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linux/drivers/serial/8250.c
Russell King c5f4644e6c [PATCH] Serial: Adjust serial locking 
This patch changes the way serial ports are locked when getting modem
status.  This change is necessary because we will need to atomically
read the modem status and take action depending on the CTS status.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-06-29 09:42:38 +01:00

2663 lines
66 KiB
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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.
*
* $Id: 8250.c,v 1.90 2002/07/28 10:03:27 rmk Exp $
*
* A note about mapbase / membase
*
* mapbase is the physical address of the IO port.
* membase is an 'ioremapped' cookie.
*/
#include <linux/config.h>
#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/mca.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_reg.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/irq.h>
#include "8250.h"
/*
* Configuration:
* share_irqs - whether we pass SA_SHIRQ to request_irq(). This option
* is unsafe when used on edge-triggered interrupts.
*/
static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
/*
* Debugging.
*/
#if 0
#define DEBUG_AUTOCONF(fmt...) printk(fmt)
#else
#define DEBUG_AUTOCONF(fmt...) do { } while (0)
#endif
#if 0
#define DEBUG_INTR(fmt...) printk(fmt)
#else
#define DEBUG_INTR(fmt...) do { } while (0)
#endif
#define PASS_LIMIT 256
/*
* We default to IRQ0 for the "no irq" hack. Some
* machine types want others as well - they're free
* to redefine this in their header file.
*/
#define is_real_interrupt(irq) ((irq) != 0)
#ifdef CONFIG_SERIAL_8250_DETECT_IRQ
#define CONFIG_SERIAL_DETECT_IRQ 1
#endif
#ifdef CONFIG_SERIAL_8250_MANY_PORTS
#define CONFIG_SERIAL_MANY_PORTS 1
#endif
/*
* HUB6 is always on. This will be removed once the header
* files have been cleaned.
*/
#define CONFIG_HUB6 1
#include <asm/serial.h>
/*
* SERIAL_PORT_DFNS tells us about built-in ports that have no
* standard enumeration mechanism. Platforms that can find all
* serial ports via mechanisms like ACPI or PCI need not supply it.
*/
#ifndef SERIAL_PORT_DFNS
#define SERIAL_PORT_DFNS
#endif
static struct old_serial_port old_serial_port[] = {
SERIAL_PORT_DFNS /* defined in asm/serial.h */
};
#define UART_NR (ARRAY_SIZE(old_serial_port) + CONFIG_SERIAL_8250_NR_UARTS)
#ifdef CONFIG_SERIAL_8250_RSA
#define PORT_RSA_MAX 4
static unsigned long probe_rsa[PORT_RSA_MAX];
static unsigned int probe_rsa_count;
#endif /* CONFIG_SERIAL_8250_RSA */
struct uart_8250_port {
struct uart_port port;
struct timer_list timer; /* "no irq" timer */
struct list_head list; /* ports on this IRQ */
unsigned short capabilities; /* port capabilities */
unsigned short bugs; /* port bugs */
unsigned int tx_loadsz; /* transmit fifo load size */
unsigned char acr;
unsigned char ier;
unsigned char lcr;
unsigned char mcr;
unsigned char mcr_mask; /* mask of user bits */
unsigned char mcr_force; /* mask of forced bits */
unsigned char lsr_break_flag;
/*
* We provide a per-port pm hook.
*/
void (*pm)(struct uart_port *port,
unsigned int state, unsigned int old);
};
struct irq_info {
spinlock_t lock;
struct list_head *head;
};
static struct irq_info irq_lists[NR_IRQS];
/*
* Here we define the default xmit fifo size used for each type of UART.
*/
static const struct serial8250_config uart_config[] = {
[PORT_UNKNOWN] = {
.name = "unknown",
.fifo_size = 1,
.tx_loadsz = 1,
},
[PORT_8250] = {
.name = "8250",
.fifo_size = 1,
.tx_loadsz = 1,
},
[PORT_16450] = {
.name = "16450",
.fifo_size = 1,
.tx_loadsz = 1,
},
[PORT_16550] = {
.name = "16550",
.fifo_size = 1,
.tx_loadsz = 1,
},
[PORT_16550A] = {
.name = "16550A",
.fifo_size = 16,
.tx_loadsz = 16,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
.flags = UART_CAP_FIFO,
},
[PORT_CIRRUS] = {
.name = "Cirrus",
.fifo_size = 1,
.tx_loadsz = 1,
},
[PORT_16650] = {
.name = "ST16650",
.fifo_size = 1,
.tx_loadsz = 1,
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
},
[PORT_16650V2] = {
.name = "ST16650V2",
.fifo_size = 32,
.tx_loadsz = 16,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
UART_FCR_T_TRIG_00,
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
},
[PORT_16750] = {
.name = "TI16750",
.fifo_size = 64,
.tx_loadsz = 64,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
UART_FCR7_64BYTE,
.flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
},
[PORT_STARTECH] = {
.name = "Startech",
.fifo_size = 1,
.tx_loadsz = 1,
},
[PORT_16C950] = {
.name = "16C950/954",
.fifo_size = 128,
.tx_loadsz = 128,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
.flags = UART_CAP_FIFO,
},
[PORT_16654] = {
.name = "ST16654",
.fifo_size = 64,
.tx_loadsz = 32,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
UART_FCR_T_TRIG_10,
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
},
[PORT_16850] = {
.name = "XR16850",
.fifo_size = 128,
.tx_loadsz = 128,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
},
[PORT_RSA] = {
.name = "RSA",
.fifo_size = 2048,
.tx_loadsz = 2048,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
.flags = UART_CAP_FIFO,
},
[PORT_NS16550A] = {
.name = "NS16550A",
.fifo_size = 16,
.tx_loadsz = 16,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
.flags = UART_CAP_FIFO | UART_NATSEMI,
},
[PORT_XSCALE] = {
.name = "XScale",
.fifo_size = 32,
.tx_loadsz = 32,
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
.flags = UART_CAP_FIFO | UART_CAP_UUE,
},
};
static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
{
offset <<= up->port.regshift;
switch (up->port.iotype) {
case UPIO_HUB6:
outb(up->port.hub6 - 1 + offset, up->port.iobase);
return inb(up->port.iobase + 1);
case UPIO_MEM:
return readb(up->port.membase + offset);
case UPIO_MEM32:
return readl(up->port.membase + offset);
default:
return inb(up->port.iobase + offset);
}
}
static _INLINE_ void
serial_out(struct uart_8250_port *up, int offset, int value)
{
offset <<= up->port.regshift;
switch (up->port.iotype) {
case UPIO_HUB6:
outb(up->port.hub6 - 1 + offset, up->port.iobase);
outb(value, up->port.iobase + 1);
break;
case UPIO_MEM:
writeb(value, up->port.membase + offset);
break;
case UPIO_MEM32:
writel(value, up->port.membase + offset);
break;
default:
outb(value, up->port.iobase + offset);
}
}
/*
* 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)
/*
* For the 16C950
*/
static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
{
serial_out(up, UART_SCR, offset);
serial_out(up, UART_ICR, value);
}
static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
{
unsigned int value;
serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
serial_out(up, UART_SCR, offset);
value = serial_in(up, UART_ICR);
serial_icr_write(up, UART_ACR, up->acr);
return value;
}
/*
* FIFO support.
*/
static inline void serial8250_clear_fifos(struct uart_8250_port *p)
{
if (p->capabilities & UART_CAP_FIFO) {
serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO);
serial_outp(p, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
serial_outp(p, UART_FCR, 0);
}
}
/*
* IER sleep support. UARTs which have EFRs need the "extended
* capability" bit enabled. Note that on XR16C850s, we need to
* reset LCR to write to IER.
