88 = Console_12      
+keycode  89 =
+keycode  90 =
+keycode  91 =
+keycode  92 =
+keycode  93 =
+keycode  94 =
+keycode  95 =
+keycode  96 = KP_Enter        
+keycode  97 = Control         
+keycode  98 = KP_Divide       
+keycode  99 = Control_backslash
+	control keycode  99 = Control_backslash
+	alt     keycode  99 = Control_backslash
+keycode 100 = AltGr           
+keycode 101 = Break           
+keycode 102 = Find            
+keycode 103 = Up              
+keycode 104 = Prior           
+	shift   keycode 104 = Scroll_Backward 
+keycode 105 = Left            
+	alt     keycode 105 = Decr_Console
+keycode 106 = Right           
+	alt     keycode 106 = Incr_Console
+keycode 107 = Select          
+keycode 108 = Down            
+keycode 109 = Next            
+	shift   keycode 109 = Scroll_Forward  
+keycode 110 = Insert          
+keycode 111 = Remove          
+#	altgr   control keycode 111 = Boot            
+	control alt     keycode 111 = Boot            
+keycode 112 = Macro           
+keycode 113 = F13             
+keycode 114 = F14             
+keycode 115 = Help            
+keycode 116 = Do              
+keycode 117 = F17             
+keycode 118 = KP_MinPlus      
+keycode 119 = Pause           
+keycode 120 =
+keycode 121 =
+keycode 122 =
+keycode 123 =
+keycode 124 =
+keycode 125 =
+keycode 126 =
+keycode 127 =
+string F1 = "\033[[A"
+string F2 = "\033[[B"
+string F3 = "\033[[C"
+string F4 = "\033[[D"
+string F5 = "\033[[E"
+string F6 = "\033[17~"
+string F7 = "\033[18~"
+string F8 = "\033[19~"
+string F9 = "\033[20~"
+string F10 = "\033[21~"
+string F11 = "\033[23~"
+string F12 = "\033[24~"
+string F13 = "\033[25~"
+string F14 = "\033[26~"
+string F15 = "\033[28~"
+string F16 = "\033[29~"
+string F17 = "\033[31~"
+string F18 = "\033[32~"
+string F19 = "\033[33~"
+string F20 = "\033[34~"
+string Find = "\033[1~"
+string Insert = "\033[2~"
+string Remove = "\033[3~"
+string Select = "\033[4~"
+string Prior = "\033[5~"
+string Next = "\033[6~"
+string Macro = "\033[M"
+string Pause = "\033[P"
+compose '`' 'A' to '�'
+compose '`' 'a' to '�'
+compose '\'' 'A' to '�'
+compose '\'' 'a' to '�'
+compose '^' 'A' to '�'
+compose '^' 'a' to '�'
+compose '~' 'A' to '�'
+compose '~' 'a' to '�'
+compose '"' 'A' to '�'
+compose '"' 'a' to '�'
+compose 'O' 'A' to '�'
+compose 'o' 'a' to '�'
+compose '0' 'A' to '�'
+compose '0' 'a' to '�'
+compose 'A' 'A' to '�'
+compose 'a' 'a' to '�'
+compose 'A' 'E' to '�'
+compose 'a' 'e' to '�'
+compose ',' 'C' to '�'
+compose ',' 'c' to '�'
+compose '`' 'E' to '�'
+compose '`' 'e' to '�'
+compose '\'' 'E' to '�'
+compose '\'' 'e' to '�'
+compose '^' 'E' to '�'
+compose '^' 'e' to '�'
+compose '"' 'E' to '�'
+compose '"' 'e' to '�'
+compose '`' 'I' to '�'
+compose '`' 'i' to '�'
+compose '\'' 'I' to '�'
+compose '\'' 'i' to '�'
+compose '^' 'I' to '�'
+compose '^' 'i' to '�'
+compose '"' 'I' to '�'
+compose '"' 'i' to '�'
+compose '-' 'D' to '�'
+compose '-' 'd' to '�'
+compose '~' 'N' to '�'
+compose '~' 'n' to '�'
+compose '`' 'O' to '�'
+compose '`' 'o' to '�'
+compose '\'' 'O' to '�'
+compose '\'' 'o' to '�'
+compose '^' 'O' to '�'
+compose '^' 'o' to '�'
+compose '~' 'O' to '�'
+compose '~' 'o' to '�'
+compose '"' 'O' to '�'
+compose '"' 'o' to '�'
+compose '/' 'O' to '�'
+compose '/' 'o' to '�'
+compose '`' 'U' to '�'
+compose '`' 'u' to '�'
+compose '\'' 'U' to '�'
+compose '\'' 'u' to '�'
+compose '^' 'U' to '�'
+compose '^' 'u' to '�'
+compose '"' 'U' to '�'
+compose '"' 'u' to '�'
+compose '\'' 'Y' to '�'
+compose '\'' 'y' to '�'
+compose 'T' 'H' to '�'
+compose 't' 'h' to '�'
+compose 's' 's' to '�'
+compose '"' 'y' to '�'
+compose 's' 'z' to '�'
+compose 'i' 'j' to '�'
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
new file mode 100644
index 000000000..358f216c6
--- /dev/null
+++ b/drivers/tty/vt/keyboard.c
@@ -0,0 +1,2291 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Written for linux by Johan Myreen as a translation from
+ * the assembly version by Linus (with diacriticals added)
+ *
+ * Some additional features added by Christoph Niemann (ChN), March 1993
+ *
+ * Loadable keymaps by Risto Kankkunen, May 1993
+ *
+ * Diacriticals redone & other small changes, aeb@cwi.nl, June 1993
+ * Added decr/incr_console, dynamic keymaps, Unicode support,
+ * dynamic function/string keys, led setting,  Sept 1994
+ * `Sticky' modifier keys, 951006.
+ *
+ * 11-11-96: SAK should now work in the raw mode (Martin Mares)
+ *
+ * Modified to provide 'generic' keyboard support by Hamish Macdonald
+ * Merge with the m68k keyboard driver and split-off of the PC low-level
+ * parts by Geert Uytterhoeven, May 1997
+ *
+ * 27-05-97: Added support for the Magic SysRq Key (Martin Mares)
+ * 30-07-98: Dead keys redone, aeb@cwi.nl.
+ * 21-08-02: Converted to input API, major cleanup. (Vojtech Pavlik)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/consolemap.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/jiffies.h>
+#include <linux/kbd_diacr.h>
+#include <linux/kbd_kern.h>
+#include <linux/leds.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/nospec.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/tty_flip.h>
+#include <linux/tty.h>
+#include <linux/uaccess.h>
+#include <linux/vt_kern.h>
+
+#include <asm/irq_regs.h>
+
+/*
+ * Exported functions/variables
+ */
+
+#define KBD_DEFMODE (BIT(VC_REPEAT) | BIT(VC_META))
+
+#if defined(CONFIG_X86) || defined(CONFIG_PARISC)
+#include <asm/kbdleds.h>
+#else
+static inline int kbd_defleds(void)
+{
+	return 0;
+}
+#endif
+
+#define KBD_DEFLOCK 0
+
+/*
+ * Handler Tables.
+ */
+
+#define K_HANDLERS\
+	k_self,		k_fn,		k_spec,		k_pad,\
+	k_dead,		k_cons,		k_cur,		k_shift,\
+	k_meta,		k_ascii,	k_lock,		k_lowercase,\
+	k_slock,	k_dead2,	k_brl,		k_ignore
+
+typedef void (k_handler_fn)(struct vc_data *vc, unsigned char value,
+			    char up_flag);
+static k_handler_fn K_HANDLERS;
+static k_handler_fn *k_handler[16] = { K_HANDLERS };
+
+#define FN_HANDLERS\
+	fn_null,	fn_enter,	fn_show_ptregs,	fn_show_mem,\
+	fn_show_state,	fn_send_intr,	fn_lastcons,	fn_caps_toggle,\
+	fn_num,		fn_hold,	fn_scroll_forw,	fn_scroll_back,\
+	fn_boot_it,	fn_caps_on,	fn_compose,	fn_SAK,\
+	fn_dec_console, fn_inc_console, fn_spawn_con,	fn_bare_num
+
+typedef void (fn_handler_fn)(struct vc_data *vc);
+static fn_handler_fn FN_HANDLERS;
+static fn_handler_fn *fn_handler[] = { FN_HANDLERS };
+
+/*
+ * Variables exported for vt_ioctl.c
+ */
+
+struct vt_spawn_console vt_spawn_con = {
+	.lock = __SPIN_LOCK_UNLOCKED(vt_spawn_con.lock),
+	.pid  = NULL,
+	.sig  = 0,
+};
+
+
+/*
+ * Internal Data.
+ */
+
+static struct kbd_struct kbd_table[MAX_NR_CONSOLES];
+static struct kbd_struct *kbd = kbd_table;
+
+/* maximum values each key_handler can handle */
+static const unsigned char max_vals[] = {
+	[ KT_LATIN	] = 255,
+	[ KT_FN		] = ARRAY_SIZE(func_table) - 1,
+	[ KT_SPEC	] = ARRAY_SIZE(fn_handler) - 1,
+	[ KT_PAD	] = NR_PAD - 1,
+	[ KT_DEAD	] = NR_DEAD - 1,
+	[ KT_CONS	] = 255,
+	[ KT_CUR	] = 3,
+	[ KT_SHIFT	] = NR_SHIFT - 1,
+	[ KT_META	] = 255,
+	[ KT_ASCII	] = NR_ASCII - 1,
+	[ KT_LOCK	] = NR_LOCK - 1,
+	[ KT_LETTER	] = 255,
+	[ KT_SLOCK	] = NR_LOCK - 1,
+	[ KT_DEAD2	] = 255,
+	[ KT_BRL	] = NR_BRL - 1,
+};
+
+static const int NR_TYPES = ARRAY_SIZE(max_vals);
+
+static void kbd_bh(struct tasklet_struct *unused);
+static DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh);
+
+static struct input_handler kbd_handler;
+static DEFINE_SPINLOCK(kbd_event_lock);
+static DEFINE_SPINLOCK(led_lock);
+static DEFINE_SPINLOCK(func_buf_lock); /* guard 'func_buf'  and friends */
+static DECLARE_BITMAP(key_down, KEY_CNT);	/* keyboard key bitmap */
+static unsigned char shift_down[NR_SHIFT];		/* shift state counters.. */
+static bool dead_key_next;
+
+/* Handles a number being assembled on the number pad */
+static bool npadch_active;
+static unsigned int npadch_value;
+
+static unsigned int diacr;
+static bool rep;			/* flag telling character repeat */
+
+static int shift_state = 0;
+
+static unsigned int ledstate = -1U;			/* undefined */
+static unsigned char ledioctl;
+static bool vt_switch;
+
+/*
+ * Notifier list for console keyboard events
+ */
+static ATOMIC_NOTIFIER_HEAD(keyboard_notifier_list);
+
+int register_keyboard_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&keyboard_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_keyboard_notifier);
+
+int unregister_keyboard_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&keyboard_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_keyboard_notifier);
+
+/*
+ * Translation of scancodes to keycodes. We set them on only the first
+ * keyboard in the list that accepts the scancode and keycode.
+ * Explanation for not choosing the first attached keyboard anymore:
+ *  USB keyboards for example have two event devices: one for all "normal"
+ *  keys and one for extra function keys (like "volume up", "make coffee",
+ *  etc.). So this means that scancodes for the extra function keys won't
+ *  be valid for the first event device, but will be for the second.
+ */
+
+struct getset_keycode_data {
+	struct input_keymap_entry ke;
+	int error;
+};
+
+static int getkeycode_helper(struct input_handle *handle, void *data)
+{
+	struct getset_keycode_data *d = data;
+
+	d->error = input_get_keycode(handle->dev, &d->ke);
+
+	return d->error == 0; /* stop as soon as we successfully get one */
+}
+
+static int getkeycode(unsigned int scancode)
+{
+	struct getset_keycode_data d = {
+		.ke	= {
+			.flags		= 0,
+			.len		= sizeof(scancode),
+			.keycode	= 0,
+		},
+		.error	= -ENODEV,
+	};
+
+	memcpy(d.ke.scancode, &scancode, sizeof(scancode));
+
+	input_handler_for_each_handle(&kbd_handler, &d, getkeycode_helper);
+
+	return d.error ?: d.ke.keycode;
+}
+
+static int setkeycode_helper(struct input_handle *handle, void *data)
+{
+	struct getset_keycode_data *d = data;
+
+	d->error = input_set_keycode(handle->dev, &d->ke);
+
+	return d->error == 0; /* stop as soon as we successfully set one */
+}
+
+static int setkeycode(unsigned int scancode, unsigned int keycode)
+{
+	struct getset_keycode_data d = {
+		.ke	= {
+			.flags		= 0,
+			.len		= sizeof(scancode),
+			.keycode	= keycode,
+		},
+		.error	= -ENODEV,
+	};
+
+	memcpy(d.ke.scancode, &scancode, sizeof(scancode));
+
+	input_handler_for_each_handle(&kbd_handler, &d, setkeycode_helper);
+
+	return d.error;
+}
+
+/*
+ * Making beeps and bells. Note that we prefer beeps to bells, but when
+ * shutting the sound off we do both.
+ */
+
+static int kd_sound_helper(struct input_handle *handle, void *data)
+{
+	unsigned int *hz = data;
+	struct input_dev *dev = handle->dev;
+
+	if (test_bit(EV_SND, dev->evbit)) {
+		if (test_bit(SND_TONE, dev->sndbit)) {
+			input_inject_event(handle, EV_SND, SND_TONE, *hz);
+			if (*hz)
+				return 0;
+		}
+		if (test_bit(SND_BELL, dev->sndbit))
+			input_inject_event(handle, EV_SND, SND_BELL, *hz ? 1 : 0);
+	}
+
+	return 0;
+}
+
+static void kd_nosound(struct timer_list *unused)
+{
+	static unsigned int zero;
+
+	input_handler_for_each_handle(&kbd_handler, &zero, kd_sound_helper);
+}
+
+static DEFINE_TIMER(kd_mksound_timer, kd_nosound);
+
+void kd_mksound(unsigned int hz, unsigned int ticks)
+{
+	del_timer_sync(&kd_mksound_timer);
+
+	input_handler_for_each_handle(&kbd_handler, &hz, kd_sound_helper);
+
+	if (hz && ticks)
+		mod_timer(&kd_mksound_timer, jiffies + ticks);
+}
+EXPORT_SYMBOL(kd_mksound);
+
+/*
+ * Setting the keyboard rate.
+ */
+
+static int kbd_rate_helper(struct input_handle *handle, void *data)
+{
+	struct input_dev *dev = handle->dev;
+	struct kbd_repeat *rpt = data;
+
+	if (test_bit(EV_REP, dev->evbit)) {
+
+		if (rpt[0].delay > 0)
+			input_inject_event(handle,
+					   EV_REP, REP_DELAY, rpt[0].delay);
+		if (rpt[0].period > 0)
+			input_inject_event(handle,
+					   EV_REP, REP_PERIOD, rpt[0].period);
+
+		rpt[1].delay = dev->rep[REP_DELAY];
+		rpt[1].period = dev->rep[REP_PERIOD];
+	}
+
+	return 0;
+}
+
+int kbd_rate(struct kbd_repeat *rpt)
+{
+	struct kbd_repeat data[2] = { *rpt };
+
+	input_handler_for_each_handle(&kbd_handler, data, kbd_rate_helper);
+	*rpt = data[1];	/* Copy currently used settings */
+
+	return 0;
+}
+
+/*
+ * Helper Functions.
+ */
+static void put_queue(struct vc_data *vc, int ch)
+{
+	tty_insert_flip_char(&vc->port, ch, 0);
+	tty_flip_buffer_push(&vc->port);
+}
+
+static void puts_queue(struct vc_data *vc, const char *cp)
+{
+	tty_insert_flip_string(&vc->port, cp, strlen(cp));
+	tty_flip_buffer_push(&vc->port);
+}
+
+static void applkey(struct vc_data *vc, int key, char mode)
+{
+	static char buf[] = { 0x1b, 'O', 0x00, 0x00 };
+
+	buf[1] = (mode ? 'O' : '[');
+	buf[2] = key;
+	puts_queue(vc, buf);
+}
+
+/*
+ * Many other routines do put_queue, but I think either
+ * they produce ASCII, or they produce some user-assigned
+ * string, and in both cases we might assume that it is
+ * in utf-8 already.
+ */
+static void to_utf8(struct vc_data *vc, uint c)
+{
+	if (c < 0x80)
+		/*  0******* */
+		put_queue(vc, c);
+	else if (c < 0x800) {
+		/* 110***** 10****** */
+		put_queue(vc, 0xc0 | (c >> 6));
+		put_queue(vc, 0x80 | (c & 0x3f));
+	} else if (c < 0x10000) {
+		if (c >= 0xD800 && c < 0xE000)
+			return;
+		if (c == 0xFFFF)
+			return;
+		/* 1110**** 10****** 10****** */
+		put_queue(vc, 0xe0 | (c >> 12));
+		put_queue(vc, 0x80 | ((c >> 6) & 0x3f));
+		put_queue(vc, 0x80 | (c & 0x3f));
+	} else if (c < 0x110000) {
+		/* 11110*** 10****** 10****** 10****** */
+		put_queue(vc, 0xf0 | (c >> 18));
+		put_queue(vc, 0x80 | ((c >> 12) & 0x3f));
+		put_queue(vc, 0x80 | ((c >> 6) & 0x3f));
+		put_queue(vc, 0x80 | (c & 0x3f));
+	}
+}
+
+/* FIXME: review locking for vt.c callers */
+static void set_leds(void)
+{
+	tasklet_schedule(&keyboard_tasklet);
+}
+
+/*
+ * Called after returning from RAW mode or when changing consoles - recompute
+ * shift_down[] and shift_state from key_down[] maybe called when keymap is
+ * undefined, so that shiftkey release is seen. The caller must hold the
+ * kbd_event_lock.
+ */
+
+static void do_compute_shiftstate(void)
+{
+	unsigned int k, sym, val;
+
+	shift_state = 0;
+	memset(shift_down, 0, sizeof(shift_down));
+
+	for_each_set_bit(k, key_down, min(NR_KEYS, KEY_CNT)) {
+		sym = U(key_maps[0][k]);
+		if (KTYP(sym) != KT_SHIFT && KTYP(sym) != KT_SLOCK)
+			continue;
+
+		val = KVAL(sym);
+		if (val == KVAL(K_CAPSSHIFT))
+			val = KVAL(K_SHIFT);
+
+		shift_down[val]++;
+		shift_state |= BIT(val);
+	}
+}
+
+/* We still have to export this method to vt.c */
+void vt_set_leds_compute_shiftstate(void)
+{
+	unsigned long flags;
+
+	/*
+	 * When VT is switched, the keyboard led needs to be set once.
+	 * Ensure that after the switch is completed, the state of the
+	 * keyboard LED is consistent with the state of the keyboard lock.
+	 */
+	vt_switch = true;
+	set_leds();
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	do_compute_shiftstate();
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+}
+
+/*
+ * We have a combining character DIACR here, followed by the character CH.
+ * If the combination occurs in the table, return the corresponding value.
+ * Otherwise, if CH is a space or equals DIACR, return DIACR.
+ * Otherwise, conclude that DIACR was not combining after all,
+ * queue it and return CH.
+ */
+static unsigned int handle_diacr(struct vc_data *vc, unsigned int ch)
+{
+	unsigned int d = diacr;
+	unsigned int i;
+
+	diacr = 0;
+
+	if ((d & ~0xff) == BRL_UC_ROW) {
+		if ((ch & ~0xff) == BRL_UC_ROW)
+			return d | ch;
+	} else {
+		for (i = 0; i < accent_table_size; i++)
+			if (accent_table[i].diacr == d && accent_table[i].base == ch)
+				return accent_table[i].result;
+	}
+
+	if (ch == ' ' || ch == (BRL_UC_ROW|0) || ch == d)
+		return d;
+
+	if (kbd->kbdmode == VC_UNICODE)
+		to_utf8(vc, d);
+	else {
+		int c = conv_uni_to_8bit(d);
+		if (c != -1)
+			put_queue(vc, c);
+	}
+
+	return ch;
+}
+
+/*
+ * Special function handlers
+ */
+static void fn_enter(struct vc_data *vc)
+{
+	if (diacr) {
+		if (kbd->kbdmode == VC_UNICODE)
+			to_utf8(vc, diacr);
+		else {
+			int c = conv_uni_to_8bit(diacr);
+			if (c != -1)
+				put_queue(vc, c);
+		}
+		diacr = 0;
+	}
+
+	put_queue(vc, '\r');
+	if (vc_kbd_mode(kbd, VC_CRLF))
+		put_queue(vc, '\n');
+}
+
+static void fn_caps_toggle(struct vc_data *vc)
+{
+	if (rep)
+		return;
+
+	chg_vc_kbd_led(kbd, VC_CAPSLOCK);
+}
+
+static void fn_caps_on(struct vc_data *vc)
+{
+	if (rep)
+		return;
+
+	set_vc_kbd_led(kbd, VC_CAPSLOCK);
+}
+
+static void fn_show_ptregs(struct vc_data *vc)
+{
+	struct pt_regs *regs = get_irq_regs();
+
+	if (regs)
+		show_regs(regs);
+}
+
+static void fn_hold(struct vc_data *vc)
+{
+	struct tty_struct *tty = vc->port.tty;
+
+	if (rep || !tty)
+		return;
+
+	/*
+	 * Note: SCROLLOCK will be set (cleared) by stop_tty (start_tty);
+	 * these routines are also activated by ^S/^Q.
+	 * (And SCROLLOCK can also be set by the ioctl KDSKBLED.)
+	 */
+	if (tty->flow.stopped)
+		start_tty(tty);
+	else
+		stop_tty(tty);
+}
+
+static void fn_num(struct vc_data *vc)
+{
+	if (vc_kbd_mode(kbd, VC_APPLIC))
+		applkey(vc, 'P', 1);
+	else
+		fn_bare_num(vc);
+}
+
+/*
+ * Bind this to Shift-NumLock if you work in application keypad mode
+ * but want to be able to change the NumLock flag.
+ * Bind this to NumLock if you prefer that the NumLock key always
+ * changes the NumLock flag.
+ */
+static void fn_bare_num(struct vc_data *vc)
+{
+	if (!rep)
+		chg_vc_kbd_led(kbd, VC_NUMLOCK);
+}
+
+static void fn_lastcons(struct vc_data *vc)
+{
+	/* switch to the last used console, ChN */
+	set_console(last_console);
+}
+
+static void fn_dec_console(struct vc_data *vc)
+{
+	int i, cur = fg_console;
+
+	/* Currently switching?  Queue this next switch relative to that. */
+	if (want_console != -1)
+		cur = want_console;
+
+	for (i = cur - 1; i != cur; i--) {
+		if (i == -1)
+			i = MAX_NR_CONSOLES - 1;
+		if (vc_cons_allocated(i))
+			break;
+	}
+	set_console(i);
+}
+
+static void fn_inc_console(struct vc_data *vc)
+{
+	int i, cur = fg_console;
+
+	/* Currently switching?  Queue this next switch relative to that. */
+	if (want_console != -1)
+		cur = want_console;
+
+	for (i = cur+1; i != cur; i++) {
+		if (i == MAX_NR_CONSOLES)
+			i = 0;
+		if (vc_cons_allocated(i))
+			break;
+	}
+	set_console(i);
+}
+
+static void fn_send_intr(struct vc_data *vc)
+{
+	tty_insert_flip_char(&vc->port, 0, TTY_BREAK);
+	tty_flip_buffer_push(&vc->port);
+}
+
+static void fn_scroll_forw(struct vc_data *vc)
+{
+	scrollfront(vc, 0);
+}
+
+static void fn_scroll_back(struct vc_data *vc)
+{
+	scrollback(vc);
+}
+
+static void fn_show_mem(struct vc_data *vc)
+{
+	show_mem();
+}
+
+static void fn_show_state(struct vc_data *vc)
+{
+	show_state();
+}
+
+static void fn_boot_it(struct vc_data *vc)
+{
+	ctrl_alt_del();
+}
+
+static void fn_compose(struct vc_data *vc)
+{
+	dead_key_next = true;
+}
+
+static void fn_spawn_con(struct vc_data *vc)
+{
+	spin_lock(&vt_spawn_con.lock);
+	if (vt_spawn_con.pid)
+		if (kill_pid(vt_spawn_con.pid, vt_spawn_con.sig, 1)) {
+			put_pid(vt_spawn_con.pid);
+			vt_spawn_con.pid = NULL;
+		}
+	spin_unlock(&vt_spawn_con.lock);
+}
+
+static void fn_SAK(struct vc_data *vc)
+{
+	struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+	schedule_work(SAK_work);
+}
+
+static void fn_null(struct vc_data *vc)
+{
+	do_compute_shiftstate();
+}
+
+/*
+ * Special key handlers
+ */
+static void k_ignore(struct vc_data *vc, unsigned char value, char up_flag)
+{
+}
+
+static void k_spec(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+	if (value >= ARRAY_SIZE(fn_handler))
+		return;
+	if ((kbd->kbdmode == VC_RAW ||
+	     kbd->kbdmode == VC_MEDIUMRAW ||
+	     kbd->kbdmode == VC_OFF) &&
+	     value != KVAL(K_SAK))
+		return;		/* SAK is allowed even in raw mode */
+	fn_handler[value](vc);
+}
+
+static void k_lowercase(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	pr_err("k_lowercase was called - impossible\n");
+}
+
+static void k_unicode(struct vc_data *vc, unsigned int value, char up_flag)
+{
+	if (up_flag)
+		return;		/* no action, if this is a key release */
+
+	if (diacr)
+		value = handle_diacr(vc, value);
+
+	if (dead_key_next) {
+		dead_key_next = false;
+		diacr = value;
+		return;
+	}
+	if (kbd->kbdmode == VC_UNICODE)
+		to_utf8(vc, value);
+	else {
+		int c = conv_uni_to_8bit(value);
+		if (c != -1)
+			put_queue(vc, c);
+	}
+}
+
+/*
+ * Handle dead key. Note that we now may have several
+ * dead keys modifying the same character. Very useful
+ * for Vietnamese.
+ */
+static void k_deadunicode(struct vc_data *vc, unsigned int value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	diacr = (diacr ? handle_diacr(vc, value) : value);
+}
+
+static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	k_unicode(vc, conv_8bit_to_uni(value), up_flag);
+}
+
+static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	k_deadunicode(vc, value, up_flag);
+}
+
+/*
+ * Obsolete - for backwards compatibility only
+ */
+static void k_dead(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static const unsigned char ret_diacr[NR_DEAD] = {
+		'`',	/* dead_grave */
+		'\'',	/* dead_acute */
+		'^',	/* dead_circumflex */
+		'~',	/* dead_tilda */
+		'"',	/* dead_diaeresis */
+		',',	/* dead_cedilla */
+		'_',	/* dead_macron */
+		'U',	/* dead_breve */
+		'.',	/* dead_abovedot */
+		'*',	/* dead_abovering */
+		'=',	/* dead_doubleacute */
+		'c',	/* dead_caron */
+		'k',	/* dead_ogonek */
+		'i',	/* dead_iota */
+		'#',	/* dead_voiced_sound */
+		'o',	/* dead_semivoiced_sound */
+		'!',	/* dead_belowdot */
+		'?',	/* dead_hook */
+		'+',	/* dead_horn */
+		'-',	/* dead_stroke */
+		')',	/* dead_abovecomma */
+		'(',	/* dead_abovereversedcomma */
+		':',	/* dead_doublegrave */
+		'n',	/* dead_invertedbreve */
+		';',	/* dead_belowcomma */
+		'$',	/* dead_currency */
+		'@',	/* dead_greek */
+	};
+
+	k_deadunicode(vc, ret_diacr[value], up_flag);
+}
+
+static void k_cons(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	set_console(value);
+}
+
+static void k_fn(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	if ((unsigned)value < ARRAY_SIZE(func_table)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&func_buf_lock, flags);
+		if (func_table[value])
+			puts_queue(vc, func_table[value]);
+		spin_unlock_irqrestore(&func_buf_lock, flags);
+
+	} else
+		pr_err("k_fn called with value=%d\n", value);
+}
+
+static void k_cur(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static const char cur_chars[] = "BDCA";
+
+	if (up_flag)
+		return;
+
+	applkey(vc, cur_chars[value], vc_kbd_mode(kbd, VC_CKMODE));
+}
+
+static void k_pad(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static const char pad_chars[] = "0123456789+-*/\015,.?()#";
+	static const char app_map[] = "pqrstuvwxylSRQMnnmPQS";
+
+	if (up_flag)
+		return;		/* no action, if this is a key release */
+
+	/* kludge... shift forces cursor/number keys */
+	if (vc_kbd_mode(kbd, VC_APPLIC) && !shift_down[KG_SHIFT]) {
+		applkey(vc, app_map[value], 1);
+		return;
+	}
+
+	if (!vc_kbd_led(kbd, VC_NUMLOCK)) {
+
+		switch (value) {
+		case KVAL(K_PCOMMA):
+		case KVAL(K_PDOT):
+			k_fn(vc, KVAL(K_REMOVE), 0);
+			return;
+		case KVAL(K_P0):
+			k_fn(vc, KVAL(K_INSERT), 0);
+			return;
+		case KVAL(K_P1):
+			k_fn(vc, KVAL(K_SELECT), 0);
+			return;
+		case KVAL(K_P2):
+			k_cur(vc, KVAL(K_DOWN), 0);
+			return;
+		case KVAL(K_P3):
+			k_fn(vc, KVAL(K_PGDN), 0);
+			return;
+		case KVAL(K_P4):
+			k_cur(vc, KVAL(K_LEFT), 0);
+			return;
+		case KVAL(K_P6):
+			k_cur(vc, KVAL(K_RIGHT), 0);
+			return;
+		case KVAL(K_P7):
+			k_fn(vc, KVAL(K_FIND), 0);
+			return;
+		case KVAL(K_P8):
+			k_cur(vc, KVAL(K_UP), 0);
+			return;
+		case KVAL(K_P9):
+			k_fn(vc, KVAL(K_PGUP), 0);
+			return;
+		case KVAL(K_P5):
+			applkey(vc, 'G', vc_kbd_mode(kbd, VC_APPLIC));
+			return;
+		}
+	}
+
+	put_queue(vc, pad_chars[value]);
+	if (value == KVAL(K_PENTER) && vc_kbd_mode(kbd, VC_CRLF))
+		put_queue(vc, '\n');
+}
+
+static void k_shift(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	int old_state = shift_state;
+
+	if (rep)
+		return;
+	/*
+	 * Mimic typewriter:
+	 * a CapsShift key acts like Shift but undoes CapsLock
+	 */
+	if (value == KVAL(K_CAPSSHIFT)) {
+		value = KVAL(K_SHIFT);
+		if (!up_flag)
+			clr_vc_kbd_led(kbd, VC_CAPSLOCK);
+	}
+
+	if (up_flag) {
+		/*
+		 * handle the case that two shift or control
+		 * keys are depressed simultaneously
+		 */
+		if (shift_down[value])
+			shift_down[value]--;
+	} else
+		shift_down[value]++;
+
+	if (shift_down[value])
+		shift_state |= BIT(value);
+	else
+		shift_state &= ~BIT(value);
+
+	/* kludge */
+	if (up_flag && shift_state != old_state && npadch_active) {
+		if (kbd->kbdmode == VC_UNICODE)
+			to_utf8(vc, npadch_value);
+		else
+			put_queue(vc, npadch_value & 0xff);
+		npadch_active = false;
+	}
+}
+
+static void k_meta(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	if (vc_kbd_mode(kbd, VC_META)) {
+		put_queue(vc, '\033');
+		put_queue(vc, value);
+	} else
+		put_queue(vc, value | BIT(7));
+}
+
+static void k_ascii(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	unsigned int base;
+
+	if (up_flag)
+		return;
+
+	if (value < 10) {
+		/* decimal input of code, while Alt depressed */
+		base = 10;
+	} else {
+		/* hexadecimal input of code, while AltGr depressed */
+		value -= 10;
+		base = 16;
+	}
+
+	if (!npadch_active) {
+		npadch_value = 0;
+		npadch_active = true;
+	}
+
+	npadch_value = npadch_value * base + value;
+}
+
+static void k_lock(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag || rep)
+		return;
+
+	chg_vc_kbd_lock(kbd, value);
+}
+
+static void k_slock(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	k_shift(vc, value, up_flag);
+	if (up_flag || rep)
+		return;
+
+	chg_vc_kbd_slock(kbd, value);
+	/* try to make Alt, oops, AltGr and such work */
+	if (!key_maps[kbd->lockstate ^ kbd->slockstate]) {
+		kbd->slockstate = 0;
+		chg_vc_kbd_slock(kbd, value);
+	}
+}
+
+/* by default, 300ms interval for combination release */
+static unsigned brl_timeout = 300;
+MODULE_PARM_DESC(brl_timeout, "Braille keys release delay in ms (0 for commit on first key release)");
+module_param(brl_timeout, uint, 0644);
+
+static unsigned brl_nbchords = 1;
+MODULE_PARM_DESC(brl_nbchords, "Number of chords that produce a braille pattern (0 for dead chords)");
+module_param(brl_nbchords, uint, 0644);
+
+static void k_brlcommit(struct vc_data *vc, unsigned int pattern, char up_flag)
+{
+	static unsigned long chords;
+	static unsigned committed;
+
+	if (!brl_nbchords)
+		k_deadunicode(vc, BRL_UC_ROW | pattern, up_flag);
+	else {
+		committed |= pattern;
+		chords++;
+		if (chords == brl_nbchords) {
+			k_unicode(vc, BRL_UC_ROW | committed, up_flag);
+			chords = 0;
+			committed = 0;
+		}
+	}
+}
+
+static void k_brl(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static unsigned pressed, committing;
+	static unsigned long releasestart;
+
+	if (kbd->kbdmode != VC_UNICODE) {
+		if (!up_flag)
+			pr_warn("keyboard mode must be unicode for braille patterns\n");
+		return;
+	}
+
+	if (!value) {
+		k_unicode(vc, BRL_UC_ROW, up_flag);
+		return;
+	}
+
+	if (value > 8)
+		return;
+
+	if (!up_flag) {
+		pressed |= BIT(value - 1);
+		if (!brl_timeout)
+			committing = pressed;
+	} else if (brl_timeout) {
+		if (!committing ||
+		    time_after(jiffies,
+			       releasestart + msecs_to_jiffies(brl_timeout))) {
+			committing = pressed;
+			releasestart = jiffies;
+		}
+		pressed &= ~BIT(value - 1);
+		if (!pressed && committing) {
+			k_brlcommit(vc, committing, 0);
+			committing = 0;
+		}
+	} else {
+		if (committing) {
+			k_brlcommit(vc, committing, 0);
+			committing = 0;
+		}
+		pressed &= ~BIT(value - 1);
+	}
+}
+
+#if IS_ENABLED(CONFIG_INPUT_LEDS) && IS_ENABLED(CONFIG_LEDS_TRIGGERS)
+
+struct kbd_led_trigger {
+	struct led_trigger trigger;
+	unsigned int mask;
+};
+
+static int kbd_led_trigger_activate(struct led_classdev *cdev)
+{
+	struct kbd_led_trigger *trigger =
+		container_of(cdev->trigger, struct kbd_led_trigger, trigger);
+
+	tasklet_disable(&keyboard_tasklet);
+	if (ledstate != -1U)
+		led_trigger_event(&trigger->trigger,
+				  ledstate & trigger->mask ?
