--- /dev/null
+/*
+ * 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/tty_flip.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/of.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)
+
+static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
+ struct ktermios *old_termios);
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
+static void uart_change_pm(struct uart_state *state,
+ enum uart_pm_state pm_state);
+
+static void uart_port_shutdown(struct tty_port *port);
+
+static int uart_dcd_enabled(struct uart_port *uport)
+{
+ return !!(uport->status & UPSTAT_DCD_ENABLE);
+}
+
+/*
+ * 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);
+ tty_wakeup(state->port.tty);
+}
+
+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_tx_stopped(port))
+ 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 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_port_startup(struct tty_struct *tty, struct uart_state *state,
+ int init_hw)
+{
+ struct uart_port *uport = state->uart_port;
+ unsigned long page;
+ int retval = 0;
+
+ if (uport->type == PORT_UNKNOWN)
+ return 1;
+
+ /*
+ * Make sure the device is in D0 state.
+ */
+ uart_change_pm(state, UART_PM_STATE_ON);
+
+ /*
+ * 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 (uart_console(uport) && uport->cons->cflag) {
+ tty->termios.c_cflag = uport->cons->cflag;
+ uport->cons->cflag = 0;
+ }
+ /*
+ * Initialise the hardware port settings.
+ */
+ uart_change_speed(tty, state, NULL);
+
+ if (init_hw) {
+ /*
+ * 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);
+ }
+ }
+
+ /*
+ * This is to allow setserial on this port. People may want to set
+ * port/irq/type and then reconfigure the port properly if it failed
+ * now.
+ */
+ if (retval && capable(CAP_SYS_ADMIN))
+ return 1;
+
+ return retval;
+}
+
+static int uart_startup(struct tty_struct *tty, struct uart_state *state,
+ int init_hw)
+{
+ struct tty_port *port = &state->port;
+ int retval;
+
+ 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.
+ */
+ set_bit(TTY_IO_ERROR, &tty->flags);
+
+ retval = uart_port_startup(tty, state, init_hw);
+ if (!retval) {
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
+ clear_bit(TTY_IO_ERROR, &tty->flags);
+ } else if (retval > 0)
+ 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 (uart_console(uport) && tty)
+ uport->cons->cflag = tty->termios.c_cflag;
+
+ if (!tty || (tty->termios.c_cflag & HUPCL))
+ uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+
+ uart_port_shutdown(port);
+ }
+
+ /*
+ * It's possible for shutdown to be called after suspend if we get
+ * a DCD drop (hangup) at just the right time. Clear suspended bit so
+ * we don't try to resume a port that has been shutdown.
+ */
+ clear_bit(ASYNCB_SUSPENDED, &port->flags);
+
+ /*
+ * 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 (try == 0 && 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 = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
+
+ return quot;
+}
+
+EXPORT_SYMBOL(uart_get_divisor);
+
+/* Caller holds port mutex */
+static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
+ struct ktermios *old_termios)
+{
+ struct uart_port *uport = state->uart_port;
+ struct ktermios *termios;
+ int hw_stopped;
+
+ /*
+ * If we have no tty, termios, or the port does not exist,
+ * then we can't set the parameters for this port.
+ */
+ if (!tty || uport->type == PORT_UNKNOWN)
+ return;
+
+ termios = &tty->termios;
+ uport->ops->set_termios(uport, termios, old_termios);
+
+ /*
+ * Set modem status enables based on termios cflag
+ */
+ spin_lock_irq(&uport->lock);
+ if (termios->c_cflag & CRTSCTS)
+ uport->status |= UPSTAT_CTS_ENABLE;
+ else
+ uport->status &= ~UPSTAT_CTS_ENABLE;
+
+ if (termios->c_cflag & CLOCAL)
+ uport->status &= ~UPSTAT_DCD_ENABLE;
+ else
+ uport->status |= UPSTAT_DCD_ENABLE;
+
+ /* reset sw-assisted CTS flow control based on (possibly) new mode */
+ hw_stopped = uport->hw_stopped;
+ uport->hw_stopped = uart_softcts_mode(uport) &&
+ !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
+ if (uport->hw_stopped) {
+ if (!hw_stopped)
+ uport->ops->stop_tx(uport);
+ } else {
+ if (hw_stopped)
+ __uart_start(tty);
+ }
+ spin_unlock_irq(&uport->lock);
+}
+
+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;
+ }
+
+ __uart_start(tty);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ 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 {
+ spin_lock_irqsave(&port->lock, flags);
+ port->x_char = ch;
+ if (ch)
+ 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;
+ struct uart_port *port = state->uart_port;
+ upstat_t mask = 0;
+
+ if (I_IXOFF(tty))
+ mask |= UPSTAT_AUTOXOFF;
+ if (tty->termios.c_cflag & CRTSCTS)
+ mask |= UPSTAT_AUTORTS;
+
+ if (port->status & mask) {
+ port->ops->throttle(port);
+ mask &= ~port->status;
+ }
+
+ if (mask & UPSTAT_AUTOXOFF)
+ uart_send_xchar(tty, STOP_CHAR(tty));
+
+ if (mask & UPSTAT_AUTORTS)
+ uart_clear_mctrl(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;
+ upstat_t mask = 0;
+
+ if (I_IXOFF(tty))
+ mask |= UPSTAT_AUTOXOFF;
+ if (tty->termios.c_cflag & CRTSCTS)
+ mask |= UPSTAT_AUTORTS;
+
+ if (port->status & mask) {
+ port->ops->unthrottle(port);
+ mask &= ~port->status;
+ }
+
+ if (mask & UPSTAT_AUTOXOFF)
+ uart_send_xchar(tty, START_CHAR(tty));
+
+ if (mask & UPSTAT_AUTORTS)
+ uart_set_mctrl(port, TIOCM_RTS);
+}
+
+static void do_uart_get_info(struct tty_port *port,
+ struct serial_struct *retinfo)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
+
+ memset(retinfo, 0, sizeof(*retinfo));
+
+ retinfo->type = uport->type;
+ retinfo->line = uport->line;
+ retinfo->port = uport->iobase;
+ if (HIGH_BITS_OFFSET)
+ retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
+ retinfo->irq = uport->irq;
+ retinfo->flags = uport->flags;