*/
static inline void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
{
if (p->capabilities & UART_CAP_SLEEP) {
if (p->capabilities & UART_CAP_EFR) {
serial_outp(p, UART_LCR, 0xBF);
serial_outp(p, UART_EFR, UART_EFR_ECB);
serial_outp(p, UART_LCR, 0);
}
serial_outp(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
if (p->capabilities & UART_CAP_EFR) {
serial_outp(p, UART_LCR, 0xBF);
serial_outp(p, UART_EFR, 0);
serial_outp(p, UART_LCR, 0);
}
}
}
#ifdef CONFIG_SERIAL_8250_RSA
/*
* Attempts to turn on the RSA FIFO. Returns zero on failure.
* We set the port uart clock rate if we succeed.
*/
static int __enable_rsa(struct uart_8250_port *up)
{
unsigned char mode;
int result;
mode = serial_inp(up, UART_RSA_MSR);
result = mode & UART_RSA_MSR_FIFO;
if (!result) {
serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
mode = serial_inp(up, UART_RSA_MSR);
result = mode & UART_RSA_MSR_FIFO;
}
if (result)
up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
return result;
}
static void enable_rsa(struct uart_8250_port *up)
{
if (up->port.type == PORT_RSA) {
if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
spin_lock_irq(&up->port.lock);
__enable_rsa(up);
spin_unlock_irq(&up->port.lock);
}
if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
serial_outp(up, UART_RSA_FRR, 0);
}
}
/*
* Attempts to turn off the RSA FIFO. Returns zero on failure.
* It is unknown why interrupts were disabled in here. However,
* the caller is expected to preserve this behaviour by grabbing
* the spinlock before calling this function.
*/
static void disable_rsa(struct uart_8250_port *up)
{
unsigned char mode;
int result;
if (up->port.type == PORT_RSA &&
up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
spin_lock_irq(&up->port.lock);
mode = serial_inp(up, UART_RSA_MSR);
result = !(mode & UART_RSA_MSR_FIFO);
if (!result) {
serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
mode = serial_inp(up, UART_RSA_MSR);
result = !(mode & UART_RSA_MSR_FIFO);
}
if (result)
up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
spin_unlock_irq(&up->port.lock);
}
}
#endif /* CONFIG_SERIAL_8250_RSA */
/*
* This is a quickie test to see how big the FIFO is.
* It doesn't work at all the time, more's the pity.
*/
static int size_fifo(struct uart_8250_port *up)
{
unsigned char old_fcr, old_mcr, old_dll, old_dlm, old_lcr;
int count;
old_lcr = serial_inp(up, UART_LCR);
serial_outp(up, UART_LCR, 0);
old_fcr = serial_inp(up, UART_FCR);
old_mcr = serial_inp(up, UART_MCR);
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
serial_outp(up, UART_MCR, UART_MCR_LOOP);
serial_outp(up, UART_LCR, UART_LCR_DLAB);
old_dll = serial_inp(up, UART_DLL);
old_dlm = serial_inp(up, UART_DLM);
serial_outp(up, UART_DLL, 0x01);
serial_outp(up, UART_DLM, 0x00);
serial_outp(up, UART_LCR, 0x03);
for (count = 0; count < 256; count++)
serial_outp(up, UART_TX, count);
mdelay(20);/* FIXME - schedule_timeout */
for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
(count < 256); count++)
serial_inp(up, UART_RX);
serial_outp(up, UART_FCR, old_fcr);
serial_outp(up, UART_MCR, old_mcr);
serial_outp(up, UART_LCR, UART_LCR_DLAB);
serial_outp(up, UART_DLL, old_dll);
serial_outp(up, UART_DLM, old_dlm);
serial_outp(up, UART_LCR, old_lcr);
return count;
}
/*
* Read UART ID using the divisor method - set DLL and DLM to zero
* and the revision will be in DLL and device type in DLM. We
* preserve the device state across this.
*/
static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
{
unsigned char old_dll, old_dlm, old_lcr;
unsigned int id;
old_lcr = serial_inp(p, UART_LCR);
serial_outp(p, UART_LCR, UART_LCR_DLAB);
old_dll = serial_inp(p, UART_DLL);
old_dlm = serial_inp(p, UART_DLM);
serial_outp(p, UART_DLL, 0);
serial_outp(p, UART_DLM, 0);
id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
serial_outp(p, UART_DLL, old_dll);
serial_outp(p, UART_DLM, old_dlm);
serial_outp(p, UART_LCR, old_lcr);
return id;
}
/*
* This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
* When this function is called we know it is at least a StarTech
* 16650 V2, but it might be one of several StarTech UARTs, or one of
* its clones. (We treat the broken original StarTech 16650 V1 as a
* 16550, and why not? Startech doesn't seem to even acknowledge its
* existence.)
*
* What evil have men's minds wrought...
*/
static void autoconfig_has_efr(struct uart_8250_port *up)
{
unsigned int id1, id2, id3, rev;
/*
* Everything with an EFR has SLEEP
*/
up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
/*
* First we check to see if it's an Oxford Semiconductor UART.
*
* If we have to do this here because some non-National
* Semiconductor clone chips lock up if you try writing to the
* LSR register (which serial_icr_read does)
*/
/*
* Check for Oxford Semiconductor 16C950.
*
* EFR [4] must be set else this test fails.
*
* This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
* claims that it's needed for 952 dual UART's (which are not
* recommended for new designs).
*/
up->acr = 0;
serial_out(up, UART_LCR, 0xBF);
serial_out(up, UART_EFR, UART_EFR_ECB);
serial_out(up, UART_LCR, 0x00);
id1 = serial_icr_read(up, UART_ID1);
id2 = serial_icr_read(up, UART_ID2);
id3 = serial_icr_read(up, UART_ID3);
rev = serial_icr_read(up, UART_REV);
DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
if (id1 == 0x16 && id2 == 0xC9 &&
(id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
up->port.type = PORT_16C950;
/*
* Enable work around for the Oxford Semiconductor 952 rev B
* chip which causes it to seriously miscalculate baud rates
* when DLL is 0.
*/
if (id3 == 0x52 && rev == 0x01)
up->bugs |= UART_BUG_QUOT;
return;
}
/*
* We check for a XR16C850 by setting DLL and DLM to 0, and then
* reading back DLL and DLM. The chip type depends on the DLM
* value read back:
* 0x10 - XR16C850 and the DLL contains the chip revision.
* 0x12 - XR16C2850.
* 0x14 - XR16C854.
*/
id1 = autoconfig_read_divisor_id(up);
DEBUG_AUTOCONF("850id=%04x ", id1);
id2 = id1 >> 8;
if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
up->port.type = PORT_16850;
return;
}
/*
* It wasn't an XR16C850.
*
* We distinguish between the '654 and the '650 by counting
* how many bytes are in the FIFO. I'm using this for now,
* since that's the technique that was sent to me in the
* serial driver update, but I'm not convinced this works.
* I've had problems doing this in the past. -TYT
*/
if (size_fifo(up) == 64)
up->port.type = PORT_16654;
else
up->port.type = PORT_16650V2;
}
/*
* We detected a chip without a FIFO. Only two fall into
* this category - the original 8250 and the 16450. The
* 16450 has a scratch register (accessible with LCR=0)
*/
static void autoconfig_8250(struct uart_8250_port *up)
{
unsigned char scratch, status1, status2;
up->port.type = PORT_8250;
scratch = serial_in(up, UART_SCR);
serial_outp(up, UART_SCR, 0xa5);
status1 = serial_in(up, UART_SCR);
serial_outp(up, UART_SCR, 0x5a);
status2 = serial_in(up, UART_SCR);
serial_outp(up, UART_SCR, scratch);
if (status1 == 0xa5 && status2 == 0x5a)
up->port.type = PORT_16450;
}
static int broken_efr(struct uart_8250_port *up)
{
/*
* Exar ST16C2550 "A2" devices incorrectly detect as
* having an EFR, and report an ID of 0x0201. See
* http://www.exar.com/info.php?pdf=dan180_oct2004.pdf
*/
if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
return 1;
return 0;
}
/*
* We know that the chip has FIFOs. Does it have an EFR? The
* EFR is located in the same register position as the IIR and
* we know the top two bits of the IIR are currently set. The
* EFR should contain zero. Try to read the EFR.
