tty: move drivers/serial/ to drivers/tty/serial/

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3377 insertions, 0 deletions

diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
new file mode 100644
index 000000000000..b25e6e490530
--- /dev/null
+++ b/drivers/tty/serial/8250.c
@@ -0,0 +1,3377 @@
+/*
+ *  linux/drivers/char/8250.c
+ *
+ *  Driver for 8250/16550-type serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright (C) 2001 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * A note about mapbase / membase
+ *
+ *  mapbase is the physical address of the IO port.
+ *  membase is an 'ioremapped' cookie.
+ */
+
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#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/tty.h>
+#include <linux/ratelimit.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_reg.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/nmi.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include "8250.h"
+
+#ifdef CONFIG_SPARC
+#include "suncore.h"
+#endif
+
+/*
+ * 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 int serial_index(struct uart_port *port)
+{
+	return (serial8250_reg.minor - 64) + port->line;
+}
+
+static unsigned int skip_txen_test; /* force skip of txen test at init time */
+
+/*
+ * Debugging.
+ */
+#if 0
+#define DEBUG_AUTOCONF(fmt...)	printk(fmt)
+#else
+#define DEBUG_AUTOCONF(fmt...)	do { } while (0)
+#endif
+
+#if 0
+#define DEBUG_INTR(fmt...)	printk(fmt)
+#else
+#define DEBUG_INTR(fmt...)	do { } while (0)
+#endif
+
+#define PASS_LIMIT	256
+
+#define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)
+
+
+/*
+ * We default to IRQ0 for the "no irq" hack.   Some
+ * machine types want others as well - they're free
+ * to redefine this in their header file.
+ */
+#define is_real_interrupt(irq)	((irq) != 0)
+
+#ifdef CONFIG_SERIAL_8250_DETECT_IRQ
+#define CONFIG_SERIAL_DETECT_IRQ 1
+#endif
+#ifdef CONFIG_SERIAL_8250_MANY_PORTS
+#define CONFIG_SERIAL_MANY_PORTS 1
+#endif
+
+/*
+ * HUB6 is always on.  This will be removed once the header
+ * files have been cleaned.
+ */
+#define CONFIG_HUB6 1
+
+#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 uart_8250_port {
+	struct uart_port	port;
+	struct timer_list	timer;		/* "no irq" timer */
+	struct list_head	list;		/* ports on this IRQ */
+	unsigned short		capabilities;	/* port capabilities */
+	unsigned short		bugs;		/* port bugs */
+	unsigned int		tx_loadsz;	/* transmit fifo load size */
+	unsigned char		acr;
+	unsigned char		ier;
+	unsigned char		lcr;
+	unsigned char		mcr;
+	unsigned char		mcr_mask;	/* mask of user bits */
+	unsigned char		mcr_force;	/* mask of forced bits */
+	unsigned char		cur_iotype;	/* Running I/O type */
+
+	/*
+	 * 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.
+	 */
+#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
+	unsigned char		lsr_saved_flags;
+#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
+	unsigned char		msr_saved_flags;
+};
+
+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 */
+
+/*
+ * 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,
+		.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,
+		.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,
+		.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_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | 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,
+		.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,
+	},
+	[PORT_RM9000] = {
+		.name		= "RM9000",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO,
+	},
+	[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,
+	},
+};
+
+#if defined(CONFIG_MIPS_ALCHEMY)
+
+/* Au1x00 UART hardware has a weird register layout */
+static const u8 au_io_in_map[] = {
+	[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[] = {
+	[UART_TX]  = 1,
+	[UART_IER] = 2,
+	[UART_FCR] = 4,
+	[UART_LCR] = 5,
+	[UART_MCR] = 6,
+};
+
+/* sane hardware needs no mapping */
+static inline int map_8250_in_reg(struct uart_port *p, int offset)
+{
+	if (p->iotype != UPIO_AU)
+		return offset;
+	return au_io_in_map[offset];
+}
+
+static inline int map_8250_out_reg(struct uart_port *p, int offset)
+{
+	if (p->iotype != UPIO_AU)
+		return offset;
+	return au_io_out_map[offset];
+}
+
+#elif defined(CONFIG_SERIAL_8250_RM9K)
+
+static const u8
+	regmap_in[8] = {
+		[UART_RX]	= 0x00,
+		[UART_IER]	= 0x0c,
+		[UART_IIR]	= 0x14,
+		[UART_LCR]	= 0x1c,
+		[UART_MCR]	= 0x20,
+		[UART_LSR]	= 0x24,
+		[UART_MSR]	= 0x28,
+		[UART_SCR]	= 0x2c
+	},
+	regmap_out[8] = {
+		[UART_TX] 	= 0x04,
+		[UART_IER]	= 0x0c,
+		[UART_FCR]	= 0x18,
+		[UART_LCR]	= 0x1c,
+		[UART_MCR]	= 0x20,
+		[UART_LSR]	= 0x24,
+		[UART_MSR]	= 0x28,
+		[UART_SCR]	= 0x2c
+	};
+
+static inline int map_8250_in_reg(struct uart_port *p, int offset)
+{
+	if (p->iotype != UPIO_RM9000)
+		return offset;
+	return regmap_in[offset];
+}
+
+static inline int map_8250_out_reg(struct uart_port *p, int offset)
+{
+	if (p->iotype != UPIO_RM9000)
+		return offset;
+	return regmap_out[offset];
+}
+
+#else
+
+/* sane hardware needs no mapping */
+#define map_8250_in_reg(up, offset) (offset)
+#define map_8250_out_reg(up, offset) (offset)
+
+#endif
+
+static unsigned int hub6_serial_in(struct uart_port *p, int offset)
+{
+	offset = map_8250_in_reg(p, 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 = map_8250_out_reg(p, 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 = map_8250_in_reg(p, offset) << p->regshift;
+	return readb(p->membase + offset);
+}
+
+static void mem_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	writeb(value, p->membase + offset);
