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>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/serial_core.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
42 * This is used to lock changes in serial line configuration.
44 static DEFINE_MUTEX(port_mutex);
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
50 static struct lock_class_key port_lock_key;
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57 static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
60 static void uart_port_shutdown(struct tty_port *port);
63 * This routine is used by the interrupt handler to schedule processing in
64 * the software interrupt portion of the driver.
66 void uart_write_wakeup(struct uart_port *port)
68 struct uart_state *state = port->state;
70 * This means you called this function _after_ the port was
71 * closed. No cookie for you.
74 tty_wakeup(state->port.tty);
77 static void uart_stop(struct tty_struct *tty)
79 struct uart_state *state = tty->driver_data;
80 struct uart_port *port = state->uart_port;
83 spin_lock_irqsave(&port->lock, flags);
84 port->ops->stop_tx(port);
85 spin_unlock_irqrestore(&port->lock, flags);
88 static void __uart_start(struct tty_struct *tty)
90 struct uart_state *state = tty->driver_data;
91 struct uart_port *port = state->uart_port;
93 if (!tty->stopped && !tty->hw_stopped)
94 port->ops->start_tx(port);
97 static void uart_start(struct tty_struct *tty)
99 struct uart_state *state = tty->driver_data;
100 struct uart_port *port = state->uart_port;
103 spin_lock_irqsave(&port->lock, flags);
105 spin_unlock_irqrestore(&port->lock, flags);
109 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
114 spin_lock_irqsave(&port->lock, flags);
116 port->mctrl = (old & ~clear) | set;
117 if (old != port->mctrl)
118 port->ops->set_mctrl(port, port->mctrl);
119 spin_unlock_irqrestore(&port->lock, flags);
122 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
123 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
126 * Startup the port. This will be called once per open. All calls
127 * will be serialised by the per-port mutex.
129 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
132 struct uart_port *uport = state->uart_port;
133 struct tty_port *port = &state->port;
137 if (uport->type == PORT_UNKNOWN)
141 * Make sure the device is in D0 state.
143 uart_change_pm(state, UART_PM_STATE_ON);
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 (uart_console(uport) && tty)
244 uport->cons->cflag = tty->termios.c_cflag;
246 if (!tty || (tty->termios.c_cflag & HUPCL))
247 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
249 uart_port_shutdown(port);
253 * It's possible for shutdown to be called after suspend if we get
254 * a DCD drop (hangup) at just the right time. Clear suspended bit so
255 * we don't try to resume a port that has been shutdown.
257 clear_bit(ASYNCB_SUSPENDED, &port->flags);
260 * Free the transmit buffer page.
262 if (state->xmit.buf) {
263 free_page((unsigned long)state->xmit.buf);
264 state->xmit.buf = NULL;
269 * uart_update_timeout - update per-port FIFO timeout.
270 * @port: uart_port structure describing the port
271 * @cflag: termios cflag value
272 * @baud: speed of the port
274 * Set the port FIFO timeout value. The @cflag value should
275 * reflect the actual hardware settings.
278 uart_update_timeout(struct uart_port *port, unsigned int cflag,
283 /* byte size and parity */
284 switch (cflag & CSIZE) {
305 * The total number of bits to be transmitted in the fifo.
307 bits = bits * port->fifosize;
310 * Figure the timeout to send the above number of bits.
311 * Add .02 seconds of slop
313 port->timeout = (HZ * bits) / baud + HZ/50;
316 EXPORT_SYMBOL(uart_update_timeout);
319 * uart_get_baud_rate - return baud rate for a particular port
320 * @port: uart_port structure describing the port in question.
321 * @termios: desired termios settings.
322 * @old: old termios (or NULL)
323 * @min: minimum acceptable baud rate
324 * @max: maximum acceptable baud rate
326 * Decode the termios structure into a numeric baud rate,
327 * taking account of the magic 38400 baud rate (with spd_*
328 * flags), and mapping the %B0 rate to 9600 baud.
330 * If the new baud rate is invalid, try the old termios setting.
331 * If it's still invalid, we try 9600 baud.
333 * Update the @termios structure to reflect the baud rate
334 * we're actually going to be using. Don't do this for the case
335 * where B0 is requested ("hang up").
338 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
339 struct ktermios *old, unsigned int min, unsigned int max)
341 unsigned int try, baud, altbaud = 38400;
343 upf_t flags = port->flags & UPF_SPD_MASK;
345 if (flags == UPF_SPD_HI)
347 else if (flags == UPF_SPD_VHI)
349 else if (flags == UPF_SPD_SHI)
351 else if (flags == UPF_SPD_WARP)
354 for (try = 0; try < 2; try++) {
355 baud = tty_termios_baud_rate(termios);
358 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
365 * Special case: B0 rate.
372 if (baud >= min && baud <= max)
376 * Oops, the quotient was zero. Try again with
377 * the old baud rate if possible.
379 termios->c_cflag &= ~CBAUD;
381 baud = tty_termios_baud_rate(old);
383 tty_termios_encode_baud_rate(termios,
390 * As a last resort, if the range cannot be met then clip to
391 * the nearest chip supported rate.
395 tty_termios_encode_baud_rate(termios,
398 tty_termios_encode_baud_rate(termios,
402 /* Should never happen */
407 EXPORT_SYMBOL(uart_get_baud_rate);
410 * uart_get_divisor - return uart clock divisor
411 * @port: uart_port structure describing the port.
412 * @baud: desired baud rate
414 * Calculate the uart clock divisor for the port.
417 uart_get_divisor(struct uart_port *port, unsigned int baud)
422 * Old custom speed handling.
424 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
425 quot = port->custom_divisor;
427 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
432 EXPORT_SYMBOL(uart_get_divisor);
434 /* FIXME: Consistent locking policy */
435 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
436 struct ktermios *old_termios)
438 struct tty_port *port = &state->port;
439 struct uart_port *uport = state->uart_port;
440 struct ktermios *termios;
443 * If we have no tty, termios, or the port does not exist,
444 * then we can't set the parameters for this port.
446 if (!tty || uport->type == PORT_UNKNOWN)
449 termios = &tty->termios;
450 uport->ops->set_termios(uport, termios, old_termios);
453 * Set flags based on termios cflag
455 if (termios->c_cflag & CRTSCTS)
456 set_bit(ASYNCB_CTS_FLOW, &port->flags);
458 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
460 if (termios->c_cflag & CLOCAL)
461 clear_bit(ASYNCB_CHECK_CD, &port->flags);
463 set_bit(ASYNCB_CHECK_CD, &port->flags);
466 static inline int __uart_put_char(struct uart_port *port,
467 struct circ_buf *circ, unsigned char c)
475 spin_lock_irqsave(&port->lock, flags);
476 if (uart_circ_chars_free(circ) != 0) {
477 circ->buf[circ->head] = c;
478 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
481 spin_unlock_irqrestore(&port->lock, flags);
485 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
487 struct uart_state *state = tty->driver_data;
489 return __uart_put_char(state->uart_port, &state->xmit, ch);
492 static void uart_flush_chars(struct tty_struct *tty)
497 static int uart_write(struct tty_struct *tty,
498 const unsigned char *buf, int count)
500 struct uart_state *state = tty->driver_data;
501 struct uart_port *port;
502 struct circ_buf *circ;
507 * This means you called this function _after_ the port was
508 * closed. No cookie for you.
515 port = state->uart_port;
521 spin_lock_irqsave(&port->lock, flags);
523 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
528 memcpy(circ->buf + circ->head, buf, c);
529 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
534 spin_unlock_irqrestore(&port->lock, flags);
540 static int uart_write_room(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_free(&state->xmit);
548 spin_unlock_irqrestore(&state->uart_port->lock, flags);
552 static int uart_chars_in_buffer(struct tty_struct *tty)
554 struct uart_state *state = tty->driver_data;
558 spin_lock_irqsave(&state->uart_port->lock, flags);
559 ret = uart_circ_chars_pending(&state->xmit);
560 spin_unlock_irqrestore(&state->uart_port->lock, flags);
564 static void uart_flush_buffer(struct tty_struct *tty)
566 struct uart_state *state = tty->driver_data;
567 struct uart_port *port;
571 * This means you called this function _after_ the port was
572 * closed. No cookie for you.