*/
static void autoconfig_16550a(struct uart_8250_port *up)
{
unsigned char status1, status2;
unsigned int iersave;
up->port.type = PORT_16550A;
up->capabilities |= UART_CAP_FIFO;
/*
* Check for presence of the EFR when DLAB is set.
* Only ST16C650V1 UARTs pass this test.
*/
serial_outp(up, UART_LCR, UART_LCR_DLAB);
if (serial_in(up, UART_EFR) == 0) {
serial_outp(up, UART_EFR, 0xA8);
if (serial_in(up, UART_EFR) != 0) {
DEBUG_AUTOCONF("EFRv1 ");
up->port.type = PORT_16650;
up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
} else {
DEBUG_AUTOCONF("Motorola 8xxx DUART ");
}
serial_outp(up, UART_EFR, 0);
return;
}
/*
* Maybe it requires 0xbf to be written to the LCR.
* (other ST16C650V2 UARTs, TI16C752A, etc)
*/
serial_outp(up, UART_LCR, 0xBF);
if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
DEBUG_AUTOCONF("EFRv2 ");
autoconfig_has_efr(up);
return;
}
/*
* Check for a National Semiconductor SuperIO chip.
* Attempt to switch to bank 2, read the value of the LOOP bit
* from EXCR1. Switch back to bank 0, change it in MCR. Then
* switch back to bank 2, read it from EXCR1 again and check
* it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
*/
serial_outp(up, UART_LCR, 0);
status1 = serial_in(up, UART_MCR);
serial_outp(up, UART_LCR, 0xE0);
status2 = serial_in(up, 0x02); /* EXCR1 */
if (!((status2 ^ status1) & UART_MCR_LOOP)) {
serial_outp(up, UART_LCR, 0);
serial_outp(up, UART_MCR, status1 ^ UART_MCR_LOOP);
serial_outp(up, UART_LCR, 0xE0);
status2 = serial_in(up, 0x02); /* EXCR1 */
serial_outp(up, UART_LCR, 0);
serial_outp(up, UART_MCR, status1);
if ((status2 ^ status1) & UART_MCR_LOOP) {
unsigned short quot;
serial_outp(up, UART_LCR, 0xE0);
quot = serial_inp(up, UART_DLM) << 8;
quot += serial_inp(up, UART_DLL);
quot <<= 3;
status1 = serial_in(up, 0x04); /* EXCR1 */
status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
serial_outp(up, 0x04, status1);
serial_outp(up, UART_DLL, quot & 0xff);
serial_outp(up, UART_DLM, quot >> 8);
serial_outp(up, UART_LCR, 0);
up->port.uartclk = 921600*16;
up->port.type = PORT_NS16550A;
up->capabilities |= UART_NATSEMI;
return;
}
}
/*
* No EFR. Try to detect a TI16750, which only sets bit 5 of
* the IIR when 64 byte FIFO mode is enabled when DLAB is set.
* Try setting it with and without DLAB set. Cheap clones
* set bit 5 without DLAB set.
*/
serial_outp(up, UART_LCR, 0);
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
status1 = serial_in(up, UART_IIR) >> 5;
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
serial_outp(up, UART_LCR, UART_LCR_DLAB);
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
status2 = serial_in(up, UART_IIR) >> 5;
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
serial_outp(up, UART_LCR, 0);
DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
if (status1 == 6 && status2 == 7) {
up->port.type = PORT_16750;
up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
return;
}
/*
* Try writing and reading the UART_IER_UUE bit (b6).
* If it works, this is probably one of the Xscale platform's
* internal UARTs.
* We're going to explicitly set the UUE bit to 0 before
* trying to write and read a 1 just to make sure it's not
* already a 1 and maybe locked there before we even start start.
*/
iersave = serial_in(up, UART_IER);
serial_outp(up, UART_IER, iersave & ~UART_IER_UUE);
if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
/*
* OK it's in a known zero state, try writing and reading
* without disturbing the current state of the other bits.
*/
serial_outp(up, UART_IER, iersave | UART_IER_UUE);
if (serial_in(up, UART_IER) & UART_IER_UUE) {
/*
* It's an Xscale.
* We'll leave the UART_IER_UUE bit set to 1 (enabled).
*/
DEBUG_AUTOCONF("Xscale ");
up->port.type = PORT_XSCALE;
up->capabilities |= UART_CAP_UUE;
return;
}
} else {
/*
* If we got here we couldn't force the IER_UUE bit to 0.
* Log it and continue.
*/
DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
}
serial_outp(up, UART_IER, iersave);
}
/*
* This routine is called by rs_init() to initialize a specific serial
* port. It determines what type of UART chip this serial port is
* using: 8250, 16450, 16550, 16550A. The important question is
* whether or not this UART is a 16550A or not, since this will
* determine whether or not we can use its FIFO features or not.
*/
static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
{
unsigned char status1, scratch, scratch2, scratch3;
unsigned char save_lcr, save_mcr;
unsigned long flags;
if (!up->port.iobase && !up->port.mapbase && !up->port.membase)
return;
DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ",
up->port.line, up->port.iobase, up->port.membase);
/*
* We really do need global IRQs disabled here - we're going to
* be frobbing the chips IRQ enable register to see if it exists.
*/
spin_lock_irqsave(&up->port.lock, flags);
// save_flags(flags); cli();
up->capabilities = 0;
up->bugs = 0;
if (!(up->port.flags & UPF_BUGGY_UART)) {
/*
* Do a simple existence test first; if we fail this,
* there's no point trying anything else.
*
* 0x80 is used as a nonsense port to prevent against
* false positives due to ISA bus float. The
* assumption is that 0x80 is a non-existent port;
* which should be safe since include/asm/io.h also
* makes this assumption.
*
* Note: this is safe as long as MCR bit 4 is clear
* and the device is in "PC" mode.
*/
scratch = serial_inp(up, UART_IER);
serial_outp(up, UART_IER, 0);
#ifdef __i386__
outb(0xff, 0x080);
#endif
scratch2 = serial_inp(up, UART_IER);
serial_outp(up, UART_IER, 0x0F);
#ifdef __i386__
outb(0, 0x080);
#endif
scratch3 = serial_inp(up, UART_IER);
serial_outp(up, UART_IER, scratch);
if (scratch2 != 0 || scratch3 != 0x0F) {
/*
* We failed; there's nothing here
*/
DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
scratch2, scratch3);
goto out;
}
}
save_mcr = serial_in(up, UART_MCR);
save_lcr = serial_in(up, UART_LCR);
/*
* Check to see if a UART is really there. Certain broken
* internal modems based on the Rockwell chipset fail this
* test, because they apparently don't implement the loopback
* test mode. So this test is skipped on the COM 1 through
* COM 4 ports. This *should* be safe, since no board
* manufacturer would be stupid enough to design a board
* that conflicts with COM 1-4 --- we hope!
*/
if (!(up->port.flags & UPF_SKIP_TEST)) {
serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
status1 = serial_inp(up, UART_MSR) & 0xF0;
serial_outp(up, UART_MCR, save_mcr);
if (status1 != 0x90) {
DEBUG_AUTOCONF("LOOP test failed (%02x) ",
status1);
goto out;
}
}
/*
* We're pretty sure there's a port here. Lets find out what
* type of port it is. The IIR top two bits allows us to find
* out if its 8250 or 16450, 16550, 16550A or later. This
* determines what we test for next.
