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historical/gems-kernel.git/source/THIRDPARTY/linux-old/drivers/char/serial.c

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add linux kernel source dependency/ignore compiler
2024-01-26 23:19:05 +00:00
/*
* linux/kernel/serial.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Extensively rewritten by Theodore Ts'o, 8/16/92 -- 9/14/92. Now
* much more extensible to support other serial cards based on the
* 16450/16550A UART's. Added support for the AST FourPort and the
* Accent Async board.
*
* set_serial_info fixed to set the flags, custom divisor, and uart
* type fields. Fix suggested by Michael K. Johnson 12/12/92.
*
* This module exports the following rs232 io functions:
*
* long rs_init(long);
* int rs_open(struct tty_struct * tty, struct file * filp)
*/
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/interrupt.h>
#include <linux/config.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/segment.h>
#include <asm/bitops.h>
/*
* Serial driver configuration section. Here are the various options:
*
* CONFIG_AUTO_IRQ
* Enables automatic IRQ detection. I've put in some
* fixes to this which should make this work much more
* cleanly than it used to in 0.98pl2-6. It should be
* much less vulnerable to false IRQs now.
*
* CONFIG_AST_FOURPORT
* Enables support for the AST Fourport serial port.
*
* CONFIG_ACCENT_ASYNC
* Enables support for the Accent Async 4 port serial
* port.
*
* CONFIG_HUB6
* Enables support for the venerable Bell Technologies
* HUB6 card.
*/
#undef ISR_HACK
/*
* rs_event - Bitfield of serial lines that events pending
* to be processed at the next clock tick.
* IRQ_timeout - How long the timeout should be for each IRQ
* should be after the IRQ has been active.
* IRQ_timer - Array of timeout values for each interrupt IRQ.
* This is based on jiffies; not offsets.
*
* We assume here that int's are 32 bits, so an array of two gives us
* 64 lines, which is the maximum we can support.
*/
static int rs_event[2];
static struct async_struct *IRQ_ports[16];
static int IRQ_active;
static unsigned long IRQ_timer[16];
static int IRQ_timeout[16];
static volatile int rs_irq_triggered;
static volatile int rs_triggered;
static int rs_wild_int_mask;
static void autoconfig(struct async_struct * info);
static void change_speed(unsigned int line);
/*
* This assumes you have a 1.8432 MHz clock for your UART.
*
* It'd be nice if someone built a serial card with a 24.576 MHz
* clock, since the 16550A is capable of handling a top speed of 1.5
* megabits/second; but this requires the faster clock.
*/
#define BASE_BAUD ( 1843200 / 16 )
#ifdef CONFIG_AUTO_IRQ
#define AUTO_IRQ_FLAG ASYNC_AUTO_IRQ
#else
#define AUTO_IRQ_FLAG 0
#endif
/* Standard COM flags (except for COM4, because of the 8514 problem) */
#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | AUTO_IRQ_FLAG)
#define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | AUTO_IRQ_FLAG)
#ifdef CONFIG_AST_FOURPORT
#define FOURPORT_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_FOURPORT | AUTO_IRQ_FLAG)
#else
#define FOURPORT_FLAGS (ASYNC_FOURPORT | AUTO_IRQ_FLAG)
#endif
#ifdef CONFIG_ACCENT_ASYNC
#define ACCENT_FLAGS (ASYNC_BOOT_AUTOCONF | AUTO_IRQ_FLAG)
#else
#define ACCENT_FLAGS AUTO_IRQ_FLAG
#endif
#ifdef CONFIG_BOCA
#define BOCA_FLAGS (ASYNC_BOOT_AUTOCONF | AUTO_IRQ_FLAG)
#else
#define BOCA_FLAGS AUTO_IRQ_FLAG
#endif
#ifdef CONFIG_HUB6
#define HUB6_FLAGS (ASYNC_BOOT_AUTOCONF)
#else
#define HUB6_FLAGS 0
#endif
/*
* The following define the access methods for the HUB6 card. All
* access is through two ports for all 24 possible chips. The card is
* selected through the high 2 bits, the port on that card with the
* "middle" 3 bits, and the register on that port with the bottom
* 3 bits.
*
* While the access port and interrupt is configurable, the default
* port locations are 0x302 for the port control register, and 0x303
* for the data read/write register. Normally, the interrupt is at irq3
* but can be anything from 3 to 7 inclusive. Note tht using 3 will
* require disabling com2.
*/
#define C_P(card,port) (((card)<<6|(port)<<3) + 1)
struct async_struct rs_table[] = {
/* UART CLK PORT IRQ FLAGS */
{ BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS }, /* ttyS0 */
{ BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS }, /* ttyS1 */
{ BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS }, /* ttyS2 */
{ BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS }, /* ttyS3 */
{ BASE_BAUD, 0x1A0, 9, FOURPORT_FLAGS }, /* ttyS4 */
{ BASE_BAUD, 0x1A8, 9, FOURPORT_FLAGS }, /* ttyS5 */
{ BASE_BAUD, 0x1B0, 9, FOURPORT_FLAGS }, /* ttyS6 */
{ BASE_BAUD, 0x1B8, 9, FOURPORT_FLAGS }, /* ttyS7 */
{ BASE_BAUD, 0x2A0, 5, FOURPORT_FLAGS }, /* ttyS8 */
{ BASE_BAUD, 0x2A8, 5, FOURPORT_FLAGS }, /* ttyS9 */
{ BASE_BAUD, 0x2B0, 5, FOURPORT_FLAGS }, /* ttyS10 */
{ BASE_BAUD, 0x2B8, 5, FOURPORT_FLAGS }, /* ttyS11 */
{ BASE_BAUD, 0x330, 4, ACCENT_FLAGS }, /* ttyS12 */
{ BASE_BAUD, 0x338, 4, ACCENT_FLAGS }, /* ttyS13 */
{ BASE_BAUD, 0x000, 0, 0 }, /* ttyS14 (spare; user configurable) */
{ BASE_BAUD, 0x000, 0, 0 }, /* ttyS15 (spare; user configurable) */
{ BASE_BAUD, 0x100, 12, BOCA_FLAGS }, /* ttyS16 */
{ BASE_BAUD, 0x108, 12, BOCA_FLAGS }, /* ttyS17 */
{ BASE_BAUD, 0x110, 12, BOCA_FLAGS }, /* ttyS18 */
{ BASE_BAUD, 0x118, 12, BOCA_FLAGS }, /* ttyS19 */
{ BASE_BAUD, 0x120, 12, BOCA_FLAGS }, /* ttyS20 */
{ BASE_BAUD, 0x128, 12, BOCA_FLAGS }, /* ttyS21 */
{ BASE_BAUD, 0x130, 12, BOCA_FLAGS }, /* ttyS22 */
{ BASE_BAUD, 0x138, 12, BOCA_FLAGS }, /* ttyS23 */
{ BASE_BAUD, 0x140, 12, BOCA_FLAGS }, /* ttyS24 */
{ BASE_BAUD, 0x148, 12, BOCA_FLAGS }, /* ttyS25 */
{ BASE_BAUD, 0x150, 12, BOCA_FLAGS }, /* ttyS26 */
{ BASE_BAUD, 0x158, 12, BOCA_FLAGS }, /* ttyS27 */
{ BASE_BAUD, 0x160, 12, BOCA_FLAGS }, /* ttyS28 */
{ BASE_BAUD, 0x168, 12, BOCA_FLAGS }, /* ttyS29 */
{ BASE_BAUD, 0x170, 12, BOCA_FLAGS }, /* ttyS30 */
{ BASE_BAUD, 0x178, 12, BOCA_FLAGS }, /* ttyS31 */
/* You can have up to four HUB6's in the system, but I've only
* included two cards here for a total of twelve ports.
