diff options
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 2578 |
1 files changed, 2578 insertions, 0 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c new file mode 100644 index 0000000..460a72d --- /dev/null +++ b/drivers/tty/serial/serial_core.c @@ -0,0 +1,2578 @@ +/* + * linux/drivers/char/core.c + * + * Driver core for serial ports + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * + * Copyright 1999 ARM Limited + * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <linux/module.h> +#include <linux/tty.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/device.h> +#include <linux/serial.h> /* for serial_state and serial_icounter_struct */ +#include <linux/serial_core.h> +#include <linux/delay.h> +#include <linux/mutex.h> + +#include <asm/irq.h> +#include <asm/uaccess.h> + +/* + * This is used to lock changes in serial line configuration. + */ +static DEFINE_MUTEX(port_mutex); + +/* + * lockdep: port->lock is initialized in two places, but we + * want only one lock-class: + */ +static struct lock_class_key port_lock_key; + +#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) + +#ifdef CONFIG_SERIAL_CORE_CONSOLE +#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line) +#else +#define uart_console(port) (0) +#endif + +static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, + struct ktermios *old_termios); +static void __uart_wait_until_sent(struct uart_port *port, int timeout); +static void uart_change_pm(struct uart_state *state, int pm_state); + +/* + * This routine is used by the interrupt handler to schedule processing in + * the software interrupt portion of the driver. + */ +void uart_write_wakeup(struct uart_port *port) +{ + struct uart_state *state = port->state; + /* + * This means you called this function _after_ the port was + * closed. No cookie for you. + */ + BUG_ON(!state); + tasklet_schedule(&state->tlet); +} + +static void uart_stop(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port = state->uart_port; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + port->ops->stop_tx(port); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void __uart_start(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port = state->uart_port; + + if (!uart_circ_empty(&state->xmit) && state->xmit.buf && + !tty->stopped && !tty->hw_stopped) + port->ops->start_tx(port); +} + +static void uart_start(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port = state->uart_port; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + __uart_start(tty); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void uart_tasklet_action(unsigned long data) +{ + struct uart_state *state = (struct uart_state *)data; + tty_wakeup(state->port.tty); +} + +static inline void +uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) +{ + unsigned long flags; + unsigned int old; + + spin_lock_irqsave(&port->lock, flags); + old = port->mctrl; + port->mctrl = (old & ~clear) | set; + if (old != port->mctrl) + port->ops->set_mctrl(port, port->mctrl); + spin_unlock_irqrestore(&port->lock, flags); +} + +#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) +#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear) + +/* + * Startup the port. This will be called once per open. All calls + * will be serialised by the per-port mutex. + */ +static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw) +{ + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + unsigned long page; + int retval = 0; + + if (port->flags & ASYNC_INITIALIZED) + return 0; + + /* + * Set the TTY IO error marker - we will only clear this + * once we have successfully opened the port. Also set + * up the tty->alt_speed kludge + */ + set_bit(TTY_IO_ERROR, &tty->flags); + + if (uport->type == PORT_UNKNOWN) + return 0; + + /* + * Initialise and allocate the transmit and temporary + * buffer. + */ + if (!state->xmit.buf) { + /* This is protected by the per port mutex */ + page = get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + state->xmit.buf = (unsigned char *) page; + uart_circ_clear(&state->xmit); + } + + retval = uport->ops->startup(uport); + if (retval == 0) { + if (init_hw) { + /* + * Initialise the hardware port settings. + */ + uart_change_speed(tty, state, NULL); + + /* + * Setup the RTS and DTR signals once the + * port is open and ready to respond. + */ + if (tty->termios->c_cflag & CBAUD) + uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR); + } + + if (port->flags & ASYNC_CTS_FLOW) { + spin_lock_irq(&uport->lock); + if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) + tty->hw_stopped = 1; + spin_unlock_irq(&uport->lock); + } + + set_bit(ASYNCB_INITIALIZED, &port->flags); + + clear_bit(TTY_IO_ERROR, &tty->flags); + } + + if (retval && capable(CAP_SYS_ADMIN)) + retval = 0; + + return retval; +} + +/* + * This routine will shutdown a serial port; interrupts are disabled, and + * DTR is dropped if the hangup on close termio flag is on. Calls to + * uart_shutdown are serialised by the per-port semaphore. + */ +static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) +{ + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + + /* + * Set the TTY IO error marker + */ + if (tty) + set_bit(TTY_IO_ERROR, &tty->flags); + + if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) { + /* + * Turn off DTR and RTS early. + */ + if (!tty || (tty->termios->c_cflag & HUPCL)) + uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); + + /* + * clear delta_msr_wait queue to avoid mem leaks: we may free + * the irq here so the queue might never be woken up. Note + * that we won't end up waiting on delta_msr_wait again since + * any outstanding file descriptors should be pointing at + * hung_up_tty_fops now. + */ + wake_up_interruptible(&port->delta_msr_wait); + + /* + * Free the IRQ and disable the port. + */ + uport->ops->shutdown(uport); + + /* + * Ensure that the IRQ handler isn't running on another CPU. + */ + synchronize_irq(uport->irq); + } + + /* + * kill off our tasklet + */ + tasklet_kill(&state->tlet); + + /* + * Free the transmit buffer page. + */ + if (state->xmit.buf) { + free_page((unsigned long)state->xmit.buf); + state->xmit.buf = NULL; + } +} + +/** + * uart_update_timeout - update per-port FIFO timeout. + * @port: uart_port structure describing the port + * @cflag: termios cflag value + * @baud: speed of the port + * + * Set the port FIFO timeout value. The @cflag value should + * reflect the actual hardware settings. + */ +void +uart_update_timeout(struct uart_port *port, unsigned int cflag, + unsigned int baud) +{ + unsigned int bits; + + /* byte size and parity */ + switch (cflag & CSIZE) { + case CS5: + bits = 7; + break; + case CS6: + bits = 8; + break; + case CS7: + bits = 9; + break; + default: + bits = 10; + break; /* CS8 */ + } + + if (cflag & CSTOPB) + bits++; + if (cflag & PARENB) + bits++; + + /* + * The total number of bits to be transmitted in the fifo. + */ + bits = bits * port->fifosize; + + /* + * Figure the timeout to send the above number of bits. + * Add .02 seconds of slop + */ + port->timeout = (HZ * bits) / baud + HZ/50; +} + +EXPORT_SYMBOL(uart_update_timeout); + +/** + * uart_get_baud_rate - return baud rate for a particular port + * @port: uart_port structure describing the port in question. + * @termios: desired termios settings. + * @old: old termios (or NULL) + * @min: minimum acceptable baud rate + * @max: maximum acceptable baud rate + * + * Decode the termios structure into a numeric baud rate, + * taking account of the magic 38400 baud rate (with spd_* + * flags), and mapping the %B0 rate to 9600 baud. + * + * If the new baud rate is invalid, try the old termios setting. + * If it's still invalid, we try 9600 baud. + * + * Update the @termios structure to reflect the baud rate + * we're actually going to be using. Don't do this for the case + * where B0 is requested ("hang up"). + */ +unsigned int +uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, + struct ktermios *old, unsigned int min, unsigned int max) +{ + unsigned int try, baud, altbaud = 38400; + int hung_up = 0; + upf_t flags = port->flags & UPF_SPD_MASK; + + if (flags == UPF_SPD_HI) + altbaud = 57600; + else if (flags == UPF_SPD_VHI) + altbaud = 115200; + else if (flags == UPF_SPD_SHI) + altbaud = 230400; + else if (flags == UPF_SPD_WARP) + altbaud = 460800; + + for (try = 0; try < 2; try++) { + baud = tty_termios_baud_rate(termios); + + /* + * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... + * Die! Die! Die! + */ + if (baud == 38400) + baud = altbaud; + + /* + * Special case: B0 rate. + */ + if (baud == 0) { + hung_up = 1; + baud = 9600; + } + + if (baud >= min && baud <= max) + return baud; + + /* + * Oops, the quotient was zero. Try again with + * the old baud rate if possible. + */ + termios->c_cflag &= ~CBAUD; + if (old) { + baud = tty_termios_baud_rate(old); + if (!hung_up) + tty_termios_encode_baud_rate(termios, + baud, baud); + old = NULL; + continue; + } + + /* + * As a last resort, if the range cannot be met then clip to + * the nearest chip supported rate. + */ + if (!hung_up) { + if (baud <= min) + tty_termios_encode_baud_rate(termios, + min + 1, min + 1); + else + tty_termios_encode_baud_rate(termios, + max - 1, max - 1); + } + } + /* Should never happen */ + WARN_ON(1); + return 0; +} + +EXPORT_SYMBOL(uart_get_baud_rate); + +/** + * uart_get_divisor - return uart clock divisor + * @port: uart_port structure describing the port. + * @baud: desired baud rate + * + * Calculate the uart clock divisor for the port. + */ +unsigned int +uart_get_divisor(struct uart_port *port, unsigned int baud) +{ + unsigned int quot; + + /* + * Old custom speed handling. + */ + if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) + quot = port->custom_divisor; + else + quot = (port->uartclk + (8 * baud)) / (16 * baud); + + return quot; +} + +EXPORT_SYMBOL(uart_get_divisor); + +/* FIXME: Consistent locking policy */ +static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, + struct ktermios *old_termios) +{ + struct tty_port *port = &state->port; + struct uart_port *uport = state->uart_port; + struct ktermios *termios; + + /* + * If we have no tty, termios, or the port does not exist, + * then we can't set the parameters for this port. + */ + if (!tty || !tty->termios || uport->type == PORT_UNKNOWN) + return; + + termios = tty->termios; + + /* + * Set flags based on termios cflag + */ + if (termios->c_cflag & CRTSCTS) + set_bit(ASYNCB_CTS_FLOW, &port->flags); + else + clear_bit(ASYNCB_CTS_FLOW, &port->flags); + + if (termios->c_cflag & CLOCAL) + clear_bit(ASYNCB_CHECK_CD, &port->flags); + else + set_bit(ASYNCB_CHECK_CD, &port->flags); + + uport->ops->set_termios(uport, termios, old_termios); +} + +static inline int __uart_put_char(struct uart_port *port, + struct circ_buf *circ, unsigned char c) +{ + unsigned long flags; + int ret = 0; + + if (!circ->buf) + return 0; + + spin_lock_irqsave(&port->lock, flags); + if (uart_circ_chars_free(circ) != 0) { + circ->buf[circ->head] = c; + circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); + ret = 1; + } + spin_unlock_irqrestore(&port->lock, flags); + return ret; +} + +static int uart_put_char(struct tty_struct *tty, unsigned char ch) +{ + struct uart_state *state = tty->driver_data; + + return __uart_put_char(state->uart_port, &state->xmit, ch); +} + +static void uart_flush_chars(struct tty_struct *tty) +{ + uart_start(tty); +} + +static int uart_write(struct tty_struct *tty, + const unsigned char *buf, int count) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port; + struct circ_buf *circ; + unsigned long flags; + int c, ret = 0; + + /* + * This means you called this function _after_ the port was + * closed. No cookie for you. + */ + if (!state) { + WARN_ON(1); + return -EL3HLT; + } + + port = state->uart_port; + circ = &state->xmit; + + if (!circ->buf) + return 0; + + spin_lock_irqsave(&port->lock, flags); + while (1) { + c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); + if (count < c) + c = count; + if (c <= 0) + break; + memcpy(circ->buf + circ->head, buf, c); + circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); + buf += c; + count -= c; + ret += c; + } + spin_unlock_irqrestore(&port->lock, flags); + + uart_start(tty); + return ret; +} + +static int uart_write_room(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + unsigned long flags; + int ret; + + spin_lock_irqsave(&state->uart_port->lock, flags); + ret = uart_circ_chars_free(&state->xmit); + spin_unlock_irqrestore(&state->uart_port->lock, flags); + return ret; +} + +static int uart_chars_in_buffer(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + unsigned long flags; + int ret; + + spin_lock_irqsave(&state->uart_port->lock, flags); + ret = uart_circ_chars_pending(&state->xmit); + spin_unlock_irqrestore(&state->uart_port->lock, flags); + return ret; +} + +static void uart_flush_buffer(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port; + unsigned long flags; + + /* + * This means you called this function _after_ the port was + * closed. No cookie for you. + */ + if (!state) { + WARN_ON(1); + return; + } + + port = state->uart_port; + pr_debug("uart_flush_buffer(%d) called\n", tty->index); + + spin_lock_irqsave(&port->lock, flags); + uart_circ_clear(&state->xmit); + if (port->ops->flush_buffer) + port->ops->flush_buffer(port); + spin_unlock_irqrestore(&port->lock, flags); + tty_wakeup(tty); +} + +/* + * This function is used to send a high-priority XON/XOFF character to + * the device + */ +static void uart_send_xchar(struct tty_struct *tty, char ch) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port = state->uart_port; + unsigned long flags; + + if (port->ops->send_xchar) + port->ops->send_xchar(port, ch); + else { + port->x_char = ch; + if (ch) { + spin_lock_irqsave(&port->lock, flags); + port->ops->start_tx(port); + spin_unlock_irqrestore(&port->lock, flags); + } + } +} + +static void uart_throttle(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + + if (I_IXOFF(tty)) + uart_send_xchar(tty, STOP_CHAR(tty)); + + if (tty->termios->c_cflag & CRTSCTS) + uart_clear_mctrl(state->uart_port, TIOCM_RTS); +} + +static void uart_unthrottle(struct tty_struct *tty) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *port = state->uart_port; + + if (I_IXOFF(tty)) { + if (port->x_char) + port->x_char = 0; + else + uart_send_xchar(tty, START_CHAR(tty)); + } + + if (tty->termios->c_cflag & CRTSCTS) + uart_set_mctrl(port, TIOCM_RTS); +} + +static int uart_get_info(struct uart_state *state, + struct serial_struct __user *retinfo) +{ + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + struct serial_struct tmp; + + memset(&tmp, 0, sizeof(tmp)); + + /* Ensure the state we copy is consistent and no hardware changes + occur as we go */ + mutex_lock(&port->mutex); + + tmp.type = uport->type; + tmp.line = uport->line; + tmp.port = uport->iobase; + if (HIGH_BITS_OFFSET) + tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; + tmp.irq = uport->irq; + tmp.flags = uport->flags; + tmp.xmit_fifo_size = uport->fifosize; + tmp.baud_base = uport->uartclk / 16; + tmp.close_delay = port->close_delay / 10; + tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : + port->closing_wait / 10; + tmp.custom_divisor = uport->custom_divisor; + tmp.hub6 = uport->hub6; + tmp.io_type = uport->iotype; + tmp.iomem_reg_shift = uport->regshift; + tmp.iomem_base = (void *)(unsigned long)uport->mapbase; + + mutex_unlock(&port->mutex); + + if (copy_to_user(retinfo, &tmp, sizeof(*retinfo))) + return -EFAULT; + return 0; +} + +static int uart_set_info(struct tty_struct *tty, struct uart_state *state, + struct serial_struct __user *newinfo) +{ + struct serial_struct new_serial; + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + unsigned long new_port; + unsigned int change_irq, change_port, closing_wait; + unsigned int old_custom_divisor, close_delay; + upf_t old_flags, new_flags; + int retval = 0; + + if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) + return -EFAULT; + + new_port = new_serial.port; + if (HIGH_BITS_OFFSET) + new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET; + + new_serial.irq = irq_canonicalize(new_serial.irq); + close_delay = new_serial.close_delay * 10; + closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10; + + /* + * This semaphore protects port->count. It is also + * very useful to prevent opens. Also, take the + * port configuration semaphore to make sure that a + * module insertion/removal doesn't change anything + * under us. + */ + mutex_lock(&port->mutex); + + change_irq = !(uport->flags & UPF_FIXED_PORT) + && new_serial.irq != uport->irq; + + /* + * Since changing the 'type' of the port changes its resource + * allocations, we should treat type changes the same as + * IO port changes. + */ + change_port = !(uport->flags & UPF_FIXED_PORT) + && (new_port != uport->iobase || + (unsigned long)new_serial.iomem_base != uport->mapbase || + new_serial.hub6 != uport->hub6 || + new_serial.io_type != uport->iotype || + new_serial.iomem_reg_shift != uport->regshift || + new_serial.type != uport->type); + + old_flags = uport->flags; + new_flags = new_serial.flags; + old_custom_divisor = uport->custom_divisor; + + if (!capable(CAP_SYS_ADMIN)) { + retval = -EPERM; + if (change_irq || change_port || + (new_serial.baud_base != uport->uartclk / 16) || + (close_delay != port->close_delay) || + (closing_wait != port->closing_wait) || + (new_serial.xmit_fifo_size && + new_serial.xmit_fifo_size != uport->fifosize) || + (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) + goto exit; + uport->flags = ((uport->flags & ~UPF_USR_MASK) | + (new_flags & UPF_USR_MASK)); + uport->custom_divisor = new_serial.custom_divisor; + goto check_and_exit; + } + + /* + * Ask the low level driver to verify the settings. + */ + if (uport->ops->verify_port) + retval = uport->ops->verify_port(uport, &new_serial); + + if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) || + (new_serial.baud_base < 9600)) + retval = -EINVAL; + + if (retval) + goto exit; + + if (change_port || change_irq) { + retval = -EBUSY; + + /* + * Make sure that we are the sole user of this port. + */ + if (tty_port_users(port) > 1) + goto exit; + + /* + * We need to shutdown the serial port at the old + * port/type/irq combination. + */ + uart_shutdown(tty, state); + } + + if (change_port) { + unsigned long old_iobase, old_mapbase; + unsigned int old_type, old_iotype, old_hub6, old_shift; + + old_iobase = uport->iobase; + old_mapbase = uport->mapbase; + old_type = uport->type; + old_hub6 = uport->hub6; + old_iotype = uport->iotype; + old_shift = uport->regshift; + + /* + * Free and release old regions + */ + if (old_type != PORT_UNKNOWN) + uport->ops->release_port(uport); + + uport->iobase = new_port; + uport->type = new_serial.type; + uport->hub6 = new_serial.hub6; + uport->iotype = new_serial.io_type; + uport->regshift = new_serial.iomem_reg_shift; + uport->mapbase = (unsigned long)new_serial.iomem_base; + + /* + * Claim and map the new regions + */ + if (uport->type != PORT_UNKNOWN) { + retval = uport->ops->request_port(uport); + } else { + /* Always success - Jean II */ + retval = 0; + } + + /* + * If we fail to request resources for the + * new port, try to restore the old settings. + */ + if (retval && old_type != PORT_UNKNOWN) { + uport->iobase = old_iobase; + uport->type = old_type; + uport->hub6 = old_hub6; + uport->iotype = old_iotype; + uport->regshift = old_shift; + uport->mapbase = old_mapbase; + retval = uport->ops->request_port(uport); + /* + * If we failed to restore the old settings, + * we fail like this. + */ + if (retval) + uport->type = PORT_UNKNOWN; + + /* + * We failed anyway. + */ + retval = -EBUSY; + /* Added to return the correct error -Ram Gupta */ + goto exit; + } + } + + if (change_irq) + uport->irq = new_serial.irq; + if (!(uport->flags & UPF_FIXED_PORT)) + uport->uartclk = new_serial.baud_base * 16; + uport->flags = (uport->flags & ~UPF_CHANGE_MASK) | + (new_flags & UPF_CHANGE_MASK); + uport->custom_divisor = new_serial.custom_divisor; + port->close_delay = close_delay; + port->closing_wait = closing_wait; + if (new_serial.xmit_fifo_size) + uport->fifosize = new_serial.xmit_fifo_size; + if (port->tty) + port->tty->low_latency = + (uport->flags & UPF_LOW_LATENCY) ? 