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);
62 static int uart_dcd_enabled(struct uart_port *uport)
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
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_tx_stopped(port))
99 port->ops->start_tx(port);
102 static void uart_start(struct tty_struct *tty)
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
108 spin_lock_irqsave(&port->lock, flags);
110 spin_unlock_irqrestore(&port->lock, flags);
114 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
119 spin_lock_irqsave(&port->lock, flags);
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
127 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
134 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
137 struct uart_port *uport = state->uart_port;
141 if (uport->type == PORT_UNKNOWN)
145 * Make sure the device is in D0 state.
147 uart_change_pm(state, UART_PM_STATE_ON);
150 * Initialise and allocate the transmit and temporary
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
163 retval = uport->ops->startup(uport);
165 if (uart_console(uport) && uport->cons->cflag) {
166 tty->termios.c_cflag = uport->cons->cflag;
167 uport->cons->cflag = 0;
170 * Initialise the hardware port settings.
172 uart_change_speed(tty, state, NULL);
176 * Setup the RTS and DTR signals once the
177 * port is open and ready to respond.
179 if (tty->termios.c_cflag & CBAUD)
180 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
185 * This is to allow setserial on this port. People may want to set
186 * port/irq/type and then reconfigure the port properly if it failed
189 if (retval && capable(CAP_SYS_ADMIN))
195 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
198 struct tty_port *port = &state->port;
201 if (port->flags & ASYNC_INITIALIZED)
205 * Set the TTY IO error marker - we will only clear this
206 * once we have successfully opened the port.
208 set_bit(TTY_IO_ERROR, &tty->flags);
210 retval = uart_port_startup(tty, state, init_hw);
212 set_bit(ASYNCB_INITIALIZED, &port->flags);
213 clear_bit(TTY_IO_ERROR, &tty->flags);
214 } else if (retval > 0)
221 * This routine will shutdown a serial port; interrupts are disabled, and
222 * DTR is dropped if the hangup on close termio flag is on. Calls to
223 * uart_shutdown are serialised by the per-port semaphore.
225 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
227 struct uart_port *uport = state->uart_port;
228 struct tty_port *port = &state->port;
231 * Set the TTY IO error marker
234 set_bit(TTY_IO_ERROR, &tty->flags);
236 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
238 * Turn off DTR and RTS early.
240 if (uart_console(uport) && tty)
241 uport->cons->cflag = tty->termios.c_cflag;
243 if (!tty || (tty->termios.c_cflag & HUPCL))
244 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
246 uart_port_shutdown(port);
250 * It's possible for shutdown to be called after suspend if we get
251 * a DCD drop (hangup) at just the right time. Clear suspended bit so
252 * we don't try to resume a port that has been shutdown.
254 clear_bit(ASYNCB_SUSPENDED, &port->flags);
257 * Free the transmit buffer page.
259 if (state->xmit.buf) {
260 free_page((unsigned long)state->xmit.buf);
261 state->xmit.buf = NULL;
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
275 uart_update_timeout(struct uart_port *port, unsigned int cflag,
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
302 * The total number of bits to be transmitted in the fifo.
304 bits = bits * port->fifosize;
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
310 port->timeout = (HZ * bits) / baud + HZ/50;
313 EXPORT_SYMBOL(uart_update_timeout);
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using. Don't do this for the case
332 * where B0 is requested ("hang up").
335 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min, unsigned int max)
340 unsigned int altbaud;
342 upf_t flags = port->flags & UPF_SPD_MASK;
362 for (try = 0; try < 2; try++) {
363 baud = tty_termios_baud_rate(termios);
366 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
369 if (try == 0 && baud == 38400)
373 * Special case: B0 rate.
380 if (baud >= min && baud <= max)
384 * Oops, the quotient was zero. Try again with
385 * the old baud rate if possible.
387 termios->c_cflag &= ~CBAUD;
389 baud = tty_termios_baud_rate(old);
391 tty_termios_encode_baud_rate(termios,
398 * As a last resort, if the range cannot be met then clip to
399 * the nearest chip supported rate.
403 tty_termios_encode_baud_rate(termios,
406 tty_termios_encode_baud_rate(termios,
410 /* Should never happen */
415 EXPORT_SYMBOL(uart_get_baud_rate);
418 * uart_get_divisor - return uart clock divisor
419 * @port: uart_port structure describing the port.
420 * @baud: desired baud rate
422 * Calculate the uart clock divisor for the port.
425 uart_get_divisor(struct uart_port *port, unsigned int baud)
430 * Old custom speed handling.
432 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
433 quot = port->custom_divisor;
435 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
440 EXPORT_SYMBOL(uart_get_divisor);
442 /* Caller holds port mutex */
443 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
444 struct ktermios *old_termios)
446 struct uart_port *uport = state->uart_port;
447 struct ktermios *termios;
451 * If we have no tty, termios, or the port does not exist,
452 * then we can't set the parameters for this port.
454 if (!tty || uport->type == PORT_UNKNOWN)
457 termios = &tty->termios;
458 uport->ops->set_termios(uport, termios, old_termios);
461 * Set modem status enables based on termios cflag
463 spin_lock_irq(&uport->lock);
464 if (termios->c_cflag & CRTSCTS)
465 uport->status |= UPSTAT_CTS_ENABLE;
467 uport->status &= ~UPSTAT_CTS_ENABLE;
469 if (termios->c_cflag & CLOCAL)
470 uport->status &= ~UPSTAT_DCD_ENABLE;
472 uport->status |= UPSTAT_DCD_ENABLE;
474 /* reset sw-assisted CTS flow control based on (possibly) new mode */
475 hw_stopped = uport->hw_stopped;
476 uport->hw_stopped = uart_softcts_mode(uport) &&
477 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
478 if (uport->hw_stopped) {
480 uport->ops->stop_tx(uport);
485 spin_unlock_irq(&uport->lock);
488 static inline int __uart_put_char(struct uart_port *port,
489 struct circ_buf *circ, unsigned char c)
497 spin_lock_irqsave(&port->lock, flags);
498 if (uart_circ_chars_free(circ) != 0) {
499 circ->buf[circ->head] = c;
500 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
503 spin_unlock_irqrestore(&port->lock, flags);
507 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
509 struct uart_state *state = tty->driver_data;
511 return __uart_put_char(state->uart_port, &state->xmit, ch);
514 static void uart_flush_chars(struct tty_struct *tty)
519 static int uart_write(struct tty_struct *tty,
520 const unsigned char *buf, int count)
522 struct uart_state *state = tty->driver_data;
523 struct uart_port *port;
524 struct circ_buf *circ;
529 * This means you called this function _after_ the port was
530 * closed. No cookie for you.
537 port = state->uart_port;
543 spin_lock_irqsave(&port->lock, flags);
545 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
550 memcpy(circ->buf + circ->head, buf, c);
551 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
558 spin_unlock_irqrestore(&port->lock, flags);
563 static int uart_write_room(struct tty_struct *tty)
565 struct uart_state *state = tty->driver_data;
569 spin_lock_irqsave(&state->uart_port->lock, flags);
570 ret = uart_circ_chars_free(&state->xmit);
571 spin_unlock_irqrestore(&state->uart_port->lock, flags);
575 static int uart_chars_in_buffer(struct tty_struct *tty)
577 struct uart_state *state = tty->driver_data;
581 spin_lock_irqsave(&state->uart_port->lock, flags);
582 ret = uart_circ_chars_pending(&state->xmit);
583 spin_unlock_irqrestore(&state->uart_port->lock, flags);
587 static void uart_flush_buffer(struct tty_struct *tty)
589 struct uart_state *state = tty->driver_data;
590 struct uart_port *port;
594 * This means you called this function _after_ the port was
595 * closed. No cookie for you.
