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simserial.c

/*
 * Simulated Serial Driver (fake serial)
 *
 * This driver is mostly used for bringup purposes and will go away.
 * It has a strong dependency on the system console. All outputs
 * are rerouted to the same facility as the one used by printk which, in our
 * case means sys_sim.c console (goes via the simulator). The code hereafter
 * is completely leveraged from the serial.c driver.
 *
 * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
 *    Stephane Eranian <eranian@hpl.hp.com>
 *    David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * 02/04/00 D. Mosberger      Merged in serial.c bug fixes in rs_close().
 * 02/25/00 D. Mosberger      Synced up with 2.3.99pre-5 version of serial.c.
 * 07/30/02 D. Mosberger      Replace sti()/cli() with explicit spinlocks & local irq masking
 */

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/capability.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/sysrq.h>

#include <asm/irq.h>
#include <asm/hw_irq.h>
#include <asm/uaccess.h>

#undef SIMSERIAL_DEBUG  /* define this to get some debug information */

#define KEYBOARD_INTR   3     /* must match with simulator! */

#define NR_PORTS  1     /* only one port for now */

#define IRQ_T(info) ((info->flags & ASYNC_SHARE_IRQ) ? IRQF_SHARED : IRQF_DISABLED)

#define SSC_GETCHAR     21

extern long ia64_ssc (long, long, long, long, int);
extern void ia64_ssc_connect_irq (long intr, long irq);

static char *serial_name = "SimSerial driver";
static char *serial_version = "0.6";

/*
 * This has been extracted from asm/serial.h. We need one eventually but
 * I don't know exactly what we're going to put in it so just fake one
 * for now.
 */
#define BASE_BAUD ( 1843200 / 16 )

#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)

/*
 * Most of the values here are meaningless to this particular driver.
 * However some values must be preserved for the code (leveraged from serial.c
 * to work correctly).
 * port must not be 0
 * type must not be UNKNOWN
 * So I picked arbitrary (guess from where?) values instead
 */
static struct serial_state rs_table[NR_PORTS]={
  /* UART CLK   PORT IRQ     FLAGS        */
  { 0, BASE_BAUD, 0x3F8, 0, STD_COM_FLAGS,0,PORT_16550 }  /* ttyS0 */
};

/*
 * Just for the fun of it !
 */
static struct serial_uart_config uart_config[] = {
      { "unknown", 1, 0 },
      { "8250", 1, 0 },
      { "16450", 1, 0 },
      { "16550", 1, 0 },
      { "16550A", 16, UART_CLEAR_FIFO | UART_USE_FIFO },
      { "cirrus", 1, 0 },
      { "ST16650", 1, UART_CLEAR_FIFO | UART_STARTECH },
      { "ST16650V2", 32, UART_CLEAR_FIFO | UART_USE_FIFO |
              UART_STARTECH },
      { "TI16750", 64, UART_CLEAR_FIFO | UART_USE_FIFO},
      { NULL, 0}
};

struct tty_driver *hp_simserial_driver;

static struct async_struct *IRQ_ports[NR_IRQS];

static struct console *console;

static unsigned char *tmp_buf;

extern struct console *console_drivers; /* from kernel/printk.c */

/*
 * ------------------------------------------------------------
 * 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)
{
#ifdef SIMSERIAL_DEBUG
      printk("rs_stop: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
            tty->stopped, tty->hw_stopped, tty->flow_stopped);
#endif