*/
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,0) }, /* ttyS32 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,1) }, /* ttyS33 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,2) }, /* ttyS34 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,3) }, /* ttyS35 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,4) }, /* ttyS36 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(0,5) }, /* ttyS37 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,0) }, /* ttyS32 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,1) }, /* ttyS33 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,2) }, /* ttyS34 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,3) }, /* ttyS35 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,4) }, /* ttyS36 */
{ BASE_BAUD, 0x302, 3, HUB6_FLAGS, C_P(1,5) }, /* ttyS37 */
};
#define NR_PORTS (sizeof(rs_table)/sizeof(struct async_struct))
/*
* This is used to figure out the divsor speeds and the timeouts
*/
static int baud_table[] = {
0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
9600, 19200, 38400, 57600, 115200, 0 };
static void rs_throttle(struct tty_struct * tty, int status);
static inline unsigned int serial_in(struct async_struct *info, int offset)
{
if (info->hub6) {
outb(info->hub6 - 1 + offset, info->port);
return inb(info->port+1);
} else
return inb(info->port + offset);
}
static inline unsigned int serial_inp(struct async_struct *info, int offset)
{
if (info->hub6) {
outb(info->hub6 - 1 + offset, info->port);
return inb_p(info->port+1);
} else
return inb_p(info->port + offset);
}
static inline void serial_out(struct async_struct *info, int offset, int value)
{
if (info->hub6) {
outb(info->hub6 - 1 + offset, info->port);
outb(value, info->port+1);
} else
outb(value, info->port+offset);
}
static inline void serial_outp(struct async_struct *info, int offset,
int value)
{
if (info->hub6) {
outb(info->hub6 - 1 + offset, info->port);
outb_p(value, info->port+1);
} else
outb_p(value, info->port+offset);
}
/*
* ------------------------------------------------------------
* rs_stop() and rs_start()
*
* This routines are called before setting or resetting tty->stopped.
* They enable or disable transmitter interrupts, as necessary.
* ------------------------------------------------------------
*/
static void rs_stop(struct tty_struct *tty)
{
struct async_struct *info;
info = rs_table + DEV_TO_SL(tty->line);
info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
#ifdef ISR_HACK
serial_out(info, UART_IER, info->IER);
#endif
}
static void rs_start(struct tty_struct *tty)
{
struct async_struct *info;
info = rs_table + DEV_TO_SL(tty->line);
info->IER = (UART_IER_MSI | UART_IER_RLSI |
UART_IER_THRI | UART_IER_RDI);
#ifdef ISR_HACK
serial_out(info, UART_IER, info->IER);
#endif
}
/*
* ----------------------------------------------------------------------
*
* Here starts the interrupt handling routines. All of the following
* subroutines are declared as inline and are folded into
* rs_interrupt(). They were separated out for readability's sake.
*
* Note: rs_interrupt() is a "fast" interrupt, which means that it
* runs with interrupts turned off. People who may want to modify
* rs_interrupt() should try to keep the interrupt handler as fast as
* possible. After you are done making modifications, it is not a bad
* idea to do:
*
* gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
*
* and look at the resulting assemble code in serial.s.
*
* - Ted Ts'o (tytso@mit.edu), 7-Mar-93
* -----------------------------------------------------------------------
*/
/*
* This is the serial driver's interrupt routine while we are probing
* for submarines.
*/
static void rs_probe(int irq)
{
rs_irq_triggered = irq;
rs_triggered |= 1 << irq;
return;
}
/*
* This routine is used by the interrupt handler to schedule
* processing in the software interrupt portion of the driver.
*/
static inline void rs_sched_event(struct async_struct *info,
int event)
{
info->event |= 1 << event;
set_bit(info->line, rs_event);
mark_bh(SERIAL_BH);
}
static inline void receive_chars(struct async_struct *info,
int *status)
{
struct tty_queue * queue;
int head, tail, ch;
/*
* Just like the LEFT(x) macro, except it uses the loal tail
* and head variables.
*/
#define VLEFT ((tail-head-1)&(TTY_BUF_SIZE-1))
queue = &info->tty->read_q;
head = queue->head;
tail = queue->tail;
do {
ch = serial_inp(info, UART_RX);
/*
* There must be at least 2 characters
* free in the queue; otherwise we punt.
*/
if (VLEFT < 2)
break;
if (*status & info->read_status_mask) {
set_bit(head, &info->tty->readq_flags);
if (*status & (UART_LSR_BI)) {
queue->buf[head++]= TTY_BREAK;
rs_sched_event(info, RS_EVENT_BREAK);
} else if (*status & UART_LSR_PE)
queue->buf[head++]= TTY_PARITY;
else if (*status & UART_LSR_FE)
queue->buf[head++]= TTY_FRAME;
else if (*status & UART_LSR_OE)
queue->buf[head++]= TTY_OVERRUN;
head &= TTY_BUF_SIZE-1;
}
queue->buf[head++] = ch;
head &= TTY_BUF_SIZE-1;
} while ((*status = serial_inp(info, UART_LSR)) & UART_LSR_DR);
queue->head = head;
if ((VLEFT < RQ_THRESHOLD_LW) && !set_bit(TTY_RQ_THROTTLED,
&info->tty->flags))
rs_throttle(info->tty, TTY_THROTTLE_RQ_FULL);
rs_sched_event(info, RS_EVENT_READ_PROCESS);
#ifdef SERIAL_DEBUG_INTR
printk("DR...");
#endif
}
static inline void transmit_chars(struct async_struct *info, int *done_work)
{
struct tty_queue * queue;
int head, tail, count;
queue = &info->tty->write_q;
head = queue->head;
tail = queue->tail;
if (head==tail && !info->x_char) {
info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
#ifdef ISR_HACK
serial_out(info, UART_IER, info->IER);
#endif
return;
}
count = info->xmit_fifo_size;
if (info->x_char) {
serial_outp(info, UART_TX, info->x_char);
info->x_char = 0;
count--;
}
while (count-- && (tail != head)) {
serial_outp(info, UART_TX, queue->buf[tail++]);
tail &= TTY_BUF_SIZE-1;
}
queue->tail = tail;
if (VLEFT > WAKEUP_CHARS) {
rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
if (info->tty->write_data_cnt) {
set_bit(info->tty->line, &tty_check_write);
mark_bh(TTY_BH);
}
}
#ifdef SERIAL_DEBUG_INTR
printk("THRE...");
#endif
(*done_work)++;
}
static inline int check_modem_status(struct async_struct *info)
{
int status;
status = serial_in(info, UART_MSR);
if ((status & UART_MSR_DDCD) && !C_CLOCAL(info->tty)) {
#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
printk("ttys%d CD now %s...", info->line,
(status & UART_MSR_DCD) ? "on" : "off");