579 port = state->uart_port;
580 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
582 spin_lock_irqsave(&port->lock, flags);
583 uart_circ_clear(&state->xmit);
584 if (port->ops->flush_buffer)
585 port->ops->flush_buffer(port);
586 spin_unlock_irqrestore(&port->lock, flags);
591 * This function is used to send a high-priority XON/XOFF character to
594 static void uart_send_xchar(struct tty_struct *tty, char ch)
596 struct uart_state *state = tty->driver_data;
597 struct uart_port *port = state->uart_port;
600 if (port->ops->send_xchar)
601 port->ops->send_xchar(port, ch);
603 spin_lock_irqsave(&port->lock, flags);
606 port->ops->start_tx(port);
607 spin_unlock_irqrestore(&port->lock, flags);
611 static void uart_throttle(struct tty_struct *tty)
613 struct uart_state *state = tty->driver_data;
614 struct uart_port *port = state->uart_port;
618 mask |= UPF_SOFT_FLOW;
619 if (tty->termios.c_cflag & CRTSCTS)
620 mask |= UPF_HARD_FLOW;
622 if (port->flags & mask) {
623 port->ops->throttle(port);
624 mask &= ~port->flags;
627 if (mask & UPF_SOFT_FLOW)
628 uart_send_xchar(tty, STOP_CHAR(tty));
630 if (mask & UPF_HARD_FLOW)
631 uart_clear_mctrl(port, TIOCM_RTS);
634 static void uart_unthrottle(struct tty_struct *tty)
636 struct uart_state *state = tty->driver_data;
637 struct uart_port *port = state->uart_port;
641 mask |= UPF_SOFT_FLOW;
642 if (tty->termios.c_cflag & CRTSCTS)
643 mask |= UPF_HARD_FLOW;
645 if (port->flags & mask) {
646 port->ops->unthrottle(port);
647 mask &= ~port->flags;
650 if (mask & UPF_SOFT_FLOW)
651 uart_send_xchar(tty, START_CHAR(tty));
653 if (mask & UPF_HARD_FLOW)
654 uart_set_mctrl(port, TIOCM_RTS);
657 static void do_uart_get_info(struct tty_port *port,
658 struct serial_struct *retinfo)
660 struct uart_state *state = container_of(port, struct uart_state, port);
661 struct uart_port *uport = state->uart_port;
663 memset(retinfo, 0, sizeof(*retinfo));
665 retinfo->type = uport->type;
666 retinfo->line = uport->line;
667 retinfo->port = uport->iobase;
668 if (HIGH_BITS_OFFSET)
669 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
670 retinfo->irq = uport->irq;
671 retinfo->flags = uport->flags;
672 retinfo->xmit_fifo_size = uport->fifosize;
673 retinfo->baud_base = uport->uartclk / 16;
674 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
675 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
676 ASYNC_CLOSING_WAIT_NONE :
677 jiffies_to_msecs(port->closing_wait) / 10;
678 retinfo->custom_divisor = uport->custom_divisor;
679 retinfo->hub6 = uport->hub6;
680 retinfo->io_type = uport->iotype;
681 retinfo->iomem_reg_shift = uport->regshift;
682 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
685 static void uart_get_info(struct tty_port *port,
686 struct serial_struct *retinfo)
688 /* Ensure the state we copy is consistent and no hardware changes
690 mutex_lock(&port->mutex);
691 do_uart_get_info(port, retinfo);
692 mutex_unlock(&port->mutex);
695 static int uart_get_info_user(struct tty_port *port,
696 struct serial_struct __user *retinfo)
698 struct serial_struct tmp;
699 uart_get_info(port, &tmp);
701 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
706 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
707 struct uart_state *state,
708 struct serial_struct *new_info)
710 struct uart_port *uport = state->uart_port;
711 unsigned long new_port;
712 unsigned int change_irq, change_port, closing_wait;
713 unsigned int old_custom_divisor, close_delay;
714 upf_t old_flags, new_flags;
717 new_port = new_info->port;
718 if (HIGH_BITS_OFFSET)
719 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
721 new_info->irq = irq_canonicalize(new_info->irq);
722 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
723 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
724 ASYNC_CLOSING_WAIT_NONE :
725 msecs_to_jiffies(new_info->closing_wait * 10);
728 change_irq = !(uport->flags & UPF_FIXED_PORT)
729 && new_info->irq != uport->irq;
732 * Since changing the 'type' of the port changes its resource
733 * allocations, we should treat type changes the same as
736 change_port = !(uport->flags & UPF_FIXED_PORT)
737 && (new_port != uport->iobase ||
738 (unsigned long)new_info->iomem_base != uport->mapbase ||
739 new_info->hub6 != uport->hub6 ||
740 new_info->io_type != uport->iotype ||
741 new_info->iomem_reg_shift != uport->regshift ||
742 new_info->type != uport->type);
744 old_flags = uport->flags;
745 new_flags = new_info->flags;
746 old_custom_divisor = uport->custom_divisor;
748 if (!capable(CAP_SYS_ADMIN)) {
750 if (change_irq || change_port ||
751 (new_info->baud_base != uport->uartclk / 16) ||
752 (close_delay != port->close_delay) ||
753 (closing_wait != port->closing_wait) ||
754 (new_info->xmit_fifo_size &&
755 new_info->xmit_fifo_size != uport->fifosize) ||
756 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
758 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
759 (new_flags & UPF_USR_MASK));
760 uport->custom_divisor = new_info->custom_divisor;
765 * Ask the low level driver to verify the settings.
767 if (uport->ops->verify_port)
768 retval = uport->ops->verify_port(uport, new_info);
770 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
771 (new_info->baud_base < 9600))
777 if (change_port || change_irq) {
781 * Make sure that we are the sole user of this port.
783 if (tty_port_users(port) > 1)
787 * We need to shutdown the serial port at the old
788 * port/type/irq combination.
790 uart_shutdown(tty, state);
794 unsigned long old_iobase, old_mapbase;
795 unsigned int old_type, old_iotype, old_hub6, old_shift;
797 old_iobase = uport->iobase;
798 old_mapbase = uport->mapbase;
799 old_type = uport->type;
800 old_hub6 = uport->hub6;
801 old_iotype = uport->iotype;
802 old_shift = uport->regshift;
805 * Free and release old regions
807 if (old_type != PORT_UNKNOWN)
808 uport->ops->release_port(uport);
810 uport->iobase = new_port;
811 uport->type = new_info->type;
812 uport->hub6 = new_info->hub6;
813 uport->iotype = new_info->io_type;
814 uport->regshift = new_info->iomem_reg_shift;
815 uport->mapbase = (unsigned long)new_info->iomem_base;
818 * Claim and map the new regions
820 if (uport->type != PORT_UNKNOWN) {
821 retval = uport->ops->request_port(uport);
823 /* Always success - Jean II */
828 * If we fail to request resources for the
829 * new port, try to restore the old settings.
832 uport->iobase = old_iobase;
833 uport->type = old_type;
834 uport->hub6 = old_hub6;
835 uport->iotype = old_iotype;
836 uport->regshift = old_shift;
837 uport->mapbase = old_mapbase;
839 if (old_type != PORT_UNKNOWN) {
840 retval = uport->ops->request_port(uport);
842 * If we failed to restore the old settings,
846 uport->type = PORT_UNKNOWN;
854 /* Added to return the correct error -Ram Gupta */
860 uport->irq = new_info->irq;
861 if (!(uport->flags & UPF_FIXED_PORT))
862 uport->uartclk = new_info->baud_base * 16;
863 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
864 (new_flags & UPF_CHANGE_MASK);
865 uport->custom_divisor = new_info->custom_divisor;
866 port->close_delay = close_delay;
867 port->closing_wait = closing_wait;
868 if (new_info->xmit_fifo_size)
869 uport->fifosize = new_info->xmit_fifo_size;
870 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
874 if (uport->type == PORT_UNKNOWN)
876 if (port->flags & ASYNC_INITIALIZED) {
877 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
878 old_custom_divisor != uport->custom_divisor) {
880 * If they're setting up a custom divisor or speed,
881 * instead of clearing it, then bitch about it. No
882 * need to rate-limit; it's CAP_SYS_ADMIN only.
