2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/proc_fs.h>
30 #include <linux/seq_file.h>
31 #include <linux/device.h>
32 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33 #include <linux/serial_core.h>
34 #include <linux/delay.h>
35 #include <linux/mutex.h>
38 #include <asm/uaccess.h>
41 * This is used to lock changes in serial line configuration.
43 static DEFINE_MUTEX(port_mutex);
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
49 static struct lock_class_key port_lock_key;
51 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
54 struct ktermios *old_termios);
55 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
56 static void uart_change_pm(struct uart_state *state,
57 enum uart_pm_state pm_state);
59 static void uart_port_shutdown(struct tty_port *port);
62 * This routine is used by the interrupt handler to schedule processing in
63 * the software interrupt portion of the driver.
65 void uart_write_wakeup(struct uart_port *port)
67 struct uart_state *state = port->state;
69 * This means you called this function _after_ the port was
70 * closed. No cookie for you.
73 tty_wakeup(state->port.tty);
76 static void uart_stop(struct tty_struct *tty)
78 struct uart_state *state = tty->driver_data;
79 struct uart_port *port = state->uart_port;
82 spin_lock_irqsave(&port->lock, flags);
83 port->ops->stop_tx(port);
84 spin_unlock_irqrestore(&port->lock, flags);
87 static void __uart_start(struct tty_struct *tty)
89 struct uart_state *state = tty->driver_data;
90 struct uart_port *port = state->uart_port;
92 if (!tty->stopped && !tty->hw_stopped)
93 port->ops->start_tx(port);
96 static void uart_start(struct tty_struct *tty)
98 struct uart_state *state = tty->driver_data;
99 struct uart_port *port = state->uart_port;
102 spin_lock_irqsave(&port->lock, flags);
104 spin_unlock_irqrestore(&port->lock, flags);
108 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
113 spin_lock_irqsave(&port->lock, flags);
115 port->mctrl = (old & ~clear) | set;
116 if (old != port->mctrl)
117 port->ops->set_mctrl(port, port->mctrl);
118 spin_unlock_irqrestore(&port->lock, flags);
121 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
122 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
125 * Startup the port. This will be called once per open. All calls
126 * will be serialised by the per-port mutex.
128 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
131 struct uart_port *uport = state->uart_port;
132 struct tty_port *port = &state->port;
136 if (uport->type == PORT_UNKNOWN)
140 * Make sure the device is in D0 state.
142 uart_change_pm(state, UART_PM_STATE_ON);
145 * Initialise and allocate the transmit and temporary
148 if (!state->xmit.buf) {
149 /* This is protected by the per port mutex */
150 page = get_zeroed_page(GFP_KERNEL);
154 state->xmit.buf = (unsigned char *) page;
155 uart_circ_clear(&state->xmit);
158 retval = uport->ops->startup(uport);
160 if (uart_console(uport) && uport->cons->cflag) {
161 tty->termios.c_cflag = uport->cons->cflag;
162 uport->cons->cflag = 0;
165 * Initialise the hardware port settings.
167 uart_change_speed(tty, state, NULL);
171 * Setup the RTS and DTR signals once the
172 * port is open and ready to respond.
174 if (tty->termios.c_cflag & CBAUD)
175 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
178 if (tty_port_cts_enabled(port)) {
179 spin_lock_irq(&uport->lock);
180 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
182 spin_unlock_irq(&uport->lock);
187 * This is to allow setserial on this port. People may want to set
188 * port/irq/type and then reconfigure the port properly if it failed
191 if (retval && capable(CAP_SYS_ADMIN))
197 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
200 struct tty_port *port = &state->port;
203 if (port->flags & ASYNC_INITIALIZED)
207 * Set the TTY IO error marker - we will only clear this
208 * once we have successfully opened the port.
210 set_bit(TTY_IO_ERROR, &tty->flags);
212 retval = uart_port_startup(tty, state, init_hw);
214 set_bit(ASYNCB_INITIALIZED, &port->flags);
215 clear_bit(TTY_IO_ERROR, &tty->flags);
216 } else if (retval > 0)
223 * This routine will shutdown a serial port; interrupts are disabled, and
224 * DTR is dropped if the hangup on close termio flag is on. Calls to
225 * uart_shutdown are serialised by the per-port semaphore.
227 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
229 struct uart_port *uport = state->uart_port;
230 struct tty_port *port = &state->port;
233 * Set the TTY IO error marker
236 set_bit(TTY_IO_ERROR, &tty->flags);
238 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
240 * Turn off DTR and RTS early.
242 if (!tty || (tty->termios.c_cflag & HUPCL))
243 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
245 uart_port_shutdown(port);
249 * It's possible for shutdown to be called after suspend if we get
250 * a DCD drop (hangup) at just the right time. Clear suspended bit so
251 * we don't try to resume a port that has been shutdown.
253 clear_bit(ASYNCB_SUSPENDED, &port->flags);
256 * Free the transmit buffer page.
258 if (state->xmit.buf) {
259 free_page((unsigned long)state->xmit.buf);
260 state->xmit.buf = NULL;
265 * uart_update_timeout - update per-port FIFO timeout.
266 * @port: uart_port structure describing the port
267 * @cflag: termios cflag value
268 * @baud: speed of the port
270 * Set the port FIFO timeout value. The @cflag value should
271 * reflect the actual hardware settings.
274 uart_update_timeout(struct uart_port *port, unsigned int cflag,
279 /* byte size and parity */
280 switch (cflag & CSIZE) {
301 * The total number of bits to be transmitted in the fifo.
303 bits = bits * port->fifosize;
306 * Figure the timeout to send the above number of bits.
307 * Add .02 seconds of slop
309 port->timeout = (HZ * bits) / baud + HZ/50;
312 EXPORT_SYMBOL(uart_update_timeout);
315 * uart_get_baud_rate - return baud rate for a particular port
316 * @port: uart_port structure describing the port in question.
317 * @termios: desired termios settings.
318 * @old: old termios (or NULL)
319 * @min: minimum acceptable baud rate
320 * @max: maximum acceptable baud rate
322 * Decode the termios structure into a numeric baud rate,
323 * taking account of the magic 38400 baud rate (with spd_*
324 * flags), and mapping the %B0 rate to 9600 baud.
326 * If the new baud rate is invalid, try the old termios setting.
327 * If it's still invalid, we try 9600 baud.
329 * Update the @termios structure to reflect the baud rate
330 * we're actually going to be using. Don't do this for the case
331 * where B0 is requested ("hang up").
334 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
335 struct ktermios *old, unsigned int min, unsigned int max)
337 unsigned int try, baud, altbaud = 38400;
339 upf_t flags = port->flags & UPF_SPD_MASK;
341 if (flags == UPF_SPD_HI)
343 else if (flags == UPF_SPD_VHI)
345 else if (flags == UPF_SPD_SHI)
347 else if (flags == UPF_SPD_WARP)
350 for (try = 0; try < 2; try++) {
351 baud = tty_termios_baud_rate(termios);
354 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
361 * Special case: B0 rate.
368 if (baud >= min && baud <= max)
372 * Oops, the quotient was zero. Try again with
373 * the old baud rate if possible.
375 termios->c_cflag &= ~CBAUD;
377 baud = tty_termios_baud_rate(old);
379 tty_termios_encode_baud_rate(termios,
386 * As a last resort, if the range cannot be met then clip to
387 * the nearest chip supported rate.
391 tty_termios_encode_baud_rate(termios,
394 tty_termios_encode_baud_rate(termios,
398 /* Should never happen */
403 EXPORT_SYMBOL(uart_get_baud_rate);
406 * uart_get_divisor - return uart clock divisor
407 * @port: uart_port structure describing the port.
408 * @baud: desired baud rate
410 * Calculate the uart clock divisor for the port.
413 uart_get_divisor(struct uart_port *port, unsigned int baud)
418 * Old custom speed handling.
420 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
421 quot = port->custom_divisor;
423 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
428 EXPORT_SYMBOL(uart_get_divisor);
430 /* FIXME: Consistent locking policy */
431 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
432 struct ktermios *old_termios)
434 struct tty_port *port = &state->port;
435 struct uart_port *uport = state->uart_port;
436 struct ktermios *termios;
439 * If we have no tty, termios, or the port does not exist,
440 * then we can't set the parameters for this port.