602 port = state->uart_port;
603 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
605 spin_lock_irqsave(&port->lock, flags);
606 uart_circ_clear(&state->xmit);
607 if (port->ops->flush_buffer)
608 port->ops->flush_buffer(port);
609 spin_unlock_irqrestore(&port->lock, flags);
614 * This function is used to send a high-priority XON/XOFF character to
617 static void uart_send_xchar(struct tty_struct *tty, char ch)
619 struct uart_state *state = tty->driver_data;
620 struct uart_port *port = state->uart_port;
623 if (port->ops->send_xchar)
624 port->ops->send_xchar(port, ch);
626 spin_lock_irqsave(&port->lock, flags);
629 port->ops->start_tx(port);
630 spin_unlock_irqrestore(&port->lock, flags);
634 static void uart_throttle(struct tty_struct *tty)
636 struct uart_state *state = tty->driver_data;
637 struct uart_port *port = state->uart_port;
641 mask |= UPSTAT_AUTOXOFF;
642 if (tty->termios.c_cflag & CRTSCTS)
643 mask |= UPSTAT_AUTORTS;
645 if (port->status & mask) {
646 port->ops->throttle(port);
647 mask &= ~port->status;
650 if (mask & UPSTAT_AUTOXOFF)
651 uart_send_xchar(tty, STOP_CHAR(tty));
653 if (mask & UPSTAT_AUTORTS)
654 uart_clear_mctrl(port, TIOCM_RTS);
657 static void uart_unthrottle(struct tty_struct *tty)
659 struct uart_state *state = tty->driver_data;
660 struct uart_port *port = state->uart_port;
664 mask |= UPSTAT_AUTOXOFF;
665 if (tty->termios.c_cflag & CRTSCTS)
666 mask |= UPSTAT_AUTORTS;
668 if (port->status & mask) {
669 port->ops->unthrottle(port);
670 mask &= ~port->status;
673 if (mask & UPSTAT_AUTOXOFF)
674 uart_send_xchar(tty, START_CHAR(tty));
676 if (mask & UPSTAT_AUTORTS)
677 uart_set_mctrl(port, TIOCM_RTS);
680 static void do_uart_get_info(struct tty_port *port,
681 struct serial_struct *retinfo)
683 struct uart_state *state = container_of(port, struct uart_state, port);
684 struct uart_port *uport = state->uart_port;
686 memset(retinfo, 0, sizeof(*retinfo));
688 retinfo->type = uport->type;
689 retinfo->line = uport->line;
690 retinfo->port = uport->iobase;
691 if (HIGH_BITS_OFFSET)
692 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
693 retinfo->irq = uport->irq;
694 retinfo->flags = uport->flags;
695 retinfo->xmit_fifo_size = uport->fifosize;
696 retinfo->baud_base = uport->uartclk / 16;
697 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
698 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
699 ASYNC_CLOSING_WAIT_NONE :
700 jiffies_to_msecs(port->closing_wait) / 10;
701 retinfo->custom_divisor = uport->custom_divisor;
702 retinfo->hub6 = uport->hub6;
703 retinfo->io_type = uport->iotype;
704 retinfo->iomem_reg_shift = uport->regshift;
705 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
708 static void uart_get_info(struct tty_port *port,
709 struct serial_struct *retinfo)
711 /* Ensure the state we copy is consistent and no hardware changes
713 mutex_lock(&port->mutex);
714 do_uart_get_info(port, retinfo);
715 mutex_unlock(&port->mutex);
718 static int uart_get_info_user(struct tty_port *port,
719 struct serial_struct __user *retinfo)
721 struct serial_struct tmp;
722 uart_get_info(port, &tmp);
724 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
729 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
730 struct uart_state *state,
731 struct serial_struct *new_info)
733 struct uart_port *uport = state->uart_port;
734 unsigned long new_port;
735 unsigned int change_irq, change_port, closing_wait;
736 unsigned int old_custom_divisor, close_delay;
737 upf_t old_flags, new_flags;
740 new_port = new_info->port;
741 if (HIGH_BITS_OFFSET)
742 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
744 new_info->irq = irq_canonicalize(new_info->irq);
745 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
746 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
747 ASYNC_CLOSING_WAIT_NONE :
748 msecs_to_jiffies(new_info->closing_wait * 10);
751 change_irq = !(uport->flags & UPF_FIXED_PORT)
752 && new_info->irq != uport->irq;
755 * Since changing the 'type' of the port changes its resource
756 * allocations, we should treat type changes the same as
759 change_port = !(uport->flags & UPF_FIXED_PORT)
760 && (new_port != uport->iobase ||
761 (unsigned long)new_info->iomem_base != uport->mapbase ||
762 new_info->hub6 != uport->hub6 ||
763 new_info->io_type != uport->iotype ||
764 new_info->iomem_reg_shift != uport->regshift ||
765 new_info->type != uport->type);
767 old_flags = uport->flags;
768 new_flags = new_info->flags;
769 old_custom_divisor = uport->custom_divisor;
771 if (!capable(CAP_SYS_ADMIN)) {
773 if (change_irq || change_port ||
774 (new_info->baud_base != uport->uartclk / 16) ||
775 (close_delay != port->close_delay) ||
776 (closing_wait != port->closing_wait) ||
777 (new_info->xmit_fifo_size &&
778 new_info->xmit_fifo_size != uport->fifosize) ||
779 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
781 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
782 (new_flags & UPF_USR_MASK));
783 uport->custom_divisor = new_info->custom_divisor;
788 * Ask the low level driver to verify the settings.
790 if (uport->ops->verify_port)
791 retval = uport->ops->verify_port(uport, new_info);
793 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
794 (new_info->baud_base < 9600))
800 if (change_port || change_irq) {
804 * Make sure that we are the sole user of this port.
806 if (tty_port_users(port) > 1)
810 * We need to shutdown the serial port at the old
811 * port/type/irq combination.
813 uart_shutdown(tty, state);
817 unsigned long old_iobase, old_mapbase;
818 unsigned int old_type, old_iotype, old_hub6, old_shift;
820 old_iobase = uport->iobase;
821 old_mapbase = uport->mapbase;
822 old_type = uport->type;
823 old_hub6 = uport->hub6;
824 old_iotype = uport->iotype;
825 old_shift = uport->regshift;
828 * Free and release old regions
830 if (old_type != PORT_UNKNOWN)
831 uport->ops->release_port(uport);
833 uport->iobase = new_port;
834 uport->type = new_info->type;
835 uport->hub6 = new_info->hub6;
836 uport->iotype = new_info->io_type;
837 uport->regshift = new_info->iomem_reg_shift;
838 uport->mapbase = (unsigned long)new_info->iomem_base;
841 * Claim and map the new regions
843 if (uport->type != PORT_UNKNOWN) {
844 retval = uport->ops->request_port(uport);
846 /* Always success - Jean II */
851 * If we fail to request resources for the
852 * new port, try to restore the old settings.
855 uport->iobase = old_iobase;
856 uport->type = old_type;
857 uport->hub6 = old_hub6;
858 uport->iotype = old_iotype;
859 uport->regshift = old_shift;
860 uport->mapbase = old_mapbase;
862 if (old_type != PORT_UNKNOWN) {
863 retval = uport->ops->request_port(uport);
865 * If we failed to restore the old settings,
869 uport->type = PORT_UNKNOWN;
877 /* Added to return the correct error -Ram Gupta */
883 uport->irq = new_info->irq;
884 if (!(uport->flags & UPF_FIXED_PORT))
885 uport->uartclk = new_info->baud_base * 16;
886 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
887 (new_flags & UPF_CHANGE_MASK);
888 uport->custom_divisor = new_info->custom_divisor;
889 port->close_delay = close_delay;
890 port->closing_wait = closing_wait;
891 if (new_info->xmit_fifo_size)
892 uport->fifosize = new_info->xmit_fifo_size;
893 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
897 if (uport->type == PORT_UNKNOWN)
899 if (port->flags & ASYNC_INITIALIZED) {
900 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
901 old_custom_divisor != uport->custom_divisor) {
903 * If they're setting up a custom divisor or speed,
904 * instead of clearing it, then bitch about it. No
905 * need to rate-limit; it's CAP_SYS_ADMIN only.
907 if (uport->flags & UPF_SPD_MASK) {
908 dev_notice(uport->dev,
909 "%s sets custom speed on %s. This is deprecated.\n",
911 tty_name(port->tty));
913 uart_change_speed(tty, state, NULL);
916 retval = uart_startup(tty, state, 1);
921 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
922 struct serial_struct __user *newinfo)
924 struct serial_struct new_serial;
925 struct tty_port *port = &state->port;
928 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
932 * This semaphore protects port->count. It is also
933 * very useful to prevent opens. Also, take the
934 * port configuration semaphore to make sure that a
935 * module insertion/removal doesn't change anything
938 mutex_lock(&port->mutex);
939 retval = uart_set_info(tty, port, state, &new_serial);
940 mutex_unlock(&port->mutex);
945 * uart_get_lsr_info - get line status register info
946 * @tty: tty associated with the UART
947 * @state: UART being queried
948 * @value: returned modem value
950 * Note: uart_ioctl protects us against hangups.