+ retinfo->xmit_fifo_size = uport->fifosize;
+ retinfo->baud_base = uport->uartclk / 16;
+ retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
+ retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+ ASYNC_CLOSING_WAIT_NONE :
+ jiffies_to_msecs(port->closing_wait) / 10;
+ retinfo->custom_divisor = uport->custom_divisor;
+ retinfo->hub6 = uport->hub6;
+ retinfo->io_type = uport->iotype;
+ retinfo->iomem_reg_shift = uport->regshift;
+ retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
+}
+
+static void uart_get_info(struct tty_port *port,
+ struct serial_struct *retinfo)
+{
+ /* Ensure the state we copy is consistent and no hardware changes
+ occur as we go */
+ mutex_lock(&port->mutex);
+ do_uart_get_info(port, retinfo);
+ mutex_unlock(&port->mutex);
+}
+
+static int uart_get_info_user(struct tty_port *port,
+ struct serial_struct __user *retinfo)
+{
+ struct serial_struct tmp;
+ uart_get_info(port, &tmp);
+
+ if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+ return -EFAULT;
+ return 0;
+}
+
+static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
+ struct uart_state *state,
+ struct serial_struct *new_info)
+{
+ struct uart_port *uport = state->uart_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;
+
+ new_port = new_info->port;
+ if (HIGH_BITS_OFFSET)
+ new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
+
+ new_info->irq = irq_canonicalize(new_info->irq);
+ close_delay = msecs_to_jiffies(new_info->close_delay * 10);
+ closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+ ASYNC_CLOSING_WAIT_NONE :
+ msecs_to_jiffies(new_info->closing_wait * 10);
+
+
+ change_irq = !(uport->flags & UPF_FIXED_PORT)
+ && new_info->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_info->iomem_base != uport->mapbase ||
+ new_info->hub6 != uport->hub6 ||
+ new_info->io_type != uport->iotype ||
+ new_info->iomem_reg_shift != uport->regshift ||
+ new_info->type != uport->type);
+
+ old_flags = uport->flags;
+ new_flags = new_info->flags;
+ old_custom_divisor = uport->custom_divisor;
+
+ if (!capable(CAP_SYS_ADMIN)) {
+ retval = -EPERM;
+ if (change_irq || change_port ||
+ (new_info->baud_base != uport->uartclk / 16) ||
+ (close_delay != port->close_delay) ||
+ (closing_wait != port->closing_wait) ||
+ (new_info->xmit_fifo_size &&
+ new_info->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_info->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_info);
+
+ if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
+ (new_info->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_info->type;
+ uport->hub6 = new_info->hub6;
+ uport->iotype = new_info->io_type;
+ uport->regshift = new_info->iomem_reg_shift;
+ uport->mapbase = (unsigned long)new_info->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) {
+ uport->iobase = old_iobase;
+ uport->type = old_type;
+ uport->hub6 = old_hub6;
+ uport->iotype = old_iotype;
+ uport->regshift = old_shift;
+ uport->mapbase = old_mapbase;
+
+ if (old_type != PORT_UNKNOWN) {
+ 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_info->irq;
+ if (!(uport->flags & UPF_FIXED_PORT))
+ uport->uartclk = new_info->baud_base * 16;
+ uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
+ (new_flags & UPF_CHANGE_MASK);
+ uport->custom_divisor = new_info->custom_divisor;
+ port->close_delay = close_delay;
+ port->closing_wait = closing_wait;
+ if (new_info->xmit_fifo_size)
+ uport->fifosize = new_info->xmit_fifo_size;
+ port->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];
+
+ dev_notice(uport->dev,
+ "%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:
+ return retval;
+}
+
+static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
+ struct serial_struct __user *newinfo)
+{
+ struct serial_struct new_serial;
+ struct tty_port *port = &state->port;
+ int retval;
+
+ if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
+ return -EFAULT;
+
+ /*
+ * 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);
+ retval = uart_set_info(tty, port, state, &new_serial);
+ 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) &&
+ !uart_tx_stopped(uport)))
+ result &= ~TIOCSER_TEMT;
+
+ return put_user(result, value);
+}
+
+static int uart_tiocmget(struct tty_struct *tty)
+{
+ 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 (!(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, 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 (!(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;
+}
+
+static void uart_enable_ms(struct uart_port *uport)
+{
+ /*
+ * Force modem status interrupts on
+ */
+ if (uport->ops->enable_ms)
+ uport->ops->enable_ms(uport);
+}
+
+/*
+ * 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));
+ uart_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;
+ }
+ __set_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;
+}
+
+static int uart_get_rs485_config(struct uart_port *port,
+ struct serial_rs485 __user *rs485)
+{
+ unsigned long flags;
+ struct serial_rs485 aux;
+
+ spin_lock_irqsave(&port->lock, flags);
+ aux = port->rs485;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ if (copy_to_user(rs485, &aux, sizeof(aux)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int uart_set_rs485_config(struct uart_port *port,
+ struct serial_rs485 __user *rs485_user)
+{
+ struct serial_rs485 rs485;
+ int ret;
+ unsigned long flags;
+
+ if (!port->rs485_config)
+ return -ENOIOCTLCMD;
+
+ if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
+ return -EFAULT;
+
+ spin_lock_irqsave(&port->lock, flags);
+ ret = port->rs485_config(port, &rs485);
+ spin_unlock_irqrestore(&port->lock, flags);
+ if (ret)
+ return ret;
+
+ if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/*
+ * Called via sys_ioctl. We can use spin_lock_irq() here.
