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 "%s sets custom speed on %s. This "
897 "is deprecated.\n", current->comm,
898 tty_name(port->tty, buf));
900 uart_change_speed(tty, state, NULL);
903 retval = uart_startup(tty, state, 1);
908 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
909 struct serial_struct __user *newinfo)
911 struct serial_struct new_serial;
912 struct tty_port *port = &state->port;
915 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
919 * This semaphore protects port->count. It is also
920 * very useful to prevent opens. Also, take the
921 * port configuration semaphore to make sure that a
922 * module insertion/removal doesn't change anything
925 mutex_lock(&port->mutex);
926 retval = uart_set_info(tty, port, state, &new_serial);
927 mutex_unlock(&port->mutex);
932 * uart_get_lsr_info - get line status register info
933 * @tty: tty associated with the UART
934 * @state: UART being queried
935 * @value: returned modem value
937 * Note: uart_ioctl protects us against hangups.
939 static int uart_get_lsr_info(struct tty_struct *tty,
940 struct uart_state *state, unsigned int __user *value)
942 struct uart_port *uport = state->uart_port;
945 result = uport->ops->tx_empty(uport);
948 * If we're about to load something into the transmit
949 * register, we'll pretend the transmitter isn't empty to
950 * avoid a race condition (depending on when the transmit
951 * interrupt happens).
954 ((uart_circ_chars_pending(&state->xmit) > 0) &&
955 !tty->stopped && !tty->hw_stopped))
956 result &= ~TIOCSER_TEMT;
958 return put_user(result, value);
961 static int uart_tiocmget(struct tty_struct *tty)
963 struct uart_state *state = tty->driver_data;
964 struct tty_port *port = &state->port;
965 struct uart_port *uport = state->uart_port;
968 mutex_lock(&port->mutex);
969 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
970 result = uport->mctrl;
971 spin_lock_irq(&uport->lock);
972 result |= uport->ops->get_mctrl(uport);
973 spin_unlock_irq(&uport->lock);
975 mutex_unlock(&port->mutex);
981 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
983 struct uart_state *state = tty->driver_data;
984 struct uart_port *uport = state->uart_port;
985 struct tty_port *port = &state->port;
988 mutex_lock(&port->mutex);
989 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
990 uart_update_mctrl(uport, set, clear);
993 mutex_unlock(&port->mutex);
997 static int uart_break_ctl(struct tty_struct *tty, int break_state)
999 struct uart_state *state = tty->driver_data;
1000 struct tty_port *port = &state->port;
1001 struct uart_port *uport = state->uart_port;
1003 mutex_lock(&port->mutex);
1005 if (uport->type != PORT_UNKNOWN)
1006 uport->ops->break_ctl(uport, break_state);
1008 mutex_unlock(&port->mutex);
1012 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1014 struct uart_port *uport = state->uart_port;
1015 struct tty_port *port = &state->port;
1018 if (!capable(CAP_SYS_ADMIN))
1022 * Take the per-port semaphore. This prevents count from
1023 * changing, and hence any extra opens of the port while
1024 * we're auto-configuring.
1026 if (mutex_lock_interruptible(&port->mutex))
1027 return -ERESTARTSYS;
1030 if (tty_port_users(port) == 1) {
1031 uart_shutdown(tty, state);
1034 * If we already have a port type configured,
1035 * we must release its resources.
1037 if (uport->type != PORT_UNKNOWN)
1038 uport->ops->release_port(uport);
1040 flags = UART_CONFIG_TYPE;
1041 if (uport->flags & UPF_AUTO_IRQ)
1042 flags |= UART_CONFIG_IRQ;
1045 * This will claim the ports resources if
1048 uport->ops->config_port(uport, flags);
1050 ret = uart_startup(tty, state, 1);
1052 mutex_unlock(&port->mutex);
1056 static void uart_enable_ms(struct uart_port *uport)
1059 * Force modem status interrupts on
1061 if (uport->ops->enable_ms)
1062 uport->ops->enable_ms(uport);
1066 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1067 * - mask passed in arg for lines of interest
1068 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1069 * Caller should use TIOCGICOUNT to see which one it was
1071 * FIXME: This wants extracting into a common all driver implementation
1072 * of TIOCMWAIT using tty_port.
1075 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1077 struct uart_port *uport = state->uart_port;
1078 struct tty_port *port = &state->port;
1079 DECLARE_WAITQUEUE(wait, current);
1080 struct uart_icount cprev, cnow;
1084 * note the counters on entry
1086 spin_lock_irq(&uport->lock);
1087 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1088 uart_enable_ms(uport);
1089 spin_unlock_irq(&uport->lock);
1091 add_wait_queue(&port->delta_msr_wait, &wait);
1093 spin_lock_irq(&uport->lock);
1094 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1095 spin_unlock_irq(&uport->lock);
1097 set_current_state(TASK_INTERRUPTIBLE);
1099 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1100 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1101 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1102 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1109 /* see if a signal did it */
1110 if (signal_pending(current)) {
1118 current->state = TASK_RUNNING;
1119 remove_wait_queue(&port->delta_msr_wait, &wait);
1125 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1126 * Return: write counters to the user passed counter struct
1127 * NB: both 1->0 and 0->1 transitions are counted except for
1128 * RI where only 0->1 is counted.
1130 static int uart_get_icount(struct tty_struct *tty,
1131 struct serial_icounter_struct *icount)
1133 struct uart_state *state = tty->driver_data;
1134 struct uart_icount cnow;
1135 struct uart_port *uport = state->uart_port;
1137 spin_lock_irq(&uport->lock);
1138 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1139 spin_unlock_irq(&uport->lock);
1141 icount->cts = cnow.cts;
1142 icount->dsr = cnow.dsr;
1143 icount->rng = cnow.rng;
1144 icount->dcd = cnow.dcd;
1145 icount->rx = cnow.rx;
1146 icount->tx = cnow.tx;
1147 icount->frame = cnow.frame;
1148 icount->overrun = cnow.overrun;
1149 icount->parity = cnow.parity;
1150 icount->brk = cnow.brk;
1151 icount->buf_overrun = cnow.buf_overrun;
1157 * Called via sys_ioctl. We can use spin_lock_irq() here.
