Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2395 insertions, 0 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
new file mode 100644
index 000000000000..36b1ae083fb7
--- /dev/null
+++ b/drivers/serial/serial_core.c
@@ -0,0 +1,2395 @@
+/*
+ *  linux/drivers/char/core.c
+ *
+ *  Driver core for serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright 1999 ARM Limited
+ *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
+ *
+ * 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 program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/smp_lock.h>
+#include <linux/device.h>
+#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
+#include <linux/delay.h>
+
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+
+#undef	DEBUG
+#ifdef DEBUG
+#define DPRINTK(x...)	printk(x)
+#else
+#define DPRINTK(x...)	do { } while (0)
+#endif
+
+/*
+ * This is used to lock changes in serial line configuration.
+ */
+static DECLARE_MUTEX(port_sem);
+
+#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
+
+#define uart_users(state)	((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
+
+#ifdef CONFIG_SERIAL_CORE_CONSOLE
+#define uart_console(port)	((port)->cons && (port)->cons->index == (port)->line)
+#else
+#define uart_console(port)	(0)
+#endif
+
+static void uart_change_speed(struct uart_state *state, struct termios *old_termios);
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
+static void uart_change_pm(struct uart_state *state, int pm_state);
+
+/*
+ * This routine is used by the interrupt handler to schedule processing in
+ * the software interrupt portion of the driver.
+ */
+void uart_write_wakeup(struct uart_port *port)
+{
+	struct uart_info *info = port->info;
+	tasklet_schedule(&info->tlet);
+}
+
+static void uart_stop(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->ops->stop_tx(port, 1);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void __uart_start(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+
+	if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
+	    !tty->stopped && !tty->hw_stopped)
+		port->ops->start_tx(port, 1);
+}
+
+static void uart_start(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	__uart_start(tty);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void uart_tasklet_action(unsigned long data)
+{
+	struct uart_state *state = (struct uart_state *)data;
+	tty_wakeup(state->info->tty);
+}
+
+static inline void
+uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
+{
+	unsigned long flags;
+	unsigned int old;
+
+	spin_lock_irqsave(&port->lock, flags);
+	old = port->mctrl;
+	port->mctrl = (old & ~clear) | set;
+	if (old != port->mctrl)
+		port->ops->set_mctrl(port, port->mctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#define uart_set_mctrl(port,set)	uart_update_mctrl(port,set,0)
+#define uart_clear_mctrl(port,clear)	uart_update_mctrl(port,0,clear)
+
+/*
+ * Startup the port.  This will be called once per open.  All calls
+ * will be serialised by the per-port semaphore.
+ */
+static int uart_startup(struct uart_state *state, int init_hw)
+{
+	struct uart_info *info = state->info;
+	struct uart_port *port = state->port;
+	unsigned long page;
+	int retval = 0;
+
+	if (info->flags & UIF_INITIALIZED)
+		return 0;
+
+	/*
+	 * Set the TTY IO error marker - we will only clear this
+	 * once we have successfully opened the port.  Also set
+	 * up the tty->alt_speed kludge
+	 */
+	if (info->tty)
+		set_bit(TTY_IO_ERROR, &info->tty->flags);
+
+	if (port->type == PORT_UNKNOWN)
+		return 0;
+
+	/*
+	 * Initialise and allocate the transmit and temporary
+	 * buffer.
+	 */
+	if (!info->xmit.buf) {
+		page = get_zeroed_page(GFP_KERNEL);
+		if (!page)
+			return -ENOMEM;
+
+		info->xmit.buf = (unsigned char *) page;
+		uart_circ_clear(&info->xmit);
+	}
+
+	retval = port->ops->startup(port);
+	if (retval == 0) {
+		if (init_hw) {
+			/*
+			 * Initialise the hardware port settings.
+			 */
+			uart_change_speed(state, NULL);
+
+			/*
+			 * Setup the RTS and DTR signals once the
+			 * port is open and ready to respond.
+			 */
+			if (info->tty->termios->c_cflag & CBAUD)
+				uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
+		}
+
+		info->flags |= UIF_INITIALIZED;
+
+		clear_bit(TTY_IO_ERROR, &info->tty->flags);
+	}
+
+	if (retval && capable(CAP_SYS_ADMIN))
+		retval = 0;
+
+	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.  Calls to
+ * uart_shutdown are serialised by the per-port semaphore.
+ */
+static void uart_shutdown(struct uart_state *state)
+{
+	struct uart_info *info = state->info;
+	struct uart_port *port = state->port;
+
+	if (!(info->flags & UIF_INITIALIZED))
+		return;
+
+	/*
+	 * Turn off DTR and RTS early.
+	 */
+	if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
+		uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
+
+	/*
+	 * clear delta_msr_wait queue to avoid mem leaks: we may free
+	 * the irq here so the queue might never be woken up.  Note
+	 * that we won't end up waiting on delta_msr_wait again since
+	 * any outstanding file descriptors should be pointing at
+	 * hung_up_tty_fops now.
+	 */
+	wake_up_interruptible(&info->delta_msr_wait);
+
+	/*
+	 * Free the IRQ and disable the port.
+	 */
+	port->ops->shutdown(port);
+
+	/*
+	 * Ensure that the IRQ handler isn't running on another CPU.
+	 */
+	synchronize_irq(port->irq);
+
+	/*
+	 * Free the transmit buffer page.
+	 */
+	if (info->xmit.buf) {
+		free_page((unsigned long)info->xmit.buf);
+		info->xmit.buf = NULL;
+	}
+
+	/*
+	 * kill off our tasklet
+	 */
+	tasklet_kill(&info->tlet);
+	if (info->tty)
+		set_bit(TTY_IO_ERROR, &info->tty->flags);
+
+	info->flags &= ~UIF_INITIALIZED;
+}
+
+/**
+ *	uart_update_timeout - update per-port FIFO timeout.
+ *	@port:  uart_port structure describing the port
+ *	@cflag: termios cflag value
+ *	@baud:  speed of the port
+ *
+ *	Set the port FIFO timeout value.  The @cflag value should
+ *	reflect the actual hardware settings.
+ */
+void
+uart_update_timeout(struct uart_port *port, unsigned int cflag,
+		    unsigned int baud)
+{
+	unsigned int bits;
+
+	/* byte size and parity */
+	switch (cflag & CSIZE) {
+	case CS5:
+		bits = 7;
+		break;
+	case CS6:
+		bits = 8;
+		break;
+	case CS7:
+		bits = 9;
+		break;
+	default:
+		bits = 10;
+		break; // CS8
+	}
+
+	if (cflag & CSTOPB)
+		bits++;
+	if (cflag & PARENB)
+		bits++;
+
+	/*
+	 * The total number of bits to be transmitted in the fifo.
+	 */
+	bits = bits * port->fifosize;
+
+	/*
+	 * Figure the timeout to send the above number of bits.
+	 * Add .02 seconds of slop
+	 */
+	port->timeout = (HZ * bits) / baud + HZ/50;
+}
+
+EXPORT_SYMBOL(uart_update_timeout);
+
+/**
+ *	uart_get_baud_rate - return baud rate for a particular port
+ *	@port: uart_port structure describing the port in question.
+ *	@termios: desired termios settings.
+ *	@old: old termios (or NULL)
+ *	@min: minimum acceptable baud rate
+ *	@max: maximum acceptable baud rate
+ *
+ *	Decode the termios structure into a numeric baud rate,
+ *	taking account of the magic 38400 baud rate (with spd_*
+ *	flags), and mapping the %B0 rate to 9600 baud.
+ *
+ *	If the new baud rate is invalid, try the old termios setting.
+ *	If it's still invalid, we try 9600 baud.
+ *
+ *	Update the @termios structure to reflect the baud rate
+ *	we're actually going to be using.
