8250.c 85.5 KB
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/*
 *  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>
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#include <linux/ratelimit.h>
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#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 <linux/slab.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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static struct uart_driver serial8250_reg;

static int serial_index(struct uart_port *port)
{
	return (serial8250_reg.minor - 64) + port->line;
}

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static unsigned int skip_txen_test; /* force skip of txen test at init time */

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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

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#define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)


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/*
 * 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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	unsigned char		cur_iotype;	/* Running I/O type */
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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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};

struct irq_info {
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	struct			hlist_node node;
	int			irq;
	spinlock_t		lock;	/* Protects list not the hash */
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	struct list_head	*head;
};

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#define NR_IRQ_HASH		32	/* Can be adjusted later */
static struct hlist_head irq_lists[NR_IRQ_HASH];
static DEFINE_MUTEX(hash_mutex);	/* Used to walk the hash */
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/*
 * 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,
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		/* UART_CAP_EFR breaks billionon CF bluetooth card. */
		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
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	},
	[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,
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		.flags		= UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
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	},
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	[PORT_RM9000] = {
		.name		= "RM9000",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
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		.flags		= UART_CAP_FIFO,
	},
	[PORT_OCTEON] = {
		.name		= "OCTEON",
		.fifo_size	= 64,
		.tx_loadsz	= 64,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
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		.flags		= UART_CAP_FIFO,
	},
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	[PORT_AR7] = {
		.name		= "AR7",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
	},
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	[PORT_U6_16550A] = {
		.name		= "U6_16550A",
		.fifo_size	= 64,
		.tx_loadsz	= 64,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
	},
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	[PORT_TEGRA] = {
		.name		= "Tegra",
		.fifo_size	= 32,
		.tx_loadsz	= 8,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
				  UART_FCR_T_TRIG_01,
		.flags		= UART_CAP_FIFO | UART_CAP_RTOIE,
	},
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};

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#if defined(CONFIG_MIPS_ALCHEMY)
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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 */
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static inline int map_8250_in_reg(struct uart_port *p, int offset)
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{
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	if (p->iotype != UPIO_AU)
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		return offset;
	return au_io_in_map[offset];
}

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static inline int map_8250_out_reg(struct uart_port *p, int offset)
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{
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	if (p->iotype != UPIO_AU)
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		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
	};

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static inline int map_8250_in_reg(struct uart_port *p, int offset)
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{
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	if (p->iotype != UPIO_RM9000)
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		return offset;
	return regmap_in[offset];
}

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static inline int map_8250_out_reg(struct uart_port *p, int offset)
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{
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		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 hub6_serial_in(struct uart_port *p, int offset)
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{
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	offset = map_8250_in_reg(p, offset) << p->regshift;
	outb(p->hub6 - 1 + offset, p->iobase);
	return inb(p->iobase + 1);
}
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static void hub6_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	outb(p->hub6 - 1 + offset, p->iobase);
	outb(value, p->iobase + 1);
}
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static unsigned int mem_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return readb(p->membase + offset);
}
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static void mem_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	writeb(value, p->membase + offset);
}

static void mem32_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	writel(value, p->membase + offset);
}

static unsigned int mem32_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return readl(p->membase + offset);
}
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static unsigned int au_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return __raw_readl(p->membase + offset);
}

static void au_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	__raw_writel(value, p->membase + offset);
}
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static unsigned int tsi_serial_in(struct uart_port *p, int offset)
{
	unsigned int tmp;
	offset = map_8250_in_reg(p, offset) << p->regshift;
	if (offset == UART_IIR) {
		tmp = readl(p->membase + (UART_IIR & ~3));
		return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
	} else
		return readb(p->membase + offset);
}
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static void tsi_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	if (!((offset == UART_IER) && (value & UART_IER_UUE)))
		writeb(value, p->membase + offset);
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}

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/* Save the LCR value so it can be re-written when a Busy Detect IRQ occurs. */
static inline void dwapb_save_out_value(struct uart_port *p, int offset,
					int value)
{
	struct uart_8250_port *up =
		container_of(p, struct uart_8250_port, port);

	if (offset == UART_LCR)
		up->lcr = value;
}

/* Read the IER to ensure any interrupt is cleared before returning from ISR. */
static inline void dwapb_check_clear_ier(struct uart_port *p, int offset)
{
	if (offset == UART_TX || offset == UART_IER)
		p->serial_in(p, UART_IER);
}

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static void dwapb_serial_out(struct uart_port *p, int offset, int value)
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{
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	int save_offset = offset;
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	offset = map_8250_out_reg(p, offset) << p->regshift;
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	dwapb_save_out_value(p, save_offset, value);
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	writeb(value, p->membase + offset);
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	dwapb_check_clear_ier(p, save_offset);
}

static void dwapb32_serial_out(struct uart_port *p, int offset, int value)
{
	int save_offset = offset;
	offset = map_8250_out_reg(p, offset) << p->regshift;
	dwapb_save_out_value(p, save_offset, value);
	writel(value, p->membase + offset);
	dwapb_check_clear_ier(p, save_offset);
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}
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static unsigned int io_serial_in(struct uart_port *p, int offset)
{
	offset = map_8250_in_reg(p, offset) << p->regshift;
	return inb(p->iobase + offset);
}

static void io_serial_out(struct uart_port *p, int offset, int value)
{
	offset = map_8250_out_reg(p, offset) << p->regshift;
	outb(value, p->iobase + offset);
}

static void set_io_from_upio(struct uart_port *p)
{
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	struct uart_8250_port *up =
		container_of(p, struct uart_8250_port, port);
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	switch (p->iotype) {
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	case UPIO_HUB6:
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		p->serial_in = hub6_serial_in;
		p->serial_out = hub6_serial_out;
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		break;

	case UPIO_MEM:
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		p->serial_in = mem_serial_in;
		p->serial_out = mem_serial_out;
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		break;