952 static int uart_get_lsr_info(struct tty_struct *tty,
953 struct uart_state *state, unsigned int __user *value)
955 struct uart_port *uport = state->uart_port;
958 result = uport->ops->tx_empty(uport);
961 * If we're about to load something into the transmit
962 * register, we'll pretend the transmitter isn't empty to
963 * avoid a race condition (depending on when the transmit
964 * interrupt happens).
967 ((uart_circ_chars_pending(&state->xmit) > 0) &&
968 !uart_tx_stopped(uport)))
969 result &= ~TIOCSER_TEMT;
971 return put_user(result, value);
974 static int uart_tiocmget(struct tty_struct *tty)
976 struct uart_state *state = tty->driver_data;
977 struct tty_port *port = &state->port;
978 struct uart_port *uport = state->uart_port;
981 mutex_lock(&port->mutex);
982 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
983 result = uport->mctrl;
984 spin_lock_irq(&uport->lock);
985 result |= uport->ops->get_mctrl(uport);
986 spin_unlock_irq(&uport->lock);
988 mutex_unlock(&port->mutex);
994 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
996 struct uart_state *state = tty->driver_data;
997 struct uart_port *uport = state->uart_port;
998 struct tty_port *port = &state->port;
1001 mutex_lock(&port->mutex);
1002 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1003 uart_update_mctrl(uport, set, clear);
1006 mutex_unlock(&port->mutex);
1010 static int uart_break_ctl(struct tty_struct *tty, int break_state)
1012 struct uart_state *state = tty->driver_data;
1013 struct tty_port *port = &state->port;
1014 struct uart_port *uport = state->uart_port;
1016 mutex_lock(&port->mutex);
1018 if (uport->type != PORT_UNKNOWN)
1019 uport->ops->break_ctl(uport, break_state);
1021 mutex_unlock(&port->mutex);
1025 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1027 struct uart_port *uport = state->uart_port;
1028 struct tty_port *port = &state->port;
1031 if (!capable(CAP_SYS_ADMIN))
1035 * Take the per-port semaphore. This prevents count from
1036 * changing, and hence any extra opens of the port while
1037 * we're auto-configuring.
1039 if (mutex_lock_interruptible(&port->mutex))
1040 return -ERESTARTSYS;
1043 if (tty_port_users(port) == 1) {
1044 uart_shutdown(tty, state);
1047 * If we already have a port type configured,
1048 * we must release its resources.
1050 if (uport->type != PORT_UNKNOWN)
1051 uport->ops->release_port(uport);
1053 flags = UART_CONFIG_TYPE;
1054 if (uport->flags & UPF_AUTO_IRQ)
1055 flags |= UART_CONFIG_IRQ;
1058 * This will claim the ports resources if
1061 uport->ops->config_port(uport, flags);
1063 ret = uart_startup(tty, state, 1);
1065 mutex_unlock(&port->mutex);
1069 static void uart_enable_ms(struct uart_port *uport)
1072 * Force modem status interrupts on
1074 if (uport->ops->enable_ms)
1075 uport->ops->enable_ms(uport);
1079 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1080 * - mask passed in arg for lines of interest
1081 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1082 * Caller should use TIOCGICOUNT to see which one it was
1084 * FIXME: This wants extracting into a common all driver implementation
1085 * of TIOCMWAIT using tty_port.
1088 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1090 struct uart_port *uport = state->uart_port;
1091 struct tty_port *port = &state->port;
1092 DECLARE_WAITQUEUE(wait, current);
1093 struct uart_icount cprev, cnow;
1097 * note the counters on entry
1099 spin_lock_irq(&uport->lock);
1100 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1101 uart_enable_ms(uport);
1102 spin_unlock_irq(&uport->lock);
1104 add_wait_queue(&port->delta_msr_wait, &wait);
1106 spin_lock_irq(&uport->lock);
1107 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1108 spin_unlock_irq(&uport->lock);
1110 set_current_state(TASK_INTERRUPTIBLE);
1112 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1113 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1114 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1115 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1122 /* see if a signal did it */
1123 if (signal_pending(current)) {
1130 __set_current_state(TASK_RUNNING);
1131 remove_wait_queue(&port->delta_msr_wait, &wait);
1137 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1138 * Return: write counters to the user passed counter struct
1139 * NB: both 1->0 and 0->1 transitions are counted except for
1140 * RI where only 0->1 is counted.
1142 static int uart_get_icount(struct tty_struct *tty,
1143 struct serial_icounter_struct *icount)
1145 struct uart_state *state = tty->driver_data;
1146 struct uart_icount cnow;
1147 struct uart_port *uport = state->uart_port;
1149 spin_lock_irq(&uport->lock);
1150 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1151 spin_unlock_irq(&uport->lock);
1153 icount->cts = cnow.cts;
1154 icount->dsr = cnow.dsr;
1155 icount->rng = cnow.rng;
1156 icount->dcd = cnow.dcd;
1157 icount->rx = cnow.rx;
1158 icount->tx = cnow.tx;
1159 icount->frame = cnow.frame;
1160 icount->overrun = cnow.overrun;
1161 icount->parity = cnow.parity;
1162 icount->brk = cnow.brk;
1163 icount->buf_overrun = cnow.buf_overrun;
1168 static int uart_get_rs485_config(struct uart_port *port,
1169 struct serial_rs485 __user *rs485)
1171 unsigned long flags;
1172 struct serial_rs485 aux;
1174 spin_lock_irqsave(&port->lock, flags);
1176 spin_unlock_irqrestore(&port->lock, flags);
1178 if (copy_to_user(rs485, &aux, sizeof(aux)))
1184 static int uart_set_rs485_config(struct uart_port *port,
1185 struct serial_rs485 __user *rs485_user)
1187 struct serial_rs485 rs485;
1189 unsigned long flags;
1191 if (!port->rs485_config)
1192 return -ENOIOCTLCMD;
1194 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1197 spin_lock_irqsave(&port->lock, flags);
1198 ret = port->rs485_config(port, &rs485);
1199 spin_unlock_irqrestore(&port->lock, flags);
1203 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1210 * Called via sys_ioctl. We can use spin_lock_irq() here.
1213 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1216 struct uart_state *state = tty->driver_data;
1217 struct tty_port *port = &state->port;
1218 void __user *uarg = (void __user *)arg;
1219 int ret = -ENOIOCTLCMD;
1223 * These ioctls don't rely on the hardware to be present.
1227 ret = uart_get_info_user(port, uarg);
1231 down_write(&tty->termios_rwsem);
1232 ret = uart_set_info_user(tty, state, uarg);
1233 up_write(&tty->termios_rwsem);
1237 down_write(&tty->termios_rwsem);
1238 ret = uart_do_autoconfig(tty, state);
1239 up_write(&tty->termios_rwsem);
1242 case TIOCSERGWILD: /* obsolete */
1243 case TIOCSERSWILD: /* obsolete */
1248 if (ret != -ENOIOCTLCMD)
1251 if (tty->flags & (1 << TTY_IO_ERROR)) {
1257 * The following should only be used when hardware is present.
1261 ret = uart_wait_modem_status(state, arg);
1265 if (ret != -ENOIOCTLCMD)
1268 mutex_lock(&port->mutex);
1270 if (tty->flags & (1 << TTY_IO_ERROR)) {
1276 * All these rely on hardware being present and need to be
1277 * protected against the tty being hung up.