+ */
+unsigned int
+uart_get_baud_rate(struct uart_port *port, struct termios *termios,
+		   struct termios *old, unsigned int min, unsigned int max)
+{
+	unsigned int try, baud, altbaud = 38400;
+	unsigned int flags = port->flags & UPF_SPD_MASK;
+
+	if (flags == UPF_SPD_HI)
+		altbaud = 57600;
+	if (flags == UPF_SPD_VHI)
+		altbaud = 115200;
+	if (flags == UPF_SPD_SHI)
+		altbaud = 230400;
+	if (flags == UPF_SPD_WARP)
+		altbaud = 460800;
+
+	for (try = 0; try < 2; try++) {
+		baud = tty_termios_baud_rate(termios);
+
+		/*
+		 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
+		 * Die! Die! Die!
+		 */
+		if (baud == 38400)
+			baud = altbaud;
+
+		/*
+		 * Special case: B0 rate.
+		 */
+		if (baud == 0)
+			baud = 9600;
+
+		if (baud >= min && baud <= max)
+			return baud;
+
+		/*
+		 * Oops, the quotient was zero.  Try again with
+		 * the old baud rate if possible.
+		 */
+		termios->c_cflag &= ~CBAUD;
+		if (old) {
+			termios->c_cflag |= old->c_cflag & CBAUD;
+			old = NULL;
+			continue;
+		}
+
+		/*
+		 * As a last resort, if the quotient is zero,
+		 * default to 9600 bps
+		 */
+		termios->c_cflag |= B9600;
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL(uart_get_baud_rate);
+
+/**
+ *	uart_get_divisor - return uart clock divisor
+ *	@port: uart_port structure describing the port.
+ *	@baud: desired baud rate
+ *
+ *	Calculate the uart clock divisor for the port.
+ */
+unsigned int
+uart_get_divisor(struct uart_port *port, unsigned int baud)
+{
+	unsigned int quot;
+
+	/*
+	 * Old custom speed handling.
+	 */
+	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
+		quot = port->custom_divisor;
+	else
+		quot = (port->uartclk + (8 * baud)) / (16 * baud);
+
+	return quot;
+}
+
+EXPORT_SYMBOL(uart_get_divisor);
+
+static void
+uart_change_speed(struct uart_state *state, struct termios *old_termios)
+{
+	struct tty_struct *tty = state->info->tty;
+	struct uart_port *port = state->port;
+	struct termios *termios;
+
+	/*
+	 * If we have no tty, termios, or the port does not exist,
+	 * then we can't set the parameters for this port.
+	 */
+	if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
+		return;
+
+	termios = tty->termios;
+
+	/*
+	 * Set flags based on termios cflag
+	 */
+	if (termios->c_cflag & CRTSCTS)
+		state->info->flags |= UIF_CTS_FLOW;
+	else
+		state->info->flags &= ~UIF_CTS_FLOW;
+
+	if (termios->c_cflag & CLOCAL)
+		state->info->flags &= ~UIF_CHECK_CD;
+	else
+		state->info->flags |= UIF_CHECK_CD;
+
+	port->ops->set_termios(port, termios, old_termios);
+}
+
+static inline void
+__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
+{
+	unsigned long flags;
+
+	if (!circ->buf)
+		return;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (uart_circ_chars_free(circ) != 0) {
+		circ->buf[circ->head] = c;
+		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void uart_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	struct uart_state *state = tty->driver_data;
+
+	__uart_put_char(state->port, &state->info->xmit, ch);
+}
+
+static void uart_flush_chars(struct tty_struct *tty)
+{
+	uart_start(tty);
+}
+
+static int
+uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	struct circ_buf *circ = &state->info->xmit;
+	unsigned long flags;
+	int c, ret = 0;
+
+	if (!circ->buf)
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+	while (1) {
+		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
+		if (count < c)
+			c = count;
+		if (c <= 0)
+			break;
+		memcpy(circ->buf + circ->head, buf, c);
+		circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
+		buf += c;
+		count -= c;
+		ret += c;
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	uart_start(tty);
+	return ret;
+}
+
+static int uart_write_room(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+
+	return uart_circ_chars_free(&state->info->xmit);
+}
+
+static int uart_chars_in_buffer(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+
+	return uart_circ_chars_pending(&state->info->xmit);
+}
+
+static void uart_flush_buffer(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	unsigned long flags;
+
+	DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_circ_clear(&state->info->xmit);
+	spin_unlock_irqrestore(&port->lock, flags);
+	tty_wakeup(tty);
+}
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ */
+static void uart_send_xchar(struct tty_struct *tty, char ch)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	unsigned long flags;
+
+	if (port->ops->send_xchar)
+		port->ops->send_xchar(port, ch);
+	else {
+		port->x_char = ch;
+		if (ch) {
+			spin_lock_irqsave(&port->lock, flags);
+			port->ops->start_tx(port, 0);
+			spin_unlock_irqrestore(&port->lock, flags);
+		}
+	}
+}
+
+static void uart_throttle(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+
+	if (I_IXOFF(tty))
+		uart_send_xchar(tty, STOP_CHAR(tty));
+
+	if (tty->termios->c_cflag & CRTSCTS)
+		uart_clear_mctrl(state->port, TIOCM_RTS);
+}
+
+static void uart_unthrottle(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+
+	if (I_IXOFF(tty)) {
+		if (port->x_char)
+			port->x_char = 0;
+		else
+			uart_send_xchar(tty, START_CHAR(tty));
+	}
+
+	if (tty->termios->c_cflag & CRTSCTS)
+		uart_set_mctrl(port, TIOCM_RTS);
+}
+
+static int uart_get_info(struct uart_state *state,
+			 struct serial_struct __user *retinfo)
+{
+	struct uart_port *port = state->port;
+	struct serial_struct tmp;
+
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.type	    = port->type;
+	tmp.line	    = port->line;
+	tmp.port	    = port->iobase;
+	if (HIGH_BITS_OFFSET)
+		tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
+	tmp.irq		    = port->irq;
+	tmp.flags	    = port->flags;
+	tmp.xmit_fifo_size  = port->fifosize;
+	tmp.baud_base	    = port->uartclk / 16;
+	tmp.close_delay	    = state->close_delay / 10;
+	tmp.closing_wait    = state->closing_wait == USF_CLOSING_WAIT_NONE ?
+				ASYNC_CLOSING_WAIT_NONE :
+			        state->closing_wait / 10;
+	tmp.custom_divisor  = port->custom_divisor;
+	tmp.hub6	    = port->hub6;
+	tmp.io_type         = port->iotype;
+	tmp.iomem_reg_shift = port->regshift;
+	tmp.iomem_base      = (void *)port->mapbase;
+
+	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+		return -EFAULT;
+	return 0;
+}
+
+static int uart_set_info(struct uart_state *state,
+			 struct serial_struct __user *newinfo)
+{
+	struct serial_struct new_serial;
+	struct uart_port *port = state->port;
+	unsigned long new_port;
+	unsigned int change_irq, change_port, old_flags, closing_wait;
+	unsigned int old_custom_divisor, close_delay;
+	int retval = 0;
+
+	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
+		return -EFAULT;
+
+	new_port = new_serial.port;
+	if (HIGH_BITS_OFFSET)
+		new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
+
+	new_serial.irq = irq_canonicalize(new_serial.irq);
+	close_delay = new_serial.close_delay * 10;
+	closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+			USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
+
+	/*
+	 * This semaphore protects state->count.  It is also
+	 * very useful to prevent opens.  Also, take the
+	 * port configuration semaphore to make sure that a
+	 * module insertion/removal doesn't change anything
+	 * under us.
+	 */
+	down(&state->sem);
+
+	change_irq  = new_serial.irq != port->irq;
+
+	/*
+	 * Since changing the 'type' of the port changes its resource
+	 * allocations, we should treat type changes the same as
+	 * IO port changes.