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	case UPIO_RM9000:
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	case UPIO_MEM32:
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		p->serial_in = mem32_serial_in;
		p->serial_out = mem32_serial_out;
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		break;

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	case UPIO_AU:
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		p->serial_in = au_serial_in;
		p->serial_out = au_serial_out;
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		break;
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	case UPIO_TSI:
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		p->serial_in = tsi_serial_in;
		p->serial_out = tsi_serial_out;
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		break;
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	case UPIO_DWAPB:
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		p->serial_in = mem_serial_in;
		p->serial_out = dwapb_serial_out;
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		break;

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	case UPIO_DWAPB32:
		p->serial_in = mem32_serial_in;
		p->serial_out = dwapb32_serial_out;
		break;

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	default:
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		p->serial_in = io_serial_in;
		p->serial_out = io_serial_out;
		break;
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	}
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	/* Remember loaded iotype */
	up->cur_iotype = p->iotype;
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}

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static void
serial_out_sync(struct uart_8250_port *up, int offset, int value)
{
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	struct uart_port *p = &up->port;
	switch (p->iotype) {
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	case UPIO_MEM:
	case UPIO_MEM32:
	case UPIO_AU:
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	case UPIO_DWAPB:
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	case UPIO_DWAPB32:
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		p->serial_out(p, offset, value);
		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
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		break;
	default:
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		p->serial_out(p, offset, value);
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	}
}

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#define serial_in(up, offset)		\
	(up->port.serial_in(&(up)->port, (offset)))
#define serial_out(up, offset, value)	\
	(up->port.serial_out(&(up)->port, (offset), (value)))
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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_MIPS_ALCHEMY)
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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) {
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			serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
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			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) {
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			serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_B);
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			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)
{
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	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);
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	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
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	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);
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	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
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	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);
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	serial_outp(p, UART_LCR, UART_LCR_CONF_MODE_A);
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	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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 *
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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;
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	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
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	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;
885 886 887 888 889 890 891 892

		/*
		 * 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
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	 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html 
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	 */
	if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
		return 1;

	return 0;
}

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static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
{
	unsigned char status;

	status = serial_in(up, 0x04); /* EXCR2 */
#define PRESL(x) ((x) & 0x30)
	if (PRESL(status) == 0x10) {
		/* already in high speed mode */
		return 0;
	} else {
		status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
		status |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
		serial_outp(up, 0x04, status);
	}
	return 1;
}

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/*
 * 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.
	 */
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	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
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	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)
	 */
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	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
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	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) {
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			unsigned short quot;

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			serial_outp(up, UART_LCR, 0xE0);
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			quot = serial_dl_read(up);
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			quot <<= 3;

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			if (ns16550a_goto_highspeed(up))
				serial_dl_write(up, quot);
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			serial_outp(up, UART_LCR, 0);

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			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);
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	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_A);
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	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);
1121 1122 1123 1124 1125 1126 1127 1128 1129

	/*
	 * We distinguish between 16550A and U6 16550A by counting
	 * how many bytes are in the FIFO.
	 */
	if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
		up->port.type = PORT_U6_16550A;
		up->capabilities |= UART_CAP_AFE;
	}
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1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
}

/*
 * 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;

1148
	DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
1149
		       serial_index(&up->port), up->port.iobase, up->port.membase);
L
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1150 1151 1152 1153 1154 1155 1156 1157

	/*
	 * 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;
1158
	up->bugs = 0;
L
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1159 1160 1161 1162 1163

	if (!(up->port.flags & UPF_BUGGY_UART)) {
		/*
		 * Do a simple existence test first; if we fail this,
		 * there's no point trying anything else.
T
Thomas Koeller 已提交
1164
		 *
L
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1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178
		 * 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
1179 1180 1181 1182 1183
		/*
		 * 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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1184 1185 1186 1187
		serial_outp(up, UART_IER, 0x0F);
#ifdef __i386__
		outb(0, 0x080);
#endif
1188
		scratch3 = serial_inp(up, UART_IER) & 0x0f;
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1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
		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);

T
Thomas Koeller 已提交
1203
	/*
L
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1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
	 * 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
R
Russell King 已提交
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	 * out if it's 8250 or 16450, 16550, 16550A or later.  This
L
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1227 1228 1229 1230 1231
	 * 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.
	 */
1232
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
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1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271
	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
1272

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1273 1274 1275 1276 1277
	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",
1278 1279
		       serial_index(&up->port), up->capabilities,
		       uart_config[up->port.type].flags);
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1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
	}

	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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Alex Williamson 已提交
1298
	serial_in(up, UART_RX);
1299 1300 1301 1302
	if (up->capabilities & UART_CAP_UUE)
		serial_outp(up, UART_IER, UART_IER_UUE);
	else
		serial_outp(up, UART_IER, 0);
L
Linus Torvalds 已提交
1303

T
Thomas Koeller 已提交
1304
 out:
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1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
	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);
T
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1329

L
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1330 1331
	irqs = probe_irq_on();
	serial_outp(up, UART_MCR, 0);
A
Alan Cox 已提交
1332 1333
	udelay(10);
	if (up->port.flags & UPF_FOURPORT) {
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1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
		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);
A
Alan Cox 已提交
1346
	udelay(20);
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1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
	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;
}

1358 1359 1360 1361 1362 1363 1364 1365
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);
	}
}

1366
static void serial8250_stop_tx(struct uart_port *port)
L
Linus Torvalds 已提交
1367
{
1368 1369
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
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1370

1371
	__stop_tx(up);
L
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1372 1373

	/*
1374
	 * We really want to stop the transmitter from sending.
L
Linus Torvalds 已提交
1375
	 */
1376
	if (up->port.type == PORT_16C950) {
L
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1377 1378 1379 1380 1381
		up->acr |= UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

1382 1383
static void transmit_chars(struct uart_8250_port *up);

