tty: move drivers/serial/ to drivers/tty/serial/

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2578 insertions, 0 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
new file mode 100644
index 000000000000..460a72d91bb7
--- /dev/null
+++ b/drivers/tty/serial/serial_core.c
@@ -0,0 +1,2578 @@
+/*
+ *  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/module.h>
+#include <linux/tty.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/device.h>
+#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
+#include <linux/serial_core.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+
+/*
+ * This is used to lock changes in serial line configuration.
+ */
+static DEFINE_MUTEX(port_mutex);
+
+/*
+ * lockdep: port->lock is initialized in two places, but we
+ *          want only one lock-class:
+ */
+static struct lock_class_key port_lock_key;
+
+#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
+
+#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 tty_struct *tty, struct uart_state *state,
+					struct ktermios *old_termios);
+static void __uart_wait_until_sent(struct uart_port *port, 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_state *state = port->state;
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	BUG_ON(!state);
+	tasklet_schedule(&state->tlet);
+}
+
+static void uart_stop(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->uart_port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->ops->stop_tx(port);
+	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->uart_port;
+
+	if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
+	    !tty->stopped && !tty->hw_stopped)
+		port->ops->start_tx(port);
+}
+
+static void uart_start(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->uart_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->port.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 mutex.
+ */
+static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
+{
+	struct uart_port *uport = state->uart_port;
+	struct tty_port *port = &state->port;
+	unsigned long page;
+	int retval = 0;
+
+	if (port->flags & ASYNC_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
+	 */
+	set_bit(TTY_IO_ERROR, &tty->flags);
+
+	if (uport->type == PORT_UNKNOWN)
+		return 0;
+
+	/*
+	 * Initialise and allocate the transmit and temporary
+	 * buffer.
+	 */
+	if (!state->xmit.buf) {
+		/* This is protected by the per port mutex */
+		page = get_zeroed_page(GFP_KERNEL);
+		if (!page)
+			return -ENOMEM;
+
+		state->xmit.buf = (unsigned char *) page;
+		uart_circ_clear(&state->xmit);
+	}
+
+	retval = uport->ops->startup(uport);
+	if (retval == 0) {
+		if (init_hw) {
+			/*
+			 * Initialise the hardware port settings.
+			 */
+			uart_change_speed(tty, state, NULL);
+
+			/*
+			 * Setup the RTS and DTR signals once the
+			 * port is open and ready to respond.
+			 */
+			if (tty->termios->c_cflag & CBAUD)
+				uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
+		}
+
+		if (port->flags & ASYNC_CTS_FLOW) {
+			spin_lock_irq(&uport->lock);
+			if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
+				tty->hw_stopped = 1;
+			spin_unlock_irq(&uport->lock);
+		}
+
+		set_bit(ASYNCB_INITIALIZED, &port->flags);
+
+		clear_bit(TTY_IO_ERROR, &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 tty_struct *tty, struct uart_state *state)
+{
+	struct uart_port *uport = state->uart_port;
+	struct tty_port *port = &state->port;
+
+	/*
+	 * Set the TTY IO error marker
+	 */
+	if (tty)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+
+	if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
+		/*
+		 * Turn off DTR and RTS early.
+		 */
+		if (!tty || (tty->termios->c_cflag & HUPCL))
+			uart_clear_mctrl(uport, 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(&port->delta_msr_wait);
+
+		/*
+		 * Free the IRQ and disable the port.
+		 */
+		uport->ops->shutdown(uport);
+
+		/*
+		 * Ensure that the IRQ handler isn't running on another CPU.
+		 */
+		synchronize_irq(uport->irq);
+	}
+
+	/*
+	 * kill off our tasklet
+	 */
+	tasklet_kill(&state->tlet);
+
+	/*
+	 * Free the transmit buffer page.