}

static void rs_start(struct tty_struct *tty)
{
#ifdef SIMSERIAL_DEBUG
      printk("rs_start: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
            tty->stopped, tty->hw_stopped, tty->flow_stopped);
#endif
}

static  void receive_chars(struct tty_struct *tty)
{
      unsigned char ch;
      static unsigned char seen_esc = 0;

      while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
            if ( ch == 27 && seen_esc == 0 ) {
                  seen_esc = 1;
                  continue;
            } else {
                  if ( seen_esc==1 && ch == 'O' ) {
                        seen_esc = 2;
                        continue;
                  } else if ( seen_esc == 2 ) {
                        if ( ch == 'P' ) /* F1 */
                              show_state();
#ifdef CONFIG_MAGIC_SYSRQ
                        if ( ch == 'S' ) { /* F4 */
                              do
                                    ch = ia64_ssc(0, 0, 0, 0,
                                                SSC_GETCHAR);
                              while (!ch);
                              handle_sysrq(ch, NULL);
                        }
#endif
                        seen_esc = 0;
                        continue;
                  }
            }
            seen_esc = 0;

            if (tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0)
                  break;
      }
      tty_flip_buffer_push(tty);
}

/*
 * This is the serial driver's interrupt routine for a single port
 */
static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
{
      struct async_struct * info;

      /*
       * I don't know exactly why they don't use the dev_id opaque data
       * pointer instead of this extra lookup table
       */
      info = IRQ_ports[irq];
      if (!info || !info->tty) {
            printk(KERN_INFO "simrs_interrupt_single: info|tty=0 info=%p problem\n", info);
            return IRQ_NONE;
      }
      /*
       * pretty simple in our case, because we only get interrupts
       * on inbound traffic
       */
      receive_chars(info->tty);
      return IRQ_HANDLED;
}

/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */

static void do_softint(struct work_struct *private_)
{
      printk(KERN_ERR "simserial: do_softint called\n");
}

static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
      struct async_struct *info = (struct async_struct *)tty->driver_data;
      unsigned long flags;

      if (!tty || !info->xmit.buf)
            return 0;

      local_irq_save(flags);
      if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
            local_irq_restore(flags);
            return 0;
      }
      info->xmit.buf[info->xmit.head] = ch;
      info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
      local_irq_restore(flags);
      return 1;
}

static void transmit_chars(struct async_struct *info, int *intr_done)
{
      int count;
      unsigned long flags;


      local_irq_save(flags);

      if (info->x_char) {
            char c = info->x_char;

            console->write(console, &c, 1);

            info->state->icount.tx++;
            info->x_char = 0;

            goto out;
      }

      if (info->xmit.head == info->xmit.tail || info->tty->stopped || info->tty->hw_stopped) {
#ifdef SIMSERIAL_DEBUG
            printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
                   info->xmit.head, info->xmit.tail, info->tty->stopped);
#endif
            goto out;
      }
      /*
       * We removed the loop and try to do it in to chunks. We need
       * 2 operations maximum because it's a ring buffer.
       *
       * First from current to tail if possible.
       * Then from the beginning of the buffer until necessary
       */

      count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
                SERIAL_XMIT_SIZE - info->xmit.tail);
      console->write(console, info->xmit.buf+info->xmit.tail, count);

      info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);

      /*
       * We have more at the beginning of the buffer
       */
      count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
      if (count) {
            console->write(console, info->xmit.buf, count);
            info->xmit.tail += count;
      }
out:
      local_irq_restore(flags);
}

static void rs_flush_chars(struct tty_struct *tty)
{
      struct async_struct *info = (struct async_struct *)tty->driver_data;

      if (info->xmit.head == info->xmit.tail || tty->stopped || tty->hw_stopped ||
          !info->xmit.buf)
            return;

      transmit_chars(info, NULL);
}


static int rs_write(struct tty_struct * tty,
                const unsigned char *buf, int count)
{
      int   c, ret = 0;
      struct async_struct *info = (struct async_struct *)tty->driver_data;
      unsigned long flags;

      if (!tty || !info->xmit.buf || !tmp_buf) return 0;

      local_irq_save(flags);
      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;
      }
      local_irq_restore(flags);
      /*
       * Hey, we transmit directly from here in our case
       */
      if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE)
          && !tty->stopped && !tty->hw_stopped) {
            transmit_chars(info, NULL);
      }
      return ret;
}

static int rs_write_room(struct tty_struct *tty)
{
      struct async_struct *info = (struct async_struct *)tty->driver_data;

