patch-2.4.23 linux-2.4.23/arch/ia64/drivers/simserial.c

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diff -urN linux-2.4.22/arch/ia64/drivers/simserial.c linux-2.4.23/arch/ia64/drivers/simserial.c
@@ -0,0 +1,1094 @@
+/*
+ * 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.
+ */
+
+#include <linux/config.h>
+#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/slab.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/serialP.h>
+
+#include <asm/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 SERIAL_INLINE	1
+
+#ifdef SERIAL_INLINE
+#define _INLINE_ inline
+#endif
+
+#ifndef MIN
+#define MIN(a,b)	((a) < (b) ? (a) : (b))
+#endif
+
+#define IRQ_T(info) ((info->flags & ASYNC_SHARE_IRQ) ? SA_SHIRQ : SA_INTERRUPT)
+
+#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},
+	{ 0, 0}
+};
+
+static struct tty_driver serial_driver, callout_driver;
+static int serial_refcount;
+
+static struct async_struct *IRQ_ports[NR_IRQS];
+static struct tty_struct *serial_table[NR_PORTS];
+static struct termios *serial_termios[NR_PORTS];
+static struct termios *serial_termios_locked[NR_PORTS];
+
+static struct console *console;
+
+static unsigned char *tmp_buf;
+static DECLARE_MUTEX(tmp_buf_sem);
+
+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)
+{
+#if 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, struct pt_regs *regs)
+{
+	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' ) show_state();		/* F1 key */
+				if ( ch == 'Q' ) show_buffers();	/* F2 key */
+				seen_esc = 0;
+				continue;
+			}
+		}
+		seen_esc = 0;
+		if (tty->flip.count >= TTY_FLIPBUF_SIZE) break;
+
+		*tty->flip.char_buf_ptr = ch;
+
+		*tty->flip.flag_buf_ptr = 0;
+
+		tty->flip.flag_buf_ptr++;
+		tty->flip.char_buf_ptr++;
+		tty->flip.count++;
+	}
+	tty_flip_buffer_push(tty);
+}
+
+/*
+ * 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)
+{
+	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;
+	}
+	/*
+	 * pretty simple in our case, because we only get interrupts
+	 * on inbound traffic
+	 */
+	receive_chars(info->tty, regs);
+}
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the serial interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+#if 0
+/*
+ * not really used in our situation so keep them commented out for now
+ */
+static DECLARE_TASK_QUEUE(tq_serial); /* used to be at the top of the file */
+static void do_serial_bh(void)
+{
+	run_task_queue(&tq_serial);
+	printk(KERN_ERR "do_serial_bh: called\n");
+}
+#endif
+
+static void do_softint(void *private_)
+{
+	printk(KERN_ERR "simserial: do_softint called\n");
+}
+
+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 (!tty || !info->xmit.buf) return;
+
+	save_flags(flags); cli();
+	if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
+		restore_flags(flags);
+		return;
+	}
+	info->xmit.buf[info->xmit.head] = ch;
+	info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
+	restore_flags(flags);
+}
+
+static _INLINE_ void transmit_chars(struct async_struct *info, int *intr_done)
+{
+	int count;
+	unsigned long flags;
+
+	save_flags(flags); cli();
+
+	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:
+	restore_flags(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, 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 (!tty || !info->xmit.buf || !tmp_buf) return 0;
+
+	save_flags(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));
+			restore_flags(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;
+		}
+		restore_flags(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;
+
+	save_flags(flags); cli();
+	info->xmit.head = info->xmit.tail = 0;
+	restore_flags(flags);
+
+	wake_up_interruptible(&tty->write_wait);
+
+	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;
+
+	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");
+}
+
+/*
+ * rs_break() --- routine which turns the break handling on or off
+ */
+static void rs_break(struct tty_struct *tty, int break_state)
+{
+}
+
+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 TIOCMGET:
+			printk(KERN_INFO "rs_ioctl: TIOCMGET called\n");
+			return -EINVAL;
+		case TIOCMBIS:
+		case TIOCMBIC:
+		case TIOCMSET:
+			printk(KERN_INFO "rs_ioctl: TIOCMBIS/BIC/SET called\n");
+			return -EINVAL;
+		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 termios *old_termios)
+{
+	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;
+
+
+	/* 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
+
+	save_flags(flags); cli(); /* Disable interrupts */
+
+	/*
+	 * First unlink the serial port from the IRQ chain...
+	 */
+	if (info->next_port)
+		info->next_port->prev_port = info->prev_port;
+	if (info->prev_port)
+		info->prev_port->next_port = info->next_port;
+	else
+		IRQ_ports[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 = 0;
+	}
+
+	if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags);
+
+	info->flags &= ~ASYNC_INITIALIZED;
+	restore_flags(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;
+
+	save_flags(flags); cli();
+
+	if (tty_hung_up_p(filp)) {
+#ifdef SIMSERIAL_DEBUG
+		printk("rs_close: hung_up\n");
+#endif
+		MOD_DEC_USE_COUNT;
+		restore_flags(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) {
+		MOD_DEC_USE_COUNT;
+		restore_flags(flags);
+		return;
+	}
+	info->flags |= ASYNC_CLOSING;
+	restore_flags(flags);
+
+	/*
+	 * Now we wait for the transmit buffer to clear; and we notify
+	 * the line discipline to only process XON/XOFF characters.