1281 case TIOCSERGETLSR: /* Get line status register */
1282 ret = uart_get_lsr_info(tty, state, uarg);
1286 ret = uart_get_rs485_config(state->uart_port, uarg);
1290 ret = uart_set_rs485_config(state->uart_port, uarg);
1293 struct uart_port *uport = state->uart_port;
1294 if (uport->ops->ioctl)
1295 ret = uport->ops->ioctl(uport, cmd, arg);
1300 mutex_unlock(&port->mutex);
1305 static void uart_set_ldisc(struct tty_struct *tty)
1307 struct uart_state *state = tty->driver_data;
1308 struct uart_port *uport = state->uart_port;
1310 if (uport->ops->set_ldisc) {
1311 mutex_lock(&state->port.mutex);
1312 uport->ops->set_ldisc(uport, &tty->termios);
1313 mutex_unlock(&state->port.mutex);
1317 static void uart_set_termios(struct tty_struct *tty,
1318 struct ktermios *old_termios)
1320 struct uart_state *state = tty->driver_data;
1321 struct uart_port *uport = state->uart_port;
1322 unsigned int cflag = tty->termios.c_cflag;
1323 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1324 bool sw_changed = false;
1327 * Drivers doing software flow control also need to know
1328 * about changes to these input settings.
1330 if (uport->flags & UPF_SOFT_FLOW) {
1331 iflag_mask |= IXANY|IXON|IXOFF;
1333 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1334 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1338 * These are the bits that are used to setup various
1339 * flags in the low level driver. We can ignore the Bfoo
1340 * bits in c_cflag; c_[io]speed will always be set
1341 * appropriately by set_termios() in tty_ioctl.c
1343 if ((cflag ^ old_termios->c_cflag) == 0 &&
1344 tty->termios.c_ospeed == old_termios->c_ospeed &&
1345 tty->termios.c_ispeed == old_termios->c_ispeed &&
1346 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1351 mutex_lock(&state->port.mutex);
1352 uart_change_speed(tty, state, old_termios);
1353 mutex_unlock(&state->port.mutex);
1354 /* reload cflag from termios; port driver may have overriden flags */
1355 cflag = tty->termios.c_cflag;
1357 /* Handle transition to B0 status */
1358 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1359 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1360 /* Handle transition away from B0 status */
1361 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1362 unsigned int mask = TIOCM_DTR;
1363 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1365 uart_set_mctrl(uport, mask);
1370 * Calls to uart_close() are serialised via the tty_lock in
1371 * drivers/tty/tty_io.c:tty_release()
1372 * drivers/tty/tty_io.c:do_tty_hangup()
1373 * This runs from a workqueue and can sleep for a _short_ time only.
1375 static void uart_close(struct tty_struct *tty, struct file *filp)
1377 struct uart_state *state = tty->driver_data;
1378 struct tty_port *port;
1379 struct uart_port *uport;
1380 unsigned long flags;
1383 struct uart_driver *drv = tty->driver->driver_state;
1385 state = drv->state + tty->index;
1386 port = &state->port;
1387 spin_lock_irq(&port->lock);
1389 spin_unlock_irq(&port->lock);
1393 uport = state->uart_port;
1394 port = &state->port;
1396 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1398 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1402 * At this point, we stop accepting input. To do this, we
1403 * disable the receive line status interrupts.
1405 if (port->flags & ASYNC_INITIALIZED) {
1406 unsigned long flags;
1407 spin_lock_irqsave(&uport->lock, flags);
1408 uport->ops->stop_rx(uport);
1409 spin_unlock_irqrestore(&uport->lock, flags);
1411 * Before we drop DTR, make sure the UART transmitter
1412 * has completely drained; this is especially
1413 * important if there is a transmit FIFO!
1415 uart_wait_until_sent(tty, uport->timeout);
1418 mutex_lock(&port->mutex);
1419 uart_shutdown(tty, state);
1420 tty_port_tty_set(port, NULL);
1422 spin_lock_irqsave(&port->lock, flags);
1424 if (port->blocked_open) {
1425 spin_unlock_irqrestore(&port->lock, flags);
1426 if (port->close_delay)
1427 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1428 spin_lock_irqsave(&port->lock, flags);
1429 } else if (!uart_console(uport)) {
1430 spin_unlock_irqrestore(&port->lock, flags);
1431 uart_change_pm(state, UART_PM_STATE_OFF);
1432 spin_lock_irqsave(&port->lock, flags);
1436 * Wake up anyone trying to open this port.
1438 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1439 clear_bit(ASYNCB_CLOSING, &port->flags);
1440 spin_unlock_irqrestore(&port->lock, flags);
1441 wake_up_interruptible(&port->open_wait);
1442 wake_up_interruptible(&port->close_wait);
1444 mutex_unlock(&port->mutex);
1446 tty_ldisc_flush(tty);
1449 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1451 struct uart_state *state = tty->driver_data;
1452 struct uart_port *port = state->uart_port;
1453 unsigned long char_time, expire;
1455 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1459 * Set the check interval to be 1/5 of the estimated time to
1460 * send a single character, and make it at least 1. The check
1461 * interval should also be less than the timeout.
1463 * Note: we have to use pretty tight timings here to satisfy
1466 char_time = (port->timeout - HZ/50) / port->fifosize;
1467 char_time = char_time / 5;
1470 if (timeout && timeout < char_time)
1471 char_time = timeout;
1474 * If the transmitter hasn't cleared in twice the approximate
1475 * amount of time to send the entire FIFO, it probably won't
1476 * ever clear. This assumes the UART isn't doing flow
1477 * control, which is currently the case. Hence, if it ever
1478 * takes longer than port->timeout, this is probably due to a
1479 * UART bug of some kind. So, we clamp the timeout parameter at
1482 if (timeout == 0 || timeout > 2 * port->timeout)
1483 timeout = 2 * port->timeout;
1485 expire = jiffies + timeout;
1487 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1488 port->line, jiffies, expire);
1491 * Check whether the transmitter is empty every 'char_time'.
1492 * 'timeout' / 'expire' give us the maximum amount of time
1495 while (!port->ops->tx_empty(port)) {
1496 msleep_interruptible(jiffies_to_msecs(char_time));
1497 if (signal_pending(current))
1499 if (time_after(jiffies, expire))
1505 * Calls to uart_hangup() are serialised by the tty_lock in
1506 * drivers/tty/tty_io.c:do_tty_hangup()
1507 * This runs from a workqueue and can sleep for a _short_ time only.
1509 static void uart_hangup(struct tty_struct *tty)
1511 struct uart_state *state = tty->driver_data;
1512 struct tty_port *port = &state->port;
1513 unsigned long flags;
1515 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1517 mutex_lock(&port->mutex);
1518 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1519 uart_flush_buffer(tty);
1520 uart_shutdown(tty, state);
1521 spin_lock_irqsave(&port->lock, flags);
1523 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1524 spin_unlock_irqrestore(&port->lock, flags);
1525 tty_port_tty_set(port, NULL);
1526 if (!uart_console(state->uart_port))
1527 uart_change_pm(state, UART_PM_STATE_OFF);
1528 wake_up_interruptible(&port->open_wait);
1529 wake_up_interruptible(&port->delta_msr_wait);
1531 mutex_unlock(&port->mutex);
1534 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1539 static void uart_port_shutdown(struct tty_port *port)
1541 struct uart_state *state = container_of(port, struct uart_state, port);
1542 struct uart_port *uport = state->uart_port;
1545 * clear delta_msr_wait queue to avoid mem leaks: we may free
1546 * the irq here so the queue might never be woken up. Note
1547 * that we won't end up waiting on delta_msr_wait again since
1548 * any outstanding file descriptors should be pointing at
1549 * hung_up_tty_fops now.
1551 wake_up_interruptible(&port->delta_msr_wait);
1554 * Free the IRQ and disable the port.
1556 uport->ops->shutdown(uport);
1559 * Ensure that the IRQ handler isn't running on another CPU.
1561 synchronize_irq(uport->irq);
1564 static int uart_carrier_raised(struct tty_port *port)
1566 struct uart_state *state = container_of(port, struct uart_state, port);
1567 struct uart_port *uport = state->uart_port;
1569 spin_lock_irq(&uport->lock);
1570 uart_enable_ms(uport);
1571 mctrl = uport->ops->get_mctrl(uport);
1572 spin_unlock_irq(&uport->lock);
1573 if (mctrl & TIOCM_CAR)
1578 static void uart_dtr_rts(struct tty_port *port, int onoff)
1580 struct uart_state *state = container_of(port, struct uart_state, port);
1581 struct uart_port *uport = state->uart_port;
1584 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1586 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1590 * Calls to uart_open are serialised by the tty_lock in
1591 * drivers/tty/tty_io.c:tty_open()
1592 * Note that if this fails, then uart_close() _will_ be called.