+}
+
+static void mem32_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	writel(value, p->membase + offset);
+}
+
+static unsigned int mem32_serial_in(struct uart_port *p, int offset)
+{
+	offset = map_8250_in_reg(p, offset) << p->regshift;
+	return readl(p->membase + offset);
+}
+
+static unsigned int au_serial_in(struct uart_port *p, int offset)
+{
+	offset = map_8250_in_reg(p, offset) << p->regshift;
+	return __raw_readl(p->membase + offset);
+}
+
+static void au_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	__raw_writel(value, p->membase + offset);
+}
+
+static unsigned int tsi_serial_in(struct uart_port *p, int offset)
+{
+	unsigned int tmp;
+	offset = map_8250_in_reg(p, offset) << p->regshift;
+	if (offset == UART_IIR) {
+		tmp = readl(p->membase + (UART_IIR & ~3));
+		return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
+	} else
+		return readb(p->membase + offset);
+}
+
+static void tsi_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	if (!((offset == UART_IER) && (value & UART_IER_UUE)))
+		writeb(value, p->membase + offset);
+}
+
+/* Save the LCR value so it can be re-written when a Busy Detect IRQ occurs. */
+static inline void dwapb_save_out_value(struct uart_port *p, int offset,
+					int value)
+{
+	struct uart_8250_port *up =
+		container_of(p, struct uart_8250_port, port);
+
+	if (offset == UART_LCR)
+		up->lcr = value;
+}
+
+/* Read the IER to ensure any interrupt is cleared before returning from ISR. */
+static inline void dwapb_check_clear_ier(struct uart_port *p, int offset)
+{
+	if (offset == UART_TX || offset == UART_IER)
+		p->serial_in(p, UART_IER);
+}
+
+static void dwapb_serial_out(struct uart_port *p, int offset, int value)
+{
+	int save_offset = offset;
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	dwapb_save_out_value(p, save_offset, value);
+	writeb(value, p->membase + offset);
+	dwapb_check_clear_ier(p, save_offset);
+}
+
+static void dwapb32_serial_out(struct uart_port *p, int offset, int value)
+{
+	int save_offset = offset;
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	dwapb_save_out_value(p, save_offset, value);
+	writel(value, p->membase + offset);
+	dwapb_check_clear_ier(p, save_offset);
+}
+
+static unsigned int io_serial_in(struct uart_port *p, int offset)
+{
+	offset = map_8250_in_reg(p, offset) << p->regshift;
+	return inb(p->iobase + offset);
+}
+
+static void io_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = map_8250_out_reg(p, offset) << p->regshift;
+	outb(value, p->iobase + offset);
+}
+
+static void set_io_from_upio(struct uart_port *p)
+{
+	struct uart_8250_port *up =
+		container_of(p, struct uart_8250_port, port);
+	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_RM9000:
+	case UPIO_MEM32:
+		p->serial_in = mem32_serial_in;
+		p->serial_out = mem32_serial_out;
+		break;
+
+	case UPIO_AU:
+		p->serial_in = au_serial_in;
+		p->serial_out = au_serial_out;
+		break;
+
+	case UPIO_TSI:
+		p->serial_in = tsi_serial_in;
+		p->serial_out = tsi_serial_out;
+		break;
+
+	case UPIO_DWAPB:
+		p->serial_in = mem_serial_in;
+		p->serial_out = dwapb_serial_out;
+		break;
+
+	case UPIO_DWAPB32:
+		p->serial_in = mem32_serial_in;
+		p->serial_out = dwapb32_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;
+}
+
+static void
+serial_out_sync(struct uart_8250_port *up, int offset, int value)
+{
+	struct uart_port *p = &up->port;
+	switch (p->iotype) {
+	case UPIO_MEM:
+	case UPIO_MEM32:
+	case UPIO_AU:
+	case UPIO_DWAPB:
+	case UPIO_DWAPB32:
+		p->serial_out(p, offset, value);
+		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
+		break;
+	default:
+		p->serial_out(p, offset, value);
+	}
+}
+
+#define serial_in(up, offset)		\
+	(up->port.serial_in(&(up)->port, (offset)))
+#define serial_out(up, offset, value)	\
+	(up->port.serial_out(&(up)->port, (offset), (value)))
+/*
+ * 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)
+
+/* Uart divisor latch read */
+static inline int _serial_dl_read(struct uart_8250_port *up)
+{
+	return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
+}
+
+/* Uart divisor latch write */
+static inline void _serial_dl_write(struct uart_8250_port *up, int value)
+{
+	serial_outp(up, UART_DLL, value & 0xff);
+	serial_outp(up, UART_DLM, value >> 8 & 0xff);
+}
+
+#if defined(CONFIG_MIPS_ALCHEMY)
+/* Au1x00 haven't got a standard divisor latch */
+static int serial_dl_read(struct uart_8250_port *up)
+{
+	if (up->port.iotype == UPIO_AU)
+		return __raw_readl(up->port.membase + 0x28);
+	else
+		return _serial_dl_read(up);
+}
+
+static void serial_dl_write(struct uart_8250_port *up, int value)
+{
+	if (up->port.iotype == UPIO_AU)
+		__raw_writel(value, up->port.membase + 0x28);
+	else
+		_serial_dl_write(up, value);
+}
+#elif defined(CONFIG_SERIAL_8250_RM9K)
+static int serial_dl_read(struct uart_8250_port *up)
+{
+	return	(up->port.iotype == UPIO_RM9000) ?
+		(((__raw_readl(up->port.membase + 0x10) << 8) |
+		(__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
+		_serial_dl_read(up);
+}
+
+static void serial_dl_write(struct uart_8250_port *up, int value)
+{
+	if (up->port.iotype == UPIO_RM9000) {
+		__raw_writel(value, up->port.membase + 0x08);
+		__raw_writel(value >> 8, up->port.membase + 0x10);
+	} else {
+		_serial_dl_write(up, value);
+	}
+}
+#else
+#define serial_dl_read(up) _serial_dl_read(up)
+#define serial_dl_write(up, value) _serial_dl_write(up, value)
+#endif
+
+/*
+ * 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 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;
+}
+
+/*
+ * FIFO support.