1160 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1163 struct uart_state *state = tty->driver_data;
1164 struct tty_port *port = &state->port;
1165 void __user *uarg = (void __user *)arg;
1166 int ret = -ENOIOCTLCMD;
1170 * These ioctls don't rely on the hardware to be present.
1174 ret = uart_get_info_user(port, uarg);
1178 ret = uart_set_info_user(tty, state, uarg);
1182 ret = uart_do_autoconfig(tty, state);
1185 case TIOCSERGWILD: /* obsolete */
1186 case TIOCSERSWILD: /* obsolete */
1191 if (ret != -ENOIOCTLCMD)
1194 if (tty->flags & (1 << TTY_IO_ERROR)) {
1200 * The following should only be used when hardware is present.
1204 ret = uart_wait_modem_status(state, arg);
1208 if (ret != -ENOIOCTLCMD)
1211 mutex_lock(&port->mutex);
1213 if (tty->flags & (1 << TTY_IO_ERROR)) {
1219 * All these rely on hardware being present and need to be
1220 * protected against the tty being hung up.
1223 case TIOCSERGETLSR: /* Get line status register */
1224 ret = uart_get_lsr_info(tty, state, uarg);
1228 struct uart_port *uport = state->uart_port;
1229 if (uport->ops->ioctl)
1230 ret = uport->ops->ioctl(uport, cmd, arg);
1235 mutex_unlock(&port->mutex);
1240 static void uart_set_ldisc(struct tty_struct *tty)
1242 struct uart_state *state = tty->driver_data;
1243 struct uart_port *uport = state->uart_port;
1245 if (uport->ops->set_ldisc)
1246 uport->ops->set_ldisc(uport, tty->termios.c_line);
1249 static void uart_set_termios(struct tty_struct *tty,
1250 struct ktermios *old_termios)
1252 struct uart_state *state = tty->driver_data;
1253 struct uart_port *uport = state->uart_port;
1254 unsigned long flags;
1255 unsigned int cflag = tty->termios.c_cflag;
1256 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1257 bool sw_changed = false;
1260 * Drivers doing software flow control also need to know
1261 * about changes to these input settings.
1263 if (uport->flags & UPF_SOFT_FLOW) {
1264 iflag_mask |= IXANY|IXON|IXOFF;
1266 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1267 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1271 * These are the bits that are used to setup various
1272 * flags in the low level driver. We can ignore the Bfoo
1273 * bits in c_cflag; c_[io]speed will always be set
1274 * appropriately by set_termios() in tty_ioctl.c
1276 if ((cflag ^ old_termios->c_cflag) == 0 &&
1277 tty->termios.c_ospeed == old_termios->c_ospeed &&
1278 tty->termios.c_ispeed == old_termios->c_ispeed &&
1279 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1284 uart_change_speed(tty, state, old_termios);
1285 /* reload cflag from termios; port driver may have overriden flags */
1286 cflag = tty->termios.c_cflag;
1288 /* Handle transition to B0 status */
1289 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1290 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1291 /* Handle transition away from B0 status */
1292 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1293 unsigned int mask = TIOCM_DTR;
1294 if (!(cflag & CRTSCTS) ||
1295 !test_bit(TTY_THROTTLED, &tty->flags))
1297 uart_set_mctrl(uport, mask);
1301 * If the port is doing h/w assisted flow control, do nothing.
1302 * We assume that tty->hw_stopped has never been set.
1304 if (uport->flags & UPF_HARD_FLOW)
1307 /* Handle turning off CRTSCTS */
1308 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1309 spin_lock_irqsave(&uport->lock, flags);
1310 tty->hw_stopped = 0;
1312 spin_unlock_irqrestore(&uport->lock, flags);
1314 /* Handle turning on CRTSCTS */
1315 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1316 spin_lock_irqsave(&uport->lock, flags);
1317 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1318 tty->hw_stopped = 1;
1319 uport->ops->stop_tx(uport);
1321 spin_unlock_irqrestore(&uport->lock, flags);
1326 * Calls to uart_close() are serialised via the tty_lock in
1327 * drivers/tty/tty_io.c:tty_release()
1328 * drivers/tty/tty_io.c:do_tty_hangup()
1329 * This runs from a workqueue and can sleep for a _short_ time only.
1331 static void uart_close(struct tty_struct *tty, struct file *filp)
1333 struct uart_state *state = tty->driver_data;
1334 struct tty_port *port;
1335 struct uart_port *uport;
1336 unsigned long flags;
1341 uport = state->uart_port;
1342 port = &state->port;
1344 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1346 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1350 * At this point, we stop accepting input. To do this, we
1351 * disable the receive line status interrupts.
1353 if (port->flags & ASYNC_INITIALIZED) {
1354 unsigned long flags;
1355 spin_lock_irqsave(&uport->lock, flags);
1356 uport->ops->stop_rx(uport);
1357 spin_unlock_irqrestore(&uport->lock, flags);
1359 * Before we drop DTR, make sure the UART transmitter
1360 * has completely drained; this is especially
1361 * important if there is a transmit FIFO!
1363 uart_wait_until_sent(tty, uport->timeout);
1366 mutex_lock(&port->mutex);
1367 uart_shutdown(tty, state);
1368 uart_flush_buffer(tty);
1370 tty_ldisc_flush(tty);
1372 tty_port_tty_set(port, NULL);
1374 spin_lock_irqsave(&port->lock, flags);
1376 if (port->blocked_open) {
1377 spin_unlock_irqrestore(&port->lock, flags);
1378 if (port->close_delay)
1379 msleep_interruptible(
1380 jiffies_to_msecs(port->close_delay));
1381 spin_lock_irqsave(&port->lock, flags);
1382 } else if (!uart_console(uport)) {
1383 spin_unlock_irqrestore(&port->lock, flags);
1384 uart_change_pm(state, UART_PM_STATE_OFF);
1385 spin_lock_irqsave(&port->lock, flags);
1389 * Wake up anyone trying to open this port.
1391 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1392 clear_bit(ASYNCB_CLOSING, &port->flags);
1393 spin_unlock_irqrestore(&port->lock, flags);
1394 wake_up_interruptible(&port->open_wait);
1395 wake_up_interruptible(&port->close_wait);
1397 mutex_unlock(&port->mutex);
1400 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1402 struct uart_state *state = tty->driver_data;
1403 struct uart_port *port = state->uart_port;
1404 unsigned long char_time, expire;
1406 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1410 * Set the check interval to be 1/5 of the estimated time to
1411 * send a single character, and make it at least 1. The check
1412 * interval should also be less than the timeout.
1414 * Note: we have to use pretty tight timings here to satisfy
1417 char_time = (port->timeout - HZ/50) / port->fifosize;
1418 char_time = char_time / 5;
1421 if (timeout && timeout < char_time)
1422 char_time = timeout;
1425 * If the transmitter hasn't cleared in twice the approximate
1426 * amount of time to send the entire FIFO, it probably won't
1427 * ever clear. This assumes the UART isn't doing flow
1428 * control, which is currently the case. Hence, if it ever
1429 * takes longer than port->timeout, this is probably due to a
1430 * UART bug of some kind. So, we clamp the timeout parameter at
1433 if (timeout == 0 || timeout > 2 * port->timeout)
1434 timeout = 2 * port->timeout;
1436 expire = jiffies + timeout;
1438 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1439 port->line, jiffies, expire);
1442 * Check whether the transmitter is empty every 'char_time'.
1443 * 'timeout' / 'expire' give us the maximum amount of time
1446 while (!port->ops->tx_empty(port)) {
1447 msleep_interruptible(jiffies_to_msecs(char_time));
1448 if (signal_pending(current))
1450 if (time_after(jiffies, expire))
1456 * Calls to uart_hangup() are serialised by the tty_lock in
1457 * drivers/tty/tty_io.c:do_tty_hangup()
1458 * This runs from a workqueue and can sleep for a _short_ time only.
1460 static void uart_hangup(struct tty_struct *tty)
1462 struct uart_state *state = tty->driver_data;
1463 struct tty_port *port = &state->port;
1464 unsigned long flags;
1466 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1468 mutex_lock(&port->mutex);
1469 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1470 uart_flush_buffer(tty);
1471 uart_shutdown(tty, state);
1472 spin_lock_irqsave(&port->lock, flags);
1474 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1475 spin_unlock_irqrestore(&port->lock, flags);
1476 tty_port_tty_set(port, NULL);
1477 if (!uart_console(state->uart_port))
1478 uart_change_pm(state, UART_PM_STATE_OFF);
1479 wake_up_interruptible(&port->open_wait);
1480 wake_up_interruptible(&port->delta_msr_wait);
1482 mutex_unlock(&port->mutex);
1485 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1490 static void uart_port_shutdown(struct tty_port *port)
1492 struct uart_state *state = container_of(port, struct uart_state, port);
1493 struct uart_port *uport = state->uart_port;
1496 * clear delta_msr_wait queue to avoid mem leaks: we may free
1497 * the irq here so the queue might never be woken up. Note
1498 * that we won't end up waiting on delta_msr_wait again since
1499 * any outstanding file descriptors should be pointing at
1500 * hung_up_tty_fops now.
1502 wake_up_interruptible(&port->delta_msr_wait);
1505 * Free the IRQ and disable the port.
1507 uport->ops->shutdown(uport);
1510 * Ensure that the IRQ handler isn't running on another CPU.
1512 synchronize_irq(uport->irq);
1515 static int uart_carrier_raised(struct tty_port *port)
1517 struct uart_state *state = container_of(port, struct uart_state, port);
1518 struct uart_port *uport = state->uart_port;
1520 spin_lock_irq(&uport->lock);
1521 uart_enable_ms(uport);
1522 mctrl = uport->ops->get_mctrl(uport);
1523 spin_unlock_irq(&uport->lock);
1524 if (mctrl & TIOCM_CAR)
1529 static void uart_dtr_rts(struct tty_port *port, int onoff)
1531 struct uart_state *state = container_of(port, struct uart_state, port);
1532 struct uart_port *uport = state->uart_port;
1535 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1537 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1541 * Calls to uart_open are serialised by the tty_lock in
1542 * drivers/tty/tty_io.c:tty_open()
1543 * Note that if this fails, then uart_close() _will_ be called.
1545 * In time, we want to scrap the "opening nonpresent ports"
1546 * behaviour and implement an alternative way for setserial
1547 * to set base addresses/ports/types. This will allow us to
1548 * get rid of a certain amount of extra tests.
1550 static int uart_open(struct tty_struct *tty, struct file *filp)
1552 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1553 int retval, line = tty->index;
1554 struct uart_state *state = drv->state + line;
1555 struct tty_port *port = &state->port;
1557 pr_debug("uart_open(%d) called\n", line);
1560 * We take the semaphore here to guarantee that we won't be re-entered
1561 * while allocating the state structure, or while we request any IRQs
1562 * that the driver may need. This also has the nice side-effect that
1563 * it delays the action of uart_hangup, so we can guarantee that
1564 * state->port.tty will always contain something reasonable.
1566 if (mutex_lock_interruptible(&port->mutex)) {
1567 retval = -ERESTARTSYS;
1572 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1578 * Once we set tty->driver_data here, we are guaranteed that
1579 * uart_close() will decrement the driver module use count.
1580 * Any failures from here onwards should not touch the count.
1582 tty->driver_data = state;
1583 state->uart_port->state = state;
1584 state->port.low_latency =
1585 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1586 tty_port_tty_set(port, tty);
1589 * Start up the serial port.
1591 retval = uart_startup(tty, state, 0);
1594 * If we succeeded, wait until the port is ready.
1596 mutex_unlock(&port->mutex);
1598 retval = tty_port_block_til_ready(port, tty, filp);
1604 mutex_unlock(&port->mutex);
1608 static const char *uart_type(struct uart_port *port)
1610 const char *str = NULL;
1612 if (port->ops->type)
1613 str = port->ops->type(port);
1621 #ifdef CONFIG_PROC_FS
1623 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1625 struct uart_state *state = drv->state + i;
1626 struct tty_port *port = &state->port;
1627 enum uart_pm_state pm_state;
1628 struct uart_port *uport = state->uart_port;
1630 unsigned int status;
1636 mmio = uport->iotype >= UPIO_MEM;
1637 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1638 uport->line, uart_type(uport),
1639 mmio ? "mmio:0x" : "port:",
1640 mmio ? (unsigned long long)uport->mapbase
1641 : (unsigned long long)uport->iobase,
1644 if (uport->type == PORT_UNKNOWN) {
1649 if (capable(CAP_SYS_ADMIN)) {
1650 mutex_lock(&port->mutex);
1651 pm_state = state->pm_state;
1652 if (pm_state != UART_PM_STATE_ON)
1653 uart_change_pm(state, UART_PM_STATE_ON);
1654 spin_lock_irq(&uport->lock);
1655 status = uport->ops->get_mctrl(uport);
1656 spin_unlock_irq(&uport->lock);
1657 if (pm_state != UART_PM_STATE_ON)
1658 uart_change_pm(state, pm_state);
1659 mutex_unlock(&port->mutex);
1661 seq_printf(m, " tx:%d rx:%d",
1662 uport->icount.tx, uport->icount.rx);
1663 if (uport->icount.frame)
1664 seq_printf(m, " fe:%d",
1665 uport->icount.frame);
1666 if (uport->icount.parity)
1667 seq_printf(m, " pe:%d",
1668 uport->icount.parity);
1669 if (uport->icount.brk)
1670 seq_printf(m, " brk:%d",
1672 if (uport->icount.overrun)
1673 seq_printf(m, " oe:%d",
1674 uport->icount.overrun);
1676 #define INFOBIT(bit, str) \
1677 if (uport->mctrl & (bit)) \
1678 strncat(stat_buf, (str), sizeof(stat_buf) - \
1679 strlen(stat_buf) - 2)
1680 #define STATBIT(bit, str) \
1681 if (status & (bit)) \
1682 strncat(stat_buf, (str), sizeof(stat_buf) - \
1683 strlen(stat_buf) - 2)
1687 INFOBIT(TIOCM_RTS, "|RTS");
1688 STATBIT(TIOCM_CTS, "|CTS");
1689 INFOBIT(TIOCM_DTR, "|DTR");
1690 STATBIT(TIOCM_DSR, "|DSR");
1691 STATBIT(TIOCM_CAR, "|CD");
1692 STATBIT(TIOCM_RNG, "|RI");
1696 seq_puts(m, stat_buf);
1703 static int uart_proc_show(struct seq_file *m, void *v)
1705 struct tty_driver *ttydrv = m->private;
1706 struct uart_driver *drv = ttydrv->driver_state;
1709 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1711 for (i = 0; i < drv->nr; i++)
1712 uart_line_info(m, drv, i);
1716 static int uart_proc_open(struct inode *inode, struct file *file)
1718 return single_open(file, uart_proc_show, PDE_DATA(inode));
1721 static const struct file_operations uart_proc_fops = {
1722 .owner = THIS_MODULE,
1723 .open = uart_proc_open,
1725 .llseek = seq_lseek,
1726 .release = single_release,
1730 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1732 * uart_console_write - write a console message to a serial port
1733 * @port: the port to write the message
1734 * @s: array of characters
1735 * @count: number of characters in string to write
1736 * @write: function to write character to port
1738 void uart_console_write(struct uart_port *port, const char *s,
1740 void (*putchar)(struct uart_port *, int))
1744 for (i = 0; i < count; i++, s++) {
1746 putchar(port, '\r');
1750 EXPORT_SYMBOL_GPL(uart_console_write);
1753 * Check whether an invalid uart number has been specified, and
1754 * if so, search for the first available port that does have
1757 struct uart_port * __init
1758 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1760 int idx = co->index;
1762 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1763 ports[idx].membase == NULL))
1764 for (idx = 0; idx < nr; idx++)
1765 if (ports[idx].iobase != 0 ||
1766 ports[idx].membase != NULL)
1775 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1776 * @options: pointer to option string
1777 * @baud: pointer to an 'int' variable for the baud rate.
1778 * @parity: pointer to an 'int' variable for the parity.
1779 * @bits: pointer to an 'int' variable for the number of data bits.
1780 * @flow: pointer to an 'int' variable for the flow control character.
1782 * uart_parse_options decodes a string containing the serial console
1783 * options. The format of the string is <baud><parity><bits><flow>,
1787 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1791 *baud = simple_strtoul(s, NULL, 10);
1792 while (*s >= '0' && *s <= '9')
1801 EXPORT_SYMBOL_GPL(uart_parse_options);
1808 static const struct baud_rates baud_rates[] = {
1809 { 921600, B921600 },
1810 { 460800, B460800 },
1811 { 230400, B230400 },
1812 { 115200, B115200 },
1824 * uart_set_options - setup the serial console parameters
1825 * @port: pointer to the serial ports uart_port structure
1826 * @co: console pointer
1828 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1829 * @bits: number of data bits
1830 * @flow: flow control character - 'r' (rts)
1833 uart_set_options(struct uart_port *port, struct console *co,
1834 int baud, int parity, int bits, int flow)
1836 struct ktermios termios;
1837 static struct ktermios dummy;
1841 * Ensure that the serial console lock is initialised
1843 * If this port is a console, then the spinlock is already
1846 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1847 spin_lock_init(&port->lock);
1848 lockdep_set_class(&port->lock, &port_lock_key);
1851 memset(&termios, 0, sizeof(struct ktermios));
1853 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1856 * Construct a cflag setting.
1858 for (i = 0; baud_rates[i].rate; i++)
1859 if (baud_rates[i].rate <= baud)
1862 termios.c_cflag |= baud_rates[i].cflag;
1865 termios.c_cflag |= CS7;
1867 termios.c_cflag |= CS8;
1871 termios.c_cflag |= PARODD;
1874 termios.c_cflag |= PARENB;
1879 termios.c_cflag |= CRTSCTS;
1882 * some uarts on other side don't support no flow control.