      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;

      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;

      local_irq_save(flags);
      info->xmit.head = info->xmit.tail = 0;
      local_irq_restore(flags);

      tty_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;

      info->x_char = ch;
      if (ch) {
            /*
             * I guess we could call console->write() directly but
             * let's do that for now.
             */
            transmit_chars(info, NULL);
      }
}

/*
 * ------------------------------------------------------------
 * 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)
{
      if (I_IXOFF(tty)) rs_send_xchar(tty, STOP_CHAR(tty));

      printk(KERN_INFO "simrs_throttle called\n");
}

static void rs_unthrottle(struct tty_struct * tty)
{
      struct async_struct *info = (struct async_struct *)tty->driver_data;

      if (I_IXOFF(tty)) {
            if (info->x_char)
                  info->x_char = 0;
            else
                  rs_send_xchar(tty, START_CHAR(tty));
      }
      printk(KERN_INFO "simrs_unthrottle called\n");
}


static int rs_ioctl(struct tty_struct *tty, struct file * file,
                unsigned int cmd, unsigned long arg)
{
      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 TIOCGSERIAL:
                  printk(KERN_INFO "simrs_ioctl TIOCGSERIAL called\n");
                  return 0;
            case TIOCSSERIAL:
                  printk(KERN_INFO "simrs_ioctl TIOCSSERIAL called\n");
                  return 0;
            case TIOCSERCONFIG:
                  printk(KERN_INFO "rs_ioctl: TIOCSERCONFIG called\n");
                  return -EINVAL;

            case TIOCSERGETLSR: /* Get line status register */
                  printk(KERN_INFO "rs_ioctl: TIOCSERGETLSR called\n");
                  return  -EINVAL;

            case TIOCSERGSTRUCT:
                  printk(KERN_INFO "rs_ioctl: TIOCSERGSTRUCT called\n");
#if 0
                  if (copy_to_user((struct async_struct *) arg,
                               info, sizeof(struct async_struct)))
                        return -EFAULT;
#endif
                  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:
                  printk(KERN_INFO "rs_ioctl: TIOCMIWAIT: called\n");
                  return 0;
            /*
             * 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:
                  printk(KERN_INFO "rs_ioctl: TIOCGICOUNT called\n");
                  return 0;

            case TIOCSERGWILD:
            case TIOCSERSWILD:
                  /* "setserial -W" is called in Debian boot */
                  printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
                  return 0;

            default:
                  return -ENOIOCTLCMD;
            }
      return 0;
}

#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
      /* Handle turning off CRTSCTS */
      if ((old_termios->c_cflag & CRTSCTS) &&
          !(tty->termios->c_cflag & CRTSCTS)) {
            tty->hw_stopped = 0;
            rs_start(tty);
      }
}
/*
 * 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 SIMSERIAL_DEBUG
      printk("Shutting down serial port %d (irq %d)....", info->line,
             state->irq);
#endif

      local_irq_save(flags);
      {
            /*
             * 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;

            /*
             * Free the IRQ, if necessary
             */
            if (state->irq && (!IRQ_ports[state->irq] ||
                           !IRQ_ports[state->irq]->next_port)) {
                  if (IRQ_ports[state->irq]) {
                        free_irq(state->irq, NULL);
                        retval = request_irq(state->irq, rs_interrupt_single,
                                         IRQ_T(info), "serial", NULL);

