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[/] [or1k_old/] [trunk/] [rc203soc/] [sw/] [uClinux/] [arch/] [armnommu/] [drivers/] [char/] [serial.c] - Blame information for rev 1765

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/*
 *  linux/arch/arm/drivers/char/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.
 *
 *  11/95: TIOCMIWAIT, TIOCGICOUNT by Angelo Haritsis <ah@doc.ic.ac.uk>
 *
 *  03/96: Modularised by Angelo Haritsis <ah@doc.ic.ac.uk>
 *
 *  rs_set_termios fixed to look also for changes of the input
 *      flags INPCK, BRKINT, PARMRK, IGNPAR and IGNBRK.
 *                                              Bernd Anh�upl 05/17/96.
 *
 * This module exports the following rs232 io functions:
 *
 *      int rs_init(void);
 *      int rs_open(struct tty_struct * tty, struct file * filp)
 *
 *  Slight modifications for ARM Copyright (C) 1995, 1996 Russell King
 */
 
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
#include <linux/config.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
 
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/segment.h>
#include <asm/bitops.h>
#include <asm/serial.h>
 
static char *serial_name = "Serial driver";
static char *serial_version = "4.13";
 
DECLARE_TASK_QUEUE(tq_serial);
 
struct tty_driver serial_driver, callout_driver;
static int serial_refcount;
 
/* serial subtype definitions */
#define SERIAL_TYPE_NORMAL      1
#define SERIAL_TYPE_CALLOUT     2
 
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
 
/*
 * Serial driver configuration section.  Here are the various options:
 *
 * CONFIG_HUB6
 *              Enables support for the venerable Bell Technologies
 *              HUB6 card.
 *
 * SERIAL_PARANOIA_CHECK
 *              Check the magic number for the async_structure where
 *              ever possible.
 */
 
#define SERIAL_PARANOIA_CHECK
#define CONFIG_SERIAL_NOPAUSE_IO
#define SERIAL_DO_RESTART
 
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
 
#define RS_STROBE_TIME (10*HZ)
#define RS_ISR_PASS_LIMIT 256
 
#define IRQ_T(info) ((info->flags & ASYNC_SHARE_IRQ) ? SA_SHIRQ : SA_INTERRUPT)
 
#define _INLINE_ inline
 
#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
 kdevname(tty->device), (info->flags), serial_refcount,info->count,tty->count,s)
#else
#define DBG_CNT(s)
#endif
 
/*
 * IRQ_timeout          - How long the timeout should be for each IRQ
 *                              should be after the IRQ has been active.
 */
 
static struct async_struct *IRQ_ports[NR_IRQS];
static struct rs_multiport_struct rs_multiport[NR_IRQS];
static int IRQ_timeout[NR_IRQS];
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(struct async_struct *info);
 
struct async_struct rs_table[] = {
        RS_UARTS
};
 
#define NR_PORTS        (sizeof(rs_table)/sizeof(struct async_struct))
 
static struct tty_struct *serial_table[NR_PORTS];
static struct termios *serial_termios[NR_PORTS];
static struct termios *serial_termios_locked[NR_PORTS];
 
#ifndef MIN
#define MIN(a,b)        ((a) < (b) ? (a) : (b))
#endif
 
/*
 * tmp_buf is used as a temporary buffer by serial_write.  We need to
 * lock it in case the memcpy_fromfs blocks while swapping in a page,
 * and some other program tries to do a serial write at the same time.
 * Since the lock will only come under contention when the system is
 * swapping and available memory is low, it makes sense to share one
 * buffer across all the serial ports, since it significantly saves
 * memory if large numbers of serial ports are open.
 */
static unsigned char *tmp_buf;
static struct semaphore tmp_buf_sem = MUTEX;
 
static inline int serial_paranoia_check(struct async_struct *info,
                                        kdev_t device, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
        static const char *badmagic =
                "Warning: bad magic number for serial struct (%s) in %s\n";
        static const char *badinfo =
                "Warning: null async_struct for (%s) in %s\n";
 
        if (!info) {
                printk(badinfo, kdevname(device), routine);
                return 1;
        }
        if (info->magic != SERIAL_MAGIC) {
                printk(badmagic, kdevname(device), routine);
                return 1;
        }
#endif
        return 0;
}
 
/*
 * This is used to figure out the divisor 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 inline unsigned int serial_in(struct async_struct *info, int offset)
{
#ifdef CONFIG_HUB6
    if (info->hub6) {
        outb(info->hub6 - 1 + offset, info->port);
        return inb(info->port+1);
    } else
#endif
        return inb(info->port + offset);
}
 
static inline unsigned int serial_inp(struct async_struct *info, int offset)
{
#ifdef CONFIG_HUB6
    if (info->hub6) {
        outb(info->hub6 - 1 + offset, info->port);
        return inb_p(info->port+1);
    } else
#endif
#ifdef CONFIG_SERIAL_NOPAUSE_IO
        return inb(info->port + offset);
#else
        return inb_p(info->port + offset);
#endif
}
 
static inline void serial_out(struct async_struct *info, int offset, int value)
{
#ifdef CONFIG_HUB6
    if (info->hub6) {
        outb(info->hub6 - 1 + offset, info->port);
        outb(value, info->port+1);
    } else
#endif
        outb(value, info->port+offset);
}
 
static inline void serial_outp(struct async_struct *info, int offset,
                               int value)
{
#ifdef CONFIG_HUB6
    if (info->hub6) {
        outb(info->hub6 - 1 + offset, info->port);
        outb_p(value, info->port+1);
    } else
#endif
#ifdef CONFIG_SERIAL_NOPAUSE_IO
        outb(value, info->port+offset);
#else
        outb_p(value, info->port+offset);
#endif
}
 
/*
 * ------------------------------------------------------------
 * 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 = (struct async_struct *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_stop"))
                return;
 
        save_flags_cli (flags);
        if (info->IER & UART_IER_THRI) {
                info->IER &= ~UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
        restore_flags(flags);
}
 
static void rs_start(struct tty_struct *tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_start"))
                return;
 
        save_flags_cli (flags);
        if (info->xmit_cnt && info->xmit_buf && !(info->IER & UART_IER_THRI)) {
                info->IER |= UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
        restore_flags(flags);
}
 
/*
 * ----------------------------------------------------------------------
 *
 * 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, void *dev_id, struct pt_regs * regs)
{
        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;
        queue_task_irq_off(&info->tqueue, &tq_serial);
        mark_bh(SERIAL_BH);
}
 
static _INLINE_ void receive_chars(struct async_struct *info,
                                 int *status)
{
        struct tty_struct *tty = info->tty;
        unsigned char ch;
        int ignored = 0;
 
        do {
                ch = serial_inp(info, UART_RX);
                if (*status & info->ignore_status_mask) {
                        if (++ignored > 100)
                                break;
                        goto ignore_char;
                }
                if (tty->flip.count >= TTY_FLIPBUF_SIZE)
                        break;
                tty->flip.count++;
                if (*status & (UART_LSR_BI)) {
#ifdef SERIAL_DEBUG_INTR
                        printk("handling break....");
#endif
                        *tty->flip.flag_buf_ptr++ = TTY_BREAK;
                        if (info->flags & ASYNC_SAK)
                                do_SAK(tty);
                } else if (*status & UART_LSR_PE)
                        *tty->flip.flag_buf_ptr++ = TTY_PARITY;
                else if (*status & UART_LSR_FE)
                        *tty->flip.flag_buf_ptr++ = TTY_FRAME;
                else if (*status & UART_LSR_OE)
                        *tty->flip.flag_buf_ptr++ = TTY_OVERRUN;
                else
                        *tty->flip.flag_buf_ptr++ = 0;
                *tty->flip.char_buf_ptr++ = ch;
        ignore_char:
                *status = serial_inp(info, UART_LSR) & info->read_status_mask;
        } while (*status & UART_LSR_DR);
        queue_task_irq_off(&tty->flip.tqueue, &tq_timer);
#ifdef SERIAL_DEBUG_INTR
        printk("DR...");
#endif
}
 
