2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/proc_fs.h>
30 #include <linux/seq_file.h>
31 #include <linux/device.h>
32 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33 #include <linux/serial_core.h>
34 #include <linux/delay.h>
35 #include <linux/mutex.h>
38 #include <asm/uaccess.h>
41 * This is used to lock changes in serial line configuration.
43 static DEFINE_MUTEX(port_mutex);
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
49 static struct lock_class_key port_lock_key;
51 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53 #ifdef CONFIG_SERIAL_CORE_CONSOLE
54 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
56 #define uart_console(port) (0)
59 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
60 struct ktermios *old_termios);
61 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
62 static void uart_change_pm(struct uart_state *state,
63 enum uart_pm_state pm_state);
65 static void uart_port_shutdown(struct tty_port *port);
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
71 void uart_write_wakeup(struct uart_port *port)
73 struct uart_state *state = port->state;
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
79 tty_wakeup(state->port.tty);
82 static void uart_stop(struct tty_struct *tty)
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
93 static void __uart_start(struct tty_struct *tty)
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
98 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
99 !tty->stopped && !tty->hw_stopped)
100 port->ops->start_tx(port);
103 static void uart_start(struct tty_struct *tty)
105 struct uart_state *state = tty->driver_data;
106 struct uart_port *port = state->uart_port;
109 spin_lock_irqsave(&port->lock, flags);
111 spin_unlock_irqrestore(&port->lock, flags);
115 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
120 spin_lock_irqsave(&port->lock, flags);
122 port->mctrl = (old & ~clear) | set;
123 if (old != port->mctrl)
124 port->ops->set_mctrl(port, port->mctrl);
125 spin_unlock_irqrestore(&port->lock, flags);
128 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
129 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
132 * Startup the port. This will be called once per open. All calls
133 * will be serialised by the per-port mutex.
135 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
138 struct uart_port *uport = state->uart_port;
139 struct tty_port *port = &state->port;
143 if (uport->type == PORT_UNKNOWN)
147 * Initialise and allocate the transmit and temporary
150 if (!state->xmit.buf) {
151 /* This is protected by the per port mutex */
152 page = get_zeroed_page(GFP_KERNEL);
156 state->xmit.buf = (unsigned char *) page;
157 uart_circ_clear(&state->xmit);
160 retval = uport->ops->startup(uport);
162 if (uart_console(uport) && uport->cons->cflag) {
163 tty->termios.c_cflag = uport->cons->cflag;
164 uport->cons->cflag = 0;
167 * Initialise the hardware port settings.
169 uart_change_speed(tty, state, NULL);
173 * Setup the RTS and DTR signals once the
174 * port is open and ready to respond.
176 if (tty->termios.c_cflag & CBAUD)
177 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
180 if (tty_port_cts_enabled(port)) {
181 spin_lock_irq(&uport->lock);
182 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
184 spin_unlock_irq(&uport->lock);
189 * This is to allow setserial on this port. People may want to set
190 * port/irq/type and then reconfigure the port properly if it failed
193 if (retval && capable(CAP_SYS_ADMIN))
199 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
202 struct tty_port *port = &state->port;
205 if (port->flags & ASYNC_INITIALIZED)
209 * Set the TTY IO error marker - we will only clear this
210 * once we have successfully opened the port.
212 set_bit(TTY_IO_ERROR, &tty->flags);
214 retval = uart_port_startup(tty, state, init_hw);
216 set_bit(ASYNCB_INITIALIZED, &port->flags);
217 clear_bit(TTY_IO_ERROR, &tty->flags);
218 } else if (retval > 0)
225 * This routine will shutdown a serial port; interrupts are disabled, and
226 * DTR is dropped if the hangup on close termio flag is on. Calls to
227 * uart_shutdown are serialised by the per-port semaphore.
229 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
231 struct uart_port *uport = state->uart_port;
232 struct tty_port *port = &state->port;
235 * Set the TTY IO error marker
238 set_bit(TTY_IO_ERROR, &tty->flags);
240 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
242 * Turn off DTR and RTS early.
244 if (!tty || (tty->termios.c_cflag & HUPCL))
245 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
247 uart_port_shutdown(port);
251 * It's possible for shutdown to be called after suspend if we get
252 * a DCD drop (hangup) at just the right time. Clear suspended bit so
253 * we don't try to resume a port that has been shutdown.
255 clear_bit(ASYNCB_SUSPENDED, &port->flags);
258 * Free the transmit buffer page.
260 if (state->xmit.buf) {
261 free_page((unsigned long)state->xmit.buf);
262 state->xmit.buf = NULL;
267 * uart_update_timeout - update per-port FIFO timeout.
268 * @port: uart_port structure describing the port
269 * @cflag: termios cflag value
270 * @baud: speed of the port
272 * Set the port FIFO timeout value. The @cflag value should
273 * reflect the actual hardware settings.
276 uart_update_timeout(struct uart_port *port, unsigned int cflag,
281 /* byte size and parity */
282 switch (cflag & CSIZE) {
303 * The total number of bits to be transmitted in the fifo.
305 bits = bits * port->fifosize;
308 * Figure the timeout to send the above number of bits.
309 * Add .02 seconds of slop
311 port->timeout = (HZ * bits) / baud + HZ/50;
314 EXPORT_SYMBOL(uart_update_timeout);
317 * uart_get_baud_rate - return baud rate for a particular port
318 * @port: uart_port structure describing the port in question.
319 * @termios: desired termios settings.
320 * @old: old termios (or NULL)
321 * @min: minimum acceptable baud rate
322 * @max: maximum acceptable baud rate
324 * Decode the termios structure into a numeric baud rate,
325 * taking account of the magic 38400 baud rate (with spd_*
326 * flags), and mapping the %B0 rate to 9600 baud.
328 * If the new baud rate is invalid, try the old termios setting.
329 * If it's still invalid, we try 9600 baud.
331 * Update the @termios structure to reflect the baud rate
332 * we're actually going to be using. Don't do this for the case
333 * where B0 is requested ("hang up").
336 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
337 struct ktermios *old, unsigned int min, unsigned int max)
339 unsigned int try, baud, altbaud = 38400;
341 upf_t flags = port->flags & UPF_SPD_MASK;
343 if (flags == UPF_SPD_HI)
345 else if (flags == UPF_SPD_VHI)
347 else if (flags == UPF_SPD_SHI)
349 else if (flags == UPF_SPD_WARP)
352 for (try = 0; try < 2; try++) {
353 baud = tty_termios_baud_rate(termios);
356 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
363 * Special case: B0 rate.
370 if (baud >= min && baud <= max)
374 * Oops, the quotient was zero. Try again with
375 * the old baud rate if possible.
377 termios->c_cflag &= ~CBAUD;
379 baud = tty_termios_baud_rate(old);
381 tty_termios_encode_baud_rate(termios,
388 * As a last resort, if the range cannot be met then clip to
389 * the nearest chip supported rate.
