2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/serial_core.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
42 * This is used to lock changes in serial line configuration.
44 static DEFINE_MUTEX(port_mutex);
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
50 static struct lock_class_key port_lock_key;
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57 static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
60 static void uart_port_shutdown(struct tty_port *port);
63 * This routine is used by the interrupt handler to schedule processing in
64 * the software interrupt portion of the driver.
66 void uart_write_wakeup(struct uart_port *port)
68 struct uart_state *state = port->state;
70 * This means you called this function _after_ the port was
71 * closed. No cookie for you.
74 tty_wakeup(state->port.tty);
77 static void uart_stop(struct tty_struct *tty)
79 struct uart_state *state = tty->driver_data;
80 struct uart_port *port = state->uart_port;
83 spin_lock_irqsave(&port->lock, flags);
84 port->ops->stop_tx(port);
85 spin_unlock_irqrestore(&port->lock, flags);
88 static void __uart_start(struct tty_struct *tty)
90 struct uart_state *state = tty->driver_data;
91 struct uart_port *port = state->uart_port;
93 if (!tty->stopped && !tty->hw_stopped)
94 port->ops->start_tx(port);
97 static void uart_start(struct tty_struct *tty)
99 struct uart_state *state = tty->driver_data;
100 struct uart_port *port = state->uart_port;
103 spin_lock_irqsave(&port->lock, flags);
105 spin_unlock_irqrestore(&port->lock, flags);
109 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
114 spin_lock_irqsave(&port->lock, flags);
116 port->mctrl = (old & ~clear) | set;
117 if (old != port->mctrl)
118 port->ops->set_mctrl(port, port->mctrl);
119 spin_unlock_irqrestore(&port->lock, flags);
122 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
123 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
126 * Startup the port. This will be called once per open. All calls
127 * will be serialised by the per-port mutex.
129 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
132 struct uart_port *uport = state->uart_port;
133 struct tty_port *port = &state->port;
137 if (uport->type == PORT_UNKNOWN)
141 * Make sure the device is in D0 state.
143 uart_change_pm(state, UART_PM_STATE_ON);
146 * Initialise and allocate the transmit and temporary
149 if (!state->xmit.buf) {
150 /* This is protected by the per port mutex */
151 page = get_zeroed_page(GFP_KERNEL);
155 state->xmit.buf = (unsigned char *) page;
156 uart_circ_clear(&state->xmit);
159 retval = uport->ops->startup(uport);
161 if (uart_console(uport) && uport->cons->cflag) {
162 tty->termios.c_cflag = uport->cons->cflag;
163 uport->cons->cflag = 0;
166 * Initialise the hardware port settings.
168 uart_change_speed(tty, state, NULL);
172 * Setup the RTS and DTR signals once the
173 * port is open and ready to respond.
175 if (tty->termios.c_cflag & CBAUD)
176 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
179 * if hw support flow control without software intervention,
180 * then skip the below check
182 if (tty_port_cts_enabled(port) &&
183 !(uport->flags & UPF_HARD_FLOW)) {
184 spin_lock_irq(&uport->lock);
185 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
187 spin_unlock_irq(&uport->lock);
192 * This is to allow setserial on this port. People may want to set
193 * port/irq/type and then reconfigure the port properly if it failed
196 if (retval && capable(CAP_SYS_ADMIN))
202 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
205 struct tty_port *port = &state->port;
208 if (port->flags & ASYNC_INITIALIZED)
212 * Set the TTY IO error marker - we will only clear this
213 * once we have successfully opened the port.
215 set_bit(TTY_IO_ERROR, &tty->flags);
217 retval = uart_port_startup(tty, state, init_hw);
219 set_bit(ASYNCB_INITIALIZED, &port->flags);
220 clear_bit(TTY_IO_ERROR, &tty->flags);
221 } else if (retval > 0)
228 * This routine will shutdown a serial port; interrupts are disabled, and
229 * DTR is dropped if the hangup on close termio flag is on. Calls to
230 * uart_shutdown are serialised by the per-port semaphore.
232 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
234 struct uart_port *uport = state->uart_port;
235 struct tty_port *port = &state->port;
238 * Set the TTY IO error marker
241 set_bit(TTY_IO_ERROR, &tty->flags);
243 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
245 * Turn off DTR and RTS early.
247 if (uart_console(uport) && tty)
248 uport->cons->cflag = tty->termios.c_cflag;
250 if (!tty || (tty->termios.c_cflag & HUPCL))
251 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
253 uart_port_shutdown(port);
257 * It's possible for shutdown to be called after suspend if we get
258 * a DCD drop (hangup) at just the right time. Clear suspended bit so
259 * we don't try to resume a port that has been shutdown.
261 clear_bit(ASYNCB_SUSPENDED, &port->flags);
264 * Free the transmit buffer page.
266 if (state->xmit.buf) {
267 free_page((unsigned long)state->xmit.buf);
268 state->xmit.buf = NULL;
273 * uart_update_timeout - update per-port FIFO timeout.
274 * @port: uart_port structure describing the port
275 * @cflag: termios cflag value
276 * @baud: speed of the port
278 * Set the port FIFO timeout value. The @cflag value should
279 * reflect the actual hardware settings.
282 uart_update_timeout(struct uart_port *port, unsigned int cflag,
287 /* byte size and parity */
288 switch (cflag & CSIZE) {
309 * The total number of bits to be transmitted in the fifo.
311 bits = bits * port->fifosize;
314 * Figure the timeout to send the above number of bits.
315 * Add .02 seconds of slop
317 port->timeout = (HZ * bits) / baud + HZ/50;
320 EXPORT_SYMBOL(uart_update_timeout);
323 * uart_get_baud_rate - return baud rate for a particular port
324 * @port: uart_port structure describing the port in question.
325 * @termios: desired termios settings.
326 * @old: old termios (or NULL)
327 * @min: minimum acceptable baud rate
328 * @max: maximum acceptable baud rate
330 * Decode the termios structure into a numeric baud rate,
331 * taking account of the magic 38400 baud rate (with spd_*
332 * flags), and mapping the %B0 rate to 9600 baud.
334 * If the new baud rate is invalid, try the old termios setting.
335 * If it's still invalid, we try 9600 baud.
337 * Update the @termios structure to reflect the baud rate
338 * we're actually going to be using. Don't do this for the case
339 * where B0 is requested ("hang up").
342 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
343 struct ktermios *old, unsigned int min, unsigned int max)
345 unsigned int try, baud, altbaud = 38400;
347 upf_t flags = port->flags & UPF_SPD_MASK;
349 if (flags == UPF_SPD_HI)
351 else if (flags == UPF_SPD_VHI)
353 else if (flags == UPF_SPD_SHI)
355 else if (flags == UPF_SPD_WARP)
358 for (try = 0; try < 2; try++) {
359 baud = tty_termios_baud_rate(termios);
362 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
369 * Special case: B0 rate.
376 if (baud >= min && baud <= max)
380 * Oops, the quotient was zero. Try again with
381 * the old baud rate if possible.
383 termios->c_cflag &= ~CBAUD;
385 baud = tty_termios_baud_rate(old);
387 tty_termios_encode_baud_rate(termios,
394 * As a last resort, if the range cannot be met then clip to
395 * the nearest chip supported rate.
399 tty_termios_encode_baud_rate(termios,
402 tty_termios_encode_baud_rate(termios,
406 /* Should never happen */
411 EXPORT_SYMBOL(uart_get_baud_rate);
414 * uart_get_divisor - return uart clock divisor
415 * @port: uart_port structure describing the port.
416 * @baud: desired baud rate
418 * Calculate the uart clock divisor for the port.
421 uart_get_divisor(struct uart_port *port, unsigned int baud)
426 * Old custom speed handling.
428 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
429 quot = port->custom_divisor;
431 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
436 EXPORT_SYMBOL(uart_get_divisor);
438 /* FIXME: Consistent locking policy */
439 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
440 struct ktermios *old_termios)
442 struct tty_port *port = &state->port;
443 struct uart_port *uport = state->uart_port;
444 struct ktermios *termios;
447 * If we have no tty, termios, or the port does not exist,
448 * then we can't set the parameters for this port.