1883 * So we set * DTR in host uart to make them happy
1885 port->mctrl |= TIOCM_DTR;
1887 port->ops->set_termios(port, &termios, &dummy);
1889 * Allow the setting of the UART parameters with a NULL console
1893 co->cflag = termios.c_cflag;
1897 EXPORT_SYMBOL_GPL(uart_set_options);
1898 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1901 * uart_change_pm - set power state of the port
1903 * @state: port descriptor
1904 * @pm_state: new state
1906 * Locking: port->mutex has to be held
1908 static void uart_change_pm(struct uart_state *state,
1909 enum uart_pm_state pm_state)
1911 struct uart_port *port = state->uart_port;
1913 if (state->pm_state != pm_state) {
1915 port->ops->pm(port, pm_state, state->pm_state);
1916 state->pm_state = pm_state;
1921 struct uart_port *port;
1922 struct uart_driver *driver;
1925 static int serial_match_port(struct device *dev, void *data)
1927 struct uart_match *match = data;
1928 struct tty_driver *tty_drv = match->driver->tty_driver;
1929 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1932 return dev->devt == devt; /* Actually, only one tty per port */
1935 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1937 struct uart_state *state = drv->state + uport->line;
1938 struct tty_port *port = &state->port;
1939 struct device *tty_dev;
1940 struct uart_match match = {uport, drv};
1942 mutex_lock(&port->mutex);
1944 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1945 if (device_may_wakeup(tty_dev)) {
1946 if (!enable_irq_wake(uport->irq))
1947 uport->irq_wake = 1;
1948 put_device(tty_dev);
1949 mutex_unlock(&port->mutex);
1952 put_device(tty_dev);
1954 if (console_suspend_enabled || !uart_console(uport))
1955 uport->suspended = 1;
1957 if (port->flags & ASYNC_INITIALIZED) {
1958 const struct uart_ops *ops = uport->ops;
1961 if (console_suspend_enabled || !uart_console(uport)) {
1962 set_bit(ASYNCB_SUSPENDED, &port->flags);
1963 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1965 spin_lock_irq(&uport->lock);
1966 ops->stop_tx(uport);
1967 ops->set_mctrl(uport, 0);
1968 ops->stop_rx(uport);
1969 spin_unlock_irq(&uport->lock);
1973 * Wait for the transmitter to empty.
1975 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1978 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1980 uport->dev ? dev_name(uport->dev) : "",
1981 uport->dev ? ": " : "",
1983 drv->tty_driver->name_base + uport->line);
1985 if (console_suspend_enabled || !uart_console(uport))
1986 ops->shutdown(uport);
1990 * Disable the console device before suspending.
1992 if (console_suspend_enabled && uart_console(uport))
1993 console_stop(uport->cons);
1995 if (console_suspend_enabled || !uart_console(uport))
1996 uart_change_pm(state, UART_PM_STATE_OFF);
1998 mutex_unlock(&port->mutex);
2003 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2005 struct uart_state *state = drv->state + uport->line;
2006 struct tty_port *port = &state->port;
2007 struct device *tty_dev;
2008 struct uart_match match = {uport, drv};
2009 struct ktermios termios;
2011 mutex_lock(&port->mutex);
2013 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2014 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2015 if (uport->irq_wake) {
2016 disable_irq_wake(uport->irq);
2017 uport->irq_wake = 0;
2019 put_device(tty_dev);
2020 mutex_unlock(&port->mutex);
2023 put_device(tty_dev);
2024 uport->suspended = 0;
2027 * Re-enable the console device after suspending.
2029 if (uart_console(uport)) {
2031 * First try to use the console cflag setting.
2033 memset(&termios, 0, sizeof(struct ktermios));
2034 termios.c_cflag = uport->cons->cflag;
2037 * If that's unset, use the tty termios setting.
2039 if (port->tty && termios.c_cflag == 0)
2040 termios = port->tty->termios;
2042 if (console_suspend_enabled)
2043 uart_change_pm(state, UART_PM_STATE_ON);
2044 uport->ops->set_termios(uport, &termios, NULL);
2045 if (console_suspend_enabled)
2046 console_start(uport->cons);
2049 if (port->flags & ASYNC_SUSPENDED) {
2050 const struct uart_ops *ops = uport->ops;
2053 uart_change_pm(state, UART_PM_STATE_ON);
2054 spin_lock_irq(&uport->lock);
2055 ops->set_mctrl(uport, 0);
2056 spin_unlock_irq(&uport->lock);
2057 if (console_suspend_enabled || !uart_console(uport)) {
2058 /* Protected by port mutex for now */
2059 struct tty_struct *tty = port->tty;
2060 ret = ops->startup(uport);
2063 uart_change_speed(tty, state, NULL);
2064 spin_lock_irq(&uport->lock);
2065 ops->set_mctrl(uport, uport->mctrl);
2066 ops->start_tx(uport);
2067 spin_unlock_irq(&uport->lock);
2068 set_bit(ASYNCB_INITIALIZED, &port->flags);
2071 * Failed to resume - maybe hardware went away?
2072 * Clear the "initialized" flag so we won't try
2073 * to call the low level drivers shutdown method.
2075 uart_shutdown(tty, state);
2079 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2082 mutex_unlock(&port->mutex);
2088 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2092 switch (port->iotype) {
2094 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2097 snprintf(address, sizeof(address),
2098 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2104 snprintf(address, sizeof(address),
2105 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2108 strlcpy(address, "*unknown*", sizeof(address));
2112 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2113 port->dev ? dev_name(port->dev) : "",
2114 port->dev ? ": " : "",
2116 drv->tty_driver->name_base + port->line,
2117 address, port->irq, port->uartclk / 16, uart_type(port));
2121 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2122 struct uart_port *port)
2127 * If there isn't a port here, don't do anything further.
2129 if (!port->iobase && !port->mapbase && !port->membase)
2133 * Now do the auto configuration stuff. Note that config_port
2134 * is expected to claim the resources and map the port for us.
2137 if (port->flags & UPF_AUTO_IRQ)
2138 flags |= UART_CONFIG_IRQ;
2139 if (port->flags & UPF_BOOT_AUTOCONF) {
2140 if (!(port->flags & UPF_FIXED_TYPE)) {
2141 port->type = PORT_UNKNOWN;
2142 flags |= UART_CONFIG_TYPE;
2144 port->ops->config_port(port, flags);
2147 if (port->type != PORT_UNKNOWN) {
2148 unsigned long flags;
2150 uart_report_port(drv, port);
2152 /* Power up port for set_mctrl() */
2153 uart_change_pm(state, UART_PM_STATE_ON);
2156 * Ensure that the modem control lines are de-activated.
2157 * keep the DTR setting that is set in uart_set_options()
2158 * We probably don't need a spinlock around this, but
2160 spin_lock_irqsave(&port->lock, flags);
2161 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2162 spin_unlock_irqrestore(&port->lock, flags);
2165 * If this driver supports console, and it hasn't been
2166 * successfully registered yet, try to re-register it.
2167 * It may be that the port was not available.
2169 if (port->cons && !(port->cons->flags & CON_ENABLED))
2170 register_console(port->cons);
2173 * Power down all ports by default, except the
2174 * console if we have one.
2176 if (!uart_console(port))
2177 uart_change_pm(state, UART_PM_STATE_OFF);
2181 #ifdef CONFIG_CONSOLE_POLL
2183 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2185 struct uart_driver *drv = driver->driver_state;
2186 struct uart_state *state = drv->state + line;
2187 struct uart_port *port;
2194 if (!state || !state->uart_port)
2197 port = state->uart_port;
2198 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2201 if (port->ops->poll_init) {
2202 struct tty_port *tport = &state->port;
2205 mutex_lock(&tport->mutex);
2207 * We don't set ASYNCB_INITIALIZED as we only initialized the
2208 * hw, e.g. state->xmit is still uninitialized.
2210 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2211 ret = port->ops->poll_init(port);
2212 mutex_unlock(&tport->mutex);
2218 uart_parse_options(options, &baud, &parity, &bits, &flow);
2219 return uart_set_options(port, NULL, baud, parity, bits, flow);
2225 static int uart_poll_get_char(struct tty_driver *driver, int line)
2227 struct uart_driver *drv = driver->driver_state;
2228 struct uart_state *state = drv->state + line;
2229 struct uart_port *port;
2231 if (!state || !state->uart_port)
2234 port = state->uart_port;
2235 return port->ops->poll_get_char(port);
2238 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2240 struct uart_driver *drv = driver->driver_state;
2241 struct uart_state *state = drv->state + line;
2242 struct uart_port *port;
2244 if (!state || !state->uart_port)
2247 port = state->uart_port;
2250 port->ops->poll_put_char(port, '\r');
2251 port->ops->poll_put_char(port, ch);
2255 static const struct tty_operations uart_ops = {
2257 .close = uart_close,
2258 .write = uart_write,
2259 .put_char = uart_put_char,
2260 .flush_chars = uart_flush_chars,
2261 .write_room = uart_write_room,
2262 .chars_in_buffer= uart_chars_in_buffer,
2263 .flush_buffer = uart_flush_buffer,
2264 .ioctl = uart_ioctl,
2265 .throttle = uart_throttle,
2266 .unthrottle = uart_unthrottle,
2267 .send_xchar = uart_send_xchar,
2268 .set_termios = uart_set_termios,
2269 .set_ldisc = uart_set_ldisc,
2271 .start = uart_start,
2272 .hangup = uart_hangup,
2273 .break_ctl = uart_break_ctl,
2274 .wait_until_sent= uart_wait_until_sent,
2275 #ifdef CONFIG_PROC_FS
2276 .proc_fops = &uart_proc_fops,
2278 .tiocmget = uart_tiocmget,
2279 .tiocmset = uart_tiocmset,
2280 .get_icount = uart_get_icount,
2281 #ifdef CONFIG_CONSOLE_POLL
2282 .poll_init = uart_poll_init,
2283 .poll_get_char = uart_poll_get_char,
2284 .poll_put_char = uart_poll_put_char,
2288 static const struct tty_port_operations uart_port_ops = {
2289 .activate = uart_port_activate,
2290 .shutdown = uart_port_shutdown,
2291 .carrier_raised = uart_carrier_raised,
2292 .dtr_rts = uart_dtr_rts,
2296 * uart_register_driver - register a driver with the uart core layer
2297 * @drv: low level driver structure
2299 * Register a uart driver with the core driver. We in turn register
2300 * with the tty layer, and initialise the core driver per-port state.
2302 * We have a proc file in /proc/tty/driver which is named after the
2305 * drv->port should be NULL, and the per-port structures should be
2306 * registered using uart_add_one_port after this call has succeeded.
2308 int uart_register_driver(struct uart_driver *drv)
2310 struct tty_driver *normal;
2316 * Maybe we should be using a slab cache for this, especially if
2317 * we have a large number of ports to handle.
2319 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2323 normal = alloc_tty_driver(drv->nr);
2327 drv->tty_driver = normal;
2329 normal->driver_name = drv->driver_name;
2330 normal->name = drv->dev_name;
2331 normal->major = drv->major;
2332 normal->minor_start = drv->minor;
2333 normal->type = TTY_DRIVER_TYPE_SERIAL;
2334 normal->subtype = SERIAL_TYPE_NORMAL;
2335 normal->init_termios = tty_std_termios;
2336 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2337 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2338 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2339 normal->driver_state = drv;
2340 tty_set_operations(normal, &uart_ops);
2343 * Initialise the UART state(s).
2345 for (i = 0; i < drv->nr; i++) {
2346 struct uart_state *state = drv->state + i;
2347 struct tty_port *port = &state->port;
2349 tty_port_init(port);
2350 port->ops = &uart_port_ops;
2351 port->close_delay = HZ / 2; /* .5 seconds */
2352 port->closing_wait = 30 * HZ;/* 30 seconds */
2355 retval = tty_register_driver(normal);
2359 for (i = 0; i < drv->nr; i++)
2360 tty_port_destroy(&drv->state[i].port);
2361 put_tty_driver(normal);
2369 * uart_unregister_driver - remove a driver from the uart core layer
2370 * @drv: low level driver structure
2372 * Remove all references to a driver from the core driver. The low
2373 * level driver must have removed all its ports via the
2374 * uart_remove_one_port() if it registered them with uart_add_one_port().
