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-rw-r--r--drivers/serial/serial_core.c2395
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");