Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 1349 insertions, 0 deletions

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
new file mode 100644
index 0000000000..3449f8790e
--- /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