#endif
if (status & UART_MSR_DCD)
rs_sched_event(info, RS_EVENT_OPEN_WAKEUP);
else if (!((info->flags & ASYNC_CALLOUT_ACTIVE) &&
(info->flags & ASYNC_CALLOUT_NOHUP))) {
#ifdef SERIAL_DEBUG_OPEN
printk("scheduling hangup...");
#endif
rs_sched_event(info, RS_EVENT_HANGUP);
}
}
if (C_CRTSCTS(info->tty)) {
if (info->tty->hw_stopped) {
if (status & UART_MSR_CTS) {
#ifdef SERIAL_DEBUG_INTR
printk("CTS tx start...");
#endif
info->tty->hw_stopped = 0;
rs_start(info->tty);
return 1;
}
} else {
if (!(status & UART_MSR_CTS)) {
#ifdef SERIAL_DEBUG_INTR
printk("CTS tx stop...");
#endif
info->tty->hw_stopped = 1;
rs_stop(info->tty);
}
}
}
return 0;
}
static inline void figure_RS_timer(void)
{
int timeout = 6000; /* 60 seconds; really big :-) */
int i, mask;
if (!IRQ_active)
return;
for (i=0, mask = 1; mask <= IRQ_active; i++, mask <<= 1) {
if (!(mask & IRQ_active))
continue;
if (IRQ_timer[i] < timeout)
timeout = IRQ_timer[i];
}
timer_table[RS_TIMER].expires = jiffies + timeout;
timer_active |= 1 << RS_TIMER;
}
/*
* This is the serial driver's generic interrupt routine
*/
static void rs_interrupt(int irq)
{
int status;
struct async_struct * info;
int done, done_work, pass_number, recheck_count;
rs_irq_triggered = irq;
rs_triggered |= 1 << irq;
info = IRQ_ports[irq];
done = 1;
done_work = 0;
pass_number = 0;
while (info) {
if (info->tty &&
info->tty->termios &&
(!pass_number ||
!(serial_inp(info, UART_IIR) & UART_IIR_NO_INT))) {
done = 0;
status = serial_inp(info, UART_LSR);
if (status & UART_LSR_DR) {
receive_chars(info, &status);
done_work++;
}
recheck_count = 0;
recheck_write:
if (status & UART_LSR_THRE) {
wake_up_interruptible(&info->xmit_wait);
if (!info->tty->stopped &&
!info->tty->hw_stopped)
transmit_chars(info, &done_work);
}
if (check_modem_status(info) &&
(recheck_count++ <= 64))
goto recheck_write;
#ifdef SERIAL_DEBUG_INTR
if (recheck_count > 16)
printk("recheck_count = %d\n", recheck_count);
#endif
}
#ifdef ISR_HACK
serial_outp(info, UART_IER, 0);
serial_out(info, UART_IER, info->IER);
#endif
info = info->next_port;
if (!info && !done) {
info = IRQ_ports[irq];
done = 1;
if (pass_number++ > 64)
break; /* Prevent infinite loops */
}
}
if ((info = IRQ_ports[irq]) != NULL) {
#ifdef 0
do {
serial_outp(info, UART_IER, 0);
serial_out(info, UART_IER, info->IER);
info = info->next_port;
} while (info);
#endif
if (irq && !done_work)
IRQ_timer[irq] = jiffies + 1500;
else
IRQ_timer[irq] = jiffies + IRQ_timeout[irq];
IRQ_active |= 1 << irq;
}
figure_RS_timer();
}
/*
* -------------------------------------------------------------------
* Here ends the serial interrupt routines.
* -------------------------------------------------------------------
*/
/*
* This routine is called when we receive a break on a serial line.
* It is executed out of the software interrupt routine.
*/
static inline void handle_rs_break(struct async_struct *info)
{
if (info->flags & ASYNC_SAK)
do_SAK(info->tty);
if (!I_IGNBRK(info->tty) && I_BRKINT(info->tty)) {
flush_input(info->tty);
flush_output(info->tty);
if (info->tty->pgrp > 0)
kill_pg(info->tty->pgrp, SIGINT,1);
}
}
/*
* This routine is used to handle the "bottom half" processing for the
* serial driver, known also the "software interrupt" processing.
* This processing is done at the kernel interrupt level, after the
* rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON. This
* is where time-consuming activities which can not be done in the
* interrupt driver proper are done; the interrupt driver schedules
* them using rs_sched_event(), and they get done here.
*/
static void do_softint(void *unused)
{
int i;
struct async_struct *info;
for (i = 0, info = rs_table; i < NR_PORTS; i++,info++) {
if (clear_bit(i, rs_event)) {
if (!info->tty)
continue;
if (clear_bit(RS_EVENT_READ_PROCESS, &info->event)) {
TTY_READ_FLUSH(info->tty);
}
if (clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
wake_up_interruptible(&info->tty->write_q.proc_list);
}
if (clear_bit(RS_EVENT_HANGUP, &info->event)) {
tty_hangup(info->tty);
wake_up_interruptible(&info->open_wait);
info->flags &= ~(ASYNC_NORMAL_ACTIVE|
ASYNC_CALLOUT_ACTIVE);
}
if (clear_bit(RS_EVENT_BREAK, &info->event))
handle_rs_break(info);
if (clear_bit(RS_EVENT_OPEN_WAKEUP, &info->event)) {
wake_up_interruptible(&info->open_wait);
}
}
}
}
/*
* This subroutine is called when the RS_TIMER goes off. It is used
* by the serial driver to run the rs_interrupt routine at certain
* intervals, either because a serial interrupt might have been lost,
* or because (in the case of IRQ=0) the serial port does not have an
* interrupt, and is being checked only via the timer interrupts.
*/
static void rs_timer(void)
{
int i, mask;
int timeout = 0;
for (i = 0, mask = 1; mask <= IRQ_active; i++, mask <<= 1) {
if ((mask & IRQ_active) && (IRQ_timer[i] <= jiffies)) {
IRQ_active &= ~mask;
cli();
#ifdef SERIAL_DEBUG_TIMER
printk("rs_timer: rs_interrupt(%d)...", i);
#endif
rs_interrupt(i);
sti();
}
if (mask & IRQ_active) {
if (!timeout || (IRQ_timer[i] < timeout))
timeout = IRQ_timer[i];
}
}
if (timeout) {
timer_table[RS_TIMER].expires = timeout;
timer_active |= 1 << RS_TIMER;
}
}
/*
* ---------------------------------------------------------------
* Low level utility subroutines for the serial driver: routines to
* figure out the appropriate timeout for an interrupt chain, routines
* to initialize and startup a serial port, and routines to shutdown a
* serial port. Useful stuff like that.
* ---------------------------------------------------------------
*/
/*
* Grab all interrupts in preparation for doing an automatic irq
* detection. dontgrab is a mask of irq's _not_ to grab. Returns a
* mask of irq's which were grabbed and should therefore be freed
* using free_all_interrupts().
*/
static int grab_all_interrupts(int dontgrab)
{
int irq_lines = 0;
int i, mask;
struct sigaction sa;
sa.sa_handler = rs_probe;
sa.sa_flags = (SA_INTERRUPT);
sa.sa_mask = 0;
sa.sa_restorer = NULL;
for (i = 0, mask = 1; i < 16; i++, mask <<= 1) {
if (!(mask & dontgrab) && !irqaction(i, &sa)) {
irq_lines |= mask;
}
}
return irq_lines;
}
/*
* Release all interrupts grabbed by grab_all_interrupts
*/
static void free_all_interrupts(int irq_lines)
{
int i;
for (i = 0; i < 16; i++) {
if (irq_lines & (1 << i))
free_irq(i);
}
}
/*
* This routine figures out the correct timeout for a particular IRQ.
* It uses the smallest timeout of all of the serial ports in a
* particular interrupt chain.