450 if (!tty || uport->type == PORT_UNKNOWN)
453 termios = &tty->termios;
454 uport->ops->set_termios(uport, termios, old_termios);
457 * Set flags based on termios cflag
459 if (termios->c_cflag & CRTSCTS)
460 set_bit(ASYNCB_CTS_FLOW, &port->flags);
462 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
464 if (termios->c_cflag & CLOCAL)
465 clear_bit(ASYNCB_CHECK_CD, &port->flags);
467 set_bit(ASYNCB_CHECK_CD, &port->flags);
470 static inline int __uart_put_char(struct uart_port *port,
471 struct circ_buf *circ, unsigned char c)
479 spin_lock_irqsave(&port->lock, flags);
480 if (uart_circ_chars_free(circ) != 0) {
481 circ->buf[circ->head] = c;
482 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
485 spin_unlock_irqrestore(&port->lock, flags);
489 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
491 struct uart_state *state = tty->driver_data;
493 return __uart_put_char(state->uart_port, &state->xmit, ch);
496 static void uart_flush_chars(struct tty_struct *tty)
501 static int uart_write(struct tty_struct *tty,
502 const unsigned char *buf, int count)
504 struct uart_state *state = tty->driver_data;
505 struct uart_port *port;
506 struct circ_buf *circ;
511 * This means you called this function _after_ the port was
512 * closed. No cookie for you.
519 port = state->uart_port;
525 spin_lock_irqsave(&port->lock, flags);
527 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
532 memcpy(circ->buf + circ->head, buf, c);
533 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
538 spin_unlock_irqrestore(&port->lock, flags);
544 static int uart_write_room(struct tty_struct *tty)
546 struct uart_state *state = tty->driver_data;
550 spin_lock_irqsave(&state->uart_port->lock, flags);
551 ret = uart_circ_chars_free(&state->xmit);
552 spin_unlock_irqrestore(&state->uart_port->lock, flags);
556 static int uart_chars_in_buffer(struct tty_struct *tty)
558 struct uart_state *state = tty->driver_data;
562 spin_lock_irqsave(&state->uart_port->lock, flags);
563 ret = uart_circ_chars_pending(&state->xmit);
564 spin_unlock_irqrestore(&state->uart_port->lock, flags);
568 static void uart_flush_buffer(struct tty_struct *tty)
570 struct uart_state *state = tty->driver_data;
571 struct uart_port *port;
575 * This means you called this function _after_ the port was
576 * closed. No cookie for you.
583 port = state->uart_port;
584 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
586 spin_lock_irqsave(&port->lock, flags);
587 uart_circ_clear(&state->xmit);
588 if (port->ops->flush_buffer)
589 port->ops->flush_buffer(port);
590 spin_unlock_irqrestore(&port->lock, flags);
595 * This function is used to send a high-priority XON/XOFF character to
598 static void uart_send_xchar(struct tty_struct *tty, char ch)
600 struct uart_state *state = tty->driver_data;
601 struct uart_port *port = state->uart_port;
604 if (port->ops->send_xchar)
605 port->ops->send_xchar(port, ch);
609 spin_lock_irqsave(&port->lock, flags);
610 port->ops->start_tx(port);
611 spin_unlock_irqrestore(&port->lock, flags);
616 static void uart_throttle(struct tty_struct *tty)
618 struct uart_state *state = tty->driver_data;
619 struct uart_port *port = state->uart_port;
623 mask |= UPF_SOFT_FLOW;
624 if (tty->termios.c_cflag & CRTSCTS)
625 mask |= UPF_HARD_FLOW;
627 if (port->flags & mask) {
628 port->ops->throttle(port);
629 mask &= ~port->flags;
632 if (mask & UPF_SOFT_FLOW)
633 uart_send_xchar(tty, STOP_CHAR(tty));
635 if (mask & UPF_HARD_FLOW)
636 uart_clear_mctrl(port, TIOCM_RTS);
639 static void uart_unthrottle(struct tty_struct *tty)
641 struct uart_state *state = tty->driver_data;
642 struct uart_port *port = state->uart_port;
646 mask |= UPF_SOFT_FLOW;
647 if (tty->termios.c_cflag & CRTSCTS)
648 mask |= UPF_HARD_FLOW;
650 if (port->flags & mask) {
651 port->ops->unthrottle(port);
652 mask &= ~port->flags;
655 if (mask & UPF_SOFT_FLOW) {
659 uart_send_xchar(tty, START_CHAR(tty));
662 if (mask & UPF_HARD_FLOW)
663 uart_set_mctrl(port, TIOCM_RTS);
666 static void do_uart_get_info(struct tty_port *port,
667 struct serial_struct *retinfo)
669 struct uart_state *state = container_of(port, struct uart_state, port);
670 struct uart_port *uport = state->uart_port;
672 memset(retinfo, 0, sizeof(*retinfo));
674 retinfo->type = uport->type;
675 retinfo->line = uport->line;
676 retinfo->port = uport->iobase;
677 if (HIGH_BITS_OFFSET)
678 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
679 retinfo->irq = uport->irq;
680 retinfo->flags = uport->flags;
681 retinfo->xmit_fifo_size = uport->fifosize;
682 retinfo->baud_base = uport->uartclk / 16;
683 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
684 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
685 ASYNC_CLOSING_WAIT_NONE :
686 jiffies_to_msecs(port->closing_wait) / 10;
687 retinfo->custom_divisor = uport->custom_divisor;
688 retinfo->hub6 = uport->hub6;
689 retinfo->io_type = uport->iotype;
690 retinfo->iomem_reg_shift = uport->regshift;
691 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
694 static void uart_get_info(struct tty_port *port,
695 struct serial_struct *retinfo)
697 /* Ensure the state we copy is consistent and no hardware changes
699 mutex_lock(&port->mutex);
700 do_uart_get_info(port, retinfo);
701 mutex_unlock(&port->mutex);
704 static int uart_get_info_user(struct tty_port *port,
705 struct serial_struct __user *retinfo)
707 struct serial_struct tmp;
708 uart_get_info(port, &tmp);
710 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
715 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
716 struct uart_state *state,
717 struct serial_struct *new_info)
719 struct uart_port *uport = state->uart_port;
720 unsigned long new_port;
721 unsigned int change_irq, change_port, closing_wait;
722 unsigned int old_custom_divisor, close_delay;
723 upf_t old_flags, new_flags;
726 new_port = new_info->port;
727 if (HIGH_BITS_OFFSET)
728 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
730 new_info->irq = irq_canonicalize(new_info->irq);
731 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
732 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
733 ASYNC_CLOSING_WAIT_NONE :
734 msecs_to_jiffies(new_info->closing_wait * 10);
737 change_irq = !(uport->flags & UPF_FIXED_PORT)
738 && new_info->irq != uport->irq;
741 * Since changing the 'type' of the port changes its resource
742 * allocations, we should treat type changes the same as
745 change_port = !(uport->flags & UPF_FIXED_PORT)
746 && (new_port != uport->iobase ||
747 (unsigned long)new_info->iomem_base != uport->mapbase ||
748 new_info->hub6 != uport->hub6 ||
749 new_info->io_type != uport->iotype ||
750 new_info->iomem_reg_shift != uport->regshift ||
751 new_info->type != uport->type);
753 old_flags = uport->flags;
754 new_flags = new_info->flags;
755 old_custom_divisor = uport->custom_divisor;
757 if (!capable(CAP_SYS_ADMIN)) {
759 if (change_irq || change_port ||
760 (new_info->baud_base != uport->uartclk / 16) ||
761 (close_delay != port->close_delay) ||
762 (closing_wait != port->closing_wait) ||
763 (new_info->xmit_fifo_size &&
764 new_info->xmit_fifo_size != uport->fifosize) ||
765 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
767 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
768 (new_flags & UPF_USR_MASK));
769 uport->custom_divisor = new_info->custom_divisor;
774 * Ask the low level driver to verify the settings.
776 if (uport->ops->verify_port)
777 retval = uport->ops->verify_port(uport, new_info);
779 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
780 (new_info->baud_base < 9600))
786 if (change_port || change_irq) {
790 * Make sure that we are the sole user of this port.
792 if (tty_port_users(port) > 1)
796 * We need to shutdown the serial port at the old
797 * port/type/irq combination.