+					LED_FULL : LED_OFF);
+	tasklet_enable(&keyboard_tasklet);
+
+	return 0;
+}
+
+#define KBD_LED_TRIGGER(_led_bit, _name) {			\
+		.trigger = {					\
+			.name = _name,				\
+			.activate = kbd_led_trigger_activate,	\
+		},						\
+		.mask	= BIT(_led_bit),			\
+	}
+
+#define KBD_LOCKSTATE_TRIGGER(_led_bit, _name)		\
+	KBD_LED_TRIGGER((_led_bit) + 8, _name)
+
+static struct kbd_led_trigger kbd_led_triggers[] = {
+	KBD_LED_TRIGGER(VC_SCROLLOCK, "kbd-scrolllock"),
+	KBD_LED_TRIGGER(VC_NUMLOCK,   "kbd-numlock"),
+	KBD_LED_TRIGGER(VC_CAPSLOCK,  "kbd-capslock"),
+	KBD_LED_TRIGGER(VC_KANALOCK,  "kbd-kanalock"),
+
+	KBD_LOCKSTATE_TRIGGER(VC_SHIFTLOCK,  "kbd-shiftlock"),
+	KBD_LOCKSTATE_TRIGGER(VC_ALTGRLOCK,  "kbd-altgrlock"),
+	KBD_LOCKSTATE_TRIGGER(VC_CTRLLOCK,   "kbd-ctrllock"),
+	KBD_LOCKSTATE_TRIGGER(VC_ALTLOCK,    "kbd-altlock"),
+	KBD_LOCKSTATE_TRIGGER(VC_SHIFTLLOCK, "kbd-shiftllock"),
+	KBD_LOCKSTATE_TRIGGER(VC_SHIFTRLOCK, "kbd-shiftrlock"),
+	KBD_LOCKSTATE_TRIGGER(VC_CTRLLLOCK,  "kbd-ctrlllock"),
+	KBD_LOCKSTATE_TRIGGER(VC_CTRLRLOCK,  "kbd-ctrlrlock"),
+};
+
+static void kbd_propagate_led_state(unsigned int old_state,
+				    unsigned int new_state)
+{
+	struct kbd_led_trigger *trigger;
+	unsigned int changed = old_state ^ new_state;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(kbd_led_triggers); i++) {
+		trigger = &kbd_led_triggers[i];
+
+		if (changed & trigger->mask)
+			led_trigger_event(&trigger->trigger,
+					  new_state & trigger->mask ?
+						LED_FULL : LED_OFF);
+	}
+}
+
+static int kbd_update_leds_helper(struct input_handle *handle, void *data)
+{
+	unsigned int led_state = *(unsigned int *)data;
+
+	if (test_bit(EV_LED, handle->dev->evbit))
+		kbd_propagate_led_state(~led_state, led_state);
+
+	return 0;
+}
+
+static void kbd_init_leds(void)
+{
+	int error;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(kbd_led_triggers); i++) {
+		error = led_trigger_register(&kbd_led_triggers[i].trigger);
+		if (error)
+			pr_err("error %d while registering trigger %s\n",
+			       error, kbd_led_triggers[i].trigger.name);
+	}
+}
+
+#else
+
+static int kbd_update_leds_helper(struct input_handle *handle, void *data)
+{
+	unsigned int leds = *(unsigned int *)data;
+
+	if (test_bit(EV_LED, handle->dev->evbit)) {
+		input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & BIT(0)));
+		input_inject_event(handle, EV_LED, LED_NUML,    !!(leds & BIT(1)));
+		input_inject_event(handle, EV_LED, LED_CAPSL,   !!(leds & BIT(2)));
+		input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
+	}
+
+	return 0;
+}
+
+static void kbd_propagate_led_state(unsigned int old_state,
+				    unsigned int new_state)
+{
+	input_handler_for_each_handle(&kbd_handler, &new_state,
+				      kbd_update_leds_helper);
+}
+
+static void kbd_init_leds(void)
+{
+}
+
+#endif
+
+/*
+ * The leds display either (i) the status of NumLock, CapsLock, ScrollLock,
+ * or (ii) whatever pattern of lights people want to show using KDSETLED,
+ * or (iii) specified bits of specified words in kernel memory.
+ */
+static unsigned char getledstate(void)
+{
+	return ledstate & 0xff;
+}
+
+void setledstate(struct kbd_struct *kb, unsigned int led)
+{
+        unsigned long flags;
+        spin_lock_irqsave(&led_lock, flags);
+	if (!(led & ~7)) {
+		ledioctl = led;
+		kb->ledmode = LED_SHOW_IOCTL;
+	} else
+		kb->ledmode = LED_SHOW_FLAGS;
+
+	set_leds();
+	spin_unlock_irqrestore(&led_lock, flags);
+}
+
+static inline unsigned char getleds(void)
+{
+	struct kbd_struct *kb = kbd_table + fg_console;
+
+	if (kb->ledmode == LED_SHOW_IOCTL)
+		return ledioctl;
+
+	return kb->ledflagstate;
+}
+
+/**
+ *	vt_get_leds	-	helper for braille console
+ *	@console: console to read
+ *	@flag: flag we want to check
+ *
+ *	Check the status of a keyboard led flag and report it back
+ */
+int vt_get_leds(unsigned int console, int flag)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&led_lock, flags);
+	ret = vc_kbd_led(kb, flag);
+	spin_unlock_irqrestore(&led_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vt_get_leds);
+
+/**
+ *	vt_set_led_state	-	set LED state of a console
+ *	@console: console to set
+ *	@leds: LED bits
+ *
+ *	Set the LEDs on a console. This is a wrapper for the VT layer
+ *	so that we can keep kbd knowledge internal
+ */
+void vt_set_led_state(unsigned int console, int leds)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	setledstate(kb, leds);
+}
+
+/**
+ *	vt_kbd_con_start	-	Keyboard side of console start
+ *	@console: console
+ *
+ *	Handle console start. This is a wrapper for the VT layer
+ *	so that we can keep kbd knowledge internal
+ *
+ *	FIXME: We eventually need to hold the kbd lock here to protect
+ *	the LED updating. We can't do it yet because fn_hold calls stop_tty
+ *	and start_tty under the kbd_event_lock, while normal tty paths
+ *	don't hold the lock. We probably need to split out an LED lock
+ *	but not during an -rc release!
+ */
+void vt_kbd_con_start(unsigned int console)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	unsigned long flags;
+	spin_lock_irqsave(&led_lock, flags);
+	clr_vc_kbd_led(kb, VC_SCROLLOCK);
+	set_leds();
+	spin_unlock_irqrestore(&led_lock, flags);
+}
+
+/**
+ *	vt_kbd_con_stop		-	Keyboard side of console stop
+ *	@console: console
+ *
+ *	Handle console stop. This is a wrapper for the VT layer
+ *	so that we can keep kbd knowledge internal
+ */
+void vt_kbd_con_stop(unsigned int console)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	unsigned long flags;
+	spin_lock_irqsave(&led_lock, flags);
+	set_vc_kbd_led(kb, VC_SCROLLOCK);
+	set_leds();
+	spin_unlock_irqrestore(&led_lock, flags);
+}
+
+/*
+ * This is the tasklet that updates LED state of LEDs using standard
+ * keyboard triggers. The reason we use tasklet is that we need to
+ * handle the scenario when keyboard handler is not registered yet
+ * but we already getting updates from the VT to update led state.
+ */
+static void kbd_bh(struct tasklet_struct *unused)
+{
+	unsigned int leds;
+	unsigned long flags;
+
+	spin_lock_irqsave(&led_lock, flags);
+	leds = getleds();
+	leds |= (unsigned int)kbd->lockstate << 8;
+	spin_unlock_irqrestore(&led_lock, flags);
+
+	if (vt_switch) {
+		ledstate = ~leds;
+		vt_switch = false;
+	}
+
+	if (leds != ledstate) {
+		kbd_propagate_led_state(ledstate, leds);
+		ledstate = leds;
+	}
+}
+
+#if defined(CONFIG_X86) || defined(CONFIG_IA64) || defined(CONFIG_ALPHA) ||\
+    defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) ||\
+    defined(CONFIG_PARISC) || defined(CONFIG_SUPERH) ||\
+    (defined(CONFIG_ARM) && defined(CONFIG_KEYBOARD_ATKBD) && !defined(CONFIG_ARCH_RPC))
+
+static inline bool kbd_is_hw_raw(const struct input_dev *dev)
+{
+	if (!test_bit(EV_MSC, dev->evbit) || !test_bit(MSC_RAW, dev->mscbit))
+		return false;
+
+	return dev->id.bustype == BUS_I8042 &&
+		dev->id.vendor == 0x0001 && dev->id.product == 0x0001;
+}
+
+static const unsigned short x86_keycodes[256] =
+	{ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
+	 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+	 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
+	 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
+	 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
+	 80, 81, 82, 83, 84,118, 86, 87, 88,115,120,119,121,112,123, 92,
+	284,285,309,  0,312, 91,327,328,329,331,333,335,336,337,338,339,
+	367,288,302,304,350, 89,334,326,267,126,268,269,125,347,348,349,
+	360,261,262,263,268,376,100,101,321,316,373,286,289,102,351,355,
+	103,104,105,275,287,279,258,106,274,107,294,364,358,363,362,361,
+	291,108,381,281,290,272,292,305,280, 99,112,257,306,359,113,114,
+	264,117,271,374,379,265,266, 93, 94, 95, 85,259,375,260, 90,116,
+	377,109,111,277,278,282,283,295,296,297,299,300,301,293,303,307,
+	308,310,313,314,315,317,318,319,320,357,322,323,324,325,276,330,
+	332,340,365,342,343,344,345,346,356,270,341,368,369,370,371,372 };
+
+#ifdef CONFIG_SPARC
+static int sparc_l1_a_state;
+extern void sun_do_break(void);
+#endif
+
+static int emulate_raw(struct vc_data *vc, unsigned int keycode,
+		       unsigned char up_flag)
+{
+	int code;
+
+	switch (keycode) {
+
+	case KEY_PAUSE:
+		put_queue(vc, 0xe1);
+		put_queue(vc, 0x1d | up_flag);
+		put_queue(vc, 0x45 | up_flag);
+		break;
+
+	case KEY_HANGEUL:
+		if (!up_flag)
+			put_queue(vc, 0xf2);
+		break;
+
+	case KEY_HANJA:
+		if (!up_flag)
+			put_queue(vc, 0xf1);
+		break;
+
+	case KEY_SYSRQ:
+		/*
+		 * Real AT keyboards (that's what we're trying
+		 * to emulate here) emit 0xe0 0x2a 0xe0 0x37 when
+		 * pressing PrtSc/SysRq alone, but simply 0x54
+		 * when pressing Alt+PrtSc/SysRq.
+		 */
+		if (test_bit(KEY_LEFTALT, key_down) ||
+		    test_bit(KEY_RIGHTALT, key_down)) {
+			put_queue(vc, 0x54 | up_flag);
+		} else {
+			put_queue(vc, 0xe0);
+			put_queue(vc, 0x2a | up_flag);
+			put_queue(vc, 0xe0);
+			put_queue(vc, 0x37 | up_flag);
+		}
+		break;
+
+	default:
+		if (keycode > 255)
+			return -1;
+
+		code = x86_keycodes[keycode];
+		if (!code)
+			return -1;
+
+		if (code & 0x100)
+			put_queue(vc, 0xe0);
+		put_queue(vc, (code & 0x7f) | up_flag);
+
+		break;
+	}
+
+	return 0;
+}
+
+#else
+
+static inline bool kbd_is_hw_raw(const struct input_dev *dev)
+{
+	return false;
+}
+
+static int emulate_raw(struct vc_data *vc, unsigned int keycode, unsigned char up_flag)
+{
+	if (keycode > 127)
+		return -1;
+
+	put_queue(vc, keycode | up_flag);
+	return 0;
+}
+#endif
+
+static void kbd_rawcode(unsigned char data)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+
+	kbd = &kbd_table[vc->vc_num];
+	if (kbd->kbdmode == VC_RAW)
+		put_queue(vc, data);
+}
+
+static void kbd_keycode(unsigned int keycode, int down, bool hw_raw)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	unsigned short keysym, *key_map;
+	unsigned char type;
+	bool raw_mode;
+	struct tty_struct *tty;
+	int shift_final;
+	struct keyboard_notifier_param param = { .vc = vc, .value = keycode, .down = down };
+	int rc;
+
+	tty = vc->port.tty;
+
+	if (tty && (!tty->driver_data)) {
+		/* No driver data? Strange. Okay we fix it then. */
+		tty->driver_data = vc;
+	}
+
+	kbd = &kbd_table[vc->vc_num];
+
+#ifdef CONFIG_SPARC
+	if (keycode == KEY_STOP)
+		sparc_l1_a_state = down;
+#endif
+
+	rep = (down == 2);
+
+	raw_mode = (kbd->kbdmode == VC_RAW);
+	if (raw_mode && !hw_raw)
+		if (emulate_raw(vc, keycode, !down << 7))
+			if (keycode < BTN_MISC && printk_ratelimit())
+				pr_warn("can't emulate rawmode for keycode %d\n",
+					keycode);
+
+#ifdef CONFIG_SPARC
+	if (keycode == KEY_A && sparc_l1_a_state) {
+		sparc_l1_a_state = false;
+		sun_do_break();
+	}
+#endif
+
+	if (kbd->kbdmode == VC_MEDIUMRAW) {
+		/*
+		 * This is extended medium raw mode, with keys above 127
+		 * encoded as 0, high 7 bits, low 7 bits, with the 0 bearing
+		 * the 'up' flag if needed. 0 is reserved, so this shouldn't
+		 * interfere with anything else. The two bytes after 0 will
+		 * always have the up flag set not to interfere with older
+		 * applications. This allows for 16384 different keycodes,
+		 * which should be enough.
+		 */
+		if (keycode < 128) {
+			put_queue(vc, keycode | (!down << 7));
+		} else {
+			put_queue(vc, !down << 7);
+			put_queue(vc, (keycode >> 7) | BIT(7));
+			put_queue(vc, keycode | BIT(7));
+		}
+		raw_mode = true;
+	}
+
+	assign_bit(keycode, key_down, down);
+
+	if (rep &&
+	    (!vc_kbd_mode(kbd, VC_REPEAT) ||
+	     (tty && !L_ECHO(tty) && tty_chars_in_buffer(tty)))) {
+		/*
+		 * Don't repeat a key if the input buffers are not empty and the
+		 * characters get aren't echoed locally. This makes key repeat
+		 * usable with slow applications and under heavy loads.
+		 */
+		return;
+	}
+
+	param.shift = shift_final = (shift_state | kbd->slockstate) ^ kbd->lockstate;
+	param.ledstate = kbd->ledflagstate;
+	key_map = key_maps[shift_final];
+
+	rc = atomic_notifier_call_chain(&keyboard_notifier_list,
+					KBD_KEYCODE, &param);
+	if (rc == NOTIFY_STOP || !key_map) {
+		atomic_notifier_call_chain(&keyboard_notifier_list,
+					   KBD_UNBOUND_KEYCODE, &param);
+		do_compute_shiftstate();
+		kbd->slockstate = 0;
+		return;
+	}
+
+	if (keycode < NR_KEYS)
+		keysym = key_map[keycode];
+	else if (keycode >= KEY_BRL_DOT1 && keycode <= KEY_BRL_DOT8)
+		keysym = U(K(KT_BRL, keycode - KEY_BRL_DOT1 + 1));
+	else
+		return;
+
+	type = KTYP(keysym);
+
+	if (type < 0xf0) {
+		param.value = keysym;
+		rc = atomic_notifier_call_chain(&keyboard_notifier_list,
+						KBD_UNICODE, &param);
+		if (rc != NOTIFY_STOP)
+			if (down && !raw_mode)
+				k_unicode(vc, keysym, !down);
+		return;
+	}
+
+	type -= 0xf0;
+
+	if (type == KT_LETTER) {
+		type = KT_LATIN;
+		if (vc_kbd_led(kbd, VC_CAPSLOCK)) {
+			key_map = key_maps[shift_final ^ BIT(KG_SHIFT)];
+			if (key_map)
+				keysym = key_map[keycode];
+		}
+	}
+
+	param.value = keysym;
+	rc = atomic_notifier_call_chain(&keyboard_notifier_list,
+					KBD_KEYSYM, &param);
+	if (rc == NOTIFY_STOP)
+		return;
+
+	if ((raw_mode || kbd->kbdmode == VC_OFF) && type != KT_SPEC && type != KT_SHIFT)
+		return;
+
+	(*k_handler[type])(vc, keysym & 0xff, !down);
+
+	param.ledstate = kbd->ledflagstate;
+	atomic_notifier_call_chain(&keyboard_notifier_list, KBD_POST_KEYSYM, &param);
+
+	if (type != KT_SLOCK)
+		kbd->slockstate = 0;
+}
+
+static void kbd_event(struct input_handle *handle, unsigned int event_type,
+		      unsigned int event_code, int value)
+{
+	/* We are called with interrupts disabled, just take the lock */
+	spin_lock(&kbd_event_lock);
+
+	if (event_type == EV_MSC && event_code == MSC_RAW &&
+			kbd_is_hw_raw(handle->dev))
+		kbd_rawcode(value);
+	if (event_type == EV_KEY && event_code <= KEY_MAX)
+		kbd_keycode(event_code, value, kbd_is_hw_raw(handle->dev));
+
+	spin_unlock(&kbd_event_lock);
+
+	tasklet_schedule(&keyboard_tasklet);
+	do_poke_blanked_console = 1;
+	schedule_console_callback();
+}
+
+static bool kbd_match(struct input_handler *handler, struct input_dev *dev)
+{
+	if (test_bit(EV_SND, dev->evbit))
+		return true;
+
+	if (test_bit(EV_KEY, dev->evbit)) {
+		if (find_next_bit(dev->keybit, BTN_MISC, KEY_RESERVED) <
+				BTN_MISC)
+			return true;
+		if (find_next_bit(dev->keybit, KEY_BRL_DOT10 + 1,
+					KEY_BRL_DOT1) <= KEY_BRL_DOT10)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * When a keyboard (or other input device) is found, the kbd_connect
+ * function is called. The function then looks at the device, and if it
+ * likes it, it can open it and get events from it. In this (kbd_connect)
+ * function, we should decide which VT to bind that keyboard to initially.
+ */
+static int kbd_connect(struct input_handler *handler, struct input_dev *dev,
+			const struct input_device_id *id)
+{
+	struct input_handle *handle;
+	int error;
+
+	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
+	if (!handle)
+		return -ENOMEM;
+
+	handle->dev = dev;
+	handle->handler = handler;
+	handle->name = "kbd";
+
+	error = input_register_handle(handle);
+	if (error)
+		goto err_free_handle;
+
+	error = input_open_device(handle);
+	if (error)
+		goto err_unregister_handle;
+
+	return 0;
+
+ err_unregister_handle:
+	input_unregister_handle(handle);
+ err_free_handle:
+	kfree(handle);
+	return error;
+}
+
+static void kbd_disconnect(struct input_handle *handle)
+{
+	input_close_device(handle);
+	input_unregister_handle(handle);
+	kfree(handle);
+}
+
+/*
+ * Start keyboard handler on the new keyboard by refreshing LED state to
+ * match the rest of the system.
+ */
+static void kbd_start(struct input_handle *handle)
+{
+	tasklet_disable(&keyboard_tasklet);
+
+	if (ledstate != -1U)
+		kbd_update_leds_helper(handle, &ledstate);
+
+	tasklet_enable(&keyboard_tasklet);
+}
+
+static const struct input_device_id kbd_ids[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+		.evbit = { BIT_MASK(EV_KEY) },
+	},
+
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+		.evbit = { BIT_MASK(EV_SND) },
+	},
+
+	{ },    /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(input, kbd_ids);
+
+static struct input_handler kbd_handler = {
+	.event		= kbd_event,
+	.match		= kbd_match,
+	.connect	= kbd_connect,
+	.disconnect	= kbd_disconnect,
+	.start		= kbd_start,
+	.name		= "kbd",
+	.id_table	= kbd_ids,
+};
+
+int __init kbd_init(void)
+{
+	int i;
+	int error;
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		kbd_table[i].ledflagstate = kbd_defleds();
+		kbd_table[i].default_ledflagstate = kbd_defleds();
+		kbd_table[i].ledmode = LED_SHOW_FLAGS;
+		kbd_table[i].lockstate = KBD_DEFLOCK;
+		kbd_table[i].slockstate = 0;
+		kbd_table[i].modeflags = KBD_DEFMODE;
+		kbd_table[i].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
+	}
+
+	kbd_init_leds();
+
+	error = input_register_handler(&kbd_handler);
+	if (error)
+		return error;
+
+	tasklet_enable(&keyboard_tasklet);
+	tasklet_schedule(&keyboard_tasklet);
+
+	return 0;
+}
+
+/* Ioctl support code */
+
+/**
+ *	vt_do_diacrit		-	diacritical table updates
+ *	@cmd: ioctl request
+ *	@udp: pointer to user data for ioctl
+ *	@perm: permissions check computed by caller
+ *
+ *	Update the diacritical tables atomically and safely. Lock them
+ *	against simultaneous keypresses
+ */
+int vt_do_diacrit(unsigned int cmd, void __user *udp, int perm)
+{
+	unsigned long flags;
+	int asize;
+	int ret = 0;
+
+	switch (cmd) {
+	case KDGKBDIACR:
+	{
+		struct kbdiacrs __user *a = udp;
+		struct kbdiacr *dia;
+		int i;
+
+		dia = kmalloc_array(MAX_DIACR, sizeof(struct kbdiacr),
+								GFP_KERNEL);
+		if (!dia)
+			return -ENOMEM;
+
+		/* Lock the diacriticals table, make a copy and then
+		   copy it after we unlock */
+		spin_lock_irqsave(&kbd_event_lock, flags);
+
+		asize = accent_table_size;
+		for (i = 0; i < asize; i++) {
+			dia[i].diacr = conv_uni_to_8bit(
+						accent_table[i].diacr);
+			dia[i].base = conv_uni_to_8bit(
+						accent_table[i].base);
+			dia[i].result = conv_uni_to_8bit(
+						accent_table[i].result);
+		}
+		spin_unlock_irqrestore(&kbd_event_lock, flags);
+
+		if (put_user(asize, &a->kb_cnt))
+			ret = -EFAULT;
+		else  if (copy_to_user(a->kbdiacr, dia,
+				asize * sizeof(struct kbdiacr)))
+			ret = -EFAULT;
+		kfree(dia);
+		return ret;
+	}
+	case KDGKBDIACRUC:
+	{
+		struct kbdiacrsuc __user *a = udp;
+		void *buf;
+
+		buf = kmalloc_array(MAX_DIACR, sizeof(struct kbdiacruc),
+								GFP_KERNEL);
+		if (buf == NULL)
+			return -ENOMEM;
+
+		/* Lock the diacriticals table, make a copy and then
+		   copy it after we unlock */
+		spin_lock_irqsave(&kbd_event_lock, flags);
+
+		asize = accent_table_size;
+		memcpy(buf, accent_table, asize * sizeof(struct kbdiacruc));
+
+		spin_unlock_irqrestore(&kbd_event_lock, flags);
+
+		if (put_user(asize, &a->kb_cnt))
+			ret = -EFAULT;
+		else if (copy_to_user(a->kbdiacruc, buf,
+				asize*sizeof(struct kbdiacruc)))
+			ret = -EFAULT;
+		kfree(buf);
+		return ret;
+	}
+
+	case KDSKBDIACR:
+	{
+		struct kbdiacrs __user *a = udp;
+		struct kbdiacr *dia = NULL;
+		unsigned int ct;
+		int i;
+
+		if (!perm)
+			return -EPERM;
+		if (get_user(ct, &a->kb_cnt))
+			return -EFAULT;
+		if (ct >= MAX_DIACR)
+			return -EINVAL;
+
+		if (ct) {
+
+			dia = memdup_user(a->kbdiacr,
+					sizeof(struct kbdiacr) * ct);
+			if (IS_ERR(dia))
+				return PTR_ERR(dia);
+
+		}
+
+		spin_lock_irqsave(&kbd_event_lock, flags);
+		accent_table_size = ct;
+		for (i = 0; i < ct; i++) {
+			accent_table[i].diacr =
+					conv_8bit_to_uni(dia[i].diacr);
+			accent_table[i].base =
+					conv_8bit_to_uni(dia[i].base);
+			accent_table[i].result =
+					conv_8bit_to_uni(dia[i].result);
+		}
+		spin_unlock_irqrestore(&kbd_event_lock, flags);
+		kfree(dia);
+		return 0;
+	}
+
+	case KDSKBDIACRUC:
+	{
+		struct kbdiacrsuc __user *a = udp;
+		unsigned int ct;
+		void *buf = NULL;
+
+		if (!perm)
+			return -EPERM;
+
+		if (get_user(ct, &a->kb_cnt))
+			return -EFAULT;
+
+		if (ct >= MAX_DIACR)
+			return -EINVAL;
+
+		if (ct) {
+			buf = memdup_user(a->kbdiacruc,
+					  ct * sizeof(struct kbdiacruc));
+			if (IS_ERR(buf))
+				return PTR_ERR(buf);
+		} 
+		spin_lock_irqsave(&kbd_event_lock, flags);
+		if (ct)
+			memcpy(accent_table, buf,
+					ct * sizeof(struct kbdiacruc));
+		accent_table_size = ct;
+		spin_unlock_irqrestore(&kbd_event_lock, flags);
+		kfree(buf);
+		return 0;
+	}
+	}
+	return ret;
+}
+
+/**
+ *	vt_do_kdskbmode		-	set keyboard mode ioctl
+ *	@console: the console to use
+ *	@arg: the requested mode
+ *
+ *	Update the keyboard mode bits while holding the correct locks.
+ *	Return 0 for success or an error code.
+ */
+int vt_do_kdskbmode(unsigned int console, unsigned int arg)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	switch(arg) {
+	case K_RAW:
+		kb->kbdmode = VC_RAW;
+		break;
+	case K_MEDIUMRAW:
+		kb->kbdmode = VC_MEDIUMRAW;
+		break;
+	case K_XLATE:
+		kb->kbdmode = VC_XLATE;
+		do_compute_shiftstate();
+		break;
+	case K_UNICODE:
+		kb->kbdmode = VC_UNICODE;
+		do_compute_shiftstate();
+		break;
+	case K_OFF:
+		kb->kbdmode = VC_OFF;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+	return ret;
+}
+
+/**
+ *	vt_do_kdskbmeta		-	set keyboard meta state
+ *	@console: the console to use
+ *	@arg: the requested meta state
+ *
+ *	Update the keyboard meta bits while holding the correct locks.
+ *	Return 0 for success or an error code.
+ */
+int vt_do_kdskbmeta(unsigned int console, unsigned int arg)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	switch(arg) {
+	case K_METABIT:
+		clr_vc_kbd_mode(kb, VC_META);
+		break;
+	case K_ESCPREFIX:
+		set_vc_kbd_mode(kb, VC_META);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+	return ret;
+}
+
+int vt_do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc,
+								int perm)
+{
+	struct kbkeycode tmp;
+	int kc = 0;
+
+	if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
+		return -EFAULT;
+	switch (cmd) {
+	case KDGETKEYCODE:
+		kc = getkeycode(tmp.scancode);
+		if (kc >= 0)
+			kc = put_user(kc, &user_kbkc->keycode);
+		break;
+	case KDSETKEYCODE:
+		if (!perm)
+			return -EPERM;
+		kc = setkeycode(tmp.scancode, tmp.keycode);
+		break;
+	}
+	return kc;
+}
+
+static unsigned short vt_kdgkbent(unsigned char kbdmode, unsigned char idx,
+		unsigned char map)
+{
+	unsigned short *key_map, val;
+	unsigned long flags;
+
+	/* Ensure another thread doesn't free it under us */
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	key_map = key_maps[map];
+	if (key_map) {
+		val = U(key_map[idx]);
+		if (kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
+			val = K_HOLE;
+	} else
+		val = idx ? K_HOLE : K_NOSUCHMAP;
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+
+	return val;
+}
+
+static int vt_kdskbent(unsigned char kbdmode, unsigned char idx,
+		unsigned char map, unsigned short val)
+{
+	unsigned long flags;
+	unsigned short *key_map, *new_map, oldval;
+
+	if (!idx && val == K_NOSUCHMAP) {
+		spin_lock_irqsave(&kbd_event_lock, flags);
+		/* deallocate map */
+		key_map = key_maps[map];
+		if (map && key_map) {
+			key_maps[map] = NULL;
+			if (key_map[0] == U(K_ALLOCATED)) {
+				kfree(key_map);
+				keymap_count--;
+			}
+		}
+		spin_unlock_irqrestore(&kbd_event_lock, flags);
+
+		return 0;
+	}
+
+	if (KTYP(val) < NR_TYPES) {
+		if (KVAL(val) > max_vals[KTYP(val)])
+			return -EINVAL;
+	} else if (kbdmode != VC_UNICODE)
+		return -EINVAL;
+
+	/* ++Geert: non-PC keyboards may generate keycode zero */
+#if !defined(__mc68000__) && !defined(__powerpc__)
+	/* assignment to entry 0 only tests validity of args */
+	if (!idx)
+		return 0;
+#endif
+
+	new_map = kmalloc(sizeof(plain_map), GFP_KERNEL);
+	if (!new_map)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	key_map = key_maps[map];
+	if (key_map == NULL) {
+		int j;
+
+		if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
+		    !capable(CAP_SYS_RESOURCE)) {
+			spin_unlock_irqrestore(&kbd_event_lock, flags);
+			kfree(new_map);
+			return -EPERM;
+		}
+		key_maps[map] = new_map;
+		key_map = new_map;
+		key_map[0] = U(K_ALLOCATED);
+		for (j = 1; j < NR_KEYS; j++)
+			key_map[j] = U(K_HOLE);
+		keymap_count++;
+	} else
+		kfree(new_map);
+
+	oldval = U(key_map[idx]);
+	if (val == oldval)
+		goto out;
+
+	/* Attention Key */
+	if ((oldval == K_SAK || val == K_SAK) && !capable(CAP_SYS_ADMIN)) {
+		spin_unlock_irqrestore(&kbd_event_lock, flags);
+		return -EPERM;
+	}
+
+	key_map[idx] = U(val);
+	if (!map && (KTYP(oldval) == KT_SHIFT || KTYP(val) == KT_SHIFT))
+		do_compute_shiftstate();
+out:
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+
+	return 0;
+}
+
+int vt_do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm,
+						unsigned int console)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	struct kbentry kbe;
+
+	if (copy_from_user(&kbe, user_kbe, sizeof(struct kbentry)))
+		return -EFAULT;
+
+	switch (cmd) {
+	case KDGKBENT:
+		return put_user(vt_kdgkbent(kb->kbdmode, kbe.kb_index,
+					kbe.kb_table),
+				&user_kbe->kb_value);
+	case KDSKBENT:
+		if (!perm || !capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+		return vt_kdskbent(kb->kbdmode, kbe.kb_index, kbe.kb_table,
+				kbe.kb_value);
+	}
+	return 0;
+}
+
+static char *vt_kdskbsent(char *kbs, unsigned char cur)
+{
+	static DECLARE_BITMAP(is_kmalloc, MAX_NR_FUNC);
+	char *cur_f = func_table[cur];
+
+	if (cur_f && strlen(cur_f) >= strlen(kbs)) {
+		strcpy(cur_f, kbs);
+		return kbs;
+	}
+
+	func_table[cur] = kbs;
+
+	return __test_and_set_bit(cur, is_kmalloc) ? cur_f : NULL;
+}
+
+int vt_do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
+{
+	unsigned char kb_func;
+	unsigned long flags;
+	char *kbs;
+	int ret;
+
+	if (get_user(kb_func, &user_kdgkb->kb_func))
+		return -EFAULT;
+
+	kb_func = array_index_nospec(kb_func, MAX_NR_FUNC);
+
+	switch (cmd) {
+	case KDGKBSENT: {
+		/* size should have been a struct member */
+		ssize_t len = sizeof(user_kdgkb->kb_string);
+
+		kbs = kmalloc(len, GFP_KERNEL);
+		if (!kbs)
+			return -ENOMEM;
+
+		spin_lock_irqsave(&func_buf_lock, flags);
+		len = strlcpy(kbs, func_table[kb_func] ? : "", len);
+		spin_unlock_irqrestore(&func_buf_lock, flags);
+
+		ret = copy_to_user(user_kdgkb->kb_string, kbs, len + 1) ?