+ */
+static int
+uart_ioctl(struct tty_struct *tty, 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_user(port, uarg);
+ break;
+
+ case TIOCSSERIAL:
+ down_write(&tty->termios_rwsem);
+ ret = uart_set_info_user(tty, state, uarg);
+ up_write(&tty->termios_rwsem);
+ break;
+
+ case TIOCSERCONFIG:
+ down_write(&tty->termios_rwsem);
+ ret = uart_do_autoconfig(tty, state);
+ up_write(&tty->termios_rwsem);
+ 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->flags & (1 << TTY_IO_ERROR)) {
+ 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(tty, state, uarg);
+ break;
+
+ case TIOCGRS485:
+ ret = uart_get_rs485_config(state->uart_port, uarg);
+ break;
+
+ case TIOCSRS485:
+ ret = uart_set_rs485_config(state->uart_port, uarg);
+ break;
+ default: {
+ struct uart_port *uport = state->uart_port;
+ if (uport->ops->ioctl)
+ ret = uport->ops->ioctl(uport, cmd, arg);
+ break;
+ }
+ }
+out_up:
+ mutex_unlock(&port->mutex);
+out:
+ return ret;
+}
+
+static void uart_set_ldisc(struct tty_struct *tty)
+{
+ struct uart_state *state = tty->driver_data;
+ struct uart_port *uport = state->uart_port;
+
+ if (uport->ops->set_ldisc) {
+ mutex_lock(&state->port.mutex);
+ uport->ops->set_ldisc(uport, &tty->termios);
+ mutex_unlock(&state->port.mutex);
+ }
+}
+
+static void uart_set_termios(struct tty_struct *tty,
+ struct ktermios *old_termios)
+{
+ struct uart_state *state = tty->driver_data;
+ struct uart_port *uport = state->uart_port;
+ unsigned int cflag = tty->termios.c_cflag;
+ unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
+ bool sw_changed = false;
+
+ /*
+ * Drivers doing software flow control also need to know
+ * about changes to these input settings.
+ */
+ if (uport->flags & UPF_SOFT_FLOW) {
+ iflag_mask |= IXANY|IXON|IXOFF;
+ sw_changed =
+ tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
+ tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
+ }
+
+ /*
+ * These are the bits that are used to setup various
+ * flags in the low level driver. We can ignore the Bfoo
+ * bits in c_cflag; c_[io]speed will always be set
+ * appropriately by set_termios() in tty_ioctl.c
+ */
+ if ((cflag ^ old_termios->c_cflag) == 0 &&
+ tty->termios.c_ospeed == old_termios->c_ospeed &&
+ tty->termios.c_ispeed == old_termios->c_ispeed &&
+ ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
+ !sw_changed) {
+ return;
+ }
+
+ mutex_lock(&state->port.mutex);
+ uart_change_speed(tty, state, old_termios);
+ mutex_unlock(&state->port.mutex);
+ /* reload cflag from termios; port driver may have overriden flags */
+ cflag = tty->termios.c_cflag;
+
+ /* Handle transition to B0 status */
+ if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
+ uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
+ /* Handle transition away from B0 status */
+ else 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(uport, mask);
+ }
+}
+
+/*
+ * Calls to uart_close() are serialised via the tty_lock in
+ * drivers/tty/tty_io.c:tty_release()
+ * drivers/tty/tty_io.c:do_tty_hangup()
+ * This runs from a workqueue and can sleep for a _short_ time only.
+ */
+static void uart_close(struct tty_struct *tty, struct file *filp)
+{
+ struct uart_state *state = tty->driver_data;
+ struct tty_port *port;
+ struct uart_port *uport;
+ unsigned long flags;
+
+ if (!state) {
+ struct uart_driver *drv = tty->driver->driver_state;
+
+ state = drv->state + tty->index;
+ port = &state->port;
+ spin_lock_irq(&port->lock);
+ --port->count;
+ spin_unlock_irq(&port->lock);
+ return;
+ }
+
+ uport = state->uart_port;
+ port = &state->port;
+
+ pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
+
+ if (!port->count || tty_port_close_start(port, tty, filp) == 0)
+ return;
+
+ /*
+ * At this point, we stop accepting input. To do this, we
+ * disable the receive line status interrupts.
+ */
+ if (port->flags & ASYNC_INITIALIZED) {
+ unsigned long flags;
+ spin_lock_irqsave(&uport->lock, flags);
+ uport->ops->stop_rx(uport);
+ spin_unlock_irqrestore(&uport->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, uport->timeout);
+ }
+
+ mutex_lock(&port->mutex);
+ uart_shutdown(tty, state);
+ tty_port_tty_set(port, NULL);
+ tty->closing = 0;
+ spin_lock_irqsave(&port->lock, flags);
+
+ if (port->blocked_open) {
+ spin_unlock_irqrestore(&port->lock, flags);
+ if (port->close_delay)
+ msleep_interruptible(jiffies_to_msecs(port->close_delay));
+ spin_lock_irqsave(&port->lock, flags);
+ } else if (!uart_console(uport)) {
+ spin_unlock_irqrestore(&port->lock, flags);
+ uart_change_pm(state, UART_PM_STATE_OFF);
+ spin_lock_irqsave(&port->lock, flags);
+ }
+
+ /*
+ * Wake up anyone trying to open this port.
+ */
+ clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+ clear_bit(ASYNCB_CLOSING, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
+ wake_up_interruptible(&port->open_wait);
+ wake_up_interruptible(&port->close_wait);
+
+ mutex_unlock(&port->mutex);
+
+ tty_ldisc_flush(tty);
+}
+
+static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ struct uart_state *state = tty->driver_data;
+ struct uart_port *port = state->uart_port;
+ unsigned long char_time, expire;
+
+ 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;
+
+ pr_debug("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;
+ }
+}
+
+/*
+ * Calls to uart_hangup() are serialised by the tty_lock in
+ * drivers/tty/tty_io.c:do_tty_hangup()
+ * This runs from a workqueue and can sleep for a _short_ time only.