+	 */
+	change_port = new_port != port->iobase ||
+		      (unsigned long)new_serial.iomem_base != port->mapbase ||
+		      new_serial.hub6 != port->hub6 ||
+		      new_serial.io_type != port->iotype ||
+		      new_serial.iomem_reg_shift != port->regshift ||
+		      new_serial.type != port->type;
+
+	old_flags = port->flags;
+	old_custom_divisor = port->custom_divisor;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		retval = -EPERM;
+		if (change_irq || change_port ||
+		    (new_serial.baud_base != port->uartclk / 16) ||
+		    (close_delay != state->close_delay) ||
+		    (closing_wait != state->closing_wait) ||
+		    (new_serial.xmit_fifo_size != port->fifosize) ||
+		    (((new_serial.flags ^ old_flags) & ~UPF_USR_MASK) != 0))
+			goto exit;
+		port->flags = ((port->flags & ~UPF_USR_MASK) |
+			       (new_serial.flags & UPF_USR_MASK));
+		port->custom_divisor = new_serial.custom_divisor;
+		goto check_and_exit;
+	}
+
+	/*
+	 * Ask the low level driver to verify the settings.
+	 */
+	if (port->ops->verify_port)
+		retval = port->ops->verify_port(port, &new_serial);
+
+	if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
+	    (new_serial.baud_base < 9600))
+		retval = -EINVAL;
+
+	if (retval)
+		goto exit;
+
+	if (change_port || change_irq) {
+		retval = -EBUSY;
+
+		/*
+		 * Make sure that we are the sole user of this port.
+		 */
+		if (uart_users(state) > 1)
+			goto exit;
+
+		/*
+		 * We need to shutdown the serial port at the old
+		 * port/type/irq combination.
+		 */
+		uart_shutdown(state);
+	}
+
+	if (change_port) {
+		unsigned long old_iobase, old_mapbase;
+		unsigned int old_type, old_iotype, old_hub6, old_shift;
+
+		old_iobase = port->iobase;
+		old_mapbase = port->mapbase;
+		old_type = port->type;
+		old_hub6 = port->hub6;
+		old_iotype = port->iotype;
+		old_shift = port->regshift;
+
+		/*
+		 * Free and release old regions
+		 */
+		if (old_type != PORT_UNKNOWN)
+			port->ops->release_port(port);
+
+		port->iobase = new_port;
+		port->type = new_serial.type;
+		port->hub6 = new_serial.hub6;
+		port->iotype = new_serial.io_type;
+		port->regshift = new_serial.iomem_reg_shift;
+		port->mapbase = (unsigned long)new_serial.iomem_base;
+
+		/*
+		 * Claim and map the new regions
+		 */
+		if (port->type != PORT_UNKNOWN) {
+			retval = port->ops->request_port(port);
+		} else {
+			/* Always success - Jean II */
+			retval = 0;
+		}
+
+		/*
+		 * If we fail to request resources for the
+		 * new port, try to restore the old settings.
+		 */
+		if (retval && old_type != PORT_UNKNOWN) {
+			port->iobase = old_iobase;
+			port->type = old_type;
+			port->hub6 = old_hub6;
+			port->iotype = old_iotype;
+			port->regshift = old_shift;
+			port->mapbase = old_mapbase;
+			retval = port->ops->request_port(port);
+			/*
+			 * If we failed to restore the old settings,
+			 * we fail like this.
+			 */
+			if (retval)
+				port->type = PORT_UNKNOWN;
+
+			/*
+			 * We failed anyway.
+			 */
+			retval = -EBUSY;
+		}
+	}
+
+	port->irq              = new_serial.irq;
+	port->uartclk          = new_serial.baud_base * 16;
+	port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
+				 (new_serial.flags & UPF_CHANGE_MASK);
+	port->custom_divisor   = new_serial.custom_divisor;
+	state->close_delay     = close_delay;
+	state->closing_wait    = closing_wait;
+	port->fifosize         = new_serial.xmit_fifo_size;
+	if (state->info->tty)
+		state->info->tty->low_latency =
+			(port->flags & UPF_LOW_LATENCY) ? 1 : 0;
+
+ check_and_exit:
+	retval = 0;
+	if (port->type == PORT_UNKNOWN)
+		goto exit;
+	if (state->info->flags & UIF_INITIALIZED) {
+		if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
+		    old_custom_divisor != port->custom_divisor) {
+			/*
+			 * If they're setting up a custom divisor or speed,
+			 * instead of clearing it, then bitch about it. No
+			 * need to rate-limit; it's CAP_SYS_ADMIN only.
+			 */
+			if (port->flags & UPF_SPD_MASK) {
+				char buf[64];
+				printk(KERN_NOTICE
+				       "%s sets custom speed on %s. This "
+				       "is deprecated.\n", current->comm,
+				       tty_name(state->info->tty, buf));
+			}
+			uart_change_speed(state, NULL);
+		}
+	} else
+		retval = uart_startup(state, 1);
+ exit:
+	up(&state->sem);
+	return retval;
+}
+
+
+/*
+ * uart_get_lsr_info - get line status register info.
+ * Note: uart_ioctl protects us against hangups.
+ */
+static int uart_get_lsr_info(struct uart_state *state,
+			     unsigned int __user *value)
+{
+	struct uart_port *port = state->port;
+	unsigned int result;
+
+	result = port->ops->tx_empty(port);
+
+	/*
+	 * 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 (port->x_char ||
+	    ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
+	     !state->info->tty->stopped && !state->info->tty->hw_stopped))
+		result &= ~TIOCSER_TEMT;
+	
+	return put_user(result, value);
+}
+
+static int uart_tiocmget(struct tty_struct *tty, struct file *file)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	int result = -EIO;
+
+	down(&state->sem);
+	if ((!file || !tty_hung_up_p(file)) &&
+	    !(tty->flags & (1 << TTY_IO_ERROR))) {
+		result = port->mctrl;
+		result |= port->ops->get_mctrl(port);
+	}
+	up(&state->sem);
+
+	return result;
+}
+
+static int
+uart_tiocmset(struct tty_struct *tty, struct file *file,
+	      unsigned int set, unsigned int clear)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	int ret = -EIO;
+
+	down(&state->sem);
+	if ((!file || !tty_hung_up_p(file)) &&
+	    !(tty->flags & (1 << TTY_IO_ERROR))) {
+		uart_update_mctrl(port, set, clear);
+		ret = 0;
+	}
+	up(&state->sem);
+	return ret;
+}
+
+static void uart_break_ctl(struct tty_struct *tty, int break_state)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+
+	BUG_ON(!kernel_locked());
+
+	down(&state->sem);
+
+	if (port->type != PORT_UNKNOWN)
+		port->ops->break_ctl(port, break_state);
+
+	up(&state->sem);
+}
+
+static int uart_do_autoconfig(struct uart_state *state)
+{
+	struct uart_port *port = state->port;
+	int flags, ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/*
+	 * Take the per-port semaphore.  This prevents count from
+	 * changing, and hence any extra opens of the port while
+	 * we're auto-configuring.
+	 */
+	if (down_interruptible(&state->sem))
+		return -ERESTARTSYS;
+
+	ret = -EBUSY;
+	if (uart_users(state) == 1) {
+		uart_shutdown(state);
+
+		/*
+		 * If we already have a port type configured,
+		 * we must release its resources.
+		 */
+		if (port->type != PORT_UNKNOWN)
+			port->ops->release_port(port);
+
+		flags = UART_CONFIG_TYPE;
+		if (port->flags & UPF_AUTO_IRQ)
+			flags |= UART_CONFIG_IRQ;
+
+		/*
+		 * This will claim the ports resources if
+		 * a port is found.
+		 */
+		port->ops->config_port(port, flags);
+
+		ret = uart_startup(state, 1);
+	}
+	up(&state->sem);
+	return ret;
+}
+
+/*
+ * 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
+ */
+static int
+uart_wait_modem_status(struct uart_state *state, unsigned long arg)
+{
+	struct uart_port *port = state->port;
+	DECLARE_WAITQUEUE(wait, current);
+	struct uart_icount cprev, cnow;
+	int ret;
+
+	/*
+	 * note the counters on entry
+	 */
+	spin_lock_irq(&port->lock);
+	memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
+
+	/*
+	 * Force modem status interrupts on
+	 */
+	port->ops->enable_ms(port);
+	spin_unlock_irq(&port->lock);
+
+	add_wait_queue(&state->info->delta_msr_wait, &wait);
+	for (;;) {
+		spin_lock_irq(&port->lock);
+		memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
+		spin_unlock_irq(&port->lock);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		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))) {
+		    	ret = 0;
+		    	break;
+		}
+
+		schedule();
+
+		/* see if a signal did it */
+		if (signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+
+		cprev = cnow;
+	}
+
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&state->info->delta_msr_wait, &wait);
+
+	return ret;
+}
+
+/*
+ * 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.
