Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1723 insertions, 0 deletions

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
new file mode 100644
index 000000000..f60db967b
--- /dev/null
+++ b/drivers/tty/amiserial.c
@@ -0,0 +1,1723 @@
+// 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 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
+ *
+ */
+
+#include <linux/delay.h>
+
+/* Set of debugging defines */
+
+#undef SERIAL_DEBUG_INTR
+#undef SERIAL_DEBUG_OPEN
+#undef SERIAL_DEBUG_FLOW
+#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+
+/* Sanity checks */
+
+#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
+#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
+ tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
+#else
+#define DBG_CNT(s)
+#endif
+
+/*
+ * End of serial driver configuration section.
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+static char *serial_version = "4.30";
+
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/circ_buf.h>
+#include <linux/console.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/init.h>
+#include <linux/bitops.h>
+#include <linux/platform_device.h>
+
+#include <asm/setup.h>
+
+
+#include <asm/irq.h>
+
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+
+struct serial_state {
+	struct tty_port		tport;
+	struct circ_buf		xmit;
+	struct async_icount	icount;
+
+	unsigned long		port;
+	int			baud_base;
+	int			xmit_fifo_size;
+	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 */
+};
+
+#define custom amiga_custom
+static char *serial_name = "Amiga-builtin serial driver";
+
+static struct tty_driver *serial_driver;
+
+/* number of characters left in xmit buffer before we ask for more */
+#define WAKEUP_CHARS 256
+
+static unsigned char current_ctl_bits;
+
+static void change_speed(struct tty_struct *tty, struct serial_state *info,
+		struct ktermios *old);
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
+
+
+static struct serial_state rs_table[1];
+
+#define NR_PORTS ARRAY_SIZE(rs_table)
+
+#include <linux/uaccess.h>
+
+#define serial_isroot()	(capable(CAP_SYS_ADMIN))
+
+/* 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->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 */
+		custom.intena = IF_TBE;
+		mb();
+		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;
+		custom.intena = IF_SETCLR | IF_TBE;
+		mb();
+		/* set a pending Tx Interrupt, transmitter should restart now */
+		custom.intreq = IF_SETCLR | IF_TBE;
+		mb();
+	}
+	local_irq_restore(flags);
+}
+
+/*
+ * ----------------------------------------------------------------------
+ *
+ * Here starts the interrupt handling routines.  All of the following
+ * subroutines are declared as inline and are folded into
+ * rs_interrupt().  They were separated out for readability's sake.
+ *
+ * Note: rs_interrupt() is a "fast" interrupt, which means that it
+ * runs with interrupts turned off.  People who may want to modify
+ * rs_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:
+ * 
+ * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
+ *
+ * and look at the resulting assemble code in serial.s.
+ *
+ * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
+ * -----------------------------------------------------------------------
+ */
+
+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 = custom.serdatr;
+	mb();
+	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)
+{
+	custom.intreq = IF_TBE;
+	mb();
+	if (info->x_char) {
+	        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->stopped
+	    || info->tport.tty->hw_stopped) {
+		info->IER &= ~UART_IER_THRI;
+	        custom.intena = IF_TBE;
+		mb();
+		return;
+	}
+
+	custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
+	mb();
+	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
+	info->icount.tx++;
+
+	if (CIRC_CNT(info->xmit.head,
+		     info->xmit.tail,
+		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
+		tty_wakeup(info->tport.tty);
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("THRE...");
+#endif
+	if (info->xmit.head == info->xmit.tail) {
+	        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 = 0;
+				info->IER |= UART_IER_THRI;
+				custom.intena = IF_SETCLR | IF_TBE;
+				mb();
+				/* set a pending Tx Interrupt, transmitter should restart now */
+				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 = 1;
+				info->IER &= ~UART_IER_THRI;
+				/* disable Tx interrupt and remove any pending interrupts */
+				custom.intena = IF_TBE;
+				mb();
+				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 (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 */
+
+	custom.intreq = IF_RBF;
+	mb();
+
+	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
+	if (retval) {
+	  if (serial_isroot()) {
+	      set_bit(TTY_IO_ERROR, &tty->flags);
+	    retval = 0;
+	  }
+	  goto errout;
+	}
+
+	/* enable both Rx and Tx interrupts */