884 if (uport->flags & UPF_SPD_MASK) {
887 dev_notice(uport->dev,
888 "%s sets custom speed on %s. This is deprecated.\n",
890 tty_name(port->tty, buf));
892 uart_change_speed(tty, state, NULL);
895 retval = uart_startup(tty, state, 1);
900 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
901 struct serial_struct __user *newinfo)
903 struct serial_struct new_serial;
904 struct tty_port *port = &state->port;
907 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
911 * This semaphore protects port->count. It is also
912 * very useful to prevent opens. Also, take the
913 * port configuration semaphore to make sure that a
914 * module insertion/removal doesn't change anything
917 mutex_lock(&port->mutex);
918 retval = uart_set_info(tty, port, state, &new_serial);
919 mutex_unlock(&port->mutex);
924 * uart_get_lsr_info - get line status register info
925 * @tty: tty associated with the UART
926 * @state: UART being queried
927 * @value: returned modem value
929 * Note: uart_ioctl protects us against hangups.
931 static int uart_get_lsr_info(struct tty_struct *tty,
932 struct uart_state *state, unsigned int __user *value)
934 struct uart_port *uport = state->uart_port;
937 result = uport->ops->tx_empty(uport);
940 * If we're about to load something into the transmit
941 * register, we'll pretend the transmitter isn't empty to
942 * avoid a race condition (depending on when the transmit
943 * interrupt happens).
946 ((uart_circ_chars_pending(&state->xmit) > 0) &&
947 !tty->stopped && !tty->hw_stopped))
948 result &= ~TIOCSER_TEMT;
950 return put_user(result, value);
953 static int uart_tiocmget(struct tty_struct *tty)
955 struct uart_state *state = tty->driver_data;
956 struct tty_port *port = &state->port;
957 struct uart_port *uport = state->uart_port;
960 mutex_lock(&port->mutex);
961 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
962 result = uport->mctrl;
963 spin_lock_irq(&uport->lock);
964 result |= uport->ops->get_mctrl(uport);
965 spin_unlock_irq(&uport->lock);
967 mutex_unlock(&port->mutex);
973 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
975 struct uart_state *state = tty->driver_data;
976 struct uart_port *uport = state->uart_port;
977 struct tty_port *port = &state->port;
980 mutex_lock(&port->mutex);
981 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
982 uart_update_mctrl(uport, set, clear);
985 mutex_unlock(&port->mutex);
989 static int uart_break_ctl(struct tty_struct *tty, int break_state)
991 struct uart_state *state = tty->driver_data;
992 struct tty_port *port = &state->port;
993 struct uart_port *uport = state->uart_port;
995 mutex_lock(&port->mutex);
997 if (uport->type != PORT_UNKNOWN)
998 uport->ops->break_ctl(uport, break_state);
1000 mutex_unlock(&port->mutex);
1004 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1006 struct uart_port *uport = state->uart_port;
1007 struct tty_port *port = &state->port;
1010 if (!capable(CAP_SYS_ADMIN))
1014 * Take the per-port semaphore. This prevents count from
1015 * changing, and hence any extra opens of the port while
1016 * we're auto-configuring.
1018 if (mutex_lock_interruptible(&port->mutex))
1019 return -ERESTARTSYS;
1022 if (tty_port_users(port) == 1) {
1023 uart_shutdown(tty, state);
1026 * If we already have a port type configured,
1027 * we must release its resources.
1029 if (uport->type != PORT_UNKNOWN)
1030 uport->ops->release_port(uport);
1032 flags = UART_CONFIG_TYPE;
1033 if (uport->flags & UPF_AUTO_IRQ)
1034 flags |= UART_CONFIG_IRQ;
1037 * This will claim the ports resources if
1040 uport->ops->config_port(uport, flags);
1042 ret = uart_startup(tty, state, 1);
1044 mutex_unlock(&port->mutex);
1048 static void uart_enable_ms(struct uart_port *uport)
1051 * Force modem status interrupts on
1053 if (uport->ops->enable_ms)
1054 uport->ops->enable_ms(uport);
1058 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1059 * - mask passed in arg for lines of interest
1060 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1061 * Caller should use TIOCGICOUNT to see which one it was
1063 * FIXME: This wants extracting into a common all driver implementation
1064 * of TIOCMWAIT using tty_port.
1067 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1069 struct uart_port *uport = state->uart_port;
1070 struct tty_port *port = &state->port;
1071 DECLARE_WAITQUEUE(wait, current);
1072 struct uart_icount cprev, cnow;
1076 * note the counters on entry
1078 spin_lock_irq(&uport->lock);
1079 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1080 uart_enable_ms(uport);
1081 spin_unlock_irq(&uport->lock);
1083 add_wait_queue(&port->delta_msr_wait, &wait);
1085 spin_lock_irq(&uport->lock);
1086 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1087 spin_unlock_irq(&uport->lock);
1089 set_current_state(TASK_INTERRUPTIBLE);
1091 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1092 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1093 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1094 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1101 /* see if a signal did it */
1102 if (signal_pending(current)) {
1110 current->state = TASK_RUNNING;
1111 remove_wait_queue(&port->delta_msr_wait, &wait);
1117 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1118 * Return: write counters to the user passed counter struct
1119 * NB: both 1->0 and 0->1 transitions are counted except for
1120 * RI where only 0->1 is counted.
1122 static int uart_get_icount(struct tty_struct *tty,
1123 struct serial_icounter_struct *icount)
1125 struct uart_state *state = tty->driver_data;
1126 struct uart_icount cnow;
1127 struct uart_port *uport = state->uart_port;
1129 spin_lock_irq(&uport->lock);
1130 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1131 spin_unlock_irq(&uport->lock);
1133 icount->cts = cnow.cts;
1134 icount->dsr = cnow.dsr;
1135 icount->rng = cnow.rng;
1136 icount->dcd = cnow.dcd;
1137 icount->rx = cnow.rx;
1138 icount->tx = cnow.tx;
1139 icount->frame = cnow.frame;
1140 icount->overrun = cnow.overrun;
1141 icount->parity = cnow.parity;
1142 icount->brk = cnow.brk;
1143 icount->buf_overrun = cnow.buf_overrun;
1149 * Called via sys_ioctl. We can use spin_lock_irq() here.
1152 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1155 struct uart_state *state = tty->driver_data;
1156 struct tty_port *port = &state->port;
1157 void __user *uarg = (void __user *)arg;
1158 int ret = -ENOIOCTLCMD;
1162 * These ioctls don't rely on the hardware to be present.
1166 ret = uart_get_info_user(port, uarg);
1170 ret = uart_set_info_user(tty, state, uarg);
1174 ret = uart_do_autoconfig(tty, state);
1177 case TIOCSERGWILD: /* obsolete */
1178 case TIOCSERSWILD: /* obsolete */
1183 if (ret != -ENOIOCTLCMD)
1186 if (tty->flags & (1 << TTY_IO_ERROR)) {
1192 * The following should only be used when hardware is present.
1196 ret = uart_wait_modem_status(state, arg);
1200 if (ret != -ENOIOCTLCMD)
1203 mutex_lock(&port->mutex);
1205 if (tty->flags & (1 << TTY_IO_ERROR)) {
1211 * All these rely on hardware being present and need to be
1212 * protected against the tty being hung up.