+ */
+static void uart_hangup(struct tty_struct *tty)
+{
+ struct uart_state *state = tty->driver_data;
+ struct tty_port *port = &state->port;
+ unsigned long flags;
+
+ pr_debug("uart_hangup(%d)\n", state->uart_port->line);
+
+ mutex_lock(&port->mutex);
+ if (port->flags & ASYNC_NORMAL_ACTIVE) {
+ uart_flush_buffer(tty);
+ uart_shutdown(tty, state);
+ spin_lock_irqsave(&port->lock, flags);
+ port->count = 0;
+ clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
+ tty_port_tty_set(port, NULL);
+ if (!uart_console(state->uart_port))
+ uart_change_pm(state, UART_PM_STATE_OFF);
+ wake_up_interruptible(&port->open_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
+ }
+ mutex_unlock(&port->mutex);
+}
+
+static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+ return 0;
+}
+
+static void uart_port_shutdown(struct tty_port *port)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
+
+ /*
+ * 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);
+}
+
+static int uart_carrier_raised(struct tty_port *port)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
+ int mctrl;
+ spin_lock_irq(&uport->lock);
+ uart_enable_ms(uport);
+ mctrl = uport->ops->get_mctrl(uport);
+ spin_unlock_irq(&uport->lock);
+ if (mctrl & TIOCM_CAR)
+ return 1;
+ return 0;
+}
+
+static void uart_dtr_rts(struct tty_port *port, int onoff)
+{
+ struct uart_state *state = container_of(port, struct uart_state, port);
+ struct uart_port *uport = state->uart_port;
+
+ if (onoff)
+ uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+ else
+ uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+}
+
+/*
+ * Calls to uart_open are serialised by the tty_lock in
+ * drivers/tty/tty_io.c:tty_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;
+ int retval, line = tty->index;
+ struct uart_state *state = drv->state + line;
+ struct tty_port *port = &state->port;
+
+ pr_debug("uart_open(%d) called\n", line);
+
+ spin_lock_irq(&port->lock);
+ ++port->count;
+ spin_unlock_irq(&port->lock);
+
+ /*
+ * We take the semaphore here to guarantee that we won't be re-entered
+ * while allocating the state 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
+ * state->port.tty will always contain something reasonable.
+ */
+ if (mutex_lock_interruptible(&port->mutex)) {
+ retval = -ERESTARTSYS;
+ goto end;
+ }
+
+ if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
+ retval = -ENXIO;
+ goto err_unlock;
+ }
+
+ tty->driver_data = state;
+ state->uart_port->state = state;
+ state->port.low_latency =
+ (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
+ tty_port_tty_set(port, tty);
+
+ /*
+ * Start up the serial port.
+ */
+ retval = uart_startup(tty, state, 0);
+
+ /*
+ * If we succeeded, wait until the port is ready.
+ */
+ mutex_unlock(&port->mutex);
+ if (retval == 0)
+ retval = tty_port_block_til_ready(port, tty, filp);
+
+end:
+ return retval;
+err_unlock:
+ mutex_unlock(&port->mutex);
+ goto end;
+}
+
+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 void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
+{
+ struct uart_state *state = drv->state + i;
+ struct tty_port *port = &state->port;
+ enum uart_pm_state pm_state;
+ struct uart_port *uport = state->uart_port;
+ char stat_buf[32];
+ unsigned int status;
+ int mmio;
+
+ if (!uport)
+ return;
+
+ mmio = uport->iotype >= UPIO_MEM;
+ seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
+ uport->line, uart_type(uport),
+ mmio ? "mmio:0x" : "port:",
+ mmio ? (unsigned long long)uport->mapbase
+ : (unsigned long long)uport->iobase,
+ uport->irq);
+
+ if (uport->type == PORT_UNKNOWN) {
+ seq_putc(m, '\n');
+ return;
+ }
+
+ if (capable(CAP_SYS_ADMIN)) {
+ mutex_lock(&port->mutex);
+ pm_state = state->pm_state;
+ if (pm_state != UART_PM_STATE_ON)
+ uart_change_pm(state, UART_PM_STATE_ON);
+ spin_lock_irq(&uport->lock);
+ status = uport->ops->get_mctrl(uport);
+ spin_unlock_irq(&uport->lock);
+ if (pm_state != UART_PM_STATE_ON)
+ uart_change_pm(state, pm_state);
+ mutex_unlock(&port->mutex);
+
+ seq_printf(m, " tx:%d rx:%d",
+ uport->icount.tx, uport->icount.rx);
+ if (uport->icount.frame)
+ seq_printf(m, " fe:%d",
+ uport->icount.frame);
+ if (uport->icount.parity)
+ seq_printf(m, " pe:%d",
+ uport->icount.parity);
+ if (uport->icount.brk)
+ seq_printf(m, " brk:%d",
+ uport->icount.brk);
+ if (uport->icount.overrun)
+ seq_printf(m, " oe:%d",
+ uport->icount.overrun);
+
+#define INFOBIT(bit, str) \
+ if (uport->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] = ' ';
+
+ seq_puts(m, stat_buf);
+ }
+ seq_putc(m, '\n');
+#undef STATBIT
+#undef INFOBIT
+}
+
+static int uart_proc_show(struct seq_file *m, void *v)
+{
+ struct tty_driver *ttydrv = m->private;
+ struct uart_driver *drv = ttydrv->driver_state;
+ int i;
+
+ seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
+ "", "", "");
+ for (i = 0; i < drv->nr; i++)
+ uart_line_info(m, drv, i);
+ return 0;
+}
+
+static int uart_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, uart_proc_show, PDE_DATA(inode));
+}
+
+static const struct file_operations uart_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = uart_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif
+
+#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
+/**
+ * uart_console_write - write a console message to a serial port
+ * @port: the port to write the message
+ * @s: array of characters
+ * @count: number of characters in string to write
+ * @putchar: function to write character to port
+ */
+void uart_console_write(struct uart_port *port, const char *s,
+ unsigned int count,
+ void (*putchar)(struct uart_port *, int))
+{
+ unsigned int i;
+
+ for (i = 0; i < count; i++, s++) {
+ if (*s == '\n')
+ putchar(port, '\r');
+ putchar(port, *s);
+ }
+}
+EXPORT_SYMBOL_GPL(uart_console_write);
+
+/*
+ * 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_earlycon - Parse earlycon options
+ * @p: ptr to 2nd field (ie., just beyond '<name>,')
+ * @iotype: ptr for decoded iotype (out)
+ * @addr: ptr for decoded mapbase/iobase (out)
+ * @options: ptr for <options> field; NULL if not present (out)
+ *
+ * Decodes earlycon kernel command line parameters of the form
+ * earlycon=<name>,io|mmio|mmio32,<addr>,<options>
+ * console=<name>,io|mmio|mmio32,<addr>,<options>
+ *
+ * The optional form
+ * earlycon=<name>,0x<addr>,<options>
+ * console=<name>,0x<addr>,<options>
+ * is also accepted; the returned @iotype will be UPIO_MEM.