442 if (!tty || uport->type == PORT_UNKNOWN)
445 termios = &tty->termios;
448 * Set flags based on termios cflag
450 if (termios->c_cflag & CRTSCTS)
451 set_bit(ASYNCB_CTS_FLOW, &port->flags);
453 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
455 if (termios->c_cflag & CLOCAL)
456 clear_bit(ASYNCB_CHECK_CD, &port->flags);
458 set_bit(ASYNCB_CHECK_CD, &port->flags);
460 uport->ops->set_termios(uport, termios, old_termios);
463 static inline int __uart_put_char(struct uart_port *port,
464 struct circ_buf *circ, unsigned char c)
472 spin_lock_irqsave(&port->lock, flags);
473 if (uart_circ_chars_free(circ) != 0) {
474 circ->buf[circ->head] = c;
475 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
478 spin_unlock_irqrestore(&port->lock, flags);
482 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
484 struct uart_state *state = tty->driver_data;
486 return __uart_put_char(state->uart_port, &state->xmit, ch);
489 static void uart_flush_chars(struct tty_struct *tty)
494 static int uart_write(struct tty_struct *tty,
495 const unsigned char *buf, int count)
497 struct uart_state *state = tty->driver_data;
498 struct uart_port *port;
499 struct circ_buf *circ;
504 * This means you called this function _after_ the port was
505 * closed. No cookie for you.
512 port = state->uart_port;
518 spin_lock_irqsave(&port->lock, flags);
520 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
525 memcpy(circ->buf + circ->head, buf, c);
526 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
531 spin_unlock_irqrestore(&port->lock, flags);
537 static int uart_write_room(struct tty_struct *tty)
539 struct uart_state *state = tty->driver_data;
543 spin_lock_irqsave(&state->uart_port->lock, flags);
544 ret = uart_circ_chars_free(&state->xmit);
545 spin_unlock_irqrestore(&state->uart_port->lock, flags);
549 static int uart_chars_in_buffer(struct tty_struct *tty)
551 struct uart_state *state = tty->driver_data;
555 spin_lock_irqsave(&state->uart_port->lock, flags);
556 ret = uart_circ_chars_pending(&state->xmit);
557 spin_unlock_irqrestore(&state->uart_port->lock, flags);
561 static void uart_flush_buffer(struct tty_struct *tty)
563 struct uart_state *state = tty->driver_data;
564 struct uart_port *port;
568 * This means you called this function _after_ the port was
569 * closed. No cookie for you.
576 port = state->uart_port;
577 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
579 spin_lock_irqsave(&port->lock, flags);
580 uart_circ_clear(&state->xmit);
581 if (port->ops->flush_buffer)
582 port->ops->flush_buffer(port);
583 spin_unlock_irqrestore(&port->lock, flags);
588 * This function is used to send a high-priority XON/XOFF character to
591 static void uart_send_xchar(struct tty_struct *tty, char ch)
593 struct uart_state *state = tty->driver_data;
594 struct uart_port *port = state->uart_port;
597 if (port->ops->send_xchar)
598 port->ops->send_xchar(port, ch);
602 spin_lock_irqsave(&port->lock, flags);
603 port->ops->start_tx(port);
604 spin_unlock_irqrestore(&port->lock, flags);
609 static void uart_throttle(struct tty_struct *tty)
611 struct uart_state *state = tty->driver_data;
612 struct uart_port *port = state->uart_port;
616 mask |= UPF_SOFT_FLOW;
617 if (tty->termios.c_cflag & CRTSCTS)
618 mask |= UPF_HARD_FLOW;
620 if (port->flags & mask) {
621 port->ops->throttle(port);
622 mask &= ~port->flags;
625 if (mask & UPF_SOFT_FLOW)
626 uart_send_xchar(tty, STOP_CHAR(tty));
628 if (mask & UPF_HARD_FLOW)
629 uart_clear_mctrl(port, TIOCM_RTS);
632 static void uart_unthrottle(struct tty_struct *tty)
634 struct uart_state *state = tty->driver_data;
635 struct uart_port *port = state->uart_port;
639 mask |= UPF_SOFT_FLOW;
640 if (tty->termios.c_cflag & CRTSCTS)
641 mask |= UPF_HARD_FLOW;
643 if (port->flags & mask) {
644 port->ops->unthrottle(port);
645 mask &= ~port->flags;
648 if (mask & UPF_SOFT_FLOW) {
652 uart_send_xchar(tty, START_CHAR(tty));
655 if (mask & UPF_HARD_FLOW)
656 uart_set_mctrl(port, TIOCM_RTS);
659 static void do_uart_get_info(struct tty_port *port,
660 struct serial_struct *retinfo)
662 struct uart_state *state = container_of(port, struct uart_state, port);
663 struct uart_port *uport = state->uart_port;
665 memset(retinfo, 0, sizeof(*retinfo));
667 retinfo->type = uport->type;
668 retinfo->line = uport->line;
669 retinfo->port = uport->iobase;
670 if (HIGH_BITS_OFFSET)
671 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
672 retinfo->irq = uport->irq;
673 retinfo->flags = uport->flags;
674 retinfo->xmit_fifo_size = uport->fifosize;
675 retinfo->baud_base = uport->uartclk / 16;
676 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
677 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
678 ASYNC_CLOSING_WAIT_NONE :
679 jiffies_to_msecs(port->closing_wait) / 10;
680 retinfo->custom_divisor = uport->custom_divisor;
681 retinfo->hub6 = uport->hub6;
682 retinfo->io_type = uport->iotype;
683 retinfo->iomem_reg_shift = uport->regshift;
684 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
687 static void uart_get_info(struct tty_port *port,
688 struct serial_struct *retinfo)
690 /* Ensure the state we copy is consistent and no hardware changes
692 mutex_lock(&port->mutex);
693 do_uart_get_info(port, retinfo);
694 mutex_unlock(&port->mutex);
697 static int uart_get_info_user(struct tty_port *port,
698 struct serial_struct __user *retinfo)
700 struct serial_struct tmp;
701 uart_get_info(port, &tmp);
703 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
708 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
709 struct uart_state *state,
710 struct serial_struct *new_info)
712 struct uart_port *uport = state->uart_port;
713 unsigned long new_port;
714 unsigned int change_irq, change_port, closing_wait;
715 unsigned int old_custom_divisor, close_delay;
716 upf_t old_flags, new_flags;
719 new_port = new_info->port;
720 if (HIGH_BITS_OFFSET)
721 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
723 new_info->irq = irq_canonicalize(new_info->irq);
724 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
725 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
726 ASYNC_CLOSING_WAIT_NONE :
727 msecs_to_jiffies(new_info->closing_wait * 10);
730 change_irq = !(uport->flags & UPF_FIXED_PORT)
731 && new_info->irq != uport->irq;
734 * Since changing the 'type' of the port changes its resource
735 * allocations, we should treat type changes the same as
738 change_port = !(uport->flags & UPF_FIXED_PORT)
739 && (new_port != uport->iobase ||
740 (unsigned long)new_info->iomem_base != uport->mapbase ||
741 new_info->hub6 != uport->hub6 ||
742 new_info->io_type != uport->iotype ||
743 new_info->iomem_reg_shift != uport->regshift ||
744 new_info->type != uport->type);
746 old_flags = uport->flags;
747 new_flags = new_info->flags;
748 old_custom_divisor = uport->custom_divisor;
750 if (!capable(CAP_SYS_ADMIN)) {
752 if (change_irq || change_port ||
753 (new_info->baud_base != uport->uartclk / 16) ||
754 (close_delay != port->close_delay) ||
755 (closing_wait != port->closing_wait) ||
756 (new_info->xmit_fifo_size &&
757 new_info->xmit_fifo_size != uport->fifosize) ||
758 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
760 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
761 (new_flags & UPF_USR_MASK));
762 uport->custom_divisor = new_info->custom_divisor;
767 * Ask the low level driver to verify the settings.
769 if (uport->ops->verify_port)
770 retval = uport->ops->verify_port(uport, new_info);
772 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
773 (new_info->baud_base < 9600))
779 if (change_port || change_irq) {
783 * Make sure that we are the sole user of this port.
785 if (tty_port_users(port) > 1)
789 * We need to shutdown the serial port at the old
790 * port/type/irq combination.