1384
static void serial8250_start_tx(struct uart_port *port)
L
Linus Torvalds 已提交
1385
{
1386 1387
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
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1388 1389 1390 1391

	if (!(up->ier & UART_IER_THRI)) {
		up->ier |= UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
1392

1393
		if (up->bugs & UART_BUG_TXEN) {
1394
			unsigned char lsr;
1395
			lsr = serial_in(up, UART_LSR);
1396
			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
T
Thomas Koeller 已提交
1397
			if ((up->port.type == PORT_RM9000) ?
1398 1399
				(lsr & UART_LSR_THRE) :
				(lsr & UART_LSR_TEMT))
1400 1401
				transmit_chars(up);
		}
L
Linus Torvalds 已提交
1402
	}
1403

L
Linus Torvalds 已提交
1404
	/*
1405
	 * Re-enable the transmitter if we disabled it.
L
Linus Torvalds 已提交
1406
	 */
1407
	if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
L
Linus Torvalds 已提交
1408 1409 1410 1411 1412 1413 1414
		up->acr &= ~UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

static void serial8250_stop_rx(struct uart_port *port)
{
1415 1416
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1417 1418 1419 1420 1421 1422 1423 1424

	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)
{
1425 1426
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1427

1428 1429 1430 1431
	/* no MSR capabilities */
	if (up->bugs & UART_BUG_NOMSR)
		return;

L
Linus Torvalds 已提交
1432 1433 1434 1435
	up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
}

1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
/*
 * Clear the Tegra rx fifo after a break
 *
 * FIXME: This needs to become a port specific callback once we have a
 * framework for this
 */
static void clear_rx_fifo(struct uart_8250_port *up)
{
	unsigned int status, tmout = 10000;
	do {
		status = serial_in(up, UART_LSR);
		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
			status = serial_in(up, UART_RX);
		else
			break;
		if (--tmout == 0)
			break;
		udelay(1);
	} while (1);
}

R
Russell King 已提交
1457
static void
1458
receive_chars(struct uart_8250_port *up, unsigned int *status)
L
Linus Torvalds 已提交
1459
{
A
Alan Cox 已提交
1460
	struct tty_struct *tty = up->port.state->port.tty;
L
Linus Torvalds 已提交
1461 1462 1463 1464 1465
	unsigned char ch, lsr = *status;
	int max_count = 256;
	char flag;

	do {
1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
		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;

L
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1478 1479 1480
		flag = TTY_NORMAL;
		up->port.icount.rx++;

1481 1482
		lsr |= up->lsr_saved_flags;
		up->lsr_saved_flags = 0;
L
Linus Torvalds 已提交
1483

1484
		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
L
Linus Torvalds 已提交
1485 1486 1487 1488 1489 1490
			/*
			 * For statistics only
			 */
			if (lsr & UART_LSR_BI) {
				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
				up->port.icount.brk++;
1491 1492 1493 1494 1495 1496 1497
				/*
				 * If tegra port then clear the rx fifo to
				 * accept another break/character.
				 */
				if (up->port.type == PORT_TEGRA)
					clear_rx_fifo(up);

L
Linus Torvalds 已提交
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513
				/*
				 * 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++;

			/*
1514
			 * Mask off conditions which should be ignored.
L
Linus Torvalds 已提交
1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525
			 */
			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;
		}
1526
		if (uart_handle_sysrq_char(&up->port, ch))
L
Linus Torvalds 已提交
1527
			goto ignore_char;
1528 1529 1530

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

A
Alan Cox 已提交
1531
ignore_char:
L
Linus Torvalds 已提交
1532
		lsr = serial_inp(up, UART_LSR);
1533
	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
L
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1534 1535 1536 1537 1538 1539
	spin_unlock(&up->port.lock);
	tty_flip_buffer_push(tty);
	spin_lock(&up->port.lock);
	*status = lsr;
}

R
Russell King 已提交
1540
static void transmit_chars(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1541
{
A
Alan Cox 已提交
1542
	struct circ_buf *xmit = &up->port.state->xmit;
L
Linus Torvalds 已提交
1543 1544 1545 1546 1547 1548 1549 1550
	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;
	}
1551 1552 1553 1554 1555
	if (uart_tx_stopped(&up->port)) {
		serial8250_stop_tx(&up->port);
		return;
	}
	if (uart_circ_empty(xmit)) {
1556
		__stop_tx(up);
L
Linus Torvalds 已提交
1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574
		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))
1575
		__stop_tx(up);
L
Linus Torvalds 已提交
1576 1577
}

1578
static unsigned int check_modem_status(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1579
{
1580 1581
	unsigned int status = serial_in(up, UART_MSR);

1582 1583
	status |= up->msr_saved_flags;
	up->msr_saved_flags = 0;
1584
	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
A
Alan Cox 已提交
1585
	    up->port.state != NULL) {
1586 1587 1588 1589 1590 1591 1592 1593 1594
		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);

1595
		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
1596
	}
L
Linus Torvalds 已提交
1597

1598
	return status;
L
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1599 1600 1601 1602 1603
}

/*
 * This handles the interrupt from one port.
 */
1604
static void serial8250_handle_port(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1605
{
1606
	unsigned int status;
1607
	unsigned long flags;
1608

1609
	spin_lock_irqsave(&up->port.lock, flags);
1610 1611

	status = serial_inp(up, UART_LSR);
L
Linus Torvalds 已提交
1612 1613 1614

	DEBUG_INTR("status = %x...", status);

1615
	if (status & (UART_LSR_DR | UART_LSR_BI))
1616
		receive_chars(up, &status);
L
Linus Torvalds 已提交
1617 1618 1619
	check_modem_status(up);
	if (status & UART_LSR_THRE)
		transmit_chars(up);
1620

1621
	spin_unlock_irqrestore(&up->port.lock, flags);
L
Linus Torvalds 已提交
1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637
}

/*
 * 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.
 */
1638
static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
L
Linus Torvalds 已提交
1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656
{
	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)) {
1657
			serial8250_handle_port(up);
L
Linus Torvalds 已提交
1658 1659 1660

			handled = 1;