*
* We also initialise the EFR (if any) to zero for later. The
* EFR occupies the same register location as the FCR and IIR.
*/
serial_outp(up, UART_LCR, 0xBF);
serial_outp(up, UART_EFR, 0);
serial_outp(up, UART_LCR, 0);
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
scratch = serial_in(up, UART_IIR) >> 6;
DEBUG_AUTOCONF("iir=%d ", scratch);
switch (scratch) {
case 0:
autoconfig_8250(up);
break;
case 1:
up->port.type = PORT_UNKNOWN;
break;
case 2:
up->port.type = PORT_16550;
break;
case 3:
autoconfig_16550a(up);
break;
}
#ifdef CONFIG_SERIAL_8250_RSA
/*
* Only probe for RSA ports if we got the region.
*/
if (up->port.type == PORT_16550A && probeflags & PROBE_RSA) {
int i;
for (i = 0 ; i < probe_rsa_count; ++i) {
if (probe_rsa[i] == up->port.iobase &&
__enable_rsa(up)) {
up->port.type = PORT_RSA;
break;
}
}
}
#endif
serial_outp(up, UART_LCR, save_lcr);
if (up->capabilities != uart_config[up->port.type].flags) {
printk(KERN_WARNING
"ttyS%d: detected caps %08x should be %08x\n",
up->port.line, up->capabilities,
uart_config[up->port.type].flags);
}
up->port.fifosize = uart_config[up->port.type].fifo_size;
up->capabilities = uart_config[up->port.type].flags;
up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
if (up->port.type == PORT_UNKNOWN)
goto out;
/*
* Reset the UART.
*/
#ifdef CONFIG_SERIAL_8250_RSA
if (up->port.type == PORT_RSA)
serial_outp(up, UART_RSA_FRR, 0);
#endif
serial_outp(up, UART_MCR, save_mcr);
serial8250_clear_fifos(up);
(void)serial_in(up, UART_RX);
serial_outp(up, UART_IER, 0);
out:
spin_unlock_irqrestore(&up->port.lock, flags);
// restore_flags(flags);
DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
}
static void autoconfig_irq(struct uart_8250_port *up)
{
unsigned char save_mcr, save_ier;
unsigned char save_ICP = 0;
unsigned int ICP = 0;
unsigned long irqs;
int irq;
if (up->port.flags & UPF_FOURPORT) {
ICP = (up->port.iobase & 0xfe0) | 0x1f;
save_ICP = inb_p(ICP);
outb_p(0x80, ICP);
(void) inb_p(ICP);
}
/* forget possible initially masked and pending IRQ */
probe_irq_off(probe_irq_on());
save_mcr = serial_inp(up, UART_MCR);
save_ier = serial_inp(up, UART_IER);
serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
irqs = probe_irq_on();
serial_outp(up, UART_MCR, 0);
udelay (10);
if (up->port.flags & UPF_FOURPORT) {
serial_outp(up, UART_MCR,
UART_MCR_DTR | UART_MCR_RTS);
} else {
serial_outp(up, UART_MCR,
UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
}
serial_outp(up, UART_IER, 0x0f); /* enable all intrs */
(void)serial_inp(up, UART_LSR);
(void)serial_inp(up, UART_RX);
(void)serial_inp(up, UART_IIR);
(void)serial_inp(up, UART_MSR);
serial_outp(up, UART_TX, 0xFF);
udelay (20);
irq = probe_irq_off(irqs);
serial_outp(up, UART_MCR, save_mcr);
serial_outp(up, UART_IER, save_ier);
if (up->port.flags & UPF_FOURPORT)
outb_p(save_ICP, ICP);
up->port.irq = (irq > 0) ? irq : 0;
}
static void serial8250_stop_tx(struct uart_port *port, unsigned int tty_stop)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
if (up->ier & UART_IER_THRI) {
up->ier &= ~UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
}
/*
* We only do this from uart_stop - if we run out of
* characters to send, we don't want to prevent the
* FIFO from emptying.
*/
if (up->port.type == PORT_16C950 && tty_stop) {
up->acr |= UART_ACR_TXDIS;
serial_icr_write(up, UART_ACR, up->acr);
}
}
static void transmit_chars(struct uart_8250_port *up);
static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
if (!(up->ier & UART_IER_THRI)) {
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
if (up->bugs & UART_BUG_TXEN) {
unsigned char lsr, iir;
lsr = serial_in(up, UART_LSR);
iir = serial_in(up, UART_IIR);
if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
transmit_chars(up);
}
}
/*
* We only do this from uart_start
*/
if (tty_start && up->port.type == PORT_16C950) {
up->acr &= ~UART_ACR_TXDIS;
serial_icr_write(up, UART_ACR, up->acr);
}
}
static void serial8250_stop_rx(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
up->ier &= ~UART_IER_RLSI;
up->port.read_status_mask &= ~UART_LSR_DR;
serial_out(up, UART_IER, up->ier);
}
static void serial8250_enable_ms(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
up->ier |= UART_IER_MSI;
serial_out(up, UART_IER, up->ier);
}
static _INLINE_ void
receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
{
struct tty_struct *tty = up->port.info->tty;
unsigned char ch, lsr = *status;
int max_count = 256;
char flag;
do {
/* The following is not allowed by the tty layer and
unsafe. It should be fixed ASAP */
if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
if (tty->low_latency) {
spin_unlock(&up->port.lock);
tty_flip_buffer_push(tty);
spin_lock(&up->port.lock);
}
/*
* If this failed then we will throw away the
* bytes but must do so to clear interrupts
*/
}
ch = serial_inp(up, UART_RX);
flag = TTY_NORMAL;
up->port.icount.rx++;
#ifdef CONFIG_SERIAL_8250_CONSOLE
/*
* Recover the break flag from console xmit
*/
if (up->port.line == up->port.cons->index) {
lsr |= up->lsr_break_flag;
up->lsr_break_flag = 0;
}
#endif
if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE))) {
/*
* For statistics only
*/
if (lsr & UART_LSR_BI) {
lsr &= ~(UART_LSR_FE | UART_LSR_PE);
up->port.icount.brk++;
/*
* We do the SysRQ and SAK checking
* here because otherwise the break
* may get masked by ignore_status_mask
* or read_status_mask.
*/
if (uart_handle_break(&up->port))
goto ignore_char;
} else if (lsr & UART_LSR_PE)
up->port.icount.parity++;
else if (lsr & UART_LSR_FE)
up->port.icount.frame++;
if (lsr & UART_LSR_OE)
up->port.icount.overrun++;
/*
* Mask off conditions which should be ignored.
*/
lsr &= up->port.read_status_mask;
if (lsr & UART_LSR_BI) {
DEBUG_INTR("handling break....");
flag = TTY_BREAK;
} else if (lsr & UART_LSR_PE)
flag = TTY_PARITY;
else if (lsr & UART_LSR_FE)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch, regs))
goto ignore_char;
uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
ignore_char:
lsr = serial_inp(up, UART_LSR);
} while ((lsr & UART_LSR_DR) && (max_count-- > 0));
spin_unlock(&up->port.lock);
tty_flip_buffer_push(tty);
spin_lock(&up->port.lock);
*status = lsr;
}
static _INLINE_ void transmit_chars(struct uart_8250_port *up)
{
struct circ_buf *xmit = &up->port.info->xmit;
int count;
if (up->port.x_char) {
serial_outp(up, UART_TX, up->port.x_char);
up->port.icount.tx++;
up->port.x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
serial8250_stop_tx(&up->port, 0);
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))
serial8250_stop_tx(&up->port, 0);
}
static _INLINE_ void check_modem_status(struct uart_8250_port *up)
{
int status;
status = serial_in(up, UART_MSR);
if ((status & UART_MSR_ANY_DELTA) == 0)
return;
if (status & UART_MSR_TERI)
up->port.icount.rng++;
if (status & UART_MSR_DDSR)
up->port.icount.dsr++;
if (status & UART_MSR_DDCD)
uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
if (status & UART_MSR_DCTS)
uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
wake_up_interruptible(&up->port.info->delta_msr_wait);
}
/*
* This handles the interrupt from one port.