1594 * In time, we want to scrap the "opening nonpresent ports"
1595 * behaviour and implement an alternative way for setserial
1596 * to set base addresses/ports/types. This will allow us to
1597 * get rid of a certain amount of extra tests.
1599 static int uart_open(struct tty_struct *tty, struct file *filp)
1601 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1602 int retval, line = tty->index;
1603 struct uart_state *state = drv->state + line;
1604 struct tty_port *port = &state->port;
1606 pr_debug("uart_open(%d) called\n", line);
1608 spin_lock_irq(&port->lock);
1610 spin_unlock_irq(&port->lock);
1613 * We take the semaphore here to guarantee that we won't be re-entered
1614 * while allocating the state structure, or while we request any IRQs
1615 * that the driver may need. This also has the nice side-effect that
1616 * it delays the action of uart_hangup, so we can guarantee that
1617 * state->port.tty will always contain something reasonable.
1619 if (mutex_lock_interruptible(&port->mutex)) {
1620 retval = -ERESTARTSYS;
1624 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1629 tty->driver_data = state;
1630 state->uart_port->state = state;
1631 state->port.low_latency =
1632 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1633 tty_port_tty_set(port, tty);
1636 * Start up the serial port.
1638 retval = uart_startup(tty, state, 0);
1641 * If we succeeded, wait until the port is ready.
1643 mutex_unlock(&port->mutex);
1645 retval = tty_port_block_til_ready(port, tty, filp);
1650 mutex_unlock(&port->mutex);
1654 static const char *uart_type(struct uart_port *port)
1656 const char *str = NULL;
1658 if (port->ops->type)
1659 str = port->ops->type(port);
1667 #ifdef CONFIG_PROC_FS
1669 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1671 struct uart_state *state = drv->state + i;
1672 struct tty_port *port = &state->port;
1673 enum uart_pm_state pm_state;
1674 struct uart_port *uport = state->uart_port;
1676 unsigned int status;
1682 mmio = uport->iotype >= UPIO_MEM;
1683 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1684 uport->line, uart_type(uport),
1685 mmio ? "mmio:0x" : "port:",
1686 mmio ? (unsigned long long)uport->mapbase
1687 : (unsigned long long)uport->iobase,
1690 if (uport->type == PORT_UNKNOWN) {
1695 if (capable(CAP_SYS_ADMIN)) {
1696 mutex_lock(&port->mutex);
1697 pm_state = state->pm_state;
1698 if (pm_state != UART_PM_STATE_ON)
1699 uart_change_pm(state, UART_PM_STATE_ON);
1700 spin_lock_irq(&uport->lock);
1701 status = uport->ops->get_mctrl(uport);
1702 spin_unlock_irq(&uport->lock);
1703 if (pm_state != UART_PM_STATE_ON)
1704 uart_change_pm(state, pm_state);
1705 mutex_unlock(&port->mutex);
1707 seq_printf(m, " tx:%d rx:%d",
1708 uport->icount.tx, uport->icount.rx);
1709 if (uport->icount.frame)
1710 seq_printf(m, " fe:%d",
1711 uport->icount.frame);
1712 if (uport->icount.parity)
1713 seq_printf(m, " pe:%d",
1714 uport->icount.parity);
1715 if (uport->icount.brk)
1716 seq_printf(m, " brk:%d",
1718 if (uport->icount.overrun)
1719 seq_printf(m, " oe:%d",
1720 uport->icount.overrun);
1722 #define INFOBIT(bit, str) \
1723 if (uport->mctrl & (bit)) \
1724 strncat(stat_buf, (str), sizeof(stat_buf) - \
1725 strlen(stat_buf) - 2)
1726 #define STATBIT(bit, str) \
1727 if (status & (bit)) \
1728 strncat(stat_buf, (str), sizeof(stat_buf) - \
1729 strlen(stat_buf) - 2)
1733 INFOBIT(TIOCM_RTS, "|RTS");
1734 STATBIT(TIOCM_CTS, "|CTS");
1735 INFOBIT(TIOCM_DTR, "|DTR");
1736 STATBIT(TIOCM_DSR, "|DSR");
1737 STATBIT(TIOCM_CAR, "|CD");
1738 STATBIT(TIOCM_RNG, "|RI");
1742 seq_puts(m, stat_buf);
1749 static int uart_proc_show(struct seq_file *m, void *v)
1751 struct tty_driver *ttydrv = m->private;
1752 struct uart_driver *drv = ttydrv->driver_state;
1755 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1757 for (i = 0; i < drv->nr; i++)
1758 uart_line_info(m, drv, i);
1762 static int uart_proc_open(struct inode *inode, struct file *file)
1764 return single_open(file, uart_proc_show, PDE_DATA(inode));
1767 static const struct file_operations uart_proc_fops = {
1768 .owner = THIS_MODULE,
1769 .open = uart_proc_open,
1771 .llseek = seq_lseek,
1772 .release = single_release,
1776 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1778 * uart_console_write - write a console message to a serial port
1779 * @port: the port to write the message
1780 * @s: array of characters
1781 * @count: number of characters in string to write
1782 * @putchar: function to write character to port
1784 void uart_console_write(struct uart_port *port, const char *s,
1786 void (*putchar)(struct uart_port *, int))
1790 for (i = 0; i < count; i++, s++) {
1792 putchar(port, '\r');
1796 EXPORT_SYMBOL_GPL(uart_console_write);
1799 * Check whether an invalid uart number has been specified, and
1800 * if so, search for the first available port that does have
1803 struct uart_port * __init
1804 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1806 int idx = co->index;
1808 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1809 ports[idx].membase == NULL))
1810 for (idx = 0; idx < nr; idx++)
1811 if (ports[idx].iobase != 0 ||
1812 ports[idx].membase != NULL)
1821 * uart_parse_earlycon - Parse earlycon options
1822 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1823 * @iotype: ptr for decoded iotype (out)
1824 * @addr: ptr for decoded mapbase/iobase (out)
1825 * @options: ptr for <options> field; NULL if not present (out)
1827 * Decodes earlycon kernel command line parameters of the form
1828 * earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>
1829 * console=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>
1832 * earlycon=<name>,0x<addr>,<options>
1833 * console=<name>,0x<addr>,<options>
1834 * is also accepted; the returned @iotype will be UPIO_MEM.
1836 * Returns 0 on success or -EINVAL on failure
1838 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1841 if (strncmp(p, "mmio,", 5) == 0) {
1844 } else if (strncmp(p, "mmio32,", 7) == 0) {
1845 *iotype = UPIO_MEM32;
1847 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1848 *iotype = UPIO_MEM32BE;
1850 } else if (strncmp(p, "io,", 3) == 0) {
1851 *iotype = UPIO_PORT;
1853 } else if (strncmp(p, "0x", 2) == 0) {
1859 *addr = simple_strtoul(p, NULL, 0);
1867 EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1870 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1871 * @options: pointer to option string
1872 * @baud: pointer to an 'int' variable for the baud rate.
1873 * @parity: pointer to an 'int' variable for the parity.
1874 * @bits: pointer to an 'int' variable for the number of data bits.
1875 * @flow: pointer to an 'int' variable for the flow control character.
1877 * uart_parse_options decodes a string containing the serial console
1878 * options. The format of the string is <baud><parity><bits><flow>,
1882 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1886 *baud = simple_strtoul(s, NULL, 10);
1887 while (*s >= '0' && *s <= '9')
1896 EXPORT_SYMBOL_GPL(uart_parse_options);
1903 static const struct baud_rates baud_rates[] = {
1904 { 921600, B921600 },
1905 { 460800, B460800 },
1906 { 230400, B230400 },
1907 { 115200, B115200 },
1919 * uart_set_options - setup the serial console parameters
1920 * @port: pointer to the serial ports uart_port structure
1921 * @co: console pointer
1923 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1924 * @bits: number of data bits
1925 * @flow: flow control character - 'r' (rts)
1928 uart_set_options(struct uart_port *port, struct console *co,
1929 int baud, int parity, int bits, int flow)
1931 struct ktermios termios;
1932 static struct ktermios dummy;
1936 * Ensure that the serial console lock is initialised
1938 * If this port is a console, then the spinlock is already
1941 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1942 spin_lock_init(&port->lock);
1943 lockdep_set_class(&port->lock, &port_lock_key);
1946 memset(&termios, 0, sizeof(struct ktermios));
1948 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1951 * Construct a cflag setting.