+	 */
+	if (state->xmit.buf) {
+		free_page((unsigned long)state->xmit.buf);
+		state->xmit.buf = NULL;
+	}
+}
+
+/**
+ *	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. Don't do this for the case
+ *	where B0 is requested ("hang up").
+ */
+unsigned int
+uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
+		   struct ktermios *old, unsigned int min, unsigned int max)
+{
+	unsigned int try, baud, altbaud = 38400;
+	int hung_up = 0;
+	upf_t flags = port->flags & UPF_SPD_MASK;
+
+	if (flags == UPF_SPD_HI)
+		altbaud = 57600;
+	else if (flags == UPF_SPD_VHI)
+		altbaud = 115200;
+	else if (flags == UPF_SPD_SHI)
+		altbaud = 230400;
+	else 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) {
+			hung_up = 1;
+			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) {
+			baud = tty_termios_baud_rate(old);
+			if (!hung_up)
+				tty_termios_encode_baud_rate(termios,
+								baud, baud);
+			old = NULL;
+			continue;
+		}
+
+		/*
+		 * As a last resort, if the range cannot be met then clip to
+		 * the nearest chip supported rate.
+		 */
+		if (!hung_up) {
+			if (baud <= min)
+				tty_termios_encode_baud_rate(termios,
+							min + 1, min + 1);
+			else
+				tty_termios_encode_baud_rate(termios,
+							max - 1, max - 1);
+		}
+	}
+	/* Should never happen */
+	WARN_ON(1);
+	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);
+
+/* FIXME: Consistent locking policy */
+static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
+					struct ktermios *old_termios)
+{
+	struct tty_port *port = &state->port;
+	struct uart_port *uport = state->uart_port;
+	struct ktermios *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 || uport->type == PORT_UNKNOWN)
+		return;
+
+	termios = tty->termios;
+
+	/*
+	 * Set flags based on termios cflag
+	 */
+	if (termios->c_cflag & CRTSCTS)
+		set_bit(ASYNCB_CTS_FLOW, &port->flags);
+	else
+		clear_bit(ASYNCB_CTS_FLOW, &port->flags);
+
+	if (termios->c_cflag & CLOCAL)
+		clear_bit(ASYNCB_CHECK_CD, &port->flags);
+	else
+		set_bit(ASYNCB_CHECK_CD, &port->flags);
+
+	uport->ops->set_termios(uport, termios, old_termios);
+}
+
+static inline int __uart_put_char(struct uart_port *port,
+				struct circ_buf *circ, unsigned char c)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (!circ->buf)
+		return 0;
+
+	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);
+		ret = 1;
+	}
+	spin_unlock_irqrestore(&port->lock, flags);
+	return ret;
+}
+
+static int uart_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	struct uart_state *state = tty->driver_data;
+
+	return __uart_put_char(state->uart_port, &state->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;
+	struct circ_buf *circ;
+	unsigned long flags;
+	int c, ret = 0;
+
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	if (!state) {
+		WARN_ON(1);
+		return -EL3HLT;
+	}
+
+	port = state->uart_port;
+	circ = &state->xmit;
+
+	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;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&state->uart_port->lock, flags);
+	ret = uart_circ_chars_free(&state->xmit);
+	spin_unlock_irqrestore(&state->uart_port->lock, flags);
+	return ret;
+}
+
+static int uart_chars_in_buffer(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&state->uart_port->lock, flags);
+	ret = uart_circ_chars_pending(&state->xmit);
+	spin_unlock_irqrestore(&state->uart_port->lock, flags);
+	return ret;
+}
+
+static void uart_flush_buffer(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port;
+	unsigned long flags;
+
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	if (!state) {
+		WARN_ON(1);
+		return;
+	}
+
+	port = state->uart_port;
+	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
+