792 uart_shutdown(tty, state);
796 unsigned long old_iobase, old_mapbase;
797 unsigned int old_type, old_iotype, old_hub6, old_shift;
799 old_iobase = uport->iobase;
800 old_mapbase = uport->mapbase;
801 old_type = uport->type;
802 old_hub6 = uport->hub6;
803 old_iotype = uport->iotype;
804 old_shift = uport->regshift;
807 * Free and release old regions
809 if (old_type != PORT_UNKNOWN)
810 uport->ops->release_port(uport);
812 uport->iobase = new_port;
813 uport->type = new_info->type;
814 uport->hub6 = new_info->hub6;
815 uport->iotype = new_info->io_type;
816 uport->regshift = new_info->iomem_reg_shift;
817 uport->mapbase = (unsigned long)new_info->iomem_base;
820 * Claim and map the new regions
822 if (uport->type != PORT_UNKNOWN) {
823 retval = uport->ops->request_port(uport);
825 /* Always success - Jean II */
830 * If we fail to request resources for the
831 * new port, try to restore the old settings.
834 uport->iobase = old_iobase;
835 uport->type = old_type;
836 uport->hub6 = old_hub6;
837 uport->iotype = old_iotype;
838 uport->regshift = old_shift;
839 uport->mapbase = old_mapbase;
841 if (old_type != PORT_UNKNOWN) {
842 retval = uport->ops->request_port(uport);
844 * If we failed to restore the old settings,
848 uport->type = PORT_UNKNOWN;
856 /* Added to return the correct error -Ram Gupta */
862 uport->irq = new_info->irq;
863 if (!(uport->flags & UPF_FIXED_PORT))
864 uport->uartclk = new_info->baud_base * 16;
865 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
866 (new_flags & UPF_CHANGE_MASK);
867 uport->custom_divisor = new_info->custom_divisor;
868 port->close_delay = close_delay;
869 port->closing_wait = closing_wait;
870 if (new_info->xmit_fifo_size)
871 uport->fifosize = new_info->xmit_fifo_size;
872 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
876 if (uport->type == PORT_UNKNOWN)
878 if (port->flags & ASYNC_INITIALIZED) {
879 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
880 old_custom_divisor != uport->custom_divisor) {
882 * If they're setting up a custom divisor or speed,
883 * instead of clearing it, then bitch about it. No
884 * need to rate-limit; it's CAP_SYS_ADMIN only.
886 if (uport->flags & UPF_SPD_MASK) {
889 "%s sets custom speed on %s. This "
890 "is deprecated.\n", current->comm,
891 tty_name(port->tty, buf));
893 uart_change_speed(tty, state, NULL);
896 retval = uart_startup(tty, state, 1);
901 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
902 struct serial_struct __user *newinfo)
904 struct serial_struct new_serial;
905 struct tty_port *port = &state->port;
908 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
912 * This semaphore protects port->count. It is also
913 * very useful to prevent opens. Also, take the
914 * port configuration semaphore to make sure that a
915 * module insertion/removal doesn't change anything
918 mutex_lock(&port->mutex);
919 retval = uart_set_info(tty, port, state, &new_serial);
920 mutex_unlock(&port->mutex);
925 * uart_get_lsr_info - get line status register info
926 * @tty: tty associated with the UART
927 * @state: UART being queried
928 * @value: returned modem value
930 * Note: uart_ioctl protects us against hangups.
932 static int uart_get_lsr_info(struct tty_struct *tty,
933 struct uart_state *state, unsigned int __user *value)
935 struct uart_port *uport = state->uart_port;
938 result = uport->ops->tx_empty(uport);
941 * If we're about to load something into the transmit
942 * register, we'll pretend the transmitter isn't empty to
943 * avoid a race condition (depending on when the transmit
944 * interrupt happens).
947 ((uart_circ_chars_pending(&state->xmit) > 0) &&
948 !tty->stopped && !tty->hw_stopped))
949 result &= ~TIOCSER_TEMT;
951 return put_user(result, value);
954 static int uart_tiocmget(struct tty_struct *tty)
956 struct uart_state *state = tty->driver_data;
957 struct tty_port *port = &state->port;
958 struct uart_port *uport = state->uart_port;
961 mutex_lock(&port->mutex);
962 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
963 result = uport->mctrl;
964 spin_lock_irq(&uport->lock);
965 result |= uport->ops->get_mctrl(uport);
966 spin_unlock_irq(&uport->lock);
968 mutex_unlock(&port->mutex);
974 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
976 struct uart_state *state = tty->driver_data;
977 struct uart_port *uport = state->uart_port;
978 struct tty_port *port = &state->port;
981 mutex_lock(&port->mutex);
982 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
983 uart_update_mctrl(uport, set, clear);
986 mutex_unlock(&port->mutex);
990 static int uart_break_ctl(struct tty_struct *tty, int break_state)
992 struct uart_state *state = tty->driver_data;
993 struct tty_port *port = &state->port;
994 struct uart_port *uport = state->uart_port;
996 mutex_lock(&port->mutex);
998 if (uport->type != PORT_UNKNOWN)
999 uport->ops->break_ctl(uport, break_state);
1001 mutex_unlock(&port->mutex);
1005 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1007 struct uart_port *uport = state->uart_port;
1008 struct tty_port *port = &state->port;
1011 if (!capable(CAP_SYS_ADMIN))
1015 * Take the per-port semaphore. This prevents count from
1016 * changing, and hence any extra opens of the port while
1017 * we're auto-configuring.
1019 if (mutex_lock_interruptible(&port->mutex))
1020 return -ERESTARTSYS;
1023 if (tty_port_users(port) == 1) {
1024 uart_shutdown(tty, state);
1027 * If we already have a port type configured,
1028 * we must release its resources.
1030 if (uport->type != PORT_UNKNOWN)
1031 uport->ops->release_port(uport);
1033 flags = UART_CONFIG_TYPE;
1034 if (uport->flags & UPF_AUTO_IRQ)
1035 flags |= UART_CONFIG_IRQ;
1038 * This will claim the ports resources if
1041 uport->ops->config_port(uport, flags);
1043 ret = uart_startup(tty, state, 1);
1045 mutex_unlock(&port->mutex);
1050 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1051 * - mask passed in arg for lines of interest
1052 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1053 * Caller should use TIOCGICOUNT to see which one it was
1055 * FIXME: This wants extracting into a common all driver implementation
1056 * of TIOCMWAIT using tty_port.
1059 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1061 struct uart_port *uport = state->uart_port;
1062 struct tty_port *port = &state->port;
1063 DECLARE_WAITQUEUE(wait, current);
1064 struct uart_icount cprev, cnow;
1068 * note the counters on entry
1070 spin_lock_irq(&uport->lock);
1071 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1074 * Force modem status interrupts on
1076 uport->ops->enable_ms(uport);
1077 spin_unlock_irq(&uport->lock);
1079 add_wait_queue(&port->delta_msr_wait, &wait);
1081 spin_lock_irq(&uport->lock);
1082 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1083 spin_unlock_irq(&uport->lock);
1085 set_current_state(TASK_INTERRUPTIBLE);
1087 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1088 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1089 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1090 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1097 /* see if a signal did it */
1098 if (signal_pending(current)) {
1106 current->state = TASK_RUNNING;
1107 remove_wait_queue(&port->delta_msr_wait, &wait);
1113 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1114 * Return: write counters to the user passed counter struct
1115 * NB: both 1->0 and 0->1 transitions are counted except for
1116 * RI where only 0->1 is counted.
1118 static int uart_get_icount(struct tty_struct *tty,
1119 struct serial_icounter_struct *icount)
1121 struct uart_state *state = tty->driver_data;
1122 struct uart_icount cnow;
1123 struct uart_port *uport = state->uart_port;
1125 spin_lock_irq(&uport->lock);
1126 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1127 spin_unlock_irq(&uport->lock);
1129 icount->cts = cnow.cts;
1130 icount->dsr = cnow.dsr;
1131 icount->rng = cnow.rng;
1132 icount->dcd = cnow.dcd;
1133 icount->rx = cnow.rx;
1134 icount->tx = cnow.tx;
1135 icount->frame = cnow.frame;
1136 icount->overrun = cnow.overrun;
1137 icount->parity = cnow.parity;
1138 icount->brk = cnow.brk;
1139 icount->buf_overrun = cnow.buf_overrun;
1145 * Called via sys_ioctl. We can use spin_lock_irq() here.