393 tty_termios_encode_baud_rate(termios,
396 tty_termios_encode_baud_rate(termios,
400 /* Should never happen */
405 EXPORT_SYMBOL(uart_get_baud_rate);
408 * uart_get_divisor - return uart clock divisor
409 * @port: uart_port structure describing the port.
410 * @baud: desired baud rate
412 * Calculate the uart clock divisor for the port.
415 uart_get_divisor(struct uart_port *port, unsigned int baud)
420 * Old custom speed handling.
422 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
423 quot = port->custom_divisor;
425 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
430 EXPORT_SYMBOL(uart_get_divisor);
432 /* FIXME: Consistent locking policy */
433 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
434 struct ktermios *old_termios)
436 struct tty_port *port = &state->port;
437 struct uart_port *uport = state->uart_port;
438 struct ktermios *termios;
441 * If we have no tty, termios, or the port does not exist,
442 * then we can't set the parameters for this port.
444 if (!tty || uport->type == PORT_UNKNOWN)
447 termios = &tty->termios;
450 * Set flags based on termios cflag
452 if (termios->c_cflag & CRTSCTS)
453 set_bit(ASYNCB_CTS_FLOW, &port->flags);
455 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
457 if (termios->c_cflag & CLOCAL)
458 clear_bit(ASYNCB_CHECK_CD, &port->flags);
460 set_bit(ASYNCB_CHECK_CD, &port->flags);
462 uport->ops->set_termios(uport, termios, old_termios);
465 static inline int __uart_put_char(struct uart_port *port,
466 struct circ_buf *circ, unsigned char c)
474 spin_lock_irqsave(&port->lock, flags);
475 if (uart_circ_chars_free(circ) != 0) {
476 circ->buf[circ->head] = c;
477 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
480 spin_unlock_irqrestore(&port->lock, flags);
484 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
486 struct uart_state *state = tty->driver_data;
488 return __uart_put_char(state->uart_port, &state->xmit, ch);
491 static void uart_flush_chars(struct tty_struct *tty)
496 static int uart_write(struct tty_struct *tty,
497 const unsigned char *buf, int count)
499 struct uart_state *state = tty->driver_data;
500 struct uart_port *port;
501 struct circ_buf *circ;
506 * This means you called this function _after_ the port was
507 * closed. No cookie for you.
514 port = state->uart_port;
520 spin_lock_irqsave(&port->lock, flags);
522 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
527 memcpy(circ->buf + circ->head, buf, c);
528 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
533 spin_unlock_irqrestore(&port->lock, flags);
539 static int uart_write_room(struct tty_struct *tty)
541 struct uart_state *state = tty->driver_data;
545 spin_lock_irqsave(&state->uart_port->lock, flags);
546 ret = uart_circ_chars_free(&state->xmit);
547 spin_unlock_irqrestore(&state->uart_port->lock, flags);
551 static int uart_chars_in_buffer(struct tty_struct *tty)
553 struct uart_state *state = tty->driver_data;
557 spin_lock_irqsave(&state->uart_port->lock, flags);
558 ret = uart_circ_chars_pending(&state->xmit);
559 spin_unlock_irqrestore(&state->uart_port->lock, flags);
563 static void uart_flush_buffer(struct tty_struct *tty)
565 struct uart_state *state = tty->driver_data;
566 struct uart_port *port;
570 * This means you called this function _after_ the port was
571 * closed. No cookie for you.
578 port = state->uart_port;
579 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
581 spin_lock_irqsave(&port->lock, flags);
582 uart_circ_clear(&state->xmit);
583 if (port->ops->flush_buffer)
584 port->ops->flush_buffer(port);
585 spin_unlock_irqrestore(&port->lock, flags);
590 * This function is used to send a high-priority XON/XOFF character to
593 static void uart_send_xchar(struct tty_struct *tty, char ch)
595 struct uart_state *state = tty->driver_data;
596 struct uart_port *port = state->uart_port;
599 if (port->ops->send_xchar)
600 port->ops->send_xchar(port, ch);
604 spin_lock_irqsave(&port->lock, flags);
605 port->ops->start_tx(port);
606 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.
835 if (retval && old_type != PORT_UNKNOWN) {
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;
842 retval = uport->ops->request_port(uport);
844 * If we failed to restore the old settings,
848 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 "%s sets custom speed on %s. This "
888 "is deprecated.\n", current->comm,
889 tty_name(port->tty, buf));
891 uart_change_speed(tty, state, NULL);
894 retval = uart_startup(tty, state, 1);
899 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
900 struct serial_struct __user *newinfo)
902 struct serial_struct new_serial;
903 struct tty_port *port = &state->port;
906 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
910 * This semaphore protects port->count. It is also
911 * very useful to prevent opens. Also, take the
912 * port configuration semaphore to make sure that a
913 * module insertion/removal doesn't change anything
916 mutex_lock(&port->mutex);
917 retval = uart_set_info(tty, port, state, &new_serial);
918 mutex_unlock(&port->mutex);
923 * uart_get_lsr_info - get line status register info
924 * @tty: tty associated with the UART
925 * @state: UART being queried
926 * @value: returned modem value
928 * Note: uart_ioctl protects us against hangups.
930 static int uart_get_lsr_info(struct tty_struct *tty,
931 struct uart_state *state, unsigned int __user *value)
933 struct uart_port *uport = state->uart_port;
936 result = uport->ops->tx_empty(uport);
939 * If we're about to load something into the transmit
940 * register, we'll pretend the transmitter isn't empty to
941 * avoid a race condition (depending on when the transmit
942 * interrupt happens).
945 ((uart_circ_chars_pending(&state->xmit) > 0) &&
946 !tty->stopped && !tty->hw_stopped))
947 result &= ~TIOCSER_TEMT;
949 return put_user(result, value);
952 static int uart_tiocmget(struct tty_struct *tty)
954 struct uart_state *state = tty->driver_data;
955 struct tty_port *port = &state->port;
956 struct uart_port *uport = state->uart_port;
959 mutex_lock(&port->mutex);
960 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
961 result = uport->mctrl;
962 spin_lock_irq(&uport->lock);
963 result |= uport->ops->get_mctrl(uport);
964 spin_unlock_irq(&uport->lock);
966 mutex_unlock(&port->mutex);
972 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
974 struct uart_state *state = tty->driver_data;
975 struct uart_port *uport = state->uart_port;
976 struct tty_port *port = &state->port;
979 mutex_lock(&port->mutex);
980 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
981 uart_update_mctrl(uport, set, clear);
984 mutex_unlock(&port->mutex);
988 static int uart_break_ctl(struct tty_struct *tty, int break_state)
990 struct uart_state *state = tty->driver_data;
991 struct tty_port *port = &state->port;
992 struct uart_port *uport = state->uart_port;
994 mutex_lock(&port->mutex);
996 if (uport->type != PORT_UNKNOWN)
997 uport->ops->break_ctl(uport, break_state);
999 mutex_unlock(&port->mutex);
1003 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1005 struct uart_port *uport = state->uart_port;
1006 struct tty_port *port = &state->port;
1009 if (!capable(CAP_SYS_ADMIN))
1013 * Take the per-port semaphore. This prevents count from
1014 * changing, and hence any extra opens of the port while
1015 * we're auto-configuring.