+ *
+ * Returns 0 on success or -EINVAL on failure
+ */
+int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
+ char **options)
+{
+ if (strncmp(p, "mmio,", 5) == 0) {
+ *iotype = UPIO_MEM;
+ p += 5;
+ } else if (strncmp(p, "mmio32,", 7) == 0) {
+ *iotype = UPIO_MEM32;
+ p += 7;
+ } else if (strncmp(p, "io,", 3) == 0) {
+ *iotype = UPIO_PORT;
+ p += 3;
+ } else if (strncmp(p, "0x", 2) == 0) {
+ *iotype = UPIO_MEM;
+ } else {
+ return -EINVAL;
+ }
+
+ *addr = simple_strtoul(p, NULL, 0);
+ p = strchr(p, ',');
+ if (p)
+ p++;
+
+ *options = p;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(uart_parse_earlycon);
+
+/**
+ * uart_parse_options - Parse serial port baud/parity/bits/flow control.
+ * @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
+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;
+}
+EXPORT_SYMBOL_GPL(uart_parse_options);
+
+struct baud_rates {
+ unsigned int rate;
+ unsigned int cflag;
+};
+
+static const 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
+uart_set_options(struct uart_port *port, struct console *co,
+ int baud, int parity, int bits, int flow)
+{
+ struct ktermios termios;
+ static struct ktermios dummy;
+ int i;
+
+ /*
+ * Ensure that the serial console lock is initialised
+ * early.
+ * If this port is a console, then the spinlock is already
+ * initialised.
+ */
+ if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
+ spin_lock_init(&port->lock);
+ lockdep_set_class(&port->lock, &port_lock_key);
+ }
+
+ memset(&termios, 0, sizeof(struct ktermios));
+
+ 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;
+
+ /*
+ * some uarts on other side don't support no flow control.
+ * So we set * DTR in host uart to make them happy
+ */
+ port->mctrl |= TIOCM_DTR;
+
+ port->ops->set_termios(port, &termios, &dummy);
+ /*
+ * Allow the setting of the UART parameters with a NULL console
+ * too:
+ */
+ if (co)
+ co->cflag = termios.c_cflag;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(uart_set_options);
+#endif /* CONFIG_SERIAL_CORE_CONSOLE */
+
+/**
+ * uart_change_pm - set power state of the port
+ *
+ * @state: port descriptor
+ * @pm_state: new state
+ *
+ * Locking: port->mutex has to be held
+ */
+static void uart_change_pm(struct uart_state *state,
+ enum uart_pm_state pm_state)
+{
+ struct uart_port *port = state->uart_port;
+
+ if (state->pm_state != pm_state) {
+ if (port->ops->pm)
+ port->ops->pm(port, pm_state, state->pm_state);
+ state->pm_state = pm_state;
+ }
+}
+
+struct uart_match {
+ struct uart_port *port;
+ struct uart_driver *driver;
+};
+
+static int serial_match_port(struct device *dev, void *data)
+{
+ struct uart_match *match = data;
+ struct tty_driver *tty_drv = match->driver->tty_driver;
+ dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
+ match->port->line;
+
+ return dev->devt == devt; /* Actually, only one tty per port */
+}
+
+int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
+{
+ struct uart_state *state = drv->state + uport->line;
+ struct tty_port *port = &state->port;
+ struct device *tty_dev;
+ struct uart_match match = {uport, drv};
+
+ mutex_lock(&port->mutex);
+
+ tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+ if (device_may_wakeup(tty_dev)) {
+ if (!enable_irq_wake(uport->irq))
+ uport->irq_wake = 1;
+ put_device(tty_dev);
+ mutex_unlock(&port->mutex);
+ return 0;
+ }
+ put_device(tty_dev);
+
+ /* Nothing to do if the console is not suspending */
+ if (!console_suspend_enabled && uart_console(uport))
+ goto unlock;
+
+ uport->suspended = 1;
+
+ if (port->flags & ASYNC_INITIALIZED) {
+ const struct uart_ops *ops = uport->ops;
+ int tries;
+
+ set_bit(ASYNCB_SUSPENDED, &port->flags);
+ clear_bit(ASYNCB_INITIALIZED, &port->flags);
+
+ spin_lock_irq(&uport->lock);
+ ops->stop_tx(uport);
+ ops->set_mctrl(uport, 0);
+ ops->stop_rx(uport);
+ spin_unlock_irq(&uport->lock);
+
+ /*
+ * Wait for the transmitter to empty.
+ */
+ for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
+ msleep(10);
+ if (!tries)
+ dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
+ drv->dev_name,
+ drv->tty_driver->name_base + uport->line);
+
+ ops->shutdown(uport);
+ }
+
+ /*
+ * Disable the console device before suspending.