1148 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1151 struct uart_state *state = tty->driver_data;
1152 struct tty_port *port = &state->port;
1153 void __user *uarg = (void __user *)arg;
1154 int ret = -ENOIOCTLCMD;
1158 * These ioctls don't rely on the hardware to be present.
1162 ret = uart_get_info_user(port, uarg);
1166 ret = uart_set_info_user(tty, state, uarg);
1170 ret = uart_do_autoconfig(tty, state);
1173 case TIOCSERGWILD: /* obsolete */
1174 case TIOCSERSWILD: /* obsolete */
1179 if (ret != -ENOIOCTLCMD)
1182 if (tty->flags & (1 << TTY_IO_ERROR)) {
1188 * The following should only be used when hardware is present.
1192 ret = uart_wait_modem_status(state, arg);
1196 if (ret != -ENOIOCTLCMD)
1199 mutex_lock(&port->mutex);
1201 if (tty->flags & (1 << TTY_IO_ERROR)) {
1207 * All these rely on hardware being present and need to be
1208 * protected against the tty being hung up.
1211 case TIOCSERGETLSR: /* Get line status register */
1212 ret = uart_get_lsr_info(tty, state, uarg);
1216 struct uart_port *uport = state->uart_port;
1217 if (uport->ops->ioctl)
1218 ret = uport->ops->ioctl(uport, cmd, arg);
1223 mutex_unlock(&port->mutex);
1228 static void uart_set_ldisc(struct tty_struct *tty)
1230 struct uart_state *state = tty->driver_data;
1231 struct uart_port *uport = state->uart_port;
1233 if (uport->ops->set_ldisc)
1234 uport->ops->set_ldisc(uport, tty->termios.c_line);
1237 static void uart_set_termios(struct tty_struct *tty,
1238 struct ktermios *old_termios)
1240 struct uart_state *state = tty->driver_data;
1241 struct uart_port *uport = state->uart_port;
1242 unsigned long flags;
1243 unsigned int cflag = tty->termios.c_cflag;
1244 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1245 bool sw_changed = false;
1248 * Drivers doing software flow control also need to know
1249 * about changes to these input settings.
1251 if (uport->flags & UPF_SOFT_FLOW) {
1252 iflag_mask |= IXANY|IXON|IXOFF;
1254 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1255 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1259 * These are the bits that are used to setup various
1260 * flags in the low level driver. We can ignore the Bfoo
1261 * bits in c_cflag; c_[io]speed will always be set
1262 * appropriately by set_termios() in tty_ioctl.c
1264 if ((cflag ^ old_termios->c_cflag) == 0 &&
1265 tty->termios.c_ospeed == old_termios->c_ospeed &&
1266 tty->termios.c_ispeed == old_termios->c_ispeed &&
1267 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1272 uart_change_speed(tty, state, old_termios);
1274 /* Handle transition to B0 status */
1275 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1276 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1277 /* Handle transition away from B0 status */
1278 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1279 unsigned int mask = TIOCM_DTR;
1280 if (!(cflag & CRTSCTS) ||
1281 !test_bit(TTY_THROTTLED, &tty->flags))
1283 uart_set_mctrl(uport, mask);
1287 * If the port is doing h/w assisted flow control, do nothing.
1288 * We assume that tty->hw_stopped has never been set.
1290 if (uport->flags & UPF_HARD_FLOW)
1293 /* Handle turning off CRTSCTS */
1294 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1295 spin_lock_irqsave(&uport->lock, flags);
1296 tty->hw_stopped = 0;
1298 spin_unlock_irqrestore(&uport->lock, flags);
1300 /* Handle turning on CRTSCTS */
1301 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1302 spin_lock_irqsave(&uport->lock, flags);
1303 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1304 tty->hw_stopped = 1;
1305 uport->ops->stop_tx(uport);
1307 spin_unlock_irqrestore(&uport->lock, flags);
1312 * Calls to uart_close() are serialised via the tty_lock in
1313 * drivers/tty/tty_io.c:tty_release()
1314 * drivers/tty/tty_io.c:do_tty_hangup()
1315 * This runs from a workqueue and can sleep for a _short_ time only.
1317 static void uart_close(struct tty_struct *tty, struct file *filp)
1319 struct uart_state *state = tty->driver_data;
1320 struct tty_port *port;
1321 struct uart_port *uport;
1322 unsigned long flags;
1327 uport = state->uart_port;
1328 port = &state->port;
1330 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1332 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1336 * At this point, we stop accepting input. To do this, we
1337 * disable the receive line status interrupts.
1339 if (port->flags & ASYNC_INITIALIZED) {
1340 unsigned long flags;
1341 spin_lock_irqsave(&uport->lock, flags);
1342 uport->ops->stop_rx(uport);
1343 spin_unlock_irqrestore(&uport->lock, flags);
1345 * Before we drop DTR, make sure the UART transmitter
1346 * has completely drained; this is especially
1347 * important if there is a transmit FIFO!
1349 uart_wait_until_sent(tty, uport->timeout);
1352 mutex_lock(&port->mutex);
1353 uart_shutdown(tty, state);
1354 uart_flush_buffer(tty);
1356 tty_ldisc_flush(tty);
1358 tty_port_tty_set(port, NULL);
1359 spin_lock_irqsave(&port->lock, flags);
1362 if (port->blocked_open) {
1363 spin_unlock_irqrestore(&port->lock, flags);
1364 if (port->close_delay)
1365 msleep_interruptible(
1366 jiffies_to_msecs(port->close_delay));
1367 spin_lock_irqsave(&port->lock, flags);
1368 } else if (!uart_console(uport)) {
1369 spin_unlock_irqrestore(&port->lock, flags);
1370 uart_change_pm(state, UART_PM_STATE_OFF);
1371 spin_lock_irqsave(&port->lock, flags);
1375 * Wake up anyone trying to open this port.
1377 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1378 clear_bit(ASYNCB_CLOSING, &port->flags);
1379 spin_unlock_irqrestore(&port->lock, flags);
1380 wake_up_interruptible(&port->open_wait);
1381 wake_up_interruptible(&port->close_wait);
1383 mutex_unlock(&port->mutex);
1386 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1388 struct uart_state *state = tty->driver_data;
1389 struct uart_port *port = state->uart_port;
1390 unsigned long char_time, expire;
1392 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1396 * Set the check interval to be 1/5 of the estimated time to
1397 * send a single character, and make it at least 1. The check
1398 * interval should also be less than the timeout.
1400 * Note: we have to use pretty tight timings here to satisfy
1403 char_time = (port->timeout - HZ/50) / port->fifosize;
1404 char_time = char_time / 5;
1407 if (timeout && timeout < char_time)
1408 char_time = timeout;
1411 * If the transmitter hasn't cleared in twice the approximate
1412 * amount of time to send the entire FIFO, it probably won't
1413 * ever clear. This assumes the UART isn't doing flow
1414 * control, which is currently the case. Hence, if it ever
1415 * takes longer than port->timeout, this is probably due to a
1416 * UART bug of some kind. So, we clamp the timeout parameter at
1419 if (timeout == 0 || timeout > 2 * port->timeout)
1420 timeout = 2 * port->timeout;
1422 expire = jiffies + timeout;
1424 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1425 port->line, jiffies, expire);
1428 * Check whether the transmitter is empty every 'char_time'.
1429 * 'timeout' / 'expire' give us the maximum amount of time
1432 while (!port->ops->tx_empty(port)) {
1433 msleep_interruptible(jiffies_to_msecs(char_time));
1434 if (signal_pending(current))
1436 if (time_after(jiffies, expire))
1442 * Calls to uart_hangup() are serialised by the tty_lock in
1443 * drivers/tty/tty_io.c:do_tty_hangup()
1444 * This runs from a workqueue and can sleep for a _short_ time only.