M
Marc St-Jean 已提交
1661
			end = NULL;
1662 1663
		} else if ((up->port.iotype == UPIO_DWAPB ||
			    up->port.iotype == UPIO_DWAPB32) &&
M
Marc St-Jean 已提交
1664 1665
			  (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
			/* The DesignWare APB UART has an Busy Detect (0x07)
L
Lucas De Marchi 已提交
1666
			 * interrupt meaning an LCR write attempt occurred while the
M
Marc St-Jean 已提交
1667 1668 1669 1670 1671 1672 1673 1674
			 * 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;

L
Linus Torvalds 已提交
1675 1676 1677 1678 1679 1680 1681 1682
			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. */
1683 1684
			printk_ratelimited(KERN_ERR
				"serial8250: too much work for irq%d\n", irq);
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715
			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);
A
Alan Cox 已提交
1716 1717 1718 1719 1720
	/* List empty so throw away the hash node */
	if (i->head == NULL) {
		hlist_del(&i->node);
		kfree(i);
	}
L
Linus Torvalds 已提交
1721 1722 1723 1724
}

static int serial_link_irq_chain(struct uart_8250_port *up)
{
A
Alan Cox 已提交
1725 1726 1727
	struct hlist_head *h;
	struct hlist_node *n;
	struct irq_info *i;
1728
	int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
L
Linus Torvalds 已提交
1729

A
Alan Cox 已提交
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751
	mutex_lock(&hash_mutex);

	h = &irq_lists[up->port.irq % NR_IRQ_HASH];

	hlist_for_each(n, h) {
		i = hlist_entry(n, struct irq_info, node);
		if (i->irq == up->port.irq)
			break;
	}

	if (n == NULL) {
		i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
		if (i == NULL) {
			mutex_unlock(&hash_mutex);
			return -ENOMEM;
		}
		spin_lock_init(&i->lock);
		i->irq = up->port.irq;
		hlist_add_head(&i->node, h);
	}
	mutex_unlock(&hash_mutex);

L
Linus Torvalds 已提交
1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
	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);
1763
		irq_flags |= up->port.irqflags;
L
Linus Torvalds 已提交
1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774
		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)
{
A
Alan Cox 已提交
1775 1776 1777
	struct irq_info *i;
	struct hlist_node *n;
	struct hlist_head *h;
L
Linus Torvalds 已提交
1778

A
Alan Cox 已提交
1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789
	mutex_lock(&hash_mutex);

	h = &irq_lists[up->port.irq % NR_IRQ_HASH];

	hlist_for_each(n, h) {
		i = hlist_entry(n, struct irq_info, node);
		if (i->irq == up->port.irq)
			break;
	}

	BUG_ON(n == NULL);
L
Linus Torvalds 已提交
1790 1791 1792 1793 1794 1795
	BUG_ON(i->head == NULL);

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

	serial_do_unlink(i, up);
A
Alan Cox 已提交
1796
	mutex_unlock(&hash_mutex);
L
Linus Torvalds 已提交
1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
}

/*
 * 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);
1811
	if (!(iir & UART_IIR_NO_INT))
1812
		serial8250_handle_port(up);
1813
	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
A
Alex Williamson 已提交
1814 1815 1816 1817 1818
}

static void serial8250_backup_timeout(unsigned long data)
{
	struct uart_8250_port *up = (struct uart_8250_port *)data;
1819 1820
	unsigned int iir, ier = 0, lsr;
	unsigned long flags;
A
Alex Williamson 已提交
1821 1822 1823 1824 1825 1826 1827 1828 1829

	/*
	 * 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);
	}
L
Linus Torvalds 已提交
1830

A
Alex Williamson 已提交
1831 1832 1833 1834 1835 1836 1837 1838
	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.
	 */
1839 1840 1841 1842
	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
1843
	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
A
Alan Cox 已提交
1844
	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
1845
	    (lsr & UART_LSR_THRE)) {
A
Alex Williamson 已提交
1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856
		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
1857
	mod_timer(&up->timer,
1858
		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
L
Linus Torvalds 已提交
1859 1860 1861 1862
}

static unsigned int serial8250_tx_empty(struct uart_port *port)
{
1863 1864
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1865
	unsigned long flags;
1866
	unsigned int lsr;
L
Linus Torvalds 已提交
1867 1868

	spin_lock_irqsave(&up->port.lock, flags);
1869 1870
	lsr = serial_in(up, UART_LSR);
	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
L
Linus Torvalds 已提交
1871 1872
	spin_unlock_irqrestore(&up->port.lock, flags);

1873
	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
L
Linus Torvalds 已提交
1874 1875 1876 1877
}

static unsigned int serial8250_get_mctrl(struct uart_port *port)
{
1878 1879
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
1880
	unsigned int status;
L
Linus Torvalds 已提交
1881 1882
	unsigned int ret;

1883
	status = check_modem_status(up);
L
Linus Torvalds 已提交
1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898

	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)
{
1899 1900
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920
	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)
{
1921 1922
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933
	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);
}

A
Alex Williamson 已提交
1934 1935 1936
/*
 *	Wait for transmitter & holding register to empty
 */
1937
static void wait_for_xmitr(struct uart_8250_port *up, int bits)
A
Alex Williamson 已提交
1938 1939 1940 1941
{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
1942
	for (;;) {
A
Alex Williamson 已提交
1943 1944
		status = serial_in(up, UART_LSR);

1945
		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
A
Alex Williamson 已提交
1946

1947 1948
		if ((status & bits) == bits)
			break;
A
Alex Williamson 已提交
1949 1950 1951
		if (--tmout == 0)
			break;
		udelay(1);
1952
	}
A
Alex Williamson 已提交
1953 1954 1955

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
1956 1957 1958 1959 1960 1961
		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;
A
Alex Williamson 已提交
1962 1963 1964 1965 1966 1967
			udelay(1);
			touch_nmi_watchdog();
		}
	}
}

