2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/proc_fs.h>
29 #include <linux/seq_file.h>
30 #include <linux/device.h>
31 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
32 #include <linux/serial_core.h>
33 #include <linux/delay.h>
34 #include <linux/mutex.h>
37 #include <asm/uaccess.h>
40 * This is used to lock changes in serial line configuration.
42 static DEFINE_MUTEX(port_mutex);
45 * lockdep: port->lock is initialized in two places, but we
46 * want only one lock-class:
48 static struct lock_class_key port_lock_key;
50 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52 #ifdef CONFIG_SERIAL_CORE_CONSOLE
53 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
55 #define uart_console(port) (0)
58 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
59 struct ktermios *old_termios);
60 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
61 static void uart_change_pm(struct uart_state *state, int pm_state);
64 * This routine is used by the interrupt handler to schedule processing in
65 * the software interrupt portion of the driver.
67 void uart_write_wakeup(struct uart_port *port)
69 struct uart_state *state = port->state;
71 * This means you called this function _after_ the port was
72 * closed. No cookie for you.
75 tty_wakeup(state->port.tty);
78 static void uart_stop(struct tty_struct *tty)
80 struct uart_state *state = tty->driver_data;
81 struct uart_port *port = state->uart_port;
84 spin_lock_irqsave(&port->lock, flags);
85 port->ops->stop_tx(port);
86 spin_unlock_irqrestore(&port->lock, flags);
89 static void __uart_start(struct tty_struct *tty)
91 struct uart_state *state = tty->driver_data;
92 struct uart_port *port = state->uart_port;
94 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
95 !tty->stopped && !tty->hw_stopped)
96 port->ops->start_tx(port);
99 static void uart_start(struct tty_struct *tty)
101 struct uart_state *state = tty->driver_data;
102 struct uart_port *port = state->uart_port;
105 spin_lock_irqsave(&port->lock, flags);
107 spin_unlock_irqrestore(&port->lock, flags);
111 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
116 spin_lock_irqsave(&port->lock, flags);
118 port->mctrl = (old & ~clear) | set;
119 if (old != port->mctrl)
120 port->ops->set_mctrl(port, port->mctrl);
121 spin_unlock_irqrestore(&port->lock, flags);
124 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
125 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
128 * Startup the port. This will be called once per open. All calls
129 * will be serialised by the per-port mutex.
131 static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
133 struct uart_port *uport = state->uart_port;
134 struct tty_port *port = &state->port;
138 if (port->flags & ASYNC_INITIALIZED)
142 * Set the TTY IO error marker - we will only clear this
143 * once we have successfully opened the port. Also set
144 * up the tty->alt_speed kludge
146 set_bit(TTY_IO_ERROR, &tty->flags);
148 if (uport->type == PORT_UNKNOWN)
152 * Initialise and allocate the transmit and temporary
155 if (!state->xmit.buf) {
156 /* This is protected by the per port mutex */
157 page = get_zeroed_page(GFP_KERNEL);
161 state->xmit.buf = (unsigned char *) page;
162 uart_circ_clear(&state->xmit);
165 retval = uport->ops->startup(uport);
167 if (uart_console(uport) && uport->cons->cflag) {
168 tty->termios->c_cflag = uport->cons->cflag;
169 uport->cons->cflag = 0;
172 * Initialise the hardware port settings.
174 uart_change_speed(tty, state, NULL);
178 * Setup the RTS and DTR signals once the
179 * port is open and ready to respond.
181 if (tty->termios->c_cflag & CBAUD)
182 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
185 if (port->flags & ASYNC_CTS_FLOW) {
186 spin_lock_irq(&uport->lock);
187 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
189 spin_unlock_irq(&uport->lock);
192 set_bit(ASYNCB_INITIALIZED, &port->flags);
194 clear_bit(TTY_IO_ERROR, &tty->flags);
197 if (retval && capable(CAP_SYS_ADMIN))
204 * This routine will shutdown a serial port; interrupts are disabled, and
205 * DTR is dropped if the hangup on close termio flag is on. Calls to
206 * uart_shutdown are serialised by the per-port semaphore.
208 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
210 struct uart_port *uport = state->uart_port;
211 struct tty_port *port = &state->port;
214 * Set the TTY IO error marker
217 set_bit(TTY_IO_ERROR, &tty->flags);
219 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
221 * Turn off DTR and RTS early.
223 if (!tty || (tty->termios->c_cflag & HUPCL))
224 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
227 * clear delta_msr_wait queue to avoid mem leaks: we may free
228 * the irq here so the queue might never be woken up. Note
229 * that we won't end up waiting on delta_msr_wait again since
230 * any outstanding file descriptors should be pointing at
231 * hung_up_tty_fops now.
233 wake_up_interruptible(&port->delta_msr_wait);
236 * Free the IRQ and disable the port.
238 uport->ops->shutdown(uport);
241 * Ensure that the IRQ handler isn't running on another CPU.
243 synchronize_irq(uport->irq);
247 * Free the transmit buffer page.
249 if (state->xmit.buf) {
250 free_page((unsigned long)state->xmit.buf);
251 state->xmit.buf = NULL;
256 * uart_update_timeout - update per-port FIFO timeout.
257 * @port: uart_port structure describing the port
258 * @cflag: termios cflag value
259 * @baud: speed of the port
261 * Set the port FIFO timeout value. The @cflag value should
262 * reflect the actual hardware settings.
265 uart_update_timeout(struct uart_port *port, unsigned int cflag,
270 /* byte size and parity */
271 switch (cflag & CSIZE) {
292 * The total number of bits to be transmitted in the fifo.
294 bits = bits * port->fifosize;
297 * Figure the timeout to send the above number of bits.
298 * Add .02 seconds of slop
300 port->timeout = (HZ * bits) / baud + HZ/50;
303 EXPORT_SYMBOL(uart_update_timeout);
306 * uart_get_baud_rate - return baud rate for a particular port
307 * @port: uart_port structure describing the port in question.
308 * @termios: desired termios settings.
309 * @old: old termios (or NULL)
310 * @min: minimum acceptable baud rate
311 * @max: maximum acceptable baud rate
313 * Decode the termios structure into a numeric baud rate,
314 * taking account of the magic 38400 baud rate (with spd_*
315 * flags), and mapping the %B0 rate to 9600 baud.
317 * If the new baud rate is invalid, try the old termios setting.
318 * If it's still invalid, we try 9600 baud.
320 * Update the @termios structure to reflect the baud rate
321 * we're actually going to be using. Don't do this for the case
322 * where B0 is requested ("hang up").
325 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
326 struct ktermios *old, unsigned int min, unsigned int max)
328 unsigned int try, baud, altbaud = 38400;
330 upf_t flags = port->flags & UPF_SPD_MASK;
332 if (flags == UPF_SPD_HI)
334 else if (flags == UPF_SPD_VHI)
336 else if (flags == UPF_SPD_SHI)
338 else if (flags == UPF_SPD_WARP)
341 for (try = 0; try < 2; try++) {
342 baud = tty_termios_baud_rate(termios);
345 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
352 * Special case: B0 rate.
359 if (baud >= min && baud <= max)
363 * Oops, the quotient was zero. Try again with
364 * the old baud rate if possible.