2375 * (ie, drv->port == NULL)
2377 void uart_unregister_driver(struct uart_driver *drv)
2379 struct tty_driver *p = drv->tty_driver;
2382 tty_unregister_driver(p);
2384 for (i = 0; i < drv->nr; i++)
2385 tty_port_destroy(&drv->state[i].port);
2388 drv->tty_driver = NULL;
2391 struct tty_driver *uart_console_device(struct console *co, int *index)
2393 struct uart_driver *p = co->data;
2395 return p->tty_driver;
2398 static ssize_t uart_get_attr_uartclk(struct device *dev,
2399 struct device_attribute *attr, char *buf)
2401 struct serial_struct tmp;
2402 struct tty_port *port = dev_get_drvdata(dev);
2404 uart_get_info(port, &tmp);
2405 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2408 static ssize_t uart_get_attr_type(struct device *dev,
2409 struct device_attribute *attr, char *buf)
2411 struct serial_struct tmp;
2412 struct tty_port *port = dev_get_drvdata(dev);
2414 uart_get_info(port, &tmp);
2415 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2417 static ssize_t uart_get_attr_line(struct device *dev,
2418 struct device_attribute *attr, char *buf)
2420 struct serial_struct tmp;
2421 struct tty_port *port = dev_get_drvdata(dev);
2423 uart_get_info(port, &tmp);
2424 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2427 static ssize_t uart_get_attr_port(struct device *dev,
2428 struct device_attribute *attr, char *buf)
2430 struct serial_struct tmp;
2431 struct tty_port *port = dev_get_drvdata(dev);
2432 unsigned long ioaddr;
2434 uart_get_info(port, &tmp);
2436 if (HIGH_BITS_OFFSET)
2437 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2438 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2441 static ssize_t uart_get_attr_irq(struct device *dev,
2442 struct device_attribute *attr, char *buf)
2444 struct serial_struct tmp;
2445 struct tty_port *port = dev_get_drvdata(dev);
2447 uart_get_info(port, &tmp);
2448 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2451 static ssize_t uart_get_attr_flags(struct device *dev,
2452 struct device_attribute *attr, char *buf)
2454 struct serial_struct tmp;
2455 struct tty_port *port = dev_get_drvdata(dev);
2457 uart_get_info(port, &tmp);
2458 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2461 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2462 struct device_attribute *attr, char *buf)
2464 struct serial_struct tmp;
2465 struct tty_port *port = dev_get_drvdata(dev);
2467 uart_get_info(port, &tmp);
2468 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2472 static ssize_t uart_get_attr_close_delay(struct device *dev,
2473 struct device_attribute *attr, char *buf)
2475 struct serial_struct tmp;
2476 struct tty_port *port = dev_get_drvdata(dev);
2478 uart_get_info(port, &tmp);
2479 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2483 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2484 struct device_attribute *attr, char *buf)
2486 struct serial_struct tmp;
2487 struct tty_port *port = dev_get_drvdata(dev);
2489 uart_get_info(port, &tmp);
2490 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2493 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2494 struct device_attribute *attr, char *buf)
2496 struct serial_struct tmp;
2497 struct tty_port *port = dev_get_drvdata(dev);
2499 uart_get_info(port, &tmp);
2500 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2503 static ssize_t uart_get_attr_io_type(struct device *dev,
2504 struct device_attribute *attr, char *buf)
2506 struct serial_struct tmp;
2507 struct tty_port *port = dev_get_drvdata(dev);
2509 uart_get_info(port, &tmp);
2510 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2513 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2514 struct device_attribute *attr, char *buf)
2516 struct serial_struct tmp;
2517 struct tty_port *port = dev_get_drvdata(dev);
2519 uart_get_info(port, &tmp);
2520 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2523 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2524 struct device_attribute *attr, char *buf)
2526 struct serial_struct tmp;
2527 struct tty_port *port = dev_get_drvdata(dev);
2529 uart_get_info(port, &tmp);
2530 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2533 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2534 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2535 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2536 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2537 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2538 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2539 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2540 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2541 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2542 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2543 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2544 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2545 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2547 static struct attribute *tty_dev_attrs[] = {
2548 &dev_attr_type.attr,
2549 &dev_attr_line.attr,
2550 &dev_attr_port.attr,
2552 &dev_attr_flags.attr,
2553 &dev_attr_xmit_fifo_size.attr,
2554 &dev_attr_uartclk.attr,
2555 &dev_attr_close_delay.attr,
2556 &dev_attr_closing_wait.attr,
2557 &dev_attr_custom_divisor.attr,
2558 &dev_attr_io_type.attr,
2559 &dev_attr_iomem_base.attr,
2560 &dev_attr_iomem_reg_shift.attr,
2564 static const struct attribute_group tty_dev_attr_group = {
2565 .attrs = tty_dev_attrs,
2569 * uart_add_one_port - attach a driver-defined port structure
2570 * @drv: pointer to the uart low level driver structure for this port
2571 * @uport: uart port structure to use for this port.
2573 * This allows the driver to register its own uart_port structure
2574 * with the core driver. The main purpose is to allow the low
2575 * level uart drivers to expand uart_port, rather than having yet
2576 * more levels of structures.
2578 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2580 struct uart_state *state;
2581 struct tty_port *port;
2583 struct device *tty_dev;
2586 BUG_ON(in_interrupt());
2588 if (uport->line >= drv->nr)
2591 state = drv->state + uport->line;
2592 port = &state->port;
2594 mutex_lock(&port_mutex);
2595 mutex_lock(&port->mutex);
2596 if (state->uart_port) {
2601 state->uart_port = uport;
2602 state->pm_state = UART_PM_STATE_UNDEFINED;
2604 uport->cons = drv->cons;
2605 uport->state = state;
2608 * If this port is a console, then the spinlock is already
2611 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2612 spin_lock_init(&uport->lock);
2613 lockdep_set_class(&uport->lock, &port_lock_key);
2615 if (uport->cons && uport->dev)
2616 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2618 uart_configure_port(drv, state, uport);
2621 if (uport->attr_group)
2624 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2626 if (!uport->tty_groups) {
2630 uport->tty_groups[0] = &tty_dev_attr_group;
2631 if (uport->attr_group)
2632 uport->tty_groups[1] = uport->attr_group;
2635 * Register the port whether it's detected or not. This allows
2636 * setserial to be used to alter this port's parameters.