+	spin_lock_irqsave(&port->lock, flags);
+	uart_circ_clear(&state->xmit);
+	if (port->ops->flush_buffer)
+		port->ops->flush_buffer(port);
+	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->uart_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);
+			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->uart_port, TIOCM_RTS);
+}
+
+static void uart_unthrottle(struct tty_struct *tty)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->uart_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 *uport = state->uart_port;
+	struct tty_port *port = &state->port;
+	struct serial_struct tmp;
+
+	memset(&tmp, 0, sizeof(tmp));
+
+	/* Ensure the state we copy is consistent and no hardware changes
+	   occur as we go */
+	mutex_lock(&port->mutex);
+
+	tmp.type	    = uport->type;
+	tmp.line	    = uport->line;
+	tmp.port	    = uport->iobase;
+	if (HIGH_BITS_OFFSET)
+		tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
+	tmp.irq		    = uport->irq;
+	tmp.flags	    = uport->flags;
+	tmp.xmit_fifo_size  = uport->fifosize;
+	tmp.baud_base	    = uport->uartclk / 16;
+	tmp.close_delay	    = port->close_delay / 10;
+	tmp.closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+				ASYNC_CLOSING_WAIT_NONE :
+				port->closing_wait / 10;
+	tmp.custom_divisor  = uport->custom_divisor;
+	tmp.hub6	    = uport->hub6;
+	tmp.io_type         = uport->iotype;
+	tmp.iomem_reg_shift = uport->regshift;
+	tmp.iomem_base      = (void *)(unsigned long)uport->mapbase;
+
+	mutex_unlock(&port->mutex);
+
+	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+		return -EFAULT;
+	return 0;
+}
+
+static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
+			 struct serial_struct __user *newinfo)
+{
+	struct serial_struct new_serial;
+	struct uart_port *uport = state->uart_port;
+	struct tty_port *port = &state->port;
+	unsigned long new_port;
+	unsigned int change_irq, change_port, closing_wait;
+	unsigned int old_custom_divisor, close_delay;
+	upf_t old_flags, new_flags;
+	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 ?
+			ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
+
+	/*
+	 * This semaphore protects port->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.
+	 */
+	mutex_lock(&port->mutex);
+
+	change_irq  = !(uport->flags & UPF_FIXED_PORT)
+		&& new_serial.irq != uport->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 = !(uport->flags & UPF_FIXED_PORT)
+		&& (new_port != uport->iobase ||
+		    (unsigned long)new_serial.iomem_base != uport->mapbase ||
+		    new_serial.hub6 != uport->hub6 ||
+		    new_serial.io_type != uport->iotype ||
+		    new_serial.iomem_reg_shift != uport->regshift ||
+		    new_serial.type != uport->type);
+
+	old_flags = uport->flags;
+	new_flags = new_serial.flags;
+	old_custom_divisor = uport->custom_divisor;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		retval = -EPERM;
+		if (change_irq || change_port ||
+		    (new_serial.baud_base != uport->uartclk / 16) ||
+		    (close_delay != port->close_delay) ||
+		    (closing_wait != port->closing_wait) ||
+		    (new_serial.xmit_fifo_size &&
+		     new_serial.xmit_fifo_size != uport->fifosize) ||
+		    (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
+			goto exit;
+		uport->flags = ((uport->flags & ~UPF_USR_MASK) |
+			       (new_flags & UPF_USR_MASK));
+		uport->custom_divisor = new_serial.custom_divisor;
+		goto check_and_exit;
+	}
+
+	/*
+	 * Ask the low level driver to verify the settings.
+	 */
+	if (uport->ops->verify_port)
+		retval = uport->ops->verify_port(uport, &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 (tty_port_users(port) > 1)
+			goto exit;
+
+		/*
+		 * We need to shutdown the serial port at the old
+		 * port/type/irq combination.
