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/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/proc_fs.h>
30 #include <linux/seq_file.h>
31 #include <linux/device.h>
32 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33 #include <linux/serial_core.h>
34 #include <linux/delay.h>
35 #include <linux/mutex.h>
38 #include <asm/uaccess.h>
41 * This is used to lock changes in serial line configuration.
43 static DEFINE_MUTEX(port_mutex);
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
49 static struct lock_class_key port_lock_key;
51 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53 #ifdef CONFIG_SERIAL_CORE_CONSOLE
54 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
56 #define uart_console(port) (0)
59 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
60 struct ktermios *old_termios);
61 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
62 static void uart_change_pm(struct uart_state *state, int pm_state);
64 static void uart_port_shutdown(struct tty_port *port);
67 * This routine is used by the interrupt handler to schedule processing in
68 * the software interrupt portion of the driver.
70 void uart_write_wakeup(struct uart_port *port)
72 struct uart_state *state = port->state;
74 * This means you called this function _after_ the port was
75 * closed. No cookie for you.
78 tty_wakeup(state->port.tty);
81 static void uart_stop(struct tty_struct *tty)
83 struct uart_state *state = tty->driver_data;
84 struct uart_port *port = state->uart_port;
87 spin_lock_irqsave(&port->lock, flags);
88 port->ops->stop_tx(port);
89 spin_unlock_irqrestore(&port->lock, flags);
92 static void __uart_start(struct tty_struct *tty)
94 struct uart_state *state = tty->driver_data;
95 struct uart_port *port = state->uart_port;
97 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
98 !tty->stopped && !tty->hw_stopped)
99 port->ops->start_tx(port);
102 static void uart_start(struct tty_struct *tty)
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
108 spin_lock_irqsave(&port->lock, flags);
110 spin_unlock_irqrestore(&port->lock, flags);
114 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
119 spin_lock_irqsave(&port->lock, flags);
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
127 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
134 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
137 struct uart_port *uport = state->uart_port;
138 struct tty_port *port = &state->port;
142 if (uport->type == PORT_UNKNOWN)
146 * Initialise and allocate the transmit and temporary
149 if (!state->xmit.buf) {
150 /* This is protected by the per port mutex */
151 page = get_zeroed_page(GFP_KERNEL);
155 state->xmit.buf = (unsigned char *) page;
156 uart_circ_clear(&state->xmit);
159 retval = uport->ops->startup(uport);
161 if (uart_console(uport) && uport->cons->cflag) {
162 tty->termios.c_cflag = uport->cons->cflag;
163 uport->cons->cflag = 0;
166 * Initialise the hardware port settings.
168 uart_change_speed(tty, state, NULL);
172 * Setup the RTS and DTR signals once the
173 * port is open and ready to respond.
175 if (tty->termios.c_cflag & CBAUD)
176 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
179 if (tty_port_cts_enabled(port)) {
180 spin_lock_irq(&uport->lock);
181 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
183 spin_unlock_irq(&uport->lock);
188 * This is to allow setserial on this port. People may want to set
189 * port/irq/type and then reconfigure the port properly if it failed
192 if (retval && capable(CAP_SYS_ADMIN))
198 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
201 struct tty_port *port = &state->port;
204 if (port->flags & ASYNC_INITIALIZED)
208 * Set the TTY IO error marker - we will only clear this
209 * once we have successfully opened the port.
211 set_bit(TTY_IO_ERROR, &tty->flags);
213 retval = uart_port_startup(tty, state, init_hw);
215 set_bit(ASYNCB_INITIALIZED, &port->flags);
216 clear_bit(TTY_IO_ERROR, &tty->flags);
217 } else if (retval > 0)
224 * This routine will shutdown a serial port; interrupts are disabled, and
225 * DTR is dropped if the hangup on close termio flag is on. Calls to
226 * uart_shutdown are serialised by the per-port semaphore.
228 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
230 struct uart_port *uport = state->uart_port;
231 struct tty_port *port = &state->port;
234 * Set the TTY IO error marker
237 set_bit(TTY_IO_ERROR, &tty->flags);
239 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
241 * Turn off DTR and RTS early.
243 if (!tty || (tty->termios.c_cflag & HUPCL))
244 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
246 uart_port_shutdown(port);
250 * It's possible for shutdown to be called after suspend if we get
251 * a DCD drop (hangup) at just the right time. Clear suspended bit so
252 * we don't try to resume a port that has been shutdown.
254 clear_bit(ASYNCB_SUSPENDED, &port->flags);
257 * Free the transmit buffer page.
259 if (state->xmit.buf) {
260 free_page((unsigned long)state->xmit.buf);
261 state->xmit.buf = NULL;
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
275 uart_update_timeout(struct uart_port *port, unsigned int cflag,
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
302 * The total number of bits to be transmitted in the fifo.
304 bits = bits * port->fifosize;
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
310 port->timeout = (HZ * bits) / baud + HZ/50;
313 EXPORT_SYMBOL(uart_update_timeout);
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using. Don't do this for the case
332 * where B0 is requested ("hang up").
335 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min, unsigned int max)
338 unsigned int try, baud, altbaud = 38400;
340 upf_t flags = port->flags & UPF_SPD_MASK;
342 if (flags == UPF_SPD_HI)
344 else if (flags == UPF_SPD_VHI)
346 else if (flags == UPF_SPD_SHI)
348 else if (flags == UPF_SPD_WARP)
351 for (try = 0; try < 2; try++) {
352 baud = tty_termios_baud_rate(termios);
355 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
362 * Special case: B0 rate.
369 if (baud >= min && baud <= max)
373 * Oops, the quotient was zero. Try again with
374 * the old baud rate if possible.
376 termios->c_cflag &= ~CBAUD;
378 baud = tty_termios_baud_rate(old);
380 tty_termios_encode_baud_rate(termios,
387 * As a last resort, if the range cannot be met then clip to
388 * the nearest chip supported rate.
392 tty_termios_encode_baud_rate(termios,
395 tty_termios_encode_baud_rate(termios,
399 /* Should never happen */
404 EXPORT_SYMBOL(uart_get_baud_rate);
407 * uart_get_divisor - return uart clock divisor
408 * @port: uart_port structure describing the port.
409 * @baud: desired baud rate
411 * Calculate the uart clock divisor for the port.
414 uart_get_divisor(struct uart_port *port, unsigned int baud)
419 * Old custom speed handling.
421 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
422 quot = port->custom_divisor;
424 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
429 EXPORT_SYMBOL(uart_get_divisor);
431 /* FIXME: Consistent locking policy */
432 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
433 struct ktermios *old_termios)
435 struct tty_port *port = &state->port;
436 struct uart_port *uport = state->uart_port;
437 struct ktermios *termios;
440 * If we have no tty, termios, or the port does not exist,
441 * then we can't set the parameters for this port.
