8250.c 75.6 KB
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/*
 *  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>
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#include <linux/platform_device.h>
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#include <linux/tty.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>
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#include <linux/nmi.h>
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#include <linux/mutex.h>
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#include <asm/io.h>
#include <asm/irq.h>

#include "8250.h"

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#ifdef CONFIG_SPARC
#include "suncore.h"
#endif

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/*
 * Configuration:
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 *   share_irqs - whether we pass IRQF_SHARED to request_irq().  This option
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 *                is unsafe when used on edge-triggered interrupts.
 */
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static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
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static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;

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/*
 * 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

/*
 * 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

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#include <asm/serial.h>
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/*
 * 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

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static const struct old_serial_port old_serial_port[] = {
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	SERIAL_PORT_DFNS /* defined in asm/serial.h */
};

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#define UART_NR	CONFIG_SERIAL_8250_NR_UARTS
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#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 */
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	unsigned short		capabilities;	/* port capabilities */
	unsigned short		bugs;		/* port bugs */
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	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 */
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	/*
	 * 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;
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	/*
	 * We provide a per-port pm hook.
	 */
	void			(*pm)(struct uart_port *port,
				      unsigned int state, unsigned int old);
};

struct irq_info {
	spinlock_t		lock;
	struct list_head	*head;
};

static struct irq_info irq_lists[NR_IRQS];

/*
 * 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,
	},
	[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,
	},
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	[PORT_RM9000] = {
		.name		= "RM9000",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO,
	},
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};

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#if defined (CONFIG_SERIAL_8250_AU1X00)
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/* 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_8250_port *up, int offset)
{
	if (up->port.iotype != UPIO_AU)
		return offset;
	return au_io_in_map[offset];
}

static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
{
	if (up->port.iotype != UPIO_AU)
		return offset;
	return au_io_out_map[offset];
}

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#elif defined(CONFIG_SERIAL_8250_RM9K)
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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_8250_port *up, int offset)
{
	if (up->port.iotype != UPIO_RM9000)
		return offset;
	return regmap_in[offset];
}

static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
{
	if (up->port.iotype != UPIO_RM9000)
		return offset;
	return regmap_out[offset];
}

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#else

/* sane hardware needs no mapping */
#define map_8250_in_reg(up, offset) (offset)
#define map_8250_out_reg(up, offset) (offset)

#endif

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static unsigned int serial_in(struct uart_8250_port *up, int offset)
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{
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	unsigned int tmp;
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	offset = map_8250_in_reg(up, offset) << up->port.regshift;
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	switch (up->port.iotype) {
	case UPIO_HUB6:
		outb(up->port.hub6 - 1 + offset, up->port.iobase);
		return inb(up->port.iobase + 1);

	case UPIO_MEM:
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	case UPIO_DWAPB:
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		return readb(up->port.membase + offset);

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	case UPIO_RM9000:
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	case UPIO_MEM32:
		return readl(up->port.membase + offset);

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#ifdef CONFIG_SERIAL_8250_AU1X00
	case UPIO_AU:
		return __raw_readl(up->port.membase + offset);
#endif

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	case UPIO_TSI:
		if (offset == UART_IIR) {
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			tmp = readl(up->port.membase + (UART_IIR & ~3));
			return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
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		} else
			return readb(up->port.membase + offset);

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	default:
		return inb(up->port.iobase + offset);
	}
}

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static void
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serial_out(struct uart_8250_port *up, int offset, int value)
{
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	/* Save the offset before it's remapped */
	int save_offset = offset;
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	offset = map_8250_out_reg(up, offset) << up->port.regshift;
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	switch (up->port.iotype) {
	case UPIO_HUB6:
		outb(up->port.hub6 - 1 + offset, up->port.iobase);
		outb(value, up->port.iobase + 1);
		break;

	case UPIO_MEM:
		writeb(value, up->port.membase + offset);
		break;

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	case UPIO_RM9000:
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	case UPIO_MEM32:
		writel(value, up->port.membase + offset);
		break;