*/
static void figure_IRQ_timeout(int irq)
{
struct async_struct *info;
int timeout = 6000; /* 60 seconds === a long time :-) */
info = IRQ_ports[irq];
if (!info) {
IRQ_timeout[irq] = 6000;
return;
}
while (info) {
if (info->timeout < timeout)
timeout = info->timeout;
info = info->next_port;
}
if (!irq)
timeout = timeout / 2;
IRQ_timeout[irq] = timeout ? timeout : 1;
}
static int startup(struct async_struct * info, int get_irq)
{
unsigned short ICP;
unsigned long flags;
struct sigaction sa;
int retval;
if (info->flags & ASYNC_INITIALIZED)
return 0;
if (!info->port || !info->type) {
if (info->tty)
set_bit(TTY_IO_ERROR, &info->tty->flags);
return 0;
}
save_flags(flags); cli();
#ifdef SERIAL_DEBUG_OPEN
printk("starting up ttys%d (irq %d)...", info->line, info->irq);
#endif
/*
* Allocate the IRQ if necessary
*/
if (get_irq && info->irq && !IRQ_ports[info->irq]) {
sa.sa_handler = rs_interrupt;
sa.sa_flags = (SA_INTERRUPT);
sa.sa_mask = 0;
sa.sa_restorer = NULL;
retval = irqaction(info->irq,&sa);
if (retval) {
restore_flags(flags);
return retval;
}
}
/*
* Clear the FIFO buffers and disable them
* (they will be reenabled in change_speed())
*/
if (info->type == PORT_16550A) {
serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT));
info->xmit_fifo_size = 16;
} else
info->xmit_fifo_size = 1;
/*
* Clear the interrupt registers.
*/
(void)serial_inp(info, UART_LSR);
(void)serial_inp(info, UART_RX);
(void)serial_inp(info, UART_IIR);
(void)serial_inp(info, UART_MSR);
/*
* Now, initialize the UART
*/
serial_outp(info, UART_LCR, UART_LCR_WLEN8); /* reset DLAB */
if (info->flags & ASYNC_FOURPORT)
serial_outp(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
else
serial_outp(info, UART_MCR,
UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
/*
* Finally, enable interrupts
*/
#ifdef ISR_HACK
info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
serial_outp(info, UART_IER, info->IER); /* enable interrupts */
#else
info->IER = (UART_IER_MSI | UART_IER_RLSI |
UART_IER_THRI | UART_IER_RDI);
serial_outp(info, UART_IER, info->IER); /* enable all intrs */
#endif
if (info->flags & ASYNC_FOURPORT) {
/* Enable interrupts on the AST Fourport board */
ICP = (info->port & 0xFE0) | 0x01F;
outb_p(0x80, ICP);
(void) inb_p(ICP);
}
/*
* And clear the interrupt registers again for luck.
*/
(void)serial_inp(info, UART_LSR);
(void)serial_inp(info, UART_RX);
(void)serial_inp(info, UART_IIR);
(void)serial_inp(info, UART_MSR);
if (info->tty)
clear_bit(TTY_IO_ERROR, &info->tty->flags);
/*
* Set up parity check flag
*/
if (info->tty && info->tty->termios && I_INPCK(info->tty))
info->read_status_mask = (UART_LSR_OE | UART_LSR_BI |
UART_LSR_FE | UART_LSR_PE);
else
info->read_status_mask = (UART_LSR_OE | UART_LSR_BI |
UART_LSR_FE);
/*
* Insert serial port into IRQ chain.
*/
info->prev_port = 0;
info->next_port = IRQ_ports[info->irq];
if (info->next_port)
info->next_port->prev_port = info;
IRQ_ports[info->irq] = info;
figure_IRQ_timeout(info->irq);
/*
* Set up serial timers...
*/
IRQ_active |= 1 << info->irq;
figure_RS_timer();
/*
* and set the speed of the serial port
*/
change_speed(info->line);
info->flags |= ASYNC_INITIALIZED;
restore_flags(flags);
return 0;
}
/*
* This routine will shutdown a serial port; interrupts are disabled, and
* DTR is dropped if the hangup on close termio flag is on.
*/
static void shutdown(struct async_struct * info, int do_free_irq)
{
unsigned long flags;
if (!(info->flags & ASYNC_INITIALIZED))
return;
#ifdef SERIAL_DEBUG_OPEN
printk("Shutting down serial port %d (irq %d)....", info->line,
info->irq);
#endif
save_flags(flags); cli(); /* Disable interrupts */
/*
* First unlink the serial port from the IRQ chain...
*/
if (info->next_port)
info->next_port->prev_port = info->prev_port;
if (info->prev_port)
info->prev_port->next_port = info->next_port;
else
IRQ_ports[info->irq] = info->next_port;
figure_IRQ_timeout(info->irq);
/*
* Free the IRQ, if necessary
*/
if (do_free_irq && info->irq && !IRQ_ports[info->irq])
free_irq(info->irq);
info->IER = 0;
serial_outp(info, UART_IER, 0x00); /* disable all intrs */
if (info->flags & ASYNC_FOURPORT) {
/* reset interrupts on the AST Fourport board */
(void) inb((info->port & 0xFE0) | 0x01F);
}
if (info->tty && !(info->tty->termios->c_cflag & HUPCL))
serial_outp(info, UART_MCR, UART_MCR_DTR);
else
/* reset DTR,RTS,OUT_2 */
serial_outp(info, UART_MCR, 0x00);
/* disable FIFO's */
serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT));
(void)serial_in(info, UART_RX); /* read data port to reset things */
if (info->tty)
set_bit(TTY_IO_ERROR, &info->tty->flags);
info->flags &= ~ASYNC_INITIALIZED;
restore_flags(flags);
}
/*
* This routine is called to set the UART divisor registers to match
* the specified baud rate for a serial port.
*/
static void change_speed(unsigned int line)
{
struct async_struct * info;
unsigned short port;
int quot = 0;
unsigned cflag,cval,mcr,fcr;
int i;
if (line >= NR_PORTS)
return;
info = rs_table + line;
if (!info->tty || !info->tty->termios)
return;
cflag = info->tty->termios->c_cflag;
if (!(port = info->port))
return;
i = cflag & CBAUD;
if (i == 15) {
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
i += 1;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
i += 2;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
quot = info->custom_divisor;
}
if (quot) {
info->timeout = ((info->xmit_fifo_size*HZ*15*quot) /
info->baud_base) + 2;
} else if (baud_table[i] == 134) {
quot = (2*info->baud_base / 269);
info->timeout = (info->xmit_fifo_size*HZ*30/269) + 2;
} else if (baud_table[i]) {
quot = info->baud_base / baud_table[i];
info->timeout = (info->xmit_fifo_size*HZ*15/baud_table[i]) + 2;
} else {
quot = 0;
info->timeout = 0;
}
cli();
mcr = serial_in(info, UART_MCR);
if (quot) {
serial_out(info, UART_MCR, mcr | UART_MCR_DTR);
} else {
serial_out(info, UART_MCR, mcr & ~UART_MCR_DTR);
sti();
return;
}
sti();
/* byte size and parity */
cval = cflag & (CSIZE | CSTOPB);
cval >>= 4;
if (cflag & PARENB)
cval |= UART_LCR_PARITY;
if (!(cflag & PARODD))
cval |= UART_LCR_EPAR;
if (info->type == PORT_16550A) {
if ((info->baud_base / quot) < 2400)
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
else
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_8;
} else
fcr = 0;
cli();
serial_outp(info, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
serial_outp(info, UART_DLL, quot & 0xff); /* LS of divisor */
serial_outp(info, UART_DLM, quot >> 8); /* MS of divisor */
serial_outp(info, UART_LCR, cval); /* reset DLAB */
serial_outp(info, UART_FCR, fcr); /* set fcr */
sti();
}
/*
* ------------------------------------------------------------
* rs_write() and friends
* ------------------------------------------------------------
*/
/*
* This routine is used by rs_write to restart transmitter interrupts,
* which are disabled after we have a transmitter interrupt which went
* unacknowledged because we had run out of data to transmit.
