8250.c 84.6 KB
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/*
 *  linux/drivers/char/8250.c
 *
 *  Driver for 8250/16550-type serial ports
 *
 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 *
 *  Copyright (C) 2001 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * A note about mapbase / membase
 *
 *  mapbase is the physical address of the IO port.
 *  membase is an 'ioremapped' cookie.
 */

#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/tty.h>
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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,
		.flags		= UART_CAP_FIFO | UART_CAP_UUE,
	},
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	[PORT_RM9000] = {
		.name		= "RM9000",
		.fifo_size	= 16,
		.tx_loadsz	= 16,
		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
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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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};

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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;
879 880 881 882 883 884 885 886

		/*
		 * 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
949
	 * 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.
	 */
992
	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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1042
			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);
1115 1116 1117 1118 1119 1120 1121 1122 1123

	/*
	 * 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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1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
}

/*
 * 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;

1142
	DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
1143
		       serial_index(&up->port), up->port.iobase, up->port.membase);
L
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1144 1145 1146 1147 1148 1149 1150 1151

	/*
	 * 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;
1152
	up->bugs = 0;
L
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1153 1154 1155 1156 1157

	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
1158
		 *
L
Linus Torvalds 已提交
1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172
		 * 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
1173 1174 1175 1176 1177
		/*
		 * 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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1178 1179 1180 1181
		serial_outp(up, UART_IER, 0x0F);
#ifdef __i386__
		outb(0, 0x080);
#endif
1182
		scratch3 = serial_inp(up, UART_IER) & 0x0f;
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1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196
		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
1197
	/*
L
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1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219
	 * 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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1221 1222 1223 1224 1225
	 * 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.
	 */
1226
	serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
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1227 1228 1229 1230 1231 1232 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
	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
1266

L
Linus Torvalds 已提交
1267 1268 1269 1270 1271
	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",
1272 1273
		       serial_index(&up->port), up->capabilities,
		       uart_config[up->port.type].flags);
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Linus Torvalds 已提交
1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291
	}

	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
1292
	serial_in(up, UART_RX);
1293 1294 1295 1296
	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
1297

T
Thomas Koeller 已提交
1298
 out:
L
Linus Torvalds 已提交
1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
	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
Thomas Koeller 已提交
1323

L
Linus Torvalds 已提交
1324 1325
	irqs = probe_irq_on();
	serial_outp(up, UART_MCR, 0);
A
Alan Cox 已提交
1326 1327
	udelay(10);
	if (up->port.flags & UPF_FOURPORT) {
L
Linus Torvalds 已提交
1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
		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
1340
	udelay(20);
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Linus Torvalds 已提交
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351
	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;
}

1352 1353 1354 1355 1356 1357 1358 1359
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);
	}
}

1360
static void serial8250_stop_tx(struct uart_port *port)
L
Linus Torvalds 已提交
1361
{
1362 1363
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1364

1365
	__stop_tx(up);
L
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1366 1367

	/*
1368
	 * We really want to stop the transmitter from sending.
L
Linus Torvalds 已提交
1369
	 */
1370
	if (up->port.type == PORT_16C950) {
L
Linus Torvalds 已提交
1371 1372 1373 1374 1375
		up->acr |= UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

1376 1377
static void transmit_chars(struct uart_8250_port *up);

1378
static void serial8250_start_tx(struct uart_port *port)
L
Linus Torvalds 已提交
1379
{
1380 1381
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1382 1383 1384 1385

	if (!(up->ier & UART_IER_THRI)) {
		up->ier |= UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
1386

1387
		if (up->bugs & UART_BUG_TXEN) {
1388
			unsigned char lsr;
1389
			lsr = serial_in(up, UART_LSR);
1390
			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
T
Thomas Koeller 已提交
1391
			if ((up->port.type == PORT_RM9000) ?
1392 1393
				(lsr & UART_LSR_THRE) :
				(lsr & UART_LSR_TEMT))
1394 1395
				transmit_chars(up);
		}
L
Linus Torvalds 已提交
1396
	}
1397

L
Linus Torvalds 已提交
1398
	/*
1399
	 * Re-enable the transmitter if we disabled it.
L
Linus Torvalds 已提交
1400
	 */
1401
	if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
L
Linus Torvalds 已提交
1402 1403 1404 1405 1406 1407 1408
		up->acr &= ~UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

static void serial8250_stop_rx(struct uart_port *port)
{
1409 1410
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1411 1412 1413 1414 1415 1416 1417 1418

	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)
{
1419 1420
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1421

1422 1423 1424 1425
	/* no MSR capabilities */
	if (up->bugs & UART_BUG_NOMSR)
		return;

L
Linus Torvalds 已提交
1426 1427 1428 1429
	up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
}