J
Jason Wessel 已提交
1968 1969 1970 1971 1972 1973 1974 1975
#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)
{
1976 1977
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
J
Jason Wessel 已提交
1978 1979
	unsigned char lsr = serial_inp(up, UART_LSR);

1980 1981
	if (!(lsr & UART_LSR_DR))
		return NO_POLL_CHAR;
J
Jason Wessel 已提交
1982 1983 1984 1985 1986 1987 1988 1989 1990

	return serial_inp(up, UART_RX);
}


static void serial8250_put_poll_char(struct uart_port *port,
			 unsigned char c)
{
	unsigned int ier;
1991 1992
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
J
Jason Wessel 已提交
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023

	/*
	 *	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 */

L
Linus Torvalds 已提交
2024 2025
static int serial8250_startup(struct uart_port *port)
{
2026 2027
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2028
	unsigned long flags;
2029
	unsigned char lsr, iir;
L
Linus Torvalds 已提交
2030 2031
	int retval;

O
Ondrej Puzman 已提交
2032 2033
	up->port.fifosize = uart_config[up->port.type].fifo_size;
	up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
L
Linus Torvalds 已提交
2034 2035 2036
	up->capabilities = uart_config[up->port.type].flags;
	up->mcr = 0;

A
Alan Cox 已提交
2037 2038 2039
	if (up->port.iotype != up->cur_iotype)
		set_io_from_upio(port);

L
Linus Torvalds 已提交
2040 2041 2042
	if (up->port.type == PORT_16C950) {
		/* Wake up and initialize UART */
		up->acr = 0;
2043
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062
		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.
A
Alexey Dobriyan 已提交
2063
	 * (they will be reenabled in set_termios())
L
Linus Torvalds 已提交
2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081
	 */
	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)) {
2082 2083
		printk(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
		       serial_index(&up->port));
L
Linus Torvalds 已提交
2084 2085 2086 2087 2088 2089 2090 2091 2092
		return -ENODEV;
	}

	/*
	 * For a XR16C850, we need to set the trigger levels
	 */
	if (up->port.type == PORT_16850) {
		unsigned char fctr;

2093
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2094 2095 2096 2097 2098 2099 2100 2101 2102 2103

		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);
	}

A
Alex Williamson 已提交
2104
	if (is_real_interrupt(up->port.irq)) {
2105
		unsigned char iir1;
A
Alex Williamson 已提交
2106 2107 2108 2109 2110 2111 2112 2113
		/*
		 * 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.
		 */
B
Borislav Petkov 已提交
2114
		spin_lock_irqsave(&up->port.lock, flags);
2115
		if (up->port.irqflags & IRQF_SHARED)
2116
			disable_irq_nosync(up->port.irq);
A
Alex Williamson 已提交
2117 2118 2119 2120

		wait_for_xmitr(up, UART_LSR_THRE);
		serial_out_sync(up, UART_IER, UART_IER_THRI);
		udelay(1); /* allow THRE to set */
2121
		iir1 = serial_in(up, UART_IIR);
A
Alex Williamson 已提交
2122 2123 2124 2125 2126 2127
		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);

2128
		if (up->port.irqflags & IRQF_SHARED)
2129
			enable_irq(up->port.irq);
B
Borislav Petkov 已提交
2130
		spin_unlock_irqrestore(&up->port.lock, flags);
A
Alex Williamson 已提交
2131 2132 2133 2134 2135

		/*
		 * If the interrupt is not reasserted, setup a timer to
		 * kick the UART on a regular basis.
		 */
2136
		if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
2137
			up->bugs |= UART_BUG_THRE;
2138 2139
			pr_debug("ttyS%d - using backup timer\n",
				 serial_index(port));
A
Alex Williamson 已提交
2140 2141 2142
		}
	}

2143 2144 2145 2146 2147 2148 2149 2150
	/*
	 * 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 +
2151
			uart_poll_timeout(port) + HZ / 5);
2152 2153
	}

L
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2154 2155 2156 2157 2158 2159 2160
	/*
	 * 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;
2161
		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
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2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184
	} 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);
2185

2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196
	/* Serial over Lan (SoL) hack:
	   Intel 8257x Gigabit ethernet chips have a
	   16550 emulation, to be used for Serial Over Lan.
	   Those chips take a longer time than a normal
	   serial device to signalize that a transmission
	   data was queued. Due to that, the above test generally
	   fails. One solution would be to delay the reading of
	   iir. However, this is not reliable, since the timeout
	   is variable. So, let's just don't test if we receive
	   TX irq. This way, we'll never enable UART_BUG_TXEN.
	 */
2197
	if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST)
2198 2199
		goto dont_test_tx_en;

2200 2201 2202 2203 2204 2205 2206 2207 2208 2209
	/*
	 * 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) {
2210 2211
		if (!(up->bugs & UART_BUG_TXEN)) {
			up->bugs |= UART_BUG_TXEN;
2212
			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2213
				 serial_index(port));
2214 2215
		}
	} else {
2216
		up->bugs &= ~UART_BUG_TXEN;
2217 2218
	}

2219
dont_test_tx_en:
L
Linus Torvalds 已提交
2220 2221
	spin_unlock_irqrestore(&up->port.lock, flags);

2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233
	/*
	 * 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;

L
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2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256
	/*
	 * 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)
{
2257 2258
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296
	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);

A
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2297 2298 2299
	del_timer_sync(&up->timer);
	up->timer.function = serial8250_timeout;
	if (is_real_interrupt(up->port.irq))
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Linus Torvalds 已提交
2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322
		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;
}