*
* Note: this subroutine must be called with the interrupts *off*
*/
static inline void restart_port(struct async_struct *info)
{
struct tty_queue * queue;
int head, tail, count;
if (!info)
return;
if (serial_inp(info, UART_LSR) & UART_LSR_THRE) {
if (info->x_char) {
serial_outp(info, UART_TX, info->x_char);
info->x_char = 0;
} else {
queue = &info->tty->write_q;
head = queue->head;
tail = queue->tail;
count = info->xmit_fifo_size;
while (count--) {
if (tail == head)
break;
serial_outp(info, UART_TX, queue->buf[tail++]);
tail &= TTY_BUF_SIZE-1;
}
queue->tail = tail;
}
}
}
/*
* This routine gets called when tty_write has put something into
* the write_queue.
*/
void rs_write(struct tty_struct * tty)
{
struct async_struct *info;
if (!tty || tty->stopped || tty->hw_stopped)
return;
info = rs_table + DEV_TO_SL(tty->line);
if (!info || !info->tty || !(info->flags & ASYNC_INITIALIZED))
return;
cli();
restart_port(info);
info->IER = (UART_IER_MSI | UART_IER_RLSI |
UART_IER_THRI | UART_IER_RDI);
#ifdef ISR_HACK
serial_out(info, UART_IER, info->IER);
#endif
sti();
}
/*
* ------------------------------------------------------------
* rs_throttle()
*
* This routine is called by the upper-layer tty layer to signal that
* incoming characters should be throttled (and that the throttle
* should be released).
* ------------------------------------------------------------
*/
static void rs_throttle(struct tty_struct * tty, int status)
{
struct async_struct *info;
unsigned char mcr;
unsigned long flags;
save_flags(flags); cli();
#if SERIAL_DEBUG_THROTTLE
printk("throttle tty%d: %d (%d, %d)....\n", DEV_TO_SL(tty->line),
status, LEFT(&tty->read_q), LEFT(&tty->secondary));
#endif
switch (status) {
case TTY_THROTTLE_RQ_FULL:
info = rs_table + DEV_TO_SL(tty->line);
if (I_IXOFF(tty)) {
info->x_char = STOP_CHAR(tty);
} else {
mcr = serial_inp(info, UART_MCR);
mcr &= ~UART_MCR_RTS;
serial_out(info, UART_MCR, mcr);
}
break;
case TTY_THROTTLE_RQ_AVAIL:
info = rs_table + DEV_TO_SL(tty->line);
if (I_IXOFF(tty)) {
if (info->x_char)
info->x_char = 0;
else
info->x_char = START_CHAR(tty);
} else {
mcr = serial_in(info, UART_MCR);
mcr |= UART_MCR_RTS;
serial_out(info, UART_MCR, mcr);
}
break;
}
restore_flags(flags);
}
/*
* ------------------------------------------------------------
* rs_ioctl() and friends
* ------------------------------------------------------------
*/
static int get_serial_info(struct async_struct * info,
struct serial_struct * retinfo)
{
struct serial_struct tmp;
if (!retinfo)
return -EFAULT;
memset(&tmp, 0, sizeof(tmp));
tmp.type = info->type;
tmp.line = info->line;
tmp.port = info->port;
tmp.irq = info->irq;
tmp.flags = info->flags;
tmp.baud_base = info->baud_base;
tmp.close_delay = info->close_delay;
tmp.custom_divisor = info->custom_divisor;
tmp.hub6 = info->hub6;
memcpy_tofs(retinfo,&tmp,sizeof(*retinfo));
return 0;
}
static int set_serial_info(struct async_struct * info,
struct serial_struct * new_info)
{
struct serial_struct new_serial;
struct async_struct old_info;
unsigned int i,change_irq,change_port;
int retval;
struct sigaction sa;
if (!new_info)
return -EFAULT;
memcpy_fromfs(&new_serial,new_info,sizeof(new_serial));
old_info = *info;
change_irq = new_serial.irq != info->irq;
change_port = (new_serial.port != info->port) || (new_serial.hub6 != info->hub6);
if (!suser()) {
if (change_irq || change_port ||
(new_serial.baud_base != info->baud_base) ||
(new_serial.type != info->type) ||
(new_serial.close_delay != info->close_delay) ||
((new_serial.flags & ~ASYNC_USR_MASK) !=
(info->flags & ~ASYNC_USR_MASK)))
return -EPERM;
info->flags = ((info->flags & ~ASYNC_USR_MASK) |
(new_serial.flags & ASYNC_USR_MASK));
info->custom_divisor = new_serial.custom_divisor;
goto check_and_exit;
}
if (new_serial.irq == 2)
new_serial.irq = 9;
if ((new_serial.irq > 15) || (new_serial.port > 0xffff) ||
(new_serial.type < PORT_UNKNOWN) || (new_serial.type > PORT_MAX)) {
return -EINVAL;
}
/* Make sure address is not already in use */
for (i = 0 ; i < NR_PORTS; i++)
if ((info != &rs_table[i]) &&
(rs_table[i].port == new_serial.port) && rs_table[i].type)
return -EADDRINUSE;
/*
* If necessary, first we try to grab the new IRQ for serial
* interrupts. (We have to do this early, since we may get an
* error trying to do this.)
*/
if (new_serial.port && new_serial.type && new_serial.irq &&
(change_irq || !(info->flags & ASYNC_INITIALIZED))) {
if (!IRQ_ports[new_serial.irq]) {
sa.sa_handler = rs_interrupt;
sa.sa_flags = (SA_INTERRUPT);
sa.sa_mask = 0;
sa.sa_restorer = NULL;
retval = irqaction(new_serial.irq,&sa);
if (retval)
return retval;
}
}
if ((change_port || change_irq) && (info->count > 1))
return -EBUSY;
/*
* OK, past this point, all the error checking has been done.
* At this point, we start making changes.....
*/
info->baud_base = new_serial.baud_base;
info->flags = ((info->flags & ~ASYNC_FLAGS) |
(new_serial.flags & ASYNC_FLAGS));
info->custom_divisor = new_serial.custom_divisor;
info->type = new_serial.type;
info->close_delay = new_serial.close_delay;
if (change_port || change_irq) {
/*
* We need to shutdown the serial port at the old
* port/irq combination.