+ */
+static int uart_get_count(struct uart_state *state,
+			  struct serial_icounter_struct __user *icnt)
+{
+	struct serial_icounter_struct icount;
+	struct uart_icount cnow;
+	struct uart_port *port = state->port;
+
+	spin_lock_irq(&port->lock);
+	memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
+	spin_unlock_irq(&port->lock);
+
+	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;
+
+	return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
+}
+
+/*
+ * Called via sys_ioctl under the BKL.  We can use spin_lock_irq() here.
+ */
+static int
+uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
+	   unsigned long arg)
+{
+	struct uart_state *state = tty->driver_data;
+	void __user *uarg = (void __user *)arg;
+	int ret = -ENOIOCTLCMD;
+
+	BUG_ON(!kernel_locked());
+
+	/*
+	 * These ioctls don't rely on the hardware to be present.
+	 */
+	switch (cmd) {
+	case TIOCGSERIAL:
+		ret = uart_get_info(state, uarg);
+		break;
+
+	case TIOCSSERIAL:
+		ret = uart_set_info(state, uarg);
+		break;
+
+	case TIOCSERCONFIG:
+		ret = uart_do_autoconfig(state);
+		break;
+
+	case TIOCSERGWILD: /* obsolete */
+	case TIOCSERSWILD: /* obsolete */
+		ret = 0;
+		break;
+	}
+
+	if (ret != -ENOIOCTLCMD)
+		goto out;
+
+	if (tty->flags & (1 << TTY_IO_ERROR)) {
+		ret = -EIO;
+		goto out;
+	}
+
+	/*
+	 * The following should only be used when hardware is present.
+	 */
+	switch (cmd) {
+	case TIOCMIWAIT:
+		ret = uart_wait_modem_status(state, arg);
+		break;
+
+	case TIOCGICOUNT:
+		ret = uart_get_count(state, uarg);
+		break;
+	}
+
+	if (ret != -ENOIOCTLCMD)
+		goto out;
+
+	down(&state->sem);
+
+	if (tty_hung_up_p(filp)) {
+		ret = -EIO;
+		goto out_up;
+	}
+
+	/*
+	 * All these rely on hardware being present and need to be
+	 * protected against the tty being hung up.
+	 */
+	switch (cmd) {
+	case TIOCSERGETLSR: /* Get line status register */
+		ret = uart_get_lsr_info(state, uarg);
+		break;
+
+	default: {
+		struct uart_port *port = state->port;
+		if (port->ops->ioctl)
+			ret = port->ops->ioctl(port, cmd, arg);
+		break;
+	}
+	}
+ out_up:
+	up(&state->sem);
+ out:
+	return ret;
+}
+
+static void uart_set_termios(struct tty_struct *tty, struct termios *old_termios)
+{
+	struct uart_state *state = tty->driver_data;
+	unsigned long flags;
+	unsigned int cflag = tty->termios->c_cflag;
+
+	BUG_ON(!kernel_locked());
+
+	/*
+	 * These are the bits that are used to setup various
+	 * flags in the low level driver.
+	 */
+#define RELEVANT_IFLAG(iflag)	((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
+
+	if ((cflag ^ old_termios->c_cflag) == 0 &&
+	    RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
+		return;
+
+	uart_change_speed(state, old_termios);
+
+	/* Handle transition to B0 status */
+	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
+		uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
+
+	/* Handle transition away from B0 status */
+	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
+		unsigned int mask = TIOCM_DTR;
+		if (!(cflag & CRTSCTS) ||
+		    !test_bit(TTY_THROTTLED, &tty->flags))
+			mask |= TIOCM_RTS;
+		uart_set_mctrl(state->port, mask);
+	}
+
+	/* Handle turning off CRTSCTS */
+	if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
+		spin_lock_irqsave(&state->port->lock, flags);
+		tty->hw_stopped = 0;
+		__uart_start(tty);
+		spin_unlock_irqrestore(&state->port->lock, flags);
+	}
+
+#if 0
+	/*
+	 * No need to wake up processes in open wait, since they
+	 * sample the CLOCAL flag once, and don't recheck it.
+	 * XXX  It's not clear whether the current behavior is correct
+	 * or not.  Hence, this may change.....
+	 */
+	if (!(old_termios->c_cflag & CLOCAL) &&
+	    (tty->termios->c_cflag & CLOCAL))
+		wake_up_interruptible(&state->info->open_wait);
+#endif
+}
+
+/*
+ * In 2.4.5, calls to this will be serialized via the BKL in
+ *  linux/drivers/char/tty_io.c:tty_release()
+ *  linux/drivers/char/tty_io.c:do_tty_handup()
+ */
+static void uart_close(struct tty_struct *tty, struct file *filp)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	
+	BUG_ON(!kernel_locked());
+
+	if (!state || !state->port)
+		return;
+
+	port = state->port;
+
+	DPRINTK("uart_close(%d) called\n", port->line);
+
+	down(&state->sem);
+
+	if (tty_hung_up_p(filp))
+		goto done;
+
+	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 "uart_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 "uart_close: bad serial port count for %s: %d\n",
+		       tty->name, state->count);
+		state->count = 0;
+	}
+	if (state->count)
+		goto done;
+
+	/*
+	 * Now we wait for the transmit buffer to clear; and we notify
+	 * the line discipline to only process XON/XOFF characters by
+	 * setting tty->closing.
+	 */
+	tty->closing = 1;
+
+	if (state->closing_wait != USF_CLOSING_WAIT_NONE)
+		tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
+
+	/*
+	 * At this point, we stop accepting input.  To do this, we
+	 * disable the receive line status interrupts.
+	 */
+	if (state->info->flags & UIF_INITIALIZED) {
+		unsigned long flags;
+		spin_lock_irqsave(&port->lock, flags);
+		port->ops->stop_rx(port);
+		spin_unlock_irqrestore(&port->lock, flags);
+		/*
+		 * Before we drop DTR, make sure the UART transmitter
+		 * has completely drained; this is especially
+		 * important if there is a transmit FIFO!
+		 */
+		uart_wait_until_sent(tty, port->timeout);
+	}
+
+	uart_shutdown(state);
+	uart_flush_buffer(tty);
+
+	tty_ldisc_flush(tty);	
+	
+	tty->closing = 0;
+	state->info->tty = NULL;
+
+	if (state->info->blocked_open) {
+		if (state->close_delay)
+			msleep_interruptible(state->close_delay);
+	} else if (!uart_console(port)) {
+		uart_change_pm(state, 3);
+	}
+
+	/*
+	 * Wake up anyone trying to open this port.
+	 */
+	state->info->flags &= ~UIF_NORMAL_ACTIVE;
+	wake_up_interruptible(&state->info->open_wait);
+
+ done:
+	up(&state->sem);
+}
+
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->port;
+	unsigned long char_time, expire;
+
+	BUG_ON(!kernel_locked());
+
+	if (port->type == PORT_UNKNOWN || port->fifosize == 0)
+		return;
+
+	/*
+	 * 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 = (port->timeout - HZ/50) / port->fifosize;
+	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 port->timeout, this is probably due to a
+	 * UART bug of some kind.  So, we clamp the timeout parameter at
+	 * 2*port->timeout.
+	 */
+	if (timeout == 0 || timeout > 2 * port->timeout)
+		timeout = 2 * port->timeout;
+
+	expire = jiffies + timeout;
+
+	DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
+	        port->line, jiffies, expire);
+
+	/*
+	 * Check whether the transmitter is empty every 'char_time'.
+	 * 'timeout' / 'expire' give us the maximum amount of time
+	 * we wait.