1 : 0; + + check_and_exit: + retval = 0; + if (uport->type == PORT_UNKNOWN) + goto exit; + if (port->flags & ASYNC_INITIALIZED) { + if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || + old_custom_divisor != uport->custom_divisor) { + /* + * If they're setting up a custom divisor or speed, + * instead of clearing it, then bitch about it. No + * need to rate-limit; it's CAP_SYS_ADMIN only. + */ + if (uport->flags & UPF_SPD_MASK) { + char buf[64]; + printk(KERN_NOTICE + "%s sets custom speed on %s. This " + "is deprecated.\n", current->comm, + tty_name(port->tty, buf)); + } + uart_change_speed(tty, state, NULL); + } + } else + retval = uart_startup(tty, state, 1); + exit: + mutex_unlock(&port->mutex); + return retval; +} + +/** + * uart_get_lsr_info - get line status register info + * @tty: tty associated with the UART + * @state: UART being queried + * @value: returned modem value + * + * Note: uart_ioctl protects us against hangups. + */ +static int uart_get_lsr_info(struct tty_struct *tty, + struct uart_state *state, unsigned int __user *value) +{ + struct uart_port *uport = state->uart_port; + unsigned int result; + + result = uport->ops->tx_empty(uport); + + /* + * If we're about to load something into the transmit + * register, we'll pretend the transmitter isn't empty to + * avoid a race condition (depending on when the transmit + * interrupt happens). + */ + if (uport->x_char || + ((uart_circ_chars_pending(&state->xmit) > 0) && + !tty->stopped && !tty->hw_stopped)) + result &= ~TIOCSER_TEMT; + + return put_user(result, value); +} + +static int uart_tiocmget(struct tty_struct *tty, struct file *file) +{ + struct uart_state *state = tty->driver_data; + struct tty_port *port = &state->port; + struct uart_port *uport = state->uart_port; + int result = -EIO; + + mutex_lock(&port->mutex); + if ((!file || !tty_hung_up_p(file)) && + !(tty->flags & (1 << TTY_IO_ERROR))) { + result = uport->mctrl; + + spin_lock_irq(&uport->lock); + result |= uport->ops->get_mctrl(uport); + spin_unlock_irq(&uport->lock); + } + mutex_unlock(&port->mutex); + + return result; +} + +static int +uart_tiocmset(struct tty_struct *tty, struct file *file, + unsigned int set, unsigned int clear) +{ + struct uart_state *state = tty->driver_data; + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + int ret = -EIO; + + mutex_lock(&port->mutex); + if ((!file || !tty_hung_up_p(file)) && + !(tty->flags & (1 << TTY_IO_ERROR))) { + uart_update_mctrl(uport, set, clear); + ret = 0; + } + mutex_unlock(&port->mutex); + return ret; +} + +static int uart_break_ctl(struct tty_struct *tty, int break_state) +{ + struct uart_state *state = tty->driver_data; + struct tty_port *port = &state->port; + struct uart_port *uport = state->uart_port; + + mutex_lock(&port->mutex); + + if (uport->type != PORT_UNKNOWN) + uport->ops->break_ctl(uport, break_state); + + mutex_unlock(&port->mutex); + return 0; +} + +static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) +{ + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + int flags, ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + /* + * Take the per-port semaphore. This prevents count from + * changing, and hence any extra opens of the port while + * we're auto-configuring. + */ + if (mutex_lock_interruptible(&port->mutex)) + return -ERESTARTSYS; + + ret = -EBUSY; + if (tty_port_users(port) == 1) { + uart_shutdown(tty, state); + + /* + * If we already have a port type configured, + * we must release its resources. + */ + if (uport->type != PORT_UNKNOWN) + uport->ops->release_port(uport); + + flags = UART_CONFIG_TYPE; + if (uport->flags & UPF_AUTO_IRQ) + flags |= UART_CONFIG_IRQ; + + /* + * This will claim the ports resources if + * a port is found. + */ + uport->ops->config_port(uport, flags); + + ret = uart_startup(tty, state, 1); + } + mutex_unlock(&port->mutex); + return ret; +} + +/* + * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change + * - mask passed in arg for lines of interest + * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) + * Caller should use TIOCGICOUNT to see which one it was + * + * FIXME: This wants extracting into a common all driver implementation + * of TIOCMWAIT using tty_port. + */ +static int +uart_wait_modem_status(struct uart_state *state, unsigned long arg) +{ + struct uart_port *uport = state->uart_port; + struct tty_port *port = &state->port; + DECLARE_WAITQUEUE(wait, current); + struct uart_icount cprev, cnow; + int ret; + + /* + * note the counters on entry + */ + spin_lock_irq(&uport->lock); + memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); + + /* + * Force modem status interrupts on + */ + uport->ops->enable_ms(uport); + spin_unlock_irq(&uport->lock); + + add_wait_queue(&port->delta_msr_wait, &wait); + for (;;) { + spin_lock_irq(&uport->lock); + memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); + spin_unlock_irq(&uport->lock); + + set_current_state(TASK_INTERRUPTIBLE); + + if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || + ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || + ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || + ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { + ret = 0; + break; + } + + schedule(); + + /* see if a signal did it */ + if (signal_pending(current)) { + ret = -ERESTARTSYS; + break; + } + + cprev = cnow; + } + + current->state = TASK_RUNNING; + remove_wait_queue(&port->delta_msr_wait, &wait); + + return ret; +} + +/* + * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) + * Return: write counters to the user passed counter struct + * NB: both 1->0 and 0->1 transitions are counted except for + * RI where only 0->1 is counted. + */ +static int uart_get_icount(struct tty_struct *tty, + struct serial_icounter_struct *icount) +{ + struct uart_state *state = tty->driver_data; + struct uart_icount cnow; + struct uart_port *uport = state->uart_port; + + spin_lock_irq(&uport->lock); + memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); + spin_unlock_irq(&uport->lock); + + icount->cts = cnow.cts; + icount->dsr = cnow.dsr; + icount->rng = cnow.rng; + icount->dcd = cnow.dcd; + icount->rx = cnow.rx; + icount->tx = cnow.tx; + icount->frame = cnow.frame; + icount->overrun = cnow.overrun; + icount->parity = cnow.parity; + icount->brk = cnow.brk; + icount->buf_overrun = cnow.buf_overrun; + + return 0; +} + +/* + * Called via sys_ioctl. We can use spin_lock_irq() here. + */ +static int +uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct uart_state *state = tty->driver_data; + struct tty_port *port = &state->port; + void __user *uarg = (void __user *)arg; + int ret = -ENOIOCTLCMD; + + + /* + * These ioctls don't rely on the hardware to be present. + */ + switch (cmd) { + case TIOCGSERIAL: + ret = uart_get_info(state, uarg); + break; + + case TIOCSSERIAL: + ret = uart_set_info(tty, state, uarg); + break; + + case TIOCSERCONFIG: + ret = uart_do_autoconfig(tty, state); + break; + + case TIOCSERGWILD: /* obsolete */ + case TIOCSERSWILD: /* obsolete */ + ret = 0; + break; + } + + if (ret != -ENOIOCTLCMD) + goto out; + + if (tty->flags & (1 << TTY_IO_ERROR)) { + ret = -EIO; + goto out; + } + + /* + * The following should only be used when hardware is present. + */ + switch (cmd) { + case TIOCMIWAIT: + ret = uart_wait_modem_status(state, arg); + break; + } + + if (ret != -ENOIOCTLCMD) + goto out; + + mutex_lock(&port->mutex); + + if (tty_hung_up_p(filp)) { + ret = -EIO; + goto out_up; + } + + /* + * All these rely on hardware being present and need to be + * protected against the tty being hung up. + */ + switch (cmd) { + case TIOCSERGETLSR: /* Get line status register */ + ret = uart_get_lsr_info(tty, state, 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) + uport->ops->set_ldisc(uport, tty->termios->c_line); +} + +static void uart_set_termios(struct tty_struct *tty, + struct ktermios *old_termios) +{ + struct uart_state *state = tty->driver_data; + unsigned long flags; + unsigned int cflag = tty->termios->c_cflag; + + + /* + * 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 + */ +#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK)) + if ((cflag ^ old_termios->c_cflag) == 0 && + tty->termios->c_ospeed == old_termios->c_ospeed && + tty->termios->c_ispeed == old_termios->c_ispeed && + RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) { + return; + } + + uart_change_speed(tty, state, old_termios); + + /* Handle transition to B0 status */ + if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) + uart_clear_mctrl(state->uart_port, 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(state->uart_port, mask); + } + + /* Handle turning off CRTSCTS */ + if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { + spin_lock_irqsave(&state->uart_port->lock, flags); + tty->hw_stopped = 0; + __uart_start(tty); + spin_unlock_irqrestore(&state->uart_port->lock, flags); + } + /* Handle turning on CRTSCTS */ + else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { + spin_lock_irqsave(&state->uart_port->lock, flags); + if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) { + tty->hw_stopped = 1; + state->uart_port->ops->stop_tx(state->uart_port); + } + spin_unlock_irqrestore(&state->uart_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->uart_port.