+ */
+static void serial8250_clear_fifos(struct uart_8250_port *p)
+{
+	if (p->capabilities & UART_CAP_FIFO) {
+		serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
+			       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+		serial_outp(p, UART_FCR, 0);
+	}
+}
+
+/*
+ * 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)
+{
+	if (p->capabilities & UART_CAP_SLEEP) {
+		if (p->capabilities & UART_CAP_EFR) {
+			serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
+			serial_outp(p, UART_EFR, UART_EFR_ECB);
+			serial_outp(p, UART_LCR, 0);
+		}
+		serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
+		if (p->capabilities & UART_CAP_EFR) {
+			serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
+			serial_outp(p, UART_EFR, 0);
+			serial_outp(p, UART_LCR, 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_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_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_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_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_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 */
+
+/*
+ * 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;
+	unsigned short old_dl;
+	int count;
+
+	old_lcr = serial_inp(up, UART_LCR);
+	serial_outp(up, UART_LCR, 0);
+	old_fcr = serial_inp(up, UART_FCR);
+	old_mcr = serial_inp(up, UART_MCR);
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+		    UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial_outp(up, UART_MCR, UART_MCR_LOOP);
+	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	old_dl = serial_dl_read(up);
+	serial_dl_write(up, 0x0001);
+	serial_outp(up, UART_LCR, 0x03);
+	for (count = 0; count < 256; count++)
+		serial_outp(up, UART_TX, count);
+	mdelay(20);/* FIXME - schedule_timeout */
+	for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
+	     (count < 256); count++)
+		serial_inp(up, UART_RX);
+	serial_outp(up, UART_FCR, old_fcr);
+	serial_outp(up, UART_MCR, old_mcr);
+	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_dl_write(up, old_dl);
+	serial_outp(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_dll, old_dlm, old_lcr;
+	unsigned int id;
+
+	old_lcr = serial_inp(p, UART_LCR);
+	serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_A);
+
+	old_dll = serial_inp(p, UART_DLL);
+	old_dlm = serial_inp(p, UART_DLM);
+
+	serial_outp(p, UART_DLL, 0);
+	serial_outp(p, UART_DLM, 0);
+
+	id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
+
+	serial_outp(p, UART_DLL, old_dll);
+	serial_outp(p, UART_DLM, old_dlm);
+	serial_outp(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_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_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;
+
+	up->port.type = PORT_16550A;
+	up->capabilities |= UART_CAP_FIFO;
+
+	/*
+	 * Check for presence of the EFR when DLAB is set.
+	 * Only ST16C650V1 UARTs pass this test.
+	 */
+	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	if (serial_in(up, UART_EFR) == 0) {
+		serial_outp(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 {
+			DEBUG_AUTOCONF("Motorola 8xxx DUART ");
+		}
+		serial_outp(up, UART_EFR, 0);
+		return;
+	}
+
+	/*
+	 * Maybe it requires 0xbf to be written to the LCR.
+	 * (other ST16C650V2 UARTs, TI16C752A, etc)
+	 */
+	serial_outp(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_outp(up, UART_LCR, 0);
+	status1 = serial_in(up, UART_MCR);
+	serial_outp(up, UART_LCR, 0xE0);
+	status2 = serial_in(up, 0x02); /* EXCR1 */
+
+	if (!((status2 ^ status1) & UART_MCR_LOOP)) {
+		serial_outp(up, UART_LCR, 0);
+		serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
+		serial_outp(up, UART_LCR, 0xE0);
+		status2 = serial_in(up, 0x02); /* EXCR1 */
+		serial_outp(up, UART_LCR, 0);
+		serial_outp(up, UART_MCR, status1);
+
+		if ((status2 ^ status1) & UART_MCR_LOOP) {
+			unsigned short quot;
+
+			serial_outp(up, UART_LCR, 0xE0);
+
+			quot = serial_dl_read(up);
+			quot <<= 3;
+
+			status1 = serial_in(up, 0x04); /* EXCR2 */
+			status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
+			status1 |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
+			serial_outp(up, 0x04, status1);
+
+			serial_dl_write(up, quot);
+
+			serial_outp(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_outp(up, UART_LCR, 0);
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+	status1 = serial_in(up, UART_IIR) >> 5;
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+	status2 = serial_in(up, UART_IIR) >> 5;
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_outp(up, UART_LCR, 0);
+
+	DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
+
+	if (status1 == 6 && status2 == 7) {
+		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 start.
+	 */
+	iersave = serial_in(up, UART_IER);
+	serial_outp(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_outp(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;
+			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_outp(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 int probeflags)
+{
+	unsigned char status1, scratch, scratch2, scratch3;
+	unsigned char save_lcr, save_mcr;
+	unsigned long flags;
+
+	if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
+		return;
+
+	DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
+		       serial_index(&up->port), up->port.iobase, up->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.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->capabilities = 0;
+	up->bugs = 0;
+
+	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.
+		 *
+		 * Note: this is safe as long as MCR bit 4 is clear
+		 * and the device is in "PC" mode.
+		 */
+		scratch = serial_inp(up, UART_IER);
+		serial_outp(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_inp(up, UART_IER) & 0x0f;
+		serial_outp(up, UART_IER, 0x0F);
+#ifdef __i386__
+		outb(0, 0x080);
+#endif
+		scratch3 = serial_inp(up, UART_IER) & 0x0f;
+		serial_outp(up, UART_IER, scratch);
+		if (scratch2 != 0 || scratch3 != 0x0F) {
+			/*
+			 * We failed; there's nothing here
+			 */
+			DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
+				       scratch2, scratch3);
+			goto out;
+		}
+	}
+
+	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) {
+			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_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_outp(up, UART_EFR, 0);
+	serial_outp(up, UART_LCR, 0);
+
+	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	scratch = serial_in(up, UART_IIR) >> 6;
+
+	DEBUG_AUTOCONF("iir=%d ", scratch);
+
+	switch (scratch) {
+	case 0:
+		autoconfig_8250(up);
+		break;
+	case 1:
+		up->port.type = PORT_UNKNOWN;
+		break;
+	case 2:
+		up->port.type = PORT_16550;
+		break;
+	case 3:
+		autoconfig_16550a(up);
+		break;
+	}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * Only probe for RSA ports if we got the region.