1446 static void uart_hangup(struct tty_struct *tty)
1448 struct uart_state *state = tty->driver_data;
1449 struct tty_port *port = &state->port;
1450 unsigned long flags;
1452 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1454 mutex_lock(&port->mutex);
1455 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1456 uart_flush_buffer(tty);
1457 uart_shutdown(tty, state);
1458 spin_lock_irqsave(&port->lock, flags);
1460 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1461 spin_unlock_irqrestore(&port->lock, flags);
1462 tty_port_tty_set(port, NULL);
1463 if (!uart_console(state->uart_port))
1464 uart_change_pm(state, UART_PM_STATE_OFF);
1465 wake_up_interruptible(&port->open_wait);
1466 wake_up_interruptible(&port->delta_msr_wait);
1468 mutex_unlock(&port->mutex);
1471 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1476 static void uart_port_shutdown(struct tty_port *port)
1478 struct uart_state *state = container_of(port, struct uart_state, port);
1479 struct uart_port *uport = state->uart_port;
1482 * clear delta_msr_wait queue to avoid mem leaks: we may free
1483 * the irq here so the queue might never be woken up. Note
1484 * that we won't end up waiting on delta_msr_wait again since
1485 * any outstanding file descriptors should be pointing at
1486 * hung_up_tty_fops now.
1488 wake_up_interruptible(&port->delta_msr_wait);
1491 * Free the IRQ and disable the port.
1493 uport->ops->shutdown(uport);
1496 * Ensure that the IRQ handler isn't running on another CPU.
1498 synchronize_irq(uport->irq);
1501 static int uart_carrier_raised(struct tty_port *port)
1503 struct uart_state *state = container_of(port, struct uart_state, port);
1504 struct uart_port *uport = state->uart_port;
1506 spin_lock_irq(&uport->lock);
1507 uport->ops->enable_ms(uport);
1508 mctrl = uport->ops->get_mctrl(uport);
1509 spin_unlock_irq(&uport->lock);
1510 if (mctrl & TIOCM_CAR)
1515 static void uart_dtr_rts(struct tty_port *port, int onoff)
1517 struct uart_state *state = container_of(port, struct uart_state, port);
1518 struct uart_port *uport = state->uart_port;
1521 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1523 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1527 * Calls to uart_open are serialised by the tty_lock in
1528 * drivers/tty/tty_io.c:tty_open()
1529 * Note that if this fails, then uart_close() _will_ be called.
1531 * In time, we want to scrap the "opening nonpresent ports"
1532 * behaviour and implement an alternative way for setserial
1533 * to set base addresses/ports/types. This will allow us to
1534 * get rid of a certain amount of extra tests.
1536 static int uart_open(struct tty_struct *tty, struct file *filp)
1538 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1539 int retval, line = tty->index;
1540 struct uart_state *state = drv->state + line;
1541 struct tty_port *port = &state->port;
1543 pr_debug("uart_open(%d) called\n", line);
1546 * We take the semaphore here to guarantee that we won't be re-entered
1547 * while allocating the state structure, or while we request any IRQs
1548 * that the driver may need. This also has the nice side-effect that
1549 * it delays the action of uart_hangup, so we can guarantee that
1550 * state->port.tty will always contain something reasonable.
1552 if (mutex_lock_interruptible(&port->mutex)) {
1553 retval = -ERESTARTSYS;
1558 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1564 * Once we set tty->driver_data here, we are guaranteed that
1565 * uart_close() will decrement the driver module use count.
1566 * Any failures from here onwards should not touch the count.
1568 tty->driver_data = state;
1569 state->uart_port->state = state;
1570 state->port.low_latency =
1571 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1572 tty_port_tty_set(port, tty);
1575 * If the port is in the middle of closing, bail out now.
1577 if (tty_hung_up_p(filp)) {
1583 * Start up the serial port.
1585 retval = uart_startup(tty, state, 0);
1588 * If we succeeded, wait until the port is ready.
1590 mutex_unlock(&port->mutex);
1592 retval = tty_port_block_til_ready(port, tty, filp);
1598 mutex_unlock(&port->mutex);
1602 static const char *uart_type(struct uart_port *port)
1604 const char *str = NULL;
1606 if (port->ops->type)
1607 str = port->ops->type(port);
1615 #ifdef CONFIG_PROC_FS
1617 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1619 struct uart_state *state = drv->state + i;
1620 struct tty_port *port = &state->port;
1621 enum uart_pm_state pm_state;
1622 struct uart_port *uport = state->uart_port;
1624 unsigned int status;
1630 mmio = uport->iotype >= UPIO_MEM;
1631 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1632 uport->line, uart_type(uport),
1633 mmio ? "mmio:0x" : "port:",
1634 mmio ? (unsigned long long)uport->mapbase
1635 : (unsigned long long)uport->iobase,
1638 if (uport->type == PORT_UNKNOWN) {
1643 if (capable(CAP_SYS_ADMIN)) {
1644 mutex_lock(&port->mutex);
1645 pm_state = state->pm_state;
1646 if (pm_state != UART_PM_STATE_ON)
1647 uart_change_pm(state, UART_PM_STATE_ON);
1648 spin_lock_irq(&uport->lock);
1649 status = uport->ops->get_mctrl(uport);
1650 spin_unlock_irq(&uport->lock);
1651 if (pm_state != UART_PM_STATE_ON)
1652 uart_change_pm(state, pm_state);
1653 mutex_unlock(&port->mutex);
1655 seq_printf(m, " tx:%d rx:%d",
1656 uport->icount.tx, uport->icount.rx);
1657 if (uport->icount.frame)
1658 seq_printf(m, " fe:%d",
1659 uport->icount.frame);
1660 if (uport->icount.parity)
1661 seq_printf(m, " pe:%d",
1662 uport->icount.parity);
1663 if (uport->icount.brk)
1664 seq_printf(m, " brk:%d",
1666 if (uport->icount.overrun)
1667 seq_printf(m, " oe:%d",
1668 uport->icount.overrun);
1670 #define INFOBIT(bit, str) \
1671 if (uport->mctrl & (bit)) \
1672 strncat(stat_buf, (str), sizeof(stat_buf) - \
1673 strlen(stat_buf) - 2)
1674 #define STATBIT(bit, str) \
1675 if (status & (bit)) \
1676 strncat(stat_buf, (str), sizeof(stat_buf) - \
1677 strlen(stat_buf) - 2)
1681 INFOBIT(TIOCM_RTS, "|RTS");
1682 STATBIT(TIOCM_CTS, "|CTS");
1683 INFOBIT(TIOCM_DTR, "|DTR");
1684 STATBIT(TIOCM_DSR, "|DSR");
1685 STATBIT(TIOCM_CAR, "|CD");
1686 STATBIT(TIOCM_RNG, "|RI");
1690 seq_puts(m, stat_buf);
1697 static int uart_proc_show(struct seq_file *m, void *v)
1699 struct tty_driver *ttydrv = m->private;
1700 struct uart_driver *drv = ttydrv->driver_state;
1703 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1705 for (i = 0; i < drv->nr; i++)
1706 uart_line_info(m, drv, i);
1710 static int uart_proc_open(struct inode *inode, struct file *file)
1712 return single_open(file, uart_proc_show, PDE_DATA(inode));
1715 static const struct file_operations uart_proc_fops = {
1716 .owner = THIS_MODULE,
1717 .open = uart_proc_open,
1719 .llseek = seq_lseek,
1720 .release = single_release,
1724 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1726 * uart_console_write - write a console message to a serial port
1727 * @port: the port to write the message
1728 * @s: array of characters
1729 * @count: number of characters in string to write
1730 * @write: function to write character to port
1732 void uart_console_write(struct uart_port *port, const char *s,
1734 void (*putchar)(struct uart_port *, int))
1738 for (i = 0; i < count; i++, s++) {
1740 putchar(port, '\r');
1744 EXPORT_SYMBOL_GPL(uart_console_write);
1747 * Check whether an invalid uart number has been specified, and
1748 * if so, search for the first available port that does have
1751 struct uart_port * __init
1752 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1754 int idx = co->index;
1756 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1757 ports[idx].membase == NULL))
1758 for (idx = 0; idx < nr; idx++)
1759 if (ports[idx].iobase != 0 ||
1760 ports[idx].membase != NULL)
1769 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1770 * @options: pointer to option string
1771 * @baud: pointer to an 'int' variable for the baud rate.
1772 * @parity: pointer to an 'int' variable for the parity.
1773 * @bits: pointer to an 'int' variable for the number of data bits.