*/
static inline void
serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
{
unsigned int status = serial_inp(up, UART_LSR);
DEBUG_INTR("status = %x...", status);
if (status & UART_LSR_DR)
receive_chars(up, &status, regs);
check_modem_status(up);
if (status & UART_LSR_THRE)
transmit_chars(up);
}
/*
* This is the serial driver's interrupt routine.
*
* Arjan thinks the old way was overly complex, so it got simplified.
* Alan disagrees, saying that need the complexity to handle the weird
* nature of ISA shared interrupts. (This is a special exception.)
*
* In order to handle ISA shared interrupts properly, we need to check
* that all ports have been serviced, and therefore the ISA interrupt
* line has been de-asserted.
*
* This means we need to loop through all ports. checking that they
* don't have an interrupt pending.
*/
static irqreturn_t serial8250_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
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)) {
spin_lock(&up->port.lock);
serial8250_handle_port(up, regs);
spin_unlock(&up->port.lock);
handled = 1;
end = NULL;
} else if (end == NULL)
end = l;
l = l->next;
if (l == i->head && pass_counter++ > PASS_LIMIT) {
/* If we hit this, we're dead. */
printk(KERN_ERR "serial8250: too much work for "
"irq%d\n", irq);
break;
}
} while (l != end);
spin_unlock(&i->lock);
DEBUG_INTR("end.\n");
return IRQ_RETVAL(handled);
}
/*
* To support ISA shared interrupts, we need to have one interrupt
* handler that ensures that the IRQ line has been deasserted
* before returning. Failing to do this will result in the IRQ
* line being stuck active, and, since ISA irqs are edge triggered,
* no more IRQs will be seen.
*/
static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
{
spin_lock_irq(&i->lock);
if (!list_empty(i->head)) {
if (i->head == &up->list)
i->head = i->head->next;
list_del(&up->list);
} else {
BUG_ON(i->head != &up->list);
i->head = NULL;
}
spin_unlock_irq(&i->lock);
}
static int serial_link_irq_chain(struct uart_8250_port *up)
{
struct irq_info *i = irq_lists + up->port.irq;
int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? SA_SHIRQ : 0;
spin_lock_irq(&i->lock);
if (i->head) {
list_add(&up->list, i->head);
spin_unlock_irq(&i->lock);
ret = 0;
} else {
INIT_LIST_HEAD(&up->list);
i->head = &up->list;
spin_unlock_irq(&i->lock);
ret = request_irq(up->port.irq, serial8250_interrupt,
irq_flags, "serial", i);
if (ret < 0)
serial_do_unlink(i, up);
}
return ret;
}
static void serial_unlink_irq_chain(struct uart_8250_port *up)
{
struct irq_info *i = irq_lists + up->port.irq;
BUG_ON(i->head == NULL);
if (list_empty(i->head))
free_irq(up->port.irq, i);
serial_do_unlink(i, up);
}
/*
* 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 timeout;
unsigned int iir;
iir = serial_in(up, UART_IIR);
if (!(iir & UART_IIR_NO_INT)) {
spin_lock(&up->port.lock);
serial8250_handle_port(up, NULL);
spin_unlock(&up->port.lock);
}
timeout = up->port.timeout;
timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
mod_timer(&up->timer, jiffies + timeout);
}
static unsigned int serial8250_tx_empty(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned long flags;
unsigned int ret;
spin_lock_irqsave(&up->port.lock, flags);
ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
spin_unlock_irqrestore(&up->port.lock, flags);
return ret;
}
static unsigned int serial8250_get_mctrl(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned char status;
unsigned int ret;
status = serial_in(up, UART_MSR);
ret = 0;
if (status & UART_MSR_DCD)
ret |= TIOCM_CAR;
if (status & UART_MSR_RI)
ret |= TIOCM_RNG;
if (status & UART_MSR_DSR)
ret |= TIOCM_DSR;
if (status & UART_MSR_CTS)
ret |= TIOCM_CTS;
return ret;
}
static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned char mcr = 0;
if (mctrl & TIOCM_RTS)
mcr |= UART_MCR_RTS;
if (mctrl & TIOCM_DTR)
mcr |= UART_MCR_DTR;
if (mctrl & TIOCM_OUT1)
mcr |= UART_MCR_OUT1;
if (mctrl & TIOCM_OUT2)
mcr |= UART_MCR_OUT2;
if (mctrl & TIOCM_LOOP)
mcr |= UART_MCR_LOOP;
mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
serial_out(up, UART_MCR, mcr);
}
static void serial8250_break_ctl(struct uart_port *port, int break_state)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
if (break_state == -1)
up->lcr |= UART_LCR_SBC;
else
up->lcr &= ~UART_LCR_SBC;
serial_out(up, UART_LCR, up->lcr);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static int serial8250_startup(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned long flags;
unsigned char lsr, iir;
int retval;
up->capabilities = uart_config[up->port.type].flags;
up->mcr = 0;
if (up->port.type == PORT_16C950) {
/* Wake up and initialize UART */
up->acr = 0;
serial_outp(up, UART_LCR, 0xBF);
serial_outp(up, UART_EFR, UART_EFR_ECB);
serial_outp(up, UART_IER, 0);
serial_outp(up, UART_LCR, 0);
serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
serial_outp(up, UART_LCR, 0xBF);
serial_outp(up, UART_EFR, UART_EFR_ECB);
serial_outp(up, UART_LCR, 0);
}
#ifdef CONFIG_SERIAL_8250_RSA
/*
* If this is an RSA port, see if we can kick it up to the
* higher speed clock.
*/
enable_rsa(up);
#endif
/*
* Clear the FIFO buffers and disable them.
* (they will be reeanbled in set_termios())
*/
serial8250_clear_fifos(up);
/*
* Clear the interrupt registers.
*/
(void) serial_inp(up, UART_LSR);
(void) serial_inp(up, UART_RX);
(void) serial_inp(up, UART_IIR);
(void) serial_inp(up, UART_MSR);
/*
* At this point, there's no way the LSR could still be 0xff;
* if it is, then bail out, because there's likely no UART
* here.
*/
if (!(up->port.flags & UPF_BUGGY_UART) &&
(serial_inp(up, UART_LSR) == 0xff)) {
printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
return -ENODEV;
}
/*
* For a XR16C850, we need to set the trigger levels
*/
if (up->port.type == PORT_16850) {
unsigned char fctr;
serial_outp(up, UART_LCR, 0xbf);
fctr = serial_inp(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX);
serial_outp(up, UART_TRG, UART_TRG_96);
serial_outp(up, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX);
serial_outp(up, UART_TRG, UART_TRG_96);
serial_outp(up, UART_LCR, 0);
}
/*
* 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)) {
unsigned int timeout = up->port.timeout;
timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
up->timer.data = (unsigned long)up;
mod_timer(&up->timer, jiffies + timeout);
} 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);
/*
* Do a quick test to see if we receive an
* interrupt when we enable the TX irq.
*/
serial_outp(up, UART_IER, UART_IER_THRI);
lsr = serial_in(up, UART_LSR);
iir = serial_in(up, UART_IIR);
serial_outp(up, UART_IER, 0);
if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
if (!(up->bugs & UART_BUG_TXEN)) {
up->bugs |= UART_BUG_TXEN;
pr_debug("ttyS%d - enabling bad tx status workarounds\n",
port->line);
}
} else {
up->bugs &= ~UART_BUG_TXEN;
}
spin_unlock_irqrestore(&up->port.lock, flags);
/*
* 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);
}
/*
* And clear the interrupt registers again for luck.