*/
shutdown(info, change_irq);
info->irq = new_serial.irq;
info->port = new_serial.port;
info->hub6 = new_serial.hub6;
}
check_and_exit:
if (!info->port || !info->type)
return 0;
if (info->flags & ASYNC_INITIALIZED) {
if (((old_info.flags & ASYNC_SPD_MASK) !=
(info->flags & ASYNC_SPD_MASK)) ||
(old_info.custom_divisor != info->custom_divisor))
change_speed(info->line);
} else
(void) startup(info, 0);
return 0;
}
static int get_modem_info(struct async_struct * info, unsigned int *value)
{
unsigned char control, status;
unsigned int result;
cli();
control = serial_in(info, UART_MCR);
status = serial_in(info, UART_MSR);
sti();
result = ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
| ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
| ((status & UART_MSR_DCD) ? TIOCM_CAR : 0)
| ((status & UART_MSR_RI) ? TIOCM_RNG : 0)
| ((status & UART_MSR_DSR) ? TIOCM_DSR : 0)
| ((status & UART_MSR_CTS) ? TIOCM_CTS : 0);
put_fs_long(result,(unsigned long *) value);
return 0;
}
static int set_modem_info(struct async_struct * info, unsigned int cmd,
unsigned int *value)
{
unsigned char control;
unsigned int arg = get_fs_long((unsigned long *) value);
cli();
control = serial_in(info, UART_MCR);
sti();
switch (cmd) {
case TIOCMBIS:
if (arg & TIOCM_RTS)
control |= UART_MCR_RTS;
if (arg & TIOCM_DTR)
control |= UART_MCR_DTR;
break;
case TIOCMBIC:
if (arg & TIOCM_RTS)
control &= ~UART_MCR_RTS;
if (arg & TIOCM_DTR)
control &= ~UART_MCR_DTR;
break;
case TIOCMSET:
control = (control & ~(UART_MCR_RTS | UART_MCR_DTR))
| ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
| ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0);
break;
default:
return -EINVAL;
}
cli();
serial_out(info, UART_MCR, control);
sti();
return 0;
}
static int do_autoconfig(struct async_struct * info)
{
int retval;
if (!suser())
return -EPERM;
if (info->count > 1)
return -EBUSY;
shutdown(info, 1);
cli();
autoconfig(info);
sti();
retval = startup(info, 1);
if (retval)
return retval;
return 0;
}
/*
* This routine sends a break character out the serial port.
*/
static void send_break( struct async_struct * info, int duration)
{
if (!info->port)
return;
current->state = TASK_INTERRUPTIBLE;
current->timeout = jiffies + duration;
cli();
serial_out(info, UART_LCR, serial_inp(info, UART_LCR) | UART_LCR_SBC);
schedule();
serial_out(info, UART_LCR, serial_inp(info, UART_LCR) & ~UART_LCR_SBC);
sti();
}
/*
* This routine returns a bitfield of "wild interrupts". Basically,
* any unclaimed interrupts which is flapping around.
*/
static int check_wild_interrupts(int doprint)
{
int i, mask;
int wild_interrupts = 0;
int irq_lines;
unsigned long timeout;
unsigned long flags;
/* Turn on interrupts (they may be off) */
save_flags(flags); sti();
irq_lines = grab_all_interrupts(0);
/*
* Delay for 0.1 seconds -- we use a busy loop since this may
* occur during the bootup sequence
*/
timeout = jiffies+10;
while (timeout >= jiffies)
;
rs_triggered = 0; /* Reset after letting things settle */
timeout = jiffies+10;
while (timeout >= jiffies)
;
for (i = 0, mask = 1; i < 16; i++, mask <<= 1) {
if ((rs_triggered & (1 << i)) &&
(irq_lines & (1 << i))) {
wild_interrupts |= mask;
if (doprint)
printk("Wild interrupt? (IRQ %d)\n", i);
}
}
free_all_interrupts(irq_lines);
restore_flags(flags);
return wild_interrupts;
}
static int rs_ioctl(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg)
{
int error, line;
struct async_struct * info;
line = DEV_TO_SL(tty->line);
if (line < 0 || line >= NR_PORTS)
return -ENODEV;
info = rs_table + line;
switch (cmd) {
case TCSBRK: /* SVID version: non-zero arg --> no break */
if (!arg)
send_break(info, HZ/4); /* 1/4 second */
return 0;
case TCSBRKP: /* support for POSIX tcsendbreak() */
send_break(info, arg ? arg*(HZ/10) : HZ/4);
return 0;
case TIOCGSOFTCAR:
error = verify_area(VERIFY_WRITE, (void *) arg,sizeof(long));
if (error)
return error;
put_fs_long(C_CLOCAL(tty) ? 1 : 0,
(unsigned long *) arg);
return 0;
case TIOCSSOFTCAR:
arg = get_fs_long((unsigned long *) arg);
tty->termios->c_cflag =
((tty->termios->c_cflag & ~CLOCAL) |
(arg ? CLOCAL : 0));
return 0;
case TIOCMGET:
error = verify_area(VERIFY_WRITE, (void *) arg,
sizeof(unsigned int));
if (error)
return error;
return get_modem_info(info, (unsigned int *) arg);
case TIOCMBIS:
case TIOCMBIC:
case TIOCMSET:
return set_modem_info(info, cmd, (unsigned int *) arg);
case TIOCGSERIAL:
error = verify_area(VERIFY_WRITE, (void *) arg,
sizeof(struct serial_struct));
if (error)
return error;
return get_serial_info(info,
(struct serial_struct *) arg);
case TIOCSSERIAL:
return set_serial_info(info,
(struct serial_struct *) arg);
case TIOCSERCONFIG:
return do_autoconfig(info);
case TIOCSERGWILD:
error = verify_area(VERIFY_WRITE, (void *) arg,
sizeof(int));
if (error)
return error;
put_fs_long(rs_wild_int_mask, (unsigned long *) arg);
return 0;
case TIOCSERSWILD:
if (!suser())
return -EPERM;
rs_wild_int_mask = get_fs_long((unsigned long *) arg);
if (rs_wild_int_mask < 0)
rs_wild_int_mask = check_wild_interrupts(0);
return 0;
default:
return -EINVAL;
}
return 0;
}
static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
struct async_struct *info;
if (tty->termios->c_cflag == old_termios->c_cflag)
return;
info = &rs_table[DEV_TO_SL(tty->line)];
change_speed(DEV_TO_SL(tty->line));
if ((old_termios->c_cflag & CRTSCTS) &&
!(tty->termios->c_cflag & CRTSCTS)) {
tty->hw_stopped = 0;
rs_write(tty);
}
if (!(old_termios->c_cflag & CLOCAL) &&
(tty->termios->c_cflag & CLOCAL))
wake_up_interruptible(&info->open_wait);
if (I_INPCK(tty))
info->read_status_mask = (UART_LSR_OE | UART_LSR_BI |
UART_LSR_FE | UART_LSR_PE);
else
info->read_status_mask = (UART_LSR_OE | UART_LSR_BI |
UART_LSR_FE);
}
/*
* ------------------------------------------------------------
* rs_close()
*
* This routine is called when the serial port gets closed. First, we
* wait for the last remaining data to be sent. Then, we unlink its
* async structure from the interrupt chain if necessary, and we free
* that IRQ if nothing is left in the chain.
* ------------------------------------------------------------
*/
static void rs_close(struct tty_struct *tty, struct file * filp)
{
struct async_struct * info;
int line;
if (tty_hung_up_p(filp))
return;
line = DEV_TO_SL(tty->line);
if ((line < 0) || (line >= NR_PORTS))
return;
info = rs_table + line;
#ifdef SERIAL_DEBUG_OPEN
printk("rs_close ttys%d, count = %d\n", info->line, info->count);
#endif
if ((tty->count == 1) && (info->count != 1)) {
/*
* Uh, oh. tty->count is 1, which means that the tty
* structure will be freed. Info->count should always
* be one in these conditions. If it's greater than
* one, we've got real problems, since it means the
* serial port won't be shutdown.
*/
printk("rs_close: bad serial port count; tty->count is 1, "
"info->count is %d\n", info->count);
info->count = 1;
}
if (--info->count < 0) {
printk("rs_close: bad serial port count for ttys%d: %d\n",
info->line, info->count);
info->count = 0;
}
if (info->count)
return;
info->flags |= ASYNC_CLOSING;
/*
* Save the termios structure, since this port may have
* separate termios for callout and dialin.