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#ifdef CONFIG_SERIAL_8250_AU1X00
	case UPIO_AU:
		__raw_writel(value, up->port.membase + offset);
		break;
#endif
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	case UPIO_TSI:
		if (!((offset == UART_IER) && (value & UART_IER_UUE)))
			writeb(value, up->port.membase + offset);
		break;
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	case UPIO_DWAPB:
		/* Save the LCR value so it can be re-written when a
		 * Busy Detect interrupt occurs. */
		if (save_offset == UART_LCR)
			up->lcr = value;
		writeb(value, up->port.membase + offset);
		/* Read the IER to ensure any interrupt is cleared before
		 * returning from ISR. */
		if (save_offset == UART_TX || save_offset == UART_IER)
			value = serial_in(up, UART_IER);
		break;

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	default:
		outb(value, up->port.iobase + offset);
	}
}

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static void
serial_out_sync(struct uart_8250_port *up, int offset, int value)
{
	switch (up->port.iotype) {
	case UPIO_MEM:
	case UPIO_MEM32:
#ifdef CONFIG_SERIAL_8250_AU1X00
	case UPIO_AU:
#endif
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	case UPIO_DWAPB:
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		serial_out(up, offset, value);
		serial_in(up, UART_LCR);	/* safe, no side-effects */
		break;
	default:
		serial_out(up, offset, value);
	}
}

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/*
 * 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)

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/* 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);
}

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#if defined(CONFIG_SERIAL_8250_AU1X00)
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/* 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);
}
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#elif defined(CONFIG_SERIAL_8250_RM9K)
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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);
	}
}
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#else
#define serial_dl_read(up) _serial_dl_read(up)
#define serial_dl_write(up, value) _serial_dl_write(up, value)
#endif
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/*
 * 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.
 */
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static void serial8250_clear_fifos(struct uart_8250_port *p)
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{
	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.
 */
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static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
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{
	if (p->capabilities & UART_CAP_SLEEP) {
		if (p->capabilities & UART_CAP_EFR) {
			serial_outp(p, UART_LCR, 0xBF);
			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, 0xBF);
			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)
{
650 651
	unsigned char old_fcr, old_mcr, old_lcr;
	unsigned short old_dl;
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	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_DLAB);
662 663
	old_dl = serial_dl_read(up);
	serial_dl_write(up, 0x0001);
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	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_DLAB);
674
	serial_dl_write(up, old_dl);
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	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_DLAB);

	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.)
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 * 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, 0xBF);
	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;
758 759 760 761 762 763 764 765

		/*
		 * 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;
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		return;
	}
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	/*
	 * 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://www.exar.com/info.php?pdf=dan180_oct2004.pdf
	 */
	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_DLAB);
	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, 0xBF);
	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) {
900 901
			unsigned short quot;

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			serial_outp(up, UART_LCR, 0xE0);
903

904
			quot = serial_dl_read(up);
905 906
			quot <<= 3;

907
			status1 = serial_in(up, 0x04); /* EXCR2 */
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			status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
			status1 |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
			serial_outp(up, 0x04, status1);
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912
			serial_dl_write(up, quot);
913

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			serial_outp(up, UART_LCR, 0);

916
			up->port.uartclk = 921600*16;
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			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_DLAB);
	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);
}

/*
 * 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%04x, 0x%p): ",
			up->port.line, 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;
1009
	up->bugs = 0;
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	if (!(up->port.flags & UPF_BUGGY_UART)) {
		/*
		 * Do a simple existence test first; if we fail this,
		 * there's no point trying anything else.
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		 *
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		 * 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
1030 1031 1032 1033 1034
		/*
		 * 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;
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		serial_outp(up, UART_IER, 0x0F);
#ifdef __i386__
		outb(0, 0x080);
#endif
1039
		scratch3 = serial_inp(up, UART_IER) & 0x0f;
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		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);

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	/*
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	 * 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
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	 * out if it's 8250 or 16450, 16550, 16550A or later.  This
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	 * 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, 0xBF);
	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
1123 1124 1125 1126 1127 1128 1129