2638 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2639 uport->line, uport->dev, port, uport->tty_groups);
2640 if (likely(!IS_ERR(tty_dev))) {
2641 device_set_wakeup_capable(tty_dev, 1);
2643 printk(KERN_ERR "Cannot register tty device on line %d\n",
2648 * Ensure UPF_DEAD is not set.
2650 uport->flags &= ~UPF_DEAD;
2653 mutex_unlock(&port->mutex);
2654 mutex_unlock(&port_mutex);
2660 * uart_remove_one_port - detach a driver defined port structure
2661 * @drv: pointer to the uart low level driver structure for this port
2662 * @uport: uart port structure for this port
2664 * This unhooks (and hangs up) the specified port structure from the
2665 * core driver. No further calls will be made to the low-level code
2668 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2670 struct uart_state *state = drv->state + uport->line;
2671 struct tty_port *port = &state->port;
2672 struct tty_struct *tty;
2675 BUG_ON(in_interrupt());
2677 if (state->uart_port != uport)
2678 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2679 state->uart_port, uport);
2681 mutex_lock(&port_mutex);
2684 * Mark the port "dead" - this prevents any opens from
2685 * succeeding while we shut down the port.
2687 mutex_lock(&port->mutex);
2688 if (!state->uart_port) {
2689 mutex_unlock(&port->mutex);
2693 uport->flags |= UPF_DEAD;
2694 mutex_unlock(&port->mutex);
2697 * Remove the devices from the tty layer
2699 tty_unregister_device(drv->tty_driver, uport->line);
2701 tty = tty_port_tty_get(port);
2703 tty_vhangup(port->tty);
2708 * If the port is used as a console, unregister it
2710 if (uart_console(uport))
2711 unregister_console(uport->cons);
2714 * Free the port IO and memory resources, if any.
2716 if (uport->type != PORT_UNKNOWN)
2717 uport->ops->release_port(uport);
2718 kfree(uport->tty_groups);
2721 * Indicate that there isn't a port here anymore.
2723 uport->type = PORT_UNKNOWN;
2725 state->uart_port = NULL;
2727 mutex_unlock(&port_mutex);
2733 * Are the two ports equivalent?
2735 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2737 if (port1->iotype != port2->iotype)
2740 switch (port1->iotype) {
2742 return (port1->iobase == port2->iobase);
2744 return (port1->iobase == port2->iobase) &&
2745 (port1->hub6 == port2->hub6);
2750 return (port1->mapbase == port2->mapbase);
2754 EXPORT_SYMBOL(uart_match_port);
2757 * uart_handle_dcd_change - handle a change of carrier detect state
2758 * @uport: uart_port structure for the open port
2759 * @status: new carrier detect status, nonzero if active
2761 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2763 struct tty_port *port = &uport->state->port;
2764 struct tty_struct *tty = port->tty;
2765 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2768 if (ld->ops->dcd_change)
2769 ld->ops->dcd_change(tty, status);
2770 tty_ldisc_deref(ld);
2773 uport->icount.dcd++;
2775 if (port->flags & ASYNC_CHECK_CD) {
2777 wake_up_interruptible(&port->open_wait);
2782 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2785 * uart_handle_cts_change - handle a change of clear-to-send state
2786 * @uport: uart_port structure for the open port
2787 * @status: new clear to send status, nonzero if active
2789 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2791 struct tty_port *port = &uport->state->port;
2792 struct tty_struct *tty = port->tty;
2794 uport->icount.cts++;
2796 /* skip below code if the hw flow control is supported */
2797 if (tty_port_cts_enabled(port) &&
2798 !(uport->flags & UPF_HARD_FLOW)) {
2799 if (tty->hw_stopped) {
2801 tty->hw_stopped = 0;
2802 uport->ops->start_tx(uport);
2803 uart_write_wakeup(uport);
2807 tty->hw_stopped = 1;
2808 uport->ops->stop_tx(uport);
2813 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2816 * uart_insert_char - push a char to the uart layer
2818 * User is responsible to call tty_flip_buffer_push when they are done with
2821 * @port: corresponding port
2822 * @status: state of the serial port RX buffer (LSR for 8250)
2823 * @overrun: mask of overrun bits in @status
2824 * @ch: character to push
2825 * @flag: flag for the character (see TTY_NORMAL and friends)
2827 void uart_insert_char(struct uart_port *port, unsigned int status,
2828 unsigned int overrun, unsigned int ch, unsigned int flag)
2830 struct tty_port *tport = &port->state->port;
2832 if ((status & port->ignore_status_mask & ~overrun) == 0)
2833 if (tty_insert_flip_char(tport, ch, flag) == 0)
2834 ++port->icount.buf_overrun;
2837 * Overrun is special. Since it's reported immediately,
2838 * it doesn't affect the current character.
2840 if (status & ~port->ignore_status_mask & overrun)
2841 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2842 ++port->icount.buf_overrun;
2844 EXPORT_SYMBOL_GPL(uart_insert_char);
2846 EXPORT_SYMBOL(uart_write_wakeup);
2847 EXPORT_SYMBOL(uart_register_driver);
2848 EXPORT_SYMBOL(uart_unregister_driver);
2849 EXPORT_SYMBOL(uart_suspend_port);
2850 EXPORT_SYMBOL(uart_resume_port);
2851 EXPORT_SYMBOL(uart_add_one_port);
2852 EXPORT_SYMBOL(uart_remove_one_port);
2854 MODULE_DESCRIPTION("Serial driver core");
2855 MODULE_LICENSE("GPL");