*/
(void) serial_inp(up, UART_LSR);
(void) serial_inp(up, UART_RX);
(void) serial_inp(up, UART_IIR);
(void) serial_inp(up, UART_MSR);
return 0;
}
static void serial8250_shutdown(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned long flags;
/*
* Disable interrupts from this port
*/
up->ier = 0;
serial_outp(up, UART_IER, 0);
spin_lock_irqsave(&up->port.lock, flags);
if (up->port.flags & UPF_FOURPORT) {
/* reset interrupts on the AST Fourport board */
inb((up->port.iobase & 0xfe0) | 0x1f);
up->port.mctrl |= TIOCM_OUT1;
} else
up->port.mctrl &= ~TIOCM_OUT2;
serial8250_set_mctrl(&up->port, up->port.mctrl);
spin_unlock_irqrestore(&up->port.lock, flags);
/*
* Disable break condition and FIFOs
*/
serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
serial8250_clear_fifos(up);
#ifdef CONFIG_SERIAL_8250_RSA
/*
* Reset the RSA board back to 115kbps compat mode.
*/
disable_rsa(up);
#endif
/*
* Read data port to reset things, and then unlink from
* the IRQ chain.
*/
(void) serial_in(up, UART_RX);
if (!is_real_interrupt(up->port.irq))
del_timer_sync(&up->timer);
else
serial_unlink_irq_chain(up);
}
static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
{
unsigned int quot;
/*
* Handle magic divisors for baud rates above baud_base on
* SMSC SuperIO chips.
*/
if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
baud == (port->uartclk/4))
quot = 0x8001;
else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
baud == (port->uartclk/8))
quot = 0x8002;
else
quot = uart_get_divisor(port, baud);
return quot;
}
static void
serial8250_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned char cval, fcr = 0;
unsigned long flags;
unsigned int baud, quot;
switch (termios->c_cflag & CSIZE) {
case CS5:
cval = UART_LCR_WLEN5;
break;
case CS6:
cval = UART_LCR_WLEN6;
break;
case CS7:
cval = UART_LCR_WLEN7;
break;
default:
case CS8:
cval = UART_LCR_WLEN8;
break;
}
if (termios->c_cflag & CSTOPB)
cval |= UART_LCR_STOP;
if (termios->c_cflag & PARENB)
cval |= UART_LCR_PARITY;
if (!(termios->c_cflag & PARODD))
cval |= UART_LCR_EPAR;
#ifdef CMSPAR
if (termios->c_cflag & CMSPAR)
cval |= UART_LCR_SPAR;
#endif
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
quot = serial8250_get_divisor(port, baud);
/*
* Oxford Semi 952 rev B workaround
*/
if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
quot ++;
if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
if (baud < 2400)
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
else
fcr = uart_config[up->port.type].fcr;
}
/*
* MCR-based auto flow control. When AFE is enabled, RTS will be
* deasserted when the receive FIFO contains more characters than
* the trigger, or the MCR RTS bit is cleared. In the case where
* the remote UART is not using CTS auto flow control, we must
* have sufficient FIFO entries for the latency of the remote
* UART to respond. IOW, at least 32 bytes of FIFO.
*/
if (up->capabilities & UART_CAP_AFE && up->port.fifosize >= 32) {
up->mcr &= ~UART_MCR_AFE;
if (termios->c_cflag & CRTSCTS)
up->mcr |= UART_MCR_AFE;
}
/*
* Ok, we're now changing the port state. Do it with
* interrupts disabled.
*/
spin_lock_irqsave(&up->port.lock, flags);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
if (termios->c_iflag & INPCK)
up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (termios->c_iflag & (BRKINT | PARMRK))
up->port.read_status_mask |= UART_LSR_BI;
/*
* Characteres to ignore
*/
up->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (termios->c_iflag & IGNBRK) {
up->port.ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
up->port.ignore_status_mask |= UART_LSR_OE;
}
/*
* ignore all characters if CREAD is not set
*/
if ((termios->c_cflag & CREAD) == 0)
up->port.ignore_status_mask |= UART_LSR_DR;
/*
* CTS flow control flag and modem status interrupts
*/
up->ier &= ~UART_IER_MSI;
if (UART_ENABLE_MS(&up->port, termios->c_cflag))
up->ier |= UART_IER_MSI;
if (up->capabilities & UART_CAP_UUE)
up->ier |= UART_IER_UUE | UART_IER_RTOIE;
serial_out(up, UART_IER, up->ier);
if (up->capabilities & UART_CAP_EFR) {
unsigned char efr = 0;
/*
* TI16C752/Startech hardware flow control. FIXME:
* - TI16C752 requires control thresholds to be set.
* - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
*/
if (termios->c_cflag & CRTSCTS)
efr |= UART_EFR_CTS;
serial_outp(up, UART_LCR, 0xBF);
serial_outp(up, UART_EFR, efr);
}
if (up->capabilities & UART_NATSEMI) {
/* Switch to bank 2 not bank 1, to avoid resetting EXCR2 */
serial_outp(up, UART_LCR, 0xe0);
} else {
serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
}
serial_outp(up, UART_DLL, quot & 0xff); /* LS of divisor */
serial_outp(up, UART_DLM, quot >> 8); /* MS of divisor */
/*
* 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);
}
static void
serial8250_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct uart_8250_port *p = (struct uart_8250_port *)port;
serial8250_set_sleep(p, state != 0);
if (p->pm)
p->pm(port, state, oldstate);
}
/*
* Resource handling.
*/
static int serial8250_request_std_resource(struct uart_8250_port *up)
{
unsigned int size = 8 << up->port.regshift;
int ret = 0;
switch (up->port.iotype) {
case UPIO_MEM:
if (!up->port.mapbase)
break;
if (!request_mem_region(up->port.mapbase, size, "serial")) {
ret = -EBUSY;
break;
}
if (up->port.flags & UPF_IOREMAP) {
up->port.membase = ioremap(up->port.mapbase, size);
if (!up->port.membase) {
release_mem_region(up->port.mapbase, size);
ret = -ENOMEM;
}
}
break;
case UPIO_HUB6:
case UPIO_PORT:
if (!request_region(up->port.iobase, size, "serial"))
ret = -EBUSY;
break;
}
return ret;
}
static void serial8250_release_std_resource(struct uart_8250_port *up)
{
unsigned int size = 8 << up->port.regshift;
switch (up->port.iotype) {
case UPIO_MEM:
if (!up->port.mapbase)
break;
if (up->port.flags & UPF_IOREMAP) {
iounmap(up->port.membase);
up->port.membase = NULL;
}
release_mem_region(up->port.mapbase, size);
break;
case UPIO_HUB6:
case UPIO_PORT:
release_region(up->port.iobase, size);
break;
}
}
static int serial8250_request_rsa_resource(struct uart_8250_port *up)
{
unsigned long start = UART_RSA_BASE << up->port.regshift;
unsigned int size = 8 << up->port.regshift;
int ret = 0;
switch (up->port.iotype) {
case UPIO_MEM:
ret = -EINVAL;
break;
case UPIO_HUB6:
case UPIO_PORT:
start += up->port.iobase;
if (!request_region(start, size, "serial-rsa"))
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_MEM:
break;
case UPIO_HUB6:
case UPIO_PORT:
release_region(up->port.iobase + offset, size);
break;
}
}
static void serial8250_release_port(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
serial8250_release_std_resource(up);
if (up->port.type == PORT_RSA)
serial8250_release_rsa_resource(up);
}
static int serial8250_request_port(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
int ret = 0;
ret = serial8250_request_std_resource(up);
if (ret == 0 && up->port.type == PORT_RSA) {
ret = serial8250_request_rsa_resource(up);
if (ret < 0)
serial8250_release_std_resource(up);
}
return ret;
}
static void serial8250_config_port(struct uart_port *port, int flags)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
int probeflags = PROBE_ANY;
int ret;
/*
* Don't probe for MCA ports on non-MCA machines.