443 if (!tty || uport->type == PORT_UNKNOWN)
446 termios = &tty->termios;
449 * Set flags based on termios cflag
451 if (termios->c_cflag & CRTSCTS)
452 set_bit(ASYNCB_CTS_FLOW, &port->flags);
454 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
456 if (termios->c_cflag & CLOCAL)
457 clear_bit(ASYNCB_CHECK_CD, &port->flags);
459 set_bit(ASYNCB_CHECK_CD, &port->flags);
461 uport->ops->set_termios(uport, termios, old_termios);
464 static inline int __uart_put_char(struct uart_port *port,
465 struct circ_buf *circ, unsigned char c)
473 spin_lock_irqsave(&port->lock, flags);
474 if (uart_circ_chars_free(circ) != 0) {
475 circ->buf[circ->head] = c;
476 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
479 spin_unlock_irqrestore(&port->lock, flags);
483 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
485 struct uart_state *state = tty->driver_data;
487 return __uart_put_char(state->uart_port, &state->xmit, ch);
490 static void uart_flush_chars(struct tty_struct *tty)
495 static int uart_write(struct tty_struct *tty,
496 const unsigned char *buf, int count)
498 struct uart_state *state = tty->driver_data;
499 struct uart_port *port;
500 struct circ_buf *circ;
505 * This means you called this function _after_ the port was
506 * closed. No cookie for you.
513 port = state->uart_port;
519 spin_lock_irqsave(&port->lock, flags);
521 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
526 memcpy(circ->buf + circ->head, buf, c);
527 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
532 spin_unlock_irqrestore(&port->lock, flags);
538 static int uart_write_room(struct tty_struct *tty)
540 struct uart_state *state = tty->driver_data;
544 spin_lock_irqsave(&state->uart_port->lock, flags);
545 ret = uart_circ_chars_free(&state->xmit);
546 spin_unlock_irqrestore(&state->uart_port->lock, flags);
550 static int uart_chars_in_buffer(struct tty_struct *tty)
552 struct uart_state *state = tty->driver_data;
556 spin_lock_irqsave(&state->uart_port->lock, flags);
557 ret = uart_circ_chars_pending(&state->xmit);
558 spin_unlock_irqrestore(&state->uart_port->lock, flags);
562 static void uart_flush_buffer(struct tty_struct *tty)
564 struct uart_state *state = tty->driver_data;
565 struct uart_port *port;
569 * This means you called this function _after_ the port was
570 * closed. No cookie for you.
577 port = state->uart_port;
578 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
580 spin_lock_irqsave(&port->lock, flags);
581 uart_circ_clear(&state->xmit);
582 if (port->ops->flush_buffer)
583 port->ops->flush_buffer(port);
584 spin_unlock_irqrestore(&port->lock, flags);
589 * This function is used to send a high-priority XON/XOFF character to
592 static void uart_send_xchar(struct tty_struct *tty, char ch)
594 struct uart_state *state = tty->driver_data;
595 struct uart_port *port = state->uart_port;
598 if (port->ops->send_xchar)
599 port->ops->send_xchar(port, ch);
603 spin_lock_irqsave(&port->lock, flags);
604 port->ops->start_tx(port);
605 spin_unlock_irqrestore(&port->lock, flags);
610 static void uart_throttle(struct tty_struct *tty)
612 struct uart_state *state = tty->driver_data;
615 uart_send_xchar(tty, STOP_CHAR(tty));
617 if (tty->termios.c_cflag & CRTSCTS)
618 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
621 static void uart_unthrottle(struct tty_struct *tty)
623 struct uart_state *state = tty->driver_data;
624 struct uart_port *port = state->uart_port;
630 uart_send_xchar(tty, START_CHAR(tty));
633 if (tty->termios.c_cflag & CRTSCTS)
634 uart_set_mctrl(port, TIOCM_RTS);
637 static void uart_get_info(struct tty_port *port,
638 struct uart_state *state,
639 struct serial_struct *retinfo)
641 struct uart_port *uport = state->uart_port;
643 memset(retinfo, 0, sizeof(*retinfo));
645 retinfo->type = uport->type;
646 retinfo->line = uport->line;
647 retinfo->port = uport->iobase;
648 if (HIGH_BITS_OFFSET)
649 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
650 retinfo->irq = uport->irq;
651 retinfo->flags = uport->flags;
652 retinfo->xmit_fifo_size = uport->fifosize;
653 retinfo->baud_base = uport->uartclk / 16;
654 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
655 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
656 ASYNC_CLOSING_WAIT_NONE :
657 jiffies_to_msecs(port->closing_wait) / 10;
658 retinfo->custom_divisor = uport->custom_divisor;
659 retinfo->hub6 = uport->hub6;
660 retinfo->io_type = uport->iotype;
661 retinfo->iomem_reg_shift = uport->regshift;
662 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
665 static int uart_get_info_user(struct uart_state *state,
666 struct serial_struct __user *retinfo)
668 struct tty_port *port = &state->port;
669 struct serial_struct tmp;
671 /* Ensure the state we copy is consistent and no hardware changes
673 mutex_lock(&port->mutex);
674 uart_get_info(port, state, &tmp);
675 mutex_unlock(&port->mutex);
677 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
682 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
683 struct uart_state *state,
684 struct serial_struct *new_info)
686 struct uart_port *uport = state->uart_port;
687 unsigned long new_port;
688 unsigned int change_irq, change_port, closing_wait;
689 unsigned int old_custom_divisor, close_delay;
690 upf_t old_flags, new_flags;
693 new_port = new_info->port;
694 if (HIGH_BITS_OFFSET)
695 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
697 new_info->irq = irq_canonicalize(new_info->irq);
698 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
699 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
700 ASYNC_CLOSING_WAIT_NONE :
701 msecs_to_jiffies(new_info->closing_wait * 10);
704 change_irq = !(uport->flags & UPF_FIXED_PORT)
705 && new_info->irq != uport->irq;
708 * Since changing the 'type' of the port changes its resource
709 * allocations, we should treat type changes the same as
712 change_port = !(uport->flags & UPF_FIXED_PORT)
713 && (new_port != uport->iobase ||
714 (unsigned long)new_info->iomem_base != uport->mapbase ||
715 new_info->hub6 != uport->hub6 ||
716 new_info->io_type != uport->iotype ||
717 new_info->iomem_reg_shift != uport->regshift ||
718 new_info->type != uport->type);
720 old_flags = uport->flags;
721 new_flags = new_info->flags;
722 old_custom_divisor = uport->custom_divisor;
724 if (!capable(CAP_SYS_ADMIN)) {
726 if (change_irq || change_port ||
727 (new_info->baud_base != uport->uartclk / 16) ||
728 (close_delay != port->close_delay) ||
729 (closing_wait != port->closing_wait) ||
730 (new_info->xmit_fifo_size &&
731 new_info->xmit_fifo_size != uport->fifosize) ||
732 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
734 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
735 (new_flags & UPF_USR_MASK));
736 uport->custom_divisor = new_info->custom_divisor;
741 * Ask the low level driver to verify the settings.
743 if (uport->ops->verify_port)
744 retval = uport->ops->verify_port(uport, new_info);
746 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
747 (new_info->baud_base < 9600))
753 if (change_port || change_irq) {
757 * Make sure that we are the sole user of this port.
759 if (tty_port_users(port) > 1)
763 * We need to shutdown the serial port at the old
764 * port/type/irq combination.