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 tty_port *port; + struct uart_port *uport; + unsigned long flags; + + BUG_ON(!tty_locked()); + + if (!state) + return; + + uport = state->uart_port; + port = &state->port; + + pr_debug("uart_close(%d) called\n", uport->line); + + mutex_lock(&port->mutex); + spin_lock_irqsave(&port->lock, flags); + + if (tty_hung_up_p(filp)) { + spin_unlock_irqrestore(&port->lock, flags); + goto done; + } + + if ((tty->count == 1) && (port->count != 1)) { + /* + * Uh, oh. tty->count is 1, which means that the tty + * structure will be freed. port->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, " + "port->count is %d\n", port->count); + port->count = 1; + } + if (--port->count < 0) { + printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n", + tty->name, port->count); + port->count = 0; + } + if (port->count) { + spin_unlock_irqrestore(&port->lock, flags); + 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; + spin_unlock_irqrestore(&port->lock, flags); + + if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) { + /* + * hack: open-coded tty_wait_until_sent to avoid + * recursive tty_lock + */ + long timeout = msecs_to_jiffies(port->closing_wait); + if (wait_event_interruptible_timeout(tty->write_wait, + !tty_chars_in_buffer(tty), timeout) >= 0) + __uart_wait_until_sent(uport, timeout); + } + + /* + * 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(uport, uport->timeout); + } + + uart_shutdown(tty, state); + uart_flush_buffer(tty); + + tty_ldisc_flush(tty); + + tty_port_tty_set(port, NULL); + spin_lock_irqsave(&port->lock, flags); + tty->closing = 0; + + if (port->blocked_open) { + spin_unlock_irqrestore(&port->lock, flags); + if (port->close_delay) + msleep_interruptible(port->close_delay); + spin_lock_irqsave(&port->lock, flags); + } else if (!uart_console(uport)) { + spin_unlock_irqrestore(&port->lock, flags); + uart_change_pm(state, 3); + spin_lock_irqsave(&port->lock, flags); + } + + /* + * Wake up anyone trying to open this port. + */ + clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); + spin_unlock_irqrestore(&port->lock, flags); + wake_up_interruptible(&port->open_wait); + +done: + mutex_unlock(&port->mutex); +} + +static void __uart_wait_until_sent(struct uart_port *port, int timeout) +{ + 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; + } + set_current_state(TASK_RUNNING); /* might not be needed */ +} + +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; + + tty_lock(); + __uart_wait_until_sent(port, timeout); + tty_unlock(); +} + +/* + * 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; + struct tty_port *port = &state->port; + unsigned long flags; + + BUG_ON(!tty_locked()); + 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); + wake_up_interruptible(&port->open_wait); + wake_up_interruptible(&port->delta_msr_wait); + } + mutex_unlock(&port->mutex); +} + +/** + * uart_update_termios - update the terminal hw settings + * @tty: tty associated with UART + * @state: UART to update + * + * 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 tty_struct *tty, + struct uart_state *state) +{ + struct uart_port *port = state->uart_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(tty, state, NULL); + + /* + * And finally enable the RTS and DTR signals. + */ + if (tty->termios->c_cflag & CBAUD) + uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS); + } +} + +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); + uport->ops->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); + + /* + * If this is the first open to succeed, + * adjust things to suit. + */ + if (!test_and_set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags)) + uart_update_termios(port->tty, state); + } + else + uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); +} + +static struct uart_state *uart_get(struct uart_driver *drv, int line) +{ + struct uart_state *state; + struct tty_port *port; + int ret = 0; + + state = drv->state + line; + port = &state->port; + if (mutex_lock_interruptible(&port->mutex)) { + ret = -ERESTARTSYS; + goto err; + } + + port->count++; + if (!state->uart_port || state->uart_port->flags & UPF_DEAD) { + ret = -ENXIO; + goto err_unlock; + } + return state; + + err_unlock: + port->count--; + mutex_unlock(&port->mutex); + err: + return ERR_PTR(ret); +} + +/* + * calls to uart_open are serialised by the BKL in + * fs/char_dev.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; + struct tty_port *port; + int retval, line = tty->index; + + BUG_ON(!tty_locked()); + pr_debug("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 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. + */ + state = uart_get(drv, line); + if (IS_ERR(state)) { + retval = PTR_ERR(state); + goto fail; + } + port = &state->port; + + /* + * 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; + state->uart_port->state = state; + tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0; + tty->alt_speed = 0; + tty_port_tty_set(port, tty); + + /* + * If the port is in the middle of closing, bail out now. + */ + if (tty_hung_up_p(filp)) { + retval = -EAGAIN; + port->count--; + mutex_unlock(&port->mutex); + goto fail; + } + + /* + * Make sure the device is in D0 state. + */ + if (port->count == 1) + uart_change_pm(state, 0); + + /* + * 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); + +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 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; + int 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_change_pm(state, 0); + spin_lock_irq(&uport->lock); + status = uport->ops->get_mctrl(uport); + spin_unlock_irq(&uport->lock); + if (pm_state) + 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(inode)->data); +} + +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 + * @write: 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_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 +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. + */ + 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 */ + +static void uart_change_pm(struct uart_state *state, int 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}; + struct tty_struct *tty; + + mutex_lock(&port->mutex); + + /* Must be inside the mutex lock until we convert to tty_port */ + tty = port->tty; + + 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; + } + if (console_suspend_enabled || !uart_console(uport)) + uport->suspended = 1; + + if (port->flags & ASYNC_INITIALIZED) { + const struct uart_ops *ops = uport->ops; + int tries; + + if (console_suspend_enabled || !uart_console(uport)) { + 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) + printk(KERN_ERR "%s%s%s%d: Unable to drain " + "transmitter\n", + uport->dev ? dev_name(uport->dev) : "", + uport->dev ? ": " : "", + drv->dev_name, + drv->tty_driver->name_base + uport->line); + + if (console_suspend_enabled || !uart_console(uport)) + ops->shutdown(uport); + } + + /* + * Disable the console device before suspending. + */ + if (console_suspend_enabled && uart_console(uport)) + console_stop(uport->cons); + + if (console_suspend_enabled || !uart_console(uport)) + uart_change_pm(state, 3); + + 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; + } + mutex_unlock(&port->mutex); + return 0; + } + uport->suspended = 0; + + /* + * Re-enable the console device after suspending. + */ + if (console_suspend_enabled && 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 && port->tty->termios && termios.c_cflag == 0) + termios = *(port->tty->termios); + + uart_change_pm(state, 0); + uport->ops->set_termios(uport, &termios, NULL); + console_start(uport->cons); + } + + if (port->flags & ASYNC_SUSPENDED) { + const struct uart_ops *ops = uport->ops; + int ret; + + uart_change_pm(state, 0); + 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_AU: + case UPIO_TSI: + case UPIO_DWAPB: + case UPIO_DWAPB32: + 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) 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, 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, 0); + + /* + * 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, 3); + } +} + +#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'; + + 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 (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; + 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 = { + .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->owner = drv->owner; + 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; + port->close_delay = 500; /* .5 seconds */ + port->closing_wait = 30000; /* 30 seconds */ + tasklet_init(&state->tlet, uart_tasklet_action, + (unsigned long)state); + } + + retval = tty_register_driver(normal); + if (retval >= 0) + return retval; + + 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; + 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 + * @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; + + 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; + } + + state->uart_port = uport; + state->pm_state = -1; + + uport->cons = drv->cons; + uport->state = state; + + /* + * 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); + } + + uart_configure_port(drv, state, uport); + + /* + * Register the port whether it's detected or not. This allows + * setserial to be used to alter this ports parameters. + */ + tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev); + if (likely(!IS_ERR(tty_dev))) { + device_init_wakeup(tty_dev, 1); + device_set_wakeup_enable(tty_dev, 0); + } else + printk(KERN_ERR "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; + + BUG_ON(in_interrupt()); + + if (state->uart_port != uport) + printk(KERN_ALERT "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); + uport->flags |= UPF_DEAD; + mutex_unlock(&port->mutex); + + /* + * Remove the devices from the tty layer + */ + tty_unregister_device(drv->tty_driver, uport->line); + + if (port->tty) + tty_vhangup(port->tty); + + /* + * Free the port IO and memory resources, if any. + */ + if (uport->type != PORT_UNKNOWN) + uport->ops->release_port(uport); + + /* + * Indicate that there isn't a port here anymore. + */ + uport->type = PORT_UNKNOWN; + + /* + * Kill the tasklet, and free resources. + */ + tasklet_kill(&state->tlet); + + state->uart_port = NULL; + mutex_unlock(&port_mutex); + + 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: + case UPIO_MEM32: + case UPIO_AU: + case UPIO_TSI: + case UPIO_DWAPB: + case UPIO_DWAPB32: + return (port1->mapbase == port2->mapbase); + } + return 0; +} +EXPORT_SYMBOL(uart_match_port); + +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"); |