2323 2324 2325
void
serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
		          struct ktermios *old)
L
Linus Torvalds 已提交
2326
{
2327 2328
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2329 2330 2331 2332 2333 2334
	unsigned char cval, fcr = 0;
	unsigned long flags;
	unsigned int baud, quot;

	switch (termios->c_cflag & CSIZE) {
	case CS5:
2335
		cval = UART_LCR_WLEN5;
L
Linus Torvalds 已提交
2336 2337
		break;
	case CS6:
2338
		cval = UART_LCR_WLEN6;
L
Linus Torvalds 已提交
2339 2340
		break;
	case CS7:
2341
		cval = UART_LCR_WLEN7;
L
Linus Torvalds 已提交
2342 2343 2344
		break;
	default:
	case CS8:
2345
		cval = UART_LCR_WLEN8;
L
Linus Torvalds 已提交
2346 2347 2348 2349
		break;
	}

	if (termios->c_cflag & CSTOPB)
2350
		cval |= UART_LCR_STOP;
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Linus Torvalds 已提交
2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362
	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.
	 */
2363 2364 2365
	baud = uart_get_baud_rate(port, termios, old,
				  port->uartclk / 16 / 0xffff,
				  port->uartclk / 16);
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2366 2367 2368
	quot = serial8250_get_divisor(port, baud);

	/*
2369
	 * Oxford Semi 952 rev B workaround
L
Linus Torvalds 已提交
2370
	 */
2371
	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
A
Alan Cox 已提交
2372
		quot++;
L
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2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436

	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
	 */
2437
	up->ier &= ~UART_IER_MSI;
2438 2439
	if (!(up->bugs & UART_BUG_NOMSR) &&
			UART_ENABLE_MS(&up->port, termios->c_cflag))
L
Linus Torvalds 已提交
2440 2441
		up->ier |= UART_IER_MSI;
	if (up->capabilities & UART_CAP_UUE)
2442 2443 2444
		up->ier |= UART_IER_UUE;
	if (up->capabilities & UART_CAP_RTOIE)
		up->ier |= UART_IER_RTOIE;
L
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2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457

	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;

2458
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2459 2460 2461
		serial_outp(up, UART_EFR, efr);
	}

2462
#ifdef CONFIG_ARCH_OMAP
2463
	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
2464
	if (cpu_is_omap1510() && is_omap_port(up)) {
2465 2466 2467 2468 2469 2470 2471 2472
		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

L
Linus Torvalds 已提交
2473 2474 2475 2476 2477 2478 2479
	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 */
	}

2480
	serial_dl_write(up, quot);
L
Linus Torvalds 已提交
2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499

	/*
	 * 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);
A
Alan Cox 已提交
2500 2501 2502
	/* Don't rewrite B0 */
	if (tty_termios_baud_rate(termios))
		tty_termios_encode_baud_rate(termios, baud, baud);
L
Linus Torvalds 已提交
2503
}
2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514
EXPORT_SYMBOL(serial8250_do_set_termios);

static void
serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
		       struct ktermios *old)
{
	if (port->set_termios)
		port->set_termios(port, termios, old);
	else
		serial8250_do_set_termios(port, termios, old);
}
L
Linus Torvalds 已提交
2515

2516
static void
A
Arnd Bergmann 已提交
2517
serial8250_set_ldisc(struct uart_port *port, int new)
2518
{
A
Arnd Bergmann 已提交
2519
	if (new == N_PPS) {
2520 2521 2522 2523 2524 2525
		port->flags |= UPF_HARDPPS_CD;
		serial8250_enable_ms(port);
	} else
		port->flags &= ~UPF_HARDPPS_CD;
}

2526 2527 2528

void serial8250_do_pm(struct uart_port *port, unsigned int state,
		      unsigned int oldstate)
L
Linus Torvalds 已提交
2529
{
2530 2531
	struct uart_8250_port *p =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2532 2533

	serial8250_set_sleep(p, state != 0);
2534 2535
}
EXPORT_SYMBOL(serial8250_do_pm);
L
Linus Torvalds 已提交
2536

2537 2538 2539 2540 2541 2542 2543 2544
static void
serial8250_pm(struct uart_port *port, unsigned int state,
	      unsigned int oldstate)
{
	if (port->pm)
		port->pm(port, state, oldstate);
	else
		serial8250_do_pm(port, state, oldstate);
L
Linus Torvalds 已提交
2545 2546
}

2547 2548 2549
static unsigned int serial8250_port_size(struct uart_8250_port *pt)
{
	if (pt->port.iotype == UPIO_AU)
2550
		return 0x1000;
2551 2552 2553 2554 2555 2556 2557
#ifdef CONFIG_ARCH_OMAP
	if (is_omap_port(pt))
		return 0x16 << pt->port.regshift;
#endif
	return 8 << pt->port.regshift;
}

L
Linus Torvalds 已提交
2558 2559 2560 2561 2562
/*
 * Resource handling.
 */
static int serial8250_request_std_resource(struct uart_8250_port *up)
{
2563
	unsigned int size = serial8250_port_size(up);
L
Linus Torvalds 已提交
2564 2565 2566
	int ret = 0;

	switch (up->port.iotype) {
2567
	case UPIO_AU:
2568 2569
	case UPIO_TSI:
	case UPIO_MEM32:
L
Linus Torvalds 已提交
2570
	case UPIO_MEM:
M
Marc St-Jean 已提交
2571
	case UPIO_DWAPB:
2572
	case UPIO_DWAPB32:
L
Linus Torvalds 已提交
2573 2574 2575 2576 2577 2578 2579 2580 2581
		if (!up->port.mapbase)
			break;

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

		if (up->port.flags & UPF_IOREMAP) {
2582 2583
			up->port.membase = ioremap_nocache(up->port.mapbase,
									size);
L
Linus Torvalds 已提交
2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601
			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)
{
2602
	unsigned int size = serial8250_port_size(up);
L
Linus Torvalds 已提交
2603 2604

	switch (up->port.iotype) {
2605
	case UPIO_AU:
2606 2607
	case UPIO_TSI:
	case UPIO_MEM32:
L
Linus Torvalds 已提交
2608
	case UPIO_MEM:
M
Marc St-Jean 已提交
2609
	case UPIO_DWAPB:
2610
	case UPIO_DWAPB32:
L
Linus Torvalds 已提交
2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
		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;
2633
	int ret = -EINVAL;
L
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2634 2635 2636 2637 2638

	switch (up->port.iotype) {
	case UPIO_HUB6:
	case UPIO_PORT:
		start += up->port.iobase;
2639 2640 2641
		if (request_region(start, size, "serial-rsa"))
			ret = 0;
		else
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Linus Torvalds 已提交
2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663
			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)
{
2664 2665
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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2666 2667 2668 2669 2670 2671 2672 2673