1215 case TIOCSERGETLSR: /* Get line status register */
1216 ret = uart_get_lsr_info(tty, state, uarg);
1220 struct uart_port *uport = state->uart_port;
1221 if (uport->ops->ioctl)
1222 ret = uport->ops->ioctl(uport, cmd, arg);
1227 mutex_unlock(&port->mutex);
1232 static void uart_set_ldisc(struct tty_struct *tty)
1234 struct uart_state *state = tty->driver_data;
1235 struct uart_port *uport = state->uart_port;
1237 if (uport->ops->set_ldisc)
1238 uport->ops->set_ldisc(uport, tty->termios.c_line);
1241 static void uart_set_termios(struct tty_struct *tty,
1242 struct ktermios *old_termios)
1244 struct uart_state *state = tty->driver_data;
1245 struct uart_port *uport = state->uart_port;
1246 unsigned long flags;
1247 unsigned int cflag = tty->termios.c_cflag;
1248 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1249 bool sw_changed = false;
1252 * Drivers doing software flow control also need to know
1253 * about changes to these input settings.
1255 if (uport->flags & UPF_SOFT_FLOW) {
1256 iflag_mask |= IXANY|IXON|IXOFF;
1258 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1259 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1263 * These are the bits that are used to setup various
1264 * flags in the low level driver. We can ignore the Bfoo
1265 * bits in c_cflag; c_[io]speed will always be set
1266 * appropriately by set_termios() in tty_ioctl.c
1268 if ((cflag ^ old_termios->c_cflag) == 0 &&
1269 tty->termios.c_ospeed == old_termios->c_ospeed &&
1270 tty->termios.c_ispeed == old_termios->c_ispeed &&
1271 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1276 uart_change_speed(tty, state, old_termios);
1277 /* reload cflag from termios; port driver may have overriden flags */
1278 cflag = tty->termios.c_cflag;
1280 /* Handle transition to B0 status */
1281 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1282 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1283 /* Handle transition away from B0 status */
1284 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1285 unsigned int mask = TIOCM_DTR;
1286 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1288 uart_set_mctrl(uport, mask);
1292 * If the port is doing h/w assisted flow control, do nothing.
1293 * We assume that tty->hw_stopped has never been set.
1295 if (uport->flags & UPF_HARD_FLOW)
1298 /* Handle turning off CRTSCTS */
1299 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1300 spin_lock_irqsave(&uport->lock, flags);
1301 tty->hw_stopped = 0;
1303 spin_unlock_irqrestore(&uport->lock, flags);
1305 /* Handle turning on CRTSCTS */
1306 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1307 spin_lock_irqsave(&uport->lock, flags);
1308 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1309 tty->hw_stopped = 1;
1310 uport->ops->stop_tx(uport);
1312 spin_unlock_irqrestore(&uport->lock, flags);
1317 * Calls to uart_close() are serialised via the tty_lock in
1318 * drivers/tty/tty_io.c:tty_release()
1319 * drivers/tty/tty_io.c:do_tty_hangup()
1320 * This runs from a workqueue and can sleep for a _short_ time only.
1322 static void uart_close(struct tty_struct *tty, struct file *filp)
1324 struct uart_state *state = tty->driver_data;
1325 struct tty_port *port;
1326 struct uart_port *uport;
1327 unsigned long flags;
1332 uport = state->uart_port;
1333 port = &state->port;
1335 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1337 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1341 * At this point, we stop accepting input. To do this, we
1342 * disable the receive line status interrupts.
1344 if (port->flags & ASYNC_INITIALIZED) {
1345 unsigned long flags;
1346 spin_lock_irqsave(&uport->lock, flags);
1347 uport->ops->stop_rx(uport);
1348 spin_unlock_irqrestore(&uport->lock, flags);
1350 * Before we drop DTR, make sure the UART transmitter
1351 * has completely drained; this is especially
1352 * important if there is a transmit FIFO!
1354 uart_wait_until_sent(tty, uport->timeout);
1357 mutex_lock(&port->mutex);
1358 uart_shutdown(tty, state);
1359 uart_flush_buffer(tty);
1361 tty_ldisc_flush(tty);
1363 tty_port_tty_set(port, NULL);
1365 spin_lock_irqsave(&port->lock, flags);
1367 if (port->blocked_open) {
1368 spin_unlock_irqrestore(&port->lock, flags);
1369 if (port->close_delay)
1370 msleep_interruptible(
1371 jiffies_to_msecs(port->close_delay));
1372 spin_lock_irqsave(&port->lock, flags);
1373 } else if (!uart_console(uport)) {
1374 spin_unlock_irqrestore(&port->lock, flags);
1375 uart_change_pm(state, UART_PM_STATE_OFF);
1376 spin_lock_irqsave(&port->lock, flags);
1380 * Wake up anyone trying to open this port.
1382 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1383 clear_bit(ASYNCB_CLOSING, &port->flags);
1384 spin_unlock_irqrestore(&port->lock, flags);
1385 wake_up_interruptible(&port->open_wait);
1386 wake_up_interruptible(&port->close_wait);
1388 mutex_unlock(&port->mutex);
1391 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1393 struct uart_state *state = tty->driver_data;
1394 struct uart_port *port = state->uart_port;
1395 unsigned long char_time, expire;
1397 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1401 * Set the check interval to be 1/5 of the estimated time to
1402 * send a single character, and make it at least 1. The check
1403 * interval should also be less than the timeout.
1405 * Note: we have to use pretty tight timings here to satisfy
1408 char_time = (port->timeout - HZ/50) / port->fifosize;
1409 char_time = char_time / 5;
1412 if (timeout && timeout < char_time)
1413 char_time = timeout;
1416 * If the transmitter hasn't cleared in twice the approximate
1417 * amount of time to send the entire FIFO, it probably won't
1418 * ever clear. This assumes the UART isn't doing flow
1419 * control, which is currently the case. Hence, if it ever
1420 * takes longer than port->timeout, this is probably due to a
1421 * UART bug of some kind. So, we clamp the timeout parameter at
1424 if (timeout == 0 || timeout > 2 * port->timeout)
1425 timeout = 2 * port->timeout;
1427 expire = jiffies + timeout;
1429 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1430 port->line, jiffies, expire);
1433 * Check whether the transmitter is empty every 'char_time'.
1434 * 'timeout' / 'expire' give us the maximum amount of time
1437 while (!port->ops->tx_empty(port)) {
1438 msleep_interruptible(jiffies_to_msecs(char_time));
1439 if (signal_pending(current))
1441 if (time_after(jiffies, expire))
1447 * Calls to uart_hangup() are serialised by the tty_lock in
1448 * drivers/tty/tty_io.c:do_tty_hangup()
1449 * This runs from a workqueue and can sleep for a _short_ time only.
1451 static void uart_hangup(struct tty_struct *tty)
1453 struct uart_state *state = tty->driver_data;
1454 struct tty_port *port = &state->port;
1455 unsigned long flags;
1457 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1459 mutex_lock(&port->mutex);
1460 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1461 uart_flush_buffer(tty);
1462 uart_shutdown(tty, state);
1463 spin_lock_irqsave(&port->lock, flags);
1465 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1466 spin_unlock_irqrestore(&port->lock, flags);
1467 tty_port_tty_set(port, NULL);
1468 if (!uart_console(state->uart_port))
1469 uart_change_pm(state, UART_PM_STATE_OFF);
1470 wake_up_interruptible(&port->open_wait);
1471 wake_up_interruptible(&port->delta_msr_wait);
1473 mutex_unlock(&port->mutex);
1476 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1481 static void uart_port_shutdown(struct tty_port *port)
1483 struct uart_state *state = container_of(port, struct uart_state, port);
1484 struct uart_port *uport = state->uart_port;
1487 * clear delta_msr_wait queue to avoid mem leaks: we may free
1488 * the irq here so the queue might never be woken up. Note
1489 * that we won't end up waiting on delta_msr_wait again since
1490 * any outstanding file descriptors should be pointing at
1491 * hung_up_tty_fops now.
1493 wake_up_interruptible(&port->delta_msr_wait);
1496 * Free the IRQ and disable the port.
1498 uport->ops->shutdown(uport);
1501 * Ensure that the IRQ handler isn't running on another CPU.
1503 synchronize_irq(uport->irq);
1506 static int uart_carrier_raised(struct tty_port *port)
1508 struct uart_state *state = container_of(port, struct uart_state, port);
1509 struct uart_port *uport = state->uart_port;
1511 spin_lock_irq(&uport->lock);
1512 uart_enable_ms(uport);
1513 mctrl = uport->ops->get_mctrl(uport);
1514 spin_unlock_irq(&uport->lock);
1515 if (mctrl & TIOCM_CAR)
1520 static void uart_dtr_rts(struct tty_port *port, int onoff)
1522 struct uart_state *state = container_of(port, struct uart_state, port);
1523 struct uart_port *uport = state->uart_port;
1526 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1528 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1532 * Calls to uart_open are serialised by the tty_lock in
1533 * drivers/tty/tty_io.c:tty_open()
1534 * Note that if this fails, then uart_close() _will_ be called.
1536 * In time, we want to scrap the "opening nonpresent ports"
1537 * behaviour and implement an alternative way for setserial
1538 * to set base addresses/ports/types. This will allow us to
1539 * get rid of a certain amount of extra tests.
1541 static int uart_open(struct tty_struct *tty, struct file *filp)
1543 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1544 int retval, line = tty->index;
1545 struct uart_state *state = drv->state + line;
1546 struct tty_port *port = &state->port;
1548 pr_debug("uart_open(%d) called\n", line);
1551 * We take the semaphore here to guarantee that we won't be re-entered
1552 * while allocating the state structure, or while we request any IRQs
1553 * that the driver may need. This also has the nice side-effect that
1554 * it delays the action of uart_hangup, so we can guarantee that
1555 * state->port.tty will always contain something reasonable.
1557 if (mutex_lock_interruptible(&port->mutex)) {
1558 retval = -ERESTARTSYS;
1563 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1569 * Once we set tty->driver_data here, we are guaranteed that
1570 * uart_close() will decrement the driver module use count.
1571 * Any failures from here onwards should not touch the count.
1573 tty->driver_data = state;
1574 state->uart_port->state = state;
1575 state->port.low_latency =
1576 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1577 tty_port_tty_set(port, tty);
1580 * Start up the serial port.
1582 retval = uart_startup(tty, state, 0);
1585 * If we succeeded, wait until the port is ready.
1587 mutex_unlock(&port->mutex);
1589 retval = tty_port_block_til_ready(port, tty, filp);
1595 mutex_unlock(&port->mutex);
1599 static const char *uart_type(struct uart_port *port)
1601 const char *str = NULL;
1603 if (port->ops->type)
1604 str = port->ops->type(port);
1612 #ifdef CONFIG_PROC_FS
1614 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1616 struct uart_state *state = drv->state + i;
1617 struct tty_port *port = &state->port;
1618 enum uart_pm_state pm_state;
1619 struct uart_port *uport = state->uart_port;
1621 unsigned int status;
1627 mmio = uport->iotype >= UPIO_MEM;
1628 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1629 uport->line, uart_type(uport),
1630 mmio ? "mmio:0x" : "port:",
1631 mmio ? (unsigned long long)uport->mapbase
1632 : (unsigned long long)uport->iobase,
1635 if (uport->type == PORT_UNKNOWN) {
1640 if (capable(CAP_SYS_ADMIN)) {
1641 mutex_lock(&port->mutex);
1642 pm_state = state->pm_state;
1643 if (pm_state != UART_PM_STATE_ON)
1644 uart_change_pm(state, UART_PM_STATE_ON);
1645 spin_lock_irq(&uport->lock);
1646 status = uport->ops->get_mctrl(uport);
1647 spin_unlock_irq(&uport->lock);
1648 if (pm_state != UART_PM_STATE_ON)
1649 uart_change_pm(state, pm_state);
1650 mutex_unlock(&port->mutex);
1652 seq_printf(m, " tx:%d rx:%d",
1653 uport->icount.tx, uport->icount.rx);
1654 if (uport->icount.frame)
1655 seq_printf(m, " fe:%d",
1656 uport->icount.frame);
1657 if (uport->icount.parity)
1658 seq_printf(m, " pe:%d",
1659 uport->icount.parity);
1660 if (uport->icount.brk)
1661 seq_printf(m, " brk:%d",
1663 if (uport->icount.overrun)
1664 seq_printf(m, " oe:%d",
1665 uport->icount.overrun);
1667 #define INFOBIT(bit, str) \
1668 if (uport->mctrl & (bit)) \
1669 strncat(stat_buf, (str), sizeof(stat_buf) - \
1670 strlen(stat_buf) - 2)
1671 #define STATBIT(bit, str) \
1672 if (status & (bit)) \
1673 strncat(stat_buf, (str), sizeof(stat_buf) - \
1674 strlen(stat_buf) - 2)
1678 INFOBIT(TIOCM_RTS, "|RTS");
1679 STATBIT(TIOCM_CTS, "|CTS");
1680 INFOBIT(TIOCM_DTR, "|DTR");
1681 STATBIT(TIOCM_DSR, "|DSR");
1682 STATBIT(TIOCM_CAR, "|CD");
1683 STATBIT(TIOCM_RNG, "|RI");
1687 seq_puts(m, stat_buf);
1694 static int uart_proc_show(struct seq_file *m, void *v)
1696 struct tty_driver *ttydrv = m->private;
1697 struct uart_driver *drv = ttydrv->driver_state;
1700 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1702 for (i = 0; i < drv->nr; i++)
1703 uart_line_info(m, drv, i);
1707 static int uart_proc_open(struct inode *inode, struct file *file)
1709 return single_open(file, uart_proc_show, PDE_DATA(inode));
1712 static const struct file_operations uart_proc_fops = {
1713 .owner = THIS_MODULE,
1714 .open = uart_proc_open,
1716 .llseek = seq_lseek,
1717 .release = single_release,
1721 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1723 * uart_console_write - write a console message to a serial port
1724 * @port: the port to write the message
1725 * @s: array of characters
1726 * @count: number of characters in string to write
1727 * @write: function to write character to port
1729 void uart_console_write(struct uart_port *port, const char *s,
1731 void (*putchar)(struct uart_port *, int))
1735 for (i = 0; i < count; i++, s++) {
1737 putchar(port, '\r');
1741 EXPORT_SYMBOL_GPL(uart_console_write);
1744 * Check whether an invalid uart number has been specified, and
1745 * if so, search for the first available port that does have
1748 struct uart_port * __init
1749 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1751 int idx = co->index;
1753 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1754 ports[idx].membase == NULL))
1755 for (idx = 0; idx < nr; idx++)
1756 if (ports[idx].iobase != 0 ||
1757 ports[idx].membase != NULL)
1766 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1767 * @options: pointer to option string
1768 * @baud: pointer to an 'int' variable for the baud rate.
1769 * @parity: pointer to an 'int' variable for the parity.
1770 * @bits: pointer to an 'int' variable for the number of data bits.
1771 * @flow: pointer to an 'int' variable for the flow control character.
1773 * uart_parse_options decodes a string containing the serial console
1774 * options. The format of the string is <baud><parity><bits><flow>,
1778 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1782 *baud = simple_strtoul(s, NULL, 10);
1783 while (*s >= '0' && *s <= '9')
1792 EXPORT_SYMBOL_GPL(uart_parse_options);
1799 static const struct baud_rates baud_rates[] = {
1800 { 921600, B921600 },
1801 { 460800, B460800 },
1802 { 230400, B230400 },
1803 { 115200, B115200 },
1815 * uart_set_options - setup the serial console parameters
1816 * @port: pointer to the serial ports uart_port structure
1817 * @co: console pointer
1819 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1820 * @bits: number of data bits
1821 * @flow: flow control character - 'r' (rts)
1824 uart_set_options(struct uart_port *port, struct console *co,
1825 int baud, int parity, int bits, int flow)
1827 struct ktermios termios;
1828 static struct ktermios dummy;
1832 * Ensure that the serial console lock is initialised
1834 * If this port is a console, then the spinlock is already
1837 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1838 spin_lock_init(&port->lock);
1839 lockdep_set_class(&port->lock, &port_lock_key);
1842 memset(&termios, 0, sizeof(struct ktermios));
1844 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1847 * Construct a cflag setting.