766 uart_shutdown(tty, state);
770 unsigned long old_iobase, old_mapbase;
771 unsigned int old_type, old_iotype, old_hub6, old_shift;
773 old_iobase = uport->iobase;
774 old_mapbase = uport->mapbase;
775 old_type = uport->type;
776 old_hub6 = uport->hub6;
777 old_iotype = uport->iotype;
778 old_shift = uport->regshift;
781 * Free and release old regions
783 if (old_type != PORT_UNKNOWN)
784 uport->ops->release_port(uport);
786 uport->iobase = new_port;
787 uport->type = new_info->type;
788 uport->hub6 = new_info->hub6;
789 uport->iotype = new_info->io_type;
790 uport->regshift = new_info->iomem_reg_shift;
791 uport->mapbase = (unsigned long)new_info->iomem_base;
794 * Claim and map the new regions
796 if (uport->type != PORT_UNKNOWN) {
797 retval = uport->ops->request_port(uport);
799 /* Always success - Jean II */
804 * If we fail to request resources for the
805 * new port, try to restore the old settings.
807 if (retval && old_type != PORT_UNKNOWN) {
808 uport->iobase = old_iobase;
809 uport->type = old_type;
810 uport->hub6 = old_hub6;
811 uport->iotype = old_iotype;
812 uport->regshift = old_shift;
813 uport->mapbase = old_mapbase;
814 retval = uport->ops->request_port(uport);
816 * If we failed to restore the old settings,
820 uport->type = PORT_UNKNOWN;
826 /* Added to return the correct error -Ram Gupta */
832 uport->irq = new_info->irq;
833 if (!(uport->flags & UPF_FIXED_PORT))
834 uport->uartclk = new_info->baud_base * 16;
835 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
836 (new_flags & UPF_CHANGE_MASK);
837 uport->custom_divisor = new_info->custom_divisor;
838 port->close_delay = close_delay;
839 port->closing_wait = closing_wait;
840 if (new_info->xmit_fifo_size)
841 uport->fifosize = new_info->xmit_fifo_size;
843 port->tty->low_latency =
844 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
848 if (uport->type == PORT_UNKNOWN)
850 if (port->flags & ASYNC_INITIALIZED) {
851 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
852 old_custom_divisor != uport->custom_divisor) {
854 * If they're setting up a custom divisor or speed,
855 * instead of clearing it, then bitch about it. No
856 * need to rate-limit; it's CAP_SYS_ADMIN only.
858 if (uport->flags & UPF_SPD_MASK) {
861 "%s sets custom speed on %s. This "
862 "is deprecated.\n", current->comm,
863 tty_name(port->tty, buf));
865 uart_change_speed(tty, state, NULL);
868 retval = uart_startup(tty, state, 1);
873 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
874 struct serial_struct __user *newinfo)
876 struct serial_struct new_serial;
877 struct tty_port *port = &state->port;
880 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
884 * This semaphore protects port->count. It is also
885 * very useful to prevent opens. Also, take the
886 * port configuration semaphore to make sure that a
887 * module insertion/removal doesn't change anything
890 mutex_lock(&port->mutex);
891 retval = uart_set_info(tty, port, state, &new_serial);
892 mutex_unlock(&port->mutex);
897 * uart_get_lsr_info - get line status register info
898 * @tty: tty associated with the UART
899 * @state: UART being queried
900 * @value: returned modem value
902 * Note: uart_ioctl protects us against hangups.
904 static int uart_get_lsr_info(struct tty_struct *tty,
905 struct uart_state *state, unsigned int __user *value)
907 struct uart_port *uport = state->uart_port;
910 result = uport->ops->tx_empty(uport);
913 * If we're about to load something into the transmit
914 * register, we'll pretend the transmitter isn't empty to
915 * avoid a race condition (depending on when the transmit
916 * interrupt happens).
919 ((uart_circ_chars_pending(&state->xmit) > 0) &&
920 !tty->stopped && !tty->hw_stopped))
921 result &= ~TIOCSER_TEMT;
923 return put_user(result, value);
926 static int uart_tiocmget(struct tty_struct *tty)
928 struct uart_state *state = tty->driver_data;
929 struct tty_port *port = &state->port;
930 struct uart_port *uport = state->uart_port;
933 mutex_lock(&port->mutex);
934 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
935 result = uport->mctrl;
936 spin_lock_irq(&uport->lock);
937 result |= uport->ops->get_mctrl(uport);
938 spin_unlock_irq(&uport->lock);
940 mutex_unlock(&port->mutex);
946 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
948 struct uart_state *state = tty->driver_data;
949 struct uart_port *uport = state->uart_port;
950 struct tty_port *port = &state->port;
953 mutex_lock(&port->mutex);
954 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
955 uart_update_mctrl(uport, set, clear);
958 mutex_unlock(&port->mutex);
962 static int uart_break_ctl(struct tty_struct *tty, int break_state)
964 struct uart_state *state = tty->driver_data;
965 struct tty_port *port = &state->port;
966 struct uart_port *uport = state->uart_port;
968 mutex_lock(&port->mutex);
970 if (uport->type != PORT_UNKNOWN)
971 uport->ops->break_ctl(uport, break_state);
973 mutex_unlock(&port->mutex);
977 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
979 struct uart_port *uport = state->uart_port;
980 struct tty_port *port = &state->port;
983 if (!capable(CAP_SYS_ADMIN))
987 * Take the per-port semaphore. This prevents count from
988 * changing, and hence any extra opens of the port while
989 * we're auto-configuring.
991 if (mutex_lock_interruptible(&port->mutex))
995 if (tty_port_users(port) == 1) {
996 uart_shutdown(tty, state);
999 * If we already have a port type configured,
1000 * we must release its resources.
1002 if (uport->type != PORT_UNKNOWN)
1003 uport->ops->release_port(uport);
1005 flags = UART_CONFIG_TYPE;
1006 if (uport->flags & UPF_AUTO_IRQ)
1007 flags |= UART_CONFIG_IRQ;
1010 * This will claim the ports resources if
1013 uport->ops->config_port(uport, flags);
1015 ret = uart_startup(tty, state, 1);
1017 mutex_unlock(&port->mutex);
1022 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1023 * - mask passed in arg for lines of interest
1024 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1025 * Caller should use TIOCGICOUNT to see which one it was
1027 * FIXME: This wants extracting into a common all driver implementation
1028 * of TIOCMWAIT using tty_port.
1031 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1033 struct uart_port *uport = state->uart_port;
1034 struct tty_port *port = &state->port;
1035 DECLARE_WAITQUEUE(wait, current);
1036 struct uart_icount cprev, cnow;
1040 * note the counters on entry
1042 spin_lock_irq(&uport->lock);
1043 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1046 * Force modem status interrupts on
1048 uport->ops->enable_ms(uport);
1049 spin_unlock_irq(&uport->lock);
1051 add_wait_queue(&port->delta_msr_wait, &wait);
1053 spin_lock_irq(&uport->lock);
1054 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1055 spin_unlock_irq(&uport->lock);
1057 set_current_state(TASK_INTERRUPTIBLE);
1059 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1060 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1061 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1062 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1069 /* see if a signal did it */
1070 if (signal_pending(current)) {
1078 current->state = TASK_RUNNING;
1079 remove_wait_queue(&port->delta_msr_wait, &wait);
1085 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1086 * Return: write counters to the user passed counter struct
1087 * NB: both 1->0 and 0->1 transitions are counted except for
1088 * RI where only 0->1 is counted.