	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)
{
2674 2675
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689
	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)
{
2690 2691
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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	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;

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	if (up->port.iotype != up->cur_iotype)
		set_io_from_upio(port);

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	if (flags & UART_CONFIG_TYPE)
		autoconfig(up, probeflags);
2712 2713 2714 2715 2716

	/* 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;

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	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)
{
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	if (ser->irq >= nr_irqs || ser->irq < 0 ||
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	    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,
2759
	.set_ldisc	= serial8250_set_ldisc,
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	.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];

2774 2775 2776 2777 2778 2779 2780 2781 2782 2783
static void (*serial8250_isa_config)(int port, struct uart_port *up,
	unsigned short *capabilities);

void serial8250_set_isa_configurator(
	void (*v)(int port, struct uart_port *up, unsigned short *capabilities))
{
	serial8250_isa_config = v;
}
EXPORT_SYMBOL(serial8250_set_isa_configurator);

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static void __init serial8250_isa_init_ports(void)
{
	struct uart_8250_port *up;
	static int first = 1;
2788
	int i, irqflag = 0;
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	if (!first)
		return;
	first = 0;

2794
	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;
	}

2812 2813 2814
	if (share_irqs)
		irqflag = IRQF_SHARED;

2815
	for (i = 0, up = serial8250_ports;
2816
	     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);
2820
		up->port.irqflags = old_serial_port[i].irqflags;
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		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;
2827
		set_io_from_upio(&up->port);
2828
		up->port.irqflags |= irqflag;
2829 2830 2831
		if (serial8250_isa_config != NULL)
			serial8250_isa_config(i, &up->port, &up->capabilities);

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	}
}

2835 2836 2837 2838 2839 2840 2841 2842 2843
static void
serial8250_init_fixed_type_port(struct uart_8250_port *up, unsigned int type)
{
	up->port.type = type;
	up->port.fifosize = uart_config[type].fifo_size;
	up->capabilities = uart_config[type].flags;
	up->tx_loadsz = uart_config[type].tx_loadsz;
}

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

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	for (i = 0; i < nr_uarts; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];
		up->cur_iotype = 0xFF;
	}

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	serial8250_isa_init_ports();

2856
	for (i = 0; i < nr_uarts; i++) {
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		struct uart_8250_port *up = &serial8250_ports[i];

		up->port.dev = dev;
2860 2861 2862 2863

		if (up->port.flags & UPF_FIXED_TYPE)
			serial8250_init_fixed_type_port(up, up->port.type);

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

#ifdef CONFIG_SERIAL_8250_CONSOLE

2870 2871
static void serial8250_console_putchar(struct uart_port *port, int ch)
{
2872 2873
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
2874 2875 2876 2877 2878

	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];
2889
	unsigned long flags;
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	unsigned int ier;
2891
	int locked = 1;
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2893 2894
	touch_nmi_watchdog();

2895 2896 2897 2898 2899 2900
	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);
2901
	} else
2902
		spin_lock(&up->port.lock);
2903

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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);

2914
	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);
2921
	serial_out(up, UART_IER, ier);
2922

2923 2924 2925 2926 2927 2928 2929 2930 2931 2932
	/*
	 *	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);

2933
	if (locked)
2934 2935
		spin_unlock(&up->port.lock);
	local_irq_restore(flags);
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}

2938
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.
	 */
2951
	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);
}

2963
static int serial8250_console_early_setup(void)
2964 2965 2966 2967
{
	return serial8250_find_port_for_earlycon();
}

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static struct console serial8250_console = {
	.name		= "ttyS",
	.write		= serial8250_console_write,
	.device		= uart_console_device,
	.setup		= serial8250_console_setup,
2973
	.early_setup	= serial8250_console_early_setup,
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	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
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	.index		= -1,
	.data		= &serial8250_reg,
};

static int __init serial8250_console_init(void)
{
2981 2982 2983
	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);

2990
int serial8250_find_port(struct uart_port *p)
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{
	int line;
	struct uart_port *port;

2995
	for (line = 0; line < nr_uarts; line++) {
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		port = &serial8250_ports[line].port;
2997
		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,
};

3017 3018 3019 3020 3021 3022
/*
 * 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)
{
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	struct uart_port *p;

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	if (port->line >= ARRAY_SIZE(serial8250_ports))
		return -ENODEV;

	serial8250_isa_init_ports();
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	p = &serial8250_ports[port->line].port;
	p->iobase       = port->iobase;
	p->membase      = port->membase;
	p->irq          = port->irq;
3035
	p->irqflags     = port->irqflags;
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	p->uartclk      = port->uartclk;
	p->fifosize     = port->fifosize;
	p->regshift     = port->regshift;
	p->iotype       = port->iotype;
	p->flags        = port->flags;
	p->mapbase      = port->mapbase;
	p->private_data = port->private_data;
3043 3044
	p->type		= port->type;
	p->line		= port->line;
3045 3046 3047 3048 3049 3050 3051

	set_io_from_upio(p);
	if (port->serial_in)
		p->serial_in = port->serial_in;
	if (port->serial_out)
		p->serial_out = port->serial_out;

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	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)
{
3074 3075 3076 3077 3078 3079
	struct uart_8250_port *up = &serial8250_ports[line];

	if (up->capabilities & UART_NATSEMI) {
		/* Ensure it's still in high speed mode */
		serial_outp(up, UART_LCR, 0xE0);