1849 for (i = 0; baud_rates[i].rate; i++)
1850 if (baud_rates[i].rate <= baud)
1853 termios.c_cflag |= baud_rates[i].cflag;
1856 termios.c_cflag |= CS7;
1858 termios.c_cflag |= CS8;
1862 termios.c_cflag |= PARODD;
1865 termios.c_cflag |= PARENB;
1870 termios.c_cflag |= CRTSCTS;
1873 * some uarts on other side don't support no flow control.
1874 * So we set * DTR in host uart to make them happy
1876 port->mctrl |= TIOCM_DTR;
1878 port->ops->set_termios(port, &termios, &dummy);
1880 * Allow the setting of the UART parameters with a NULL console
1884 co->cflag = termios.c_cflag;
1888 EXPORT_SYMBOL_GPL(uart_set_options);
1889 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1892 * uart_change_pm - set power state of the port
1894 * @state: port descriptor
1895 * @pm_state: new state
1897 * Locking: port->mutex has to be held
1899 static void uart_change_pm(struct uart_state *state,
1900 enum uart_pm_state pm_state)
1902 struct uart_port *port = state->uart_port;
1904 if (state->pm_state != pm_state) {
1906 port->ops->pm(port, pm_state, state->pm_state);
1907 state->pm_state = pm_state;
1912 struct uart_port *port;
1913 struct uart_driver *driver;
1916 static int serial_match_port(struct device *dev, void *data)
1918 struct uart_match *match = data;
1919 struct tty_driver *tty_drv = match->driver->tty_driver;
1920 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1923 return dev->devt == devt; /* Actually, only one tty per port */
1926 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1928 struct uart_state *state = drv->state + uport->line;
1929 struct tty_port *port = &state->port;
1930 struct device *tty_dev;
1931 struct uart_match match = {uport, drv};
1933 mutex_lock(&port->mutex);
1935 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1936 if (device_may_wakeup(tty_dev)) {
1937 if (!enable_irq_wake(uport->irq))
1938 uport->irq_wake = 1;
1939 put_device(tty_dev);
1940 mutex_unlock(&port->mutex);
1943 put_device(tty_dev);
1945 if (console_suspend_enabled || !uart_console(uport))
1946 uport->suspended = 1;
1948 if (port->flags & ASYNC_INITIALIZED) {
1949 const struct uart_ops *ops = uport->ops;
1952 if (console_suspend_enabled || !uart_console(uport)) {
1953 set_bit(ASYNCB_SUSPENDED, &port->flags);
1954 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1956 spin_lock_irq(&uport->lock);
1957 ops->stop_tx(uport);
1958 ops->set_mctrl(uport, 0);
1959 ops->stop_rx(uport);
1960 spin_unlock_irq(&uport->lock);
1964 * Wait for the transmitter to empty.
1966 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1969 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
1971 drv->tty_driver->name_base + uport->line);
1973 if (console_suspend_enabled || !uart_console(uport))
1974 ops->shutdown(uport);
1978 * Disable the console device before suspending.
1980 if (console_suspend_enabled && uart_console(uport))
1981 console_stop(uport->cons);
1983 if (console_suspend_enabled || !uart_console(uport))
1984 uart_change_pm(state, UART_PM_STATE_OFF);
1986 mutex_unlock(&port->mutex);
1991 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1993 struct uart_state *state = drv->state + uport->line;
1994 struct tty_port *port = &state->port;
1995 struct device *tty_dev;
1996 struct uart_match match = {uport, drv};
1997 struct ktermios termios;
1999 mutex_lock(&port->mutex);
2001 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2002 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2003 if (uport->irq_wake) {
2004 disable_irq_wake(uport->irq);
2005 uport->irq_wake = 0;
2007 put_device(tty_dev);
2008 mutex_unlock(&port->mutex);
2011 put_device(tty_dev);
2012 uport->suspended = 0;
2015 * Re-enable the console device after suspending.
2017 if (uart_console(uport)) {
2019 * First try to use the console cflag setting.
2021 memset(&termios, 0, sizeof(struct ktermios));
2022 termios.c_cflag = uport->cons->cflag;
2025 * If that's unset, use the tty termios setting.
2027 if (port->tty && termios.c_cflag == 0)
2028 termios = port->tty->termios;
2030 if (console_suspend_enabled)
2031 uart_change_pm(state, UART_PM_STATE_ON);
2032 uport->ops->set_termios(uport, &termios, NULL);
2033 if (console_suspend_enabled)
2034 console_start(uport->cons);
2037 if (port->flags & ASYNC_SUSPENDED) {
2038 const struct uart_ops *ops = uport->ops;
2041 uart_change_pm(state, UART_PM_STATE_ON);
2042 spin_lock_irq(&uport->lock);
2043 ops->set_mctrl(uport, 0);
2044 spin_unlock_irq(&uport->lock);
2045 if (console_suspend_enabled || !uart_console(uport)) {
2046 /* Protected by port mutex for now */
2047 struct tty_struct *tty = port->tty;
2048 ret = ops->startup(uport);
2051 uart_change_speed(tty, state, NULL);
2052 spin_lock_irq(&uport->lock);
2053 ops->set_mctrl(uport, uport->mctrl);
2054 ops->start_tx(uport);
2055 spin_unlock_irq(&uport->lock);
2056 set_bit(ASYNCB_INITIALIZED, &port->flags);
2059 * Failed to resume - maybe hardware went away?
2060 * Clear the "initialized" flag so we won't try
2061 * to call the low level drivers shutdown method.
2063 uart_shutdown(tty, state);
2067 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2070 mutex_unlock(&port->mutex);
2076 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2080 switch (port->iotype) {
2082 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2085 snprintf(address, sizeof(address),
2086 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2092 snprintf(address, sizeof(address),
2093 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2096 strlcpy(address, "*unknown*", sizeof(address));
2100 dev_info(port->dev, "%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2102 drv->tty_driver->name_base + port->line,
2103 address, port->irq, port->uartclk / 16, uart_type(port));
2107 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2108 struct uart_port *port)
2113 * If there isn't a port here, don't do anything further.
2115 if (!port->iobase && !port->mapbase && !port->membase)
2119 * Now do the auto configuration stuff. Note that config_port
2120 * is expected to claim the resources and map the port for us.
2123 if (port->flags & UPF_AUTO_IRQ)
2124 flags |= UART_CONFIG_IRQ;
2125 if (port->flags & UPF_BOOT_AUTOCONF) {
2126 if (!(port->flags & UPF_FIXED_TYPE)) {
2127 port->type = PORT_UNKNOWN;
2128 flags |= UART_CONFIG_TYPE;
2130 port->ops->config_port(port, flags);
2133 if (port->type != PORT_UNKNOWN) {
2134 unsigned long flags;
2136 uart_report_port(drv, port);
2138 /* Power up port for set_mctrl() */
2139 uart_change_pm(state, UART_PM_STATE_ON);
2142 * Ensure that the modem control lines are de-activated.
2143 * keep the DTR setting that is set in uart_set_options()
2144 * We probably don't need a spinlock around this, but
2146 spin_lock_irqsave(&port->lock, flags);
2147 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2148 spin_unlock_irqrestore(&port->lock, flags);
2151 * If this driver supports console, and it hasn't been
2152 * successfully registered yet, try to re-register it.
2153 * It may be that the port was not available.
2155 if (port->cons && !(port->cons->flags & CON_ENABLED))
2156 register_console(port->cons);
2159 * Power down all ports by default, except the
2160 * console if we have one.
2162 if (!uart_console(port))
2163 uart_change_pm(state, UART_PM_STATE_OFF);
2167 #ifdef CONFIG_CONSOLE_POLL
2169 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2171 struct uart_driver *drv = driver->driver_state;
2172 struct uart_state *state = drv->state + line;
2173 struct uart_port *port;
2180 if (!state || !state->uart_port)
2183 port = state->uart_port;
2184 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2187 if (port->ops->poll_init) {
2188 struct tty_port *tport = &state->port;
2191 mutex_lock(&tport->mutex);
2193 * We don't set ASYNCB_INITIALIZED as we only initialized the
2194 * hw, e.g. state->xmit is still uninitialized.