799 uart_shutdown(tty, state);
803 unsigned long old_iobase, old_mapbase;
804 unsigned int old_type, old_iotype, old_hub6, old_shift;
806 old_iobase = uport->iobase;
807 old_mapbase = uport->mapbase;
808 old_type = uport->type;
809 old_hub6 = uport->hub6;
810 old_iotype = uport->iotype;
811 old_shift = uport->regshift;
814 * Free and release old regions
816 if (old_type != PORT_UNKNOWN)
817 uport->ops->release_port(uport);
819 uport->iobase = new_port;
820 uport->type = new_info->type;
821 uport->hub6 = new_info->hub6;
822 uport->iotype = new_info->io_type;
823 uport->regshift = new_info->iomem_reg_shift;
824 uport->mapbase = (unsigned long)new_info->iomem_base;
827 * Claim and map the new regions
829 if (uport->type != PORT_UNKNOWN) {
830 retval = uport->ops->request_port(uport);
832 /* Always success - Jean II */
837 * If we fail to request resources for the
838 * new port, try to restore the old settings.
841 uport->iobase = old_iobase;
842 uport->type = old_type;
843 uport->hub6 = old_hub6;
844 uport->iotype = old_iotype;
845 uport->regshift = old_shift;
846 uport->mapbase = old_mapbase;
848 if (old_type != PORT_UNKNOWN) {
849 retval = uport->ops->request_port(uport);
851 * If we failed to restore the old settings,
855 uport->type = PORT_UNKNOWN;
863 /* Added to return the correct error -Ram Gupta */
869 uport->irq = new_info->irq;
870 if (!(uport->flags & UPF_FIXED_PORT))
871 uport->uartclk = new_info->baud_base * 16;
872 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
873 (new_flags & UPF_CHANGE_MASK);
874 uport->custom_divisor = new_info->custom_divisor;
875 port->close_delay = close_delay;
876 port->closing_wait = closing_wait;
877 if (new_info->xmit_fifo_size)
878 uport->fifosize = new_info->xmit_fifo_size;
879 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
883 if (uport->type == PORT_UNKNOWN)
885 if (port->flags & ASYNC_INITIALIZED) {
886 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
887 old_custom_divisor != uport->custom_divisor) {
889 * If they're setting up a custom divisor or speed,
890 * instead of clearing it, then bitch about it. No
891 * need to rate-limit; it's CAP_SYS_ADMIN only.
893 if (uport->flags & UPF_SPD_MASK) {
896 dev_notice(uport->dev,
897 "%s sets custom speed on %s. This is deprecated.\n",
899 tty_name(port->tty, buf));
901 uart_change_speed(tty, state, NULL);
904 retval = uart_startup(tty, state, 1);
909 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
910 struct serial_struct __user *newinfo)
912 struct serial_struct new_serial;
913 struct tty_port *port = &state->port;
916 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
920 * This semaphore protects port->count. It is also
921 * very useful to prevent opens. Also, take the
922 * port configuration semaphore to make sure that a
923 * module insertion/removal doesn't change anything
926 mutex_lock(&port->mutex);
927 retval = uart_set_info(tty, port, state, &new_serial);
928 mutex_unlock(&port->mutex);
933 * uart_get_lsr_info - get line status register info
934 * @tty: tty associated with the UART
935 * @state: UART being queried
936 * @value: returned modem value
938 * Note: uart_ioctl protects us against hangups.
940 static int uart_get_lsr_info(struct tty_struct *tty,
941 struct uart_state *state, unsigned int __user *value)
943 struct uart_port *uport = state->uart_port;
946 result = uport->ops->tx_empty(uport);
949 * If we're about to load something into the transmit
950 * register, we'll pretend the transmitter isn't empty to
951 * avoid a race condition (depending on when the transmit
952 * interrupt happens).
955 ((uart_circ_chars_pending(&state->xmit) > 0) &&
956 !tty->stopped && !tty->hw_stopped))
957 result &= ~TIOCSER_TEMT;
959 return put_user(result, value);
962 static int uart_tiocmget(struct tty_struct *tty)
964 struct uart_state *state = tty->driver_data;
965 struct tty_port *port = &state->port;
966 struct uart_port *uport = state->uart_port;
969 mutex_lock(&port->mutex);
970 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
971 result = uport->mctrl;
972 spin_lock_irq(&uport->lock);
973 result |= uport->ops->get_mctrl(uport);
974 spin_unlock_irq(&uport->lock);
976 mutex_unlock(&port->mutex);
982 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
984 struct uart_state *state = tty->driver_data;
985 struct uart_port *uport = state->uart_port;
986 struct tty_port *port = &state->port;
989 mutex_lock(&port->mutex);
990 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
991 uart_update_mctrl(uport, set, clear);
994 mutex_unlock(&port->mutex);
998 static int uart_break_ctl(struct tty_struct *tty, int break_state)
1000 struct uart_state *state = tty->driver_data;
1001 struct tty_port *port = &state->port;
1002 struct uart_port *uport = state->uart_port;
1004 mutex_lock(&port->mutex);
1006 if (uport->type != PORT_UNKNOWN)
1007 uport->ops->break_ctl(uport, break_state);
1009 mutex_unlock(&port->mutex);
1013 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1015 struct uart_port *uport = state->uart_port;
1016 struct tty_port *port = &state->port;
1019 if (!capable(CAP_SYS_ADMIN))
1023 * Take the per-port semaphore. This prevents count from
1024 * changing, and hence any extra opens of the port while
1025 * we're auto-configuring.
1027 if (mutex_lock_interruptible(&port->mutex))
1028 return -ERESTARTSYS;
1031 if (tty_port_users(port) == 1) {
1032 uart_shutdown(tty, state);
1035 * If we already have a port type configured,
1036 * we must release its resources.
1038 if (uport->type != PORT_UNKNOWN)
1039 uport->ops->release_port(uport);
1041 flags = UART_CONFIG_TYPE;
1042 if (uport->flags & UPF_AUTO_IRQ)
1043 flags |= UART_CONFIG_IRQ;
1046 * This will claim the ports resources if
1049 uport->ops->config_port(uport, flags);
1051 ret = uart_startup(tty, state, 1);
1053 mutex_unlock(&port->mutex);
1057 static void uart_enable_ms(struct uart_port *uport)
1060 * Force modem status interrupts on
1062 if (uport->ops->enable_ms)
1063 uport->ops->enable_ms(uport);
1067 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1068 * - mask passed in arg for lines of interest
1069 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1070 * Caller should use TIOCGICOUNT to see which one it was
1072 * FIXME: This wants extracting into a common all driver implementation
1073 * of TIOCMWAIT using tty_port.
1076 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1078 struct uart_port *uport = state->uart_port;
1079 struct tty_port *port = &state->port;
1080 DECLARE_WAITQUEUE(wait, current);
1081 struct uart_icount cprev, cnow;
1085 * note the counters on entry
1087 spin_lock_irq(&uport->lock);
1088 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1089 uart_enable_ms(uport);
1090 spin_unlock_irq(&uport->lock);
1092 add_wait_queue(&port->delta_msr_wait, &wait);
1094 spin_lock_irq(&uport->lock);
1095 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1096 spin_unlock_irq(&uport->lock);
1098 set_current_state(TASK_INTERRUPTIBLE);
1100 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1101 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1102 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1103 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1110 /* see if a signal did it */
1111 if (signal_pending(current)) {
1119 current->state = TASK_RUNNING;
1120 remove_wait_queue(&port->delta_msr_wait, &wait);
1126 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1127 * Return: write counters to the user passed counter struct
1128 * NB: both 1->0 and 0->1 transitions are counted except for
1129 * RI where only 0->1 is counted.
1131 static int uart_get_icount(struct tty_struct *tty,
1132 struct serial_icounter_struct *icount)
1134 struct uart_state *state = tty->driver_data;
1135 struct uart_icount cnow;
1136 struct uart_port *uport = state->uart_port;
1138 spin_lock_irq(&uport->lock);
1139 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1140 spin_unlock_irq(&uport->lock);
1142 icount->cts = cnow.cts;
1143 icount->dsr = cnow.dsr;
1144 icount->rng = cnow.rng;
1145 icount->dcd = cnow.dcd;
1146 icount->rx = cnow.rx;
1147 icount->tx = cnow.tx;
1148 icount->frame = cnow.frame;
1149 icount->overrun = cnow.overrun;
1150 icount->parity = cnow.parity;
1151 icount->brk = cnow.brk;
1152 icount->buf_overrun = cnow.buf_overrun;
1158 * Called via sys_ioctl. We can use spin_lock_irq() here.
1161 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1164 struct uart_state *state = tty->driver_data;
1165 struct tty_port *port = &state->port;
1166 void __user *uarg = (void __user *)arg;
1167 int ret = -ENOIOCTLCMD;
1171 * These ioctls don't rely on the hardware to be present.
