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) {
654 uart_send_xchar(tty, START_CHAR(tty));
657 if (mask & UPF_HARD_FLOW)
658 uart_set_mctrl(port, TIOCM_RTS);
661 static void do_uart_get_info(struct tty_port *port,
662 struct serial_struct *retinfo)
664 struct uart_state *state = container_of(port, struct uart_state, port);
665 struct uart_port *uport = state->uart_port;
667 memset(retinfo, 0, sizeof(*retinfo));
669 retinfo->type = uport->type;
670 retinfo->line = uport->line;
671 retinfo->port = uport->iobase;
672 if (HIGH_BITS_OFFSET)
673 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
674 retinfo->irq = uport->irq;
675 retinfo->flags = uport->flags;
676 retinfo->xmit_fifo_size = uport->fifosize;
677 retinfo->baud_base = uport->uartclk / 16;
678 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
679 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
680 ASYNC_CLOSING_WAIT_NONE :
681 jiffies_to_msecs(port->closing_wait) / 10;
682 retinfo->custom_divisor = uport->custom_divisor;
683 retinfo->hub6 = uport->hub6;
684 retinfo->io_type = uport->iotype;
685 retinfo->iomem_reg_shift = uport->regshift;
686 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
689 static void uart_get_info(struct tty_port *port,
690 struct serial_struct *retinfo)
692 /* Ensure the state we copy is consistent and no hardware changes
694 mutex_lock(&port->mutex);
695 do_uart_get_info(port, retinfo);
696 mutex_unlock(&port->mutex);
699 static int uart_get_info_user(struct tty_port *port,
700 struct serial_struct __user *retinfo)
702 struct serial_struct tmp;
703 uart_get_info(port, &tmp);
705 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
710 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
711 struct uart_state *state,
712 struct serial_struct *new_info)
714 struct uart_port *uport = state->uart_port;
715 unsigned long new_port;
716 unsigned int change_irq, change_port, closing_wait;
717 unsigned int old_custom_divisor, close_delay;
718 upf_t old_flags, new_flags;
721 new_port = new_info->port;
722 if (HIGH_BITS_OFFSET)
723 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
725 new_info->irq = irq_canonicalize(new_info->irq);
726 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
727 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
728 ASYNC_CLOSING_WAIT_NONE :
729 msecs_to_jiffies(new_info->closing_wait * 10);
732 change_irq = !(uport->flags & UPF_FIXED_PORT)
733 && new_info->irq != uport->irq;
736 * Since changing the 'type' of the port changes its resource
737 * allocations, we should treat type changes the same as
740 change_port = !(uport->flags & UPF_FIXED_PORT)
741 && (new_port != uport->iobase ||
742 (unsigned long)new_info->iomem_base != uport->mapbase ||
743 new_info->hub6 != uport->hub6 ||
744 new_info->io_type != uport->iotype ||
745 new_info->iomem_reg_shift != uport->regshift ||
746 new_info->type != uport->type);
748 old_flags = uport->flags;
749 new_flags = new_info->flags;
750 old_custom_divisor = uport->custom_divisor;
752 if (!capable(CAP_SYS_ADMIN)) {
754 if (change_irq || change_port ||
755 (new_info->baud_base != uport->uartclk / 16) ||
756 (close_delay != port->close_delay) ||
757 (closing_wait != port->closing_wait) ||
758 (new_info->xmit_fifo_size &&
759 new_info->xmit_fifo_size != uport->fifosize) ||
760 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
762 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
763 (new_flags & UPF_USR_MASK));
764 uport->custom_divisor = new_info->custom_divisor;
769 * Ask the low level driver to verify the settings.
771 if (uport->ops->verify_port)
772 retval = uport->ops->verify_port(uport, new_info);
774 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
775 (new_info->baud_base < 9600))
781 if (change_port || change_irq) {
785 * Make sure that we are the sole user of this port.
787 if (tty_port_users(port) > 1)
791 * We need to shutdown the serial port at the old
792 * port/type/irq combination.
794 uart_shutdown(tty, state);
798 unsigned long old_iobase, old_mapbase;
799 unsigned int old_type, old_iotype, old_hub6, old_shift;
801 old_iobase = uport->iobase;
802 old_mapbase = uport->mapbase;
803 old_type = uport->type;
804 old_hub6 = uport->hub6;
805 old_iotype = uport->iotype;
806 old_shift = uport->regshift;
809 * Free and release old regions
811 if (old_type != PORT_UNKNOWN)
812 uport->ops->release_port(uport);
814 uport->iobase = new_port;
815 uport->type = new_info->type;
816 uport->hub6 = new_info->hub6;
817 uport->iotype = new_info->io_type;
818 uport->regshift = new_info->iomem_reg_shift;
819 uport->mapbase = (unsigned long)new_info->iomem_base;
822 * Claim and map the new regions
824 if (uport->type != PORT_UNKNOWN) {
825 retval = uport->ops->request_port(uport);
827 /* Always success - Jean II */
832 * If we fail to request resources for the
833 * new port, try to restore the old settings.
836 uport->iobase = old_iobase;
837 uport->type = old_type;
838 uport->hub6 = old_hub6;
839 uport->iotype = old_iotype;
840 uport->regshift = old_shift;
841 uport->mapbase = old_mapbase;
843 if (old_type != PORT_UNKNOWN) {
844 retval = uport->ops->request_port(uport);
846 * If we failed to restore the old settings,
850 uport->type = PORT_UNKNOWN;
858 /* Added to return the correct error -Ram Gupta */
864 uport->irq = new_info->irq;
865 if (!(uport->flags & UPF_FIXED_PORT))
866 uport->uartclk = new_info->baud_base * 16;
867 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
868 (new_flags & UPF_CHANGE_MASK);
869 uport->custom_divisor = new_info->custom_divisor;
870 port->close_delay = close_delay;
871 port->closing_wait = closing_wait;
872 if (new_info->xmit_fifo_size)
873 uport->fifosize = new_info->xmit_fifo_size;
874 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
878 if (uport->type == PORT_UNKNOWN)
880 if (port->flags & ASYNC_INITIALIZED) {
881 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
882 old_custom_divisor != uport->custom_divisor) {
884 * If they're setting up a custom divisor or speed,
885 * instead of clearing it, then bitch about it. No
886 * need to rate-limit; it's CAP_SYS_ADMIN only.
888 if (uport->flags & UPF_SPD_MASK) {
891 dev_notice(uport->dev,
892 "%s sets custom speed on %s. This is deprecated.\n",
894 tty_name(port->tty, buf));
896 uart_change_speed(tty, state, NULL);
899 retval = uart_startup(tty, state, 1);
904 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
905 struct serial_struct __user *newinfo)
907 struct serial_struct new_serial;
908 struct tty_port *port = &state->port;
911 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
915 * This semaphore protects port->count. It is also
916 * very useful to prevent opens. Also, take the
917 * port configuration semaphore to make sure that a
918 * module insertion/removal doesn't change anything
921 mutex_lock(&port->mutex);
922 retval = uart_set_info(tty, port, state, &new_serial);
923 mutex_unlock(&port->mutex);
928 * uart_get_lsr_info - get line status register info
929 * @tty: tty associated with the UART
930 * @state: UART being queried
931 * @value: returned modem value
933 * Note: uart_ioctl protects us against hangups.
935 static int uart_get_lsr_info(struct tty_struct *tty,
936 struct uart_state *state, unsigned int __user *value)
938 struct uart_port *uport = state->uart_port;
941 result = uport->ops->tx_empty(uport);
944 * If we're about to load something into the transmit
945 * register, we'll pretend the transmitter isn't empty to
946 * avoid a race condition (depending on when the transmit
947 * interrupt happens).
950 ((uart_circ_chars_pending(&state->xmit) > 0) &&
951 !tty->stopped && !tty->hw_stopped))
952 result &= ~TIOCSER_TEMT;
954 return put_user(result, value);
957 static int uart_tiocmget(struct tty_struct *tty)
959 struct uart_state *state = tty->driver_data;
960 struct tty_port *port = &state->port;
961 struct uart_port *uport = state->uart_port;
964 mutex_lock(&port->mutex);
965 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
966 result = uport->mctrl;
967 spin_lock_irq(&uport->lock);
968 result |= uport->ops->get_mctrl(uport);
969 spin_unlock_irq(&uport->lock);
971 mutex_unlock(&port->mutex);
977 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
979 struct uart_state *state = tty->driver_data;
980 struct uart_port *uport = state->uart_port;
981 struct tty_port *port = &state->port;
984 mutex_lock(&port->mutex);
985 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
986 uart_update_mctrl(uport, set, clear);
989 mutex_unlock(&port->mutex);
993 static int uart_break_ctl(struct tty_struct *tty, int break_state)
995 struct uart_state *state = tty->driver_data;
996 struct tty_port *port = &state->port;
997 struct uart_port *uport = state->uart_port;
999 mutex_lock(&port->mutex);
1001 if (uport->type != PORT_UNKNOWN)
1002 uport->ops->break_ctl(uport, break_state);
1004 mutex_unlock(&port->mutex);
1008 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1010 struct uart_port *uport = state->uart_port;
1011 struct tty_port *port = &state->port;
1014 if (!capable(CAP_SYS_ADMIN))
1018 * Take the per-port semaphore. This prevents count from
1019 * changing, and hence any extra opens of the port while
1020 * we're auto-configuring.
1022 if (mutex_lock_interruptible(&port->mutex))
1023 return -ERESTARTSYS;
1026 if (tty_port_users(port) == 1) {
1027 uart_shutdown(tty, state);
1030 * If we already have a port type configured,
1031 * we must release its resources.
1033 if (uport->type != PORT_UNKNOWN)
1034 uport->ops->release_port(uport);
1036 flags = UART_CONFIG_TYPE;
1037 if (uport->flags & UPF_AUTO_IRQ)
1038 flags |= UART_CONFIG_IRQ;
1041 * This will claim the ports resources if
1044 uport->ops->config_port(uport, flags);
1046 ret = uart_startup(tty, state, 1);
1048 mutex_unlock(&port->mutex);
1052 static void uart_enable_ms(struct uart_port *uport)
1055 * Force modem status interrupts on
1057 if (uport->ops->enable_ms)
1058 uport->ops->enable_ms(uport);
1062 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1063 * - mask passed in arg for lines of interest
1064 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1065 * Caller should use TIOCGICOUNT to see which one it was
1067 * FIXME: This wants extracting into a common all driver implementation
1068 * of TIOCMWAIT using tty_port.
1071 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1073 struct uart_port *uport = state->uart_port;
1074 struct tty_port *port = &state->port;
1075 DECLARE_WAITQUEUE(wait, current);
1076 struct uart_icount cprev, cnow;
1080 * note the counters on entry
1082 spin_lock_irq(&uport->lock);
1083 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1084 uart_enable_ms(uport);
1085 spin_unlock_irq(&uport->lock);
1087 add_wait_queue(&port->delta_msr_wait, &wait);
1089 spin_lock_irq(&uport->lock);
1090 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1091 spin_unlock_irq(&uport->lock);
1093 set_current_state(TASK_INTERRUPTIBLE);
1095 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1096 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1097 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1098 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1105 /* see if a signal did it */
1106 if (signal_pending(current)) {
1114 current->state = TASK_RUNNING;
1115 remove_wait_queue(&port->delta_msr_wait, &wait);
1121 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1122 * Return: write counters to the user passed counter struct
1123 * NB: both 1->0 and 0->1 transitions are counted except for
1124 * RI where only 0->1 is counted.
1126 static int uart_get_icount(struct tty_struct *tty,
1127 struct serial_icounter_struct *icount)
1129 struct uart_state *state = tty->driver_data;
1130 struct uart_icount cnow;
1131 struct uart_port *uport = state->uart_port;
1133 spin_lock_irq(&uport->lock);
1134 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1135 spin_unlock_irq(&uport->lock);
1137 icount->cts = cnow.cts;
1138 icount->dsr = cnow.dsr;
1139 icount->rng = cnow.rng;
1140 icount->dcd = cnow.dcd;
1141 icount->rx = cnow.rx;
1142 icount->tx = cnow.tx;
1143 icount->frame = cnow.frame;
1144 icount->overrun = cnow.overrun;
1145 icount->parity = cnow.parity;
1146 icount->brk = cnow.brk;
1147 icount->buf_overrun = cnow.buf_overrun;
1153 * Called via sys_ioctl. We can use spin_lock_irq() here.
1156 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1159 struct uart_state *state = tty->driver_data;
1160 struct tty_port *port = &state->port;
1161 void __user *uarg = (void __user *)arg;
1162 int ret = -ENOIOCTLCMD;
1166 * These ioctls don't rely on the hardware to be present.
1170 ret = uart_get_info_user(port, uarg);
1174 ret = uart_set_info_user(tty, state, uarg);
1178 ret = uart_do_autoconfig(tty, state);
1181 case TIOCSERGWILD: /* obsolete */
1182 case TIOCSERSWILD: /* obsolete */
1187 if (ret != -ENOIOCTLCMD)
1190 if (tty->flags & (1 << TTY_IO_ERROR)) {
1196 * The following should only be used when hardware is present.
1200 ret = uart_wait_modem_status(state, arg);
1204 if (ret != -ENOIOCTLCMD)
1207 mutex_lock(&port->mutex);
1209 if (tty->flags & (1 << TTY_IO_ERROR)) {
1215 * All these rely on hardware being present and need to be
1216 * protected against the tty being hung up.
1219 case TIOCSERGETLSR: /* Get line status register */
1220 ret = uart_get_lsr_info(tty, state, uarg);
1224 struct uart_port *uport = state->uart_port;
1225 if (uport->ops->ioctl)
1226 ret = uport->ops->ioctl(uport, cmd, arg);
1231 mutex_unlock(&port->mutex);
1236 static void uart_set_ldisc(struct tty_struct *tty)
1238 struct uart_state *state = tty->driver_data;
1239 struct uart_port *uport = state->uart_port;
1241 if (uport->ops->set_ldisc)
1242 uport->ops->set_ldisc(uport, tty->termios.c_line);
1245 static void uart_set_termios(struct tty_struct *tty,
1246 struct ktermios *old_termios)
1248 struct uart_state *state = tty->driver_data;
1249 struct uart_port *uport = state->uart_port;
1250 unsigned long flags;
1251 unsigned int cflag = tty->termios.c_cflag;
1252 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1253 bool sw_changed = false;
1256 * Drivers doing software flow control also need to know
1257 * about changes to these input settings.
1259 if (uport->flags & UPF_SOFT_FLOW) {
1260 iflag_mask |= IXANY|IXON|IXOFF;
1262 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1263 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1267 * These are the bits that are used to setup various
1268 * flags in the low level driver. We can ignore the Bfoo
1269 * bits in c_cflag; c_[io]speed will always be set
1270 * appropriately by set_termios() in tty_ioctl.c
1272 if ((cflag ^ old_termios->c_cflag) == 0 &&
1273 tty->termios.c_ospeed == old_termios->c_ospeed &&
1274 tty->termios.c_ispeed == old_termios->c_ispeed &&
1275 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1280 uart_change_speed(tty, state, old_termios);
1281 /* reload cflag from termios; port driver may have overriden flags */
1282 cflag = tty->termios.c_cflag;
1284 /* Handle transition to B0 status */
1285 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1286 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1287 /* Handle transition away from B0 status */
1288 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1289 unsigned int mask = TIOCM_DTR;
1290 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1292 uart_set_mctrl(uport, mask);
1296 * If the port is doing h/w assisted flow control, do nothing.
1297 * We assume that tty->hw_stopped has never been set.
1299 if (uport->flags & UPF_HARD_FLOW)
1302 /* Handle turning off CRTSCTS */
1303 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1304 spin_lock_irqsave(&uport->lock, flags);
1305 tty->hw_stopped = 0;
1307 spin_unlock_irqrestore(&uport->lock, flags);
1309 /* Handle turning on CRTSCTS */
1310 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1311 spin_lock_irqsave(&uport->lock, flags);
1312 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1313 tty->hw_stopped = 1;
1314 uport->ops->stop_tx(uport);
1316 spin_unlock_irqrestore(&uport->lock, flags);
1321 * Calls to uart_close() are serialised via the tty_lock in
1322 * drivers/tty/tty_io.c:tty_release()
1323 * drivers/tty/tty_io.c:do_tty_hangup()
1324 * This runs from a workqueue and can sleep for a _short_ time only.
1326 static void uart_close(struct tty_struct *tty, struct file *filp)
1328 struct uart_state *state = tty->driver_data;
1329 struct tty_port *port;
1330 struct uart_port *uport;
1331 unsigned long flags;
1336 uport = state->uart_port;
1337 port = &state->port;
1339 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1341 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1345 * At this point, we stop accepting input. To do this, we
1346 * disable the receive line status interrupts.
1348 if (port->flags & ASYNC_INITIALIZED) {
1349 unsigned long flags;
1350 spin_lock_irqsave(&uport->lock, flags);
1351 uport->ops->stop_rx(uport);
1352 spin_unlock_irqrestore(&uport->lock, flags);
1354 * Before we drop DTR, make sure the UART transmitter
1355 * has completely drained; this is especially
1356 * important if there is a transmit FIFO!
1358 uart_wait_until_sent(tty, uport->timeout);
1361 mutex_lock(&port->mutex);
1362 uart_shutdown(tty, state);
1363 uart_flush_buffer(tty);
1365 tty_ldisc_flush(tty);
1367 tty_port_tty_set(port, NULL);
1369 spin_lock_irqsave(&port->lock, flags);
1371 if (port->blocked_open) {
1372 spin_unlock_irqrestore(&port->lock, flags);
1373 if (port->close_delay)
1374 msleep_interruptible(
1375 jiffies_to_msecs(port->close_delay));
1376 spin_lock_irqsave(&port->lock, flags);
1377 } else if (!uart_console(uport)) {
1378 spin_unlock_irqrestore(&port->lock, flags);
1379 uart_change_pm(state, UART_PM_STATE_OFF);
1380 spin_lock_irqsave(&port->lock, flags);
1384 * Wake up anyone trying to open this port.
1386 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1387 clear_bit(ASYNCB_CLOSING, &port->flags);
1388 spin_unlock_irqrestore(&port->lock, flags);
1389 wake_up_interruptible(&port->open_wait);
1390 wake_up_interruptible(&port->close_wait);
1392 mutex_unlock(&port->mutex);
1395 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1397 struct uart_state *state = tty->driver_data;
1398 struct uart_port *port = state->uart_port;
1399 unsigned long char_time, expire;
1401 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1405 * Set the check interval to be 1/5 of the estimated time to
1406 * send a single character, and make it at least 1. The check
1407 * interval should also be less than the timeout.
1409 * Note: we have to use pretty tight timings here to satisfy
1412 char_time = (port->timeout - HZ/50) / port->fifosize;
1413 char_time = char_time / 5;
1416 if (timeout && timeout < char_time)
1417 char_time = timeout;
1420 * If the transmitter hasn't cleared in twice the approximate
1421 * amount of time to send the entire FIFO, it probably won't
1422 * ever clear. This assumes the UART isn't doing flow
1423 * control, which is currently the case. Hence, if it ever
1424 * takes longer than port->timeout, this is probably due to a
1425 * UART bug of some kind. So, we clamp the timeout parameter at
1428 if (timeout == 0 || timeout > 2 * port->timeout)
1429 timeout = 2 * port->timeout;
1431 expire = jiffies + timeout;
1433 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1434 port->line, jiffies, expire);
1437 * Check whether the transmitter is empty every 'char_time'.
1438 * 'timeout' / 'expire' give us the maximum amount of time
1441 while (!port->ops->tx_empty(port)) {
1442 msleep_interruptible(jiffies_to_msecs(char_time));
1443 if (signal_pending(current))
1445 if (time_after(jiffies, expire))
1451 * Calls to uart_hangup() are serialised by the tty_lock in
1452 * drivers/tty/tty_io.c:do_tty_hangup()
1453 * This runs from a workqueue and can sleep for a _short_ time only.
1455 static void uart_hangup(struct tty_struct *tty)
1457 struct uart_state *state = tty->driver_data;
1458 struct tty_port *port = &state->port;
1459 unsigned long flags;
1461 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1463 mutex_lock(&port->mutex);
1464 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1465 uart_flush_buffer(tty);
1466 uart_shutdown(tty, state);
1467 spin_lock_irqsave(&port->lock, flags);
1469 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1470 spin_unlock_irqrestore(&port->lock, flags);
1471 tty_port_tty_set(port, NULL);
1472 if (!uart_console(state->uart_port))
1473 uart_change_pm(state, UART_PM_STATE_OFF);
1474 wake_up_interruptible(&port->open_wait);
1475 wake_up_interruptible(&port->delta_msr_wait);
1477 mutex_unlock(&port->mutex);
1480 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1485 static void uart_port_shutdown(struct tty_port *port)
1487 struct uart_state *state = container_of(port, struct uart_state, port);
1488 struct uart_port *uport = state->uart_port;
1491 * clear delta_msr_wait queue to avoid mem leaks: we may free
1492 * the irq here so the queue might never be woken up. Note
1493 * that we won't end up waiting on delta_msr_wait again since
1494 * any outstanding file descriptors should be pointing at
1495 * hung_up_tty_fops now.
1497 wake_up_interruptible(&port->delta_msr_wait);
1500 * Free the IRQ and disable the port.
1502 uport->ops->shutdown(uport);
1505 * Ensure that the IRQ handler isn't running on another CPU.
1507 synchronize_irq(uport->irq);
1510 static int uart_carrier_raised(struct tty_port *port)
1512 struct uart_state *state = container_of(port, struct uart_state, port);
1513 struct uart_port *uport = state->uart_port;
1515 spin_lock_irq(&uport->lock);
1516 uart_enable_ms(uport);
1517 mctrl = uport->ops->get_mctrl(uport);
1518 spin_unlock_irq(&uport->lock);
1519 if (mctrl & TIOCM_CAR)
1524 static void uart_dtr_rts(struct tty_port *port, int onoff)
1526 struct uart_state *state = container_of(port, struct uart_state, port);
1527 struct uart_port *uport = state->uart_port;
1530 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1532 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1536 * Calls to uart_open are serialised by the tty_lock in
1537 * drivers/tty/tty_io.c:tty_open()
1538 * Note that if this fails, then uart_close() _will_ be called.
1540 * In time, we want to scrap the "opening nonpresent ports"
1541 * behaviour and implement an alternative way for setserial
1542 * to set base addresses/ports/types. This will allow us to
1543 * get rid of a certain amount of extra tests.
1545 static int uart_open(struct tty_struct *tty, struct file *filp)
1547 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1548 int retval, line = tty->index;
1549 struct uart_state *state = drv->state + line;
1550 struct tty_port *port = &state->port;
1552 pr_debug("uart_open(%d) called\n", line);
1555 * We take the semaphore here to guarantee that we won't be re-entered
1556 * while allocating the state structure, or while we request any IRQs
1557 * that the driver may need. This also has the nice side-effect that
1558 * it delays the action of uart_hangup, so we can guarantee that
1559 * state->port.tty will always contain something reasonable.
1561 if (mutex_lock_interruptible(&port->mutex)) {
1562 retval = -ERESTARTSYS;
1567 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1573 * Once we set tty->driver_data here, we are guaranteed that
1574 * uart_close() will decrement the driver module use count.
1575 * Any failures from here onwards should not touch the count.
1577 tty->driver_data = state;
1578 state->uart_port->state = state;
1579 state->port.low_latency =
1580 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1581 tty_port_tty_set(port, tty);
1584 * Start up the serial port.
1586 retval = uart_startup(tty, state, 0);
1589 * If we succeeded, wait until the port is ready.
1591 mutex_unlock(&port->mutex);
1593 retval = tty_port_block_til_ready(port, tty, filp);
1599 mutex_unlock(&port->mutex);
1603 static const char *uart_type(struct uart_port *port)
1605 const char *str = NULL;
1607 if (port->ops->type)
1608 str = port->ops->type(port);
1616 #ifdef CONFIG_PROC_FS
1618 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1620 struct uart_state *state = drv->state + i;
1621 struct tty_port *port = &state->port;
1622 enum uart_pm_state pm_state;
1623 struct uart_port *uport = state->uart_port;
1625 unsigned int status;
1631 mmio = uport->iotype >= UPIO_MEM;
1632 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1633 uport->line, uart_type(uport),
1634 mmio ? "mmio:0x" : "port:",
1635 mmio ? (unsigned long long)uport->mapbase
1636 : (unsigned long long)uport->iobase,
1639 if (uport->type == PORT_UNKNOWN) {
1644 if (capable(CAP_SYS_ADMIN)) {
1645 mutex_lock(&port->mutex);
1646 pm_state = state->pm_state;
1647 if (pm_state != UART_PM_STATE_ON)
1648 uart_change_pm(state, UART_PM_STATE_ON);
1649 spin_lock_irq(&uport->lock);
1650 status = uport->ops->get_mctrl(uport);
1651 spin_unlock_irq(&uport->lock);
1652 if (pm_state != UART_PM_STATE_ON)
1653 uart_change_pm(state, pm_state);
1654 mutex_unlock(&port->mutex);
1656 seq_printf(m, " tx:%d rx:%d",
1657 uport->icount.tx, uport->icount.rx);
1658 if (uport->icount.frame)
1659 seq_printf(m, " fe:%d",
1660 uport->icount.frame);
1661 if (uport->icount.parity)
1662 seq_printf(m, " pe:%d",
1663 uport->icount.parity);
1664 if (uport->icount.brk)
1665 seq_printf(m, " brk:%d",
1667 if (uport->icount.overrun)
1668 seq_printf(m, " oe:%d",
1669 uport->icount.overrun);
1671 #define INFOBIT(bit, str) \
1672 if (uport->mctrl & (bit)) \
1673 strncat(stat_buf, (str), sizeof(stat_buf) - \
1674 strlen(stat_buf) - 2)
1675 #define STATBIT(bit, str) \
1676 if (status & (bit)) \
1677 strncat(stat_buf, (str), sizeof(stat_buf) - \
1678 strlen(stat_buf) - 2)
1682 INFOBIT(TIOCM_RTS, "|RTS");
1683 STATBIT(TIOCM_CTS, "|CTS");
1684 INFOBIT(TIOCM_DTR, "|DTR");
1685 STATBIT(TIOCM_DSR, "|DSR");
1686 STATBIT(TIOCM_CAR, "|CD");
1687 STATBIT(TIOCM_RNG, "|RI");
1691 seq_puts(m, stat_buf);
1698 static int uart_proc_show(struct seq_file *m, void *v)
1700 struct tty_driver *ttydrv = m->private;
1701 struct uart_driver *drv = ttydrv->driver_state;
1704 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1706 for (i = 0; i < drv->nr; i++)
1707 uart_line_info(m, drv, i);
1711 static int uart_proc_open(struct inode *inode, struct file *file)
1713 return single_open(file, uart_proc_show, PDE_DATA(inode));
1716 static const struct file_operations uart_proc_fops = {
1717 .owner = THIS_MODULE,
1718 .open = uart_proc_open,
1720 .llseek = seq_lseek,
1721 .release = single_release,
1725 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1727 * uart_console_write - write a console message to a serial port
1728 * @port: the port to write the message
1729 * @s: array of characters
1730 * @count: number of characters in string to write
1731 * @write: function to write character to port
1733 void uart_console_write(struct uart_port *port, const char *s,
1735 void (*putchar)(struct uart_port *, int))
1739 for (i = 0; i < count; i++, s++) {
1741 putchar(port, '\r');
1745 EXPORT_SYMBOL_GPL(uart_console_write);
1748 * Check whether an invalid uart number has been specified, and
1749 * if so, search for the first available port that does have
1752 struct uart_port * __init
1753 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1755 int idx = co->index;
1757 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1758 ports[idx].membase == NULL))
1759 for (idx = 0; idx < nr; idx++)
1760 if (ports[idx].iobase != 0 ||
1761 ports[idx].membase != NULL)
1770 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1771 * @options: pointer to option string
1772 * @baud: pointer to an 'int' variable for the baud rate.
1773 * @parity: pointer to an 'int' variable for the parity.
1774 * @bits: pointer to an 'int' variable for the number of data bits.
1775 * @flow: pointer to an 'int' variable for the flow control character.
1777 * uart_parse_options decodes a string containing the serial console
1778 * options. The format of the string is <baud><parity><bits><flow>,
1782 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1786 *baud = simple_strtoul(s, NULL, 10);
1787 while (*s >= '0' && *s <= '9')
1796 EXPORT_SYMBOL_GPL(uart_parse_options);
1803 static const struct baud_rates baud_rates[] = {
1804 { 921600, B921600 },
1805 { 460800, B460800 },
1806 { 230400, B230400 },
1807 { 115200, B115200 },
1819 * uart_set_options - setup the serial console parameters
1820 * @port: pointer to the serial ports uart_port structure
1821 * @co: console pointer
1823 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1824 * @bits: number of data bits
1825 * @flow: flow control character - 'r' (rts)
1828 uart_set_options(struct uart_port *port, struct console *co,
1829 int baud, int parity, int bits, int flow)
1831 struct ktermios termios;
1832 static struct ktermios dummy;
1836 * Ensure that the serial console lock is initialised
1838 * If this port is a console, then the spinlock is already
1841 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1842 spin_lock_init(&port->lock);
1843 lockdep_set_class(&port->lock, &port_lock_key);
1846 memset(&termios, 0, sizeof(struct ktermios));
1848 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1851 * Construct a cflag setting.
1853 for (i = 0; baud_rates[i].rate; i++)
1854 if (baud_rates[i].rate <= baud)
1857 termios.c_cflag |= baud_rates[i].cflag;
1860 termios.c_cflag |= CS7;
1862 termios.c_cflag |= CS8;
1866 termios.c_cflag |= PARODD;
1869 termios.c_cflag |= PARENB;
1874 termios.c_cflag |= CRTSCTS;
1877 * some uarts on other side don't support no flow control.
1878 * So we set * DTR in host uart to make them happy
1880 port->mctrl |= TIOCM_DTR;
1882 port->ops->set_termios(port, &termios, &dummy);
1884 * Allow the setting of the UART parameters with a NULL console
1888 co->cflag = termios.c_cflag;
1892 EXPORT_SYMBOL_GPL(uart_set_options);
1893 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1896 * uart_change_pm - set power state of the port
1898 * @state: port descriptor
1899 * @pm_state: new state
1901 * Locking: port->mutex has to be held
1903 static void uart_change_pm(struct uart_state *state,
1904 enum uart_pm_state pm_state)
1906 struct uart_port *port = state->uart_port;
1908 if (state->pm_state != pm_state) {
1910 port->ops->pm(port, pm_state, state->pm_state);
1911 state->pm_state = pm_state;
1916 struct uart_port *port;
1917 struct uart_driver *driver;
1920 static int serial_match_port(struct device *dev, void *data)
1922 struct uart_match *match = data;
1923 struct tty_driver *tty_drv = match->driver->tty_driver;
1924 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1927 return dev->devt == devt; /* Actually, only one tty per port */
1930 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1932 struct uart_state *state = drv->state + uport->line;
1933 struct tty_port *port = &state->port;
1934 struct device *tty_dev;
1935 struct uart_match match = {uport, drv};
1937 mutex_lock(&port->mutex);
1939 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1940 if (device_may_wakeup(tty_dev)) {
1941 if (!enable_irq_wake(uport->irq))
1942 uport->irq_wake = 1;
1943 put_device(tty_dev);
1944 mutex_unlock(&port->mutex);
1947 put_device(tty_dev);
1949 if (console_suspend_enabled || !uart_console(uport))
1950 uport->suspended = 1;
1952 if (port->flags & ASYNC_INITIALIZED) {
1953 const struct uart_ops *ops = uport->ops;
1956 if (console_suspend_enabled || !uart_console(uport)) {
1957 set_bit(ASYNCB_SUSPENDED, &port->flags);
1958 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1960 spin_lock_irq(&uport->lock);
1961 ops->stop_tx(uport);
1962 ops->set_mctrl(uport, 0);
1963 ops->stop_rx(uport);
1964 spin_unlock_irq(&uport->lock);
1968 * Wait for the transmitter to empty.
1970 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1973 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
1975 drv->tty_driver->name_base + uport->line);
1977 if (console_suspend_enabled || !uart_console(uport))
1978 ops->shutdown(uport);
1982 * Disable the console device before suspending.
1984 if (console_suspend_enabled && uart_console(uport))
1985 console_stop(uport->cons);
1987 if (console_suspend_enabled || !uart_console(uport))
1988 uart_change_pm(state, UART_PM_STATE_OFF);
1990 mutex_unlock(&port->mutex);
1995 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1997 struct uart_state *state = drv->state + uport->line;
1998 struct tty_port *port = &state->port;
1999 struct device *tty_dev;
2000 struct uart_match match = {uport, drv};
2001 struct ktermios termios;
2003 mutex_lock(&port->mutex);
2005 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2006 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2007 if (uport->irq_wake) {
2008 disable_irq_wake(uport->irq);
2009 uport->irq_wake = 0;
2011 put_device(tty_dev);
2012 mutex_unlock(&port->mutex);
2015 put_device(tty_dev);
2016 uport->suspended = 0;
2019 * Re-enable the console device after suspending.
2021 if (uart_console(uport)) {
2023 * First try to use the console cflag setting.
2025 memset(&termios, 0, sizeof(struct ktermios));
2026 termios.c_cflag = uport->cons->cflag;
2029 * If that's unset, use the tty termios setting.
2031 if (port->tty && termios.c_cflag == 0)
2032 termios = port->tty->termios;
2034 if (console_suspend_enabled)
2035 uart_change_pm(state, UART_PM_STATE_ON);
2036 uport->ops->set_termios(uport, &termios, NULL);
2037 if (console_suspend_enabled)
2038 console_start(uport->cons);
2041 if (port->flags & ASYNC_SUSPENDED) {
2042 const struct uart_ops *ops = uport->ops;
2045 uart_change_pm(state, UART_PM_STATE_ON);
2046 spin_lock_irq(&uport->lock);
2047 ops->set_mctrl(uport, 0);
2048 spin_unlock_irq(&uport->lock);
2049 if (console_suspend_enabled || !uart_console(uport)) {
2050 /* Protected by port mutex for now */
2051 struct tty_struct *tty = port->tty;
2052 ret = ops->startup(uport);
2055 uart_change_speed(tty, state, NULL);
2056 spin_lock_irq(&uport->lock);
2057 ops->set_mctrl(uport, uport->mctrl);
2058 ops->start_tx(uport);
2059 spin_unlock_irq(&uport->lock);
2060 set_bit(ASYNCB_INITIALIZED, &port->flags);
2063 * Failed to resume - maybe hardware went away?
2064 * Clear the "initialized" flag so we won't try
2065 * to call the low level drivers shutdown method.
2067 uart_shutdown(tty, state);
2071 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2074 mutex_unlock(&port->mutex);
2080 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2084 switch (port->iotype) {
2086 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2089 snprintf(address, sizeof(address),
2090 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2096 snprintf(address, sizeof(address),
2097 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2100 strlcpy(address, "*unknown*", sizeof(address));
2104 dev_info(port->dev, "%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2106 drv->tty_driver->name_base + port->line,
2107 address, port->irq, port->uartclk / 16, uart_type(port));
2111 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2112 struct uart_port *port)
2117 * If there isn't a port here, don't do anything further.
2119 if (!port->iobase && !port->mapbase && !port->membase)
2123 * Now do the auto configuration stuff. Note that config_port
2124 * is expected to claim the resources and map the port for us.
2127 if (port->flags & UPF_AUTO_IRQ)
2128 flags |= UART_CONFIG_IRQ;
2129 if (port->flags & UPF_BOOT_AUTOCONF) {
2130 if (!(port->flags & UPF_FIXED_TYPE)) {
2131 port->type = PORT_UNKNOWN;
2132 flags |= UART_CONFIG_TYPE;
2134 port->ops->config_port(port, flags);
2137 if (port->type != PORT_UNKNOWN) {
2138 unsigned long flags;
2140 uart_report_port(drv, port);
2142 /* Power up port for set_mctrl() */
2143 uart_change_pm(state, UART_PM_STATE_ON);
2146 * Ensure that the modem control lines are de-activated.
2147 * keep the DTR setting that is set in uart_set_options()
2148 * We probably don't need a spinlock around this, but
2150 spin_lock_irqsave(&port->lock, flags);
2151 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2152 spin_unlock_irqrestore(&port->lock, flags);
2155 * If this driver supports console, and it hasn't been
2156 * successfully registered yet, try to re-register it.
2157 * It may be that the port was not available.
2159 if (port->cons && !(port->cons->flags & CON_ENABLED))
2160 register_console(port->cons);
2163 * Power down all ports by default, except the
2164 * console if we have one.
2166 if (!uart_console(port))
2167 uart_change_pm(state, UART_PM_STATE_OFF);
2171 #ifdef CONFIG_CONSOLE_POLL
2173 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2175 struct uart_driver *drv = driver->driver_state;
2176 struct uart_state *state = drv->state + line;
2177 struct uart_port *port;
2184 if (!state || !state->uart_port)
2187 port = state->uart_port;
2188 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2191 if (port->ops->poll_init) {
2192 struct tty_port *tport = &state->port;
2195 mutex_lock(&tport->mutex);
2197 * We don't set ASYNCB_INITIALIZED as we only initialized the
2198 * hw, e.g. state->xmit is still uninitialized.
2200 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2201 ret = port->ops->poll_init(port);
2202 mutex_unlock(&tport->mutex);
2208 uart_parse_options(options, &baud, &parity, &bits, &flow);
2209 return uart_set_options(port, NULL, baud, parity, bits, flow);
2215 static int uart_poll_get_char(struct tty_driver *driver, int line)
2217 struct uart_driver *drv = driver->driver_state;
2218 struct uart_state *state = drv->state + line;
2219 struct uart_port *port;
2221 if (!state || !state->uart_port)
2224 port = state->uart_port;
2225 return port->ops->poll_get_char(port);
2228 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2230 struct uart_driver *drv = driver->driver_state;
2231 struct uart_state *state = drv->state + line;
2232 struct uart_port *port;
2234 if (!state || !state->uart_port)
2237 port = state->uart_port;
2240 port->ops->poll_put_char(port, '\r');
2241 port->ops->poll_put_char(port, ch);
2245 static const struct tty_operations uart_ops = {
2247 .close = uart_close,
2248 .write = uart_write,
2249 .put_char = uart_put_char,
2250 .flush_chars = uart_flush_chars,
2251 .write_room = uart_write_room,
2252 .chars_in_buffer= uart_chars_in_buffer,
2253 .flush_buffer = uart_flush_buffer,
2254 .ioctl = uart_ioctl,
2255 .throttle = uart_throttle,
2256 .unthrottle = uart_unthrottle,
2257 .send_xchar = uart_send_xchar,
2258 .set_termios = uart_set_termios,
2259 .set_ldisc = uart_set_ldisc,
2261 .start = uart_start,
2262 .hangup = uart_hangup,
2263 .break_ctl = uart_break_ctl,
2264 .wait_until_sent= uart_wait_until_sent,
2265 #ifdef CONFIG_PROC_FS
2266 .proc_fops = &uart_proc_fops,
2268 .tiocmget = uart_tiocmget,
2269 .tiocmset = uart_tiocmset,
2270 .get_icount = uart_get_icount,
2271 #ifdef CONFIG_CONSOLE_POLL
2272 .poll_init = uart_poll_init,
2273 .poll_get_char = uart_poll_get_char,
2274 .poll_put_char = uart_poll_put_char,
2278 static const struct tty_port_operations uart_port_ops = {
2279 .activate = uart_port_activate,
2280 .shutdown = uart_port_shutdown,
2281 .carrier_raised = uart_carrier_raised,
2282 .dtr_rts = uart_dtr_rts,
2286 * uart_register_driver - register a driver with the uart core layer
2287 * @drv: low level driver structure
2289 * Register a uart driver with the core driver. We in turn register
2290 * with the tty layer, and initialise the core driver per-port state.
2292 * We have a proc file in /proc/tty/driver which is named after the
2295 * drv->port should be NULL, and the per-port structures should be
2296 * registered using uart_add_one_port after this call has succeeded.
2298 int uart_register_driver(struct uart_driver *drv)
2300 struct tty_driver *normal;
2306 * Maybe we should be using a slab cache for this, especially if
2307 * we have a large number of ports to handle.
2309 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2313 normal = alloc_tty_driver(drv->nr);
2317 drv->tty_driver = normal;
2319 normal->driver_name = drv->driver_name;
2320 normal->name = drv->dev_name;
2321 normal->major = drv->major;
2322 normal->minor_start = drv->minor;
2323 normal->type = TTY_DRIVER_TYPE_SERIAL;
2324 normal->subtype = SERIAL_TYPE_NORMAL;
2325 normal->init_termios = tty_std_termios;
2326 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2327 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2328 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2329 normal->driver_state = drv;
2330 tty_set_operations(normal, &uart_ops);
2333 * Initialise the UART state(s).
2335 for (i = 0; i < drv->nr; i++) {
2336 struct uart_state *state = drv->state + i;
2337 struct tty_port *port = &state->port;
2339 tty_port_init(port);
2340 port->ops = &uart_port_ops;
2341 port->close_delay = HZ / 2; /* .5 seconds */
2342 port->closing_wait = 30 * HZ;/* 30 seconds */
2345 retval = tty_register_driver(normal);
2349 for (i = 0; i < drv->nr; i++)
2350 tty_port_destroy(&drv->state[i].port);
2351 put_tty_driver(normal);
2359 * uart_unregister_driver - remove a driver from the uart core layer
2360 * @drv: low level driver structure
2362 * Remove all references to a driver from the core driver. The low
2363 * level driver must have removed all its ports via the
2364 * uart_remove_one_port() if it registered them with uart_add_one_port().
2365 * (ie, drv->port == NULL)
2367 void uart_unregister_driver(struct uart_driver *drv)
2369 struct tty_driver *p = drv->tty_driver;
2372 tty_unregister_driver(p);
2374 for (i = 0; i < drv->nr; i++)
2375 tty_port_destroy(&drv->state[i].port);
2378 drv->tty_driver = NULL;
2381 struct tty_driver *uart_console_device(struct console *co, int *index)
2383 struct uart_driver *p = co->data;
2385 return p->tty_driver;
2388 static ssize_t uart_get_attr_uartclk(struct device *dev,
2389 struct device_attribute *attr, char *buf)
2391 struct serial_struct tmp;
2392 struct tty_port *port = dev_get_drvdata(dev);
2394 uart_get_info(port, &tmp);
2395 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2398 static ssize_t uart_get_attr_type(struct device *dev,
2399 struct device_attribute *attr, char *buf)
2401 struct serial_struct tmp;
2402 struct tty_port *port = dev_get_drvdata(dev);
2404 uart_get_info(port, &tmp);
2405 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2407 static ssize_t uart_get_attr_line(struct device *dev,
2408 struct device_attribute *attr, char *buf)
2410 struct serial_struct tmp;
2411 struct tty_port *port = dev_get_drvdata(dev);
2413 uart_get_info(port, &tmp);
2414 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2417 static ssize_t uart_get_attr_port(struct device *dev,
2418 struct device_attribute *attr, char *buf)
2420 struct serial_struct tmp;
2421 struct tty_port *port = dev_get_drvdata(dev);
2422 unsigned long ioaddr;
2424 uart_get_info(port, &tmp);
2426 if (HIGH_BITS_OFFSET)
2427 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2428 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2431 static ssize_t uart_get_attr_irq(struct device *dev,
2432 struct device_attribute *attr, char *buf)
2434 struct serial_struct tmp;
2435 struct tty_port *port = dev_get_drvdata(dev);
2437 uart_get_info(port, &tmp);
2438 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2441 static ssize_t uart_get_attr_flags(struct device *dev,
2442 struct device_attribute *attr, char *buf)
2444 struct serial_struct tmp;
2445 struct tty_port *port = dev_get_drvdata(dev);
2447 uart_get_info(port, &tmp);
2448 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2451 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2452 struct device_attribute *attr, char *buf)
2454 struct serial_struct tmp;
2455 struct tty_port *port = dev_get_drvdata(dev);
2457 uart_get_info(port, &tmp);
2458 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2462 static ssize_t uart_get_attr_close_delay(struct device *dev,
2463 struct device_attribute *attr, char *buf)
2465 struct serial_struct tmp;
2466 struct tty_port *port = dev_get_drvdata(dev);
2468 uart_get_info(port, &tmp);
2469 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2473 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2474 struct device_attribute *attr, char *buf)
2476 struct serial_struct tmp;
2477 struct tty_port *port = dev_get_drvdata(dev);
2479 uart_get_info(port, &tmp);
2480 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2483 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2484 struct device_attribute *attr, char *buf)
2486 struct serial_struct tmp;
2487 struct tty_port *port = dev_get_drvdata(dev);
2489 uart_get_info(port, &tmp);
2490 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2493 static ssize_t uart_get_attr_io_type(struct device *dev,
2494 struct device_attribute *attr, char *buf)
2496 struct serial_struct tmp;
2497 struct tty_port *port = dev_get_drvdata(dev);
2499 uart_get_info(port, &tmp);
2500 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2503 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2504 struct device_attribute *attr, char *buf)
2506 struct serial_struct tmp;
2507 struct tty_port *port = dev_get_drvdata(dev);
2509 uart_get_info(port, &tmp);
2510 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2513 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2514 struct device_attribute *attr, char *buf)
2516 struct serial_struct tmp;
2517 struct tty_port *port = dev_get_drvdata(dev);
2519 uart_get_info(port, &tmp);
2520 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2523 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2524 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2525 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2526 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2527 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2528 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2529 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2530 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2531 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2532 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2533 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2534 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2535 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2537 static struct attribute *tty_dev_attrs[] = {
2538 &dev_attr_type.attr,
2539 &dev_attr_line.attr,
2540 &dev_attr_port.attr,
2542 &dev_attr_flags.attr,
2543 &dev_attr_xmit_fifo_size.attr,
2544 &dev_attr_uartclk.attr,
2545 &dev_attr_close_delay.attr,
2546 &dev_attr_closing_wait.attr,
2547 &dev_attr_custom_divisor.attr,
2548 &dev_attr_io_type.attr,
2549 &dev_attr_iomem_base.attr,
2550 &dev_attr_iomem_reg_shift.attr,
2554 static const struct attribute_group tty_dev_attr_group = {
2555 .attrs = tty_dev_attrs,
2559 * uart_add_one_port - attach a driver-defined port structure
2560 * @drv: pointer to the uart low level driver structure for this port
2561 * @uport: uart port structure to use for this port.