R
Russell King 已提交
1430
static void
1431
receive_chars(struct uart_8250_port *up, unsigned int *status)
L
Linus Torvalds 已提交
1432
{
A
Alan Cox 已提交
1433
	struct tty_struct *tty = up->port.state->port.tty;
L
Linus Torvalds 已提交
1434 1435 1436 1437 1438
	unsigned char ch, lsr = *status;
	int max_count = 256;
	char flag;

	do {
1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450
		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
Linus Torvalds 已提交
1451 1452 1453
		flag = TTY_NORMAL;
		up->port.icount.rx++;

1454 1455
		lsr |= up->lsr_saved_flags;
		up->lsr_saved_flags = 0;
L
Linus Torvalds 已提交
1456

1457
		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
L
Linus Torvalds 已提交
1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479
			/*
			 * For statistics only
			 */
			if (lsr & UART_LSR_BI) {
				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
				up->port.icount.brk++;
				/*
				 * We do the SysRQ and SAK checking
				 * here because otherwise the break
				 * may get masked by ignore_status_mask
				 * or read_status_mask.
				 */
				if (uart_handle_break(&up->port))
					goto ignore_char;
			} else if (lsr & UART_LSR_PE)
				up->port.icount.parity++;
			else if (lsr & UART_LSR_FE)
				up->port.icount.frame++;
			if (lsr & UART_LSR_OE)
				up->port.icount.overrun++;

			/*
1480
			 * Mask off conditions which should be ignored.
L
Linus Torvalds 已提交
1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491
			 */
			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;
		}
1492
		if (uart_handle_sysrq_char(&up->port, ch))
L
Linus Torvalds 已提交
1493
			goto ignore_char;
1494 1495 1496

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

A
Alan Cox 已提交
1497
ignore_char:
L
Linus Torvalds 已提交
1498
		lsr = serial_inp(up, UART_LSR);
1499
	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
L
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1500 1501 1502 1503 1504 1505
	spin_unlock(&up->port.lock);
	tty_flip_buffer_push(tty);
	spin_lock(&up->port.lock);
	*status = lsr;
}

R
Russell King 已提交
1506
static void transmit_chars(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1507
{
A
Alan Cox 已提交
1508
	struct circ_buf *xmit = &up->port.state->xmit;
L
Linus Torvalds 已提交
1509 1510 1511 1512 1513 1514 1515 1516
	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;
	}
1517 1518 1519 1520 1521
	if (uart_tx_stopped(&up->port)) {
		serial8250_stop_tx(&up->port);
		return;
	}
	if (uart_circ_empty(xmit)) {
1522
		__stop_tx(up);
L
Linus Torvalds 已提交
1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540
		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))
1541
		__stop_tx(up);
L
Linus Torvalds 已提交
1542 1543
}

1544
static unsigned int check_modem_status(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1545
{
1546 1547
	unsigned int status = serial_in(up, UART_MSR);

1548 1549
	status |= up->msr_saved_flags;
	up->msr_saved_flags = 0;
1550
	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
A
Alan Cox 已提交
1551
	    up->port.state != NULL) {
1552 1553 1554 1555 1556 1557 1558 1559 1560
		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);

1561
		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
1562
	}
L
Linus Torvalds 已提交
1563

1564
	return status;
L
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1565 1566 1567 1568 1569
}

/*
 * This handles the interrupt from one port.
 */
1570
static void serial8250_handle_port(struct uart_8250_port *up)
L
Linus Torvalds 已提交
1571
{
1572
	unsigned int status;
1573
	unsigned long flags;
1574

1575
	spin_lock_irqsave(&up->port.lock, flags);
1576 1577

	status = serial_inp(up, UART_LSR);
L
Linus Torvalds 已提交
1578 1579 1580

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

1581
	if (status & (UART_LSR_DR | UART_LSR_BI))
1582
		receive_chars(up, &status);
L
Linus Torvalds 已提交
1583 1584 1585
	check_modem_status(up);
	if (status & UART_LSR_THRE)
		transmit_chars(up);
1586

1587
	spin_unlock_irqrestore(&up->port.lock, flags);
L
Linus Torvalds 已提交
1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603
}

/*
 * 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.
 */
1604
static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
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Linus Torvalds 已提交
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{
	struct irq_info *i = dev_id;
	struct list_head *l, *end = NULL;
	int pass_counter = 0, handled = 0;

	DEBUG_INTR("serial8250_interrupt(%d)...", irq);

	spin_lock(&i->lock);

	l = i->head;
	do {
		struct uart_8250_port *up;
		unsigned int iir;

		up = list_entry(l, struct uart_8250_port, list);

		iir = serial_in(up, UART_IIR);
		if (!(iir & UART_IIR_NO_INT)) {
1623
			serial8250_handle_port(up);
L
Linus Torvalds 已提交
1624 1625 1626

			handled = 1;