1175 ret = uart_get_info_user(port, uarg);
1179 ret = uart_set_info_user(tty, state, uarg);
1183 ret = uart_do_autoconfig(tty, state);
1186 case TIOCSERGWILD: /* obsolete */
1187 case TIOCSERSWILD: /* obsolete */
1192 if (ret != -ENOIOCTLCMD)
1195 if (tty->flags & (1 << TTY_IO_ERROR)) {
1201 * The following should only be used when hardware is present.
1205 ret = uart_wait_modem_status(state, arg);
1209 if (ret != -ENOIOCTLCMD)
1212 mutex_lock(&port->mutex);
1214 if (tty->flags & (1 << TTY_IO_ERROR)) {
1220 * All these rely on hardware being present and need to be
1221 * protected against the tty being hung up.
1224 case TIOCSERGETLSR: /* Get line status register */
1225 ret = uart_get_lsr_info(tty, state, uarg);
1229 struct uart_port *uport = state->uart_port;
1230 if (uport->ops->ioctl)
1231 ret = uport->ops->ioctl(uport, cmd, arg);
1236 mutex_unlock(&port->mutex);
1241 static void uart_set_ldisc(struct tty_struct *tty)
1243 struct uart_state *state = tty->driver_data;
1244 struct uart_port *uport = state->uart_port;
1246 if (uport->ops->set_ldisc)
1247 uport->ops->set_ldisc(uport, tty->termios.c_line);
1250 static void uart_set_termios(struct tty_struct *tty,
1251 struct ktermios *old_termios)
1253 struct uart_state *state = tty->driver_data;
1254 struct uart_port *uport = state->uart_port;
1255 unsigned long flags;
1256 unsigned int cflag = tty->termios.c_cflag;
1257 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1258 bool sw_changed = false;
1261 * Drivers doing software flow control also need to know
1262 * about changes to these input settings.
1264 if (uport->flags & UPF_SOFT_FLOW) {
1265 iflag_mask |= IXANY|IXON|IXOFF;
1267 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1268 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1272 * These are the bits that are used to setup various
1273 * flags in the low level driver. We can ignore the Bfoo
1274 * bits in c_cflag; c_[io]speed will always be set
1275 * appropriately by set_termios() in tty_ioctl.c
1277 if ((cflag ^ old_termios->c_cflag) == 0 &&
1278 tty->termios.c_ospeed == old_termios->c_ospeed &&
1279 tty->termios.c_ispeed == old_termios->c_ispeed &&
1280 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1285 uart_change_speed(tty, state, old_termios);
1286 /* reload cflag from termios; port driver may have overriden flags */
1287 cflag = tty->termios.c_cflag;
1289 /* Handle transition to B0 status */
1290 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1291 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1292 /* Handle transition away from B0 status */
1293 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1294 unsigned int mask = TIOCM_DTR;
1295 if (!(cflag & CRTSCTS) ||
1296 !test_bit(TTY_THROTTLED, &tty->flags))
1298 uart_set_mctrl(uport, mask);
1302 * If the port is doing h/w assisted flow control, do nothing.
1303 * We assume that tty->hw_stopped has never been set.
1305 if (uport->flags & UPF_HARD_FLOW)
1308 /* Handle turning off CRTSCTS */
1309 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1310 spin_lock_irqsave(&uport->lock, flags);
1311 tty->hw_stopped = 0;
1313 spin_unlock_irqrestore(&uport->lock, flags);
1315 /* Handle turning on CRTSCTS */
1316 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1317 spin_lock_irqsave(&uport->lock, flags);
1318 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1319 tty->hw_stopped = 1;
1320 uport->ops->stop_tx(uport);
1322 spin_unlock_irqrestore(&uport->lock, flags);
1327 * Calls to uart_close() are serialised via the tty_lock in
1328 * drivers/tty/tty_io.c:tty_release()
1329 * drivers/tty/tty_io.c:do_tty_hangup()
1330 * This runs from a workqueue and can sleep for a _short_ time only.
1332 static void uart_close(struct tty_struct *tty, struct file *filp)
1334 struct uart_state *state = tty->driver_data;
1335 struct tty_port *port;
1336 struct uart_port *uport;
1337 unsigned long flags;
1342 uport = state->uart_port;
1343 port = &state->port;
1345 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1347 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1351 * At this point, we stop accepting input. To do this, we
1352 * disable the receive line status interrupts.
1354 if (port->flags & ASYNC_INITIALIZED) {
1355 unsigned long flags;
1356 spin_lock_irqsave(&uport->lock, flags);
1357 uport->ops->stop_rx(uport);
1358 spin_unlock_irqrestore(&uport->lock, flags);
1360 * Before we drop DTR, make sure the UART transmitter
1361 * has completely drained; this is especially
1362 * important if there is a transmit FIFO!
1364 uart_wait_until_sent(tty, uport->timeout);
1367 mutex_lock(&port->mutex);
1368 uart_shutdown(tty, state);
1369 uart_flush_buffer(tty);
1371 tty_ldisc_flush(tty);
1373 tty_port_tty_set(port, NULL);
1375 spin_lock_irqsave(&port->lock, flags);
1377 if (port->blocked_open) {
1378 spin_unlock_irqrestore(&port->lock, flags);
1379 if (port->close_delay)
1380 msleep_interruptible(
1381 jiffies_to_msecs(port->close_delay));
1382 spin_lock_irqsave(&port->lock, flags);
1383 } else if (!uart_console(uport)) {
1384 spin_unlock_irqrestore(&port->lock, flags);
1385 uart_change_pm(state, UART_PM_STATE_OFF);
1386 spin_lock_irqsave(&port->lock, flags);
1390 * Wake up anyone trying to open this port.
1392 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1393 clear_bit(ASYNCB_CLOSING, &port->flags);
1394 spin_unlock_irqrestore(&port->lock, flags);
1395 wake_up_interruptible(&port->open_wait);
1396 wake_up_interruptible(&port->close_wait);
1398 mutex_unlock(&port->mutex);
1401 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1403 struct uart_state *state = tty->driver_data;
1404 struct uart_port *port = state->uart_port;
1405 unsigned long char_time, expire;
1407 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1411 * Set the check interval to be 1/5 of the estimated time to
1412 * send a single character, and make it at least 1. The check
1413 * interval should also be less than the timeout.
1415 * Note: we have to use pretty tight timings here to satisfy
1418 char_time = (port->timeout - HZ/50) / port->fifosize;
1419 char_time = char_time / 5;
1422 if (timeout && timeout < char_time)
1423 char_time = timeout;
1426 * If the transmitter hasn't cleared in twice the approximate
1427 * amount of time to send the entire FIFO, it probably won't
1428 * ever clear. This assumes the UART isn't doing flow
1429 * control, which is currently the case. Hence, if it ever
1430 * takes longer than port->timeout, this is probably due to a
1431 * UART bug of some kind. So, we clamp the timeout parameter at
1434 if (timeout == 0 || timeout > 2 * port->timeout)
1435 timeout = 2 * port->timeout;
1437 expire = jiffies + timeout;
1439 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1440 port->line, jiffies, expire);
1443 * Check whether the transmitter is empty every 'char_time'.
1444 * 'timeout' / 'expire' give us the maximum amount of time
1447 while (!port->ops->tx_empty(port)) {
1448 msleep_interruptible(jiffies_to_msecs(char_time));
1449 if (signal_pending(current))
1451 if (time_after(jiffies, expire))
1457 * Calls to uart_hangup() are serialised by the tty_lock in
1458 * drivers/tty/tty_io.c:do_tty_hangup()
1459 * This runs from a workqueue and can sleep for a _short_ time only.
1461 static void uart_hangup(struct tty_struct *tty)
1463 struct uart_state *state = tty->driver_data;
1464 struct tty_port *port = &state->port;
1465 unsigned long flags;
1467 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1469 mutex_lock(&port->mutex);
1470 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1471 uart_flush_buffer(tty);
1472 uart_shutdown(tty, state);
1473 spin_lock_irqsave(&port->lock, flags);
1475 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1476 spin_unlock_irqrestore(&port->lock, flags);
1477 tty_port_tty_set(port, NULL);
1478 if (!uart_console(state->uart_port))
1479 uart_change_pm(state, UART_PM_STATE_OFF);
1480 wake_up_interruptible(&port->open_wait);
1481 wake_up_interruptible(&port->delta_msr_wait);
1483 mutex_unlock(&port->mutex);
1486 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1491 static void uart_port_shutdown(struct tty_port *port)
1493 struct uart_state *state = container_of(port, struct uart_state, port);
1494 struct uart_port *uport = state->uart_port;
1497 * clear delta_msr_wait queue to avoid mem leaks: we may free
1498 * the irq here so the queue might never be woken up. Note
1499 * that we won't end up waiting on delta_msr_wait again since
1500 * any outstanding file descriptors should be pointing at
1501 * hung_up_tty_fops now.
1503 wake_up_interruptible(&port->delta_msr_wait);
1506 * Free the IRQ and disable the port.
1508 uport->ops->shutdown(uport);
1511 * Ensure that the IRQ handler isn't running on another CPU.
1513 synchronize_irq(uport->irq);
1516 static int uart_carrier_raised(struct tty_port *port)
1518 struct uart_state *state = container_of(port, struct uart_state, port);
1519 struct uart_port *uport = state->uart_port;
1521 spin_lock_irq(&uport->lock);
1522 uart_enable_ms(uport);
1523 mctrl = uport->ops->get_mctrl(uport);
1524 spin_unlock_irq(&uport->lock);
1525 if (mctrl & TIOCM_CAR)
1530 static void uart_dtr_rts(struct tty_port *port, int onoff)
1532 struct uart_state *state = container_of(port, struct uart_state, port);
1533 struct uart_port *uport = state->uart_port;
1536 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1538 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1542 * Calls to uart_open are serialised by the tty_lock in
1543 * drivers/tty/tty_io.c:tty_open()
1544 * Note that if this fails, then uart_close() _will_ be called.
1546 * In time, we want to scrap the "opening nonpresent ports"
1547 * behaviour and implement an alternative way for setserial
1548 * to set base addresses/ports/types. This will allow us to
1549 * get rid of a certain amount of extra tests.
1551 static int uart_open(struct tty_struct *tty, struct file *filp)
1553 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1554 int retval, line = tty->index;
1555 struct uart_state *state = drv->state + line;
1556 struct tty_port *port = &state->port;
1558 pr_debug("uart_open(%d) called\n", line);
1561 * We take the semaphore here to guarantee that we won't be re-entered
1562 * while allocating the state structure, or while we request any IRQs
1563 * that the driver may need. This also has the nice side-effect that
1564 * it delays the action of uart_hangup, so we can guarantee that
1565 * state->port.tty will always contain something reasonable.
1567 if (mutex_lock_interruptible(&port->mutex)) {
1568 retval = -ERESTARTSYS;
1573 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1579 * Once we set tty->driver_data here, we are guaranteed that
1580 * uart_close() will decrement the driver module use count.
1581 * Any failures from here onwards should not touch the count.
1583 tty->driver_data = state;
1584 state->uart_port->state = state;
1585 state->port.low_latency =
1586 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1587 tty_port_tty_set(port, tty);
1590 * Start up the serial port.
1592 retval = uart_startup(tty, state, 0);
1595 * If we succeeded, wait until the port is ready.
1597 mutex_unlock(&port->mutex);
1599 retval = tty_port_block_til_ready(port, tty, filp);
1605 mutex_unlock(&port->mutex);
1609 static const char *uart_type(struct uart_port *port)
1611 const char *str = NULL;
1613 if (port->ops->type)
1614 str = port->ops->type(port);
1622 #ifdef CONFIG_PROC_FS
1624 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1626 struct uart_state *state = drv->state + i;
1627 struct tty_port *port = &state->port;
1628 enum uart_pm_state pm_state;
1629 struct uart_port *uport = state->uart_port;
1631 unsigned int status;
1637 mmio = uport->iotype >= UPIO_MEM;
1638 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1639 uport->line, uart_type(uport),
1640 mmio ? "mmio:0x" : "port:",
1641 mmio ? (unsigned long long)uport->mapbase
1642 : (unsigned long long)uport->iobase,
1645 if (uport->type == PORT_UNKNOWN) {
1650 if (capable(CAP_SYS_ADMIN)) {
1651 mutex_lock(&port->mutex);
1652 pm_state = state->pm_state;
1653 if (pm_state != UART_PM_STATE_ON)
1654 uart_change_pm(state, UART_PM_STATE_ON);
1655 spin_lock_irq(&uport->lock);
1656 status = uport->ops->get_mctrl(uport);
1657 spin_unlock_irq(&uport->lock);
1658 if (pm_state != UART_PM_STATE_ON)
1659 uart_change_pm(state, pm_state);
1660 mutex_unlock(&port->mutex);
1662 seq_printf(m, " tx:%d rx:%d",
1663 uport->icount.tx, uport->icount.rx);
1664 if (uport->icount.frame)
1665 seq_printf(m, " fe:%d",
1666 uport->icount.frame);
1667 if (uport->icount.parity)
1668 seq_printf(m, " pe:%d",
1669 uport->icount.parity);
1670 if (uport->icount.brk)
1671 seq_printf(m, " brk:%d",
1673 if (uport->icount.overrun)
1674 seq_printf(m, " oe:%d",
1675 uport->icount.overrun);
1677 #define INFOBIT(bit, str) \
1678 if (uport->mctrl & (bit)) \
1679 strncat(stat_buf, (str), sizeof(stat_buf) - \
1680 strlen(stat_buf) - 2)
1681 #define STATBIT(bit, str) \
1682 if (status & (bit)) \
1683 strncat(stat_buf, (str), sizeof(stat_buf) - \
1684 strlen(stat_buf) - 2)
1688 INFOBIT(TIOCM_RTS, "|RTS");
1689 STATBIT(TIOCM_CTS, "|CTS");
1690 INFOBIT(TIOCM_DTR, "|DTR");
1691 STATBIT(TIOCM_DSR, "|DSR");
1692 STATBIT(TIOCM_CAR, "|CD");
1693 STATBIT(TIOCM_RNG, "|RI");
1697 seq_puts(m, stat_buf);
1704 static int uart_proc_show(struct seq_file *m, void *v)
1706 struct tty_driver *ttydrv = m->private;
1707 struct uart_driver *drv = ttydrv->driver_state;
1710 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1712 for (i = 0; i < drv->nr; i++)
1713 uart_line_info(m, drv, i);
1717 static int uart_proc_open(struct inode *inode, struct file *file)
1719 return single_open(file, uart_proc_show, PDE_DATA(inode));
1722 static const struct file_operations uart_proc_fops = {
1723 .owner = THIS_MODULE,
1724 .open = uart_proc_open,
1726 .llseek = seq_lseek,
1727 .release = single_release,
1731 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1733 * uart_console_write - write a console message to a serial port
1734 * @port: the port to write the message
1735 * @s: array of characters
1736 * @count: number of characters in string to write
1737 * @write: function to write character to port
1739 void uart_console_write(struct uart_port *port, const char *s,
1741 void (*putchar)(struct uart_port *, int))
1745 for (i = 0; i < count; i++, s++) {
1747 putchar(port, '\r');
1751 EXPORT_SYMBOL_GPL(uart_console_write);
1754 * Check whether an invalid uart number has been specified, and
1755 * if so, search for the first available port that does have
1758 struct uart_port * __init
1759 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1761 int idx = co->index;
1763 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1764 ports[idx].membase == NULL))
1765 for (idx = 0; idx < nr; idx++)
1766 if (ports[idx].iobase != 0 ||
1767 ports[idx].membase != NULL)
1776 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1777 * @options: pointer to option string
1778 * @baud: pointer to an 'int' variable for the baud rate.
1779 * @parity: pointer to an 'int' variable for the parity.
1780 * @bits: pointer to an 'int' variable for the number of data bits.
1781 * @flow: pointer to an 'int' variable for the flow control character.