+	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, 1);
+	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;
+	struct serial_state *state;
+
+	if (!tty_port_initialized(&info->tport))
+		return;
+
+	state = info;
+
+#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);
+
+	if (info->xmit.buf) {
+		free_page((unsigned long) info->xmit.buf);
+		info->xmit.buf = NULL;
+	}
+
+	info->IER = 0;
+	custom.intena = IF_RBF | IF_TBE;
+	mb();
+
+	/* disable break condition */
+	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, 0);
+	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,
+			 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;
+#ifdef CMSPAR
+	if (cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+#endif
+
+	/* 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 = ((info->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);
+
+	custom.serper = serper;
+	mb();
+	}
+
+	local_irq_restore(flags);
+}
+
+static int rs_put_char(struct tty_struct *tty, unsigned char 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,
+		       SERIAL_XMIT_SIZE) == 0) {
+		local_irq_restore(flags);
+		return 0;
+	}
+
+	info->xmit.buf[info->xmit.head++] = ch;
+	info->xmit.head &= SERIAL_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->stopped
+	    || tty->hw_stopped
+	    || !info->xmit.buf)
+		return;
+
+	local_irq_save(flags);
+	info->IER |= UART_IER_THRI;
+	custom.intena = IF_SETCLR | IF_TBE;
+	mb();
+	/* set a pending Tx Interrupt, transmitter should restart now */
+	custom.intreq = IF_SETCLR | IF_TBE;
+	mb();
+	local_irq_restore(flags);
+}
+
+static int rs_write(struct tty_struct * tty, const unsigned char *buf, int 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,
+				      SERIAL_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) &
+				   (SERIAL_XMIT_SIZE-1));
+		buf += c;
+		count -= c;
+		ret += c;
+	}
+	local_irq_restore(flags);
+
+	if (info->xmit.head != info->xmit.tail
+	    && !tty->stopped
+	    && !tty->hw_stopped
+	    && !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		local_irq_disable();
+		custom.intena = IF_SETCLR | IF_TBE;
+		mb();
+		/* set a pending Tx Interrupt, transmitter should restart now */
+		custom.intreq = IF_SETCLR | IF_TBE;
+		mb();
+		local_irq_restore(flags);
+	}
+	return ret;
+}
+
+static int rs_write_room(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static 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, SERIAL_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(!(custom.intenar & IF_TBE)) {
+		    custom.intena = IF_SETCLR | IF_TBE;
+		    mb();
+		    /* set a pending Tx Interrupt, transmitter should restart now */
+		    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;
+
+	tty_lock(tty);
+	ss->line = tty->index;
+	ss->port = state->port;
+	ss->flags = state->tport.flags;
+	ss->xmit_fifo_size = state->xmit_fifo_size;
+	ss->baud_base = state->baud_base;
+	ss->close_delay = state->tport.close_delay;
+	ss->closing_wait = state->tport.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;
+
+	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 != state->xmit_fifo_size) {
+		tty_unlock(tty);
+		return -EINVAL;
+	}
+  
+	if (!serial_isroot()) {
+		if ((ss->baud_base != state->baud_base) ||
+		    (ss->close_delay != port->close_delay) ||
+		    (ss->closing_wait != port->closing_wait) ||
+		    (ss->xmit_fifo_size != state->xmit_fifo_size) ||
+		    ((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 = ss->close_delay * HZ/100;
+	port->closing_wait = ss->closing_wait * HZ/100;
+	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+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 = 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)
+	  custom.adkcon = AC_SETCLR | AC_UARTBRK;
+	else
+	  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, 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 = 0;
+		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 */
+	        custom.intena = IF_RBF;
+		mb();
+		/* clear any pending receive interrupt */
+		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;
+
+	if (info->xmit_fifo_size == 0)
+		return; /* Just in case.... */
+
+	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) / info->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 = 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, 0);
+	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 serial_state *info = rs_table + tty->index;
+	struct tty_port *port = &info->tport;
+	int retval;
+
+	port->count++;
+	port->tty = tty;
+	tty->driver_data = info;
+	tty->port = port;
+
+	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+	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:%s\n", serial_version);
+	line_info(m, 0, &rs_table[0]);
+	return 0;
+}
+
+/*
+ * ---------------------------------------------------------------------
+ * rs_init() and friends
+ *
+ * rs_init() is called at boot-time to initialize the serial driver.