1017 if (mutex_lock_interruptible(&port->mutex))
1018 return -ERESTARTSYS;
1021 if (tty_port_users(port) == 1) {
1022 uart_shutdown(tty, state);
1025 * If we already have a port type configured,
1026 * we must release its resources.
1028 if (uport->type != PORT_UNKNOWN)
1029 uport->ops->release_port(uport);
1031 flags = UART_CONFIG_TYPE;
1032 if (uport->flags & UPF_AUTO_IRQ)
1033 flags |= UART_CONFIG_IRQ;
1036 * This will claim the ports resources if
1039 uport->ops->config_port(uport, flags);
1041 ret = uart_startup(tty, state, 1);
1043 mutex_unlock(&port->mutex);
1048 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1049 * - mask passed in arg for lines of interest
1050 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1051 * Caller should use TIOCGICOUNT to see which one it was
1053 * FIXME: This wants extracting into a common all driver implementation
1054 * of TIOCMWAIT using tty_port.
1057 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1059 struct uart_port *uport = state->uart_port;
1060 struct tty_port *port = &state->port;
1061 DECLARE_WAITQUEUE(wait, current);
1062 struct uart_icount cprev, cnow;
1066 * note the counters on entry
1068 spin_lock_irq(&uport->lock);
1069 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1072 * Force modem status interrupts on
1074 uport->ops->enable_ms(uport);
1075 spin_unlock_irq(&uport->lock);
1077 add_wait_queue(&port->delta_msr_wait, &wait);
1079 spin_lock_irq(&uport->lock);
1080 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1081 spin_unlock_irq(&uport->lock);
1083 set_current_state(TASK_INTERRUPTIBLE);
1085 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1086 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1087 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1088 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1095 /* see if a signal did it */
1096 if (signal_pending(current)) {
1104 current->state = TASK_RUNNING;
1105 remove_wait_queue(&port->delta_msr_wait, &wait);
1111 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1112 * Return: write counters to the user passed counter struct
1113 * NB: both 1->0 and 0->1 transitions are counted except for
1114 * RI where only 0->1 is counted.
1116 static int uart_get_icount(struct tty_struct *tty,
1117 struct serial_icounter_struct *icount)
1119 struct uart_state *state = tty->driver_data;
1120 struct uart_icount cnow;
1121 struct uart_port *uport = state->uart_port;
1123 spin_lock_irq(&uport->lock);
1124 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1125 spin_unlock_irq(&uport->lock);
1127 icount->cts = cnow.cts;
1128 icount->dsr = cnow.dsr;
1129 icount->rng = cnow.rng;
1130 icount->dcd = cnow.dcd;
1131 icount->rx = cnow.rx;
1132 icount->tx = cnow.tx;
1133 icount->frame = cnow.frame;
1134 icount->overrun = cnow.overrun;
1135 icount->parity = cnow.parity;
1136 icount->brk = cnow.brk;
1137 icount->buf_overrun = cnow.buf_overrun;
1143 * Called via sys_ioctl. We can use spin_lock_irq() here.
1146 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1149 struct uart_state *state = tty->driver_data;
1150 struct tty_port *port = &state->port;
1151 void __user *uarg = (void __user *)arg;
1152 int ret = -ENOIOCTLCMD;
1156 * These ioctls don't rely on the hardware to be present.
1160 ret = uart_get_info_user(port, uarg);
1164 ret = uart_set_info_user(tty, state, uarg);
1168 ret = uart_do_autoconfig(tty, state);
1171 case TIOCSERGWILD: /* obsolete */
1172 case TIOCSERSWILD: /* obsolete */
1177 if (ret != -ENOIOCTLCMD)
1180 if (tty->flags & (1 << TTY_IO_ERROR)) {
1186 * The following should only be used when hardware is present.
1190 ret = uart_wait_modem_status(state, arg);
1194 if (ret != -ENOIOCTLCMD)
1197 mutex_lock(&port->mutex);
1199 if (tty->flags & (1 << TTY_IO_ERROR)) {
1205 * All these rely on hardware being present and need to be
1206 * protected against the tty being hung up.
1209 case TIOCSERGETLSR: /* Get line status register */
1210 ret = uart_get_lsr_info(tty, state, uarg);
1214 struct uart_port *uport = state->uart_port;
1215 if (uport->ops->ioctl)
1216 ret = uport->ops->ioctl(uport, cmd, arg);
1221 mutex_unlock(&port->mutex);
1226 static void uart_set_ldisc(struct tty_struct *tty)
1228 struct uart_state *state = tty->driver_data;
1229 struct uart_port *uport = state->uart_port;
1231 if (uport->ops->set_ldisc)
1232 uport->ops->set_ldisc(uport, tty->termios.c_line);
1235 static void uart_set_termios(struct tty_struct *tty,
1236 struct ktermios *old_termios)
1238 struct uart_state *state = tty->driver_data;
1239 struct uart_port *uport = state->uart_port;
1240 unsigned long flags;
1241 unsigned int cflag = tty->termios.c_cflag;
1242 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1243 bool sw_changed = false;
1246 * Drivers doing software flow control also need to know
1247 * about changes to these input settings.
1249 if (uport->flags & UPF_SOFT_FLOW) {
1250 iflag_mask |= IXANY|IXON|IXOFF;
1252 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1253 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1257 * These are the bits that are used to setup various
1258 * flags in the low level driver. We can ignore the Bfoo
1259 * bits in c_cflag; c_[io]speed will always be set
1260 * appropriately by set_termios() in tty_ioctl.c
1262 if ((cflag ^ old_termios->c_cflag) == 0 &&
1263 tty->termios.c_ospeed == old_termios->c_ospeed &&
1264 tty->termios.c_ispeed == old_termios->c_ispeed &&
1265 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1270 uart_change_speed(tty, state, old_termios);
1272 /* Handle transition to B0 status */
1273 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1274 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1275 /* Handle transition away from B0 status */
1276 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1277 unsigned int mask = TIOCM_DTR;
1278 if (!(cflag & CRTSCTS) ||
1279 !test_bit(TTY_THROTTLED, &tty->flags))
1281 uart_set_mctrl(uport, mask);
1285 * If the port is doing h/w assisted flow control, do nothing.
1286 * We assume that tty->hw_stopped has never been set.
1288 if (uport->flags & UPF_HARD_FLOW)
1291 /* Handle turning off CRTSCTS */
1292 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1293 spin_lock_irqsave(&uport->lock, flags);
1294 tty->hw_stopped = 0;
1296 spin_unlock_irqrestore(&uport->lock, flags);
1298 /* Handle turning on CRTSCTS */
1299 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1300 spin_lock_irqsave(&uport->lock, flags);
1301 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1302 tty->hw_stopped = 1;
1303 uport->ops->stop_tx(uport);
1305 spin_unlock_irqrestore(&uport->lock, flags);
1310 * Calls to uart_close() are serialised via the tty_lock in
1311 * drivers/tty/tty_io.c:tty_release()
1312 * drivers/tty/tty_io.c:do_tty_hangup()
1313 * This runs from a workqueue and can sleep for a _short_ time only.