366 termios->c_cflag &= ~CBAUD;
368 baud = tty_termios_baud_rate(old);
370 tty_termios_encode_baud_rate(termios,
377 * As a last resort, if the range cannot be met then clip to
378 * the nearest chip supported rate.
382 tty_termios_encode_baud_rate(termios,
385 tty_termios_encode_baud_rate(termios,
389 /* Should never happen */
394 EXPORT_SYMBOL(uart_get_baud_rate);
397 * uart_get_divisor - return uart clock divisor
398 * @port: uart_port structure describing the port.
399 * @baud: desired baud rate
401 * Calculate the uart clock divisor for the port.
404 uart_get_divisor(struct uart_port *port, unsigned int baud)
409 * Old custom speed handling.
411 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
412 quot = port->custom_divisor;
414 quot = (port->uartclk + (8 * baud)) / (16 * baud);
419 EXPORT_SYMBOL(uart_get_divisor);
421 /* FIXME: Consistent locking policy */
422 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
423 struct ktermios *old_termios)
425 struct tty_port *port = &state->port;
426 struct uart_port *uport = state->uart_port;
427 struct ktermios *termios;
430 * If we have no tty, termios, or the port does not exist,
431 * then we can't set the parameters for this port.
433 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
436 termios = tty->termios;
439 * Set flags based on termios cflag
441 if (termios->c_cflag & CRTSCTS)
442 set_bit(ASYNCB_CTS_FLOW, &port->flags);
444 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
446 if (termios->c_cflag & CLOCAL)
447 clear_bit(ASYNCB_CHECK_CD, &port->flags);
449 set_bit(ASYNCB_CHECK_CD, &port->flags);
451 uport->ops->set_termios(uport, termios, old_termios);
454 static inline int __uart_put_char(struct uart_port *port,
455 struct circ_buf *circ, unsigned char c)
463 spin_lock_irqsave(&port->lock, flags);
464 if (uart_circ_chars_free(circ) != 0) {
465 circ->buf[circ->head] = c;
466 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
469 spin_unlock_irqrestore(&port->lock, flags);
473 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
475 struct uart_state *state = tty->driver_data;
477 return __uart_put_char(state->uart_port, &state->xmit, ch);
480 static void uart_flush_chars(struct tty_struct *tty)
485 static int uart_write(struct tty_struct *tty,
486 const unsigned char *buf, int count)
488 struct uart_state *state = tty->driver_data;
489 struct uart_port *port;
490 struct circ_buf *circ;
495 * This means you called this function _after_ the port was
496 * closed. No cookie for you.
503 port = state->uart_port;
509 spin_lock_irqsave(&port->lock, flags);
511 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
516 memcpy(circ->buf + circ->head, buf, c);
517 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
522 spin_unlock_irqrestore(&port->lock, flags);
528 static int uart_write_room(struct tty_struct *tty)
530 struct uart_state *state = tty->driver_data;
534 spin_lock_irqsave(&state->uart_port->lock, flags);
535 ret = uart_circ_chars_free(&state->xmit);
536 spin_unlock_irqrestore(&state->uart_port->lock, flags);
540 static int uart_chars_in_buffer(struct tty_struct *tty)
542 struct uart_state *state = tty->driver_data;
546 spin_lock_irqsave(&state->uart_port->lock, flags);
547 ret = uart_circ_chars_pending(&state->xmit);
548 spin_unlock_irqrestore(&state->uart_port->lock, flags);
552 static void uart_flush_buffer(struct tty_struct *tty)
554 struct uart_state *state = tty->driver_data;
555 struct uart_port *port;
559 * This means you called this function _after_ the port was
560 * closed. No cookie for you.
567 port = state->uart_port;
568 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
570 spin_lock_irqsave(&port->lock, flags);
571 uart_circ_clear(&state->xmit);
572 if (port->ops->flush_buffer)
573 port->ops->flush_buffer(port);
574 spin_unlock_irqrestore(&port->lock, flags);
579 * This function is used to send a high-priority XON/XOFF character to
582 static void uart_send_xchar(struct tty_struct *tty, char ch)
584 struct uart_state *state = tty->driver_data;
585 struct uart_port *port = state->uart_port;
588 if (port->ops->send_xchar)
589 port->ops->send_xchar(port, ch);
593 spin_lock_irqsave(&port->lock, flags);
594 port->ops->start_tx(port);
595 spin_unlock_irqrestore(&port->lock, flags);
600 static void uart_throttle(struct tty_struct *tty)
602 struct uart_state *state = tty->driver_data;
605 uart_send_xchar(tty, STOP_CHAR(tty));
607 if (tty->termios->c_cflag & CRTSCTS)
608 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
611 static void uart_unthrottle(struct tty_struct *tty)
613 struct uart_state *state = tty->driver_data;
614 struct uart_port *port = state->uart_port;
620 uart_send_xchar(tty, START_CHAR(tty));
623 if (tty->termios->c_cflag & CRTSCTS)
624 uart_set_mctrl(port, TIOCM_RTS);
627 static int uart_get_info(struct uart_state *state,
628 struct serial_struct __user *retinfo)
630 struct uart_port *uport = state->uart_port;
631 struct tty_port *port = &state->port;
632 struct serial_struct tmp;
634 memset(&tmp, 0, sizeof(tmp));
636 /* Ensure the state we copy is consistent and no hardware changes
638 mutex_lock(&port->mutex);
640 tmp.type = uport->type;
641 tmp.line = uport->line;
642 tmp.port = uport->iobase;
643 if (HIGH_BITS_OFFSET)
644 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
645 tmp.irq = uport->irq;
646 tmp.flags = uport->flags;
647 tmp.xmit_fifo_size = uport->fifosize;
648 tmp.baud_base = uport->uartclk / 16;
649 tmp.close_delay = port->close_delay / 10;
650 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
651 ASYNC_CLOSING_WAIT_NONE :
652 port->closing_wait / 10;
653 tmp.custom_divisor = uport->custom_divisor;
654 tmp.hub6 = uport->hub6;
655 tmp.io_type = uport->iotype;
656 tmp.iomem_reg_shift = uport->regshift;
657 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
659 mutex_unlock(&port->mutex);
661 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
666 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
667 struct serial_struct __user *newinfo)
669 struct serial_struct new_serial;
670 struct uart_port *uport = state->uart_port;
671 struct tty_port *port = &state->port;
672 unsigned long new_port;
673 unsigned int change_irq, change_port, closing_wait;
674 unsigned int old_custom_divisor, close_delay;
675 upf_t old_flags, new_flags;
678 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
681 new_port = new_serial.port;
682 if (HIGH_BITS_OFFSET)
683 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
685 new_serial.irq = irq_canonicalize(new_serial.irq);
686 close_delay = new_serial.close_delay * 10;
687 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
688 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
691 * This semaphore protects port->count. It is also
692 * very useful to prevent opens. Also, take the
693 * port configuration semaphore to make sure that a
694 * module insertion/removal doesn't change anything
697 mutex_lock(&port->mutex);
699 change_irq = !(uport->flags & UPF_FIXED_PORT)
700 && new_serial.irq != uport->irq;
703 * Since changing the 'type' of the port changes its resource
704 * allocations, we should treat type changes the same as
707 change_port = !(uport->flags & UPF_FIXED_PORT)
708 && (new_port != uport->iobase ||
709 (unsigned long)new_serial.iomem_base != uport->mapbase ||
710 new_serial.hub6 != uport->hub6 ||
711 new_serial.io_type != uport->iotype ||
712 new_serial.iomem_reg_shift != uport->regshift ||
713 new_serial.type != uport->type);
715 old_flags = uport->flags;
716 new_flags = new_serial.flags;
717 old_custom_divisor = uport->custom_divisor;
719 if (!capable(CAP_SYS_ADMIN)) {
721 if (change_irq || change_port ||
722 (new_serial.baud_base != uport->uartclk / 16) ||
723 (close_delay != port->close_delay) ||
724 (closing_wait != port->closing_wait) ||
725 (new_serial.xmit_fifo_size &&
726 new_serial.xmit_fifo_size != uport->fifosize) ||
727 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
729 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
730 (new_flags & UPF_USR_MASK));
731 uport->custom_divisor = new_serial.custom_divisor;
736 * Ask the low level driver to verify the settings.