+	 */
+	while (!port->ops->tx_empty(port)) {
+		msleep_interruptible(jiffies_to_msecs(char_time));
+		if (signal_pending(current))
+			break;
+		if (time_after(jiffies, expire))
+			break;
+	}
+	set_current_state(TASK_RUNNING); /* might not be needed */
+}
+
+/*
+ * This is called with the BKL held in
+ *  linux/drivers/char/tty_io.c:do_tty_hangup()
+ * We're called from the eventd thread, so we can sleep for
+ * a _short_ time only.
+ */
+static void uart_hangup(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+
+	BUG_ON(!kernel_locked());
+	DPRINTK("uart_hangup(%d)\n", state->port->line);
+
+	down(&state->sem);
+	if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
+		uart_flush_buffer(tty);
+		uart_shutdown(state);
+		state->count = 0;
+		state->info->flags &= ~UIF_NORMAL_ACTIVE;
+		state->info->tty = NULL;
+		wake_up_interruptible(&state->info->open_wait);
+		wake_up_interruptible(&state->info->delta_msr_wait);
+	}
+	up(&state->sem);
+}
+
+/*
+ * Copy across the serial console cflag setting into the termios settings
+ * for the initial open of the port.  This allows continuity between the
+ * kernel settings, and the settings init adopts when it opens the port
+ * for the first time.
+ */
+static void uart_update_termios(struct uart_state *state)
+{
+	struct tty_struct *tty = state->info->tty;
+	struct uart_port *port = state->port;
+
+	if (uart_console(port) && port->cons->cflag) {
+		tty->termios->c_cflag = port->cons->cflag;
+		port->cons->cflag = 0;
+	}
+
+	/*
+	 * If the device failed to grab its irq resources,
+	 * or some other error occurred, don't try to talk
+	 * to the port hardware.
+	 */
+	if (!(tty->flags & (1 << TTY_IO_ERROR))) {
+		/*
+		 * Make termios settings take effect.
+		 */
+		uart_change_speed(state, NULL);
+
+		/*
+		 * And finally enable the RTS and DTR signals.
+		 */
+		if (tty->termios->c_cflag & CBAUD)
+			uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
+	}
+}
+
+/*
+ * Block the open until the port is ready.  We must be called with
+ * the per-port semaphore held.
+ */
+static int
+uart_block_til_ready(struct file *filp, struct uart_state *state)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	struct uart_info *info = state->info;
+	struct uart_port *port = state->port;
+
+	info->blocked_open++;
+	state->count--;
+
+	add_wait_queue(&info->open_wait, &wait);
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		/*
+		 * If we have been hung up, tell userspace/restart open.
+		 */
+		if (tty_hung_up_p(filp) || info->tty == NULL)
+			break;
+
+		/*
+		 * If the port has been closed, tell userspace/restart open.
+		 */
+		if (!(info->flags & UIF_INITIALIZED))
+			break;
+
+		/*
+		 * If non-blocking mode is set, or CLOCAL mode is set,
+		 * we don't want to wait for the modem status lines to
+		 * indicate that the port is ready.
+		 *
+		 * Also, if the port is not enabled/configured, we want
+		 * to allow the open to succeed here.  Note that we will
+		 * have set TTY_IO_ERROR for a non-existant port.
+		 */
+		if ((filp->f_flags & O_NONBLOCK) ||
+	            (info->tty->termios->c_cflag & CLOCAL) ||
+		    (info->tty->flags & (1 << TTY_IO_ERROR))) {
+			break;
+		}
+
+		/*
+		 * Set DTR to allow modem to know we're waiting.  Do
+		 * not set RTS here - we want to make sure we catch
+		 * the data from the modem.
+		 */
+		if (info->tty->termios->c_cflag & CBAUD)
+			uart_set_mctrl(port, TIOCM_DTR);
+
+		/*
+		 * and wait for the carrier to indicate that the
+		 * modem is ready for us.
+		 */
+		if (port->ops->get_mctrl(port) & TIOCM_CAR)
+			break;
+
+		up(&state->sem);
+		schedule();
+		down(&state->sem);
+
+		if (signal_pending(current))
+			break;
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&info->open_wait, &wait);
+
+	state->count++;
+	info->blocked_open--;
+
+	if (signal_pending(current))
+		return -ERESTARTSYS;
+
+	if (!info->tty || tty_hung_up_p(filp))
+		return -EAGAIN;
+
+	return 0;
+}
+
+static struct uart_state *uart_get(struct uart_driver *drv, int line)
+{
+	struct uart_state *state;
+
+	down(&port_sem);
+	state = drv->state + line;
+	if (down_interruptible(&state->sem)) {
+		state = ERR_PTR(-ERESTARTSYS);
+		goto out;
+	}
+
+	state->count++;
+	if (!state->port) {
+		state->count--;
+		up(&state->sem);
+		state = ERR_PTR(-ENXIO);
+		goto out;
+	}
+
+	if (!state->info) {
+		state->info = kmalloc(sizeof(struct uart_info), GFP_KERNEL);
+		if (state->info) {
+			memset(state->info, 0, sizeof(struct uart_info));
+			init_waitqueue_head(&state->info->open_wait);
+			init_waitqueue_head(&state->info->delta_msr_wait);
+
+			/*
+			 * Link the info into the other structures.
+			 */
+			state->port->info = state->info;
+
+			tasklet_init(&state->info->tlet, uart_tasklet_action,
+				     (unsigned long)state);
+		} else {
+			state->count--;
+			up(&state->sem);
+			state = ERR_PTR(-ENOMEM);
+		}
+	}
+
+ out:
+	up(&port_sem);
+	return state;
+}
+
+/*
+ * In 2.4.5, calls to uart_open are serialised by the BKL in
+ *   linux/fs/devices.c:chrdev_open()
+ * Note that if this fails, then uart_close() _will_ be called.
+ *
+ * In time, we want to scrap the "opening nonpresent ports"
+ * behaviour and implement an alternative way for setserial
+ * to set base addresses/ports/types.  This will allow us to
+ * get rid of a certain amount of extra tests.
+ */
+static int uart_open(struct tty_struct *tty, struct file *filp)
+{
+	struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
+	struct uart_state *state;
+	int retval, line = tty->index;
+
+	BUG_ON(!kernel_locked());
+	DPRINTK("uart_open(%d) called\n", line);
+
+	/*
+	 * tty->driver->num won't change, so we won't fail here with
+	 * tty->driver_data set to something non-NULL (and therefore
+	 * we won't get caught by uart_close()).
+	 */
+	retval = -ENODEV;
+	if (line >= tty->driver->num)
+		goto fail;
+
+	/*
+	 * We take the semaphore inside uart_get to guarantee that we won't
+	 * be re-entered while allocating the info structure, or while we
+	 * request any IRQs that the driver may need.  This also has the nice
+	 * side-effect that it delays the action of uart_hangup, so we can
+	 * guarantee that info->tty will always contain something reasonable.
+	 */
+	state = uart_get(drv, line);
+	if (IS_ERR(state)) {
+		retval = PTR_ERR(state);
+		goto fail;
+	}
+
+	/*
+	 * Once we set tty->driver_data here, we are guaranteed that
+	 * uart_close() will decrement the driver module use count.
+	 * Any failures from here onwards should not touch the count.
+	 */
+	tty->driver_data = state;
+	tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
+	tty->alt_speed = 0;
+	state->info->tty = tty;
+
+	/*
+	 * If the port is in the middle of closing, bail out now.
+	 */
+	if (tty_hung_up_p(filp)) {
+		retval = -EAGAIN;
+		state->count--;
+		up(&state->sem);
+		goto fail;
+	}
+
+	/*
+	 * Make sure the device is in D0 state.
+	 */
+	if (state->count == 1)
+		uart_change_pm(state, 0);
+
+	/*
+	 * Start up the serial port.
+	 */
+	retval = uart_startup(state, 0);
+
+	/*
+	 * If we succeeded, wait until the port is ready.