1315 static void uart_close(struct tty_struct *tty, struct file *filp)
1317 struct uart_state *state = tty->driver_data;
1318 struct tty_port *port;
1319 struct uart_port *uport;
1320 unsigned long flags;
1325 uport = state->uart_port;
1326 port = &state->port;
1328 pr_debug("uart_close(%d) called\n", uport->line);
1330 if (tty_port_close_start(port, tty, filp) == 0)
1334 * At this point, we stop accepting input. To do this, we
1335 * disable the receive line status interrupts.
1337 if (port->flags & ASYNC_INITIALIZED) {
1338 unsigned long flags;
1339 spin_lock_irqsave(&uport->lock, flags);
1340 uport->ops->stop_rx(uport);
1341 spin_unlock_irqrestore(&uport->lock, flags);
1343 * Before we drop DTR, make sure the UART transmitter
1344 * has completely drained; this is especially
1345 * important if there is a transmit FIFO!
1347 uart_wait_until_sent(tty, uport->timeout);
1350 mutex_lock(&port->mutex);
1351 uart_shutdown(tty, state);
1352 uart_flush_buffer(tty);
1354 tty_ldisc_flush(tty);
1356 tty_port_tty_set(port, NULL);
1357 spin_lock_irqsave(&port->lock, flags);
1360 if (port->blocked_open) {
1361 spin_unlock_irqrestore(&port->lock, flags);
1362 if (port->close_delay)
1363 msleep_interruptible(
1364 jiffies_to_msecs(port->close_delay));
1365 spin_lock_irqsave(&port->lock, flags);
1366 } else if (!uart_console(uport)) {
1367 spin_unlock_irqrestore(&port->lock, flags);
1368 uart_change_pm(state, UART_PM_STATE_OFF);
1369 spin_lock_irqsave(&port->lock, flags);
1373 * Wake up anyone trying to open this port.
1375 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1376 clear_bit(ASYNCB_CLOSING, &port->flags);
1377 spin_unlock_irqrestore(&port->lock, flags);
1378 wake_up_interruptible(&port->open_wait);
1379 wake_up_interruptible(&port->close_wait);
1381 mutex_unlock(&port->mutex);
1384 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1386 struct uart_state *state = tty->driver_data;
1387 struct uart_port *port = state->uart_port;
1388 unsigned long char_time, expire;
1390 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1394 * Set the check interval to be 1/5 of the estimated time to
1395 * send a single character, and make it at least 1. The check
1396 * interval should also be less than the timeout.
1398 * Note: we have to use pretty tight timings here to satisfy
1401 char_time = (port->timeout - HZ/50) / port->fifosize;
1402 char_time = char_time / 5;
1405 if (timeout && timeout < char_time)
1406 char_time = timeout;
1409 * If the transmitter hasn't cleared in twice the approximate
1410 * amount of time to send the entire FIFO, it probably won't
1411 * ever clear. This assumes the UART isn't doing flow
1412 * control, which is currently the case. Hence, if it ever
1413 * takes longer than port->timeout, this is probably due to a
1414 * UART bug of some kind. So, we clamp the timeout parameter at
1417 if (timeout == 0 || timeout > 2 * port->timeout)
1418 timeout = 2 * port->timeout;
1420 expire = jiffies + timeout;
1422 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1423 port->line, jiffies, expire);
1426 * Check whether the transmitter is empty every 'char_time'.
1427 * 'timeout' / 'expire' give us the maximum amount of time
1430 while (!port->ops->tx_empty(port)) {
1431 msleep_interruptible(jiffies_to_msecs(char_time));
1432 if (signal_pending(current))
1434 if (time_after(jiffies, expire))
1440 * Calls to uart_hangup() are serialised by the tty_lock in
1441 * drivers/tty/tty_io.c:do_tty_hangup()
1442 * This runs from a workqueue and can sleep for a _short_ time only.
1444 static void uart_hangup(struct tty_struct *tty)
1446 struct uart_state *state = tty->driver_data;
1447 struct tty_port *port = &state->port;
1448 unsigned long flags;
1450 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1452 mutex_lock(&port->mutex);
1453 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1454 uart_flush_buffer(tty);
1455 uart_shutdown(tty, state);
1456 spin_lock_irqsave(&port->lock, flags);
1458 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1459 spin_unlock_irqrestore(&port->lock, flags);
1460 tty_port_tty_set(port, NULL);
1461 wake_up_interruptible(&port->open_wait);
1462 wake_up_interruptible(&port->delta_msr_wait);
1464 mutex_unlock(&port->mutex);
1467 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1472 static void uart_port_shutdown(struct tty_port *port)
1474 struct uart_state *state = container_of(port, struct uart_state, port);
1475 struct uart_port *uport = state->uart_port;
1478 * clear delta_msr_wait queue to avoid mem leaks: we may free
1479 * the irq here so the queue might never be woken up. Note
1480 * that we won't end up waiting on delta_msr_wait again since
1481 * any outstanding file descriptors should be pointing at
1482 * hung_up_tty_fops now.
1484 wake_up_interruptible(&port->delta_msr_wait);
1487 * Free the IRQ and disable the port.
1489 uport->ops->shutdown(uport);
1492 * Ensure that the IRQ handler isn't running on another CPU.
1494 synchronize_irq(uport->irq);
1497 static int uart_carrier_raised(struct tty_port *port)
1499 struct uart_state *state = container_of(port, struct uart_state, port);
1500 struct uart_port *uport = state->uart_port;
1502 spin_lock_irq(&uport->lock);
1503 uport->ops->enable_ms(uport);
1504 mctrl = uport->ops->get_mctrl(uport);
1505 spin_unlock_irq(&uport->lock);
1506 if (mctrl & TIOCM_CAR)
1511 static void uart_dtr_rts(struct tty_port *port, int onoff)
1513 struct uart_state *state = container_of(port, struct uart_state, port);
1514 struct uart_port *uport = state->uart_port;
1517 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1519 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1523 * Calls to uart_open are serialised by the tty_lock in
1524 * drivers/tty/tty_io.c:tty_open()
1525 * Note that if this fails, then uart_close() _will_ be called.
1527 * In time, we want to scrap the "opening nonpresent ports"
1528 * behaviour and implement an alternative way for setserial
1529 * to set base addresses/ports/types. This will allow us to
1530 * get rid of a certain amount of extra tests.
1532 static int uart_open(struct tty_struct *tty, struct file *filp)
1534 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1535 int retval, line = tty->index;
1536 struct uart_state *state = drv->state + line;
1537 struct tty_port *port = &state->port;
1539 pr_debug("uart_open(%d) called\n", line);
1542 * We take the semaphore here to guarantee that we won't be re-entered
1543 * while allocating the state structure, or while we request any IRQs
1544 * that the driver may need. This also has the nice side-effect that
1545 * it delays the action of uart_hangup, so we can guarantee that
1546 * state->port.tty will always contain something reasonable.