*/
if (info->flags & ASYNC_NORMAL_ACTIVE)
info->normal_termios = *tty->termios;
if (info->flags & ASYNC_CALLOUT_ACTIVE)
info->callout_termios = *tty->termios;
tty->stopped = 0; /* Force flush to succeed */
tty->hw_stopped = 0;
if (info->flags & ASYNC_INITIALIZED) {
rs_start(tty);
/*
* XXX There should be a timeout added to
* wait_until_sent, eventually. TYT 1/19/94
*/
wait_until_sent(tty);
} else
flush_output(tty);
flush_input(tty);
cli();
/*
* Make sure the UART transmitter has completely drained; this
* is especially important if there is a transmit FIFO!
*/
if (!(serial_inp(info, UART_LSR) & UART_LSR_THRE)) {
rs_start(tty); /* Make sure THRI interrupt enabled */
interruptible_sleep_on(&info->xmit_wait);
}
sti();
shutdown(info, 1);
clear_bit(line, rs_event);
info->event = 0;
info->tty = 0;
if (info->blocked_open) {
if (info->close_delay) {
tty->count++; /* avoid race condition */
current->state = TASK_INTERRUPTIBLE;
current->timeout = jiffies + info->close_delay;
schedule();
tty->count--;
}
wake_up_interruptible(&info->open_wait);
}
info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE|
ASYNC_CLOSING);
wake_up_interruptible(&info->close_wait);
}
/*
* rs_hangup() --- called by tty_hangup() when a hangup is signaled.
*/
void rs_hangup(struct tty_struct *tty)
{
struct async_struct * info;
int line;
line = DEV_TO_SL(tty->line);
if ((line < 0) || (line >= NR_PORTS))
return;
info = rs_table + line;
shutdown(info, 1);
clear_bit(line, rs_event);
info->event = 0;
info->count = 0;
info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE);
info->tty = 0;
wake_up_interruptible(&info->open_wait);
}
/*
* ------------------------------------------------------------
* rs_open() and friends
* ------------------------------------------------------------
*/
static int block_til_ready(struct tty_struct *tty, struct file * filp,
struct async_struct *info)
{
struct wait_queue wait = { current, NULL };
int retval;
int do_clocal = C_CLOCAL(tty);
/*
* If the device is in the middle of being closed, then block
* until it's done, and then try again.
*/
if (info->flags & ASYNC_CLOSING) {
interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
if (info->flags & ASYNC_HUP_NOTIFY)
return -EAGAIN;
else
return -ERESTARTSYS;
#else
return -EAGAIN;
#endif
}
/*
* If this is a callout device, then just make sure the normal
* device isn't being used.
*/
if (MAJOR(filp->f_rdev) == TTYAUX_MAJOR) {
if (info->flags & ASYNC_NORMAL_ACTIVE)
return -EBUSY;
if ((info->flags & ASYNC_CALLOUT_ACTIVE) &&
(info->flags & ASYNC_SESSION_LOCKOUT) &&
(info->session != current->session))
return -EBUSY;
if ((info->flags & ASYNC_CALLOUT_ACTIVE) &&
(info->flags & ASYNC_PGRP_LOCKOUT) &&
(info->pgrp != current->pgrp))
return -EBUSY;
info->flags |= ASYNC_CALLOUT_ACTIVE;
return 0;
}
/*
* If non-blocking mode is set, then make the check up front
* and then exit.
*/
if (filp->f_flags & O_NONBLOCK) {
if (info->flags & ASYNC_CALLOUT_ACTIVE)
return -EBUSY;
info->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
/*
* Block waiting for the carrier detect and the line to become
* free (i.e., not in use by the callout). While we are in
* this loop, info->count is dropped by one, so that
* rs_close() knows when to free things. We restore it upon
* exit, either normal or abnormal.
*/
retval = 0;
add_wait_queue(&info->open_wait, &wait);
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready before block: ttys%d, count = %d\n",
info->line, info->count);
#endif
info->count--;
info->blocked_open++;
while (1) {
cli();
if (!(info->flags & ASYNC_CALLOUT_ACTIVE))
serial_out(info, UART_MCR,
serial_inp(info, UART_MCR) |
(UART_MCR_DTR | UART_MCR_RTS));
sti();
current->state = TASK_INTERRUPTIBLE;
if (tty_hung_up_p(filp) ||
!(info->flags & ASYNC_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
if (info->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
#else
retval = -EAGAIN;
#endif
break;
}
if (!(info->flags & ASYNC_CALLOUT_ACTIVE) &&
!(info->flags & ASYNC_CLOSING) &&
(do_clocal || (serial_in(info, UART_MSR) &
UART_MSR_DCD)))
break;
if (current->signal & ~current->blocked) {
retval = -ERESTARTSYS;
break;
}
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready blocking: ttys%d, count = %d\n",
info->line, info->count);
#endif
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&info->open_wait, &wait);
if (!tty_hung_up_p(filp))
info->count++;
info->blocked_open--;
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready after blocking: ttys%d, count = %d\n",
info->line, info->count);
#endif
if (retval)
return retval;
info->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
/*
* This routine is called whenever a serial port is opened. It
* enables interrupts for a serial port, linking in its async structure into
* the IRQ chain. It also performs the serial-speicific
* initalization for the tty structure.
*/
int rs_open(struct tty_struct *tty, struct file * filp)
{
struct async_struct *info;
int retval, line;
line = DEV_TO_SL(tty->line);
if ((line < 0) || (line >= NR_PORTS))
return -ENODEV;
info = rs_table + line;
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open ttys%d, count = %d\n", info->line, info->count);
#endif
info->count++;
info->tty = tty;
tty->write = rs_write;
tty->close = rs_close;
tty->ioctl = rs_ioctl;
tty->throttle = rs_throttle;
tty->set_termios = rs_set_termios;
tty->stop = rs_stop;
tty->start = rs_start;
tty->hangup = rs_hangup;
if ((info->count == 1) && (info->flags & ASYNC_SPLIT_TERMIOS)) {
if (MAJOR(filp->f_rdev) == TTY_MAJOR)
*tty->termios = info->normal_termios;
else
*tty->termios = info->callout_termios;
}
/*
* Start up serial port
*/
retval = startup(info, 1);
if (retval)
return retval;
retval = block_til_ready(tty, filp, info);
if (retval) {
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open returning after block_til_ready with %d\n",
retval);
#endif
return retval;
}
info->session = current->session;
info->pgrp = current->pgrp;
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open ttys%d successful...", info->line);
#endif
return 0;
}
/*
* ---------------------------------------------------------------------
* rs_init() and friends
*
* rs_init() is called at boot-time to initialize the serial driver.
* ---------------------------------------------------------------------
*/
/*
* This routine prints out the appropriate serial driver version
* number, and identifies which options were configured into this
* driver.
*/
static void show_serial_version(void)
{
printk("Serial driver version 3.99a with");
#ifdef CONFIG_AST_FOURPORT
printk(" AST_FOURPORT");
#define SERIAL_OPT
#endif
#ifdef CONFIG_ACCENT_ASYNC
printk(" ACCENT_ASYNC");
#define SERIAL_OPT
#endif
#ifdef CONFIG_HUB6
printk(" HUB-6");
#define SERIAL_OPT
#endif
#ifdef CONFIG_AUTO_IRQ
printk (" AUTO_IRQ");
#define SERIAL_OPT
#endif
#ifdef SERIAL_OPT
printk(" enabled\n");
#else
printk(" no serial options enabled\n");
#endif
#undef SERIAL_OPT
}
/*
* This routine is called by do_auto_irq(); it attempts to determine
* which interrupt a serial port is configured to use. It is not
* fool-proof, but it works a large part of the time.