#ifdef CONFIG_SERIAL_8250_AU1X00
	/* 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;
#endif

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	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",
			up->port.line, 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);
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	serial_in(up, UART_RX);
1156 1157 1158 1159
	if (up->capabilities & UART_CAP_UUE)
		serial_outp(up, UART_IER, UART_IER_UUE);
	else
		serial_outp(up, UART_IER, 0);
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 out:
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	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);
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	irqs = probe_irq_on();
	serial_outp(up, UART_MCR, 0);
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	udelay(10);
	if (up->port.flags & UPF_FOURPORT) {
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		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);
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	udelay(20);
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	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;
}

1215 1216 1217 1218 1219 1220 1221 1222
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);
	}
}

1223
static void serial8250_stop_tx(struct uart_port *port)
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{
	struct uart_8250_port *up = (struct uart_8250_port *)port;

1227
	__stop_tx(up);
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	/*
1230
	 * We really want to stop the transmitter from sending.
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1231
	 */
1232
	if (up->port.type == PORT_16C950) {
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		up->acr |= UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

1238 1239
static void transmit_chars(struct uart_8250_port *up);

1240
static void serial8250_start_tx(struct uart_port *port)
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{
	struct uart_8250_port *up = (struct uart_8250_port *)port;

	if (!(up->ier & UART_IER_THRI)) {
		up->ier |= UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
1247

1248
		if (up->bugs & UART_BUG_TXEN) {
1249 1250
			unsigned char lsr, iir;
			lsr = serial_in(up, UART_LSR);
1251
			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
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			iir = serial_in(up, UART_IIR) & 0x0f;
			if ((up->port.type == PORT_RM9000) ?
				(lsr & UART_LSR_THRE &&
				(iir == UART_IIR_NO_INT || iir == UART_IIR_THRI)) :
				(lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT))
1257 1258
				transmit_chars(up);
		}
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	}
1260

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	/*
1262
	 * Re-enable the transmitter if we disabled it.
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	 */
1264
	if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
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		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 = (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 = (struct uart_8250_port *)port;

1283 1284 1285 1286
	/* no MSR capabilities */
	if (up->bugs & UART_BUG_NOMSR)
		return;

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	up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
}

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static void
1292
receive_chars(struct uart_8250_port *up, unsigned int *status)
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{
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	struct tty_struct *tty = up->port.info->port.tty;
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	unsigned char ch, lsr = *status;
	int max_count = 256;
	char flag;

	do {
1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311
		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;

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		flag = TTY_NORMAL;
		up->port.icount.rx++;

1315 1316
		lsr |= up->lsr_saved_flags;
		up->lsr_saved_flags = 0;
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1318
		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
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			/*
			 * 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++;

			/*
1341
			 * Mask off conditions which should be ignored.
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			 */
			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;
		}
1353
		if (uart_handle_sysrq_char(&up->port, ch))
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			goto ignore_char;
1355 1356 1357

		uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);

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ignore_char:
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		lsr = serial_inp(up, UART_LSR);
1360
	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
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	spin_unlock(&up->port.lock);
	tty_flip_buffer_push(tty);
	spin_lock(&up->port.lock);
	*status = lsr;
}

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static void transmit_chars(struct uart_8250_port *up)
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{
	struct circ_buf *xmit = &up->port.info->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;
	}
1378 1379 1380 1381 1382
	if (uart_tx_stopped(&up->port)) {
		serial8250_stop_tx(&up->port);
		return;
	}
	if (uart_circ_empty(xmit)) {
1383
		__stop_tx(up);
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		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))
1402
		__stop_tx(up);
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}

1405
static unsigned int check_modem_status(struct uart_8250_port *up)
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{
1407 1408
	unsigned int status = serial_in(up, UART_MSR);

1409 1410
	status |= up->msr_saved_flags;
	up->msr_saved_flags = 0;
1411 1412
	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
	    up->port.info != NULL) {
1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423
		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.info->delta_msr_wait);
	}
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1425
	return status;
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}