+			-EFAULT : 0;
+
+		break;
+	}
+	case KDSKBSENT:
+		if (!perm || !capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+
+		kbs = strndup_user(user_kdgkb->kb_string,
+				sizeof(user_kdgkb->kb_string));
+		if (IS_ERR(kbs))
+			return PTR_ERR(kbs);
+
+		spin_lock_irqsave(&func_buf_lock, flags);
+		kbs = vt_kdskbsent(kbs, kb_func);
+		spin_unlock_irqrestore(&func_buf_lock, flags);
+
+		ret = 0;
+		break;
+	}
+
+	kfree(kbs);
+
+	return ret;
+}
+
+int vt_do_kdskled(unsigned int console, int cmd, unsigned long arg, int perm)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+        unsigned long flags;
+	unsigned char ucval;
+
+        switch(cmd) {
+	/* the ioctls below read/set the flags usually shown in the leds */
+	/* don't use them - they will go away without warning */
+	case KDGKBLED:
+                spin_lock_irqsave(&kbd_event_lock, flags);
+		ucval = kb->ledflagstate | (kb->default_ledflagstate << 4);
+                spin_unlock_irqrestore(&kbd_event_lock, flags);
+		return put_user(ucval, (char __user *)arg);
+
+	case KDSKBLED:
+		if (!perm)
+			return -EPERM;
+		if (arg & ~0x77)
+			return -EINVAL;
+                spin_lock_irqsave(&led_lock, flags);
+		kb->ledflagstate = (arg & 7);
+		kb->default_ledflagstate = ((arg >> 4) & 7);
+		set_leds();
+                spin_unlock_irqrestore(&led_lock, flags);
+		return 0;
+
+	/* the ioctls below only set the lights, not the functions */
+	/* for those, see KDGKBLED and KDSKBLED above */
+	case KDGETLED:
+		ucval = getledstate();
+		return put_user(ucval, (char __user *)arg);
+
+	case KDSETLED:
+		if (!perm)
+			return -EPERM;
+		setledstate(kb, arg);
+		return 0;
+        }
+        return -ENOIOCTLCMD;
+}
+
+int vt_do_kdgkbmode(unsigned int console)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	/* This is a spot read so needs no locking */
+	switch (kb->kbdmode) {
+	case VC_RAW:
+		return K_RAW;
+	case VC_MEDIUMRAW:
+		return K_MEDIUMRAW;
+	case VC_UNICODE:
+		return K_UNICODE;
+	case VC_OFF:
+		return K_OFF;
+	default:
+		return K_XLATE;
+	}
+}
+
+/**
+ *	vt_do_kdgkbmeta		-	report meta status
+ *	@console: console to report
+ *
+ *	Report the meta flag status of this console
+ */
+int vt_do_kdgkbmeta(unsigned int console)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+        /* Again a spot read so no locking */
+	return vc_kbd_mode(kb, VC_META) ? K_ESCPREFIX : K_METABIT;
+}
+
+/**
+ *	vt_reset_unicode	-	reset the unicode status
+ *	@console: console being reset
+ *
+ *	Restore the unicode console state to its default
+ */
+void vt_reset_unicode(unsigned int console)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	kbd_table[console].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+}
+
+/**
+ *	vt_get_shift_state	-	shift bit state
+ *
+ *	Report the shift bits from the keyboard state. We have to export
+ *	this to support some oddities in the vt layer.
+ */
+int vt_get_shift_state(void)
+{
+        /* Don't lock as this is a transient report */
+        return shift_state;
+}
+
+/**
+ *	vt_reset_keyboard	-	reset keyboard state
+ *	@console: console to reset
+ *
+ *	Reset the keyboard bits for a console as part of a general console
+ *	reset event
+ */
+void vt_reset_keyboard(unsigned int console)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	unsigned long flags;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	set_vc_kbd_mode(kb, VC_REPEAT);
+	clr_vc_kbd_mode(kb, VC_CKMODE);
+	clr_vc_kbd_mode(kb, VC_APPLIC);
+	clr_vc_kbd_mode(kb, VC_CRLF);
+	kb->lockstate = 0;
+	kb->slockstate = 0;
+	spin_lock(&led_lock);
+	kb->ledmode = LED_SHOW_FLAGS;
+	kb->ledflagstate = kb->default_ledflagstate;
+	spin_unlock(&led_lock);
+	/* do not do set_leds here because this causes an endless tasklet loop
+	   when the keyboard hasn't been initialized yet */
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+}
+
+/**
+ *	vt_get_kbd_mode_bit	-	read keyboard status bits
+ *	@console: console to read from
+ *	@bit: mode bit to read
+ *
+ *	Report back a vt mode bit. We do this without locking so the
+ *	caller must be sure that there are no synchronization needs
+ */
+
+int vt_get_kbd_mode_bit(unsigned int console, int bit)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	return vc_kbd_mode(kb, bit);
+}
+
+/**
+ *	vt_set_kbd_mode_bit	-	read keyboard status bits
+ *	@console: console to read from
+ *	@bit: mode bit to read
+ *
+ *	Set a vt mode bit. We do this without locking so the
+ *	caller must be sure that there are no synchronization needs
+ */
+
+void vt_set_kbd_mode_bit(unsigned int console, int bit)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	unsigned long flags;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	set_vc_kbd_mode(kb, bit);
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+}
+
+/**
+ *	vt_clr_kbd_mode_bit	-	read keyboard status bits
+ *	@console: console to read from
+ *	@bit: mode bit to read
+ *
+ *	Report back a vt mode bit. We do this without locking so the
+ *	caller must be sure that there are no synchronization needs
+ */
+
+void vt_clr_kbd_mode_bit(unsigned int console, int bit)
+{
+	struct kbd_struct *kb = &kbd_table[console];
+	unsigned long flags;
+
+	spin_lock_irqsave(&kbd_event_lock, flags);
+	clr_vc_kbd_mode(kb, bit);
+	spin_unlock_irqrestore(&kbd_event_lock, flags);
+}
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
new file mode 100644
index 000000000..8967c3a0d
--- /dev/null
+++ b/drivers/tty/vt/selection.c
@@ -0,0 +1,421 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This module exports the functions:
+ *
+ *     'int set_selection_user(struct tiocl_selection __user *,
+ *			       struct tty_struct *)'
+ *     'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
+ *     'void clear_selection(void)'
+ *     'int paste_selection(struct tty_struct *)'
+ *     'int sel_loadlut(char __user *)'
+ *
+ * Now that /dev/vcs exists, most of this can disappear again.
+ */
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/uaccess.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/consolemap.h>
+#include <linux/selection.h>
+#include <linux/tiocl.h>
+#include <linux/console.h>
+#include <linux/tty_flip.h>
+
+#include <linux/sched/signal.h>
+
+/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
+#define is_space_on_vt(c)	((c) == ' ')
+
+/* FIXME: all this needs locking */
+static struct vc_selection {
+	struct mutex lock;
+	struct vc_data *cons;			/* must not be deallocated */
+	char *buffer;
+	unsigned int buf_len;
+	volatile int start;			/* cleared by clear_selection */
+	int end;
+} vc_sel = {
+	.lock = __MUTEX_INITIALIZER(vc_sel.lock),
+	.start = -1,
+};
+
+/* clear_selection, highlight and highlight_pointer can be called
+   from interrupt (via scrollback/front) */
+
+/* set reverse video on characters s-e of console with selection. */
+static inline void highlight(const int s, const int e)
+{
+	invert_screen(vc_sel.cons, s, e-s+2, true);
+}
+
+/* use complementary color to show the pointer */
+static inline void highlight_pointer(const int where)
+{
+	complement_pos(vc_sel.cons, where);
+}
+
+static u32
+sel_pos(int n, bool unicode)
+{
+	if (unicode)
+		return screen_glyph_unicode(vc_sel.cons, n / 2);
+	return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n),
+			false);
+}
+
+/**
+ *	clear_selection		-	remove current selection
+ *
+ *	Remove the current selection highlight, if any from the console
+ *	holding the selection. The caller must hold the console lock.
+ */
+void clear_selection(void)
+{
+	highlight_pointer(-1); /* hide the pointer */
+	if (vc_sel.start != -1) {
+		highlight(vc_sel.start, vc_sel.end);
+		vc_sel.start = -1;
+	}
+}
+EXPORT_SYMBOL_GPL(clear_selection);
+
+bool vc_is_sel(struct vc_data *vc)
+{
+	return vc == vc_sel.cons;
+}
+
+/*
+ * User settable table: what characters are to be considered alphabetic?
+ * 128 bits. Locked by the console lock.
+ */
+static u32 inwordLut[]={
+  0x00000000, /* control chars     */
+  0x03FFE000, /* digits and "-./"  */
+  0x87FFFFFE, /* uppercase and '_' */
+  0x07FFFFFE, /* lowercase         */
+};
+
+static inline int inword(const u32 c)
+{
+	return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
+}
+
+/**
+ *	sel_loadlut()		-	load the LUT table
+ *	@p: user table
+ *
+ *	Load the LUT table from user space. The caller must hold the console
+ *	lock. Make a temporary copy so a partial update doesn't make a mess.
+ */
+int sel_loadlut(char __user *p)
+{
+	u32 tmplut[ARRAY_SIZE(inwordLut)];
+	if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
+		return -EFAULT;
+	memcpy(inwordLut, tmplut, sizeof(inwordLut));
+	return 0;
+}
+
+/* does screen address p correspond to character at LH/RH edge of screen? */
+static inline int atedge(const int p, int size_row)
+{
+	return (!(p % size_row)	|| !((p + 2) % size_row));
+}
+
+/* stores the char in UTF8 and returns the number of bytes used (1-4) */
+static int store_utf8(u32 c, char *p)
+{
+	if (c < 0x80) {
+		/*  0******* */
+		p[0] = c;
+		return 1;
+	} else if (c < 0x800) {
+		/* 110***** 10****** */
+		p[0] = 0xc0 | (c >> 6);
+		p[1] = 0x80 | (c & 0x3f);
+		return 2;
+	} else if (c < 0x10000) {
+		/* 1110**** 10****** 10****** */
+		p[0] = 0xe0 | (c >> 12);
+		p[1] = 0x80 | ((c >> 6) & 0x3f);
+		p[2] = 0x80 | (c & 0x3f);
+		return 3;
+	} else if (c < 0x110000) {
+		/* 11110*** 10****** 10****** 10****** */
+		p[0] = 0xf0 | (c >> 18);
+		p[1] = 0x80 | ((c >> 12) & 0x3f);
+		p[2] = 0x80 | ((c >> 6) & 0x3f);
+		p[3] = 0x80 | (c & 0x3f);
+		return 4;
+	} else {
+		/* outside Unicode, replace with U+FFFD */
+		p[0] = 0xef;
+		p[1] = 0xbf;
+		p[2] = 0xbd;
+		return 3;
+	}
+}
+
+/**
+ *	set_selection_user	-	set the current selection.
+ *	@sel: user selection info
+ *	@tty: the console tty
+ *
+ *	Invoked by the ioctl handle for the vt layer.
+ *
+ *	The entire selection process is managed under the console_lock. It's
+ *	 a lot under the lock but its hardly a performance path
+ */
+int set_selection_user(const struct tiocl_selection __user *sel,
+		       struct tty_struct *tty)
+{
+	struct tiocl_selection v;
+
+	if (copy_from_user(&v, sel, sizeof(*sel)))
+		return -EFAULT;
+
+	return set_selection_kernel(&v, tty);
+}
+
+static int vc_selection_store_chars(struct vc_data *vc, bool unicode)
+{
+	char *bp, *obp;
+	unsigned int i;
+
+	/* Allocate a new buffer before freeing the old one ... */
+	/* chars can take up to 4 bytes with unicode */
+	bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,
+			   GFP_KERNEL | __GFP_NOWARN);
+	if (!bp) {
+		printk(KERN_WARNING "selection: kmalloc() failed\n");
+		clear_selection();
+		return -ENOMEM;
+	}
+	kfree(vc_sel.buffer);
+	vc_sel.buffer = bp;
+
+	obp = bp;
+	for (i = vc_sel.start; i <= vc_sel.end; i += 2) {
+		u32 c = sel_pos(i, unicode);
+		if (unicode)
+			bp += store_utf8(c, bp);
+		else
+			*bp++ = c;
+		if (!is_space_on_vt(c))
+			obp = bp;
+		if (!((i + 2) % vc->vc_size_row)) {
+			/* strip trailing blanks from line and add newline,
+			   unless non-space at end of line. */
+			if (obp != bp) {
+				bp = obp;
+				*bp++ = '\r';
+			}
+			obp = bp;
+		}
+	}
+	vc_sel.buf_len = bp - vc_sel.buffer;
+
+	return 0;
+}
+
+static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps,
+		int pe)
+{
+	int new_sel_start, new_sel_end, spc;
+	bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
+
+	switch (mode) {
+	case TIOCL_SELCHAR:	/* character-by-character selection */
+		new_sel_start = ps;
+		new_sel_end = pe;
+		break;
+	case TIOCL_SELWORD:	/* word-by-word selection */
+		spc = is_space_on_vt(sel_pos(ps, unicode));
+		for (new_sel_start = ps; ; ps -= 2) {
+			if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) ||
+			    (!spc && !inword(sel_pos(ps, unicode))))
+				break;
+			new_sel_start = ps;
+			if (!(ps % vc->vc_size_row))
+				break;
+		}
+
+		spc = is_space_on_vt(sel_pos(pe, unicode));
+		for (new_sel_end = pe; ; pe += 2) {
+			if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) ||
+			    (!spc && !inword(sel_pos(pe, unicode))))
+				break;
+			new_sel_end = pe;
+			if (!((pe + 2) % vc->vc_size_row))
+				break;
+		}
+		break;
+	case TIOCL_SELLINE:	/* line-by-line selection */
+		new_sel_start = rounddown(ps, vc->vc_size_row);
+		new_sel_end = rounddown(pe, vc->vc_size_row) +
+			vc->vc_size_row - 2;
+		break;
+	case TIOCL_SELPOINTER:
+		highlight_pointer(pe);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+
+	/* remove the pointer */
+	highlight_pointer(-1);
+
+	/* select to end of line if on trailing space */
+	if (new_sel_end > new_sel_start &&
+		!atedge(new_sel_end, vc->vc_size_row) &&
+		is_space_on_vt(sel_pos(new_sel_end, unicode))) {
+		for (pe = new_sel_end + 2; ; pe += 2)
+			if (!is_space_on_vt(sel_pos(pe, unicode)) ||
+			    atedge(pe, vc->vc_size_row))
+				break;
+		if (is_space_on_vt(sel_pos(pe, unicode)))
+			new_sel_end = pe;
+	}
+	if (vc_sel.start == -1)	/* no current selection */
+		highlight(new_sel_start, new_sel_end);
+	else if (new_sel_start == vc_sel.start)
+	{
+		if (new_sel_end == vc_sel.end)	/* no action required */
+			return 0;
+		else if (new_sel_end > vc_sel.end)	/* extend to right */
+			highlight(vc_sel.end + 2, new_sel_end);
+		else				/* contract from right */
+			highlight(new_sel_end + 2, vc_sel.end);
+	}
+	else if (new_sel_end == vc_sel.end)
+	{
+		if (new_sel_start < vc_sel.start) /* extend to left */
+			highlight(new_sel_start, vc_sel.start - 2);
+		else				/* contract from left */
+			highlight(vc_sel.start, new_sel_start - 2);
+	}
+	else	/* some other case; start selection from scratch */
+	{
+		clear_selection();
+		highlight(new_sel_start, new_sel_end);
+	}
+	vc_sel.start = new_sel_start;
+	vc_sel.end = new_sel_end;
+
+	return vc_selection_store_chars(vc, unicode);
+}
+
+static int vc_selection(struct vc_data *vc, struct tiocl_selection *v,
+		struct tty_struct *tty)
+{
+	int ps, pe;
+
+	poke_blanked_console();
+
+	if (v->sel_mode == TIOCL_SELCLEAR) {
+		/* useful for screendump without selection highlights */
+		clear_selection();
+		return 0;
+	}
+
+	v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1);
+	v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1);
+	v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1);
+	v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1);
+
+	if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
+		mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
+			     v->ys);
+		return 0;
+	}
+
+	ps = v->ys * vc->vc_size_row + (v->xs << 1);
+	pe = v->ye * vc->vc_size_row + (v->xe << 1);
+	if (ps > pe)	/* make vc_sel.start <= vc_sel.end */
+		swap(ps, pe);
+
+	if (vc_sel.cons != vc) {
+		clear_selection();
+		vc_sel.cons = vc;
+	}
+
+	return vc_do_selection(vc, v->sel_mode, ps, pe);
+}
+
+int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
+{
+	int ret;
+
+	mutex_lock(&vc_sel.lock);
+	console_lock();
+	ret = vc_selection(vc_cons[fg_console].d, v, tty);
+	console_unlock();
+	mutex_unlock(&vc_sel.lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(set_selection_kernel);
+
+/* Insert the contents of the selection buffer into the
+ * queue of the tty associated with the current console.
+ * Invoked by ioctl().
+ *
+ * Locking: called without locks. Calls the ldisc wrongly with
+ * unsafe methods,
+ */
+int paste_selection(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+	int	pasted = 0;
+	size_t count;
+	struct  tty_ldisc *ld;
+	DECLARE_WAITQUEUE(wait, current);
+	int ret = 0;
+
+	console_lock();
+	poke_blanked_console();
+	console_unlock();
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return -EIO;	/* ldisc was hung up */
+	tty_buffer_lock_exclusive(&vc->port);
+
+	add_wait_queue(&vc->paste_wait, &wait);
+	mutex_lock(&vc_sel.lock);
+	while (vc_sel.buffer && vc_sel.buf_len > pasted) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+		if (tty_throttled(tty)) {
+			mutex_unlock(&vc_sel.lock);
+			schedule();
+			mutex_lock(&vc_sel.lock);
+			continue;
+		}
+		__set_current_state(TASK_RUNNING);
+		count = vc_sel.buf_len - pasted;
+		count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL,
+					      count);
+		pasted += count;
+	}
+	mutex_unlock(&vc_sel.lock);
+	remove_wait_queue(&vc->paste_wait, &wait);
+	__set_current_state(TASK_RUNNING);
+
+	tty_buffer_unlock_exclusive(&vc->port);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(paste_selection);
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
new file mode 100644
index 000000000..829c4be66
--- /dev/null
+++ b/drivers/tty/vt/vc_screen.c
@@ -0,0 +1,822 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Provide access to virtual console memory.
+ * /dev/vcs: the screen as it is being viewed right now (possibly scrolled)
+ * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63)
+ *            [minor: N]
+ *
+ * /dev/vcsaN: idem, but including attributes, and prefixed with
+ *	the 4 bytes lines,columns,x,y (as screendump used to give).
+ *	Attribute/character pair is in native endianity.
+ *            [minor: N+128]
+ *
+ * /dev/vcsuN: similar to /dev/vcsaN but using 4-byte unicode values
+ *	instead of 1-byte screen glyph values.
+ *            [minor: N+64]
+ *
+ * /dev/vcsuaN: same idea as /dev/vcsaN for unicode (not yet implemented).
+ *
+ * This replaces screendump and part of selection, so that the system
+ * administrator can control access using file system permissions.
+ *
+ * aeb@cwi.nl - efter Friedas begravelse - 950211
+ *
+ * machek@k332.feld.cvut.cz - modified not to send characters to wrong console
+ *	 - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...)
+ *	 - making it shorter - scr_readw are macros which expand in PRETTY long code
+ */
+
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/tty.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/kbd_kern.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+
+#include <linux/uaccess.h>
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+
+#define HEADER_SIZE	4u
+#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
+
+/*
+ * Our minor space:
+ *
+ *   0 ... 63	glyph mode without attributes
+ *  64 ... 127	unicode mode without attributes
+ * 128 ... 191	glyph mode with attributes
+ * 192 ... 255	unused (reserved for unicode with attributes)
+ *
+ * This relies on MAX_NR_CONSOLES being  <= 63, meaning 63 actual consoles
+ * with minors 0, 64, 128 and 192 being proxies for the foreground console.
+ */
+#if MAX_NR_CONSOLES > 63
+#warning "/dev/vcs* devices may not accommodate more than 63 consoles"
+#endif
+
+#define console(inode)		(iminor(inode) & 63)
+#define use_unicode(inode)	(iminor(inode) & 64)
+#define use_attributes(inode)	(iminor(inode) & 128)
+
+
+struct vcs_poll_data {
+	struct notifier_block notifier;
+	unsigned int cons_num;
+	int event;
+	wait_queue_head_t waitq;
+	struct fasync_struct *fasync;
+};
+
+static int
+vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
+{
+	struct vt_notifier_param *param = _param;
+	struct vc_data *vc = param->vc;
+	struct vcs_poll_data *poll =
+		container_of(nb, struct vcs_poll_data, notifier);
+	int currcons = poll->cons_num;
+	int fa_band;
+
+	switch (code) {
+	case VT_UPDATE:
+		fa_band = POLL_PRI;
+		break;
+	case VT_DEALLOCATE:
+		fa_band = POLL_HUP;
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	if (currcons == 0)
+		currcons = fg_console;
+	else
+		currcons--;
+	if (currcons != vc->vc_num)
+		return NOTIFY_DONE;
+
+	poll->event = code;
+	wake_up_interruptible(&poll->waitq);
+	kill_fasync(&poll->fasync, SIGIO, fa_band);
+	return NOTIFY_OK;
+}
+
+static void
+vcs_poll_data_free(struct vcs_poll_data *poll)
+{
+	unregister_vt_notifier(&poll->notifier);
+	kfree(poll);
+}
+
+static struct vcs_poll_data *
+vcs_poll_data_get(struct file *file)
+{
+	struct vcs_poll_data *poll = file->private_data, *kill = NULL;
+
+	if (poll)
+		return poll;
+
+	poll = kzalloc(sizeof(*poll), GFP_KERNEL);
+	if (!poll)
+		return NULL;
+	poll->cons_num = console(file_inode(file));
+	init_waitqueue_head(&poll->waitq);
+	poll->notifier.notifier_call = vcs_notifier;
+	/*
+	 * In order not to lose any update event, we must pretend one might
+	 * have occurred before we have a chance to register our notifier.
+	 * This is also how user space has come to detect which kernels
+	 * support POLLPRI on /dev/vcs* devices i.e. using poll() with
+	 * POLLPRI and a zero timeout.
+	 */
+	poll->event = VT_UPDATE;
+
+	if (register_vt_notifier(&poll->notifier) != 0) {
+		kfree(poll);
+		return NULL;
+	}
+
+	/*
+	 * This code may be called either through ->poll() or ->fasync().
+	 * If we have two threads using the same file descriptor, they could
+	 * both enter this function, both notice that the structure hasn't
+	 * been allocated yet and go ahead allocating it in parallel, but
+	 * only one of them must survive and be shared otherwise we'd leak
+	 * memory with a dangling notifier callback.
+	 */
+	spin_lock(&file->f_lock);
+	if (!file->private_data) {
+		file->private_data = poll;
+	} else {
+		/* someone else raced ahead of us */
+		kill = poll;
+		poll = file->private_data;
+	}
+	spin_unlock(&file->f_lock);
+	if (kill)
+		vcs_poll_data_free(kill);
+
+	return poll;
+}
+
+/**
+ * vcs_vc -- return VC for @inode
+ * @inode: inode for which to return a VC
+ * @viewed: returns whether this console is currently foreground (viewed)
+ *
+ * Must be called with console_lock.
+ */
+static struct vc_data *vcs_vc(struct inode *inode, bool *viewed)
+{
+	unsigned int currcons = console(inode);
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (currcons == 0) {
+		currcons = fg_console;
+		if (viewed)
+			*viewed = true;
+	} else {
+		currcons--;
+		if (viewed)
+			*viewed = false;
+	}
+	return vc_cons[currcons].d;
+}
+
+/**
+ * vcs_size -- return size for a VC in @vc
+ * @vc: which VC
+ * @attr: does it use attributes?
+ * @unicode: is it unicode?
+ *
+ * Must be called with console_lock.
+ */
+static int vcs_size(const struct vc_data *vc, bool attr, bool unicode)
+{
+	int size;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	size = vc->vc_rows * vc->vc_cols;
+
+	if (attr) {
+		if (unicode)
+			return -EOPNOTSUPP;
+
+		size = 2 * size + HEADER_SIZE;
+	} else if (unicode)
+		size *= 4;
+
+	return size;
+}
+
+static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
+{
+	struct inode *inode = file_inode(file);
+	struct vc_data *vc;
+	int size;
+
+	console_lock();
+	vc = vcs_vc(inode, NULL);
+	if (!vc) {
+		console_unlock();
+		return -ENXIO;
+	}
+
+	size = vcs_size(vc, use_attributes(inode), use_unicode(inode));
+	console_unlock();
+	if (size < 0)
+		return size;
+	return fixed_size_llseek(file, offset, orig, size);
+}
+
+static int vcs_read_buf_uni(struct vc_data *vc, char *con_buf,
+		unsigned int pos, unsigned int count, bool viewed)
+{
+	unsigned int nr, row, col, maxcol = vc->vc_cols;
+	int ret;
+
+	ret = vc_uniscr_check(vc);
+	if (ret)
+		return ret;
+
+	pos /= 4;
+	row = pos / maxcol;
+	col = pos % maxcol;
+	nr = maxcol - col;
+	do {
+		if (nr > count / 4)
+			nr = count / 4;
+		vc_uniscr_copy_line(vc, con_buf, viewed, row, col, nr);
+		con_buf += nr * 4;
+		count -= nr * 4;
+		row++;
+		col = 0;
+		nr = maxcol;
+	} while (count);
+
+	return 0;
+}
+
+static void vcs_read_buf_noattr(const struct vc_data *vc, char *con_buf,
+		unsigned int pos, unsigned int count, bool viewed)
+{
+	u16 *org;
+	unsigned int col, maxcol = vc->vc_cols;
+
+	org = screen_pos(vc, pos, viewed);
+	col = pos % maxcol;
+	pos += maxcol - col;
+
+	while (count-- > 0) {
+		*con_buf++ = (vcs_scr_readw(vc, org++) & 0xff);
+		if (++col == maxcol) {
+			org = screen_pos(vc, pos, viewed);
+			col = 0;
+			pos += maxcol;
+		}
+	}
+}
+
+static unsigned int vcs_read_buf(const struct vc_data *vc, char *con_buf,
+		unsigned int pos, unsigned int count, bool viewed,
+		unsigned int *skip)
+{
+	u16 *org, *con_buf16;
+	unsigned int col, maxcol = vc->vc_cols;
+	unsigned int filled = count;
+
+	if (pos < HEADER_SIZE) {
+		/* clamp header values if they don't fit */
+		con_buf[0] = min(vc->vc_rows, 0xFFu);
+		con_buf[1] = min(vc->vc_cols, 0xFFu);
+		getconsxy(vc, con_buf + 2);
+
+		*skip += pos;
+		count += pos;
+		if (count > CON_BUF_SIZE) {
+			count = CON_BUF_SIZE;
+			filled = count - pos;
+		}
+
+		/* Advance state pointers and move on. */
+		count -= min(HEADER_SIZE, count);
+		pos = HEADER_SIZE;
+		con_buf += HEADER_SIZE;
+		/* If count >= 0, then pos is even... */
+	} else if (pos & 1) {
+		/*
+		 * Skip first byte for output if start address is odd. Update
+		 * region sizes up/down depending on free space in buffer.
+		 */
+		(*skip)++;
+		if (count < CON_BUF_SIZE)
+			count++;
+		else
+			filled--;
+	}
+
+	if (!count)
+		return filled;
+
+	pos -= HEADER_SIZE;
+	pos /= 2;
+	col = pos % maxcol;
+
+	org = screen_pos(vc, pos, viewed);
+	pos += maxcol - col;
+
+	/*
+	 * Buffer has even length, so we can always copy character + attribute.
+	 * We do not copy last byte to userspace if count is odd.
+	 */
+	count = (count + 1) / 2;
+	con_buf16 = (u16 *)con_buf;
+
+	while (count) {
+		*con_buf16++ = vcs_scr_readw(vc, org++);
+		count--;
+		if (++col == maxcol) {
+			org = screen_pos(vc, pos, viewed);
+			col = 0;
+			pos += maxcol;
+		}
+	}
+
+	return filled;
+}
+
+static ssize_t
+vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *inode = file_inode(file);
+	struct vc_data *vc;
+	struct vcs_poll_data *poll;
+	unsigned int read;
+	ssize_t ret;
+	char *con_buf;
+	loff_t pos;
+	bool viewed, attr, uni_mode;
+
+	con_buf = (char *) __get_free_page(GFP_KERNEL);
+	if (!con_buf)
+		return -ENOMEM;
+
+	pos = *ppos;
+
+	/* Select the proper current console and verify
+	 * sanity of the situation under the console lock.
+	 */
+	console_lock();
+
+	uni_mode = use_unicode(inode);
+	attr = use_attributes(inode);
+
+	ret = -EINVAL;
+	if (pos < 0)
+		goto unlock_out;
+	/* we enforce 32-bit alignment for pos and count in unicode mode */
+	if (uni_mode && (pos | count) & 3)
+		goto unlock_out;
+
+	poll = file->private_data;
+	if (count && poll)
+		poll->event = 0;
+	read = 0;
+	ret = 0;
+	while (count) {
+		unsigned int this_round, skip = 0;
+		int size;
+
+		vc = vcs_vc(inode, &viewed);
+		if (!vc) {
+			ret = -ENXIO;
+			break;
+		}
+
+		/* Check whether we are above size each round,
+		 * as copy_to_user at the end of this loop
+		 * could sleep.
+		 */
+		size = vcs_size(vc, attr, uni_mode);
+		if (size < 0) {
+			ret = size;
+			break;
+		}
+		if (pos >= size)
+			break;
+		if (count > size - pos)
+			count = size - pos;
+
+		this_round = count;
+		if (this_round > CON_BUF_SIZE)
+			this_round = CON_BUF_SIZE;
+
+		/* Perform the whole read into the local con_buf.
+		 * Then we can drop the console spinlock and safely
+		 * attempt to move it to userspace.
+		 */
+
+		if (uni_mode) {
+			ret = vcs_read_buf_uni(vc, con_buf, pos, this_round,
+					viewed);
+			if (ret)
+				break;
+		} else if (!attr) {
+			vcs_read_buf_noattr(vc, con_buf, pos, this_round,
+					viewed);
+		} else {
+			this_round = vcs_read_buf(vc, con_buf, pos, this_round,
+					viewed, &skip);
+		}
+
+		/* Finally, release the console semaphore while we push
+		 * all the data to userspace from our temporary buffer.
+		 *
+		 * AKPM: Even though it's a semaphore, we should drop it because
+		 * the pagefault handling code may want to call printk().
+		 */
+
+		console_unlock();
+		ret = copy_to_user(buf, con_buf + skip, this_round);
+		console_lock();
+
+		if (ret) {
+			read += this_round - ret;
+			ret = -EFAULT;
+			break;
+		}
+		buf += this_round;
+		pos += this_round;
+		read += this_round;
+		count -= this_round;
+	}
+	*ppos += read;
+	if (read)
+		ret = read;
+unlock_out:
+	console_unlock();
+	free_page((unsigned long) con_buf);
+	return ret;
+}
+
+static u16 *vcs_write_buf_noattr(struct vc_data *vc, const char *con_buf,
+		unsigned int pos, unsigned int count, bool viewed, u16 **org0)
+{
+	u16 *org;
+	unsigned int col, maxcol = vc->vc_cols;
+
+	*org0 = org = screen_pos(vc, pos, viewed);
+	col = pos % maxcol;
+	pos += maxcol - col;
+
+	while (count > 0) {
+		unsigned char c = *con_buf++;
+
+		count--;
+		vcs_scr_writew(vc,
+			       (vcs_scr_readw(vc, org) & 0xff00) | c, org);
+		org++;
+		if (++col == maxcol) {
+			org = screen_pos(vc, pos, viewed);
+			col = 0;
+			pos += maxcol;
+		}
+	}
+
+	return org;
+}
+
+/*
+ * Compilers (gcc 10) are unable to optimize the swap in cpu_to_le16. So do it
+ * the poor man way.
+ */
+static inline u16 vc_compile_le16(u8 hi, u8 lo)
+{
+#ifdef __BIG_ENDIAN
+	return (lo << 8u) | hi;
+#else
+	return (hi << 8u) | lo;
+#endif
+}
+
+static u16 *vcs_write_buf(struct vc_data *vc, const char *con_buf,
+		unsigned int pos, unsigned int count, bool viewed, u16 **org0)
+{
+	u16 *org;
+	unsigned int col, maxcol = vc->vc_cols;
+	unsigned char c;
+
+	/* header */
+	if (pos < HEADER_SIZE) {
+		char header[HEADER_SIZE];
+
+		getconsxy(vc, header + 2);
+		while (pos < HEADER_SIZE && count > 0) {
+			count--;
+			header[pos++] = *con_buf++;
+		}
+		if (!viewed)
+			putconsxy(vc, header + 2);
+	}
+
+	if (!count)
+		return NULL;
+
+	pos -= HEADER_SIZE;
+	col = (pos/2) % maxcol;
+
+	*org0 = org = screen_pos(vc, pos/2, viewed);
+
+	/* odd pos -- the first single character */
+	if (pos & 1) {
+		count--;
+		c = *con_buf++;
+		vcs_scr_writew(vc, vc_compile_le16(c, vcs_scr_readw(vc, org)),
+				org);
+		org++;
+		pos++;
+		if (++col == maxcol) {
+			org = screen_pos(vc, pos/2, viewed);
+			col = 0;
+		}
+	}
+
+	pos /= 2;
+	pos += maxcol - col;
+
+	/* even pos -- handle attr+character pairs */
+	while (count > 1) {
+		unsigned short w;
+
+		w = get_unaligned(((unsigned short *)con_buf));
+		vcs_scr_writew(vc, w, org++);
+		con_buf += 2;
+		count -= 2;
+		if (++col == maxcol) {
+			org = screen_pos(vc, pos, viewed);
+			col = 0;
+			pos += maxcol;
+		}
+	}
+
+	if (!count)
+		return org;
+
+	/* odd pos -- the remaining character */
+	c = *con_buf++;
+	vcs_scr_writew(vc, vc_compile_le16(vcs_scr_readw(vc, org) >> 8, c),
+				org);
+
+	return org;
+}
+
+static ssize_t
+vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *inode = file_inode(file);
+	struct vc_data *vc;
+	char *con_buf;
+	u16 *org0, *org;
+	unsigned int written;
+	int size;
+	ssize_t ret;
+	loff_t pos;
+	bool viewed, attr;
+
+	if (use_unicode(inode))
+		return -EOPNOTSUPP;
+
+	con_buf = (char *) __get_free_page(GFP_KERNEL);
+	if (!con_buf)
+		return -ENOMEM;
+
+	pos = *ppos;
+
+	/* Select the proper current console and verify
+	 * sanity of the situation under the console lock.