+	 */
+	if (retval == 0)
+		retval = uart_block_til_ready(filp, state);
+	up(&state->sem);
+
+	/*
+	 * If this is the first open to succeed, adjust things to suit.
+	 */
+	if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
+		state->info->flags |= UIF_NORMAL_ACTIVE;
+
+		uart_update_termios(state);
+	}
+
+ fail:
+	return retval;
+}
+
+static const char *uart_type(struct uart_port *port)
+{
+	const char *str = NULL;
+
+	if (port->ops->type)
+		str = port->ops->type(port);
+
+	if (!str)
+		str = "unknown";
+
+	return str;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static int uart_line_info(char *buf, struct uart_driver *drv, int i)
+{
+	struct uart_state *state = drv->state + i;
+	struct uart_port *port = state->port;
+	char stat_buf[32];
+	unsigned int status;
+	int ret;
+
+	if (!port)
+		return 0;
+
+	ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
+			port->line, uart_type(port),
+			port->iotype == UPIO_MEM ? "mmio:0x" : "port:",
+			port->iotype == UPIO_MEM ? port->mapbase :
+						(unsigned long) port->iobase,
+			port->irq);
+
+	if (port->type == PORT_UNKNOWN) {
+		strcat(buf, "\n");
+		return ret + 1;
+	}
+
+	if(capable(CAP_SYS_ADMIN))
+	{
+		status = port->ops->get_mctrl(port);
+
+		ret += sprintf(buf + ret, " tx:%d rx:%d",
+				port->icount.tx, port->icount.rx);
+		if (port->icount.frame)
+			ret += sprintf(buf + ret, " fe:%d",
+				port->icount.frame);
+		if (port->icount.parity)
+			ret += sprintf(buf + ret, " pe:%d",
+				port->icount.parity);
+		if (port->icount.brk)
+			ret += sprintf(buf + ret, " brk:%d",
+				port->icount.brk);
+		if (port->icount.overrun)
+			ret += sprintf(buf + ret, " oe:%d",
+				port->icount.overrun);
+	
+#define INFOBIT(bit,str) \
+	if (port->mctrl & (bit)) \
+		strncat(stat_buf, (str), sizeof(stat_buf) - \
+			strlen(stat_buf) - 2)
+#define STATBIT(bit,str) \
+	if (status & (bit)) \
+		strncat(stat_buf, (str), sizeof(stat_buf) - \
+		       strlen(stat_buf) - 2)
+
+		stat_buf[0] = '\0';
+		stat_buf[1] = '\0';
+		INFOBIT(TIOCM_RTS, "|RTS");
+		STATBIT(TIOCM_CTS, "|CTS");
+		INFOBIT(TIOCM_DTR, "|DTR");
+		STATBIT(TIOCM_DSR, "|DSR");
+		STATBIT(TIOCM_CAR, "|CD");
+		STATBIT(TIOCM_RNG, "|RI");
+		if (stat_buf[0])
+			stat_buf[0] = ' ';
+		strcat(stat_buf, "\n");
+	
+		ret += sprintf(buf + ret, stat_buf);
+	} else {
+		strcat(buf, "\n");
+		ret++;
+	}
+#undef STATBIT
+#undef INFOBIT
+	return ret;
+}
+
+static int uart_read_proc(char *page, char **start, off_t off,
+			  int count, int *eof, void *data)
+{
+	struct tty_driver *ttydrv = data;
+	struct uart_driver *drv = ttydrv->driver_state;
+	int i, len = 0, l;
+	off_t begin = 0;
+
+	len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
+			"", "", "");
+	for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
+		l = uart_line_info(page + len, drv, 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);
+}
+#endif
+
+#ifdef CONFIG_SERIAL_CORE_CONSOLE
+/*
+ *	Check whether an invalid uart number has been specified, and
+ *	if so, search for the first available port that does have
+ *	console support.
+ */
+struct uart_port * __init
+uart_get_console(struct uart_port *ports, int nr, struct console *co)
+{
+	int idx = co->index;
+
+	if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
+				     ports[idx].membase == NULL))
+		for (idx = 0; idx < nr; idx++)
+			if (ports[idx].iobase != 0 ||
+			    ports[idx].membase != NULL)
+				break;
+
+	co->index = idx;
+
+	return ports + idx;
+}
+
+/**
+ *	uart_parse_options - Parse serial port baud/parity/bits/flow contro.
+ *	@options: pointer to option string
+ *	@baud: pointer to an 'int' variable for the baud rate.
+ *	@parity: pointer to an 'int' variable for the parity.
+ *	@bits: pointer to an 'int' variable for the number of data bits.
+ *	@flow: pointer to an 'int' variable for the flow control character.
+ *
+ *	uart_parse_options decodes a string containing the serial console
+ *	options.  The format of the string is <baud><parity><bits><flow>,
+ *	eg: 115200n8r
+ */
+void __init
+uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
+{
+	char *s = options;
+
+	*baud = simple_strtoul(s, NULL, 10);
+	while (*s >= '0' && *s <= '9')
+		s++;
+	if (*s)
+		*parity = *s++;
+	if (*s)
+		*bits = *s++ - '0';
+	if (*s)
+		*flow = *s;
+}
+
+struct baud_rates {
+	unsigned int rate;
+	unsigned int cflag;
+};
+
+static struct baud_rates baud_rates[] = {
+	{ 921600, B921600 },
+	{ 460800, B460800 },
+	{ 230400, B230400 },
+	{ 115200, B115200 },
+	{  57600, B57600  },
+	{  38400, B38400  },
+	{  19200, B19200  },
+	{   9600, B9600   },
+	{   4800, B4800   },
+	{   2400, B2400   },
+	{   1200, B1200   },
+	{      0, B38400  }
+};
+
+/**
+ *	uart_set_options - setup the serial console parameters
+ *	@port: pointer to the serial ports uart_port structure
+ *	@co: console pointer
+ *	@baud: baud rate
+ *	@parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
+ *	@bits: number of data bits
+ *	@flow: flow control character - 'r' (rts)
+ */
+int __init
+uart_set_options(struct uart_port *port, struct console *co,
+		 int baud, int parity, int bits, int flow)
+{
+	struct termios termios;
+	int i;
+
+	memset(&termios, 0, sizeof(struct termios));
+
+	termios.c_cflag = CREAD | HUPCL | CLOCAL;
+
+	/*
+	 * Construct a cflag setting.
+	 */
+	for (i = 0; baud_rates[i].rate; i++)
+		if (baud_rates[i].rate <= baud)
+			break;
+
+	termios.c_cflag |= baud_rates[i].cflag;
+
+	if (bits == 7)
+		termios.c_cflag |= CS7;
+	else
+		termios.c_cflag |= CS8;
+
+	switch (parity) {
+	case 'o': case 'O':
+		termios.c_cflag |= PARODD;
+		/*fall through*/
+	case 'e': case 'E':
+		termios.c_cflag |= PARENB;
+		break;
+	}
+
+	if (flow == 'r')
+		termios.c_cflag |= CRTSCTS;
+
+	port->ops->set_termios(port, &termios, NULL);
+	co->cflag = termios.c_cflag;
+
+	return 0;
+}
+#endif /* CONFIG_SERIAL_CORE_CONSOLE */
+
+static void uart_change_pm(struct uart_state *state, int pm_state)
+{
+	struct uart_port *port = state->port;
+	if (port->ops->pm)
+		port->ops->pm(port, pm_state, state->pm_state);
+	state->pm_state = pm_state;
+}
+
+int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct uart_state *state = drv->state + port->line;
+
+	down(&state->sem);
+
+	if (state->info && state->info->flags & UIF_INITIALIZED) {
+		struct uart_ops *ops = port->ops;
+
+		spin_lock_irq(&port->lock);
+		ops->stop_tx(port, 0);
+		ops->set_mctrl(port, 0);
+		ops->stop_rx(port);
+		spin_unlock_irq(&port->lock);
+
+		/*
+		 * Wait for the transmitter to empty.
+		 */
+		while (!ops->tx_empty(port)) {
+			msleep(10);
+		}
+
+		ops->shutdown(port);
+	}
+
+	/*
+	 * Disable the console device before suspending.