+ */
+ if (uart_console(uport))
+ console_stop(uport->cons);
+
+ uart_change_pm(state, UART_PM_STATE_OFF);
+unlock:
+ mutex_unlock(&port->mutex);
+
+ return 0;
+}
+
+int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
+{
+ struct uart_state *state = drv->state + uport->line;
+ struct tty_port *port = &state->port;
+ struct device *tty_dev;
+ struct uart_match match = {uport, drv};
+ struct ktermios termios;
+
+ mutex_lock(&port->mutex);
+
+ tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+ if (!uport->suspended && device_may_wakeup(tty_dev)) {
+ if (uport->irq_wake) {
+ disable_irq_wake(uport->irq);
+ uport->irq_wake = 0;
+ }
+ put_device(tty_dev);
+ mutex_unlock(&port->mutex);
+ return 0;
+ }
+ put_device(tty_dev);
+ uport->suspended = 0;
+
+ /*
+ * Re-enable the console device after suspending.
+ */
+ if (uart_console(uport)) {
+ /*
+ * First try to use the console cflag setting.
+ */
+ memset(&termios, 0, sizeof(struct ktermios));
+ termios.c_cflag = uport->cons->cflag;
+
+ /*
+ * If that's unset, use the tty termios setting.
+ */
+ if (port->tty && termios.c_cflag == 0)
+ termios = port->tty->termios;
+
+ if (console_suspend_enabled)
+ uart_change_pm(state, UART_PM_STATE_ON);
+ uport->ops->set_termios(uport, &termios, NULL);
+ if (console_suspend_enabled)
+ console_start(uport->cons);
+ }
+
+ if (port->flags & ASYNC_SUSPENDED) {
+ const struct uart_ops *ops = uport->ops;
+ int ret;
+
+ uart_change_pm(state, UART_PM_STATE_ON);
+ spin_lock_irq(&uport->lock);
+ ops->set_mctrl(uport, 0);
+ spin_unlock_irq(&uport->lock);
+ if (console_suspend_enabled || !uart_console(uport)) {
+ /* Protected by port mutex for now */
+ struct tty_struct *tty = port->tty;
+ ret = ops->startup(uport);
+ if (ret == 0) {
+ if (tty)
+ uart_change_speed(tty, state, NULL);
+ spin_lock_irq(&uport->lock);
+ ops->set_mctrl(uport, uport->mctrl);
+ ops->start_tx(uport);
+ spin_unlock_irq(&uport->lock);
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
+ } else {
+ /*
+ * Failed to resume - maybe hardware went away?
+ * Clear the "initialized" flag so we won't try
+ * to call the low level drivers shutdown method.
+ */
+ uart_shutdown(tty, state);
+ }
+ }
+
+ clear_bit(ASYNCB_SUSPENDED, &port->flags);
+ }
+
+ mutex_unlock(&port->mutex);
+
+ return 0;
+}
+
+static inline void
+uart_report_port(struct uart_driver *drv, struct uart_port *port)
+{
+ char address[64];
+
+ switch (port->iotype) {
+ case UPIO_PORT:
+ snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
+ break;
+ case UPIO_HUB6:
+ snprintf(address, sizeof(address),
+ "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
+ break;
+ case UPIO_MEM:
+ case UPIO_MEM32:
+ case UPIO_MEM32BE:
+ case UPIO_AU:
+ case UPIO_TSI:
+ snprintf(address, sizeof(address),
+ "MMIO 0x%llx", (unsigned long long)port->mapbase);
+ break;
+ default:
+ strlcpy(address, "*unknown*", sizeof(address));
+ break;
+ }
+
+ printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
+ port->dev ? dev_name(port->dev) : "",
+ port->dev ? ": " : "",
+ drv->dev_name,
+ drv->tty_driver->name_base + port->line,
+ address, port->irq, port->uartclk / 16, 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 = 0;
+ if (port->flags & UPF_AUTO_IRQ)
+ flags |= UART_CONFIG_IRQ;
+ if (port->flags & UPF_BOOT_AUTOCONF) {
+ if (!(port->flags & UPF_FIXED_TYPE)) {
+ port->type = PORT_UNKNOWN;
+ flags |= UART_CONFIG_TYPE;
+ }
+ port->ops->config_port(port, flags);
+ }
+
+ if (port->type != PORT_UNKNOWN) {
+ unsigned long flags;
+
+ uart_report_port(drv, port);
+
+ /* Power up port for set_mctrl() */
+ uart_change_pm(state, UART_PM_STATE_ON);
+
+ /*
+ * Ensure that the modem control lines are de-activated.
+ * keep the DTR setting that is set in uart_set_options()
+ * We probably don't need a spinlock around this, but
+ */
+ spin_lock_irqsave(&port->lock, flags);
+ port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ /*
+ * 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->cons && !(port->cons->flags & CON_ENABLED))
+ register_console(port->cons);
+
+ /*
+ * Power down all ports by default, except the
+ * console if we have one.
+ */
+ if (!uart_console(port))
+ uart_change_pm(state, UART_PM_STATE_OFF);
+ }
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static int uart_poll_init(struct tty_driver *driver, int line, char *options)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+ int baud = 9600;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+ int ret;
+
+ if (!state || !state->uart_port)
+ return -1;
+
+ port = state->uart_port;
+ if (!(port->ops->poll_get_char && port->ops->poll_put_char))
+ return -1;
+
+ if (port->ops->poll_init) {
+ struct tty_port *tport = &state->port;
+
+ ret = 0;
+ mutex_lock(&tport->mutex);
+ /*
+ * We don't set ASYNCB_INITIALIZED as we only initialized the
+ * hw, e.g. state->xmit is still uninitialized.