2563 * This allows the driver to register its own uart_port structure
2564 * with the core driver. The main purpose is to allow the low
2565 * level uart drivers to expand uart_port, rather than having yet
2566 * more levels of structures.
2568 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2570 struct uart_state *state;
2571 struct tty_port *port;
2573 struct device *tty_dev;
2576 BUG_ON(in_interrupt());
2578 if (uport->line >= drv->nr)
2581 state = drv->state + uport->line;
2582 port = &state->port;
2584 mutex_lock(&port_mutex);
2585 mutex_lock(&port->mutex);
2586 if (state->uart_port) {
2591 state->uart_port = uport;
2592 state->pm_state = UART_PM_STATE_UNDEFINED;
2594 uport->cons = drv->cons;
2595 uport->state = state;
2598 * If this port is a console, then the spinlock is already
2601 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2602 spin_lock_init(&uport->lock);
2603 lockdep_set_class(&uport->lock, &port_lock_key);
2605 if (uport->cons && uport->dev)
2606 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2608 uart_configure_port(drv, state, uport);
2611 if (uport->attr_group)
2614 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2616 if (!uport->tty_groups) {
2620 uport->tty_groups[0] = &tty_dev_attr_group;
2621 if (uport->attr_group)
2622 uport->tty_groups[1] = uport->attr_group;
2625 * Register the port whether it's detected or not. This allows
2626 * setserial to be used to alter this port's parameters.
2628 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2629 uport->line, uport->dev, port, uport->tty_groups);
2630 if (likely(!IS_ERR(tty_dev))) {
2631 device_set_wakeup_capable(tty_dev, 1);
2633 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2638 * Ensure UPF_DEAD is not set.
2640 uport->flags &= ~UPF_DEAD;
2643 mutex_unlock(&port->mutex);
2644 mutex_unlock(&port_mutex);
2650 * uart_remove_one_port - detach a driver defined port structure
2651 * @drv: pointer to the uart low level driver structure for this port
2652 * @uport: uart port structure for this port
2654 * This unhooks (and hangs up) the specified port structure from the
2655 * core driver. No further calls will be made to the low-level code
2658 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2660 struct uart_state *state = drv->state + uport->line;
2661 struct tty_port *port = &state->port;
2662 struct tty_struct *tty;
2665 BUG_ON(in_interrupt());
2667 if (state->uart_port != uport)
2668 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2669 state->uart_port, uport);
2671 mutex_lock(&port_mutex);
2674 * Mark the port "dead" - this prevents any opens from
2675 * succeeding while we shut down the port.
2677 mutex_lock(&port->mutex);
2678 if (!state->uart_port) {
2679 mutex_unlock(&port->mutex);
2683 uport->flags |= UPF_DEAD;
2684 mutex_unlock(&port->mutex);
2687 * Remove the devices from the tty layer
2689 tty_unregister_device(drv->tty_driver, uport->line);
2691 tty = tty_port_tty_get(port);
2693 tty_vhangup(port->tty);
2698 * If the port is used as a console, unregister it
2700 if (uart_console(uport))
2701 unregister_console(uport->cons);
2704 * Free the port IO and memory resources, if any.
2706 if (uport->type != PORT_UNKNOWN)
2707 uport->ops->release_port(uport);
2708 kfree(uport->tty_groups);
2711 * Indicate that there isn't a port here anymore.
2713 uport->type = PORT_UNKNOWN;
2715 state->uart_port = NULL;
2717 mutex_unlock(&port_mutex);
2723 * Are the two ports equivalent?
2725 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2727 if (port1->iotype != port2->iotype)
2730 switch (port1->iotype) {
2732 return (port1->iobase == port2->iobase);
2734 return (port1->iobase == port2->iobase) &&
2735 (port1->hub6 == port2->hub6);
2740 return (port1->mapbase == port2->mapbase);
2744 EXPORT_SYMBOL(uart_match_port);
2747 * uart_handle_dcd_change - handle a change of carrier detect state
2748 * @uport: uart_port structure for the open port
2749 * @status: new carrier detect status, nonzero if active
2751 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2753 struct tty_port *port = &uport->state->port;
2754 struct tty_struct *tty = port->tty;
2755 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2758 if (ld->ops->dcd_change)
2759 ld->ops->dcd_change(tty, status);
2760 tty_ldisc_deref(ld);
2763 uport->icount.dcd++;
2765 if (port->flags & ASYNC_CHECK_CD) {
2767 wake_up_interruptible(&port->open_wait);
2772 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2775 * uart_handle_cts_change - handle a change of clear-to-send state
2776 * @uport: uart_port structure for the open port
2777 * @status: new clear to send status, nonzero if active
2779 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2781 struct tty_port *port = &uport->state->port;
2782 struct tty_struct *tty = port->tty;
2784 uport->icount.cts++;
2786 if (tty_port_cts_enabled(port)) {
2787 if (tty->hw_stopped) {
2789 tty->hw_stopped = 0;
2790 uport->ops->start_tx(uport);
2791 uart_write_wakeup(uport);
2795 tty->hw_stopped = 1;
2796 uport->ops->stop_tx(uport);
2801 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2804 * uart_insert_char - push a char to the uart layer
2806 * User is responsible to call tty_flip_buffer_push when they are done with
2809 * @port: corresponding port
2810 * @status: state of the serial port RX buffer (LSR for 8250)
2811 * @overrun: mask of overrun bits in @status
2812 * @ch: character to push
2813 * @flag: flag for the character (see TTY_NORMAL and friends)
2815 void uart_insert_char(struct uart_port *port, unsigned int status,
2816 unsigned int overrun, unsigned int ch, unsigned int flag)
2818 struct tty_port *tport = &port->state->port;
2820 if ((status & port->ignore_status_mask & ~overrun) == 0)
2821 if (tty_insert_flip_char(tport, ch, flag) == 0)
2822 ++port->icount.buf_overrun;
2825 * Overrun is special. Since it's reported immediately,
2826 * it doesn't affect the current character.
2828 if (status & ~port->ignore_status_mask & overrun)
2829 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2830 ++port->icount.buf_overrun;
2832 EXPORT_SYMBOL_GPL(uart_insert_char);
2834 EXPORT_SYMBOL(uart_write_wakeup);
2835 EXPORT_SYMBOL(uart_register_driver);
2836 EXPORT_SYMBOL(uart_unregister_driver);
2837 EXPORT_SYMBOL(uart_suspend_port);
2838 EXPORT_SYMBOL(uart_resume_port);
2839 EXPORT_SYMBOL(uart_add_one_port);
2840 EXPORT_SYMBOL(uart_remove_one_port);
2842 MODULE_DESCRIPTION("Serial driver core");
2843 MODULE_LICENSE("GPL");