M
Marc St-Jean 已提交
1627
			end = NULL;
1628 1629
		} else if ((up->port.iotype == UPIO_DWAPB ||
			    up->port.iotype == UPIO_DWAPB32) &&
M
Marc St-Jean 已提交
1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640
			  (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
			/* The DesignWare APB UART has an Busy Detect (0x07)
			 * interrupt meaning an LCR write attempt occured while the
			 * UART was busy. The interrupt must be cleared by reading
			 * the UART status register (USR) and the LCR re-written. */
			unsigned int status;
			status = *(volatile u32 *)up->port.private_data;
			serial_out(up, UART_LCR, up->lcr);

			handled = 1;

L
Linus Torvalds 已提交
1641 1642 1643 1644 1645 1646 1647 1648
			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. */
1649 1650
			printk_ratelimited(KERN_ERR
				"serial8250: too much work for irq%d\n", irq);
L
Linus Torvalds 已提交
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681
			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
1682 1683 1684 1685 1686
	/* List empty so throw away the hash node */
	if (i->head == NULL) {
		hlist_del(&i->node);
		kfree(i);
	}
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Linus Torvalds 已提交
1687 1688 1689 1690
}

static int serial_link_irq_chain(struct uart_8250_port *up)
{
A
Alan Cox 已提交
1691 1692 1693
	struct hlist_head *h;
	struct hlist_node *n;
	struct irq_info *i;
1694
	int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
L
Linus Torvalds 已提交
1695

A
Alan Cox 已提交
1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717
	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
1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728
	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);
1729
		irq_flags |= up->port.irqflags;
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Linus Torvalds 已提交
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740
		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
1741 1742 1743
	struct irq_info *i;
	struct hlist_node *n;
	struct hlist_head *h;
L
Linus Torvalds 已提交
1744

A
Alan Cox 已提交
1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755
	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
1756 1757 1758 1759 1760 1761
	BUG_ON(i->head == NULL);

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

	serial_do_unlink(i, up);
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Alan Cox 已提交
1762
	mutex_unlock(&hash_mutex);
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Linus Torvalds 已提交
1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776
}

/*
 * 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);
1777
	if (!(iir & UART_IIR_NO_INT))
1778
		serial8250_handle_port(up);
1779
	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
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Alex Williamson 已提交
1780 1781 1782 1783 1784
}

static void serial8250_backup_timeout(unsigned long data)
{
	struct uart_8250_port *up = (struct uart_8250_port *)data;
1785 1786
	unsigned int iir, ier = 0, lsr;
	unsigned long flags;
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Alex Williamson 已提交
1787 1788 1789 1790 1791 1792 1793 1794 1795

	/*
	 * Must disable interrupts or else we risk racing with the interrupt
	 * based handler.
	 */
	if (is_real_interrupt(up->port.irq)) {
		ier = serial_in(up, UART_IER);
		serial_out(up, UART_IER, 0);
	}
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Linus Torvalds 已提交
1796

A
Alex Williamson 已提交
1797 1798 1799 1800 1801 1802 1803 1804
	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.
	 */
1805 1806 1807 1808
	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
1809
	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
A
Alan Cox 已提交
1810
	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
1811
	    (lsr & UART_LSR_THRE)) {
A
Alex Williamson 已提交
1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822
		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
1823
	mod_timer(&up->timer,
1824
		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
L
Linus Torvalds 已提交
1825 1826 1827 1828
}

static unsigned int serial8250_tx_empty(struct uart_port *port)
{
1829 1830
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1831
	unsigned long flags;
1832
	unsigned int lsr;
L
Linus Torvalds 已提交
1833 1834

	spin_lock_irqsave(&up->port.lock, flags);
1835 1836
	lsr = serial_in(up, UART_LSR);
	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
L
Linus Torvalds 已提交
1837 1838
	spin_unlock_irqrestore(&up->port.lock, flags);

1839
	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
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Linus Torvalds 已提交
1840 1841 1842 1843
}

static unsigned int serial8250_get_mctrl(struct uart_port *port)
{
1844 1845
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
1846
	unsigned int status;
L
Linus Torvalds 已提交
1847 1848
	unsigned int ret;

1849
	status = check_modem_status(up);
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Linus Torvalds 已提交
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864

	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)
{
1865 1866
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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Linus Torvalds 已提交
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886
	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)
{
1887 1888
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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Linus Torvalds 已提交
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899
	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
1900 1901 1902
/*
 *	Wait for transmitter & holding register to empty
 */
1903
static void wait_for_xmitr(struct uart_8250_port *up, int bits)
A
Alex Williamson 已提交
1904 1905 1906 1907
{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
1908
	for (;;) {
A
Alex Williamson 已提交
1909 1910
		status = serial_in(up, UART_LSR);