static _INLINE_ void transmit_chars(struct async_struct *info, int *intr_done)
{
        int count;
 
        if (info->x_char) {
                serial_outp(info, UART_TX, info->x_char);
                info->x_char = 0;
                if (intr_done)
                        *intr_done = 0;
                return;
        }
        if ((info->xmit_cnt <= 0) || info->tty->stopped ||
            info->tty->hw_stopped) {
                info->IER &= ~UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
                return;
        }
 
        count = info->xmit_fifo_size;
        do {
                serial_out(info, UART_TX, info->xmit_buf[info->xmit_tail++]);
                info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
                if (--info->xmit_cnt <= 0)
                        break;
        } while (--count > 0);
 
        if (info->xmit_cnt < WAKEUP_CHARS)
                rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
 
#ifdef SERIAL_DEBUG_INTR
        printk("THRE...");
#endif
        if (intr_done)
                *intr_done = 0;
 
        if (info->xmit_cnt <= 0) {
                info->IER &= ~UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
}
 
static _INLINE_ void check_modem_status(struct async_struct *info)
{
        int     status;
 
        status = serial_in(info, UART_MSR);
 
        if (status & UART_MSR_ANY_DELTA) {
                /* update input line counters */
                if (status & UART_MSR_TERI)
                        info->icount.rng++;
                if (status & UART_MSR_DDSR)
                        info->icount.dsr++;
                if (status & UART_MSR_DDCD)
                        info->icount.dcd++;
                if (status & UART_MSR_DCTS)
                        info->icount.cts++;
                wake_up_interruptible(&info->delta_msr_wait);
        }
 
        if ((info->flags & ASYNC_CHECK_CD) && (status & UART_MSR_DDCD)) {
#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)
                        wake_up_interruptible(&info->open_wait);
                else if (!((info->flags & ASYNC_CALLOUT_ACTIVE) &&
                           (info->flags & ASYNC_CALLOUT_NOHUP))) {
#ifdef SERIAL_DEBUG_OPEN
                        printk("scheduling hangup...");
#endif
                        queue_task_irq_off(&info->tqueue_hangup,
                                           &tq_scheduler);
                }
        }
        if (info->flags & ASYNC_CTS_FLOW) {
                if (info->tty->hw_stopped) {
                        if (status & UART_MSR_CTS) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
                                printk("CTS tx start...");
#endif
                                info->tty->hw_stopped = 0;
                                info->IER |= UART_IER_THRI;
                                serial_out(info, UART_IER, info->IER);
                                rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
                                return;
                        }
                } else {
                        if (!(status & UART_MSR_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
                                printk("CTS tx stop...");
#endif
                                info->tty->hw_stopped = 1;
                                info->IER &= ~UART_IER_THRI;
                                serial_out(info, UART_IER, info->IER);
                        }
                }
        }
}
 
/*
 * This is the serial driver's generic interrupt routine
 */
static void rs_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
        int status;
        struct async_struct * info;
        int pass_counter = 0;
        struct async_struct *end_mark = 0;
        int first_multi = 0;
        struct rs_multiport_struct *multi;
 
#ifdef SERIAL_DEBUG_INTR
        printk("rs_interrupt(%d)...", irq);
#endif
 
        info = IRQ_ports[irq];
        if (!info)
                return;
 
        multi = &rs_multiport[irq];
        if (multi->port_monitor)
                first_multi = inb(multi->port_monitor);
 
        do {
                if (!info->tty ||
                    (serial_in(info, UART_IIR) & UART_IIR_NO_INT)) {
                        if (!end_mark)
                                end_mark = info;
                        goto next;
                }
                end_mark = 0;
 
                info->last_active = jiffies;
 
                status = serial_inp(info, UART_LSR) & info->read_status_mask;
#ifdef SERIAL_DEBUG_INTR
                printk("status = %x...", status);
#endif
                if (status & UART_LSR_DR)
                        receive_chars(info, &status);
                check_modem_status(info);
                if (status & UART_LSR_THRE)
                        transmit_chars(info, 0);
 
        next:
                info = info->next_port;
                if (!info) {
                        info = IRQ_ports[irq];
                        if (pass_counter++ > RS_ISR_PASS_LIMIT) {
#if 0
                                printk("rs loop break\n");
#endif
                                break;  /* Prevent infinite loops */
                        }
                        continue;
                }
        } while (end_mark != info);
        if (multi->port_monitor)
                printk("rs port monitor (normal) irq %d: 0x%x, 0x%x\n",
                       info->irq, first_multi, inb(multi->port_monitor));
#ifdef SERIAL_DEBUG_INTR
        printk("end.\n");
#endif
}
 
/*
 * This is the serial driver's interrupt routine for a single port
 */
static void rs_interrupt_single(int irq, void *dev_id, struct pt_regs * regs)
{
        int status;
        int pass_counter = 0;
        int first_multi = 0;
        struct async_struct * info;
        struct rs_multiport_struct *multi;
 
#ifdef SERIAL_DEBUG_INTR
        printk("rs_interrupt_single(%d)...", irq);
#endif
 
        info = IRQ_ports[irq];
        if (!info || !info->tty)
                return;
 
        multi = &rs_multiport[irq];
        if (multi->port_monitor)
                first_multi = inb(multi->port_monitor);
 
        do {
                status = serial_inp(info, UART_LSR) & info->read_status_mask;
#ifdef SERIAL_DEBUG_INTR
                printk("status = %x...", status);
#endif
                if (status & UART_LSR_DR)
                        receive_chars(info, &status);
                check_modem_status(info);
                if (status & UART_LSR_THRE)
                        transmit_chars(info, 0);
                if (pass_counter++ > RS_ISR_PASS_LIMIT) {
#if 0
                        printk("rs_single loop break.\n");
#endif
                        break;
                }
        } while (!(serial_in(info, UART_IIR) & UART_IIR_NO_INT));
        info->last_active = jiffies;
        if (multi->port_monitor)
                printk("rs port monitor (single) irq %d: 0x%x, 0x%x\n",
                       info->irq, first_multi, inb(multi->port_monitor));
#ifdef SERIAL_DEBUG_INTR
        printk("end.\n");
#endif
}
 
/*
 * This is the serial driver's for multiport boards
 */
static void rs_interrupt_multi(int irq, void *dev_id, struct pt_regs * regs)
{
        int status;
        struct async_struct * info;
        int pass_counter = 0;
        int first_multi= 0;
        struct rs_multiport_struct *multi;
 
#ifdef SERIAL_DEBUG_INTR
        printk("rs_interrupt_multi(%d)...", irq);
#endif
 
        info = IRQ_ports[irq];
        if (!info)
                return;
        multi = &rs_multiport[irq];
        if (!multi->port1) {
                /* Should never happen */
                printk("rs_interrupt_multi: NULL port1!\n");
                return;
        }
        if (multi->port_monitor)
                first_multi = inb(multi->port_monitor);
 
        while (1) {
                if (!info->tty ||
                    (serial_in(info, UART_IIR) & UART_IIR_NO_INT))
                        goto next;
 
                info->last_active = jiffies;
 
                status = serial_inp(info, UART_LSR) & info->read_status_mask;
#ifdef SERIAL_DEBUG_INTR
                printk("status = %x...", status);
#endif
                if (status & UART_LSR_DR)
                        receive_chars(info, &status);
                check_modem_status(info);
                if (status & UART_LSR_THRE)
                        transmit_chars(info, 0);
 
        next:
                info = info->next_port;
                if (info)
                        continue;
 
                info = IRQ_ports[irq];
                if (pass_counter++ > RS_ISR_PASS_LIMIT) {
#if 1
                        printk("rs_multi loop break\n");
#endif
                        break;  /* Prevent infinite loops */
                }
                if (multi->port_monitor)
                        printk("rs port monitor irq %d: 0x%x, 0x%x\n",
                               info->irq, first_multi,
                               inb(multi->port_monitor));
                if ((inb(multi->port1) & multi->mask1) != multi->match1)
                        continue;
                if (!multi->port2)
                        break;
                if ((inb(multi->port2) & multi->mask2) != multi->match2)
                        continue;
                if (!multi->port3)
                        break;
                if ((inb(multi->port3) & multi->mask3) != multi->match3)
                        continue;
                if (!multi->port4)
                        break;
                if ((inb(multi->port4) & multi->mask4) == multi->match4)
                        continue;
                break;
        }
#ifdef SERIAL_DEBUG_INTR
        printk("end.\n");
#endif
}
 
 
/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */
 
/*
 * 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_serial_bh(void)
{
        run_task_queue(&tq_serial);
}
 
static void do_softint(void *private_)
{
        struct async_struct     *info = (struct async_struct *) private_;
        struct tty_struct       *tty;
 
        tty = info->tty;
        if (!tty)
                return;
 
        if (clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
                if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
                    tty->ldisc.write_wakeup)
                        (tty->ldisc.write_wakeup)(tty);
                wake_up_interruptible(&tty->write_wait);
        }
}
 
/*
 * This routine is called from the scheduler tqueue when the interrupt
 * routine has signalled that a hangup has occurred.  The path of
 * hangup processing is:
 *
 *      serial interrupt routine -> (scheduler tqueue) ->
 *      do_serial_hangup() -> tty->hangup() -> rs_hangup()
 *
 */
static void do_serial_hangup(void *private_)
{
        struct async_struct     *info = (struct async_struct *) private_;
        struct tty_struct       *tty;
 
        tty = info->tty;
        if (!tty)
                return;
 
        tty_hangup(tty);
}
 
 
/*
 * This subroutine is called when the RS_TIMER goes off.  It is used
 * by the serial driver to handle ports that do not have an interrupt
 * (irq=0).  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 rs_timer(void)
{
        static unsigned long last_strobe = 0;
        struct async_struct *info;
        unsigned int    i;
 
        if ((jiffies - last_strobe) >= RS_STROBE_TIME) {
                for (i=0; i < 32; i++) {
                        info = IRQ_ports[i];
                        if (!info)
                                continue;
                        cli();
                        if (info->next_port) {
                                do {
                                        serial_out(info, UART_IER, 0);
                                        info->IER |= UART_IER_THRI;
                                        serial_out(info, UART_IER, info->IER);
                                        info = info->next_port;
                                } while (info);
                                if (rs_multiport[i].port1)
                                        rs_interrupt_multi(i, NULL, NULL);
                                else
                                        rs_interrupt(i, NULL, NULL);
                        } else
                                rs_interrupt_single(i, NULL, NULL);
                        sti();
                }
        }
        last_strobe = jiffies;
        timer_table[RS_TIMER].expires = jiffies + RS_STROBE_TIME;
        timer_active |= 1 << RS_TIMER;
 
        if (IRQ_ports[0]) {
                cli();
                rs_interrupt(0, NULL, NULL);
                sti();
 
                timer_table[RS_TIMER].expires = jiffies + IRQ_timeout[0] - 2;
        }
}
 
/*
 * ---------------------------------------------------------------
 * 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;
 
        for (i = 0, mask = 1; i < 16; i++, mask <<= 1) {
                if (!(mask & dontgrab) && !request_irq(i, rs_probe, SA_INTERRUPT, "serial probe", NULL)) {
                        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, NULL);
        }
}
 
/*
 * 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.  Now only used for IRQ 0....
 */
static void figure_IRQ_timeout(int irq)
{
        struct  async_struct    *info;
        int     timeout = 60*HZ;        /* 60 seconds === a long time :-) */
 
        info = IRQ_ports[irq];
        if (!info) {
                IRQ_timeout[irq] = 60*HZ;
                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)
{
        unsigned short ICP;
        unsigned long flags;
        int     retval;
        void (*handler)(int, void *, struct pt_regs *);
        unsigned long page;
 
        page = get_free_page(GFP_KERNEL);
        if (!page)
                return -ENOMEM;
 
 
        save_flags_cli(flags);
 
        if (info->flags & ASYNC_INITIALIZED) {
                free_page(page);
                restore_flags(flags);
                return 0;
        }
 
        if (!info->port || !info->type) {
                if (info->tty)
                        set_bit(TTY_IO_ERROR, &info->tty->flags);
                free_page(page);
                restore_flags(flags);
                return 0;
        }
        if (info->xmit_buf)
                free_page(page);
        else
                info->xmit_buf = (unsigned char *) page;
 
#ifdef SERIAL_DEBUG_OPEN
        printk("starting up ttys%d (irq %d)...", info->line, info->irq);
#endif
 
        /*
         * Clear the FIFO buffers and disable them
         * (they will be reenabled in change_speed())
         */
        if (info->type == PORT_16650) {
                serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR |
                                             UART_FCR_CLEAR_XMIT));
                info->xmit_fifo_size = 1; /* disabled for now */
        } else 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;
 
        /*
         * 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 (serial_inp(info, UART_LSR) == 0xff) {
                restore_flags(flags);
                if (suser()) {
                        if (info->tty)
                                set_bit(TTY_IO_ERROR, &info->tty->flags);
                        return 0;
                } else
                        return -ENODEV;
        }
 
        /*
         * Allocate the IRQ if necessary
         */
        if (info->irq && (!IRQ_ports[info->irq] ||
                          !IRQ_ports[info->irq]->next_port)) {
                if (IRQ_ports[info->irq]) {
                        free_irq(info->irq, NULL);
                        if (rs_multiport[info->irq].port1)
                                handler = rs_interrupt_multi;
                        else
                                handler = rs_interrupt;
                } else
                        handler = rs_interrupt_single;
 
                retval = request_irq(info->irq, handler, IRQ_T(info),
                                     "serial", NULL);
                if (retval) {
                        restore_flags(flags);
                        if (suser()) {
                                if (info->tty)
                                        set_bit(TTY_IO_ERROR,
                                                &info->tty->flags);
                                return 0;
                        } else
                                return retval;
                }
        }
 
        /*
         * Clear the interrupt registers.
         */
     /* (void) serial_inp(info, UART_LSR); */   /* (see above) */
        (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) {
                info->MCR = UART_MCR_DTR | UART_MCR_RTS;
                info->MCR_noint = UART_MCR_DTR | UART_MCR_OUT1;
        } else {
                info->MCR = UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2;
                info->MCR_noint = UART_MCR_DTR | UART_MCR_RTS;
        }
#if defined(__alpha__) && !defined(CONFIG_PCI)
        info->MCR |= UART_MCR_OUT1 | UART_MCR_OUT2;
        info->MCR_noint |= UART_MCR_OUT1 | UART_MCR_OUT2;
#endif
        if (info->irq == 0)
                info->MCR = info->MCR_noint;
        serial_outp(info, UART_MCR, info->MCR);
 
        /*
         * Finally, enable interrupts
         */
        info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
        serial_outp(info, UART_IER, info->IER); /* enable interrupts */
 
        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);
        info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 
        /*
         * 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...
         */
        timer_table[RS_TIMER].expires = jiffies + 2*HZ/100;
        timer_active |= 1 << RS_TIMER;
 
        /*
         * and set the speed of the serial port
         */
        change_speed(info);
 
        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)
{
        unsigned long   flags;
        int             retval;
 
        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_cli(flags); /* Disable interrupts */
 
        /*
         * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
         * here so the queue might never be waken up
         */
        wake_up_interruptible(&info->delta_msr_wait);
 
        /*
         * 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 (info->irq && (!IRQ_ports[info->irq] ||
                          !IRQ_ports[info->irq]->next_port)) {
                if (IRQ_ports[info->irq]) {
                        free_irq(info->irq, NULL);
                        retval = request_irq(info->irq, rs_interrupt_single,
                                             IRQ_T(info), "serial", NULL);
 
                        if (retval)
                                printk("serial shutdown: request_irq: error %d"
                                       "  Couldn't reacquire IRQ.\n", retval);
                } else
                        free_irq(info->irq, NULL);
        }
 
        if (info->xmit_buf) {
                free_page((unsigned long) info->xmit_buf);
                info->xmit_buf = 0;
        }
 
        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)) {
                info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
                info->MCR_noint &= ~(UART_MCR_DTR|UART_MCR_RTS);
        }
        serial_outp(info, UART_MCR, info->MCR_noint);
 
        /* 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(struct async_struct *info)
{
        unsigned short port;
        int     quot = 0;
        unsigned cflag,cval,fcr;
        int     i;
 
        if (!info->tty || !info->tty->termios)
                return;
        cflag = info->tty->termios->c_cflag;
        if (!(port = info->port))
                return;
        i = cflag & CBAUD;
        if (i & CBAUDEX) {
                i &= ~CBAUDEX;
                if (i < 1 || i > 2)
                        info->tty->termios->c_cflag &= ~CBAUDEX;
                else
                        i += 15;
        }
        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;
        }
        if (quot) {
                info->MCR |= UART_MCR_DTR;
                info->MCR_noint |= UART_MCR_DTR;
                cli();
                serial_out(info, UART_MCR, info->MCR);
                sti();
        } else {
                info->MCR &= ~UART_MCR_DTR;
                info->MCR_noint &= ~UART_MCR_DTR;
                cli();
                serial_out(info, UART_MCR, info->MCR);
                sti();
                return;
        }
        /* byte size and parity */
        switch (cflag & CSIZE) {
              case CS5: cval = 0x00; break;
              case CS6: cval = 0x01; break;
              case CS7: cval = 0x02; break;
              case CS8: cval = 0x03; break;
              default:  cval = 0x00; break;     /* too keep GCC shut... */
        }
        if (cflag & CSTOPB) {
                cval |= 0x04;
        }
        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 if (info->type == PORT_16650) {
                /*
                 * On the 16650, we disable the FIFOs altogether
                 * because of a design bug in how the implement
                 * things.  We could support it by completely changing
                 * how we handle the interrupt driver, but not today....
                 *
                 * N.B.  Because there's no way to set a FIFO trigger
                 * at 1 char, we'd probably disable at speed below
                 * 2400 baud anyway...
                 */
                fcr = 0;
        } else
                fcr = 0;
 
        /* CTS flow control flag and modem status interrupts */
        info->IER &= ~UART_IER_MSI;
        if (cflag & CRTSCTS) {
                info->flags |= ASYNC_CTS_FLOW;
                info->IER |= UART_IER_MSI;
        } else
                info->flags &= ~ASYNC_CTS_FLOW;
        if (cflag & CLOCAL)
                info->flags &= ~ASYNC_CHECK_CD;
        else {
                info->flags |= ASYNC_CHECK_CD;
                info->IER |= UART_IER_MSI;
        }
        serial_out(info, UART_IER, info->IER);
 
        /*
         * Set up parity check flag
         */
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
 
        info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
        if (I_INPCK(info->tty))
                info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
        if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
                info->read_status_mask |= UART_LSR_BI;
 
        info->ignore_status_mask = 0;
#if 0
        /* This should be safe, but for some broken bits of hardware... */
        if (I_IGNPAR(info->tty)) {
                info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
                info->read_status_mask |= UART_LSR_PE | UART_LSR_FE;
        }
#endif
        if (I_IGNBRK(info->tty)) {
                info->ignore_status_mask |= UART_LSR_BI;
                info->read_status_mask |= UART_LSR_BI;
                /*
                 * If we're ignore parity and break indicators, ignore
                 * overruns too.  (For real raw support).
                 */
                if (I_IGNPAR(info->tty)) {
                        info->ignore_status_mask |= UART_LSR_OE |
                                UART_LSR_PE | UART_LSR_FE;
                        info->read_status_mask |= UART_LSR_OE |
                                UART_LSR_PE | UART_LSR_FE;
                }
        }
        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();
}
 
static void rs_put_char(struct tty_struct *tty, unsigned char ch)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_put_char"))
                return;
 
        if (!tty || !info->xmit_buf)
                return;
 
        save_flags_cli (flags);
        if (info->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
                restore_flags(flags);
                return;
        }
 
        info->xmit_buf[info->xmit_head++] = ch;
        info->xmit_head &= SERIAL_XMIT_SIZE-1;
        info->xmit_cnt++;
        restore_flags(flags);
}
 
static void rs_flush_chars(struct tty_struct *tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_flush_chars"))
                return;
 
        if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
            !info->xmit_buf)
                return;
 
        save_flags_cli (flags);
        info->IER |= UART_IER_THRI;
        serial_out(info, UART_IER, info->IER);
        restore_flags(flags);
}
 
static int rs_write(struct tty_struct * tty, int from_user,
                    const unsigned char *buf, int count)
{
        int     c, total = 0;
        struct async_struct *info = (struct async_struct *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_write"))
                return 0;
 
        if (!tty || !info->xmit_buf || !tmp_buf)
                return 0;
 
        if (from_user)
                down(&tmp_buf_sem);
        save_flags(flags);
        while (1) {
                cli();
                c = MIN(count, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
                                   SERIAL_XMIT_SIZE - info->xmit_head));
                if (c <= 0)
                        break;
 
                if (from_user) {
                        memcpy_fromfs(tmp_buf, buf, c);
                        c = MIN(c, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
                                       SERIAL_XMIT_SIZE - info->xmit_head));
                        memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
                } else
                        memcpy(info->xmit_buf + info->xmit_head, buf, c);
                info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
                info->xmit_cnt += c;
                restore_flags(flags);
                buf += c;
                count -= c;
                total += c;
        }
        if (from_user)
                up(&tmp_buf_sem);
        if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped &&
            !(info->IER & UART_IER_THRI)) {
                info->IER |= UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
        restore_flags(flags);
        return total;
}
 
static int rs_write_room(struct tty_struct *tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
        int     ret;
 
        if (serial_paranoia_check(info, tty->device, "rs_write_room"))
                return 0;
        ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
        if (ret < 0)
                ret = 0;
        return ret;
}
 
static int rs_chars_in_buffer(struct tty_struct *tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_chars_in_buffer"))
                return 0;
        return info->xmit_cnt;
}
 
static void rs_flush_buffer(struct tty_struct *tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_flush_buffer"))
                return;
        cli();
        info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
        sti();
        wake_up_interruptible(&tty->write_wait);
        if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
            tty->ldisc.write_wakeup)
                (tty->ldisc.write_wakeup)(tty);
}
 
/*
 * ------------------------------------------------------------
 * rs_throttle()
 *
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
#ifdef SERIAL_DEBUG_THROTTLE
        char    buf[64];
 
        printk("throttle %s: %d....\n", _tty_name(tty, buf),
               tty->ldisc.chars_in_buffer(tty));
#endif
 
        if (serial_paranoia_check(info, tty->device, "rs_throttle"))
                return;
 
        if (I_IXOFF(tty))
                info->x_char = STOP_CHAR(tty);
 
        info->MCR &= ~UART_MCR_RTS;
        info->MCR_noint &= ~UART_MCR_RTS;
        cli();
        serial_out(info, UART_MCR, info->MCR);
        sti();
}
 
static void rs_unthrottle(struct tty_struct * tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
#ifdef SERIAL_DEBUG_THROTTLE
        char    buf[64];
 
        printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
               tty->ldisc.chars_in_buffer(tty));
#endif
 
        if (serial_paranoia_check(info, tty->device, "rs_unthrottle"))
                return;
 
        if (I_IXOFF(tty)) {
                if (info->x_char)
                        info->x_char = 0;
                else
                        info->x_char = START_CHAR(tty);
        }
        info->MCR |= UART_MCR_RTS;
        info->MCR_noint |= UART_MCR_RTS;
        cli();
        serial_out(info, UART_MCR, info->MCR);
        sti();
}
 
/*
 * ------------------------------------------------------------
 * 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.closing_wait = info->closing_wait;
        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 = 0;
 
        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 0
        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;
        }
#else
        if ((new_serial.irq > 31) || (new_serial.type < PORT_UNKNOWN) ||
                (new_serial.type > PORT_MAX)) {
                return -EINVAL;
        }
#endif
 
        /* Make sure address is not already in use */
        if (new_serial.type) {
                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 ((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 * HZ/100;
        info->closing_wait = new_serial.closing_wait * HZ/100;
 
        release_region(info->port,8);
        if (change_port || change_irq) {
                /*
                 * We need to shutdown the serial port at the old
                 * port/irq combination.
                 */
                shutdown(info);
                info->irq = new_serial.irq;
                info->port = new_serial.port;
                info->hub6 = new_serial.hub6;
        }
        if(info->type != PORT_UNKNOWN)
                request_region(info->port,8,"serial(set)");
 
 
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);
        } else
                retval = startup(info);
        return retval;
}
 
 
/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 *          is emptied.  On bus types like RS485, the transmitter must
 *          release the bus after transmitting. This must be done when
 *          the transmit shift register is empty, not be done when the
 *          transmit holding register is empty.  This functionality
 *          allows an RS485 driver to be written in user space.
 */
static int get_lsr_info(struct async_struct * info, unsigned int *value)
{
        unsigned char status;
        unsigned int result;
 
        cli();
        status = serial_in(info, UART_LSR);
        sti();
        result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
        put_user(result,value);
        return 0;
}
 
 
static int get_modem_info(struct async_struct * info, unsigned int *value)
{
        unsigned char control, status;
        unsigned int result;
 
        control = info->MCR;
        cli();
        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_user(result,value);
        return 0;
}
 
static int set_modem_info(struct async_struct * info, unsigned int cmd,
                          unsigned int *value)
{
        int error;
        unsigned int arg;
 
        error = verify_area(VERIFY_READ, value, sizeof(int));
        if (error)
                return error;
        arg = get_user(value);
        switch (cmd) {
        case TIOCMBIS:
                if (arg & TIOCM_RTS) {
                        info->MCR |= UART_MCR_RTS;
                        info->MCR_noint |= UART_MCR_RTS;
                }
                if (arg & TIOCM_DTR) {
                        info->MCR |= UART_MCR_DTR;
                        info->MCR_noint |= UART_MCR_DTR;
                }
                break;
        case TIOCMBIC:
                if (arg & TIOCM_RTS) {
                        info->MCR &= ~UART_MCR_RTS;
                        info->MCR_noint &= ~UART_MCR_RTS;
                }
                if (arg & TIOCM_DTR) {
                        info->MCR &= ~UART_MCR_DTR;
                        info->MCR_noint &= ~UART_MCR_DTR;
                }
                break;
        case TIOCMSET:
                info->MCR = ((info->MCR & ~(UART_MCR_RTS | UART_MCR_DTR))
                             | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
                             | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
                info->MCR_noint = ((info->MCR_noint
                                    & ~(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, info->MCR);
        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);
 
        cli();
        autoconfig(info);
        sti();
 
        retval = startup(info);
        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+HZ/10;
        while (timeout >= jiffies)
                ;
 
        rs_triggered = 0;        /* Reset after letting things settle */
 
        timeout = jiffies+HZ/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 get_multiport_struct(struct async_struct * info,
                                struct serial_multiport_struct *retinfo)
{
        struct serial_multiport_struct ret;
        struct rs_multiport_struct *multi;
 
        multi = &rs_multiport[info->irq];
 
        ret.port_monitor = multi->port_monitor;
 
        ret.port1 = multi->port1;
        ret.mask1 = multi->mask1;
        ret.match1 = multi->match1;
 
        ret.port2 = multi->port2;
        ret.mask2 = multi->mask2;
        ret.match2 = multi->match2;
 
        ret.port3 = multi->port3;
        ret.mask3 = multi->mask3;
        ret.match3 = multi->match3;
 
        ret.port4 = multi->port4;
        ret.mask4 = multi->mask4;
        ret.match4 = multi->match4;
 
        ret.irq = info->irq;
 
        memcpy_tofs(retinfo,&ret,sizeof(*retinfo));
        return 0;
 
}
 
static int set_multiport_struct(struct async_struct * info,
                                struct serial_multiport_struct *in_multi)
{
        struct serial_multiport_struct new_multi;
        struct rs_multiport_struct *multi;
        int     was_multi, now_multi;
        int     retval;
        void (*handler)(int, void *, struct pt_regs *);
 
        if (!suser())
                return -EPERM;
        if (!in_multi)
                return -EFAULT;
        memcpy_fromfs(&new_multi, in_multi,
                      sizeof(struct serial_multiport_struct));
 
        if (new_multi.irq != info->irq || info->irq == 0 ||
            !IRQ_ports[info->irq])
                return -EINVAL;
 
        multi = &rs_multiport[info->irq];
        was_multi = (multi->port1 != 0);
 
        multi->port_monitor = new_multi.port_monitor;
 
        if (multi->port1)
                release_region(multi->port1,1);
        multi->port1 = new_multi.port1;
        multi->mask1 = new_multi.mask1;
        multi->match1 = new_multi.match1;
        if (multi->port1)
                request_region(multi->port1,1,"serial(multiport1)");
 
        if (multi->port2)
                release_region(multi->port2,1);
        multi->port2 = new_multi.port2;
        multi->mask2 = new_multi.mask2;
        multi->match2 = new_multi.match2;
        if (multi->port2)
                request_region(multi->port2,1,"serial(multiport2)");
 
        if (multi->port3)
                release_region(multi->port3,1);
        multi->port3 = new_multi.port3;
        multi->mask3 = new_multi.mask3;
        multi->match3 = new_multi.match3;
        if (multi->port3)
                request_region(multi->port3,1,"serial(multiport3)");
 
        if (multi->port4)
                release_region(multi->port4,1);
        multi->port4 = new_multi.port4;
        multi->mask4 = new_multi.mask4;
        multi->match4 = new_multi.match4;
        if (multi->port4)
                request_region(multi->port4,1,"serial(multiport4)");
 
        now_multi = (multi->port1 != 0);
 
        if (IRQ_ports[info->irq]->next_port &&
            (was_multi != now_multi)) {
                free_irq(info->irq, NULL);
                if (now_multi)
                        handler = rs_interrupt_multi;
                else
                        handler = rs_interrupt;
 
                retval = request_irq(info->irq, handler, IRQ_T(info),
                                     "serial", NULL);
                if (retval) {
                        printk("Couldn't reallocate serial interrupt "
                               "driver!!\n");
                }
        }
 
        return 0;
}
 
static int rs_ioctl(struct tty_struct *tty, struct file * file,
                    unsigned int cmd, unsigned long arg)
{
        int error;
        struct async_struct * info = (struct async_struct *)tty->driver_data;
        int retval;
        struct async_icount cprev, cnow;        /* kernel counter temps */
        struct serial_icounter_struct *p_cuser; /* user space */
 
        if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
                return -ENODEV;
 
        if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
            (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
            (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT) &&
            (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
                if (tty->flags & (1 << TTY_IO_ERROR))
                    return -EIO;
        }
 
        switch (cmd) {
                case TCSBRK:    /* SVID version: non-zero arg --> no break */
                        retval = tty_check_change(tty);
                        if (retval)
                                return retval;
                        tty_wait_until_sent(tty, 0);
                        if (!arg)
                                send_break(info, HZ/4); /* 1/4 second */
                        return 0;
                case TCSBRKP:   /* support for POSIX tcsendbreak() */
                        retval = tty_check_change(tty);
                        if (retval)
                                return retval;
                        tty_wait_until_sent(tty, 0);
                        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:
                        error = verify_area(VERIFY_READ, (void *) arg,sizeof(long));
                        if (error)
                                return error;
                        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:
                        error = verify_area(VERIFY_READ, (void *) arg,
                                                sizeof(struct serial_struct));
                        if (error)
                                return error;
                        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 TIOCSERGETLSR: /* Get line status register */
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                sizeof(unsigned int));
                        if (error)
                                return error;
                        else
                            return get_lsr_info(info, (unsigned int *) arg);
 
                case TIOCSERSWILD:
                        if (!suser())
                                return -EPERM;
                        error = verify_area(VERIFY_READ, (void *) arg,sizeof(long));
                        if (error)
                                return error;
                        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;
 
                case TIOCSERGSTRUCT:
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                                sizeof(struct async_struct));
                        if (error)
                                return error;
                        memcpy_tofs((struct async_struct *) arg,
                                    info, sizeof(struct async_struct));
                        return 0;
 
                case TIOCSERGETMULTI:
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                    sizeof(struct serial_multiport_struct));
                        if (error)
                                return error;
                        return get_multiport_struct(info,
                                       (struct serial_multiport_struct *) arg);
                case TIOCSERSETMULTI:
                        error = verify_area(VERIFY_READ, (void *) arg,
                                    sizeof(struct serial_multiport_struct));
                        if (error)
                                return error;
                        return set_multiport_struct(info,
                                       (struct serial_multiport_struct *) arg);
                /*
                 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
                 * - mask passed in arg for lines of interest
                 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
                 * Caller should use TIOCGICOUNT to see which one it was
                 */
                case TIOCMIWAIT:
                        cli();
                        cprev = info->icount;   /* note the counters on entry */
                        sti();
                        while (1) {
                                interruptible_sleep_on(&info->delta_msr_wait);
                                /* see if a signal did it */
                                if (current->signal & ~current->blocked)
                                        return -ERESTARTSYS;
                                cli();
                                cnow = info->icount;    /* atomic copy */
                                sti();
                                if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
                                    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
                                        return -EIO; /* no change => error */
                                if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
                                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
                                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
                                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
                                        return 0;
                                }
                                cprev = cnow;
                        }
                        /* NOTREACHED */
 
                /*
                 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
                 * Return: write counters to the user passed counter struct
                 * NB: both 1->0 and 0->1 transitions are counted except for
                 *     RI where only 0->1 is counted.
                 */
                case TIOCGICOUNT:
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                sizeof(struct serial_icounter_struct));
                        if (error)
                                return error;
                        cli();
                        cnow = info->icount;
                        sti();
                        p_cuser = (struct serial_icounter_struct *) arg;
                        put_user(cnow.cts, &p_cuser->cts);
                        put_user(cnow.dsr, &p_cuser->dsr);
                        put_user(cnow.rng, &p_cuser->rng);
                        put_user(cnow.dcd, &p_cuser->dcd);
                        return 0;
 
                default:
                        return -ENOIOCTLCMD;
                }
        return 0;
}
 
static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
 
        if (   (tty->termios->c_cflag == old_termios->c_cflag)
            && (   RELEVANT_IFLAG(tty->termios->c_iflag)
                == RELEVANT_IFLAG(old_termios->c_iflag)))
          return;
 
        change_speed(info);
 
        if ((old_termios->c_cflag & CRTSCTS) &&
            !(tty->termios->c_cflag & CRTSCTS)) {
                tty->hw_stopped = 0;
                rs_start(tty);
        }
 
#if 0
        /*
         * No need to wake up processes in open wait, since they
         * sample the CLOCAL flag once, and don't recheck it.
         * XXX  It's not clear whether the current behavior is correct
         * or not.  Hence, this may change.....
         */
        if (!(old_termios->c_cflag & CLOCAL) &&
            (tty->termios->c_cflag & CLOCAL))
                wake_up_interruptible(&info->open_wait);
#endif
}
 
/*
 * ------------------------------------------------------------
 * 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 = (struct async_struct *)tty->driver_data;
        unsigned long flags;
        unsigned long timeout;
 
        if (!info || serial_paranoia_check(info, tty->device, "rs_close"))
                return;
 
        save_flags_cli (flags);
 
        if (tty_hung_up_p(filp)) {
                DBG_CNT("before DEC-hung");
                MOD_DEC_USE_COUNT;
                restore_flags(flags);
                return;
        }
 
#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) {
                DBG_CNT("before DEC-2");
                MOD_DEC_USE_COUNT;
                restore_flags(flags);
                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;
        /*
         * Now we wait for the transmit buffer to clear; and we notify
         * the line discipline to only process XON/XOFF characters.
         */
        tty->closing = 1;
        if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
                tty_wait_until_sent(tty, info->closing_wait);
        /*
         * At this point we stop accepting input.  To do this, we
         * disable the receive line status interrupts, and tell the
         * interrupt driver to stop checking the data ready bit in the
         * line status register.
         */
        info->IER &= ~UART_IER_RLSI;
        info->read_status_mask &= ~UART_LSR_DR;
        if (info->flags & ASYNC_INITIALIZED) {
                serial_out(info, UART_IER, info->IER);
                /*
                 * Before we drop DTR, make sure the UART transmitter
                 * has completely drained; this is especially
                 * important if there is a transmit FIFO!
                 */
                timeout = jiffies+HZ;
                while (!(serial_inp(info, UART_LSR) & UART_LSR_TEMT)) {
                        current->state = TASK_INTERRUPTIBLE;
                        current->timeout = jiffies + info->timeout;
                        schedule();
                        if (jiffies > timeout)
                                break;
                }
        }
        shutdown(info);
        if (tty->driver.flush_buffer)
                tty->driver.flush_buffer(tty);
        if (tty->ldisc.flush_buffer)
                tty->ldisc.flush_buffer(tty);
        tty->closing = 0;
        info->event = 0;
        info->tty = 0;
        if (info->blocked_open) {
                if (info->close_delay) {
                        current->state = TASK_INTERRUPTIBLE;
                        current->timeout = jiffies + info->close_delay;
                        schedule();
                }
                wake_up_interruptible(&info->open_wait);
        }
        info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE|
                         ASYNC_CLOSING);
        wake_up_interruptible(&info->close_wait);
        MOD_DEC_USE_COUNT;
        restore_flags(flags);
}
 