*/
static int get_auto_irq(struct async_struct *info)
{
unsigned char save_MCR, save_IER, save_ICP=0;
unsigned short ICP=0, port = info->port;
unsigned long timeout;
/*
* Enable interrupts and see who answers
*/
rs_irq_triggered = 0;
cli();
save_IER = serial_inp(info, UART_IER);
save_MCR = serial_inp(info, UART_MCR);
if (info->flags & ASYNC_FOURPORT) {
serial_outp(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
serial_outp(info, UART_IER, 0x0f); /* enable all intrs */
ICP = (port & 0xFE0) | 0x01F;
save_ICP = inb_p(ICP);
outb_p(0x80, ICP);
(void) inb_p(ICP);
} else {
serial_outp(info, UART_MCR,
UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
serial_outp(info, UART_IER, 0x0f); /* enable all intrs */
}
sti();
/*
* Next, clear the interrupt registers.
*/
(void)serial_inp(info, UART_LSR);
(void)serial_inp(info, UART_RX);
(void)serial_inp(info, UART_IIR);
(void)serial_inp(info, UART_MSR);
timeout = jiffies+2;
while (timeout >= jiffies) {
if (rs_irq_triggered)
break;
}
/*
* Now check to see if we got any business, and clean up.
*/
cli();
serial_outp(info, UART_IER, save_IER);
serial_outp(info, UART_MCR, save_MCR);
if (info->flags & ASYNC_FOURPORT)
outb_p(save_ICP, ICP);
sti();
return(rs_irq_triggered);
}
/*
* Calls get_auto_irq() multiple times, to make sure we don't get
* faked out by random interrupts
*/
static int do_auto_irq(struct async_struct * info)
{
unsigned port = info->port;
int irq_lines = 0;
int irq_try_1 = 0, irq_try_2 = 0;
int retries;
unsigned long flags;
if (!port)
return 0;
/* Turn on interrupts (they may be off) */
save_flags(flags); sti();
irq_lines = grab_all_interrupts(rs_wild_int_mask);
for (retries = 0; retries < 5; retries++) {
if (!irq_try_1)
irq_try_1 = get_auto_irq(info);
if (!irq_try_2)
irq_try_2 = get_auto_irq(info);
if (irq_try_1 && irq_try_2) {
if (irq_try_1 == irq_try_2)
break;
irq_try_1 = irq_try_2 = 0;
}
}
restore_flags(flags);
free_all_interrupts(irq_lines);
return (irq_try_1 == irq_try_2) ? irq_try_1 : 0;
}
/*
* This routine is called by rs_init() to initialize a specific serial
* port. It determines what type of UART ship 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 async_struct * info)
{
unsigned char status1, status2, scratch, scratch2;
unsigned port = info->port;
unsigned long flags;
info->type = PORT_UNKNOWN;
if (!port)
return;
save_flags(flags); cli();
/*
* Do a simple existence test first; if we fail this, there's
* no point trying anything else.
*/
scratch = serial_inp(info, UART_IER);
serial_outp(info, UART_IER, 0);
scratch2 = serial_inp(info, UART_IER);
serial_outp(info, UART_IER, scratch);
if (scratch2) {
restore_flags(flags);
return; /* We failed; there's nothing here */
}
/*
* 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
* manufactucturer would be stupid enough to design a board
* that conflicts with COM 1-4 --- we hope!
*/
if (!(info->flags & ASYNC_SKIP_TEST)) {
scratch = serial_inp(info, UART_MCR);
serial_outp(info, UART_MCR, UART_MCR_LOOP | scratch);
scratch2 = serial_inp(info, UART_MSR);
serial_outp(info, UART_MCR, UART_MCR_LOOP | 0x0A);
status1 = serial_inp(info, UART_MSR) & 0xF0;
serial_outp(info, UART_MCR, scratch);
serial_outp(info, UART_MSR, scratch2);
if (status1 != 0x90) {
restore_flags(flags);
return;
}
}
/*
* If the AUTO_IRQ flag is set, try to do the automatic IRQ
* detection.
*/
if (info->flags & ASYNC_AUTO_IRQ)
info->irq = do_auto_irq(info);
serial_outp(info, UART_FCR, UART_FCR_ENABLE_FIFO);
scratch = serial_in(info, UART_IIR) >> 6;
info->xmit_fifo_size = 1;
switch (scratch) {
case 0:
info->type = PORT_16450;
break;
case 1:
info->type = PORT_UNKNOWN;
break;
case 2:
info->type = PORT_16550;
break;
case 3:
info->type = PORT_16550A;
info->xmit_fifo_size = 16;
break;
}
if (info->type == PORT_16450) {
scratch = serial_in(info, UART_SCR);
serial_outp(info, UART_SCR, 0xa5);
status1 = serial_in(info, UART_SCR);
serial_outp(info, UART_SCR, 0x5a);
status2 = serial_in(info, UART_SCR);
serial_outp(info, UART_SCR, scratch);
if ((status1 != 0xa5) || (status2 != 0x5a))
info->type = PORT_8250;
}
/*
* Reset the UART.
*/
serial_outp(info, UART_MCR, 0x00);
serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT));
(void)serial_in(info, UART_RX);
restore_flags(flags);
}
/*
* The serial driver boot-time initialization code!
*/
long rs_init(long kmem_start)
{
int i;
struct async_struct * info;
memset(&rs_event, 0, sizeof(rs_event));
bh_base[SERIAL_BH].routine = do_softint;
timer_table[RS_TIMER].fn = rs_timer;
timer_table[RS_TIMER].expires = 0;
IRQ_active = 0;
#ifdef CONFIG_AUTO_IRQ
rs_wild_int_mask = check_wild_interrupts(1);
#endif
for (i = 0; i < 16; i++) {
IRQ_ports[i] = 0;
IRQ_timeout[i] = 0;
}
show_serial_version();
for (i = 0, info = rs_table; i < NR_PORTS; i++,info++) {
info->line = i;
info->tty = 0;
info->type = PORT_UNKNOWN;
info->custom_divisor = 0;
info->close_delay = 50;
info->x_char = 0;
info->event = 0;
info->count = 0;
info->blocked_open = 0;
memset(&info->callout_termios, 0, sizeof(struct termios));
memset(&info->normal_termios, 0, sizeof(struct termios));
info->open_wait = 0;
info->xmit_wait = 0;
info->close_wait = 0;
info->next_port = 0;
info->prev_port = 0;
if (info->irq == 2)
info->irq = 9;
if (!(info->flags & ASYNC_BOOT_AUTOCONF))
continue;
autoconfig(info);
if (info->type == PORT_UNKNOWN)
continue;
printk("tty%02d%s at 0x%04x (irq = %d)", info->line,
(info->flags & ASYNC_FOURPORT) ? " FourPort" : "",
info->port, info->irq);
switch (info->type) {
case PORT_8250:
printk(" is a 8250\n");
break;
case PORT_16450:
printk(" is a 16450\n");
break;
case PORT_16550:
printk(" is a 16550\n");
break;
case PORT_16550A:
printk(" is a 16550A\n");
break;
default:
printk("\n");
break;
}
}
return kmem_start;
}
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