1911
		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
A
Alex Williamson 已提交
1912

1913 1914
		if ((status & bits) == bits)
			break;
A
Alex Williamson 已提交
1915 1916 1917
		if (--tmout == 0)
			break;
		udelay(1);
1918
	}
A
Alex Williamson 已提交
1919 1920 1921

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
1922 1923 1924 1925 1926 1927
		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
1928 1929 1930 1931 1932 1933
			udelay(1);
			touch_nmi_watchdog();
		}
	}
}

J
Jason Wessel 已提交
1934 1935 1936 1937 1938 1939 1940 1941
#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)
{
1942 1943
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
J
Jason Wessel 已提交
1944 1945
	unsigned char lsr = serial_inp(up, UART_LSR);

1946 1947
	if (!(lsr & UART_LSR_DR))
		return NO_POLL_CHAR;
J
Jason Wessel 已提交
1948 1949 1950 1951 1952 1953 1954 1955 1956

	return serial_inp(up, UART_RX);
}


static void serial8250_put_poll_char(struct uart_port *port,
			 unsigned char c)
{
	unsigned int ier;
1957 1958
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
J
Jason Wessel 已提交
1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989

	/*
	 *	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
1990 1991
static int serial8250_startup(struct uart_port *port)
{
1992 1993
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
1994
	unsigned long flags;
1995
	unsigned char lsr, iir;
L
Linus Torvalds 已提交
1996 1997
	int retval;

O
Ondrej Puzman 已提交
1998 1999
	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
2000 2001 2002
	up->capabilities = uart_config[up->port.type].flags;
	up->mcr = 0;

A
Alan Cox 已提交
2003 2004 2005
	if (up->port.iotype != up->cur_iotype)
		set_io_from_upio(port);

L
Linus Torvalds 已提交
2006 2007 2008
	if (up->port.type == PORT_16C950) {
		/* Wake up and initialize UART */
		up->acr = 0;
2009
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
		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
2029
	 * (they will be reenabled in set_termios())
L
Linus Torvalds 已提交
2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047
	 */
	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)) {
2048 2049
		printk(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
		       serial_index(&up->port));
L
Linus Torvalds 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058
		return -ENODEV;
	}

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

2059
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2060 2061 2062 2063 2064 2065 2066 2067 2068 2069

		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
2070
	if (is_real_interrupt(up->port.irq)) {
2071
		unsigned char iir1;
A
Alex Williamson 已提交
2072 2073 2074 2075 2076 2077 2078 2079
		/*
		 * 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
2080
		spin_lock_irqsave(&up->port.lock, flags);
2081
		if (up->port.irqflags & IRQF_SHARED)
2082
			disable_irq_nosync(up->port.irq);
A
Alex Williamson 已提交
2083 2084 2085 2086

		wait_for_xmitr(up, UART_LSR_THRE);
		serial_out_sync(up, UART_IER, UART_IER_THRI);
		udelay(1); /* allow THRE to set */
2087
		iir1 = serial_in(up, UART_IIR);
A
Alex Williamson 已提交
2088 2089 2090 2091 2092 2093
		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);

2094
		if (up->port.irqflags & IRQF_SHARED)
2095
			enable_irq(up->port.irq);
B
Borislav Petkov 已提交
2096
		spin_unlock_irqrestore(&up->port.lock, flags);
A
Alex Williamson 已提交
2097 2098 2099 2100 2101

		/*
		 * If the interrupt is not reasserted, setup a timer to
		 * kick the UART on a regular basis.
		 */
2102
		if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
2103
			up->bugs |= UART_BUG_THRE;
2104 2105
			pr_debug("ttyS%d - using backup timer\n",
				 serial_index(port));
A
Alex Williamson 已提交
2106 2107 2108
		}
	}

2109 2110 2111 2112 2113 2114 2115 2116
	/*
	 * 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 +
2117
			uart_poll_timeout(port) + HZ / 5);
2118 2119
	}

L
Linus Torvalds 已提交
2120 2121 2122 2123 2124 2125 2126
	/*
	 * 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;
2127
		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
L
Linus Torvalds 已提交
2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150
	} 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);
2151

2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162
	/* 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.
	 */
2163
	if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST)
2164 2165
		goto dont_test_tx_en;

2166 2167 2168 2169 2170 2171 2172 2173 2174 2175
	/*
	 * 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) {
2176 2177
		if (!(up->bugs & UART_BUG_TXEN)) {
			up->bugs |= UART_BUG_TXEN;
2178
			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
2179
				 serial_index(port));
2180 2181
		}
	} else {
2182
		up->bugs &= ~UART_BUG_TXEN;
2183 2184
	}