+		 */
+		uart_shutdown(tty, state);
+	}
+
+	if (change_port) {
+		unsigned long old_iobase, old_mapbase;
+		unsigned int old_type, old_iotype, old_hub6, old_shift;
+
+		old_iobase = uport->iobase;
+		old_mapbase = uport->mapbase;
+		old_type = uport->type;
+		old_hub6 = uport->hub6;
+		old_iotype = uport->iotype;
+		old_shift = uport->regshift;
+
+		/*
+		 * Free and release old regions
+		 */
+		if (old_type != PORT_UNKNOWN)
+			uport->ops->release_port(uport);
+
+		uport->iobase = new_port;
+		uport->type = new_serial.type;
+		uport->hub6 = new_serial.hub6;
+		uport->iotype = new_serial.io_type;
+		uport->regshift = new_serial.iomem_reg_shift;
+		uport->mapbase = (unsigned long)new_serial.iomem_base;
+
+		/*
+		 * Claim and map the new regions
+		 */
+		if (uport->type != PORT_UNKNOWN) {
+			retval = uport->ops->request_port(uport);
+		} 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) {
+			uport->iobase = old_iobase;
+			uport->type = old_type;
+			uport->hub6 = old_hub6;
+			uport->iotype = old_iotype;
+			uport->regshift = old_shift;
+			uport->mapbase = old_mapbase;
+			retval = uport->ops->request_port(uport);
+			/*
+			 * If we failed to restore the old settings,
+			 * we fail like this.
+			 */
+			if (retval)
+				uport->type = PORT_UNKNOWN;
+
+			/*
+			 * We failed anyway.
+			 */
+			retval = -EBUSY;
+			/* Added to return the correct error -Ram Gupta */
+			goto exit;
+		}
+	}
+
+	if (change_irq)
+		uport->irq      = new_serial.irq;
+	if (!(uport->flags & UPF_FIXED_PORT))
+		uport->uartclk  = new_serial.baud_base * 16;
+	uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
+				 (new_flags & UPF_CHANGE_MASK);
+	uport->custom_divisor   = new_serial.custom_divisor;
+	port->close_delay     = close_delay;
+	port->closing_wait    = closing_wait;
+	if (new_serial.xmit_fifo_size)
+		uport->fifosize = new_serial.xmit_fifo_size;
+	if (port->tty)
+		port->tty->low_latency =
+			(uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
+
+ check_and_exit:
+	retval = 0;
+	if (uport->type == PORT_UNKNOWN)
+		goto exit;
+	if (port->flags & ASYNC_INITIALIZED) {
+		if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
+		    old_custom_divisor != uport->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 (uport->flags & UPF_SPD_MASK) {
+				char buf[64];
+				printk(KERN_NOTICE
+				       "%s sets custom speed on %s. This "
+				       "is deprecated.\n", current->comm,
+				       tty_name(port->tty, buf));
+			}
+			uart_change_speed(tty, state, NULL);
+		}
+	} else
+		retval = uart_startup(tty, state, 1);
+ exit:
+	mutex_unlock(&port->mutex);
+	return retval;
+}
+
+/**
+ *	uart_get_lsr_info	-	get line status register info
+ *	@tty: tty associated with the UART
+ *	@state: UART being queried
+ *	@value: returned modem value
+ *
+ *	Note: uart_ioctl protects us against hangups.