1774 * @flow: pointer to an 'int' variable for the flow control character.
1776 * uart_parse_options decodes a string containing the serial console
1777 * options. The format of the string is <baud><parity><bits><flow>,
1781 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1785 *baud = simple_strtoul(s, NULL, 10);
1786 while (*s >= '0' && *s <= '9')
1795 EXPORT_SYMBOL_GPL(uart_parse_options);
1802 static const struct baud_rates baud_rates[] = {
1803 { 921600, B921600 },
1804 { 460800, B460800 },
1805 { 230400, B230400 },
1806 { 115200, B115200 },
1818 * uart_set_options - setup the serial console parameters
1819 * @port: pointer to the serial ports uart_port structure
1820 * @co: console pointer
1822 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1823 * @bits: number of data bits
1824 * @flow: flow control character - 'r' (rts)
1827 uart_set_options(struct uart_port *port, struct console *co,
1828 int baud, int parity, int bits, int flow)
1830 struct ktermios termios;
1831 static struct ktermios dummy;
1835 * Ensure that the serial console lock is initialised
1837 * If this port is a console, then the spinlock is already
1840 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1841 spin_lock_init(&port->lock);
1842 lockdep_set_class(&port->lock, &port_lock_key);
1845 memset(&termios, 0, sizeof(struct ktermios));
1847 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1850 * Construct a cflag setting.
1852 for (i = 0; baud_rates[i].rate; i++)
1853 if (baud_rates[i].rate <= baud)
1856 termios.c_cflag |= baud_rates[i].cflag;
1859 termios.c_cflag |= CS7;
1861 termios.c_cflag |= CS8;
1865 termios.c_cflag |= PARODD;
1868 termios.c_cflag |= PARENB;
1873 termios.c_cflag |= CRTSCTS;
1876 * some uarts on other side don't support no flow control.
1877 * So we set * DTR in host uart to make them happy
1879 port->mctrl |= TIOCM_DTR;
1881 port->ops->set_termios(port, &termios, &dummy);
1883 * Allow the setting of the UART parameters with a NULL console
1887 co->cflag = termios.c_cflag;
1891 EXPORT_SYMBOL_GPL(uart_set_options);
1892 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1895 * uart_change_pm - set power state of the port
1897 * @state: port descriptor
1898 * @pm_state: new state
1900 * Locking: port->mutex has to be held
1902 static void uart_change_pm(struct uart_state *state,
1903 enum uart_pm_state pm_state)
1905 struct uart_port *port = state->uart_port;
1907 if (state->pm_state != pm_state) {
1909 port->ops->pm(port, pm_state, state->pm_state);
1910 state->pm_state = pm_state;
1915 struct uart_port *port;
1916 struct uart_driver *driver;
1919 static int serial_match_port(struct device *dev, void *data)
1921 struct uart_match *match = data;
1922 struct tty_driver *tty_drv = match->driver->tty_driver;
1923 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1926 return dev->devt == devt; /* Actually, only one tty per port */
1929 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1931 struct uart_state *state = drv->state + uport->line;
1932 struct tty_port *port = &state->port;
1933 struct device *tty_dev;
1934 struct uart_match match = {uport, drv};
1936 mutex_lock(&port->mutex);
1938 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1939 if (device_may_wakeup(tty_dev)) {
1940 if (!enable_irq_wake(uport->irq))
1941 uport->irq_wake = 1;
1942 put_device(tty_dev);
1943 mutex_unlock(&port->mutex);
1946 put_device(tty_dev);
1948 if (console_suspend_enabled || !uart_console(uport))
1949 uport->suspended = 1;
1951 if (port->flags & ASYNC_INITIALIZED) {
1952 const struct uart_ops *ops = uport->ops;
1955 if (console_suspend_enabled || !uart_console(uport)) {
1956 set_bit(ASYNCB_SUSPENDED, &port->flags);
1957 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1959 spin_lock_irq(&uport->lock);
1960 ops->stop_tx(uport);
1961 ops->set_mctrl(uport, 0);
1962 ops->stop_rx(uport);
1963 spin_unlock_irq(&uport->lock);
1967 * Wait for the transmitter to empty.
1969 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1972 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1974 uport->dev ? dev_name(uport->dev) : "",
1975 uport->dev ? ": " : "",
1977 drv->tty_driver->name_base + uport->line);
1979 if (console_suspend_enabled || !uart_console(uport))
1980 ops->shutdown(uport);
1984 * Disable the console device before suspending.
1986 if (console_suspend_enabled && uart_console(uport))
1987 console_stop(uport->cons);
1989 if (console_suspend_enabled || !uart_console(uport))
1990 uart_change_pm(state, UART_PM_STATE_OFF);
1992 mutex_unlock(&port->mutex);
1997 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1999 struct uart_state *state = drv->state + uport->line;
2000 struct tty_port *port = &state->port;
2001 struct device *tty_dev;
2002 struct uart_match match = {uport, drv};
2003 struct ktermios termios;
2005 mutex_lock(&port->mutex);
2007 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2008 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2009 if (uport->irq_wake) {
2010 disable_irq_wake(uport->irq);
2011 uport->irq_wake = 0;
2013 put_device(tty_dev);
2014 mutex_unlock(&port->mutex);
2017 put_device(tty_dev);
2018 uport->suspended = 0;
2021 * Re-enable the console device after suspending.
2023 if (uart_console(uport)) {
2025 * First try to use the console cflag setting.
2027 memset(&termios, 0, sizeof(struct ktermios));
2028 termios.c_cflag = uport->cons->cflag;
2031 * If that's unset, use the tty termios setting.
2033 if (port->tty && termios.c_cflag == 0)
2034 termios = port->tty->termios;
2036 if (console_suspend_enabled)
2037 uart_change_pm(state, UART_PM_STATE_ON);
2038 uport->ops->set_termios(uport, &termios, NULL);
2039 if (console_suspend_enabled)
2040 console_start(uport->cons);
2043 if (port->flags & ASYNC_SUSPENDED) {
2044 const struct uart_ops *ops = uport->ops;
2047 uart_change_pm(state, UART_PM_STATE_ON);
2048 spin_lock_irq(&uport->lock);
2049 ops->set_mctrl(uport, 0);
2050 spin_unlock_irq(&uport->lock);
2051 if (console_suspend_enabled || !uart_console(uport)) {
2052 /* Protected by port mutex for now */
2053 struct tty_struct *tty = port->tty;
2054 ret = ops->startup(uport);
2057 uart_change_speed(tty, state, NULL);
2058 spin_lock_irq(&uport->lock);
2059 ops->set_mctrl(uport, uport->mctrl);
2060 ops->start_tx(uport);
2061 spin_unlock_irq(&uport->lock);
2062 set_bit(ASYNCB_INITIALIZED, &port->flags);
2065 * Failed to resume - maybe hardware went away?
2066 * Clear the "initialized" flag so we won't try
2067 * to call the low level drivers shutdown method.
2069 uart_shutdown(tty, state);
2073 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2076 mutex_unlock(&port->mutex);
2082 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2086 switch (port->iotype) {
2088 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2091 snprintf(address, sizeof(address),
2092 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2098 snprintf(address, sizeof(address),
2099 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2102 strlcpy(address, "*unknown*", sizeof(address));
2106 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2107 port->dev ? dev_name(port->dev) : "",
2108 port->dev ? ": " : "",
2110 drv->tty_driver->name_base + port->line,
2111 address, port->irq, port->uartclk / 16, uart_type(port));
2115 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2116 struct uart_port *port)
2121 * If there isn't a port here, don't do anything further.
2123 if (!port->iobase && !port->mapbase && !port->membase)
2127 * Now do the auto configuration stuff. Note that config_port
2128 * is expected to claim the resources and map the port for us.
2131 if (port->flags & UPF_AUTO_IRQ)
2132 flags |= UART_CONFIG_IRQ;
2133 if (port->flags & UPF_BOOT_AUTOCONF) {
2134 if (!(port->flags & UPF_FIXED_TYPE)) {
2135 port->type = PORT_UNKNOWN;
2136 flags |= UART_CONFIG_TYPE;
2138 port->ops->config_port(port, flags);
2141 if (port->type != PORT_UNKNOWN) {
2142 unsigned long flags;
2144 uart_report_port(drv, port);
2146 /* Power up port for set_mctrl() */
2147 uart_change_pm(state, UART_PM_STATE_ON);
2150 * Ensure that the modem control lines are de-activated.