1548 if (mutex_lock_interruptible(&port->mutex)) {
1549 retval = -ERESTARTSYS;
1554 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1560 * Once we set tty->driver_data here, we are guaranteed that
1561 * uart_close() will decrement the driver module use count.
1562 * Any failures from here onwards should not touch the count.
1564 tty->driver_data = state;
1565 state->uart_port->state = state;
1566 state->port.low_latency =
1567 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1568 tty_port_tty_set(port, tty);
1571 * If the port is in the middle of closing, bail out now.
1573 if (tty_hung_up_p(filp)) {
1579 * Make sure the device is in D0 state.
1581 if (port->count == 1)
1582 uart_change_pm(state, UART_PM_STATE_ON);
1585 * Start up the serial port.
1587 retval = uart_startup(tty, state, 0);
1590 * If we succeeded, wait until the port is ready.
1592 mutex_unlock(&port->mutex);
1594 retval = tty_port_block_til_ready(port, tty, filp);
1600 mutex_unlock(&port->mutex);
1604 static const char *uart_type(struct uart_port *port)
1606 const char *str = NULL;
1608 if (port->ops->type)
1609 str = port->ops->type(port);
1617 #ifdef CONFIG_PROC_FS
1619 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1621 struct uart_state *state = drv->state + i;
1622 struct tty_port *port = &state->port;
1623 enum uart_pm_state pm_state;
1624 struct uart_port *uport = state->uart_port;
1626 unsigned int status;
1632 mmio = uport->iotype >= UPIO_MEM;
1633 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1634 uport->line, uart_type(uport),
1635 mmio ? "mmio:0x" : "port:",
1636 mmio ? (unsigned long long)uport->mapbase
1637 : (unsigned long long)uport->iobase,
1640 if (uport->type == PORT_UNKNOWN) {
1645 if (capable(CAP_SYS_ADMIN)) {
1646 mutex_lock(&port->mutex);
1647 pm_state = state->pm_state;
1648 if (pm_state != UART_PM_STATE_ON)
1649 uart_change_pm(state, UART_PM_STATE_ON);
1650 spin_lock_irq(&uport->lock);
1651 status = uport->ops->get_mctrl(uport);
1652 spin_unlock_irq(&uport->lock);
1653 if (pm_state != UART_PM_STATE_ON)
1654 uart_change_pm(state, pm_state);
1655 mutex_unlock(&port->mutex);
1657 seq_printf(m, " tx:%d rx:%d",
1658 uport->icount.tx, uport->icount.rx);
1659 if (uport->icount.frame)
1660 seq_printf(m, " fe:%d",
1661 uport->icount.frame);
1662 if (uport->icount.parity)
1663 seq_printf(m, " pe:%d",
1664 uport->icount.parity);
1665 if (uport->icount.brk)
1666 seq_printf(m, " brk:%d",
1668 if (uport->icount.overrun)
1669 seq_printf(m, " oe:%d",
1670 uport->icount.overrun);
1672 #define INFOBIT(bit, str) \
1673 if (uport->mctrl & (bit)) \
1674 strncat(stat_buf, (str), sizeof(stat_buf) - \
1675 strlen(stat_buf) - 2)
1676 #define STATBIT(bit, str) \
1677 if (status & (bit)) \
1678 strncat(stat_buf, (str), sizeof(stat_buf) - \
1679 strlen(stat_buf) - 2)
1683 INFOBIT(TIOCM_RTS, "|RTS");
1684 STATBIT(TIOCM_CTS, "|CTS");
1685 INFOBIT(TIOCM_DTR, "|DTR");
1686 STATBIT(TIOCM_DSR, "|DSR");
1687 STATBIT(TIOCM_CAR, "|CD");
1688 STATBIT(TIOCM_RNG, "|RI");
1692 seq_puts(m, stat_buf);
1699 static int uart_proc_show(struct seq_file *m, void *v)
1701 struct tty_driver *ttydrv = m->private;
1702 struct uart_driver *drv = ttydrv->driver_state;
1705 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1707 for (i = 0; i < drv->nr; i++)
1708 uart_line_info(m, drv, i);
1712 static int uart_proc_open(struct inode *inode, struct file *file)
1714 return single_open(file, uart_proc_show, PDE_DATA(inode));
1717 static const struct file_operations uart_proc_fops = {
1718 .owner = THIS_MODULE,
1719 .open = uart_proc_open,
1721 .llseek = seq_lseek,
1722 .release = single_release,
1726 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1728 * uart_console_write - write a console message to a serial port
1729 * @port: the port to write the message
1730 * @s: array of characters
1731 * @count: number of characters in string to write
1732 * @write: function to write character to port
1734 void uart_console_write(struct uart_port *port, const char *s,
1736 void (*putchar)(struct uart_port *, int))
1740 for (i = 0; i < count; i++, s++) {
1742 putchar(port, '\r');
1746 EXPORT_SYMBOL_GPL(uart_console_write);
1749 * Check whether an invalid uart number has been specified, and
1750 * if so, search for the first available port that does have
1753 struct uart_port * __init
1754 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1756 int idx = co->index;
1758 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1759 ports[idx].membase == NULL))
1760 for (idx = 0; idx < nr; idx++)
1761 if (ports[idx].iobase != 0 ||
1762 ports[idx].membase != NULL)
1771 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1772 * @options: pointer to option string
1773 * @baud: pointer to an 'int' variable for the baud rate.
1774 * @parity: pointer to an 'int' variable for the parity.
1775 * @bits: pointer to an 'int' variable for the number of data bits.
1776 * @flow: pointer to an 'int' variable for the flow control character.
1778 * uart_parse_options decodes a string containing the serial console
1779 * options. The format of the string is <baud><parity><bits><flow>,
1783 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1787 *baud = simple_strtoul(s, NULL, 10);
1788 while (*s >= '0' && *s <= '9')
1797 EXPORT_SYMBOL_GPL(uart_parse_options);
1804 static const struct baud_rates baud_rates[] = {
1805 { 921600, B921600 },
1806 { 460800, B460800 },
1807 { 230400, B230400 },
1808 { 115200, B115200 },
1820 * uart_set_options - setup the serial console parameters
1821 * @port: pointer to the serial ports uart_port structure
1822 * @co: console pointer
1824 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1825 * @bits: number of data bits
1826 * @flow: flow control character - 'r' (rts)
1829 uart_set_options(struct uart_port *port, struct console *co,
1830 int baud, int parity, int bits, int flow)
1832 struct ktermios termios;
1833 static struct ktermios dummy;
1837 * Ensure that the serial console lock is initialised
1840 spin_lock_init(&port->lock);
1841 lockdep_set_class(&port->lock, &port_lock_key);
1843 memset(&termios, 0, sizeof(struct ktermios));
1845 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1848 * Construct a cflag setting.