738 if (uport->ops->verify_port)
739 retval = uport->ops->verify_port(uport, &new_serial);
741 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
742 (new_serial.baud_base < 9600))
748 if (change_port || change_irq) {
752 * Make sure that we are the sole user of this port.
754 if (tty_port_users(port) > 1)
758 * We need to shutdown the serial port at the old
759 * port/type/irq combination.
761 uart_shutdown(tty, state);
765 unsigned long old_iobase, old_mapbase;
766 unsigned int old_type, old_iotype, old_hub6, old_shift;
768 old_iobase = uport->iobase;
769 old_mapbase = uport->mapbase;
770 old_type = uport->type;
771 old_hub6 = uport->hub6;
772 old_iotype = uport->iotype;
773 old_shift = uport->regshift;
776 * Free and release old regions
778 if (old_type != PORT_UNKNOWN)
779 uport->ops->release_port(uport);
781 uport->iobase = new_port;
782 uport->type = new_serial.type;
783 uport->hub6 = new_serial.hub6;
784 uport->iotype = new_serial.io_type;
785 uport->regshift = new_serial.iomem_reg_shift;
786 uport->mapbase = (unsigned long)new_serial.iomem_base;
789 * Claim and map the new regions
791 if (uport->type != PORT_UNKNOWN) {
792 retval = uport->ops->request_port(uport);
794 /* Always success - Jean II */
799 * If we fail to request resources for the
800 * new port, try to restore the old settings.
802 if (retval && old_type != PORT_UNKNOWN) {
803 uport->iobase = old_iobase;
804 uport->type = old_type;
805 uport->hub6 = old_hub6;
806 uport->iotype = old_iotype;
807 uport->regshift = old_shift;
808 uport->mapbase = old_mapbase;
809 retval = uport->ops->request_port(uport);
811 * If we failed to restore the old settings,
815 uport->type = PORT_UNKNOWN;
821 /* Added to return the correct error -Ram Gupta */
827 uport->irq = new_serial.irq;
828 if (!(uport->flags & UPF_FIXED_PORT))
829 uport->uartclk = new_serial.baud_base * 16;
830 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
831 (new_flags & UPF_CHANGE_MASK);
832 uport->custom_divisor = new_serial.custom_divisor;
833 port->close_delay = close_delay;
834 port->closing_wait = closing_wait;
835 if (new_serial.xmit_fifo_size)
836 uport->fifosize = new_serial.xmit_fifo_size;
838 port->tty->low_latency =
839 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
843 if (uport->type == PORT_UNKNOWN)
845 if (port->flags & ASYNC_INITIALIZED) {
846 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
847 old_custom_divisor != uport->custom_divisor) {
849 * If they're setting up a custom divisor or speed,
850 * instead of clearing it, then bitch about it. No
851 * need to rate-limit; it's CAP_SYS_ADMIN only.
853 if (uport->flags & UPF_SPD_MASK) {
856 "%s sets custom speed on %s. This "
857 "is deprecated.\n", current->comm,
858 tty_name(port->tty, buf));
860 uart_change_speed(tty, state, NULL);
863 retval = uart_startup(tty, state, 1);
865 mutex_unlock(&port->mutex);
870 * uart_get_lsr_info - get line status register info
871 * @tty: tty associated with the UART
872 * @state: UART being queried
873 * @value: returned modem value
875 * Note: uart_ioctl protects us against hangups.
877 static int uart_get_lsr_info(struct tty_struct *tty,
878 struct uart_state *state, unsigned int __user *value)
880 struct uart_port *uport = state->uart_port;
883 result = uport->ops->tx_empty(uport);
886 * If we're about to load something into the transmit
887 * register, we'll pretend the transmitter isn't empty to
888 * avoid a race condition (depending on when the transmit
889 * interrupt happens).
892 ((uart_circ_chars_pending(&state->xmit) > 0) &&
893 !tty->stopped && !tty->hw_stopped))
894 result &= ~TIOCSER_TEMT;
896 return put_user(result, value);
899 static int uart_tiocmget(struct tty_struct *tty)
901 struct uart_state *state = tty->driver_data;
902 struct tty_port *port = &state->port;
903 struct uart_port *uport = state->uart_port;
906 mutex_lock(&port->mutex);
907 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
908 result = uport->mctrl;
909 spin_lock_irq(&uport->lock);
910 result |= uport->ops->get_mctrl(uport);
911 spin_unlock_irq(&uport->lock);
913 mutex_unlock(&port->mutex);
919 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
921 struct uart_state *state = tty->driver_data;
922 struct uart_port *uport = state->uart_port;
923 struct tty_port *port = &state->port;
926 mutex_lock(&port->mutex);
927 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
928 uart_update_mctrl(uport, set, clear);
931 mutex_unlock(&port->mutex);
935 static int uart_break_ctl(struct tty_struct *tty, int break_state)
937 struct uart_state *state = tty->driver_data;
938 struct tty_port *port = &state->port;
939 struct uart_port *uport = state->uart_port;
941 mutex_lock(&port->mutex);
943 if (uport->type != PORT_UNKNOWN)
944 uport->ops->break_ctl(uport, break_state);
946 mutex_unlock(&port->mutex);
950 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
952 struct uart_port *uport = state->uart_port;
953 struct tty_port *port = &state->port;
956 if (!capable(CAP_SYS_ADMIN))
960 * Take the per-port semaphore. This prevents count from
961 * changing, and hence any extra opens of the port while
962 * we're auto-configuring.
964 if (mutex_lock_interruptible(&port->mutex))
968 if (tty_port_users(port) == 1) {
969 uart_shutdown(tty, state);
972 * If we already have a port type configured,
973 * we must release its resources.
975 if (uport->type != PORT_UNKNOWN)
976 uport->ops->release_port(uport);
978 flags = UART_CONFIG_TYPE;
979 if (uport->flags & UPF_AUTO_IRQ)
980 flags |= UART_CONFIG_IRQ;
983 * This will claim the ports resources if
986 uport->ops->config_port(uport, flags);
988 ret = uart_startup(tty, state, 1);
990 mutex_unlock(&port->mutex);
995 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
996 * - mask passed in arg for lines of interest
997 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
998 * Caller should use TIOCGICOUNT to see which one it was
1000 * FIXME: This wants extracting into a common all driver implementation
1001 * of TIOCMWAIT using tty_port.