/*
 * This handles the interrupt from one port.
 */
1431
static void serial8250_handle_port(struct uart_8250_port *up)
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1432
{
1433
	unsigned int status;
1434
	unsigned long flags;
1435

1436
	spin_lock_irqsave(&up->port.lock, flags);
1437 1438

	status = serial_inp(up, UART_LSR);
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	DEBUG_INTR("status = %x...", status);

1442
	if (status & (UART_LSR_DR | UART_LSR_BI))
1443
		receive_chars(up, &status);
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	check_modem_status(up);
	if (status & UART_LSR_THRE)
		transmit_chars(up);
1447

1448
	spin_unlock_irqrestore(&up->port.lock, flags);
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}

/*
 * 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.
 */
1465
static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
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{
	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)) {
1484
			serial8250_handle_port(up);
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			handled = 1;

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Marc St-Jean 已提交
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			end = NULL;
		} else if (up->port.iotype == UPIO_DWAPB &&
			  (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;

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			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(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);
}

static int serial_link_irq_chain(struct uart_8250_port *up)
{
	struct irq_info *i = irq_lists + up->port.irq;
1548
	int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
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1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582

	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,
				  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 = irq_lists + up->port.irq;

	BUG_ON(i->head == NULL);

	if (list_empty(i->head))
		free_irq(up->port.irq, i);

	serial_do_unlink(i, up);
}

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/* Base timer interval for polling */
static inline int poll_timeout(int timeout)
{
	return timeout > 6 ? (timeout / 2 - 2) : 1;
}

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1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600
/*
 * 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);
1601
	if (!(iir & UART_IIR_NO_INT))
1602
		serial8250_handle_port(up);
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1603 1604 1605 1606 1607 1608
	mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
}

static void serial8250_backup_timeout(unsigned long data)
{
	struct uart_8250_port *up = (struct uart_8250_port *)data;
1609 1610
	unsigned int iir, ier = 0, lsr;
	unsigned long flags;
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1611 1612 1613 1614 1615 1616 1617 1618 1619

	/*
	 * 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);
	}
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1620

A
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1621 1622 1623 1624 1625 1626 1627 1628
	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.
	 */
1629 1630 1631 1632
	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);
A
Alex Williamson 已提交
1633 1634
	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
	    (!uart_circ_empty(&up->port.info->xmit) || up->port.x_char) &&
1635
	    (lsr & UART_LSR_THRE)) {
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Alex Williamson 已提交
1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646
		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 */
A
Alan Cox 已提交
1647 1648
	mod_timer(&up->timer,
		jiffies + poll_timeout(up->port.timeout) + HZ / 5);
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1649 1650 1651 1652 1653 1654
}

static unsigned int serial8250_tx_empty(struct uart_port *port)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
	unsigned long flags;
1655
	unsigned int lsr;
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	spin_lock_irqsave(&up->port.lock, flags);
1658 1659
	lsr = serial_in(up, UART_LSR);
	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
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	spin_unlock_irqrestore(&up->port.lock, flags);

1662
	return lsr & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
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}

static unsigned int serial8250_get_mctrl(struct uart_port *port)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
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	unsigned int status;
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	unsigned int ret;

1671
	status = check_modem_status(up);
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	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 = (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 = (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);
}

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#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)

/*
 *	Wait for transmitter & holding register to empty
 */
1725
static void wait_for_xmitr(struct uart_8250_port *up, int bits)
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{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
	do {
		status = serial_in(up, UART_LSR);

1733
		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
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		if (--tmout == 0)
			break;
		udelay(1);
	} while ((status & bits) != bits);

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
1742 1743 1744 1745 1746 1747
		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;
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			udelay(1);
			touch_nmi_watchdog();
		}
	}
}

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#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 = (struct uart_8250_port *)port;
	unsigned char lsr = serial_inp(up, UART_LSR);

	while (!(lsr & UART_LSR_DR))
		lsr = serial_inp(up, UART_LSR);