+	 */
+	console_lock();
+
+	attr = use_attributes(inode);
+	ret = -ENXIO;
+	vc = vcs_vc(inode, &viewed);
+	if (!vc)
+		goto unlock_out;
+
+	size = vcs_size(vc, attr, false);
+	if (size < 0) {
+		ret = size;
+		goto unlock_out;
+	}
+	ret = -EINVAL;
+	if (pos < 0 || pos > size)
+		goto unlock_out;
+	if (count > size - pos)
+		count = size - pos;
+	written = 0;
+	while (count) {
+		unsigned int this_round = count;
+
+		if (this_round > CON_BUF_SIZE)
+			this_round = CON_BUF_SIZE;
+
+		/* Temporarily drop the console lock so that we can read
+		 * in the write data from userspace safely.
+		 */
+		console_unlock();
+		ret = copy_from_user(con_buf, buf, this_round);
+		console_lock();
+
+		if (ret) {
+			this_round -= ret;
+			if (!this_round) {
+				/* Abort loop if no data were copied. Otherwise
+				 * fail with -EFAULT.
+				 */
+				if (written)
+					break;
+				ret = -EFAULT;
+				goto unlock_out;
+			}
+		}
+
+		/* The vc might have been freed or vcs_size might have changed
+		 * while we slept to grab the user buffer, so recheck.
+		 * Return data written up to now on failure.
+		 */
+		vc = vcs_vc(inode, &viewed);
+		if (!vc) {
+			if (written)
+				break;
+			ret = -ENXIO;
+			goto unlock_out;
+		}
+		size = vcs_size(vc, attr, false);
+		if (size < 0) {
+			if (written)
+				break;
+			ret = size;
+			goto unlock_out;
+		}
+		if (pos >= size)
+			break;
+		if (this_round > size - pos)
+			this_round = size - pos;
+
+		/* OK, now actually push the write to the console
+		 * under the lock using the local kernel buffer.
+		 */
+
+		if (attr)
+			org = vcs_write_buf(vc, con_buf, pos, this_round,
+					viewed, &org0);
+		else
+			org = vcs_write_buf_noattr(vc, con_buf, pos, this_round,
+					viewed, &org0);
+
+		count -= this_round;
+		written += this_round;
+		buf += this_round;
+		pos += this_round;
+		if (org)
+			update_region(vc, (unsigned long)(org0), org - org0);
+	}
+	*ppos += written;
+	ret = written;
+	if (written)
+		vcs_scr_updated(vc);
+
+unlock_out:
+	console_unlock();
+	free_page((unsigned long) con_buf);
+	return ret;
+}
+
+static __poll_t
+vcs_poll(struct file *file, poll_table *wait)
+{
+	struct vcs_poll_data *poll = vcs_poll_data_get(file);
+	__poll_t ret = DEFAULT_POLLMASK|EPOLLERR;
+
+	if (poll) {
+		poll_wait(file, &poll->waitq, wait);
+		switch (poll->event) {
+		case VT_UPDATE:
+			ret = DEFAULT_POLLMASK|EPOLLPRI;
+			break;
+		case VT_DEALLOCATE:
+			ret = DEFAULT_POLLMASK|EPOLLHUP|EPOLLERR;
+			break;
+		case 0:
+			ret = DEFAULT_POLLMASK;
+			break;
+		}
+	}
+	return ret;
+}
+
+static int
+vcs_fasync(int fd, struct file *file, int on)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (!poll) {
+		/* don't allocate anything if all we want is disable fasync */
+		if (!on)
+			return 0;
+		poll = vcs_poll_data_get(file);
+		if (!poll)
+			return -ENOMEM;
+	}
+
+	return fasync_helper(fd, file, on, &poll->fasync);
+}
+
+static int
+vcs_open(struct inode *inode, struct file *filp)
+{
+	unsigned int currcons = console(inode);
+	bool attr = use_attributes(inode);
+	bool uni_mode = use_unicode(inode);
+	int ret = 0;
+
+	/* we currently don't support attributes in unicode mode */
+	if (attr && uni_mode)
+		return -EOPNOTSUPP;
+
+	console_lock();
+	if(currcons && !vc_cons_allocated(currcons-1))
+		ret = -ENXIO;
+	console_unlock();
+	return ret;
+}
+
+static int vcs_release(struct inode *inode, struct file *file)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (poll)
+		vcs_poll_data_free(poll);
+	return 0;
+}
+
+static const struct file_operations vcs_fops = {
+	.llseek		= vcs_lseek,
+	.read		= vcs_read,
+	.write		= vcs_write,
+	.poll		= vcs_poll,
+	.fasync		= vcs_fasync,
+	.open		= vcs_open,
+	.release	= vcs_release,
+};
+
+static struct class *vc_class;
+
+void vcs_make_sysfs(int index)
+{
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL,
+		      "vcs%u", index + 1);
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 65), NULL,
+		      "vcsu%u", index + 1);
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL,
+		      "vcsa%u", index + 1);
+}
+
+void vcs_remove_sysfs(int index)
+{
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1));
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 65));
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129));
+}
+
+int __init vcs_init(void)
+{
+	unsigned int i;
+
+	if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
+		panic("unable to get major %d for vcs device", VCS_MAJOR);
+	vc_class = class_create("vc");
+
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 64), NULL, "vcsu");
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
+	for (i = 0; i < MIN_NR_CONSOLES; i++)
+		vcs_make_sysfs(i);
+	return 0;
+}
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
new file mode 100644
index 000000000..5c47f7780
--- /dev/null
+++ b/drivers/tty/vt/vt.c
@@ -0,0 +1,4785 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * Hopefully this will be a rather complete VT102 implementation.
+ *
+ * Beeping thanks to John T Kohl.
+ *
+ * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
+ *   Chars, and VT100 enhancements by Peter MacDonald.
+ *
+ * Copy and paste function by Andrew Haylett,
+ *   some enhancements by Alessandro Rubini.
+ *
+ * Code to check for different video-cards mostly by Galen Hunt,
+ * <g-hunt@ee.utah.edu>
+ *
+ * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
+ * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
+ *
+ * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
+ * Resizing of consoles, aeb, 940926
+ *
+ * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
+ * <poe@daimi.aau.dk>
+ *
+ * User-defined bell sound, new setterm control sequences and printk
+ * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
+ *
+ * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
+ *
+ * Merge with the abstract console driver by Geert Uytterhoeven
+ * <geert@linux-m68k.org>, Jan 1997.
+ *
+ *   Original m68k console driver modifications by
+ *
+ *     - Arno Griffioen <arno@usn.nl>
+ *     - David Carter <carter@cs.bris.ac.uk>
+ * 
+ *   The abstract console driver provides a generic interface for a text
+ *   console. It supports VGA text mode, frame buffer based graphical consoles
+ *   and special graphics processors that are only accessible through some
+ *   registers (e.g. a TMS340x0 GSP).
+ *
+ *   The interface to the hardware is specified using a special structure
+ *   (struct consw) which contains function pointers to console operations
+ *   (see <linux/console.h> for more information).
+ *
+ * Support for changeable cursor shape
+ * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
+ *
+ * Ported to i386 and con_scrolldelta fixed
+ * by Emmanuel Marty <core@ggi-project.org>, April 1998
+ *
+ * Resurrected character buffers in videoram plus lots of other trickery
+ * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
+ *
+ * Removed old-style timers, introduced console_timer, made timer
+ * deletion SMP-safe.  17Jun00, Andrew Morton
+ *
+ * Removed console_lock, enabled interrupts across all console operations
+ * 13 March 2001, Andrew Morton
+ *
+ * Fixed UTF-8 mode so alternate charset modes always work according
+ * to control sequences interpreted in do_con_trol function
+ * preserving backward VT100 semigraphics compatibility,
+ * malformed UTF sequences represented as sequences of replacement glyphs,
+ * original codes or '?' as a last resort if replacement glyph is undefined
+ * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/sched/signal.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/kd.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/tiocl.h>
+#include <linux/kbd_kern.h>
+#include <linux/consolemap.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/pm.h>
+#include <linux/font.h>
+#include <linux/bitops.h>
+#include <linux/notifier.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/kdb.h>
+#include <linux/ctype.h>
+#include <linux/bsearch.h>
+#include <linux/gcd.h>
+
+#define MAX_NR_CON_DRIVER 16
+
+#define CON_DRIVER_FLAG_MODULE 1
+#define CON_DRIVER_FLAG_INIT   2
+#define CON_DRIVER_FLAG_ATTR   4
+#define CON_DRIVER_FLAG_ZOMBIE 8
+
+struct con_driver {
+	const struct consw *con;
+	const char *desc;
+	struct device *dev;
+	int node;
+	int first;
+	int last;
+	int flag;
+};
+
+static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
+const struct consw *conswitchp;
+
+/*
+ * Here is the default bell parameters: 750HZ, 1/8th of a second
+ */
+#define DEFAULT_BELL_PITCH	750
+#define DEFAULT_BELL_DURATION	(HZ/8)
+#define DEFAULT_CURSOR_BLINK_MS	200
+
+struct vc vc_cons [MAX_NR_CONSOLES];
+EXPORT_SYMBOL(vc_cons);
+
+static const struct consw *con_driver_map[MAX_NR_CONSOLES];
+
+static int con_open(struct tty_struct *, struct file *);
+static void vc_init(struct vc_data *vc, int do_clear);
+static void gotoxy(struct vc_data *vc, int new_x, int new_y);
+static void save_cur(struct vc_data *vc);
+static void reset_terminal(struct vc_data *vc, int do_clear);
+static void con_flush_chars(struct tty_struct *tty);
+static int set_vesa_blanking(char __user *p);
+static void set_cursor(struct vc_data *vc);
+static void hide_cursor(struct vc_data *vc);
+static void console_callback(struct work_struct *ignored);
+static void con_driver_unregister_callback(struct work_struct *ignored);
+static void blank_screen_t(struct timer_list *unused);
+static void set_palette(struct vc_data *vc);
+static void unblank_screen(void);
+
+#define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
+
+int default_utf8 = true;
+module_param(default_utf8, int, S_IRUGO | S_IWUSR);
+int global_cursor_default = -1;
+module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(global_cursor_default);
+
+static int cur_default = CUR_UNDERLINE;
+module_param(cur_default, int, S_IRUGO | S_IWUSR);
+
+/*
+ * ignore_poke: don't unblank the screen when things are typed.  This is
+ * mainly for the privacy of braille terminal users.
+ */
+static int ignore_poke;
+
+int do_poke_blanked_console;
+int console_blanked;
+EXPORT_SYMBOL(console_blanked);
+
+static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
+static int vesa_off_interval;
+static int blankinterval;
+core_param(consoleblank, blankinterval, int, 0444);
+
+static DECLARE_WORK(console_work, console_callback);
+static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
+
+/*
+ * fg_console is the current virtual console,
+ * last_console is the last used one,
+ * want_console is the console we want to switch to,
+ * saved_* variants are for save/restore around kernel debugger enter/leave
+ */
+int fg_console;
+EXPORT_SYMBOL(fg_console);
+int last_console;
+int want_console = -1;
+
+static int saved_fg_console;
+static int saved_last_console;
+static int saved_want_console;
+static int saved_vc_mode;
+static int saved_console_blanked;
+
+/*
+ * For each existing display, we have a pointer to console currently visible
+ * on that display, allowing consoles other than fg_console to be refreshed
+ * appropriately. Unless the low-level driver supplies its own display_fg
+ * variable, we use this one for the "master display".
+ */
+static struct vc_data *master_display_fg;
+
+/*
+ * Unfortunately, we need to delay tty echo when we're currently writing to the
+ * console since the code is (and always was) not re-entrant, so we schedule
+ * all flip requests to process context with schedule-task() and run it from
+ * console_callback().
+ */
+
+/*
+ * For the same reason, we defer scrollback to the console callback.
+ */
+static int scrollback_delta;
+
+/*
+ * Hook so that the power management routines can (un)blank
+ * the console on our behalf.
+ */
+int (*console_blank_hook)(int);
+EXPORT_SYMBOL(console_blank_hook);
+
+static DEFINE_TIMER(console_timer, blank_screen_t);
+static int blank_state;
+static int blank_timer_expired;
+enum {
+	blank_off = 0,
+	blank_normal_wait,
+	blank_vesa_wait,
+};
+
+/*
+ * /sys/class/tty/tty0/
+ *
+ * the attribute 'active' contains the name of the current vc
+ * console and it supports poll() to detect vc switches
+ */
+static struct device *tty0dev;
+
+/*
+ * Notifier list for console events.
+ */
+static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
+
+int register_vt_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&vt_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_vt_notifier);
+
+int unregister_vt_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_vt_notifier);
+
+static void notify_write(struct vc_data *vc, unsigned int unicode)
+{
+	struct vt_notifier_param param = { .vc = vc, .c = unicode };
+	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
+}
+
+static void notify_update(struct vc_data *vc)
+{
+	struct vt_notifier_param param = { .vc = vc };
+	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
+}
+/*
+ *	Low-Level Functions
+ */
+
+static inline bool con_is_fg(const struct vc_data *vc)
+{
+	return vc->vc_num == fg_console;
+}
+
+static inline bool con_should_update(const struct vc_data *vc)
+{
+	return con_is_visible(vc) && !console_blanked;
+}
+
+static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
+		bool viewed)
+{
+	unsigned short *p;
+	
+	if (!viewed)
+		p = (unsigned short *)(vc->vc_origin + offset);
+	else if (!vc->vc_sw->con_screen_pos)
+		p = (unsigned short *)(vc->vc_visible_origin + offset);
+	else
+		p = vc->vc_sw->con_screen_pos(vc, offset);
+	return p;
+}
+
+/* Called  from the keyboard irq path.. */
+static inline void scrolldelta(int lines)
+{
+	/* FIXME */
+	/* scrolldelta needs some kind of consistency lock, but the BKL was
+	   and still is not protecting versus the scheduled back end */
+	scrollback_delta += lines;
+	schedule_console_callback();
+}
+
+void schedule_console_callback(void)
+{
+	schedule_work(&console_work);
+}
+
+/*
+ * Code to manage unicode-based screen buffers
+ */
+
+/*
+ * Our screen buffer is preceded by an array of line pointers so that
+ * scrolling only implies some pointer shuffling.
+ */
+
+static u32 **vc_uniscr_alloc(unsigned int cols, unsigned int rows)
+{
+	u32 **uni_lines;
+	void *p;
+	unsigned int memsize, i, col_size = cols * sizeof(**uni_lines);
+
+	/* allocate everything in one go */
+	memsize = col_size * rows;
+	memsize += rows * sizeof(*uni_lines);
+	uni_lines = vzalloc(memsize);
+	if (!uni_lines)
+		return NULL;
+
+	/* initial line pointers */
+	p = uni_lines + rows;
+	for (i = 0; i < rows; i++) {
+		uni_lines[i] = p;
+		p += col_size;
+	}
+
+	return uni_lines;
+}
+
+static void vc_uniscr_free(u32 **uni_lines)
+{
+	vfree(uni_lines);
+}
+
+static void vc_uniscr_set(struct vc_data *vc, u32 **new_uni_lines)
+{
+	vc_uniscr_free(vc->vc_uni_lines);
+	vc->vc_uni_lines = new_uni_lines;
+}
+
+static void vc_uniscr_putc(struct vc_data *vc, u32 uc)
+{
+	if (vc->vc_uni_lines)
+		vc->vc_uni_lines[vc->state.y][vc->state.x] = uc;
+}
+
+static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
+{
+	if (vc->vc_uni_lines) {
+		u32 *ln = vc->vc_uni_lines[vc->state.y];
+		unsigned int x = vc->state.x, cols = vc->vc_cols;
+
+		memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
+		memset32(&ln[x], ' ', nr);
+	}
+}
+
+static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
+{
+	if (vc->vc_uni_lines) {
+		u32 *ln = vc->vc_uni_lines[vc->state.y];
+		unsigned int x = vc->state.x, cols = vc->vc_cols;
+
+		memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
+		memset32(&ln[cols - nr], ' ', nr);
+	}
+}
+
+static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
+				 unsigned int nr)
+{
+	if (vc->vc_uni_lines)
+		memset32(&vc->vc_uni_lines[vc->state.y][x], ' ', nr);
+}
+
+static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
+				  unsigned int nr)
+{
+	if (vc->vc_uni_lines)
+		while (nr--)
+			memset32(vc->vc_uni_lines[y++], ' ', vc->vc_cols);
+}
+
+/* juggling array rotation algorithm (complexity O(N), size complexity O(1)) */
+static void juggle_array(u32 **array, unsigned int size, unsigned int nr)
+{
+	unsigned int gcd_idx;
+
+	for (gcd_idx = 0; gcd_idx < gcd(nr, size); gcd_idx++) {
+		u32 *gcd_idx_val = array[gcd_idx];
+		unsigned int dst_idx = gcd_idx;
+
+		while (1) {
+			unsigned int src_idx = (dst_idx + nr) % size;
+			if (src_idx == gcd_idx)
+				break;
+
+			array[dst_idx] = array[src_idx];
+			dst_idx = src_idx;
+		}
+
+		array[dst_idx] = gcd_idx_val;
+	}
+}
+
+static void vc_uniscr_scroll(struct vc_data *vc, unsigned int top,
+			     unsigned int bottom, enum con_scroll dir,
+			     unsigned int nr)
+{
+	u32 **uni_lines = vc->vc_uni_lines;
+	unsigned int size = bottom - top;
+
+	if (!uni_lines)
+		return;
+
+	if (dir == SM_DOWN) {
+		juggle_array(&uni_lines[top], size, size - nr);
+		vc_uniscr_clear_lines(vc, top, nr);
+	} else {
+		juggle_array(&uni_lines[top], size, nr);
+		vc_uniscr_clear_lines(vc, bottom - nr, nr);
+	}
+}
+
+static void vc_uniscr_copy_area(u32 **dst_lines,
+				unsigned int dst_cols,
+				unsigned int dst_rows,
+				u32 **src_lines,
+				unsigned int src_cols,
+				unsigned int src_top_row,
+				unsigned int src_bot_row)
+{
+	unsigned int dst_row = 0;
+
+	if (!dst_lines)
+		return;
+
+	while (src_top_row < src_bot_row) {
+		u32 *src_line = src_lines[src_top_row];
+		u32 *dst_line = dst_lines[dst_row];
+
+		memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
+		if (dst_cols - src_cols)
+			memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
+		src_top_row++;
+		dst_row++;
+	}
+	while (dst_row < dst_rows) {
+		u32 *dst_line = dst_lines[dst_row];
+
+		memset32(dst_line, ' ', dst_cols);
+		dst_row++;
+	}
+}
+
+/*
+ * Called from vcs_read() to make sure unicode screen retrieval is possible.
+ * This will initialize the unicode screen buffer if not already done.
+ * This returns 0 if OK, or a negative error code otherwise.
+ * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
+ */
+int vc_uniscr_check(struct vc_data *vc)
+{
+	u32 **uni_lines;
+	unsigned short *p;
+	int x, y, mask;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc->vc_utf)
+		return -ENODATA;
+
+	if (vc->vc_uni_lines)
+		return 0;
+
+	uni_lines = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
+	if (!uni_lines)
+		return -ENOMEM;
+
+	/*
+	 * Let's populate it initially with (imperfect) reverse translation.
+	 * This is the next best thing we can do short of having it enabled
+	 * from the start even when no users rely on this functionality. True
+	 * unicode content will be available after a complete screen refresh.
+	 */
+	p = (unsigned short *)vc->vc_origin;
+	mask = vc->vc_hi_font_mask | 0xff;
+	for (y = 0; y < vc->vc_rows; y++) {
+		u32 *line = uni_lines[y];
+		for (x = 0; x < vc->vc_cols; x++) {
+			u16 glyph = scr_readw(p++) & mask;
+			line[x] = inverse_translate(vc, glyph, true);
+		}
+	}
+
+	vc->vc_uni_lines = uni_lines;
+
+	return 0;
+}
+
+/*
+ * Called from vcs_read() to get the unicode data from the screen.
+ * This must be preceded by a successful call to vc_uniscr_check() once
+ * the console lock has been taken.
+ */
+void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
+			 unsigned int row, unsigned int col, unsigned int nr)
+{
+	u32 **uni_lines = vc->vc_uni_lines;
+	int offset = row * vc->vc_size_row + col * 2;
+	unsigned long pos;
+
+	if (WARN_ON_ONCE(!uni_lines))
+		return;
+
+	pos = (unsigned long)screenpos(vc, offset, viewed);
+	if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
+		/*
+		 * Desired position falls in the main screen buffer.
+		 * However the actual row/col might be different if
+		 * scrollback is active.
+		 */
+		row = (pos - vc->vc_origin) / vc->vc_size_row;
+		col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
+		memcpy(dest, &uni_lines[row][col], nr * sizeof(u32));
+	} else {
+		/*
+		 * Scrollback is active. For now let's simply backtranslate
+		 * the screen glyphs until the unicode screen buffer does
+		 * synchronize with console display drivers for a scrollback
+		 * buffer of its own.
+		 */
+		u16 *p = (u16 *)pos;
+		int mask = vc->vc_hi_font_mask | 0xff;
+		u32 *uni_buf = dest;
+		while (nr--) {
+			u16 glyph = scr_readw(p++) & mask;
+			*uni_buf++ = inverse_translate(vc, glyph, true);
+		}
+	}
+}
+
+static void con_scroll(struct vc_data *vc, unsigned int top,
+		       unsigned int bottom, enum con_scroll dir,
+		       unsigned int nr)
+{
+	unsigned int rows = bottom - top;
+	u16 *clear, *dst, *src;
+
+	if (top + nr >= bottom)
+		nr = rows - 1;
+	if (bottom > vc->vc_rows || top >= bottom || nr < 1)
+		return;
+
+	vc_uniscr_scroll(vc, top, bottom, dir, nr);
+	if (con_is_visible(vc) &&
+			vc->vc_sw->con_scroll(vc, top, bottom, dir, nr))
+		return;
+
+	src = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * top);
+	dst = (u16 *)(vc->vc_origin + vc->vc_size_row * (top + nr));
+
+	if (dir == SM_UP) {
+		clear = src + (rows - nr) * vc->vc_cols;
+		swap(src, dst);
+	}
+	scr_memmovew(dst, src, (rows - nr) * vc->vc_size_row);
+	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
+}
+
+static void do_update_region(struct vc_data *vc, unsigned long start, int count)
+{
+	unsigned int xx, yy, offset;
+	u16 *p;
+
+	p = (u16 *) start;
+	if (!vc->vc_sw->con_getxy) {
+		offset = (start - vc->vc_origin) / 2;
+		xx = offset % vc->vc_cols;
+		yy = offset / vc->vc_cols;
+	} else {
+		int nxx, nyy;
+		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
+		xx = nxx; yy = nyy;
+	}
+	for(;;) {
+		u16 attrib = scr_readw(p) & 0xff00;
+		int startx = xx;
+		u16 *q = p;
+		while (xx < vc->vc_cols && count) {
+			if (attrib != (scr_readw(p) & 0xff00)) {
+				if (p > q)
+					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
+				startx = xx;
+				q = p;
+				attrib = scr_readw(p) & 0xff00;
+			}
+			p++;
+			xx++;
+			count--;
+		}
+		if (p > q)
+			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
+		if (!count)
+			break;
+		xx = 0;
+		yy++;
+		if (vc->vc_sw->con_getxy) {
+			p = (u16 *)start;
+			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
+		}
+	}
+}
+
+void update_region(struct vc_data *vc, unsigned long start, int count)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (con_should_update(vc)) {
+		hide_cursor(vc);
+		do_update_region(vc, start, count);
+		set_cursor(vc);
+	}
+}
+EXPORT_SYMBOL(update_region);
+
+/* Structure of attributes is hardware-dependent */
+
+static u8 build_attr(struct vc_data *vc, u8 _color,
+		enum vc_intensity _intensity, bool _blink, bool _underline,
+		bool _reverse, bool _italic)
+{
+	if (vc->vc_sw->con_build_attr)
+		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
+		       _blink, _underline, _reverse, _italic);
+
+/*
+ * ++roman: I completely changed the attribute format for monochrome
+ * mode (!can_do_color). The formerly used MDA (monochrome display
+ * adapter) format didn't allow the combination of certain effects.
+ * Now the attribute is just a bit vector:
+ *  Bit 0..1: intensity (0..2)
+ *  Bit 2   : underline
+ *  Bit 3   : reverse
+ *  Bit 7   : blink
+ */
+	{
+	u8 a = _color;
+	if (!vc->vc_can_do_color)
+		return _intensity |
+		       (_italic    << 1) |
+		       (_underline << 2) |
+		       (_reverse   << 3) |
+		       (_blink     << 7);
+	if (_italic)
+		a = (a & 0xF0) | vc->vc_itcolor;
+	else if (_underline)
+		a = (a & 0xf0) | vc->vc_ulcolor;
+	else if (_intensity == VCI_HALF_BRIGHT)
+		a = (a & 0xf0) | vc->vc_halfcolor;
+	if (_reverse)
+		a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
+	if (_blink)
+		a ^= 0x80;
+	if (_intensity == VCI_BOLD)
+		a ^= 0x08;
+	if (vc->vc_hi_font_mask == 0x100)
+		a <<= 1;
+	return a;
+	}
+}
+
+static void update_attr(struct vc_data *vc)
+{
+	vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
+	              vc->state.blink, vc->state.underline,
+	              vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
+	vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
+				VCI_NORMAL, vc->state.blink, false,
+				vc->vc_decscnm, false) << 8);
+}
+
+/* Note: inverting the screen twice should revert to the original state */
+void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
+{
+	unsigned short *p;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	count /= 2;
+	p = screenpos(vc, offset, viewed);
+	if (vc->vc_sw->con_invert_region) {
+		vc->vc_sw->con_invert_region(vc, p, count);
+	} else {
+		u16 *q = p;
+		int cnt = count;
+		u16 a;
+
+		if (!vc->vc_can_do_color) {
+			while (cnt--) {
+			    a = scr_readw(q);
+			    a ^= 0x0800;
+			    scr_writew(a, q);
+			    q++;
+			}
+		} else if (vc->vc_hi_font_mask == 0x100) {
+			while (cnt--) {
+				a = scr_readw(q);
+				a = (a & 0x11ff) |
+				   ((a & 0xe000) >> 4) |
+				   ((a & 0x0e00) << 4);
+				scr_writew(a, q);
+				q++;
+			}
+		} else {
+			while (cnt--) {
+				a = scr_readw(q);
+				a = (a & 0x88ff) |
+				   ((a & 0x7000) >> 4) |
+				   ((a & 0x0700) << 4);
+				scr_writew(a, q);
+				q++;
+			}
+		}
+	}
+
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) p, count);
+	notify_update(vc);
+}
+
+/* used by selection: complement pointer position */
+void complement_pos(struct vc_data *vc, int offset)
+{
+	static int old_offset = -1;
+	static unsigned short old;
+	static unsigned short oldx, oldy;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (old_offset != -1 && old_offset >= 0 &&
+	    old_offset < vc->vc_screenbuf_size) {
+		scr_writew(old, screenpos(vc, old_offset, true));
+		if (con_should_update(vc))
+			vc->vc_sw->con_putc(vc, old, oldy, oldx);
+		notify_update(vc);
+	}
+
+	old_offset = offset;
+
+	if (offset != -1 && offset >= 0 &&
+	    offset < vc->vc_screenbuf_size) {
+		unsigned short new;
+		unsigned short *p;
+		p = screenpos(vc, offset, true);
+		old = scr_readw(p);
+		new = old ^ vc->vc_complement_mask;
+		scr_writew(new, p);
+		if (con_should_update(vc)) {
+			oldx = (offset >> 1) % vc->vc_cols;
+			oldy = (offset >> 1) / vc->vc_cols;
+			vc->vc_sw->con_putc(vc, new, oldy, oldx);
+		}
+		notify_update(vc);
+	}
+}
+
+static void insert_char(struct vc_data *vc, unsigned int nr)
+{
+	unsigned short *p = (unsigned short *) vc->vc_pos;
+
+	vc_uniscr_insert(vc, nr);
+	scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
+	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
+	vc->vc_need_wrap = 0;
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) p,
+			vc->vc_cols - vc->state.x);
+}
+
+static void delete_char(struct vc_data *vc, unsigned int nr)
+{
+	unsigned short *p = (unsigned short *) vc->vc_pos;
+
+	vc_uniscr_delete(vc, nr);
+	scr_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
+	scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
+			nr * 2);
+	vc->vc_need_wrap = 0;
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) p,
+			vc->vc_cols - vc->state.x);
+}
+
+static int softcursor_original = -1;
+
+static void add_softcursor(struct vc_data *vc)
+{
+	int i = scr_readw((u16 *) vc->vc_pos);
+	u32 type = vc->vc_cursor_type;
+
+	if (!(type & CUR_SW))
+		return;
+	if (softcursor_original != -1)
+		return;
+	softcursor_original = i;
+	i |= CUR_SET(type);
+	i ^= CUR_CHANGE(type);
+	if ((type & CUR_ALWAYS_BG) &&
+			(softcursor_original & CUR_BG) == (i & CUR_BG))
+		i ^= CUR_BG;
+	if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
+		i ^= CUR_FG;
+	scr_writew(i, (u16 *)vc->vc_pos);
+	if (con_should_update(vc))
+		vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
+}
+
+static void hide_softcursor(struct vc_data *vc)
+{
+	if (softcursor_original != -1) {
+		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
+		if (con_should_update(vc))
+			vc->vc_sw->con_putc(vc, softcursor_original,
+					vc->state.y, vc->state.x);
+		softcursor_original = -1;
+	}
+}
+
+static void hide_cursor(struct vc_data *vc)
+{
+	if (vc_is_sel(vc))
+		clear_selection();
+
+	vc->vc_sw->con_cursor(vc, CM_ERASE);
+	hide_softcursor(vc);
+}
+
+static void set_cursor(struct vc_data *vc)
+{
+	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
+		return;
+	if (vc->vc_deccm) {
+		if (vc_is_sel(vc))
+			clear_selection();
+		add_softcursor(vc);
+		if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
+			vc->vc_sw->con_cursor(vc, CM_DRAW);
+	} else
+		hide_cursor(vc);
+}
+
+static void set_origin(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!con_is_visible(vc) ||
+	    !vc->vc_sw->con_set_origin ||
+	    !vc->vc_sw->con_set_origin(vc))
+		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
+	vc->vc_visible_origin = vc->vc_origin;
+	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
+	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
+		2 * vc->state.x;
+}
+
+static void save_screen(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc->vc_sw->con_save_screen)
+		vc->vc_sw->con_save_screen(vc);
+}
+
+static void flush_scrollback(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	set_origin(vc);
+	if (vc->vc_sw->con_flush_scrollback) {
+		vc->vc_sw->con_flush_scrollback(vc);
+	} else if (con_is_visible(vc)) {
+		/*
+		 * When no con_flush_scrollback method is provided then the
+		 * legacy way for flushing the scrollback buffer is to use
+		 * a side effect of the con_switch method. We do it only on
+		 * the foreground console as background consoles have no
+		 * scrollback buffers in that case and we obviously don't
+		 * want to switch to them.
+		 */
+		hide_cursor(vc);
+		vc->vc_sw->con_switch(vc);
+		set_cursor(vc);
+	}
+}
+
+/*
+ *	Redrawing of screen
+ */
+
+void clear_buffer_attributes(struct vc_data *vc)
+{
+	unsigned short *p = (unsigned short *)vc->vc_origin;
+	int count = vc->vc_screenbuf_size / 2;
+	int mask = vc->vc_hi_font_mask | 0xff;
+
+	for (; count > 0; count--, p++) {
+		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
+	}
+}
+
+void redraw_screen(struct vc_data *vc, int is_switch)
+{
+	int redraw = 0;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc) {
+		/* strange ... */
+		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
+		return;
+	}
+
+	if (is_switch) {
+		struct vc_data *old_vc = vc_cons[fg_console].d;
+		if (old_vc == vc)
+			return;
+		if (!con_is_visible(vc))
+			redraw = 1;
+		*vc->vc_display_fg = vc;
+		fg_console = vc->vc_num;
+		hide_cursor(old_vc);
+		if (!con_is_visible(old_vc)) {
+			save_screen(old_vc);
+			set_origin(old_vc);
+		}
+		if (tty0dev)
+			sysfs_notify(&tty0dev->kobj, NULL, "active");
+	} else {
+		hide_cursor(vc);
+		redraw = 1;
+	}
+
+	if (redraw) {
+		int update;
+		int old_was_color = vc->vc_can_do_color;
+
+		set_origin(vc);
+		update = vc->vc_sw->con_switch(vc);
+		set_palette(vc);
+		/*
+		 * If console changed from mono<->color, the best we can do
+		 * is to clear the buffer attributes. As it currently stands,
+		 * rebuilding new attributes from the old buffer is not doable
+		 * without overly complex code.