1004 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1006 struct uart_port *uport = state->uart_port;
1007 struct tty_port *port = &state->port;
1008 DECLARE_WAITQUEUE(wait, current);
1009 struct uart_icount cprev, cnow;
1013 * note the counters on entry
1015 spin_lock_irq(&uport->lock);
1016 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1019 * Force modem status interrupts on
1021 uport->ops->enable_ms(uport);
1022 spin_unlock_irq(&uport->lock);
1024 add_wait_queue(&port->delta_msr_wait, &wait);
1026 spin_lock_irq(&uport->lock);
1027 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1028 spin_unlock_irq(&uport->lock);
1030 set_current_state(TASK_INTERRUPTIBLE);
1032 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1033 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1034 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1035 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1042 /* see if a signal did it */
1043 if (signal_pending(current)) {
1051 current->state = TASK_RUNNING;
1052 remove_wait_queue(&port->delta_msr_wait, &wait);
1058 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1059 * Return: write counters to the user passed counter struct
1060 * NB: both 1->0 and 0->1 transitions are counted except for
1061 * RI where only 0->1 is counted.
1063 static int uart_get_icount(struct tty_struct *tty,
1064 struct serial_icounter_struct *icount)
1066 struct uart_state *state = tty->driver_data;
1067 struct uart_icount cnow;
1068 struct uart_port *uport = state->uart_port;
1070 spin_lock_irq(&uport->lock);
1071 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1072 spin_unlock_irq(&uport->lock);
1074 icount->cts = cnow.cts;
1075 icount->dsr = cnow.dsr;
1076 icount->rng = cnow.rng;
1077 icount->dcd = cnow.dcd;
1078 icount->rx = cnow.rx;
1079 icount->tx = cnow.tx;
1080 icount->frame = cnow.frame;
1081 icount->overrun = cnow.overrun;
1082 icount->parity = cnow.parity;
1083 icount->brk = cnow.brk;
1084 icount->buf_overrun = cnow.buf_overrun;
1090 * Called via sys_ioctl. We can use spin_lock_irq() here.
1093 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1096 struct uart_state *state = tty->driver_data;
1097 struct tty_port *port = &state->port;
1098 void __user *uarg = (void __user *)arg;
1099 int ret = -ENOIOCTLCMD;
1103 * These ioctls don't rely on the hardware to be present.
1107 ret = uart_get_info(state, uarg);
1111 ret = uart_set_info(tty, state, uarg);
1115 ret = uart_do_autoconfig(tty, state);
1118 case TIOCSERGWILD: /* obsolete */
1119 case TIOCSERSWILD: /* obsolete */
1124 if (ret != -ENOIOCTLCMD)
1127 if (tty->flags & (1 << TTY_IO_ERROR)) {
1133 * The following should only be used when hardware is present.
1137 ret = uart_wait_modem_status(state, arg);
1141 if (ret != -ENOIOCTLCMD)
1144 mutex_lock(&port->mutex);
1146 if (tty->flags & (1 << TTY_IO_ERROR)) {
1152 * All these rely on hardware being present and need to be
1153 * protected against the tty being hung up.
1156 case TIOCSERGETLSR: /* Get line status register */
1157 ret = uart_get_lsr_info(tty, state, uarg);
1161 struct uart_port *uport = state->uart_port;
1162 if (uport->ops->ioctl)
1163 ret = uport->ops->ioctl(uport, cmd, arg);
1168 mutex_unlock(&port->mutex);
1173 static void uart_set_ldisc(struct tty_struct *tty)
1175 struct uart_state *state = tty->driver_data;
1176 struct uart_port *uport = state->uart_port;
1178 if (uport->ops->set_ldisc)
1179 uport->ops->set_ldisc(uport, tty->termios->c_line);
1182 static void uart_set_termios(struct tty_struct *tty,
1183 struct ktermios *old_termios)
1185 struct uart_state *state = tty->driver_data;
1186 unsigned long flags;
1187 unsigned int cflag = tty->termios->c_cflag;
1191 * These are the bits that are used to setup various
1192 * flags in the low level driver. We can ignore the Bfoo
1193 * bits in c_cflag; c_[io]speed will always be set
1194 * appropriately by set_termios() in tty_ioctl.c
1196 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1197 if ((cflag ^ old_termios->c_cflag) == 0 &&
1198 tty->termios->c_ospeed == old_termios->c_ospeed &&
1199 tty->termios->c_ispeed == old_termios->c_ispeed &&
1200 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1204 uart_change_speed(tty, state, old_termios);
1206 /* Handle transition to B0 status */
1207 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1208 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1209 /* Handle transition away from B0 status */
1210 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1211 unsigned int mask = TIOCM_DTR;
1212 if (!(cflag & CRTSCTS) ||
1213 !test_bit(TTY_THROTTLED, &tty->flags))
1215 uart_set_mctrl(state->uart_port, mask);
1218 /* Handle turning off CRTSCTS */
1219 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1220 spin_lock_irqsave(&state->uart_port->lock, flags);
1221 tty->hw_stopped = 0;
1223 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1225 /* Handle turning on CRTSCTS */
1226 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1227 spin_lock_irqsave(&state->uart_port->lock, flags);
1228 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1229 tty->hw_stopped = 1;
1230 state->uart_port->ops->stop_tx(state->uart_port);
1232 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1237 * In 2.4.5, calls to this will be serialized via the BKL in
1238 * linux/drivers/char/tty_io.c:tty_release()
1239 * linux/drivers/char/tty_io.c:do_tty_handup()
1241 static void uart_close(struct tty_struct *tty, struct file *filp)
1243 struct uart_state *state = tty->driver_data;
1244 struct tty_port *port;
1245 struct uart_port *uport;
1246 unsigned long flags;
1251 uport = state->uart_port;
1252 port = &state->port;
1254 pr_debug("uart_close(%d) called\n", uport->line);
1256 spin_lock_irqsave(&port->lock, flags);
1258 if (tty_hung_up_p(filp)) {
1259 spin_unlock_irqrestore(&port->lock, flags);
1263 if ((tty->count == 1) && (port->count != 1)) {
1265 * Uh, oh. tty->count is 1, which means that the tty
1266 * structure will be freed. port->count should always
1267 * be one in these conditions. If it's greater than
1268 * one, we've got real problems, since it means the
1269 * serial port won't be shutdown.
1271 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1272 "port->count is %d\n", port->count);
1275 if (--port->count < 0) {
1276 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1277 tty->name, port->count);
1281 spin_unlock_irqrestore(&port->lock, flags);
1286 * Now we wait for the transmit buffer to clear; and we notify
1287 * the line discipline to only process XON/XOFF characters by
1288 * setting tty->closing.
1290 set_bit(ASYNCB_CLOSING, &port->flags);
1292 spin_unlock_irqrestore(&port->lock, flags);
1294 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1295 tty_wait_until_sent_from_close(tty,
1296 msecs_to_jiffies(port->closing_wait));
1299 * At this point, we stop accepting input. To do this, we
1300 * disable the receive line status interrupts.