	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 = (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 */

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static int serial8250_startup(struct uart_port *port)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
	unsigned long flags;
1812
	unsigned char lsr, iir;
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	int retval;

	up->capabilities = uart_config[up->port.type].flags;
	up->mcr = 0;

	if (up->port.type == PORT_16C950) {
		/* Wake up and initialize UART */
		up->acr = 0;
		serial_outp(up, UART_LCR, 0xBF);
		serial_outp(up, UART_EFR, UART_EFR_ECB);
		serial_outp(up, UART_IER, 0);
		serial_outp(up, UART_LCR, 0);
		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
		serial_outp(up, UART_LCR, 0xBF);
		serial_outp(up, UART_EFR, UART_EFR_ECB);
		serial_outp(up, UART_LCR, 0);
	}

#ifdef CONFIG_SERIAL_8250_RSA
	/*
	 * If this is an RSA port, see if we can kick it up to the
	 * higher speed clock.
	 */
	enable_rsa(up);
#endif

	/*
	 * Clear the FIFO buffers and disable them.
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	 * (they will be reenabled in set_termios())
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	 */
	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("ttyS%d: LSR safety check engaged!\n", up->port.line);
		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, 0xbf);

		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);
	}

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	if (is_real_interrupt(up->port.irq)) {
1882
		unsigned char iir1;
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		/*
		 * 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.
		 */
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Borislav Petkov 已提交
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		spin_lock_irqsave(&up->port.lock, flags);
1892 1893
		if (up->port.flags & UPF_SHARE_IRQ)
			disable_irq_nosync(up->port.irq);
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		wait_for_xmitr(up, UART_LSR_THRE);
		serial_out_sync(up, UART_IER, UART_IER_THRI);
		udelay(1); /* allow THRE to set */
1898
		iir1 = serial_in(up, UART_IIR);
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		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);

1905 1906
		if (up->port.flags & UPF_SHARE_IRQ)
			enable_irq(up->port.irq);
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		spin_unlock_irqrestore(&up->port.lock, flags);
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		/*
		 * If the interrupt is not reasserted, setup a timer to
		 * kick the UART on a regular basis.
		 */
1913
		if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
1914
			up->bugs |= UART_BUG_THRE;
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			pr_debug("ttyS%d - using backup timer\n", port->line);
		}
	}

1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
	/*
	 * 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 +
			  poll_timeout(up->port.timeout) + HZ / 5);
	}

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	/*
	 * 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;
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		mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
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	} 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);
1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971

	/*
	 * 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) {
1972 1973
		if (!(up->bugs & UART_BUG_TXEN)) {
			up->bugs |= UART_BUG_TXEN;
1974 1975 1976 1977
			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
				 port->line);
		}
	} else {
1978
		up->bugs &= ~UART_BUG_TXEN;
1979 1980
	}

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	spin_unlock_irqrestore(&up->port.lock, flags);

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994
	/*
	 * 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;

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	/*
	 * 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 = (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);

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	del_timer_sync(&up->timer);
	up->timer.function = serial8250_timeout;
	if (is_real_interrupt(up->port.irq))
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		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;
}

static void
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serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
		       struct ktermios *old)
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{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
	unsigned char cval, fcr = 0;
	unsigned long flags;
	unsigned int baud, quot;

	switch (termios->c_cflag & CSIZE) {
	case CS5:
2094
		cval = UART_LCR_WLEN5;
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		break;
	case CS6:
2097
		cval = UART_LCR_WLEN6;
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		break;
	case CS7:
2100
		cval = UART_LCR_WLEN7;
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		break;
	default:
	case CS8:
2104
		cval = UART_LCR_WLEN8;
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		break;
	}

	if (termios->c_cflag & CSTOPB)
2109
		cval |= UART_LCR_STOP;
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	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.
	 */
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	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
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	quot = serial8250_get_divisor(port, baud);

	/*
2126
	 * Oxford Semi 952 rev B workaround
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	 */
2128
	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
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		quot++;
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	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;
2195 2196
	if (!(up->bugs & UART_BUG_NOMSR) &&
			UART_ENABLE_MS(&up->port, termios->c_cflag))
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		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, 0xBF);
		serial_outp(up, UART_EFR, efr);
	}

2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227
#ifdef CONFIG_ARCH_OMAP15XX
	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
	if (cpu_is_omap1510() && is_omap_port((unsigned int)up->port.membase)) {
		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

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	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 */
	}

2235
	serial_dl_write(up, quot);
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	/*
	 * 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);
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	/* Don't rewrite B0 */
	if (tty_termios_baud_rate(termios))
		tty_termios_encode_baud_rate(termios, baud, baud);
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}

static void
serial8250_pm(struct uart_port *port, unsigned int state,
	      unsigned int oldstate)
{
	struct uart_8250_port *p = (struct uart_8250_port *)port;

	serial8250_set_sleep(p, state != 0);

	if (p->pm)
		p->pm(port, state, oldstate);
}

/*
 * Resource handling.
 */
static int serial8250_request_std_resource(struct uart_8250_port *up)
{
	unsigned int size = 8 << up->port.regshift;
	int ret = 0;

	switch (up->port.iotype) {
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	case UPIO_AU:
		size = 0x100000;
		/* fall thru */
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	case UPIO_TSI:
	case UPIO_MEM32:
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	case UPIO_MEM:
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	case UPIO_DWAPB:
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		if (!up->port.mapbase)
			break;

		if (!request_mem_region(up->port.mapbase, size, "serial")) {
			ret = -EBUSY;
			break;
		}

		if (up->port.flags & UPF_IOREMAP) {
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			up->port.membase = ioremap_nocache(up->port.mapbase,
									size);
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			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 = 8 << up->port.regshift;

	switch (up->port.iotype) {
2320 2321 2322
	case UPIO_AU:
		size = 0x100000;
		/* fall thru */
2323 2324
	case UPIO_TSI:
	case UPIO_MEM32:
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	case UPIO_MEM:
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	case UPIO_DWAPB:
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		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;
2349
	int ret = -EINVAL;
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	switch (up->port.iotype) {
	case UPIO_HUB6:
	case UPIO_PORT:
		start += up->port.iobase;
2355 2356 2357
		if (request_region(start, size, "serial-rsa"))
			ret = 0;
		else
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			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 = (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 = (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 = (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 (flags & UART_CONFIG_TYPE)
		autoconfig(up, probeflags);
	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,
	.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,
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#ifdef CONFIG_CONSOLE_POLL
	.poll_get_char = serial8250_get_poll_char,
	.poll_put_char = serial8250_put_poll_char,
#endif
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};

static struct uart_8250_port serial8250_ports[UART_NR];

static void __init serial8250_isa_init_ports(void)
{
	struct uart_8250_port *up;
	static int first = 1;
	int i;

	if (!first)
		return;
	first = 0;

2488
	for (i = 0; i < nr_uarts; i++) {
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		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;
	}

2506
	for (i = 0, up = serial8250_ports;
2507
	     i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
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	     i++, up++) {
		up->port.iobase   = old_serial_port[i].port;
		up->port.irq      = irq_canonicalize(old_serial_port[i].irq);
		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;
		if (share_irqs)
			up->port.flags |= UPF_SHARE_IRQ;
	}
}

static void __init
serial8250_register_ports(struct uart_driver *drv, struct device *dev)
{
	int i;

	serial8250_isa_init_ports();

2529
	for (i = 0; i < nr_uarts; i++) {
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		struct uart_8250_port *up = &serial8250_ports[i];

		up->port.dev = dev;
		uart_add_one_port(drv, &up->port);
	}
}

#ifdef CONFIG_SERIAL_8250_CONSOLE

2539 2540 2541 2542 2543 2544 2545 2546
static void serial8250_console_putchar(struct uart_port *port, int ch)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;

	wait_for_xmitr(up, UART_LSR_THRE);
	serial_out(up, UART_TX, ch);
}

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/*
 *	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];
2557
	unsigned long flags;
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	unsigned int ier;
2559
	int locked = 1;
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2561 2562
	touch_nmi_watchdog();

2563 2564 2565 2566 2567 2568
	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);
2569
	} else
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		spin_lock(&up->port.lock);
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	/*
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	 *	First save the IER then disable the interrupts
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	 */
	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);

2582
	uart_console_write(&up->port, s, count, serial8250_console_putchar);
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	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the IER
	 */
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	wait_for_xmitr(up, BOTH_EMPTY);
2589
	serial_out(up, UART_IER, ier);
2590

2591 2592 2593 2594 2595 2596 2597 2598 2599 2600
	/*
	 *	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);

2601
	if (locked)
2602 2603
		spin_unlock(&up->port.lock);
	local_irq_restore(flags);
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}

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static int __init serial8250_console_setup(struct console *co, char *options)
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{
	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.
	 */
2619
	if (co->index >= nr_uarts)
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		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);
}

2631
static int serial8250_console_early_setup(void)
2632 2633 2634 2635
{
	return serial8250_find_port_for_earlycon();
}

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static struct uart_driver serial8250_reg;
static struct console serial8250_console = {
	.name		= "ttyS",
	.write		= serial8250_console_write,
	.device		= uart_console_device,
	.setup		= serial8250_console_setup,
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	.early_setup	= serial8250_console_early_setup,
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	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &serial8250_reg,
};

static int __init serial8250_console_init(void)
{
2650 2651 2652
	if (nr_uarts > UART_NR)
		nr_uarts = UART_NR;

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	serial8250_isa_init_ports();
	register_console(&serial8250_console);
	return 0;
}
console_initcall(serial8250_console_init);

2659
int serial8250_find_port(struct uart_port *p)
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{
	int line;
	struct uart_port *port;

2664
	for (line = 0; line < nr_uarts; line++) {
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		port = &serial8250_ports[line].port;
2666
		if (uart_match_port(p, port))
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			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,
};

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/*
 * 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.
 */
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int __init early_serial_setup(struct uart_port *port)
{
	if (port->line >= ARRAY_SIZE(serial8250_ports))
		return -ENODEV;

	serial8250_isa_init_ports();
	serial8250_ports[port->line].port	= *port;
	serial8250_ports[port->line].port.ops	= &serial8250_pops;
	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)
{
2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737
	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);
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}

/*
 * 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.
 */
2745
static int __devinit serial8250_probe(struct platform_device *dev)
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{
2747
	struct plat_serial8250_port *p = dev->dev.platform_data;
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	struct uart_port port;
2749
	int ret, i;
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	memset(&port, 0, sizeof(struct uart_port));

2753
	for (i = 0; p && p->flags != 0; p++, i++) {
2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764
		port.iobase		= p->iobase;
		port.membase		= p->membase;
		port.irq		= p->irq;
		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.dev		= &dev->dev;
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		if (share_irqs)
			port.flags |= UPF_SHARE_IRQ;
2767 2768
		ret = serial8250_register_port(&port);
		if (ret < 0) {
2769
			dev_err(&dev->dev, "unable to register port at index %d "
2770 2771 2772
				"(IO%lx MEM%llx IRQ%d): %d\n", i,
				p->iobase, (unsigned long long)p->mapbase,
				p->irq, ret);
2773
		}
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	}
	return 0;
}

/*
 * Remove serial ports registered against a platform device.
 */
2781
static int __devexit serial8250_remove(struct platform_device *dev)
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{
	int i;

2785
	for (i = 0; i < nr_uarts; i++) {
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		struct uart_8250_port *up = &serial8250_ports[i];

2788
		if (up->port.dev == &dev->dev)
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			serial8250_unregister_port(i);
	}
	return 0;
}

2794
static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
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{
	int i;

	for (i = 0; i < UART_NR; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];

2801
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
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			uart_suspend_port(&serial8250_reg, &up->port);
	}

	return 0;
}

2808
static int serial8250_resume(struct platform_device *dev)
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{
	int i;

	for (i = 0; i < UART_NR; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];

2815
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
2816
			serial8250_resume_port(i);
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	}

	return 0;
}

2822
static struct platform_driver serial8250_isa_driver = {
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	.probe		= serial8250_probe,
	.remove		= __devexit_p(serial8250_remove),
	.suspend	= serial8250_suspend,
	.resume		= serial8250_resume,
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	.driver		= {
		.name	= "serial8250",
2829
		.owner	= THIS_MODULE,
2830
	},
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};

/*
 * 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.
 */
2844
static DEFINE_MUTEX(serial_mutex);
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static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
{
	int i;

	/*
	 * First, find a port entry which matches.
	 */
2853
	for (i = 0; i < nr_uarts; i++)
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		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).
	 */
2862
	for (i = 0; i < nr_uarts; i++)
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		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.
	 */
2871
	for (i = 0; i < nr_uarts; i++)
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		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;

2899
	mutex_lock(&serial_mutex);
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	uart = serial8250_find_match_or_unused(port);
	if (uart) {
		uart_remove_one_port(&serial8250_reg, &uart->port);

2905 2906 2907 2908 2909 2910 2911 2912 2913 2914
		uart->port.iobase       = port->iobase;
		uart->port.membase      = port->membase;
		uart->port.irq          = port->irq;
		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;
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		if (port->dev)
			uart->port.dev = port->dev;

		ret = uart_add_one_port(&serial8250_reg, &uart->port);
		if (ret == 0)
			ret = uart->port.line;
	}
2922
	mutex_unlock(&serial_mutex);
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	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];

2939
	mutex_lock(&serial_mutex);
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	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;
	}
2949
	mutex_unlock(&serial_mutex);
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}
EXPORT_SYMBOL(serial8250_unregister_port);

static int __init serial8250_init(void)
{
	int ret, i;

2957 2958 2959
	if (nr_uarts > UART_NR)
		nr_uarts = UART_NR;

2960
	printk(KERN_INFO "Serial: 8250/16550 driver"
2961
		"%d ports, IRQ sharing %sabled\n", nr_uarts,
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		share_irqs ? "en" : "dis");

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#ifdef CONFIG_SPARC
	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
#else
	serial8250_reg.nr = UART_NR;
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	ret = uart_register_driver(&serial8250_reg);
2969
#endif
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	if (ret)
		goto out;

2973 2974 2975 2976
	serial8250_isa_devs = platform_device_alloc("serial8250",
						    PLAT8250_DEV_LEGACY);
	if (!serial8250_isa_devs) {
		ret = -ENOMEM;
2977
		goto unreg_uart_drv;
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	}

2980 2981 2982 2983
	ret = platform_device_add(serial8250_isa_devs);
	if (ret)
		goto put_dev;

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	serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);

2986 2987 2988
	ret = platform_driver_register(&serial8250_isa_driver);
	if (ret == 0)
		goto out;
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2990
	platform_device_del(serial8250_isa_devs);
2991 2992 2993
 put_dev:
	platform_device_put(serial8250_isa_devs);
 unreg_uart_drv:
2994 2995 2996
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
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	uart_unregister_driver(&serial8250_reg);
2998
#endif
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 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;

3014
	platform_driver_unregister(&serial8250_isa_driver);
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	platform_device_unregister(isa_dev);

3017 3018 3019
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
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	uart_unregister_driver(&serial8250_reg);
3021
#endif
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}

module_init(serial8250_init);
module_exit(serial8250_exit);

EXPORT_SYMBOL(serial8250_suspend_port);
EXPORT_SYMBOL(serial8250_resume_port);

MODULE_LICENSE("GPL");
3031
MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
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module_param(share_irqs, uint, 0644);
MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
	" (unsafe)");

3037 3038 3039
module_param(nr_uarts, uint, 0644);
MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");

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#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);