1090 static int uart_get_icount(struct tty_struct *tty,
1091 struct serial_icounter_struct *icount)
1093 struct uart_state *state = tty->driver_data;
1094 struct uart_icount cnow;
1095 struct uart_port *uport = state->uart_port;
1097 spin_lock_irq(&uport->lock);
1098 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1099 spin_unlock_irq(&uport->lock);
1101 icount->cts = cnow.cts;
1102 icount->dsr = cnow.dsr;
1103 icount->rng = cnow.rng;
1104 icount->dcd = cnow.dcd;
1105 icount->rx = cnow.rx;
1106 icount->tx = cnow.tx;
1107 icount->frame = cnow.frame;
1108 icount->overrun = cnow.overrun;
1109 icount->parity = cnow.parity;
1110 icount->brk = cnow.brk;
1111 icount->buf_overrun = cnow.buf_overrun;
1117 * Called via sys_ioctl. We can use spin_lock_irq() here.
1120 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1123 struct uart_state *state = tty->driver_data;
1124 struct tty_port *port = &state->port;
1125 void __user *uarg = (void __user *)arg;
1126 int ret = -ENOIOCTLCMD;
1130 * These ioctls don't rely on the hardware to be present.
1134 ret = uart_get_info_user(state, uarg);
1138 ret = uart_set_info_user(tty, state, uarg);
1142 ret = uart_do_autoconfig(tty, state);
1145 case TIOCSERGWILD: /* obsolete */
1146 case TIOCSERSWILD: /* obsolete */
1151 if (ret != -ENOIOCTLCMD)
1154 if (tty->flags & (1 << TTY_IO_ERROR)) {
1160 * The following should only be used when hardware is present.
1164 ret = uart_wait_modem_status(state, arg);
1168 if (ret != -ENOIOCTLCMD)
1171 mutex_lock(&port->mutex);
1173 if (tty->flags & (1 << TTY_IO_ERROR)) {
1179 * All these rely on hardware being present and need to be
1180 * protected against the tty being hung up.
1183 case TIOCSERGETLSR: /* Get line status register */
1184 ret = uart_get_lsr_info(tty, state, uarg);
1188 struct uart_port *uport = state->uart_port;
1189 if (uport->ops->ioctl)
1190 ret = uport->ops->ioctl(uport, cmd, arg);
1195 mutex_unlock(&port->mutex);
1200 static void uart_set_ldisc(struct tty_struct *tty)
1202 struct uart_state *state = tty->driver_data;
1203 struct uart_port *uport = state->uart_port;
1205 if (uport->ops->set_ldisc)
1206 uport->ops->set_ldisc(uport, tty->termios.c_line);
1209 static void uart_set_termios(struct tty_struct *tty,
1210 struct ktermios *old_termios)
1212 struct uart_state *state = tty->driver_data;
1213 unsigned long flags;
1214 unsigned int cflag = tty->termios.c_cflag;
1218 * These are the bits that are used to setup various
1219 * flags in the low level driver. We can ignore the Bfoo
1220 * bits in c_cflag; c_[io]speed will always be set
1221 * appropriately by set_termios() in tty_ioctl.c
1223 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1224 if ((cflag ^ old_termios->c_cflag) == 0 &&
1225 tty->termios.c_ospeed == old_termios->c_ospeed &&
1226 tty->termios.c_ispeed == old_termios->c_ispeed &&
1227 RELEVANT_IFLAG(tty->termios.c_iflag ^ old_termios->c_iflag) == 0) {
1231 uart_change_speed(tty, state, old_termios);
1233 /* Handle transition to B0 status */
1234 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1235 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1236 /* Handle transition away from B0 status */
1237 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1238 unsigned int mask = TIOCM_DTR;
1239 if (!(cflag & CRTSCTS) ||
1240 !test_bit(TTY_THROTTLED, &tty->flags))
1242 uart_set_mctrl(state->uart_port, mask);
1245 /* Handle turning off CRTSCTS */
1246 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1247 spin_lock_irqsave(&state->uart_port->lock, flags);
1248 tty->hw_stopped = 0;
1250 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1252 /* Handle turning on CRTSCTS */
1253 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1254 spin_lock_irqsave(&state->uart_port->lock, flags);
1255 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1256 tty->hw_stopped = 1;
1257 state->uart_port->ops->stop_tx(state->uart_port);
1259 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1264 * In 2.4.5, calls to this will be serialized via the BKL in
1265 * linux/drivers/char/tty_io.c:tty_release()
1266 * linux/drivers/char/tty_io.c:do_tty_handup()
1268 static void uart_close(struct tty_struct *tty, struct file *filp)
1270 struct uart_state *state = tty->driver_data;
1271 struct tty_port *port;
1272 struct uart_port *uport;
1273 unsigned long flags;
1278 uport = state->uart_port;
1279 port = &state->port;
1281 pr_debug("uart_close(%d) called\n", uport->line);
1283 if (tty_port_close_start(port, tty, filp) == 0)
1287 * At this point, we stop accepting input. To do this, we
1288 * disable the receive line status interrupts.
1290 if (port->flags & ASYNC_INITIALIZED) {
1291 unsigned long flags;
1292 spin_lock_irqsave(&uport->lock, flags);
1293 uport->ops->stop_rx(uport);
1294 spin_unlock_irqrestore(&uport->lock, flags);
1296 * Before we drop DTR, make sure the UART transmitter
1297 * has completely drained; this is especially
1298 * important if there is a transmit FIFO!
1300 uart_wait_until_sent(tty, uport->timeout);
1303 mutex_lock(&port->mutex);
1304 uart_shutdown(tty, state);
1305 uart_flush_buffer(tty);
1307 tty_ldisc_flush(tty);
1309 tty_port_tty_set(port, NULL);
1310 spin_lock_irqsave(&port->lock, flags);
1313 if (port->blocked_open) {
1314 spin_unlock_irqrestore(&port->lock, flags);
1315 if (port->close_delay)
1316 msleep_interruptible(
1317 jiffies_to_msecs(port->close_delay));
1318 spin_lock_irqsave(&port->lock, flags);
1319 } else if (!uart_console(uport)) {
1320 spin_unlock_irqrestore(&port->lock, flags);
1321 uart_change_pm(state, 3);
1322 spin_lock_irqsave(&port->lock, flags);
1326 * Wake up anyone trying to open this port.
1328 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1329 clear_bit(ASYNCB_CLOSING, &port->flags);
1330 spin_unlock_irqrestore(&port->lock, flags);
1331 wake_up_interruptible(&port->open_wait);
1332 wake_up_interruptible(&port->close_wait);
1334 mutex_unlock(&port->mutex);
1337 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1339 struct uart_state *state = tty->driver_data;
1340 struct uart_port *port = state->uart_port;
1341 unsigned long char_time, expire;
1343 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1347 * Set the check interval to be 1/5 of the estimated time to
1348 * send a single character, and make it at least 1. The check
1349 * interval should also be less than the timeout.
1351 * Note: we have to use pretty tight timings here to satisfy
1354 char_time = (port->timeout - HZ/50) / port->fifosize;
1355 char_time = char_time / 5;
1358 if (timeout && timeout < char_time)
1359 char_time = timeout;
1362 * If the transmitter hasn't cleared in twice the approximate
1363 * amount of time to send the entire FIFO, it probably won't
1364 * ever clear. This assumes the UART isn't doing flow
1365 * control, which is currently the case. Hence, if it ever
1366 * takes longer than port->timeout, this is probably due to a
1367 * UART bug of some kind. So, we clamp the timeout parameter at
1370 if (timeout == 0 || timeout > 2 * port->timeout)
1371 timeout = 2 * port->timeout;
1373 expire = jiffies + timeout;
1375 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1376 port->line, jiffies, expire);
1379 * Check whether the transmitter is empty every 'char_time'.
1380 * 'timeout' / 'expire' give us the maximum amount of time
1383 while (!port->ops->tx_empty(port)) {
1384 msleep_interruptible(jiffies_to_msecs(char_time));
1385 if (signal_pending(current))
1387 if (time_after(jiffies, expire))
1393 * This is called with the BKL held in
1394 * linux/drivers/char/tty_io.c:do_tty_hangup()
1395 * We're called from the eventd thread, so we can sleep for
1396 * a _short_ time only.
1398 static void uart_hangup(struct tty_struct *tty)
1400 struct uart_state *state = tty->driver_data;
1401 struct tty_port *port = &state->port;
1402 unsigned long flags;
1404 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1406 mutex_lock(&port->mutex);
1407 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1408 uart_flush_buffer(tty);
1409 uart_shutdown(tty, state);
1410 spin_lock_irqsave(&port->lock, flags);
1412 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1413 spin_unlock_irqrestore(&port->lock, flags);
1414 tty_port_tty_set(port, NULL);
1415 wake_up_interruptible(&port->open_wait);
1416 wake_up_interruptible(&port->delta_msr_wait);
1418 mutex_unlock(&port->mutex);
1421 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1426 static void uart_port_shutdown(struct tty_port *port)
1428 struct uart_state *state = container_of(port, struct uart_state, port);
1429 struct uart_port *uport = state->uart_port;
1432 * clear delta_msr_wait queue to avoid mem leaks: we may free
1433 * the irq here so the queue might never be woken up. Note
1434 * that we won't end up waiting on delta_msr_wait again since
1435 * any outstanding file descriptors should be pointing at
1436 * hung_up_tty_fops now.
1438 wake_up_interruptible(&port->delta_msr_wait);
1441 * Free the IRQ and disable the port.
1443 uport->ops->shutdown(uport);
1446 * Ensure that the IRQ handler isn't running on another CPU.
1448 synchronize_irq(uport->irq);
1451 static int uart_carrier_raised(struct tty_port *port)
1453 struct uart_state *state = container_of(port, struct uart_state, port);
1454 struct uart_port *uport = state->uart_port;
1456 spin_lock_irq(&uport->lock);
1457 uport->ops->enable_ms(uport);
1458 mctrl = uport->ops->get_mctrl(uport);
1459 spin_unlock_irq(&uport->lock);
1460 if (mctrl & TIOCM_CAR)
1465 static void uart_dtr_rts(struct tty_port *port, int onoff)
1467 struct uart_state *state = container_of(port, struct uart_state, port);
1468 struct uart_port *uport = state->uart_port;
1471 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1473 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1477 * calls to uart_open are serialised by the BKL in
1478 * fs/char_dev.c:chrdev_open()
1479 * Note that if this fails, then uart_close() _will_ be called.
1481 * In time, we want to scrap the "opening nonpresent ports"
1482 * behaviour and implement an alternative way for setserial
1483 * to set base addresses/ports/types. This will allow us to
1484 * get rid of a certain amount of extra tests.
1486 static int uart_open(struct tty_struct *tty, struct file *filp)
1488 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1489 int retval, line = tty->index;
1490 struct uart_state *state = drv->state + line;
1491 struct tty_port *port = &state->port;
1493 pr_debug("uart_open(%d) called\n", line);
1496 * We take the semaphore here to guarantee that we won't be re-entered
1497 * while allocating the state structure, or while we request any IRQs
1498 * that the driver may need. This also has the nice side-effect that
1499 * it delays the action of uart_hangup, so we can guarantee that
1500 * state->port.tty will always contain something reasonable.
1502 if (mutex_lock_interruptible(&port->mutex)) {
1503 retval = -ERESTARTSYS;
1508 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1514 * Once we set tty->driver_data here, we are guaranteed that
1515 * uart_close() will decrement the driver module use count.
1516 * Any failures from here onwards should not touch the count.
1518 tty->driver_data = state;
1519 state->uart_port->state = state;
1520 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1521 tty_port_tty_set(port, tty);
1524 * If the port is in the middle of closing, bail out now.
1526 if (tty_hung_up_p(filp)) {
1532 * Make sure the device is in D0 state.
1534 if (port->count == 1)
1535 uart_change_pm(state, 0);
1538 * Start up the serial port.
1540 retval = uart_startup(tty, state, 0);
1543 * If we succeeded, wait until the port is ready.
1545 mutex_unlock(&port->mutex);
1547 retval = tty_port_block_til_ready(port, tty, filp);
1553 mutex_unlock(&port->mutex);
1557 static const char *uart_type(struct uart_port *port)
1559 const char *str = NULL;
1561 if (port->ops->type)
1562 str = port->ops->type(port);
1570 #ifdef CONFIG_PROC_FS
1572 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1574 struct uart_state *state = drv->state + i;
1575 struct tty_port *port = &state->port;
1577 struct uart_port *uport = state->uart_port;
1579 unsigned int status;
1585 mmio = uport->iotype >= UPIO_MEM;
1586 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1587 uport->line, uart_type(uport),
1588 mmio ? "mmio:0x" : "port:",
1589 mmio ? (unsigned long long)uport->mapbase
1590 : (unsigned long long)uport->iobase,
1593 if (uport->type == PORT_UNKNOWN) {
1598 if (capable(CAP_SYS_ADMIN)) {
1599 mutex_lock(&port->mutex);
1600 pm_state = state->pm_state;
1602 uart_change_pm(state, 0);
1603 spin_lock_irq(&uport->lock);
1604 status = uport->ops->get_mctrl(uport);
1605 spin_unlock_irq(&uport->lock);
1607 uart_change_pm(state, pm_state);
1608 mutex_unlock(&port->mutex);
1610 seq_printf(m, " tx:%d rx:%d",
1611 uport->icount.tx, uport->icount.rx);
1612 if (uport->icount.frame)
1613 seq_printf(m, " fe:%d",
1614 uport->icount.frame);
1615 if (uport->icount.parity)
1616 seq_printf(m, " pe:%d",
1617 uport->icount.parity);
1618 if (uport->icount.brk)
1619 seq_printf(m, " brk:%d",
1621 if (uport->icount.overrun)
1622 seq_printf(m, " oe:%d",
1623 uport->icount.overrun);
1625 #define INFOBIT(bit, str) \
1626 if (uport->mctrl & (bit)) \
1627 strncat(stat_buf, (str), sizeof(stat_buf) - \
1628 strlen(stat_buf) - 2)
1629 #define STATBIT(bit, str) \
1630 if (status & (bit)) \
1631 strncat(stat_buf, (str), sizeof(stat_buf) - \
1632 strlen(stat_buf) - 2)
1636 INFOBIT(TIOCM_RTS, "|RTS");
1637 STATBIT(TIOCM_CTS, "|CTS");
1638 INFOBIT(TIOCM_DTR, "|DTR");
1639 STATBIT(TIOCM_DSR, "|DSR");
1640 STATBIT(TIOCM_CAR, "|CD");
1641 STATBIT(TIOCM_RNG, "|RI");
1645 seq_puts(m, stat_buf);
1652 static int uart_proc_show(struct seq_file *m, void *v)
1654 struct tty_driver *ttydrv = m->private;
1655 struct uart_driver *drv = ttydrv->driver_state;
1658 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1660 for (i = 0; i < drv->nr; i++)
1661 uart_line_info(m, drv, i);
1665 static int uart_proc_open(struct inode *inode, struct file *file)
1667 return single_open(file, uart_proc_show, PDE(inode)->data);
1670 static const struct file_operations uart_proc_fops = {
1671 .owner = THIS_MODULE,
1672 .open = uart_proc_open,
1674 .llseek = seq_lseek,
1675 .release = single_release,
1679 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1681 * uart_console_write - write a console message to a serial port
1682 * @port: the port to write the message
1683 * @s: array of characters
1684 * @count: number of characters in string to write
1685 * @write: function to write character to port
1687 void uart_console_write(struct uart_port *port, const char *s,
1689 void (*putchar)(struct uart_port *, int))
1693 for (i = 0; i < count; i++, s++) {
1695 putchar(port, '\r');
1699 EXPORT_SYMBOL_GPL(uart_console_write);
1702 * Check whether an invalid uart number has been specified, and
1703 * if so, search for the first available port that does have
1706 struct uart_port * __init
1707 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1709 int idx = co->index;
1711 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1712 ports[idx].membase == NULL))
1713 for (idx = 0; idx < nr; idx++)
1714 if (ports[idx].iobase != 0 ||
1715 ports[idx].membase != NULL)
1724 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1725 * @options: pointer to option string
1726 * @baud: pointer to an 'int' variable for the baud rate.
1727 * @parity: pointer to an 'int' variable for the parity.
1728 * @bits: pointer to an 'int' variable for the number of data bits.
1729 * @flow: pointer to an 'int' variable for the flow control character.
1731 * uart_parse_options decodes a string containing the serial console
1732 * options. The format of the string is <baud><parity><bits><flow>,
1736 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1740 *baud = simple_strtoul(s, NULL, 10);
1741 while (*s >= '0' && *s <= '9')
1750 EXPORT_SYMBOL_GPL(uart_parse_options);
1757 static const struct baud_rates baud_rates[] = {
1758 { 921600, B921600 },
1759 { 460800, B460800 },
1760 { 230400, B230400 },
1761 { 115200, B115200 },
1773 * uart_set_options - setup the serial console parameters
1774 * @port: pointer to the serial ports uart_port structure
1775 * @co: console pointer
1777 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1778 * @bits: number of data bits
1779 * @flow: flow control character - 'r' (rts)
1782 uart_set_options(struct uart_port *port, struct console *co,
1783 int baud, int parity, int bits, int flow)
1785 struct ktermios termios;
1786 static struct ktermios dummy;
1790 * Ensure that the serial console lock is initialised
1793 spin_lock_init(&port->lock);
1794 lockdep_set_class(&port->lock, &port_lock_key);
1796 memset(&termios, 0, sizeof(struct ktermios));
1798 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1801 * Construct a cflag setting.
1803 for (i = 0; baud_rates[i].rate; i++)
1804 if (baud_rates[i].rate <= baud)
1807 termios.c_cflag |= baud_rates[i].cflag;
1810 termios.c_cflag |= CS7;
1812 termios.c_cflag |= CS8;
1816 termios.c_cflag |= PARODD;
1819 termios.c_cflag |= PARENB;
1824 termios.c_cflag |= CRTSCTS;
1827 * some uarts on other side don't support no flow control.
1828 * So we set * DTR in host uart to make them happy
1830 port->mctrl |= TIOCM_DTR;
1832 port->ops->set_termios(port, &termios, &dummy);
1834 * Allow the setting of the UART parameters with a NULL console
1838 co->cflag = termios.c_cflag;
1842 EXPORT_SYMBOL_GPL(uart_set_options);
1843 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1846 * uart_change_pm - set power state of the port
1848 * @state: port descriptor
1849 * @pm_state: new state
1851 * Locking: port->mutex has to be held
1853 static void uart_change_pm(struct uart_state *state, int pm_state)
1855 struct uart_port *port = state->uart_port;
1857 if (state->pm_state != pm_state) {
1859 port->ops->pm(port, pm_state, state->pm_state);
1860 state->pm_state = pm_state;
1865 struct uart_port *port;
1866 struct uart_driver *driver;
1869 static int serial_match_port(struct device *dev, void *data)
1871 struct uart_match *match = data;
1872 struct tty_driver *tty_drv = match->driver->tty_driver;
1873 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1876 return dev->devt == devt; /* Actually, only one tty per port */
1879 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1881 struct uart_state *state = drv->state + uport->line;
1882 struct tty_port *port = &state->port;
1883 struct device *tty_dev;
1884 struct uart_match match = {uport, drv};
1886 mutex_lock(&port->mutex);
1888 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1889 if (device_may_wakeup(tty_dev)) {
1890 if (!enable_irq_wake(uport->irq))
1891 uport->irq_wake = 1;
1892 put_device(tty_dev);
1893 mutex_unlock(&port->mutex);
1896 if (console_suspend_enabled || !uart_console(uport))
1897 uport->suspended = 1;
1899 if (port->flags & ASYNC_INITIALIZED) {
1900 const struct uart_ops *ops = uport->ops;
1903 if (console_suspend_enabled || !uart_console(uport)) {
1904 set_bit(ASYNCB_SUSPENDED, &port->flags);
1905 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1907 spin_lock_irq(&uport->lock);
1908 ops->stop_tx(uport);
1909 ops->set_mctrl(uport, 0);
1910 ops->stop_rx(uport);
1911 spin_unlock_irq(&uport->lock);
1915 * Wait for the transmitter to empty.
1917 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1920 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1922 uport->dev ? dev_name(uport->dev) : "",
1923 uport->dev ? ": " : "",
1925 drv->tty_driver->name_base + uport->line);
1927 if (console_suspend_enabled || !uart_console(uport))
1928 ops->shutdown(uport);
1932 * Disable the console device before suspending.
1934 if (console_suspend_enabled && uart_console(uport))
1935 console_stop(uport->cons);
1937 if (console_suspend_enabled || !uart_console(uport))
1938 uart_change_pm(state, 3);
1940 mutex_unlock(&port->mutex);
1945 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1947 struct uart_state *state = drv->state + uport->line;
1948 struct tty_port *port = &state->port;
1949 struct device *tty_dev;
1950 struct uart_match match = {uport, drv};
1951 struct ktermios termios;
1953 mutex_lock(&port->mutex);
1955 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1956 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1957 if (uport->irq_wake) {
1958 disable_irq_wake(uport->irq);
1959 uport->irq_wake = 0;
1961 mutex_unlock(&port->mutex);
1964 uport->suspended = 0;
1967 * Re-enable the console device after suspending.
1969 if (uart_console(uport)) {
1971 * First try to use the console cflag setting.
1973 memset(&termios, 0, sizeof(struct ktermios));
1974 termios.c_cflag = uport->cons->cflag;
1977 * If that's unset, use the tty termios setting.