3080
		ns16550a_goto_highspeed(up);
3081 3082

		serial_outp(up, UART_LCR, 0);
3083
		up->port.uartclk = 921600*16;
3084 3085
	}
	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.
 */
3093
static int __devinit serial8250_probe(struct platform_device *dev)
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{
3095
	struct plat_serial8250_port *p = dev->dev.platform_data;
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	struct uart_port port;
3097
	int ret, i, irqflag = 0;
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	memset(&port, 0, sizeof(struct uart_port));

3101 3102 3103
	if (share_irqs)
		irqflag = IRQF_SHARED;

3104
	for (i = 0; p && p->flags != 0; p++, i++) {
3105 3106 3107
		port.iobase		= p->iobase;
		port.membase		= p->membase;
		port.irq		= p->irq;
3108
		port.irqflags		= p->irqflags;
3109 3110 3111 3112 3113 3114 3115
		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;
3116
		port.type		= p->type;
3117 3118
		port.serial_in		= p->serial_in;
		port.serial_out		= p->serial_out;
3119
		port.set_termios	= p->set_termios;
3120
		port.pm			= p->pm;
3121
		port.dev		= &dev->dev;
3122
		port.irqflags		|= irqflag;
3123 3124
		ret = serial8250_register_port(&port);
		if (ret < 0) {
3125
			dev_err(&dev->dev, "unable to register port at index %d "
3126 3127 3128
				"(IO%lx MEM%llx IRQ%d): %d\n", i,
				p->iobase, (unsigned long long)p->mapbase,
				p->irq, ret);
3129
		}
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	}
	return 0;
}

/*
 * Remove serial ports registered against a platform device.
 */
3137
static int __devexit serial8250_remove(struct platform_device *dev)
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{
	int i;

3141
	for (i = 0; i < nr_uarts; i++) {
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		struct uart_8250_port *up = &serial8250_ports[i];

3144
		if (up->port.dev == &dev->dev)
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			serial8250_unregister_port(i);
	}
	return 0;
}

3150
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];

3157
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
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			uart_suspend_port(&serial8250_reg, &up->port);
	}

	return 0;
}

3164
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];

3171
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3172
			serial8250_resume_port(i);
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	}

	return 0;
}

3178
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,
3183 3184
	.driver		= {
		.name	= "serial8250",
3185
		.owner	= THIS_MODULE,
3186
	},
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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.
 */
3200
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.
	 */
3209
	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).
	 */
3218
	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.
	 */
3227
	for (i = 0; i < nr_uarts; i++)
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3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254
		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;

3255
	mutex_lock(&serial_mutex);
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3256 3257 3258 3259 3260

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

3261 3262 3263
		uart->port.iobase       = port->iobase;
		uart->port.membase      = port->membase;
		uart->port.irq          = port->irq;
3264
		uart->port.irqflags     = port->irqflags;
3265 3266 3267 3268 3269 3270 3271
		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;
3274

3275 3276
		if (port->flags & UPF_FIXED_TYPE)
			serial8250_init_fixed_type_port(uart, port->type);
3277

3278 3279 3280 3281 3282 3283
		set_io_from_upio(&uart->port);
		/* Possibly override default I/O functions.  */
		if (port->serial_in)
			uart->port.serial_in = port->serial_in;
		if (port->serial_out)
			uart->port.serial_out = port->serial_out;
3284 3285 3286
		/*  Possibly override set_termios call */
		if (port->set_termios)
			uart->port.set_termios = port->set_termios;
3287 3288
		if (port->pm)
			uart->port.pm = port->pm;
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3290 3291 3292 3293
		if (serial8250_isa_config != NULL)
			serial8250_isa_config(0, &uart->port,
					&uart->capabilities);

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		ret = uart_add_one_port(&serial8250_reg, &uart->port);
		if (ret == 0)
			ret = uart->port.line;
	}
3298
	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];

3315
	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;
	}
3325
	mutex_unlock(&serial_mutex);
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}
EXPORT_SYMBOL(serial8250_unregister_port);

static int __init serial8250_init(void)
{
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	int ret;
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3333 3334 3335
	if (nr_uarts > UART_NR)
		nr_uarts = UART_NR;

3336
	printk(KERN_INFO "Serial: 8250/16550 driver, "
3337
		"%d ports, IRQ sharing %sabled\n", nr_uarts,
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		share_irqs ? "en" : "dis");

3340 3341 3342 3343
#ifdef CONFIG_SPARC
	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
#else
	serial8250_reg.nr = UART_NR;
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3344
	ret = uart_register_driver(&serial8250_reg);
3345
#endif
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3346 3347 3348
	if (ret)
		goto out;

3349 3350 3351 3352
	serial8250_isa_devs = platform_device_alloc("serial8250",
						    PLAT8250_DEV_LEGACY);
	if (!serial8250_isa_devs) {
		ret = -ENOMEM;
3353
		goto unreg_uart_drv;
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3354 3355
	}

3356 3357 3358 3359
	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);

3362 3363 3364
	ret = platform_driver_register(&serial8250_isa_driver);
	if (ret == 0)
		goto out;
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3365

3366
	platform_device_del(serial8250_isa_devs);
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3367
put_dev:
3368
	platform_device_put(serial8250_isa_devs);
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3369
unreg_uart_drv:
3370 3371 3372
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
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3373
	uart_unregister_driver(&serial8250_reg);
3374
#endif
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3375
out:
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3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389
	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;

3390
	platform_driver_unregister(&serial8250_isa_driver);
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3391 3392
	platform_device_unregister(isa_dev);

3393 3394 3395
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
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3396
	uart_unregister_driver(&serial8250_reg);
3397
#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");
3407
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)");

3413 3414 3415
module_param(nr_uarts, uint, 0644);
MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");

3416 3417 3418
module_param(skip_txen_test, uint, 0644);
MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");

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3419 3420 3421 3422 3423
#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);