1302 if (port->flags & ASYNC_INITIALIZED) {
1303 unsigned long flags;
1304 spin_lock_irqsave(&uport->lock, flags);
1305 uport->ops->stop_rx(uport);
1306 spin_unlock_irqrestore(&uport->lock, flags);
1308 * Before we drop DTR, make sure the UART transmitter
1309 * has completely drained; this is especially
1310 * important if there is a transmit FIFO!
1312 uart_wait_until_sent(tty, uport->timeout);
1315 mutex_lock(&port->mutex);
1316 uart_shutdown(tty, state);
1317 uart_flush_buffer(tty);
1319 tty_ldisc_flush(tty);
1321 tty_port_tty_set(port, NULL);
1322 spin_lock_irqsave(&port->lock, flags);
1325 if (port->blocked_open) {
1326 spin_unlock_irqrestore(&port->lock, flags);
1327 if (port->close_delay)
1328 msleep_interruptible(port->close_delay);
1329 spin_lock_irqsave(&port->lock, flags);
1330 } else if (!uart_console(uport)) {
1331 spin_unlock_irqrestore(&port->lock, flags);
1332 uart_change_pm(state, 3);
1333 spin_lock_irqsave(&port->lock, flags);
1337 * Wake up anyone trying to open this port.
1339 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1340 clear_bit(ASYNCB_CLOSING, &port->flags);
1341 spin_unlock_irqrestore(&port->lock, flags);
1342 wake_up_interruptible(&port->open_wait);
1343 wake_up_interruptible(&port->close_wait);
1345 mutex_unlock(&port->mutex);
1348 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1350 struct uart_state *state = tty->driver_data;
1351 struct uart_port *port = state->uart_port;
1352 unsigned long char_time, expire;
1354 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1358 * Set the check interval to be 1/5 of the estimated time to
1359 * send a single character, and make it at least 1. The check
1360 * interval should also be less than the timeout.
1362 * Note: we have to use pretty tight timings here to satisfy
1365 char_time = (port->timeout - HZ/50) / port->fifosize;
1366 char_time = char_time / 5;
1369 if (timeout && timeout < char_time)
1370 char_time = timeout;
1373 * If the transmitter hasn't cleared in twice the approximate
1374 * amount of time to send the entire FIFO, it probably won't
1375 * ever clear. This assumes the UART isn't doing flow
1376 * control, which is currently the case. Hence, if it ever
1377 * takes longer than port->timeout, this is probably due to a
1378 * UART bug of some kind. So, we clamp the timeout parameter at
1381 if (timeout == 0 || timeout > 2 * port->timeout)
1382 timeout = 2 * port->timeout;
1384 expire = jiffies + timeout;
1386 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1387 port->line, jiffies, expire);
1390 * Check whether the transmitter is empty every 'char_time'.
1391 * 'timeout' / 'expire' give us the maximum amount of time
1394 while (!port->ops->tx_empty(port)) {
1395 msleep_interruptible(jiffies_to_msecs(char_time));
1396 if (signal_pending(current))
1398 if (time_after(jiffies, expire))
1404 * This is called with the BKL held in
1405 * linux/drivers/char/tty_io.c:do_tty_hangup()
1406 * We're called from the eventd thread, so we can sleep for
1407 * a _short_ time only.
1409 static void uart_hangup(struct tty_struct *tty)
1411 struct uart_state *state = tty->driver_data;
1412 struct tty_port *port = &state->port;
1413 unsigned long flags;
1415 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1417 mutex_lock(&port->mutex);
1418 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1419 uart_flush_buffer(tty);
1420 uart_shutdown(tty, state);
1421 spin_lock_irqsave(&port->lock, flags);
1423 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1424 spin_unlock_irqrestore(&port->lock, flags);
1425 tty_port_tty_set(port, NULL);
1426 wake_up_interruptible(&port->open_wait);
1427 wake_up_interruptible(&port->delta_msr_wait);
1429 mutex_unlock(&port->mutex);
1432 static int uart_carrier_raised(struct tty_port *port)
1434 struct uart_state *state = container_of(port, struct uart_state, port);
1435 struct uart_port *uport = state->uart_port;
1437 spin_lock_irq(&uport->lock);
1438 uport->ops->enable_ms(uport);
1439 mctrl = uport->ops->get_mctrl(uport);
1440 spin_unlock_irq(&uport->lock);
1441 if (mctrl & TIOCM_CAR)
1446 static void uart_dtr_rts(struct tty_port *port, int onoff)
1448 struct uart_state *state = container_of(port, struct uart_state, port);
1449 struct uart_port *uport = state->uart_port;
1452 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1454 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1457 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1459 struct uart_state *state;
1460 struct tty_port *port;
1463 state = drv->state + line;
1464 port = &state->port;
1465 if (mutex_lock_interruptible(&port->mutex)) {
1471 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1479 mutex_unlock(&port->mutex);
1481 return ERR_PTR(ret);
1485 * calls to uart_open are serialised by the BKL in
1486 * fs/char_dev.c:chrdev_open()
1487 * Note that if this fails, then uart_close() _will_ be called.
1489 * In time, we want to scrap the "opening nonpresent ports"
1490 * behaviour and implement an alternative way for setserial
1491 * to set base addresses/ports/types. This will allow us to
1492 * get rid of a certain amount of extra tests.
1494 static int uart_open(struct tty_struct *tty, struct file *filp)
1496 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1497 struct uart_state *state;
1498 struct tty_port *port;
1499 int retval, line = tty->index;
1501 pr_debug("uart_open(%d) called\n", line);
1504 * We take the semaphore inside uart_get to guarantee that we won't
1505 * be re-entered while allocating the state structure, or while we
1506 * request any IRQs that the driver may need. This also has the nice
1507 * side-effect that it delays the action of uart_hangup, so we can
1508 * guarantee that state->port.tty will always contain something
1511 state = uart_get(drv, line);
1512 if (IS_ERR(state)) {
1513 retval = PTR_ERR(state);
1516 port = &state->port;
1519 * Once we set tty->driver_data here, we are guaranteed that
1520 * uart_close() will decrement the driver module use count.
1521 * Any failures from here onwards should not touch the count.
1523 tty->driver_data = state;
1524 state->uart_port->state = state;
1525 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1527 tty_port_tty_set(port, tty);
1530 * If the port is in the middle of closing, bail out now.
1532 if (tty_hung_up_p(filp)) {
1535 mutex_unlock(&port->mutex);
1540 * Make sure the device is in D0 state.
1542 if (port->count == 1)
1543 uart_change_pm(state, 0);
1546 * Start up the serial port.
1548 retval = uart_startup(tty, state, 0);
1551 * If we succeeded, wait until the port is ready.