1953 for (i = 0; baud_rates[i].rate; i++)
1954 if (baud_rates[i].rate <= baud)
1957 termios.c_cflag |= baud_rates[i].cflag;
1960 termios.c_cflag |= CS7;
1962 termios.c_cflag |= CS8;
1966 termios.c_cflag |= PARODD;
1969 termios.c_cflag |= PARENB;
1974 termios.c_cflag |= CRTSCTS;
1977 * some uarts on other side don't support no flow control.
1978 * So we set * DTR in host uart to make them happy
1980 port->mctrl |= TIOCM_DTR;
1982 port->ops->set_termios(port, &termios, &dummy);
1984 * Allow the setting of the UART parameters with a NULL console
1988 co->cflag = termios.c_cflag;
1992 EXPORT_SYMBOL_GPL(uart_set_options);
1993 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1996 * uart_change_pm - set power state of the port
1998 * @state: port descriptor
1999 * @pm_state: new state
2001 * Locking: port->mutex has to be held
2003 static void uart_change_pm(struct uart_state *state,
2004 enum uart_pm_state pm_state)
2006 struct uart_port *port = state->uart_port;
2008 if (state->pm_state != pm_state) {
2010 port->ops->pm(port, pm_state, state->pm_state);
2011 state->pm_state = pm_state;
2016 struct uart_port *port;
2017 struct uart_driver *driver;
2020 static int serial_match_port(struct device *dev, void *data)
2022 struct uart_match *match = data;
2023 struct tty_driver *tty_drv = match->driver->tty_driver;
2024 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2027 return dev->devt == devt; /* Actually, only one tty per port */
2030 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2032 struct uart_state *state = drv->state + uport->line;
2033 struct tty_port *port = &state->port;
2034 struct device *tty_dev;
2035 struct uart_match match = {uport, drv};
2037 mutex_lock(&port->mutex);
2039 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2040 if (device_may_wakeup(tty_dev)) {
2041 if (!enable_irq_wake(uport->irq))
2042 uport->irq_wake = 1;
2043 put_device(tty_dev);
2044 mutex_unlock(&port->mutex);
2047 put_device(tty_dev);
2049 /* Nothing to do if the console is not suspending */
2050 if (!console_suspend_enabled && uart_console(uport))
2053 uport->suspended = 1;
2055 if (port->flags & ASYNC_INITIALIZED) {
2056 const struct uart_ops *ops = uport->ops;
2059 set_bit(ASYNCB_SUSPENDED, &port->flags);
2060 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2062 spin_lock_irq(&uport->lock);
2063 ops->stop_tx(uport);
2064 ops->set_mctrl(uport, 0);
2065 ops->stop_rx(uport);
2066 spin_unlock_irq(&uport->lock);
2069 * Wait for the transmitter to empty.
2071 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2074 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2076 drv->tty_driver->name_base + uport->line);
2078 ops->shutdown(uport);
2082 * Disable the console device before suspending.
2084 if (uart_console(uport))
2085 console_stop(uport->cons);
2087 uart_change_pm(state, UART_PM_STATE_OFF);
2089 mutex_unlock(&port->mutex);
2094 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2096 struct uart_state *state = drv->state + uport->line;
2097 struct tty_port *port = &state->port;
2098 struct device *tty_dev;
2099 struct uart_match match = {uport, drv};
2100 struct ktermios termios;
2102 mutex_lock(&port->mutex);
2104 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2105 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2106 if (uport->irq_wake) {
2107 disable_irq_wake(uport->irq);
2108 uport->irq_wake = 0;
2110 put_device(tty_dev);
2111 mutex_unlock(&port->mutex);
2114 put_device(tty_dev);
2115 uport->suspended = 0;
2118 * Re-enable the console device after suspending.
2120 if (uart_console(uport)) {
2122 * First try to use the console cflag setting.
2124 memset(&termios, 0, sizeof(struct ktermios));
2125 termios.c_cflag = uport->cons->cflag;
2128 * If that's unset, use the tty termios setting.
2130 if (port->tty && termios.c_cflag == 0)
2131 termios = port->tty->termios;
2133 if (console_suspend_enabled)
2134 uart_change_pm(state, UART_PM_STATE_ON);
2135 uport->ops->set_termios(uport, &termios, NULL);
2136 if (console_suspend_enabled)
2137 console_start(uport->cons);
2140 if (port->flags & ASYNC_SUSPENDED) {
2141 const struct uart_ops *ops = uport->ops;
2144 uart_change_pm(state, UART_PM_STATE_ON);
2145 spin_lock_irq(&uport->lock);
2146 ops->set_mctrl(uport, 0);
2147 spin_unlock_irq(&uport->lock);
2148 if (console_suspend_enabled || !uart_console(uport)) {
2149 /* Protected by port mutex for now */
2150 struct tty_struct *tty = port->tty;
2151 ret = ops->startup(uport);
2154 uart_change_speed(tty, state, NULL);
2155 spin_lock_irq(&uport->lock);
2156 ops->set_mctrl(uport, uport->mctrl);
2157 ops->start_tx(uport);
2158 spin_unlock_irq(&uport->lock);
2159 set_bit(ASYNCB_INITIALIZED, &port->flags);
2162 * Failed to resume - maybe hardware went away?
2163 * Clear the "initialized" flag so we won't try
2164 * to call the low level drivers shutdown method.
2166 uart_shutdown(tty, state);
2170 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2173 mutex_unlock(&port->mutex);
2179 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2183 switch (port->iotype) {
2185 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2188 snprintf(address, sizeof(address),
2189 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2196 snprintf(address, sizeof(address),
2197 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2200 strlcpy(address, "*unknown*", sizeof(address));
2204 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2205 port->dev ? dev_name(port->dev) : "",
2206 port->dev ? ": " : "",
2208 drv->tty_driver->name_base + port->line,
2209 address, port->irq, port->uartclk / 16, uart_type(port));
2213 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2214 struct uart_port *port)
2219 * If there isn't a port here, don't do anything further.
2221 if (!port->iobase && !port->mapbase && !port->membase)
2225 * Now do the auto configuration stuff. Note that config_port
2226 * is expected to claim the resources and map the port for us.
2229 if (port->flags & UPF_AUTO_IRQ)
2230 flags |= UART_CONFIG_IRQ;
2231 if (port->flags & UPF_BOOT_AUTOCONF) {
2232 if (!(port->flags & UPF_FIXED_TYPE)) {
2233 port->type = PORT_UNKNOWN;
2234 flags |= UART_CONFIG_TYPE;
2236 port->ops->config_port(port, flags);
2239 if (port->type != PORT_UNKNOWN) {
2240 unsigned long flags;
2242 uart_report_port(drv, port);
2244 /* Power up port for set_mctrl() */
2245 uart_change_pm(state, UART_PM_STATE_ON);
2248 * Ensure that the modem control lines are de-activated.
2249 * keep the DTR setting that is set in uart_set_options()
2250 * We probably don't need a spinlock around this, but
2252 spin_lock_irqsave(&port->lock, flags);
2253 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2254 spin_unlock_irqrestore(&port->lock, flags);
2257 * If this driver supports console, and it hasn't been
2258 * successfully registered yet, try to re-register it.
2259 * It may be that the port was not available.
2261 if (port->cons && !(port->cons->flags & CON_ENABLED))
2262 register_console(port->cons);
2265 * Power down all ports by default, except the
2266 * console if we have one.
2268 if (!uart_console(port))
2269 uart_change_pm(state, UART_PM_STATE_OFF);
2273 #ifdef CONFIG_CONSOLE_POLL
2275 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2277 struct uart_driver *drv = driver->driver_state;
2278 struct uart_state *state = drv->state + line;
2279 struct uart_port *port;
2286 if (!state || !state->uart_port)
2289 port = state->uart_port;
2290 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2293 if (port->ops->poll_init) {
2294 struct tty_port *tport = &state->port;
2297 mutex_lock(&tport->mutex);
2299 * We don't set ASYNCB_INITIALIZED as we only initialized the
2300 * hw, e.g. state->xmit is still uninitialized.