+ */
+ if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
+ ret = port->ops->poll_init(port);
+ mutex_unlock(&tport->mutex);
+ if (ret)
+ return ret;
+ }
+
+ if (options) {
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ return uart_set_options(port, NULL, baud, parity, bits, flow);
+ }
+
+ return 0;
+}
+
+static int uart_poll_get_char(struct tty_driver *driver, int line)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+
+ if (!state || !state->uart_port)
+ return -1;
+
+ port = state->uart_port;
+ return port->ops->poll_get_char(port);
+}
+
+static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+
+ if (!state || !state->uart_port)
+ return;
+
+ port = state->uart_port;
+
+ if (ch == '\n')
+ port->ops->poll_put_char(port, '\r');
+ port->ops->poll_put_char(port, ch);
+}
+#endif
+
+static const 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,
+ .set_ldisc = uart_set_ldisc,
+ .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
+ .proc_fops = &uart_proc_fops,
+#endif
+ .tiocmget = uart_tiocmget,
+ .tiocmset = uart_tiocmset,
+ .get_icount = uart_get_icount,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_init = uart_poll_init,
+ .poll_get_char = uart_poll_get_char,
+ .poll_put_char = uart_poll_put_char,
+#endif
+};
+
+static const struct tty_port_operations uart_port_ops = {
+ .activate = uart_port_activate,
+ .shutdown = uart_port_shutdown,
+ .carrier_raised = uart_carrier_raised,
+ .dtr_rts = uart_dtr_rts,
+};
+
+/**
+ * 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;
+ 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 = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
+ if (!drv->state)
+ goto out;
+
+ normal = alloc_tty_driver(drv->nr);
+ if (!normal)
+ goto out_kfree;
+
+ drv->tty_driver = normal;
+
+ normal->driver_name = drv->driver_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->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
+ normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+ 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;
+ struct tty_port *port = &state->port;
+
+ tty_port_init(port);
+ port->ops = &uart_port_ops;
+ }
+
+ retval = tty_register_driver(normal);
+ if (retval >= 0)
+ return retval;
+
+ for (i = 0; i < drv->nr; i++)
+ tty_port_destroy(&drv->state[i].port);
+ put_tty_driver(normal);
+out_kfree:
+ kfree(drv->state);
+out:
+ return -ENOMEM;
+}
+
+/**
+ * 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;
+ unsigned int i;
+
+ tty_unregister_driver(p);
+ put_tty_driver(p);
+ for (i = 0; i < drv->nr; i++)
+ tty_port_destroy(&drv->state[i].port);
+ kfree(drv->state);
+ drv->state = NULL;
+ 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;
+}
+
+static ssize_t uart_get_attr_uartclk(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
+}
+
+static ssize_t uart_get_attr_type(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
+}
+static ssize_t uart_get_attr_line(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
+}
+
+static ssize_t uart_get_attr_port(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+ unsigned long ioaddr;
+
+ uart_get_info(port, &tmp);
+ ioaddr = tmp.port;
+ if (HIGH_BITS_OFFSET)
+ ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
+ return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
+}
+
+static ssize_t uart_get_attr_irq(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
+}
+
+static ssize_t uart_get_attr_flags(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
+}
+
+static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
+}
+
+
+static ssize_t uart_get_attr_close_delay(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
+}
+
+
+static ssize_t uart_get_attr_closing_wait(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
+}
+
+static ssize_t uart_get_attr_custom_divisor(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
+}
+
+static ssize_t uart_get_attr_io_type(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
+}
+
+static ssize_t uart_get_attr_iomem_base(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
+}
+
+static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct serial_struct tmp;
+ struct tty_port *port = dev_get_drvdata(dev);
+
+ uart_get_info(port, &tmp);
+ return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
+}
+
+static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
+static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
+static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
+static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
+static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
+static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
+static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
+static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
+static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
+static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
+static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
+static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
+static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
+
+static struct attribute *tty_dev_attrs[] = {
+ &dev_attr_type.attr,
+ &dev_attr_line.attr,
+ &dev_attr_port.attr,
+ &dev_attr_irq.attr,
+ &dev_attr_flags.attr,
+ &dev_attr_xmit_fifo_size.attr,
+ &dev_attr_uartclk.attr,
+ &dev_attr_close_delay.attr,
+ &dev_attr_closing_wait.attr,
+ &dev_attr_custom_divisor.attr,
+ &dev_attr_io_type.attr,
+ &dev_attr_iomem_base.attr,
+ &dev_attr_iomem_reg_shift.attr,
+ NULL,
+ };
+
+static const struct attribute_group tty_dev_attr_group = {
+ .attrs = tty_dev_attrs,
+ };
+
+/**
+ * uart_add_one_port - attach a driver-defined port structure
+ * @drv: pointer to the uart low level driver structure for this port
+ * @uport: 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 *uport)
+{
+ struct uart_state *state;
+ struct tty_port *port;
+ int ret = 0;
+ struct device *tty_dev;
+ int num_groups;
+
+ BUG_ON(in_interrupt());
+
+ if (uport->line >= drv->nr)
+ return -EINVAL;
+
+ state = drv->state + uport->line;
+ port = &state->port;
+
+ mutex_lock(&port_mutex);
+ mutex_lock(&port->mutex);
+ if (state->uart_port) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Link the port to the driver state table and vice versa */
+ state->uart_port = uport;
+ uport->state = state;
+
+ state->pm_state = UART_PM_STATE_UNDEFINED;
+ uport->cons = drv->cons;
+ uport->minor = drv->tty_driver->minor_start + uport->line;
+
+ /*
+ * If this port is a console, then the spinlock is already
+ * initialised.
+ */
+ if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
+ spin_lock_init(&uport->lock);
+ lockdep_set_class(&uport->lock, &port_lock_key);
+ }
+ if (uport->cons && uport->dev)
+ of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
+
+ uart_configure_port(drv, state, uport);
+
+ num_groups = 2;
+ if (uport->attr_group)
+ num_groups++;
+
+ uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
+ GFP_KERNEL);
+ if (!uport->tty_groups) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ uport->tty_groups[0] = &tty_dev_attr_group;
+ if (uport->attr_group)
+ uport->tty_groups[1] = uport->attr_group;
+
+ /*
+ * Register the port whether it's detected or not. This allows
+ * setserial to be used to alter this port's parameters.