2151 * keep the DTR setting that is set in uart_set_options()
2152 * We probably don't need a spinlock around this, but
2154 spin_lock_irqsave(&port->lock, flags);
2155 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2156 spin_unlock_irqrestore(&port->lock, flags);
2159 * If this driver supports console, and it hasn't been
2160 * successfully registered yet, try to re-register it.
2161 * It may be that the port was not available.
2163 if (port->cons && !(port->cons->flags & CON_ENABLED))
2164 register_console(port->cons);
2167 * Power down all ports by default, except the
2168 * console if we have one.
2170 if (!uart_console(port))
2171 uart_change_pm(state, UART_PM_STATE_OFF);
2175 #ifdef CONFIG_CONSOLE_POLL
2177 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2179 struct uart_driver *drv = driver->driver_state;
2180 struct uart_state *state = drv->state + line;
2181 struct uart_port *port;
2188 if (!state || !state->uart_port)
2191 port = state->uart_port;
2192 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2195 if (port->ops->poll_init) {
2196 struct tty_port *tport = &state->port;
2199 mutex_lock(&tport->mutex);
2201 * We don't set ASYNCB_INITIALIZED as we only initialized the
2202 * hw, e.g. state->xmit is still uninitialized.
2204 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2205 ret = port->ops->poll_init(port);
2206 mutex_unlock(&tport->mutex);
2212 uart_parse_options(options, &baud, &parity, &bits, &flow);
2213 return uart_set_options(port, NULL, baud, parity, bits, flow);
2219 static int uart_poll_get_char(struct tty_driver *driver, int line)
2221 struct uart_driver *drv = driver->driver_state;
2222 struct uart_state *state = drv->state + line;
2223 struct uart_port *port;
2225 if (!state || !state->uart_port)
2228 port = state->uart_port;
2229 return port->ops->poll_get_char(port);
2232 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2234 struct uart_driver *drv = driver->driver_state;
2235 struct uart_state *state = drv->state + line;
2236 struct uart_port *port;
2238 if (!state || !state->uart_port)
2241 port = state->uart_port;
2242 port->ops->poll_put_char(port, ch);
2246 static const struct tty_operations uart_ops = {
2248 .close = uart_close,
2249 .write = uart_write,
2250 .put_char = uart_put_char,
2251 .flush_chars = uart_flush_chars,
2252 .write_room = uart_write_room,
2253 .chars_in_buffer= uart_chars_in_buffer,
2254 .flush_buffer = uart_flush_buffer,
2255 .ioctl = uart_ioctl,
2256 .throttle = uart_throttle,
2257 .unthrottle = uart_unthrottle,
2258 .send_xchar = uart_send_xchar,
2259 .set_termios = uart_set_termios,
2260 .set_ldisc = uart_set_ldisc,
2262 .start = uart_start,
2263 .hangup = uart_hangup,
2264 .break_ctl = uart_break_ctl,
2265 .wait_until_sent= uart_wait_until_sent,
2266 #ifdef CONFIG_PROC_FS
2267 .proc_fops = &uart_proc_fops,
2269 .tiocmget = uart_tiocmget,
2270 .tiocmset = uart_tiocmset,
2271 .get_icount = uart_get_icount,
2272 #ifdef CONFIG_CONSOLE_POLL
2273 .poll_init = uart_poll_init,
2274 .poll_get_char = uart_poll_get_char,
2275 .poll_put_char = uart_poll_put_char,
2279 static const struct tty_port_operations uart_port_ops = {
2280 .activate = uart_port_activate,
2281 .shutdown = uart_port_shutdown,
2282 .carrier_raised = uart_carrier_raised,
2283 .dtr_rts = uart_dtr_rts,
2287 * uart_register_driver - register a driver with the uart core layer
2288 * @drv: low level driver structure
2290 * Register a uart driver with the core driver. We in turn register
2291 * with the tty layer, and initialise the core driver per-port state.
2293 * We have a proc file in /proc/tty/driver which is named after the
2296 * drv->port should be NULL, and the per-port structures should be
2297 * registered using uart_add_one_port after this call has succeeded.
2299 int uart_register_driver(struct uart_driver *drv)
2301 struct tty_driver *normal;
2307 * Maybe we should be using a slab cache for this, especially if
2308 * we have a large number of ports to handle.
2310 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2314 normal = alloc_tty_driver(drv->nr);
2318 drv->tty_driver = normal;
2320 normal->driver_name = drv->driver_name;
2321 normal->name = drv->dev_name;
2322 normal->major = drv->major;
2323 normal->minor_start = drv->minor;
2324 normal->type = TTY_DRIVER_TYPE_SERIAL;
2325 normal->subtype = SERIAL_TYPE_NORMAL;
2326 normal->init_termios = tty_std_termios;
2327 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2328 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2329 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2330 normal->driver_state = drv;
2331 tty_set_operations(normal, &uart_ops);
2334 * Initialise the UART state(s).
2336 for (i = 0; i < drv->nr; i++) {
2337 struct uart_state *state = drv->state + i;
2338 struct tty_port *port = &state->port;
2340 tty_port_init(port);
2341 port->ops = &uart_port_ops;
2342 port->close_delay = HZ / 2; /* .5 seconds */
2343 port->closing_wait = 30 * HZ;/* 30 seconds */
2346 retval = tty_register_driver(normal);
2350 for (i = 0; i < drv->nr; i++)
2351 tty_port_destroy(&drv->state[i].port);
2352 put_tty_driver(normal);
2360 * uart_unregister_driver - remove a driver from the uart core layer
2361 * @drv: low level driver structure
2363 * Remove all references to a driver from the core driver. The low
2364 * level driver must have removed all its ports via the
2365 * uart_remove_one_port() if it registered them with uart_add_one_port().