+		 */
+		if (old_was_color != vc->vc_can_do_color) {
+			update_attr(vc);
+			clear_buffer_attributes(vc);
+		}
+
+		if (update && vc->vc_mode != KD_GRAPHICS)
+			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
+	}
+	set_cursor(vc);
+	if (is_switch) {
+		vt_set_leds_compute_shiftstate();
+		notify_update(vc);
+	}
+}
+EXPORT_SYMBOL(redraw_screen);
+
+/*
+ *	Allocation, freeing and resizing of VTs.
+ */
+
+int vc_cons_allocated(unsigned int i)
+{
+	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
+}
+
+static void visual_init(struct vc_data *vc, int num, int init)
+{
+	/* ++Geert: vc->vc_sw->con_init determines console size */
+	if (vc->vc_sw)
+		module_put(vc->vc_sw->owner);
+	vc->vc_sw = conswitchp;
+
+	if (con_driver_map[num])
+		vc->vc_sw = con_driver_map[num];
+
+	__module_get(vc->vc_sw->owner);
+	vc->vc_num = num;
+	vc->vc_display_fg = &master_display_fg;
+	if (vc->uni_pagedict_loc)
+		con_free_unimap(vc);
+	vc->uni_pagedict_loc = &vc->uni_pagedict;
+	vc->uni_pagedict = NULL;
+	vc->vc_hi_font_mask = 0;
+	vc->vc_complement_mask = 0;
+	vc->vc_can_do_color = 0;
+	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+	vc->vc_sw->con_init(vc, init);
+	if (!vc->vc_complement_mask)
+		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
+	vc->vc_s_complement_mask = vc->vc_complement_mask;
+	vc->vc_size_row = vc->vc_cols << 1;
+	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
+}
+
+
+static void visual_deinit(struct vc_data *vc)
+{
+	vc->vc_sw->con_deinit(vc);
+	module_put(vc->vc_sw->owner);
+}
+
+static void vc_port_destruct(struct tty_port *port)
+{
+	struct vc_data *vc = container_of(port, struct vc_data, port);
+
+	kfree(vc);
+}
+
+static const struct tty_port_operations vc_port_ops = {
+	.destruct = vc_port_destruct,
+};
+
+/*
+ * Change # of rows and columns (0 means unchanged/the size of fg_console)
+ * [this is to be used together with some user program
+ * like resize that changes the hardware videomode]
+ */
+#define VC_MAXCOL (32767)
+#define VC_MAXROW (32767)
+
+int vc_allocate(unsigned int currcons)	/* return 0 on success */
+{
+	struct vt_notifier_param param;
+	struct vc_data *vc;
+	int err;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (currcons >= MAX_NR_CONSOLES)
+		return -ENXIO;
+
+	if (vc_cons[currcons].d)
+		return 0;
+
+	/* due to the granularity of kmalloc, we waste some memory here */
+	/* the alloc is done in two steps, to optimize the common situation
+	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
+	/* although the numbers above are not valid since long ago, the
+	   point is still up-to-date and the comment still has its value
+	   even if only as a historical artifact.  --mj, July 1998 */
+	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
+	if (!vc)
+		return -ENOMEM;
+
+	vc_cons[currcons].d = vc;
+	tty_port_init(&vc->port);
+	vc->port.ops = &vc_port_ops;
+	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+
+	visual_init(vc, currcons, 1);
+
+	if (!*vc->uni_pagedict_loc)
+		con_set_default_unimap(vc);
+
+	err = -EINVAL;
+	if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
+	    vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
+		goto err_free;
+	err = -ENOMEM;
+	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
+	if (!vc->vc_screenbuf)
+		goto err_free;
+
+	/* If no drivers have overridden us and the user didn't pass a
+	   boot option, default to displaying the cursor */
+	if (global_cursor_default == -1)
+		global_cursor_default = 1;
+
+	vc_init(vc, 1);
+	vcs_make_sysfs(currcons);
+	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
+
+	return 0;
+err_free:
+	visual_deinit(vc);
+	kfree(vc);
+	vc_cons[currcons].d = NULL;
+	return err;
+}
+
+static inline int resize_screen(struct vc_data *vc, int width, int height,
+				int user)
+{
+	/* Resizes the resolution of the display adapater */
+	int err = 0;
+
+	if (vc->vc_sw->con_resize)
+		err = vc->vc_sw->con_resize(vc, width, height, user);
+
+	return err;
+}
+
+/**
+ *	vc_do_resize	-	resizing method for the tty
+ *	@tty: tty being resized
+ *	@vc: virtual console private data
+ *	@cols: columns
+ *	@lines: lines
+ *
+ *	Resize a virtual console, clipping according to the actual constraints.
+ *	If the caller passes a tty structure then update the termios winsize
+ *	information and perform any necessary signal handling.
+ *
+ *	Caller must hold the console semaphore. Takes the termios rwsem and
+ *	ctrl.lock of the tty IFF a tty is passed.
+ */
+
+static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
+				unsigned int cols, unsigned int lines)
+{
+	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
+	unsigned long end;
+	unsigned int old_rows, old_row_size, first_copied_row;
+	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
+	unsigned int user;
+	unsigned short *oldscreen, *newscreen;
+	u32 **new_uniscr = NULL;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc)
+		return -ENXIO;
+
+	user = vc->vc_resize_user;
+	vc->vc_resize_user = 0;
+
+	if (cols > VC_MAXCOL || lines > VC_MAXROW)
+		return -EINVAL;
+
+	new_cols = (cols ? cols : vc->vc_cols);
+	new_rows = (lines ? lines : vc->vc_rows);
+	new_row_size = new_cols << 1;
+	new_screen_size = new_row_size * new_rows;
+
+	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
+		/*
+		 * This function is being called here to cover the case
+		 * where the userspace calls the FBIOPUT_VSCREENINFO twice,
+		 * passing the same fb_var_screeninfo containing the fields
+		 * yres/xres equal to a number non-multiple of vc_font.height
+		 * and yres_virtual/xres_virtual equal to number lesser than the
+		 * vc_font.height and yres/xres.
+		 * In the second call, the struct fb_var_screeninfo isn't
+		 * being modified by the underlying driver because of the
+		 * if above, and this causes the fbcon_display->vrows to become
+		 * negative and it eventually leads to out-of-bound
+		 * access by the imageblit function.
+		 * To give the correct values to the struct and to not have
+		 * to deal with possible errors from the code below, we call
+		 * the resize_screen here as well.
+		 */
+		return resize_screen(vc, new_cols, new_rows, user);
+	}
+
+	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
+		return -EINVAL;
+	newscreen = kzalloc(new_screen_size, GFP_USER);
+	if (!newscreen)
+		return -ENOMEM;
+
+	if (vc->vc_uni_lines) {
+		new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
+		if (!new_uniscr) {
+			kfree(newscreen);
+			return -ENOMEM;
+		}
+	}
+
+	if (vc_is_sel(vc))
+		clear_selection();
+
+	old_rows = vc->vc_rows;
+	old_row_size = vc->vc_size_row;
+
+	err = resize_screen(vc, new_cols, new_rows, user);
+	if (err) {
+		kfree(newscreen);
+		vc_uniscr_free(new_uniscr);
+		return err;
+	}
+
+	vc->vc_rows = new_rows;
+	vc->vc_cols = new_cols;
+	vc->vc_size_row = new_row_size;
+	vc->vc_screenbuf_size = new_screen_size;
+
+	rlth = min(old_row_size, new_row_size);
+	rrem = new_row_size - rlth;
+	old_origin = vc->vc_origin;
+	new_origin = (long) newscreen;
+	new_scr_end = new_origin + new_screen_size;
+
+	if (vc->state.y > new_rows) {
+		if (old_rows - vc->state.y < new_rows) {
+			/*
+			 * Cursor near the bottom, copy contents from the
+			 * bottom of buffer
+			 */
+			first_copied_row = (old_rows - new_rows);
+		} else {
+			/*
+			 * Cursor is in no man's land, copy 1/2 screenful
+			 * from the top and bottom of cursor position
+			 */
+			first_copied_row = (vc->state.y - new_rows/2);
+		}
+		old_origin += first_copied_row * old_row_size;
+	} else
+		first_copied_row = 0;
+	end = old_origin + old_row_size * min(old_rows, new_rows);
+
+	vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
+			    vc->vc_uni_lines, rlth/2, first_copied_row,
+			    min(old_rows, new_rows));
+	vc_uniscr_set(vc, new_uniscr);
+
+	update_attr(vc);
+
+	while (old_origin < end) {
+		scr_memcpyw((unsigned short *) new_origin,
+			    (unsigned short *) old_origin, rlth);
+		if (rrem)
+			scr_memsetw((void *)(new_origin + rlth),
+				    vc->vc_video_erase_char, rrem);
+		old_origin += old_row_size;
+		new_origin += new_row_size;
+	}
+	if (new_scr_end > new_origin)
+		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
+			    new_scr_end - new_origin);
+	oldscreen = vc->vc_screenbuf;
+	vc->vc_screenbuf = newscreen;
+	vc->vc_screenbuf_size = new_screen_size;
+	set_origin(vc);
+	kfree(oldscreen);
+
+	/* do part of a reset_terminal() */
+	vc->vc_top = 0;
+	vc->vc_bottom = vc->vc_rows;
+	gotoxy(vc, vc->state.x, vc->state.y);
+	save_cur(vc);
+
+	if (tty) {
+		/* Rewrite the requested winsize data with the actual
+		   resulting sizes */
+		struct winsize ws;
+		memset(&ws, 0, sizeof(ws));
+		ws.ws_row = vc->vc_rows;
+		ws.ws_col = vc->vc_cols;
+		ws.ws_ypixel = vc->vc_scan_lines;
+		tty_do_resize(tty, &ws);
+	}
+
+	if (con_is_visible(vc))
+		update_screen(vc);
+	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
+	notify_update(vc);
+	return err;
+}
+
+/**
+ *	vc_resize		-	resize a VT
+ *	@vc: virtual console
+ *	@cols: columns
+ *	@rows: rows
+ *
+ *	Resize a virtual console as seen from the console end of things. We
+ *	use the common vc_do_resize methods to update the structures. The
+ *	caller must hold the console sem to protect console internals and
+ *	vc->port.tty
+ */
+
+int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
+{
+	return vc_do_resize(vc->port.tty, vc, cols, rows);
+}
+EXPORT_SYMBOL(vc_resize);
+
+/**
+ *	vt_resize		-	resize a VT
+ *	@tty: tty to resize
+ *	@ws: winsize attributes
+ *
+ *	Resize a virtual terminal. This is called by the tty layer as we
+ *	register our own handler for resizing. The mutual helper does all
+ *	the actual work.
+ *
+ *	Takes the console sem and the called methods then take the tty
+ *	termios_rwsem and the tty ctrl.lock in that order.
+ */
+static int vt_resize(struct tty_struct *tty, struct winsize *ws)
+{
+	struct vc_data *vc = tty->driver_data;
+	int ret;
+
+	console_lock();
+	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
+	console_unlock();
+	return ret;
+}
+
+struct vc_data *vc_deallocate(unsigned int currcons)
+{
+	struct vc_data *vc = NULL;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc_cons_allocated(currcons)) {
+		struct vt_notifier_param param;
+
+		param.vc = vc = vc_cons[currcons].d;
+		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
+		vcs_remove_sysfs(currcons);
+		visual_deinit(vc);
+		con_free_unimap(vc);
+		put_pid(vc->vt_pid);
+		vc_uniscr_set(vc, NULL);
+		kfree(vc->vc_screenbuf);
+		vc_cons[currcons].d = NULL;
+	}
+	return vc;
+}
+
+/*
+ *	VT102 emulator
+ */
+
+enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
+
+#define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
+#define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
+#define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
+
+#define decarm		VC_REPEAT
+#define decckm		VC_CKMODE
+#define kbdapplic	VC_APPLIC
+#define lnm		VC_CRLF
+
+const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
+				       8,12,10,14, 9,13,11,15 };
+EXPORT_SYMBOL(color_table);
+
+/* the default colour table, for VGA+ colour systems */
+unsigned char default_red[] = {
+	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
+	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
+};
+module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(default_red);
+
+unsigned char default_grn[] = {
+	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
+	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
+};
+module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(default_grn);
+
+unsigned char default_blu[] = {
+	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
+	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
+};
+module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(default_blu);
+
+/*
+ * gotoxy() must verify all boundaries, because the arguments
+ * might also be negative. If the given position is out of
+ * bounds, the cursor is placed at the nearest margin.
+ */
+static void gotoxy(struct vc_data *vc, int new_x, int new_y)
+{
+	int min_y, max_y;
+
+	if (new_x < 0)
+		vc->state.x = 0;
+	else {
+		if (new_x >= vc->vc_cols)
+			vc->state.x = vc->vc_cols - 1;
+		else
+			vc->state.x = new_x;
+	}
+
+ 	if (vc->vc_decom) {
+		min_y = vc->vc_top;
+		max_y = vc->vc_bottom;
+	} else {
+		min_y = 0;
+		max_y = vc->vc_rows;
+	}
+	if (new_y < min_y)
+		vc->state.y = min_y;
+	else if (new_y >= max_y)
+		vc->state.y = max_y - 1;
+	else
+		vc->state.y = new_y;
+	vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
+		(vc->state.x << 1);
+	vc->vc_need_wrap = 0;
+}
+
+/* for absolute user moves, when decom is set */
+static void gotoxay(struct vc_data *vc, int new_x, int new_y)
+{
+	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
+}
+
+void scrollback(struct vc_data *vc)
+{
+	scrolldelta(-(vc->vc_rows / 2));
+}
+
+void scrollfront(struct vc_data *vc, int lines)
+{
+	if (!lines)
+		lines = vc->vc_rows / 2;
+	scrolldelta(lines);
+}
+
+static void lf(struct vc_data *vc)
+{
+    	/* don't scroll if above bottom of scrolling region, or
+	 * if below scrolling region
+	 */
+	if (vc->state.y + 1 == vc->vc_bottom)
+		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
+	else if (vc->state.y < vc->vc_rows - 1) {
+		vc->state.y++;
+		vc->vc_pos += vc->vc_size_row;
+	}
+	vc->vc_need_wrap = 0;
+	notify_write(vc, '\n');
+}
+
+static void ri(struct vc_data *vc)
+{
+    	/* don't scroll if below top of scrolling region, or
+	 * if above scrolling region
+	 */
+	if (vc->state.y == vc->vc_top)
+		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
+	else if (vc->state.y > 0) {
+		vc->state.y--;
+		vc->vc_pos -= vc->vc_size_row;
+	}
+	vc->vc_need_wrap = 0;
+}
+
+static inline void cr(struct vc_data *vc)
+{
+	vc->vc_pos -= vc->state.x << 1;
+	vc->vc_need_wrap = vc->state.x = 0;
+	notify_write(vc, '\r');
+}
+
+static inline void bs(struct vc_data *vc)
+{
+	if (vc->state.x) {
+		vc->vc_pos -= 2;
+		vc->state.x--;
+		vc->vc_need_wrap = 0;
+		notify_write(vc, '\b');
+	}
+}
+
+static inline void del(struct vc_data *vc)
+{
+	/* ignored */
+}
+
+static void csi_J(struct vc_data *vc, int vpar)
+{
+	unsigned int count;
+	unsigned short * start;
+
+	switch (vpar) {
+		case 0:	/* erase from cursor to end of display */
+			vc_uniscr_clear_line(vc, vc->state.x,
+					     vc->vc_cols - vc->state.x);
+			vc_uniscr_clear_lines(vc, vc->state.y + 1,
+					      vc->vc_rows - vc->state.y - 1);
+			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
+			start = (unsigned short *)vc->vc_pos;
+			break;
+		case 1:	/* erase from start to cursor */
+			vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
+			vc_uniscr_clear_lines(vc, 0, vc->state.y);
+			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
+			start = (unsigned short *)vc->vc_origin;
+			break;
+		case 3: /* include scrollback */
+			flush_scrollback(vc);
+			fallthrough;
+		case 2: /* erase whole display */
+			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
+			count = vc->vc_cols * vc->vc_rows;
+			start = (unsigned short *)vc->vc_origin;
+			break;
+		default:
+			return;
+	}
+	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) start, count);
+	vc->vc_need_wrap = 0;
+}
+
+static void csi_K(struct vc_data *vc, int vpar)
+{
+	unsigned int count;
+	unsigned short *start = (unsigned short *)vc->vc_pos;
+	int offset;
+
+	switch (vpar) {
+		case 0:	/* erase from cursor to end of line */
+			offset = 0;
+			count = vc->vc_cols - vc->state.x;
+			break;
+		case 1:	/* erase from start of line to cursor */
+			offset = -vc->state.x;
+			count = vc->state.x + 1;
+			break;
+		case 2: /* erase whole line */
+			offset = -vc->state.x;
+			count = vc->vc_cols;
+			break;
+		default:
+			return;
+	}
+	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
+	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
+	vc->vc_need_wrap = 0;
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long)(start + offset), count);
+}
+
+/* erase the following vpar positions */
+static void csi_X(struct vc_data *vc, unsigned int vpar)
+{					  /* not vt100? */
+	unsigned int count;
+
+	if (!vpar)
+		vpar++;
+
+	count = min(vpar, vc->vc_cols - vc->state.x);
+
+	vc_uniscr_clear_line(vc, vc->state.x, count);
+	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
+	if (con_should_update(vc))
+		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
+	vc->vc_need_wrap = 0;
+}
+
+static void default_attr(struct vc_data *vc)
+{
+	vc->state.intensity = VCI_NORMAL;
+	vc->state.italic = false;
+	vc->state.underline = false;
+	vc->state.reverse = false;
+	vc->state.blink = false;
+	vc->state.color = vc->vc_def_color;
+}
+
+struct rgb { u8 r; u8 g; u8 b; };
+
+static void rgb_from_256(int i, struct rgb *c)
+{
+	if (i < 8) {            /* Standard colours. */
+		c->r = i&1 ? 0xaa : 0x00;
+		c->g = i&2 ? 0xaa : 0x00;
+		c->b = i&4 ? 0xaa : 0x00;
+	} else if (i < 16) {
+		c->r = i&1 ? 0xff : 0x55;
+		c->g = i&2 ? 0xff : 0x55;
+		c->b = i&4 ? 0xff : 0x55;
+	} else if (i < 232) {   /* 6x6x6 colour cube. */
+		c->r = (i - 16) / 36 * 85 / 2;
+		c->g = (i - 16) / 6 % 6 * 85 / 2;
+		c->b = (i - 16) % 6 * 85 / 2;
+	} else                  /* Grayscale ramp. */
+		c->r = c->g = c->b = i * 10 - 2312;
+}
+
+static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
+{
+	u8 hue = 0, max = max3(c->r, c->g, c->b);
+
+	if (c->r > max / 2)
+		hue |= 4;
+	if (c->g > max / 2)
+		hue |= 2;
+	if (c->b > max / 2)
+		hue |= 1;
+
+	if (hue == 7 && max <= 0x55) {
+		hue = 0;
+		vc->state.intensity = VCI_BOLD;
+	} else if (max > 0xaa)
+		vc->state.intensity = VCI_BOLD;
+	else
+		vc->state.intensity = VCI_NORMAL;
+
+	vc->state.color = (vc->state.color & 0xf0) | hue;
+}
+
+static void rgb_background(struct vc_data *vc, const struct rgb *c)
+{
+	/* For backgrounds, err on the dark side. */
+	vc->state.color = (vc->state.color & 0x0f)
+		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
+}
+
+/*
+ * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
+ * and thus need to be detected and ignored by hand. That standard also
+ * wants : rather than ; as separators but sequences containing : are currently
+ * completely ignored by the parser.
+ *
+ * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
+ * supporting them.
+ */
+static int vc_t416_color(struct vc_data *vc, int i,
+		void(*set_color)(struct vc_data *vc, const struct rgb *c))
+{
+	struct rgb c;
+
+	i++;
+	if (i > vc->vc_npar)
+		return i;
+
+	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
+		/* 256 colours */
+		i++;
+		rgb_from_256(vc->vc_par[i], &c);
+	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
+		/* 24 bit */
+		c.r = vc->vc_par[i + 1];
+		c.g = vc->vc_par[i + 2];
+		c.b = vc->vc_par[i + 3];
+		i += 3;
+	} else
+		return i;
+
+	set_color(vc, &c);
+
+	return i;
+}
+
+/* console_lock is held */
+static void csi_m(struct vc_data *vc)
+{
+	int i;
+
+	for (i = 0; i <= vc->vc_npar; i++)
+		switch (vc->vc_par[i]) {
+		case 0:	/* all attributes off */
+			default_attr(vc);
+			break;
+		case 1:
+			vc->state.intensity = VCI_BOLD;
+			break;
+		case 2:
+			vc->state.intensity = VCI_HALF_BRIGHT;
+			break;
+		case 3:
+			vc->state.italic = true;
+			break;
+		case 21:
+			/*
+			 * No console drivers support double underline, so
+			 * convert it to a single underline.
+			 */
+		case 4:
+			vc->state.underline = true;
+			break;
+		case 5:
+			vc->state.blink = true;
+			break;
+		case 7:
+			vc->state.reverse = true;
+			break;
+		case 10: /* ANSI X3.64-1979 (SCO-ish?)
+			  * Select primary font, don't display control chars if
+			  * defined, don't set bit 8 on output.
+			  */
+			vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
+			vc->vc_disp_ctrl = 0;
+			vc->vc_toggle_meta = 0;
+			break;
+		case 11: /* ANSI X3.64-1979 (SCO-ish?)
+			  * Select first alternate font, lets chars < 32 be
+			  * displayed as ROM chars.
+			  */
+			vc->vc_translate = set_translate(IBMPC_MAP, vc);
+			vc->vc_disp_ctrl = 1;
+			vc->vc_toggle_meta = 0;
+			break;
+		case 12: /* ANSI X3.64-1979 (SCO-ish?)
+			  * Select second alternate font, toggle high bit
+			  * before displaying as ROM char.
+			  */
+			vc->vc_translate = set_translate(IBMPC_MAP, vc);
+			vc->vc_disp_ctrl = 1;
+			vc->vc_toggle_meta = 1;
+			break;
+		case 22:
+			vc->state.intensity = VCI_NORMAL;
+			break;
+		case 23:
+			vc->state.italic = false;
+			break;
+		case 24:
+			vc->state.underline = false;
+			break;
+		case 25:
+			vc->state.blink = false;
+			break;
+		case 27:
+			vc->state.reverse = false;
+			break;
+		case 38:
+			i = vc_t416_color(vc, i, rgb_foreground);
+			break;
+		case 48:
+			i = vc_t416_color(vc, i, rgb_background);
+			break;
+		case 39:
+			vc->state.color = (vc->vc_def_color & 0x0f) |
+				(vc->state.color & 0xf0);
+			break;
+		case 49:
+			vc->state.color = (vc->vc_def_color & 0xf0) |
+				(vc->state.color & 0x0f);
+			break;
+		default:
+			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
+				if (vc->vc_par[i] < 100)
+					vc->state.intensity = VCI_BOLD;
+				vc->vc_par[i] -= 60;
+			}
+			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
+				vc->state.color = color_table[vc->vc_par[i] - 30]
+					| (vc->state.color & 0xf0);
+			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
+				vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
+					| (vc->state.color & 0x0f);
+			break;
+		}
+	update_attr(vc);
+}
+
+static void respond_string(const char *p, size_t len, struct tty_port *port)
+{
+	tty_insert_flip_string(port, p, len);
+	tty_flip_buffer_push(port);
+}
+
+static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
+{
+	char buf[40];
+	int len;
+
+	len = sprintf(buf, "\033[%d;%dR", vc->state.y +
+			(vc->vc_decom ? vc->vc_top + 1 : 1),
+			vc->state.x + 1);
+	respond_string(buf, len, tty->port);
+}
+
+static inline void status_report(struct tty_struct *tty)
+{
+	static const char teminal_ok[] = "\033[0n";
+
+	respond_string(teminal_ok, strlen(teminal_ok), tty->port);
+}
+
+static inline void respond_ID(struct tty_struct *tty)
+{
+	/* terminal answer to an ESC-Z or csi0c query. */
+	static const char vt102_id[] = "\033[?6c";
+
+	respond_string(vt102_id, strlen(vt102_id), tty->port);
+}
+
+void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
+{
+	char buf[8];
+	int len;
+
+	len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
+			(char)('!' + mrx), (char)('!' + mry));
+	respond_string(buf, len, tty->port);
+}
+
+/* invoked via ioctl(TIOCLINUX) and through set_selection_user */
+int mouse_reporting(void)
+{
+	return vc_cons[fg_console].d->vc_report_mouse;
+}
+
+/* console_lock is held */
+static void set_mode(struct vc_data *vc, int on_off)
+{
+	int i;
+
+	for (i = 0; i <= vc->vc_npar; i++)
+		if (vc->vc_priv == EPdec) {
+			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
+			case 1:			/* Cursor keys send ^[Ox/^[[x */
+				if (on_off)
+					set_kbd(vc, decckm);
+				else
+					clr_kbd(vc, decckm);
+				break;
+			case 3:	/* 80/132 mode switch unimplemented */
+#if 0
+				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
+				/* this alone does not suffice; some user mode
+				   utility has to change the hardware regs */
+#endif
+				break;
+			case 5:			/* Inverted screen on/off */
+				if (vc->vc_decscnm != on_off) {
+					vc->vc_decscnm = on_off;
+					invert_screen(vc, 0,
+							vc->vc_screenbuf_size,
+							false);
+					update_attr(vc);
+				}
+				break;
+			case 6:			/* Origin relative/absolute */
+				vc->vc_decom = on_off;
+				gotoxay(vc, 0, 0);
+				break;
+			case 7:			/* Autowrap on/off */
+				vc->vc_decawm = on_off;
+				break;
+			case 8:			/* Autorepeat on/off */
+				if (on_off)
+					set_kbd(vc, decarm);
+				else
+					clr_kbd(vc, decarm);
+				break;
+			case 9:
+				vc->vc_report_mouse = on_off ? 1 : 0;
+				break;
+			case 25:		/* Cursor on/off */
+				vc->vc_deccm = on_off;
+				break;
+			case 1000:
+				vc->vc_report_mouse = on_off ? 2 : 0;
+				break;
+			}
+		} else {
+			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
+			case 3:			/* Monitor (display ctrls) */
+				vc->vc_disp_ctrl = on_off;
+				break;
+			case 4:			/* Insert Mode on/off */
+				vc->vc_decim = on_off;
+				break;
+			case 20:		/* Lf, Enter == CrLf/Lf */
+				if (on_off)
+					set_kbd(vc, lnm);
+				else
+					clr_kbd(vc, lnm);
+				break;
+			}
+		}
+}
+
+/* console_lock is held */
+static void setterm_command(struct vc_data *vc)
+{
+	switch (vc->vc_par[0]) {
+	case 1:	/* set color for underline mode */
+		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
+			vc->vc_ulcolor = color_table[vc->vc_par[1]];
+			if (vc->state.underline)
+				update_attr(vc);
+		}
+		break;
+	case 2:	/* set color for half intensity mode */
+		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
+			vc->vc_halfcolor = color_table[vc->vc_par[1]];
+			if (vc->state.intensity == VCI_HALF_BRIGHT)
+				update_attr(vc);
+		}
+		break;
+	case 8:	/* store colors as defaults */
+		vc->vc_def_color = vc->vc_attr;
+		if (vc->vc_hi_font_mask == 0x100)
+			vc->vc_def_color >>= 1;
+		default_attr(vc);
+		update_attr(vc);
+		break;
+	case 9:	/* set blanking interval */
+		blankinterval = min(vc->vc_par[1], 60U) * 60;
+		poke_blanked_console();
+		break;
+	case 10: /* set bell frequency in Hz */
+		if (vc->vc_npar >= 1)
+			vc->vc_bell_pitch = vc->vc_par[1];
+		else
+			vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
+		break;
+	case 11: /* set bell duration in msec */
+		if (vc->vc_npar >= 1)
+			vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
+				msecs_to_jiffies(vc->vc_par[1]) : 0;
+		else
+			vc->vc_bell_duration = DEFAULT_BELL_DURATION;
+		break;
+	case 12: /* bring specified console to the front */
+		if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
+			set_console(vc->vc_par[1] - 1);
+		break;
+	case 13: /* unblank the screen */
+		poke_blanked_console();
+		break;
+	case 14: /* set vesa powerdown interval */
+		vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
+		break;
+	case 15: /* activate the previous console */
+		set_console(last_console);
+		break;
+	case 16: /* set cursor blink duration in msec */
+		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
+				vc->vc_par[1] <= USHRT_MAX)
+			vc->vc_cur_blink_ms = vc->vc_par[1];
+		else
+			vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+		break;
+	}
+}
+
+/* console_lock is held */
+static void csi_at(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_cols - vc->state.x)
+		nr = vc->vc_cols - vc->state.x;
+	else if (!nr)
+		nr = 1;
+	insert_char(vc, nr);
+}
+
+/* console_lock is held */
+static void csi_L(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_rows - vc->state.y)
+		nr = vc->vc_rows - vc->state.y;
+	else if (!nr)
+		nr = 1;
+	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
+	vc->vc_need_wrap = 0;
+}
+
+/* console_lock is held */
+static void csi_P(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_cols - vc->state.x)
+		nr = vc->vc_cols - vc->state.x;
+	else if (!nr)
+		nr = 1;
+	delete_char(vc, nr);
+}
+
+/* console_lock is held */
+static void csi_M(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_rows - vc->state.y)
+		nr = vc->vc_rows - vc->state.y;
+	else if (!nr)
+		nr=1;
+	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
+	vc->vc_need_wrap = 0;
+}
+
+/* console_lock is held (except via vc_init->reset_terminal */
+static void save_cur(struct vc_data *vc)
+{
+	memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
+}
+
+/* console_lock is held */
+static void restore_cur(struct vc_data *vc)
+{
+	memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
+
+	gotoxy(vc, vc->state.x, vc->state.y);
+	vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
+			vc);
+	update_attr(vc);
+	vc->vc_need_wrap = 0;
+}
+
+enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
+	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
+	ESpalette, ESosc, ESapc, ESpm, ESdcs };
+
+/* console_lock is held (except via vc_init()) */
+static void reset_terminal(struct vc_data *vc, int do_clear)
+{
+	unsigned int i;
+
+	vc->vc_top		= 0;
+	vc->vc_bottom		= vc->vc_rows;
+	vc->vc_state		= ESnormal;
+	vc->vc_priv		= EPecma;
+	vc->vc_translate	= set_translate(LAT1_MAP, vc);
+	vc->state.Gx_charset[0]	= LAT1_MAP;
+	vc->state.Gx_charset[1]	= GRAF_MAP;
+	vc->state.charset	= 0;
+	vc->vc_need_wrap	= 0;
+	vc->vc_report_mouse	= 0;
+	vc->vc_utf              = default_utf8;
+	vc->vc_utf_count	= 0;
+
+	vc->vc_disp_ctrl	= 0;
+	vc->vc_toggle_meta	= 0;
+
+	vc->vc_decscnm		= 0;
+	vc->vc_decom		= 0;
+	vc->vc_decawm		= 1;
+	vc->vc_deccm		= global_cursor_default;
+	vc->vc_decim		= 0;
+
+	vt_reset_keyboard(vc->vc_num);
+
+	vc->vc_cursor_type = cur_default;
+	vc->vc_complement_mask = vc->vc_s_complement_mask;
+
+	default_attr(vc);
+	update_attr(vc);
+
+	bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
+	for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
+		set_bit(i, vc->vc_tab_stop);
+
+	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
+	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
+	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+
+	gotoxy(vc, 0, 0);
+	save_cur(vc);
+	if (do_clear)
+	    csi_J(vc, 2);
+}
+
+static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
+{
+	unsigned char *charset = &vc->state.Gx_charset[which];
+
+	switch (c) {
+	case '0':
+		*charset = GRAF_MAP;
+		break;
+	case 'B':
+		*charset = LAT1_MAP;
+		break;
+	case 'U':
+		*charset = IBMPC_MAP;
+		break;
+	case 'K':
+		*charset = USER_MAP;
+		break;
+	}
+
+	if (vc->state.charset == which)
+		vc->vc_translate = set_translate(*charset, vc);
+}
+
+/* is this state an ANSI control string? */
+static bool ansi_control_string(unsigned int state)
+{
+	if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
+		return true;
+	return false;
+}
+
+/* console_lock is held */
+static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
+{
+	/*
+	 *  Control characters can be used in the _middle_
+	 *  of an escape sequence, aside from ANSI control strings.
+	 */
+	if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
+		return;
+	switch (c) {
+	case 0:
+		return;
+	case 7:
+		if (ansi_control_string(vc->vc_state))
+			vc->vc_state = ESnormal;
+		else if (vc->vc_bell_duration)
+			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
+		return;
+	case 8:
+		bs(vc);
+		return;
+	case 9:
+		vc->vc_pos -= (vc->state.x << 1);
+
+		vc->state.x = find_next_bit(vc->vc_tab_stop,
+				min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
+				vc->state.x + 1);
+		if (vc->state.x >= VC_TABSTOPS_COUNT)
+			vc->state.x = vc->vc_cols - 1;
+
+		vc->vc_pos += (vc->state.x << 1);
+		notify_write(vc, '\t');
+		return;
+	case 10: case 11: case 12:
+		lf(vc);
+		if (!is_kbd(vc, lnm))
+			return;
+		fallthrough;
+	case 13:
+		cr(vc);
+		return;
+	case 14:
+		vc->state.charset = 1;
+		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
+		vc->vc_disp_ctrl = 1;
+		return;
+	case 15:
+		vc->state.charset = 0;
+		vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
+		vc->vc_disp_ctrl = 0;
+		return;
+	case 24: case 26:
+		vc->vc_state = ESnormal;
+		return;
+	case 27:
+		vc->vc_state = ESesc;
+		return;
+	case 127:
+		del(vc);
+		return;
+	case 128+27:
+		vc->vc_state = ESsquare;
+		return;
+	}
+	switch(vc->vc_state) {
+	case ESesc:
+		vc->vc_state = ESnormal;
+		switch (c) {
+		case '[':
+			vc->vc_state = ESsquare;
+			return;
+		case ']':
+			vc->vc_state = ESnonstd;
+			return;
+		case '_':
+			vc->vc_state = ESapc;
+			return;
+		case '^':
+			vc->vc_state = ESpm;
+			return;
+		case '%':
+			vc->vc_state = ESpercent;
+			return;
+		case 'E':
+			cr(vc);
+			lf(vc);
+			return;
+		case 'M':
+			ri(vc);
+			return;
+		case 'D':
+			lf(vc);
+			return;
+		case 'H':
+			if (vc->state.x < VC_TABSTOPS_COUNT)
+				set_bit(vc->state.x, vc->vc_tab_stop);
+			return;
+		case 'P':
+			vc->vc_state = ESdcs;
+			return;
+		case 'Z':
+			respond_ID(tty);
+			return;
+		case '7':
+			save_cur(vc);
+			return;
+		case '8':
+			restore_cur(vc);
+			return;
+		case '(':
+			vc->vc_state = ESsetG0;
+			return;
+		case ')':
+			vc->vc_state = ESsetG1;
+			return;
+		case '#':
+			vc->vc_state = EShash;
+			return;
+		case 'c':
+			reset_terminal(vc, 1);
+			return;
+		case '>':  /* Numeric keypad */
+			clr_kbd(vc, kbdapplic);
+			return;
+		case '=':  /* Appl. keypad */
+			set_kbd(vc, kbdapplic);
+			return;
+		}
+		return;
+	case ESnonstd:
+		if (c=='P') {   /* palette escape sequence */
+			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
+				vc->vc_par[vc->vc_npar] = 0;
+			vc->vc_npar = 0;
+			vc->vc_state = ESpalette;
+			return;
+		} else if (c=='R') {   /* reset palette */
+			reset_palette(vc);
+			vc->vc_state = ESnormal;
+		} else if (c>='0' && c<='9')
+			vc->vc_state = ESosc;
+		else
+			vc->vc_state = ESnormal;
+		return;
+	case ESpalette:
+		if (isxdigit(c)) {
+			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
+			if (vc->vc_npar == 7) {
+				int i = vc->vc_par[0] * 3, j = 1;
+				vc->vc_palette[i] = 16 * vc->vc_par[j++];
+				vc->vc_palette[i++] += vc->vc_par[j++];
+				vc->vc_palette[i] = 16 * vc->vc_par[j++];
+				vc->vc_palette[i++] += vc->vc_par[j++];
+				vc->vc_palette[i] = 16 * vc->vc_par[j++];
+				vc->vc_palette[i] += vc->vc_par[j];
+				set_palette(vc);
+				vc->vc_state = ESnormal;
+			}
+		} else
+			vc->vc_state = ESnormal;
+		return;
+	case ESsquare:
+		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
+			vc->vc_par[vc->vc_npar] = 0;
+		vc->vc_npar = 0;
+		vc->vc_state = ESgetpars;
+		if (c == '[') { /* Function key */
+			vc->vc_state=ESfunckey;
+			return;
+		}
+		switch (c) {
+		case '?':
+			vc->vc_priv = EPdec;
+			return;
+		case '>':
+			vc->vc_priv = EPgt;
+			return;
+		case '=':
+			vc->vc_priv = EPeq;
+			return;
+		case '<':
+			vc->vc_priv = EPlt;
+			return;
+		}
+		vc->vc_priv = EPecma;
+		fallthrough;
+	case ESgetpars:
+		if (c == ';' && vc->vc_npar < NPAR - 1) {
+			vc->vc_npar++;
+			return;
+		} else if (c>='0' && c<='9') {
+			vc->vc_par[vc->vc_npar] *= 10;
+			vc->vc_par[vc->vc_npar] += c - '0';
+			return;
+		}
+		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
+			vc->vc_state = EScsiignore;
+			return;
+		}
+		vc->vc_state = ESnormal;
+		switch(c) {
+		case 'h':
+			if (vc->vc_priv <= EPdec)
+				set_mode(vc, 1);
+			return;
+		case 'l':
+			if (vc->vc_priv <= EPdec)
+				set_mode(vc, 0);
+			return;
+		case 'c':
+			if (vc->vc_priv == EPdec) {
+				if (vc->vc_par[0])
+					vc->vc_cursor_type =
+						CUR_MAKE(vc->vc_par[0],
+							 vc->vc_par[1],
+							 vc->vc_par[2]);
+				else
+					vc->vc_cursor_type = cur_default;
+				return;
+			}
+			break;
+		case 'm':
+			if (vc->vc_priv == EPdec) {
+				clear_selection();
+				if (vc->vc_par[0])
+					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
+				else
+					vc->vc_complement_mask = vc->vc_s_complement_mask;
+				return;
+			}
+			break;
+		case 'n':
+			if (vc->vc_priv == EPecma) {
+				if (vc->vc_par[0] == 5)
+					status_report(tty);
+				else if (vc->vc_par[0] == 6)
+					cursor_report(vc, tty);
+			}
+			return;
+		}
+		if (vc->vc_priv != EPecma) {
+			vc->vc_priv = EPecma;
+			return;
+		}
+		switch(c) {
+		case 'G': case '`':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			gotoxy(vc, vc->vc_par[0], vc->state.y);
+			return;
+		case 'A':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
+			return;
+		case 'B': case 'e':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
+			return;
+		case 'C': case 'a':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
+			return;
+		case 'D':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
+			return;
+		case 'E':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
+			return;
+		case 'F':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
+			return;
+		case 'd':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			gotoxay(vc, vc->state.x ,vc->vc_par[0]);
+			return;
+		case 'H': case 'f':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			if (vc->vc_par[1])
+				vc->vc_par[1]--;
+			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
+			return;
+		case 'J':
+			csi_J(vc, vc->vc_par[0]);
+			return;
+		case 'K':
+			csi_K(vc, vc->vc_par[0]);
+			return;
+		case 'L':
+			csi_L(vc, vc->vc_par[0]);
+			return;
+		case 'M':
+			csi_M(vc, vc->vc_par[0]);
+			return;
+		case 'P':
+			csi_P(vc, vc->vc_par[0]);
+			return;
+		case 'c':
+			if (!vc->vc_par[0])
+				respond_ID(tty);
+			return;
+		case 'g':
+			if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
+				set_bit(vc->state.x, vc->vc_tab_stop);
+			else if (vc->vc_par[0] == 3)
+				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
+			return;
+		case 'm':
+			csi_m(vc);
+			return;
+		case 'q': /* DECLL - but only 3 leds */
+			/* map 0,1,2,3 to 0,1,2,4 */
+			if (vc->vc_par[0] < 4)
+				vt_set_led_state(vc->vc_num,
+					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
+			return;
+		case 'r':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			if (!vc->vc_par[1])
+				vc->vc_par[1] = vc->vc_rows;
+			/* Minimum allowed region is 2 lines */
+			if (vc->vc_par[0] < vc->vc_par[1] &&
+			    vc->vc_par[1] <= vc->vc_rows) {
+				vc->vc_top = vc->vc_par[0] - 1;
+				vc->vc_bottom = vc->vc_par[1];
+				gotoxay(vc, 0, 0);
+			}
+			return;
+		case 's':
+			save_cur(vc);
+			return;
+		case 'u':
+			restore_cur(vc);
+			return;
+		case 'X':
+			csi_X(vc, vc->vc_par[0]);
+			return;
+		case '@':
+			csi_at(vc, vc->vc_par[0]);
+			return;
+		case ']': /* setterm functions */
+			setterm_command(vc);
+			return;
+		}
+		return;
+	case EScsiignore:
+		if (c >= 20 && c <= 0x3f)
+			return;
+		vc->vc_state = ESnormal;
+		return;
+	case ESpercent:
+		vc->vc_state = ESnormal;
+		switch (c) {
+		case '@':  /* defined in ISO 2022 */
+			vc->vc_utf = 0;
+			return;
+		case 'G':  /* prelim official escape code */
+		case '8':  /* retained for compatibility */
+			vc->vc_utf = 1;
+			return;
+		}
+		return;
+	case ESfunckey:
+		vc->vc_state = ESnormal;
+		return;
+	case EShash:
+		vc->vc_state = ESnormal;
+		if (c == '8') {
+			/* DEC screen alignment test. kludge :-) */
+			vc->vc_video_erase_char =
+				(vc->vc_video_erase_char & 0xff00) | 'E';
+			csi_J(vc, 2);
+			vc->vc_video_erase_char =
+				(vc->vc_video_erase_char & 0xff00) | ' ';
+			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
+		}
+		return;
+	case ESsetG0:
+		vc_setGx(vc, 0, c);
+		vc->vc_state = ESnormal;
+		return;
+	case ESsetG1:
+		vc_setGx(vc, 1, c);
+		vc->vc_state = ESnormal;
+		return;
+	case ESapc:
+		return;
+	case ESosc:
+		return;
+	case ESpm:
+		return;
+	case ESdcs:
+		return;
+	default:
+		vc->vc_state = ESnormal;
+	}
+}
+
+/* is_double_width() is based on the wcwidth() implementation by
+ * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
+ * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+struct interval {
+	uint32_t first;
+	uint32_t last;
+};
+
+static int ucs_cmp(const void *key, const void *elt)
+{
+	uint32_t ucs = *(uint32_t *)key;
+	struct interval e = *(struct interval *) elt;
+
+	if (ucs > e.last)
+		return 1;
+	else if (ucs < e.first)
+		return -1;
+	return 0;
+}
+
+static int is_double_width(uint32_t ucs)
+{
+	static const struct interval double_width[] = {
+		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
+		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
+		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
+		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
+	};
+	if (ucs < double_width[0].first ||
+	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
+		return 0;
+
+	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
+			sizeof(struct interval), ucs_cmp) != NULL;
+}
+
+struct vc_draw_region {
+	unsigned long from, to;
+	int x;
+};
+
+static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
+{
+	if (draw->x < 0)
+		return;
+
+	vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
+			(u16 *)draw->to - (u16 *)draw->from, vc->state.y,
+			draw->x);
+	draw->x = -1;
+}
+
+static inline int vc_translate_ascii(const struct vc_data *vc, int c)
+{
+	if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
+		if (vc->vc_toggle_meta)
+			c |= 0x80;
+
+		return vc->vc_translate[c];
+	}
+
+	return c;
+}
+
+
+/**
+ * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
+ * @c: the received character, or U+FFFD for invalid sequences.
+ */
+static inline int vc_sanitize_unicode(const int c)
+{
+	if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
+		return 0xfffd;
+
+	return c;
+}
+
+/**
+ * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
+ * @vc: virtual console
+ * @c: character to translate
+ * @rescan: we return true if we need more (continuation) data
+ *
+ * @vc_utf_char is the being-constructed unicode character.
+ * @vc_utf_count is the number of continuation bytes still expected to arrive.
+ * @vc_npar is the number of continuation bytes arrived so far.
+ */
+static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
+{
+	static const u32 utf8_length_changes[] = {
+		0x0000007f, 0x000007ff, 0x0000ffff,
+		0x001fffff, 0x03ffffff, 0x7fffffff
+	};
+
+	/* Continuation byte received */
+	if ((c & 0xc0) == 0x80) {
+		/* Unexpected continuation byte? */
+		if (!vc->vc_utf_count)
+			return 0xfffd;
+
+		vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
+		vc->vc_npar++;
+		if (--vc->vc_utf_count)
+			goto need_more_bytes;
+
+		/* Got a whole character */
+		c = vc->vc_utf_char;
+		/* Reject overlong sequences */
+		if (c <= utf8_length_changes[vc->vc_npar - 1] ||
+				c > utf8_length_changes[vc->vc_npar])
+			return 0xfffd;
+
+		return vc_sanitize_unicode(c);
+	}
+
+	/* Single ASCII byte or first byte of a sequence received */
+	if (vc->vc_utf_count) {
+		/* Continuation byte expected */
+		*rescan = true;
+		vc->vc_utf_count = 0;
+		return 0xfffd;
+	}
+
+	/* Nothing to do if an ASCII byte was received */
+	if (c <= 0x7f)
+		return c;
+
+	/* First byte of a multibyte sequence received */
+	vc->vc_npar = 0;
+	if ((c & 0xe0) == 0xc0) {
+		vc->vc_utf_count = 1;
+		vc->vc_utf_char = (c & 0x1f);
+	} else if ((c & 0xf0) == 0xe0) {
+		vc->vc_utf_count = 2;
+		vc->vc_utf_char = (c & 0x0f);
+	} else if ((c & 0xf8) == 0xf0) {
+		vc->vc_utf_count = 3;
+		vc->vc_utf_char = (c & 0x07);
+	} else if ((c & 0xfc) == 0xf8) {
+		vc->vc_utf_count = 4;
+		vc->vc_utf_char = (c & 0x03);
+	} else if ((c & 0xfe) == 0xfc) {
+		vc->vc_utf_count = 5;
+		vc->vc_utf_char = (c & 0x01);
+	} else {
+		/* 254 and 255 are invalid */
+		return 0xfffd;
+	}
+
+need_more_bytes:
+	return -1;
+}
+
+static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
+{
+	/* Do no translation at all in control states */
+	if (vc->vc_state != ESnormal)
+		return *c;
+
+	if (vc->vc_utf && !vc->vc_disp_ctrl)
+		return *c = vc_translate_unicode(vc, *c, rescan);
+
+	/* no utf or alternate charset mode */
+	return vc_translate_ascii(vc, *c);
+}
+
+static inline unsigned char vc_invert_attr(const struct vc_data *vc)
+{
+	if (!vc->vc_can_do_color)
+		return vc->vc_attr ^ 0x08;
+
+	if (vc->vc_hi_font_mask == 0x100)
+		return   (vc->vc_attr & 0x11) |
+			((vc->vc_attr & 0xe0) >> 4) |
+			((vc->vc_attr & 0x0e) << 4);
+
+	return   (vc->vc_attr & 0x88) |
+		((vc->vc_attr & 0x70) >> 4) |
+		((vc->vc_attr & 0x07) << 4);
+}
+
+static bool vc_is_control(struct vc_data *vc, int tc, int c)
+{
+	/*
+	 * A bitmap for codes <32. A bit of 1 indicates that the code
+	 * corresponding to that bit number invokes some special action (such
+	 * as cursor movement) and should not be displayed as a glyph unless
+	 * the disp_ctrl mode is explicitly enabled.
+	 */
+	static const u32 CTRL_ACTION = 0x0d00ff81;
+	/* Cannot be overridden by disp_ctrl */
+	static const u32 CTRL_ALWAYS = 0x0800f501;
+
+	if (vc->vc_state != ESnormal)
+		return true;
+
+	if (!tc)
+		return true;
+
+	/*
+	 * If the original code was a control character we only allow a glyph
+	 * to be displayed if the code is not normally used (such as for cursor
+	 * movement) or if the disp_ctrl mode has been explicitly enabled.
+	 * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
+	 * displayed as control characters, as the console would be pretty
+	 * useless without them; to display an arbitrary font position use the
+	 * direct-to-font zone in UTF-8 mode.
+	 */
+	if (c < 32) {
+		if (vc->vc_disp_ctrl)
+			return CTRL_ALWAYS & BIT(c);
+		else
+			return vc->vc_utf || (CTRL_ACTION & BIT(c));
+	}
+
+	if (c == 127 && !vc->vc_disp_ctrl)
+		return true;
+
+	if (c == 128 + 27)
+		return true;
+
+	return false;
+}
+
+static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
+		struct vc_draw_region *draw)
+{
+	int next_c;
+	unsigned char vc_attr = vc->vc_attr;
+	u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
+	u8 width = 1;
+	bool inverse = false;
+
+	if (vc->vc_utf && !vc->vc_disp_ctrl) {
+		if (is_double_width(c))
+			width = 2;
+	}
+
+	/* Now try to find out how to display it */
+	tc = conv_uni_to_pc(vc, tc);
+	if (tc & ~charmask) {
+		if (tc == -1 || tc == -2)
+			return -1; /* nothing to display */
+
+		/* Glyph not found */
+		if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
+				!(c & ~charmask)) {
+			/*
+			 * In legacy mode use the glyph we get by a 1:1
+			 * mapping.
+			 * This would make absolutely no sense with Unicode in
+			 * mind, but do this for ASCII characters since a font
+			 * may lack Unicode mapping info and we don't want to
+			 * end up with having question marks only.
+			 */
+			tc = c;
+		} else {
+			/*
+			 * Display U+FFFD. If it's not found, display an inverse
+			 * question mark.
+			 */
+			tc = conv_uni_to_pc(vc, 0xfffd);
+			if (tc < 0) {
+				inverse = true;
+				tc = conv_uni_to_pc(vc, '?');
+				if (tc < 0)
+					tc = '?';
+
+				vc_attr = vc_invert_attr(vc);
+				con_flush(vc, draw);
+			}
+		}
+	}
+
+	next_c = c;
+	while (1) {
+		if (vc->vc_need_wrap || vc->vc_decim)
+			con_flush(vc, draw);
+		if (vc->vc_need_wrap) {
+			cr(vc);
+			lf(vc);
+		}
+		if (vc->vc_decim)
+			insert_char(vc, 1);
+		vc_uniscr_putc(vc, next_c);
+
+		if (himask)
+			tc = ((tc & 0x100) ? himask : 0) |
+			      (tc &  0xff);
+		tc |= (vc_attr << 8) & ~himask;
+
+		scr_writew(tc, (u16 *)vc->vc_pos);
+
+		if (con_should_update(vc) && draw->x < 0) {
+			draw->x = vc->state.x;
+			draw->from = vc->vc_pos;
+		}
+		if (vc->state.x == vc->vc_cols - 1) {
+			vc->vc_need_wrap = vc->vc_decawm;
+			draw->to = vc->vc_pos + 2;
+		} else {
+			vc->state.x++;
+			draw->to = (vc->vc_pos += 2);
+		}
+
+		if (!--width)
+			break;
+
+		/* A space is printed in the second column */
+		tc = conv_uni_to_pc(vc, ' ');
+		if (tc < 0)
+			tc = ' ';
+		next_c = ' ';
+	}
+	notify_write(vc, c);
+
+	if (inverse)
+		con_flush(vc, draw);
+
+	return 0;
+}
+
+/* acquires console_lock */
+static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
+{
+	struct vc_draw_region draw = {
+		.x = -1,
+	};
+	int c, tc, n = 0;
+	unsigned int currcons;
+	struct vc_data *vc;
+	struct vt_notifier_param param;
+	bool rescan;
+
+	if (in_interrupt())
+		return count;
+
+	console_lock();
+	vc = tty->driver_data;
+	if (vc == NULL) {
+		pr_err("vt: argh, driver_data is NULL !\n");
+		console_unlock();
+		return 0;
+	}
+
+	currcons = vc->vc_num;
+	if (!vc_cons_allocated(currcons)) {
+		/* could this happen? */
+		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
+		console_unlock();
+		return 0;
+	}
+
+
+	/* undraw cursor first */
+	if (con_is_fg(vc))
+		hide_cursor(vc);
+
+	param.vc = vc;
+
+	while (!tty->flow.stopped && count) {
+		int orig = *buf;
+		buf++;
+		n++;
+		count--;
+rescan_last_byte:
+		c = orig;
+		rescan = false;
+
+		tc = vc_translate(vc, &c, &rescan);
+		if (tc == -1)
+			continue;
+
+		param.c = tc;
+		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
+					&param) == NOTIFY_STOP)
+			continue;
+
+		if (vc_is_control(vc, tc, c)) {
+			con_flush(vc, &draw);
+			do_con_trol(tty, vc, orig);
+			continue;
+		}
+
+		if (vc_con_write_normal(vc, tc, c, &draw) < 0)
+			continue;
+
+		if (rescan)
+			goto rescan_last_byte;
+	}
+	con_flush(vc, &draw);
+	console_conditional_schedule();
+	notify_update(vc);
+	console_unlock();
+	return n;
+}
+
+/*
+ * This is the console switching callback.
+ *
+ * Doing console switching in a process context allows
+ * us to do the switches asynchronously (needed when we want
+ * to switch due to a keyboard interrupt).  Synchronization
+ * with other console code and prevention of re-entrancy is
+ * ensured with console_lock.
+ */
+static void console_callback(struct work_struct *ignored)
+{
+	console_lock();
+
+	if (want_console >= 0) {
+		if (want_console != fg_console &&
+		    vc_cons_allocated(want_console)) {
+			hide_cursor(vc_cons[fg_console].d);
+			change_console(vc_cons[want_console].d);
+			/* we only changed when the console had already
+			   been allocated - a new console is not created
+			   in an interrupt routine */
+		}
+		want_console = -1;
+	}
+	if (do_poke_blanked_console) { /* do not unblank for a LED change */
+		do_poke_blanked_console = 0;
+		poke_blanked_console();
+	}
+	if (scrollback_delta) {
+		struct vc_data *vc = vc_cons[fg_console].d;
+		clear_selection();
+		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
+			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
+		scrollback_delta = 0;
+	}
+	if (blank_timer_expired) {
+		do_blank_screen(0);
+		blank_timer_expired = 0;
+	}
+	notify_update(vc_cons[fg_console].d);
+
+	console_unlock();
+}
+
+int set_console(int nr)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+
+	if (!vc_cons_allocated(nr) || vt_dont_switch ||
+		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
+
+		/*
+		 * Console switch will fail in console_callback() or
+		 * change_console() so there is no point scheduling
+		 * the callback
+		 *
+		 * Existing set_console() users don't check the return
+		 * value so this shouldn't break anything
+		 */
+		return -EINVAL;
+	}
+
+	want_console = nr;
+	schedule_console_callback();
+
+	return 0;
+}
+
+struct tty_driver *console_driver;
+
+#ifdef CONFIG_VT_CONSOLE
+
+/**
+ * vt_kmsg_redirect() - Sets/gets the kernel message console
+ * @new:	The new virtual terminal number or -1 if the console should stay
+ * 		unchanged
+ *
+ * By default, the kernel messages are always printed on the current virtual
+ * console. However, the user may modify that default with the
+ * TIOCL_SETKMSGREDIRECT ioctl call.
+ *
+ * This function sets the kernel message console to be @new. It returns the old
+ * virtual console number. The virtual terminal number 0 (both as parameter and
+ * return value) means no redirection (i.e. always printed on the currently
+ * active console).
+ *
+ * The parameter -1 means that only the current console is returned, but the
+ * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
+ * case to make the code more understandable.
+ *
+ * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
+ * the parameter and always returns 0.
+ */
+int vt_kmsg_redirect(int new)
+{
+	static int kmsg_con;
+
+	if (new != -1)
+		return xchg(&kmsg_con, new);
+	else
+		return kmsg_con;
+}
+
+/*
+ *	Console on virtual terminal
+ *
+ * The console must be locked when we get here.
+ */
+
+static void vt_console_print(struct console *co, const char *b, unsigned count)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	unsigned char c;
+	static DEFINE_SPINLOCK(printing_lock);
+	const ushort *start;
+	ushort start_x, cnt;
+	int kmsg_console;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	/* this protects against concurrent oops only */
+	if (!spin_trylock(&printing_lock))
+		return;
+
+	kmsg_console = vt_get_kmsg_redirect();
+	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
+		vc = vc_cons[kmsg_console - 1].d;
+
+	if (!vc_cons_allocated(fg_console)) {
+		/* impossible */
+		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
+		goto quit;
+	}
+
+	if (vc->vc_mode != KD_TEXT)
+		goto quit;
+
+	/* undraw cursor first */
+	if (con_is_fg(vc))
+		hide_cursor(vc);
+
+	start = (ushort *)vc->vc_pos;
+	start_x = vc->state.x;
+	cnt = 0;
+	while (count--) {
+		c = *b++;
+		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
+			if (cnt && con_is_visible(vc))
+				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
+			cnt = 0;
+			if (c == 8) {		/* backspace */
+				bs(vc);
+				start = (ushort *)vc->vc_pos;
+				start_x = vc->state.x;
+				continue;
+			}
+			if (c != 13)
+				lf(vc);
+			cr(vc);
+			start = (ushort *)vc->vc_pos;
+			start_x = vc->state.x;
+			if (c == 10 || c == 13)
+				continue;
+		}
+		vc_uniscr_putc(vc, c);
+		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
+		notify_write(vc, c);
+		cnt++;
+		if (vc->state.x == vc->vc_cols - 1) {
+			vc->vc_need_wrap = 1;
+		} else {
+			vc->vc_pos += 2;
+			vc->state.x++;
+		}
+	}
+	if (cnt && con_is_visible(vc))
+		vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
+	set_cursor(vc);
+	notify_update(vc);
+
+quit:
+	spin_unlock(&printing_lock);
+}
+
+static struct tty_driver *vt_console_device(struct console *c, int *index)
+{
+	*index = c->index ? c->index-1 : fg_console;
+	return console_driver;
+}
+
+static int vt_console_setup(struct console *co, char *options)
+{
+	return co->index >= MAX_NR_CONSOLES ? -EINVAL : 0;
+}
+
+static struct console vt_console_driver = {
+	.name		= "tty",
+	.setup		= vt_console_setup,
+	.write		= vt_console_print,
+	.device		= vt_console_device,
+	.unblank	= unblank_screen,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+#endif
+
+/*
+ *	Handling of Linux-specific VC ioctls
+ */
+
+/*
+ * Generally a bit racy with respect to console_lock();.
+ *
+ * There are some functions which don't need it.
+ *
+ * There are some functions which can sleep for arbitrary periods
+ * (paste_selection) but we don't need the lock there anyway.
+ *
+ * set_selection_user has locking, and definitely needs it
+ */
+
+int tioclinux(struct tty_struct *tty, unsigned long arg)
+{
+	char type, data;
+	char __user *p = (char __user *)arg;
+	int lines;
+	int ret;
+
+	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (get_user(type, p))
+		return -EFAULT;
+	ret = 0;
+
+	switch (type) {
+	case TIOCL_SETSEL:
+		return set_selection_user((struct tiocl_selection
+					 __user *)(p+1), tty);
+	case TIOCL_PASTESEL:
+		return paste_selection(tty);
+	case TIOCL_UNBLANKSCREEN:
+		console_lock();
+		unblank_screen();
+		console_unlock();
+		break;
+	case TIOCL_SELLOADLUT:
+		console_lock();
+		ret = sel_loadlut(p);
+		console_unlock();
+		break;
+	case TIOCL_GETSHIFTSTATE:
+		/*
+		 * Make it possible to react to Shift+Mousebutton. Note that
+		 * 'shift_state' is an undocumented kernel-internal variable;
+		 * programs not closely related to the kernel should not use
+		 * this.
+		 */
+		data = vt_get_shift_state();
+		return put_user(data, p);
+	case TIOCL_GETMOUSEREPORTING:
+		console_lock();	/* May be overkill */
+		data = mouse_reporting();
+		console_unlock();
+		return put_user(data, p);
+	case TIOCL_SETVESABLANK:
+		console_lock();
+		ret = set_vesa_blanking(p);
+		console_unlock();
+		break;
+	case TIOCL_GETKMSGREDIRECT:
+		data = vt_get_kmsg_redirect();
+		return put_user(data, p);
+	case TIOCL_SETKMSGREDIRECT:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (get_user(data, p+1))
+			return -EFAULT;
+
+		vt_kmsg_redirect(data);
+
+		break;
+	case TIOCL_GETFGCONSOLE:
+		/*
+		 * No locking needed as this is a transiently correct return
+		 * anyway if the caller hasn't disabled switching.
+		 */
+		return fg_console;
+	case TIOCL_SCROLLCONSOLE:
+		if (get_user(lines, (s32 __user *)(p+4)))
+			return -EFAULT;
+
+		/*
+		 * Needs the console lock here. Note that lots of other calls
+		 * need fixing before the lock is actually useful!
+		 */
+		console_lock();
+		scrollfront(vc_cons[fg_console].d, lines);
+		console_unlock();
+		break;
+	case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
+		console_lock();
+		ignore_poke = 1;
+		do_blank_screen(0);
+		console_unlock();
+		break;
+	case TIOCL_BLANKEDSCREEN:
+		return console_blanked;
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+/*
+ * /dev/ttyN handling
+ */
+
+static ssize_t con_write(struct tty_struct *tty, const u8 *buf, size_t count)
+{
+	int	retval;
+
+	retval = do_con_write(tty, buf, count);
+	con_flush_chars(tty);
+
+	return retval;
+}
+
+static int con_put_char(struct tty_struct *tty, u8 ch)
+{
+	return do_con_write(tty, &ch, 1);
+}
+
+static unsigned int con_write_room(struct tty_struct *tty)
+{
+	if (tty->flow.stopped)
+		return 0;
+	return 32768;		/* No limit, really; we're not buffering */
+}
+
+/*
+ * con_throttle and con_unthrottle are only used for
+ * paste_selection(), which has to stuff in a large number of
+ * characters...
+ */
+static void con_throttle(struct tty_struct *tty)
+{
+}
+
+static void con_unthrottle(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+
+	wake_up_interruptible(&vc->paste_wait);
+}
+
+/*
+ * Turn the Scroll-Lock LED on when the tty is stopped
+ */
+static void con_stop(struct tty_struct *tty)
+{
+	int console_num;
+	if (!tty)
+		return;
+	console_num = tty->index;
+	if (!vc_cons_allocated(console_num))
+		return;
+	vt_kbd_con_stop(console_num);
+}
+
+/*
+ * Turn the Scroll-Lock LED off when the console is started
+ */
+static void con_start(struct tty_struct *tty)
+{
+	int console_num;
+	if (!tty)
+		return;
+	console_num = tty->index;
+	if (!vc_cons_allocated(console_num))
+		return;
+	vt_kbd_con_start(console_num);
+}
+
+static void con_flush_chars(struct tty_struct *tty)
+{
+	struct vc_data *vc;
+
+	if (in_interrupt())	/* from flush_to_ldisc */
+		return;
+
+	/* if we race with con_close(), vt may be null */
+	console_lock();
+	vc = tty->driver_data;
+	if (vc)
+		set_cursor(vc);
+	console_unlock();
+}
+
+/*
+ * Allocate the console screen memory.
+ */
+static int con_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	unsigned int currcons = tty->index;
+	struct vc_data *vc;
+	int ret;
+
+	console_lock();
+	ret = vc_allocate(currcons);
+	if (ret)
+		goto unlock;
+
+	vc = vc_cons[currcons].d;
+
+	/* Still being freed */
+	if (vc->port.tty) {
+		ret = -ERESTARTSYS;
+		goto unlock;
+	}
+
+	ret = tty_port_install(&vc->port, driver, tty);
+	if (ret)
+		goto unlock;
+
+	tty->driver_data = vc;
+	vc->port.tty = tty;
+	tty_port_get(&vc->port);
+
+	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
+		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
+		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
+	}
+	if (vc->vc_utf)
+		tty->termios.c_iflag |= IUTF8;
+	else
+		tty->termios.c_iflag &= ~IUTF8;
+unlock:
+	console_unlock();
+	return ret;
+}
+
+static int con_open(struct tty_struct *tty, struct file *filp)
+{
+	/* everything done in install */
+	return 0;
+}
+
+
+static void con_close(struct tty_struct *tty, struct file *filp)
+{
+	/* Nothing to do - we defer to shutdown */
+}
+
+static void con_shutdown(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+	BUG_ON(vc == NULL);
+	console_lock();
+	vc->port.tty = NULL;
+	console_unlock();
+}
+
+static void con_cleanup(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+
+	tty_port_put(&vc->port);
+}
+
+static int default_color           = 7; /* white */
+static int default_italic_color    = 2; // green (ASCII)
+static int default_underline_color = 3; // cyan (ASCII)
+module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
+module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
+module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
+
+static void vc_init(struct vc_data *vc, int do_clear)
+{
+	int j, k ;
+
+	set_origin(vc);
+	vc->vc_pos = vc->vc_origin;
+	reset_vc(vc);
+	for (j=k=0; j<16; j++) {
+		vc->vc_palette[k++] = default_red[j] ;
+		vc->vc_palette[k++] = default_grn[j] ;
+		vc->vc_palette[k++] = default_blu[j] ;
+	}
+	vc->vc_def_color       = default_color;
+	vc->vc_ulcolor         = default_underline_color;
+	vc->vc_itcolor         = default_italic_color;
+	vc->vc_halfcolor       = 0x08;   /* grey */
+	init_waitqueue_head(&vc->paste_wait);
+	reset_terminal(vc, do_clear);
+}
+
+/*
+ * This routine initializes console interrupts, and does nothing
+ * else. If you want the screen to clear, call tty_write with
+ * the appropriate escape-sequence.