+ */
+ tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
+ uport->line, uport->dev, port, uport->tty_groups);
+ if (likely(!IS_ERR(tty_dev))) {
+ device_set_wakeup_capable(tty_dev, 1);
+ } else {
+ dev_err(uport->dev, "Cannot register tty device on line %d\n",
+ uport->line);
+ }
+
+ /*
+ * Ensure UPF_DEAD is not set.
+ */
+ uport->flags &= ~UPF_DEAD;
+
+ out:
+ mutex_unlock(&port->mutex);
+ mutex_unlock(&port_mutex);
+
+ return ret;
+}
+
+/**
+ * uart_remove_one_port - detach a driver defined port structure
+ * @drv: pointer to the uart low level driver structure for this port
+ * @uport: 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 *uport)
+{
+ struct uart_state *state = drv->state + uport->line;
+ struct tty_port *port = &state->port;
+ struct tty_struct *tty;
+ int ret = 0;
+
+ BUG_ON(in_interrupt());
+
+ if (state->uart_port != uport)
+ dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
+ state->uart_port, uport);
+
+ mutex_lock(&port_mutex);
+
+ /*
+ * Mark the port "dead" - this prevents any opens from
+ * succeeding while we shut down the port.
+ */
+ mutex_lock(&port->mutex);
+ if (!state->uart_port) {
+ mutex_unlock(&port->mutex);
+ ret = -EINVAL;
+ goto out;
+ }
+ uport->flags |= UPF_DEAD;
+ mutex_unlock(&port->mutex);
+
+ /*
+ * Remove the devices from the tty layer
+ */
+ tty_unregister_device(drv->tty_driver, uport->line);
+
+ tty = tty_port_tty_get(port);
+ if (tty) {
+ tty_vhangup(port->tty);
+ tty_kref_put(tty);
+ }
+
+ /*
+ * If the port is used as a console, unregister it
+ */
+ if (uart_console(uport))
+ unregister_console(uport->cons);
+
+ /*
+ * Free the port IO and memory resources, if any.
+ */
+ if (uport->type != PORT_UNKNOWN)
+ uport->ops->release_port(uport);
+ kfree(uport->tty_groups);
+
+ /*
+ * Indicate that there isn't a port here anymore.
+ */
+ uport->type = PORT_UNKNOWN;
+
+ state->uart_port = NULL;
+out:
+ mutex_unlock(&port_mutex);
+
+ return ret;
+}
+
+/*
+ * 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:
+ case UPIO_MEM32:
+ case UPIO_MEM32BE:
+ case UPIO_AU:
+ case UPIO_TSI:
+ return (port1->mapbase == port2->mapbase);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(uart_match_port);
+
+/**
+ * uart_handle_dcd_change - handle a change of carrier detect state
+ * @uport: uart_port structure for the open port
+ * @status: new carrier detect status, nonzero if active
+ *
+ * Caller must hold uport->lock
+ */
+void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
+{
+ struct tty_port *port = &uport->state->port;
+ struct tty_struct *tty = port->tty;
+ struct tty_ldisc *ld;
+
+ lockdep_assert_held_once(&uport->lock);
+
+ if (tty) {
+ ld = tty_ldisc_ref(tty);
+ if (ld) {
+ if (ld->ops->dcd_change)
+ ld->ops->dcd_change(tty, status);
+ tty_ldisc_deref(ld);
+ }
+ }
+
+ uport->icount.dcd++;
+
+ if (uart_dcd_enabled(uport)) {
+ if (status)
+ wake_up_interruptible(&port->open_wait);
+ else if (tty)
+ tty_hangup(tty);
+ }
+}
+EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
+
+/**
+ * uart_handle_cts_change - handle a change of clear-to-send state
+ * @uport: uart_port structure for the open port
+ * @status: new clear to send status, nonzero if active
+ *
+ * Caller must hold uport->lock
+ */
+void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
+{
+ lockdep_assert_held_once(&uport->lock);
+
+ uport->icount.cts++;
+
+ if (uart_softcts_mode(uport)) {
+ if (uport->hw_stopped) {
+ if (status) {
+ uport->hw_stopped = 0;
+ uport->ops->start_tx(uport);
+ uart_write_wakeup(uport);
+ }
+ } else {
+ if (!status) {
+ uport->hw_stopped = 1;
+ uport->ops->stop_tx(uport);
+ }
+ }
+
+ }
+}
+EXPORT_SYMBOL_GPL(uart_handle_cts_change);
+
+/**
+ * uart_insert_char - push a char to the uart layer
+ *
+ * User is responsible to call tty_flip_buffer_push when they are done with
+ * insertion.
+ *
+ * @port: corresponding port
+ * @status: state of the serial port RX buffer (LSR for 8250)
+ * @overrun: mask of overrun bits in @status
+ * @ch: character to push
+ * @flag: flag for the character (see TTY_NORMAL and friends)
+ */
+void uart_insert_char(struct uart_port *port, unsigned int status,
+ unsigned int overrun, unsigned int ch, unsigned int flag)
+{
+ struct tty_port *tport = &port->state->port;
+
+ if ((status & port->ignore_status_mask & ~overrun) == 0)
+ if (tty_insert_flip_char(tport, ch, flag) == 0)
+ ++port->icount.buf_overrun;
+
+ /*
+ * Overrun is special. Since it's reported immediately,
+ * it doesn't affect the current character.
+ */
+ if (status & ~port->ignore_status_mask & overrun)
+ if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
+ ++port->icount.buf_overrun;
+}
+EXPORT_SYMBOL_GPL(uart_insert_char);
+
+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_add_one_port);
+EXPORT_SYMBOL(uart_remove_one_port);
+
+MODULE_DESCRIPTION("Serial driver core");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff