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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [au1x00-serial.c] - Blame information for rev 1774

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/*
 *
 * BRIEF MODULE DESCRIPTION
 *      Au1x00 serial port driver.
 *
 * Copyright 2001 MontaVista Software Inc.
 * Author: MontaVista Software, Inc.
 *              ppopov@mvista.com or source@mvista.com
 *
 *  Derived almost entirely from drivers/char/serial.c:
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
 *              1998, 1999  Theodore Ts'o
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
static char *serial_version = "1.01";
static char *serial_revdate = "2001-02-08";
 
 
#include <linux/config.h>
#include <linux/version.h>
 
#undef SERIAL_PARANOIA_CHECK
#define CONFIG_SERIAL_NOPAUSE_IO
#define SERIAL_DO_RESTART
 
 
/* Set of debugging defines */
 
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
#undef SERIAL_DEBUG_PCI
#undef SERIAL_DEBUG_AUTOCONF
 
#ifdef MODULE
#undef CONFIG_AU1X00_SERIAL_CONSOLE
#endif
 
#define CONFIG_SERIAL_RSA
 
#define RS_STROBE_TIME (10*HZ)
#define RS_ISR_PASS_LIMIT 256
 
/*
 * End of serial driver configuration section.
 */
 
#include <linux/module.h>
 
#include <linux/types.h>
#ifdef LOCAL_HEADERS
#include "serial_local.h"
#else
#include <linux/serial.h>
#include <linux/serialP.h>
#include <asm/au1000.h>
#include <asm/serial.h>
#define LOCAL_VERSTRING ""
#endif
 
#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/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <linux/delay.h>
#ifdef CONFIG_AU1X00_SERIAL_CONSOLE
#include <linux/console.h>
#endif
#ifdef CONFIG_MAGIC_SYSRQ
#include <linux/sysrq.h>
#endif
 
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/bitops.h>
 
#ifdef CONFIG_MAC_SERIAL
#define SERIAL_DEV_OFFSET       2
#else
#define SERIAL_DEV_OFFSET       0
#endif
 
#ifdef SERIAL_INLINE
#define _INLINE_ inline
#else
#define _INLINE_
#endif
 
static char *serial_name = "Serial driver";
 
static DECLARE_TASK_QUEUE(tq_serial);
 
static struct tty_driver serial_driver, callout_driver;
static int serial_refcount;
 
static struct timer_list serial_timer;
 
extern unsigned long get_au1x00_uart_baud_base(void);
 
/* serial subtype definitions */
#ifndef SERIAL_TYPE_NORMAL
#define SERIAL_TYPE_NORMAL      1
#define SERIAL_TYPE_CALLOUT     2
#endif
 
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
 
/*
 * 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 int IRQ_timeout[NR_IRQS];
#ifdef CONFIG_AU1X00_SERIAL_CONSOLE
static struct console sercons;
static int lsr_break_flag;
#endif
#if defined(CONFIG_AU1X00_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
static unsigned long break_pressed; /* break, really ... */
#endif
 
static void autoconfig(struct serial_state * state);
static void change_speed(struct async_struct *info, struct termios *old);
static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 
/*
 * Here we define the default xmit fifo size used for each type of
 * UART
 */
static struct serial_uart_config uart_config[] = {
        { "unknown", 1, 0 },
        { "8250", 1, 0 },
        { "16450", 1, 0 },
        { "16550", 1, 0 },
        { 0, 0}
};
 
 
static struct serial_state rs_table[RS_TABLE_SIZE] = {
        SERIAL_PORT_DFNS        /* Defined in serial.h */
};
 
#define NR_PORTS        (sizeof(rs_table)/sizeof(struct serial_state))
 
#ifndef PREPARE_FUNC
#define PREPARE_FUNC(dev)  (dev->prepare)
#define ACTIVATE_FUNC(dev)  (dev->activate)
#define DEACTIVATE_FUNC(dev)  (dev->deactivate)
#endif
 
#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
 
static struct tty_struct *serial_table[NR_PORTS];
static struct termios *serial_termios[NR_PORTS];
static struct termios *serial_termios_locked[NR_PORTS];
 
 
#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
 
/*
 * tmp_buf is used as a temporary buffer by serial_write.  We need to
 * lock it in case the copy_from_user 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;
#ifdef DECLARE_MUTEX
static DECLARE_MUTEX(tmp_buf_sem);
#else
static struct semaphore tmp_buf_sem = MUTEX;
#endif
 
static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED;
 
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;
}
 
static _INLINE_ unsigned int serial_in(struct async_struct *info, int offset)
{
        return (au_readl(info->port+offset) & 0xffff);
}
 
static _INLINE_ void serial_out(struct async_struct *info, int offset, int value)
{
        au_writel(value & 0xffff, info->port+offset);
}
 
 
/*
 * We used to support using pause I/O for certain machines.  We
 * haven't supported this for a while, but just in case it's badly
 * needed for certain old 386 machines, I've left these #define's
 * in....
 */
#define serial_inp(info, offset)                serial_in(info, offset)
#define serial_outp(info, offset, value)        serial_out(info, offset, value)
 
 
/*
 * ------------------------------------------------------------
 * 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;
 
        spin_lock_irqsave(&serial_lock, flags);
        if (info->IER & UART_IER_THRI) {
                info->IER &= ~UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
        spin_unlock_irqrestore(&serial_lock, 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;
 
        spin_lock_irqsave(&serial_lock, flags);
        if (info->xmit.head != info->xmit.tail
            && info->xmit.buf
            && !(info->IER & UART_IER_THRI)) {
                info->IER |= UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
        spin_unlock_irqrestore(&serial_lock, 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 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(&info->tqueue, &tq_serial);
        mark_bh(SERIAL_BH);
}
 
static _INLINE_ void receive_chars(struct async_struct *info,
                                 int *status, struct pt_regs * regs)
{
        struct tty_struct *tty = info->tty;
        unsigned char ch;
        int ignored = 0;
        struct  async_icount *icount;
 
        icount = &info->state->icount;
        do {
                ch = serial_inp(info, UART_RX);
                if (tty->flip.count >= TTY_FLIPBUF_SIZE)
                        goto ignore_char;
                *tty->flip.char_buf_ptr = ch;
                icount->rx++;
 
#ifdef SERIAL_DEBUG_INTR
                printk("DR%02x:%02x...", ch, *status);
#endif
                *tty->flip.flag_buf_ptr = 0;
                if (*status & (UART_LSR_BI | UART_LSR_PE |
                               UART_LSR_FE | UART_LSR_OE)) {
                        /*
                         * For statistics only
                         */
                        if (*status & UART_LSR_BI) {
                                *status &= ~(UART_LSR_FE | UART_LSR_PE);
                                icount->brk++;
                                /*
                                 * We do the SysRQ and SAK checking
                                 * here because otherwise the break
                                 * may get masked by ignore_status_mask
                                 * or read_status_mask.
                                 */
#if defined(CONFIG_AU1X00_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
                                if (info->line == sercons.index) {
                                        if (!break_pressed) {
                                                break_pressed = jiffies;
                                                goto ignore_char;
                                        }
                                        break_pressed = 0;
                                }
#endif
                                if (info->flags & ASYNC_SAK)
                                        do_SAK(tty);
                        } else if (*status & UART_LSR_PE)
                                icount->parity++;
                        else if (*status & UART_LSR_FE)
                                icount->frame++;
                        if (*status & UART_LSR_OE)
                                icount->overrun++;
 
                        /*
                         * Now check to see if character should be
                         * ignored, and mask off conditions which
                         * should be ignored.
                         */
                        if (*status & info->ignore_status_mask) {
                                if (++ignored > 100)
                                        break;
                                goto ignore_char;
                        }
                        *status &= info->read_status_mask;
 
#ifdef CONFIG_AU1X00_SERIAL_CONSOLE
                        if (info->line == sercons.index) {
                                /* Recover the break flag from console xmit */
                                *status |= lsr_break_flag;
                                lsr_break_flag = 0;
                        }
#endif
                        if (*status & (UART_LSR_BI)) {
#ifdef SERIAL_DEBUG_INTR
                                printk("handling break....");
#endif
                                *tty->flip.flag_buf_ptr = TTY_BREAK;
                        } 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;
                        if (*status & UART_LSR_OE) {
                                /*
                                 * Overrun is special, since it's
                                 * reported immediately, and doesn't
                                 * affect the current character
                                 */
                                tty->flip.count++;
                                tty->flip.flag_buf_ptr++;
                                tty->flip.char_buf_ptr++;
                                *tty->flip.flag_buf_ptr = TTY_OVERRUN;
                                if (tty->flip.count >= TTY_FLIPBUF_SIZE)
                                        goto ignore_char;
                        }
                }
#if defined(CONFIG_AU1X00_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
                if (break_pressed && info->line == sercons.index) {
                        if (ch != 0 &&
                            time_before(jiffies, break_pressed + HZ*5)) {
                                handle_sysrq(ch, regs, NULL, NULL);
                                break_pressed = 0;
                                goto ignore_char;
                        }
                        break_pressed = 0;
                }
#endif
                tty->flip.flag_buf_ptr++;
                tty->flip.char_buf_ptr++;
                tty->flip.count++;
        ignore_char:
                *status = serial_inp(info, UART_LSR);
        } while (*status & UART_LSR_DR);
        tty_flip_buffer_push(tty);
}
 