2302 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2303 ret = port->ops->poll_init(port);
2304 mutex_unlock(&tport->mutex);
2310 uart_parse_options(options, &baud, &parity, &bits, &flow);
2311 return uart_set_options(port, NULL, baud, parity, bits, flow);
2317 static int uart_poll_get_char(struct tty_driver *driver, int line)
2319 struct uart_driver *drv = driver->driver_state;
2320 struct uart_state *state = drv->state + line;
2321 struct uart_port *port;
2323 if (!state || !state->uart_port)
2326 port = state->uart_port;
2327 return port->ops->poll_get_char(port);
2330 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2332 struct uart_driver *drv = driver->driver_state;
2333 struct uart_state *state = drv->state + line;
2334 struct uart_port *port;
2336 if (!state || !state->uart_port)
2339 port = state->uart_port;
2342 port->ops->poll_put_char(port, '\r');
2343 port->ops->poll_put_char(port, ch);
2347 static const struct tty_operations uart_ops = {
2349 .close = uart_close,
2350 .write = uart_write,
2351 .put_char = uart_put_char,
2352 .flush_chars = uart_flush_chars,
2353 .write_room = uart_write_room,
2354 .chars_in_buffer= uart_chars_in_buffer,
2355 .flush_buffer = uart_flush_buffer,
2356 .ioctl = uart_ioctl,
2357 .throttle = uart_throttle,
2358 .unthrottle = uart_unthrottle,
2359 .send_xchar = uart_send_xchar,
2360 .set_termios = uart_set_termios,
2361 .set_ldisc = uart_set_ldisc,
2363 .start = uart_start,
2364 .hangup = uart_hangup,
2365 .break_ctl = uart_break_ctl,
2366 .wait_until_sent= uart_wait_until_sent,
2367 #ifdef CONFIG_PROC_FS
2368 .proc_fops = &uart_proc_fops,
2370 .tiocmget = uart_tiocmget,
2371 .tiocmset = uart_tiocmset,
2372 .get_icount = uart_get_icount,
2373 #ifdef CONFIG_CONSOLE_POLL
2374 .poll_init = uart_poll_init,
2375 .poll_get_char = uart_poll_get_char,
2376 .poll_put_char = uart_poll_put_char,
2380 static const struct tty_port_operations uart_port_ops = {
2381 .activate = uart_port_activate,
2382 .shutdown = uart_port_shutdown,
2383 .carrier_raised = uart_carrier_raised,
2384 .dtr_rts = uart_dtr_rts,
2388 * uart_register_driver - register a driver with the uart core layer
2389 * @drv: low level driver structure
2391 * Register a uart driver with the core driver. We in turn register
2392 * with the tty layer, and initialise the core driver per-port state.
2394 * We have a proc file in /proc/tty/driver which is named after the
2397 * drv->port should be NULL, and the per-port structures should be
2398 * registered using uart_add_one_port after this call has succeeded.
2400 int uart_register_driver(struct uart_driver *drv)
2402 struct tty_driver *normal;
2408 * Maybe we should be using a slab cache for this, especially if
2409 * we have a large number of ports to handle.
2411 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2415 normal = alloc_tty_driver(drv->nr);
2419 drv->tty_driver = normal;
2421 normal->driver_name = drv->driver_name;
2422 normal->name = drv->dev_name;
2423 normal->major = drv->major;
2424 normal->minor_start = drv->minor;
2425 normal->type = TTY_DRIVER_TYPE_SERIAL;
2426 normal->subtype = SERIAL_TYPE_NORMAL;
2427 normal->init_termios = tty_std_termios;
2428 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2429 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2430 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2431 normal->driver_state = drv;
2432 tty_set_operations(normal, &uart_ops);
2435 * Initialise the UART state(s).
2437 for (i = 0; i < drv->nr; i++) {
2438 struct uart_state *state = drv->state + i;
2439 struct tty_port *port = &state->port;
2441 tty_port_init(port);
2442 port->ops = &uart_port_ops;
2445 retval = tty_register_driver(normal);
2449 for (i = 0; i < drv->nr; i++)
2450 tty_port_destroy(&drv->state[i].port);
2451 put_tty_driver(normal);
2459 * uart_unregister_driver - remove a driver from the uart core layer
2460 * @drv: low level driver structure
2462 * Remove all references to a driver from the core driver. The low
2463 * level driver must have removed all its ports via the
2464 * uart_remove_one_port() if it registered them with uart_add_one_port().
2465 * (ie, drv->port == NULL)
2467 void uart_unregister_driver(struct uart_driver *drv)
2469 struct tty_driver *p = drv->tty_driver;
2472 tty_unregister_driver(p);
2474 for (i = 0; i < drv->nr; i++)
2475 tty_port_destroy(&drv->state[i].port);
2478 drv->tty_driver = NULL;
2481 struct tty_driver *uart_console_device(struct console *co, int *index)
2483 struct uart_driver *p = co->data;
2485 return p->tty_driver;
2488 static ssize_t uart_get_attr_uartclk(struct device *dev,
2489 struct device_attribute *attr, char *buf)
2491 struct serial_struct tmp;
2492 struct tty_port *port = dev_get_drvdata(dev);
2494 uart_get_info(port, &tmp);
2495 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2498 static ssize_t uart_get_attr_type(struct device *dev,
2499 struct device_attribute *attr, char *buf)
2501 struct serial_struct tmp;
2502 struct tty_port *port = dev_get_drvdata(dev);
2504 uart_get_info(port, &tmp);
2505 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2507 static ssize_t uart_get_attr_line(struct device *dev,
2508 struct device_attribute *attr, char *buf)
2510 struct serial_struct tmp;
2511 struct tty_port *port = dev_get_drvdata(dev);
2513 uart_get_info(port, &tmp);
2514 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2517 static ssize_t uart_get_attr_port(struct device *dev,
2518 struct device_attribute *attr, char *buf)
2520 struct serial_struct tmp;
2521 struct tty_port *port = dev_get_drvdata(dev);
2522 unsigned long ioaddr;
2524 uart_get_info(port, &tmp);
2526 if (HIGH_BITS_OFFSET)
2527 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2528 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2531 static ssize_t uart_get_attr_irq(struct device *dev,
2532 struct device_attribute *attr, char *buf)
2534 struct serial_struct tmp;
2535 struct tty_port *port = dev_get_drvdata(dev);
2537 uart_get_info(port, &tmp);
2538 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2541 static ssize_t uart_get_attr_flags(struct device *dev,
2542 struct device_attribute *attr, char *buf)
2544 struct serial_struct tmp;
2545 struct tty_port *port = dev_get_drvdata(dev);
2547 uart_get_info(port, &tmp);
2548 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2551 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2552 struct device_attribute *attr, char *buf)
2554 struct serial_struct tmp;
2555 struct tty_port *port = dev_get_drvdata(dev);
2557 uart_get_info(port, &tmp);
2558 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2562 static ssize_t uart_get_attr_close_delay(struct device *dev,
2563 struct device_attribute *attr, char *buf)
2565 struct serial_struct tmp;
2566 struct tty_port *port = dev_get_drvdata(dev);
2568 uart_get_info(port, &tmp);
2569 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2573 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2574 struct device_attribute *attr, char *buf)
2576 struct serial_struct tmp;
2577 struct tty_port *port = dev_get_drvdata(dev);
2579 uart_get_info(port, &tmp);
2580 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2583 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2584 struct device_attribute *attr, char *buf)
2586 struct serial_struct tmp;
2587 struct tty_port *port = dev_get_drvdata(dev);
2589 uart_get_info(port, &tmp);
2590 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2593 static ssize_t uart_get_attr_io_type(struct device *dev,
2594 struct device_attribute *attr, char *buf)
2596 struct serial_struct tmp;
2597 struct tty_port *port = dev_get_drvdata(dev);
2599 uart_get_info(port, &tmp);
2600 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2603 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2604 struct device_attribute *attr, char *buf)
2606 struct serial_struct tmp;
2607 struct tty_port *port = dev_get_drvdata(dev);
2609 uart_get_info(port, &tmp);
2610 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2613 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2614 struct device_attribute *attr, char *buf)
2616 struct serial_struct tmp;
2617 struct tty_port *port = dev_get_drvdata(dev);
2619 uart_get_info(port, &tmp);
2620 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2623 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2624 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2625 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2626 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2627 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2628 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2629 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2630 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2631 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2632 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2633 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2634 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2635 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2637 static struct attribute *tty_dev_attrs[] = {
2638 &dev_attr_type.attr,
2639 &dev_attr_line.attr,
2640 &dev_attr_port.attr,
2642 &dev_attr_flags.attr,
2643 &dev_attr_xmit_fifo_size.attr,
2644 &dev_attr_uartclk.attr,
2645 &dev_attr_close_delay.attr,
2646 &dev_attr_closing_wait.attr,
2647 &dev_attr_custom_divisor.attr,
2648 &dev_attr_io_type.attr,
2649 &dev_attr_iomem_base.attr,
2650 &dev_attr_iomem_reg_shift.attr,
2654 static const struct attribute_group tty_dev_attr_group = {
2655 .attrs = tty_dev_attrs,
2659 * uart_add_one_port - attach a driver-defined port structure
2660 * @drv: pointer to the uart low level driver structure for this port
2661 * @uport: uart port structure to use for this port.