                        if (retval)
                              printk(KERN_ERR "serial shutdown: request_irq: error %d"
                                     "  Couldn't reacquire IRQ.\n", retval);
                  } else
                        free_irq(state->irq, NULL);
            }

            if (info->xmit.buf) {
                  free_page((unsigned long) info->xmit.buf);
                  info->xmit.buf = NULL;
            }

            if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags);

            info->flags &= ~ASYNC_INITIALIZED;
      }
      local_irq_restore(flags);
}

/*
 * ------------------------------------------------------------
 * 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 ) return;

      state = info->state;

      local_irq_save(flags);
      if (tty_hung_up_p(filp)) {
#ifdef SIMSERIAL_DEBUG
            printk("rs_close: hung_up\n");
#endif
            local_irq_restore(flags);
            return;
      }
#ifdef SIMSERIAL_DEBUG
      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(KERN_ERR "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(KERN_ERR "rs_close: bad serial port count for ttys%d: %d\n",
                   info->line, state->count);
            state->count = 0;
      }
      if (state->count) {
            local_irq_restore(flags);
            return;
      }
      info->flags |= ASYNC_CLOSING;
      local_irq_restore(flags);

      /*
       * Now we wait for the transmit buffer to clear; and we notify
       * the line discipline to only process XON/XOFF characters.
       */
      shutdown(info);
      rs_flush_buffer(tty);
      tty_ldisc_flush(tty);
      info->event = 0;
      info->tty = NULL;
      if (info->blocked_open) {
            if (info->close_delay)
                  schedule_timeout_interruptible(info->close_delay);
            wake_up_interruptible(&info->open_wait);
      }
      info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
      wake_up_interruptible(&info->close_wait);
}

/*
 * rs_wait_until_sent() --- wait until the transmitter is empty
 */
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
}


/*
 * 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;

#ifdef SIMSERIAL_DEBUG
      printk("rs_hangup: called\n");
#endif

      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;
      info->tty = NULL;
      wake_up_interruptible(&info->open_wait);
}


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 = kzalloc(sizeof(struct async_struct), GFP_KERNEL);
      if (!info) {
            sstate->count--;
            return -ENOMEM;
      }
      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->xmit_fifo_size = sstate->xmit_fifo_size;
      info->line = line;
      INIT_WORK(&info->work, do_softint);
      info->state = sstate;
      if (sstate->info) {
            kfree(info);
            *ret_info = sstate->info;
            return 0;
      }
      *ret_info = sstate->info = info;
      return 0;
}

static int
startup(struct async_struct *info)
{
      unsigned long flags;
      int   retval=0;
      irq_handler_t handler;
      struct serial_state *state= info->state;
      unsigned long page;

      page = get_zeroed_page(GFP_KERNEL);
      if (!page)
            return -ENOMEM;

      local_irq_save(flags);

      if (info->flags & ASYNC_INITIALIZED) {
            free_page(page);
            goto errout;
      }

      if (!state->port || !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;

#ifdef SIMSERIAL_DEBUG
      printk("startup: ttys%d (irq %d)...", info->line, state->irq);
#endif

      /*
       * Allocate the IRQ if necessary
       */
      if (state->irq && (!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, IRQ_T(info), "simserial", NULL);
            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 = NULL;
      info->next_port = IRQ_ports[state->irq];
      if (info->next_port)
            info->next_port->prev_port = info;
      IRQ_ports[state->irq] = info;

      if (info->tty) clear_bit(TTY_IO_ERROR, &info->tty->flags);

      info->xmit.head = info->xmit.tail = 0;

#if 0
      /*
       * Set up serial timers...
       */
      timer_table[RS_TIMER].expires = jiffies + 2*HZ/100;
      timer_active |= 1 << RS_TIMER;
#endif

      /*
       * 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;
      }

      info->flags |= ASYNC_INITIALIZED;
      local_irq_restore(flags);
      return 0;

errout:
      local_irq_restore(flags);
      return retval;
}


/*
 * 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;

      line = tty->index;
      if ((line < 0) || (line >= NR_PORTS))
            return -ENODEV;
      retval = get_async_struct(line, &info);
      if (retval)
            return retval;
      tty->driver_data = info;
      info->tty = tty;

#ifdef SIMSERIAL_DEBUG
      printk("rs_open %s, count = %d\n", tty->name, 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)
                  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);
#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) {
            return retval;
      }