1553 mutex_unlock(&port->mutex);
1555 retval = tty_port_block_til_ready(port, tty, filp);
1561 static const char *uart_type(struct uart_port *port)
1563 const char *str = NULL;
1565 if (port->ops->type)
1566 str = port->ops->type(port);
1574 #ifdef CONFIG_PROC_FS
1576 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1578 struct uart_state *state = drv->state + i;
1579 struct tty_port *port = &state->port;
1581 struct uart_port *uport = state->uart_port;
1583 unsigned int status;
1589 mmio = uport->iotype >= UPIO_MEM;
1590 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1591 uport->line, uart_type(uport),
1592 mmio ? "mmio:0x" : "port:",
1593 mmio ? (unsigned long long)uport->mapbase
1594 : (unsigned long long)uport->iobase,
1597 if (uport->type == PORT_UNKNOWN) {
1602 if (capable(CAP_SYS_ADMIN)) {
1603 mutex_lock(&port->mutex);
1604 pm_state = state->pm_state;
1606 uart_change_pm(state, 0);
1607 spin_lock_irq(&uport->lock);
1608 status = uport->ops->get_mctrl(uport);
1609 spin_unlock_irq(&uport->lock);
1611 uart_change_pm(state, pm_state);
1612 mutex_unlock(&port->mutex);
1614 seq_printf(m, " tx:%d rx:%d",
1615 uport->icount.tx, uport->icount.rx);
1616 if (uport->icount.frame)
1617 seq_printf(m, " fe:%d",
1618 uport->icount.frame);
1619 if (uport->icount.parity)
1620 seq_printf(m, " pe:%d",
1621 uport->icount.parity);
1622 if (uport->icount.brk)
1623 seq_printf(m, " brk:%d",
1625 if (uport->icount.overrun)
1626 seq_printf(m, " oe:%d",
1627 uport->icount.overrun);
1629 #define INFOBIT(bit, str) \
1630 if (uport->mctrl & (bit)) \
1631 strncat(stat_buf, (str), sizeof(stat_buf) - \
1632 strlen(stat_buf) - 2)
1633 #define STATBIT(bit, str) \
1634 if (status & (bit)) \
1635 strncat(stat_buf, (str), sizeof(stat_buf) - \
1636 strlen(stat_buf) - 2)
1640 INFOBIT(TIOCM_RTS, "|RTS");
1641 STATBIT(TIOCM_CTS, "|CTS");
1642 INFOBIT(TIOCM_DTR, "|DTR");
1643 STATBIT(TIOCM_DSR, "|DSR");
1644 STATBIT(TIOCM_CAR, "|CD");
1645 STATBIT(TIOCM_RNG, "|RI");
1649 seq_puts(m, stat_buf);
1656 static int uart_proc_show(struct seq_file *m, void *v)
1658 struct tty_driver *ttydrv = m->private;
1659 struct uart_driver *drv = ttydrv->driver_state;
1662 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1664 for (i = 0; i < drv->nr; i++)
1665 uart_line_info(m, drv, i);
1669 static int uart_proc_open(struct inode *inode, struct file *file)
1671 return single_open(file, uart_proc_show, PDE(inode)->data);
1674 static const struct file_operations uart_proc_fops = {
1675 .owner = THIS_MODULE,
1676 .open = uart_proc_open,
1678 .llseek = seq_lseek,
1679 .release = single_release,
1683 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1685 * uart_console_write - write a console message to a serial port
1686 * @port: the port to write the message
1687 * @s: array of characters
1688 * @count: number of characters in string to write
1689 * @write: function to write character to port
1691 void uart_console_write(struct uart_port *port, const char *s,
1693 void (*putchar)(struct uart_port *, int))
1697 for (i = 0; i < count; i++, s++) {
1699 putchar(port, '\r');
1703 EXPORT_SYMBOL_GPL(uart_console_write);
1706 * Check whether an invalid uart number has been specified, and
1707 * if so, search for the first available port that does have
1710 struct uart_port * __init
1711 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1713 int idx = co->index;
1715 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1716 ports[idx].membase == NULL))
1717 for (idx = 0; idx < nr; idx++)
1718 if (ports[idx].iobase != 0 ||
1719 ports[idx].membase != NULL)
1728 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1729 * @options: pointer to option string
1730 * @baud: pointer to an 'int' variable for the baud rate.
1731 * @parity: pointer to an 'int' variable for the parity.
1732 * @bits: pointer to an 'int' variable for the number of data bits.
1733 * @flow: pointer to an 'int' variable for the flow control character.
1735 * uart_parse_options decodes a string containing the serial console
1736 * options. The format of the string is <baud><parity><bits><flow>,
1740 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1744 *baud = simple_strtoul(s, NULL, 10);
1745 while (*s >= '0' && *s <= '9')
1754 EXPORT_SYMBOL_GPL(uart_parse_options);
1761 static const struct baud_rates baud_rates[] = {
1762 { 921600, B921600 },
1763 { 460800, B460800 },
1764 { 230400, B230400 },
1765 { 115200, B115200 },
1777 * uart_set_options - setup the serial console parameters
1778 * @port: pointer to the serial ports uart_port structure
1779 * @co: console pointer
1781 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1782 * @bits: number of data bits
1783 * @flow: flow control character - 'r' (rts)
1786 uart_set_options(struct uart_port *port, struct console *co,
1787 int baud, int parity, int bits, int flow)
1789 struct ktermios termios;
1790 static struct ktermios dummy;
1794 * Ensure that the serial console lock is initialised
1797 spin_lock_init(&port->lock);
1798 lockdep_set_class(&port->lock, &port_lock_key);
1800 memset(&termios, 0, sizeof(struct ktermios));
1802 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1805 * Construct a cflag setting.
1807 for (i = 0; baud_rates[i].rate; i++)
1808 if (baud_rates[i].rate <= baud)
1811 termios.c_cflag |= baud_rates[i].cflag;
1814 termios.c_cflag |= CS7;
1816 termios.c_cflag |= CS8;
1820 termios.c_cflag |= PARODD;
1823 termios.c_cflag |= PARENB;
1828 termios.c_cflag |= CRTSCTS;
1831 * some uarts on other side don't support no flow control.
1832 * So we set * DTR in host uart to make them happy
1834 port->mctrl |= TIOCM_DTR;
1836 port->ops->set_termios(port, &termios, &dummy);
1838 * Allow the setting of the UART parameters with a NULL console
1842 co->cflag = termios.c_cflag;
1846 EXPORT_SYMBOL_GPL(uart_set_options);
1847 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1849 static void uart_change_pm(struct uart_state *state, int pm_state)
1851 struct uart_port *port = state->uart_port;
1853 if (state->pm_state != pm_state) {
1855 port->ops->pm(port, pm_state, state->pm_state);
1856 state->pm_state = pm_state;
1861 struct uart_port *port;
1862 struct uart_driver *driver;
1865 static int serial_match_port(struct device *dev, void *data)
1867 struct uart_match *match = data;
1868 struct tty_driver *tty_drv = match->driver->tty_driver;
1869 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1872 return dev->devt == devt; /* Actually, only one tty per port */
1875 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1877 struct uart_state *state = drv->state + uport->line;
1878 struct tty_port *port = &state->port;
1879 struct device *tty_dev;
1880 struct uart_match match = {uport, drv};
1882 mutex_lock(&port->mutex);
1884 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1885 if (device_may_wakeup(tty_dev)) {
1886 if (!enable_irq_wake(uport->irq))
1887 uport->irq_wake = 1;
1888 put_device(tty_dev);
1889 mutex_unlock(&port->mutex);
1892 if (console_suspend_enabled || !uart_console(uport))
1893 uport->suspended = 1;
1895 if (port->flags & ASYNC_INITIALIZED) {
1896 const struct uart_ops *ops = uport->ops;
1899 if (console_suspend_enabled || !uart_console(uport)) {
1900 set_bit(ASYNCB_SUSPENDED, &port->flags);
1901 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1903 spin_lock_irq(&uport->lock);
1904 ops->stop_tx(uport);
1905 ops->set_mctrl(uport, 0);
1906 ops->stop_rx(uport);
1907 spin_unlock_irq(&uport->lock);
1911 * Wait for the transmitter to empty.