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->state->icount.tx++;
                info->x_char = 0;
                if (intr_done)
                        *intr_done = 0;
                return;
        }
        if (info->xmit.head == info->xmit.tail
            || 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 + 1) & (SERIAL_XMIT_SIZE-1);
                info->state->icount.tx++;
                if (info->xmit.head == info->xmit.tail)
                        break;
        } while (--count > 0);
 
        if (CIRC_CNT(info->xmit.head,
                     info->xmit.tail,
                     SERIAL_XMIT_SIZE) < 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.head == info->xmit.tail) {
                info->IER &= ~UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
}
 
static _INLINE_ void check_modem_status(struct async_struct *info)
{
        int     status;
        struct  async_icount *icount;
 
        status = serial_in(info, UART_MSR);
 
        if (status & UART_MSR_ANY_DELTA) {
                icount = &info->state->icount;
                /* update input line counters */
                if (status & UART_MSR_TERI)
                        icount->rng++;
                if (status & UART_MSR_DDSR)
                        icount->dsr++;
                if (status & UART_MSR_DDCD) {
                        icount->dcd++;
#ifdef CONFIG_HARD_PPS
                        if ((info->flags & ASYNC_HARDPPS_CD) &&
                            (status & UART_MSR_DCD))
                                hardpps();
#endif
                }
                if (status & UART_MSR_DCTS)
                        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("doing serial hangup...");
#endif
                        if (info->tty)
                                tty_hangup(info->tty);
                }
        }
        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 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;
        struct async_struct * info;
 
#ifdef SERIAL_DEBUG_INTR
        printk("rs_interrupt_single(%d)...", irq);
#endif
 
        info = IRQ_ports[irq];
        if (!info || !info->tty)
                return;
 
        do {
                status = serial_inp(info, UART_LSR);
#ifdef SERIAL_DEBUG_INTR
                printk("status = %x...", status);
#endif
                if (status & UART_LSR_DR)
                        receive_chars(info, &status, regs);
                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;
#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 (test_and_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);
#ifdef SERIAL_HAVE_POLL_WAIT
                wake_up_interruptible(&tty->poll_wait);
#endif
        }
}
 
/*
 * 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(unsigned long dummy)
{
        static unsigned long last_strobe;
        struct async_struct *info;
        unsigned int    i;
        unsigned long flags;
 
        if ((jiffies - last_strobe) >= RS_STROBE_TIME) {
                for (i=0; i < NR_IRQS; i++) {
                        info = IRQ_ports[i];
                        if (!info)
                                continue;
                        spin_lock_irqsave(&serial_lock, flags);
                                rs_interrupt_single(i, NULL, NULL);
                                spin_unlock_irqrestore(&serial_lock, flags);
                }
        }
        last_strobe = jiffies;
        mod_timer(&serial_timer, jiffies + RS_STROBE_TIME);
 
#if 0
        if (IRQ_ports[0]) {
                spin_lock_irqsave(&serial_lock, flags);
                rs_interrupt_single(0, NULL, NULL);
                spin_unlock_irqrestore(&serial_lock, flags);
 
                mod_timer(&serial_timer, jiffies + IRQ_timeout[0]);
        }
#endif
}
 
/*
 * ---------------------------------------------------------------
 * 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.
 * ---------------------------------------------------------------
 */
 
/*
 * 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 > 3) ? timeout-2 : 1;
}
 
 
static int startup(struct async_struct * info)
{
        unsigned long flags;
        int     retval=0;
        void (*handler)(int, void *, struct pt_regs *);
        struct serial_state *state= info->state;
        unsigned long page;
 
        page = get_zeroed_page(GFP_KERNEL);
        if (!page)
                return -ENOMEM;
 
        spin_lock_irqsave(&serial_lock, flags);
 
        if (info->flags & ASYNC_INITIALIZED) {
                free_page(page);
                goto errout;
        }
 
        if (!CONFIGURED_SERIAL_PORT(state) || !state->type) {
                if (info->tty)
                        set_bit(TTY_IO_ERROR, &info->tty->flags);
                free_page(page);
                goto errout;
        }
        if (info->xmit.buf)
                free_page(page);
        else
                info->xmit.buf = (unsigned char *) page;
 
 
        if (au_readl(UART_MOD_CNTRL + state->port) != 0x3) {
                au_writel(3, UART_MOD_CNTRL + state->port);
                au_sync_delay(10);
        }
#ifdef SERIAL_DEBUG_OPEN
        printk("starting up ttys%d (irq %d)...", info->line, state->irq);
#endif
 
 
        /*
         * Clear the FIFO buffers and disable them
         * (they will be reenabled in change_speed())
         */
        if (uart_config[state->type].flags & UART_CLEAR_FIFO) {
                serial_outp(info, UART_FCR, UART_FCR_ENABLE_FIFO);
                serial_outp(info, UART_FCR, (UART_FCR_ENABLE_FIFO |
                                             UART_FCR_CLEAR_RCVR |
                                             UART_FCR_CLEAR_XMIT));
                serial_outp(info, UART_FCR, 0);
        }
 
        /*
         * 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);
 
        /*
         * 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 (!(info->flags & ASYNC_BUGGY_UART) &&
            (serial_inp(info, UART_LSR) == 0xff)) {
                printk("LSR safety check engaged!\n");
                if (capable(CAP_SYS_ADMIN)) {
                        if (info->tty)
                                set_bit(TTY_IO_ERROR, &info->tty->flags);
                } else
                        retval = -ENODEV;
                goto errout;
        }
 
        /*
         * Allocate the IRQ if necessary
         */
#if 0
        /* au1000, uart0 irq is 0 */
        if (state->irq && (!IRQ_ports[state->irq] || !IRQ_ports[state->irq]->next_port)) {
#endif
        if ((!IRQ_ports[state->irq] || !IRQ_ports[state->irq]->next_port)) {
                if (IRQ_ports[state->irq]) {
                        retval = -EBUSY;
                        goto errout;
                } else
                        handler = rs_interrupt_single;
 
                retval = request_irq(state->irq, handler, SA_SHIRQ,
                                     "serial", &IRQ_ports[state->irq]);
                if (retval) {
                        if (capable(CAP_SYS_ADMIN)) {
                                if (info->tty)
                                        set_bit(TTY_IO_ERROR,
                                                &info->tty->flags);
                                retval = 0;
                        }
                        goto errout;
                }
        }
 
        /*
         * Insert serial port into IRQ chain.
         */
        info->prev_port = 0;
        info->next_port = IRQ_ports[state->irq];
        if (info->next_port)
                info->next_port->prev_port = info;
        IRQ_ports[state->irq] = info;
        figure_IRQ_timeout(state->irq);
 
        /*
         * Now, initialize the UART
         */
        serial_outp(info, UART_LCR, UART_LCR_WLEN8);
 
        info->MCR = 0;
        if (info->tty->termios->c_cflag & CBAUD)
                info->MCR = UART_MCR_DTR | UART_MCR_RTS;
        {
                if (state->irq != 0)
                        info->MCR |= UART_MCR_OUT2;
        }
        info->MCR |= ALPHA_KLUDGE_MCR;          /* Don't ask */
        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 */
 
 
        /*
         * 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.head = info->xmit.tail = 0;
 
        /*
         * Set up serial timers...
         */
        mod_timer(&serial_timer, jiffies + 2*HZ/100);
 
        /*
         * Set up the tty->alt_speed kludge
         */
        if (info->tty) {
                if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
                        info->tty->alt_speed = 57600;
                if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
                        info->tty->alt_speed = 115200;
                if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
                        info->tty->alt_speed = 230400;
                if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
                        info->tty->alt_speed = 460800;
        }
 
        /*
         * and set the speed of the serial port
         */
        change_speed(info, 0);
 
        info->flags |= ASYNC_INITIALIZED;
        spin_unlock_irqrestore(&serial_lock, flags);
        return 0;
 
errout:
        spin_unlock_irqrestore(&serial_lock, flags);
        return retval;
}
 
/*
 * 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;
        struct serial_state *state;
        int             retval;
 
        if (!(info->flags & ASYNC_INITIALIZED))
                return;
 
        state = info->state;
 
#ifdef SERIAL_DEBUG_OPEN
        printk("Shutting down serial port %d (irq %d)....", info->line,
               state->irq);
#endif
 
        spin_lock_irqsave(&serial_lock, flags);
 
        /*
         * 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[state->irq] = info->next_port;
        figure_IRQ_timeout(state->irq);
 
        /*
         * Free the IRQ, if necessary
         */
//      if (state->irq && (!IRQ_ports[state->irq] ||
        if ((!IRQ_ports[state->irq] ||
                          !IRQ_ports[state->irq]->next_port)) {
                if (IRQ_ports[state->irq]) {
                        free_irq(state->irq, &IRQ_ports[state->irq]);
                        retval = request_irq(state->irq, rs_interrupt_single,
                                             SA_SHIRQ, "serial",
                                             &IRQ_ports[state->irq]);
 
                        if (retval)
                                printk("serial shutdown: request_irq: error %d"
                                       "  Couldn't reacquire IRQ.\n", retval);
                } else
                        free_irq(state->irq, &IRQ_ports[state->irq]);
        }
 
        if (info->xmit.buf) {
                unsigned long pg = (unsigned long) info->xmit.buf;
                info->xmit.buf = 0;
                free_page(pg);
        }
 
        info->IER = 0;
        serial_outp(info, UART_IER, 0x00);      /* disable all intrs */
                info->MCR &= ~UART_MCR_OUT2;
        info->MCR |= ALPHA_KLUDGE_MCR;          /* Don't ask */
 
        /* disable break condition */
        serial_out(info, UART_LCR, serial_inp(info, UART_LCR) & ~UART_LCR_SBC);
 
        if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
                info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
        serial_outp(info, UART_MCR, info->MCR);
 
        /* disable FIFO's */
        serial_outp(info, UART_FCR, (UART_FCR_ENABLE_FIFO |
                                     UART_FCR_CLEAR_RCVR |
                                     UART_FCR_CLEAR_XMIT));
        serial_outp(info, UART_FCR, 0);
 
        (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;
#ifndef CONFIG_KGDB
        au_writel(0, UART_MOD_CNTRL + state->port);
        au_sync_delay(10);
#endif
        spin_unlock_irqrestore(&serial_lock, 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,
                         struct termios *old_termios)
{
        int     quot = 0, baud_base, baud;
        unsigned cflag, cval, fcr = 0;
        int     bits;
        unsigned long   flags;
 
        if (!info->tty || !info->tty->termios)
                return;
        cflag = info->tty->termios->c_cflag;
        if (!CONFIGURED_SERIAL_PORT(info))
                return;
 
        /* byte size and parity */
        switch (cflag & CSIZE) {
              case CS5: cval = 0x00; bits = 7; break;
              case CS6: cval = 0x01; bits = 8; break;
              case CS7: cval = 0x02; bits = 9; break;
              case CS8: cval = 0x03; bits = 10; break;
              /* Never happens, but GCC is too dumb to figure it out */
              default:  cval = 0x00; bits = 7; break;
              }
        if (cflag & CSTOPB) {
                cval |= 0x04;
                bits++;
        }
        if (cflag & PARENB) {
                cval |= UART_LCR_PARITY;
                bits++;
        }
        if (!(cflag & PARODD))
                cval |= UART_LCR_EPAR;
#ifdef CMSPAR
        if (cflag & CMSPAR)
                cval |= UART_LCR_SPAR;
#endif
 
        /* Determine divisor based on baud rate */
        baud = tty_get_baud_rate(info->tty);
        if (!baud) {
                baud = 9600;    /* B0 transition handled in rs_set_termios */
        }
        baud_base = get_au1x00_uart_baud_base();
 
        //if (baud == 38400 &&
        if (((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)) {
                quot = info->state->custom_divisor;
        }
        else {
                if (baud == 134)
                        /* Special case since 134 is really 134.5 */
                        quot = (2*baud_base / 269);
                else if (baud)
                        quot = baud_base / baud;
        }
        /* If the quotient is zero refuse the change */
        if (!quot && old_termios) {
                info->tty->termios->c_cflag &= ~CBAUD;
                info->tty->termios->c_cflag |= (old_termios->c_cflag & CBAUD);
                baud = tty_get_baud_rate(info->tty);
                if (!baud)
                        baud = 9600;
                if (baud == 38400 &&
                    ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
                        quot = info->state->custom_divisor;
                else {
                        if (baud == 134)
                                /* Special case since 134 is really 134.5 */
                                quot = (2*baud_base / 269);
                        else if (baud)
                                quot = baud_base / baud;
                }
        }
        /* As a last resort, if the quotient is zero, default to 9600 bps */
        if (!quot)
                quot = baud_base / 9600;
 
        info->quot = quot;
        info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
        info->timeout += HZ/50;         /* Add .02 seconds of slop */
 
        /* Set up FIFO's */
        if (uart_config[info->state->type].flags & UART_USE_FIFO) {
                if ((info->state->baud_base / quot) < 2400)
                        fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIGGER_1;
                else
                        fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIGGER_8;
        }
 
        /* CTS flow control flag and modem status interrupts */
        info->IER &= ~UART_IER_MSI;
        if (info->flags & ASYNC_HARDPPS_CD)
                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;
 
        /*
         * Characters to ignore
         */
        info->ignore_status_mask = 0;
        if (I_IGNPAR(info->tty))
                info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
        if (I_IGNBRK(info->tty)) {
                info->ignore_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;
        }
        /*
         * !!! ignore all characters if CREAD is not set
         */
        if ((cflag & CREAD) == 0)
                info->ignore_status_mask |= UART_LSR_DR;
        spin_lock_irqsave(&serial_lock, flags);
 
        serial_outp(info, UART_CLK, quot & 0xffff);
        serial_outp(info, UART_LCR, cval);
        info->LCR = cval;                               /* Save LCR */
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
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;
 
        spin_lock_irqsave(&serial_lock, flags);
        if (CIRC_SPACE(info->xmit.head,
                       info->xmit.tail,
                       SERIAL_XMIT_SIZE) == 0) {
                spin_unlock_irqrestore(&serial_lock, flags);
                return;
        }
 
        info->xmit.buf[info->xmit.head] = ch;
        info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
        spin_unlock_irqrestore(&serial_lock, 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.head == info->xmit.tail
            || tty->stopped
            || tty->hw_stopped
            || !info->xmit.buf)
                return;
 
        spin_lock_irqsave(&serial_lock, flags);
        info->IER |= UART_IER_THRI;
        serial_out(info, UART_IER, info->IER);
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
static int rs_write(struct tty_struct * tty, int from_user,
                    const unsigned char *buf, int count)
{
        int     c, ret = 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;
 
        spin_lock_irqsave(&serial_lock, flags);
        if (from_user) {
                down(&tmp_buf_sem);
                while (1) {
                        int c1;
                        c = CIRC_SPACE_TO_END(info->xmit.head,
                                              info->xmit.tail,
                                              SERIAL_XMIT_SIZE);
                        if (count < c)
                                c = count;
                        if (c <= 0)
                                break;
 
                        c -= copy_from_user(tmp_buf, buf, c);
                        if (!c) {
                                if (!ret)
                                        ret = -EFAULT;
                                break;
                        }
                        cli();
                        c1 = CIRC_SPACE_TO_END(info->xmit.head,
                                               info->xmit.tail,
                                               SERIAL_XMIT_SIZE);
                        if (c1 < c)
                                c = c1;
                        memcpy(info->xmit.buf + info->xmit.head, tmp_buf, c);
                        info->xmit.head = ((info->xmit.head + c) &
                                           (SERIAL_XMIT_SIZE-1));
                        spin_unlock_irqrestore(&serial_lock, flags);
                        buf += c;
                        count -= c;
                        ret += c;
                }
                up(&tmp_buf_sem);
        } else {
                cli();
                while (1) {
                        c = CIRC_SPACE_TO_END(info->xmit.head,
                                              info->xmit.tail,
                                              SERIAL_XMIT_SIZE);
                        if (count < c)
                                c = count;
                        if (c <= 0) {
                                break;
                        }
                        memcpy(info->xmit.buf + info->xmit.head, buf, c);
                        info->xmit.head = ((info->xmit.head + c) &
                                           (SERIAL_XMIT_SIZE-1));
                        buf += c;
                        count -= c;
                        ret += c;
                }
                spin_unlock_irqrestore(&serial_lock, flags);
        }
        if (info->xmit.head != info->xmit.tail
            && !tty->stopped
            && !tty->hw_stopped
            && !(info->IER & UART_IER_THRI)) {
                info->IER |= UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
        return ret;
}
 
static int rs_write_room(struct tty_struct *tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_write_room"))
                return 0;
        return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
 
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 CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
 
static void rs_flush_buffer(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_buffer"))
                return;
        spin_lock_irqsave(&serial_lock, flags);
        info->xmit.head = info->xmit.tail = 0;
        spin_unlock_irqrestore(&serial_lock, flags);
        wake_up_interruptible(&tty->write_wait);
#ifdef SERIAL_HAVE_POLL_WAIT
        wake_up_interruptible(&tty->poll_wait);
#endif
        if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
            tty->ldisc.write_wakeup)
                (tty->ldisc.write_wakeup)(tty);
}
 
/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_send_char"))
                return;
 
        info->x_char = ch;
        if (ch) {
                /* Make sure transmit interrupts are on */
                info->IER |= UART_IER_THRI;
                serial_out(info, UART_IER, info->IER);
        }
}
 
/*
 * ------------------------------------------------------------
 * 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;
        unsigned long flags;
#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))
                rs_send_xchar(tty, STOP_CHAR(tty));
 
        if (tty->termios->c_cflag & CRTSCTS)
                info->MCR &= ~UART_MCR_RTS;
 
        spin_lock_irqsave(&serial_lock, flags);
        serial_out(info, UART_MCR, info->MCR);
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
static void rs_unthrottle(struct tty_struct * tty)
{
        struct async_struct *info = (struct async_struct *)tty->driver_data;
        unsigned long flags;
#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
                        rs_send_xchar(tty, START_CHAR(tty));
        }
        if (tty->termios->c_cflag & CRTSCTS)
                info->MCR |= UART_MCR_RTS;
        spin_lock_irqsave(&serial_lock, flags);
        serial_out(info, UART_MCR, info->MCR);
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
/*
 * ------------------------------------------------------------
 * rs_ioctl() and friends
 * ------------------------------------------------------------
 */
 
static int get_serial_info(struct async_struct * info,
                           struct serial_struct * retinfo)
{
        struct serial_struct tmp;
        struct serial_state *state = info->state;
 
        if (!retinfo)
                return -EFAULT;
        memset(&tmp, 0, sizeof(tmp));
        tmp.type = state->type;
        tmp.line = state->line;
        tmp.port = state->port;
        if (HIGH_BITS_OFFSET)
                tmp.port_high = state->port >> HIGH_BITS_OFFSET;
        else
                tmp.port_high = 0;
        tmp.irq = state->irq;
        tmp.flags = state->flags;
        tmp.xmit_fifo_size = state->xmit_fifo_size;
        tmp.baud_base = state->baud_base;
        tmp.close_delay = state->close_delay;
        tmp.closing_wait = state->closing_wait;
        tmp.custom_divisor = state->custom_divisor;
        tmp.hub6 = state->hub6;
        tmp.io_type = state->io_type;
        if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
                return -EFAULT;
        return 0;
}
 
static int set_serial_info(struct async_struct * info,
                           struct serial_struct * new_info)
{
        struct serial_struct new_serial;
        struct serial_state old_state, *state;
        unsigned int            i,change_irq,change_port;
        int                     retval = 0;
        unsigned long           new_port;
 
        if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
                return -EFAULT;
        state = info->state;
        old_state = *state;
 
        new_port = new_serial.port;
        if (HIGH_BITS_OFFSET)
                new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
 
        change_irq = new_serial.irq != state->irq;
        change_port = (new_port != ((int) state->port)) ||
                (new_serial.hub6 != state->hub6);
 
        if (!capable(CAP_SYS_ADMIN)) {
                if (change_irq || change_port ||
                    (new_serial.baud_base != state->baud_base) ||
                    (new_serial.type != state->type) ||
                    (new_serial.close_delay != state->close_delay) ||
                    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
                    ((new_serial.flags & ~ASYNC_USR_MASK) !=
                     (state->flags & ~ASYNC_USR_MASK)))
                        return -EPERM;
                state->flags = ((state->flags & ~ASYNC_USR_MASK) |
                               (new_serial.flags & ASYNC_USR_MASK));
                info->flags = ((info->flags & ~ASYNC_USR_MASK) |
                               (new_serial.flags & ASYNC_USR_MASK));
                state->custom_divisor = new_serial.custom_divisor;
                goto check_and_exit;
        }
 
        new_serial.irq = irq_cannonicalize(new_serial.irq);
 
        if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
            (new_serial.baud_base < 9600)|| (new_serial.type < PORT_UNKNOWN) ||
            (new_serial.type > PORT_MAX) || (new_serial.type == PORT_CIRRUS) ||
            (new_serial.type == PORT_STARTECH)) {
                return -EINVAL;
        }
 
        if ((new_serial.type != state->type) ||
            (new_serial.xmit_fifo_size <= 0))
                new_serial.xmit_fifo_size =
                        uart_config[new_serial.type].dfl_xmit_fifo_size;
 
        /* Make sure address is not already in use */
        if (new_serial.type) {
                for (i = 0 ; i < NR_PORTS; i++)
                        if ((state != &rs_table[i]) &&
                            (rs_table[i].port == new_port) &&
                            rs_table[i].type)
                                return -EADDRINUSE;
        }
 
        if ((change_port || change_irq) && (state->count > 1))
                return -EBUSY;
 
        /*
         * OK, past this point, all the error checking has been done.
         * At this point, we start making changes.....
         */
 
        state->baud_base = new_serial.baud_base;
        state->flags = ((state->flags & ~ASYNC_FLAGS) |
                        (new_serial.flags & ASYNC_FLAGS));
        info->flags = ((state->flags & ~ASYNC_INTERNAL_FLAGS) |
                       (info->flags & ASYNC_INTERNAL_FLAGS));
        state->custom_divisor = new_serial.custom_divisor;
        state->close_delay = new_serial.close_delay * HZ/100;
        state->closing_wait = new_serial.closing_wait * HZ/100;
        info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
        info->xmit_fifo_size = state->xmit_fifo_size =
                new_serial.xmit_fifo_size;
 
        if ((state->type != PORT_UNKNOWN) && state->port) {
                release_region(state->port,8);
        }
        state->type = new_serial.type;
        if (change_port || change_irq) {
                /*
                 * We need to shutdown the serial port at the old
                 * port/irq combination.
                 */
                shutdown(info);
                state->irq = new_serial.irq;
                info->port = state->port = new_port;
                info->hub6 = state->hub6 = new_serial.hub6;
                if (info->hub6)
                        info->io_type = state->io_type = SERIAL_IO_HUB6;
                else if (info->io_type == SERIAL_IO_HUB6)
                        info->io_type = state->io_type = SERIAL_IO_PORT;
        }
        if ((state->type != PORT_UNKNOWN) && state->port) {
                        request_region(state->port,8,"serial(set)");
        }
 
 
check_and_exit:
        if (!state->port || !state->type)
                return 0;
        if (info->flags & ASYNC_INITIALIZED) {
                if (((old_state.flags & ASYNC_SPD_MASK) !=
                     (state->flags & ASYNC_SPD_MASK)) ||
                    (old_state.custom_divisor != state->custom_divisor)) {
                        if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
                                info->tty->alt_speed = 57600;
                        if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
                                info->tty->alt_speed = 115200;
                        if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
                                info->tty->alt_speed = 230400;
                        if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
                                info->tty->alt_speed = 460800;
                        change_speed(info, 0);
                }
        } 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;
        unsigned long flags;
 
        spin_lock_irqsave(&serial_lock, flags);
        status = serial_in(info, UART_LSR);
        spin_unlock_irqrestore(&serial_lock, flags);
        result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
 
        /*
         * If we're about to load something into the transmit
         * register, we'll pretend the transmitter isn't empty to
         * avoid a race condition (depending on when the transmit
         * interrupt happens).
         */
        if (info->x_char ||
            ((CIRC_CNT(info->xmit.head, info->xmit.tail,
                       SERIAL_XMIT_SIZE) > 0) &&
             !info->tty->stopped && !info->tty->hw_stopped))
                result &= TIOCSER_TEMT;
 
        if (copy_to_user(value, &result, sizeof(int)))
                return -EFAULT;
        return 0;
}
 
 
static int get_modem_info(struct async_struct * info, unsigned int *value)
{
        unsigned char control, status;
        unsigned int result;
        unsigned long flags;
 
        control = info->MCR;
        spin_lock_irqsave(&serial_lock, flags);
        status = serial_in(info, UART_MSR);
        spin_unlock_irqrestore(&serial_lock, flags);
        result =  ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
                | ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
#ifdef TIOCM_OUT1
                | ((control & UART_MCR_OUT1) ? TIOCM_OUT1 : 0)
                | ((control & UART_MCR_OUT2) ? TIOCM_OUT2 : 0)
#endif
                | ((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);
 
        if (copy_to_user(value, &result, sizeof(int)))
                return -EFAULT;
        return 0;
}
 
static int set_modem_info(struct async_struct * info, unsigned int cmd,
                          unsigned int *value)
{
        unsigned int arg;
        unsigned long flags;
 
        if (copy_from_user(&arg, value, sizeof(int)))
                return -EFAULT;
 
        switch (cmd) {
        case TIOCMBIS:
                if (arg & TIOCM_RTS)
                        info->MCR |= UART_MCR_RTS;
                if (arg & TIOCM_DTR)
                        info->MCR |= UART_MCR_DTR;
#ifdef TIOCM_OUT1
                if (arg & TIOCM_OUT1)
                        info->MCR |= UART_MCR_OUT1;
                if (arg & TIOCM_OUT2)
                        info->MCR |= UART_MCR_OUT2;
#endif
                if (arg & TIOCM_LOOP)
                        info->MCR |= UART_MCR_LOOP;
                break;
        case TIOCMBIC:
                if (arg & TIOCM_RTS)
                        info->MCR &= ~UART_MCR_RTS;
                if (arg & TIOCM_DTR)
                        info->MCR &= ~UART_MCR_DTR;
#ifdef TIOCM_OUT1
                if (arg & TIOCM_OUT1)
                        info->MCR &= ~UART_MCR_OUT1;
                if (arg & TIOCM_OUT2)
                        info->MCR &= ~UART_MCR_OUT2;
#endif
                if (arg & TIOCM_LOOP)
                        info->MCR &= ~UART_MCR_LOOP;
                break;
        case TIOCMSET:
                info->MCR = ((info->MCR & ~(UART_MCR_RTS |
#ifdef TIOCM_OUT1
                                            UART_MCR_OUT1 |
                                            UART_MCR_OUT2 |
#endif
                                            UART_MCR_LOOP |
                                            UART_MCR_DTR))
                             | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
#ifdef TIOCM_OUT1
                             | ((arg & TIOCM_OUT1) ? UART_MCR_OUT1 : 0)
                             | ((arg & TIOCM_OUT2) ? UART_MCR_OUT2 : 0)
#endif
                             | ((arg & TIOCM_LOOP) ? UART_MCR_LOOP : 0)
                             | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
                break;
        default:
                return -EINVAL;
        }
        spin_lock_irqsave(&serial_lock, flags);
        info->MCR |= ALPHA_KLUDGE_MCR;          /* Don't ask */
        serial_out(info, UART_MCR, info->MCR);
        spin_unlock_irqrestore(&serial_lock, flags);
        return 0;
}
 
static int do_autoconfig(struct async_struct * info)
{
        int retval;
 
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
 
        if (info->state->count > 1)
                return -EBUSY;
 
        shutdown(info);
 
        autoconfig(info->state);
        retval = startup(info);
        if (retval)
                return retval;
        return 0;
}
 
/*
 * rs_break() --- routine which turns the break handling on or off
 */
static void rs_break(struct tty_struct *tty, int break_state)
{
        struct async_struct * info = (struct async_struct *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_break"))
                return;
 
        if (!CONFIGURED_SERIAL_PORT(info))
                return;
        spin_lock_irqsave(&serial_lock, flags);
        if (break_state == -1)
                info->LCR |= UART_LCR_SBC;
        else
                info->LCR &= ~UART_LCR_SBC;
        serial_out(info, UART_LCR, info->LCR);
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
 
static int rs_ioctl(struct tty_struct *tty, struct file * file,
                    unsigned int cmd, unsigned long arg)
{
        struct async_struct * info = (struct async_struct *)tty->driver_data;
        struct async_icount cprev, cnow;        /* kernel counter temps */
        struct serial_icounter_struct icount;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
                return -ENODEV;
 
        if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
            (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
            (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
                if (tty->flags & (1 << TTY_IO_ERROR))
                    return -EIO;
        }
 
        switch (cmd) {
                case TIOCMGET:
                        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:
                        return get_serial_info(info,
                                               (struct serial_struct *) arg);
                case TIOCSSERIAL:
                        return set_serial_info(info,
                                               (struct serial_struct *) arg);
                case TIOCSERCONFIG:
                        return do_autoconfig(info);
 
                case TIOCSERGETLSR: /* Get line status register */
                        return get_lsr_info(info, (unsigned int *) arg);
 
                case TIOCSERGSTRUCT:
                        if (copy_to_user((struct async_struct *) arg,
                                         info, sizeof(struct async_struct)))
                                return -EFAULT;
                        return 0;
 
 
                /*
                 * 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:
                        spin_lock_irqsave(&serial_lock, flags);
                        /* note the counters on entry */
                        cprev = info->state->icount;
                        spin_unlock_irqrestore(&serial_lock, flags);
                        /* Force modem status interrupts on */
                        info->IER |= UART_IER_MSI;
                        serial_out(info, UART_IER, info->IER);
                        while (1) {
                                interruptible_sleep_on(&info->delta_msr_wait);
                                /* see if a signal did it */
                                if (signal_pending(current))
                                        return -ERESTARTSYS;
                                spin_lock_irqsave(&serial_lock, flags);
                                cnow = info->state->icount; /* atomic copy */
                                spin_unlock_irqrestore(&serial_lock, flags);
                                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:
                        spin_lock_irqsave(&serial_lock, flags);
                        cnow = info->state->icount;
                        spin_unlock_irqrestore(&serial_lock, flags);
                        icount.cts = cnow.cts;
                        icount.dsr = cnow.dsr;
                        icount.rng = cnow.rng;
                        icount.dcd = cnow.dcd;
                        icount.rx = cnow.rx;
                        icount.tx = cnow.tx;
                        icount.frame = cnow.frame;
                        icount.overrun = cnow.overrun;
                        icount.parity = cnow.parity;
                        icount.brk = cnow.brk;
                        icount.buf_overrun = cnow.buf_overrun;
 
                        if (copy_to_user((void *)arg, &icount, sizeof(icount)))
                                return -EFAULT;
                        return 0;
                case TIOCSERGWILD:
                case TIOCSERSWILD:
                        /* "setserial -W" is called in Debian boot */
                        printk ("TIOCSER?WILD ioctl obsolete, ignored.\n");
                        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;
        unsigned long flags;
        unsigned int cflag = tty->termios->c_cflag;
 
        if (   (cflag == old_termios->c_cflag)
            && (   RELEVANT_IFLAG(tty->termios->c_iflag)
                == RELEVANT_IFLAG(old_termios->c_iflag)))
          return;
 
        change_speed(info, old_termios);
 
        /* Handle transition to B0 status */
        if ((old_termios->c_cflag & CBAUD) &&
            !(cflag & CBAUD)) {
                info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
                spin_lock_irqsave(&serial_lock, flags);
                serial_out(info, UART_MCR, info->MCR);
                spin_unlock_irqrestore(&serial_lock, flags);
        }
 
        /* Handle transition away from B0 status */
        if (!(old_termios->c_cflag & CBAUD) &&
            (cflag & CBAUD)) {
                info->MCR |= UART_MCR_DTR;
                if (!(tty->termios->c_cflag & CRTSCTS) ||
                    !test_bit(TTY_THROTTLED, &tty->flags)) {
                        info->MCR |= UART_MCR_RTS;
                }
                spin_lock_irqsave(&serial_lock, flags);
                serial_out(info, UART_MCR, info->MCR);
                spin_unlock_irqrestore(&serial_lock, flags);
        }
 
        /* Handle turning off CRTSCTS */
        if ((old_termios->c_cflag & CRTSCTS) &&
            !(tty->termios->c_cflag & CRTSCTS)) {
                tty->hw_stopped = 0;
                rs_start(tty);
        }
}
 
/*
 * ------------------------------------------------------------
 * 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;
        struct serial_state *state;
        unsigned long flags;
 
        if (!info || serial_paranoia_check(info, tty->device, "rs_close"))
                return;
 
        state = info->state;
 
        spin_lock_irqsave(&serial_lock, flags);
 
        if (tty_hung_up_p(filp)) {
                DBG_CNT("before DEC-hung");
                MOD_DEC_USE_COUNT;
                spin_unlock_irqrestore(&serial_lock, flags);
                return;
        }
 
#ifdef SERIAL_DEBUG_OPEN
        printk("rs_close ttys%d, count = %d\n", info->line, state->count);
#endif
        if ((tty->count == 1) && (state->count != 1)) {
                /*
                 * Uh, oh.  tty->count is 1, which means that the tty
                 * structure will be freed.  state->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, "
                       "state->count is %d\n", state->count);
                state->count = 1;
        }
        if (--state->count < 0) {
                printk("rs_close: bad serial port count for ttys%d: %d\n",
                       info->line, state->count);
                state->count = 0;
        }
        if (state->count) {
                DBG_CNT("before DEC-2");
                MOD_DEC_USE_COUNT;
                spin_unlock_irqrestore(&serial_lock, flags);
                return;
        }
        info->flags |= ASYNC_CLOSING;
        spin_unlock_irqrestore(&serial_lock, flags);
        /*
         * Save the termios structure, since this port may have
         * separate termios for callout and dialin.
         */
        if (info->flags & ASYNC_NORMAL_ACTIVE)
                info->state->normal_termios = *tty->termios;
        if (info->flags & ASYNC_CALLOUT_ACTIVE)
                info->state->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!
                 */
                rs_wait_until_sent(tty, info->timeout);
        }
        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) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        schedule_timeout(info->close_delay);
                }
                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;
}
 
/*
 * rs_wait_until_sent() --- wait until the transmitter is empty
 */
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
        struct async_struct * info = (struct async_struct *)tty->driver_data;
        unsigned long orig_jiffies, char_time;
        int lsr;
 
        if (serial_paranoia_check(info, tty->device, "rs_wait_until_sent"))
                return;
 
        if (info->state->type == PORT_UNKNOWN)
                return;
 
        if (info->xmit_fifo_size == 0)
                return; /* Just in case.... */
 
        orig_jiffies = jiffies;
        /*
         * Set the check interval to be 1/5 of the estimated time to
         * send a single character, and make it at least 1.  The check
         * interval should also be less than the timeout.
         *
         * Note: we have to use pretty tight timings here to satisfy
         * the NIST-PCTS.
         */
        char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
        char_time = char_time / 5;
        if (char_time == 0)
                char_time = 1;
        if (timeout && timeout < char_time)
                char_time = timeout;
        /*
         * If the transmitter hasn't cleared in twice the approximate
         * amount of time to send the entire FIFO, it probably won't
         * ever clear.  This assumes the UART isn't doing flow
         * control, which is currently the case.  Hence, if it ever
         * takes longer than info->timeout, this is probably due to a
         * UART bug of some kind.  So, we clamp the timeout parameter at
         * 2*info->timeout.
         */
        if (!timeout || timeout > 2*info->timeout)
                timeout = 2*info->timeout;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
        printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
        printk("jiff=%lu...", jiffies);
#endif
        while (!((lsr = serial_inp(info, UART_LSR)) & UART_LSR_TEMT)) {
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
                printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
#endif
                set_current_state(TASK_INTERRUPTIBLE);
                schedule_timeout(char_time);
                if (signal_pending(current))
                        break;
                if (timeout && time_after(jiffies, orig_jiffies + timeout))
                        break;
        }
        set_current_state(TASK_RUNNING);
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
        printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
#endif
}
 
/*
 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
static void rs_hangup(struct tty_struct *tty)
{
        struct async_struct * info = (struct async_struct *)tty->driver_data;
        struct serial_state *state = info->state;
 
        if (serial_paranoia_check(info, tty->device, "rs_hangup"))
                return;
 
        state = info->state;
 
        rs_flush_buffer(tty);
        if (info->flags & ASYNC_CLOSING)
                return;
        shutdown(info);
        info->event = 0;
        state->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)
{
        DECLARE_WAITQUEUE(wait, current);
        struct serial_state *state = info->state;
        int             retval;
        int             do_clocal = 0, extra_count = 0;
        unsigned long   flags;
 
        /*
         * 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
                return ((info->flags & ASYNC_HUP_NOTIFY) ?
                        -EAGAIN : -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 (state->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, state->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",
               state->line, state->count);
#endif
        spin_lock_irqsave(&serial_lock, flags);
        if (!tty_hung_up_p(filp)) {
                extra_count = 1;
                state->count--;
        }
        spin_unlock_irqrestore(&serial_lock, flags);
        info->blocked_open++;
        while (1) {
                spin_lock_irqsave(&serial_lock, flags);
                if (!(info->flags & ASYNC_CALLOUT_ACTIVE) &&
                    (tty->termios->c_cflag & CBAUD))
                        serial_out(info, UART_MCR,
                                   serial_inp(info, UART_MCR) |
                                   (UART_MCR_DTR | UART_MCR_RTS));
                spin_unlock_irqrestore(&serial_lock, flags);
                set_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 (signal_pending(current)) {
                        retval = -ERESTARTSYS;
                        break;
                }
#ifdef SERIAL_DEBUG_OPEN
                printk("block_til_ready blocking: ttys%d, count = %d\n",
                       info->line, state->count);
#endif
                schedule();
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&info->open_wait, &wait);
        if (extra_count)
                state->count++;
        info->blocked_open--;
#ifdef SERIAL_DEBUG_OPEN
        printk("block_til_ready after blocking: ttys%d, count = %d\n",
               info->line, state->count);
#endif
        if (retval)
                return retval;
        info->flags |= ASYNC_NORMAL_ACTIVE;
        return 0;
}
 
static int get_async_struct(int line, struct async_struct **ret_info)
{
        struct async_struct *info;
        struct serial_state *sstate;
 
        sstate = rs_table + line;
        sstate->count++;
        if (sstate->info) {
                *ret_info = sstate->info;
                return 0;
        }
        info = kmalloc(sizeof(struct async_struct), GFP_KERNEL);
        if (!info) {
                sstate->count--;
                return -ENOMEM;
        }
        memset(info, 0, sizeof(struct async_struct));
        init_waitqueue_head(&info->open_wait);
        init_waitqueue_head(&info->close_wait);
        init_waitqueue_head(&info->delta_msr_wait);
        info->magic = SERIAL_MAGIC;
        info->port = sstate->port;
        info->flags = sstate->flags;
        info->io_type = sstate->io_type;
        info->iomem_base = sstate->iomem_base;
        info->iomem_reg_shift = sstate->iomem_reg_shift;
        info->xmit_fifo_size = sstate->xmit_fifo_size;
        info->line = line;
        info->tqueue.routine = do_softint;
        info->tqueue.data = info;
        info->state = sstate;
        if (sstate->info) {
                kfree(info);
                *ret_info = sstate->info;
                return 0;
        }
        *ret_info = sstate->info = info;
        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.
 */
static int rs_open(struct tty_struct *tty, struct file * filp)
{
        struct async_struct     *info;
        int                     retval, line;
        unsigned long           page;
 
        MOD_INC_USE_COUNT;
        line = MINOR(tty->device) - tty->driver.minor_start;
        if ((line < 0) || (line >= NR_PORTS)) {
                MOD_DEC_USE_COUNT;
                return -ENODEV;
        }
        retval = get_async_struct(line, &info);
        if (retval) {
                MOD_DEC_USE_COUNT;
                return retval;
        }
        tty->driver_data = info;
        info->tty = tty;
        if (serial_paranoia_check(info, tty->device, "rs_open")) {
                MOD_DEC_USE_COUNT;
                return -ENODEV;
        }
 
#ifdef SERIAL_DEBUG_OPEN
        printk("rs_open %s%d, count = %d\n", tty->driver.name, info->line,
               info->state->count);
#endif
        info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 
        if (!tmp_buf) {
                page = get_zeroed_page(GFP_KERNEL);
                if (!page) {
                        MOD_DEC_USE_COUNT;
                        return -ENOMEM;
                }
                if (tmp_buf)
                        free_page(page);
                else
                        tmp_buf = (unsigned char *) page;
        }
 
        /*
         * If the port is the middle of closing, bail out now
         */
        if (tty_hung_up_p(filp) ||
            (info->flags & ASYNC_CLOSING)) {
                if (info->flags & ASYNC_CLOSING)
                        interruptible_sleep_on(&info->close_wait);
                MOD_DEC_USE_COUNT;
#ifdef SERIAL_DO_RESTART
                return ((info->flags & ASYNC_HUP_NOTIFY) ?
                        -EAGAIN : -ERESTARTSYS);
#else
                return -EAGAIN;
#endif
        }
 
        /*
         * Start up serial port
         */
        retval = startup(info);
        if (retval) {
                MOD_DEC_USE_COUNT;
                return retval;
        }
 
        retval = block_til_ready(tty, filp, info);
        if (retval) {
#ifdef SERIAL_DEBUG_OPEN
                printk("rs_open returning after block_til_ready with %d\n",
                       retval);
#endif
                MOD_DEC_USE_COUNT;
                return retval;
        }
 
        if ((info->state->count == 1) &&
            (info->flags & ASYNC_SPLIT_TERMIOS)) {
                if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
                        *tty->termios = info->state->normal_termios;
                else
                        *tty->termios = info->state->callout_termios;
                change_speed(info, 0);
        }
#ifdef CONFIG_AU1X00_SERIAL_CONSOLE
        if (sercons.cflag && sercons.index == line) {
                tty->termios->c_cflag = sercons.cflag;
                sercons.cflag = 0;
                change_speed(info, 0);
        }
#endif
        info->session = current->session;
        info->pgrp = current->pgrp;
 
#ifdef SERIAL_DEBUG_OPEN
        printk("rs_open ttys%d successful...", info->line);
#endif
        return 0;
}
 
/*
 * /proc fs routines....
 */
 
static inline int line_info(char *buf, struct serial_state *state)
{
        struct async_struct *info = state->info, scr_info;
        char    stat_buf[30], control, status;
        int     ret;
        unsigned long flags;
 
        ret = sprintf(buf, "%d: uart:%s port:%lX irq:%d",
                      state->line, uart_config[state->type].name,
                      state->port, state->irq);
 
        if (!state->port || (state->type == PORT_UNKNOWN)) {
                ret += sprintf(buf+ret, "\n");
                return ret;
        }
 
        /*
         * Figure out the current RS-232 lines
         */
        if (!info) {
                info = &scr_info;       /* This is just for serial_{in,out} */
 
                info->magic = SERIAL_MAGIC;
                info->port = state->port;
                info->flags = state->flags;
                info->quot = 0;
                info->tty = 0;
        }
        spin_lock_irqsave(&serial_lock, flags);
        status = serial_in(info, UART_MSR);
        control = info != &scr_info ? info->MCR : serial_in(info, UART_MCR);
        spin_unlock_irqrestore(&serial_lock, flags);
 
        stat_buf[0] = 0;
        stat_buf[1] = 0;
        if (control & UART_MCR_RTS)
                strcat(stat_buf, "|RTS");
        if (status & UART_MSR_CTS)
                strcat(stat_buf, "|CTS");
        if (control & UART_MCR_DTR)
                strcat(stat_buf, "|DTR");
        if (status & UART_MSR_DSR)
                strcat(stat_buf, "|DSR");
        if (status & UART_MSR_DCD)
                strcat(stat_buf, "|CD");
        if (status & UART_MSR_RI)
                strcat(stat_buf, "|RI");
 
        if (info->quot) {
                ret += sprintf(buf+ret, " baud:%d",
                               state->baud_base / info->quot);
        }
 
        ret += sprintf(buf+ret, " tx:%d rx:%d",
                      state->icount.tx, state->icount.rx);
 
        if (state->icount.frame)
                ret += sprintf(buf+ret, " fe:%d", state->icount.frame);
 
        if (state->icount.parity)
                ret += sprintf(buf+ret, " pe:%d", state->icount.parity);
 
        if (state->icount.brk)
                ret += sprintf(buf+ret, " brk:%d", state->icount.brk);
 
        if (state->icount.overrun)
                ret += sprintf(buf+ret, " oe:%d", state->icount.overrun);
 
        /*
         * Last thing is the RS-232 status lines
         */
        ret += sprintf(buf+ret, " %s\n", stat_buf+1);
        return ret;
}
 
int rs_read_proc(char *page, char **start, off_t off, int count,
                 int *eof, void *data)
{
        int i, len = 0, l;
        off_t   begin = 0;
 
        len += sprintf(page, "serinfo:1.0 driver:%s%s revision:%s\n",
                       serial_version, LOCAL_VERSTRING, serial_revdate);
        for (i = 0; i < NR_PORTS && len < 4000; i++) {
                l = line_info(page + len, &rs_table[i]);
                len += l;
                if (len+begin > off+count)
                        goto done;
                if (len+begin < off) {
                        begin += len;
                        len = 0;
                }
        }
        *eof = 1;
done:
        if (off >= len+begin)
                return 0;
        *start = page + (off-begin);
        return ((count < begin+len-off) ? count : begin+len-off);
}
 
/*
 * ---------------------------------------------------------------------
 * 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 char serial_options[] __initdata =
       " no serial options enabled\n";
#undef SERIAL_OPT
 
static _INLINE_ void show_serial_version(void)
{
        printk(KERN_INFO "%s version %s%s (%s) with%s", serial_name,
               serial_version, LOCAL_VERSTRING, serial_revdate,
               serial_options);
}
 
 
/*
 * 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 serial_state * state)
{
        struct async_struct *info, scr_info;
        unsigned long flags;
 
 
#ifdef SERIAL_DEBUG_AUTOCONF
        printk("Testing ttyS%d (0x%04lx, 0x%04x)...\n", state->line,
               state->port, (unsigned) state->iomem_base);
#endif
 
        if (!CONFIGURED_SERIAL_PORT(state))
                return;
 
        if (au_readl(UART_MOD_CNTRL + state->port) != 0x3) {
                au_writel(3, UART_MOD_CNTRL + state->port);
                au_sync_delay(10);
        }
 
        state->type = PORT_16550;
        info = &scr_info;       /* This is just for serial_{in,out} */
 
        info->magic = SERIAL_MAGIC;
        info->state = state;
        info->port = state->port;
        info->flags = state->flags;
        info->io_type = state->io_type;
        info->iomem_base = state->iomem_base;
        info->iomem_reg_shift = state->iomem_reg_shift;
 
 
        spin_lock_irqsave(&serial_lock, flags);
        state->xmit_fifo_size = uart_config[state->type].dfl_xmit_fifo_size;
 
        if (info->port) {
                        request_region(info->port,8,"serial(auto)");
        }
 
        /*
         * Reset the UART.
         */
        serial_outp(info, UART_FCR, (UART_FCR_ENABLE_FIFO |
                                     UART_FCR_CLEAR_RCVR |
                                     UART_FCR_CLEAR_XMIT));
        serial_outp(info, UART_FCR, 0);
        (void)serial_in(info, UART_RX);
        serial_outp(info, UART_IER, 0);
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
int register_serial(struct serial_struct *req);
void unregister_serial(int line);
 
/*
 * The serial driver boot-time initialization code!
 */
static int __init rs_init(void)
{
        int i;
        struct serial_state * state;
 
        init_bh(SERIAL_BH, do_serial_bh);
        init_timer(&serial_timer);
        serial_timer.function = rs_timer;
        mod_timer(&serial_timer, jiffies + RS_STROBE_TIME);
 
        for (i = 0; i < NR_IRQS; i++) {
                IRQ_ports[i] = 0;
                IRQ_timeout[i] = 0;
        }
#ifdef CONFIG_AU1X00_SERIAL_CONSOLE
        /*
         *      The interrupt of the serial console port
         *      can't be shared.
         */
        if (sercons.flags & CON_CONSDEV) {
                for(i = 0; i < NR_PORTS; i++)
                        if (i != sercons.index &&
                            rs_table[i].irq == rs_table[sercons.index].irq)
                                rs_table[i].irq = 0;
        }
#endif
        show_serial_version();
 
        /* Initialize the tty_driver structure */
 
        memset(&serial_driver, 0, sizeof(struct tty_driver));
        serial_driver.magic = TTY_DRIVER_MAGIC;
        serial_driver.driver_name = "serial";
#if (LINUX_VERSION_CODE > 0x2032D && defined(CONFIG_DEVFS_FS))
        serial_driver.name = "tts/%d";
#else
        serial_driver.name = "ttyS";
#endif
        serial_driver.major = TTY_MAJOR;
        serial_driver.minor_start = 64 + SERIAL_DEV_OFFSET;
        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 | TTY_DRIVER_NO_DEVFS;
        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;
        serial_driver.break_ctl = rs_break;
        serial_driver.send_xchar = rs_send_xchar;
        serial_driver.wait_until_sent = rs_wait_until_sent;
        serial_driver.read_proc = rs_read_proc;
 
        /*
         * The callout device is just like normal device except for
         * major number and the subtype code.
         */
        callout_driver = serial_driver;
#if (LINUX_VERSION_CODE > 0x2032D && defined(CONFIG_DEVFS_FS))
        callout_driver.name = "cua/%d";
#else
        callout_driver.name = "cua";
#endif
        callout_driver.major = TTYAUX_MAJOR;
        callout_driver.subtype = SERIAL_TYPE_CALLOUT;
        callout_driver.read_proc = 0;
        callout_driver.proc_entry = 0;
 
        if (tty_register_driver(&serial_driver))
                panic("Couldn't register serial driver");
        if (tty_register_driver(&callout_driver))
                panic("Couldn't register callout driver");
 
        for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {
                state->baud_base = get_au1x00_uart_baud_base();
                state->magic = SSTATE_MAGIC;
                state->line = i;
                state->type = PORT_UNKNOWN;
                state->custom_divisor = 0;
                state->close_delay = 5*HZ/10;
                state->closing_wait = 30*HZ;
                state->callout_termios = callout_driver.init_termios;
                state->normal_termios = serial_driver.init_termios;
                state->icount.cts = state->icount.dsr =
                        state->icount.rng = state->icount.dcd = 0;
                state->icount.rx = state->icount.tx = 0;
                state->icount.frame = state->icount.parity = 0;
                state->icount.overrun = state->icount.brk = 0;
                state->irq = irq_cannonicalize(state->irq);
                if (state->hub6)
                        state->io_type = SERIAL_IO_HUB6;
                if (state->port && check_region(state->port,8)) {
                        continue;
                }
 
                if (state->flags & ASYNC_BOOT_AUTOCONF) {
                        autoconfig(state);
                }
        }
        for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {
                if (state->type == PORT_UNKNOWN) {
                        continue;
                }
                printk(KERN_INFO "ttyS%02d%s at 0x%04lx (irq = %d) is a %s\n",
                       state->line + SERIAL_DEV_OFFSET,
                       (state->flags & ASYNC_FOURPORT) ? " FourPort" : "",
                       state->port, state->irq,
                       uart_config[state->type].name);
                tty_register_devfs(&serial_driver, 0,
                                   serial_driver.minor_start + state->line);
                tty_register_devfs(&callout_driver, 0,
                                   callout_driver.minor_start + state->line);
        }
        return 0;
}
 
/*
 * register_serial and unregister_serial allows for 16x50 serial ports to be
 * configured at run-time, to support PCMCIA modems.
 */
 
/**
 *      register_serial - configure a 16x50 serial port at runtime
 *      @req: request structure
 *
 *      Configure the serial port specified by the request. If the
 *      port exists and is in use an error is returned. If the port
 *      is not currently in the table it is added.
 *
 *      The port is then probed and if neccessary the IRQ is autodetected
 *      If this fails an error is returned.
 *
 *      On success the port is ready to use and the line number is returned.
 */
 
int register_serial(struct serial_struct *req)
{
        int i;
        unsigned long flags;
        struct serial_state *state;
        struct async_struct *info;
        unsigned long port;
 
        port = req->port;
        if (HIGH_BITS_OFFSET)
                port += (unsigned long) req->port_high << HIGH_BITS_OFFSET;
 
        spin_lock_irqsave(&serial_lock, flags);
        for (i = 0; i < NR_PORTS; i++) {
                if ((rs_table[i].port == port) &&
                    (rs_table[i].iomem_base == req->iomem_base))
                        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) {
                spin_unlock_irqrestore(&serial_lock, flags);
                return -1;
        }
        state = &rs_table[i];
        if (rs_table[i].count) {
                spin_unlock_irqrestore(&serial_lock, flags);
                printk("Couldn't configure serial #%d (port=%ld,irq=%d): "
                       "device already open\n", i, port, req->irq);
                return -1;
        }
        state->irq = req->irq;
        state->port = port;
        state->flags = req->flags;
        state->io_type = req->io_type;
        state->iomem_base = req->iomem_base;
        state->iomem_reg_shift = req->iomem_reg_shift;
        if (req->baud_base)
                state->baud_base = req->baud_base;
        if ((info = state->info) != NULL) {
                info->port = port;
                info->flags = req->flags;
                info->io_type = req->io_type;
                info->iomem_base = req->iomem_base;
                info->iomem_reg_shift = req->iomem_reg_shift;
        }
        autoconfig(state);
        if (state->type == PORT_UNKNOWN) {
                spin_unlock_irqrestore(&serial_lock, flags);
                printk("register_serial(): autoconfig failed\n");
                return -1;
        }
        spin_unlock_irqrestore(&serial_lock, flags);
 
       printk(KERN_INFO "ttyS%02d at %s 0x%04lx (irq = %d) is a %s\n",
              state->line + SERIAL_DEV_OFFSET,
              state->iomem_base ? "iomem" : "port",
              state->iomem_base ? (unsigned long)state->iomem_base :
              state->port, state->irq, uart_config[state->type].name);
        tty_register_devfs(&serial_driver, 0,
                           serial_driver.minor_start + state->line);
        tty_register_devfs(&callout_driver, 0,
                           callout_driver.minor_start + state->line);
        return state->line + SERIAL_DEV_OFFSET;
}
 
/**
 *      unregister_serial - deconfigure a 16x50 serial port
 *      @line: line to deconfigure
 *
 *      The port specified is deconfigured and its resources are freed. Any
 *      user of the port is disconnected as if carrier was dropped. Line is
 *      the port number returned by register_serial().
 */
 
void unregister_serial(int line)
{
        unsigned long flags;
        struct serial_state *state = &rs_table[line];
 
        spin_lock_irqsave(&serial_lock, flags);
        if (state->info && state->info->tty)
                tty_hangup(state->info->tty);
        state->type = PORT_UNKNOWN;
        printk(KERN_INFO "tty%02d unloaded\n", state->line);
        /* These will be hidden, because they are devices that will no longer
         * be available to the system. (ie, PCMCIA modems, once ejected)
         */
        tty_unregister_devfs(&serial_driver,
                             serial_driver.minor_start + state->line);
        tty_unregister_devfs(&callout_driver,
                             callout_driver.minor_start + state->line);
        spin_unlock_irqrestore(&serial_lock, flags);
}
 
static void __exit rs_fini(void)
{
        unsigned long flags;
        int e1, e2;
        int i;
        struct async_struct *info;
 
        /* printk("Unloading %s: version %s\n", serial_name, serial_version); */
        del_timer_sync(&serial_timer);
        spin_lock_irqsave(&serial_lock, flags);
        remove_bh(SERIAL_BH);
        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);
        spin_unlock_irqrestore(&serial_lock, flags);
 
        for (i = 0; i < NR_PORTS; i++) {
                if ((info = rs_table[i].info)) {
                        rs_table[i].info = NULL;
                        kfree(info);
                }
                if ((rs_table[i].type != PORT_UNKNOWN) && rs_table[i].port) {
                                release_region(rs_table[i].port, 8);
                }
        }
        if (tmp_buf) {
                unsigned long pg = (unsigned long) tmp_buf;
                tmp_buf = NULL;
                free_page(pg);
        }
}
 
module_init(rs_init);
module_exit(rs_fini);
MODULE_DESCRIPTION("Au1x00 serial driver");
 
 
/*
 * ------------------------------------------------------------
 * Serial console driver
 * ------------------------------------------------------------
 */
#ifdef CONFIG_AU1X00_SERIAL_CONSOLE
 
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
 
static struct async_struct async_sercons;
 
/*
 *      Wait for transmitter & holding register to empty
 */
static inline void wait_for_xmitr(struct async_struct *info)
{
        unsigned int status, tmout = 0xffffff;
 
        do {
                status = serial_in(info, UART_LSR);
 
                if (status & UART_LSR_BI)
                        lsr_break_flag = UART_LSR_BI;
 
                if (--tmout == 0)
                        break;
        } while((status & BOTH_EMPTY) != BOTH_EMPTY);
}
 
 
/*
 *      Print a string to the serial port trying not to disturb
 *      any possible real use of the port...
 *
 *      The console_lock must be held when we get here.
 */
static void serial_console_write(struct console *co, const char *s,
                                unsigned count)
{
        static struct async_struct *info = &async_sercons;
        int ier;
        unsigned i;
 
        /*
         *      First save the IER then disable the interrupts
         */
        ier = serial_in(info, UART_IER);
        serial_out(info, UART_IER, 0x00);
 
        /*
         *      Now, do each character
         */
        for (i = 0; i < count; i++, s++) {
                wait_for_xmitr(info);
 
                /*
                 *      Send the character out.
                 *      If a LF, also do CR...
                 */
                serial_out(info, UART_TX, *s);
                if (*s == 10) {
                        wait_for_xmitr(info);
                        serial_out(info, UART_TX, 13);
                }
        }
 
        /*
         *      Finally, Wait for transmitter & holding register to empty
         *      and restore the IER
         */
        wait_for_xmitr(info);
        serial_out(info, UART_IER, ier);
}
 
/*
 *      Receive character from the serial port
 */
static int serial_console_wait_key(struct console *co)
{
        static struct async_struct *info;
        int ier, c;
 
        info = &async_sercons;
 
        /*
         *      First save the IER then disable the interrupts so
         *      that the real driver for the port does not get the
         *      character.
         */
        ier = serial_in(info, UART_IER);
        serial_out(info, UART_IER, 0x00);
 
        while ((serial_in(info, UART_LSR) & UART_LSR_DR) == 0);
        c = serial_in(info, UART_RX);
 
        /*
         *      Restore the interrupts
         */
        serial_out(info, UART_IER, ier);
 
        return c;
}
 
static kdev_t serial_console_device(struct console *c)
{
        return MKDEV(TTY_MAJOR, 64 + c->index);
}
 
/*
 *      Setup initial baud/bits/parity. We do two things here:
 *      - construct a cflag setting for the first rs_open()
 *      - initialize the serial port
 *      Return non-zero if we didn't find a serial port.
 */
static int __init serial_console_setup(struct console *co, char *options)
{
        static struct async_struct *info;
        struct serial_state *state;
        unsigned cval;
        int     baud = 9600;
        int     bits = 8;
        int     parity = 'n';
        int     cflag = CREAD | HUPCL | CLOCAL;
        int     quot = 0;
        char    *s;
 
        if (options) {
                baud = simple_strtoul(options, NULL, 10);
                s = options;
                while(*s >= '0' && *s <= '9')
                        s++;
                if (*s) parity = *s++;
                if (*s) bits   = *s - '0';
        }
 
        /*
         *      Now construct a cflag setting.
         */
        switch(baud) {
                case 1200:
                        cflag |= B1200;
                        break;
                case 2400:
                        cflag |= B2400;
                        break;
                case 4800:
                        cflag |= B4800;
                        break;
                case 19200:
                        cflag |= B19200;
                        break;
                case 38400:
                        cflag |= B38400;
                        break;
                case 57600:
                        cflag |= B57600;
                        break;
                case 115200:
                        cflag |= B115200;
                        break;
                case 9600:
                default:
                        cflag |= B9600;
                        break;
        }
        switch(bits) {
                case 7:
                        cflag |= CS7;
                        break;
                default:
                case 8:
                        cflag |= CS8;
                        break;
        }
        switch(parity) {
                case 'o': case 'O':
                        cflag |= PARODD;
                        break;
                case 'e': case 'E':
                        cflag |= PARENB;
                        break;
        }
        co->cflag = cflag;
 
        /*
         *      Divisor, bytesize and parity
         */
        state = rs_table + co->index;
        info = &async_sercons;
        info->magic = SERIAL_MAGIC;
        info->state = state;
        info->port = state->port;
        info->flags = state->flags;
        info->io_type = state->io_type;
        info->iomem_base = state->iomem_base;
        info->iomem_reg_shift = state->iomem_reg_shift;
        state->baud_base = get_au1x00_uart_baud_base();
        quot = state->baud_base / baud;
 
        cval = cflag & (CSIZE | CSTOPB);
        cval >>= 4;
        if (cflag & PARENB)
                cval |= UART_LCR_PARITY;
        if (!(cflag & PARODD))
                cval |= UART_LCR_EPAR;
 
        /*
         *      Disable UART interrupts, set DTR and RTS high
         *      and set speed.
         */
        serial_out(info, UART_CLK, quot & 0xffff);
        serial_out(info, UART_IER, 0);
        serial_out(info, UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
 
        /*
         *      If we read 0xff from the LSR, there is no UART here.
         */
        if (serial_in(info, UART_LSR) == 0xff)
                return -1;
 
        return 0;
}
 
static struct console sercons = {
        .name           = "ttyS",
        .write          = serial_console_write,
        .device         = serial_console_device,
        .setup          = serial_console_setup,
        .flags          = CON_PRINTBUFFER,
        .index          = -1,
};
 
/*
 *      Register console.
 */
void __init au1x00_serial_console_init(void)
{
        register_console(&sercons);
}
#endif
 
/*
  Local variables:
  compile-command: "gcc -D__KERNEL__ -I../../include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -fno-strict-aliasing -pipe -fno-strength-reduce -march=i586 -DMODULE -DMODVERSIONS -include ../../include/linux/modversions.h   -DEXPORT_SYMTAB -c serial.c"
  End:
*/
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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [au1x00-serial.c] - Blame information for rev 1774

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`*`
3			`* BRIEF MODULE DESCRIPTION`
4			`* Au1x00 serial port driver.`
5			`*`
6			`* Copyright 2001 MontaVista Software Inc.`
7			`* Author: MontaVista Software, Inc.`
8			`* ppopov@mvista.com or source@mvista.com`
9			`*`
10			`* Derived almost entirely from drivers/char/serial.c:`
11			`*`
12			`* Copyright (C) 1991, 1992 Linus Torvalds`
13			`* Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,`
14			`* 1998, 1999 Theodore Ts'o`
15			`*`
16			`* This program is free software; you can redistribute it and/or modify it`
17			`* under the terms of the GNU General Public License as published by the`
18			`* Free Software Foundation; either version 2 of the License, or (at your`
19			`* option) any later version.`
20			`*`
21			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22			`* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF`
23			`* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN`
24			`* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,`
25			`* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT`
26			`* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF`
27			`* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON`
28			`* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT`
29			`* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF`
30			`* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.`
31			`*`
32			`* You should have received a copy of the GNU General Public License along`
33			`* with this program; if not, write to the Free Software Foundation, Inc.,`
34			`* 675 Mass Ave, Cambridge, MA 02139, USA.`
35			`*/`
36
37			`static char *serial_version = "1.01";`
38			`static char *serial_revdate = "2001-02-08";`
39
40