2185
dont_test_tx_en:
L
Linus Torvalds 已提交
2186 2187
	spin_unlock_irqrestore(&up->port.lock, flags);

2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199
	/*
	 * Clear the interrupt registers again for luck, and clear the
	 * saved flags to avoid getting false values from polling
	 * routines or the previous session.
	 */
	serial_inp(up, UART_LSR);
	serial_inp(up, UART_RX);
	serial_inp(up, UART_IIR);
	serial_inp(up, UART_MSR);
	up->lsr_saved_flags = 0;
	up->msr_saved_flags = 0;

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	/*
	 * Finally, enable interrupts.  Note: Modem status interrupts
	 * are set via set_termios(), which will be occurring imminently
	 * anyway, so we don't enable them here.
	 */
	up->ier = UART_IER_RLSI | UART_IER_RDI;
	serial_outp(up, UART_IER, up->ier);

	if (up->port.flags & UPF_FOURPORT) {
		unsigned int icp;
		/*
		 * Enable interrupts on the AST Fourport board
		 */
		icp = (up->port.iobase & 0xfe0) | 0x01f;
		outb_p(0x80, icp);
		(void) inb_p(icp);
	}

	return 0;
}

static void serial8250_shutdown(struct uart_port *port)
{
2223 2224
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
L
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2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262
	unsigned long flags;

	/*
	 * Disable interrupts from this port
	 */
	up->ier = 0;
	serial_outp(up, UART_IER, 0);

	spin_lock_irqsave(&up->port.lock, flags);
	if (up->port.flags & UPF_FOURPORT) {
		/* reset interrupts on the AST Fourport board */
		inb((up->port.iobase & 0xfe0) | 0x1f);
		up->port.mctrl |= TIOCM_OUT1;
	} else
		up->port.mctrl &= ~TIOCM_OUT2;

	serial8250_set_mctrl(&up->port, up->port.mctrl);
	spin_unlock_irqrestore(&up->port.lock, flags);

	/*
	 * Disable break condition and FIFOs
	 */
	serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
	serial8250_clear_fifos(up);

#ifdef CONFIG_SERIAL_8250_RSA
	/*
	 * Reset the RSA board back to 115kbps compat mode.
	 */
	disable_rsa(up);
#endif

	/*
	 * Read data port to reset things, and then unlink from
	 * the IRQ chain.
	 */
	(void) serial_in(up, UART_RX);

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	del_timer_sync(&up->timer);
	up->timer.function = serial8250_timeout;
	if (is_real_interrupt(up->port.irq))
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2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288
		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;
}

2289 2290 2291
void
serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
		          struct ktermios *old)
L
Linus Torvalds 已提交
2292
{
2293 2294
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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	unsigned char cval, fcr = 0;
	unsigned long flags;
	unsigned int baud, quot;

	switch (termios->c_cflag & CSIZE) {
	case CS5:
2301
		cval = UART_LCR_WLEN5;
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2302 2303
		break;
	case CS6:
2304
		cval = UART_LCR_WLEN6;
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2305 2306
		break;
	case CS7:
2307
		cval = UART_LCR_WLEN7;
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2308 2309 2310
		break;
	default:
	case CS8:
2311
		cval = UART_LCR_WLEN8;
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2312 2313 2314 2315
		break;
	}

	if (termios->c_cflag & CSTOPB)
2316
		cval |= UART_LCR_STOP;
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2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328
	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.
	 */
2329 2330 2331
	baud = uart_get_baud_rate(port, termios, old,
				  port->uartclk / 16 / 0xffff,
				  port->uartclk / 16);
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2332 2333 2334
	quot = serial8250_get_divisor(port, baud);

	/*
2335
	 * Oxford Semi 952 rev B workaround
L
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2336
	 */
2337
	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
A
Alan Cox 已提交
2338
		quot++;
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2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 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

	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
	 */
2403
	up->ier &= ~UART_IER_MSI;
2404 2405
	if (!(up->bugs & UART_BUG_NOMSR) &&
			UART_ENABLE_MS(&up->port, termios->c_cflag))
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Linus Torvalds 已提交
2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421
		up->ier |= UART_IER_MSI;
	if (up->capabilities & UART_CAP_UUE)
		up->ier |= UART_IER_UUE | UART_IER_RTOIE;

	serial_out(up, UART_IER, up->ier);

	if (up->capabilities & UART_CAP_EFR) {
		unsigned char efr = 0;
		/*
		 * TI16C752/Startech hardware flow control.  FIXME:
		 * - TI16C752 requires control thresholds to be set.
		 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
		 */
		if (termios->c_cflag & CRTSCTS)
			efr |= UART_EFR_CTS;

2422
		serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
L
Linus Torvalds 已提交
2423 2424 2425
		serial_outp(up, UART_EFR, efr);
	}