1913 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1916 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1918 uport->dev ? dev_name(uport->dev) : "",
1919 uport->dev ? ": " : "",
1921 drv->tty_driver->name_base + uport->line);
1923 if (console_suspend_enabled || !uart_console(uport))
1924 ops->shutdown(uport);
1928 * Disable the console device before suspending.
1930 if (console_suspend_enabled && uart_console(uport))
1931 console_stop(uport->cons);
1933 if (console_suspend_enabled || !uart_console(uport))
1934 uart_change_pm(state, 3);
1936 mutex_unlock(&port->mutex);
1941 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1943 struct uart_state *state = drv->state + uport->line;
1944 struct tty_port *port = &state->port;
1945 struct device *tty_dev;
1946 struct uart_match match = {uport, drv};
1947 struct ktermios termios;
1949 mutex_lock(&port->mutex);
1951 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1952 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1953 if (uport->irq_wake) {
1954 disable_irq_wake(uport->irq);
1955 uport->irq_wake = 0;
1957 mutex_unlock(&port->mutex);
1960 uport->suspended = 0;
1963 * Re-enable the console device after suspending.
1965 if (uart_console(uport)) {
1967 * First try to use the console cflag setting.
1969 memset(&termios, 0, sizeof(struct ktermios));
1970 termios.c_cflag = uport->cons->cflag;
1973 * If that's unset, use the tty termios setting.
1975 if (port->tty && port->tty->termios && termios.c_cflag == 0)
1976 termios = *(port->tty->termios);
1978 if (console_suspend_enabled)
1979 uart_change_pm(state, 0);
1980 uport->ops->set_termios(uport, &termios, NULL);
1981 if (console_suspend_enabled)
1982 console_start(uport->cons);
1985 if (port->flags & ASYNC_SUSPENDED) {
1986 const struct uart_ops *ops = uport->ops;
1989 uart_change_pm(state, 0);
1990 spin_lock_irq(&uport->lock);
1991 ops->set_mctrl(uport, 0);
1992 spin_unlock_irq(&uport->lock);
1993 if (console_suspend_enabled || !uart_console(uport)) {
1994 /* Protected by port mutex for now */
1995 struct tty_struct *tty = port->tty;
1996 ret = ops->startup(uport);
1999 uart_change_speed(tty, state, NULL);
2000 spin_lock_irq(&uport->lock);
2001 ops->set_mctrl(uport, uport->mctrl);
2002 ops->start_tx(uport);
2003 spin_unlock_irq(&uport->lock);
2004 set_bit(ASYNCB_INITIALIZED, &port->flags);
2007 * Failed to resume - maybe hardware went away?
2008 * Clear the "initialized" flag so we won't try
2009 * to call the low level drivers shutdown method.
2011 uart_shutdown(tty, state);
2015 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2018 mutex_unlock(&port->mutex);
2024 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2028 switch (port->iotype) {
2030 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2033 snprintf(address, sizeof(address),
2034 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2040 snprintf(address, sizeof(address),
2041 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2044 strlcpy(address, "*unknown*", sizeof(address));
2048 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2049 port->dev ? dev_name(port->dev) : "",
2050 port->dev ? ": " : "",
2052 drv->tty_driver->name_base + port->line,
2053 address, port->irq, uart_type(port));
2057 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2058 struct uart_port *port)
2063 * If there isn't a port here, don't do anything further.
2065 if (!port->iobase && !port->mapbase && !port->membase)
2069 * Now do the auto configuration stuff. Note that config_port
2070 * is expected to claim the resources and map the port for us.
2073 if (port->flags & UPF_AUTO_IRQ)
2074 flags |= UART_CONFIG_IRQ;
2075 if (port->flags & UPF_BOOT_AUTOCONF) {
2076 if (!(port->flags & UPF_FIXED_TYPE)) {
2077 port->type = PORT_UNKNOWN;
2078 flags |= UART_CONFIG_TYPE;
2080 port->ops->config_port(port, flags);
2083 if (port->type != PORT_UNKNOWN) {
2084 unsigned long flags;
2086 uart_report_port(drv, port);
2088 /* Power up port for set_mctrl() */
2089 uart_change_pm(state, 0);
2092 * Ensure that the modem control lines are de-activated.
2093 * keep the DTR setting that is set in uart_set_options()
2094 * We probably don't need a spinlock around this, but
2096 spin_lock_irqsave(&port->lock, flags);
2097 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2098 spin_unlock_irqrestore(&port->lock, flags);
2101 * If this driver supports console, and it hasn't been
2102 * successfully registered yet, try to re-register it.
2103 * It may be that the port was not available.
2105 if (port->cons && !(port->cons->flags & CON_ENABLED))
2106 register_console(port->cons);
2109 * Power down all ports by default, except the
2110 * console if we have one.
2112 if (!uart_console(port))
2113 uart_change_pm(state, 3);
2117 #ifdef CONFIG_CONSOLE_POLL
2119 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2121 struct uart_driver *drv = driver->driver_state;
2122 struct uart_state *state = drv->state + line;
2123 struct uart_port *port;
2129 if (!state || !state->uart_port)
2132 port = state->uart_port;
2133 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2137 uart_parse_options(options, &baud, &parity, &bits, &flow);
2138 return uart_set_options(port, NULL, baud, parity, bits, flow);
2144 static int uart_poll_get_char(struct tty_driver *driver, int line)
2146 struct uart_driver *drv = driver->driver_state;
2147 struct uart_state *state = drv->state + line;
2148 struct uart_port *port;
2150 if (!state || !state->uart_port)
2153 port = state->uart_port;
2154 return port->ops->poll_get_char(port);
2157 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2159 struct uart_driver *drv = driver->driver_state;
2160 struct uart_state *state = drv->state + line;
2161 struct uart_port *port;
2163 if (!state || !state->uart_port)
2166 port = state->uart_port;
2167 port->ops->poll_put_char(port, ch);
2171 static const struct tty_operations uart_ops = {
2173 .close = uart_close,
2174 .write = uart_write,
2175 .put_char = uart_put_char,
2176 .flush_chars = uart_flush_chars,
2177 .write_room = uart_write_room,
2178 .chars_in_buffer= uart_chars_in_buffer,
2179 .flush_buffer = uart_flush_buffer,
2180 .ioctl = uart_ioctl,
2181 .throttle = uart_throttle,
2182 .unthrottle = uart_unthrottle,
2183 .send_xchar = uart_send_xchar,
2184 .set_termios = uart_set_termios,
2185 .set_ldisc = uart_set_ldisc,
2187 .start = uart_start,
2188 .hangup = uart_hangup,
2189 .break_ctl = uart_break_ctl,
2190 .wait_until_sent= uart_wait_until_sent,
2191 #ifdef CONFIG_PROC_FS
2192 .proc_fops = &uart_proc_fops,
2194 .tiocmget = uart_tiocmget,
2195 .tiocmset = uart_tiocmset,
2196 .get_icount = uart_get_icount,
2197 #ifdef CONFIG_CONSOLE_POLL
2198 .poll_init = uart_poll_init,
2199 .poll_get_char = uart_poll_get_char,
2200 .poll_put_char = uart_poll_put_char,
2204 static const struct tty_port_operations uart_port_ops = {
2205 .carrier_raised = uart_carrier_raised,
2206 .dtr_rts = uart_dtr_rts,
2210 * uart_register_driver - register a driver with the uart core layer
2211 * @drv: low level driver structure
2213 * Register a uart driver with the core driver. We in turn register
2214 * with the tty layer, and initialise the core driver per-port state.