*/
if (up->port.flags & UPF_BOOT_ONLYMCA && !MCA_bus)
return;
/*
* Find the region that we can probe for. This in turn
* tells us whether we can probe for the type of port.
*/
ret = serial8250_request_std_resource(up);
if (ret < 0)
return;
ret = serial8250_request_rsa_resource(up);
if (ret < 0)
probeflags &= ~PROBE_RSA;
if (flags & UART_CONFIG_TYPE)
autoconfig(up, probeflags);
if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
autoconfig_irq(up);
if (up->port.type != PORT_RSA && probeflags & PROBE_RSA)
serial8250_release_rsa_resource(up);
if (up->port.type == PORT_UNKNOWN)
serial8250_release_std_resource(up);
}
static int
serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (ser->irq >= NR_IRQS || ser->irq < 0 ||
ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
ser->type == PORT_STARTECH)
return -EINVAL;
return 0;
}
static const char *
serial8250_type(struct uart_port *port)
{
int type = port->type;
if (type >= ARRAY_SIZE(uart_config))
type = 0;
return uart_config[type].name;
}
static struct uart_ops serial8250_pops = {
.tx_empty = serial8250_tx_empty,
.set_mctrl = serial8250_set_mctrl,
.get_mctrl = serial8250_get_mctrl,
.stop_tx = serial8250_stop_tx,
.start_tx = serial8250_start_tx,
.stop_rx = serial8250_stop_rx,
.enable_ms = serial8250_enable_ms,
.break_ctl = serial8250_break_ctl,
.startup = serial8250_startup,
.shutdown = serial8250_shutdown,
.set_termios = serial8250_set_termios,
.pm = serial8250_pm,
.type = serial8250_type,
.release_port = serial8250_release_port,
.request_port = serial8250_request_port,
.config_port = serial8250_config_port,
.verify_port = serial8250_verify_port,
};
static struct uart_8250_port serial8250_ports[UART_NR];
static void __init serial8250_isa_init_ports(void)
{
struct uart_8250_port *up;
static int first = 1;
int i;
if (!first)
return;
first = 0;
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
up->port.line = i;
spin_lock_init(&up->port.lock);
init_timer(&up->timer);
up->timer.function = serial8250_timeout;
/*
* ALPHA_KLUDGE_MCR needs to be killed.
*/
up->mcr_mask = ~ALPHA_KLUDGE_MCR;
up->mcr_force = ALPHA_KLUDGE_MCR;
up->port.ops = &serial8250_pops;
}
for (i = 0, up = serial8250_ports; i < ARRAY_SIZE(old_serial_port);
i++, up++) {
up->port.iobase = old_serial_port[i].port;
up->port.irq = irq_canonicalize(old_serial_port[i].irq);
up->port.uartclk = old_serial_port[i].baud_base * 16;
up->port.flags = old_serial_port[i].flags;
up->port.hub6 = old_serial_port[i].hub6;
up->port.membase = old_serial_port[i].iomem_base;
up->port.iotype = old_serial_port[i].io_type;
up->port.regshift = old_serial_port[i].iomem_reg_shift;
if (share_irqs)
up->port.flags |= UPF_SHARE_IRQ;
}
}
static void __init
serial8250_register_ports(struct uart_driver *drv, struct device *dev)
{
int i;
serial8250_isa_init_ports();
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
up->port.dev = dev;
uart_add_one_port(drv, &up->port);
}
}
#ifdef CONFIG_SERIAL_8250_CONSOLE
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
/*
* Wait for transmitter & holding register to empty
*/
static inline void wait_for_xmitr(struct uart_8250_port *up)
{
unsigned int status, tmout = 10000;
/* Wait up to 10ms for the character(s) to be sent. */
do {
status = serial_in(up, UART_LSR);
if (status & UART_LSR_BI)
up->lsr_break_flag = UART_LSR_BI;
if (--tmout == 0)
break;
udelay(1);
} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
tmout = 1000000;
while (--tmout &&
((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
udelay(1);
}
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*
* The console_lock must be held when we get here.
*/
static void
serial8250_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_8250_port *up = &serial8250_ports[co->index];
unsigned int ier;
int i;
/*
* First save the UER 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);
/*
* Now, do each character
*/
for (i = 0; i < count; i++, s++) {
wait_for_xmitr(up);
/*
* Send the character out.
* If a LF, also do CR...
*/
serial_out(up, UART_TX, *s);
if (*s == 10) {
wait_for_xmitr(up);
serial_out(up, UART_TX, 13);
}
}
/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
wait_for_xmitr(up);
serial_out(up, UART_IER, ier);
}
static int serial8250_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (co->index >= UART_NR)
co->index = 0;
port = &serial8250_ports[co->index].port;
if (!port->iobase && !port->membase)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver serial8250_reg;
static struct console serial8250_console = {
.name = "ttyS",
.write = serial8250_console_write,
.device = uart_console_device,
.setup = serial8250_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &serial8250_reg,
};
static int __init serial8250_console_init(void)
{
serial8250_isa_init_ports();
register_console(&serial8250_console);
return 0;
}
console_initcall(serial8250_console_init);
static int __init find_port(struct uart_port *p)
{
int line;
struct uart_port *port;
for (line = 0; line < UART_NR; line++) {
port = &serial8250_ports[line].port;
if (p->iotype == port->iotype &&
p->iobase == port->iobase &&
p->membase == port->membase)
return line;
}
return -ENODEV;
}
int __init serial8250_start_console(struct uart_port *port, char *options)
{
int line;
line = find_port(port);
if (line < 0)
return -ENODEV;
add_preferred_console("ttyS", line, options);
printk("Adding console on ttyS%d at %s 0x%lx (options '%s')\n",
line, port->iotype == UPIO_MEM ? "MMIO" : "I/O port",
port->iotype == UPIO_MEM ? (unsigned long) port->mapbase :
(unsigned long) port->iobase, options);
if (!(serial8250_console.flags & CON_ENABLED)) {
serial8250_console.flags &= ~CON_PRINTBUFFER;
register_console(&serial8250_console);
}
return line;
}
#define SERIAL8250_CONSOLE &serial8250_console
#else
#define SERIAL8250_CONSOLE NULL
#endif
static struct uart_driver serial8250_reg = {
.owner = THIS_MODULE,
.driver_name = "serial",
.devfs_name = "tts/",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = UART_NR,
.cons = SERIAL8250_CONSOLE,
};
int __init early_serial_setup(struct uart_port *port)
{
if (port->line >= ARRAY_SIZE(serial8250_ports))
return -ENODEV;
serial8250_isa_init_ports();
serial8250_ports[port->line].port = *port;
serial8250_ports[port->line].port.ops = &serial8250_pops;
return 0;
}
/**
* serial8250_suspend_port - suspend one serial port
* @line: serial line number
* @level: the level of port suspension, as per uart_suspend_port
*
* 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
* @level: the level of port resumption, as per uart_resume_port
*
* Resume one serial port.
*/
void serial8250_resume_port(int line)
{
uart_resume_port(&serial8250_reg, &serial8250_ports[line].port);
}
/*
* Register a set of serial devices attached to a platform device. The
* list is terminated with a zero flags entry, which means we expect
* all entries to have at least UPF_BOOT_AUTOCONF set.