1979 if (port->tty && termios.c_cflag == 0)
1980 termios = port->tty->termios;
1982 if (console_suspend_enabled)
1983 uart_change_pm(state, 0);
1984 uport->ops->set_termios(uport, &termios, NULL);
1985 if (console_suspend_enabled)
1986 console_start(uport->cons);
1989 if (port->flags & ASYNC_SUSPENDED) {
1990 const struct uart_ops *ops = uport->ops;
1993 uart_change_pm(state, 0);
1994 spin_lock_irq(&uport->lock);
1995 ops->set_mctrl(uport, 0);
1996 spin_unlock_irq(&uport->lock);
1997 if (console_suspend_enabled || !uart_console(uport)) {
1998 /* Protected by port mutex for now */
1999 struct tty_struct *tty = port->tty;
2000 ret = ops->startup(uport);
2003 uart_change_speed(tty, state, NULL);
2004 spin_lock_irq(&uport->lock);
2005 ops->set_mctrl(uport, uport->mctrl);
2006 ops->start_tx(uport);
2007 spin_unlock_irq(&uport->lock);
2008 set_bit(ASYNCB_INITIALIZED, &port->flags);
2011 * Failed to resume - maybe hardware went away?
2012 * Clear the "initialized" flag so we won't try
2013 * to call the low level drivers shutdown method.
2015 uart_shutdown(tty, state);
2019 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2022 mutex_unlock(&port->mutex);
2028 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2032 switch (port->iotype) {
2034 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2037 snprintf(address, sizeof(address),
2038 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2044 snprintf(address, sizeof(address),
2045 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2048 strlcpy(address, "*unknown*", sizeof(address));
2052 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2053 port->dev ? dev_name(port->dev) : "",
2054 port->dev ? ": " : "",
2056 drv->tty_driver->name_base + port->line,
2057 address, port->irq, uart_type(port));
2061 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2062 struct uart_port *port)
2067 * If there isn't a port here, don't do anything further.
2069 if (!port->iobase && !port->mapbase && !port->membase)
2073 * Now do the auto configuration stuff. Note that config_port
2074 * is expected to claim the resources and map the port for us.
2077 if (port->flags & UPF_AUTO_IRQ)
2078 flags |= UART_CONFIG_IRQ;
2079 if (port->flags & UPF_BOOT_AUTOCONF) {
2080 if (!(port->flags & UPF_FIXED_TYPE)) {
2081 port->type = PORT_UNKNOWN;
2082 flags |= UART_CONFIG_TYPE;
2084 port->ops->config_port(port, flags);
2087 if (port->type != PORT_UNKNOWN) {
2088 unsigned long flags;
2090 uart_report_port(drv, port);
2092 /* Power up port for set_mctrl() */
2093 uart_change_pm(state, 0);
2096 * Ensure that the modem control lines are de-activated.
2097 * keep the DTR setting that is set in uart_set_options()
2098 * We probably don't need a spinlock around this, but
2100 spin_lock_irqsave(&port->lock, flags);
2101 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2102 spin_unlock_irqrestore(&port->lock, flags);
2105 * If this driver supports console, and it hasn't been
2106 * successfully registered yet, try to re-register it.
2107 * It may be that the port was not available.
2109 if (port->cons && !(port->cons->flags & CON_ENABLED))
2110 register_console(port->cons);
2113 * Power down all ports by default, except the
2114 * console if we have one.
2116 if (!uart_console(port))
2117 uart_change_pm(state, 3);
2121 #ifdef CONFIG_CONSOLE_POLL
2123 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2125 struct uart_driver *drv = driver->driver_state;
2126 struct uart_state *state = drv->state + line;
2127 struct uart_port *port;
2133 if (!state || !state->uart_port)
2136 port = state->uart_port;
2137 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2141 uart_parse_options(options, &baud, &parity, &bits, &flow);
2142 return uart_set_options(port, NULL, baud, parity, bits, flow);
2148 static int uart_poll_get_char(struct tty_driver *driver, int line)
2150 struct uart_driver *drv = driver->driver_state;
2151 struct uart_state *state = drv->state + line;
2152 struct uart_port *port;
2154 if (!state || !state->uart_port)
2157 port = state->uart_port;
2158 return port->ops->poll_get_char(port);
2161 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2163 struct uart_driver *drv = driver->driver_state;
2164 struct uart_state *state = drv->state + line;
2165 struct uart_port *port;
2167 if (!state || !state->uart_port)
2170 port = state->uart_port;
2171 port->ops->poll_put_char(port, ch);
2175 static const struct tty_operations uart_ops = {
2177 .close = uart_close,
2178 .write = uart_write,
2179 .put_char = uart_put_char,
2180 .flush_chars = uart_flush_chars,
2181 .write_room = uart_write_room,
2182 .chars_in_buffer= uart_chars_in_buffer,
2183 .flush_buffer = uart_flush_buffer,
2184 .ioctl = uart_ioctl,
2185 .throttle = uart_throttle,
2186 .unthrottle = uart_unthrottle,
2187 .send_xchar = uart_send_xchar,
2188 .set_termios = uart_set_termios,
2189 .set_ldisc = uart_set_ldisc,
2191 .start = uart_start,
2192 .hangup = uart_hangup,
2193 .break_ctl = uart_break_ctl,
2194 .wait_until_sent= uart_wait_until_sent,
2195 #ifdef CONFIG_PROC_FS
2196 .proc_fops = &uart_proc_fops,
2198 .tiocmget = uart_tiocmget,
2199 .tiocmset = uart_tiocmset,
2200 .get_icount = uart_get_icount,
2201 #ifdef CONFIG_CONSOLE_POLL
2202 .poll_init = uart_poll_init,
2203 .poll_get_char = uart_poll_get_char,
2204 .poll_put_char = uart_poll_put_char,
2208 static const struct tty_port_operations uart_port_ops = {
2209 .activate = uart_port_activate,
2210 .shutdown = uart_port_shutdown,
2211 .carrier_raised = uart_carrier_raised,
2212 .dtr_rts = uart_dtr_rts,
2216 * uart_register_driver - register a driver with the uart core layer
2217 * @drv: low level driver structure
2219 * Register a uart driver with the core driver. We in turn register
2220 * with the tty layer, and initialise the core driver per-port state.
2222 * We have a proc file in /proc/tty/driver which is named after the
2225 * drv->port should be NULL, and the per-port structures should be
2226 * registered using uart_add_one_port after this call has succeeded.
2228 int uart_register_driver(struct uart_driver *drv)
2230 struct tty_driver *normal;
2236 * Maybe we should be using a slab cache for this, especially if
2237 * we have a large number of ports to handle.
2239 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2243 normal = alloc_tty_driver(drv->nr);
2247 drv->tty_driver = normal;
2249 normal->driver_name = drv->driver_name;
2250 normal->name = drv->dev_name;
2251 normal->major = drv->major;
2252 normal->minor_start = drv->minor;
2253 normal->type = TTY_DRIVER_TYPE_SERIAL;
2254 normal->subtype = SERIAL_TYPE_NORMAL;
2255 normal->init_termios = tty_std_termios;
2256 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2257 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2258 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2259 normal->driver_state = drv;
2260 tty_set_operations(normal, &uart_ops);
2263 * Initialise the UART state(s).
2265 for (i = 0; i < drv->nr; i++) {
2266 struct uart_state *state = drv->state + i;
2267 struct tty_port *port = &state->port;
2269 tty_port_init(port);
2270 port->ops = &uart_port_ops;
2271 port->close_delay = HZ / 2; /* .5 seconds */
2272 port->closing_wait = 30 * HZ;/* 30 seconds */
2275 retval = tty_register_driver(normal);
2279 put_tty_driver(normal);
2287 * uart_unregister_driver - remove a driver from the uart core layer
2288 * @drv: low level driver structure
2290 * Remove all references to a driver from the core driver. The low
2291 * level driver must have removed all its ports via the
2292 * uart_remove_one_port() if it registered them with uart_add_one_port().