      /*
       * figure out which console to use (should be one already)
       */
      console = console_drivers;
      while (console) {
            if ((console->flags & CON_ENABLED) && console->write) break;
            console = console->next;
      }

#ifdef SIMSERIAL_DEBUG
      printk("rs_open ttys%d successful\n", info->line);
#endif
      return 0;
}

/*
 * /proc fs routines....
 */

static inline void line_info(struct seq_file *m, struct serial_state *state)
{
      seq_printf(m, "%d: uart:%s port:%lX irq:%d\n",
                   state->line, uart_config[state->type].name,
                   state->port, state->irq);
}

static int rs_proc_show(struct seq_file *m, void *v)
{
      int i;

      seq_printf(m, "simserinfo:1.0 driver:%s\n", serial_version);
      for (i = 0; i < NR_PORTS; i++)
            line_info(m, &rs_table[i]);
      return 0;
}

static int rs_proc_open(struct inode *inode, struct file *file)
{
      return single_open(file, rs_proc_show, NULL);
}

static const struct file_operations rs_proc_fops = {
      .owner            = THIS_MODULE,
      .open       = rs_proc_open,
      .read       = seq_read,
      .llseek           = seq_lseek,
      .release    = single_release,
};

/*
 * ---------------------------------------------------------------------
 * 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 inline void show_serial_version(void)
{
      printk(KERN_INFO "%s version %s with", serial_name, serial_version);
      printk(KERN_INFO " no serial options enabled\n");
}

static const struct tty_operations hp_ops = {
      .open = rs_open,
      .close = rs_close,
      .write = rs_write,
      .put_char = rs_put_char,
      .flush_chars = rs_flush_chars,
      .write_room = rs_write_room,
      .chars_in_buffer = rs_chars_in_buffer,
      .flush_buffer = rs_flush_buffer,
      .ioctl = rs_ioctl,
      .throttle = rs_throttle,
      .unthrottle = rs_unthrottle,
      .send_xchar = rs_send_xchar,
      .set_termios = rs_set_termios,
      .stop = rs_stop,
      .start = rs_start,
      .hangup = rs_hangup,
      .wait_until_sent = rs_wait_until_sent,
      .proc_fops = &rs_proc_fops,
};

/*
 * The serial driver boot-time initialization code!
 */
static int __init
simrs_init (void)
{
      int               i, rc;
      struct serial_state     *state;

      if (!ia64_platform_is("hpsim"))
            return -ENODEV;

      hp_simserial_driver = alloc_tty_driver(1);
      if (!hp_simserial_driver)
            return -ENOMEM;

      show_serial_version();

      /* Initialize the tty_driver structure */

      hp_simserial_driver->owner = THIS_MODULE;
      hp_simserial_driver->driver_name = "simserial";
      hp_simserial_driver->name = "ttyS";
      hp_simserial_driver->major = TTY_MAJOR;
      hp_simserial_driver->minor_start = 64;
      hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
      hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
      hp_simserial_driver->init_termios = tty_std_termios;
      hp_simserial_driver->init_termios.c_cflag =
            B9600 | CS8 | CREAD | HUPCL | CLOCAL;
      hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
      tty_set_operations(hp_simserial_driver, &hp_ops);

      /*
       * Let's have a little bit of fun !
       */
      for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {

            if (state->type == PORT_UNKNOWN) continue;

            if (!state->irq) {
                  if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0)
                        panic("%s: out of interrupt vectors!\n",
                              __func__);
                  state->irq = rc;
                  ia64_ssc_connect_irq(KEYBOARD_INTR, state->irq);
            }

            printk(KERN_INFO "ttyS%d at 0x%04lx (irq = %d) is a %s\n",
                   state->line,
                   state->port, state->irq,
                   uart_config[state->type].name);
      }

      if (tty_register_driver(hp_simserial_driver))
            panic("Couldn't register simserial driver\n");

      return 0;
}

#ifndef MODULE
__initcall(simrs_init);
#endif

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