2196 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2197 ret = port->ops->poll_init(port);
2198 mutex_unlock(&tport->mutex);
2204 uart_parse_options(options, &baud, &parity, &bits, &flow);
2205 return uart_set_options(port, NULL, baud, parity, bits, flow);
2211 static int uart_poll_get_char(struct tty_driver *driver, int line)
2213 struct uart_driver *drv = driver->driver_state;
2214 struct uart_state *state = drv->state + line;
2215 struct uart_port *port;
2217 if (!state || !state->uart_port)
2220 port = state->uart_port;
2221 return port->ops->poll_get_char(port);
2224 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2226 struct uart_driver *drv = driver->driver_state;
2227 struct uart_state *state = drv->state + line;
2228 struct uart_port *port;
2230 if (!state || !state->uart_port)
2233 port = state->uart_port;
2236 port->ops->poll_put_char(port, '\r');
2237 port->ops->poll_put_char(port, ch);
2241 static const struct tty_operations uart_ops = {
2243 .close = uart_close,
2244 .write = uart_write,
2245 .put_char = uart_put_char,
2246 .flush_chars = uart_flush_chars,
2247 .write_room = uart_write_room,
2248 .chars_in_buffer= uart_chars_in_buffer,
2249 .flush_buffer = uart_flush_buffer,
2250 .ioctl = uart_ioctl,
2251 .throttle = uart_throttle,
2252 .unthrottle = uart_unthrottle,
2253 .send_xchar = uart_send_xchar,
2254 .set_termios = uart_set_termios,
2255 .set_ldisc = uart_set_ldisc,
2257 .start = uart_start,
2258 .hangup = uart_hangup,
2259 .break_ctl = uart_break_ctl,
2260 .wait_until_sent= uart_wait_until_sent,
2261 #ifdef CONFIG_PROC_FS
2262 .proc_fops = &uart_proc_fops,
2264 .tiocmget = uart_tiocmget,
2265 .tiocmset = uart_tiocmset,
2266 .get_icount = uart_get_icount,
2267 #ifdef CONFIG_CONSOLE_POLL
2268 .poll_init = uart_poll_init,
2269 .poll_get_char = uart_poll_get_char,
2270 .poll_put_char = uart_poll_put_char,
2274 static const struct tty_port_operations uart_port_ops = {
2275 .activate = uart_port_activate,
2276 .shutdown = uart_port_shutdown,
2277 .carrier_raised = uart_carrier_raised,
2278 .dtr_rts = uart_dtr_rts,
2282 * uart_register_driver - register a driver with the uart core layer
2283 * @drv: low level driver structure
2285 * Register a uart driver with the core driver. We in turn register
2286 * with the tty layer, and initialise the core driver per-port state.
2288 * We have a proc file in /proc/tty/driver which is named after the
2291 * drv->port should be NULL, and the per-port structures should be
2292 * registered using uart_add_one_port after this call has succeeded.
2294 int uart_register_driver(struct uart_driver *drv)
2296 struct tty_driver *normal;
2302 * Maybe we should be using a slab cache for this, especially if
2303 * we have a large number of ports to handle.
2305 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2309 normal = alloc_tty_driver(drv->nr);
2313 drv->tty_driver = normal;
2315 normal->driver_name = drv->driver_name;
2316 normal->name = drv->dev_name;
2317 normal->major = drv->major;
2318 normal->minor_start = drv->minor;
2319 normal->type = TTY_DRIVER_TYPE_SERIAL;
2320 normal->subtype = SERIAL_TYPE_NORMAL;
2321 normal->init_termios = tty_std_termios;
2322 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2323 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2324 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2325 normal->driver_state = drv;
2326 tty_set_operations(normal, &uart_ops);
2329 * Initialise the UART state(s).
2331 for (i = 0; i < drv->nr; i++) {
2332 struct uart_state *state = drv->state + i;
2333 struct tty_port *port = &state->port;
2335 tty_port_init(port);
2336 port->ops = &uart_port_ops;
2337 port->close_delay = HZ / 2; /* .5 seconds */
2338 port->closing_wait = 30 * HZ;/* 30 seconds */
2341 retval = tty_register_driver(normal);
2345 for (i = 0; i < drv->nr; i++)
2346 tty_port_destroy(&drv->state[i].port);
2347 put_tty_driver(normal);
2355 * uart_unregister_driver - remove a driver from the uart core layer
2356 * @drv: low level driver structure
2358 * Remove all references to a driver from the core driver. The low
2359 * level driver must have removed all its ports via the
2360 * uart_remove_one_port() if it registered them with uart_add_one_port().
2361 * (ie, drv->port == NULL)
2363 void uart_unregister_driver(struct uart_driver *drv)
2365 struct tty_driver *p = drv->tty_driver;
2368 tty_unregister_driver(p);
2370 for (i = 0; i < drv->nr; i++)
2371 tty_port_destroy(&drv->state[i].port);
2374 drv->tty_driver = NULL;
2377 struct tty_driver *uart_console_device(struct console *co, int *index)
2379 struct uart_driver *p = co->data;
2381 return p->tty_driver;
2384 static ssize_t uart_get_attr_uartclk(struct device *dev,
2385 struct device_attribute *attr, char *buf)
2387 struct serial_struct tmp;
2388 struct tty_port *port = dev_get_drvdata(dev);
2390 uart_get_info(port, &tmp);
2391 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2394 static ssize_t uart_get_attr_type(struct device *dev,
2395 struct device_attribute *attr, char *buf)
2397 struct serial_struct tmp;
2398 struct tty_port *port = dev_get_drvdata(dev);
2400 uart_get_info(port, &tmp);
2401 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2403 static ssize_t uart_get_attr_line(struct device *dev,
2404 struct device_attribute *attr, char *buf)
2406 struct serial_struct tmp;
2407 struct tty_port *port = dev_get_drvdata(dev);
2409 uart_get_info(port, &tmp);
2410 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2413 static ssize_t uart_get_attr_port(struct device *dev,
2414 struct device_attribute *attr, char *buf)
2416 struct serial_struct tmp;
2417 struct tty_port *port = dev_get_drvdata(dev);
2418 unsigned long ioaddr;
2420 uart_get_info(port, &tmp);
2422 if (HIGH_BITS_OFFSET)
2423 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2424 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2427 static ssize_t uart_get_attr_irq(struct device *dev,
2428 struct device_attribute *attr, char *buf)
2430 struct serial_struct tmp;
2431 struct tty_port *port = dev_get_drvdata(dev);
2433 uart_get_info(port, &tmp);
2434 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2437 static ssize_t uart_get_attr_flags(struct device *dev,
2438 struct device_attribute *attr, char *buf)
2440 struct serial_struct tmp;
2441 struct tty_port *port = dev_get_drvdata(dev);
2443 uart_get_info(port, &tmp);
2444 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2447 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2448 struct device_attribute *attr, char *buf)
2450 struct serial_struct tmp;
2451 struct tty_port *port = dev_get_drvdata(dev);
2453 uart_get_info(port, &tmp);
2454 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2458 static ssize_t uart_get_attr_close_delay(struct device *dev,
2459 struct device_attribute *attr, char *buf)
2461 struct serial_struct tmp;
2462 struct tty_port *port = dev_get_drvdata(dev);
2464 uart_get_info(port, &tmp);
2465 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2469 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2470 struct device_attribute *attr, char *buf)
2472 struct serial_struct tmp;
2473 struct tty_port *port = dev_get_drvdata(dev);
2475 uart_get_info(port, &tmp);
2476 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2479 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2480 struct device_attribute *attr, char *buf)
2482 struct serial_struct tmp;
2483 struct tty_port *port = dev_get_drvdata(dev);
2485 uart_get_info(port, &tmp);
2486 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2489 static ssize_t uart_get_attr_io_type(struct device *dev,
2490 struct device_attribute *attr, char *buf)
2492 struct serial_struct tmp;
2493 struct tty_port *port = dev_get_drvdata(dev);
2495 uart_get_info(port, &tmp);
2496 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2499 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2500 struct device_attribute *attr, char *buf)
2502 struct serial_struct tmp;
2503 struct tty_port *port = dev_get_drvdata(dev);
2505 uart_get_info(port, &tmp);
2506 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2509 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2510 struct device_attribute *attr, char *buf)
2512 struct serial_struct tmp;
2513 struct tty_port *port = dev_get_drvdata(dev);
2515 uart_get_info(port, &tmp);
2516 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2519 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2520 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2521 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2522 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2523 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2524 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2525 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2526 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2527 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2528 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2529 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2530 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2531 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2533 static struct attribute *tty_dev_attrs[] = {
2534 &dev_attr_type.attr,
2535 &dev_attr_line.attr,
2536 &dev_attr_port.attr,
2538 &dev_attr_flags.attr,
2539 &dev_attr_xmit_fifo_size.attr,
2540 &dev_attr_uartclk.attr,
2541 &dev_attr_close_delay.attr,
2542 &dev_attr_closing_wait.attr,
2543 &dev_attr_custom_divisor.attr,
2544 &dev_attr_io_type.attr,
2545 &dev_attr_iomem_base.attr,
2546 &dev_attr_iomem_reg_shift.attr,
2550 static const struct attribute_group tty_dev_attr_group = {
2551 .attrs = tty_dev_attrs,
2555 * uart_add_one_port - attach a driver-defined port structure
2556 * @drv: pointer to the uart low level driver structure for this port
2557 * @uport: uart port structure to use for this port.