2663 * This allows the driver to register its own uart_port structure
2664 * with the core driver. The main purpose is to allow the low
2665 * level uart drivers to expand uart_port, rather than having yet
2666 * more levels of structures.
2668 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2670 struct uart_state *state;
2671 struct tty_port *port;
2673 struct device *tty_dev;
2676 BUG_ON(in_interrupt());
2678 if (uport->line >= drv->nr)
2681 state = drv->state + uport->line;
2682 port = &state->port;
2684 mutex_lock(&port_mutex);
2685 mutex_lock(&port->mutex);
2686 if (state->uart_port) {
2691 /* Link the port to the driver state table and vice versa */
2692 state->uart_port = uport;
2693 uport->state = state;
2695 state->pm_state = UART_PM_STATE_UNDEFINED;
2696 uport->cons = drv->cons;
2697 uport->minor = drv->tty_driver->minor_start + uport->line;
2700 * If this port is a console, then the spinlock is already
2703 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2704 spin_lock_init(&uport->lock);
2705 lockdep_set_class(&uport->lock, &port_lock_key);
2707 if (uport->cons && uport->dev)
2708 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2710 uart_configure_port(drv, state, uport);
2713 if (uport->attr_group)
2716 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2718 if (!uport->tty_groups) {
2722 uport->tty_groups[0] = &tty_dev_attr_group;
2723 if (uport->attr_group)
2724 uport->tty_groups[1] = uport->attr_group;
2727 * Register the port whether it's detected or not. This allows
2728 * setserial to be used to alter this port's parameters.
2730 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2731 uport->line, uport->dev, port, uport->tty_groups);
2732 if (likely(!IS_ERR(tty_dev))) {
2733 device_set_wakeup_capable(tty_dev, 1);
2735 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2740 * Ensure UPF_DEAD is not set.
2742 uport->flags &= ~UPF_DEAD;
2745 mutex_unlock(&port->mutex);
2746 mutex_unlock(&port_mutex);
2752 * uart_remove_one_port - detach a driver defined port structure
2753 * @drv: pointer to the uart low level driver structure for this port
2754 * @uport: uart port structure for this port
2756 * This unhooks (and hangs up) the specified port structure from the
2757 * core driver. No further calls will be made to the low-level code
2760 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2762 struct uart_state *state = drv->state + uport->line;
2763 struct tty_port *port = &state->port;
2764 struct tty_struct *tty;
2767 BUG_ON(in_interrupt());
2769 if (state->uart_port != uport)
2770 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2771 state->uart_port, uport);
2773 mutex_lock(&port_mutex);
2776 * Mark the port "dead" - this prevents any opens from
2777 * succeeding while we shut down the port.
2779 mutex_lock(&port->mutex);
2780 if (!state->uart_port) {
2781 mutex_unlock(&port->mutex);
2785 uport->flags |= UPF_DEAD;
2786 mutex_unlock(&port->mutex);
2789 * Remove the devices from the tty layer
2791 tty_unregister_device(drv->tty_driver, uport->line);
2793 tty = tty_port_tty_get(port);
2795 tty_vhangup(port->tty);
2800 * If the port is used as a console, unregister it
2802 if (uart_console(uport))
2803 unregister_console(uport->cons);
2806 * Free the port IO and memory resources, if any.
2808 if (uport->type != PORT_UNKNOWN)
2809 uport->ops->release_port(uport);
2810 kfree(uport->tty_groups);
2813 * Indicate that there isn't a port here anymore.
2815 uport->type = PORT_UNKNOWN;
2817 state->uart_port = NULL;
2819 mutex_unlock(&port_mutex);
2825 * Are the two ports equivalent?
2827 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2829 if (port1->iotype != port2->iotype)
2832 switch (port1->iotype) {
2834 return (port1->iobase == port2->iobase);
2836 return (port1->iobase == port2->iobase) &&
2837 (port1->hub6 == port2->hub6);
2843 return (port1->mapbase == port2->mapbase);
2847 EXPORT_SYMBOL(uart_match_port);
2850 * uart_handle_dcd_change - handle a change of carrier detect state
2851 * @uport: uart_port structure for the open port
2852 * @status: new carrier detect status, nonzero if active
2854 * Caller must hold uport->lock
2856 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2858 struct tty_port *port = &uport->state->port;
2859 struct tty_struct *tty = port->tty;
2860 struct tty_ldisc *ld;
2862 lockdep_assert_held_once(&uport->lock);
2865 ld = tty_ldisc_ref(tty);
2867 if (ld->ops->dcd_change)
2868 ld->ops->dcd_change(tty, status);
2869 tty_ldisc_deref(ld);
2873 uport->icount.dcd++;
2875 if (uart_dcd_enabled(uport)) {
2877 wake_up_interruptible(&port->open_wait);
2882 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2885 * uart_handle_cts_change - handle a change of clear-to-send state
2886 * @uport: uart_port structure for the open port
2887 * @status: new clear to send status, nonzero if active
2889 * Caller must hold uport->lock
2891 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2893 lockdep_assert_held_once(&uport->lock);
2895 uport->icount.cts++;
2897 if (uart_softcts_mode(uport)) {
2898 if (uport->hw_stopped) {
2900 uport->hw_stopped = 0;
2901 uport->ops->start_tx(uport);
2902 uart_write_wakeup(uport);
2906 uport->hw_stopped = 1;
2907 uport->ops->stop_tx(uport);
2913 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2916 * uart_insert_char - push a char to the uart layer
2918 * User is responsible to call tty_flip_buffer_push when they are done with
2921 * @port: corresponding port
2922 * @status: state of the serial port RX buffer (LSR for 8250)
2923 * @overrun: mask of overrun bits in @status
2924 * @ch: character to push
2925 * @flag: flag for the character (see TTY_NORMAL and friends)
2927 void uart_insert_char(struct uart_port *port, unsigned int status,
2928 unsigned int overrun, unsigned int ch, unsigned int flag)
2930 struct tty_port *tport = &port->state->port;
2932 if ((status & port->ignore_status_mask & ~overrun) == 0)
2933 if (tty_insert_flip_char(tport, ch, flag) == 0)
2934 ++port->icount.buf_overrun;
2937 * Overrun is special. Since it's reported immediately,
2938 * it doesn't affect the current character.
2940 if (status & ~port->ignore_status_mask & overrun)
2941 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2942 ++port->icount.buf_overrun;
2944 EXPORT_SYMBOL_GPL(uart_insert_char);
2946 EXPORT_SYMBOL(uart_write_wakeup);
2947 EXPORT_SYMBOL(uart_register_driver);
2948 EXPORT_SYMBOL(uart_unregister_driver);
2949 EXPORT_SYMBOL(uart_suspend_port);
2950 EXPORT_SYMBOL(uart_resume_port);
2951 EXPORT_SYMBOL(uart_add_one_port);
2952 EXPORT_SYMBOL(uart_remove_one_port);
2954 MODULE_DESCRIPTION("Serial driver core");
2955 MODULE_LICENSE("GPL");