+ */
+
+static int __init con_init(void)
+{
+	const char *display_desc = NULL;
+	struct vc_data *vc;
+	unsigned int currcons = 0, i;
+
+	console_lock();
+
+	if (!conswitchp)
+		conswitchp = &dummy_con;
+	display_desc = conswitchp->con_startup();
+	if (!display_desc) {
+		fg_console = 0;
+		console_unlock();
+		return 0;
+	}
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == NULL) {
+			con_driver->con = conswitchp;
+			con_driver->desc = display_desc;
+			con_driver->flag = CON_DRIVER_FLAG_INIT;
+			con_driver->first = 0;
+			con_driver->last = MAX_NR_CONSOLES - 1;
+			break;
+		}
+	}
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++)
+		con_driver_map[i] = conswitchp;
+
+	if (blankinterval) {
+		blank_state = blank_normal_wait;
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+	}
+
+	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
+		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
+		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+		tty_port_init(&vc->port);
+		visual_init(vc, currcons, 1);
+		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
+		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
+		vc_init(vc, currcons || !vc->vc_sw->con_save_screen);
+	}
+	currcons = fg_console = 0;
+	master_display_fg = vc = vc_cons[currcons].d;
+	set_origin(vc);
+	save_screen(vc);
+	gotoxy(vc, vc->state.x, vc->state.y);
+	csi_J(vc, 0);
+	update_screen(vc);
+	pr_info("Console: %s %s %dx%d\n",
+		vc->vc_can_do_color ? "colour" : "mono",
+		display_desc, vc->vc_cols, vc->vc_rows);
+
+	console_unlock();
+
+#ifdef CONFIG_VT_CONSOLE
+	register_console(&vt_console_driver);
+#endif
+	return 0;
+}
+console_initcall(con_init);
+
+static const struct tty_operations con_ops = {
+	.install = con_install,
+	.open = con_open,
+	.close = con_close,
+	.write = con_write,
+	.write_room = con_write_room,
+	.put_char = con_put_char,
+	.flush_chars = con_flush_chars,
+	.ioctl = vt_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = vt_compat_ioctl,
+#endif
+	.stop = con_stop,
+	.start = con_start,
+	.throttle = con_throttle,
+	.unthrottle = con_unthrottle,
+	.resize = vt_resize,
+	.shutdown = con_shutdown,
+	.cleanup = con_cleanup,
+};
+
+static struct cdev vc0_cdev;
+
+static ssize_t show_tty_active(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "tty%d\n", fg_console + 1);
+}
+static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
+
+static struct attribute *vt_dev_attrs[] = {
+	&dev_attr_active.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(vt_dev);
+
+int __init vty_init(const struct file_operations *console_fops)
+{
+	cdev_init(&vc0_cdev, console_fops);
+	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
+	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
+		panic("Couldn't register /dev/tty0 driver\n");
+	tty0dev = device_create_with_groups(&tty_class, NULL,
+					    MKDEV(TTY_MAJOR, 0), NULL,
+					    vt_dev_groups, "tty0");
+	if (IS_ERR(tty0dev))
+		tty0dev = NULL;
+
+	vcs_init();
+
+	console_driver = tty_alloc_driver(MAX_NR_CONSOLES, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_RESET_TERMIOS);
+	if (IS_ERR(console_driver))
+		panic("Couldn't allocate console driver\n");
+
+	console_driver->name = "tty";
+	console_driver->name_base = 1;
+	console_driver->major = TTY_MAJOR;
+	console_driver->minor_start = 1;
+	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
+	console_driver->init_termios = tty_std_termios;
+	if (default_utf8)
+		console_driver->init_termios.c_iflag |= IUTF8;
+	tty_set_operations(console_driver, &con_ops);
+	if (tty_register_driver(console_driver))
+		panic("Couldn't register console driver\n");
+	kbd_init();
+	console_map_init();
+#ifdef CONFIG_MDA_CONSOLE
+	mda_console_init();
+#endif
+	return 0;
+}
+
+static struct class *vtconsole_class;
+
+static int do_bind_con_driver(const struct consw *csw, int first, int last,
+			   int deflt)
+{
+	struct module *owner = csw->owner;
+	const char *desc = NULL;
+	struct con_driver *con_driver;
+	int i, j = -1, k = -1, retval = -ENODEV;
+
+	if (!try_module_get(owner))
+		return -ENODEV;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	/* check if driver is registered */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw) {
+			desc = con_driver->desc;
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval)
+		goto err;
+
+	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
+		csw->con_startup();
+		con_driver->flag |= CON_DRIVER_FLAG_INIT;
+	}
+
+	if (deflt) {
+		if (conswitchp)
+			module_put(conswitchp->owner);
+
+		__module_get(owner);
+		conswitchp = csw;
+	}
+
+	first = max(first, con_driver->first);
+	last = min(last, con_driver->last);
+
+	for (i = first; i <= last; i++) {
+		int old_was_color;
+		struct vc_data *vc = vc_cons[i].d;
+
+		if (con_driver_map[i])
+			module_put(con_driver_map[i]->owner);
+		__module_get(owner);
+		con_driver_map[i] = csw;
+
+		if (!vc || !vc->vc_sw)
+			continue;
+
+		j = i;
+
+		if (con_is_visible(vc)) {
+			k = i;
+			save_screen(vc);
+		}
+
+		old_was_color = vc->vc_can_do_color;
+		vc->vc_sw->con_deinit(vc);
+		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
+		visual_init(vc, i, 0);
+		set_origin(vc);
+		update_attr(vc);
+
+		/* If the console changed between mono <-> color, then
+		 * the attributes in the screenbuf will be wrong.  The
+		 * following resets all attributes to something sane.
+		 */
+		if (old_was_color != vc->vc_can_do_color)
+			clear_buffer_attributes(vc);
+	}
+
+	pr_info("Console: switching ");
+	if (!deflt)
+		pr_cont("consoles %d-%d ", first + 1, last + 1);
+	if (j >= 0) {
+		struct vc_data *vc = vc_cons[j].d;
+
+		pr_cont("to %s %s %dx%d\n",
+			vc->vc_can_do_color ? "colour" : "mono",
+			desc, vc->vc_cols, vc->vc_rows);
+
+		if (k >= 0) {
+			vc = vc_cons[k].d;
+			update_screen(vc);
+		}
+	} else {
+		pr_cont("to %s\n", desc);
+	}
+
+	retval = 0;
+err:
+	module_put(owner);
+	return retval;
+};
+
+
+#ifdef CONFIG_VT_HW_CONSOLE_BINDING
+int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
+{
+	struct module *owner = csw->owner;
+	const struct consw *defcsw = NULL;
+	struct con_driver *con_driver = NULL, *con_back = NULL;
+	int i, retval = -ENODEV;
+
+	if (!try_module_get(owner))
+		return -ENODEV;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	/* check if driver is registered and if it is unbindable */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw &&
+		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval)
+		goto err;
+
+	retval = -ENODEV;
+
+	/* check if backup driver exists */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_back = &registered_con_driver[i];
+
+		if (con_back->con && con_back->con != csw) {
+			defcsw = con_back->con;
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval)
+		goto err;
+
+	if (!con_is_bound(csw))
+		goto err;
+
+	first = max(first, con_driver->first);
+	last = min(last, con_driver->last);
+
+	for (i = first; i <= last; i++) {
+		if (con_driver_map[i] == csw) {
+			module_put(csw->owner);
+			con_driver_map[i] = NULL;
+		}
+	}
+
+	if (!con_is_bound(defcsw)) {
+		const struct consw *defconsw = conswitchp;
+
+		defcsw->con_startup();
+		con_back->flag |= CON_DRIVER_FLAG_INIT;
+		/*
+		 * vgacon may change the default driver to point
+		 * to dummycon, we restore it here...
+		 */
+		conswitchp = defconsw;
+	}
+
+	if (!con_is_bound(csw))
+		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
+
+	/* ignore return value, binding should not fail */
+	do_bind_con_driver(defcsw, first, last, deflt);
+err:
+	module_put(owner);
+	return retval;
+
+}
+EXPORT_SYMBOL_GPL(do_unbind_con_driver);
+
+static int vt_bind(struct con_driver *con)
+{
+	const struct consw *defcsw = NULL, *csw = NULL;
+	int i, more = 1, first = -1, last = -1, deflt = 0;
+
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
+		goto err;
+
+	csw = con->con;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con = &registered_con_driver[i];
+
+		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
+			defcsw = con->con;
+			break;
+		}
+	}
+
+	if (!defcsw)
+		goto err;
+
+	while (more) {
+		more = 0;
+
+		for (i = con->first; i <= con->last; i++) {
+			if (con_driver_map[i] == defcsw) {
+				if (first == -1)
+					first = i;
+				last = i;
+				more = 1;
+			} else if (first != -1)
+				break;
+		}
+
+		if (first == 0 && last == MAX_NR_CONSOLES -1)
+			deflt = 1;
+
+		if (first != -1)
+			do_bind_con_driver(csw, first, last, deflt);
+
+		first = -1;
+		last = -1;
+		deflt = 0;
+	}
+
+err:
+	return 0;
+}
+
+static int vt_unbind(struct con_driver *con)
+{
+	const struct consw *csw = NULL;
+	int i, more = 1, first = -1, last = -1, deflt = 0;
+	int ret;
+
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
+		goto err;
+
+	csw = con->con;
+
+	while (more) {
+		more = 0;
+
+		for (i = con->first; i <= con->last; i++) {
+			if (con_driver_map[i] == csw) {
+				if (first == -1)
+					first = i;
+				last = i;
+				more = 1;
+			} else if (first != -1)
+				break;
+		}
+
+		if (first == 0 && last == MAX_NR_CONSOLES -1)
+			deflt = 1;
+
+		if (first != -1) {
+			ret = do_unbind_con_driver(csw, first, last, deflt);
+			if (ret != 0)
+				return ret;
+		}
+
+		first = -1;
+		last = -1;
+		deflt = 0;
+	}
+
+err:
+	return 0;
+}
+#else
+static inline int vt_bind(struct con_driver *con)
+{
+	return 0;
+}
+static inline int vt_unbind(struct con_driver *con)
+{
+	return 0;
+}
+#endif /* CONFIG_VT_HW_CONSOLE_BINDING */
+
+static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+	int bind = simple_strtoul(buf, NULL, 0);
+
+	console_lock();
+
+	if (bind)
+		vt_bind(con);
+	else
+		vt_unbind(con);
+
+	console_unlock();
+
+	return count;
+}
+
+static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+	int bind;
+
+	console_lock();
+	bind = con_is_bound(con->con);
+	console_unlock();
+
+	return sysfs_emit(buf, "%i\n", bind);
+}
+
+static ssize_t show_name(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s %s\n",
+			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
+			 con->desc);
+
+}
+
+static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static struct attribute *con_dev_attrs[] = {
+	&dev_attr_bind.attr,
+	&dev_attr_name.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(con_dev);
+
+static int vtconsole_init_device(struct con_driver *con)
+{
+	con->flag |= CON_DRIVER_FLAG_ATTR;
+	return 0;
+}
+
+static void vtconsole_deinit_device(struct con_driver *con)
+{
+	con->flag &= ~CON_DRIVER_FLAG_ATTR;
+}
+
+/**
+ * con_is_bound - checks if driver is bound to the console
+ * @csw: console driver
+ *
+ * RETURNS: zero if unbound, nonzero if bound
+ *
+ * Drivers can call this and if zero, they should release
+ * all resources allocated on con_startup()
+ */
+int con_is_bound(const struct consw *csw)
+{
+	int i, bound = 0;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		if (con_driver_map[i] == csw) {
+			bound = 1;
+			break;
+		}
+	}
+
+	return bound;
+}
+EXPORT_SYMBOL(con_is_bound);
+
+/**
+ * con_is_visible - checks whether the current console is visible
+ * @vc: virtual console
+ *
+ * RETURNS: zero if not visible, nonzero if visible
+ */
+bool con_is_visible(const struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	return *vc->vc_display_fg == vc;
+}
+EXPORT_SYMBOL(con_is_visible);
+
+/**
+ * con_debug_enter - prepare the console for the kernel debugger
+ * @vc: virtual console
+ *
+ * Called when the console is taken over by the kernel debugger, this
+ * function needs to save the current console state, then put the console
+ * into a state suitable for the kernel debugger.
+ *
+ * RETURNS:
+ * Zero on success, nonzero if a failure occurred when trying to prepare
+ * the console for the debugger.
+ */
+int con_debug_enter(struct vc_data *vc)
+{
+	int ret = 0;
+
+	saved_fg_console = fg_console;
+	saved_last_console = last_console;
+	saved_want_console = want_console;
+	saved_vc_mode = vc->vc_mode;
+	saved_console_blanked = console_blanked;
+	vc->vc_mode = KD_TEXT;
+	console_blanked = 0;
+	if (vc->vc_sw->con_debug_enter)
+		ret = vc->vc_sw->con_debug_enter(vc);
+#ifdef CONFIG_KGDB_KDB
+	/* Set the initial LINES variable if it is not already set */
+	if (vc->vc_rows < 999) {
+		int linecount;
+		char lns[4];
+		const char *setargs[3] = {
+			"set",
+			"LINES",
+			lns,
+		};
+		if (kdbgetintenv(setargs[0], &linecount)) {
+			snprintf(lns, 4, "%i", vc->vc_rows);
+			kdb_set(2, setargs);
+		}
+	}
+	if (vc->vc_cols < 999) {
+		int colcount;
+		char cols[4];
+		const char *setargs[3] = {
+			"set",
+			"COLUMNS",
+			cols,
+		};
+		if (kdbgetintenv(setargs[0], &colcount)) {
+			snprintf(cols, 4, "%i", vc->vc_cols);
+			kdb_set(2, setargs);
+		}
+	}
+#endif /* CONFIG_KGDB_KDB */
+	return ret;
+}
+EXPORT_SYMBOL_GPL(con_debug_enter);
+
+/**
+ * con_debug_leave - restore console state
+ *
+ * Restore the console state to what it was before the kernel debugger
+ * was invoked.
+ *
+ * RETURNS:
+ * Zero on success, nonzero if a failure occurred when trying to restore
+ * the console.
+ */
+int con_debug_leave(void)
+{
+	struct vc_data *vc;
+	int ret = 0;
+
+	fg_console = saved_fg_console;
+	last_console = saved_last_console;
+	want_console = saved_want_console;
+	console_blanked = saved_console_blanked;
+	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
+
+	vc = vc_cons[fg_console].d;
+	if (vc->vc_sw->con_debug_leave)
+		ret = vc->vc_sw->con_debug_leave(vc);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(con_debug_leave);
+
+static int do_register_con_driver(const struct consw *csw, int first, int last)
+{
+	struct module *owner = csw->owner;
+	struct con_driver *con_driver;
+	const char *desc;
+	int i, retval;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!try_module_get(owner))
+		return -ENODEV;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		/* already registered */
+		if (con_driver->con == csw) {
+			retval = -EBUSY;
+			goto err;
+		}
+	}
+
+	desc = csw->con_startup();
+	if (!desc) {
+		retval = -ENODEV;
+		goto err;
+	}
+
+	retval = -EINVAL;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == NULL &&
+		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
+			con_driver->con = csw;
+			con_driver->desc = desc;
+			con_driver->node = i;
+			con_driver->flag = CON_DRIVER_FLAG_MODULE |
+			                   CON_DRIVER_FLAG_INIT;
+			con_driver->first = first;
+			con_driver->last = last;
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval)
+		goto err;
+
+	con_driver->dev =
+		device_create_with_groups(vtconsole_class, NULL,
+					  MKDEV(0, con_driver->node),
+					  con_driver, con_dev_groups,
+					  "vtcon%i", con_driver->node);
+	if (IS_ERR(con_driver->dev)) {
+		pr_warn("Unable to create device for %s; errno = %ld\n",
+			con_driver->desc, PTR_ERR(con_driver->dev));
+		con_driver->dev = NULL;
+	} else {
+		vtconsole_init_device(con_driver);
+	}
+
+err:
+	module_put(owner);
+	return retval;
+}
+
+
+/**
+ * do_unregister_con_driver - unregister console driver from console layer
+ * @csw: console driver
+ *
+ * DESCRIPTION: All drivers that registers to the console layer must
+ * call this function upon exit, or if the console driver is in a state
+ * where it won't be able to handle console services, such as the
+ * framebuffer console without loaded framebuffer drivers.
+ *
+ * The driver must unbind first prior to unregistration.
+ */
+int do_unregister_con_driver(const struct consw *csw)
+{
+	int i;
+
+	/* cannot unregister a bound driver */
+	if (con_is_bound(csw))
+		return -EBUSY;
+
+	if (csw == conswitchp)
+		return -EINVAL;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw) {
+			/*
+			 * Defer the removal of the sysfs entries since that
+			 * will acquire the kernfs s_active lock and we can't
+			 * acquire this lock while holding the console lock:
+			 * the unbind sysfs entry imposes already the opposite
+			 * order. Reset con already here to prevent any later
+			 * lookup to succeed and mark this slot as zombie, so
+			 * it won't get reused until we complete the removal
+			 * in the deferred work.
+			 */
+			con_driver->con = NULL;
+			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
+			schedule_work(&con_driver_unregister_work);
+
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(do_unregister_con_driver);
+
+static void con_driver_unregister_callback(struct work_struct *ignored)
+{
+	int i;
+
+	console_lock();
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
+			continue;
+
+		console_unlock();
+
+		vtconsole_deinit_device(con_driver);
+		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
+
+		console_lock();
+
+		if (WARN_ON_ONCE(con_driver->con))
+			con_driver->con = NULL;
+		con_driver->desc = NULL;
+		con_driver->dev = NULL;
+		con_driver->node = 0;
+		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
+		con_driver->flag = 0;
+		con_driver->first = 0;
+		con_driver->last = 0;
+	}
+
+	console_unlock();
+}
+
+/*
+ *	If we support more console drivers, this function is used
+ *	when a driver wants to take over some existing consoles
+ *	and become default driver for newly opened ones.
+ *
+ *	do_take_over_console is basically a register followed by bind
+ */
+int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
+{
+	int err;
+
+	err = do_register_con_driver(csw, first, last);
+	/*
+	 * If we get an busy error we still want to bind the console driver
+	 * and return success, as we may have unbound the console driver
+	 * but not unregistered it.
+	 */
+	if (err == -EBUSY)
+		err = 0;
+	if (!err)
+		do_bind_con_driver(csw, first, last, deflt);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(do_take_over_console);
+
+
+/*
+ * give_up_console is a wrapper to unregister_con_driver. It will only
+ * work if driver is fully unbound.
+ */
+void give_up_console(const struct consw *csw)
+{
+	console_lock();
+	do_unregister_con_driver(csw);
+	console_unlock();
+}
+EXPORT_SYMBOL(give_up_console);
+
+static int __init vtconsole_class_init(void)
+{
+	int i;
+
+	vtconsole_class = class_create("vtconsole");
+	if (IS_ERR(vtconsole_class)) {
+		pr_warn("Unable to create vt console class; errno = %ld\n",
+			PTR_ERR(vtconsole_class));
+		vtconsole_class = NULL;
+	}
+
+	/* Add system drivers to sysfs */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con = &registered_con_driver[i];
+
+		if (con->con && !con->dev) {
+			con->dev =
+				device_create_with_groups(vtconsole_class, NULL,
+							  MKDEV(0, con->node),
+							  con, con_dev_groups,
+							  "vtcon%i", con->node);
+
+			if (IS_ERR(con->dev)) {
+				pr_warn("Unable to create device for %s; errno = %ld\n",
+					con->desc, PTR_ERR(con->dev));
+				con->dev = NULL;
+			} else {
+				vtconsole_init_device(con);
+			}
+		}
+	}
+
+	return 0;
+}
+postcore_initcall(vtconsole_class_init);
+
+/*
+ *	Screen blanking
+ */
+
+static int set_vesa_blanking(char __user *p)
+{
+	unsigned int mode;
+
+	if (get_user(mode, p + 1))
+		return -EFAULT;
+
+	vesa_blank_mode = (mode < 4) ? mode : 0;
+	return 0;
+}
+
+void do_blank_screen(int entering_gfx)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	int i;
+
+	might_sleep();
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (console_blanked) {
+		if (blank_state == blank_vesa_wait) {
+			blank_state = blank_off;
+			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
+		}
+		return;
+	}
+
+	/* entering graphics mode? */
+	if (entering_gfx) {
+		hide_cursor(vc);
+		save_screen(vc);
+		vc->vc_sw->con_blank(vc, -1, 1);
+		console_blanked = fg_console + 1;
+		blank_state = blank_off;
+		set_origin(vc);
+		return;
+	}
+
+	blank_state = blank_off;
+
+	/* don't blank graphics */
+	if (vc->vc_mode != KD_TEXT) {
+		console_blanked = fg_console + 1;
+		return;
+	}
+
+	hide_cursor(vc);
+	del_timer_sync(&console_timer);
+	blank_timer_expired = 0;
+
+	save_screen(vc);
+	/* In case we need to reset origin, blanking hook returns 1 */
+	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
+	console_blanked = fg_console + 1;
+	if (i)
+		set_origin(vc);
+
+	if (console_blank_hook && console_blank_hook(1))
+		return;
+
+	if (vesa_off_interval && vesa_blank_mode) {
+		blank_state = blank_vesa_wait;
+		mod_timer(&console_timer, jiffies + vesa_off_interval);
+	}
+	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
+}
+EXPORT_SYMBOL(do_blank_screen);
+
+/*
+ * Called by timer as well as from vt_console_driver
+ */
+void do_unblank_screen(int leaving_gfx)
+{
+	struct vc_data *vc;
+
+	/* This should now always be called from a "sane" (read: can schedule)
+	 * context for the sake of the low level drivers, except in the special
+	 * case of oops_in_progress
+	 */
+	if (!oops_in_progress)
+		might_sleep();
+
+	WARN_CONSOLE_UNLOCKED();
+
+	ignore_poke = 0;
+	if (!console_blanked)
+		return;
+	if (!vc_cons_allocated(fg_console)) {
+		/* impossible */
+		pr_warn("unblank_screen: tty %d not allocated ??\n",
+			fg_console + 1);
+		return;
+	}
+	vc = vc_cons[fg_console].d;
+	if (vc->vc_mode != KD_TEXT)
+		return; /* but leave console_blanked != 0 */
+
+	if (blankinterval) {
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+		blank_state = blank_normal_wait;
+	}
+
+	console_blanked = 0;
+	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
+		/* Low-level driver cannot restore -> do it ourselves */
+		update_screen(vc);
+	if (console_blank_hook)
+		console_blank_hook(0);
+	set_palette(vc);
+	set_cursor(vc);
+	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
+}
+EXPORT_SYMBOL(do_unblank_screen);
+
+/*
+ * This is called by the outside world to cause a forced unblank, mostly for
+ * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
+ * call it with 1 as an argument and so force a mode restore... that may kill
+ * X or at least garbage the screen but would also make the Oops visible...
+ */
+static void unblank_screen(void)
+{
+	do_unblank_screen(0);
+}
+
+/*
+ * We defer the timer blanking to work queue so it can take the console mutex
+ * (console operations can still happen at irq time, but only from printk which
+ * has the console mutex. Not perfect yet, but better than no locking
+ */
+static void blank_screen_t(struct timer_list *unused)
+{
+	blank_timer_expired = 1;
+	schedule_work(&console_work);
+}
+
+void poke_blanked_console(void)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	/* Add this so we quickly catch whoever might call us in a non
+	 * safe context. Nowadays, unblank_screen() isn't to be called in
+	 * atomic contexts and is allowed to schedule (with the special case
+	 * of oops_in_progress, but that isn't of any concern for this
+	 * function. --BenH.
+	 */
+	might_sleep();
+
+	/* This isn't perfectly race free, but a race here would be mostly harmless,
+	 * at worst, we'll do a spurious blank and it's unlikely
+	 */
+	del_timer(&console_timer);
+	blank_timer_expired = 0;
+
+	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
+		return;
+	if (console_blanked)
+		unblank_screen();
+	else if (blankinterval) {
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+		blank_state = blank_normal_wait;
+	}
+}
+
+/*
+ *	Palettes
+ */
+
+static void set_palette(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
+		vc->vc_sw->con_set_palette(vc, color_table);
+}
+
+/*
+ * Load palette into the DAC registers. arg points to a colour
+ * map, 3 bytes per colour, 16 colours, range from 0 to 255.
+ */
+
+int con_set_cmap(unsigned char __user *arg)
+{
+	int i, j, k;
+	unsigned char colormap[3*16];
+
+	if (copy_from_user(colormap, arg, sizeof(colormap)))
+		return -EFAULT;
+
+	console_lock();
+	for (i = k = 0; i < 16; i++) {
+		default_red[i] = colormap[k++];
+		default_grn[i] = colormap[k++];
+		default_blu[i] = colormap[k++];
+	}
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		if (!vc_cons_allocated(i))
+			continue;
+		for (j = k = 0; j < 16; j++) {
+			vc_cons[i].d->vc_palette[k++] = default_red[j];
+			vc_cons[i].d->vc_palette[k++] = default_grn[j];
+			vc_cons[i].d->vc_palette[k++] = default_blu[j];
+		}
+		set_palette(vc_cons[i].d);
+	}
+	console_unlock();
+
+	return 0;
+}
+
+int con_get_cmap(unsigned char __user *arg)
+{
+	int i, k;
+	unsigned char colormap[3*16];
+
+	console_lock();
+	for (i = k = 0; i < 16; i++) {
+		colormap[k++] = default_red[i];
+		colormap[k++] = default_grn[i];
+		colormap[k++] = default_blu[i];
+	}
+	console_unlock();
+
+	if (copy_to_user(arg, colormap, sizeof(colormap)))
+		return -EFAULT;
+
+	return 0;
+}
+
+void reset_palette(struct vc_data *vc)
+{
+	int j, k;
+	for (j=k=0; j<16; j++) {
+		vc->vc_palette[k++] = default_red[j];
+		vc->vc_palette[k++] = default_grn[j];
+		vc->vc_palette[k++] = default_blu[j];
+	}
+	set_palette(vc);
+}
+
+/*
+ *  Font switching
+ *
+ *  Currently we only support fonts up to 128 pixels wide, at a maximum height
+ *  of 128 pixels. Userspace fontdata may have to be stored with 32 bytes
+ *  (shorts/ints, depending on width) reserved for each character which is
+ *  kinda wasty, but this is done in order to maintain compatibility with the
+ *  EGA/VGA fonts. It is up to the actual low-level console-driver convert data
+ *  into its favorite format (maybe we should add a `fontoffset' field to the
+ *  `display' structure so we won't have to convert the fontdata all the time.
+ *  /Jes
+ */
+
+#define max_font_width	64
+#define max_font_height	128
+#define max_font_glyphs	512
+#define max_font_size	(max_font_glyphs*max_font_width*max_font_height)
+
+static int con_font_get(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font;
+	int rc = -EINVAL;
+	int c;
+	unsigned int vpitch = op->op == KD_FONT_OP_GET_TALL ? op->height : 32;
+
+	if (vpitch > max_font_height)
+		return -EINVAL;
+
+	if (op->data) {
+		font.data = kvmalloc(max_font_size, GFP_KERNEL);
+		if (!font.data)
+			return -ENOMEM;
+	} else
+		font.data = NULL;
+
+	console_lock();
+	if (vc->vc_mode != KD_TEXT)
+		rc = -EINVAL;
+	else if (vc->vc_sw->con_font_get)
+		rc = vc->vc_sw->con_font_get(vc, &font, vpitch);
+	else
+		rc = -ENOSYS;
+	console_unlock();
+
+	if (rc)
+		goto out;
+
+	c = (font.width+7)/8 * vpitch * font.charcount;
+
+	if (op->data && font.charcount > op->charcount)
+		rc = -ENOSPC;
+	if (font.width > op->width || font.height > op->height)
+		rc = -ENOSPC;
+	if (rc)
+		goto out;
+
+	op->height = font.height;
+	op->width = font.width;
+	op->charcount = font.charcount;
+
+	if (op->data && copy_to_user(op->data, font.data, c))
+		rc = -EFAULT;
+
+out:
+	kvfree(font.data);
+	return rc;
+}
+
+static int con_font_set(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font;
+	int rc = -EINVAL;
+	int size;
+	unsigned int vpitch = op->op == KD_FONT_OP_SET_TALL ? op->height : 32;
+
+	if (vc->vc_mode != KD_TEXT)
+		return -EINVAL;
+	if (!op->data)
+		return -EINVAL;
+	if (op->charcount > max_font_glyphs)
+		return -EINVAL;
+	if (op->width <= 0 || op->width > max_font_width || !op->height ||
+	    op->height > max_font_height)
+		return -EINVAL;
+	if (vpitch < op->height)
+		return -EINVAL;
+	size = (op->width+7)/8 * vpitch * op->charcount;
+	if (size > max_font_size)
+		return -ENOSPC;
+
+	font.data = memdup_user(op->data, size);
+	if (IS_ERR(font.data))
+		return PTR_ERR(font.data);
+
+	font.charcount = op->charcount;
+	font.width = op->width;
+	font.height = op->height;
+
+	console_lock();
+	if (vc->vc_mode != KD_TEXT)
+		rc = -EINVAL;
+	else if (vc->vc_sw->con_font_set) {
+		if (vc_is_sel(vc))
+			clear_selection();
+		rc = vc->vc_sw->con_font_set(vc, &font, vpitch, op->flags);
+	} else
+		rc = -ENOSYS;
+	console_unlock();
+	kfree(font.data);
+	return rc;
+}
+
+static int con_font_default(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font = {.width = op->width, .height = op->height};
+	char name[MAX_FONT_NAME];
+	char *s = name;
+	int rc;
+
+
+	if (!op->data)
+		s = NULL;
+	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
+		return -EFAULT;
+	else
+		name[MAX_FONT_NAME - 1] = 0;
+
+	console_lock();
+	if (vc->vc_mode != KD_TEXT) {
+		console_unlock();
+		return -EINVAL;
+	}
+	if (vc->vc_sw->con_font_default) {
+		if (vc_is_sel(vc))
+			clear_selection();
+		rc = vc->vc_sw->con_font_default(vc, &font, s);
+	} else
+		rc = -ENOSYS;
+	console_unlock();
+	if (!rc) {
+		op->width = font.width;
+		op->height = font.height;
+	}
+	return rc;
+}
+
+int con_font_op(struct vc_data *vc, struct console_font_op *op)
+{
+	switch (op->op) {
+	case KD_FONT_OP_SET:
+	case KD_FONT_OP_SET_TALL:
+		return con_font_set(vc, op);
+	case KD_FONT_OP_GET:
+	case KD_FONT_OP_GET_TALL:
+		return con_font_get(vc, op);
+	case KD_FONT_OP_SET_DEFAULT:
+		return con_font_default(vc, op);
+	case KD_FONT_OP_COPY:
+		/* was buggy and never really used */
+		return -EINVAL;
+	}
+	return -ENOSYS;
+}
+
+/*
+ *	Interface exported to selection and vcs.
+ */
+
+/* used by selection */
+u16 screen_glyph(const struct vc_data *vc, int offset)
+{
+	u16 w = scr_readw(screenpos(vc, offset, true));
+	u16 c = w & 0xff;
+
+	if (w & vc->vc_hi_font_mask)
+		c |= 0x100;
+	return c;
+}
+EXPORT_SYMBOL_GPL(screen_glyph);
+
+u32 screen_glyph_unicode(const struct vc_data *vc, int n)
+{
+	u32 **uni_lines = vc->vc_uni_lines;
+
+	if (uni_lines)
+		return uni_lines[n / vc->vc_cols][n % vc->vc_cols];
+
+	return inverse_translate(vc, screen_glyph(vc, n * 2), true);
+}
+EXPORT_SYMBOL_GPL(screen_glyph_unicode);
+
+/* used by vcs - note the word offset */
+unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
+{
+	return screenpos(vc, 2 * w_offset, viewed);
+}
+EXPORT_SYMBOL_GPL(screen_pos);
+
+void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
+{
+	/* clamp values if they don't fit */
+	xy[0] = min(vc->state.x, 0xFFu);
+	xy[1] = min(vc->state.y, 0xFFu);
+}
+
+void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
+{
+	hide_cursor(vc);
+	gotoxy(vc, xy[0], xy[1]);
+	set_cursor(vc);
+}
+
+u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
+{
+	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
+		return softcursor_original;
+	return scr_readw(org);
+}
+
+void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
+{
+	scr_writew(val, org);
+	if ((unsigned long)org == vc->vc_pos) {
+		softcursor_original = -1;
+		add_softcursor(vc);
+	}
+}
+
+void vcs_scr_updated(struct vc_data *vc)
+{
+	notify_update(vc);
+}
+
+void vc_scrolldelta_helper(struct vc_data *c, int lines,
+		unsigned int rolled_over, void *base, unsigned int size)
+{
+	unsigned long ubase = (unsigned long)base;
+	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
+	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
+	ptrdiff_t origin = (void *)c->vc_origin - base;
+	int margin = c->vc_size_row * 4;
+	int from, wrap, from_off, avail;
+
+	/* Turn scrollback off */
+	if (!lines) {
+		c->vc_visible_origin = c->vc_origin;
+		return;
+	}
+
+	/* Do we have already enough to allow jumping from 0 to the end? */
+	if (rolled_over > scr_end + margin) {
+		from = scr_end;
+		wrap = rolled_over + c->vc_size_row;
+	} else {
+		from = 0;
+		wrap = size;
+	}
+
+	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
+	avail = (origin - from + wrap) % wrap;
+
+	/* Only a little piece would be left? Show all incl. the piece! */
+	if (avail < 2 * margin)
+		margin = 0;
+	if (from_off < margin)
+		from_off = 0;
+	if (from_off > avail - margin)
+		from_off = avail;
+
+	c->vc_visible_origin = ubase + (from + from_off) % wrap;
+}
+EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
new file mode 100644
index 000000000..8c685b501
--- /dev/null
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -0,0 +1,1323 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1992 obz under the linux copyright
+ *
+ *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
+ *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
+ *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
+ *  Some code moved for less code duplication - Andi Kleen - Mar 1997
+ *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/sched/signal.h>
+#include <linux/tty.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/compat.h>
+#include <linux/module.h>
+#include <linux/kd.h>
+#include <linux/vt.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/console.h>
+#include <linux/consolemap.h>
+#include <linux/signal.h>
+#include <linux/suspend.h>
+#include <linux/timex.h>
+
+#include <asm/io.h>
+#include <linux/uaccess.h>
+
+#include <linux/nospec.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/kbd_diacr.h>
+#include <linux/selection.h>
+
+bool vt_dont_switch;
+
+static inline bool vt_in_use(unsigned int i)
+{
+	const struct vc_data *vc = vc_cons[i].d;
+
+	/*
+	 * console_lock must be held to prevent the vc from being deallocated
+	 * while we're checking whether it's in-use.