+ * ---------------------------------------------------------------------
+ */
+
+/*
+ * This routine prints out the appropriate serial driver version
+ * number, and identifies which options were configured into this
+ * driver.
+ */
+static void show_serial_version(void)
+{
+ 	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
+}
+
+
+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 int amiga_carrier_raised(struct tty_port *port)
+{
+	return !(ciab.pra & SER_DCD);
+}
+
+static void amiga_dtr_rts(struct tty_port *port, int raise)
+{
+	struct serial_state *info = container_of(port, struct serial_state,
+			tport);
+	unsigned long flags;
+
+	if (raise)
+		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)
+{
+	unsigned long flags;
+	struct serial_state * state;
+	int error;
+
+	serial_driver = alloc_tty_driver(NR_PORTS);
+	if (!serial_driver)
+		return -ENOMEM;
+
+	show_serial_version();
+
+	/* Initialize the tty_driver structure */
+
+	serial_driver->driver_name = "amiserial";
+	serial_driver->name = "ttyS";
+	serial_driver->major = TTY_MAJOR;
+	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->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(serial_driver, &serial_ops);
+
+	state = rs_table;
+	state->port = (int)&custom.serdatr; /* Just to give it a value */
+	state->custom_divisor = 0;
+	state->icount.cts = state->icount.dsr = 
+	  state->icount.rng = state->icount.dcd = 0;
+	state->icount.rx = state->icount.tx = 0;
+	state->icount.frame = state->icount.parity = 0;
+	state->icount.overrun = state->icount.brk = 0;
+	tty_port_init(&state->tport);
+	state->tport.ops = &amiga_port_ops;
+	tty_port_link_device(&state->tport, serial_driver, 0);
+
+	error = tty_register_driver(serial_driver);
+	if (error)
+		goto fail_put_tty_driver;
+
+	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
+
+	/* Hardware set up */
+
+	state->baud_base = amiga_colorclock;
+	state->xmit_fifo_size = 1;
+
+	/* 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 */
+	custom.intena = IF_RBF | IF_TBE;
+	mb();
+
+	/* clear any pending interrupt */
+	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);
+
+	return 0;
+
+fail_free_irq:
+	free_irq(IRQ_AMIGA_TBE, state);
+fail_unregister:
+	tty_unregister_driver(serial_driver);
+fail_put_tty_driver:
+	tty_port_destroy(&state->tport);
+	put_tty_driver(serial_driver);
+	return error;
+}
+
+static int __exit amiga_serial_remove(struct platform_device *pdev)
+{
+	int error;
+	struct serial_state *state = platform_get_drvdata(pdev);
+
+	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
+	error = tty_unregister_driver(serial_driver);
+	if (error)
+		printk("SERIAL: failed to unregister serial driver (%d)\n",
+		       error);
+	put_tty_driver(serial_driver);
+	tty_port_destroy(&state->tport);
+
+	free_irq(IRQ_AMIGA_TBE, state);
+	free_irq(IRQ_AMIGA_RBF, state);
+
+	return error;
+}
+
+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)
+{
+	custom.serdat = (unsigned char)c | 0x100;
+	while (!(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 = custom.intenar;
+
+	custom.intena = IF_TBE;
+
+	while (count--) {
+		if (*s == '\n')
+			amiga_serial_putc('\r');
+		amiga_serial_putc(*s++);
+	}
+
+	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");