2559 * This allows the driver to register its own uart_port structure
2560 * with the core driver. The main purpose is to allow the low
2561 * level uart drivers to expand uart_port, rather than having yet
2562 * more levels of structures.
2564 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2566 struct uart_state *state;
2567 struct tty_port *port;
2569 struct device *tty_dev;
2572 BUG_ON(in_interrupt());
2574 if (uport->line >= drv->nr)
2577 state = drv->state + uport->line;
2578 port = &state->port;
2580 mutex_lock(&port_mutex);
2581 mutex_lock(&port->mutex);
2582 if (state->uart_port) {
2587 state->uart_port = uport;
2588 state->pm_state = UART_PM_STATE_UNDEFINED;
2590 uport->cons = drv->cons;
2591 uport->state = state;
2594 * If this port is a console, then the spinlock is already
2597 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2598 spin_lock_init(&uport->lock);
2599 lockdep_set_class(&uport->lock, &port_lock_key);
2601 if (uport->cons && uport->dev)
2602 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2604 uart_configure_port(drv, state, uport);
2607 if (uport->attr_group)
2610 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2612 if (!uport->tty_groups) {
2616 uport->tty_groups[0] = &tty_dev_attr_group;
2617 if (uport->attr_group)
2618 uport->tty_groups[1] = uport->attr_group;
2621 * Register the port whether it's detected or not. This allows
2622 * setserial to be used to alter this port's parameters.
2624 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2625 uport->line, uport->dev, port, uport->tty_groups);
2626 if (likely(!IS_ERR(tty_dev))) {
2627 device_set_wakeup_capable(tty_dev, 1);
2629 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2634 * Ensure UPF_DEAD is not set.
2636 uport->flags &= ~UPF_DEAD;
2639 mutex_unlock(&port->mutex);
2640 mutex_unlock(&port_mutex);
2646 * uart_remove_one_port - detach a driver defined port structure
2647 * @drv: pointer to the uart low level driver structure for this port
2648 * @uport: uart port structure for this port
2650 * This unhooks (and hangs up) the specified port structure from the
2651 * core driver. No further calls will be made to the low-level code
2654 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2656 struct uart_state *state = drv->state + uport->line;
2657 struct tty_port *port = &state->port;
2658 struct tty_struct *tty;
2661 BUG_ON(in_interrupt());
2663 if (state->uart_port != uport)
2664 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2665 state->uart_port, uport);
2667 mutex_lock(&port_mutex);
2670 * Mark the port "dead" - this prevents any opens from
2671 * succeeding while we shut down the port.
2673 mutex_lock(&port->mutex);
2674 if (!state->uart_port) {
2675 mutex_unlock(&port->mutex);
2679 uport->flags |= UPF_DEAD;
2680 mutex_unlock(&port->mutex);
2683 * Remove the devices from the tty layer
2685 tty_unregister_device(drv->tty_driver, uport->line);
2687 tty = tty_port_tty_get(port);
2689 tty_vhangup(port->tty);
2694 * If the port is used as a console, unregister it
2696 if (uart_console(uport))
2697 unregister_console(uport->cons);
2700 * Free the port IO and memory resources, if any.
2702 if (uport->type != PORT_UNKNOWN)
2703 uport->ops->release_port(uport);
2704 kfree(uport->tty_groups);
2707 * Indicate that there isn't a port here anymore.
2709 uport->type = PORT_UNKNOWN;
2711 state->uart_port = NULL;
2713 mutex_unlock(&port_mutex);
2719 * Are the two ports equivalent?
2721 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2723 if (port1->iotype != port2->iotype)
2726 switch (port1->iotype) {
2728 return (port1->iobase == port2->iobase);
2730 return (port1->iobase == port2->iobase) &&
2731 (port1->hub6 == port2->hub6);
2736 return (port1->mapbase == port2->mapbase);
2740 EXPORT_SYMBOL(uart_match_port);
2743 * uart_handle_dcd_change - handle a change of carrier detect state
2744 * @uport: uart_port structure for the open port
2745 * @status: new carrier detect status, nonzero if active
2747 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2749 struct tty_port *port = &uport->state->port;
2750 struct tty_struct *tty = port->tty;
2751 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2754 if (ld->ops->dcd_change)
2755 ld->ops->dcd_change(tty, status);
2756 tty_ldisc_deref(ld);
2759 uport->icount.dcd++;
2761 if (port->flags & ASYNC_CHECK_CD) {
2763 wake_up_interruptible(&port->open_wait);
2768 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2771 * uart_handle_cts_change - handle a change of clear-to-send state
2772 * @uport: uart_port structure for the open port
2773 * @status: new clear to send status, nonzero if active
2775 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2777 struct tty_port *port = &uport->state->port;
2778 struct tty_struct *tty = port->tty;
2780 uport->icount.cts++;
2782 if (tty_port_cts_enabled(port)) {
2783 if (tty->hw_stopped) {
2785 tty->hw_stopped = 0;
2786 uport->ops->start_tx(uport);
2787 uart_write_wakeup(uport);
2791 tty->hw_stopped = 1;
2792 uport->ops->stop_tx(uport);
2797 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2800 * uart_insert_char - push a char to the uart layer
2802 * User is responsible to call tty_flip_buffer_push when they are done with
2805 * @port: corresponding port
2806 * @status: state of the serial port RX buffer (LSR for 8250)
2807 * @overrun: mask of overrun bits in @status
2808 * @ch: character to push
2809 * @flag: flag for the character (see TTY_NORMAL and friends)
2811 void uart_insert_char(struct uart_port *port, unsigned int status,
2812 unsigned int overrun, unsigned int ch, unsigned int flag)
2814 struct tty_port *tport = &port->state->port;
2816 if ((status & port->ignore_status_mask & ~overrun) == 0)
2817 if (tty_insert_flip_char(tport, ch, flag) == 0)
2818 ++port->icount.buf_overrun;
2821 * Overrun is special. Since it's reported immediately,
2822 * it doesn't affect the current character.
2824 if (status & ~port->ignore_status_mask & overrun)
2825 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2826 ++port->icount.buf_overrun;
2828 EXPORT_SYMBOL_GPL(uart_insert_char);
2830 EXPORT_SYMBOL(uart_write_wakeup);
2831 EXPORT_SYMBOL(uart_register_driver);
2832 EXPORT_SYMBOL(uart_unregister_driver);
2833 EXPORT_SYMBOL(uart_suspend_port);
2834 EXPORT_SYMBOL(uart_resume_port);
2835 EXPORT_SYMBOL(uart_add_one_port);
2836 EXPORT_SYMBOL(uart_remove_one_port);
2838 MODULE_DESCRIPTION("Serial driver core");
2839 MODULE_LICENSE("GPL");