2426
#ifdef CONFIG_ARCH_OMAP
2427
	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
2428
	if (cpu_is_omap1510() && is_omap_port(up)) {
2429 2430 2431 2432 2433 2434 2435 2436
		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
2437 2438 2439 2440 2441 2442 2443
	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 */
	}

2444
	serial_dl_write(up, quot);
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Linus Torvalds 已提交
2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463

	/*
	 * 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
2464 2465 2466
	/* Don't rewrite B0 */
	if (tty_termios_baud_rate(termios))
		tty_termios_encode_baud_rate(termios, baud, baud);
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Linus Torvalds 已提交
2467
}
2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478
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
2479

2480
static void
A
Arnd Bergmann 已提交
2481
serial8250_set_ldisc(struct uart_port *port, int new)
2482
{
A
Arnd Bergmann 已提交
2483
	if (new == N_PPS) {
2484 2485 2486 2487 2488 2489
		port->flags |= UPF_HARDPPS_CD;
		serial8250_enable_ms(port);
	} else
		port->flags &= ~UPF_HARDPPS_CD;
}

2490 2491 2492

void serial8250_do_pm(struct uart_port *port, unsigned int state,
		      unsigned int oldstate)
L
Linus Torvalds 已提交
2493
{
2494 2495
	struct uart_8250_port *p =
		container_of(port, struct uart_8250_port, port);
L
Linus Torvalds 已提交
2496 2497

	serial8250_set_sleep(p, state != 0);
2498 2499
}
EXPORT_SYMBOL(serial8250_do_pm);
L
Linus Torvalds 已提交
2500

2501 2502 2503 2504 2505 2506 2507 2508
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
2509 2510
}

2511 2512 2513
static unsigned int serial8250_port_size(struct uart_8250_port *pt)
{
	if (pt->port.iotype == UPIO_AU)
2514
		return 0x1000;
2515 2516 2517 2518 2519 2520 2521
#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
2522 2523 2524 2525 2526
/*
 * Resource handling.
 */
static int serial8250_request_std_resource(struct uart_8250_port *up)
{
2527
	unsigned int size = serial8250_port_size(up);
L
Linus Torvalds 已提交
2528 2529 2530
	int ret = 0;

	switch (up->port.iotype) {
2531
	case UPIO_AU:
2532 2533
	case UPIO_TSI:
	case UPIO_MEM32:
L
Linus Torvalds 已提交
2534
	case UPIO_MEM:
M
Marc St-Jean 已提交
2535
	case UPIO_DWAPB:
2536
	case UPIO_DWAPB32:
L
Linus Torvalds 已提交
2537 2538 2539 2540 2541 2542 2543 2544 2545
		if (!up->port.mapbase)
			break;

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

		if (up->port.flags & UPF_IOREMAP) {
2546 2547
			up->port.membase = ioremap_nocache(up->port.mapbase,
									size);
L
Linus Torvalds 已提交
2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565
			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)
{
2566
	unsigned int size = serial8250_port_size(up);
L
Linus Torvalds 已提交
2567 2568

	switch (up->port.iotype) {
2569
	case UPIO_AU:
2570 2571
	case UPIO_TSI:
	case UPIO_MEM32:
L
Linus Torvalds 已提交
2572
	case UPIO_MEM:
M
Marc St-Jean 已提交
2573
	case UPIO_DWAPB:
2574
	case UPIO_DWAPB32:
L
Linus Torvalds 已提交
2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596
		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;
2597
	int ret = -EINVAL;
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	switch (up->port.iotype) {
	case UPIO_HUB6:
	case UPIO_PORT:
		start += up->port.iobase;
2603 2604 2605
		if (request_region(start, size, "serial-rsa"))
			ret = 0;
		else
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2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627
			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)
{
2628 2629
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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2630 2631 2632 2633 2634 2635 2636 2637

	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)
{
2638 2639
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653
	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)
{
2654 2655
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
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Linus Torvalds 已提交
2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670
	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;

A
Alan Cox 已提交
2671 2672 2673
	if (up->port.iotype != up->cur_iotype)
		set_io_from_upio(port);

L
Linus Torvalds 已提交
2674 2675
	if (flags & UART_CONFIG_TYPE)
		autoconfig(up, probeflags);
2676 2677 2678 2679 2680

	/* 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;

L
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2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692
	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,
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	.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];

2738 2739 2740 2741 2742 2743 2744 2745 2746 2747
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;
2752
	int i, irqflag = 0;
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	if (!first)
		return;
	first = 0;

2758
	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;
	}

2776 2777 2778
	if (share_irqs)
		irqflag = IRQF_SHARED;