+ */
+static int uart_get_lsr_info(struct tty_struct *tty,
+			struct uart_state *state, unsigned int __user *value)
+{
+	struct uart_port *uport = state->uart_port;
+	unsigned int result;
+
+	result = uport->ops->tx_empty(uport);
+
+	/*
+	 * 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 (uport->x_char ||
+	    ((uart_circ_chars_pending(&state->xmit) > 0) &&
+	     !tty->stopped && !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 tty_port *port = &state->port;
+	struct uart_port *uport = state->uart_port;
+	int result = -EIO;
+
+	mutex_lock(&port->mutex);
+	if ((!file || !tty_hung_up_p(file)) &&
+	    !(tty->flags & (1 << TTY_IO_ERROR))) {
+		result = uport->mctrl;
+
+		spin_lock_irq(&uport->lock);
+		result |= uport->ops->get_mctrl(uport);
+		spin_unlock_irq(&uport->lock);
+	}
+	mutex_unlock(&port->mutex);
+
+	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 *uport = state->uart_port;
+	struct tty_port *port = &state->port;
+	int ret = -EIO;
+
+	mutex_lock(&port->mutex);
+	if ((!file || !tty_hung_up_p(file)) &&
+	    !(tty->flags & (1 << TTY_IO_ERROR))) {
+		uart_update_mctrl(uport, set, clear);
+		ret = 0;
+	}
+	mutex_unlock(&port->mutex);
+	return ret;
+}
+
+static int uart_break_ctl(struct tty_struct *tty, int break_state)
+{
+	struct uart_state *state = tty->driver_data;
+	struct tty_port *port = &state->port;
+	struct uart_port *uport = state->uart_port;
+
+	mutex_lock(&port->mutex);
+
+	if (uport->type != PORT_UNKNOWN)
+		uport->ops->break_ctl(uport, break_state);
+
+	mutex_unlock(&port->mutex);
+	return 0;
+}
+
+static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
+{
+	struct uart_port *uport = state->uart_port;
+	struct tty_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 (mutex_lock_interruptible(&port->mutex))
+		return -ERESTARTSYS;
+
+	ret = -EBUSY;
+	if (tty_port_users(port) == 1) {
+		uart_shutdown(tty, state);
+
+		/*
+		 * If we already have a port type configured,
+		 * we must release its resources.
+		 */
+		if (uport->type != PORT_UNKNOWN)
+			uport->ops->release_port(uport);
+
+		flags = UART_CONFIG_TYPE;
+		if (uport->flags & UPF_AUTO_IRQ)
+			flags |= UART_CONFIG_IRQ;
+
+		/*
+		 * This will claim the ports resources if
+		 * a port is found.
+		 */
+		uport->ops->config_port(uport, flags);
+
+		ret = uart_startup(tty, state, 1);
+	}
+	mutex_unlock(&port->mutex);
+	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
+ *
+ * FIXME: This wants extracting into a common all driver implementation
+ * of TIOCMWAIT using tty_port.
+ */
+static int
+uart_wait_modem_status(struct uart_state *state, unsigned long arg)
+{
+	struct uart_port *uport = state->uart_port;
+	struct tty_port *port = &state->port;
+	DECLARE_WAITQUEUE(wait, current);
+	struct uart_icount cprev, cnow;
+	int ret;
+
+	/*
+	 * note the counters on entry
+	 */
+	spin_lock_irq(&uport->lock);
+	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
+
+	/*
+	 * Force modem status interrupts on
+	 */
+	uport->ops->enable_ms(uport);
+	spin_unlock_irq(&uport->lock);
+
+	add_wait_queue(&port->delta_msr_wait, &wait);
+	for (;;) {
+		spin_lock_irq(&uport->lock);
+		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
+		spin_unlock_irq(&uport->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(&port->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_icount(struct tty_struct *tty,
+			  struct serial_icounter_struct *icount)
+{
+	struct uart_state *state = tty->driver_data;
+	struct uart_icount cnow;
+	struct uart_port *uport = state->uart_port;
+
+	spin_lock_irq(&uport->lock);
+	memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
+	spin_unlock_irq(&uport->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 0;
+}
+
+/*
+ * Called via sys_ioctl.  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;
+	struct tty_port *port = &state->port;
+	void __user *uarg = (void __user *)arg;
+	int ret = -ENOIOCTLCMD;
+
+
+	/*
+	 * 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(tty, state, uarg);
+		break;
+
+	case TIOCSERCONFIG:
+		ret = uart_do_autoconfig(tty, 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;
+	}
+
+	if (ret != -ENOIOCTLCMD)
+		goto out;
+
+	mutex_lock(&port->mutex);
+
+	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_l