2366 * (ie, drv->port == NULL)
2368 void uart_unregister_driver(struct uart_driver *drv)
2370 struct tty_driver *p = drv->tty_driver;
2373 tty_unregister_driver(p);
2375 for (i = 0; i < drv->nr; i++)
2376 tty_port_destroy(&drv->state[i].port);
2379 drv->tty_driver = NULL;
2382 struct tty_driver *uart_console_device(struct console *co, int *index)
2384 struct uart_driver *p = co->data;
2386 return p->tty_driver;
2389 static ssize_t uart_get_attr_uartclk(struct device *dev,
2390 struct device_attribute *attr, char *buf)
2392 struct serial_struct tmp;
2393 struct tty_port *port = dev_get_drvdata(dev);
2395 uart_get_info(port, &tmp);
2396 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2399 static ssize_t uart_get_attr_type(struct device *dev,
2400 struct device_attribute *attr, char *buf)
2402 struct serial_struct tmp;
2403 struct tty_port *port = dev_get_drvdata(dev);
2405 uart_get_info(port, &tmp);
2406 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2408 static ssize_t uart_get_attr_line(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.line);
2418 static ssize_t uart_get_attr_port(struct device *dev,
2419 struct device_attribute *attr, char *buf)
2421 struct serial_struct tmp;
2422 struct tty_port *port = dev_get_drvdata(dev);
2423 unsigned long ioaddr;
2425 uart_get_info(port, &tmp);
2427 if (HIGH_BITS_OFFSET)
2428 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2429 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2432 static ssize_t uart_get_attr_irq(struct device *dev,
2433 struct device_attribute *attr, char *buf)
2435 struct serial_struct tmp;
2436 struct tty_port *port = dev_get_drvdata(dev);
2438 uart_get_info(port, &tmp);
2439 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2442 static ssize_t uart_get_attr_flags(struct device *dev,
2443 struct device_attribute *attr, char *buf)
2445 struct serial_struct tmp;
2446 struct tty_port *port = dev_get_drvdata(dev);
2448 uart_get_info(port, &tmp);
2449 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2452 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2453 struct device_attribute *attr, char *buf)
2455 struct serial_struct tmp;
2456 struct tty_port *port = dev_get_drvdata(dev);
2458 uart_get_info(port, &tmp);
2459 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2463 static ssize_t uart_get_attr_close_delay(struct device *dev,
2464 struct device_attribute *attr, char *buf)
2466 struct serial_struct tmp;
2467 struct tty_port *port = dev_get_drvdata(dev);
2469 uart_get_info(port, &tmp);
2470 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2474 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2475 struct device_attribute *attr, char *buf)
2477 struct serial_struct tmp;
2478 struct tty_port *port = dev_get_drvdata(dev);
2480 uart_get_info(port, &tmp);
2481 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2484 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2485 struct device_attribute *attr, char *buf)
2487 struct serial_struct tmp;
2488 struct tty_port *port = dev_get_drvdata(dev);
2490 uart_get_info(port, &tmp);
2491 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2494 static ssize_t uart_get_attr_io_type(struct device *dev,
2495 struct device_attribute *attr, char *buf)
2497 struct serial_struct tmp;
2498 struct tty_port *port = dev_get_drvdata(dev);
2500 uart_get_info(port, &tmp);
2501 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2504 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2505 struct device_attribute *attr, char *buf)
2507 struct serial_struct tmp;
2508 struct tty_port *port = dev_get_drvdata(dev);
2510 uart_get_info(port, &tmp);
2511 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2514 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2515 struct device_attribute *attr, char *buf)
2517 struct serial_struct tmp;
2518 struct tty_port *port = dev_get_drvdata(dev);
2520 uart_get_info(port, &tmp);
2521 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2524 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2525 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2526 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2527 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2528 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2529 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2530 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2531 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2532 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2533 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2534 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2535 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2536 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2538 static struct attribute *tty_dev_attrs[] = {
2539 &dev_attr_type.attr,
2540 &dev_attr_line.attr,
2541 &dev_attr_port.attr,
2543 &dev_attr_flags.attr,
2544 &dev_attr_xmit_fifo_size.attr,
2545 &dev_attr_uartclk.attr,
2546 &dev_attr_close_delay.attr,
2547 &dev_attr_closing_wait.attr,
2548 &dev_attr_custom_divisor.attr,
2549 &dev_attr_io_type.attr,
2550 &dev_attr_iomem_base.attr,
2551 &dev_attr_iomem_reg_shift.attr,
2555 static const struct attribute_group tty_dev_attr_group = {
2556 .attrs = tty_dev_attrs,
2559 static const struct attribute_group *tty_dev_attr_groups[] = {
2560 &tty_dev_attr_group,
2566 * uart_add_one_port - attach a driver-defined port structure
2567 * @drv: pointer to the uart low level driver structure for this port
2568 * @uport: uart port structure to use for this port.
2570 * This allows the driver to register its own uart_port structure
2571 * with the core driver. The main purpose is to allow the low
2572 * level uart drivers to expand uart_port, rather than having yet
2573 * more levels of structures.
2575 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2577 struct uart_state *state;
2578 struct tty_port *port;
2580 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);
2612 uart_configure_port(drv, state, uport);
2615 * Register the port whether it's detected or not. This allows
2616 * setserial to be used to alter this port's parameters.
2618 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2619 uport->line, uport->dev, port, tty_dev_attr_groups);
2620 if (likely(!IS_ERR(tty_dev))) {
2621 device_set_wakeup_capable(tty_dev, 1);
2623 printk(KERN_ERR "Cannot register tty device on line %d\n",
2628 * Ensure UPF_DEAD is not set.
2630 uport->flags &= ~UPF_DEAD;
2633 mutex_unlock(&port->mutex);
2634 mutex_unlock(&port_mutex);
2640 * uart_remove_one_port - detach a driver defined port structure
2641 * @drv: pointer to the uart low level driver structure for this port
2642 * @uport: uart port structure for this port
2644 * This unhooks (and hangs up) the specified port structure from the
2645 * core driver. No further calls will be made to the low-level code
2648 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2650 struct uart_state *state = drv->state + uport->line;
2651 struct tty_port *port = &state->port;
2652 struct tty_struct *tty;
2655 BUG_ON(in_interrupt());
2657 if (state->uart_port != uport)
2658 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2659 state->uart_port, uport);
2661 mutex_lock(&port_mutex);
2664 * Mark the port "dead" - this prevents any opens from
2665 * succeeding while we shut down the port.
2667 mutex_lock(&port->mutex);
2668 if (!state->uart_port) {
2669 mutex_unlock(&port->mutex);
2673 uport->flags |= UPF_DEAD;
2674 mutex_unlock(&port->mutex);
2677 * Remove the devices from the tty layer
2679 tty_unregister_device(drv->tty_driver, uport->line);
2681 tty = tty_port_tty_get(port);
2683 tty_vhangup(port->tty);
2688 * If the port is used as a console, unregister it
2690 if (uart_console(uport))
2691 unregister_console(uport->cons);
2694 * Free the port IO and memory resources, if any.
2696 if (uport->type != PORT_UNKNOWN)
2697 uport->ops->release_port(uport);
2700 * Indicate that there isn't a port here anymore.
2702 uport->type = PORT_UNKNOWN;
2704 state->uart_port = NULL;
2706 mutex_unlock(&port_mutex);
2712 * Are the two ports equivalent?
2714 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2716 if (port1->iotype != port2->iotype)
2719 switch (port1->iotype) {
2721 return (port1->iobase == port2->iobase);
2723 return (port1->iobase == port2->iobase) &&
2724 (port1->hub6 == port2->hub6);
2729 return (port1->mapbase == port2->mapbase);
2733 EXPORT_SYMBOL(uart_match_port);
2736 * uart_handle_dcd_change - handle a change of carrier detect state
2737 * @uport: uart_port structure for the open port
2738 * @status: new carrier detect status, nonzero if active
2740 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2742 struct tty_port *port = &uport->state->port;
2743 struct tty_struct *tty = port->tty;
2744 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2747 if (ld->ops->dcd_change)
2748 ld->ops->dcd_change(tty, status);
2749 tty_ldisc_deref(ld);
2752 uport->icount.dcd++;
2754 if (port->flags & ASYNC_CHECK_CD) {
2756 wake_up_interruptible(&port->open_wait);
2761 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2764 * uart_handle_cts_change - handle a change of clear-to-send state
2765 * @uport: uart_port structure for the open port
2766 * @status: new clear to send status, nonzero if active
2768 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2770 struct tty_port *port = &uport->state->port;
2771 struct tty_struct *tty = port->tty;
2773 uport->icount.cts++;
2775 if (tty_port_cts_enabled(port)) {
2776 if (tty->hw_stopped) {
2778 tty->hw_stopped = 0;
2779 uport->ops->start_tx(uport);
2780 uart_write_wakeup(uport);
2784 tty->hw_stopped = 1;
2785 uport->ops->stop_tx(uport);
2790 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2793 * uart_insert_char - push a char to the uart layer
2795 * User is responsible to call tty_flip_buffer_push when they are done with
2798 * @port: corresponding port
2799 * @status: state of the serial port RX buffer (LSR for 8250)
2800 * @overrun: mask of overrun bits in @status
2801 * @ch: character to push
2802 * @flag: flag for the character (see TTY_NORMAL and friends)
2804 void uart_insert_char(struct uart_port *port, unsigned int status,
2805 unsigned int overrun, unsigned int ch, unsigned int flag)
2807 struct tty_port *tport = &port->state->port;
2809 if ((status & port->ignore_status_mask & ~overrun) == 0)
2810 if (tty_insert_flip_char(tport, ch, flag) == 0)
2811 ++port->icount.buf_overrun;
2814 * Overrun is special. Since it's reported immediately,
2815 * it doesn't affect the current character.
2817 if (status & ~port->ignore_status_mask & overrun)
2818 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2819 ++port->icount.buf_overrun;
2821 EXPORT_SYMBOL_GPL(uart_insert_char);
2823 EXPORT_SYMBOL(uart_write_wakeup);
2824 EXPORT_SYMBOL(uart_register_driver);
2825 EXPORT_SYMBOL(uart_unregister_driver);
2826 EXPORT_SYMBOL(uart_suspend_port);
2827 EXPORT_SYMBOL(uart_resume_port);
2828 EXPORT_SYMBOL(uart_add_one_port);
2829 EXPORT_SYMBOL(uart_remove_one_port);
2831 MODULE_DESCRIPTION("Serial driver core");
2832 MODULE_LICENSE("GPL");