2779
	for (i = 0, up = serial8250_ports;
2780
	     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);
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		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;
2791
		set_io_from_upio(&up->port);
2792
		up->port.irqflags |= irqflag;
2793 2794 2795
		if (serial8250_isa_config != NULL)
			serial8250_isa_config(i, &up->port, &up->capabilities);

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	}
}

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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();

2820
	for (i = 0; i < nr_uarts; i++) {
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		struct uart_8250_port *up = &serial8250_ports[i];

		up->port.dev = dev;
2824 2825 2826 2827

		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

2834 2835
static void serial8250_console_putchar(struct uart_port *port, int ch)
{
2836 2837
	struct uart_8250_port *up =
		container_of(port, struct uart_8250_port, port);
2838 2839 2840 2841 2842

	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];
2853
	unsigned long flags;
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	unsigned int ier;
2855
	int locked = 1;
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2857 2858
	touch_nmi_watchdog();

2859 2860 2861 2862 2863 2864
	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);
2865
	} else
2866
		spin_lock(&up->port.lock);
2867

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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);

2878
	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);
2885
	serial_out(up, UART_IER, ier);
2886

2887 2888 2889 2890 2891 2892 2893 2894 2895 2896
	/*
	 *	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);

2897
	if (locked)
2898 2899
		spin_unlock(&up->port.lock);
	local_irq_restore(flags);
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}

2902
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.
	 */
2915
	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);
}

2927
static int serial8250_console_early_setup(void)
2928 2929 2930 2931
{
	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,
2937
	.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)
{
2945 2946 2947
	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);

2954
int serial8250_find_port(struct uart_port *p)
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{
	int line;
	struct uart_port *port;

2959
	for (line = 0; line < nr_uarts; line++) {
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		port = &serial8250_ports[line].port;
2961
		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,
};

2981 2982 2983 2984 2985 2986
/*
 * 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;
2999
	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;
3007 3008
	p->type		= port->type;
	p->line		= port->line;
3009 3010 3011 3012 3013 3014 3015

	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)
{
3038 3039 3040 3041 3042 3043
	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);

3044
		ns16550a_goto_highspeed(up);
3045 3046

		serial_outp(up, UART_LCR, 0);
3047
		up->port.uartclk = 921600*16;
3048 3049
	}
	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.
 */
3057
static int __devinit serial8250_probe(struct platform_device *dev)
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{
3059
	struct plat_serial8250_port *p = dev->dev.platform_data;
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	struct uart_port port;
3061
	int ret, i, irqflag = 0;
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	memset(&port, 0, sizeof(struct uart_port));

3065 3066 3067
	if (share_irqs)
		irqflag = IRQF_SHARED;

3068
	for (i = 0; p && p->flags != 0; p++, i++) {
3069 3070 3071
		port.iobase		= p->iobase;
		port.membase		= p->membase;
		port.irq		= p->irq;
3072
		port.irqflags		= p->irqflags;
3073 3074 3075 3076 3077 3078 3079
		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;
3080
		port.type		= p->type;
3081 3082
		port.serial_in		= p->serial_in;
		port.serial_out		= p->serial_out;
3083
		port.set_termios	= p->set_termios;
3084
		port.pm			= p->pm;
3085
		port.dev		= &dev->dev;
3086
		port.irqflags		|= irqflag;
3087 3088
		ret = serial8250_register_port(&port);
		if (ret < 0) {
3089
			dev_err(&dev->dev, "unable to register port at index %d "
3090 3091 3092
				"(IO%lx MEM%llx IRQ%d): %d\n", i,
				p->iobase, (unsigned long long)p->mapbase,
				p->irq, ret);
3093
		}
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	}
	return 0;
}

/*
 * Remove serial ports registered against a platform device.
 */
3101
static int __devexit serial8250_remove(struct platform_device *dev)
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{
	int i;

3105
	for (i = 0; i < nr_uarts; i++) {
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		struct uart_8250_port *up = &serial8250_ports[i];

3108
		if (up->port.dev == &dev->dev)
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			serial8250_unregister_port(i);
	}
	return 0;
}

3114
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];

3121
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
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			uart_suspend_port(&serial8250_reg, &up->port);
	}

	return 0;
}

3128
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];

3135
		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
3136
			serial8250_resume_port(i);
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	}

	return 0;
}

3142
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,
3147 3148
	.driver		= {
		.name	= "serial8250",
3149
		.owner	= THIS_MODULE,
3150
	},
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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.
 */
3164
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.
	 */
3173
	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).
	 */
3182
	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.
	 */
3191
	for (i = 0; i < nr_uarts; i++)
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		if (serial8250_ports[i].port.type == PORT_UNKNOWN)
			return &serial8250_ports[i];

	return NULL;
}

/**
 *	serial8250_register_port - register a serial port
 *	@port: serial port template
 *
 *	Configure the serial port specified by the request. If the
 *	port exists and is in use, it is hung up and unregistered
 *	first.
 *
 *	The port is then probed and if necessary the IRQ is autodetected
 *	If this fails an error is returned.
 *
 *	On success the port is ready to use and the line number is returned.
 */
int serial8250_register_port(struct uart_port *port)
{
	struct uart_8250_port *uart;
	int ret = -ENOSPC;

	if (port->uartclk == 0)
		return -EINVAL;