*/
static int __devinit serial8250_probe(struct device *dev)
{
struct plat_serial8250_port *p = dev->platform_data;
struct uart_port port;
int ret, i;
memset(&port, 0, sizeof(struct uart_port));
for (i = 0; p && p->flags != 0; p++, i++) {
port.iobase = p->iobase;
port.membase = p->membase;
port.irq = p->irq;
port.uartclk = p->uartclk;
port.regshift = p->regshift;
port.iotype = p->iotype;
port.flags = p->flags;
port.mapbase = p->mapbase;
port.hub6 = p->hub6;
port.dev = dev;
if (share_irqs)
port.flags |= UPF_SHARE_IRQ;
ret = serial8250_register_port(&port);
if (ret < 0) {
dev_err(dev, "unable to register port at index %d "
"(IO%lx MEM%lx IRQ%d): %d\n", i,
p->iobase, p->mapbase, p->irq, ret);
}
}
return 0;
}
/*
* Remove serial ports registered against a platform device.
*/
static int __devexit serial8250_remove(struct device *dev)
{
int i;
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
if (up->port.dev == dev)
serial8250_unregister_port(i);
}
return 0;
}
static int serial8250_suspend(struct device *dev, pm_message_t state, u32 level)
{
int i;
if (level != SUSPEND_DISABLE)
return 0;
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
if (up->port.type != PORT_UNKNOWN && up->port.dev == dev)
uart_suspend_port(&serial8250_reg, &up->port);
}
return 0;
}
static int serial8250_resume(struct device *dev, u32 level)
{
int i;
if (level != RESUME_ENABLE)
return 0;
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
if (up->port.type != PORT_UNKNOWN && up->port.dev == dev)
uart_resume_port(&serial8250_reg, &up->port);
}
return 0;
}
static struct device_driver serial8250_isa_driver = {
.name = "serial8250",
.bus = &platform_bus_type,
.probe = serial8250_probe,
.remove = __devexit_p(serial8250_remove),
.suspend = serial8250_suspend,
.resume = serial8250_resume,
};
/*
* This "device" covers _all_ ISA 8250-compatible serial devices listed
* in the table in include/asm/serial.h
*/
static struct platform_device *serial8250_isa_devs;
/*
* serial8250_register_port and serial8250_unregister_port allows for
* 16x50 serial ports to be configured at run-time, to support PCMCIA
* modems and PCI multiport cards.
*/
static DECLARE_MUTEX(serial_sem);
static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
{
int i;
/*
* First, find a port entry which matches.
*/
for (i = 0; i < UART_NR; i++)
if (uart_match_port(&serial8250_ports[i].port, port))
return &serial8250_ports[i];
/*
* We didn't find a matching entry, so look for the first
* free entry. We look for one which hasn't been previously
* used (indicated by zero iobase).
*/
for (i = 0; i < UART_NR; i++)
if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
serial8250_ports[i].port.iobase == 0)
return &serial8250_ports[i];
/*
* That also failed. Last resort is to find any entry which
* doesn't have a real port associated with it.
*/
for (i = 0; i < UART_NR; i++)
if (serial8250_ports[i].port.type == PORT_UNKNOWN)
return &serial8250_ports[i];
return NULL;
}
/**
* serial8250_register_port - register a serial port
* @port: serial port template
*
* Configure the serial port specified by the request. If the
* port exists and is in use, it is hung up and unregistered
* first.
*
* The port is then probed and if necessary the IRQ is autodetected
* If this fails an error is returned.
*
* On success the port is ready to use and the line number is returned.
*/
int serial8250_register_port(struct uart_port *port)
{
struct uart_8250_port *uart;
int ret = -ENOSPC;
if (port->uartclk == 0)
return -EINVAL;
down(&serial_sem);
uart = serial8250_find_match_or_unused(port);
if (uart) {
uart_remove_one_port(&serial8250_reg, &uart->port);
uart->port.iobase = port->iobase;
uart->port.membase = port->membase;
uart->port.irq = port->irq;
uart->port.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;
if (port->dev)
uart->port.dev = port->dev;
ret = uart_add_one_port(&serial8250_reg, &uart->port);
if (ret == 0)
ret = uart->port.line;
}
up(&serial_sem);
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];
down(&serial_sem);
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;
}
up(&serial_sem);
}
EXPORT_SYMBOL(serial8250_unregister_port);
static int __init serial8250_init(void)
{
int ret, i;
printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ "
"%d ports, IRQ sharing %sabled\n", (int) UART_NR,
share_irqs ? "en" : "dis");
for (i = 0; i < NR_IRQS; i++)
spin_lock_init(&irq_lists[i].lock);
ret = uart_register_driver(&serial8250_reg);
if (ret)
goto out;
serial8250_isa_devs = platform_device_register_simple("serial8250",
-1, NULL, 0);
if (IS_ERR(serial8250_isa_devs)) {
ret = PTR_ERR(serial8250_isa_devs);
goto unreg;
}
serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
ret = driver_register(&serial8250_isa_driver);
if (ret == 0)
goto out;
platform_device_unregister(serial8250_isa_devs);
unreg:
uart_unregister_driver(&serial8250_reg);
out:
return ret;
}
static void __exit serial8250_exit(void)
{
struct platform_device *isa_dev = serial8250_isa_devs;
/*
* This tells serial8250_unregister_port() not to re-register
* the ports (thereby making serial8250_isa_driver permanently
* in use.)
*/
serial8250_isa_devs = NULL;
driver_unregister(&serial8250_isa_driver);
platform_device_unregister(isa_dev);
uart_unregister_driver(&serial8250_reg);
}
module_init(serial8250_init);
module_exit(serial8250_exit);
EXPORT_SYMBOL(serial8250_suspend_port);
EXPORT_SYMBOL(serial8250_resume_port);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic 8250/16x50 serial driver $Revision: 1.90 $");
module_param(share_irqs, uint, 0644);
MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
" (unsafe)");
#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);
/**
* register_serial - configure a 16x50 serial port at runtime
* @req: request structure
*
* Configure the serial port specified by the request. If the
* port exists and is in use an error is returned. If the port
* is not currently in the table it is added.
*
* 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.
*
* Note: this function is deprecated - use serial8250_register_port
* instead.
*/
int register_serial(struct serial_struct *req)
{
struct uart_port port;
port.iobase = req->port;
port.membase = req->iomem_base;
port.irq = req->irq;
port.uartclk = req->baud_base * 16;
port.fifosize = req->xmit_fifo_size;
port.regshift = req->iomem_reg_shift;
port.iotype = req->io_type;
port.flags = req->flags | UPF_BOOT_AUTOCONF;
port.mapbase = req->iomap_base;
port.dev = NULL;
if (share_irqs)
port.flags |= UPF_SHARE_IRQ;
if (HIGH_BITS_OFFSET)
port.iobase |= (long) req->port_high << HIGH_BITS_OFFSET;
/*
* If a clock rate wasn't specified by the low level driver, then
* default to the standard clock rate. This should be 115200 (*16)
* and should not depend on the architecture's BASE_BAUD definition.
* However, since this API will be deprecated, it's probably a
* better idea to convert the drivers to use the new API
* (serial8250_register_port and serial8250_unregister_port).
*/
if (port.uartclk == 0) {
printk(KERN_WARNING
"Serial: registering port at [%08x,%08lx,%p] irq %d with zero baud_base\n",
port.iobase, port.mapbase, port.membase, port.irq);
printk(KERN_WARNING "Serial: see %s:%d for more information\n",
__FILE__, __LINE__);
dump_stack();
/*
* Fix it up for now, but this is only a temporary measure.
*/
port.uartclk = BASE_BAUD * 16;
}
return serial8250_register_port(&port);
}
EXPORT_SYMBOL(register_serial);
/**
* unregister_serial - 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 our local PM control.
*
* Note: this function is deprecated - use serial8250_unregister_port
* instead.
*/
void unregister_serial(int line)
{
serial8250_unregister_port(line);
}
EXPORT_SYMBOL(unregister_serial);
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