+	 */
+	WARN_CONSOLE_UNLOCKED();
+
+	return vc && kref_read(&vc->port.kref) > 1;
+}
+
+static inline bool vt_busy(int i)
+{
+	if (vt_in_use(i))
+		return true;
+	if (i == fg_console)
+		return true;
+	if (vc_is_sel(vc_cons[i].d))
+		return true;
+
+	return false;
+}
+
+/*
+ * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
+ * experimentation and study of X386 SYSV handling.
+ *
+ * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
+ * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
+ * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
+ * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
+ * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
+ * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
+ * to the current console is done by the main ioctl code.
+ */
+
+#ifdef CONFIG_X86
+#include <asm/syscalls.h>
+#endif
+
+static void complete_change_console(struct vc_data *vc);
+
+/*
+ *	User space VT_EVENT handlers
+ */
+
+struct vt_event_wait {
+	struct list_head list;
+	struct vt_event event;
+	int done;
+};
+
+static LIST_HEAD(vt_events);
+static DEFINE_SPINLOCK(vt_event_lock);
+static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
+
+/**
+ *	vt_event_post
+ *	@event: the event that occurred
+ *	@old: old console
+ *	@new: new console
+ *
+ *	Post an VT event to interested VT handlers
+ */
+
+void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
+{
+	struct list_head *pos, *head;
+	unsigned long flags;
+	int wake = 0;
+
+	spin_lock_irqsave(&vt_event_lock, flags);
+	head = &vt_events;
+
+	list_for_each(pos, head) {
+		struct vt_event_wait *ve = list_entry(pos,
+						struct vt_event_wait, list);
+		if (!(ve->event.event & event))
+			continue;
+		ve->event.event = event;
+		/* kernel view is consoles 0..n-1, user space view is
+		   console 1..n with 0 meaning current, so we must bias */
+		ve->event.oldev = old + 1;
+		ve->event.newev = new + 1;
+		wake = 1;
+		ve->done = 1;
+	}
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+	if (wake)
+		wake_up_interruptible(&vt_event_waitqueue);
+}
+
+static void __vt_event_queue(struct vt_event_wait *vw)
+{
+	unsigned long flags;
+	/* Prepare the event */
+	INIT_LIST_HEAD(&vw->list);
+	vw->done = 0;
+	/* Queue our event */
+	spin_lock_irqsave(&vt_event_lock, flags);
+	list_add(&vw->list, &vt_events);
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+}
+
+static void __vt_event_wait(struct vt_event_wait *vw)
+{
+	/* Wait for it to pass */
+	wait_event_interruptible(vt_event_waitqueue, vw->done);
+}
+
+static void __vt_event_dequeue(struct vt_event_wait *vw)
+{
+	unsigned long flags;
+
+	/* Dequeue it */
+	spin_lock_irqsave(&vt_event_lock, flags);
+	list_del(&vw->list);
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+}
+
+/**
+ *	vt_event_wait		-	wait for an event
+ *	@vw: our event
+ *
+ *	Waits for an event to occur which completes our vt_event_wait
+ *	structure. On return the structure has wv->done set to 1 for success
+ *	or 0 if some event such as a signal ended the wait.
+ */
+
+static void vt_event_wait(struct vt_event_wait *vw)
+{
+	__vt_event_queue(vw);
+	__vt_event_wait(vw);
+	__vt_event_dequeue(vw);
+}
+
+/**
+ *	vt_event_wait_ioctl	-	event ioctl handler
+ *	@event: argument to ioctl (the event)
+ *
+ *	Implement the VT_WAITEVENT ioctl using the VT event interface
+ */
+
+static int vt_event_wait_ioctl(struct vt_event __user *event)
+{
+	struct vt_event_wait vw;
+
+	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
+		return -EFAULT;
+	/* Highest supported event for now */
+	if (vw.event.event & ~VT_MAX_EVENT)
+		return -EINVAL;
+
+	vt_event_wait(&vw);
+	/* If it occurred report it */
+	if (vw.done) {
+		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
+			return -EFAULT;
+		return 0;
+	}
+	return -EINTR;
+}
+
+/**
+ *	vt_waitactive	-	active console wait
+ *	@n: new console
+ *
+ *	Helper for event waits. Used to implement the legacy
+ *	event waiting ioctls in terms of events
+ */
+
+int vt_waitactive(int n)
+{
+	struct vt_event_wait vw;
+	do {
+		vw.event.event = VT_EVENT_SWITCH;
+		__vt_event_queue(&vw);
+		if (n == fg_console + 1) {
+			__vt_event_dequeue(&vw);
+			break;
+		}
+		__vt_event_wait(&vw);
+		__vt_event_dequeue(&vw);
+		if (vw.done == 0)
+			return -EINTR;
+	} while (vw.event.newev != n);
+	return 0;
+}
+
+/*
+ * these are the valid i/o ports we're allowed to change. they map all the
+ * video ports
+ */
+#define GPFIRST 0x3b4
+#define GPLAST 0x3df
+#define GPNUM (GPLAST - GPFIRST + 1)
+
+/*
+ * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole
+ * lot. i'm not sure if it should do any restoration of modes or what...
+ *
+ * XXX It should at least call into the driver, fbdev's definitely need to
+ * restore their engine state. --BenH
+ *
+ * Called with the console lock held.
+ */
+static int vt_kdsetmode(struct vc_data *vc, unsigned long mode)
+{
+	switch (mode) {
+	case KD_GRAPHICS:
+		break;
+	case KD_TEXT0:
+	case KD_TEXT1:
+		mode = KD_TEXT;
+		fallthrough;
+	case KD_TEXT:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (vc->vc_mode == mode)
+		return 0;
+
+	vc->vc_mode = mode;
+	if (vc->vc_num != fg_console)
+		return 0;
+
+	/* explicitly blank/unblank the screen if switching modes */
+	if (mode == KD_TEXT)
+		do_unblank_screen(1);
+	else
+		do_blank_screen(1);
+
+	return 0;
+}
+
+static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
+		unsigned long arg, bool perm)
+{
+	struct vc_data *vc = tty->driver_data;
+	void __user *up = (void __user *)arg;
+	unsigned int console = vc->vc_num;
+	int ret;
+
+	switch (cmd) {
+	case KIOCSOUND:
+		if (!perm)
+			return -EPERM;
+		/*
+		 * The use of PIT_TICK_RATE is historic, it used to be
+		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
+		 * and 2.6.36, which was a minor but unfortunate ABI
+		 * change. kd_mksound is locked by the input layer.
+		 */
+		if (arg)
+			arg = PIT_TICK_RATE / arg;
+		kd_mksound(arg, 0);
+		break;
+
+	case KDMKTONE:
+		if (!perm)
+			return -EPERM;
+	{
+		unsigned int ticks, count;
+
+		/*
+		 * Generate the tone for the appropriate number of ticks.
+		 * If the time is zero, turn off sound ourselves.
+		 */
+		ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
+		count = ticks ? (arg & 0xffff) : 0;
+		if (count)
+			count = PIT_TICK_RATE / count;
+		kd_mksound(count, ticks);
+		break;
+	}
+
+	case KDGKBTYPE:
+		/*
+		 * this is naïve.
+		 */
+		return put_user(KB_101, (char __user *)arg);
+
+		/*
+		 * These cannot be implemented on any machine that implements
+		 * ioperm() in user level (such as Alpha PCs) or not at all.
+		 *
+		 * XXX: you should never use these, just call ioperm directly..
+		 */
+#ifdef CONFIG_X86
+	case KDADDIO:
+	case KDDELIO:
+		/*
+		 * KDADDIO and KDDELIO may be able to add ports beyond what
+		 * we reject here, but to be safe...
+		 *
+		 * These are locked internally via sys_ioperm
+		 */
+		if (arg < GPFIRST || arg > GPLAST)
+			return -EINVAL;
+
+		return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
+
+	case KDENABIO:
+	case KDDISABIO:
+		return ksys_ioperm(GPFIRST, GPNUM,
+				  (cmd == KDENABIO)) ? -ENXIO : 0;
+#endif
+
+	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
+
+	case KDKBDREP:
+	{
+		struct kbd_repeat kbrep;
+
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+
+		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
+			return -EFAULT;
+
+		ret = kbd_rate(&kbrep);
+		if (ret)
+			return ret;
+		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
+			return -EFAULT;
+		break;
+	}
+
+	case KDSETMODE:
+		if (!perm)
+			return -EPERM;
+
+		console_lock();
+		ret = vt_kdsetmode(vc, arg);
+		console_unlock();
+		return ret;
+
+	case KDGETMODE:
+		return put_user(vc->vc_mode, (int __user *)arg);
+
+	case KDMAPDISP:
+	case KDUNMAPDISP:
+		/*
+		 * these work like a combination of mmap and KDENABIO.
+		 * this could be easily finished.
+		 */
+		return -EINVAL;
+
+	case KDSKBMODE:
+		if (!perm)
+			return -EPERM;
+		ret = vt_do_kdskbmode(console, arg);
+		if (ret)
+			return ret;
+		tty_ldisc_flush(tty);
+		break;
+
+	case KDGKBMODE:
+		return put_user(vt_do_kdgkbmode(console), (int __user *)arg);
+
+	/* this could be folded into KDSKBMODE, but for compatibility
+	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
+	case KDSKBMETA:
+		return vt_do_kdskbmeta(console, arg);
+
+	case KDGKBMETA:
+		/* FIXME: should review whether this is worth locking */
+		return put_user(vt_do_kdgkbmeta(console), (int __user *)arg);
+
+	case KDGETKEYCODE:
+	case KDSETKEYCODE:
+		if(!capable(CAP_SYS_TTY_CONFIG))
+			perm = 0;
+		return vt_do_kbkeycode_ioctl(cmd, up, perm);
+
+	case KDGKBENT:
+	case KDSKBENT:
+		return vt_do_kdsk_ioctl(cmd, up, perm, console);
+
+	case KDGKBSENT:
+	case KDSKBSENT:
+		return vt_do_kdgkb_ioctl(cmd, up, perm);
+
+	/* Diacritical processing. Handled in keyboard.c as it has
+	   to operate on the keyboard locks and structures */
+	case KDGKBDIACR:
+	case KDGKBDIACRUC:
+	case KDSKBDIACR:
+	case KDSKBDIACRUC:
+		return vt_do_diacrit(cmd, up, perm);
+
+	/* the ioctls below read/set the flags usually shown in the leds */
+	/* don't use them - they will go away without warning */
+	case KDGKBLED:
+	case KDSKBLED:
+	case KDGETLED:
+	case KDSETLED:
+		return vt_do_kdskled(console, cmd, arg, perm);
+
+	/*
+	 * A process can indicate its willingness to accept signals
+	 * generated by pressing an appropriate key combination.
+	 * Thus, one can have a daemon that e.g. spawns a new console
+	 * upon a keypress and then changes to it.
+	 * See also the kbrequest field of inittab(5).
+	 */
+	case KDSIGACCEPT:
+		if (!perm || !capable(CAP_KILL))
+			return -EPERM;
+		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
+			return -EINVAL;
+
+		spin_lock_irq(&vt_spawn_con.lock);
+		put_pid(vt_spawn_con.pid);
+		vt_spawn_con.pid = get_pid(task_pid(current));
+		vt_spawn_con.sig = arg;
+		spin_unlock_irq(&vt_spawn_con.lock);
+		break;
+
+	case KDFONTOP: {
+		struct console_font_op op;
+
+		if (copy_from_user(&op, up, sizeof(op)))
+			return -EFAULT;
+		if (!perm && op.op != KD_FONT_OP_GET)
+			return -EPERM;
+		ret = con_font_op(vc, &op);
+		if (ret)
+			return ret;
+		if (copy_to_user(up, &op, sizeof(op)))
+			return -EFAULT;
+		break;
+	}
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
+		bool perm, struct vc_data *vc)
+{
+	struct unimapdesc tmp;
+
+	if (copy_from_user(&tmp, user_ud, sizeof tmp))
+		return -EFAULT;
+	switch (cmd) {
+	case PIO_UNIMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
+	case GIO_UNIMAP:
+		if (!perm && fg_console != vc->vc_num)
+			return -EPERM;
+		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
+				tmp.entries);
+	}
+	return 0;
+}
+
+static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,
+		bool perm)
+{
+	switch (cmd) {
+	case PIO_CMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_cmap(up);
+
+	case GIO_CMAP:
+		return con_get_cmap(up);
+
+	case PIO_SCRNMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_trans_old(up);
+
+	case GIO_SCRNMAP:
+		return con_get_trans_old(up);
+
+	case PIO_UNISCRNMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_trans_new(up);
+
+	case GIO_UNISCRNMAP:
+		return con_get_trans_new(up);
+
+	case PIO_UNIMAPCLR:
+		if (!perm)
+			return -EPERM;
+		con_clear_unimap(vc);
+		break;
+
+	case PIO_UNIMAP:
+	case GIO_UNIMAP:
+		return do_unimap_ioctl(cmd, up, perm, vc);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static int vt_reldisp(struct vc_data *vc, unsigned int swtch)
+{
+	int newvt, ret;
+
+	if (vc->vt_mode.mode != VT_PROCESS)
+		return -EINVAL;
+
+	/* Switched-to response */
+	if (vc->vt_newvt < 0) {
+		 /* If it's just an ACK, ignore it */
+		return swtch == VT_ACKACQ ? 0 : -EINVAL;
+	}
+
+	/* Switching-from response */
+	if (swtch == 0) {
+		/* Switch disallowed, so forget we were trying to do it. */
+		vc->vt_newvt = -1;
+		return 0;
+	}
+
+	/* The current vt has been released, so complete the switch. */
+	newvt = vc->vt_newvt;
+	vc->vt_newvt = -1;
+	ret = vc_allocate(newvt);
+	if (ret)
+		return ret;
+
+	/*
+	 * When we actually do the console switch, make sure we are atomic with
+	 * respect to other console switches..
+	 */
+	complete_change_console(vc_cons[newvt].d);
+
+	return 0;
+}
+
+static int vt_setactivate(struct vt_setactivate __user *sa)
+{
+	struct vt_setactivate vsa;
+	struct vc_data *nvc;
+	int ret;
+
+	if (copy_from_user(&vsa, sa, sizeof(vsa)))
+		return -EFAULT;
+	if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
+		return -ENXIO;
+
+	vsa.console--;
+	vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES);
+	console_lock();
+	ret = vc_allocate(vsa.console);
+	if (ret) {
+		console_unlock();
+		return ret;
+	}
+
+	/*
+	 * This is safe providing we don't drop the console sem between
+	 * vc_allocate and finishing referencing nvc.
+	 */
+	nvc = vc_cons[vsa.console].d;
+	nvc->vt_mode = vsa.mode;
+	nvc->vt_mode.frsig = 0;
+	put_pid(nvc->vt_pid);
+	nvc->vt_pid = get_pid(task_pid(current));
+	console_unlock();
+
+	/* Commence switch and lock */
+	/* Review set_console locks */
+	set_console(vsa.console);
+
+	return 0;
+}
+
+/* deallocate a single console, if possible (leave 0) */
+static int vt_disallocate(unsigned int vc_num)
+{
+	struct vc_data *vc = NULL;
+	int ret = 0;
+
+	console_lock();
+	if (vt_busy(vc_num))
+		ret = -EBUSY;
+	else if (vc_num)
+		vc = vc_deallocate(vc_num);
+	console_unlock();
+
+	if (vc && vc_num >= MIN_NR_CONSOLES)
+		tty_port_put(&vc->port);
+
+	return ret;
+}
+
+/* deallocate all unused consoles, but leave 0 */
+static void vt_disallocate_all(void)
+{
+	struct vc_data *vc[MAX_NR_CONSOLES];
+	int i;
+
+	console_lock();
+	for (i = 1; i < MAX_NR_CONSOLES; i++)
+		if (!vt_busy(i))
+			vc[i] = vc_deallocate(i);
+		else
+			vc[i] = NULL;
+	console_unlock();
+
+	for (i = 1; i < MAX_NR_CONSOLES; i++) {
+		if (vc[i] && i >= MIN_NR_CONSOLES)
+			tty_port_put(&vc[i]->port);
+	}
+}
+
+static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
+{
+	struct vt_consize v;
+	int i;
+
+	if (copy_from_user(&v, cs, sizeof(struct vt_consize)))
+		return -EFAULT;
+
+	/* FIXME: Should check the copies properly */
+	if (!v.v_vlin)
+		v.v_vlin = vc->vc_scan_lines;
+
+	if (v.v_clin) {
+		int rows = v.v_vlin / v.v_clin;
+		if (v.v_rows != rows) {
+			if (v.v_rows) /* Parameters don't add up */
+				return -EINVAL;
+			v.v_rows = rows;
+		}
+	}
+
+	if (v.v_vcol && v.v_ccol) {
+		int cols = v.v_vcol / v.v_ccol;
+		if (v.v_cols != cols) {
+			if (v.v_cols)
+				return -EINVAL;
+			v.v_cols = cols;
+		}
+	}
+
+	if (v.v_clin > 32)
+		return -EINVAL;
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		struct vc_data *vcp;
+
+		if (!vc_cons[i].d)
+			continue;
+		console_lock();
+		vcp = vc_cons[i].d;
+		if (vcp) {
+			int ret;
+			int save_scan_lines = vcp->vc_scan_lines;
+			int save_cell_height = vcp->vc_cell_height;
+
+			if (v.v_vlin)
+				vcp->vc_scan_lines = v.v_vlin;
+			if (v.v_clin)
+				vcp->vc_cell_height = v.v_clin;
+			vcp->vc_resize_user = 1;
+			ret = vc_resize(vcp, v.v_cols, v.v_rows);
+			if (ret) {
+				vcp->vc_scan_lines = save_scan_lines;
+				vcp->vc_cell_height = save_cell_height;
+				console_unlock();
+				return ret;
+			}
+		}
+		console_unlock();
+	}
+
+	return 0;
+}
+
+/*
+ * We handle the console-specific ioctl's here.  We allow the
+ * capability to modify any console, not just the fg_console.
+ */
+int vt_ioctl(struct tty_struct *tty,
+	     unsigned int cmd, unsigned long arg)
+{
+	struct vc_data *vc = tty->driver_data;
+	void __user *up = (void __user *)arg;
+	int i, perm;
+	int ret;
+
+	/*
+	 * To have permissions to do most of the vt ioctls, we either have
+	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
+	 */
+	perm = 0;
+	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
+		perm = 1;
+
+	ret = vt_k_ioctl(tty, cmd, arg, perm);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
+
+	ret = vt_io_ioctl(vc, cmd, up, perm);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
+
+	switch (cmd) {
+	case TIOCLINUX:
+		return tioclinux(tty, arg);
+	case VT_SETMODE:
+	{
+		struct vt_mode tmp;
+
+		if (!perm)
+			return -EPERM;
+		if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
+			return -EFAULT;
+		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
+			return -EINVAL;
+
+		console_lock();
+		vc->vt_mode = tmp;
+		/* the frsig is ignored, so we set it to 0 */
+		vc->vt_mode.frsig = 0;
+		put_pid(vc->vt_pid);
+		vc->vt_pid = get_pid(task_pid(current));
+		/* no switch is required -- saw@shade.msu.ru */
+		vc->vt_newvt = -1;
+		console_unlock();
+		break;
+	}
+
+	case VT_GETMODE:
+	{
+		struct vt_mode tmp;
+		int rc;
+
+		console_lock();
+		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
+		console_unlock();
+
+		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
+		if (rc)
+			return -EFAULT;
+		break;
+	}
+
+	/*
+	 * Returns global vt state. Note that VT 0 is always open, since
+	 * it's an alias for the current VT, and people can't use it here.
+	 * We cannot return state for more than 16 VTs, since v_state is short.
+	 */
+	case VT_GETSTATE:
+	{
+		struct vt_stat __user *vtstat = up;
+		unsigned short state, mask;
+
+		if (put_user(fg_console + 1, &vtstat->v_active))
+			return -EFAULT;
+
+		state = 1;	/* /dev/tty0 is always open */
+		console_lock(); /* required by vt_in_use() */
+		for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
+				++i, mask <<= 1)
+			if (vt_in_use(i))
+				state |= mask;
+		console_unlock();
+		return put_user(state, &vtstat->v_state);
+	}
+
+	/*
+	 * Returns the first available (non-opened) console.
+	 */
+	case VT_OPENQRY:
+		console_lock(); /* required by vt_in_use() */
+		for (i = 0; i < MAX_NR_CONSOLES; ++i)
+			if (!vt_in_use(i))
+				break;
+		console_unlock();
+		i = i < MAX_NR_CONSOLES ? (i+1) : -1;
+		return put_user(i, (int __user *)arg);
+
+	/*
+	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
+	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
+	 * to preserve sanity).
+	 */
+	case VT_ACTIVATE:
+		if (!perm)
+			return -EPERM;
+		if (arg == 0 || arg > MAX_NR_CONSOLES)
+			return -ENXIO;
+
+		arg--;
+		arg = array_index_nospec(arg, MAX_NR_CONSOLES);
+		console_lock();
+		ret = vc_allocate(arg);
+		console_unlock();
+		if (ret)
+			return ret;
+		set_console(arg);
+		break;
+
+	case VT_SETACTIVATE:
+		if (!perm)
+			return -EPERM;
+
+		return vt_setactivate(up);
+
+	/*
+	 * wait until the specified VT has been activated
+	 */
+	case VT_WAITACTIVE:
+		if (!perm)
+			return -EPERM;
+		if (arg == 0 || arg > MAX_NR_CONSOLES)
+			return -ENXIO;
+		return vt_waitactive(arg);
+
+	/*
+	 * If a vt is under process control, the kernel will not switch to it
+	 * immediately, but postpone the operation until the process calls this
+	 * ioctl, allowing the switch to complete.
+	 *
+	 * According to the X sources this is the behavior:
+	 *	0:	pending switch-from not OK
+	 *	1:	pending switch-from OK
+	 *	2:	completed switch-to OK
+	 */
+	case VT_RELDISP:
+		if (!perm)
+			return -EPERM;
+
+		console_lock();
+		ret = vt_reldisp(vc, arg);
+		console_unlock();
+
+		return ret;
+
+
+	 /*
+	  * Disallocate memory associated to VT (but leave VT1)
+	  */
+	 case VT_DISALLOCATE:
+		if (arg > MAX_NR_CONSOLES)
+			return -ENXIO;
+
+		if (arg == 0) {
+			vt_disallocate_all();
+			break;
+		}
+
+		arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES);
+		return vt_disallocate(arg);
+
+	case VT_RESIZE:
+	{
+		struct vt_sizes __user *vtsizes = up;
+		struct vc_data *vc;
+		ushort ll,cc;
+
+		if (!perm)
+			return -EPERM;
+		if (get_user(ll, &vtsizes->v_rows) ||
+		    get_user(cc, &vtsizes->v_cols))
+			return -EFAULT;
+
+		console_lock();
+		for (i = 0; i < MAX_NR_CONSOLES; i++) {
+			vc = vc_cons[i].d;
+
+			if (vc) {
+				vc->vc_resize_user = 1;
+				/* FIXME: review v tty lock */
+				vc_resize(vc_cons[i].d, cc, ll);
+			}
+		}
+		console_unlock();
+		break;
+	}
+
+	case VT_RESIZEX:
+		if (!perm)
+			return -EPERM;
+
+		return vt_resizex(vc, up);
+
+	case VT_LOCKSWITCH:
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+		vt_dont_switch = true;
+		break;
+	case VT_UNLOCKSWITCH:
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+		vt_dont_switch = false;
+		break;
+	case VT_GETHIFONTMASK:
+		return put_user(vc->vc_hi_font_mask,
+					(unsigned short __user *)arg);
+	case VT_WAITEVENT:
+		return vt_event_wait_ioctl((struct vt_event __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+void reset_vc(struct vc_data *vc)
+{
+	vc->vc_mode = KD_TEXT;
+	vt_reset_unicode(vc->vc_num);
+	vc->vt_mode.mode = VT_AUTO;
+	vc->vt_mode.waitv = 0;
+	vc->vt_mode.relsig = 0;
+	vc->vt_mode.acqsig = 0;
+	vc->vt_mode.frsig = 0;
+	put_pid(vc->vt_pid);
+	vc->vt_pid = NULL;
+	vc->vt_newvt = -1;
+	reset_palette(vc);
+}
+
+void vc_SAK(struct work_struct *work)
+{
+	struct vc *vc_con =
+		container_of(work, struct vc, SAK_work);
+	struct vc_data *vc;
+	struct tty_struct *tty;
+
+	console_lock();
+	vc = vc_con->d;
+	if (vc) {
+		/* FIXME: review tty ref counting */
+		tty = vc->port.tty;
+		/*
+		 * SAK should also work in all raw modes and reset
+		 * them properly.
+		 */
+		if (tty)
+			__do_SAK(tty);
+		reset_vc(vc);
+	}
+	console_unlock();
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_console_font_op {
+	compat_uint_t op;        /* operation code KD_FONT_OP_* */
+	compat_uint_t flags;     /* KD_FONT_FLAG_* */
+	compat_uint_t width, height;     /* font size */
+	compat_uint_t charcount;
+	compat_caddr_t data;    /* font data with height fixed to 32 */
+};
+
+static inline int
+compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
+			 int perm, struct console_font_op *op, struct vc_data *vc)
+{
+	int i;
+
+	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
+		return -EFAULT;
+	if (!perm && op->op != KD_FONT_OP_GET)
+		return -EPERM;
+	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
+	i = con_font_op(vc, op);
+	if (i)
+		return i;
+	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
+	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
+		return -EFAULT;
+	return 0;
+}
+
+struct compat_unimapdesc {
+	unsigned short entry_ct;
+	compat_caddr_t entries;
+};
+
+static inline int
+compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
+			 int perm, struct vc_data *vc)
+{
+	struct compat_unimapdesc tmp;
+	struct unipair __user *tmp_entries;
+
+	if (copy_from_user(&tmp, user_ud, sizeof tmp))
+		return -EFAULT;
+	tmp_entries = compat_ptr(tmp.entries);
+	switch (cmd) {
+	case PIO_UNIMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
+	case GIO_UNIMAP:
+		if (!perm && fg_console != vc->vc_num)
+			return -EPERM;
+		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
+	}
+	return 0;
+}
+
+long vt_compat_ioctl(struct tty_struct *tty,
+	     unsigned int cmd, unsigned long arg)
+{
+	struct vc_data *vc = tty->driver_data;
+	struct console_font_op op;	/* used in multiple places here */
+	void __user *up = compat_ptr(arg);
+	int perm;
+
+	/*
+	 * To have permissions to do most of the vt ioctls, we either have
+	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
+	 */
+	perm = 0;
+	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
+		perm = 1;
+
+	switch (cmd) {
+	/*
+	 * these need special handlers for incompatible data structures
+	 */
+
+	case KDFONTOP:
+		return compat_kdfontop_ioctl(up, perm, &op, vc);
+
+	case PIO_UNIMAP:
+	case GIO_UNIMAP:
+		return compat_unimap_ioctl(cmd, up, perm, vc);
+
+	/*
+	 * all these treat 'arg' as an integer
+	 */
+	case KIOCSOUND:
+	case KDMKTONE:
+#ifdef CONFIG_X86
+	case KDADDIO:
+	case KDDELIO:
+#endif
+	case KDSETMODE:
+	case KDMAPDISP:
+	case KDUNMAPDISP:
+	case KDSKBMODE:
+	case KDSKBMETA:
+	case KDSKBLED:
+	case KDSETLED:
+	case KDSIGACCEPT:
+	case VT_ACTIVATE:
+	case VT_WAITACTIVE:
+	case VT_RELDISP:
+	case VT_DISALLOCATE:
+	case VT_RESIZE:
+	case VT_RESIZEX:
+		return vt_ioctl(tty, cmd, arg);
+
+	/*
+	 * the rest has a compatible data structure behind arg,
+	 * but we have to convert it to a proper 64 bit pointer.
+	 */
+	default:
+		return vt_ioctl(tty, cmd, (unsigned long)up);
+	}
+}
+
+
+#endif /* CONFIG_COMPAT */
+
+
+/*
+ * Performs the back end of a vt switch. Called under the console
+ * semaphore.
+ */
+static void complete_change_console(struct vc_data *vc)
+{
+	unsigned char old_vc_mode;
+	int old = fg_console;
+
+	last_console = fg_console;
+
+	/*
+	 * If we're switching, we could be going from KD_GRAPHICS to
+	 * KD_TEXT mode or vice versa, which means we need to blank or
+	 * unblank the screen later.
+	 */
+	old_vc_mode = vc_cons[fg_console].d->vc_mode;
+	switch_screen(vc);
+
+	/*
+	 * This can't appear below a successful kill_pid().  If it did,
+	 * then the *blank_screen operation could occur while X, having
+	 * received acqsig, is waking up on another processor.  This
+	 * condition can lead to overlapping accesses to the VGA range
+	 * and the framebuffer (causing system lockups).
+	 *
+	 * To account for this we duplicate this code below only if the
+	 * controlling process is gone and we've called reset_vc.
+	 */
+	if (old_vc_mode != vc->vc_mode) {
+		if (vc->vc_mode == KD_TEXT)
+			do_unblank_screen(1);
+		else
+			do_blank_screen(1);
+	}
+
+	/*
+	 * If this new console is under process control, send it a signal
+	 * telling it that it has acquired. Also check if it has died and
+	 * clean up (similar to logic employed in change_console())
+	 */
+	if (vc->vt_mode.mode == VT_PROCESS) {
+		/*
+		 * Send the signal as privileged - kill_pid() will
+		 * tell us if the process has gone or something else
+		 * is awry
+		 */
+		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
+		/*
+		 * The controlling process has died, so we revert back to
+		 * normal operation. In this case, we'll also change back
+		 * to KD_TEXT mode. I'm not sure if this is strictly correct
+		 * but it saves the agony when the X server dies and the screen
+		 * remains blanked due to KD_GRAPHICS! It would be nice to do
+		 * this outside of VT_PROCESS but there is no single process
+		 * to account for and tracking tty count may be undesirable.
+		 */
+			reset_vc(vc);
+
+			if (old_vc_mode != vc->vc_mode) {
+				if (vc->vc_mode == KD_TEXT)
+					do_unblank_screen(1);
+				else
+					do_blank_screen(1);
+			}
+		}
+	}
+
+	/*
+	 * Wake anyone waiting for their VT to activate
+	 */
+	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
+	return;
+}
+
+/*
+ * Performs the front-end of a vt switch
+ */
+void change_console(struct vc_data *new_vc)
+{
+	struct vc_data *vc;
+
+	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
+		return;
+
+	/*
+	 * If this vt is in process mode, then we need to handshake with
+	 * that process before switching. Essentially, we store where that
+	 * vt wants to switch to and wait for it to tell us when it's done
+	 * (via VT_RELDISP ioctl).
+	 *
+	 * We also check to see if the controlling process still exists.
+	 * If it doesn't, we reset this vt to auto mode and continue.
+	 * This is a cheap way to track process control. The worst thing
+	 * that can happen is: we send a signal to a process, it dies, and
+	 * the switch gets "lost" waiting for a response; hopefully, the
+	 * user will try again, we'll detect the process is gone (unless
+	 * the user waits just the right amount of time :-) and revert the
+	 * vt to auto control.
+	 */
+	vc = vc_cons[fg_console].d;
+	if (vc->vt_mode.mode == VT_PROCESS) {
+		/*
+		 * Send the signal as privileged - kill_pid() will
+		 * tell us if the process has gone or something else
+		 * is awry.
+		 *
+		 * We need to set vt_newvt *before* sending the signal or we
+		 * have a race.
+		 */
+		vc->vt_newvt = new_vc->vc_num;
+		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
+			/*
+			 * It worked. Mark the vt to switch to and
+			 * return. The process needs to send us a
+			 * VT_RELDISP ioctl to complete the switch.
+			 */
+			return;
+		}
+
+		/*
+		 * The controlling process has died, so we revert back to
+		 * normal operation. In this case, we'll also change back
+		 * to KD_TEXT mode. I'm not sure if this is strictly correct
+		 * but it saves the agony when the X server dies and the screen
+		 * remains blanked due to KD_GRAPHICS! It would be nice to do
+		 * this outside of VT_PROCESS but there is no single process
+		 * to account for and tracking tty count may be undesirable.
+		 */
+		reset_vc(vc);
+
+		/*
+		 * Fall through to normal (VT_AUTO) handling of the switch...
+		 */
+	}
+
+	/*
+	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
+	 */
+	if (vc->vc_mode == KD_GRAPHICS)
+		return;
+
+	complete_change_console(new_vc);
+}
+
+/* Perform a kernel triggered VT switch for suspend/resume */
+
+static int disable_vt_switch;
+
+int vt_move_to_console(unsigned int vt, int alloc)
+{
+	int prev;
+
+	console_lock();
+	/* Graphics mode - up to X */
+	if (disable_vt_switch) {
+		console_unlock();
+		return 0;
+	}
+	prev = fg_console;
+
+	if (alloc && vc_allocate(vt)) {
+		/* we can't have a free VC for now. Too bad,
+		 * we don't want to mess the screen for now. */
+		console_unlock();
+		return -ENOSPC;
+	}
+
+	if (set_console(vt)) {
+		/*
+		 * We're unable to switch to the SUSPEND_CONSOLE.
+		 * Let the calling function know so it can decide
+		 * what to do.
+		 */
+		console_unlock();
+		return -EIO;
+	}
+	console_unlock();
+	if (vt_waitactive(vt + 1)) {
+		pr_debug("Suspend: Can't switch VCs.");
+		return -EINTR;
+	}
+	return prev;
+}
+
+/*
+ * Normally during a suspend, we allocate a new console and switch to it.
+ * When we resume, we switch back to the original console.  This switch
+ * can be slow, so on systems where the framebuffer can handle restoration
+ * of video registers anyways, there's little point in doing the console
+ * switch.  This function allows you to disable it by passing it '0'.
+ */
+void pm_set_vt_switch(int do_switch)
+{
+	console_lock();
+	disable_vt_switch = !do_switch;
+	console_unlock();
+}
+EXPORT_SYMBOL(pm_set_vt_switch);