1783 * uart_parse_options decodes a string containing the serial console
1784 * options. The format of the string is <baud><parity><bits><flow>,
1788 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1792 *baud = simple_strtoul(s, NULL, 10);
1793 while (*s >= '0' && *s <= '9')
1802 EXPORT_SYMBOL_GPL(uart_parse_options);
1809 static const struct baud_rates baud_rates[] = {
1810 { 921600, B921600 },
1811 { 460800, B460800 },
1812 { 230400, B230400 },
1813 { 115200, B115200 },
1825 * uart_set_options - setup the serial console parameters
1826 * @port: pointer to the serial ports uart_port structure
1827 * @co: console pointer
1829 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1830 * @bits: number of data bits
1831 * @flow: flow control character - 'r' (rts)
1834 uart_set_options(struct uart_port *port, struct console *co,
1835 int baud, int parity, int bits, int flow)
1837 struct ktermios termios;
1838 static struct ktermios dummy;
1842 * Ensure that the serial console lock is initialised
1844 * If this port is a console, then the spinlock is already
1847 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1848 spin_lock_init(&port->lock);
1849 lockdep_set_class(&port->lock, &port_lock_key);
1852 memset(&termios, 0, sizeof(struct ktermios));
1854 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1857 * Construct a cflag setting.
1859 for (i = 0; baud_rates[i].rate; i++)
1860 if (baud_rates[i].rate <= baud)
1863 termios.c_cflag |= baud_rates[i].cflag;
1866 termios.c_cflag |= CS7;
1868 termios.c_cflag |= CS8;
1872 termios.c_cflag |= PARODD;
1875 termios.c_cflag |= PARENB;
1880 termios.c_cflag |= CRTSCTS;
1883 * some uarts on other side don't support no flow control.
1884 * So we set * DTR in host uart to make them happy
1886 port->mctrl |= TIOCM_DTR;
1888 port->ops->set_termios(port, &termios, &dummy);
1890 * Allow the setting of the UART parameters with a NULL console
1894 co->cflag = termios.c_cflag;
1898 EXPORT_SYMBOL_GPL(uart_set_options);
1899 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1902 * uart_change_pm - set power state of the port
1904 * @state: port descriptor
1905 * @pm_state: new state
1907 * Locking: port->mutex has to be held
1909 static void uart_change_pm(struct uart_state *state,
1910 enum uart_pm_state pm_state)
1912 struct uart_port *port = state->uart_port;
1914 if (state->pm_state != pm_state) {
1916 port->ops->pm(port, pm_state, state->pm_state);
1917 state->pm_state = pm_state;
1922 struct uart_port *port;
1923 struct uart_driver *driver;
1926 static int serial_match_port(struct device *dev, void *data)
1928 struct uart_match *match = data;
1929 struct tty_driver *tty_drv = match->driver->tty_driver;
1930 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1933 return dev->devt == devt; /* Actually, only one tty per port */
1936 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1938 struct uart_state *state = drv->state + uport->line;
1939 struct tty_port *port = &state->port;
1940 struct device *tty_dev;
1941 struct uart_match match = {uport, drv};
1943 mutex_lock(&port->mutex);
1945 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1946 if (device_may_wakeup(tty_dev)) {
1947 if (!enable_irq_wake(uport->irq))
1948 uport->irq_wake = 1;
1949 put_device(tty_dev);
1950 mutex_unlock(&port->mutex);
1953 put_device(tty_dev);
1955 if (console_suspend_enabled || !uart_console(uport))
1956 uport->suspended = 1;
1958 if (port->flags & ASYNC_INITIALIZED) {
1959 const struct uart_ops *ops = uport->ops;
1962 if (console_suspend_enabled || !uart_console(uport)) {
1963 set_bit(ASYNCB_SUSPENDED, &port->flags);
1964 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1966 spin_lock_irq(&uport->lock);
1967 ops->stop_tx(uport);
1968 ops->set_mctrl(uport, 0);
1969 ops->stop_rx(uport);
1970 spin_unlock_irq(&uport->lock);
1974 * Wait for the transmitter to empty.
1976 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1979 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
1981 drv->tty_driver->name_base + uport->line);
1983 if (console_suspend_enabled || !uart_console(uport))
1984 ops->shutdown(uport);
1988 * Disable the console device before suspending.
1990 if (console_suspend_enabled && uart_console(uport))
1991 console_stop(uport->cons);
1993 if (console_suspend_enabled || !uart_console(uport))
1994 uart_change_pm(state, UART_PM_STATE_OFF);
1996 mutex_unlock(&port->mutex);
2001 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2003 struct uart_state *state = drv->state + uport->line;
2004 struct tty_port *port = &state->port;
2005 struct device *tty_dev;
2006 struct uart_match match = {uport, drv};
2007 struct ktermios termios;
2009 mutex_lock(&port->mutex);
2011 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2012 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2013 if (uport->irq_wake) {
2014 disable_irq_wake(uport->irq);
2015 uport->irq_wake = 0;
2017 put_device(tty_dev);
2018 mutex_unlock(&port->mutex);
2021 put_device(tty_dev);
2022 uport->suspended = 0;
2025 * Re-enable the console device after suspending.
2027 if (uart_console(uport)) {
2029 * First try to use the console cflag setting.
2031 memset(&termios, 0, sizeof(struct ktermios));
2032 termios.c_cflag = uport->cons->cflag;
2035 * If that's unset, use the tty termios setting.
2037 if (port->tty && termios.c_cflag == 0)
2038 termios = port->tty->termios;
2040 if (console_suspend_enabled)
2041 uart_change_pm(state, UART_PM_STATE_ON);
2042 uport->ops->set_termios(uport, &termios, NULL);
2043 if (console_suspend_enabled)
2044 console_start(uport->cons);
2047 if (port->flags & ASYNC_SUSPENDED) {
2048 const struct uart_ops *ops = uport->ops;
2051 uart_change_pm(state, UART_PM_STATE_ON);
2052 spin_lock_irq(&uport->lock);
2053 ops->set_mctrl(uport, 0);
2054 spin_unlock_irq(&uport->lock);
2055 if (console_suspend_enabled || !uart_console(uport)) {
2056 /* Protected by port mutex for now */
2057 struct tty_struct *tty = port->tty;
2058 ret = ops->startup(uport);
2061 uart_change_speed(tty, state, NULL);
2062 spin_lock_irq(&uport->lock);
2063 ops->set_mctrl(uport, uport->mctrl);
2064 ops->start_tx(uport);
2065 spin_unlock_irq(&uport->lock);
2066 set_bit(ASYNCB_INITIALIZED, &port->flags);
2069 * Failed to resume - maybe hardware went away?
2070 * Clear the "initialized" flag so we won't try
2071 * to call the low level drivers shutdown method.
2073 uart_shutdown(tty, state);
2077 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2080 mutex_unlock(&port->mutex);
2086 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2090 switch (port->iotype) {
2092 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2095 snprintf(address, sizeof(address),
2096 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2102 snprintf(address, sizeof(address),
2103 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2106 strlcpy(address, "*unknown*", sizeof(address));
2110 dev_info(port->dev, "%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2112 drv->tty_driver->name_base + port->line,
2113 address, port->irq, port->uartclk / 16, uart_type(port));
2117 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2118 struct uart_port *port)
2123 * If there isn't a port here, don't do anything further.
2125 if (!port->iobase && !port->mapbase && !port->membase)
2129 * Now do the auto configuration stuff. Note that config_port
2130 * is expected to claim the resources and map the port for us.
2133 if (port->flags & UPF_AUTO_IRQ)
2134 flags |= UART_CONFIG_IRQ;
2135 if (port->flags & UPF_BOOT_AUTOCONF) {
2136 if (!(port->flags & UPF_FIXED_TYPE)) {
2137 port->type = PORT_UNKNOWN;
2138 flags |= UART_CONFIG_TYPE;
2140 port->ops->config_port(port, flags);
2143 if (port->type != PORT_UNKNOWN) {
2144 unsigned long flags;
2146 uart_report_port(drv, port);
2148 /* Power up port for set_mctrl() */
2149 uart_change_pm(state, UART_PM_STATE_ON);
2152 * Ensure that the modem control lines are de-activated.
2153 * keep the DTR setting that is set in uart_set_options()
2154 * We probably don't need a spinlock around this, but
2156 spin_lock_irqsave(&port->lock, flags);
2157 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2158 spin_unlock_irqrestore(&port->lock, flags);
2161 * If this driver supports console, and it hasn't been
2162 * successfully registered yet, try to re-register it.
2163 * It may be that the port was not available.
2165 if (port->cons && !(port->cons->flags & CON_ENABLED))
2166 register_console(port->cons);
2169 * Power down all ports by default, except the
2170 * console if we have one.
2172 if (!uart_console(port))
2173 uart_change_pm(state, UART_PM_STATE_OFF);
2177 #ifdef CONFIG_CONSOLE_POLL
2179 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2181 struct uart_driver *drv = driver->driver_state;
2182 struct uart_state *state = drv->state + line;
2183 struct uart_port *port;
2190 if (!state || !state->uart_port)
2193 port = state->uart_port;
2194 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2197 if (port->ops->poll_init) {
2198 struct tty_port *tport = &state->port;
2201 mutex_lock(&tport->mutex);
2203 * We don't set ASYNCB_INITIALIZED as we only initialized the
2204 * hw, e.g. state->xmit is still uninitialized.
2206 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2207 ret = port->ops->poll_init(port);
2208 mutex_unlock(&tport->mutex);
2214 uart_parse_options(options, &baud, &parity, &bits, &flow);
2215 return uart_set_options(port, NULL, baud, parity, bits, flow);
2221 static int uart_poll_get_char(struct tty_driver *driver, int line)
2223 struct uart_driver *drv = driver->driver_state;
2224 struct uart_state *state = drv->state + line;
2225 struct uart_port *port;
2227 if (!state || !state->uart_port)
2230 port = state->uart_port;
2231 return port->ops->poll_get_char(port);
2234 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2236 struct uart_driver *drv = driver->driver_state;
2237 struct uart_state *state = drv->state + line;
2238 struct uart_port *port;
2240 if (!state || !state->uart_port)
2243 port = state->uart_port;
2246 port->ops->poll_put_char(port, '\r');
2247 port->ops->poll_put_char(port, ch);
2251 static const struct tty_operations uart_ops = {
2253 .close = uart_close,
2254 .write = uart_write,
2255 .put_char = uart_put_char,
2256 .flush_chars = uart_flush_chars,
2257 .write_room = uart_write_room,
2258 .chars_in_buffer= uart_chars_in_buffer,
2259 .flush_buffer = uart_flush_buffer,
2260 .ioctl = uart_ioctl,
2261 .throttle = uart_throttle,
2262 .unthrottle = uart_unthrottle,
2263 .send_xchar = uart_send_xchar,
2264 .set_termios = uart_set_termios,
2265 .set_ldisc = uart_set_ldisc,
2267 .start = uart_start,
2268 .hangup = uart_hangup,
2269 .break_ctl = uart_break_ctl,
2270 .wait_until_sent= uart_wait_until_sent,
2271 #ifdef CONFIG_PROC_FS
2272 .proc_fops = &uart_proc_fops,
2274 .tiocmget = uart_tiocmget,
2275 .tiocmset = uart_tiocmset,
2276 .get_icount = uart_get_icount,
2277 #ifdef CONFIG_CONSOLE_POLL
2278 .poll_init = uart_poll_init,
2279 .poll_get_char = uart_poll_get_char,
2280 .poll_put_char = uart_poll_put_char,
2284 static const struct tty_port_operations uart_port_ops = {
2285 .activate = uart_port_activate,
2286 .shutdown = uart_port_shutdown,
2287 .carrier_raised = uart_carrier_raised,
2288 .dtr_rts = uart_dtr_rts,
2292 * uart_register_driver - register a driver with the uart core layer
2293 * @drv: low level driver structure
2295 * Register a uart driver with the core driver. We in turn register
2296 * with the tty layer, and initialise the core driver per-port state.
2298 * We have a proc file in /proc/tty/driver which is named after the
2301 * drv->port should be NULL, and the per-port structures should be
2302 * registered using uart_add_one_port after this call has succeeded.
2304 int uart_register_driver(struct uart_driver *drv)
2306 struct tty_driver *normal;
2312 * Maybe we should be using a slab cache for this, especially if
2313 * we have a large number of ports to handle.
2315 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2319 normal = alloc_tty_driver(drv->nr);
2323 drv->tty_driver = normal;
2325 normal->driver_name = drv->driver_name;
2326 normal->name = drv->dev_name;
2327 normal->major = drv->major;
2328 normal->minor_start = drv->minor;
2329 normal->type = TTY_DRIVER_TYPE_SERIAL;
2330 normal->subtype = SERIAL_TYPE_NORMAL;
2331 normal->init_termios = tty_std_termios;
2332 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2333 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2334 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2335 normal->driver_state = drv;
2336 tty_set_operations(normal, &uart_ops);
2339 * Initialise the UART state(s).
2341 for (i = 0; i < drv->nr; i++) {
2342 struct uart_state *state = drv->state + i;
2343 struct tty_port *port = &state->port;
2345 tty_port_init(port);
2346 port->ops = &uart_port_ops;
2347 port->close_delay = HZ / 2; /* .5 seconds */
2348 port->closing_wait = 30 * HZ;/* 30 seconds */
2351 retval = tty_register_driver(normal);
2355 for (i = 0; i < drv->nr; i++)
2356 tty_port_destroy(&drv->state[i].port);
2357 put_tty_driver(normal);
2365 * uart_unregister_driver - remove a driver from the uart core layer
2366 * @drv: low level driver structure
2368 * Remove all references to a driver from the core driver. The low
2369 * level driver must have removed all its ports via the
2370 * uart_remove_one_port() if it registered them with uart_add_one_port().
2371 * (ie, drv->port == NULL)
2373 void uart_unregister_driver(struct uart_driver *drv)
2375 struct tty_driver *p = drv->tty_driver;
2378 tty_unregister_driver(p);
2380 for (i = 0; i < drv->nr; i++)
2381 tty_port_destroy(&drv->state[i].port);
2384 drv->tty_driver = NULL;
2387 struct tty_driver *uart_console_device(struct console *co, int *index)
2389 struct uart_driver *p = co->data;
2391 return p->tty_driver;
2394 static ssize_t uart_get_attr_uartclk(struct device *dev,
2395 struct device_attribute *attr, char *buf)
2397 struct serial_struct tmp;
2398 struct tty_port *port = dev_get_drvdata(dev);
2400 uart_get_info(port, &tmp);
2401 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2404 static ssize_t uart_get_attr_type(struct device *dev,
2405 struct device_attribute *attr, char *buf)
2407 struct serial_struct tmp;
2408 struct tty_port *port = dev_get_drvdata(dev);
2410 uart_get_info(port, &tmp);
2411 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2413 static ssize_t uart_get_attr_line(struct device *dev,
2414 struct device_attribute *attr, char *buf)
2416 struct serial_struct tmp;
2417 struct tty_port *port = dev_get_drvdata(dev);
2419 uart_get_info(port, &tmp);
2420 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2423 static ssize_t uart_get_attr_port(struct device *dev,
2424 struct device_attribute *attr, char *buf)
2426 struct serial_struct tmp;
2427 struct tty_port *port = dev_get_drvdata(dev);
2428 unsigned long ioaddr;
2430 uart_get_info(port, &tmp);
2432 if (HIGH_BITS_OFFSET)
2433 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2434 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2437 static ssize_t uart_get_attr_irq(struct device *dev,
2438 struct device_attribute *attr, char *buf)
2440 struct serial_struct tmp;
2441 struct tty_port *port = dev_get_drvdata(dev);
2443 uart_get_info(port, &tmp);
2444 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2447 static ssize_t uart_get_attr_flags(struct device *dev,
2448 struct device_attribute *attr, char *buf)
2450 struct serial_struct tmp;
2451 struct tty_port *port = dev_get_drvdata(dev);
2453 uart_get_info(port, &tmp);
2454 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2457 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2458 struct device_attribute *attr, char *buf)
2460 struct serial_struct tmp;
2461 struct tty_port *port = dev_get_drvdata(dev);
2463 uart_get_info(port, &tmp);
2464 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2468 static ssize_t uart_get_attr_close_delay(struct device *dev,
2469 struct device_attribute *attr, char *buf)
2471 struct serial_struct tmp;
2472 struct tty_port *port = dev_get_drvdata(dev);
2474 uart_get_info(port, &tmp);
2475 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2479 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2480 struct device_attribute *attr, char *buf)
2482 struct serial_struct tmp;
2483 struct tty_port *port = dev_get_drvdata(dev);
2485 uart_get_info(port, &tmp);
2486 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2489 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2490 struct device_attribute *attr, char *buf)
2492 struct serial_struct tmp;
2493 struct tty_port *port = dev_get_drvdata(dev);
2495 uart_get_info(port, &tmp);
2496 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2499 static ssize_t uart_get_attr_io_type(struct device *dev,
2500 struct device_attribute *attr, char *buf)
2502 struct serial_struct tmp;
2503 struct tty_port *port = dev_get_drvdata(dev);
2505 uart_get_info(port, &tmp);
2506 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2509 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2510 struct device_attribute *attr, char *buf)
2512 struct serial_struct tmp;
2513 struct tty_port *port = dev_get_drvdata(dev);
2515 uart_get_info(port, &tmp);
2516 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2519 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2520 struct device_attribute *attr, char *buf)
2522 struct serial_struct tmp;
2523 struct tty_port *port = dev_get_drvdata(dev);
2525 uart_get_info(port, &tmp);
2526 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2529 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2530 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2531 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2532 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2533 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2534 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2535 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2536 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2537 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2538 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2539 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2540 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2541 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2543 static struct attribute *tty_dev_attrs[] = {
2544 &dev_attr_type.attr,
2545 &dev_attr_line.attr,
2546 &dev_attr_port.attr,
2548 &dev_attr_flags.attr,
2549 &dev_attr_xmit_fifo_size.attr,
2550 &dev_attr_uartclk.attr,
2551 &dev_attr_close_delay.attr,
2552 &dev_attr_closing_wait.attr,
2553 &dev_attr_custom_divisor.attr,
2554 &dev_attr_io_type.attr,
2555 &dev_attr_iomem_base.attr,
2556 &dev_attr_iomem_reg_shift.attr,
2560 static const struct attribute_group tty_dev_attr_group = {
2561 .attrs = tty_dev_attrs,
2565 * uart_add_one_port - attach a driver-defined port structure
2566 * @drv: pointer to the uart low level driver structure for this port
2567 * @uport: uart port structure to use for this port.