3219
	mutex_lock(&serial_mutex);
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	uart = serial8250_find_match_or_unused(port);
	if (uart) {
		uart_remove_one_port(&serial8250_reg, &uart->port);

3225 3226 3227
		uart->port.iobase       = port->iobase;
		uart->port.membase      = port->membase;
		uart->port.irq          = port->irq;
3228
		uart->port.irqflags     = port->irqflags;
3229 3230 3231 3232 3233 3234 3235
		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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3236 3237
		if (port->dev)
			uart->port.dev = port->dev;
3238

3239 3240
		if (port->flags & UPF_FIXED_TYPE)
			serial8250_init_fixed_type_port(uart, port->type);
3241

3242 3243 3244 3245 3246 3247
		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;
3248 3249 3250
		/*  Possibly override set_termios call */
		if (port->set_termios)
			uart->port.set_termios = port->set_termios;
3251 3252
		if (port->pm)
			uart->port.pm = port->pm;
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3253

3254 3255 3256 3257
		if (serial8250_isa_config != NULL)
			serial8250_isa_config(0, &uart->port,
					&uart->capabilities);

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3258 3259 3260 3261
		ret = uart_add_one_port(&serial8250_reg, &uart->port);
		if (ret == 0)
			ret = uart->port.line;
	}
3262
	mutex_unlock(&serial_mutex);
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3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278

	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];

3279
	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;
	}
3289
	mutex_unlock(&serial_mutex);
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3290 3291 3292 3293 3294
}
EXPORT_SYMBOL(serial8250_unregister_port);

static int __init serial8250_init(void)
{
A
Alan Cox 已提交
3295
	int ret;
L
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3296

3297 3298 3299
	if (nr_uarts > UART_NR)
		nr_uarts = UART_NR;

3300
	printk(KERN_INFO "Serial: 8250/16550 driver, "
3301
		"%d ports, IRQ sharing %sabled\n", nr_uarts,
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3302 3303
		share_irqs ? "en" : "dis");

3304 3305 3306 3307
#ifdef CONFIG_SPARC
	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
#else
	serial8250_reg.nr = UART_NR;
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3308
	ret = uart_register_driver(&serial8250_reg);
3309
#endif
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3310 3311 3312
	if (ret)
		goto out;

3313 3314 3315 3316
	serial8250_isa_devs = platform_device_alloc("serial8250",
						    PLAT8250_DEV_LEGACY);
	if (!serial8250_isa_devs) {
		ret = -ENOMEM;
3317
		goto unreg_uart_drv;
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3318 3319
	}

3320 3321 3322 3323
	ret = platform_device_add(serial8250_isa_devs);
	if (ret)
		goto put_dev;

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3324 3325
	serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);

3326 3327 3328
	ret = platform_driver_register(&serial8250_isa_driver);
	if (ret == 0)
		goto out;
L
Linus Torvalds 已提交
3329

3330
	platform_device_del(serial8250_isa_devs);
A
Alan Cox 已提交
3331
put_dev:
3332
	platform_device_put(serial8250_isa_devs);
A
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3333
unreg_uart_drv:
3334 3335 3336
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
L
Linus Torvalds 已提交
3337
	uart_unregister_driver(&serial8250_reg);
3338
#endif
A
Alan Cox 已提交
3339
out:
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3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353
	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;

3354
	platform_driver_unregister(&serial8250_isa_driver);
L
Linus Torvalds 已提交
3355 3356
	platform_device_unregister(isa_dev);

3357 3358 3359
#ifdef CONFIG_SPARC
	sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
L
Linus Torvalds 已提交
3360
	uart_unregister_driver(&serial8250_reg);
3361
#endif
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3362 3363 3364 3365 3366 3367 3368 3369 3370
}

module_init(serial8250_init);
module_exit(serial8250_exit);

EXPORT_SYMBOL(serial8250_suspend_port);
EXPORT_SYMBOL(serial8250_resume_port);

MODULE_LICENSE("GPL");
3371
MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
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3372 3373 3374 3375 3376

module_param(share_irqs, uint, 0644);
MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
	" (unsafe)");

3377 3378 3379
module_param(nr_uarts, uint, 0644);
MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");

3380 3381 3382
module_param(skip_txen_test, uint, 0644);
MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");

L
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3383 3384 3385 3386 3387
#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);