1850 for (i = 0; baud_rates[i].rate; i++)
1851 if (baud_rates[i].rate <= baud)
1854 termios.c_cflag |= baud_rates[i].cflag;
1857 termios.c_cflag |= CS7;
1859 termios.c_cflag |= CS8;
1863 termios.c_cflag |= PARODD;
1866 termios.c_cflag |= PARENB;
1871 termios.c_cflag |= CRTSCTS;
1874 * some uarts on other side don't support no flow control.
1875 * So we set * DTR in host uart to make them happy
1877 port->mctrl |= TIOCM_DTR;
1879 port->ops->set_termios(port, &termios, &dummy);
1881 * Allow the setting of the UART parameters with a NULL console
1885 co->cflag = termios.c_cflag;
1889 EXPORT_SYMBOL_GPL(uart_set_options);
1890 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1893 * uart_change_pm - set power state of the port
1895 * @state: port descriptor
1896 * @pm_state: new state
1898 * Locking: port->mutex has to be held
1900 static void uart_change_pm(struct uart_state *state,
1901 enum uart_pm_state pm_state)
1903 struct uart_port *port = state->uart_port;
1905 if (state->pm_state != pm_state) {
1907 port->ops->pm(port, pm_state, state->pm_state);
1908 state->pm_state = pm_state;
1913 struct uart_port *port;
1914 struct uart_driver *driver;
1917 static int serial_match_port(struct device *dev, void *data)
1919 struct uart_match *match = data;
1920 struct tty_driver *tty_drv = match->driver->tty_driver;
1921 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1924 return dev->devt == devt; /* Actually, only one tty per port */
1927 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1929 struct uart_state *state = drv->state + uport->line;
1930 struct tty_port *port = &state->port;
1931 struct device *tty_dev;
1932 struct uart_match match = {uport, drv};
1934 mutex_lock(&port->mutex);
1936 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1937 if (device_may_wakeup(tty_dev)) {
1938 if (!enable_irq_wake(uport->irq))
1939 uport->irq_wake = 1;
1940 put_device(tty_dev);
1941 mutex_unlock(&port->mutex);
1944 put_device(tty_dev);
1946 if (console_suspend_enabled || !uart_console(uport))
1947 uport->suspended = 1;
1949 if (port->flags & ASYNC_INITIALIZED) {
1950 const struct uart_ops *ops = uport->ops;
1953 if (console_suspend_enabled || !uart_console(uport)) {
1954 set_bit(ASYNCB_SUSPENDED, &port->flags);
1955 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1957 spin_lock_irq(&uport->lock);
1958 ops->stop_tx(uport);
1959 ops->set_mctrl(uport, 0);
1960 ops->stop_rx(uport);
1961 spin_unlock_irq(&uport->lock);
1965 * Wait for the transmitter to empty.
1967 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1970 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1972 uport->dev ? dev_name(uport->dev) : "",
1973 uport->dev ? ": " : "",
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 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2105 port->dev ? dev_name(port->dev) : "",
2106 port->dev ? ": " : "",
2108 drv->tty_driver->name_base + port->line,
2109 address, port->irq, uart_type(port));
2113 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2114 struct uart_port *port)
2119 * If there isn't a port here, don't do anything further.
2121 if (!port->iobase && !port->mapbase && !port->membase)
2125 * Now do the auto configuration stuff. Note that config_port
2126 * is expected to claim the resources and map the port for us.
2129 if (port->flags & UPF_AUTO_IRQ)
2130 flags |= UART_CONFIG_IRQ;
2131 if (port->flags & UPF_BOOT_AUTOCONF) {
2132 if (!(port->flags & UPF_FIXED_TYPE)) {
2133 port->type = PORT_UNKNOWN;
2134 flags |= UART_CONFIG_TYPE;
2136 port->ops->config_port(port, flags);
2139 if (port->type != PORT_UNKNOWN) {
2140 unsigned long flags;
2142 uart_report_port(drv, port);
2144 /* Power up port for set_mctrl() */
2145 uart_change_pm(state, UART_PM_STATE_ON);
2148 * Ensure that the modem control lines are de-activated.
2149 * keep the DTR setting that is set in uart_set_options()
2150 * We probably don't need a spinlock around this, but
2152 spin_lock_irqsave(&port->lock, flags);
2153 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2154 spin_unlock_irqrestore(&port->lock, flags);
2157 * If this driver supports console, and it hasn't been
2158 * successfully registered yet, try to re-register it.
2159 * It may be that the port was not available.
2161 if (port->cons && !(port->cons->flags & CON_ENABLED))
2162 register_console(port->cons);
2165 * Power down all ports by default, except the
2166 * console if we have one.
2168 if (!uart_console(port))
2169 uart_change_pm(state, UART_PM_STATE_OFF);
2173 #ifdef CONFIG_CONSOLE_POLL
2175 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2177 struct uart_driver *drv = driver->driver_state;
2178 struct uart_state *state = drv->state + line;
2179 struct uart_port *port;
2186 if (!state || !state->uart_port)
2189 port = state->uart_port;
2190 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2193 if (port->ops->poll_init) {
2194 struct tty_port *tport = &state->port;
2197 mutex_lock(&tport->mutex);
2199 * We don't set ASYNCB_INITIALIZED as we only initialized the
2200 * hw, e.g. state->xmit is still uninitialized.
2202 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2203 ret = port->ops->poll_init(port);
2204 mutex_unlock(&tport->mutex);
2210 uart_parse_options(options, &baud, &parity, &bits, &flow);
2211 return uart_set_options(port, NULL, baud, parity, bits, flow);
2217 static int uart_poll_get_char(struct tty_driver *driver, int line)
2219 struct uart_driver *drv = driver->driver_state;
2220 struct uart_state *state = drv->state + line;
2221 struct uart_port *port;
2223 if (!state || !state->uart_port)
2226 port = state->uart_port;
2227 return port->ops->poll_get_char(port);
2230 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2232 struct uart_driver *drv = driver->driver_state;
2233 struct uart_state *state = drv->state + line;
2234 struct uart_port *port;
2236 if (!state || !state->uart_port)
2239 port = state->uart_port;
2240 port->ops->poll_put_char(port, ch);
2244 static const struct tty_operations uart_ops = {
2246 .close = uart_close,
2247 .write = uart_write,
2248 .put_char = uart_put_char,
2249 .flush_chars = uart_flush_chars,
2250 .write_room = uart_write_room,
2251 .chars_in_buffer= uart_chars_in_buffer,
2252 .flush_buffer = uart_flush_buffer,
2253 .ioctl = uart_ioctl,
2254 .throttle = uart_throttle,
2255 .unthrottle = uart_unthrottle,
2256 .send_xchar = uart_send_xchar,
2257 .set_termios = uart_set_termios,
2258 .set_ldisc = uart_set_ldisc,
2260 .start = uart_start,
2261 .hangup = uart_hangup,
2262 .break_ctl = uart_break_ctl,
2263 .wait_until_sent= uart_wait_until_sent,
2264 #ifdef CONFIG_PROC_FS
2265 .proc_fops = &uart_proc_fops,
2267 .tiocmget = uart_tiocmget,
2268 .tiocmset = uart_tiocmset,
2269 .get_icount = uart_get_icount,
2270 #ifdef CONFIG_CONSOLE_POLL
2271 .poll_init = uart_poll_init,
2272 .poll_get_char = uart_poll_get_char,
2273 .poll_put_char = uart_poll_put_char,
2277 static const struct tty_port_operations uart_port_ops = {
2278 .activate = uart_port_activate,
2279 .shutdown = uart_port_shutdown,
2280 .carrier_raised = uart_carrier_raised,
2281 .dtr_rts = uart_dtr_rts,
2285 * uart_register_driver - register a driver with the uart core layer
2286 * @drv: low level driver structure
2288 * Register a uart driver with the core driver. We in turn register
2289 * with the tty layer, and initialise the core driver per-port state.
2291 * We have a proc file in /proc/tty/driver which is named after the
2294 * drv->port should be NULL, and the per-port structures should be
2295 * registered using uart_add_one_port after this call has succeeded.
2297 int uart_register_driver(struct uart_driver *drv)
2299 struct tty_driver *normal;
2305 * Maybe we should be using a slab cache for this, especially if
2306 * we have a large number of ports to handle.
2308 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2312 normal = alloc_tty_driver(drv->nr);
2316 drv->tty_driver = normal;
2318 normal->driver_name = drv->driver_name;
2319 normal->name = drv->dev_name;
2320 normal->major = drv->major;
2321 normal->minor_start = drv->minor;
2322 normal->type = TTY_DRIVER_TYPE_SERIAL;
2323 normal->subtype = SERIAL_TYPE_NORMAL;
2324 normal->init_termios = tty_std_termios;
2325 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2326 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2327 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2328 normal->driver_state = drv;
2329 tty_set_operations(normal, &uart_ops);
2332 * Initialise the UART state(s).
2334 for (i = 0; i < drv->nr; i++) {
2335 struct uart_state *state = drv->state + i;
2336 struct tty_port *port = &state->port;
2338 tty_port_init(port);
2339 port->ops = &uart_port_ops;
2340 port->close_delay = HZ / 2; /* .5 seconds */
2341 port->closing_wait = 30 * HZ;/* 30 seconds */
2344 retval = tty_register_driver(normal);
2348 for (i = 0; i < drv->nr; i++)
2349 tty_port_destroy(&drv->state[i].port);
2350 put_tty_driver(normal);
2358 * uart_unregister_driver - remove a driver from the uart core layer
2359 * @drv: low level driver structure
2361 * Remove all references to a driver from the core driver. The low
2362 * level driver must have removed all its ports via the
2363 * uart_remove_one_port() if it registered them with uart_add_one_port().
2364 * (ie, drv->port == NULL)
2366 void uart_unregister_driver(struct uart_driver *drv)
2368 struct tty_driver *p = drv->tty_driver;
2371 tty_unregister_driver(p);
2373 for (i = 0; i < drv->nr; i++)
2374 tty_port_destroy(&drv->state[i].port);
2377 drv->tty_driver = NULL;
2380 struct tty_driver *uart_console_device(struct console *co, int *index)
2382 struct uart_driver *p = co->data;
2384 return p->tty_driver;
2387 static ssize_t uart_get_attr_uartclk(struct device *dev,
2388 struct device_attribute *attr, char *buf)
2390 struct serial_struct tmp;
2391 struct tty_port *port = dev_get_drvdata(dev);
2393 uart_get_info(port, &tmp);
2394 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2397 static ssize_t uart_get_attr_type(struct device *dev,
2398 struct device_attribute *attr, char *buf)
2400 struct serial_struct tmp;
2401 struct tty_port *port = dev_get_drvdata(dev);
2403 uart_get_info(port, &tmp);
2404 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2406 static ssize_t uart_get_attr_line(struct device *dev,
2407 struct device_attribute *attr, char *buf)
2409 struct serial_struct tmp;
2410 struct tty_port *port = dev_get_drvdata(dev);
2412 uart_get_info(port, &tmp);
2413 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2416 static ssize_t uart_get_attr_port(struct device *dev,
2417 struct device_attribute *attr, char *buf)
2419 struct serial_struct tmp;
2420 struct tty_port *port = dev_get_drvdata(dev);
2421 unsigned long ioaddr;
2423 uart_get_info(port, &tmp);
2425 if (HIGH_BITS_OFFSET)
2426 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2427 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2430 static ssize_t uart_get_attr_irq(struct device *dev,
2431 struct device_attribute *attr, char *buf)
2433 struct serial_struct tmp;
2434 struct tty_port *port = dev_get_drvdata(dev);
2436 uart_get_info(port, &tmp);
2437 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2440 static ssize_t uart_get_attr_flags(struct device *dev,
2441 struct device_attribute *attr, char *buf)
2443 struct serial_struct tmp;
2444 struct tty_port *port = dev_get_drvdata(dev);
2446 uart_get_info(port, &tmp);
2447 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2450 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2451 struct device_attribute *attr, char *buf)
2453 struct serial_struct tmp;
2454 struct tty_port *port = dev_get_drvdata(dev);
2456 uart_get_info(port, &tmp);
2457 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2461 static ssize_t uart_get_attr_close_delay(struct device *dev,
2462 struct device_attribute *attr, char *buf)
2464 struct serial_struct tmp;
2465 struct tty_port *port = dev_get_drvdata(dev);
2467 uart_get_info(port, &tmp);
2468 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2472 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2473 struct device_attribute *attr, char *buf)
2475 struct serial_struct tmp;
2476 struct tty_port *port = dev_get_drvdata(dev);
2478 uart_get_info(port, &tmp);
2479 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2482 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2483 struct device_attribute *attr, char *buf)
2485 struct serial_struct tmp;
2486 struct tty_port *port = dev_get_drvdata(dev);
2488 uart_get_info(port, &tmp);
2489 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2492 static ssize_t uart_get_attr_io_type(struct device *dev,
2493 struct device_attribute *attr, char *buf)
2495 struct serial_struct tmp;
2496 struct tty_port *port = dev_get_drvdata(dev);
2498 uart_get_info(port, &tmp);
2499 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2502 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2503 struct device_attribute *attr, char *buf)
2505 struct serial_struct tmp;
2506 struct tty_port *port = dev_get_drvdata(dev);
2508 uart_get_info(port, &tmp);
2509 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2512 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2513 struct device_attribute *attr, char *buf)
2515 struct serial_struct tmp;
2516 struct tty_port *port = dev_get_drvdata(dev);
2518 uart_get_info(port, &tmp);
2519 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2522 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2523 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2524 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2525 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2526 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2527 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2528 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2529 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2530 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2531 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2532 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2533 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2534 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2536 static struct attribute *tty_dev_attrs[] = {
2537 &dev_attr_type.attr,
2538 &dev_attr_line.attr,
2539 &dev_attr_port.attr,
2541 &dev_attr_flags.attr,
2542 &dev_attr_xmit_fifo_size.attr,
2543 &dev_attr_uartclk.attr,
2544 &dev_attr_close_delay.attr,
2545 &dev_attr_closing_wait.attr,
2546 &dev_attr_custom_divisor.attr,
2547 &dev_attr_io_type.attr,
2548 &dev_attr_iomem_base.attr,
2549 &dev_attr_iomem_reg_shift.attr,
2553 static const struct attribute_group tty_dev_attr_group = {
2554 .attrs = tty_dev_attrs,
2557 static const struct attribute_group *tty_dev_attr_groups[] = {
2558 &tty_dev_attr_group,
2564 * uart_add_one_port - attach a driver-defined port structure
2565 * @drv: pointer to the uart low level driver structure for this port
2566 * @uport: uart port structure to use for this port.
2568 * This allows the driver to register its own uart_port structure
2569 * with the core driver. The main purpose is to allow the low
2570 * level uart drivers to expand uart_port, rather than having yet
2571 * more levels of structures.
2573 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2575 struct uart_state *state;
2576 struct tty_port *port;
2578 struct device *tty_dev;
2580 BUG_ON(in_interrupt());
2582 if (uport->line >= drv->nr)
2585 state = drv->state + uport->line;
2586 port = &state->port;
2588 mutex_lock(&port_mutex);
2589 mutex_lock(&port->mutex);
2590 if (state->uart_port) {
2595 state->uart_port = uport;
2596 state->pm_state = UART_PM_STATE_UNDEFINED;
2598 uport->cons = drv->cons;
2599 uport->state = state;
2602 * If this port is a console, then the spinlock is already
2605 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2606 spin_lock_init(&uport->lock);
2607 lockdep_set_class(&uport->lock, &port_lock_key);
2610 uart_configure_port(drv, state, uport);
2613 * Register the port whether it's detected or not. This allows
2614 * setserial to be used to alter this ports parameters.
2616 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2617 uport->line, uport->dev, port, tty_dev_attr_groups);
2618 if (likely(!IS_ERR(tty_dev))) {
2619 device_set_wakeup_capable(tty_dev, 1);
2621 printk(KERN_ERR "Cannot register tty device on line %d\n",
2626 * Ensure UPF_DEAD is not set.
2628 uport->flags &= ~UPF_DEAD;
2631 mutex_unlock(&port->mutex);
2632 mutex_unlock(&port_mutex);
2638 * uart_remove_one_port - detach a driver defined port structure
2639 * @drv: pointer to the uart low level driver structure for this port
2640 * @uport: uart port structure for this port
2642 * This unhooks (and hangs up) the specified port structure from the
2643 * core driver. No further calls will be made to the low-level code
2646 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2648 struct uart_state *state = drv->state + uport->line;
2649 struct tty_port *port = &state->port;
2652 BUG_ON(in_interrupt());
2654 if (state->uart_port != uport)
2655 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2656 state->uart_port, uport);
2658 mutex_lock(&port_mutex);
2661 * Mark the port "dead" - this prevents any opens from
2662 * succeeding while we shut down the port.
2664 mutex_lock(&port->mutex);
2665 if (!state->uart_port) {
2666 mutex_unlock(&port->mutex);
2670 uport->flags |= UPF_DEAD;
2671 mutex_unlock(&port->mutex);
2674 * Remove the devices from the tty layer
2676 tty_unregister_device(drv->tty_driver, uport->line);
2679 tty_vhangup(port->tty);
2682 * Free the port IO and memory resources, if any.
2684 if (uport->type != PORT_UNKNOWN)
2685 uport->ops->release_port(uport);
2688 * Indicate that there isn't a port here anymore.
2690 uport->type = PORT_UNKNOWN;
2692 state->uart_port = NULL;
2694 mutex_unlock(&port_mutex);
2700 * Are the two ports equivalent?
2702 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2704 if (port1->iotype != port2->iotype)
2707 switch (port1->iotype) {
2709 return (port1->iobase == port2->iobase);
2711 return (port1->iobase == port2->iobase) &&
2712 (port1->hub6 == port2->hub6);
2717 return (port1->mapbase == port2->mapbase);
2721 EXPORT_SYMBOL(uart_match_port);
2724 * uart_handle_dcd_change - handle a change of carrier detect state
2725 * @uport: uart_port structure for the open port
2726 * @status: new carrier detect status, nonzero if active
2728 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2730 struct tty_port *port = &uport->state->port;
2731 struct tty_struct *tty = port->tty;
2732 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2735 if (ld->ops->dcd_change)
2736 ld->ops->dcd_change(tty, status);
2737 tty_ldisc_deref(ld);
2740 uport->icount.dcd++;
2742 if (port->flags & ASYNC_CHECK_CD) {
2744 wake_up_interruptible(&port->open_wait);
2749 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2752 * uart_handle_cts_change - handle a change of clear-to-send state
2753 * @uport: uart_port structure for the open port
2754 * @status: new clear to send status, nonzero if active
2756 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2758 struct tty_port *port = &uport->state->port;
2759 struct tty_struct *tty = port->tty;
2761 uport->icount.cts++;
2763 if (tty_port_cts_enabled(port)) {
2764 if (tty->hw_stopped) {
2766 tty->hw_stopped = 0;
2767 uport->ops->start_tx(uport);
2768 uart_write_wakeup(uport);
2772 tty->hw_stopped = 1;
2773 uport->ops->stop_tx(uport);
2778 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2781 * uart_insert_char - push a char to the uart layer
2783 * User is responsible to call tty_flip_buffer_push when they are done with
2786 * @port: corresponding port
2787 * @status: state of the serial port RX buffer (LSR for 8250)
2788 * @overrun: mask of overrun bits in @status
2789 * @ch: character to push
2790 * @flag: flag for the character (see TTY_NORMAL and friends)
2792 void uart_insert_char(struct uart_port *port, unsigned int status,
2793 unsigned int overrun, unsigned int ch, unsigned int flag)
2795 struct tty_port *tport = &port->state->port;
2797 if ((status & port->ignore_status_mask & ~overrun) == 0)
2798 if (tty_insert_flip_char(tport, ch, flag) == 0)
2799 ++port->icount.buf_overrun;
2802 * Overrun is special. Since it's reported immediately,
2803 * it doesn't affect the current character.
2805 if (status & ~port->ignore_status_mask & overrun)
2806 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2807 ++port->icount.buf_overrun;
2809 EXPORT_SYMBOL_GPL(uart_insert_char);
2811 EXPORT_SYMBOL(uart_write_wakeup);
2812 EXPORT_SYMBOL(uart_register_driver);
2813 EXPORT_SYMBOL(uart_unregister_driver);
2814 EXPORT_SYMBOL(uart_suspend_port);
2815 EXPORT_SYMBOL(uart_resume_port);
2816 EXPORT_SYMBOL(uart_add_one_port);
2817 EXPORT_SYMBOL(uart_remove_one_port);
2819 MODULE_DESCRIPTION("Serial driver core");
2820 MODULE_LICENSE("GPL");