2569 * This allows the driver to register its own uart_port structure
2570 * with the core driver. The main purpose is to allow the low
2571 * level uart drivers to expand uart_port, rather than having yet
2572 * more levels of structures.
2574 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2576 struct uart_state *state;
2577 struct tty_port *port;
2579 struct device *tty_dev;
2582 BUG_ON(in_interrupt());
2584 if (uport->line >= drv->nr)
2587 state = drv->state + uport->line;
2588 port = &state->port;
2590 mutex_lock(&port_mutex);
2591 mutex_lock(&port->mutex);
2592 if (state->uart_port) {
2597 state->uart_port = uport;
2598 state->pm_state = UART_PM_STATE_UNDEFINED;
2600 uport->cons = drv->cons;
2601 uport->state = state;
2604 * If this port is a console, then the spinlock is already
2607 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2608 spin_lock_init(&uport->lock);
2609 lockdep_set_class(&uport->lock, &port_lock_key);
2611 if (uport->cons && uport->dev)
2612 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2614 uart_configure_port(drv, state, uport);
2617 if (uport->attr_group)
2620 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2622 if (!uport->tty_groups) {
2626 uport->tty_groups[0] = &tty_dev_attr_group;
2627 if (uport->attr_group)
2628 uport->tty_groups[1] = uport->attr_group;
2631 * Register the port whether it's detected or not. This allows
2632 * setserial to be used to alter this port's parameters.
2634 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2635 uport->line, uport->dev, port, uport->tty_groups);
2636 if (likely(!IS_ERR(tty_dev))) {
2637 device_set_wakeup_capable(tty_dev, 1);
2639 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2644 * Ensure UPF_DEAD is not set.
2646 uport->flags &= ~UPF_DEAD;
2649 mutex_unlock(&port->mutex);
2650 mutex_unlock(&port_mutex);
2656 * uart_remove_one_port - detach a driver defined port structure
2657 * @drv: pointer to the uart low level driver structure for this port
2658 * @uport: uart port structure for this port
2660 * This unhooks (and hangs up) the specified port structure from the
2661 * core driver. No further calls will be made to the low-level code
2664 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2666 struct uart_state *state = drv->state + uport->line;
2667 struct tty_port *port = &state->port;
2668 struct tty_struct *tty;
2671 BUG_ON(in_interrupt());
2673 if (state->uart_port != uport)
2674 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2675 state->uart_port, uport);
2677 mutex_lock(&port_mutex);
2680 * Mark the port "dead" - this prevents any opens from
2681 * succeeding while we shut down the port.
2683 mutex_lock(&port->mutex);
2684 if (!state->uart_port) {
2685 mutex_unlock(&port->mutex);
2689 uport->flags |= UPF_DEAD;
2690 mutex_unlock(&port->mutex);
2693 * Remove the devices from the tty layer
2695 tty_unregister_device(drv->tty_driver, uport->line);
2697 tty = tty_port_tty_get(port);
2699 tty_vhangup(port->tty);
2704 * If the port is used as a console, unregister it
2706 if (uart_console(uport))
2707 unregister_console(uport->cons);
2710 * Free the port IO and memory resources, if any.
2712 if (uport->type != PORT_UNKNOWN)
2713 uport->ops->release_port(uport);
2714 kfree(uport->tty_groups);
2717 * Indicate that there isn't a port here anymore.
2719 uport->type = PORT_UNKNOWN;
2721 state->uart_port = NULL;
2723 mutex_unlock(&port_mutex);
2729 * Are the two ports equivalent?
2731 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2733 if (port1->iotype != port2->iotype)
2736 switch (port1->iotype) {
2738 return (port1->iobase == port2->iobase);
2740 return (port1->iobase == port2->iobase) &&
2741 (port1->hub6 == port2->hub6);
2746 return (port1->mapbase == port2->mapbase);
2750 EXPORT_SYMBOL(uart_match_port);
2753 * uart_handle_dcd_change - handle a change of carrier detect state
2754 * @uport: uart_port structure for the open port
2755 * @status: new carrier detect status, nonzero if active
2757 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2759 struct tty_port *port = &uport->state->port;
2760 struct tty_struct *tty = port->tty;
2761 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2764 if (ld->ops->dcd_change)
2765 ld->ops->dcd_change(tty, status);
2766 tty_ldisc_deref(ld);
2769 uport->icount.dcd++;
2771 if (port->flags & ASYNC_CHECK_CD) {
2773 wake_up_interruptible(&port->open_wait);
2778 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2781 * uart_handle_cts_change - handle a change of clear-to-send state
2782 * @uport: uart_port structure for the open port
2783 * @status: new clear to send status, nonzero if active
2785 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2787 struct tty_port *port = &uport->state->port;
2788 struct tty_struct *tty = port->tty;
2790 uport->icount.cts++;
2792 /* skip below code if the hw flow control is supported */
2793 if (tty_port_cts_enabled(port) &&
2794 !(uport->flags & UPF_HARD_FLOW)) {
2795 if (tty->hw_stopped) {
2797 tty->hw_stopped = 0;
2798 uport->ops->start_tx(uport);
2799 uart_write_wakeup(uport);
2803 tty->hw_stopped = 1;
2804 uport->ops->stop_tx(uport);
2809 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2812 * uart_insert_char - push a char to the uart layer
2814 * User is responsible to call tty_flip_buffer_push when they are done with
2817 * @port: corresponding port
2818 * @status: state of the serial port RX buffer (LSR for 8250)
2819 * @overrun: mask of overrun bits in @status
2820 * @ch: character to push
2821 * @flag: flag for the character (see TTY_NORMAL and friends)
2823 void uart_insert_char(struct uart_port *port, unsigned int status,
2824 unsigned int overrun, unsigned int ch, unsigned int flag)
2826 struct tty_port *tport = &port->state->port;
2828 if ((status & port->ignore_status_mask & ~overrun) == 0)
2829 if (tty_insert_flip_char(tport, ch, flag) == 0)
2830 ++port->icount.buf_overrun;
2833 * Overrun is special. Since it's reported immediately,
2834 * it doesn't affect the current character.
2836 if (status & ~port->ignore_status_mask & overrun)
2837 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2838 ++port->icount.buf_overrun;
2840 EXPORT_SYMBOL_GPL(uart_insert_char);
2842 EXPORT_SYMBOL(uart_write_wakeup);
2843 EXPORT_SYMBOL(uart_register_driver);
2844 EXPORT_SYMBOL(uart_unregister_driver);
2845 EXPORT_SYMBOL(uart_suspend_port);
2846 EXPORT_SYMBOL(uart_resume_port);
2847 EXPORT_SYMBOL(uart_add_one_port);
2848 EXPORT_SYMBOL(uart_remove_one_port);
2850 MODULE_DESCRIPTION("Serial driver core");
2851 MODULE_LICENSE("GPL");