2216 * We have a proc file in /proc/tty/driver which is named after the
2219 * drv->port should be NULL, and the per-port structures should be
2220 * registered using uart_add_one_port after this call has succeeded.
2222 int uart_register_driver(struct uart_driver *drv)
2224 struct tty_driver *normal;
2230 * Maybe we should be using a slab cache for this, especially if
2231 * we have a large number of ports to handle.
2233 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2237 normal = alloc_tty_driver(drv->nr);
2241 drv->tty_driver = normal;
2243 normal->owner = drv->owner;
2244 normal->driver_name = drv->driver_name;
2245 normal->name = drv->dev_name;
2246 normal->major = drv->major;
2247 normal->minor_start = drv->minor;
2248 normal->type = TTY_DRIVER_TYPE_SERIAL;
2249 normal->subtype = SERIAL_TYPE_NORMAL;
2250 normal->init_termios = tty_std_termios;
2251 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2252 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2253 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2254 normal->driver_state = drv;
2255 tty_set_operations(normal, &uart_ops);
2258 * Initialise the UART state(s).
2260 for (i = 0; i < drv->nr; i++) {
2261 struct uart_state *state = drv->state + i;
2262 struct tty_port *port = &state->port;
2264 tty_port_init(port);
2265 port->ops = &uart_port_ops;
2266 port->close_delay = 500; /* .5 seconds */
2267 port->closing_wait = 30000; /* 30 seconds */
2270 retval = tty_register_driver(normal);
2274 put_tty_driver(normal);
2282 * uart_unregister_driver - remove a driver from the uart core layer
2283 * @drv: low level driver structure
2285 * Remove all references to a driver from the core driver. The low
2286 * level driver must have removed all its ports via the
2287 * uart_remove_one_port() if it registered them with uart_add_one_port().
2288 * (ie, drv->port == NULL)
2290 void uart_unregister_driver(struct uart_driver *drv)
2292 struct tty_driver *p = drv->tty_driver;
2293 tty_unregister_driver(p);
2296 drv->tty_driver = NULL;
2299 struct tty_driver *uart_console_device(struct console *co, int *index)
2301 struct uart_driver *p = co->data;
2303 return p->tty_driver;
2307 * uart_add_one_port - attach a driver-defined port structure
2308 * @drv: pointer to the uart low level driver structure for this port
2309 * @uport: uart port structure to use for this port.
2311 * This allows the driver to register its own uart_port structure
2312 * with the core driver. The main purpose is to allow the low
2313 * level uart drivers to expand uart_port, rather than having yet
2314 * more levels of structures.
2316 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2318 struct uart_state *state;
2319 struct tty_port *port;
2321 struct device *tty_dev;
2323 BUG_ON(in_interrupt());
2325 if (uport->line >= drv->nr)
2328 state = drv->state + uport->line;
2329 port = &state->port;
2331 mutex_lock(&port_mutex);
2332 mutex_lock(&port->mutex);
2333 if (state->uart_port) {
2338 state->uart_port = uport;
2339 state->pm_state = -1;
2341 uport->cons = drv->cons;
2342 uport->state = state;
2345 * If this port is a console, then the spinlock is already
2348 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2349 spin_lock_init(&uport->lock);
2350 lockdep_set_class(&uport->lock, &port_lock_key);
2353 uart_configure_port(drv, state, uport);
2356 * Register the port whether it's detected or not. This allows
2357 * setserial to be used to alter this ports parameters.
2359 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2360 if (likely(!IS_ERR(tty_dev))) {
2361 device_init_wakeup(tty_dev, 1);
2362 device_set_wakeup_enable(tty_dev, 0);
2364 printk(KERN_ERR "Cannot register tty device on line %d\n",
2368 * Ensure UPF_DEAD is not set.
2370 uport->flags &= ~UPF_DEAD;
2373 mutex_unlock(&port->mutex);
2374 mutex_unlock(&port_mutex);
2380 * uart_remove_one_port - detach a driver defined port structure
2381 * @drv: pointer to the uart low level driver structure for this port
2382 * @uport: uart port structure for this port
2384 * This unhooks (and hangs up) the specified port structure from the
2385 * core driver. No further calls will be made to the low-level code
2388 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2390 struct uart_state *state = drv->state + uport->line;
2391 struct tty_port *port = &state->port;
2393 BUG_ON(in_interrupt());
2395 if (state->uart_port != uport)
2396 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2397 state->uart_port, uport);
2399 mutex_lock(&port_mutex);
2402 * Mark the port "dead" - this prevents any opens from
2403 * succeeding while we shut down the port.
2405 mutex_lock(&port->mutex);
2406 uport->flags |= UPF_DEAD;
2407 mutex_unlock(&port->mutex);
2410 * Remove the devices from the tty layer
2412 tty_unregister_device(drv->tty_driver, uport->line);
2415 tty_vhangup(port->tty);
2418 * Free the port IO and memory resources, if any.
2420 if (uport->type != PORT_UNKNOWN)
2421 uport->ops->release_port(uport);
2424 * Indicate that there isn't a port here anymore.
2426 uport->type = PORT_UNKNOWN;
2428 state->uart_port = NULL;
2429 mutex_unlock(&port_mutex);
2435 * Are the two ports equivalent?
2437 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2439 if (port1->iotype != port2->iotype)
2442 switch (port1->iotype) {
2444 return (port1->iobase == port2->iobase);
2446 return (port1->iobase == port2->iobase) &&
2447 (port1->hub6 == port2->hub6);
2452 return (port1->mapbase == port2->mapbase);
2456 EXPORT_SYMBOL(uart_match_port);
2458 EXPORT_SYMBOL(uart_write_wakeup);
2459 EXPORT_SYMBOL(uart_register_driver);
2460 EXPORT_SYMBOL(uart_unregister_driver);
2461 EXPORT_SYMBOL(uart_suspend_port);
2462 EXPORT_SYMBOL(uart_resume_port);
2463 EXPORT_SYMBOL(uart_add_one_port);
2464 EXPORT_SYMBOL(uart_remove_one_port);
2466 MODULE_DESCRIPTION("Serial driver core");
2467 MODULE_LICENSE("GPL");