+	 */
+	if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
+		int i;
+
+		for (i = 0 ; i < probe_rsa_count; ++i) {
+			if (probe_rsa[i] == up->port.iobase &&
+			    __enable_rsa(up)) {
+				up->port.type = PORT_RSA;
+				break;
+			}
+		}
+	}
+#endif
+
+	serial_outp(up, UART_LCR, save_lcr);
+
+	if (up->capabilities != uart_config[up->port.type].flags) {
+		printk(KERN_WARNING
+		       "ttyS%d: detected caps %08x should be %08x\n",
+		       serial_index(&up->port), up->capabilities,
+		       uart_config[up->port.type].flags);
+	}
+
+	up->port.fifosize = uart_config[up->port.type].fifo_size;
+	up->capabilities = uart_config[up->port.type].flags;
+	up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
+
+	if (up->port.type == PORT_UNKNOWN)
+		goto out;
+
+	/*
+	 * 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);
+	serial8250_clear_fifos(up);
+	serial_in(up, UART_RX);
+	if (up->capabilities & UART_CAP_UUE)
+		serial_outp(up, UART_IER, UART_IER_UUE);
+	else
+		serial_outp(up, UART_IER, 0);
+
+ out:
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
+}
+
+static void autoconfig_irq(struct uart_8250_port *up)
+{
+	unsigned char save_mcr, save_ier;
+	unsigned char save_ICP = 0;
+	unsigned int ICP = 0;
+	unsigned long irqs;
+	int irq;
+
+	if (up->port.flags & UPF_FOURPORT) {
+		ICP = (up->port.iobase & 0xfe0) | 0x1f;
+		save_ICP = inb_p(ICP);
+		outb_p(0x80, ICP);
+		(void) inb_p(ICP);
+	}
+
+	/* forget possible initially masked and pending IRQ */
+	probe_irq_off(probe_irq_on());
+	save_mcr = serial_inp(up, UART_MCR);
+	save_ier = serial_inp(up, UART_IER);
+	serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
+
+	irqs = probe_irq_on();
+	serial_outp(up, UART_MCR, 0);
+	udelay(10);
+	if (up->port.flags & UPF_FOURPORT) {
+		serial_outp(up, UART_MCR,
+			    UART_MCR_DTR | UART_MCR_RTS);
+	} else {
+		serial_outp(up, UART_MCR,
+			    UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
+	}
+	serial_outp(up, UART_IER, 0x0f);	/* enable all intrs */
+	(void)serial_inp(up, UART_LSR);
+	(void)serial_inp(up, UART_RX);
+	(void)serial_inp(up, UART_IIR);
+	(void)serial_inp(up, UART_MSR);
+	serial_outp(up, UART_TX, 0xFF);
+	udelay(20);
+	irq = probe_irq_off(irqs);
+
+	serial_outp(up, UART_MCR, save_mcr);
+	serial_outp(up, UART_IER, save_ier);
+
+	if (up->port.flags & UPF_FOURPORT)
+		outb_p(save_ICP, ICP);
+
+	up->port.irq = (irq > 0) ? irq : 0;
+}
+
+static inline void __stop_tx(struct uart_8250_port *p)
+{
+	if (p->ier & UART_IER_THRI) {
+		p->ier &= ~UART_IER_THRI;
+		serial_out(p, UART_IER, p->ier);
+	}
+}
+
+static void serial8250_stop_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_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 transmit_chars(struct uart_8250_port *up);
+
+static void serial8250_start_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+
+		if (up->bugs & UART_BUG_TXEN) {
+			unsigned char lsr;
+			lsr = serial_in(up, UART_LSR);
+			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+			if ((up->port.type == PORT_RM9000) ?
+				(lsr & UART_LSR_THRE) :
+				(lsr & UART_LSR_TEMT))
+				transmit_chars(up);
+		}
+	}
+
+	/*
+	 * 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 serial8250_stop_rx(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	up->ier &= ~UART_IER_RLSI;
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void serial8250_enable_ms(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	/* no MSR capabilities */
+	if (up->bugs & UART_BUG_NOMSR)
+		return;
+
+	up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void
+receive_chars(struct uart_8250_port *up, unsigned int *status)
+{
+	struct tty_struct *tty = up->port.state->port.tty;
+	unsigned char ch, lsr = *status;
+	int max_count = 256;
+	char flag;
+
+	do {
+		if (likely(lsr & UART_LSR_DR))
+			ch = serial_inp(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;
+
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		lsr |= up->lsr_saved_flags;
+		up->lsr_saved_flags = 0;
+
+		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
+			/*
+			 * For statistics only
+			 */
+			if (lsr & UART_LSR_BI) {
+				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))
+					goto ignore_char;
+			} else if (lsr & UART_LSR_PE)
+				up->port.icount.parity++;
+			else if (lsr & UART_LSR_FE)
+				up->port.icount.frame++;
+			if (lsr & UART_LSR_OE)
+				up->port.icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ignored.
+			 */
+			lsr &= up->port.read_status_mask;
+
+			if (lsr & UART_LSR_BI) {
+				DEBUG_INTR("handling break....");
+				flag = TTY_BREAK;
+			} else if (lsr & UART_LSR_PE)
+				flag = TTY_PARITY;
+			else if (lsr & UART_LSR_FE)
+				flag = TTY_FRAME;
+		}
+		if (uart_handle_sysrq_char(&up->port, ch))
+			goto ignore_char;
+
+		uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
+
+ignore_char:
+		lsr = serial_inp(up, UART_LSR);
+	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
+	spin_unlock(&up->port.lock);
+	tty_flip_buffer_push(tty);
+	spin_lock(&up->port.lock);
+	*status = lsr;
+}
+
+static void transmit_chars(struct uart_8250_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)) {
+		serial8250_stop_tx(&up->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]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		up->port.icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	DEBUG_INTR("THRE...");
+
+	if (uart_circ_empty(xmit))
+		__stop_tx(up);
+}
+
+static unsigned int check_modem_status(struct uart_8250_port *up)
+{
+	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 &&
+	    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;
+}
+
+/*
+ * This handles the interrupt from one port.