+	 */
+	shutdown(info);
+	if (tty->driver.flush_buffer) tty->driver.flush_buffer(tty);
+	if (tty->ldisc.flush_buffer) tty->ldisc.flush_buffer(tty);
+	info->event = 0;
+	info->tty = 0;
+	if (info->blocked_open) {
+		if (info->close_delay) {
+			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)
+{
+}
+
+
+/*
+ * 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|ASYNC_CALLOUT_ACTIVE);
+	info->tty = 0;
+	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 = 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->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;
+}
+
+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_free_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	save_flags(flags); cli();
+
+	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 = 0;
+	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;
+	restore_flags(flags);
+	return 0;
+
+errout:
+	restore_flags(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;
+
+	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;
+
+#ifdef SIMSERIAL_DEBUG
+	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_free_page(GFP_KERNEL);
+		if (!page) {
+			/* MOD_DEC_USE_COUNT; "info->tty" will cause this? */
+			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; "info->tty" will cause this? */
+#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; "info->tty" will cause this? */
+		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;
+	}
+
+	/*
+	 * 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;
+	}
+
+	info->session = current->session;
+	info->pgrp = current->pgrp;
+
+#ifdef SIMSERIAL_DEBUG
+	printk("rs_open ttys%d successful\n", info->line);
+#endif
+	return 0;
+}
+
+/*
+ * /proc fs routines....
+ */
+
+static inline int line_info(char *buf, struct serial_state *state)
+{
+	return sprintf(buf, "%d: uart:%s port:%lX irq:%d\n",
+		       state->line, uart_config[state->type].name,
+		       state->port, state->irq);
+}
+
+static 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, "simserinfo:1.0 driver:%s\n", serial_version);
+	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 + (begin-off);
+	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 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");
+}
+
+/*
+ * The serial driver boot-time initialization code!
+ */
+static int __init
+simrs_init (void)
+{
+	int			i;
+	struct serial_state	*state;
+
+	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 = "simserial";
+	serial_driver.name = "ttyS";
+	serial_driver.major = TTY_MAJOR;
+	serial_driver.minor_start = 64;
+	serial_driver.num = 1;
+	serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
+	serial_driver.subtype = SERIAL_TYPE_NORMAL;
+	serial_driver.init_termios = tty_std_termios;
+	serial_driver.init_termios.c_cflag =
+		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	serial_driver.flags = TTY_DRIVER_REAL_RAW;
+	serial_driver.refcount = &serial_refcount;
+	serial_driver.table = serial_table;
+	serial_driver.termios = serial_termios;
+	serial_driver.termios_locked = serial_termios_locked;
+
+	serial_driver.open = rs_open;
+	serial_driver.close = rs_close;
+	serial_driver.write = rs_write;
+	serial_driver.put_char = rs_put_char;
+	serial_driver.flush_chars = rs_flush_chars;
+	serial_driver.write_room = rs_write_room;
+	serial_driver.chars_in_buffer = rs_chars_in_buffer;
+	serial_driver.flush_buffer = rs_flush_buffer;
+	serial_driver.ioctl = rs_ioctl;
+	serial_driver.throttle = rs_throttle;
+	serial_driver.unthrottle = rs_unthrottle;
+	serial_driver.send_xchar = rs_send_xchar;
+	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.wait_until_sent = rs_wait_until_sent;
+	serial_driver.read_proc = rs_read_proc;
+
+	/*
+	 * 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) {
+			state->irq = ia64_alloc_vector();
+			ia64_ssc_connect_irq(KEYBOARD_INTR, state->irq);
+		}
+
+		printk(KERN_INFO "ttyS%02d at 0x%04lx (irq = %d) is a %s\n",
+		       state->line,
+		       state->port, state->irq,
+		       uart_config[state->type].name);
+	}
+	/*
+	 * The callout device is just like normal device except for
+	 * major number and the subtype code.
+	 */
+	callout_driver = serial_driver;
+	callout_driver.name = "cua";
+	callout_driver.major = TTYAUX_MAJOR;
+	callout_driver.subtype = SERIAL_TYPE_CALLOUT;
+	callout_driver.read_proc = 0;
+	callout_driver.proc_entry = 0;
+
+	if (tty_register_driver(&serial_driver))
+		panic("Couldn't register simserial driver\n");
+
+	if (tty_register_driver(&callout_driver))
+		panic("Couldn't register callout driver\n");
+
+	return 0;
+}
+
+#ifndef MODULE
+__initcall(simrs_init);
+#endif
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)