2293 * (ie, drv->port == NULL)
2295 void uart_unregister_driver(struct uart_driver *drv)
2297 struct tty_driver *p = drv->tty_driver;
2298 tty_unregister_driver(p);
2302 drv->tty_driver = NULL;
2305 struct tty_driver *uart_console_device(struct console *co, int *index)
2307 struct uart_driver *p = co->data;
2309 return p->tty_driver;
2313 * uart_add_one_port - attach a driver-defined port structure
2314 * @drv: pointer to the uart low level driver structure for this port
2315 * @uport: uart port structure to use for this port.
2317 * This allows the driver to register its own uart_port structure
2318 * with the core driver. The main purpose is to allow the low
2319 * level uart drivers to expand uart_port, rather than having yet
2320 * more levels of structures.
2322 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2324 struct uart_state *state;
2325 struct tty_port *port;
2327 struct device *tty_dev;
2329 BUG_ON(in_interrupt());
2331 if (uport->line >= drv->nr)
2334 state = drv->state + uport->line;
2335 port = &state->port;
2337 mutex_lock(&port_mutex);
2338 mutex_lock(&port->mutex);
2339 if (state->uart_port) {
2344 state->uart_port = uport;
2345 state->pm_state = -1;
2347 uport->cons = drv->cons;
2348 uport->state = state;
2351 * If this port is a console, then the spinlock is already
2354 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2355 spin_lock_init(&uport->lock);
2356 lockdep_set_class(&uport->lock, &port_lock_key);
2359 uart_configure_port(drv, state, uport);
2362 * Register the port whether it's detected or not. This allows
2363 * setserial to be used to alter this ports parameters.
2365 tty_dev = tty_port_register_device(port, drv->tty_driver, uport->line,
2367 if (likely(!IS_ERR(tty_dev))) {
2368 device_set_wakeup_capable(tty_dev, 1);
2370 printk(KERN_ERR "Cannot register tty device on line %d\n",
2375 * Ensure UPF_DEAD is not set.
2377 uport->flags &= ~UPF_DEAD;
2380 mutex_unlock(&port->mutex);
2381 mutex_unlock(&port_mutex);
2387 * uart_remove_one_port - detach a driver defined port structure
2388 * @drv: pointer to the uart low level driver structure for this port
2389 * @uport: uart port structure for this port
2391 * This unhooks (and hangs up) the specified port structure from the
2392 * core driver. No further calls will be made to the low-level code
2395 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2397 struct uart_state *state = drv->state + uport->line;
2398 struct tty_port *port = &state->port;
2400 BUG_ON(in_interrupt());
2402 if (state->uart_port != uport)
2403 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2404 state->uart_port, uport);
2406 mutex_lock(&port_mutex);
2409 * Mark the port "dead" - this prevents any opens from
2410 * succeeding while we shut down the port.
2412 mutex_lock(&port->mutex);
2413 uport->flags |= UPF_DEAD;
2414 mutex_unlock(&port->mutex);
2417 * Remove the devices from the tty layer
2419 tty_unregister_device(drv->tty_driver, uport->line);
2422 tty_vhangup(port->tty);
2425 * Free the port IO and memory resources, if any.
2427 if (uport->type != PORT_UNKNOWN)
2428 uport->ops->release_port(uport);
2431 * Indicate that there isn't a port here anymore.
2433 uport->type = PORT_UNKNOWN;
2435 state->uart_port = NULL;
2436 mutex_unlock(&port_mutex);
2442 * Are the two ports equivalent?
2444 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2446 if (port1->iotype != port2->iotype)
2449 switch (port1->iotype) {
2451 return (port1->iobase == port2->iobase);
2453 return (port1->iobase == port2->iobase) &&
2454 (port1->hub6 == port2->hub6);
2459 return (port1->mapbase == port2->mapbase);
2463 EXPORT_SYMBOL(uart_match_port);
2466 * uart_handle_dcd_change - handle a change of carrier detect state
2467 * @uport: uart_port structure for the open port
2468 * @status: new carrier detect status, nonzero if active
2470 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2472 struct uart_state *state = uport->state;
2473 struct tty_port *port = &state->port;
2474 struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
2475 struct pps_event_time ts;
2477 if (ld && ld->ops->dcd_change)
2480 uport->icount.dcd++;
2481 #ifdef CONFIG_HARD_PPS
2482 if ((uport->flags & UPF_HARDPPS_CD) && status)
2486 if (port->flags & ASYNC_CHECK_CD) {
2488 wake_up_interruptible(&port->open_wait);
2490 tty_hangup(port->tty);
2493 if (ld && ld->ops->dcd_change)
2494 ld->ops->dcd_change(port->tty, status, &ts);
2496 tty_ldisc_deref(ld);
2498 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2501 * uart_handle_cts_change - handle a change of clear-to-send state
2502 * @uport: uart_port structure for the open port
2503 * @status: new clear to send status, nonzero if active
2505 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2507 struct tty_port *port = &uport->state->port;
2508 struct tty_struct *tty = port->tty;
2510 uport->icount.cts++;
2512 if (tty_port_cts_enabled(port)) {
2513 if (tty->hw_stopped) {
2515 tty->hw_stopped = 0;
2516 uport->ops->start_tx(uport);
2517 uart_write_wakeup(uport);
2521 tty->hw_stopped = 1;
2522 uport->ops->stop_tx(uport);
2527 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2530 * uart_insert_char - push a char to the uart layer
2532 * User is responsible to call tty_flip_buffer_push when they are done with
2535 * @port: corresponding port
2536 * @status: state of the serial port RX buffer (LSR for 8250)
2537 * @overrun: mask of overrun bits in @status
2538 * @ch: character to push
2539 * @flag: flag for the character (see TTY_NORMAL and friends)
2541 void uart_insert_char(struct uart_port *port, unsigned int status,
2542 unsigned int overrun, unsigned int ch, unsigned int flag)
2544 struct tty_struct *tty = port->state->port.tty;
2546 if ((status & port->ignore_status_mask & ~overrun) == 0)
2547 if (tty_insert_flip_char(tty, ch, flag) == 0)
2548 ++port->icount.buf_overrun;
2551 * Overrun is special. Since it's reported immediately,
2552 * it doesn't affect the current character.
2554 if (status & ~port->ignore_status_mask & overrun)
2555 if (tty_insert_flip_char(tty, 0, TTY_OVERRUN) == 0)
2556 ++port->icount.buf_overrun;
2558 EXPORT_SYMBOL_GPL(uart_insert_char);
2560 EXPORT_SYMBOL(uart_write_wakeup);
2561 EXPORT_SYMBOL(uart_register_driver);
2562 EXPORT_SYMBOL(uart_unregister_driver);
2563 EXPORT_SYMBOL(uart_suspend_port);
2564 EXPORT_SYMBOL(uart_resume_port);
2565 EXPORT_SYMBOL(uart_add_one_port);
2566 EXPORT_SYMBOL(uart_remove_one_port);
2568 MODULE_DESCRIPTION("Serial driver core");
2569 MODULE_LICENSE("GPL");