+ */
+static void serial8250_handle_port(struct uart_8250_port *up)
+{
+	unsigned int status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	status = serial_inp(up, UART_LSR);
+
+	DEBUG_INTR("status = %x...", status);
+
+	if (status & (UART_LSR_DR | UART_LSR_BI))
+		receive_chars(up, &status);
+	check_modem_status(up);
+	if (status & UART_LSR_THRE)
+		transmit_chars(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/*
+ * 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;
+
+	DEBUG_INTR("serial8250_interrupt(%d)...", irq);
+
+	spin_lock(&i->lock);
+
+	l = i->head;
+	do {
+		struct uart_8250_port *up;
+		unsigned int iir;
+
+		up = list_entry(l, struct uart_8250_port, list);
+
+		iir = serial_in(up, UART_IIR);
+		if (!(iir & UART_IIR_NO_INT)) {
+			serial8250_handle_port(up);
+
+			handled = 1;
+
+			end = NULL;
+		} else if ((up->port.iotype == UPIO_DWAPB ||
+			    up->port.iotype == UPIO_DWAPB32) &&
+			  (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
+			/* The DesignWare APB UART has an Busy Detect (0x07)
+			 * interrupt meaning an LCR write attempt occured while the
+			 * UART was busy. The interrupt must be cleared by reading
+			 * the UART status register (USR) and the LCR re-written. */
+			unsigned int status;
+			status = *(volatile u32 *)up->port.private_data;
+			serial_out(up, UART_LCR, up->lcr);
+
+			handled = 1;
+
+			end = NULL;
+		} else if (end == NULL)
+			end = l;
+
+		l = l->next;
+
+		if (l == i->head && pass_counter++ > PASS_LIMIT) {
+			/* If we hit this, we're dead. */
+			printk_ratelimited(KERN_ERR
+				"serial8250: too much work for irq%d\n", irq);
+			break;
+		}
+	} while (l != end);
+
+	spin_unlock(&i->lock);
+
+	DEBUG_INTR("end.\n");
+
+	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 hlist_node *n;
+	struct irq_info *i;
+	int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
+
+	mutex_lock(&hash_mutex);
+
+	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+
+	hlist_for_each(n, h) {
+		i = hlist_entry(n, struct irq_info, node);
+		if (i->irq == up->port.irq)
+			break;
+	}
+
+	if (n == 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);
+		irq_flags |= up->port.irqflags;
+		ret = request_irq(up->port.irq, serial8250_interrupt,
+				  irq_flags, "serial", 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_node *n;
+	struct hlist_head *h;
+
+	mutex_lock(&hash_mutex);
+
+	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+
+	hlist_for_each(n, h) {
+		i = hlist_entry(n, struct irq_info, node);
+		if (i->irq == up->port.irq)
+			break;
+	}
+
+	BUG_ON(n == 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(unsigned long data)
+{
+	struct uart_8250_port *up = (struct uart_8250_port *)data;
+	unsigned int iir;
+
+	iir = serial_in(up, UART_IIR);
+	if (!(iir & UART_IIR_NO_INT))
+		serial8250_handle_port(up);
+	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
+}
+
+static void serial8250_backup_timeout(unsigned long data)
+{
+	struct uart_8250_port *up = (struct uart_8250_port *)data;
+	unsigned int iir, ier = 0, lsr;
+	unsigned long flags;
+
+	/*
+	 * Must disable interrupts or else we risk racing with the interrupt
+	 * based handler.
+	 */
+	if (is_real_interrupt(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.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+	lsr = serial_in(up, UART_LSR);
+	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	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_handle_port(up);
+
+	if (is_real_interrupt(up->port.irq))
+		serial_out(up, UART_IER, ier);
+
+	/* Standard timer interval plus 0.2s to keep the port running */
+	mod_timer(&up->timer,
+		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
+}
+
+static unsigned int serial8250_tx_empty(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	unsigned long flags;
+	unsigned int lsr;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	lsr = serial_in(up, UART_LSR);
+	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int serial8250_get_mctrl(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	unsigned int status;
+	unsigned int ret;
+
+	status = check_modem_status(up);
+
+	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 serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_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 = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
+
+	serial_out(up, UART_MCR, mcr);
+}
+
+static void serial8250_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_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);
+}
+
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(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_in(up, UART_LSR);
+
+		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
+
+		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 = 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 =
+		container_of(port, struct uart_8250_port, port);
+	unsigned char lsr = serial_inp(up, UART_LSR);
+
+	if (!(lsr & UART_LSR_DR))
+		return NO_POLL_CHAR;
+
+	return serial_inp(up, UART_RX);
+}
+
+
+static void serial8250_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+
+	wait_for_xmitr(up, BOTH_EMPTY);
+	/*
+	 *	Send the character out.
+	 *	If a LF, also do CR...
+	 */
+	serial_out(up, UART_TX, c);
+	if (c == 10) {
+		wait_for_xmitr(up, BOTH_EMPTY);
+		serial_out(up, UART_TX, 13);
+	}
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, BOTH_EMPTY);
+	serial_out(up, UART_IER, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static int serial8250_startup(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	unsigned long flags;
+	unsigned char lsr, iir;
+	int retval;
+
+	up->port.fifosize = uart_config[up->port.type].fifo_size;
+	up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
+	up->capabilities = uart_config[up->port.type].flags;
+	up->mcr = 0;
+
+	if (up->port.iotype != up->cur_iotype)
+		set_io_from_upio(port);
+
+	if (up->port.type == PORT_16C950) {
+		/* Wake up and initialize UART */
+		up->acr = 0;
+		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		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())
+	 */
+	serial8250_clear_fifos(up);
+
+	/*
+	 * 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(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
+		       serial_index(&up->port));
+		return -ENODEV;
+	}
+
+	/*
+	 * For a XR16C850, we need to set the trigger levels
+	 */
+	if (up->port.type == PORT_16850) {
+		unsigned char fctr;
+
+		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+		fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
+		serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
+		serial_outp(up, UART_TRG, UART_TRG_96);
+		serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
+		serial_outp(up, UART_TRG, UART_TRG_96);
+
+		serial_outp(up, UART_LCR, 0);
+	}
+
+	if (is_real_interrupt(up->port.irq)) {
+		unsigned char iir1;
+		/*
+		 * 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.
+		 */
+		spin_lock_irqsave(&up->port.lock, flags);
+		if (up->port.irqflags & IRQF_SHARED)
+			disable_irq_nosync(up->port.irq);
+
+		wait_for_xmitr(up, UART_LSR_THRE);
+		serial_out_sync(up, UART_IER, UART_IER_THRI);
+		udelay(1); /* allow THRE to set */
+		iir1 = serial_in(up, UART_IIR);
+		serial_out(up, UART_IER, 0);
+		serial_out_sync(up, UART_IER, UART_IER_THRI);
+		udelay(1); /* allow a working UART time to re-assert THRE */
+		iir = serial_in(up, UART_IIR);
+		serial_out(up, UART_IER, 0);
+
+		if (up->port.irqflags & IRQF_SHARED)
+			enable_irq(up->port.irq);
+		spin_unlock_irqrestore(&up->port.lock, flags);
+
+		/*
+		 * If the interrupt is not reasserted, setup a timer to
+		 * kick the UART on a regular basis.
+		 */
+		if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
+			up->bugs |= UART_BUG_THRE;
+			pr_debug("ttyS%d - using backup timer\n",
+				 serial_index(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) {
+		up->timer.function = serial8250_backup_timeout;
+		up->timer.data = (unsigned long)up;
+		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 (!is_real_interrupt(up->port.irq)) {
+		up->timer.data = (unsigned long)up;
+		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
+	} else {
+		retval = serial_link_irq_chain(up);
+		if (retval)
+			return retval;
+	}
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_outp(up, UART_LCR, UART_LCR_WLEN8);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (up->port.flags & UPF_FOURPORT) {
+		if (!is_real_interrupt(up->port.irq))
+			up->port.mctrl |= TIOCM_OUT1;
+	} else
+		/*
+		 * Most PC uarts need OUT2 raised to enable interrupts.
+		 */
+		if (is_real_interrupt(up->port.irq))
+			up->port.mctrl |= TIOCM_OUT2;
+
+	serial8250_set_mctrl(&up->port, up->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 (skip_txen_test || up->port.flags & UPF_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_outp(up, UART_IER, UART_IER_THRI);
+	lsr = serial_in(up, UART_LSR);
+	iir = serial_in(up, UART_IIR);
+	serial_outp(up, UART_IER, 0);
+
+	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
+		if (!(up->bugs & UART_BUG_TXEN)) {
+			up->bugs |= UART_BUG_TXEN;
+			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
+				 serial_index(port));
+		}
+	} else {
+		up->bugs &= ~UART_BUG_TXEN;
+	}
+
+dont_test_tx_en:
+	spin_unlock_irqrestore(&up->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_inp(up, UART_LSR);
+	serial_inp(up, UART_RX);
+	serial_inp(up, UART_IIR);
+	serial_inp(up, UART_MSR);
+	up->lsr_saved_flags = 0;
+	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_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);
+	}
+
+	return 0;
+}
+
+static void serial8250_shutdown(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_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;
+
+	serial8250_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);
+	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.
+	 */
+	(void) serial_in(up, UART_RX);
+
+	del_timer_sync(&up->timer);
+	up->timer.function = serial8250_timeout;
+	if (is_real_interrupt(up->port.irq))
+		serial_unlink_irq_chain(up);
+}
+
+static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
+{
+	unsigned int quot;
+
+	/*
+	 * Handle magic divisors for baud rates above baud_base on
+	 * SMSC SuperIO chips.
+	 */
+	if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
+	    baud == (port->uartclk/4))
+		quot = 0x8001;
+	else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
+		 baud == (port->uartclk/8))
+		quot = 0x8002;
+	else
+		quot = uart_get_divisor(port, baud);
+
+	return quot;
+}
+
+void
+serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
+		          struct ktermios *old)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	unsigned char cval, fcr = 0;
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		cval = UART_LCR_WLEN5;
+		break;
+	case CS6:
+		cval = UART_LCR_WLEN6;
+		break;
+	case CS7:
+		cval = UART_LCR_WLEN7;
+		break;
+	default:
+	case CS8:
+		cval = UART_LCR_WLEN8;
+		break;
+	}
+
+	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;
+#ifdef CMSPAR
+	if (termios->c_cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+#endif
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / 16 / 0xffff,
+				  port->uartclk / 16);
+	quot = serial8250_get_divisor(port, baud);
+
+	/*
+	 * Oxford Semi 952 rev B workaround
+	 */
+	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
+		quot++;
+
+	if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
+		if (baud < 2400)
+			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
+		else
+			fcr = uart_config[up->port.type].fcr;
+	}
+
+	/*
+	 * 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.  In the case where
+	 * the remote UART is not using CTS auto flow control, we must
+	 * have sufficient FIFO entries for the latency of the remote
+	 * UART to respond.  IOW, at least 32 bytes of FIFO.
+	 */
+	if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
+		up->mcr &= ~UART_MCR_AFE;
+		if (termios->c_cflag & CRTSCTS)
+			up->mcr |= UART_MCR_AFE;
+	}
+
+	/*
+	 * 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;
+
+	/*
+	 * Characteres 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 (!(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 | UART_IER_RTOIE;
+
+	serial_out(up, 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_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_outp(up, UART_EFR, efr);
+	}
+
+#ifdef CONFIG_ARCH_OMAP
+	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
+	if (cpu_is_omap1510() && is_omap_port(up)) {
+		if (baud == 115200) {
+			quot = 1;
+			serial_out(up, UART_OMAP_OSC_12M_SEL, 1);
+		} else
+			serial_out(up, UART_OMAP_OSC_12M_SEL, 0);
+	}
+#endif
+
+	if (up->capabilities & UART_NATSEMI) {
+		/* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
+		serial_outp(up, UART_LCR, 0xe0);
+	} else {
+		serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
+	}
+
+	serial_dl_write(up, quot);
+
+	/*
+	 * 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 (up->port.type == PORT_16750)
+		serial_outp(up, UART_FCR, 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 */
+	}
+	serial8250_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	/* 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,
+		       struct ktermios *old)
+{
+	if (port->set_termios)
+		port->set_termios(port, termios, old);
+	else
+		serial8250_do_set_termios(port, termios, old);
+}
+
+static void
+serial8250_set_ldisc(struct uart_port *port, int new)
+{
+	if (new == N_PPS) {
+		port->flags |= UPF_HARDPPS_CD;
+		serial8250_enable_ms(port);
+	} else
+		port->flags &= ~UPF_HARDPPS_CD;
+}
+
+
+void serial8250_do_pm(struct uart_port *port, unsigned int state,
+		      unsigned int oldstate)
+{
+	struct uart_8250_port *p =
+		container_of(port, struct uart_8250_port, 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.iotype == UPIO_AU)
+		return 0x1000;
+#ifdef CONFIG_ARCH_OMAP
+	if (is_omap_port(pt))
+		return 0x16 << pt->port.regshift;
+#endif
+	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);
+	int ret = 0;
+
+	switch (up->port.iotype) {
+	case UPIO_AU:
+	case UPIO_TSI:
+	case UPIO_MEM32:
+	case UPIO_MEM:
+	case UPIO_DWAPB:
+	case UPIO_DWAPB32:
+		if (!up->port.mapbase)
+			break;
+
+		if (!request_mem_region(up->port.mapbase, size, "serial")) {
+			ret = -EBUSY;
+			break;
+		}
+
+		if (up->port.flags & UPF_IOREMAP) {
+			up->port.membase = ioremap_nocache(up->port.mapbase,
+									size);
+			if (!up->port.membase) {
+				release_mem_region(up->port.mapbase, size);
+				ret = -ENOMEM;
+			}
+		}
+		break;
+
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		if (!request_region(up->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);
+
+	switch (up->port.iotype) {
+	case UPIO_AU:
+	case UPIO_TSI:
+	case UPIO_MEM32:
+	case UPIO_MEM:
+	case UPIO_DWAPB:
+	case UPIO_DWAPB32:
+		if (!up->port.mapbase)
+			break;
+
+		if (up->port.flags & UPF_IOREMAP) {
+			iounmap(up->port.membase);
+			up->port.membase = NULL;
+		}
+
+		release_mem_region(up->port.mapbase, size);
+		break;
+
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		release_region(up->port.iobase, size);
+		break;
+	}
+}
+
+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;
+	int ret = -EINVAL;
+
+	switch (up->port.iotype) {
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		start += up->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;
+
+	switch (up->port.iotype) {
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		release_region(up->port.iobase + offset, size);
+		break;
+	}
+}
+
+static void serial8250_release_port(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	serial8250_release_std_resource(up);
+	if (up->port.type == PORT_RSA)
+		serial8250_release_rsa_resource(up);
+}
+
+static int serial8250_request_port(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	int ret = 0;
+
+	ret = serial8250_request_std_resource(up);
+	if (ret == 0 && up->port.type == PORT_RSA) {
+		ret = serial8250_request_rsa_resource(up);
+		if (ret < 0)
+			serial8250_release_std_resource(up);
+	}
+
+	return ret;
+}
+
+static void serial8250_config_port(struct uart_port *port, int flags)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+	int probeflags = PROBE_ANY;
+	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;
+
+	ret = serial8250_request_rsa_resource(up);
+	if (ret < 0)
+		probeflags &= ~PROBE_RSA;
+
+	if (up->port.iotype != up->cur_iotype)
+		set_io_from_upio(port);
+
+	if (flags & UART_CONFIG_TYPE)
+		autoconfig(up, probeflags);
+
+	/* if access method is AU, it is a 16550 with a quirk */
+	if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
+		up->bugs |= UART_BUG_NOMSR;
+
+	if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
+		autoconfig_irq(up);
+
+	if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
+		serial8250_release_rsa_resource(up);
+	if (up->port.type == PORT_UNKNOWN)
+		serial8250_release_std_resource(up);
+}
+
+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 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,
+	.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
+};
+
+static struct uart_8250_port serial8250_ports[UART_NR];
+
+static void (*serial8250_isa_config)(int port, struct uart_port *up,
+	unsigned short *capabilities);
+
+void serial8250_set_isa_configurator(
+	void (*v)(int port, struct uart_port *up, unsigned short *capabilities))
+{
+	serial8250_isa_config = v;
+}
+EXPORT_SYMBOL(serial8250_set_isa_configurator);
+
+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;
+
+	for (i = 0; i < nr_uarts; i++) {
+		struct uart_8250_port *up = &serial8250_ports[i];
+
+		up->port.line = i;
+		spin_lock_init(&up->port.lock);
+
+		init_timer(&up->timer);
+		up->timer.function = serial8250_timeout;
+
+		/*
+		 * ALPHA_KLUDGE_MCR needs to be killed.
+		 */
+		up->mcr_mask = ~ALPHA_KLUDGE_MCR;
+		up->mcr_force = ALPHA_KLUDGE_MCR;
+
+		up->port.ops = &serial8250_pops;
+	}
+
+	if (share_irqs)
+		irqflag = IRQF_SHARED;
+
+	for (i = 0, up = serial8250_ports;
+	     i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
+	     i++, up++) {
+		up->port.iobase   = old_serial_port[i].port;
+		up->port.irq      = irq_canonicalize(old_serial_port[i].irq);
+		up->port.irqflags = old_serial_port[i].irqflags;
+		up->port.uartclk  = old_serial_port[i].baud_base * 16;
+		up->port.flags    = old_serial_port[i].flags;
+		up->port.hub6     = old_serial_port[i].hub6;
+		up->port.membase  = old_serial_port[i].iomem_base;
+		up->port.iotype   = old_serial_port[i].io_type;
+		up->port.regshift = old_serial_port[i].iomem_reg_shift;
+		set_io_from_upio(&up->port);
+		up->port.irqflags |= irqflag;
+		if (serial8250_isa_config != NULL)
+			serial8250_isa_config(i, &up->port, &up->capabilities);
+
+	}
+}
+
+static void
+serial8250_init_fixed_type_port(struct uart_8250_port *up, unsigned int type)
+{
+	up->port.type = type;
+	up->port.fifosize = uart_config[type].fifo_size;
+	up->capabilities = uart_config[type].flags;
+	up->tx_loadsz = uart_config[type].tx_loadsz;
+}
+
+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];
+		up->cur_iotype = 0xFF;
+	}
+
+	serial8250_isa_init_ports();
+
+	for (i = 0; i < nr_uarts; i++) {
+		struct uart_8250_port *up = &serial8250_ports[i];
+
+		up->port.dev = dev;
+
+		if (up->port.flags & UPF_FIXED_TYPE)
+			serial8250_init_fixed_type_port(up, up->port.type);
+
+		uart_add_one_port(drv, &up->port);
+	}
+}
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+static void serial8250_console_putchar(struct uart_port *port, int ch)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	wait_for_xmitr(up, UART_LSR_THRE);
+	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
+serial8250_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_8250_port *up = &serial8250_ports[co->index];
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	touch_nmi_watchdog();
+
+	local_irq_save(flags);
+	if (up->port.sysrq) {
+		/* serial8250_handle_port() already took the lock */
+		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);
+
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+
+	uart_console_write(&up->port, s, count, serial8250_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, BOTH_EMPTY);
+	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 serial8250_console_setup(struct console *co, char *options)
+{
+	struct uart_port *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 (co->index >= nr_uarts)
+		co->index = 0;
+	port = &serial8250_ports[co->index].port;
+	if (!port->iobase && !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 int serial8250_console_early_setup(void)
+{
+	return serial8250_find_port_for_earlycon();
+}
+
+static struct console serial8250_console = {
+	.name		= "ttyS",
+	.write		= serial8250_console_write,
+	.device		= uart_console_device,
+	.setup		= serial8250_console_setup,
+	.early_setup	= serial8250_console_early_setup,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+	.index		= -1,
+	.data		= &serial8250_reg,
+};
+
+static int __init serial8250_console_init(void)
+{
+	if (nr_uarts > UART_NR)
+		nr_uarts = UART_NR;
+
+	serial8250_isa_init_ports();
+	register_console(&serial8250_console);
+	return 0;
+}
+console_initcall(serial8250_console_init);
+
+int serial8250_find_port(struct uart_port *p)
+{
+	int line;
+	struct uart_port *port;
+
+	for (line = 0; line < nr_uarts; line++) {
+		port = &serial8250_ports[line].port;
+		if (uart_match_port(p, port))
+			return line;
+	}
+	return -ENODEV;
+}
+
+#define SERIAL8250_CONSOLE	&serial8250_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))
+		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->private_data = port->private_data;
+	p->type		= port->type;
+	p->line		= port->line;
+
+	set_io_from_upio(p);
+	if (port->serial_in)
+		p->serial_in = port->serial_in;
+	if (port->serial_out)
+		p->serial_out = port->serial_out;
+
+	return 0;
+}
+
+/**
+ *	serial8250_suspend_port - suspend one serial port
+ *	@line:  serial line number
+ *
+ *	Suspend one serial port.
+ */
+void serial8250_suspend_port(int line)
+{
+	uart_suspend_port(&serial8250_reg, &serial8250_ports[line].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];
+
+	if (up->capabilities & UART_NATSEMI) {
+		unsigned char tmp;
+
+		/* Ensure it's still in high speed mode */
+		serial_outp(up, UART_LCR, 0xE0);
+
+		tmp = serial_in(up, 0x04); /* EXCR2 */
+		tmp &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
+		tmp |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
+		serial_outp(up, 0x04, tmp);
+
+		serial_outp(up, UART_LCR, 0);
+	}
+	uart_resume_port(&serial8250_reg, &up->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 __devinit serial8250_probe(struct platform_device *dev)
+{
+	struct plat_serial8250_port *p = dev->dev.platform_data;
+	struct uart_port port;
+	int ret, i, irqflag = 0;
+
+	memset(&port, 0, sizeof(struct uart_port));
+
+	if (share_irqs)
+		irqflag = IRQF_SHARED;
+
+	for (i = 0; p && p->flags != 0; p++, i++) {
+		port.iobase		= p->iobase;
+		port.membase		= p->membase;
+		port.irq		= p->irq;
+		port.irqflags		= p->irqflags;
+		port.uartclk		= p->uartclk;
+		port.regshift		= p->regshift;
+		port.iotype		= p->iotype;
+		port.flags		= p->flags;
+		port.mapbase		= p->mapbase;
+		port.hub6		= p->hub6;
+		port.private_data	= p->private_data;
+		port.type		= p->type;
+		port.serial_in		= p->serial_in;
+		port.serial_out		= p->serial_out;
+		port.set_termios	= p->set_termios;
+		port.pm			= p->pm;
+		port.dev		= &dev->dev;
+		port.irqflags		|= irqflag;
+		ret = serial8250_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 __devexit 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		= __devexit_p(serial8250_remove),
+	.suspend	= serial8250_suspend,
+	.resume		= serial8250_resume,
+	.driver		= {
+		.name	= "serial8250",
+		.owner	= THIS_MODULE,
+	},
+};
+
+/*
+ * 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_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(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];
+
+	/*
+	 * 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;
+}
+
+/**
+ *	serial8250_register_port - register a serial port
+ *	@port: 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_port(struct uart_port *port)
+{
+	struct uart_8250_port *uart;
+	int ret = -ENOSPC;
+
+	if (port->uartclk == 0)
+		return -EINVAL;
+
+	mutex_lock(&serial_mutex);
+
+	uart = serial8250_find_match_or_unused(port);
+	if (uart) {
+		uart_remove_one_port(&serial8250_reg, &uart->port);
+
+		uart->port.iobase       = port->iobase;
+		uart->port.membase      = port->membase;
+		uart->port.irq          = port->irq;
+		uart->port.irqflags     = port->irqflags;
+		uart->port.uartclk      = port->uartclk;
+		uart->port.fifosize     = port->fifosize;
+		uart->port.regshift     = port->regshift;
+		uart->port.iotype       = port->iotype;
+		uart->port.flags        = port->flags | UPF_BOOT_AUTOCONF;
+		uart->port.mapbase      = port->mapbase;
+		uart->port.private_data = port->private_data;
+		if (port->dev)
+			uart->port.dev = port->dev;
+
+		if (port->flags & UPF_FIXED_TYPE)
+			serial8250_init_fixed_type_port(uart, port->type);
+
+		set_io_from_upio(&uart->port);
+		/* Possibly override default I/O functions.  */
+		if (port->serial_in)
+			uart->port.serial_in = port->serial_in;
+		if (port->serial_out)
+			uart->port.serial_out = port->serial_out;
+		/*  Possibly override set_termios call */
+		if (port->set_termios)
+			uart->port.set_termios = port->set_termios;
+		if (port->pm)
+			uart->port.pm = port->pm;
+
+		if (serial8250_isa_config != NULL)
+			serial8250_isa_config(0, &uart->port,
+					&uart->capabilities);
+
+		ret = uart_add_one_port(&serial8250_reg, &uart->port);
+		if (ret == 0)
+			ret = uart->port.line;
+	}
+	mutex_unlock(&serial_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(serial8250_register_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);
+	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_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 > UART_NR)
+		nr_uarts = UART_NR;
+
+	printk(KERN_INFO "Serial: 8250/16550 driver, "
+		"%d ports, IRQ sharing %sabled\n", nr_uarts,
+		share_irqs ? "en" : "dis");
+
+#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;
+
+	serial8250_isa_devs = platform_device_alloc("serial8250",
+						    PLAT8250_DEV_LEGACY);
+	if (!serial8250_isa_devs) {
+		ret = -ENOMEM;
+		goto unreg_uart_drv;
+	}
+
+	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_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);
+
+#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);
+
+EXPORT_SYMBOL(serial8250_suspend_port);
+EXPORT_SYMBOL(serial8250_resume_port);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
+
+module_param(share_irqs, uint, 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_array(probe_rsa, ulong, &probe_rsa_count, 0444);
+MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
+#endif
+MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);