+	 */
+	if (uart_console(port))
+		console_stop(port->cons);
+
+	uart_change_pm(state, 3);
+
+	up(&state->sem);
+
+	return 0;
+}
+
+int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct uart_state *state = drv->state + port->line;
+
+	down(&state->sem);
+
+	uart_change_pm(state, 0);
+
+	/*
+	 * Re-enable the console device after suspending.
+	 */
+	if (uart_console(port)) {
+		struct termios termios;
+
+		/*
+		 * First try to use the console cflag setting.
+		 */
+		memset(&termios, 0, sizeof(struct termios));
+		termios.c_cflag = port->cons->cflag;
+
+		/*
+		 * If that's unset, use the tty termios setting.
+		 */
+		if (state->info && state->info->tty && termios.c_cflag == 0)
+			termios = *state->info->tty->termios;
+
+		port->ops->set_termios(port, &termios, NULL);
+		console_start(port->cons);
+	}
+
+	if (state->info && state->info->flags & UIF_INITIALIZED) {
+		struct uart_ops *ops = port->ops;
+
+		ops->set_mctrl(port, 0);
+		ops->startup(port);
+		uart_change_speed(state, NULL);
+		spin_lock_irq(&port->lock);
+		ops->set_mctrl(port, port->mctrl);
+		ops->start_tx(port, 0);
+		spin_unlock_irq(&port->lock);
+	}
+
+	up(&state->sem);
+
+	return 0;
+}
+
+static inline void
+uart_report_port(struct uart_driver *drv, struct uart_port *port)
+{
+	printk("%s%d", drv->dev_name, port->line);
+	printk(" at ");
+	switch (port->iotype) {
+	case UPIO_PORT:
+		printk("I/O 0x%x", port->iobase);
+		break;
+	case UPIO_HUB6:
+		printk("I/O 0x%x offset 0x%x", port->iobase, port->hub6);
+		break;
+	case UPIO_MEM:
+	case UPIO_MEM32:
+		printk("MMIO 0x%lx", port->mapbase);
+		break;
+	}
+	printk(" (irq = %d) is a %s\n", port->irq, uart_type(port));
+}
+
+static void
+uart_configure_port(struct uart_driver *drv, struct uart_state *state,
+		    struct uart_port *port)
+{
+	unsigned int flags;
+
+	/*
+	 * If there isn't a port here, don't do anything further.
+	 */
+	if (!port->iobase && !port->mapbase && !port->membase)
+		return;
+
+	/*
+	 * Now do the auto configuration stuff.  Note that config_port
+	 * is expected to claim the resources and map the port for us.
+	 */
+	flags = UART_CONFIG_TYPE;
+	if (port->flags & UPF_AUTO_IRQ)
+		flags |= UART_CONFIG_IRQ;
+	if (port->flags & UPF_BOOT_AUTOCONF) {
+		port->type = PORT_UNKNOWN;
+		port->ops->config_port(port, flags);
+	}
+
+	if (port->type != PORT_UNKNOWN) {
+		unsigned long flags;
+
+		uart_report_port(drv, port);
+
+		/*
+		 * Ensure that the modem control lines are de-activated.
+		 * We probably don't need a spinlock around this, but
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+		port->ops->set_mctrl(port, 0);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		/*
+		 * Power down all ports by default, except the
+		 * console if we have one.
+		 */
+		if (!uart_console(port))
+			uart_change_pm(state, 3);
+	}
+}
+
+/*
+ * This reverses the effects of uart_configure_port, hanging up the
+ * port before removal.
+ */
+static void
+uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
+{
+	struct uart_port *port = state->port;
+	struct uart_info *info = state->info;
+
+	if (info && info->tty)
+		tty_vhangup(info->tty);
+
+	down(&state->sem);
+
+	state->info = NULL;
+
+	/*
+	 * Free the port IO and memory resources, if any.
+	 */
+	if (port->type != PORT_UNKNOWN)
+		port->ops->release_port(port);
+
+	/*
+	 * Indicate that there isn't a port here anymore.
+	 */
+	port->type = PORT_UNKNOWN;
+
+	/*
+	 * Kill the tasklet, and free resources.
+	 */
+	if (info) {
+		tasklet_kill(&info->tlet);
+		kfree(info);
+	}
+
+	up(&state->sem);
+}
+
+static struct tty_operations uart_ops = {
+	.open		= uart_open,
+	.close		= uart_close,
+	.write		= uart_write,
+	.put_char	= uart_put_char,
+	.flush_chars	= uart_flush_chars,
+	.write_room	= uart_write_room,
+	.chars_in_buffer= uart_chars_in_buffer,
+	.flush_buffer	= uart_flush_buffer,
+	.ioctl		= uart_ioctl,
+	.throttle	= uart_throttle,
+	.unthrottle	= uart_unthrottle,
+	.send_xchar	= uart_send_xchar,
+	.set_termios	= uart_set_termios,
+	.stop		= uart_stop,
+	.start		= uart_start,
+	.hangup		= uart_hangup,
+	.break_ctl	= uart_break_ctl,
+	.wait_until_sent= uart_wait_until_sent,
+#ifdef CONFIG_PROC_FS
+	.read_proc	= uart_read_proc,
+#endif
+	.tiocmget	= uart_tiocmget,
+	.tiocmset	= uart_tiocmset,
+};
+
+/**
+ *	uart_register_driver - register a driver with the uart core layer
+ *	@drv: low level driver structure
+ *
+ *	Register a uart driver with the core driver.  We in turn register
+ *	with the tty layer, and initialise the core driver per-port state.
+ *
+ *	We have a proc file in /proc/tty/driver which is named after the
+ *	normal driver.
+ *
+ *	drv->port should be NULL, and the per-port structures should be
+ *	registered using uart_add_one_port after this call has succeeded.
+ */
+int uart_register_driver(struct uart_driver *drv)
+{
+	struct tty_driver *normal = NULL;
+	int i, retval;
+
+	BUG_ON(drv->state);
+
+	/*
+	 * Maybe we should be using a slab cache for this, especially if
+	 * we have a large number of ports to handle.
+	 */
+	drv->state = kmalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
+	retval = -ENOMEM;
+	if (!drv->state)
+		goto out;
+
+	memset(drv->state, 0, sizeof(struct uart_state) * drv->nr);
+
+	normal  = alloc_tty_driver(drv->nr);
+	if (!normal)
+		goto out;
+
+	drv->tty_driver = normal;
+
+	normal->owner		= drv->owner;
+	normal->driver_name	= drv->driver_name;
+	normal->devfs_name	= drv->devfs_name;
+	normal->name		= drv->dev_name;
+	normal->major		= drv->major;
+	normal->minor_start	= drv->minor;
+	normal->type		= TTY_DRIVER_TYPE_SERIAL;
+	normal->subtype		= SERIAL_TYPE_NORMAL;
+	normal->init_termios	= tty_std_termios;
+	normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	normal->flags		= TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
+	normal->driver_state    = drv;
+	tty_set_operations(normal, &uart_ops);
+
+	/*
+	 * Initialise the UART state(s).
+	 */
+	for (i = 0; i < drv->nr; i++) {
+		struct uart_state *state = drv->state + i;
+
+		state->close_delay     = 500;	/* .5 seconds */
+		state->closing_wait    = 30000;	/* 30 seconds */
+
+		init_MUTEX(&state->sem);
+	}
+
+	retval = tty_register_driver(normal);
+ out:
+	if (retval < 0) {
+		put_tty_driver(normal);
+		kfree(drv->state);
+	}
+	return retval;
+}
+
+/**
+ *	uart_unregister_driver - remove a driver from the uart core layer
+ *	@drv: low level driver structure
+ *
+ *	Remove all references to a driver from the core driver.  The low
+ *	level driver must have removed all its ports via the
+ *	uart_remove_one_port() if it registered them with uart_add_one_port().