/*
 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
void rs_hangup(struct tty_struct *tty)
{
        struct async_struct * info = (struct async_struct *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_hangup"))
                return;
 
        rs_flush_buffer(tty);
        shutdown(info);
        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 = 0;
 
        /*
         * If the device is in the middle of being closed, then block
         * until it's done, and then try again.
         */
        if (tty_hung_up_p(filp) ||
            (info->flags & ASYNC_CLOSING)) {
                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 (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
                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, or the port is not enabled,
         * then make the check up front and then exit.
         */
        if ((filp->f_flags & O_NONBLOCK) ||
            (tty->flags & (1 << TTY_IO_ERROR))) {
                if (info->flags & ASYNC_CALLOUT_ACTIVE)
                        return -EBUSY;
                info->flags |= ASYNC_NORMAL_ACTIVE;
                return 0;
        }
 
        if (info->flags & ASYNC_CALLOUT_ACTIVE) {
                if (info->normal_termios.c_cflag & CLOCAL)
                        do_clocal = 1;
        } else {
                if (tty->termios->c_cflag & CLOCAL)
                        do_clocal = 1;
        }
 
        /*
         * 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
        cli();
        if (!tty_hung_up_p(filp))
                info->count--;
        sti();
        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-specific
 * initialization for the tty structure.
 */
int rs_open(struct tty_struct *tty, struct file * filp)
{
        struct async_struct     *info;
        int                     retval, line;
        unsigned long           page;
 
        line = MINOR(tty->device) - tty->driver.minor_start;
        if ((line < 0) || (line >= NR_PORTS))
                return -ENODEV;
        info = rs_table + line;
        if (serial_paranoia_check(info, tty->device, "rs_open"))
                return -ENODEV;
 
#ifdef SERIAL_DEBUG_OPEN
        printk("rs_open %s%d, count = %d\n", tty->driver.name, info->line,
               info->count);
#endif
        info->count++;
        tty->driver_data = info;
        info->tty = tty;
 
        if (!tmp_buf) {
                page = get_free_page(GFP_KERNEL);
                if (!page)
                        return -ENOMEM;
                if (tmp_buf)
                        free_page(page);
                else
                        tmp_buf = (unsigned char *) page;
        }
 
        /*
         * Start up serial port
         */
        retval = startup(info);
        if (retval)
                return retval;
 
        MOD_INC_USE_COUNT;
        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;
        }
 
        if ((info->count == 1) && (info->flags & ASYNC_SPLIT_TERMIOS)) {
                if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
                        *tty->termios = info->normal_termios;
                else
                        *tty->termios = info->callout_termios;
                change_speed(info);
        }
 
        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(KERN_INFO "%s version %s with", serial_name, serial_version);
#ifdef CONFIG_HUB6
        printk(" HUB-6");
#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*HZ/100;
        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 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 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_cli (flags);
 
        /*
         * 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.
         */
        scratch = serial_inp(info, UART_IER);
        serial_outp(info, UART_IER, 0);
        outb(0xff, 0x080);
        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
         * manufacturer 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);
 
        scratch2 = serial_in(info, UART_LCR);
        serial_outp(info, UART_LCR, scratch2 | UART_LCR_DLAB);
        serial_outp(info, UART_EFR, 0);  /* EFR is the same as FCR */
        serial_outp(info, UART_LCR, scratch2);
        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:
                        serial_outp(info, UART_LCR, scratch2 | UART_LCR_DLAB);
                        if (serial_in(info, UART_EFR) == 0) {
                                info->type = PORT_16650;
                                info->xmit_fifo_size = 32;
                        } else {
                                info->type = PORT_16550A;
                                info->xmit_fifo_size = 16;
                        }
                        serial_outp(info, UART_LCR, scratch2);
                        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;
        }
        request_region(info->port,8,"serial(auto)");
 
        /*
         * Reset the UART.
         */
#if defined(__alpha__) && !defined(CONFIG_PCI)
        /*
         * I wonder what DEC did to the OUT1 and OUT2 lines?
         * clearing them results in endless interrupts.
         */
        serial_outp(info, UART_MCR, 0x0c);
#else
        serial_outp(info, UART_MCR, 0x00);
#endif
        serial_outp(info, UART_FCR, (UART_FCR_CLEAR_RCVR |
                                     UART_FCR_CLEAR_XMIT));
        (void)serial_in(info, UART_RX);
 
        restore_flags(flags);
}
 
int register_serial(struct serial_struct *req);
void unregister_serial(int line);
 
static struct symbol_table serial_syms = {
#include <linux/symtab_begin.h>
        X(register_serial),
        X(unregister_serial),
#include <linux/symtab_end.h>
};
 
/*
 * The serial driver boot-time initialization code!
 */
int rs_init(void)
{
        int i;
        struct async_struct * info;
#ifdef CONFIG_ATOMWIDE_SERIAL
        extern void atomwide_serial_init (void);
 
        atomwide_serial_init ();
#endif
 
        init_bh(SERIAL_BH, do_serial_bh);
        timer_table[RS_TIMER].fn = rs_timer;
        timer_table[RS_TIMER].expires = 0;
#ifdef CONFIG_AUTO_IRQ
        rs_wild_int_mask = check_wild_interrupts(1);
#endif
 
        for (i = 0; i < 32; i++) {
                IRQ_ports[i] = 0;
                IRQ_timeout[i] = 0;
                memset(&rs_multiport[i], 0, sizeof(struct rs_multiport_struct));
        }
 
        show_serial_version();
 
        /* Initialize the tty_driver structure */
 
        memset(&serial_driver, 0, sizeof(struct tty_driver));
        serial_driver.magic = TTY_DRIVER_MAGIC;
        serial_driver.name = "ttyS";
        serial_driver.major = TTY_MAJOR;
        serial_driver.minor_start = 64;
        serial_driver.num = NR_PORTS;
        serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
        serial_driver.subtype = SERIAL_TYPE_NORMAL;
        serial_driver.init_termios = tty_std_termios;
        serial_driver.init_termios.c_cflag =
                B9600 | CS8 | CREAD | HUPCL | CLOCAL;
        serial_driver.flags = TTY_DRIVER_REAL_RAW;
        serial_driver.refcount = &serial_refcount;
        serial_driver.table = serial_table;
        serial_driver.termios = serial_termios;
        serial_driver.termios_locked = serial_termios_locked;
 
        serial_driver.open = rs_open;
        serial_driver.close = rs_close;
        serial_driver.write = rs_write;
        serial_driver.put_char = rs_put_char;
        serial_driver.flush_chars = rs_flush_chars;
        serial_driver.write_room = rs_write_room;
        serial_driver.chars_in_buffer = rs_chars_in_buffer;
        serial_driver.flush_buffer = rs_flush_buffer;
        serial_driver.ioctl = rs_ioctl;
        serial_driver.throttle = rs_throttle;
        serial_driver.unthrottle = rs_unthrottle;
        serial_driver.set_termios = rs_set_termios;
        serial_driver.stop = rs_stop;
        serial_driver.start = rs_start;
        serial_driver.hangup = rs_hangup;
 
        /*
         * The callout device is just like normal device except for
         * major number and the subtype code.
         */
        callout_driver = serial_driver;
        callout_driver.name = "cua";
        callout_driver.major = TTYAUX_MAJOR;
        callout_driver.subtype = SERIAL_TYPE_CALLOUT;
 
        if (tty_register_driver(&serial_driver))
                panic("Couldn't register serial driver\n");
        if (tty_register_driver(&callout_driver))
                panic("Couldn't register callout driver\n");
 
        for (i = 0, info = rs_table; i < NR_PORTS; i++,info++) {
                info->magic = SERIAL_MAGIC;
                info->line = i;
                info->tty = 0;
                info->type = PORT_UNKNOWN;
                info->custom_divisor = 0;
                info->close_delay = 5*HZ/10;
                info->closing_wait = 30*HZ;
                info->x_char = 0;
                info->event = 0;
                info->count = 0;
                info->blocked_open = 0;
                info->tqueue.routine = do_softint;
                info->tqueue.data = info;
                info->tqueue_hangup.routine = do_serial_hangup;
                info->tqueue_hangup.data = info;
                info->callout_termios =callout_driver.init_termios;
                info->normal_termios = serial_driver.init_termios;
                info->open_wait = 0;
                info->close_wait = 0;
                info->delta_msr_wait = 0;
                info->icount.cts = info->icount.dsr =
                        info->icount.rng = info->icount.dcd = 0;
                info->next_port = 0;
                info->prev_port = 0;
#if 0
                if (info->irq == 2)
                        info->irq = 9;
#endif
                if (info->type == PORT_UNKNOWN) {
                        if (!(info->flags & ASYNC_BOOT_AUTOCONF))
                                continue;
                        autoconfig(info);
                        if (info->type == PORT_UNKNOWN)
                                continue;
                }
                printk(KERN_INFO "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;
                        case PORT_16650:
                                printk(" is a 16650\n");
                                break;
                        default:
                                printk("\n");
                                break;
                }
        }
        register_symtab(&serial_syms);
        return 0;
}
 
int register_pre_init_serial (struct serial_struct *req)
{
        int i;
        struct async_struct *info;
 
        for (i = 0; i < NR_PORTS; i++) {
                if (rs_table[i].port == req->port)
                        break;
        }
 
        if (i == NR_PORTS) {
                for (i = 0; i < NR_PORTS; i++)
                        if (!rs_table[i].port)
                                break;
        }
        if (i == NR_PORTS)
                return -1;
 
        info = &rs_table[i];
        if (info->count) {
                printk ("Couldn't configure serial #%d (port=%d, irq=%d): "
                        "device already open\n", i, req->port, req->irq);
                return -1;
        }
        info->irq = req->irq;
        info->port = req->port;
        info->baud_base = req->baud_base;
        serial_outp (info, UART_IER, 0);
        return 0;
}
 
/*
 * register_serial and unregister_serial allows for serial ports to be
 * configured at run-time, to support PCMCIA modems.
 */
int register_serial(struct serial_struct *req)
{
        int i;
        unsigned long flags;
        struct async_struct *info;
 
        save_flags_cli (flags);
        for (i = 0; i < NR_PORTS; i++) {
                if (rs_table[i].port == req->port)
                        break;
        }
        if (i == NR_PORTS) {
                for (i = 0; i < NR_PORTS; i++)
                        if ((rs_table[i].type == PORT_UNKNOWN) &&
                            (rs_table[i].count == 0))
                                break;
        }
        if (i == NR_PORTS) {
                restore_flags(flags);
                return -1;
        }
        info = &rs_table[i];
        if (rs_table[i].count) {
                restore_flags(flags);
                printk("Couldn't configure serial #%d (port=%d,irq=%d): "
                       "device already open\n", i, req->port, req->irq);
                return -1;
        }
        info->irq = req->irq;
        info->port = req->port;
        if (req->baud_base)     /* rmk: need this to set the baud rate... */
                info->baud_base = req->baud_base;
        serial_outp(info, UART_IER, 0); /* rmk: need to make sure port is disabled */
        info->flags = req->flags;
        autoconfig(info);
        if (info->type == PORT_UNKNOWN) {
                restore_flags(flags);
                printk("register_serial(): autoconfig failed\n");
                return -1;
        }
        printk(KERN_INFO "tty%02d at 0x%04x (irq = %d)", info->line,
               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;
        }
        restore_flags(flags);
        register_symtab(&serial_syms);
        return info->line;
}
 
void unregister_serial(int line)
{
        unsigned long flags;
        struct async_struct *info = &rs_table[line];
 
        save_flags_cli (flags);
        if (info->tty)
                tty_hangup(info->tty);
        info->type = PORT_UNKNOWN;
        release_region(info->port,8);
        printk(KERN_INFO "tty%02d unloaded\n", info->line);
        restore_flags(flags);
}
 
#ifdef MODULE
int init_module(void)
{
        return rs_init();
}
 
void cleanup_module(void)
{
        unsigned long flags;
        int e1, e2;
        int i;
 
        /* printk("Unloading %s: version %s\n", serial_name, serial_version); */
        save_flags_cli(flags);
        timer_active &= ~(1 << RS_TIMER);
        timer_table[RS_TIMER].fn = NULL;
        timer_table[RS_TIMER].expires = 0;
        if ((e1 = tty_unregister_driver(&serial_driver)))
                printk("SERIAL: failed to unregister serial driver (%d)\n",
                       e1);
        if ((e2 = tty_unregister_driver(&callout_driver)))
                printk("SERIAL: failed to unregister callout driver (%d)\n",
                       e2);
        restore_flags(flags);
 
        for (i = 0; i < NR_PORTS; i++) {
                if (rs_table[i].type != PORT_UNKNOWN)
                        release_region(rs_table[i].port, 8);
        }
        if (tmp_buf) {
                free_page((unsigned long)tmp_buf);
                tmp_buf = NULL;
        }
}
#endif /* MODULE */
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[/] [or1k_old/] [trunk/] [rc203soc/] [sw/] [uClinux/] [arch/] [armnommu/] [drivers/] [char/] [serial.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1622	jcastillo	`/*`
2			`* linux/arch/arm/drivers/char/serial.c`
3			`*`
4			`* Copyright (C) 1991, 1992 Linus Torvalds`
5			`*`
6			`* Extensively rewritten by Theodore Ts'o, 8/16/92 -- 9/14/92. Now`
7			`* much more extensible to support other serial cards based on the`
8			`* 16450/16550A UART's. Added support for the AST FourPort and the`
9			`* Accent Async board.`
10			`*`
11			`* set_serial_info fixed to set the flags, custom divisor, and uart`
12			`* type fields. Fix suggested by Michael K. Johnson 12/12/92.`
13			`*`
14			`* 11/95: TIOCMIWAIT, TIOCGICOUNT by Angelo Haritsis <ah@doc.ic.ac.uk>`
15			`*`
16			`* 03/96: Modularised by Angelo Haritsis <ah@doc.ic.ac.uk>`
17			`*`
18			`* rs_set_termios fixed to look also for changes of the input`
19			`* flags INPCK, BRKINT, PARMRK, IGNPAR and IGNBRK.`
20			`* Bernd Anh�upl 05/17/96.`
21			`*`
22			`* This module exports the following rs232 io functions:`
23			`*`
24			`* int rs_init(void);`
25			`* int rs_open(struct tty_struct * tty, struct file * filp)`
26			`*`
27			`* Slight modifications for ARM Copyright (C) 1995, 1996 Russell King`
28			`*/`
29
30			`#include <linux/module.h>`
31			`#include <linux/errno.h>`
32			`#include <linux/signal.h>`
33			`#include <linux/sched.h>`
34			`#include <linux/timer.h>`
35			`#include <linux/interrupt.h>`
36			`#include <linux/tty.h>`
37			`#include <linux/tty_flip.h>`
38			`#include <linux/serial.h>`
39			`#include <linux/serial_reg.h>`
40			`#include <linux/config.h>`