+ *	(ie, drv->port == NULL)
+ */
+void uart_unregister_driver(struct uart_driver *drv)
+{
+	struct tty_driver *p = drv->tty_driver;
+	tty_unregister_driver(p);
+	put_tty_driver(p);
+	kfree(drv->state);
+	drv->tty_driver = NULL;
+}
+
+struct tty_driver *uart_console_device(struct console *co, int *index)
+{
+	struct uart_driver *p = co->data;
+	*index = co->index;
+	return p->tty_driver;
+}
+
+/**
+ *	uart_add_one_port - attach a driver-defined port structure
+ *	@drv: pointer to the uart low level driver structure for this port
+ *	@port: uart port structure to use for this port.
+ *
+ *	This allows the driver to register its own uart_port structure
+ *	with the core driver.  The main purpose is to allow the low
+ *	level uart drivers to expand uart_port, rather than having yet
+ *	more levels of structures.
+ */
+int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct uart_state *state;
+	int ret = 0;
+
+	BUG_ON(in_interrupt());
+
+	if (port->line >= drv->nr)
+		return -EINVAL;
+
+	state = drv->state + port->line;
+
+	down(&port_sem);
+	if (state->port) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	state->port = port;
+
+	spin_lock_init(&port->lock);
+	port->cons = drv->cons;
+	port->info = state->info;
+
+	uart_configure_port(drv, state, port);
+
+	/*
+	 * Register the port whether it's detected or not.  This allows
+	 * setserial to be used to alter this ports parameters.
+	 */
+	tty_register_device(drv->tty_driver, port->line, port->dev);
+
+	/*
+	 * If this driver supports console, and it hasn't been
+	 * successfully registered yet, try to re-register it.
+	 * It may be that the port was not available.
+	 */
+	if (port->type != PORT_UNKNOWN &&
+	    port->cons && !(port->cons->flags & CON_ENABLED))
+		register_console(port->cons);
+
+ out:
+	up(&port_sem);
+
+	return ret;
+}
+
+/**
+ *	uart_remove_one_port - detach a driver defined port structure
+ *	@drv: pointer to the uart low level driver structure for this port
+ *	@port: uart port structure for this port
+ *
+ *	This unhooks (and hangs up) the specified port structure from the
+ *	core driver.  No further calls will be made to the low-level code
+ *	for this port.
+ */
+int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct uart_state *state = drv->state + port->line;
+
+	BUG_ON(in_interrupt());
+
+	if (state->port != port)
+		printk(KERN_ALERT "Removing wrong port: %p != %p\n",
+			state->port, port);
+
+	down(&port_sem);
+
+	/*
+	 * Remove the devices from devfs
+	 */
+	tty_unregister_device(drv->tty_driver, port->line);
+
+	uart_unconfigure_port(drv, state);
+	state->port = NULL;
+	up(&port_sem);
+
+	return 0;
+}
+
+/*
+ *	Are the two ports equivalent?
+ */
+int uart_match_port(struct uart_port *port1, struct uart_port *port2)
+{
+	if (port1->iotype != port2->iotype)
+		return 0;
+
+	switch (port1->iotype) {
+	case UPIO_PORT:
+		return (port1->iobase == port2->iobase);
+	case UPIO_HUB6:
+		return (port1->iobase == port2->iobase) &&
+		       (port1->hub6   == port2->hub6);
+	case UPIO_MEM:
+		return (port1->membase == port2->membase);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(uart_match_port);
+
+/*
+ *	Try to find an unused uart_state slot for a port.
+ */
+static struct uart_state *
+uart_find_match_or_unused(struct uart_driver *drv, struct uart_port *port)
+{
+	int i;
+
+	/*
+	 * First, find a port entry which matches.  Note: if we do
+	 * find a matching entry, and it has a non-zero use count,
+	 * then we can't register the port.
+	 */
+	for (i = 0; i < drv->nr; i++)
+		if (uart_match_port(drv->state[i].port, port))
+			return &drv->state[i];
+
+	/*
+	 * We didn't find a matching entry, so look for the first
+	 * free entry.  We look for one which hasn't been previously
+	 * used (indicated by zero iobase).
+	 */
+	for (i = 0; i < drv->nr; i++)
+		if (drv->state[i].port->type == PORT_UNKNOWN &&
+		    drv->state[i].port->iobase == 0 &&
+		    drv->state[i].count == 0)
+			return &drv->state[i];
+
+	/*
+	 * That also failed.  Last resort is to find any currently
+	 * entry which doesn't have a real port associated with it.
+	 */
+	for (i = 0; i < drv->nr; i++)
+		if (drv->state[i].port->type == PORT_UNKNOWN &&
+		    drv->state[i].count == 0)
+			return &drv->state[i];
+
+	return NULL;
+}
+
+/**
+ *	uart_register_port: register uart settings with a port
+ *	@drv: pointer to the uart low level driver structure for this port
+ *	@port: uart port structure describing the port
+ *
+ *	Register UART settings with the specified low level driver.  Detect
+ *	the type of the port if UPF_BOOT_AUTOCONF is set, and detect the
+ *	IRQ if UPF_AUTO_IRQ is set.
+ *
+ *	We try to pick the same port for the same IO base address, so that
+ *	when a modem is plugged in, unplugged and plugged back in, it gets
+ *	allocated the same port.
+ *
+ *	Returns negative error, or positive line number.
+ */
+int uart_register_port(struct uart_driver *drv, struct uart_port *port)
+{
+	struct uart_state *state;
+	int ret;
+
+	down(&port_sem);
+
+	state = uart_find_match_or_unused(drv, port);
+
+	if (state) {
+		/*
+		 * Ok, we've found a line that we can use.
+		 *
+		 * If we find a port that matches this one, and it appears
+		 * to be in-use (even if it doesn't have a type) we shouldn't
+		 * alter it underneath itself - the port may be open and
+		 * trying to do useful work.
+		 */
+		if (uart_users(state) != 0) {
+			ret = -EBUSY;
+			goto out;
+		}
+
+		/*
+		 * If the port is already initialised, don't touch it.
+		 */
+		if (state->port->type == PORT_UNKNOWN) {
+			state->port->iobase   = port->iobase;
+			state->port->membase  = port->membase;
+			state->port->irq      = port->irq;
+			state->port->uartclk  = port->uartclk;
+			state->port->fifosize = port->fifosize;
+			state->port->regshift = port->regshift;
+			state->port->iotype   = port->iotype;
+			state->port->flags    = port->flags;
+			state->port->line     = state - drv->state;
+			state->port->mapbase  = port->mapbase;
+
+			uart_configure_port(drv, state, state->port);
+		}
+
+		ret = state->port->line;
+	} else
+		ret = -ENOSPC;
+ out:
+	up(&port_sem);
+	return ret;
+}
+
+/**
+ *	uart_unregister_port - de-allocate a port
+ *	@drv: pointer to the uart low level driver structure for this port
+ *	@line: line index previously returned from uart_register_port()
+ *
+ *	Hang up the specified line associated with the low level driver,
+ *	and mark the port as unused.
+ */
+void uart_unregister_port(struct uart_driver *drv, int line)
+{
+	struct uart_state *state;
+
+	if (line < 0 || line >= drv->nr) {
+		printk(KERN_ERR "Attempt to unregister ");
+		printk("%s%d", drv->dev_name, line);
+		printk("\n");
+		return;
+	}
+
+	state = drv->state + line;
+
+	down(&port_sem);
+	uart_unconfigure_port(drv, state);
+	up(&port_sem);
+}
+
+EXPORT_SYMBOL(uart_write_wakeup);
+EXPORT_SYMBOL(uart_register_driver);
+EXPORT_SYMBOL(uart_unregister_driver);
+EXPORT_SYMBOL(uart_suspend_port);
+EXPORT_SYMBOL(uart_resume_port);
+EXPORT_SYMBOL(uart_register_port);
+EXPORT_SYMBOL(uart_unregister_port);
+EXPORT_SYMBOL(uart_add_one_port);
+EXPORT_SYMBOL(uart_remove_one_port);
+
+MODULE_DESCRIPTION("Serial driver core");
+MODULE_LICENSE("GPL");